Mast cells (MCs) have recently been reported to play a pivotal role in the elicitation of inflammatory reactions that are beneficial to the host, e.g., during innate immune responses to bacteria. To explore whether MCs also contribute to wound repair, we studied experimentally induced skin wounds in MC-deficient KitW/KitW-v mice, normal Kit+/+ mice, and MC-reconstituted KitW/KitW-v mice. Wound closure was significantly impaired in the absence of MCs during the first 6 days of wound healing and histomorphometric analyses of MC degranulation at the wound edges revealed distance-dependent MC activation, i.e., MC degranulation was most prominent directly adjacent to the wound. In addition, KitW/Kit W-v mice showed impaired extravasation and recruitment of neutrophils to the wounded areas. Notably, wound closure, extravasation, and neutrophil recruitment were found to be normal in MC-reconstituted KitW/Kit W-v mice. Therefore, we examined whether MCs promote wound healing by releasing histamine or TNF-α. Interestingly, wound closure was reduced in mice treated with an H1-receptor antagonist but not after treatment with an H2-receptor antagonist or in the absence of TNF-α. Taken together, our findings indicate that MC activation and histamine release are required for normal cutaneous wound healing.
ASJC Scopus subject areas
- Molecular Biology