It is well established that microRNA (miRNA) expression profiles are altered in patients with polycystic ovary syndrome (PCOS). In addition, abnormal transforming growth factor beta (TGFB) signaling in granulosa cells is related to the pathological conditions of PCOS. However, the function of dysregulated miRNAs in PCOS is still unclear. In this study, we aimed to elucidate the roles of specific miRNAs in PCOS. We collected follicular fluid from 46 patients with PCOS and 32 healthy controls. Granulosa cells (GCs) were separated and the levels of six candidate miRNAs were determined by quantitative RT-PCR. The direct targets of three dysregulated miRNAs were predicted using bioinformatic tools and confirmed using a dual luciferase assay and immunoblotting. The biological function of three dysregulated miRNAs in primary GCs was determined using a cell proliferation assay and flow cytometry. We found that miR-423 expression was downregulated (P = 0.038), and the levels of miR-33b (P = 0.032) and miR-142 (P = 0.021) were upregulated in GCs from patients with PCOS, compared to controls. miR-423 directly repressed SMAD family member 7 (SMAD7) expression, while transforming growth factor beta receptor 1 (TGFBR1) was a direct target of both miR-33b and miR-142. An RNA oligonucleotide mixture containing miR-423 inhibitor, miR-33b mimic, and miR-142 mimic repressed TGFB signaling, promoted cell proliferation (P = 0.0098), repressed apoptosis (P = 0.027), and increased S phase cell numbers (P = 0.0036) in primary cultures of GCs, compared to the cells treated with a sequence scrambled control RNA oligonucleotide. This study unveiled the possible roles of three miRNAs in PCOS and might provide candidate biomarkers for PCOS diagnosis while in vivo functional studies, using transgenic or knockout mouse models, are expected to confirm the roles of dysregulated miRNAs in the pathogenesis of PCOS.

中文翻译：

---

颗粒细胞中靶向TGFBR1和SMAD7的miR-142，-33b和-423失调：在多囊卵巢综合征中的可能作用。

众所周知，患有多囊卵巢综合征（PCOS）的患者的microRNA（miRNA）表达谱发生了改变。另外，颗粒细胞中的异常转化生长因子β（TGFB）信号转导与PCOS的病理状况有关。但是，PCOS中miRNA失调的功能仍不清楚。在这项研究中，我们旨在阐明PCOS中特定miRNA的作用。我们收集了46例PCOS患者和32例健康对照的卵泡液。分离颗粒细胞（GC），并通过定量RT-PCR测定六个候选miRNA的水平。使用生物信息学工具预测了三个失调的miRNA的直接靶标，并使用双重荧光素酶测定法和免疫印迹法对其进行了确认。使用细胞增殖测定法和流式细胞仪确定了主要GC中三种失调的miRNA的生物学功能。我们发现，与对照组相比，PCOS患者的GC中miR-423的表达下调（P = 0.038），miR-33b（P = 0.032）和miR-142（P = 0.021）的水平上调。miR-423直接抑制SMAD家族成员7（SMAD7）的表达，而转化生长因子β受体1（TGFBR1）是miR-33b和miR-142的直接目标。包含miR-423抑制剂，miR-33b模拟物和miR-142模拟物的RNA寡核苷酸混合物可抑制TGFB信号传导，促进细胞增殖（P = 0.0098），抑制细胞凋亡（P = 0.027）和增加S期细胞数（P = 0.0036）在GC的原代培养中，与用序列加扰的对照RNA寡核苷酸处理的细胞相比。这项研究揭示了三种miRNA在PCOS中的可能作用，并可能为PCOS诊断提供候选生物标记，而使用转基因或基因敲除小鼠模型的体内功能研究有望证实失调的miRNA在PCOS发病机理中的作用。