Bone morphogenetic proteins (BMP) 2, 4, 6 and 7 affect ovarian follicular development through regulation of follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) expression in goat granulosa cells

Bone morphogenetic proteins (BMPs), belonging to the transforming growth factor-beta family, are crucial factors in follicular growth and development in the mammalian ovary. In this study, we examined the effects of BMP2, 4, 6 and 7 on goat granulosa cells by in vitro culture. The results showed that BMP2, 4 and 7 increased follicle-stimulating hormone receptor (FSHR) level in goat granulosa cells whereas they decreased luteinizing hormone receptor (LHR) level in both transcript and protein levels; however, BMP6 upregulated LHR transcript and protein level in goat granulosa cells, whereas it had no effect on FSHR level. FSHR knockdown increased granulosa cell apoptosis. Our data provided the first evidence that BMP2, 4, 6 and 7 may inhibit granulosa cell apoptosis through the regulation of FSHR and/or LHR level. These findings provided new insight into the biological functions of BMP2, 4, 6 and 7 for follicular development in goat ovary.   Key words: Granulosa cell, bone morphogenetic proteins (BMPs), follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR)