Plasma fibronectin concentrations up to 85 mg/100 ml were found in hyperthyroid patients. There was a significant correlation between free thyroxine index and plasma fibronectin values. Hypothyroid patients had low to normal fibronectin concentrations. Parallel decreases of thyroid hormones and plasma fibronectin concentrations were noted during treatment with thiamazole. A direct effect of thy...

We report the effect of Fab' (anti-60k) to a 60,000 mol wt gelatin binding domain of fibronectin (1981, J. Biol. Chem. 256:5583) on diploid fibroblast (IMR-90) extracellular fibronectin and collagen organization. Anti-60k Fab' did not inhibit IMR-90 attachment or proliferation in fibronectin-depleted medium. Fibroblasts cultured with preimmune Fab' deposited a dense extracellular network of fib...

Fibronectin was not removed from the substratum beneath focal adhesion sites when fibroblasts spread in serum-free medium on adsorbed fibronectin substrata, or when fibroblasts spread in serum-containing medium on covalently cross-linked fibronectin substrata. Under these conditions, there was colocalization between 140-kD fibronectin receptors and focal adhesion sites. It was concluded that re...

The distribution of fibronectin and 140 Kd fibronectin-receptor was examined in the truncus arteriosus of the chick embryonic heart during aortico-pulmonary (AP) septation by immunohistochemistry. In 4-day-old chick embryos, immunoreactivity of both anti-fibronectin and anti-140 Kd fibronectin-receptor was seen in the primordia of the AP septum. In 5-day-old embryos, cells stained with anti-140...

Fibronectin binding sites on cultured human fibroblasts were localized by high voltage electron microscopy using either 5- or 18-nm colloidal gold beads (Au5 or Au18) bound to intact fibronectin, the 70-kD amino-terminal fragment of fibronectin that blocks incorporation of exogenous fibronectin into extracellular matrix, or 160-180-kD fragments of fibronectin with cell adhesion and heparin-bind...

Soluble fibronectin is found in body fluids and media of adherent cultured cells and binds to fibrin and collagen. Insoluble fibronectin is found in tissue stroma and in extracellular matrices of cultured cells. Fibronectin is a substrate for Factor XIIIa (plasma transglutaminase) and can be cross-linked by Factor XIIIa to itself and the the alpha-chain of fibrin. We used sodium dodecyl sulfate...

To test the hypothesis that the pericellular fibronectin matrix is involved in mechanotransduction, we compared the response of normal and fibronectin-deficient mouse fibroblasts to cyclic substrate strain. Normal fibroblasts seeded on vitronectin in fibronectin-depleted medium deposited their own fibronectin matrix. In cultures exposed to cyclic strain, RhoA was activated, actin-stress fibers ...

The binding of bacteria or bacterial products to host proteins of tissue extracellular matrix may be a mechanism of tissue adherence. We investigated interactions of the plasmid-encoded outer membrane protein YadA, which confers pathogenic functions on enteropathogenic yersiniae, with fibronectin. Attachment of YadA-positive and YadA-negative recombinant Yersinia enterocolitica strains to carti...

The interaction between human fibronectin and 17 strains of staphylococci was studied in an attempt to elucidate the staphylococcal cell wall component(s) involved in fibronectin binding and to determine the influence of fibronectin upon phagocytosis by three types of phagocytic cells. Purified, radiolabeled fibronectin bound to a similar degree to six laboratory strains and three fresh clinica...

We describe the effect of activated Factor XIII (Factor XIIIa, plasma transglutaminase) on the incorporation of plasma fibronectin into extracellular matrix by cultured human fibroblasts. In the absence of added Factor XIIIa, fibronectin binds to cultured fibroblast cell layers and is assembled into disulfide-bonded multimers of the extracellular matrix. When Factor XIIIa was included in the bi...