Reperfusion and neurovascular dysfunction in stroke: from basic mechanisms to potential strategies for neuroprotection.
Effective stroke therapies require recanalization of occluded cerebral blood vessels. However, reperfusion can cause neurovascular injury, leading to cerebral edema, brain hemorrhage, and neuronal death by apoptosis/necrosis. These complications, which result from excess production of reactive oxygen species in mitochondria, significantly limit the benefits of stroke therapies. We have developed a focal stroke model using mice deficient in mitochondrial manganese-superoxide dismutase (SOD2-/+) to investigate neurovascular endothelial damage that occurs during reperfusion. Following focal stroke and reperfusion, SOD2-/+ mice had delayed blood-brain barrier breakdown, associated with activation of matrix metalloproteinase and high brain hemorrhage rates, whereas a decrease in apoptosis and hemorrhage was observed in SOD2 overexpressors. Thus, induction and activation of SOD2 is a novel strategy for neurovascular protection after ischemia/reperfusion. Our recent study identified the signal transducer and activator of transcription 3 (STAT3) as a transcription factor of the mouse SOD2 gene. During reperfusion, activation of STAT3 and its recruitment into the SOD2 gene were blocked, resulting in increased oxidative stress and neuronal apoptosis. In contrast, pharmacological activation of STAT3 induced SOD2 expression, which limits ischemic neuronal death. Our studies point to antioxidant-based neurovascular protective strategies as potential treatments to expand the therapeutic window of currently approved therapies.
Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305-5487, USA. sheri76@hanmail.net
Joo Eun
JE
Jung
Gab Seok
GS
Kim
Hai
H
Chen
Carolina M
CM
Maier
Purnima
P
Narasimhan
Yun Seon
YS
Song
Kuniyasu
K
Niizuma
Masataka
M
Katsu
Nobuya
N
Okami
Hideyuki
H
Yoshioka
Hiroyuki
H
Sakata
Christina E
CE
Goeders
Pak H
PH
Chan
D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D018384:Oxidative Stress; D015427:Reperfusion Injury / Q000150:complications / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D020521:Stroke / Q000150:complications / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000099156:Superoxide Dismutase 2
D019255:NADPH Oxidases; D018696:Neuroprotective Agents; D050796:STAT3 Transcription Factor; D013482:Superoxide Dismutase; D000099156:Superoxide Dismutase 2