Disulfiram Attenuates Bleomycin-Induced Lung Inflammation and Fibrosis with Reduced Endothelial Pyroptosis and...

Pulmonary fibrosis is a progressive disease characterized by chronic inflammation and ultimately leads to irreversible scarring of lung tissue. Current therapies primarily target fibrotic pathways, such as the antifibrotic agents nintedanib and pirfenidone. In bleomycin-induced lung fibrosis models, neutrophils are critical contributors, yet anti-neutrophilic strategies remain underexplored. To address this unmet need, this study characterizes the associations between neutrophilic inflammation and neutrophil adhesion, lung inflammation, and fibrosis in bleomycin models. It further evaluates the effects of disulfiram on neutrophil-driven responses, focusing on pyroptosis-related endothelial dysfunction.

Disulfiram was administered to 8-12-week-old male C57BL/6 mice by intraperitoneal injection at a dose of 25 or 50 mg/kg daily for five days per week, starting 24 hours after intratracheal injection of bleomycin at 1.5 U/kg. Lung histopathology, chemokine receptor expression, and regulatory signaling pathways were analyzed at 7 or 14 days following bleomycin administration with and without disulfiram treatment.

Histological analysis demonstrated that disulfiram significantly reduced lung inflammation and fibrosis, as evidenced by hematoxylin and eosin staining and Ashcroft scoring of lung sections. Disulfiram treatment also decreased N-terminal gasdermin D (N-GSDMD) levels, a main player in the mechanism of pyroptosis. Furthermore, significant downregulation of key markers, including lymphocyte antigen 6G, myeloperoxidase, phospho-nuclear factor kappa-light-chain-enhancer of activated B cells, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1, was observed in disulfiram-treated bleomycin-induced pulmonary fibrosis mice. Additionally, disulfiram suppressed pyroptosis activation, which in turn reduced endothelial damage and neutrophil adhesion in human pulmonary microvascular endothelial cells, as evidenced by decreased expression of N-GSDMD, and VCAM-1, together with restoration of CD31 expression.

In conclusion, disulfiram reduced bleomycin-induced lung inflammation and fibrosis by modulating endothelial pyroptosis-related neutrophilic inflammation and adhesion.