Calcitonin gene-related peptide contributes to peripheral nerve injury-induced mechanical hypersensitivity through CCL5 and p38 pathways

J Neuroimmunol. 2016 Aug 15:297:68-75. doi: 10.1016/j.jneuroim.2016.05.003. Epub 2016 May 6.

Abstract

The role of calcitonin gene related peptide (CGRP) in neuropathic pain was investigated in a mouse model of neuropathic pain, spinal nerve L5 transection (L5Tx). Intrathecal injection (i.t.) of CGRP8-37, a CGRP antagonist, significantly reduced L5Tx-induced mechanical hypersensitivity and lumbar spinal cord CCL5 expression. i.t. injection of a CCL5 neutralizing antibody significantly inhibited L5Tx-induced mechanical hypersensitivity. Further, pre-treatment with a p38-inhibitor, SB203580, was able to reduce CGRP-induced mechanical hypersensitivity, but not CGRP-induced CCL5 production. Our data indicate that CGRP can play its pro-nociceptive role through both a spinal cord CCL5-dependent, p38-independent pathway, and a p38-depenented, CCL5-independent pathway.

Keywords: CCL5; Calcitonin gene-related peptide (CGRP); Neuropathic pain; Spinal cord; Spinal nerve L5 transection; p38.

MeSH terms

  • Animals
  • Antibodies / pharmacology
  • Calcitonin Gene-Related Peptide / metabolism*
  • Calcitonin Gene-Related Peptide / therapeutic use
  • Cells, Cultured
  • Chemokine CCL5 / immunology
  • Chemokine CCL5 / metabolism*
  • Cytokines / metabolism
  • Disease Models, Animal
  • Enzyme Inhibitors / pharmacology
  • Female
  • Hyperalgesia / drug therapy
  • Hyperalgesia / etiology*
  • Hyperalgesia / metabolism*
  • Imidazoles / pharmacology
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Neuroglia / drug effects
  • Neuroglia / metabolism
  • Pain Threshold / drug effects
  • Peptide Fragments / therapeutic use
  • Peripheral Nerve Injuries / complications*
  • Pyridines / pharmacology
  • Spinal Cord / cytology
  • Spinal Cord / metabolism
  • Spinal Nerves / pathology

Substances

  • Antibodies
  • Chemokine CCL5
  • Cytokines
  • Enzyme Inhibitors
  • Imidazoles
  • Peptide Fragments
  • Pyridines
  • calcitonin gene-related peptide (8-37)
  • Calcitonin Gene-Related Peptide
  • SB 203580