Effects of hydrogen peroxide in a keratinocyte-fibroblast co-culture model of wound healing.

Recently, there has been renewed interest in the role of reactive oxygen species (ROS), especially H(2)O(2), in wound healing. We previously showed that H(2)O(2) stimulates healing in a keratinocyte scratch wound model. In this paper, we used a more complex and physiologically relevant model that involves co-culturing primary keratinocytes and fibroblasts. We found that the two main cell types within the skin have different sensitivities to H(2)O(2) and to the widely used "antioxidant"N-acetyl-l-cysteine (NAC). Keratinocytes were very resistant to the toxicity of H(2)O(2) (250 and 500 μM) or NAC (5 mM). However, the viability of fibroblasts was decreased by both compounds. Using the co-culture model, we also found that H(2)O(2) increases re-epithelialization while NAC retards it. Our data further illustrate the possible role of ROS in wound healing and the co-culture model should be useful for screening agents that may influence the wound healing process.