The Role of Mast Cells in Fetal Wound Healing

Normally, in adults, wounds to the skin end in the formation of a scar. Scar tissue formation inhibits the normal functioning of skin and can lead to limited joint mobility, impaired growth, and wound dehiscence. This abnormal tissue often results from excessive inflammation at the wound site. Recently, studies have found that major differences exist in the healing process of adult and fetal skin, the most noteworthy of which is the lack of scar formation in fetal wounds. In mice, scarless healing occurs up until embryonic day sixteen (E16). One possible reason for the disparity in wound healing between adult and fetal skin could be the presence of different numbers of mast cells, a specific type of inflammatory cell. Toluidine blue was used to identify mast cells within both unwounded and wounded E15 and E18 skin. A significantly larger number of mast cells were found in unwounded E18 skin, which forms scars after injury, than were found in unwounded E15 skin. The mast cells in the unwounded E18 skin also possessed more granules than those found in the unwounded E15 skin. Similarly, a significantly larger number of mast cells were found in wounded E18 skin than were found in wounded E15 skin. The mast cells in the wounded E18 skin also released a larger number of granules indicating the presence of more activated mast cells. The results obtained in this study suggest a relationship between mast cell presence and the transition from scarless and fibrotic healing which takes place during development. These findings could lead to future studies which could develop new drugs and therapies that may help reduce or even eliminate scar formation in the future.No embarg