Oleoyl-acyl carrier protein hydrolase promotes respiratory syncytial virus-mediated macrophage pyroptosis by inducing mitochondrial oxidative stress

Respiratory syncytial virus (RSV) is a leading cause of bronchitis and pneumonia in infants and the elderly, with alveolar macrophages playing a critical role in pathogenesis. Oleoyl-acyl carrier protein hydrolase (OLAH) exacerbates inflammation in macrophages; however, its specific function during RSV infection remains unclear. THP-1-derived macrophages were infected with RSV, and the expression levels of pyroptosis-related proteins, inflammatory factors, and macrophage apoptosis were detected using Western blotting, ELISA, qRT-PCR, and flow cytometry. Subsequently, OLAH-knockdown macrophages were treated with RSV to assess the impact of OLAH on RSV-induced pyroptosis and inflammatory responses. Additionally, intracellular oxidative stress levels were measured by Oil Red O staining, fluorescent probes, and kits for superoxide dismutase, malondialdehyde, and adenosine triphosphate, while mitochondrial membrane potential was evaluated using a JC-1 kit. Finally, an OLAH-overexpressing macrophage model was constructed and treated with a reactive oxygen species scavenger to investigate the underlying mechanism. RSV infection significantly upregulated pyroptosis-related proteins (GSDMD-FL, GSDMD-N), inflammatory cytokines (IL-1β, IL-18, NLRP3), the apoptosisrelated protein caspase-1, and chemokines (MIP-1α, MIP-1β). Increased macrophage apoptosis and elevated OLAH expression were also observed. OLAH knockdown alleviated RSV-induced pyroptosis, inflammation, and mitochondrial oxidative stress (MOS). This study demonstrates that OLAH facilitates RSV-mediated macrophage pyroptosis through the induction of MOS.