bluuebunny/crossref_metadata_2025 huggingface dataset:
Subpopulations of Multipotent Non‐Hematopoietic Progenitor Cells from Human Bone Marrow for the Treatment of Tissue Injury
Authors: Spees Jeff
Published: June 2021

The reparative properties of bone marrow multipotent stromal cells (MSCs) have been attributed in part to the paracrine action of secreted factors that reduce cell death, influence inflammatory responses, and promote the healing of injured tissues. Although typical human MSCs (hMSCs) constitute a heterogeneous population of non‐hematopoietic progenitor cells, different hMSC preparations are often assumed to be similar cells with similar properties. We compared typical hMSCs with multipotent non‐hematopoietic progenitor cell subpopulations isolated by magnetic‐activated cell sorting against the CD133 epitope (CD133‐derived MSCs, CD133dMSCs) or CD271 (p75LNGFR, p75dMSCs). Microarray assays of expressed genes demonstrated that the three cell isolates were distinct from one another. We analyzed the secretion of selected growth factors and cytokines at different cell densities and under normoxic or hypoxic conditions. The hMSCs, CD133dMSCs, and p75dMSCs differed significantly in their protein secretion responses. For cell therapy, it is desirable to have standardized preparations of cells with predictable effects in vivo. Intracardiac (arterial) administrations of CD133dMSCs or concentrated conditioned medium (CdM) from CD133dMSCs provided dramatic neuroprotection relative to vehicle controls and significantly reduced cortical infarct volumes in mice following cerebral ischemia.
Planar cell polarity: from cells to tissues to organisms
Authors: Axelrod Jeffrey
Published: June 2021

Many epithelial tissues display Planar Cell Polarity (PCP), with individual cells having coordinated subcellular asymmetry along an axis orthogonal to the apical‐basal axis. A variety of developmental anomalies are attributable to defects in PCP, including deafness, open neural tube defects, polycystic kidneys and others. Based on studies in Drosophila, we have proposed that a three‐tiered system governs PCP. The first tier orients polarity with respect to the tissue axes. The second tier amplifies the asymmetric signal derived from the first tier and enforces local alignment between neighboring cells. The third tier translates molecular asymmetry into specific morphological manifestations. The second tier comprises a mechanism by which PCP proteins achieve an asymmetric subcellular distribution, with distinct complexes segregating to the proximal and distal sides of the cell. I will describe recent experiments and our current model of the mechanism by which this asymmetric distribution is achieved, and by which polarity is communicated from cell to cell. I will then describe results indicating that in vertebrates, the underlying mechanisms identified in Drosophila are conserved. However, a function for primary cilia in vertebrate, but not Drosophila, PCP signalling has been implicated. I will discuss roles for vertebrate PCP, and present a model for the role of primary cilia in vertebrate PCP signaling.
Fibulin‐5‐integrin binding and vessel development
Authors: Yanagisawa Hiromi
Published: June 2021

Fibulin‐5 is an ECM protein highly expressed in large arteries during development and is essential for elastic fiber formation. Fibulin‐5 functions as an adaptor protein by binding to tropoelastin, cross‐linking enzymes, and microfibrilar scaffold during elastic fiber assembly. Fibulin‐5 also functions as an inhibitory matrix for proliferation and migration of vascular SMCs. To examine the significance of integrin‐binding of fibulin‐5 in vascular development, we generated a mutant mouse that expresses fibulin‐5 (RGE) by knock‐in strategy. Fbln5RGE/RGE mice were viable and no abnormality was observed in elastogenic tissues, indicating that fibulin‐5‐integrin binding was not essential for elastic fiber formation. Recently, it was reported that fibulin‐5 competes with fibronectin in binding to alpha4beta1 and alpha5beta1 integrins in an RGD‐dependent manner, but does not activate integrin downstream signaling. We found that the level of reactive oxygen species (ROS) was significantly up‐regulated in response to fibronectin in Fbln5‐/‐ and Fbln5RGE/RGE mouse embryonic fibroblasts. In addition, increased periendothelial ROS production in mutant mice resulted in a paradoxical reduction of angiogenesis in tumor bearing tissues. These findings highlight the non‐elastogenic role of fibulin‐5 mediated by integrin binding in the vessel wall.
Cell structure control of endothelial mechanotaxis under fluid shear stress
Authors: Helmke Brian P. , Lin Xiefan
Published: June 2021

Endothelial cells in quiescent monolayers exhibit triphasic mechanotaxis in response to unidirectional fluid shear stress. In order to determine whether pre‐existing cell structure dictates the direction of cell migration under fluid shear stress, micropatterning strategies were implemented. Cells with polygonal shapes in center regions of wide lines (100‐200 μm) exhibited triphasic mechanotaxis similar to that in confluent monolayers, but elongated cells near the edges migrated primarily along their axis of elongation and did not undergo mechanotaxis under either parallel or perpendicular flow. When denuded areas were created perpendicular to the microlines, elongated cells migrated into the denuded area preferentially in the flow direction only after they were released from their preset elongation. Sparsely populated cells on the upstream edges of wide microlines continued migrating parallel to their major axes after onset of perpendicular flow, unlike single cells on an unpatterned surface that exhibited immediate downstream mechanotaxis. Only when their elongated structure was released after ~7 h of flow did these cells start to migrate in the flow direction. Thus, pre‐existing cell structure suppresses mechanotaxis of endothelial cells, an important mechanism for endothelial wound healing in applications such as vascular stents and bypass grafts. Supported by NIH grant HL‐071958.
Tales of Transposons: Mechanisms and Applications
Authors: Craig Nancy Lynn , Mitra Rupak , Xie Kefang
Published: June 2021

Mobile elements are ubiquitous genome components sequences derived from mobile elements can make up large fractions of genomes. Our research is focused on DNA‐only elements that move by excision from the donor site, followed by insertion into the target site.

We have dissected the transposition mechanisms of the hAT and piggyBac superfamiles of elements. We have also isolated hyperactive elements to probe their transposition mechanism and to use as tools for genome engineering.

Heretofore, no active DNA‐only element has been isolated from a mammal. We have now isolated an active DNA‐only element from the little brown bat Myotis lucifugus.
Promoter‐proximal pausing of Pol II enhances gene expression
Authors: Adelman Karen , Gilchrist Daniel , Nechaev Sergei , Dos Santos Gilberto
Published: June 2021

Recent work from our lab and others has revealed that many genes in higher eukaryotes are regulated at a step after recruitment of RNA polymerase II (Pol II) to a gene's promoter. In particular, we have found that Pol II initiates transcription and then pauses during early elongation of Drosophila genes that are involved in development or the response to environmental signals. Release of this promoter‐proximally paused Pol II occurs quickly upon gene activation, allowing for a rapid induction of transcription. As described below, we have discovered that in addition to facilitating rapid gene activation, promoter‐proximally paused Pol II can enhance both basal and induced gene expression by maintaining a permissive chromatin architecture around a gene's promoter.

The Negative Elongation Factor (NELF) is a transcription regulatory complex that induces pausing of Pol II during early transcription elongation. We report that RNAi against NELF decreases promoter‐proximally paused Pol II and, surprisingly, that knock‐down of this "negative" factor has largely negative effects on gene expression. Investigation of the down‐regulated promoters shows that significant loss of Pol II pausing is accompanied by increased nucleosome occupancy of the promoter region. These results indicate a dynamic, antagonistic relationship between paused Pol II and nucleosomes, and reveal a mechanism through which paused Pol II can poise a gene for further or future induction.
Regulation of Hsp70‐linked ubiquitination by CHIP and Bag2
Authors: Misra Saurav , Xu Zhen , Kohli Ekta , Page Richard Christopher
Published: June 2021

As part of intracellular protein quality control, chaperones such as Hsp70 not only refold misfolded proteins and prevent their aggregation, but also act to degrade and dispose of such proteins to mitigate their harmful influence. The key ubiquitin ligase CHIP binds to the C‐terminus of Hsp70 and ubiquitinates client proteins bound to this chaperone. In contrast, the Hsp70 nucleotide exchange factor Bag2 antagonizes CHIP both by promoting client refolding and by directly inhibiting client ubiquitination by CHIP. Our goal is to determine the mechanistic basis for CHIP‐mediated ubiquitination of Hsp70 clients and for the antagonistic activity of Bag2. Using X‐ray crystallography, NMR, and biochemical assays, we have 1) defined the interaction between CHIP and the E2 enzyme UbcH5; 2) discovered a secondary interaction site for CHIP on the alpha‐helical lid domain of Hsp70; 3) defined the novel structural basis of the nucleotide exchange activity of Bag3; 4) obtained evidence that Bag2 may sterically inhibit CHIP by binding to the E2‐ubiquitin conjugate recruited by CHIP. These results give us a clearer understanding of the biochemistry and regulation of chaperone‐linked ubiquitination. Our research was funded by the NIH (RO1‐GM080271), the American Heart Association (SDG 0735313N) and by the Ralph Wilson Medical Research Foundation.
Evolution of the eukaryotic endomembrane system ‐ first and last ancestors
Authors: Field Mark C , Dacks Joel B
Published: June 2021

The eukaryotic endomembrane system is responsible for biosynthesis and transport of proteins and lipids and for the definition of the major subcellular compartments. It is also considered a hallmark property of the eukaryotic cell. Recent work indicates that the endomembrane system is very ancient, predates the radiation of eukaryotic lineages and was present in the last common eukaryotic ancestor (LCEA). However, there is clear evidence for lineage‐specific adaptations, and most significantly for many such advances being restricted to animals and fungi (Opistokhonta). Further, several examples of Archaeal paralogues of factors involved in membrane transport are emerging, indicating a more intimate relationship with prokaryotic systems than originally was apparent. Additional relationships between the endomembrane coatomer system and the nuclear pore complex (NPC) have now emerged, which suggest that a modern NPC architecture was also present in the LCEA and further evidence for ancient establishment of the basic endomembrane system. Finally a model for the evolution of specificity in membrane transport will be discussed.
Recruitment and assembly of the mitochondrial membrane fission machinery
Authors: Shaw Janet M.
Published: June 2021

Mitochondria often form tubular networks that are remodeled by fission and fusion. Fission is essential for maintenance of mitochondrial morphology and distribution, and is important for neuronal function and development. Yeast mitochondrial fission requires the conserved, dynamin‐related GTPase, Dnm1. Dnm1 self assembles to form spirals that encircle mitochondrial tubules at sites of constriction and fission. Dnm1 targeting to mitochondria requires a membrane‐anchored protein called Fis1 and its binding partner, Mdv1. Although structural studies suggested that the N‐terminus of Mdv1 forms a clamp around the Fis1 cytoplasmic domain, these proteins do not form a simple heterodimer. Instead, our biophysical studies indicate that Mdv1 dimerizes via a coiled‐coil domain in the middle of the protein. Thus, the basic Dnm1 receptor on mitochondria is likely a heterotetramer composed of two Fis1 proteins bound to an Mdv1 homodimer. New data reveal that a short helix in Dnm1p is required for recruitment of dimeric Dnm1 from the cytoplasm to the C‐terminal beta propeller domain of Mdv1. Mutations in this Dnm1 helix do not impair self‐assembly. Rather, these mutations block Dnm1 binding to Mdv1, Dnm1 membrane recruitment, and fission complex assembly. These findings provide new information about the nature of the Dnm1 membrane receptor complex and the manner in which Dnm1 recognizes this receptor.
Dynamics of lipid transfer by phosphatidylinositol transfer protein during membrane transport at the endoplasmic reticulum‐Golgi membrane interface
Authors: Cockcroft Shamshad , Holic Roman , Carvou Nicolas
Published: June 2021

Mammalian phosphatidylinositol transfer proteins, (PITP‐alpha and PITP‐beta) are highly conserved 32 kDa proteins that contain a hydrophobic cavity that can sequester either phosphatidylinositol or phosphatidylcholine. PITPs in vitro can facilitate inter‐membrane lipid transfer and this requires association of the soluble proteins with membranes. Phosphatidylinositol, the precursor for all phosphoinositides is synthesised at the endoplasmic reticulum and its distribution to other organelles could be facilitated by PITPs. Based on the localisation of the individual PITPs, recent studies indicate a requirement for PITPs for diverse functions including membrane traffic at the Golgi, neurite outgrowth and cytokinesis. In vivo individual PITPs are required for specific functions as mice deficient in PITP‐alpha die shortly after birth because of neurological defects, while PITP‐beta deficiency is embryonically lethal. Here we describe recent studies examining the localisation of PITP‐beta in interphase cells and its re‐localisation during cell divison. In interphase cells, PITP‐beta dynamically interacts with the Golgi and endoplasmic reticulum membranes constantly in cells and is required for membrane traffic between these two organelles. Using RNAi interference to deplete PITP‐beta proteins, the interface between membrane traffic and phosphatidylinositol binding /transfer metabolism will be described.
Nuclear receptor dependent chromatin remodeling
Authors: Archer Trevor Keith
Published: June 2021

The necessary compaction of DNA with histones to form chromatin provides a multifaceted opportunity to regulate gene expression in response to environmental and developmental ques. Nuclear receptors represent a particularly useful class of transcription factors have played a profound role in the investigation of the underlying mechanisms of chromatin biology. The physical and functional interaction between receptors and the ATP dependent chromatin remodeling complexes reveal the importance of a diverse group of associated or co‐activator proteins. We have made use of specific human and mouse cancer cell line models to manipulate the expression of these varied molecules to understand the specific roles they play in the activation of gene transcription by steroid hormones. The focus of our attention has been the human BRG1 remodeling complex ATPase and its associated factors (BAFs). Our studies revel that chromatin remodeling is a necessary but not sufficient condition for hormone mediated transcription. Further, mutational analysis the remodeling complex enzymatic core reveals critical requirements for specific subunits of the complex. Our studies contribute to an evolving view of gene activation that places chromatin remodeling at the centre of this vital biological process.
High‐Throughput Analysis of RNA Structure by SHAPE Chemistry
Authors: Weeks Kevin , Watts Joseph , Wilkinson Kevin , Gorelick Robert
Published: June 2021

Single‐stranded RNA viruses encompass a broad class of infectious agents and, in their diverse forms, cause the common cold, cancer, AIDS, and many other serious health threats. Viral replication is regulated at many levels, including using essential, conserved genomic RNA structures to exploit and circumvent host biology. However, the vast majority of potential regulatory elements within viral RNA genomes are uncharacterized. We use high‐throughput SHAPE (selective 2′‐hydroxyl acylation analyzed by primer extension) to quantify RNA backbone flexibility at single nucleotide resolution and from which robust structural information can be immediately derived. We detect specific protein‐RNA interactions inside HIV virions and identify three RNA binding functions for the viral nucleocapsid protein. Analysis of the structure of an entire, authentic, ~9,200 nucleotide HIV‐1 genome at single nucleotide resolution reveals that the HIV‐1 genome, and potentially most large coding RNAs, is punctuated by numerous previously unrecognized, but conserved, RNA regulatory motifs. High‐throughput SHAPE reveals a comprehensive view of HIV‐1 RNA genome structure and further application of this technology will make possible newly informative analysis of any RNA in a cellular transcriptome.
Kinetics of Peptide Aggregation in Neurodegenerative Disease
Authors: Murphy Regina M , Du Jiali , Walters Robert , Tobelmann Matthew
Published: June 2021

Peptide aggregation is linked to Alzheimer's (Aβ), Huntington's (polyglutamine expansion in huntingtin), and other neurodegenerative diseases, motivating our studies into the kinetics of aggregation. Polyglutamine peptides have been used as models of aggregation. The accepted hypothesis is that these peptides aggregate via nucleated polymerization whereby the nucleus is a β‐sheet monomer. We examined polyglutamine peptide aggregation experimentally, and conclude that it is more likely that polyglutamine peptides first associate into large oligomers that lack defined secondary structure, which then slowly rearrange to β‐sheet aggregates. Additionally, we examined the role of polyglutamine length on the structure, stability, and aggregation properties of a host protein. We have carried out extensive investigations into Aβ; aggregation kinetics. Here too, our data are consistent with a model in which Aβ; first assembles into oligomers that lack secondary structure, and then mature into insoluble β‐sheet fibrils. Currently we are pursuing the hypothesis that transthyretin (TTR) may be protective against Aβ toxicity. We examined the effect of several TTR variants on Aβ and saw a strong correlation between acceleration of aggregation and inhibition of toxicity. Preliminary data suggests that the stability of TTR tetramers plays a strong role in regulating TTR‐Aβ interactions.
Pancreatic regeneration: role of pancreatic progenitors
Authors: Bonner‐Weir Susan
Published: June 2021

The regenerative process in the pancreas is of particular interest since diabetes, whether type 1 or type 2, results from an inadequate amount of insulin‐producing β‐cells. The presence of pancreatic stem/progenitor cells has been suggested by the observation of islet neogenesis, the formation of new islets seen as budding of hormone positive cells from the ductal epithelium. Our data from the regeneration rat model of partial pancreatectomy led us to hypothesize that differentiated pancreatic ductal cells were the pancreatic progenitors after birth, that with replication they regressed to a less differentiated phenotype and then could differentiate to form new acini and islets. To test this hypothesis, we took a direct approach of genetically marking ductal cells using carbonic anhydrase II (CAII) as a duct cell‐specific promoter to drive cre recombinase in Cre‐lox lineage tracing experiments. We show that CAII‐expressing pancreatic cells act as progenitors that give rise to both new islets and acini after birth and after injury (ductal ligation). It is still unclear if all, or only a subpopulation, of the ductal cells have this potential. This identification of an in vivo progenitor for all differentiated pancreatic cell types has implications for a potential expandable source for new islets for replenishment therapy for diabetes either in vivo or ex vivo.
How do GPCRs Catalyze G Protein Activation?
Authors: Hamm Heidi E.
Published: June 2021

Structural and biophysical studies provide powerful tools for the study of G protein structure and function. High resolution structures of heterotrimeric G proteins, isolated G protein subunits (in both the active and inactive states), and inactive hepatahelical receptors have been determined, however there is no available structure of an activated receptor in complex with G‐protein. This interaction is the rate limiting step in G protein activation, and results in release of GDP, allowing for uptake of GTP and activation of downstream effectors. The structural determinants involved in G protein interaction with activated receptors is of particular interest to our group, and we have used both EPR and fluorescence studies to map this interface. In addition, we have used structural and functional mimetics of the receptor bound state to elucidate the details of receptor‐mediated G protein activation using crystallographic and biochemical approaches.
G protein coupled receptor heterodimerization leads to distinct signaling
Authors: Devi Lakshmi A.
Published: June 2021

Protein‐protein interactions govern a large number of biological processes. It is well established that a variety of cell surface receptors interact with each other to form dimers and that this is essential for their function. A number of G‐protein coupled receptors have been recently shown to physically associate and in some cases this association has been found to alter their function such as ligand binding, signaling and trafficking properties. We have used opioid receptors as a model system with the intent of examining the consequences of receptor‐receptor interactions on analgesia and addiction. Two types of opioid receptors, μ and δ physically associate with each other to form heterodimers and this leads to changes in agonist affinity, efficacy and/or potency. Using heterodimer‐selective antibodies, we show that opiate treatment, under conditions that lead to the development of tolerance, induces upregulation of the μ‐δ heterodimer in distinct brain regions. We also show that the upregulated heterodimer constitutively recruits β‐arrestin and this leads to changes in the spatio‐temporal dynamics of signaling. This, in turn, leads to differential activation of transcription factors resulting in long lasting changes in gene expression. These results, for the first time, show that the G protein‐coupled receptor heterodimer can function as a novel signaling unit. Taken with the fact the levels of the heterodimer levels tend to be upregulated during pathology, these results suggest that the heterodimer represents a unique target for the development of novel therapeutics for the treatment of pathologies involving G protein‐coupled receptors.
High chronic intakes of eicosapentanoic (EPA) and docosahexanoic acids (DHA) are associated with desirable lipid profile and reduced C‐reactive protein (CRP), and attenuate effects of obesity on triglycerides (TG) and CRP
Authors: Makhoul Zeina , Kristal Alan R , Gulati Roman , Luick Bret , Bersamin Andrea , Boyer Bert , Mohatt Gerald V
Published: June 2021

We studied associations of high intake of EPA + DHA, measured as percentage of total red blood cell fatty acids (the ω‐3 index [ω3I]), with markers of cardiovascular disease (CVD) risk in a unique, population‐based sample of 357 Yup'ik Eskimos, whose mean ω3I (10%±3%) is roughly 3 times higher than the US average. Generalized additive models were used to examine covariate‐adjusted associations of ω3I with lipids, inflammatory cytokines, insulin resistance, and blood pressure. Each 1% increase in ω3I was associated with linear increase in total cholesterol (3.7 mg/dl), LDL (3.97 mg/dl), HDL (0.84 mg/dl), and ApoA1 (1.2 mg/dl) (all P<0.001), and a 5% decrease in CRP (P=0.02). Negative associations of ω3I with TG and IGF‐I were nonlinear: the association with TG was stronger at ω3I >12%; for IGF‐1 the association was restricted to ω3I <8%. Positive associations of obesity with TG and CRP were significantly weaker at high compared to low ω3I. Compared to normal weight participants, obesity was associated with a 40.7 mg/dl increase in TG and a 0.06 mg/L increase in CRP at 5% ω3I; at 15% ω3I these differences were reduced to 20.3 mg/dl and 0.03 mg/L respectively. For most biomarkers of disease risk, associations with ω3I were constant across a broad range of ω3I. The negative consequences of obesity on TG and CRP, both strong predictors of CVD, may be partially ameliorated by high intakes of EPA + DHA. Supported by NIH grant P20 RR16430 (Mohatt, PI).
Nutrition labels at point‐of‐selection in a food‐service operation improves patrons' meal selection
Authors: Chu Yong H. , Frongillo Edward A. , Jones Sonya J. , Kaye Gail L.
Published: June 2021

Objectives

The current Nutrition Labeling and Education Act exempts food‐service operations from disclosing nutrition information. As policy makers address short‐comings of this exemption, evidence informing the effects of nutrition labels in food‐service operations on meal selection is needed. This study examined changes in meal selection by patrons when nutrition labels were provided at the point‐of‐selection.

Methods

A quasi‐experimental, single‐group, interrupted time‐series design was used to examine the daily sales data of three periods: pre‐treatment, treatment and post‐treatment. Piecewise linear regression was employed to examine changes in the average energy content of entrées and paired t‐test was used to detect differences in sales across the periods.

Results

Average energy content of entrées purchased by patrons dropped immediately when nutrition labels were made available at point‐of‐selection and average energy content of entrées increased gradually when nutrition information was removed. No significant change in entrée sales between periods occurred.

Conclusions

Use of nutrition labels reduced average energy content of entrées purchased without reducing overall sales. These results provide support for strengthening the nutrition labeling policy in food‐service operations.

Grant Funding Source

None
Influence of differing types and formats of menu labeling
Authors: Colby Sarah Elizabeth , Heidal Kimberly , Johnson Chad , Stallings Taft , Gross Kevin
Published: June 2021

Objective

Nutrition labeling on restaurant menus is now required in some locations. This research investigated the influence of type and format of menu nutrition labeling on consumers' ability to estimate calories and their intended purchases.

Methods

Young adults (N=464) were surveyed using one of six different menus. Menu versions included control, calories only, guideline daily amount system, better for you symbol, index value, and a traffic light system.

Results

Overall, menus with nutrition information analyzed by three calorie groupings were related to fewer calories ordered (1346 vs. 1569 calories ordered) and improved ability to estimate caloric values (586 vs. 821 calories estimation error), x2 (2, 442) = 11.11, p < 0.01 and x2 (35, 442) = 62.27, p< 0.01, respectively. The guideline daily amount system had the largest decrease in calories ordered (1003 calories ordered). The calories only menu had the smallest error between actual calories ordered and ability to identify calories ordered (237 calorie estimation error). Females were more likely than males to decrease calories ordered when nutrition information was present x2 (2, 442) = 8.88, p <0.05.

Conclusions

Research on the influence of type and format of nutrition information on menus with other populations is needed. Results of this and future research needs to be considered when developing menu labeling policies.
High energy consumption among infants of mothers with depressive symptoms is mediated through indulgent feeding
Authors: Hurley Kristen Marie , Black Maureen M , Caulfield Laura E
Published: June 2021

Background

Depression is a risk factor for obesity and increased energy consumption among women. Because children learn through imitation and food exposure, the effects of maternal depression may extend through their children's eating behaviors.

Objective

To examine the relationships among maternal depressive symptoms, feeding styles, and infant diet.

Methods

Maternal mental health, feeding styles, and a 24 hour diet recall were assessed by an interviewer‐administered telephone survey among 689 mothers of WIC receiving infants.

Results

Maternal depressive symptoms predicted higher infant energy consumption (β=59.9; CI: 1.9‐116.9; P<0.05). The relationship was mediated by indulgent feeding styles (MacKinnon Test = 1.50; P<0.05).

Conclusion

Among low income mothers, maternal depression is characterized by indulgent feeding styles, possibly resulting in excess infant energy consumption.
Protective effects of polyphenolic compounds on oxidative stress‐induced cytotoxicity in PC12 cells
Authors: Crispo James A.G. , Ansell D. , Piché M. , Eibl J. , Khaper N. , Ross G. M. , Tai T.C.
Published: June 2021

Elevated reactive oxygen species (ROS) have been implicated in the pathogenesis of many diseases, including atherosclerosis and Parkinson's. Foods rich in polyphenols such as fruits, wines and teas have proven to decrease oxidative stress. Further, antioxidant properties of polyphenols increase cell viability under oxidative stress conditions and increase overall health. In the current study 12 polyphenols were screened for their ability to increase viability in PC12 cells subject to oxidative stress induced via cobalt chloride (CoCl2) and hydrogen peroxide (H2O2). Results from MTT assays show that pre‐treatment with 50µM methyl gallate increases cell viability by 26.6% (P<0.01) under H2O2 stress and does not increase viability under CoCl2 stress. Pre‐treatment with 100µM epigallocatechin gallate (EGCG) shows a 63.4% (P<0.01) increase in viability compared to control, however shows no viability increase in stress conditions. Treatments with 50µM myricetin and gallic acid show no effect on basal viability and decrease viability when delivered as a pre‐treatment prior to H2O2 exposure. Remaining polyphenols did not alter basal viability or increase viability under stress. Lastly, DCFDA determination of intracellular ROS confirms the ability of screened polyphenols to significantly reduce ROS levels. These results suggest that methyl gallate and EGCG may have potential therapeutic properties.
Harvest year and growing region but not processing affect flavonoid content and antioxidant capacity of California almond skins.
Authors: Bolling Bradley W , Dolnikowski Gregory , Blumberg Jeffrey B , Chen C‐Y. Oliver
Published: June 2021

The consistency of the flavonoid content and antioxidant capacity of plant foods across growing regions and harvest years as well as the impact of processing has received little attention. We have characterized the influence of these factors in California almond skins on their total phenols (via the Folin‐Ciocalteu reaction), flavonoid profile (by LC‐MS), and Ferric Reducing Antioxidant Power (FRAP) value. The processing (fumigation, steam pasteurization, and dry roasting) of Butte, Carmel and Nonpareil almond varieties did not change their flavonoid content or FRAP value. Almonds harvested in 2006 and 2007 had 13% less flavonoids than in 2005, but their total phenols and FRAP values were unchanged. Almonds grown in southern California contained 21% less total flavonoids (5.50 mg/100 g) than those from northern California, with their lower content of kaempferol‐3‐O‐rutinoside (78%), naringenin‐7‐O‐glucoside (56%), epicatechin (34%), dihydrokaempferol (30%), naringenin (28%), and isorahamnetin‐3‐O‐rutinoside (18%). However, the ratio of individual to total flavonoids was not different between almonds grown in northern, central or southern California. Almonds from the southern region had 29% less total phenols but similar FRAP values compared to the northern region. Thus, growing region and harvest year affect the total phenolic and flavonoid content but not the antioxidant activity of almond skins.
Selenoprotein‐dependent modulation of expression of hematopoietic prostaglandin D2 synthase in macrophages
Authors: Prabhu K. Sandeep , Gandhi Ujjawal H , Vunta Hema
Published: June 2021

Inadequate selenium nutrition is associated with an increase in reactive oxygen species that is seen in several pathologies where inflammation is a key component. In our pursuit to understand the underlying mechanisms involved in the selenium‐dependent production of anti‐inflammatory 15‐deoxy‐delta‐12,14‐prostaglandin J2 (15d‐PGJ2) from arachidonic acid, we have focused on the transcriptional regulation of hematopoietic PGD2 synthase (H‐PGDS). H‐PGDS is a rate‐limiting enzyme that catalyzes PGH2 to PGD2, which is then converted to 15d‐PGJ2. Here we demonstrate an increase in the expression of H‐PGDS in macrophages as a function of selenium concentration, upon LPS stimulation. Knockdown of selenoproteins using shRNA for selenophosphate synthetase‐2 or using organoselenium compounds that do not release selenium showed that incorporation of selenium into selenoproteins is essential for the transcriptional up‐regulation of H‐PGDS as well as the production of 15d‐PGJ2. Preliminary studies also indicate a positive feedback loop where 15d‐PGJ2 up‐regulates H‐PGDS expression via the activation of peroxisome proliferator activated receptor (PPAR)‐gamma. These results indicate a novel anti‐inflammatory mechanism of selenium via the transcriptional up‐regulation of H‐PGDS. NIH DK077152 (KSP)
Sep15 knockdown decreases tumorigenicity and metastasis of a colon cancer cell line
Authors: Tsuji Petra A , Irons Robert , Ouyang Ping , Carlson Bradley , Yoo Min‐Hyuk , Xu Xue‐Ming , Hatfield Dolph , Gladyshev Vadim , Davis Cindy
Published: June 2021

Selenium is a cancer preventive agent and protection is partially mediated through selenoproteins. The role of the 15 kDa selenoprotein (Sep15) in colon cancer etiology was assessed by stably transfecting mouse colon CT‐26 cells with two different siRNA constructs that specifically targeted Sep15 removal, resulting in >90% knockdown of Sep15 as determined by 75Se‐labeling of cells, RT‐PCR and western blot analysis. The growth of siSep15 knockdown cells was reduced compared to control cells, and siSep15 cells formed significantly (p<0.05) less colonies in soft agar compared to the control (668 ± 33 and 512 ± 83 for siSep15‐1 and siSep15‐2, respectively, versus 2480 ± 140 for the control). Lung metastasis was significantly reduced (p<0.001) in BALB/c mice injected with siSep15 knockdown cells (5x105) compared to the plasmid control (70 ± 9 and 8 ± 2 for siSep15‐1 and siSep15‐2, respectively, versus >250 in control mice). These data suggest that knockdown of Sep15 in a murine colon cancer cell line inhibits the cells' ability to grow under anchorage‐independent conditions and reduces lung metastasis. Funded by NCI Intramural support, the Cancer Prevention Fellowship Program and the Division of Cancer Prevention.
First release of the Dietary Supplement Ingredient Database: Nutrient estimates and methodology for 18 vitamins and minerals in adult multivitamin/minerals (MVMs)
Authors: Andrews Karen , Roseland Janet , Zhao Cuiwei , Feinberg Matthew , Middleton Angela , Holden Joanne , Douglass Larry , Dwyer Johanna , Picciano Mary Frances , Fisher Kenneth , Saldanha Leila , Yetley Elizabeth
Published: June 2021

The Dietary Supplement Ingredient Database (DSID) is a federal initiative to provide analytical validation of ingredients in dietary supplements. The first release on vitamins and minerals in adult MVMs is now available. Multiple lots of >100 representative adult MVMs were chemically analyzed for their nutrient content. Mean percent differences from label were calculated for each nutrient and compared to labeled levels using regression analysis. Prediction equations identified both linear (n=15) and quadratic (n=3) relationships. Standard errors of the mean (SEM), predicted values were calculated and include variation among lots within products, variation among products at each labeled level and residual variation about the regression line. For 11 of the 18 nutrients (iron, niacin, magnesium, zinc, vitamin E, manganese, potassium, copper, phosphorus, vitamin C and vitamin B‐12), the predicted mean % difference from label at the most common adult MVM level ranged from 0 to10% above label. For four nutrients (riboflavin, folic acid, calcium and thiamin), the predicted mean % difference was >10 to 20% above label. For the remaining 3 nutrients (vitamin B‐6, selenium and iodine), the predicted mean % difference was >20 to 30% above label. These analytically validated results can be used in population studies tracking MVM supplement usage to more accurately quantify nutrient intake. Funding: ARS/USDA & ODS/NIH Y1CN501006
Overweight and Obesity in Mexican Scholar Children
Authors: Shamah‐Levy Teresa , Méndez‐ Humaran Ignacio , Cuevas‐ Nasu Lucia , Morales‐ Ruan María del Carmen , Mundo‐Rosas Verónica
Published: June 2021

Objective

The aim of this study was to describe the prevalence of overweight and obesity (OW +O) and to assess its association with some risk factor in a probabilistic sample of Mexican scholars.

Methods

Information from 34,045 children (>6 y) extracted from the Mexican National Health in Publics Schools Survey in Mexico (ENSE‐2008) was included in the analysis. We examined body mass index (BMI) in relation to demographic variables, sweet beverages consumption, and physical activity.

Results

Our results revealed that 1 of every 3 Mexican school children had OW+O (32.3%).The prevalence of overweight and obesity was adjusted by sex, age, region of dwelling (North, Center, South and Mexico City), and consumption of sweet beverages. The prevalence of OW +O was associated with aged children (>10y OR 1.15, p< 0.001); Sex (boys: OR 1.2 p=0.025; consumption of sweet beverages (1.1, p=0.008).

Conclusions

Overweight and obesity is becoming a public health problem in Mexico. It should be approached through aggressive interventions targeted to school age children at risk, in order to reduce rapidly the prevalence of overweight and obesity, thus limiting its negative short‐ and long‐term effects on other health outcomes. Supported by the Rio Aronte Foundation, and Fondo de Apoyo al Programa Intersectorial de Educación Saludable.
Comparison of the prevalence of Overweight and Obesity between scholar and non scholar children in Mexico
Authors: Cuevas Lucia , Villalpando Salvador , Avila Marco Antonio , Shamah Teresa
Published: June 2021

Using data from the National Health and Nutrition Survey (ENSANUT ‐2006) in Mexico, and selecting a sample of children (aged 6 ‐11y), this study describes the prevalence of overweight and obesity and its correlation with school attendance, evaluating the BMI by the IOTF criteria.

The children who attend school had a greater prevalence of overweight and obesity (27.5%) compared with non attending children 21.6 (5.7 pp lower), this children are involved in infantile work or do not attend school because of their poor condition.

In both groups the highest prevalence of overweight and obesity were in the Northern region of the country (attending school 30.8% vs non attending 27.4%) compared with the Southern region (attending school 23.4% vs non attending 18.5%), this latter region, is the poorest in the country.

The findings can be used for planning and targeting interventions aimed to prevent and control the important increase in overweight and obesity observed in school age children in Mexico.
Association of PAT proteins with cytoplasmic lipid droplets in mouse enterocytes
Authors: Lee Bonggi , Zhu Jiabin , Wolins Nathan E. , Cheng Ji‐Xin , Buhman Kimberly K.
Published: June 2021

The process of dietary fat absorption (DFA) by the absorptive cells of the intestine, enterocytes, is important in regulating energy balance in whole animals. Recently, we found that enterocytes dynamically store triacylglycerols (TGs) in cytoplasmic lipid droplets (CLDs) during DFA. To further our understanding of the process of DFA and regulation of TG rich CLD synthesis and catabolism within enterocytes, we investigated the expression and localization of PAT protein family members in enterocytes of mice under acute and chronic dietary challenges. We found that adipophilin and TIP47 are the only PAT proteins expressed in mouse intestinal mucosa. In mice acutely and chronically challenged by dietary fat, we imaged the cellular localization of TIP47 and adipophilin using immunofluorescence in combination with Coherent anti‐Stokes Raman scattering microscopy (CARS) to image TG in CLDs We found that TIP47 is expressed in the cytoplasm under all conditions but only associates with CLDs after an acute challenge. Adipophilin, on the otherhand is only expressed and associated with CLDs in enterocytes of chronic high‐fat fed mice. These results suggest distinct roles for TIP47 and adipophilin in DFA and ultimately regulation of whole animal energy balance.

Grant Funding Source

Purdue Research Foundation
Delayed lactogenesis and excess neonatal weight loss are common across ethnic and socioeconomic categories of primiparous women in northern California
Authors: Dewey Kathryn G , Nommsen‐Rivers Laurie , Cohen Roberta J , Chantry Caroline J. , Peerson Janet M
Published: June 2021

We evaluated early lactation success in a multi‐ethnic cohort of 448 primiparas in Sacramento, CA. Key outcomes were sub‐optimal infant breastfeeding behavior (SIBB), onset of stage II lactogenesis >72 h postpartum (delayed OL) and excess neonatal weight loss (> 10% of birth weight by 70‐98 h). Prevalence of SIBB was 69% at 2‐46 h, 34% at 3‐4 d, and 24% at 1 wk of age, and did not differ by maternal ethnicity, age, income group or education. Delayed OL occurred in 42% of women (34% of African‐Americans, 40% of Hispanics, and 44% of non‐Hispanic whites and Asian‐Americans); it was more common in women > 30 y of age than in those < 30 y (56% vs. 37%, p=0.0004), and in those with some vs. no college education (47% vs. 36%, p=0.03). Excess neonatal weight loss (excluding infants who received > 60 mL of formula at 0‐48 h) occurred in 18% and was more common in infants of mothers with higher age (28% if > 30 y vs. 14% if < 30 y, p=0.01), income (22% vs. 12%, p=0.048) and education (22% vs. 10%, p=0.03); differences across ethnic groups were marginally significant (8% of African‐Americans, 11% of Hispanics, 18% of non‐Hispanic whites and 31% of Asian‐Americans; p=0.08). We conclude that early breastfeeding problems such as delayed OL have reached epidemic proportions in this population of primiparas, especially among women with greater age and education. Further analyses will explore the biological and behavioral underpinnings for these findings.

Supported by a grant from the Department of Health and Human Services, Maternal Child Health Branch.
Serum 25‐hydroxyvitamin D as a determinant of multiple sclerosis outcome following a pediatric demyelinating event
Authors: Hanwell Heather Elaine Courtney , Vieth Reinhold , Bar‐Or Amit , Magalhaes Sandra , Sadovnick Dessa , Arnold Douglas , Banwell Brenda
Published: June 2021

Overview

Vitamin D has been implicated in risk of autoimmune diseases including multiple sclerosis (MS). Children presenting with initial acquired demyelinating syndromes (ADS) are at high risk of subsequent MS diagnosis and thus, provide an opportunity to explore vitamin D as a determinant of MS risk.

Objective

We sought to determine whether serum 25‐hydroxyvitamin D [25(OH)D] at pediatric ADS presentation is predictive of subsequent MS diagnosis.

Methods

Incident ADS cases were enrolled in a national pediatric prospective study. Serum collected at baseline was analyzed for 25(OH)D. MS was defined as a relapse confirmed on clinical exam.

Results

Of the 137 children enrolled, 21 (15%) were diagnosed with MS after a mean of 9.5 ± 7.6 mos (±SD). Serum 25(OH)D at ADS presentation was lower in children diagnosed with MS (45.8 ± 20.4 nmol/L) versus those remaining free of relapses to date (62.6 ± 29.3 nmol/L; p = 0.003). Quartiles of serum 25(OH)D at presentation strongly predicted subsequent risk of MS diagnosis: 27% of children in the lowest serum 25(OH)D quartile (=35.7 nmol/L) developed MS, compared with only 6% of the children in the highest quartile (= 77.9 nmol/L; trend p = 0.012).

Conclusion

Our results are consistent with the hypothesis that vitamin D is protective against autoimmune disease. These findings justify clinical trials involving intervention with vitamin D as a means to prevent MS.

Grant Funding Source

Multiple Sclerosis Scientific Research Foundation, Multiple Sclerosis Society of Canada, Canadian Institutes of Health Research
Selenium biomarkers in Chinese subjects supplemented with selenium
Authors: Burk Raymond F , Xia Yiming , Hill Kristina E , Motley Amy K
Published: June 2021

Biomarkers for selenium are used to assess its nutritional status and its potential toxicity. We studied selenium biomarkers in selenium‐deficient Chinese subjects who received selenium supplements for 20 weeks and also in subjects living in a high‐selenium area of China (Enshi County). In supplemented subjects, 24‐h urinary selenium excretion increased in a dose‐dependent manner but it increased twice as much in subjects receiving selenomethionine (semet) as in those receiving comparable amounts of selenium as selenite. Hair selenium concentrations mirrored plasma selenoprotein P for both forms of selenium when the amount of selenium ingested was within the nutritional requirement. These results support earlier conclusions that the bioavailability of selenium in human beings is greater as semet than as selenite and confirm that hair selenium is useful as a biomarker of selenium nutritional status. In Enshi County, plasma samples from city dwellers and farmers were studied. Plasma selenoprotein concentrations were not different between them, but selenium concentrations were greater in farmers, 470 ± 170 mcg/L (n=10), than in city dwellers, 100 ± 27 mcg/L (n=10). These results indicate that farmers have a higher selenium intake in the form of semet than city dwellers, probably because the geographical sources of their food are different. Also, they confirm that high selenium intakes do not cause selenoproteins to rise above their optimal levels. Supported by NIH DK58763.
Knockout of the selenocysteine tRNA[Ser]Sec gene (Trsp) in mouse macrophages
Authors: Carlson Bradley A , Yoo Min‐Hyuk , Kim Jin Young , Shrimali Rajeev K , Irons Robert , Park Jin Mo , Hatfield Dolph L
Published: June 2021

Selenium has been shown to play a role in proper immune function and protection of the immune system from oxidative damage, though the form of selenium (i.e., low molecular weight selenocompounds and/or selenoproteins) utilized in this process is not clear. In this study, we have specifically removed the expression of selenoproteins in macrophages of mice by crossing a mouse containing a floxed selenocysteine (Sec) tRNA gene with a mouse expressing the Cre‐recombinase gene under the control of the lysozyme M (LysM) promoter. The selenoprotein knockout mice have no apparent phenotype in the absence of an immune challenge. However, removal of selenoproteins in macrophages showed an accumulation of reactive oxygen species (ROS) levels in knockout bone marrow‐derived macrophages compared to wild type controls. Knockout macrophages also exhibit impaired invasiveness using an in vitro matrigel assay. Correspondingly, microarray analysis has identified altered expression of several extracellular matrix and fibrosis‐associated genes and these results have been verified by qPCR analysis. The altered gene expression does not appear to be a result of increased ROS levels, as treatment with NAC had little effect on altered gene expression. These findings suggest that selenoproteins exert immune regulatory functions at multiple levels. This research was supported by the Intramural Research Program of the NIH, NCI, CCR.