Fibronectins in healing incision, excision and laser wounds

The distribution of extracellular matrix (ECM) glycoproteins, fibronectins (FNs), was studied in healing scalpel incision, excision and laser wounds of rat tongue dorsal mucosa over a healing period of 42 days by indirect immunofluorescence microscopy using mono- and polyclonal antibodies. A monoclonal antibody (Mab) DH1 was used to detect extradomain-A containing cellular fibronectin (ED-AcFN), and a polyclonal antiserum was utilized to recognize all forms of FNs. In normal tissue ED-AcFN was confined only to the endothelia of larger blood vessels whereas in healing wounds abundant immunoreactive deposits were found in regenerating connective tissue and endothelia of capillaries. The increased content of FNs revealed with both antibodies subsided later on during healing. The results suggest that the locally produced ED-AcFN is essential for tissue regeneration and plays a distinct functional role during wound healing. Laser treatment did not affect the ability of wound fibroblasts to synthesize and deposit cFN. The results provide further evidence that certain embryonic characteristics are seen in regenerating tissue.