Abstract: 【Objective】The objectives of this study were to reveal whether or not the calmodulin (CaM) gene participates in HSP70 gene expression in the mouse fetal fibroblasts and to definite their participating conditions. 【Method】 The 12.5-day mouse embryo of pregnancy was taken to culture its fibroblasts (MEF). The fibroblasts were divided into control group and heat shock group randomly. The heat shock group was further divided into groups of Ⅰ(39℃ for 0.5 h), Ⅱ(39℃ for 1 h), Ⅲ(39℃ for 1.5 h), Ⅳ(41℃ for 0.5 h), Ⅴ(41℃ for 1 h) and Ⅵ(41℃ for 1.5 h) , respectively, while the control group was treated at 37℃. Three replicates were performed for each group. The optimum heat stress group was then selected. Calmodulin antagonist W7 was applied to both the selected and control group with different concentrations (25, 50, and 100 mmol·L-1) in parallel. Both expressions of Hsp70 and CaM mRNA were detected by using the method of RT-PCR. 【Result】 The expressions of Hsp70 mRNA in both 39℃ and 41℃ groups were significantly higher than that of the control group (P＜0.05). However, the expression of Hsp70 mRNA in the group treated at 39℃ for 1h was significantly higher compared with other groups (P＜0.01). The expressions of CaM mRNA in the groups treated both at 39℃ for 0.5 h and 39℃ for 1 h were significantly higher than that in other groups (P＜0.01). There was no difference in CaM mRNA expression in the group treated at 41℃ compared with the control group (P＞0.05). The expressions of Hsp70 mRNA in the groups of 37℃ and 39℃ for 1 h treated with 100 mmol·L-1 W7 were significantly lower than that in corresponding control group (P＜0.01). 【Conclusion】 There is a positive correlation between Hsp70 and CaM gene expression under moderate heat shock and the treatment at 39℃ for 1 h induced both Hsp70 and CaM gene expressions. The CaM gene participates in HSP70 gene expression.

Key words: mouse embryonic fibroblasts , heat shock , Hsp70 , CaM , mRNA