Ecnomotopic expression of olfactory receptors is affected by human apolipoproteins A-IMilano and A-II: evidence from liver microarray analyses.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory disorder, with neutrophilic inflammation representing a clinically challenging endotype due to its resistance to corticosteroids and biologics targeting type 2 responses. Single-cell RNA sequencing (scRNA-seq) studies are providing novel insights into the pathogenesis of CRSwNP, particularly the roles of neutrophils and stromal cells. This review discusses how scRNA-seq has inspired a new focus on stromal-immune cell crosstalk as a driver of neutrophilic inflammation. We emphasize the pathogenic contributions of fibroblasts, granzyme K-expressing (GZMK+) CD8+ T cells, and dysregulated cytokine networks such as interleukin (IL)-1β and C-X-C motif chemokine ligand (CXCL). Understanding these interactions is critical for developing endotype-specific therapies for refractory CRSwNP characterized by neutrophilic inflammation. ScRNA-seq has revealed a significant heterogeneity in neutrophils and stromal cell populations within CRSwNP, with distinct subpopulations exhibiting unique functional profiles. The IL-1β-activated indoleamine 2,3-dioxygenase 1-expressing (IDO1+) fibroblast subset drives neutrophilic inflammation in CRSwNP through secreting a number of CXCL chemokines. Lymphocyte antigen 6 family member D-expressing (LY6D+) club cells in nasal epithelium express high levels of S100 calcium binding protein A (S100A) 8 and S100A9, known as chemoattractants for neutrophils, under IL-1β stimulation. Fibroblast-derived CXCL12 recruits C-X-C motif chemokine receptor (CXCR) 4+GZMK+CD8+ T cells, establishing a feed-forward inflammatory loop. This cycle is driven by GZMK-mediated stromal activation, resulting in the secretion of potent neutrophil chemokines. Therapeuticstargeting of IL-1β and CXCL12-CXCR4 signaling show potential for suppressing neutrophilic inflammation in CRSwNP. Stromal and immune cell interactions drive neutrophilic inflammation in CRSwNP. Targeting these cells and their signaling networks offers promising avenues for precision therapy, aiming to control neutrophilic inflammation, reduce associated polyp recurrence, and improve long-term disease outcomes.

BackgroundThe nasal mucosa is the primary entry site for many respiratory viruses, and immune molecules present at the time of exposure may dictate if infection occurs. However, the baseline immune state in healthy adults – and how it influences susceptibility to viruses – remains poorly defined.MethodsLevels of 16 immune molecules were measured in nasal secretions from two independent cohorts of healthy adults (total n = 166, Luminex). Participants were clustered based on normalized concentrations of immune analytes to identify profiles. Anin vitroorganotypic model of the nasal epithelium was used to examine the effect of immune profiles on SARS-CoV-2 infection: primary human nasal epithelial cells (n = 9 donors) were grown at air-liquid interface to induce mucociliary differentiation (42 days), treated with recombinant human cytokines (72 hours), and then challenged with wildtype SARS-CoV-2 Omicron BA.1 (24 hours). SARS-CoV-2 entry factor expression (post-cytokines, pre-challenge) and viral infection (N gene) were measured by qRT-PCR.ResultsIn both cohorts, a unique cluster was observed, characterized by distinctly high levels of antiviral interferons – particularly IFN-λ3 – with comparatively low levels of inflammatory chemokines and cytokines. In contrast, individuals with high overall levels of inflammatory mediators had absent IFN-λ3.In vitro, pretreatment with IFN-λ3 and IFN-α2, but not with pro-inflammatory cytokines, significantly reduced SARS-CoV-2 replication in differentiated nasal epithelial cultures, despite upregulating ACE2 expression.ConclusionsHealthy adults exhibit distinct nasal immune profiles, with an IFN-λ3–dominant, low-inflammatory state conferring resistance to SARS-CoV-2 in vitro. The nasal immune milieu may influence susceptibility to respiratory viruses and the efficacy of mucosally administered vaccines.

DLX5 regulates nasal Epithelial Mesenchymal Transition and inflammation in EosCRSwNPs via the COL1A1-mediated Wnt/β-catenin Signaling.

Nasal epithelial cells expressing oxytocin receptor are involved in volatilized oxytocin effects on biased and social motivations and stress-declined neural stem cell proliferation.

Developmental exposure to benzalkonium chloride induces defects in mechanosensory hair cells and nociceptive responses in zebrafish.

Inflammatory responses and cilia reorganization induced by daily exposure to diesel exhaust particles in primary human nasal epithelium.

The olfactory placode (OP) gives rise to a wide array of chemosensory neurons in the nasal region, including olfactory sensory neurons, vomeronasal sensory neurons, and those of the septal organ and Grueneberg ganglion. During placodal invagination, the OP also produces migratory neurons such as gonadotropin-releasing hormone-1 (GnRH-1) neurons, terminal nerve (TN) neurons, and olfactory pioneer neurons, which are thought to initiate olfactory bulb development. Despite decades of research, the genetic lineage and molecular identity of OP-derived neuronal types remain under investigation. GnRH-1 neurons play essential roles in reproduction and chemodetection but appear genetically distinct from olfactory and vomeronasal chemosensory neurons. The Golgi-associated olfactory signaling regulator Goofy/Gfy is expressed in developing chemosensory neurons. To determine whether its expression is specific to nasal chemosensory epithelia or shared across OP derivatives, we characterized its expression and lineage at embryonic and postnatal stages. Our results confirm broad expression in developing chemosensory neurons and subsets of olfactory pioneer neurons, but not in GnRH-1 neurons, with only sparse expression in putative TN neurons. These findings reveal a previously unrecognized genetic distinction between nasal migratory and chemosensory neuronal populations.

Two complementary analytical approaches to study odorant metabolism in the olfactory epithelium.

Dysfunction of the middle ear can lead to hearing loss and the development of diseases such as cholesteatoma. Although radical treatment for cholesteatoma involves complete removal of the lesion, incomplete regeneration of the middle ear mucosa may contribute to hearing loss and recurrence of the cholesteatoma. This study aimed to evaluate the regenerative potential of topical retinoid therapy for damaged middle ear mucosa. We used a guinea pig model to investigate the regenerative effects of topical retinoids on middle ear mucosal damage. Retinoids, which are known to promote nasal mucosal epithelium regeneration, were applied to the middle ear. Histological analysis was performed to assess epithelial recovery, and auditory function testing was conducted to detect any signs of ototoxicity. The regenerated mucosa exhibited histological and functional characteristics comparable to those of normal ciliated epithelium. Furthermore, no ototoxicity was observed following the administration of retinoids. In the retinoid group, five of six ears (83%) demonstrated complete or partial healing, whereas none in the control group showed regeneration (p = 0.0183). The regenerated mucosa exhibited histological and functional characteristics comparable to those of normal ciliated epithelium. Furthermore, no ototoxicity was observed following the administration of retinoids. Topical retinoids may be an effective and novel therapeutic option for promoting the regeneration of middle ear mucosa without inducing ototoxic effects. Further investigations are required prior to clinical application in humans. NA.

BackgroundAmniotic epithelial cells are fetal-derived stem cells, capable of differentiating into all three germ layers, including mature epithelial cell populations. Here, we hypothesised that the amniotic epithelium might serve as a surrogate tissue source for investigating transcriptional profiles in the respiratory epithelium of newborns.MethodsIn this study, we compared gene expression profiles and weighted gene coexpression network structure in paired amniotic and newborn nasal epithelial samples from 85 participants in the Airway Epithelium Respiratory Illnesses and Allergy (AERIAL) cohort.ResultsIn total, 11 867 genes (79.7%) were commonly expressed in both amniotic and nasal epithelium, with uniquely expressed genes (2563 and 458, respectively) enriched for biological functions related to the specialist function of each tissue (e.g. developmental programs and ciliation, respectively). We observed a strong overlap in weighted gene coexpression network structure between both tissues, with 10 coexpression modules identified by consensus network analysis. Genes commonly expressed in both tissues and/or found in the consensus network modules were enriched for biologically relevant gene signatures and pathways related to airway function. We observed significant overlap in gene expression and network structure between the amniotic epithelium and published datasets of epithelial samples from lower airways and other epithelial tissues, including skin and oesophagus, suggesting a global epithelial signature.ConclusionWe observed significant overlap in gene expression and network structure between paired amniotic and nasal epithelial samples, supporting the potential of amnion as a noninvasive and abundant tissue surrogate. Future studies investigating amnion-based biomarkers for respiratory exposures in utero and childhood disease outcomes are needed to extend these results towards clinical translation.

The COVID-19 pandemic was initially characterized by a rapid succession of viral variants that emerged independently of each other, with each of these variants outcompeting the previous one. A major evolutionary shift occurred in late 2021, with the emergence of the highly divergent Omicron BA.1 variant. Since then, all the dominant SARS-CoV-2 variants have been derived from Omicron, for reasons that remain incompletely understood. Here, we compared the replication of SARS-CoV-2 variants in a human nasal epithelium model grown at 37°C and also at 33°C, a temperature that approximates that found in the nasal cavity. In this primary epithelial model, Omicron showed an early replicative advantage that was more marked at 33°C. However, Omicron triggered only a minimal antiviral interferon response at this temperature. Omicron could thus propagate rapidly while partly escaping the innate response at physiological nasal temperature, which helps account for the efficient dissemination of this variant worldwide.

Microplastics and nanoplastics (MNPs) have emerged as ubiquitous environmental contaminants; these particles have been detected in mucus and irrigation fluids, and at greater concentrations in patients with sinusitis and allergic rhinitis. Emerging evidence at other mucosal surfaces, including the gut and lung, suggests that MNPs exacerbate epithelial barrier dysfunction and induce inflammatory responses. Despite their relevance, the impact of inhaled plastics on the nasal epithelium, the initial point of contact for airborne plastics, remains underexplored. Submerged RPMI 2650 nasal epithelial cultures and air-liquid interface (ALI) cultures of primary human nasal epithelial cells were dosed with polystyrene (PS) MNPs, with a focus on the effects of 100nm nanoplastics and surface charge alterations. Analyses of secreted cytokines, transcriptomic changes, epithelial integrity, and histologic appearance were performed. Note that 100nm PS nanoplastics caused transcriptomic inflammatory and oxidative stress pathway activation in RMPI 2650 submerged cultures, with conserved inflammatory gene signatures in the ALI exposure model as well. Dose-dependent elevations in IL-8 and TNFα were observed after ALI exposure to 1 µm PS microplastics, and 100nm PS nanoplastics elicited early elevations in IL-6, IL-8, and TNF, with more pronounced effects from amine-modified particles, while no cytotoxicity, barrier disruption, or type-2 alarmin induction was observed. Scanning electron microscopy revealed ciliary disruption and particle adherence. PS MNPs cause inflammatory cytokine responses in nasal epithelial cells over even a short timeframe, in addition to ciliary blunting and transcriptional evidence of significant inflammation and stress response. This sinonasal model can help answer critical questions about the pathogenicity of plastic exposures.

Nasal epithelium is the site of infection for SARS‐CoV2 viruses, with interactions of the viral spike protein with the ACE2 receptor of the host cell. Molecular docking studies have shown that ivermectin shields the spike protein and thereby prevents binding to ACE2. Nasal application of high doses of ivermectin could be the right therapeutic approach in the treatment and prevention of COVID‐19. Tolerability, safety, and pharmacokinetics of ivermectin, administered nasally as 5% microsuspension (F004), were investigated in a randomized, double‐blind, parallel‐groups, placebo‐controlled phase 1 study in 28 healthy adults. Bioavailability of a single dose of 14 mg ivermectin was determined with AUC0–tT of 1701.1 ng/mL h (AUC0–∞ of 2382.7 ng/mL h, calculated), Cmax of 96.2 ng/mL, Tmax of 4.4 h, and T1/2 of 59.9 h. Following 42 mg/day multiple dose (3 × 14 mg every 6 h) administered nasally over 5 days, AUC0‐∞ of 2194.4 ng/mL h was analyzed, and 96% of ivermectin concentrations were still measurable 12 h after the last dose. F004 was safe in this study and well‐tolerated. Nine (F004 group) and three (placebo group) of 28 subjects reported 14 symptoms, including a few systemic but mainly local nasal adverse events (AE). The number of subjects reporting AE decreased continuously after both F004 and placebo treatment. All subjects recovered fully with no AE recorded at the end of the study. Nasal examination showed stable patterns of nasal mucosal grading, mucosal bleeding, and crusting of the mucosa. Nasally administered ivermectin is well tolerated in high concentrations and could provide systemic therapeutic benefits in addition to local effects.

Intranasal delivery represents a non-invasive and promising route to directly target the central nervous system (CNS), as it enables therapeutic agents to bypass the blood–brain barrier and allows repeated administration with low invasiveness. In this context, extracellular vesicles derived from adipose mesenchymal stem cells (ASC-EVs) are gaining increasing attention for their intrinsic neuroprotective and immunomodulatory properties, making them attractive candidates for the treatment of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). In this study, we established an in vitro epithelial barrier model using RPMI 2650 cells (derived from nasal epithelium carcinoma) cultured on transwell system and coupled with motor neuron-like NSC-34 cells treated with hydrogen peroxide to mimic oxidative stress-induced injury. This setup was designed to investigate the ability of ASC-EVs to cross the epithelial layer, representing the first step of access to the CNS following intranasal administration, and to reach damaged motor neurons. The study also explores the mechanisms underlying epithelial transport by evaluating both transcellular and paracellular routes through the use of selective pathway inhibitors and by monitoring changes in transepithelial electrical resistance (TEER) and junctional integrity. Our findings demonstrate that ASC-EVs are able to traverse the epithelial barrier and reach damaged motor neurons, where they are internalized and exert significant neuroprotective effects. These results provide a mechanistic basis supporting the potential of intranasally delivered ASC-EVs as a non-invasive therapeutic approach for ALS and other neurodegenerative disorders.

Association of nasal mucus cystatin SN levels with disease severity in patients with uncontrolled chronic rhinosinusitis.

Existing asthma polygenic risk scores (PRSs) have minimal validation in African-ancestry populations, leaving gaps in our understanding of the wide applicability of PRSs. To widen our understanding of the applicability of asthma PRSs, we apply published PRSs in African-ancestry individuals and quantify the extent to which the PRS-asthma relationship is mediated by clinical biomarkers and gene-expression signatures of asthma. We applied 22 PRSs from the PGS Catalog in 673 individuals from the Consortium on Asthma among African-Ancestry Populations in the Americas (CAAPA) and calculated the percent of the PRS-asthma relationship that is statistically mediated by clinical and nasal epithelium transcriptomic biomarkers of asthma. Asthma case/control status was defined as ever/never having a doctor's diagnosis of disease. For gene expression mediation analysis, we limited the cases to those with current disease. The PRS (PGS001782) created by the Global Biobank Meta-analysis Initiative (N = 32,658 individuals of African ancestry) performed the best (ΔAUC = 0.104, AUC = 0.657) adjusted for age, sex, study site, and the first two genetic principal components (PC1-2). The PRS's effect on asthma was mediated by total IgE (tIgE) (38.8%, p.adj < 0.0002), multi-allergen ImmunoCAP phadiatop specific IgE (sIgE) (38.7%, p.adj < 0.0002), and eosinophils (7.3%, p.adj = 0.004). Mediation was observed for gene expression modules related to T2 inflammation (21.9%, p.adj < 0.0024), wound healing (11.9%, p.adj = 0.008), and medication response (6.8%, p.adj = 0.049). We found the best PRS to be the one derived using the largest sample size and including African-ancestry individuals. Mediation supports the well-documented biology of T2 inflammation in asthma as well as pathophysiological components of asthma like wound healing and medication response.

Despite the progressive extension of CFTR variant eligibility to the triple combination of elexacaftor/tezacaftor/ivacaftor (ETI), most rare CFTR pathogenic variants remain ineligible for CFTR modulators. It is crucial to determine whether unexplored variants are rescuable by clinical modulators and to identify innovative therapeutic strategies for rescuing non-responder variants. The approach known as "theratyping" (in vitro testing of genotypes) has been accepted by the Food and Drug Administration (FDA) for the extension of clinical modulators' approval for in vitro responding genotypes. We used one of the most advanced models for theratyping: organoids derived from nasal epithelia of people with cystic fibrosis (pwCF). We optimized the forskolin-induced swelling (FIS) of organoids to assess CFTR basal or modulator-restored function. Nasal organoids mimicked the original epithelial tissue, CFTR residual activity, and modulator response. We set up the FIS assay using nasal organoids with reference genotypes and theratyped 38 rare (non-F508del) CFTR genotypes, either eligible or non-eligible for FDA approval, for treatment with ETI or ivacaftor. We found strong correspondence between the in vitro response of CFTR variants to modulators and their FDA approval status. Additionally, some previously uncharacterized CFTR variants have proven responsive to clinical modulators, with significant therapeutic implications. These results suggest that the nasal organoid FIS assay, pending confirmation of the prediction in the corresponding pwCF, might be considered as a powerful in vitro tool to predict modulator efficacy in each pwCF, guiding out-of-label prescription in CF, and to identify uncharacterized variants responsive to modulators. This approach may allow comparison of the efficacy of different therapeutics or the identification of innovative strategies for non-responding genotypes, improving personalized therapy and quality of life for pwCF.

Background and aimsLimited evidence suggests that airway epithelial structure and function is disrupted in very preterm infants; however, the epithelial morphology and physiology has not been well characterised following discharge from neonatal intensive care. This study aimed to characterise the nasal airway epithelium from 1-year-old survivors of very preterm birth.MethodsNasal brushings were sampled from infants born either at term or very preterm and differentiated cultures established. Fixed cultures were used for histological analysis and staining for cilia and mucus, with RNA collected for PCR analysis of tight junction proteins and cell type characterisation. Barrier integrity was assessed using transepithelial electrical resistance (TEER) and cell permeability assays.ResultsDifferentiated cultures were successfully established in 50% of preterm (final n=12, mean±sd 1.4±0.1 years) and 90% of term samples (final n=9, 2.7±0.6 years). Preterm cells had significantly reduced TEER (median (interquartile range (IQR)) 292.4 (160.6) Ω·cm−2versus 191.6 (114.5) Ω·cm−2; p<0.05) and showed increased cell permeability (median (IQR) 3.25 (5.13) cm·s−1versus 9.01 (2.30)×10−4 cm·s−1; p<0.01). PCR analysis of tight-junction related genes showed no statistical differences in expression of TJP1 or CLDN1, but protein staining revealed altered tight-junction patterning.ConclusionsThe airway epithelial barrier appears compromised in survivors of very preterm birth at 1 year of age. Reduced epithelial barrier strength creates vulnerability to infection and injury, which can negatively impact overall lung health across the lifespan.

Lung SPLUNC1-derived anti-biofilm peptide in polymeric nanoparticles: A novel strategy against S. aureus biofilms and antimicrobial resistance.