1
|
Zammit NW, Wong YY, Walters SN, Warren J, Barry SC, Grey ST. RELA governs a network of islet-specific metabolic genes necessary for beta cell function. Diabetologia 2023; 66:1516-1531. [PMID: 37311878 PMCID: PMC10317895 DOI: 10.1007/s00125-023-05931-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/14/2023] [Indexed: 06/15/2023]
Abstract
AIMS/HYPOTHESIS NF-κB activation unites metabolic and inflammatory responses in many diseases yet less is known about the role that NF-κB plays in normal metabolism. In this study we investigated how RELA impacts the beta cell transcriptional landscape and provides network control over glucoregulation. METHODS We generated novel mouse lines harbouring beta cell-specific deletion of either the Rela gene, encoding the canonical NF-κB transcription factor p65 (βp65KO mice), or the Ikbkg gene, encoding the NF-κB essential modulator NEMO (βNEMOKO mice), as well as βA20Tg mice that carry beta cell-specific and forced transgenic expression of the NF-κB-negative regulator gene Tnfaip3, which encodes the A20 protein. Mouse studies were complemented by bioinformatics analysis of human islet chromatin accessibility (assay for transposase-accessible chromatin with sequencing [ATAC-seq]), promoter capture Hi-C (pcHi-C) and p65 binding (chromatin immunoprecipitation-sequencing [ChIP-seq]) data to investigate genome-wide control of the human beta cell metabolic programme. RESULTS Rela deficiency resulted in complete loss of stimulus-dependent inflammatory gene upregulation, consistent with its known role in governing inflammation. However, Rela deletion also rendered mice glucose intolerant because of functional loss of insulin secretion. Glucose intolerance was intrinsic to beta cells as βp65KO islets failed to secrete insulin ex vivo in response to a glucose challenge and were unable to restore metabolic control when transplanted into secondary chemical-induced hyperglycaemic recipients. Maintenance of glucose tolerance required Rela but was independent of classical NF-κB inflammatory cascades, as blocking NF-κB signalling in vivo by beta cell knockout of Ikbkg (NEMO), or beta cell overexpression of Tnfaip3 (A20), did not cause severe glucose intolerance. Thus, basal p65 activity has an essential and islet-intrinsic role in maintaining normal glucose homeostasis. Genome-wide bioinformatic mapping revealed the presence of p65 binding sites in the promoter regions of specific metabolic genes and in the majority of islet enhancer hubs (~70% of ~1300 hubs), which are responsible for shaping beta cell type-specific gene expression programmes. Indeed, the islet-specific metabolic genes Slc2a2, Capn9 and Pfkm identified within the large network of islet enhancer hub genes showed dysregulated expression in βp65KO islets. CONCLUSIONS/INTERPRETATION These data demonstrate an unappreciated role for RELA as a regulator of islet-specific transcriptional programmes necessary for the maintenance of healthy glucose metabolism. These findings have clinical implications for the use of anti-inflammatories, which influence NF-κB activation and are associated with diabetes.
Collapse
Affiliation(s)
- Nathan W Zammit
- Transplantation Immunology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Department of Immunology, Harvard Medical School, Boston, MA, USA
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Ying Ying Wong
- Robinson Research Institute, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Stacey N Walters
- Transplantation Immunology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Joanna Warren
- Transplantation Immunology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Simon C Barry
- Robinson Research Institute, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Shane T Grey
- Transplantation Immunology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.
- Translation Science Pillar, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney, NSW, Australia.
| |
Collapse
|
2
|
Zammit NW, McDowell J, Warren J, Muskovic W, Gamble J, Shi YC, Kaczorowski D, Chan CL, Powell J, Ormandy C, Brown D, Oakes SR, Grey ST. TNFAIP3 Reduction-of-Function Drives Female Infertility and CNS Inflammation. Front Immunol 2022; 13:811525. [PMID: 35464428 PMCID: PMC9027572 DOI: 10.3389/fimmu.2022.811525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/21/2022] [Indexed: 11/17/2022] Open
Abstract
Women with autoimmune and inflammatory aetiologies can exhibit reduced fecundity. TNFAIP3 is a master negative regulator of inflammation, and has been linked to many inflammatory conditions by genome wide associations studies, however its role in fertility remains unknown. Here we show that mice harbouring a mild Tnfaip3 reduction-of-function coding variant (Tnfaip3I325N) that reduces the threshold for inflammatory NF-κB activation, exhibit reduced fecundity. Sub-fertility in Tnfaip3I325N mice is associated with irregular estrous cycling, low numbers of ovarian secondary follicles, impaired mammary gland development and insulin resistance. These pathological features are associated with infertility in human subjects. Transplantation of Tnfaip3I325N ovaries, mammary glands or pancreatic islets into wild-type recipients rescued estrous cycling, mammary branching and hyperinsulinemia respectively, pointing towards a cell-extrinsic hormonal mechanism. Examination of hypothalamic brain sections revealed increased levels of microglial activation with reduced levels of luteinizing hormone. TNFAIP3 coding variants may offer one contributing mechanism for the cause of sub-fertility observed across otherwise healthy populations as well as for the wide variety of auto-inflammatory conditions to which TNFAIP3 is associated. Further, TNFAIP3 represents a molecular mechanism that links heightened immunity with neuronal inflammatory homeostasis. These data also highlight that tuning-up immunity with TNFAIP3 comes with the potentially evolutionary significant trade-off of reduced fertility.
Collapse
Affiliation(s)
- Nathan W. Zammit
- Immunity and Inflammation Theme, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- *Correspondence: Nathan W. Zammit, ; Shane T. Grey,
| | - Joseph McDowell
- Immunity and Inflammation Theme, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Joanna Warren
- Immunity and Inflammation Theme, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Walter Muskovic
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Joanne Gamble
- Centre for NSW Health Pathology, Institute of Clinical Pathology And Medical Research, Westmead Hospital, Westmead, NSW, Australia
| | - Yan-Chuan Shi
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Dominik Kaczorowski
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Chia-Ling Chan
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Joseph Powell
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Chris Ormandy
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - David Brown
- Centre for NSW Health Pathology, Institute of Clinical Pathology And Medical Research, Westmead Hospital, Westmead, NSW, Australia
| | - Samantha R. Oakes
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Shane T. Grey
- Immunity and Inflammation Theme, Garvan Institute of Medical Research, Sydney, NSW, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Translation Science Pillar, Garvan Institute of Medical Research, Sydney, NSW, Australia
- *Correspondence: Nathan W. Zammit, ; Shane T. Grey,
| |
Collapse
|
3
|
Zammit NW, Seeberger KL, Zamerli J, Walters SN, Lisowski L, Korbutt GS, Grey ST. Selection of a novel AAV2/TNFAIP3 vector for local suppression of islet xenograft inflammation. Xenotransplantation 2020; 28:e12669. [PMID: 33316848 DOI: 10.1111/xen.12669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/24/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Neonatal porcine islets (NPIs) can restore glucose control in mice, pigs, and non-human primates, representing a potential abundant alternative islet supply for clinical beta cell replacement therapy. However, NPIs are vulnerable to inflammatory insults that could be overcome with genetic modifications. Here, we demonstrate in a series of proof-of-concept experiments the potential of the cytoplasmic ubiquitin-editing protein A20, encoded by the TNFAIP3 gene, as an NPI cytoprotective gene. METHODS We forced A20 expression in NPI grafts using a recombinant adenovirus 5 (Ad5) vector and looked for impact on TNF-stimulated NF-κB activation and NPI graft function. As adeno-associated vectors (AAV) are clinically preferred vectors but exhibit poor transduction efficacy in NPIs, we next screened a series of AAV serotypes under different transduction protocols for their ability achieve high transduction efficiency and suppress NPI inflammation without impacting NPI maturation. RESULTS Forcing the expression of A20 in NPI with Ad5 vector blocked NF-κB activation by inhibiting IκBα phosphorylation and degradation, and reduced the induction of pro-inflammatory genes Cxcl10 and Icam1. A20-expressing NPIs also exhibited superior functional capacity when transplanted into diabetic immunodeficient recipient mice, evidenced by a more rapid return to euglycemia and improved GTT compared to unmodified NPI grafts. We found AAV2 combined with a 14-day culture period maximized NPI transduction efficiency (>70% transduction rate), and suppressed NF-κB-dependent gene expression without adverse impact upon NPI maturation. CONCLUSION We report a new protocol that allows for high-efficiency genetic modification of NPIs, which can be utilized to introduce candidate genes without the need for germline engineering. This approach would be suitable for preclinical and clinical testing of beneficial molecules. We also report for the first time that A20 is cytoprotective for NPI, such that A20 gene therapy could aid the clinical development of NPIs for beta cell replacement.
Collapse
Affiliation(s)
- Nathan W Zammit
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Sydney, NSW, Australia
| | | | - Jad Zamerli
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Stacey N Walters
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Leszek Lisowski
- Translational Vectorology Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia.,Military Institute of Medicine, Laboratory of Molecular Oncology and Innovative Therapies, Warsaw, Poland
| | | | - Shane T Grey
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Sydney, NSW, Australia
| |
Collapse
|
4
|
Aksoy YA, Yang B, Chen W, Hung T, Kuchel RP, Zammit NW, Grey ST, Goldys EM, Deng W. Spatial and Temporal Control of CRISPR-Cas9-Mediated Gene Editing Delivered via a Light-Triggered Liposome System. ACS Appl Mater Interfaces 2020; 12:52433-52444. [PMID: 33174413 DOI: 10.1021/acsami.0c16380] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The CRISPR-Cas9 and related systems offer a unique genome-editing tool allowing facile and efficient introduction of heritable and locus-specific sequence modifications in the genome. Despite its molecular precision, temporal and spatial control of gene editing with the CRISPR-Cas9 system is very limited. We developed a light-sensitive liposome delivery system that offers a high degree of spatial and temporal control of gene editing with the CRISPR-Cas9 system. We demonstrated its efficient protein release by respectively assessing the targeted knockout of the eGFP gene in human HEK293/GFP cells and the TNFAIP3 gene in TNFα-induced HEK293 cells. We further validated our results at a single-cell resolution using an in vivo eGFP reporter system in zebrafish (77% knockout). These findings indicate that light-triggered liposomes may have new options for precise control of CRISPR-Cas9 release and editing.
Collapse
Affiliation(s)
- Yagiz Alp Aksoy
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Centre for Motor Neuron Disease Research, Macquarie University, Sydney, NSW 2109, Australia
- Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia
| | - Biyao Yang
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wenjie Chen
- Center for Pharmaceutical Engineering and Sciences, Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Tzongtyng Hung
- The Biological Resource Imaging Laboratory, University of New South Wales, Sydney, NSW 2052, Australia
| | - Rhiannon P Kuchel
- Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nathan W Zammit
- Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Shane T Grey
- Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ewa M Goldys
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wei Deng
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
5
|
Cultrone D, Zammit NW, Self E, Postert B, Han JZR, Bailey J, Warren J, Croucher DR, Kikuchi K, Bogdanovic O, Chtanova T, Hesselson D, Grey ST. A zebrafish functional genomics model to investigate the role of human A20 variants in vivo. Sci Rep 2020; 10:19085. [PMID: 33154446 PMCID: PMC7644770 DOI: 10.1038/s41598-020-75917-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 09/25/2020] [Indexed: 01/21/2023] Open
Abstract
Germline loss-of-function variation in TNFAIP3, encoding A20, has been implicated in a wide variety of autoinflammatory and autoimmune conditions, with acquired somatic missense mutations linked to cancer progression. Furthermore, human sequence data reveals that the A20 locus contains ~ 400 non-synonymous coding variants, which are largely uncharacterised. The growing number of A20 coding variants with unknown function, but potential clinical impact, poses a challenge to traditional mouse-based approaches. Here we report the development of a novel functional genomics approach that utilizes a new A20-deficient zebrafish (Danio rerio) model to investigate the impact of TNFAIP3 genetic variants in vivo. A20-deficient zebrafish are hyper-responsive to microbial immune activation and exhibit spontaneous early lethality. Ectopic addition of human A20 rescued A20-null zebrafish from lethality, while missense mutations at two conserved A20 residues, S381A and C243Y, reversed this protective effect. Ser381 represents a phosphorylation site important for enhancing A20 activity that is abrogated by its mutation to alanine, or by a causal C243Y mutation that triggers human autoimmune disease. These data reveal an evolutionarily conserved role for TNFAIP3 in limiting inflammation in the vertebrate linage and show how this function is controlled by phosphorylation. They also demonstrate how a zebrafish functional genomics pipeline can be utilized to investigate the in vivo significance of medically relevant human TNFAIP3 gene variants.
Collapse
Affiliation(s)
- Daniele Cultrone
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - Nathan W Zammit
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - Eleanor Self
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - Benno Postert
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,Diabetes Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Jeremy Z R Han
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,The Kinghorn Cancer Centre, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Jacqueline Bailey
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - Joanna Warren
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - David R Croucher
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,The Kinghorn Cancer Centre, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Kazu Kikuchi
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,Developmental and Stem Cell Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Ozren Bogdanovic
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,Epigenetics Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Tatyana Chtanova
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia
| | - Daniel Hesselson
- St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.,Diabetes Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia
| | - Shane T Grey
- Immunology Division, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW, 2010, Australia. .,St Vincent's Clinical School, The University of New South Wales Sydney, Darlinghurst, NSW, 2010, Australia.
| |
Collapse
|
6
|
Zammit NW, Walters SN, Seeberger KL, O'Connell PJ, Korbutt GS, Grey ST. A20 as an immune tolerance factor can determine islet transplant outcomes. JCI Insight 2019; 4:131028. [PMID: 31581152 DOI: 10.1172/jci.insight.131028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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: 06/12/2019] [Accepted: 09/25/2019] [Indexed: 01/05/2023] Open
Abstract
Islet transplantation can restore lost glycemic control in type 1 diabetes subjects but is restricted in its clinical application by a limiting supply of islets and the need for heavy immune suppression to prevent rejection. TNFAIP3, encoding the ubiquitin editing enzyme A20, regulates the activation of immune cells by raising NF-κB signaling thresholds. Here, we show that increasing A20 expression in allogeneic islet grafts resulted in permanent survival for ~45% of recipients, and > 80% survival when combined with subtherapeutic rapamycin. Allograft survival was dependent upon Tregs and was antigen specific, and grafts showed reduced expression of inflammatory factors. Transplantation of islets with A20 containing a loss-of-function variant (I325N) resulted in increased RIPK1 ubiquitination and NF-κB signaling, graft hyperinflammation, and acute allograft rejection. Overexpression of A20 in human islets potently reduced expression of inflammatory mediators, with no impact on glucose-stimulated insulin secretion. Therapeutic administration of A20 raises inflammatory signaling thresholds to favor immune tolerance and promotes islet allogeneic survival. Clinically, this would allow for reduced immunosuppression and support the use of alternate islet sources.
Collapse
Affiliation(s)
- Nathan W Zammit
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Stacey N Walters
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Karen L Seeberger
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Philip J O'Connell
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney at Westmead Hospital, NSW Australia
| | - Gregory S Korbutt
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Shane T Grey
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| |
Collapse
|
7
|
Villanueva JE, Walters SN, Saito M, Malle EK, Zammit NW, Watson KA, Brink R, La Gruta NL, Alexander SI, Grey ST. Targeted deletion of Traf2 allows immunosuppression-free islet allograft survival in mice. Diabetologia 2017; 60:679-689. [PMID: 28062921 DOI: 10.1007/s00125-016-4198-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [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: 07/27/2016] [Accepted: 12/05/2016] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS Administration of anti-CD40 ligand (CD40L) antibodies has been reported to allow long-term islet allograft survival in non-human primates without the need for exogenous immunosuppression. However, the use of anti-CD40L antibodies was associated with thromboembolic complications. Targeting downstream intracellular components shared between CD40 and other TNF family co-stimulatory molecules could bypass these complications. TNF receptor associated factor 2 (TRAF2) integrates multiple TNF receptor family signalling pathways that are critical for T cell activation and may be a central node of alloimmune responses. METHODS T cell-specific Traf2-deficient mice (Traf2TKO) were generated to define the role of TRAF2 in CD4+ T cell effector responses that mediate islet allograft rejection in vivo. In vitro allograft responses were tested using mixed lymphocyte reactions and analysis of IFN-γ and granzyme B effector molecule expression. T cell function was assessed using anti-CD3/CD28-mediated proliferation and T cell polarisation studies. RESULTS Traf2TKO mice exhibited permanent survival of full MHC-mismatched pancreatic islet allografts without exogenous immunosuppression. Traf2TKO CD4+ T cells exhibited reduced proliferation, activation and acquisition of effector function following T cell receptor stimulation; however, both Traf2TKO CD4+ and CD8+ T cells exhibited impaired alloantigen-mediated proliferation and acquisition of effector function. In polarisation studies, Traf2TKO CD4+ T cells preferentially converted to a T helper (Th)2 phenotype, but exhibited impaired Th17 differentiation. Without TRAF2, thymocytes exhibited dysregulated TNF-mediated induction of c-Jun N-terminal kinase (JNK) and canonical NFκB pathways. Critically, targeting TRAF2 in T cells did not impair the acute phase of CD8-dependent viral immunity. These data highlight a specific requirement for a TRAF2-NFκB and TRAF2-JNK signalling cascade in T cell activation and effector function in rejecting islet allografts. CONCLUSION/INTERPRETATION Targeting TRAF2 may be useful as a therapeutic approach for immunosuppression-free islet allograft survival that avoids the thromboembolic complications associated with the use of anti-CD40L antibodies.
Collapse
Affiliation(s)
- Jeanette E Villanueva
- Transplantation Immunology Group, Immunology Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Stacey N Walters
- Transplantation Immunology Group, Immunology Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - Mitsuru Saito
- Centre for Kidney Research, Children's Hospital at Westmead, University of Sydney, Westmead, NSW, Australia
| | - Elisabeth K Malle
- Transplantation Immunology Group, Immunology Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - Nathan W Zammit
- Transplantation Immunology Group, Immunology Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - Katherine A Watson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, VIC, Australia
- Immunology Division, The Walter and Eliza Hall Institute for Medical Research, Melbourne, VIC, Australia
| | - Robert Brink
- B Cell Biology Group, Immunology Division, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Nicole L La Gruta
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, VIC, Australia
- Department of Biochemistry and Molecular Biology, Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Stephen I Alexander
- Centre for Kidney Research, Children's Hospital at Westmead, University of Sydney, Westmead, NSW, Australia
| | - Shane T Grey
- Transplantation Immunology Group, Immunology Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| |
Collapse
|
8
|
Malle EK, Zammit NW, Walters SN, Koay YC, Wu J, Tan BM, Villanueva JE, Brink R, Loudovaris T, Cantley J, McAlpine SR, Hesselson D, Grey ST. Nuclear factor κB-inducing kinase activation as a mechanism of pancreatic β cell failure in obesity. J Exp Med 2015; 212:1239-54. [PMID: 26122662 PMCID: PMC4516791 DOI: 10.1084/jem.20150218] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/22/2015] [Indexed: 12/29/2022] Open
Abstract
The nuclear factor κB (NF-κB) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic β cell dysfunction in the metabolic syndrome. Whereas canonical NF-κB signaling is well studied, there is little information on the divergent noncanonical NF-κB pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-κB-inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of β cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-κB components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive β cell-intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to β cell failure. These studies reveal that NIK contributes a central mechanism for β cell failure in diet-induced obesity.
Collapse
Affiliation(s)
- Elisabeth K Malle
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Nathan W Zammit
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Stacey N Walters
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Yen Chin Koay
- School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia
| | - Jianmin Wu
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia St Vincent's Clinical School, University of New South Wales, Sydney NSW 2010, Australia
| | - Bernice M Tan
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Jeanette E Villanueva
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Robert Brink
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia St Vincent's Clinical School, University of New South Wales, Sydney NSW 2010, Australia
| | - Tom Loudovaris
- St. Vincent's Institute of Medical Research, Fitzroy VIC 3065, Australia
| | - James Cantley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, England, UK
| | - Shelli R McAlpine
- School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia
| | - Daniel Hesselson
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| | - Shane T Grey
- Transplantation Immunology Group, Immunology Division, Cancer Bioinformatics, Cancer Division, B Cell Biology, Immunology Division, and Beta Cell Regeneration, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst NSW 2010, Australia
| |
Collapse
|
9
|
Villanueva JE, Malle EK, Gardam S, Silveira PA, Zammit NW, Walters SN, Brink R, Grey ST. TRAF2 regulates peripheral CD8(+) T-cell and NKT-cell homeostasis by modulating sensitivity to IL-15. Eur J Immunol 2015; 45:1820-31. [PMID: 25931426 DOI: 10.1002/eji.201445416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 12/16/2014] [Revised: 02/18/2015] [Accepted: 04/28/2015] [Indexed: 11/07/2022]
Abstract
In this study, a critical and novel role for TNF receptor (TNFR) associated factor 2 (TRAF2) is elucidated for peripheral CD8(+) T-cell and NKT-cell homeostasis. Mice deficient in TRAF2 only in their T cells (TRAF2TKO) show ∼40% reduction in effector memory and ∼50% reduction in naïve CD8(+) T-cell subsets. IL-15-dependent populations were reduced further, as TRAF2TKO mice displayed a marked ∼70% reduction in central memory CD8(+) CD44(hi) CD122(+) T cells and ∼80% decrease in NKT cells. TRAF2TKO CD8(+) CD44(hi) T cells exhibited impaired dose-dependent proliferation to exogenous IL-15. In contrast, TRAF2TKO CD8(+) T cells proliferated normally to anti-CD3 and TRAF2TKO CD8(+) CD44(hi) T cells exhibited normal proliferation to exogenous IL-2. TRAF2TKO CD8(+) T cells expressed normal levels of IL-15-associated receptors and possessed functional IL-15-mediated STAT5 phosphorylation, however TRAF2 deletion caused increased AKT activation. Loss of CD8(+) CD44(hi) CD122(+) and NKT cells was mechanistically linked to an inability to respond to IL-15. The reduced CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell populations in TRAF2TKO mice were rescued in the presence of high dose IL-15 by IL-15/IL-15Rα complex administration. These studies demonstrate a critical role for TRAF2 in the maintenance of peripheral CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell homeostasis by modulating sensitivity to T-cell intrinsic growth factors such as IL-15.
Collapse
Affiliation(s)
| | | | - Sandra Gardam
- B cell Biology Group, Immunology Division, Garvan Institute of Medical Research, Darlinghurst, Australia
| | | | | | | | - Robert Brink
- B cell Biology Group, Immunology Division, Garvan Institute of Medical Research, Darlinghurst, Australia
| | | |
Collapse
|
10
|
Abstract
A20 is most characteristically described in terms relating to inflammation and inflammatory pathologies. The emerging understanding of inflammation in the etiology of diabetes mellitus lays the framework for considering a central role for A20 in this disease process. Diabetes mellitus is considered a major health issue, and describes a group of common metabolic disorders pathophysiologically characterized by hyperglycemia. Within islets of Langherhans, the endocrine powerhouse of the pancreas, are the insulin-producing pancreatic beta-cells. Loss of beta-cell mass and function to inflammation and apoptosis is a major contributing factor to diabetes. Consequently, restoring functional beta-cell mass via transplantation represents a therapeutic option for diabetes. Unfortunately, transplanted islets also suffers from loss of beta-cell function and mass fueled by a multifactorial inflammatory cycle triggered by islet isolation prior to transplantation, the ischemic environment at transplantation as well as allogeneic or recurrent auto-immune responses. Activation of the transcription factor NF-kappaB is a central mediator of inflammatory mediated beta-cell dysfunction and loss. Accordingly, a plethora of strategies to block NF-kappaB activation in islets and hence limit beta-cell loss have been explored, with mixed success. We propose that the relatively poor efficacy of NF-kappaB blockade in beta-cells is due to concommittant loss of the important, NF-kappaB regulated anti-apoptotic and anti-inflammatory protein A20. A20 has been identified as a beta-cell expressed gene, raising questions about its role in beta-cell development and function, and in beta-cell related pathologies. Involvement of apoptosis, inflammation and NF-kappaB activation as beta-cell factors contributing to the pathophysiology of diabetes, coupled with the knowledge that beta-cells express the A20 gene, implies an important role for A20 in both normal beta-cell biology as well as beta-cell related pathology. Genome wide association studies (GWAS) linking single nucleotide polymorphisms in the A20 gene with the occurrence of diabetes and its complications support this hypothesis. In this chapter we review data supporting the role of A20 in beta-cell health and disease. Furthermore, by way of their specialized function in metabolism, pancreatic beta-cells also provide opportunities to explore the biology of A20 in scenarios beyond inflammation.
Collapse
|
11
|
Tan BM, Zammit NW, Yam AO, Slattery R, Walters SN, Malle E, Grey ST. Baculoviral inhibitors of apoptosis repeat containing (BIRC) proteins fine-tune TNF-induced nuclear factor κB and c-Jun N-terminal kinase signalling in mouse pancreatic beta cells. Diabetologia 2013; 56:520-32. [PMID: 23250032 DOI: 10.1007/s00125-012-2784-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [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: 07/09/2012] [Accepted: 10/19/2012] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS For beta cells, contact with TNF-α triggers signalling cascades that converge on pathways important for cell survival and inflammation, specifically nuclear factor κB (NF-κB), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase pathways. Here, we investigated the function of baculoviral inhibitors of apoptosis repeat containing (BIRC) proteins in regulating TNF signalling cascades. METHODS TNF regulation of Birc genes was studied by mRNA expression and promoter analysis. Birc gene control of cell signalling was studied in beta cell lines, and in islets from Birc2(-/-) and Birc3(-/-) mice, and from Birc3(-/-) Birc2Δ beta cell mice that selectively lack Birc2 and Birc3 (double knockout [DKO]). Islet function was tested by intraperitoneal glucose tolerance test and transplantation. RESULTS TNF-α selectively induced Birc3 in beta cells, which in turn was sufficient to drive and potentiate NF-κB reporter activity. Conversely, Birc3(-/-) islets exhibited delayed TNF-α-induced IκBα degradation with reduced expression of Ccl2 and Cxcl10. DKO islets showed a further delay in IκBα degradation kinetics. Surprisingly, DKO islets exhibited stimulus-independent and TNF-dependent hyperexpression of TNF target genes A20 (also known as Tnfaip3), Icam1, Ccl2 and Cxcl10. DKO islets showed hyperphosphorylation of the JNK-substrate, c-Jun, while a JNK-antagonist prevented increases of Icam1, Ccl2 and Cxcl10 expression. Proteosome blockade of MIN6 cells phenocopied DKO islets. DKO islets showed more rapid loss of glucose homeostasis when challenged with the inflammatory insult of transplantation. CONCLUSIONS/INTERPRETATION BIRC3 provides a feed-forward loop, which, with BIRC2, is required to moderate the normal speed of NF-κB activation. Paradoxically, BIRC2 and BIRC3 act as a molecular brake to rein in activation of the JNK signalling pathway. Thus BIRC2 and BIRC3 fine-tune NF-κB and JNK signalling to ensure transcriptional responses are appropriately matched to extracellular inputs. This control is critical for the beta cell's stress response.
Collapse
Affiliation(s)
- B M Tan
- Gene Therapy and Autoimmunity Group, Immunology Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia
| | | | | | | | | | | | | |
Collapse
|
12
|
Zammit NW, Tan BM, Walters SN, Liuwantara D, Villanueva JE, Malle EK, Grey ST. Low-dose rapamycin unmasks the protective potential of targeting intragraft NF-κB for islet transplants. Cell Transplant 2012; 22:2355-66. [PMID: 23127588 DOI: 10.3727/096368912x658737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Islet grafts can contribute to their own destruction via the elaboration of proinflammatory genes, many of which are transcriptionally regulated by nuclear factor κ-light-chain-enhancer of activated B-cells (NF-κB). Thus, NF-κB constitutes an enticing gene therapy candidate to improve the success of islet transplantation. To test this hypothesis in vivo, we blocked NF-κB in BALB/c (H2(d)) to C57/BL6 (H2(b)) mouse islet allografts by genetically engineering islets to express the NF-κB superrepressor, IκBα. Here we show by microarray and RTqPCR that islets exhibit an intrinsic early immediate proinflammatory response, with the most highly upregulated proinflammatory genes comprising the chemokines Cxcl1, Cxcl2, Cxcl10, and Ccl2; the cytokines Tnf-α and Il-6; and the adhesion molecule Icam1. Overexpression of IκBα inhibited the expression of these genes by 50-95% in islets and MIN6 β-cells in vitro, by inhibiting NF-κB-dependent gene transcription. Histological and RTqPCR analysis at postoperative day (POD) 10 revealed that IκBα-transduced islet allografts exhibited improved islet architecture and strong insulin-labeling with decreased Ccl2 and Il-6 mRNA levels compared to the GFP-transduced control grafts. Despite these protective effects, NF-κB-blocked islet allografts were promptly rejected in our MHC-mismatched mouse model. However, IκBα-expressing grafts did harbor localized "pockets" of Foxp3(+) mononuclear cells not evident in the control grafts. This result suggested that the effect of the NF-κB blockade might synergize with regulatory T-cell-sparing rapamycin. Indeed, combining intragraft IκBα expression with low-dose rapamycin increased the mean survival time of islet allografts from 20 to 81 days, with 20% of the grafts surviving for greater than 100 days. In conclusion, rapamycin unmasks the protective potential of intragraft NF-κB blockade, which can, in some cases, permit permanent allograft survival without continuous systemic immunosuppression.
Collapse
Affiliation(s)
- Nathan W Zammit
- Gene Therapy and Autoimmunity Group, Immunology Program, Garvan Institute, Darlinghurst, NSW, Australia
| | | | | | | | | | | | | |
Collapse
|
13
|
Cowley MJ, Weinberg A, Zammit NW, Walters SN, Hawthorne WJ, Loudovaris T, Thomas H, Kay T, Gunton JE, Alexander SI, Kaplan W, Chapman J, O'Connell PJ, Grey ST. Human islets express a marked proinflammatory molecular signature prior to transplantation. Cell Transplant 2012; 21:2063-78. [PMID: 22404979 DOI: 10.3727/096368911x627372] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In the context of islet transplantation, experimental models show that induction of islet intrinsic NF-κB-dependent proinflammatory genes can contribute to islet graft rejection. Isolation of human islets triggers activation of the NF-κB and mitogen-activated kinase (MAPK) stress response pathways. However, the downstream NF-κB target genes induced in human islets during the isolation process are poorly described. Therefore, in this study, using microarray, bioinformatic, and RTqPCR approaches, we determined the pattern of genes expressed by a set of 14 human islet preparations. We found that isolated human islets express a panel of genes reminiscent of cells undergoing a marked NF-κB-dependent proinflammatory response. Expressed genes included matrix metallopeptidase 1 (MMP1) and fibronectin 1 (FN1), factors involved in tissue remodeling, adhesion, and cell migration; inflammatory cytokines IL-1β and IL-8; genes regulating cell survival including A20 and ATF3; and notably high expression of a set of chemokines that would favor neutrophil and monocyte recruitment including CXCL2, CCL2, CXCL12, CXCL1, CXCL6, and CCL28. Of note, the inflammatory profile of isolated human islets was maintained after transplantation into RAG(-/-) recipients. Thus, human islets can provide a reservoir of NF-κB-dependent inflammatory factors that have the potential to contribute to the anti-islet-graft immune response. To test this hypothesis, we extracted rodent islets under optimal conditions, forced activation of NF-κB, and transplanted them into allogenic recipients. These NF-κB activated islets not only expressed the same chemokine profile observed in human islets but also struggled to maintain normoglycemia posttransplantation. Further, NF-κB-activated islets were rejected with a faster tempo as compared to non-NF-κB-activated rodent islets. Thus, isolated human islets can make cell autonomous contributions to the ensuing allograft response by elaborating inflammatory factors that contribute to their own demise. These data highlight the potential importance of islet intrinsic proinflammatory responses as targets for therapeutic intervention.
Collapse
Affiliation(s)
- Mark J Cowley
- Peter Wills Bioinformatics Centre, Darlinghurst, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|