Oxidative Stress and DiabetesJian LiBeijing Institute of Geriatrics Ministry of HealthRedox “rheostat“ in vascular cells Reactive oxygen species (= ROS)O2O2- H2 O2acidic pH, Superoxyde Dismutase (SOD)NADPH oxidaseSuperoxide anionHydrogen peroxideProposed functions of ROSkilling of microorganismsDNA damagecancerogenesisageing cell deathNO inactivation and peroxynitrite generationregulation of cell growth and differentiationregulation of cell functionoxygen sensing activation of redox-sensitive transcription factorsactivation of redox-sensitive second messenger systemsWhere and why are reactive oxygen species generated? Mitochondria by-product of the oxidative metabolism Phagocyte NADPH oxidase microbial killing NADPH oxidase of non-phagocytic cells cell growth, cell signalingNOX-type NADPH oxidases as superoxide-producing enzymesFeFeoutsideinsideIVIIVIIIIIVNH2HHHH HHNADPHFADCOOHH115O2O2-e-The NOX family of NADPH oxidasesReview: Lambeth et al. Novel homologs of gp91phox.Trends in Biochemical Sciences 25: 459-461, 2000.gp91phox homologyEF-handsNox1 colon Nox2 phagocytes Nox3 inner ear Nox4 kidney Nox5 testis and lymphoid tissuesO2O2-NADPHe-Structure of the NAD(P)H Structure of the NAD(P)H oxidaseoxidaseCharacteristics of neutrophil and vascular NAD(P)H oxidaseNAD(P)H Oxidase ActivationAdenovirus-induced overexpression of PKC-2 causes the membranous translocation of p47phox and p67phoxA model illustrating how increased ROS production in accumulated fat contributes to metabolic syndromeMechanism for increased ROS production induced by diabetes and insulin-resistant stateLinking various risk factors to ROS generation in the development of IDDMInitiation and amplification of the immune/inflammatory response by ROS-induced NF B activation in -cell death Schematic illustration of ROS-mediated NFB activationElevated glucose and FFA levels contribute to the pathophysiology of diabetes via the generation of ROSThe role of serine kinase activation in oxidative stress induced insulin resistanceVascular effects of reactive oxygen species (ROS)Modulation of cellular function by ROS in cardiovascular diseasesPotential role of NADPH oxidase in the pathogenesis of diabetic nephropathyEffect of high glucose level and PMA on ROS production in aortic smooth muscle cells (A) and endothelial cells (B)Effect of diphenylene iodonium on high glucose or PMA-induced increase in ROS production in aortic smooth muscle cells (A) or endothelial cells (B)PKC- inhibition suppresses diabetes-induced O2- productionRedox-dependent signaling pathways by Ang II in vascular smooth muscle cellsDetection of intracellular production of reactive oxygen species.A. Fluorescence microscopy visualization of ROS production in pericytes and smooth muscle cells. a: control;b: cells cultured in 25 mM glucose and AGE-Lys stimulated with Ang II;c and d : corresponding phase contrast microscopy. B. Pericytes cultured in the pro-diabetic environment, were loaded for 30 min at 37oC with 5mM DCF-DA .The effect of high glucose concentration, AGE-Lys and their combination with Ang II on intracellular calcium Ca2+i Detection of O2- production by dihydroethidium staining in mesangial cells overexpressing PKC-2SuperoxideSuperoxide production in production in nonatherosclerotic nonatherosclerotic and atherosclerotic arteriesand atherosclerotic arteriesnonatherosclerotic arteries atherosclerotic arteriesExpression of NAD(P)H Expression of NAD(P)H oxidaseoxidase subunits in subunits in nonatheroscleroticnonatherosclerotic and atherosclerotic arteries and atherosclerotic arteriesIn situ detection of In situ detection of superoxidesuperoxide in sham- in sham- operated and injured carotid arteriesoperated and injured carotid arteriesPossible antioxidative agents for diabetic vascular complicationsThank you!