Dexamethasone and fetal calf serum effects in differentiation of Vero cells cultured on type I collagen gel.

Vero cells, a fibroblastic cell line, were cultured on a collagen I gel without fetal calf serum (FCS), with the addition of 10% FCS, 10% FCS plus dexamethasone (DEX) or 20% FCS. Our objective was to determine the effects of DEX on the differentiation pattern of fibroblastic cells cultured on a collagen substrate. We found that cells cultured with or without 10% FCS were capable of migrating into the collagen matrix. Near the cells in the gel, we found the deposition of extracellular granulations. Cytochemical data suggests that this material is glycosaminoglycans and/or proteoglycans. Surrounding the cells, a fibronectin deposition was found in the collagen. Thus, these cells make up a structure similar to a loose connective tissue. On the other hand, cells cultured with 10% FCS plus DEX or with 20% FCS did not invade the collagen matrix but formed multiple cell layers poor in fibronectin. On collagen I gel surface, we found an acellular layer rich in collagen IV, which appeared between the cells and the substrate. Thus, DEX or 20% FCS, furnished to the cells cultured on a collagen gel, block cell migration into the substrate and induce them to produce a basement membrane-like structure.