Semaglutide ameliorates lipopolysaccharide-induced acute lung injury through inhibiting HDAC5-mediated activation of NF-κB signaling pathway

Background:As a life-threatening respiratory syndrome, acute lung injury (ALI) is characterized by uncontrollable inflammatory activities. Semaglutide (SEM) has been identified as an effective anti-inflammatory drug in a variety of diseases. This study intended to explore the functional effect and potential mechanisms of SEM in ALI. Methods: Lipopolysaccharide (LPS) was used to construct an in vivo ALI model based on Sprague-Dawley (SD) rats and an in vitro ALI model based on human pulmonary artery endothelial cells (HPAECs). Hematoxylin & eosin (H&E) staining and ELISA were applied to evaluate the histopathological changes in pulmonary tissues and detect TNF-alpha and IL-6 levels. RT-qPCR and Western blotting were used to measure gene and protein expressions in pulmonary tissues and cells. HPAEC viability and apoptosis were evaluated by CCK-8 method and flow cytometry methods. Results: Semaglutide pretreatment significantly mitigated pulmonary injury, reduced TNF-alpha and IL-6 production, and led to a decrease in cleaved caspase-3 level and an increase in Bcl-2 level, suggesting SEM could ameliorate LPS-induced ALI in rats. In vitro, SEM increased the proliferative capability and mitigated inflammation and apoptosis in LPS-stimulated HPAECs. In addition, SEM inhibited HDAC5-mediated NF-kappa B signaling pathway in HPAECs. HDAC5 overexpression or NF-kappa B signaling activation could partly impair SEM-mediated protective effects against LPS-induced damage to HPAECs. Conclusion: Semaglutide restrains LPS-induced ALI by inhibiting HDAC5/NF-kappa B signaling pathway.