What role do macrophages play in wound healing?
Macrophages play a critical role in the inflammatory phase. They help to débride the wound through phagocytosis, but, more importantly, they are the primary source of proinflammatory cytokines and growth factors such as the interleukins (IL-1, IL-6, IL-8), PDGF, TGF-β, epidermal growth factor (EGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). These humoral factors stimulate the recruitment, activation, and proliferation of additional macrophages, lymphocytes, fibroblasts, and endothelial cells. These cytokines also act in an autocrine fashion to tremendously amplify their expression.