MicroRNA-145靶向调控Smad3和Smad5影响胚胎着床的研究

It has been found that the highly expressed miR-145 may related to repeated implantation failure (RIF). Our preliminary data also showed that miR-145 was down-regulated during implantation window. Meanwhile, we found that miR-145 may target on Smad3 and Smad5, two key factors in TGF-β superfamily signaling pathways which were also proved to play important roles in embryo implantation. Thus, we hypothesize that miR-145 may affect embryo implantation via regulating its target genes, Smad3 and Smad5. This program plans to confirm this hypothesis.through: verifying the regulation of miR-145 on Smad3 and Smad5 in endometrium and endometrial cells, confirming that miR-145 affect embryo implantation by using mouse model of implantation and intrauterine transfection, and further clarifying that miR-145 plays its role via regulating Smad3 and Smad5 by silencing or recovering its target genes. It is hopefully to provide new theories for the etiology of implantation dysfunction and repeated implantation failure, and train of thoughts in finding new assisted reproductive therapy based on miRNA.

研究发现，miR-145的高表达可能和反复着床失败相关，我们的前期实验亦发现miR-145在着床窗期表达降低。同时，我们发现miR-145可能靶向调控TGF-β超家族信号通路中的两个关键因子Smad3和Smad5。而TGF-β超家族信号通路亦被证实在胚胎着床中起关键作用。据此，我们作出miR-145可能通过转录后调节靶基因Smad3和Smad5影响胚胎着床的假设。本项目拟通过：1. 证实子宫内膜组织和细胞中miR-145对Smad3和Smad5的调控作用；2. 用小鼠着床模型，宫腔转染等技术证实miR-145可以影响胚胎着床；3. 用RNA干扰和基因回补进一步证实miR-145通过调控Smad3和Smad5发挥效应，三个方面来证明该假设。本项目的研究有望为着床障碍及习惯性流产等疾病的病因学提供新的理论依据，以及为寻找新的基于miRNA的辅助生殖治疗方法提供新的思路。

根据文献和我们的前期数据，发现miR-145可能靶向调控TGF-β超家族信号通路中的两个关键因子Smad3和Smad5来影响胚胎着床。本项目的主要研究内容包括：1. 证实子宫内膜组织和细胞中miR-145对Smad3和Smad5的调控作用；2. 用小鼠着床模型，宫腔转染等技术证实miR-145可以影响胚胎着床；3. 用RNA干扰和基因回补进一步证实miR-145通过调控Smad3和Smad5发挥效应。研究发现，miRNA-145和Smad3、Smad5在小鼠子宫内膜的表达负相关；miRNA-145可以降低小鼠子宫内膜中Smad3和Smad5的表达；宫腔内转染miRNA-145可以明显降低小鼠胚胎着床的数量；体外细胞实验证实过表达miRNA-145对子宫内膜基质细胞蜕膜化有不利影响。过表达miRNA-145的子宫内膜上皮细胞对滋养细胞的粘附力降低，TGF-β可以逆转这一现象。实验结果说明Smad3和Smad5为miRNA-145的靶基因，miRNA-145可以通过降低Smad3和Smad5的表达影响子宫内膜上皮细胞对滋养细胞的粘附作用，并可能通过这一途径影响胚胎着床。本项目为复发性流产的病因学提供了新的理论依据，有望为寻找新的基于miRNA的辅助生殖治疗方法提供新的思路。