bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diaphragm Contractile Function Differs Among Murine Strains
Authors: Stasko Shawn , Reid Michael B 
Published: June 2021

Murine diaphragm fiber bundles are routinely used to study physiologic properties of skeletal muscle. Based on pilot data, we hypothesized that contractile function differs among strains in healthy mice.MethodsWe measured specific force (N/cm2) and fatigue characteristics in diaphragm fiber bundles from age‐matched male ICR, C57BL/6, and DBA‐1 mice. Fiber bundles were studied in vitro (optimal length, 37°C, n=4/group) using a standard force‐frequency protocol (1, 15, 30, 50, 80, 120, 180, 250, 300 Hz). Fatigue was induced using repeated submaximal tetanic contractions (40 Hz, 500 ms trains; 0.5 trains/s) for 5 min.ResultsAmong groups, ICR muscle generated higher maximal forces (26.4 N/cm2 ± 0.3 SE) than C57BL/6 (21.1 ± 0.3) or DBA (14.7 ± 0.2). Relative force (as % maximal) did not differ among groups at any stimulus frequency. During the fatigue protocol, force fell less in DBA muscle (5.9 to 3.0 N/cm2; −50% decrement) than ICR (8.8 to 2.7; −69%) or C57BL/6 (8.3 to 3.0; −69%).ConclusionSpecific force and fatigue characteristics differ among diaphragm fiber bundles of ICR, C57BL/6, and DBA‐1 mice.SummaryThese data suggest that diaphragm contractile properties differ among murine strains. Supported by NIH grant HL08341 (T32 training fellowship).
Genome‐Wide P‐element Screen for Hypoxia Tolerance Genes in Drosophila melanogaster
Authors: Haddad Gabriel G. , Azad Priti 
Published: June 2021

Hypoxia occurs during normal conditions (high altitude) or during pathologic states (sickle cell anemia). Our research is focused on understanding the molecular mechanisms that lead to injury or adaptation to hypoxic stress using Drosophila as a model system. To identify the genes involved in hypoxia tolerance, we screened P‐element insertion lines generated by Gene Disruption Project. For hypoxia tolerance, we screened for a) eclosion rates after following the development of embryos placed in 5% O2 to eclosion and adulthood, b) number of adult flies surviving after eclosion. Out of 2367 lines screened, 44 P‐element lines had eclosion rates significantly higher (>70% eclosion) than the controls (eclosion rate ~7–8%) under hypoxia. The molecular function of these lines ranged from cell cycle regulation, DNA or protein binding, ATPase activity, and transcriptional co‐regulators. In this screen, we found certain interesting candidate genes such as sec8, cyclin E, osa, l(3)mbn, lqf which show tremendous hypoxia tolerance during all stages of the developmental cycle. Furthermore, we employed the UAS–Gal4 system to further dissect the role of these genes ubiquitously or in specific tissues in vivo. Interestingly, we found that regulation by single genes, such as osa can play an important role in survival and development during hypoxia.This work has been supported by NIH grant (RO1 NS037756) to Dr. Gabriel Haddad.
Coordinated microRNA/gene networks central to nutrient responsiveness in the 0.9G baboon fetal kidney
Authors: Cox Laura A , Glenn Jeremy P , Lange Kenneth P , Nijland Mark J 
Published: June 2021

MicroRNAs are environmentally sensitive gene regulators that play roles in proliferation and differentiation. We hypothesized that miRNAs underlie fetal baboon kidney transcriptome response to nutrient restriction (NR) via coordinated miRNA/gene networks. We used in silico methods to identify NR sensitive miRNAs in fetal kidneys.Differentially expressed genes from 0.9G baboon kidney [CTR, n=3;NR, n=3,70%CTR] were assessed for miRNAs with TargetScan based ID by: genomic location congruency; enrichment analysis; and network analysis to ID hub genes and networks predicted to be regulated by miRNAs.Genomic location congruency identified 145 miRNA families; enrichment analysis ranked 55 families; network analysis revealed 7 families with target sites in 3 or more hub genes. The mir‐27 family has target sites in 7 hub genes and 35 network genes, many transcription factors and all down regulated in NR.Only network analysis provided a directed approach to selecting miRNAs that may coordinately regulate gene expression. Results suggest that miRNAs regulate NR responsiveness in renal development via transcription factors and reveal potential transcriptome/epigenome interactions fundamental to renal development.
Bicarbonate‐dependent chloride transport drives fluid secretion by the human airway epithelial cell line Calu‐3
Authors: Shan Jiajie , Liao Jie , Huang Junwei , Robert Renaud , Palmer Melissa L. , Fahrenkrug Scott C. , O'Grady Scott M. , Hanrahan John W. 
Published: June 2021

Anion transport by the airway is defective in cystic fibrosis (CF), but its mechanisms and roles in fluid secretion are not well understood. We studied Cl− and HCO3− fluxes across Calu‐3 cells, calculated the equivalent short‐circuit current (Ieq) under open circuit conditions, and measured fluid secretion by monolayers.Forskolin stimulated Ieq, JHCO3− and fluid secretion. Bumetanide reduced secretion by ~20%, but had no effect on HCO3− transport. Although secretion was abolished in Na+‐free or HCO3−‐free solution, significant JHCO3− was maintained in Cl−‐free solution. DIDS was inhibitory in normal and Cl−‐free solutions. Using apical permeabilization we demonstrated an exchange of intracellular HCO3− for basolateral Cl− or NO3−, but not for gluconate. Adding basolateral NO3− to low‐Cl− medium restored fluid secretion. Acetazolamide greatly inhibited anion transport.Our data show that basolateral anion exchange plays an important role in Cl− loading and fluid secretion. NBC mediates HCO3− entry and carbonic anhydrase contributes significantly to the intracellular accumulation of HCO3−. Although HCO3− is essential for fluid secretion, most HCO3− is recycled to the basolateral side in exchange for Cl−, thus fluid transport depends mainly on JCl− rather than JHCO3−. HCO3− secretion persists in Cl−‐free solution and is sensitive to CFTR blockers, suggesting apical HCO3− exit is mediated by CFTR.
Sorting protein‐related receptor SorLA is involved in regulation of renal Na+‐K+‐2Cl‐cotransporter through interaction with an isoform of calcineurin phosphatase
Authors: Borschewski Aljona , Willnow Thomas , Dathe Christin , Paliege Alexander , Ferreri Nicholas , Bachmann Sebastian , Mutig Kerim 
Published: June 2021

Activity of the Na+‐K+‐2Cl‐cotransporter (NKCC2) of the thick ascending limb (TAL) is dependent on its N‐terminal phosphorylation. Sorting protein‐related receptor SorLA was shown to facilitate this process. To clarify the interference between SorLA and NKCC2 we have evaluated the profile of relevant kinases and phosphatases in TAL of SorLA‐deficient (Sorla−/−) compared to wild‐type (WT) mice.SorLA‐deficiency was associated with nearly absent NKCC2 phosphorylation (−97%). Levels of the SPAK‐OSR1 kinases were not changed while the abundance of the calcineurin phosphatase PP2BAβ was significantly increased in SorLA‐deficiencient animals (+201%). Confocal analysis revealed apical accumulation of the phosphatase in TAL of Sorla−/− mice. The interaction of NKCC2 with PP2BAβ was verified by co‐immunoprecipitation. Application of a calcineurin inhibitor cyclosporine in cultured TAL cells induced an increase of NKCC2 phosphorylation.Our results establish PP2BAβ as a relevant phosphatase responsible for the dephosphorylation of NKCC2 and provide evidence that SorLA may mediate degradation of PP2BAβ thus facilitating the phosphorylation of the transporter.
E2F1 is a potential novel regulator of liver fibrosis by targeting Egr‐1 through nuclear receptor SHP
Authors: zhang yuxia , wang li 
Published: June 2021

ObjectiveEgr‐1 is a critical regulator of liver fibrosis. However, the transcriptional network that governs Egr‐1 expression remains largely unknown. This study aimed at identifying novel transcriptional factors controlling Egr‐1 expression and liver fibrosis.MethodsLuciferase reporter and ChIP assays were used to elucidate the mechanisms. Mouse models of liver fibrosis induced by bile‐duct ligation (BDL), CCl4, or 3,5‐diethoxycarbonyl‐1,4‐dihydrocollidine were used as in vivo models.ResultsThe SHP‐/‐ mice showed increased fibrosis in response to BDL, which was reversed in hepatocyte SHP‐overexpressed mice. The Egr‐1 promoter was activated by E2F1, and the activation was abrogated by co‐expression of SHP and EID1 in both human hepatoma Huh7 and stellate cells LX2. ChIP assays confirmed the association of E2F1 and SHP with the Egr‐1 promoter, and GST pull‐down confirmed a direct interaction between E2F1 and SHP. Interestingly, the loss of E2F1 had no effect in CCl4‐intoxicated mice, but significantly decreased liver fibrosis of the biliary type. Importantly, E2F1 and Egr‐1 expression were dramatically increased in human cirrhotic liver, which was inversely correlated with diminished SHP expression.ConclusionsEgr‐1 expression is regulated by a transcription network involving E2F1 and SHP. E2F1 may function as a novel fibrogenic gene. Supported by T32CA092347 (Y.Z) and DK080440 (L.W).
Secondary lymphoid organs and CCR7 are dispensable for intestinal Th17 and Foxp3+ Treg cell differentiation
Authors: Geem Duke , Medina Oscar , Kim Wooki , Huang Clifton , Newberry Rodney , Denning Timothy Luke 
Published: June 2021

The intestinal immune system maintains homeostasis by promoting tolerance to the microbiota and food antigens while mounting inflammatory responses towards pathogens. Effector and Foxp3+ Treg cells are enriched in the intestinal lamina propria (LP) and are believed to be generated in the mesenteric lymph nodes (mLN) upon instruction by migrating CCR7+ LP dendritic cells. Herein, we demonstrate using multi‐color flow cytometry normal frequencies and cell numbers of Th17 cells and functional Foxp3+ Treg cells in the intestinal LP of mice deficient in lymphotoxin (LT)α, LTβR, and CCR7. In the absence of secondary lymphoid organs due to LTα deficiency, CD4+ T cell differentiation was not simply shifted to the spleen since splenectomized LTα‐deficient mice exhibited no defects in intestinal Th17 or Foxp3+ Treg cells. Using an OT‐II adoptive transfer system, naïve OT‐II CD4+ T cells differentiated into induced Foxp3+ Treg cells in the intestine in response to the feeding of ovalbumin to LTα‐deficient mice. Collectively, these data suggest that secondary lymphoid organs including mLN are not required for the differentiation of resident intestinal Th17 and Foxp3+ Treg cells and implicate the intestinal LP as a potentially important site for this process.Supported by NIH grants (AA01787001, AI083554), Career Development Award from CCFA, and Emory Egleston Children's Research Center seed grant to T.L.D.
Absence of microRNA‐155 protects against pressure overload‐induced cardiac inflammation and failure
Authors: Schroen Blanche , Corsten Maarten , Janssen Ben J , Creemers Esther E , Pinto Yigal M , Zacchigna Serena , Giacca Mauro , vigorito elena , Thum Thomas , carmeliet peter , Mayr Manuel , de Windt Leon , Lutgens Esther , de Winther Menno , Papageorgiou Anna , Heymans Stephane 
Published: June 2021

Cardiac hypertrophy, accompanied by progressive inflammation, and consequent heart failure (HF) continue to burden Western society. We show that miR‐155, a microRNA expressed by cardiac macrophages, stimulates the secretion of pro‐hypertrophic and ‐ inflammatory factors by macrophages and thereby causes adverse inflammation and HF.We subjected miR‐155 knockout (KO), wild type (WT) and antagomiR‐treated mice to pressure overload by angiotensin II or transverse aortic constriction to induce cardiac hypertrophy, inflammation and failure. Absence of miR‐155 inhibited the cardiac hypertrophic response and hampered cardiac macrophage activity. Bone marrow transplantation with miR‐155 KO and WT mice confirmed that miR‐155 in the macrophage mediates cardiac hypertrophy. It does so by repressing its direct target Suppressor of Cytokine Signalling‐1, leading to increased cytokine secretion and STAT3 activity, both implicated in cardiac inflammation and hypertrophy.These findings demonstrate the causative relation between inflammatory signalling and HF, and implicate microRNA‐155 as a therapeutic target in heart failure.
Detection and quantification of 7,12‐dimethylbenzanthracene (DMBA) in the liver and adipose tissue by HPLC
Authors: Jesus Patricia , Gonçalves Nuno , Costa Joana , Pereira Felipe , Pereira Mariette , Cabrita Silvério 
Published: June 2021

DMBA is an environmental pollutant present in cigarette smoke, automobile exhaust, grilled food, woodsmoke, etc[1]. It is the one of the most potent carcinogenic polycyclic aromatic hydrocarbons, can induce in experimental animals not only skin tumors, but also lung and mammary cancers[2]. The objective of this study is the morphological and molecular evaluation in the experimental administration of 7,12‐dimetilbenzantraceno (DMBA). These evaluations were performed in liver and adipose tissue because the toxic is metabolized in the liver and appear to accumulate in adipose tissue.Ten Wistar male rats, 8 weeks old were submitted to a quarantine period of one week, and then distributed by two groups: the test group, submitted to the oral administration of DMBA 20mg/kg/day, three times a week (Monday, Wednesday and Friday), for four weeks and the control group, kept on the standard conditions.The results of this study, lead us to think that DMBA can become stored on the adipose tissue, with a correlation with the concentration on the liver.
Enabling Xenopus oocytes and embryos to perform RNAi
Authors: Sheets Michael , Lund Elsebet , Imboden Susanne Blaser , Dahlberg James 
Published: June 2021

Although Xenopus laevis is a powerful model organism that has provided critical mechanistic insights into vertebrate development, cell biology and neural biology its utility has been limited by a lack of genetic analysis and gene manipulation. Other organisms that are difficult to manipulate genetically have often been studied by the use of RNAi, the inactivation of specific genes through the use of small interfering RNAs (siRNAs) that target the mRNAs of these genes for degradation. However, RNAi does not work in Xenopus oocytes or early embryos, making it impossible to use siRNAs in the analysis of early stages of Xenopus development. Thus new methods or tools that would support the study of these events are greatly needed.Recently, we discovered that Xenopus oocytes and early embryos lack functional Ago2, the nuclease containing protein that is guided to targeted mRNAs by siRNAs, which would explain why these cells are unable to carry out RNAi. Fortunately, we have also found that exogenous Ago2 generated from injected in vitro synthesized mRNA overcomes this deficiency. Thus we can now perform RNAi in Xenopus oocytes and early embryos, potentially making them amenable to genetic analysis through inactivation of specific gene products.
Formative research to inform the development of a community‐based intervention for chronic disease prevention in Guatemalan school‐age children
Authors: Letona Paola , Gittelsohn Joel , Ramirez-Zea Manuel , Caballero Benjamin 
Published: June 2021

ObjectiveChronic disease risk factors have increased in children, even in developing countries. Preventive interventions that address modifiable risk factors are needed. Formative research was conducted to assess perceptions about health concerns for children; factors that influence their diet, physical activity and tobacco use; and community resources available for the promotion of healthy lifestyles.MethodsA convenience sample of 6 schools located in 3 low‐income urban communities of Guatemala City was studied. At each school, focus group discussions, semi‐structured interviews, home visits, and direct observations of the surroundings were conducted, with the participation of children (10–12 y old), teachers, parents, school administrators, food vendors and community leaders.ResultsAll groups expressed similar concerns about modifiable risk factors in children, including high violence rates, food advertising, mother's employment, family customs, bullying and negative emotions that seem to increase unhealthy behaviors. Adults were more concerned with tobacco and alcohol use compared to unhealthy diet and physical inactivity. Government programs and religious groups were identified as community resources.ConclusionsThese findings were used to develop the first community‐based intervention for chronic disease prevention in Guatemala.Grant Funding Source : NHLBI ‐ HHSN 268200900028C
A Worksite‐based Weight Loss Intervention for Obesity Prevention
Authors: Salinardi Taylor , Batra Payal , Das Sai Krupa , Robinson Lisa , Lichtenstein Alice H. , Deckersbach Thilo , Roberts Susan 
Published: June 2021

Worksites are increasingly being used as locations for implementing healthy diet and weight loss interventions. Hence, there is an urgent need to identify programs that are both successful and sustainable. We conducted a 6‐month pilot randomized controlled trial in overweight and obese employees at 4 worksites (2 intervention; 2 delayed intervention sites) to examine the effects of a worksite‐based intervention on weight loss and changes in cardiovascular risk factors. The intervention combined recommendations to consume a high fiber, low glycemic load diet with education on nutrition and behavior change. Fasting body weight, cholesterol, glucose, and blood pressure were measured at baseline and 6 months in 118 subjects. Results were analyzed using an ANCOVA model with baseline values as covariates. Participants at the intervention sites (n=82) lost significantly more weight (−8.0±6.7 vs. +0.6±2.8 kg, p<0.0001) and had greater decreases in fasting total cholesterol (−13.2±25.0 vs. −2.4±24.2 mg/dl, p=0.0423), fasting glucose (−6.4±13.2 vs. +5.7±18.0 mg/dl, p=0.0006), systolic blood pressure (−8.6±12.6 vs. +5.5±10.8 mmHg, p<0.0001), and diastolic blood pressure (− 8.2±10.9 vs. −0.5±6.7 mmHg, p=0.0007) as compared to participants at control sites (n=33). This worksite intervention resulted in significant weight loss and improvements in cardiovascular risk factors relative to no intervention.Grant Funding Source: USDA Human Nutrition Research Center
Association between total water intake, micronutrient intakes and serum nutrient profile among U.S. adults
Authors: Yang Meng , Park Sohyun , Chun Ock K. 
Published: June 2021

Given the paucity of investigations on nutrient status by water intake, we examined water intake by sociodemographic factors and its association with dietary and serum micronutrient levels among 3,189 US adults (≥20 y). We used two 24‐h dietary recalls and serum nutrient data from NHANES 2005–2006. The daily mean total water intake was 3.1 L, with 68% adults under Adequate Intake (AI) level. Total water intake was higher in adults aged 31–50 y, non‐Hispanic whites, adults with higher BMI, education and physical activity, those taking supplements, alcohol consumers, and current smokers. In multivariate regression analyses, plain water intake was positively associated with food moisture and negatively with beverage moisture (excluding plain water, P<0.001). Beverage moisture was negatively associated with food moisture (P<0.05). Plain water and food moisture intakes were positively associated with Ca, Fe, Mg, vitamin A, C, E, K, B6, niacin and carotenoids (P<0.05), but beverage moisture was unrelated (Ca, Mg, vitamin B6, niacin, α‐carotene) or negatively (Fe, vitamin A, C, E, K, β‐carotene) associated (P<0.05). Concentrations of serum B12, C, E, and carotenoids increased with plain water and food moisture intake (P<0.05) and decreased (P<0.01) or were unrelated with beverage moisture. Various contributors of total water intake differed in their associations with micronutrient intake in adults.Grant Funding Source : Self‐funded
Racial Differences in Plasma Omega‐3 Long Chain Fatty Acid Levels in a Cohort of African Americans and European Americans with Diabetes and Metabolic Syndrome
Authors: Wilson Bryan Anthony , Sergeant Susan , Ainsworth Hannah , Mathias Rasika , Chilton Floyd H. 
Published: June 2021

BackgroundWe have shown that polymorphisms in the fatty acid desaturase 1 gene (FADS1) are associated with racial differences in omega‐6 long‐chain polyunsaturated fatty acid (LC‐PUFA) metabolism. We thus examined whether racial differences also exist in omega‐3 (ω3) LC‐PUFA metabolism.MethodsWe used GLC to measure levels of the LC‐PUFA precursor α‐linolenic acid (18:3, ALA) and the major ω3 LC‐PUFAs eicosapentanoic (22:5, EPA), docosapentaenoic (24:5, DPA) and docosahexanoic (24:6, DHA) acids in fasting plasma from 63 African Americans (AfAm) and 166 European Americans (EAm) with diabetes or metabolic syndrome.ResultsCompared to EAm, AfAm had significantly lower ALA (2.0 ± 1.2 vs 3.1 ± 2.1, p<0.001) and DPA (1.7 ± 0.5 vs 2.0 ± 0.8, p=0.006) levels, whereas DHA levels were significantly higher (6.8 ± 2.6 vs 5.6 ± 2.2, p<0.001). EPA levels were no different. Compared to EAm, fatty acid product:precursor ratios were significantly higher in AfAm for DHA:ALA, 3.8 ± 1.6 vs 2.1 ± 0.9, p<0.001; EPA:ALA, 1.2 ± 0.9 vs 0.8 ± 0.6, p<0.001, and DHA:DPA, 4.1 ± 1.4 vs 3.0 ± 1.0, P<0.001.ConclusionsAs product:precursor ratios of circulating ω3 PUFAs provide a surrogate measure of substrate flux through the LC‐PUFA synthesis pathway, these data suggest that AfAm display enhanced conversion of ω3 precursors to LC‐PUFA, which may be due to genetically‐determined increased activity of the FADS1 desaturase and elongase genes.Grant Funding Source : NIH Grants: 5P50AT002782‐07, 3P50AT002782‐07S1
Application of collagen coated silicone scaffolds for the three‐dimensional cell culture of primary rat hepatocytes
Authors: Stock Peggy , Winkelmann Claudia , Thonig Antje , Böttcher Gunther , Wenske Günther , Christ Bruno 
Published: June 2021

Primary hepatocytes present an appropriate validation system for toxicological studies of novel agents in pharmaceutical‐ and cosmetics industries. Until today, three dimensional culture systems maintaining the functionality of hepatocytes are missing.The aim was to analyse the applicability of 3D collagen‐coated silicone scaffolds versus 2D culture for culture of rat hepatocytes.Primary rat hepatocytes were cultivated for 72h on multilayer lattice structures (A=23.7cm2) and compared with 2D culture on conventional dishes (A=8.9cm2). Cell counts, the growth pattern on silicone and the urea production rate were determined.Based on identical initial cell counts the growth rate was about 42%±5% higher in 3D culture as compared to 2D. Under serum‐free conditions cells attached to the scaffold, formed clusters and organ‐like structures. The 3D culture on the silicone scaffold displayed no significant cytotoxicity after 72h: the percentages of dead cells were 7%±3% vs 9%±3%. The urea production rate [μg/105 cells] was significantly higher in the 3D vs 2D: 24h 9.1±2.7 vs 4.7±0.2; 48h 5.7±1.5 vs 3.7±0.05 72h 3.5±0.5 vs 2.1±0.1.The results show the appropriateness of silicone scaffolds for the 3D culture of primary rat hepatocytes. Thus, the collagen‐coated silicone scaffolds represent an important tool for the development of 3D hepatocyte cultures sustaining the physiological functions.