中文摘要：

骨关节炎（osteoarthritis,OA）是一种严重危害人类健康的慢性退行性关节病变,而免疫相关反应是影响OA进程的重要因素。转化生长因子β活化激酶1（transforming growth factor-βactivated kinase 1,TAK1）作为固有免疫及适应性免疫反应中的关键激酶,在多种细胞类型中介导NF-κB、JNK及p38 MAPK等免疫相关信号通路的活化。另有研究表明,TAK1通过调控MAPK及BMP信号通路,对软骨的形态发生、生长及维持起着关键作用,而TAK1对于软骨细胞的细胞周期、增殖及死亡的影响则鲜有报道。本研究拟构建TAK1过表达腺病毒,用其感染软骨细胞,观察TAK1的过表达对软骨细胞的周期、增殖及死亡有何影响,并明确其对细胞内OA相关基因的调控。Western印迹实验及荧光显微镜下观察结果证实,TAK1过表达腺病毒构建成功,可在软骨细胞中实现高效表达,并可引起软骨细胞的显著死亡。流式细胞术结果显示,TAK1可使软骨细胞周期阻滞于G2期,而TAK1的小分子抑制剂5Z-7-Oxozeaenol则可使G2期细胞比例显著减少。CCK-8及乳酸脱氢酶检测结果表明,TAK1可抑制软骨细胞的增殖,并引发其发生坏死。实时荧光定量PCR结果表明,TAK1可诱导软骨细胞中分解代谢相关基因Adamts1及IL-6的表达上调,并抑制合成代谢相关基因Sox9及Col2a1的表达。以上结果证实,TAK1的过表达可引发软骨细胞出现细胞周期阻滞、增殖减缓、坏死以及分解与合成代谢平衡失调等OA样病变,因此很可能是OA临床治疗中的潜在作用靶点。本研究为进一步揭示OA进程中软骨退化的分子机制提供了线索。

英文摘要：

Osteoarthritis（ OA） is a chronic degenerative joint disease that severely impairs human health,and immune-related response is an important factor that affects OA progression. Transforming growth factor-beta activated kinase 1（ TAK1） is a key kinase in innate and adaptive immune responses,and it mediates the activation of immune-related signaling pathways such as NF-κB,JNK and p38 MAPK pathway in a variety of cell types. Previous studies have shown that TAK1 plays an essential role in morphogenesis, growth, and maintenance of cartilage via modulating MAPK and BMP signaling pathways,however the impact of TAK1 on the cell cycle,proliferation and death of chondrocytes remainselusive. In this study,by construction of TAK1 overexpressing adenovirus then infect chondrocytes,we aim to investigate the impact of TAK1 on cell cycle,proliferation and cell death,and its regulation on OA-related genes expressing in chondrocytes. Western blot and fluorescence microscopy results demonstrated successful construction of TAK1 overexpression adenovirus,which could be efficiently expressed in chondrocytes,and induced significant cell death. Flow cytometry results showed that TAK1 induced G2phase arrest of chondrocytes,while its small molecular inhibitor 5Z-7-Oxozeaenol significantly reduced the proportion of cells in G2 phase. CCK-8 and LDH assay results revealed that TAK1 inhibited chondrocytes proliferation and induced necrotic cell death. Real-time PCR results suggested that TAK1 induced the expression of catabolism-related genes Adamts1 and IL-6,while suppressed the expression of anabolism-related genes Sox9 and Col2a1. The above results demonstrated that TAK1 overexpression induced OA-associated pathological changes including cell cycle arrest,proliferation inhibition,necrotic death and the imbalance of anabolism and catabolism in chondrocytes. Hence TAK1 is likely to be a potential target in clinical treatment of OA. This study has provided clues for further understanding of the molecular mechanism of cartilage degener