title: PKCε mediates resistin-induced NADPH oxidase activation and inflammation leading to smooth muscle cell dysfunction and intimal hyperplasia.
abstract: Resistin has been implicated in cardiovascular disease and poor interventional cardiovascular outcomes. Previous studies by our group demonstrated resistin promoted vascular smooth muscle cell (VSMC) migration through protein kinase C epsilon (PKCε) pathways, while few others showed that resistin induced reactive oxygen species (ROS) generation in various cell types. In this study, we aim to systemically examine the functional role of resistin at the cellular and tissue levels as well as the potential mechanistic relationship between resistin-induced PKCε activation and ROS production.
  
  
  
  Plasma collected from patients undergoing carotid interventions was analyzed for resistin level and ROS. VSMCs were treated with resistin in the presence or absence of PKCε and NADPH oxidase (Nox)-specific inhibitors. Intracellular ROS production was analyzed using confocal microscopy and Nox activity with chemiluminescence. In vivo studies were performed in apolipoprotein E knock out (ApoE-/-) mice to determine therapeutic effects of PKCε-specific inhibitor, using the guide-wire injury model.
  
  
  
  We observed significant correlation between plasma resistin and circulating levels of oxidative stress in patients with severe atherosclerotic disease. We also demonstrated that resistin induced ROS production via PKCε-mediated Nox activation. Resistin-induced ROS production was time-dependent, and Nox4 was the primary isoform involved. Inhibition of Nox completely abolished resistin-exaggerated VSMC proliferation, migration and dedifferentiation, as well as pro-inflammatory cytokine release. Upstream modulation of PKCε significantly reduced resistin-mediated cytosolic ROS, Nox activity and VSMC dysfunction. Moreover, PKCε-specific inhibitor mitigated resistin-induced Nox activation and intimal hyperplasia in ApoE-/-mice.
  
  
  
  Resistin-associated VSMC dysfunction and intimal hyperplasia are related to PKCε-dependent Nox activation and ROS generation. Targeting the PKCε-Nox pathway may represent a novel strategy in managing resistin-associated atherosclerotic complications.
authors: Department of Vascular Surgery, VAPHCS, Palo Alto, CA, USA.
authors: Gayatri
authors: G
authors: Raghuraman
authors: Department of Vascular Surgery, VAPHCS, Palo Alto, CA, USA.
authors: Mary C
authors: MC
authors: Zuniga
authors: Department of Vascular Surgery, VAPHCS, Palo Alto, CA, USA.
authors: Hai
authors: H
authors: Yuan
authors: Department of Vascular Surgery, VAPHCS, Palo Alto, CA, USA; Department of Surgery, Stanford University, Stanford, CA, USA. Electronic address: weizhou@stanford.edu.
authors: Wei
authors: W
authors: Zhou
mesh_terms: D000368:Aged; D000818:Animals; D002318:Cardiovascular Diseases / Q000378:metabolism; D002339:Carotid Arteries / Q000473:pathology; D002465:Cell Movement; D049109:Cell Proliferation; D003331:Coronary Vessels / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007249:Inflammation / Q000378:metabolism*; D028421:Isoprostanes / Q000097:blood; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D000074085:Mice, Knockout, ApoE; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism*; D018384:Oxidative Stress; D011493:Protein Kinase C / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D052243:Resistin / Q000378:metabolism*; D017539:Tunica Intima / Q000473:pathology; D014945:Wound Healing
chemical_list: D028421:Isoprostanes; C499624:RETN protein, human; D017382:Reactive Oxygen Species; D052243:Resistin; C499623:Retn protein, mouse; D019255:NADPH Oxidases; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon
keywords: Inflammation; Intimal hyperplasia; NADPH-oxidase; Protein kinase C epsilon; Resistin; Vascular smooth muscle cell