Different types of ROS-scavenging enzymes are expressed during cutaneous wound repair

Injury to the skin initiates a series of events including inflammation, new tissue formation, and matrix remodeling. During the early inflammatory pha se, polymorphonuclear leukocytes and macrophages infiltrate the wounded tis sue. Once activated, they produce large amounts of reactive oxygen species (ROS) as part of their defense mechanism. Although this process is benefici al, increased levels of ROS can inhibit cell migration and proliferation an d can even cause severe tissue damage. Therefore, cells must develop strate gies for the detoxification of these molecules. To gain insight into the me chanisms which underlie this process, me analyzed the temporal and spatial expression pattern of various ROS-scavenging enzymes during the healing pro cess of full-thickness excisional wounds in mice. Here we demonstrate a str ong mRNA expression of two types of superoxide dismutase (SOD), as well as of catalase, and the selenoenzymes glutathione peroxidase (SeGPx) and phosp holipid hydroperoxide glutathione peroxidase in normal and wounded skin. Mo st importantly mRNA levels of the SODs and of SeGPx increased strongly afte r skin injury. In situ hybridization and immunofluorescence studies reveale d the presence of these transcripts at multiple places in the wound, whereb y particularly high expression levels were detected in the hyperproliferati ve epithelium and the hair follicles at the wound edge. These data suggest an important role of ROS-scavenging enzymes in the detoxification of ROS du ring cutaneous wound repair. (C) 1999 Academic Press.