Regulation of immunoreactive GAP-43 expression in rat cortical macroglia is cell type specific.
Growth-associated protein 43 (GAP-43) is an abundant, intensely investigated membrane phosphoprotein of the nervous system (Benowitz, L.I., and A. Routtenberg. 1987. Trends Neurosci. 10:527-532; Skene, J. H. P. 1989. Annu. Rev. Neurosci. 12:127-156), with a hitherto unknown function. We have previously demonstrated that astrocytes, brain macroglial cells, contain GAP-43 (Steisslinger, H. W., V. J. Aloyo, and L. Vitković, 1987. Brain Res. 415:375-379; Vitković, L., H. W. Steisslinger, V. J. Aloyo, and M. Mersel. 1988. Proc. Natl. Acad. Sci. USA. 85:8296-8300; Vitković L., and M. Mersel. 1989. Metab. Brain Dis. 4:47-53). Results from double immunofluorescent labeling experiments presented here show that oligodendrocytes also contain GAP-43 immunoreactivity (GAP-43ir). Thus, all three macroglial cell types of the central nervous system (type I and type 2 astrocytes and oligodendrocytes) contain GAP-43. Whereas immunoreactive GAP-43 is expressed by progenitors of all macroglial cell types, the developmental regulation of its expression is cell type specific. Immunoreactive GAP-43 is downregulated in type 1 astrocytes, and constitutively expressed in both type 2 astrocytes and oligodendrocytes. These results may be relevant to potential function(s) of GAP-43.
da Cunha
A
A
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Vitković
L
L
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D019922:GAP-43 Protein; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism*; D010750:Phosphoproteins / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013861:Thiocyanates; D013997:Time Factors
D005452:Fluoresceins; D005456:Fluorescent Dyes; D019922:GAP-43 Protein; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D013861:Thiocyanates; D016650:Fluorescein-5-isothiocyanate