[Protective effect of heat preconditioning on NIH-3T3 fibroblast]

To establish stress adaptation model of mouse fibroblast cell line NIH-3T3, to provide a group of parallel object for stress adaptation research, and to explore the function and mechanism of HSP90 in stress adaptation.

A stress-adapted cell model was established by thermal preconditioning (42 degrees C, 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 degrees C, 20 minutes). The HSP90 content was detected by Western blot.

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 OD(HSP90)/OD(control) value indicated that the cellular HSP90 contents was decreased immediately after heat stress (44 degrees C, 40 min). The content of HSP90 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.

With the preconditioning for the NIH-3T3, the time point for the stress protection is confirmed, the model for the cellular stress adaptation is established and the protective effect of HSP90 is primarily confirmed in this model.