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Olfactory ensheathing cells — another miracle cure for spinal cord injury?

Abstract

Several recent publications describe remarkably promising effects of transplanting olfactory ensheathing cells as a potential future method to repair human spinal cord injuries. But why were cells from the nose transplanted into the spinal cord? What are olfactory ensheathing cells, and how might they produce these beneficial effects? And more generally, what do we mean by spinal cord injury? To what extent can we compare repair in an animal to repair in a human?

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Figure 1: The specialized glial cells are one of the proposed candidates for an in vivo equivalent of olfactory ensheathing cells19,33,79.
Figure 2: A schematic representation of the glial capsule enclosing an olfactory glomerulus.
Figure 3: Cellular changes associated with the advance of the regenerating cut corticospinal tract axons (black) across lesions (grey) repaired with transplants of olfactory ensheathing cells.

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References

  1. Suzuki, M. & Raisman, G. The glial framework of central white matter tracts: segmented rows of contiguous interfascicular oligodendrocytes and solitary astrocytes give rise to a continuous meshwork of transverse and longitudinal processes in the adult rat fimbria. Glia 6, 222–235 (1992).

    Article  CAS  Google Scholar 

  2. Chisholm, A. & Tessier-Lavigne, M. Conservation and divergence of axon guidance mechanisms. Curr. Opin. Neurobiol. 9, 603–615 (1999).

    Article  CAS  Google Scholar 

  3. Li, Y., Field, P. M. & Raisman, G. Death of oligodendrocytes and microglial phagocytosis of myelin precede immigration of Schwann cells into the spinal cord. J. Neurocytol. 28, 417–427 (1999).

    Article  CAS  Google Scholar 

  4. Crowe, M. J., Bresnahan, J. C., Shuman, S. L., Masters, J. N. & Beattie, M. S. Apoptosis and delayed degeneration after spinal cord injury in rats and monkeys. Nature Med. 3, 73–76 (1997).

    Article  CAS  Google Scholar 

  5. Davies, S. J. A. et al. Regeneration of adult axons in white matter tracts of the central nervous system. Nature 390, 680–683 (1997).

    Article  CAS  Google Scholar 

  6. Fitch, M. T. & Silver, J. Activated macrophages and the blood–brain barrier: inflammation after CNS injury leads to increases in putative inhibitory molecules. Exp. Neurol. 148, 587–603 (1997).

    Article  CAS  Google Scholar 

  7. Fawcett, J. W. Astrocytic and neuronal factors affecting axon regeneration in the damaged central nervous system. Cell Tissue Res. 290, 371–377 (1997).

    Article  CAS  Google Scholar 

  8. Ramón y Cajal, S. Degeneration and Regeneration of the Nervous System (Hafner, New York, 1928).

    Google Scholar 

  9. Richardson, P. M., Issa, V. M. K. & Aguayo, A. J. Regeneration of long spinal axons in the rat. J. Neurocytol. 13, 165–182 (1984).

    Article  CAS  Google Scholar 

  10. Trigueros, M. A., Sauvé, Y., Lund, R. D. & Vidal-Sanz, M. Selective innervation of retinorecipient brainstem nuclei by retinal ganglion cell axons regenerating through peripheral nerve grafts in adult rats. J. Neurosci. 20, 361–374 (2000).

    Article  Google Scholar 

  11. Li, Y. & Raisman, G. Schwann cells induce sprouting in motor and sensory axons in the adult rat spinal cord. J. Neurosci. 14, 4050–4063 (1994).

    Article  CAS  Google Scholar 

  12. Xu, X. M., Chen, A., Guénard, V., Kleitman, N. & Bunge, M. B. Bridging Schwann cell transplants promote axonal regeneration from both the rostral and caudal stumps of transected adult rat spinal cord. J. Neurocytol. 26, 1–16 (1997).

    Article  CAS  Google Scholar 

  13. Paíno, C. L., Fernandez-Valle, C., Bates, M. L. & Bunge, M. B. Regrowth of axons in lesioned adult rat spinal cord: promotion by implants of cultured Schwann cells. J. Neurocytol. 23, 433–452 (1994).

    Article  Google Scholar 

  14. Graziadei, P. P. C. & Montigraziadei, G. A. Neurogenesis and neuron regeneration in the olfactory system of mammals. I. Morphological aspects of differentiation and structural organization of the olfactory sensory neurons. J. Neurocytol. 8, 1–18 (1979).

    Article  CAS  Google Scholar 

  15. Farbman, A. I. Olfactory neurogenesis: genetic or environmental controls? Trends Neurosci. 13, 362–365 (1990).

    Article  CAS  Google Scholar 

  16. Graziadei, P. P. C., Levine, R. R. & Montigraziadei, G. A. Plasticity of connections of the olfactory sensory neuron: regeneration into the forebrain following bulbectomy in the neonatal mouse. Neuroscience 4, 713–727 (1979).

    Article  CAS  Google Scholar 

  17. Ramón-Cueto, A. & Valverde, F. Olfactory bulb ensheathing glia: A unique cell type with axonal growth-promoting properties. Glia 14, 163–173 (1995).

    Article  Google Scholar 

  18. Doucette, J. R. The glial cells in the nerve fiber layer of the rat olfactory bulb. Anat. Rec. 210, 385–391 (1984).

    Article  CAS  Google Scholar 

  19. Raisman, G. Specialized neuroglial arrangement may explain the capacity of vomeronasal axons to reinnervate central neurons. Neuroscience 14, 237–254 (1985).

    Article  CAS  Google Scholar 

  20. Devon, R. & Doucette, R. Olfactory ensheathing cells myelinate dorsal root ganglion neurites. Brain Res. 589, 175–179 (1992).

    Article  CAS  Google Scholar 

  21. Barnett, S. C., Hutchins, A.-M. & Noble, M. Purification of olfactory nerve ensheathing cells from the olfactory bulb. Dev. Biol. 155, 337–350 (1993).

    Article  CAS  Google Scholar 

  22. Ramón-Cueto, A. & Nieto-Sampedro, M. Glial cells from adult rat olfactory bulb: immunocytochemical properties of pure cultures of ensheathing cells. Neuroscience 47, 213–220 (1992).

    Article  Google Scholar 

  23. Ramón-Cueto, A. & Nieto-Sampedro, M. Regeneration into the spinal cord of transected dorsal root axons is promoted by ensheathing glia transplants. Exp. Neurol. 127, 232–244 (1994).

    Article  Google Scholar 

  24. Ramón-Cueto, A., Plant, G. W., Avila, J. & Bunge, M. B. Long-distance axonal regeneration in the transected adult rat spinal cord is promoted by olfactory ensheathing glia transplants. J. Neurosci. 18, 3803–3815 (1998).

    Article  Google Scholar 

  25. Li, Y., Field, P. M. & Raisman, G. Regeneration of adult rat corticospinal axons induced by transplanted olfactory ensheathing cells. J. Neurosci. 18, 10514–10524 (1998).

    Article  CAS  Google Scholar 

  26. Li, Y., Field, P. M. & Raisman, G. Repair of adult rat corticospinal tract by transplants of olfactory ensheathing cells. Science 277, 2000–2002. (1997).

    Article  CAS  Google Scholar 

  27. Imaizumi, T., Langford, K. L., Waxman, S. G., Greer, C. A. & Kocsis, J. D. Transplanted olfactory ensheathing cells remyelinate and enhance axonal conduction in the demyelinated dorsal columns of the rat spinal cord. J. Neurosci. 18, 6176–6185 (1998).

    Article  CAS  Google Scholar 

  28. Franklin, R. J.M., Gilson, J. M., Franceschini, I. A. & Barnett, S. C. Schwann cell-like myelination following transplantation of an olfactory bulb-ensheathing cell line into areas of demyelination in the adult CNS. Glia 17, 217–224 (1996).

    Article  CAS  Google Scholar 

  29. Ramón-Cueto, A., Cordero, M. I., Santos-Benito, F. F. & Avila, J. Functional recovery of paraplegic rats and motor axon regeneration in their spinal cords by olfactory ensheathing glia. Neuron 25, 425–435 (2000).

    Article  Google Scholar 

  30. Franklin, R. J.M. & Barnett, S. C. Olfactory ensheathing cells and CNS regeneration: The sweet smell of success? Neuron 28, 15–18 (2000).

    Article  CAS  Google Scholar 

  31. Franceschini, I. A. & Barnett, S. C. Low-affinity NGF-receptor and E-N-CAM expression define two types of olfactory nerve ensheathing cells that share a common lineage. Dev. Biol. 173, 327–343 (1996).

    Article  CAS  Google Scholar 

  32. Pixley, S. K. The olfactory nerve contains two populations of glia, identified both in vivo and in vitro. Glia 5, 269–284 (1992).

    Article  CAS  Google Scholar 

  33. Ramón-Cueto, A. & Avila, J. Olfactory ensheathing glia: properties and function. Brain Res. Bull. 46, 175–187 (1998).

    Article  Google Scholar 

  34. Barnett, S. C. et al. Identification of a human olfactory ensheathing cell that can effect transplant-mediated remyelination of demyelinated CNS axons. Brain 123, 1581–1588 (2000).

    Article  Google Scholar 

  35. Weiss, S. et al. Is there a neural stem cell in the mammalian forebrain? Trends Neurosci. 19, 387–393 (1996).

    Article  CAS  Google Scholar 

  36. Pagano, S. F. et al. Isolation and characterization of neural stem cells from the adult human olfactory bulb. Stem Cells 18, 295–300 (2000).

    Article  CAS  Google Scholar 

  37. Olby, N. J. & Blakemore, W. F. Primary demyelination and regeneration of ascending axons in the dorsal funiculus of the rat spinal cord following photochemically induced injury. J. Neurocytol. 25, 465–480 (1996).

    Article  CAS  Google Scholar 

  38. Verdú, E., Rodríguez, F. J., Gudiño-Cabrera, G., Nieto-Sampedro, M. & Navarro, X. Expansion of adult Schwann cells from mouse predegenerated peripheral nerves. J. Neurosci. Methods 99, 111–117 (2000).

    Article  Google Scholar 

  39. Morrissey, T. K., Kleitman, N. & Bunge, R. P. Isolation and functional characterization of Schwann cells derived from adult peripheral nerve. J. Neurosci. 11, 2433–2442 (1991).

    Article  CAS  Google Scholar 

  40. Casella, C. T. B., Bunge, R. P. & Wood, P. M. Improved method for harvesting human Schwann cells from mature peripheral nerve and expansion in vitro. Glia 17, 327–338 (1996).

    Article  CAS  Google Scholar 

  41. Franklin, R. J. & Barnett, S. C. Do olfactory glia have advantages over Schwann cells for CNS repair? J. Neurosci. Res. 50, 665–672 (1997).

    Article  CAS  Google Scholar 

  42. De Carlos, J. A., López-Mascaraque, L. & Valverde, F. Early olfactory fiber projections and cell migration into the rat telencephalon. Int. J. Dev. Neurosci. 14, 853–866 (1996).

    Article  CAS  Google Scholar 

  43. Goldstein, B. J., Fang, H. S., Youngentob, S. L. & Schwob, J. E. Transplantation of multipotent progenitors from the adult olfactory epithelium. Neuroreport 9, 1611–1617 (1998).

    Article  CAS  Google Scholar 

  44. Chuah, M. I., Tennent, R. & Jacobs, I. Response of olfactory Schwann cells to intranasal zinc sulfate irrigation. J. Neurosci. Res. 42, 470–478 (1995).

    Article  CAS  Google Scholar 

  45. Liu, K. L., Chuah, M. I. & Lee, K. K. H. Soluble factors from the olfactory bulb attract olfactory Schwann cells. J. Neurosci. 15, 990–1000 (1995).

    Article  CAS  Google Scholar 

  46. Kato, T., Honmou, O., Uede, T., Hashi, K. & Kocsis, J. D. Transplantation of human olfactory ensheathing cells elicits remyelination of demyelinated rat spinal cord. Glia 30, 209–218 (2000).

    Article  CAS  Google Scholar 

  47. Merline, M. & Kalil, K. Cell death of corticospinal neurons is induced by axotomy before but not after innervation of spinal targets. J. Comp. Neurol. 296, 506–516 (1990).

    Article  CAS  Google Scholar 

  48. Tseng, G. F. & Prince, D. A. Structural and functional alterations in rat corticospinal neurons after axotomy. J. Neurophysiol. 75, 248–267 (1996).

    Article  CAS  Google Scholar 

  49. Fishman, P. S. & Kelly, J. P. The fate of severed corticospinal axons. Neurology 34, 1161–1167 (1984).

    Article  CAS  Google Scholar 

  50. Li, Y. & Raisman, G. Sprouts from cut corticospinal axons persist in the presence of astrocytic scarring in long-term lesions of the adult rat spinal cord. Exp. Neurol. 134, 102–111 (1995).

    Article  CAS  Google Scholar 

  51. Kuang, R. Z. & Kalil, K. Specificity of corticospinal axon arbors sprouting into denervated contralateral spinal cord. J. Comp. Neurol. 302, 461–472 (1990).

    Article  CAS  Google Scholar 

  52. Weidner, N., Ner, A., Salimi, N. & Tuszynski, M. H. Spontaneous corticospinal axonal plasticity and functional recovery after adult central nervous system injury. Proc. Natl Acad. Sci. USA 98, 3513–3518 (2001).

    Article  CAS  Google Scholar 

  53. Li, W. W. Y., Yew, D. T. W., Chuah, M. I., Leung, P. C. & Tsang, D. S. C. Axonal sprouting in the hemisected adult rat spinal cord. Neuroscience 61, 133–139 (1994).

    Article  CAS  Google Scholar 

  54. Aoki, M., Fujito, Y., Satomi, H., Kurosawa, Y. & Kasaba, T. The possible role of collateral sprouting in the functional restoration of corticospinal connections after spinal hemisection. Neurosci. Res. 3, 617–627 (1986).

    Article  CAS  Google Scholar 

  55. Kapfhammer, J. P. Axon sprouting in the spinal cord: growth promoting and growth inhibitory mechanisms. Anat. Embryol. (Berl.) 196, 417–426 (1997).

    Article  CAS  Google Scholar 

  56. Eidelberg, E. Consequences of spinal cord lesions upon motor function, with special reference to locomotor activity. Prog. Neurobiol. 17, 185–202 (1981).

    Article  CAS  Google Scholar 

  57. Lawrence, D. G. & Kuypers, H. G. J. M. The functional organization of the motor system. I. The effects of bilateral pyramidal lesions. Brain 91, 1–14 (1968).

    Article  CAS  Google Scholar 

  58. Heffner, R. S. & Masterton, R. B. The role of the corticospinal tract in the evolution of human digital dexterity. Brain Behav. Evol. 23, 165–183 (1983).

    Article  CAS  Google Scholar 

  59. Bregman, B. S. et al. Recovery from spinal cord injury mediated by antibodies to neurite growth inhibitors. Neuron 15, 498–501 (1995).

    Google Scholar 

  60. Kuypers, H. G. J. M. Progress in Brain Research Vol. 11 (eds Eccles, J. C. & Schadé, J. P.) 178–202 (Elsevier, Amsterdam, 1964).

    Google Scholar 

  61. Galea, M. P. & Darian-Smith, I. Multiple corticospinal neuron populations in the macaque monkey are specified by their unique cortical origins, spinal terminations, and connections. Cereb. Cortex 4, 166–194 (1994).

    Article  CAS  Google Scholar 

  62. Rossignol, S. & Dubuc, R. Spinal pattern generation. Curr. Opin. Neurobiol. 4, 894–902 (1994).

    Article  CAS  Google Scholar 

  63. Hultborn, H. et al. How do we approach the locomotor network in the mammalian spinal cord? Ann. NY Acad. Sci. 860, 70–82 (1998).

    Article  CAS  Google Scholar 

  64. Wickelgren, I. Teaching the spinal cord to walk. Science 279, 319–321 (1998).

    Article  CAS  Google Scholar 

  65. Harkema, S. J. et al. Human lumbosacral spinal cord interprets loading during stepping. J. Neurophysiol. 77, 797–811 (1997).

    Article  CAS  Google Scholar 

  66. Rossignol, S. Locomotion and its recovery after spinal injury. Curr. Opin. Neurobiol. 10, 708–716 (2000).

    Article  CAS  Google Scholar 

  67. Edgerton, V. R. et al. Use-dependent plasticity in spinal stepping and standing. Adv. Neurol. 72, 233–247 (1997).

    CAS  PubMed  Google Scholar 

  68. Wernig, A., Müller, S., Nanassy, A. & Cagol, E. Laufband therapy based on 'rules of spinal locomotion' is effective in spinal cord injured persons. Eur. J. Neurosci. 7, 823–829 (1995).

    Article  CAS  Google Scholar 

  69. Castro, A. J. The effects of cortical ablations on digital usage in the rat. Brain Res. 37, 173–185 (1972).

    Article  CAS  Google Scholar 

  70. Castro, A. J. Motor performance in rats. The effects of pyramidal tract section. Brain Res. 44, 313–323 (1972).

    Article  CAS  Google Scholar 

  71. Xu, X. M., Zhang, S. X., Li, H. Y., Aebischer, P. & Bunge, M. B. Regrowth of axons into the distal spinal cord through a Schwann-cell-seeded mini-channel implanted into hemisected adult rat spinal cord. Eur. J. Neurosci. 11, 1723–1740 (1999).

    Article  CAS  Google Scholar 

  72. Joosten, E. A. J., Bär, P. R. & Gispen, W. H. Collagen implants and cortico-spinal axonal growth after mid- thoracic spinal cord lesion in the adult rat. J. Neurosci. Res. 41, 481–490 (1995).

    Article  CAS  Google Scholar 

  73. Bomze, H. M., Bulsara, K. R., Iskandar, B. J., Caroni, P. & Pate Skene, J. H. Spinal axon regeneration evoked by replacing two growth cone proteins in adult neurons. Nature Neurosci. 4, 38–43 (2001).

    Article  CAS  Google Scholar 

  74. McKerracher, L. et al. Identification of myelin-associated glycoprotein as a major myelin-derived inhibitor of neurite growth. Neuron 13, 805–811 (1994).

    Article  CAS  Google Scholar 

  75. Bregman, B. S. Regeneration in the spinal cord. Curr. Opin. Neurobiol. 8, 800–807 (1998).

    Article  CAS  Google Scholar 

  76. Olson, L. Regeneration in the adult central nervous system: experimental repair strategies. Nature Med. 3, 1329–1335 (1997).

    Article  CAS  Google Scholar 

  77. Lehmann, M. et al. Inactivation of Rho signaling pathway promotes CNS axon regeneration. J. Neurosci. 19, 7537–7547 (1999).

    Article  CAS  Google Scholar 

  78. Cai, D., Shen, Y., De Bellard, M., Tang, S. & Filbin, M. T. Prior exposure to neurotrophins blocks inhibition of axonal regeneration by MAG and myelin via a cAMP-dependent mechanism. Neuron 22, 89–101 (1999).

    Article  CAS  Google Scholar 

  79. Valverde, F. & Lopez-Mascaraque, L. Neuroglial arrangements in the olfactory glomeruli of the hedgehog. J. Comp. Neurol. 307, 658–674 (1991).

    Article  CAS  Google Scholar 

  80. Ramón y Cajal, S. R. Histologie du Système Nerveux de l'Homme et des Vertébrés (Maloine, Paris, 1911).

    Google Scholar 

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Supported by the Medical Research Council the British Neurological Research Trust and the International Spinal Research Trust.

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Traumatic central nervous system injury

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Raisman, G. Olfactory ensheathing cells — another miracle cure for spinal cord injury?. Nat Rev Neurosci 2, 369–375 (2001). https://doi.org/10.1038/35072576

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