Incorporation of cellular and plasma fibronectins into smooth muscle cell extracellular matrix in vitro.

AUTOR(ES)

Millis, A J

RESUMO

Fibronectins isolated from the conditioned medium produced by cultures of undifferentiated (monolayer) and differentiated (nodular) swine vascular smooth muscle cells are similar but not identical. In general, the nodular-cell fibronectin has a smaller molecular mass than monolayer-cell fibronectin and appears to lack the COOH-terminal interchain disulfide linkage. We studied the incorporation of cellular and plasma fibronectins into the cell layer. Smooth muscle cells bound 2.5 times more monolayer-cell fibronectin than nodular-cell fibronectin. Polypeptide fragments of human plasma fibronectin were used as a model system to investigate fibronectin incorporation into the cell layer. Only intact molecules were incorporated into the cell layer and subsequently organized into fibers. Polypeptide fragments of molecular mass 205 kDa and 185 kDa were not incorporated even though they retained the collagen-, cell-, and heparin-binding regions. Incorporation appears to require an activity associated with either the NH2-terminal or COOH-terminal domains. We propose that fibronectin activity is lost during differentiation of smooth muscle cells.

Documentos Relacionados

• Permissive effect of the extracellular matrix on cell proliferation in vitro.
• Interaction between synoviocytes and extracellular matrix in vitro.
• Extracellular matrix promotes mammary epithelial growth and differentiation in vitro.
• Incorporation of glucocerebrosidase into Gaucher's disease monocytes in vitro.
• Amino acid incorporation into proteolipid of myelin in vitro.