School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China.
Zhongshan Hospital, Xiamen University, Xiamen, 361004, Fujian, China.
Arthritis Res Ther. 2019 Jul 10;21(1):171. doi: 10.1186/s13075-019-1952-5.
Autophagy induction is an effective approach for OA therapy. IL-1β is one of the major inflammatory cytokines linked to OA pathological progression, and its receptor blockade interrupts OA cartilage destruction. The objective of this study was to decipher the link between autophagy and regulatory mechanism of IL-1β and to investigate the effect of IL-1β receptor blockade by IL-1 receptor antagonist (IL-1Ra) combined with or without an autophagy inducer (TAT-Beclin1) on extracellular matrix (ECM) in OA chondrocytes in vitro and in vivo.
IL-1β-treated rat and human OA chondrocytes were cultured in response to IL-1Ra. The expression and distribution of signal molecules regulating ECM synthesis and autophagy were investigated via western blotting, immunoprecipitation, real-time PCR, immunofluorescence, and transmission electron microscope technique. Furthermore, after intra-articular injection of IL-1Ra, TAT-Beclin1, and a combination of both in a rat OA model established by anterior cruciate ligament transection and medial meniscus resection, the morphological changes of cartilage and related signal molecule expression levels were monitored using H.E., Safranin O-Fast green, and immunohistochemistry staining.
Reduced autophagy by IL-1β contributed to ECM degradation, and blockade of IL-1β by IL-1Ra restored autophagy and attenuated ECM degradation in rat and human OA chondrocytes, as well as in a rat OA model. Akt/mTOR/ULK1, Akt/mTOR/NF-κB, and LC3B deacetylation were involved in autophagy regulated by IL-1β. Intra-articular injection of IL-1Ra combined with TAT-Beclin1 was more effective than IL-1Ra alone.
IL-1Ra restored autophagy and attenuated ECM degradation, with an implication that blocking IL-1β combined with enhancing autophagy might be a potential therapeutic strategy for OA.
自噬诱导是治疗 OA 的有效方法。IL-1β 是与 OA 病理进展相关的主要炎症细胞因子之一，其受体阻断可阻断 OA 软骨破坏。本研究旨在阐明自噬与 IL-1β 调节机制之间的联系，并研究 IL-1β 受体阻断剂（IL-1Ra）联合或不联合自噬诱导剂（TAT-Beclin1）对体外和体内 OA 软骨细胞细胞外基质（ECM）的影响。
用 IL-1Ra 培养 IL-1β 处理的大鼠和人 OA 软骨细胞。通过 Western blot、免疫沉淀、实时 PCR、免疫荧光和透射电镜技术研究调节 ECM 合成和自噬的信号分子的表达和分布。此外，在前交叉韧带切断和内侧半月板切除建立的大鼠 OA 模型中，经关节内注射 IL-1Ra、TAT-Beclin1 和两者的组合后，通过 H.E.、Safranin O-Fast green 和免疫组化染色监测软骨的形态变化和相关信号分子表达水平。
IL-1β 抑制自噬导致 ECM 降解，IL-1Ra 阻断 IL-1β 恢复了大鼠和人 OA 软骨细胞以及大鼠 OA 模型中的自噬并减轻了 ECM 降解。Akt/mTOR/ULK1、Akt/mTOR/NF-κB 和 LC3B 去乙酰化参与了 IL-1β 调节的自噬。关节内注射 IL-1Ra 联合 TAT-Beclin1 比单独使用 IL-1Ra 更有效。
IL-1Ra 恢复了自噬并减轻了 ECM 降解，这表明阻断 IL-1β 联合增强自噬可能是 OA 的一种潜在治疗策略。
