Protective effects ROS up-regulation on premature ovarian failure by suppressing ROS-TERT signal pathway.

Abstract

Premature ovarian failure (POF) refers to the condition of pre-onset ovarian function failure, and is one commonly occurred disease in gynecology. Its pathogenic mechanism, however, is still unclear. Early study found decreased activity of telomerase reverse transcriptase (TERT). As an important factor to suppress TERT, oxidative stress has not been studied in POF. We, thus, investigated the role of reactive oxygen species (ROS)-TERT in POF. Rat POF model was induced by a single intraperitoneal injection of cyclophosphamide plus 12 mg/kg busulfan. Level of follicle stimulating hormone (FSH) and inhibin B was measured by enzyme-linked immunosorbent assay (ELISA), along with hematoxylin and eosin (HE) staining to confirm successful generation of models. Western blot was applied to measure TERT expression, and N-acetyl-cysteine (NAC) or TERT small interfere RNA (siRNA) was injected to suppress ROS or TERT level, followed by HE staining to observe POF condition. In POF model, ovary tissues showed atrophy, less follicles, and more follicular atresia, plus mesenchymal hyperplasia. FSH and inhibin B level were significantly up-regulated and down-regulated, respectively (p<0.05). In POF rat, ROS level was elevated (p<0.05) whilst TERT level was decreased. NAC inhibited ROS level and enhanced TERT expression. In contrast, TERT siRNA further aggravated POF condition. ROS up-regulation inhibits TERT expression, suppresses TERT activity and facilitates POF. The ROS-TERT pathway may work as the target for treating POF.