Resveratrol Ameliorates Hypertrophic Scar Formation by Regulating <scp>ASIC3</scp> ‐Mediated Fibroblast–Macrophage Crosstalk: A Mechanistic Study

To elucidate the mechanism by which Resveratrol (Res) ameliorates hypertrophic scar (HS) formation by targeting acid-sensing ion channel 3 (ASIC3) to modulate macrophage-fibroblast (FB) crosstalk. A rabbit-ear HS model was established in vivo. Hematoxylin-eosin (H&E) staining, Masson staining, immunofluorescence (IF), Western blot (WB), and quantitative real-time PCR (RT-qPCR) were used to assess the effects of Res on scar hyperplasia, collagen deposition, FB activation, and macrophage polarization. In vitro, FB activation was stimulated by combined treatment with TGF-β1 and lactic acid, and a Transwell co-culture system comprising FB and human monocyte-derived M0 macrophages was established. Scratch assay, FCM, IF, and WB were performed to assess the impacts of Res on FB activation, migration, and macrophage polarization. Additionally, ASIC3 gene knockout experiments were conducted both in vivo and in vitro to confirm the mechanism underlying Res-mediated HS improvement. In vitro, Res significantly inhibited FB migration in a dose-dependent manner and downregulated the protein expression of α-SMA, COL1A1, COL3A1, reduced M-CSF secretion, suppressed macrophage polarization toward the M2 phenotype, and decreased TGF-β1 mRNA expression. It also blocked activation of the PI3K/Akt signaling pathway downstream of ASIC3. These effects were completely abolished after ASIC3 gene knockdown. In vivo, Res significantly reduced the scar elevation index (SEI) in rabbit-ear HS. It improved collagen fiber arrangement and decreased collagen deposition. It markedly inhibited M2 macrophage polarization and TGF-β1 mRNA expression. After ASIC3 knockout, the anti-HS effects of Res, as well as its regulatory effects on macrophage polarization and fibrotic factors, were abrogated. Res ameliorates HS by inhibiting ASIC3 expression. This disrupts the ASIC3-M-CSF-TGF-β1 positive feedback loop. It restores the balance of macrophage polarization, inhibits FB activation, reduces abnormal collagen deposition, and ultimately attenuates HS formation.