Fibroblast Growth Factor Modulates Synthesis of Collagen in Cultured Vascular Endothelial Cells

Vascular endothelial cells derived from adult bovine aortic arch can be grown in two ways, either in the presence or absence of fibroblast growth factor. The types of collagen produced by cultures under these two con‐ ditions have been compared. In the presence of fibroblast growth factor, cells grow in an orderly fashion, express their normal phenotype and synthesize primarily type III collagen plus collagens types IV and V at a ratio of 10: 1: 3. Cultures grown in the absence of the factor lose their orderly pattern of growth, lose polarity and normal phenotypic expression. They devote twice the proportion of total protein‐synthesizing capacity to collagen, and now synthesize type I in addition to the other collagen types. The ratio of collagen types I: III: IV: V is approxi‐ mately 30:70:1:13. The kinds of type V collagen chains expressed are also altered. Fibroblast growth factor appears to modulate collagen synthesis, the major component of the extracellular matrix, and indirectly modulates the phenotypic expression of cultured vascular endothelial cells. In atherosclerosis, type I collagen is found in association with the intimal layer. The disorderly growth and the abnormal production of type I collagen by these vascular endothelial cells cultured in the absence of fibroblast growth factor is a model for a number of pathological situations including atherosclerotic plaque formation.