不同力学微环境下软骨退变相关lncRNA和Sp1协同调控关节软骨退变的机制研究

In our previous investigation, it is confirmed that articular cartilage degradation is closely related to the maintenance of chondrocytes’ structure and function in mechanical microenvironment, and the key point is the synergistic effect of epigenetic, transcriptional and post-transcriptional regulation. LncRNAs associated with articular cartilage degeneration have been selected and are involved in the regulation of articular cartilage degeneration synergistically with Sp1. In this study, we further investigate the mechanism of the combinatorial regulation of cartilage degeneration related lncRNAs and Sp1 in abnormal mechanical microenvironment both in vivo and in vitro, by ordered combinatorial regulation of the epigenetic and transcription focused on lncRNAs. Firstly, we will observe the expression kinetics of lncRNAs, Sp1 and specific genes of cartilage in different mechanical microenvironment in vitro to figure out regulative rules. Next, we will further study the lncRNAs which are related to Sp1 and specific genes of cartilage in the regulation rules of expression kinetics among the thirteen lncRNAs selected by microarray and bioinformatic analysis, to figure out the mechanism of the synergistic regulation with Sp1. Lastly, we will clarify the effect of intervention of these factors on depressing cartilage degradation induced by abnormal mechanical stress in a murine model of knee joint trauma following non-invasive controlled injurious compression in vivo. It is significant to provide new foundation for control of cartilage degradation caused by biomechanics factor.

关节软骨退变与力学微环境中软骨细胞结构和功能维持密切相关，核心是表观遗传、转录和转录后的协同调控，我们前期研究证实了这点而且筛选出的软骨退变相关lncRNA可能与Sp1共同调节关节软骨的退变。本研究在此基础上以lncRNA为中心的表观遗传、转录的协同调控为切入点，通过体内外实验进一步研究软骨退变相关lncRNA和Sp1在异常力学微环境下协同调控软骨退变的作用机制：首先，体外观察不同力学微环境下关节软骨细胞中lncRNA、Sp1和软骨特征性指标的表达动力学规律；然后，进一步研究芯片结果和信息学分析筛选的13个lncRNA中表达动力学规律与Sp1和软骨特征性指标相关的lncRNA，及其与Sp1的协同调控机制；最后应用膝关节机械压力软骨损伤动物模型揭示干预lncRNA和Sp1的协同调控在阻抑异常应力导致的软骨退变中的作用，为解决生物力学因素引起的软骨退变这一难题提供新的理论基础，具有重要的意义。

关节软骨退变主要表现为关节软骨稳态被破坏，在此过程中，相应关键基因在转录水平和转录后水平受到错综复杂的调控。在本项目资助期间，我们研究证实了非编码RNAs（non-coding RNAs，ncRNAs）在成软骨分化及软骨退变过程中起到重要作用，并通过lncRNA芯片测序技术成功筛选出的软骨退变相关lncRNA。其中有3007个上调，2136个下调。然后我们进一步通过进一步研究芯片结果和信息学分析，筛选了13个lncRNA，其表达动力学规律与Sp1和软骨特征性指标相关，进一步研究发现其与Sp1协同调节关节软骨退变。我们对关节退变过程中软骨稳态被破坏的机制进行了进一步的探讨，证实了非编码RNAs在成软骨分化及软骨退变过程中起到重要作用。我们发现miR-193 b调控抑制成软骨分化；miR-455-3p 调控诱导成软骨分化。另外我们还发现了lncRNA UFC1在内源性竞争RNA网络中充当分子海绵的作用，延缓miR-34a对软骨退变的作用。以上研究证实了ncRNAs之间、ncRNAs与转录因子之间在软骨退变过程中起到协同作用。