Figure 1.
Schematic representation of cell types involved in wound healing and the potential effects of S100A8/A9 on those cells. In neutrophils, S100A8/A9 promote expression of inflammatory mediators, phagocytosis, oxidative burst and migration through the epithelium. Likewise, in monocytes, S100A8/A9 stimulate migration and an inflammatory phenotype. Macrophages express and release significantly less S100A8/A9 than do monocytes. Keratinocytes express S100A8/A9 following exposure to inflammatory stimuli, and S100A8/A9 expression results to decreased proliferation, enhanced ROS generation, differentiation and migration as well as increased expression of proinflammatory cytokines and matrixmetalloproteinase-9. When added exogenously, S100A8/A9 promote proliferation of keratinocytes and fibroblasts, which might contribute to the proliferative phase. Thus, S100A8/A9 affect the major cell types involved in wound healing, and these proteins have cell type-selective effects.
