GROWTH-FACTORS IN WOUND-HEALING

The process of wound healing is, in part, orchestrated-by the release of and response to peptide mediators. These macromolecules are released by platelets, leukocytes, and local tissue stores upon initial injury to stimulate the migration and proliferation of new connective tissue, blood vessels, and epithelium into the injury site. As inflammation proceeds to tissue replacement, local expression of these growth factors controls the rate and extent of repair. Since these proteins are all distinct gene products, elaborate regulation can occur at the cellular level. In addition, many growth factors are produced in latent forms or linked to carrier molecules. Growth factors can be released from the extracellular matrix during its turnover, and they can be sequestered by newly-deposited matrix. These potent molecules are involved in normal and pathologic healing, and there are substantial experimental data demonstrating their ability to alter the rate of repair. Similarly, specific growth factor antagonists can reveal much about their action and their role in excessive healing responses such as fibrosis.