Translational lessons from scarless healing of cutaneous wounds and regenerative repair of the myocardium

Regenerative healing is the process by which injured tissues are restored to their original structure and function. Many species are capable of healing in this manner. However, in mammals the healing response in most tissues is marked by fibroblast proliferation and scar tissue deposition. While scarring contributes to efficient resolution of mammalian wounds and restoration of at least partial structural and functional support, the final result of scar formation can be more deleterious than the initial insult. This is especially true in the heart, which is sensitive to electrical heterogeneities and altered mechanical properties produced by scarring. Several therapeutic modalities promoting regeneration in skin wounds have been developed that modulate various aspects of the healing process. Targets include cytokine stimulation, control of fibroblast activation, modulation of gap junctions, and stem cell differentiation. Here, we review and compare mechanisms of injury, repair, and scarring in the skin and heart and discuss the promise and caveats of future therapies that may translate to improving repair of myocardial tissues. (C) 2009 Elsevier Ltd. All rights reserved.