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Background: The role of Akt in nasal immunity is unstudied. Akt phosphorylates and activates endothelial nitric oxide synthase (eNOS) expressed in epithelial ciliated cells. Nitric oxide (NO) production by ciliated cells can have antibacterial and antiviral effects. Increasing nasal NO may be a useful antipathogen strategy in chronic rhinosinusitis (CRS). We previously showed that small‐molecule Akt activator SC79 induces nasal cell NO production and suppresses IL‐8 via the transcription factor Nrf‐2. We hypothesized that SC79 NO production may additionally have antibacterial effects. Methods: NO production was measured using fluorescent dye DAF‐FM. We tested effects of SC79 during co‐culture of Pseudomonas aeruginosa with primary nasal epithelial cells, using CFU counting and live–dead staining to quantify bacterial killing. Pharmacology determined the mechanism of SC79‐induced NO production and tested dependence on Akt. Results: SC79 induced dose‐dependent, Akt‐dependent NO production in nasal epithelial cells. The NO production required eNOS and Akt. The NO released into the airway surface liquid killed P. aeruginosa. No toxicity (LDH release) or inflammatory effects (IL8 transcription) were observed over 24 h. Conclusions: Together, these data suggest multiple immune pathways are stimulated by SC79, with antipathogen effects. This in vitro pilot study suggests that a small‐molecule Akt activator may have clinical utility in CRS or respiratory other infection settings, warranting future in vivo studies. [ABSTRACT FROM AUTHOR]

Introduction: Bitter taste receptors (T2Rs) are G protein-coupled receptors identified on the tongue but expressed all over the body, including in airway cilia and macrophages, where T2Rs serve an immune role. T2R isoforms detect bitter metabolites (quinolones and acyl-homoserine lactones) secreted by gram negative bacteria, including Pseudomonas aeruginosa, a major pathogen in cystic fibrosis (CF). T2R activation by bitter bacterial products triggers calcium-dependent nitric oxide (NO) production. In airway cells, the NO increases mucociliary clearance and has direct antibacterial properties. In macrophages, the same pathway enhances phagocytosis. Because prior studies linked CF with reduced NO, we hypothesized that CF cells may have reduced T2R/NO responses, possibly contributing to reduced innate immunity in CF. Methods: Immunofluorescence, qPCR, and live cell imaging were used to measure T2R localization, calcium and NO signaling, ciliary beating, and antimicrobial responses in air-liquid interface cultures of primary human nasal epithelial cells and immortalized bronchial cell lines. Immunofluorescence and live cell imaging was used to measure T2R signaling and phagocytosis in primary human monocyte-derived macrophages. Results: Primary nasal epithelial cells from both CF and non-CF patients exhibited similar T2R expression, localization, and calcium signals. However, CF cells exhibited reduced NO production also observed in immortalized CFBE41o-CF cells and non-CF 16HBE cells CRISPR modified with CF-causing mutations in the CF transmembrane conductance regulator (CFTR). NO was restored by VX-770/VX-809 corrector/potentiator pre-treatment, suggesting reduced NO in CF cells is due to loss of CFTR function. In nasal cells, reduced NO correlated with reduced ciliary and antibacterial responses. In primary human macrophages, inhibition of CFTR reduced NO production and phagocytosis during T2R stimulation. Conclusions: Together, these data suggest an intrinsic deficiency in T2R/NO signaling caused by loss of CFTR function that may contribute to intrinsic susceptibilities of CF patients to P. aeruginosa and other gram-negative bacteria that activate T2Rs. [ABSTRACT FROM AUTHOR]

T2R bitter taste receptors in airway motile cilia increase ciliary beat frequency (CBF) and nitric oxide (NO) production. Polymorphisms in some T2Rs are linked to disease outcomes in chronic rhinosinusitis (CRS) and cystic fibrosis (CF). We examined the expression of cilia T2Rs during the differentiation of human nasal epithelial cells grown at air–liquid interface (ALI). The T2R expression increased with differentiation but did not vary between CF and non-CF cultures. Treatment with Pseudomonas aeruginosa flagellin decreased the expression of diphenhydramine-responsive T2R14 and 40, among others. Diphenhydramine increased both NO production, measured by fluorescent dye DAF-FM, and CBF, measured via high-speed imaging. Increases in CBF were disrupted after flagellin treatment. Diphenhydramine impaired the growth of lab and clinical strains of P. aeruginosa, a major pathogen in CF and CF-related CRS. Diphenhydramine impaired biofilm formation of P. aeruginosa, measured via crystal violet staining, as well as the surface attachment of P. aeruginosa to CF airway epithelial cells, measured using colony-forming unit counting. Because the T2R agonist diphenhydramine increases NO production and CBF while also decreasing bacterial growth and biofilm production, diphenhydramine-derived compounds may have potential clinical usefulness in CF-related CRS as a topical therapy. However, utilizing T2R agonists as therapeutics within the context of P. aeruginosa infection may require co-treatment with anti-inflammatories to enhance T2R expression. [ABSTRACT FROM AUTHOR]

• De-ciliated squamous airway cells express intracellular T2R bitter taste receptors. • Intracellular bitter taste receptors activate nuclear and mitochondrial calcium elevation. • Calcium elevation causes depolarization of mitochondrial membrane and caspase activation. • Blocking calcium signaling prevents apoptosis. Bitter taste receptors (T2Rs) localize to airway motile cilia and initiate innate immune responses in retaliation to bacterial quorum sensing molecules. Activation of cilia T2Rs leads to calcium-driven NO production that increases cilia beating and directly kills bacteria. Several diseases, including chronic rhinosinusitis, COPD, and cystic fibrosis, are characterized by loss of motile cilia and/or squamous metaplasia. To understand T2R function within the altered landscape of airway disease, we studied T2Rs in non-ciliated airway cell lines and primary cells. Several T2Rs localize to the nucleus in de-differentiated cells that typically localize to cilia in differentiated cells. As cilia and nuclear import utilize shared proteins, some T2Rs may target to the nucleus in the absence of motile cilia. T2R agonists selectively elevated nuclear and mitochondrial calcium through a G-protein-coupled receptor phospholipase C mechanism. Additionally, T2R agonists decreased nuclear cAMP, increased nitric oxide, and increased cGMP, consistent with T2R signaling. Furthermore, exposure to T2R agonists led to nuclear calcium-induced mitochondrial depolarization and caspase activation. T2R agonists induced apoptosis in primary bronchial and nasal cells differentiated at air-liquid interface but then induced to a squamous phenotype by apical submersion. Air-exposed well-differentiated cells did not die. This may be a last-resort defense against bacterial infection. However, it may also increase susceptibility of de-differentiated or remodeled epithelia to damage by bacterial metabolites. Moreover, the T2R-activated apoptosis pathway occurs in airway cancer cells. T2Rs may thus contribute to microbiome-tumor cell crosstalk in airway cancers. Targeting T2Rs may be useful for activating cancer cell apoptosis while sparing surrounding tissue. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Succinate, although most famous for its role in the Krebs cycle, can be released extracellularly as a signal of cellular distress, particularly in situations of metabolic stress and inflammation. Solitary chemosensory cells (SCCs) express SUCNR1, the succinate receptor, and modulate type 2 inflammatory responses in helminth and protozoal infections in the small intestine. SCCs are the dominant epithelial source of interleukin‐25, as well as an important source of cysteinyl leukotrienes in the airway, and have been implicated as upstream agents in type 2 inflammation in chronic rhinosinusitis (CRS) and asthma. Methods: In this study, we used scRNAseq analysis, live cell imaging of intracellular calcium from primary sinonasal air‐liquid interface (ALI) cultures from 1 donor, and measure antimicrobial peptide release from 5 donors to demonstrate preliminary evidence suggesting that succinate can act as a stimulant of SCCs in the human sinonasal epithelium. Results: Results from scRNAseq analysis show that approximately 10% of the SCC/ionocyte cluster of cells expressed SUCNR1 as well as a small population of immune cells. Using live cell imaging of intracellular calcium, we also demonstrate that clusters of cells on primary sinonasal ALI cultures initiated calcium‐mediated signaling in response to succinate stimulation. Furthermore, we present evidence that primary sinonasal ALI cultures treated with succinate had increased levels of apical beta‐defensin 2, an antimicrobial peptide, compared to treatment with a control solution. Conclusion: Overall, these findings demonstrate the need for further investigation into the activation of the sinonasal epithelium by succinate in the pathogenesis of CRS. [ABSTRACT FROM AUTHOR]

AERD subjects demonstrated increased sensitivity to DB ( I p i < 0.01) and sucrose ( I p i < 0.01) compared with CRSsNP, while CRSsNP subjects demonstrated a reduced sensitivity to DB ( I p i < 0.05) and sucrose ( I p i < 0.05) compared with controls (Figure 1). It was anticipated that in AERD, unique genetic polymorphisms in DB-responsive T2Rs may result in upregulation of the receptors and resulting type-2 inflammation. Keywords: aspirin-exacerbated respiratory disease; bitter; chronic rhinosinusitis; gene; open array; sensory; taste EN aspirin-exacerbated respiratory disease bitter chronic rhinosinusitis gene open array sensory taste 269 272 4 02/21/23 20230301 NES 230301 INTRODUCTION Chronic rhinosinusitis (CRS), a disease of long-standing sinonasal inflammation, is divided into two phenotypes: CRS with and without nasal polyposis (CRSwNP, CRSsNP). [Extracted from the article]

CRSwNP can be further subcategorized into endotypes including aspirin-exacerbated respiratory disease (AERD), allergic fungal rhinosinusitis (AFRS), and, recently, central compartment atopic disease (CCAD) has been proposed as a novel endotype.2 There is a complex relationship between allergic rhinitis (AR) and CRS3; one potential link may be CCAD. Keywords: allergens; allergic rhinitis; chronic rhinosinusitis; skin prick testing EN allergens allergic rhinitis chronic rhinosinusitis skin prick testing 1299 1302 4 09/30/22 20221001 NES 221001 INTRODUCTION Chronic rhinosinusitis (CRS) is an inflammatory condition of the nose and paranasal sinuses that persists for greater than 12 weeks.1 CRS has traditionally been categorized based on the presence (CRSwNP) or absence (CRSsNP) of nasal polyps. There was no statistically significant difference in the inhalant allergen sensitization profiles of patients with AR and CCAD, except for a higher prevalence of weed allergy in the CCAD group, which barely reached statistical significance. [Extracted from the article]

Background: Cystic fibrosis (CF) chronic rhinosinusitis (CRS) has emerged as a distinct diagnostic entity, unique from other endotypes of CRS in its presentation, pathophysiology, diagnosis, treatment, and outcomes. As the sinonasal health of this patient population may have broad effects on pulmonary health and quality of life, a comprehensive understanding of the diagnostic and therapeutic approach to CF CRS is essential. In recognizing recent scientific advances and unique treatment modalities specific to this challenging patient population, in this review we systematically evaluate the scientific literature and provide an evidenced‐based review with recommendations (EBRR) for fundamental management principles of CF CRS. Methods: A systematic review of the literature was performed. Studies evaluating interventions for the management of CF CRS were included. An iterative review process was implemented in accordance with EBRR guidelines. A treatment recommendation was generated based on an assessment of the benefits, harms, and the overall grade of evidence. Results: We evaluated the published literature on 5 unique topics. Each of the following therapeutic categories was investigated explicitly for treatment outcomes in patients with CF CRS: (1) nasal saline; (2) intranasal corticosteroids (INCS); (3) topical antibiotics; (4) cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy; and (5) endoscopic sinus surgery (ESS). Conclusion: Based on the currently available evidence, nasal saline, ESS, and CFTR modulators are recommended in the management of CF CRS when appropriate. INCS and topical antibiotics are options. Clinical judgment and experience are essential in caring for patients with this uniquely challenging disorder. [ABSTRACT FROM AUTHOR]

We tracked patient SNOT-22 and ACT scores at the following time-points: post-FESS/pre-desensitization; 1 to 3 months post-desensitization; 4 to 6 months post-desensitization; 7 to 12 months post-desensitization; and 13 to 24 months post-desensitization. Values for age, daily prednisone dose, and pre-desensitization SNOT-22 were recorded after FESS and before aspirin treatment after aspirin desensitization. Keywords: chronic rhinosinusitis; endoscopic sinus surgery; eosinophilic rhinitis and nasal polyposis; FESS; SNOT-22 EN chronic rhinosinusitis endoscopic sinus surgery eosinophilic rhinitis and nasal polyposis FESS SNOT-22 872 875 4 05/17/22 20220601 NES 220601 Aspirin-exacerbated respiratory disease (AERD) is a chronic inflammatory condition characterized by the triad of eosinophilic asthma, chronic rhinosinusitis with nasal polyposis, and a non-IgE-mediated hypersensitivity to nonsteroidal anti-inflammatory drugs.1 The "gold standard" treatment of AERD consists of debulking of nasal polyps via complete functional endoscopic sinus surgery (FESS) of all 8 sinuses followed by aspirin treatment after aspirin desensitization (ATAD).2 The treatment protocol has been shown to lead to improved score on the 22-item Sino-Nasal Outcome Test (SNOT-22), decreased overall corticosteroid use, lower rate of revision surgery, and improved control of asthma.3,4 In this study, we seek to compare the outcomes of ATAD between men and women with AERD. [Extracted from the article]

Background: Chronic rhinosinusitis (CRS) is a multifactorial disease with a high co‐occurrence with asthma. In this multicohort study, we tested whether single nucleotide polymorphisms (SNPs) associated with childhood asthma and rhinovirus (RV)‐associated disease are related to an increased susceptibility to adult CRS in a multicohort retrospective case‐control study. Methods: Participants at two tertiary academic rhinology centers, University of Arizona (UofA) and University of Pennsylvania (UPenn) were recruited. Cases were defined as those with physician diagnosed CRS (UofA, n = 149; UPenn, n = 250), and healthy controls were those without CRS (UofA, n = 66; UPenn, n = 275). Genomic DNA was screened for the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP. Gene dosage, or the number of combined risk alleles in a single subject was calculated. Meta‐analysis of the association between GSDMB or CDHR3 genotypes and CRS was performed and additive gene dosage effect for each population calculated using p for trend. Results: A meta‐analysis revealed a combined increased risk for CRS in subjects with the GSDMB rs7216389 SNP (odds ratio [OR] 1.40; 95% confidence interval [CI], 1.16–1.76; p = 0.004). Both the UofA (OR 1.73; 95% CI, 1.23–2.43; p = 0.002) and UPenn (OR 1.27; 95% CI, 1.02–1.58; p = 0.035) populations showed a significant positive association between the number of combined risk alleles of GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP and risk for CRS. Conclusion: Carriers of the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP are at increased susceptibility for CRS. These data suggest that therapeutic approaches to target aberrant responses to RV infection may play a role in the treatment of unified airway disease. [ABSTRACT FROM AUTHOR]

Keywords: chronic rhinosinusitis; human leukocyte antigen; rhinosinusitis; sinusitis EN chronic rhinosinusitis human leukocyte antigen rhinosinusitis sinusitis 1075 1077 3 07/27/22 20220801 NES 220801 INTRODUCTION Chronic rhinosinusitis (CRS), an extremely common chronic condition, is defined as symptomatic and objective inflammation of the sinonasal mucosa lasting more than 12 weeks.1,2 Treatment for CRS remains a challenge despite our evolving understanding of the underlying mechanisms. RESULTS The 550 patients comprised 317 CRS patients (208 CRSwNP, 109 CRSsNP) and 233 controls (Table 1), all self-identified as white/Caucasian and middle-aged. In summary, we have determined that heterozygous carriers of the rs1391371 T allele are at significantly increased risk for developing CRSwNP, which further supports the potential contribution of this HLA region to CRS. [Extracted from the article]