镁调节lncRNA TMPO-AS1表达水平抑制骨关节炎软骨细胞凋亡的机制研究

Osteoarthritis (OA) is a common degenerative joint disease, the pathogenesis of which is still unclear and chondrocyte apoptosis is closely related to OA. Applicant’s study found that low-level of magnesium is a risk factor of OA; magnesium can inhibit apoptosis of human OA chondrocyte, protect human OA chondrocyte and delay the degeneration of cartilage in rats OA model; in chondrocyte, magnesium can suppress the expression of lncRNA TMPO-AS1 and thioredoxin interacting protein (TXNIP), the expressions of which are positively related as encoded-non-coding gene coexpression network analysis shows; suppression of chondrocyte TMPO-AS1 expression can down-regulate TXNIP mRNA level. Literature reports that TXNIP can induce the apoptosis of multiple kinds of cells. We speculate that magnesium can suppress the expression of lncRNA TMPO-AS1 in chondrocyte, reduce the level of TXNIP, and then inhibit the apoptosis of OA chondrocyte. This project intends to confirm the effect of magnesium on apoptosis of chondrocyte and clarify that magnesium can inhibit apoptosis by affecting TXNIP level through regulating the expression of lncRNA TMPO-AS1 in chondrocyte, using overexpression transfection, siRNA interference, flow cytometry, and TUNEL method, in vitro(single layer and three-dimensional culture) and in vivo. It is aimed at revealing new perspectives of the pathogenesis of OA, exploring novel biological targets, and providing new ideas for the prevention and treatment of OA.

骨关节炎（OA）是一种常见关节退行性疾病，其发病机理尚不十分明确，软骨细胞凋亡与OA密切相关。申请人研究发现：低镁为OA患病危险因素；镁可抑制人OA软骨细胞凋亡、保护人OA软骨细胞、延缓大鼠OA模型软骨退变；镁可下调软骨细胞lncRNA TMPO-AS1和硫氧还蛋白互作蛋白（TXNIP）表达，且编码-非编码基因共表达网络分析显示二者表达呈正相关；抑制软骨细胞TMPO-AS1表达可降低TXNIP mRNA水平。结合文献报道TXNIP可诱导多种细胞凋亡，推测：镁可下调软骨细胞lncRNA TMPO-AS1表达，而后降低TXNIP水平，进而抑制OA软骨细胞凋亡。本项目拟利用过表达转染、siRNA干扰、流式细胞术、TUNEL染色和qRT-PCR等技术，在体外细胞（单层和三维培养）与活体动物两个层面证实以上假说。旨在从新的视角揭示OA发病机理，探索新的生物学靶点，为临床防治OA提供新思路。

骨关节炎（OA）是一种常见关节退行性疾病，其发病机理尚不十分明确。本课题探究了镁对软骨细胞mRNA和lncRNA表达谱的影响，研究了镁对软骨细胞 TXNIP 和lncRNA TMPO-AS1 表达水平的调控，研究了镁能否通过影响软骨细胞 TXNIP 表达影响软骨细胞。结果明确了镁对软骨细胞TXNIP和lncRNA TMPO-AS1表达水平的调控；证实了TMPO-AS1对TXNIP的正向调控作用，且TXNIP可促进软骨细胞MMP13的表达，加速OA建模的大鼠关节软骨的退变，促进OA进展。本课题进一步明确了镁对软骨细胞凋亡的抑制作用并不依赖TXNIP和lncRNA TMPO-AS1；发现镁可通过调节TXNIP影响软骨细胞自噬。为阐明骨关节炎的发病机制提供了新思路。