Activation of nuclear factor kappa B during heat stress-induced neuronal apoptosis / 中国组织工程研究

ABSTRACT

BACKGROUND:Hyperpyrexia can induce a wide range of cel apoptosis in organisms, but no study has introduced the mechanism of heat stress-induced neuronal apoptosis. OBJECTIVE:To observe the effect of nuclear factor kappa B (NF-κB) signal pathway on heat stress-induced neuronal apoptosis through reactive oxygen species. METHODS:Heat stress model was established in the cel incubator. Heat stress group of cel s were incubated at 39,41,43℃for2hours,whilecontrolgroupofcelswereincubatedat37 ℃in5% CO2 for 2 hours. Apoptosis was analyzed by flow cytometry using Annexin V-FITC/PI staining. The expression levels of caspase-3 and p-NF-κB65 were determined by western blot analysis. The amounts of intracel ular reactive oxygen species were assayed by DCFH staining. In addition, the effect of MnTMPyP and PTDC on heat stress-induced apoptosis was also studied. RESULTS AND CONCLUSION:39 ℃ heat stress had no impact on the apoptosis, 41 ℃ heat stress induced a smal amount of apoptosis (10.19%), and 43 ℃ heat stress triggered a large amount of apoptosis (43.02%). The expression of caspase-3 and p-NF-κB65 was increased, in a temperature-dependent manner. In addition, both MnTMPyP and PTDC significantly decreased the heat stress-induced apoptosis and expression of caspase-3 and p-NF-κB65. Experimental findings indicate that, the increase of intracel ular reactive oxygen species may induce neuronal apoptosis, and NF-κB participates in the heat stress-induced neuronal apoptosis as the intermedial signal pathway.