Regulatory role of BMP-9 in steroidogenesis by XXXX ovarian granulosa cells.

@entity268 @entity22344 @entity24535 @entity1420 @entity52801 @entity53 @entity35
UNASSIGNED: BMPs expressed in the ovary differentially regulate steroidogenesis by granulosa cells. BMP-9, a circulating BMP, is associated with cell proliferation, apoptosis and differentiation in various tissues. However, the effects of BMP-9 on ovarian function have yet to be elucidated. Here we investigated BMP-9 actions on steroidogenesis using @entity35 primary granulosa cells. BMP-9 potently suppressed FSH-induced @entity1420 production, whereas it did not affect FSH-induced @entity53 production by granulosa cells. The effects of BMP-9 on FSH-induced steroidogenesis were not influenced by the presence of oocytes. FSH-induced @entity268 synthesis and FSH-induced mRNA expression of steroidogenic factors, including StAR, P450scc, 3bHSD2 and @entity52801 , were suppressed by treatment with BMP-9. BMP-9 mRNA expression was detected in granulosa cells but not in oocytes. BMP-9 readily activated @entity22344 /8 phosphorylation and Id-1 transcription in granulosa cells. Analysis using ALK inhibitors indicated that BMP-9 actions were mediated via type-I receptors other than ALK-2, -3 and -6. Furthermore, experiments using extracellular domains (ECDs) for BMP type-I and -II receptor constructs revealed that the effects of BMP-9 were reversed by ECDs for ALK-1 and @entity24535 . Thus, the functional receptors for BMP-9 in granulosa cells were most likely to be the complex of ALK-1 and @entity24535 . Collectively, the results of the present study showed that BMP-9 can affect luteinization and that there are two possible sources of BMP-9, serum and granulosa cells in the ovary.
