Immunophenotypical Analyses of Myofibroblasts in Rat Excisional Wound Healing: Possible Transdifferentiation of Blood Vessel Pericytes and Perifollicular Dermal Sheath Cells into Myofibroblasts

The study investigated the origin and characteristics of myofibroblasts in rat wound healing, focusing on their potential derivation from pericytes and perifollicular dermal sheath cells. Myofibroblasts, which produce collagen and contribute to cutaneous fibrosis, were analyzed for expressions of vimentin, desmin, and α-smooth muscle actin (α-SMA). These cells were first observed on post-wounding day 5, peaked on day 9, and decreased thereafter. Immunolabeling showed that pericytes in new blood vessels and perifollicular dermal sheath cells shared similar markers with myofibroblasts, suggesting that myofibroblasts might originate from these cells, possibly through transdifferentiation from stromal-/bone marrow-stem cells.