mTOR-ULK1-BECN1功能中心与自噬代谢在骨关节炎中的作用

Osteoarthritis (OA) is the leading disability degenerative disease without effective therapy and its mechanism remains unclear. OA is very common in the elderly, closely related to aging, which is delayed by autophagy. Our previous study reported that deregulation of mTOR,ULK1 and BECN1 took places in OA , along with fault modes of four functional modules,such as metabolism, immunity, apoptosis and stem cell signaling networks, indicating that OA is at least partly due to the downregulation of autophagy. At the same time,we firstly identified a metabolic feature to predict the occurrence of OA alongside an accuracy rate of 93% by using the metabonomics in OA mice model.So we intend to identify the OA metabolic dynamic network biomarkers and a critical transition state of OA.Further, towards precision-control of autophagy, the tissue -specific conditional knockout /over-expression transgenic and pharmaceutic interventions on mTOR-ULK1- BECN1 functional hub will be applied to determine how the precise role of autophagy affects the fault mode, effect and criticality of four major functional modules in spontaneous and injury OA murine models, and to explore the modulation of OA criticality and dynamic network biomarkers.Our research aim to further clarify the mechanism of autophagy disorders during the OA-genesis, so as to reverse the deregulation of OA function modules, to pave the way of the precise prediction of early OA morbidity and precision therapy of OA as well.

骨关节炎（OA）是首位致残性疾病，发病机制不详，临床用药疗效差。OA是一种退行性病变，与衰老相关，而自噬可延缓衰老。我们的前期研究发现OA中自噬调控中心的mTOR、ULK1和BECN1表达异常，导致OA自噬下调，伴代谢、免疫、凋亡以及干细胞信号网络四大功能模块异变即下游靶点表达失调，并率先利用代谢组学在小鼠OA模型上鉴定了一组可预测高脂诱导OA发生的表达谱(准确率93%），故设想通过进一步鉴定OA的代谢动态网络标志物(DEB)即上游关键致病基因群，找到ＯＡ临病界点。本课题拟在组织特异的条件性基因敲除，过表达或激动剂强化型小鼠上建立自发性和损伤OA的动物模型，并且系统地研究mTOR-ULK1-BECN1调控中心在精准地强化激活和抑制自噬下对四大功能模块的影响，探寻其对OA临病界点转变的DEB，从而确定OA中自噬失调机制，逆转OA功能模块的异变，为尽早预测OA发病、精准治疗奠定坚实基础。

背景：骨关节炎（Osteoarthritis，OA）患者在中国1.5亿多；OA是一种退行性衰老相关病，预防-诊断-治疗选择非常有限。项目负责人以前发表了自噬主控基因雷帕霉素（RAPA）靶点(TOR)缺失导致线虫寿命可以翻倍(Nature, 2003)，贡献入Nature 150年纪念评的长寿衰老领域20个里程碑；其OA研究在专业顶刊率先证明自噬防止软骨退化(ARD2015a,b；IF19.1)，受哺乳动物RAPA靶点(mTOR)负调节。主持人瑞士导师Muller lab的大隅良典修博士后有合作克隆UNC-51/ATG1/ULK1,且获得2016年自噬诺奖；mTOR研究者Hall获2017年医学Lasker Award。RAPA为研究抗衰“神药”热点。中药雷公藤联合应用RAPA等对OA作用很有必要。负责人率先用3 和 4 个代谢分子panel预测高脂饮食下OA的发生发展，评为多伦多大学西院过去50年里程碑研究，预测OA准确率为93%，有待深入。 主要研究内容，重要结果、关键数据：是负责人继往OA研究的深入来探索mTOR-BECN1-ULK1调控自噬中心的中西医药物联合优化。重点有：1，药物：雷公藤红素(Celastrol)可促进自噬，率先预测对OA与自噬的作用。Celastrol降低原代OA软骨细胞中的mTOR，降低了P62，增加了LC3-II，表明celastrol促进自噬和软骨保护。与RAPA联合更强。2,炎症，外源性基质细胞衍生因子-1（SDF-1/CXCR4）激活AMPK抑制NLRP3炎症体，抑制OA滑膜细胞的焦亡凋亡。3，干性：PPARg-mTOR通路与滑膜干细胞源胞外囊泡对OA软骨细胞改良表现在吡格列酮、滑膜干细胞源胞外囊泡可下调mTOR表达，两者协同；吡格列酮、滑膜干细胞源胞外囊泡上调PPAR-γ、LC3表达，两者允余。4，代谢：自噬模块mTOR, p62, lc3均在ATX inhibitor作用后表达升高，分解代谢biomarker表达升高，合成代谢biomarker表达下降，说明ATX inhibitor对OA软骨促降解。5，自噬：ULK1 敲除小鼠或基因沉默，软骨细胞中自噬及合成代谢 LC3B，ACAN1 下调分解代谢 MMP-13 升高；ULK1 过表达反之。BECN1 过表达无显效。意义：促进OA的mTOR/自噬阐明与中西医药物研发。