The interaction of vascular endothelial cells and dorsal root ganglion neurites is mediated by vitronectin and heparan sulfate proteoglycans.
The interaction of peripheral nerve and blood vessels during development was studied by using DRG explant culture plated on confluent monolayer of vascular endothelial cells (VEC). The comparison of neurite length on various substrates showed a preference of DRG neurites in the following order; thrombospondin > laminin, vitronectin > fibronectin, VEC monolayer > collagen I, rat astrocyte monolayer. On layers of fibroblasts (3T3) or gliomas (C6), neurite extension was not observed. To identify the neurite outgrowth promoting adhesion molecules on VEC surface, several antibodies and synthetic peptides were added to the culture medium of DRG. With vitronectin antibody or with peptides containing the Arg-Gly-Asp (RGD) sequence, 30-40% of neurite outgrowth was inhibited and these two effects were not additive. Therefore, a part of neurite outgrowth in this system is mediated by vitronectin in RGD dependent manner. Another molecule which promotes neurite outgrowth on VEC was identified by a new monoclonal antibody (MAb) EC1. In the Western blot analysis, the immunoreactive band which was over 400 kDa was intensified by guanidine HCl extraction. EC1 immunoreactive band disappeared after the treatment of heparitinase but not with other glycolyases, indicating that EC1 antigen is heparan sulfate proteoglycan(s). The DRG neurite outgrowth was inhibited by MAb EC1 by about 30-40%. By the combination of MAb EC1 and RGD peptide, the neurite outgrowth in explant culture was inhibited by about 50%, and in DRG dissociated culture nearly 100% inhibition was observed. Thus, for the DRG neurite elongation on VEC, vitronectin and heparan sulfate proteoglycan(s) are playing crucial roles.
Isahara
K
K
Department of Physiology, University of Tsukuba, Ibaraki, Japan.
Yamamoto
M
M
D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology*; D005727:Ganglia, Spinal / Q000502:physiology*; D006023:Glycoproteins / Q000494:pharmacology*; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D007150:Immunohistochemistry; D016501:Neurites / Q000502:physiology*; D011509:Proteoglycans; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine; D019096:Vitronectin
D006023:Glycoproteins; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D011509:Proteoglycans; D019096:Vitronectin