Project description:Background: Alternative polyadenylation (APA) is emerging as a widespread mechanism of gene regulation. The usage of APA sites allows a single gene to encode multiple mRNA transcripts with different 3'-untranslated region (3'UTR) lengths. Many disease processes reflect the importance of the regulation of APA site switching. The objective of this study was to explore the profiling of tandem APA sites in nasal polyps compared with nasal uncinate process mucosa. Methods: Sequencing of APA sites (SAPAS) based on second-generation sequencing technology was undertaken to investigate the use of tandem APA sites and identify gene expression patterns in samples from the nasal polyps and nasal uncinate process mucosa of two patients with chronic rhinosinusitis with nasal polyps. The findings of the SAPAS analysis were validated via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results: First, the results showed a switching of 3'UTR lengths in nasal polyps compared with nasal uncinate process mucosa. From the two patients, 105 overlapping genes in the nasal polyps were switched to distal poly(A) sites, and 90 such genes were switched to proximal poly(A) sites. Several Gene Ontology terms were enriched in the list of genes with switched APA sites, including transcription regulation, cell cycle, apoptosis, and metabolism. Second, we detected genes that showed differential expression with at least a 3-fold difference between nasal polyp tissue and nasal uncinate process mucosa. Between the two sample types, 627 genes exhibited differential expression. The qRT-PCR results confirmed our SAPAS results. Conclusion: APA site-switching events of 3'UTRs are prevalent in nasal polyp tissue, and the regulation of gene expression mediated by APA may play an important role in the formation and persistence of nasal polyps. Our results may provide new insights into the possible pathophysiologic processes involved in nasal polyps. Investigate the use of tandem APA sites of 3'ends of mRNAs using second-generation sequencing technology.

Project description:Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by persistent symptoms associated to the development of nasal polyps. To this day, the molecular mechanisms involved are still not well defined. However, it has been suggested that a sustained inflammation as allergy is involved in its onset. In this pilot study, we aimed to look into the effect of the allergic status of the patient and in their underlying mechanisms. To achieve this, we recruited 22 patients with CRSwNP and classified them in non-allergic and allergic using ImmunoCAP ISAC molecular diagnosis. Plasma samples were analyzed using liquid chromatography coupled to mass spectrometry (LC-MS). Subsequently, the identified changed metabolites from plasma that were commercially available were then analyzed by targeted analysis in some nasal polyps. Additionally, nasal polyp and mucosa tissue samples were examined for eosinophils and neutrophils. We found that 9 out of the 22 patients were sensitized to some aeroallergens (named as allergic). The other 13 patients had no sensitizations (non-allergic). Regarding metabolomics, we found that bilirubin, cortisol, lysophosphatidylcholines (LPCs) 16:0, 18:0 and 20:4 and lysophosphatidylinositol (LPI) 20:4, metabolites that are usually related to a sustained allergic inflammation, were unexpectedly increased in the plasma of non-allergic patients with CRSwNP compared to allergic patients with CRSwNP. LPC 16:0, LPC 18:0 and LPI 20:4 metabolites followed the same trend in the nasal polyp as they did in plasma. Comparison of nasal polyps with nasal mucosa tissue showed a significant increase in eosinophils (p < 0.001) and neutrophils (p < 0.01) in allergic patients with CRSwNP. There were also more eosinophils in the polyps of non-allergic patients with CRSwNP than in their nasal mucosa (p <0.01). The polyps from non-allergic patients with CRSwNP had less eosinophils than the polyps of allergic patients with CRSwNP (p < 0.05). Our data suggests that there is a systemic inflammatory response associated to CRSwNP in the absence of allergy, which could be accountable for the nasal polyp development. Allergic patients with CRSwNP presented a higher number of eosinophils located in nasal polyps suggesting that eosinophilia might be connected to the development of nasal polyps in these patients.

Project description:Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) in western countries is characterized by eosinophilia, IgE production and Th2 cytokine expression. Type 2 innate lymphoid cells (ILC2) from polyps produce IL-5 and IL-13 in response to IL-25 and IL-33 although the relevance of this axis to local mucosal T cell responses is unknown. Objective: To investigate the role of the IL-25/IL-33 axis in local mucosal T cell responses in CRSwNP. Methods: Polyp tissue and blood were obtained from patients undergoing nasal polypectomy. Control nasal biopsies and blood were obtained from healthy volunteers. Tissue was cultured in a short-term explant model. T cell surface phenotype/intracellular cytokines were assessed by flow cytometry. TCR VÎ² analysis was performed with the immunoSEQ assay. Microarrays were performed for gene expression analysis. Results: Using nasal polyp tissue, numerous IL-25 receptor (IL-17RB) positive polarized Th2 cells were identified which were absent in the healthy nasal mucosa and periphery. IL-17RB+CD4+ polyp Th2 cells co-expressed ST2 (IL-33 receptor) and responded to IL-25 and IL-33 with enhanced IL-5 and IL-13 production. Within IL-17RB+CD4+ T cells several identical TCR VÎ² CDR3 sequences were identified in different subjects suggesting clonal expansion driven by a common antigen. Abundant IL-17 producing T cells were observed in healthy nasal mucosal and polyp populations with Th17-related genes the most overexpressed compared to peripheral blood T cells. Conclusion: IL-25 and IL-33 may interact locally with IL-17RB+ST2+ polyp T cells to augment Th2 responses in CRSwNP. A local Th17 response may be the default signature in healthy nasal mucosal immune homeostasis. Three biological replicates. T-helper cells were isolated nasal polyps by explant culture from patients with chronic rhinosinusitis. Cells were then sorted based upon expression of IL17RB by flow cytometric sorting. Resting and activated IL-17RB+ve cells were compared with resting and activated IL-17RB-ve cells.

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A global analysis of tandem 3'UTRs in eosinophilic chronic rhinosinusitis with nasal polyps

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