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Vandenbempt V, Eski SE, Brahma MK, Li A, Negueruela J, Bruggeman Y, Demine S, Xiao P, Cardozo AK, Baeyens N, Martelotto LG, Singh SP, Mariño E, Gysemans C, Gurzov EN. HAMSAB diet ameliorates dysfunctional signaling in pancreatic islets in autoimmune diabetes. iScience 2024; 27:108694. [PMID: 38213620 PMCID: PMC10783594 DOI: 10.1016/j.isci.2023.108694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 10/23/2023] [Accepted: 12/05/2023] [Indexed: 01/13/2024] Open
Abstract
An altered gut microbiota is associated with type 1 diabetes (T1D), affecting the production of short-chain fatty acids (SCFA) and glucose homeostasis. We previously demonstrated that enhancing serum acetate and butyrate using a dietary supplement (HAMSAB) improved glycemia in non-obese diabetic (NOD) mice and patients with established T1D. The effects of SCFA on immune-infiltrated islet cells remain to be clarified. Here, we performed single-cell RNA sequencing on islet cells from NOD mice fed an HAMSAB or control diet. HAMSAB induced a regulatory gene expression profile in pancreas-infiltrated immune cells. Moreover, HAMSAB maintained the expression of β-cell functional genes and decreased cellular stress. HAMSAB-fed mice showed preserved pancreatic endocrine cell identity, evaluated by decreased numbers of poly-hormonal cells. Finally, SCFA increased insulin levels in human β-like cells and improved transplantation outcome in NOD/SCID mice. Our findings support the use of metabolite-based diet as attractive approach to improve glucose control in T1D.
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Affiliation(s)
- Valerie Vandenbempt
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Sema Elif Eski
- IRIBHM, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Manoja K. Brahma
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Ao Li
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Javier Negueruela
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Ylke Bruggeman
- Clinical and Experimental Endocrinology (CEE), Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Campus Gasthuisberg O&N 1, KU Leuven, 3000 Leuven, Belgium
| | - Stéphane Demine
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Peng Xiao
- Inflammatory and Cell Death Signaling in Diabetes group, Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Alessandra K. Cardozo
- Inflammatory and Cell Death Signaling in Diabetes group, Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
| | - Nicolas Baeyens
- Laboratoire de Physiologie et de Pharmacologie, Université Libre de Bruxelles, 1000 Brussels, Belgium
| | - Luciano G. Martelotto
- Single Cell and Spatial-Omics Laboratory, Adelaide Centre of Epigenetics, University of Adelaide, Adelaide, SA 5005, Australia
| | | | - Eliana Mariño
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Melbourne, VIC 3800, Australia
- ImmunoBiota Therapeutics Pty Ltd, Melbourne, VIC 3187, Australia
| | - Conny Gysemans
- Clinical and Experimental Endocrinology (CEE), Department of Chronic Diseases, Metabolism and Ageing (CHROMETA), Campus Gasthuisberg O&N 1, KU Leuven, 3000 Leuven, Belgium
| | - Esteban N. Gurzov
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070 Brussels, Belgium
- WELBIO Department, WEL Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium
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2
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Talamantes S, Lisjak M, Gilglioni EH, Llamoza-Torres CJ, Ramos-Molina B, Gurzov EN. Non-alcoholic fatty liver disease and diabetes mellitus as growing aetiologies of hepatocellular carcinoma. JHEP Rep 2023; 5:100811. [PMID: 37575883 PMCID: PMC10413159 DOI: 10.1016/j.jhepr.2023.100811] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 08/15/2023] Open
Abstract
Obesity-related complications such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) are well-established risk factors for the development of hepatocellular carcinoma (HCC). This review provides insights into the molecular mechanisms that underlie the role of steatosis, hyperinsulinemia and hepatic inflammation in HCC development and progression. We focus on recent findings linking intracellular pathways and transcription factors that can trigger the reprogramming of hepatic cells. In addition, we highlight the role of enzymes in dysregulated metabolic activity and consequent dysfunctional signalling. Finally, we discuss the potential uses and challenges of novel therapeutic strategies to prevent and treat NAFLD/T2D-associated HCC.
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Affiliation(s)
- Stephanie Talamantes
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Route de Lennik 808, Brussels, 1070, Belgium
| | - Michela Lisjak
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Route de Lennik 808, Brussels, 1070, Belgium
| | - Eduardo H. Gilglioni
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Route de Lennik 808, Brussels, 1070, Belgium
| | - Camilo J. Llamoza-Torres
- Department of Hepatology, Virgen de la Arrixaca University Hospital, Murcia, 30120, Spain
- Obesity and Metabolism Laboratory, Biomedical Research Institute of Murcia (IMIB), Murcia, 30120, Spain
| | - Bruno Ramos-Molina
- Obesity and Metabolism Laboratory, Biomedical Research Institute of Murcia (IMIB), Murcia, 30120, Spain
| | - Esteban N. Gurzov
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Route de Lennik 808, Brussels, 1070, Belgium
- Obesity and Metabolism Laboratory, Biomedical Research Institute of Murcia (IMIB), Murcia, 30120, Spain
- WELBIO Department, WEL Research Institute, Avenue Pasteur 6, Wavre, 1300, Belgium
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3
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Takiishi T, Xiao P, Franchimont M, Gilglioni EH, Arroba EN, Gurzov EN, Bertrand MJM, Cardozo AK. Inhibition of RIPK1 kinase does not affect diabetes development: β-Cells survive RIPK1 activation. Mol Metab 2023; 69:101681. [PMID: 36707047 PMCID: PMC9932129 DOI: 10.1016/j.molmet.2023.101681] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/30/2022] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES Type 1 diabetes (T1D) is caused by progressive immune-mediated loss of insulin-producing β-cells. Inflammation is detrimental to β-cell function and survival, moreover, both apoptosis and necrosis have been implicated as mechanisms of β-cell loss in T1D. The receptor interacting serine/threonine protein kinase 1 (RIPK1) promotes inflammation by serving as a scaffold for NF-κB and MAPK activation, or by acting as a kinase that triggers apoptosis or necroptosis. It is unclear whether RIPK1 kinase activity is involved in T1D pathology. In the present study, we investigated if absence of RIPK1 activation would affect the susceptibility to immune-mediated diabetes or diet induced obesity (DIO). METHODS The RIPK1 knockin mouse line carrying a mutation mimicking serine 25 phosphorylation (Ripk1S25D/S25D), which abrogates RIPK1 kinase activity, was utilized to assess the in vivo role of RIPK1 in immune-mediated diabetes or diet induced obesity (DIO). In vitro, β-cell death and RIPK1 kinase activity was analysed in conditions known to induce RIPK1-dependent apoptosis/necroptosis. RESULTS We demonstrate that Ripk1S25D/S25D mice presented normal glucose metabolism and β-cell function. Furthermore, immune-mediated diabetes and DIO were not different between Ripk1S25D/S25D and Ripk1+/+ mice. Despite strong activation of RIPK1 kinase and other necroptosis effectors (RIPK3 and MLKL) by TNF+BV6+zVAD, no cell death was observed in mouse islets nor human β-cells. CONCLUSION Our results contrast recent literature showing that most cell types undergo necroptosis following RIPK1 kinase activation. This peculiarity may reflect an adaptation to the inability of β-cells to proliferate and self-renewal.
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Affiliation(s)
- Tatiana Takiishi
- Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium.
| | - Peng Xiao
- Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium.
| | - Marie Franchimont
- Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium.
| | - Eduardo H. Gilglioni
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Erick N. Arroba
- Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium,Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Esteban N. Gurzov
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium,WELBIO, WEL Research Institute, Avenue Pasteur 6, Wavre, 1300, Belgium
| | - Mathieu JM. Bertrand
- UGent Center for inflammation Research, Ghent, Belgium,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Alessandra K. Cardozo
- Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles (ULB), Brussels, Belgium,Corresponding author. Inflammation and Cell Death Signalling Group, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Route de Lennik, 808, CP 697/02, 1070, Brussels, Belgium.
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4
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Elvira B, Vandenbempt V, Bauzá-Martinez J, Crutzen R, Negueruela J, Ibrahim H, Winder ML, Brahma MK, Vekeriotaite B, Martens PJ, Singh SP, Rossello F, Lybaert P, Otonkoski T, Gysemans C, Wu W, Gurzov EN. PTPN2 Regulates the Interferon Signaling and Endoplasmic Reticulum Stress Response in Pancreatic β-Cells in Autoimmune Diabetes. Diabetes 2022; 71:653-668. [PMID: 35044456 DOI: 10.2337/db21-0443] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022]
Abstract
Type 1 diabetes (T1D) results from autoimmune destruction of β-cells in the pancreas. Protein tyrosine phosphatases (PTPs) are candidate genes for T1D and play a key role in autoimmune disease development and β-cell dysfunction. Here, we assessed the global protein and individual PTP profiles in the pancreas from nonobese mice with early-onset diabetes (NOD) mice treated with an anti-CD3 monoclonal antibody and interleukin-1 receptor antagonist. The treatment reversed hyperglycemia, and we observed enhanced expression of PTPN2, a PTP family member and T1D candidate gene, and endoplasmic reticulum (ER) chaperones in the pancreatic islets. To address the functional role of PTPN2 in β-cells, we generated PTPN2-deficient human stem cell-derived β-like and EndoC-βH1 cells. Mechanistically, we demonstrated that PTPN2 inactivation in β-cells exacerbates type I and type II interferon signaling networks and the potential progression toward autoimmunity. Moreover, we established the capacity of PTPN2 to positively modulate the Ca2+-dependent unfolded protein response and ER stress outcome in β-cells. Adenovirus-induced overexpression of PTPN2 partially protected from ER stress-induced β-cell death. Our results postulate PTPN2 as a key protective factor in β-cells during inflammation and ER stress in autoimmune diabetes.
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Affiliation(s)
- Bernat Elvira
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
| | - Valerie Vandenbempt
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
| | - Julia Bauzá-Martinez
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
- Netherlands Proteomics Centre, Utrecht, the Netherlands
| | - Raphaël Crutzen
- Laboratory of Physiology and Pharmacology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Javier Negueruela
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
| | - Hazem Ibrahim
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Matthew L Winder
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Manoja K Brahma
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
| | - Beata Vekeriotaite
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
| | - Pieter-Jan Martens
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Ageing, Campus Gasthuisberg O&N 1, KU Leuven, Leuven, Belgium
| | | | - Fernando Rossello
- University of Melbourne Centre for Cancer Research, University of Melbourne, Melbourne, Victoria, Australia
| | - Pascale Lybaert
- Laboratory of Physiology and Pharmacology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Conny Gysemans
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Ageing, Campus Gasthuisberg O&N 1, KU Leuven, Leuven, Belgium
| | - Wei Wu
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
- Netherlands Proteomics Centre, Utrecht, the Netherlands
| | - Esteban N Gurzov
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université Libre de Bruxelles, Brussels, Belgium
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5
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Bell KJ, Saad S, Tillett BJ, McGuire HM, Bordbar S, Yap YA, Nguyen LT, Wilkins MR, Corley S, Brodie S, Duong S, Wright CJ, Twigg S, de St Groth BF, Harrison LC, Mackay CR, Gurzov EN, Hamilton-Williams EE, Mariño E. Metabolite-based dietary supplementation in human type 1 diabetes is associated with microbiota and immune modulation. Microbiome 2022; 10:9. [PMID: 35045871 PMCID: PMC8772108 DOI: 10.1186/s40168-021-01193-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/04/2021] [Indexed: 05/04/2023]
Abstract
BACKGROUND Short-chain fatty acids (SCFAs) produced by the gut microbiota have beneficial anti-inflammatory and gut homeostasis effects and prevent type 1 diabetes (T1D) in mice. Reduced SCFA production indicates a loss of beneficial bacteria, commonly associated with chronic autoimmune and inflammatory diseases, including T1D and type 2 diabetes. Here, we addressed whether a metabolite-based dietary supplement has an impact on humans with T1D. We conducted a single-arm pilot-and-feasibility trial with high-amylose maize-resistant starch modified with acetate and butyrate (HAMSAB) to assess safety, while monitoring changes in the gut microbiota in alignment with modulation of the immune system status. RESULTS HAMSAB supplement was administered for 6 weeks with follow-up at 12 weeks in adults with long-standing T1D. Increased concentrations of SCFA acetate, propionate, and butyrate in stools and plasma were in concert with a shift in the composition and function of the gut microbiota. While glucose control and insulin requirements did not change, subjects with the highest SCFA concentrations exhibited the best glycemic control. Bifidobacterium longum, Bifidobacterium adolescentis, and vitamin B7 production correlated with lower HbA1c and basal insulin requirements. Circulating B and T cells developed a more regulatory phenotype post-intervention. CONCLUSION Changes in gut microbiota composition, function, and immune profile following 6 weeks of HAMSAB supplementation were associated with increased SCFAs in stools and plasma. The persistence of these effects suggests that targeting dietary SCFAs may be a mechanism to alter immune profiles, promote immune tolerance, and improve glycemic control for the treatment of T1D. TRIAL REGISTRATION ACTRN12618001391268. Registered 20 August 2018, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375792 Video Abstract.
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Affiliation(s)
- Kirstine J Bell
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Sonia Saad
- Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney Medical School, University of Sydney, St Leonards, Sydney, New South Wales, Australia
| | - Bree J Tillett
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Brisbane, Queensland, 4102, Australia
| | - Helen M McGuire
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Discipline of Pathology, Faculty of Medicine and Health, The University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Ramaciotti Facility for Human Systems Biology, The University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Sara Bordbar
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Melbourne, Victoria, 3800, Australia
| | - Yu Anne Yap
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Melbourne, Victoria, 3800, Australia
| | - Long T Nguyen
- Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney Medical School, University of Sydney, St Leonards, Sydney, New South Wales, Australia
| | - Marc R Wilkins
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Susan Corley
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Shannon Brodie
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Sussan Duong
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Courtney J Wright
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Stephen Twigg
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Barbara Fazekas de St Groth
- Charles Perkins Centre, University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Discipline of Pathology, Faculty of Medicine and Health, The University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
- Ramaciotti Facility for Human Systems Biology, The University of Sydney, Camperdown, Sydney, New South Wales, 2050, Australia
| | - Leonard C Harrison
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria, 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Charles R Mackay
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Melbourne, Victoria, 3800, Australia
| | - Esteban N Gurzov
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, 1070, Brussels, Belgium
| | - Emma E Hamilton-Williams
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Brisbane, Queensland, 4102, Australia.
| | - Eliana Mariño
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Biochemistry, Monash University, Melbourne, Victoria, 3800, Australia.
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6
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Eriksson M, Litwak SA, Yun Y, Stanley WJ, Thorn P, Ahlgren U, Gurzov EN. Insulin-Binding Peptide Probes Provide a Novel Strategy for Pancreatic β-Cell Imaging. Mol Pharm 2021; 18:4428-4436. [PMID: 34649437 DOI: 10.1021/acs.molpharmaceut.1c00616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Type 1 diabetes develops in childhood and adolescence, with peak incidence in the early teenage years. There is an urgent need for an accurate method to detect insulin-producing β-cells in patients that is not affected by alterations in β-cell function. As part of our research program to design specific probes to measure β-cell mass, we recently developed a novel insulin-binding peptide probe (IBPP) for the detection of β-cells in vivo. Here, we applied our innovative method to show specific labeling of this IBPP to human and mouse fixed β-cells in pancreatic islets. Importantly, we showed staining of human and mouse islets in culture without any negative functional or cell viability impact. Moreover, the IBPP-stained mouse islets after tail vein injection in vivo, albeit with batch differences in staining efficiency. In conclusion, we provide evidence showing that the IBPP can be used for future accurate detection of β-cell mass in a variety of preclinical models of diabetes.
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Affiliation(s)
- Maria Eriksson
- Umeå Centre for Molecular Medicine, Umeå University, Johan Bures väg 12, Umeå 901 87, Sweden
| | - Sara A Litwak
- St Vincent's Institute of Medical Research, 9 Princes Street, Melbourne 3065, Australia
| | - Yan Yun
- Charles Perkins Centre, Discipline of Physiology, School of Medical Sciences, University of Sydney, Johns Hopkins Dr, Sydney 2006, Australia
| | - William J Stanley
- St Vincent's Institute of Medical Research, 9 Princes Street, Melbourne 3065, Australia.,Department of Medicine, The University of Melbourne, Parkville, Melbourne 3065, Australia
| | - Peter Thorn
- Charles Perkins Centre, Discipline of Physiology, School of Medical Sciences, University of Sydney, Johns Hopkins Dr, Sydney 2006, Australia
| | - Ulf Ahlgren
- Umeå Centre for Molecular Medicine, Umeå University, Johan Bures väg 12, Umeå 901 87, Sweden
| | - Esteban N Gurzov
- Department of Medicine, The University of Melbourne, Parkville, Melbourne 3065, Australia.,Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Route de Lennik 808, Brussels 1070, Belgium
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7
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Schaschkow A, Pang L, Vandenbempt V, Elvira B, Litwak SA, Vekeriotaite B, Maillard E, Vermeersch M, Paula FMM, Pinget M, Perez-Morga D, Gough DJ, Gurzov EN. STAT3 Regulates Mitochondrial Gene Expression in Pancreatic β-Cells and Its Deficiency Induces Glucose Intolerance in Obesity. Diabetes 2021; 70:2026-2041. [PMID: 34183374 DOI: 10.2337/db20-1222] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 06/20/2021] [Indexed: 11/13/2022]
Abstract
Most obese and insulin-resistant individuals do not develop diabetes. This is the result of the capacity of β-cells to adapt and produce enough insulin to cover the needs of the organism. The underlying mechanism of β-cell adaptation in obesity, however, remains unclear. Previous studies have suggested a role for STAT3 in mediating β-cell development and human glucose homeostasis, but little is known about STAT3 in β-cells in obesity. We observed enhanced cytoplasmic expression of STAT3 in severely obese subjects with diabetes. To address the functional role of STAT3 in adult β-cells, we generated mice with tamoxifen-inducible partial or full deletion of STAT3 in β-cells and fed them a high-fat diet before analysis. Interestingly, β-cell heterozygous and homozygous STAT3-deficient mice showed glucose intolerance when fed a high-fat diet. Gene expression analysis with RNA sequencing showed that reduced expression of mitochondrial genes in STAT3 knocked down human EndoC-β1H cells, confirmed in FACS-purified β-cells from obese STAT3-deficient mice. Moreover, silencing of STAT3 impaired mitochondria activity in EndoC-β1H cells and human islets, suggesting a mechanism for STAT3-modulated β-cell function. Our study postulates STAT3 as a novel regulator of β-cell function in obesity.
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Affiliation(s)
- Anaïs Schaschkow
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Lokman Pang
- Department of Medicine, The University of Melbourne, Parkville, Australia
- St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Valerie Vandenbempt
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Bernat Elvira
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Sara A Litwak
- St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Beata Vekeriotaite
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Elisa Maillard
- Université de Strasbourg, Strasbourg, France
- Centre Européen d'Etude du Diabéte, Strasbourg, France
| | - Marjorie Vermeersch
- Center for Microscopy and Molecular Imaging, Université libre de Bruxelles, Brussels, Belgium
| | - Flavia M M Paula
- ULB-Center for Diabetes Research, Université libre de Bruxelles, Brussels, Belgium
| | - Michel Pinget
- Université de Strasbourg, Strasbourg, France
- Centre Européen d'Etude du Diabéte, Strasbourg, France
| | - David Perez-Morga
- Center for Microscopy and Molecular Imaging, Université libre de Bruxelles, Brussels, Belgium
| | - Daniel J Gough
- Centre for Cancer Research, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Science and Translational Medicine, Monash University, Melbourne, Australia
| | - Esteban N Gurzov
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
- Department of Medicine, The University of Melbourne, Parkville, Australia
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8
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Brahma MK, Gilglioni EH, Zhou L, Trépo E, Chen P, Gurzov EN. Oxidative stress in obesity-associated hepatocellular carcinoma: sources, signaling and therapeutic challenges. Oncogene 2021; 40:5155-5167. [PMID: 34290399 PMCID: PMC9277657 DOI: 10.1038/s41388-021-01950-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/01/2021] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
Obesity affects more than 650 million individuals worldwide and is a well-established risk factor for the development of hepatocellular carcinoma (HCC). Oxidative stress can be considered as a bona fide tumor promoter, contributing to the initiation and progression of liver cancer. Indeed, one of the key events involved in HCC progression is excessive levels of reactive oxygen species (ROS) resulting from the fatty acid influx and chronic inflammation. This review provides insights into the different intracellular sources of obesity-induced ROS and molecular mechanisms responsible for hepatic tumorigenesis. In addition, we highlight recent findings pointing to the role of the dysregulated activity of BCL-2 proteins and protein tyrosine phosphatases (PTPs) in the generation of hepatic oxidative stress and ROS-mediated dysfunctional signaling, respectively. Finally, we discuss the potential and challenges of novel nanotechnology strategies to prevent ROS formation in obesity-associated HCC.
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Affiliation(s)
- Manoja K Brahma
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Eduardo H Gilglioni
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium
| | - Lang Zhou
- Materials Research and Education Center, Auburn University, Auburn, AL, 36849, United States
| | - Eric Trépo
- Department of Gastroenterology, Hepatopancreatology and Digestive Oncology, C.U.B. Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium
- Laboratory of Experimental Gastroenterology, Université libre de Bruxelles, Brussels, Belgium
| | - Pengyu Chen
- Materials Research and Education Center, Auburn University, Auburn, AL, 36849, United States
| | - Esteban N Gurzov
- Signal Transduction and Metabolism Laboratory, Laboratoire de Gastroentérologie Expérimental et Endotools, Université libre de Bruxelles, Brussels, Belgium.
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9
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Gurzov EN, Ke PC, Ahlgren U, Garcia Ribeiro RS, Gotthardt M. Novel Strategies to Protect and Visualize Pancreatic β Cells in Diabetes. Trends Endocrinol Metab 2020; 31:905-917. [PMID: 33160815 DOI: 10.1016/j.tem.2020.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/23/2020] [Accepted: 10/12/2020] [Indexed: 12/20/2022]
Abstract
A common feature in the pathophysiology of different types of diabetes is the reduction of β cell mass and/or impairment of β cell function. Diagnosis and treatment of type 1 and type 2 diabetes is currently hampered by a lack of reliable techniques to restore β cell survival, to improve insulin secretion, and to quantify β cell mass in patients. Current new approaches may allow us to precisely and specifically visualize β cells in vivo and provide viable therapeutic strategies to preserve, recover, and regenerate β cells. In this review, we discuss recent protective approaches for β cells and the advantages and limitations of current imaging probes in the field.
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Affiliation(s)
- Esteban N Gurzov
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, Brussels 1070, Belgium.
| | - Pu Chun Ke
- Zhongshan Hospital, Fudan University, Xuhui District, Shanghai 200032, China; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Ulf Ahlgren
- Umeå Centre for Molecular Medicine, Umeå University, Umeå S-90187, Sweden
| | - Rita S Garcia Ribeiro
- Signal Transduction and Metabolism Laboratory, Université libre de Bruxelles, Brussels 1070, Belgium
| | - Martin Gotthardt
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
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10
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Affiliation(s)
- Decio L Eizirik
- ULB Center for Diabetes Research, Universite Libre de Bruxelles (ULB), Brussels, Belgium.
| | - Esteban N Gurzov
- ULB Center for Diabetes Research, Universite Libre de Bruxelles (ULB), Brussels, Belgium.
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11
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Miani M, Elvira B, Gurzov EN. Sweet Killing in Obesity and Diabetes: The Metabolic Role of the BH3-only Protein BIM. J Mol Biol 2018; 430:3041-3050. [DOI: 10.1016/j.jmb.2018.07.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/10/2018] [Accepted: 07/16/2018] [Indexed: 02/06/2023]
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12
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Ge X, Kakinen A, Gurzov EN, Yang W, Pang L, Pilkington EH, Govindan-Nedumpully P, Chen P, Separovic F, Davis TP, Ke PC, Ding F. Zinc-coordination and C-peptide complexation: a potential mechanism for the endogenous inhibition of IAPP aggregation. Chem Commun (Camb) 2018; 53:9394-9397. [PMID: 28745731 DOI: 10.1039/c7cc04291d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Aggregation of the highly amyloidogenic IAPP is endogenously inhibited inside beta-cell granules at millimolar concentrations. Combining in vitro experiments and computer simulations, we demonstrated that the stabilization of IAPP upon the formation of zinc-coordinated ion molecular complex with C-peptide might be important for the endogenous inhibition of IAPP aggregation.
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Affiliation(s)
- Xinwei Ge
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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13
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Pilkington E, Lai M, Ge X, Stanley WJ, Wang B, Wang M, Kakinen A, Sani MA, Whittaker MR, Gurzov EN, Ding F, Quinn JF, Davis TP, Ke PC. Star Polymers Reduce Islet Amyloid Polypeptide Toxicity via Accelerated Amyloid Aggregation. Biomacromolecules 2017; 18:4249-4260. [PMID: 29035554 PMCID: PMC5729549 DOI: 10.1021/acs.biomac.7b01301] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/13/2017] [Indexed: 01/20/2023]
Abstract
Protein aggregation into amyloid fibrils is a ubiquitous phenomenon across the spectrum of neurodegenerative disorders and type 2 diabetes. A common strategy against amyloidogenesis is to minimize the populations of toxic oligomers and protofibrils by inhibiting protein aggregation with small molecules or nanoparticles. However, melanin synthesis in nature is realized by accelerated protein fibrillation to circumvent accumulation of toxic intermediates. Accordingly, we designed and demonstrated the use of star-shaped poly(2-hydroxyethyl acrylate) (PHEA) nanostructures for promoting aggregation while ameliorating the toxicity of human islet amyloid polypeptide (IAPP), the peptide involved in glycemic control and the pathology of type 2 diabetes. The binding of PHEA elevated the β-sheet content in IAPP aggregates while rendering a new morphology of "stelliform" amyloids originating from the polymers. Atomistic molecular dynamics simulations revealed that the PHEA arms served as rodlike scaffolds for IAPP binding and subsequently accelerated IAPP aggregation by increased local peptide concentration. The tertiary structure of the star nanoparticles was found to be essential for driving the specific interactions required to impel the accelerated IAPP aggregation. This study sheds new light on the structure-toxicity relationship of IAPP and points to the potential of exploiting star polymers as a new class of therapeutic agents against amyloidogenesis.
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Affiliation(s)
- Emily
H. Pilkington
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - May Lai
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Xinwei Ge
- Department
of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - William J. Stanley
- St
Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia
- Department
of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Bo Wang
- Department
of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - Miaoyi Wang
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Aleksandr Kakinen
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Marc-Antonie Sani
- School of
Chemistry, Bio21 Institute, The University
of Melbourne, 30 Flemington
Rd, Parkville, Victoria 3010, Australia
| | - Michael R. Whittaker
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Esteban N. Gurzov
- St
Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia
- Department
of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Feng Ding
- Department
of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - John F. Quinn
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Thomas P. Davis
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- Department
of Chemistry, University of Warwick, Gibbet Hill, Coventry CV4 7AL, United Kingdom
| | - Pu Chun Ke
- ARC
Centre of Excellence in Convergent Bio-Nano Science and Technology,
Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
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14
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Litwak SA, Pang L, Galic S, Igoillo-Esteve M, Stanley WJ, Turatsinze JV, Loh K, Thomas HE, Sharma A, Trepo E, Moreno C, Gough DJ, Eizirik DL, de Haan JB, Gurzov EN. JNK Activation of BIM Promotes Hepatic Oxidative Stress, Steatosis, and Insulin Resistance in Obesity. Diabetes 2017; 66:2973-2986. [PMID: 28928277 DOI: 10.2337/db17-0348] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 09/13/2017] [Indexed: 11/13/2022]
Abstract
The members of the BCL-2 family are crucial regulators of the mitochondrial pathway of apoptosis in normal physiology and disease. Besides their role in cell death, BCL-2 proteins have been implicated in the regulation of mitochondrial oxidative phosphorylation and cellular metabolism. It remains unclear, however, whether these proteins have a physiological role in glucose homeostasis and metabolism in vivo. In this study, we report that fat accumulation in the liver increases c-Jun N-terminal kinase-dependent BCL-2 interacting mediator of cell death (BIM) expression in hepatocytes. To determine the consequences of hepatic BIM deficiency in diet-induced obesity, we generated liver-specific BIM-knockout (BLKO) mice. BLKO mice had lower hepatic lipid content, increased insulin signaling, and improved global glucose metabolism. Consistent with these findings, lipogenic and lipid uptake genes were downregulated and lipid oxidation enhanced in obese BLKO mice. Mechanistically, BIM deficiency improved mitochondrial function and decreased oxidative stress and oxidation of protein tyrosine phosphatases, and ameliorated activation of peroxisome proliferator-activated receptor γ/sterol regulatory element-binding protein 1/CD36 in hepatocytes from high fat-fed mice. Importantly, short-term knockdown of BIM rescued obese mice from insulin resistance, evidenced by reduced fat accumulation and improved insulin sensitivity. Our data indicate that BIM is an important regulator of liver dysfunction in obesity and a novel therapeutic target for restoring hepatocyte function.
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Affiliation(s)
- Sara A Litwak
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
| | - Lokman Pang
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sandra Galic
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
| | | | - William J Stanley
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | | | - Kim Loh
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
| | - Helen E Thomas
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Arpeeta Sharma
- Oxidative Stress Laboratory, Basic Science Division, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Eric Trepo
- Clinique Universitaire de Bruxelles, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Laboratory of Experimental Gastroenterology, Université Libre de Bruxelles, Brussels, Belgium
| | - Christophe Moreno
- Clinique Universitaire de Bruxelles, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Laboratory of Experimental Gastroenterology, Université Libre de Bruxelles, Brussels, Belgium
| | - Daniel J Gough
- Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - Judy B de Haan
- Oxidative Stress Laboratory, Basic Science Division, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Esteban N Gurzov
- St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
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15
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Stanley WJ, Trivedi PM, Sutherland AP, Thomas HE, Gurzov EN. Differential regulation of pro-inflammatory cytokine signalling by protein tyrosine phosphatases in pancreatic β-cells. J Mol Endocrinol 2017; 59:325-337. [PMID: 28827413 DOI: 10.1530/jme-17-0089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/21/2017] [Indexed: 01/19/2023]
Abstract
Type 1 diabetes (T1D) is characterized by the destruction of insulin-producing β-cells by immune cells in the pancreas. Pro-inflammatory including TNF-α, IFN-γ and IL-1β are released in the islet during the autoimmune assault and signal in β-cells through phosphorylation cascades, resulting in pro-apoptotic gene expression and eventually β-cell death. Protein tyrosine phosphatases (PTPs) are a family of enzymes that regulate phosphorylative signalling and are associated with the development of T1D. Here, we observed expression of PTPN6 and PTPN1 in human islets and islets from non-obese diabetic (NOD) mice. To clarify the role of these PTPs in β-cells/islets, we took advantage of CRISPR/Cas9 technology and pharmacological approaches to inactivate both proteins. We identify PTPN6 as a negative regulator of TNF-α-induced β-cell death, through JNK-dependent BCL-2 protein degradation. In contrast, PTPN1 acts as a positive regulator of IFN-γ-induced STAT1-dependent gene expression, which enhanced autoimmune destruction of β-cells. Importantly, PTPN1 inactivation by pharmacological modulation protects β-cells and primary mouse islets from cytokine-mediated cell death. Thus, our data point to a non-redundant effect of PTP regulation of cytokine signalling in β-cells in autoimmune diabetes.
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Affiliation(s)
- William J Stanley
- St. Vincent's Institute of Medical ResearchMelbourne, Australia
- Department of MedicineSt. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
| | - Prerak M Trivedi
- St. Vincent's Institute of Medical ResearchMelbourne, Australia
- Department of MedicineSt. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
| | | | - Helen E Thomas
- St. Vincent's Institute of Medical ResearchMelbourne, Australia
- Department of MedicineSt. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
| | - Esteban N Gurzov
- St. Vincent's Institute of Medical ResearchMelbourne, Australia
- Department of MedicineSt. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
- ULB Center for Diabetes ResearchUniversite Libre de Bruxelles (ULB), Brussels, Belgium
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16
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Jhala G, Chee J, Trivedi PM, Selck C, Gurzov EN, Graham KL, Thomas HE, Kay TW, Krishnamurthy B. Perinatal tolerance to proinsulin is sufficient to prevent autoimmune diabetes. JCI Insight 2016; 1:e86065. [PMID: 27699217 DOI: 10.1172/jci.insight.86065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
High-affinity self-reactive thymocytes are purged in the thymus, and residual self-reactive T cells, which are detectable in healthy subjects, are controlled by peripheral tolerance mechanisms. Breakdown in these mechanisms results in autoimmune disease, but antigen-specific therapy to augment natural mechanisms can prevent this. We aimed to determine when antigen-specific therapy is most effective. Islet autoantigens, proinsulin (PI), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) were expressed in the antigen-presenting cells (APCs) of autoimmune diabetes-prone nonobese diabetic (NOD) mice in a temporally controlled manner. PI expression from gestation until weaning was sufficient to completely protect NOD mice from diabetes, insulitis, and development of insulin autoantibodies. Insulin-specific T cells were significantly diminished, were naive, and did not express IFN-γ when challenged. This long-lasting effect from a brief period of treatment suggests that autoreactive T cells are not produced subsequently. We tracked IGRP206-214-specific CD8+ T cells in NOD mice expressing IGRP in APCs. When IGRP was expressed only until weaning, IGRP206-214-specific CD8+ T cells were not detected later in life. Thus, anti-islet autoimmunity is determined during early life, and autoreactive T cells are not generated in later life. Bolstering tolerance to islet antigens in the perinatal period is sufficient to impart lasting protection from diabetes.
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Affiliation(s)
- Gaurang Jhala
- St. Vincent's Institute, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Jonathan Chee
- The Harry Perkins Institute of Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | | | - Claudia Selck
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | | | - Kate L Graham
- St. Vincent's Institute, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Helen E Thomas
- St. Vincent's Institute, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Thomas Wh Kay
- St. Vincent's Institute, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Balasubramanian Krishnamurthy
- St. Vincent's Institute, Fitzroy, Victoria, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
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17
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Gurzov EN, Stanley WJ, Pappas EG, Thomas HE, Gough DJ. The JAK/STAT pathway in obesity and diabetes. FEBS J 2016; 283:3002-15. [PMID: 26972840 DOI: 10.1111/febs.13709] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/14/2016] [Accepted: 03/08/2016] [Indexed: 12/12/2022]
Abstract
Diabetes mellitus are complex, multi-organ metabolic pathologies characterized by hyperglycemia. Emerging evidence shows that the highly conserved and potent JAK/STAT signaling pathway is required for normal homeostasis, and, when dysregulated, contributes to the development of obesity and diabetes. In this review, we analyze the role of JAK/STAT activation in the brain, liver, muscle, fat and pancreas, and how this affects the course of the disease. We also consider the therapeutic implications of targeting the JAK/STAT pathway in treatment of obesity and diabetes.
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Affiliation(s)
- Esteban N Gurzov
- St Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Australia
| | - William J Stanley
- St Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Australia
| | - Evan G Pappas
- St Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Australia
| | - Helen E Thomas
- St Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Australia
| | - Daniel J Gough
- Hudson Institute of Medical Research, Clayton, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, Australia
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18
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Gurzov EN, Wang B, Pilkington EH, Chen P, Kakinen A, Stanley WJ, Litwak SA, Hanssen EG, Davis TP, Ding F, Ke PC. Inhibition of hIAPP Amyloid Aggregation and Pancreatic β-Cell Toxicity by OH-Terminated PAMAM Dendrimer. Small 2016; 12:1615-1626. [PMID: 26808649 DOI: 10.1002/smll.201502317] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 12/17/2015] [Indexed: 06/05/2023]
Abstract
Human islet amyloid polypeptide (hIAPP, or amylin) forms amyloid deposits in the islets of Langerhans, a phenomenon that is associated with type-2 diabetes impacting millions of people worldwide. Accordingly, strategies against hIAPP aggregation are essential for the prevention and eventual treatment of the disease. Here, it is shown that generation-3 OH-terminated poly(amidoamine) dendrimer, a polymeric nanoparticle, can effectively halt the aggregation of hIAPP and shut down hIAPP toxicity in pancreatic MIN6 and NIT-1 cells as well as in mouse islets. This finding is supported by high-throughput dynamic light scattering experiment and thioflavin T assay, where the rapid evolution of hIAPP nucleation and elongation processes is halted by the addition of the dendrimer up to 8 h. Discrete molecular dynamics simulations further reveal that hIAPP residues bound strongly with the dendrimer near the c-terminal portion of the peptide, where the amyloidogenic sequence (residues 22-29) locates. Furthermore, simulations of hIAPP dimerization reveal that binding with the dendrimer significantly reduces formation of interpeptide contacts and hydrogen bonds, thereby prohibiting peptide self-association and amyloidosis. This study points to a promising nanomedicinal strategy for combating type-2 diabetes and may have broader implications for targeting neurological disorders whose distinct hallmark is also amyloid fibrillation.
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Affiliation(s)
- Esteban N Gurzov
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
| | - Bo Wang
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA
| | - Emily H Pilkington
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Pengyu Chen
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 28109, USA
| | - Aleksandr Kakinen
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - William J Stanley
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Australia
| | - Sara A Litwak
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Eric G Hanssen
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC, 3010, Australia
| | - Thomas P Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634, USA
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
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19
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Pilkington EH, Gurzov EN, Kakinen A, Litwak SA, Stanley WJ, Davis TP, Ke PC. Pancreatic β-Cell Membrane Fluidity and Toxicity Induced by Human Islet Amyloid Polypeptide Species. Sci Rep 2016; 6:21274. [PMID: 26880502 PMCID: PMC4754679 DOI: 10.1038/srep21274] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/20/2016] [Indexed: 01/22/2023] Open
Abstract
Aggregation of human islet amyloid polypeptide (hIAPP) into fibrils and plaques is associated with pancreatic β-cell loss in type 2 diabetes (T2D). However, due to the rapidness of hIAPP conversion in aqueous phase, exactly which hIAPP species is responsible for the observed toxicity and through what mechanisms remains ambiguous. In light of the importance of understanding hIAPP toxicity for T2D here we show a biophysical scheme based on the use of a lipophilic Laurdan dye for examining MIN6 cell membranes upon exposure to fresh and oligomeric hIAPP as well as mature amyloid. It has been found that all three hIAPP species, especially fresh hIAPP, enhanced membrane fluidity and caused losses in cell viability. The cell generation of reactive oxygen species (ROS), however, was the most pronounced with mature amyloid hIAPP. The correlation between changes in membrane fluidity and cell viability and their lack of correlation with ROS production suggest hIAPP toxicity is elicited through both physical and biochemical means. This study offers a new insight into β-cell toxicity induced by controlled hIAPP species, as well as new biophysical methodologies that may prove beneficial for the studies of T2D as well as neurological disorders.
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Affiliation(s)
- Emily H. Pilkington
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Esteban N. Gurzov
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Aleksandr Kakinen
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Sara A. Litwak
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
| | - William J. Stanley
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Thomas P. Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, United Kingdom
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
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20
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Nedumpully-Govindan P, Gurzov EN, Chen P, Pilkington EH, Stanley WJ, Litwak SA, Davis TP, Ke PC, Ding F. Graphene oxide inhibits hIAPP amyloid fibrillation and toxicity in insulin-producing NIT-1 cells. Phys Chem Chem Phys 2016; 18:94-100. [PMID: 26625841 PMCID: PMC4684718 DOI: 10.1039/c5cp05924k] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human islet amyloid polypeptide (hIAPP or amylin) aggregation is directly associated with pancreatic β-cell death and subsequent insulin deficiency in type 2 diabetes (T2D). Since no cure is currently available for T2D, it is of great benefit to devise new anti-aggregation molecules, which protect β-cells against hIAPP aggregation-induced toxicity. Engineered nanoparticles have been recently exploited as anti-aggregation nanomedicines. In this work, we studied graphene oxide (GO) nanosheets for their potential for hIAPP aggregation inhibition by combining computational modeling, biophysical characterization and cell toxicity measurements. Using discrete molecular dynamics (DMD) simulations and in vitro studies, we showed that GO exhibited an inhibitory effect on hIAPP aggregation. DMD simulations indicated that the strong binding of hIAPP to GO nanosheets was driven by hydrogen bonding and aromatic stacking and that the strong peptide-GO binding efficiently inhibited hIAPP self-association and aggregation on the nanosheet surface. Secondary structural changes of hIAPP upon GO binding derived from DMD simulations were consistent with circular dichroism (CD) spectroscopy measurements. Transmission electron microscopy (TEM) images confirmed the reduction of hIAPP aggregation in the presence of GO. Furthermore, we carried out a cell toxicity assay and found that these nanosheets protected insulin-secreting NIT-1 pancreatic β-cells against hIAPP-induced toxicity. Our multidisciplinary study suggests that GO nanosheets have the potential to be utilized as an anti-aggregation nanomedicine itself in addition to a biosensor or delivery vehicle for the mitigation of T2D progression.
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Affiliation(s)
| | - Esteban N. Gurzov
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Pengyu Chen
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 28109, USA
| | - Emily H. Pilkington
- ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - William J. Stanley
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Melbourne, Australia
| | - Sara A. Litwak
- St Vincent’s Institute of Medical Research, 9 Princes Street, Fitzroy, VIC 3065, Australia
| | - Thomas P. Davis
- ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, United Kingdom
| | - Pu Chun Ke
- ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
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21
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Krishnamurthy B, Chee J, Jhala G, Trivedi P, Catterall T, Selck C, Gurzov EN, Brodnicki TC, Graham KL, Wali JA, Zhan Y, Gray D, Strasser A, Allison J, Thomas HE, Kay TWH. BIM Deficiency Protects NOD Mice From Diabetes by Diverting Thymocytes to Regulatory T Cells. Diabetes 2015; 64:3229-38. [PMID: 25948683 DOI: 10.2337/db14-1851] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 04/15/2015] [Indexed: 11/13/2022]
Abstract
Because regulatory T-cell (Treg) development can be induced by the same agonist self-antigens that induce negative selection, perturbation of apoptosis will affect both negative selection and Treg development. But how the processes of thymocyte deletion versus Treg differentiation bifurcate and their relative importance for tolerance have not been studied in spontaneous organ-specific autoimmune disease. We addressed these questions by removing a critical mediator of thymocyte deletion, BIM, in the NOD mouse model of autoimmune diabetes. Despite substantial defects in the deletion of autoreactive thymocytes, BIM-deficient NOD (NODBim(-/-)) mice developed less insulitis and were protected from diabetes. BIM deficiency did not impair effector T-cell function; however, NODBim(-/-) mice had increased numbers of Tregs, including those specific for proinsulin, in the thymus and peripheral lymphoid tissues. Increased levels of Nur77, CD5, GITR, and phosphorylated IκB-α in thymocytes from NODBim(-/-) mice suggest that autoreactive cells receiving strong T-cell receptor signals that would normally delete them escape apoptosis and are diverted into the Treg pathway. Paradoxically, in the NOD model, reduced thymic deletion ameliorates autoimmune diabetes by increasing Tregs. Thus, modulating apoptosis may be one of the ways to increase antigen-specific Tregs and prevent autoimmune disease.
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Affiliation(s)
- Balasubramanian Krishnamurthy
- St. Vincent's Institute, Fitzroy, Australia Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Fitzroy, Australia
| | | | | | | | | | | | | | | | | | | | - Yifan Zhan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Daniel Gray
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | | | - Helen E Thomas
- St. Vincent's Institute, Fitzroy, Australia Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Fitzroy, Australia
| | - Thomas W H Kay
- St. Vincent's Institute, Fitzroy, Australia Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Fitzroy, Australia
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22
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Stanley WJ, Litwak SA, Quah HS, Tan SM, Kay TWH, Tiganis T, de Haan JB, Thomas HE, Gurzov EN. Inactivation of Protein Tyrosine Phosphatases Enhances Interferon Signaling in Pancreatic Islets. Diabetes 2015; 64:2489-96. [PMID: 25732191 DOI: 10.2337/db14-1575] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/22/2015] [Indexed: 11/13/2022]
Abstract
Type 1 diabetes (T1D) is the result of an autoimmune assault against the insulin-producing pancreatic β-cells, where chronic local inflammation (insulitis) leads to β-cell destruction. T cells and macrophages infiltrate into islets early in T1D pathogenesis. These immune cells secrete cytokines that lead to the production of reactive oxygen species (ROS) and T-cell invasion and activation. Cytokine-signaling pathways are very tightly regulated by protein tyrosine phosphatases (PTPs) to prevent excessive activation. Here, we demonstrate that pancreata from NOD mice with islet infiltration have enhanced oxidation/inactivation of PTPs and STAT1 signaling compared with NOD mice that do not have insulitis. Inactivation of PTPs with sodium orthovanadate in human and rodent islets and β-cells leads to increased activation of interferon signaling and chemokine production mediated by STAT1 phosphorylation. Furthermore, this exacerbated STAT1 activation-induced cell death in islets was prevented by overexpression of the suppressor of cytokine signaling-1 or inactivation of the BH3-only protein Bim. Together our data provide a mechanism by which PTP inactivation induces signaling in pancreatic islets that results in increased expression of inflammatory genes and exacerbated insulitis.
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Affiliation(s)
- William J Stanley
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sara A Litwak
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia
| | - Hong Sheng Quah
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sih Min Tan
- Diabetic Complications Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Thomas W H Kay
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Judy B de Haan
- Diabetic Complications Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Helen E Thomas
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Esteban N Gurzov
- St Vincent's Institute of Medical Research, Melbourne, Victoria, Australia Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
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23
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Gurzov EN, Stanley WJ, Brodnicki TC, Thomas HE. Protein tyrosine phosphatases: molecular switches in metabolism and diabetes. Trends Endocrinol Metab 2015; 26:30-9. [PMID: 25432462 DOI: 10.1016/j.tem.2014.10.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 10/28/2014] [Accepted: 10/30/2014] [Indexed: 02/06/2023]
Abstract
Protein tyrosine phosphatases (PTPs) are a large family of enzymes that generally oppose the actions of protein tyrosine kinases (PTKs). Genetic polymorphisms for particular PTPs are associated with altered risk of both type 1 diabetes (T1D) and type 2 diabetes (T2D). Moreover, recent evidence suggests that PTPs play crucial roles in metabolism. They can act as regulators of liver homeostasis, food intake, or immune-mediated pancreatic b cell death. In this review we describe the mechanisms by which different members of the non-receptor PTP (PTPN) family influence metabolic physiology. This 'metabolic job' of PTPs is discussed in depth and the role of these proteins in different cell types compared. Understanding the pathways regulated by PTPs will provide novel therapeutic strategies for the treatment of diabetes.
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24
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Litwak SA, Wali JA, Pappas EG, Saadi H, Stanley WJ, Varanasi LC, Kay TWH, Thomas HE, Gurzov EN. Lipotoxic Stress Induces Pancreatic β-Cell Apoptosis through Modulation of Bcl-2 Proteins by the Ubiquitin-Proteasome System. J Diabetes Res 2015; 2015:280615. [PMID: 26064977 PMCID: PMC4438180 DOI: 10.1155/2015/280615] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 01/09/2023] Open
Abstract
Pancreatic β-cell loss induced by saturated free fatty acids (FFAs) is believed to contribute to type 2 diabetes. Previous studies have shown induction of endoplasmic reticulum (ER) stress, increased ubiquitinated proteins, and deregulation of the Bcl-2 family in the pancreas of type 2 diabetic patients. However, the precise mechanism of β-cell death remains unknown. In the present study we demonstrate that the FFA palmitate blocks the ubiquitin-proteasome system (UPS) and causes apoptosis through induction of ER stress and deregulation of Bcl-2 proteins. We found that palmitate and the proteasome inhibitor MG132 induced ER stress in β-cells, resulting in decreased expression of the prosurvival proteins Bcl-2, Mcl-1, and Bcl-XL, and upregulation of the prodeath BH3-only protein PUMA. On the other hand, pharmacological activation of the UPS by sulforaphane ameliorated ER stress, upregulated prosurvival Bcl-2 proteins, and protected β-cells from FFA-induced cell death. Furthermore, transgenic overexpression of Bcl-2 protected islets from FFA-induced cell death in vitro and improved glucose-induced insulin secretion in vivo. Together our results suggest that targeting the UPS and Bcl-2 protein expression may be a valuable strategy to prevent β-cell demise in type 2 diabetes.
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Affiliation(s)
- Sara A. Litwak
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
| | - Jibran A. Wali
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Evan G. Pappas
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Hamdi Saadi
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - William J. Stanley
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - L. Chitra Varanasi
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Thomas W. H. Kay
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Helen E. Thomas
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Esteban N. Gurzov
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
- *Esteban N. Gurzov:
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25
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Wali JA, Gurzov EN, Fynch S, Elkerbout L, Kay TW, Masters SL, Thomas HE. Activation of the NLRP3 inflammasome complex is not required for stress-induced death of pancreatic islets. PLoS One 2014; 9:e113128. [PMID: 25405767 PMCID: PMC4236141 DOI: 10.1371/journal.pone.0113128] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 10/20/2014] [Indexed: 01/09/2023] Open
Abstract
Loss of pancreatic beta cells is a feature of type-2 diabetes. High glucose concentrations induce endoplasmic reticulum (ER) and oxidative stress-mediated apoptosis of islet cells invitro. ER stress, oxidative stress and high glucose concentrations may also activate the NLRP3 inflammasome leading to interleukin (IL)-1β production and caspase-1 dependent pyroptosis. However, whether IL-1β or intrinsic NLRP3 inflammasome activation contributes to beta cell death is controversial. This possibility was examined in mouse islets. Exposure of islets lacking functional NLRP3 or caspase-1 to H2O2, rotenone or thapsigargin induced similar cell death as in wild-type islets. This suggests that oxidative or ER stress do not cause inflammasome-mediated cell death. Similarly, deficiency of NLRP3 inflammasome components did not provide any protection from glucose, ribose or gluco-lipotoxicity. Finally, genetic activation of NLRP3 specifically in beta cells did not increase IL-1β production or cell death, even in response to glucolipotoxicity. Overall, our results show that glucose-, ER stress- or oxidative stress-induced cell death in islet cells is not dependent on intrinsic activation of the NLRP3 inflammasome.
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Affiliation(s)
- Jibran A. Wali
- St Vincent’s Institute, Fitzroy, Victoria, Australia
- The University of Melbourne Department of Medicine, St. Vincent’s Hospital, Fitzroy, Victoria, Australia
| | - Esteban N. Gurzov
- St Vincent’s Institute, Fitzroy, Victoria, Australia
- The University of Melbourne Department of Medicine, St. Vincent’s Hospital, Fitzroy, Victoria, Australia
| | - Stacey Fynch
- St Vincent’s Institute, Fitzroy, Victoria, Australia
| | | | - Thomas W. Kay
- St Vincent’s Institute, Fitzroy, Victoria, Australia
- The University of Melbourne Department of Medicine, St. Vincent’s Hospital, Fitzroy, Victoria, Australia
| | - Seth L. Masters
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Helen E. Thomas
- St Vincent’s Institute, Fitzroy, Victoria, Australia
- The University of Melbourne Department of Medicine, St. Vincent’s Hospital, Fitzroy, Victoria, Australia
- * E-mail:
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26
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Gurzov EN, Tran M, Fernandez-Rojo MA, Merry TL, Zhang X, Xu Y, Fukushima A, Waters MJ, Watt MJ, Andrikopoulos S, Neel BG, Tiganis T. Hepatic oxidative stress promotes insulin-STAT-5 signaling and obesity by inactivating protein tyrosine phosphatase N2. Cell Metab 2014; 20:85-102. [PMID: 24954415 PMCID: PMC4335267 DOI: 10.1016/j.cmet.2014.05.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/23/2014] [Accepted: 04/28/2014] [Indexed: 12/18/2022]
Abstract
Hepatic insulin resistance is a key contributor to the pathogenesis of obesity and type 2 diabetes (T2D). Paradoxically, the development of insulin resistance in the liver is not universal, but pathway selective, such that insulin fails to suppress gluconeogenesis but promotes lipogenesis, contributing to the hyperglycemia, steatosis, and hypertriglyceridemia that underpin the deteriorating glucose control and microvascular complications in T2D. The molecular basis for the pathway-specific insulin resistance remains unknown. Here we report that oxidative stress accompanying obesity inactivates protein-tyrosine phosphatases (PTPs) in the liver to activate select signaling pathways that exacerbate disease progression. In obese mice, hepatic PTPN2 (TCPTP) inactivation promoted lipogenesis and steatosis and insulin-STAT-5 signaling. The enhanced STAT-5 signaling increased hepatic IGF-1 production, which suppressed central growth hormone release and exacerbated the development of obesity and T2D. Our studies define a mechanism for the development of selective insulin resistance with wide-ranging implications for diseases characterized by oxidative stress.
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Affiliation(s)
- Esteban N Gurzov
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Melanie Tran
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Manuel A Fernandez-Rojo
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Troy L Merry
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Xinmei Zhang
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Yang Xu
- Princess Margaret Cancer Center, University Health Network, 101 College Street, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Atsushi Fukushima
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Michael J Waters
- Institute for Molecular Bioscience, Services Road, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Matthew J Watt
- Department of Physiology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine Heidelberg Repatriation Hospital, 300 Waterdale Road, Heidelberg West, The University of Melbourne, VIC 3081, Australia
| | - Benjamin G Neel
- Princess Margaret Cancer Center, University Health Network, 101 College Street, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia.
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27
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Cunha DA, Gurzov EN, Naamane N, Ortis F, Cardozo AK, Bugliani M, Marchetti P, Eizirik DL, Cnop M. JunB protects β-cells from lipotoxicity via the XBP1-AKT pathway. Cell Death Differ 2014; 21:1313-24. [PMID: 24786832 DOI: 10.1038/cdd.2014.53] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 03/18/2014] [Accepted: 03/20/2014] [Indexed: 12/24/2022] Open
Abstract
Diets rich in saturated fats may contribute to the loss of pancreatic β-cells in type 2 diabetes. JunB, a member of the activating protein 1 (AP-1) transcription factor family, promotes β-cell survival and mediates part of the beneficial effects of GLP-1 agonists. In this study we interrogated the molecular mechanisms involved in JunB-mediated β-cell protection from lipotoxicity. The saturated fatty acid palmitate decreased JunB expression, and this loss may contribute to β-cell apoptosis, as overexpression of JunB protected cells from lipotoxicity. Array analysis of JunB-deficient β-cells identified a gene expression signature of a downregulated endoplasmic reticulum (ER) stress response and inhibited AKT signaling. JunB stimulates XBP1 expression via the transcription factor c/EBPδ during ER stress, and forced expression of XBP1s rescued the viability of JunB-deficient cells, constituting an important antiapoptotic mechanism. JunB silencing inhibited AKT activation and activated the proapoptotic Bcl-2 protein BAD via its dephosphorylation. BAD knockdown reversed lipotoxic β-cell death potentiated by JunB siRNA. Interestingly, XBP1s links JunB and AKT signaling as XBP1 knockdown also reduced AKT phosphorylation. GLP-1 agonists induced cAMP-dependent AKT phosphorylation leading to β-cell protection against palmitate-induced apoptosis. JunB and XBP1 knockdown or IRE1 inhibition decreased AKT activation by cAMP, leading to β-cell apoptosis. In conclusion, JunB modulates the β-cell ER stress response and AKT signaling via the induction of XBP1s. The activation of the JunB gene network and the crosstalk between the ER stress and AKT pathway constitute a crucial defense mechanism by which GLP-1 agonists protect against lipotoxic β-cell death. These findings elucidate novel β-cell-protective signal transduction in type 2 diabetes.
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Affiliation(s)
- D A Cunha
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - E N Gurzov
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - N Naamane
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - F Ortis
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - A K Cardozo
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - M Bugliani
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - P Marchetti
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - D L Eizirik
- Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium
| | - M Cnop
- 1] Laboratory of Experimental Medicine and ULB Center of Diabetes Research, Université Libre de Bruxelles, Brussels, Belgium [2] Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
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28
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Shields BJ, Wiede F, Gurzov EN, Wee K, Hauser C, Zhu HJ, Molloy TJ, O'Toole SA, Daly RJ, Sutherland RL, Mitchell CA, McLean CA, Tiganis T. TCPTP regulates SFK and STAT3 signaling and is lost in triple-negative breast cancers. Mol Cell Biol 2013; 33:557-70. [PMID: 23166300 PMCID: PMC3554209 DOI: 10.1128/mcb.01016-12] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 11/12/2012] [Indexed: 01/08/2023] Open
Abstract
Tyrosine phosphorylation-dependent signaling, as mediated by members of the epidermal growth factor receptor (EGFR) family (ErbB1 to -4) of protein tyrosine kinases (PTKs), Src family PTKs (SFKs), and cytokines such as interleukin-6 (IL-6) that signal via signal transducer and activator of transcription 3 (STAT3), is critical to the development and progression of many human breast cancers. EGFR, SFKs, and STAT3 can serve as substrates for the protein tyrosine phosphatase TCPTP (PTPN2). Here we report that TCPTP protein levels are decreased in a subset of breast cancer cell lines in vitro and that TCPTP protein is absent in a large proportion of "triple-negative" primary human breast cancers. Homozygous TCPTP deficiency in murine mammary fat pads in vivo is associated with elevated SFK and STAT3 signaling, whereas TCPTP deficiency in human breast cancer cell lines enhances SFK and STAT3 signaling. On the other hand, TCPTP reconstitution in human breast cancer cell lines severely impaired cell proliferation and suppressed anchorage-independent growth in vitro and xenograft growth in vivo. These studies establish TCPTP's potential to serve as a tumor suppressor in human breast cancer.
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Affiliation(s)
- Benjamin J. Shields
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Florian Wiede
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Esteban N. Gurzov
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Kenneth Wee
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Christine Hauser
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Hong-Jian Zhu
- Department of Surgery, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Timothy J. Molloy
- The Kinghorn Cancer Centre & Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Sandra A. O'Toole
- The Kinghorn Cancer Centre & Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
- Central Clinical School, University of Sydney, Sydney, New South Wales, Australia
| | - Roger J. Daly
- The Kinghorn Cancer Centre & Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, University of NSW, Kensington, New South Wales, Australia
| | - Robert L. Sutherland
- The Kinghorn Cancer Centre & Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, University of NSW, Kensington, New South Wales, Australia
| | - Christina A. Mitchell
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Catriona A. McLean
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria, Australia
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Cunha DA, Igoillo-Esteve M, Gurzov EN, Germano CM, Naamane N, Marhfour I, Fukaya M, Vanderwinden JM, Gysemans C, Mathieu C, Marselli L, Marchetti P, Harding HP, Ron D, Eizirik DL, Cnop M. Death protein 5 and p53-upregulated modulator of apoptosis mediate the endoplasmic reticulum stress-mitochondrial dialog triggering lipotoxic rodent and human β-cell apoptosis. Diabetes 2012; 61:2763-75. [PMID: 22773666 PMCID: PMC3478544 DOI: 10.2337/db12-0123] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Environmental factors such as diets rich in saturated fats contribute to dysfunction and death of pancreatic β-cells in diabetes. Endoplasmic reticulum (ER) stress is elicited in β-cells by saturated fatty acids. Here we show that palmitate-induced β-cell apoptosis is mediated by the intrinsic mitochondrial pathway. By microarray analysis, we identified a palmitate-triggered ER stress gene expression signature and the induction of the BH3-only proteins death protein 5 (DP5) and p53-upregulated modulator of apoptosis (PUMA). Knockdown of either protein reduced cytochrome c release, caspase-3 activation, and apoptosis in rat and human β-cells. DP5 induction depends on inositol-requiring enzyme 1 (IRE1)-dependent c-Jun NH₂-terminal kinase and PKR-like ER kinase (PERK)-induced activating transcription factor (ATF3) binding to its promoter. PUMA expression is also PERK/ATF3-dependent, through tribbles 3 (TRB3)-regulated AKT inhibition and FoxO3a activation. DP5(-/-) mice are protected from high fat diet-induced loss of glucose tolerance and have twofold greater pancreatic β-cell mass. This study elucidates the crosstalk between lipotoxic ER stress and the mitochondrial pathway of apoptosis that causes β-cell death in diabetes.
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Affiliation(s)
- Daniel A. Cunha
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Esteban N. Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Carla M. Germano
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Najib Naamane
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Ihsane Marhfour
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Makiko Fukaya
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Conny Gysemans
- Laboratory of Experimental Medicine Endocrinology (LEGENDO), Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Chantal Mathieu
- Laboratory of Experimental Medicine Endocrinology (LEGENDO), Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Lorella Marselli
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - Heather P. Harding
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge, U.K
| | - David Ron
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge, U.K
| | - Décio L. Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Miriam Cnop
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
- Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
- Corresponding author: Miriam Cnop,
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Santin I, Moore F, Colli ML, Gurzov EN, Marselli L, Marchetti P, Eizirik DL. PTPN2, a candidate gene for type 1 diabetes, modulates pancreatic β-cell apoptosis via regulation of the BH3-only protein Bim. Diabetes 2011; 60:3279-88. [PMID: 21984578 PMCID: PMC3219938 DOI: 10.2337/db11-0758] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Genome-wide association studies allowed the identification of several associations between specific loci and type 1 diabetes (T1D). However, the mechanisms by which most candidate genes predispose to T1D remain unclear. We presently evaluated the mechanisms by which PTPN2, a candidate gene for T1D, modulates β-cell apoptosis after exposure to type I and II interferons (IFNs), cytokines that contribute to β-cell loss in early T1D. RESEARCH DESIGN AND METHODS Small interfering RNAs were used to inhibit PTPN2, STAT1, Bim, and Jun NH(2)-terminal kinase 1 (JNK1) expression. Cell death was assessed by Hoechst and propidium iodide staining. BAX translocation, Bim phosphorylation, cytochrome c release, and caspases 9 and 3 activation were measured by Western blot or immunofluorescence. RESULTS PTPN2 knockdown exacerbated type I IFN-induced apoptosis in INS-1E, primary rat, and human β-cells. PTPN2 silencing and exposure to type I and II IFNs induced BAX translocation to the mitochondria, cytochrome c release, and caspase 3 activation. There was also an increase in Bim phosphorylation that was at least in part regulated by JNK1. Of note, both Bim and JNK1 knockdown protected β-cells against IFN-induced apoptosis in PTPN2-silenced cells. CONCLUSIONS The present findings suggest that local IFN production may interact with a genetic factor (PTPN2) to induce aberrant proapoptotic activity of the BH3-only protein Bim, resulting in increased β-cell apoptosis via JNK activation and the intrinsic apoptotic pathway. This is the first indication of a direct interaction between a candidate gene for T1D and the activation of a specific downstream proapoptotic pathway in β-cells.
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Affiliation(s)
- Izortze Santin
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabrice Moore
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Maikel L. Colli
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Esteban N. Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Lorella Marselli
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Decio L. Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
- Corresponding author: Decio L. Eizirik,
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31
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Barthson J, Germano CM, Moore F, Maida A, Drucker DJ, Marchetti P, Gysemans C, Mathieu C, Nuñez G, Jurisicova A, Eizirik DL, Gurzov EN. Cytokines tumor necrosis factor-α and interferon-γ induce pancreatic β-cell apoptosis through STAT1-mediated Bim protein activation. J Biol Chem 2011; 286:39632-43. [PMID: 21937453 PMCID: PMC3234786 DOI: 10.1074/jbc.m111.253591] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 09/13/2011] [Indexed: 11/06/2022] Open
Abstract
Type 1 diabetes is characterized by local inflammation (insulitis) in the pancreatic islets causing β-cell loss. The mitochondrial pathway of apoptosis is regulated by the balance and interaction between Bcl-2 members. Here we clarify the molecular mechanism of β-cell death triggered by the pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ. The combination of TNF-α + IFN-γ induced DP5, p53 up-regulated modulator of apoptosis (PUMA), and Bim expression in human islets and rodent β-cells. DP5 and PUMA inactivation by RNA interference partially protected against TNF-α + IFN-γ-induced β-cell apoptosis. DP5 knock-out mice had increased β-cell area, and isolated islets from these mice were resistant to cytokine exposure. Bim expression was transcriptionally regulated by STAT1, and its activation triggered cleavage of caspases. Silencing of Bim protected rodent and human β-cells to a large extent against TNF-α + IFN-γ, indicating a major role of this BH3-only activator protein in the mechanism of apoptosis. Our data support a highly regulated and context-dependent modulation of specific Bcl-2 members controlling the mitochondrial pathway of β-cell apoptosis during insulitis.
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Affiliation(s)
- Jenny Barthson
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Carla M. Germano
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Fabrice Moore
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | | | | | - Piero Marchetti
- the Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, 56126 Pisa, Italy
| | - Conny Gysemans
- the Department of Experimental Medicine Endocrinology, Faculty of Medicine, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium, and
| | - Chantal Mathieu
- the Department of Experimental Medicine Endocrinology, Faculty of Medicine, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium, and
| | - Gabriel Nuñez
- the Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Andrea Jurisicova
- Obstetrics and Gynecology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario M5G 1X5, Canada
| | - Decio L. Eizirik
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Esteban N. Gurzov
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
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32
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Colli ML, Nogueira TC, Allagnat F, Cunha DA, Gurzov EN, Cardozo AK, Roivainen M, Op de beeck A, Eizirik DL. Exposure to the viral by-product dsRNA or Coxsackievirus B5 triggers pancreatic beta cell apoptosis via a Bim / Mcl-1 imbalance. PLoS Pathog 2011; 7:e1002267. [PMID: 21977009 PMCID: PMC3178579 DOI: 10.1371/journal.ppat.1002267] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 07/27/2011] [Indexed: 12/20/2022] Open
Abstract
The rise in type 1 diabetes (T1D) incidence in recent decades is probably related to modifications in environmental factors. Viruses are among the putative environmental triggers of T1D. The mechanisms regulating beta cell responses to viruses, however, remain to be defined. We have presently clarified the signaling pathways leading to beta cell apoptosis following exposure to the viral mimetic double-stranded RNA (dsRNA) and a diabetogenic enterovirus (Coxsackievirus B5). Internal dsRNA induces cell death via the intrinsic mitochondrial pathway. In this process, activation of the dsRNA-dependent protein kinase (PKR) promotes eIF2α phosphorylation and protein synthesis inhibition, leading to downregulation of the antiapoptotic Bcl-2 protein myeloid cell leukemia sequence 1 (Mcl-1). Mcl-1 decrease results in the release of the BH3-only protein Bim, which activates the mitochondrial pathway of apoptosis. Indeed, Bim knockdown prevented both dsRNA- and Coxsackievirus B5-induced beta cell death, and counteracted the proapoptotic effects of Mcl-1 silencing. These observations indicate that the balance between Mcl-1 and Bim is a key factor regulating beta cell survival during diabetogenic viral infections.
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Affiliation(s)
- Maikel L. Colli
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Tatiane C. Nogueira
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Florent Allagnat
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Daniel A. Cunha
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Esteban N. Gurzov
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Alessandra K. Cardozo
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Merja Roivainen
- Intestinal Viruses Unit, Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare (THL), Helsinki, Finland
| | - Anne Op de beeck
- Virology Unit, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Decio L. Eizirik
- Laboratory of Experimental Medicine, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
- * E-mail:
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33
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Gurzov EN, Barthson J, Marhfour I, Ortis F, Naamane N, Igoillo-Esteve M, Gysemans C, Mathieu C, Kitajima S, Marchetti P, Ørntoft TF, Bakiri L, Wagner EF, Eizirik DL. Pancreatic β-cells activate a JunB/ATF3-dependent survival pathway during inflammation. Oncogene 2011; 31:1723-32. [PMID: 21841823 DOI: 10.1038/onc.2011.353] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Destruction of insulin-producing pancreatic β-cells by local autoimmune inflammation is a hallmark of type 1 diabetes. Histochemical analysis of pancreases from non-obese diabetic mice indicated activation of the transcription factor JunB/AP-1 (activator protein-1) after autoimmune infiltration of the islets. In vitro studies demonstrated that the cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ induce JunB expression as a protective mechanism against apoptosis in both human and rodent β-cells. The gene network affected was studied by microarray analysis showing that JunB regulates nearly 20% of the cytokine-modified β-cell genes, including the transcription factor ATF3. Direct transcriptional induction of ATF3 by JunB is a key event for β-cell survival after TNF-α+IFN-γ treatment. Moreover, pharmacological upregulation of JunB/ATF3 via increased cAMP protected rodent primary β-cells and human islet cells against pro-inflammatory mediators. These results were confirmed in genetically modified islets derived from Ubi-JunB transgenic mice. Our findings identify ATF3 as a novel downstream target of JunB in the survival mechanism of β-cells under inflammatory stress.
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Affiliation(s)
- E N Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium.
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Arif S, Moore F, Marks K, Bouckenooghe T, Dayan CM, Planas R, Vives-Pi M, Powrie J, Tree T, Marchetti P, Huang GC, Gurzov EN, Pujol-Borrell R, Eizirik DL, Peakman M. Peripheral and islet interleukin-17 pathway activation characterizes human autoimmune diabetes and promotes cytokine-mediated β-cell death. Diabetes 2011; 60:2112-9. [PMID: 21659501 PMCID: PMC3142078 DOI: 10.2337/db10-1643] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 05/05/2011] [Indexed: 12/17/2022]
Abstract
OBJECTIVE CD4 T-cells secreting interleukin (IL)-17 are implicated in several human autoimmune diseases, but their role in type 1 diabetes has not been defined. To address the relevance of such cells, we examined IL-17 secretion in response to β-cell autoantigens, IL-17A gene expression in islets, and the potential functional consequences of IL-17 release for β-cells. RESEARCH DESIGN AND METHODS Peripheral blood CD4 T-cell responses to β-cell autoantigens (proinsulin, insulinoma-associated protein, and GAD65 peptides) were measured by IL-17 enzyme-linked immunospot assay in patients with new-onset type 1 diabetes (n = 50). mRNA expression of IL-17A and IFNG pathway genes was studied by qRT-PCR using islets obtained from subjects who died 5 days and 10 years after diagnosis of disease, respectively, and from matched control subjects. IL-17 effects on the function of human islets, rat β-cells, and the rat insulinoma cell line INS-1E were examined. RESULTS A total of 27 patients (54%) showed IL-17 reactivity to one or more β-cell peptides versus 3 of 30 (10%) control subjects (P = 0.0001). In a single case examined close to diagnosis, islet expression of IL17A, RORC, and IL22 was detected. It is noteworthy that we show that IL-17 mediates significant and reproducible enhancement of IL-1β/interferon (IFN)-γ-induced and tumor necrosis factor (TNF)-α/IFN-γ-induced apoptosis in human islets, rat β-cells, and INS-1E cells, in association with significant upregulation of β-cell IL17RA expression via activation of the transcription factors STAT1 and nuclear factor (NF)-κB. CONCLUSIONS Circulating IL-17(+) β-cell-specific autoreactive CD4 T-cells are a feature of type 1 diabetes diagnosis. We disclose a novel pathway to β-cell death involving IL-17 and STAT1 and NF-κB, rendering this cytokine a novel disease biomarker and potential therapeutic target.
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Affiliation(s)
- Sefina Arif
- Department of Immunobiology, School of Medicine, King’s College London, London, U.K
| | - Fabrice Moore
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Katherine Marks
- Department of Immunobiology, School of Medicine, King’s College London, London, U.K
| | - Thomas Bouckenooghe
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Colin M. Dayan
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, U.K
| | - Raquel Planas
- Laboratory of Immunobiology, Blood and Tissue Bank, Institut d’Investigacio Germans Trias i Pujol, Barcelona, Spain
| | - Marta Vives-Pi
- Laboratory of Immunobiology, Blood and Tissue Bank, Institut d’Investigacio Germans Trias i Pujol, Barcelona, Spain
| | - Jake Powrie
- Department of Diabetes and Endocrinology, Guy’s & St Thomas’ Hospital National Health Service (NHS) Foundation Trust, London, U.K
- National Institute for Health Research Biomedical Research Centre at Guy’s & St Thomas’ NHS Foundation Trust and King’s College London, London, U.K
| | - Timothy Tree
- Department of Immunobiology, School of Medicine, King’s College London, London, U.K
| | - Piero Marchetti
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Guo Cai Huang
- Diabetes Research Group, School of Medicine, King’s College London, London, U.K
| | - Esteban N. Gurzov
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Ricardo Pujol-Borrell
- Department of Diabetes and Endocrinology, Guy’s & St Thomas’ Hospital National Health Service (NHS) Foundation Trust, London, U.K
| | - Decio L. Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Mark Peakman
- Department of Immunobiology, School of Medicine, King’s College London, London, U.K
- National Institute for Health Research Biomedical Research Centre at Guy’s & St Thomas’ NHS Foundation Trust and King’s College London, London, U.K
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35
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Gurzov EN, Eizirik DL. Bcl-2 proteins in diabetes: mitochondrial pathways of β-cell death and dysfunction. Trends Cell Biol 2011; 21:424-31. [PMID: 21481590 DOI: 10.1016/j.tcb.2011.03.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 03/03/2011] [Accepted: 03/09/2011] [Indexed: 01/08/2023]
Abstract
Diabetes is a metabolic disease affecting nearly 300 million individuals worldwide. Both types of diabetes (1 and 2) are characterized by loss of functional pancreatic β-cell mass causing different degrees of insulin deficiency. The Bcl-2 family has a double-edged effect in diabetes. These proteins are crucial controllers of the mitochondrial pathway of β-cell apoptosis induced by pro-inflammatory cytokines or lipotoxicity. In parallel, some Bcl-2 members also regulate glucose metabolism and β-cell function. In this review, we describe the role of Bcl-2 proteins in β-cell homeostasis and death. We focus on how these proteins interact, their contribution to the crosstalk between endoplasmic reticulum stress and mitochondrial permeabilization, their context-dependent usage following different pro-apoptotic stimuli, and their role in β-cell physiology.
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Affiliation(s)
- Esteban N Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Route de Lennik, 808, 1070, Brussels, Belgium.
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36
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Abstract
Type 1 diabetes is a chronic autoimmune disease with a strong inflammatory component. We have previously shown that expression of the transcriptional repressor B-cell lymphoma (BCL)-6 is very low in pancreatic β-cells, which may favor prolonged proinflammatory responses after exposure to the cytokines IL-1β and interferon γ. Here we investigated whether cytokine-induced inflammation and apoptosis can be prevented in β-cells by BCL-6 expression using plasmid, prolactin, and adenoviral approaches. The induction of mild or abundant BCL-6 expression in β-cells by prolactin or an adenoviral BCL-6 expression construct, respectively, reduced cytokine-induced inflammatory responses in a dose-dependent manner through inhibition of nuclear factor-κB activation. BCL-6 decreased Fas and inducible nitric oxide synthase expression and nitric oxide production, but it inhibited the expression of the antiapoptotic proteins Bcl-2 and JunB while increasing the expression of the proapoptotic death protein 5. The net result of these opposite effects was an augmentation of β-cell apoptosis. In conclusion, BCL-6 expression tones down the unrestrained cytokine-induced proinflammatory response of β-cells but it also favors gene networks leading to apoptosis. This suggests that cytokine-induced proinflammatory and proapoptotic signals can be dissociated in β-cells. Further understanding of these pathways may open new possibilities to improve β-cell survival in early type 1 diabetes or after transplantation.
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Affiliation(s)
- Mariana Igoillo-Esteve
- Laboratory of Experimental Medicine, Erasmus Hospital, Universite´ Libre de Bruxelles, 1070 Brussels, Belgium
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37
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Moore F, Naamane N, Colli ML, Bouckenooghe T, Ortis F, Gurzov EN, Igoillo-Esteve M, Mathieu C, Bontempi G, Thykjaer T, Ørntoft TF, Eizirik DL. STAT1 is a master regulator of pancreatic {beta}-cell apoptosis and islet inflammation. J Biol Chem 2010; 286:929-41. [PMID: 20980260 DOI: 10.1074/jbc.m110.162131] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cytokines produced by islet-infiltrating immune cells induce β-cell apoptosis in type 1 diabetes. The IFN-γ-regulated transcription factors STAT1/IRF-1 have apparently divergent effects on β-cells. Thus, STAT1 promotes apoptosis and inflammation, whereas IRF-1 down-regulates inflammatory mediators. To understand the molecular basis for these differential outcomes within a single signal transduction pathway, we presently characterized the gene networks regulated by STAT1 and IRF-1 in β-cells. This was done by using siRNA approaches coupled to microarray analysis of insulin-producing cells exposed or not to IL-1β and IFN-γ. Relevant microarray findings were further studied in INS-1E cells and primary rat β-cells. STAT1, but not IRF-1, mediates the cytokine-induced loss of the differentiated β-cell phenotype, as indicated by decreased insulin, Pdx1, MafA, and Glut2. Furthermore, STAT1 regulates cytokine-induced apoptosis via up-regulation of the proapoptotic protein DP5. STAT1 and IRF-1 have opposite effects on cytokine-induced chemokine production, with IRF-1 exerting negative feedback inhibition on STAT1 and downstream chemokine expression. The present study elucidates the transcriptional networks through which the IFN-γ/STAT1/IRF-1 axis controls β-cell function/differentiation, demise, and islet inflammation.
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Affiliation(s)
- Fabrice Moore
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, B-1070 Brussels, Belgium
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38
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Gurzov EN, Germano CM, Cunha DA, Ortis F, Vanderwinden JM, Marchetti P, Zhang L, Eizirik DL. p53 up-regulated modulator of apoptosis (PUMA) activation contributes to pancreatic beta-cell apoptosis induced by proinflammatory cytokines and endoplasmic reticulum stress. J Biol Chem 2010; 285:19910-20. [PMID: 20421300 DOI: 10.1074/jbc.m110.122374] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Type 1 diabetes is an autoimmune disorder characterized by chronic inflammation and pancreatic beta-cell loss. Here, we demonstrate that the proinflammatory cytokine interleukin-1beta, combined with interferon-gamma, induces the expression of the Bcl-2 homology 3 (BH3)-only activator PUMA (p53 up-regulated modulator of apoptosis) in beta-cells. Transcriptional activation of PUMA is regulated by nuclear factor-kappaB and endoplasmic reticulum stress but is independent of p53. PUMA activation leads to mitochondrial Bax translocation, cytochrome c release, and caspase-3 cleavage resulting in beta-cell demise. The antiapoptotic Bcl-XL protein is localized mainly at the mitochondria of the beta-cells and antagonizes PUMA action, but Bcl-XL is inactivated by the BH3-only sensitizer DP5/Hrk in cytokine-exposed beta-cells. Moreover, a pharmacological mimic of the BH3-only sensitizer Bad, which inhibits Bcl-XL and Bcl-2, induces PUMA-dependent beta-cell death and potentiates cytokine-induced apoptosis. Our data support a hierarchical activation of BH3-only proteins controlling the intrinsic pathway of beta-cell apoptosis in the context of inflammation and type 1 diabetes.
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Affiliation(s)
- Esteban N Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Route de Lennik, 808, CP-618, 1070 Brussels, Belgium.
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Colli ML, Moore F, Gurzov EN, Ortis F, Eizirik DL. MDA5 and PTPN2, two candidate genes for type 1 diabetes, modify pancreatic beta-cell responses to the viral by-product double-stranded RNA. Hum Mol Genet 2010; 19:135-46. [PMID: 19825843 PMCID: PMC2792153 DOI: 10.1093/hmg/ddp474] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
β-Cell destruction in type 1 diabetes (T1D) is at least in part consequence of a ‘dialog’ between β-cells and immune system. This dialog may be affected by the individual's genetic background. We presently evaluated whether modulation of MDA5 and PTPN2, two candidate genes for T1D, affects β-cell responses to double-stranded RNA (dsRNA), a by-product of viral replication. These genes were selected following comparison between known candidate genes for T1D and genes expressed in pancreatic β-cells, as identified in previous array analysis. INS-1E cells and primary fluorescence-activated cell sorting-purified rat β-cells were transfected with small interference RNAs (siRNAs) targeting MDA5 or PTPN2 and subsequently exposed to intracellular synthetic dsRNA (polyinosinic–polycitidilic acid—PIC). Real-time RT–PCR, western blot and viability assays were performed to characterize gene/protein expression and viability. PIC increased MDA5 and PTPN2 mRNA expression, which was inhibited by the specific siRNAs. PIC triggered apoptosis in INS-1E and primary β-cells and this was augmented by PTPN2 knockdown (KD), although inhibition of MDA5 did not modify PIC-induced apoptosis. In contrast, MDA5 silencing decreased PIC-induced cytokine and chemokine expression, although inhibition of PTPN2 induced minor or no changes in these inflammatory mediators. These findings indicate that changes in MDA5 and PTPN2 expression modify β-cell responses to dsRNA. MDA5 regulates inflammatory signals, whereas PTPN2 may function as a defence mechanism against pro-apoptotic signals generated by dsRNA. These two candidate genes for T1D may thus modulate β-cell apoptosis and/or local release of inflammatory mediators in the course of a viral infection by acting, at least in part, at the pancreatic β-cell level.
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Affiliation(s)
- Maikel L Colli
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
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Cunha DA, Ladrière L, Ortis F, Igoillo-Esteve M, Gurzov EN, Lupi R, Marchetti P, Eizirik DL, Cnop M. Glucagon-like peptide-1 agonists protect pancreatic beta-cells from lipotoxic endoplasmic reticulum stress through upregulation of BiP and JunB. Diabetes 2009; 58:2851-62. [PMID: 19720788 PMCID: PMC2780890 DOI: 10.2337/db09-0685] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Chronic exposure of pancreatic beta-cells to saturated free fatty acids (FFAs) causes endoplasmic reticulum (ER) stress and apoptosis and may contribute to beta-cell loss in type 2 diabetes. Here, we evaluated the molecular mechanisms involved in the protection of beta-cells from lipotoxic ER stress by glucagon-like peptide (GLP)-1 agonists utilized in the treatment of type 2 diabetes. RESEARCH DESIGN AND METHODS INS-1E or fluorescence-activated cell sorter-purified primary rat beta-cells were exposed to oleate or palmitate with or without the GLP-1 agonist exendin-4 or forskolin. Cyclopiazonic acid was used as a synthetic ER stressor, while the activating transcription factor 4-C/EBP homologous protein branch was selectively activated with salubrinal. The ER stress signaling pathways modulated by GLP-1 agonists were studied by real-time PCR and Western blot. Knockdown by RNA interference was used to identify mediators of the antiapoptotic GLP-1 effects in the ER stress response and downstream mitochondrial cell death mechanisms. RESULTS Exendin-4 and forskolin protected beta-cells against FFAs via the induction of the ER chaperone BiP and the antiapoptotic protein JunB that mediate beta-cell survival under lipotoxic conditions. On the other hand, exendin-4 and forskolin protected against synthetic ER stressors by inactivating caspase 12 and upregulating Bcl-2 and X-chromosome-linked inhibitor of apoptosis protein that inhibit mitochondrial apoptosis. CONCLUSIONS These observations suggest that GLP-1 agonists increase in a context-dependent way the beta-cell defense mechanisms against different pathways involved in ER stress-induced apoptosis. The identification of the pathways modulated by GLP-1 agonists allows for targeted approaches to alleviate beta-cell ER stress in diabetes.
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Affiliation(s)
- Daniel A. Cunha
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Laurence Ladrière
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Fernanda Ortis
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Esteban N. Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Roberto Lupi
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, Pisa, Italy
| | - Décio L. Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Miriam Cnop
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
- Division of Endocrinology, Erasmus Hospital, Brussels, Belgium
- Corresponding author: Miriam Cnop,
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Abstract
Cytokines contribute to pancreatic β-cell apoptosis in type 1 diabetes (T1D) by modulation of β-cell gene expression networks. The transcription factor Activator Protein-1 (AP-1) is a key regulator of inflammation and apoptosis. We presently evaluated the function of the AP-1 subunit JunB in cytokine-mediated β-cell dysfunction and death. The cytokines IL-1β+IFN-γ induced an early and transitory upregulation of JunB by NF-κB activation. Knockdown of JunB by RNA interference increased cytokine-mediated expression of inducible nitric oxide synthase (iNOS) and endoplasmic reticulum (ER) stress markers, leading to increased apoptosis in an insulin-producing cell line (INS-1E) and in purified rat primary β-cells. JunB knockdown β-cells and junB−/− fibroblasts were also more sensitive to the chemical ER stressor cyclopiazonic acid (CPA). Conversely, adenoviral-mediated overexpression of JunB diminished iNOS and ER markers expression and protected β-cells from cytokine-induced cell death. These findings demonstrate a novel and unexpected role for JunB as a regulator of defense mechanisms against cytokine- and ER stress-mediated apoptosis.
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Affiliation(s)
- Esteban N. Gurzov
- Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Brussels, Belgium
- * E-mail:
| | - Fernanda Ortis
- Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Latifa Bakiri
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Erwin F. Wagner
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Decio L. Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Brussels, Belgium
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Gurzov EN, Nabha SM, Yamamoto H, Meng H, Scharovsky OG, Bonfil RD. Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line. BMC Cancer 2007; 7:184. [PMID: 17908302 PMCID: PMC2129098 DOI: 10.1186/1471-2407-7-184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 10/01/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite significant advancement in breast cancer therapy, there is a great need for a better understanding of the mechanisms involved in breast carcinogenesis and progression, as well as of the role of epigenetic contributions from stromal cells in mammary tumorigenesis. In this study, we isolated and characterized murine mammary tumor-derived epithelial and myofibroblast cell lines, and investigated the in vitro and in vivo effect of cellular soluble factors produced by the epithelial cell line on tumor cells. METHODS Morphology, immunophenotype, cytogenetics, invasiveness, and tumorigenicity of epithelial (LM-234ep) and myofibroblast (LM-234mf) cell lines isolated from two murine mammary adenocarcinomas with common ancestor were studied. The in vitro effects of LM-234ep conditioned medium on proliferation, cell cycle distribution, and expression of cell cycle proteins, were investigated in LM-234mf cells, mouse melanoma cells (B16-F10), and human cervical adenocarcinoma cells (HeLa). The in vivo anti-tumor activity of LM-234ep conditioned media was evaluated in subcutaneous tumors formed in nude mice by B16-F10 and HeLa cells. RESULTS LM-234ep cells were found to be cytokeratin positive and hipertriploid, whereas LM-234mf cells were alpha-smooth muscle actin positive and hypohexaploid. Chromosome aberrations were found in both cases. Only LM-234mf revealed to be invasive in vitro and to secrete active MMP-2, though neither of the cell types were able to produce progressing tumors. LM-234ep-derived factors were able to inhibit the in vitro growth of LM-234mf, B16-F10, and HeLa cells, inducing cell cycle arrest in G0/G1 phase. The administration of LM-234ep conditioned medium inhibited the growth of B16-F10 and HeLa tumors in nude mice. CONCLUSION Our data suggest the existence of epithelial cell variants with tumor suppressive properties within mammary tumors. To our knowledge, this is the first report showing antiproliferative and antineoplastic activities induced by tumor-derived epithelial cells.
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Affiliation(s)
- Esteban N Gurzov
- Department of Molecular Biology, Centro de Biología Molecular Severo Ochoa Universidad Autónoma de Madrid, Facultad de Ciencias, Madrid, Spain
| | - Sanaa M Nabha
- Departments of Urology and Pathology, Wayne State University School of Medicine and The Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA
| | - Hamilto Yamamoto
- Departments of Urology and Pathology, Wayne State University School of Medicine and The Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA
| | - Hong Meng
- Departments of Urology and Pathology, Wayne State University School of Medicine and The Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA
| | - O Graciela Scharovsky
- Instituto de Genética Experimental, School of Medical Sciences, University of Rosario, Rosario, Argentina
| | - R Daniel Bonfil
- Departments of Urology and Pathology, Wayne State University School of Medicine and The Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA
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Abstract
The activating protein-1 transcription factor, in particular the Jun proteins play critical roles in the regulation of cell proliferation and tumor progression. To study the potential clinical relevance of interfering with JunB expression, we generated retroviruses expressing short hairpin RNA. Reduction of JunB levels causes increased proliferation and tumorigenicity in wild-type murine fibroblasts, whereas in c-Jun knockout cells p53-independent cell cycle arrest and apoptosis are induced. Using melanoma-derived B16-F10 cancer cells the combination of JunB knockdown and c-Jun/JNK inactivation leads to cell cycle arrest and apoptosis-inducing factor-dependent apoptosis. Furthermore, the combined treatment extends survival of mice inoculated with the tumor cells. These results indicate that in the absence of c-Jun, JunB can act as a tumor promoter and inactivation of both, c-Jun and JunB, could provide a valuable strategy for antitumor intervention.
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Affiliation(s)
- E N Gurzov
- Department of Molecular Biology, Facultad de Ciencias, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
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Abstract
OBJECTIVES Cyclin E1 is expressed during the late G1 phase of the cell cycle and mediates the initiation of DNA synthesis by activating cyclin-dependent kinases 2 (CDK2). Abnormally high levels of cyclin E1 expression have frequently been found in cancer cells. Here, we investigate the effect of cyclin E1 knockdown on cancer cells. METHODS RNA interference, expressed from a DNA-based retroviral vector, was used to knockdown cyclin E1 in adenocarcinoma (HeLa), breast (MDA-MB-31) and glioblastoma (U-373-MG) cell lines and an explant from one glioma patient (GB-LP-2). RESULTS We have obtained very efficient depletion of cyclin E1 protein (over 80%) and considerable apoptotic induction (50-70%) after 96 hours post-infection. The ability of U-373-MG cells to induce tumor growth in nude mice was also abolished after cyclin E1 knockdown. DISCUSSION Our results indicate that retrovirus carrying the DNA to be transcribed into a short hairpin RNA (shRNA) against cyclin E1 could be used as a therapeutic agent for cancer therapy.
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Affiliation(s)
- Esteban N Gurzov
- Departament of Molecular Biology, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Facultad de Ciencias, Cantoblanco, Madrid 28049, Spain
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Pastrana E, Moreno-Flores MT, Gurzov EN, Avila J, Wandosell F, Diaz-Nido J. Genes associated with adult axon regeneration promoted by olfactory ensheathing cells: a new role for matrix metalloproteinase 2. J Neurosci 2006; 26:5347-59. [PMID: 16707787 PMCID: PMC6675307 DOI: 10.1523/jneurosci.1111-06.2006] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The molecular mechanisms used by olfactory ensheathing cells (OECs) to promote repair in the damaged adult mammalian CNS remain unknown. Thus, we used microarrays to analyze three OEC populations with different capacities to promote axonal regeneration in cultured rat retinal neurons. Gene expression in "long-term cultured OECs" that do not stimulate adult axonal outgrowth was compared with that of "primary olfactory ensheathing cells" and the immortalized OEC cell line TEG3. In this way, we identified a number of candidate genes that might play a role in promoting adult axonal regeneration. Among these genes, it was striking that both the matrix metalloproteinase 2 (MMP2) and an inhibitor of this protease were represented. The disruption of MMP2 activity in TEG3 cells impaired their capacity to trigger axon regeneration in cultured adult retinal neurons. Furthermore, the MMP2 protein was detected in grafts of OECs that elicited robust axonal regeneration in the injured spinal cord of adult rats in vivo. These data suggest that MMP2 does indeed participate in adult axonal regeneration induced by OECs.
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Abstract
Hec1 (highly expressed in cancer) plays an important role in chromosome segregation by interacting with a subset of checkpoint proteins that survey proper chromosome alignment and bipolar spindle attachment. In order to disrupt mitotic progression of tumor cell lines, we have used retrovirus and adenovirus vectors that inhibit Hec1 synthesis. Vector-expressed short hairpin RNAs (shRNAs) caused very efficient depletion of the target protein, cellular arrest and considerable mitotic catastrophe induction 96 h post infection in human cervix-adenocarcinoma (HeLa) and glioblastoma (U-373-MG) cell lines. Furthermore, adenocarcinomas induced in the flanks of nude mice show significant reduction in size compared with control when treated with either Hec1-shRNA retroviruses or adenoviruses. These results indicate that depletion of Hec1 could be used as a new strategy to block the dividing cell, and therefore against cancer.
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Affiliation(s)
- E N Gurzov
- Department of Molecular Biology, Centro de Biología Molecular 'Severo Ochoa', Universidad Autónoma de Madrid, Facultad de Ciencias, Cantoblanco, Madrid, Spain
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