Peking University Third Hospital, Beijing, China.
Arthritis Rheumatol. 2014 Apr;66(4):969-78. doi: 10.1002/art.38309.
Long noncoding RNAs (lncRNAs) play crucial regulatory roles in diverse biologic processes, but knowledge of lncRNAs in osteoarthritis (OA) is limited. The aim of this study was to identify lncRNA expression in articular cartilage and to explore the function of cartilage injury-related lncRNAs (lncRNA-CIR) in OA.
To identify lncRNAs specifically expressed in OA cartilage, we compared the expression of lncRNAs in OA cartilage with that in normal cartilage using microarray and quantitative polymerase chain reaction (qPCR) analyses. In OA cartilage, lncRNA-CIR was specifically, differentially, and highly expressed. The function of lncRNA-CIR was determined by silencing and overexpression in vitro. Extracellular matrix (ECM)-related molecules were detected by qPCR, Western blot, and immunofluorescence analyses.
Up to 152 lncRNAs were found to be differentially expressed (>8-fold) in OA and normal cartilage (82 lncRNAs more highly expressed and 70 less highly expressed in OA cartilage than in normal cartilage). A specific differentially expressed lncRNA-CIR was selected according to the results of the higher expression in OA cartilage and OA chondrocytes. The expression of lncRNA-CIR increased in chondrocytes with in vitro treatment with interleukin-1β and tumor necrosis factor α. Silencing of lncRNA-CIR by small interfering RNA promoted the formation of collagen and aggrecan and reduced the expression of matrix-degrading enzymes, such as MMP13 and ADAMTS5. The expression of collagen and aggrecan was reduced, whereas the expression of matrix-degrading enzymes was increased, after overexpression of lncRNA-CIR.
The results indicate that lncRNA-CIR contributes to ECM degradation and plays a key role in the pathogenesis of OA. We propose that lncRNA-CIR could be used as a potential target in OA therapy.
长链非编码 RNA（lncRNA）在多种生物过程中发挥着至关重要的调控作用，但目前对骨关节炎（OA）中的 lncRNA 知之甚少。本研究旨在鉴定关节软骨中的 lncRNA 表达，并探讨与软骨损伤相关的 lncRNA（lncRNA-CIR）在 OA 中的作用。
为了鉴定在 OA 软骨中特异性表达的 lncRNA，我们使用微阵列和定量聚合酶链反应（qPCR）分析比较了 OA 软骨和正常软骨中 lncRNA 的表达。在 OA 软骨中，lncRNA-CIR 特异性、差异和高度表达。通过体外沉默和过表达来确定 lncRNA-CIR 的功能。通过 qPCR、Western blot 和免疫荧光分析检测细胞外基质（ECM）相关分子。
在 OA 和正常软骨中，多达 152 个 lncRNA 被发现存在差异表达（>8 倍；82 个 lncRNA 在 OA 软骨中的表达高于正常软骨，70 个 lncRNA 在 OA 软骨中的表达低于正常软骨）。根据 OA 软骨和 OA 软骨细胞中高表达的结果，选择了一种特定的差异表达 lncRNA-CIR。lncRNA-CIR 的表达在体外用白细胞介素-1β和肿瘤坏死因子-α处理的软骨细胞中增加。通过小干扰 RNA 沉默 lncRNA-CIR 可促进胶原蛋白和聚集蛋白聚糖的形成，并减少基质降解酶（如 MMP13 和 ADAMTS5）的表达。lncRNA-CIR 过表达后，胶原蛋白和聚集蛋白聚糖的表达减少，而基质降解酶的表达增加。
结果表明，lncRNA-CIR 有助于 ECM 降解，并在 OA 的发病机制中发挥关键作用。我们提出，lncRNA-CIR 可以作为 OA 治疗的潜在靶点。
