[Effect of microwave irradiation on expression of heat shock proteins family in primary cultured rat hippocampal neurons].

OBJECTIVE: To investigate the effects of microwave irradiation on the expression and regulation of heat shock proteins (HSPs) in primary cultured rat hippocampal neurons. METHODS: Neurons were exposed to 90 mW/cm(2) microwave irradiation for 10 minutes. Western blot was used to determine the expression of HSP27, HSP70, HSP90 and heat shock factor 1 (HSF1) at 0, 3, 6, 12 and 24 hour respectively. Real-time RT-PCR was used to determine the mRNA expression of HSF1. DNA-binding activity of HSF1 was measured by electrophoretic mobility shift assay (EMSA). RESULTS: The protein expression of HSP27 was significantly increased by 22%, 36%, 18% at 3, 6, 12 h, respectively (P < 0.05). The protein expression of HSP70 was significantly increased by 23%, 32%, 26% at 3, 6, 12 h, respectively (P < 0.05, P < 0.01). The protein expression of HSP90 was significantly increased by 27%, 33% at 6, 12 h, respectively (P < 0.05, P < 0.01). The DNA-binding activity of HSF1 was stimulated, however, no significant change of the expression of HSF1 was observed on both the mRNA and protein levels. CONCLUSION: The transcriptional activity of HSF1 is activated by microwave irradiation, which promotes the expression of HSPs. Heat shock response which contributes to establish a cytoprotective state is induced by microwave irradiation in primary cultured rat hippocampal neurons.