miR-92a调控靶基因BMP7诱导人脂肪源性干细胞成软骨分化的研究

The regeneration of tissue engineered cartilage degeneration mainly due to chondrocyte differentiation that is a great trouble for its clinical application.Based on preliminary research we found that miR-92a was selectively expression during early stage of chondrogenesis in human adipose-derived stem cells (hADSCs).Bioinformatics indicated that miR-92a was targeted to BMP7, a cartilage master transcription factor closely related to chondrocyte development. In this study, we focus on the mechanism of hADSCs chondrogenesis by regulation of miR-92a by targeting gene BMP7 to improve chondrogenesis at transcriptional and post-transcriptional level.In vitro and vivo cell culture and miR-92a gene knockout mice,observed BMP7, SOX9, type II and type X collagen, aggrecan disintegrin metal protease 4 and MMP1 and MMP13 expression kinetics in hADSCs's chondrogenic differentiation, and cell proliferation, differentiation and growth rule in BMP7 induced miR-92a gene knockout mice.to clarify the stability of the mechanism of differentiation in hADSCs's chondrogenic differentiation through miR-92a and BMP7. This provide fundamental basis for the control and improvement during chondrogenesis of seed cells in tissue engineering cartilage.

组织工程化软骨的再生较早发生退变主要源于软骨细胞分化问题，这个问题仍掣肘其向临床应用转化。我们的研究已经证实miRNA能调节间充质干细胞的成软骨分化，分化过程中筛选出差异性表达的miRNA-92a，生物信息学软件预测显示BMP7（诱导细胞分化成软骨的成熟因子）是其预测靶基因。为阐明miR-92a调控靶基因BMP7的作用机制，本研究的基本思路是：以miR-92a作为切入点，在转录后水平和转录水平研究hADSCs分化为成软骨细胞过程中其对靶基因BMP7的作用特点。通过体外细胞培养诱导及miR-92a基因敲除小鼠体内实验，观察miR-92a上调或下调靶基因BMP7抑制或促进hADSCs向软骨方向诱导分化的作用规律，阐明miR-92a如何调控靶基因BMP7诱导hADSCs成软骨分化过程中的作用机制，研究成果对客观评价成软骨细胞分化功能的维持提供一定的理论基础。

组织工程化软骨的再生较早发生退变主要源于软骨细胞分化问题，这个问题仍掣肘其向临床应用转化。我们的研究已经证实miRNA能调节间充质干细胞的成软骨分化，分化过程中筛选出差异性表达的miRNA-92a，生物信息学预测分析发现去乙酰化酶HDAC2、金属基质蛋白酶ADAMTS-4/5为miR-92a-3p的靶基因，且HDAC2属于表观遗传学范畴，与软骨的退变直接相关；ADAMTS-4/5参与软骨基质的降解，加速骨性关节炎的发生发展。以miR-92a作为切入点，在转录后水平和转录水平研究间充质干细胞成软骨分化过程中及软骨发育的调控以及原代软骨细胞方面的表观调控，阐明miR-92a如何调控靶基因HDAC2、ADAMTS-4/5，从而影响软骨的发育与退变，研究成果对客观评价成软骨细胞分化功能的维持提供一定的理论基础。