中文摘要：

目的MicroRNA（miR）-19b是通过芯片筛选出与心脏发育高度相关的-种miRNA，本研究旨在研究miR-19b通过Wnt／β-catenin信号通路对P19细胞的影响。方法生物信息学软件预测miR-19b潜在靶基因；双荧光素酶报告基因验证miR-19b是否作用于Wnt的预测靶点；脂质体2000转染miR-19b过表达质粒与空载质粒进入P19细胞；CCK-8法检测细胞增殖活性；磷脂酰丝氨酸外翻分析检测细胞凋亡；Westernblot检测Wntl表达水平；实时定量-聚合酶链反应（PCR）检测miRNA-19b表达水平。结果TargetScan5．1软件预测Wntl为miR-19b在P19细胞中发挥作用的潜在靶点，双荧光素酶报告基因进行了验证，miR-19b过表达显著降低了靶基因Wnt的活性（P〈0．05）；miR-19b过表达降低了wnt信号通路中Wntl和B—catenin的表达水平，两者水平表达一致，于第2天至第10天均有统计学差异（P均〈0．05）。与空载对照组相比，miRNA-19b可促进P19细胞的增殖（各时间点P〈0．05），并且抑制其凋亡（P〈0．05）。结论miR-19b可能通过Wnt／β-catenin信号通路促进P19细胞的增殖，抑制凋亡，为其以后用于心脏发育的进一步研究奠定基础。

英文摘要：

Objective Previously study indicated that the microRNA （miR）-19b is highly correlated with heart development by chip screening. This study aims to explore the function of miR-19b overexpression on PI9 cells through Wnt,/beta-catenin signaling pathway. Methods Potential target gene of miR-19b was predicted by bioinforma- tics software such as TargetScan on line; Dual luciferase reporter gene system was applied to test whether the the pre- dict target could bind with miR-19b and transfeet miR-19b overexpression plasmid or vector into P19 cells by lipo 2000 and stable cell lines was selected by Blasticidin;CCK-8 assay was adopted to detect cell proliferation activityed and cell apoptosis was detected with Phosphatidylserine eversion analysis. Wntl protein expression level and the miR-19b RNA expression levels were detected by Western blot and real-time quantitative PCR. Results Wntl was the potential tar- gets of miR-19b in P19 cells by TargetSean 5.1 software,which was verified by dual luciferase reporter gene; The re- suits of luciferase reporter gene system demonstrats that miR-19b ihibited the activity of Wnt not the Wnt mutation （ P 〈 0.05 ） ; Overexpression of miR-19b reduced Wntl and beta-catenin expression level in the Wnt signaling pathway, re- spectively（ at most point P 〈0.05 ）. Moreover, miR-19b could promote the proliferation of P19 cell（ at most point P 〈 0.05）, and inhibit its apoptosis（P 〈 0. 05 ）. Conclusions MiR-19b promotes the P19 cell proliferation,inhibits its apoptosis. In addition, miR-19b is indirectly interacted with target gene Wntl and affects P19 cell lines through Wnt/ beta-catenin signaling pathway. This study shows a new insight of heart development and more efforts are needed on ex- ploring the deep function of heart diseses.