预热适应对NIH-3T3细胞的保护作用

Protective effect of heat preconditioning on NIH-3T3 fibroblast

目的建立小鼠成纤维细胞系NIH-3T3预热适应细胞模型,探讨应激与适应对细胞活性和热休克蛋白90(HSP90)合成的影响。方法通过预热适应(42℃,20 min)建立应激适应细胞模型,并通过再次热应激时(44℃,40min)细胞膜损伤指标、DNA损伤指标的变化综合评价适应效果。以Western blot法检测应激及适应对细胞内HSP90合成的影响。结果结合预热适应后再次热应激所致的细胞膜损害和HSP90合成情况,初步确定预热适应后6 h为最佳应激保护时间。预热适应6 h后,再次热应激时,培养液中乳酸脱氢酶(LDH)漏出变化率为15．4%±2．6%,对照组为41．2%±5．1%；DNA受损细胞所占百分比为15．1%,较直接热应激组(26．3%)轻。OD_(HSP90)/OD_(control)变化趋势显示热应激40min后细胞内HSP90含量均呈下降趋势,直接热应激组为0．82±0．18,预热适应组为1．70±0．52,预热适应+热应激组为1．41±0．16。结论通过对NIH-3T3细胞进行预热处理,确定应激保护的时间点,建立了细胞应激适应模型；初步确认HSP90在该模型中的保护作用。

Objective To establish stress adaptation model of mouse fibroblast cell line NIH-3T3, to provide a group of parallel object for stress adaptation researeh, and to explore the function and mechanism of HSP90 in stress adaptation. Methods A stress-adapted cell model was established by thermal preconditioning（42 %, 20 minutes） ,and the adaptation result was evaluated by observing the change of the membrane injury and the damage of DNA induced by the heat stress for the second time（44 ℃ ,20 minutes）. The HSP90 content was detected by Western blot. Results According to the membrane injury and HSP90 synthesis induced by the heat stress for the second time, it was primarily confirmed that 6 hours after thermal preconditioning were the optimum stress protection time. When cells underwent heat stress for the second time 6 hours after thermal preconditioning, the membrane injury（ 15.4% ± 2.6 % vs 41.2 % ±5.1% ）, damage of DNA（ 15.1% vs 26.3 % ） were decreased compared with the control group in which there was no preconditioning. The ODHSP90/ODcontrol value indicated that the cellular HSP90 contents was decreased immediately after heat stress（44 ℃, 40 min）. The content of HS900 was 0.82 ± 0.18 in the heat stress group, 1.70 ± 0,52 in the preconditioning group and 1. 41 ± 0.16 in the heat stress after preconditioning group. Conclusion With the preconditioning for the NIH-3T3, the time point for the stress protection is confirmed, the model for the cellular stress adaption is established and the protective effect of HStO0 is primarily confirmed in this model.