THE ROLE OF APOPTOSIS IN WOUND-HEALING

Wound healing involves a series of rapid increases in specific cell po pulations that prepare the wound for repair, deposit new matrices and finally, mature the wound. Upon completing their tasks, these specific cell types must be eliminated from the wound prior to the progression to the next phase of healing. The most logical method of cellular dow n-regulation is through apoptosis. Apoptosis allows for the eliminatio ns of entire populations without tissue damage or an inflammatory resp onse. This review discusses which cells dominate the various phases of tissue repair and how the cellular pattern may vary after differing t ypes of injury. The potential mechanisms involved in the down-regulati on of inflammation and fibrosis are also covered. The studies that sup port the hypothesis that apoptosis is involved in the regulation of wo und healing are discussed. The evidence supporting potential cell sign als involved in the induction of apoptosis in tissue repair are examin ed. Finally, the review ends with a presentation of how dysregulation of apoptosis can lead to pathologic forms of healing such as excessive scarring and fibrosis. By understanding the mechanisms controlling ap optosis and tissue repair, one may eventually develop therapeutic moda lities to minimize scarring, a final pathway for many disease processe s. (C) 1998 Elsevier Science Ltd. All rights reserved.