Zhao Youliang, Duan Meixiu, Qi Yuanmeng, Xia Jiarui, Hao Changfu, Yao Wu
Department of Occupational Health and Occupational Disease, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China.
Department of Occupational Health and Occupational Disease, College of Public Health, Zhengzhou University, Zhengzhou, Henan, PR China.
Int Immunopharmacol. 2025 May 27;156:114723. doi: 10.1016/j.intimp.2025.114723. Epub 2025 Apr 24.
Silicosis is a fibrotic disease caused by prolonged inhalation of silica particles. Signal regulatory protein alpha (SIRPα) and its ligand CD47, key innate immune checkpoints mediating inhibition of phagocytosis, have been reported to regulate organ fibrosis. However, the role of SIRPα/CD47 in silicosis remains unexplored. In this study, a silicosis mouse model was constructed and revealed a significant upregulation of SIRPα and CD47 expression in lung tissue with disease progression. In addition, the expression patterns of SIRPα and CD47 in various silicosis effector cells exhibit distinct cell specificity. Using RRx-001 to block SIRPα/CD47 signaling in mice, we observed a marked reduction in lung injury, decreased collagen deposition, and improved pulmonary function. Mechanistically, blocking SIRPα/CD47 affected T cell activation, macrophage polarization and the expression of pro-inflammatory and pro-fibrotic factors. In vitro, we found that inhibiting SIRPα/CD47 countered the silica-induced suppression of macrophage phagocytosis and induced macrophage polarization towards the M1 phenotype. Additionally, levels of soluble SIRPα and CD47 in the peripheral blood of silicosis patients were significantly higher than those in healthy controls. In summary, this study demonstrates that SIRPα/CD47-mediated immunomodulatory signaling is the driving factor for the progression of silicosis, and this pathway might serve as a therapeutic target for silicosis treatment.
矽肺是一种因长期吸入二氧化硅颗粒而引发的纤维化疾病。信号调节蛋白α(SIRPα)及其配体CD47是介导吞噬作用抑制的关键固有免疫检查点,据报道可调节器官纤维化。然而,SIRPα/CD47在矽肺中的作用仍未得到探索。在本研究中,构建了矽肺小鼠模型,结果显示随着疾病进展,肺组织中SIRPα和CD47表达显著上调。此外,SIRPα和CD47在各种矽肺效应细胞中的表达模式呈现出明显的细胞特异性。使用RRx - 001阻断小鼠体内的SIRPα/CD47信号,我们观察到肺损伤明显减轻、胶原沉积减少以及肺功能改善。从机制上讲,阻断SIRPα/CD47会影响T细胞活化、巨噬细胞极化以及促炎和促纤维化因子的表达。在体外,我们发现抑制SIRPα/CD47可对抗二氧化硅诱导的巨噬细胞吞噬作用抑制,并诱导巨噬细胞向M1表型极化。此外,矽肺患者外周血中可溶性SIRPα和CD47水平显著高于健康对照。总之,本研究表明SIRPα/CD47介导的免疫调节信号是矽肺进展的驱动因素,该通路可能成为矽肺治疗的靶点。