BACKGROUND: The sirtuin family is well recognized for its crucial involvement in various cellular processes. Nevertheless, studies on its role in the human endometrium are limited. This study aimed to explore the expression and localization of the sirtuin family in the human endometrium, focusing on sirtuin 3 (SIRT3) and its potential role in the oxidative imbalance of the endometrium in polycystic ovary syndrome (PCOS). METHODS: Endometrial specimens were collected from both patients with PCOS and controls undergoing hysteroscopy at the Center for Reproductive Medicine, Peking University Third Hospital, from July to August 2015 and used for cell culture. The protective effects of SIRT3 were investigated, and the mechanism of SIRT3 in improving endometrial receptivity of patients with PCOS was determined using various techniques, including cellular bioenergetic analysis, small interfering ribonucleic acid (siRNA) silencing, real-time quantitative polymerase chain reaction, Western blot, immunofluorescence, immunohistochemistry, and flow cytometry analysis. RESULTS: The sirtuin family was widely expressed in the human endometrium, with SIRT3 showing a significant increase in expression in patients with PCOS compared with controls ( P <0.05), as confirmed by protein and gene assays. Concurrently, endometrial antioxidant levels were elevated, while mitochondrial respiratory capacity was reduced, in patients with PCOS ( P <0.05). An endometrial oxidative stress (OS) model revealed that the downregulation of SIRT3 impaired the growth and proliferation status of endometrial cells and reduced their receptivity to day 4 mouse embryos. The results suggested that SIRT3 might be crucial in maintaining normal cellular state by regulating antioxidants, cell proliferation, and apoptosis, thereby contributing to enhanced endometrial receptivity. CONCLUSIONS Our findings proposed a significant role of SIRT3 in improving endometrial receptivity in patients with PCOS by alleviating OS and regulating the balance between cell proliferation and apoptosis. Therefore, SIRT3 could be a promising target for predicting and improving endometrial receptivity in this patient population.
Humans ; Female ; Polycystic Ovary Syndrome/metabolism* ; Endometrium/metabolism* ; Sirtuin 3/genetics* ; Oxidative Stress/genetics* ; Adult ; Animals ; Mice ; Apoptosis/physiology* ; Immunohistochemistry ; Cell Proliferation/physiology*

Objective To investigate the effects of sex hormone-binding globulin (SHBG)gene in the apoptosis of human trophoblastic cells.Methods The siRNA specific-targeting SHBG gene was transfected into human trophoblastic cells and they were divided into six groups:trophoblasts without transfection in normal control groups(group Ⅰ);transfect liposome in blank control groups(group Ⅱ);transfect nonspecific siRNA in negative control groups(group Ⅲ);transfect SHBG siRNA-Ⅰ,SHBG siRNA-Ⅱ,SHBG siRNA-Ⅲ respectively in trans-fection group(group Ⅳ,Ⅴ,Ⅵ).Hoechst 33258 dying method was used to detect cell apoptosis.SHBG and Caspase-3 mRNA profiling and the level of SHBG and caspase-3 protein were detected by real-time PCR and Western blot.Results There was no statistical significant difference in the gene expression and protein level of SHBG and caspase-3 in group Ⅰ,Ⅱ and Ⅲ (P >0.05).In Ⅳ,Ⅴ and Ⅵ group,there was no statistical significant difference in the expression level of SHBG and caspase 3 (P >0.05).Compared with group Ⅰ,Ⅱ and Ⅲ,the a-mount of SHBG gene expression decreased obviously,the caspase-3 mRNA and protein level increased obviously and the trophoblast cell ap-optosis increased markedly (P <0.05).Conclusion Through siRNA interference technology can reduce SHBG gene expression in human trophoblastic cells,and it can lead to excessive apoptosis of human trophoblasts cells.