CELL-ADHESION TO EXTRACELLULAR-MATRIX IS DIFFERENT IN MARINE HYDROZOANS COMPARED WITH VERTEBRATES

Extracellular matrices (ECMs) of phylogenetically very distant organis ms were tested for their ability to support cell adhesion, spreading a nd DNA replication in reciprocal xenograft adhesion tests. Mechanicall y dissociated cells of the medusa Podocoryne carnea (Cnidaria, Hydrozo a) were seeded on ECMs of polyps and medusa, and on several ECM glycop roteins or entire ECMs from vertebrates. In reciprocal experiments, ce lls from different vertebrate cell-lines were seeded on ECMs of polyps , medusae and also on electrophoresed and blotted extracts of both typ es of ECMs. The results demonstrate that medusa cells adhere and sprea d on polyp and medusa ECMs but do not recognize vertebrate ECMs or pur ified ECM glycoproteins. Vertebrate cells in contrast adhere, spread a nd proliferate on ECMs of polyps and medusae. The number of attached c ells depends on the cell type, the type of ECM and, in certain cases, on the stage of the cell cycle. Cell adhesion experiments with pretrea ted ECMs of polyps and medusae, e.g. oxidation of carbohydrate residue s with sodium-metaperiodate, or blocking of certain carbohydrate moiet ies with the lectin wheat germ agglutinin or a carbohydrate-specific m onoclonal antibody, demonstrate that ECM carbohydrates are more import ant for cell-ECM interactions of medusa cells than for vertebrate cell s. Furthermore, the experiments indicate that polyp and medusa ECMs co ntain different components which strongly modulate adhesion, spreading and DNA replication of vertebrate cells.