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Javeed N, Brown MR, Rakshit K, Her T, Sen SK, Matveyenko AV. Proinflammatory Cytokine Interleukin 1β Disrupts β-cell Circadian Clock Function and Regulation of Insulin Secretion. Endocrinology 2021; 162:bqaa084. [PMID: 32455427 PMCID: PMC7692023 DOI: 10.1210/endocr/bqaa084] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/21/2020] [Indexed: 12/24/2022]
Abstract
Intrinsic β-cell circadian clocks are important regulators of insulin secretion and overall glucose homeostasis. Whether the circadian clock in β-cells is perturbed following exposure to prodiabetogenic stressors such as proinflammatory cytokines, and whether these perturbations are featured during the development of diabetes, remains unknown. To address this, we examined the effects of cytokine-mediated inflammation common to the pathophysiology of diabetes, on the physiological and molecular regulation of the β-cell circadian clock. Specifically, we provide evidence that the key diabetogenic cytokine IL-1β disrupts functionality of the β-cell circadian clock and impairs circadian regulation of glucose-stimulated insulin secretion. The deleterious effects of IL-1β on the circadian clock were attributed to impaired expression of key circadian transcription factor Bmal1, and its regulator, the NAD-dependent deacetylase, Sirtuin 1 (SIRT1). Moreover, we also identified that Type 2 diabetes in humans is associated with reduced immunoreactivity of β-cell BMAL1 and SIRT1, suggestive of a potential causative link between islet inflammation, circadian clock disruption, and β-cell failure. These data suggest that the circadian clock in β-cells is perturbed following exposure to proinflammatory stressors and highlights the potential for therapeutic targeting of the circadian system for treatment for β-cell failure in diabetes.
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Affiliation(s)
- Naureen Javeed
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Matthew R Brown
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Kuntol Rakshit
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Tracy Her
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Satish K Sen
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Aleksey V Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
- Department of Medicine, Division of Endocrinology, Metabolism, Diabetes, and Nutrition, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
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Al-Romaiyan A, Liu B, Persaud S, Jones P. A novel Gymnema sylvestre extract protects pancreatic beta-cells from cytokine-induced apoptosis. Phytother Res 2019; 34:161-172. [PMID: 31515869 DOI: 10.1002/ptr.6512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/04/2019] [Accepted: 08/29/2019] [Indexed: 01/17/2023]
Abstract
Inflammatory cytokines such as interleukin-1β, TNF-α, and interferon-γ are known to be involved in mediating β-cells death in diabetes mellitus (DM). Thus, protecting from β-cells death in patients with DM may be a useful target in alleviating symptoms of hyperglycemia. Traditional plant-based remedies have been used to treat DM for many centuries and may play a role in protecting β-cell from death. An example of these remedies is Gymnema sylvestre (GS) extract. In this study, we investigated the effect of this plant extract on β-cells apoptosis. Om Santal Adivasi (OSA®) maintained cell membrane integrity in MIN6 cells and mouse islets. Om Santal Adivasi significantly protected MIN6 cells and mouse islets from cytokine-induced apoptosis. In the presence of cytokines, OSA® significantly reduced the expression and activity of caspase-3. The antiapoptotic effect of OSA® as shown by microarray analysis is largely mediated by activating pathways involved in cell survival (mainly casein kinase II pathway) and the free radical scavenger system (specifically superoxide dismutase and catalase). This study indicates that the GS isolate OSA® protects against cytokine-induced apoptosis of β-cells by increasing the expression of cell survival pathways and free radical scavenger system.
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Affiliation(s)
- Altaf Al-Romaiyan
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait
| | - Bo Liu
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, London, UK
| | - Shanta Persaud
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, London, UK
| | - Peter Jones
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, London, UK
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Scutellarin Exerts Hypoglycemic and Renal Protective Effects in db/db Mice via the Nrf2/HO-1 Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1354345. [PMID: 30881587 PMCID: PMC6387728 DOI: 10.1155/2019/1354345] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/08/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022]
Abstract
This study investigated the hypoglycemic and renal protective effects of scutellarin (SCU) in db/db mice and elucidated the underlying mechanisms. The oral administration of metformin hydrochloride (Met) at 120 mg/kg and SCU at 25, 50, and 100 mg/kg over an eight-week period had hypoglycemic effects, demonstrated by decreases in body weight, blood glucose, food and water intake, and glycated hemoglobin activity and by augmented insulin levels and pyruvate kinase activity in the serum of db/db mice. SCU alleviated dyslipidemia by decreasing the levels of triglycerides and total cholesterol and enhancing the levels of high-density lipoprotein cholesterol in the serum of db/db mice. SCU reversed the overexpression of mRNA of renal damage markers (receptor for advanced glycation end products, neutrophil gelatinase-associated lipocalin, and kidney injury molecule 1), macrophage marker CD11b, and T cell marker CD3 in kidney of db/db mice. Pathological examination confirmed that SCU improved the organ structures of hyperglycemia-damaged livers, kidneys, and pancreas islets. Antibody array assay and enzyme-linked immunosorbent assay were combined to screen and analyze the regulatory effects of SCU on inflammatory factors and oxidative enzymes. SCU exerted anti-inflammatory effects by inhibiting the levels of proinflammatory cytokines (glycogen synthase kinase, intercellular adhesion molecule 2, and interleukin 1β and 2) and promoting anti-inflammatory cytokines (interleukin 4). SCU decreased the reactive oxygen species and malondialdehyde concentrations and increased the activity levels of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and catalase) in serum and kidneys. Furthermore, SCU upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which in turn improved heme oxygenase 1 (HO-1), superoxide dismutase 1 and 2, and catalase expression levels in kidneys. The study showed that SCU has at least partial hypoglycemic and renal protective effects in db/db mice, and the mechanism is the modulation of the Nrf2/HO-1 signaling pathway.
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Crèvecoeur I, Vig S, Mathieu C, Overbergh L. Understanding type 1 diabetes through proteomics. Expert Rev Proteomics 2017. [DOI: 10.1080/14789450.2017.1345633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Inne Crèvecoeur
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Saurabh Vig
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Chantal Mathieu
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lut Overbergh
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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Callewaert H, Gysemans C, Cardozo AK, Elsner M, Tiedge M, Eizirik DL, Mathieu C. Cell Loss during Pseudoislet Formation Hampers Profound Improvements in Islet Lentiviral Transduction Efficacy for Transplantation Purposes. Cell Transplant 2017; 16:527-37. [PMID: 17708342 DOI: 10.3727/000000007783464948] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Islet transplantation is a promising treatment in type 1 diabetes, but the need for chronic immunosuppression is a major hurdle to broad applicability. Ex vivo introduction of agents by lentiviral vectors—improving β-cell resistance against immune attack—is an attractive path to pursue. The aim of this study was to investigate whether dissociation of islets to single cells prior to viral infection and reaggregation before transplantation would improve viral transduction efficacy without cytotoxicity. This procedure improved transduction efficacy with a LV-pWPT-CMV-EGFP construct from 11.2 ± 4.1% at MOI 50 in whole islets to 80.0 ± 2.8% at MOI 5. Viability (as measured by Hoechst/PI) and functionality (as measured by glucose challenge) remained high. After transplantation, the transfected pseudoislet aggregates remained EGFP positive for more than 90 days and the expression of EGFP colocalized primarily with the insulin-positive β-cells. No increased vulnerability to immune attack was observed in vitro or in vivo. These data demonstrate that dispersion of islets prior to lentiviral transfection and reaggregation prior to transplantation is a highly efficient way to introduce genes of interest into islets for transplantation purposes in vitro and in vivo, but the amount of β-cells needed for normalization of glycemia was more than eightfold higher when using dispersed cell aggregates versus unmanipulated islets. The high price to pay to reach stable and strong transgene expression in islet cells is certainly an important cell loss.
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Affiliation(s)
- H Callewaert
- Laboratory of Experimental Medicine and Endocrinology (LEGENDO), UZ Gasthuisberg O&N, Katholieke Universiteit Leuven, Leuven, Belgium
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Molecular mechanisms of ROS production and oxidative stress in diabetes. Biochem J 2017; 473:4527-4550. [PMID: 27941030 DOI: 10.1042/bcj20160503c] [Citation(s) in RCA: 528] [Impact Index Per Article: 75.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022]
Abstract
Oxidative stress and chronic inflammation are known to be associated with the development of metabolic diseases, including diabetes. Oxidative stress, an imbalance between oxidative and antioxidative systems of cells and tissues, is a result of over production of oxidative-free radicals and associated reactive oxygen species (ROS). One outcome of excessive levels of ROS is the modification of the structure and function of cellular proteins and lipids, leading to cellular dysfunction including impaired energy metabolism, altered cell signalling and cell cycle control, impaired cell transport mechanisms and overall dysfunctional biological activity, immune activation and inflammation. Nutritional stress, such as that caused by excess high-fat and/or carbohydrate diets, promotes oxidative stress as evident by increased lipid peroxidation products, protein carbonylation and decreased antioxidant status. In obesity, chronic oxidative stress and associated inflammation are the underlying factors that lead to the development of pathologies such as insulin resistance, dysregulated pathways of metabolism, diabetes and cardiovascular disease through impaired signalling and metabolism resulting in dysfunction to insulin secretion, insulin action and immune responses. However, exercise may counter excessive levels of oxidative stress and thus improve metabolic and inflammatory outcomes. In the present article, we review the cellular and molecular origins and significance of ROS production, the molecular targets and responses describing how oxidative stress affects cell function including mechanisms of insulin secretion and action, from the point of view of possible application of novel diabetic therapies based on redox regulation.
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Chau A, Markley J, Juang J, Tsen L. Cytokines in the perinatal period – Part II. Int J Obstet Anesth 2016; 26:48-58. [DOI: 10.1016/j.ijoa.2015.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/28/2015] [Accepted: 12/22/2015] [Indexed: 11/29/2022]
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Tennant BR, Hurley P, Dhillon J, Gill A, Whiting C, Hoffman BG. The TrxG Complex Mediates Cytokine Induced De Novo Enhancer Formation in Islets. PLoS One 2015; 10:e0141470. [PMID: 26505193 PMCID: PMC4623983 DOI: 10.1371/journal.pone.0141470] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 10/08/2015] [Indexed: 01/06/2023] Open
Abstract
To better understand how β-cells respond to proinflammatory cytokines we mapped the locations of histone 3 lysine 4 monomethylation (H3K4me1), a post-translational histone modification enriched at active and poised cis-regulatory regions, in IFNγ, Il-1β, and TNFα treated pancreatic islets. We identified 96,721 putative cis-regulatory loci, of which 3,590 were generated de novo, 3,204 had increased H3K4me1, and 5,354 had decreased H3K4me1 in IFNγ, Il-1β, and TNFα exposed islets. Roughly 10% of the de novo and increased regions were enriched for the repressive histone modification histone 3 lysine 27 trimethylation (H3K27me3) in untreated cells, and these were frequently associated with chemokine genes. We show that IFNγ, Il-1β, and TNFα exposure overcomes this repression and induces chemokine gene activation in as little as three hours, and that this expression persists for days in absence of continued IFNγ, Il-1β, and TNFα exposure. We implicate trithorax group (TrxG) complexes as likely players in the conversion of these repressed loci to an active state. To block the activity of these complexes, we suppressed Wdr5, a core component of the TrxG complexes, and used the H3K27me3 demethylase inhibitor GSK-J4. We show that GSK-J4 is particularly effective in blunting IFNγ, Il-1β, and TNFα-induced chemokine gene expression in β-cells; however, it induced significant islet-cell apoptosis and β-cell dysfunction. Wdr5 suppression also reduced IFNγ, Il-1β, and TNFα induced chemokine gene expression in β-cells without affecting islet-cell survival or β-cell function after 48hrs, but did begin to increase islet-cell apoptosis and β-cell dysfunction after four days of treatment. Taken together these data suggest that the TrxG complex is potentially a viable target for preventing cytokine induced chemokine gene expression in β-cells.
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Affiliation(s)
- Bryan R. Tennant
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
| | - Peter Hurley
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
| | - Jasmine Dhillon
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
| | - Amol Gill
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
| | - Cheryl Whiting
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
| | - Brad G. Hoffman
- Child and Family Research Institute, British Columbia Children’s Hospital and Sunny Hill Health Centre, 950 W28th Avenue, Vancouver, British Columbia, Canada
- Department of Surgery, University of British Columbia, Vancouver, B.C., Canada
- * E-mail:
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Rondas D, Gudmundsdottir V, D'Hertog W, Crèvecoeur I, Waelkens E, Brunak S, Mathieu C, Overbergh L. A proteomic study of the regulatory role for STAT-1 in cytokine-induced beta-cell death. Proteomics Clin Appl 2015; 9:938-52. [DOI: 10.1002/prca.201400124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 01/19/2015] [Accepted: 02/18/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Dieter Rondas
- Division of Clinical and Experimental Endocrinology; KU Leuven Leuven Belgium
| | - Valborg Gudmundsdottir
- Department of Systems Biology; Center for Biological Sequence Analysis; Technical University of Denmark; Lyngby Denmark
| | - Wannes D'Hertog
- Division of Clinical and Experimental Endocrinology; KU Leuven Leuven Belgium
| | - Inne Crèvecoeur
- Division of Clinical and Experimental Endocrinology; KU Leuven Leuven Belgium
| | - Etienne Waelkens
- Laboratory of Protein Phosphorylation and Proteomics; KU Leuven Leuven Belgium
- SyBioMa; KU Leuven Leuven Belgium
| | - Soren Brunak
- Department of Systems Biology; Center for Biological Sequence Analysis; Technical University of Denmark; Lyngby Denmark
- The Novo Nordisk Foundation Center for Protein Research; University of Copenhagen; Copenhagen Denmark
| | - Chantal Mathieu
- Division of Clinical and Experimental Endocrinology; KU Leuven Leuven Belgium
| | - Lut Overbergh
- Division of Clinical and Experimental Endocrinology; KU Leuven Leuven Belgium
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Crèvecoeur I, Rondas D, Mathieu C, Overbergh L. The beta-cell in type 1 diabetes: What have we learned from proteomic studies? Proteomics Clin Appl 2015; 9:755-66. [PMID: 25641783 DOI: 10.1002/prca.201400135] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/05/2014] [Accepted: 01/27/2015] [Indexed: 01/03/2023]
Abstract
Pancreatic beta-cells have a crucial role in the regulation of blood glucose homeostasis by the production and secretion of insulin. In type 1 diabetes (T1D), an autoimmune reaction against the beta-cells together with the presence of inflammatory cytokines and ROS in the islets leads to beta-cell dysfunction and death. This review gives an overview of proteomic studies that lead to better understanding of beta-cell functioning in T1D. Protein profiling of isolated islets and beta-cell lines in health and T1D contributed to the unraveling of pathways involved in cytokine-induced cell death. In addition, by studying the serological proteome of T1D patients, new biomarkers and beta-cell autoantigens were discovered, which may improve screening tests and follow-up of T1D development. Interestingly, an important role for PTMs was demonstrated in the generation of beta-cell autoantigens. To conclude, proteomic techniques are of indispensable value to improve the knowledge on beta-cell function in T1D and the search toward therapeutic targets.
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Affiliation(s)
- Inne Crèvecoeur
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Dieter Rondas
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Chantal Mathieu
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lut Overbergh
- Laboratory for Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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Vasu S, Moffett RC, McClenaghan NH, Flatt PR. Responses of GLP1-secreting L-cells to cytotoxicity resemble pancreatic β-cells but not α-cells. J Mol Endocrinol 2015; 54:91-104. [PMID: 25527608 DOI: 10.1530/jme-14-0214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Little is known about responses of intestinal L-cells to chemical or cytokine-mediated attack and how these compare with pancreatic β- or α-cells. Administration of streptozotocin to mice induced severe diabetes, islet lymphocytic infiltration, increased α-cell proliferation and decreased numbers of β- and L-cells. In vitro, streptozotocin and cytokines reduced cell viability with higher lethal dose 50 values for α-TC1 cells. mRNA expression of Glut2 was lower and Cat was greater in GLUTag and α-TC1 cells compared with MIN6 cells. Cytotoxins affected the transcription of genes involved in secretion in GLUTag and MIN6 cells. They are also involved in upregulation of antioxidant defence enzymes, transcription of NfκB and Nos2, and production of nitrite in all cell types. Cytotoxin-induced DNA damage and apoptosis were apparent in all cells, but α-TC1 cells were less severely affected. Thus, responses of GLP1-secreting L-cells to cytotoxicity resemble β-cells, whereas α-cells are resistant due to differences in the expression of genes involved in cytotoxicity or antioxidant defence.
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Affiliation(s)
- Srividya Vasu
- SAAD Centre for Pharmacy and DiabetesUniversity of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK
| | - R Charlotte Moffett
- SAAD Centre for Pharmacy and DiabetesUniversity of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK
| | - Neville H McClenaghan
- SAAD Centre for Pharmacy and DiabetesUniversity of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK
| | - Peter R Flatt
- SAAD Centre for Pharmacy and DiabetesUniversity of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland, UK
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Mechanisms of toxicity by proinflammatory cytokines in a novel human pancreatic beta cell line, 1.1B4. Biochim Biophys Acta Gen Subj 2013; 1840:136-45. [PMID: 24005237 DOI: 10.1016/j.bbagen.2013.08.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 08/07/2013] [Accepted: 08/26/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND Molecular mechanisms of toxicity and cell damage were investigated in the novel human beta cell line, 1.1B4, after exposure to proinflammatory cytokines - IL-1β, IFN-γ, TNF-α. METHODS MTT assay, insulin radioimmunoassay, glucokinase assay, real time reverse transcription PCR, western blotting, nitrite assay, caspase assay and comet assay were used to investigate mechanisms of cytokine toxicity. RESULTS Viability of 1.1B4 cells decreased after 18h cytokine exposure. Cytokines significantly reduced cellular insulin content and impaired insulin secretion induced by glucose, alanine, KCl, elevated Ca(2+), GLP-1 or forskolin. Glucokinase enzyme activity, regulation of intracellular Ca(2+) and PDX1 protein expression were significantly reduced by cytokines. mRNA expression of genes involved in secretory function - INS, GCK, PCSK2 and GJA1 was downregulated in cytokine treated 1.1B4 cells. Upregulation of transcription of genes involved in antioxidant defence - SOD2 and GPX1 was observed, suggesting involvement of oxidative stress. Cytokines also upregulated transcriptions of NFKB1 and STAT1, which was accompanied by a significant increase in NOS2 transcription and accumulation of nitrite in culture medium, implicating nitrosative stress. Oxidative and nitrosative stresses induced apoptosis was evident from increased % tail DNA, DNA fragmentation, caspase 3/7 activity, apoptotic cells and lower BCL2 protein expression. CONCLUSIONS This study delineates molecular mechanisms of cytokine toxicity in 1.1B4 cells, which agree with earlier observations using human islets and rodent beta cells. GENERAL SIGNIFICANCE This study emphasizes the potential usefulness of this cell line as a human beta cell model for research investigating autoimmune destruction of pancreatic beta cells.
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GLIS3, a susceptibility gene for type 1 and type 2 diabetes, modulates pancreatic beta cell apoptosis via regulation of a splice variant of the BH3-only protein Bim. PLoS Genet 2013; 9:e1003532. [PMID: 23737756 PMCID: PMC3667755 DOI: 10.1371/journal.pgen.1003532] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 04/12/2013] [Indexed: 12/19/2022] Open
Abstract
Mutations in human Gli-similar (GLIS) 3 protein cause neonatal diabetes. The GLIS3 gene region has also been identified as a susceptibility risk locus for both type 1 and type 2 diabetes. GLIS3 plays a role in the generation of pancreatic beta cells and in insulin gene expression, but there is no information on the role of this gene on beta cell viability and/or susceptibility to immune- and metabolic-induced stress. GLIS3 knockdown (KD) in INS-1E cells, primary FACS-purified rat beta cells, and human islet cells decreased expression of MafA, Ins2, and Glut2 and inhibited glucose oxidation and insulin secretion, confirming the role of this transcription factor for the beta cell differentiated phenotype. GLIS3 KD increased beta cell apoptosis basally and sensitized the cells to death induced by pro-inflammatory cytokines (interleukin 1β + interferon-γ) or palmitate, agents that may contribute to beta cell loss in respectively type 1 and 2 diabetes. The increased cell death was due to activation of the intrinsic (mitochondrial) pathway of apoptosis, as indicated by cytochrome c release to the cytosol, Bax translocation to the mitochondria and activation of caspases 9 and 3. Analysis of the pathways implicated in beta cell apoptosis following GLIS3 KD indicated modulation of alternative splicing of the pro-apoptotic BH3-only protein Bim, favouring expression of the pro-death variant BimS via inhibition of the splicing factor SRp55. KD of Bim abrogated the pro-apoptotic effect of GLIS3 loss of function alone or in combination with cytokines or palmitate. The present data suggest that altered expression of the candidate gene GLIS3 may contribute to both type 1 and 2 type diabetes by favouring beta cell apoptosis. This is mediated by alternative splicing of the pro-apoptotic protein Bim and exacerbated formation of the most pro-apoptotic variant BimS. Pancreatic beta cell dysfunction and death is a central event in the pathogenesis of diabetes. Genome-wide association studies have identified a large number of associations between specific loci and the two main forms of diabetes, namely type 1 and type 2 diabetes, but the mechanisms by which these candidate genes predispose to diabetes remain to be clarified. The GLIS3 gene region has been identified as a susceptibility risk locus for both type 1 and type 2 diabetes—it is actually the only locus showing association with both forms of diabetes and the regulation of blood glucose. We show that decreased expression of GLIS3 may contribute to diabetes by favouring beta cell apoptosis. This is mediated by the mitochondrial pathway of apoptosis, activated via alternative splicing (a process by which exons are joined in multiple ways, leading to the generation of several proteins by a single gene) of the pro-apoptotic protein Bim, which favours formation of the most pro-apoptotic variant. The present data provides the first evidence that a susceptibility gene for diabetes may contribute to disease via regulation of alternative splicing of a pro-apoptotic gene in pancreatic beta cells.
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14
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La Torre D. Immunobiology of beta-cell destruction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 771:194-218. [PMID: 23393680 DOI: 10.1007/978-1-4614-5441-0_16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Type 1 diabetes is a chronic disease characterized by severe insulin deficiency and hyperglycemia, due to autoimmune destruction of pancreatic islets of Langerhans. A susceptible genetic background is necessary, but not sufficient, for the development of the disease. Epidemiological and clinical observations underscore the importance of environmental factors as triggers of type 1 diabetes, currently under investigation. Islet-specific autoantibodies precede clinical onset by months to years and are established tools for risk prediction, yet minor players in the pathogenesis of the disease. Many efforts have been made to elucidate disease-relevant defects in the key immune effectors of islet destruction, from the early failure of specific tolerance to the vicious circle of destructive insulitis. However, the events triggering islet autoimmunity as well as the transition to overt diabetes are still largely unknown, making prevention and treatment strategies still a challenge.
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Affiliation(s)
- Daria La Torre
- Lund University, Clinical Research Center (CRC), Department of Clinical Sciences, Malmö, Sweden.
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15
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Couri CEB, de Oliveira MC, Simões BP. Risks, benefits, and therapeutic potential of hematopoietic stem cell transplantation for autoimmune diabetes. Curr Diab Rep 2012; 12:604-11. [PMID: 22864730 DOI: 10.1007/s11892-012-0309-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 1 diabetes mellitus is a chronic disease that results from the autoimmune response against pancreatic insulin producing β cells. Apart of several insulin regimens, since the decade of 80s various immunomodulatory regimens were tested aiming at blocking some steps of the autoimmune process against β cell mass and at promoting β cell preservation. In the last years, some independent research groups tried to cure type 1 diabetes with an "immunologic reset" provided by autologous hematopoietic stem cell transplantation in newly diagnosed patients, and the majority of patients became free form insulin with increasing levels of C-peptide along the time. In this review, we discuss the biology of hematopoietic stem cells and the possible advantages and disadvantages related to the high dose immunosuppression followed by autologous hematopoietic stem cell transplantation.
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Affiliation(s)
- Carlos Eduardo Barra Couri
- Bone Marrow Transplantation Unit of the School of Medicine of Ribeirão Preto, Av. Bandeirantes, 3900 (6° andar), Ribeirão Preto, SP, Brazil, CEP 14048-900.
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Li F, Mahato RI. RNA interference for improving the outcome of islet transplantation. Adv Drug Deliv Rev 2011; 63:47-68. [PMID: 21156190 DOI: 10.1016/j.addr.2010.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/19/2010] [Accepted: 11/25/2010] [Indexed: 01/06/2023]
Abstract
Islet transplantation has the potential to cure type 1 diabetes. Despite recent therapeutic success, it is still not common because a large number of transplanted islets get damaged by multiple challenges including instant blood mediated inflammatory reaction, hypoxia/reperfusion injury, inflammatory cytokines, and immune rejection. RNA interference (RNAi) is a novel strategy to selectively degrade target mRNA. The use of RNAi technologies to downregulate the expression of harmful genes has the potential to improve the outcome of islet transplantation. The aim of this review is to gain a thorough understanding of biological obstacles to islet transplantation and discuss how to overcome these barriers using different RNAi technologies. This eventually will help improve islet survival and function post transplantation. Chemically synthesized small interferring RNA (siRNA), vector based short hairpin RNA (shRNA), and their critical design elements (such as sequences, promoters, and backbone) are discussed. The application of combinatorial RNAi in islet transplantation is also discussed. Last but not the least, several delivery strategies for enhanced gene silencing are discussed, including chemical modification of siRNA, complex formation, bioconjugation, and viral vectors.
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Affiliation(s)
- Feng Li
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38103, USA
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17
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Chou DHC, Bodycombe NE, Carrinski HA, Lewis TA, Clemons PA, Schreiber SL, Wagner BK. Small-Molecule Suppressors of Cytokine-Induced beta-Cell Apoptosis. ACS Chem Biol 2010; 5:729-34. [PMID: 20550176 DOI: 10.1021/cb100129d] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pancreatic beta-cell apoptosis is a critical event during the development of type-1 diabetes. The identification of small molecules capable of preventing cytokine-induced apoptosis could lead to avenues for therapeutic intervention. We developed a set of phenotypic cell-based assays designed to identify such small-molecule suppressors. Rat INS-1E cells were simultaneously treated with a cocktail of inflammatory cytokines and a collection of 2,240 diverse small molecules and screened using an assay for cellular ATP levels. Forty-nine top-scoring compounds included glucocorticoids, several pyrazole derivatives, and known inhibitors of glycogen synthase kinase-3beta. Two compounds were able to increase cellular ATP levels, reduce caspase-3 activity and nitrite production, and increase glucose-stimulated insulin secretion in the presence of cytokines. These results indicate that small molecules identified by this screening approach may protect beta cells from autoimmune attack and may be good candidates for therapeutic intervention in early stages of type-1 diabetes.
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Affiliation(s)
- Danny Hung-Chieh Chou
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Nicole E. Bodycombe
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
| | - Hyman A. Carrinski
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
| | - Timothy A. Lewis
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
| | - Paul A. Clemons
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
| | - Stuart L. Schreiber
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Bridget K. Wagner
- Chemical Biology Program, Broad Institute, 7 Cambridge Center, Cambridge, Massachusetts 02142
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18
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Carey C, Purohit S, She JX. Advances and challenges in biomarker development for type 1 diabetes prediction and prevention using omic technologies. ACTA ACUST UNITED AC 2010; 4:397-410. [PMID: 20885991 DOI: 10.1517/17530059.2010.508492] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD: Biomarkers are essential for the identification of high risk children as well as monitoring of prevention outcomes for type 1 diabetes (T1D). AREAS COVERED IN THIS REVIEW: This review discusses progress, opportunities and challenges in biomarker discovery and validation using high throughput genomic, transcriptomic and proteomic technologies. The authors also suggest potential solutions to deal with the current challenges. WHAT THE READER WILL GAIN: Readers will gain an overview of the current status on T1D biomarkers, an integrated review of three omic technologies, their applications and limitations for biomarker discovery and validation, and a critical discussion of the major issues encountered in biomarker development. TAKE HOME MESSAGE: Better biomarkers are still urgently needed for T1D prediction and prevention. The high throughput omic technologies offer great opportunities but also face significant challenges that have to be solved before their potential for biomarker development is fully realized.
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Affiliation(s)
- Colleen Carey
- Medical College of Georgia, Center for Biotechnology and Genomic Medicine, 1120 15th St., Augusta, 30912, USA
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19
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La Torre D, Lernmark A. Immunology of beta-cell destruction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:537-83. [PMID: 20217514 DOI: 10.1007/978-90-481-3271-3_24] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The pancreatic islet beta-cells are the target for an autoimmune process that eventually results in an inability to control blood glucose due to the lack of insulin. The different steps that eventually lead to the complete loss of the beta-cells are reviewed to include the very first step of a triggering event that initiates the development of beta-cell autoimmunity to the last step of appearance of islet-cell autoantibodies, which may mark that insulitis is about to form. The observations that the initial beta-cell destruction by virus or other environmental factors triggers islet autoimmunity not in the islets but in the draining pancreatic lymph nodes are reviewed along with possible basic mechanisms of loss of tolerance to islet autoantigens. Once islet autoimmunity is established the question is how beta-cells are progressively killed by autoreactive lymphocytes which eventually results in chronic insulitis. Many of these series of events have been dissected in spontaneously diabetic mice or rats, but controlled clinical trials have shown that rodent observations are not always translated into mechanisms in humans. Attempts are therefore needed to clarify the step 1 triggering mechanisms and the step to chronic autoimmune insulitis to develop evidence-based treatment approaches to prevent type 1 diabetes.
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Affiliation(s)
- Daria La Torre
- Lund University, CRC, Department of Clinical Sciences, University Hospital MAS, SE-205 02, Malmö, Sweden.
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20
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Sarkar SA, Kutlu B, Velmurugan K, Kizaka-Kondoh S, Lee CE, Wong R, Valentine A, Davidson HW, Hutton JC, Pugazhenthi S. Cytokine-mediated induction of anti-apoptotic genes that are linked to nuclear factor kappa-B (NF-kappaB) signalling in human islets and in a mouse beta cell line. Diabetologia 2009; 52:1092-101. [PMID: 19343319 DOI: 10.1007/s00125-009-1331-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 02/13/2009] [Indexed: 12/23/2022]
Abstract
AIMS/HYPOTHESIS The destruction of pancreatic beta cells leading to type 1 diabetes in humans is thought to occur mainly through apoptosis and necrosis induced by activated macrophages and T cells, and in which secreted cytokines play a significant role. The transcription factor nuclear factor kappa-B (NF-kappaB) plays an important role in mediating the apoptotic action of cytokines in beta cells. We therefore sought to determine the changes in expression of genes modulated by NF-kappaB in human islets exposed to a combination of IL1beta, TNF-alpha and IFN-gamma. METHODS Microarray and gene set enrichment analysis were performed to investigate the global response of gene expression and pathways modulated in cultured human islets exposed to cytokines. Validation of a panel of NF-kappaB-regulated genes was performed by quantitative RT-PCR. The mechanism of induction of BIRC3 by cytokines was examined by transient transfection of BIRC3 promoter constructs linked to a luciferase gene in MIN6 cells, a mouse beta cell line. RESULTS Enrichment of several metabolic and signalling pathways was observed in cytokine-treated human islets. In addition to the upregulation of known pro-apoptotic genes, a number of anti-apoptotic genes including BIRC3, BCL2A1, TNFAIP3, CFLAR and TRAF1 were induced by cytokines through NF-kappaB. Significant synergy between the cytokines was observed in NF-kappaB-mediated induction of the promoter of BIRC3 in MIN6 cells. CONCLUSIONS/INTERPRETATION These findings suggest that, via NF-kappaB activation, cytokines induce a concurrent anti-apoptotic pathway that may be critical for preserving islet integrity and viability during the progression of insulitis in type 1 diabetes.
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Affiliation(s)
- S A Sarkar
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, CO 80045, USA
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21
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Cha-Molstad H, Saxena G, Chen J, Shalev A. Glucose-stimulated expression of Txnip is mediated by carbohydrate response element-binding protein, p300, and histone H4 acetylation in pancreatic beta cells. J Biol Chem 2009; 284:16898-16905. [PMID: 19411249 DOI: 10.1074/jbc.m109.010504] [Citation(s) in RCA: 174] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recently, we identified Txnip (thioredoxin-interacting protein) as a mediator of glucotoxic beta cell death and discovered that lack of Txnip protects against streptozotocin- and obesity-induced diabetes by preventing beta cell apoptosis and preserving endogenous beta cell mass. Txnip has therefore become an attractive target for diabetes therapy, but although we have found that txnip transcription is highly induced by glucose through a unique carbohydrate response element, the factors controlling this effect have remained unknown. Using transient transfection experiments, we now show that overexpression of the carbohydrate response element-binding protein (ChREBP) transactivates the txnip promoter, whereas ChREBP knockdown by small interfering RNA completely blunts glucose-induced txnip transcription. Moreover, chromatin immunoprecipitation demonstrated that glucose leads to a dose- and time-dependent recruitment of ChREBP to the txnip promoter in vivo in INS-1 beta cells as well as human islets. Furthermore, we found that the co-activator and histone acetyltransferase p300 co-immunoprecipitates with ChREBP and also binds to the txnip promoter in response to glucose. Interestingly, this is associated with specific acetylation of histone H4 and recruitment of RNA polymerase II as measured by chromatin immunoprecipitation. Thus, with this study we have identified ChREBP as the transcription factor that mediates glucose-induced txnip expression in human islets and INS-1 beta cells and have characterized the chromatin modification associated with glucose-induced txnip transcription. In addition, the results reveal for the first time that ChREBP interacts with p300. This may explain how ChREBP induces H4 acetylation and sheds new light on glucose-mediated regulation of chromatin structure and transcription.
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Affiliation(s)
- Hyunjoo Cha-Molstad
- From the Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792; William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Geetu Saxena
- From the Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792; William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Junqin Chen
- From the Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792; William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Anath Shalev
- From the Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792; William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705.
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22
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Abstract
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease with a strong inflammatory component. The latest studies indicate that innate immunity and inflammatory mediators have a much broader role in T1DM than initially assumed. Inflammation might contribute to early induction and amplification of the immune assault against pancreatic beta cells and, at later stages, to the stabilization and maintenance of insulitis. Inflammatory mediators probably contribute to the suppression of beta-cell function and subsequent apoptosis; they may also inhibit or stimulate beta-cell regeneration and might cause peripheral insulin resistance. The different effects of inflammation take place in different phases of the course of T1DM, and should be considered in the context of a 'dialog' between invading immune cells and the target beta cells. This dialog is mediated both by cytokines and chemokines that are released by beta cells and immune cells, and by putative, immunogenic signals that are delivered by dying beta cells. In this Review, we divided the role of inflammation in T1DM into three arbitrary stages: induction, amplification and maintenance or resolution of insulitis. These stages, and their progression or resolution, might depend on a patient's genetic background, which contributes to disease heterogeneity.
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Affiliation(s)
- Décio L Eizirik
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, 808 Route de Lennik, Brussels,Belgium.
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23
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Kutlu B, Burdick D, Baxter D, Rasschaert J, Flamez D, Eizirik DL, Welsh N, Goodman N, Hood L. Detailed transcriptome atlas of the pancreatic beta cell. BMC Med Genomics 2009; 2:3. [PMID: 19146692 PMCID: PMC2635377 DOI: 10.1186/1755-8794-2-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 01/15/2009] [Indexed: 01/21/2023] Open
Abstract
Background Gene expression patterns provide a detailed view of cellular functions. Comparison of profiles in disease vs normal conditions provides insights into the processes underlying disease progression. However, availability and integration of public gene expression datasets remains a major challenge. The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing beta cell gene expression, the Beta Cell Gene Atlas (BCGA). Methods We performed Massively Parallel Signature Sequencing (MPSS) analysis of human pancreatic islet samples and microarray analyses of purified rat beta cells, alpha cells and INS-1 cells, and compared the information with available array data in the literature. Results MPSS analysis detected around 7600 mRNA transcripts, of which around a third were of low abundance. We identified 2000 and 1400 transcripts that are enriched/depleted in beta cells compared to alpha cells and INS-1 cells, respectively. Microarray analysis identified around 200 transcription factors that are differentially expressed in either beta or alpha cells. We reanalyzed publicly available gene expression data and integrated these results with the new data from this study to build the BCGA. The BCGA contains basal (untreated conditions) gene expression level estimates in beta cells as well as in different cell types in human, rat and mouse pancreas. Hierarchical clustering of expression profile estimates classify cell types based on species while beta cells were clustered together. Conclusion Our gene atlas is a valuable source for detailed information on the gene expression distribution in beta cells and pancreatic islets along with insulin producing cell lines. The BCGA tool, as well as the data and code used to generate the Atlas are available at the T1Dbase website (T1DBase.org).
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Affiliation(s)
- Burak Kutlu
- Institute for Systems Biology, Seattle, WA, USA.
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24
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Use of a systems biology approach to understand pancreatic beta-cell death in Type 1 diabetes. Biochem Soc Trans 2008; 36:321-7. [PMID: 18481950 DOI: 10.1042/bst0360321] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Accumulating evidence indicates that beta-cells die by apoptosis in T1DM (Type 1 diabetes mellitus). Apoptosis is an active gene-directed process, and recent observations suggest that beta-cell apoptosis depends on the parallel and/or sequential up- and down-regulation of hundreds of genes controlled by key transcription factors such as NF-kappaB (nuclear factor kappaB) and STAT-1 (signal transducer and activator of transcription 1). Understanding the regulation of these gene networks, and how they modulate beta-cell death and the 'dialogue' between beta-cells and the immune system, will require a systems biology approach to the problem. This will hopefully allow the search for a cure for T1DM to move from a 'trial-and-error' approach to one that is really mechanistically driven.
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25
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Augstein P, Heinke P, Salzsieder E, Grimm R, Giebel J, Salzsieder C, Harrison LC. Dominance of cytokine- over FasL-induced impairment of the mitochondrial transmembrane potential (Deltapsim) in the pancreatic beta-cell line NIT-1. Diab Vasc Dis Res 2008; 5:198-204. [PMID: 18777493 DOI: 10.3132/dvdr.2008.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitochondria of pancreatic beta-cells are potential targets of intrinsic and extrinsic apoptotic pathways in the autoimmune pathogenesis of type 1 diabetes. We aimed to investigate whether cytokine- and FasLigand (FasL)-induced apoptosis is associated with impaired mitochondrial transmembrane potential (Deltapsim) in the pancreatic beta-cell line NIT-1. NIT-1 cells were exposed to the interleukin-1beta/interferon-gamma (IL-1beta/IFN-gamma) cytokine combination to induce apoptosis in vitro. Low concentrations of cytokines resulted in Deltapsim impairment, and increasing concentrations had only a minor additional effect. Treatment with the inducible nitric oxide synthase (iNOS) inhibitor Nw-nitro-L-arginine methyl ester hydrochloride (L-NAME) prevented cytokine-mediated Deltapsim impairment, implying that cytokines affect Deltapsim via nitric oxide. The broad-spectrum caspase inhibitor Z-VAD(Ome)-FMK (ZVAD) revealed dichotomic actions. In the presence of ZVAD, cytokine-induced nitrite generation was increased but cell death and Deltapsim impairment were reduced. Deltapsim impairment was also reduced by inhibitors of caspases 1, 6 and 8. Induction of Fas by IL-1beta/IFN-gamma coupled with activation by Super-FasL augmented cytokine-induced cell death. We observed a clear dominance of cytokine- over FasL-induced effects on Deltapsim. Our findings show that IL-1beta/IFN-gamma cytokines have a strong effect to impair Deltaym and prime beta-cells for apoptosis via the intrinsic pathway mediated by iNOS and caspases. Furthermore, at least in NIT-1 cells, the extrinsic FasL/Fas pathway has only a minor additive effect on cytokine-induced Deltapsim impairment.
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Affiliation(s)
- Petra Augstein
- Institute of Diabetes "Gerhardt Katsch" Karlsburg e.V., Karlsburg, Germany.
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26
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Barra Couri CE, Foss-Freitas MC, Foss MC, Voltarelli JC. β-cell regeneration to treat Type 1 diabetes mellitus. Expert Rev Endocrinol Metab 2008; 3:51-60. [PMID: 30743785 DOI: 10.1586/17446651.3.1.51] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Type 1 diabetes mellitus (T1DM) results from the autoimmune destruction of the insulin-producing pancreatic β-cells. The autoimmune response begins years before the presentation of hyperglycemic symptoms. At the time of clinical diagnosis, less than 30% of β-cell mass still remains. The conventional therapeutic option to T1DM is daily insulin injections, which is shown to promote tight glucose control and reduce the majority of chronic diabetic complications. Subgroup analysis of the Diabetes Control and Complication Trial showed another important aspect related to long-term complications of diabetes, that is, patients with initially higher serum levels of C-peptide with sustained levels over the subsequent years suffered less microvascular complications and less hypoglycemic events than those patients with low or undetected C-peptide levels. In face of this, β-cell preservation is another important target in the management of T1DM and its related complications. Along the years, many efforts toward the identification of precursors of β-cells have been made, not only with the aim of understanding the physiology of β-cell preservation, but also as a potential source of β-cell replacement. In this review, we summarize the most important studies related to probable precursor cells implied in the process of regeneration, and the results of various immunomodulatory regimens aiming at blocking autoimmunity against pancreatic β-cells and at promoting β-cell preservation. Finally, we comment on the future perspective related to stem cell therapy in T1DM.
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Affiliation(s)
- Carlos Eduardo Barra Couri
- a Division of Endocrinology, Department of Clinical Medicine, School of Medicine of Ribeirão Preto. University of São Paulo, CEP 14051-140, Ribeirão Preto, Brazil
| | - Maria Cristina Foss-Freitas
- a Division of Endocrinology, Department of Clinical Medicine, School of Medicine of Ribeirão Preto. University of São Paulo, CEP 14051-140, Ribeirão Preto, Brazil
| | - Milton César Foss
- a Division of Endocrinology, Department of Clinical Medicine, School of Medicine of Ribeirão Preto. University of São Paulo, CEP 14051-140, Ribeirão Preto, Brazil
| | - Júlio César Voltarelli
- b Bone Marrow Transplantation Unit, Department of Clinical Medicine, School of Medicine of Ribeirão Preto. University of São Paulo, CEP 14048-900, Ribeirão Preto, Brazil.
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27
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D'Hertog W, Overbergh L, Lage K, Ferreira GB, Maris M, Gysemans C, Flamez D, Cardozo AK, Van den Bergh G, Schoofs L, Arckens L, Moreau Y, Hansen DA, Eizirik DL, Waelkens E, Mathieu C. Proteomics Analysis of Cytokine-induced Dysfunction and Death in Insulin-producing INS-1E Cells. Mol Cell Proteomics 2007; 6:2180-99. [DOI: 10.1074/mcp.m700085-mcp200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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28
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De Paula D, Bentley MVLB, Mahato RI. Effect of iNOS and NF-kappaB gene silencing on beta-cell survival and function. J Drug Target 2007; 15:358-69. [PMID: 17541845 DOI: 10.1080/10611860701349695] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Type I diabetes results from beta-cell death and dysfunction, induced by infiltration of immune cells and local production of inflammatory cytokines. Therefore, we investigated the effect of iNOS and NF-kappaB gene silencing on beta-cell survival and function. METHODS Rat insulinoma INS-1E cells were transfected with chemically synthesized siRNA after complex formation with Lipofectamine 2000. Cells were then treated with a cocktail of inflammatory cytokines (IL-1beta+ TNF-alpha+ IFN-alpha), and glucose stimulated-insulin response and viability were determined. iNOS and NF-kappaB gene expression was assessed at mRNA level by real time RT-PCR. The effect of gene silencing was also correlated with cytokine-induced NO production and apoptosis. RESULTS Transfection of INS-1E cells with siRNAs silenced iNOS and NF-kappaB gene expression and reduced NO production in a sequence-specific manner without causing significant loss of cell viability and function. However, the abrogation of NO production did not prevent INS-1E cells from cytokine-induced apoptosis, suggesting that this event may not be totally dependent on NO production. CONCLUSION The gene silencing approach presented here is capable of attenuating the effects of inflammatory cytokines, such as iNOS expression and NO production and it will help to identify new target genes to improve islet transplantation.
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Affiliation(s)
- Daniel De Paula
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil
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29
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Callewaert HI, Gysemans CA, Ladrière L, D'Hertog W, Hagenbrock J, Overbergh L, Eizirik DL, Mathieu C. Deletion of STAT-1 pancreatic islets protects against streptozotocin-induced diabetes and early graft failure but not against late rejection. Diabetes 2007; 56:2169-73. [PMID: 17473223 DOI: 10.2337/db07-0052] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Exposure of beta-cells to inflammatory cytokines leads to apoptotic cell death through the activation of gene networks under the control of specific transcription factors, such as interferon-gamma-induced signal transducer and activator of transcription (STAT)-1. We previously demonstrated that beta-cells lacking STAT-1 are resistant to cytokine-induced cell death in vitro. The aim of this study was to investigate the effect of STAT-1 elimination on immune-mediated beta-cell destruction in vivo. RESEARCH DESIGN AND METHODS Multiple low-dose streptozotocin (STZ) was given to C57BL/6 mice after syngeneic STAT-1(-/-) or wild-type islet transplantation. STAT-1(-/-) and wild-type islets were also transplanted in alloxan-diabetic BALB/c and spontaneously diabetic nonobese diabetic (NOD) mice. Additionally, mice were treated with interleukin (IL)-1 blockade (IL-1 receptor antagonist [IL-1ra]) and low-dose T-cell suppression (cyclosporine A [CsA]). RESULTS When exposed to multiple low-dose STZ in an immune-competent host, STAT-1(-/-) islets were more resistant to destruction than wild-type islets (28 vs. 100% diabetes incidence, P < or = 0.05). STAT-1 deletion also protected allogeneic islet grafts against primary nonfunction in autoimmune NOD mice (0 vs. 17% using wild-type islets). However, no difference in survival time was observed. Additionally, treating recipients with IL-1ra and CsA prolonged graft survival in chemically diabetic BALB/c mice, whereas no difference was seen between STAT-1(-/-) and C57BL/6 grafts. CONCLUSIONS These data indicate that STAT-1 is a key player in immune-mediated early beta-cell dysfunction and death. When considering the many effector mechanisms contributing to beta-cell death following islet transplantation, multiple combined interventions will be needed for prolongation of beta-cell survival in the autoimmune context of type 1 diabetes.
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Affiliation(s)
- Hanne I Callewaert
- Laboratory of Experimental Medicine and Endocrinology, Campus Gasthuisberg O&N 1, Catholic University of Leuven, Leuven, Belgium
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30
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Wang CY, Podolsky R, She JX. Genetic and functional evidence supporting SUMO4 as a type 1 diabetes susceptibility gene. Ann N Y Acad Sci 2007; 1079:257-67. [PMID: 17130563 DOI: 10.1196/annals.1375.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Genomewide linkage analyses since the early 1990s suggested over 20 genomic intervals that may contain susceptibility genes for type 1 diabetes. However, the identification of the specific genes in these intervals presents a formidable challenge due to a number of difficulties associated with genetic mapping and cloning of genes implicated in complex diseases. One of the difficulties is due to the presence of many weak and different susceptibility genes in different patients and populations, a phenomenon known as genetic heterogeneity. In 2004, we reported the cloning of a novel small ubiquitin-like modifier (SUMO) gene, SUMO4, in the IDDM5 interval on chromosome 6q25, and presented strong genetic and functional evidence suggesting that SUMO4 is a susceptibility gene for type 1 diabetes mellitus (T1DM). In this article, we will summarize genetic association data suggesting that SUMO4 is consistently associated with T1DM in the Asian populations while the association is more heterogeneous in the Caucasian populations. We will also discuss the possible molecular pathways through which sumoylation may regulate T1DM and autoimmunity.
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Affiliation(s)
- Cong-Yi Wang
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912, USA.
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31
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Sarkar SA, Wong R, Hackl SI, Moua O, Gill RG, Wiseman A, Davidson HW, Hutton JC. Induction of indoleamine 2,3-dioxygenase by interferon-gamma in human islets. Diabetes 2007; 56:72-9. [PMID: 17192467 DOI: 10.2337/db06-0617] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO) catalyzes the initial, rate-limiting step of tryptophan (Trp) catabolism along the kynurenine (KYN) pathway, and its induction in cells of the immune system in response to cytokines has been implicated in the regulation of antigen presentation and responses to cell-mediated immune attack. Microarray and quantitative PCR analyses of isolated human islets incubated with interferon (IFN)-gamma for 24 h revealed increased expression of IDO mRNA (>139-fold) and Trp-tRNA synthase (WARS) (>17-fold) along with 975 other transcripts more than threefold, notably the downstream effectors janus kinase (JAK)2, signal transducer and activator of transcription (STAT)1, IFN-gamma regulatory factor-1, and several chemokines (CXCL9/MIG, CXCL10/IP10, CXCL11/1-TAC, CCL2, and CCL5/RANTES) and their receptors. IDO protein expression was upregulated in IFN-gamma-treated islets and accompanied by increased intracellular IDO enzyme activity and the release of KYN into the media. The response to IFN-gamma was countered by interleukin-4 and 1alpha-methyl Trp. Immunohistochemical localization showed IDO to be induced in cells of both endocrine, including pancreatic duodenal homeobox 1-positive beta-cells, and nonendocrine origin. We postulate that in the short term, IDO activation may protect islets from cytotoxic damage, although chronic exposure to various Trp metabolites could equally lead to beta-cell attrition.
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Affiliation(s)
- Suparna A Sarkar
- Barbara Davis Center for Childhood Diabetes, University of Colorado at Denver and Health Sciences Center, 1775 Ursula St., Mail Stop B-140, Aurora, CO 80045-6511, USA
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Karlsen AE, Størling ZM, Sparre T, Larsen MR, Mahmood A, Størling J, Roepstorff P, Wrzesinski K, Larsen PM, Fey S, Nielsen K, Heding P, Ricordi C, Johannesen J, Kristiansen OP, Christensen UB, Kockum I, Luthman H, Nerup J, Pociot F. Immune-mediated β-cell destruction in vitro and in vivo—A pivotal role for galectin-3. Biochem Biophys Res Commun 2006; 344:406-15. [PMID: 16600178 DOI: 10.1016/j.bbrc.2006.03.105] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 03/10/2006] [Indexed: 12/30/2022]
Abstract
Pro-apoptotic cytokines are toxic to the pancreatic beta-cells and have been associated with the pathogenesis of Type 1 diabetes (T1D). Proteome analysis of IL-1beta exposed isolated rat islets identified galectin-3 (gal-3) as the most up-regulated protein. Here analysis of human and rat islets and insulinoma cells confirmed IL-1beta regulated gal-3 expression of several gal-3 isoforms and a complex in vivo expression profile during diabetes development in rats. Over-expression of gal-3 protected beta-cells against IL-1beta toxicity, with a complete blockage of JNK phosphorylation, essential for IL-1-mediated apoptosis. Mutation scanning of regulatory and coding regions of the gal-3 gene (LGALS3) identified six polymorphisms. A haplotype comprising three cSNPs showed significantly increased transmission to unaffected offspring in 257 T1D families and replicated in an independent set of 170 T1D families. In summary, combined proteome-transcriptome-genome and functional analyses identify gal-3 as a candidate gene/protein in T1D susceptibility that may prove valuable in future intervention/prevention strategies.
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Ortis F, Cardozo AK, Crispim D, Störling J, Mandrup-Poulsen T, Eizirik DL. Cytokine-induced proapoptotic gene expression in insulin-producing cells is related to rapid, sustained, and nonoscillatory nuclear factor-kappaB activation. Mol Endocrinol 2006; 20:1867-79. [PMID: 16556731 DOI: 10.1210/me.2005-0268] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cytokines, such as IL-1beta and TNF-alpha, contribute to pancreatic beta-cell death in type 1 diabetes mellitus. The transcription factor nuclear factor-kappaB (NF-kappaB) mediates cytokine-induced beta-cell apoptosis. Paradoxically, NF-kappaB has mostly antiapoptotic effects in other cell types. The cellular actions of NF-kappaB depend on the cell type, the nature and duration of the stimulus, the periodicity, and the degree of activity of the particular dimers involved. To clarify the reasons behind the proapoptotic effects of NF-kappaB in pancreatic beta-cells, we compared the pattern of cytokine-induced NF-kappaB activation between rat insulin-producing cells (INS-1E cells) and fibroblasts (208F cells). NF-kappaB activation was induced in INS-1E cells and in 208F cells after exposure to cytokines, but apoptosis was induced only in INS-1E cells, with a more pronounced proapoptotic effect of IL-1beta than of TNF-alpha. NF-kappaB activation in IL-1beta-exposed INS-1E cells was earlier and more marked as compared with TNF-alpha-exposed INS-1E cells or IL-1beta-exposed 208F cells. Both cytokines induced a prolonged (up to 48 h) and stable NF-kappaB activation in INS-1E cells, whereas IL-1beta induced an oscillatory NF-kappaB activation in 208F cells. p65/p65 and p65/p50 were the predominant NF-kappaB dimers in IL-1beta-exposed INS-1E cells and 208F cells, respectively. IL-1beta induced a differential usage of cis-elements in the inducible nitric oxide synthase promoter region in the two cell-lines and an increase in ERK1/2 activity in INS-1E cells but not in 208F cells. Cytokine-induced expression of IkappaB isoforms and other NF-kappaB target genes (Fas, MCP-1, and inducible nitric oxide synthase) was severalfold higher in INS-1E cells than in 208F cells. These results suggest that cytokine-induced NF-kappaB activation in insulin-producing cells is more rapid, marked, and sustained than in fibroblasts, which correlates with a more pronounced activation of downstream genes and a proapoptotic outcome.
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Affiliation(s)
- Fernanda Ortis
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
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Haber EP, Procópio J, Carvalho CRO, Carpinelli AR, Newsholme P, Curi R. New Insights into Fatty Acid Modulation of Pancreatic β‐Cell Function. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 248:1-41. [PMID: 16487789 DOI: 10.1016/s0074-7696(06)48001-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Insulin resistance states as found in type 2 diabetes and obesity are frequently associated with hyperlipidemia. Both stimulatory and detrimental effects of free fatty acids (FFA) on pancreatic beta cells have long been recognized. Acute exposure of the pancreatic beta cell to both high glucose concentrations and saturated FFA results in a substantial increase of insulin release, whereas a chronic exposure results in desensitization and suppression of secretion. Reduction of plasma FFA levels in fasted rats or humans severely impairs glucose-induced insulin release but palmitate can augment insulin release in the presence of nonstimulatory concentrations of glucose. These results imply that changes in physiological plasma levels of FFA are important for regulation of beta-cell function. Although it is widely accepted that fatty acid (FA) metabolism (notably FA synthesis and/or formation of LC-acyl-CoA) is necessary for stimulation of insulin secretion, the key regulatory molecular mechanisms controlling the interplay between glucose and fatty acid metabolism and thus insulin secretion are not well understood but are now described in detail in this review. Indeed the correct control of switching between FA synthesis or oxidation may have critical implications for beta-cell function and integrity both in vivo and in vitro. LC-acyl-CoA (formed from either endogenously synthesized or exogenous FA) controls several aspects of beta-cell function including activation of certain types of PKC, modulation of ion channels, protein acylation, ceramide- and/or NO-mediated apoptosis, and binding to and activating nuclear transcriptional factors. The present review also describes the possible effects of FAs on insulin signaling. We have previously reported that acute exposure of islets to palmitate up-regulates some key components of the intracellular insulin signaling pathway in pancreatic islets. Another aspect considered in this review is the potential source of fatty acids for pancreatic islets in addition to supply in the blood. Lipids can be transferred from leukocytes (macrophages) to pancreatic islets in coculture. This latter process may provide an additional source of FAs that may play a significant role in the regulation of insulin secretion.
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Affiliation(s)
- Esther P Haber
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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35
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Cnop M, Welsh N, Jonas JC, Jörns A, Lenzen S, Eizirik DL. Mechanisms of pancreatic beta-cell death in type 1 and type 2 diabetes: many differences, few similarities. Diabetes 2005; 54 Suppl 2:S97-107. [PMID: 16306347 DOI: 10.2337/diabetes.54.suppl_2.s97] [Citation(s) in RCA: 1100] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 1 and type 2 diabetes are characterized by progressive beta-cell failure. Apoptosis is probably the main form of beta-cell death in both forms of the disease. It has been suggested that the mechanisms leading to nutrient- and cytokine-induced beta-cell death in type 2 and type 1 diabetes, respectively, share the activation of a final common pathway involving interleukin (IL)-1beta, nuclear factor (NF)-kappaB, and Fas. We review herein the similarities and differences between the mechanisms of beta-cell death in type 1 and type 2 diabetes. In the insulitis lesion in type 1 diabetes, invading immune cells produce cytokines, such as IL-1beta, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. IL-1beta and/or TNF-alpha plus IFN-gamma induce beta-cell apoptosis via the activation of beta-cell gene networks under the control of the transcription factors NF-kappaB and STAT-1. NF-kappaB activation leads to production of nitric oxide (NO) and chemokines and depletion of endoplasmic reticulum (ER) calcium. The execution of beta-cell death occurs through activation of mitogen-activated protein kinases, via triggering of ER stress and by the release of mitochondrial death signals. Chronic exposure to elevated levels of glucose and free fatty acids (FFAs) causes beta-cell dysfunction and may induce beta-cell apoptosis in type 2 diabetes. Exposure to high glucose has dual effects, triggering initially "glucose hypersensitization" and later apoptosis, via different mechanisms. High glucose, however, does not induce or activate IL-1beta, NF-kappaB, or inducible nitric oxide synthase in rat or human beta-cells in vitro or in vivo in Psammomys obesus. FFAs may cause beta-cell apoptosis via ER stress, which is NF-kappaB and NO independent. Thus, cytokines and nutrients trigger beta-cell death by fundamentally different mechanisms, namely an NF-kappaB-dependent mechanism that culminates in caspase-3 activation for cytokines and an NF-kappaB-independent mechanism for nutrients. This argues against a unifying hypothesis for the mechanisms of beta-cell death in type 1 and type 2 diabetes and suggests that different approaches will be required to prevent beta-cell death in type 1 and type 2 diabetes.
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Affiliation(s)
- Miriam Cnop
- Laboratory of Experimental Medicine, Faculty of Medicine, Erasmus Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, CP-618, 1070 Brussels, Belgium.
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Andersson AK, Börjesson A, Sandgren J, Sandler S. Cytokines affect PDX-1 expression, insulin and proinsulin secretion from iNOS deficient murine islets. Mol Cell Endocrinol 2005; 240:50-7. [PMID: 16023781 DOI: 10.1016/j.mce.2005.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 05/20/2005] [Accepted: 06/07/2005] [Indexed: 11/17/2022]
Abstract
In rodent islets, exposure to interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) induces expression of inducible nitric oxide synthase (iNOS) and subsequent nitric oxide (NO) formation, which may inhibit islet function. However, cytokines may also induce NO-independent islet suppression. The present aim was to investigate the effect of cytokine exposure to iNOS deficient (iNOS-/-) mouse islets on various islet functions. Islets from iNOS-/- and wt mice exposed to IL-1beta or (IL-1beta + IFN-gamma) for 2-20 h showed different kinetics of glucose-stimulated insulin secretion. In iNOS-/- islets, IL-1beta at high glucose induced a delayed and prolonged stimulation of insulin secretion, and this was followed by an increase in phospholipase D mRNA expression. After 6 and 24 h, proinsulin convertase 1 and 2 (PC1 and PC2) mRNA expression was suppressed and proinsulin secretion increased from wt islets. In iNOS-/- islets, PC1 expression was recovered after 24 h, and there was no difference in proinsulin secretion. PDX-1 mRNA expression was suppressed independent of NO-formation. We conclude that cytokines induce both NO-dependent and NO-independent functional inhibition of murine beta-cells.
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Affiliation(s)
- Annika K Andersson
- Uppsala University, Department of Medical Cell Biology, Biomedicum, Sweden
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37
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Gysemans CA, Ladrière L, Callewaert H, Rasschaert J, Flamez D, Levy DE, Matthys P, Eizirik DL, Mathieu C. Disruption of the gamma-interferon signaling pathway at the level of signal transducer and activator of transcription-1 prevents immune destruction of beta-cells. Diabetes 2005; 54:2396-403. [PMID: 16046307 DOI: 10.2337/diabetes.54.8.2396] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
beta-cells under immune attack are destroyed by the aberrant activation of key intracellular signaling cascades. The aim of the present study was to evaluate the contribution of the signal transducer and activator of transcription (STAT)-1 pathway for beta-cell apoptosis by studying the sensitivity of beta-cells from STAT-1 knockout (-/-) mice to immune-mediated cell death in vitro and in vivo. Whole islets from STAT-1-/- mice were completely resistant to interferon (IFN)-gamma (studied in combination with interleukin [IL]-1beta)-mediated cell death (92 +/- 4% viable cells in STAT-1-/- mice vs. 56 +/- 3% viable cells in wild-type controls, P < or = 0.001) and had preserved insulin release after exposure to IL-1beta and IFN-gamma. Moreover, analysis of cell death in cytokine-exposed purified beta-cells confirmed that protection was due to absence of STAT-1 in the beta-cells themselves. Deficiency of STAT-1 in islets completely prevented cytokine-induced upregulation of IL-15, interferon inducible protein 10, and inducible nitric oxide synthase transcription but did not interfere with monocyte chemoattractant protein 1 and macrophage inflammatory protein 3alpha expression. In vivo, STAT-1-/- mice were partially resistant to development of diabetes after multiple low-dose streptozotocin injections as reflected by mean blood glucose at 12 days after first injection (159 +/- 28 vs. 283 +/- 81 mg/dl in wild-type controls, P < or = 0.05) and diabetes incidence at the end of the follow-up period (39 vs. 73% in wild-type controls, P < or = 0.05). In conclusion, the present results indicate that STAT-1 is a crucial transcription factor in the process of IFN-gamma-mediated beta-cell death and the subsequent development of immune-mediated diabetes.
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Affiliation(s)
- Conny A Gysemans
- LEGENDO, UZ Gasthuisberg O&N, Herestraat 49, B-3000 Leuven, Belgium
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38
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Schisler JC, Jensen PB, Taylor DG, Becker TC, Knop FK, Takekawa S, German M, Weir GC, Lu D, Mirmira RG, Newgard CB. The Nkx6.1 homeodomain transcription factor suppresses glucagon expression and regulates glucose-stimulated insulin secretion in islet beta cells. Proc Natl Acad Sci U S A 2005; 102:7297-302. [PMID: 15883383 PMCID: PMC1091752 DOI: 10.1073/pnas.0502168102] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have previously described rat insulinoma INS-1-derived cell lines with robust or poor glucose-stimulated insulin secretion (GSIS). In the current study, we have further resolved these lines into three classes: class 1, glucose-unresponsive/glucagon-expressing; class 2, glucose-unresponsive/glucagon-negative; and class 3, glucose-responsive/glucagon-negative. The transcription factor Nkx2.2 was expressed with relative abundance of 3.3, 1.0, and 1.0 in class 1, class 2, and class 3 cells, respectively, whereas Nkx6.1 expression had the opposite trend: 1.0, 2.6, and 6.4 in class 1, class 2, and class 3 cells, respectively. In class 1 cells, overexpressed Nkx6.1 suppressed glucagon expression but did not affect the levels of several other prominent beta cell transcription factors. RNA interference (RNAi)-mediated suppression of Nkx6.1 in class 3 cells resulted in a doubling of glucagon mRNA, with no effect on Pdx1 levels, whereas suppression of Pdx1 in class 3 cells caused a 12-fold increase in glucagon transcript levels, demonstrating independent effects of Nkx6.1 and Pdx1 on glucagon expression in beta cell lines. RNAi-mediated suppression of Nkx6.1 expression in class 3 cells also caused a decrease in GSIS from 13.9- to 3.7-fold, whereas suppression of Pdx1 reduced absolute amounts of insulin secretion without affecting fold response. Finally, RNAi-mediated suppression of Nkx6.1 mRNA in primary rat islets was accompanied by a significant decrease in GSIS relative to control cells. In sum, our studies have revealed roles for Nkx6.1 in suppression of glucagon expression and control of GSIS in islet beta cells.
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Affiliation(s)
- Jonathan C Schisler
- Department of Pharmacology, Sarah W. Stedman Nutrition and Metabolism Center, Durham, NC 27704, USA
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Smink LJ, Helton EM, Healy BC, Cavnor CC, Lam AC, Flamez D, Burren OS, Wang Y, Dolman GE, Burdick DB, Everett VH, Glusman G, Laneri D, Rowen L, Schuilenburg H, Walker NM, Mychaleckyj J, Wicker LS, Eizirik DL, Todd JA, Goodman N. T1DBase, a community web-based resource for type 1 diabetes research. Nucleic Acids Res 2005; 33:D544-9. [PMID: 15608258 PMCID: PMC540049 DOI: 10.1093/nar/gki095] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
T1DBase (http://T1DBase.org) is a public website and database that supports the type 1 diabetes (T1D) research community. The site is currently focused on the molecular genetics and biology of T1D susceptibility and pathogenesis. It includes the following datasets: annotated genome sequence for human, rat and mouse; information on genetically identified T1D susceptibility regions in human, rat and mouse, and genetic linkage and association studies pertaining to T1D; descriptions of NOD mouse congenic strains; the Beta Cell Gene Expression Bank, which reports expression levels of genes in beta cells under various conditions, and annotations of gene function in beta cells; data on gene expression in a variety of tissues and organs; and biological pathways from KEGG and BioCarta. Tools on the site include the GBrowse genome browser, site-wide context dependent search, Connect-the-Dots for connecting gene and other identifiers from multiple data sources, Cytoscape for visualizing and analyzing biological networks, and the GESTALT workbench for genome annotation. All data are open access and all software is open source.
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Affiliation(s)
- Luc J Smink
- Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge CB2 2XY, UK.
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Kutlu B, Naamane N, Berthou L, Eizirik DL. New Approaches forin SilicoIdentification of Cytokine-Modified β Cell Gene Networks. Ann N Y Acad Sci 2004; 1037:41-58. [PMID: 15699492 DOI: 10.1196/annals.1337.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Beta cell dysfunction and death in type 1 diabetes mellitus (T1DM) is caused by direct contact with activated macrophages and T lymphocytes and by exposure to soluble mediators secreted by these cells, such as cytokines and nitric oxide. Cytokine-induced apoptosis depends on the expression of pro- and anti-apoptotic genes that remain to be characterized. Using microarray analyses, we identified several transcription factor and "effector" gene networks regulated by interleukin-1beta and/or interferon-gamma in beta cells. This suggests that beta cell fate following exposure to cytokines is a complex and highly regulated process, depending on the duration and severity of perturbation of key gene networks. In order to draw correct conclusions from these massive amounts of data, we need to utilize novel bioinformatics and statistical tools. Thus, we are presently performing in silico analysis for the localization of binding sites for the transcription factor NF-kappaB (previously shown to be pivotal for beta cell apoptosis) in 15 temporally related gene clusters, identified by time-course microarray analysis. In silico analysis is based on a broad range of computational techniques used to detect motifs in a DNA sequence corresponding to the binding site of a transcription factor. These computer-based findings must be validated by use of positive and negative controls, and by "ChIP on chip" analysis. Moreover, new statistical approaches are required to decrease false positive findings. These novel approaches will constitute a "proof of principle" for the integrated use of bioinformatics and functional genomics in the characterization of relevant cytokine-regulated beta cell gene networks leading to beta cell apoptosis in T1DM.
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Affiliation(s)
- Burak Kutlu
- Laboratory of Experimental Medicine, ULB, 808 route de Lennik, B-1070 Brussels, Belgium
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41
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Augstein P, Bahr J, Wachlin G, Heinke P, Berg S, Salzsieder E, Harrison LC. Cytokines activate caspase-3 in insulinoma cells of diabetes-prone NOD mice directly and via upregulation of Fas. J Autoimmun 2004; 23:301-9. [PMID: 15571924 DOI: 10.1016/j.jaut.2004.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2003] [Revised: 09/14/2004] [Accepted: 09/15/2004] [Indexed: 11/26/2022]
Abstract
In type 1 diabetes, autoimmune inflammation of pancreatic islets of Langerhans ('insulitis') results in destruction of insulin-producing beta cells. Cytokines released from islet-infiltrating mononuclear cells are known to be cytotoxic both directly and by upregulating Fas for FasL-induced apoptosis. To investigate the role of caspase-3, a major effector of apoptosis in beta-cell death, we asked whether cytokine- and/or FasL-induced apoptosis was associated with increased activity of caspase-3 in NIT-1 insulinoma cells and islets of autoimmune diabetes-prone NOD mice. Measurement of caspase-3 activity using a fluorogenic cleavage assay was validated in NOD mouse thymocytes undergoing dexamethasone (Dex)-induced apoptosis. For cytokine-induced apoptosis, NIT-1 cells or islets were exposed to IL-1 beta and IFN-gamma for 24 h. Caspase-3-like activity was increased 2.1+/-0.7 and 2.4+/-0.9-fold in lysates of cytokine-treated NIT-1 cells and NOD mouse islets, respectively. However, NIT-1 cells exhibited 2.1% (4.7 pg active caspase-3/microg protein) and islets 0.8% (1.9 pg active caspase-3/microg protein) of the active caspase-3 content observed in Dex-treated thymocytes (225.1 pg active caspase-3/microg protein). After 24 h cytokine-exposure, the percentage of Fas-positive NIT-1 cells increased from 1.4+/-1.1 to 29.7+/-11.6%. Addition of FasL for a further 3 h increased caspase-3-like activity an additional 1.8-fold in cytokine-treated NIT-1 cells. In summary, exposure of NOD mouse insulinoma cells or islets to IL-1 beta and IFN-gamma for 24 h induced caspase-3-like activity that, in the case of insulinoma cells at least, can be further enhanced by interaction of cytokine-induced Fas receptor with FasL. Compared to thymocytes, insulinoma cells and islets from NOD mice were characterised by low basal and cytokine-induced caspase-3 activity.
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Affiliation(s)
- Petra Augstein
- Institute of Diabetes Gerhardt Katsch Karlsburg e.V., Greifswalder Strasse 11e, 17495 Karlsburg, Germany.
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42
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Karlsen AE, Heding PE, Frobøse H, Rønn SG, Kruhøffer M, Orntoft TF, Darville M, Eizirik DL, Pociot F, Nerup J, Mandrup-Poulsen T, Billestrup N. Suppressor of cytokine signalling (SOCS)-3 protects beta cells against IL-1beta-mediated toxicity through inhibition of multiple nuclear factor-kappaB-regulated proapoptotic pathways. Diabetologia 2004; 47:1998-2011. [PMID: 15578154 DOI: 10.1007/s00125-004-1568-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 07/22/2004] [Indexed: 10/26/2022]
Abstract
AIMS/HYPOTHESIS The proinflammatory cytokine IL-1beta induces apoptosis in pancreatic beta cells via pathways dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinase, and protein kinase C. We recently showed suppressor of cytokine signalling (SOCS)-3 to be a natural negative feedback regulator of IL-1beta- and IFN-gamma-mediated signalling in rat islets and beta cell lines, preventing their deleterious effects. However, the mechanisms underlying SOCS-3 inhibition of IL-1beta signalling and prevention against apoptosis remain unknown. METHODS The effect of SOCS-3 expression on the global gene-expression profile following IL-1beta exposure was microarray-analysed using a rat beta cell line (INS-1) with inducible SOCS-3 expression. Subsequently, functional analyses were performed. RESULTS Eighty-two known genes and several expressed sequence tags (ESTs) changed expression level 2.5-fold or more in response to IL-1beta alone. Following 6 h of IL-1beta exposure, 23 transcripts were up-regulated. Of these, several, including all eight transcripts relating to immune/inflammatory response pathways, were suppressed by SOCS-3. Following 24 h of IL-1beta exposure, secondary response genes were detected, affecting metabolism, energy generation, protein synthesis and degradation, growth arrest, and apoptosis. The majority of these changes were prevented by SOCS-3 expression. Multiple IL-1beta-induced NF-kappaB-dependent proapoptotic early response genes were inhibited by SOCS-3 expression, suggesting that SOCS-3 inhibits NF-kappaB-mediated signalling. These observations were experimentally confirmed in functional analyses. CONCLUSIONS/INTERPRETATION This study suggests that there is an unexpected cross-talk between the SOCS/IFN and the IL-1beta pathways of signalling in pancreatic beta cells, which could lead to a novel perspective of blocking two important proapoptotic pathways in pancreatic beta cells by influencing a single signalling molecule, namely SOCS-3.
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Affiliation(s)
- A E Karlsen
- Steno Diabetes Center, Niels Steensensvej 2, 2820 Gentofte, Denmark.
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Maffei A, Liu Z, Witkowski P, Moschella F, Del Pozzo G, Liu E, Herold K, Winchester RJ, Hardy MA, Harris PE. Identification of tissue-restricted transcripts in human islets. Endocrinology 2004; 145:4513-21. [PMID: 15231694 DOI: 10.1210/en.2004-0691] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The purpose of our study was to identify transcripts specific for tissue-restricted, membrane-associated proteins in human islets that, in turn, might serve as markers of healthy or diseased islet cell masses. Using oligonucleotide chips, we obtained gene expression profiles of human islets for comparison with the profiles of exocrine pancreas, liver, and kidney tissue. As periislet presence of type 1 interferon is associated with the development of type 1 diabetes, the expression profile of human islets treated ex vivo with interferon-alpha2beta (IFNalpha2beta) was also determined. A set of genes encoding transmembrane- or membrane-associated proteins with novel islet-restricted expression was resolved by determining the intersection of the islet set with the complement of datasets obtained from other tissues. Under the influence of IFNalpha2beta, the expression levels of transcripts for several of the identified gene products were up- or down-regulated. One of the islet-restricted gene products identified in this study, vesicular monoamine transporter type 2, was shown to bind [3H]dihydrotetrabenazine, a ligand with derivatives suitable for positron emission tomography imaging. We report here the first comparison of gene expression profiles of human islets with other tissues and the identification of a target molecule with possible use in determining islet cell masses.
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Affiliation(s)
- Antonella Maffei
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, National Research Center, Naples, Italy
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44
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Rasschaert J, Liu D, Kutlu B, Cardozo AK, Kruhøffer M, ØRntoft TF, Eizirik DL. Global profiling of double stranded RNA- and IFN-gamma-induced genes in rat pancreatic beta cells. Diabetologia 2003; 46:1641-57. [PMID: 14600816 DOI: 10.1007/s00125-003-1245-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2003] [Revised: 09/11/2003] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS Viral infections and local production of IFN-gamma might contribute to beta-cell dysfunction/death in Type 1 Diabetes. Double stranded RNA (dsRNA) accumulates in the cytosol of viral-infected cells, and exposure of purified rat beta cells to dsRNA (tested in the form of polyinosinic-polycytidylic acid, PIC) in combination with IFN-gamma results in beta-cell dysfunction and apoptosis. To elucidate the molecular mechanisms involved in PIC + IFN-gamma-effects, we determined the global profile of genes modified by these agents in primary rat beta cells. METHODS FACS-purified rat beta cells were cultured for 6 or 24 h in control condition or with IFN-gamma, PIC or a combination of both agents. The gene expression profile was analysed in duplicate by high-density oligonucleotide arrays representing 5000 full-length genes and 3000 EST's. Changes of greater than or equal to 2.5-fold were considered as relevant. RESULTS Following a 6- or 24-h treatment with IFN-gamma, PIC or IFN-gamma and PIC, we observed changes in the expression of 51 to 189 genes. IFN-gamma modified the expression of MHC-related genes, and also of genes involved in beta-cell metabolism, protein processing, cytokines and signal transduction. PIC affected preferentially the expression of genes related to cell adhesion, cytokines and dsRNA signal transduction, transcription factors and MHC. PIC and/or IFN-gamma up-regulated the expression of several chemokines and cytokines that could contribute to mononuclear cell homing and activation during viral infection, while IFN-gamma induced a positive feedback on its own signal transduction. PIC + IFN-gamma inhibited insulin and GLUT-2 expression without modifying pdx-1 mRNA expression. CONCLUSION/INTERPRETATION This study provides the first comprehensive characterization of the molecular responses of primary beta cells to dsRNA + IFN-gamma, two agents that are probably present in the beta cell milieu during the course of virally-induced insulitis and Type 1 Diabetes. Based on these findings, we propose an integrated model for the molecular mechanisms involved in dsRNA + IFN-gamma induced beta-cell dysfunction and death.
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Affiliation(s)
- J Rasschaert
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Route de Lennik, 808, CP 618, 1070, Brussels, Belgium.
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