Chronic itch development in sensory neurons requires BRAF signaling pathways

Zhong-Qiu Zhao,1,2 Fu-Quan Huo,1,2 Joseph Jeffry,1,2 Lori Hampton,3 Shadmehr Demehri,4,5 Seungil Kim,1 Xian-Yu Liu,1,2 Devin M. Barry,1,5 Li Wan,1,6 Zhong-Chun Liu,1,2 Hui Li,1,7 Ahu Turkoz,4 Kaijie Ma,8 Lynn A. Cornelius,1,5 Raphael Kopan,4 James F. Battey Jr.,9
Jian Zhong,8,10 and Zhou-Feng Chen1,2,4

1Center for the Study of Itch and 2Departments of Anesthesiology and Psychiatry, Washington University School of Medicine Pain Center,
St. Louis, Missouri, USA. 3Office of Laboratory Animal Welfare, NIH, Bethesda, Maryland, USA. 4Department of Developmental Biology and 5Division of Dermatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. 6Department of Anesthesiology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
7Department of Anatomy, Histology, and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi’an, China. 8Burke Medical Research Institute, Weill Medical College of Cornell University, White Plains, New York, USA.
9National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA.
10Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, New York, USA.

Chronic itch, or pruritus, is associated with a wide range of skin abnormalities. The mechanisms responsible for chronic itch induction and persistence remain unclear. We developed a mouse model in which a constitutively active form of the serine/threonine kinase BRAF was expressed in neurons gated by the sodium channel Nav1.8 (BRAFNav1.8 mice). We found that constitutive BRAF pathway activation in BRAFNav1.8 mice results in ectopic and enhanced expression of a cohort of itch-sensing genes, including gastrin-releasing peptide (GRP) and MAS-related GPCR member A3 (MRGPRA3), in nociceptors expressing transient receptor potential vanilloid 1 (TRPV1). BRAFNav1.8 mice showed de novo neuronal responsiveness to pruritogens, enhanced pruriceptor excit- ability, and heightened evoked and spontaneous scratching behavior. GRP receptor expression was increased in the spinal cord, indicating augmented coding capacity for itch subsequent to amplified pruriceptive inputs. Enhanced GRP expression and sustained ERK phosphorylation were observed in sensory neurons of mice with allergic contact dermatitis– or dry skin–elicited itch; however, spinal ERK activation was not required for main- taining central sensitization of itch. Inhibition of either BRAF or GRP signaling attenuated itch sensation in chronic itch mouse models. These data uncover RAF/MEK/ERK signaling as a key regulator that confers a subset of nociceptors with pruriceptive properties to initiate and maintain long-lasting itch sensation.

Journal club 2013-11-29 Read More »

Journal club 2013-11-22

Won-Sik Shim

: Filename : 1-s2-0-s0014299912003585-main.pdf (401 KB)
Caption :

Eur J Pharmacol. 2012 Jul 5;686(1-3):16-21. doi: 10.1016/j.ejphar.2012.04.024. Epub 2012 Apr 21.

Cathepsin E induces itch-related response through the production of endothelin-1 in mice.

Andoh T, Yoshida T, Lee JB, Kuraishi Y.

Source

Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Japan.

Abstract

This study investigated the pruritogenic potency of cathepsin E, an aspartic protease, and its mechanisms in mice. An intradermal injection of cathepsin E to the rostral back elicited scratching, an itch-associated response, of the injection site. This action was inhibited by the aspartic protease inhibitor pepstatin A, the endothelin ET(A) receptor antagonist BQ-123, and the opioid receptor antagonists naltrexone and naloxone, but not by the H(1) histamine receptor antagonist terfenadine, the proteinase-activated receptor-2 antagonist FSLLRY-NH(2), or mast cell deficiency. Pepstatin A inhibited scratching induced by intradermal injection of the mast-cell degranulator compound 48/80, but not by tryptase, a mast-cell mediator. An intradermal injection of cathepsin E increased endothelin-1 levels in the skin at the injection site. Preproendothelin-1 mRNA was present in primary cultures of keratinocytes, and immunohistochemistry using an antibody recognizing endothelin-1 and big-endothelin-1 revealed immunoreactivity in the epidermis, especially in the prickle and granular cell layers, but not in the basal cell layer. These results suggest that cathepsin E is an endogenous itch inducer, and that its action is mediated at least in part by the production of endothelin-1 in the epidermis.

PMID:: 22546226; [PubMed – indexed for MEDLINE]

Journal club 2013-11-22 Read More »

journal 2013-11-15

somi2388

all2854

The antagonism of histamine H1 and H4 receptors ameliorates chronic allergic dermatitis via anti-pruritic and anti-inflammatory effects in NC/Nga mice.

Ohsawa Y, Hirasawa N.

Source

Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. yuusuke_oosawa@pharm.kissei.co.jp

Abstract

BACKGROUND:

Although histamine H1 receptor (H1R) antagonists are commonly used to treat atopic dermatitis, the treatment is not always effective. The histamine H4 receptor (H4R) was recently described as important to the pruritus in dermatitis. Here, we investigated whether the combination of a H1R antagonist plus a H4R antagonist attenuates chronic dermatitis in NC/Nga mice.

METHODS:

Chronic dermatitis was developed by repeated challenges with picryl chloride on the dorsal back and ear lobes. The therapeutic effects of the H1R antagonist olopatadine and H4R antagonist JNJ7777120 on scratching and the severity of dermatitis were evaluated. In addition, the mechanisms responsible for the anti-allergic effects of H1R and/or H4R antagonism were examined using bone marrow-derived mast cells (BMMC) and keratinocytes.

RESULTS:

JNJ7777120 attenuated scratching behavior after a single administration and improved dermatitis, as assessed with clinical scores, pathology, and cytokine levels in skin lesions when administered repeatedly. These effects were augmented by combined treatment with olopatadine, having a similar therapeutic efficacy to prednisolone. JNJ7777120 inhibited dose-dependently the production of thymus and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 from antigen-stimulated BMMC. In addition, olopatadine reversed the histamine-induced reduction of semaphorin 3A mRNA in keratinocytes.

CONCLUSION:

Combined treatment with H1R and H4R antagonists may have a significant therapeutic effect on chronic dermatitis through the synergistic inhibition of pruritus and skin inflammation.

journal 2013-11-15 Read More »

Journal club 2013-11-15

Won-Sik Shim

: Filename : all2854.pdf (808 KB)
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Allergy. 2012 Aug;67(8):1014-22. doi: 10.1111/j.1398-9995.2012.02854.x. Epub 2012 Jun 12.

The antagonism of histamine H1 and H4 receptors ameliorates chronic allergic dermatitis via anti-pruritic and anti-inflammatory effects in NC/Nga mice.

Ohsawa Y, Hirasawa N.

Source

Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. yuusuke_oosawa@pharm.kissei.co.jp

Abstract

BACKGROUND:

METHODS:

RESULTS:

CONCLUSION:

Combined treatment with H1R and H4R antagonists may have a significant therapeutic effect on chronic dermatitis through the synergistic inhibition of pruritus and skin inflammation.

PMID:: 22686688; [PubMed – indexed for MEDLINE]

Journal club 2013-11-15 Read More »

Journal club 2013-11-01

somi2388

The Star-Nosed Mole Reveals Clues to the Molecular Basis of Mammalian Touch

Abstract

Little is known about the molecular mechanisms underlying mammalian touch transduction. To identify novel candidate transducers, we examined the molecular and cellular basis of touch in one of the most sensitive tactile organs in the animal kingdom, the star of the star-nosed mole. Our findings demonstrate that the trigeminal ganglia innervating the star are enriched in tactile-sensitive neurons, resulting in a higher proportion of light touch fibers and lower proportion of nociceptors compared to the dorsal root ganglia innervating the rest of the body. We exploit this difference using transcriptome analysis of the star-nosed mole sensory ganglia to identify novel candidate mammalian touch and pain transducers. The most enriched candidates are also expressed in mouse somatosesensory ganglia, suggesting they may mediate transduction in diverse species and are not unique to moles. These findings highlight the utility of examining diverse and specialized species to address fundamental questions in mammalian biology.

Citation: Gerhold KA, Pellegrino M, Tsunozaki M, Morita T, Leitch DB, et al. (2013) The Star-Nosed Mole Reveals Clues to the Molecular Basis of Mammalian Touch. PLoS ONE 8(1): e55001. doi:10.1371/journal.pone.0055001

Editor: Michael N. Nitabach, Yale School of Medicine, United States of America

Received: October 10, 2012; Accepted: December 21, 2012; Published: January 30, 2013

Copyright: © 2013 Gerhold et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: The authors are supported by a U.S. National Institutes of Health Innovator Award DOD007123A, the Pew Scholars Program, and the McKnight Scholars Fund (to DMB) and NSF grant 0844743 (to KCC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
journal.pone.0055001

Journal club 2013-11-01 Read More »

Journal Club 2013-10-11

WOOK-JOO LEE

The Epithelial Cell-Derived Atopic Dermatitis Cytokine TSLP Activates Neurons to Induce Itch

Sarah R. Wilson,1,2,3 Lydia The ́ ,1,3 Lyn M. Batia,1 Katherine Beattie,1 George E. Katibah,1 Shannan P. McClain,1 Maurizio Pellegrino,1 Daniel M. Estandian,1 and Diana M. Bautista1,2,*
1Department of Molecular and Cell Biology
2Helen Wills Neuroscience Institute

University of California, Berkeley, Berkeley, CA 94720, USA 3These authors contributed equally to this work *Correspondence: dbautista@berkeley.edu

http://dx.doi.org/10.1016/j.cell.2013.08.057

1-s2.0-S009286741301088X-main

SUMMARY

Atopic dermatitis (AD) is a chronic itch and inflamma- tory disorder of the skin that affects one in ten peo- ple. Patients suffering from severe AD eventually progress to develop asthma and allergic rhinitis, in a process known as the ‘‘atopic march.’’ Signaling between epithelial cells and innate immune cells via the cytokine thymic stromal lymphopoietin (TSLP) is thought to drive AD and the atopic march. Here, we report that epithelial cells directly communicate to cutaneous sensory neurons via TSLP to promote itch. We identify the ORAI1/NFAT calcium signaling pathway as an essential regulator of TSLP release from keratinocytes, the primary epithelial cells of the skin. TSLP then acts directly on a subset of TRPA1-positive sensory neurons to trigger robust itch behaviors. Our results support a model whereby calcium-dependent TSLP release by keratinocytes activates both primary afferent neurons and immune cells to promote inflammatory responses in the skin and airways.

Journal Club 2013-10-11 Read More »

Journal club 2013-09-13

somi2388

9554.full

Transient Receptor Potential Canonical 3 (TRPC3) Is Required for IgG Immune Complex-Induced Excitation of the Rat Dorsal Root Ganglion Neurons

Abstract

Chronic pain may accompany immune-related disorders with an elevated level of serum IgG immune complex (IgG-IC), but the underlying mechanisms are obscure. We previously demonstrated that IgG-IC directly excited a subpopulation of dorsal root ganglion (DRG) neurons through the neuronal Fc-gamma receptor I (FcγRI). This might be a mechanism linking IgG-IC to pain and hyperalgesia. The purpose of this study was to investigate the signaling pathways and transduction channels activated downstream of IgG-IC and FcγRI. In whole-cell recordings, IgG-IC induced a nonselective cation current (I_IC) in the rat DRG neurons, carried by Ca²⁺ and Na⁺. The I_IC was potentiated or attenuated by, respectively, lowering or increasing the intracellular Ca²⁺ buffering capacity, suggesting that this current was regulated by intracellular calcium. Single-cell RT-PCR revealed that transient receptor potential canonical 3 (TRPC3) mRNA was always coexpressed with FcγRI mRNA in the same DRG neuron. Moreover, ruthenium red (a general TRP channel blocker), BTP2 (a general TRPC channel inhibitor), and pyrazole-3 (a selective TRPC3 blocker) each potently inhibited the I_IC. Specific knockdown of TRPC3 using small interfering RNA attenuated the IgG-IC-induced Ca²⁺ response and the I_IC. Additionally, the I_IC was blocked by the tyrosine kinase Syk inhibitor OXSI-2, the phospholipase C (PLC) inhibitor neomycin, and either the inositol triphosphate (IP₃) receptor antagonist 2-aminoethyldiphenylborinate or heparin. These results indicated that the activation of neuronal FcγRI triggers TRPC channels through the Syk–PLC–IP₃ pathway and that TRPC3 is a key molecular target for the excitatory effect of IgG-IC on DRG neurons.

Received December 20, 2011.
Revision received May 20, 2012.
Accepted May 23, 2012.

Journal club 2013-09-13 Read More »

Journal club 2013-09-06

WOOK-JOO LEE

Essential Role for TRPC5 in Amygdala Function
and Fear-Related Behavior

1-s2.0-S0092867409003766-main PIIS0092867409003766.mmc1

Antonio Riccio,1,2 Yan Li,3 Jisook Moon,3,5 Kwang-Soo Kim,3 Kiersten S. Smith,3 Uwe Rudolph,3 Svetlana Gapon,1 Gui Lan Yao,2 Evgeny Tsvetkov,3 Scott J. Rodig,4 Ashlee Van’t Veer,3 Edward G. Meloni,3 William A. Carlezon Jr.,3 Vadim Y. Bolshakov,3,* and David E. Clapham1,2,*
1Department of Cardiology, Howard Hughes Medical Institute, Manton Center for Orphan Disease, Children’s Hospital Boston, Boston, MA 02115, USA

2Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
3Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA
4Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA
5Present address: College of Medicine, Pochon CHA University, 606-5 Yeoksam-dong, Gangnam-gu, Seoul 135-081, Republic of Korea *Correspondence: vadimb@mclean.harvard.edu (V.Y.B.), dclapham@enders.tch.harvard.edu (D.E.C.)
DOI 10.1016/j.cell.2009.03.039

SUMMARY

The transient receptor potential channel 5 (TRPC5) is predominantly expressed in the brain where it can form heterotetrameric complexes with TRPC1 and TRPC4 channel subunits. These excitatory, nonse- lective cationic channels are regulated by G protein, phospholipase C-coupled receptors. Here, we show that TRPC5

Journal club 2013-09-06 Read More »

Journal club 2013-08-12

somi2388

1-s2.0-S0143416010001260-main

Cell Calcium. 2010 Oct;48(4):202-8. doi: 10.1016/j.ceca.2010.09.001. Epub 2010 Oct 12.

TRPM8 mediates cold and menthol allergies associated with mast cell activation.

Cho Y, Jang Y, Yang YD, Lee CH, Lee Y, Oh U.

Source

Sensory Research Center, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.

Abstract

Exposure to low temperatures often causes allergic responses or urticaria. Similarly, menthol, a common food additive is also known to cause urticaria, asthma, and rhinitis. However, despite the obvious clinical implications, the molecular mechanisms responsible for inducing allergic responses to low temperatures and menthol have not been determined. Because a non-selective cation channel, transient receptor potential subtype M8 (TRPM8) is activated by cold and menthol, we hypothesized that this channel mediates cold- and menthol-induced histamine release in mast cells. Here, we report that TRPM8 is expressed in the basophilic leukemia mast cell line, RBL-2H3, and that exposure to menthol or low temperatures induced Ca(2+) influx in RBL-2H3 cells, which was reversed by a TRPM8 blocker. Furthermore, menthol, a TRPM8 agonist, induced the dose-dependent release of histamine from RBL-2H3 cells. When TRPM8 transcripts were reduced by siRNA (small interfering RNA), menthol- and cold-induced Ca(2+) influx and histamine release were significantly reduced. In addition, subcutaneous injection of menthol evoked scratching, a typical histamine-induced response which was reversed by a TRPM8 blocker. Thus, our findings indicate that TRPM8 mediates the menthol- and cold-induced allergic responses of mast cells, and suggest that TRPM8 antagonists be viewed as potential treatments for cold- and menthol-induced allergies.

PMID:: 20934218; [PubMed – indexed for MEDLINE]

Journal club 2013-08-12 Read More »