title: Divalent cations and extracellular matrix receptor function during newt epidermal cell migration.
abstract: Skin explants were placed in plastic dishes coated with fibronectin (FN), fibrinogen (FGN) or collagen. Explants were cultured for 16 h in serum-free medium containing calcium (Ca) and magnesium (Mg), or in medium containing either Ca-only, Mg-only or manganese (Mn)-only. In Ca/Mg, migrating keratinocytes on all test substrata produced a sheet of contiguous cells that formed a robust halo around each explant. When Ca was the only divalent cation added, the halos in FN- and FGN-coated dishes were approximately 70-80% as large as in Ca/Mg. On collagen, however, the halos were significantly smaller than on the other two substrata. This substratum-specific response in Ca-only suggests that migration on collagen is fundamentally different than migration on FN and FGN. Halos as large or larger than those in Ca/Mg formed on all three substrata in Mg-only. In this case, the halos were not in the form of a sheet of contiguous cells, but were composed of dissociated cells that had migrated from the explant. Individual cells likewise migrated from explants cultured in medium containing Mn-only; however, these halos were never as large as in Mg-only. Thus, while exogenous Ca appears to be an absolute requirement for maintenance of cell-cell connections, the cell-substratum interactions that lead to migration can utilize either Ca, Mg or, to a lesser extent, Mn. Additionally we found that migration on the generally nonpermissive protein, BSA, was not improved by the presence of Mn.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163.
authors.forename: J T
authors.initials: JT
authors.lastname: Mahan
authors.forename: D J
authors.initials: DJ
authors.lastname: Donaldson
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002465:Cell Movement; D003094:Collagen; D046508:Culture Techniques; D005340:Fibrinogen; D005353:Fibronectins; D007365:Intercellular Junctions / Q000187:drug effects*; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008345:Manganese / Q000494:pharmacology; D009673:Notophthalmus viridescens; D011956:Receptors, Cell Surface / Q000187:drug effects* / Q000502:physiology
chemical_list: D005353:Fibronectins; D011956:Receptors, Cell Surface; C052131:extracellular matrix receptor; D008345:Manganese; D005340:Fibrinogen; D003094:Collagen; D008274:Magnesium; D002118:Calcium