Reproductive Medical Center, Qinghai Provincial People's Hospital, No. 2, Gonghe Road, Xining, 810007, Qinghai, China.
Department of General Surgery, Qinghai Provincial People's Hospital, Xining, 810007, Qinghai, China.
J Ovarian Res. 2020 Feb 5;13(1):13. doi: 10.1186/s13048-020-0611-4.
We elucidated the role of specific MicroRNAs (miRNAs) in the development of polycystic ovary syndrome (PCOS) and explained the changes in the proliferation of granulosa cells. Excised ovarian cortex specimens were collected for miRNA profiling analysis (n = 20 PCOS females and 5 non-PCOS females). Insulin-treated ovarian granulosa cells isolated from mice were used for mechanical studies.
High miR-140 expression was observed in PCOS samples and insulin-treated granulosa cells compared to that in non-PCOS and unstimulated cells, respectively. However, the Ras-related protein Rap-2a precursor (RAP2A) was downregulated in in PCOS. MTT assay and EdU staining showed that an miR-140 inhibitor attenuated viability in insulin-treated granulosa cells; cell viability increased with miR-140 overexpression. Reduced expression of miR-140 and the expression of the miR-140 mimic resulted in marked cell apoptosis, as evidenced by the results of PI flow cytometry and Annexin V-FITC; miR-140 overexpression results in downregulated RAP2A expression, and the miR-140 mimic directly bound to the RAP2A 3'-UTR, causing increase in RAP2A levels in insulin-treated granulosa cells; RNA-mediated silencing of RAP2A in insulin-treated granulosa cells restored cell proliferation and apoptosis to normal levels. Phosphorylated AKT was found to be negatively regulated through cross-talk between miR-140 and RAP2A.
In conclusion, PCOS ovarian cortex specimens and insulin-treated granulosa cells showed elevated expression of miR-140, which could lead to increased proliferation and reduced apoptosis of cells by targeting RAP2A. This study may pave the way for future research on the properties of granulosa cells in PCOS.
我们阐明了特定 MicroRNAs（miRNAs）在多囊卵巢综合征（PCOS）发展中的作用，并解释了颗粒细胞增殖的变化。切除卵巢皮质标本进行 miRNA 谱分析（n=20 例 PCOS 女性和 5 例非 PCOS 女性）。从小鼠中分离出胰岛素处理的卵巢颗粒细胞用于机械研究。
与非 PCOS 和未刺激细胞相比，PCOS 样本和胰岛素处理的颗粒细胞中 miR-140 表达较高，而 Ras 相关蛋白 Rap-2a 前体（RAP2A）在 PCOS 中下调。MTT 测定和 EdU 染色显示，miR-140 抑制剂减弱了胰岛素处理的颗粒细胞中的活力；miR-140 过表达可增加细胞活力。miR-140 表达减少和 miR-140 模拟物的表达导致明显的细胞凋亡，PI 流式细胞术和 Annexin V-FITC 的结果证明了这一点；miR-140 过表达导致 RAP2A 表达下调，miR-140 模拟物直接结合到 RAP2A 3'-UTR，导致胰岛素处理的颗粒细胞中 RAP2A 水平增加；胰岛素处理的颗粒细胞中 RAP2A 的 RNA 介导沉默将细胞增殖和凋亡恢复到正常水平。发现磷酸化 AKT 通过 miR-140 和 RAP2A 之间的串扰受到负调控。
总之，PCOS 卵巢皮质标本和胰岛素处理的颗粒细胞中 miR-140 表达升高，通过靶向 RAP2A 可导致细胞增殖增加和凋亡减少。这项研究可能为未来研究 PCOS 中颗粒细胞的特性铺平道路。
