The inhibitory effect of Phα1β toxin on diabetic neuropathic pain involves the CXCR4 chemokine receptor

Pharmacol Rep. 2020 Feb;72(1):47-54. doi: 10.1007/s43440-019-00002-3. Epub 2020 Jan 8.

Abstract

Background: Diabetic neuropathy is a common cause of painful diabetic neuropathy (PDN). C-X-C chemokine receptor type 4 (CXCR4) expression is increased in peripheral nerve samples from diabetes patients, suggesting a role for CXCR4 in PDN. Therefore, we evaluated the effects of Phα1β, ω-conotoxin MVIIA, and AMD3100 in a model of streptozotocin (STZ)-induced PDN in rodents and naïve model of rats with the activation of the CXCR4/stromal cell-derived factor 1 (SDF-1) signal.

Methods: Diabetic neuropathy was induced by intraperitoneal (ip) injection of STZ in Wistar rats. Naïve rats were intrathecally injected with SDF-1 to test the CXCR4/SDF-1 signal. The effects of Phα1β intrathecal (it), ω-conotoxin MVIIA intrathecal (it), and AMD3100 intraperitoneal (ip) on rat hypersensitivity, IL-6, and the intracellular calcium [Ca2+]i content of diabetic synaptosomes were studied.

Results: The drugs reduced the hypersensitivity in diabetic rats. SDF-1 (1.0 µg/it) administration in naïve rats induced hypersensitivity. Phα1β (100 pmol/it) or AMD3100 (2.5 µg/ip) reduced this hypersensitivity after 2 h treatments, while ω-conotoxin MVIIA did not have an effect. IL-6 and [Ca2+]i content increased in the spinal cord synaptosomes in diabetic rats. The drug treatments reduced IL-6 and the calcium influx in diabetic synaptosomes.

Conclusions: Phα1β, ω-conotoxin MVIIA, and AMD3100, after 2 h of treatment of STZ-induced PDN, reduced hypersensitivity in diabetic rats. In naïve rats with CXCR4/SDF-1 activation, the induced hypersensitivity decreased after 2 h treatments with Phα1β or AMD-3100, while ω-conotoxin MVIIA did not affect. The inhibitory effects of Phα1β on PDN may involve voltage-dependent calcium channels.

Keywords: AMD3100; CXCR4 chemokine receptor; Diabetic neuropathy; Phα1β; ω-Conotoxin MVIIA.

Publication types

  • Comparative Study

MeSH terms

  • Analgesics / pharmacology*
  • Animals
  • Benzylamines
  • Calcium / metabolism
  • Calcium Channels / metabolism
  • Chemokine CXCL12 / metabolism
  • Cyclams
  • Diabetes Mellitus, Experimental / complications
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetic Neuropathies / drug therapy*
  • Heterocyclic Compounds / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, CXCR4 / metabolism
  • Spider Venoms / pharmacology*
  • omega-Conotoxins / pharmacology

Substances

  • Analgesics
  • Benzylamines
  • CXCL12 protein, rat
  • Calcium Channels
  • Chemokine CXCL12
  • Cxcr4 protein, rat
  • Cyclams
  • Heterocyclic Compounds
  • Phalpha1beta toxin, Phoneutria nigriventer
  • Receptors, CXCR4
  • Spider Venoms
  • omega-Conotoxins
  • ziconotide
  • plerixafor
  • Calcium