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29183629 | Using laser microsurgery and cell fusion we have explored how additional centrosomes and/or chromosomes influence the duration of mitosis in human cells. We found that doubling the chromosome number added approximately 10 min to a 20 min division, whereas doubling the number of centrosomes added approximately 30 min more. Extra centrosomes and/or chromosomes prolong mitosis by delaying satisfaction of the spindle assembly checkpoint. Thus mitosis can be prolonged by non-genetic means and extra chromosomes and centrosomes probably contribute to the elevated mitotic index seen in many tumours. | Extra centrosomes and/or chromosomes prolong mitosis in human cells |
29185044 | The finding of an association between genetic variation at the transforming growth-factor alpha (TGFA) locus and nonsyndromic isolated cleft palate (CP) represents a potentially important breakthrough in our understanding of this condition. The present study was undertaken to assess the feasibility of detecting linkage to putative CP-susceptibility loci, such as TGFA. To this end, the familial recurrence pattern for CP was evaluated to determine the most likely mode of inheritance for this condition. The study took advantage of the high ascertainment and uniform registration of CP in Denmark. In addition, the study utilized estimates of familial recurrence that were obtained by register linkage and, hence, were not subject to either recall bias or the potentially biasing influence of nonresponders. The recurrence risks for first-, second-, and third-degree relatives of 1,364 nonsyndromic CP probands were estimated to be 2.74% (72/2,628), 0.28% (3/1,068), and 0.00% (0/360), respectively. These estimates are close to published estimates based on questionnaire and interview data. The population prevalence for nonsyndromic CP was, however, found to be considerable higher than usually reported (0.058% [1,456/2,523,023]). Analyses of these and previously published data, using the method presented by Risch, indicated that major-locus or additive multilocus inheritance of CP is unlikely. The familial recurrence pattern was, however, consistent with CP being determined by several interacting loci. Under such a model, a single locus accounting for more than a sixfold increase in the risk to first-degree relatives of CP probands is unlikely, whereas a single locus accounting for a threefold increase provided a good fit to the data. Such a locus could be detected in a realistic sample of affected sib pairs. | Familial recurrence-pattern analysis of nonsyndromic isolated cleft palate--a Danish Registry study. |
29190724 | Gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. Over 70% of new cases and deaths occur in developing countries. In the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. Epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Recent advancements in the rapidly evolving field of cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer, including DNA methylation, histone modifications, nucleosome positioning, noncoding RNAs, and microRNAs. Aberrant DNA methylation in the promoter regions of gene, which leads to inactivation of tumor suppressor and other cancer-related genes in cancer cells, is the most well-defined epigenetic hallmark in gastric cancer. The advantages of gene methylation as a target for detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as serum and gastric washes have led to many studies of application in gastric cancer. This review focuses on the most common and important phenomenon of epigenetics, DNA methylation, in gastric cancer and illustrates the impact epigenetics has had on this field. | Gene methylation in gastric cancer. |
29214508 | The region located immediately upstream from the Klebsiella aerogenes urease structural genes was sequenced and shown to possess an open reading frame capable of encoding a 29.8-kDa peptide. Deletions were generated in this gene, denoted ureD, and in each of the genes (ureE, ureF, and ureG) located immediately downstream of the three structural genes. Transformation of the mutated plasmids into Escherichia coli resulted in high levels of urease expression, but the enzyme was inactive (deletions in ureD, ureF, or ureG) or only partially active (deletions in ureE). Ureases were purified from the recombinant cells and shown to be identical to control enzyme when analyzed by gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis; however, in every case the activity levels correlated to nickel contents as analyzed by atomic absorption analysis. UreD, UreE, UreF, and UreG peptides were tentatively identified by gel electrophoretic comparison of mutant and control cell extracts, by in vivo expression of separately cloned genes, or by in vitro transcription-translation analyses; the assignments were confirmed for UreE and UreG by amino-terminal sequencing. The latter peptides (apparent M(r)s, 23,900 and 28,500) were present at high levels comparable to those of the urease subunits, whereas the amounts of UreF (apparent M(r), 27,000) and UreD (apparent M(r), 29,300) were greatly reduced, perhaps because of the lack of good ribosome binding sites in the regions upstream of these open reading frames. These results demonstrate that all four accessory genes are necessary for the functional incorporation of the urease metallocenter. | Klebsiella aerogenes urease gene cluster: sequence of ureD and demonstration that four accessory genes (ureD, ureE, ureF, and ureG) are involved in nickel metallocenter biosynthesis. |
29224825 | The onset of cellular polyploidy is recognized in all differentiated mammalian tissues. Polyploidy has been noted frequently in the normal liver, as well as in pathophysiological states of the liver. As insights into the significance of polyploidy accumulate gradually, it is becoming clear that cells belonging to high ploidy classes exhibit advancement toward terminal differentiation and cellular senescence with greater probabilities of apoptosis. Involvement of specific genetic abnormalities, such as impaired DNA repair, may lead to hepatocellular polyploidy. Working models indicate that extensive polyploidy could lead to organ failure, as well as to oncogenesis with activation of precancerous cell clones. | Hepatic polyploidy and liver growth control. |
29231620 | Cortical malformations are commonly associated with intractable epilepsy and other developmental disorders. Our studies utilize the tish rat, a spontaneously occurring genetic model of subcortical band heterotopia (SBH) associated with epilepsy, to evaluate the developmental events underlying SBH formation in the neocortex. Our results demonstrate that Pax6(+) and Tbr2(+) progenitors are mislocalized in tish(+/-) and tish(-/-)- neocortex throughout neurogenesis. In addition, mislocalized tish(-/-) progenitors possess a longer cell cycle than wild type or normally-positioned tish(-/-) progenitors, owing to a lengthened G(2)+M+G(1) time. This mislocalization is not associated with adherens junction breakdown or loss of radial glial polarity in the ventricular zone (VZ), as assessed by immunohistochemistry against phalloidin (to identify F-actin), aPKC-λ and Par3. However, vimentin immunohistochemistry indicates that the radial glial scaffold is disrupted in the region of the tish(-/-) heterotopia. Moreover, lineage tracing experiments using in utero electroporation in tish(-/-) neocortex demonstrate that mislocalized progenitors do not retain contact with the ventricular surface and that ventricular/subventricular zone (SVZ) progenitors produce neurons that migrate into both the heterotopia and cortical plate (CP). Taken together, these findings define a series of developmental errors contributing to SBH formation that differs fundamentally from a primary error in neuronal migration. | Disturbances in the positioning, proliferation and apoptosis of neural progenitors contribute to subcortical band heterotopia formation. |
29253460 | OBJECTIVE To assess whether sex differences exist in the angiographic severity, management and outcomes of acute coronary syndromes (ACS).
METHODS The study comprised 7638 women and 19 117 men with ACS who underwent coronary angiography and were included in GRACE (Global Registry of Acute Coronary Events) from 1999-2006. Normal vessels/mild disease was defined as <50% stenosis in all epicardial vessels; advanced disease was defined as >or=one vessel with >or=50% stenosis.
RESULTS Women were older than men and had higher rates of cardiovascular risk factors. Men and women presented equally with chest pain; however, jaw pain and nausea were more frequent among women. Women were more likely to have normal/mild disease (12% vs 6%, p<0.001) and less likely to have left-main and three-vessel disease (27% vs 32%, p<0.001) or undergo percutaneous coronary intervention (65% vs 68%, p<0.001). Women and men with normal and mild disease were treated less aggressively than those with advanced disease. Women with advanced disease had a higher risk of death (4% vs 3%, p<0.01). After adjustment for age and extent of disease, women were more likely to have adverse outcomes (death, myocardial infarction, stroke and rehospitalisation) at six months compared to men (odds ratio 1.24, 95% confidence interval 1.14 to 1.34); however, sex differences in mortality were no longer statistically significant.
CONCLUSIONS Women with ACS were more likely to have cardiovascular disease risk factors and atypical symptoms such as nausea compared with men, but were more likely to have normal/mild angiographic coronary artery disease. Further study regarding sex differences related to disease severity is warranted. | Sex-related differences in the presentation, treatment and outcomes among patients with acute coronary syndromes: the Global Registry of Acute Coronary Events. |
29288582 | GITR (glucocorticoid-induced TNFR family related gene) is a member of the TNFR superfamily (TNFRSF) that is expressed in different cell types, including T lymphocytes. Because of a high homology in its cytoplasmic region with other known costimulatory members of the TNFRSF, we investigated whether GITR played a costimulatory role in T lymphocyte subpopulations. Our results show that the proliferation response of CD8+ and CD4+ peripheral T cell subpopulations was potentiated when a GITR costimulus was added to an anti-CD3 stimulus. Furthermore, expression of the main activation-induced receptor (IL-2Ralpha) and production of IL-2 and IFN-gamma were increased more with a GITR costimulus than with anti-CD3 alone. GITR stimulation also enhanced anti-CD3-induced ERK phosphorylation, suggesting that GITR is involved in MAPK-pathway activation. Interestingly, CD4+CD25+ regulatory T cell (Treg cell) proliferation was triggered by the GITR costimulus; Treg cell proliferation was paralleled by the loss of the anergic phenotype and suppressor activity. Nevertheless, unstimulated GITR(-/-) CD4+CD25+ and GITR(+/+) CD4+CD25+ cells were equally able to exert suppressor activity on CD4+CD25- responder cells. These results indicate a novel function for GITR as costimulatory molecule of T cell subsets. | GITR, a member of the TNF receptor superfamily, is costimulatory to mouse T lymphocyte subpopulations. |
29321530 | The central role of phosphoinositide 3-kinase (PI3K) activation in tumour cell biology has prompted a sizeable effort to target PI3K and/or downstream kinases such as AKT and mammalian target of rapamycin (mTOR) in cancer. However, emerging clinical data show limited single-agent activity of inhibitors targeting PI3K, AKT or mTOR at tolerated doses. One exception is the response to PI3Kδ inhibitors in chronic lymphocytic leukaemia, where a combination of cell-intrinsic and -extrinsic activities drive efficacy. Here, we review key challenges and opportunities for the clinical development of inhibitors targeting the PI3K–AKT–mTOR pathway. Through a greater focus on patient selection, increased understanding of immune modulation and strategic application of rational combinations, it should be possible to realize the potential of this promising class of targeted anticancer agents. | PI3K and cancer: lessons, challenges and opportunities |
29334259 | Cataloging the very large number of undescribed species of insects could be greatly accelerated by automated DNA based approaches, but procedures for large-scale species discovery from sequence data are currently lacking. Here, we use mitochondrial DNA variation to delimit species in a poorly known beetle radiation in the genus Rivacindela from arid Australia. Among 468 individuals sampled from 65 sites and multiple morphologically distinguishable types, sequence variation in three mtDNA genes (cytochrome oxidase subunit 1, cytochrome b, 16S ribosomal RNA) was strongly partitioned between 46 or 47 putative species identified with quantitative methods of species recognition based on fixed unique ("diagnostic") characters. The boundaries between groups were also recognizable from a striking increase in branching rate in clock-constrained calibrated trees. Models of stochastic lineage growth (Yule models) were combined with coalescence theory to develop a new likelihood method that determines the point of transition from species-level (speciation and extinction) to population-level (coalescence) evolutionary processes. Fitting the location of the switches from speciation to coalescent nodes on the ultrametric tree of Rivacindela produced a transition in branching rate occurring at 0.43 Mya, leading to an estimate of 48 putative species (confidence interval for the threshold ranging from 47 to 51 clusters within 2 logL units). Entities delimited in this way exhibited biological properties of traditionally defined species, showing coherence of geographic ranges, broad congruence with morphologically recognized species, and levels of sequence divergence typical for closely related species of insects. The finding of discontinuous evolutionary groupings that are readily apparent in patterns of sequence variation permits largely automated species delineation from DNA surveys of local communities as a scaffold for taxonomy in this poorly known insect group. | Sequence-based species delimitation for the DNA taxonomy of undescribed insects. |
29347970 | Th17 and regulatory T (Treg) cells play opposite roles in autoimmune diseases. However, the mechanisms underlying their proper migration to inflammatory tissues are unclear. In this study, we report that these two T cell subsets both express CCR6. CCR6 expression in Th17 cells is regulated by TGF-beta and requires two nuclear receptors, RORalpha and RORgamma. Th17 cells also express the CCR6 ligand CCL20, which is induced synergistically by TGF-beta and IL-6, which requires STAT3, RORgamma and IL-21. Th17 cells, by producing CCL20, promote migration of Th17 and Treg cells in vitro in a CCR6-dependent manner. Lack of CCR6 in Th17 cells reduces the severity of experimental autoimmune encephalomyelitis and Th17 and Treg recruitment into inflammatory tissues. Similarly, CCR6 on Treg cells is also important for their recruitment into inflammatory tissues. Our data indicate an important role of CCR6 in Treg and Th17 cell migration. | CCR6 regulates the migration of inflammatory and regulatory T cells. |
29362104 | The effect of omega-3, omega-6 and omega-9 unsaturated fatty acids (UFAs) on receptor-mediated Ca2+ entry was investigated in a T-cell line (JURKAT) by using anti-CD3 antibodies (OKT3) to induce intracellular Ca2+ [( Ca2+]i) increase and Ca2+ influx. All the UFAs, as well as Ni2+ ions and 12-O-tetradecanoylphorbol 13-acetate, decreased the OKT3-induced sustained [Ca2+]i increase to basal levels. Although non-esterified fatty acids activate protein kinase C (PKC) [McPhail, Clayton & Snyderman (1984) Science 224, 622-624; Murakami, Chan & Routtenberg (1986) J. Biol. Chem. 261, 15424-15429], studies using H-7 and analysis of the PKC-dependent phosphorylation of 19 and 80 kDa marker substrates ruled out the involvement of PKC in UFA-induced inhibition of Ca2+ entry. Flow-cytometry analysis showed that UFAs do not interfere with antibody-receptor binding. BSA (0.2%, w/v) reversed the effect of UFAs after these fatty acids have decreased the OKT3-induced [Ca2+]i increase to basal levels. The relevance of these findings and possible mechanisms for inhibition by UFAs of receptor-mediated Ca2+ influx were discussed. | Inhibition of receptor-mediated calcium influx in T cells by unsaturated non-esterified fatty acids. |
29366489 | Deleted in liver cancer 1 (DLC-1), as its name implied, was originally isolated as a potential tumor suppressor gene often deleted in hepatocellular carcinoma. Further studies have indicated that down-expression of DLC-1 either by genomic deletion or DNA methylation is associated with a variety of cancer types including lung, breast, prostate, kidney, colon, uterus, ovary, and stomach. Re-expression of DLC-1 in cancer cells regulates the structure of actin cytoskeleton and focal adhesions and significantly inhibits cell growth, supporting its role as a tumor suppressor. This tumor suppressive function relies on DLC-1's RhoGTPase activating protein (RhoGAP) activity and steroidogenic acute regulatory (StAR)-related lipid transfer (START) domain, as well as its focal adhesion localization, which is recruited by the Src Homology 2 (SH2) domains of tensins in a phosphotyrosine-independent fashion. Therefore, the expression and subcellular localization of DLC-1 could be a useful molecular marker for cancer prognosis, whereas DLC-1 and its downstream signaling molecules might be therapeutic targets for the treatment of cancer. | Deleted in liver cancer-1 (DLC-1): a tumor suppressor not just for liver. |
29367554 | BACKGROUND & AIMS Although the p53 tumor suppressor has been extensively studied, many critical questions remain unanswered about the biological functions of p53 homologs, p73 and p63. Accumulating evidence suggests that both p73 and p63 play important roles in regulation of apoptosis, cell differentiation, and therapeutic drug sensitivity.
METHODS Gastric epithelial cells were cocultured with Helicobacter pylori, and the roles of p63 and p73 proteins were assessed by luciferase reporter, real-time polymerase chain reaction, immunoblotting, and cell survival assays. Short hairpin RNA and dominant-negative mutants were used to inhibit activity of p73 and p63 isoforms. Human and murine gastric tissues were analyzed by immunohistochemistry with p73 and p63 antibodies and modified Steiner's silver method.
RESULTS Interaction of H pylori with gastric epithelial cells leads to robust up-regulation of p73 protein in vitro and in vivo in human gastritis specimens and H pylori-infected mice. The p73 increase resulted in up-regulation of pro-apoptotic genes, NOXA, PUMA, and FAS receptor in gastric epithelial cells. Down-regulation of p73 activity suppressed cell death and Fas receptor induced by H pylori. Bacterial virulence factors within the cag pathogenicity island, c-Abl tyrosine kinase, and interaction with p63 isoforms control the activity of p73.
CONCLUSION Our findings implicate p73 in H pylori-induced apoptosis and more generally suggest that the p53 family may play a role in the epithelial cell response to H pylori infection. | Interaction of Helicobacter pylori with gastric epithelial cells is mediated by the p53 protein family. |
29381091 | Brown adipocytes dissipate energy, whereas white adipocytes are an energy storage site. We explored the plasticity of different white adipose tissue depots in acquiring a brown phenotype by cold exposure. By comparing cold-induced genes in white fat to those enriched in brown compared with white fat, at thermoneutrality we defined a "brite" transcription signature. We identified the genes, pathways, and promoter regulatory motifs associated with "browning," as these represent novel targets for understanding this process. For example, neuregulin 4 was more highly expressed in brown adipose tissue and upregulated in white fat upon cold exposure, and cell studies showed that it is a neurite outgrowth-promoting adipokine, indicative of a role in increasing adipose tissue innervation in response to cold. A cell culture system that allows us to reproduce the differential properties of the discrete adipose depots was developed to study depot-specific differences at an in vitro level. The key transcriptional events underpinning white adipose tissue to brown transition are important, as they represent an attractive proposition to overcome the detrimental effects associated with metabolic disorders, including obesity and type 2 diabetes. | Brown and white adipose tissues: intrinsic differences in gene expression and response to cold exposure in mice |
29387024 | BACKGROUND Pregnant women with type 1 diabetes are a high-risk population who are recommended to strive for optimal glucose control, but neonatal outcomes attributed to maternal hyperglycaemia remain suboptimal. Our aim was to examine the effectiveness of continuous glucose monitoring (CGM) on maternal glucose control and obstetric and neonatal health outcomes.
METHODS In this multicentre, open-label, randomised controlled trial, we recruited women aged 18-40 years with type 1 diabetes for a minimum of 12 months who were receiving intensive insulin therapy. Participants were pregnant (≤13 weeks and 6 days' gestation) or planning pregnancy from 31 hospitals in Canada, England, Scotland, Spain, Italy, Ireland, and the USA. We ran two trials in parallel for pregnant participants and for participants planning pregnancy. In both trials, participants were randomly assigned to either CGM in addition to capillary glucose monitoring or capillary glucose monitoring alone. Randomisation was stratified by insulin delivery (pump or injections) and baseline glycated haemoglobin (HbA1c). The primary outcome was change in HbA1c from randomisation to 34 weeks' gestation in pregnant women and to 24 weeks or conception in women planning pregnancy, and was assessed in all randomised participants with baseline assessments. Secondary outcomes included obstetric and neonatal health outcomes, assessed with all available data without imputation. This trial is registered with ClinicalTrials.gov, number NCT01788527.
FINDINGS Between March 25, 2013, and March 22, 2016, we randomly assigned 325 women (215 pregnant, 110 planning pregnancy) to capillary glucose monitoring with CGM (108 pregnant and 53 planning pregnancy) or without (107 pregnant and 57 planning pregnancy). We found a small difference in HbA1c in pregnant women using CGM (mean difference -0·19%; 95% CI -0·34 to -0·03; p=0·0207). Pregnant CGM users spent more time in target (68% vs 61%; p=0·0034) and less time hyperglycaemic (27% vs 32%; p=0·0279) than did pregnant control participants, with comparable severe hypoglycaemia episodes (18 CGM and 21 control) and time spent hypoglycaemic (3% vs 4%; p=0·10). Neonatal health outcomes were significantly improved, with lower incidence of large for gestational age (odds ratio 0·51, 95% CI 0·28 to 0·90; p=0·0210), fewer neonatal intensive care admissions lasting more than 24 h (0·48; 0·26 to 0·86; p=0·0157), fewer incidences of neonatal hypoglycaemia (0·45; 0·22 to 0·89; p=0·0250), and 1-day shorter length of hospital stay (p=0·0091). We found no apparent benefit of CGM in women planning pregnancy. Adverse events occurred in 51 (48%) of CGM participants and 43 (40%) of control participants in the pregnancy trial, and in 12 (27%) of CGM participants and 21 (37%) of control participants in the planning pregnancy trial. Serious adverse events occurred in 13 (6%) participants in the pregnancy trial (eight [7%] CGM, five [5%] control) and in three (3%) participants in the planning pregnancy trial (two [4%] CGM and one [2%] control). The most common adverse events were skin reactions occurring in 49 (48%) of 103 CGM participants and eight (8%) of 104 control participants during pregnancy and in 23 (44%) of 52 CGM participants and five (9%) of 57 control participants in the planning pregnancy trial. The most common serious adverse events were gastrointestinal (nausea and vomiting in four participants during pregnancy and three participants planning pregnancy).
INTERPRETATION Use of CGM during pregnancy in patients with type 1 diabetes is associated with improved neonatal outcomes, which are likely to be attributed to reduced exposure to maternal hyperglycaemia. CGM should be offered to all pregnant women with type 1 diabetes using intensive insulin therapy. This study is the first to indicate potential for improvements in non-glycaemic health outcomes from CGM use.
FUNDING Juvenile Diabetes Research Foundation, Canadian Clinical Trials Network, and National Institute for Health Research. | Continuous glucose monitoring in pregnant women with type 1 diabetes (CONCEPTT): a multicentre international randomised controlled trial |
29399239 | Neutrophil extracellular traps (NETs) are made of processed chromatin bound to granular and selected cytoplasmic proteins. NETs are released by white blood cells called neutrophils, maybe as a last resort, to control microbial infections. This release of chromatin is the result of a unique form of cell death, dubbed "NETosis. " Here we review our understanding of how NETs are made, their function in infections and as danger signals, and their emerging importance in autoimmunity and coagulation. | Neutrophil extracellular traps: Is immunity the second function of chromatin? |
29422484 | Cdk5 is a member of the cyclin-dependent kinase (Cdk) family, which is activated by neuronal activators p35 or p39. Cdk5 regulates a variety of neuronal activities including migration, synaptic activity and neuronal death. p35 and p39 impart cytoplasmic membrane association of p35-Cdk5 and p39-Cdk5, respectively, through their myristoylation, but it is not clearly understood how the cellular localization is related to different functions. We investigated the role of Cdk5 activity in the subcellular localization of p35-Cdk5 and p39-Cdk5. Cdk5 activity affected the localization of p35-Cdk5 and p39-Cdk5 through phosphorylation of p35 or p39. Using unphosphorylated or phosphomimetic mutants of p35 and p39, we found that phosphorylation at Ser8, common to p35 and p39, by Cdk5 regulated the cytoplasmic localization and perinuclear accumulation of unphosphorylated S8A mutants, and whole cytoplasmic distribution of phosphomimetic S8E mutants. Cdk5 activity was necessary to retain Cdk5-activator complexes in the cytoplasm. Nevertheless, small but distinct amounts of p35 and p39 were detected in the nucleus. In particular, nuclear p35 and p39 were increased when the Cdk5 activity was inhibited. p39 had a greater propensity to accumulate in the nucleus than p35, and phosphorylation at Thr84, specific to p39, regulated the potential nuclear localization activity of the Lys cluster in p39. These results suggest that the subcellular localization of the Cdk5-activator complexes is determined by its kinase activity, and also implicate a role for p39-Cdk5 in the nucleus. | Phosphorylation of p35 and p39 by Cdk5 determines the subcellular location of the holokinase in a phosphorylation-site-specific manner. |
29423324 | Human group 1 ILCs consist of at least three phenotypically distinct subsets, including NK cells, CD127(+) ILC1, and intraepithelial CD103(+) ILC1. In inflamed intestinal tissues from Crohn's disease patients, numbers of CD127(+) ILC1 increased at the cost of ILC3. Here we found that differentiation of ILC3 to CD127(+) ILC1 is reversible in vitro and in vivo. CD127(+) ILC1 differentiated to ILC3 in the presence of interleukin-2 (IL-2), IL-23, and IL-1β dependent on the transcription factor RORγt, and this process was enhanced in the presence of retinoic acid. Furthermore, we observed in resection specimen from Crohn's disease patients a higher proportion of CD14(+) dendritic cells (DC), which in vitro promoted polarization from ILC3 to CD127(+) ILC1. In contrast, CD14(-) DCs promoted differentiation from CD127(+) ILC1 toward ILC3. These observations suggest that environmental cues determine the composition, function, and phenotype of CD127(+) ILC1 and ILC3 in the gut. | Interleukin-12 and -23 Control Plasticity of CD127(+) Group 1 and Group 3 Innate Lymphoid Cells in the Intestinal Lamina Propria. |
29429111 | Forkhead box transcription factor, class O (FOXO) is a mammalian homologue of DAF-16, which is known to regulate the lifespan of Caenorhabditis elegans and includes subfamilies of forkhead transcription factors such as AFX, FKHRL1, and FKHR. FKHR is phosphorylated on three sites (Thr-24, Ser-256, and Ser-319) in a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent manner, thereby inhibiting death signals. We here documented dephosphorylation of FKHR following transient forebrain ischemia with its concomitant translocation into the nucleus in neurons in gerbil and mouse brains. The activation of FKHR preceded delayed neuronal death in the vulnerable hippocampal regions following ischemic brain injury. The FKHR activation was accompanied by an increase in DNA binding activity for FKHR-responsive element on the Fas ligand promoter. We also defined FKHR-induced downstream targets such as Fas ligand and Bim in brain ischemia. Therefore, we propose a new strategy to rescue neurons from delayed neuronal death by promoting the survival signaling. Sodium orthovanadate, a protein tyrosine phosphatase inhibitor, up-regulated Akt activity in the brain and in turn rescue neurons from delayed neuronal death by inhibiting FKHR-dependent or -independent death signals in neurons. | Transcriptional regulation of neuronal genes and its effect on neural functions: expression and function of forkhead transcription factors in neurons. |
29459383 | The major histocompatibility complex class I molecules display peptides (pMHC I) on the cell surface for immune surveillance by CD8(+) T cells. These peptides are generated by proteolysis of intracellular polypeptides by the proteasome in the cytoplasm and then in the endoplasmic reticulum (ER) by the ER aminopeptidase associated with antigen processing (ERAAP). To define the unknown mechanism of ERAAP function in vivo, we analyzed naturally processed peptides in cells with or without appropriate MHC I and ERAAP. In the absence of MHC I, ERAAP degraded the antigenic precursors in the ER. However, MHC I molecules could bind proteolytic intermediates and were essential for generation of the final peptide by ERAAP. Thus, ERAAP synergizes with MHC I to generate the final pMHC I repertoire. | ERAAP synergizes with MHC class I molecules to make the final cut in the antigenic peptide precursors in the endoplasmic reticulum. |
29460384 | OBJECTIVE To describe the sources of protein intake in a sample of the US adult population and among subgroups defined by race-ethnicity, age, and gender.
DESIGN The Third National Health and Nutrition Examination Survey, 1988-1991, is a stratified random sample of the total civilian noninstitutionalized population, drawn from the 50 United States and the District of Columbia. For all foods consumed by the participants, based on a 24-hour dietary recall, protein sources and the contribution of each protein type to the total protein intake were determined. SUBJECTS Adult participants in the third National Health and Nutrition Examination Survey (n = 7,924). STATISTICAL ANALYSES Weighted total, age-specific, and age-adjusted mean protein intakes were calculated using SAS and WesVarPC. Statistical differences were determined by 2-tailed t tests.
RESULTS The main protein source in the American diet is animal protein (69%). Meat, fish, and poultry protein combined contributed the most to animal protein (42%), followed by dairy protein (20%). Grains (18%) contributed the most to plant protein consumption. Women consumed a lower percentage of beef (14%) and pork (7%) protein than did men (18% and 9%, respectively). Women also consumed a higher percentage of poultry (13%), dairy (22%), and fruit and vegetable (11%) protein than did men (11%, 19%, and 9%, respectively). Blacks reported eating a higher percentage of poultry (18%) and pork (11%) protein and a lower percent of dairy protein (14%) than did whites (12%, 7%, and 22%, respectively) and Mexican-Americans (11%, 8%, and 17%, respectively). Mexican-Americans consumed a higher percentage of legume (7%) and egg (7%) protein than did whites (4% and 4%, respectively) and blacks (4% and 5%, respectively). Whites consumed a higher percentage of grain protein (19%) than did blacks (16%) and Mexican-Americans (15%).
CONCLUSIONS These results show that, although the percentage of total energy from protein may be similar among race-ethnicities and between men and women, their sources of protein are different. These differences should be taken into account when providing nutrition education for specific populations. | Estimates of animal and plant protein intake in US adults: results from the Third National Health and Nutrition Examination Survey, 1988-1991. |
29467201 | Ecdysteroids are steroid hormones, which coordinate major developmental transitions in insects. Both the rises and falls in circulating levels of active hormones are important for coordinating molting and metamorphosis, making both ecdysteroid biosynthesis and inactivation of physiological relevance. We demonstrate that Drosophila melanogaster Cyp18a1 encodes a cytochrome P450 enzyme (CYP) with 26-hydroxylase activity, a prominent step in ecdysteroid catabolism. A clear ortholog of Cyp18a1 exists in most insects and crustaceans. When Cyp18a1 is transfected in Drosophila S2 cells, extensive conversion of 20-hydroxyecdysone (20E) into 20-hydroxyecdysonoic acid is observed. This is a multi-step process, which involves the formation of 20,26-dihydroxyecdysone as an intermediate. In Drosophila larvae, Cyp18a1 is expressed in many target tissues of 20E. We examined the consequences of Cyp18a1 inactivation on Drosophila development. Null alleles generated by excision of a P element and RNAi knockdown of Cyp18a1 both result in pupal lethality, possibly as a consequence of impaired ecdysteroid degradation. Our data suggest that the inactivation of 20E is essential for proper development and that CYP18A1 is a key enzyme in this process. | CYP18A1, a key enzyme of Drosophila steroid hormone inactivation, is essential for metamorphosis. |
29473081 | Glycosylation is a stepwise procedure of covalent attachment of oligosaccharide chains to proteins or lipids, and alterations in this process, especially increased sialylation, have been associated with malignant transformation and metastasis. The role of altered sialylation in multiple myeloma (MM) cell trafficking has not been previously investigated. In the present study we identified high expression of β-galactoside α-2,3-sialyltransferase, ST3GAL6, in MM cell lines and patients. This gene plays a key role in selectin ligand synthesis in humans through the generation of functional sialyl Lewis X. In MRC IX patients, high expression of this gene is associated with inferior overall survival. In this study we demonstrate that knockdown of ST3GAL6 results in a significant reduction in levels of α-2,3-linked sialic acid on the surface of MM cells with an associated significant reduction in adhesion to MM bone marrow stromal cells and fibronectin along with reduced transendothelial migration in vitro. In support of our in vitro findings, we demonstrate significantly reduced homing and engraftment of ST3GAL6 knockdown MM cells to the bone marrow niche in vivo, along with decreased tumor burden and prolonged survival. This study points to the importance of altered glycosylation, particularly sialylation, in MM cell adhesion and migration. | The sialyltransferase ST3GAL6 influences homing and survival in multiple myeloma. |
29495185 | There have been numerous epidemiologic investigations to determine factors that may affect cancer risk. There is also a rich tradition of evaluating potential somatic changes in the cancer itself to predict recurrence and/or mortality after diagnosis. However, there has been relatively little | New developments in the epidemiology of cancer prognosis: traditional and molecular predictors of treatment response and survival. |
29504413 | Gonadal steroid hormones regulate sexually dimorphic development of brain functions and behaviors. Their nuclear receptors offer the opportunity to relate molecular events in neurons to simple instinctive mammalian behaviors. We have determined the role of estrogen receptor (ER) activation by endogenous estrogen in the development of male-typical behaviors by the use of transgenic estrogen-receptor-deficient (ERKO) mice. Surprisingly, in spite of the fact that they are infertile, ERKO mice showed normal motivation to mount females but they achieved less intromissions and virtually no ejaculations. Aggressive behaviors were dramatically reduced and male-typical offensive attacks were rarely displayed by ERKO males. Moreover, ER gene disruption demasculinized open-field behaviors. In the brain, despite the evident loss of functional ER protein, the androgen-dependent system appears to be normally present in ERKO mice. Together, these findings indicate that ER gene expression during development plays a major role in the organization of male-typical aggressive and emotional behaviors in addition to simple sexual behaviors. | Behavioral effects of estrogen receptor gene disruption in male mice. |
29509926 | Membrane cholesterol modulates a variety of cell signaling pathways and functions. While cholesterol depletion by high-density lipoproteins (HDLs) has potent anti-inflammatory effects in various cell types, its effects on inflammatory responses in macrophages remain elusive. Here we show overt pro-inflammatory effects of HDL-mediated passive cholesterol depletion and lipid raft disruption in murine and human primary macrophages in vitro. These pro-inflammatory effects were confirmed in vivo in peritoneal macrophages from apoA-I transgenic mice, which have elevated HDL levels. In line with these findings, the innate immune responses required for clearance of P. aeruginosa bacterial infection in lung were compromised in mice with low HDL levels. Expression analysis, ChIP-PCR, and combinatorial pharmacological and genetic intervention studies unveiled that both native and reconstituted HDL enhance Toll-like-receptor-induced signaling by activating a PKC-NF-κB/STAT1-IRF1 axis, leading to increased inflammatory cytokine expression. HDL's pro-inflammatory activity supports proper functioning of macrophage immune responses. | High-Density Lipoproteins Exert Pro-inflammatory Effects on Macrophages via Passive Cholesterol Depletion and PKC-NF-κB/STAT1-IRF1 Signaling. |
29518440 | In land mammals, a major task of the kidney is to reabsorb water to allow survival in a dry environment. Water conservation is enhanced by the renal medulla, which concentrates the urine to a level up to four times the osmolality of plasma. To produce this unique gradient of osmolality, the medulla has a countercurrent system of vessels and tubules that dictates active reabsorption of sodium in a milieu poor in oxygen (Figure 1).1 In this review, we describe how hypoxia of the medulla may relate to susceptibility to acute and chronic renal injury. The Renal Medullary Concentrating Mechanism as . . . | Hypoxia of the renal medulla--its implications for disease. |
29526125 | BACKGROUND A major challenge for physicians is to identify patients with acute coronary syndromes who may benefit from treatment with glycoprotein-IIb/IIIa-receptor antagonists. We investigated whether troponin concentrations can be used to stratify patients for benefit from treatment with tirofiban.
METHODS We enrolled 2222 patients of the Platelet Receptor Inhibition in Ischemic Syndrome Management study with coronary artery disease and who had had chest pain in the previous 24 h. All patients received aspirin and were randomly assigned treatment with tirofiban or heparin. We took baseline measurements of troponin I and troponin T. We recorded death, myocardial infarction, or recurrent ischaemia after 48 h infusion treatment and at 7 days and 30 days.
FINDINGS 629 (28.3%) patients had troponin I concentrations higher than the diagnostic threshold of 1.0 microg/L and 644 (29.0%) troponin T concentrations higher than 0.1 microg/L. 30-day event rates (death, myocardial infarction) were 13.0% for troponin-I-positive patients compared with 4.9% for troponin-I-negative patients (p<0.0001), and 13.7% compared wth 3.5% for troponin T (p<0.001). At 30 days, in troponin-I-positive patients, tirofiban had lowered the risk of death (adjusted hazard ratio 0.25 [95% CI 0.09-0.68], p=0.004) and myocardial infarction (0.37 [0.16-0.84], p=0.01). This benefit was seen in medically managed patients (0.30 [0.10-0.84], p=0.004) and those undergoing revascularisation (0.37 [0.15-0.93] p=0.02) after 48 h infusion treatment. By contrast, no treatment effect was seen for troponin-I-negative patients. Similar benefits were seen for troponin-T-positive patients.
INTERPRETATION Troponin I and troponin T reliably identified high-risk patients with acute coronary syndromes, managed medically and by revascularisation, who would benefit from tirofiban. | Troponin concentrations for stratification of patients with acute coronary syndromes in relation to therapeutic efficacy of tirofiban. PRISM Study Investigators. Platelet Receptor Inhibition in Ischemic Syndrome Management. |
29557235 | Ubiquitin functions by covalently modifying other proteins. In the past few years, a surprising number of other proteins have been identified that, despite often being only slightly similar to ubiquitin, can also be attached to proteins. Newly discovered parallels between the activation of ubiquitin and the biosynthesis of certain enzyme cofactors now hint at the possible evolutionary origins of the ubiquitin system. | Evolution and function of ubiquitin-like protein-conjugation systems |
29564505 | IMPORTANCE Exacerbations of respiratory symptoms in chronic obstructive pulmonary disease (COPD) have profound and long-lasting adverse effects on patients.
OBJECTIVE To test the hypothesis that elevated levels of inflammatory biomarkers in individuals with stable COPD are associated with an increased risk of having exacerbations.
DESIGN, SETTING, AND PARTICIPANTS Prospective cohort study examining 61,650 participants with spirometry measurements from the Copenhagen City Heart Study (2001-2003) and the Copenhagen General Population Study (2003-2008). Of these, 6574 had COPD, defined as a ratio between forced expiratory volume in 1 second (FEV1) and forced vital capacity below 0.7.
MAIN OUTCOMES AND MEASURES Baseline levels of C-reactive protein (CRP) and fibrinogen and leukocyte count were measured in participants at a time when they were not experiencing symptoms of exacerbations. Exacerbations were recorded and defined as short-course treatment with oral corticosteroids alone or in combination with an antibiotic or as a hospital admission due to COPD. Levels of CRP and fibrinogen and leukocyte count were defined as high or low according to cut points of 3 mg/L, 14 μmol/L, and 9 ×10(9)/L, respectively.
RESULTS During follow-up, 3083 exacerbations were recorded (mean, 0.5/participant). In the first year of follow-up, multivariable-adjusted odds ratios for having frequent exacerbations were 1.2 (95% CI, 0.7-2.2; 17 events/1000 person-years) for individuals with 1 high biomarker, 1.7 (95% CI, 0.9-3.2; 32 events/1000 person-years) for individuals with 2 high biomarkers, and 3.7 (95% CI, 1.9-7.4; 81 events/1000 person-years) for individuals with 3 high biomarkers compared with individuals who had no elevated biomarkers (9 events/1000 person-years; trend: P = 2 × 10(-5)). Corresponding hazard ratios using maximum follow-up time were 1.4 (95% CI, 1.1-1.8), 1.6 (95% CI, 1.3-2.2), and 2.5 (95% CI, 1.8-3.4), respectively (trend: P = 1 × 10(-8)). The addition of inflammatory biomarkers to a basic model including age, sex, FEV1 percent predicted, smoking, use of any inhaled medication, body mass index, history of previous exacerbations, and time since most recent prior exacerbation improved the C statistics from 0.71 to 0.73 (comparison: P = 9 × 10(-5)). Relative risks were consistent in those with milder COPD, in those with no history of frequent exacerbations, and in the 2 studies separately. The highest 5-year absolute risks of having frequent exacerbations in those with 3 high biomarkers (vs no high biomarkers) were 62% (vs 24%) for those with Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades C-D (n = 558), 98% (vs 64%) in those with a history of frequent exacerbations (n = 127), and 52% (vs 15%) for those with GOLD grades 3-4 (n = 465).
CONCLUSIONS AND RELEVANCE Simultaneously elevated levels of CRP and fibrinogen and leukocyte count in individuals with COPD were associated with increased risk of having exacerbations, even in those with milder COPD and in those without previous exacerbations. Further investigation is needed to determine the clinical value of these biomarkers for risk stratification. | Inflammatory biomarkers and exacerbations in chronic obstructive pulmonary disease. |
29634262 | Over the last decade, gene supplementation therapy for inherited retinal degeneration has come of age. Early proof-of-concept studies in animal models of disease showed modest, but genuine improvements in retinal function and/or survival. Further development of the vectors used for gene transfer to the retina has led to better treatment efficacy in a wide variety of animal models, leading in 2008 to the initiation of three clinical trials for Leber congenital amaurosis caused by retinal pigment epithelium 65 deficiency. The results from these trials suggest that the treatment of inherited retinal dystrophy by gene therapy can be safe and effective. Here, we examine the progress of gene supplementation therapy in the retina, and discuss the potential for using gene therapy to treat different forms of inherited retinal degeneration. | Gene supplementation therapy for recessive forms of inherited retinal dystrophies |
29638116 | Defined genetic models based on human pluripotent stem cells have opened new avenues for understanding disease mechanisms and drug screening. Many of these models assume cell-autonomous mechanisms of disease but it is possible that disease phenotypes or drug responses will only be evident if all cellular and extracellular components of a tissue are present and functionally mature. To derive optimal benefit from such models, complex multicellular structures with vascular components that mimic tissue niches will thus likely be necessary. Here we consider emerging research creating human tissue mimics and provide some recommendations for moving the field forward. | Complex Tissue and Disease Modeling using hiPSCs. |
29641682 | Pluripotent cells arise within the inner cell mass (ICM) of mammals and have the potential to generate all cell types of the adult organism through a process of commitment and ordered differentiation. Despite many decades of investigation, the mechanisms that guide and stabilise cell fate choice as well as those that can be engineered to promote its reversal, remain only partially resolved. Reprogramming of somatic cells towards a pluripotent-like state can be achieved by several different experimental routes including nuclear transfer, the supply of a defined cocktail of transcription factors, or by fusing somatic cells with a pluripotent stem cell partner. These approaches have been used to demonstrate the remarkable intrinsic epigenetic plasticity of many terminally differentiated cell types, as well as to define the factors that are required for pluripotent conversion. In this review we summarise some recent advances using cell fusion-based studies to better understand the basis of pluripotency and the epigenetic mechanisms that promote cell type inter-conversion. | Reprogramming somatic cells towards pluripotency by cellular fusion. |
29657303 | Anorectic drugs have been used for more than 30 years as an aid in weight reduction for obese persons. The use of aminorex, an amphetamine analog that increases norepinephrine levels in the central nervous system, led to an epidemic of primary pulmonary hypertension (PPH) in Europe in the late 1960s and early 1970s. The use of fenfluramine and later dexfenfluramine [drugs that inhibit 5-hydroxytryptamine (5-HT) release and reuptake and increases 5-HT and thus 5-HT secretion in the brain] was associated with a second epidemic of PPH. All of these drugs have been voluntarily withdrawn from the market. The pathogenesis of PPH in patients treated with these agents is uncertain, but recent evidence suggests that potassium channel abnormalities and vasoactive and proliferative properties of 5-HT may play a role. There is increasing experimental evidence suggesting that aminorex, fenfluramine and dexfenfluramine inhibit 4-aminopyridine-sensitive currents in potassium channels resulting in vasoconstriction in pulmonary resistance vessels and perhaps smooth muscle cell proliferation. 5-HT causes pulmonary artery vasoconstriction and smooth muscle cell proliferation. Its levels are known to be high in those with fenfluramine-induced PPH. However, a firm cause-and-effect relationship has not yet been established. One potentially beneficial effect of the epidemics of anorectic-related PPH is that it may have provided important insights into the causes of PPH unrelated to anorectic agents. | Anorectic drugs and pulmonary hypertension from the bedside to the bench. |
29689140 | Dysregulated Wnt signaling is seen in approximately 30% of hepatocellular carcinomas; thus, finding pathways downstream of the activation of Wnt signaling is key. Here, using cre-lox technology, we deleted the Apc gene in the adult mouse liver and observed a rapid increase in nuclear beta-catenin and c-Myc, which is associated with an induction of proliferation that led to hepatomegaly within 4 days of gene deletion. To investigate the downstream pathways responsible for these phenotypes, we analyzed the impact of inactivating APC in the context of deficiency of the potentially key effectors beta-catenin and c-Myc. beta-catenin loss rescues both the proliferation and hepatomegaly phenotypes after APC loss. However, c-Myc deletion, which rescues the phenotypes of APC loss in the intestine, had no effect on the phenotypes of APC loss in the liver. The consequences of the deregulation of the Wnt pathway within the liver are therefore strikingly different from those observed within the intestine, with the vast majority of Wnt targets being beta-catenin-dependent but c-Myc-independent in the liver. | B-catenin deficiency, but not Myc deletion, suppresses the immediate phenotypes of APC loss in the liver. |
29691654 | Until recently, the mechanism of adaptive thermogenesis was ascribed to the expression of uncoupling protein 1 (UCP1) in brown and beige adipocytes. UCP1 is known to catalyze a proton leak of the inner mitochondrial membrane, resulting in uncoupled oxidative metabolism with no production of adenosine triphosphate and increased energy expenditure. Thus increasing brown and beige adipose tissue with augmented UCP1 expression is a viable target for obesity-related disorders. Recent work demonstrates an UCP1-independent pathway to uncouple mitochondrial respiration. A secreted enzyme, PM20D1, enriched in UCP1+ adipocytes, exhibits catalytic and hydrolytic activity to reversibly form N-acyl amino acids. N-acyl amino acids act as endogenous uncouplers of mitochondrial respiration at physiological concentrations. Administration of PM20D1 or its products, N-acyl amino acids, to diet-induced obese mice improves glucose tolerance by increasing energy expenditure. In short-term studies, treated animals exhibit no toxicity while experiencing 10% weight loss primarily of adipose tissue. Further study of this metabolic pathway may identify novel therapies for diabesity, the disease state associated with diabetes and obesity. | Uncoupling Mitochondrial Respiration for Diabesity. |
29723642 | The prodynorphin gene (PDYN) encoding the anticonvulsant peptide dynorphin is a strong candidate for a seizure suppressor gene and thus a possible modulator of susceptibility to temporal lobe epilepsy. We performed a case control association study in 155 patients with nonlesional temporal lobe epilepsy and 202 controls and found that PDYN promotor low-expression L-alleles confer an increased risk for temporal lobe epilepsy in patients with a family history for seizures. Irrespective of the familial background, L-homozygotes display a higher risk for secondarily generalized seizures and status epilepticus. | A functional polymorphism in the prodynorphin gene promotor is associated with temporal lobe epilepsy. |
29735200 | Dry beans and soybeans are nutrient-dense, fiber-rich, and are high-quality sources of protein. Protective and therapeutic effects of both dry bean and soybean intake have been documented. Studies show that dry bean intake has the potential to decrease serum cholesterol concentrations, improve many aspects of the diabetic state, and provide metabolic benefits that aid in weight control. Soybeans are a unique source of the isoflavones genistein and diadzein, which have numerous biological functions. Soybeans and soyfoods potentially have multifaceted health-promoting effects, including cholesterol reduction, improved vascular health, preserved bone mineral density, and reduction of menopausal symptoms. Soy appears to have salutary effects on renal function, although these effects are not well understood. Whereas populations consuming high intakes of soy have lower prevalences of certain cancers, definitive experimental data are insufficient to clarify a protective role of soy. The availability of legume products and resources is increasing, incorporating dry beans and soyfoods into the diet can be practical and enjoyable. With the shift toward a more plant-based diet, dry beans and soy will be potent tools in the treatment and prevention of chronic disease. | Cardiovascular and renal benefits of dry bean and soybean intake. |
29745822 | A change in the probability of neurotransmitter release (Pr) is an important mechanism underlying synaptic plasticity. Although Pr is often assumed to be the same for all terminals at a single synapse, this assumption is difficult to reconcile with the nonuniform size and structure of synaptic terminals in the central nervous system. Release probability was measured at excitatory synapses on cultured hippocampal neurons by analysis of the progressive block of N-methyl-D-aspartate receptor-mediated synaptic currents by the irreversible open channel blocker MK-801. Release probability was nonuniform (range of 0.09 to 0.54) for terminals arising from a single axon, the majority of which had a low Pr. However, terminals with high Pr are more likely to be affected by the activity-dependent modulation that occurs in long-term potentiation. | Nonuniform probability of glutamate release at a hippocampal synapse. |
29785642 | Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is the only described systemic autoimmune disease with established monogenic background, and the first autoimmune disorder localized outside the major histocompatibility complex (MHC) region. The primary biochemical defect in APECED is unknown. We have isolated a novel gene, AIRE, encoding for a putative nuclear protein featuring two PHD-type zinc-finger motifs, suggesting its involvement in transcriptional regulation. Five mutations in AIRE are reported in individuals with this disorder. This is the first report of a single-gene defect causing a systemic human autoimmune disease, providing a tool for exploring the molecular basis of autoimmunity. | An autoimmune disease, APECED, caused by mutations in a novel gene featuring two PHD-type zinc-finger domains |
29788648 | NuA4, the major H4 lysine acetyltransferase (KAT) complex in Saccharomyces cerevisiae, is recruited to promoters and stimulates transcription initiation. NuA4 subunits contain domains that bind methylated histones, suggesting that histone methylation should target NuA4 to coding sequences during transcription elongation. We show that NuA4 is cotranscriptionally recruited, dependent on its physical association with elongating polymerase II (Pol II) phosphorylated on the C-terminal domain by cyclin-dependent kinase 7/Kin28, but independently of subunits (Eaf1 and Tra1) required for NuA4 recruitment to promoters. Whereas histone methylation by Set1 and Set2 is dispensable for NuA4's interaction with Pol II and targeting to some coding regions, it stimulates NuA4-histone interaction and H4 acetylation in vivo. The NuA4 KAT, Esa1, mediates increased H4 acetylation and enhanced RSC occupancy and histone eviction in coding sequences and stimulates the rate of transcription elongation. Esa1 cooperates with the H3 KAT in SAGA, Gcn5, to enhance these functions. Our findings delineate a pathway for acetylation-mediated nucleosome remodeling and eviction in coding sequences that stimulates transcription elongation by Pol II in vivo. | NuA4 lysine acetyltransferase Esa1 is targeted to coding regions and stimulates transcription elongation with Gcn5. |
29806339 | Targeting mitotic exit has been recently proposed as a relevant therapeutic approach against cancer. By using genetically engineered mice, we show that the APC/C cofactor Cdc20 is essential for anaphase onset in vivo in embryonic or adult cells, including progenitor/stem cells. Ablation of Cdc20 results in efficient regression of aggressive tumors, whereas current mitotic drugs display limited effects. Yet, Cdc20 null cells can exit from mitosis upon inactivation of Cdk1 and the kinase Mastl (Greatwall). This mitotic exit depends on the activity of PP2A phosphatase complexes containing B55α or B55δ regulatory subunits. These data illustrate the relevance of critical players of mitotic exit in mammals and their implications in the balance between cell death and mitotic exit in tumor cells. | Targeting mitotic exit leads to tumor regression in vivo: Modulation by Cdk1, Mastl, and the PP2A/B55α,δ phosphatase. |
29807737 | DrugBank (www.drugbank.ca) is a web-enabled database containing comprehensive molecular information about drugs, their mechanisms, their interactions and their targets. First described in 2006, DrugBank has continued to evolve over the past 12 years in response to marked improvements to web standards and changing needs for drug research and development. This year's update, DrugBank 5.0, represents the most significant upgrade to the database in more than 10 years. In many cases, existing data content has grown by 100% or more over the last update. For instance, the total number of investigational drugs in the database has grown by almost 300%, the number of drug-drug interactions has grown by nearly 600% and the number of SNP-associated drug effects has grown more than 3000%. Significant improvements have been made to the quantity, quality and consistency of drug indications, drug binding data as well as drug-drug and drug-food interactions. A great deal of brand new data have also been added to DrugBank 5.0. This includes information on the influence of hundreds of drugs on metabolite levels (pharmacometabolomics), gene expression levels (pharmacotranscriptomics) and protein expression levels (pharmacoprotoemics). New data have also been added on the status of hundreds of new drug clinical trials and existing drug repurposing trials. Many other important improvements in the content, interface and performance of the DrugBank website have been made and these should greatly enhance its ease of use, utility and potential applications in many areas of pharmacological research, pharmaceutical science and drug education. | DrugBank 5.0: a major update to the DrugBank database for 2018 |
29828242 | The development of in vitro assays to analyze pre-mRNA splicing resulted in the discovery of many fundamental features characterizing splicing signals and the machinery that completes this process. Because in vitro assays can be manipulated by various biochemical approaches, the versatility of investigating alternative pre-mRNA splicing in the test tube appears endless. Importantly, modifications in reaction conditions can lead to the accumulation, isolation, and characterization of reaction intermediates, a prerequisite for gaining mechanistic insights into how the spliceosome carries out intron removal, and how regulatory elements assist the general splicing machinery in defining splice sites and alternative exons. These considerable experimental advantages have made the in vitro splicing system a standard assay, even though this approach is independent from RNA transcription and other RNA processing events, and in some respects deviates from the natural process of mRNA biogenesis. Here, we describe the tools and techniques necessary to carry out in vitro splicing assays. Analyses of various experimental designs are presented to highlight the approaches taken to gain insights into the mechanisms by which splice site recognition and activation are communicated with the general splicing machinery. Methods to measure the kinetics of splicing, to observe the formation of the pre-spliceosomal complexes, and to manipulate and modify the in vitro system to resolve the regulatory influences in alternative splicing are presented. | Analyzing mechanisms of alternative pre-mRNA splicing using in vitro splicing assays. |
29845974 | Medicines are a major treatment modality for many mental illnesses, and with the growing burden of mental disorders worldwide pharmacists are ideally positioned to play a greater role in supporting people with a mental illness. This narrative review aims to describe the evidence for pharmacist-delivered services in mental health care and address the barriers and facilitators to increasing the uptake of pharmacist services as part of the broader mental health care team. This narrative review is divided into three main sections: (1) the role of the pharmacist in mental health care in multidisciplinary teams and in supporting early detection of mental illness; (2) the pharmacists' role in supporting quality use of medicines in medication review, strategies to improve medication adherence and antipsychotic polypharmacy, and shared decision making; and (3) barriers and facilitators to the implementation of mental health pharmacy services with a focus on organizational culture and mental health stigma. In the first section, the review presents new roles for pharmacists within multidisciplinary teams, such as in case conferencing or collaborative drug therapy management; and new roles that would benefit from increased pharmacist involvement, such as the early detection of mental health conditions, development of care plans and follow up of people with mental health problems. The second section describes the impact of medication review services and other pharmacist-led interventions designed to reduce inappropriate use of psychotropic medicines and improve medication adherence. Other new potential roles discussed include the management of antipsychotic polypharmacy and involvement in patient-centered care. Finally, barriers related to pharmacists' attitudes, stigma and skills in the care of patients with mental health problems and barriers affecting pharmacist-physician collaboration are described, along with strategies to reduce mental health stigma. | New Roles for Pharmacists in Community Mental Health Care: A Narrative Review |
29851836 | We show that DNA replication activity in extracts of human HeLa cells decreases following UV irradiation. Alterations in replication activity in vitro parallel the UV-induced block in cell cycle progression of these cells in culture. UV irradiation also induces specific changes in the pattern of phosphorylation of the 34 kDa subunit of a DNA replication protein, human single-stranded DNA-binding protein (hSSB). The appearance of a hyperphosphorylated form of hSSB correlates with reduced in vitro DNA replication activity in extracts of UV-irradiated cells. Replication activity can be restored to these extracts in vitro by addition of purified hSSB. These results suggest that UV-induced DNA synthesis arrest may be mediated in part through phosphorylation-related alterations in the activity of hSSB, an essential component of the DNA replication apparatus. | UV light-induced DNA synthesis arrest in HeLa cells is associated with changes in phosphorylation of human single-stranded DNA-binding protein. |
29863668 | The P446L mutant Drosophila importin-beta (P446L-imp-beta) has been reported to prohibit--in dominant negative fashion--nuclear envelope (NE) assembly. Along elucidating the mode of action of P446L-imp-beta we studied in vitro NE assembly on Sepharose beads. While Drosophila embryo extracts support NE assembly over Sepharose beads coated with Ran, NE assembly does not take place in extracts supplied with exogenous P446L-imp-beta. A NE also forms over importin-beta-coated beads. Surprisingly, when immobilized to Sepharose beads P446L-imp-beta as efficiently recruits NE vesicles as normal importin-beta. The discrepancy in behavior of cytoplasmic and bead-bound P446L-imp-beta appears to be related to icreased--as compared to normal importin-beta--microtubule (MT) binding ability of P446L-imp-beta. While wild-type importin-beta is able to bind MTs and the binding decreases upon RanGTP interaction, P446L-imp-beta cannot be removed from the MTs by RanGTP. P446L-imp-beta, like normal importin-beta, binds some types of the nucleoporins that have been known to be required for NE assembly at the end of mitosis. It appears that the inhibitory effect of P446L-imp-beta on NE assembly is caused by sequestering some of the nucleoporins required for NE assembly to the MTs. | P446L-importin-beta inhibits nuclear envelope assembly by sequestering nuclear envelope assembly factors to the microtubules. |
29877890 | Recent structures of the nucleosome core particle reveal details of histone-histone and histone-DNA interactions. These structures have now set the stage for understanding chromatin assembly and dynamics during replication and transcription. Histone chaperones and chromatin remodeling complexes are important in both of these processes. The nucleosome and its protein core, the histone octamer, have twofold symmetry, which histone chaperones may use to bind core histones. Recent studies suggest that the nucleoplasmin pentamer may mediate histone storage, sperm chromatin decondensation and nucleosome assembly, by dimerizing to form a decamer. In this model, histone binding on the lateral surface of the chaperone involves stereospecific interactions and a shared twofold axis. | Histone chaperones and nucleosome assembly. |
29947146 | BACKGROUND Obesity is an epidemic that affects 1 in 3 individuals in the United States, and recent evidence suggests that enteric microbiota may play a significant role in the development of obesity. This study evaluated the association between methanogenic archaea and obesity in human subjects.
METHODS Subjects with a body mass index (BMI) of 30 kg/m² or higher were prospectively recruited from the weight loss program of a tertiary care medical center. Subjects who met the study's inclusion criteria were asked to complete a questionnaire that included a series of visual analogue scores for bowel symptom severities. Subjects then provided a single end-expiratory breath sample to quantitate methane levels. Bivariate and multivariate analyses were used to determine associations with BMI.
RESULTS A total of 58 patients qualified for enrollment. Twenty percent of patients (n = 12) had breath test results that were positive for methane (>3 parts per million [ppm]), with a mean breath methane concentration of 12.2±3.1 ppm. BMI was significantly higher in methane-positive subjects (45.2±2.3 kg/m²) than in methane-negative subjects (38.5±0.8 kg/m²; P=.001). Methane-positive subjects also had a greater severity of constipation than methane-negative subjects (21.3±6.4 vs 9.5±2.4; P=.043). Multiple regression analysis illustrated a significant association between BMI and methane, constipation, and antidepressant use. However, methane remained an independent predictor of elevated BMI when controlling for antidepressant use (P<.001) and when controlling for both constipation and antidepressant use (6.55 kg/m² greater BMI; P=.003).
CONCLUSION This is the first human study to demonstrate that a higher concentration of methane detected by breath testing is a predictor of significantly greater obesity in overweight subjects. | Intestinal methane production in obese individuals is associated with a higher body mass index. |
29955650 | OBJECTIVE To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance.
DESIGN Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance.
SETTING 70 general practices throughout England.
PARTICIPANTS 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients.
MAIN OUTCOME MEASURES Incidence of infectious intestinal disease in community and reported to general practice.
RESULTS 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified.
CONCLUSIONS Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered. | Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance. The Infectious Intestinal Disease Study Executive. |
29981186 | BACKGROUND Venous thromboembolism (VTE) is a common complication in cancer patients and a significant cause of morbidity and mortality. However, little information is available on oncologists' perceptions of the risk of VTE and its management. The Fundamental Research in Oncology and Thrombosis (FRONTLINE) study is the first comprehensive global survey of thrombosis and cancer. The study was designed to collect data on the perceived risk and patterns of practice with regard to VTE in cancer patients undergoing surgical and medical management of their malignancy and to provide information on international and regional practice patterns, allowing for the design of research studies to answer the concerns of practicing clinicians.
METHODS Literature reviews were performed to provide a current evidence base against which to compare the findings, and a survey was developed under the guidance of an advisory board. A paper-based reply-paid questionnaire was distributed globally between July and November 2001 to clinicians involved in cancer care and was made available on a dedicated website.
FINDINGS A total of 3,891 completed responses were available for analysis. Brain and pancreatic tumors were considered to carry a high risk for VTE, and 80% of respondents considered the use of central venous lines to be associated with a high risk of VTE. Marked differences were seen in the use of thromboprophylaxis for surgical and medical cancer patients, with over 50% of surgeons reporting that they initiated thromboprophylaxis routinely, while most medical oncologists reported using thromboprophylaxis in less than 5% of medical patients. Low molecular weight heparin (LMWH) was the most popular method of thromboprophylaxis employed in both surgical and medical patients and was more favored by European than U.S. clinicians. Some 20% of respondents reported using aspirin for prophylaxis, despite there being no reliable evidence for this agent as effective in prevention in this population. For the treatment of VTE, LMWH was again the most common initial treatment, although, for the long-term, oral anticoagulation therapy was widely adopted. Many patients were treated for VTE on an outpatient basis, and secondary prevention of VTE was typically continued for 3 to 6 months after an episode of deep vein thrombosis or for longer in the case of pulmonary embolism.
INTERPRETATION The results of the FRONTLINE survey demonstrate a need for guidelines to direct clinical practice in line with evidence-based data concerning cancer and VTE. Oncologists need to be educated regarding the true risks of VTE associated with certain cancers and on strategies for prevention and treatment to reduce the morbidity and mortality associated with VTE in all cancer patients. The study has also helped identify areas for future research. | Venous thrombosis in cancer patients: insights from the FRONTLINE survey. |
30034334 | Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and the associated proteins (Cas) comprise a system of adaptive immunity against viruses and plasmids in prokaryotes. Cas1 is a CRISPR-associated protein that is common to all CRISPR-containing prokaryotes but its function remains obscure. Here we show that the purified Cas1 protein of Escherichia coli (YgbT) exhibits nuclease activity against single-stranded and branched DNAs including Holliday junctions, replication forks and 5'-flaps. The crystal structure of YgbT and site-directed mutagenesis have revealed the potential active site. Genome-wide screens show that YgbT physically and genetically interacts with key components of DNA repair systems, including recB, recC and ruvB. Consistent with these findings, the ygbT deletion strain showed increased sensitivity to DNA damage and impaired chromosomal segregation. Similar phenotypes were observed in strains with deletion of CRISPR clusters, suggesting that the function of YgbT in repair involves interaction with the CRISPRs. These results show that YgbT belongs to a novel, structurally distinct family of nucleases acting on branched DNAs and suggest that, in addition to antiviral immunity, at least some components of the CRISPR-Cas system have a function in DNA repair. | A dual function of the CRISPR-Cas system in bacterial antivirus immunity and DNA repair. |
30041340 | BACKGROUND Histone deimination regulates gene function and contributes to antimicrobial response, allowing the formation of neutrophil extracellular traps (NETs). Deiminated proteins are target of anti-citrullinated peptides antibodies (ACPA) in rheumatoid arthritis (RA).
OBJECTIVE The objective of this paper is to test the hypothesis that RA sera react with deiminated histones contained in NETs.
METHODS Neutrophils from peripheral blood were stimulated with A23187 and acid treated; NETosis was induced by phorbol myristate acetate, and NET proteins were isolated. Sera were tested by immunoblot on acid extracted proteins from neutrophils and from NETs, and by ELISA on deiminated histone H4 or H4-derived peptides. Bands reactive with RA sera were excised from gels, digested with trypsin and subjected to matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) analysis, before and after derivatisation to detect citrullinated peptides.
RESULTS RA sera reacted with a deiminated antigen of 11 KDa from activated neutrophils, recognised also by anti-H4 and antideiminated H4 antibodies. A similar reactivity was observed with NET proteins. The antigen from neutrophils or NETs was identified as citrullinated H4 by MALDI-TOF analysis. By ELISA, RA sera bound in vitro citrullinated H4. Citrullinated H4 14-34 and 31-50 peptides detected antibodies in 67% and 63% of RA sera and in less than 5% of controls; antibody titre was correlated with anti-CCP2.
CONCLUSIONS Citrullinated H4 from activated neutrophils and NETs is a target of antibodies in RA, and synthetic citrullinated H4-derived peptides are a new substrate for ACPA detection. As NETosis can generate antigens for ACPA, these data suggest a novel connection between innate and adaptive immunity in RA. | Antibodies from patients with rheumatoid arthritis target citrullinated histone 4 contained in neutrophils extracellular traps. |
30041895 | KEY POINTS The gastrointestinal epithelial enterochromaffin (EC) cell synthesizes the vast majority of the body's serotonin. As a specialized mechanosensor, the EC cell releases this serotonin in response to mechanical forces. However, the molecular mechanism of EC cell mechanotransduction is unknown. In the present study, we show, for the first time, that the mechanosensitive ion channel Piezo2 is specifically expressed by the human and mouse EC cells. Activation of Piezo2 by mechanical forces results in a characteristic ionic current, the release of serotonin and stimulation of gastrointestinal secretion. Piezo2 inhibition by drugs or molecular knockdown decreases mechanosensitive currents, serotonin release and downstream physiological effects. The results of the present study suggest that the mechanosensitive ion channel Piezo2 is specifically expressed by the EC cells of the human and mouse small bowel and that it is important for EC cell mechanotransduction. ABSTRACT The enterochromaffin (EC) cell in the gastrointestinal (GI) epithelium is the source of nearly all systemic serotonin (5-hydroxytryptamine; 5-HT), which is an important neurotransmitter and endocrine, autocrine and paracrine hormone. The EC cell is a specialized mechanosensor, and it is well known that it releases 5-HT in response to mechanical forces. However, the EC cell mechanotransduction mechanism is unknown. The present study aimed to determine whether Piezo2 is involved in EC cell mechanosensation. Piezo2 mRNA was expressed in human jejunum and mouse mucosa from all segments of the small bowel. Piezo2 immunoreactivity localized specifically within EC cells of human and mouse small bowel epithelium. The EC cell model released 5-HT in response to stretch, and had Piezo2 mRNA and protein, as well as a mechanically-sensitive inward non-selective cation current characteristic of Piezo2. Both inward currents and 5-HT release were inhibited by Piezo2 small interfering RNA and antagonists (Gd3+ and D-GsMTx4). Jejunum mucosal pressure increased 5-HT release and short-circuit current via submucosal 5-HT3 and 5-HT4 receptors. Pressure-induced secretion was inhibited by the mechanosensitive ion channel antagonists gadolinium, ruthenium red and D-GsMTx4. We conclude that the EC cells in the human and mouse small bowel GI epithelium selectively express the mechanosensitive ion channel Piezo2, and also that activation of Piezo2 by force leads to inward currents, 5-HT release and an increase in mucosal secretion. Therefore, Piezo2 is critical to EC cell mechanosensitivity and downstream physiological effects. | Mechanosensitive ion channel Piezo2 is important for enterochromaffin cell response to mechanical forces |
30058568 | CONTEXT Managing thoracic aortic aneurysms identified incidentally by increased use of computed tomography, echocardiography, and magnetic resonance imaging is problematic, especially in the elderly.
OBJECTIVE To ascertain whether the previously reported poor prognosis for individuals with thoracic aortic aneurysms has changed with better medical therapies and improved surgical techniques that can now be applied to aneurysm management.
DESIGN Population-based cohort study.
SETTING AND PATIENTS All 133 patients with the diagnosis of degenerative thoracic aortic aneurysms among Olmsted County, Minnesota, residents between 1980 and 1994 compared with a previously reported cohort of similar patients between 1951 and 1980.
MAIN OUTCOME MEASURES The primary clinical end points were incidence, cumulative rupture risk, rupture risk as a function of aneurysm size, and survival.
RESULTS In contrast to abdominal aortic aneurysms, for which men are affected predominately, 51% of thoracic aortic aneurysms were identified in women who were considerably older at recognition than men (mean age, 75.9 vs 62.8 years, respectively; P= .01). The overall incidence rate of 10.4 per 100000 person-years (95% confidence interval [CI], 8.6-12.2) between 1980 and 1994 was more than 3-fold higher than the rate from 1951 to 1980. The cumulative risk of rupture was 20% after 5 years. Seventy-nine percent of ruptures occurred in women (P= .01). The 5-year risk of rupture as a function of aneurysm size at recognition was 0% for aneurysms less than 4 cm in diameter, 16% (95% CI, 4%-28%) for those 4 to 5.9 cm, and 31% (95% CI, 5%-56%) for aneurysms 6 cm or more. Overall 5-year survival improved to 56% (95% CI, 48%-66%) between 1980 and 1994 compared with only 19% between 1951 and 1980 (P<.01).
CONCLUSIONS In this population, elderly women represent an increasing portion of all patients with clinically recognized thoracic aortic aneurysms and constitute the majority of patients whose aneurysm eventually ruptures. Overall survival for thoracic aortic aneurysms has improved significantly in the past 15 years. | Improved prognosis of thoracic aortic aneurysms: a population-based study. |
30101891 | The authors reviewed hospital records of 13 patients with status epilepticus and hypotension who received IV valproate therapy. Most patients were elderly (74.4 +/- 12.5 [SD] years) and received a loading dose of valproate of 25.1 +/- 5.0 mg/kg (range 14.7 to 32.7), at a rate of 36.6 +/- 25.1 mg/min (range 6.3 to 100). There were no significant changes in blood pressure, pulse, or use of vasopressors. The data suggest that valproate loading is well tolerated, even in patients with cardiovascular instability. | Intravenous valproate is well tolerated in unstable patients with status epilepticus. |
30122260 | DNA double-strand breaks (DSBs) are highly hazardous for genome integrity because they have the potential to cause mutations, chromosomal rearrangements and genomic instability. The cellular response to DSBs is orchestrated by signal transduction pathways, known as DNA damage checkpoints, which are conserved from yeasts to humans. These pathways can sense DNA damage and transduce this information to specific cellular targets, which in turn regulate cell cycle transitions and DNA repair. The mammalian protein kinases ATM and ATR, as well as their budding yeast corresponding orthologs Tel1 and Mec1, act as master regulators of the checkpoint response to DSBs. Here, we review the early steps of DSB processing and the role of DNA-end structures in activating ATM/Tel1 and ATR/Mec1 in an orderly and reciprocal manner. | Interplays between ATM/Tel1 and ATR/Mec1 in sensing and signaling DNA double-strand breaks. |
30152134 | Progressive advances using zebrafish as a model organism have provided hematologists with an additional genetic system to study blood cell formation and hematological malignancies. Despite extensive evolutionary divergence between bony fish (teleosts) and mammals, the molecular pathways governing hematopoiesis have been highly conserved. As a result, most (if not all) of the critical hematopoietic transcription factor genes identified in mammals have orthologues in zebrafish. As in other vertebrates, all of the teleost blood lineages are believed to originate from a pool of pluripotent, self-renewing hematopoietic stem cells. Here, we provide a detailed review of the timing, anatomical location, and transcriptional regulation of zebrafish ‘primitive’ and ‘definitive’ hematopoiesis as well as discuss a model of T-cell leukemia and recent advances in blood cell transplantation. Given that many of the regulatory genes that control embryonic hematopoiesis have been implicated in oncogenic pathways in adults, an understanding of blood cell ontogeny is likely to provide insights into the pathophysiology of human leukemias. | The ‘definitive’ (and ‘primitive’) guide to zebrafish hematopoiesis |
30184745 | We have provided a historical perspective on a body of steroid receptor research dealing with the structure and physiological significance of the untransformed 9S receptor that has often confused both novice and expert investigators. The frequent controversies and equivocations of earlier studies were due to the fact that the native, hormone-free state of these receptors is a large multiprotein complex that resisted description for many years because of its unstable and dynamic nature. The untransformed 9S state of the steroid and dioxin receptors has provided a unique system for studying the function of the ubiquitous, abundant, and conserved heat shock protein, hsp90. The hormonal control of receptor association with hsp90 provided a method of manipulating the receptor heterocomplex in a manner that was physiologically meaningful. For several steroid receptors, binding to hsp90 was required for the receptor to be in a native hormone-binding state, and for all of the receptors, hormone binding promoted dissociation of the receptor from hsp90 and conversion of the receptor to the DNA-binding state. Although the complexes between tyrosine kinases and hsp90 were discovered earlier, the hormonal regulation or steroid receptor association with hsp90 permitted much more rapid and facile study of hsp90 function. The observations that hsp90 binds to the receptors through their HBDs and that these domains can be fused to structurally different proteins bringing their function under hormonal control provided a powerful linkage between the hormonal regulation of receptor binding to hsp90 and the initial step in steroid hormone action. Because the 9S receptor hsp90 heterocomplexes could be physically stabilized by molybdate, their protein composition could be readily studied, and it became clear that these complexes are multiprotein structures containing a number of unique proteins, such as FKBP51, FKBP52, CyP-40, and p23, that were discovered because of their presence in these structures. Further analysis showed that hsp90 itself exists in a variety of native multiprotein heterocomplexes independent of steroid receptors and other 'substrate' proteins. Cell-free systems can now be used to study the formation of receptor heterocomplexes. As we outlined in the scheme of Fig. 1, the multicomponent receptor-hsp90 heterocomplex assembly system is being reconstituted, and the importance of individual proteins, such as hsp70, p60, and p23, in the assembly process is becoming recognized. It should be noted that our understanding of the mechanism and purpose of steroid receptor heterocomplex assembly is still at an early stage. We can now speculate on the roles of receptor-associated proteins in receptor action, both as individuals and as a group, but their actual functions are still vague or unknown. We can make realistic models about the chaperoning and trafficking of steroid receptors, but we don't yet know how these processes occur, we don't know where chaperoning occurs in the cell (e.g. Is it limited to the cytoplasm? Is it a diffuse process or does chaperoning occur in association with structural elements?), and, with the exception of the requirement for hormone binding, we don't know the extent to which the hsp90-based chaperone system impacts on steroid hormone action. It is not yet clear how far the discovery of this hsp90 heterocomplex assembly system will be extended to the development of a general understanding of protein processing in the cell. Because this assembly system is apparently present in all eukaryotic cells, it probably performs an essential function for many proteins. The bacterial homolog of hsp90 is not an essential protein, but hsp90 is essential in eukaryotes, and recent studies indicate that the development of the cell nucleus from prokaryotic progenitors was accompanied by the duplication of genes for hsp90 and hsp70 (698). (ABSTRACT TRUNCATED) | Steroid receptor interactions with heat shock protein and immunophilin chaperones. |
30208015 | Oxysterols are oxygenated cholesterol derivates that are emerging as a physiologically important group of molecules. Although they regulate a range of cellular processes, only few oxysterol-binding effector proteins have been identified, and the knowledge of their binding mode is limited. Recently, the family of G protein-coupled seven transmembrane-spanning receptors (7TM receptors) was added to this group. Specifically, the Epstein-Barr virus-induced gene 2 (EBI2 or GPR183) was shown to be activated by several oxysterols, most potently by 7α,25-dihydroxycholesterol (7α,25-OHC). Nothing is known about the binding mode, however. Using mutational analysis, we identify here four key residues for 7α,25-OHC binding: Arg-87 in TM-II (position II:20/2.60), Tyr-112 and Tyr-116 (positions III:09/3.33 and III:13/3.37) in TM-III, and Tyr-260 in TM-VI (position VI:16/6.51). Substituting these residues with Ala and/or Phe results in a severe decrease in agonist binding and receptor activation. Docking simulations suggest that Tyr-116 interacts with the 3β-OH group in the agonist, Tyr-260 with the 7α-OH group, and Arg-87, either directly or indirectly, with the 25-OH group, although nearby residues likely also contribute. In addition, Tyr-112 is involved in 7α,25-OHC binding but via hydrophobic interactions. Finally, we show that II:20/2.60 constitutes an important residue for ligand binding in receptors carrying a positively charged residue at this position. This group is dominated by lipid- and nucleotide-activated receptors, here exemplified by the CysLTs, P2Y12, and P2Y14. In conclusion, we present the first molecular characterization of oxysterol binding to a 7TM receptor and identify position II:20/2.60 as a generally important residue for ligand binding in certain 7TM receptors. | Molecular Characterization of Oxysterol Binding to the Epstein-Barr Virus-induced Gene 2 (GPR183)* |
30221601 | The delineation of dopamine dysfunction in the mentally ill has been a long-standing quest of biological psychiatry. The present study focuses on a recently recognized group of dopamine receptor-interacting proteins as possible novel sites of dysfunction in schizophrenic and bipolar patients. We demonstrate that the dorsolateral prefrontal cortex in schizophrenia and bipolar cases from the Stanley Foundation Neuropathology Consortium display significantly elevated levels of the D2 dopamine receptor desensitization regulatory protein, neuronal calcium sensor-1. These levels of neuronal calcium sensor-1 were not influenced by age, gender, hemisphere, cause of death, postmortem period, alcohol consumption, or antipsychotic and mood stabilizing medications. The present study supports the hypothesis that schizophrenia and bipolar disorder may be associated with abnormalities in dopamine receptor-interacting proteins. | Up-regulation of neuronal calcium sensor-1 (NCS-1) in the prefrontal cortex of schizophrenic and bipolar patients. |
30224907 | The c-Abl tyrosine kinase and its transforming variants have been implicated in tumorigenesis and in many important cellular processes. c-Abl is localized in the nucleus and the cytoplasm, where it plays distinct roles. The effects of c-Abl are mediated by multiple protein-protein and protein-DNA interactions and its tyrosine kinase domain. At the biochemical level, the mechanism of c-Abl kinase activation and the identification of its target proteins and cellular machineries have in part been solved. However, the phenotypic outcomes of these molecular events remained in large elusive. c-Abl has been shown to regulate the cell cycle and to induce under certain conditions cell growth arrest and apoptosis. In this respect the interaction of c-Abl with p53 and p73 has attracted particular attention. Recent findings have implicated c-Abl in an ionizing irradiation signaling pathway that elicits apoptosis. In this pathway p73 is an important immediate downstream effector. Here I review the current knowledge about these nuclear processes in which c-Abl is engaged and discuss some of their possible implications on cell physiology. | c-Abl: activation and nuclear targets |
30226988 | The EUROCARE project analysed cancer survival data from 45 population-based cancer registries in 17 European countries, revealing wide international differences in cancer survival. We calculated 5-year relative survival for 1836287 patients diagnosed with one of 13 cancers during the period 1978-1989. The data, from 20 cancer registries in 13 countries, were grouped into four regions: Finland, Sweden, Iceland (Northern Europe); Denmark, England and Scotland (UK and Denmark); France, The Netherlands, Germany, Italy and Switzerland (Western Europe); Estonia and Poland (Eastern Europe), and broken down into four periods (1978-1980, 1981-1983, 1984-1986, 1987-1989). For each cancer, mean European and regional survival was estimated as the weighted mean of 5-year relative survival in each country. Survival increased with time for all tumours, particularly for cancers of testis (12% increase, i.e. from 79.9 to 91.9%), breast, large bowel, skin melanoma (approximately 9-10%), and lymphomas (approximately 7%). For most solid tumours, survival was highest in Northern Europe and lowest in Eastern Europe, and also low in the UK and Denmark. Regional variation was less marked for the lymphomas. Survival improved more in Western than Northern Europe, and the differences between these regions fell for bowel cancer (from 8.0% for those diagnosed in 1978-1980 to 2% for those diagnosed in 1987-1989), breast cancer (from 7.4% to 3.9%), skin melanoma (from 13.4% to 11.0%) and Hodgkin's disease (from 7.2 to 0.6%). For potentially curable malignancies such as Hodgkin's disease, large bowel, breast and testicular cancers, there were substantial increases in survival, suggesting an earlier diagnosis and more effective treatment. The persisting regional differences suggest there are corresponding differences in the availability of diagnostic and therapeutic facilities, and in the effectiveness of healthcare systems. | Cancer survival increases in Europe, but international differences remain wide. |
30261663 | In eukaryotes, a surveillance mechanism known as nonsense-mediated decay (NMD) degrades the mRNA when a premature-termination codon (PTC) is present. NMD requires translation to read the frame of the mRNA and detect the PTC. During pre-mRNA splicing, the exon-exon junction complex (EJC) is recruited to a region 20-24 nt upstream of the exon junction on the mature mRNA. The presence of a PTC upstream from the EJC elicits NMD. Eukaryotic initiation factor 4A (eIF4A) III is a nuclear protein that interacts physically or functionally with translation initiation factors eIF4G and eIF4B, respectively, and shares strikingly high identity with the initiation factors eIF4AI/II. Here we show that siRNA against eIF4AIII, but not against eIF4AI/II, inhibits NMD. Moreover, eIF4AIII, but not eIF4AI, is specifically recruited to the EJC during splicing. The observations that eIF4AIII is loaded onto the mRNA during splicing in the nucleus, has properties related to a translation initiation factor, and functions in NMD raises the possibility that eIF4AIII substitutes for eIF4AI/II during NMD. | A nuclear translation-like factor eIF4AIII is recruited to the mRNA during splicing and functions in nonsense-mediated decay. |
30292811 | Swaddling was an almost universal child-care practice before the 18th century. It is still tradition in certain parts of the Middle East and is gaining popularity in the United Kingdom, the United States, and The Netherlands to curb excessive crying. We have systematically reviewed all articles on swaddling to evaluate its possible benefits and disadvantages. In general, swaddled infants arouse less and sleep longer. Preterm infants have shown improved neuromuscular development, less physiologic distress, better motor organization, and more self-regulatory ability when they are swaddled. When compared with massage, excessively crying infants cried less when swaddled, and swaddling can soothe pain in infants. It is supportive in cases of neonatal abstinence syndrome and infants with neonatal cerebral lesions. It can be helpful in regulating temperature but can also cause hyperthermia when misapplied. Another possible adverse effect is an increased risk of the development of hip dysplasia, which is related to swaddling with the legs in extension and adduction. Although swaddling promotes the favorable supine position, the combination of swaddling with prone position increases the risk of sudden infant death syndrome, which makes it necessary to warn parents to stop swaddling if infants attempt to turn. There is some evidence that there is a higher risk of respiratory infections related to the tightness of swaddling. Furthermore, swaddling does not influence rickets onset or bone properties. Swaddling immediately after birth can cause delayed postnatal weight gain under certain conditions, but does not seem to influence breastfeeding parameters. | Swaddling: a systematic review. |
30297355 | The Norrie disease gene (Ndp) codes for a secreted protein, Norrin, that activates canonical Wnt signaling by binding to its receptor, Frizzled-4. This signaling system is required for normal vascular development in the retina and for vascular survival in the cochlea. In mammals, the pattern of Ndp expression beyond the retina is poorly defined due to the low abundance of Norrin mRNA and protein. Here, we characterize Ndp expression during mouse development by studying a knock-in mouse that carries the coding sequence of human placental alkaline phosphatase (AP) inserted at the Ndp locus (Ndp(AP)). In the CNS, Ndp(AP) expression is apparent by E10.5 and is dynamic and complex. The anatomically delimited regions of Ndp(AP) expression observed prenatally in the CNS are replaced postnatally by widespread expression in astrocytes in the forebrain and midbrain, Bergman glia in the cerebellum, and Müller glia in the retina. In the developing and adult cochlea, Ndp(AP) expression is closely associated with two densely vascularized regions, the stria vascularis and a capillary plexus between the organ of Corti and the spiral ganglion. These observations suggest the possibility that Norrin may have developmental and/or homeostatic functions beyond the retina and cochlea. | Expression of the Norrie disease gene (Ndp) in developing and adult mouse eye, ear, and brain. |
30303335 | Excitation-transcription coupling, linking stimulation at the cell surface to changes in nuclear gene expression, is conserved throughout eukaryotes. How closely related coexpressed transcription factors are differentially activated remains unclear. Here, we show that two Ca2+-dependent transcription factor isoforms, NFAT1 and NFAT4, require distinct sub-cellular InsP3 and Ca2+ signals for physiologically sustained activation. NFAT1 is stimulated by sub-plasmalemmal Ca2+ microdomains, whereas NFAT4 additionally requires Ca2+ mobilization from the inner nuclear envelope by nuclear InsP3 receptors. NFAT1 is rephosphorylated (deactivated) more slowly than NFAT4 in both cytoplasm and nucleus, enabling a more prolonged activation phase. Oscillations in cytoplasmic Ca2+, long considered the physiological form of Ca2+ signaling, play no role in activating either NFAT protein. Instead, effective sustained physiological activation of NFAT4 is tightly linked to oscillations in nuclear Ca2+. Our results show how gene expression can be controlled by coincident yet geographically distinct Ca2+ signals, generated by a freely diffusible InsP3 message. | Control of NFAT Isoform Activation and NFAT-Dependent Gene Expression through Two Coincident and Spatially Segregated Intracellular Ca2+ Signals |
30351165 | Cerebral apolipoprotein E (apoE) has been implicated in neuronal protection and repair. Due to the variable levels and types of estrogen receptors within different brain regions, the effect of estrogen on apoE and the mechanism of this effect may vary within different regions. Ovariectomized female C57BL/6 mice were treated with pharmacological levels of 17 beta-estradiol or placebo for 5 days, resulting in supraphysiological plasma levels of estradiol in the treated mice. ApoE and glial fibrillary acidic protein (GFAP) levels were measured in the cortex, hippocampus and diencephalon. 17 beta-Estradiol up-regulated apoE but not GFAP in the cortex and diencephalon, whereas in the hippocampus, GFAP and apoE were equally up-regulated. Treatment of estrogen receptor (ER) alpha knockout mice with 17 beta-estradiol or treatment of C57BL/6 mice with 17 alpha-estradiol, a poor estrogen receptor agonist, specifically induced apoE in the cortex, but not in the diencephalon. These results indicate that 17 beta-estradiol effects on apoE are either directly or indirectly mediated by ER alpha in the diencephalon, while the effects in the cortex may be mediated by a non-classical mechanism or by ER beta. Measurement of mRNA levels in estrogen versus placebo-treated wild-type mice indicated that the effect of 17 beta-estradiol on apoE was not associated with changes in apoE mRNA levels. | Brain region-specific up-regulation of mouse apolipoprotein E by pharmacological estrogen treatments. |
30353437 | Ataxia telangiectasia (AT) has long intrigued the biomedical research community owing to the spectrum of defects that are characteristic of the disease, including neurodegeneration, immune dysfunction, radiosensitivity and cancer predisposition. Following the identification of mutations in ATM (ataxia telangiectasia, mutated) as the underlying cause of the disease, biochemical analysis of this protein kinase has shown that it is a crucial nexus for the cellular response to DNA double-stranded breaks. Many ATM kinase substrates are important players in the cellular responses that prevent cancer. Accordingly, AT is a disease that results from defects in the response to specific types of DNA damage. Thus, although it is a rare neurodegenerative disease, understanding the biology of AT will lead to a greater understanding of the fundamental processes that underpin cancer and neurodegeneration. | ATM and ataxia telangiectasia. |
30369606 | Obtaining primary human endometrial stromal cells (HESCs) for in vitro studies is limited by the scarcity of adequate human material and the inability to passage these cells in culture for long periods. Immortalization of these cells would greatly facilitate studies; however, the process of immortalization often results in abnormal karyotypes and aberrant functional characteristics. To meet this need, we have introduced telomerase into cultured HESCs to prevent the normal shortening of telomeres observed in adult somatic cells during mitosis. We have now developed and analyzed a newly immortalized HESC line that contains no clonal chromosomal structural or numerical abnormalities. In addition, when compared with the primary unpassaged parent cells, the new cell line displayed similar biochemical endpoints after treatment with ovarian steroids. Classical decidualization response to estradiol plus medroxyprogesterone acetate were seen in both morphologically, and progestin was seen to induce or regulate the expression of IGF binding protein-1, fibronectin, prolactin, tissue factor, plasminogen activator inhibitor-1, and Fas/Fas ligand. In summary, an immortalized HESC line has been developed that is karyotypically, morphologically, and phenotypically similar to the primary parent cells, and it is a powerful and consistent resource for in vitro work. | A novel immortalized human endometrial stromal cell line with normal progestational response. |
30379039 | We studied the intrinsic tyrosine kinase activity and substrate specificity of c-Abl and Bcr-Abl protein tyrosine kinases (PTKs) using the peptide substrates discovered from a synthetic combinatorial peptide library. Our data indicate that the phosphorylation of these peptides by Bcr-Abl was consistently stronger than that by c-Abl. Bcr-Abl also showed substrate preference towards those peptides with one or more positive charges. | Comparison of the intrinsic kinase activity and substrate specificity of c-Abl and Bcr-Abl. |
30398773 | Alloimmune lung syndromes (allo-LS), including idiopathic pneumonia syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans organizing pneumonia, are severe complications after hematopoietic stem cell transplantation (HSCT). In our cohort of 110 pediatric patients, 30 had allo-LS (27.3%), 18 with idiopathic pneumonia syndrome and 12 with bronchiolitis obliterans syndrome. Multivariate analysis showed that respiratory viral infection early after HSCT is an important predictor for the development of allo-LS (P <.0001). This was true for all viruses tested. In multivariate analysis, allo-LS was the only predictor for higher mortality (P = .04). Paradoxically, prolonged administration of immunosuppressive agents because of acute graft-versus-host disease had a protective effect on the development of allo-LS (P = .004). We hypothesize that early infection of the respiratory tract with a common cold virus makes the lungs a target for alloimmunity. | Strong association between respiratory viral infection early after hematopoietic stem cell transplantation and the development of life-threatening acute and chronic alloimmune lung syndromes. |
30437264 | Hepatitis C virus (HCV) is a single-stranded RNA virus encoding a single polyprotein whose translation is driven by an internal ribosome entry site (IRES). HCV infection strongly induces antiviral interferon-stimulated gene (ISG) expression in the liver, yet it persists, suggesting that HCV can block ISG effector function. We now show that HCV infection triggers phosphorylation and activation of the RNA-dependent protein kinase PKR, which inhibits eukaryotic translation initiation factor eIF2 alpha and attenuates ISG protein expression despite normal ISG mRNA induction. ISG protein induction is restored and the antiviral effects of interferon are enhanced when PKR expression is suppressed in interferon-treated infected cells. Whereas host protein translation, including antiviral ISGs, is suppressed by activated PKR, HCV IRES-dependent translation is not. These results suggest that the ability of HCV to activate PKR may, paradoxically, be advantageous for the virus during an IFN response by preferentially suppressing the translation of ISGs. | Hepatitis C virus blocks interferon effector function by inducing protein kinase R phosphorylation. |
30464859 | The aim of the present research is to ascertain whether in larval Xenopus laevis nerve-independence for the regeneration of early stage limbs and nerve-dependence of late stage limbs observed in a previous work (Filoni and Paglialunga, '90) is related to extrinsic (systemic) factors or to intrinsic changes taking place in the limb cells themselves during development. In this paper the regenerative capacity of early and late stage hindlimbs under the same extrinsic conditions, insofar as both are grafted onto the denervated hindlimbs of host larvae at the same developmental stage, is studied. All the grafted limbs are amputated after the host larvae have reached stage 57-58 (according to Nieuwkoop and Faber, '56). In experiment I, the grafted limb is amputated at stage 52, at the thigh level; in experiment II, the grafted limb is amputated at stage 54-55, at the tarsalia level; in experiment III the grafted limb is amputated at stage 57, at the tarsalia level. In all three experiments, together with the grafted limb, also the host limb is amputated at the tarsalia level. The results show that while grafted limbs amputated at stages 52 and 54-55 regenerate in the absence of nerves, grafted limbs amputated at stage 57 cannot. The failure of late stage grafted limbs to regenerate cannot be explained in terms of an immune-type inhibiting reaction since it has been observed also in denervated autografted limbs and in the host limbs. Since all the grafted limbs are in the same environmental conditions, the results show that in larval Xenopus laevis nerve-independence for regeneration of early stage limbs and nerve-dependence of late stage limbs are not related to factors extrinsic to the limb but to intrinsic changes taking place in the limb cells themselves during development. | The influence of denervation on grafted hindlimb regeneration of larval Xenopus laevis. |
30468386 | The olfactory epithelium houses chemosensory neurons, which transmit odor information from the nose to the brain. In adult mammals, the olfactory epithelium is a uniquely robust neuroproliferative zone, with the ability to replenish its neuronal and non-neuronal populations due to the presence of germinal basal cells. The stem and progenitor cells of these germinal layers, and their regulatory mechanisms, remain incompletely defined. Here we show that progenitor cells expressing c-Kit, a receptor tyrosine kinase marking stem cells in a variety of embryonic tissues, are required for maintenance of the adult neuroepithelium. Mouse genetic fate-mapping analyses show that embryonically, a c-Kit(+) population contributes to olfactory neurogenesis. In adults under conditions of normal turnover, there is relatively sparse c-Kit(+) progenitor cell (ckPC) activity. However, after experimentally induced neuroepithelial injury, ckPCs are activated such that they reconstitute the neuronal population. There are also occasional non-neuronal cells found to arise from ckPCs. Moreover, the selective depletion of the ckPC population, utilizing temporally controlled targeted diphtheria toxin A expression, results in failure of neurogenesis after experimental injury. Analysis of this model indicates that most ckPCs reside among the globose basal cell populations and act downstream of horizontal basal cells, which can serve as stem cells. Identification of the requirement for olfactory c-Kit-expressing progenitors in olfactory maintenance provides new insight into the mechanisms involved in adult olfactory neurogenesis. Additionally, we define an important and previously unrecognized site of adult c-Kit activity. | Adult c-Kit(+) progenitor cells are necessary for maintenance and regeneration of olfactory neurons. |
30471052 | The basic helix-loop-helix transcription factor neurogenin-3 (Ngn3, Neurog3) is critical for the development of the endocrine cells of the islets. Either disrupted or forced expression of Ngn3 early in mouse pancreas development abrogates the formation of islets. The successive waves of Ngn3 expression that occur during the primary and secondary transitions of endocrine cell development temporally determine the four distinct endocrine cell lineages, α, β, PP, and δ cells that express glucagon, insulin, pancreatic polypeptide, and somatostatin, respectively. During islet regeneration after injury of the adult mouse pancreas, such as by duct ligation or streptozotocin, Ngn3 is activated in duct-associated stem/progenitor cells that transform into alpha and/or beta cells (Xu et al, Collombat et al). The important role of Ngn3 as a master regulator of endocrine pancreas development directs attention to finding therapeutic approaches to enhance Ngn3 expression in diabetes as a means to increase beta cell mass and functions. | Neurogenin3: a master regulator of pancreatic islet differentiation and regeneration. |
30492966 | Amyotrophic Lateral Sclerosis (ALS) is a progressive degenerative disease of the motor neurons and the cause is unknown. Diverse factors such as genetic defects, nutritional deficiencies, head trauma, environmental toxin, autoimmune responses and viral and bacterial infections are involved. Mycoplasmas have been implicated as causal agents of different illnesses in human. The purpose of this study was to investigate the presence of mycoplasmas in the bloodstream of patients with ALS. Patients with ALS and healthy individuals were included in the study. A blood sample was taken in tubes with or without anticoagulant. Mycoplasmas were detected by culture or direct PCR, and the presence of antibodies IgM and IgG against LAMPs of these microorganisms by Western blot. Cultures for aerobic facultative bacteria were also done. Blood samples from 13 patients and 44 healthy individuals were screened. All blood cultures for non-fermentative mycoplasmas and aerobic facultative bacteria were negative. Cultures for fermentative mycoplasmas were considered positive after identification of mycoplasmal DNA by PCR. Mycoplasma sp. was detected by culture or direct PCR in 6/13 (46%) patients and in 4/44 (9%) of healthy individuals. M. fermentans was detected by PCR using specific primers in six patients and in two healthy individuals. IgM against LAMPs of M. fermentans were detected in 6/13 (46%) blood samples from patients and in 13/44 (30%) from healthy individuals, while. IgG was detected in 4/13 (31%) patients and in 3/44 (7%) healthy individuals. The results of this study show that mycoplasmas cause a systemic infection and could play a role in the origin or progression of the ALS. | Detection of Mycoplasmas in Patients with Amyotrophic Lateral Sclerosis |
30500829 | This paper is about variable selection with the random forests algorithm in presence of correlated predictors. In high-dimensional regression or classification frameworks, variable selection is a difficult task, that becomes even more challenging in the presence of highly correlated predictors. Firstly we provide a theoretical study of the permutation importance measure for an additive regression model. This allows us to describe how the correlation between predictors impacts the permutation importance. Our results motivate the use of the Recursive Feature Elimination (RFE) algorithm for variable selection in this context. This algorithm recursively eliminates the variables using permutation importance measure as a ranking criterion. Next various simulation experiments illustrate the efficiency of the RFE algorithm for selecting a small number of variables together with a good prediction error. Finally, this selection algorithm is tested on the Landsat Satellite data from the UCI Machine Learning Repository. | Correlation and variable importance in random forests |
30507607 | Transcription factors, such as Oct4, are critical for establishing and maintaining pluripotent cell identity. Whereas the genomic locations of several pluripotency transcription factors have been reported, the spectrum of their interaction partners is underexplored. Here, we use an improved affinity protocol to purify Oct4-interacting proteins from mouse embryonic stem cells (ESCs). Subsequent purification of Oct4 partners Sall4, Tcfcp2l1, Dax1, and Esrrb resulted in an Oct4 interactome of 166 proteins, including transcription factors and chromatin-modifying complexes with documented roles in self-renewal, but also many factors not previously associated with the ESC network. We find that Esrrb associated with the basal transcription machinery and also detect interactions between transcription factors and components of the TGF-beta, Notch, and Wnt signaling pathways. Acute depletion of Oct4 reduced binding of Tcfcp2l1, Dax1, and Esrrb to several target genes. In conclusion, our purification protocol allowed us to bring greater definition to the circuitry controlling pluripotent cell identity. | An Oct4-Centered Protein Interaction Network in Embryonic Stem Cells |
30534237 | BACKGROUND Dysfunction of gamma-aminobutyric acid (GABA) (B) receptors has been implicated in the pathogenesis of temporal lobe epilepsy (TLE).
OBJECTIVE To evaluate the genetic contribution of cloned human GABA(B) receptors to TLE.
METHODS The authors genotyped 141 patients (78 women and 63 men; mean age = 49.1 +/- 18.0 years) with nonlesional TLE and 372 age- and sex-matched normal individuals for the known polymorphism G1465A in the human GABA(B) receptor 1 [GABA(B[1])] gene.
RESULTS There was a highly significant overrepresentation of the G1465A heterozygote in patients with TLE compared with controls. The A/G genotype was found in 17% of the 141 patients with TLE and in only 0.5% of the 372 controls (p < 0.0001). The authors also found that patients carrying the A allele had a significantly higher risk (p = 0.003, OR = 6.47, 95% CI = 2.02 to 20.76) of developing drug-resistant TLE. Furthermore, the age at onset of seizures tended to be lower in patients with A/G genotype, but the difference was not significant.
CONCLUSIONS The results of this study indicate that the GABA(B[1]) polymorphism (G1465A) confers a highly increased susceptibility to TLE. Moreover, it seems to influence the severity of this common epileptic disorder. | GABA(B) receptor 1 polymorphism (G1465A) is associated with temporal lobe epilepsy. |
30543439 | Deregulated redox metabolism in cancer leads to oxidative damage to cellular components including deoxyribonucleoside triphosphates (dNTPs). Targeting dNTP pool sanitizing enzymes, such as MTH1, is a highly promising anticancer strategy. The MTH2 protein, known as NUDT15, is described as the second human homologue of bacterial MutT with 8-oxo-dGTPase activity. We present the first NUDT15 crystal structure and demonstrate that NUDT15 prefers other nucleotide substrates over 8-oxo-dGTP. Key structural features are identified that explain different substrate preferences for NUDT15 and MTH1. We find that depletion of NUDT15 has no effect on incorporation of 8-oxo-dGTP into DNA and does not impact cancer cell survival in cell lines tested. NUDT17 and NUDT18 were also profiled and found to have far less activity than MTH1 against oxidized nucleotides. We show that NUDT15 is not a biologically relevant 8-oxo-dGTPase, and that MTH1 is the most prominent sanitizer of the cellular dNTP pool known to date. | Crystal structure, biochemical and cellular activities demonstrate separate functions of MTH1 and MTH2 |
30553457 | The role of transient receptor potential M4 (Trpm4), an unusual member of the Trp family of ion channels, is poorly understood. Using rodent models of spinal cord injury, we studied involvement of Trpm4 in the progressive expansion of secondary hemorrhage associated with capillary fragmentation, the most destructive mechanism of secondary injury in the central nervous system. Trpm4 mRNA and protein were abundantly upregulated in capillaries preceding their fragmentation and formation of petechial hemorrhages. Trpm4 expression in vitro rendered COS-7 cells highly susceptible to oncotic swelling and oncotic death following ATP depletion. After spinal cord injury, in vivo gene suppression in rats treated with Trpm4 antisense or in Trpm4−/− mice preserved capillary structural integrity, eliminated secondary hemorrhage, yielded a threefold to fivefold reduction in lesion volume and produced a substantial improvement in neurological function. To our knowledge, this is the first example of a Trp channel that must undergo de novo expression for manifestation of central nervous system pathology. | De novo expression of Trpm4 initiates secondary hemorrhage in spinal cord injury |
30580263 | The cell-positional incidence of both spontaneous and damage-induced apoptosis of epithelial cells was assessed in longitudinal sections of the crypts of small intestine and colon of BDF1 mice. This was compared, using immunohistochemistry, with the pattern of expression of bcl-2, a suppressor of apoptosis. In the small intestine, apoptosis was maximal around cell position 4 from the base of the crypt; this closely corresponds to the position considered to contain the stem cells. In the colon, however, apoptosis was not confined to the area considered to harbour the stem cells (position 1 and 2). Instead, apoptosis was attenuated and distributed along the length of the crypt. Some cells at the base of murine colonic crypts expressed bcl-2 protein, whereas bcl-2 was absent in the crypts of the small intestine. Most pertinently, bcl-2 was absent from small intestinal crypt cells at positions 4-5 (the stem cell region). The importance of the expression of bcl-2 to the attenuation of apoptosis in stem cells was confirmed by analysis of the levels of both spontaneous and induced apoptosis in homozygously bcl-2 null C57BL/6 mice: in colonic crypts the level of spontaneous apoptosis rose significantly, and selectively at the base of the crypt, in comparison with crypts from wild-type animals. In contrast, there was no rise in spontaneous apoptosis in the small intestinal crypts from the bcl-2 null animals. Analysis of sections of human colon and small intestine also showed that expression of bcl-2 was confined to the base of the colonic crypt. The attenuation of apoptosis by bcl-2 in the region of the stem cells of the colonic crypts may dispose these to neoplastic transformation. Indeed, analysis of human carcinomas revealed expression of bcl-2, which in some samples was reciprocal with the expression of p53. | Differential expression of bcl-2 in intestinal epithelia. Correlation with attenuation of apoptosis in colonic crypts and the incidence of colonic neoplasia. |
30639847 | CONTEXT Vascular stiffness increases with advancing age and is a major risk factor for age-related morbidity and mortality. Vascular stiffness and blood pressure pulsatility are related; however, temporal relationships between vascular stiffening and blood pressure elevation have not been fully delineated.
OBJECTIVE To examine temporal relationships among vascular stiffness, central hemodynamics, microvascular function, and blood pressure progression.
DESIGN, SETTING, AND PARTICIPANTS Longitudinal community-based cohort study conducted in Framingham, Massachusetts. The present investigation is based on the 2 latest examination cycles (cycle 7: 1998-2001; cycle 8: 2005-2008 [last visit: January 25, 2008]) of the Framingham Offspring study (recruited: 1971-1975). Temporal relationships among blood pressure and 3 measures of vascular stiffness and pressure pulsatility derived from arterial tonometry (carotid-femoral pulse wave velocity [CFPWV], forward wave amplitude [FWA], and augmentation index) were examined over a 7-year period in 1759 participants (mean [SD] age: 60 [9] years; 974 women).
MAIN OUTCOME MEASURES The primary outcomes were blood pressure and incident hypertension during examination cycle 8. The secondary outcomes were CFPWV, FWA, and augmentation index during examination cycle 8.
RESULTS In a multivariable-adjusted regression model, higher FWA (β, 1.3 [95% CI, 0.5-2.1] mm Hg per 1 SD; P = .002) and higher CFPWV (β, 1.5 [95% CI, 0.5-2.6] mm Hg per 1 SD; P = .006) during examination cycle 7 were jointly associated with systolic blood pressure during examination cycle 8. Similarly, in a model that included systolic and diastolic blood pressure and additional risk factors during examination cycle 7, higher FWA (odds ratio [OR], 1.6 [95% CI, 1.3-2.0] per 1 SD; P < .001), augmentation index (OR, 1.7 [95% CI, 1.4-2.0] per 1 SD; P < .001), and CFPWV (OR, 1.3 [95% CI, 1.0-1.6] per 1 SD; P = .04) were associated with incident hypertension during examination cycle 8 (338 cases [32%] in 1048 participants without hypertension during examination cycle 7). Conversely, blood pressure during examination cycle 7 was not associated with CFPWV during examination cycle 8. Higher resting brachial artery flow (OR, 1.23 [95% CI, 1.04-1.46]) and lower flow-mediated dilation (OR, 0.80 [95% CI, 0.67-0.96]) during examination cycle 7 were associated with incident hypertension (in models that included blood pressure and tonometry measures collected during examination cycle 7).
CONCLUSION In this cohort, higher aortic stiffness, FWA, and augmentation index were associated with higher risk of incident hypertension; however, initial blood pressure was not independently associated with risk of progressive aortic stiffening. | Aortic stiffness, blood pressure progression, and incident hypertension. |
30655442 | The EMBL Nucleotide Sequence Database (http://www.ebi.ac.uk/embl. html ) constitutes Europe's primary nucleotide sequence resource. DNA and RNA sequences are directly submitted from researchers and genome sequencing groups and collected from the scientific literature and patent applications (Fig. 1). In collaboration with DDBJ and GenBank the database is produced, maintained and distributed at the European Bioinformatics Institute. Database releases are produced quarterly and are distributed on CD-ROM. EBI's network services allow access to the most up-to-date data collection via Internet and World Wide Web interface, providing database searching and sequence similarity facilities plus access to a large number of additional databases. | The EMBL nucleotide sequence database. |
30658796 | Neoplastic cells are genetically unstable. Strategies that target pathways affecting genome instability can be exploited to disrupt tumor cell growth, potentially with limited consequences to normal cells. Chromosomal instability (CIN) is one type of genome instability characterized by mitotic defects that increase the rate of chromosome mis-segregation. CIN is frequently caused by extra centrosomes that transiently disrupt normal bipolar spindle geometry needed for accurate chromosome segregation. Tumor cells survive with extra centrosomes because of biochemical pathways that cluster centrosomes and promote chromosome segregation on bipolar spindles. Recent work shows that targeted inhibition of these pathways prevents centrosome clustering and forces chromosomes to segregate to multiple daughter cells, an event triggering apoptosis that we refer to as anaphase catastrophe. Anaphase catastrophe specifically kills tumor cells with more than 2 centrosomes. This death program can occur after genetic or pharmacologic inhibition of cyclin dependent kinase 2 (Cdk2) and is augmented by combined treatment with a microtubule inhibitor. This proapoptotic effect occurs despite the presence of ras mutations in cancer cells. Anaphase catastrophe is a previously unrecognized mechanism that can be pharmacologically induced for apoptotic death of cancer cells and is, therefore, appealing to engage for cancer therapy and prevention. | Anaphase catastrophe is a target for cancer therapy. |
30675656 | Frizzled family proteins have been described as receptors of Wnt signaling molecules. In Drosophila, the two known Frizzled proteins are associated with distinct developmental processes. Genesis of epithelial planar polarity requires Frizzled, whereas Dfz2 affects morphogenesis by wingless-mediated signaling. Dishevelled is required in both signaling pathways. Here, we use genetic and overexpression assays to show that Dishevelled activates JNK cascades. Rescue analysis reveals different protein domain requirements in Dishevelled for the two pathways; the C-terminal DEP domain is essential to rescue planar polarity defects and induce JNK signaling. Furthermore, the planar polarity-specific dsh1 allele is mutated in the DEP domain. Our results indicate that different Wnt/Fz signals activate distinct intracellular pathways, and Dishevelled discriminates among them by distinct domain interactions. | Dishevelled Activates JNK and Discriminates between JNK Pathways in Planar Polarity and wingless Signaling |
30714190 | The mechanisms regulating lineage potential during early hematopoiesis were investigated. First, a cascade of lineage-affiliated gene expression signatures, primed in hematopoietic stem cells (HSCs) and differentially propagated in lineage-restricted progenitors, was identified. Lymphoid transcripts were primed as early as the HSC, together with myeloid and erythroid transcripts. Although this multilineage priming was resolved upon subsequent lineage restrictions, an unexpected cosegregation of lymphoid and myeloid gene expression and potential past a nominal myeloid restriction point was identified. Finally, we demonstrated that whereas the zinc finger DNA-binding factor Ikaros was required for induction of lymphoid lineage priming in the HSC, it was also necessary for repression of genetic programs compatible with self-renewal and multipotency downstream of the HSC. Taken together, our studies provide new insight into the priming and restriction of lineage potentials during early hematopoiesis and identify Ikaros as a key bivalent regulator of this process. | Genome-wide lineage-specific transcriptional networks underscore Ikaros-dependent lymphoid priming in hematopoietic stem cells. |
30720103 | Vitamin D, the sunshine vitamin, is now recognized not only for its importance in promoting bone health in children and adults but also for other health benefits, including reducing the risk of chronic diseases such as autoimmune diseases, common cancer, and cardiovascular disease. Vitamin D made in the skin or ingested in the diet is biologically inert and requires 2 successive hydroxylations first in the liver on carbon 25 to form 25-hydroxyvitamin D [25(OH)D], and then in the kidney for a hydroxylation on carbon 1 to form the biologically active form of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. With the identification of 25(OH)D and 1,25(OH)(2)D, methods were developed to measure these metabolites in the circulation. Serum 25(OH)D is the barometer for vitamin D status. Serum 1,25(OH)(2)D provides no information about vitamin D status and is often normal or even increased as the result of secondary hyperparathyroidism associated with vitamin D deficiency. Most experts agree that 25(OH)D of <20 ng/mL is considered to be vitamin D deficiency, whereas a 25(OH)D of 21-29 ng/mL is considered to be insufficient. The goal should be to maintain both children and adults at a level >30 ng/mL to take full advantage of all the health benefits that vitamin D provides. | Vitamin D status: measurement, interpretation, and clinical application. |
30741007 | The distribution of insecticide-treated bednets to help combat the burden of malaria in sub-Saharan Africa has accelerated in the past 5 years. Additionally, many countries are also considering, or have already begun, indoor residual spraying campaigns. These are positive developments, since vector control has repeatedly proven to be an effective means of reducing malaria transmission. However, the sustainability of these insecticide-based interventions relies on the continuing susceptibility of the anopheles vectors to the limited number of available insecticides. Continual monitoring for early signs of insecticide resistance and the adoption of carefully considered resistance management strategies are therefore required. Regrettably, this essential monitoring component is frequently given a low priority in the push to meet ambitious coverage targets. We outline the key requirements for establishing an insecticide resistance surveillance system and urge all those involved in malaria vector control, either directly or as facilitators, to ensure that these measures are incorporated into control programmes. Failure to act now will inevitably lead to a future breakdown in disease control and jeopardise hopes of eradicating this major public-health problem. | Lessons from the past: managing insecticide resistance in malaria control and eradication programmes. |
30774694 | Autophagy is a recently recognized immune effector mechanism against intracellular pathogens. The role of autophagy in innate immunity has been well established, but the extent of its regulation by the adaptive immune response is less well understood. The T helper 1 (Th1) cell cytokine IFN-gamma induces autophagy in macrophages to eliminate Mycobacterium tuberculosis. Here, we report that Th2 cytokines affect autophagy in macrophages and their ability to control intracellular M. tuberculosis. IL-4 and IL-13 abrogated autophagy and autophagy-mediated killing of intracellular mycobacteria in murine and human macrophages. Inhibition of starvation-induced autophagy by IL-4 and IL-13 was dependent on Akt signaling, whereas the inhibition of IFN-gamma-induced autophagy was Akt independent and signal transducer and activator of transcription 6 (STAT6) dependent. These findings establish a mechanism through which Th1-Th2 polarization differentially affects the immune control of intracellular pathogens. | T helper 2 cytokines inhibit autophagic control of intracellular Mycobacterium tuberculosis. |
30786800 | BACKGROUND The International Lipid-Based Nutrient Supplements Project developed a small-quantity (20 g/d) lipid-based nutrient supplement (LNS) for pregnant and lactating women.
OBJECTIVE We evaluated the effects of prenatal LNS supplementation on fetal growth.
DESIGN In a community-based, partially double-blind, individually randomized controlled trial, 1320 women ≤20 wk pregnant received 60 mg Fe/400 μg folic acid (IFA), or 1-2 Recommended Dietary Allowances of 18 micronutrients, including 20 mg Fe (MMN), or LNS with the same micronutrients as the MMN group, plus 4 minerals and macronutrients contributing 118 kcal (LNS) daily until delivery. Fetal growth was compared across groups by using intention-to-treat analysis. The primary outcome was birth length.
RESULTS This analysis included 1057 women (IFA = 349, MMN = 354, LNS = 354). Groups did not differ significantly in mean birth length, length-for-age z score (LAZ), head circumference, or percentage low birth length but differed in mean birth weight (P = 0.044), weight-for-age z score (WAZ; P = 0.046), and BMI-for-age z score (BMIZ; P = 0.040), with a trend toward differences in low birth weight (P = 0.069). In pairwise comparisons, the LNS group had greater mean birth weight (+85 g; P = 0.040), WAZ (+0.19; P = 0.045), and BMIZ (+0.21; P = 0.035) and a lower risk of low birth weight (RR: 0.61, 95% CI: 0.39, 0.96; P = 0.032) than did the IFA group. The other group differences were not significant. The effect of intervention was modified by mother's parity, age, height, baseline hemoglobin, household food insecurity, and child sex, with parity being the most consistent modifier. Among primiparous women (IFA = 131; MMN = 110; LNS = 128), the LNS group had greater mean birth length (+0.91 cm; P = 0.001), LAZ (+0.47; P = 0.001), weight (+237 g; P < 0.001), WAZ (+0.56; P < 0.001), BMIZ (+0.52; P < 0.001), head circumference (0.50 cm; P = 0.017), and head circumference-for-age z score (+0.40; P = 0.022) than did the IFA group; similar differences were found when comparing the LNS and MMN groups among primiparous women, and no group differences were found among multiparous women.
CONCLUSION Prenatal LNS supplementation can improve fetal growth among vulnerable women in Ghana, particularly primiparous women. This trial was registered at clinicaltrials.gov as NCT00970866. | Lipid-based nutrient supplement increases the birth size of infants of primiparous women in Ghana. |
30805636 | BACKGROUND Recent studies have shown that type 2 diabetes is preventable by both lifestyle interventions and medications that influence primary glucose metabolism. Whether pharmacological interventions that influence primary lipid metabolism can also delay development of type 2 diabetes is unknown. The goal of this study was to evaluate the effect of the peroxisome proliferator-activated receptor ligand bezafibrate on the progression of impaired fasting glucose phase to type 2 diabetes in patients with coronary artery disease over a 6.2-year follow-up period.
METHODS AND RESULTS The study sample comprised 303 nondiabetic patients 42 to 74 years of age with a fasting blood glucose level of 110 to 125 mg/dL (6.1 to 6.9 mmol/L). The patients received either 400 mg bezafibrate retard (156 patients) or placebo (147 patients) once a day. No patients were using statins, and use of ACE inhibitors, which also reduce diabetes incidence, was relatively low. During follow-up, development of new-onset diabetes was recorded in 146 patients: in 80 (54.4%) from the placebo group and 66 (42.3%) from the bezafibrate group (P=0.04). The mean time until onset of new diabetes was significantly delayed in patients on bezafibrate compared with patients on placebo: 4.6+/-2.3 versus 3.8+/-2.6 years (P=0.004). Multivariate analysis identified bezafibrate treatment as an independent predictor of reduced risk of new diabetes development (hazard ratio, 0.70; 95% CI, 0.49 to 0.99). Other significant variables associated with future overt type 2 diabetes in patients with impaired fasting glucose were total cholesterol level (hazard ratio, 1.22; 95% CI 1.0 to 1.51) and body mass index (hazard ratio, 1.10; 95% CI, 1.05 to 1.16).
CONCLUSIONS Bezafibrate reduces the incidence and delays the onset of type 2 diabetes in patients with impaired fasting glucose. Whether the combination of bezafibrate with other recommended drugs for secondary prevention (statins and ACE inhibitors) would be as efficacious as suggested by our results remains to be determined. | Peroxisome proliferator-activated receptor ligand bezafibrate for prevention of type 2 diabetes mellitus in patients with coronary artery disease. |
30813140 | Chronic tension-type headache (CTTH) assessed by proband report was evaluated in a family study of CTTH. A clinical interview of first-degree relatives by a physician was used as index of validity. Familial occurrence of CTTH in first-degree relatives was also investigated. Patterns of familial aggregation of CTTH were assessed by calculating the population relative risk. A neurological resident carried out all the interviews of probands and their first-degree relatives. The operational diagnostic criteria of the International Headache Society were used. The 122 probands had 377 first-degree relatives. Sensitivity, specificity, predictive values, and chance-corrected agreement rate for the diagnosis CTTH were 68%, 86%, 53% (PVpos), 92% (PVneg), and 0.48, respectively. The low sensitivity of CTTH assessed by proband report indicates that a clinical interview by a physician is necessary in family studies of CTTH. Clinically interviewed parents, siblings, and children had a 2.1 to 3.9-fold significantly increased risk of CTTH compared with the general population. The gender of the probands did not influence the risk of CTTH among first-degree relatives. The significantly increased familial risk of CTTH and no increased risk of CTTH in spouses suggest that a genetic factor is involved in CTTH. | Familial occurrence of chronic tension-type headache. |
30835854 | We have recently isolated SMAP (Smg GDS-associated protein; Smg GDS: small G protein GDP dissociation stimulator) as a novel Smg GDS-associated protein, which has Armadillo repeats and is phosphorylated by Src tyrosine kinase. SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. We isolated here a SMAP-interacting protein from a human brain cDNA library, identified it to be a human homolog of Xenopus XCAP-E (Xenopus chromosome-associated polypeptide), a subunit of condensins that regulate the assembly and structural maintenance of mitotic chromosomes, and named it HCAP (Human chromosome-associated polypeptide). Tissue and subcellular distribution analyses indicated that HCAP was ubiquitously expressed and highly concentrated in the nuclear fraction, where SMAP and KIF3B were also present. SMAP was extracted as a ternary complex with HCAP and KIF3B from the nuclear fraction in the presence of Mg-ATP. The results suggest that SMAP/KAP3 serves as a linker between HCAP and KIF3A/B in the nucleus, and that SMAP/KAP3 plays a role in the interaction of chromosomes with an ATPase motor protein. | Complex formation of SMAP/KAP3, a KIF3A/B ATPase motor-associated protein, with a human chromosome-associated polypeptide. |
30844602 | PROBLEM/CONDITION Since 1973, CDC has maintained a collaborative surveillance program for collection and periodic reporting of data on the occurrence and causes of foodborne-disease outbreaks (FBDOs) in the United States. REPORTING PERIOD COVERED This summary reviews data from January 1993 through December 1997. DESCRIPTION OF SYSTEM The Foodborne-Disease Outbreak Surveillance System reviews data concerning FBDOs, defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. State and local public health departments have primary responsibility for identifying and investigating FBDOs. State, local, and territorial health departments use a standard form to report these outbreaks to CDC.
RESULTS During 1993-1997, a total of 2,751 outbreaks of foodborne disease were reported (489 in 1993, 653 in 1994, 628 in 1995, 477 in 1996, and 504 in 1997). These outbreaks caused a reported 86,058 persons to become ill. Among outbreaks for which the etiology was determined, bacterial pathogens caused the largest percentage of outbreaks (75%) and the largest percentage of cases (86%). Salmonella serotype Enteritidis accounted for the largest number of outbreaks, cases, and deaths; most of these outbreaks were attributed to eating eggs. Chemical agents caused 17% of outbreaks and 1% of cases; viruses, 6% of outbreaks and 8% of cases; and parasites, 2% of outbreaks and 5% of cases.
INTERPRETATION The annual number of FBDOs reported to CDC did not change substantially during this period or from previous years. During this reporting period, S. Enteritidis continued to be a major cause of illness and death. In addition, multistate outbreaks caused by contaminated produce and outbreaks caused by Escherichia coli O157:H7 remained prominent. ACTIONS TAKEN Current methods to detect FBDOs are improving, and several changes to improve the ease and timeliness of reporting FBDO data are occurring (e.g., a revised form to simplify FBDO reporting by state health departments and electronic reporting methods). State and local health departments continue to investigate and report FBDOs as part of efforts to better understand and define the epidemiology of foodborne disease in the United States. At the regional and national levels, surveillance data provide an indication of the etiologic agents, vehicles of transmission, and contributing factors associated with FBDOs and help direct public health actions to reduce illness and death caused by FBDOs. | Surveillance for foodborne-disease outbreaks--United States, 1993-1997. |
30861948 | The ubiquitously expressed nonreceptor tyrosine kinase c-Abl contains three nuclear localization signals, however, it is found in both the nucleus and the cytoplasm of proliferating fibroblasts. A rapid and transient loss of c-Abl from the nucleus is observed upon the initial adhesion of fibroblasts onto a fibronectin matrix, suggesting the possibility of nuclear export [Lewis, J., Baskaran, R. , Taagepera, S., Schwartz, M. & Wang, J. (1996) Proc. Natl. Acad. Sci. USA 93, 15174-15179]. Here we show that the C terminus of c-Abl does indeed contain a functional nuclear export signal (NES) with the characteristic leucine-rich motif. The c-Abl NES can functionally complement an NES-defective HIV Rev protein (RevDelta3NI) and can mediate the nuclear export of glutathione-S-transferase. The c-Abl NES function is sensitive to the nuclear export inhibitor leptomycin B. Mutation of a single leucine (L1064A) in the c-Abl NES abrogates export function. The NES-mutated c-Abl, termed c-Abl NES(-), is localized exclusively to the nucleus. Treatment of cells with leptomycin B also leads to the nuclear accumulation of wild-type c-Abl protein. The c-Abl NES(-) is not lost from the nucleus when detached fibroblasts are replated onto fibronectin matrix. Taken together, these results demonstrate that c-Abl shuttles continuously between the nucleus and the cytoplasm and that the rate of nuclear import and export can be modulated by the adherence status of fibroblastic cells. | Nuclear-cytoplasmic shuttling of C-ABL tyrosine kinase. |
30884033 | Deciphering the molecular basis of stem cell pluripotency is fundamental to the understanding of stem cell biology, early embryonic development, and to the clinical application of regenerative medicine. We report here that the molecular chaperone heat shock protein 90 (Hsp90) is essential for mouse embryonic stem cell (ESC) pluripotency through regulating multiple pluripotency factors, including Oct4, Nanog, and signal transducer and activator of transcription 3. Inhibition of Hsp90 by either 17-N-Allylamino-17-demethoxygeldanamycin or miRNA led to ESC differentiation. Overexpression of Hsp90β partially rescued the phenotype; in particular, the levels of Oct4 and Nanog were restored. Notably, Hsp90 associated with Oct4 and Nanog in the same cellular complex and protected them from degradation by the ubiquitin proteasome pathway, suggesting that Oct4 and Nanog are potential novel Hsp90 client proteins. In addition, Hsp90 inhibition reduced the mRNA level of Oct4, but not that of Nanog, indicating that Hsp90 participates in Oct4 mRNA processing or maturation. Hsp90 inhibition also increased expression of some protein markers for mesodermal lineages, implying that Hsp90 suppresses mesodermal differentiation from ESCs. These findings support a new role for Hsp90 in maintaining ESC pluripotency by sustaining the level of multiple pluripotency factors, particularly Oct4 and Nanog. | Regulation of embryonic stem cell pluripotency by heat shock protein 90. |
30908508 | Objective: To investigate the regulation of CD4+CD25+ Regulatory T cells (Tregs) on pro-inflammatory adhesion molecules, Krüppel-Like Factor-2 (KLF-2) and its downstream transcriptional targets in human umbilical vein endothelial cells (HUVECs) impaired by ox-LDL and the mechanisms of it. Methods and results: HUVECs were cultured in the continuous presence of ox-LDL(0 mg/L,25 mg/L,50 mg/L,100 mg/L) for 4, 6, 12 and 24 hours to allow identification of early-and late-induced genes, respectively, whereas non-stimulated controls were taken at 0 hours. The expression of pro-inflammatory adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin, KLF-2 and its target genes eNOS, PAI-1 were determined by real time RT-PCR and/or western-blot analysis. Expression of pro-inflammatory adhesion molecules, KLF-2, eNOS and PAI-1 in HUVEC cultured alone or with anti-CD3 mAbs activated Tregs, followed by addition of ox-LDL (50 mg/L) for 6 hours, are compared to expression levels in control cultures. Ox-LDL treated HUVECs increased pro-inflammatory adhesion molecules expression, as well as increased PAI-1 but decreased eNOS expression accompanied with significant downregulating of KLF-2 at a dose and time dependent manner. Furthermore, ox-LDL increased pro-inflammatory adhesion molecules but inhibited KLF2 expression was reversed by addition of Tregs. Small interfering RNA reduced endogenous KLF-2 expression and partly reversed the suppressive effect of Tregs on HUVECs activation, which strongly implicate KLF-2 as a transcriptional regulator of the Tregs-mediated effects in endothelial cells. Mechanism studies reveal that Treg-mediated KLF2 expression in HUVECs impaired by ox-LDL requires cell contact as well as soluble factors. Conclusions: Tregs could protect endothelial function that is largely dependent on KLF2 and its downstream transcriptional targets regulation involving cell-to-cell contact and soluble factors. | CD4+CD25+Foxp3+Regulatory T Cells Protect Endothelial Function Impaired by Oxidized Low Density Lipoprotein via the KLF-2 Transcription Factor |