bluuebunny/crossref_metadata_2025_split huggingface dataset:
TISSUE‐SPECIFIC GENETIC TARGETING OF INOS REVEALS AN UNEXPECTED ROLE OF ADIPOCYTE INOS IN THE DEVELOPMENT OF INSULIN RESISTANCE, DYSLIPIDEMIA AND ALTERED ENERGY METABOLISM IN DIET‐INDUCED OBESE MICE
Authors: Vilela Vanessa Rodrigues , Lachance Gabriel , Nachbar Renato Tadeu , Centano‐Baez Carolina , Bellmann Kerstin , Marette André 
Published: June 2021

Nitric oxide (NO) is synthesized from L‐arginine by NO synthase (NOS) enzymes. The expression of the inducible member of the NOS family, iNOS, is markedly enhanced in adipose, skeletal muscle and liver tissues in response to bacterial endotoxins (LPS), inflammatory cytokines, and diet‐induced obesity. We have previously showed that mice lacking iNOS are protected from insulin resistance induced by high‐fat feeding; acute exposure to LPS or lipid infusion, providing genetic evidence that iNOS is a key inflammatory mediator in these settings. It is believed that in immune cells within adipose tissue of obese animals mainly contribute to iNOS expression and the immunometabolic perturbances of obesity. To clarify the specific role of iNOS induction in adipocytes, muscle and liver in the development of insulin resistance and altered energy metabolism of obese animals, mice containing flox sites flanking Exon 2 of nos2 were created. Myocyte‐specific (MuKO), hepatocyte‐specific (HeKO) and adipocyte‐specific (AdKO) iNOS knockout mice were generated on a C57BL/6J background by crossing mice homozygous for floxed iNOS (nos2f/f) with Ckmm‐cre, Alb‐Cre and Adipoq‐Cre, respectively. KO mice and their respective wild‐type controls were fed regular chow or a high‐fat/high sucrose (HFHS) diet for 8 weeks and then extensively phenotyped for metabolic outcomes. We found that AdKO mice were partially protected from HFHS‐diet insulin resistance as compared to WT littermates on the same diet, and that this beneficial effect was associated with increased energy expenditure as measured by indirect calorimetry. These effects were observed despite no differences in body weight gain and adiposity. Adipocyte‐specific iNOS KO was also associated with a reduction in circulating triglyceride levels upon HFHS feeding. However, disrupting iNOS selectively in skeletal muscle and liver did not improve metabolic phenotypes after 2 months of HFHS feeding. Our results reveal an unexpected role of iNOS specifically expressed in adipocytes in the development of systemic insulin resistance, dyslipidemia and altered energy metabolism in diet‐induced obesity, suggesting an important role of adipocyte NO release in the metabolic complications of obesity. The role of muscle and liver iNOS appears limited after 2 months of HFHS diet but studies are underway to document their potential impact after longer‐term feeding experiments.Support or Funding InformationCanadian Institutes of Health ResearchThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
IDH2 Deficiency Aggravates Fructose‐Induced NAFLD by Activating Inflammatory Signaling in Female Mice
Authors: Beane Kaleigh E. , Montalbano Allison M. , Pan Jeong Hoon , Kong Byungwhi C. , Kim Jae Kyeom 
Published: June 2021

Fructose is a strong risk factor of non‐alcoholic fatty liver disease (NAFLD), resulting from disruption of redox systems by excessive reactive oxygen species production in the liver cells. Importantly, recent epidemiological studies indicated that women are more prone to develop metabolic syndrome in response to fructose‐sweetened beverages. Here, we examined whether disruption of redox system exacerbates fructose‐induced NAFLD conditions in female mice. The redox system was disrupted by blocking NADPH supply through mitochondrial NADP+‐dependent isocitrate dehydrogenase knock‐out (IDH2 KO) in C57BL/6 female mice. After, wild type (WT) and IDH2 KO mice were treated with either water or 34% fructose water over six weeks. NAFLD phenotypes and key proteins and mRNAs involved in inflammatory pathway (e.g., NF‐κB p65 and IL‐1β) were assessed. As results, hepatic lipid accumulation was significantly increased in IDH2 KO mice fed fructose compared to its WT counterpart. Neutrophil infiltration was observed only in IDH2 KO mice fed fructose. Further, phosphorylation of NF‐κB p65 and expression of IL‐1β was remarkably upregulated in IDH2 KO mice fed fructose, and expression of IκBα was decreased by fructose treatment in both WT and IDH2 KO groups. For the first time, we report that IDH2 KO significantly aggravates fructose‐induced NAFLD phenotypes (fatty liver and neutrophil infiltration) and related inflammatory responses (i.e., NF‐κB p65 pathway). Collectively, this study provides evidence that IDH2 deficiency may have implications on fructose‐induced NAFLD through suppression of fatty acid β‐oxidation and/or activation of the NF‐κB pathway. Given our significant phenotypes in response to fructose intervention, the present study will provide a good justification for further characterization thus warrants additional investigations to clarify mechanistic roles of mice IDH2 in metabolic diseases.Support or Funding InformationThis work was supported by the University of Arkansas, VPRED Start‐up fund (KJK, and PJH). Support has been provided in part by the Arkansas Biosciences Institute, a partnership of scientists from Arkansas Children's Hospital, Arkansas State University, the University of Arkansas‐Division of Agriculture, the University of Arkansas, Fayetteville, and the University of Arkansas for Medical Sciences. The Arkansas Biosciences Institute is the major research component of the Arkansas Tobacco Settlement Proceeds Act of 2000 (JKK, JHP, KEB, and BCK).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Enhancement of biological activity through conversion of rutin to quercetin using acid treatment
Authors: Yang Jinwoo , Lee Junsoo 
Published: June 2021

Flavonoids attract much attention due to their various physiological properties and these compounds naturally exist as their glycoside forms. Rutin, one of the most abundant flavonoids in nature, is composed of the aglycone quercetin and the disaccharide rutinose. Although, there is a structural similarity in rutin and quercetin, there are some obvious differences in physical, chemical, and biological characters. It is reported that quercetin has a higher biological activity than other glycosidic quercetin derivatives. Thus, de‐glycosylation of rutin would be an important process for enhanced biological activities. Therefore, in this study, to convert rutin to quercetin, the effects of acid concentrations and solvents were investigated and biological activities were evaluated. As a results, when 80 % ethanol was used, the hydrolysis of rutin was more rapid than water as solvent for reaction. Hydrolysis of rutin was also accelerated as the acid concentration increased from 0.1 to 1.0 M of HCl. Anti‐oxidant, anti‐inflammatory, and anti‐adipogenic activities were increased with the increased conversion rate of rutin to quercetin. These results suggest that the acid treatment can be used as a process to improve the physiological activity of glycoside flavonoids.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Enhanced Mitochondrial DNA Repair Confers Protection Against Obesity and Metabolic Syndrome by Altering White Adipose Tissue Energetics
Authors: Komakula Sai Santosh Babu , Tumova Jana , Ye Hong , Vartanian Vladimir , Lloyd R Stephen , Akal Tasleen , Sampath Harini 
Published: June 2021

Oxidative DNA damage is characterized by oxidative modifications of nuclear and mitochondrial DNA. Unrepaired DNA lesions can cause mutations. Mitochondrial DNA is more prone to oxidative damage when compared to nuclear DNA. 8‐oxo‐Guanine (8‐oxoG) is the most abundant oxidative DNA lesion, which is primarily repaired by the base excision repair (BER) pathway. BER is initiated by DNA glycosyslases such as 8‐oxo‐Guanine DNA glycosylase (OGG1) that recognizes and cleaves 8‐oxoG from nuclear and mitochondrial DNA. Previously, we reported that mice lacking OGG1 both in the nucleus and mitochondria are more prone to obesity and metabolic dysfunction compared to wild type controls. However, the contribution of mitochondrial vs. nuclear OGG1 to this metabolic phenotype have not been reported. We report here that transgenic mice over expressing human OGG1 only in the mitochondria (Ogg1Tg mice) are protected from high fat diet induced obesity, insulin resistance, fatty liver, and other features of metabolic syndrome, relative to diet‐matched wild type counterparts. The observed phenotype is a consequence of altered energy metabolism in white adipose tissue. Our results indicate that white adipose tissue of Ogg1Tg mice have increased respiration due to mitochondrial uncoupling and increased expression of Pgc‐1α, Sirtuin‐1, and uncoupling protein‐3. Plasma adiponectin levels are also elevated in Ogg1Tg mice. Electron microscopy results indicate that, Ogg1Tg mice on high fat diet have elongated and more electron dense mitochondria. These results confirm a novel and critical role for the mitochondrial DNA repair and structure on whole body energy homeostasis. These findings also indicate an important role for white adipose tissue mitochondrial metabolism on whole body energy balance.Support or Funding InformationThe Sampath lab is supported by the NJ Institute for Food Nutrition and Health, NIH grant R00DK100640 (Sampath PI) and a Euro Bio4Med grant (Sampath Co‐PI)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Fibroblast Growth Factor 21 Promotes Glucose Uptake in Adult Skeletal Muscle Fibers from Mice
Authors: Rosales‐Soto Giovanni , Díaz‐Vegas Alexis , Llanos Paola , Jaimovich Enrique , Contreras‐Ferrat Ariel 
Published: June 2021

IntroductionFibroblast growth factor 21 (FGF21) is a pleiotropic peptide hormone that has effects in several organs including skeletal muscle, liver and adipose tissue. FGF21 improves the glucose tolerance test in obese‐insulin resistance mice in vivo and increases the glucose uptake in both primary myotubes and C2C12 myoblasts in vitro. However, the effect of FGF21 on glucose uptake and the cellular mechanism involved in this process in adult skeletal muscle fibers is poorly understood. The aim of this study is to assess the effect of FGF21 on GLUT4‐mediated glucose uptake in isolated skeletal muscle fibers.Material and MethodsMale mice were used at 6–8 weeks of age. The effect of FGF21 on GLUT4‐mediated glucose uptake was evaluated in single living fibers from flexor digitorum brevis muscle. To determine the glucose uptake, we used 2‐[N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)amino]‐2‐deoxy‐D‐glucose (2‐NBDG) (300 μM) a phosphorylable, non‐metabolizable fluorescent glucose analog that has been used to monitor glucose uptake in single living cells.ResultsFGF21 induces a dose‐response effect, increasing the glucose uptake in isolated muscle fibers. This effect is prevented by the use of either Cytochalasin B (5 μM) or Indinavir (100 μM), both antagonists of GLUT4 activity. The use of PI3K inhibitors such as Wortmannin (100 nM) and LY294002 (50 μM) prevents the FGF21‐dependent glucose uptake. Furthermore, FGF21 does not promote Akt phosphorylation in isolated FDB fibers. In fibers electroporated with the construct encoding GLUT4myc‐eGFP chimera and stimulated with FGF21 (100 ng/mL) for 20 min, a strong sarcolemmal GLUT4 presence was detected.ConclusionsThese results suggest that FGF21 promotes GLUT4‐dependent glucose uptake by a mechanism independent of the serine/threonine kinase Akt phosphorylation. This mechanism could be an important therapeutic target to treatment of insulin resistance and type 2 diabetes.Support or Funding InformationFinanced by FONDECYT 11130267 (AC‐F), 1151293 (EJ) & 11150243 (PL).CONICYT‐PFCHA/Doctorado Nacional/2017‐21171449This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Serum Leptin is associated with Fasting Plasma Glucose and Serum Insulin Levels independent of BMI in Haitian Americans with Type 2 Diabetes
Authors: Antwi Janet , Proulx William , Sullivan Stacey , Lavin Rebecca , Bellavia Maria 
Published: June 2021

ObjectiveLeptin is an adipose tissue derived peptide considered both structurally and functionally as a pro‐inflammatory adipocytokine. Leptin has been associated with metabolic risks and type 2 diabetes (T2D). Haitian Americans are an understudied ethnic Blacks at risk for T2D. We aimed to measure serum leptin levels in Haitian Americans with and without T2D and to examine the relationship of serum leptin with metabolic risk factors of T2D.MethodsCross‐sectional analysis in 213 Haitian Americans, 100 with T2D and 113 without T2D. Fasting plasma glucose levels (FPG) were measured by hexokinase enzymatic methods (Laboratory Corporation of America, FL, USA). Fasting serum insulin levels were determined with enzyme‐linked immunosorbent assay (ELISA) using commercially available kits (Millipore, St Charles, MS, USA). Serum leptin levels was analyzed by ELISA (R&D Systems, Minneapolis, MN, USA).ResultsSerum log leptin levels were significantly higher in both females with and without T2D compared to males with and without T2D (P<0.001). Females with T2D had higher body mass index (BMI, obese) compared to males with T2D (P=0.016), while higher BMI in females without T2D (overweight) had a trend towards significance compared to males without T2D (P=0.099). Multiple linear regression demonstrated that in subjects with T2D, serum log leptin levels were significantly associated with FPG (B=‐0.004, P=0.012) and fasting serum insulin levels (B=−0.058, P=0.026) after adjustment for age, gender, BMI, total energy intake, physical activity and smoking status. The association was not statically significant in subjects without T2D after controlling for the same covariates. Serum log leptin levels were significantly associated with BMI in both subjects with (B=0.095, P=0.020) and without T2D (B=0.080, P=0.001).ConclusionThere is a significant association between FPG and fasting serum insulin levels in Haitian Americans with T2D, independent of adiposity, demographic and behavioral factors. This may suggest that serum leptin level is an important factor of metabolic risks of T2D irrespective of obesity levels. Thus, leptin levels may be used to identify diabetes‐metabolic risk in Haitian Americans.Support or Funding InformationThis research was funded by a NIH/NIDDK grant.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Convenient and Sensitive Assay for the Screening of Lysosomal Storage Disorders
Authors: Stokes Erin 
Published: June 2021

Lysosomal storage diseases such as Fabry disease comprise a rare set of disorders that may be undiagnosed until adult life when therapies, including enzyme replacement, substrate depletion, and molecular chaperones, are less effective. Routine clinical diagnoses and laboratory tests by direct enzyme assay are available only at selected specialized major research centers and are not generally available due to the requirements for dedicated and expensive reagents, equipment, and personnel. We report here the development of a convenient, sensitive and rapid continuous enzyme assay for routine screening and diagnosis that can be carried out using microtiter plate assays that is also suitable for automated multiplex, high‐throughput, and robotic analyses. The incidence of individual lysosomal storage diseases is low, but considered together these disorders comprise significant morbidity and mortality with a cumulative incidence of about 1:5,000, and newborn screening studies suggest that it could be significantly higher. Early diagnosis and treatment of Fabry disease and 24 other lysosomal storage disorders is expected to result a significant reduction in morbidity and mortality with concomitant reduction in medical support and expenses.Support or Funding InformationNIH SBIR Grants and Royalty Income From PatentsThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The lipid A 1‐phosphatase, LpxE, play multiple roles in bacteria envelope biogenesis
Authors: An Jinsu , Zhao Jinshi , Hwang Dohyeon , Gillespie Robert A. , Yang Eun Gyeong , Zhou Pei , Chung Hak Suk 
Published: June 2021

Gram‐negative bacteria cell envelope is multilayered structure that consist of lipopolysaccharide at outer leaflet of the outer‐membrane, peptidoglycan at periplasmic space and glycerophospholipids which is the major component of inner‐membrane and the inner leaflet of the outer‐membrane. Distinct lipid phosphatases are thought to be involved in cell envelope biogenesis by dephosphorylating precursors such as lipid A, undecaprenyl pyrophosphate (C55‐PP) and phosphatidylglycerol phosphate (PGP). Lipid A 1‐phosphatase (LpxE) is a member of the lipid phosphatase/phosphotransferase (LPT) family, which is responsible for bacterial virulence, cationic antibiotic resistance and modulation of the host innate immune system. We report the identification of lipid phosphatase, named as LpxEAA in Aquifex aeolicus (A.aeolicus) VF5, capable of dephosphorylating all of above lipid precursors. Additionally, we show that the LpxE from the human pathogens Francisella (LpxEFN) and Helicobacter (LpxEHP) are not only able to dephosphorylating lipid A but also C55‐PP and/or PGP, respectively. This multi‐functionalities of LpxE suggests that it could participate in a wide range of bacterial envelope biogenesis, beyond the well‐established lipid A 1‐phosphatase activity. Based on our research, we hypothesized that pathogens which have LpxE could survive against various environmental changes by regulating the overall bacterial envelope biogenesis through LpxE activity.Support or Funding InformationThis work was supported by National Institutes of Health (NIH) grants (GM051796 to C.R.H.R and P.Z. and AI055588 to P.Z.) and Kist intramural grants (2E27391 to H.S.C and 2E27470 to S.H.K), We thank Dr. Ziqiang Guan for assisting mass spectrometry analysis.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Probing the Role of Peptidoglycan Metabolism in Helicobacter pylori's Helical Shape
Authors: Taylor Jennifer A. , Bratton Benjamin P. , DeMeester Kristen E. , Liang Hai , Jacobs Holly M. , Kuru Erkin , Brun Yves V. , VanNieuwenhze Michael S. , Vollmer Waldemar , Shaevitz Joshua W. , Grimes Catherine L. , Salama Nina R. 
Published: June 2021

Helical cell shape is important for Helicobacter pylori's ability to colonize the human stomach. Cell shape in this Gram‐negative pathogen is determined by the cell wall, which is composed of peptidoglycan (PG), a polymer of disaccharides with an attached pentapeptide stem that can join glycan strands by crosslinking with an adjacent peptide stem. Maintaining helical shape requires the activity of two endopeptidases, two carboxypeptidases, and several non‐enzymatic proteins. This suggests that structural modification of the PG is essential for shape maintenance, but it is unclear whether structural modification alone is sufficient or if modifications act in concert with PG synthesis and/or turnover. The most widely‐adopted metabolic probe for labeling new PG synthesis is either a small fluorophore or clickable alkyne conjugated to D‐alanine, which is present in the two terminal positions in the PG peptide stem. However, this probe appears to be mainly incorporated through transpeptidation reactions, which do occur at new PG synthesis sites, but may also occur during synthesis‐independent modification of the cell wall. We generated a strain of H. pylori that expresses Pseudomonas putida N‐acetylmuramic acid (MurNAc ) recycling enzymes AmgK and MurU and is capable of incorporating the newly‐developed MurNAc‐alkyne probe into the cell wall. We are employing quantitative analysis of 3D structured illumination microscopy (SIM) images to define the different regions of the helical cell using Gaussian curvature and to measure whether D‐alanine‐alkyne and MurNAc‐alkyne are preferentially enriched at positive or negative curvature (major or minor helical axis of a helical cell, respectively). Preliminary results indicate that the two probes show different curvature enrichment and suggest that crosslinking activity occurs independently of new PG synthesis and/or crosslinking rates during synthesis differ at different parts of the cell. These results suggest a role for spatial regulation of both structural variation and new PG synthesis in maintaining H. pylori's helical cell shape. Furthermore, these results demonstrate the value of employing both metabolic probes to investigate cell growth and shape maintenance.Support or Funding InformationThis material is based upon work supported by the National Institutes of Health R01 AI094839 and U01 CA221230, the National Science Foundation Graduate Research Fellowship under Grant No. DGE‐0718124 and DGE‐1256082, and the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Development and Characterization of Antibodies to Site‐specific O‐GlcNAc modified Histones for Epigenetic Research
Authors: Orlando Ron , Popov Marla , Gutierrez‐Sanchez Gerardo 
Published: June 2021

O‐glycosylation of nuclear and cytoplasmic proteins by a single β‐N‐acetyl‐D‐glucosamine moiety (O‐GlcNAc) is a common post‐translational modification that is highly dynamic and fluctuates in response to cellular stimuli. This type of glycosylation has been found on approximately a thousand human proteins to date and is thought to be nearly as widespread and abundant as protein phosphorylation. Many of the first proteins identified carrying this modification were transcription factors, and it became apparent in the last several years that O‐GlcNAc plays a significant role in chromatin remodeling and gene expression.Given the complexity of the histone code, site‐specific antibodies are needed to begin to elucidate the hierarchy of modifications as well as the biological significance of single and multiple post‐translational modifications of the histones. We have developed and approach to provide high‐affinity site‐specific O‐GlcNAc antibodies that appear to overcome issues related to small carbohydrates being poor antigens and the O‐GlcNAc modified epitopes being self‐antigens. These site‐specific antibodies require a more elaborate characterization scheme than other antibodies as they need to demonstrate both a preference for the O‐GlcNAcylated species over the native peptide sequence and a specificity to the amino acid sequence. We use a multistep evaluation process to characterize our antibodies. 1) ELISA assay, to determine the preference of the antibody to the O‐GlcNAcylated peptide over the unmodified form; 2) Cross‐reactivity of the antibody to other peptide sequences modified with O‐GlcNAc; 3) Immunoprecipitation increasing wash stringencies and 4) Evaluation of the site‐specific O‐GlcNAc histone antibodies for their potential as ChIP‐Seq reagents. Using this process, we have authenticated our site‐specific O‐GlcNAc antibodies and have demonstrated that they possess the preference and specificity needed for epigenetic research.Support or Funding InformationResearch reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Numbers 1R43GM110887‐01 and R44GM110887‐02.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.