title: Nitrosative stress induces peroxiredoxin 1 ubiquitination during ischemic insult via E6AP activation in endothelial cells both in vitro and in vivo.
abstract: OBJECTIVE
  Although there is accumulating evidence that increased formation of reactive nitrogen species in cerebral vasculature contributes to the progression of ischemic damage, but the underlying molecular mechanisms remain elusive. Peroxiredoxin 1 (Prx1) can initiate the antioxidant response by scavenging free radicals. Therefore, we tested the hypothesis that Prx1 regulates the susceptibility to nitrosative stress damage during cerebral ischemia in vitro and in vivo.
  
  
  RESULTS
  Proteomic analysis in endothelial cells revealed that Prx1 was upregulated after stress-related oxygen-glucose deprivation (OGD). Although peroxynitrite upregulated Prx1 rapidly, this was followed by its polyubiquitination within 6 h after OGD mediated by the E3 ubiquitin ligase E6-associated protein (E6AP). OGD colocalized E6AP with nitrotyrosine in endothelial cells. To assess translational relevance in vivo, mice were studied after middle cerebral artery occlusion (MCAO). This was accompanied by Prx1 ubiquitination and degradation by the activation of E6AP. Furthermore, brain delivery of a lentiviral vector encoding Prx1 in mice inhibited blood-brain barrier leakage and neuronal damage significantly following MCAO.
  
  
  CONCLUSIONS
  Nitrosative stress during ischemic insult activates E6AP E3 ubiquitin ligase that ubiquitinates Prx1 and subsequently worsens cerebral damage. Thus, targeting the Prx1 antioxidant defense pathway may represent a novel treatment strategy for neurovascular protection in stroke.
authors.affiliation: 1 Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Zhejiang University , Hangzhou, China .
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Tao
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.forename: Ling-Juan
authors.initials: LJ
authors.lastname: Hong
authors.forename: Ji-Yun
authors.initials: JY
authors.lastname: Huang
authors.forename: Ying-Mei
authors.initials: YM
authors.lastname: Lu
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Liao
authors.forename: Wei-Feng
authors.initials: WF
authors.lastname: Ye
authors.forename: Nan-Nan
authors.initials: NN
authors.lastname: Lu
authors.forename: Dan-Yan
authors.initials: DY
authors.lastname: Zhu
authors.forename: Qian
authors.initials: Q
authors.lastname: Huang
authors.forename: Kohji
authors.initials: K
authors.lastname: Fukunaga
authors.forename: Yi-Jia
authors.initials: YJ
authors.lastname: Lou
authors.forename: Ikuo
authors.initials: I
authors.lastname: Shoji
authors.forename: Christopher Stuart
authors.initials: CS
authors.lastname: Wilcox
authors.forename: En-Yin
authors.initials: EY
authors.lastname: Lai
authors.forename: Feng
authors.initials: F
authors.lastname: Han
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism; D008297:Male; D051379:Mice; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination / Q000502:physiology
chemical_list: D054464:Peroxiredoxins; D044767:Ubiquitin-Protein Ligases