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PTGDR2 Expression in Peripheral Blood as a Potential Biomarker in Adult Patients with Asthma. J Pers Med 2021; 11:jpm11090827. [PMID: 34575604 PMCID: PMC8468563 DOI: 10.3390/jpm11090827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/20/2021] [Accepted: 08/21/2021] [Indexed: 12/17/2022] Open
Abstract
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.
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García-Sánchez A, Marcos-Vadillo E, Sanz C, Estravís M, Isidoro-García M, Dávila I. PTGDR expression is upregulated through retinoic acid receptors (RAR) mechanism in allergy. PLoS One 2019; 14:e0215086. [PMID: 30986261 PMCID: PMC6464170 DOI: 10.1371/journal.pone.0215086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/26/2019] [Indexed: 12/29/2022] Open
Abstract
Functional studies suggest that promoter polymorphisms of the Prostaglandin D Receptor (PTGDR) gene can be involved in asthma. All-trans Retinoic acid (ATRA) has also been linked to allergic diseases. We have previously described the PTGDR promoter activation mediated by ATRA through response elements (RARE) at position -549T> C. In this study we aimed to analyze the effect of retinoic acid (RA) on the expression of PTGDR, the production of cytokines as well as to evaluate the binding of RA receptors to RA-Response Elements (RARE) sequences. A549 cells were transfected with vectors carrying different PTGDR haplotypes and treated with all-Trans Retinoic Acid (ATRA). PTGDR expression was measured by qPCR. Chromatin Immunoprecipitation assays (ChIP) were performed in ATRA stimulated KU812 cells and in PBMCs of patients carrying CTCT, CCCC or CCCT haplotypes. In addition, a broad panel of cytokines was analyzed by cytometric bead assay in A549 cells. The expression of PTGDR increased in A549 cells transfected with PTGDR-variants. The CCCC haplotype showed a significantly higher expression compared with CTCT. However, we found that RA up-regulated PTGDR expression through RARα mainly in the CTCT variant. Experiments on PBMCs from allergic patients carrying the -549T and -549C variant of the PTGDR promoter after ATRA and RAR antagonist administration confirmed the modulation of PTGDR by ATRA. The cytokine analysis showed that IL4 and IL6 levels were significantly increased in A549 cells transfected with PTGDR. In addition, ATRA treatment decreased the levels of IL4, IL6 and TNFα in A549 cells, whereas it increased IL4 and TNFα levels in PTGDR-transfected cells. We observed genetic differences in the regulation of PTGDR by ATRA that could contribute to the phenotypic differences observed in allergic patients. Our findings showed that RAR modulation by PTGDR might have an impact on Th2 responses, suggesting that RAR could be a potential therapeutic target in allergic inflammation.
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Affiliation(s)
- Asunción García-Sánchez
- Department of Biomedical and Diagnostic Sciences, University of Salamanca, Salamanca, Spain
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
| | - Elena Marcos-Vadillo
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
- Department of Clinical Biochemistry, Salamanca University Hospital, Salamanca, Spain
| | - Catalina Sanz
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
- Department of Microbiology and Genetics, University of Salamanca, Salamanca, Spain
| | - Miguel Estravís
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
| | - María Isidoro-García
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
- Department of Clinical Biochemistry, Salamanca University Hospital, Salamanca, Spain
- Department of Medicine, University of Salamanca, Salamanca, Spain
| | - Ignacio Dávila
- Department of Biomedical and Diagnostic Sciences, University of Salamanca, Salamanca, Spain
- Institute for Biomedical Research of Salamanca, IBSAL, Salamanca, Spain
- Asthma, Allergic and Adverse Reactions (ARADyAL) Network for Cooperative Research in Health of Instituto de Salud Carlos III, Salamanca University Hospital, Salamanca, Spain
- Department of Allergy, Salamanca University Hospital, Salamanca, Spain
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