Cutaneous tissue angiotensin–converting enzyme may participate in pathologic scar formation in human skin

Many studies have shown that up-regulation of angiotensin-converting enzyme (ACE) participates in adverse fibrous remodeling. Although this has become an accepted fact in the cardiovascular field, the relationship between ACE and cutaneous fibrous remodeling, such as keloid or hypertrophic scars, remains unknown. We sought to investigate ACE in normal skin, wounded skin, and pathologic scars. Ten samples undergoing a normal wound-healing process, 14 samples of pathologic scar tissue, and 15 samples of normal skin were used in this study. Cutaneous tissue ACE activities were measured with high-pressure liquid chromatography. Localization of ACE was assessed by immunohistochemistry. The ACE activity in pathologic scar tissue was significantly higher than in normal and wounded skin. Immunohistochemical studies demonstrated that myofibroblasts were stained with anti-ACE antibody. The study is small. These results suggest that up-regulated ACE may participate in cutaneous pathologic scar formation the same as the cardiovascular system.