背景:microRNA-26b(miR-26b)对干细胞的多种功能具有重要的调节作用,但其对人脱落乳牙牙髓干细胞和人脐带间充质干细胞生物学特性的影响尚不清楚. 目的:探讨miR-26b对人脱落乳牙牙髓干细胞和人脐带间充质干细胞增殖、迁移和成骨分化的影响. 方法:培养及鉴定人脱落乳牙牙髓干细胞和人脐带间充质干细胞;用miR-26 mimics(实验组)和miRNAs mimics对照(对照组)转染2种细胞,构建过表达模型用于后续实验.CCK-8法检测过表达miR-26b细胞的增殖能力;Transwell和划痕实验分析过表达miR-26b细胞的迁移能力;RT-qPCR法检测过表达miR-26b细胞成骨诱导后成骨标志物的表达. 结果与结论:①转染miR-26b模拟物可提高2种细胞中miR-26b表达量,促进人脱落乳牙牙髓干细胞增殖,对人脐带间充质干细胞的扩增无明显影响;②相较于对照组,2种细胞过表达miR-26b后迁移能力增强;③miR-26b在2种细胞成骨分化过程中表达水平降低;④相较于对照组,2种细胞过表达miR-26b后,成骨相关基因骨钙素、骨桥素、碱性磷酸酶、Ⅰ型胶原蛋白mRNA水平均下调.结果表明,过表达miR-26b能促进人脱落乳牙牙髓干细胞增殖、迁移,抑制其成骨分化;也促进人脐带间充质干细胞迁移,抑制其成骨分化,但对其增殖无明显影响.
BACKGROUND:microRNA-26b(miR-26b)plays an important regulatory role in a variety of stem cell functions,but its effects on the biological properties of stem cells from human exfoliated deciduous teeth and human umbilical cord mesenchymal stem cells are unknown. OBJECTIVE:To investigate the effects of miR-26b on the proliferation,migration and osteogenic differentiation of stem cells from human exfoliated deciduous teeth and human umbilical cord mesenchymal stem cells. METHODS:Stem cells from human exfoliated deciduous teeth and human umbilical cord mesenchymal stem cells were cultured and identified.miR-26 mimics(experimental group)and miRNAs mimics control(control group)were used to transfect above mentioned two kinds of cells and construct overexpressed models for subsequent experiments.CCK-8 assay was applied to detect the proliferation ability of overexpressed miR-26b cells.Transwell and scratch assay were employed to analyze the migration ability of overexpressed miR-26b cells.RT-qPCR was utilized to examine the expression of osteogenic markers after osteogenic induction of overexpressed miR-26b cells. RESULTS AND CONCLUSION:(1)Transfection of miR-26b mimics increased miR-26b expression in the two kinds of cells and promoted the proliferation of stem cells from human exfoliated deciduous teeth,with no significant effect on the amplification of human umbilical cord mesenchymal stem cells.(2)Compared with the control group,the migration ability was enhanced after two types of cells overexpressing miR-26b.(3)miR-26b expression decreased during osteogenic differentiation of the two kinds of cells.(4)Compared with the control group,the levels of osteogenesis-related genes osteocalcin,osteopontin,alkaline phosphatase,and human type I collagen mRNA were downregulated after overexpression of miR-26b in the two kinds of cells.The results showed that overexpression of miR-26b promoted the proliferation and migration of stem cells from human exfoliated deciduous teeth and inhibited their osteogenic differentiation;it promoted the migration of human umbilical cord mesenchymal stem cells and inhibited their osteogenic differentiation,but had no significant effects on their proliferation.