(S)-lacosamide inhibition of CRMP2 phosphorylation reduces postoperative and neuropathic pain behaviors through distinct classes of sensory neurons identified by constellation pharmacology

Pain. 2016 Jul;157(7):1448-1463. doi: 10.1097/j.pain.0000000000000555.

Abstract

Chronic pain affects the life of millions of people. Current treatments have deleterious side effects. We have advanced a strategy for targeting protein interactions which regulate the N-type voltage-gated calcium (CaV2.2) channel as an alternative to direct channel block. Peptides uncoupling CaV2.2 interactions with the axonal collapsin response mediator protein 2 (CRMP2) were antinociceptive without effects on memory, depression, and reward/addiction. A search for small molecules that could recapitulate uncoupling of the CaV2.2-CRMP2 interaction identified (S)-lacosamide [(S)-LCM], the inactive enantiomer of the Food and Drug Administration-approved antiepileptic drug (R)-lacosamide [(R)-LCM, Vimpat]. We show that (S)-LCM, but not (R)-LCM, inhibits CRMP2 phosphorylation by cyclin dependent kinase 5, a step necessary for driving CaV2.2 activity, in sensory neurons. (S)-lacosamide inhibited depolarization-induced Ca influx with a low micromolar IC50. Voltage-clamp electrophysiology experiments demonstrated a commensurate reduction in Ca currents in sensory neurons after an acute application of (S)-LCM. Using constellation pharmacology, a recently described high content phenotypic screening platform for functional fingerprinting of neurons that uses subtype-selective pharmacological agents to elucidate cell-specific combinations (constellations) of key signaling proteins that define specific cell types, we investigated if (S)-LCM preferentially acts on certain types of neurons. (S)-lacosamide decreased the dorsal root ganglion neurons responding to mustard oil, and increased the number of cells responding to menthol. Finally, (S)-LCM reversed thermal hypersensitivity and mechanical allodynia in a model of postoperative pain, and 2 models of neuropathic pain. Thus, using (S)-LCM to inhibit CRMP2 phosphorylation is a novel and efficient strategy to treat pain, which works by targeting specific sensory neuron populations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Acetamides / pharmacology*
  • Acetamides / therapeutic use
  • Animals
  • Behavior, Animal / drug effects
  • Intercellular Signaling Peptides and Proteins
  • Lacosamide
  • Nerve Tissue Proteins / metabolism*
  • Neuralgia / drug therapy*
  • Neuralgia / etiology
  • Neuralgia / metabolism
  • Pain, Postoperative / drug therapy*
  • Pain, Postoperative / etiology
  • Pain, Postoperative / metabolism
  • Peripheral Nerve Injuries / complications
  • Peripheral Nerve Injuries / metabolism
  • Phosphorylation / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Sensory Receptor Cells / drug effects*
  • Sensory Receptor Cells / metabolism

Substances

  • Acetamides
  • Intercellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins
  • collapsin response mediator protein-2
  • Lacosamide