Abstract
Disruptive effects of calcium upon neurofilaments and glial filaments were studied in white matter of rat optic nerve and spinal cord and in rat peripheral nerve. Filament ultrastructure and tissue protein composition were compared following a calcium influx into excised tissues. A calcium influx was induced by freeze-thawing tissues in media containing calcium (5 mM) while control tissues were freeze-thawed in the presence of EGTA (5 mM). Experimental and control tissues were either fixed by immersion in glutaraldehyde and processed for electron microscopic examination or homogenized in a solubilizing buffer and analyzed for protein content by SDS-polyacrylamide gel electrophoresis. Morphological studies showed that calcium influxes led to the loss of neurofilaments and glial filaments and to their replacement by an amorphous granular material. These morphological changes were accompanied by the loss of neurofilament triplet proteins and glial fibrillary acidic (GFA) protein from whole-tissue homogenates. In addition, a calcium-sensitive 58,000-mol-wt protein was identified in rat optic and peripheral nerve. The findings indicate the widespread occurrence of neurofilament proteolysis following calcium influxes into CNS and PNS tissues. The parallel breakdown of glial filaments and loss of GFA protein subunits suggest the presence of additional calcium-activated proteases(s) in astroglial cells.
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Anderton, B. H., Ayers, M., andThorpe, R. 1978. Neurofilaments from mammalian central and peripheral nerve share certain polypeptides. FEBS Lett. 103:148–151.
Dahl, D., andBignami, A. 1973. Immunochemical and immunofluorescence studies of the glial fibrillary acidic protein in vertebrates. Brain Res. 61:279–293.
Davison, P. F., andWinslow, B. 1974. The protein subunit of calf brain neurofilament, J. Neurobiol. 5:119–133.
Eng, L. F., Vanderhaeghen, J. J., Bignami, A., andGerstl, B. 1971. An acidic protein isolated from fibrous astrocytes. Brain Res. 28:351–354.
Fields, K. L., andYen, S. H. 1979. Antibodies to neurofilament, glial filament and fibroblast intermediate filament proteins bind to different cell types of the nervous system. Page 131, inCondeelis, J., Satir, P., andBurridge, K. (eds.), The Cytoskeleton: Membranes and Movements, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York.
Franke, W. W., Schmid, E., Osborn, M., andWeber, K. 1978. Different intermediatesized filaments distinguished by immunofluorescence microscopy. Proc. Natl. Acad. Sci. U.S.A. 75:5034–5038.
Gard, D. L., Bell, P. B., andLazarides, E. 1979. Coexistence of desmin and the fibroblastic intermediate filament subunit in muscle and non-muscle cells: Identification and comparative peptide analysis. Proc. Natl. Acad. Sci. U.S.A. 76:3894–3898.
Goldman, J. E., Schaumberg, H. H., andNorton, W. T. 1978. Isolation and characterization of glial filaments and neurofilaments from human brain. Similarity of the major protein components. J. Cell Biol. 78:426–440.
Lasek, R. J., andBlack, M. M. 1977. How do axons, stop growing? Some clues from the metabolism of the proteins in the slow component of axonal transport. Pages 161–169,in Roberts, S., Lajtha, A., andGispen, W. H. (eds.), Mechanisms, Regulation and Special Functions of Protein Synthesis in the Brain, Elsevier-North Holland Biomedical Press, Amsterdam.
Lasek, R. J., andHoffman, P. N. 1976. The neuronal cytoskeleton, axonal transport and axonal growth. Pages 1021–1049,in Goldman, R., Pollard, T., andRosenbaum, J. (eds.), Cell Motility, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York.
Igbal, K., Grundke-Igbal, I., Wisniewski, H. M., andTerry, R. D. 1977. On the neurofilament and neurotubule proteins from human autopsy tissue. J. Neurochem. 29:417–424.
Laemmli, U. K. 1970. Cleavage of structural proteins during the assembly of bacteriophage T4. Nature 277:680–685.
Lazarides, E. 1980. Intermediate filaments as mechanical integrators of cellular space. Nature 283:249–256.
Lee, V., Yen, S.-H., andShelanski, M. L. 1977. Biochemical correlates of astrocytic proliferation in the mutant Staggerer mouse. Brain Res. 128:389–392.
Liem, R. K. H., Yen, S. H., Salomon, G. D., andShelanski, M. L. 1978. Intermediate filaments in nervous tissue. J. Cell Biol. 79:637–645.
Lucus, C. V., Bensch, K. G., andEng, L. F. 1980. In vitro polymerization of glial fibrillary acidic (GFA) protein extracted from multiple sclerosis (ms) brain. Neurochem. Res. 5:247–255.
Micko, S., andSchlaepfer, W. W. 1978. Protein composition of axons and myelin from rat and human peripheral nerves. J. Neurochem. 30:1041–1049.
Micko, S., andSchlaepfer, W. W. 1978. Metachromasy of peripheral nerve collagen on polyacrylamide gels stained with Coomassie brilliant blue R-250. Anal. Biochem. 88:566–572.
Rodriguez-Echandia, E. L., andPiezzi, R. S., 1968. Microtubules in the nerve fibers of the toadBufa aremarum Hensel. J. Cell Biol. 39:491–497.
Rueger, D. C., Huston, J. S., Dahl, D., andBignami, A., 1979. Formation of 100 Å filaments from purified glial fibrillary acidic protein in vitro. J. Mol. Biol. 135:53–68.
Schachner, M., Hedley-Whyte, E. T., Hsu, D. W., Schoonmaker, G., andBignami, A.. Ultrastructural localization of glial fibrillary protein in mouse cerebellum by immunoperoxidase labeling. J. Cell Biol. 75:67–73.
Schlaepfer, W. W. 1974. Calcium-induced degeneration of axoplasm in isolated segments of rat peripheral nerve. Brain Res. 69:203–215.
Schlaepfer, W. W. 1974. Effects of energy deprivation on Wallerian degeneration in isolated segments of rat peripheral nerve. Brain Res. 78:71–81.
Schlaepfer, W. W. 1974. Structural alterations of peripheral nerve induced by the calcium ionophore, A23187. Brain Res. 136:1–9.
Schlaepfer, W. W., andBunge, R. P. 1973. The effects of calcium ion concentration on the degeneration of amputated axons in tissue culture. J. Cell Biol. 59:456–470.
Schlaepfer, W. W., andFreeman, L. A. 1978. Neurofilament proteins of rat peripheral nerve and spinal cord. J. Cell Biol. 78:653–662.
Schlaepfer, W. W., andFreeman, L. A. 1980. Calcium-dependent degradation of mammalian neurofilaments by soluble tissue factor(s) from rat spinal cord. Neuroscience 5:2305–2314.
Schlaepfer, W. W., Freeman, L. A., andEng, L. F. 1979. Studies of human and bovine spinal nerve roots and the outgrowth of CNS tissue into the nerve root entry zone. Brain Res. 177:219–229.
Schlaepfer, W. W., andHasler, M. B. 1979. Characterization of the calcium-induced disruption of neurofilaments in rat peripheral nerve. Brain. Res. 168:299–309.
Schlaepfer, W. W., andLynch, R. G. 1977. Immunofluorescence studies of neurofilaments in the rat and human peripheral and central nervous system. J. Cell Biol. 74:241–250.
Schlaepfer, W. W., andMicko, S. 1978. Chemical and structural changes of neurofilaments in transected rat sciatic nerve. J. Cell Biol. 78:369–378.
Schlaepfer, W. W., andMicko, S. 1979. Calcium-dependent alterations of neurofilament proteins of rat peripheral nerve. J. Neurochem. 32:211–219.
Schlaepfer, W. W., andZimmerman, U. J. P. 1980. Calcium-dependent breakdown of glial filaments in rat optic nerve and spinal cord. J. Neuropathol. Exp. Neurol. 39:388.
Schook, W. J., andNorton, W. T. 1975. On the composition of axonal neurofilaments. Trans. Am. Soc. Neurochem. 1:214.
Shay, J., andGonatas, N. K. 1973. Electron microscopy of cat spinal subject to circulatory arrest and deep local hypothermia (15c). Am. J. Pathol. 72:369–396.
Shelanski, M. L., Albert, S., DeVries, G. H., andNorton, W. T. 1971. Isolation of filaments from brain. Science 174:1242–1245.
Uyeda, C. T., Eng, L. F., andBignami, A. 1972. Immunological study of the glial fibrillary acidic protein. Brain Res. 37:81–89.
Wuerker, R. B., andKirkpatrick, J. B. 1972. Neuronal microtubules, neurofilaments microfilaments. Int. Rev. Cytol. 33:45–75.
Yen, S. H., Dahl, D., Schachner, M., andShelanski, M. L. 1976. Biochemistry of the filaments of brain. Proc. Natl. Acad. Sci. U.S.A. 73:529–533.
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Schlaepfer, W.W., Zimmerman, UJ.P. Calcium-mediated breakdown of glial filaments and neurofilaments in rat optic nerve and spinal cord. Neurochem Res 6, 243–255 (1981). https://doi.org/10.1007/BF00964040
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DOI: https://doi.org/10.1007/BF00964040