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Selck C, Jhala G, De George DJ, Kwong CTJ, Christensen MK, Pappas EG, Liu X, Ge T, Trivedi P, Kallies A, Thomas HE, Kay TWH, Krishnamurthy B. Extraislet expression of islet antigen boosts T cell exhaustion to partially prevent autoimmune diabetes. Proc Natl Acad Sci U S A 2024; 121:e2315419121. [PMID: 38285952 PMCID: PMC10861925 DOI: 10.1073/pnas.2315419121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/21/2023] [Indexed: 01/31/2024] Open
Abstract
Persistent antigen exposure results in the differentiation of functionally impaired, also termed exhausted, T cells which are maintained by a distinct population of precursors of exhausted T (TPEX) cells. T cell exhaustion is well studied in the context of chronic viral infections and cancer, but it is unclear whether and how antigen-driven T cell exhaustion controls progression of autoimmune diabetes and whether this process can be harnessed to prevent diabetes. Using nonobese diabetic (NOD) mice, we show that some CD8+ T cells specific for the islet antigen, islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) displayed terminal exhaustion characteristics within pancreatic islets but were maintained in the TPEX cell state in peripheral lymphoid organs (PLO). More IGRP-specific T cells resided in the PLO than in islets. To examine the impact of extraislet antigen exposure on T cell exhaustion in diabetes, we generated transgenic NOD mice with inducible IGRP expression in peripheral antigen-presenting cells. Antigen exposure in the extraislet environment induced severely exhausted IGRP-specific T cells with reduced ability to produce interferon (IFN)γ, which protected these mice from diabetes. Our data demonstrate that T cell exhaustion induced by delivery of antigen can be harnessed to prevent autoimmune diabetes.
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Affiliation(s)
- Claudia Selck
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Gaurang Jhala
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
| | - David J. De George
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Chun-Ting J. Kwong
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Marie K. Christensen
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Evan G. Pappas
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
| | - Xin Liu
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Tingting Ge
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Prerak Trivedi
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Axel Kallies
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC3000, Australia
| | - Helen E. Thomas
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Thomas W. H. Kay
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
| | - Balasubramanian Krishnamurthy
- Immunology and Diabetes Unit, St. Vincent’s Institute, Fitzroy, VIC3065, Australia
- Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Fitzroy, VIC3065, Australia
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Pappas EG, Kershaw MH, Slaney CY. Insights into Cancer Immunotherapies: Recent Breakthroughs, Opportunities, and Challenges. Cancers (Basel) 2023; 15:cancers15041322. [PMID: 36831663 PMCID: PMC9954646 DOI: 10.3390/cancers15041322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
This Special Issue reminds us that, although incredible developments have occurred in the field of cancer immunotherapy, there is still plenty of room for improvement [...].
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Affiliation(s)
- Evan G. Pappas
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael H. Kershaw
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Clare Y. Slaney
- Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence:
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Ge T, Phung A, Jhala G, Trivedi P, Principe N, De George DJ, Pappas EG, Litwak S, Sanz‐Villanueva L, Catterall T, Fynch S, Boon L, Kay TW, Chee J, Krishnamurthy B, Thomas HE. Diabetes induced by checkpoint inhibition in nonobese diabetic mice can be prevented or reversed by a JAK1/JAK2 inhibitor. Clin Transl Immunology 2022; 11:e1425. [PMID: 36325490 PMCID: PMC9618467 DOI: 10.1002/cti2.1425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 04/25/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES Immune checkpoint inhibitors have achieved clinical success in cancer treatment, but this treatment causes immune-related adverse events, including type 1 diabetes (T1D). Our aim was to test whether a JAK1/JAK2 inhibitor, effective at treating spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice, can prevent diabetes secondary to PD-L1 blockade. METHODS Anti-PD-L1 antibody was injected into NOD mice to induce diabetes, and JAK1/JAK2 inhibitor LN3103801 was administered by oral gavage to prevent diabetes. Flow cytometry was used to study T cells and beta cells. Mesothelioma cells were inoculated into BALB/c mice to induce a transplantable tumour model. RESULTS Anti-PD-L1-induced diabetes was associated with increased immune cell infiltration in the islets and upregulated MHC class I on islet cells. Anti-PD-L1 administration significantly increased islet T cell proliferation and islet-specific CD8+ T cell numbers in peripheral lymphoid organs. JAK1/JAK2 inhibitor treatment blocked IFNγ-mediated MHC class I upregulation on beta cells and T cell proliferation mediated by cytokines that use the common γ chain receptor. As a result, anti-PD-L1-induced diabetes was prevented by JAK1/JAK2 inhibitor administered before or after checkpoint inhibitor therapy. Diabetes was also reversed when the JAK1/JAK2 inhibitor was administered after the onset of anti-PD-L1-induced hyperglycaemia. Furthermore, JAK1/JAK2 inhibitor intervention after checkpoint inhibitors did not reverse or abrogate the antitumour effects in a transplantable tumour model. CONCLUSION A JAK1/JAK2 inhibitor can prevent and reverse anti-PD-L1-induced diabetes by blocking IFNγ and γc cytokine activities. Our study provides preclinical validation of JAK1/JAK2 inhibitor use in checkpoint inhibitor-induced diabetes.
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Affiliation(s)
- Tingting Ge
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
| | - Amber‐Lee Phung
- National Centre for Asbestos Related Diseases, Institute for Respiratory HealthThe University of Western AustraliaCrawleyWAAustralia
| | - Gaurang Jhala
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | - Prerak Trivedi
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | - Nicola Principe
- National Centre for Asbestos Related Diseases, Institute for Respiratory HealthThe University of Western AustraliaCrawleyWAAustralia
| | - David J De George
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
| | - Evan G Pappas
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | - Sara Litwak
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | - Laura Sanz‐Villanueva
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
| | - Tara Catterall
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | - Stacey Fynch
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia
| | | | - Thomas W Kay
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
| | - Jonathan Chee
- National Centre for Asbestos Related Diseases, Institute for Respiratory HealthThe University of Western AustraliaCrawleyWAAustralia
| | - Balasubramanian Krishnamurthy
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
| | - Helen E Thomas
- Immunology and Diabetes UnitSt Vincent's InstituteFitzroyVICAustralia,The University of MelbourneParkvilleVICAustralia
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Jhala G, Krishnamurthy B, Brodnicki TC, Ge T, Akazawa S, Selck C, Trivedi PM, Pappas EG, Mackin L, Principe N, Brémaud E, De George DJ, Boon L, Smyth I, Chee J, Kay TWH, Thomas HE. Interferons limit autoantigen-specific CD8 + T-cell expansion in the non-obese diabetic mouse. Cell Rep 2022; 39:110747. [PMID: 35476975 DOI: 10.1016/j.celrep.2022.110747] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 01/24/2022] [Accepted: 04/07/2022] [Indexed: 11/24/2022] Open
Abstract
Interferon gamma (IFNγ) is a proinflammatory cytokine implicated in autoimmune diseases. However, deficiency or neutralization of IFNγ is ineffective in reducing disease. We characterize islet antigen-specific T cells in non-obese diabetic (NOD) mice lacking all three IFN receptor genes. Diabetes is minimally affected, but at 125 days of age, antigen-specific CD8+ T cells, quantified using major histocompatibility complex class I tetramers, are present in 10-fold greater numbers in Ifngr-mutant NOD mice. T cells from Ifngr-mutant mice have increased proliferative responses to interleukin-2 (IL-2). They also have reduced phosphorylated STAT1 and its target gene, suppressor of cytokine signaling 1 (SOCS-1). IFNγ controls the expansion of antigen-specific CD8+ T cells by mechanisms which include increased SOCS-1 expression that regulates IL-2 signaling. The expanded CD8+ T cells are likely to contribute to normal diabetes progression despite reduced inflammation in Ifngr-mutant mice.
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Affiliation(s)
- Gaurang Jhala
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Balasubramanian Krishnamurthy
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia
| | - Thomas C Brodnicki
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia; Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Tingting Ge
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia
| | - Satoru Akazawa
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Claudia Selck
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Prerak M Trivedi
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Evan G Pappas
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Leanne Mackin
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - Nicola Principe
- National Centre of Asbestos-Related Diseases, Institute of Respiratory Health, School of Biomedical Science, University of Western Australia, Nedlands, WA 6009, Australia
| | - Erwan Brémaud
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia
| | - David J De George
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia
| | - Louis Boon
- Polpharma Biologics, 3584 CM Utrecht, the Netherlands
| | - Ian Smyth
- Australian Phenomics Network, Monash Genome Modification Platform, Monash University, Clayton, VIC 3800, Australia; Development and Stem Cells Program, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC 3800, Australia
| | - Jonathan Chee
- National Centre of Asbestos-Related Diseases, Institute of Respiratory Health, School of Biomedical Science, University of Western Australia, Nedlands, WA 6009, Australia
| | - Thomas W H Kay
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia.
| | - Helen E Thomas
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC 3065, Australia; Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC 3065, Australia
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Yang CH, Ann-Onda D, Lin X, Fynch S, Nadarajah S, Pappas EG, Liu X, Scott JW, Oakhill JS, Galic S, Shi Y, Moreno-Asso A, Smith C, Loudovaris T, Levinger I, Eizirik DL, Laybutt DR, Herzog H, Thomas HE, Loh K. Neuropeptide Y1 receptor antagonism protects β-cells and improves glycemic control in type 2 diabetes. Mol Metab 2021; 55:101413. [PMID: 34890851 PMCID: PMC8733231 DOI: 10.1016/j.molmet.2021.101413] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 09/17/2021] [Revised: 11/12/2021] [Accepted: 11/30/2021] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Loss of functional β-cell mass is a key factor contributing to poor glycemic control in advanced type 2 diabetes (T2D). We have previously reported that the inhibition of the neuropeptide Y1 receptor improves the islet transplantation outcome in type 1 diabetes (T1D). The aim of this study was to identify the pathophysiological role of the neuropeptide Y (NPY) system in human T2D and further evaluate the therapeutic potential of using the Y1 receptor antagonist BIBO3304 to improve β-cell function and survival in T2D. METHODS The gene expression of the NPY system in human islets from nondiabetic subjects and subjects with T2D was determined and correlated with the stimulation index. The glucose-lowering and β-cell-protective effects of BIBO3304, a selective orally bioavailable Y1 receptor antagonist, in high-fat diet (HFD)/multiple low-dose streptozotocin (STZ)-induced and genetically obese (db/db) T2D mouse models were assessed. RESULTS In this study, we identified a more than 2-fold increase in NPY1R and its ligand, NPY mRNA expression in human islets from subjects with T2D, which was significantly associated with reduced insulin secretion. Consistently, the pharmacological inhibition of Y1 receptors by BIBO3304 significantly protected β cells from dysfunction and death under multiple diabetogenic conditions in islets. In a preclinical study, we demonstrated that the inhibition of Y1 receptors by BIBO3304 led to reduced adiposity and enhanced insulin action in the skeletal muscle. Importantly, the Y1 receptor antagonist BIBO3304 treatment also improved β-cell function and preserved functional β-cell mass, thereby resulting in better glycemic control in both HFD/multiple low-dose STZ-induced and db/db T2D mice. CONCLUSIONS Our results revealed a novel causal link between increased islet NPY-Y1 receptor gene expression and β-cell dysfunction and failure in human T2D, contributing to the understanding of the pathophysiology of T2D. Furthermore, our results demonstrate that the inhibition of the Y1 receptor by BIBO3304 represents a potential β-cell-protective therapy for improving functional β-cell mass and glycemic control in T2D.
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Affiliation(s)
- Chieh-Hsin Yang
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia.
| | - Danise Ann-Onda
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia
| | - Xuzhu Lin
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia
| | - Stacey Fynch
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia
| | | | - Evan G Pappas
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia
| | - Xin Liu
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia
| | - John W Scott
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, 3000, Australia; The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, 3052, Australia
| | - Jonathan S Oakhill
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, 3000, Australia; Department of Medicine, University of Melbourne, Fitzroy, VIC, 3065, Australia
| | - Sandra Galic
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Department of Medicine, University of Melbourne, Fitzroy, VIC, 3065, Australia
| | - Yanchuan Shi
- Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Alba Moreno-Asso
- Institute of Health and Sport (IHES), Victoria University, Footscray, VIC, Australia; Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St Albans, VIC, Australia
| | - Cassandra Smith
- Institute of Health and Sport (IHES), Victoria University, Footscray, VIC, Australia; Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St Albans, VIC, Australia
| | - Thomas Loudovaris
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Department of Medicine, University of Melbourne, Fitzroy, VIC, 3065, Australia
| | - Itamar Levinger
- Institute of Health and Sport (IHES), Victoria University, Footscray, VIC, Australia; Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St Albans, VIC, Australia
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Universite Libre de Bruxelles (ULB), Brussels, Belgium; Indiana Biosciences Research Institute (IBRI), Indianapolis, IN, USA
| | - D Ross Laybutt
- Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Herbert Herzog
- Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, 2010, Australia; Faculty of Medicine, UNSW Australia, Sydney, 2052, Australia
| | - Helen E Thomas
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Department of Medicine, University of Melbourne, Fitzroy, VIC, 3065, Australia
| | - Kim Loh
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia; Department of Medicine, University of Melbourne, Fitzroy, VIC, 3065, Australia.
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6
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Akazawa S, Mackin L, Jhala G, Fynch S, Catterall T, Selck C, Graham KL, Krishnamurthy B, Pappas EG, Kwong CTJ, Sutherland APR, Kay TWH, Brodnicki TC, Thomas HE. Deficiency of the innate immune adaptor STING promotes autoreactive T cell expansion in NOD mice. Diabetologia 2021; 64:878-889. [PMID: 33483762 DOI: 10.1007/s00125-020-05378-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 07/29/2020] [Accepted: 11/17/2020] [Indexed: 01/07/2023]
Abstract
AIMS/HYPOTHESIS Stimulator of IFN genes (STING) is a central hub for cytosolic nucleic acid sensing and its activation results in upregulation of type I IFN production in innate immune cells. A type I IFN gene signature seen before the onset of type 1 diabetes has been suggested as a driver of disease initiation both in humans and in the NOD mouse model. A possible source of type I IFN is through activation of the STING pathway. Recent studies suggest that STING also has antiproliferative and proapoptotic functions in T cells that are independent of IFN. To investigate whether STING is involved in autoimmune diabetes, we examined the impact of genetic deletion of STING in NOD mice. METHODS CRISPR/Cas9 gene editing was used to generate STING-deficient NOD mice. Quantitative real-time PCR was used to assess the level of type I IFN-regulated genes in islets from wild-type and STING-deficient NOD mice. The number of islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)206-214-specific CD8+ T cells was determined by magnetic bead-based MHC tetramer enrichment and flow cytometry. The incidence of spontaneous diabetes and diabetes after adoptive transfer of T cells was determined. RESULTS STING deficiency partially attenuated the type I IFN gene signature in islets but did not suppress insulitis. STING-deficient NOD mice accumulated an increased number of IGRP206-214-specific CD8+ T cells (2878 ± 642 cells in NOD.STING-/- mice and 728.8 ± 196 cells in wild-type NOD mice) in peripheral lymphoid tissue, associated with a higher incidence of spontaneous diabetes (95.5% in NOD.STING-/- mice and 86.2% in wild-type NOD mice). Splenocytes from STING-deficient mice rapidly induced diabetes after adoptive transfer into irradiated NOD recipients (median survival 75 days for NOD recipients of NOD.STING-/- mouse splenocytes and 121 days for NOD recipients of NOD mouse splenocytes). CONCLUSIONS/INTERPRETATION Data suggest that sensing of endogenous nucleic acids through the STING pathway may be partially responsible for the type I IFN gene signature but not autoimmunity in NOD mice. Our results show that the STING pathway may play an unexpected intrinsic role in suppressing the number of diabetogenic T cells.
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Affiliation(s)
- Satoru Akazawa
- St Vincent's Institute, Fitzroy, VIC, Australia
- Department of Endocrinology and Metabolism, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | | | | | | | | | | | - Kate L Graham
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Balasubramanian Krishnamurthy
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | | | - Chun-Ting J Kwong
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Andrew P R Sutherland
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Thomas W H Kay
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Thomas C Brodnicki
- St Vincent's Institute, Fitzroy, VIC, Australia
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Helen E Thomas
- St Vincent's Institute, Fitzroy, VIC, Australia.
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia.
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7
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Jhala G, Selck C, Chee J, Kwong CTJ, Pappas EG, Thomas HE, Kay TWH, Krishnamurthy B. Tolerance to Proinsulin-1 Reduces Autoimmune Diabetes in NOD Mice. Front Immunol 2021; 12:645817. [PMID: 33841427 PMCID: PMC8027244 DOI: 10.3389/fimmu.2021.645817] [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: 12/24/2020] [Accepted: 03/08/2021] [Indexed: 11/30/2022] Open
Abstract
T-cell responses to insulin and its precursor proinsulin are central to islet autoimmunity in humans and non-obese diabetic (NOD) mice that spontaneously develop autoimmune diabetes. Mice have two proinsulin genes proinsulin -1 and 2 that are differentially expressed, with predominant proinsulin-2 expression in the thymus and proinsulin-1 in islet beta-cells. In contrast to proinsulin-2, proinsulin-1 knockout NOD mice are protected from autoimmune diabetes. This indicates that proinsulin-1 epitopes in beta-cells maybe preferentially targeted by autoreactive T cells. To study the contribution of proinsulin-1 reactive T cells in autoimmune diabetes, we generated transgenic NOD mice with tetracycline-regulated expression of proinsulin-1 in antigen presenting cells (TIP-1 mice) with an aim to induce immune tolerance. TIP-1 mice displayed a significantly reduced incidence of spontaneous diabetes, which was associated with reduced severity of insulitis and insulin autoantibody development. Antigen experienced proinsulin specific T cells were significantly reduced in in TIP-1 mice indicating immune tolerance. Moreover, T cells from TIP-1 mice expressing proinsulin-1 transferred diabetes at a significantly reduced frequency. However, proinsulin-1 expression in APCs had minimal impact on the immune responses to the downstream antigen islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) and did not prevent diabetes in NOD 8.3 mice with a pre-existing repertoire of IGRP reactive T cells. Thus, boosting immune tolerance to proinsulin-1 partially prevents islet-autoimmunity. This study further extends the previously established role of proinsulin-1 epitopes in autoimmune diabetes in NOD mice.
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Affiliation(s)
- Gaurang Jhala
- St. Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, The University of Melbourne, St Vincent's Hospital, Fitzroy, VIC, Australia
| | | | - Jonathan Chee
- National Centre for Asbestos Related Diseases, Institute of Respiratory Health, University of Western Australia, Perth, WA, Australia.,School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | | | | | - Helen E Thomas
- St. Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, The University of Melbourne, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Thomas W H Kay
- St. Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, The University of Melbourne, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Balasubramanian Krishnamurthy
- St. Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, The University of Melbourne, St Vincent's Hospital, Fitzroy, VIC, Australia
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8
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Ge T, Jhala G, Fynch S, Akazawa S, Litwak S, Pappas EG, Catterall T, Vakil I, Long AJ, Olson LM, Krishnamurthy B, Kay TW, Thomas HE. The JAK1 Selective Inhibitor ABT 317 Blocks Signaling Through Interferon-γ and Common γ Chain Cytokine Receptors to Reverse Autoimmune Diabetes in NOD Mice. Front Immunol 2020; 11:588543. [PMID: 33343569 PMCID: PMC7746546 DOI: 10.3389/fimmu.2020.588543] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 07/29/2020] [Accepted: 11/04/2020] [Indexed: 01/31/2023] Open
Abstract
Cytokines that signal through the JAK-STAT pathway, such as interferon-γ (IFN-γ) and common γ chain cytokines, contribute to the destruction of insulin-secreting β cells by CD8+ T cells in type 1 diabetes (T1D). We previously showed that JAK1/JAK2 inhibitors reversed autoimmune insulitis in non-obese diabetic (NOD) mice and also blocked IFN-γ mediated MHC class I upregulation on β cells. Blocking interferons on their own does not prevent diabetes in knockout NOD mice, so we tested whether JAK inhibitor action on signaling downstream of common γ chain cytokines, including IL-2, IL-7 IL-15, and IL-21, may also affect the progression of diabetes in NOD mice. Common γ chain cytokines activate JAK1 and JAK3 to regulate T cell proliferation. We used a JAK1-selective inhibitor, ABT 317, to better understand the specific role of JAK1 signaling in autoimmune diabetes. ABT 317 reduced IL-21, IL-2, IL-15 and IL-7 signaling in T cells and IFN-γ signaling in β cells, but ABT 317 did not affect GM-CSF signaling in granulocytes. When given in vivo to NOD mice, ABT 317 reduced CD8+ T cell proliferation as well as the number of KLRG+ effector and CD44hiCD62Llo effector memory CD8+ T cells in spleen. ABT 317 also prevented MHC class I upregulation on β cells. Newly diagnosed diabetes was reversed in 94% NOD mice treated twice daily with ABT 317 while still on treatment at 40 days and 44% remained normoglycemic after a further 60 days from discontinuing the drug. Our results indicate that ABT 317 blocks common γ chain cytokines in lymphocytes and interferons in lymphocytes and β cells and are thus more effective against diabetes pathogenesis than IFN-γ receptor deficiency alone. Our studies suggest use of this class of drug for the treatment of type 1 diabetes.
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Affiliation(s)
- Tingting Ge
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Gaurang Jhala
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Stacey Fynch
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Satoru Akazawa
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Sara Litwak
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Evan G Pappas
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Tara Catterall
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia
| | - Ishan Vakil
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Andrew J Long
- AbbVie Bioresearch Center, Worcester, MA, United States
| | - Lisa M Olson
- AbbVie Bioresearch Center, Worcester, MA, United States
| | - Balasubramanian Krishnamurthy
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Thomas W Kay
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
| | - Helen E Thomas
- Immunology and Diabetes Unit, St Vincent's Institute, Fitzroy, VIC, Australia.,Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, VIC, Australia
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9
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Bensellam M, Shi YC, Chan JY, Laybutt DR, Chae H, Abou-Samra M, Pappas EG, Thomas HE, Gilon P, Jonas JC. Metallothionein 1 negatively regulates glucose-stimulated insulin secretion and is differentially expressed in conditions of beta cell compensation and failure in mice and humans. Diabetologia 2019; 62:2273-2286. [PMID: 31624901 DOI: 10.1007/s00125-019-05008-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 06/11/2019] [Accepted: 08/13/2019] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS The mechanisms responsible for beta cell compensation in obesity and for beta cell failure in type 2 diabetes are poorly defined. The mRNA levels of several metallothionein (MT) genes are upregulated in islets from individuals with type 2 diabetes, but their role in beta cells is not clear. Here we examined: (1) the temporal changes of islet Mt1 and Mt2 gene expression in mouse models of beta cell compensation and failure; and (2) the role of Mt1 and Mt2 in beta cell function and glucose homeostasis in mice. METHODS Mt1 and Mt2 expression was assessed in islets from: (1) control lean (chow diet-fed) and diet-induced obese (high-fat diet-fed for 6 weeks) mice; (2) mouse models of diabetes (db/db mice) at 6 weeks old (prediabetes) and 16 weeks old (after diabetes onset) and age-matched db/+ (control) mice; and (3) obese non-diabetic ob/ob mice (16-week-old) and age-matched ob/+ (control) mice. MT1E, MT1X and MT2A expression was assessed in islets from humans with and without type 2 diabetes. Mt1-Mt2 double-knockout (KO) mice, transgenic mice overexpressing Mt1 under the control of its natural promoter (Tg-Mt1) and corresponding control mice were also studied. In MIN6 cells, MT1 and MT2 were inhibited by small interfering RNAs. mRNA levels were assessed by real-time RT-PCR, plasma insulin and islet MT levels by ELISA, glucose tolerance by i.p. glucose tolerance tests and overnight fasting-1 h refeeding tests, insulin tolerance by i.p. insulin tolerance tests, insulin secretion by RIA, cytosolic free Ca2+ concentration with Fura-2 leakage resistant (Fura-2 LR), cytosolic free Zn2+ concentration with Fluozin-3, and NAD(P)H by autofluorescence. RESULTS Mt1 and Mt2 mRNA levels were reduced in islets of murine models of beta cell compensation, whereas they were increased in diabetic db/db mice. In humans, MT1X mRNA levels were significantly upregulated in islets from individuals with type 2 diabetes in comparison with non-diabetic donors, while MT1E and MT2A mRNA levels were unchanged. Ex vivo, islet Mt1 and Mt2 mRNA and MT1 and MT2 protein levels were downregulated after culture with glucose at 10-30 mmol/l vs 2-5 mmol/l, in association with increased insulin secretion. In human islets, mRNA levels of MT1E, MT1X and MT2A were downregulated by stimulation with physiological and supraphysiological levels of glucose. In comparison with wild-type (WT) mice, Mt1-Mt2 double-KO mice displayed improved glucose tolerance in association with increased insulin levels and enhanced insulin release from isolated islets. In contrast, isolated islets from Tg-Mt1 mice displayed impaired glucose-stimulated insulin secretion (GSIS). In both Mt1-Mt2 double-KO and Tg-Mt1 models, the changes in GSIS occurred despite similar islet insulin content, rises in cytosolic free Ca2+ concentration and NAD(P)H levels, or intracellular Zn2+ concentration vs WT mice. In MIN6 cells, knockdown of MT1 but not MT2 potentiated GSIS, suggesting that Mt1 rather than Mt2 affects beta cell function. CONCLUSIONS/INTERPRETATION These findings implicate Mt1 as a negative regulator of insulin secretion. The downregulation of Mt1 is associated with beta cell compensation in obesity, whereas increased Mt1 accompanies beta cell failure and type 2 diabetes.
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Affiliation(s)
- Mohammed Bensellam
- Pôle d'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 55 - B1.55.06, B-1200, Brussels, Belgium.
| | - Yan-Chuan Shi
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, Australia
| | - Jeng Yie Chan
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, Australia
| | - D Ross Laybutt
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, UNSW Sydney, Sydney, New South Wales, Australia
| | - Heeyoung Chae
- Pôle d'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 55 - B1.55.06, B-1200, Brussels, Belgium
| | - Michel Abou-Samra
- Pôle d'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 55 - B1.55.06, B-1200, Brussels, Belgium
| | - Evan G Pappas
- St Vincent's Institute, Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Helen E Thomas
- St Vincent's Institute, Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Patrick Gilon
- Pôle d'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 55 - B1.55.06, B-1200, Brussels, Belgium
| | - Jean-Christophe Jonas
- Pôle d'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Avenue Hippocrate 55 - B1.55.06, B-1200, Brussels, Belgium.
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10
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Mollah ZUA, Quah HS, Graham KL, Jhala G, Krishnamurthy B, Dharma JFM, Chee J, Trivedi PM, Pappas EG, Mackin L, Chu EPF, Akazawa S, Fynch S, Hodson C, Deans AJ, Trapani JA, Chong MMW, Bird PI, Brodnicki TC, Thomas HE, Kay TWH. Granzyme A Deficiency Breaks Immune Tolerance and Promotes Autoimmune Diabetes Through a Type I Interferon-Dependent Pathway. Diabetes 2017; 66:3041-3050. [PMID: 28733313 DOI: 10.2337/db17-0517] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 05/02/2017] [Accepted: 07/13/2017] [Indexed: 11/13/2022]
Abstract
Granzyme A is a protease implicated in the degradation of intracellular DNA. Nucleotide complexes are known triggers of systemic autoimmunity, but a role in organ-specific autoimmune disease has not been demonstrated. To investigate whether such a mechanism could be an endogenous trigger for autoimmunity, we examined the impact of granzyme A deficiency in the NOD mouse model of autoimmune diabetes. Granzyme A deficiency resulted in an increased incidence in diabetes associated with accumulation of ssDNA in immune cells and induction of an interferon response in pancreatic islets. Central tolerance to proinsulin in transgenic NOD mice was broken on a granzyme A-deficient background. We have identified a novel endogenous trigger for autoimmune diabetes and an in vivo role for granzyme A in maintaining immune tolerance.
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Affiliation(s)
| | - Hong Sheng Quah
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, 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
| | - Gaurang Jhala
- 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
| | - Joanna Francisca M Dharma
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Jonathan Chee
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Prerak M Trivedi
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Evan G Pappas
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | - Leanne Mackin
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | - Edward P F Chu
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | | | - Stacey Fynch
- St. Vincent's Institute, Fitzroy, Victoria, Australia
| | | | - Andrew J Deans
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Joseph A Trapani
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Mark M W Chong
- St. Vincent's Institute, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Phillip I Bird
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Thomas C Brodnicki
- 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 W H Kay
- 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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11
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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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12
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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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