孕激素诱导的microRNA对子宫内膜上皮细胞增殖的抑制作用研究

One of the main physiological roles of progesterone is to antagonize the effect of estrogen's promoting proliferation of endometrial epithelial cells. Recent studies have indicated that reproductive hormones can regulate the expression of some target genes in post-transcriptional level. MicroRNAs are important post-transcriptional regulators which are involved in many physiological and pathological processes. We speculate that there should be progesterone-induced microRNAs in endometrial epithelial cells, which mediate the effect of progesterone through inhibiting the expression of some positive regulators of cell cycle. In this project, total RNAs have been respectively extracted from endometrial epithelial cells of ovariectomized mice which were treated by only estrogen or by both estrogen and progesterone. Using microRNA high-throughput sequencing combined with in silico prediction, we want to find progesterone-induced microRNAs whose target genes are positive regulators of the cell cycle in endometrial epithelial cells. Furthermore，we will choose 2 or 3 representative microRNAs to study weather and how they are involved in the inhibitory effect of progesterone on the proliferation of endometrial epithelial cells through inhibiting the expression of positive regulators of the cell cycle. This project will be helpful for further exploring the molecular mechanism of progesterone's effect and provide new ideas for diagnosis and treatment of some diseases in reproductive system.

孕激素主要生理作用之一是拮抗雌激素对子宫内膜上皮细胞的促增殖作用。近年研究显示生殖相关激素可通过转录后水平调控诸多靶基因表达，而microRNA是重要的基因转录后调控因子，参与了许多生理病理过程。我们推测在子宫内膜上皮细胞中存在孕激素诱导的microRNA，通过抑制细胞周期正调节因子表达，拮抗雌激素对子宫内膜上皮细胞的促增殖作用。本项目拟从分离的雌激素或雌、孕激素联合处理的去卵巢小鼠的子宫内膜上皮细胞中提取总RNA，采用microRNA高通量测序结合in silico预测方法确定孕激素诱导的，且靶基因产物为细胞周期正调节因子的microRNA；从中选出有代表性的microRNA,用细胞和分子生物学技术研究其通过对靶基因转录后抑制介导孕激素对子宫内膜上皮细胞增殖的抑制作用，从一个新的视角进一步揭示孕激素抑制子宫内膜上皮细胞增殖的分子机制，也为生殖系统相关疾病的诊断和治疗提供新的思路。

本项目按原定计划进展顺利，已完成项目计划书的既定研究目标。我们利用高通量测序技术，筛选出了子宫内膜上皮细胞中孕激素诱导的microRNA，通过进一步的靶基因预测及功能分析，选择miR-145a，miR-143，miR-1a，miR-133a和miR-152进行了重点研究。研究结果表明，孕激素可以作用于子宫内膜上皮细胞的孕激素受体PRA，诱导miR-145a和miR-143的表达，通过作用于孕激素受体PRB诱导miR-1a，miR-133a和miR-152的表达。其中miR-145a，miR-143，miR-1a与miR-133a可以通过抑制cyclin D2，抑制子宫内膜上皮细胞的增殖；miR-152可以通过抑制WNT-1，抑制子宫内膜上皮细胞的增殖。另外，miR-145a，miR-143与miR-152对人子宫内膜癌细胞也具有增殖抑制作用。本项目研究证明在子宫内膜上皮细胞中孕激素通过诱导某些特定microRNA表达抑制某些细胞周期正调控因子，从而实现对子宫内膜上皮细胞增殖的抑制作用，这是孕激素拮抗雌激素作用，抑制子宫内膜上皮细胞增殖的重要分子机制之一。该研究成果不仅对阐明雌、孕激素调控子宫内膜形态功能的分子机制具有重要意义，并且也为进一步研究因雌、孕激素调控异常所致子宫内膜增生过长及子宫内膜癌的分子病理机制，探索新的诊断及治疗措施提供了新的线索。研究结果已发表多篇SCI及核心期刊论文，并多次在国内和国际会议上交流。先后有两名博士研究生和三名硕士研究生参与该项目的研究工作，这对研究生的培养也起到了积极作用。