bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flame Retardant, Hexabromocyclododecane, Alters Secretion of Interleukin 6 from Human Immune Cells
Authors: Shelby Elizabeth M. , Falconer April , Whalen Margaret M 
Published: June 2021

Hexabromocyclododecane (HBCD) is a brominated flame retardant compound. It is used in polystyrene insulation, accumulates in living organisms and is highly toxic to aquatic organisms. Interleukin 6 (IL‐6) is a pro‐inflammatory protein that is produced by T lymphocytes and monocytes (as well as other cells). It regulates cell growth, tissue repair, and immune functions. Previous studies have shown that HBCD alters the secretion of cytokines IL‐1β, TNFα, and INFγ from human immune cells. Due to the important role IL‐6 plays in immune responsiveness, it is important to understand whether exposures to HBCD are able to disrupt its secretion. HBCD is found in human blood and previous studies have shown that it inhibits the ability of human NK lymphocytes to destroy tumor cells. This study examines whether HBCD affects the secretion of IL‐6 from monocyte‐depleted (MD) human peripheral blood mononuclear cells (PBMCs). IL‐6 secretion was measured by enzyme linked immunosorbent assay (ELISA). Results indicate that exposures of MD‐PBMCs to different concentrations of HBCD (ranging from 5–0.05 μM) for 24 h increase secretion of IL‐6 from these immune cells. Thus, exposure to HBCD may potentially disrupt the immune regulation mediated by IL‐6.Support or Funding InformationSupported by NIH grant 2 T34GM007663.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Aging‐induced Mitochondrial Damage: The Role of Endoplasmic Reticulum Stress
Authors: Chen Qun , Thompson Jeremy , Hu Ying , Lesnefsky Edward J. 
Published: June 2021

RationaleMitochondrial (MITO) dysfunction occurs with age in the heart and decreases the tolerance of the aged heart to superimposed cardiac stress. It is unclear how aging leads to MITO dysfunction. The endoplasmic reticulum (ER) is closely connected to MITO via shared membrane domains that mediate ER‐MITO cross‐talk including calcium loading. Induction of ER stress leads to MITO dysfunction in adult hearts. ER stress is increased with aging in the heart.ObjectiveTo study the contribution of ER stress to MITO dysfunction during the progression of cardiac aging.MethodsSubsarcolemmal MITO (SSM) and interfibrillar MITO (IFM) were isolated from 3, 12, 18, and 24 Mon. male C57BL/6 mouse hearts (NIA Colony, Charles River). Oxidative phosphorylation (OXPHOS, nAO/min/mg protein) was measured in isolated MITO. Calcium Retention Capacity (nmol calcium/mg protein) was used to reflect the sensitivity to calcium‐induced mitochondria permeability transition pore opening (MPTP). The contents of CHOP (transcription factor C/EBP homologous protein) and cleaved ATF6 (50 kDa) were used as markers of ER stress.ResultsER stress increased during aging as shown by greater CHOP and cleaved ATF6 contents at 18 Mon. (Figure) whereas OXPHOS remained unchanged (Table). OXPHOS with complex I (glutamate+malate) and complex IV (TMPD+ascorbate) substrates was decreased at 24 Mon. in IFM. OXPHOS in SSM remained unaltered by age (data not shown). Susceptibility to (MPTP) opening was increased at 24 Mon. in IFM.ConclusionAging leads to increased ER stress that occurs before the onset of MITO dysfunction. ER‐IFM crosstalk, likely involving altered Ca+2 dynamics as indicated by increased MPTP susceptibility, is a potential new mechanism of age‐induced MITO defects in the heart. Age‐induced defects in IFM, in turn, exacerbate cardiac injury in response to superimposed cardiac disease, including ischemia‐reperfusion.Support or Funding InformationThis work was supported by the Office of Research and Development, Medical Research Service Merit Review Award (2IO1BX001355‐01A2) and Department of Veterans Affairs (EJL); National Institutes of Health NIH R21AG054975‐01 (QC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Metformin Has Direct Protective Effect on Human Cardiac Mitochondria
Authors: Emelyanova Larisa , Rudic Theodore , Ross Gracious R. , Rizvi Farhan , Kress David C. , Jahangir Arshad 
Published: June 2021

ObjectiveMetformin (Metf), an oral antihyperglycemic agent, is widely used to treat type 2 diabetes mellitus. The primary action of the drug is to lower hepatic glucose synthesis and enhance peripheral glucose uptake via activation of the insulin receptor. It also exerts a cardioprotective effect independent of its glucose lowering action; however, mechanisms underlying cardioprotection in the human heart remain poorly defined. We hypothesize that the cardioprotective effect of Metf is associated with mild inhibition of mitochondrial oxidative phosphorylation (OXPHOS) and reduction of oxidative stress that protect mitochondria against permeability transition pore (PTP) opening.MethodsLeft atrial appendage tissue was collected from middle‐aged and elderly patients (n=21) undergoing open‐heart surgery. Mitochondria were isolated from fresh tissue using differential centrifugation and exposed to different concentrations of Metf (0–10 mM). The functional activity of mitochondrial OXPHOS complexes (CI‐V) was measured spectrophotometrically using specific OXPHOS inhibitors, electron donors, and acceptors. Superoxide production was measured by monitoring changes in fluorescence intensity of dihydroethidium (DHE) in the absence and presence of antimycin A (AA, 5 μM). The sensitivity of mitochondria toward PTP opening was assessed by exposing isolated mitochondria to 10 μM of Ca2+ pulses and monitoring abrupt mitochondrial Ca2+ release (Fluo‐5N fluorescence) and swelling of the matrix (decrease in absorbance). The study was approved by the Aurora Institutional Review Board and adhered to the Health Insurance Portability and Accountability Act and Aurora Health Care patient privacy and security guidelines. The study followed the principles of the Declaration of Helsinki.ResultsMetf had a dose‐dependent mild inhibitory effect on the activity of CI, CIV, and CV without affecting CII and CIII (Figure A). This was associated with reduction of superoxide production before and after exposure of the mitochondria to AA (Figure B). Metf in a dose‐dependent manner also attenuated Ca2+‐induced mPTP opening (Figure C) with delayed swelling of mitochondrial matrix (Figure D).ConclusionMetf improves cardioprotection by increasing tolerance to stress‐induced PTP opening due to its mild inhibitory effect on the OXPHOS and reduction of superoxide production. This can be a beneficial alternative to patients with impaired endogenous cardioprotective responses.Support or Funding InformationN 570‐3657, Cardiac Research Award, Aurora Health CareThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Understanding the Role of Polar Residues on the c‐Ring of E. coli F1Fo ATP Synthase
Authors: Founds Michael , Shrestha Rashmi , Steed Ryan 
Published: June 2021

F1Fo ATP synthases catalyze the synthesis of adenosine triphosphate (ATP), the universal biological energy carrier, and are thus integral to life. The membrane‐embedded Fo sector utilizes the proton electrochemical gradient to generate rotation in the rotor subunits, which drives ATP synthesis in the F1 sector. In addition to ATP synthesis, F1Fo can also hydrolyze ATP to pump protons to create an electrochemical gradient. Recent structural models of ATP synthase from cryo‐electron microscopy have revealed the architecture of the rotor‐stator interface; however, the intricacies of the rotation mechanism are not fully understood. Previous research has identified specific residues of the c subunit of E. coli F1Fo, including Arg50 and Thr51 on the cytoplasmic end of transmembrane helix 2, that may be necessary for the H+ translocation mechanism. Mutation of Arg50 or Thr51 to Cys abolished ATP‐driven H+ pumping and blocked H+‐permeability. Interestingly, these mutants were able to grow in succinate minimal medium, suggesting that ATP synthesis activity was unaffected. Arg50 is part of a proposed charge interaction between subunits a and c, and the polar Thr51 may also participate in this interaction. Therefore, we studied the importance of positive charge and polarity at positions 50 and 51 using chemical and genetic modifications. Chemically appending positive charge onto Cys50 with methanethiosulfonate did not restore ATP‐driven H+ pumping activity. However, mutation of Arg50 to Lys or His supported activity. Mutation of Thr51 to Ser or Asp also supported H+ pumping activity. These studies provide insight into the role of polar residues on the surface of the c‐ring and their contribution to the H+‐driven rotational mechanism of F1Fo ATP synthase.Support or Funding InformationSupported by the North Carolina GlaxoSmithKline Foundation and the University of North Carolina Asheville Undergraduate Research ProgramThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Loss of Carnitine Palmitoyltransferase‐2 in skeletal muscle results in muscle remodeling and tissue‐specific sensitivity to insulin
Authors: Pereyra Andrea S , Ellis Jessica 
Published: June 2021

Dysregulated mitochondrial fatty acid oxidation in skeletal muscle occurs with overfeeding and obesity and is implicated in the development of insulin resistance. To assess the effects of eliminating mitochondrial long‐chain fatty acid oxidation on insulin sensitivity we generated mice with a muscle‐specific deficiency in Carnitine Palmitoyltransferase‐2 (Cpt2Sk−/− mice), an irreplaceable enzyme required for mitochondrial oxidation of long‐chain fatty acids.Cpt2 Sk−/− mice have lower basal glycaemia, hypo‐phosphorylation of Akt in liver and white adipose tissue with preserved Akt‐phosphorylation in muscle, and moderately increased sensitivity to glucose and insulin tolerance tests. Acute insulin stimulation increased Akt phosphorylation to similar levels in control and Cpt2 Sk−/− liver, adipose, and muscle. Thus, the induction in Akt phosphorylation from no‐insulin to insulin‐stimulated is heightened in Cpt2 Sk−/− liver and white adipose, but not in muscle.Cpt2 Sk−/− muscles are free of oxidative stress and do not accumulate lipotoxic ceramides or triacylglycerol. However, Cpt2 Sk−/− muscles, compared to controls, accumulate up to 500‐fold more long‐chain acylcarnitines. Also, Cpt2 Sk−/− muscles undergo remodeling by increasing mitochondria, fiber‐type switching, and alteration in myocyte nuclei size, number, and distribution. Taken together these data suggest that loss of muscle Cpt2 causes adaptive muscle remodeling and improves insulin sensitivity of liver and adipose, but not muscle.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of programming on the hepatic epigenome by maternal low‐fat diet persist in adult offspring fed an obesogenic diet
Authors: Moody Laura , Shao Justin , Xu Guanying Bianca , Chen Hong , Pan Yuan‐Xiang 
Published: June 2021

Obesity and metabolic disease present a risk to long‐term health outcomes. Epigenetic marks such as DNA methylation are established during early life and have effects on later life through developmental programming. In the present study, we examined whether maternal diet alters DNA methylation and whether such modifications persist after an obesogenic postnatal dietary challenge. During gestation and lactation, male Sprague Dawley rats were exposed to either a high‐fat diet (HF; n = 10) or low‐fat diet (LF; n = 10). After weaning, all animals were fed the HF diet until postnatal week 12. There were no differences observed in food intake or body weight between the two groups of offspring animals. Hepatic DNA methylation was quantified using both Methylated DNA Immunoprecipitation sequencing (MeDIP‐seq) and Methylation‐sensitive Restriction Enzyme sequencing (MRE‐seq). Overall, 1,419 differentially methylated regions (DMRs) were identified. DMRs tended to be located in CpG shores, as opposed to CpG islands, and were enriched for genes involved in metabolism and cancer. Gene expression was measured for 31 candidate genes in these pathways. Among these, Map3k5 and Igf1r were confirmed to be differentially expressed. When the functional relevance of intergenic DMRs was quantified using chromatin contact data, we discovered that conserved DMRs were topologically associated with metabolism genes, which was associated with differential expression of Adh5, Enox1, and Pik3c3. Overall, although maternal dietary fat was unable to reverse offspring weight gain in response to postnatal obesogenic diet, early life diet did program the hepatic methylome. Epigenetic alterations on the hepatic methylome occur primarily in metabolic and cancer pathways and are associated with altered gene expression. Physiological consequences of these epigenetic marks will require future investigations for a better understanding of epigenomic programming.Support or Funding InformationThis project was supported by UIUC Research Board grant #12192, the USDA Cooperative State Research, Education and Extension Service, Hatch project numbers # ILLU‐698‐923 and ILLU‐698‐369, ILLU‐698‐391, and the Data Purchase Program from the University of Illinois Library.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Silk Peptide from Bombyx mori Promotes Browning and Inhibits Fat Accumulation in Subcutaneous White Adipocytes
Authors: Lee Kippeum , Seo Young‐Jin , Chei Sungwoo , Song Ji‐Hyeon , Jin Heegu , Oh Jae‐Hoon , Oh Hyun‐Ji , Lee Boo‐Yong 
Published: June 2021

Obesity is characterized as an excessive accumulation of fat in subcutaneous tissues. It is very influential for various diseases including cardiovascular disorders, type 2 diabetes. Adipose tissue is consisted of two types of cell, which are WATs and BATs. WAT principally stores lipid in the form of TGs, thereby acting as a repository of surplus energy in the body. On the other hands, BAT utilizes stored lipid for nonshivering thermogenesis, involving β‐oxidation and uncoupling of oxidative phosphorylation in mitochondria.Silk peptide and extracts of silkworm have diverse pharmacological activities, inducing hyperglycemia, hyperlipidemia, and anti‐oxidant effect. As well as, silk peptide decreases lipid metabolism and body fat accumulation. However adipose browning mechanism as an one of anti‐obesity effect has not been elucidated.In this research, silk peptides increases UCP1 expression and mitochondrial biogenesis in subcutaneous white adipose cells isolated from ICR mice. As well as, silk peptides induces BAT‐like differentiation of adipocytes and thermogenic activation, a process that also involves the upregulation of FAO. In conclusion, we suggest that silk peptides‐induced UCP1 activation in adipocytes have prospective therapeutic value for obesity suppression and associated metabolic disease.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Protective Role of Lycium Barbarum Polysaccharides and C‐Phycocyanin against Ethanol‐Induced Gastric Ulcer
Authors: Lian Yu Zhi , Ni Po‐Yuan , Chao Jane C‐J 
Published: June 2021

Gastric ulcer is a major complication of gastrointestinal disease. This study investigated the gastroprotective effect of Lycium barbarum polysaccharids (LBPs) and C‐phycoyanin (C‐PC) on ethanol‐induced gastric ulcer in rats. Male Sprague‐Dawley rats were divided into 5 groups: normal, ulcer, ulcer treated with 100 mg/kg BW LBPs, ulcer treated with 50 mg/kg BW C‐PC, and ulcer treated with a mixture of 50 mg/kg BW LBPs and 25 mg/kg BW C‐PC. The treatments were given daily by gavage from week 1 to 5, and gastric ulcer was induced by 50% ethanol via gavage every other day from week 2 to 5. Ulcer area, serum hydroxyproline ‐ a potential biomarker for gastric ulcer, serum lipid peroxide ‐ malondialdehyde (MDA), gastric inflammatory markers ‐ interleukin‐1β (IL‐1β), myeloperoxidase (MPO) activity, and intercellular adhesion molecule‐1 (ICAM‐1), and gastric cytoprotective factors ‐ prostaglandin E2 (PGE2) and heat shock protein 70 (HSP70) were measured. The ulcer group had significantly increased ulcer area, serum MDA, gastric IL‐1β, MPO activity, and ICAM‐1, but decreased serum hydroxyproline and gastric PGE2 levels. Pretreatment with LBPs or C‐PC significantly attenuated the severity of ethanol‐induced gastric mucosal damage, decreased serum MDA, gastric IL‐1β, MPO activity, and ICAM‐1, and increased serum hydroxyproline and gastric HSP70 levels. Pretreatment with a mixture of LBPs and C‐PC had similar effects with pretreatment with LBPs or C‐PC, however, a mixture of LBPs and C‐PC significantly decreased gastric ICAM‐1 levels compared with the ulcer and LBPs‐treated groups, but did not change serum hydroxyproline, gastric MPO activity, and PGE2 levels. Therefore, LBPs and/or C‐PC exert gastroprotective effects on ethanol‐induced gastric ulcer through suppression of lipid peroxidation and gastric inflammation and improvement of cytoprotective mechanisms.Support or Funding InformationThe study is supported by the Ministry of Science and Technology, Taiwan (grant no. MOST105‐2320‐B‐038‐036‐MY3).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Catalytic Activity of the PAH1‐encoded Phosphatidate Phosphatase is Required for Lipid Biosynthesis in the Oleaginous Yarrowia lipolytica
Authors: Carmon Taylor , Ukey Rahul , Fakas Stylianos 
Published: June 2021

The PAH1 gene encodes phosphatidate phosphatase (PAP) which catalyzes the conversion of phosphatidate (PA) to diacylglycerol used for the synthesis of triacylglycerol (TAG). Previous research in our lab showed that the lack of Pah1 (i.e. pah1Δ) in Y. lipolytica causes a significant decrease in cellular lipid content and TAG levels, while the phospholipid levels are increased. However, it is unclear whether this phenotype is due to the loss of the catalytic activity of Pah1 or due to some other function of the protein (e.g. transcriptional regulation). The objective of this work was to confirm that the loss of the catalytic activity of Pah1 is responsible for the phenotypes presented by pah1Δ cells.Yarrowia lipolytica pah1Δ cells expressing either wild‐type Pah1 fused with Green fluorescent protein (GFP) or a catalytically inactive Pah1 (i.e., D350E) fused with GFP were grown in media that favor lipid biosynthesis. PAP activity was measured following the release of water‐soluble 32Pi from chloroform‐soluble [32P] PA, while lipid profiles were analyzed by thin layer chromatography. The expression of the GFP fusions was confirmed by immunoblot analysis using antibodies directed against GFP. The results showed that the pah1Δ strain expressing an inactive Pah1 presented a decrease in TAG levels as well as overall lipid content and an increase in phospholipids compared to the pah1Δ strain expressing the wild‐type Pah1. These results showed that the catalytic activity of Pah1 is required for TAG biosynthesis in Y. lipolytica.Support or Funding InformationThis work was supported, in whole or in part, by National Institutes of Health Grant R15GM124602‐01 from the United States Public Health Service. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The acyltransferase Gpc1 impacts PC molecular species and phenotypic outcomes
Authors: Nikiforov Alexiy , Skinner Brelan , Godshalk Maeve , Patton‐Vogt Jana 
Published: June 2021

Phospholipids are major components of cellular membranes and their biochemical properties, such as fatty acid composition, help define the biophysical properties of membranes. Phosphatidylcholine (PC) is the most abundant phospholipid in cellular membranes and is synthesized primarily by two well defined metabolic pathways in Saccharomyces cerevisiae. Our laboratory recently characterized a novel glycerophosphocholine (GPC) acyltransferase, encoded by GPC1, that provides a third route for PC biosynthesis and is involved in the newly defined PC deacylation‐reacylation remodeling pathway (PC‐DRP). PC‐DRP begins with GPC, the product of complete PC deacylation by phospholipases of the B type. Gpc1 acylates GPC to form lysophosphatidylcholine (LysoPC). LysoPC can subsequently be converted to PC by Ale1. Previous results have shown that Gpc1 prefers the addition of saturated fatty acids during PC remodeling, which results in more saturated PC species and has the potential to influence the biophysical properties of the membrane. To better understand how GPC1 is regulated and to determine its physiological role in the cell, we assessed the effect of GPC1 dosage and temperature alterations on growth, expression, and PC molecular species. Preliminary data indicates that while increasing the temperature from 30°C to 37°C slows growth in a wild type strain, the gpc1Δ mutant is much less effected. As expected, overexpression of GPC1 further negatively impacts growth at 37°C. GPC1 message abundance, as measured by qRT‐PCR, is decreased at 37°C as compared to 30°C in a wild type strain. Other members of PC‐DRP, including ALE1 and PLB1 also display decreased expression upon elevated temperature. Mass spectrometry‐based analysis of the PC molecular species under these conditions are ongoing. Other stressors expected to impact membrane events, including inositol availability, are being examined. These experiments will provide insight into the physiological role of Gpc1.Support or Funding InformationNIH R15 GM104876 (to JPV)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.