bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pat1 contains distinct functional domains that promote translational repression, P‐body assembly and activation of decapping
Authors: Pilkington Guy Robert , Nissan Tracy , Parker Roy 
Published: June 2021

The control of mRNA degradation and translation are important aspects of gene regulation. Recent results suggest that translation repression and mRNA decapping can be intertwined and involve the formation of a quiescent mRNP, which can accumulate in cytoplasmic foci referred to as P‐bodies. The Pat1 protein is a key component of this complex and an important activator of decapping yet little is known about its function. In this work we analyze Pat1 in Saccharomyces cerevisae function by deletion and functional analyses. Our results identify two primary functional domains in Pat1, one promotes translation repression and P‐body assembly, and a second domain promoting mRNA decapping after assembly of the mRNA into a P‐body mRNP. In addition, we provide evidence that Pat1 binds RNA and has numerous domain specific interactions with mRNA decapping factors. These results indicate that Pat1 is an RNA binding protein and a multi‐domain protein that functions at multiple stages in the process of translation repression and mRNA decapping. Current experiments are directed at understanding the mechanism by which Pat1 affects translation repression and possible roles for nuclear‐cytoplasmic shuttling of Pat1.NIH grant (R37 GM45443) and funds from the Howard Hughes Medical Institute supported this work.
Function and Regulation of Plasma Glutathione Peroxidase
Authors: Ottaviano Filomena G. , Handy Diane E. , Loscalzo Joseph 
Published: June 2021

GPx‐3 is a selenocysteine‐containing protein that catalyzes the reduction of hydrogen peroxide and lipid hydroperoxides using glutathione as a reducing agent (GSH). Our goals are to overexpress GPx‐3, determine its activity, and study its regulation. The complex expression of selenoproteins requires specific translational cofactors (SBP2, SelD, and tRNASec), adequate selenium, and the selenocysteine insertion sequence (SECIS), which facilitate read‐through of the UGA codon for selenocysteine (Sec) and incorporation in the growing polypeptide. Stable Cos 7 cell lines of GPx‐3 cDNA/SECIS, His/V5 tagged wild type, SECIS containing mutated 3'UTR fragments, and a Sec → Cys mutant were generated and grown in medium with adequate sodium selenite. Purification was accomplished by immobilized metal ion affinity chromatography with nickel Sepharose that binds GPx‐3 His tagged protein, and followed by Western blot using an anti‐V5 antibody, and by His‐tag ELISA. The mRNA stability of both the wild type and Cys mutant were examined by Real‐Time PCR. Translation of the wild type GPx‐3 was much less efficient than that of the Cys mutant. Mass spectrometry confirmed GPx‐3 identity. The 3' UTR of GPx‐3 is important in regulating its mRNA stability and protein expression.Support: HL61795, HV28718, and HL81857
Hypoxic HK2 Gene Regulation Involves Multiple Distinct Cis‐Acting Elements That Differ In Their Hypoxia‐Inducible Factor‐α (HIFα) Isoform Selectivity
Authors: Robey R. Brooks , Zhong Lihui , Keyes Lauren , Montes Jessica , Zhang Hongmei , Granner Daryl , Printz Richard 
Published: June 2021

As the only effective energy substrate in the absence of O2, glucose (Glc) is central to all cellular strategies for hypoxic adaptation. Obligatory reliance on Glc also explains associated induction of glycolytic enzymes such as hexokinases which catalyze the first committed step of Glc metabolism. HIF1α contributes to HK2 expression in cancer cells, but the specific cis‐acting sequences are undefined and corresponding effects in nontransformed cells are unexplored. We therefore used chimeric reporter genes to delineate hypoxia‐responsive cis‐acting HK2 promoter regions in nontransformed NRK‐52E cells.Major hypoxic control of HK2 expression mapped to a phylogenetically conserved tandem pair of canonical HIF‐binding motifs just 5' to the 157 bp basal promoter region. Targeted mutagenesis of either motif abrogated hypoxia‐responsiveness, as did their spatial separation by a half (+5 bp) ‐ but not a full (+10 bp) ‐ helical turn. Similar results with hypoxia‐mimetics (e.g. CoCl2) and stabilized mutants of HIF1α ‐ but not HIF2α ‐ suggest HIF1α selectivity. Independent hypoxic enhancer activity responsive to both HIF1α and HIF2α ‐ but not other known HK2 transcriptional regulators ‐ was also observed within 90 bp of the transcription start site. These results suggest complex hypoxic gene regulation involving both combinatorial interactions and cis‐acting elements with differing HIFα isoform specificities.
Nox‐4 siRNA Causes Attenuation of Hypoxic Pulmonary Vasoconstriction in Bovine Pulmonary Arteries
Authors: Ahmad Mansoor , Kelly Melissa R , Kandhi Sharath , Zhao Xiangmin , Wolin Michael S 
Published: June 2021

Hypoxic pulmonary vasoconstriction (HPV) in endothelium removed bovine pulmonary arteries (BPA) is potentially mediated through the removal of a superoxide‐derived hydrogen peroxide mediated basal relaxation. To study the source of the superoxide, endothelium removed BPA rings were cultured for 48 hrs with the first 24 in the presence of either Nox‐4 or Nox‐2 siRNA. Nox‐4 siRNA caused a significant decrease in Nox‐4 expression without any effect on Nox‐2 levels. Superoxide levels and HPV were significantly reduced in BPA rings treated with Nox‐4 siRNA without affecting force development to KCl. Superoxide levels were significantly reduced with Nox‐2 siRNA treatment however, HPV and KCl force were not affected. Endothelium removed BPA rings treated with apocynin and gp91‐dstat show a decrease in superoxide levels but did not affect either KCl force or HPV. Thus Nox‐4 and not Nox‐2 may be the source for the potential superoxide derived peroxide mechanism maintaining basal relaxation during normoxia which when removed leads to HPV.Support by NIH grants HL31069, HL43023 and HL66331.
Reactive oxygen and nitrogen species in leukocyte adhesion and transmigration: a computational model
Authors: Lakshmanan Nisha , Kavdia Mahendra 
Published: June 2021

In hyperglycemia, there is a significant increase in the levels of tyrosine nitration causing an increase in circulating adhesion molecules. This leads to a greater number of leukocytes that roll and adhere on the vascular endothelium resulting in endothelial cell dysfunction. Some of the adhered leukocytes also cross the endothelial junction barrier and migrate from the lumen to the surrounding spaces. Inducible nitric oxide synthase in these leukocytes produces nitric oxide and superoxide, thereby producing more of peroxynitrite and nitrotyrosine. To better understand this vicious cycle, we formulated a mathematical model of a tissue containing a blood vessel and simulated varying degrees of leukocyte adhesion and transmigration. The model predicts an increase in the peak levels of nitric oxide, superoxide and peroxynitrite at and around the site of adhesion; from 83, 2 and 3.5 nM respectively, in the case of no adhesion to 104, 13.5 and 35 nM when leukocytes adhere. However, the extent of transport is a few microns for superoxide to 10's of microns for peroxynitrite. Results indicate that peroxynitrite can cause tissue injury over a wide area across the adhesion site and trigger further leukocyte adhesion. The model helps elucidate some important aspects of complex leukocyte‐endothelium interactions such as signaling, injury and adhesive response.Supported by: AHA 0530050N and NIH R01 HL084337 & R15 HL087287.
Effect of viscosity, protein and dietary fibre in beverages on perceived satiety
Authors: Lyly Marika , Ohls Nora , Salmenkallio‐Marttila Marjatta , Lähteenmäki Liisa , Liukkonen Kirsi‐Helena , Poutanen Kaisa 
Published: June 2021

The intake of dietary fibre and protein has been linked with increased satiety and weight management. The aim of this study was to investigate the effect of viscosity, dietary fibre and protein on perceived satiety in beverages. Two different levels of carboxymethyl celluloce (CMC), (0 and 5 g); and two levels of whey protein (0 and 20 g) at energy level 700 kJ were used. The dietary fibre was either high‐viscosity CMC or low‐viscosity CMC. Satiety‐related perceptions of 29 healthy volunteers were measured with line scales for 3 hours after ingesting a sample. The area under curve (AUC; cm*min) was calculated.Dietary fibre and whey protein increased perceived satiety significantly and independently. The sample containing both dietary fibre and whey protein had the greatest effect on perceived satiety. Higher viscosity showed a tendency to increase satiety compared to the samples with lower viscosity (p=0.091). Dietary fibre and protein in beverages have thus potential to affect weight management.TEKES (Finnish Funding Agency for Technology and Innovation) partly funded this research.
Sex Dimorphism of Systolic Blood Pressure and Proteinuria during High Salt Intake in Ang II‐dependent Hypertension
Authors: Planchard Jeffrey A , Lowenburg Benjamin M , Martin Victoria L , Botros Fady T , Prieto Minolfa C 
Published: June 2021

Salt intake inhibits the renin angiotensin system (RAS), but when angiotensin II (AngII) levels are not suppressed, increased salt intake exacerbates hypertension and renal injury. We determined whether the pressor response to AngII and associated kidney injury exhibit sex differences during high salt (HS) intake and endogenous RAS blockade. In this study, 35 Sprague‐Dawley rats: [1) Sham+HS [male n=5; female n=4]; 2) AngII [male n=3; female n=3] 3) AngII+HS [male n=5; female n=5]; 4) AngII+HS+LOS [male n=5; female n=5], were infused with AngII (80ng/min; 14 days), fed with HS diet (8% NaCl), and treated with losartan (LOS, 30 mg/L). Systolic blood pressure (SBP) baseline was not different between males and females (116±3 vs.119±2 mmHg) or after 2‐weeks of AngII infusions (228±9vs.217±20 mmHg). Addition of HS diet did not modify the SBP (228±13 vs.211±16 mmHg). LOS similarly ameliorated the increases in SBP in both genders (156±15 vs.157±10 mmHg). HS intake increased proteinuria in AngII‐infused rats (48±5vs.19±6 mg/day) and augmented progressively with a greater increase in males than females (79±6 vs.47±6 mg/day). The proteinuria in female rats was ameliorated by LOS. Salt sensitivity of SBP does not exhibit sexual dimorphism, however the augmented proteinuria in male rats may reflect a greater degree of renal injury than in female rats.Support from Tulane‐BIRCWH and Merck & Co., Inc.
Cardiovascular and Renal Responses Produced by the Central Microinjection of Salvinorin A in Ketamine/Xylaxine‐Anesthetized Rats
Authors: Gottlieb Helmut B , Ji Lisa , Cunningham JT 
Published: June 2021

One of active ingredients of Salvia divinorum, Salvinorin A (Sal A), has been shown to be a kappa opioid receptor agonist. The activation of central kappa opioid systems markedly affects renal function (water diuresis) in a manner that is different from any clinically used diuretic to date. The cardiovascular and renal effects produced by central administration of Salvinorin A are yet to be determined.MethodsSprague‐Dawley rats were implanted with chronic arterial, venous and bladder cannulas and infused with isotonic saline (55 ml/min, iv) containing ketamine (1 mg/Kg/min) and xylazine (80 mg/Kg/min). After equilibration, urine was collected during two control periods (C, 10‐min ea) and immediately after ICV Salvinorin A (10 nmol or 30 nmol) for 80 min (10‐min ea). Controls received injections of vehicle (DMSO) into the lateral ventricle (n=6).ResultsICV injection of Salvinorin A markedly increased V without significantly changing UNaV or blood pressure.ConclusionIn anesthetized rats, Salvinorin A selectively affected urine output (diuresis), whereas the activation of central kappa receptors U‐50488H affects both urine flow and UNaV. From these studies, it is apparent that Salvinorin A's effects on renal differ from those elicited by central kappa agonists (endogenous and synthetic). Supported by HL62579 and NIH EARDA grant.
Dietary Quality is not Determined by Children's Willingness to Try F&V.
Authors: Onufrak Steve , McCabe‐Sellers Beverly , Lovera Dalia , Bogle Margaret 
Published: June 2021

IntroductionFruit and vegetable (F&V) consumption is generally inadequate among children and lack of willingness to try F&V is often cited as a reason for this. We examined whether dietary quality and F&V consumption differed according to children's objectively measured willingness to try F&V.MethodsResearch was conducted at a summer day camp program in Marvell, AR attended by 84 AA children ages 5‐12. Dietary quality was measured using Healthy Eating Index‐2005 (HEI‐05) components based upon 24‐hour recalls. Children were offered a variety of F&V items as an afternoon snack over 6 weeks. Willingness to try an item was defined as consumption of 20% of item weight. Children who tried at 75% of F&V items offered were classified as "triers".ResultsThe mean number of F&V offered was 16.7 (range 1 to 27). Overall HEI‐05 did not differ by trier status (Mean HEI 44.1 for triers, 45.6 for non‐triers, p=0.56). No differences were observed between F&V triers and non‐triers for HEI‐05 component scores for total fruit (1.6 vs. 2.2, p=0.18), whole fruit (1.2 vs. 0.9, p=0.51), total vegetables (2.2 vs. 2.0, p=0.60), or dark green and orange vegetables (0.3 vs. 0.7, p=0.16).ConclusionUnwillingness to try new F&V items was not associated with overall dietary quality or F&V consumption. Low consumption of F&V observed among children may be related to inadequate exposure and availability rather than lack of willingness to try them.
Association between physical activity, insulin resistance, body fat, and leptin in patients after gastric bypass surgery, obese, and non‐obese controls
Authors: Ramirez‐Marrero Farah A , Somaraju Madhuri , Vaa Brianna E , Roberts Shelly K , Joyner Michael J , Miles John , Curry Timothy B 
Published: June 2021

Physical activity (PA) is inversely related with body fat, insulin resistance (IR), and leptin. However, these associations are not clear in patients after gastric bypass surgery (GBS). We hypothesized an inverse relation between PA, BMI, IR, and leptin; and a positive relation between leptin, BMI, and IR in a group of 9 patients after GBS, 8 obese (Ob), and 7 non‐obese (N‐Ob) controls (age=39.0±5.7, 27.7±6.9, 28.0±10.2 yr, respectively). Subjects wore an accelerometer from 6‐7 days, and underwent measurements of height, weight, DEXA, blood glucose, insulin and leptin. IR was estimated using HOMA. Between group differences in PA, BMI, IR, and leptin were determined with ANOVA; and the relation between these variables was determined with simple linear regressions. Between group differences were observed for BMI (Ob=38.7±1.6, GBS=30.4±1.5, N‐Ob=23.8±1.7 kg/m2), IR (Ob=3.0±0.5, GBS=1.1±0.5, N‐Ob=0.7±0.5), and leptin (Ob=55.9, GBS=28.7±4.5, N‐Ob=5.1±5.6 ng/ml). PA was not different between groups. Inverse associations were observed between PA and BMI (r= ‐ 0.55), and leptin (r= ‐ 0.56); and positive associations were observed between leptin and BMI (r= 0.92), and IR (r= 0.63). PA appears to be associated with the control of obesity and IR possibly via reductions in leptin, a mechanism that requires further study.Funded by NIH CTSA UL1‐RR24150, NIH CTSA KL2‐RR024151
Interleukin‐1β (IL‐1β) induced formation of embryoid body (EB)‐like structures in human term placenta derived stem cells
Authors: Strakova Zuzana , Reed Jennifer 
Published: June 2021

Interleukin‐1 β (IL‐1 β) induced formation of embryoid body (EB)‐like structures in human term placenta derived stem cellsHuman decidua parietalis placenta stem cells (hdpPSC) display pluripotency markers and are able to differentiate into mesenchymal lineages (osteoblasts, adipocytes, chondrocytes) as well as decidual cells (Strakova Z. et al., Cell Tissue Res 332:479, 2008). Moreover, hdpPSC express a basic marker for the endoderm, α‐fetoprotein, as well as nestin, a marker for neural/progenitor cells, suggesting the potential to differentiate into all three germ layers. Exposure (12‐40 days) to a stimulus mimicking an embryonic signal for decidualization (the cytokine IL‐1β with estradiol‐17β and medroxyprogesterone acetate) induced the formation of net‐like structures with dense cell aggregates. Round discrete conglomerates appear similar to EB structures described during the differentiation of embryonic stem cells. Continued growth resulted in a cystic appearance (200‐827 βm). Immunodetection of EB‐like structures showed retention of pluripotency markers SSEA‐4 and Oct‐4. Intensive cofilin staining confirmed the active reorganization of actin. The fixed specimen displayed simple mesodermal tissue morphology. It was positive for vimentin and α‐SMA and negative for α‐fetoprotein and cytokeratin. However, strong positivity for nestin in EB‐like structures confirms the early progenitor status of the cells and suggests the potential of these easily available cells as an alternative source of human stem cells.
Influence of a Negative Hydrostatic Column and Central Fluid Shift via ‐6° Head‐down Tilt Posture on Cardiovascular Performance
Authors: Ade Carl J , Harms Craig A , Musch Tim I , Barstow Tomas J 
Published: June 2021

AimsTo examine the influence of a negative hydrostatic column via ‐6° head‐down tilt (HDT) exercise on cardiovascular performance and to determine if the HDT posture stimulates greater cardiovascular adaptations during exercise training compared to upright (UPR).Methods9 males (21±2 yrs) performed VO2peak cycle exercise tests in the UPR, supine (SUP), and HDT positions. 9 different males (20±2 yrs) were endurance trained on a cycle ergometer in the UPR position for 8 wks (UPRTN) or in the UPR position for 4 wks followed by 4 wks in the HDT position (HDTTN).ResultsDuring acute exercise, VO2peak was decreased in the SUP and HDT positions compared to the UPR (2.01±0.46, 2.01±0.51 vs. 2.32±0.61 L/min respectively, P < 0.05). Stroke volume (SV) at 100 watts was greater in the HDT position compared to the UPR (77±5 vs 71±4 ml/beat, P < 0.05). Following training SV at 100 watts increased from 77±1 to 85±9 ml/beat in the HDTTN group during UPR exercise (P < 0.05). In addition, SV increased from 76±10 to 85±16 ml/beat in the HDT position for the same individuals (P < 0.05). SV in the UPRTN during 100 watts in the HDT position was unchanged but increased during UPR exercise following 8wks of training (65±3 to 75±5 ml/beat, P = 0.21).ConclusionsHDT exercise increases sub‐maximal SV compared to UPR exercise. Training in the HDT position induces cardiovascular adaptations in both UPR and HDT exercise that are not achieved with UPR training.
Prediction of Changes in Orthostatic Tolerance after Head down Bed Rest With and Without Artificial gravity Training
Authors: Evans Joyce McClendon , Meng Martha , Patwardhan Abjihit , Stenger Michael , Feiveson Alan , Knapp Charles 
Published: June 2021

In a recent study to evaluate the potential for artificial gravity (AG) to counteract spaceflight‐induced cardiovascular deconditioning, 8 men received a daily, one hour dose of AG (2.5 Gz ) while 7 underwent no countermeasure, during 21 days of head down bed rest (HDBR).ResultsAfter bed rest, AG‐treated subjects demonstrated greater orthostatic tolerance (OT) than control subjects, p = 0.012 (Stenger, 2008). Variables recorded during HDBR days were then analyzed to develop a model to predict OT before return to gravity. The variables evaluated represent control aspects of heart rate, blood pressure, spontaneous baroreflex activity, and breathing activity. From 16 available variables, 120 combinations were used to build a two variable model. The combination of high frequency spectral power of systolic blood pressure and mean blood pressure correctly classified subjects as trained or untrained 93% of the time. Predictive potential of this classifier was verified by bootstrap analysis.ConclusionsOur data support the hypothesis that AG treatment lessens cardiovascular deconditioning in bed rested men. In addition, differences in AG treated and control subjects can be discriminated by a combination of variables related to regulation of blood pressure. This same combination of variables may be able to predict OT upon return from space. Supported by NASA AG‐Bed Rest Project (IMAG Pilot Study).
Cardiovascular Regulation During Artificial Gravity Stress
Authors: Evans Joyce McClendon , Ayanampudi Vijaya , Howarth Mark , Moore Fritz , Patwardhan Abjihit , Knapp Charles 
Published: June 2021

Physiological deconditioning of astronauts returning from space may be lessened by inflight centrifuge usage. We assessed radius of rotation, G level and exercise components of an artificial gravity (AG) countermeasure for future use in preventing weightlessness‐induced cardiovascular deconditioning. 12 healthy, ambulatory men (35 ± 9 y, 83 ± 8 kg) underwent 4 AG and 1 earth gravity protocols that varied g level, radius of rotation and level of preexercise.Radius and G level effectsMean heart rate (HR) and sympathetic control of HR (Spectral power LF/HF of RR Interval) increased with increasing G level and radius.Exercise effectsMHR increased with exercise and exercise prevented increased LF/HF and decreased HF/ (LF+HF) that occurred during the same protocol with no exercise.Protocol duration effectsThe sympathetic index increased, and parasympathetic index decreased, across the protocols.CONCLUSIONSRadius of rotation had the greatest effect on autonomic balance, while exercise had its greatest effect on mean HR. Autonomic balance shifted toward sympathetic dominance during centrifugation and this effect was lessened by exercise. Results support the idea that short radius AG plus exercise may provide an effective countermeasure to space flight deconditioning that may be more effective in preserving orthostatic tolerance than current countermeasures. Supported by KY NASA EPSCoR WKU62611, NASA Ames.
Liver Specific Ablation of Integrin Linked Kinase in Mice Results in Enhanced and Prolonged cell proliferation After Phenobarbital Administration
Authors: Donthamsetty Shashikiran , Vishakha Bhave , Bell Aaron , Mars Wendy , Yang Yu , Orr Anne , Bowen William , Michalopoulos George 
Published: June 2021

This study investigates the role of ILK in hepatocyte proliferation induced by Phenobarbital (PB). WT (wild type) and ILK‐/‐ mice were given PB( 0.1% in drinking water) for 10 days. Livers were harvested on 2, 5 and 10 day during PB administration. In the ILK‐/‐ mice the liver/body weight ratio was more than double as compared to 0h at day 2 and 5 while at day 10 it was thrice. In the WT mice the increase was not dramatic and seems to have leveled off after day 2. There were slightly increased PCNA positive cells in the ILK‐/‐ animals at day 2 as compared to WT after PB administration. In the WT animals the proliferative response had come back to normal by day 5 and 10 but the ILK‐/‐ mice still had PCNA positive cells at day 5 and 10 suggesting a prolonged proliferative response. ILK‐/‐ mice also showed increased expression of key genes involved in hepatocyte proliferation at different time points during PB administration. In summarize, ECM proteins communicate with the signaling machinery of dividing cells via ILK to regulate hepatocyte proliferation and termination of the proliferative response. Lack of ILK in the hepatocytes have prolonged proliferative response to a mitogenic stimuli suggesting defect termination of proliferative response.The work is supported by a R01 grant (5R01CA035373‐26) titled "HGF in Liver Development, Regeneration and Neoplasia"