miR-155有助于骨髓间充质干细胞成软骨分化

miR-155 is conductive to chondrogenic differentiation of bone marrow mesenchymal stem cells

背景:近年发现,mi RNA是能够对基因表达产生影响的一种新型调控子,mi RNA有助于多能干细胞分化增殖以及自我更新。目的:探讨mi R-155对大鼠骨髓间充质干细胞成软骨分化的调控机制。方法:12周龄健康SD大鼠60只,随机分为研究组与对照组,每组30只。于麻醉状态下将大鼠处死,获取下肢骨髓,进行骨髓间充质干细胞分离、培养,研究组给予mi R-155基因模拟物转染,对照组给予阴性对照序列转染,经成软骨诱导分化后进行RT-PCR检测Sox9、CollagenⅡ、Aggrecan、Collagen X基因的表达,Western blot检测Sox9、Runx2蛋白的表达。结果与结论:研究组Sox9、CollagenⅡ、Aggrecan基因表达高于对照组,Collagen X基因表达低于对照组,差异均有显著性意义(P<0.05)。研究组Sox9蛋白表达高于对照组,Runx2蛋白表达低于对照组,差异均有显著性意义(P<0.05)。结果表明mi R-155不仅有助于骨髓间充质干细胞成软骨分化,而且可以抑制骨髓间充质干细胞成软骨分化呈肥大趋势发展。

BACKGROUND：It is discovered recently that miRNA is a new regulator that is able to have an impact on gene expression and miRNA contributes to proliferation, differentiation and self-renewal of pluripotent stem cels. OBJECTIVE：To investigate the mechanism by which miR-155 regulates chondrogenic differentiation of bone marrow mesenchymal stem cels. METHODS： Sixty healthy Sprague-Dawley aged 12 weeks were randomized into study group and control group, with 30 in each group. Under anesthesia, rats were sacrificed to harvest bone marrow of the lower limbs. Then bone marrow mesenchymal stem cels were isolated, cultured, and transfected with miR-155 mimics in the study group and a negative control sequence in the control group. After chondrogenic induction, RT-PCR was used to detect the expressions of Sox9, Colagen II, Aggrecan and Colagen X gene, and western blot assay to detect the expression of Sox9 and Runx2 proteins. RESULTS AND CONCLUSION：Compared with the control group, the mRNA expressions of Sox9, Colagen II and Aggrecan were higher, but the mRNA expression of Colagen X was lower in the study group （P 〈 0.05）; the protein expression of Sox9 was higher, but the protein expression of Runx2 was lower in the study group （P 〈 0.05）. These findings indicate that miR-155 promotes the chondrogenic differentiation of bone marrow mesenchymal stem cels and moreover, it can suppress the hypertrophy trend of bone marrow mesenchymal stem cels differentiating into chondrocytes.