多模态MR功能成像评价止痛健骨方防治骨关节炎软骨损伤疗效及与Wnt/β-Catenin通路相关性研究

Osteoarthritis (OA) is one of the most common diseases clinically among middle aged and elderly people. Progressive degradation of articular cartilage plays a crucial role in joint dysfunction and disablity. Because there are little methods for evaluation of the response to Chinese medicine treatment in osteoarthritis patients, and condition difference among animal models and sample error could lead to inaccurate results in experimental studies, our study employs functional magnetic resonance multimodality imaging, which is more sensitive and accurate than traditional MR imaging methods in detecting early cartilage lesion, to assess the MR signal characteristics of articular cartilage dynamically in the creation process of osteoarthritis rabbit models and the treatment process by Zhitong-Jiangu recipes, and analyze the relationship of MR signal characteristics, histopathological results and Wnt/β-Catenin signaling pathway. The aim of this study is to find out MR imaging biomarkers to help evaluate response to Chinese medicine in patients/animal models with osteoarthritis, refer to histopathological and molecular biological results. Our study will improve the level of scientific research, and promote academic development in area of osteoarthritis, and provide a more solid foundation for new drug research and development.

骨关节炎是中老年人临床最常见疾病之一，病变关节软骨进行性损伤是导致关节功能障碍及致残的关键。本项目针对中医药防治关节软骨损伤疗效缺乏直接评估手段和实验研究评价方法可能存在抽样误差及组间不均衡等问题，采用能够较为敏感、准确评价关节软骨早期损伤的多模态磁共振功能成像新技术，与局部病理组织学以及Wnt/β-Catenin通路相关蛋白变化对照，研究家兔骨性关节炎模型造模前、后以及止痛健骨方干预前后关节软骨相关系列信号变化特点及其规律，探索以核磁功能成像技术作为中医药治疗骨性关节炎临床疗效和实验模型动物软骨损伤与修复评价的新方法及其组织学和分子生物学基础，建立临床和实验评价指标体系，从而提高科研的科学性和水平，促进学科的发展。

膝骨性关节炎（knee osteoarthritis ，KOA）又称膝退行性骨关节病，影响患者生活质量，给社会带来沉重负担，其中关节软骨的退变、损伤是骨性关节炎发展尤其是后期致残的关键环节。MR T2-mapping通过定量测量软骨横向弛豫时间（T2值），可间接反映软骨中水含量，T1ρ成像通过定量测量T1ρ值，可间接反映软骨中蛋白多糖含量，是无创、准确评估软骨早期退变并监测软骨修复的工具。针对中西医膝骨关节炎药物疗效评价实验及临床研究中缺乏无创定量评价手段等不足，本研究采用改良伸直制动法建立兔KOA模型，以病理为金标准，采用多模态MR功能成像评价OA关节软骨不同损伤程度、止痛健骨方防治骨关节炎软骨损伤疗效，并探索功能成像参数值与Wnt/β-Catenin通路相关性。本研究结果示：（1）随着造模制动时间的延长，关节软骨损伤程度升高，相应关节软骨的OASRI评分升高、T2值升高、T1ρ值升高、II型胶原含量降低、蛋白多糖含量降低。（2）止痛健骨方组关节软骨的II型胶原含量、蛋白多糖含量显著高于模型对照组，OASRI评分显著低于模型对照组，与之对应，止痛健骨方组关节软骨的T2值、T1ρ值均显著低于模型对照组。这提示MR T2-mapping、T1ρ成像具有评价止痛健骨方防治KOA软骨损伤疗效的可行性。其次，止痛健骨方组关节软骨的Wnt5a表达量、β-Catenin表达量、MMP-13表达量显著低于模型对照组，且止痛健骨方组关节软骨的DKK1表达量显著高于模型对照组，这提示止痛健骨方对KOA软骨损伤的防治作用可能是通过下调Wnt5a表达、上调DKK1表达，从而减少MMP-13的产生实现的。（3）T2值、T1ρ值均与关节软骨OASRI评分、Wnt5a表达量、MMP-13表达量存在不同程度的相关性。量化图显示：随着T2值、T1ρ值的升高，OASRI评分也逐渐升高，趋势较平缓；随着T2值、T1ρ值的升高，Wnt5a表达量、MMP-13表达量也会升高，但自变量与预测指标之间可能为非线性关系。这提示综合考虑功能磁共振的定量指标——T2值与T1ρ值，可能具备无创判断关节软骨病理指标的潜力。