代谢分子影响巨噬细胞(Mφ)的活化，亦被发现参与关节炎症的发生；预实验提示丙酮酸激酶2（PKM2）可介导关节炎的进程，本研究拟证实PKM2调控Mφ活化和功能进而参与关节炎症的发展。首先在关节炎动物中确定高表达PKM2的细胞类型，分析PKM2与关节炎进程的关系；继而在PKM2敲低/过表达Mφ活化模型上检测信号通路活化情况，并用免疫共沉淀等手段确定其调控的效应分子，通过分子模拟、点突变等方法揭示PKM2与其相互作用分子之间的作用位点，阐明其对Mφ活化和功能调控机制；再利用免疫共沉淀、RNAi等方法从转录和转录后剪切过程解析调控PKM2高表达的机制；最后在Mφ条件性敲除小鼠关节炎模型和RA患者样本中检测PKM2及其相关分子的表达和活化情况，分析和关节炎发生发展的关系，确定PKM2调控Mφ介导关节炎中的作用。结果将丰富糖代谢调节酶调控Mφ参与关节炎发病机制的认识，为关节炎的诊疗提供理论和实验依据。

Macrophages play crucial roles on the initiation and development of inflammatory arthritides, especially in rheumatoid arthritis (RA). The activated macrophages during inflammation of joints may be regulated by some metabolic enzymes. Our preliminary data recently showed that pyruvate kinase muscle type 2 (PKM2) was feasibly involved in the development of pristane induced arthritis (PIA) in DA rats, which also participated in macrophage activation. So we propose the hypothesis that PKM2 regulates the activation and function of macrophages, contributing to the development of arthritis. We intend to prove our hypothesis by the following experiments. Firstly, the expression of PKM2 will be detected in spleen macrophages and synovial macrophages. The function of PKM2 in arthritis development will be investigated by RNAi in vivo in PIA rats. Secondly, the mechanism of PKM2 regulating macrophage activation will be studied from 2 aspects. The activated signal pathways will be screened and analyzed in PKM2 knocking-down macrophages by Western blotting to obtain the signal molecules and the downstream effect molecules which are associated with PKM2. The molecule which interacts with PKM2 could be captured by co-immunoprecipitation in PKM2 high-expressed macrophages. And then, we would like to use the computational biology method to mimic the domains of captured protein that PKM2 interact with. Thirdly, the regulatory molecules of PKM2 in activated macrophages are pinpointed in transcriptional and post-transcriptional levels. Finally, the function of PKM2 in arthritis development will be further confirmed by establishing the CIA animal model using macrophage conditional knockout mice and human RA samples. We insist that the results should offer strong evidence to support the hypothesis that the aerobic glycolysis enzyme PKM2 may participate in the initiation and development of inflammation of joints by regulating the activation and function of macrophages. Also, the findings will provide new insights into understanding the pathogenesis of RA and supply novel molecular targets for the prevention, diagnosis, therapy and new drug development of arthritis.