[Abstract Title]. - Society for Neuroscience

stably expressing trkA receptors we explored modulation of TRPV1 by NGF. In whole-cell
recordings of capsaicin evoked currents from F11 cells, 100ng/ml NGF acutely increased current
amplitude. However, NGF mediated TRPV1 sensitization was not observed in HEK293-trkA
cells. Accordingly, Western blot analysis revealed HEK293 cells to express significantly lower
levels of PKC epsilon than F11 cells. We propose that PKC epsilon is an important molecule that
is involved in NGF mediated TRPV1 sensitization. Following treatment of adult DRG neurons
for 10-30 minutes with 100ng/ml NGF, serine phosphorylation of immunoprecipitated native
TRPV1 was increased (Western blot with phosphoserine antibodies). We are investigating the
PKC specific TRPV1 phosphorylation events using mass spectrometry of TRPV1 from native rat
DRG neurons following NGF treatment. Furthermore, we are comparing wildtype and p-site
mutant TRPV1 for sensitization in cells coexpressing trkA and TRPV1 constructs.
Disclosures: W. Song , None; W. Zhu, None; G. Oxford, None.
Poster
265. Nociceptors II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 265.11/EE12
Topic: D.08.a. Pain transduction molecules and channels
Support: NIH grant NS40723
Title: Up-regulation of transient receptor potential vanilloid-1 in primary afferent neurons is
mediated by protein kinase C and involved in neurogenic inflammation
Authors: *X. XU 1 , P. WANG 1 , X. ZOU 1 , D. LI 1 , L. FANG 2 , Q. LI 2 ;
1 Neurosci & Cell Biol, 2 Surgery, UTMB, Galveston, TX
Abstract: A recent study by our group indicated that the transient receptor potential vanilloid-1
(TRPV1) is activated by intradermal injection of capsaicin (CAP) to initiate neurogenic
inflammation by the release of neuropeptides in the periphery. In order to investigate further
whether up-regulation of TRPV1 in dorsal root ganglion (DRG) neurons following CAP injection
is subject to modulation by the phosphorylated protein kinase C (p-PKC) and whether this
participates in neurogenic inflammation, immunohistochemistry, real-time PCR and Western
blots were used to examine the molecular and cellular changes that occur in the expression of
TRPV1, p-PKC and calcitonin gene-related peptide (CGRP) in DRG neurons following CAP
injection in anesthetized rats. Results show that CAP injection evoked increases in the expression
of TRPV1 both in mRNA and protein levels and in the numbers of single labeled TRPV1, p-PKC
and CGRP neurons in ipsilateral L4-5 DRG. Co-expressions of TRPV1 with p-PKC and/or CGRP