title: Further insights into the antinociceptive potential of a peptide disrupting the N-type calcium channel-CRMP-2 signaling complex.
abstract: The N-type voltage-gated calcium channel (Cav 2.2) has gained immense prominence in the treatment of chronic pain. While decreased channel function is ultimately anti-nociceptive, directly targeting the channel can lead to multiple adverse side effects. Targeting modulators of channel activity may facilitate improved analgesic properties associated with channel block and a broader therapeutic window. A novel interaction between Cav 2.2 and collapsin response mediator protein 2 (CRMP-2) positively regulates channel function by increasing surface trafficking. We recently identified a CRMP-2 peptide (TAT-CBD3), which effectively blocks this interaction, reduces or completely reverses pain behavior in a number of inflammatory and neuropathic models. Importantly, TAT-CBD3 did not produce many of the typical side effects often observed with Cav 2.2 inhibitors. Notably chronic pain mechanisms offer unique challenges as they often encompass a mix of both neuropathic and inflammatory elements, whereby inflammation likely causes damage to the neuron leading to neuropathic pain, and neuronal injury may produce inflammatory reactions. To this end, we sought to further disseminate the ability of TAT-CBD3 to alter behavioral outcomes in two additional rodent pain models. While we observed that TAT-CBD3 reversed mechanical hypersensitivity associated with a model of chronic inflammatory pain due to lysophosphotidylcholine-induced sciatic nerve focal demyelination (LPC), injury to the tibial nerve (TNI) failed to respond to drug treatment. Moreover, a single amino acid mutation within the CBD3 sequence demonstrated amplified Cav 2.2 binding and dramatically increased efficacy in an animal model of migraine. Taken together, TAT-CBD3 potentially represents a novel class of therapeutics targeting channel regulation as opposed to the channel itself.
authors.affiliation: Paul and Carole Stark Neurosciences Research Institute, Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Wilson
authors.forename: Joel M
authors.initials: JM
authors.lastname: Brittain
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Piekarz
authors.forename: Carrie J
authors.initials: CJ
authors.lastname: Ballard
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Ripsch
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Cummins
authors.forename: Joyce H
authors.initials: JH
authors.lastname: Hurley
authors.forename: May
authors.initials: M
authors.lastname: Khanna
authors.forename: Nathan M
authors.initials: NM
authors.lastname: Hammes
authors.forename: Brian C
authors.initials: BC
authors.lastname: Samuels
authors.forename: Fletcher A
authors.initials: FA
authors.lastname: White
authors.forename: Rajesh
authors.initials: R
authors.lastname: Khanna
mesh_terms: D000818:Animals; D020864:Calcium Channels, N-Type / Q000235:genetics / Q000378:metabolism*; D059350:Chronic Pain / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D007249:Inflammation / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D036341:Intercellular Signaling Peptides and Proteins; D008881:Migraine Disorders / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000494:pharmacology*; D017354:Point Mutation; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D020426:Sciatic Neuropathy / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D013979:Tibial Nerve / Q000293:injuries; D020429:Tibial Neuropathy / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: C503279:Cacna1b protein, rat; D020864:Calcium Channels, N-Type; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; C095114:collapsin response mediator protein-2