Comprehensive Assessment of the STIMs and Orais Expression in Polycystic Ovary Syndrome

Abstract

Background: Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disease characterized by irregular menstrual, hyperandrogenism, and polycystic ovaries. The definitive mechanism of the disorder is not fully elucidated. Store-operated Ca2+ entry (SOCE) plays a role in glucose and lipid metabolism, inflammation, hormone secretion, and cell proliferation. STIMs and Orais are the main elements of SOCE. The potential role of SOCE in PCOS pathogenesis remains unclear.

Methods: The expression of STIMs and Orais in granulosa cells (GCs) derived from 83 patients with PCOS and 83 controls were analyzed, respectively, by using quantitative reverse transcription polymerase chain reaction. Binary regression analysis was used to identify the factors affecting PCOS after adjusted by body mass index and age. Pearson correlation analysis was used to determine the association between PCOS phenotypes and SOCE genes expression.

Results: Significantly increased expression of STIM1, STIM2, Orai1, and Orai2 were observed in patients with PCOS compared with controls (P = 0.037, P = 0.004, P ≤ 0.001, and P = 0.013, respectively), whereas the expression of Orai3 was decreased (P = 0.003). In addition, the expression levels of STIMs and Orais were identified as the factors affecting PCOS (P < 0.05). The expressions of these genes were correlated with hormone level and antral follicle count (P < 0.05).

Conclusions: For the first time, our findings indicated that the elements of SOCE were differently expressed, where STIM1, STIM2, Orai1, and Orai2 significantly increased, whereas Orai3 decreased in PCOS GCs, which might be dominantly involved in dysfunction of ovarian GCs and hormonal changes in PCOS.

Keywords: Orai1; STIM1; STIM2; polycystic ovary syndrome; store-operated Ca2+ entry.