Oxidative stress increases phosphorylation of IkappaB kinase-alpha by enhancing NF-kappaB-inducing kinase after transient focal cerebral ischemia.
The IkappaB kinase (IKK) complex is a central component in the classic activation of the nuclear factor-kappaB (NF-kappaB) pathway. It has been reported to function in physiologic responses, including cell death and inflammation. We have shown that IKK is regulated by oxidative status after transient focal cerebral ischemia (tFCI) in mice. However, the mechanism by which oxidative stress influences IKKs after tFCI is largely unknown. Nuclear accumulation and phosphorylation of IKKalpha (pIKKalpha) were observed 1 h after 30 mins of tFCI in mice. In copper/zinc-superoxide dismutase knockout mice, levels of NF-kappaB-inducing kinase (NIK) (an upstream kinase of IKKalpha), pIKKalpha, and phosphorylation of histone H3 (pH3) on Ser10 were increased after tFCI and were higher than in wild-type mice. Immunohistochemistry showed nuclear accumulation and pIKKalpha in mouse brain endothelial cells after tFCI. Nuclear factor-kappaB-inducing kinase was increased, and it enhanced pH3 by inducing pIKKalpha after oxygen-glucose deprivation (OGD) in mouse brain endothelial cells. Both NIK and pH3 interactions with IKKalpha were confirmed by coimmunoprecipitation. Treatment with IKKalpha small interfering RNA significantly reduced cell death after OGD. These results suggest that augmentation of NIK, IKKalpha, and pH3 in response to oxidative stress is involved in cell death after cerebral ischemia (or stroke).
Song
Yun Seon
YS
Department of Neurosurgery, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA 94305-5487, USA. yssong@sookmyung.ac.kr
Kim
Min-Soo
MS
Kim
Hyun-Ae
HA
Jung
Bo-In
BI
Yang
Jiwon
J
Narasimhan
Purnima
P
Kim
Gab Seok
GS
Jung
Joo Eun
JE
Park
Eun-Hee
EH
Chan
Pak H
PH
D000818:Animals; D016923:Cell Death / Q000502:physiology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D004790:Enzyme Induction; D006657:Histones / Q000378:metabolism; D051550:I-kappa B Kinase / Q000378:metabolism*; D002546:Ischemic Attack, Transient / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018384:Oxidative Stress; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000097782:NF-kappaB-Inducing Kinase
D006657:Histones; D051550:I-kappa B Kinase; D020780:Matrix Metalloproteinase 9; D017346:Protein Serine-Threonine Kinases; D034741:RNA, Small Interfering; D013482:Superoxide Dismutase; D000097782:NF-kappaB-Inducing Kinase