VX-765 attenuates silica-induced lung inflammatory injury and fibrosis by modulating alveolar macrophages pyroptosis in mice

Silicosis is a diffuse fibrotic lung disease in which excessive inflammatory responses are triggered by silica exposure. Pyroptosis, a pro-inflammatory mode of programmed cell death, is mediated by gasdermin and may play a pivotal role in the development of silicosis. The caspase-1 inhibitor, VX-765, was used in vivo and in vitro to investigate the effects of silica-induced early inflammatory injury and later lung fibrosis. Our findings show that VX-765 reduces inflammatory lung injury by inhibiting silica-induced pyroptosis of alveolar macrophages in a silicosis mouse model. VX-765 limits the infiltration of inflammatory M1 alveolar macrophages, decreasing expression of inflammatory cytokines, including IL-1β, TNF-α, IL-6, CCL2, and CCL3, and down-regulating endogenous DAMPs and inflammatory immune-related cell pattern recognition receptors TLR4 and NLRP3. Furthermore, VX-765 alleviates fibrosis by down-regulating α-smooth muscle actin (α-SMA), collagen, and fibronectin. In this study, we illustrate that Alveolar macrophages pyroptosis occur in the early stages of silicosis, and VX-765 can alleviate the development of silicosis by inhibiting the pyroptosis signaling pathway. These results may provide new insight into the prevention and treatment of early-stage silicosis. •VX-765 attenuates silica-induced macrophage pyroptosis by blocking caspase-1 activation.•VX-765 reduces immune inflammatory responses by inhibiting AMs pyroptosis early in silica exposure.•VX-765 ameliorates late pulmonary fibrosis induced by silica.