%0 Journal Article
%T Normobaric hyperoxia protects the blood brain barrier through inhibiting Nox2 containing NADPH oxidase in ischemic stroke
%A Wenlan Liu
%A Qingquan Chen
%A Jie Liu
%A Ke Liu
%J Medical Gas Research
%D 2011
%I BioMed Central
%R 10.1186/2045-9912-1-22
%X Normobaric hyperoxia (NBO) has been shown to effectively reduce tissue infarction and protect the blood brain barrier (BBB) in animal ischemic stroke models [1-6]. These neuro- and vaso-protective effects make NBO a promising approach to expand the narrow time window of the reperfusion therapies for ischemic stroke [7]. Indeed, recent studies showed that NBO treatment during cerebral ischemia significantly reduced the neurovascular complications in delayed tPA treatment in a rat model of ischemic stroke [8,9]. In human studies, NBO treatment was associated with improvements in clinical deficit and survival in selected stroke patients [10,11]. Increasing oxygen level, particularly over-oxygenation, with oxygen therapy may result in oxidative stress and free radical damage. Interestingly, NBO treatment for ischemic stroke does not increase oxidative stress [2], instead, it may decrease reactive oxygen species (ROS) production [3]. However, it remains to be elucidated how NBO affects ROS production in the ischemic brain.Several oxidant enzyme systems, such as xanthine oxidase, mitochondrial respiratory chain and NADPH oxidase have been identified as important source of ROS in the brain and contribute to oxidative brain injury following cerebral ischemia and reperfusion [12,13]. Accumulating evidence from animal stroke studies suggests that Nox is strongly implicated in the oxidative damage to the neuronal tissue and the BBB in ischemic stroke [14-18]. NADPH oxidase was first found in phagocytes, which is assembled from a membrane spanning flavocytochrome b558, composed of Nox2 (also called gp91phox) and p22phox and four cytosolic factors (p47phox, p67phox, p40phox, and Rac) that associate with the flavocytochrome to form an active enzyme [19]. Recently, several novel homologs of the catalytic, electron carrier component of NADPH oxidase (gp91phox or Nox2) have been described in a variety of nonphagocytic cells, including Nox1, Nox3, Nox4, Nox5, Duox1 and Duox2 [20]. Am
%U http://www.medicalgasresearch.com/content/1/1/22