CYR61 and CTGF mediate the stimulatory effect of amphiregulin on COX-2 expression in human granulosa-lutein cells

Amphiregulin (AREG), an epidermal growth factor (EGF)-like ligand, is the predominant epidermal growth factor receptor (EGFR) ligand in human follicular fluid and mediates the effects of luteinizing hormone (LH) on ovarian function. In this study, we investigated whether AREG regulates the expression of cysteine-rich angiogenic inducer 61 (CYR61) and connective tissue growth factor (CTGF), two key matricellular proteins involved in ovarian function, and whether they mediate AREG-induced cyclooxygenase-2 (COX-2) expression. Using the human granulosa cell tumor-derived KGN cell line and primary human granulosa-lutein (hGL) cells, we demonstrated that AREG treatment upregulated CYR61 and CTGF protein levels in an EGFR-dependent manner. Mechanistic analysis revealed that AREG-induced expression of CYR61 and CTGF was mediated through the ERK1/2, AKT, CREB, and YAP signaling pathways. Inhibition of these pathways using specific inhibitors or small interfering RNA blocked AREG-induced CYR61 and CTGF expression, indicating their essential roles in this process. Moreover, knockdown of CYR61 and CTGF attenuated AREG-induced COX-2 expression, establishing their role as key mediators of AREG signaling in human granulosa cells. Finally, our results showed that LH treatment induced the expression of CYR61 and CTGF, and this induction was attenuated by EGFR inhibition. Moreover, knockdown of CYR61 and CTGF reduced LH-induced COX-2 expression. These findings provide novel insights into the molecular mechanisms by which AREG regulates ovarian function and highlight potential targets for reproductive health research.