Single cell RNA sequencing of human eosinophils from nasal polyps reveals eosinophil heterogeneity in chronic rhinosinusitis tissue.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation in the United States, but the actual roles that eosinophils play in CRSwNP remain largely unclear. OBJECTIVE: To reveal the roles and heterogeneity of eosinophils in nasal polyp (NP) tissue, we performed single cell RNA sequencing (scRNA-Seq) analysis of NP tissue. METHODS: Sinonasal tissues (NP and control sinus tissue) and patient matched peripheral blood (PB) samples were obtained from 5 control patients and 5 patients with CRSwNP. Eosinophils were enriched before processing for scRNA-Seq. The gene expression profiles in eosinophils were determined by microwell-based scRNA-Seq technology (BD Rhapsody platform). We predicted the overall function of NP eosinophils by Gene Ontology (geneontology.org) enrichment and pathway analyses and confirmed expression of selected genes by flow cytometry. RESULTS: After filtering out contaminating cells, we detected 5,542 eosinophils from control PB, 3,883 eosinophils from CRSwNP PB, 101 eosinophils from control sinus tissues (not included in further analyses), and 9,727 eosinophils from NPs by scRNA-Seq. We found that 204 genes were downregulated and 354 genes upregulated in NP eosinophils compared to all PB eosinophils (>1.5-fold, Padj < .05). Upregulated genes in NP eosinophils were associated with activation, cytokine-mediated signaling, growth factor activity, NF-κB signaling, and antiapoptotic molecules. NP eosinophils displayed 4 clusters revealing potential heterogeneity of eosinophils in NP tissue. CONCLUSIONS: Elevated eosinophils in NP tissue appear to exist in several subtypes that may play important pathogenic roles in CRSwNP, in part by controlling inflammation and hyperproliferation of other cells.

IL-13 and IL-13-induced periostin levels are specifically decreased in patients following endoscopic sinus surgery for chronic rhinosinusitis.

BACKGROUND: Type 2 (T2) inflammation plays a pathogenic role in chronic rhinosinusitis (CRS). The effects of endoscopic sinus surgery (ESS) on T2 inflammation are unknown. OBJECTIVE: The aim of this study was to compare T2 inflammatory biomarkers from middle meatal (MM) mucus for distinguishing patients with CRS from CRS-free patients, identifying major phenotypes (CRS without nasal polyps [CRSsNP] and CRS with nasal polyps [CRSwNP]), assessing endotypic change, and establishing cross-sectional and longitudinal outcomes in patients undergoing ESS. METHODS: MM mucus samples were collected from patients with CRSsNP and patients with CRSwNP before and 6 to 12 months after ESS and compared with samples from CRS-free control patients. T2 biomarkers were evaluated both continuously and using threshold-based definitions of T2 endotype to identify relationships with patient-reported (based on the 22-Item Sinonasal Outcomes Test and Chronic Rhinosinusitis Patient-Reported Outcomes Measure) and clinician-reported (radiographic and endoscopic) severity. Linear mixed models were developed to analyze clinical variables associated with T2 biomarker levels. RESULTS: A total of 154 patients with CRS (89 with CRSsNP and 65 with CRSwNP) were enrolled, with a mean interval of 9 months between ESS and follow-up. An analysis of pre-ESS MM mucus samples revealed elevated levels of T2 mediators in patients with CRSwNP versus in patients with CRSsNP and CRS-free controls. Temporally stable correlations between levels of IL-13 and IL-5, levels of periostin and complement 5a, and levels of eosinophil cationic protein (ECP) and eotaxin-3 were observed. On this basis and on the basis of pathologic significance, levels of IL-13, periostin and ECP were further analyzed. After ESS, levels of IL-13 and periostin decreased significantly, whereas ECP levels remained unchanged. Across pre- and post-ESS evaluation, the T2 endotype was associated with radiographic severity but did not predict outcomes. CRSwNP status and African American race were associated with higher levels of IL-13 and periostin, whereas ECP level was higher in patients undergoing extensive surgery. CONCLUSION: ESS decreased levels of IL-13 and periostin in the middle meatus. T2 inflammation after ESS was correlated with patient- and clinician-reported severity across phenotypes. Pre-ESS T2 inflammation did not predict post-ESS outcomes.

Thioarylation of 6-Amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic Acid (IminoKdo): Access to 3,6-Disubstituted Picolinates and Mechanistic Insights.

In this work, we present a metal-free coupling protocol for the regio- and stereoselective C3-thioarylation of 6-amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic acid (iminoKdo). The developed procedure enables the coupling of electron-rich, electron-deficient, and hindered arylthiols, providing a series of C3-modified iminoKdo derivatives in moderate to good yields. Elucidation of active species through controlled experimental studies and time-lapse 31 P NMR analysis provides insights into the reaction mechanism. We demonstrate that, following a tandem Staudinger/aza-Wittig reaction of an azido-containing keto ester, an inseparable equimolar mixture of imine/enamine is formed. The enamine then undergoes a Stork-like nucleophilic attack with the in situ-formed disulfide reagent, resulting in the formation of the coupling products. Additionally, we describe a rarely reported acid-promoted aromatization of the C3-thioarylated iminoKdo skeleton into 3,6-disubstituted picolinates, which are reminiscent of dichotomines.

Genetics and epigenetics of chronic rhinosinusitis.

Discerning the genetics and epigenetics of chronic rhinosinusitis (CRS) may optimize outcomes through early diagnostics, personalized and novel therapeutics, and early prognostication. CRS associated with cystic fibrosis and primary ciliary dyskinesia has well-characterized genetic mutations. Most CRS subjects, however, do not exhibit identifiable monogenic alterations. Clustering in related individuals is seen in CRS with nasal polyps. Spouses of subjects with CRS without nasal polyps also may be at increased risk of the same disease. These observations generate questions on genetic and environmental influences in CRS. Genome-wide association studies have identified variations and polymorphisms between CRS and control subjects in genes related to innate and adaptive immunity. Candidate gene and transcriptomics studies have investigated and identified genetic variations related to immunity, inflammation, epithelial barrier function, stress-response, antigen processing, T-cell regulation, and cytokines in CRS. Epigenetic studies have identified mechanisms through which environmental factors may affect these gene functions. However, causality is not determined for most variations. Inferences drawn from these data must be measured because most investigations report unreplicated results from small study populations. Large, replicated studies in tight cohorts across diverse populations remain a pressing need in studying CRS genetics.

Evidence that oncostatin M synergizes with IL-4 signaling to induce TSLP expression in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Oncostatin M (OSM) may promote type 2 inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP) by inducing thymic stromal lymphopoietin (TSLP). OBJECTIVE: We sought to study the impact of OSM on TSLP synthesis and release from nasal epithelial cells (NECs). METHODS: OSM receptors, IL-4 receptors (IL-4R), and TSLP were evaluated in mucosal tissue and primary NECs from patients with CRSwNP by quantitative PCR and immunofluorescence. Air-liquid interface-cultured NECs were stimulated with cytokines, including OSM, and quantitative PCR, ELISA, Western blot, and flow cytometry were used to assess the expression of OSM receptors, IL-4R, and TSLP. RESULTS: Increased levels of OSM receptor ß chain (OSMRß), IL-4Rα, and TSLP were observed in nasal polyp tissues and primary epithelial cells from nasal polyps of patients with CRSwNP compared with control tissues or cells from control subjects. The level of expression of OSMRß in tissue was correlated with levels of both IL-4Rα and TSLP. OSM stimulation of NECs increased the expression of OSMRß and IL-4Rα. Stimulation with IL-4 plus OSM augmented the production of TSLP; the response was suppressed by a signal transducer and activator of transcription 6 inhibitor. Stimulation of NECs with IL-4 plus OSM increased the expression of proprotein convertase subtilisin/kexin 3, an enzyme that truncates and activates TSLP. CONCLUSIONS: OSM increases the expression of IL-4Rα and synergizes with IL-4 to induce the synthesis and release of TSLP in NECs. Because the combination of IL-4 and OSM also augmented the expression of proprotein convertase subtilisin/kexin 3, these results suggest that OSM can induce both synthesis and posttranslational processing/activation of TSLP, promoting type 2 inflammation.

Derivation of pancreatic acinar cell carcinoma cell line HS-1 as a patient-derived tumor organoid.

Acinar cell carcinoma (ACC) of the pancreas is a malignant tumor of the exocrine cell lineage with a poor prognosis. Due to its rare incidence and technical difficulties, few authentic human cell lines are currently available, hampering detailed investigations of ACC. Therefore, we applied the organoid culture technique to various types of specimens, such as bile, biopsy, and resected tumor, obtained from a single ACC patient. Despite the initial propagation, none of these organoids achieved long-term proliferation or tolerated cryopreservation, confirming the challenging nature of establishing ACC cell lines. Nevertheless, the biopsy-derived early passage organoid developed subcutaneous tumors in immunodeficient mice. The xenograft tumor histologically resembled the original tumor and gave rise to infinitely propagating organoids with solid features and high levels of trypsin secretion. Moreover, the organoid stained positive for carboxylic ester hydrolase, a specific ACC marker, but negative for the duct cell marker CD133 and the endocrine lineage marker synaptophysin. Hence, we concluded the derivation of a novel ACC cell line of the pure exocrine lineage, designated HS-1. Genomic analysis revealed extensive copy number alterations and mutations in EP400 in the original tumor, which were enriched in primary organoids. HS-1 displayed homozygous deletion of CDKN2A, which might underlie xenograft formation from organoids. Although resistant to standard cytotoxic agents, the cell line was highly sensitive to the proteasome inhibitor bortezomib, as revealed by an in vitro drug screen and in vivo validation. In summary, we document a novel ACC cell line, which could be useful for ACC studies in the future.

Insights from managing clinical issues in distal pancreatectomy with en bloc coeliac axis resection: experiences from 626 patients.

BACKGROUND: Distal pancreatectomy with en bloc coeliac axis resection (DP-CAR) for pancreatic body cancer has been reported increasingly. However, its large-scale outcomes remain undocumented. This study aimed to evaluate DP-CAR volume and mortality, preoperative arterial embolization for ischaemic gastropathy, the oncological benefit for resectable tumours close to the bifurcation of the splenic artery and coeliac artery using propensity score matching, and prognostic factors in DP-CAR. METHODS: In a multi-institutional analysis, 626 DP-CARs were analysed retrospectively and compared with 1325 distal pancreatectomies undertaken in the same interval. RESULTS: Ninety-day mortality was observed in 7 of 21 high-volume centres (1 or more DP-CARs per year) and 1 of 41 low-volume centres (OR 20.00, 95 per cent c.i. 2.26 to 177.26). The incidence of ischaemic gastropathy was 19.2 per cent in the embolization group and 7.9 per cent in the no-embolization group (OR 2.77, 1.48 to 5.19). Propensity score matching analysis showed that median overall survival was 33.5 (95 per cent c.i. 27.4 to 42.0) months in the DP-CAR and 37.9 (32.8 to 53.3) months in the DP group. Multivariable analysis identified age at least 67 years (HR 1.40, 95 per cent c.i. 1.12 to 1.75), preoperative tumour size 30 mm or more (HR 1.42, 1.12 to 1.80), and preoperative carbohydrate antigen 19-9 level over 37 units/ml (HR 1.43, 1.11 to 1.83) as adverse prognostic factors. CONCLUSION: DP-CAR can be performed safely in centres for general pancreatic surgery regardless of DP-CAR volume, and preoperative embolization may not be required. This procedure has no oncological advantage for resectable tumour close to the bifurcation of the splenic artery, and should be performed after appropriate patient selection.

Epigenetic responses to rhinovirus exposure in airway epithelial cells are correlated with key transcriptional pathways in chronic rhinosinusitis.

BACKGROUND: Viruses may drive immune mechanisms responsible for chronic rhinosinusitis with nasal polyposis (CRSwNP), but little is known about the underlying molecular mechanisms. OBJECTIVES: To identify epigenetic and transcriptional responses to a common upper respiratory pathogen, rhinovirus (RV), that are specific to patients with CRSwNP using a primary sinonasal epithelial cell culture model. METHODS: Airway epithelial cells were collected at surgery from patients with CRSwNP (cases) and from controls without sinus disease, cultured, and then exposed to RV or vehicle for 48 h. Differential gene expression and DNA methylation (DNAm) between cases and controls in response to RV were determined using linear mixed models. Weighted gene co-expression analysis (WGCNA) was used to identify (a) co-regulated gene expression and DNAm signatures, and (b) genes, pathways, and regulatory mechanisms specific to CRSwNP. RESULTS: We identified 5585 differential transcriptional and 261 DNAm responses (FDR <0.10) to RV between CRSwNP cases and controls. These differential responses formed three co-expression/co-methylation modules that were related to CRSwNP and three that were related to RV (Bonferroni corrected p < .01). Most (95%) of the differentially methylated CpGs (DMCs) were in modules related to CRSwNP, whereas the differentially expressed genes (DEGs) were more equally distributed between the CRSwNP- and RV-related modules. Genes in the CRSwNP-related modules were enriched in known CRS and/or viral response immune pathways. CONCLUSION: RV activates specific epigenetic programs and correlated transcriptional networks in the sinonasal epithelium of individuals with CRSwNP. These novel observations suggest epigenetic signatures specific to patients with CRSwNP modulate response to viral pathogens at the mucosal environmental interface. Determining how viral response pathways are involved in epithelial inflammation in CRSwNP could lead to therapeutic targets for this burdensome airway disorder.

Sinus inflammation and chronic rhinosinusitis are associated with a diagnosis of new onset asthma in the following year.

BACKGROUND: Chronic rhinosinusitis (CRS) and asthma commonly co-occur. No studies have leveraged large samples needed to formally address whether preexisting CRS is associated with new onset asthma over time. METHODS: We evaluated whether prevalent CRS [identified in two ways: validated text algorithm applied to sinus computerized tomography (CT) scan or two diagnoses] was associated with new onset adult asthma in the following year. We used electronic health record data from Geisinger from 2008 to 2019. For each year we removed persons with any evidence of asthma through the end of the year, then identified those with new diagnosis of asthma in the following year. Complementary log-log regression was used to adjust for confounding variables (e.g., sociodemographic, contact with the health system, comorbidities), and hazard ratios (HRs) and 95% confidence intervals (CI) were calculated. RESULTS: A total of 35,441 persons were diagnosed with new onset asthma and were compared to 890,956 persons who did not develop asthma. Persons with new onset asthma tended to be female (69.6%) and younger (mean [SD] age 45.9 [17.0] years). Both CRS definitions were associated (HR, 95% CI) with new onset asthma, with 2.21 (1.93, 2.54) and 1.48 (1.38, 1.59) for CRS based on sinus CT scan and two diagnoses, respectively. New onset asthma was uncommonly observed in persons with a history of sinus surgery. CONCLUSION: Prevalent CRS identified with two complementary approaches was associated with a diagnosis of new onset asthma in the following year. The findings may have clinical implications for the prevention of asthma.

Design, synthesis and glycosidase inhibition of DAB derivatives with C-4 peptide and dipeptide branches.

A series of DAB-peptide and DAB-dipeptide derivatives were synthesized from D-tartrate-derived nitrone 18. The DAB peptides 16 are derivatives of trans,trans-3,4-dihydroxy-L-proline. Glycosidase inhibition assay found four of them to be weak and selective bovine liver ß-galactosidase inhibitors, and the C-2' methyl substituted compound 23b showed the most potent ß-galactosidase inhibition (IC50 = 0.66 µM). Molecular docking studies revealed different docking modes of compound 23b compared to those of other DAB-peptides, and partial similarity of compound 23b to DGJ.

Design and synthesis of iso-allo-DNJ and L-isoDALDP derivatives: pursuit of potent and selective inhibitors of α-glucosidase.

A series of iso-allo-DNJ and L-isoDALDP derivatives were synthesized from dithioacetal 16 with sequential and highly diastereoselective Ho and Henry reactions, and aziridinium intermediate-mediated ring rearrangement as key steps. Glycosidase inhibition assay found four of them as selective α-glucosidase inhibitors, and the less substituted compound 30 showed more potent α-glucosidase inhibition (IC50 = 9.3 µM) than the others. Molecular docking study revealed different docking modes of the iso-allo-DNJ and L-isoDALDP derivatives from their parent compounds, and also the similarity of compound 30 to isofagomine.

Synthesis of the Purported Structure of Glyphaeaside C and Proposed Revisions to the Structures of the Glyphaeaside Alkaloids.

The 10 glyphaeaside alkaloids isolated from the roots of Glyphaea brevis were originally purported as piperidine-based 1-C-alkylated iminosugars, with the A-, B-, and C-type glyphaeasides bearing l-DFJ, DGJ, and DNJ ring configurations, respectively. Subsequent investigations have revealed glyphaeaside C as being a pyrrolidine-based iminosugar with a DMDP ring configuration via total synthesis of the revised structure. In this work, side chain diastereomers of the originally purported structure of glyphaeaside C (10) and two related α-1-C-alkylated DNJ derivatives were synthesized from a common precursor, which was prepared in turn via stereoselective Grignard addition to a protected d-glycosylamine, followed by a reductive amination-cyclization sequence. Glycosidase inhibitory activity studies revealed general structure 10 as having potent inhibition against various α-glucosidases and weak inhibition against almond ß-glucosidase in agreement with similar DNJ-based iminosugars and in contrast to natural glyphaeaside C, suggesting that the (1,2-dihydroxy-3-phenyl)propyl moiety does not play a particularly vital role in the inhibitory modes of action of either compound. Furthermore, the absolute configuration of natural glyphaeaside C was proposed as that of d-DMDP, and the structures of the A- and B-type glyphaeasides were revised as 1-deoxy-DALDP and DALDP derivatives, respectively, based on interpretation of their reported NMR spectroscopic data.

Mechanisms and pathogenesis of chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by local inflammation of the upper airways and is historically divided into 2 main phenotypes: CRS with nasal polyps and CRS without nasal polyps. Inflammation in CRS is mainly characterized by 3 endotypes based on elevation of canonical lymphocyte cytokines: type (T) 1 (T1) by TH1 cytokine IFN-γ, T2 by TH2 cutokines IL-4, IL-5, and IL-13, and T3 by TH17 cytokines including IL-17. Inflammation in both CRS without nasal polyps and CRS with nasal polyps is highly heterogeneous, and the frequency of various endotypes varies geographically around the world. This finding complicates establishment of a unified understanding of the mechanisms of pathogenesis in CRS. Sinonasal epithelium acts as a passive barrier, and epithelial barrier dysfunction is a common feature in CRS induced by endotype-specific cytokines directly and indirectly. The sinonasal epithelium also participates in both innate immunity via recognition by innate pattern-recognition receptors and promotes and regulates adaptive immunity via release of chemokines and innate cytokines including thymic stromal lymphopoietin. The purpose of this review was to discuss the contribution of the epithelium to CRS pathogenesis and to update the field regarding endotypic heterogeneity and various mechanisms for understanding pathogenesis in CRS.

Strong and consistent associations of precedent chronic rhinosinusitis with risk of non-cystic fibrosis bronchiectasis.

BACKGROUND: Chronic rhinosinusitis (CRS) and bronchiectasis commonly co-occur, but most prior studies were not designed to evaluate temporality and causality. OBJECTIVES: In a sample representing the general population in 37 counties in Pennsylvania, and thus the full spectrum of sinonasal and relevant lung diseases, we aimed to evaluate the temporality and strength of associations of CRS with non-cystic fibrosis bronchiectasis. METHODS: We completed case-control analyses for each of 3 primary bronchiectasis case finding methods. We used electronic health records to identify CRS and bronchiectasis with diagnoses, procedure orders, and/or specific text in sinus or chest computerized tomography scan radiology reports. The controls never had any indication of bronchiectasis and were frequency-matched to the 3 bronchiectasis groups on the basis of age, sex, and encounter year. There were 5,329 unique persons with bronchiectasis and 33,363 without bronchiectasis in the 3 analyses. Important co-occurring conditions were identified with diagnoses, medication orders, and encounter types. Logistic regression was used to evaluate associations (odds ratios [ORs] and 95% CIs) of CRS with bronchiectasis while adjusting for confounding variables. RESULTS: In adjusted analyses, CRS was consistently and strongly associated with all 3 bronchiectasis definitions. The strongest associations for CRS (ORs and 95% CIs) were those that were based on the text of sinus computerized tomography scan reports; the associations were generally stronger for CRS without nasal polyps (eg, OR = 4.46 [95% CI = 2.09-9.51] for diagnosis-based bronchiectasis). On average, CRS was identified more than 6 years before bronchiectasis. CONCLUSION: Precedent CRS was strongly and consistently associated with increased risk of bronchiectasis.

Prognostic factors for polyp recurrence in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps is frequently managed with endoscopic sinus surgery (ESS). Prior studies describe individual clinical variables and eosinophil density measures as prognostic for polyp recurrence (PR). However, the relative prognostic significance of these have not been extensively investigated. OBJECTIVES: We sought to evaluate the impact of PR on measures of disease severity post-ESS and quantify the prognostic value of various clinical variables and biomarkers. METHODS: Ninety-four patients with chronic rhinosinusitis with nasal polyps and prospectively biobanked polyp homogenates at the time of ESS were recruited 2 to 5 years post-ESS. Patients were evaluated with patient-reported outcome measures and endoscopic and radiographic scoring pre- and post-ESS. Biomarkers in polyp homogenates were measured with ELISA and Luminex. Relaxed least absolute shrinkage and selection operator regression optimized predictive clinical, biomarker, and combined models. Model performance was assessed using receiver-operating characteristic curve and random forest analysis. RESULTS: PR was found in 39.4% of patients, despite significant improvements in modified Lund-Mackay (MLM) radiographic and 22-item Sinonasal Outcomes Test scores (both P < .0001). PR was significantly associated with worse post-ESS MLM, modified Lund-Kennedy, and 22-item Sinonasal Outcomes Test scores. Relaxed least absolute shrinkage and selection operator identified 2 clinical predictors (area under the curve = 0.79) and 3 biomarkers (area under the curve = 0.78) that were prognostic for PR. When combined, the model incorporating these pre-ESS factors: MLM, asthma, eosinophil cationic protein, anti-double-stranded DNA IgG, and IL-5 improved PR predictive accuracy to area under the curve of 0.89. Random forest analysis identified and validated each of the 5 variables as the strongest predictors of PR. CONCLUSIONS: PR had strong associations with patient-reported outcome measures, endoscopic and radiographic severity. A combined model comprised of eosinophil cationic protein, IL-5, pre-ESS MLM, asthma, and anti-double-stranded DNA IgG could accurately predict PR.

Elevation of activated neutrophils in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is well characterized by type 2 (T2) inflammation characterized by eosinophilia in Western countries. However, the presence and roles of neutrophils in T2 CRSwNP are poorly understood. OBJECTIVE: We sought to clarify accumulation and inflammatory roles of neutrophils in CRSwNP in a Western population. METHODS: Sinonasal tissues and nasal lavage fluids were obtained from control patients and patients with CRS, and neutrophil markers were determined by ELISA. The presence of neutrophils in tissue was determined by flow cytometry. The gene expression profiles in neutrophils were determined by RNA sequencing. RESULTS: A neutrophil marker elastase was selectively elevated in nasal polyp (NP) tissue, whereas eosinophilic cationic protein (an eosinophil marker) was elevated in both uncinate and NP tissues of CRSwNP patients. Nasal lavage fluid myeloperoxidase (another neutrophil marker) was also significantly elevated in CRSwNP compared to control patients. Neutrophil markers were more greatly elevated in CRSwNP patients with recurrent disease. Flow cytometric analysis confirmed that neutrophil numbers were significantly elevated in NPs compared to control tissues. RNA sequencing analysis found that 344 genes were >3-fold and significantly elevated in NP neutrophils compared to peripheral blood neutrophils. Gene Ontology analysis suggested that the elevated genes in NP neutrophils were significantly associated with activation. Results suggest that neutrophils are accumulated in T2 NP tissues and that accumulated neutrophils are highly activated and contribute to inflammation in NPs. CONCLUSIONS: Neutrophils may play a heretofore unrecognized meaningful role in the pathogenesis of CRSwNP in Western countries and may be a potentially important therapeutic target in T2 CRSwNP.

Retinoic acid promotes fibrinolysis and may regulate polyp formation.

BACKGROUND: Patients with aspirin-exacerbated respiratory disease (AERD) regularly exhibit severe nasal polyposis. Studies suggest that chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by excessive fibrin deposition associated with a profound decrease in epithelial tissue plasminogen activator (tPA). Retinoids, including vitamin A and its active metabolite retinoic acid (RA), are necessary for maintaining epithelial function and well-known inducers of tPA in endothelial cells. OBJECTIVES: This study sought to determine whether endogenous retinoids are involved in NP pathophysiology and disease severity in patients with CRSwNP and AERD. METHODS: NP tissue was collected from patients with AERD or CRSwNP, and concentrations of retinoids and fibrinolysis markers were measured using ELISA. Normal human bronchial epithelial cells were stimulated alone or in combination with RA and IL-13 for 24 hours. RESULTS: This study observed lower retinoid levels in nasal polyps of patients with AERD than those with CRSwNP or healthy controls (P < .01). Levels of the fibrin-breakdown product d-dimer were the lowest in AERD polyps (P < .01), which is consistent with lower tPA expression (P < .01). In vitro, all-trans RA upregulated tPA levels in normal human bronchial epithelial cells by 15-fold and reversed the IL-13-induced attenuation of tPA expression in cultured cells (P < .01). CONCLUSIONS: RA, a potent inducer of epithelial tPA in vitro, is reduced in tissue from patients with AERD, a finding that may potentially contribute to decreased levels of tPA and fibrinolysis in AERD. RA can induce tPA in epithelial cells and can reverse IL-13-induced tPA suppression in vitro, suggesting the potential utility of RA in treating patients with CRSwNP and/or AERD.

Efficacy of an oral CRTH2 antagonist (AZD1981) in the treatment of chronic rhinosinusitis with nasal polyps in adults: A randomized controlled clinical trial.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease of the upper airways. AZD1981 is a selective antagonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 and other type 2 cells, including innate lymphoid cells type 2, eosinophils, and basophils. OBJECTIVE: To evaluate the efficacy of AZD1981 in reducing nasal polyp size when added to intranasal corticosteroids in adult patients with CRSwNP. METHODS: Eighty-one subjects (18-70 years of age) with CRSwNP were recruited and screened for trial eligibility from allergy and otolaryngology clinics from a single tertiary care site between June 2016 and August 2019. Eligible patients were randomized in a double-blind fashion to receive either AZD1981 (n = 22) or placebo (n = 21) orally three times a day for 12 weeks, added to intranasal corticosteroids. The primary endpoint was a change in nasal polyp score (NPS) at 12 weeks. Secondary endpoints included improvement in sinus computed tomography using Lund Mackay scoring, symptoms using visual analog scale, quality of life using Sino Nasal Outcome Test-22, and the Brief Smell Identification Test. RESULTS: Forty-three patients met the inclusion criteria and were enrolled. At 12 weeks, there was no difference in NPS change in the AZD1981 arm (mean 0, standard error 0.34, n = 15) compared with placebo (mean 0.20, standard error 0.36, n = 17); mean difference -0.20 (95% confidence interval: -1.21, 0.81; p = .69). No significant differences were observed for Lund Mackay score, symptoms, quality of life, or smell test. AZD1981 was well tolerated except for one case of hypersensitivity reaction. CONCLUSION: In patients with CRSwNP, the addition of AZD1981 to intranasal corticosteroids did not change nasal polyp size, radiographic scores, symptoms, or disease-specific quality of life.

Endotypes of chronic rhinosinusitis: Relationships to disease phenotypes, pathogenesis, clinical findings, and treatment approaches.

Chronic rhinosinusitis (CRS) is a common clinical syndrome that produces significant morbidity and costs to our health system. The study of CRS has progressed from an era focused on phenotype to include endotype-based information. Phenotypic classification has identified clinical heterogeneity in CRS based on endoscopically observed features such as presence of nasal polyps, presence of comorbid or systemic diseases, and timing of disease onset. More recently, laboratory-based findings have established CRS endotype based upon specific mechanisms or molecular biomarkers. Understanding the basis of widespread heterogeneity in the manifestations of CRS is advanced by findings that the three main endotypes, Type 1, 2, and 3, orchestrate the expression of three distinct large sets of genes. The development and use of improved methods of endotyping disease in the clinic are ushering in an expansion of the use of biological therapies targeting Type 2 inflammation now and perhaps other inflammatory endotypes in the near future. The purpose of this review is to discuss the phenotypic and endotypic heterogeneity of CRS from the perspective of advancing the understanding of the pathogenesis and improvement of treatment approaches and outcomes.

Diastereoselective Synthesis, Glycosidase Inhibition, and Docking Study of C-7-Fluorinated Casuarine and Australine Derivatives.

C-7-fluorinated derivatives of two important polyhydroxylated pyrrolizidines, casuarine and australine, were synthesized with organocatalytic stereoselective α-fluorination of aldehydes as the key step. The strategy is extensively applicable to some synthetically challenging fluorinated iminosugars and carbohydrates. The docking studies indicated that the potent inhibitions of trehalase and amyloglucosidase by the fluorinated polyhydroxylated pyrrolizidines are due to the interaction modes dominated by fluorine atoms in these iminosugars with the amino acids' residues of the corresponding enzymes. Steady interactions were established between the C-7 fluoride and a hydrophobic pocket in amyloglucosidase by untypical anion-π interactions. These unexpected docking modes and related structure-activity relationship studies emphasize the value of fluorination in the design of polyhydroxylated pyrrolizidine glycosidase inhibitors.