Keratinocyte growth factor promotes the survival, growth, and differentiation of preantral ovarian follicles

Objective: To determine the effect of treatment with keratinocyte growth factor (KGF) on the survival of cells in cultured preantral follicles and on the growth and differentiation of preantral follicles. Design: Preantral follicles (140–150 μm) were dissected mechanically from the ovaries of 14-day-old rats and cultured for 24 hours with and without KGF. Genomic DNA was extracted, labeled with [ 32P]-dideoxy-adenosine triphosphate, and fractionated through agarose gels. For growth studies, the follicles were cultured individually in 96-well dishes. After 72 hours, the follicles were collected and their protein or DNA content was evaluated and their inhibin-α content was determined. Result(s): Keratinocyte growth factor suppressed apoptosis in cultured preantral follicles by 60%. Treatment with KGF or FSH increased follicle diameter by 8% and 16%, respectively, and combined treatment with KGF and FSH increased follicle diameter by 26%. Western blot analysis demonstrated increased expression of inhibin-α content after treatment with KGF (2-fold), treatment with FSH (4-fold), and combined treatment with FSH and KGF (12-fold), demonstrating the effect of KGF on preantral follicle differentiation. Conclusion(s): Treatment with KGF promotes the survival, growth, and differentiation of cultured preantral follicles. Keratinocyte growth factor produced by theca cells may play a role in the progression of early follicle development.