Fibroblast growth factor 21 improves lipopolysaccharide-induced pulmonary microvascular endothelial cell dysfunction and inflammatory response through SIRT1-mediated NF-κB deacetylation

Pneumonia is a common infectious disease of the respiratory system in children. It often leads to death in children by causing acute lung injury. Fibroblast growth factor 21 (FGF21) is a peptide hormone that plays an important role in the regulation of energy homeostasis. This study aimed to investigate the role of FGF21 in alleviating the lipopolysaccharide (LPS)-induced human pulmonary microvascular endothelial cell (HPMEC) injury, as well as the underlying mechanism. The expression of sirtuin 1 (SIRT1), NF-κB p65, Ac-NF-κB p65, apoptosis-related proteins, tight junction proteins and adhesion molecules in HPMECs were analyzed by Western blotting. The viability and apoptosis of HPMECs were detected by CCK-8 and TUNEL assays. Lactate dehydrogenase level and levels of inflammatory factors were respectively determined by assay kits. The mRNA expression of adhesion molecules in HPMECs was analyzed by RT-qPCR. As a result, SIRT1 expression was decreased and the expression of NF-κB p65 and Ac-NF-κB p65 were increased in LPS-induced HPMECs, which were reversed by recombinant FGF21 (rFGF21). rFGF21 increased the viability and inhibited the apoptosis, inflammatory response, permeability, and release of cell adhesion molecules of LPS-induced HPMECs. In addition, EX527 as SIRT1 inhibitor could reverse the effect of rFGF21 on LPS-induced HPMECs. In conclusion, FGF21 improved LPS-induced HPMEC dysfunction and inflammatory response through SIRT1-mediated NF-κB deacetylation.