Proteoglycans have been shown in vitro to bind multiple components of the cellular microenvironment that function during wound healing. To study the composition and function of these molecules when derived from an in vivo source, soluble proteoglycans released into human wound fluid were characterized and evaluated for influence on fibroblast growth factor-2 activity. Immunoblot analysis of wound fluid revealed the presence of syndecan-1, syndecan-4, glypican, decorin, perlecan, and versican. Sulfated glycosaminoglycan concentrations ranged from 15 to 65 g/ml, and treatment with chondroitinase B showed that a large proportion of the glycosaminoglycan was dermatan sulfate. The total glycosaminoglycan mixture present in wound fluid supported the ability of fibroblast growth factor-2 to signal cell proliferation. Dermatan sulfate, and not heparan sulfate, was the major contributor to this activity, and dermatan sulfate bound FGF-2 with K d ‫؍‬ 2.48 M. These data demonstrate that proteoglycans released during wound repair are functionally active and provide the first evidence that dermatan sulfate is a potent mediator of fibroblast growth factor-2 responsiveness.

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We previously reported that a macrophage response that increased binding to 125

Seventy-kilodalton amino-terminal and 180-kDa cell-binding fibronectin fragments were used to determine which fibronectin domains support soluble gelatin interactions with macrophages. At each time measured, intact and 180-kDa fibronectin supported significantly larger quantities of cell-associated gelatin than control levels (P < 0.05). Throughout the time course fibronectin supported more binding than 180 kDa. Seventy kilodalton did not augment gelatin binding until 2 h, but by 6 h 70 kDa supported more binding than intact fibronectin (P < 0.01). This appeared to result from a cellular response initiated by 70-kDa-gelatin interactions with the macrophages. Within 4 h the majority of gelatin associated with cells under control conditions, and in the presence of fibronectin or 180 kDa, was internalized. Seventy-kilodalton-mediated binding remained localized primarily to the cell surfaces at all times. The macrophages partially degraded the internalized and external gelatin fractions. These results demonstrate that intact fibronectin and specific fibronectin fragments support soluble gelatin interactions with macrophages.

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