COVID-19 vaccination and Guillain-Barré syndrome: analyses using the National Immunoglobulin Database.

Vaccination against viruses has rarely been associated with Guillain-Barré syndrome (GBS), and an association with the COVID-19 vaccine is unknown. We performed a population-based study of National Health Service data in England and a multicentre surveillance study from UK hospitals to investigate the relationship between COVID-19 vaccination and GBS. Firstly, case dates of GBS identified retrospectively in the National Immunoglobulin Database from 8 December 2021 to 8 July 2021 were linked to receipt dates of COVID-19 vaccines using data from the National Immunisation Management System in England. For the linked dataset, GBS cases temporally associated with vaccination within a 6-week risk window of any COVID-19 vaccine were identified. Secondly, we prospectively collected incident UK-wide (four nations) GBS cases from 1 January 2021 to 7 November 2021 in a separate UK multicentre surveillance database. For this multicentre UK-wide surveillance dataset, we explored phenotypes of reported GBS cases to identify features of COVID-19 vaccine-associated GBS. Nine hundred and ninety-six GBS cases were recorded in the National Immunoglobulin Database from January to October 2021. A spike of GBS cases above the 2016-2020 average occurred in March-April 2021. One hundred and ninety-eight GBS cases occurred within 6 weeks of the first-dose COVID-19 vaccination in England [0.618 cases per 100,000 vaccinations; 176 ChAdOx1 nCoV-19 (AstraZeneca), 21 tozinameran (Pfizer) and one mRNA-1273 (Moderna)]. The 6-week excess of GBS (compared to the baseline rate of GBS cases 6-12 weeks after vaccination) occurred with a peak at 24 days post-vaccination; first-doses of ChAdOx1 nCoV-19 accounted for the excess. No excess was seen for second-dose vaccination. The absolute number of excess GBS cases from January-July 2021 was between 98-140 cases for first-dose ChAdOx1 nCoV-19 vaccination. First-dose tozinameran and second-dose of any vaccination showed no excess GBS risk. Detailed clinical data from 121 GBS patients were reported in the separate multicentre surveillance dataset during this timeframe. No phenotypic or demographic differences identified between vaccine-associated and non-vaccinated GBS cases occurring in the same timeframe. Analysis of the linked NID/NIMS dataset suggested that first-dose ChAdOx1 nCoV-19 vaccination is associated with an excess GBS risk of 0.576 (95% confidence interval 0.481-0.691) cases per 100 000 doses. However, examination of a multicentre surveillance dataset suggested that no specific clinical features, including facial weakness, are associated with vaccination-related GBS compared to non-vaccinated cases. The pathogenic cause of the ChAdOx1 nCoV-19 specific first dose link warrants further study.

SARS-CoV-2 induces double-stranded RNA-mediated innate immune responses in respiratory epithelial-derived cells and cardiomyocytes.

Coronaviruses are adept at evading host antiviral pathways induced by viral double-stranded RNA, including interferon (IFN) signaling, oligoadenylate synthetase-ribonuclease L (OAS-RNase L), and protein kinase R (PKR). While dysregulated or inadequate IFN responses have been associated with severe coronavirus infection, the extent to which the recently emerged SARS-CoV-2 activates or antagonizes these pathways is relatively unknown. We found that SARS-CoV-2 infects patient-derived nasal epithelial cells, present at the initial site of infection; induced pluripotent stem cell-derived alveolar type 2 cells (iAT2), the major cell type infected in the lung; and cardiomyocytes (iCM), consistent with cardiovascular consequences of COVID-19 disease. Robust activation of IFN or OAS-RNase L is not observed in these cell types, whereas PKR activation is evident in iAT2 and iCM. In SARS-CoV-2-infected Calu-3 and A549ACE2 lung-derived cell lines, IFN induction remains relatively weak; however, activation of OAS-RNase L and PKR is observed. This is in contrast to Middle East respiratory syndrome (MERS)-CoV, which effectively inhibits IFN signaling and OAS-RNase L and PKR pathways, but is similar to mutant MERS-CoV lacking innate immune antagonists. Remarkably, OAS-RNase L and PKR are activated in MAVS knockout A549ACE2 cells, demonstrating that SARS-CoV-2 can induce these host antiviral pathways despite minimal IFN production. Moreover, increased replication and cytopathic effect in RNASEL knockout A549ACE2 cells implicates OAS-RNase L in restricting SARS-CoV-2. Finally, while SARS-CoV-2 fails to antagonize these host defense pathways, which contrasts with other coronaviruses, the IFN signaling response is generally weak. These host-virus interactions may contribute to the unique pathogenesis of SARS-CoV-2.

Chronic rhinosinusitis risk after maxillectomy with microvascular reconstruction.

Objectives Chronic rhinosinusitis (CRS) can be associated with tumors involving the maxillary sinus, but outcomes after undergoing maxillectomy with free flap reconstruction remain unclear. Methods A retrospective analysis of medical records was performed to evaluate evidence of CRS in patients who underwent maxillectomy with free flap reconstruction at a single tertiary care academic institution from 2013 through 2020. Results Eighty-four patients were assessed. Nineteen (22.6%) patients were diagnosed with CRS after surgery, 23 (27.4%) patients were treated for sinus symptoms, and 49 (58.3%) had radiographic evidence of sinus inflammation for more than 6 months. Risk factors for requiring sinus treatment included adjuvant or neoadjuvant chemotherapy (p=0.002) and pre-operative use of sinus medication (p<0.001). Radiographic evidence of sinusitis 6 months after surgery is also closely associated with sinusitis treatment (p=0.051). Conclusions CRS may be underdiagnosed in patients undergoing maxillectomy with microvascular reconstruction. Further evaluation into patient sinus disease and symptoms following neoplastic surgery may lead to a higher quality of life in some long-term survivors.

Image guided dilation of sinus ostium in revision sinus surgery.

PURPOSE: Assess if a rigid, image-guided balloon could be used effectively and safely in revision sinus surgery. MATERIALS AND METHODS: A prospective, non-randomized, single-arm, multicenter study to assess the safety and device performance of the NuVent™ EM Balloon Sinus Dilation System. Adults with CRS in need of revision sinus surgery were enrolled for balloon sinus dilation of a frontal, sphenoid, or maxillary sinus. The primary device performance endpoint was the ability of the device to (1) navigate to; and (2) dilate tissue in subjects with scarred, granulated, or previously surgically-altered tissue (revision). Safety outcomes included the assessment of any operative adverse events (AEs) directly attributable to the device or for which direct cause could not be determined. A follow-up endoscopy was conducted at 14 days post-treatment for assessment of any AEs. Performance outcomes included the surgeon's ability to reach the target sinus (es) and dilate the ostia. Endoscopic photos were captured for each treated sinus pre- and post-dilation. RESULTS: At 6 US clinical sites, 51 subjects were enrolled; 1 subject withdrew before treatment due to a cardiac complication from anesthesia. 121 sinuses were treated in 50 subjects. The device performed as expected in 100 % of the 121 treated sinuses, with investigators able to navigate to the treatment area and dilate the sinus ostium without difficulty. Ten AEs were seen in 9 subjects, with 0 related to the device. CONCLUSION: The targeted frontal, maxillary or sphenoid sinus ostium were safely dilated in every revision subject treated, with no AEs directly attributed to the device.

Frailty does not worsen postoperative outcomes in sinonasal squamous cell carcinoma.

PURPOSE: Sinonasal squamous cell carcinoma (SCC) is an aggressive malignancy frequently requiring surgical resection and adjuvant treatment. Frailty is a metric that attempts to estimate a patient's ability to tolerate the physiologic stress of treatment. There is limited work describing frailty in patients with sinonasal cancer. We sought to determine the impact of frailty on postoperative outcomes in patients undergoing treatment for sinonasal SCC. MATERIALS AND METHODS: Cases of patients undergoing surgical resection of sinonasal SCC at two tertiary medical centers were queried. Demographic, treatment, and survival data were recorded. Frailty was calculated using validated indexes, including the American Society of Anesthesiologists (ASA) classification, modified 5-item frailty index (mFI-5), and the Charlson Comorbidity Index (CCI). Primary outcomes included medical and surgical complications, readmission, and length of stay (LOS). RESULTS: 38 patients were included. There were 23 (60.5 %) men and 15 (39.5 %) women with an average age of 59.6 ± 12.1 years. MFI-5 was 0.76 ± 0.54 and CCI was 5.71 ± 2.64. No significant association was noted between frailty measures and postoperative outcomes including 30-day medical complications, 30-day surgical complications, any 30-day complication, and readmission. Increased ASA was noted to be predictive of increased length of stay (Incidence Rate Ratio: 1.80, 95 % confidence interval [CI]: 1.16-2.83, p = 0.009). CONCLUSIONS: We found no association between frailty metrics and worsening surgical or medical postoperative outcomes. This suggests that frailty metrics may not be as relevant for sinonasal surgery even for advanced pathologies, given the more limited physiologic impact of minimally invasive surgery.

Optimizing Perioperative Care in Transsphenoidal Pituitary Surgery: Considerations for Enhanced Recovery After Surgery.

OBJECTIVE: To identify key recommendations for maximizing the efficiency and efficacy of perioperative care in transsphenoidal pituitary surgery. METHODS: The authors performed a comprehensive literature search of Enhanced Recovery After Surgery protocols implemented for patients undergoing transsphenoidal adenomectomy (TSA); individual recommendations were abstracted, and the evidence base thoroughly reviewed. RESULTS: The authors identified 19 individual recommendations pertinent to the care of patients undergoing TSA, which were subdivided into preoperative (n=6), intraoperative (n=6), and postoperative (n=7) interventions. Key factors recommended for minimizing length of stay, preventing readmission, and improving patient outcomes included comprehensive patient education, multidisciplinary evaluation, avoidance of routine lumbar drain placement and nasal packing, and rigorous postoperative monitoring of pituitary function and salt-water imbalances. The overall level of evidence for 7/19 (37%) implemented recommendations was found to be low, suggesting a need for continued research in this patient population. CONCLUSION: Several key interventions should be considered in the development of Enhanced Recovery After Surgery protocols for TSA, which may aid in further decreasing length of stay and promoting positive patient outcomes.

A Novel, Orally Bioavailable, Small-Molecule Inhibitor of PCSK9 With Significant Cholesterol-Lowering Properties In Vivo.

Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibits the clearance of low-density lipoprotein (LDL) cholesterol (LDL-C) from plasma by directly binding with the LDL receptor (LDLR) and sending the receptor for lysosomal degradation. As the interaction promotes elevated plasma LDL-C levels, and therefore a predisposition to cardiovascular disease, PCSK9 has attracted intense interest as a therapeutic target. Despite this interest, an orally bioavailable small-molecule inhibitor of PCSK9 with extensive lipid-lowering activity is yet to enter the clinic. We report herein the discovery of NYX-PCSK9i, an orally bioavailable small-molecule inhibitor of PCSK9 with significant cholesterol-lowering activity in hyperlipidemic APOE∗3-Leiden.CETP mice. NYX-PCSK9i emerged from a medicinal chemistry campaign demonstrating potent disruption of the PCSK9-LDLR interaction in vitro and functional protection of the LDLR of human lymphocytes from PCSK9-directed degradation ex vivo. APOE∗3-Leiden.CETP mice orally treated with NYX-PCSK9i demonstrated a dose-dependent decrease in plasma total cholesterol of up to 57%, while its combination with atorvastatin additively suppressed plasma total cholesterol levels. Importantly, the majority of cholesterol lowering by NYX-PCSK9i was in non-HDL fractions. A concomitant increase in total plasma PCSK9 levels and significant increase in hepatic LDLR protein expression strongly indicated on-target function by NYX-PCSK9i. Determinations of hepatic lipid and fecal cholesterol content demonstrated depletion of liver cholesteryl esters and promotion of fecal cholesterol elimination with NYX-PCSK9i treatment. All measured in vivo biomarkers of health indicate that NYX-PCSK9i has a good safety profile. NYX-PCSK9i is a potential new therapy for hypercholesterolemia with the capacity to further enhance the lipid-lowering activities of statins.

Polarization of protease-activated receptor 2 (PAR-2) signaling is altered during airway epithelial remodeling and deciliation.

Protease-activated receptor 2 (PAR-2) is activated by secreted proteases from immune cells or fungi. PAR-2 is normally expressed basolaterally in differentiated nasal ciliated cells. We hypothesized that epithelial remodeling during diseases characterized by cilial loss and squamous metaplasia may alter PAR-2 polarization. Here, using a fluorescent arrestin assay, we confirmed that the common fungal airway pathogen Aspergillus fumigatus activates heterologously-expressed PAR-2. Endogenous PAR-2 activation in submerged airway RPMI 2650 or NCI-H520 squamous cells increased intracellular calcium levels and granulocyte macrophage-colony-stimulating factor, tumor necrosis factor α, and interleukin (IL)-6 secretion. RPMI 2650 cells cultured at an air-liquid interface (ALI) responded to apically or basolaterally applied PAR-2 agonists. However, well-differentiated primary nasal epithelial ALIs responded only to basolateral PAR-2 stimulation, indicated by calcium elevation, increased cilia beat frequency, and increased fluid and cytokine secretion. We exposed primary cells to disease-related modifiers that alter epithelial morphology, including IL-13, cigarette smoke condensate, and retinoic acid deficiency, at concentrations and times that altered epithelial morphology without causing breakdown of the epithelial barrier to model early disease states. These altered primary cultures responded to both apical and basolateral PAR-2 stimulation. Imaging nasal polyps and control middle turbinate explants, we found that nasal polyps, but not turbinates, exhibit apical calcium responses to PAR-2 stimulation. However, isolated ciliated cells from both polyps and turbinates maintained basolateral PAR-2 polarization, suggesting that the calcium responses originated from nonciliated cells. Altered PAR-2 polarization in disease-remodeled epithelia may enhance apical responses and increase sensitivity to inhaled proteases.

PAR-2-activated secretion by airway gland serous cells: role for CFTR and inhibition by Pseudomonas aeruginosa.

Airway submucosal gland serous cells are important sites of fluid secretion in conducting airways. Serous cells also express the cystic fibrosis (CF) transmembrane conductance regulator (CFTR). Protease-activated receptor 2 (PAR-2) is a G protein-coupled receptor that activates secretion from intact airway glands. We tested if and how human nasal serous cells secrete fluid in response to PAR-2 stimulation using Ca2+ imaging and simultaneous differential interference contrast imaging to track isosmotic cell shrinking and swelling reflecting activation of solute efflux and influx pathways, respectively. During stimulation of PAR-2, serous cells exhibited dose-dependent increases in intracellular Ca2+. At stimulation levels >EC50 for Ca2+, serous cells simultaneously shrank ∼20% over ∼90 s due to KCl efflux reflecting Ca2+-activated Cl- channel (CaCC, likely TMEM16A)-dependent secretion. At lower levels of PAR-2 stimulation (

Small-molecule Akt-activation in airway cells induces NO production and reduces IL-8 transcription through Nrf-2.

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.

Bitter taste receptor agonists regulate epithelial two-pore potassium channels via cAMP signaling.

BACKGROUND: Epithelial solitary chemosensory cell (tuft cell) bitter taste signal transduction occurs through G protein coupled receptors and calcium-dependent signaling pathways. Type II taste cells, which utilize the same bitter taste signal transduction pathways, may also utilize cyclic adenosine monophosphate (cAMP) as an independent signaling messenger in addition to calcium. METHODS: In this work we utilized specific pharmacologic inhibitors to interrogate the short circuit current (Isc) of polarized nasal epithelial cells mounted in Ussing chambers to assess the electrophysiologic changes associated with bitter agonist (denatonium) treatment. We also assessed release of human ß-defensin-2 from polarized nasal epithelial cultures following treatment with denatonium benzoate and/or potassium channel inhibitors. RESULTS: We demonstrate that the bitter taste receptor agonist, denatonium, decreases human respiratory epithelial two-pore potassium (K2P) current in polarized nasal epithelial cells mounted in Ussing chambers. Our data further suggest that this occurs via a cAMP-dependent signaling pathway. We also demonstrate that this decrease in potassium current lowers the threshold for denatonium to stimulate human ß-defensin-2 release. CONCLUSIONS: These data thus demonstrate that, in addition to taste transducing calcium-dependent signaling, bitter taste receptor agonists can also activate cAMP-dependent respiratory epithelial signaling pathways to modulate K2P currents. Bitter-agonist regulation of potassium currents may therefore serve as a means of rapid regional epithelial signaling, and further study of these pathways may provide new insights into regulation of mucosal ionic composition and innate mechanisms of epithelial defense.

The Hospital Frailty Risk Score-outcomes in specialised services.

BACKGROUND: Frailty is increasingly used to risk stratify older people, but across specialised services there is no standardised approach. The aim of this study was to assess if the Hospital Frailty Risk Score (HFRS) could describe outcomes for older people within English specialised services. DESIGN: A retrospective cohort study was performed using the Secondary Uses Service (SUS) electronic database for people aged 75 or older admitted between April 2017 and March 2018. METHODS: Based on HFRS, the populations were risk stratified into mild, moderate and severe frailty risk. The relationships with length of stay, readmission rate, mortality and some selected condition specific treatment complications were quantified using descriptive statistics. RESULTS: Very few individuals (<2%) could not be risk stratified for frailty risk. Frailty was differentially distributed across the specialties; around one-third had mild frailty; another third had moderate frailty and one-quarter severe frailty. Increasing frailty risk was associated with increased length of stay for the index admission, more days in hospital in the year following intervention and increased risk of dying in hospital. Severe frailty was a powerful discriminator of the risk of death; between 25 and 40% of those with severe frailty risk died at 30 months across all specialties. CONCLUSIONS: This study demonstrates the first application of the HFRS to a national dataset to describe service outcomes and mortality for older people undergoing a range of specialised interventions. This information could be used to identify those that might benefit from holistic assessment, aid prognostication, commissioning and service planning.

Effectiveness of endoscopic sinus surgery and aspirin therapy in the management of aspirin-exacerbated respiratory disease.

Background: Aspirin therapy and/or type 2 (T2) biologics are used in the management of aspirin-exacerbated respiratory disease (AERD). Objective: To identify the number of patients with AERD who tolerated aspirin therapy, yet due to persistent symptoms, incorporated T2 biologic management. Methods: A retrospective review was performed between July 2016 and June 2019. Patients with AERD and who underwent endoscopic sinus surgery (ESS), aspirin desensitization (AD), and at least 6 months of aspirin therapy (ATAD) after AD, and who remained biologic-naive up through this timepoint were included in the study. Introduction of a T2 biologic while on ATAD was the primary outcome. The secondary outcome was a change in a validated patient-reported outcome measure for chronic rhinosinusitis score between the postoperative predesensitization timepoint, and the 6-month postdesensitization timepoint, presented as means and compared by using the Student's t-test. Results: A total of 103 patients met inclusion criteria. Two patients (1.9%) ultimately supplemented ATAD with a T2 biologic. The mean outcomes measure test score after 6 months of ATAD for patients who received biologics was 40.5 versus 15 in those who did not receive biologics (p = 0.02). The mean differences between the postoperative predesensitization test score and the 6-month postdesensitization test score for patients who went on to receive biologics was an increase of 13 versus a decrease of 10 for those patients who did not receive biologics (p = 0.12). Conclusion: ESS, coupled with AD and ATAD, was successful in the long-term management of the majority of the patients with AERD, which rarely required the incorporation of T2 biologics. Patient questionnaires, such as outcomes measure test score, may identify aspirin therapy failures and help guide the practitioner in deciding when to introduce T2 biologics into the patient's treatment regimen.

Pre-intervention SNOT-22 scores predict outcomes in aspirin exacerbated respiratory disease.

PURPOSE: This study evaluated whether stratified preoperative, pre- aspirin desensitization (AD) sinonasal symptom scores predict postoperative, post-AD outcomes in Aspirin exacerbated respiratory disease (AERD). MATERIALS AND METHODS: Retrospective chart review of patients with aspirin challenge-proven AERD who underwent endoscopic sinus surgery followed by AD was performed. Preoperative, postoperative/pre-AD, and postoperative/post-AD sinonasal symptom scores were collected (22-item Sino-Nasal Outcomes Test, SNOT-22). A longitudinal linear mixed-effects model was used for data analysis. RESULTS: Forty-seven patients (59.6% female) aged 48.0 ± 13.2 were included. Average time from surgery to AD was 70.0 ± 52.8 days. Preoperative SNOT-22 scores (n = 47) were divided into tertiles (cutoffs of 36 and 54 indicating mild [22.5 ± 13.7], moderate [44.3 ± 12.2], and severe [72.9 ± 19.7] disease). This corresponded to 12 (25.5%), 18 (38.3%), and 17 (36.2%) subjects being categorized into mild, moderate, and severe tertiles, respectively. Postoperative, pre-AD SNOT-22 in all disease groups decreased and were not significantly different (12.3 ± 13.7, 11.1 ± 12.2, 22.7 ± 19.7; p = 0.074). At short-term post-AD, only the severe group worsened (35.0 ± 20.3, p < 0.001), whereas other groups demonstrated negligible change (9.3 ± 14.3 and 14.4 ± 12.2). At long-term post-AD, all groups redemonstrated convergence in symptom scores (23.7 ± 20.9, 19.4 ± 15.4, and 31.0 ± 27.6, p = 0.304). CONCLUSION: Preoperative SNOT-22 scores may be used as a predictor of postoperative, post-AD patient-reported outcomes in AERD. Patients with mild and moderate disease may derive benefit from surgery and AD alone, while those with severe disease may require additional interventions (e.g., biologics).

Neuropeptide regulation of secretion and inflammation in human airway gland serous cells.

Airway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways. To elucidate how neuropeptides regulate serous cells, we tested if human nasal turbinate serous cells secrete bicarbonate (HCO3 -), important for mucus polymerisation and antimicrobial peptide function, during stimulation with cAMP-elevating vasoactive intestinal peptide (VIP) and if this requires CFTR. Serous cells stimulated with VIP exhibited a ∼15-20% cAMP-dependent decrease in cell volume and a ∼0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl- and HCO3 - secretion, respectively. HCO3 - secretion was directly dependent on CFTR and was absent in cells from CF patients. In contrast, neuropeptide Y (NPY) reduced VIP-evoked cAMP increases, CFTR activation, and Cl-/HCO3 - secretion. Culture of primary serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3 - secretion. Moreover, VIP enhanced antimicrobial peptide secretion and antimicrobial efficacy of secretions while NPY reduced antimicrobial efficacy. In contrast, NPY enhanced cytokine release while VIP reduced cytokine release through a mechanism requiring CFTR. As levels of VIP and NPY are up-regulated in diseases like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control mucus rheology and inflammatory responses in serous cells. Furthermore, the loss of CFTR conductance in serous cells may contribute to CF pathophysiology by increasing serous cells inflammatory responses in addition to directly impairing Cl- and HCO3 - secretion.

Heteroarylureas with fused bicyclic diamine cores as inhibitors of fatty acid amide hydrolase.

A series of mechanism-based heteroaryl urea fatty acid amide hydrolase (FAAH) inhibitors with fused bicyclic diamine cores is described. In contrast to compounds built around a piperazine core, most of the fused bicyclic diamine bearing analogs prepared exhibited greater potency against rFAAH than the human enzyme. Several compounds equipotent against both species were identified and profiled in vivo.

A small molecule inhibitor of PCSK9 that antagonizes LDL receptor binding via interaction with a cryptic PCSK9 binding groove.

Proprotein convertase (PC) subtilisin kexin type 9 (PCSK9) inhibits the clearance of low density lipoprotein (LDL) cholesterol from plasma by directly interacting with the LDL receptor (LDLR). As the interaction promotes elevated plasma LDL cholesterol levels and a predisposition to cardiovascular disease (CVD), it has attracted much interest as a therapeutic target. While anti-PCSK9 monoclonal antibodies have been successful in the treatment of hypercholesteremia by decreasing CVD risk, their high cost and a requirement for injection have prohibited widespread use. The advent of an orally bioavailable small molecule inhibitor of the PCSK9-LDLR interaction is an attractive alternative, however efforts have been tempered as the binding interface is unfavourable for binding by small organic molecules. Despite its challenging nature, we report herein the discovery of compound 3f as a small molecule inhibitor of PCSK9. The kinase inhibitor nilotinib emerged from a computational screen that was applied to identify compounds that may bind to a cryptic groove within PCSK9 and proximal to the LDLR-binding interface. A subsequent in vitro PCSK9-LDLR binding assay established that nilotinib was a bona fide but modest inhibitor of the interaction (IC50 = 9.8 µM). Through multiple rounds of medicinal chemistry, 3f emerged as a lead-like molecule by demonstrating disruption of the PCSK9-LDLR interaction at nanomolar levels in vitro (IC50 = 537 nM) with no inhibitory activity (IC50 > 10 µM) against a small panel of kinases. Compound 3f restored LDL uptake by liver cells at sub-micromolar levels and demonstrated excellent bioavailability when delivered subcutaneously in mice. Most significantly, compound 3f lowered total cholesterol levels in the plasma of wild-type mice, thereby providing proof-of-concept that the notion of a small molecule inhibitor against PCSK9 is therapeutically viable.

Activation of airway epithelial bitter taste receptors by Pseudomonas aeruginosa quinolones modulates calcium, cyclic-AMP, and nitric oxide signaling.

Bitter taste receptors (taste family 2 bitter receptor proteins; T2Rs), discovered in many tissues outside the tongue, have recently become potential therapeutic targets. We have shown previously that airway epithelial cells express several T2Rs that activate innate immune responses that may be important for treatment of airway diseases such as chronic rhinosinusitis. It is imperative to more clearly understand what compounds activate airway T2Rs as well as their full range of functions. T2R isoforms in airway motile cilia (T2R4, -14, -16, and -38) produce bactericidal levels of nitric oxide (NO) that also increase ciliary beating, promoting clearance of mucus and trapped pathogens. Bacterial quorum-sensing acyl-homoserine lactones activate T2Rs and stimulate these responses in primary airway cells. Quinolones are another type of quorum-sensing molecule used by Pseudomonas aeruginosa To elucidate whether bacterial quinolones activate airway T2Rs, we analyzed calcium, cAMP, and NO dynamics using a combination of fluorescent indicator dyes and FRET-based protein biosensors. T2R-transfected HEK293T cells, several lung epithelial cell lines, and primary sinonasal cells grown and differentiated at the air-liquid interface were tested with 2-heptyl-3-hydroxy-4-quinolone (known as Pseudomonas quinolone signal; PQS), 2,4-dihydroxyquinolone, and 4-hydroxy-2-heptylquinolone (HHQ). In HEK293T cells, PQS activated T2R4, -16, and -38, whereas HHQ activated T2R14. 2,4-Dihydroxyquinolone had no effect. PQS and HHQ increased calcium and decreased both baseline and stimulated cAMP levels in cultured and primary airway cells. In primary cells, PQS and HHQ activated levels of NO synthesis previously shown to be bactericidal. This study suggests that airway T2R-mediated immune responses are activated by bacterial quinolones as well as acyl-homoserine lactones.

Tissue-Dependent Expression of Bitter Receptor TAS2R38 mRNA.

TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active forms of this receptor is nearly equal in many human populations, and heterozygotes with 1 copy of the active form and 1 copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We, therefore, wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high expressers in nasal tissue. To that end, we measured gene expression by quantitative PCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissue pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein.