Cathepsin E in neutrophils contributes to the generation of neuropathic pain in experimental autoimmune encephalomyelitis

Pain. 2019 Sep;160(9):2050-2062. doi: 10.1097/j.pain.0000000000001596.

Abstract

Pain is a frequent and disabling symptom in patients with multiple sclerosis (MS); however, the underlying mechanisms of MS-related pain are not fully understood. Here, we demonstrated that cathepsin E (CatE) in neutrophils contributes to the generation of mechanical allodynia in experimental autoimmune encephalomyelitis, an animal model of MS. We showed that CatE-deficient (CatE) mice were highly resistant to myelin oligodendrocyte glycoprotein (MOG35-55)-induced mechanical allodynia. After MOG35-55 immunization, neutrophils immediately accumulated in the dorsal root ganglion (DRG). Adoptive transfer of MOG35-55-stimulated wild-type neutrophils into the dorsal root ganglion induced mechanical allodynia in the recipient C57BL/6 mice. However, the pain threshold did not change when MOG35-55-stimulated CatE neutrophils were transferred into the recipient C57BL/6 mice. MOG35-55 stimulation caused CatE-dependent secretion of elastase in neutrophils. Behavioral analyses revealed that sivelestat, a selective neutrophil elastase inhibitor, suppressed mechanical allodynia induced by adoptively transferred MOG35-55-stimulated neutrophils. MOG35-55 directly bound to toll-like receptor 4, which led to increased production of CatE in neutrophils. Our findings suggest that inhibition of CatE-dependent elastase production in neutrophil might be a potential therapeutic target for pain in patients with MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cathepsin E / deficiency*
  • Cathepsin E / genetics
  • Encephalomyelitis, Autoimmune, Experimental / chemically induced
  • Encephalomyelitis, Autoimmune, Experimental / genetics
  • Encephalomyelitis, Autoimmune, Experimental / metabolism*
  • Female
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Myelin-Oligodendrocyte Glycoprotein / metabolism*
  • Myelin-Oligodendrocyte Glycoprotein / toxicity
  • Neuralgia / chemically induced
  • Neuralgia / genetics
  • Neuralgia / metabolism*
  • Neutrophils / metabolism*
  • Peptide Fragments / metabolism
  • Peptide Fragments / toxicity

Substances

  • Myelin-Oligodendrocyte Glycoprotein
  • Peptide Fragments
  • myelin oligodendrocyte glycoprotein (35-55)
  • Cathepsin E
  • Ctse protein, mouse