Abstract
Secondary injury exacerbates the extent of spinal cord insults, yet the mechanistic basis of this phenomenon has largely been unexplored. Here we report that broad regions of the peritraumatic zone are characterized by a sustained process of pathologic, high ATP release. Spinal cord neurons expressed P2X7 purine receptors (P2X7R), and exposure to ATP led to high-frequency spiking, irreversible increases in cytosolic calcium and cell death. To assess the potential effect of P2X7R blockade in ameliorating acute spinal cord injury (SCI), we delivered P2X7R antagonists OxATP or PPADS to rats after acute impact injury. We found that both OxATP and PPADS significantly improved functional recovery and diminished cell death in the peritraumatic zone. These observations demonstrate that SCI is associated with prolonged purinergic receptor activation, which results in excitotoxicity-based neuronal degeneration. P2X7R antagonists inhibit this process, reducing both the histological extent and functional sequelae of acute SCI.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$209.00 per year
only $17.42 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
North, R.A. Molecular physiology of P2X receptors. Physiol. Rev. 82, 1013–1067 (2002).
Khakh, B.S., Bao, X.R., Labarca, C. & Lester, H.A. Neuronal P2X transmitter-gated cation channels change their ion selectivity in seconds. Nat. Neurosci. 2, 322–330 (1999).
Di Virgilio, F. et al. Cytolytic P2X purinoceptors. Cell Death Differ. 5, 191–199 (1998).
Deuchars, S.A. et al. Neuronal P2X7 receptors are targeted to presynaptic terminals in the central and peripheral nervous systems. J. Neurosci. 21, 7143–7152 (2001).
Cotrina, M.L. et al. Connexins regulate calcium signaling by controlling ATP release. Proc. Natl. Acad. Sci. USA 95, 15735–15740 (1998).
Guthrie, P.B. et al. ATP released from astrocytes mediates glial calcium waves. J. Neurosci. 19, 520–528 (1999).
Arcuino, G. et al. Intercellular calcium signaling mediated by point-source burst release of ATP. Proc. Natl. Acad. Sci. USA 99, 9840–9845 (2002).
Fields, R.D. & Stevens-Graham, B. New insights into neuron-glia communication. Science 298, 556–562 (2002).
Haydon, P.G. Glia: listening and talking to the synapse. Nat. Rev. Neurosci. 2, 185–193 (2001).
Nedergaard, M., Ransom, B. & Goldman, S. New roles for astrocytes: Redefining the functional architecture of the brain. Trends Neurosci. 26, 523–530 (2003).
Scemes, E., Suadicani, S.O. & Spray, D.C. Intercellular communication in spinal cord astrocytes: fine tuning between gap junctions and P2 nucleotide receptors in calcium wave propagation. J. Neurosci. 20, 1435–1445 (2000).
Fam, S.R., Gallagher, C.J. & Salter, M.W. P2Y(1) purinoceptor-mediated Ca2+ signaling and Ca2+ wave propagation in dorsal spinal cord astrocytes. J. Neurosci. 20, 2800–2808 (2000).
Cook, S.P. & McCleskey, E.W. Cell damage excites nociceptors through release of cytosolic ATP. Pain 95, 41–47 (2002).
Neary, J.T., Kang, Y., Willoughby, K.A. & Ellis, E.F. Activation of extracellular signal-regulated kinase by stretch-induced injury in astrocytes involves extracellular ATP and P2 purinergic receptors. J. Neurosci. 23, 2348–2356 (2003).
Du, S. et al. Calcium influx and activation of calpain I mediate acute reactive gliosis in injured spinal cord. Exp. Neurol. 157, 96–105 (1999).
Stokes, B.T., Fox, P. & Hollinden, G. Extracellular calcium activity in the injured spinal cord. Exp. Neurol. 80, 561–572 (1983).
Nilsson, P., Hillered, L., Olsson, Y., Sheardown, M.J. & Hansen, A.J. Regional changes in interstitial K+ and Ca2+ levels following cortical compression contusion trauma in rats. J. Cereb. Blood Flow Metab. 13, 183–192 (1993).
Stout, C. & Charles, A. Modulation of intercellular calcium signaling in astrocytes by extracellular calcium and magnesium. Glia 43, 265–273 (2003).
Bianchi, B.R. et al. Pharmacological characterization of recombinant human and rat P2X receptor subtypes. Eur. J. Pharmacol. 376, 127–138 (1999).
Wang, Z., Tymianski, M., Jones, O.T. & Nedergaard, M. Impact of cytoplasmic calcium buffering on the spatial and temporal characteristics of intercellular calcium signals in astrocytes. J. Neurosci. 17, 7359–7371 (1997).
Takano, T. et al. Glutamate release promotes growth of malignant gliomas. Nat. Med. 7, 1010–1015 (2001).
Chow, S.C., Kass, G.E. & Orrenius, S. Purines and their roles in apoptosis. Neuropharmacology 36, 1149–1156 (1997).
Le Feuvre, R.A., Brough, D., Touzani, O. & Rothwell, N.J. Role of P2X7 receptors in ischemic and excitotoxic brain injury in vivo. J. Cereb. Blood Flow Metab. 23, 381–384 (2003).
Emery, E. et al. Apoptosis after traumatic human spinal cord injury. J. Neurosurg. 89, 911–920 (1998).
Keane, R.W. et al. Apoptotic and anti-apoptotic mechanisms following spinal cord injury. J. Neuropathol. Exp. Neurol. 60, 422–429 (2001).
Murgia, M., Hanau, S., Pizzo, P., Rippa, M. & Di Virgilio, F. Oxidized ATP. An irreversible inhibitor of the macrophage purinergic P2Z receptor. J. Biol. Chem. 268, 8199–8203 (1993).
Michel, A.D., Kaur, R., Chessell, I.P. & Humphrey, P.P. Antagonist effects on human P2X(7) receptor-mediated cellular accumulation of YO-PRO-1. Br. J. Pharmacol. 130, 513–520 (2000).
Egan, T.M. & Khakh, B.S. Contribution of calcium ions to P2X channel responses. J. Neurosci. 24, 3413–3420 (2004).
Collo, G. et al. Tissue distribution of the P2X7 receptor. Neuropharmacology 36, 1277–1283 (1997).
Armstrong, J.N., Brust, T.B., Lewis, R.G. & MacVicar, B.A. Activation of presynaptic P2X7-like receptors depresses mossy fiber-CA3 synaptic transmission through p38 mitogen-activated protein kinase. J. Neurosci. 22, 5938–5945 (2002).
Duan, S., Anderson, C.M., Keung, E.C., Chen, Y. & Swanson, R.A. P2X7 receptor-mediated release of excitatory amino acids from astrocytes. J. Neurosci. 23, 1320–1328 (2003).
Grafe, P., Mayer, C., Takigawa, T., Kamleiter, M. & Sanchez-Brandelik, R. Confocal calcium imaging reveals an ionotropic P2 nucleotide receptor in the paranodal membrane of rat Schwann cells. J. Physiol. 515 (Pt. 2), 377–383 (1999).
Ray, S.K., Dixon, C.E. & Banik, N.L. Molecular mechanisms in the pathogenesis of traumatic brain injury. Histol. Histopathol. 17, 1137–1152 (2002).
Newman, E.A. New roles for astrocytes: regulation of synaptic transmission. Trends Neurosci. 26, 536–542 (2003).
Cawthon, D.F., Senter, H.J. & Stewart, W.B. Comparison of hydrogen clearance and 14C-antipyrine autoradiography in the measurement of spinal cord blood flow after severe impact injury. J. Neurosurg. 52, 801–807 (1980).
Farooque, M., Hillered, L., Holtz, A. & Olsson, Y. Changes of extracellular levels of amino acids after graded compression trauma to the spinal cord: an experimental study in the rat using microdialysis. J. Neurotrauma 13, 537–548 (1996).
Jeremic, A., Jeftinija, K., Stevanovic, J., Glavaski, A. & Jeftinija, S. ATP stimulates calcium-dependent glutamate release from cultured astrocytes. J. Neurochem. 77, 664–675 (2001).
Nedergaard, M., Takano, T. & Hansen, A.J. Beyond the role of glutamate as a neurotransmitter. Nat. Rev. Neurosci. 3, 748–755 (2002).
Agrawal, S.K. & Fehlings, M.G. Role of NMDA and non-NMDA ionotropic glutamate receptors in traumatic spinal cord axonal injury. J. Neurosci. 17, 1055–1063 (1997).
Haghighi, S.S., Johnson, G.C., de Vergel, C.F. & Vergel Rivas, B.J. Pretreatment with NMDA receptor antagonist MK801 improves neurophysiological outcome after an acute spinal cord injury. Neurol. Res. 18, 509–515 (1996).
Le Feuvre, R., Brough, D. & Rothwell, N. Extracellular ATP and P2X7 receptors in neurodegeneration. Eur. J. Pharmacol. 447, 261–269 (2002).
Solle, M. et al. Altered cytokine production in mice lacking P2X(7) receptors. J. Biol. Chem. 276, 125–132 (2001).
Labasi, J.M. et al. Absence of the P2X7 receptor alters leukocyte function and attenuates an inflammatory response. J. Immunol. 168, 6436–6445 (2002).
Suzuki, T. et al. Production and release of neuroprotective tumor necrosis factor by P2X7 receptor-activated microglia. J. Neurosci. 24, 1–7 (2004).
Parvathenani, L.K. et al. P2X7 mediates superoxide production in primary microglia and is up-regulated in a transgenic mouse model of Alzheimer's disease. J. Biol. Chem. 278, 13309–13317 (2003).
Goldman, S.A. & Nedergaard, M. Erythropoietin strikes a new cord. Nat. Med. 8, 785–787 (2002).
Profyris, C. et al. Degenerative and regenerative mechanisms governing spinal cord injury. Neurobiol. Dis. 15, 415–436 (2004).
Basso, D.M., Beattie, M.S. & Bresnahan, J.C. A sensitive and reliable locomotor rating scale for open field testing in rats. J. Neurotrauma 12, 1–21 (1995).
Nedergaard, M. & Hansen, A.J. Characterization of cortical depolarization evoked in focal cerebral ischemia. J. Cereb. Blood Flow Metab. 13, 568–574 (1993).
Lin, J.H. et al. Gap-junction-mediated propagation and amplification of cell injury. Nat. Neurosci. 1, 494–500 (1998).
Lin, J.H. et al. Connexin mediates gap junction-independent resistance to cellular injury. J. Neurosci. 23, 430–441 (2003).
Roy, N.S. et al. Telomerase immortalization of neuronally restricted progenitor cells derived from the human fetal spinal cord. Nat. Biotechnol. 22, 297–305 (2004).
Acknowledgements
This study was supported by the National Institute of Neurological Disorders and Stroke and the New York State Spinal Cord Injury Research Program.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Rights and permissions
About this article
Cite this article
Wang, X., Arcuino, G., Takano, T. et al. P2X7 receptor inhibition improves recovery after spinal cord injury. Nat Med 10, 821–827 (2004). https://doi.org/10.1038/nm1082
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nm1082
This article is cited by
-
The activation of dormant ependymal cells following spinal cord injury
Stem Cell Research & Therapy (2023)
-
Synchronized activity of sensory neurons initiates cortical synchrony in a model of neuropathic pain
Nature Communications (2023)
-
MicroRNA: Crucial modulator in purinergic signalling involved diseases
Purinergic Signalling (2023)
-
The alarmin interleukin-1α triggers secondary degeneration through reactive astrocytes and endothelium after spinal cord injury
Nature Communications (2022)
-
P2R Inhibitors Prevent Antibody-Mediated Complement Activation in an Animal Model of Neuromyelitis Optica
Neurotherapeutics (2022)