[Roles of nuclear factor-kappaB in heat shock pretreatment to abate cardiomyocyte injury induced by hydrogen peroxide].
OBJECTIVE
To investigate the role of nuclear factor-kappaB (NF-kappaB) in heat shock pretreatment to abate cardiomyocyte injury induced by hydrogen peroxide (H(2)O(2)).


METHODS
The primary generation of cultured neonatal rat cardiomyocytes were injured by exposure to 1 mmol/L H(2)O(2) for different durations. The total antioxidant in cardiomyocytes was detected. The changes in heat shock protein 70 (HSP70), alphaB-crystallin, inhibitor of NF-kappaB (I-kappaB) were assayed by Western-blotting. The translocation of NF-kappaB and HSP70 from cytoplasm to nucleus was observed by immunohistochemical analysis.


RESULTS
(1)Compared with H(2)O(2) (1 mmol/L, 3 h) treated cells, cells subjected to heat shock pretreatment showed significant increase in total antioxidant capability (all P<0.01). (2)Western blot analysis demonstrated that heat shock pretreatment could induce expression of HSP70, alphaB-crystallin and I-kappaB. (3)Heat shock pretreatment inhibited H(2)O(2)-mediated I-kappaB degradation. (4)Immunohistochemical analysis showed that heat shock pretreatment could abate HSP70 and NF-kappaB translocation from cytoplasm to nucleus.


CONCLUSIONS
Heat shock pretreatment could protect cardiomyocytes against H(2)O(2)-induced injury, and its mechanism might involve expression of HSP70, alphaB-crystallin and I-kappaB, which could inhibit H(2)O(2) -mediated NF-kappaB activation.
Tu
Zi-zhi
ZZ
Department of Pathophysiology, Xiangya Medical College, Central South University, Changsha 410078, Hunan, China.
Xiao
Wei-min
WM
Liu
Mei-dong
MD
You
Jia-lu
JL
Xiao
Xian-zhong
XZ
D000818:Animals; D002478:Cells, Cultured; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D020672:I-kappa B Proteins / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D016328:NF-kappa B / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D038203:alpha-Crystallin B Chain / Q000378:metabolism
D018840:HSP70 Heat-Shock Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; D038203:alpha-Crystallin B Chain; D006861:Hydrogen Peroxide