Abstract
C-CAM, a transmembrane glycoprotein belonging to the immunoglobulin superfamily, can mediate intercellular adhesion by homophilic, Ca 2+-independent binding. Immunohistochemical analysis of adult rat tissues has demonstrated that C-CAM is expressed in various epithelia, vessel endothelia, and hematopoietic cells. By molecular cloning and sequence analysis several isoforms differing both in the extracellular and the cytoplasmic domains have been found. Here we have analyzed the expression of C-CAM in the developing rat central nervous system. No neuronal expression was observed, but biochemical and immunohistochemical analyses demonstrated that C-CAM becomes expressed in the microvessels from embryonic day E-13; the intensity of the staining increased through day E-15 and then gradually decreased during the perinatal and early postnatal period. The expression of C-CAM in the walls of the microvessels was confirmed by in situ hybridization. Immunoelectron microscopy showed that C-CAM was localized both to the abluminal surface of the endothelial cells and to cellular processes of primordial pericytes where these two cell types are in contact with each other. No staining was found on the luminal endothelial cell surfaces or inter-endothelial cell contact areas. During the perinatal period C-CAM also became expressed on the opposite side of the pericytes and on other cells, possibly astrocytes, in contact with these areas of the pericytes. These observations suggest that C-CAM may be involved in heterotypic, homophilic adhesion between endothelial cells, pericytes and astrocytes, and in maturation of the vessel walls.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.