P17 induces chemotaxis and differentiation of monocytes via MRGPRX2-mediated mast cell–line activation

Journal of allergy and clinical immunology, ~14.11 (IF)

Karthi Duraisamy, Kailash Singh, Mukesh Kumar, Benjamin Lefranc, Elsa Bonnafe, Michel Treilhou, Jerome Leprince and Billy K. C. Chow, (Hong Kong, China; and Rouen and Albi, France).

Abstract

Background: P17, a peptide isolated from Tetramorium bicarinatum ant venom, is known to induce an alternative phenotype of human monocyte–derived macrophages via activation of an unknown G protein–coupled receptor (GPCR).

Objective: We sought to investigate the mechanism of action and the immunomodulatory effects of P17 mediated through MRGPRX2 (Mas related G protein–coupled receptor X2).

Methods: To identify the GPCR for P17, we screened 314 GPCRs. Upon identification of MRGPRX2, a battery of in silico, in vitro, ex vivo, and in vivo assays along with the receptor mutation studies were performed. In
particular, to investigate the immunomodulatory actions, we used b-hexosaminidase release assay, cytokine releases, quantification of mRNA expression, cell migration and differentiation assays,
immunohistochemical labeling, hematoxylin and eosin, and immunofluorescence staining.

Results: P17 activated MRGPRX2 in a dose-dependent manner in b-arrestin recruitment assay. In LAD2 cells, P17 induced calcium and b-hexosaminidase release. Quercetin- and short hairpin RNA–mediated knockdown of MRGPRX2 reduced P17- evoked b-hexosaminidase release. In silico and in vitro mutagenesis studies showed that residue Lys8 of P17 formed a cation-p interaction with the Phe172 of MRGPRX2 and [Ala8
] P17 lost its activity partially. P17 activated LAD2 cells to recruit THP-1 and human monocytes in Transwell migration assay, whereas MRGPRX2-impaired LAD2 cells cannot. In addition, P17-treated LAD2 cells stimulated differentiation of THP-1 and human monocytes, as indicated by the enhanced expression of macrophage markers cluster of differentiation 11b and TNF-α by quantitative RT-PCR. Immunohistochemical and immunofluorescent staining suggested monocyte recruitment in mice ears injected with P17.

Conclusion: Our data provide novel structural information regarding the interaction of P17 with MRGPRX2 and intracellular pathways for its immunomodulatory action.

Supplementary datas:-

Analysis of TRPV channel activation by stimulation of FCεRI and MRGPR receptors in mouse peritoneal mast cells

A. Sol ́ıs-Lo ́ pez1, U. Kriebs1, A. Marx1, S. Mannebach2, W. B. Liedtke3, M. J. Caterina4, M. Freichel1, V. V. Tsvilovskyy1*

1 PharmakologischesInstitut,Ruprecht-Karls-Universita ̈tHeidelberg,Heidelberg,Baden-Wu ̈rttemberg, Germany, 2 Experimentelle und Klinische Pharmakologie und Toxikologie, Universita ̈t des Saarlandes, Homburg, Saarland, Germany, 3 Department of Neurology, School of Medicine Duke University, Durham, North Carolina, United States of America, 4 Departments of Neurosurgery, Biological Chemistry, and Neuroscience, Neurosurgery Pain Research Institute, The Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America

Abstract

The activation of mast cells (MC) is part of the innate and adaptive immune responses and depends on Ca2+ entry across the plasma membrane, leading to the release of preformed inflammatory mediators by degranulation or by de novo synthesis. The calcium conducting channels of the TRPV family, known by their thermo and osmotic sensitivity, have been pro- posed to be involved in the MC activation in murine, rat, and human mast cell models. So far, immortalized mast cell lines and nonspecific TRPV blockers have been employed to charac- terize the role of TRPV channels in MC. The aim of this work was to elucidate the physiological role of TRPV channels by using primary peritoneal mast cells (PMCs), a model of connective tissue type mast cells. Our RT-PCR and NanoString analysis identified the expression of TRPV1, TRPV2, and TRPV4 channels in PMCs. For determination of the functional role of the expressed TRPV channels we performed measurements of intracellular free Ca2+ concentra- tions and beta-hexosaminidase release in PMCs obtained from wild type and mice deficient for corresponding TRPV1, TRPV2 and TRPV4 in response to various receptor-mediated and physical stimuli. Furthermore, substances known as activators of corresponding TRPV-chan- nels were also tested using these assays. Our results demonstrate that TRPV1, TRPV2, and TRPV4 do not participate in activation pathways triggered by activation of the high-affinity receptors for IgE (FcεRI), Mrgprb2 receptor, or Endothelin-1 receptor nor by heat or osmotic stimulation in mouse PMCs.

The TRPM3 ion channel mediates nociception but not itch evoked by endogenous pruritogenic mediators

Biochemical Pharmacology, ~ 5.0 (IF)

BalázsKelemen, SilviaPinto, NawooKim, ErikaLisztes, MartinHanyicska, AnitaVladár, AttilaOláh, ZsófiaPénzes, BrianShu, JorisVriens, TamásBíró, TiborRohács, ThomasVoets, Balázs IstvánTóth

Abstract

During the molecular transduction of itch, the stimulation of pruriceptors on sensory fibers leads to the activation or sensitization of ion channels, which results in a consequent depolarization of the neurons. These ion channels mostly belong to the transient receptor potential (TRP) channels, which are involved in nociception and thermosensation. In particular, TRPV1 and TRPA1 were described in the transduction of both thermal nociception as well as histaminergic and non-histaminergic itch. The thermosensitive TRPM3 plays an indispensable role in heat nociception together with TRPV1 and TRPA1. However, the role of TRPM3 in the development of pruritus has not been studied yet. Therefore, in this study we aimed at investigating the potential role of TRPM3 in the transduction of pruritus and pain by investigating itch- and nociception-related behavior of Trpm3^+/+ and Trpm3^−/− mice, and by studying the activation of somatosensory neurons isolated from trigeminal ganglia upon application of algogenic and pruritogenic substances. Activators of TRPM3 evoked only nocifensive responses, but not itch in Trpm3^+/+ animals, and these nocifensive responses were abolished in the Trpm3^−/− strain. Histamine and endogenous non-histaminergic pruritogens induced itch in both Trpm3^+/+and Trpm3^−/− mice to a similar extent. Genetic deletion or pharmacological blockade diminished TRPM3 mediated Ca²⁺ responses of sensory neurons, but did not affect responses evoked by pruritogenic substances. Our results demonstrate that, in contrast to other thermosensitive TRP channels, TRPM3 selectively mediates nociception, but not itch sensation, and suggest that TRPM3 is a promising candidate to selectively target pain sensation.

Quorum sensing between bacterial species on the skin protects against epidermal injury in atopic dermatitis

Michael R. Williams, Stephen K. Costa, Livia S. Zaramela, Shadi Khali, Daniel A. Todd, Heather L. Winter

published in Science Translational Medicine, 01 May 2019

Abstract

Colonization of the skin by Staphylococcus aureus is associated with exacerbation of atopic dermatitis (AD), but any direct mechanism through which dysbiosis of the skin microbiome may influence the development of AD is unknown. Here, we show that proteases and phenol-soluble modulin α (PSMα) secreted by S. aureus lead to endogenous epidermal proteolysis and skin barrier damage that promoted inflammation in mice. We further show that clinical isolates of different coagulase-negative staphylococci (CoNS) species residing on normal skin produced autoinducing peptides that inhibited the S. aureus agr system, in turn decreasing PSMα expression. These autoinducing peptides from skin microbiome CoNS species potently suppressed PSMα expression in S. aureus isolates from subjects with AD without inhibiting S. aureus growth. Metagenomic analysis of the AD skin microbiome revealed that the increase in the relative abundance of S. aureus in patients with active AD correlated with a lower CoNS autoinducing peptides to S. aureus ratio, thus overcoming the peptides’ capacity to inhibit the S. aureus agr system. Characterization of a S. hominis clinical isolate identified an autoinducing peptide (SYNVCGGYF) as a highly potent inhibitor of S. aureus agr activity, capable of preventing S. aureus–mediated epithelial damage and inflammation on murine skin. Together, these findings show how members of the normal human skin microbiome can contribute to epithelial barrier homeostasis by using quorum sensing to inhibit S. aureus toxin production.

MRGPRX2 Is the Codeine Receptor of Human Skin Mast Cells: Desensitization through β-Arrestin and Lack of Correlation with the FcεRI Pathway

Magda Babina, Zhao Wang, Saptarshi Roy, Sven Guhl, Kristin Franke, Metin Artuc, Hydar Ali and Torsten Zuberbier

Published in: Journal of Investigative Dermatology

DOI: 10.1016/j.jid.2020.09.017

Abstract

Codeine stimulates skin mast cells and is therefore used in skin tests and as an inducer of experimental itch. MRGPRX2 responds to various drugs, including opioids, to elicit pseudoallergic reactions, but whether it represents the main opiate receptor of skin mast cells remains unknown. By combining a number of approaches, including the silencing of MRGPRX2, we now report that MRGPRX2 is indeed the dominant codeine receptor of dermal mast cells. Activation by codeine displayed profound subject variability and correlated with secretion elicited by compound 48/80 or substance P but not by FcεRI aggregation. Degranulation by codeine was attenuated by stem cell factor, whereas the opposite was found for FcεRI. Compound 48/80 or codeine alone was able to achieve maximum MRGPRX2 activation. MRGPRX2 was rapidly internalized on codeine binding in a b arrestin-1‒dependent manner. Codeine-triggered b-arrestin activation was also established by the Tango assay. Prestimulation with MRGPRX2 agonists (but not C3a or FcεRI aggregation) resulted in refractoriness to further stimulation by the same or another MRGPRX2 ligand (cross desensitization). This was duplicated in a cell line (RBL-MRGPRX2). Collectively, codeine degranulates skin mast cells through MRGPRX2, at which it acts as a balanced ligand. It has yet to be determined whether codeine-induced refractoriness could be exploited to desensitize MRGPRX2 to prevent severe pseudoallergic reactions.

MrgprB4 in trigeminal neurons expressing TRPA1 modulates unpleasant sensations

Shota Tobori a, 1, Haruka Hiyama a, 1, Takahito Miyake a, b, Yuichi Yano a, Kazuki Nagayasu a, Hisashi Shirakawa a, *, Takayuki Nakagawa c, Yasuo Mori d, Shuji Kaneko a

a Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
b Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606- 8501, Japan

c Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, 54 Shogoin -Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
d Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Building A4, Katsura Campus, Nishikyo-ku, Kyoto 615-8510, Japan

ABSTRACT

Gentle touch such as stroking of the skin produces a pleasant feeling, which is detected by a rare subset of sensory neurons that express Mas-related G protein-coupled receptor B4 (MrgprB4) in mice. We examined small populations of MrgprB4-positive neurons in the trigeminal ganglion and the dorsal root ganglion, and most of these were sensitive to transient receptor potential ankyrin 1 (TRPA1) agonist but not TRPV1, TRPM8, or TRPV4 agonists. Deficiency of MrgprB4 did not affect noxious pain or itch be- haviors in the hairless plantar and hairy cheek. Although behavior related to acetone-induced cold sensing in the hind paw was not changed, unpleasant sensory behaviors in response to acetone appli- cation or sucrose splash to the cheek were significantly enhanced in Mrgprb4-knockout mice as well as in TRPA1-knockout mice. These results suggest that MrgprB4 in the trigeminal neurons produces pleasant sensations in cooperation with TRPA1, rather than noxious or cold sensations. Pleasant sensa- tions may modulate unpleasant sensations on the cheek via MrgprB4.

© 2021 The Authors. Production and hosting by Elsevier B.V. on behalf of Japanese Pharmacological Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Keywords:

Sensory behavior Hairy skin
MrgprB4
TRPA1
Trigeminal ganglion

Hierarchical Specification of Pruriceptors by Runt-Domain Transcription Factor Runx1

Lu Qi, Chengcheng Huang, Xiaohua Wu, Yeqi Tao, Jingjing Yan, Tianyong Shi, Cheng Cao, Lu Han, Mengsheng Qiu, Qiufu Ma, Zijing Liu , Yang Liu 

The Journal of Neuroscience, May 31, 2017

Abstract

The somatic sensory neurons in dorsal root ganglia (DRG) detect and transmit a diverse array of sensory modalities, such as pain, itch, cold, warm, touch, and others. Recent genetic and single-cell RNA sequencing studies have revealed a group of DRG neurons that could be particularly relevant for acute and chronic itch information transmission. They express the natriuretic peptide type B (NPPB), as well as a cohort of receptors and neuropeptides that have been implicated in chronic itch manifestation, including the interleukin-31 receptor A (IL-31ra) and its coreceptor oncostatin M receptor (Osmr), the cysteinyl leukotriene receptor 2 (Cysltr2), somatostatin, and neurotensin. However, how these neurons are generated during development remains unclear. Here we report that Runx1 is required to establish all these molecular features of NPPB⁺ neurons. We further show that while early embryonic Runx1 activity is required for the formation of NPPB⁺ cells, at later stages Runx1 switches to a genetic repressor and thus its downregulation becomes a prerequisite for the proper development of these pruriceptors. This mode by Runx1 is analogous to that in controlling another group of pruriceptors that specifically express the chloroquine receptor MrgprA3. Finally, behavioral studies using both sexes of mice revealed marked deficits in processing acute and chronic itch in Runx1 conditional knock-out mice, possibly attributable to impaired development of various pruriceptors.

SIGNIFICANCE STATEMENT 

Our studies reveal a generalized control mode by Runx1 for pruriceptor development and consolidate a hierarchical control mechanism for the formation of sensory neurons transmitting distinct modalities. Among dorsal root ganglion neurons that initially express the neurotrophin receptor TrkA, Runx1 is necessary for the proper development of those neurons that innervate tissues derived from the ectoderm such as skin epidermis and hair follicles. These Runx1-dependent cutaneous sensory neurons are then divided into two groups based on persistent or transient Runx1 expression. The Runx1-persistent group is involved in transmitting mechanical and thermal information, whereas the Runx1-transient group transmits pruriceptive information. Such hierarchical control mechanisms may provide a developmental solution for the formation of sensory circuits that transmit distinct modalities.

Keywords: NPPB; Runx1; chronic itch; development; pruriceptor; transcriptional regulation.

Cimifugin relieves pruritus in psoriasis by inhibiting TRPV4

Published in:- Cell Calcium

JinjinYan^aFanYe^aYingJu^aDijunWang^aJiaoChen^bcXinyuZhang^aZhiYin^dChangmingWang^aYanYang^aChanZhu^aYuanZhou^aPengCao^bcYangXu^dGuangYu^aZongxiangTang^a

DOI: https://doi.org/10.1016/j.ceca.2021.102429

Psoriasis is an immune-mediated chronic inflammatory skin disease characterized by erythema, scales, and infiltration of the skin, which causes deleterious effects on patient quality of life. TRP channel played important roles in the generation and conductance of itch signal . According to our results, psoriasis induced itch was TRPV4 dependent, and TRPV4 expression in both epidermis and DRG were up-regulated in psoriasis. Thus, TRPV4 is an attractive candidate for treating psoriasis induced itch. Cimifugin is a common compound in antipruritic Chinese medicine. In our study, GSK1016790A, a TRPV4 channel specific agonist, induced acute itch was inhibited by cimifugin in a dose-dependent manner. Furthermore, cimifugin treatment reduced the scratching behavior and reversed the TRPV4 up-regulation induced by psoriasis. In particular, cimifugin decreased GSK1016790A induced calcium response both in HaCaT cells and DRG neurons. Importantly, in TRPV4 transfected HEK293 cells, GSK101 induced calcium response was also significantly inhibited by cimifugin pretreatment. Consistent with our calcium imaging result, cimifugin pretreatment also inhibited GSK101 induced inward currents. Our study delineated a new role of TRPV4 in psoriasis and emphasized the antipruritic effect of cimifugin, which opened a new avenue to itch management in psoriasis.

Keyword: Psoriasis, Trpv4, Itch, Cimifugin

MrgprC11+ sensory neurons mediate glabrous skin itch

Proc Natl Acad Sci U S A. 2021 Apr 13;118(15):e2022874118. doi: 10.1073/pnas.2022874118.

Haley R. Steele, Yanyan Xinga, Yuyan Zhu, Henry B. Hilley, Katy Lawson, Yeseul Nho, Taylor Niehoff, and Liang Hana

School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
Edited by Jeremy Nathans, Johns Hopkins University School of Medicine, Baltimore, MD, and approved March 2, 2021 (received for review November 2, 2020)

Itch arising from glabrous skin (palms and soles) has attracted limited attention within the field due to the lack of methodology. This is despite glabrous itch arising from many medical conditions such as plantar and palmar psoriasis, dyshidrosis, and cholestasis. Therefore, we developed a mouse glabrous skin behavioral assay to investigate the contribution of three previously identified pruriceptive neurons in glabrous skin itch. Our results show that MrgprA3+ and MrgprD+ neurons, although key mediators for hairy skin itch, do not play important roles in glabrous skin itch, dem- onstrating a mechanistic difference in itch sensation between hairy and glabrous skin. We found that MrgprC11+ neurons are the major mediators for glabrous skin itch. Activation of MrgprC11+ neurons induced glabrous skin itch, while ablation of MrgprC11+ neurons reduced both acute and chronic glabrous skin itch. Our study provides insights into the mechanisms of itch and opens up new avenues for future glabrous skin itch research.

Runx1 Determines Nociceptive Sensory Neuron Phenotype and Is Required for Thermal and Neuropathic Pain

Chih-Li Chen, Daniel C Broom, Yang Liu, Joriene C de Nooij, Zhe Li, Chuan Cen, Omar Abdel Samad, Thomas M Jessell, Clifford J Woolf, Qiufu Ma

Abstract

In mammals, the perception of pain is initiated by the transduction of noxious stimuli through specialized ion channels and receptors expressed by nociceptive sensory neurons. The molecular mechanisms responsible for the specification of distinct sensory modality are, however, largely unknown. We show here that Runx1, a Runt domain transcription factor, is expressed in most nociceptors during embryonic development but in adult mice, becomes restricted to nociceptors marked by expression of the neurotrophin receptor Ret. In these neurons, Runx1 regulates the expression of many ion channels and receptors, including TRP class thermal receptors, Na+-gated, ATP-gated, and H+-gated channels, the opioid receptor MOR, and Mrgpr class G protein coupled receptors. Runx1 also controls the lamina-specific innervation pattern of nociceptive afferents in the spinal cord. Moreover, mice lacking Runx1 exhibit specific defects in thermal and neuropathic pain. Thus, Runx1 coordinates the phenotype of a large cohort of nociceptors, a finding with implications for pain therapy.