On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats

<p>Abstract</p> <p>Background</p> <p>The neuropeptide, calcitonin gene-related peptide (CGRP) has been proposed to be a regulator of the development of morphine analgesic tolerance and thereby could be a target to reduce the induction of this phenomenon under clinical c...

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Main Authors: Quirion Remi, Chabot Jean-Guy, Wang Zhiyong
Format: Article
Language:English
Published: SAGE Publishing 2011-09-01
Series:Molecular Pain
Subjects:
Online Access:http://www.molecularpain.com/content/7/1/68
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author Quirion Remi
Chabot Jean-Guy
Wang Zhiyong
author_facet Quirion Remi
Chabot Jean-Guy
Wang Zhiyong
author_sort Quirion Remi
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>The neuropeptide, calcitonin gene-related peptide (CGRP) has been proposed to be a regulator of the development of morphine analgesic tolerance and thereby could be a target to reduce the induction of this phenomenon under clinical conditions. However, the mechanisms of CGRP regulation are unclear. We investigated here the possible role of the extracellular signal-regulated protein kinase (ERK), p38 and calcium/calmodulin-dependent protein kinase II (CaMKII) in CGRP regulation following chronic morphine treatment.</p> <p>Results</p> <p>A 7-day treatment with morphine (15 μg/day) led to an increase in CGRP contents in the spinal cord dorsal horn (SCDH) and dorsal root ganglion (DRG) and this effect was prevented by the inhibition of the ERK, p38 or CaMKII pathway. The phosphorylation/activation of ERK, p38 and CaMKII was enhanced in the SCDH following chronic morphine while in DRG only the phosphorylation of CaMKII was increased. Moreover, our chronic morphine treatment up-regulated neuronal nitric oxide synthase (nNOS) levels in the SCDH, an effect blocked by the inhibition of the ERK, p38 or CaMKII pathway. The blockade of nNOS activity also suppressed chronic morphine-induced CGRP increases in the DRG and SCDH. Double immunofluorescence studies revealed that nNOS and CaMKII are co-localized in the SCDH and that CaMKII is activated in CGRP-expressing DRG neurons.</p> <p>Conclusions</p> <p>The activation of spinal ERK, p38 and CaMKII, alongside nNOS, is involved in chronic morphine-induced CGRP up-regulation in both the DRG and SCDH. Moreover, the stimulation of CaMKII in the DRG likely directly regulates the expression of CGRP associated with morphine analgesic tolerance.</p>
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spelling doaj.art-dae7c5fdcb484d66a4db0b5b8bac48dd2022-12-22T01:06:53ZengSAGE PublishingMolecular Pain1744-80692011-09-01716810.1186/1744-8069-7-68On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant ratsQuirion RemiChabot Jean-GuyWang Zhiyong<p>Abstract</p> <p>Background</p> <p>The neuropeptide, calcitonin gene-related peptide (CGRP) has been proposed to be a regulator of the development of morphine analgesic tolerance and thereby could be a target to reduce the induction of this phenomenon under clinical conditions. However, the mechanisms of CGRP regulation are unclear. We investigated here the possible role of the extracellular signal-regulated protein kinase (ERK), p38 and calcium/calmodulin-dependent protein kinase II (CaMKII) in CGRP regulation following chronic morphine treatment.</p> <p>Results</p> <p>A 7-day treatment with morphine (15 μg/day) led to an increase in CGRP contents in the spinal cord dorsal horn (SCDH) and dorsal root ganglion (DRG) and this effect was prevented by the inhibition of the ERK, p38 or CaMKII pathway. The phosphorylation/activation of ERK, p38 and CaMKII was enhanced in the SCDH following chronic morphine while in DRG only the phosphorylation of CaMKII was increased. Moreover, our chronic morphine treatment up-regulated neuronal nitric oxide synthase (nNOS) levels in the SCDH, an effect blocked by the inhibition of the ERK, p38 or CaMKII pathway. The blockade of nNOS activity also suppressed chronic morphine-induced CGRP increases in the DRG and SCDH. Double immunofluorescence studies revealed that nNOS and CaMKII are co-localized in the SCDH and that CaMKII is activated in CGRP-expressing DRG neurons.</p> <p>Conclusions</p> <p>The activation of spinal ERK, p38 and CaMKII, alongside nNOS, is involved in chronic morphine-induced CGRP up-regulation in both the DRG and SCDH. Moreover, the stimulation of CaMKII in the DRG likely directly regulates the expression of CGRP associated with morphine analgesic tolerance.</p>http://www.molecularpain.com/content/7/1/68CGRPERKp38CaMKIImorphine
spellingShingle Quirion Remi
Chabot Jean-Guy
Wang Zhiyong
On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
Molecular Pain
CGRP
ERK
p38
CaMKII
morphine
title On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
title_full On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
title_fullStr On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
title_full_unstemmed On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
title_short On the possible role of ERK, p38 and CaMKII in the regulation of CGRP expression in morphine-tolerant rats
title_sort on the possible role of erk p38 and camkii in the regulation of cgrp expression in morphine tolerant rats
topic CGRP
ERK
p38
CaMKII
morphine
url http://www.molecularpain.com/content/7/1/68
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