Fig. 1.

The role of fibroblasts and myofibroblasts in scar formation. (1) During the inflammatory phase, various cytokines and inflammatory factors stimulate fibroblasts to undergo phenotypic changes. (2) In the proliferative phase, fibroblasts produce large amounts of cytokines and extracellular components by secretory action, which cause ECM accumulation. Fibroblasts are transformed into myofibroblasts through differentiation, which cause wound contraction and further ECM accumulation. Meanwhile, the migratory of fibroblasts is enhanced. (3) During the remodeling phase, the extracellular component secreted by fibroblasts is reduced and the MMPs secreted by fibroblasts help the scar remodeling. Concurrently, fibroblasts and myofibroblasts are partially apoptotic, which contributed to the reduction of ECM. (4) EMT also has an important role in wound healing, during which epidermal cells and endothelial cells can differentiate into fibroblasts and myofibroblasts. “↑” and “↓” represent increase and decrease, respectively