Downregulation of adiponectin system in granulosa cells and low levels of HMW adiponectin in PCOS
OBJECTIVE To test whether angiotensin II (AngII) could modulate apoptosis of human granulosa-lutein (GL) cells from gonadotropin-stimulated follicles. DESIGN In vitro assays on mural and cumulus granulosa cells. SETTING University laboratory and private IVF practice. PATIENT(S) One hundred six consecutive women undergoing 113 IVF cycles. INTERVENTION(S) Purified human GL mural or cumulus cells were cultured in serum-free media in the presence or absence of AngII with or without the AngII receptor blockers saralasin and CGP42112A. MAIN OUTCOME MEASURE(S) Detection of apoptosis using a fluorescent in situ marker for activated caspases. RESULT(S) Mural cells had approximately eightfold the amount of apoptosis compared with cumulus cells (average 0.23 vs. <0.03, respectively). With mural cells, AngII increased GL cell apoptosis versus untreated control samples (AngII 10(-)11 mol/L +6.5%; AngII 10(-9) mol/L +13.3%, and AngII 10(-7) mol/L +11.3%), an effect which was blocked by concurrent incubation with AngII receptor blockers. The AngII receptor blockers produced a significant decrease of apoptosis compared with control cultures (saralasin: 19.4%; CGP42112A: 28.9%). Neither AngII nor blockers had effect on cumulus cells. CONCLUSION(S) Preovulatory concentrations of AngII, most likely via AT2 receptors, increase apoptosis of cultured mural GL cells but have no effect on cumulus cells. Granulosa cells appear to be differentially regulated by AngII.