PCOS大鼠血清中miR-200b及靶基因VEGF的表达及临床意义

Expression of MiR-200b and Target Gene VEGF in Serum of PCOS Rats and Its Clinical Significance

目的:研究miR-200b及靶基因血管内皮生长因子(VEGF)在多囊卵巢综合征(PCOS)大鼠血清中的表达水平,探讨miR-200b及VEGF在PCOS发病机制中的作用。方法:选取60只6周龄SD雌性大鼠,随机分为实验组、对照组和空白组,每组各20只。实验组给予来曲唑灌胃制备PCOS大鼠模型,观察大鼠动情周期及卵巢形态学变化。放射免疫法测定大鼠血清黄体生成激素(LH)、卵泡刺激素(FSH)、雌二醇(E_2)、孕酮(P)和睾酮(T)水平。采用实时荧光定量聚合酶链反应(real-time PCR)法检测miR-200b及VEGF的表达。结果:与对照组比较,实验组大鼠失去规律的动情周期,其卵巢体积增大,镜下呈现多囊样改变,血清T、LH水平明显升高,FSH、E2、P水平显著下降(均P<0.01)。real-time PCR实验结果显示miR-200b在PCOS大鼠模型血清中的表达显著降低(P<0.01),靶基因VEGF在PCOS大鼠模型血清中的表达显著升高(P<0.01)。结论:miR-200b在PCOS大鼠模型血清中低表达,可能通过调控其靶基因VEGF而在PCOS发病机制中起重要作用,推测miR-200b可成为诊断PCOS的生物学标志物,从而为PCOS的诊治提供新思路。

Objective:To study the effect of miR-200b on the expression of VEGF in PCOS rat model, and to explore the role of miR-200b and target gene VEGF in the pathogenesis of PCOS. Methods: Sixty female SD rats of six weeks age were randomly divided into three groups (20 rats for each group): experiment group and experiment control group,blank control group. Set up an animal model by using Letrozole. The estrus cycles changes and histologic changes in ovaries and serum hormone levels were examined. The miR-200b and VEGF in serum was detected by real-time quantitative PCR. Results: The estrus cycles of PCOS group become irregular, which indicated that the rats had no ovulation. Serum testosterone and LH levels were elevated, while FSH,progestone and estradiol levels were reduced (both P<0.01). Real-time-PCR results showed that the expression of miR-200b in the serum of PCOS rats decreased significantly (P<0.01). The expression of target gene VEGF in the serum of PCOS rats increased significantly (P<0.01). Conclusions: The level of miR-200b in serum of PCOS rats was reduced and it may play an important role in the development of PCOS by regulating its target gene VEGF. We hypothesized that circulating miR-200b may be a new non-invasive diagnostic marker for PCOS diagnosis.