miR-30c/Shh信号通路在PCBs暴露致子代心脏发育缺陷中的机制

MiR-30c was a significantly up-regulated miRNA,which was characterized not only in the myocardial tissues of aborted embryos of fetal ventricular septal defect with the elevated level of polychlorinated biphenyls (PCBs), but also in zebrafish embryonic tissue of the cardiac anomalies induced by embryonic exposure to PCBs by high-throughput screening techniques. In the previous report,we found that overexpression of miR-30c in zebrafish embryos induced cardiac malformation; Gli2 gene was discovered and confirmed as its target gene by both bioinformatics analysis and luciferase report gene.Our further studies revealed that Shh signaling pathway could not play a role，which the Gli2 gene was downregulated both in zebrafish embryos tissue of the cardiac anomalies induced by embryonic exposure to PCBs and the differentiation of P19 cells to cardiac myocytes which were treated with PCBs. All of these results provided evidence that miR-30c/Shh signaling pathway might play an important role in the cardiac anomalies induced by embryonic exposure to PCBs. Based on these data, we will further investigate the roles and mechanisms of miR-30c/Shh signaling pathway on the cardiac anomalies induced by embryonic exposure to PCBs not only using gene overexpression and gene silencing technology, but also using the platform of P19 cell culture and in vivo studies of zebrafish in this study. We will dissect the roles and mechanisms of miR-30c/Shh signaling pathway on the cardiac anomalies induced by embryonic exposure to PCBs.This study is of certain creativity and will provide a new avenue for the prevention and treatment of fetal congenital heart disease during pregnancy in the future.

miR-30c是我们应用高通量技术筛选室间隔缺损流产胚胎的心肌组织[多氯联苯（PCBs）含量明显升高]及PCBs暴露致斑马鱼胚胎心脏发育畸形的胚胎组织，发现的一条表达均显著上调的miRNA。前期发现：miR-30c过表达可致斑马鱼出现心脏畸形的表型, 生物信息学分析及荧光素酶报告基因发现并证实Gli2是其靶基因,PCBs暴露时斑马鱼的胚胎组织及P19细胞向心肌细胞分化过程中Shh信号通路均不能发挥效应（Gli2表达下调），提示miR-30c/Shh信号通路与PCBs暴露致子代心脏发育缺陷有关。本研究拟：应用基因过表达及基因沉默技术，利用P19细胞培养及斑马鱼活体研究平台，阐明miR-30c/Shh信号通路在PCBs暴露致子代心脏发育缺陷中的作用与机制。本研究未见报道，有源头创新性，将阐明胚胎期PCBs暴露致子代心脏发育缺陷的机制，为先天性心脏病在妊娠期的早期防治提供新的理论依据。

miR-30c是我们应用高通量技术筛选室间隔缺损流产胚胎的心肌组织[多氯联苯（PCBs）含量明显升高]及PCBs暴露致斑马鱼胚胎心脏发育畸形的胚胎组织，发现的一条表达均显著上调的miRNA。前期发现：miR-30c过表达可致斑马鱼出现心脏畸形的表型, 生物信息学分析及荧光素酶报告基因发现并证实Gli2是其靶基因,PCBs暴露时斑马鱼的胚胎组织及P19细胞向心肌细胞分化过程中Shh信号通路均不能发挥效应（Gli2表达下调），提示miR-30c/Shh信号通路与PCBs暴露致子代心脏发育缺陷有关。通过本课题的研究，我们发现：过表达miR-30c可抑制细胞的增殖、促进细胞凋亡、显著抑制P19细胞向心肌细胞方向的分化；利用斑马鱼活体研究平台，miR-30c过表达可致斑马鱼出现心脏畸形的表型，该研究为阐明胚胎期PCBs暴露致子代心脏发育缺陷的机制提供了一定线索，为先天性心脏病在妊娠期的早期防治提供新的理论依据。