Features of wound healing shown by fibroblasts obtained from the superficial and deep dermis

Dermal fibroblasts (DF) obtained from the superficial dermal layer and those from the deep dermal layer have different cellular functions. These differences are often associated with excessive scarring; they also influence early wound healing. We therefore investigated the differences between superficial and deep dermal fibroblasts with special emphasis on their contractile properties, and ability to produce connective tissue. We investigated their proliferation kinetics, ability to contract collagen lattices, and chronological mRNA expression of eight genes associated with wound healing. To estimate the changes in the differences between them during the early phase of wound healing, we investigated mRNA expression in bFGF supplemented medium because bFGF is a representative cytokine that is familiar to clinicians. Superficial DF proliferate faster than deep DF in culture, whereas deep DF are better at contracting collagen lattices than superficial ones. In realtime analysis of polymerase chain reaction, the expression of type I and III collagen, fibronectin, TGF β1 and β3, and connective tissue growth factor were higher in deep DF than in superficial DF, while the expression of TGF β2 was higher in superficial DF. After bFGF supplementation, the relative dominance of mRNA expression between superficial and deep DF remained constant except for the expression of collagenase. According to our analysis, deep DF are superior to superficial DF at promoting wound healing (particularly contraction and production of connective tissue). The intradermal distribution of DF is appropriate for efficient wound healing.