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Zhang K, Bao R, Huang F, Yang K, Ding Y, Lauterboeck L, Yoshida M, Long Q, Yang Q. ATP synthase inhibitory factor subunit 1 regulates islet β-cell function via repression of mitochondrial homeostasis. J Transl Med 2022; 102:69-79. [PMID: 34608240 PMCID: PMC9198815 DOI: 10.1038/s41374-021-00670-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial homeostasis is crucial for the function of pancreatic β-cells. ATP synthase inhibitory factor subunit 1 (IF1) is a mitochondrial protein interacting with ATP synthase to inhibit its enzyme activity. IF1 may also play a role in maintaining ATP synthase oligomerization and mitochondrial inner membrane formation. A recent study confirmed IF1 expresses in β-cells. IF1 knockdown in cultured INS-1E β-cells enhances glucose-induced insulin release. However, the role of IF1 in islet β-cells remains little known. The present study investigates islets freshly isolated from mouse lines with global IF1 knockout (IF1-/-) and overexpression (OE). The glucose-stimulated insulin secretion was increased in islets from IF1-/- mice but decreased in islets from IF1 OE mice. Transmitted Electronic Microscopic assessment of isolated islets revealed that the number of matured insulin granules (with dense core) was relatively higher in IF1-/-, but fewer in IF1 OE islets than those of controlled islets. The mitochondrial ultrastructure within β-cells of IF1 overexpressed islets was comparable with those of wild-type mice, whereas those in IF1-/- β-cells showed increased mitochondrial mass. Mitochondrial network analysis in cultured INS-1 β-cells showed a similar pattern with an increased mitochondrial network in IF1 knockdown cells. IF1 overexpressed INS-1 β-cells showed a compromised rate of mitochondrial oxidative phosphorylation with attenuated cellular ATP content. In contrast, INS-1 cells with IF1 knockdown showed markedly increased cellular respiration with improved ATP production. These results support that IF1 is a negative regulator of insulin production and secretion via inhibiting mitochondrial mass and respiration in β-cells. Therefore, inhibiting IF1 to improve β-cell function in patients can be a novel therapeutic strategy to treat diabetes.
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Affiliation(s)
- Kailiang Zhang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rong Bao
- Cardiovascular Center of Excellence and Department of Pharmacology, Louisiana State University Health Science Center New Orleans, New Orleans, LA, USA
| | - Fengyuan Huang
- Department of Nutrition Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kevin Yang
- Department of Nutrition Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yishu Ding
- Department of Nutrition Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lothar Lauterboeck
- Cardiovascular Center of Excellence and Department of Pharmacology, Louisiana State University Health Science Center New Orleans, New Orleans, LA, USA
| | - Masasuke Yoshida
- Department of Molecular Bioscience, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Qinqiang Long
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
- Department of Nutrition Science, University of Alabama at Birmingham, Birmingham, AL, USA.
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, China.
| | - Qinglin Yang
- Cardiovascular Center of Excellence and Department of Pharmacology, Louisiana State University Health Science Center New Orleans, New Orleans, LA, USA.
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Sumi K, Okura T, Fujioka Y, Kato M, Imamura T, Taniguchi SI, Yamamoto K. Coenzyme Q10 suppresses apoptosis of mouse pancreatic β-cell line MIN6. Diabetol Metab Syndr 2018; 10:47. [PMID: 29942356 PMCID: PMC6000937 DOI: 10.1186/s13098-018-0351-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/05/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND In mitochondrial diabetes, apoptosis of β-cells caused by mitochondrial stress plays an important role in impaired insulin secretion. Several studies have reported that coenzyme Q10 (CoQ10) has therapeutic effects on mitochondrial diabetes, but no reports have examined the fundamental effectiveness or mechanism of CoQ10 in mitochondrial diabetes. We previously reported in a Japanese article that CoQ10 has protective effects on pancreatic β-cells against mitochondrial stress using mouse pancreatic β-cell line MIN6 and staurosporine (STS). Here, we report that CoQ10 protects MIN6 cells against apoptosis caused by STS and describe the more detailed apoptotic cascade. METHODS Apoptosis of MIN6 cells was induced by 0.5 µM STS treatment for specific periods with or without 30 μM CoQ10. The apoptosis cascade in MIN6 cells was then investigated using WST-8 assays, annexin-V staining, western blotting, and DNA degradation analysis. RESULTS Sixteen hours of 0.5 μM STS treatment led to 47% cell viability, but pretreatment with 30 μM CoQ10 resulted in significantly higher viability of 76% (P < 0.01). CoQ10 also prevented translocation of phosphatidylserine from the inner leaflet to the outer leaflet of the cell membrane. CoQ10 prevented cytochrome c release from mitochondria and activation of caspase-3. CONCLUSION We concluded that CoQ10 protects pancreatic β-cells through anti-apoptotic effects against STS treatment.
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Affiliation(s)
- Keisuke Sumi
- Division of Endocrinology and Metabolism, Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, 36-1 Nishi-chou, Yonago, Tottori 683-8504 Japan
| | - Tsuyoshi Okura
- Division of Endocrinology and Metabolism, Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, 36-1 Nishi-chou, Yonago, Tottori 683-8504 Japan
| | - Youhei Fujioka
- Division of Endocrinology and Metabolism, Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, 36-1 Nishi-chou, Yonago, Tottori 683-8504 Japan
| | - Masahiko Kato
- Division of Cardiovascular Medicine, Endocrinology and Metabolism, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8504 Japan
| | - Takeshi Imamura
- Division of Molecular Pharmacology, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8504 Japan
| | - Shin-ichi Taniguchi
- Department of Regional Medicine, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8504 Japan
| | - Kazuhiro Yamamoto
- Division of Cardiovascular Medicine, Endocrinology and Metabolism, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8504 Japan
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ATP synthase β-subunit abnormality in pancreas islets of rats with polycystic ovary syndrome and type 2 diabetes mellitus. ACTA ACUST UNITED AC 2017; 37:210-216. [PMID: 28397049 DOI: 10.1007/s11596-017-1717-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/06/2017] [Indexed: 10/18/2022]
Abstract
This study investigated the abnormal expression of ATP synthase β-subunit (ATPsyn-β) in pancreas islets of rat model of polycystic ovary syndrome (PCOS) with type 2 diabetes mellitus (T2DM), and the secretion function changes after up-regulation of ATP5b. Sixty female SD rats were divided into three groups randomly and equally. The rat model of PCOS with T2DM was established by free access to the high-carbohydrate/high-fat diet, subcutaneous injections of DHEA, and a single injection of streptozotocin. The pancreas was removed for the detection of the ATPsyn-β expression by immunohistochemical staining, Western blotting and reverse transcription-PCR (RT-PCR). The pancreas islets of the rats were cultured, isolated with collagenase V and purified by gradient centrifugation, and the insulin secretion after treatment with different glucose concentrations was tested. Lentivirus ATP5b was successfully constructed with the vector of GV208 and transfected into the pancreas islets for the over-expression of ATPsyn-β. The insulin secretion and intracellular ATP content were determined after transfection of the PCOS-T2DM pancreas islets with Lenti-ATP5b. The results showed that the expression of ATPsyn-β protein and mRNA was significantly decreased in the pancreas of PCOS-T2DM rats. The ATP content in the pancreas islets was greatly increased and the insulin secretion was improved after the up-regulation of ATPsyn-β in the pancreas islets transfected with lenti-ATP5b. These results indicated that for PCOS, the ATPsyn-β might be one of the key factors for the attack of T2DM.
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Chen F, Sha M, Wang Y, Wu T, Shan W, Liu J, Zhou W, Zhu Y, Sun Y, Shi Y, Bleich D, Han X. Transcription factor Ets-1 links glucotoxicity to pancreatic beta cell dysfunction through inhibiting PDX-1 expression in rodent models. Diabetologia 2016; 59:316-24. [PMID: 26564177 DOI: 10.1007/s00125-015-3805-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/14/2015] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS 'Glucotoxicity' is a term used to convey the negative effect of hyperglycaemia on beta cell function; however, the underlying molecular mechanisms that impair insulin secretion and gene expression are poorly defined. Our objective was to define the role of transcription factor v-ets avian erythroblastosis virus E26 oncogene homologue 1 (Ets-1) in beta cell glucotoxicity. METHODS Primary islets and Min6 cells were exposed to high glucose and Ets-1 expression was measured. Recombinant adenovirus and transgenic mice were used to upregulate Ets-1 expression in beta cells in vitro and in vivo, and insulin secretion was assessed. The binding activity of H3/H4 histone on the Ets-1 promoter, and that of forkhead box (FOX)A2, FOXO1 and Ets-1 on the Pdx-1 promoter was measured by chromatin immunoprecipitation and quantitative real-time PCR assay. RESULTS High glucose induced upregulation of Ets-1 expression and hyperacetylation of histone H3 and H4 at the Ets-1 gene promoter in beta cells. Ets-1 overexpression dramatically suppressed insulin secretion and biosynthesis both in vivo and in vitro. Besides, Ets-1 overexpression increased the activity of FOXO1 but decreased that of FOXA2 binding to the pancreatic and duodenal homeobox 1 (PDX-1) homology region 2 (PH2), resulting in inhibition of Pdx-1 promoter activity and downregulation of PDX-1 expression and activity. In addition, high glucose promoted the interaction of Ets-1 and FOXO1, and the activity of Ets-1 binding to the Pdx-1 promoter. Importantly, PDX-1 overexpression reversed the defect in pancreatic beta cells induced by Ets-1 excess, while knockdown of Ets-1 prevented hyperglycaemia-induced dysfunction of pancreatic beta cells. CONCLUSIONS/INTERPRETATION Our observations suggest that Ets-1 links glucotoxicity to pancreatic beta cell dysfunction through inhibiting PDX-1 expression in type 2 diabetes.
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MESH Headings
- Animals
- Blood Glucose/physiology
- Cells, Cultured
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Gene Expression Regulation
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Hyperglycemia/blood
- Hyperglycemia/genetics
- Hyperglycemia/physiopathology
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Proto-Oncogene Protein c-ets-1/physiology
- Rats
- Rats, Sprague-Dawley
- Trans-Activators/genetics
- Trans-Activators/metabolism
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Affiliation(s)
- Fang Chen
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Min Sha
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Yanyang Wang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Tijun Wu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Wei Shan
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Jia Liu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Wenbo Zhou
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Yunxia Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Yujie Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China
| | - Yuguang Shi
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, TX, USA
| | - David Bleich
- Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, 140 Hanzhong Road, Nanjing, 210029, People's Republic of China.
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Guan SS, Sheu ML, Wu CT, Chiang CK, Liu SH. ATP synthase subunit-β down-regulation aggravates diabetic nephropathy. Sci Rep 2015; 5:14561. [PMID: 26449648 PMCID: PMC4598833 DOI: 10.1038/srep14561] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 09/03/2015] [Indexed: 01/14/2023] Open
Abstract
In this study, we investigated the role of ATP synthase subunit-β (ATP5b) in diabetic nephropathy. Histopathological changes, fibrosis, and protein expressions of α-smooth muscle actin (α-SMA), advanced glycation end-products (AGEs), and ATP5b were obviously observed in the kidneys of db/db diabetic mice as compared with the control db/m(+) mice. The increased ATP5b expression was majorly observed in diabetic renal tubules and was notably observed to locate in cytoplasm of tubule cells, but no significant increase of ATP5b in diabetic glomeruli. AGEs significantly increased protein expression of ATP5b and fibrotic factors and decreased ATP content in cultured renal tubular cells via an AGEs-receptor for AGEs (RAGE) axis pathway. Oxidative stress was also induced in diabetic kidneys and AGEs-treated renal tubular cells. The increase of ATP5b and CTGF protein expression in AGEs-treated renal tubular cells was reversed by antioxidant N-acetylcysteine. ATP5b-siRNA transfection augmented the increased protein expression of α-SMA and CTGF and CTGF promoter activity in AGEs-treated renal tubular cells. The in vivo ATP5b-siRNA delivery significantly enhanced renal fibrosis and serum creatinine in db/db mice with ATP5b down-regulation. These findings suggest that increased ATP5b plays an important adaptive or protective role in decreasing the rate of AGEs-induced renal fibrosis during diabetic condition.
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Affiliation(s)
- Siao-Syun Guan
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Institute of Nuclear Energy Research, Atomic Energy Council, Executive Yuan, Taoyuan, Taiwan
| | - Meei-Ling Sheu
- Biomedical Sciences, College of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Cheng-Tien Wu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chih-Kang Chiang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Departments of Integrated Diagnostics &Therapeutics and Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
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6
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Hashemi Z, Yang K, Yang H, Jin A, Ozga J, Chan CB. Cooking enhances beneficial effects of pea seed coat consumption on glucose tolerance, incretin, and pancreatic hormones in high-fat-diet-fed rats. Appl Physiol Nutr Metab 2015; 40:323-33. [PMID: 25794240 DOI: 10.1139/apnm-2014-0380] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Pulses, including dried peas, are nutrient- and fibre-rich foods that improve glucose control in diabetic subjects compared with other fibre sources. We hypothesized feeding cooked pea seed coats to insulin-resistant rats would improve glucose tolerance by modifying gut responses to glucose and reducing stress on pancreatic islets. Glucose intolerance induced in male Sprague-Dawley rats with high-fat diet (HFD; 10% cellulose as fibre) was followed by 3 weeks of HFD with fibre (10%) provided by cellulose, raw-pea seed coat (RP), or cooked-pea seed coat (CP). A fourth group consumed low-fat diet with 10% cellulose. Oral and intraperitoneal glucose tolerance tests (oGTT, ipGTT) were done. CP rats had 30% and 50% lower glucose and insulin responses in oGTT, respectively, compared with the HFD group (P < 0.05) but ipGTT was not different. Plasma islet and incretin hormone concentrations were measured. α- and β-cell areas in the pancreas and density of K- and L-cells in jejunum and ileum were quantified. Jejunal expression of hexose transporters was measured. CP feeding increased fasting glucagon-like peptide 1 and glucose-stimulated gastric inhibitory polypeptide responses (P < 0.05), but K- and L-cells densities were comparable to HFD, as was abundance of SGLT1 and GLUT2 mRNA. No significant difference in β-cell area between diet groups was observed. α-cell area was significantly smaller in CP compared with RP rats (P < 0.05). Overall, our results demonstrate that CP feeding can reverse adverse effects of HFD on glucose homeostasis and is associated with enhanced incretin secretion and reduced α-cell abundance.
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Affiliation(s)
- Zohre Hashemi
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada
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7
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Di Cara F, Duca E, Dunbar DR, Cagney G, Heck MMS. Invadolysin, a conserved lipid-droplet-associated metalloproteinase, is required for mitochondrial function in Drosophila. J Cell Sci 2013; 126:4769-81. [PMID: 23943867 DOI: 10.1242/jcs.133306] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are the main producers of ATP, the principal energy source of the cell, and reactive oxygen species (ROS), important signaling molecules. Mitochondrial morphogenesis and function depend on a hierarchical network of mechanisms in which proteases appear to be center stage. The invadolysin gene encodes an essential conserved metalloproteinase of the M8 family that is necessary for mitosis and cell migration during Drosophila development. We previously demonstrated that invadolysin is found associated with lipid droplets in cells. Here, we present data demonstrating that invadolysin interacts physically with three mitochondrial ATP synthase subunits. Our studies have focused on the genetic phenotypes of invadolysin and bellwether, the Drosophila homolog of ATP synthase α, mutants. The invadolysin mutation presents defects in mitochondrial physiology similar to those observed in bellwether mutants. The invadolysin and bellwether mutants have parallel phenotypes that affect lipid storage and mitochondrial electron transport chain activity, which result in a reduction in ATP production and an accumulation of ROS. As a consequence, invadolysin mutant larvae show lower energetic status and higher oxidative stress. Our data demonstrate an essential role for invadolysin in mitochondrial function that is crucial for normal development and survival.
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Affiliation(s)
- Francesca Di Cara
- University of Edinburgh, Queen's Medical Research Institute, BHF/University Center for Cardiovascular Science, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
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8
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Harasym AC, Thrush AB, Harper ME, Wright DC, Chan CB. Enhanced glucose homeostasis in BHE/cdb rats with mutated ATP synthase. Mitochondrion 2013; 13:320-9. [DOI: 10.1016/j.mito.2013.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 03/06/2013] [Accepted: 04/03/2013] [Indexed: 10/27/2022]
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9
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Bhasin MK, Dusek JA, Chang BH, Joseph MG, Denninger JW, Fricchione GL, Benson H, Libermann TA. Relaxation response induces temporal transcriptome changes in energy metabolism, insulin secretion and inflammatory pathways. PLoS One 2013; 8:e62817. [PMID: 23650531 PMCID: PMC3641112 DOI: 10.1371/journal.pone.0062817] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 03/26/2013] [Indexed: 01/08/2023] Open
Abstract
The relaxation response (RR) is the counterpart of the stress response. Millennia-old practices evoking the RR include meditation, yoga and repetitive prayer. Although RR elicitation is an effective therapeutic intervention that counteracts the adverse clinical effects of stress in disorders including hypertension, anxiety, insomnia and aging, the underlying molecular mechanisms that explain these clinical benefits remain undetermined. To assess rapid time-dependent (temporal) genomic changes during one session of RR practice among healthy practitioners with years of RR practice and also in novices before and after 8 weeks of RR training, we measured the transcriptome in peripheral blood prior to, immediately after, and 15 minutes after listening to an RR-eliciting or a health education CD. Both short-term and long-term practitioners evoked significant temporal gene expression changes with greater significance in the latter as compared to novices. RR practice enhanced expression of genes associated with energy metabolism, mitochondrial function, insulin secretion and telomere maintenance, and reduced expression of genes linked to inflammatory response and stress-related pathways. Interactive network analyses of RR-affected pathways identified mitochondrial ATP synthase and insulin (INS) as top upregulated critical molecules (focus hubs) and NF-κB pathway genes as top downregulated focus hubs. Our results for the first time indicate that RR elicitation, particularly after long-term practice, may evoke its downstream health benefits by improving mitochondrial energy production and utilization and thus promoting mitochondrial resiliency through upregulation of ATPase and insulin function. Mitochondrial resiliency might also be promoted by RR-induced downregulation of NF-κB-associated upstream and downstream targets that mitigates stress.
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Affiliation(s)
- Manoj K. Bhasin
- Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- BIDMC Genomics and Proteomics Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Jeffery A. Dusek
- Institute for Health and Healing, Abbott Northwestern Hospital, Minneapolis, Minnesota, United States of America
| | - Bei-Hung Chang
- VA Boston Healthcare System, Boston, Massachusetts, United States of America
- Department of Health Policy and Management, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Marie G. Joseph
- BIDMC Genomics and Proteomics Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - John W. Denninger
- Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gregory L. Fricchione
- Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Herbert Benson
- Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Towia A. Libermann
- Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- BIDMC Genomics and Proteomics Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
- * E-mail:
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10
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Whitlock KA, Kozicky L, Jin A, Yee H, Ha C, Morris J, Field CJ, Bell RC, Ozga JA, Chan CB. Assessment of the mechanisms exerting glucose-lowering effects of dried peas in glucose-intolerant rats. Br J Nutr 2012; 108 Suppl 1:S91-102. [PMID: 22916820 DOI: 10.1017/s0007114512000736] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present study compared the effects of feeding uncooked pea fractions (embryo v. seed coat) on glucose homeostasis in glucose-intolerant rats and examined potential mechanisms influencing glucose homeostasis. Rats were made glucose intolerant by high-fat feeding, after which diets containing both high-fat and pea fractions were fed for 4 weeks. Rats fed diets containing uncooked pea seed coats low (non-coloured seed coat; NSC) or high (coloured seed coat; CSC) in proanthocyanidins but not embryos had improved oral glucose tolerance (P < 0·05). NSC also lowered fasting and glucose-stimulated insulin secretion (P < 0·05), decreased β-cell mass by 50 % (P < 0·05) and lowered levels of malondialdehyde, a marker of oxidative stress. Furthermore, NSC decreased the mucosal thickness of the colon by 25 % (P < 0·05), which might affect fibre fermentation and other gut functions. Small but statistically significant (P < 0·05) effects consistent with enhanced glucose transport or metabolism were observed in the skeletal muscle of rats fed NSC or CSC, for example, increased levels of AMP-dependent kinase or akt. We conclude that pea seed coats are the fraction exerting beneficial effects on glucose tolerance. Most of the changes were small in amplitude, suggesting that additive effects on multiple tissues may be important. NSC content appeared to have the most beneficial effects in improving glucose homeostasis but our ability to detect the effect of flavonoids may have been limited by their low concentration in the diet.
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Affiliation(s)
- Kevin A Whitlock
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada T6G 2R3
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11
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AMPK enhances the expression of pancreatic duodenal homeobox-1 via PPARalpha, but not PPARgamma, in rat insulinoma cell line INS-1. Acta Pharmacol Sin 2010; 31:963-9. [PMID: 20644547 DOI: 10.1038/aps.2010.78] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIM To investigate whether AMP-activated protein kinase (AMPK) regulates the expression of pancreatic duodenal homeobox-1 (PDX-1), a beta-cell-specific transcription factor and whether PPARalpha/gamma is involved in the regulation of pancreatic beta-cell lines after acute stimulation. METHODS Rat insulinoma cell line INS-1 was treated with an activator (AICAR) or inhibitor (Compound C) of AMPK as well as inhibitors of PPARs (MK886 to PPARalpha and BADGE to PPARgamma). The mRNA levels of PDX-1, PPARalpha and PPARgamma were measured using real-time RT-PCR, and Western blotting was used to detect the protein expression of these factors. RESULTS Activation of AMPK by AICAR induced significantly increased the expression of PDX-1, and this increase was abrogated when AMPK was inactivated by Compound C. Similarly, the expression of PPARalpha and PPARgamma was also increased by AICAR or decreased by Compound C. However AMPK activation did not increase nuclear PDX-1 protein levels when PPARalpha was inhibited. In contrast, AMPK activation still up-regulated PDX-1 protein levels during PPARgamma inhibition. Additionally, PPARalpha activation induced by fenofibrate significantly enhanced nuclear PDX-1 protein expression. CONCLUSION AMPK regulates the expression of PDX-1 at both the transcriptional and protein levels, and PPARalpha may be acutely involved in the regulation of INS-1 cells.
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12
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Fridlyand LE, Philipson LH. Glucose sensing in the pancreatic beta cell: a computational systems analysis. Theor Biol Med Model 2010; 7:15. [PMID: 20497556 PMCID: PMC2896931 DOI: 10.1186/1742-4682-7-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 05/24/2010] [Indexed: 12/29/2022] Open
Abstract
Background Pancreatic beta-cells respond to rising blood glucose by increasing oxidative metabolism, leading to an increased ATP/ADP ratio in the cytoplasm. This leads to a closure of KATP channels, depolarization of the plasma membrane, influx of calcium and the eventual secretion of insulin. Such mechanism suggests that beta-cell metabolism should have a functional regulation specific to secretion, as opposed to coupling to contraction. The goal of this work is to uncover contributions of the cytoplasmic and mitochondrial processes in this secretory coupling mechanism using mathematical modeling in a systems biology approach. Methods We describe a mathematical model of beta-cell sensitivity to glucose. The cytoplasmic part of the model includes equations describing glucokinase, glycolysis, pyruvate reduction, NADH and ATP production and consumption. The mitochondrial part begins with production of NADH, which is regulated by pyruvate dehydrogenase. NADH is used in the electron transport chain to establish a proton motive force, driving the F1F0 ATPase. Redox shuttles and mitochondrial Ca2+ handling were also modeled. Results The model correctly predicts changes in the ATP/ADP ratio, Ca2+ and other metabolic parameters in response to changes in substrate delivery at steady-state and during cytoplasmic Ca2+ oscillations. Our analysis of the model simulations suggests that the mitochondrial membrane potential should be relatively lower in beta cells compared with other cell types to permit precise mitochondrial regulation of the cytoplasmic ATP/ADP ratio. This key difference may follow from a relative reduction in respiratory activity. The model demonstrates how activity of lactate dehydrogenase, uncoupling proteins and the redox shuttles can regulate beta-cell function in concert; that independent oscillations of cytoplasmic Ca2+ can lead to slow coupled metabolic oscillations; and that the relatively low production rate of reactive oxygen species in beta-cells under physiological conditions is a consequence of the relatively decreased mitochondrial membrane potential. Conclusion This comprehensive model predicts a special role for mitochondrial control mechanisms in insulin secretion and ROS generation in the beta cell. The model can be used for testing and generating control hypotheses and will help to provide a more complete understanding of beta-cell glucose-sensing central to the physiology and pathology of pancreatic β-cells.
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Affiliation(s)
- Leonid E Fridlyand
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA.
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Yu X, Wester-Rosenlöf L, Gimsa U, Holzhueter SA, Marques A, Jonas L, Hagenow K, Kunz M, Nizze H, Tiedge M, Holmdahl R, Ibrahim SM. The mtDNA nt7778 G/T polymorphism affects autoimmune diseases and reproductive performance in the mouse. Hum Mol Genet 2009; 18:4689-98. [PMID: 19759059 DOI: 10.1093/hmg/ddp432] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mitochondria are organelles of all nucleated cells, and variations in mtDNA sequence affect a wide spectrum of human diseases. However, animal models for mtDNA-associated diseases are rare, making it challenging to explore mechanisms underlying the contribution of mitochondria. Here, we identify a polymorphism in the mitochondrial genome, G-to-T at position 7778, which results in an aspartic acid-to-tyrosine (D-Y) substitution in the fifth amino acid of the highly conserved N-terminus of ATP synthase 8 (ATP8). Using a series of conplastic strains we show that this polymorphism increases susceptibility to multiple autoimmune diseases, including collagen-induced arthritis, autoimmune diabetes, nephritis and autoimmune pancreatitis. In addition, it impairs reproductive performance in females, but only in the MRL/MpJ strain. We also demonstrate that the mtAtp8 polymorphism alters mitochondrial performance, increasing H(2)O(2) production and affecting mitochondrial structure. Functional analysis reveals that the polymorphism increase the CD4 T cell adaptive potential to an oxidative phosphorylation impaired condition. Our findings provide direct experimental evidence for the role of mitochondria in autoimmunity and reproduction.
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Affiliation(s)
- Xinhua Yu
- Section of Immunogenetics, University of Rostock, Rostock, Germany
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Bibliography. Current world literature. Curr Opin Obstet Gynecol 2009; 21:296-300. [PMID: 19458522 DOI: 10.1097/gco.0b013e32832c972c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.
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Current literature in diabetes. Diabetes Metab Res Rev 2009; 25:i-x. [PMID: 19219862 DOI: 10.1002/dmrr.918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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