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Aoyagi K, Nishiwaki C, Nakamichi Y, Yamashita SI, Kanki T, Ohara-Imaizumi M. Imeglimin mitigates the accumulation of dysfunctional mitochondria to restore insulin secretion and suppress apoptosis of pancreatic β-cells from db/db mice. Sci Rep 2024; 14:6178. [PMID: 38485716 PMCID: PMC10940628 DOI: 10.1038/s41598-024-56769-w] [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] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/11/2024] [Indexed: 03/18/2024] Open
Abstract
Mitochondrial dysfunction in pancreatic β-cells leads to impaired glucose-stimulated insulin secretion (GSIS) and type 2 diabetes (T2D), highlighting the importance of autophagic elimination of dysfunctional mitochondria (mitophagy) in mitochondrial quality control (mQC). Imeglimin, a new oral anti-diabetic drug that improves hyperglycemia and GSIS, may enhance mitochondrial activity. However, chronic imeglimin treatment's effects on mQC in diabetic β-cells are unknown. Here, we compared imeglimin, structurally similar anti-diabetic drug metformin, and insulin for their effects on clearance of dysfunctional mitochondria through mitophagy in pancreatic β-cells from diabetic model db/db mice and mitophagy reporter (CMMR) mice. Pancreatic islets from db/db mice showed aberrant accumulation of dysfunctional mitochondria and excessive production of reactive oxygen species (ROS) along with markedly elevated mitophagy, suggesting that the generation of dysfunctional mitochondria overwhelmed the mitophagic capacity in db/db β-cells. Treatment with imeglimin or insulin, but not metformin, reduced ROS production and the numbers of dysfunctional mitochondria, and normalized mitophagic activity in db/db β-cells. Concomitantly, imeglimin and insulin, but not metformin, restored the secreted insulin level and reduced β-cell apoptosis in db/db mice. In conclusion, imeglimin mitigated accumulation of dysfunctional mitochondria through mitophagy in diabetic mice, and may contribute to preserving β-cell function and effective glycemic control in T2D.
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Affiliation(s)
- Kyota Aoyagi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611, Japan
| | - Chiyono Nishiwaki
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611, Japan
| | - Yoko Nakamichi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611, Japan
| | - Shun-Ichi Yamashita
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8510, Japan
| | - Tomotake Kanki
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8510, Japan
| | - Mica Ohara-Imaizumi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo, 181-8611, Japan.
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2
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Wang LH, Wang YY, Liu L, Gong Q. From Diabetes to Diabetic Complications: Role of Autophagy. Curr Med Sci 2023:10.1007/s11596-023-2727-4. [PMID: 37115396 DOI: 10.1007/s11596-023-2727-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 12/29/2022] [Indexed: 04/29/2023]
Abstract
Diabetes and its complications reduce quality of life and are life-limiting. At present, diabetes treatment consists of hypoglycemic agents to control blood glucose and the use of insulin-sensitizing drugs to overcome insulin resistance. In diabetes, autophagy is impaired and thus there is poor intracellular environment homeostasis. Pancreatic β-cells and insulin target tissues are protected by enhancing autophagy. Autophagy decreases β-cell apoptosis, promotes β-cell proliferation, and alleviates insulin resistance. Autophagy in diabetes is regulated by the mammalian target of rapamycin (mTOR)/adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway and others. Autophagy enhancers can likely be used as a treatment for diabetes and its complications. This review examines the evidence linking autophagy to diabetes.
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Affiliation(s)
- Lin-Hua Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China
| | - Yang-Yang Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China
| | - Lian Liu
- Department of Pharmacology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, 434023, China.
| | - Quan Gong
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China.
- Department of Immunology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, 434023, China.
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3
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Aoyagi K, Yamashita SI, Akimoto Y, Nishiwaki C, Nakamichi Y, Udagawa H, Abe M, Sakimura K, Kanki T, Ohara-Imaizumi M. A new beta cell-specific mitophagy reporter mouse shows that metabolic stress leads to accumulation of dysfunctional mitochondria despite increased mitophagy. Diabetologia 2023; 66:147-162. [PMID: 36181536 DOI: 10.1007/s00125-022-05800-8] [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: 01/15/2022] [Accepted: 08/11/2022] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Mitophagy, the selective autophagy of mitochondria, is essential for maintenance of mitochondrial function. Recent studies suggested that defective mitophagy in beta cells caused diabetes. However, because of technical difficulties, the development of a convenient and reliable method to evaluate mitophagy in beta cells in vivo is needed. The aim of this study was to establish beta cell-specific mitophagy reporter mice and elucidate the role of mitophagy in beta cell function under metabolically stressed conditions induced by a high-fat diet (HFD). METHODS Mitophagy was assessed using newly generated conditional mitochondrial matrix targeting mitophagy reporter (CMMR) mice, in which mitophagy can be visualised specifically in beta cells in vivo using a fluorescent probe sensitive to lysosomal pH and degradation. Metabolic stress was induced in mice by exposure to the HFD for 20 weeks. The accumulation of dysfunctional mitochondria was examined by staining for functional/total mitochondria and reactive oxygen species (ROS) using specific fluorescent dyes and antibodies. To investigate the molecular mechanism underlying mitophagy in beta cells, overexpression and knockdown experiments were performed. HFD-fed mice were examined to determine whether chronic insulin treatment for 6 weeks could ameliorate mitophagy, mitochondrial function and impaired insulin secretion. RESULTS Exposure to the HFD increased the number of enlarged (HFD-G) islets with markedly elevated mitophagy. Mechanistically, HFD feeding induced severe hypoxia in HFD-G islets, which upregulated mitophagy through the hypoxia-inducible factor 1-ɑ (Hif-1ɑ)/BCL2 interacting protein 3 (BNIP3) axis in beta cells. However, HFD-G islets unexpectedly showed the accumulation of dysfunctional mitochondria due to excessive ROS production, suggesting an insufficient capacity of mitophagy for the degradation of dysfunctional mitochondria. Chronic administration of insulin ameliorated hypoxia and reduced ROS production and dysfunctional mitochondria, leading to decreased mitophagy and restored insulin secretion. CONCLUSIONS/INTERPRETATION We demonstrated that CMMR mice enabled the evaluation of mitophagy in beta cells. Our results suggested that metabolic stress induced by the HFD caused the aberrant accumulation of dysfunctional mitochondria, which overwhelmed the mitophagic capacity and was associated with defective maintenance of mitochondrial function and impaired insulin secretion.
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Affiliation(s)
- Kyota Aoyagi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Shun-Ichi Yamashita
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yoshihiro Akimoto
- Department of Microscopic Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Chiyono Nishiwaki
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Yoko Nakamichi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Haruhide Udagawa
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tomotake Kanki
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Mica Ohara-Imaizumi
- Department of Cellular Biochemistry, Kyorin University School of Medicine, Tokyo, Japan.
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4
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Wang Y, Miao Y, Shen Q, Liu X, Chen M, Du J, Ning M, Bi J, Gu W, Wang L, Meng Q. Eriocheir sinensis vesicle-associated membrane protein can enhance host cell phagocytosis to resist Spiroplasma eriocheiris infection. FISH & SHELLFISH IMMUNOLOGY 2022; 128:582-591. [PMID: 35964876 DOI: 10.1016/j.fsi.2022.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/30/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Vesicle-associated membrane protein (VAMP) belongs to the receptor protein on the membrane of the secretory transport vesicle and involves in host immune function. The intracellular pathogen Spiroplasma eriocheiris could cause Eriocheir sinensis tremor disease. In a previous study, it was found E. sinensis VAMP (EsVAMP) was differently expressed in S. eriocheiris infection by proteomics analysis. This study mainly aims at the function of EsVAMP in the process of the S. eriocheiris infection. The length of EsVAMP gene was 1681 bp, which contained a 395 bp open reading frame, 90 bp 5'-non-coding region (UTR) and 1277 bp 3'-UTR. The results of qPCR showed that EsVAMP was expressed highly in hemocytes and nerves, followed by gills, intestines and hepatopancreas, and lowly expressed in heart and muscles. EsVAMP in hemocytes was up-regulated after S. eriocheiris infection. After EsVAMP over-expression and S. eriocheiris infection, the RAW264.7 cell morphology and cell viability of the experiment group were significantly better than the control group. Meanwhile, the copy number of S. eriocheiris in the experiment group was significantly lower than that in the control group. After EsVAMP and pCMV-Cre-mCherry were ligated and transfected into RAW264.7 cells, it was found that EsVAMP and lysosome co-localized. Meanwhile, the phagocytosed inactivated S. eriocheiris number and phagocytosed efficiency in RAW264.7 cells were increased significantly. The interference experiment was carried out by synthesizing EsVAMP dsRNA to verify that the EsVAMP transcriptions were successfully suppressed. The S. eriocheiris copy number and the mortality of crab increased significantly after EsVAMP RNAi and S. eriocheiris infection. Meanwhile, the phagocytosed inactivated S. eriocheiris number and phagocytosed efficiency in hemocytes decreased significantly after EsVAMP RNAi and S. eriocheiris infection. These results showed that VAMP was involved in the cell phagocytosis to resist pathogen infection.
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Affiliation(s)
- Yaqin Wang
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Yanyang Miao
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Qingchun Shen
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Xueshi Liu
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Minyi Chen
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Jie Du
- Animal Husbandry and Veterinary College, Jiangsu Vocational College of Agriculture and Forestry, Jurong, Jiangsu, 212400, China
| | - Mingxiao Ning
- Institution of Quality Standard and Testing Technology for Agro-product, Shandong Academy of Agricultural Science, Jinan, Shandong, 250100, China
| | - Jingxiu Bi
- Institution of Quality Standard and Testing Technology for Agro-product, Shandong Academy of Agricultural Science, Jinan, Shandong, 250100, China
| | - Wei Gu
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China
| | - Li Wang
- College of Animal & Veterinary Sciences, Southwest Minzu University, Chengdu, 610041, China.
| | - Qingguo Meng
- Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Marine Science and Engineering, Nanjing Normal University, 2 Xuelin Road, Nanjing, 210023, China.
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5
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The Emerging Roles of Autophagy in Human Diseases. Biomedicines 2021; 9:biomedicines9111651. [PMID: 34829881 PMCID: PMC8615641 DOI: 10.3390/biomedicines9111651] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 01/18/2023] Open
Abstract
Autophagy, a process of cellular self-digestion, delivers intracellular components including superfluous and dysfunctional proteins and organelles to the lysosome for degradation and recycling and is important to maintain cellular homeostasis. In recent decades, autophagy has been found to help fight against a variety of human diseases, but, at the same time, autophagy can also promote the procession of certain pathologies, which makes the connection between autophagy and diseases complex but interesting. In this review, we summarize the advances in understanding the roles of autophagy in human diseases and the therapeutic methods targeting autophagy and discuss some of the remaining questions in this field, focusing on cancer, neurodegenerative diseases, infectious diseases and metabolic disorders.
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6
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Tian X, Teng J, Chen J. New insights regarding SNARE proteins in autophagosome-lysosome fusion. Autophagy 2021; 17:2680-2688. [PMID: 32924745 PMCID: PMC8525925 DOI: 10.1080/15548627.2020.1823124] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/04/2020] [Accepted: 09/09/2020] [Indexed: 12/26/2022] Open
Abstract
Macroautophagy/autophagy refers to the engulfment of cellular contents selected for lysosomal degradation. The final step in autophagy is the fusion of autophagosome with the lysosome, which is mediated by SNARE proteins. Of the SNAREs, autophagosome-localized Q-SNAREs, such as STX17 and SNAP29, and lysosome-localized R-SNAREs, such as VAMP8 or VAMP7, have been reported to be involved. Recent studies also reveal participation of the R-SNARE, YKT6, in autophagosome-lysosome fusion. These SNAREs, with the help of other regulatory factors, act coordinately to spatiotemporally control the fusion process. Besides regulating autophagosome-lysosome fusion, some SNAREs, such as STX17, also function in other autophagic processes, including autophagosome formation and mitophagy. A better understanding of the functions of SNAREs will shed light on the molecular mechanisms of autophagosome-lysosome fusion as well as on the mechanisms by which autophagy is globally regulated.Abbreviations: ATG: autophagy related; DNM1L: dynamin 1 like; ER: endoplasmic reticulum; GABARAP: GABA type A receptor-associated protein; GABARAPL1: GABA type A receptor associated protein like 1; IRGM: immunity related GTPase M; LAMP2: lysosomal associated membrane protein 2; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; PIK3R4: phosphoinositide-3-kinase regulatory subunit 4; PLEKHM1: pleckstrin homology and RUN domain containing M1; PRKN: PRKN RBR E3 ubiquitin protein ligase; RAB2A: RAB2A, member RAS oncogene family; RAB33B: RAB33B, member RAS oncogene family; RAB7A: RAB7A, member RAS oncogene family; RB1CC1: RB1 inducible coiled-coil 1; RTN3: reticulon 3; RUBCNL: rubicon like autophagy enhancer; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SNAP29: synaptosomal associated protein 29; STX17: syntaxin 17; ULK1: unc-51 like autophagy activating kinase 1; VAMP7: vesicle associated membrane protein 7; VAMP8: vesicle associated membrane protein 8; YKT6: YKT6 v-SNARE homolog.
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Affiliation(s)
- Xiaoyu Tian
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, China
| | - Junlin Teng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, China
| | - Jianguo Chen
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, China
- Center for Quantitative Biology, Peking University, Beijing, China
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7
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Gu J, Geng M, Qi M, Wang L, Zhang Y, Gao J. The role of lysosomal membrane proteins in glucose and lipid metabolism. FASEB J 2021; 35:e21848. [PMID: 34582051 DOI: 10.1096/fj.202002602r] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/11/2021] [Accepted: 07/26/2021] [Indexed: 11/11/2022]
Abstract
Lysosomes have long been regarded as the "garbage dump" of the cell. More recently, however, researchers have revealed novel roles for lysosomal membranes in autophagy, ion transport, nutrition sensing, and membrane fusion and repair. With active research into lysosomal membrane proteins (LMP), increasing evidence has become available showing that LMPs are inextricably linked to glucose and lipid metabolism, and this relationship represents mutual influence and regulation. In this review, we summarize the roles of LMPs in relation to glucose and lipid metabolism, and describe their roles in glucose transport, glycolysis, cholesterol transport, and lipophagy. The role of transport proteins can be traced back to the original discoveries of GLUT8, NPC1, and NPC2, which were all found to have significant roles in the pathways involved in glucose and lipid metabolism. CLC-5 and SIDT2-knockout animals show serious phenotypic disorders of metabolism, and V-ATPase and LAMP-2 have been found to interact with proteins related to glucose and lipid metabolism. These findings all emphasize the critical role of LMPs in glycolipid metabolism and help to strengthen our understanding of the independent and close relationship between LMPs and glycolipid metabolism.
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Affiliation(s)
- Jing Gu
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
| | - Mengya Geng
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Mengxiang Qi
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Lizhuo Wang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Yao Zhang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Jialin Gao
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
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8
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Sun-Wang JL, Yarritu-Gallego A, Ivanova S, Zorzano A. The ubiquitin-proteasome system and autophagy: self-digestion for metabolic health. Trends Endocrinol Metab 2021; 32:594-608. [PMID: 34034951 DOI: 10.1016/j.tem.2021.04.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 01/02/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is a global health challenge. Therefore, understanding the molecular mechanisms underlying the pathophysiology of T2DM is key to improving current therapies. Loss of protein homeostasis leads to the accumulation of damaged proteins in cells, which results in tissue dysfunction. The elimination of damaged proteins occurs through the ubiquitin-proteasome system (UPS) and autophagy. In this review, we describe the mutual regulation between the UPS and autophagy and the involvement of these two proteolytic systems in metabolic dysregulation, insulin resistance, and T2DM. We propose that alterations in the UPS or autophagy contribute to triggering insulin resistance and the development of T2DM. In addition, these two pathways emerge as promising therapeutic targets for improving insulin resistance.
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Affiliation(s)
- Jia Liang Sun-Wang
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, Spain.
| | - Alex Yarritu-Gallego
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Berlin, Germany; Experimental and Clinical Research Center, a Cooperation of Charité-Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine, Berlin, Germany
| | - Saška Ivanova
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, Spain
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, Spain.
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9
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Sandovici I, Hammerle CM, Virtue S, Vivas-Garcia Y, Izquierdo-Lahuerta A, Ozanne SE, Vidal-Puig A, Medina-Gómez G, Constância M. Autocrine IGF2 programmes β-cell plasticity under conditions of increased metabolic demand. Sci Rep 2021; 11:7717. [PMID: 33833312 PMCID: PMC8032793 DOI: 10.1038/s41598-021-87292-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/08/2021] [Indexed: 02/07/2023] Open
Abstract
When exposed to nutrient excess and insulin resistance, pancreatic β-cells undergo adaptive changes in order to maintain glucose homeostasis. The role that growth control genes, highly expressed in early pancreas development, might exert in programming β-cell plasticity in later life is a poorly studied area. The imprinted Igf2 (insulin-like growth factor 2) gene is highly transcribed during early life and has been identified in recent genome-wide association studies as a type 2 diabetes susceptibility gene in humans. Hence, here we investigate the long-term phenotypic metabolic consequences of conditional Igf2 deletion in pancreatic β-cells (Igf2βKO) in mice. We show that autocrine actions of IGF2 are not critical for β-cell development, or for the early post-natal wave of β-cell remodelling. Additionally, adult Igf2βKO mice maintain glucose homeostasis when fed a chow diet. However, pregnant Igf2βKO females become hyperglycemic and hyperinsulinemic, and their conceptuses exhibit hyperinsulinemia and placentomegalia. Insulin resistance induced by congenital leptin deficiency also renders Igf2βKO females more hyperglycaemic compared to leptin-deficient controls. Upon high-fat diet feeding, Igf2βKO females are less susceptible to develop insulin resistance. Based on these findings, we conclude that in female mice, autocrine actions of β-cell IGF2 during early development determine their adaptive capacity in adult life.
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Affiliation(s)
- Ionel Sandovici
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
- Department of Obstetrics and Gynaecology and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, CB2 0SW, UK.
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK.
| | - Constanze M Hammerle
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
- Department of Obstetrics and Gynaecology and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, CB2 0SW, UK.
- Novo Nordisk A/S, 2880, Bagsværd, Denmark.
| | - Sam Virtue
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Yurena Vivas-Garcia
- Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, 28922, Alcorcón, Madrid, Spain
- Nuffield Department of Clinical Medicine, Ludwig Institute for Cancer Research, University of Oxford, Headington, Oxford, OX3 7DQ, UK
| | - Adriana Izquierdo-Lahuerta
- Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, 28922, Alcorcón, Madrid, Spain
| | - Susan E Ozanne
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
- Welcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
- Cambridge University Nanjing Centre of Technology and Innovation, Jiangbei Area, Nanjing, People's Republic of China
| | - Gema Medina-Gómez
- Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, 28922, Alcorcón, Madrid, Spain
| | - Miguel Constância
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.
- Department of Obstetrics and Gynaecology and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, CB2 0SW, UK.
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK.
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10
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Behl T, Sehgal A, Bala R, Chadha S. Understanding the molecular mechanisms and role of autophagy in obesity. Mol Biol Rep 2021; 48:2881-2895. [PMID: 33797660 DOI: 10.1007/s11033-021-06298-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Vital for growth, proliferation, subsistence, and thermogenesis, autophagy is the biological cascade, which confers defence against aging and various pathologies. Current research has demonstrated de novo activity of autophagy in stimulation of biological events. There exists a significant association between autophagy activation and obesity, encompassing expansion of adipocytes which facilitates β cell activity. The main objective of the manuscript is to enumerate intrinsic role of autophagy in obesity and associated complications. The peer review articles published till date were searched using medical databases like PubMed and MEDLINE for research, primarily in English language. Obesity is characterized by adipocytic hypertrophy and hyperplasia, which leads to imbalance of lipid absorption, free fatty acid release, and mitochondrial activity. Detailed evaluation of obesity progression is necessary for its treatment and related comorbidities. Data collected in regard to etiological sustaining of obesity, has revealed hypothesized energy misbalance and neuro-humoral dysfunction, which is stimulated by autophagy. Autophagy regulates chief salvaging events for protein clustering, excessive triglycerides, and impaired mitochondria which is accompanied by oxidative and genotoxic stress in mammals. Autophagy is a homeostatic event, which regulates biological process by eliminating lethal cells and reprocessing physiological constituents, comprising of proteins and fat. Unquestionably, autophagy impairment is involved in metabolic syndromes, like obesity. According to an individual's metabolic outline, autophagy activation is essential for metabolism and activity of the adipose tissue and to retard metabolic syndrome i.e. obesity. The manuscript summarizes the perception of current knowledge on autophagy stimulation and its effect on the obesity.
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Affiliation(s)
- Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab, India.
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Rajni Bala
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Swati Chadha
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
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11
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Xu T, Yuan Y, He C, Yang K. Construction and Evaluation of a Risk Score Model for Autophagy-Related Genes in Esophageal Adenocarcinoma. Med Sci Monit 2021; 27:e927850. [PMID: 33510126 PMCID: PMC7852040 DOI: 10.12659/msm.927850] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Several studies have suggested the importance of autophagy during esophageal adenocarcinoma (EAC) development. This study aimed to explore the autophagy-related genes correlated with overall survival in patients with EAC. Material/Methods The RNA-seq expression profiles and clinical data of patients with EAC were screened using The Cancer Genome Atlas (TCGA) database. Screening of autophagy-related genes was conducted using the human autophagy database (HADb). Bioinformatic analysis was conducted and included the following: univariate cox, lasso regression, and multivariate cox regression analysis; building overall survival assessment of the prognosis model; drawing the model of receiver operating characteristic (ROC) curve and determining the area under the curve; and a C-index reliability index assessment model through Kaplan-Meier screening of statistically significant genes in the model. The screening results were verified via Oncomine differential expression analysis. Gene set enrichment analysis (GSEA) was further used to analyze the molecular biological functions and related pathways of the gene model. Results Through cox regression and ROC analysis, the model showed that the risk score could accurately and independently predict the prognosis of EAC. The screening identified 4 genes: DAPK1, BECN1, ATG5, and VAMP7. GSEA showed that the high and low expression levels of the 4 genes were mainly enriched in biological functions, such as cell production and regulation, and metabolic pathways that maintain cell activity. Conclusions Our research found that autophagy was involved in the process of EAC development and that several autophagy-related genes may provide prognostic information and clinical application value for patients with EAC.
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Affiliation(s)
- Tianfu Xu
- College of Medical Information Engineering, Anhui University of Chinese Medicine, Hefei, Anhui, China (mainland)
| | - Yamei Yuan
- College of Nursing, Anhui University of Chinese Medicine, Hefei, Anhui, China (mainland)
| | - Chenggong He
- Department of Clinical Medicine, The Second Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui, China (mainland)
| | - Kun Yang
- Department of Clinical Medicine, The Second Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui, China (mainland)
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12
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ELKS/Voltage-Dependent Ca 2+ Channel-β Subunit Module Regulates Polarized Ca 2+ Influx in Pancreatic β Cells. Cell Rep 2020; 26:1213-1226.e7. [PMID: 30699350 DOI: 10.1016/j.celrep.2018.12.106] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 10/29/2018] [Accepted: 12/27/2018] [Indexed: 12/14/2022] Open
Abstract
Pancreatic β cells secrete insulin by Ca2+-triggered exocytosis. However, there is no apparent secretory site similar to the neuronal active zones, and the cellular and molecular localization mechanism underlying polarized exocytosis remains elusive. Here, we report that ELKS, a vertebrate active zone protein, is used in β cells to regulate Ca2+ influx for insulin secretion. β cell-specific ELKS-knockout (KO) mice showed impaired glucose-stimulated first-phase insulin secretion and reduced L-type voltage-dependent Ca2+ channel (VDCC) current density. In situ Ca2+ imaging of β cells within islets expressing a membrane-bound G-CaMP8b Ca2+ sensor demonstrated initial local Ca2+ signals at the ELKS-localized vascular side of the β cell plasma membrane, which were markedly decreased in ELKS-KO β cells. Mechanistically, ELKS directly interacted with the VDCC-β subunit via the GK domain. These findings suggest that ELKS and VDCCs form a potent insulin secretion complex at the vascular side of the β cell plasma membrane for polarized Ca2+ influx and first-phase insulin secretion from pancreatic islets.
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Li F, Bahnson EM, Wilder J, Siletzky R, Hagaman J, Nickekeit V, Hiller S, Ayesha A, Feng L, Levine JS, Takahashi N, Maeda-Smithies N. Oral high dose vitamin B12 decreases renal superoxide and post-ischemia/reperfusion injury in mice. Redox Biol 2020; 32:101504. [PMID: 32182573 PMCID: PMC7078436 DOI: 10.1016/j.redox.2020.101504] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/27/2020] [Accepted: 03/09/2020] [Indexed: 01/25/2023] Open
Abstract
Renal ischemia/reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI), a potentially fatal syndrome characterized by a rapid decline in kidney function. Excess production of superoxide contributes to the injury. We hypothesized that oral administration of a high dose of vitamin B12 (B12 - cyanocobalamin), which possesses a superoxide scavenging function, would protect kidneys against IRI and provide a safe means of treatment. Following unilateral renal IR surgery, C57BL/6J wild type (WT) mice were administered B12 via drinking water at a dose of 50 mg/L. After 5 days of the treatment, plasma B12 levels increased by 1.2-1.5x, and kidney B12 levels increased by 7-8x. IRI mice treated with B12 showed near normal renal function and morphology. Further, IRI-induced changes in RNA and protein markers of inflammation, fibrosis, apoptosis, and DNA damage response (DDR) were significantly attenuated by at least 50% compared to those in untreated mice. Moreover, the presence of B12 at 0.3 μM in the culture medium of mouse proximal tubular cells subjected to 3 hr of hypoxia followed by 1 hr of reperfusion in vitro showed similar protective effects, including increased cell viability and decreased reactive oxygen species (ROS) level. We conclude that a high dose of B12 protects against perfusion injury both in vivo and in vitro without observable adverse effects in mice and suggest that B12 merits evaluation as a treatment for I/R-mediated AKI in humans.
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Affiliation(s)
- Feng Li
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Edward M Bahnson
- Department of Surgery, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jennifer Wilder
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Robin Siletzky
- Department of Surgery, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - John Hagaman
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Volker Nickekeit
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA; Division of Nephropathy, School of Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Sylvia Hiller
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Azraa Ayesha
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Lanfei Feng
- Section of Nephrology, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Chicago, IL, 60612, USA
| | - Jerrold S Levine
- Section of Nephrology, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Chicago, IL, 60612, USA
| | - Nobuyuki Takahashi
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA; Division of Clinical Pharmacology and Therapeutics, Tohoku University Graduate School, Sendai, Japan
| | - Nobuyo Maeda-Smithies
- Dept of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, NC, 27599, USA
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Tang BL. Syntaxin 16's Newly Deciphered Roles in Autophagy. Cells 2019; 8:cells8121655. [PMID: 31861136 PMCID: PMC6953085 DOI: 10.3390/cells8121655] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 12/16/2022] Open
Abstract
Syntaxin 16, a Qa-SNARE (soluble N-ethylmaleimide-sensitive factor activating protein receptor), is involved in a number of membrane-trafficking activities, particularly transport processes at the trans-Golgi network (TGN). Recent works have now implicated syntaxin 16 in the autophagy process. In fact, syntaxin 16 appears to have dual roles, firstly in facilitating the transport of ATG9a-containing vesicles to growing autophagosomes, and secondly in autolysosome formation. The former involves a putative SNARE complex between syntaxin 16, VAMP7 and SNAP-47. The latter occurs via syntaxin 16’s recruitment by Atg8/LC3/GABARAP family proteins to autophagosomes and endo-lysosomes, where syntaxin 16 may act in a manner that bears functional redundancy with the canonical autophagosome Qa-SNARE syntaxin 17. Here, I discuss these recent findings and speculate on the mechanistic aspects of syntaxin 16’s newly found role in autophagy.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore; ; Tel.: +65-6516-1040
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore
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15
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Zhou J, Kang X, Luo Y, Yuan Y, Wu Y, Wang M, Liu D. Glibenclamide-Induced Autophagy Inhibits Its Insulin Secretion-Improving Function in β Cells. Int J Endocrinol 2019; 2019:1265175. [PMID: 31511772 PMCID: PMC6714319 DOI: 10.1155/2019/1265175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/01/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetes is a metabolic disease, partly due to hypoinsulinism, which affects ∼8% of the world's adult population. Glibenclamide is known to promote insulin secretion by targeting β cells. Autophagy as a self-protective mechanism of cells has been widely studied and has particular physiological effects in different tissues or cells. However, the interaction between autophagy and glibenclamide is unclear. In this study, we investigated the role of autophagy in glibenclamide-induced insulin secretion in pancreatic β cells. Herein, we showed that glibenclamide promoted insulin release and further activated autophagy through the adenosine 5'-monophosphate (AMP) activated protein kinase (AMPK) pathway in MIN-6 cells. Inhibition of autophagy with autophagy inhibitor 3-methyladenine (3-MA) potentiated the secretory function of glibenclamide further. These results suggest that glibenclamide-induced autophagy plays an inhibitory role in promoting insulin secretion by activating the AMPK pathway instead of altering the mammalian target of rapamycin (mTOR).
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Affiliation(s)
- Jiali Zhou
- Horticulture and Landscape College, Hunan Agricultural University, Changsha 410128, China
- State Key Laboratory of Subhealth Intervention Technology, Changsha 410128, China
| | - Xincong Kang
- Horticulture and Landscape College, Hunan Agricultural University, Changsha 410128, China
- State Key Laboratory of Subhealth Intervention Technology, Changsha 410128, China
| | - Yushuang Luo
- Horticulture and Landscape College, Hunan Agricultural University, Changsha 410128, China
- State Key Laboratory of Subhealth Intervention Technology, Changsha 410128, China
| | - Yuju Yuan
- College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Yanyang Wu
- College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Meijun Wang
- Horticulture and Landscape College, Hunan Agricultural University, Changsha 410128, China
| | - Dongbo Liu
- Horticulture and Landscape College, Hunan Agricultural University, Changsha 410128, China
- State Key Laboratory of Subhealth Intervention Technology, Changsha 410128, China
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha 410128, China
- Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha 410128, China
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16
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Aoyagi K, Itakura M, Fukutomi T, Nishiwaki C, Nakamichi Y, Torii S, Makiyama T, Harada A, Ohara-Imaizumi M. VAMP7 Regulates Autophagosome Formation by Supporting Atg9a Functions in Pancreatic β-Cells From Male Mice. Endocrinology 2018; 159:3674-3688. [PMID: 30215699 DOI: 10.1210/en.2018-00447] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 09/05/2018] [Indexed: 12/24/2022]
Abstract
Dysfunctional mitochondria are observed in β-cells of diabetic patients, which are eventually removed by autophagy. Vesicle-associated membrane protein (VAMP)7, a vesicular SNARE protein, regulates autophagosome formation to maintain mitochondrial homeostasis and control insulin secretion in pancreatic β-cells. However, its molecular mechanism is largely unknown. In this study, we investigated the molecular mechanism of VAMP7-dependent autophagosome formation using VAMP7-deficient β-cells and β-cell-derived Min6 cells. VAMP7 localized in autophagy-related (Atg)9a-resident vesicles of recycling endosomes (REs), which contributed to autophagosome formation, and it interacted with Hrb, Syntaxin16, and SNAP-47. Hrb recruited VAMP7 and Atg9a from the plasma membrane to REs. Syntaxin16 and SNAP-47 mediated autophagosome formation at a step later than the proper localization of VAMP7 to Atg9a-resident vesicles. Knockdown of Hrb, Syntaxin16, and SNAP-47 resulted in defective autophagosome formation, accumulation of dysfunctional mitochondria, and impairment of glucose-stimulated insulin secretion. Our data indicate that VAMP7 and Atg9a are initially recruited to REs to organize VAMP7 and Atg9a-resident vesicles in an Hrb-dependent manner. Additionally, VAMP7 forms a SNARE complex with Syntaxin16 and SNAP-47, which may cause fusions of Atg9a-resident vesicles during autophagosome formation. Thus, VAMP7 participates in autophagosome formation by supporting Atg9a functions that contribute to maintenance of mitochondrial quality.
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Affiliation(s)
- Kyota Aoyagi
- Department of Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Makoto Itakura
- Department of Biochemistry, Kitasato University School of Medicine, Kanagawa, Japan
| | - Toshiyuki Fukutomi
- Department of Pharmacology, Kyorin University School of Medicine, Tokyo, Japan
| | - Chiyono Nishiwaki
- Department of Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Yoko Nakamichi
- Department of Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Seiji Torii
- Biosignal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Tomohiko Makiyama
- Department of Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
| | - Akihiro Harada
- Department of Cell Biology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mica Ohara-Imaizumi
- Department of Biochemistry, Kyorin University School of Medicine, Tokyo, Japan
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17
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Bhattacharya D, Mukhopadhyay M, Bhattacharyya M, Karmakar P. Is autophagy associated with diabetes mellitus and its complications? A review. EXCLI JOURNAL 2018; 17:709-720. [PMID: 30190661 PMCID: PMC6123605 DOI: 10.17179/excli2018-1353] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/11/2018] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus (DM) is an endocrine disorder. In coming decades it will be one of the leading causes of death globally. The key factors in the pathogenesis of diabetes are cellular injuries and disorders of energy metabolism leading to severe diabetic complications. Recent studies have confirmed that autophagy plays a pivotal role in diabetes and its complications. It has been observed that autophagy regulates the normal function of pancreatic β cells and insulin-target tissues, such as skeletal muscle, liver, and adipose tissue. This review will summarize the regulation of autophagy in diabetes and its complications, and explore how this process would emerge as a potential therapeutic target for diabetes treatment.
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Affiliation(s)
- Debalina Bhattacharya
- Department of Biochemistry, University of Calcutta, Kolkata-700019
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata-700032
| | | | | | - Parimal Karmakar
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata-700032
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18
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Abstract
Obesity poses a severe threat to human health, including the increased prevalence of hypertension, insulin resistance, diabetes mellitus, cancer, inflammation, sleep apnoea and other chronic diseases. Current therapies focus mainly on suppressing caloric intake, but the efficacy of this approach remains poor. A better understanding of the pathophysiology of obesity will be essential for the management of obesity and its complications. Knowledge gained over the past three decades regarding the aetiological mechanisms underpinning obesity has provided a framework that emphasizes energy imbalance and neurohormonal dysregulation, which are tightly regulated by autophagy. Accordingly, there is an emerging interest in the role of autophagy, a conserved homeostatic process for cellular quality control through the disposal and recycling of cellular components, in the maintenance of cellular homeostasis and organ function by selectively ridding cells of potentially toxic proteins, lipids and organelles. Indeed, defects in autophagy homeostasis are implicated in metabolic disorders, including obesity, insulin resistance, diabetes mellitus and atherosclerosis. In this Review, the alterations in autophagy that occur in response to nutrient stress, and how these changes alter the course of obesogenesis and obesity-related complications, are discussed. The potential of pharmacological modulation of autophagy for the management of obesity is also addressed.
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Affiliation(s)
- Yingmei Zhang
- Department of Cardiology, Fudan University Zhongshan Hospital, Shanghai, China.
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY, USA.
| | - James R Sowers
- Diabetes and Cardiovascular Research Center, University of Missouri-Columbia School of Medicine, Columbia, MO, USA
| | - Jun Ren
- Department of Cardiology, Fudan University Zhongshan Hospital, Shanghai, China.
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY, USA.
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A large-scale RNA interference screen identifies genes that regulate autophagy at different stages. Sci Rep 2018; 8:2822. [PMID: 29434216 PMCID: PMC5809370 DOI: 10.1038/s41598-018-21106-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/30/2018] [Indexed: 12/20/2022] Open
Abstract
Dysregulated autophagy is central to the pathogenesis and therapeutic development of cancer. However, how autophagy is regulated in cancer is not well understood and genes that modulate cancer autophagy are not fully defined. To gain more insights into autophagy regulation in cancer, we performed a large-scale RNA interference screen in K562 human chronic myeloid leukemia cells using monodansylcadaverine staining, an autophagy-detecting approach equivalent to immunoblotting of the autophagy marker LC3B or fluorescence microscopy of GFP-LC3B. By coupling monodansylcadaverine staining with fluorescence-activated cell sorting, we successfully isolated autophagic K562 cells where we identified 336 short hairpin RNAs. After candidate validation using Cyto-ID fluorescence spectrophotometry, LC3B immunoblotting, and quantitative RT-PCR, 82 genes were identified as autophagy-regulating genes. 20 genes have been reported previously and the remaining 62 candidates are novel autophagy mediators. Bioinformatic analyses revealed that most candidate genes were involved in molecular pathways regulating autophagy, rather than directly participating in the autophagy process. Further autophagy flux assays revealed that 57 autophagy-regulating genes suppressed autophagy initiation, whereas 21 candidates promoted autophagy maturation. Our RNA interference screen identified genes that regulate autophagy at different stages, which helps decode autophagy regulation in cancer and offers novel avenues to develop autophagy-related therapies for cancer.
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Papandreou ME, Tavernarakis N. Autophagy and the endo/exosomal pathways in health and disease. Biotechnol J 2016; 12. [DOI: 10.1002/biot.201600175] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/06/2016] [Accepted: 11/21/2016] [Indexed: 01/26/2023]
Affiliation(s)
- Margarita-Elena Papandreou
- Institute of Molecular Biology and Biotechnology; Foundation for Research and Technology - Hellas, Heraklion; Greece
- Department of Basic Sciences, Faculty of Medicine; University of Crete; Heraklion Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology; Foundation for Research and Technology - Hellas, Heraklion; Greece
- Department of Basic Sciences, Faculty of Medicine; University of Crete; Heraklion Greece
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