MicroRNA-204/-211敲除加重DMM小鼠骨关节炎滑膜增生和滑膜炎症

MicroRNA-204/-211 deficiency aggravates synovial hyperplasia and inflammation in DMM-induced OA mice

目的观察microRNA-204/-211敲除对内侧半月板失稳术(destabilization of the medial meniscus,DMM)所致骨关节炎(osteoarthritis,OA)小鼠的影响。方法使用12只C57BL/6J(WT)小鼠和12只microRNA-204/-211基因敲除(miR-204/-211-dKO)小鼠,WT小鼠随机分为假手术组和DMM组,即WT-control组和WT+DMM组;miR-204/-211-dKO小鼠随机分为假手术组和DMM组,即dKO组和dKO+DMM组。WT+DMM组和dKO+DMM组行DMM。Von Frey法测定小鼠对疼痛的敏感性。3个月后取材,膝关节行微计算机断层扫描(Micro-CT)检测、组织染色以及免疫组化分析,RT-qPCR检测DRG组织中相关疼痛和炎症因子。结果与WT-control组小鼠相比,WT+DMM组小鼠出现骨赘形成、软骨下骨硬化、疼痛阈值下降等典型OA症状,软骨中Ⅱ型胶原的表达降低、MMP13的表达升高,DRG中炎症因子以及疼痛相关因子的表达明显升高。与此同时,miR-204/-211 dKO+DMM小鼠较WT+DMM小鼠OA症状更加明显,说明miR-204/-211敲除加重了DMM所致小鼠OA。值得注意的是,单纯DMM手术未造成WT小鼠明显的滑膜增生和滑膜炎症,无法完全模拟临床上OA患者的病理特征,而miR-204/-211敲除明显促进DMM小鼠膝关节的滑膜增生和滑膜炎症。结论miR-204/-211敲除小鼠行DMM手术后,不仅出现典型OA特征,而且出现滑膜增生和滑膜炎症,能更好得模拟临床OA患者的病理特征,可作为新的OA模型和筛选抗OA药物的理想动物模型。

Aim To observe the effects of microRNA-204/-211 deficiency on osteoarthritis(OA)induced by medial meniscus amputation(DMM)in mice.Methods 12 C57BL/6J wild-type(WT)mice were randomly divided into sham operation groups and DMM groups,namely WT-control group and WT+DMM group.And twelve microRNA-204/-211 gene knockout(miR-204/-211-dKO)mice were randomly divided into sham operation groups and DMM groups,namely dKO group,and dKO+DMM group.The pain sensitivity of mice was measured by the von Frey test before sacrificing.Three months after the operation,the mice were sacrificed.The knee joints and dorsal root ganglion(DRG)were taken for detection.The subchondral bone structure was detected by micro-CT.Sections of knee joint tissue were stained with toluidine blue,PCNA,typeⅡcollagen and immunohistochemistry.DRG tissues were detected for related pain factors and inflammatory factors by RT-qPCR.Results Compared with the mice in the WT-Control group,mice in the WT+DMM group showed typical OA symptoms such as osteophyte formation,subchondral osteosclerosis,and decreased pain thresholds.The expression of collagenⅡin cartilage significantly decreased,while the expression of MMP13 significantly increased.The expression of inflammatory and pain-related factors in DRG significantly increased.At the same time,the OA phenotypes of mice in dKO+DMM were more obvious than that of mice in the WT+DMM group,indicating that miR-204/-211 deficiency aggravated the OA induced by DMM in mice.In particular,DMM did not cause synovial hyperplasia and synovial inflammation in WT mice,which could not completely represent the pathological characteristics of OA patients in clinical practice.However,miR-204/-211 deficiency significantly promoted synovial hyperplasia and synovial inflammation of knee joints in DMM mice.Conclusions After DMM operation,miR-204/-211 deficient mice showed not only typical OA phenotypes such as osteophyte formation,subchondral osteosclerosis,cartilage destruction and lower pain threshold,but also synovial hyperplasia and synovitis,which could better represent the pathological characteristics of clinical OA patients.MiR-204/-211 deficient mice with DMM can be used as a new OA model and an ideal animal model for screening anti-OA drugs.