Spinal cord injury induces early and persistent lesional P2X4 receptor expression

J Neuroimmunol. 2005 Jun;163(1-2):185-9. doi: 10.1016/j.jneuroim.2005.02.016. Epub 2005 Apr 26.

Abstract

Following spinal cord injury (SCI), neuropathic, chronic pain is a major cause of disability. Recently, glial P2X4 receptor (P2X4R) has been identified as a major contributor to the development of neuropathic pain after peripheral nerve injury. Here we report analysis of P2X4R expression following rat SCI. Significant lesional accumulation of P2X4R+ cells was detected as early as 24 h after SCI, reaching maximum cell numbers on Day 7. Thereafter cell numbers declined but persisted at significantly elevated, sub-maximal levels (>70%) until 1 month post injury. Double-immunolabeling identified the majority of lesional P2X4R+ cells as activated microglia/macrophages and surviving neurons/neurites. Increase of P2X4R+, beta-APP+ hypertrophic neurites correlated with proximity to the lesion. Further, P2X4R+ cells coexpressed the intracellular regulators of signalling cascades, COX-1 (>20%), COX-2 (>5%), RhoA (>60%) and RhoB (>10%).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Immunohistochemistry
  • Molecular Sequence Data
  • Rats
  • Rats, Inbred Lew
  • Receptors, Purinergic P2 / biosynthesis*
  • Receptors, Purinergic P2 / physiology
  • Receptors, Purinergic P2X4
  • Spinal Cord Injuries / metabolism*
  • Spinal Cord Injuries / pathology
  • Time Factors

Substances

  • P2rx4 protein, rat
  • Receptors, Purinergic P2
  • Receptors, Purinergic P2X4