Cell-substratum interactions trigger key signaling pathways that modulate growth control and tissue-specific gene expression. We have previously shown that abolishing adhesive interactions by suspension culture results in G(0) arrest of myoblasts. We report that blocking intracellular transmission of adhesion-dependent signals in adherent cells mimics the absence of adhesive contacts. We invest...

After platelet activation, fibrinogen mediates platelet-platelet interactions leading to platelet aggregation. In addition, fibrinogen can also function as a cell adhesion molecule, providing a substratum for adhesion of platelets and endothelial cells. In this report, we studied the adhesion of platelets to surface-immobilized fibrinogen under flow in different shear rates. Heparinized whole b...

Adherence to a substratum is a characteristic feature of monocyte-macrophages which may be required for several effector functions. Human peripheral blood monocytes selected by adherence were found to readhere preferentially at 1 h to fibronectin or to a biological matrix. There was then a progressive decrease in the number of adherent cells, and by 48 h only 8-20% of monocytes remained adheren...

Localized expression of environmental cues is thought to provide directional information to migrating neuronal growth cones by enhancing or suppressing axon outgrowth over limited regions. To investigate how such a mechanism may function in vivo, we observed growth cones of embryonic chick dorsal root ganglion neurons at a substratum border between the extracellular matrix components laminin an...

Embryonal chick neural retina cells release into the culture medium a complex of proteins and glycosaminoglycans, termed adherons, that promote cell to substratum adhesion. A monoclonal antibody (C1H3) blocks adheron-mediated cell to substratum adhesion and specifically binds to a 170,000-mol-wt protein present in retinal adherons (Cole, G.J., and L. Glaser, 1984, J. Biol. Chem., 259:4031-4034)...

The cell-substratum interaction was studied in cultures of osteoclasts isolated from the medullary bone of laying hens kept on low calcium diet. In fully spread osteoclasts, cell-substratum adhesion mostly occurred within a continuous paramarginal area that corresponded also to the location of a thick network of intermediate filaments of the vimentin type. In this area, regular rows of short pr...

We have studied the distribution of the plasminogen activator inhibitor type 1 (PAI-1) in cultures of confluent human umbilical vein endothelial cells. Plasminogen activator inhibitor activity measured by the 125I-fibrin plate assay was detected in the cytosol (2.85 +/- 0.16 U), 100,000 g particulate fraction (1.26 +/- 0.30 U), and in the growth substratum (9.82 +/- 1.80 U). Characterization of...

Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often explained by its preferences for conspecifics, though direct evidence for such preferences has been rather limited so far. We studied the reactions of zebra mussels to conspecifics, ...

The crawling motion of Dictyostelium discoideum on substrata involves a number of coordinated events including cell contractions and cell protrusions. The mechanical forces exerted on the substratum during these contractions have recently been quantified using traction force experiments. Based on the results from these experiments, we present a biomechanical model of the contraction phase of Di...

The crawling motion of Dictyostelium discoideum on substrata involves a number of coordinated events including cell contractions and cell protrusions. The mechanical forces exerted on the substratum during these contractions have recently been quantified using traction force experiments. Based on the results from these experiments, we present a biomechanical model of Dictyostelium discoideum mo...