Expression of Fas, Fas-ligand, Bcl-2 and Bad with Maturation of Human Ovarian Follicle

Kwon, Dong Jin; Kil, Ki Cheol; Jo, Hyun Hee; Kim, Mi Ran; Lim, Yong Taik; Kim, Jang Heub; Oak, You Young; Kim, Dai Hoon; Lee, Jin Woo; Kim, Jin Hong

Abstract

Human ovarian follicles reduce rapidly in number throughout fetal and adult life. Throughout the menstrual cycles, primordial follicles grow into mature follicles and then ovulate to form corpus luteum. Apoptosis has been implicated in several events that occur during the process of follicular growth, atresia and the regression of the corpus luteum. By the use of immunohistochemistry, we clarified the involvement of apoptosis in the human ovary during follicular growth, regression and atresia by investigating the expression of Fas, Fas-ligand, Bcl-2 and Bad in primordial follicles, primary follicles and mature follicles. Fas immunostaining was present in primordial oocytes, both oocytes and granulosa cells of primary follicles, preantral follicles and all follicular cells of mature follicles. Fas-ligand and Bad immunostaining patterns were similar to those of Fas except for theca cells. Bcl-2 immunostaining was present in both oocytes and granulosa cells of primary, preantral and mature follicles. In corpus luteum, Fas, Fas-ligand, Bcl-2 and Bad immunostaining were observed and decreased in the regressing corpus luteum. In postmenopausal ovary, Fas, Fas-ligand, Bcl-2 and Bad immunostaining were entirely negative. Bad immunostaining was observed but Bcl-2 was not in atretic follicle. These results suggest that Fas, Fas-ligand, Bcl-2 and Bad may play important roles in human ovary during follicular growth, regression and atresia simultaneously. Further studies should be required to elucidate the underlying mechanism and apoptosis of the disease associated with normal and abnormal ovarian aging.