The expression of heat shock protein 70, heat shock protein 90 and heat shock factor 1 within the bovine midcycle corpus luteum after stimulation with temperature in vitro and PGF2alpha in vitro and in vivo

Environmental and biological stressors affect cellular function. Heat shock proteins (HSPs) are molecular chaperones that safeguard cells against these stressors by protecting endogenous proteins from degradation. Heat shock factors (HSF) are their transcriptional regulators. In the present study, we evaluated whether heat (Experiment 1) or prostaglandin F2alpha (PGF2alpha; Experiments 2 and 3) induces the expression of HSP 70, HSP 90 and HSF1 in the bovine corpus luteum (CL). In summary, in vitro heat treatment elicited a later response in luteal cells by increasing HSP 70 expression at 24 hrs, while in vivo PGF2alpha treatment leads to an earlier response by increasing HSP 90 expression at 30 min. This was not due to differential HSF 1 expression. Thus, we conclude that heat shock and PGF2alpha appear to induce the expression of specific HSPs in the bovine corpus luteum in a time-dependent manner. (Abstract shortened by UMI.).