Antinociceptive effect of antisense oligonucleotides against the vanilloid receptor VR1/TRPV1.
To examine the role of the vanilloid receptor TRPV1 in neuropathic pain, we assessed the effects of the receptor antagonist thioxo-BCTC and antisense oligonucleotides against the TRPV1 mRNA in a rat model of spinal nerve ligation. In order to identify accessible sites on the mRNA of TRPV1, the RNase H assay was used, leading to the successful identification of binding sites for antisense oligonucleotides. Cotransfection studies using Cos-7 cells were employed to identify the most effective antisense oligonucleotide efficiently inhibiting the expression of a fusion protein consisting of TRPV1 and the green fluorescent protein in a specific and concentration-dependent manner. In an in vivo rat model of spinal nerve ligation, intravenous application of the TRPV1 antagonist thioxo-BCTC reduced mechanical hypersensitivity yielding an ED(50) value of 10.6mg/kg. Intrathecal administration of the antisense oligonucleotide against TRPV1, but not the mismatch oligonucleotide or a vehicle control, reduced mechanical hypersensitivity in rats with spinal nerve ligation in a similar manner. Immunohistochemical analysis revealed neuropathy- and antisense-associated regulation of TRPV1 protein expression in spinal cord and dorsal root ganglia. Our data demonstrate comparative analgesic effects of a TRPV1 anatagonist and a rationally designed TRPV1 antisense oligonucleotide in a spinal nerve ligation model of neuropathic pain and thus, lend support to the validation of TRPV1 as a promising target for the treatment of neuropathic pain.
Christoph
Thomas
T
Research & Development, Grünenthal GmbH, Zieglerstr. 6, 52078 Aachen, Germany. thomas.christoph@grunenthal.de
Gillen
Clemens
C
Mika
Joanna
J
Grünweller
Arnold
A
Schäfer
Martin K-H
MK
Schiene
Klaus
K
Frank
Robert
R
Jostock
Ruth
R
Bahrenberg
Gregor
G
Weihe
Eberhard
E
Erdmann
Volker A
VA
Kurreck
Jens
J
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D019556:COS Cells; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D017931:DNA Primers; D007150:Immunohistochemistry; D008297:Male; D008856:Microscopy, Fluorescence; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism; D050916:TRPV Cation Channels / Q000187:drug effects*
D000700:Analgesics; D017931:DNA Primers; D016376:Oligonucleotides, Antisense; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat