1
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Blake D, Lynch KW. The three as: Alternative splicing, alternative polyadenylation and their impact on apoptosis in immune function. Immunol Rev 2021; 304:30-50. [PMID: 34368964 DOI: 10.1111/imr.13018] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/19/2021] [Accepted: 07/28/2021] [Indexed: 12/13/2022]
Abstract
The latest advances in next-generation sequencing studies and transcriptomic profiling over the past decade have highlighted a surprising frequency of genes regulated by RNA processing mechanisms in the immune system. In particular, two control steps in mRNA maturation, namely alternative splicing and alternative polyadenylation, are now recognized to occur in the vast majority of human genes. Both have the potential to alter the identity of the encoded protein, as well as control protein abundance or even protein localization or association with other factors. In this review, we will provide a summary of the general mechanisms by which alternative splicing (AS) and alternative polyadenylation (APA) occur, their regulation within cells of the immune system, and their impact on immunobiology. In particular, we will focus on how control of apoptosis by AS and APA is used to tune cell fate during an immune response.
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Affiliation(s)
- Davia Blake
- Immunology Graduate Group and the Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kristen W Lynch
- Immunology Graduate Group and the Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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2
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Limoges MA, Cloutier M, Nandi M, Ilangumaran S, Ramanathan S. The GIMAP Family Proteins: An Incomplete Puzzle. Front Immunol 2021; 12:679739. [PMID: 34135906 PMCID: PMC8201404 DOI: 10.3389/fimmu.2021.679739] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/12/2021] [Indexed: 12/19/2022] Open
Abstract
Overview: Long-term survival of T lymphocytes in quiescent state is essential to maintain their cell numbers in secondary lymphoid organs and in peripheral circulation. In the BioBreeding diabetes-prone strain of rats (BB-DP), loss of functional GIMAP5 (GTPase of the immune associated nucleotide binding protein 5) results in profound peripheral T lymphopenia. This discovery heralded the identification of a new family of proteins initially called Immune-associated nucleotide binding protein (IAN) family. In this review we will use ‘GIMAP’ to refer to this family of proteins. Recent studies suggest that GIMAP proteins may interact with each other and also be involved in the movement of the cellular cargo along the cytoskeletal network. Here we will summarize the current knowledge on the characteristics and functions of GIMAP family of proteins.
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Affiliation(s)
- Marc-André Limoges
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke and CRCHUS, Sherbrooke, QC, Canada
| | - Maryse Cloutier
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke and CRCHUS, Sherbrooke, QC, Canada
| | - Madhuparna Nandi
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke and CRCHUS, Sherbrooke, QC, Canada
| | - Subburaj Ilangumaran
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke and CRCHUS, Sherbrooke, QC, Canada
| | - Sheela Ramanathan
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke and CRCHUS, Sherbrooke, QC, Canada
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3
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Liao HY, Liao B, Zhang HH. CISD2 plays a role in age-related diseases and cancer. Biomed Pharmacother 2021; 138:111472. [PMID: 33752060 DOI: 10.1016/j.biopha.2021.111472] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/12/2022] Open
Abstract
CDGSH iron-sulfur domain 2 (Cisd2) is an evolutionarily conserved protein that plays an important regulatory role in aging-related diseases and cancers. Since its discovery, Cisd2 has been identified as a regulatory factor for the aging of the human body and the regulation of mammalian lifespan. Cisd2 is also an oncoprotein that regulates the occurrence and development of cancer. Cisd2 mediates the occurrence of diseases related to human aging and the proliferation, differentiation, metastasis, and invasion of various cancer cells through various mechanisms. Multiple studies have shown that Cisd2 expression is related to the clinical characteristics of aging-related diseases and patients with cancer, and its expression profile is a novel diagnostic and prognostic biomarker for a variety of human diseases. Modulating the expression or function of Cisd2 may be a potential treatment strategy for different diseases. In this review, we summarize the role of Cisd2 in human aging-related diseases and various cancers, as well as the biological functions, underlying mechanisms, and potential clinical significance.
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Affiliation(s)
- Hai-Yang Liao
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China; Orthopedics Key Laboratory of Gansu Province, Lanzhou 730000, PR China.
| | - Bei Liao
- Orthopedics Key Laboratory of Gansu Province, Lanzhou 730000, PR China; The First Clinical Medical College of Lanzhou University, 1 Donggang Road, Lanzhou 730000, PR China.
| | - Hai-Hong Zhang
- The Second Clinical Medical College of Lanzhou University, 82 Cuiying Men, Lanzhou 730030, PR China; Orthopedics Key Laboratory of Gansu Province, Lanzhou 730000, PR China.
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4
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Pascall JC, Webb LMC, Eskelinen EL, Innocentin S, Attaf-Bouabdallah N, Butcher GW. GIMAP6 is required for T cell maintenance and efficient autophagy in mice. PLoS One 2018; 13:e0196504. [PMID: 29718959 PMCID: PMC5931655 DOI: 10.1371/journal.pone.0196504] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 04/13/2018] [Indexed: 11/19/2022] Open
Abstract
The GTPases of the immunity-associated proteins (GIMAP) GTPases are a family of proteins expressed strongly in the adaptive immune system. We have previously reported that in human cells one member of this family, GIMAP6, interacts with the ATG8 family member GABARAPL2, and is recruited to autophagosomes upon starvation, suggesting a role for GIMAP6 in the autophagic process. To study this possibility and the function of GIMAP6 in the immune system, we have established a mouse line in which the Gimap6 gene can be inactivated by Cre-mediated recombination. In mice bred to carry the CD2Cre transgene such that the Gimap6 gene was deleted within the T and B cell lineages there was a 50–70% reduction in peripheral CD4+ and CD8+ T cells. Analysis of splenocyte-derived proteins from these mice indicated increased levels of MAP1LC3B, particularly the lipidated LC3-II form, and S405-phosphorylation of SQSTM1. Electron microscopic measurements of Gimap6-/- CD4+ T cells indicated an increased mitochondrial/cytoplasmic volume ratio and increased numbers of autophagosomes. These results are consistent with autophagic disruption in the cells. However, Gimap6-/- T cells were largely normal in character, could be effectively activated in vitro and supported T cell-dependent antibody production. Treatment in vitro of CD4+ splenocytes from GIMAP6fl/flERT2Cre mice with 4-hydroxytamoxifen resulted in the disappearance of GIMAP6 within five days. In parallel, increased phosphorylation of SQSTM1 and TBK1 was observed. These results indicate a requirement for GIMAP6 in the maintenance of a normal peripheral adaptive immune system and a significant role for the protein in normal autophagic processes. Moreover, as GIMAP6 is expressed in a cell-selective manner, this indicates the potential existence of a cell-restricted mode of autophagic regulation.
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Affiliation(s)
- John C. Pascall
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Louise M. C. Webb
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Eeva-Liisa Eskelinen
- Department of Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Silvia Innocentin
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Noudjoud Attaf-Bouabdallah
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | - Geoffrey W. Butcher
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
- * E-mail:
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5
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Serrano D, Ghobadi F, Boulay G, Ilangumaran S, Lavoie C, Ramanathan S. GTPase of the Immune-Associated Nucleotide Protein 5 Regulates the Lysosomal Calcium Compartment in T Lymphocytes. Front Immunol 2017; 8:94. [PMID: 28223986 PMCID: PMC5293772 DOI: 10.3389/fimmu.2017.00094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 01/19/2017] [Indexed: 12/20/2022] Open
Abstract
T lymphocytes from Gimap5lyp/lyp rats carrying a recessive mutation in the GTPase of immune-associated protein 5 (Gimap5) gene undergo spontaneous apoptosis. Molecular mechanisms underlying this survival defect are not yet clear. We have shown that Gimap5lyp/lyp T lymphocytes display reduced calcium influx following T cell antigen receptor (TCR) stimulation that was associated with impaired buffering of calcium by mitochondria. Here, we investigated the subcellular localization of GIMAP5 and its influence on Ca2+ response in HEK293T cells and T lymphocytes. The more abundantly expressed GIMAP5v2 localizes to the lysosome and certain endosomal vesicles. Gimap5lyp/lyp T lymphocytes showed increased accumulation of calcium in the lysosomes as evidenced by Gly-Phe β-naphthylamide (GPN) triggered Ca2+ release. As a corollary, GPN-induced Ca2+ flux was decreased in HEK293T cells expressing GIMAP5v2. Strikingly, TCR stimulation of rat, mouse, and human T lymphocytes increased lysosomal calcium content. Overall, our findings show that lysosomes modulate cellular Ca2+ response during T cell activation and that GIMAP5 regulates the lysosomal Ca2+ compartment in T lymphocytes.
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Affiliation(s)
- Daniel Serrano
- Immunology Division, Department of Pediatrics, Université de Sherbrooke , Sherbrooke, QC , Canada
| | - Farnaz Ghobadi
- Immunology Division, Department of Pediatrics, Université de Sherbrooke , Sherbrooke, QC , Canada
| | - Guylain Boulay
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Subburaj Ilangumaran
- Immunology Division, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christine Lavoie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sheela Ramanathan
- Immunology Division, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, QC, Canada
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6
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Chen XL, Serrano D, Ghobadi F, Mayhue M, Hoebe K, Ilangumaran S, Ramanathan S. TCR and IL-7 Signaling Are Altered in the Absence of Functional GTPase of the Immune Associated Nucleotide Binding Protein 5 (GIMAP5). PLoS One 2016; 11:e0151837. [PMID: 27023180 PMCID: PMC4811415 DOI: 10.1371/journal.pone.0151837] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/05/2016] [Indexed: 01/09/2023] Open
Abstract
GTPase of the immune associated nucleotide binding protein (GIMAP) family of proteins are expressed essentially in cells of the hematopoietic system. Mutation in the founding member of this gene family, Gimap5, results in the lymphopenic phenotype in Bio-Breeding diabetes prone rats. In mice, deletion of functional Gimap5 gene affects the survival and renewal of hematopoietic stem cells in addition to the defects observed in T cells. Here we show that T cells from OTII TCR-transgenic Gimap5sph/sph mice do not proliferate in response to its cognate antigen. Furthermore, T cells from Gimap5 mutant rats and mice show decreased phosphorylation of STAT5 following stimulation with IL-7. Our results suggest that functional Gimap5 is required for optimal signaling through TCR and IL-7R in T cells.
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Affiliation(s)
- Xi-Lin Chen
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Daniel Serrano
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Farnaz Ghobadi
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Marian Mayhue
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Kasper Hoebe
- Department of Pediatrics, Division of Cellular and Molecular Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States of America
| | - Subburaj Ilangumaran
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Sheela Ramanathan
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de recherche clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- * E-mail:
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7
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Webb LMC, Datta P, Bell SE, Kitamura D, Turner M, Butcher GW. GIMAP1 Is Essential for the Survival of Naive and Activated B Cells In Vivo. THE JOURNAL OF IMMUNOLOGY 2015; 196:207-16. [PMID: 26621859 DOI: 10.4049/jimmunol.1501582] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/30/2015] [Indexed: 12/30/2022]
Abstract
An effective immune system depends upon regulation of lymphocyte function and homeostasis. In recent years, members of the GTPases of the immunity associated protein (GIMAP) family were proposed to regulate T cell homeostasis. In contrast, little is known about their function and mode of action in B cells. We used a combination of transgenic mice and in vivo and in vitro techniques to conditionally and electively ablate GIMAP1 in resting and activated peripheral B cells. Our data suggest that GIMAP1 is absolutely essential for the survival of peripheral B cells, irrespective of their activation state. Together with recent data showing increased expression of GIMAP1 in B cell lymphomas, our work points to the possible potential of GIMAP1 as a target for manipulation in a variety of B cell-mediated diseases.
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Affiliation(s)
- Louise M C Webb
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom; and
| | - Preeta Datta
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom; and
| | - Sarah E Bell
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom; and
| | - Daisuke Kitamura
- Research Institute for Biomedical Sciences, Tokyo University of Science, Yamazaki 2669, Noda, Chiba 278-0022, Japan
| | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom; and
| | - Geoffrey W Butcher
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom; and
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8
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Chen XL, Serrano D, Mayhue M, Hoebe K, Ilangumaran S, Ramanathan S. GIMAP5 Deficiency Is Associated with Increased AKT Activity in T Lymphocytes. PLoS One 2015; 10:e0139019. [PMID: 26440416 PMCID: PMC4595448 DOI: 10.1371/journal.pone.0139019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/07/2015] [Indexed: 01/05/2023] Open
Abstract
Long-term survival of T lymphocytes in quiescent state is essential to maintain their cell numbers in secondary lymphoid organs. In mice and in rats, the loss of functional GTPase of the immune associated nucleotide binding protein 5 (GIMAP5) causes peripheral T lymphopenia due to spontaneous death of T cells. The underlying mechanism responsible for the disruption of quiescence in Gimap5 deficient T cells remains largely unknown. In this study, we show that loss of functional Gimap5 results in increased basal activation of mammalian target of rapamycin (mTOR), independent of protein phosphatase 2A (PP2A) or AMP-activated protein kinase (AMPK). Our results suggest that the constitutive activation of the phosphoinositide 3-kinase (PI3K) pathway may be one of the consequences of the absence of functional GIMAP5.
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Affiliation(s)
- Xi-Lin Chen
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Daniel Serrano
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Marian Mayhue
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Kasper Hoebe
- Department of Pediatrics, Division of Cellular and Molecular Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States of America
| | - Subburaj Ilangumaran
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de Recherche Clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Sheela Ramanathan
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de Recherche Clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- * E-mail:
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9
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Sarmiento J, Wallis RH, Ning T, Marandi L, Chao G, Veillette A, Lernmark Å, Paterson AD, Poussier P. A functional polymorphism of Ptpn22 is associated with type 1 diabetes in the BioBreeding rat. THE JOURNAL OF IMMUNOLOGY 2014; 194:615-29. [PMID: 25505293 DOI: 10.4049/jimmunol.1302689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The R620W variant of PTPN22 is one of the major genetic risk factors for several autoimmune disorders including type 1 diabetes (T1D) in humans. In the BioBreeding T1D-prone (BBDP) rat, a single nucleotide polymorphism in Ptpn22 results in an A629T substitution immediately C-terminal to the aliphatic residues central to the Ptpn22-C-terminal Src kinase interaction. This variant exhibits a 50% decrease in C-terminal Src kinase binding affinity and contributes to T cell hyperresponsiveness. Examination of BBDP sublines congenic for the Iddm26.2 locus that includes Ptpn22 has not only shown an expansion of activated CD4(+)25(+) T lymphocytes in animals homozygous for the BBDP allele, consistent with enhanced TCR-mediated signaling, but also a decrease in their proportion of peripheral Foxp3(+) regulatory T cells. Furthermore, clinical assessment of both an F2(BBDP × ACI.1u.Lyp) cohort and Iddm26.2 congenic BBDP sublines has revealed an association of Ptpn22 with T1D. Specifically, in both cases, T1D risk is significantly greater in BBDP Ptpn22 homozygous and heterozygous animals. These findings are consistent with a role for rat Ptpn22 allelic variation within Iddm26.2 in the regulation of T cell responses, and subsequently the risk for development of T1D.
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Affiliation(s)
- Janice Sarmiento
- Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | - Robert H Wallis
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | - Terri Ning
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | - Leili Marandi
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | - Gary Chao
- Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | - André Veillette
- Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Åke Lernmark
- Department of Clinical Sciences, Lund University, 20502 Malmö, Sweden
| | - Andrew D Paterson
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M5T 3M7, Canada; and Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Philippe Poussier
- Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada;
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10
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Tubulin- and actin-associating GIMAP4 is required for IFN-γ secretion during Th cell differentiation. Immunol Cell Biol 2014; 93:158-66. [PMID: 25287446 PMCID: PMC4355353 DOI: 10.1038/icb.2014.86] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 09/05/2014] [Accepted: 09/06/2014] [Indexed: 12/20/2022]
Abstract
Although GTPase of the immunity-associated protein (GIMAP) family are known to be most highly expressed in the cells of the immune system, their function and role remain still poorly characterized. Small GTPases in general are known to be involved in many cellular processes in a cell type-specific manner and to contribute to specific differentiation processes. Among GIMAP family, GIMAP4 is the only member reported to have true GTPase activity, and its transcription is found to be differentially regulated during early human CD4(+) T helper (Th) lymphocyte differentiation. GIMAP4 has been previously connected mainly with T- and B-cell development and survival and T-cell apoptosis. Here we show GIMAP4 to be localized into cytoskeletal elements and with the component of the trans golgi network, which suggests it to have a function in cellular transport processes. We demonstrate that depletion of GIMAP4 with RNAi results in downregulation of endoplasmic reticulum localizing chaperone VMA21. Most importantly, we discovered that GIMAP4 regulates secretion of cytokines in early differentiating human CD4(+) Th lymphocytes and in particular the secretion of interferon-γ also affecting its downstream targets.
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11
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Wang CH, Chen YF, Wu CY, Wu PC, Huang YL, Kao CH, Lin CH, Kao LS, Tsai TF, Wei YH. Cisd2 modulates the differentiation and functioning of adipocytes by regulating intracellular Ca2+ homeostasis. Hum Mol Genet 2014; 23:4770-85. [PMID: 24833725 DOI: 10.1093/hmg/ddu193] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
CISD2 is a causative gene associated with Wolfram syndrome (WFS). However, it remains a mystery as to how the loss of CISD2 causes metabolic defects in patients with WFS. Investigation on the role played by Cisd2 in specific cell types may help us to resolve these underlying mechanisms. White adipose tissue (WAT) is central to the maintenance of energy metabolism and glucose homeostasis in humans. In this study, adipocyte-specific Cisd2 knockout (KO) mice showed impairment in the development of epididymal WAT (eWAT) in the cell autonomous manner. A lack of Cisd2 caused defects in the biogenesis and function of mitochondria during differentiation of adipocytes in vitro. Insulin-stimulated glucose uptake and secretion of adiponectin by the Cisd2 KO adipocytes were decreased. Moreover, Cisd2 deficiency increased the cytosolic level of Ca(2+) and induced Ca(2+)-calcineurin-dependent signaling that inhibited adipogenesis. Importantly, Cisd2 was found to interact with Gimap5 on the mitochondrial and ER membranes and thereby modulate mitochondrial Ca(2+) uptake associated with the maintenance of intracellular Ca(2+) homeostasis in adipocytes. Thus, it would seem that Cisd2 plays an important role in intracellular Ca(2+) homeostasis, which is required for the differentiation and functioning of adipocytes as well as the regulation of glucose homeostasis in mice.
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Affiliation(s)
| | - Yi-Fan Chen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli County 350, Taiwan Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan
| | - Chia-Yu Wu
- Department of Life Sciences and Institute of Genome Sciences
| | - Pei-Chun Wu
- Department of Life Sciences and Institute of Genome Sciences Brain Research Center
| | - Yi-Long Huang
- Department of Life Sciences and Institute of Genome Sciences
| | - Cheng-Heng Kao
- Center of General Education, Chang Gung University, Taoyuan 333, Taiwan
| | - Chao-Hsiung Lin
- Department of Life Sciences and Institute of Genome Sciences
| | - Lung-Sen Kao
- Department of Life Sciences and Institute of Genome Sciences Brain Research Center
| | - Ting-Fen Tsai
- Department of Life Sciences and Institute of Genome Sciences Brain Research Center Aging and Health Research Center, National Yang-Ming University, Taipei 112, Taiwan Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli County 350, Taiwan
| | - Yau-Huei Wei
- Institute of Biochemistry and Molecular Biology Department of Medicine, Mackay Medical College, Sanzhi, New Taipei City 252, Taiwan
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12
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Sionov RV. MicroRNAs and Glucocorticoid-Induced Apoptosis in Lymphoid Malignancies. ISRN HEMATOLOGY 2013; 2013:348212. [PMID: 23431463 PMCID: PMC3569899 DOI: 10.1155/2013/348212] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 11/14/2012] [Indexed: 12/20/2022]
Abstract
The initial response of lymphoid malignancies to glucocorticoids (GCs) is a critical parameter predicting successful treatment. Although being known as a strong inducer of apoptosis in lymphoid cells for almost a century, the signaling pathways regulating the susceptibility of the cells to GCs are only partly revealed. There is still a need to develop clinical tests that can predict the outcome of GC therapy. In this paper, I discuss important parameters modulating the pro-apoptotic effects of GCs, with a specific emphasis on the microRNA world comprised of small players with big impacts. The journey through the multifaceted complexity of GC-induced apoptosis brings forth explanations for the differential treatment response and raises potential strategies for overcoming drug resistance.
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Affiliation(s)
- Ronit Vogt Sionov
- The Department of Biochemistry and Molecular Biology, The Institute for Medical Research-Israel-Canada, Hadassah Medical School, The Hebrew University of Jerusalem, Ein-Kerem, 91120 Jerusalem, Israel
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13
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Bortell R, Yang C. The BB rat as a model of human type 1 diabetes. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2013; 933:31-44. [PMID: 22893399 DOI: 10.1007/978-1-62703-068-7_3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The BB rat is an important rodent model of human type 1 diabetes (T1D) and has been used to study mechanisms of diabetes pathogenesis as well as to investigate potential intervention therapies for clinical trials. The Diabetes-Prone BB (BBDP) rat spontaneously develops autoimmune T1D between 50 and 90 days of age. The Diabetes-Resistant BB (BBDR) rat has similar diabetes-susceptible genes as the BBDP, but does not become diabetic in viral antibody-free conditions. However, the BBDR rat can be induced to develop T1D in response to certain treatments such as regulatory T cell (T(reg)) depletion, toll-like receptor ligation, or virus infection. These diabetes-inducible rats develop hyperglycemia under well-controlled circumstances and within a short, predictable time frame (14-21 days), thus facilitating their utility for investigations of specific stages of diabetes development. Therefore, these rat strains are invaluable models for studying autoimmune diabetes and the role of environmental factors in its development, of particular importance due to the influx of studies associating virus infection and human T1D.
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Affiliation(s)
- Rita Bortell
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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GTPase of the immune-associated nucleotide-binding protein 5 (GIMAP5) regulates calcium influx in T-lymphocytes by promoting mitochondrial calcium accumulation. Biochem J 2012; 449:353-64. [DOI: 10.1042/bj20120516] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mature T-lymphocytes undergo spontaneous apoptosis in the biobreeding diabetes-prone strain of rats due to the loss of the functional GIMAP5 (GTPase of the immune-associated nucleotide-binding protein 5) protein. The mechanisms underlying the pro-survival function of GIMAP5 in T-cells have not yet been elucidated. We have previously shown that GIMAP5 deficiency in T-cells impairs Ca2+ entry via plasma membrane channels following exposure to thapsigargin or stimulation of the T-cell antigen receptor. In the present study we report that this reduced Ca2+ influx in GIMAP5-deficient T-cells is associated with the inability of their mitochondria to sequester Ca2+ following capacitative entry, which is required for sustained Ca2+ influx via the plasma membrane channels. Consistent with a role for GIMAP5 in regulating mitochondrial Ca2+, overexpression of GIMAP5 in HEK (human embryonic kidney)-293 cells resulted in increased Ca2+ accumulation within the mitochondria. Disruption of microtubules, but not the actin cytoskeleton, abrogated mitochondrial Ca2+ sequestration in primary rat T-cells, whereas both microtubules and actin cytoskeleton were needed for the GIMAP5-mediated increase in mitochondrial Ca2+ in HEK-293 cells. Moreover, GIMAP5 showed partial colocalization with tubulin in HEK-293 cells. On the basis of these findings, we propose that the pro-survival function of GIMAP5 in T-lymphocytes may be linked to its requirement to facilitate microtubule-dependent mitochondrial buffering of Ca2+ following capacitative entry.
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Lee YJ, Horie Y, Wallace GR, Choi YS, Park JA, Choi JY, Song R, Kang YM, Kang SW, Baek HJ, Kitaichi N, Meguro A, Mizuki N, Namba K, Ishida S, Kim J, Niemczyk E, Lee EY, Song YW, Ohno S, Lee EB. Genome-wide association study identifies GIMAP as a novel susceptibility locus for Behcet's disease. Ann Rheum Dis 2012; 72:1510-6. [PMID: 23041938 DOI: 10.1136/annrheumdis-2011-200288] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVES To identify non-major histocompatibility complex susceptible genes that might contribute to Behçet's disease (BD). METHODS We performed a genome-wide association study using DNA samples from a Korean population consisting of 379 BD patients and 800 controls. A replication study was performed in a Japanese population (363 BD patients and 272 controls). To evaluate the functional implication of the target single nucleotide polymorphisms (SNP), gene expression levels in peripheral T cells, allele-specific modulation of promoter activity and biological effect of mRNA knockdown were investigated. RESULTS We found a novel association of BD to the GIMAP locus, mapped to chromosome 7q36.1 (rs1608157, p=6.01×10(-8) in a minor allele dominant model; rs11769828, allele based p=1.60×10(-6)). A fine mapping study identified an association with four additional SNP: rs1522596 (OR=1.45, p=7.70×10(-6)) in GIMAP4; rs10266069 (OR=1.32, p=2.67×10(-4)) and rs10256482 (OR=1.27, p=5.27×10(-4)) in GIMAP2; and rs2286900 (OR=1.61, p=3.53×10(-5)) in GIMAP1 areas. Replication study using DNA samples from the Japanese population validated the significant association between BD and the GIMAP locus. The GIMAP4 promoter construct plasmid with the minor allele of rs1608157 displayed significantly lower activity than one with the major allele. Moreover, CD4 T cells from BD patients showed a lower level of GIMAP4 mRNA, and GIMAP4 knockdown was protective against Fas-mediated apoptosis. CONCLUSIONS These results suggest that a GIMAP cluster is a novel susceptibility locus for BD, which is involved in T-cell survival, and T-cell aberration can contribute to the development of BD.
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Affiliation(s)
- Yun Jong Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnamsi, Korea
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Chen Y, Yu M, Dai X, Zogg M, Wen R, Weiler H, Wang D. Critical role for Gimap5 in the survival of mouse hematopoietic stem and progenitor cells. ACTA ACUST UNITED AC 2011; 208:923-35. [PMID: 21502331 PMCID: PMC3092340 DOI: 10.1084/jem.20101192] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
HSCs lacking the guanosine nucleotide-binding protein Gimap5, which stabilizes expression of the Mcl-1 Bcl2 family protein, exhibit impaired survival and long-term repopulation capacity. Mice and rats lacking the guanosine nucleotide-binding protein Gimap5 exhibit peripheral T cell lymphopenia, and Gimap5 can bind to Bcl-2. We show that Gimap5-deficient mice showed progressive multilineage failure of bone marrow and hematopoiesis. Compared with wild-type counterparts, Gimap5-deficient mice contained more hematopoietic stem cells (HSCs) but fewer lineage-committed hematopoietic progenitors. The reduction of progenitors and differentiated cells in Gimap5-deficient mice resulted in a loss of HSC quiescence. Gimap5-deficient HSCs and progenitors underwent more apoptosis and exhibited defective long-term repopulation capacity. Absence of Gimap5 disrupted interaction between Mcl-1—which is essential for HSC survival—and HSC70, enhanced Mcl-1 degradation, and compromised mitochondrial integrity in progenitor cells. Thus, Gimap5 is an important stabilizer of mouse hematopoietic progenitor cell survival.
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Affiliation(s)
- Yuhong Chen
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA
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Notch protection against apoptosis in T-ALL cells mediated by GIMAP5. Blood Cells Mol Dis 2010; 45:201-9. [PMID: 20817506 DOI: 10.1016/j.bcmd.2010.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/14/2010] [Accepted: 06/21/2010] [Indexed: 12/16/2022]
Abstract
Recent studies have highlighted the role of Notch signalling in the development of T cell acute lymphoblasic leukaemia (T-ALL). Over-expression of Notch3 and gain of function mutations in the Notch1 gene have been reported. The aims of this study were to determine the effect of Notch signalling on apoptosis in human T-ALL cell lines and to identify targets of Notch signalling that may mediate this effect. Functional studies showed that inhibition of Notch signalling using gamma secretase inhibitors promoted glucocorticoid-induced apoptosis in cells carrying gain of function mutations in Notch1. Moreover, ectopic expression of constitutively activated Notch provided protection against glucocorticoid-induced apoptosis, indicating that signalling via Notch may also contribute to the development of T-ALL by conferring resistance to apoptosis. Microarray analysis revealed that GIMAP5, a gene coding for an anti-apoptotic intracellular protein, is upregulated by Notch in T-ALL cell lines. Knockdown of GIMAP5 expression using siRNA promoted glucocorticoid-induced apoptosis in T-ALL cells carrying gain of function mutations in Notch1 and in T-ALL cells engineered to express ectopic constitutively activated Notch indicating that Notch signalling protects T-ALL cells from apoptosis by upregulating the expression of GIMAP5.
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GIMAP Proteins in T-Lymphocytes. JOURNAL OF SIGNAL TRANSDUCTION 2010; 2010:268589. [PMID: 21637352 PMCID: PMC3100574 DOI: 10.1155/2010/268589] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 06/16/2010] [Indexed: 12/21/2022]
Abstract
(GIMAPs) GTPase of the immunity associated protein family are a novel protein family of putative small GTPases. GIMAPs are mainly expressed in the cells of the immune system and have been associated with immunological functions, such as thymocyte development, apoptosis of peripheral lymphocytes and T helper cell differentiation. GIMAPs have also been linked to immunological diseases, such as T cell lymphopenia, leukemia and autoimmune diseases. In this review we examine the role of GIMAP proteins in T-lymphocyte biology.
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Wong VW, Saunders AE, Hutchings A, Pascall JC, Carter C, Bright NA, Walker SA, Ktistakis NT, Butcher GW. The autoimmunity-related GIMAP5 GTPase is a lysosome-associated protein. SELF NONSELF 2010; 1:259-268. [PMID: 21487483 DOI: 10.4161/self.1.3.12819] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 06/25/2010] [Accepted: 06/25/2010] [Indexed: 12/18/2022]
Abstract
A mutation in the rat GIMAP5 gene predisposes for autoimmunity, most famously in the BB rat model of autoimmune type 1 diabetes mellitus. This mutation is associated with severe peripheral T lymphopenia, as is mutation of the same gene in mice, but the mechanism by which GIMAP5 normally protects T cells from death is unknown. GIMAP5 is a putative small GTPase, a class of proteins which often fulfil their functions in the vicinity of cellular membranes. The objective of this study was to determine the normal intracellular location of GIMAP5 in lymphoid cells. Combining studies in rat, mouse and human systems, novel monoclonal antibodies (mAbs) were used to examine the localization of GIMAP5 and the closely-related protein, GIMAP1, in lymphoid cells by means of confocal microscopy and sub-cellular fractionation combined with immunoblotting. Additionally, human Jurkat T cells that inducibly express epitope-tagged GIMAP5 were established and used in electron microscopy (EM). Endogenous GIMAP5 was found to be located in a membraneous compartment/s which was also detected by established markers of lysosomes. GIMAP1, by contrast, was found to be located in the Golgi apparatus. EM studies of the inducible Jurkat T cells also found GIMAP5 in lysosomes and, in addition, in multivesicular bodies. This study establishes that the endogenous location of GIMAP5 is in lysosomes and related compartments and provides a clearer context for hypotheses about its mechanism of action.
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Affiliation(s)
- Vivian Wy Wong
- Immunology Programme, The Babraham Institute, Cambridge, UK
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Moralejo DH, Hansen CT, Treuting P, Hessner MJ, Fuller JM, Van Yserloo B, Jensen R, Osborne W, Kwitek AE, Lernmark A. Differential effects of leptin receptor mutation on male and female BBDR Gimap5-/Gimap5- spontaneously diabetic rats. Physiol Genomics 2009; 41:9-20. [PMID: 19996157 DOI: 10.1152/physiolgenomics.00186.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Rodents homozygous for autosomal leptin receptor gene mutations not only become obese, insulin resistant, and hyperleptinemic but also develop a dysregulated immune system. Using marker-assisted breeding to introgress the Koletsky rat leptin receptor mutant (lepr-/lepr-), we developed a novel congenic BBDR.(lepr-/lepr-) rat line to study the development of obesity and type 2 diabetes (T2D) in the BioBreeding (BB) diabetes-resistant (DR) rat. While heterozygous lepr (-/+) or homozygous (+/+) BBDR rats remained lean and metabolically normal, at 3 wk of age all BBDR.(lepr-/lepr-) rats were obese without hyperglycemia. Between 45 and 70 days of age, male but not female obese rats developed T2D. We had previously developed congenic BBDR.(Gimap5-/Gimap5-) rats, which carry an autosomal frameshift mutation in the Gimap5 gene linked to lymphopenia and spontaneous development of type 1 diabetes (T1D) without sex differences. Because the autoimmune-mediated destruction of pancreatic islet beta-cells may be affected not only by obesity but also by the absence of leptin receptor signaling, we next generated BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) double congenic rats carrying the mutation for Gimap5 and T1D as well as the Lepr mutation for obesity and T2D. The hyperleptinemia rescued end-stage islets in BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats and induced an increase in islet size in both sexes, while T1D development was delayed and reduced only in females. These results demonstrate that obesity and T2D induced by introgression of the Koletsky leptin receptor mutation in the BBDR rat result in islet expansion associated with protection from T1D in female but not male BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats. BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats should prove valuable to study interactions between lack of leptin receptor signaling, obesity, and sex-specific T2D and T1D.
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Affiliation(s)
- Daniel H Moralejo
- Departments of Comparative Medicine, University of Washington, Seattle, Washington 98195, USA.
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Chadwick N, Zeef L, Portillo V, Fennessy C, Warrander F, Hoyle S, Buckle AM. Identification of novel Notch target genes in T cell leukaemia. Mol Cancer 2009; 8:35. [PMID: 19508709 PMCID: PMC2698846 DOI: 10.1186/1476-4598-8-35] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 06/09/2009] [Indexed: 11/30/2022] Open
Abstract
Background Dysregulated Notch signalling is believed to play an important role in the development and maintenance of T cell leukaemia. At a cellular level, Notch signalling promotes proliferation and inhibits apoptosis of T cell acute lymphoblastic leukaemia (T-ALL) cells. In this study we aimed to identify novel transcriptional targets of Notch signalling in the T-ALL cell line, Jurkat. Results RNA was prepared from Jurkat cells retrovirally transduced with an empty vector (GFP-alone) or vectors containing constitutively active forms of Notch (N1ΔE or N3ΔE), and used for Affymetrix microarray analysis. A subset of genes found to be regulated by Notch was chosen for real-time PCR validation and in some cases, validation at the protein level, using several Notch-transduced T-ALL and non-T-ALL leukaemic cell lines. As expected, several known transcriptional target of Notch, such as HES1 and Deltex, were found to be overexpressed in Notch-transduced cells, however, many novel transcriptional targets of Notch signalling were identified using this approach. These included the T cell costimulatory molecule CD28, the anti-apoptotic protein GIMAP5, and inhibitor of DNA binding 1 (1D1). Conclusion The identification of such downstream Notch target genes provides insights into the mechanisms of Notch function in T cell leukaemia, and may help identify novel therapeutic targets in this disease.
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Affiliation(s)
- Nicholas Chadwick
- Faculty of Life Sciences, Manchester Interdisciplinary Biocenter, University of Manchester, Manchester, UK.
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Pino SC, O'Sullivan-Murphy B, Lidstone EA, Yang C, Lipson KL, Jurczyk A, diIorio P, Brehm MA, Mordes JP, Greiner DL, Rossini AA, Bortell R. CHOP mediates endoplasmic reticulum stress-induced apoptosis in Gimap5-deficient T cells. PLoS One 2009; 4:e5468. [PMID: 19424493 PMCID: PMC2674944 DOI: 10.1371/journal.pone.0005468] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 04/05/2009] [Indexed: 11/25/2022] Open
Abstract
Gimap5 (GTPase of the immunity-associated protein 5) has been linked to the regulation of T cell survival, and polymorphisms in the human GIMAP5 gene associate with autoimmune disorders. The BioBreeding diabetes-prone (BBDP) rat has a mutation in the Gimap5 gene that leads to spontaneous apoptosis of peripheral T cells by an unknown mechanism. Because Gimap5 localizes to the endoplasmic reticulum (ER), we hypothesized that absence of functional Gimap5 protein initiates T cell death through disruptions in ER homeostasis. We observed increases in ER stress-associated chaperones in T cells but not thymocytes or B cells from Gimap5−/− BBDP rats. We then discovered that ER stress-induced apoptotic signaling through C/EBP-homologous protein (CHOP) occurs in Gimap5−/− T cells. Knockdown of CHOP by siRNA protected Gimap5−/− T cells from ER stress-induced apoptosis, thereby identifying a role for this cellular pathway in the T cell lymphopenia of the BBDP rat. These findings indicate a direct relationship between Gimap5 and the maintenance of ER homeostasis in the survival of T cells.
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Affiliation(s)
- Steven C. Pino
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Bryan O'Sullivan-Murphy
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Erich A. Lidstone
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Chaoxing Yang
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Kathryn L. Lipson
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Agata Jurczyk
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Philip diIorio
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Michael A. Brehm
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - John P. Mordes
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Dale L. Greiner
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Aldo A. Rossini
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Rita Bortell
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Sequence variation and expression of the Gimap gene family in the BB rat. EXPERIMENTAL DIABETES RESEARCH 2009; 2009:835650. [PMID: 19421422 PMCID: PMC2676327 DOI: 10.1155/2009/835650] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Accepted: 02/08/2009] [Indexed: 11/18/2022]
Abstract
Positional cloning of lymphopenia (lyp) in the BB rat revealed a frameshift mutation in Gimap5, a member of at least seven related GTPase Immune Associated Protein genes located on rat chromosome 4q24. Our aim was to clone and sequence the cDNA of the BB diabetes prone (DP) and diabetes resistant (DR) alleles of all seven Gimap genes in the congenic DR.lyp rat line with 2 Mb of BB DP DNA introgressed onto the DR genetic background. All (100%) DR.lyp/lyp rats are lymphopenic and develop type 1 diabetes (T1D) by 84 days of age while DR.+/+ rats remain T1D and lyp resistant. Among the seven Gimap genes, the Gimap5 frameshift mutation, a mutant allele that produces no protein, had the greatest impact on lymphopenia in the DR.lyp/lyp rat. Gimap4 and Gimap1 each had one amino acid substitution of unlikely significance for lymphopenia. Quantitative RT-PCR analysis showed a reduction in expression of all seven Gimap genes in DR.lyp/lyp spleen and mesenteric lymph nodes when compared to DR.+/+. Only four; Gimap1, Gimap4, Gimap5, and Gimap9 were reduced in thymus. Our data substantiates the Gimap5 frameshift mutation as the primary defect with only limited contributions to lymphopenia from the remaining Gimap genes.
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Koziel J, Maciag-Gudowska A, Mikolajczyk T, Bzowska M, Sturdevant DE, Whitney AR, Shaw LN, DeLeo FR, Potempa J. Phagocytosis of Staphylococcus aureus by macrophages exerts cytoprotective effects manifested by the upregulation of antiapoptotic factors. PLoS One 2009; 4:e5210. [PMID: 19381294 PMCID: PMC2668171 DOI: 10.1371/journal.pone.0005210] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/18/2009] [Indexed: 12/26/2022] Open
Abstract
It is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these host cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis. To validate our hypothesis we first ascertained whether S. aureus infection could affect programmed cell death in human (hMDMs) and mouse (RAW 264.7) macrophages and, specifically, protect these cells against apoptosis. Our findings indicate that S. aureus-infected macrophages are more resistant to staurosporine-induced cell death than control cells, an effect partly mediated via the inhibition of cytochrome c release from mitochondria. Furthermore, transcriptome analysis of human monocyte-derived macrophages during S. aureus infection revealed a significant increase in the expression of antiapoptotic genes. This was confirmed by quantitative RT-PCR analysis of selected genes involved in mitochondria-dependent cell death, clearly showing overexpression of BCL2 and MCL1. Cumulatively, the results of our experiments argue that S. aureus is able to induce a cytoprotective effect in macrophages derived from different mammal species, which can prevent host cell elimination, and thus allow intracellular bacterial survival. Ultimately, it is our contention that this process may contribute to the systemic dissemination of S. aureus infection.
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Affiliation(s)
- Joanna Koziel
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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Ilangumaran S, Forand-Boulerice M, Bousquet SM, Savard A, Rocheleau P, Chen XL, Dupuis G, Poussier P, Boulay G, Ramanathan S. Loss of GIMAP5 (GTPase of immunity-associated nucleotide binding protein 5) impairs calcium signaling in rat T lymphocytes. Mol Immunol 2009; 46:1256-9. [DOI: 10.1016/j.molimm.2008.09.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 09/25/2008] [Accepted: 09/27/2008] [Indexed: 11/25/2022]
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Abstract
It is now apparent that naïve peripheral T cells are a dynamic population where active processes prevent inappropriate activation while supporting survival. The process of thymic education makes naïve peripheral T cells dependent on interactions with self-MHC for survival. However, as these signals can potentially result in inappropriate activation, various non-redundant, intrinsic negative regulatory molecules including Tob, Nfatc2, and Smad3 actively enforce T cell quiescence. Interactions among these pathways are only now coming to light and may include positive or negative crosstalk. In the case of positive crosstalk, self-MHC initiated signals and intrinsic negative regulatory factors may cooperate to dampen T cell activation and sustain peripheral tolerance in a binary fashion (on-off). In the case of negative crosstalk, self-MHC signals may promote survival through partial activation while intrinsic negative regulatory factors act as rheostats to restrain cell cycle entry and prevent T cells from crossing a threshold that would break tolerance.
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Affiliation(s)
- Jaime F Modiano
- Integrated Department of Immunology, University of Colorado-Denver, Denver, CO, USA.
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Impaired survival of peripheral T cells, disrupted NK/NKT cell development, and liver failure in mice lacking Gimap5. Blood 2008; 112:4905-14. [PMID: 18796632 DOI: 10.1182/blood-2008-03-146555] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The loss of Gimap5 (GTPase of the immune-associated protein 5) gene function is the underlying cause of lymphopenia and autoimmune diabetes in the BioBreeding (BB) rat. The in vivo function of murine gimap5 is largely unknown. We show that selective gene ablation of the mouse gimap5 gene impairs the final intrathymic maturation of CD8 and CD4 T cells and compromises the survival of postthymic CD4 and CD8 cells, replicating findings in the BB rat model. In addition, gimap5 deficiency imposes a block of natural killer (NK)- and NKT-cell differentiation. Development of NK/NKT cells is restored on transfer of gimap5(-/-) bone marrow into a wild-type environment. Mice lacking gimap5 have a median survival of 15 weeks, exhibit chronic hepatic hematopoiesis, and in later stages show pronounced hepatocyte apoptosis, leading to liver failure. This pathology persists in a Rag2-deficient background in the absence of mature B, T, or NK cells and cannot be adoptively transferred by transplanting gimap5(-/-) bone marrow into wild-type recipients. We conclude that mouse gimap5 is necessary for the survival of peripheral T cells, NK/NKT-cell development, and the maintenance of normal liver function. These functions involve cell-intrinsic as well as cell-extrinsic mechanisms.
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