To assess the migratory response of fibroblasts in vitro, normal human dermal fibroblasts (NHDF) were cultured in the presence of
L-ascorbic acid 2-phosphate to induce a multilayered structure. Round
wounds were made by punching, and the migratory response was evaluated by counting the number of migrating cells in the wounded areas.
Collagenase activity in the culture-medium was then measured. When the
wound model was treated with bFGF,
IL-1 alpha or PDGF, the migratory response was facilitated with increased
collagenase secretion. In contrast, treatment with
TGF-beta reduced the migratory response and
collagenase secretion. Since the multilayered structure is rich in collagenous matrix, degradation of the matrix by secreted
collagenase is probably necessary for the cells to migrate into the wounded areas. Furthermore,
malotilate, which is now under development as an agent for
wound therapy, facilitated the migratory response of NHDF with increased
collagenase secretion in this
wound model, suggesting that the wound healing effect of
malotilate is in part attributable to stimulated migration of fibroblasts to wounded areas subsequent to extracellular matrix-degradation.