Heat Shock Protein 70 and Sex Steroid Receptors in the Follicular Structures of Induced Ovarian Cysts

Abstract

The purpose of this study was to estimate the expression and relative amounts of estrogen (ER) and progesterone receptors (PR) and their isoforms as well as heat shock protein 70 (HSP70) in ovaries of rats with induced cystic ovarian disease (COD). Primary, secondary, tertiary, atretic, and cystic follicles were evaluated by immunohistochemistry and total ovarian proteins were analyzed by Western blot. In the granulosa layer, growing and cystic follicles in the treated group have a higher expression of ERá than growing follicles of control individuals. In the theca interna layer, the tertiary follicles presented a significantly higher expression of ERá in the treated group. An increase in the total ERá protein was detected in the treated group. Granulosa cells of all growing, atretic, and cystic follicles show a lower expression of ERâ in animals with COD and the total protein expression of ERâ was lower in this group. The expression of PR was lower in the granulosa cell layer of tertiary and cystic follicles in treated animals and theca interna layer had less intense immunostaining in this group. Although there were no differences in the expression of PR-B by Western blotting, the expression of PR-A was higher and the expression of PR-C was smaller in the treated group. An intense HSP70 immunostaining was observed in the cells of cystic follicles. By Western blotting, higher protein expression of HSP70 was detected in the ovarian samples of the control group than those of the treated ones. Ovaries of animals with COD exhibited an altered steroid receptor expression and subtype balance compared with control animals, and an increase in the HSP70 immunoexpression.