Zhang Wei, Zhang Chi, Hu Chengfang, Luo Congfeng, Zhong Biao, Yu Xiaowei
1Department of Orthopaedics, Shanghai Sixth People's Hospital East Affiliated to Shanghai University of Medicine & Health Sciences, No. 222 3rd Huanhu Road (West), Shanghai, 201306 People's Republic of China.
2Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233 People's Republic of China.
J Inflamm (Lond). 2020 Feb 18;17:8. doi: 10.1186/s12950-020-0234-y. eCollection 2020.
The antisense cerebellar degenerative-related protein-1 (CDR1as) has been identified as a sponge for several microRNAs. MiR-641 has been shown to be downregulated in osteoarthritic human chondrocytes, but its regulation and function in osteoarthritis (OA) has not been reported.
OA cartilage samples were obtained from the knee joints of 12 patients (8 males and 4 females at age of 57-73 years old) who underwent total knee arthroplasty. Normal articular cartilage samples were obtained from the knee joints of 10 trauma patients at age of 29-65 years old (6 males and 4 females). The levels of circRNA-CDR1as mRNA and miR-641 were examined by qRT-PCR and the contents of type II collagen (Col II), IL-6, MMP13 and GAPDH in chondrocytes were examined by Western blot.
In this study, we found that circRNA-CDR1as level was significantly upregulated in OA chondrocytes, and negatively related with that of miR-641. RNA pull down assay confirmed that circRNA-CDR1as directly targets to miR-641. Furthermore, downregulation of circRNA-CDR1as increased type II collagen level but reduced MMP13 and IL-6 contents, while these effects were partly reversed by down-regulation of miR-641.
Overall, our results indicate that circRNA-CDR1as plays a crucial role in regulating OA progression via modulating extracellular matrix metabolism and inflammation via sponging miR-641 and provide a novel regulatory role of circRNA-CDR1as in OA.
反义小脑变性相关蛋白1（CDR1as）已被鉴定为多种微小RNA的海绵。miR-641在骨关节炎人类软骨细胞中表达下调，但其在骨关节炎（OA）中的调控及功能尚未见报道。
OA软骨样本取自12例行全膝关节置换术患者（8例男性，4例女性，年龄57 - 73岁）的膝关节。正常关节软骨样本取自10例创伤患者（6例男性，4例女性，年龄29 - 65岁）的膝关节。采用qRT-PCR检测环状RNA - CDR1as mRNA和miR-641水平，采用蛋白质免疫印迹法检测软骨细胞中Ⅱ型胶原蛋白（Col II）、白细胞介素-6（IL-6）、基质金属蛋白酶13（MMP13）及甘油醛-3-磷酸脱氢酶（GAPDH）含量。
本研究发现，环状RNA - CDR1as在OA软骨细胞中显著上调，且与miR-641水平呈负相关。RNA下拉实验证实环状RNA - CDR1as直接靶向miR-641。此外，下调环状RNA - CDR1as可增加Ⅱ型胶原蛋白水平，但降低MMP13和IL-6含量，而miR-641下调可部分逆转这些作用。
总体而言，我们的结果表明环状RNA - CDR1as通过海绵吸附miR-641调节细胞外基质代谢和炎症，在OA进展调控中起关键作用，并为环状RNA - CDR1as在OA中的调控作用提供了新见解。
