Human Nasal Mucosa Research Articles

IL-1β-induced epithelial cell and fibroblast transdifferentiation promotes neutrophil recruitment in chronic rhinosinusitis with nasal polyps

Neutrophilic inflammation contributes to multiple chronic inflammatory airway diseases, including asthma and chronic rhinosinusitis with nasal polyps (CRSwNP), and is associated with an unfavorable prognosis. Here, using single-cell RNA sequencing (scRNA-seq) to profile human nasal mucosa obtained from the inferior turbinates, middle turbinates, and nasal polyps of CRSwNP patients, we identify two IL-1 signaling-induced cell subsets—LY6D+ club cells and IDO1+ fibroblasts—that promote neutrophil recruitment by respectively releasing S100A8/A9 and CXCL1/2/3/5/6/8 into inflammatory regions. IL-1β, a pro-inflammatory cytokine involved in IL-1 signaling, induces the transdifferentiation of LY6D+ club cells and IDO1+ fibroblasts from primary epithelial cells and fibroblasts, respectively. In an LPS-induced neutrophilic CRSwNP mouse model, blocking IL-1β activity with a receptor antagonist significantly reduces the numbers of LY6D+ club cells and IDO1+ fibroblasts and mitigates nasal inflammation. This study implicates the function of two cell subsets in neutrophil recruitment and demonstrates an IL-1-based intervention for mitigating neutrophilic inflammation in CRSwNP.

Contribution of the Mobilome to the Configuration of the Resistome of Corynebacterium striatum

Corynebacterium striatum, present in the microbiota of human skin and nasal mucosa, has recently emerged as a causative agent of hospital-acquired infections, notable for its resistance to multiple antimicrobials. Its mobilome comprises several mobile genetic elements, such as plasmids, transposons, insertion sequences and integrons, which contribute to the acquisition of antimicrobial resistance genes. This study analyzes the contribution of the C. striatum mobilome in the transfer and dissemination of resistance genes. In addition, integrative and conjugative elements (ICEs), essential in the dissemination of resistance genes between bacterial populations, whose role in C. striatum has not yet been studied, are examined. This study examined 365 C. striatum genomes obtained from the NCBI Pathogen Detection database. Phylogenetic and pangenome analyses were performed, the resistance profile of the bacterium was recognized, and mobile elements, including putative ICE, were detected. Bioinformatic analyses identified 20 antimicrobial resistance genes in this species, with the Ermx gene being the most predominant. Resistance genes were mainly associated with plasmid sequence regions and class 1 integrons. Although an ICE was detected, no resistance genes linked to this element were found. This study provided valuable information on the geographic spread and prevalence of outbreaks observed through phylogenetic and pangenome analyses, along with identifying antimicrobial resistance genes and mobile genetic elements that carry many of the resistance genes and may be the subject of future research and therapeutic approaches.

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.

Native valve endocarditis caused by Corynebacterium striatum without underlying structural heart disease or indwelling cardiovascular medical devices: a case report

BackgroundCorynebacterium striatum (C. striatum) is a gram-positive, anaerobic bacillus found both environmentally and in human skin and nasal mucosa flora. It is reportedly the etiologic agent of community-acquired and nosocomial diseases and is significantly associated with bacteremia and medical endovascular devices. This is the rare case of mitral valve native valve endocarditis (NVE) caused by C. striatum occurring in a young adult without underlying structural heart disease or indwelling cardiovascular medical devices successfully treated with multidisciplinary therapy.Case presentationThe patient was a 28-year-old female with no medical history. She was transferred our hospital due to sudden onset of vertigo and vomit. A computed tomography on day 2 revealed the hydrocephalus due to the cerebellar infarction, and she underwent posterior fossa decompression for cerebellar infarction. An angiography on day 8 revealed a left vertebral artery dissection, which was suspected be the etiology. Afterwards, a sudden fever of 39 degrees developed on day 38. She was diagnosed with aspiration pneumonia and treated with ampicillin/sulbactam but was still febrile at the time of transfer for rehabilitation. Treatment continued with levofloxacin, the patient had no fever decline, and she was readmitted to our hospital. Readmission blood cultures (3/3 sets) revealed C. striatum, and an echocardiogram revealed an 11 mm long mitral valve vegetation, leading to NVE diagnosis. On the sixth illness day, cardiac failure symptoms manifested. Echocardiography revealed mitral valve rupture. She was transferred again on the 11th day of illness, during which time her mitral valve was replaced. C. striatum was detected in the vegetation. Following surgery, she returned to our hospital, and vancomycin administration continued. The patient was discharged after 31 total days of postoperative antimicrobial therapy. The patient experienced no exacerbations thereafter.ConclusionsWe report the rare case of C. striatum mitral valve NVE in a young adult without structural heart disease or indwelling cardiovascular devices.Clinical trial numberNot applicable.

Mucoadhesive in situ nasal gel of amoxicillin trihydrate for improved local delivery: Ex vivo mucosal permeation and retention studies

Orally administered amoxicillin is recommended as the first-line treatment of acute bacterial rhinosinusitis (ABR) and given in a high-dose regimen. However, the risk of various systemic adverse reactions and low oral bioavailability are unbearable, increasing the threat of antibiotic resistance. Therefore, nasal delivery of amoxicillin can be a potential approach for effectively treating ABR locally, as well as overcoming those drawbacks. In a way to guarantee the effectiveness for local therapy in nasal cavity, the permeation and retention properties are of significant importance considerations. Accordingly, the present work aimed to investigate the characteristics with respect to the nasal applicability of the in situ gelling amoxicillin trihydrate (AMT) and further evaluate its permeability and retention properties through human nasal mucosa. The lyophilized formulations were characterized utilizing the Differential Scanning Calorimetry (DSC) and X-ray Powder Diffraction (XRPD), and also evaluated for its polarity, reconstitution time, droplet size distribution, mucoadhesive properties, and ex vivo permeability and retention studies. The results confirmed that the in situ gelling AMT formulations possess adequate mucoadhesive behavior, especially the formulation containing 0.3 % of gellan gum. Substantially, the in situ gelling AMT formulations were able to retain the drug on the surface of nasal mucosa instead of permeating across the membrane; thus, suitable for treating nasal infections locally. Altogether, the in situ gelling systems demonstrates promising abilities as a delivery platform to enhance local application of AMT within the nasal cavity.

The function and mechanism of Human nasal mucosa-derived mesenchymal stem cells in allergic rhinitis in mice.

To investigate the immunomodulatory effects and potential mechanisms of human nasal mucosa-derived mesenchymal stem cells(hNMSCs) on mouse allergic rhinitis, and to compare them with human umbilical cord-derived mesenchymal stem cells (hUCMSCs). hNMSCs and hUCMSCs were isolated and cultured for identification from human nasal mucosa and umbilical cord tissues. A co-culture system of LPS-stimulated RAW264.7 cells/mouse peritoneal macrophages and MSCs was employed.Changes in inflammatory factors in RAW264.7 cells and the culture medium as well as the expression of NF-κB signaling pathway in RAW264.7 cells were detected. Forty-eight BALB/c mice were randomly divided into control, OVA, hNMSCs, and hUCMSCs groups. An allergic rhinitis (AR) model was established through ovalbumin (OVA) stimulation and treated with hNMSCs and hUCMSCs. Subsequent assessments included related symptoms, biological changes, and the expression of the NF-κB signaling pathway in the nasal mucosa of mice. MSCs can be successfully isolated from human nasal mucosa. Both hNMSCs and hUCMSCs interventions significantly reverseed the inflammation induced by LPS and suppressed the upregulation of the NF-κB signaling pathway in RAW264.7 cells. Treatment with hNMSCs and hUCMSCs alleviated mouse allergic symptoms, reduced levels of total IgE, OVA-specific IgE and IgG1 in mouse serum, TH2-type cytokines and chemokines in mouse nasal mucosa, and TH2-type cytokines in mouse spleen culture medium, while also inhibiting the expression of the NF-κB signaling pathway in the nasal mucosa of mice. moreover, the hNMSCs group showed a more significant reduction in OVA-specific IgG1 in serum and IL-4 expression levels in mouse spleen culture medium compared to the hUCMSCs group. Our findings suggest that hNMSCs can ameliorate allergic rhinitis in mice, with a certain advantage in anti-inflammatory effects compared to hUCMSCs. The NF-κB pathway is likely involved in the anti-inflammatory regulation process by hNMSCs.Therefore, hNMSCs might represent a novel therapeutic approach for allergic rhinitis.

Microbiome and mycobiome analyses in continuous positive airway pressure devices.

Microorganisms are likely present in continuous positive airway pressure (CPAP) devices used daily. Considering the potential risk of infections among CPAP device users, here we aimed to compare the microbiomes in CPAP devices with those in nasal mucosal samples obtained from corresponding individuals using these devices. We conducted a prospective cohort study at tertiary medical institutes. Samples were collected from the tubes and filters of CPAP devices and the nasal mucosa of corresponding individuals using these devices. Microbiomes and mycobiomes were analyzed using 16S ribosomal RNA and internal transcribed spacer region sequencing. Results were compared according to the sampling site and usage duration for each patient. Overall, 27 paired human nasal mucosa and CPAP samples were analyzed. Bacteria were present in 7 of 27 tubes (29.6%) and 22 of 27 filters (81.5%). Fungi were present in 2 of the 27 tubes (7.4%) and 16 of the 27 filters (59.3%). Actinobacteria and Firmicutes were the predominant phyla among all samples. Fungi were not detected in any of the nasal mucosal samples. However, Basidiomycota and Ascomycota were predominant in the CPAP filters and tube samples. No significant associations were identified among the results according to sampling site and usage duration. Bacteria or fungi can be detected to some extent in CPAP samples even if the CPAP usage period is short. The association between respiratory infections and these microbiomes or mycobiomes was not investigated. Further research might be required to determine the risk posed by CPAP devices as a microbial contamination source.

The novel thromboxane prostanoid receptor mediates CTGF production to drive human nasal fibroblast self-migration through NF-κB and PKCδ-CREB signaling pathways.

Chronic rhinosinusitis without nasal polyp (CRSsNP) is characterized by tissue repair/remodeling and the subepithelial stroma region in whose nasal mucosa has been reported by us to have thromboxane A2 (TXA2) prostanoid (TP) receptor and overexpress connective tissue growth factor (CTGF). Therefore, this study aimed to investigate the relationship between TP receptor activation and CTGF production/function in human CRSsNP nasal mucosa stromal fibroblasts. We found that TP agonists including U46619 and IBOP ([1S-[1α,2α(Z),3β(1E,3 S*),4α]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid) could promote CTGF protein/messenger RNA expression and secretion. The pharmacological intervention and TP activation assay with U46619 identified the possible participation of PKCμ, PKCδ, nuclear factor-κB (NF-κB), and cyclic AMP response element-binding protein (CREB) phosphorylation/activation in the CTGF induction. Moreover, a phorbol ester-phorbol-12-myristate 13-acetate (PMA) exhibited a similar cellular signaling and CTGF production profile to that elicited by TP activation. However, further small interfering RNA interference analysis revealed that only NF-κB and PKCδ-CREB pathways were necessarily required for TP-mediated CTGF production, which could not be completely supported by those findings from PMA. Finally, in a functional assay, although CTGF did not affect fibroblast proliferation, TP-mediated CTGF could drive novel self-migration in fibroblasts both in the scratch/wound healing and transwell apparatus assays. Meanwhile, the overall staining for stress fibers and formation of the lamellipodia and filopodia-like structures was concomitantly increased in the treated migrating cells. Collectively, we provided here that novel TP mediates CTGF production and self-migration in human nasal fibroblasts through NF-κB and PKCδ-CREB signaling pathways. More importantly, we also demonstrated that thromboxane, TP receptor, CTGF, and stromal fibroblasts may act in concert in the tissue remodeling/repair process during CRSsNP development and progression.

Locally released H2 and O2 from an artificial periosteum modulate the survival and reparative activities of stem cells derived from the aged human nasal mucosa after transplantation

Stem cell therapies are limited by poor cell survival and engraftment. Elderly diabetic patients (EDPs) have a greater risk of bone graft failure. Herein, a g-C3N4/polydopamine (PDA@g-C3N4) composite nanosheet was successfully fabricated via in situ polymerization of PDA on a g-C3N4 surface. Then, the PDA/g-C3N4 composite was crosslinked with a fibrin hydrogel to prepare an artificial periosteum for EDPs. With the help of NIR, we showed that the synthetic artificial periosteum released H2 and O2 and enhanced the survival and osteogenic differentiation of aged human nasal mucosa-derived ectodermal stem cells (hEMSCs) in microenvironments characterized by oxidative stress and hypoxia. The artificial periosteum had pleiotropic effects on aged hEMSC reparative activities, modulating cytokine secretion and the protein expression of effectors associated with vascularization, and bone formation in vivo. Our findings imply that the developed artificial periosteum loaded with hEMSCs has great promise for the repair of bone defects in EDPs.

LncRNA ZFAS1 Alleviated NLRP3 Inflammasome-Mediated Pyroptosis through Regulating miR-96-5p/Smad7 Signaling in Allergic Rhinitis

Introduction: The NLR family pyrin domain containing 3 (NLRP3)-mediated pyroptosis was positively correlated with the allergic rhinitis progression and was reported to be regulated by SMAD family member 7 (Smad7). Bioinformatics analysis revealed that Smad7 might be targeted by miR-96-5p, and miR-96-5p might be targeted by long noncoding RNA zinc finger antisense 1 (ZFAS1). However, the effects and regulatory mechanisms of the ZFAS1/miR-96-5p/Smad7 functional axis in allergic rhinitis have not been investigated. Methods: Human nasal mucosa epithelial cell line RPMI 2650 and C57BL/6 mice were obtained for in vitro and in vivo studies. Dual-luciferase reporter assay and RNA immunoprecipitation were implemented for detecting molecular interactions. Cell counting kit-8 and flow cytometry were used for measuring cell viability and pyroptosis. ELISA was obtained for monitoring cytokine secretion. RT-qPCR and Western blot were examined for determining RNA and protein expression. Results: In vitro studies revealed that ZFAS1 was downregulated in interleukin (IL)-13-treated RPMI 2650 cells, while overexpression of ZFAS1 enhanced cell viability and inhibited NLRP3-mediated pyroptosis and inflammatory response. ZFAS1 directly inhibited miR-96-5p to suppress NLRP3-mediated pyroptosis in IL-13-treated RPMI 2650 cells. MiR-96-5p bound to the 3′-untranslated region of Smad7 and knockdown of Smad7 significantly reversed the effects of miR-96-5p depletion. Moreover, in vivo experiments further confirmed the findings of in vitro studies and showed ZFAS1 overexpression or miR-96-5p inhibition alleviated allergic rhinitis in vivo. Conclusion: ZFAS1 downregulated the expression of miR-96-5p to upregulate Smad7 level, which subsequently inhibited NLRP3-mediated pyroptosis and inflammatory response to ameliorate allergic rhinitis.

Expression of NMU and NMUR1 in tryptase-positive mast cells and PBLs in allergic rhinitis patients' nasal mucosa.

The neuropeptide U (NMU) has been proven to elicit the release of mediators from mast cells (MCs) through its receptor NMUR1 in allergic inflammatory models. However, little is known about the correlations between NMU and MCs in human allergic rhinitis (AR). The objective of this study is to investigate the expressions of NMU and NMUR1 in the tryptase + MCs and the peripheral blood leukocytes (PBLs) in human nasal mucosa with AR. Specimens of nasal mucosa from patients with AR (n = 10) and control patients without AR (n = 8) were collected and soaked in frozen tissue liquid solution (OCT) in tum. Cryostat sections were prepared for immunofluorescence staining. Tryptase was used as a marker to detect mast cells and other tryptase + immune cells. The expression of NMU and NMUR1 was respectively determined by double staining using a confocal microscope. Neither NMU nor NMUR1 were detected in the tryptase + mast cells in the human nasal mucosa. To our surprise, both NMU and NMUR1 were co-expressed with tryptase in the PBLs within peripheral blood vessels in AR and controls. Our findings showed that NMU could not influence human nasal tryptase + mast cells directly through NMUR1 in AR. The co-expression of both NMU and NMUR1 with tryptase in the PBLs provided new insight into the potential roles of NMU and tryptase in the circulation PBLs, and the infiltrated PBLs may promote nasal allergic inflammation by producing tryptase and NMU.

Reduced Proliferative Capacity and Defense against Staphylococcus aureus in Human Nasal Mucosal Epithelium Lacking ZNF365

Introduction: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common chronic inflammatory disease of the nose characterized by barrier disruption and environmental susceptibility, and the deletion of ZNF365 may be a factor inducing these manifestations. However, there is no study on the mechanism of action between CRSwNP and ZNF365. Therefore, this study focuses on the effect of the zinc finger protein ZNF365 on the proliferation of nasal mucosal epithelial cells and their defense against Staphylococcus aureus (S. aureus). Methods: Immunohistochemistry and Western blot were applied to verify the changes of ZNF365 expression in nasal polyp tissues and control tissues, as well as in primary epithelial cells. ZNF365 was knocked down in human nasal mucosa epithelial cell line (HNEpc), and the proliferation, migration, and transdifferentiation of epithelium were observed by immunofluorescence, QPCR, CCK8, and cell scratch assay. The changes of mesenchymal markers and TLR4-MAPK-NF-κB pathway were also observed after the addition of S. aureus. Results: ZNF365 expression was reduced in NP tissues and primary nasal mucosal epithelial cells compared to controls. Knockdown of ZNF365 in HNEpc resulted in decreased proliferation and migration ability of epithelial cells and abnormal epithelial differentiation (decreased expression of tight junction proteins). S. aureus stimulation further inhibited epithelial cell proliferation and migration, while elevated markers of epithelial-mesenchymal transition and inflammatory responses occurred. Conclusion: ZNF365 is instrumental in maintaining the proliferative capacity of nasal mucosal epithelial cells and defending against the invasion of S. aureus. The findings suggest that ZNF365 may participate in the development of CRSwNP.

GLP-1 derivatives with functional sequences transit and migrate through trigeminal neurons

Patients with dementia are increasing with the aging of the population, and dementia has become a disease with high unmet medical needs. Glucagon-like peptide-1 (GLP-1), a neuropeptide, has been reported to improve learning and memory following intracerebroventricular administration. We focused on intranasal administration, which can deliver drugs noninvasively and efficiently to the brain. Although much of the human nasal mucosa is occupied by respiratory epithelium, many capillaries are present in the paracellular route of respiratory epithelium. Therefore, to incorporate GLP-1 into cells, we created a GLP-1 derivative by adding cell-penetrating peptides (CPP) and penetration accelerating sequences (PAS) to GLP-1. We investigated in vitro and in vivo function of PAS-CPP-GLP-1 to enable the translocation of GLP-1 directly from nose to brain. PAS-CPP-GLP-1 enhanced cellular uptake by macropinocytosis with CPP, efficiently escaped from the endosomes due to PAS, and exited the cells. PAS-CPP-GLP-1 also transited trigeminal nerve cells through axon transport and migrated to the adjacent trigeminal nerve cell. Moreover, PAS-CPP-GLP-1 showed significant improvement in learning memory in mice within 20 min of intranasal administration. These results suggested CPP and PAS may be important for the efficient transfer of GLP-1 to the site of action in the brain following intranasal administration.

Tissue-resident memory T cells exhibit phenotypically and functionally heterogeneous in human physiological and pathological nasal mucosa

Pathogens commonly enter mucosal barrier tissues and tissue-resident memory T cells (TRM) are essential for preventing mucosal lesions. However, the immunological properties of TRM cells in nasal mucosa are poorly known. In comparison with control tissues, decreasing CD103+ TRM cells were observed in Chronic rhinosinusitis with nasal polyps (CRSwNPs) and sinonasal inverted papilloma (SNIP), which presented high capability to produce effector cytokines. In CRSwNPs, we found that CD103+ TRM cells with higher cytokine and Granzyme B coexpressed high PD-1, CD103− TRM cells expressed higher IL-10. Homogenates isolated from CRSwNPs induced CD103 expression on peripheral T cells which could be inhibited by blocking TGF-β. The frequencies of CD103+ TRM cells in CRSwNPs were extremely negatively correlated with neutrophil infiltration. CD103+ TRM cells from Staphylococcus aureus positive CRSwNPs had a stronger response to SEB. Taken together, two phenotypically and functionally distinct subsets of TRM cells exist in nasal tissues and play critical roles in the progress of CRSwNPs and SNIPs.

Human nasal mucosa ectomesenchymal stem cells derived extracellular vesicles loaded omentum/chitosan composite scaffolds enhance skull defects regeneration

Engineered bone tissue that can promote osteogenic differentiation is considered an ideal substitute for materials to heal bone defects. Extracellular vesicle (EV)-based cell-free regenerative therapies represent an emerging promising alternative for bone tissue engineering. We hypothesized that EVs derived from human nasal mucosa-derived ectomesenchymal stem cells (hEMSCs) can promote bone tissue regeneration. Herein, hEMSCs were cultured with osteogenic induction medium or normal medium to generate two types of EVs. We first demonstrated that the two EVs exhibited strong potential to promote rat suture mesenchymal stem cell (SMSC) osteogenesis by transferring TG2 to SMSCs and regulating extracellular matrix (ECM) synthesis. Next, we developed a composite hydrogel made of porcine omentum and chitosan into which EVs were adsorbed to enable the effective delivery of EVs with sustained release kinetics. Implantation of the EV-loaded hydrogels in a critical-size rat cranial defect model significantly promoted bone regeneration. Therefore, we suggest that our hEMSC-derived EV-loading system can serve as a new therapeutic paradigm for promoting bone tissue regeneration in the clinic.

Antimicrobial and Defense Proteins in Chronic Rhinosinusitis with Nasal Polyps.

Background and Objectives: Chronic rhinosinusitis with nasal polyps (CRSwNP) presently remains a difficult disease to manage. Antimicrobial and defense proteins are important factors that could help characterize the role of microorganisms in CRSwNP pathogenesis, as the concept of microbial dysbiosis in CRS is still being considered. Our aim is to investigate the complex appearance, relative distribution and interlinks of human β defensin 2 (HBD-2), human β defensin 3 (HBD-3), human β defensin 4 (HBD-4), and cathelicidin LL 37 (LL 37) in chronic rhinosinusitis with nasal polyps (CRSwNP)-affected human nasal mucosa. Materials and Methods: The study group consisted of 48 samples from patients with CRSwNP. Samples were collected during functional endoscopic sinus surgery. The control group consisted of 17 normal healthy nasal mucosa samples gathered during routine septoplasty. β-defensin-2, β-defensin-3, β-defensin-4 and cathelicidin LL 37 in tissue were detected via immunohistochemical analysis. Results: HBD-2, HBD-3 and LL 37 were significantly decreased in epithelial cells in both primary and recurrent nasal polyp samples (p < 0.001) in comparison to control samples. HBD-2 was decreased in the subepithelial connective tissue of primary nasal polyp samples when compared to both recurrent polyp (p = 0.050) and control (p = 0.033) samples. In subepithelial connective tissue, significantly more HBD-3-positive structures were observed in primary nasal polyp samples (p = 0.049) than in control samples. In primary polyp samples, moderate correlations between connective tissue HBD-3 and connective (R = 0.584, p = 0.001) and epithelial tissue LL 37 (R = 0.556, p = 0.002) were observed. Conclusions: Decreased HBD-2, HBD-3 and LL 37 concentrations in the epithelium suggest a dysfunction of the epithelial barrier in patients with nasal polyps. Decreased subepithelial connective tissue HBD-2 suggests different responses to nasal microbiota in patients with primary nasal polyps compared to recurrent nasal polyps. Increased HBD-3 in subepithelial connective tissue suggests a possible role of this antimicrobial peptide in the pathogenesis of primary nasal polyps.

Optimization of mRNA extraction from human nasal mucosa biopsies for gene expression profile analysis by qRT-PCR.

Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) is the gold-standard method for analyzing modifications in gene expression in cells and tissues. However, large quantities of high-quality RNA samples are needed for analyzing the expression of multiple genes from one human tissue sample. Here, we provide an optimized protocol for extracting large amounts of RNA from human nasal mucosal biopsies. The quality and quantity of samples were sufficient for qRT-PCR analyses of the expressions of various genes, in duplicate. In contrast to other protocols, we optimized RNA isolation to increase the amount from nasal biopsy samples for analyses of multiple genes. In most previous publications, expressions of only one or a few genes, including housekeeping genes, were analyzed because the amount of biological material was small. We were able to improve our protocol with respect to the yield and quality of RNA. This is likely to produce better results from molecular analyses of very small biopsy samples of human nasal mucosa.

Symbiotic microbiome Staphylococcus epidermidis restricts IL-33 production in allergic nasal epithelium via limiting the cellular necroptosis

BackgroundAllergic rhinitis (AR) is characterized by airway inflammation in nasal mucosa from inhaled allergens and interleukin (IL)-33 is the potent inducer of Th2 inflammation in allergic nasal epithelium. Staphylococcus epidermidis is one of the most abundant colonizers of the healthy human nasal mucosa and might impact the allergen-induced inflammatory responses in the nasal epithelium. Thus, we sought to characterize the mechanism of S. epidermidis regulating Th2 inflammation and IL-33 production in AR nasal mucosa.ResultsThe AR symptoms were alleviated and eosinophilic infiltration, serum IgE levels, and Th2 cytokines were significantly decreased in OVA-sensitized AR mice in response to human nasal commensal S. epidermidis. The inoculation of S. epidermidis to normal human nasal epithelial cells reduced IL-33 and GATA3 transcriptions and also reduced IL-33 and GATA3 expression in AR nasal epithelial (ARNE) cells and the nasal mucosa of AR mice. Our data exhibited that the cellular necroptosis of ARNE cells might be involved in IL-33 production and inoculation of S. epidermidis decreased the phosphorylation of necroptosis enzymes in ARNE cells, which was related to the reduction of IL-33 production.ConclusionsWe present that human nasal commensal S. epidermidis reduces allergic inflammation by suppressing IL-33 production in nasal epithelium. Our findings indicate that S. epidermidis serves a role in blocking allergen-induced cellular necroptosis in allergic nasal epithelium which might be a key mechanism of reduction of IL-33 and Th2 inflammation.

Challenges in the Development and Application of Organ-on-Chips for Intranasal Drug Delivery Studies.

With the growing demand for the development of intranasal (IN) products, such as nasal vaccines, which has been especially highlighted during the COVID-19 pandemic, the lack of novel technologies to accurately test the safety and effectiveness of IN products in vitro so that they can be delivered promptly to the market is critically acknowledged. There have been attempts to manufacture anatomically relevant 3D replicas of the human nasal cavity for in vitro IN drug tests, and a couple of organ-on-chip (OoC) models, which mimic some key features of the nasal mucosa, have been proposed. However, these models are still in their infancy, and have not completely recapitulated the critical characteristics of the human nasal mucosa, including its biological interactions with other organs, to provide a reliable platform for preclinical IN drug tests. While the promising potential of OoCs for drug testing and development is being extensively investigated in recent research, the applicability of this technology for IN drug tests has barely been explored. This review aims to highlight the importance of using OoC models for in vitro IN drug tests and their potential applications in IN drug development by covering the background information on the wide usage of IN drugs and their common side effects where some classical examples of each area are pointed out. Specifically, this review focuses on the major challenges of developing advanced OoC technology and discusses the need to mimic the physiological and anatomical features of the nasal cavity and nasal mucosa, the performance of relevant drug safety assays, as well as the fabrication and operational aspects, with the ultimate goal to highlight the much-needed consensus, to converge the effort of the research community in this area of work.

Liquid nitric oxide donor for adjuvant therapy of acute ischemic stroke via nasal administration

ObjectivesThe aim of this study was to synthesize and characterize a novel NO donor, PEI-PO-NONOate, using propylene oxide and to investigate its biosafety and therapeutic efficacy via nasal administration in vitro and vivo. Experimental proceduresThe PEI-PO-NONOate was synthesized based on polyethylenimine (PEI) with different molecular weights and characterized using Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and ultraviolet (UV) spectroscopy. Cytotoxicity assays were performed on mouse fibroblast cells L929 and human nasal mucosa epithelial cells (HNEpC), and a rat middle cerebral artery occlusion (MCAO) model was established to evaluate the therapeutic efficacy of PEI-PO-NONOate via nasal administration. ResultsThe PEI-PO-NONOate was found to be stable under dark, dry, and airproof conditions, and its release was accelerated in an aqueous phase or acidic environment, while it was slowed down in a polyethylene glycol (PEG) mixture system. The NO donor released approximately 0.4, 0.5, and 0.6 μmol of gaseous NO from 1.0 mg of the polymer based on PEI600, PEI1800, and PEI10K, respectively. Cytotoxicity assays showed that the PEI-PO-NONOates had a cryoprotective effect as compared with PEI and PEI-PO. Furthermore, nasal administration of PEI-PO-NONOates resulted in a significant reduction in overall necrotic ratio as compared with the control group (16.4% versus 24.6%, p < 0.05). ConclusionThe findings of this study suggest that PEI-PO-NONOates may have potential as an adjuvant therapy for acute ischemic stroke when administered via the nasal route.