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.
Conclusion: 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.