Chen Ze, Tang Mingze, Wu Zewei, Lin Yongcong, Wu Cuixi, Huang Hong, Chen Jianmao, Zhu Zhaohua, Liu Yongming, Tang Súan, Ding Changhai, Han Weiyu
Clinical Research Centre, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, China; Centre of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, China; Centre of Orthopedics, The Seventh Affiliated Hospital, Southern Medical University, 28 Liguan Road, Nanhai District, Foshan, Guangdong 528244, China.
Clinical Research Centre, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, China; Centre of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, China.
J Adv Res. 2024 Nov 7. doi: 10.1016/j.jare.2024.11.009.
Cartilage degradation is a critical alteration in the progression of osteoarthritis (OA) due to the disorder of chondrocyte metabolic homeostasis. Autophagy plays an important role in maintaining intracellular homeostasis. Recent investigations have increasingly underscored the importance of autophagy in modulating the pathological mechanisms underlying OA. Ras-related protein Rab-1a (Rab1a) has been illustrated to regulate autophagy in many diseases but not in OA.
This study aims to elucidate whether Rab1a could regulate the development of OA through modulation of chondrocyte autophagy and apoptosis.
Proteomic sequencing, Western blotting, and immunohistochemistry were applied to detect the expression level of Rab1a in vitro and in vivo. Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were rigorously identified. The effects of Rab1a and the interaction between Rab1a, mTORC1, autophagy and apoptosis were explored by qPCR, Western blotting, and immunofluorescence. An experimental mouse OA model was also performed to confirm the role of Rab1a in OA pathogenesis in vivo. Histological analysis was employed to demonstrate cartilage damage.
Rab1a expression was significantly upregulated in inflamed chondrocytes and knee OA cartilage. Inhibition of Rab1a partially attenuated the degradation of the extracellular matrix and cell apoptosis both in vitro and in vivo, whereas overexpression of Rab1a intensified cartilage matrix degradation and cellular apoptosis. Additionally, elevated Rab1a levels were observed to suppress autophagy and activate the mTORC1-S6K signaling pathway, thereby aggravating OA pathogenesis.
The augmentation of Rab1a expression impairs autophagy and promotes apoptosis through the activation of the mTORC1-S6K signaling pathway, further exacerbating OA pathogenesis. This finding suggests that Rab1a serves as a promising and innovative therapeutic target for the prevention and treatment of OA.
由于软骨细胞代谢稳态紊乱，软骨降解是骨关节炎（OA）进展中的关键改变。自噬在维持细胞内稳态中起重要作用。最近的研究越来越强调自噬在调节OA潜在病理机制中的重要性。已证明Ras相关蛋白Rab-1a（Rab1a）在许多疾病中调节自噬，但在OA中并非如此。
本研究旨在阐明Rab1a是否可通过调节软骨细胞自噬和凋亡来调控OA的发展。
应用蛋白质组测序、蛋白质印迹法和免疫组织化学检测体外和体内Rab1a的表达水平。严格鉴定基因本体论术语和京都基因与基因组百科全书通路。通过定量聚合酶链反应、蛋白质印迹法和免疫荧光法探讨Rab1a的作用以及Rab1a、mTORC1、自噬和凋亡之间的相互作用。还建立了实验性小鼠OA模型以证实Rab1a在体内OA发病机制中的作用。采用组织学分析来证明软骨损伤。
Rab1a在炎症软骨细胞和膝OA软骨中表达显著上调。抑制Rab1a在体外和体内均部分减轻细胞外基质降解和细胞凋亡，而Rab1a过表达则加剧软骨基质降解和细胞凋亡。此外，观察到Rab1a水平升高会抑制自噬并激活mTORC1-S6K信号通路，从而加重OA发病机制。
Rab1a表达增加通过激活mTORC1-S6K信号通路损害自噬并促进凋亡，进一步加剧OA发病机制。这一发现表明Rab1a是预防和治疗OA的一个有前景的创新治疗靶点。
