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Dunaway LS, Loeb SA, Petrillo S, Tolosano E, Isakson BE. Heme metabolism in nonerythroid cells. J Biol Chem 2024; 300:107132. [PMID: 38432636 PMCID: PMC10988061 DOI: 10.1016/j.jbc.2024.107132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/31/2024] [Accepted: 02/23/2024] [Indexed: 03/05/2024] Open
Abstract
Heme is an iron-containing prosthetic group necessary for the function of several proteins termed "hemoproteins." Erythrocytes contain most of the body's heme in the form of hemoglobin and contain high concentrations of free heme. In nonerythroid cells, where cytosolic heme concentrations are 2 to 3 orders of magnitude lower, heme plays an essential and often overlooked role in a variety of cellular processes. Indeed, hemoproteins are found in almost every subcellular compartment and are integral in cellular operations such as oxidative phosphorylation, amino acid metabolism, xenobiotic metabolism, and transcriptional regulation. Growing evidence reveals the participation of heme in dynamic processes such as circadian rhythms, NO signaling, and the modulation of enzyme activity. This dynamic view of heme biology uncovers exciting possibilities as to how hemoproteins may participate in a range of physiologic systems. Here, we discuss how heme is regulated at the level of its synthesis, availability, redox state, transport, and degradation and highlight the implications for cellular function and whole organism physiology.
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Affiliation(s)
- Luke S Dunaway
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Skylar A Loeb
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Sara Petrillo
- Deptartment Molecular Biotechnology and Health Sciences and Molecular Biotechnology Center "Guido Tarone", University of Torino, Torino, Italy
| | - Emanuela Tolosano
- Deptartment Molecular Biotechnology and Health Sciences and Molecular Biotechnology Center "Guido Tarone", University of Torino, Torino, Italy
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
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2
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Kagan VE, Straub AC, Tyurina YY, Kapralov AA, Hall R, Wenzel SE, Mallampalli RK, Bayir H. Vitamin E/Coenzyme Q-Dependent "Free Radical Reductases": Redox Regulators in Ferroptosis. Antioxid Redox Signal 2024; 40:317-328. [PMID: 37154783 PMCID: PMC10890965 DOI: 10.1089/ars.2022.0154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 03/10/2023] [Accepted: 04/08/2023] [Indexed: 05/10/2023]
Abstract
Significance: Lipid peroxidation and its products, oxygenated polyunsaturated lipids, act as essential signals coordinating metabolism and physiology and can be deleterious to membranes when they accumulate in excessive amounts. Recent Advances: There is an emerging understanding that regulation of polyunsaturated fatty acid (PUFA) phospholipid peroxidation, particularly of PUFA-phosphatidylethanolamine, is important in a newly discovered type of regulated cell death, ferroptosis. Among the most recently described regulatory mechanisms is the ferroptosis suppressor protein, which controls the peroxidation process due to its ability to reduce coenzyme Q (CoQ). Critical Issues: In this study, we reviewed the most recent data in the context of the concept of free radical reductases formulated in the 1980-1990s and focused on enzymatic mechanisms of CoQ reduction in different membranes (e.g., mitochondrial, endoplasmic reticulum, and plasma membrane electron transporters) as well as TCA cycle components and cytosolic reductases capable of recycling the high antioxidant efficiency of the CoQ/vitamin E system. Future Directions: We highlight the importance of individual components of the free radical reductase network in regulating the ferroptotic program and defining the sensitivity/tolerance of cells to ferroptotic death. Complete deciphering of the interactive complexity of this system may be important for designing effective antiferroptotic modalities. Antioxid. Redox Signal. 40, 317-328.
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Affiliation(s)
- Valerian E. Kagan
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental Health and Pharmacology and Chemical Biology and University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Radiation Oncology and Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adam C. Straub
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Yulia Y. Tyurina
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental Health and Pharmacology and Chemical Biology and University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alexandr A. Kapralov
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental Health and Pharmacology and Chemical Biology and University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Robert Hall
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sally E. Wenzel
- Department of Environmental Health and Pharmacology and Chemical Biology and University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rama K. Mallampalli
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Hülya Bayir
- Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, Children's Hospital Neuroscience Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, Columbia University, New York, New York, USA
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3
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Hall R, Yuan S, Wood K, Katona M, Straub AC. Cytochrome b5 reductases: Redox regulators of cell homeostasis. J Biol Chem 2022; 298:102654. [PMID: 36441026 PMCID: PMC9706631 DOI: 10.1016/j.jbc.2022.102654] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
The cytochrome-b5 reductase (CYB5R) family of flavoproteins is known to regulate reduction-oxidation (redox) balance in cells. The five enzyme members are highly compartmentalized at the subcellular level and function as "redox switches" enabling the reduction of several substrates, such as heme and coenzyme Q. Critical insight into the physiological and pathophysiological significance of CYB5R enzymes has been gleaned from several human genetic variants that cause congenital disease and a broad spectrum of chronic human diseases. Among the CYB5R genetic variants, CYB5R3 is well-characterized and deficiency in expression and activity is associated with type II methemoglobinemia, cancer, neurodegenerative disorders, diabetes, and cardiovascular disease. Importantly, pharmacological and genetic-based strategies are underway to target CYB5R3 to circumvent disease onset and mitigate severity. Despite our knowledge of CYB5R3 in human health and disease, the other reductases in the CYB5R family have been understudied, providing an opportunity to unravel critical function(s) for these enzymes in physiology and disease. In this review, we aim to provide the broad scientific community an up-to-date overview of the molecular, cellular, physiological, and pathophysiological roles of CYB5R proteins.
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Affiliation(s)
- Robert Hall
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shuai Yuan
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Katherine Wood
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mate Katona
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Center for Microvascular Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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4
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Armbruster J, Aboouf MA, Gassmann M, Egert A, Schorle H, Hornung V, Schmidt T, Schmid-Burgk JL, Kristiansen G, Bicker A, Hankeln T, Zhu H, Gorr TA. Myoglobin regulates fatty acid trafficking and lipid metabolism in mammary epithelial cells. PLoS One 2022; 17:e0275725. [PMID: 36223378 PMCID: PMC9555620 DOI: 10.1371/journal.pone.0275725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022] Open
Abstract
Myoglobin (MB) is known to bind and deliver oxygen in striated muscles at high expression levels. MB is also expressed at much reduced levels in mammary epithelial cells, where the protein´s function is unclear. In this study, we aim to determine whether MB impacts fatty acid trafficking and facilitates aerobic fatty acid ß-oxidation in mammary epithelial cells. We utilized MB-wildtype versus MB-knockout mice and human breast cancer cells to examine the impact of MB and its oxygenation status on fatty acid metabolism in mouse milk and mammary epithelia. MB deficient cells were generated through CRISPR/Cas9 and TALEN approaches and exposed to various oxygen tensions. Fatty acid profiling of milk and cell extracts were performed along with cell labelling and immunocytochemistry. Our findings show that MB expression in mammary epithelial cells promoted fatty acid oxidation while reducing stearyl-CoA desaturase activity for lipogenesis. In cells and milk product, presence of oxygenated MB significantly elevated indices of limited fatty acid ß-oxidation, i.e., the organelle-bound removal of a C2 moiety from long-chain saturated or monounsaturated fatty acids, thus shifting the composition toward more saturated and shorter fatty acid species. Presence of the globin also increased cytoplasmic fatty acid solubility under normoxia and fatty acid deposition to lipid droplets under severe hypoxia. We conclude that MB can function in mammary epithelia as intracellular O2-dependent shuttle of oxidizable fatty acid substrates. MB's impact on limited oxidation of fatty acids could generate inflammatory mediator lipokines, such as 7-hexadecenoate. Thus, the novel functions of MB in breast epithelia described herein range from controlling fatty acid turnover and homeostasis to influencing inflammatory signalling cascade. Future work is needed to analyse to what extent these novel roles of MB also apply to myocytic cell physiology and malignant cell behaviour, respectively.
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Affiliation(s)
- Julia Armbruster
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Mostafa A. Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Angela Egert
- Institute of Pathology, Department of Developmental Pathology, University Hospital Bonn, Bonn, Germany
| | - Hubert Schorle
- Institute of Pathology, Department of Developmental Pathology, University Hospital Bonn, Bonn, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tobias Schmidt
- Institute of Clinical Chemistry and Clinical Pharmacology, University and University Hospital Bonn, Bonn, Germany
| | - Jonathan L. Schmid-Burgk
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland
| | | | - Anne Bicker
- Institute of Organismic and Molecular Evolution, Molecular and Genome Analysis, Johannes Gutenberg University, Mainz, Germany
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution, Molecular and Genome Analysis, Johannes Gutenberg University, Mainz, Germany
| | - Hao Zhu
- Department of Clinical Laboratory Sciences, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Thomas A. Gorr
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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5
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Yoshihara D, Fujiwara N, Eguchi H, Sakiyama H, Suzuki K. Iron deficiency aggravates DMNQ-induced cytotoxicity via redox cycling in kidney-derived cells. Free Radic Res 2022; 56:544-554. [PMID: 36469660 DOI: 10.1080/10715762.2022.2154668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron, an essential element for most of living organisms, participates in many biological functions. Since iron is redox-active transition metal, it is known that excessive levels stimulate the formation of reactive oxygen species (ROS) and exacerbate cytotoxicity. An iron deficiency is the most common nutritional deficiency disorder in the world (about 30% of the population) and is more common than cases of iron overload. However, the effects of iron deficiency on ROS-induced cytotoxicity and the maintenance of intracellular redox homeostasis are not fully understood. The present study reports on an evaluation of the effects of iron deficiency on cytotoxicity induced by several ROS generators. In contrast to hydrogen peroxide and erastin, the cytotoxicity of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ), a redox cycling agent that induces intracellular superoxide anion formation, was exacerbated by iron deficiency. Cytochrome b5 reductase was identified as a candidate enzyme responsible for the redox cycling of DMNQ under conditions of iron depletion. Moreover, the DMNQ-induced intracellular accumulation of ROS and a decrease in NADH/NAD+ ratios were enhanced by an iron deficiency. These negative changes were found to be ameliorated by overexpressing NAD(P)H:quinone oxidoreductase 1 (NQO1) in kidney-derived cells that originally showed a very low expression of NQO1. These results indicate that NQO1 plays a protective role against redox cycling quinone-mediated cytotoxicity under iron-depleted conditions. This is because NQO1 generates less-toxic hydroquinones via the two-electron reduction of quinones. The collective findings reported herein demonstrate that not only an iron overload but also an iron deficiency exacerbates ROS-mediated cytotoxicity.
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Affiliation(s)
- Daisaku Yoshihara
- Department of Biochemistry, School of Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Noriko Fujiwara
- Department of Biochemistry, School of Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Hironobu Eguchi
- Department of Biochemistry, School of Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Haruhiko Sakiyama
- Department of Biochemistry, School of Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Keiichiro Suzuki
- Department of Biochemistry, School of Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
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Aboouf MA, Armbruster J, Thiersch M, Gassmann M, Gödecke A, Gnaiger E, Kristiansen G, Bicker A, Hankeln T, Zhu H, Gorr TA. Myoglobin, expressed in brown adipose tissue of mice, regulates the content and activity of mitochondria and lipid droplets. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:159026. [PMID: 34384891 DOI: 10.1016/j.bbalip.2021.159026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/19/2022]
Abstract
The identification of novel physiological regulators that stimulate energy expenditure through brown adipose tissue (BAT) activity in substrate catalysis is of utmost importance to understand and treat metabolic diseases. Myoglobin (MB), known to store or transport oxygen in heart and skeletal muscles, has recently been found to bind fatty acids with physiological constants in its oxygenated form (i.e., MBO2). Here, we investigated the in vivo effect of MB expression on BAT activity. In particular, we studied mitochondrial function and lipid metabolism as essential determinants of energy expenditure in this tissue. We show in a MB-null (MBko) mouse model that MB expression in BAT impacts on the activity of brown adipocytes in a twofold manner: i) by elevating mitochondrial density plus maximal respiration capacity, and through that, by stimulating BAT oxidative metabolism along with the organelles` uncoupled respiration; and ii) by influencing the free fatty acids pool towards a palmitate-enriched composition and shifting the lipid droplet (LD) equilibrium towards higher counts of smaller droplets. These metabolic changes were accompanied by the up-regulated expression of thermogenesis markers UCP1, CIDEA, CIDEC, PGC1-α and PPAR-α in the BAT of MB wildtype (MBwt) mice. Along with the emergence of the "browning" BAT morphology, MBwt mice exhibited a leaner phenotype when compared to MBko littermates at 20 weeks of age. Our data shed novel insights into MB's role in linking oxygen and lipid-based thermogenic metabolism. The findings suggest potential new strategies of targeting the MB pathway to treat metabolic disorders related to diminishing energy expenditure.
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Affiliation(s)
- Mostafa A Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Molecular and Translational Biomedicine PhD Program, Life Science Zurich Graduate School, 8057 Zurich, Switzerland; Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, 11566 Cairo, Egypt
| | - Julia Armbruster
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Molecular and Translational Biomedicine PhD Program, Life Science Zurich Graduate School, 8057 Zurich, Switzerland
| | - Markus Thiersch
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Axel Gödecke
- Institute of Cardiovascular Physiology (A.G.), Medical Faculty, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Erich Gnaiger
- Department of Visceral, Transplant and Thoracic Surgery, D. Swarovski Research Laboratory, Medical University Innsbruck, Innrain 66/6, A-6020 Innsbruck, Austria
| | - Glen Kristiansen
- Institute of Pathology, University Hospital Bonn, University of Bonn, D-53127 Bonn, Germany
| | - Anne Bicker
- Institute of Organismic and Molecular Evolution, Molecular Genetics and Genome Analysis, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution, Molecular Genetics and Genome Analysis, Johannes Gutenberg University, D-55099 Mainz, Germany
| | - Hao Zhu
- Department of Clinical Laboratory Sciences, The University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA; Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Thomas A Gorr
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
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Erdogan OS, Tuncer SB, Kilic S, Odemis DA, Turkcan GK, Celik B, Avsar M, Yazici H. Genome-wide methylation profiles in monozygotic twins with discordance for ovarian carcinoma. Oncol Lett 2020; 20:357. [PMID: 33133257 PMCID: PMC7590432 DOI: 10.3892/ol.2020.12221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/19/2020] [Indexed: 12/24/2022] Open
Abstract
Ovarian cancer is a disease that is generally diagnosed at an advanced stage, and has poor survival. Monozygotic (MZ) twins are considered to be good research models for investigating the epigenetic changes associated with diseases. In the present study, the involvement of epigenetic mechanisms in ovarian cancer etiology were evaluated using the MZ twin model. Whole-genome methylation patterns were investigated in a BRCA1 gene mutation-carrying family comprising MZ twins, only one of whom had ovarian cancer, and other healthy siblings. Whole-genome methylation patterns were assessed in peripheral blood DNA using Infinium MethylationEPIC BeadChips on an Illumina iScan device. The hypermethylated and hypomethylated genes were detected between cases and controls in four different comparison groups in order to evaluate the differences in methylation levels according to cancer diagnosis and BRCA mutation status. The obtained results showed that the differential methylations in 12 different genes, namely PR/SET domain 6, cytochrome B5 reductase 4, ZNF714, OR52M1, SEMA4D, CHD1L, CAPZB, clustered mitochondria homolog, RB-binding protein 7, chromatin repair factor, ankyrin repeat domain 23, RIB43A domain with coiled-coils 1 and C6orf227, were associated with ovarian cancer. Biological functional analysis of the genes detected in the study using the PANTHER classification system revealed that they have roles in biological processes including ‘biologic adhesion’, ‘regulation’, ‘cellular components organization’, ‘biogenesis’, ‘immune system functioning’, ‘metabolic functioning’ and ‘localization’. Overall, the present study suggested that epigenetic differences, such as methylation status, could be used as a non-invasive biological markers for the early diagnosis and follow-up of ovarian cancer.
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Affiliation(s)
- Ozge Sukruoglu Erdogan
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Seref Bugra Tuncer
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Seda Kilic
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Demet Akdeniz Odemis
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Gozde Kuru Turkcan
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Betul Celik
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Mukaddes Avsar
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
| | - Hulya Yazici
- Department of Basic Oncology, Cancer Genetics Division, Institute of Oncology, Istanbul University, Istanbul 34093, Turkey
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8
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Stroh MA, Winter MK, McCarson KE, Thyfault JP, Zhu H. NCB5OR Deficiency in the Cerebellum and Midbrain Leads to Dehydration and Alterations in Thirst Response, Fasted Feeding Behavior, and Voluntary Exercise in Mice. THE CEREBELLUM 2019; 17:152-164. [PMID: 28887630 DOI: 10.1007/s12311-017-0880-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cytosolic NADH-cytochrome-b5-oxidoreductase (NCB5OR) is ubiquitously expressed in animal tissues. We have previously reported that global ablation of NCB5OR in mice results in early-onset lean diabetes with decreased serum leptin levels and increased metabolic and feeding activities. The conditional deletion of NCB5OR in the mouse cerebellum and midbrain (conditional knock out, CKO mice) results in local iron dyshomeostasis and altered locomotor activity. It has been established that lesion to or removal of the cerebellum leads to changes in nutrient organization, visceral response, feeding behavior, and body weight. This study assessed whether loss of NCB5OR in the cerebellum and midbrain altered feeding or metabolic activity and had an effect on serum T3, cortisol, prolactin, and leptin levels. Metabolic cage data revealed that 16 week old male CKO mice had elevated respiratory quotients and decreased respiratory water expulsion, decreased voluntary exercise, and altered feeding and drinking behavior compared to wild-type littermate controls. Most notably, male CKO mice displayed higher consumption of food during refeeding after a 48-h fast. Echo MRI revealed normal body composition but decreased total water content and hydration ratios in CKO mice. Increased serum osmolality measurements confirmed the dehydration status of male CKO mice. Serum leptin levels were significantly elevated in male CKO mice while prolactin, T3, and cortisol levels remain unchanged relative to wild-type controls, consistent with elevated transcript levels for leptin receptors (short form) in the male CKO mouse cerebellum. Taken together, these findings suggest altered feeding response post starvation as a result of NCB5OR deficiency in the cerebellum.
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Affiliation(s)
- Matthew A Stroh
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Michelle K Winter
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Kenneth E McCarson
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John P Thyfault
- Department of Molecular Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.,Research Service, Kansas City VA Medical Center, Kansas City, MO, 64128, USA
| | - Hao Zhu
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA. .,Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS, 66160, USA. .,Department of Clinical Laboratory Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 4048G-Eaton, Kansas City, KS, 66160, USA.
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9
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Quinone and nitrofurantoin redox cycling by recombinant cytochrome b5 reductase. Toxicol Appl Pharmacol 2018; 359:102-107. [PMID: 30222979 DOI: 10.1016/j.taap.2018.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 01/05/2023]
Abstract
NADH cytochrome b5 reductase mediates electron transfer from NADH to cytochrome b5 utilizing flavin adenine dinucleotide as a redox cofactor. Reduced cytochrome b5 is an important cofactor in many metabolic reactions including cytochrome P450-mediated xenobiotic metabolism, steroid biosynthesis and fatty acid metabolism, hemoglobin reduction, and methionine and plasmalogen synthesis. Using recombinant human enzyme, we discovered that cytochrome b5 reductase mediates redox cycling of a variety of quinones generating superoxide anion, hydrogen peroxide, and, in the presence of transition metals, hydroxyl radicals. Redox cycling activity was oxygen-dependent and preferentially utilized NADH as a co-substrate; NADH was 5-10 times more active than NADPH in supporting redox cycling. Redox cycling activity was greatest for 9,10-phenanthrenequinone and 1,2-naphthoquinone, followed by 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone (menadione), nitrofurantoin and 2-hydroxyestradiol. Using menadione as the substrate, quinone redox cycling was found to inhibit reduction of cytochrome b5 by cytochrome b5 reductase, as measured by heme spectral changes in cytochrome b5. Under anaerobic conditions where redox cycling is inhibited, menadione had no effect on the reduction of cytochrome b5. Chemical redox cycling by cytochrome b5 reductase may be important in generating cytotoxic reactive oxygen species in target tissues. This activity, together with the inhibition of cytochrome b5 reduction by redox-active chemicals and consequent deficiencies in available cellular cytochrome b5, are likely to contribute to tissue injury following exposure to quinones and related redox active chemicals.
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10
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Mukherjee A, Adhikari A, Das P, Biswas S, Mukherjee S, Adak S. Loss of virulence in NAD(P)H cytochrome b5 oxidoreductase deficient Leishmania major. Biochem Biophys Res Commun 2018; 503:371-377. [PMID: 29906460 DOI: 10.1016/j.bbrc.2018.06.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 06/09/2018] [Indexed: 11/28/2022]
Abstract
Leishmania promastigotes have the ability to synthesize essential polyunsaturated fatty acids de novo and can grow in lipid free media. Recently, we have shown that NAD(P)H cytochrome b5 oxidoreductase (Ncb5or) enzyme in Leishmania acts as the redox partner for Δ12 fatty acid desaturase, which catalyses the conversion of oleate to linoleate. So far, the exact role of Leishmania derived linoleate synthesis is still incomplete in the literature. The viability assay by flow cytometry as well as microscopic studies suggests that linoleate is an absolute requirement for Leishmania promastigote survival in delipidated media. Western blot analysis suggested that infection with log phase linoleate deficient mutant (KO) results in increased level of NF-κBp65, IκB and IKKβ phosphorylation in RAW264.7 cells. Similarly, the log phase KO infected RAW264.7 cells show dramatic increment of COX-2 expression and TNF-α secretion, compared to control or Ncb5or complement (CM) cell lines. The activation of inflammatory signaling pathways by KO mutant is significantly reduced when the RAW264.7 cells are pre-treated with BSA bound linoleate. Together, these findings confirmed that the leishmanial linoleate inhibits both COX-2 and TNF-α expression in macrophage via the inactivation of NF-κB signaling pathway. The stationary phase of KO promastigotes shows avirulence after infection in macrophages as well as inoculation into BALB/c mice; whereas CM cell lines show virulence. Collectively, these data provide strong evidence that de novo linoleate synthesis in Leishmania is an essential for parasite survival at extracellular promastigote stage as well as intracellular amastigote stage.
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Affiliation(s)
- Aditi Mukherjee
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Ayan Adhikari
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Priya Das
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Saroj Biswas
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Supratim Mukherjee
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Subrata Adak
- From the Division of Structural Biology & Bio-informatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India.
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11
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He B, Zhang J, Wang Y, Li Y, Zou X, Liang B. Identification of cytochrome b5 CYTB-5.1 and CYTB-5.2 in C. elegans; evidence for differential regulation of SCD. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1863:235-246. [PMID: 29237573 DOI: 10.1016/j.bbalip.2017.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 12/02/2017] [Accepted: 12/07/2017] [Indexed: 01/04/2023]
Abstract
Unsaturated fatty acids (UFAs) play crucial roles in living organisms regarding development, energy metabolism, stress resistance, etc. The biosynthesis of UFAs starts from the introduction of the first double bond by stearoyl-CoA desaturase (SCD), converting saturated fatty acids (SFAs) to monounsaturated fatty acids (MUFAs). This desaturation is considered to be an aerobic process that requires cytochrome b5 reductase, cytochrome b5 and SCD. However, this enzyme system remains elusive in Caenorhabditis elegans. Here, we show that inactivation by RNAi knockdown or mutation (gk442189) of putative cytochrome b5 genes cytb-5.1 led to reduced conversion of C18:0 to C18:1(n-9) by SCD desaturases FAT-6/7 in C. elegans. On the contrary, cytb-5.2RNAi and cytb-5.2(gk113588) mutant worms showed decreased conversion of C16:0 to C16:1(n-7) by FAT-5 desaturase. Dietary supplementation with C18:1(n-9) and C18:2(n-6) also showed that CYTB-5.1 is likely required for the activity of FAT-6/7 desaturases, but not for FAT-1 to FAT-4 desaturases. Interestingly, co-immunoprecipitation (Co-IP) demonstrated that either FAT-7 or FAT-5 has ability to interact with both CYTB-5.1 and CYTB-5.2. Moreover, RNAi knockdown of cytb-5.1 upregulates the transcriptional and translational expression of fat-5 to fat-7, which may be due to the feedback induction by reduced C18:1(n-9) and downstream fatty acids. Furthermore, both CYTB-5.1 and CYTB-5.2 are involved in fat accumulation, fertility and lifespan in worms, which may be independent of changes in fatty acid compositions. Collectively, these findings for the first time reveal the differential regulation of various SCDs by distinct cytochrome b5 CYTB-5.1 and CYTB-5.2 in the biosynthesis of UFAs in C. elegans.
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Affiliation(s)
- Baoshen He
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Jingjing Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Department of Hepatobiliary Surgery, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, China
| | - Yanli Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Yamei Li
- School of Life Sciences, University of Science and Technology of China, Hefei 230036, China
| | - Xiaoju Zou
- Department of Life Science and Biotechnology, Key Laboratory of Special Biological Resource Development and Utilization of University in Yunnan Province, Kunming University, Kunming 650214, China.
| | - Bin Liang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Department of Hepatobiliary Surgery, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, China.
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12
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Wang P, Zhu BT. Unique effect of 4-hydroxyestradiol and its methylation metabolites on lipid and cholesterol profiles in ovariectomized female rats. Eur J Pharmacol 2017; 800:107-117. [PMID: 28219710 DOI: 10.1016/j.ejphar.2017.02.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 02/14/2017] [Accepted: 02/17/2017] [Indexed: 10/20/2022]
Abstract
Animal studies have shown that endogenous estrogens such as 17β-estradiol (E2) can modulate lipid profiles in vivo, and this effect is generally thought to be mediated by the estrogen receptors (ERs). The present study sought to test a hypothesis that some of the endogenous estrogen metabolites that have very weak estrogenic activity may exert some of their modulating effects on lipid metabolism in an ER-independent manner. Using ovariectomized female rats as an in vivo model, we found that 4-hydroxyestradiol (4-OH-E2) has a markedly stronger effect in reducing the adipocyte size and serum cholesterol level in rats compared to E2, despite the weaker estrogenic activity of 4-OH-E2. Moreover, when E2 or 4-OH-E2 is used in combination with ICI-182,780 (an ER antagonist), some of their lipid-modulating effects are not blocked by this antiestrogen. Interestingly, two of the O-methylation metabolites of 4-OH-E2, namely, 4-methoxyestradiol and 4-methoxyestrone, which have much weaker estrogenic activity, were also found to have similar lipid-modulating effects compared to 4-OH-E2. Mechanistically, up-regulation of the expression of leptin, cytochrome P450 7A1 and LXRα genes is observed in the liver of animals treated with E2 or 4-OH-E2, and the up-regulation is essentially not inhibited by co-treatment with ICI-182,780. These results demonstrate that some of the endogenous E2 metabolites are functionally important modulators of lipid metabolic profiles in vivo. In addition, our findings indicate that an ER-independent pathway likely mediates some of the lipid-modulating effects of endogenous estrogens and their metabolic derivatives.
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Affiliation(s)
- Pan Wang
- Department of Pharmacology, Toxicology and Therapeutics, School of Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA; Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bao-Ting Zhu
- Department of Pharmacology, Toxicology and Therapeutics, School of Medicine, The University of Kansas Medical Center, Kansas City, KS 66160, USA; School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong 518172, China.
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13
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Stroh MA, Winter MK, Swerdlow RH, McCarson KE, Zhu H. Loss of NCB5OR in the cerebellum disturbs iron pathways, potentiates behavioral abnormalities, and exacerbates harmaline-induced tremor in mice. Metab Brain Dis 2016; 31:951-64. [PMID: 27188291 PMCID: PMC5929129 DOI: 10.1007/s11011-016-9834-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/01/2016] [Indexed: 12/13/2022]
Abstract
Iron dyshomeostasis has been implicated in many diseases, including a number of neurological conditions. Cytosolic NADH cytochrome b5 oxidoreductase (NCB5OR) is ubiquitously expressed in animal tissues and is capable of reducing ferric iron in vitro. We previously reported that global gene ablation of NCB5OR resulted in early-onset diabetes and altered iron homeostasis in mice. To further investigate the specific effects of NCB5OR deficiency on neural tissue without contributions from known phenotypes, we generated a conditional knockout (CKO) mouse that lacks NCB5OR only in the cerebellum and midbrain. Assessment of molecular markers in the cerebellum of CKO mice revealed changes in pathways associated with cellular and mitochondrial iron homeostasis. (59)Fe pulse-feeding experiments revealed cerebellum-specific increased or decreased uptake of iron by 7 and 16 weeks of age, respectively. Additionally, we characterized behavioral changes associated with loss of NCB5OR in the cerebellum and midbrain in the context of dietary iron deprivation-evoked generalized iron deficiency. Locomotor activity was reduced and complex motor task execution was altered in CKO mice treated with an iron deficient diet. A sucrose preference test revealed that the reward response was intact in CKO mice, but that iron deficient diet consumption altered sucrose preference in all mice. Detailed gait analysis revealed locomotor changes in CKO mice associated with dysfunctional proprioception and locomotor activation independent of dietary iron deficiency. Finally, we demonstrate that loss of NCB5OR in the cerebellum and midbrain exacerbated harmaline-induced tremor activity. Our findings suggest an essential role for NCB5OR in maintaining both iron homeostasis and the proper functioning of various locomotor pathways in the mouse cerebellum and midbrain.
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Affiliation(s)
- Matthew A Stroh
- Landon Center on Aging, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 1005, Kansas City, KS, 66160, USA
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3030, Kansas City, KS, 66160, USA
- Neuroscience Graduate Program, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3038, Kansas City, KS, 66160, USA
| | - Michelle K Winter
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3051, Kansas City, KS, 66160, USA
| | - Russell H Swerdlow
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3030, Kansas City, KS, 66160, USA
- Neuroscience Graduate Program, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3038, Kansas City, KS, 66160, USA
- Department of Neurology, University of Kansas Medical Center, 3599 Rainbow Blvd., MSN 2012, Kansas City, KS, 66160, USA
| | - Kenneth E McCarson
- Kansas Intellectual and Developmental Disabilities Research Center, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3051, Kansas City, KS, 66160, USA
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 1018, Kansas City, KS, 66160, USA
| | - Hao Zhu
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3030, Kansas City, KS, 66160, USA.
- Neuroscience Graduate Program, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 3038, Kansas City, KS, 66160, USA.
- Department of Clinical Laboratory Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., MSN 4048G-Eaton, Kansas City, KS, 66160, USA.
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14
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Chronic Glutathione Depletion Confers Protection against Alcohol-induced Steatosis: Implication for Redox Activation of AMP-activated Protein Kinase Pathway. Sci Rep 2016; 6:29743. [PMID: 27403993 PMCID: PMC4940737 DOI: 10.1038/srep29743] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/22/2016] [Indexed: 12/19/2022] Open
Abstract
The pathogenesis of alcoholic liver disease (ALD) is not well established. However, oxidative stress and associated decreases in levels of glutathione (GSH) are known to play a central role in ALD. The present study examines the effect of GSH deficiency on alcohol-induced liver steatosis in Gclm knockout (KO) mice that constitutively have ≈15% normal hepatic levels of GSH. Following chronic (6 week) feeding with an ethanol-containing liquid diet, the Gclm KO mice were unexpectedly found to be protected against steatosis despite showing increased oxidative stress (as reflected in elevated levels of CYP2E1 and protein carbonyls). Gclm KO mice also exhibit constitutive activation of liver AMP-activated protein kinase (AMPK) pathway and nuclear factor-erythroid 2–related factor 2 target genes, and show enhanced ethanol clearance, altered hepatic lipid profiles in favor of increased levels of polyunsaturated fatty acids and concordant changes in expression of genes associated with lipogenesis and fatty acid oxidation. In summary, our data implicate a novel mechanism protecting against liver steatosis via an oxidative stress adaptive response that activates the AMPK pathway. We propose redox activation of the AMPK may represent a new therapeutic strategy for preventing ALD.
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15
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Martin-Montalvo A, Sun Y, Diaz-Ruiz A, Ali A, Gutierrez V, Palacios HH, Curtis J, Siendones E, Ariza J, Abulwerdi GA, Sun X, Wang AX, Pearson KJ, Fishbein KW, Spencer RG, Wang M, Han X, Scheibye-Knudsen M, Baur JA, Shertzer HG, Navas P, Villalba JM, Zou S, Bernier M, de Cabo R. Cytochrome b5 reductase and the control of lipid metabolism and healthspan. NPJ Aging Mech Dis 2016; 2:16006. [PMID: 28721264 PMCID: PMC5515006 DOI: 10.1038/npjamd.2016.6] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/02/2015] [Accepted: 12/09/2015] [Indexed: 12/26/2022] Open
Abstract
Cytochrome b5 reductases (CYB5R) are required for the elongation and desaturation of fatty acids, cholesterol synthesis and mono-oxygenation of cytochrome P450 enzymes, all of which are associated with protection against metabolic disorders. However, the physiological role of CYB5R in the context of metabolism, healthspan and aging remains ill-defined. We generated CYB5R-overexpressing flies (CYB5R-OE) and created a transgenic mouse line overexpressing CYB5R3 (CYB5R3-Tg) in the C57BL/6J background to investigate the function of this class of enzymes as regulators of metabolism and age-associated pathologies. Gender- and/or stage-specific induction of CYB5R, and pharmacological activation of CYB5R with tetrahydroindenoindole extended fly lifespan. Increased expression of CYB5R3 was associated with significant improvements in several metabolic parameters that resulted in modest lifespan extension in mice. Diethylnitrosamine-induced liver carcinogenesis was reduced in CYB5R3-Tg mice. Accumulation of high levels of long-chain polyunsaturated fatty acids, improvement in mitochondrial function, decrease in oxidative damage and inhibition of chronic pro-inflammatory pathways occurred in the transgenic animals. These results indicate that CYB5R represents a new target in the study of genes that regulate lipid metabolism and healthspan.
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Affiliation(s)
- Alejandro Martin-Montalvo
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Yaning Sun
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Alberto Diaz-Ruiz
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Ahmed Ali
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Vincent Gutierrez
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Hector H Palacios
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Jessica Curtis
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Emilio Siendones
- Centro Andaluz de Biología del Desarrollo, and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC, Sevilla, Spain
| | - Julia Ariza
- Departamento de Biología Celular, Fisiología e Inmunología, Facultad de Ciencias, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Gelareh A Abulwerdi
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Xiaoping Sun
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Annie X Wang
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kevin J Pearson
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.,Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Kenneth W Fishbein
- Magnetic Resonance Imaging and Spectroscopy Section, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Richard G Spencer
- Magnetic Resonance Imaging and Spectroscopy Section, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Miao Wang
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL, USA
| | - Xianlin Han
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL, USA
| | - Morten Scheibye-Knudsen
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Joe A Baur
- Department of Physiology, Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, PA, USA
| | - Howard G Shertzer
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Placido Navas
- Centro Andaluz de Biología del Desarrollo, and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC, Sevilla, Spain
| | - Jose Manuel Villalba
- Departamento de Biología Celular, Fisiología e Inmunología, Facultad de Ciencias, Universidad de Córdoba, Campus de Excelencia Internacional Agroalimentario, Córdoba, Spain
| | - Sige Zou
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Michel Bernier
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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16
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The cytochrome b5 reductase HPO-19 is required for biosynthesis of polyunsaturated fatty acids in Caenorhabditis elegans. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:310-9. [PMID: 26806391 DOI: 10.1016/j.bbalip.2016.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/13/2015] [Accepted: 01/17/2016] [Indexed: 11/23/2022]
Abstract
Polyunsaturated fatty acids (PUFAs) are fatty acids with backbones containing more than one double bond, which are introduced by a series of desaturases that insert double bonds at specific carbon atoms in the fatty acid chain. It has been established that desaturases need flavoprotein-NADH-dependent cytochrome b5 reductase (simplified as cytochrome b5 reductase) and cytochrome b5 to pass through electrons for activation. However, it has remained unclear how this multi-enzyme system works for distinct desaturases. The model organism Caenorhabditis elegans contains seven desaturases (FAT-1, -2, -3, -4, -5, -6, -7) for the biosynthesis of PUFAS, providing an excellent model in which to characterize different desaturation reactions. Here, we show that RNAi inactivation of predicted cytochrome b5 reductases hpo-19 and T05H4.4 led to increased levels of C18:1n-9 but decreased levels of PUFAs, small lipid droplets, decreased fat accumulation, reduced brood size and impaired development. Dietary supplementation with different fatty acids showed that HPO-19 and T05H4.4 likely affect the activity of FAT-1, FAT-2, FAT-3, and FAT-4 desaturases, suggesting that these four desaturases use the same cytochrome b5 reductase to function. Collectively, these findings indicate that cytochrome b5 reductase HPO-19/T05H4.4 is required for desaturation to biosynthesize PUFAs in C. elegans.
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17
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Xu M, Palmer AK, Ding H, Weivoda MM, Pirtskhalava T, White TA, Sepe A, Johnson KO, Stout MB, Giorgadze N, Jensen MD, LeBrasseur NK, Tchkonia T, Kirkland JL. Targeting senescent cells enhances adipogenesis and metabolic function in old age. eLife 2015; 4:e12997. [PMID: 26687007 PMCID: PMC4758946 DOI: 10.7554/elife.12997] [Citation(s) in RCA: 392] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/18/2015] [Indexed: 12/22/2022] Open
Abstract
Senescent cells accumulate in fat with aging. We previously found genetic clearance of senescent cells from progeroid INK-ATTAC mice prevents lipodystrophy. Here we show that primary human senescent fat progenitors secrete activin A and directly inhibit adipogenesis in non-senescent progenitors. Blocking activin A partially restored lipid accumulation and expression of key adipogenic markers in differentiating progenitors exposed to senescent cells. Mouse fat tissue activin A increased with aging. Clearing senescent cells from 18-month-old naturally-aged INK-ATTAC mice reduced circulating activin A, blunted fat loss, and enhanced adipogenic transcription factor expression within 3 weeks. JAK inhibitor suppressed senescent cell activin A production and blunted senescent cell-mediated inhibition of adipogenesis. Eight weeks-treatment with ruxolitinib, an FDA-approved JAK1/2 inhibitor, reduced circulating activin A, preserved fat mass, reduced lipotoxicity, and increased insulin sensitivity in 22-month-old mice. Our study indicates targeting senescent cells or their products may alleviate age-related dysfunction of progenitors, adipose tissue, and metabolism. DOI:http://dx.doi.org/10.7554/eLife.12997.001 The likelihood of developing metabolic diseases such as diabetes increases with age. This is, in part, because the cells within fat and other tissues become less sensitive to the hormone insulin as people and other animals get older. Also, the stem cells that give rise to new, insulin-responsive fat cells become dysfunctional with increasing age. This is related to the accumulation of “senescent” cells, which, unlike normal fat cell progenitors, release molecules that are toxic to nearby and distant cells. Xu, Palmer et al. have now investigated if senescent cells interfere with the activity of stem cells from human fat tissue, and if getting rid of these senescent cells might restore the normal activity and insulin responsiveness of aged fat tissue. The experiments revealed that human senescent fat cell progenitors release a protein called activin A, which impedes the normal function of stem cells and fat tissue. Additionally, older mice had higher levels of activin A in both their blood and fat tissue than young mice. Xu, Palmer et al. then analyzed older mice that had been engineered to have senescent fat cells that could be triggered to essentially kill themselves when the mice were treated with a drug. Eliminating the senescent cells from these mice led to lower levels of activin A and more fat tissue (due to improved stem cell capacity to become fully functional fat cells) that expressed genes required for insulin responsiveness. This showed that senescent cells are a cause of age-related fat tissue loss and metabolic disease in older mice. Next, Xu, Palmer et al. treated older mice with drugs called JAK inhibitors, which they found reduce the production of activin A by senescent cells isolated from fat tissue. After two months of treatment, the levels of activin A in the blood and in fat tissue were indeed reduced. The fat tissue in treated mice also showed fewer features associated with the development of diabetes than the fat tissue of untreated mice. As such, these results paralleled those after selectively eliminating the senescent cells. Together these findings suggest that JAK inhibitors or drugs (called senolytics) that selectively eliminate senescent cells may have clinical benefits in treating age-related conditions such as diabetes and stem cell dysfunction. DOI:http://dx.doi.org/10.7554/eLife.12997.002
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Affiliation(s)
- Ming Xu
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Allyson K Palmer
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Husheng Ding
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Megan M Weivoda
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Tamar Pirtskhalava
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Thomas A White
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Anna Sepe
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Kurt O Johnson
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Michael B Stout
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Nino Giorgadze
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Michael D Jensen
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Nathan K LeBrasseur
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - Tamar Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
| | - James L Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, United States
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18
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Stroh M, Swerdlow RH, Zhu H. Common defects of mitochondria and iron in neurodegeneration and diabetes (MIND): a paradigm worth exploring. Biochem Pharmacol 2014; 88:573-83. [PMID: 24361914 PMCID: PMC3972369 DOI: 10.1016/j.bcp.2013.11.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 12/19/2022]
Abstract
A popular, if not centric, approach to the study of an event is to first consider that of the simplest cause. When dissecting the underlying mechanisms governing idiopathic diseases, this generally takes the form of an ab initio genetic approach. To date, this genetic 'smoking gun' has remained elusive in diabetes mellitus and for many affected by neurodegenerative diseases. With no single gene, or even subset of genes, conclusively causative in all cases, other approaches to the etiology and treatment of these diseases seem reasonable, including the correlation of a systems' predisposed sensitivity to particular influence. In the cases of diabetes mellitus and neurodegenerative diseases, overlapping themes of mitochondrial influence or dysfunction and iron dyshomeostasis are apparent and relatively consistent. This mini-review discusses the influence of mitochondrial function and iron homeostasis on diabetes mellitus and neurodegenerative disease, namely Alzheimer's disease. Also discussed is the incidence of diabetes accompanied by neuropathy and neurodegeneration along with neurodegenerative disorders prone to development of diabetes. Mouse models containing multiple facets of this overlap are also described alongside current molecular trends attributed to both diseases. As a way of approaching the idiopathic and complex nature of these diseases we are proposing the consideration of a MIND (mitochondria, iron, neurodegeneration, and diabetes) paradigm in which systemic metabolic influence, iron homeostasis, and respective genetic backgrounds play a central role in the development of disease.
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Affiliation(s)
- Matthew Stroh
- Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - Hao Zhu
- Neuroscience Graduate Program, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Clinical Laboratory Sciences, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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19
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Song H, Wohltmann M, Tan M, Ladenson JH, Turk J. Group VIA phospholipase A2 mitigates palmitate-induced β-cell mitochondrial injury and apoptosis. J Biol Chem 2014; 289:14194-210. [PMID: 24648512 DOI: 10.1074/jbc.m114.561910] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Palmitate (C16:0) induces apoptosis of insulin-secreting β-cells by processes that involve generation of reactive oxygen species, and chronically elevated blood long chain free fatty acid levels are thought to contribute to β-cell lipotoxicity and the development of diabetes mellitus. Group VIA phospholipase A2 (iPLA2β) affects β-cell sensitivity to apoptosis, and here we examined iPLA2β effects on events that occur in β-cells incubated with C16:0. Such events in INS-1 insulinoma cells were found to include activation of caspase-3, expression of stress response genes (C/EBP homologous protein and activating transcription factor 4), accumulation of ceramide, loss of mitochondrial membrane potential, and apoptosis. All of these responses were blunted in INS-1 cells that overexpress iPLA2β, which has been proposed to facilitate repair of oxidized mitochondrial phospholipids, e.g. cardiolipin (CL), by excising oxidized polyunsaturated fatty acid residues, e.g. linoleate (C18:2), to yield lysophospholipids, e.g. monolysocardiolipin (MLCL), that can be reacylated to regenerate the native phospholipid structures. Here the MLCL content of mouse pancreatic islets was found to rise with increasing iPLA2β expression, and recombinant iPLA2β hydrolyzed CL to MLCL and released oxygenated C18:2 residues from oxidized CL in preference to native C18:2. C16:0 induced accumulation of oxidized CL species and of the oxidized phospholipid (C18:0/hydroxyeicosatetraenoic acid)-glycerophosphoethanolamine, and these effects were blunted in INS-1 cells that overexpress iPLA2β, consistent with iPLA2β-mediated removal of oxidized phospholipids. C16:0 also induced iPLA2β association with INS-1 cell mitochondria, consistent with a role in mitochondrial repair. These findings indicate that iPLA2β confers significant protection of β-cells against C16:0-induced injury.
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Affiliation(s)
- Haowei Song
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Mary Wohltmann
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Min Tan
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Jack H Ladenson
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - John Turk
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
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20
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Zámbó V, Simon-Szabó L, Szelényi P, Kereszturi &E, Bánhegyi G, Csala M. Lipotoxicity in the liver. World J Hepatol 2013; 5:550-557. [PMID: 24179614 PMCID: PMC3812457 DOI: 10.4254/wjh.v5.i10.550] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/27/2013] [Accepted: 10/16/2013] [Indexed: 02/06/2023] Open
Abstract
Obesity due to excessive food intake and the lack of physical activity is becoming one of the most serious public health problems of the 21st century. With the increasing prevalence of obesity, non-alcoholic fatty liver disease is also emerging as a pandemic. While previously this pathophysiological condition was mainly attributed to triglyceride accumulation in hepatocytes, recent data show that the development of oxidative stress, lipid peroxidation, cell death, inflammation and fibrosis are mostly due to accumulation of fatty acids, and the altered composition of membrane phospholipids. In fact, triglyceride accumulation might play a protective role, and the higher toxicity of saturated or trans fatty acids seems to be the consequence of a blockade in triglyceride synthesis. Increased membrane saturation can profoundly disturb cellular homeostasis by impairing the function of membrane receptors, channels and transporters. However, it also induces endoplasmic reticulum stress via novel sensing mechanisms of the organelle’s stress receptors. The triggered signaling pathways in turn largely contribute to the development of insulin resistance and apoptosis. These findings have substantiated the lipotoxic liver injury hypothesis for the pathomechanism of hepatosteatosis. This minireview focuses on the metabolic and redox aspects of lipotoxicity and lipoapoptosis, with special regards on the involvement of endoplasmic reticulum stress responses.
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21
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Rowlan JS, Li Q, Manichaikul A, Wang Q, Matsumoto AH, Shi W. Atherosclerosis susceptibility Loci identified in an extremely atherosclerosis-resistant mouse strain. J Am Heart Assoc 2013; 2:e000260. [PMID: 23938286 PMCID: PMC3828785 DOI: 10.1161/jaha.113.000260] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background C3H/HeJ (C3H) mice are extremely resistant to atherosclerosis, especially males. To understand the underlying genetic basis, we performed quantitative trait locus (QTL) analysis on a male F2 (the second generation from an intercross between 2 inbred strains) cohort derived from an intercross between C3H and C57BL/6 (B6) apolipoprotein E–deficient (Apoe−/−) mice. Methods and Results Two hundred forty‐six male F2 mice were started on a Western diet at 8 weeks of age and kept on the diet for 5 weeks. Atherosclerotic lesions in the aortic root and fasting plasma lipid levels were measured. One hundred thirty‐four microsatellite markers across the entire genome were genotyped. Four significant QTLs on chromosomes (Chr) 2, 4, 9, and 15 and 4 suggestive loci on Chr1, Chr4, and Chr7 were identified for atherosclerotic lesions. Unexpectedly, the C3H allele was associated with increased lesion formation for 2 of the 4 significant QTLs. Six loci for high‐density lipoprotein (HDL), 6 for non‐HDL cholesterol, and 3 for triglycerides were also identified. The QTL for atherosclerosis on Chr9 replicated Ath29, originally mapped in a female F2 cohort derived from B6 and C3H Apoe−/− mice. This locus coincided with a QTL for HDL, and there was a moderate, but statistically significant, correlation between atherosclerotic lesion sizes and plasma HDL cholesterol levels in F2 mice. Conclusions These data indicate that most atherosclerosis susceptibility loci are distinct from those for plasma lipids except for the Chr9 locus, which exerts effect through interactions with HDL.
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Affiliation(s)
- Jessica S. Rowlan
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA (J.S.R., Q.L., Q.W., A.H.M., W.S.)
| | - Qiongzhen Li
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA (J.S.R., Q.L., Q.W., A.H.M., W.S.)
| | - Ani Manichaikul
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA (A.M.)
| | - Qian Wang
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA (J.S.R., Q.L., Q.W., A.H.M., W.S.)
| | - Alan H. Matsumoto
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA (J.S.R., Q.L., Q.W., A.H.M., W.S.)
| | - Weibin Shi
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA (J.S.R., Q.L., Q.W., A.H.M., W.S.)
- Department Biochemistry & Molecular Genetics, University of Virginia, Charlottesville, VA (W.S.)
- Correspondence to: Weibin Shi, University of Virginia, Box 801339, Snyder 266, 480 Ray C Hunt Drive, Charlottesville, VA 22908. E‐mail:
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22
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Brehm MA, Powers AC, Shultz LD, Greiner DL. Advancing animal models of human type 1 diabetes by engraftment of functional human tissues in immunodeficient mice. Cold Spring Harb Perspect Med 2013; 2:a007757. [PMID: 22553498 DOI: 10.1101/cshperspect.a007757] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Despite decades of studying rodent models of type 1 diabetes (T1D), no therapy capable of preventing or curing T1D has successfully been translated from rodents to humans. This inability to translate otherwise promising therapies to clinical settings likely resides, to a major degree, from significant species-specific differences between rodent and human immune systems as well as species-related variances in islets in terms of their cellular composition, function, and gene expression. Indeed, taken collectively, these differences underscore the need to define interactions between the human immune system with human β cells. Immunodeficient mice engrafted with human immune systems and human β cells represent an interesting and promising opportunity to study these components in vivo. To meet this need, years of effort have been extended to develop mice depleted of undesirable components while at the same time, allowing the introduction of constituents necessary to recapitulate physiological settings as near as possible to human T1D. With this, these so-called "humanized mice" are currently being used as a preclinical bridge to facilitate identification and translation of novel discoveries to clinical settings.
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Affiliation(s)
- Michael A Brehm
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, USA
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23
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Kálmán FS, Lizák B, Nagy SK, Mészáros T, Zámbó V, Mandl J, Csala M, Kereszturi E. Natural mutations lead to enhanced proteasomal degradation of human Ncb5or, a novel flavoheme reductase. Biochimie 2013; 95:1403-10. [PMID: 23523930 DOI: 10.1016/j.biochi.2013.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 03/08/2013] [Indexed: 01/12/2023]
Abstract
NADH cytochrome b5 oxidoreductase (Ncb5or) protects β-cells against oxidative stress and lipotoxicity. The predominant phenotype of lean Ncb5or-null mouse is insulin-dependent diabetes due to β-cell death. This suggests the putative role of NCB5OR polymorphism in human diabetes. Therefore, we aimed to investigate the effect of natural missense mutations on the expression of human NCB5OR. Protein and mRNA levels of five non-synonymous coding variants were analyzed in transfected HEK293 and HepG2 cells. Although the mRNA levels were only slightly affected by the mutations, the amount of Ncb5or protein was largely reduced upon two Glu to Gly replacements in the third exon (p.E87G, p.E93G). These two mutations remarkably and synergistically shortened the half-life of Ncb5or and their effect could be attenuated by proteasome inhibitors. Our results strongly indicate that p.E87G, p.E93G mutations lead to enhanced proteasomal degradation due to manifest conformational alterations in the b5 domain. These data provide first evidence for natural mutations in NCB5OR gene resulting in decreased protein levels and hence having potential implications in human pathology.
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Affiliation(s)
- Fanni S Kálmán
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, POB 260, 1444 Budapest, Hungary.
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Vazquez-Chantada M, Gonzalez-Lahera A, Martinez-Arranz I, Garcia-Monzon C, Regueiro MM, Garcia-Rodriguez JL, Schlangen KA, Mendibil I, Rodriguez-Ezpeleta N, Lozano JJ, Banasik K, Justesen JM, Joergensen T, Witte DR, Lauritzen T, Hansen T, Pedersen O, Veyrie N, Clement K, Tordjman J, Tran A, Le Marchand-Brustel Y, Buque X, Aspichueta P, Echevarria-Uraga JJ, Martin-Duce A, Caballeria J, Gual P, Castro A, Mato JM, Martinez-Chantar ML, Aransay AM. Solute carrier family 2 member 1 is involved in the development of nonalcoholic fatty liver disease. Hepatology 2013; 57:505-14. [PMID: 22961556 DOI: 10.1002/hep.26052] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 08/06/2012] [Indexed: 01/01/2023]
Abstract
UNLABELLED Susceptibility to develop nonalcoholic fatty liver disease (NAFLD) has genetic bases, but the associated variants are uncertain. The aim of the present study was to identify genetic variants that could help to prognose and further understand the genetics and development of NAFLD. Allele frequencies of 3,072 single-nucleotide polymorphisms (SNPs) in 92 genes were characterized in 69 NAFLD patients and 217 healthy individuals. The markers that showed significant allele-frequency differences in the pilot groups were subsequently studied in 451 NAFLD patients and 304 healthy controls. Besides this, 4,414 type 2 diabetes mellitus (T2DM) cases and 4,567 controls were genotyped. Liver expression of the associated gene was measured and the effect of its potential role was studied by silencing the gene in vitro. Whole genome expression, oxidative stress (OS), and the consequences of oleic acid (OA)-enriched medium on lipid accumulation in siSLC2A1-THLE2 cells were studied by gene-expression analysis, dihydroethidium staining, BODIPY, and quantification of intracellular triglyceride content, respectively. Several SNPs of SLC2A1 (solute carrier family 2 [facilitated glucose transporter] member 1) showed association with NAFLD, but not with T2DM, being the haplotype containing the minor allele of SLC2A1 sequence related to the susceptibility to develop NAFLD. Gene-expression analysis demonstrated a significant down-regulation of SLC2A1 in NAFLD livers. Enrichment functional analyses of transcriptome profiles drove us to demonstrate that in vitro silencing of SLC2A1 induces an increased OS activity and a higher lipid accumulation under OA treatment. CONCLUSIONS Genetic variants of SLC2A1 are associated with NAFLD, and in vitro down-regulation of this gene promotes lipid accumulation. Moreover, the oxidative response detected in siSLC2A1-THLE2 cells corroborated the antioxidant properties previously related to this gene and linked the most representative clinical characteristics of NAFLD patients: oxidative injury and increased lipid storage.
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Affiliation(s)
- Mercedes Vazquez-Chantada
- CIC bioGUNE, Centro de Investigación Biomédica en red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Spain
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25
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Mukherjee S, Sen Santara S, Das S, Bose M, Roy J, Adak S. NAD(P)H cytochrome b5 oxidoreductase deficiency in Leishmania major results in impaired linoleate synthesis followed by increased oxidative stress and cell death. J Biol Chem 2012; 287:34992-35003. [PMID: 22923617 DOI: 10.1074/jbc.m112.389338] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
NAD(P)H cytochrome b(5) oxidoreductase (Ncb5or), comprising cytochrome b(5) and cytochrome b(5) reductase domains, is widely distributed in eukaryotic organisms. Although Ncb5or plays a crucial role in lipid metabolism of mice, so far no Ncb5or gene has been reported in the unicellular parasitic protozoa Leishmania species. We have cloned, expressed, and characterized Ncb5or gene from Leishmania major. Steady state catalysis and spectral studies show that NADH can quickly reduce the ferric state of the enzyme to the ferrous state and is able to donate an electron(s) to external acceptors. To elucidate its exact physiological role in Leishmania, we attempted to create NAD(P)H cytochrome b(5) oxidoreductase from L. major (LmNcb5or) knock-out mutants by targeted gene replacement technique. A free fatty acid profile in knock-out (KO) cells reveals marked deficiency in linoleate and linolenate when compared with wild type (WT) or overexpressing cells. KO culture has a higher percentage of dead cells compared with both WT and overexpressing cells. Increased O(2) uptake, uncoupling and ATP synthesis, and loss of mitochondrial membrane potential are evident in KO cells. Flow cytometric analysis reveals the presence of a higher concentration of intracellular H(2)O(2), indicative of increased oxidative stress in parasites lacking LmNcb5or. Cell death is significantly reduced when the KO cells are pretreated with BSA bound linoleate. Real time PCR studies demonstrate a higher Δ12 desaturase, superoxide dismutase, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA with a concomitant fall in Δ9 desaturase mRNA expression in LmNcb5or null cell line. Together these findings suggest that decreased linoleate synthesis, and increased oxidative stress and apoptosis are the major consequences of LmNcb5or deficiency in Leishmania.
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Affiliation(s)
- Supratim Mukherjee
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Sumit Sen Santara
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Shantanabha Das
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Moumita Bose
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Jayasree Roy
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Subrata Adak
- Division of Structural Biology and Bioinformatics, Council of Scientific and Industrial Research, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India.
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Yamazaki T, Okada H, Sakamoto T, Sunaga K, Tsuda T, Mitsumoto A, Kudo N, Kawashima Y. Differential induction of stearoyl-CoA desaturase 1 and 2 genes by fibrates in the liver of rats. Biol Pharm Bull 2012; 35:116-20. [PMID: 22223347 DOI: 10.1248/bpb.35.116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The administration of fibrates (fenofibrate, bezafibrate and clofibric acid) to rats induced stearoyl-CoA desaturase (SCD) in the liver, and increased relative expression of mRNAs encoding SCD1 and SCD2 in dose- and time-dependent manners. The magnitudes of the increases in SCD2 mRNA level caused by fenofibrate and clofibric acid were much higher than those of SCD1 at relatively higher doses of the fibrates, and a relatively long time (7 or 14 d) was required for significant induction of SCD2 mRNA expression compared with that of SCD1. Although the absolute number of transcripts for SCD2 was 1,800 times lower than that of SCD1 in the control liver, it was strikingly increased by fibrates. These results suggest that differential regulations operate for the gene expression between SCD1 and SCD2, and that the physiological significance of SCD2 is distinct from that of SCD1 in the liver.
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Affiliation(s)
- Tohru Yamazaki
- Faculty of Pharmaceutical Sciences, Josai University, 1–1 Keyakidai, Sakado, Saitama 350–0295, Japan
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27
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High fat feeding exacerbates endoplasmic reticulum stress and beta cell demise. EUR J LIPID SCI TECH 2012. [DOI: 10.1002/ejlt.201200058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Guo Y, Xu M, Deng B, Frontera JR, Kover KL, Aires D, Ding H, Carlson SE, Turk J, Wang W, Zhu H. Beta-Cell Injury in Ncb5or-null Mice is Exacerbated by Consumption of a High-Fat Diet. EUR J LIPID SCI TECH 2011; 114:233-243. [PMID: 22582025 DOI: 10.1002/ejlt.201100309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
NADH-cytochrome b5 oxidoreductase (Ncb5or) in endoplasmic reticulum (ER) is involved in fatty acid metabolism, and Ncb5or(-/-) mice fed standard chow (SC) are insulin-sensitive but weigh less than wild type (WT) littermates. Ncb5or(-/-) mice develop hyperglycemia at about age 7 weeks due to β-cell dysfunction and loss associated with saturated fatty acid accumulation and manifestations of ER and oxidative stress. Here we report that when Ncb5or(-/-) mice born to heterozygous mothers fed a high fat (HF) diet continue to ingest HF, they weigh as much as SC-fed WT at age 5 weeks. By age 7 weeks, diabetes mellitus develops in all HF-fed vs. 68% of SC-fed Ncb5or(-/-) mice. Islet β-cell content in age 5-week Ncb5or(-/-) mice fed HF for 7 days is lower (53%) than for those fed SC (63%), and both are lower than for WT (75%, SC, vs. 69%, HF). Islet transcript levels for markers of mitochondrial biogenesis (PGC-1α) and ER stress (ATF6α) are higher in Ncb5or(-/-) than WT mice but not significantly affected by diet. Consuming a HF diet exacerbates Ncb5or(-/-) β-cell accumulation of intracellular saturated fatty acids and increases the frequency of ER distention from 11% (SC) to 47% (HF), thus accelerates β-cell injury in Ncb5or(-/-) mice.
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Affiliation(s)
- Ying Guo
- Department of Endocrinology, The Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, China 510275
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29
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Mei S, Ni HM, Manley S, Bockus A, Kassel KM, Luyendyk JP, Copple BL, Ding WX. Differential roles of unsaturated and saturated fatty acids on autophagy and apoptosis in hepatocytes. J Pharmacol Exp Ther 2011; 339:487-98. [PMID: 21856859 DOI: 10.1124/jpet.111.184341] [Citation(s) in RCA: 230] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Fatty acid-induced lipotoxicity plays a critical role in the pathogenesis of nonalcoholic liver disease. Saturated fatty acids and unsaturated fatty acids have differential effects on cell death and steatosis, but the mechanisms responsible for these differences are not known. Using cultured HepG2 cells and primary mouse hepatocytes, we found that unsaturated and saturated fatty acids differentially regulate autophagy and apoptosis. The unsaturated fatty acid, oleic acid, promoted the formation of triglyceride-enriched lipid droplets and induced autophagy but had a minimal effect on apoptosis. In contrast, the saturated fatty acid, palmitic acid, was poorly converted into triglyceride-enriched lipid droplets, suppressed autophagy, and significantly induced apoptosis. Subsequent studies revealed that palmitic acid-induced apoptosis suppressed autophagy by inducing caspase-dependent Beclin 1 cleavage, indicating cross-talk between apoptosis and autophagy. Moreover, our data suggest that the formation of triglyceride-enriched lipid droplets and induction of autophagy are protective mechanisms against fatty acid-induced lipotoxicity. In line with our in vitro findings, we found that high-fat diet-induced hepatic steatosis was associated with autophagy in the mouse liver. Potential modulation of autophagy may be a novel approach that has therapeutic benefits for obesity-induced steatosis and liver injury.
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Affiliation(s)
- Shuang Mei
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center MS 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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30
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Wang W, Guo Y, Xu M, Huang HH, Novikova L, Larade K, Jiang ZG, Thayer TC, Frontera JR, Aires D, Ding H, Turk J, Mathews CE, Bunn HF, Stehno-Bittel L, Zhu H. Development of diabetes in lean Ncb5or-null mice is associated with manifestations of endoplasmic reticulum and oxidative stress in beta cells. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1532-41. [PMID: 21839170 DOI: 10.1016/j.bbadis.2011.07.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/15/2011] [Accepted: 07/26/2011] [Indexed: 01/01/2023]
Abstract
NADH-cytochrome b5 oxidoreductase (Ncb5or) is an endoplasmic reticulum (ER)-associated redox enzyme involved in fatty acid metabolism, and phenotypic abnormalities of Ncb5or(-/-) mice include diabetes and lipoatrophy. These mice are lean and insulin-sensitive but become hyperglycemic at age 7 weeks as a result of β-cell dysfunction and loss. Here we examine early cellular and molecular events associated with manifestations of β-cell defects in Ncb5or(-/-) mice. We observe lower islet β-cell content in pancreata at age 4 weeks and prominent ER distention in β-cells by age 5 weeks. Ultrastructural changes progress rapidly in severity from age 5 to 6 weeks, and their frequency rises from 10% of β-cells at 5 weeks to 33% at 6 weeks. These changes correlate temporally with the onset of diabetes. ER stress responses and lipid load in Ncb5or(-/-) β-cells were assessed with isolated islets from mice at age 5 weeks. Expression levels of the stress marker protein Grp78/BiP and of phosphorylated eIF2α protein were found to be reduced, although their transcript levels did not decline. This pattern stands in contrast to the canonical unfolded protein response. Ncb5or(-/-) β-cells also accumulated higher intracellular levels of palmitate and other free fatty acids and exhibited greater reactive oxygen species production than wild-type cells. An alloxan-susceptible genetic background was found to confer accelerated onset of diabetes in Ncb5or(-/-) mice. These findings provide the first direct evidence that manifestations of diabetes in lean Ncb5or(-/-) mice involve saturated free fatty acid overload of β-cells and ER and oxidative stress responses.
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Affiliation(s)
- Wenfang Wang
- Department of Physical Therapy and Rehabilitation Science, The University of Kansas Medical Center, Kansas City, KS 66160, USA
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