BACKGROUND: Sepsis-associated acute lung injury (ALI) is characterized by unregulated systemic inflammation, disruption of the redox balance, and impaired pulmonary function. Tirzepatide, a synthetic dual GLP-1 and GIP receptor agonist possessing anti-inflammatory and metabolic-regulating properties, was investigated for its protective effects in lipopolysaccharide (LPS)-induced ALI and the underlying mechanisms.
METHODS: A murine model of LPS-induced ALI was employed to examine the protective effects of Tirzepatide. For mechanistic validation, the AMPK inhibitor Compound C was utilized. Histopathological assessment and injury scoring were performed using hematoxylin and eosin (H&E) staining. Aquaporin 5 expression was analyzed via immunohistochemistry. Western blot and real-time PCR were applied to evaluate the levels of genes and proteins associated with the AMPKα/NF-κB p65 signaling pathways.
RESULTS: Tirzepatide reduced oxidative stress by decreasing malondialdehyde (MDA) levels while increasing catalase (CAT) and glutathione (GSH) levels in lung tissue. In bronchoalveolar lavage fluid (BALF), Tirzepatide attenuated inflammatory cell infiltration and lowered pro-inflammatory cytokine concentrations. Furthermore, Tirzepatide significantly mitigated lung tissue pathological damage and alleviated pulmonary edema, as evidenced by a reduced wet/dry weight ratio and normalized Aquaporin 5 expression at both mRNA and protein levels. It also improved lung function parameters, including dynamic compliance (Cdyn), peak expiratory flow (PEF), and airway resistance (RAW). Mechanistically, Tirzepatide activated the AMPK signaling pathway and suppressed NF-κB p65 phosphorylation-effects that were reversed by the AMPK inhibitor Compound C. Tirzepatide also reduced the mRNA expression of downstream NF-κB target genes TNF-α, IL-6, and iNOS, an effect abrogated by Compound C.
CONCLUSION: These findings demonstrate that Tirzepatide alleviates LPS-induced acute lung injury by modulating the AMPK/NF-κB pathway, offering a novel therapeutic candidate and mechanistic insight for ALI treatment.