Angiopoietin-1, angiopoietin-2 and Tie-2 receptor expression in human dermal wound repair and scarring

Summary Background The angiopoietin (Ang)/Tie‐2 ligand/receptor system is known to interact with the vascular endothelial growth factor (VEGF) pathway to determine the fate of blood vessels during angiogenesis. However, the precise contribution of this system to angiogenesis and the mechanisms of vascular maturation and remodelling in human tissue repair have yet to be elucidated. Objectives To examine the spatial and temporal expression of Ang‐1, Ang‐2, Tie‐2 and VEGF in relation to angiogenesis in human surgical wounds. Methods Punch biopsies were taken either from normal unwounded skin (controls) during surgery or from mastectomy scars between 3 days and 2 years postsurgery. Ang‐1, Ang‐2, Tie‐2 and VEGF fibroblast/myofibroblast and endothelial expression were characterized by immunohistochemistry, analysed semiquantitatively and correlated with microvessel density (MVD) and scar age. Results The expression of VEGF, Ang‐1, Ang‐2 and Tie‐2 in fibroblasts/myofibroblasts was increased significantly in early scars, decreased in older scars and was related to scar age (P