title: Integration of pro-inflammatory cytokines, 12-lipoxygenase and NOX-1 in pancreatic islet beta cell dysfunction.
abstract: Elevated cellular reactive species, which can be produced by diabetic serum conditions such as elevated inflammatory cytokines, lipotoxicity or glucotoxicity contribute to islet beta cell dysfunction and cell death. Cellular pathways that result in beta cell oxidative stress are poorly resolved. In this study, stimulation of human donor islets, primary mouse islets or homogeneous beta cell lines with a cocktail of inflammatory cytokines (TNFα, IL-1β, and INFγ) significantly induced NADPH oxidase-1 (NOX-1) gene expression (p<0.05). This pro-inflammatory cytokine cocktail concomitantly induced loss of islet glucose stimulated insulin response (p<0.05), elevated expression of MCP-1 (p<0.01), increased cellular reactive oxygen species (ROS) and induced cell death. Inhibitors of NADPH oxidase, apocynin and diphenyleneiodonium, and a dual selective NOX1/4 inhibitor, blocked ROS generation (p<0.01) and induction of MCP-1 (p<0.05) by pro-inflammatory cytokines in beta cells. It has previously been reported that pro-inflammatory cytokine stimulation induces 12-lipoxygenase (12-LO) expression in human islets. 12-Hydroxyeicosatetraenoic acid (12-HETE), a product of 12-LO activity, stimulated NOX-1 expression in human islets (p<0.05). A novel selective inhibitor of 12-LO blocked induction of NOX-1, production of ROS and pro-caspase 3 cleavage by pro-inflammatory cytokines in INS-1 beta cells (p<0.01). Inhibition was not seen with a structurally related but inactive analog. Importantly, islets from human type 2 diabetic donors have an elevated expression of NOX-1 (p<0.05). This study describes an integrated pathway in beta cells that links beta cell dysfunction induced by pro-inflammatory cytokines with 12-lipoxygenase and NADPH oxidase (NOX-1) activation. Inhibitors of this pathway may provide a new therapeutic strategy to preserve beta cell mass in diabetes.
authors.affiliation: Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, VA 23501, United States.
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Weaver
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Holman
authors.forename: Yumi
authors.initials: Y
authors.lastname: Imai
authors.forename: Ajit
authors.initials: A
authors.lastname: Jadhav
authors.forename: Victor
authors.initials: V
authors.lastname: Kenyon
authors.forename: David J
authors.initials: DJ
authors.lastname: Maloney
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Nadler
authors.forename: Ganesha
authors.initials: G
authors.lastname: Rai
authors.forename: Anton
authors.initials: A
authors.lastname: Simeonov
authors.forename: David A
authors.initials: DA
authors.lastname: Taylor-Fishwick
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D018932:Chemokine CCL2 / Q000096:biosynthesis; D003920:Diabetes Mellitus / Q000378:metabolism / Q000473:pathology; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000473:pathology; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000074624:NADPH Oxidase 1; D009861:Onium Compounds / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000098:Acetophenones; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D053583:Interleukin-1beta; D009861:Onium Compounds; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; C007517:diphenyleneiodonium; C026221:12-hydroxy-5,8,10,14,17-eicospentaenoic acid; D007371:Interferon-gamma; D015118:Eicosapentaenoic Acid; C056165:acetovanillone; D001092:Arachidonate 12-Lipoxygenase; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; C000614711:NOX1 protein, mouse; D053148:Caspase 3