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Morrish F, Gingras H, Noonan J, Huang L, Sweet IR, Kuok IT, Knoblaugh SE, Hockenbery DM. Mitochondrial diabetes in mice expressing a dominant-negative allele of nuclear respiratory factor-1 (Nrf1) in pancreatic β-cells. Biochem Biophys Res Commun 2024; 737:150478. [PMID: 39128225 DOI: 10.1016/j.bbrc.2024.150478] [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: 05/03/2024] [Revised: 07/17/2024] [Accepted: 07/29/2024] [Indexed: 08/13/2024]
Abstract
Genetic polymorphisms in nuclear respiratory factor-1 (Nrf1), a key transcriptional regulator of nuclear-encoded mitochondrial proteins, have been linked to diabetes. Homozygous deletion of Nrf1 is embryonic lethal in mice. Our goal was to generate mice with β-cell-specific reduction in NRF1 function to investigate the relationship between NRF1 and diabetes. We report the generation of mice expressing a dominant-negative allele of Nrf1 (DNNRF1) in pancreatic β-cells. Heterozygous transgenic mice had high fed blood glucose levels detected at 3 wks of age, which persisted through adulthood. Plasma insulin levels in DNNRF1 transgenic mice were reduced, while insulin sensitivity remained intact in young animals. Islet size was reduced with increased numbers of apoptotic cells, and insulin content in islets by immunohistochemistry was low. Glucose-stimulated insulin secretion in isolated islets was reduced in DNNRF1-mice, but partially rescued by KCl, suggesting that decreased mitochondrial function contributed to the insulin secretory defect. Electron micrographs demonstrated abnormal mitochondrial morphology in β-cells. Expression of NRF1 target genes Tfam, Tfb1m and Tfb2m, and islet cytochrome c oxidase and succinate dehydrogenase activities were reduced in DNNRF1-mice. Rescue of mitochondrial function with low level activation of transgenic c-Myc in β-cells was sufficient to restore β-cell mass and prevent diabetes. This study demonstrates that reduced NRF1 function can lead to loss of β-cell function and establishes a model to study the interplay between regulators of bi-genomic gene transcription in diabetes.
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Affiliation(s)
- Fionnuala Morrish
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Helene Gingras
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Joanna Noonan
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Li Huang
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Ian R Sweet
- University of Washington Diabetes Institute, University of Washington, Seattle, WA, USA
| | - Iok Teng Kuok
- University of Washington Diabetes Institute, University of Washington, Seattle, WA, USA
| | - Sue E Knoblaugh
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - David M Hockenbery
- Division of Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, USA.
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2
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Wang J, Yan D, Cui H, Zhang R, Ma X, Chen L, Hu C, Wu J. Identification of eight genomic protective alleles for mitochondrial diabetes by Kinship-graph convolutional network. J Diabetes Investig 2024; 15:52-62. [PMID: 38157301 PMCID: PMC10759726 DOI: 10.1111/jdi.14125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 01/03/2024] Open
Abstract
AIMS Nearly 85% of maternally inherited diabetes and deafness (MIDD) are caused by the m.3243A>G mutation in the mitochondrial DNA. However, the clinical phenotypes of MIDD may also be influenced by the nuclear genome, this study aimed to investigate nuclear genome variants that influence clinical phenotypes associated with m.3243A>G mutation in MIDD based on whole-genome sequencing of the patients belonging to pedigrees. MATERIALS AND METHODS We analyzed a whole-genome sequencing (WGS) dataset from blood samples of 38 MIDD patients with the m.3243A > G mutation belonging to 10 pedigrees, by developing a Kinship-graph convolutional network approach, called Ki-GCN, integrated with the conventional genome-wide association study (GWAS) methods. RESULTS We identified eight protective alleles in the nuclear genome that have protective effects against the onset of MIDD, related deafness, and also type 2 diabetes. Based on these eight protective alleles, we constructed an effective logistic regression model to predict the early or late onset of MIDD patients. CONCLUSIONS There are protective alleles in the nuclear genome that are associated with the onset-age of MIDD patients and might also provide protective effects on the deafness derived from MIDD patients.
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Affiliation(s)
- Jiahao Wang
- CAS Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Dandan Yan
- Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Diabetes InstituteShanghai Jiao Tong University Affiliated Sixth People's HospitalShanghaiChina
| | - Haoyue Cui
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Rong Zhang
- Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Diabetes InstituteShanghai Jiao Tong University Affiliated Sixth People's HospitalShanghaiChina
| | - Xiaojing Ma
- Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Diabetes InstituteShanghai Jiao Tong University Affiliated Sixth People's HospitalShanghaiChina
| | - Luonan Chen
- CAS Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Key Laboratory of Systems Health Science of Zhejiang Province, Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouZhejiangChina
| | - Cheng Hu
- Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Centre for Diabetes, Shanghai Diabetes InstituteShanghai Jiao Tong University Affiliated Sixth People's HospitalShanghaiChina
- Institute for Metabolic DiseaseFengxian Central Hospital Affiliated to Southern Medical UniversityShanghaiChina
| | - Jiarui Wu
- CAS Key Laboratory of Systems Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Key Laboratory of Systems Health Science of Zhejiang Province, Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouZhejiangChina
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3
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Morrish F, Gingras H, Noonan J, Huang L, Sweet IR, Kuok IT, Knoblaugh SE, Hockenbery DM. Mitochondrial diabetes in mice expressing a dominant-negative allele of nuclear respiratory factor-1 ( Nrf1 ) in pancreatic β-cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.524153. [PMID: 38014068 PMCID: PMC10680558 DOI: 10.1101/2023.01.22.524153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Genetic polymorphisms in nuclear respiratory factor-1 ( NRF1 ), a key transcriptional regulator of nuclear-encoded mitochondrial proteins, have been linked to diabetes. Homozygous deletion of Nrf1 is embryonic lethal in mice. Our goal was to generate mice with β-cell-specific reduction in NRF1 function to investigate the relationship between NRF1 and diabetes. We report the generation of mice expressing a dominant-negative allele of Nrf1 (DNNRF1) in pancreatic β-cells. Heterozygous transgenic mice had high fed blood glucose levels detected at 3 wks of age, which persisted through adulthood. Plasma insulin levels in DNNRF1 transgenic mice were reduced, while insulin sensitivity remained intact in young animals. Islet size was reduced with increased numbers of apoptotic cells, and insulin content in islets by immunohistochemistry was low. Glucose-stimulated insulin secretion in isolated islets was reduced in DNNRF1-mice, but partially rescued by KCl, suggesting that decreased mitochondrial function contributed to the insulin secretory defect. Electron micrographs demonstrated abnormal mitochondrial morphology in β- cells. Expression of NRF1 target genes Tfam , T@1m and T@2m , and islet cytochrome c oxidase and succinate dehydrogenase activities were reduced in DNNRF1-mice. Rescue of mitochondrial function with low level activation of transgenic c-Myc in β-cells was sufficient to restore β-cell mass and prevent diabetes. This study demonstrates that reduced NRF1 function can lead to loss of β-cell function and establishes a model to study the interplay between regulators of bi- genomic gene transcription in diabetes.
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4
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Yu X, Arden C, Berlinguer-Palmini R, Chen C, Bradshaw C, Smith AL, Whitehall J, White M, Anderson S, Kattner N, Shaw J, Turnbull D, Greaves LC, Walker M. Mitochondrial complex I subunit deficiency promotes pancreatic α-cell proliferation. Mol Metab 2022; 60:101489. [PMID: 35390502 PMCID: PMC9046450 DOI: 10.1016/j.molmet.2022.101489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/28/2022] [Indexed: 10/29/2022] Open
Abstract
OBJECTIVE There is strong evidence that mitochondrial DNA mutations and mitochondrial dysfunction play a role in diabetes pathogenesis. The homozygous knock-in mtDNA mutator mouse is a model of premature aging due to the accumulation of mitochondrial DNA mutations. We used this mouse model to investigate the relationship between mitochondrial subunit expression and pancreatic islet cell composition. METHODS Quadruple immunofluorescence was used to quantify mitochondrial subunit expression (complex I and IV) and cell composition in pancreatic islets from mitochondrial DNA mutator mice (PolgAmut/mut) and control C57BL/6 mice at 12 and 44 weeks of age. RESULTS Mitochondrial complex I subunit expression was decreased in islets from 12 week PolgAmut/mut mice. This complex I deficiency persisted with age and was associated with decreased insulin staining intensity at 44 weeks. Complex I deficiency was greater in α-cells compared with β-cells in islets from 44 week PolgAmut/mut mice. Islet cell composition was normal in 12 week PolgAmut/mut mice, but the β: α cell ratio was decreased in islets from 44 week PolgAmut/mut mice. This was due to an increase in α-cell number linked to an increase in α-cell proliferation. CONCLUSION Complex I deficiency promotes α-cell proliferation and alters islet cell composition.
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Affiliation(s)
- Xuefei Yu
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Catherine Arden
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - Chun Chen
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Carla Bradshaw
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Anna Lm Smith
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Julia Whitehall
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Michael White
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Scott Anderson
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Nicole Kattner
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - James Shaw
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Doug Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Laura C Greaves
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK.
| | - Mark Walker
- Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.
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5
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Is Type 2 Diabetes a Primary Mitochondrial Disorder? Cells 2022; 11:cells11101617. [PMID: 35626654 PMCID: PMC9140179 DOI: 10.3390/cells11101617] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/27/2022] [Accepted: 04/20/2022] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus is the most common endocrine disturbance in inherited mitochondrial diseases. It is essential to increase awareness of the correct diagnosis and treatment of diabetes in these patients and screen for the condition in family members, as diabetes might appear with distinctive clinical features, complications and at different ages of onset. The severity of mitochondrial-related diabetes is likely to manifest on a large scale of phenotypes depending on the location of the mutation and whether the number of affected mitochondria copies (heteroplasmy) reaches a critical threshold. Regarding diabetes treatment, the first-choice treatment for type 2 diabetes (T2D), metformin, is not recommended because of the risk of lactic acidosis. The preferred treatment for diabetes in patients with mitochondrial disorders is SGLT-2i and mitochondrial GLP-1-related substances. The tight relationship between mitochondrial dysfunction, reduced glucose-stimulated insulin secretion (GSIS), and diabetes development in human patients is acknowledged. However, despite the well-characterized role of mitochondria in GSIS, there is a relative lack of data in humans implicating mitochondrial dysfunction as a primary defect in T2D. Our recent studies have provided data supporting the significant role of the mitochondrial respiratory-chain enzyme, cytochrome c oxidase (COX), in regulating GSIS in a rodent model of T2D, the Cohen diabetic sensitive (CDs) rat. The nutritionally induced diabetic CDs rat demonstrates several features of mitochondrial diseases: markedly reduced COX activity in several tissues, increased reactive oxygen production, decreased ATP generation, and increased lactate dehydrogenase expression in islets. Moreover, our data demonstrate that reduced islet-COX activity precedes the onset of diabetes, suggesting that islet-COX deficiency is the primary defect causing diabetes in this model. This review examines the possibility of including T2D as a primary mitochondrial-related disease. Understanding the critical interdependence between diabetes and mitochondrial dysfunction, centering on the role of COX, may open novel avenues to diagnose and treat diabetes in patients with mitochondrial diseases and mitochondrial dysfunction in diabetic patients.
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Ng YS, Lim AZ, Panagiotou G, Turnbull DM, Walker M. Endocrine Manifestations and New Developments in Mitochondrial Disease. Endocr Rev 2022; 43:583-609. [PMID: 35552684 PMCID: PMC9113134 DOI: 10.1210/endrev/bnab036] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Indexed: 11/19/2022]
Abstract
Mitochondrial diseases are a group of common inherited diseases causing disruption of oxidative phosphorylation. Some patients with mitochondrial disease have endocrine manifestations, with diabetes mellitus being predominant but also include hypogonadism, hypoadrenalism, and hypoparathyroidism. There have been major developments in mitochondrial disease over the past decade that have major implications for all patients. The collection of large cohorts of patients has better defined the phenotype of mitochondrial diseases and the majority of patients with endocrine abnormalities have involvement of several other systems. This means that patients with mitochondrial disease and endocrine manifestations need specialist follow-up because some of the other manifestations, such as stroke-like episodes and cardiomyopathy, are potentially life threatening. Also, the development and follow-up of large cohorts of patients means that there are clinical guidelines for the management of patients with mitochondrial disease. There is also considerable research activity to identify novel therapies for the treatment of mitochondrial disease. The revolution in genetics, with the introduction of next-generation sequencing, has made genetic testing more available and establishing a precise genetic diagnosis is important because it will affect the risk for involvement for different organ systems. Establishing a genetic diagnosis is also crucial because important reproductive options have been developed that will prevent the transmission of mitochondrial disease because of mitochondrial DNA variants to the next generation.
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Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Albert Zishen Lim
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Grigorios Panagiotou
- Department of Diabetes and Endocrinology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Mark Walker
- Department of Diabetes and Endocrinology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
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7
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Aharon-Hananel G, Romero-Afrima L, Saada A, Mantzur C, Raz I, Weksler-Zangen S. Cytochrome c Oxidase Activity as a Metabolic Regulator in Pancreatic Beta-Cells. Cells 2022; 11:cells11060929. [PMID: 35326380 PMCID: PMC8946064 DOI: 10.3390/cells11060929] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cells couple glucose-stimulated insulin secretion (GSIS) with oxidative phosphorylation via cytochrome c oxidase (COX), a mitochondrial respiratory-chain enzyme. The Cohen diabetic-sensitive (CDs) rats exhibit hyperglycemia when fed a diabetogenic diet but maintain normoglycemia on a regular diet. We have previously reported a decreased COX activity in CDs rats and explored its relevance for type 2 diabetes (T2D). In this study, we investigated the relation between COX activity in islets, peripheral-blood mononuclear cells (PBMCs), and GSIS during diabetes development in CDs rats fed a diabetogenic diet for 4, 11, 20, and 30 days and during reversion to normoglycemia in hyperglycemic CDs rats fed a reversion diet for 7, 11, and 20 days. An oral glucose-tolerance test was performed at different periods of the diets measuring blood glucose and insulin concentrations. COX activity was determined in islets and PBMCs isolated from rats at the different periods of the diets. We demonstrated a progressive reduction in COX activity in CDs-islets that correlated positively with the decreasing GSIS (R2 = 0.9691, p < 0.001) and inversely with the elevation in blood glucose levels (R2 = 0.8396, p < 0.001). Hyperglycemia was initiated when islet COX activity decreased below 46%. The reversion diet restored >46% of the islet COX activity and GSIS while re-establishing normoglycemia. Interestingly, COX activity in PBMCs correlated significantly with islet COX activity (R2 = 0.8944, p < 0.001). Our data support islet COX activity as a major metabolic regulator of β-cells function. The correlation between COX activity in PBMCs and islets may serve as a noninvasive biomarker to monitor β-cell dysfunction in diabetes.
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Affiliation(s)
- Genya Aharon-Hananel
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Division of Endocrinology, Diabetes and Metabolism, The Chaim Sheba Medical Center, Tel Hashomer, Ramat-Gan 5266202, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Leonor Romero-Afrima
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Ann Saada
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Carmit Mantzur
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
| | - Itamar Raz
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Sarah Weksler-Zangen
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
- The Liver Research Laboratory, Hadassah Medical Center, Jerusalem 9112102, Israel
- Correspondence: ; Tel.: +972-50-5172008
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Paul A, Azhar S, Das PN, Bairagi N, Chatterjee S. Elucidating the metabolic characteristics of pancreatic β-cells from patients with type 2 diabetes (T2D) using a genome-scale metabolic modeling. Comput Biol Med 2022; 144:105365. [PMID: 35276551 DOI: 10.1016/j.compbiomed.2022.105365] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/24/2022] [Accepted: 02/27/2022] [Indexed: 11/27/2022]
Abstract
Diabetes is a global health problem caused primarily by the inability of pancreatic β-cells to secrete adequate insulin. Despite extensive research, the identity of factors contributing to the dysregulated metabolism-secretion coupling in the β-cells remains elusive. The present study attempts to capture some of these factors responsible for the impaired β-cell metabolism-secretion coupling that contributes to diabetes pathogenesis. The metabolic-flux profiles of pancreatic β-cells were predicted using genome-scale metabolic modeling for ten diabetic patients and ten control subjects. Analysis of these flux states shows reduction in the mitochondrial fatty acid oxidation and mitochondrial oxidative phosphorylation pathways, that leads to decreased insulin secretion in diabetes. We also observed elevated reactive oxygen species (ROS) generation through peroxisomal fatty acid β-oxidation. In addition, cellular antioxidant defense systems were found to be attenuated in diabetes. Our analysis also uncovered the possible changes in the plasma metabolites in diabetes due to the β-cells failure. These efforts subsequently led to the identification of seven metabolites associated with cardiovascular disease (CVD) pathogenesis, thus establishing its link as a secondary complication of diabetes.
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Affiliation(s)
- Abhijit Paul
- Complex Analysis Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA, 94304, USA; Division of Endocrinology, Gerontology and Metabolism, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94304, USA
| | - Phonindra Nath Das
- Department of Mathematics, Ramakrishna Mission Vivekananda Centenary College, Rahara, Kolkata, 700118, India
| | - Nandadulal Bairagi
- Centre for Mathematical Biology and Ecology, Department of Mathematics, Jadavpur University, Kolkata, 700032, India
| | - Samrat Chatterjee
- Complex Analysis Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India.
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9
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Norose T, Ito Y, Ohike N. Two autopsy cases of mitochondrial disease (MELAS and MERRF) with special reference to the histological and immunohistochemical findings of the pancreatic islets. Pathol Int 2020; 70:915-917. [PMID: 32808720 DOI: 10.1111/pin.13008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/26/2020] [Accepted: 08/05/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Tomoko Norose
- Department of Pathology and Laboratory Medicine, Showa University Fujigaoka Hospital, Kanagawa, Japan
| | - Yoshinori Ito
- Department of Neurology, Yokufukai Geriatric Hospital, Tokyo, Japan
| | - Nobuyuki Ohike
- Department of Pathology and Laboratory Medicine, Showa University Fujigaoka Hospital, Kanagawa, Japan
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10
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2019; 2:14. [PMID: 31754635 PMCID: PMC6854877 DOI: 10.12688/wellcomeopenres.10535.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 01/07/2023] Open
Abstract
Background: Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods: By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results: Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions: Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function.
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Affiliation(s)
- Karl J Morten
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Michelle Potter
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Luned Badder
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Pamela Sivathondan
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Rebecca Dragovic
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Abigale Neumann
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - James Gavin
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Roshan Shrestha
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Svetlana Reilly
- Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
| | - Kanchan Phadwal
- BRC Translational Immunology Lab, NIHR, Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Tiffany A Lodge
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Angela Borzychowski
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Sharon Cookson
- Institute of Cellular Medicine, Haematological Sciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Corey Mitchell
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | | | | | - Johanna Uusimaa
- Department of Paediatrics, University of Oulu, Oulu, Finland
| | - James Hynes
- Luxcel BioSciences Ltd, BioInnovation Centre, University College Cork, Cork, Ireland
| | - Joanna Poulton
- Nuffield Department of Obstetrics & Gynaecology, The Women's Centre, University of Oxford, John Radcliffe Hospital, Oxford, UK
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11
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2017; 2:14. [DOI: 10.12688/wellcomeopenres.10535.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods: By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results: Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions: Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function.
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, Poulton J. Insights into pancreatic β cell energy metabolism using rodent β cell models. Wellcome Open Res 2017; 2:14. [DOI: 10.12688/wellcomeopenres.10535.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2017] [Indexed: 11/20/2022] Open
Abstract
Background:Mitochondrial diabetes is primarily caused by β-cell failure, but there are gaps in our understanding of pathogenesis.Methods:By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function.Results:Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy.Conclusions:Insulinoma cell lines provide a useful model of mechanisms affecting β-cell mitochondrial function or studying mitochondrial associated drug toxicity.
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Abstract
OBJECTIVE Inherited metabolic diseases (IMDs) can affect many organ systems, including the endocrine system. There are limited data regarding endocrine dysfunctions related to IMDs in adults, however, no data exist in pediatric patients with IMDs. The aim of this study was to investigate endocrine dysfunctions in patients with IMDs by assessing their demographic, clinical, and laboratory data. METHODS Data were obtained retrospectively from the medical reports of patients with IMDs who were followed by the division of pediatric metabolism and nutrition between June 2011 and November 2013. RESULTS In total, 260 patients [139 males (53%) and 121 females (47%)] with an IMD diagnosis were included in the study. The mean age of the patients was 5.94 (range; 0.08 to 49) years and 95.8% (249 of 260 patients) were in the pediatric age group. Growth status was evaluated in 258 patients and of them, 27 (10.5%) had growth failure, all cases of which were attributed to non-endocrine reasons. There was a significant correlation between growth failure and serum albumin levels below 3.5 g/dL (p=0.002). Only three of 260 (1.1%) patients had endocrine dysfunction. Of these, one with lecithin-cholesterol acyltransferase deficiency and another with Kearns-Sayre syndrome had diabetes, and one with glycerol kinase deficiency had glucocorticoid deficiency. CONCLUSION Endocrine dysfunction in patients with IMDs is relatively rare. For this reason, there is no need to conduct routine endocrine evaluations in most patients with IMDs unless a careful and detailed history and a physical examination point to an endocrine dysfunction.
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Affiliation(s)
- Şahin Erdöl
- Uludağ University Faculty of Medicine, Department of Pediatrics, Division of Metabolism, Bursa, Turkey
| | - Halil Sağlam
- Uludağ University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Metabolism and Endocrinology, Bursa, Turkey, E-mail:
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14
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Liu Z, Jeppesen PB, Gregersen S, Bach Larsen L, Hermansen K. Chronic Exposure to Proline Causes Aminoacidotoxicity and Impaired Beta-Cell Function: Studies In Vitro. Rev Diabet Stud 2016; 13:66-78. [PMID: 27563695 DOI: 10.1900/rds.2016.13.66] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Pancreatic islet-cell dysfunction is a hallmark in the development of diabetes, but the reasons for the primary β-cell defect are still elusive. Elevated circulating proline levels have been found in subjects with insulin resistance, obesity, and type 2 diabetes. Therefore, we assessed β-cell function, gene expressions, and cell death after long-term exposure of pancreatic β-cells to excess proline in vitro. METHODS Isolated mouse islets and INS-1E cells were incubated with and without excess proline. After 72 h, we examined: (1) β-cell function, including basal insulin secretion (BIS) and glucose-stimulated insulin secretion (GSIS), (2) transcription factors related to insulin gene expression and enzymes involved in the tricarboxylic acid cycle and cholesterol biogenesis, (3) cellular triglycerides (TG) and cholesterol content, (4) the death of INS-1E cells and 3H thymidine incorporation, and (5) protein expression of INS-1E cells in response to proline by proteomics. RESULTS We found that high doses of proline increased BIS and decreased GSIS in both isolated mouse islets and INS-1E cells. MafA, insulin 1, and the cytochrome c oxidase subunit VIa polypeptide 2 mRNA expressions were all downregulated, indicating that proline impaired insulin gene transcription and mitochondrial oxidative phosphorylation. In contrast, mevalonate decarboxylase gene expression was upregulated, and simultaneously, cholesterol content in INS-1E cells was enhanced. Protein profiling of INS-1E cells revealed that cytosolic non-specific dipeptidase and α enolase were differentially expressed. CONCLUSIONS Our results indicate that proline-induced insulin transcription and mitochondrial oxidative phosphorylation impairment may contribute to the β-cell dysfunction observed in type 2 diabetes. Caution should be applied in interpreting the pathophysiological role of proline since very high proline concentrations were used in the experiments.
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Affiliation(s)
- Zhenping Liu
- Department of Medicine and Endocrinology, Aarhus University Hospital, Tage-Hansens Gade 2, DK-8000 Aarhus C, Denmark
| | - Per B Jeppesen
- Department of Medicine and Endocrinology, Aarhus University Hospital, Tage-Hansens Gade 2, DK-8000 Aarhus C, Denmark
| | - Søren Gregersen
- Department of Medicine and Endocrinology, Aarhus University Hospital, Tage-Hansens Gade 2, DK-8000 Aarhus C, Denmark
| | - Lotte Bach Larsen
- Department of Food Science, Faculty of Agricultural Sciences, Aarhus University, DK-8230 Tjele, Denmark
| | - Kjeld Hermansen
- Department of Medicine and Endocrinology, Aarhus University Hospital, Tage-Hansens Gade 2, DK-8000 Aarhus C, Denmark
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15
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Renner S, Dobenecker B, Blutke A, Zöls S, Wanke R, Ritzmann M, Wolf E. Comparative aspects of rodent and nonrodent animal models for mechanistic and translational diabetes research. Theriogenology 2016; 86:406-21. [PMID: 27180329 DOI: 10.1016/j.theriogenology.2016.04.055] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/22/2016] [Accepted: 03/14/2016] [Indexed: 12/31/2022]
Abstract
The prevalence of diabetes mellitus, which currently affects 387 million people worldwide, is permanently rising in both adults and adolescents. Despite numerous treatment options, diabetes mellitus is a progressive disease with severe comorbidities, such as nephropathy, neuropathy, and retinopathy, as well as cardiovascular disease. Therefore, animal models predictive of the efficacy and safety of novel compounds in humans are of great value to address the unmet need for improved therapeutics. Although rodent models provide important mechanistic insights, their predictive value for therapeutic outcomes in humans is limited. In recent years, the pig has gained importance for biomedical research because of its close similarity to human anatomy, physiology, size, and, in contrast to non-human primates, better ethical acceptance. In this review, anatomic, biochemical, physiological, and morphologic aspects relevant to diabetes research will be compared between different animal species, that is, mouse, rat, rabbit, pig, and non-human primates. The value of the pig as a model organism for diabetes research will be highlighted, and (dis)advantages of the currently available approaches for the generation of pig models exhibiting characteristics of metabolic syndrome or type 2 diabetes mellitus will be discussed.
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Affiliation(s)
- Simone Renner
- Gene Center and Center for Innovative Medical Models (CiMM), Ludwig-Maximilians-Universität München, Munich, Germany; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany.
| | - Britta Dobenecker
- Chair of Animal Nutrition and Dietetics, Department of Veterinary Science, LMU Munich, Munich, Germany
| | - Andreas Blutke
- Institute of Veterinary Pathology, Center for Clinical Veterinary Medicine, LMU Munich, Germany
| | - Susanne Zöls
- Clinic for Swine, Center for Clinical Veterinary Medicine, LMU Munich, Germany
| | - Rüdiger Wanke
- Institute of Veterinary Pathology, Center for Clinical Veterinary Medicine, LMU Munich, Germany
| | - Mathias Ritzmann
- Clinic for Swine, Center for Clinical Veterinary Medicine, LMU Munich, Germany
| | - Eckhard Wolf
- Gene Center and Center for Innovative Medical Models (CiMM), Ludwig-Maximilians-Universität München, Munich, Germany; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany
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16
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Edalat A, Schulte-Mecklenbeck P, Bauer C, Undank S, Krippeit-Drews P, Drews G, Düfer M. Mitochondrial succinate dehydrogenase is involved in stimulus-secretion coupling and endogenous ROS formation in murine beta cells. Diabetologia 2015; 58:1532-41. [PMID: 25874444 DOI: 10.1007/s00125-015-3577-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 03/13/2015] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Generation of reduction equivalents is a prerequisite for nutrient-stimulated insulin secretion. Mitochondrial succinate dehydrogenase (SDH) fulfils a dual function with respect to mitochondrial energy supply: (1) the enzyme is part of mitochondrial respiratory chains; and (2) it catalyses oxidation of succinate to fumarate in the Krebs cycle. The aim of our study was to elucidate the significance of SDH for beta cell stimulus-secretion coupling (SSC). METHODS Mitochondrial variables, reactive oxygen species (ROS) and cytosolic Ca(2+) concentration ([Ca(2+)]c) were measured by fluorescence techniques and insulin release by radioimmunoassay in islets or islet cells of C57Bl/6N mice. RESULTS Inhibition of SDH with 3-nitropropionic acid (3-NPA) or monoethyl fumarate (MEF) reduced glucose-stimulated insulin secretion. Inhibition of the ATP-sensitive K(+) channel (KATP channel) partly prevented this effect, whereas potentiation of antioxidant defence by superoxide dismutase mimetics (TEMPOL and mito-TEMPO) or by nuclear factor erythroid 2-related factor 2 (Nrf-2)-mediated upregulation of antioxidant enzymes (oltipraz, tert-butylhydroxyquinone) did not diminish the inhibitory influence of 3-NPA. Blocking SDH decreased glucose-stimulated increase in intracellular FADH2 concentration without alterations in NAD(P)H. In addition, 3-NPA and MEF drastically reduced glucose-induced hyperpolarisation of mitochondrial membrane potential, indicative of decreased ATP production. As a consequence, the glucose-stimulated rise in [Ca(2+)]c was significantly delayed and reduced. Acute application of 3-NPA interrupted glucose-driven oscillations of [Ca(2+)]c. 3-NPA per se did not elevate intracellular ROS, but instead prevented glucose-induced ROS accumulation. CONCLUSIONS/INTERPRETATION SDH is an important regulator of insulin secretion and ROS production. Inhibition of SDH interrupts membrane-potential-dependent SSC, pointing to a pivotal role of mitochondrial FAD/FADH2 homeostasis for the maintenance of glycaemic control.
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Affiliation(s)
- Armin Edalat
- Department of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstraße 48, 48149, Münster, Germany
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17
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Kim YK, Joung KH, Ryu MJ, Kim SJ, Kim H, Chung HK, Lee MH, Lee SE, Choi MJ, Chang JY, Hong HJ, Kim KS, Lee SH, Kweon GR, Kim H, Lee CH, Kim HJ, Shong M. Disruption of CR6-interacting factor-1 (CRIF1) in mouse islet beta cells leads to mitochondrial diabetes with progressive beta cell failure. Diabetologia 2015; 58:771-80. [PMID: 25660120 DOI: 10.1007/s00125-015-3506-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/30/2014] [Indexed: 12/25/2022]
Abstract
AIM/HYPOTHESIS Although mitochondrial oxidative phosphorylation (OxPhos) dysfunction is believed to be responsible for beta cell dysfunction in insulin resistance and mitochondrial diabetes, the mechanisms underlying progressive beta cell failure caused by defective mitochondrial OxPhos are largely unknown. METHODS We examined the in vivo phenotypes of beta cell dysfunction in beta cell-specific Crif1 (also known as Gadd45gip1)-deficient mice. CR6-interacting factor-1 (CRIF1) is a mitochondrial protein essential for the synthesis and formation of the OxPhos complex in the inner mitochondrial membrane. RESULTS Crif1(beta-/-) mice exhibited impaired glucose tolerance with defective insulin secretion as early as 4 weeks of age without defects in islet structure. At 11 weeks of age, Crif1(beta-/-) mice displayed characteristic ultrastructural mitochondrial abnormalities as well as severe glucose intolerance. Furthermore, islet area and insulin content was decreased by approximately 50% compared with wild-type mice. Treatment with the glucoregulatory drug exenatide, a glucagon-like peptide-1 (GLP-1) agonist, was not sufficient to preserve beta cell function in Crif1(beta-/-) mice. CONCLUSIONS/INTERPRETATION Our results indicate that mitochondrial OxPhos dysfunction triggers progressive beta cell failure that is not halted by treatment with a GLP-1 agonist. The Crif1(beta-/-) mouse is a useful model for the study of beta cell failure caused by mitochondrial OxPhos dysfunction.
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Affiliation(s)
- Yong Kyung Kim
- Research Center for Endocrine and Metabolic Diseases, Chungnam National University School of Medicine, Daejeon, 301-721, Korea
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18
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Karaa A, Goldstein A. The spectrum of clinical presentation, diagnosis, and management of mitochondrial forms of diabetes. Pediatr Diabetes 2015; 16:1-9. [PMID: 25330715 DOI: 10.1111/pedi.12223] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/03/2014] [Accepted: 09/09/2014] [Indexed: 01/21/2023] Open
Abstract
Primary mitochondrial diseases refer to a group of heterogeneous and complex genetic disorders affecting 1:5000 people. The true prevalence is anticipated to be even higher because of the complexity of achieving a diagnosis in many patients who present with multisystemic complaints ranging from infancy to adulthood. Diabetes is a prominent feature of several of these disorders which might be overlooked by the endocrinologist. We here review mitochondrial disorders and describe the phenotypic and pathogenetic differences between mitochondrial diabetes mellitus (mDM) and other more common forms of diabetes mellitus.
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Affiliation(s)
- Amel Karaa
- Neurogenetics Clinic, Neurology and Clinical Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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19
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Fujita Y, Kozawa J, Iwahashi H, Yoneda S, Uno S, Yoshikawa A, Okita K, Eguchi H, Nagano H, Imagawa A, Shimomura I. Increment of serum C-peptide measured by glucagon test closely correlates with human relative beta-cell area. Endocr J 2015; 62:329-37. [PMID: 25740613 DOI: 10.1507/endocrj.ej14-0456] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Pancreatic beta-cell mass contributes to glucose tolerance. The aim of this study was to evaluate the relationships between human beta-cell mass and various clinical parameters, including insulin secretory capacity. The study included 32 Japanese patients who underwent pancreatectomy and were naive to oral hypoglycemic agents and insulin. They were classified into those with normal glucose tolerance (n=13), impaired glucose tolerance (n=9) and diabetes (n=10), and their insulin secretory capacity and insulin resistance were evaluated. Immunohistochemistry was used to determine relative beta-cell area (%) which represented the proportion of insulin-positive cell area to whole pancreatic section. Increment of C-peptide immunoreactivity level by glucagon test (ΔC-peptide, increment of serum C-peptide [nmol/L] at 6 min after intravenous injection of 1-mg glucagon; r=0.64, p=0.002), homeostasis model assessment of beta-cell function (HOMA-beta, fasting immunoreactive insulin [μIU/mL] x 20 / (fasting plasma glucose [mmol/L] - 3.5); r=0.50, p=0.003), C-peptide index (CPI, fasting C-peptide [nmol/L] / fasting plasma glucose [mmol/L]; r=0.36, p=0.042), and fasting immunoreactive insulin (F-IRI [pmol/L]; r=0.36, p=0.044) correlated significantly and positively with the relative beta-cell area. The area under the curve of plasma glucose level from 0 to 120 min by 75 g-OGTT (AUC0-120) also correlated significantly and inversely with the relative beta-cell area (r=-0.36, p=0.045). Stepwise multiple regression analysis identified ΔC-peptide as the only independent and significant determinant of the relative beta-cell area. We conclude that ΔC-peptide, HOMA-beta, CPI, F-IRI and AUC0-120 correlated closely with the relative beta-cell area, and ΔC-peptide was the most valuable index for the prediction of the area.
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Affiliation(s)
- Yukari Fujita
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita 565-0871, Japan
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20
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Mory PB, Santos MCD, Kater CE, Moisés RS. Maternally-inherited diabetes with deafness (MIDD) and hyporeninemic hypoaldosteronism. ACTA ACUST UNITED AC 2013; 56:574-7. [PMID: 23295301 DOI: 10.1590/s0004-27302012000800019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 10/26/2012] [Indexed: 12/20/2022]
Abstract
Maternally-inherited diabetes with deafness (MIDD) is a rare form of monogenic diabetes that results, in most cases, from an A-to-G transition at position 3243 of mitochondrial DNA (m.3243A>G) in the mitochondrial-encoded tRNA leucine (UUA/G) gene. As the name suggests, this condition is characterized by maternally-inherited diabetes and bilateral neurosensory hearing impairment. A characteristic of mitochondrial cytopathies is the progressive multisystemic involvement with the development of more symptoms during the course of the disease. We report here the case of a patient with MIDD who developed hyporeninemic hypoaldosteronism.
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Affiliation(s)
- Patricia B Mory
- Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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21
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Schaefer AM, Walker M, Turnbull DM, Taylor RW. Endocrine disorders in mitochondrial disease. Mol Cell Endocrinol 2013; 379:2-11. [PMID: 23769710 PMCID: PMC3820028 DOI: 10.1016/j.mce.2013.06.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 04/30/2013] [Accepted: 06/06/2013] [Indexed: 02/09/2023]
Abstract
Endocrine dysfunction in mitochondrial disease is commonplace, but predominantly restricted to disease of the endocrine pancreas resulting in diabetes mellitus. Other endocrine manifestations occur, but are relatively rare by comparison. In mitochondrial disease, neuromuscular symptoms often dominate the clinical phenotype, but it is of paramount importance to appreciate the multi-system nature of the disease, of which endocrine dysfunction may be a part. The numerous phenotypes attributable to pathogenic mutations in both the mitochondrial (mtDNA) and nuclear DNA creates a complex and heterogeneous catalogue of disease which can be difficult to navigate for novices and experts alike. In this article we provide an overview of the endocrine disorders associated with mitochondrial disease, the way in which the underlying mitochondrial disorder influences the clinical presentation, and how these factors influence subsequent management.
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Affiliation(s)
- Andrew M. Schaefer
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
- Corresponding authors. Address: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. Tel.: +44 1912223685.
| | - Mark Walker
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Douglass M. Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Robert W. Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
- Corresponding authors. Address: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. Tel.: +44 1912223685.
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Wiederkehr A, Wollheim CB. Mitochondrial signals drive insulin secretion in the pancreatic β-cell. Mol Cell Endocrinol 2012; 353:128-37. [PMID: 21784130 DOI: 10.1016/j.mce.2011.07.016] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 07/07/2011] [Indexed: 12/31/2022]
Abstract
β-Cell nutrient sensing depends on mitochondrial function. Oxidation of nutrient-derived metabolites in the mitochondria leads to plasma membrane depolarization, Ca(2+) influx and insulin granule exocytosis. Subsequent mitochondrial Ca(2+) uptake further accelerates metabolism and oxidative phosphorylation. Nutrient activation also increases the mitochondrial matrix pH. This alkalinization is required to maintain elevated insulin secretion during prolonged nutrient stimulation. Together the mitochondrial Ca(2+) rise and matrix alkalinization assure optimal ATP synthesis necessary for efficient activation of the triggering pathway of insulin secretion. The sustained, amplifying pathway of insulin release also depends on mitochondrial Ca(2+) signals, which likely influence the generation of glucose-derived metabolites serving as coupling factors. Therefore, mitochondria are both recipients and generators of signals essential for metabolism-secretion coupling. Activation of these signaling pathways would be an attractive target for the improvement of β-cell function and the treatment of type 2 diabetes.
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Vantyghem MC, Dobbelaere D, Mention K, Wemeau JL, Saudubray JM, Douillard C. Endocrine manifestations related to inherited metabolic diseases in adults. Orphanet J Rare Dis 2012; 7:11. [PMID: 22284844 PMCID: PMC3349544 DOI: 10.1186/1750-1172-7-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 01/28/2012] [Indexed: 02/07/2023] Open
Abstract
Most inborn errors of metabolism (IEM) are recessive, genetically transmitted diseases and are classified into 3 main groups according to their mechanisms: cellular intoxication, energy deficiency, and defects of complex molecules. They can be associated with endocrine manifestations, which may be complications from a previously diagnosed IEM of childhood onset. More rarely, endocrinopathies can signal an IEM in adulthood, which should be suspected when an endocrine disorder is associated with multisystemic involvement (neurological, muscular, hepatic features, etc.). IEM can affect all glands, but diabetes mellitus, thyroid dysfunction and hypogonadism are the most frequent disorders. A single IEM can present with multiple endocrine dysfunctions, especially those involving energy deficiency (respiratory chain defects), and metal (hemochromatosis) and storage disorders (cystinosis). Non-autoimmune diabetes mellitus, thyroid dysfunction and/or goiter and sometimes hypoparathyroidism should steer the diagnosis towards a respiratory chain defect. Hypogonadotropic hypogonadism is frequent in haemochromatosis (often associated with diabetes), whereas primary hypogonadism is reported in Alström disease and cystinosis (both associated with diabetes, the latter also with thyroid dysfunction) and galactosemia. Hypogonadism is also frequent in X-linked adrenoleukodystrophy (with adrenal failure), congenital disorders of glycosylation, and Fabry and glycogen storage diseases (along with thyroid dysfunction in the first 3 and diabetes in the last). This is a new and growing field and is not yet very well recognized in adulthood despite its consequences on growth, bone metabolism and fertility. For this reason, physicians managing adult patients should be aware of these diagnoses.
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Affiliation(s)
- Marie-Christine Vantyghem
- Service d'Endocrinologie et Maladies Métaboliques, 1, Rue Polonovski, Hôpital C Huriez, Centre Hospitalier Régional et Universitaire de Lille, 59037 Lille cedex, France.
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24
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Gardner DSL, Tai ES. Clinical features and treatment of maturity onset diabetes of the young (MODY). Diabetes Metab Syndr Obes 2012; 5:101-8. [PMID: 22654519 PMCID: PMC3363133 DOI: 10.2147/dmso.s23353] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Maturity onset diabetes of the young (MODY) is a heterogeneous group of disorders that result in β-cell dysfunction. It is rare, accounting for just 1%-2% of all diabetes. It is often misdiagnosed as type 1 or type 2 diabetes, as it is often difficult to distinguish MODY from these two forms. However, diagnosis allows appropriate individualized care, depending on the genetic etiology, and allows prognostication in family members. In this review, we discuss features of the common causes of MODY, as well as the treatment and diagnosis of MODY.
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Affiliation(s)
- Daphne SL Gardner
- Department of Endocrinology, Singapore General Hospital, Singapore
- Correspondence: Daphne SL Gardner, Department of Endocrinology, Singapore General Hospital, Block 6, Level 6, Outram Road, Singapore 169608, Tel +65 6321 4523, Email
| | - E Shyong Tai
- Department of Endocrinology, National University Hospital, Singapore
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25
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Bannwarth S, Abbassi M, Valéro R, Fragaki K, Dubois N, Vialettes B, Paquis-Flucklinger V. A novel unstable mutation in mitochondrial DNA responsible for maternally inherited diabetes and deafness. Diabetes Care 2011; 34:2591-3. [PMID: 21994425 PMCID: PMC3220838 DOI: 10.2337/dc11-1012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The m.3243A>G mutation in mitochondrial DNA (mtDNA) is responsible for maternally inherited diabetes and deafness (MIDD). Other mtDNA mutations are extremely rare. RESEARCH DESIGN AND METHODS We studied a patient presenting with diabetes and deafness who does not carry the m.3243A>G mutation. RESULTS We identified a deficiency of respiratory chain complex I in the patient's fibroblasts. mtDNA sequencing revealed a novel mutation that corresponds to an insertion of one or two cytosine residues in the coding region of the MT-ND6 gene (m.14535_14536insC or CC), leading to premature stop codons. This heteroplasmic mutation is unstable in the patient's somatic tissues. CONCLUSIONS We describe for the first time an unstable mutation in a mitochondrial gene coding for a complex I subunit, which is responsible for the MIDD phenotype. This mutation is likely favored by the m.14530T>C polymorphism, which is homoplasmic and leads to the formation of an 8-bp polyC tract responsible for genetic instability.
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Affiliation(s)
- Sylvie Bannwarth
- Department of Medical Genetics, Archet 2 Hospital, Centre Hospitalier Universitaire de Nice, Nice, France
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26
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Lu H, Koshkin V, Allister EM, Gyulkhandanyan AV, Wheeler MB. Molecular and metabolic evidence for mitochondrial defects associated with beta-cell dysfunction in a mouse model of type 2 diabetes. Diabetes 2010; 59:448-59. [PMID: 19903739 PMCID: PMC2809957 DOI: 10.2337/db09-0129] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The inability of pancreatic beta-cells to appropriately respond to glucose and secrete insulin are primary defects associated with beta-cell failure in type 2 diabetes. Mitochondrial dysfunction has been implicated as a key factor in the development of type 2 diabetes; however, a link between mitochondrial dysfunction and defective insulin secretion is unclear. RESEARCH DESIGN AND METHODS We investigated the changes in islet mitochondrial function and morphology during progression from insulin resistance (3 weeks old), immediately before hyperglycemia (5 weeks old), and after diabetes onset (10 weeks old) in transgenic MKR mice compared with controls. The molecular and protein changes at 10 weeks were determined using microarray and iTRAQ proteomic screens. RESULTS At 3 weeks, MKR mice were hyperinsulinemic but normoglycemic and beta-cells showed negligible mitochondrial or morphological changes. At 5 weeks, MKR islets displayed abrogated hyperpolarization of mitochondrial membrane potential (DeltaPsi(m)), reduced mitochondrial Ca(2+) uptake, slightly enlarged mitochondria, and reduced glucose-stimulated insulin secretion. By 10 weeks, MKR mice were hyperglycemic and hyperinsulinemic and beta-cells contained swollen mitochondria with disordered cristae. beta-Cells displayed impaired stimulus-secretion coupling including reduced hyperpolarization of DeltaPsi(m), impaired Ca(2+)-signaling, and reduced glucose-stimulated ATP/ADP and insulin release. Furthermore, decreased cytochrome c oxidase-dependent oxygen consumption and signs of oxidative stress were observed in diabetic islets. Protein profiling of diabetic islets revealed that 36 mitochondrial proteins were differentially expressed, including inner membrane proteins of the electron transport chain. CONCLUSIONS We provide novel evidence for a critical role of defective mitochondrial oxidative phosphorylation and morphology in the pathology of insulin resistance-induced beta-cell failure.
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Affiliation(s)
- Hongfang Lu
- From the Departments of Physiology and Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Vasilij Koshkin
- From the Departments of Physiology and Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Emma M. Allister
- From the Departments of Physiology and Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Armen V. Gyulkhandanyan
- From the Departments of Physiology and Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Michael B. Wheeler
- From the Departments of Physiology and Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
- Corresponding author: Michael B. Wheeler,
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Laloi-Michelin M, Meas T, Ambonville C, Bellanné-Chantelot C, Beaufils S, Massin P, Vialettes B, Gin H, Timsit J, Bauduceau B, Bernard L, Bertin E, Blickle JF, Cahen-Varsaux J, Cailleba A, Casanova S, Cathebras P, Charpentier G, Chedin P, Crea T, Delemer B, Dubois-Laforgue D, Duchemin F, Ducluzeau PH, Bouhanick B, Dusselier L, Gabreau T, Grimaldi A, Guerci B, Jacquin V, Kaloustian E, Larger E, Lecleire-Collet A, Lorenzini F, Louis J, Mausset J, Murat A, Nadler-Fluteau S, Olivier F, Paquis-Flucklinger V, Paris-Bockel D, Raynaud I, Reznik Y, Riveline JP, Schneebeli S, Sonnet E, Sola-Gazagnes A, Thomas JL, Trabulsi B, Virally M, Guillausseau PJ. The clinical variability of maternally inherited diabetes and deafness is associated with the degree of heteroplasmy in blood leukocytes. J Clin Endocrinol Metab 2009; 94:3025-30. [PMID: 19470619 DOI: 10.1210/jc.2008-2680] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CONTEXT Maternally inherited diabetes and deafness (MIDD) is a rare form of diabetes with a matrilineal transmission, sensorineural hearing loss, and macular pattern dystrophy due to an A to G transition at position 3243 of mitochondrial DNA (mtDNA) (m.3243A>G). The phenotypic heterogeneity of MIDD may be the consequence of different levels of mutated mtDNA among mitochondria in a given tissue. OBJECTIVE The aim of the present study was thus to ascertain the correlation between the severity of the phenotype in patients with MIDD and the level of heteroplasmy in the blood leukocytes. PARTICIPANTS The GEDIAM prospective multicenter register was initiated in 1995. Eighty-nine Europid patients from this register, with MIDD and the mtDNA 3243A>G mutation, were included. Patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) or with mitochondrial diabetes related to other mutations or to deletions of mtDNA were excluded. RESULTS A significant negative correlation was found between levels of heteroplasmy and age of the patients at the time of sampling for molecular analysis, age at the diagnosis of diabetes, and body mass index. After adjustment for age at sampling for molecular study and gender, the correlation between heteroplasmy levels and age at the diagnosis of diabetes was no more significant. The two other correlations remained significant. A significant positive correlation between levels of heteroplasmy and HbA(1c) was also found and remained significant after adjustment for age at molecular sampling and gender. CONCLUSIONS These results support the hypothesis that heteroplasmy levels are at least one of the determinants of the severity of the phenotype in MIDD.
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Affiliation(s)
- M Laloi-Michelin
- Department of Internal Medicine B, Hôpital Lariboisière, 2 Rue Ambroise Paré, Paris Cedex 10, France
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28
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Akbari M, Skjelbred C, Følling I, Sagen J, Krokan HE. A gel electrophoresis method for detection of mitochondrial DNA mutation (3243 tRNALeu (UUR)) applied to a Norwegian family with diabetes mellitus and hearing loss. Scand J Clin Lab Invest 2009; 64:86-92. [PMID: 15115244 DOI: 10.1080/00365510410004209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Blood cells of selected patients from a large Norwegian family with maternally transmitted diabetes mellitus, hearing loss and muscular dysfunction were screened for possible A3243G mutation tRNA(Leu (UUR)) in mitochondrial DNA. We selected 7 patients from 3 of the 4 generations of the family and 10 unrelated healthy control subjects for mutation analysis using denaturing gradient gel electrophoresis (DGGE) and both manual and automated DNA sequencing. The A3243G mutation was found in peripheral blood cells of all 7 patients, but in none of the controls. The mutation was in the form of heteroplasmy and the amount of mutant DNA was found to be between 10% and 35% of total mtDNA in individual patients. This is the first report of a Norwegian family with maternally inherited diabetes and hearing loss carrying the A3243G mutation in mitochondrial DNA.
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Affiliation(s)
- M Akbari
- Institute of Cancer Research and Molecular Biology, Regional Hospital Trondheim, Norwegian University of Science and Technology, Trondheim, Norway.
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29
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Hosszúfalusi N, Karcagi V, Horváth R, Palik E, Várkonyi J, Rajczy K, Prohászka Z, Szentirmai C, Karádi I, Romics L, Pánczél P. A detailed investigation of maternally inherited diabetes and deafness (MIDD) including clinical characteristics, C-peptide secretion, HLA-DR and -DQ status and autoantibody pattern. Diabetes Metab Res Rev 2009; 25:127-35. [PMID: 19116951 DOI: 10.1002/dmrr.841] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND This article presents a clinically characterization of the mitochondrial DNA mutation (A3243G) associated with maternally inherited diabetes and deafness (MIDD) syndrome in two families. METHODS Six patients with MIDD and one mutation-positive relative with normal glucose tolerance (NGT) were examined. Fasting serum C-peptide was measured in all subjects and compared with controls having NGT (n = 14). C-peptide response to an intravenous glucose tolerance test (IVGTT) was investigated in the diabetic patients not treated with insulin (n = 3) and in the mutation-positive healthy individual and compared with the controls. RESULTS The A3243G heteroplasmy value varied between 5 and 30%. All A3243G carriers had HLA-DR1-DQ5 haplotype, and either the -DQ5 or the -DQ6 allele. The fasting and the serum C-peptide levels at 120 min during the IVGTT did not differ between the A3243G carriers and the controls. A missing first phase and a decreased total C-peptide response was detected in the mutation-positive diabetics compared with controls (p < 0.0001). The same abnormality was found in the A3243G carrier with NGT. Circulating islet cell antibody (ICA) was present in three patients with MIDD. Glutamic acid decarboxylase (GAD), tyrosine phosphatase-like protein IA-2 (IA-2) and mitochondrial antibodies were missing. The diagnosis of MIDD was delayed in each case. CONCLUSIONS A missing first phase and a decreased total C-peptide response during an IVGTT was characteristic for the A3243G mutation. The fasting C-peptide level of the carriers did not differ from the controls. Circulating ICA was present in some patients, but GAD, IA-2 and mitochondrial antibodies were absent. All subjects had HLA-DR1-DQ5 haplotype, and either -DQ5 or -DQ6 alleles.
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Affiliation(s)
- Nóra Hosszúfalusi
- Semmelweis University, Budapest, 3rd Department of Internal Medicine, Budapest, Hungary.
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30
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Murphy R, Ellard S, Hattersley AT. Clinical implications of a molecular genetic classification of monogenic beta-cell diabetes. ACTA ACUST UNITED AC 2008; 4:200-13. [PMID: 18301398 DOI: 10.1038/ncpendmet0778] [Citation(s) in RCA: 388] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 12/14/2007] [Indexed: 02/06/2023]
Abstract
Monogenic diabetes resulting from mutations that primarily reduce beta-cell function accounts for 1-2% of diabetes cases, although it is often misdiagnosed as either type 1 or type 2 diabetes. Knowledge of the genetic etiology of diabetes enables more-appropriate treatment, better prediction of disease progression, screening of family members and genetic counseling. We propose that the old clinical classifications of maturity-onset diabetes of the young and neonatal diabetes are obsolete and that specific genetic etiologies should be sought in four broad clinical situations because of their specific treatment implications. Firstly, diabetes diagnosed before 6 months of age frequently results from mutation of genes that encode Kir6.2 (ATP-sensitive inward rectifier potassium channel) or sulfonylurea receptor 1 subunits of an ATP-sensitive potassium channel, and improved glycemic control can be achieved by treatment with high-dose sulfonylureas rather than insulin. Secondly, patients with stable, mild fasting hyperglycemia detected particularly when they are young could have a glucokinase mutation and might not require specific treatment. Thirdly, individuals with familial, young-onset diabetes that does not fit with either type 1 or type 2 diabetes might have mutations in the transcription factors HNF-1alpha (hepatocyte nuclear factor 1-alpha) or HNF-4alpha, and can be treated with low-dose sulfonylureas. Finally, extrapancreatic features, such as renal disease (caused by mutations in HNF-1beta) or deafness (caused by a mitochondrial m.3243A>G mutation), usually require early treatment with insulin.
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31
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Mizukami H, Wada R, Koyama M, Takeo T, Suga S, Wakui M, Yagihashi S. Augmented beta cell loss and mitochondrial abnormalities in sucrose-fed GK rats. Virchows Arch 2008; 452:383-92. [PMID: 18236074 DOI: 10.1007/s00428-007-0508-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/22/2007] [Accepted: 09/02/2007] [Indexed: 11/27/2022]
Abstract
Progressive decline of islet beta cell mass is a hallmark of type 2 diabetes, where nutritional insults are invoked in the pathologic process. Its detailed mechanisms are, however, incompletely understood. We explored the effect of sucrose diet on mitochondria in Goto Kakizaki (GK) rats, a spontaneously diabetic model. Six-week-old male GK rats were given 30% sucrose orally for 2 weeks. Normal Wistar rats fed with sucrose served as controls. Compared to untreated GK rats, sucrose-fed GK rats showed severe degeneration and death of beta cells with disrupted and swollen mitochondria and a greater beta cell loss. Submicroscopic analysis disclosed a smaller mean volume and a greater number of mitochondria in beta cells in GK rats compared to those in Wistar rats. Mitochondria in sucrose-fed GK rats were 2.4-fold greater in mean volume than those in untreated state. Without sucrose feeding, there was no significant difference in mitochondrial membrane potentials (MmPs) of isolated islets between Wistar and GK rats. MmPs were reduced by 44% in sucrose-fed GK rats but not influenced in sucrose-fed Wistar rats. Current results suggest that nutritional insults like sucrose feeding may exert deleterious effects on mitochondria, resulting in augmented beta cell loss in type 2 diabetes.
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Affiliation(s)
- Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
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Larsen MO, Rolin B, Raun K, Bjerre Knudsen L, Gotfredsen CF, Bock T. Evaluation of beta-cell mass and function in the Göttingen minipig. Diabetes Obes Metab 2007; 9 Suppl 2:170-9. [PMID: 17919191 DOI: 10.1111/j.1463-1326.2007.00785.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Increased knowledge about beta-cell mass and function is important for our understanding of the pathophysiology of type 2 diabetes (T2DM). The relationship between the two is difficult to study in humans, whereas animal models allow studies of consequences of, for example, reduction of beta-cell mass and induction of obesity and procurement of the pancreas for histological examination. An overview of results obtained in the Göttingen minipig in relation to beta-cell function, and mass is provided here. Effects of a primary reduction of beta-cell mass have indicated that not all of the defects of pulsatile insulin secretion in human T2DM can be explained by reduced beta-cell mass. Furthermore, induction of obesity has shown deterioration of beta-cell function and morphological changes in the pancreas. As in humans, obesity leads to an increased beta-cell volume in the minipig, and based on the increased number of islets, neogenesis of islets is an important factor in expansion of beta-cell mass in this species. Measurement of beta-cell function as an estimate of beta-cell mass is, at present, the only method possible in humans, and this approach has been validated using lean and obese minipigs with a range of beta-cell mass. The effects on beta-cell function and mass of obesity of longer duration and/or more pronounced hyperglycaemia remains to be determined, but the models developed so far represent a valuable tool for such investigations.
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Affiliation(s)
- M O Larsen
- Department of GLP-1 and Obesity Pharmacology, Novo Nordisk A/S, Maaloev, Denmark.
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33
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Maassen JA, 't Hart LM, Janssen GMC, Reiling E, Romijn JA, Lemkes HH. Mitochondrial diabetes and its lessons for common Type 2 diabetes. Biochem Soc Trans 2006; 34:819-23. [PMID: 17052206 DOI: 10.1042/bst0340819] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Multiple pathogenic pathways are able to deregulate glucose homoeostasis leading to diabetes. The 3243A>G mutation in the mtDNA (mitochondrial DNA)-encoded tRNALeu,UUR gene was found by us to be associated with a particular diabetic subtype, designated MIDD (maternally inherited diabetes and deafness). This mutation causes an imbalance in the mitochondrion between proteins encoded by the nuclear and mitochondrial genomes, resulting in a gradual deterioration of glucose homoeostasis during life. Remarkably, carriers of the 3243A>G mutation are generally not obese. The mutation also results in enhanced radical production by mitochondria. We propose that this mutation leads to the development of diabetes due to an inappropriate storage of triacylglycerols within adipocytes. The result is a fatty acid-induced deterioration of pancreatic β-cell function. In combination with an enhanced radical production in the β-cell due to the mutation, this leads to an age-dependent, accelerated decline in insulin production. In common Type 2 (non-insulin-dependent) diabetes, which is generally associated with obesity, a decline in mitochondrial function in adipose cells seems to result in an inappropriate scavenging of fatty acids by β-oxidation. As a consequence, a systemic overload with fatty acids occurs, leading to an enhanced decline in β-cell function due to lipotoxicity.
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Affiliation(s)
- J A Maassen
- Department of Molecular Cell Biology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
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34
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Wredenberg A, Freyer C, Sandström ME, Katz A, Wibom R, Westerblad H, Larsson NG. Respiratory chain dysfunction in skeletal muscle does not cause insulin resistance. Biochem Biophys Res Commun 2006; 350:202-7. [PMID: 16996481 DOI: 10.1016/j.bbrc.2006.09.029] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Accepted: 09/07/2006] [Indexed: 01/06/2023]
Abstract
Insulin resistance in skeletal muscle is a characteristic feature of diabetes mellitus type 2 (DM2). Several lines of circumstantial evidence suggest that reduced mitochondrial oxidative phosphorylation capacity in skeletal muscle is a primary defect causing insulin resistance and subsequent development of DM2. We have now experimentally tested this hypothesis by characterizing glucose homeostasis in tissue-specific knockout mice with progressive respiratory chain dysfunction selectively in skeletal muscle. Surprisingly, these knockout mice are not diabetic and have an increased peripheral glucose disposal when subjected to a glucose tolerance test. Studies of isolated skeletal muscle from knockout animals show an increased basal glucose uptake and a normal increase of glucose uptake in response to insulin. In summary, our findings indicate that mitochondrial dysfunction in skeletal muscle is not a primary etiological event in DM2.
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Affiliation(s)
- Anna Wredenberg
- Department of Laboratory Medicine, Karolinska Insitutet, Karolinska University Hospital, Stockholm, Sweden
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35
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Singh R, Ellard S, Hattersley A, Harries LW. Rapid and sensitive real-time polymerase chain reaction method for detection and quantification of 3243A>G mitochondrial point mutation. J Mol Diagn 2006; 8:225-30. [PMID: 16645209 PMCID: PMC1867583 DOI: 10.2353/jmoldx.2006.050067] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Maternally inherited diabetes and deafness and mitochondrial encephalomyopathy, lactic acidosis with stroke-like episodes result from the 3243A>G mitochondrial point mutation. Current methods to detect the presence of the mutation have limited sensitivity and may lead to potential misclassification of patients with low levels of heteroplasmy. Here, we describe development and validation of a rapid real-time polymerase chain reaction (PCR) method for detection and quantification of levels of heteroplasmy in a single assay. Standard curve analysis indicated that the sensitivity of detection was less than 0.1%. Time from sample loading to data analysis was 110 minutes. We tested 293 samples including 23 known positives, 40 known negatives, and 230 samples from patients clinically classified as having type 2 diabetes. All positive samples were correctly detected, and of those samples previously quantified, heteroplasmy levels determined using the real-time assay correlated well (r(2) = 0.88 and 0.93) with results from fluorescently labeled PCR-restriction fragment length polymorphism and pyrosequencing methods. Screening of 230 patients classified as having type 2 diabetes revealed one patient with 0.6% heteroplasmy who had previously tested negative by PCR-restriction fragment length polymorphism. Real-time PCR provides rapid simultaneous detection and quantification of the 3243A>G mutation to a detection limit of less than 0.1%, without post-PCR manipulation.
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Affiliation(s)
- Rinki Singh
- Institute of Biomedical Sciences, Peninsula Medical School, Exeter, EX2 5DW UK
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Abstract
Mitochondria are essential for intermediary metabolism as well as energy production in the cell. Their aerobic metabolism permits oxidation of glucose and fatty acids for the generation of ATP and other intermediates that are exchanged with the cytoplasm for various biosynthetic and secretory processes. In the pancreatic beta-cell, glucose carbons are quantitatively funneled to the mitochondria, where signals for the initiation and potentiation of insulin secretion are generated. After mitochondrial activation, the plasma membrane is depolarized with ensuing cytosolic calcium transients and exocytosis of insulin. Calcium also acts in a feed-forward manner on mitochondrial metabolism, which contributes to sustained second phase insulin secretion. Patients with mitochondrial diabetes and a corresponding mouse model display defective glucose-stimulated insulin secretion and reduced beta-cell mass, leading to overt diabetes. Normal mitochondrial activity appears to be equally important in the action of insulin on its target tissues. The development of insulin resistance may involve impairment of glucose oxidation after short exposure to increased levels of circulating free fatty acids. Insulin resistance in the elderly and in relatives of type 2 diabetic patients has also been associated with mitochondrial dysfunction. Both prevention and treatment of type 2 diabetes should focus on mitochondrial targets for the improvement of nutrient-stimulated insulin secretion and their utilization in peripheral tissues.
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Affiliation(s)
- Andreas Wiederkehr
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
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37
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Abstract
Mitochondria provide cells with most of the energy in the form of adenosine triphosphate (ATP). Mitochondria are complex organelles encoded both by nuclear and mtDNA. Only a few mitochondrial components are encoded by mtDNA, most of the mt-proteins are nuclear DNA encoded. Remarkably, the majority of the known mutations leading to a mitochondrial disease have been identified in mtDNA rather than in nuclear DNA. In general, the idea is that these pathogenic mutations in mtDNA affect energy supply leading to a disease state. Remarkably, different mtDNA mutations can associate with distinct disease states, a situation that is difficult to reconcile with the idea that a reduced ATP production is the sole pathogenic factor. This review deals with emerging insight into the mechanism by which the A3243G mutation in the mitochondrial tRNA (Leu, UUR) gene associates with diabetes as major clinical expression. A decrease in glucose-induced insulin secretion by pancreatic beta-cells and a premature aging of these cells seem to be the main process by which this mutation causes diabetes. The underlying mechanisms and variability in clinical presentation are discussed.
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Affiliation(s)
- Johannes A Maassen
- Department of Molecular Cell Biology LUMC, Leiden University Medical Centre, The Netherlands.
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38
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Nakada K, Sato A, Sone H, Kasahara A, Ikeda K, Kagawa Y, Yonekawa H, Hayashi JI. Accumulation of pathogenic ΔmtDNA induced deafness but not diabetic phenotypes in mito-mice. Biochem Biophys Res Commun 2004; 323:175-84. [PMID: 15351718 DOI: 10.1016/j.bbrc.2004.08.073] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Indexed: 11/19/2022]
Abstract
Mito-mice carrying various proportions of deletion mutant mtDNA (DeltamtDNA) were generated by introduction of the DeltamtDNA from cultured cells into fertilized eggs of C57BL/6J (B6) strain mice. Great advantages of mito-mice are that they share exactly the same nuclear-genome background, and that their genetic variations are restricted to proportions of pathogenic DeltamtDNA. Since accumulation of DeltamtDNA to more than 75% induced respiration defects, the disease phenotypes observed exclusively in mito-mice carrying more than 75% DeltamtDNA should be due to accumulated DeltamtDNA. In this study, we focused on the expressions of hearing loss and diabetic phenotypes, since these common age-associated abnormalities have sometimes been reported to be inherited maternally and to be associated with pathogenic mutant mtDNAs. The results showed that accumulation of exogenously introduced DeltamtDNA was responsible for hearing loss, but not for expression of diabetic phenotypes in mito-mice.
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Affiliation(s)
- Kazuto Nakada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan
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Urata M, Wada Y, Kim SH, Chumpia W, Kayamori Y, Hamasaki N, Kang D. High-sensitivity detection of the A3243G mutation of mitochondrial DNA by a combination of allele-specific PCR and peptide nucleic acid-directed PCR clamping. Clin Chem 2004; 50:2045-51. [PMID: 15364886 DOI: 10.1373/clinchem.2004.033761] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The A3243G mutation of mitochondrial DNA (mtDNA) is involved in many common diseases, including diabetes mellitus and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). For detection of this mutation, allele-specific PCR is highly sensitive but requires strict control of PCR conditions; it thus is not adequate for a routine clinical test. We aimed to develop a routinely available PCR method for quantitative detection of low-level heteroplasmy of the A3243G mutation. METHODS Quantitative allele-specific PCR for the A3243G mutation was performed in the presence of peptide nucleic acid (PNA), in which PNA is complementary to the wild-type mtDNA, with one primer having a 3' end matched to nucleotide position 3243 of the mutant. RESULTS With our method, amplification of wild-type mtDNA was suppressed 7000-fold compared with amplification of the mutant mtDNA under a broad range of conditions: DNA, 5-100 ng; annealing temperature, 61-66 degrees C; and PNA, 1.5-3.5 micromol/L. Hence, 0.1% heteroplasmy of the A3243G mutation can be reliably quantified by this method. Blood samples form 40 healthy volunteers showed <0.06% heteroplasmy, suggesting that 0.1% is diagnostically significant. CONCLUSIONS PNA maintains the specificity of allele-specific PCR over a wide range of conditions, which is important for routine clinical testing.
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Affiliation(s)
- Michiyo Urata
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan
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40
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Larsen MO, Rolin B. Use of the Gottingen Minipig as a Model of Diabetes, with Special Focus on Type 1 Diabetes Research. ILAR J 2004; 45:303-13. [PMID: 15229377 DOI: 10.1093/ilar.45.3.303] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Animal models of type 1 diabetes remain essential tools for investigation of the etiology and pathogenesis of the disease and, importantly, for the development of effective new treatments. Although a range of well-characterized and widely used models of type 1 diabetes in rodents are currently available, large animal models are a valuable complement to rodent models for both physiological and practical reasons. The pig is very useful in many aspects as a model for human physiology and pathophysiology because many organ systems of this species, as well as physiological and pathophysiological responses, resemble those of the human. The Göttingen minipig is particularly suitable for long-term studies because of its inherent small size and ease of handling, even at full maturity. Of particular relevance to the field of type 1 diabetes are the many similarities evident between humans and pigs with regard to pharmacokinetics of compounds after subcutaneous administration, structure and function of the gastrointestinal tract, morphology of the pancreas, and the overall metabolic status of the two species. Because spontaneous type 1-like diabetes is very rare in pigs, a model of the condition must be induced experimentally, either surgically or chemically. This process is discussed, and the use of the pig as a model in islet transplantation and diabetic complications is briefly summarized.
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Affiliation(s)
- Marianne O Larsen
- Department of Pharmacology Research I, Novo Nordisk A/S, Maaloev, Denmark
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41
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Lynn S, Borthwick GM, Charnley RM, Walker M, Turnbull DM. Heteroplasmic ratio of the A3243G mitochondrial DNA mutation in single pancreatic beta cells. Diabetologia 2003; 46:296-9. [PMID: 12627331 DOI: 10.1007/s00125-002-1018-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Accepted: 08/23/2002] [Indexed: 11/27/2022]
Abstract
AIMS/HYPOTHESIS To examine whether there is a high content of mutated mitochondrial DNA in individual pancreatic beta cells from a patient with the A3243G mitochondrial DNA mutation. METHODS Tissues were available from a patient with diabetes and the A3243G mutation including pancreatic tissue. We quantified the amount of mutated mitochondrial DNA in tissue homogenates and single pancreatic beta cells using hot last cycle PCR. RESULTS The percentage ratio of mutated to wild-type mtDNA was high in tissues such as muscle and brain (>60%), but surprisingly low in both pancreatic islets and in individual beta cells from these islets. The islets were smaller in the patient than in control subjects in keeping with a decreased beta-cell mass. CONCLUSIONS/INTERPRETATION These observations suggest that either the beta cells show increased sensitivity to the effects mtDNA mutations on respiratory chain function, and/or cells with a high mutant load are preferentially removed leading to a progressive decrease in the islet beta-cell mass.
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Affiliation(s)
- S Lynn
- Department of Medicine, The Medical School, University of Newcastle upon Tyne, Framlington Place, NE2 4HH Newcastle upon Tyne, United Kingdom
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42
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Silva JP, Larsson NG. Manipulation of mitochondrial DNA gene expression in the mouse. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1555:106-10. [PMID: 12206900 DOI: 10.1016/s0005-2728(02)00263-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondrial dysfunction due to impaired respiratory chain function is increasingly recognized as an important cause of human disease. Mitochondrial disorders are relatively common and have an estimated incidence of 1:10,000 live births. There are more than 100 different point mutations and numerous large rearrangements of mitochondrial DNA (mtDNA; mainly single deletions) that cause human disease. We aimed at obtaining an animal model to study physiological aspects of mtDNA mutation disorders. There are as yet unsolved technical problems associated with transfection of mammalian mitochondria. We therefore choose to manipulate mtDNA expression by targeting of the nuclear gene encoding Tfam. We utilised the cre-loxP recombination system to disrupt Tfam since this system allows manipulation of respiratory chain function in selected mouse tissues. We have found increased cell death or apoptosis induction in both germ line and tissue-specific Tfam knockouts. Our results further suggest that increased production of reactive oxygen species (ROS) is not a prominent feature in cells with impaired mtDNA expression.
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Affiliation(s)
- José P Silva
- Department of Medical Nutrition, Karolinska Institutet, Novum, Huddinge Hospital, S-141 86 Huddinge, Sweden
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Abstract
The aetiology of type 2, or non-insulin-dependent, diabetes mellitus has been characterized in only a limited number of cases. Among these, mitochondrial diabetes, a rare subform of the disease, is the consequence of pancreatic beta-cell dysfunction caused by mutations in mitochondrial DNA, which is distinct from the nuclear genome. The impact of such mutations on beta-cell function reflects the importance of mitochondria in the control of insulin secretion. The beta-cell mitochondria serve as fuel sensors, generating factors that couple nutrient metabolism to the exocytosis of insulin-containing vesicles. The latter process requires an increase in cytosolic Ca2+, which depends on ATP synthesized by the mitochondria. This organelle also generates other factors, of which glutamate has been proposed as a potential intracellular messenger.
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Affiliation(s)
- P Maechler
- Division of Clinical Biochemistry, Department of Internal Medicine, University Medical Centre, 1211 Geneva 4, Switzerland.
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44
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Ohkubo K, Yamano A, Nagashima M, Mori Y, Anzai K, Akehi Y, Nomiyama R, Asano T, Urae A, Ono J. Mitochondrial Gene Mutations in the tRNALeu(UUR) Region and Diabetes: Prevalence and Clinical Phenotypes in Japan. Clin Chem 2001. [DOI: 10.1093/clinchem/47.9.1641] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Background: Mitochondrial gene mutations play a role in the development of diabetes mellitus. We have assessed the frequency of the A3243G and other mitochondrial mutations in Japan and in the relationship to clinical features of diabetes.
Methods: DNA was obtained from peripheral leukocytes of 240 patients with diabetes mellitus (39 with type 1; 188 with type 2; 13 with gestational diabetes) and 125 control subjects. We used PCR-restriction fragment length polymorphism analysis (ApaI) for A3243G and PCR-single-strand conformation polymorphism analysis to determine the mutations in the mitochondrial gene including nucleotide position 3243.
Results: The A3243G mutation was found in seven patients, and an inverse relationship was observed between the degree of heteroplasmy and the age at onset of diabetes. A3156G, G3357A, C3375A, and T3394C were detected in addition. Those who shared the same mutation showed similar clinical characteristics, thus representing a putative clinical subtype. The patients with A3156G had a sudden onset of hyperglycemia and showed a rapid progression to an insulin-dependent state with positive anti-glutamic acid decarboxylase antibody. Those with T3394C showed a mild defect in glucose-stimulated insulin secretion, and hyperglycemia appeared after adding such factors as aging or obesity.
Conclusions: The identification of mitochondrial gene mutations allows preclinical diagnosis of diabetes and prediction of the age at onset by evaluating the degree of heteroplasmy in cases with A3243G. Mutation detection may also be important for patient management and identification of affected family members.
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Affiliation(s)
- Kumiko Ohkubo
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Akemi Yamano
- The First Department of Internal Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Mariko Nagashima
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Yumiko Mori
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Keizo Anzai
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Yuko Akehi
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Riku Nomiyama
- The First Department of Internal Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Takashi Asano
- The First Department of Internal Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Akinori Urae
- Kyushu Clinical Pharmacology Research Clinic, 2-13-16, Jigyo, Chuo-ku, Fukuoka, 810-0065, Japan
| | - Junko Ono
- Department of Laboratory Medicine, Fukuoka University School of Medicine, 7-45-1, Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
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45
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van Essen EH, Roep BO, 't Hart LM, Jansen JJ, Van den Ouweland JM, Lemkes HH, Maassen JA. HLA-DQ polymorphism and degree of heteroplasmy of the A3243G mitochondrial DNA mutation in maternally inherited diabetes and deafness. Diabet Med 2000; 17:841-7. [PMID: 11168326 DOI: 10.1046/j.1464-5491.2000.00379.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM Maternally inherited diabetes and deafness (MIDD) associates with a mutation at position 3243 in mitochondrial DNA. Phenotypic expression of MIDD includes Type 1-like and Type 2-like diabetes. This study examined whether HLA-DQ phenotype and the degree of heteroplasmy in leucocyte and oral mucosa DNA influence clinical expression of the 3242 mutation. METHODS In a group of 20 unrelated probands with MIDD, eight with Type 1- like diabetes, 12 with Type 2-like diabetes, HLA-DQ type and degree of heteroplasmy for the 3243 mutation were determined. HLA-DQA1/DQB1 phenotypes were categorized as predisposing, neutral or protective for autoimmune-mediated Type 1 diabetes. RESULTS No differences were observed between Type 1 and Type 2-like MIDD groups with respect to the cumulative frequency of protective and predisposing HLA-DQ types. Predisposing HLA-DQ types are more prevalent in MIDD patients than in the control population (P < 0.05). Degrees of heteroplasmy for the 3243 mutation showed large variations in patients, ranging from 1 to 52% in leucocyte DNA. A strong correlation was seen between heteroplasmy in leucocyte DNA and DNA from oral mucosa cells (r = 0.89, P < 0.001). No correlation was observed between the degree of heteroplasmy and diabetic phenotype, even when group size was extended with diabetic relatives of patients with MIDD. The age of diagnosis of diabetes was not correlated with heteroplasmy, but the degree of heteroplasmy tended to decrease with age. CONCLUSIONS The phenotype of diabetes in MIDD appears to be independent of HLA-DQ phenotype and degree of heteroplasmy in leucocyte and oral mucosa DNA indicating that other, as yet unknown, factors modulate clinical expression of the 3243 mutation.
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Affiliation(s)
- E H van Essen
- Department of Metabolic Diseases and Endocrinology, Leiden University Medical Centre, The Netherlands.
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46
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Maechler P, Wollheim CB. Mitochondrial signals in glucose-stimulated insulin secretion in the beta cell. J Physiol 2000; 529 Pt 1:49-56. [PMID: 11080250 PMCID: PMC2270172 DOI: 10.1111/j.1469-7793.2000.00049.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Glucose-induced insulin secretion is determined by signals generated in the mitochondria. The elevation of ATP is necessary for the membrane-dependent increase in cytosolic Ca2+, the main trigger of insulin exocytosis. Beta cells depleted of mitochondrial DNA fail to respond to glucose while still secreting insulin in response to membrane depolarisation. This cell model resembles the situation of defective insulin secretion in patients with mitochondrial diabetes. On the other hand, infants with activating mutations in the mitochondrial enzyme glutamate dehydrogenase are characterised by hyperinsulinism and hypoglycaemia. We have recently proposed that glutamate, generated by this enzyme, participates in insulin secretion as a glucose-derived metabolic messenger. In this model, glutamate acts downstream of the mitochondria by sensitising the exocytotic process to Ca2+. The evidence in favour of such a role for glutamate is discussed in the present review.
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Affiliation(s)
- P Maechler
- Division of Clinical Biochemistry, Department of Internal Medicine, University Medical Center, 1211 Geneva 4, Switzerland
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47
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Silva JP, Köhler M, Graff C, Oldfors A, Magnuson MA, Berggren PO, Larsson NG. Impaired insulin secretion and beta-cell loss in tissue-specific knockout mice with mitochondrial diabetes. Nat Genet 2000; 26:336-40. [PMID: 11062475 DOI: 10.1038/81649] [Citation(s) in RCA: 328] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysfunction is an important contributor to human pathology and it is estimated that mutations of mitochondrial DNA (mtDNA) cause approximately 0.5-1% of all types of diabetes mellitus. We have generated a mouse model for mitochondrial diabetes by tissue-specific disruption of the nuclear gene encoding mitochondrial transcription factor A (Tfam, previously mtTFA; ref. 7) in pancreatic beta-cells. This transcriptional activator is imported to mitochondria, where it is essential for mtDNA expression and maintenance. The Tfam-mutant mice developed diabetes from the age of approximately 5 weeks and displayed severe mtDNA depletion, deficient oxidative phosphorylation and abnormal appearing mitochondria in islets at the ages of 7-9 weeks. We performed physiological studies of beta-cell stimulus-secretion coupling in islets isolated from 7-9-week-old mutant mice and found reduced hyperpolarization of the mitochondrial membrane potential, impaired Ca(2+)-signalling and lowered insulin release in response to glucose stimulation. We observed reduced beta-cell mass in older mutants. Our findings identify two phases in the pathogenesis of mitochondrial diabetes; mutant beta-cells initially display reduced stimulus-secretion coupling, later followed by beta-cell loss. This animal model reproduces the beta-cell pathology of human mitochondrial diabetes and provides genetic evidence for a critical role of the respiratory chain in insulin secretion.
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Affiliation(s)
- J P Silva
- Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden
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48
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Ng MC, Yeung VT, Chow CC, Li JK, Smith PR, Mijovic CH, Critchley JA, Barnett AH, Cockram CS, Chan JC. Mitochondrial DNA A3243G mutation in patients with early- or late-onset type 2 diabetes mellitus in Hong Kong Chinese. Clin Endocrinol (Oxf) 2000; 52:557-64. [PMID: 10792334 DOI: 10.1046/j.1365-2265.2000.00989.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES The mitochondrial DNA A to G mutation at nucleotide 3243 (mt3243) is associated with a subtype of diabetes characterized by maternal transmission and deafness. We have previously reported a 2.7% prevalence of this mutation in a cohort of young patients with either type 1 or type 2 diabetes. In this study, we aimed to confirm this finding by examining for the prevalence of this mutation in a large-scale study. SUBJECTS AND METHODS Nine hundred and six unrelated Chinese patients with type 2 diabetes and 213 nondiabetic controls were studied. The presence of mt3243 mutation was determined by polymerase chain reaction amplification and ApaI digestion. RESULTS This mutation was found in four of 133 (3.0%) patients with early onset (</= 40 years) diabetes who also had a positive maternal family history, and in one of 348 (0.3%) patients with late-onset (> 40 years) diabetes and no family history. Basal pancreatic beta-cell function, as assessed by fasting plasma C-peptide, was variable amongst mutation carriers, and did not correlate with the level of heteroplasmy of mutation. CONCLUSIONS In agreement with most studies, our results suggest that despite the high prevalence of positive maternal family history of diabetes amongst our type 2 diabetic patients, mt3243 mutation was not a major cause of diabetes in either early- or late-onset diabetic patients in Hong Kong. The role of other genetic, environmental and intrauterine factors needs further investigation.
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Affiliation(s)
- M C Ng
- Department of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
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49
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Otabe S, Yasuda K, Mori Y, Shimokawa K, Kadowaki H, Jimi A, Nonaka K, Akanuma Y, Yazaki Y, Kadowaki T. Molecular and histological evaluation of pancreata from patients with a mitochondrial gene mutation associated with impaired insulin secretion. Biochem Biophys Res Commun 1999; 259:149-56. [PMID: 10334931 DOI: 10.1006/bbrc.1999.0650] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A mutation in mitochondrial DNA, which was originally identified in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), can be associated with a subtype of diabetes mellitus. To determine the molecular and histological basis of impaired insulin secretion in the subjects with this mutation, we studied autopsy pancreata specimens from eight subjects diagnosed as having MELAS. The 3243 bp mutation was identified in seven out of eight pancreata examined. Immunohistochemical studies demonstrated a reduction in total islet mass, and in the numbers of both B and A cells. No evidence of insulitis or apoptosis was found. These data suggested that the 3243 bp mutation may cause the reduction of islet cells, mainly through mechanisms other than autoimmune destruction.
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Affiliation(s)
- S Otabe
- Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Tokyo, 113-0033, Japan
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50
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Yamasoba T, Tsukuda K, Oka Y, Kobayashi T, Kaga K. Cochlear histopathology associated with mitochondrial transfer RNA(Leu(UUR)) gene mutation. Neurology 1999; 52:1705-7. [PMID: 10331707 DOI: 10.1212/wnl.52.8.1705] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Using dot-blot hybridization and Southern blotting, the authors detected a point mutation at nucleotide pair (np) 3243 in mitochondrial DNA from temporal bone sections of a woman with diabetes and deafness. The mutation could not be detected with agarose gel electrophoresis, suggesting that the degree of heteroplasmy is low. Histologically, there was marked degeneration of the stria vascularis and outer hair cells throughout the cochlea, as well as a reduction of spiral ganglion cells in the base. These findings suggest that the mutation affects these inner ear structures preferentially and that deafness can occur even when the proportion of np 3243 mutation is low.
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Affiliation(s)
- T Yamasoba
- Department of Otolaryngology, University of Tokyo, Japan.
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