Codonopsis pilosula (Dangshen) decoction promotes NR2F2-dependent pulmonary endothelial repair in an H9N2-induced lung injury model

ETHNOPHARMACOLOGICAL RELEVANCE: Codonopsis pilosula (Dangshen) has long been used for conditions related to "lung and spleen qi deficiency", including fatigue and cough/shortness of breath, and is commonly prescribed during convalescence. AIM OF THE STUDY: To test whether a chemically characterized C. pilosula decoction promotes pulmonary endothelial repair after H9N2-induced injury and whether this effect is NR2F2 (COUP-TFII)-dependent. MATERIALS AND METHODS: The decoction was chemically profiled (HPLC/LC-MS) to provide a reference fingerprint. H9N2-challenged mice received low-, medium- or high-dose decoction. Lung injury, edema and inflammatory indices were assessed together with endothelial markers (CD31, VE-cadherin) and junctional proteins. NR2F2 and downstream effectors (NRP1, CCND1) were quantified at mRNA and protein levels. In vitro, H9N2-injured mouse pulmonary microvascular endothelial cells (MVECs) were treated with C. pilosula-containing serum, with or without NR2F2 overexpression or knockdown. Viability/proliferation, migration, tube formation and transendothelial electrical resistance (TEER) were measured, alongside pathway activation. RESULTS: In vivo, the decoction ameliorated H9N2-induced lung injury, reduced edema/inflammatory readouts and improved barrier-associated outcomes. It preserved pulmonary microvascular endothelial abundance and continuity, as indicated by restored CD31 and VE-cadherin signals, and was accompanied by recovery of junctional markers. Mechanistically, NR2F2 expression was increased, with concordant upregulation of NRP1 and CCND1 at transcript and protein levels in injured lungs. In vitro, C. pilosula-containing serum enhanced MVEC repair functions, including viability/proliferation, migration and barrier recovery (TEER), together with induction of the NR2F2-NRP1-CCND1 axis. NR2F2 knockdown largely attenuated these effects, while NR2F2 overexpression partially recapitulated key pro-repair phenotypes. CONCLUSION: A chemically characterized C. pilosula decoction supports NR2F2-dependent endothelial repair after viral-induced lung injury.