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Akt is an important kinase in metabolism. Akt also phosphorylates and activates endothelial and neuronal nitric oxide (NO) synthases (eNOS and nNOS, respectively) expressed in M0 (unpolarized) macrophages. We showed that e/nNOS NO production downstream of bitter taste receptors enhances macrophage phagocytosis. In airway epithelial cells, we also showed that the activation of Akt by a small molecule (SC79) enhances NO production and increases levels of nuclear Nrf2, which reduces IL-8 transcription during concomitant stimulation with Toll-like receptor (TLR) 5 agonist flagellin. We hypothesized that SC79's production of NO in macrophages might likewise enhance phagocytosis and reduce the transcription of some pro-inflammatory cytokines. Using live cell imaging of fluorescent biosensors and indicator dyes, we found that SC79 induces Akt activation, NO production, and downstream cGMP production in primary human M0 macrophages. This was accompanied by a reduction in IL-6, IL-8, and IL-12 production during concomitant stimulation with bacterial lipopolysaccharide, an agonist of pattern recognition receptors including TLR4. Pharmacological inhibitors suggested that this effect was dependent on Akt and Nrf2. Together, these data suggest that several macrophage immune pathways are regulated by SC79 via Akt. A small-molecule Akt activator may be useful in some infection settings, warranting future in vivo studies. [ABSTRACT FROM AUTHOR]

Bitter taste receptors (T2Rs) are G protein-coupled receptors (GPCRs) expressed in various cell types including ciliated airway epithelial cells and macrophages. T2Rs in these two innate immune cell types are activated by bitter products, including those secreted by Pseudomonas aeruginosa, leading to Ca2+-dependent activation of endothelial nitric oxide (NO) synthase (eNOS). NO enhances mucociliary clearance and has direct antibacterial effects in ciliated epithelial cells. NO also increases phagocytosis by macrophages. Using biochemistry and live-cell imaging, we explored the role of heat shock protein 90 (HSP90) in regulating T2R-dependent NO pathways in primary sinonasal epithelial cells, primary monocyte-derived macrophages, and a human bronchiolar cell line (H441). Immunofluorescence showed that H441 cells express eNOS and T2Rs and that the bitter agonist denatonium benzoate activates NO production in a Ca2+- and HSP90-dependent manner in cells grown either as submerged cultures or at the air–liquid interface. In primary sinonasal epithelial cells, we determined that HSP90 inhibition reduces T2R-stimulated NO production and ciliary beating, which likely limits pathogen clearance. In primary monocyte-derived macrophages, we found that HSP-90 is integral to T2R-stimulated NO production and phagocytosis of FITC-labeled Escherichia coli and pHrodo-Staphylococcus aureus. Our study demonstrates that HSP90 serves as an innate immune modulator by regulating NO production downstream of T2R signaling by augmenting eNOS activation without impairing upstream Ca2+ signaling. These findings suggest that HSP90 plays an important role in airway antibacterial innate immunity and may be an important target in airway diseases such as chronic rhinosinusitis, asthma, or cystic fibrosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Inverted papillomas are benign sinonasal tumors that can recur or become cancerous. The mainstay of treatment is surgical resection. We summarize the biology of inverted papillomas and review surgical outcomes in an effort to define the current treatment strategy. Inverted papillomas (IP) are the most common sinonasal tumor with a tendency for recurrence, potential attachment to the orbit and skull base, and risk of malignant degeneration into squamous cell carcinoma (SCC). While the overall rate of recurrence has decreased with the widespread adoption of high-definition endoscopic optics and advanced surgical tools, there remain challenges in managing tumors that are multiply recurrent or involve vital neurovascular structures. Here, we review the state-of-the-art diagnostic tools for IP and IP-degenerated SCC, contemporary surgical management, and propose a surveillance protocol. [ABSTRACT FROM AUTHOR]

Background: The non-cancerous functions of Akt in the airway are understudied. In some tissues, Akt phosphorylates and activates endothelial nitric oxide synthase (eNOS) to produce nitric oxide (NO) that has anti-inflammatory effects. NO production has antibacterial and antiviral effects in the airway, and increasing NO may be a useful anti-pathogen strategy. Akt also stimulates the nuclear factor erythroid 2-related factor 2 (Nrf-2) transcription factor, which transcribes antioxidant genes. Therefore, we hypothesized that activation of the Akt/eNOS pathway, which also activates Nrf-2, may have protective effects in human airway cells against injury.Methods: To directly test the effects of Akt signaling in the airway, we treated A549 and 16HBE cells as well as primary bronchial, nasal, and type II alveolar epithelial cells with small molecule Akt activator SC79. We examined the effects of SC79 on eNOS activation, NO production, Nrf-2 target levels, and interleukin-8 (IL-8) transcription during exposure to TNF-α or Pseudomonas flagellin (TLR5 agonist). Additionally, air-liquid interface bronchial cultures were treated with cadmium, an oxidative stressor that causes airway barrier breakdown.Results: SC79 induced a ~ twofold induction of p-eNOS and Nrf-2 protein levels blocked by PI3K inhibitor LY294002. Live cell imaging revealed SC79 increased acute NO production. Quantitative RT-PCR showed a ~ twofold increase in Nrf-2 target gene transcription. TNF-α or flagellin-induced IL-8 levels were also significantly reduced with SC79 treatment. Moreover, the transepithelial electrical resistance decrease observed with cadmium was ameliorated by SC79, likely by an acute increase in tight junction protein ZO-1 levels.Conclusions: Together, the data presented here demonstrate SC79 activation of Akt induces potentially anti-pathogenic NO production, antioxidant gene transcription, reduces IL-8 transcription, and may protect against oxidative barrier dysfunction in a wide range of airway epithelial cells. [ABSTRACT FROM AUTHOR]

Objectives Although adjuvant radiotherapy may be indicated in patients with sinonasal squamous cell carcinoma (SNSCC) following primary surgery, some patients choose to forgo recommended postoperative radiation therapy (PORT). This study aimed to elucidate factors associated with patient refusal of recommended PORT in SNSCC and examine overall survival. Methods Retrospective analysis of patients with SNSCC treated with primary surgery from the National Cancer Database diagnosed between 2004 and 2016. A multivariable logistic regression model was created to determine the association between clinical or demographic covariates and likelihood of PORT refusal. Unadjusted Kaplan–Meier estimates, log-rank tests, and a multivariable Cox proportional hazard model were used to assess overall survival. Results A total of 2,231 patients were included in the final analysis, of which 1,456 (65.3%) were males and 73 (3.3%) refused recommended PORT. Patients older than 74 years old were more likely to refuse PORT than those younger than 54 (odds ratio [OR] 3.43, 95% confidence interval [CI]: 1.84–6.62). Median survival among the entire cohort, those who received recommended PORT, and those who refused PORT was 83.0 months (95% CI: 74.6–97.1), 83.0 months (95% CI: 74.9–98.2), and 63.6 months (95% CI: 37.3–101.4), respectively. Refusal of PORT was not associated with overall survival (hazard ratio: 0.99, 95% CI: 0.69–1.42). Conclusions PORT refusal in patients with SNSCC is rare and was found to be associated with several patient factors. The decision to forgo PORT is not independently associated with overall survival in this cohort. Further study is required to determine the clinical implications of these findings as the treatment decisions are complex. [ABSTRACT FROM AUTHOR]

Objective  This study aimed to provide information regarding the prognosis of patients presenting with metastatic anterior skull base malignancies based upon histology and site of distant metastasis (DM). Patients and Methods  The National Cancer Database was queried for patients with anterior skull base malignant neoplasms with DM. Outcomes  Prognosis was compared between site of DM and tumor histologies. A multivariable Cox proportional hazards model was used to identify prognostic factors for overall survival (OS). Results  A total of 481 patients were identified. Lung was the most common site of DM (24.9%), followed by bone (22.2%), liver (5.6%), and brain (2.5%). Lung was the most common site for squamous cell carcinoma (SCCa) (28.3%), melanoma (37.7%), and adenoid cystic carcinoma (ACC; 31.4%). The median survival for patients presenting with metastatic disease regardless of tumor histology was 9.0 months (95% confidence interval [CI]: 8.2–10.3), and patients with metastasis to the liver had the best median survival at 15.5 months (95% CI: 10.5–25.6). The median survivals for the most common histologies, SCCa, melanoma, and ACC were 8.2 months (95% CI: 5.5–10.2), 10.5 months (95% CI: 8.7–14.1), and 15.0 months (95% CI: 11.1–61.1), respectively. Multivariable analysis demonstrated worse overall survival (OS) for older patients, higher Charlson-Deyo comorbidity scores, and tumors with higher grade and T stage. Compared with metastasis to bone, lung metastasis had better OS on multivariable analysis (hazard ratio [HR]: 0.70, 95% CI: 0.51–97). Adenoid cystic carcinoma had improved OS compared with SCCa (HR: 0.62, 95% CI: 0.39–99). Conclusion  Tumor histology, metastatic sites, and several disease factors affected prognosis in anterior skull base malignancies with DM. [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]