Upregulation of Platelet-Activating Factor Receptor Expression and Lyso-Platelet-Activating Factor Isoforms in Human Nasal Polyp Tissues

Abstract

Background: The Platelet-Activating Factor (PAF)/receptor (PAFR) system is involved in asthma and allergic rhinitis; however, its role in chronic rhinosinusitis (CRS) is still unclear. This study aimed to assess the expression of PAFR and the concentration of Lyso-PAF isoforms in the nasal polyps (NP) of patients suffering from CRS with/without comorbidities such as asthma and NSAID-exacerbated respiratory disease (N-ERD) compared to healthy nasal mucosa (NM) from control subjects. Methods: NM (n = 8) and NP tissues were obtained from patients undergoing surgery for septal deviation/turbinate hypertrophy or endoscopic sinus surgery, respectively. Three phenotypes were studied: CRSwNP with no asthma (n = 6), CRSwNP with non-steroidal anti-inflammatory drug (NSAID)-tolerant asthma (n = 6), and CRSwNP with NSAID-exacerbated respiratory disease (n = 6). PAFR protein and mRNA were assessed via immunochemistry, immunofluorescence, Western blot, and real-time quantitative PCR. Lyso-PAF isoforms (C16, C18, and C18:1) were quantified via mass spectrometry. Results: PAFR protein was expressed in the NM and NP, concretely in epithelial cells and submucosal glands. Compared to NM, PAFR mRNA expression was higher in all NP phenotypes (p < 0.05) while all Lyso-PAF isoform concentrations were higher in the NP from asthmatic patients (p < 0.05). Lyso-PAF C16 and C18 concentrations were higher in the NP from asthmatic patients than in the NP from patients without asthma. Conclusions: The PAF/PAFR system could play a pathophysiological role in CRSwNP pathogenesis.

Severe Type 2 Inflammation Leads to High Platelet-Activating-Factor-Associated Pathology in Chronic Rhinosinusitis with Nasal Polyps—A Hierarchical Cluster Analysis Using Bulk RNA Barcoding and Sequencing

“…Additionally, there was no difference between nonECRS and ECRS in PTAFR gene expression. These results demonstrating significant upregulations in nonECRS and ECRS compared to the Ctrl and no difference between nonECRS and ECRS in PTAFR gene expression have been previously demonstrated [27] and suggest that clinical classification based on the JESREC criteria or status with/without comorbid asthma and/or AERD may be unrelated to PAF metabolism. On the other hand, the upregulation of PTAFR gene expression in nasal polyps from both nonECRS and ECRS suggests that PTAFR upregulation, enhancing the possibility of PAF-signaling upregulation, is associated with the formation and/or maintenance of nasal polyps.…”

“…Previous reports have mentioned differences in lyso-PAF concentration between normal nasal polyps and nasal polyps with AERD, suggesting an association between airway inflammation and/or disease severity and lyso-PAF concentration [27]. Other papers have also mentioned that human nasal polyps with severe eosinophil infiltration exhibit a high PAF concentration [10].…”

“…A second-strand synthesis module (NEB, #E6111) was used for double-stranded cDNA synthesis. In-house MEDS-B Tn5 transposase [27,28] was used for augmentation, and libraries were amplified for 10 cycles of PCR using Phusion High-Fidelity DNA Polymerase (Thermo Scientific, Waltham, MA, USA, #M0530) with the following primers (5 ′ -AATGATACGGCGACCACCGAGATCTACACindexGTTCAGAGTTCTACAGTCCGA-3 ′ , 5 ′ -CAAGCAGAAGACGGCATACGAGATindexGTCTCGTGGGCTCGGAGATGT-3'). An Illumina NovaSeq6000 was used to obtain 15 bp of barcode read (Read1) and 81 bp of insert read (Read2).…”

“…The role of PAF in the pathogenesis of allergic rhinitis has been demonstrated [26], but the role of PAF in the pathogenesis of CRSwNP was underestimated in that study. The intricate relationship between PAF and the pathophysiology of CRSwNP, which includes ECRS, with AERD often exhibiting an anaphylactic reaction after the administration of NSAIDS, suggests a potential link between PAF metabolism and its pathophysiology, including the formation and maintenance of nasal polyps derived from vascular permeability associated with plasma extravasation [11][12][13]27].…”