Human cumulus cells (hCC) express a functional hCG/LH receptor (LHR): Rol in steroidogenesis and cumulus expansion (CE).

ARRIAGADA C; VILLARROEL C; PUSTOVRH C; CASTRO O; KOHEN P; SALINAS A; MUÑOZ A; GODOY A; POMMER R; DEVOTO L

Barcelona

Congreso; Ovarian Club; 2011

Introduction: Ovulation is a complex process that is driven by LH surge. Studies in rat model have suggested that LH acts indirectly on cumulus cells to induce CE, meiosis resumption and progesterone (P4) secretion. These findings have not been studied in humans. Aims: 1) To determine the expression of LHR on hCC 2) to study the effect of hCG on steroidogenesis and CE in primary cultures of hCC. Material and methods: hCC were obtained from cumulus-oocyte complex of normal healthy women participating in IVF cycles due to a male factor. hCC were cultured for 24 hours in DMEM/F-12 medium for hCG deprivation. Subsequently, hCC were stimulated with hCG (10UI/ml) for 12 hours. The expression of LHR, enzymes involved in the steroidogenic machinery (StAR, P450scc, 3¦Â-HSD), CE (HAS-2, Conexin-43, COX2) and EGF-L growth factors (amphiregulin, epiregulin, betacelullin) were quantified by qRT-PCR and /or immunocytochemistry at 0 and after 12 hours of hCG stimuli. P4 secretion was measured in the culture media by RIA. Results: LHR expression was lower in hCC than in mural granulosa cells. hCG induced a rise in StAR(P=0.0001), P450scc (P<0.05), 3¦Â-HSD (P¡Ü0.01) and P4 levels in culture media (P<0.001). A rise epiregulin (P<0.02); HAS-2 (P<0.04), COX2 (P<0.01), but not in Conexin-43 were observed. Conclusion: These findings suggest that the LHR is functionally expressed in hCC .These results indicate that hCG acts directly through its own receptor on hCC stimulating P4 secretion and the proteins involved in cumulus expression (FONDAP 15010006, Fogarty Grant RFA-TW-05-002) to LD