Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To better clarify individual roles of interferon (IFN)-alpha and IFN-gamma in beta-cell pathology during the onset of type 1 diabetes mellitus, we compared the effects of these cytokines on insulin production and major histocompatibility complex (MHC) gene expression in pancreatic beta-cell lines. IFN-gamma but not IFN-alpha decreased secreted and intracellular insulin concentrations in betaTC6-F7 and betaTC3 cells. Likewise, IFN-gamma but not IFN-alpha treatment of beta-cells upregulated mRNA expression of MHC class IA antigen-processing genes and surface expression of class IA molecules. Alternatively, class IA MHC expression was upregulated by IFN-gamma and IFN-alpha in the P388D1 macrophage cell line. The observation of constitutive Ifn-alpha6 mRNA expression by a differentiated beta-cell line substantiates previous indications that local expression of IFN-alpha in islets may trigger insulitis. Evidence that IFN-gamma, a product of infiltrating leukocytes, directly decreases beta-cell glucose sensitivity and increases MHC class IA cell surface expression supports the postulate that IFN-gamma magnifies the insulitic process.
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PMID:Interferon-alpha and interferon-gamma differentially affect pancreatic beta-cell phenotype and function. 968 31

Susceptibility to the human autoimmune disease IDDM is strongly associated with those haplotypes of the major histocompatibility complex (MHC) carrying DQB1 alleles that do not encode aspartic acid at codon 57. Similarly, in a spontaneous animal model of this disease, the NOD mouse, the genes of the MHC play an important role in the development of diabetes. The DQB1 homolog in NOD mice, I-Ab(g7), encodes a histidine at codon 56 and a serine at codon 57, while all other known I-Ab alleles encode proline and aspartic acid, respectively, at these positions. We therefore mutated the NOD I-Ab allele to encode proline at position 56 and aspartic acid at position 57 and introduced this allele onto the NOD genetic background to study the effect of these substitutions on susceptibility to diabetes. No transgenic mice developed diabetes by 8 months of age, and transgenic mice had markedly reduced lymphocytic infiltration in the pancreas compared with nontransgenic littermates. Furthermore, splenocytes from transgenic mice failed to proliferate or secrete gamma-interferon in response to a panel of beta-cell autoantigens, although the mice did produce beta-cell specific antibodies. Interestingly, the proportion of IgG1 and IgE relative to IgG2a comprising these autoantibodies was much greater in transgenic mice compared with nontransgenic control mice. Finally, T-cells from transgenic mice inhibited the adoptive transfer of diabetes to irradiated recipients. This inhibition was partially reversed by treatment of the recipients with a combination of anti-interleukin (IL)-4 and anti-IL-10 monoclonal antibodies. Thus, a transgenic class II MHC allele encoding aspartic acid at B57 prevents diabetes, in part, by promoting the production of IL-4 and IL-10, which interfere with the effector phase of the diabetic process.
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PMID:Prevention of diabetes in NOD mice by a mutated I-Ab transgene. 975 94

Cytokines could contribute to beta-cell damage in Type I diabetes mellitus. The radical nitric oxide, generated by the inducible form of nitric oxide synthase (iNOS), is a potential mediator of cytokine-induced beta-cell dysfunction. In rat pancreatic islets and insulin-producing cell lines, interleukin-1beta (IL-1beta) induces expression of iNOS mRNA and increases NO production, an effect potentiated by interferon-gamma (IFN-gamma). In human islet cells both IL-1beta and IFN-gamma are required for iNOS expression. We have shown previously that both the transcription factors nuclear factor-kappaB (NF-kappaB) and interferon regulatory factor-1 (IRF-1) are activated by cytokines in rodent and human islets but there is no direct information on the regulation of the iNOS promoter in insulin-producing cells. We presently investigated the effects of cytokines on iNOS transcriptional regulation in both rat insulin-producing RINm5F cells and in primary FACS-purified rat beta cells. Transient transfection experiments with the 1.5-kb rat promoter region and 5' deletants of it showed that a distal region extending up to -1002 bp, and containing a distal and a proximal nuclear factor-kappaB (NF-kappaB) binding site, a gamma-interferon activated site (GAS) and two adjacent IFN-stimulated response elements (ISRE), is required for IL-1beta induction and IFN-gamma potentiation of iNOS activation. Site-mutation analysis showed that both the distal and proximal NF-kappaB and GAS are necessary for IL-1beta-induced iNOS expression in RINm5F cells. In these cells IFN-gamma potentiation is mostly mediated by GAS and ISRE, suggesting a role for the IFN-gamma-induced transcription factors Stat1alpha (which binds GAS) and IRF-1 (which binds ISRE), which may cooperate with NF-kappaB induced by IL-1beta for iNOS activation. In primary beta cells both NF-kappaB binding sites are required for IL-1beta-induced iNOS promoter activation. In these cells IFN-gamma neither increased IL-1beta-induced iNOS promoter activity nor iNOS mRNA expression but it induced a twofold increase in NO production. The present results unveiled the nature of the promoter binding sites necessary for iNOS expression in rodent beta cells. This information could be relevant for the development of new strategies aimed at preventing cytokine-induced iNOS expression and consequent beta-cell damage.
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PMID:Regulation by cytokines of the inducible nitric oxide synthase promoter in insulin-producing cells. 975 30

Type I diabetes mellitus is a chronic disorder that results from autoimmune destruction of the insulin-producing pancreatic beta cell. The non-obese diabetic mouse is a model of the human autoimmune disease Type I diabetes [1-3]. We have previously shown that ingested type 1 interferon inhibits chronic relapsing experimental autoimmune encephalomyelitis and the adoptive transfer of experimental autoimmune encephalomyelites by T cells, and decreases both antigen-specific and mitogen-induced pro-inflammatory cytokine secretion in this disorder. We therefore tried to determine whether ingested murine interferon alpha inhibits insulinitis and suppresses Type I diabetes mellitus in non-obese diabetic mice. Murine interferon alpha, given daily, decreased islet inflammation and suppressed diabetes. It increased the concanavalin A and ionomycin plus myristic acid palmitic ester-induced production of interleukin 4 and 10 and interferon gamma-secretion in spleen cells from treated mice. Adoptive transfer of unstimulated splenocytes secreting interleukin 4 and interleukin 10 from fed interferon alpha donors suppressed spontaneous diabetes mellitus in recipients. The protective effect of adoptively transferred unstimulated splenocytes shows the presence of ingested interferon alpha-activated regulatory splenic cell populations that may work via increased interleukin 4 or interleukin 10 production. Ingested interferon alpha administered during vulnerable periods in at-risk populations may potentially provide a continuous, convenient, non-toxic and effective treatment for Type I diabetes.
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PMID:Ingested interferon alpha suppresses type I diabetes in non-obese diabetic mice. 1009 98

The NOD mouse is a model of human IDDM, which is characterized by a cell-mediated autoimmune process resulting in spontaneous diabetes. Alpha-interferon (IFN-alpha) is thought to play a pathogenic role in this autoimmune process. We report that recombinant alpha-interferon (rIFN-alpha) administration decreases the development of spontaneous diabetes and the passive transfer of diabetes in NOD mice. Spontaneous diabetes was inhibited by IFN-alpha in a dose-dependent fashion. A dose of as little as 20 x 10(3) U inhibited diabetes development, while a dose of 100 x 10(3) U potently prevented diabetes (14% incidence vs. 70% incidence in control mice). Even at the termination of the experiment, nondiabetic mice administered rIFN-alpha maintained normal glucose tolerance. Islet inflammation was 65% lower in the pancreases of rIFN-alpha mice. rIFN-alpha administration decreased anti-islet effector cell bioactivity of spleen cells without inducing generalized immunosuppression. Passive transfer experiments demonstrated that the decreased anti-islet effector cell activity was not a direct action of rIFN-alpha on these cells. In conclusion, rIFN-alpha potently and paradoxically prevents diabetes by indirectly decreasing anti-islet effector cell activity and in turn the development of insulitis without inducing generalized immunosuppression. This work, which goes against our current understanding of the role of rIFN-alpha in autoimmunity, may have significant implications to further our understanding of the pathogenesis of IDDM and to further the development of novel modes to prevent the disease.
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PMID:Alpha-interferon inhibits the development of diabetes in NOD mice. 983 17

A mechanism of autoimmune destruction of islet beta-cells in type 1 diabetes has been proposed to be the binding of Fas ligand (FasL) on T-cells to Fas receptors on beta-cells. We investigated this proposal by examining the expression of FasL and Fas on islet-infiltrating T-cells and beta-cells in relation to beta-cell destruction in a syngeneic islet transplant model in NOD mice. Diabetic NOD mice were transplanted with syngeneic islets and injected with complete Freund's adjuvant, which prevented diabetes recurrence (nondestructive insulitis), and with phosphate-buffered saline, which did not (beta-cell destructive insulitis). Two-color immunohistochemical assays revealed that FasL was expressed on CD4+ T-cells, CD8+ T-cells, and beta-cells in islet grafts from both diabetic and normoglycemic mice, and the percentage of each type of cell that expressed FasL was greater in islet grafts from normoglycemic compared with diabetic mice. In contrast, Fas was expressed on CD4+ T-cells, CD8+ T-cells, and beta-cells in islet grafts from diabetic mice, but it was nearly or totally absent on these cells in islet grafts from normoglycemic mice. Similarly, polymerase chain reaction analysis of islet grafts revealed that Fas mRNA expression was significantly lower in islet grafts from normoglycemic compared with diabetic mice. Also, mRNA levels of interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma were significantly lower in islet grafts from normoglycemic mice. Finally, Fas was induced on NOD islet cells by incubation with IL-1beta, IFN-gamma, and the combination of IL-1beta, TNF-alpha, and IFN-gamma. These findings support the concept that cytokine-induced Fas receptor expression on islet beta-cells is a mechanism for their destruction by FasL-expressing CD4+ and CD8+ T-cells and, possibly, by FasL-expressing beta-cells themselves.
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PMID:Beta-cell destruction in NOD mice correlates with Fas (CD95) expression on beta-cells and proinflammatory cytokine expression in islets. 989 18

We report on a 36-year-old patient suffering from chronic hepatitis C. Because of elevated liver enzymes and histology showing chronic inflammation and periportal fibrosis, interferon-alpha (IFN) therapy was started with a dosage of 5 Mio units three times a week. Four months later the patient hat to be hospitalized due to the typical clinical features of a recent onset type 1 diabetes (BG > 300 mg/dl, HbA1c 9.6%, ketonuria). In serum samples prior to and following interferon therapy, we analyzed titers of diabetes-related autoantibodies responding to GAD65 (glutamic acid decarboxylase), IA2c (tyrosine phosphatase) and ICA (islet cell autoantibodies). While ICA were negative before starting therapy, IA2c-antibodies were highly elevated. In contrast. GAD65-antibodies were elevated only slightly over the cut-off of the assay before therapy (controlled by a second different RIA assay) and increased 100 fold during IFN-alpha treatment. Additionally thyroid antibodies appeared. After the end of the IFN therapy, GAD65- and IA2c antibodies remained on high levels and also ICA could now be found. The patient was positive for HLA-DR4. This case supports the hypothesis that IFN-alpha therapy may lead to an augmented autoimmune reaction against islet cell antigens resulting in the development of diabetes mellitus type 1, especially if there are other predisposing factors before IFN treatment. We further discuss the possible involvement of interferon-alpha in the pathogenesis of autoimmune diabetes with reference to recent studies.
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PMID:[Augmentation of the immune response to islet cell antigens with development of diabetes mellitus caused by interferon-alpha therapy in chronic hepatitis C]. 1023 96

Apoptosis has been identified as a mechanism of pancreatic islet beta-cell death in autoimmune diabetes. Proinflammatory cytokines are candidate mediators of beta-cell death in autoimmune diabetes, and these cytokines can induce beta-cell death by apoptosis. In the present study, we examined whether transfection of human islet beta-cells with an anti-apoptotic gene, bcl-2, can prevent cytokine-induced beta-cell destruction. Human islet beta-cells were transfected by a replication-defective herpes simplex virus (HSV) amplicon vector that expressed the bcl-2 gene (HSVbcl-2) and, as a control, the same HSV vector that expressed a beta-galactosidase reporter gene (HSVlac). Two-color immunohistochemical staining revealed that 95+/-3% of beta-cells transfected with HSVbcl-2 expressed Bcl-2 protein compared with 14+/-3% of beta-cells transfected with HSVlac and 19+/-4% of nontransfected beta-cells. The bcl-2-transfected beta-cells were fully protected from impaired insulin secretion and destruction resulting from incubation for 5 days with the cytokine combination of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. In addition, the bcl-2-transfected islet cells were significantly protected from cytokine-induced lipid peroxidation and DNA fragmentation. These results demonstrate that cytokine-induced beta-cell dysfunction and death involve mechanisms subject to regulation by an anti-apoptotic protein, Bcl-2. Therefore, bcl-2 gene therapy has the potential to protect human beta-cells in pancreatic islets, or islet grafts, from immune-mediated damage in type 1 diabetes.
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PMID:Transfection of human pancreatic islets with an anti-apoptotic gene (bcl-2) protects beta-cells from cytokine-induced destruction. 1034 8

Interleukin (IL)-13 is a cytokine primarily produced by the T-helper (Th)-2 subset of lymphocytes that possesses powerful anti-inflammatory properties. Here, we have evaluated the impact of IL-13 treatment on development of type 1 diabetes in diabetes-prone nonobese diabetic (NOD) mice. Prolonged treatment with recombinant human IL-13 (hIL-13) markedly diminished the incidence of spontaneous type 1 diabetes in the mice. Female NOD mice treated from age 5-16 weeks with hIL-13 also showed significantly milder insulitis than control mice. The preventive action of hIL-13 was associated with a slight but significant change from a type 1 to a type 2 cytokine response. Accordingly, splenic lymphoid cells (SLC) from hIL-13-treated mice secreted less interferon (IFN)-gamma upon ex vivo stimulation with Concanavalin A than controls, and anti-CD3 monoclonal antibody-induced activation of T-cells in vivo resulted in lower blood levels of IFN-gamma and tumor necrosis factor-alpha and augmented blood levels of IL-4 in NOD mice pretreated with hIL-13. hIL-13 treatment also increased the blood levels of IgE and inhibited the transfer of type 1 diabetes by spleen cells from a diabetic donor to irradiated recipients. Taken together, these data add hIL-13 to the list of cytokines capable of downregulating immunoinflammatory diabetogenic pathways in NOD mice, and further support the concept that IL-4-related anti-inflammatory cytokines might have a role in the prevention of type 1 diabetes.
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PMID:Interleukin-13 prevents autoimmune diabetes in NOD mice. 1042 68

The mechanism of protection from type 1 diabetes conferred by regulatory T-cells induced by oral insulin treatment of NOD mice is not well understood. We demonstrate that oral insulin feeding of NOD mice induces the function of insulin B-chain reactive CD4+ regulatory T-cells, which compete with diabetogenic effector T-cells for the recognition of insulin in NOD.Scid recipient mice. These effector T-cells become deprived of interleukin (IL)-2 and interferon (IFN)-gamma and are unable to expand and migrate to the pancreas. Type 1 diabetes-protective splenic regulatory T-cells secrete relatively little transforming growth factor (TGF)-beta1, suggesting that TGF-beta may not contribute to the inactivation of effector T-cells in NOD.Scid recipients. The observed preferential infiltration of insulin-reactive regulatory T-cells rather than effector T-cells in the pancreas results in a nondestructive insulitis that correlates with an increased intrapancreatic expression of macrophage inflammatory protein-1beta. Thus, oral insulin therapy overcomes a deficiency in regulatory T-cells and protects against type 1 diabetes by inducing insulin B-chain reactive regulatory T-cells to block cytokine secretion and migration of diabetogenic effector T-cells to the pancreas. Our data emphasize that continuous oral insulin feeding over a prolonged period is required to prevent type 1 diabetes.
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PMID:Insulin B-chain reactive CD4+ regulatory T-cells induced by oral insulin treatment protect from type 1 diabetes by blocking the cytokine secretion and pancreatic infiltration of diabetogenic effector T-cells. 1048 Jun


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