Department of Orthopaedics, The First Affiliated Hospital of Anhui Medical University, 218#Ji Xi Road, Hefei, 230032, Anhui, China.
Department of Orthopaedics, The Fourth Affiliated Hospital of Anhui Medical University, 372#Tun Xi Road, Hefei, 230032, Anhui, China.
J Bone Miner Metab. 2019 Nov;37(6):976-986. doi: 10.1007/s00774-019-01016-w. Epub 2019 Jun 18.
Several cellular and molecular processes participate in the pathologic changes of osteoarthritis (OA). However, the core molecular regulators of these processes are unclear, and no effective treatment for OA disease has been developed so far. ANGPTL2 is well known for its tissue remolding and pro-inflammation properties. However, the role of ANGPTL2 in osteoarthritis (OA) still remains unclear. To explore the expression level of ANGPTL2 in human OA cartilage and investigate the function of ANGPTL2 in human chondrocytes injury, qRT-PCR, western blot and immunohistochemistry were employed to investigate the expression of ANGPTL2 between human OA and normal cartilage samples. Next, human primary chondrocytes were treated with IL-1β to mimic OA progress in vitro, and the expression of ANGPTL2 were tested by qRT-PCR and western blot. Furthermore, the effect of ANGPTL2 in the expression of pro-inflammation cytokines (IL-1β, IL-6), proteolytic enzymes (MMP-1, MMP-13) and component of the cartilage matrix (COL2A1 and aggrecan) in human primary chondrocyte were explored by gain-of-function and loss-of-function methods. Finally, the nuclear factor kappa B (NF-κB) and p38/MAPK signaling pathways were also tested by western blot analysis. In this study, firstly, the expression level of ANGPTL2 was elevated both in human OA cartilage samples and IL-1β stimulated human chondrocytes. Secondly, ANGPTL2 upregulation promotes extracellular matrix (ECM) degradation and inflammation mediator production in human chondrocytes. Finally, ANGPTL2 activated the NF-κB and p38/MAPK signaling pathways via integrin α5β1. This study, for the first time, highlights that ANGPTL2 secreted by human chondrocytes plays a negative role in the pathogenesis of osteoarthritis, and it may be a potential therapeutic target in OA.
几种细胞和分子过程参与骨关节炎(OA)的病理变化。然而,这些过程的核心分子调节剂尚不清楚,到目前为止,还没有开发出有效的 OA 疾病治疗方法。ANGPTL2 以其组织重塑和促炎特性而闻名。然而,ANGPTL2 在骨关节炎(OA)中的作用仍不清楚。为了探讨 ANGPTL2 在人 OA 软骨中的表达水平,并研究 ANGPTL2 在人软骨细胞损伤中的作用,采用 qRT-PCR、western blot 和免疫组化法检测人 OA 软骨和正常软骨样本中 ANGPTL2 的表达。接下来,用 IL-1β处理人原代软骨细胞,在体外模拟 OA 进展,并用 qRT-PCR 和 western blot 检测 ANGPTL2 的表达。此外,通过功能获得和功能丧失方法探讨 ANGPTL2 对人原代软骨细胞中促炎细胞因子(IL-1β、IL-6)、蛋白水解酶(MMP-1、MMP-13)和软骨基质成分(COL2A1 和聚集蛋白聚糖)表达的影响。最后,通过 western blot 分析还检测了核因子 kappa B(NF-κB)和 p38/MAPK 信号通路。在这项研究中,首先,ANGPTL2 的表达水平在人 OA 软骨样本和 IL-1β 刺激的人软骨细胞中均升高。其次,ANGPTL2 的上调促进了人软骨细胞外基质(ECM)降解和炎症介质的产生。最后,ANGPTL2 通过整合素 α5β1 激活 NF-κB 和 p38/MAPK 信号通路。这项研究首次强调了人软骨细胞分泌的 ANGPTL2 在 OA 发病机制中起负面作用,它可能是 OA 的一个潜在治疗靶点。