过表达微小RNA-21对c-Kit+心脏干细胞增殖、迁移及分化的影响

摘要

AIM:To explore the effect of microRNA (miR)-21 on proliferation, migration and differentiation abilities of c-Kit+ cardiac stem cells (CSCs). METHODS:c-Kit+ CSCs were cultured and selected by the methods of en-zyme digestion and magnetic bead separation. miR-21 mimics (50 nmol/L) and mimics negative control ( MNC) were transfected into c-Kit+CSCs with Lipofectamine?2000. The cells was divided into 3 groups:control group:c-Kit+ CSCs without any pretreatment; MNC group:the cells were transfected with MNC for 48 h; mimics group:the cells were trans-fected with miR-21 mimics for 48 h. qPCR was used to assess the expression of miR-21 in each group. CCK-8 and EdU as-says were used to determine the cell proliferation. qPCR and immunofluorescence were used to detect the differentiation in each group. Scratch assay was adopted to explore the migration ability of the cells. RESULTS:The expression of c-Kit in the c-Kit+ CSCs were 90.8%, with 0.6% of CD45 and 0.5% of CD34. A significant increase in miR-21 expression was observed when the cells were transfected with miR-21 mimics for 48 h ( P<0.05). CCK-8 and EdU assays showed that miR-21 significantly increased cell proliferation as compared with MNC group and control group (P<0.05). No difference in the expression of Nkx2.5, CD31 and α-SMA at mRNA and protein levels was observed, and no difference of the migra-tion ability in 3 groups of the c-Kit+ CSCs was found. CONCLUSION:Over-expression of miR-21 significantly promotes the proliferation of c-Kit+ CSCs, without any effect on the cell migration and differentiation.%目的:探讨转染微小RNA-21(microRNA-21,miR-21)对c-Kit+心脏干细胞增殖、分化和迁移的影响.方法:采用酶消化法结合免疫磁珠分选法培养c-Kit+心脏干细胞,以Lipofectamine?2000为载体将miR-21模拟物(mimics)和其阴性对照(mimics negative control,MNC)分别转染至 c-Kit+心脏干细胞.实验分为正常对照(control)组(正常培养的心脏干细胞)、MNC组(转染MNC 48h的细胞)和mimics组(转染miR-21 mimics 48 h的细胞). qPCR检测各组细胞miR-21的表达情况,以CCK-8法和EdU法检测细胞增殖状态,qPCR及免疫荧光检测细胞分化情况,划痕实验观察细胞迁移能力.结果:成功获取c-Kit+心脏干细胞,经流式细胞术鉴定其高表达 c-Kit (90.8%),低表达CD45(0.6% )及CD34(0.5%);与control组相比,mimics组中 miR-21表达量显著增高(P<0.05), MNC组中miR-21表达量与control组无明显差异. CCK-8和EdU实验结果发现与control组比较,mimics组中细胞增殖能力明显增加(P<0.05),MNC组中细胞增殖能力无明显变化;免疫荧光及qPCR结果表明3组心肌细胞谱系标志物Nkx2.5、CD31和α-平滑肌肌动蛋白水平无明显差异;细胞划痕实验结果发现,3组间细胞迁移能力无明显不同.结论:过表达miR-21可显著促进c-Kit+心脏干细胞的增殖能力,但对细胞迁移及分化能力无明显影响.