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Rönn T, Ofori JK, Perfilyev A, Hamilton A, Pircs K, Eichelmann F, Garcia-Calzon S, Karagiannopoulos A, Stenlund H, Wendt A, Volkov P, Schulze MB, Mulder H, Eliasson L, Ruhrmann S, Bacos K, Ling C. Genes with epigenetic alterations in human pancreatic islets impact mitochondrial function, insulin secretion, and type 2 diabetes. Nat Commun 2023; 14:8040. [PMID: 38086799 PMCID: PMC10716521 DOI: 10.1038/s41467-023-43719-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
Epigenetic dysregulation may influence disease progression. Here we explore whether epigenetic alterations in human pancreatic islets impact insulin secretion and type 2 diabetes (T2D). In islets, 5,584 DNA methylation sites exhibit alterations in T2D cases versus controls and are associated with HbA1c in individuals not diagnosed with T2D. T2D-associated methylation changes are found in enhancers and regions bound by β-cell-specific transcription factors and associated with reduced expression of e.g. CABLES1, FOXP1, GABRA2, GLR1A, RHOT1, and TBC1D4. We find RHOT1 (MIRO1) to be a key regulator of insulin secretion in human islets. Rhot1-deficiency in β-cells leads to reduced insulin secretion, ATP/ADP ratio, mitochondrial mass, Ca2+, and respiration. Regulators of mitochondrial dynamics and metabolites, including L-proline, glycine, GABA, and carnitines, are altered in Rhot1-deficient β-cells. Islets from diabetic GK rats present Rhot1-deficiency. Finally, RHOT1methylation in blood is associated with future T2D. Together, individuals with T2D exhibit epigenetic alterations linked to mitochondrial dysfunction in pancreatic islets.
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Affiliation(s)
- Tina Rönn
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Jones K Ofori
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Alexander Perfilyev
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Alexander Hamilton
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
- Department of Biology, University of Copenhagen, København, Denmark
| | - Karolina Pircs
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, Lund University, Lund, Sweden
- HCEMM-Su, Neurobiology and Neurodegenerative Diseases Research Group, Budapest, Hungary
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Fabian Eichelmann
- Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
- German Center for Diabetes Research, München-Neuherberg, Germany
| | - Sonia Garcia-Calzon
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
- Department of Food Science and Physiology, Centre for Nutrition Research, University of Navarra, Pamplona, Spain
| | - Alexandros Karagiannopoulos
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Hans Stenlund
- Swedish Metabolomics Centre, Umeå University, Umeå, Sweden
| | - Anna Wendt
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Petr Volkov
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Matthias B Schulze
- Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
- German Center for Diabetes Research, München-Neuherberg, Germany
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - Hindrik Mulder
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Lena Eliasson
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Sabrina Ruhrmann
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Karl Bacos
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden.
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Bacos K, Perfilyev A, Karagiannopoulos A, Cowan E, Ofori JK, Bertonnier-Brouty L, Rönn T, Lindqvist A, Luan C, Ruhrmann S, Ngara M, Nilsson Å, Gheibi S, Lyons CL, Lagerstedt JO, Barghouth M, Esguerra JL, Volkov P, Fex M, Mulder H, Wierup N, Krus U, Artner I, Eliasson L, Prasad RB, Cataldo LR, Ling C. Type 2 diabetes candidate genes, including PAX5, cause impaired insulin secretion in human pancreatic islets. J Clin Invest 2023; 133:163612. [PMID: 36656641 PMCID: PMC9927941 DOI: 10.1172/jci163612] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/05/2023] [Indexed: 01/20/2023] Open
Abstract
Type 2 diabetes (T2D) is caused by insufficient insulin secretion from pancreatic β cells. To identify candidate genes contributing to T2D pathophysiology, we studied human pancreatic islets from approximately 300 individuals. We found 395 differentially expressed genes (DEGs) in islets from individuals with T2D, including, to our knowledge, novel (OPRD1, PAX5, TET1) and previously identified (CHL1, GLRA1, IAPP) candidates. A third of the identified expression changes in islets may predispose to diabetes, as expression of these genes associated with HbA1c in individuals not previously diagnosed with T2D. Most DEGs were expressed in human β cells, based on single-cell RNA-Seq data. Additionally, DEGs displayed alterations in open chromatin and associated with T2D SNPs. Mouse KO strains demonstrated that the identified T2D-associated candidate genes regulate glucose homeostasis and body composition in vivo. Functional validation showed that mimicking T2D-associated changes for OPRD1, PAX5, and SLC2A2 impaired insulin secretion. Impairments in Pax5-overexpressing β cells were due to severe mitochondrial dysfunction. Finally, we discovered PAX5 as a potential transcriptional regulator of many T2D-associated DEGs in human islets. Overall, we have identified molecular alterations in human pancreatic islets that contribute to β cell dysfunction in T2D pathophysiology.
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Affiliation(s)
- Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
| | | | - Alexandros Karagiannopoulos
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden
| | - Elaine Cowan
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden
| | - Jones K. Ofori
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
| | - Ludivine Bertonnier-Brouty
- Endocrine Cell Differentiation, Department of Laboratory Medicine, Lund Stem Cell Center, Malmö, Scania, Sweden
| | - Tina Rönn
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
| | - Andreas Lindqvist
- Neuroendocrine Cell Biology, Department of Experimental Medical Science
| | - Cheng Luan
- Unit of Islet Pathophysiology, Department of Clinical Sciences
| | - Sabrina Ruhrmann
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
| | - Mtakai Ngara
- Neuroendocrine Cell Biology, Department of Experimental Medical Science
| | - Åsa Nilsson
- Human Tissue Lab, Department of Clinical Sciences
| | - Sevda Gheibi
- Molecular Metabolism Unit, Department of Clinical Sciences, and
| | - Claire L. Lyons
- Molecular Metabolism Unit, Department of Clinical Sciences, and
| | - Jens O. Lagerstedt
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden
| | | | - Jonathan L.S. Esguerra
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
| | - Malin Fex
- Molecular Metabolism Unit, Department of Clinical Sciences, and
| | - Hindrik Mulder
- Molecular Metabolism Unit, Department of Clinical Sciences, and
| | - Nils Wierup
- Neuroendocrine Cell Biology, Department of Experimental Medical Science
| | - Ulrika Krus
- Human Tissue Lab, Department of Clinical Sciences
| | - Isabella Artner
- Endocrine Cell Differentiation, Department of Laboratory Medicine, Lund Stem Cell Center, Malmö, Scania, Sweden
| | - Lena Eliasson
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden
| | - Rashmi B. Prasad
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Scania, Sweden.,Institute of Molecular Medicine (FIMM), Helsinki University, Helsinki, Finland
| | - Luis Rodrigo Cataldo
- Molecular Metabolism Unit, Department of Clinical Sciences, and,The Novo Nordisk Foundation Centre for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences and
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Abstract
Pioneering studies performed over the past few decades demonstrate links between epigenetics and type 2 diabetes mellitus (T2DM), the metabolic disorder with the most rapidly increasing prevalence in the world. Importantly, these studies identified epigenetic modifications, including altered DNA methylation, in pancreatic islets, adipose tissue, skeletal muscle and the liver from individuals with T2DM. As non-genetic factors that affect the risk of T2DM, such as obesity, unhealthy diet, physical inactivity, ageing and the intrauterine environment, have been associated with epigenetic modifications in healthy individuals, epigenetics probably also contributes to T2DM development. In addition, genetic factors associated with T2DM and obesity affect the epigenome in human tissues. Notably, causal mediation analyses found DNA methylation to be a potential mediator of genetic associations with metabolic traits and disease. In the past few years, translational studies have identified blood-based epigenetic markers that might be further developed and used for precision medicine to help patients with T2DM receive optimal therapy and to identify patients at risk of complications. This Review focuses on epigenetic mechanisms in the development of T2DM and the regulation of body weight in humans, with a special focus on precision medicine.
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Affiliation(s)
- Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden.
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Tina Rönn
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
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dos Santos C, Karagiannopoulos A, Rafacho A, Perfilyev A, Eliasson L, Ling C, Bacos K. Glucocorticoids and glucolipotoxicity alter the DNA methylome and function of human EndoC-βH1 cells. Life Sci 2022; 307:120854. [DOI: 10.1016/j.lfs.2022.120854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/20/2022] [Accepted: 07/27/2022] [Indexed: 10/16/2022]
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Dos Santos C, Rafacho A, Ferreira SM, Vettorazzi JF, Dos Reis Araújo T, Mateus Gonçalves L, Ruhrmann S, Bacos K, Ling C, Boschero AC, Jorge Dos Santos G. Excess of glucocorticoids during late gestation impairs the recovery of offspring's β-cell function after a postnatal injury. FASEB J 2021; 35:e21828. [PMID: 34325494 DOI: 10.1096/fj.202100841r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/05/2021] [Accepted: 07/15/2021] [Indexed: 11/11/2022]
Abstract
Since prenatal glucocorticoids (GC) excess increases the risk of metabolic dysfunctions in the offspring and its effect on β-cell recovery capacity remains unknown we investigated these aspects in offspring from mice treated with dexamethasone (DEX) in the late pregnancy. Half of the pups were treated with streptozotocin (STZ) on the sixth postnatal day (PN). Functional and molecular analyses were performed in male offspring on PN25 and PN225. Prenatal DEX treatment resulted in low birth weight. At PN25, both the STZ-treated offspring developed hyperglycemia and had lower β-cell mass, in parallel with higher α-cell mass and glucose intolerance, with no impact of prenatal DEX on such parameters. At PN225, the β-cell mass was partially recovered in the STZ-treated mice, but they remained glucose-intolerant, irrespective of being insulin sensitive. Prenatal exposition to DEX predisposed adult offspring to sustained hyperglycemia and perturbed islet function (lower insulin and higher glucagon response to glucose) in parallel with exacerbated glucose intolerance. β-cell-specific knockdown of the Hnf4α in mice from the DS group resulted in exacerbated glucose intolerance. We conclude that high GC exposure during the prenatal period exacerbates the metabolic dysfunctions in adult life of mice exposed to STZ early in life, resulting in a lesser ability to recover the islets' function over time. This study alerts to the importance of proper management of exogenous GCs during pregnancy and a healthy postnatal lifestyle since the combination of adverse factors during the prenatal and postnatal period accentuates the predisposition to metabolic disorders in adult life.
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Affiliation(s)
- Cristiane Dos Santos
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Alex Rafacho
- Laboratory of Investigation in Chronic Diseases - LIDoC, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Sandra Mara Ferreira
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Jean Franciesco Vettorazzi
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Thiago Dos Reis Araújo
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Luciana Mateus Gonçalves
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Sabrina Ruhrmann
- Epigenetics and Diabetes Unit, Department of Clinical Sciences Malmö, Lund University Diabetes Center, Scania University Hospital, Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences Malmö, Lund University Diabetes Center, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences Malmö, Lund University Diabetes Center, Scania University Hospital, Malmö, Sweden
| | - Antônio Carlos Boschero
- Laboratory of Endocrine Pancreas and Metabolism - LAPEM, Department of Structural and Functional Biology, Institute of Biology, Campinas State University - UNICAMP, Campinas, Brazil
| | - Gustavo Jorge Dos Santos
- Laboratory of Investigation in Chronic Diseases - LIDoC, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
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García-Calzón S, Perfilyev A, Martinell M, Ustinova M, Kalamajski S, Franks PW, Bacos K, Elbere I, Pihlajamäki J, Volkov P, Vaag A, Groop L, Maziarz M, Klovins J, Ahlqvist E, Ling C. Epigenetic markers associated with metformin response and intolerance in drug-naïve patients with type 2 diabetes. Sci Transl Med 2020; 12:12/561/eaaz1803. [DOI: 10.1126/scitranslmed.aaz1803] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/27/2020] [Accepted: 08/24/2020] [Indexed: 12/14/2022]
Abstract
Metformin is the first-line pharmacotherapy for managing type 2 diabetes (T2D). However, many patients with T2D do not respond to or tolerate metformin well. Currently, there are no phenotypes that successfully predict glycemic response to, or tolerance of, metformin. We explored whether blood-based epigenetic markers could discriminate metformin response and tolerance by analyzing genome-wide DNA methylation in drug-naïve patients with T2D at the time of their diagnosis. DNA methylation of 11 and 4 sites differed between glycemic responders/nonresponders and metformin-tolerant/intolerant patients, respectively, in discovery and replication cohorts. Greater methylation at these sites associated with a higher risk of not responding to or not tolerating metformin with odds ratios between 1.43 and 3.09 per 1-SD methylation increase. Methylation risk scores (MRSs) of the 11 identified sites differed between glycemic responders and nonresponders with areas under the curve (AUCs) of 0.80 to 0.98. MRSs of the 4 sites associated with future metformin intolerance generated AUCs of 0.85 to 0.93. Some of these blood-based methylation markers mirrored the epigenetic pattern in adipose tissue, a key tissue in diabetes pathogenesis, and genes to which these markers were annotated to had biological functions in hepatocytes that altered metformin-related phenotypes. Overall, we could discriminate between glycemic responders/nonresponders and participants tolerant/intolerant to metformin at diagnosis by measuring blood-based epigenetic markers in drug-naïve patients with T2D. This epigenetics-based tool may be further developed to help patients with T2D receive optimal therapy.
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Affiliation(s)
- Sonia García-Calzón
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
- Department of Nutrition, Food Science and Physiology, University of Navarra, 31008 Pamplona, Spain
| | - Alexander Perfilyev
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
| | - Mats Martinell
- Department of Public Health and Caring Sciences, Uppsala University, 751 22 Uppsala, Sweden
| | - Monta Ustinova
- Latvian Biomedical Research and Study Centre, Rātsupītes Street 1, k-1, Riga LV-1067, Latvia
| | - Sebastian Kalamajski
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, 214 28 Malmö, Sweden
| | - Paul W. Franks
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, 214 28 Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
| | - Ilze Elbere
- Latvian Biomedical Research and Study Centre, Rātsupītes Street 1, k-1, Riga LV-1067, Latvia
| | - Jussi Pihlajamäki
- Institute of Public Health and Clinical Nutrition, Internal Medicine, University of Eastern Finland, 70211 Kuopio, Finland
- Clinical Nutrition and Obesity Center, Kuopio University Hospital, 70210 Kuopio, Finland
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
| | - Allan Vaag
- Type 2 Diabetes Biology Research, Steno Diabetes Center, 2820 Gentofte, Denmark
| | - Leif Groop
- Genomics, Diabetes and Endocrinology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
| | - Marlena Maziarz
- Bioinformatics Unit, Department of Clinical Sciences, Lund University Diabetes Centre, 214 28 Malmö, Sweden
| | - Janis Klovins
- Latvian Biomedical Research and Study Centre, Rātsupītes Street 1, k-1, Riga LV-1067, Latvia
- Faculty of Biology, University of Latvia, Riga LV-1004, Latvia
| | - Emma Ahlqvist
- Genomics, Diabetes and Endocrinology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 214 28 Malmö, Sweden
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7
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Huang TT, Smith R, Bacos K, Song DY, Faull RM, Waldvogel HJ, Li JY. No symphony without bassoon and piccolo: changes in synaptic active zone proteins in Huntington's disease. Acta Neuropathol Commun 2020; 8:77. [PMID: 32493491 PMCID: PMC7268643 DOI: 10.1186/s40478-020-00949-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/19/2020] [Indexed: 11/10/2022] Open
Abstract
Prominent features of HD neuropathology are the intranuclear and cytoplasmic inclusions of huntingtin and striatal and cortical neuronal cell death. Recently, synaptic defects have been reported on HD-related studies, including impairment of neurotransmitter release and alterations of synaptic components. However, the definite characteristics of synapse dysfunction and the underlying mechanisms remain largely unknown. We studied the gene expression levels and patterns of a number of proteins forming the cytoskeletal matrix of the presynaptic active zones in HD transgenic mice (R6/1), in hippocampal neuronal cultures overexpressing mutant huntingtin and in postmortem brain tissues of HD patients. To investigate the interactions between huntingtin and active proteins, we performed confocal microscopic imaging and immunoprecipitation in mouse and HEK 293 cell line models. The mRNA and protein levels of Bassoon were reduced in mouse and cell culture models of HD and in brain tissues of patients with HD. Moreover, a striking re-distribution of a complex of proteins including Bassoon, Piccolo and Munc 13-1 from the cytoplasm and synapses into intranuclear huntingtin aggregates with loss of active zone proteins and dendritic spines. This re-localization was age-dependent and coincided with the formation of huntingtin aggregates. Using co-immunoprecipitation, we demonstrated that huntingtin interacts with Bassoon, and that this interaction is likely mediated by a third linking protein. Three structural proteins involved in neurotransmitter release in the presynaptic active zones of neurons are altered in expression and that the proteins are redistributed from their normal functional site into mutant huntingtin aggregates.
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Bysani M, Agren R, Davegårdh C, Volkov P, Rönn T, Unneberg P, Bacos K, Ling C. Author Correction: ATAC-seq reveals alterations in open chromatin in pancreatic islets from subjects with type 2 diabetes. Sci Rep 2020; 10:1744. [PMID: 31996742 PMCID: PMC6989682 DOI: 10.1038/s41598-020-58485-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Madhusudhan Bysani
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Rasmus Agren
- Department of Biology and Biological Engineering, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Chalmers University of Technology, Göteborg, Sweden
| | - Cajsa Davegårdh
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Tina Rönn
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Per Unneberg
- Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden.
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Hall E, Jönsson J, Ofori JK, Volkov P, Perfilyev A, Dekker Nitert M, Eliasson L, Ling C, Bacos K. Glucolipotoxicity Alters Insulin Secretion via Epigenetic Changes in Human Islets. Diabetes 2019; 68:1965-1974. [PMID: 31420409 DOI: 10.2337/db18-0900] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 07/24/2019] [Indexed: 11/13/2022]
Abstract
Type 2 diabetes (T2D) is characterized by insufficient insulin secretion and elevated glucose levels, often in combination with high levels of circulating fatty acids. Long-term exposure to high levels of glucose or fatty acids impair insulin secretion in pancreatic islets, which could partly be due to epigenetic alterations. We studied the effects of high concentrations of glucose and palmitate combined for 48 h (glucolipotoxicity) on the transcriptome, the epigenome, and cell function in human islets. Glucolipotoxicity impaired insulin secretion, increased apoptosis, and significantly (false discovery rate <5%) altered the expression of 1,855 genes, including 35 genes previously implicated in T2D by genome-wide association studies (e.g., TCF7L2 and CDKN2B). Additionally, metabolic pathways were enriched for downregulated genes. Of the differentially expressed genes, 1,469 also exhibited altered DNA methylation (e.g., CDK1, FICD, TPX2, and TYMS). A luciferase assay showed that increased methylation of CDK1 directly reduces its transcription in pancreatic β-cells, supporting the idea that DNA methylation underlies altered expression after glucolipotoxicity. Follow-up experiments in clonal β-cells showed that knockdown of FICD and TPX2 alters insulin secretion. Together, our novel data demonstrate that glucolipotoxicity changes the epigenome in human islets, thereby altering gene expression and possibly exacerbating the secretory defect in T2D.
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Affiliation(s)
- Elin Hall
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Josefine Jönsson
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Jones K Ofori
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Alexander Perfilyev
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Marloes Dekker Nitert
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
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10
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Bysani M, Agren R, Davegårdh C, Volkov P, Rönn T, Unneberg P, Bacos K, Ling C. ATAC-seq reveals alterations in open chromatin in pancreatic islets from subjects with type 2 diabetes. Sci Rep 2019; 9:7785. [PMID: 31123324 PMCID: PMC6533306 DOI: 10.1038/s41598-019-44076-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 05/08/2019] [Indexed: 01/08/2023] Open
Abstract
Impaired insulin secretion from pancreatic islets is a hallmark of type 2 diabetes (T2D). Altered chromatin structure may contribute to the disease. We therefore studied the impact of T2D on open chromatin in human pancreatic islets. We used assay for transposase-accessible chromatin using sequencing (ATAC-seq) to profile open chromatin in islets from T2D and non-diabetic donors. We identified 57,105 and 53,284 ATAC-seq peaks representing open chromatin regions in islets of non-diabetic and diabetic donors, respectively. The majority of ATAC-seq peaks mapped near transcription start sites. Additionally, peaks were enriched in enhancer regions and in regions where islet-specific transcription factors (TFs), e.g. FOXA2, MAFB, NKX2.2, NKX6.1 and PDX1, bind. Islet ATAC-seq peaks overlap with 13 SNPs associated with T2D (e.g. rs7903146, rs2237897, rs757209, rs11708067 and rs878521 near TCF7L2, KCNQ1, HNF1B, ADCY5 and GCK, respectively) and with additional 67 SNPs in LD with known T2D SNPs (e.g. SNPs annotated to GIPR, KCNJ11, GLIS3, IGF2BP2, FTO and PPARG). There was enrichment of open chromatin regions near highly expressed genes in human islets. Moreover, 1,078 open chromatin peaks, annotated to 898 genes, differed in prevalence between diabetic and non-diabetic islet donors. Some of these peaks are annotated to candidate genes for T2D and islet dysfunction (e.g. HHEX, HMGA2, GLIS3, MTNR1B and PARK2) and some overlap with SNPs associated with T2D (e.g. rs3821943 near WFS1 and rs508419 near ANK1). Enhancer regions and motifs specific to key TFs including BACH2, FOXO1, FOXA2, NEUROD1, MAFA and PDX1 were enriched in differential islet ATAC-seq peaks of T2D versus non-diabetic donors. Our study provides new understanding into how T2D alters the chromatin landscape, and thereby accessibility for TFs and gene expression, in human pancreatic islets.
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Affiliation(s)
- Madhusudhan Bysani
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Rasmus Agren
- Department of Biology and Biological Engineering, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Chalmers University of Technology, Göteborg, Sweden
| | - Cajsa Davegårdh
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Tina Rönn
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Per Unneberg
- Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden.
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Backe MB, Jin C, Andreone L, Sankar A, Agger K, Helin K, Madsen AN, Poulsen SS, Bysani M, Bacos K, Ling C, Perone MJ, Holst B, Mandrup-Poulsen T. The Lysine Demethylase KDM5B Regulates Islet Function and Glucose Homeostasis. J Diabetes Res 2019; 2019:5451038. [PMID: 31467927 PMCID: PMC6701283 DOI: 10.1155/2019/5451038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/06/2019] [Accepted: 06/04/2019] [Indexed: 12/17/2022] Open
Abstract
AIMS Posttranslational modifications of histones and transcription factors regulate gene expression and are implicated in beta-cell failure and diabetes. We have recently shown that preserving H3K27 and H3K4 methylation using the lysine demethylase inhibitor GSK-J4 reduces cytokine-induced destruction of beta-cells and improves beta-cell function. Here, we investigate the therapeutic potential of GSK-J4 to prevent diabetes development and examine the importance of H3K4 methylation for islet function. MATERIALS AND METHODS We used two mouse models of diabetes to investigate the therapeutic potential of GSK-J4. To clarify the importance of H3K4 methylation, we characterized a mouse strain with knockout (KO) of the H3K4 demethylase KDM5B. RESULTS GSK-J4 administration failed to prevent the development of experimental diabetes induced by multiple low-dose streptozotocin or adoptive transfer of splenocytes from acutely diabetic NOD to NODscid mice. KDM5B-KO mice were growth retarded with altered body composition, had low IGF-1 levels, and exhibited reduced insulin secretion. Interestingly, despite secreting less insulin, KDM5B-KO mice were able to maintain normoglycemia following oral glucose tolerance test, likely via improved insulin sensitivity, as suggested by insulin tolerance testing and phosphorylation of proteins belonging to the insulin signaling pathway. When challenged with high-fat diet, KDM5B-deficient mice displayed similar weight gain and insulin sensitivity as wild-type mice. CONCLUSION Our results show a novel role of KDM5B in metabolism, as KDM5B-KO mice display growth retardation and improved insulin sensitivity.
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Affiliation(s)
- Marie Balslev Backe
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
- Institute of Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Chunyu Jin
- Institute of Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Luz Andreone
- Immuno-endocrinology, Diabetes & Metabolism Laboratory, Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, CONICET–Universidad Austral, Argentina
| | - Aditya Sankar
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
- The Novo Nordisk Foundation Center for Stem Cell Biology, Denmark
| | - Karl Agger
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
- The Novo Nordisk Foundation Center for Stem Cell Biology, Denmark
| | - Kristian Helin
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
- The Novo Nordisk Foundation Center for Stem Cell Biology, Denmark
| | - Andreas Nygaard Madsen
- Institute of Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Steen Seier Poulsen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Denmark
| | - Madhusudhan Bysani
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmo, Sweden
| | - Karl Bacos
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmo, Sweden
| | - Charlotte Ling
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmo, Sweden
| | - Marcelo Javier Perone
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
- Immuno-endocrinology, Diabetes & Metabolism Laboratory, Instituto de Investigaciones en Medicina Traslacional, Facultad de Ciencias Biomédicas, CONICET–Universidad Austral, Argentina
| | - Birgitte Holst
- Institute of Pharmacology, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Thomas Mandrup-Poulsen
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
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Daneshpajooh M, Eliasson L, Bacos K, Ling C. MC1568 improves insulin secretion in islets from type 2 diabetes patients and rescues β-cell dysfunction caused by Hdac7 upregulation. Acta Diabetol 2018; 55:1231-1235. [PMID: 30088095 PMCID: PMC6244806 DOI: 10.1007/s00592-018-1201-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/25/2018] [Indexed: 01/07/2023]
Abstract
AIMS It has in recent years been established that epigenetic changes contribute to β-cell dysfunction and type 2 diabetes (T2D). For example, we have showed that the expression of histone deacetylase 7 (HDAC7) is increased in pancreatic islets of individuals with T2D and that increased levels of Hdac7 in β-cells impairs insulin secretion. The HDAC inhibitor MC1568 rescued this secretory impairment, suggesting that inhibitors specific for HDAC7 may be useful clinically in the treatment of T2D. The aim of the current study was to further explore HDAC7 as a novel therapeutic target in T2D. METHODS Hdac7 was overexpressed in clonal β-cells followed by the analysis of insulin secretion, mitochondrial function, as well as cell number and apoptosis in the presence or absence of MC1568. Furthermore, the effect of MC1568 on insulin secretion in human pancreatic islets from non-diabetic donors and donors with T2D was also studied. RESULTS Overexpression of Hdac7 in clonal β-cells significantly reduced insulin secretion, mitochondrial respiration, and ATP content, while it increased apoptosis. These impairments were all rescued by treatment with MC1568. The inhibitor also increased glucose-stimulated insulin secretion in islets from donors with T2D, while having no effect on islets from non-diabetic donors. CONCLUSIONS HDAC7 inhibition protects β-cells from mitochondrial dysfunction and apoptosis, and increases glucose-stimulated insulin secretion in islets from human T2D donors. Our study supports specific HDAC7 inhibitors as novel options in the treatment of T2D.
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Affiliation(s)
- Mahboubeh Daneshpajooh
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, CRC 91:12, Box 50332, 20213, Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, CRC 91:11, Box 50332, 20213, Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, CRC 91:12, Box 50332, 20213, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, CRC 91:12, Box 50332, 20213, Malmö, Sweden.
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Hall E, Dekker Nitert M, Volkov P, Malmgren S, Mulder H, Bacos K, Ling C. The effects of high glucose exposure on global gene expression and DNA methylation in human pancreatic islets. Mol Cell Endocrinol 2018; 472:57-67. [PMID: 29183809 DOI: 10.1016/j.mce.2017.11.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 10/20/2017] [Accepted: 11/23/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUND Type 2 diabetes (T2D) is a complex disease characterised by chronic hyperglycaemia. The effects of elevated glucose on global gene expression in combination with DNA methylation patterns have not yet been studied in human pancreatic islets. Our aim was to study the impact of 48 h exposure to high (19 mM) versus control (5.6 mM) glucose levels on glucose-stimulated insulin secretion, gene expression and DNA methylation in human pancreatic islets. RESULTS While islets kept at 5.6 mM glucose secreted significantly more insulin in response to short term glucose-stimulation (p = 0.0067), islets exposed to high glucose for 48 h were desensitised and unresponsive to short term glucose-stimulation with respect to insulin secretion (p = 0.32). Moreover, the exposure of human islets to 19 mM glucose resulted in significantly altered expression of eight genes (FDR<5%), with five of these (GLRA1, RASD1, VAC14, SLCO5A1, CHRNA5) also exhibiting changes in DNA methylation (p < 0.05). A gene set enrichment analysis of the expression data showed significant enrichment of e.g. TGF-beta signalling pathway, Notch signalling pathway and SNARE interactions in vesicular transport; these pathways are of relevance for islet function and possibly also diabetes. We also found increased DNA methylation of CpG sites annotated to PDX1 in human islets exposed to 19 mM glucose for 48 h. Finally, we could functionally validate a role for Glra1 in insulin secretion. CONCLUSION Our data demonstrate that high glucose levels affect human pancreatic islet gene expression and several of these genes also exhibit epigenetic changes. This might contribute to the impaired insulin secretion seen in T2D.
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Affiliation(s)
- Elin Hall
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Marloes Dekker Nitert
- School of Medicine, Royal Brisbane Clinical School, The University of Queensland, Herston Qld 4029, Australia
| | - Petr Volkov
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Siri Malmgren
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden; Molecular Metabolism, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Hindrik Mulder
- Molecular Metabolism, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden.
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Davegårdh C, García-Calzón S, Bacos K, Ling C. DNA methylation in the pathogenesis of type 2 diabetes in humans. Mol Metab 2018; 14:12-25. [PMID: 29496428 PMCID: PMC6034041 DOI: 10.1016/j.molmet.2018.01.022] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 02/08/2023] Open
Abstract
Background Type 2 diabetes (T2D) is a multifactorial, polygenic disease caused by impaired insulin secretion and insulin resistance. Genome-wide association studies (GWAS) were expected to resolve a large part of the genetic component of diabetes; yet, the single nucleotide polymorphisms identified by GWAS explain less than 20% of the estimated heritability for T2D. There was subsequently a need to look elsewhere to find disease-causing factors. Mechanisms mediating the interaction between environmental factors and the genome, such as epigenetics, may be of particular importance in the pathogenesis of T2D. Scope of Review This review summarizes knowledge of the impact of epigenetics on the pathogenesis of T2D in humans. In particular, the review will focus on alterations in DNA methylation in four human tissues of importance for the disease; pancreatic islets, skeletal muscle, adipose tissue, and the liver. Case–control studies and studies examining the impact of non-genetic and genetic risk factors on DNA methylation in humans will be considered. These studies identified epigenetic changes in tissues from subjects with T2D versus non-diabetic controls. They also demonstrate that non-genetic factors associated with T2D such as age, obesity, energy rich diets, physical activity and the intrauterine environment impact the epigenome in humans. Additionally, interactions between genetics and epigenetics seem to influence the pathogenesis of T2D. Conclusions Overall, previous studies by our group and others support a key role for epigenetics in the growing incidence of T2D.
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Affiliation(s)
- Cajsa Davegårdh
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden.
| | - Sonia García-Calzón
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes, Lund University Diabetes Centre (LUDC), Box 50332, 20213 Malmö, Sweden
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Backe MB, Andersson JL, Bacos K, Christensen DP, Hansen JB, Dorosz JJ, Gajhede M, Dahlby T, Bysani M, Kristensen LH, Ling C, Olsen L, Mandrup-Poulsen T. Lysine demethylase inhibition protects pancreatic β cells from apoptosis and improves β-cell function. Mol Cell Endocrinol 2018; 460:47-56. [PMID: 28684291 DOI: 10.1016/j.mce.2017.07.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/27/2017] [Accepted: 07/02/2017] [Indexed: 01/04/2023]
Abstract
Transcriptional changes control β-cell survival in response to inflammatory stress. Posttranslational modifications of histone and non-histone transcriptional regulators activate or repress gene transcription, but the link to cell-fate signaling is unclear. Inhibition of lysine deacetylases (KDACs) protects β cells from cytokine-induced apoptosis and reduces type 1 diabetes incidence in animals. We hypothesized that also lysine demethylases (KDMs) regulate β-cell fate in response to inflammatory stress. Expression of the demethylase Kdm6B was upregulated by proinflammatory cytokines suggesting a possible role in inflammation-induced β-cell destruction. Inhibition of KDM6 demethylases using the selective inhibitor GSK-J4 protected insulin-producing cells and human and mouse islets from cytokine-induced apoptosis by blunting nuclear factor (NF)-κB signaling and endoplasmic reticulum (ER) stress response gene expression. GSK-J4 furthermore increased expression of insulin gene and glucose-stimulated insulin secretion. Expression of genes regulating purinergic and cytokine ligand-receptor interactions was downregulated following GSK-J4 exposure, while expression of genes involved in cell maintenance and survival was upregulated. These data suggest that KDMs are important regulators of inflammation-induced β-cell dysfunction and death.
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Affiliation(s)
- Marie Balslev Backe
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Jan Legaard Andersson
- Section of Biostructural Reseach, Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Karl Bacos
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmö, Sweden
| | - Dan Ploug Christensen
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Jakob Bondo Hansen
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Jerzy Jòzef Dorosz
- Section of Biostructural Reseach, Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Michael Gajhede
- Section of Biostructural Reseach, Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Tina Dahlby
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Madhusudhan Bysani
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmö, Sweden
| | - Line Hyltoft Kristensen
- Section of Biostructural Reseach, Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Charlotte Ling
- Unit for Epigenetics and Diabetes, Department of Clinical Sciences, Lund University, Scania University Hospital, Malmö, Sweden
| | - Lars Olsen
- Section of Biostructural Reseach, Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Thomas Mandrup-Poulsen
- Immuno-endocrinology Laboratory, Department of Biomedical Sciences, University of Copenhagen, Denmark.
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Volkov P, Bacos K, Ofori JK, Esguerra JLS, Eliasson L, Rönn T, Ling C. Whole-Genome Bisulfite Sequencing of Human Pancreatic Islets Reveals Novel Differentially Methylated Regions in Type 2 Diabetes Pathogenesis. Diabetes 2017; 66:1074-1085. [PMID: 28052964 DOI: 10.2337/db16-0996] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/28/2016] [Indexed: 11/13/2022]
Abstract
Current knowledge about the role of epigenetics in type 2 diabetes (T2D) remains limited. Only a few studies have investigated DNA methylation of selected candidate genes or a very small fraction of genomic CpG sites in human pancreatic islets, the tissue of primary pathogenic importance for diabetes. Our aim was to characterize the whole-genome DNA methylation landscape in human pancreatic islets, to identify differentially methylated regions (DMRs) in diabetic islets, and to investigate the function of DMRs in islet biology. Here, we performed whole-genome bisulfite sequencing, which is a comprehensive and unbiased method to study DNA methylation throughout the genome at a single nucleotide resolution, in pancreatic islets from donors with T2D and control subjects without diabetes. We identified 25,820 DMRs in islets from individuals with T2D. These DMRs cover loci with known islet function, e.g., PDX1, TCF7L2, and ADCY5 Importantly, binding sites previously identified by ChIP-seq for islet-specific transcription factors, enhancer regions, and different histone marks were enriched in the T2D-associated DMRs. We also identified 457 genes, including NR4A3, PARK2, PID1, SLC2A2, and SOCS2, that had both DMRs and significant expression changes in T2D islets. To mimic the situation in T2D islets, candidate genes were overexpressed or silenced in cultured β-cells. This resulted in impaired insulin secretion, thereby connecting differential methylation to islet dysfunction. We further explored the islet methylome and found a strong link between methylation levels and histone marks. Additionally, DNA methylation in different genomic regions and of different transcript types (i.e., protein coding, noncoding, and pseudogenes) was associated with islet expression levels. Our study provides a comprehensive picture of the islet DNA methylome in individuals with and without diabetes and highlights the importance of epigenetic dysregulation in pancreatic islets and T2D pathogenesis.
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Affiliation(s)
- Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Jones K Ofori
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Jonathan Lou S Esguerra
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Tina Rönn
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
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Daneshpajooh M, Bacos K, Bysani M, Bagge A, Ottosson Laakso E, Vikman P, Eliasson L, Mulder H, Ling C. HDAC7 is overexpressed in human diabetic islets and impairs insulin secretion in rat islets and clonal beta cells. Diabetologia 2017; 60:116-125. [PMID: 27796421 PMCID: PMC6518079 DOI: 10.1007/s00125-016-4113-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/30/2016] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS Pancreatic beta cell dysfunction is a prerequisite for the development of type 2 diabetes. Histone deacetylases (HDACs) may affect pancreatic endocrine function and glucose homeostasis through alterations in gene regulation. Our aim was to investigate the role of HDAC7 in human and rat pancreatic islets and clonal INS-1 beta cells (INS-1 832/13). METHODS To explore the role of HDAC7 in pancreatic islets and clonal beta cells, we used RNA sequencing, mitochondrial functional analyses, microarray techniques, and HDAC inhibitors MC1568 and trichostatin A. RESULTS Using RNA sequencing, we found increased HDAC7 expression in human pancreatic islets from type 2 diabetic compared with non-diabetic donors. HDAC7 expression correlated negatively with insulin secretion in human islets. To mimic the situation in type 2 diabetic islets, we overexpressed Hdac7 in rat islets and clonal beta cells. In both, Hdac7 overexpression resulted in impaired glucose-stimulated insulin secretion. Furthermore, it reduced insulin content, mitochondrial respiration and cellular ATP levels in clonal beta cells. Overexpression of Hdac7 also led to changes in the genome-wide gene expression pattern, including increased expression of Tcf7l2 and decreased expression of gene sets regulating DNA replication and repair as well as nucleotide metabolism. In accordance, Hdac7 overexpression reduced the number of beta cells owing to enhanced apoptosis. Finally, we found that inhibiting HDAC7 activity with pharmacological inhibitors or small interfering RNA-mediated knockdown restored glucose-stimulated insulin secretion in beta cells that were overexpressing Hdac7. CONCLUSIONS/INTERPRETATION Taken together, these results indicate that increased HDAC7 levels caused beta cell dysfunction and may thereby contribute to defects seen in type 2 diabetic islets. Our study supports HDAC7 inhibitors as a therapeutic option for the treatment of type 2 diabetes.
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Affiliation(s)
- Mahboubeh Daneshpajooh
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, 20502, Malmö, Sweden
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, 20502, Malmö, Sweden
| | - Madhusudhan Bysani
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, 20502, Malmö, Sweden
| | - Annika Bagge
- Molecular Metabolism Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
| | - Emilia Ottosson Laakso
- Diabetes and Endocrinology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
| | - Petter Vikman
- Diabetes and Endocrinology Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, Malmö, Sweden
| | - Hindrik Mulder
- Molecular Metabolism Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, 20502, Malmö, Sweden.
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Keller M, Hopp L, Liu X, Wohland T, Rohde K, Cancello R, Klös M, Bacos K, Kern M, Eichelmann F, Dietrich A, Schön MR, Gärtner D, Lohmann T, Dreßler M, Stumvoll M, Kovacs P, DiBlasio AM, Ling C, Binder H, Blüher M, Böttcher Y. Genome-wide DNA promoter methylation and transcriptome analysis in human adipose tissue unravels novel candidate genes for obesity. Mol Metab 2016; 6:86-100. [PMID: 28123940 PMCID: PMC5220399 DOI: 10.1016/j.molmet.2016.11.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/03/2016] [Accepted: 11/10/2016] [Indexed: 02/04/2023] Open
Abstract
Objective/methods DNA methylation plays an important role in obesity and related metabolic complications. We examined genome-wide DNA promoter methylation along with mRNA profiles in paired samples of human subcutaneous adipose tissue (SAT) and omental visceral adipose tissue (OVAT) from non-obese vs. obese individuals. Results We identified negatively correlated methylation and expression of several obesity-associated genes in our discovery dataset and in silico replicated ETV6 in two independent cohorts. Further, we identified six adipose tissue depot-specific genes (HAND2, HOXC6, PPARG, SORBS2, CD36, and CLDN1). The effects were further supported in additional independent cohorts. Our top hits might play a role in adipogenesis and differentiation, obesity, lipid metabolism, and adipose tissue expandability. Finally, we show that in vitro methylation of SORBS2 directly represses gene expression. Conclusions Taken together, our data show distinct tissue specific epigenetic alterations which associate with obesity. Obesity-associated differences in DNA promoter methylation and transcriptome in human adipose tissue (ETV6). Depot-specific analyses revealed novel/known genes (HAND2, HOXC6, PPARG, SORBS2, CD36, CLDN1). EWAS revealed SSPN and CCDC125 associated to BMI in SAT or OVAT, respectively. Differentially methylated genes overlap in part with GWAS hits for obesity and fat distribution.
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Affiliation(s)
- Maria Keller
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Lydia Hopp
- Interdisciplinary Centre for Bioinformatics, University of Leipzig, Leipzig, 04103, Germany
| | - Xuanshi Liu
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany; Bioinformatics Group, Department of Computer Science, University of Leipzig, 04107, Leipzig, Germany
| | - Tobias Wohland
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Kerstin Rohde
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Raffaella Cancello
- Molecular Biology Laboratory, Istituto Auxologico Italiano IRCCS, Milan, 20149, Italy
| | - Matthias Klös
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Karl Bacos
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 205 02, Malmoe, Sweden
| | - Matthias Kern
- Department of Medicine, University of Leipzig, Leipzig, 04103, Germany
| | - Fabian Eichelmann
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Arne Dietrich
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany; Department of Surgery, University of Leipzig, Leipzig, 04103, Germany
| | - Michael R Schön
- Städtisches Klinikum Karlsruhe, Clinic of Visceral Surgery, Karlsruhe, 76133, Germany
| | - Daniel Gärtner
- Städtisches Klinikum Karlsruhe, Clinic of Visceral Surgery, Karlsruhe, 76133, Germany
| | - Tobias Lohmann
- Municipal Clinic Dresden-Neustadt, Dresden, 01129, Germany
| | - Miriam Dreßler
- Municipal Clinic Dresden-Neustadt, Dresden, 01129, Germany
| | - Michael Stumvoll
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany; Department of Medicine, University of Leipzig, Leipzig, 04103, Germany
| | - Peter Kovacs
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany
| | - Anna-Maria DiBlasio
- Molecular Biology Laboratory, Istituto Auxologico Italiano IRCCS, Milan, 20149, Italy
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Scania University Hospital, 205 02, Malmoe, Sweden
| | - Hans Binder
- Interdisciplinary Centre for Bioinformatics, University of Leipzig, Leipzig, 04103, Germany
| | - Matthias Blüher
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany; Department of Medicine, University of Leipzig, Leipzig, 04103, Germany.
| | - Yvonne Böttcher
- IFB Adiposity Diseases, University of Leipzig, Leipzig, 04103, Germany.
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Hall E, Volkov P, Dayeh T, Esguerra JLS, Salö S, Eliasson L, Rönn T, Bacos K, Ling C. Sex differences in the genome-wide DNA methylation pattern and impact on gene expression, microRNA levels and insulin secretion in human pancreatic islets. Genome Biol 2014; 15:522. [PMID: 25517766 PMCID: PMC4256841 DOI: 10.1186/s13059-014-0522-z] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 10/30/2014] [Indexed: 12/19/2022] Open
Abstract
Background Epigenetic factors regulate tissue-specific expression and X-chromosome inactivation. Previous studies have identified epigenetic differences between sexes in some human tissues. However, it is unclear whether epigenetic modifications contribute to sex-specific differences in insulin secretion and metabolism. Here, we investigate the impact of sex on the genome-wide DNA methylation pattern in human pancreatic islets from 53 males and 34 females, and relate the methylome to changes in expression and insulin secretion. Results Glucose-stimulated insulin secretion is higher in female versus male islets. Genome-wide DNA methylation data in human islets clusters based on sex. While the chromosome-wide DNA methylation level on the X-chromosome is higher in female versus male islets, the autosomes do not display a global methylation difference between sexes. Methylation of 8,140 individual X-chromosome sites and 470 autosomal sites shows sex-specific differences in human islets. These include sites in/near AR, DUSP9, HNF4A, BCL11A and CDKN2B. 61 X-chromosome genes and 18 autosomal genes display sex-specific differences in both DNA methylation and expression. These include NKAP, SPESP1 and APLN, which exhibited lower expression in females. Functional analyses demonstrate that methylation of NKAP and SPESP1 promoters in vitro suppresses their transcriptional activity. Silencing of Nkap or Apln in clonal beta-cells results in increased insulin secretion. Differential methylation between sexes is associated with altered levels of microRNAs miR-660 and miR-532 and related target genes. Conclusions Chromosome-wide and gene-specific sex differences in DNA methylation associate with altered expression and insulin secretion in human islets. Our data demonstrate that epigenetics contribute to sex-specific metabolic phenotypes. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0522-z) contains supplementary material, which is available to authorized users.
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Olsson AH, Volkov P, Bacos K, Dayeh T, Hall E, Nilsson EA, Ladenvall C, Rönn T, Ling C. Genome-wide associations between genetic and epigenetic variation influence mRNA expression and insulin secretion in human pancreatic islets. PLoS Genet 2014; 10:e1004735. [PMID: 25375650 PMCID: PMC4222689 DOI: 10.1371/journal.pgen.1004735] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 09/05/2014] [Indexed: 12/29/2022] Open
Abstract
Genetic and epigenetic mechanisms may interact and together affect biological processes and disease development. However, most previous studies have investigated genetic and epigenetic mechanisms independently, and studies examining their interactions throughout the human genome are lacking. To identify genetic loci that interact with the epigenome, we performed the first genome-wide DNA methylation quantitative trait locus (mQTL) analysis in human pancreatic islets. We related 574,553 single nucleotide polymorphisms (SNPs) with genome-wide DNA methylation data of 468,787 CpG sites targeting 99% of RefSeq genes in islets from 89 donors. We identified 67,438 SNP-CpG pairs in cis, corresponding to 36,783 SNPs (6.4% of tested SNPs) and 11,735 CpG sites (2.5% of tested CpGs), and 2,562 significant SNP-CpG pairs in trans, corresponding to 1,465 SNPs (0.3% of tested SNPs) and 383 CpG sites (0.08% of tested CpGs), showing significant associations after correction for multiple testing. These include reported diabetes loci, e.g. ADCY5, KCNJ11, HLA-DQA1, INS, PDX1 and GRB10. CpGs of significant cis-mQTLs were overrepresented in the gene body and outside of CpG islands. Follow-up analyses further identified mQTLs associated with gene expression and insulin secretion in human islets. Causal inference test (CIT) identified SNP-CpG pairs where DNA methylation in human islets is the potential mediator of the genetic association with gene expression or insulin secretion. Functional analyses further demonstrated that identified candidate genes (GPX7, GSTT1 and SNX19) directly affect key biological processes such as proliferation and apoptosis in pancreatic β-cells. Finally, we found direct correlations between DNA methylation of 22,773 (4.9%) CpGs with mRNA expression of 4,876 genes, where 90% of the correlations were negative when CpGs were located in the region surrounding transcription start site. Our study demonstrates for the first time how genome-wide genetic and epigenetic variation interacts to influence gene expression, islet function and potential diabetes risk in humans. Inter-individual variation in genetics and epigenetics affects biological processes and disease susceptibility. However, most studies have investigated genetic and epigenetic mechanisms independently and to uncover novel mechanisms affecting disease susceptibility there is a highlighted need to study interactions between these factors on a genome-wide scale. To identify novel loci affecting islet function and potentially diabetes, we performed the first genome-wide methylation quantitative trait locus (mQTL) analysis in human pancreatic islets including DNA methylation of 468,787 CpG sites located throughout the genome. Our results showed that DNA methylation of 11,735 CpGs in 4,504 unique genes is regulated by genetic factors located in cis (67,438 SNP-CpG pairs). Furthermore, significant mQTLs cover previously reported diabetes loci including KCNJ11, INS, HLA, PDX1 and GRB10. We also found mQTLs associated with gene expression and insulin secretion in human islets. By performing causality inference tests (CIT), we identified CpGs where DNA methylation potentially mediates the genetic impact on gene expression and insulin secretion. Our functional follow-up experiments further demonstrated that identified mQTLs/genes (GPX7, GSTT1 and SNX19) directly affect pancreatic β-cell function. Together, our study provides a detailed map of genome-wide associations between genetic and epigenetic variation, which affect gene expression and insulin secretion in human pancreatic islets.
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Affiliation(s)
- Anders H. Olsson
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Petr Volkov
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Karl Bacos
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Tasnim Dayeh
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Elin Hall
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Emma A. Nilsson
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Claes Ladenvall
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Tina Rönn
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Charlotte Ling
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
- * E-mail:
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McCabe KE, Bacos K, Lu D, Delaney JR, Vamos M, Cosford NDP, Stupack DG. Abstract 1340: Induction of necroptosis in ovarian cancer cells as a therapeutic strategy. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-1340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The standard of care for ovarian cancer patients is carboplatin and paclitaxel. While many tumors initially respond to these drugs, patients often relapse with resistant disease. One of the mechanisms implicated in this development of resistance is evasion of apoptosis. Exploiting alternative death pathways, including necroptosis, is one strategy to treat such recurrent disease. Overexpressed in many cancers, inhibitor of apoptosis proteins (IAPs) represent one family of promising targets. Treatment of cells with an IAP antagonist can activate apoptosis or, if caspases are blocked, necroptosis. Among a panel of ovarian cancer cell lines screened for sensitivity to an IAP antagonist in combination with a pan-caspase inhibitor, only one (OVCAR3) was found to be sensitive, but this sensitivity was also exhibited by serous ovarian cancer cells isolated from patients. Combination treatment induces the formation of a p62-associated necrosome (RIPK1/RIPK3/FADD/caspase-8), and death can be rescued with inhibitors of RIPK1 and MLKL, two key proteins in the necroptosis pathway. All sensitive cell lines, but no resistant lines, express RIPK3 protein, and data from knockdown and ectopic expression studies demonstrate the dependency of cell death on kinase-active RIPK3, as well as caspase-8. Studies using a TNFα neutralizing antibody suggest that the combination elicits autocrine production of TNFα, which likely, in turn, activates the extrinsic death pathway in these cells. In conclusion, these findings illustrate that necroptosis can be induced in RIPK3-expressing ovarian cancer cells and indicate that in vivo studies are warranted.
Citation Format: Katelyn E. McCabe, Karl Bacos, Dan Lu, Joe R. Delaney, Mitchell Vamos, Nicholas D. P. Cosford, Dwayne G. Stupack. Induction of necroptosis in ovarian cancer cells as a therapeutic strategy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1340. doi:10.1158/1538-7445.AM2014-1340
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Hall E, Volkov P, Dayeh T, Bacos K, Rönn T, Nitert MD, Ling C. Effects of palmitate on genome-wide mRNA expression and DNA methylation patterns in human pancreatic islets. BMC Med 2014; 12:103. [PMID: 24953961 PMCID: PMC4065864 DOI: 10.1186/1741-7015-12-103] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 04/25/2014] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Circulating free fatty acids are often elevated in patients with type 2 diabetes (T2D) and obese individuals. Chronic exposure to high levels of saturated fatty acids has detrimental effects on islet function and insulin secretion. Altered gene expression and epigenetics may contribute to T2D and obesity. However, there is limited information on whether fatty acids alter the genome-wide transcriptome profile in conjunction with DNA methylation patterns in human pancreatic islets. To dissect the molecular mechanisms linking lipotoxicity to impaired insulin secretion, we investigated the effects of a 48 h palmitate treatment in vitro on genome-wide mRNA expression and DNA methylation patterns in human pancreatic islets. METHODS Genome-wide mRNA expression was analyzed using Affymetrix GeneChip(®) Human Gene 1.0 ST whole transcript-based array (n = 13) and genome-wide DNA methylation was analyzed using Infinium HumanMethylation450K BeadChip (n = 13) in human pancreatic islets exposed to palmitate or control media for 48 h. A non-parametric paired Wilcoxon statistical test was used to analyze mRNA expression. Apoptosis was measured using Apo-ONE(®) Homogeneous Caspase-3/7 Assay (n = 4). RESULTS While glucose-stimulated insulin secretion was decreased, there was no significant effect on apoptosis in human islets exposed to palmitate. We identified 1,860 differentially expressed genes in palmitate-treated human islets. These include candidate genes for T2D, such as TCF7L2, GLIS3, HNF1B and SLC30A8. Additionally, genes in glycolysis/gluconeogenesis, pyruvate metabolism, fatty acid metabolism, glutathione metabolism and one carbon pool by folate were differentially expressed in palmitate-treated human islets. Palmitate treatment altered the global DNA methylation level and DNA methylation levels of CpG island shelves and shores, 5'UTR, 3'UTR and gene body regions in human islets. Moreover, 290 genes with differential expression had a corresponding change in DNA methylation, for example, TCF7L2 and GLIS3. Importantly, out of the genes differentially expressed due to palmitate treatment in human islets, 67 were also associated with BMI and 37 were differentially expressed in islets from T2D patients. CONCLUSION Our study demonstrates that palmitate treatment of human pancreatic islets gives rise to epigenetic modifications that together with altered gene expression may contribute to impaired insulin secretion and T2D.
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Affiliation(s)
| | | | | | | | | | | | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, CRC, Lund University, Scania University Hospital, Malmö, Sweden.
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Malmgren S, Nicholls DG, Taneera J, Bacos K, Koeck T, Tamaddon A, Wibom R, Groop L, Ling C, Mulder H, Sharoyko VV. Tight coupling between glucose and mitochondrial metabolism in clonal beta-cells is required for robust insulin secretion. J Biol Chem 2009; 284:32395-404. [PMID: 19797055 DOI: 10.1074/jbc.m109.026708] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The biochemical mechanisms underlying glucose-stimulated insulin secretion from pancreatic beta-cells are not completely understood. To identify metabolic disturbances in beta-cells that impair glucose-stimulated insulin secretion, we compared two INS-1-derived clonal beta-cell lines, which are glucose-responsive (832/13 cells) or glucose-unresponsive (832/2 cells). To this end, we analyzed a number of parameters in glycolytic and mitochondrial metabolism, including mRNA expression of genes involved in cellular energy metabolism. We found that despite a marked impairment of glucose-stimulated insulin secretion, 832/2 cells exhibited a higher rate of glycolysis. Still, no glucose-induced increases in respiratory rate, ATP production, or respiratory chain complex I, III, and IV activities were seen in the 832/2 cells. Instead, 832/2 cells, which expressed lactate dehydrogenase A, released lactate regardless of ambient glucose concentrations. In contrast, the glucose-responsive 832/13 line lacked lactate dehydrogenase and did not produce lactate. Accordingly, in 832/2 cells mRNA expression of genes for glycolytic enzymes were up-regulated, whereas mitochondria-related genes were down-regulated. This could account for a Warburg-like effect in the 832/2 cell clone, lacking in 832/13 cells as well as primary beta-cells. In human islets, mRNA expression of genes such as lactate dehydrogenase A and hexokinase I correlated positively with HbA(1c) levels, reflecting perturbed long term glucose homeostasis, whereas that of Slc2a2 (glucose transporter 2) correlated negatively with HbA(1c) and thus better metabolic control. We conclude that tight metabolic regulation enhancing mitochondrial metabolism and restricting glycolysis in 832/13 cells is required for clonal beta-cells to secrete insulin robustly in response to glucose. Moreover, a similar expression pattern of genes controlling glycolytic and mitochondrial metabolism in clonal beta-cells and human islets was observed, suggesting that a similar prioritization of mitochondrial metabolism is required in healthy human beta-cells. The 832 beta-cell lines may be helpful tools to resolve metabolic perturbations occurring in Type 2 diabetes.
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Affiliation(s)
- Siri Malmgren
- Department of Clinical Sciences in Malmö, Unit of Molecular Metabolism, Lund University Diabetes Centre, 205 02 Malmö, Sweden
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Smith R, Bacos K, Fedele V, Soulet D, Walz HA, Obermuller S, Lindqvist A, Bjorkqvist M, Klein P, Onnerfjord P, Brundin P, Mulder H, Li JY. Mutant huntingtin interacts with -tubulin and disrupts vesicular transport and insulin secretion. Hum Mol Genet 2009; 18:3942-54. [DOI: 10.1093/hmg/ddp336] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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van der Burg JM, Bacos K, Wood NI, Lindqvist A, Wierup N, Woodman B, Wamsteeker JI, Smith R, Deierborg T, Kuhar MJ, Bates GP, Mulder H, Erlanson-Albertsson C, Morton AJ, Brundin P, Petersén Å, Björkqvist M. Increased metabolism in the R6/2 mouse model of Huntington’s disease. Neurobiol Dis 2008; 29:41-51. [DOI: 10.1016/j.nbd.2007.07.029] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 07/03/2007] [Accepted: 07/29/2007] [Indexed: 11/24/2022] Open
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Anderson K, Rusterholz C, Månsson R, Jensen CT, Bacos K, Zandi S, Sasaki Y, Nerlov C, Sigvardsson M, Jacobsen SEW. Ectopic expression of PAX5 promotes maintenance of biphenotypic myeloid progenitors coexpressing myeloid and B-cell lineage-associated genes. Blood 2007; 109:3697-705. [PMID: 17218387 DOI: 10.1182/blood-2006-05-026021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
AbstractThe transcription factor PAX5 is a critical regulator of B-cell commitment and development. Although normally not expressed in myeloid progenitors, PAX5 has recently been shown to be frequently expressed in myeloid malignancies and to suppress expression of myeloid differentiation genes, compatible with an effect on the differentiation or maintenance of myeloid progenitors. However, previous studies in which PAX5 was ectopically expressed in normal myeloid progenitors in vivo and in vitro provided conflicting results as to the effect of PAX5 on myeloid development. Herein, we demonstrate that on ectopic expression of PAX5 in bone marrow multipotent stem/progenitor cells, cells with a biphenotypic B220+GR-1/MAC-1+ phenotype are produced. These remain cytokine-dependent, but unlike control-transduced cells they sustain long-term generation of myeloid progenitors in vitro and remain capable of myeloid differentiation. Notably, PAX5+B220+GR-1/MAC-1+ myeloid progenitors coexpress, at the single-cell level, myeloid genes and otherwise B-cell–specific PAX5 target genes. These findings establish that ectopic expression of PAX5 introduces extensive self-renewal properties in otherwise short-lived myeloid progenitors. Along with the established ectopic expression of PAX5 in acute myeloid leukemia, this motivates a careful investigation of the potential involvement of ectopic PAX5 expression in myeloid and biphenotypic leukemias.
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Affiliation(s)
- Kristina Anderson
- Hematopoietic Stem Cell Laboratory, Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund University, Klinikgatan 26, 221 84 Lund, Sweden
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Björkqvist M, Petersén A, Bacos K, Isaacs J, Norlén P, Gil J, Popovic N, Sundler F, Bates GP, Tabrizi SJ, Brundin P, Mulder H. Progressive alterations in the hypothalamic-pituitary-adrenal axis in the R6/2 transgenic mouse model of Huntington's disease. Hum Mol Genet 2006; 15:1713-21. [PMID: 16613897 DOI: 10.1093/hmg/ddl094] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Huntington's disease (HD) is characterized by a triad of motor, psychiatric and cognitive symptoms. Although many of these symptoms are likely to be related to central nervous system pathology, others may be due to changes in peripheral tissues. The R6/2 mouse, a transgenic model of HD expressing exon 1 of the human HD gene, develops progressive alterations in the hypothalamic-pituitary-adrenal axis, reminiscent of a Cushing-like syndrome. We observed muscular atrophy, reduced bone mineral density, abdominal fat accumulation and insulin resistance in the mice. All these changes could be consequences of increased glucocorticoid levels. Indeed, hypertrophy of the adrenal cortex and a progressive increase in serum and urine corticosterone levels were found in R6/2 mice. In addition, the intermediate pituitary lobe was markedly enlarged and circulating adreno-corticotrophic hormone (ACTH) increased. Under normal conditions dopamine represses the ACTH expression. In the R6/2 mice, however, the expression of pituitary dopamine D2 receptors was reduced by half, possibly explaining the increase in ACTH. Urinary samples from 82 HD patients and 68 control subjects were analysed for cortisol: in accord with the observations in the R6/2 mice, urinary cortisol increased in parallel with disease progression. This progressive increase in cortisol may contribute to the clinical symptoms, such as muscular wasting, mood changes and some of the cognitive deficits that occur in HD.
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Affiliation(s)
- Maria Björkqvist
- Neuronal Survival Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, BMC A10, Lund, Sweden.
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Björkqvist M, Fex M, Renström E, Wierup N, Petersén A, Gil J, Bacos K, Popovic N, Li JY, Sundler F, Brundin P, Mulder H. The R6/2 transgenic mouse model of Huntington's disease develops diabetes due to deficient beta-cell mass and exocytosis. Hum Mol Genet 2005; 14:565-74. [PMID: 15649949 DOI: 10.1093/hmg/ddi053] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Diabetes frequently develops in Huntington's disease (HD) patients and in transgenic mouse models of HD such as the R6/2 mouse. The underlying mechanisms have not been clarified. Elucidating the pathogenesis of diabetes in HD would improve our understanding of the molecular mechanisms involved in HD neuropathology. With this aim, we examined our colony of R6/2 mice with respect to glucose homeostasis and islet function. At week 12, corresponding to end-stage HD, R6/2 mice were hyperglycemic and hypoinsulinemic and failed to release insulin in an intravenous glucose tolerance test. In vitro, basal and glucose-stimulated insulin secretion was markedly reduced. Islet nuclear huntingtin inclusions increased dramatically over time, predominantly in beta-cells. beta-cell mass failed to increase normally with age in R6/2 mice. Hence, at week 12, beta-cell mass and pancreatic insulin content in R6/2 mice were 35+/-5 and 16+/-3% of that in wild-type mice, respectively. The normally occurring replicating cells were largely absent in R6/2 islets, while no abnormal cell death could be detected. Single cell patch-clamp experiments revealed unaltered electrical activity in R6/2 beta-cells. However, exocytosis was virtually abolished in beta- but not in alpha-cells. The blunting of exocytosis could be attributed to a 96% reduction in the number of insulin-containing secretory vesicles. Thus, diabetes in R6/2 mice is caused by a combination of deficient beta-cell mass and disrupted exocytosis.
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Fex M, Olofsson CS, Fransson U, Bacos K, Lindvall H, Sörhede-Winzell M, Rorsman P, Holm C, Mulder H. Hormone-sensitive lipase deficiency in mouse islets abolishes neutral cholesterol ester hydrolase activity but leaves lipolysis, acylglycerides, fat oxidation, and insulin secretion intact. Endocrinology 2004; 145:3746-53. [PMID: 15142983 DOI: 10.1210/en.2003-1673] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lipids are thought to serve as coupling factors in insulin secretion. Hormone-sensitive lipase (HSL) is expressed in pancreatic beta-cells and could potentially regulate insulin secretion via mobilization of stored triglycerides. Here, we examined the impact of HSL deficiency on fuel metabolism and insulin secretion in mouse islets. Lack of HSL resulted in abrogation of neutral cholesterol ester hydrolase activity, whereas diglyceride lipase activity remained intact. Although glucose stimulates lipolysis in rat islets, elevation of glucose with or without addition of cAMP failed to increase lipolysis in mouse islets regardless of genotype, as indicated by release of glycerol from islets. Storage of lipids, assayed as total acylglycerides, was unaltered in HSL null islets, and oxidation of fatty acids or glucose was not different. The intracellular rise in Ca(2+) triggered by glucose and its subsequent oscillations was unaffected in HSL null islets. Accordingly, insulin secretion in static incubations of islets, in response to fuel- and nonfuel secretagogues, was in no instance significantly different between wild-type and HSL null mice. The lacking impact of HSL deficiency on insulin secretion may be attributed to the failure of insulin secretagogues to stimulate lipolysis. Consequently, a regulatory function of lipid mobilization in insulin secretion in the mouse appears unlikely.
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Affiliation(s)
- Malin Fex
- Department of Cell and Molecular Biology, Lund University, SE-221 84, Lund Sweden
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