Glial cells express N-CAM/D2-CAM-like polypeptides in vitro

• Published in: Nature (London) 1985-08, Vol.316 (6030), p.725-728
• Main Authors: Noble, Mark, Albrechtsen, Merete, Møllert, Claus, Lyles, Joan, Bock, Elisabeth, Goridis, Christo, Watanabe, Michiko, Rutishauser, Urs
• Format: Article
• Language: English
• Subjects: Animals; Antigens, Surface - analysis; Antigens, Surface - immunology; Astrocytes - analysis; Cell Adhesion Molecules; cortex; Epitopes - analysis; glial cells; Humanities and Social Sciences; immunohistochemistry; In Vitro Techniques; letter; Mice; Molecular Weight; multidisciplinary; neural cell adhesion molecule; Neuroglia - analysis; Rabbits; Rats; Schwann Cells - analysis; Science; Science (multidisciplinary)
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/316725a0

The joining together of neurites to form fascicles and the growth of axons along glial surfaces 1,2 during early development suggest that neurone–neurone and neurone–glial adhesion interactions are of considerable importance for defining nerve tracts. In vitro studies have indicated that adhesion between neurones 3–5 involves a glycoprotein that has been independently studied under the names of N-CAM (for neural cell adhesion molecule 6–8 ), D2-CAM 9 and BSP-2 (refs 10, 11). As N-CAM/D2-CAM appears to be a homophilic ligand 12 that binds to N-CAM/D2-CAM polypeptide on adjacent cells, this glycoprotein is potentially important in adhesion interactions between any two N-CAM/D2-CAM-expressing cells. While it has been suggested that neurone–glial adhesion involves molecules other than N-CAM/D2-CAM 13–15 , it is known that N-CAM/D2-CAM antigenic determinants are expressed by glial cells in vivo 16,17 and that injection of anti-N-CAM antibodies into the eye-cup of chick embryos disrupts normal patterns of neuritic apposition to glial endfeet in the developing optic stalk 17 . Do the molecules expressed by glia share restricted antigenic determinants, or binding domains, with N-CAM/D2-CAM, or are N-CAM/D2-CAM polypeptides expressed by glia? Here we present immunocytochemical evidence which suggests that all classes of macroglia express N-CAM/D2-CAM antigenic determinants on their surfaces and immunochemical analyses which indicate that the molecules expressed by purified astrocytes are closely similar, or identical, to at least some forms of N-CAM/D2-CAM obtained from whole brain or purified neurones. However, our results also suggest that different N-CAM/D2-CAM polypeptides may be separately expressed by neurones and astrocytes.