Journal Club 2025.04.25

Mast Cells Initiate Type 2 Inflammation through Tryptase Released by MRGPRX2/MRGPRB2 Activation in Atopic Dermatitis

https://doi.org/10.1016/j.jid.2023.06.201

Tao Jia 13, Delu Che 123, Yi Zheng 1, Huan Zhang 1, Yaxiang Li 1, Tong Zhou 1, Bin Peng 1, Xueshan Du 1, Longfei Zhu 1, Jingang An 1, Songmei Geng 1

1Department of Dermatology, Northwest Hospital, The Second Hospital Affiliated to Xi’an Jiaotong University, Xi’an, China

2Center for Dermatology Disease, Precision Medical Institute, Xi’an, China

Keywords

AD: Atopic Dermatitis, ADI: Atopic Dermatitis Index, MC: Mast Cell, TSLP: Thymic Stromal Lymphopoietin

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Journal club: 2025.04.11

TPepPro: a deep learning model for predicting peptide–protein interactions

Xiaohong Jin, Zimeng Chen, Dan Yu, Qianhui Jiang, Zhuobin Chen, Bin Yan, Jing Qin, Yong Liu, Junwen Wang 

Bioinformatics, Volume 41, Issue 1, January 2025, btae708, https://doi.org/10.1093/bioinformatics/btae708

Published:

25 November 2024

 Article history

Abstract

Motivation

Peptides and their derivatives hold potential as therapeutic agents. The rising interest in developing peptide drugs is evidenced by increasing approval rates by the FDA of USA. To identify the most potential peptides, study on peptide-protein interactions (PepPIs) presents a very important approach but poses considerable technical challenges. In experimental aspects, the transient nature of PepPIs and the high flexibility of peptides contribute to elevated costs and inefficiency. Traditional docking and molecular dynamics simulation methods require substantial computational resources, and the predictive accuracy of their results remain unsatisfactory.

Results

To address this gap, we proposed TPepPro, a Transformer-based model for PepPI prediction. We trained TPepPro on a dataset of 19,187 pairs of peptide-protein complexes with both sequential and structural features. TPepPro utilizes a strategy that combines local protein sequence feature extraction with global protein structure feature extraction. Moreover, TPepPro optimizes the architecture of structural featuring neural network in BN-ReLU arrangement, which notably reduced the amount of computing resources required for PepPIs prediction. According to comparison analysis, the accuracy reached 0.855 in TPepPro, achieving an 8.1% improvement compared to the second-best model TAGPPI. TPepPro achieved an AUC of 0.922, surpassing the second-best model TAGPPI with 0.844. Moreover, the newly developed TPepPro identify certain PepPIs that can be validated according to previous experimental evidence, thus indicating the efficiency of TPepPro to detect high potential PepPIs that would be helpful for amino acid drug applications.

Availability and implementation

The source code of TPepPro is available at https://github.com/wanglabhku/TPepPro.

TPepPro: Framework

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Journal Club 2025.03.21

Apigenin ameliorates inflamed ulcerative colitis by regulating mast cell degranulation via the PAMP-MRGPRX2 feedback loop

https://doi.org/10.1016/j.phymed.2025.156564

Yihan Huang a†, Na Wang b†, Xiaolan Ji a, Shiqiong Luo a, Ling Gong a, Chenrui Zhao a, Guodong Zheng a, Rui Liu a, Tao Zhang a

aSchool of Pharmacy, Health Science Center, Xi’an Jiaotong University, Xi’an 710061, China

bDepartment of Otolaryngology, Affiliated Hospital of North China University of Science and Technology, Tangshan 063000, China

Highlights

  • MrgprB2-mediated mast cell degranulation is critical for the persistence of inflammation in colitis.
  • PAMP-MrgprB2-induced pro-inflammatory positive feedback loop is critical for inflammation.
  • Apigenin reduces inflammatory symptoms and improves colon damage and inflammatory cell infiltration.
  • Apigenin inhibited degranulation of mast cell and carboxypeptidase A3 levels.
  • Apigenin ameliorating ulcerative colitis via MRGPRX2.

Keywords

Ulcerative colitis, Mast cells, Carboxypeptidase A3, Apigenin, MRGPRX2

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Journal Club 25-1-14

Processing of pain and itch information by modality-specific neurons within the anterior cingulate cortex in mice

Hyoung-Gon Ko 1,2 ,HyunsuJung 3,4,9, Seunghyo Han1,9, Dong Il Choi4,9,
Chiwoo Lee4,9, Ja Eun Choi4,JihaeOh4,ChuljungKwak3,DaeHeeHan3,
Jun-Nyeong Kim1,SanghyunYe 4,JiahLee4,JaehyunLee4,KyungminLee 5,
Jae-Hyung Lee 6,MinZhuo7,8 & Bong-Kiun Kaang3,

Pain and itch are aversive sensations with distinct qualities, processed in
overlapping pathways and brain regions, including the anterior cingulate
cortex (ACC), which is critical for their affective dimensions. However, the
cellular mechanisms underlying their processing in the ACC remain unclear.
Here, we identify modality-specific neuronal populations in layer II/III of the
ACC in mice involved in pain and itch processing. Using a synapse labeling
tool, we show that pain- and itch-related neurons selectively receive synaptic
inputs from mediodorsal thalamic neurons activated by pain and itch stimuli,
respectively. Chemogenetic inhibition of these neurons reduced pruriception
ornociception without affecting the opposite modality. Conversely, activation
of these neurons did not enhance stimulus-specific responses but commonly
increased freezing-like behavior. These findings reveal that the processing of
itch and pain information in the ACC involves activity-dependent and
modality-specific neuronal populations, and that functionally distinct ACC neuronal subsets process pain and itch

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Journal club 2025.03.07

Dual function of MrgprB2 receptor-dependent neural immune axis in chronic pain

Yucui Jiang a1 , Fan Ye d1 , Jian Zhang b1 , Yun Huang b , Yingxin Zong b , Feiyan Chen a , Yan Yang b , Chan Zhu b , Tao Yang c, Guang Yu b , Zongxiang Tang b

aSchool of Chinese Medicine, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing 210023, China
bSchool of Medicine, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing 210023, China
cState Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China
dCollege of Pharmacy, Jishou University, Jishou 416000, China

Received 26 March 2024, Revised 26 November 2024, Accepted 26 February 2025, Available online 28 February 2025.

Abstract

Introduction: Neuro-immune interactions have been recognized to be involved in the development of neuropathic pain induced by chemotherapeutic drugs (CINP). However, its role in pain resolution remains largely unknown, particularly concerning mast cells.

Objectives: To investigate the bidirectional modulation of mast cell Mas-related G protein-coupled receptor B2 (MrgprB2)-mediated neuro-immune interactions in CINP.

Methods: CINP model was established in wild-type mice, Mas-related G protein-coupled receptor D knockout (MrgprD-/-) mice, mast cell-deficient mice, MrgprB2 knockout (MrgprB2-/-) mice, and MrgprB2-Cre tdTomato mice. The role of MrgprB2 receptor in CINP was investigated by calcium imaging, cytokine antibody arrays, mining of single-cell sequencing databases, immunofluorescence, western blotting, co-immunoprecipitation (Co-IP), among other methodologies.

Results: We observed that cisplatin-induced allodynia was significantly inhibited in MrgprB2-/- mice, which was attributed to the blockade of tryptase release and the suppression of upregulation of protease-activated receptor 2 (PAR2) expression in dorsal root ganglion (DRG). Thus, the activation of MrgprB2/Tryptase/PAR2 axis contributed to the development of cisplatin-induced pain. In addition, we also found that there was co-expression of PAR2 and MrgprD in DRG neurons. And activation of PAR2 can negatively regulate the expression of MrgprD, whether in a physiological state or in a chronic pain condition. Consequently, MrgprD expression was down-regulated by the activation of the MrgprB2/Tryptase/PAR2 axis during the later stages of CINP, which was associated with pain relief. Therefore, the activation of MrgprB2/Tryptase/PAR2 axis also contributed to the alleviation of cisplatin-induced pain. This finding was in line with the phenomenon that persistent stimulation by cisplatin did not cause a continuous increase in pain.

Conclusions: Our research elucidated the bidirectional modulation of MrgprB2-dependent neural immune axis in CINP. This study emphasized that MrgprB2 is a critical target for early intervention in CINP, and highlighted the necessity of considering the mechanism differences at different stages in pain management.

Keywords: CINP; MrgprB2 receptor; MrgprD receptor; PAR2 receptor.

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Journal club 2025.02.28

Scratching promotes allergic inflammation and host defense via neurogenic mast cell activation

Andrew W. Liu1,2, Youran R. Zhang1,2, Chien-Sin Chen1,2, Tara N. Edwards1,2, Sumeyye Ozyaman1,2†,
Torben Ramcke1,2, Lindsay M. McKendrick1,2, Eric S. Weiss1,2, Jacob E. Gillis1,2, Colin R. Laughlin2‡,
Simran K. Randhawa2, Catherine M. Phelps2, Kazuo Kurihara1,2, Hannah M. Kang1,2,
Sydney-Lam N. Nguyen1,2, Jiwon Kim3, Tayler D. Sheahan3§, Sarah E. Ross3,4, Marlies Meisel2,5,
Tina L. Sumpter1,2, Daniel H. Kaplan1,2
*

1Department of Dermatology, University of Pittsburgh, Pittsburgh, PA, USA. 2Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA. 3Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA, USA. 4Pittsburgh Center for Pain Research, Pittsburgh, PA, USA. 5Cancer Immunology and Immunotherapy Program, UPMC Hillman Cancer Center, Pittsburgh, PA, USA.
*Corresponding author. Email: dankaplan@pitt.edu
†Present address: Department of Histology and Embryology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey.
‡Present address: Department of Immunobiology, Yale University, New Haven, CT, USA.
§Present address: Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.

Editor’s summary

Itch, the sensation that stimulates scratching behavior, is often triggered by skin irritants and inflammation. Liu et al. found that ablating itch-sensing neurons or physically preventing scratching decreased the inflammation associated with antigen-dependent mast cell responses in response to chemicals that induce allergic immune responses (see the Perspective by Ver Heul). Scratching promoted pain-sensing neurons to release a neuropeptide that stimulated mast cells, and this peptide hormone synergized with antigen-dependent activation to increase the mast cell’s degranulation and ability to produce inflammatory mediators. In a model of skin infection associated with antigen-specific mast cell responses, scratching contributed to decreasing the bacterial load. —Sarah H. Ross

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Journal club 2025.02.21

MrgprX2 regulates mast cell degranulation through PI3K/AKT and PLCγ signaling in pseudo-allergic reactions

https://doi.org/10.1016/j.intimp.2021.108389

Fan Zhang ab, Fang Hong ab, Lu Wang ac, Renjie Fu a, Jin Qi a, Boyang Yuab

aJiangsu Key Laboratory for TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 21198, China
bResearch Center for Traceability and Standardization of TCMs, China Pharmaceutical University, Nanjing 211198, China
cNanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, China

Received 10 August 2021, Revised 27 October 2021, Accepted 9 November 2021, Available online 15 December 2021, Version of Record 15 December 2021.

Highlights

  • •MrgprX2 is a key receptor for pseudo-allergic reactions.
  • •PI3K/AKT signaling pathway and PLCγ are important downstream of MrgprX2.
  • •Inhibiting PI3K/AKT signaling pathway and PLCγ remarkable weakened pseudo-allergic reactions both in vivo and in vitro.

Abstract

The G protein-coupled receptor MrgprX2 in mast cells is known to be a crucial receptor for pseudo-allergic reactions. MrgprX2 activation leads to elevated intracellular calcium levels and mast cell degranulation, but the underlying mechanism remains to be elucidated. Herein, we investigated the role of the phosphatidylinositol 3 kinase (PI3K)/serum-threonine kinase (AKT) signaling pathway and phospholipase C gamma (PLCγ) in mast cell degranulation mediated by MrgprX2 in LAD2 human-derived mast cells. The results showed that phosphorylated AKT (p-AKT) and PLCγ up-regulation were accompanied by an increase in intracellular calcium following activation of MrgprX2 by Compound 48/80, an inducer of mast cell degranulation. In contrast, p-AKT and PLCγ were down-regulated and intracellular calcium levels decreased after MrgprX2 knockdown. Mast cell degranulation was clearly suppressed; however, inhibiting PI3Kand PLCγ phosphorylation did not influence MrgprX2 expression. The increase in calcium concentration was suppressed and mast cell degranulation was weakened. Furthermore, by inhibiting PI3K and PLCγ phosphorylation in animals, the allergic symptoms caused by C48/80 were obviously reduced. We deduced that during the mast cell degranulation observed in pseudoallergic reactions, MrgprX2 regulated intracellular calcium levels via the PI3K/AKT and PLCγ pathways.

Keywords

Pseudo-allergic reactions, Mast cell, MRGPRX2, PI3K/AKT, PLCγ

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2025.02.14 Journal club

Clarithromycin-treated chronic spontaneous urticaria with the negative regulation of FcεRΙ and MRGPRX2 activation via CD300f

Delu Che 1Tao Zhang 2Tianxiao Zhang 3Yi Zheng 4Yajing Hou 2Songmei Geng 5Langchong He 6

Affiliations Expand

Abstract

Mast cells (MCs) are main effector cells in chronic spontaneous urticaria (CSU). Both Fc epsilon RI (FcεRΙ)- and MAS-related G coupled receptor-X2 (MRGPRX2)-mediated MC activations affect CSU course. Leukocyte mono-immunoglobulin-like receptor 3 (CD300f) has been shown to regulate FcεRΙ activation. However, no study has verified CD300f is a target to cure CSU. Therefore this study aimed to verify whether clarithromycin (CLA) regulates FcεRΙ- and MRGPRX2-mediated MC activations via CD300f and shows therapeutic effect on CSU. The target of CLA was verification. CLA inhibited FcεRΙ- and MRGPRX2-mediated MC activations were shown in vivo and in vitro. A single-center, self-comparison study was performed, and CLA-treated CSU was investigated in 28 patients who were not sensitive to the third-generation antihistamines. Serum inflammatory mediators in patients before and after CLA administration were analyzed. CLA effectively inhibited type Ι anaphylactic reactions and pseudo-allergic reactions in mice. Moreover, CLA inhibited FcεRΙ- and MRGPRX2-mediated MC signaling pathway activation. Regulatory effects of CLA were decreased significantly after CD300f knockdown. CLA effectively alleviated the symptoms of wheal and itch and reduced serum cytokine levels in patients. CLA negatively regulated FcεRΙ- and MRGPRX2-mediated MC activation via CD300f and showed significant therapeutic effect on CSU.

Keywords: Chronic spontaneous urticarial; Clarithromycin; Leukocyte mono-immunoglobulin-like receptor 3; Mast cell; Negatively regulation.

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2025.02.07 Journal club

Mast cell activation induced by tamoxifen citrate via MRGPRX2 plays a potential adverse role in breast cancer treatment

Biochemical Pharmacology
journal homepage: www.elsevier.com/locate/biochempharm

Jiapan Gao a,b,1, Xinyue Su a,b,1, Yuxiu Zhang a,b, Xiaoyu Ma a,b, Bingxi Ren a,b, Panpan Lei a,b, Jiming Jin c, Weina Ma a,b,*

a School of Pharmacy, Xi’an Jiaotong University, Xi’an 710061, PR China
b State Key Laboratory of Shaanxi for Natural Medicines Research and Engineering, Xi’an 710061, PR China
c First School of Clinical Medicine, Shaanxi University of Chinese Medicine, Xi’an 712046, PR China

ABSTRACT
Breast cancer is the most common malignant tumor endangering women’s life and health. Tamoxifen citrate (TAM) is the first-line drug of adjuvant endocrine therapy for estrogen receptor-positive (ER+) breast cancer patients. Some sporadic cases have described rare adverse reactions of TAM with potentially life-threatening dermatological manifestations, which were associated with skin allergy. Mas related G protein-coupled recep- tor X2 (MRGPRX2) on human mast cells is the key target for skin allergy. We aimed to investigate the mechanism of TAM-induced allergic reactions and their potential effects on TAM treatment for breast cancer. In our study, TAM can specifically bind with MRGPRX2, which was mainly driven by hydrophobic force. TAM formed hydrogen bonds with TRP243, TRP248, and GLU164 residues in MRGPRX2. TAM induced calcium mobilization and degranulation of mast cells via MRGPRX2. Besides, TAM induced passive cutaneous anaphylaxis and active systemic anaphylaxis in C57BL/6 mice. The release of β-hexosaminidase, histamine, tumor necrosis factor-α, monocyte chemoattractant protein 1, and interleukin-8 were increased by TAM in vitro and in vivo. Furthermore, we found that MCF-7 and T-47D breast cancer cells can recruit mast cells to adjacent cancerous tissues. Besides, mast cell activation induced by TAM via MRGPRX2 significantly promoted the proliferation and migration of MCF-7 and T-47D cells, which can be effectively reversed by mast cell membrane stabilizer clarithromycin and MRGPRX2 silencing. This study proposed an anti-allergic therapeutic strategy for breast cancer treatment with TAM, while also the potential of MRGPRX2 as an adjunctive target.

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