Neurochemical Research

, Volume 6, Issue 3, pp 243–255 | Cite as

Calcium-mediated breakdown of glial filaments and neurofilaments in rat optic nerve and spinal cord

  • William W. Schlaepfer
  • Un-Jin P. Zimmerman
Original Articles


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.


Spinal Cord Peripheral Nerve Glial Fibrillary Acidic Protein Granular Material Calcium Influx 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Anderton, B. H., Ayers, M., andThorpe, R. 1978. Neurofilaments from mammalian central and peripheral nerve share certain polypeptides. FEBS Lett. 103:148–151.Google Scholar
  2. 2.
    Dahl, D., andBignami, A. 1973. Immunochemical and immunofluorescence studies of the glial fibrillary acidic protein in vertebrates. Brain Res. 61:279–293.PubMedGoogle Scholar
  3. 3.
    Davison, P. F., andWinslow, B. 1974. The protein subunit of calf brain neurofilament, J. Neurobiol. 5:119–133.PubMedGoogle Scholar
  4. 4.
    Eng, L. F., Vanderhaeghen, J. J., Bignami, A., andGerstl, B. 1971. An acidic protein isolated from fibrous astrocytes. Brain Res. 28:351–354.PubMedGoogle Scholar
  5. 5.
    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.Google Scholar
  6. 6.
    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.PubMedGoogle Scholar
  7. 7.
    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.PubMedGoogle Scholar
  8. 8.
    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.PubMedGoogle Scholar
  9. 9.
    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.Google Scholar
  10. 10.
    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.Google Scholar
  11. 11.
    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.PubMedGoogle Scholar
  12. 12.
    Laemmli, U. K. 1970. Cleavage of structural proteins during the assembly of bacteriophage T4. Nature 277:680–685.Google Scholar
  13. 13.
    Lazarides, E. 1980. Intermediate filaments as mechanical integrators of cellular space. Nature 283:249–256.PubMedGoogle Scholar
  14. 14.
    Lee, V., Yen, S.-H., andShelanski, M. L. 1977. Biochemical correlates of astrocytic proliferation in the mutant Staggerer mouse. Brain Res. 128:389–392.PubMedGoogle Scholar
  15. 15.
    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.PubMedGoogle Scholar
  16. 16.
    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.PubMedGoogle Scholar
  17. 17.
    Micko, S., andSchlaepfer, W. W. 1978. Protein composition of axons and myelin from rat and human peripheral nerves. J. Neurochem. 30:1041–1049.PubMedGoogle Scholar
  18. 18.
    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.PubMedGoogle Scholar
  19. 19.
    Rodriguez-Echandia, E. L., andPiezzi, R. S., 1968. Microtubules in the nerve fibers of the toadBufa aremarum Hensel. J. Cell Biol. 39:491–497.PubMedGoogle Scholar
  20. 20.
    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.PubMedGoogle Scholar
  21. 21.
    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.Google Scholar
  22. 22.
    Schlaepfer, W. W. 1974. Calcium-induced degeneration of axoplasm in isolated segments of rat peripheral nerve. Brain Res. 69:203–215.PubMedGoogle Scholar
  23. 23.
    Schlaepfer, W. W. 1974. Effects of energy deprivation on Wallerian degeneration in isolated segments of rat peripheral nerve. Brain Res. 78:71–81.PubMedGoogle Scholar
  24. 24.
    Schlaepfer, W. W. 1974. Structural alterations of peripheral nerve induced by the calcium ionophore, A23187. Brain Res. 136:1–9.Google Scholar
  25. 25.
    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.PubMedGoogle Scholar
  26. 26.
    Schlaepfer, W. W., andFreeman, L. A. 1978. Neurofilament proteins of rat peripheral nerve and spinal cord. J. Cell Biol. 78:653–662.PubMedGoogle Scholar
  27. 27.
    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.PubMedGoogle Scholar
  28. 28.
    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.PubMedGoogle Scholar
  29. 29.
    Schlaepfer, W. W., andHasler, M. B. 1979. Characterization of the calcium-induced disruption of neurofilaments in rat peripheral nerve. Brain. Res. 168:299–309.PubMedGoogle Scholar
  30. 30.
    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.PubMedGoogle Scholar
  31. 31.
    Schlaepfer, W. W., andMicko, S. 1978. Chemical and structural changes of neurofilaments in transected rat sciatic nerve. J. Cell Biol. 78:369–378.PubMedGoogle Scholar
  32. 32.
    Schlaepfer, W. W., andMicko, S. 1979. Calcium-dependent alterations of neurofilament proteins of rat peripheral nerve. J. Neurochem. 32:211–219.PubMedGoogle Scholar
  33. 33.
    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.Google Scholar
  34. 34.
    Schook, W. J., andNorton, W. T. 1975. On the composition of axonal neurofilaments. Trans. Am. Soc. Neurochem. 1:214.Google Scholar
  35. 35.
    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.PubMedGoogle Scholar
  36. 36.
    Shelanski, M. L., Albert, S., DeVries, G. H., andNorton, W. T. 1971. Isolation of filaments from brain. Science 174:1242–1245.PubMedGoogle Scholar
  37. 37.
    Uyeda, C. T., Eng, L. F., andBignami, A. 1972. Immunological study of the glial fibrillary acidic protein. Brain Res. 37:81–89.PubMedGoogle Scholar
  38. 38.
    Wuerker, R. B., andKirkpatrick, J. B. 1972. Neuronal microtubules, neurofilaments microfilaments. Int. Rev. Cytol. 33:45–75.PubMedGoogle Scholar
  39. 39.
    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.PubMedGoogle Scholar

Copyright information

© Plenum Publishing Corporation 1981

Authors and Affiliations

  • William W. Schlaepfer
    • 1
  • Un-Jin P. Zimmerman
    • 1
  1. 1.Laboratory of NeuropathologyUniversity of PennsylvaniaPhiladelphia

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