CHARACTERIZATION OF HYPOTHERMIA-INDUCED CELLULAR STRESS-RESPONSE IN MOUSE-TISSUES

Cells respond to adverse environmental conditions by expressing heat s hock proteins, which serve to protect cells from harmful effects of th e stress conditions. In this study we demonstrated that mice subjected to whole body hypothermia induced the cellular stress response, resul ting in the increased expression of hsp72 mRNA in brain, heart, kidney , liver, and lung. We performed a detailed analysis of the major param eters of the stress response and found that cold induction of hsp expr ession is mediated by heat shock factor 1 (HSF1), which is also respon sible for heat induction of the cellular stress response. However, the re are differences in the mechanisms of HSF1 activation by hypothermia versus hyperthermia, as hypothermia does not cause the hyperphosphory lation of HSF1 that is characteristic of heat-activated HSF1.