[The dynamics of cytokines and their related substances in skin wounds]

Molecular-pathological study on cytokines and their related substances in skin wound healing was performed from the view points of forensic pathology; 1. The dynamics of inflammatory cytokines such as interleukin (IL)-1 alpha, IL-1 beta, IL-6 and tumor necrosis factor-alpha (TNF alpha) during murine wound healing was examined at the levels of protein and mRNA. As for the results, the production of those inflammatory cytokines could be considered as one of the local vital reactions after wounding, and it was clarified that those inflammatory cytokines were one of the biological markers for forensic wound age determination. Practically, our immunohistochemical and morphometrical study with human skin wounds with different wound ages suggested that the ratios of IL-1 alpha-positive cells, considerably exceeding 30%, indicated a postinfliction interval of 1 day or less. 2. In mouse skin incision, a significant increase in IL-10 mRNA occurred between 30 and 180 min. The increased expression of IL-10 mRNA could be considered a vital reaction in skin wounds. Furthermore, it was clarified that IL-10 may have an important regulatory role in limiting the extent and duration of inflammatory response during skin wound healing. 3. Fas and Fas ligand (Fas L) were immunohistochemically detectable on macrophages and fibroblasts in skin wound healing process. Morphometrically, the number of cell expressing Fas and/or Fas L reached a peak at 6 days after wounding. Therefore, it is considered that apoptosis through Fas and Fas L may play an important role for reducing the cellularity during proliferative phase of wound healing in mice.