Exogenous nitric oxide negatively regulates the S-nitrosylation p38 mitogen-activated protein kinase activation during cerebral ischaemia and reperfusion.
OBJECTIVE
A number of studies have suggested that nitric oxide (NO) plays an important role in the reactive phosphorylation of p38MAPKα (p38). However, whether S-nitrosylation of p38 is activated by NO and the details remain unclear. The aim of the present work was to assess the activation of p38, the S-nitrosylation site and the p38 signalling pathway in rat hippocampus and in HEK293 cell induced by exogenous NO.


METHODS
Primary hippocampal cultures, HEK293 cells and rat model of cerebral ischaemia/reperfusion (brain ischaemia was induced by four-vessel occlusion procedure) were used in this study. Biotin-switch method and immunoblotting were performed to study the S-nitrosylation and phosphorylation of p38, and neuronal loss was observed by histology.


RESULTS
Endogenous NO increased p38 phosphorylation and S-nitrosylation, and the activation of p38 was dependent on the S-nitrosylation of Cys-211, which was critical for the NO-mediated activation of p38. The exogenous NO donor sodium nitroprusside, S-nitrosoglutathione, 7-nitroindazole, the inhibitor of the neuronal nitric oxide synthase, inhibited the activation of p38 signal pathway induced by cerebral ischaemia/reperfusion and attenuated the damage in rat hippocampal neurones. Moreover, the N-methyl-D-aspartate receptor (NMDAR) is probably involved in the p38 activation process of S-nitrosylation and phosphorylation.


CONCLUSIONS
Endogenous NO induces the S-nitrosylation and phosphorylation of p38 and mediates p38 signalling pathway by NMDAR, and as exogenous NO inhibits this process and is neuroprotective in rat cerebral ischaemia/reperfusion, it may make a contribution to stroke therapy.
Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, China.
S H
SH
Qi
L Y
LY
Hao
J
J
Yue
Y Y
YY
Zong
G Y
GY
Zhang
D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D057809:HEK293 Cells; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015151:Immunoblotting; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D009569:Nitric Oxide; D048051:p38 Mitogen-Activated Protein Kinases