RESUMEN
Systemic lupus erythematosus is a complex autoimmune disease during which patients develop autoantibodies raised against nuclear antigens. During the course of the disease, by accumulating in secondary lymphoid organs (SLOs), basophils support autoreactive plasma cells to amplify autoantibody production. We have recently shown that murine lupus-like disease could be controlled by 10 days of oral treatment with a combination of prostaglandin D2 (PGD2) receptor (PTGDR) antagonists through the inhibition of basophil activation and recruitment to SLOs. Importantly, inhibiting solely PTGDR-1 or PTGDR-2 was ineffective, and the development of lupus-like disease could only be dampened by using antagonists for both PTGDR-1 and PTGDR-2. Here, we aimed at establishing a proof of concept that a clinically relevant bispecific antagonist of PTGDR-1 and PTGDR-2 could be efficient to treat murine lupus-like nephritis. Diseased Lyn-deficient female mice received treatment with AMG853 (vidupiprant, a bispecific PTGDR-1/PTGDR-2 antagonist) for 10 days. This led to the dampening of basophil activation and recruitment in SLOs and was associated with a decrease in plasmablast expansion and immunoglobulin E (IgE) production. Ten days of treatment with AMG853 was consequently sufficient in reducing the dsDNA-specific IgG titers, circulating immune complex glomerular deposition, and renal inflammation, which are hallmarks of lupus-like disease. Thus, bispecific PTGDR-1 and PTGDR-2 antagonists, such as AMG853, are a promising class of drugs for the treatment or prevention of organ damage in systemic lupus erythematosus.
Asunto(s)
Lupus Eritematoso Sistémico , Nefritis Lúpica , Animales , Autoanticuerpos , Basófilos , Femenino , Humanos , Nefritis Lúpica/tratamiento farmacológico , Masculino , Ratones , ProstaglandinasRESUMEN
BACKGROUND: Precision medicine is a promising strategy to identify biomarkers, stratify asthmatic patients according to different endotypes, and match them with the appropriate therapy. This proof-of-concept study aimed to investigate whether gene expression in peripheral blood could provide a valuable noninvasive approach for the molecular phenotyping of asthma. METHODS: We performed whole-transcriptome RNA sequencing on peripheral blood of 30 non-atopic non-asthmatic controls and 30 asthmatic patients. A quantitative PCR (qPCR) validation study of PTGDR2 that encodes for CRTH2 receptor, expressed in cells involved in T2 inflammation, was developed in a cohort of 361 independent subjects: 94 non-asthmatic non-atopic controls, 187 asthmatic patients [including 82 with chronic rhinosinusitis with nasal polyposis (CRSwNP) and 24 with aspirin-exacerbated respiratory disease (AERD)], 52 with allergic rhinitis, and 28 with CRSwNP without asthma. RESULTS: PTGDR2 was one of the most differentially overexpressed genes in asthmatic patients' peripheral blood (p-value 2.64 × 106). These results were confirmed by qPCR in the validation study, where PTGDR2 transcripts were significantly upregulated in asthmatic patients (p < 0.001). This upregulation was mainly detected in some subgroups such as allergic asthma, asthma with CRSwNP, AERD, eosinophilic asthma, and severe persistent asthma. PTGDR2 expression was detected in different blood cell types, and its correlation with eosinophil counts showed differences in some groups of asthmatic patients. CONCLUSIONS: We found that PTGDR2 expression levels could identify asthma patients, introduce a minimally invasive biomarker for adult asthma molecular phenotyping, and add additional information to blood eosinophils. Although further studies are required, analyzing PTGDR2 expression levels in peripheral blood of asthmatics might assist in selecting patients for treatment with specific antagonists.
RESUMEN
A validated imaging marker for beta-cell mass would improve understanding of diabetes etiology and enable new strategies in therapy development. We previously identified the membrane-spanning protein GPR44 as highly expressed and specific to the beta cells of the pancreas. The selective GPR44 antagonist MK-7246 was radiolabeled with carbon-11 and the resulting positron-emission tomography (PET) tracer [11C]MK-7246 was evaluated in a pig model and in vitro cell lines. The [11C]MK-7246 compound demonstrated mainly hepatobiliary excretion with a clearly defined pancreas, no spillover from adjacent tissues, and pancreatic binding similar in magnitude to the previously evaluated GPR44 radioligand [11C]AZ12204657. The binding could be blocked by preadministration of nonradioactive MK-7246, indicating a receptor-binding mechanism. [11C]MK-7246 showed strong potential as a PET ligand candidate for visualization of beta-cell mass (BCM) and clinical translation of this methodology is ongoing.
RESUMEN
Priming of autoreactive T cells in lymph nodes by dendritic cells (DCs) is critical for the pathogenesis of experimental autoimmune encephalitis (EAE). DC activation reflects a balance of pro- and anti-inflammatory signals. One anti-inflammatory factor is prostaglandin D2 signaling through its cognate receptor, D-prostanoid receptor 1 (PTGDR), on myeloid cells. Loss of PTGDR signaling might be expected to enhance DC activation and EAE but here we show that PTGDR-/- mice developed only mild signs of MOG35-55 peptide immunization-induced EAE. Compared to wild type mice, PTGDR-/- mice exhibited less demyelination, decreased leukocyte infiltration and diminished microglia activation. These effects resulted from increased pro-inflammatory responses in the lymph nodes, most notably in IL-1ß production, with the unexpected consequence of increased activation-induced apoptosis of MOG35-55 peptide-specific T cells. Conditional deletion of PTGDR on DCs, and not other myeloid cells ameliorated EAE. Together, these results demonstrate the indispensable role that PGD2/PTGDR signaling on DCs has in development of pathogenic T cells in autoimmune demyelination.
Asunto(s)
Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Susceptibilidad a Enfermedades , Encefalomielitis Autoinmune Experimental/etiología , Encefalomielitis Autoinmune Experimental/metabolismo , Prostaglandina D2/metabolismo , Transducción de Señal , Traslado Adoptivo/métodos , Animales , Antígeno B7-H1/metabolismo , Biomarcadores , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/patología , Encefalomielitis Autoinmune Experimental/terapia , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Recuento de Linfocitos , Ratones , Ratones Noqueados , Receptor de Muerte Celular Programada 1/metabolismo , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/genética , Receptores de Prostaglandina/metabolismo , Especificidad del Receptor de Antígeno de Linfocitos T , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
BACKGROUND AND OBJECTIVE: Prostaglandin D2 receptors are acquiring a relevant role as potential therapeutic targets in allergy. PTGDR has been described as a candidate gene in allergic disease, although functional studies on this gene are lacking. Objective: The objective of this case-control study was to investigate the potential role of PTGDR in allergy. METHODS: The study population comprised 195 allergic patients and 112 healthy controls. The PTGDR promoter polymorphisms -1289G>A, -1122T>C, -881C>T, -834C>T, -613C>T, -549T>C, -441C>T, -197T>C, and -95G>T were amplified by polymerase chain reaction (PCR) and sequenced. PTGDR expression levels were analyzed using quantitative PCR and normalized to GAPDH and TBP mRNA levels. All procedures were performed following the Minimum Information for Publication of Quantitative Real-Time PCR Experiment guidelines. RESULTS: PTGDR expression levels were significantly higher in allergic patients than in controls (P<.001). Receiver operating characteristic analysis for expression of PTGDR showed a sensitivity of 81.4% compared with 67% for IgE levels. In addition, differences in the genotypic distribution of the polymorphisms -1289G>A and -1122T>C were found in allergic patients (P=.009). CONCLUSIONS: The results indicate that PTGDR overexpression is associated with allergy. The polymorphisms -1289G>A and -1122T>C partly explain the variation in expression we observed. PTGDR expression could have a potential role as a biomarker and pharmacogenetic factor in allergy.
Asunto(s)
Hipersensibilidad/genética , Receptores Inmunológicos/genética , Receptores de Prostaglandina/genética , Adulto , Anciano , Biomarcadores , Femenino , Genotipo , Humanos , Hipersensibilidad/sangre , Inmunoglobulina E/sangre , Masculino , Persona de Mediana Edad , Regiones Promotoras Genéticas , ARN Mensajero , Adulto JovenRESUMEN
BACKGROUND/AIMS: This study aimed to explore the effect of microRNA-592-5p (miR-592-5p) on hypoxic-ischemic brain damage (HIBD)-induced hippocampal neuronal injury in a neonatal mouse model relative to the involvement of one target gene, PTGDR, and the PGD2/ DP signaling pathway. METHODS: A total of 30 neonatal mice aged 7 days were randomly selected to establish an HIBD mouse model. Hippocampal neuronal cells were transfected into a control group, a blank group, a negative control (NC) group, an miR-592-5p mimics group, an miR-592-5p inhibitors group, an siRNA-PTGDR group and an miR-592-5p inhibitors + siRNA-PTGDR group. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analyses were performed to detect the expression levels of miR-592-5p, PTGDR, DP2, Bcl-2 and Bax in tissues and cells. Cell proliferation, cell cycle and apoptosis were detected by MTT assay and flow cytometry, respectively. RESULTS: The expression levels of miR-592-5p and Bcl-2 decreased, while the expression levels of PTGDR, DP2 and Bax increased in the HIBD group. PTGDR is a target gene of miR-592-2p. Compared with the NC and blank groups, the expression levels of PTGDR, DP2 and Bax decreased, while the expression levels of miR-592-5p and Bcl-2 increased in the miR-592-5p mimics group. The siRNA-PTGDR group showed the same trend as that observed in the miR-592-5p mimics group, except with no difference in miR-592-5p expression. The miR-592-5p inhibitors group showed an opposite gene expression trend compared to that in the miR-592-5p mimics group. The S phase of the cell cycle was prolonged, the G1 phase was reduced, proliferation was increased, and the apoptosis rate was decreased in the siRNA-PTGDR and miR-592-5p mimics groups. Opposite trends for cell cycle, proliferation and apoptosis were observed in the miR-592-5p inhibitors group. CONCLUSIONS: Our study suggests that miR-592-5p upregulation protects against hippocampal neuronal injury caused by HIBD by targeting PTGDR and inhibiting the PGD2/DP signaling pathway.
Asunto(s)
Hipoxia-Isquemia Encefálica/patología , MicroARNs/metabolismo , Prostaglandina D2/metabolismo , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Animales , Animales Recién Nacidos , Apoptosis , Proliferación Celular , Células Cultivadas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Hipocampo/citología , Hipocampo/metabolismo , Hipocampo/patología , Hipoxia-Isquemia Encefálica/metabolismo , Ratones , MicroARNs/antagonistas & inhibidores , MicroARNs/genética , Neuronas/metabolismo , Neuronas/patología , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Interferencia de ARN , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/genética , Receptores de Prostaglandina/antagonistas & inhibidores , Receptores de Prostaglandina/genética , Transducción de Señal , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación hacia Arriba , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
BACKGROUND AND OBJECTIVE: Vitamin A has been linked to the development of allergic diseases although its role is not fully understood, Retinoic acid (RA), a metabolite of Vitamin A, has been previously associated with the prostaglandin pathway, and PTGDR, a receptor of PGD2, has been proposed as a candidate gene in allergy and asthma. Considering the role of PTGDR in allergy, the goal of this study was to analyze the effect of RA on the activation of the promoter region of the PTGDR gene. METHODS: A549 lung epithelial cells were transfected with 4 combinations of genetic variants of the PTGDR promoter and stimulated with all-trans RA (ATRA); luciferase assays were performed using the Dual Luciferase Reporter System, and real-time quantitative polymerase chain reaction was used to measure the expression of PTGDR, CYP26A1, RARA, RARB, RARG, and RXRA in basal A549 cell cultures and after ATRA treatment. We also performed an in silico analysis. RESULTS: After ATRA treatment increased expression of CYP26A1 (12-fold) and RARB (4-fold) was detected. ATRA activated PTGDR promoter activity in transfected cells (P<.001) and RA response element sequences were identified in silico in this promoter region. CONCLUSIONS: RA modulated PTGDR promoter activity. Differential response to RA and to new treatments based on PTGDR modulation could depend on genetic background in allergic asthmatic patients.