title: Transgenic overexpression of peroxiredoxin-2 attenuates ischemic neuronal injury via suppression of a redox-sensitive pro-death signaling pathway.
abstract: OBJECTIVE
  Peroxiredoxins (PRXs) are a newly characterized family of peroxide scavenging enzymes that not only help maintain cellular redox homeostasis but also may directly engage in a variety of intracellular signaling pathways. PRX2 is a neuronal-specific PRX believed to participate in cerebral antioxidant responses in several neurodegenerative diseases. This study investigates the potential neuroprotective effect and the underlying mechanism of PRX2 in models of ischemic neuronal injury.
  
  
  RESULTS
  Transgenic mice overexpressing PRX2 showed reduced brain injury and improved neurological recovery up to 3 weeks after transient focal cerebral ischemia compared to wild-type littermates. In primary cultures of cortical neurons, transfection of PRX2 but not the loss-of-catalytic-site PRX2 mutant conferred neuroprotection against cell death induced by oxygen glucose deprivation. PRX2 exhibited potent pro-survival effects in ischemic neurons by maintaining thioredoxin (Trx) in its reduced state, thereby preventing oxidative stress-mediated activation of apoptosis signal-regulating kinase 1 (ASK1) and the downstream MKK/JNK pro-death signaling pathway. PRX2 failed to provide additional neuroprotection against ischemic injury in Trx- or ASK1-knockdown neuron cultures and in mice treated with a JNK inhibitor.
  
  
  METHODS
  This study provides evidence that neuronal overexpression of PRX2 confers prolonged neuroprotection against ischemic/reperfusion brain injury. Moreover, the results suggest a signaling pathway by which PRX2 suppresses ischemia-induced neuronal apoptosis.
  
  
  CONCLUSIONS
  Enhanced neuronal expression and activity of PRX2 protect against ischemic neuronal injury by directly modulating the redox-sensitive Trx-ASK1 signaling complex.
authors.affiliation: Department of Neurosurgery and Cerebrovascular Diseases Research Institute, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gan
authors.forename: Xunming
authors.initials: X
authors.lastname: Ji
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Hu
authors.forename: Yumin
authors.initials: Y
authors.lastname: Luo
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Peiying
authors.initials: P
authors.lastname: Li
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
authors.forename: Peter
authors.initials: P
authors.lastname: Vosler
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Gao
authors.forename: R Anne
authors.initials: RA
authors.lastname: Stetler
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D020134:Catalytic Domain; D016923:Cell Death; D002478:Cells, Cultured; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000473:pathology*; D054464:Peroxiredoxins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D054464:Peroxiredoxins