Expression of molecules associated with tissue homeostasis in secretory endometria from untreated women with polycystic ovary syndrome

BACKGROUND: The hormonal alterations observed in women with polycystic ovary syndrome (PCOS) may promote implantation failure as well as disruption of their endometrial homeostasis. To evaluate cell survival of mid-secretory endometrium from untreated women with PCOS, we measured the expression of apoptosis and proliferation-related proteins. METHODS: A case-control study of 11 patients with PCOS and 11 fertile women in the Hospital Research Unit was performed. Endometrial samples were obtained from PCOS women (PCOSE) and fertile healthy women (CE) during the mid-secretory phase of the menstrual cycle. Protein expressions for Akt, p-AktSer473 and p-AktThr308, Bad, p-BadSer136, Bcl-2, Bax and pro-caspase-3/caspase-3, were assessed by western blot, and Ki67 and p-histone-3 (p-H3) by immunohistochemistry. RESULTS: In CE and PCOSE, a predominance of p-AktThr308 over p-AktSer473 is observed; p-BadSer136 expression is higher in PCOSE than in CE (P < 0.05). Also, Bcl-2 protein is overexpressed in PCOSE (P < 0.05), with no changes in Bax expression among the two groups, resulting in a significantly higher Bcl-2/Bax ratio in PCOSE than in CE (P < 0.05). No changes in the expression of caspase-3 are obtained between both groups of endometria. Furthermore, cell proliferation detected by the expression of Ki67 and p-H3 proteins is higher in the epithelia than the stroma of PCOSE versus CE (P < 0.05). CONCLUSION: The abnormal tissue homeostasis exhibited by the secretory endometrium from PCOS patients with spontaneous ovulation may interfere with their endometrial receptivity.