Phillyrin for sepsis-related acute lung injury: A potential strategy suppressing GSK-3β

The efficacy of clinical drugs for acute lung injury/acute respiratory distress syndrome (ALI/ARDS) remains suboptimal. Phillyrin (PHN), a compound derived from Forsythia, is believed to alleviate sepsis-related ALI/ARDS; however, its mechanisms are not fully elucidated. In this study, we screened 8331 target genes associated with ALI/ARDS from public databases and identified six hub genes relevant to PHN treatment: AKT1, GSK-3β, PPP2CA, PPP2CB, PPP2R1A, and AR. Receiver operating characteristic analysis and single-cell sequencing analysis revealed the expression of AKT1, GSK-3β, PPP2CA, PPP2CB, and PPP2R1A were markedly elevated. Molecular docking and dynamics simulations indicated that PHN forms a structurally stable complex with glycogen synthase kinase-3β (GSK-3β). Mendelian randomization analyses suggested that PHN, as a potent GSK-3β inhibitor, may promote M2 macrophage polarization and reduce neutrophil recruitment. We validated these findings through in vivo and in vitro experiments, demonstrating that PHN lowers iNOS levels and raises MMR levels by downregulating GSK-3β mRNA expression and protein activity during lipopolysaccharide (LPS)-induced macrophage inflammation. Additionally, PHN inhibited GSK-3β mRNA expression and protein activity, reducing NF-κB-p65 nuclear translocation in LPS-induced zebrafish inflammation and mice ALI. This inhibition decreased levels of TNF-α and IL-6, increased IL-10 levels, promoted M2 macrophage polarization, suppressed neutrophil recruitment, and ultimately ameliorated ALI/ARDS. In conclusion, our results indicate that PHN effectively alleviates LPS-induced ALI/ARDS by suppressing GSK-3β signaling.