Expression of inhibin-activin subunits, follistatin and smads in granulosa-luteal cells collected at oocyte retrieval

Purpose: To examine the expression of inhibin-activin subunits, follistatin, and Smads 2, 3 and 4 in granulosa-luteal cells at the time of oocyte retrieval. Methods: Quantitative reverse transcriptase-polymerase chain reaction was performed to quantify the mRNA expression of the investigated genes: inhibin a-subunit, inhibinactivin beta A- and beta B-subunits, follistatin, and Smads 2, 3 and 4. Results: alpha-, beta A- and beta B- subunits of inhibin-activin, and follistatin were all well expressed in granulosa-luteal cells obtained from either dominant or cohort follicles. a- subunits strongly correlated with Smad2 (p < 0.001). beta A- subunit significantly correlated with Smad4, p < 0.001. beta B- subunit significantly correlated with Smad2, p = 0.002, and follistatin expression strongly correlated with the expression of Smads 2 and 4 (p < 0.001 and = 0.007 respectively). Conclusions: We found, for the first time that inhibinactivin beta B- subunit mRNA was well expressed in human granulosa-luteal cells obtained from either dominant or cohort follicles. a-, beta A- and beta B- subunits and follistatin correlated with Smads to varied degrees, suggesting the active roles of the above genes at the time of oocyte retrieval.