Phenotypic modulation and elastin formation of cultured aortic smooth muscle cells grown on and within collagen gels

Aortic smooth muscle cells (SMC) were grown on and within collagen gels and their phenotype and elastin formation were examined. Cells grown on the gels showed multilayer growth with nodule formation. They contained many ribosomes and microfilament bundles with dense bodies. In contrast, cells grown within collagen gels did not form nodules. When collagen gels containing SMC were manually detached from the culture dish, the cells were found to be of the synthetic phenotype with well-developed rough endoplasmic reticulum (ER) and Golgi complexes, but few microfilament bundles. There were numerous elastin deposits in the intercellular spaces. Our findings suggest that the physical property of the substrate affects the phenotype and function of the SMC.