Apolipoprotein E associated with astrocytic glia of the central nervous system and with nonmyelinating glia of the peripheral nervous system.
Open Access
- 1 October 1985
- journal article
- research article
- Published by American Society for Clinical Investigation in JCI Insight
- Vol. 76 (4), 1501-1513
- https://doi.org/10.1172/jci112130
Abstract
The plasma protein apolipoprotein (apo) E is an important determinant of lipid transport and metabolism in mammals. In the present study, immunocytochemistry has been used to identify apo E in specific cells of the central and peripheral nervous systems of the rat. Light microscopic examination revealed that all astrocytes, including specialized astrocytic cells (Bergmann glia of the cerebellum, tanycytes of the third ventricle, pituicytes of the neurohypophysis, and Müller cells of the retina), possessed significant concentrations of apo E. In all of the major subdivisions of the central nervous system, the perinuclear region of astrocytic cells, as well as their cell processes that end on basement membranes at either the pial surface or along blood vessels, were found to be rich in apo E. Extracellular apo E was present along many of these same surfaces. The impression that apo E is secreted by astrocytic cells was confirmed by electron microscopic immunocytochemical studies, which demonstrated the presence of apo E in the Golgi apparatus. Apo E was not present in neurons, oligodendroglia, microglia, ependymal cells, and choroidal cells. In the peripheral nervous system, apo E was present within the glia surrounding sensory and motor neurons; satellite cells of the dorsal root ganglia and superior cervical sympathetic ganglion as well as the enteric glia of the intestinal ganglia were reactive. Apo E was also present within the non-myelinating Schwann cells but not within the myelinating Schwann cells of peripheral nerves. These results suggest that apo E has an important, previously unsuspected role in the physiology of nervous tissue.Keywords
This publication has 53 references indexed in Scilit:
- Molecular identity, distribution and heterogeneity of glial fibrillary acidic protein: an immunoblotting and immunohistochemical study of Schwann cells, satellite cells, enteric glia and astrocytesJournal of Neurocytology, 1984
- Apoprotein E is synthesized and secreted by resident and thioglycollate-elicited macrophages but not by pyran copolymer- or bacillus Calmette-Guerin-activated macrophages.The Journal of Experimental Medicine, 1983
- Onset of apoprotein E secretion during differentiation of mouse bone marrow-derived mononuclear phagocytes.The Journal of cell biology, 1983
- Fibronectin in the microvasculature: localization in the pericyte-endothelial interstitiumJournal of Ultrastructure Research, 1983
- Lipoprotein receptors and cholesterol homeostasisBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1983
- Regulation of Hepatic Lipoprotein Receptors in the Dog. RAPID REGULATION OF APOLIPOPROTEIN B,E RECEPTORS, BUT NOT OF APOLIPOPROTEIN E RECEPTORS, BY INTESTINAL LIPOPROTEINS AND BILE ACIDSJCI Insight, 1983
- Two independent lipoprotein receptors on hepatic membranes of dog, swine, and man. Apo-B,E and apo-E receptors.JCI Insight, 1981
- Effects of an atherogenic diet on apolipoprotein E biosynthesis in the ratBiochemistry, 1981
- Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.Proceedings of the National Academy of Sciences of the United States of America, 1979
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970