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Fernandes MF, Aristizabal-Henao JJ, Marvyn PM, M'Hiri I, Wiens MA, Hoang M, Sebastian M, Nachbar R, St-Pierre P, Diaguarachchige De Silva K, Wood GA, Joseph JW, Doucette CA, Marette A, Stark KD, Duncan RE. Renal tubule-specific Atgl deletion links kidney lipid metabolism to glucagon-like peptide 1 and insulin secretion independent of renal inflammation or lipotoxicity. Mol Metab 2024; 81:101887. [PMID: 38280449 PMCID: PMC10850971 DOI: 10.1016/j.molmet.2024.101887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 01/29/2024] Open
Abstract
OBJECTIVE Lipotoxic injury from renal lipid accumulation in obesity and type 2 diabetes (T2D) is implicated in associated kidney damage. However, models examining effects of renal ectopic lipid accumulation independent of obesity or T2D are lacking. We generated renal tubule-specific adipose triglyceride lipase knockout (RT-SAKO) mice to determine if this targeted triacylglycerol (TAG) over-storage affects glycemic control and kidney health. METHODS Male and female RT-SAKO mice and their control littermates were tested for changes in glycemic control at 10-12 and 16-18 weeks of age. Markers of kidney health and blood lipid and hormone concentrations were analyzed. Kidney and blood lysophosphatidic acid (LPA) levels were measured, and a role for LPA in mediating impaired glycemic control was evaluated using the LPA receptor 1/3 inhibitor Ki-16425. RESULTS All groups remained insulin sensitive, but 16- to 18-week-old male RT-SAKO mice became glucose intolerant, without developing kidney inflammation or fibrosis. Rather, these mice displayed lower circulating insulin and glucagon-like peptide 1 (GLP-1) levels. Impaired first-phase glucose-stimulated insulin secretion was detected and restored by Exendin-4. Kidney and blood LPA levels were elevated in older male but not female RT-SAKO mice, associated with increased kidney diacylglycerol kinase epsilon. Inhibition of LPA-mediated signaling restored serum GLP-1 levels, first-phase insulin secretion, and glucose tolerance. CONCLUSIONS TAG over-storage alone is insufficient to cause renal tubule lipotoxicity. This work is the first to show that endogenously derived LPA modulates GLP-1 levels in vivo, demonstrating a new mechanism of kidney-gut-pancreas crosstalk to regulate insulin secretion and glucose homeostasis.
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Affiliation(s)
- Maria F Fernandes
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | | | - Phillip M Marvyn
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Iman M'Hiri
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Meghan A Wiens
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | - Manuel Sebastian
- Max Rady College of Medicine, University of Manitoba, Manitoba, Canada
| | - Renato Nachbar
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Philippe St-Pierre
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | | | - Geoffrey A Wood
- Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | | | - André Marette
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Ken D Stark
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Robin E Duncan
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada.
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2
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Tang H, Lv F, Zhang P, Liu J, Mao J. The impact of obstructive sleep apnea on nonalcoholic fatty liver disease. Front Endocrinol (Lausanne) 2023; 14:1254459. [PMID: 37850091 PMCID: PMC10577417 DOI: 10.3389/fendo.2023.1254459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/15/2023] [Indexed: 10/19/2023] Open
Abstract
Obstructive sleep apnea (OSA) is characterized by episodic sleep state-dependent collapse of the upper airway, with consequent hypoxia, hypercapnia, and arousal from sleep. OSA contributes to multisystem damage; in severe cases, sudden cardiac death might occur. In addition to causing respiratory, cardiovascular and endocrine metabolic diseases, OSA is also closely associated with nonalcoholic fatty liver disease (NAFLD). As the prevalence of OSA and NAFLD increases rapidly, they significantly exert adverse effects on the health of human beings. The authors retrieved relevant documents on OSA and NAFLD from PubMed and Medline. This narrative review elaborates on the current knowledge of OSA and NAFLD, demonstrates the impact of OSA on NAFLD, and clarifies the underlying mechanisms of OSA in the progression of NAFLD. Although there is a lack of sufficient high-quality clinical studies to prove the causal or concomitant relationship between OSA and NAFLD, existing evidence has confirmed the effect of OSA on NAFLD. Elucidating the underlying mechanisms through which OSA impacts NAFLD would hold considerable importance in terms of both prevention and the identification of potential therapeutic targets for NAFLD.
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Affiliation(s)
- Haiying Tang
- Department of Respiratory and Critical Disease, Respiratory Sleep Disorder Center, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Furong Lv
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Peng Zhang
- Department of Medical Information Engineering, Zhongshan College of Dalian Medical University, Dalian, Liaoning, China
| | - Jia Liu
- Department of Respiratory and Critical Disease, Respiratory Sleep Disorder Center, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Jingwei Mao
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
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3
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Ge Y, Bruno M, Nash MS, Coates NH, Chorley BN, Cave MC, Beier JI. Vinyl chloride enhances high-fat diet-induced proteome alterations in the mouse pancreas related to metabolic dysfunction. Toxicol Sci 2023; 193:103-114. [PMID: 36892438 PMCID: PMC10176240 DOI: 10.1093/toxsci/kfad024] [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] [Indexed: 03/10/2023] Open
Abstract
Alterations in physiological processes in pancreas have been associated with various metabolic dysfunctions and can result from environmental exposures, such as chemicals and diet. It was reported that environmental vinyl chloride (VC) exposure, a common industrial organochlorine and environmental pollutant, significantly exacerbated metabolic-related phenotypes in mice fed concurrently with high-fat diet (HFD) but not low-fat diet (LFD). However, little is known about the role of the pancreas in this interplay, especially at a proteomic level. The present study was undertaken to examine the protein responses to VC exposure in pancreas tissues of C57BL/6J mice fed LFD or HFD, with focus on the investigation of protein expression and/or phosphorylation levels of key protein biomarkers of carbohydrate, lipid, and energy metabolism, oxidative stress and detoxification, insulin secretion and regulation, cell growth, development, and communication, immunological responses and inflammation, and biomarkers of pancreatic diseases and cancers. We found that the protein alterations may indicate diet-mediated susceptibility in mouse pancreas induced by HFD to concurrent exposure of low levels of inhaled VC. These proteome biomarkers may lead to a better understanding of pancreas-mediated adaptive or adverse response and susceptibility to metabolic disease.
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Affiliation(s)
- Yue Ge
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Maribel Bruno
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Maliha S Nash
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Najwa Haykal Coates
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Brian N Chorley
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
| | - Matthew C Cave
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky 40202, USA
| | - Juliane I Beier
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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4
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Wang J, Lu P, Xie W. Atypical functions of xenobiotic receptors in lipid and glucose metabolism. MEDICAL REVIEW (2021) 2022; 2:611-624. [PMID: 36785576 PMCID: PMC9912049 DOI: 10.1515/mr-2022-0032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/08/2022] [Indexed: 12/02/2022]
Abstract
Xenobiotic receptors are traditionally defined as xenobiotic chemical-sensing receptors, the activation of which transcriptionally regulates the expression of enzymes and transporters involved in the metabolism and disposition of xenobiotics. Emerging evidence suggests that "xenobiotic receptors" also have diverse endobiotic functions, including their effects on lipid metabolism and energy metabolism. Dyslipidemia is a major risk factor for cardiovascular disease, diabetes, obesity, metabolic syndrome, stroke, nonalcoholic fatty liver disease (NAFLD), and nonalcoholic steatohepatitis (NASH). Understanding the molecular mechanism by which transcriptional factors, including the xenobiotic receptors, regulate lipid homeostasis will help to develop preventive and therapeutic approaches. This review describes recent advances in our understanding the atypical roles of three xenobiotic receptors: aryl hydrocarbon receptor (AhR), pregnane X receptor (PXR), and constitutive androstane receptor (CAR), in metabolic disorders, with a particular focus on their effects on lipid and glucose metabolism. Collectively, the literatures suggest the potential values of AhR, PXR and CAR as therapeutic targets for the treatment of NAFLD, NASH, obesity and diabetes, and cardiovascular diseases.
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Affiliation(s)
- Jingyuan Wang
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peipei Lu
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
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5
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Xiang J, Deng YY, Liu HX, Pu Y. LncRNA MALAT1 Promotes PPARα/CD36-Mediated Hepatic Lipogenesis in Nonalcoholic Fatty Liver Disease by Modulating miR-206/ARNT Axis. Front Bioeng Biotechnol 2022; 10:858558. [PMID: 35769097 PMCID: PMC9234139 DOI: 10.3389/fbioe.2022.858558] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/16/2022] [Indexed: 01/21/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) are known to play crucial roles in nonalcoholic fatty liver disease (NAFLD). This research sought to explore mechanisms by which lncRNA MALAT1 regulates the progression of NAFLD. Thus, in order to detect the function of MALAT1 in NAFLD, in vitro and in vivo model of NAFLD were established. Then, fatty acid uptake and triglyceride level were investigated by BODIPY labeled-fatty acid uptake assay and Oil red O staining, respectively. The expressions of MALAT1, miR-206, ARNT, PPARα and CD36 were detected by western blotting and qPCR. Dual luciferase, RIP and ChIP assay were used to validate the relation among MALAT1, miR-206, ARNT and PPARα. The data revealed expression of MALAT1 was up-regulated in vitro and in vivo in NAFLD, and knockdown of MALAT1 suppressed FFA-induced lipid accumulation in hepatocytes. Meanwhile, MALAT1 upregulated the expression of ARNT through binding with miR-206. Moreover, miR-206 inhibitor reversed MALAT1 knockdown effects in decreased lipid accumulation in FFA-treated hepatocytes. Furthermore, ARNT could inhibit the expression of PPARα via binding with PPARα promoter. Knockdown of MALAT1 significantly upregulated the level of PPARα and downregulated the expression of CD36, while PPARα knockdown reversed these phenomena. MALAT1 regulated PPARα/CD36 -mediated hepatic lipid accumulation in NAFLD through regulation of miR-206/ARNT axis. Thus, MALAT1/miR-206/ARNT might serve as a therapeutic target against NAFLD.
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Affiliation(s)
- Juan Xiang
- Endocrinology Subspecialty of Geriatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Yuan-Yuan Deng
- Endocrinology Subspecialty of Geriatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Hui-Xia Liu
- Endocrinology Subspecialty of Geriatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Ying Pu
- Endocrinology Subspecialty of Geriatrics, Xiangya Hospital of Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Ying Pu,
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6
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Ilegems E, Bryzgalova G, Correia J, Yesildag B, Berra E, Ruas JL, Pereira TS, Berggren PO. HIF-1α inhibitor PX-478 preserves pancreatic β cell function in diabetes. Sci Transl Med 2022; 14:eaba9112. [PMID: 35353540 DOI: 10.1126/scitranslmed.aba9112] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During progression of type 2 diabetes, pancreatic β cells are subjected to sustained metabolic overload. We postulated that this state mediates a hypoxic phenotype driven by hypoxia-inducible factor-1α (HIF-1α) and that treatment with the HIF-1α inhibitor PX-478 would improve β cell function. Our studies showed that the HIF-1α protein was present in pancreatic β cells of diabetic mouse models. In mouse islets with high glucose metabolism, the emergence of intracellular Ca2+ oscillations at low glucose concentration and the abnormally high basal release of insulin were suppressed by treatment with the HIF-1α inhibitor PX-478, indicating improvement of β cell function. Treatment of db/db mice with PX-478 prevented the rise of glycemia and diabetes progression by maintenance of elevated plasma insulin concentration. In streptozotocin-induced diabetic mice, PX-478 improved the recovery of glucose homeostasis. Islets isolated from these mice showed hallmarks of improved β cell function including elevation of insulin content, increased expression of genes involved in β cell function and maturity, inhibition of dedifferentiation markers, and formation of mature insulin granules. In response to PX-478 treatment, human islet organoids chronically exposed to high glucose presented improved stimulation index of glucose-induced insulin secretion. These results suggest that the HIF-1α inhibitor PX-478 has the potential to act as an antidiabetic therapeutic agent that preserves β cell function under metabolic overload.
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Affiliation(s)
- Erwin Ilegems
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Galyna Bryzgalova
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Jorge Correia
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | | | - Edurne Berra
- Centro de Investigación Cooperativa en Biociencias CIC bioGUNE, 48160 Derio, Spain
| | - Jorge L Ruas
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Teresa S Pereira
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.,Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.,Lee Kong Chian School of Medicine, Nanyang Technological University, Novena Campus, 308232 Singapore, Singapore.,School of Biomedical Sciences, Ulster University, BT52 1SA Coleraine, Northern Ireland, UK
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7
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Hoang M, Jentz E, Janssen SM, Nasteska D, Cuozzo F, Hodson DJ, Tupling AR, Fong GH, Joseph JW. Isoform-specific Roles of Prolyl Hydroxylases in the Regulation of Pancreatic β-Cell Function. Endocrinology 2022; 163:6413706. [PMID: 34718519 PMCID: PMC8643417 DOI: 10.1210/endocr/bqab226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Indexed: 11/19/2022]
Abstract
Pancreatic β-cells can secrete insulin via 2 pathways characterized as KATP channel -dependent and -independent. The KATP channel-independent pathway is characterized by a rise in several potential metabolic signaling molecules, including the NADPH/NADP+ ratio and α-ketoglutarate (αKG). Prolyl hydroxylases (PHDs), which belong to the αKG-dependent dioxygenase superfamily, are known to regulate the stability of hypoxia-inducible factor α. In the current study, we assess the role of PHDs in vivo using the pharmacological inhibitor dimethyloxalylglycine (DMOG) and generated β-cell-specific knockout (KO) mice for all 3 isoforms of PHD (β-PHD1 KO, β-PHD2 KO, and β-PHD3 KO mice). DMOG inhibited in vivo insulin secretion in response to glucose challenge and inhibited the first phase of insulin secretion but enhanced the second phase of insulin secretion in isolated islets. None of the β-PHD KO mice showed any significant in vivo defects associated with glucose tolerance and insulin resistance except for β-PHD2 KO mice which had significantly increased plasma insulin during a glucose challenge. Islets from both β-PHD1 KO and β-PHD3 KO had elevated β-cell apoptosis and reduced β-cell mass. Isolated islets from β-PHD1 KO and β-PHD3 KO had impaired glucose-stimulated insulin secretion and glucose-stimulated increases in the ATP/ADP and NADPH/NADP+ ratio. All 3 PHD isoforms are expressed in β-cells, with PHD3 showing the most distinct expression pattern. The lack of each PHD protein did not significantly impair in vivo glucose homeostasis. However, β-PHD1 KO and β-PHD3 KO mice had defective β-cell mass and islet insulin secretion, suggesting that these mice may be predisposed to developing diabetes.
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Affiliation(s)
- Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Emelien Jentz
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Sarah M Janssen
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - A Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Guo-Hua Fong
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
- Correspondence: Jamie W. Joseph, PhD, Health Science Campus Building A, Room 4008, University of Waterloo, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5.
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8
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Abstract
Hypoxia-inducible factors (HIFs) are the key regulators of oxygen homeostasis in response to hypoxia. In diabetes, multiple tissues are hypoxic but adaptive responses to hypoxia are impaired due to insufficient activation of HIF signalling, which results from inhibition of HIF-1α stability and function due to hyperglycaemia and elevated fatty acid levels. In this review, we will summarise and discuss current findings about the regulation of HIF signalling in diabetes and the pathogenic roles of hypoxia and dysregulated HIF signalling in the development of diabetes and its complications. The therapeutic potential of targeting HIF signalling for the prevention and treatment of diabetes and related complications is also discussed.
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Affiliation(s)
- Sergiu-Bogdan Catrina
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
- Department of Endocrinology and Diabetes, Karolinska University Hospital, Stockholm, Sweden.
- Center for Diabetes, Academic Specialist Centrum, Stockholm, Sweden.
| | - Xiaowei Zheng
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
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9
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Yang W, Chi Y, Meng Y, Chen Z, Xiang R, Yan H, Yang J. FAM3A plays crucial roles in controlling PDX1 and insulin expressions in pancreatic beta cells. FASEB J 2020; 34:3915-3931. [PMID: 31944392 DOI: 10.1096/fj.201902368rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 11/11/2022]
Abstract
So far, the mechanism that links mitochondrial dysfunction to PDX1 inhibition in the pathogenesis of pancreatic β cell dysfunction under diabetic condition remains largely unclear. This study determined the role of mitochondrial protein FAM3A in regulating PDX1 expression in pancreatic β cells using gain- and loss-of function methods in vitro and in vivo. Within pancreas, FAM3A is highly expressed in β, α, δ, and pp cells of islets. Islet FAM3A expression was correlated with insulin expression under physiological and diabetic conditions. Mice with specific knockout of FAM3A in islet β cells exhibited markedly blunted insulin secretion and glucose intolerance. FAM3A-deficient islets showed significant decrease in PDX1 expression, and insulin expression and secretion. FAM3A overexpression upregulated PDX1 and insulin expressions, and augmented insulin secretion in cultured islets and β cells. Mechanistically, FAM3A enhanced ATP production to elevate cellular Ca2+ level and promote insulin secretion. Furthermore, FAM3A-induced ATP release activated CaM to function as a co-activator of FOXA2, stimulating PDX1 gene transcription. In conclusion, FAM3A plays crucial roles in controlling PDX1 and insulin expressions in pancreatic β cells. Inhibition of FAM3A will trigger mitochondrial dysfunction to repress PDX1 and insulin expressions.
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Affiliation(s)
- Weili Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China.,Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yujing Chi
- Department of Central Laboratory & Institute of Clinical Molecular Biology, Peking University People's Hospital, Beijing, China
| | - Yuhong Meng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Zhenzhen Chen
- State Key Laboratory of Cardiovascular Disease, Hypertension Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rui Xiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Han Yan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Jichun Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
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