Acceleration of Palatal Wound Healing in Smad3-deficient Mice

Wound healing is a well-orchestrated complex process leading to the repair of injured tissues. It is suggested that transforming growth factor (TGF)-β/Smad3 signaling is involved in wound healing. The purpose of this study was to investigate the role of TGF-β/Smad3 signaling in palatal wound healing in Smad3-deficient (Smad3−/−) mice. Histological examination showed that wound closure was accelerated by the proliferation of epithelium and dermal cells in Smad3−/− mice compared with wild-type (WT) mice. Macrophage/monocyte infiltration at wounded regions in Smad3−/− mice was decreased in parallel with the diminished production of TGF-β1, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α compared with WT mice. Fibrocytes, expressing hematopoietic surface marker and fibroblast products, were recruited and produced α-smooth-muscle actin in WT mice, but were not observed in Smad3−/− mice. These results suggest that TGF-β/Smad3 signaling may play an important role in the regulation of palatal wound healing.