Icariin binds to Hk2 to suppress pro-inflammatory polarization of alveolar macrophages by influencing the Hk2/Hk3/Pgk1/glycolysis axis in HDM-induced asthma.

BACKGROUND: Allergic asthma is a common respiratory disorder in which glycolysis-driven pro-inflammatory polarization of alveolar macrophages (AMs) plays an important role. Icariin (ICA), a natural flavonoid glycoside, has mechanisms in house dust mite (HDM)-induced asthma that remain elusive. OBJECTIVE: To investigate the protective effects of ICA against HDM-induced asthma and determine its effects on AMs. METHODS: A murine model of HDM-induced asthma was established, and mice were treated with ICA. High-purity AMs were isolated for transcriptomic and untargeted metabolomic analyses. Surface plasmon resonance (SPR) and molecular docking were performed to assess the binding affinity between ICA and hexokinase 2 (Hk2). The involvement of the Hk2/Hk3/Pgk1 pathway was further validated in vitro using the Hk2 inhibitor 3-BrPA and lentiviral-mediated Hk2 overexpression. RESULTS: ICA alleviated airway inflammation in asthmatic mice and suppressed the pro-inflammatory activation of AMs. Integrated multi-omics analyses showed that ICA restored glycolytic homeostasis by downregulating the Hk2/Hk3/Pgk1 pathway. SPR and molecular docking analyses confirmed direct binding of ICA to Hk2 with high affinity (KD = 27.65 μM). In vitro, ICA suppressed glycolytic flux and pro-inflammatory activation in AMs, effects that were also observed following intervention with 3-BrPA. Hk2 overexpression attenuated ICA's protective effects on AMs, supporting the involvement of the Hk2-mediated glycolytic pathway in ICA's anti-inflammatory activity. CONCLUSION: This study is the first to integrate transcriptomic and metabolomic analyses of AMs from ICA-treated asthmatic mice. The findings suggest that ICA alleviates HDM-induced asthma, potentially by binding to Hk2 and modulating the Hk2/Hk3/Pgk1 pathway, regulating glycolysis and inflammatory responses in AMs.