Nasal Epithelium Research Articles

The Impact of NO2 on Epithelial Barrier Integrity of a Primary Cell-Based Air-Liquid Interface Model of the Nasal Respiratory Epithelium.

Nitrogen dioxide (NO2) is a pervasive gaseous air pollutant with well-documented hazardous effects on health, necessitating precise toxicological characterization. While prior research has primarily focused on lower airway structures, the upper airways, serving as the first line of defense against airborne substances, remain understudied. This study aimed to investigate the functional effects of NO2 exposure alone or in combination with hypoxia as a secondary stimulus on nasal epithelium and elucidate its molecular mechanisms because hypoxia is considered a pathophysiological factor in the onset and persistence of chronic rhinosinusitis, a disease of the upper airways. Air-liquid interface cell cultures derived from primary nasal mucosa cells were utilized as an invitro model, offering a high invitro-in vivo correlation. Our findings demonstrate that NO2 exposure induces malfunction of the epithelial barrier, as evidenced by decreased transepithelial electrical resistance and increased fluorescein isothiocyanate (FITC)-dextran permeability. mRNA expression analysis revealed a significant increase in IL-6 and IL-8 expressions following NO2. Reduced mRNA expression of the tight junction component occludin was identified as a structural correlate of the damaged epithelial barrier. Notably, hypoxic conditions alone did not alter epithelial barrier integrity. These findings provide information on the harmful effects of NO2 exposure on the human nasal epithelium, including compromised barrier integrity and induction of inflammatory responses. Overall, this study contributes to our understanding of pathophysiological mechanisms underlying also upper airway respiratory diseases associated with air pollution exposure and emphasizes the importance of mitigating NO2 emissions to safeguard respiratory health.

Prostaglandin E Receptor 2 (EP2) Dysregulation in Allergic Fungal Rhinosinusitis Nasal Polyp Epithelium.

Allergic fungal rhinosinusitis (AFRS) is an eosinophilic subtype of chronic rhinosinusitis with nasal polyposis (CRSwNP). This study aimed to investigate the transcriptome of AFRS nasal polyp epithelium. Sinonasal epithelial cells were harvested from healthy nasal mucosa and polyp tissue collected from participants undergoing elective sinonasal surgery. Primary epithelial cells were subsequently grown in air/liquid interface and subjected to RNA-seq analysis, RT-qPCR, immunoblotting, and immunostaining. A total of 19 genes were differentially expressed between healthy and AFRS sample epithelium. The second top candidate gene, ranked by adjusted p-value, was prostaglandin E receptor 2 (PTGER2). The upregulation of PTGER2 was confirmed by RT-qPCR and immunoblot. The presence of the EP2 receptor, encoded by the PTGER2 gene, was confirmed by immunocytochemistry. PTGER2 is a potential novel therapeutic target for AFRS. EP2 dysregulation is associated with aspirin-exacerbated respiratory disease, potentially giving insight into common mechanisms of disease in severe CRSwNP. NA Laryngoscope, 2024.

Olfactory and trigeminal routes of HSV-1 CNS infection with regional microglial heterogeneity.

Herpes simplex virus type 1 (HSV-1) primarily targets the oral and nasal epithelia before establishing latency in the trigeminal ganglion (TG) and other peripheral ganglia. HSV-1 can also infect and become latent in the central nervous system (CNS) independent of latency in the TGs. Recent studies suggest entry to the CNS via two distinct routes: the TG-brainstem connection and olfactory nerve; however, to date, there is no characterization of brain regions targeted during HSV-1 primary infection. Furthermore, the immune response by microglia may also contribute to the heterogeneity between different brain regions. However, the response to HSV-1 by microglia has not been characterized in a region-specific manner. This study investigated the time course of HSV-1 spread within the olfactory epithelium (OE) and CNS following intranasal inoculation and the corresponding macrophage/microglial response in a C57BL/6 mouse model. We found an apical to basal spread of HSV-1 within the OE and underlying tissue accompanied by an inflammatory response of macrophages. OE infection was followed by infection of a small subset of brain regions targeted by the TG in the brainstem and other cranial nerve nuclei, including the vagus and hypoglossal nerve. Furthermore, other brain regions were positive for HSV-1 antigens, such as the locus coeruleus (LC), raphe nucleus (RaN), and hypothalamus while sparing the hippocampus and cortex. Within each brain region, microglia activation also varied widely. These findings provide critical insights into the region-specific dissemination of HSV-1 within the CNS, elucidating potential mechanisms linking viral infection to neurological and neurodegenerative diseases.IMPORTANCEThis study shows how herpes simplex virus type 1 (HSV-1) spreads within the brain after infecting the nasal passages. Our data reveal the distinct pattern of HSV-1 through the brain during a non-encephalitic infection. Furthermore, microglial activation was also temporally and spatially specific, with some regions of the brain having sustained microglial activation even in the absence of viral antigens. Previous reports have identified specific brain regions found to be positive for HSV-1 infection; however, to date, there has not been a concise investigation of the anatomical spread of HSV-1 and the brain regions consistently vulnerable to viral entry and spread. Understanding these region-specific differences in infection and immune response is crucial because it links HSV-1 infection to potential triggers for neurological and neurodegenerative diseases.

Impact of local anesthesia on ciliary dyskinesia diagnosis by digital high-speed videomicroscopy.

It was hypothesized that local anesthesia administration would not significantly affect ciliary function in nasal epithelium. A prospective, simple-blind randomized study was conducted between 2020 and 2023. The study employed digital high-speed videomicroscopy to analyze ciliary beat frequency and pattern. A cohort of 38 participants was recruited, consisting of 25 healthy volunteers and 13 referred individuals (including seven diagnosed with PCD). Selection criteria ensured the absence of chronic respiratory diseases, recent respiratory tract infections, or regular use of nasal medications. Participants underwent nasal brushing with administration of lidocaine and naphazoline nasal spray in one nostril and saline in the contralateral nostril. Ciliary beat frequency and pattern were measured using digital high-speed video microscopy. Nasal spray administration did not significantly alter ciliary beat frequency or pattern compared to saline (p = 0.841 and p = 0.125, respectively). Subgroup analysis revealed consistent results across healthy volunteers, referred patients, and PCD patients. Local anesthesia with lidocaine and naphazoline spray did not affect ciliary function outcomes. These findings support the safe use of these agents in clinical practice for PCD diagnostic procedures. Further research with larger cohorts is warranted for validation.

Polybacterial Intracellular Macromolecules Shape Single-Cell Epikine Profiles in Upper Airway Mucosa.

The upper airway, particularly the nasal and oral mucosal epithelium, serves as a primary barrier for microbial interactions throughout life. Specialized niches like the anterior nares and the tooth are especially susceptible to dysbiosis and chronic inflammatory diseases. To investigate host-microbial interactions in mucosal epithelial cell types, we reanalyzed our single-cell RNA sequencing atlas of human oral mucosa, identifying polybacterial signatures (20% Gram-positive, 80% Gram-negative) within both epithelial- and stromal-resident cells. This analysis revealed unique responses of bacterial-associated epithelia when compared to two inflammatory disease states of mucosa. Single-cell RNA sequencing, in situ hybridization, and immunohistochemistry detected numerous persistent macromolecules from Gram-positive and Gram-negative bacteria within human oral keratinocytes (HOKs), including bacterial rRNA, mRNA and glycolipids. Epithelial cells with higher concentrations of 16S rRNA and glycolipids exhibited enhanced receptor-ligand signaling in vivo. HOKs with a spectrum of polybacterial intracellular macromolecular (PIM) concentrations were challenged with purified exogenous lipopolysaccharide, resulting in the synergistic upregulation of select innate (CXCL8, TNFSF15) and adaptive (CXCL17, CCL28) epikines. Notably, endogenous lipoteichoic acid, rather than lipopolysaccharide, directly correlated with epikine expression in vitro and in vivo. Application of the Drug2Cell algorithm to health and inflammatory disease data suggested altered drug efficacy predictions based on PIM detection. Our findings demonstrate that PIMs persist within mucosal epithelial cells at variable concentrations, linearly driving single-cell effector cytokine expression and influencing drug responses, underscoring the importance of understanding host-microbe interactions and the implications of PIMs on cell behavior in health and disease at single-cell resolution.

S100A9 induces tissue remodeling of human nasal epithelium in chronic rhinosinusitis with nasal polyp.

Chronic inflammation triggers tissue remodeling in human nasal epithelial (HNE) cells. S100A9, a protein secreted by inflammatory cells, exhibits potent proinflammatory activity. However, its effect on HNE cell remodeling, such as squamous metaplasia, remains unclear. Therefore, this study aimed to determine the effects and underlying pathways of S100A9 on HNE cell remodeling and investigate its clinical implications in chronic rhinosinusitis (CRS). Cultured HNE cells were treated with S100A9. Bulk RNA sequencing was performed to analyze gene ontology (GO). Ingenuity pathway analysis (IPA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were also analyzed. Additionally, immunohistochemistry and multiplex immunofluorescence were performed on tissue samples obtained from 60 patients, whose clinical informations were also reviewed. GO enrichment analysis indicated that S100A9 induced tissue remodeling in HNE cells toward squamous metaplasia. IPA and KEGG commonly showed that S100A9 affected HNE cells associated with the IL-17 signaling pathway, including target molecules such as matrix metalloproteinase 1 (MMP1) and small proline-rich protein 2A (SPRR2A). Squamous metaplasia with a marked expression of S100A9 was observed in 50% of CRS with nasal polyps (CRSwNPs). In addition, in multiplex immunofluorescence, the S100A9 in sub-epithelium was co-expressed with myeloperoxidase, a neutrophil marker, and MMP1 and SPRR2A were strongly expressed in epithelial remodeling. Clinically, the expression of S100A9 correlated with sino-nasal outcome test-22 (r=0.294, p=0.022) and Lund-Mackay scores (r=0.348, p=0.006). S100A9 induces tissue remodeling in HNE cells. Its increased expression in CRSwNP, particularly squamous epithelium, correlates with disease severity. This suggests the clinical potential of S100A9 as a biomarker for CRS severity.

Quality by Design Approach for the Development of Cariprazine Hydrochloride Loaded Lipid-Based Formulation for Brain Delivery via Intranasal Route.

Cariprazine (CPZ) is a third-generation antipsychotic medication that has been approved for treating schizophrenia. This study aimed to develop a cariprazine-loaded nanostructured lipid carrier (CPZ-NLCs) to prevent first-pass metabolism and improve bioavailability and site-specific delivery from the nose to the brain. The CPZ-NLCs were prepared using melt emulsification. The formulation was optimized using the Box-Behnken design (BBD); where the influence of independent variables on critical quality attributes, such as particle size and entrapment efficiency, was studied. The optimized batch (F6) had a particle size of 173.3 ± 0.6 nm and an entrapment efficiency of 96.1 ± 0.57%, respectively. The in vitro release showed >96% release of CPZ from NLC within 30 min. The optimized formulation's ex vivo studies revealed significantly increased CPZ permeability (>75%) in sheep nasal mucosa compared to the CPZ suspension (~26%). The ciliotoxicity study of the nasal mucosa revealed that the CPZ-NLC formulation did not affect the nasal epithelium. The intranasal administration of the formulation achieved 76.14±6.23 μg/ml concentration in the brain which was significantly higher than the oral CPZ suspension administration (30.46±7.24 μg/ml). The developed formulation was stable for 3 months. The study concluded that the developed CPZ-NLC could significantly improve the bioavailability with quick delivery to the brain.

Infant-derived human nasal organoids exhibit relatively increased susceptibility, epithelial responses, and cytotoxicity during RSV infection

BackgroundRespiratory syncytial virus (RSV) causes significant morbidity and mortality, especially in young children. Why RSV infection in children is more severe compared to healthy adults is not fully understood. MethodsWe used ex-vivo human nasal organoid platforms from infants and adults to investigate the underlying mechanism of this disease disparity at the initial site of RSV replication, the nasal epithelium. ResultsInfant-derived human nasal organoid-air liquid interface (HNO-ALIs) lines were more susceptible to early RSV replication. Moreover, infant-derived HNO-ALIs elicited a statistically significant greater overall cytokine response, enhanced mucous production, and greater cellular damage compared to their adult counterparts. Furthermore, the adult cytokine response was associated with a superior regulatory cytokine response, which could explain less cellular damage than in infant lines. ConclusionsOur data highlights substantial differences in how infant and adult upper respiratory tract epithelium responds to RSV infection at the cellular level. These differences in epithelial cellular response can lead to impaired mucociliary clearance, a more dysregulated innate immune response predisposing infants to more severe RSV infection compared to adults.

Lung antimicrobial proteins and peptides: from host defense to therapeutic strategies.

Representing severe morbidity and mortality globally, respiratory infections associated with chronic respiratory diseases, including complicated pneumonia, asthma, interstitial lung disease, and chronic obstructive pulmonary disease, are a major public health concern. Lung health and the prevention of pulmonary disease rely on the mechanisms of airway surface fluid secretion, mucociliary clearance, and adequate immune response to eradicate inhaled pathogens and particulate matter from the environment. The antimicrobial proteins and peptides contribute to maintaining an antimicrobial milieu in human lungs to eliminate pathogens and prevent them from causing pulmonary diseases. The predominant antimicrobial molecules of the lung environment include human α- and β-defensins and cathelicidins, among numerous other host defense molecules with antimicrobial and antibiofilm activity such as PLUNC (palate, lung, and nasal epithelium clone) family proteins, elafin, collectins, lactoferrin, lysozymes, mucins, secretory leukocyte proteinase inhibitor, surfactant proteins SP-A and SP-D, and RNases. It has been demonstrated that changes in antimicrobial molecule expression levels are associated with regulating inflammation, potentiating exacerbations, pathological changes, and modifications in chronic lung disease severity. Antimicrobial molecules also display roles in both anticancer and tumorigenic effects. Lung antimicrobial proteins and peptides are promising alternative therapeutics for treating and preventing multidrug-resistant bacterial infections and anticancer therapies.

Multidrug Combinations against SARS-CoV-2 Using GS-441524 or Ivermectin with Molnupiravir and/or Nirmatrelvir in Reconstituted Human Nasal Airway Epithelia.

Background. The emergence, global spread, and persistence of SARS-CoV-2 resulted in an unprecedented need for effective antiviral drugs. Throughout the pandemic, various drug development and treatment strategies were adopted, including repurposing of antivirals designed for other viruses along with a multitude of other drugs with varying mechanisms of action (MoAs). Furthermore, multidrug treatment against COVID-19 is an ongoing topic and merits further investigation. Method/Objectives. We assessed the efficacy of multidrug treatment against SARS-CoV-2 in reconstituted human nasal epithelia, using combinations of molnupiravir and nirmatrelvir as a baseline, adding suboptimal concentrations of either GS-441524 or ivermectin, attempting to increase overall antiviral activity while lowering the overall therapeutic dose. Results. Nirmatrelvir combined with molnupiravir, GS-441524, or ivermectin at suboptimal concentrations show increased antiviral activity compared to single treatment. No triple combinations showed improved inhibition of SARS-CoV-2 replication beyond what was observed for double treatments. Conclusions. In general, we observed that the addition of a third compound is not beneficial for antiviral activity, while various double combinations exhibit increased antiviral activity over single treatment.

Nasal microbionts differentially colonize and elicit cytokines in human nasal epithelial organoids.

Nasal colonization by Staphylococcus aureus or Streptococcus pneumoniae is associated with an increased risk of infection by these pathobionts, whereas nasal colonization by Dolosigranulum species is associated with health. H uman n asal epithelial o rganoids (HNOs) physiologically recapitulate human nasal respiratory epithelium with a robust mucociliary blanket. We reproducibly monocolonized HNOs with these three bacteria for up to 48 hours with varying kinetics across species. HNOs tolerated bacterial monocolonization with localization of bacteria to the mucus layer and minimal cytotoxicity compared to uncolonized HNOs. Human nasal epithelium exhibited both species-specific and general cytokine responses, without induction of type I interferons, consistent with colonization rather than infection. Only live S. aureus colonization induced IL-1 family cytokines, suggestive of inflammasome signaling. D. pigrum and live S. aureus decreased CXCL10, whereas S. pneumoniae increased CXCL11, chemokines involved in antimicrobial responses. HNOs are a compelling model system to reveal host-microbe dynamics at the human nasal mucosa.

A Quadruple Gene-Deleted Live BoHV-1 Subunit RVFV Vaccine Vector Reactivates from Latency and Replicates in the TG Neurons of Calves but Is Not Transported to and Shed from Nasal Mucosa.

Bovine herpesvirus type 1 (BoHV-1) establishes lifelong latency in trigeminal ganglionic (TG) neurons following intranasal and ocular infection in cattle. Periodically, the latent virus reactivates in the TG due to stress and is transported anterogradely to nerve endings in the nasal epithelium, where the virus replicates and sheds. Consequently, BoHV-1 is transmitted to susceptible animals and maintained in the cattle population. Modified live BoHV-1 vaccine strains (BoHV-1 MLV) also have a similar latency reactivation. Therefore, they circulate and are maintained in cattle herds. Additionally, they can regain virulence and cause vaccine outbreaks because they mutate and recombine with other circulating field wild-type (wt) strains. Recently, we constructed a BoHV-1 quadruple mutant virus (BoHV-1qmv) that lacks immune evasive properties due to UL49.5 and glycoprotein G (gG) deletions. In addition, it also lacks the gE cytoplasmic tail (gE CT) and Us9 gene sequences designed to make it safe, increase its vaccine efficacy against BoHV-1, and restrict its anterograde neuronal transport noted above. Further, we engineered the BoHV-1qmv-vector to serve as a subunit vaccine against the Rift Valley fever virus (BoHV-1qmv Sub-RVFV) (doi: 10.3390/v15112183). In this study, we determined the latency reactivation and nasal virus shedding properties of BoHV-1qmv (vector) and BoHV-1qmv-vectored subunit RVFV (BoHV-1qmv sub-RVFV) vaccine virus in calves in comparison to the BoHV-1 wild-type (wt) following intranasal inoculation. The real-time PCR results showed that BoHV-1 wt- but not the BoHV-1qmv vector- and BoHV-1qmv Sub-RVFV-inoculated calves shed virus in the nose following dexamethasone-induced latency reactivation; however, like the BoHV-1 wt, both the BoHV-1qmv vector and BoHV-1qmv Sub-RVFV viruses established latency, were reactivated, and replicated in the TG neurons. These results are consistent with the anterograde neurotransport function of the gE CT and Us9 sequences, which are deleted in the BoHV-1qmv and BoHV-1qmv Sub-RVFV.

Nasal epithelial gene expression identifies relevant asthma endotypes in the ATLANTIS study

IntroductionAsthma is an inflammatory airways disease encompassing multiple phenotypes and endotypes. Several studies suggested gene expression in nasal epithelium to serve as a proxy for bronchial epithelium, being a non-invasive...

Astodrimer sodium nasal spray forms a barrier to SARS-CoV-2 in vitro and preserves normal mucociliary function in human nasal epithelium

COVID-19 remains a severe condition for many including immunocompromised individuals. There remains a need for effective measures against this and other respiratory infections, which transmit via virus-laden droplets that reach the nasal or oral mucosae. Nasal sprays offer potential protection against viruses. Such formulations should preserve normal nasal mucociliary function. The antiviral barrier efficacy and effects on mucociliary function of astodrimer sodium nasal spray (AS-NS) were evaluated and compared with other available nasal sprays—low pH hydroxypropyl methylcellulose (HPMC-NS), iota-carrageenan (Carr-NS), nitric oxide (NO-NS), and povidone iodine (PI-NS). Assays simulated clinical conditions. Antiviral barrier function and cell viability were assessed in airway cell monolayers, while a model of fully differentiated human nasal epithelium (MucilAir™) was utilized to evaluate tissue integrity, cytotoxicity, cilia beating frequency, and mucociliary clearance. AS-NS reduced infectious virus in cell monolayers and demonstrated a benign cytotoxicity profile. In human nasal epithelium ex vivo, AS-NS had no impact on mucociliary function (cilia beating nor mucociliary clearance). Carr-NS, HPMC-NS, NO-NS and PI-NS demonstrated limited antiviral effects, while HPMC-NS caused inhibition of mucociliary function. Astodrimer sodium nasal spray demonstrates an acceptable nonclinical efficacy and safety profile as a barrier nasal spray against respiratory viral infection in the nasal cavity.

Liposomal Formulations of Anti-Alzheimer Drugs and siRNA for Nose-to-Brain Delivery: Design, Safety and Efficacy In Vitro

β-site amyloid precursor protein cleaving enzyme (BACE1) represents a key target for Alzheimer’s disease (AD) therapy because it is essential for producing the toxic amyloid β (Aβ) peptide that plays a crucial role in the disease’s development. BACE1 inhibitors are a promising approach to reducing Aβ levels in the brain and preventing AD progression. However, systemic delivery of such inhibitors to the brain demonstrates limited efficacy because of the presence of the blood-brain barrier (BBB). Nose-to-brain (NtB) delivery has the potential to overcome this obstacle. Liposomal drug delivery systems offer several advantages over traditional methods for delivering drugs and nucleic acids from the nose to the brain. The current study aims to prepare, characterize, and evaluate in vitro liposomal forms of donepezil, memantine, BACE-1 siRNA, and their combination for possible treatment of AD via NtB delivery. All the liposomal formulations were prepared using the rotary evaporation method. Their cellular internalization, cytotoxicity, and the suppression of beta-amyloid plaque and other pro-inflammatory cytokine expressions were studied. The Calu-3 Transwell model was used as an in vitro system for mimicking the anatomical and physiological conditions of the nasal epithelium and studying the suitability of the proposed formulations for possible NtB delivery. The investigation results show that liposomes provided the effective intracellular delivery of therapeutics, the potential to overcome tight junctions in BBB, reduced beta-amyloid plaque accumulation and pro-inflammatory cytokine expression, supporting the therapeutic potential of our approach.Graphical

Differential regulation of viral entry-associated genes modulated by inflammatory cytokines in the nasal epithelium.

This study aimed to investigate the impact of different types of nasal inflammation on the regulation of entry-associated genes of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), Middle East respiratory syndrome coronavirus (MERS-CoV), human coronavirus 229E (HCoV-229E), and influenza virus, in the nasal epithelium. Subjects were classified into three groups: control, eosinophilic chronic rhinosinusitis (ECRS), and noneosinophilic CRS (NECRS) groups. Angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2), alanyl aminopeptidase (ANPEP), dipeptidyl peptidase 4 (DPP4), and beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1), and beta-galactoside alpha-2,3-sialyltransferase 4 (ST3GAL4) were selected as key entry-associated genes for SARS-CoV-2, HCoV-229E, MERS-CoV, and influenza, respectively, and were evaluated. Brushing samples obtained from each group and human nasal epithelial cells cultured using an air-liquid interface system were treated for 7 days with typical inflammatory cytokines and analyzed using real-time polymerase chain reaction. Western blot analysis and confocal microscopy were performed. The entry-associated genes showed distinct regulation patterns in response to each interleukin-4 (IL-4), interleukin-13 (IL-13), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Specifically, ACE2 significantly decreased in type 2 cytokines (IL-4 and IL-13), while TMPRSS2 significantly decreased in type 1 cytokines (TNF-α and IFN-γ). ANPEP significantly decreased in both types of cytokines. Remarkably, DPP4 significantly increased in type 2 cytokines and decreased in type 1 cytokines. Moreover, ST6GAL1 and ST3GAL4 significantly increased in type 2 cytokines and decreased in type 1 cytokines, particularly IFN-γ. These findings were supported by western blot analysis and confocal imaging results, especially for ACE2 and DPP4. The findings regarding differential regulation suggest that patients with ECRS, primarily mediated by type 2 inflammation, may have lower susceptibility to SARS-CoV-2 and HCoV-229E infections but higher susceptibility to MERS-CoV and influenza infections.

Elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis and rare mutations.

The triple combination of elexacaftor/tezacaftor/ivacaftor (ETI) has dramatically improved the outcome of people with Cystic Fibrosis (pwCF) with at least one F508del mutation. However, carriers of rare cystic fibrosis transmembrane conductance regulator (CFTR) variants are not candidates for this innovative treatment. In this observational study, we report the results of the compassionate use of ETI in 10 pwCF carriers of rare mutations after 2 months of treatment. Rectal organoids and short-term cultures of nasal epithelium obtained from rectal suction biopsies and nasal brushing were obtained from four subjects. After 2 months of ETI, all patients (4 males, mean age 30.1 ± 13.3 years) showed a significant increase of FEV1% predicted values [+8.0 (3.5-12.7) %, p < 0.010], body mass index [+0.85 (0-1.22) kg/m2, p < 0.020] and cystic fibrosis questionnaire-revised [+19.5 (6.3-29.2) points, p < 0.009]. A significant decrease of sweat chloride concentration [-11.2 (-1.7 to -34.0) mmol/L, p < 0.020] and exacerbations [-1.5 (-2 to -1), p < 0.008] was also recorded. Overall, 7 out of 10 participants were considered full responders. All patients reported cough disappearance (n = 3) or reduction (n = 7). Long-term oxygen was discontinued in two out of three patients and one also stopped noninvasive ventilation and was removed from the lung transplantation waiting list. Despite the limited number of cases, our results support the use of CFTR modulators in patients with rare CFTR variants that are not currently approved for ETI in Europe.

Nasal symbiont Staphylococcus epidermidis restricts influenza A virus replication via the creation of a polyamine-deficient cellular environment

Studies on the immune-regulatory roles played by the commensal microbes residing in the nasal mucosa consider the contribution of antiviral immune responses. Here, we sought to identify the nasal microbiome, Staphylococcus epidermidis-regulated antiviral immune responses and the alteration of polyamine metabolites in nasal epithelium. We found that polyamines were required for the life cycle of influenza A virus (IAV) and depletion of polyamines disturbed IAV replication in normal human nasal epithelial (NHNE) cells. Inoculation of S. epidermidis also suppressed IAV infection and the concentration of polyamines including putrescine, spermidine, and spermine was completely attenuated in S. epidermidis-inoculated NHNE cells. S. epidermidis activated the enzyme involved in the production of ornithine from arginine and downregulated the activity of the enzyme involved in the production of putrescine from ornithine in nasal epithelium. S. epidermidis also induced the activation of enzymes that promote the extracellular export of spermine and spermidine in NHNE cells. Our findings demonstrate that S. epidermidis is shown to be able of creating an intracellular environment lacking polyamines in the nasal epithelium and promote the balance of cellular polyamines in favor of the host to restrict influenza virus replication.

A nasal airway-on-chip model to evaluate airflow pre-conditioning during epithelial cell maturation at the air-liquid interface

The function of a well-differentiated nasal epithelium is largely affected by airflow-induced wall shear stress, yet fewin vitromodels recapitulate this dynamic condition. Models which do expose cells to airflow exclusively initiate flow after the differentiation process has occurred.In vivo, basal cells are constantly replenishing the epithelium under airflow conditions, indicating that airflow may affect the development and function of the differentiated epithelium. To address this gap in the field, we developed a physiologically relevant microphysiological model of the human nasal epithelium and investigated the effects of exposing cells to airflow during epithelial maturation at the air-liquid interface. The nasal airway-on-chip platform was engineered to mimic bi-directional physiological airflow during normal breathing. Primary human nasal epithelial cells were seeded on chips and subjected to either: (1) no flow, (2) single flow (0.5 dyne cm-2flow on Day 21 of ALI only), or (3) pre-conditioning flow (0.05 dyne cm-2on Days 14-20 and 0.5 dyne cm-2flow on Day 21) treatments. Cells exposed to pre-conditioning showed decreased morphological changes and mucus secretions, as well as decreased inflammation, compared to unconditioned cells. Our results indicate that flow exposure only post-differentiation may impose acute stress on cells, while pre-conditioning may potentiate a properly functioning epitheliumin vitro.

Integrating 16S rRNA Sequencing, Microflora Metabolism, and Network Pharmacology to Investigate the Mechanism of SBL in Alleviating HDM-Induced Allergic Rhinitis.

Allergic rhinitis (AR) is a series of allergic reactions to allergens in the nasal mucosa and is one of the most common allergic diseases that affect both children and adults. Shi-Bi-Lin (SBL) is the modified formula of Cang Er Zi San (CEZS), a traditional Chinese herbal formula used for treating AR. Our study aims to elucidate the anti-inflammatory effects and mechanisms of SBL in house dust mite-induced AR by regulating gut microflora metabolism. In vivo studies showed that nasal allergies and the infiltration of inflammatory cells in the nasal epithelium were significantly suppressed by SBL. Moreover, SBL restored the impaired nasal epithelial barrier function with an increased tight junction protein expression and reduced the endothelial nitric oxide synthase (eNOS). Interestingly, SBL significantly reconstituted the abundance and composition of gut microbiota in AR mice; it increased the relative abundance of potentially beneficial genera and decreased the relative abundance of harmful genera. SBL also restored immune-related metabolisms, which were significantly increased and correlated with suppressing inflammatory cytokines. Furthermore, a network analysis and molecular docking indicated IL-6 was a possible target drug candidate for the SBL treatment. SBL dramatically reduced the IL-6 level in the nasal lavage fluid (NALF), suppressing the IL-6 downstream Erk1/2 and AKT/PI3K signaling pathways. In conclusion, our study integrates 16S rRNA sequencing, microflora metabolism, and network pharmacology to explain the immune mechanism of SBL in alleviating HDM-induced allergic rhinitis.