Effect and mechanism of action of botulinum toxin type A on hypertrophic scar <i>in vitro</i>

Abstract

Purpose: To examine the effect of botulinum toxin type A (BTXA) on the formation of hypertrophic scar and to unravel its mechanism of action. Methods: HSF cells were isolated from hypertrophic scars and cultured. Immunohistochemistry (IHC) assays were performed to determine TGF-β1, FN, and Col1 expressions in hypertrophic scar and normal tissues while the expressions and phosphorylation of p38, ERK, JNK, as well as the expressions of α-SMA, Col1 and FN1 in HSF cells were evaluated by immunoblot techniques. CCK-8 and Transwell assays were used to assess the effect of BTXA on the viability and motility of HSF cells. Results: BTXA suppressed MAPK pathway in hypertrophic scar fibroblasts (p < 0.01). It also suppressed excessive collagen deposits in hypertrophic scar through MAPK pathway (p < 0.01), and restrained HSF growth and motility via MAPK pathway (p < 0.01). Conclusion: BTXA suppresses hypertrophic scarring via MAPK pathway and thus, can potentially be developed as a drug for the treatment of hypertrophic scarring.