PHYSIOLOGICAL ROLES OF INTEGRIN ALPHA(6)BETA(1) IN OVARIAN FUNCTIONS

We previously reported that human ovarian cells express integrin beta( 1) families. The physiological role(s) of integrins was investigated u sing in vitro human granulosa cell culture and in vivo mouse ovulation model. In human luteinizing granulosa cell culture obtained from the patients undergoing in vitro fertilization treatment, laminin, which i s a ligand for integrin alpha(6)beta(1), suppressed the production of progesterone by granulosa cells. On the other hand, the anti-as monocl onal antibody (mAb) GoH3, which partially inhibits the interaction bet ween integrin alpha(6)beta(1) and laminin, enhanced production of prog esterone by 2-fold of the control under the culture with laminin, indi cating that integrin alpha(6)beta(1) regulates the luteinization of hu man granulosa cell during the periovulatory phase. In an immature supe rovulated 13-day-old ICR (CD-I) mice model, intraperitoneal administra tion of GoH3 induced successful ovulation, whereas no ovulation was ob served in the GoH3-nontreated groups, showing that integrin alpha(6)be ta(1) is related to gonadotropin-induced follicular growth. These find ings suggest that the interaction between integrin alpha(6)beta(1) and laminin plays an important role in the corpus luteum formation and fo llicular growth.