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Cao Y, Bao S, Yang W, Zhang J, Li L, Shan Z, Teng W. Epigallocatechin gallate prevents inflammation by reducing macrophage infiltration and inhibiting tumor necrosis factor-α signaling in the pancreas of rats on a high-fat diet. Nutr Res 2014; 34:1066-74. [DOI: 10.1016/j.nutres.2014.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/30/2014] [Accepted: 10/10/2014] [Indexed: 01/26/2023]
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102
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Zhang X, Shen J, Man K, Chu ESH, Yau TO, Sung JCY, Go MYY, Deng J, Lu L, Wong VWS, Sung JJY, Farrell G, Yu J. CXCL10 plays a key role as an inflammatory mediator and a non-invasive biomarker of non-alcoholic steatohepatitis. J Hepatol 2014; 61:1365-75. [PMID: 25048951 DOI: 10.1016/j.jhep.2014.07.006] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 06/14/2014] [Accepted: 07/06/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Perpetuate liver inflammation is crucial in the pathogenesis of non-alcoholic steatohepatitis (NASH). Expression of CXCL10, a pro-inflammatory cytokine, correlates positively with obesity and type 2 diabetes. Whether CXCL10 plays a role in NASH was unknown. We aimed to investigate the functional and clinical impact of CXCL10 in NASH. METHODS Cxcl10 gene-deleted (Cxcl10(-/-)) and C57BL/6 wild type (WT) mice were fed a methionine- and choline-deficient (MCD) diet for 4 or 8 weeks. In other experiments, we injected neutralizing anti-CXCL10 mAb into MCD-fed WT mice. Human serum was obtained from 147 patients with biopsy-proven non-alcoholic fatty liver disease and 73 control subjects. RESULTS WT mice, fed the MCD diet, developed steatohepatitis with higher hepatic CXCL10 expression. Cxcl10(-/-) mice were refractory to MCD-induced steatohepatitis. We further revealed that CXCL10 was associated with the induction of important pro-inflammatory cytokines (TNF-α, IL-1β, and MCP-1) and activation of the NF-κB pathway. CXCL10 was linked to steatosis through upregulation of the lipogenic factors SREBP-1c and LXR, and also to oxidative stress (upregulation of CYP2E1 and C/EBPβ). Blockade of CXCL10 protected against hepatocyte injury in vitro and against steatohepatitis development in mice. We further investigated the clinical impact of CXCL10 and found circulating and hepatic CXCL10 levels were significantly higher in human NASH. Importantly, the circulating CXCL10 level was correlated with the degree of lobular inflammation and was an independent risk factor for NASH patients. CONCLUSIONS We demonstrate for the first time that CXCL10 plays a pivotal role in the pathogenesis of experimental steatohepatitis. CXCL10 maybe a potential non-invasive biomarker for NASH patients.
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Affiliation(s)
- Xiang Zhang
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Jiayun Shen
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Kwan Man
- Department of Surgery, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Eagle S H Chu
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Tung On Yau
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Joanne C Y Sung
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Minnie Y Y Go
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jun Deng
- Department of Pathology and Center of Infection and Immunology, The University of Hong Kong, Hong Kong, China
| | - Liwei Lu
- Department of Pathology and Center of Infection and Immunology, The University of Hong Kong, Hong Kong, China
| | - Vincent W S Wong
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Joseph J Y Sung
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Geoffrey Farrell
- Australian National University Medical School at The Canberra Hospital, Canberra, Australia
| | - Jun Yu
- Institute of Digestive Disease and The Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China; Gastrointestinal Cancer Biology and Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
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Omar BA, Liehua L, Yamada Y, Seino Y, Marchetti P, Ahrén B. Dipeptidyl peptidase 4 (DPP-4) is expressed in mouse and human islets and its activity is decreased in human islets from individuals with type 2 diabetes. Diabetologia 2014; 57:1876-83. [PMID: 24939431 DOI: 10.1007/s00125-014-3299-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/28/2014] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Inhibition of the enzyme dipeptidyl peptidase 4 (DPP-4), which cleaves and inactivates glucagon-like peptide 1 (GLP-1), is a glucose-lowering strategy in type 2 diabetes. Since DPP-4 is a ubiquitously distributed enzyme, we examined whether it is expressed in islets and whether an islet effect to inhibit DPP-4 may result in stimulated insulin secretion. METHODS We investigated DPP-4 expression and activity in the islets of mouse models of obesity as well as human islets from non-diabetic and type 2 diabetic donors. We further investigated whether inhibition with DPP-4 inhibitors could promote insulin secretion via islet GLP-1 in isolated islets. RESULTS DPP-4 was readily detected in mouse and human islets with species-specific cellular localisation. In mice, DPP-4 was expressed predominantly in beta cells, whereas in humans it was expressed nearly exclusively in alpha cells. DPP-4 activity was significantly increased in islets from diet-induced obese mice compared with mice fed a control diet. In humans, DPP-4 activity was significantly lower in islets from type 2 diabetic donors than in non-diabetic donors. In human islets, there was a significant positive correlation between DPP-4 activity and insulin secretory response to 16.7 mmol/l glucose. Treatment of mouse islets with the DPP-4 inhibitors, NVPDPP728 and vildagliptin, resulted in a significant potentiation of insulin secretion in a GLP-1-dependent manner, as this was inhibited by the GLP-1 receptor antagonist, Exendin (9-39), and was retained in glucose-dependent insulinotropic polypeptide (GIP) receptor-deficient mice but lost in mice lacking GLP-1 receptors or both incretin receptors. Human islets treated with the DPP-4 inhibitor, vildagliptin, showed increased secretion of insulin and intact GLP-1. CONCLUSIONS/INTERPRETATION We conclude that DPP-4 is present and active in mouse and human islets, is regulated by the disease state, and that inhibition of islet DPP-4 activity can have direct effects on islet function. Inhibiting islet DPP-4 activity may therefore contribute to the insulin-secretory and glucose-lowering action of DPP-4 inhibition.
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Affiliation(s)
- Bilal A Omar
- Department of Clinical Sciences, Biomedical Center, C11, Lund University, SE22184, Lund, Sweden,
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104
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Burke SJ, Lu D, Sparer TE, Karlstad MD, Collier JJ. Transcription of the gene encoding TNF-α is increased by IL-1β in rat and human islets and β-cell lines. Mol Immunol 2014; 62:54-62. [PMID: 24972324 DOI: 10.1016/j.molimm.2014.05.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/08/2014] [Accepted: 05/24/2014] [Indexed: 11/28/2022]
Abstract
Synthesis and secretion of immunomodulatory proteins, such as cytokines and chemokines, controls the inflammatory response within pancreatic islets. When this inflammation does not resolve, destruction of pancreatic islet β-cells leads to diabetes mellitus. Production of the soluble mediators of inflammation, such as TNF-α and IL-1β, from resident and invading immune cells, as well as directly from islet β-cells, is also associated with suboptimal islet transplantation outcomes. In this study, we found that IL-1β induces rapid increases in TNF-α mRNA in rat and human islets and the 832/13 clonal β-cell line. The surge in transcription of the TNF-α gene required the inhibitor of kappa B kinase beta (IκKβ), the p65 subunit of the NF-κB and a signal-specific recruitment of RNA polymerase II to the gene promoter. Of note was the increased intracellular production of TNF-α protein in a manner consistent with mRNA accumulation in response to IL-1β, but no detectable secretion of TNF-α into the media. Additionally, TNF-α specifically induces expression of CD11b, but not CD11c, on neutrophils, which could contribute to the inflammatory milieu and diabetes progression. We conclude that activation of the NF-κB pathway in pancreatic β-cells leads to rapid intracellular production of the pro-inflammatory TNF-α protein through a combination of specific histone covalent modifications and NF-κB signaling pathways.
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Affiliation(s)
- Susan J Burke
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, United States
| | - Danhong Lu
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704, United States
| | - Tim E Sparer
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
| | - Michael D Karlstad
- Department of Surgery, Graduate School of Medicine, University of Tennessee Medical Center, Knoxville, TN 37920, United States
| | - J Jason Collier
- Laboratory of Islet Biology and Inflammation, Pennington Biomedical Research Center, Baton Rouge, LA 70808, United States.
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105
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Horiguchi K, Fujiwara K, Higuchi M, Yoshida S, Tsukada T, Ueharu H, Chen M, Hasegawa R, Takigami S, Ohsako S, Yashiro T, Kato T, Kato Y. Expression of chemokine CXCL10 in dendritic-cell-like S100β-positive cells in rat anterior pituitary gland. Cell Tissue Res 2014; 357:757-65. [PMID: 24770897 DOI: 10.1007/s00441-014-1864-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 02/26/2014] [Indexed: 12/30/2022]
Abstract
Chemokines are mostly small secreted polypeptides whose signals are mediated by seven trans-membrane G-protein-coupled receptors. Their functions include the control of leukocytes and the intercellular mediation of cell migration, proliferation, and adhesion in several tissues. We have previously revealed that the CXC chemokine ligand 12 (CXCL12) and its receptor 4 (CXCR4) are expressed in the anterior pituitary gland, and that the CXCL12/CXCR4 axis evokes the migration and interconnection of S100β-protein-positive cells (S100β-positive cells), which do not produce classical anterior pituitary hormones. However, little is known of the cells producing the other CXCLs and CXCRs or of their characteristics in the anterior pituitary. We therefore examined whether CXCLs and CXCRs occurred in the rat anterior pituitary lobe. We used reverse transcription plus the polymerase chain reaction to analyze the expression of Cxcl and Cxcr and identified the cells that expressed Cxcl by in situ hybridization. Transcripts of Cxcl10 and its receptor (Cxcr3 and toll-like receptor 4, Tlr4) were clearly detected: cells expressing Cxcl10 and Tlr4 were identified amongst S100β-positive cells and those expressing Cxcr3 amongst adrenocorticotropic hormone (ACTH)-producing cells. We also investigated Cxcl10 expression in subpopulations of S100β-positive cells. We separated cultured S100β-positive cells into the round-type (dendritic-cell-like) and process-type (astrocyte- or epithelial-cell-like) by their adherent activity to laminin, a component of the extracellular matrix; CXCL10 was expressed only in round-type S100β-positive cells. Thus, CXCL10 produced by a subpopulation of S100β-positive cells probably exerts an autocrine/paracrine effect on S100β-positive cells and ACTH-producing cells in the anterior lobe.
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Affiliation(s)
- Kotaro Horiguchi
- Laboratory of Anatomy and Cell Biology, Department of Health Sciences, Kyorin University, Tokyo, Japan
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106
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Gülden E, Wen L. Toll-Like Receptor Activation in Immunity vs. Tolerance in Autoimmune Diabetes. Front Immunol 2014; 5:119. [PMID: 24715890 PMCID: PMC3970021 DOI: 10.3389/fimmu.2014.00119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/07/2014] [Indexed: 12/21/2022] Open
Affiliation(s)
- Elke Gülden
- Section of Endocrinology, Yale University School of Medicine , New Haven, CT , USA
| | - Li Wen
- Section of Endocrinology, Yale University School of Medicine , New Haven, CT , USA
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Ardestani A, Paroni F, Azizi Z, Kaur S, Khobragade V, Yuan T, Frogne T, Tao W, Oberholzer J, Pattou F, Conte JK, Maedler K. MST1 is a key regulator of beta cell apoptosis and dysfunction in diabetes. Nat Med 2014; 20:385-397. [PMID: 24633305 PMCID: PMC3981675 DOI: 10.1038/nm.3482] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/21/2014] [Indexed: 12/31/2022]
Abstract
Apoptotic cell death is a hallmark of the loss of insulin producing beta-cells in all forms of diabetes mellitus. Current treatment fails to halt the decline in functional beta-cell mass. Strategies to prevent beta-cell apoptosis and dysfunction are urgently needed. Here, we identified Mammalian Sterile 20-like kinase 1 (MST1) as a critical regulator of apoptotic beta-cell death and function. MST1 was strongly activated in beta-cells under diabetogenic conditions and correlated with beta-cell apoptosis. MST1 specifically induced the mitochondrial-dependent pathway of apoptosis in beta-cells through up-regulation of the BH3-only protein Bim. MST1 directly phosphorylated PDX1 at Thr11, resulting in its ubiquitination, degradation and impaired insulin secretion. Mst1 deficiency completely restored normoglycemia, beta-cell function and survival in vitro and in vivo. We show MST1 as novel pro-apoptotic kinase and key mediator of apoptotic signaling and beta-cell dysfunction, which may serve as target for the development of novel therapies for diabetes.
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Affiliation(s)
- Amin Ardestani
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | - Federico Paroni
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | - Zahra Azizi
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | - Supreet Kaur
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | | | - Ting Yuan
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | - Thomas Frogne
- Department of Beta-cell Regeneration, Hagedorn Research Institute, Gentofte, Denmark
| | - Wufan Tao
- Institute of Developmental Biology and Molecular Medicine, Fudan University, Shanghai, China
| | - Jose Oberholzer
- Division of Transplantation, University of Illinois at Chicago, IL, USA
| | - Francois Pattou
- Thérapie Cellulaire du Diabète, INSERM /Université de Lille Nord de France, France
| | - Julie Kerr Conte
- Thérapie Cellulaire du Diabète, INSERM /Université de Lille Nord de France, France
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
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108
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Mayer L, Sandborn WJ, Stepanov Y, Geboes K, Hardi R, Yellin M, Tao X, Xu LA, Salter-Cid L, Gujrathi S, Aranda R, Luo AY. Anti-IP-10 antibody (BMS-936557) for ulcerative colitis: a phase II randomised study. Gut 2014; 63:442-50. [PMID: 23461895 PMCID: PMC3933070 DOI: 10.1136/gutjnl-2012-303424] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Interferon-γ-inducible protein-10 (IP-10 or CXCL10) plays a role in inflammatory cell migration and epithelial cell survival and migration. It is expressed in higher levels in the colonic tissue and plasma of patients with ulcerative colitis (UC). This phase II study assessed the efficacy and safety of BMS-936557, a fully human, monoclonal antibody to IP-10, in the treatment of moderately-to-severely active UC. DESIGN In this 8-week, phase II, double-blind, multicentre, randomised study, patients with active UC received placebo or BMS-936557 (10 mg/kg) intravenously every other week. The primary endpoint was the rate of clinical response at Day 57; clinical remission and mucosal healing rates were secondary endpoints. Post hoc analyses evaluated the drug exposure-response relationship and histological improvement. RESULTS 109 patients were included (BMS-936557: n=55; placebo: n=54). Prespecified primary and secondary endpoints were not met; clinical response rate at Day 57 was 52.7% versus 35.2% for BMS-936557 versus placebo (p=0.083), and clinical remission and mucosal healing rates were 18.2% versus 16.7% (p=1.00) and 41.8% versus 35.2% (p=0.556), respectively. However, higher BMS-936557 steady-state trough concentration (Cminss) was associated with increased clinical response (87.5% vs 37.0% (p<0.001) for patients with Cminss 108-235 μg/ml vs placebo) and histological improvements (73.0% vs 41.0%; p=0.004). Infections occurred in 7 (12.7%) BMS-936557-treated patients and 3 (5.8%) placebo-treated patients. 2 (3.6%) BMS-936557 patients discontinued due to adverse events. CONCLUSIONS Anti-IP-10 antibody, BMS-936557, is a potentially effective therapy for moderately-to-severely active UC. Higher drug exposure correlated with increasing clinical response and histological improvement. Further dose-response studies are warranted. CLINICAL TRIAL REGISTRATION NUMBER ClinicalTrials.gov NCT00656890.
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Affiliation(s)
- Lloyd Mayer
- Immunology Institute, Mount Sinai School of Medicine, New York, New York, USA
| | - William J Sandborn
- Division of Gastroenterology, University of California San Diego, La Jolla, California, USA
| | - Yuriy Stepanov
- Dnipropetrovsk State Medical Academy, Dnipropetrovsk, Ukraine
| | - Karel Geboes
- Department of Pathologie, University Hospital KU Leuven, Leuven, Belgium
| | - Robert Hardi
- Chevy Chase Clinical Research, Chevy Chase, Maryland, USA
| | | | - Xiaolu Tao
- Bristol-Myers Squibb, Princeton, New Jersey, USA
| | - Li An Xu
- Bristol-Myers Squibb, Princeton, New Jersey, USA
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109
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Toll-like receptors and NLRP3 as central regulators of pancreatic islet inflammation in type 2 diabetes. Immunol Cell Biol 2014; 92:314-23. [PMID: 24492799 DOI: 10.1038/icb.2014.4] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 12/17/2022]
Abstract
The global health and economic burden of type 2 diabetes (T2D) has reached staggering proportions. Current projections estimate that 592 million people will have diabetes by 2035. T2D-which comprises 90% of cases-is a complex disease, in most cases resulting from a combination of predisposing genes and an unhealthy environment. Clinical onset of the disease occurs when pancreatic β cells fail in the face of insulin resistance. It has long been appreciated that chronic activation of the innate immune system is associated with T2D, and many organs critical to the regulation of glucose homeostasis show signs of a chronic inflammatory process, including the pancreatic islets of Langerhans. Recent clinical trials using IL-1-targeting agents have confirmed that inflammation contributes to β-cell failure in humans with T2D. However, little is known about the nature of the pro-inflammatory response within the islet, and there is considerable debate about the triggers for islet inflammation, which may be systemically derived and/or tissue-specific. In this review, we present evidence that Toll-like receptors 2 and 4 and the NLRP3 (Nucleotide-binding oligomerization domain, Leucine-rich Repeat and Pyrin domain containing 3) inflammasome are triggers for islet inflammation in T2D and propose that the activation of macrophages by these triggers mediates islet endocrine cell dysfunction. Therapeutically targeting these receptors may improve hyperglycemia and protect the β cell in T2D.
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110
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Milicic T, Jotic A, Markovic I, Lalic K, Jeremic V, Lukic L, Rajkovic N, Popadic D, Macesic M, Seferovic JP, Aleksic S, Stanarcic J, Civcic M, Lalic NM. High Risk First Degree Relatives of Type 1 Diabetics: An Association with Increases in CXCR3(+) T Memory Cells Reflecting an Enhanced Activity of Th1 Autoimmune Response. Int J Endocrinol 2014; 2014:589360. [PMID: 24778649 PMCID: PMC3979071 DOI: 10.1155/2014/589360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 02/10/2014] [Accepted: 02/10/2014] [Indexed: 01/14/2023] Open
Abstract
We analyzed the level of (a) CXCR3(+) (Th1) and CCR4(+) (Th2) T memory cells (b) interferon- γ inducible chemokine (IP-10)(Th1) and thymus and activation-regulated chemokine (TARC)(Th2), in 51 first degree relatives (FDRs) of type 1 diabetics (T1D) (17 high risk FDRs (GADA(+), IA-2(+)) and 34 low risk FDRs (GADA(-), IA-2(-))), 24 recent-onset T1D (R-T1D), and 18 healthy subjects. T memory subsets were analyzed by using four-color immunofluorescence staining and flowcytometry. IP-10 and TARC were determined by ELISA. High risk FDRs showed higher levels of CXCR3(+) and lower level of CCR4(+) T memory cells compared to low risk FDRs (64.98 ± 5.19 versus 42.13 ± 11.11; 29.46 ± 2.83 versus 41.90 ± 8.58%, resp., P < 0.001). Simultaneously, both IP-10 and TARC levels were increased in high risk versus low risk FDRs (160.12 ± 73.40 versus 105.39 ± 71.30; 438.83 ± 120.62 versus 312.04 ± 151.14 pg/mL, P < 0.05). Binary logistic regression analysis identified the level of CXCR3(+) T memory cells as predictors for high risk FDRs, together with high levels of IP-10. The results imply that, in FDRs, the risk for T1D might be strongly influenced by enhanced activity of Th1 and diminished activity of Th2 autoimmune response.
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Affiliation(s)
- Tanja Milicic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Aleksandra Jotic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Ivanka Markovic
- Institute for Biochemistry, Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia
| | - Katarina Lalic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Veljko Jeremic
- Department for Operations Research and Statistics, Faculty of Organizational Sciences, University of Belgrade, Jove Ilica 154, Belgrade, Serbia
| | - Ljiljana Lukic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Natasa Rajkovic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Dušan Popadic
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia
| | - Marija Macesic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Jelena P. Seferovic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Sandra Aleksic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Jelena Stanarcic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Milorad Civcic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
| | - Nebojsa M. Lalic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 13, 11000 Belgrade, Serbia
- *Nebojsa M. Lalic:
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111
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Hoffmeister A, Tuennemann J, Sommerer I, Mössner J, Rittger A, Schleinitz D, Kratzsch J, Rosendahl J, Klöting N, Stahl T, Rossner S, Paroni F, Maedler K, Kovacs P, Blüher M. Genetic and biochemical evidence for a functional role of BACE1 in the regulation of insulin mRNA expression. Obesity (Silver Spring) 2013; 21:E626-33. [PMID: 23596049 DOI: 10.1002/oby.20482] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 03/18/2013] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Beta-site amyloid precursor protein cleaving enzyme (BACE1) is highly expressed in pancreatic β-cells. The BACE1 gene is located in a region associated with a high diabetes risk in PIMA Indians. DESIGN AND METHODS INS-1E cells were used to study the impact of siRNA-mediated BACE1 knockdown and glucose metabolism was characterized in Bace1(-/-) mice. BACE1 gene was sequenced in DNA samples from 48 subjects and 13 representative single nucleotide polymorphisms (SNPs) were then genotyped for association studies in 1,527 Caucasians. RESULTS Reduction of Bace1 expression results in a significant decrease in insulin mRNA expression in INS-1E cells. Bace1(-/-) mice display significantly lower body weight, lower plasma insulin concentrations, but normal glucose tolerance and insulin sensitivity. In a case-control study including 538 healthy controls and 989 patients with type 2 diabetes (T2D), one SNP (rs535860) was significantly associated with T2D (P < 3.5 × 10(-5) , adjusted for age, sex, and BMI). CONCLUSIONS Reduced Bace1 expression causes impaired insulin expression in pancreatic β-cells of Bace1(-/-) mice, suggesting that BACE1 plays a role in the regulation of insulin biogenesis. The functionally relevant rs535860 SNP may decrease BACE1 expression by creating a new miR-661 binding site and could therefore contribute to T2D development.
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Xie BG, Jin S, Zhu WJ. Expression of toll-like receptor 4 in maternal monocytes of patients with gestational diabetes mellitus. Exp Ther Med 2013; 7:236-240. [PMID: 24348797 PMCID: PMC3861517 DOI: 10.3892/etm.2013.1360] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 10/21/2013] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors and play an important role in innate immune responses and the occurrence of inflammatory disease. TLR4 is a member of the TLR family and its activation is capable of inducing inflammatory responses, reflecting a relationship between the innate and adaptive immune systems. However, whether TLR4 is expressed in patients with gestational diabetes mellitus (GDM) has not been elucidated. The aim of the present study was to investigate whether TLR4 is expressed in maternal peripheral blood monocytes of patients with GDM. A case-control study, using standard quantitative polymerase chain reaction and western blotting, was performed to assess the TLR4 expression in 30 females with GDM and 32 healthy pregnant females at similar gestational ages. Serum tumor necrosis factor (TNF)-α levels were assessed using ELISA in all the females. The TLR4 expression levels in the maternal peripheral blood monocytes and the serum TNF-α levels were increased in females with GDM compared with healthy pregnant females (P<0.05). Additionally, there was a positive correlation between the TLR4 expression level in peripheral blood monocytes and serum TNF-α levels in all the females. These results indicate that TLR4-mediated release of inflammatory cytokines may represent one factor leading to increased glucose levels in patients with GDM. In addition, TLR4 may be involved in the pathogenesis of GDM.
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Affiliation(s)
- Bao-Guo Xie
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Song Jin
- Department of Obstetrics and Gynecology, Affiliated Hospital of Hainan Medical College, Haikou, Hainan 570102, P.R. China
| | - Wei-Jie Zhu
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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113
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Gülden E, Ihira M, Ohashi A, Reinbeck AL, Freudenberg MA, Kolb H, Burkart V. Toll-like receptor 4 deficiency accelerates the development of insulin-deficient diabetes in non-obese diabetic mice. PLoS One 2013; 8:e75385. [PMID: 24086519 PMCID: PMC3781027 DOI: 10.1371/journal.pone.0075385] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 08/14/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND/OBJECTIVE Toll-like receptors (TLR) mediate the recognition of microbial constituents and stress-induced endogenous ligands by the immune system. They may also be involved in the maintenance or break down of tolerance against autologous antigens. The aim of our investigation was to study the consequence of TLR4 deficiency on the development of insulin-deficient diabetes in the NOD mouse. METHODS The TLR4 defect of the C57BL/10ScN mouse was backcrossed onto the NOD background and the effect of TLR4 deficiency on diabetes development was analysed by in vivo and in vitro studies. RESULTS Compared to animals with wildtype TLR4 expression (TLR4(+/+)), female NOD mice carrying a homozygous TLR4 defect (TLR4(-/-)), showed significant acceleration of diabetes development, with a younger age at diabetes onset (TLR4 (+/+) 177±22 d, TLR(-/-): 118±21 d; p<0.01). Pancreata of 120 d old TLR4(-/-) NOD mice revealed increased proportions of islets with advanced stages of immune cell infiltration compared to TLR4(+/+) mice (p<0.05). TLR4 deficiency did not affect the susceptibility of islet cells to the beta cell damaging mediators nitric oxide or the inflammatory cytokines tumor necrosis factor alpha, interleukin-1 beta and interferon gamma. The lack of TLR4 further had no effect on the frequency of regulatory T-cells but reduced their capacity to inhibit T-cell proliferation. CONCLUSIONS Our findings demonstrate that TLR4 deficiency results in an acceleration of diabetes development and immune cell infiltration of islets in NOD mice. We conclude that TLR4 is involved in the progression of the insulitis process thereby controlling the development of insulin-deficient diabetes in NOD mice.
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Affiliation(s)
- Elke Gülden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
| | - Masaru Ihira
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
| | - Atsushi Ohashi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
| | - Anna Lena Reinbeck
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
| | - Marina A. Freudenberg
- Department of Developmental Immunology, Max-Planck-Institute of Immunbiology and Epigenetics, Freiburg, Germany
| | - Hubert Kolb
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
| | - Volker Burkart
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Member of the German Center for Diabetes Research (DZD), Düsseldorf, Germany
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114
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Induction of an inflammatory loop by interleukin-1β and tumor necrosis factor-α involves NF-kB and STAT-1 in differentiated human neuroprogenitor cells. PLoS One 2013; 8:e69585. [PMID: 23922745 PMCID: PMC3726669 DOI: 10.1371/journal.pone.0069585] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/12/2013] [Indexed: 12/04/2022] Open
Abstract
Proinflammatory cytokines secreted from microglia are known to induce a secondary immune response in astrocytes leading to an inflammatory loop. Cytokines also interfere with neurogenesis during aging and in neurodegenerative diseases. The present study examined the mechanism of induction of inflammatory mediators at the transcriptional level in human differentiated neuroprogenitor cells (NPCs). Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) induced the expression of cytokines and chemokines in differentiated human NPCs as shown by an immune pathway-specific array. Network motif (NM) analysis of these genes revealed 118 three-node NMs, suggesting complex interactions between inflammatory mediators and transcription factors. Immunofluorescent staining showed increases in the levels of IL-8 and CXCL10 proteins in neurons and glial cells. Findings from Taqman low density array suggested the synergistic actions of IL-1β and TNF-α in the induction of a majority of inflammatory genes by a mechanism involving NF-kB and STAT-1. Nuclear localization of these transcription factors in differentiated NPCs was observed following exposure to IL-1α and TNF-α. Further studies on CXCL10, a chemokine known to be elevated in the Alzheimer's brain, showed that TNF-α is a stronger inducer of CXCL10 promoter when compared to IL-1β. The synergy between these cytokines was lost when ISRE or kB elements in CXCL10 promoter were mutated. Our findings suggest that the activation of inflammatory pathways in neurons and astrocytes through transcription factors including NF-kB and STAT-1 play important roles in neuroglial interactions and in sustaining the vicious cycle of inflammatory response.
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Velecela V, Lettice LA, Chau YY, Slight J, Berry RL, Thornburn A, Gunst QD, van den Hoff M, Reina M, Martínez FO, Hastie ND, Martínez-Estrada OM. WT1 regulates the expression of inhibitory chemokines during heart development. Hum Mol Genet 2013; 22:5083-95. [PMID: 23900076 DOI: 10.1093/hmg/ddt358] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The embryonic epicardium is an important source of cardiovascular precursor cells and paracrine factors that are required for adequate heart formation. Signaling pathways regulated by WT1 that promote heart development have started to be described; however, there is little information on signaling pathways regulated by WT1 that could act in a negative manner. Transcriptome analysis of Wt1KO epicardial cells reveals an unexpected role for WT1 in repressing the expression of interferon-regulated genes that could be involved in a negative regulation of heart morphogenesis. Here, we showed that WT1 is required to repress the expression of the chemokines Ccl5 and Cxcl10 in epicardial cells. We observed an inverse correlation of Wt1 and the expression of Cxcl10 and Ccl5 during epicardium development. Chemokine receptor analyses of hearts from Wt1(gfp/+) mice demonstrate the differential expression of their chemokine receptors in GFP(+) epicardial enriched cells and GFP(-) cells. Functional assays demonstrate that CXCL10 and CCL5 inhibit epicardial cells migration and the proliferation of cardiomyocytes respectively. WT1 regulates the expression levels of Cxcl10 and Ccl5 in epicardial cells directly and indirectly through increasing the levels of IRF7. As epicardial cell reactivation after a myocardial damage is linked with WT1 expression, the present work has potential implications in adult heart repair.
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Affiliation(s)
- Victor Velecela
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Edinburgh EH4 2XU, UK
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Shah P, Ardestani A, Dharmadhikari G, Laue S, Schumann DM, Kerr-Conte J, Pattou F, Klein T, Maedler K. The DPP-4 inhibitor linagliptin restores β-cell function and survival in human isolated islets through GLP-1 stabilization. J Clin Endocrinol Metab 2013; 98:E1163-72. [PMID: 23633194 DOI: 10.1210/jc.2013-1029] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CONTEXT Inhibition of dipeptidyl peptidase-4 (DPP-4) is a potent strategy to increase glucose-dependent insulinotropic polypeptide and glucagon like peptide 1 (GLP-1) induced insulin secretion in diabetes. It is important to know whether new drugs approved for the treatment of type 2 diabetes have direct effects on the β-cell. OBJECTIVE Herein we investigated the effect of linagliptin, a novel DPP-4 inhibitor, on β-cell function and survival. DESIGN Human islets were exposed to a diabetic milieu (11.1-33.3 mM glucose, 0.5 mM palmitate, the mixture of 2 ng/mL IL-1β+1000 U/mL interferon-γ, or 50 μM H₂O₂) with or without 500 ng/mL IL-1 receptor antagonist (IL-1Ra) or 30-50 nM linagliptin. RESULTS Linagliptin restored β-cell function and turnover, which was impaired when islets were exposed to elevated glucose, palmitate, cytokines, or H₂O₂. Pretreatment with IL-1Ra was similarly effective, except against H₂O₂ treatment. Nitrotyrosine concentrations in islet lysates, an indicator of oxidative stress, were highly elevated under diabetic conditions but not in islets treated with linagliptin or IL-1Ra. Linagliptin also reduced cytokine secretion and stabilized GLP-1 in islet supernatants. CONCLUSIONS We show that the novel DPP-4 inhibitor linagliptin protected from gluco-, lipo-, and cytokine-toxicity and stabilized active GLP-1 secreted from human islets. This provides a direct GLP-1 mediated protective effect of linagliptin on β-cell function and survival.
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Affiliation(s)
- Payal Shah
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
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117
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Coppieters KT, Amirian N, Pagni PP, Baca Jones C, Wiberg A, Lasch S, Hintermann E, Christen U, von Herrath MG. Functional redundancy of CXCR3/CXCL10 signaling in the recruitment of diabetogenic cytotoxic T lymphocytes to pancreatic islets in a virally induced autoimmune diabetes model. Diabetes 2013; 62:2492-9. [PMID: 23434930 PMCID: PMC3712024 DOI: 10.2337/db12-1370] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cytotoxic T lymphocytes (CTLs) constitute a major effector population in pancreatic islets from patients suffering from type 1 diabetes (T1D) and thus represent attractive targets for intervention. Some studies have suggested that blocking the interaction between the chemokine CXCL10 and its receptor CXCR3 on activated CTLs potently inhibits their recruitment and prevents β-cell death. Since recent studies on human pancreata from T1D patients have indicated that both ligand and receptor are abundantly present, we reevaluated whether their interaction constitutes a pivotal node within the chemokine network associated with T1D. Our present data in a viral mouse model challenge the notion that specific blockade of the CXCL10/CXCR3 chemokine axis halts T1D onset and progression.
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Affiliation(s)
- Ken T. Coppieters
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
- Type 1 Diabetes R&D Center, Novo Nordisk Inc., Seattle, Washington
| | - Natalie Amirian
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Philippe P. Pagni
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Carmen Baca Jones
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Anna Wiberg
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Stanley Lasch
- Pharmazentrum Frankfurt/Center for Drug Research, Development and Safety, Goethe University Hospital, Frankfurt am Main, Germany
| | - Edith Hintermann
- Pharmazentrum Frankfurt/Center for Drug Research, Development and Safety, Goethe University Hospital, Frankfurt am Main, Germany
| | - Urs Christen
- Pharmazentrum Frankfurt/Center for Drug Research, Development and Safety, Goethe University Hospital, Frankfurt am Main, Germany
| | - Matthias G. von Herrath
- Type 1 Diabetes Center, La Jolla Institute for Allergy and Immunology, La Jolla, California
- Type 1 Diabetes R&D Center, Novo Nordisk Inc., Seattle, Washington
- Corresponding author: Matthias G. von Herrath,
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Imai Y, Dobrian AD, Morris MA, Nadler JL. Islet inflammation: a unifying target for diabetes treatment? Trends Endocrinol Metab 2013; 24:351-60. [PMID: 23484621 PMCID: PMC3686848 DOI: 10.1016/j.tem.2013.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 12/12/2022]
Abstract
In the past decade, islet inflammation has emerged as a contributor to the loss of functional β cell mass in both type 1 (T1D) and type 2 diabetes (T2D). Evidence supports the idea that overnutrition and insulin resistance result in the production of proinflammatory mediators by β cells. In addition to compromising β cell function and survival, cytokines may recruit macrophages into islets, thus augmenting inflammation. Limited but intriguing data imply a role of adaptive immune response in islet dysfunction in T2D. Clinical trials have validated anti-inflammatory therapies in T2D, whereas immune therapy for T1D remains challenging. Further research is required to improve our understanding of islet inflammatory pathways and to identify more effective therapeutic targets for T1D and T2D.
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Affiliation(s)
- Yumi Imai
- Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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Burke SJ, Goff MR, Lu D, Proud D, Karlstad MD, Collier JJ. Synergistic Expression of the CXCL10 Gene in Response to IL-1β and IFN-γ Involves NF-κB, Phosphorylation of STAT1 at Tyr701, and Acetylation of Histones H3 and H4. THE JOURNAL OF IMMUNOLOGY 2013; 191:323-36. [DOI: 10.4049/jimmunol.1300344] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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120
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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] [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.
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Affiliation(s)
- B M Tan
- Gene Therapy and Autoimmunity Group, Immunology Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia
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Sahin H, Borkham-Kamphorst E, do O NT, Berres ML, Kaldenbach M, Schmitz P, Weiskirchen R, Liedtke C, Streetz KL, Maedler K, Trautwein C, Wasmuth HE. Proapoptotic effects of the chemokine, CXCL 10 are mediated by the noncognate receptor TLR4 in hepatocytes. Hepatology 2013; 57:797-805. [PMID: 22996399 DOI: 10.1002/hep.26069] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/28/2012] [Indexed: 01/10/2023]
Abstract
UNLABELLED Aberrant expression of the chemokine CXC chemokine ligand (CXCL)10 has been linked to the severity of hepatitis C virus (HCV)-induced liver injury, but the underlying molecular mechanisms remain unclear. In this study, we describe a yet-unknown proapoptotic effect of CXCL10 in hepatocytes, which is not mediated through its cognate chemokine receptor, but the lipopolysaccharide receptor Toll-like receptor 4 (TLR4). To this end, we investigated the link of CXCL10 expression with apoptosis in HCV-infected patients and in murine liver injury models. Mice were treated with CXCL10 or neutralizing antibody to systematically analyze effects on hepatocellular apoptosis in vivo. Direct proapoptotic functions of CXCL10 on different liver cell types were evaluated in detail in vitro. The results showed that CXCL10 expression was positively correlated with liver cell apoptosis in humans and mice. Neutralization of CXCL10 ameliorated concanavalin A-induced tissue injury in vivo, which was strongly associated with reduced liver cell apoptosis. In vitro, CXCL10 mediated the apoptosis of hepatocytes involving TLR4, but not CXC chemokine receptor 3 signaling. Specifically, CXCL10 induced long-term protein kinase B and Jun N-terminal kinase activation, leading to hepatocyte apoptosis by caspase-8, caspase-3, and p21-activated kinase 2 cleavage. Accordingly, systemic application of CXCL10 led to TLR4-induced liver cell apoptosis in vivo. CONCLUSION The results identify CXCL10 and its noncognate receptor, TLR4, as a proapoptotic signaling cascade during liver injury. Antagonism of the CXCL10/TLR4 pathway might be a therapeutic option in liver diseases associated with increased apoptosis.
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Affiliation(s)
- Hacer Sahin
- Medical Department III and University Hospital Aachen, Aachen, Germany
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Shu L, Zien K, Gutjahr G, Oberholzer J, Pattou F, Kerr-Conte J, Maedler K. TCF7L2 promotes beta cell regeneration in human and mouse pancreas. Diabetologia 2012; 55:3296-307. [PMID: 22945304 DOI: 10.1007/s00125-012-2693-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/17/2012] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS Diabetes is characterised by loss and dysfunction of the beta cell. A major goal of diabetes therapy is to promote the formation of new beta cells. Polymorphisms of T cell factor 7-like 2 (TCF7L2) are associated with type 2 diabetes, negatively regulating beta cell survival and function. Here, we provide evidence for a role of TCF7L2 in beta cell proliferation and regeneration. METHODS Pancreatic sections from three mouse models (high-fat diet, exendin-4 and streptozotocin-treated mice) and from healthy individuals and patients with type 2 diabetes were used to investigate the association of beta cell regeneration and TCF7L2 levels. To analyse a direct effect of TCF7L2 on duct cell to beta cell conversion, TCF7L2 was overexpressed in isolated exocrine cells. RESULTS TCF7L2 levels correlated with beta cell compensation during high-fat diet feeding. TCF7L2 was increased together with pancreatic duct cell proliferation and differentiation. Small islet-like cell clusters (ICCs) that contained TCF7L2 originated in the vicinity of the ductal epithelium. In human isolated exocrine tissue, TCF7L2 overexpression induced proliferation of pancreatic duct cells and ICC formation next to duct cells, an effect dependent on the JAK2/STAT3 pathway. CONCLUSIONS/INTERPRETATION The present study demonstrates that TCF7L2 overexpression fosters beta cell regeneration. Our findings imply correlation of TCF7L2 levels and new beta cell formation.
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Affiliation(s)
- L Shu
- Centre for Biomolecular Interactions Bremen, University of Bremen, Leobener Strasse NW2, Bremen, Germany
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Ladefoged M, Buschard K, Hansen AMK. Increased expression of toll-like receptor 4 and inflammatory cytokines, interleukin-6 in particular, in islets from a mouse model of obesity and type 2 diabetes. APMIS 2012; 121:531-8. [PMID: 23134512 DOI: 10.1111/apm.12018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 09/21/2012] [Indexed: 12/25/2022]
Abstract
Toll-like receptor 4 (TLR4) has received much attention in the recent years due to its role in development of insulin resistance in type 2 diabetes mellitus. Its expression is elevated in fat and muscle from insulin-resistant mice. Several cells of the pancreatic islets, including β-cells and resident macrophages, express TLR4. Our hypothesis is that expression of TLR4 and downstream signalling molecules in islets increases during progression of type 2 diabetes, thereby contributing to β-cell damage. We investigated the hypothesis in the db/db mouse. Islets from male db/db (4, 8 and 15 weeks old) and control db/+ (4 and 15 weeks old) mice were examined for mRNA expression of TLR4 and selected cytokines using qPCR. In addition, cytokine secretion from islets was quantified. TLR4 is expressed in islets from lean and obese mice, displaying a 7.4-fold higher level in 15 weeks old db/db relative to age-matched control (p < 0.01). During progression of clinical type 2 diabetes manifested by hyperglycaemia, TLR4 expression increases 5.6-fold in islets from 15 weeks compared with 4 weeks old db/db mice (p < 0.01). Furthermore, both protein and mRNA levels of all cytokines examined increased. In particular, expression of IL-6 increased with 37 fold. Expression of TLR4 in db/db mouse islets increased in parallel with hyperglycaemia. A similar increase in expression and secretion of TNFα, IL-1 and IL-6 was observed. Our results demonstrate that, in addition to its contribution to insulin resistance, TLR4 might also play a role in β-cell dysfunction in type 2 diabetes.
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Dahllöf MS, Christensen DP, Lundh M, Dinarello CA, Mascagni P, Grunnet LG, Mandrup-Poulsen T. The lysine deacetylase inhibitor Givinostat inhibits β-cell IL-1β induced IL-1β transcription and processing. Islets 2012; 4:417-22. [PMID: 23486342 PMCID: PMC3605170 DOI: 10.4161/isl.23541] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
AIMS Pro-inflammatory cytokines and chemokines, in particular IL-1β, IFNγ, and CXCL10, contribute to β-cell failure and loss in DM via IL-1R, IFNγR, and TLR4 signaling. IL-1 signaling deficiency reduces diabetes incidence, islet IL-1β secretion, and hyperglycemia in animal models of diabetes. Further, IL-1R antagonism improves normoglycemia and β-cell function in type 2 diabetic patients. Inhibition of lysine deacetylases (KDACi) counteracts β-cell toxicity induced by the combination of IL-1 and IFNγ and reduces diabetes incidence in non-obese diabetic (NOD) mice. We hypothesized that KDACi breaks an autoinflammatory circuit by differentially preventing β-cell expression of the β-cell toxic inflammatory molecules IL-1β and CXCL10 induced by single cytokines. RESULTS CXCL10 did not induce transcription of IL-1β mRNA. IL-1β induced β-cell IL-1β mRNA and both IL-1β and IFNγ individually induced Cxcl10 mRNA transcription. Givinostat inhibited IL-1β-induced IL-1β mRNA expression in INS-1 and rat islets and IL-1β processing in INS-1 cells. Givinostat also reduced IFNγ induced Cxcl10 transcription in INS-1 cells but not in rat islets, while IL-1β induced Cxcl10 transcription was unaffected in both. MATERIALS AND METHODS INS-1 cells and rat islets of Langerhans were exposed to IL-1β, IFNγ or CXCL10 in the presence or absence of KDACi (givinostat). Cytokine and chemokine mRNA expressions were quantified by real-time qPCR, and IL-1β processing by western blotting of cell lysates. CONCLUSION/INTERPRETATION Inhibition of β-cell IL-1β expression and processing and Cxcl10 transcription contributes to the β-cell protective actions of KDACi. In vitro β-cell destructive effects of CXCL10 are not mediated via IL-1β transcription. The differential proinflammatory actions of KDACs may be attractive novel drug targets in DM.
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Affiliation(s)
- Mattias S. Dahllöf
- Endocrinology Research Section; Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen, Denmark
| | - Dan P. Christensen
- Endocrinology Research Section; Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen, Denmark
| | - Morten Lundh
- Endocrinology Research Section; Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen, Denmark
| | - Charles A. Dinarello
- Italfarmaco; SpA; Cinisello Balsamo, Italy
- Department of Medicine; University of Colorado, Denver; Aurora, CO USA
| | - Paolo Mascagni
- Department of Medicine; University of Colorado, Denver; Aurora, CO USA
| | - Lars G. Grunnet
- Endocrinology Research Section; Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen, Denmark
- Novo Nordisk; Måløv, Denmark
| | - Thomas Mandrup-Poulsen
- Endocrinology Research Section; Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen, Denmark
- Department of Molecular Medicine and Surgery; Karolinska Institutet; Stockholm, Sweden
- Correspondence to: Thomas Mandrup-Poulsen,
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Ahmadi Z, Arababadi MK, Hassanshahi G. CXCL10 Activities, Biological Structure, and Source Along with Its Significant Role Played in Pathophysiology of Type I Diabetes Mellitus. Inflammation 2012; 36:364-71. [DOI: 10.1007/s10753-012-9555-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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126
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Plomgaard P, Halban PA, Bouzakri K. Bimodal impact of skeletal muscle on pancreatic β-cell function in health and disease. Diabetes Obes Metab 2012; 14 Suppl 3:78-84. [PMID: 22928567 DOI: 10.1111/j.1463-1326.2012.01641.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Diabetes is a complex disease that affects many organs directly or indirectly. Type 2 diabetes mellitus is characterized by insulin resistance with a relative deficiency in insulin secretion. It has become apparent that inter-organ communication is of great importance in the pathophysiology of diabetes. Far from being an inert tissue in terms of inter-organ communication, it is now recognized that skeletal muscle can secrete so-called myokines that can impact on the function of distant organs/tissues both favourably and unfavourably. We have proposed that communication between insulin-resistant skeletal muscle and β-cells occurs in diabetes. This is a novel route of communication that we further suggest is modified by the prevailing degree of insulin resistance of skeletal muscle. This review focuses on the various myokines [interleukin-6 (IL-6), tumor necrosis factor-α, CXCL10, follistatin and IL-8] which have been identified either after different types of exercise or in the secretome from control and insulin-resistant human skeletal myotubes. We will also summarize studies on the impact of several myokines on pancreatic β-cell proliferation, survival and function.
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Affiliation(s)
- P Plomgaard
- The Centre of Inflammation and Metabolism, Department of Infectious Diseases, Rigshospitalet, Faculty of Health Sciences, Copenhagen, Denmark
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127
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Dharmadhikari G, Mühle M, Schulthess FT, Laue S, Oberholzer J, Pattou F, Kerr-Conte J, Maedler K. TOSO promotes β-cell proliferation and protects from apoptosis. Mol Metab 2012; 1:70-8. [PMID: 24024120 DOI: 10.1016/j.molmet.2012.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/03/2012] [Accepted: 08/03/2012] [Indexed: 01/09/2023] Open
Abstract
Decreased β-cell mass reflects a shift from quiescence/proliferation into apoptosis, it plays a crucial role in the pathophysiology of diabetes. A major attempt to restore β-cell mass and normoglycemia is to improve β-cell survival. Here we show that switching off the Fas pathway using Fas apoptotic inhibitory protein (Faim/TOSO), which regulates apoptosis upstream of caspase 8, blocked β-cell apoptosis and increased proliferation in human islets. TOSO was clearly expressed in pancreatic β-cells and down-regulated in T2DM. TOSO expression correlated with β-cell turnover; at conditions of improved survival, TOSO was induced. In contrast, TOSO downregulation induced β-cell apoptosis. Although TOSO overexpression resulted in a 3-fold induction of proliferation, proliferating β-cells showed a very limited capacity to undergo multiple rounds of replication. Our data suggest that TOSO is an important regulator of β-cell turnover and switches β-cell apoptosis into proliferation.
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Affiliation(s)
- G Dharmadhikari
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
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128
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Lee JH, Kim HN, Kim KO, Jin WJ, Lee S, Kim HH, Ha H, Lee ZH. CXCL10 promotes osteolytic bone metastasis by enhancing cancer outgrowth and osteoclastogenesis. Cancer Res 2012; 72:3175-86. [PMID: 22562465 DOI: 10.1158/0008-5472.can-12-0481] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Amplification of the chemokines CXCL10 and RANKL has been suggested to promote osteoclast differentiation and osteolytic bone metastasis, but a function for endogenous CXCL10 in these processes is not well established. In this study, we show that endogenous CXCL10 is critical to recruit cancer cells to bone, support osteoclast differentiation and promote for the formation of osteolytic bone metastases. Neutralizing CXCL10 antibody reduced migration of cancer cells expressing the CXCL10 receptor CXCR3, and loss of CXCR3 or CXCL10 decreased bone tumor burden in vivo. Bone colonization augmented host production of CXCL10, which was required for cancer growth and subsequent osteolysis. Direct interactions between cancer cells and macrophages further stimulated CXCL10 production from macrophages. Growth of bone metastases required CXCL10-stimulated adhesion of cancer cells to type I collagen as well as RANKL-mediated osteoclast formation. Together, our findings show that CXCL10 facilitates trafficking of CXCR3-expressing cancer cells to bone, which augments its own production and promotes osteoclastic differentiation. CXCL10 therefore may represent a therapeutic target for osteolytic bone metastasis.
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Affiliation(s)
- Jong-Ho Lee
- Department of Cell and Developmental Biology, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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129
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Is There Inflammatory Synergy in Type II Diabetes Mellitus and Alzheimer's Disease? Int J Alzheimers Dis 2012; 2012:918680. [PMID: 22779027 PMCID: PMC3388453 DOI: 10.1155/2012/918680] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/19/2012] [Indexed: 01/18/2023] Open
Abstract
Metabolic dysregulation, including abnormal glucose utilization and insulin resistance or deficiency, occurs at an early stage of AD independent of type II diabetes mellitus (T2DM). Thus, AD has been considered as type 3 diabetes. T2DM is a risk factor for AD; the coexistence of these two diseases in a society with an increasing mean age is a significant issue. Recently, research has focused on shared molecular mechanisms in these two diseases with the goal of determining whether treating T2DM can lessen the severity of AD. The progress in this field lends strong support to several mechanisms that could affect these two diseases, including insulin resistance and signaling, vascular injuries, inflammation, and the receptor for advanced glycation endproducts and their ligands. In this paper, we focus on inflammation-based mechanisms in both diseases and discuss potential synergism in these mechanisms when these two diseases coexist in the same patient.
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130
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Lipopolysaccharides impair insulin gene expression in isolated islets of Langerhans via Toll-Like Receptor-4 and NF-κB signalling. PLoS One 2012; 7:e36200. [PMID: 22558381 PMCID: PMC3338606 DOI: 10.1371/journal.pone.0036200] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 04/03/2012] [Indexed: 12/12/2022] Open
Abstract
Background Type 2 diabetes is characterized by pancreatic β-cell dysfunction and is associated with low-grade inflammation. Recent observations suggest that the signalling cascade activated by lipopolysaccharides (LPS) binding to Toll-Like Receptor 4 (TLR4) exerts deleterious effects on pancreatic β-cell function; however, the molecular mechanisms of these effects are incompletely understood. In this study, we tested the hypothesis that LPS alters insulin gene expression via TLR4 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in islets. Methodology/Principal Findings A 24-h exposure of isolated human, rat and mouse islets of Langerhans to LPS dose-dependently reduced insulin gene expression. This was associated in mouse and rat islets with decreased mRNA expression of pancreas-duodenum homebox-1 (PDX-1) and mammalian homologue of avian MafA/l-Maf (MafA). Accordingly, LPS exposure also decreased glucose-induced insulin secretion. LPS repression of insulin, PDX-1 and MafA expression, as well as its inhibition of insulin secretion, were not observed in islets from TLR4-deficient mice. LPS inhibition of β-cell gene expression in rat islets was prevented by inhibition of the NF-κB pathway, but not the p38 mitogen-activated protein kinase (p38 MAPK) pathway. Conclusions/Significance Our findings demonstrate that LPS inhibit β-cell gene expression in a TLR4-dependent manner and via NF-κB signaling in pancreatic islets, suggesting a novel mechanism by which the gut microbiota might affect pancreatic β-cell function.
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131
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Saturated fatty acid and TLR signaling link β cell dysfunction and islet inflammation. Cell Metab 2012; 15:518-33. [PMID: 22465073 DOI: 10.1016/j.cmet.2012.01.023] [Citation(s) in RCA: 386] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 12/28/2011] [Accepted: 01/27/2012] [Indexed: 12/19/2022]
Abstract
Consumption of foods high in saturated fatty acids (FAs) as well as elevated levels of circulating free FAs are known to be associated with T2D. Though previous studies showed inflammation is crucially involved in the development of insulin resistance, how inflammation contributes to β cell dysfunction has remained unclear. We report here the saturated FA palmitate induces β cell dysfunction in vivo by activating inflammatory processes within islets. Through a combination of in vivo and in vitro studies, we show β cells respond to palmitate via the TLR4/MyD88 pathway and produce chemokines that recruit CD11b(+)Ly-6C(+) M1-type proinflammatory monocytes/macrophages to the islets. Depletion of M1-type cells protected mice from palmitate-induced β cell dysfunction. Islet inflammation also plays an essential role in β cell dysfunction in T2D mouse models. Collectively, these results demonstrate a clear mechanistic link between β cell dysfunction and inflammation mediated at least in part via the FFA-TLR4/MyD88 pathway.
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132
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Bergholdt R, Brorsson C, Palleja A, Berchtold LA, Fløyel T, Bang-Berthelsen CH, Frederiksen KS, Jensen LJ, Størling J, Pociot F. Identification of novel type 1 diabetes candidate genes by integrating genome-wide association data, protein-protein interactions, and human pancreatic islet gene expression. Diabetes 2012; 61:954-62. [PMID: 22344559 PMCID: PMC3314366 DOI: 10.2337/db11-1263] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Genome-wide association studies (GWAS) have heralded a new era in susceptibility locus discovery in complex diseases. For type 1 diabetes, >40 susceptibility loci have been discovered. However, GWAS do not inevitably lead to identification of the gene or genes in a given locus associated with disease, and they do not typically inform the broader context in which the disease genes operate. Here, we integrated type 1 diabetes GWAS data with protein-protein interactions to construct biological networks of relevance for disease. A total of 17 networks were identified. To prioritize and substantiate these networks, we performed expressional profiling in human pancreatic islets exposed to proinflammatory cytokines. Three networks were significantly enriched for cytokine-regulated genes and, thus, likely to play an important role for type 1 diabetes in pancreatic islets. Eight of the regulated genes (CD83, IFNGR1, IL17RD, TRAF3IP2, IL27RA, PLCG2, MYO1B, and CXCR7) in these networks also harbored single nucleotide polymorphisms nominally associated with type 1 diabetes. Finally, the expression and cytokine regulation of these new candidate genes were confirmed in insulin-secreting INS-1 β-cells. Our results provide novel insight to the mechanisms behind type 1 diabetes pathogenesis and, thus, may provide the basis for the design of novel treatment strategies.
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Affiliation(s)
| | - Caroline Brorsson
- Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark
| | - Albert Palleja
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Tina Fløyel
- Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark
| | | | | | - Lars Juhl Jensen
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Joachim Størling
- Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark
| | - Flemming Pociot
- Glostrup Research Institute, Glostrup University Hospital, Glostrup, Denmark
- Clinical Research Center/University Hospital Malmö, University of Lund, Malmö, Sweden
- Corresponding author: Flemming Pociot,
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133
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Yokoyama S, Hosoi T, Ozawa K. Stearoyl-CoA Desaturase 1 (SCD1) is a key factor mediating diabetes in MyD88-deficient mice. Gene 2012; 497:340-3. [PMID: 22326531 DOI: 10.1016/j.gene.2012.01.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 01/18/2012] [Indexed: 11/18/2022]
Abstract
Saturated fatty acids, acting as ligands for toll-like receptor 4 (TLR4), induce inflammation and mediate the development of insulin resistance. Myeloid differentiation factor 88 (MyD88) is an adaptor protein for TLR4. Previously, we found MyD88-deficient mice fed a high-fat diet (HFD) exhibited a severe diabetic phenotype. Stearoyl-CoA Desaturase 1 (SCD1) is the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids and known as a risk factor of diabetes. In the present study, we found SCD1 was dramatically increased in HFD-fed MyD88-deficient mice liver. This finding showed the novel linkage between MyD88 and SCD1 in the development of diabetes mellitus.
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Affiliation(s)
- Shota Yokoyama
- Department of Pharmacotherapy, Hiroshima University, Hiroshima, Japan.
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134
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Sarkar SA, Lee CE, Victorino F, Nguyen TT, Walters JA, Burrack A, Eberlein J, Hildemann SK, Homann D. Expression and regulation of chemokines in murine and human type 1 diabetes. Diabetes 2012; 61:436-46. [PMID: 22210319 PMCID: PMC3266427 DOI: 10.2337/db11-0853] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
More than one-half of the ~50 human chemokines have been associated with or implicated in the pathogenesis of type 1 diabetes, yet their actual expression patterns in the islet environment of type 1 diabetic patients remain, at present, poorly defined. Here, we have integrated a human islet culture system, murine models of virus-induced and spontaneous type 1 diabetes, and the histopathological examination of pancreata from diabetic organ donors with the goal of providing a foundation for the informed selection of potential therapeutic targets within the chemokine/receptor family. Chemokine (C-C motif) ligand (CCL) 5 (CCL5), CCL8, CCL22, chemokine (C-X-C motif) ligand (CXCL) 9 (CXCL9), CXCL10, and chemokine (C-X3-C motif) ligand (CX3CL) 1 (CX3CL1) were the major chemokines transcribed (in an inducible nitric oxide synthase-dependent but not nuclear factor-κB-dependent fashion) and translated by human islet cells in response to in vitro inflammatory stimuli. CXCL10 was identified as the dominant chemokine expressed in vivo in the islet environment of prediabetic animals and type 1 diabetic patients, whereas CCL5, CCL8, CXCL9, and CX3CL1 proteins were present at lower levels in the islets of both species. Of importance, additional expression of the same chemokines in human acinar tissues emphasizes an underappreciated involvement of the exocrine pancreas in the natural course of type 1 diabetes that will require consideration for additional type 1 diabetes pathogenesis and immune intervention studies.
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Affiliation(s)
- Suparna A. Sarkar
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
| | - Catherine E. Lee
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
| | - Francisco Victorino
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
- Integrated Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, Colorado
| | - Tom T. Nguyen
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
| | - Jay A. Walters
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
| | - Adam Burrack
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
- Integrated Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, Colorado
| | - Jens Eberlein
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
| | | | - Dirk Homann
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado
- Integrated Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, Colorado
- Department of Anesthesiology, University of Colorado Denver, Aurora, Colorado
- Corresponding author: Dirk Homann,
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135
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Boutant M, Ramos OHP, Tourrel-Cuzin C, Movassat J, Ilias A, Vallois D, Planchais J, Pégorier JP, Schuit F, Petit PX, Bossard P, Maedler K, Grapin-Botton A, Vasseur-Cognet M. COUP-TFII controls mouse pancreatic β-cell mass through GLP-1-β-catenin signaling pathways. PLoS One 2012; 7:e30847. [PMID: 22292058 PMCID: PMC3265526 DOI: 10.1371/journal.pone.0030847] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 12/23/2011] [Indexed: 12/25/2022] Open
Abstract
Background The control of the functional pancreatic β-cell mass serves the key homeostatic function of releasing the right amount of insulin to keep blood sugar in the normal range. It is not fully understood though how β-cell mass is determined. Methodology/Principal Findings Conditional chicken ovalbumin upstream promoter transcription factor II (COUP-TFII)-deficient mice were generated and crossed with mice expressing Cre under the control of pancreatic duodenal homeobox 1 (pdx1) gene promoter. Ablation of COUP-TFII in pancreas resulted in glucose intolerance. Beta-cell number was reduced at 1 day and 3 weeks postnatal. Together with a reduced number of insulin-containing cells in the ductal epithelium and normal β-cell proliferation and apoptosis, this suggests decreased β-cell differentiation in the neonatal period. By testing islets isolated from these mice and cultured β-cells with loss and gain of COUP-TFII function, we found that COUP-TFII induces the expression of the β-catenin gene and its target genes such as cyclin D1 and axin 2. Moreover, induction of these genes by glucagon-like peptide 1 (GLP-1) via β-catenin was impaired in absence of COUP-TFII. The expression of two other target genes of GLP-1 signaling, GLP-1R and PDX-1 was significantly lower in mutant islets compared to control islets, possibly contributing to reduced β-cell mass. Finally, we demonstrated that COUP-TFII expression was activated by the Wnt signaling-associated transcription factor TCF7L2 (T-cell factor 7-like 2) in human islets and rat β-cells providing a feedback loop. Conclusions/Significance Our findings show that COUP-TFII is a novel component of the GLP-1 signaling cascade that increases β-cell number during the neonatal period. COUP-TFII is required for GLP-1 activation of the β-catenin-dependent pathway and its expression is under the control of TCF7L2.
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Affiliation(s)
- Marie Boutant
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Oscar Henrique Pereira Ramos
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Cécile Tourrel-Cuzin
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Jamileh Movassat
- Unit of Functional and Adaptative Biology, Laboratory of Biology and Pathology of the Endocrine Pancreas, Paris Diderot University, Paris, France
| | - Anissa Ilias
- Unit of Functional and Adaptative Biology, Laboratory of Biology and Pathology of the Endocrine Pancreas, Paris Diderot University, Paris, France
| | - David Vallois
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Julien Planchais
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Jean-Paul Pégorier
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Frans Schuit
- Department of Molecular Cellular Biology, Leuven, Belgium
| | - Patrice X. Petit
- Centre national de la recherche scientifique (CNRS), Cochin Institute, Paris, France
| | - Pascale Bossard
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, Germany
| | | | - Mireille Vasseur-Cognet
- Institute national del santé et de la recherché medicale(INSERM), Department of Endocrinology, Metabolism and Cancer, Cochin Institute, Paris-France
- Centre national de la recherche scientifique (CNRS), Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, France
- * E-mail:
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136
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Ranta F, Leveringhaus J, Theilig D, Schulz-Raffelt G, Hennige AM, Hildebrand DG, Handrick R, Jendrossek V, Bosch F, Schulze-Osthoff K, Häring HU, Ullrich S. Protein kinase C delta (PKCδ) affects proliferation of insulin-secreting cells by promoting nuclear extrusion of the cell cycle inhibitor p21Cip1/WAF1. PLoS One 2011; 6:e28828. [PMID: 22216119 PMCID: PMC3246440 DOI: 10.1371/journal.pone.0028828] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 11/15/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND High fat diet-induced hyperglycemia and palmitate-stimulated apoptosis was prevented by specific inhibition of protein kinase C delta (PKCδ) in β-cells. To understand the role of PKCδ in more detail the impact of changes in PKCδ activity on proliferation and survival of insulin-secreting cells was analyzed under stress-free conditions. METHODOLOGY AND PRINCIPAL FINDINGS Using genetic and pharmacological approaches, the effect of reduced and increased PKCδ activity on proliferation, apoptosis and cell cycle regulation of insulin secreting cells was examined. Proteins were analyzed by Western blotting and by confocal laser scanning microscopy. Increased expression of wild type PKCδ (PKCδWT) significantly stimulated proliferation of INS-1E cells with concomitant reduced expression and cytosolic retraction of the cell cycle inhibitor p21(Cip1/WAF1). This nuclear extrusion was mediated by PKCδ-dependent phosphorylation of p21(Cip1/WAF1) at Ser146. In kinase dead PKCδ (PKCδKN) overexpressing cells and after inhibition of endogenous PKCδ activity by rottlerin or RNA interference phosphorylation of p21(Cip1/WAF1) was reduced, which favored its nuclear accumulation and apoptotic cell death of INS-1E cells. Human and mouse islet cells express p21(Cip1/WAF1) with strong nuclear accumulation, while in islet cells of PKCδWT transgenic mice the inhibitor resides cytosolic. CONCLUSIONS AND SIGNIFICANCE These observations disclose PKCδ as negative regulator of p21(Cip1/WAF1), which facilitates proliferation of insulin secreting cells under stress-free conditions and suggest that additional stress-induced changes push PKCδ into its known pro-apoptotic role.
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Affiliation(s)
- Felicia Ranta
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Johannes Leveringhaus
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Dorothea Theilig
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Gabriele Schulz-Raffelt
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Anita M. Hennige
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Dominic G. Hildebrand
- Interfaculty Institute for Biochemistry (IFIB), University of Tübingen, Tübingen, Germany
| | - René Handrick
- Institute for Pharmaceutical Biotechnology, Biberach University of Applied Sciences, Biberach, Germany
| | | | - Fatima Bosch
- Center of Animal Biotechnology and Gene Therapy, Universita Autònoma Barcelona, Bellaterra and CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Klaus Schulze-Osthoff
- Interfaculty Institute for Biochemistry (IFIB), University of Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Susanne Ullrich
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
- * E-mail:
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137
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Yellin M, Paliienko I, Balanescu A, Ter-Vartanian S, Tseluyko V, Xu LA, Tao X, Cardarelli PM, Leblanc H, Nichol G, Ancuta C, Chirieac R, Luo A. A phase II, randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of MDX-1100, a fully human anti-CXCL10 monoclonal antibody, in combination with methotrexate in patients with rheumatoid arthritis. ACTA ACUST UNITED AC 2011; 64:1730-9. [PMID: 22147649 DOI: 10.1002/art.34330] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE CXCL10 (also known as interferon-γ-inducible 10-kd protein [IP-10]) is a chemokine that potentially plays a role in the immunopathogenesis of rheumatoid arthritis (RA). We undertook this phase II study to evaluate the efficacy and safety of MDX-1100, a fully human, anti-CXCL10 (anti-IP-10) monoclonal antibody, in RA patients whose disease responded inadequately to methotrexate (MTX). METHODS Patients with active RA receiving stable doses of MTX (10-25 mg weekly) were randomized to receive intravenous doses of 10 mg/kg MDX-1100 (n = 35) or placebo (n = 35) every other week. The primary end point was the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) on day 85, and patients were followed up for safety to day 141. RESULTS The ACR20 response rate was significantly higher among MDX-1100-treated patients than among placebo-treated patients (54% versus 17%; P = 0.0024). Statistically significant differences in the ACR20 response rate between treatments were observed starting on day 43 (P < 0.05). The ACR50 and ACR70 response rates on day 85 did not differ between the groups. Overall, 51.4% of MDX-1100-treated patients and 30.3% of placebo-treated patients experienced at least 1 adverse event (AE). No study drug-related serious AEs were reported. CONCLUSION MDX-1100 was well tolerated and demonstrated clinical efficacy in RA patients whose disease responded inadequately to MTX. This is the first study to demonstrate clinical efficacy of a chemokine inhibitor in RA and supports the notion of a potential role of IP-10 in the immunopathogenesis of RA.
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138
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Weile C, Josefsen K, Buschard K. Glucose activation of islets of Langerhans up-regulates Toll-like receptor 5: possible mechanism of protection. Clin Exp Immunol 2011; 166:251-7. [PMID: 21985371 DOI: 10.1111/j.1365-2249.2011.04457.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Toll-like receptors are pattern-recognition receptors of the innate immune system that are activated during viral, bacterial or other infections, as well as during disease progression of type 1 and type 2 diabetes. Toll-like receptor 5 (TLR-5) specifically recognizes bacterial infection through binding of flagellin from pathogenic bacteria such as Salmonella and Listeria species. We have found that the expression of TLR5 is up-regulated by glucose activation of isolated islets of Langerhans, in contrast to other investigated TLRs (TLR-2, -3, -4, -6 and -9. Stimulation of islets with 10 mm glucose increased the levels of TLR5 mRNA 10-fold (P=0·03) and the TLR-5 protein levels twofold (P=0·04). Furthermore, the protein level of downstream signalling molecule myeloid differentiation primary response gene 88 (MyD88) increased 1·6-fold (P=0·01). Activation of TLR-5 in islets lead to a marked reduction of both stimulated and basal secretion of insulin, as well as an increase in production of nitric oxide, proinflammatory cytokines, anti-inflammatory heat-shock protein and major histocompatibility complex (MHC) class I transporter. We observe no effects of TLR-5 activation on islet survival. We suggest that this regulation by TLR-5 might be beneficial during serious infection such as sepsis by limiting the activity of beta cells during peaks of insulin demand to counteract beta cell damage.
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Affiliation(s)
- C Weile
- The Bartholin Institute, Rigshospitalet, Copenhagen, Denmark.
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139
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Abstract
Organisms are perpetually facing noxious insults but exhibit surprising diverse reaction patterns. Depending on the strength, frequency and quality of the stress stimuli biological systems may react with increased vitality, future stress resistance or with injury and degeneration. Whereas a multitude of such specific stress responses has been observed in diverse biological systems the underlying molecular mechanisms are mainly unknown. These knowledge restrictions urge the exploration of specific molecular signaling reactions controlling the ambivalent responses of cells and organisms to noxious effects. The adaptive responses of signaling networks to defined stress stimuli need to be investigated in a time-and dose-resolved manner in cellular and organismic models. Anticipated results are expected to significantly advance the understanding of the molecular signatures of stress responses and may also promote ongoing efforts for the effective use of the organism's preventive and regenerative potentials in modern medicine.
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Affiliation(s)
- Reinhard Wetzker
- Institute of Molecular Cell Biology, CMB-Center for Molecular Biomedicine, Jena University Hospital, Germany
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140
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Manolakis AC, Kapsoritakis AN, Tiaka EK, Sidiropoulos A, Gerovassili A, Satra M, Vamvakopoulou D, Tsiopoulos F, Papanas N, Skoularigis I, Potamianos SP, Vamvakopoulos N. TLR4 gene polymorphisms: evidence for protection against type 2 diabetes but not for diabetes-associated ischaemic heart disease. Eur J Endocrinol 2011; 165:261-7. [PMID: 21628510 DOI: 10.1530/eje-11-0280] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Several factors either predisposing or protecting from the onset of diabetes mellitus type 2 (DM2) have been proposed. Two specific polymorphisms of toll-like receptor 4 (TLR4; Asp299Gly and Thr399Ile) have recently been identified either as candidate protector genes against DM2 and associated neuropathy or risk alleles for the manifestation of diabetic retinopathy. The impact of these alleles on the risk for ischaemic heart disease (IHD) is controversial while their role in diabetes-associated IHD has never been studied. DESIGN AND METHODS In order to clarify the potential impact of TLR4 polymorphisms on the predisposition for DM2 as well as on diabetes-related IHD vulnerability, the distribution of the mutant TLR4 Asp299Gly and Thr399Ile alleles in 286 DM2 patients and 413 non-DM2 controls with or without IHD, was examined. RESULTS Mutant alleles were predominantly detected in 79/413 non-diabetic individuals versus 15/286 DM2 patients (P<0.0001). The rates of positivity for mutant alleles were similar among diabetic patients with or without IHD (7/142 vs 8/144, P>0.1), whereas they proved different among non-diabetic individuals with or without IHD (39/145 vs 40/268, P=0.004). Following multivariate analysis, the difference between diabetic and non-diabetic subjects, with regard to TLR4 mutations alone, remained significant (P=0.04). CONCLUSIONS Mutant TLR4 alleles confer protection against DM2. However, their presence does not seem to play any role, protective or aggravating, in the manifestation of IHD either in diabetic or in non-diabetic individuals.
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Affiliation(s)
- A C Manolakis
- Departments of Gastroenterology Molecular Biology and Genetics, School of Medicine, University of Thessaly, 41110 Mezourlo, Larissa, Greece
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141
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Itoh M, Suganami T, Hachiya R, Ogawa Y. Adipose tissue remodeling as homeostatic inflammation. Int J Inflam 2011; 2011:720926. [PMID: 21755030 PMCID: PMC3132651 DOI: 10.4061/2011/720926] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 04/27/2011] [Indexed: 12/12/2022] Open
Abstract
Evidence has accumulated indicating that obesity is associated with a state of chronic, low-grade inflammation. Obese adipose tissue is characterized by dynamic changes in cellular composition and function, which may be referred to as “adipose tissue remodeling”. Among stromal cells in the adipose tissue, infiltrated macrophages play an important role in adipose tissue inflammation and systemic insulin resistance. We have demonstrated that a paracrine loop involving saturated fatty acids and tumor necrosis factor-α derived from adipocytes and macrophages, respectively, aggravates obesity-induced adipose tissue inflammation. Notably, saturated fatty acids, which are released from hypertrophied adipocytes via the macrophage-induced lipolysis, serve as a naturally occurring ligand for Toll-like receptor 4 complex, thereby activating macrophages. Such a sustained interaction between endogenous ligands derived from parenchymal cells and pathogen sensors expressed in stromal immune cells should lead to chronic inflammatory responses ranging from the basal homeostatic state to diseased tissue remodeling, which may be referred to as “homeostatic inflammation”. We, therefore, postulate that adipose tissue remodeling may represent a prototypic example of homeostatic inflammation. Understanding the molecular mechanism underlying homeostatic inflammation may lead to the identification of novel therapeutic strategies to prevent or treat obesity-related complications.
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Affiliation(s)
- Michiko Itoh
- Department of Molecular Medicine and Metabolism, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
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142
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Skog O, Korsgren O, Frisk G. Modulation of innate immunity in human pancreatic islets infected with enterovirus in vitro. J Med Virol 2011; 83:658-64. [PMID: 21328381 DOI: 10.1002/jmv.21924] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Present knowledge of innate immunity in infected cells relies on studies of cell lines and animal models. In this study, primary human pancreatic islets of Langerhans were used to study virus-host interactions in a model of the possible induction of type 1 diabetes by enterovirus (EV). Human islets were infected with a strain of EV isolated at onset of type 1 diabetes, or exposed to synthetic dsRNA (poly(I:C)), used commonly to mimic viral infection. Induction of innate immunity and the effect of the female sex hormone 17β-estradiol, known to have cell-protective effects, on islet chemokine secretion were investigated. 17β-Estradiol reduced EV-but not poly(I:C)-induced IP-10/CXCL10 secretion from human islets, suggesting that separate signaling pathways of the innate immune response are triggered by EV and poly(I:C), respectively. Infection with EV increased the gene-expression of toll-like receptor 3, interferon-β, and the intracellular helicase MDA5, involved in antiviral innate immunity, multi-fold over time, whereas poly(I:C) increased the expression of these genes transiently. The induced expression pattern was similar in all donors, but the expression levels varied greatly. Pre-exposure to poly(I:C) blocked viral replication in islets from 56% of the donors. These data provide insight on the innate immune responses induced by EV in human islets, and show that this can be modulated by 17β-estradiol, and suggest an important difference between virus- and poly(I:C)-induced signaling.
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Affiliation(s)
- Oskar Skog
- Division of Clinical Immunology, Department of Oncology, Radiology, and Clinical Immunology, The Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
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143
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Nicotinic acid inhibits glucose-stimulated insulin secretion via the G protein-coupled receptor PUMA-G in murine islet β cells. Pancreas 2011; 40:615-21. [PMID: 21441844 DOI: 10.1097/mpa.0b013e31820b4b23] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Chronic administration of nicotinic acid (NA), a potent antilipidemic compound, aggravates glycemic control in diabetic patients. It is not known if NA has direct effects on islet β cells. METHODS Real-time reverse transcriptase-polymerase chain reaction, in situ hybridization, and immunofluorescence techniques were used to examine the expression of NA receptor PUMA-G, a member of the G protein-coupled receptor (G-PCR) family, in murine islet β cells. Calcium transient was measured using confocal microscopy, whereas the intracellular cyclic adenosine monophosphate and glucose-stimulated insulin secretion (GSIS) from isolated islets were determined by the enzyme-linked immunosorbent assay. RESULTS High levels of PUMA-G transcripts and protein were detected in all β cells, and about 40% of α cells. PUMA-G transcripts increased more than 3-fold in islets incubated with interferon γ. Cyclic adenosine monophosphate accumulation, induced by IBMX/forskolin, was inhibited by NA; however, the inhibition was completely abolished by pretreatment of the culture with pertussis toxin. No calcium transient was detected in islet cells in the presence of NA. Static incubation of islets with NA led to an approximately 30% reduction of GSIS. CONCLUSIONS The results indicated that PUMA-G stimulation by NA in islet β cells inhibited GSIS likely via activation of the Gi signaling pathway.
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144
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Bouzakri K, Plomgaard P, Berney T, Donath MY, Pedersen BK, Halban PA. Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle. Diabetes 2011; 60:1111-21. [PMID: 21378173 PMCID: PMC3064085 DOI: 10.2337/db10-1178] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells. RESEARCH DESIGN AND METHODS Human skeletal muscle cells were cultured for up to 24 h with tumor necrosis factor (TNF)-α to induce insulin resistance, and mRNA expression for cytokines was analyzed and compared with controls (without TNF-α). Conditioned media were collected and candidate cytokines were measured by antibody array. Human and rat primary β-cells were used to explore the impact of exposure to conditioned media for 24 h on apoptosis, proliferation, short-term insulin secretion, and key signaling protein phosphorylation and expression. RESULTS Human myotubes express and release a different panel of myokines depending on their insulin sensitivity, with each panel exerting differential effects on β-cells. Conditioned medium from control myotubes increased proliferation and glucose-stimulated insulin secretion (GSIS) from primary β-cells, whereas conditioned medium from TNF-α-treated insulin-resistant myotubes (TMs) exerted detrimental effects that were either independent (increased apoptosis and decreased proliferation) or dependent on the presence of TNF-α in TM (blunted GSIS). Knockdown of β-cell mitogen-activated protein 4 kinase 4 prevented these effects. Glucagon-like peptide 1 protected β-cells against decreased proliferation and apoptosis evoked by TMs, while interleukin-1 receptor antagonist only prevented the latter. CONCLUSIONS Taken together, these data suggest a possible new route of communication between skeletal muscle and β-cells that is modulated by insulin resistance and could contribute to normal β-cell functional mass in healthy subjects, as well as the decrease seen in type 2 diabetes.
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Affiliation(s)
- Karim Bouzakri
- Department of Genetic Medicine and Development, University Medical Center, University of Geneva, Geneva, Switzerland.
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145
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Ardestani A, Sauter NS, Paroni F, Dharmadhikari G, Cho JH, Lupi R, Marchetti P, Oberholzer J, Conte JK, Maedler K. Neutralizing interleukin-1beta (IL-1beta) induces beta-cell survival by maintaining PDX1 protein nuclear localization. J Biol Chem 2011; 286:17144-55. [PMID: 21393239 DOI: 10.1074/jbc.m110.210526] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The transcription factor PDX1 plays a critical role during β-cell development and in glucose-induced insulin gene transcription in adult β-cells. Acute glucose exposure leads to translocalization of PDX1 to the nucleoplasm, whereas under conditions of oxidative stress, PDX1 shuttles from the nucleus to the cytosol. Here we show that cytosolic PDX1 expression correlated with β-cell failure in diabetes. In isolated islets from patients with type 2 diabetes and from diabetic mice, we found opposite regulation of insulin and PDX1 mRNA; insulin was decreased in diabetes, but PDX1 was increased. This suggests that elevated PDX1 mRNA levels may be insufficient to regulate insulin. In diabetic islets, PDX1 protein was localized in the cytosol, whereas in non-diabetic controls, PDX1 was in the nucleus. In contrast, overexpression of either IL-1 receptor antagonist or shuttling-deficient PDX1 restored β-cell survival and function and PDX1 nuclear localization. Our results show that nuclear localization of PDX1 is essential for a functional β-cell and provides a novel mechanism of the protective effect of IL-1 receptor antagonist on β-cell survival and function.
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Affiliation(s)
- Amin Ardestani
- Islet Biology Laboratory, Centre for Biomolecular Interactions Bremen 28355, University of Bremen, Leobener Strasse NW2, Rm. B2080, 28359 Bremen, Germany
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146
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Le Bacquer O, Shu L, Marchand M, Neve B, Paroni F, Kerr Conte J, Pattou F, Froguel P, Maedler K. TCF7L2 splice variants have distinct effects on beta-cell turnover and function. Hum Mol Genet 2011; 20:1906-15. [PMID: 21357677 DOI: 10.1093/hmg/ddr072] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Type 2 diabetes manifests when the β-cell fails to secrete sufficient amounts of insulin to maintain normoglycemia and undergoes apoptosis. The disease progression results from an interplay of environmental factors and genetic predisposition. Polymorphisms in T-cell factor 7-like 2 (TCF7L2) strongly correlate with type 2 diabetes mellitus (T2DM). While TCF7L2 mRNA is upregulated in islets in diabetes, protein levels are downregulated. The loss of TCF7L2 induces impaired function and apoptosis. By analyzing human isolated islets, we provide three explanations for this opposite regulation and the mechanisms of TCF7L2 on β-cell function and survival. (i) We found TCF7L2 transcripts in the human β-cell, which had opposite effects on β-cell survival, function and Wnt signaling activation. While TCF7L2 clone B1, which lacks exons 13, 14, 15 and 16 induced β-cell apoptosis, impaired function and inhibited glucagon-like peptide 1 response and downstream targets of Wnt signaling, clones B3 and B7 which both contain exon 13, improved β-cell survival and function and activated Wnt signaling. (ii) TCF7L2 mRNA is extremely unstable and is rapidly degraded under pro-diabetic conditions and (iii) TCF7L2 depletion in islets induced activation of glycogen synthase kinase 3-β, but this was independent of endoplasmic reticulum stress. We demonstrated function-specific transcripts of TCF7L2, which possessed distinct physiological and pathophysiological effects on the β-cell. The presence of deleterious TCF7L2 splice variants may be a mechanism of β-cell failure in T2DM.
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Affiliation(s)
- Olivier Le Bacquer
- CNRS UMR 8199, Institut de Biologie de Lille, Univ Lille Nord de France, France
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147
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Antonelli A, Ferrari SM, Fallahi P, Piaggi S, Paolicchi A, Franceschini SS, Salvi M, Ferrannini E. Cytokines (interferon-γ and tumor necrosis factor-α)-induced nuclear factor-κB activation and chemokine (C-X-C motif) ligand 10 release in Graves disease and ophthalmopathy are modulated by pioglitazone. Metabolism 2011; 60:277-83. [PMID: 20206950 DOI: 10.1016/j.metabol.2010.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 01/29/2010] [Accepted: 02/01/2010] [Indexed: 11/15/2022]
Abstract
Until now, the following are not known: (1) the mechanisms underlying the induction of chemokine (C-X-C motif) ligand 10 (CXCL10) secretion by cytokines in thyrocytes; (2) if pioglitazone is able, like rosiglitazone, to inhibit the interferon (IFN)-γ-induced chemokine expression in Graves disease (GD) or ophthalmopathy (GO); and (3) the mechanisms underlying the inhibition by thiazolidinediones of the cytokines-induced CXCL10 release in thyrocytes. The aims of this study were (1) to study the mechanisms underlying the induction of CXCL10 secretion by cytokines in GD thyrocytes; (2) to test the effect of pioglitazone on IFNγ-inducible CXCL10 secretion in primary thyrocytes, orbital fibroblasts, and preadipocytes from GD and GO patients; and (3) to evaluate the mechanism of action of thiazolidinediones on nuclear factor (NF)-κB activation. The results of the study (1) demonstrate that IFNγ + TNFα enhanced the DNA binding activity of NF-κB in GD thyrocytes, in association with the release of CXCL10; (2) show that pioglitazone exerts a dose-dependent inhibition on IFNγ + TNFα-induced CXCL10 secretion in thyrocytes, orbital fibroblasts, and preadipocytes, similar to the effect observed with rosiglitazone; and (3) demonstrate that thiazolidinediones (pioglitazone and rosiglitazone) act by reducing the IFNγ + TNFα activation of NF-κB in Graves thyrocytes. To the best of our knowledge, this is the first study showing that cytokines are able to activate NF-κB in Graves thyrocytes and a parallel inhibitory effect of pioglitazone both on CXCL10 chemokine secretion and NF-κB activation. Future studies will be needed to verify if new targeted peroxisome proliferator-activated receptor-γ activators may be able to exert the anti-inflammatory effects without the risk of expanding retrobulbar fat mass.
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Affiliation(s)
- Alessandro Antonelli
- Department of Internal Medicine, University of Pisa-School of Medicine, I-56100 Pisa, Italy.
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148
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Oikawa Y, Shimada A, Yamada Y, Okubo Y, Katsuki T, Shigihara T, Miyazaki JI, Narumi S, Itoh H. CXC chemokine ligand 10 DNA vaccination plus Complete Freund's Adjuvant reverses hyperglycemia in non-obese diabetic mice. Rev Diabet Stud 2010; 7:209-24. [PMID: 21409313 DOI: 10.1900/rds.2010.7.209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE Complete Freund's Adjuvant (CFA) is known to arrest autoimmune diabetes development in non-obese diabetic (NOD) mice. However, CFA alone cannot induce effective remission in diabetic NOD mice. Previously, we reported that anti-CXC chemokine ligand 10 (CXCL10) antibody can promote beta-cell proliferation in NOD mice. In the present study, we aimed to examine whether anti-CXCL10 plus CFA treatment can effectively reverse autoimmune diabetes development. METHODS Systemic supply of anti-CXCL10 antibody by CXCL10 DNA vaccination in combination with CFA injection was performed in new-onset diabetic NOD mice. Remission rate of diabetes, histological characteristics of residual insulitis lesions, residual beta-cell mass, and regulatory T cell population in local pancreas were examined. RESULTS A high frequency of diabetes reversal was observed after combination treatment with anti-CXCL10 plus CFA. In mice showing diabetes reversal, residual beta-cell mass was significantly increased, and some beta-cells were in a proliferative state. Although systemic cytokine profiles were unaffected, the frequency of "hybrid regulatory T cells", i.e. regulatory T cells expressing CXCR3, was significantly increased in local pancreatic lesions. This was possibly associated with the regulation of anti-islet autoimmunity. CONCLUSIONS Anti-CXCL10 plus appropriate immune adjuvant therapy arrested, and reversed, type 1 diabetes development.
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Affiliation(s)
- Yoichi Oikawa
- Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
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149
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Pugazhenthi U, Velmurugan K, Tran A, Mahaffey G, Pugazhenthi S. Anti-inflammatory action of exendin-4 in human islets is enhanced by phosphodiesterase inhibitors: potential therapeutic benefits in diabetic patients. Diabetologia 2010; 53:2357-68. [PMID: 20635178 DOI: 10.1007/s00125-010-1849-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 06/14/2010] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Exendin-4, a glucagon-like peptide-1 (GLP-1) analogue, is reported to have modest anti-inflammatory effects in addition to that of improving beta cell survival. We therefore sought to determine whether exendin-4 decreases expression of the gene encoding chemokine (C-X-C motif) ligand (CXCL)10, which plays a role in initiating insulitis in type 1 diabetes. METHODS The expression of CXCL10 in human islets was determined at the mRNA level by real-time RT-PCR analysis and at the protein level by western blotting. The level of CXCL10 in culture medium was measured by ELISA. Pathway-specific gene expression profiling was carried out to determine the expression of a panel of genes encoding chemokines and cytokines in human islets exposed to cytokines. RESULTS IFN-γ induced expression of CXCL10 through activation of signal transducer and activator of transcription-1 (STAT-1). A combination of cytokines (IL-1β, TNF-α and IFN-γ) showed strong synergy in the induction of numerous chemokines and cytokines through nuclear factor kappa B and STAT-1. Exendin-4 suppressed basal expression of several inflammatory mediators. In combination with phosphodiesterase inhibitors, exendin-4 also decreased IFN-γ-induced CXCL10 expression in human islets and in MIN6 cells (a mouse beta cell line), and its secretion into the culture medium. Exendin-4 action was mimicked by forskolin, an activator of adenylyl cyclase, and by dibutyryl cyclic AMP. Protein kinase A was not involved in mediating exendin-4 action on CXCL10. The mechanism of exendin-4's anti-inflammatory action involved decreases in STAT-1 levels. CONCLUSIONS/INTERPRETATION These findings suggest that the GLP-1-cyclic AMP pathway decreases islet inflammation in addition to its known effects on beta cell survival.
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Affiliation(s)
- U Pugazhenthi
- Department of Medicine, University of Colorado Denver, Mail Stop 8106, 12801 E 17th Ave, Aurora, CO 80045, USA
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150
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Myeloid differentiation factor 88 (MyD88)-deficiency increases risk of diabetes in mice. PLoS One 2010; 5. [PMID: 20824098 PMCID: PMC2932727 DOI: 10.1371/journal.pone.0012537] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 08/05/2010] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Multiple lines of evidence suggest innate immune response pathways to be involved in the development of obesity-associated diabetes although the molecular mechanism underling the disease is unknown. Recent observations suggest that saturated fatty acids can act as a ligand for toll-like receptor (TLR) 4, which is thought to mediate obesity-associated insulin resistance. Myeloid differentiation factor 88 (MyD88) is an adapter protein for TLR/IL-1 receptor signaling, which is involved in the activation of inflammatory pathways. To evaluate molecular mechanisms linking obesity-associated diabetes down-stream of TLR4, we investigated physiological role of MyD88 in high-fat diet (HFD)-induced obesity. METHODOLOGY/PRINCIPAL FINDINGS In the present study, we found MyD88-deficient mice fed a HFD had increased circulating levels of insulin, leptin and cholesterol, as well as liver dysfunction (increased induction of ALT levels, increased activation of JNK and cleavage of PARP), which were linked to the onset of severe diabetes. On the other hand, TNF-alpha would not be involved in HFD-induced diabetes in MyD88-deficient mice, because TNF-alpha level was attenuated in MyD88-deficient mice fed with HFD. CONCLUSIONS/SIGNIFICANCE The present finding of an unexpected role for MyD88 in preventing diabetes may provide a potential novel target/strategy for treating metabolic syndrome.
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