Collagen-dependent growth suppression and changes in the shape of human dermal fibroblasts

This study was designed to investigate the effects of collagen on the growth and cellular shape of cultured human fibroblasts. The fibroblasts grown in the presence of collagen assumed a slim, rod-like form with abundant cytoplasmic protrusions, while the cells on a plain dish showed flat forms with fewer cytoplasmic protrusions. Incorporation of [3H]thymidine was remarkably suppressed in the cells grown on collagen when compared with the fibroblasts on the plain dish. Specific cellular shape and suppressed DNA synthesis showed dependence on the steric conformation of native collagen, because collagen-specific effects on fibroblasts were completely abolished when 60% of the helix content was lost by heat denaturation. These collagen-dependent features of the cells disappeared when the collagen-containing medium was treated with bacterial collagenase. Growth of fibroblasts in contact with collagen was suppressed as compared to that on the plastic dish. These results indicate the importance of the native conformation of collagen in the interaction of collagen and fibroblasts.