Effects of recombinant activins on steroidogenesis in XXXX granulosa-lutein cells.

@entity1 @entity624 @entity1420 @entity23385 @entity53 @entity134 @entity14877 @entity12440 @entity10548
CONTEXT: Exerting a broad range of biological effects in various tissues, activins are homo- or heterodimers of activin/inhibin b-subunits (bA, bB, bC, and bE in @entity1 ). Although activins A (bAbA), B (bBbB), @entity12440 (bAbB), and AC (bAbC) have been demonstrated in the female reproductive system, little is known about their individual functions in the ovary. OBJECTIVE: To investigate the biological roles and activities of activins in regulating steroidogenesis in @entity1 granulosa cells. DESIGN: @entity1 granulosa-lutein cells obtained from 32 @entity1 undergoing in vitro fertilization were used to investigate the effects of activin A, B, @entity12440 , and AC on the expression of steroidogenic enzymes and @entity134 production. SETTING: An academic research center. MAIN OUTCOME MEASURES: mRNA and protein levels were examined by reverse transcription quantitative real-time PCR and Western blot analysis, respectively. The production of @entity53 and @entity1420 was measured by enzyme immunoassay. RESULTS: P450 aromatase, @entity23385 , and @entity53 levels were increased, whereas @entity624 ( @entity624 ), @entity10548 , and @entity1420 levels were decreased after treatment with activin A, B, and @entity12440 , but not activin AC. FSH or LH induced the production of aromatase/ @entity53 and @entity624 / @entity1420 ; however, pretreatment with activin A, B, or @entity12440 enhanced the effects of gonadotropins on aromatase/ @entity53 , but suppressed their effects on @entity624 / @entity1420 . Treatment with activin A, B, or @entity12440 induced the phosphorylation of SMA- and MAD-related proteins ( @entity14877 ), whereas activin AC had no such effects. Furthermore, co-culture of activin AC (1-100 ng/mL) with activin A (25 ng/mL) did not alter the effects of activin A on P450 aromatase or @entity624 mRNA levels. CONCLUSION: Activin A, B, and @entity12440 have similar effects on steroidogenesis in @entity1 granulosa cells. In contrast, activin AC is not biologically active and does not act as a competitive antagonist.
