bluuebunny/crossref_metadata_2025 huggingface dataset:
Function & Immunity of Stem Cell‐Derived Hematopoietic Cells
Authors: Bhatia Mickie
Published: June 2021

Human embryonic stem cells (hESCs) derived from the human embryo, and more recently adult dermal fibroblasts induced to be reprogrammed into pluripotent stem cells (hIPCs), represent two potential sources of cells for regenerative cell replacement therapies. However, the fundamental aspects of both cellular and molecular biology required to control differentiation to a specific lineage using pluripotent cells remain the single and most important obstacle to bringing this therapy to the clinic. Hematopoietic stem cell (HSC) transplants have been and are currently the most prevalent and successful stem cell therapy to date. Our lab and others have been defining these signals and cellular phenotypes of cells emerging towards the hematopoietic lineage from both hESCs and hIPSCs. Although improvements can be made to increase the quantity of hematopoietic cell types with primitive blood cell function, the methods to generate hematopoietic cells that possess in vivo repopulating function similar to somatic HSCs have been elusive. We will discuss how current knowledge of hematopoietic differentiation from pluripotent cells relates to opportunities in both basic research and future clinical goals.
Natural 13C abundance of plasma glucose as a potential biomarker for dietary “simple” sugar intake.
Authors: Cook Chad M , Alvig Amy L , Liu Yu Qiu (David) , Schoeller Dale A
Published: June 2021

INTRODUCTION

A need exists for objective biomarkers of dietary intake, as self‐report is often subject to inaccuracies.

PURPOSE

We tested the validity of measuring the fraction of dietary carbohydrate (CHO) from cane sugar and high fructose corn syrup (C4 sugars) using natural 13C abundance of plasma glucose (Glc).

METHODS

In a randomized cross‐over design, 5 subjects were fed 3 weight‐maintaining diets for 7 days, with a two‐week washout between diets. Diets differed in the fraction of total CHO energy from C4 sugars (5%, 16%, or 32%). During each diet, blood samples were drawn at 8am and 4pm on days 1, 3, and 5 and at 8am, 10am, 12pm, 2pm, and 4pm on day 7. δ13C abundance of plasma Glc was analyzed using isotope ratio mass spectrometry.

RESULTS

Within each diet, δ13C of 8am Glc did not change from baseline with increasing time on diet. There was a positive correlation (R2 = 0.88) between Day 7 ‐ 10am δ13C Glc and % of breakfast CHO from C4 sugars. Also, δ13C Glc of combined 10am ‐ 4pm plasma from Day 7 within each diet demonstrated a positive correlation (R2 = 0.90) with % of total daily CHO from C4 sugars.

CONCLUSION

Gluconeogenesis attenuates δ13C abundance of fasting Glc, as the δ13C abundance of Glc from C4 sugar consumption does not persist overnight. Postprandial plasma Glc could be used as a biomarker for contributions of C4 sugars to a previously ingested meal. (Funding provided by The National Dairy Council).
Dietary L‐lysine supplementation reduces de novo lipogenesis via AMPK activation and malonyl‐CoA suppression
Authors: Hirabayashi Yuri , Murakami Hitoshi , Inoue Yoshiko , Fujieda Takeshi , Kobayashi Hisamine
Published: June 2021

We reported that dietary L‐lysine supplementation increased fat oxidation in mice fed a high‐fat diet (EB 2006). Dietary L‐lysine supplementation also decreases diet induced obesity as well as hyperlipidemia. In this experiment, we investigated the effect of L‐lysine on de novo lipogenesis, malonyl‐CoA content, and AMPK activation. (Exp1) Male C57BL/6J mice were injected i.p. with 2H2O and fed a normal diet (LF; 5% fat w/w) or the diet supplemented with 3.0 % L‐lysine monohydrochloride (Lys) for an hour. 2H labeling of palmitic acid and water in plasma were measured, and fractional synthesis rate (FSR) of palmitic acid was calculated. The result showed that Lys suppressed FSR of palmitic acid (LF: 2.78±0.68 %/h vs Lys: 1.91±0.32 %/h). (Exp2) Male C57BL/6J mice were fed a high‐fat diet (HF; 25% fat w/w) or the high‐fat diet supplemented with 3.0% Lys for 8 hours in dark period. Malonyl‐CoA contents and phosphorylation level of AMPK in liver and skeletal muscle were measured. Malonyl‐CoA content of liver in Lys group was less than that in HF group during feeding period. P‐AMPK/AMPK level was increased by L‐lysine at 2 and 4 hours after feeding in liver (2h: 1.27 fold, 4h: 1.36 fold). In skeletal muscle, Lys didn't affect malonyl‐CoA content and P‐AMPK/AMPK level. In conclusion, our data suggests that dietary supplementation of L‐lysine increases fat oxidation and inhibits de novo lipogenesis via AMPK activation and malonyl‐CoA suppression in liver.
Reduced Luminal Calcium and Chaperone Function in Response to Elevated Free Fatty Acids in Liver Cells
Authors: Pagliassotti Michael , Wang Dong , Wei Yuren
Published: June 2021

Chronic exposure to elevated free fatty acids, in particular long chain saturated fatty acids, provokes endoplasmic reticulum (ER) stress, activation of the unfolded protein response (UPR) and cell death in a number of cell types. The perturbations to the ER that instigate ER stress and activation of the unfolded protein response to fatty acids in hepatocytes have not been identified. The present study employed H4IIE liver cells and primary rat hepatocytes to examine the hypothesis that saturated fatty acids induce ER stress via effects on ER luminal calcium stores and reduced chaperone function. Exposure of H4IIE liver cells and primary hepatocytes to palmitate and stearate reduced thapsigargin‐sensitive calcium stores and induced multiple markers of ER stress and UPR activation over similar time courses (6h). Increased cell death was observed following 16h of exposure. Co‐incubation with oleate prevented the reduction in calcium stores, induction of ER stress markers and cell death. Since several ER molecular chaperones function in a calcium‐dependent manner, the effects of chemical chaperones on palmitate‐mediated ER stress and cell death was examined. The chemical chaperones, 4‐phenyl butyric acid and taurine‐conjugated ursodeoxycholic acid, reduced palmitate‐mediated ER stress and cell death. These data suggest that reduced ER luminal calcium and protein folding capacity contribute to long chain saturated fatty acid‐mediated perturbations in the ER.
Exploring the perivascular niche of mesenchymal stem cells
Authors: Simmons Paul
Published: June 2021

There is considerable interest in the potential therapeutic application of mesenchymal stem cells (MSC) in a wide variety of clinical settings. While initial studies focused on the bone marrow origin of MSC, burgeoning data now demonstrate that cells with many of the phenotypic and functional properties of their counterparts in bone marrow are also present in a range of other tissues such as adipose tissue and teeth. A significant barrier to the study of MSC biology is the lack consensus regarding specific markers of MSC facilitating their identification and isolation coupled with the current lack of knowledge regarding the precise ontological origin of MSC in the post natal animal. However one observation about which many investigators are in accord is the perivascular location of putative MSC which has led to the proposal that the pericyte represents the cellular identity of MSC. This presentation will focus on recent data in the mouse model in which transcriptional profiling of highly purified, prospectively isolated MSC and vascular endothelial cells from the bone marrow has allowed us to begin to explore the interaction between MSC and their vascular niche.
Gross anatomy for the legally blind: A case study of the education strategy adopted for a gross anatomy student with bilateral coloboma
Authors: Deane Andrew Stewart , Brueckner Jennifer
Published: June 2021

Gross anatomy instructors are often called upon to modify education strategies to accommodate students with physical disabilities. Owing to the emphasis on visual identification inherent to the study of anatomy, visual impairments are particularly limiting to gross anatomy students. Here the authors present a case study of the dual approach education and curricular modifications implemented to accommodate a legally blind student with bilateral coloboma. The first approach involved the extensive use of available technology to enhance the student's capacity to access course materials and cadaveric specimens in particular (i.e. closed caption monitors, JORDY glasses). The second approach involved a dedicated assistant with prior gross anatomy training to assist with dissection and to serve as an interface between the student and the dissection group, as well as between the student and the cadaver. The assistant was embedded with the student in a dissection group and worked directly with the student on individual dissection tasks. In addition to learning accommodations, unique accommodations were also required for testing and evaluation, particularly for practical exams. Specific guidelines were established for student palpation of prosected specimens. This case study is intended to serve as a guideline for the future education and examination of students with visual impairments.
The CrkRS/CDK12 kinase is activated by a novel isoform of Cyclin K and phosphorylates the C‐terminal domain of RNA Pol II
Authors: Morin Gregg B , Kuzyk Michael A , Tien Jerry F , Schaeffer Emily , Cheng S.‐W. Grace
Published: June 2021

CrkRS (Cdc2‐related kinase, Arg/Ser), or CDK12 (Cyclin Dependent Kinase 12), is a ser/thr kinase believed to coordinate transcription and RNA splicing. While CrkRS complexes were known to phosphorylate the C‐Terminal Domain (CTD) of RNA Pol II, the responsible cyclin was not known. However, others showed that co‐expression of CrkRS and Cyclin L could affect the alternative splicing of a model substrate. Using immunoprecipitation and mass spectrometry (IP‐MS), we identified the protein constituents of endogenous CrkRS complexes. In addition to several spliceosome‐related proteins, we identified a novel 65 kDa isoform of Cyclin K, whereas the known isoform is 43 kDa. We did not observe Cyclin L. Previously, endogenous Cyclin K complexes were known to phosphorylate the CTD, yet the responsible kinase was not identified. Using yeast‐two hybrid and co‐expression experiments others identified CDK9 as a Cyclin K partner and that CDK9/Cyclin K could regulate transcription. Using IP‐MS, we show that Cyclin K complexes isolated from mammalian cells contain CrkRS but do not contain CDK9, and that CDK9 complexes contain Cyclin T1 and not Cyclin K, within detection limits. The co‐expression of CrkRS with either isoform of Cyclin K showed increased CTD kinase activity compared to controls. Our data suggest the primary cyclin partner for CrkRS is Cyclin K and that Cyclin K is sufficient to activate CrkRS to phosphorylate the CTD.
Translational control by hepatic eIF2‐alpha kinases: Constitutive activation/autophosphorylation of heme regulated inhibitor (HRI) in wild type (wt) mice and compensation by PERK in HRI‐knockout mice
Authors: Acharya Poulomi , Correia Maria Almira
Published: June 2021

Phosphorylation of the eukaryotic initiation factor eIF2‐α subunit controls protein translation via any of four known eIF2α kinases. We have shown that in cultured rat hepatocytes heme‐depletion activates HRI and suppresses global hepatic protein synthesis. This effect is heme‐reversible. To determine the role of hepatic HRI in regulating protein synthesis, we examined cultured hepatocytes from human, rat, and wt or HRI‐knockout (KO) mice. Immunoblotting (IB) analyses revealed that hepatic HRI exists in all species except KO mice, albeit at lower than erythroid levels. While rat or human hepatic HRI exists largely as a 76kDa species, mouse HRI exists as a constitutively phosphorylated ≈ 92kDa species. Heme‐depletion of wt mouse hepatocytes resulted in further eIF2α phosphorylation, but this was not heme‐reversible, unlike that of rat HRI. To determine whether another eIF2α kinase contributed to this effect we examined the ER‐stress inducible PKR‐like ER kinase, PERK. Indeed, IB analyses revealed that hepatic heme depletion markedly induced both PERK and phosphoPERK content in wt mouse hepatocytes. Genetic deletion of HRI constitutively induced PERK expression and phosphorylation and led to accumulation of ubiquitinated proteins in HRI‐KO hepatocytes, thus indicating basal ER‐stress. These findings reveal that PERK may play a significant compensatory role in hepatic translational control. Supported by DK26506 and DK26743.
The Yin and Yang of biochemistry education: Using physical models to teach the process of science
Authors: Herman Tim , Colton Shannon , Franzen Margaret
Published: June 2021

We would like biochemistry students to build their understanding of the invisible molecular world on a solid foundation of chemistry, physics and the "big ideas" of biology. But at the same time that biochemistry instruction should be anchored to these broad, overarching concepts (the Yin), the devil is in the details (the Yang). Science moves from being merely "interesting" to being "fascinating" as students understand enough of the subject to begin to appreciate the details underlying complex molecular mechanisms, as well as the process of science that has revealed these details. The challenge to educators is to initially capture students' interest in the subject, and to keep them engaged long enough to begin to see the beauty and the molecular logic of living systems that is revealed in the details. Our recent experience suggests that accurate, physical models of molecular structures‐‐‐ based on atomic coordinates and constructed by 3D printing technology ‐‐‐ can play an important role in both the Yin and Yang of biochemistry education. The models initially capture students' interest, and keep them engaged long enough to stimulate more sophisticated, detailed questions regarding molecular structure and function. This work is supported by an NSF‐CCLI Award 0618688.
Black bean and chickpea consumption reduce glycemic response as part of a rice meal
Authors: Thompson Sharon V. , Winham Donna M. , Hutchins Andrea M.
Published: June 2021

This study examined the effects of consumption of 50 grams of available carbohydrate from three test meals: plain white rice (control), black beans with rice, and chickpeas with rice in insulin sensitive adult women. Food portioning was done by gram weight, not volume and the carbohydrate content of the meals was equal. These weighed meal portions were approximately 3/4 cup of rice for the control, and about ½ cup of beans with ½ cup of rice for the black bean and chickpea treatments. Black beans and chickpeas have similar carbohydrate content per gram weight despite being different species. Using a randomized, crossover, placebo‐controlled design, 9 participants consumed each of the three test meals on different mornings, at least 7 days apart. Blood samples collected at time 0 (fasting), and at 30, 60, 90, 120 minutes post‐meal were analyzed for plasma glucose.

The glucose response based on the incremental area under the curve to the rice/bean meals showed a significant difference by treatment (ANOVA, p=0.017). Results of a paired t‐test indicated that the glucose response curve was significantly different at two of the four time points for the black bean meal as well as the chickpea meal in comparison to rice alone, 60 minutes post‐prandial (p=0.041), and 90 minutes post‐prandial (p=0.002). Black bean and chickpea intake as part of a meal can reduce the glycemic response to high glycemic index foods, such as white rice.
Sweetened beverage consumption and risk of metabolic syndrome in Mexican adults
Authors: Denova Edgar , Talavera Juan O , Huitrón Gerardo G , Mendez Pablo , Salmerón Jorge
Published: June 2021

Objective

To examine the relationship between Sweetened beverage (SB) consumption and components of metabolic syndrome (MS) in Mexican population.

Methods

We performed a cross‐sectional analysis of data from adults participating in the baseline assessment of the Health Workers Cohort Study in the Mexican States of Morelos and Mexico. Information on participants' socio‐demographic conditions, dietary patterns and physical activity were collected via self‐administered questionnaire. Anthropometric and clinical measures were assessed with standardized procedures. The definition of MS was determined using criteria from Adult Treatment III. The associations of interest were evaluated by means of lineal and logistic regression models.

Results

A total of 5,240 individuals aged 20 to 70 years (mean 34.4 years old; SD=11.5) were evaluated. Overweight/obesity prevalence was 56.6%. The prevalence of MS in this sample was 26.6%. We found that for each additional daily SB serving consumed, participants experienced an average increase of 43.2 mg/dL (CI 95%; 7.3 ‐ 79.1 mg/dL) in triglycerides and a decrease of HDL‐c by 12.2 mg/dL (CI 95%; ‐16.1 ‐ ‐8.6 mg/dL). Subjects consuming more than two servings/day of SB were at a 2.0 (CI 95%; 1.2‐3.1) times greater risk of MS than those who did not consume SB.

Conclusions

Our data support the hypothesis that SB consumption increases the risk of MS in Mexican adults, possibility by providing excessive calories and large amounts of rapidly absorbable sugars.
Energy validity increases with increasing numbers of days of DietDay: a self administered web‐based 24 hour recall
Authors: Arab Lenore , Jardack Patricia , Liu Weiqing , Schoeller Dale
Published: June 2021

The validity of assessment of caloric intakes using a 24 hour recall depends upon the number of days assessed. Antagonistic dynamics balance the benefit of increasing days to average out intra individual variation in intake against the burden of additional days of recall. The Energetics study was conducted to validate caloric intake using a multipass, food image‐based, computerized tool (DietDay) against total energy expenditure measured by doubly labeled water (DLW). 163 Caucasians and African Americans conducted 8 repeat assessments on independent days. The Pearson's correlation between DLW and the mean of 3 DietDays was 0.34 ; for 7 days was 0.41. The mean total energy difference between methods was minimal, but increased with increasing numbers of days of assessment. Total energy expenditure in this group averaged 2546 (SD 550). This was within 9 kcal/d of the reported mean caloric intakes for two days (2555 SD 1303), 140 kcal of the six days intake average (2406 SD 950) and 209 kcal of the eight day average (2337 SD 866). The correlation increased from .16 to .42 with increasing numbers of days of recall from 1 to 8. As might be expected; increasing numbers of days increased the size of the correlation coefficient but decreased the closeness to the true energy intake. The latter may be indicative of reporting fatigue with increasing numbers of days reported. Supported by NIH R01CA105048.
Carnitinomic and metabolomic studies in translational research
Authors: Goodmon Kathleen , Parker Jessica E. , Jones Lauren L. , Cerutti Soledad , Johnson Jodie V. , Powell David , Borum Peggy R.
Published: June 2021

Metabolomics is the global analysis of metabolites within various tissues and biological fluids. The metabolome more closely represents the phenotype than the genome or proteome as metabolite fluxes are a product of both genetic and environmental influences. Thus, metabolomics may provide insight into the nutritional, metabolic, and general health status during different stages of the life cycle and during pathological conditions. The workflow is as follows: formulate hypothesis ‐ design study ‐ collect samples ‐ prepare and analyze samples to identify compounds ‐ analyze data ‐ evaluate hypothesis and generate hypotheses ‐ apply to patient care. Although experts in each area of the workflow are needed, at least one team member must provide continuity from formulation of hypotheses to patient care. We are testing the hypotheses that the plasma carnitinome will change in piglets between days 2 through 8 of life, in young healthy adults before and after being placed on a trial ketogenic diet, and in patients with epilepsy when treated with ketogenic therapy. The long term goal is to more effectively and efficiently translate research concerning changes in the carnitinome and metabolome into practical solutions for patients with various pathological conditions. This continuity and integration of knowledge from basic science to the clinic will accelerate research from discovery to improved patient care.
Systemic, sustained delivery of chemopreventive agent is effective against dibenzo[a,l]pyrene‐induced DNA adducts
Authors: Russell Gilandra Keshawn , Vadhanam Manicka V , Kausar Hina , Gupta Ramesh C
Published: June 2021

Only a handful of chemopreventive agents have been found effective against lung tumorigenesis presumably due to limited bioavailability. In this study we determined relative potential of a chemopreventive agent given by a novel sustained delivery system versus the diet in diminishing carcinogen‐induced DNA adducts. Using 32P‐postlabeling we first determined that when dibenzo[a,l]pyrene (DBP) (0.5 mg/kg, b.w.) was given i.p. in five equal doses on alternate days, it induced nearly three times more lung DNA adducts in female A/J mice than when it was given as a single dose. Next, mice were given oltipraz either via the diet (400 ppm) or by subcutaneous silastic implants (two, 2‐cm implants containing 5 mg), or sham treatment, and then challenged with DBP (5 x 100 μg/kg, i.p.). Analysis of the lung DNA five days after the last DBP treatment showed > over 47% reduced DNA adducts by oltipraz implants compared with control (106 ± 36 versus 201 ± 118 adducts/1010 N); adduct levels remained unaffected by the dietary oltipraz. Measurement of residual oltipraz in the implants showed that a total of < 3 mg of oltipraz was delivered by implants compared with 29 mg by diet over 18 days. Our data suggest that systemic sustained delivery by implants may circumvent bioavailability problem associated with dietary route for some compounds, and lower the effective dose. (CA‐118114, ES‐011564, and KY Lung Cancer Res. Program).
Cranberries, but not blueberries, prolong survival in spontaneously hypertensive stroke‐prone rats
Authors: Shaughnessy Kevin Stewart , Slemmer Jennifer , Scanlan Adam , Gottschall‐Pass Katherine , Sweeney‐Nixon marva
Published: June 2021

We have shown that feeding cranberries (Vaccinium. macrocarpon, CB) prolongs survival in spontaneously hypertensive stroke‐prone rats (SHRSP). Here, we evaluated the effect of feeding blueberries (V. angustifolium, BB) on survival and evaluated possible mechanisms. SHRSP were fed control diet or a diet enriched with 3% CB or 3% BB until the onset of stroke. Weight, feed intake, and systolic blood pressure (BP) were monitored weekly; urinary F2‐isoprostanes, a marker of oxidative stress, were measured at the end of the study. BB lowered BP by 6‐10% at weeks 5‐7, whereas CB lowered BP by 10% only at week 5. BB did not prolong survival, whereas CB increased survival by 40%. Rats with high BP at wks 4 and 5 were more likely to demonstrate early stroke symptoms (p<0.01). Feed efficiency over the first 5 wks also was positively correlated with days to stroke onset (p=0.018, control; p=0.052, CB). Weight at wk 5 was positively correlated with days to stroke in CB (p=0.038), but not in control‐fed SHRSP (p=0.41). In CB‐fed SHRSP, but not control rats, F2 isoprostanes were negatively correlated with BP at wk 5 (p=0.034), and positively correlated with days to stroke (p=0.027). These results suggest that effects on BP and weight/ feed efficiency can contribute to prolongation of stroke onset in SHRSP. Since F2‐isoprostanes are markers of lipid peroxidation, it is surprisingly that their levels promote survival. (Funded by AIF and NSERC).
Excessive Superoxide Production And Endothelial Dysfunction In Cerebral Arteries Of Atherosclerotic Mice Occur In The Absence Of Lesions And Are Due To The Activity Of Nox2‐Containing NADPH Oxidase
Authors: Miller Alyson , Drummond Grant , De Silva T. Michael , Judkins Courtney , Sobey Christopher
Published: June 2021

This study tested whether enhanced superoxide (O2−) production by Nox2‐containing NADPH oxidase leads to endothelial dysfunction in cerebral arteries of high fat‐fed (21% fat & 0.15% cholesterol, 5 weeks of age for 7‐14 weeks) apolipoprotein E‐null (ApoE−/−) mice. O2− production by cerebral arteries from C57Bl6/J wild‐type (WT; n=19), ApoE−/− (n=26) and novel Nox2−/−/ApoE−/− (n=23) mice was measured using L‐012 (100 μM)‐enhanced chemiluminescence. Endothelial function was assessed in middle cerebral arteries (MCA) using a perfusion myograph via the constrictor response to N‐nitro‐L‐arginine methyl ester (L‐NAME; 100 μM). Atherosclerotic lesions were prominent in the aortae but not cerebral arteries of ApoE−/− mice. O2− production was elevated in cerebral arteries from ApoE−/− (35±5 x 103 counts/mg; P<0.05) vs. WT (16±2 x 103) mice. In Nox2−/−/ApoE−/− mice, O2− production was not elevated (11±1 x103). L‐NAME‐induced contractions of MCA from ApoE−/− mice (δdiameter = ‐13±4 %; P<0.05) were <50% smaller vs. WT (‐34±2 %). In Nox2−/−/ApoE−/− (‐37±10 %) mice endothelial function was comparable to WT. In the presence tempol (O2− scavenger; 1 mM), endothelial function was similar in ApoE−/− (‐25±5 %) and WT (‐24±3 %) mice. Thus, in the absence of lesions, excessive O2− production and endothelial dysfunction occurs in cerebral arteries of atherosclerotic mice. These changes appear to be dependent on Nox2.
Breast Cancer Metastasis Depends on Proteasome Degradation of Regulator of G‐protein Signaling 4
Authors: Xie Yan , Wolff Dennis W. , Wei Taotao , Wang Bo , Kirui Joseph K. , Jiang Haihong , Qin Jianbing , Abel Peter W. , Tu Yaping
Published: June 2021

Aberrant signaling through G‐protein coupled receptors promotes metastasis, the major cause of breast cancer death. We identified Regulator of G‐protein Signaling 4 (RGS4) as a novel metastasis suppressor. By blocking signals initiated through Gi‐coupled receptors, such as protease‐activated receptor 1 and CXC chemokine receptor 4, via its GTPase Activating Protein (GAP) activity, RGS4 disrupted Rac1‐dependent lamellipodia formation, a key step involved in metastasis. An RGS4 GAP‐deficient mutant failed to inhibit the metastatic abilities of breast cancer cells in both in vitro and a mouse xenograft model. Interestingly, both established breast cancer cell lines and human breast cancer specimens showed that the highest levels of RGS4 protein were expressed in normal breast epithelia and that RGS4 down‐regulation by proteasome degradation is an index of breast cancer metastasis. Proteasome blockade increases endogenous RGS4 protein to levels that markedly inhibit breast cancer cell migration and invasion, which could be reversed by an RGS4‐targeted shRNA. Our findings point to the existence of a mechanism for posttranslational regulation of RGS4 function, which may have important implications for the acquisition of a metastatic phenotype by breast cancer. Preventing RGS4 degradation should retard the spread of breast cancer cells and making them targets for surgery, radiation and immune treatment.
Interleukin‐4 is a Potential Regulator of Satellite Cell Function in Response to Acute Myotrauma in Humans
Authors: Toth Kyle G , McKay Bryon R , Phillips Stuart M , Tarnopolsky Mark A , Parise Gianni
Published: June 2021

Interleukin‐4 (IL‐4) has been implicated in myoblast fusion and growth; however, the localization of IL‐4 to satellite cells (SC) in humans, has not been demonstrated. Furthermore, the role of IL‐4 in SC in response to acute injury in humans has not been investigated. Eight subjects (age 22 ± 1 y; 79 ± 8 kg) performed 300 maximal unilateral leg lengthening contractions (3.14 rad.s−1) and muscle samples were collected at PRE, 4 (T4), 24 (T24), 72 (T72), and 120 hr (T120) post intervention. Immunohistochemical analysis revealed that IL‐4 protein was localized with Pax7+ SC at T4, T24 and at T72, with no visible IL‐4 detected at PRE. IL‐4 and IL‐4R mRNA demonstrated significant (p < 0.05) 4.4 fold upregulations at T4 while IL‐4R maintained this high expression at T24 post exercise (p < 0.05). Similarly, a downstream target of IL‐4, SOCS1, demonstrated a 2.9 fold increase (p < 0.05) at T4. Furthermore, IL‐13 mRNA levels remained low until T120 where it became significantly increased compared with all other time points (p < 0.05). Pearson product correlation analysis demonstrated positive associations between IL‐4, IL‐4R (p < 0.001, R2 = 0.67) and SOCS1 (p < 0.001, R2 = 0.69) mRNA expression levels. Furthermore, IL‐4R mRNA correlated with SOCS1 expression (p < 0.001, R2 = 0.57). These data suggest a role for IL‐4 in the SC response to acute myotrauma in humans, possibly signalling via the STAT6 pathway.
Ac‐SDKP Prevents Renal Injury and Dysfunction in Rats with Subtotal Renal Ablation
Authors: Liao Tang‐Dong , Yang Xiao‐Ping , D'Ambrosio Martin A. , Zhang Yanlu , Rhaleb Nour‐Eddine , Carretero Oscar A.
Published: June 2021

N‐acetyl‐seryl‐aspartyl‐lysyl‐proline (Ac‐SDKP) is a natural tetrapeptide hydrolyzed by angiotensin‐converting enzyme (ACE). In patients, ACE inhibitor treatment increases plasma Ac‐SDKP 4‐ to 6‐fold. We have shown that Ac‐SDKP exerts anti‐fibrotic and anti‐inflammatory effects on the kidney in hypertensive rats. However, its effect on renal function is unknown. We tested whether Ac‐SDKP prevents renal injury and dysfunction in 5/6 nephrectomy (5/6NX)‐induced hypertension. Sprague‐Dawley rats were divided into 4 treatment groups: 1) sham+vehicle; 2) sham+Ac‐SDKP (800 μg/kg/day); 3) 5/6NX+vehicle; 4) 5/6NX+Ac‐SDKP for 4 weeks. We found that (1) Rats with 5/6NX had high blood pressure (BP), decreased glomerular filtration rate (GFR) from 193 ± 29 to 31 ± 6 μl/min/100mgkw (p < 0.005), and increased albuminuria from 0.22 ± 0.06 to 65.16 ± 15.23 mg/24 hrs (p < 0.005), and increased inflammatory cell infiltration and fibrosis; (2) Ac‐SDKP prevents these effects without affecting BP; (3) Ac‐SDKP preserved slit diaphragm protein nephrin expression from 2.4 ± 0.9 for 5/6NX + Veh to 12.3 ± 2.4 % for 5/6NX + Ac‐SDKP (p < 0.005). In conclusion, Ac‐SDKP prevents renal injury and dysfunction in rats with 5/6NX, these effects may be associated with its anti‐fibrotic and anti‐inflammatory properties, and preservation of nephrin expression. This study was supported by NIH (HL‐28982).
Selective over expression of central ACE2 prevents baroreflex dysfunction in the chronic heart failure
Authors: GAO LIE , Farrar Rachael , Wang Wei , Lazartigues Eric D , Zucker Irving H
Published: June 2021

Angiotensin‐converting enzyme 2 (ACE2) and Ang (1‐7) enhances baroreflex sensitivity (BRS). On the other hand Ang II depresses BRS and down regulates NOS expression, especially in the setting of chronic heart failure (CHF). Down regulation of brain NOS expression plays a role in the blunted BRS and sympatho‐excitation in the CHF state. We hypothesized that central over expression of ACE2 normalizes sympathetic outflow and BRS via up regulating NOS in this syndrome. Experiments were carried out in mice with selectively overexpressed human ACE2 in the brain (driven by the synapsin promoter; synhACE2) and wild type mice (WT), which were divided into sham (S) and CHF groups. Blood pressure, heart rate, and renal sympathetic nerve activity (RSNA) were recorded under anaesthesia. BRS was tested by iv injection of phenylephrine. We found that, (1) ACE2 and eNOS expressions were lower in WT‐CHF than WT‐S, but not different between synhACE2‐CHF and synhACE2‐S mice; (2) baseline RSNA was significantly lower in synhACE2‐CHF mice compared to WT‐CHF mice(RSNA: 47.4 ± 6.1 to 81.3 ± 7.6 % of Max; P < 0.05); (3) synhACE2‐CHF mice exhibited improved BRS compared with WT‐CHF mice (Maximum Slope: 3.4 ± 0.6 to 1.8 ± 0.8 %/mm Hg; P < 0.05). These results suggest that, selective over expression of ACE2 in the brain prevents impairment of BRS and sympatho‐excitation in the CHF state, probably via an up regulation of central NOS expression.
Following an anoxic insult, a hippocampal neural circuit of the Syrian hamster, a hibernator, is more protected than the hippocampus of the rat, a nonhibernator
Authors: Becker Jeffrey J. , Horowitz John M. , Hamilton Jock S. , Horwitz Barbara A.
Published: June 2021

Environmental adaptations enable the hibernating Syrian hamster to reduce its oxygen consumption to 1% of its consumption under euthermic conditions, but whether these adaptations provide the hamster with added neuroprotection under ischemic conditions is not well studied. We tested the hypothesis that, at 30oC, the hamster hippocampus can recover function after an anoxic insult more rapidly than the rat hippocampus. The response amplitude of CA1 neurons in hippocampal slices from hibernating hamsters and rats was measured every minute throughout the experiment, beginning with a 15 minute control period in oxygenated buffer (95%O2/5%CO2). Oxygen was then replaced by nitrogen (95%N2/5%CO2) for a 15 minute period (the anoxic insult). Slices were then returned to the oxygenated buffer for a 30 minute recovery period. Three minutes after the anoxic insult, the hamster response had recovered to 84.3 + 4.2 % of control (14 slices, 4 animals) while the rat response had only recovered to 28.0 + 11.5 % of control (17 slices, 5 animals). These differences are significant (P<0.05) and support the hypothesis that a neural network in hibernating hamsters recovers function more rapidly after an anoxic insult than does the network in the rat. This study was supported by an UC Davis President's Undergraduate Fellowship award to JJB.
Ischemic postconditioning protects against cerebral ischemia/reperfusion‐induced calcium overload in mice
Authors: SHEN Jia , ZHOU Jingyi , PENG Yunlong , XIA Qiang
Published: June 2021

OBJECTIVE

This study was to investigate whether postconditioning could reduce ischemia/reperfusion (I/R) induced calcium overload in neurons and the relative mechanism.

METHODS

Male C57BL/6 mice (23‐28g) were randomly divided into Sham (PBS injection without ischemia) group, Control (PBS injection with ischemia/reperfusion) group, Postconditioning (PBS injection, ischemia followed by 3 circles of 15 sec reperfusion and 15 sec occlusion before permanent reperfusion) group (PC group), N‐methyl‐D‐aspartate (NMDA receptor activator, NMDA) injection + PC group (NMDA group), MK‐801 (NMDA receptor non‐competitive antagonist) injection + PC group (MK‐801 group). Intracerebroventricular injections of PBS, NMDA or MK‐801 respectively were performed 30 min before 15min period of global ischemia. Two hours after reperfusion, acute hippocampus slices were prepared for intracellular calcium concentration detection by Fluo‐3/AM.

RESULTS

The calcium concentration were significantly increased in control group and NMDA group, and suppressed in PC group and MK‐801 group. The decrease of free calcium level by PC therapy was abolished by NMDA.

CONCLUSION

The ischemia postconditioning reduces the calcium overload through suppressing the activity of NMDA receptor.
LPS‐INDUCED STAT3 AND CYTOKINE PROTEIN IN MOUSE BRAIN
Authors: Datta Subhash C , Opp Mark R
Published: June 2021

The peripheral immune system and the brain communicate through signaling mechanisms. Immune activation alters central nervous system (CNS) and the CNS modulates immune function. During infection there are changes in complex behavior, including sleep. What is not well known is by what mechanisms, and where, in brain immune signals act to alter sleep. Cytokines, such as IL‐1, TNF and IL‐6 mediate infection‐induced alterations in sleep. Receptor signaling for these cytokines include Signal Transducer and Activator of Transcription 3 (STAT3). To determine a potential role in altered sleep during immune challenge, we injected LPS into several mouse strains and determined changes in STAT3 and cytokine in discrete brain regions.Adult male mice (C57BL/6J; Balb/c; TLR4 mutant; n = 3‐4 / strain / condition) were injected IP at light onset with either 0.2ml vehicle or 10μg LPS (E. coli serotype O111:B4). These animals were sacrificed 2‐ or 4 h post injection. STAT3 from 2 h treatments and cytokine from 4 h treatments were analyzed in brain and spleen using Bioplex assays.STAT3 protein increased from 4 ‐ 10 fold 2 h after LPS in all samples assayed from C57BL/6J mice and Balb/c mice. In these two mouse strains, IL‐1, TNF and IL‐6 increased from 2.5 ‐ 11 fold 4 h after LPS. In contrast, due to the defect in TLR4 a signaling transducer for LPS, there were no LPS‐induced increases in STAT3 or in cytokine protein in the TLR4 mutant mice.These results demonstrate that the STAT3 signaling pathway for proinflammatory cytokines may be activated in discrete mouse brain regions and suggests that these pathways play a role in transducing peripheral immune signals into alterations in CNS‐regulated sleep/behavior.
Roles of oxidative stress and ceramide (Cer) in cadmium (Cd) induced cell death of cultured kidney proximal tubule (PT) cells
Authors: Lee Wing‐Kee , Thevenod Frank
Published: June 2021

Cd, an environmental toxicant, induces reactive oxygen species (ROS) and apoptosis of kidney PT cells. We have previously shown that exposure of PT cells to 10 µM Cd for 6 h increases Cer‐dependent calpain activation and apoptosis (Am J Physiol Cell Physiol 293:839, 2007). Here we investigated how Cd‐induced ROS formation, Cer‐dependent calpain activation and mitochondrial function are linked in pro‐apoptotic signaling. Cell death was quantified by MTT assay or Hoe33342/EtBr nuclear staining. ROS were measured by oxidation of dihydrorhodamine 123 to rhodamine 123+. A luminescence assay was used for determining ATP. Cd (10‐100 µM) increased ROS as early as 0.5 h in a time and concentration dependent manner. This was unaffected by fumonisin B1, which inhibits de novo Cer synthesis, and calpain inhibitor PD 150606. But ATP production, used to measure mitochondrial function, was unaffected by 10‐50 µM Cd for 3‐6 h. Furthermore, synthetic C6‐Cer did not affect ATP levels.This suggests that calpains are a downstream target of ROS and de novo Cer synthesis in Cd apoptosis of PT cells. Moreover, the magnitude of ROS formation seems to determine whether Cd triggers apoptosis or necrosis. ROS formation is independent of mitochondrial dysfunction and may be the consequence of depletion of intracellular antioxidants and/or inhibition of free radical‐detoxifying enzymes. Funded by DFG TH 345/8‐1.
Establishing the molecular modulation of the inflammation by xanthohumol and its metabolites in endothelial and smooth muscle cells
Authors: Negrão Rita , Moura Liane , Soares Raquel
Published: June 2021

Vessel wall cells play relevant roles in inflammation. Xanthohumol (XN) and its metabolites isoxanthohumol (IXN) and 8‐prenylnaringenin (8PN) were described as anti‐inflammatory and anti‐angiogenic compounds. To understand the modulation of inflammation by these polyphenols in vessel walls, Human Umbilical Vein Endothelial Cells (HUVEC) and Human Aortic Smooth Muscle Cells (HASMC) were treated with 5‐10µM XN, IXN or 8PN for 24h. Expression profiles of angiogenic and inflammatory genes were examined by microarray assay. Genes involved in sprouting were down‐regulated by XN, IXN and increased by 8PN in HUVEC. Interleukin (IL)‐6 expression was increased in 8PN treatment. Conversely, HASMC increased TNFRSF12A after XN or 8PN incubation. XN and IXN downregulated IL‐12. Inflammatory responses in these cells were further evaluated measuring NO released (Griess reaction) and NFkB activity (ELISA) in cell nuclear extracts. A decrease in nitrite content was found for 8PN treatments. A reduction in NFkB activity was observed after treatment with XN and IXN, whereas 8PN incubation increased NFkB activity in both cell cultures.These findings reveal the distinct effects of these compounds in inflammation, providing clues to the development of useful therapeutic agents against inflammation‐ and angiogenesis‐associated pathologies.

Funded by ERAB (EA0641) and FCT (SFRM/BD/41888/2007)
Angiomotin isoforms are differentially affected by exercise training in skeletal muscles from lean and obese rats
Authors: BIROT Olivier , FORN Paul , ROUDIER Emilie
Published: June 2021

Angiomotin (Amot) was recently identified on the surface of endothelial cells, regulating their migration and thus angiogenesis. p80 Amot isoform is mostly expressed in the dynamic phase of angiogenesis when activated endothelial cells migrate, whereas p130 is more characteristic of stabilized vessels. Such observations were mainly obtained from studies on pathological angiogenesis and the physiological regulation of Amot in healthy tissues remains largely unknown.

Objectives

To study 1) whether Amot was physiologically expressed in skeletal muscle, 2) how physical activity, a pro‐angiogenic physiological stimulus in skeletal muscle, could regulate Amot expression, 3) if such regulation was altered in the context of obesity.

Methods

p80 and p130 expressions were measured in soleus and plantaris from sedentary and trained, lean or obese rats.

Results

Exercise training shifted Amot isoforms expression pattern toward an "angiogenic phenotype". However, such regulation was different between lean and obese rats. In lean animals, exercise training increased p80 expression, whereas in obese rats it reduced p130.

Conclusion

p80/p130 ratio could reflect the tissue angiogenic potential. Exercise shifted this Amot isoforms ratio toward an angiogenic phenotype by different mechanisms between lean and obese rats. This work was supported by the Natural Sciences and Engineering Research Council of Canada.
Involvement of NF‐kappaB in the Cross Talk Between the Renin‐Angiotensin System and Insulin Signaling in Skeletal Muscle in Burn Injury
Authors: Wayne Michelle Marie , Lepard Jacob , Benavides Jeshurun , West Lori Gail , Enderson Blaine , Daley Brian , Kasper Sherry Oden , Karlstad Michael
Published: June 2021

Upregulation of the renin angiotensin system (RAS) is involved in impaired insulin signaling and glucose intolerance in type 2 diabetes and burn injury. We showed that losartan, an AT1 receptor blocker, improved insulin signaling and glucose tolerance in burn‐injured rats. It has been shown that NF‐kappaB activation may play an important role in angiotensin II induced skeletal muscle insulin resistance. Our aim was to examine the possible mechanism of the cross talk between the RAS and insulin signaling systems in skeletal muscle in burn injury. To assess the involvement of NF‐kappaB, we measured the levels of IkappaB, an inhibitor of NF‐kappaB, in rectus abdominus muscle three days after sham or burn injury. A 30% body surface area burn was induced in male Sprague‐Dawley rats by immersion of the dorsum into 90C water for 15s. Losartan (30 mg/kg/day) or placebo (water) was given by gavage for three days post‐burn. The level of IkappaB decreased in burned rats given placebo but returned to sham placebo levels in burned rats given losartan. These data suggest that NF‐kappaB may be involved in the cross talk between the renin‐angiotensin system and insulin signaling in skeletal muscle in burn injured rats.
Activation of JG cell calcium sensing receptor inhibits renin release in part by activating different calcium channels
Authors: Ortiz‐Capisano M. Cecilia , Beierwaltes William H.
Published: June 2021

We have previously shown that renin containing juxtaglomerular (JG) cells express calcium sensing receptors (CaSR). When stimulated CaSR increase intracellular calcium (Ca) and decrease renin release. However, it is not clear what the source of Ca is. We hypothesized that JG CaSR activation opens both L‐type voltage gated and/or store‐operated Ca channels (SOC). We used primary cultures of JG cells isolated from C57 mice, plated at 70‐80% confluence for 48 hrs. Control cells released renin at 0.86±0.15 ?gAngI/hr/mg prot. The CaSR agonist, sensipar, reduced renin release to 0.43±0.01 μgAngI/hr/mg prot (p<0.05), a 50% reduction. In the presence of verapamil, an L‐type channel blocker, sensipar had no effect (0.81±0.18 μgAngI/hr/mg prot (p<0.05). In different experiments, basal renin release was 0.34±0.06 μgAngI/hr/mg prot, in control cells but only 0.22±0.04 μgAngI/hr/mg prot (p<0.05) in sensipar treated cells. In the presence of BTP2, a SOC blocker, sensipar had no significant effect (0.30 ±0.05µg AngI/hr/mg prot (p<0.05).We conclude that activation of the CaSR in JG cells results in increased intracellular Ca through integrating the response of different Ca channels, resulting in a decrease in renin release.
Enhancing Scientific Education through University‐High School Collaboration
Authors: Silver Kristopher , Dix Randy , Lillich James D. , Woods Teresa , Choma Kimathi , Freeman Lisa C.
Published: June 2021

The Olathe North Biotechnology project is a science initiative undertaken by the Kansas State University Olathe Innovation campus in conjunction with Olathe North High School to give high school students and teachers first hand experience with authentic laboratory research. Students are co‐mentored by University researchers and high school teachers to conduct experiments in the high school classroom. The program aims to increase student interest in science and technology, and to further the recruitment of students to the universities who support such initiatives. Teaching and coaching of high school students in scientific inquiry, experimental design, laboratory techniques, good laboratory practices, and presentation of results are also expected to enhance the abilities of university faculty and staff to communicate scientific principles to a wider public audience. Challenges and opportunities encountered in the course of this pilot program will be discussed.
Pericytes promote angiogenesis at the early stage of wound healing
Authors: Morikawa Shunichi , Ezaki Taichi
Published: June 2021

Recently, more and more attention has been focused on pericytes as a target of anti‐angiogenic therapy. In this study, we sought to determine whether they exist at the early stage of angiogenesis, and if they existed, determine how they function at this stage during wound healing. In wound tissue, NG2 proteoglycan and desmin immunoreactive pericytes were closely associated with newly forming blood vessels that contained endothelia with BrdU incorporated proliferative cell nuclei. These pericytes co‐expressed vascular endothelial growth factor ‐A (VEGF‐A). Association of pericytes on the migrating/sprouting endothelia with mitotic figure was also observed with transmission electron microscopy. Phenotypically, the pericytes in wound tissues had larger cell bodies and more euchromatic nuclei than the pericytes in normal vasculature, and expressed alpha smooth muscle actin in general, which is unusual phenomenon especially in normal capillary pericytes. These observations together indicate that the activated state of pericytes is essential for the angiogenesis at the early stage of wound healing.

We conclude that pericytes do exist at the early stage of the angiogenesis during wound healing to induce proliferation of endothelia and to guide their migration/sprouting via VEGF‐A secretion, though the generally accepted view suggests the absence or disappearance of pericytes at this stage of angiogenesis.