Sima Yizhen, Li Lisha, Xiao Chengzhen, Xu Leimei, Wang Ling, Chen Yisong
Department of Gynecology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China.
Laboratory for Reproductive Immunology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China.
Ann Transl Med. 2022 Aug;10(15):821. doi: 10.21037/atm-22-628.
Pelvic organ prolapse (POP) is a common degenerative disease among females. We previously reported that advanced glycation end products (AGEs), compounds derived from nonenzymatic glycoxidation reactions, accumulated in the human vaginal wall and impaired the function of fibroblasts in the pathogenesis of POP. This study investigated the apoptosis induced by AGEs in human uterosacral ligament fibroblasts and the underlying mechanism.
Human uterosacral ligament fibroblasts were cultured and identified. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to identify the expression of miR-4429, phosphatase and tensin homolog (PTEN), and caspase-3. Flow cytometric analysis was applied to detect the apoptosis rate of fibroblasts. Dual-luciferase reporter assay was performed to verify the relationship between miR-4429 and PTEN. The overexpression of miR-4429 and the inhibition of PTEN were achieved by cell transfections. Western blot analysis was used to detect the protein levels of PTEN, phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt).
The AGEs promoted fibroblast apoptosis both in the POP and the non-POP groups. The expression of PTEN increased in fibroblasts from the POP group or fibroblasts treated with AGEs. It was confirmed that miR-4429 interacted with PTEN messenger RNA (mRNA), and the expression level of miR-4429 was reduced in fibroblasts from the POP group or fibroblasts treated with AGEs. Further, overexpression of miR-4429 alleviated increased PTEN expression and fibroblast apoptosis induced by AGEs. Similarly, inhibition of PTEN expression alleviated increased fibroblast apoptosis induced by AGEs. In addition, the protein expressions of PI3K and phosphorylated Akt were reduced in fibroblasts exposed to AGEs.
We proposed that AGEs induced fibroblast apoptosis by regulating the miR-4429/PTEN/PI3K/Akt pathway in POP. Our results revealed a novel mechanism by which AGEs contributed to the molecular pathological alteration in POP.
盆腔器官脱垂（POP）是女性常见的退行性疾病。我们之前报道过，晚期糖基化终产物（AGEs），即非酶糖氧化反应产生的化合物，在人阴道壁中积累，并在POP的发病机制中损害成纤维细胞的功能。本研究调查了AGEs诱导人子宫骶韧带成纤维细胞凋亡及其潜在机制。
培养并鉴定人子宫骶韧带成纤维细胞。进行定量实时聚合酶链反应（qRT-PCR）分析以鉴定miR-4429、磷酸酶和张力蛋白同源物（PTEN）以及半胱天冬酶-3的表达。应用流式细胞术分析检测成纤维细胞的凋亡率。进行双荧光素酶报告基因检测以验证miR-4429与PTEN之间的关系。通过细胞转染实现miR-4429的过表达和PTEN的抑制。使用蛋白质印迹分析检测PTEN、磷酸肌醇3-激酶（PI3K）和蛋白激酶B（Akt）的蛋白水平。
AGEs在POP组和非POP组中均促进成纤维细胞凋亡。POP组成纤维细胞或经AGEs处理的成纤维细胞中PTEN的表达增加。证实miR-4429与PTEN信使核糖核酸（mRNA）相互作用，并且POP组成纤维细胞或经AGEs处理的成纤维细胞中miR-4429的表达水平降低。此外，miR-4429的过表达减轻了AGEs诱导的PTEN表达增加和成纤维细胞凋亡。同样，PTEN表达的抑制减轻了AGEs诱导的成纤维细胞凋亡增加。此外，暴露于AGEs的成纤维细胞中PI3K和磷酸化Akt的蛋白表达降低。
我们提出AGEs通过调节POP中的miR-4429/PTEN/PI3K/Akt途径诱导成纤维细胞凋亡。我们的结果揭示了AGEs促成POP分子病理改变的新机制。
