Penehyclidine hydrochloride alleviates one-lung ventilation-induced lung injury by disrupting PLAT2-mediated glycerophospholipid metabolism and macrophage polarization

BACKGROUND: One-lung ventilation (OLV), essential in thoracic surgery, frequently induces acute lung injury characterized by inflammation and impaired oxygenation. Penehyclidine hydrochloride (PHC) has demonstrated organ-protective potential, but its efficacy against OLV-induced injury and the underlying mechanisms, particularly concerning macrophage polarization and metabolic reprogramming, remain poorly defined. METHODS: A murine OLV model was established. Mice received intravenous PHC (0.15 mg/kg) or saline 30 min prior to OLV. Lung injury was assessed via PaO₂/FiO₂ ratio, wet/dry weight ratio, and histology. Inflammation was evaluated by measuring cytokines (IL-1β, TNF-α, IL-6, CCL2) in bronchoalveolar lavage fluid (BALF) and lung tissue. Bone marrow-derived macrophages (BMDMs) were used for in vitro studies. Metabolomics, molecular docking, qPCR, western blotting, and flow cytometry were employed to investigate the PHC- phospholipase A/acyltransferase 2 (PLAT2)-glycerophospholipid axis. Rescue experiments involved PLAT2 overexpression and LPC supplementation. RESULTS: PHC pretreatment significantly improved oxygenation, reduced pulmonary edema, and attenuated pathological lung injury and inflammatory cytokine production following OLV. PHC suppressed M1 macrophage polarization both in vivo and in vitro. Mechanistically, PHC downregulated PLAT2, disrupting glycerophospholipid metabolism and reducing lysophosphatidylcholine (LPC) production. LPC was found to promote inflammation via the TLR4/MyD88/NF-κB pathway. Crucially, both PLAT2 overexpression and LPC supplementation reversed the anti-inflammatory and protective effects of PHC. CONCLUSION: PHC protects against OLV-induced lung injury by inhibiting PLAT2 expression in macrophages, thereby reducing LPC generation and subsequent TLR4/NF-κB-mediated M1 polarization. These findings identify PLAT2 as a novel therapeutic target and support the potential prophylactic use of PHC in patients undergoing OLV.