The influence of corneal stromal matrix proteins on the migration of humancorneal fibroblasts

Motivated by the alterations seen in the corneal matrix composition after p hotorefractive keratectomy and the migration of corneal keratocytes seen fo llowing this procedure. the locomotor response of corneal stromal fibroblas ts to various extracellular matrix proteins was determined. In addition. th e involvement of integrin mediated attachment to the matrix proteins was in vestigated. Quantitative invasion assays were performed using collagen gels , supplemented with either fibronectin, tenascin, collagen type V, collagen type VI, chondroitin sulfate or keratan sulfate, The ultrastructure of the gels was visualized by scanning electron microscopy and related to the mig ration results. The extent of alpha(1)beta(1), alpha(2)beta(1), alpha(3)bet a(1) and alpha(5)beta(1) integrin mediated attachment to the matrix protein s was evaluated using blocking antibodies. Fibronectin increased corneal fi broblast migration significantly, and served as an excellent substrate for cellular attachment, mediated by the alpha(5)beta(1) integrin. Addition of tenascin to the fibronectin-containing gels disrupted these effects, while attachment to this matrix also involved the integrins alpha(2)beta(1) and a lpha(3)beta(1) Chondroitin sulfate and collagen types V and VI primarily al tered the structure of the collagen matrix, resulting in an inhibition of m igration by the collagens and an increase by chondroitin sulfate. They all served as poor substrates for attachment. Thus, the migratory activity of c orneal fibroblasts in vitro is influenced by the composition of the surroun ding extracellular matrix, either by integrin mediated cell-matrix interact ions or through matrix-matrix interactions. This study provides evidence th at the provisional matrix deposited in a corneal stromal wound may facilita te the entry of migrating corneal fibroblasts. (C) 2000 Academic Press.