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1.
Cells ; 13(3)2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38334612

RESUMO

Mast cells (MCs) are an important part of the immune system, responding both to pathogens and toxins, but they also play an important role in allergic diseases, where recent data show that non-IgE-mediated activation is also of relevance, especially in chronic urticaria (CU) and atopic dermatitis (AD). Skin MCs express Mas-related G-protein-coupled receptor X2 (MRGPRX2), a key protein in non-IgE-dependent MC degranulation, and its overactivity is one of the triggering factors for the above-mentioned diseases, making MRGPRX2 a potential therapeutic target. Reviewing the latest literature revealed our need to focus on the discovery of MRGPRX2 activators as well as the ongoing vast research towards finding specific MRGPRX2 inhibitors for potential therapeutic approaches. Most of these studies are in their preliminary stages, with one drug currently being investigated in a clinical trial. Future studies and improved model systems are needed to verify whether any of these inhibitors may have the potential to be the next therapeutic treatment for CU, AD, and other pseudo-allergic reactions.


Assuntos
Urticária Crônica , Dermatite Atópica , Hipersensibilidade , Humanos , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/metabolismo , Hipersensibilidade/metabolismo , Mastócitos/metabolismo , Urticária Crônica/tratamento farmacológico , Receptores Acoplados a Proteínas G/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Neuropeptídeos/metabolismo
2.
Neuropeptides ; 104: 102417, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38422597

RESUMO

RF-amide peptides influence multiple physiological processes, including the regulation of appetite, stress responses, behavior, and reproductive and endocrine functions. In this study, we examined the roles of neuropeptide FF receptors (NPFFR1 and NPFFR2) by generating several lipidized analogs of neuropeptide AF (NPAF) and 1DMe, a stable analog of neuropeptide FF (NPFF). These analogs were administered peripherally for the first time to investigate their effects on food intake and other potential physiological outcomes. Lipidized NPAF and 1DMe analogs exhibited enhanced stability and increased pharmacokinetics. These analogs demonstrated preserved high affinity for NPFFR2 in the nanomolar range, while the binding affinity for NPFFR1 was tens of nanomoles. They activated the ERK and Akt signaling pathways in cells overexpressing the NPFFR1 and NPFFR2 receptors. Acute food intake in fasted mice decreased after the peripheral administration of oct-NPAF or oct-1DMe. However, this effect was not as pronounced as that observed after the injection of palm11-PrRP31, a potent anorexigenic compound used as a comparator that binds to GPR10 and the NPFFR2 receptor with high affinity. Neither oct-1DMe nor oct-NPAF decreased food intake or body weight in mice with diet-induced obesity during long-term treatment. In mice treated with oct-1DMe, we observed decreased activity in the central zone during the open field test and decreased activity in the open arms of the elevated plus maze. Furthermore, we observed a decrease in plasma noradrenaline levels and an increase in plasma corticosterone levels, as well as an increase in Crh expression in the hypothalamus. Moreover, neuronal activity in the hypothalamus was increased after treatment with oct-1DMe. In this study, we report that oct-1DMe did not have any long-term effects on the central regulation of food intake; however, it caused anxiety-like behavior.


Assuntos
Regulação do Apetite , Oligopeptídeos , Camundongos , Animais , Oligopeptídeos/farmacologia , Receptores de Neuropeptídeos/metabolismo , Ansiedade
3.
Gene ; 907: 148283, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38354915

RESUMO

BACKGROUND: Isolated growth hormone deficiency (IGHD) is a rare genetically heterogeneous disorder caused primarily by mutations in GH1 and GH releasing hormone receptor (GHRHR). The aim of this study was to identify the molecular etiology of a Chinese boy with IGHD. METHODS: Whole-exome sequencing, sanger sequencing and bioinformatic analysis were performed to screen for candidate mutations. The impacts of candidate mutation on gene expression, intracellular localization and protein function were further evaluated by in vitro assays. RESULTS: A novel heterozygous frameshift mutation in the GHRH gene (c.91dupC, p.R31Pfs*98) was identified in a Chinese boy clinically diagnosed as having IGHD. The mutation was absent in multiple public databases, and considered as deleterious using in silico prediction, conservative analysis and three-dimensional homology modeling. Furthermore, mRNA and protein expression levels of mutant GHRH were significantly increased than wild-type GHRH (p < 0.05). Moreover, mutant GHRH showed an aberrant accumulation within the cytoplasm, and obviously reduced ability to stimulate GH secretion and cAMP accumulation in human GHRHR-expressing pituitary GH3 cells compared to wild-type GHRH (p < 0.05). CONCLUSION: Our study discovered the first loss-of function mutation of GHRH in a Chinese boy with IGHD and provided new insights on IGHD pathogenesis caused by GHRH haploinsufficiency.


Assuntos
Nanismo Hipofisário , Hormônio do Crescimento Humano , Masculino , Humanos , Mutação da Fase de Leitura , Nanismo Hipofisário/genética , Hormônio do Crescimento Humano/genética , Receptores de Neuropeptídeos/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Mutação , China , Hormônio do Crescimento
4.
Eur J Pharmacol ; 969: 176457, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38395375

RESUMO

Neuropeptide FF (NPFF) plays a critical role in various physiological processes through the activation of neuropeptide FF receptor 1 and 2 (NPFFR1 and NPFFR2). Numerous evidence has indicated that NPFF exhibits opposite opioid-modulating effects on opioid-induced analgesia after supraspinal and spinal administrations, while the detailed role of NPFFR1 and NPFFR2 remains unclear. In this study, we employed pharmacological and genetic inhibition of NPFFR to investigate the modulating roles of central NPFFR1 and NPFFR2 in opioid-induced analgesia and hyperalgesia, using a male mouse model of acute fentanyl-induced analgesia and secondary hyperalgesia. Our findings revealed that intrathecal (i.t.) injection of the nonselective NPFFR antagonist RF9 significantly enhanced fentanyl-induced analgesia, whereas intracerebroventricular (i.c.v.) injection did not show the same effect. Moreover, NPFFR2 deficient (npffr2-/-) mice exhibited stronger analgesic responses to fentanyl compared to wild type (WT) or NPFFR1 knockout (npffr1-/-) mice. Intrathecal injection of RF9 in npffr1-/- mice also significantly enhanced fentanyl-induced analgesia. These results indicate a crucial role of spinal NPFFR2 in the enhancement of opioid analgesia. Contrastingly, hyperalgesia induced by fentanyl was markedly reversed in npffr1-/- mice but remained unaffected in npffr2-/- mice. Similarly, i.c.v. injection of the selective NPFFR1 antagonist RF3286 effectively prevented fentanyl-induced hyperalgesia in WT or npffr2-/- mice. Notably, co-administration of i.c.v. RF3286 and i.t. RF9 augmented fentanyl-induced analgesia while reducing hyperalgesia. Collectively, these findings highlight the modulating effects of blocking spinal NPFFR2 and supraspinal NPFFR1 on fentanyl-induced analgesia and hyperalgesia, respectively, which shed a light on understanding the pharmacological function of NPFF system in future studies.


Assuntos
Analgesia , Hiperalgesia , Camundongos , Masculino , Animais , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Fentanila/farmacologia , Analgésicos Opioides/farmacologia , Dor , Receptores de Neuropeptídeos/genética
5.
Skin Res Technol ; 30(2): e13588, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38284237

RESUMO

BACKGROUND: Prurigo nodularis (PN) is a chronic inflammatory skin disorder that is characterized by extremely itchy nodules. Proadrenomedullin N-terminal 20 (PAMP) activates mast cell degranulation via Mas-related G protein-coupled receptor X2 (MRGPRX2), which is associated with pruritus in allergic contact dermatitis. However, the mechanisms underlying the action of PAMP and MRGPRX2 in PN remain unclear. OBJECTIVE: To determine the role of PAMP-induced mast cell activation via MRGPRX2 (mouse homologous Mrgprb2) in PN. METHODS: The expression of PAMP and the number of MRGPRX2-expressing mast cells in the skin biopsies of patients with PN, atopic dermatitis (AD), and healthy participants were analyzed using immunohistochemistry and immunofluorescence, respectively. The biphasic response of PAMP9-20 mediated by Mrgprb2 in mouse peritoneal mast cells (PMC) was validated in vitro using qRT-PCR, ELISA, flow cytometry, and siRNA techniques. RESULTS: PAMP expression and the number of MRGPRX2+ mast cells in lesional PN skin, but not in AD, were elevated compared to healthy skin. PAMP9-20 mediates the immediate and delayed phase responses of PMC, such as degranulation, histamine and ß-hexosaminidase release, and secretion of inflammatory factors such as CCL2, TNF-α, and GM-CSF. These effects were inhibited when Mrgprb2 expression was silenced. Silencing Mrgprb2 did not affect the biphasic response of PMC that was induced by IgE-FcεRI activation. CONCLUSIONS: The results show that PAMP mediates mouse mast cell activation via Mrgprb2, which may be involved in the pathogenesis of PN. The PAMP/ Mrgprb2 pathway, independent of classical IgE signaling, could be developed as a candidate drug target for treating PN.


Assuntos
Dermatite Atópica , Prurigo , Receptores Acoplados a Proteínas G , Animais , Humanos , Camundongos , Adrenomedulina/metabolismo , Dermatite Atópica/patologia , Imunoglobulina E/metabolismo , Mastócitos/metabolismo , Mastócitos/patologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Prurigo/metabolismo , Prurigo/patologia , Prurido , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo , Pele/metabolismo
6.
J Neurosci Res ; 102(1): e25271, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38284837

RESUMO

Similar to the human brain, Drosophila glia may well be divided into several subtypes that each carries out specific functions. Glial GPCRs play key roles in crosstalk between neurons and glia. Drosophila Lgr4 (dLgr4) is a human relaxin receptor homolog involved in angiogenesis, cardiovascular regulation, collagen remodeling, and wound healing. A recent study suggests that ilp7 might be the ligand for Lgr4 and regulates escape behavior of Drosophila larvae. Here we demonstrate that Drosophila Lgr4 expression in glial cells, not neurons, is necessary for early development, adult behavior, and lifespan. Reducing the Lgr4 level in glial cells disrupts Drosophila development, while knocking down other LGR family members in glia has no impact. Adult-specific knockdown of Lgr4 in glia but not neurons reduce locomotion, male reproductive success, and animal longevity. The investigation of how glial expression of Lgr4 contributes to this behavioral alteration will increase our understanding of how insulin signaling via glia selectively modulates neuronal activity and behavior.


Assuntos
Proteínas de Drosophila , Drosophila , Neuroglia , Receptores Acoplados a Proteínas G , Animais , Masculino , Encéfalo , Neurônios , Receptores de Neuropeptídeos , Receptores Acoplados a Proteínas G/genética , Proteínas de Drosophila/genética
7.
Commun Biol ; 7(1): 52, 2024 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184723

RESUMO

Patients with idiopathic pulmonary fibrosis show a strongly upregulated expression of chemokine CXCL14, whose target is still unknown. Screening of CXCL14 in a panel of human G protein-coupled receptors (GPCRs) revealed its potent and selective activation of the orphan MAS-related GPCR X2 (MRGPRX2). This receptor is expressed on mast cells and - like CXCL14 - upregulated in bronchial inflammation. CXCL14 induces robust activation of MRGPRX2 and its putative mouse ortholog MRGPRB2 in G protein-dependent and ß-arrestin recruitment assays that is blocked by a selective MRGPRX2/B2 antagonist. Truncation combined with mutagenesis and computational studies identified the pharmacophoric sequence of CXCL14 and its presumed interaction with the receptor. Intriguingly, C-terminal domain sequences of CXCL14 consisting of 4 to 11 amino acids display similar or increased potency and efficacy compared to the full CXCL14 sequence (77 amino acids). These results provide a rational basis for the future development of potential idiopathic pulmonary fibrosis therapies.


Assuntos
Quimiocinas , Fibrose Pulmonar Idiopática , Animais , Humanos , Camundongos , Aminoácidos , Bioensaio , Quimiocinas CXC , Fibrose Pulmonar Idiopática/genética , Proteínas do Tecido Nervoso/genética , Receptores Acoplados a Proteínas G/genética , Receptores de Neuropeptídeos
8.
Peptides ; 174: 171164, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38272240

RESUMO

Neuropeptide FF (NPFF) is an octapeptide that regulates various cellular processes, especially pain perception. Recently, there has been a growing interest in understanding the modulation of NPFF in neuroendocrine inflammation. This review aims to provide a thorough overview of the regulation of NPFF in macrophage-mediated biological processes. We delve into the impact of NPFF on macrophage polarization, self-renewal modulation, and the promotion of mitophagy, facilitating the transition from thermogenic fat to fat-storing adipose tissue. Additionally, we explore the NPFF-dependent regulation of the inflammatory response mediated by macrophages, its impact on the differentiation of macrophages, and its capacity to induce alterations in the transcriptome of macrophages. We also address the potential of NPFF as a therapeutic molecule in the field of neuroendocrine inflammation. Overall, our work offers an understanding of the influence of NPFF on macrophage, facilitating the exploration of its pharmacological significance in future studies.


Assuntos
Oligopeptídeos , Receptores de Neuropeptídeos , Humanos , Oligopeptídeos/farmacologia , Macrófagos , Inflamação
9.
Nat Commun ; 15(1): 113, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38168103

RESUMO

Mast cells are phenotypically and functionally heterogeneous, and their state is possibly controlled by local microenvironment. Therefore, specific analyses are needed to understand whether mast cells function as powerful participants or dispensable bystanders in specific diseases. Here, we show that degranulation of mast cells in inflammatory synovial tissues of patients with rheumatoid arthritis (RA) is induced via MAS-related G protein-coupled receptor X2 (MRGPRX2), and the expression of MHC class II and costimulatory molecules on mast cells are upregulated. Collagen-induced arthritis mice treated with a combination of anti-IL-17A and cromolyn sodium, a mast cell membrane stabilizer, show significantly reduced clinical severity and decreased bone erosion. The findings of the present study suggest that synovial microenvironment-influenced mast cells contribute to disease progression and may provide a further mast cell-targeting therapy for RA.


Assuntos
Artrite Reumatoide , Sinoviócitos , Humanos , Camundongos , Animais , Mastócitos/metabolismo , Artrite Reumatoide/metabolismo , Sinoviócitos/metabolismo , Membrana Sinovial/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Neuropeptídeos/metabolismo
10.
J Control Release ; 367: 158-166, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38253205

RESUMO

Mast cells (MCs) are primary effector cells involved in immediate allergic reactions. Mas-related G protein-coupled receptor-X2 (MrgX2), which is highly expressed on MCs, is involved in receptor-mediated drug-induced pseudo-anaphylaxis. Many small-molecule drugs and peptides activate MrgX2, resulting in MC activation and allergic reactions. Although small-molecule drugs can be identified using existing MrgX2 ligand-screening systems, there is still a lack of effective means to screen peptide ligands. In this study, to screen for peptide drugs, the MrgX2 high-affinity endogenous peptide ligand substance P (SP) was used as a recognition group to design a fluorescent peptide probe. Spectroscopic properties and fluorescence imaging of the probe were assessed. The probe was then used to screen for MrgX2 agonists among peptide antibiotics. In addition, the effects of peptide antibiotics on MrgX2 activation were investigated in vivo and in vitro. The environment-sensitive property of the probe was revealed by the dramatic increase in fluorescence intensity after binding to the hydrophobic ligand-binding domain of MrgX2. Based on these characteristics, it can be used for in situ selective visualization of MrgX2 in live cells. The probe was used to screen ten types of peptide antibiotics, and we found that caspofungin and bacitracin could compete with the probe and are hence potential ligands of MrgX2. Pharmacological experiments confirmed this hypothesis; caspofungin and bacitracin activated MCs via MrgX2 in vitro and induced local anaphylaxis in mice. Our research can be expected to provide new ideas for screening MrgX2 peptide ligands and reveal the mechanisms of adverse reactions caused by peptide drugs, thereby laying the foundation for improving their clinical safety.


Assuntos
Anafilaxia , Hipersensibilidade a Drogas , Camundongos , Animais , Receptores de Neuropeptídeos/agonistas , Receptores de Neuropeptídeos/metabolismo , Ligantes , Bacitracina/metabolismo , Bacitracina/farmacologia , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/metabolismo , Caspofungina/metabolismo , Caspofungina/farmacologia , Peptídeos/farmacologia , Antibacterianos/farmacologia , Mastócitos/metabolismo , Degranulação Celular/fisiologia
11.
Cells ; 13(1)2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38201297

RESUMO

MRGPRX2, the human member of the MAS-related G-protein-coupled receptors (GPCRs), mediates the immunoglobulin E (IgE)-independent responses of a subset of mast cells (MCs) that are associated with itch, pain, neurogenic inflammation, and pseudoallergy to drugs. The mechanisms underlying the responses of MRGPRX2 to its multiple and diverse ligands are still not completely understood. Given the close association between GPCR location and function, and the key role played by Rab GTPases in controlling discrete steps along vesicular trafficking, we aimed to reveal the vesicular pathways that directly impact MRGPRX2-mediated exocytosis by identifying the Rabs that influence this process. For this purpose, we screened 43 Rabs for their functional and phenotypic impacts on MC degranulation in response to the synthetic MRGPRX2 ligand compound 48/80 (c48/80), which is often used as the gold standard of MRGPRX2 ligands, or to substance P (SP), an important trigger of neuroinflammatory MC responses. Results of this study highlight the important roles played by macropinocytosis and autophagy in controlling MRGPRX2-mediated exocytosis, demonstrating a close feedback control between the internalization and post-endocytic trafficking of MRGPRX2 and its triggered exocytosis.


Assuntos
Secreções Corporais , Exocitose , Humanos , Autofagia , Imunoglobulina E , Inflamação , Vesículas Secretórias , Proteínas do Tecido Nervoso , Receptores de Neuropeptídeos , Receptores Acoplados a Proteínas G
12.
Immunity ; 57(2): 333-348.e6, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38295799

RESUMO

The notion that neutrophils exist as a homogeneous population is being replaced with the knowledge that neutrophils adopt different functional states. Neutrophils can have a pro-inflammatory phenotype or an anti-inflammatory state, but how these states are regulated remains unclear. Here, we demonstrated that the neutrophil-expressed G-protein-coupled receptor (GPCR) Mrgpra1 is a negative regulator of neutrophil bactericidal functions. Mrgpra1-mediated signaling was driven by its ligand, neuropeptide FF (NPFF), which dictated the balance between pro- and anti-inflammatory programming. Specifically, the Mrgpra1-NPFF axis counter-regulated interferon (IFN) γ-mediated neutrophil polarization during acute lung infection by favoring an alternative-like polarization, suggesting that it may act to balance overzealous neutrophilic responses. Distinct, cross-regulated populations of neutrophils were the primary source of NPFF and IFNγ during infection. As a subset of neutrophils at steady state expressed NPFF, these findings could have broad implications in various infectious and inflammatory diseases. Therefore, a neutrophil-intrinsic pathway determines their cellular fate, function, and magnitude of infection.


Assuntos
Infecções Bacterianas , Neuropeptídeos , Humanos , Receptores de Neuropeptídeos/metabolismo , Neutrófilos/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Anti-Inflamatórios
13.
Immunol Lett ; 265: 1-4, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38042500

RESUMO

There is growing evidence suggesting that in a subset of patients with severe chronic urticaria [CSU] mast cells are activated via mechanisms that bypass the high affinity IgE receptor. This might explain why some patients do not respond at all to anti-IgE therapy [omalizumab]. The present article reviews the pathogenic mechanisms able to lead to histamine release from mast cells described so far in patients with CSU. These include the activation of the coagulation cascade, the activation of the complement system, the activation of the MRGPRX2 receptor, and the platelet activating factor vicious circle. The article suggests some possible interpretations for the clinical events occurring in this specific subset of patients.


Assuntos
Urticária Crônica , Urticária , Humanos , Receptores de IgE , Imunoglobulina E , Urticária/tratamento farmacológico , Urticária/patologia , Mastócitos/fisiologia , Liberação de Histamina , Autoanticorpos , Doença Crônica , Proteínas do Tecido Nervoso , Receptores de Neuropeptídeos , Receptores Acoplados a Proteínas G
14.
Allergy ; 79(3): 601-612, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37947156

RESUMO

Immediate drug hypersensitivity reactions (IDHRs) are a burden for patients and the health systems. This problem increases when taking into account that only a small proportion of patients initially labelled as allergic are finally confirmed after an allergological workup. The diverse nature of drugs involved will imply different interactions with the immunological system. Therefore, IDHRs can be produced by a wide array of mechanisms mediated by the drug interaction with specific antibodies or directly on effector target cells. These heterogeneous mechanisms imply an enhanced complexity for an accurate diagnosis and the identification of the phenotype and endotype at early stages of the reaction is of vital importance. Currently, several endophenotypic categories (type I IgE/non-IgE, cytokine release, Mast-related G-protein coupled receptor X2 (MRGPRX2) or Cyclooxygenase-1 (COX-1) inhibition and their associated biomarkers have been proposed. A precise knowledge of endotypes will permit to discriminate patients within the same phenotype, which is crucial in order to personalise diagnosis, future treatment and prevention to improve the patient's quality of life.


Assuntos
Hipersensibilidade a Drogas , Hipersensibilidade Imediata , Hipersensibilidade , Humanos , Qualidade de Vida , Hipersensibilidade a Drogas/diagnóstico , Hipersensibilidade Imediata/diagnóstico , Biomarcadores , Receptores Acoplados a Proteínas G/genética , Mastócitos , Degranulação Celular , Proteínas do Tecido Nervoso , Receptores de Neuropeptídeos
15.
J Invest Dermatol ; 144(1): 53-62.e2, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37482287

RESUMO

Atopic dermatitis (AD) is a common chronic inflammatory skin disease characterized by T helper 2 inflammation as the core pathogenic mechanism. MRGPRX2 plays a key role in nonhistamine allergies and neuroimmune mechanisms in chronic inflammatory dermatitis. However, the role of MRGPRX2 in AD and the development of type 2 inflammation is not yet clear. This study aimed to define the role of MRGPRX2 in type 2 inflammation development and cytokine release in AD by determining its levels in patients with AD and healthy controls. Furthermore, MrgprB2-conditional knockout (MrgprB2-/-) and wild-type mice were used to construct an MC903-induced AD mouse model to observe skin inflammation and cytokine release. Tryptase and its antagonist were applied separately to MrgprB2-/- mice with AD and wild-type mice with AD to confirm the role of the MRGPRB2-tryptase axis in the development of type 2 inflammation in AD. We found that AD severity and type 2 cytokine levels were not associated with IgE levels but were associated with MRGPRX2/MRGPRB2 expression. MrgprB2-/- mice with AD showed milder phenotypes and inflammatory infiltration in the skin than wild-type mice with AD. Tryptase released by MRGPRX2/MRGPRB2 activation is involved in the release of type 2 cytokines, which contributes to inflammatory development in AD.


Assuntos
Dermatite Atópica , Animais , Humanos , Camundongos , Citocinas/metabolismo , Dermatite Atópica/patologia , Inflamação/patologia , Mastócitos , Proteínas do Tecido Nervoso/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Triptases/metabolismo
17.
Steroids ; 202: 109349, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38072091

RESUMO

RFRP-3 is a functional ortholog of avian GnIH and regulates reproductive activities in the gonads of animals. However, the role of RFRP-3 in the function of ovarian granulosa cells in mice remains unclear. First, we detected the expression of the RFRP-3 receptor (GPR147) in the ovarian granulosa cells of mice. Second, the effect of RFRP-3 treatment on estradiol and progesterone secretions from granulosa cells was tested by ELISA. Meanwhile, the expression of genes and proteins regulating steroid hormone synthesis was respectively examined by qPCR and western blot. Furthermore, the effect of RFRP-3 treatment on the apoptosis of granulosa cells was analyzed. The results revealed that the GPR147 protein (a RFRP-3 receptor) was expressed in the ovarian granulosa cells of mice. Low and medium doses RFRP-3 treatment significantly reduced progesterone secretion in the granulosa cells (P < 0.05), while RFRP-3 suppressed p450scc, 3ß-HSD, StAR, and FSHR expression in a non-dose-dependent manner. Moreover, RFRP-3 treatment might induce the apoptosis of granulosa cells. Additionally, low doses RFRP-3 significantly reduced p-ERK1/2 protein expression (P < 0.05) in the ovarian granulosa cells. We here, for the first time, confirmed that GPR147 was expressed in the ovarian granulosa cells of mice. Our findings suggested that and RFRP-3 regulates the granulosa cell function through the ERK signaling pathway, which will lay the foundation for uncovering molecular mechanisms by which RFRP-3 regulates follicle development in future.


Assuntos
Neuropeptídeos , Progesterona , Receptores de Neuropeptídeos , Feminino , Camundongos , Animais , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo , Progesterona/farmacologia , Células da Granulosa , Apoptose
18.
Cells ; 12(23)2023 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-38067128

RESUMO

Skin mast cells (MCs) express high levels of MRGPRX2, FcεRI, and ST2, and vigorously respond to their ligands when triggered individually. IL-33/ST2 also potently synergizes with other receptors, but the molecular underpinnings are poorly understood. Human skin-derived MCs were stimulated via different receptors individually or jointly in the presence/absence of selective inhibitors. TNF was quantified by ELISA. Signaling cascades were studied by immunoblot. TNF was stimulated by FcεRI ≈ ST2 > MRGPRX2. Surprisingly, neither FcεRI nor MRGPRX2 stimulation elicited NF-κB activation (IκB degradation, p65 phosphorylation) in stark contrast to IL-33. Accordingly, TNF production did not depend on NF-κB in FcεRI- or MRGPRX2-stimulated MCs, but did well so downstream of ST2. Conversely, ERK1/2 and PI3K were the crucial modules upon FcεRI/MRGPRX2 stimulation, while p38 was key to the IL-33-elicited route. The different signaling prerequisites were mirrored by their activation patterns with potent pERK/pAKT after FcεRI/MRGPRX2, but preferential induction of pp38/NF-κB downstream of ST2. FcεRI/MRGPRX2 strongly synergized with IL-33, and some synergy was still observed upon inhibition of each module (ERK1/2, JNK, p38, PI3K, NF-κB). IL-33's contribution to synergism was owed to p38 > JNK > NF-κB, while the partner receptor contributed through ERK > PI3K ≈ JNK. Concurrent IL-33 led to slightly prolonged pERK (downstream of MRGPRX2) or pAKT (activated by FcεRI), while the IL-33-elicited modules (pp38/NF-κB) remained unaffected by co-stimulation of FcεRI/MRGPRX2. Collectively, the strong synergistic activity of IL-33 primarily results from the complementation of highly distinct modules following co-activation of the partner receptor rather than by altered signal strength of the same modules.


Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1 , NF-kappa B , Humanos , NF-kappa B/metabolismo , Interleucina-33 , Transdução de Sinais , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Neuropeptídeos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
19.
J Med Chem ; 66(24): 17138-17154, 2023 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-38095323

RESUMO

Our previous study reported the multifunctional agonist for opioid and neuropeptide FF receptors DN-9, along with its cyclic peptide analogues c[D-Cys2, Cys5]-DN-9 and c[D-Lys2, Asp5]-DN-9. These analogues demonstrated potent antinociceptive effects with reduced opioid-related side effects. To develop more stable and effective analgesics, we designed, synthesized, and evaluated seven hydrocarbon-stapled cyclic peptides based on DN-9. In vitro calcium mobilization assays revealed that most of the stapled peptides, except 3, displayed multifunctional agonistic activities at opioid and neuropeptide FF receptors. Subcutaneous administration of all stapled peptides resulted in effective and long-lasting antinociceptive activities lasting up to 360 min. Among these stapled peptides, 1a and 1b emerged as the optimized compounds, producing potent central antinociception following subcutaneous, intracerebroventricular, and oral administrations. Additionally, subcutaneous administration of 1a and 1b caused nontolerance antinociception, with limited occurrence of constipation and addiction. Furthermore, 1a was selected as the final optimized compound due to its wider safety window compared to 1b.


Assuntos
Analgésicos Opioides , Oligopeptídeos , Analgésicos Opioides/efeitos adversos , Oligopeptídeos/química , Analgésicos/química , Peptídeos/química , Receptores de Neuropeptídeos/agonistas , Encéfalo , Receptores Opioides mu/agonistas
20.
J Dermatol Sci ; 112(3): 128-137, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37953179

RESUMO

BACKGROUND: Topical tacrolimus, although widely used in the treatment of dermatoses, presents with an immediate irritation on initial application resembling a pseudo-allergic reaction. Mas-related G protein-coupled receptor X2 (MRGPRX2) in mast cells (MCs) mediates drug-induced pseudo-allergic reaction and immunoglobulin E (IgE)-independent pruritis in chronic skin diseases. However, the immunosuppression mechanism of tacrolimus on MCs via MRGPRX2 has not been reported. OBJECTIVE: To investigate the role of MRGPRX2 and the mechanism of action of tacrolimus on its short-term and long-term applications. METHODS: Wild-type mice, KitW-sh/W-sh mice, and MrgprB2-deficient (MUT) mice were used to study the effect of tacrolimus on in vivo anaphylaxis model. LAD2 cells and MRGPRX2-knockdown LAD2 cells were specifically used to derive the associated mechanism of the tacrolimus effect. RESULTS: Short-term application of tacrolimus triggers IgE-independent activation of MCs via MRGPRX2/B2 in both in vivo and in vitro experiments. Tacrolimus binds to MRGPRX2, which was verified by fluorescently labeled tacrolimus in cells. On long-term treatment with tacrolimus, the initial allergic reaction fades away corresponding with the downregulation of MRGPRX2, which leads to decreased release of inflammatory cytokines (P < 0.05 to P < 0.001). CONCLUSION: Short-term treatment with tacrolimus induces pseudo-allergic reaction via MRGPRX2/B2 in MCs, whereas long-term treatment downregulates expression of MRGPRX2/B2, which may contribute to its potent immunosuppressive effect in the treatment of various skin diseases.


Assuntos
Anafilaxia , Hipersensibilidade Tardia , Dermatopatias , Animais , Camundongos , Tacrolimo/efeitos adversos , Mastócitos , Anafilaxia/induzido quimicamente , Anafilaxia/metabolismo , Inflamação/metabolismo , Imunoglobulina E , Receptores Acoplados a Proteínas G/metabolismo , Dermatopatias/metabolismo , Receptores de Neuropeptídeos/metabolismo , Degranulação Celular
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