基于GR/NF-κB/HIF-1α信号通路探讨人参皂苷CK对胶原性关节炎大鼠滑膜细胞能量代谢异常的调控作用

Changes in metabolism microenviroment of synoviocytes are a primary cause of synovial aberrant activation and bone erosion due to enhanced glycolysis activity of synoviocytes in joint of rheumatoid arthritis(RA). Our previous study indicated that ginsenoside metabolite compound K(CK), a new monomer of Chinese independent intellectual property, decreased expression of Hexokinase 2(HK2) and oxygen consumption rate of glycolysis, inhibited aberrant activation of synoviocytes and alleviated arthritis signs in joint of animal models of arthritis. Glucocorticoid receptor(GR) antagonist blocked action of CK in inhibiting aberrant activation of synoviocytes. Activation of GR inhibited its downstream signaling NF-κB/HIF-1α pathway which promoted glycolysis. Whether or not CK inhibites aberrant activation of synoviocytes by mediating its metabolism of synoviocytes through activation of GR and down-regulating NF-κB/HIF-1α pathway? It was not reported. This project will observe inhibiting aberrant activation of synoviocytes by regulating its metabolism via GR/NF-κB/HIF-1α in vivo and vitro experiments and investigate regulatory role and the mechanism of CK in collagen-induced arthritis (CIA) model. This study will provide a basis for clarifying the molecular mechanism of CK with treatment of RA.

关节滑膜细胞能量代谢转化为糖酵解途径，产生代谢微环境改变是导致类风湿关节炎（RA）病人关节滑膜异常活化和骨破坏的主要原因。课题组前期研究发现人参皂苷CK作为我国自主知识产权的新型单体，可以明显降低糖酵解限速酶己糖激酶2（HK2）的表达和糖酵解氧耗率，抑制滑膜细胞异常活化，减轻实验性关节炎动物模型关节症状，且CK抑制滑膜细胞功能活化的作用可被糖皮质激素受体（GR）拮抗剂阻断。GR下游NF-κB/HIF-1α信号通路活化后促进糖酵解，而GR激活能够抑制其信号通路的活化。那么CK能否作为GR的激动剂，通过下调NF-κB/HIF-1α信号通路调控滑膜能量代谢，抑制其异常活化?未见报道。本项目拟建立胶原性关节炎模型，通过体内外实验，探讨CK是否通过GR/NF-κB/HIF-1α信号通路调控滑膜细胞能量代谢抑制其活化，为阐明CK治疗RA的分子机制提供实验基础。

课题组前期发现，人参皂苷CK作为我国自主知识产权的新型单体可以明显降低糖酵解限速酶己糖激酶2（HK2）的表达和糖酵解氧耗率，抑制滑膜细胞异常活化，减轻实验关节炎动物模型关节症状，且CK抑制滑膜细胞活化的作用可被糖皮质激素受体（GR）拮抗剂阻断。GR下游NF-κB/HIF-1α信号通路活化后促进糖酵解，而GR激活能够抑制其信号通路的活化。本项目以RA动物模型和滑膜细胞为研究对象，深入探究了CK对滑膜细胞能量代谢和异常活化的影响。研究结果发现CK可降低CIA大鼠关节滑膜组织的能量代谢和异常活化，并且CK可以激活GR转核抑制NF-κB/HIF-1α信号通路，减少糖酵解关键酶GLUT-1、HK2、PKM1和PKM2, 等的表达，降低葡萄糖摄取和乳酸的产生。上调或者下调GR这些作用会增强或减弱。这些结果表明，GR可能是CK作用的主要靶点，CK通过激活GR抑制NF-κB/HIF-1α信号通路，下调滑膜细胞糖酵解代谢，抑制其异常活化，是其发挥抗炎作用和治疗RA的重要分子机制.