Nasal epithelial repair and remodeling in physical injury, infection, and inflammatory diseases

Ciliary Functional Analysis in Chronic Rhinosinusitis with Polyps after Multimodal Intervention: Oral Corticosteroid, Functional Endoscopic Sinus Surgery, and Omalizumab Injection

In her late 50 s, a woman with a medical history of endoscopic sinus surgery for chronic rhinosinusitis with nasal polyps (CRSwNP) experienced a relapse of nasal polyps, significantly impacting her breathing and sense of smell. She underwent a multifaceted treatment approach, including oral corticosteroids, functional endoscopic sinus surgery, and omalizumab injections. Digital high-speed videomicroscopy (DHSV) revealed only partial improvement in ciliary beat pattern and ciliary beat frequency with oral corticosteroid treatment, while significant improvement in these ciliary parameters was observed with omalizumab injections. Furthermore, administration of omalizumab resulted in a decrease in her SNOT-22 (Sinonasal Outcome Test 22) score. Notably, this case report represents the first study investigating ciliary function using DHSV in a patient treated with omalizumab.

Updated epithelial barrier dysfunction in chronic rhinosinusitis: Targeting pathophysiology and treatment response of tight junctions

Tight junction (TJ) proteins establish a physical barrier between epithelial cells, playing a crucial role in maintaining tissue homeostasis by safeguarding host tissues against pathogens, allergens, antigens, irritants, etc. Recently, an increasing number of studies have demonstrated that abnormal expression of TJs plays an essential role in the development and progression of inflammatory airway diseases, including chronic obstructive pulmonary disease, asthma, allergic rhinitis, and chronic rhinosinusitis (CRS) with or without nasal polyps. Among them, CRS with nasal polyps is a prevalent chronic inflammatory disease that affects the nasal cavity and paranasal sinuses, leading to a poor prognosis and significantly impacting patients' quality of life. Its pathogenesis primarily involves dysfunction of the nasal epithelial barrier, impaired mucociliary clearance, disordered immune response, and excessive tissue remodeling. Numerous studies have elucidated the pivotal role of TJs in both the pathogenesis and response to traditional therapies in CRS. We therefore to review and discuss potential factors contributing to impair and repair of TJs in the nasal epithelium based on their structure, function, and formation process.

Role of basal cells in nasal polyp epithelium in the pathophysiology of eosinophilic chronic rhinosinusitis (eCRS)

BACKGROUND

Basal cell hyperplasia is commonly observed in nasal polyp epithelium of eosinophilic chronic rhinosinusitis (eCRS). We examined the function and mechanisms of basal cell hyperplasia in the pathophysiology of eCRS.

METHODS

We found that normal human bronchial epithelial (NHBE) cells obtained basal cell characteristics when cultured with PneumaCult™-Ex Plus Medium. Most of the cells passaged three times expressed basal cell surface markers CD49f and CD271 by flow cytometry, and basal cell nuclear marker p63 by immunohistochemical staining. We named these NHBE cells with basal cell characteristics cultured Basal-like cells (cBC), and NHBE cells cultured with BEGM™ cultured Epithelial cells (cEC). The characteristics of cBC and cEC were examined and compared by RNA sequencing, RT-PCR, ELISA, and cell proliferation studies.

RESULTS

RNA sequencing revealed that cBC showed higher gene expression of thymic stromal lymphopoietin (TSLP), IL-8, TLR3, and TLR4, and lower expression of PAR-2 compared with cEC. The mRNA expression of TSLP, IL-8, TLR3, and TLR4 was significantly increased in cBC, and that of PAR-2 was significantly increased in cEC by RT-PCR. Poly(I:C)-induced TSLP production and LPS-induced IL-8 production were significantly increased in cBC. IL-4 and IL-13 stimulated the proliferation of cBC. Finally, the frequency of p63-positive basal cells was increased in nasal polyp epithelium of eCRS, and Ki67-positive proliferating cells were increased in p63-positive basal cells.

CONCLUSIONS

Type 2 cytokines IL-4 and IL-13 induce basal cell hyperplasia, and basal cells exacerbate type 2 inflammation by producing TSLP in nasal polyp of eCRS.

Histological Characteristics of Chronic Allergic Rhinitis Versus Non-allergy: Is There a Difference in the Remodeling?

Demonstrate the histological remodeling changes in the turbinates, identify the frequency of the two forms of rhinitis in the samples studied and determine the remodeling differences found in the two variants. Patients attended an otolaryngology service at the Social Security Hospital of city Sangolqui-Ecuador from February 2016 to June 2017. The allergic variant was determined when eosinophils were found by higher magnification field and non-allergic when they were not found in the submucosal segment. Epithelial, inflammatory, and stromal markers were analyzed. One hundred twenty histopathological samples were analyzed, 75% presented allergic rhinitis, the age averaged 36.2 years. When we compared between the allergic and non-allergic variants: epithelial and stromal markers we had significant differences, as well as between each of its components; except fibrosis. In relation to the inflammatory pattern, there were significant differences between the number of mast cells and stromal markers with eosinophils > 10 by field. The allergic type corresponded to 75% of patients with persistent severe rhinitis who underwent turbinectomy. Regarding remodeling, there was a statistically significant difference in favor of the allergic variant. Eosinophilia greater than 10 was directly related to mastocytosis and subepithelial edema.

Impact of Non-Pharmaceutical Interventions on the Incidence and Treatment of Chronic Rhinosinusitis during the COVID-19 Pandemic: A Nationwide Retrospective Cohort Study

Many countries have implemented non-pharmaceutical interventions (NPIs) to prevent the spread of COVID-19. However, the impacts of NPIs on the epidemiology and treatment of chronic rhinosinusitis (CRS) remain unclear. We analyzed 671,216 patients to investigate changes in the incidence rate and treatment frequency of CRS using Korean nationwide health insurance data between 2017 and 2021. The incidence rate (p < 0.001) and the number of outpatients (p < 0.001), patients hospitalized (p < 0.001), and patients prescribed antibiotics (p < 0.001) or steroids (p = 0.024) were significantly lower in the pandemic period than in the pre-pandemic period; however, the number of patients who underwent surgery was not different (p = 0.205). Additionally, the frequency of surgeries per patient was significantly lower in patients during the pandemic period (p < 0.001). In the interrupted time series analysis, the trends in the number of outpatients (p < 0.001), patients hospitalized (p < 0.001), patients who underwent surgery (p < 0.001), and patients prescribed antibiotics (p < 0.001) or steroids (p < 0.001) significantly changed after the onset of the COVID-19 pandemic. In summary, NPI implementation during the COVID-19 pandemic was associated with a reduction in the incidence and treatment of CRS.

Predictive Significance of Claudin-3 for Epithelial Barrier Dysfunction in Chronic Rhinosinusitis With Nasal Polyps

PURPOSE

The abnormal expression of tight junction (TJ) plays a vital role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, there is no appropriate tool to distinguish and diagnose epithelial barrier defects in clinical practice. This study aimed to evaluate the predictive value of claudin-3 for epithelial barrier dysfunction in CRSwNP.

METHODS

In this study, TJ protein levels were evaluated by real-time quantitative polymerase chain reaction, immunofluorescent, and immunohistochemistry staining in control subjects and CRSwNP patients. The receiver operating characteristic (ROC) curve was created to assess the predictive value of TJ breakdown in clinical outcomes. In vitro, human nasal epithelial cells were cultured at the air-liquid interface to analyze the transepithelial electrical resistance (TER) level.

RESULTS

The expression levels of occludin, tricellulin, claudin-3, and claudin-10 were decreased (all P < 0.05), and those of claudin-1 was increased (P < 0.05) in CRSwNP patients as compared to healthy subjects. Additionally, claudin-3 and occludin levels were negatively correlated with the computed tomography score in CRSwNP (all P < 0.05), and the ROC curve indicated that the claudin-3 level had the most predictive accuracy in evaluating epithelial barrier disruption (area under the curve = 0.791, P < 0.001). Finally, the time-series analysis showed the highest correlation coefficient between TER and claudin-3 (cross-correlation function = 0.75).

CONCLUSION

In this study, we suggest that claudin-3 could be a valuable biomarker for predicting nasal epithelial barrier defects and disease severity in CRSwNP.

Impact of patient-reported nasal symptoms on quality of life after endoscopic pituitary surgery: a prospective cohort study

PURPOSE

Endoscopic transsphenoidal surgery causes nasal morbidity and negatively affects health-related quality of life (HRQoL). Knowledge on actionable symptoms that could improve postoperative HRQoL is therefore important. This study assessed the impact of nasal symptoms on postoperative HRQoL.

METHODS

This perioperative cohort study included 103 adult patients undergoing endoscopic pituitary adenoma resection (August 2016-December 2018), with measurements preoperatively, and 5 days, 6 weeks and 6 months after surgery. Nasal symptoms were measured with the Anterior Skull base nasal inventory-12, and HRQoL with the Short Form-36 (SF-36) physical (PCS) and mental component scores (MCS). Linear regression analysis was used to assess (1) determinants of postoperative nasal morbidity, (2) associations between number of symptoms or (3) individual symptoms and HRQoL, and (4) the percentage of variance of HRQoL explained by nasal symptoms.

RESULTS

The number of nasal symptoms transiently increased after surgery. No significant treatment- or disease-related determinants of nasal morbidity were identified. The number of nasal symptoms was significantly associated with a lower PCS (β = - 1.0; 95%CI - 1.5, - 0.4), but not with MCS at 6 weeks. Similar results were observed at 6 months. Headaches (42.2%), problems with smell (42.0%), and taste (36.0%) were the most prevalent symptoms, while sense of smell and taste, and nasal discharge showed the strongest associations with HRQoL.

CONCLUSIONS

Postoperative nasal symptoms, in particular problems with smell and taste, significantly affect pituitary patients' physical HRQoL. Monitoring of these symptoms may aid in determining which patients may benefit from intensified follow-up and treatment, aiming to optimize HRQoL.

Transplantation of human iPS cell-derived airway cells on vitrigel membrane into rat nasal cavity

The nasal mucosa functions as a frontline biological defense against various foreign substances and pathogens. Maintaining homeostasis of the nasal epithelium is necessary to promote good health. Nasal epithelia are constantly replaced under normal conditions. However, hereditary diseases, including primary ciliary dyskinesia and cystic fibrosis, can result in intractable dysfunction of the nasal mucosa. Since there is no treatment for this underlying condition, extrinsic manipulation is necessary to recover and maintain nasal epithelia in cases of hereditary diseases. In this study, we explored the use of airway epithelial cells (AECs), including multi-ciliated airway cells (MCACs), derived from human induced pluripotent stem cells (hiPSCs) on porcine atelocollagen vitrigel membranes, as a candidate of a therapeutic method for irreversible nasal epithelial disorders. To confirm the regenerative capacity of iPSC-derived AECs, we transplanted them into nasal cavities of nude rats. Although the transplanted cells were found within cysts isolated from the recipient nasal respiratory epithelia, they survived in some rats. Furthermore, the surviving cells were composed of multiple cell types similar to the human airway epithelia. The results could contribute to the development of novel transplantation-related technologies for the treatment of severe irreversible nasal epithelial disorders.

The diverse roles of YAP in the regulation of human nasal epithelial remodeling

Yes-associated protein (YAP) is essential in maintaining tissue size. Aberrant epithelial remodeling is a key pathological alteration in both inflammation and benign tumors in nasal mucosa. We sought to investigate the expression and localization patterns of YAP in remodeled nasal epithelium of basal cell hyperplasia, goblet cell metaplasia and squamous metaplasia. YAP expression patterns were evaluated in tissues obtained from patients with NP (n = 45) and IP (n = 27), and control subjects with septal deviation (n = 17) and tissue-derived primary cell cultures. Compared to the normal epithelium, expressions of YAP were significantly higher in basal cell hyperplasia (NP, 11.4-fold; IP, 19.6-fold), followed by squamous metaplasia (8.2-fold) and mild to moderate goblet cell metaplasia (2.9-fold); while their expression was lower in severe goblet cell metaplasia (3.3-fold). Our resultsshowed that: 1) ectopic nuclear YAP expression associated with p63+ basal cell hyperplasia and the high proliferative potential epithelial cells; 2) increase of cytoplasmic YAP correlated with mild to moderate goblet cell metaplasia; 3) increase of cytoplasmic YAP correlated with squamous cell metaplasia. The in vitro cell model also demonstrated almost concordant changes of YAP with the mucosa findings. Different YAP expression and localization patterns should play critical but differential roles in the nasal epithelial remodeling processes under mucosal inflammation and benign tumor formation.

Mechanical compression enhances ciliary beating through cytoskeleton remodeling in human nasal epithelial cells

Nasal inflammatory diseases, including nasal polyps and acute/chronic sinusitis, are characterized by impaired mucociliary clearance and eventually inflammation and infection. Contact of nasal polyps with adjacent nasal mucosa or stagnated mucus within the maxillary sinus produces compressive mechanical stresses on the apical surface of epithelium which can induce cytoskeleton remodeling in epithelial cells. In this study, we hypothesized that compressive stress modulates ciliary beating by altering the mechanical properties of the cytoskeleton of ciliated cell basal bodies. For the primary human nasal epithelial cells, we found that the applied compressive stress higher than the critical value of 1.0 kPa increased the stroke speed of cilia leading to the enhancement of ciliary beating frequency and mucociliary transportability. Immunostained images of the cytoskeleton showed reorganization and compactness of the actin filaments in the presence of compressive stress. Analysis of beating trajectory with the computational modeling for ciliary beating revealed that the stroke speed of cilium increased as the relative elasticity to viscosity of the surrounding cytoskeleton increases. These results suggest that the compressive stress on epithelial cells increases the ciliary beating speed through cytoskeleton remodeling to prevent mucus stagnation at the early stage of airway obstruction. Our study provides an insight into the defensive mechanism of airway epithelium against pathological conditions. STATEMENT OF SIGNIFICANCE: Cilia dynamics of the nasal epithelium is critical for not only maintaining normal breathing but preventing inflammatory diseases. It has been shown that mechanical compressive stresses can alter the shape and phenotype of epithelial cells. However, the effect of compressive stress on cilia dynamics is unclear. In this study, we demonstrated that the oscillation speed of cilia in human nasal epithelial cells was increased by the applied compressive stress experimentally. The computational simulation revealed that the change of ciliary beating dynamics was attributed to the viscoelastic properties of the reorganized cytoskeleton in response to compressive stress. Our results will be beneficial in understanding the defensive mechanism of airway epithelium against pathological conditions.

Integrated mRNA and microRNA transcriptome profiling during differentiation of human nasal polyp epithelium reveals an altered ciliogenesis

BACKGROUND

Human adult basal stem/progenitor cells (BSCs) obtained from chronic rhinosinusitis with nasal polyps (CRSwNP) when differentiated in an air-liquid interface (ALI) usually provide a pseudostratified airway epithelium with similar abnormalities than original in vivo phenotype. However, the intrinsic mechanisms regulating this complex process are not well defined and their understanding could offer potential new therapies for CRSwNP (incurable disease).

METHODS

We performed a transcriptome-wide analysis during in vitro mucociliary differentiation of human adult BSCs from CRSwNP, compared to those isolated from control nasal mucosa (control-NM), in order to identify which key mRNA and microRNAs are regulating this complex process in pathological and healthy conditions.

RESULTS

A number of genes, miRs, biological processes, and pathways were identified during mucociliary differentiation of both CRSwNP and control-NM epithelia, and notably, we have demonstrated for the first time that genetic transcriptional program responsible of ciliogenesis and cilia function is significantly impaired in CRSwNP epithelium, presumably produced by an altered expression of microRNAs, particularly of those miRs belonging to mir-34 and mi-449 families.

CONCLUSIONS

This study provides for the first time a novel insight into the molecular basis of sinonasal mucociliary differentiation, demonstrating that transcriptome related to ciliogenesis and cilia function is significantly impaired during differentiation of CRSwNP epithelium due to an altered expression of microRNAs.

Stabilizing Cellular Barriers: Raising the Shields Against COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its clinical manifestation (COVID-19; coronavirus disease 2019) have caused a worldwide health crisis. Disruption of epithelial and endothelial barriers is a key clinical turning point that differentiates patients who are likely to develop severe COVID-19 outcomes: it marks a significant escalation in respiratory symptoms, loss of viral containment and a progression toward multi-organ dysfunction. These barrier mechanisms are independently compromised by known COVID-19 risk factors, including diabetes, obesity and aging: thus, a synergism between these underlying conditions and SARS-CoV-2 mechanisms may explain why these risk factors correlate with more severe outcomes. This review examines the key cellular mechanisms that SARS-CoV-2 and its underlying risk factors utilize to disrupt barrier function. As an outlook, we propose that glucagon-like peptide 1 (GLP-1) may be a therapeutic intervention that can slow COVID-19 progression and improve clinical outcome following SARS-CoV-2 infection. GLP-1 signaling activates barrier-promoting processes that directly oppose the pro-inflammatory mechanisms commandeered by SARS-CoV-2 and its underlying risk factors.

Prospects and Opportunities for Microsystems and Microfluidic Devices in the Field of Otorhinolaryngology

Microfluidic systems can be used to control picoliter to microliter volumes in ways not possible with other methods of fluid handling. In recent years, the field of microfluidics has grown rapidly, with microfluidic devices offering possibilities to impact biology and medicine. Microfluidic devices populated with human cells have the potential to mimic the physiological functions of tissues and organs in a three-dimensional microenvironment and enable the study of mechanisms of human diseases, drug discovery and the practice of personalized medicine. In the field of otorhinolaryngology, various types of microfluidic systems have already been introduced to study organ physiology, diagnose diseases, and evaluate therapeutic efficacy. Therefore, microfluidic technologies can be implemented at all levels of otorhinolaryngology. This review is intended to promote understanding of microfluidic properties and introduce the recent literature on application of microfluidic-related devices in the field of otorhinolaryngology.

Pathological Features of Free Graft and Pedicled Flap in the Nasal Cavity: An Animal Study

OBJECTIVES/HYPOTHESIS

Recent developments in reconstructive techniques for mucosal defects using mucoperiosteal materials have enabled rapid recovery of physiological function after endoscopic sinus surgery. Clinical trials have described the advantages, disadvantages, and different outcomes of free graft and pedicled flap, which, respectively, sacrifice or preserve blood flow. However, histological changes, that affect the postoperative outcomes after reconstruction, remain unclear. We created an animal model for the reconstruction of mucosal defects using free grafts and pedicled flaps, and evaluated them histologically.

STUDY DESIGN

Animal study.

METHODS

We created mucosal defects in the left nasal septum of 20 rabbits and performed reconstruction with free grafts and pedicled flaps. The distribution of ciliary and goblet cells at the reconstruction site was evaluated after 7 and 28 days using hematoxylin and eosin-stained sections to calculate the Ciliary Cell Index and Goblet Cell Index. The severity of inflammation was assessed using the Cartilage Inflammatory Cell Score.

RESULTS

Crusting and changes in the mucosal morphology at the reconstruction site occurred only in the free graft group. In addition, the pedicled flap group had significantly greater preservation of ciliary and goblet cells and less inflammatory cell infiltration into the septal cartilage (P < .05) than the free graft group.

CONCLUSIONS

After reconstruction procedures for mucosal defects, histopathological differences were observed between the free graft and pedicled flap. Reconstruction with pedicled flaps had advantages including preservation of healthy mucosal epithelium and suppression of inflammation on the reconstruction site. This indicated that reconstruction with pedicled flaps might have advantages over that with free grafts.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E428-E433, 2021.

Current and Alternative Therapies for Nasal Mucosa Injury: A Review

Nasal mucosa injury can be caused by trauma, radiotherapy, chronic infection such as sinusitis, and post sinus surgery. The rate of healing and its treatment are important in the recovery of patients especially in post sinus surgery, which introduces new injuries. In this review, the current knowledge in terms of the mechanism underlying nasal wound healing was initially discussed. The currently available treatment options for enhancement of wound healing following sinus surgery were discussed and these had included intravenous antibiotics or steroids, various nasal sprays, and nasal packing. In addition, emerging alternative therapies in nasal mucosa wound healing such as herbal medicine and the advancement of regenerative medicine therapies such as stem cells and their byproducts were also discussed. Despite the various available treatment options for wound healing in nasal mucosa, rigorous strong evidence of their efficacy is gravely warranted in order to recommend them as part of the treatment modality.

Alternative Experimental Models for Studying Influenza Proteins, Host-Virus Interactions and Anti-Influenza Drugs

Ninety years after the discovery of the virus causing the influenza disease, this malady remains one of the biggest public health threats to mankind. Currently available drugs and vaccines only partially reduce deaths and hospitalizations. Some of the reasons for this disturbing situation stem from the sophistication of the viral machinery, but another reason is the lack of a complete understanding of the molecular and physiological basis of viral infections and host-pathogen interactions. Even the functions of the influenza proteins, their mechanisms of action and interaction with host proteins have not been fully revealed. These questions have traditionally been studied in mammalian animal models, mainly ferrets and mice (as well as pigs and non-human primates) and in cell lines. Although obviously relevant as models to humans, these experimental systems are very complex and are not conveniently accessible to various genetic, molecular and biochemical approaches. The fact that influenza remains an unsolved problem, in combination with the limitations of the conventional experimental models, motivated increasing attempts to use the power of other models, such as low eukaryotes, including invertebrate, and primary cell cultures. In this review, we summarized the efforts to study influenza in yeast, Drosophila, zebrafish and primary human tissue cultures and the major contributions these studies have made toward a better understanding of the disease. We feel that these models are still under-utilized and we highlight the unique potential each model has for better comprehending virus-host interactions and viral protein function.

Notch-1 decreased expression contributes to leptin receptor downregulation in nasal epithelium from allergic turbinates

BACKGROUND

Allergic rhinitis is characterized by a remodeling of nasal epithelium. Since the Notch and TGF-β signaling pathways are known to be involved in cell differentiation and remodeling processes and leptin adipokine has already been identified as a marker for homeostasis in human bronchial and nasal epithelial cells of asthmatics, roles played by these pathways have been investigated for chronic allergic rhinitis.

METHODS

The leptin/leptin receptor expression has been investigated in a study with 40 biopsies from allergic (AR, n = 18) and non-allergic (C, n = 22) inferior turbinates, using immunohistochemistry, immunofluorescence staining and RT-PCR. In addition, extracts from in vitro samples prepared from primary cells of inferior turbinates as well as in vitro cultured human nasal epithelial RPMI 2650 cells (ATCC-CCL-30) were also tested for leptin expression and activation of the Notch-1 pathway.

RESULTS

With regards to AR, in vivo expression levels of both leptin and its receptor significantly decreased in comparison to C. Furthermore, leptin receptor mRNA was significantly reduced in AR as compared to C. Immunofluorescence showed an apparent co-expression of leptin receptor with Notch-1, which was not seen with TGF-β. In vitro, in primary turbinate epithelial cells, the expression of leptin receptor and Notch-1 significantly decreased in AR as compared to C. Moreover, in RPMI 2650 cells, leptin receptor expression was shown to be induced by Notch-1 ligand signaling.

CONCLUSION

Thus, both the leptin and Notch-1 pathways appear to represent markers for epithelial homeostasis in allergic rhinitis.

The hippo pathway effector Yes-associated protein promotes epithelial proliferation and remodeling in chronic rhinosinusitis with nasal polyps

BACKGROUND

Hippo-Yes-associated protein (YAP) pathway plays an important role in epithelial cell proliferation and development. However, its possible role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains unknown. We aim to investigate it on nasal epithelial proliferation and remodeling in CRSwNP.

METHODS

The expressions of hippo pathway components as well as Ki-67 and E-cadherin in the sinonasal mucosa and nasal epithelial cells were analyzed in 14 controls, 14 eosinophilic CRSwNP, and 14 noneosinophilic CRSwNP. Nasal epithelial cells from 6 controls, 6 eosinophilic CRSwNP, and 6 noneosinophilic CRSwNP were cultured and treated with lipopolysaccharide (LPS), Poly(I:C), or a selective YAP inhibitor verteporfin (VP).

RESULTS

The hippo pathway components MST1, LATS1/2, YAP, and TEAD1 were increased in both eosinophilic and noneosinophilic CRSwNP, particularly in nasal epithelial cells, along with upregulation of Ki-67 and downregulation of E-cadherin. The mRNA levels of YAP positively correlated with the Ki-67 mRNA levels, and negatively associated with the E-cadherin mRNA levels in polyp tissues and epithelial cells from nasal polyps (NPECs). LPS and Poly(I:C) upregulated the YAP expression in nasal epithelial cells accompanied by increased TEAD1 and Ki-67 expression. Conversely, YAP inhibition by VP decreased TEAD1 and Ki-67 expression in NPECs.

CONCLUSIONS

Hippo pathway components are abnormally upregulated in NPECs, and its effector YAP promotes nasal epithelial cells proliferation and remodeling in CRSwNP. It provides a rationale to explore inhibition of YAP as a novel therapeutic strategy for reducing the epithelial proliferation and remodeling in CRSwNP.

Comparative Transcriptomic and Metagenomic Analyses of Influenza Virus-Infected Nasal Epithelial Cells From Multiple Individuals Reveal Specific Nasal-Initiated Signatures

In vitro and in vivo research based on cell lines and animals are likely to be insufficient in elucidating authentic biological and physiological phenomena mimicking human systems, especially for generating pre-clinical data on targets and biomarkers. There is an obvious need for a model that can further bridge the gap in translating pre-clinical findings into clinical applications. We have previously generated a model of in vitro differentiated human nasal epithelial cells (hNECs) which elucidated the nasal-initiated repertoire of immune responses against respiratory viruses such as influenza A virus and rhinovirus. To assess their clinical utility, we performed a microarray analysis of influenza virus-infected hNECs to elucidate nasal epithelial-initiated responses. This was followed by a metagenomic analysis which revealed transcriptomic changes comparable with clinical influenza datasets. The primary target of influenza infection was observed to be the initiator of innate and adaptive immune genes, leaning toward type-1 inflammatory activation. In addition, the model also elucidated a down-regulation of metabolic processes specific to the nasal epithelium, and not present in other models. Furthermore, the hNEC model detected all 11 gene signatures unique to influenza infection identified from a previous study, thus supporting the utility of nasal-based diagnosis in clinical settings. In conclusion, this study highlights that hNECs can serve as a model for nasal-based clinical translational studies and diagnosis to unravel nasal epithelial responses to influenza in the population, and as a means to identify novel molecular diagnostic markers of severity.

Role of IL-13Rα2 in modulating IL-13-induced MUC5AC and ciliary changes in healthy and CRSwNP mucosa

BACKGROUND

The IL-13 receptor α2 (IL-13Rα2) is a receptor for IL-13 which has conflicting roles in mediating IL-13 responses in the lower airway, with little known about its impact on upper airway diseases. We sought to investigate the expression of IL-13 receptors, IL-13Rα1 and IL-13Rα2, in chronically inflamed nasal epithelium, and explore IL-13-induced signaling pathways in an in vitro model of human nasal epithelial cells (hNECs).

METHODS

The protein and mRNA expression levels of IL-13 and its receptors in nasal biopsies of patients with nasal polyps (NP) and healthy controls were evaluated. We investigated goblet cell stimulation with mucus hypersecretion induced by IL-13 (10 ng/mL, 72 hours) treatment in hNECs using a pseudostratified epithelium in air-liquid interface (ALI) culture.

RESULTS

There were significant increases in IL-13, IL-13Rα1, and IL-13Rα2 mRNA and protein levels in NP epithelium with healthy controls as baseline. MUC5AC mRNA positively correlated with IL-13Rα2 (r = .5886, P = .002) but not with IL-13Rα1 in primary hNECs. IL-13 treatment resulted in a significant increase in mRNA and protein levels of IL-13Rα2 only in hNECs. IL-13 treatment induced an activation of extracellular signal-regulated kinases (ERK)1/2 and an upregulation of C-JUN, where the IL-13-induced effects on hNECs could be attenuated by ERK1/2 inhibitor (50 μmol/L) or dexamethasone (10^-4 -10^-7  mol/L) treatment.

CONCLUSIONS

IL-13Rα2 has a potential role in IL-13-induced MUC5AC and ciliary changes through ERK1/2 signal pathway in the nasal epithelium. IL-13Rα2 may contribute to airway inflammation and aberrant remodeling which are the main pathological features of CRSwNP.

A possible role of stem cells in nasal polyposis

Since its discovery, the understanding of stem/progenitor cells raised dramatically in the last decade. Their regenerative potential is important to develop new therapeutic applications, but the identification advanced much faster than our understanding of stem/progenitor cells. In nasal polyposis, little is known about stem cells/progenitor cells and their ability. However, the further characterization of stem cells/progenitor cells may provide new treatment options for combating nasal polyposis. This review highlights the knowledge of the current literature about stem cells/progenitor cells in nasal polyposis and how this may be exploited in the development of novel treatment strategies.

Impaired Ciliogenesis in differentiating human bronchial epithelia exposed to non-Cytotoxic doses of multi-walled carbon Nanotubes

Background

Multi-walled carbon nanotubes (MWCNTs) are engineered nanomaterials used for a variety of industrial and consumer products. Their high tensile strength, hydrophobicity, and semi-conductive properties have enabled many novel applications, increasing the possibility of accidental nanotube inhalation by either consumers or factory workers. While MWCNT inhalation has been previously shown to cause inflammation and pulmonary fibrosis at high doses, the susceptibility of differentiating bronchial epithelia to MWCNT exposure remains unexplored. In this study, we investigate the effect of MWCNT exposure on cilia development in a differentiating air-liquid interface (ALI) model. Primary bronchial epithelial cells (BECs) were isolated from human donors via bronchoscopy and treated with non-cytotoxic doses of MWCNTs in submerged culture for 24 h. Cultures were then allowed to differentiate in ALI for 28 days in the absence of further MWCNT exposure. At 28 days, mucociliary differentiation endpoints were assessed, including whole-mount immunofluorescent staining, histological, immunohistochemical and ultrastructural analysis, gene expression, and cilia beating analysis.

Results

We found a reduction in the prevalence and beating of ciliated cells in MWCNT-treated cultures, which appeared to be caused by a disruption of cellular microtubules and cytoskeleton during ciliogenesis and basal body docking. Expression of gene markers of mucociliary differentiation, such as FOXJ1 and MUC5AC/B, were not affected by treatment. Colocalization of basal body marker CEP164 with γ-tubulin during days 1–3 of ciliogenesis, as well as abundance of basal bodies up to day 14, were attenuated by treatment with MWCNTs.

Conclusions

Our results suggest that a single exposure of bronchial cells to MWCNT during a vulnerable period before differentiation may impair their ability to develop into fully functional ciliated cells.

Electronic supplementary material

The online version of this article (10.1186/s12989-017-0225-1) contains supplementary material, which is available to authorized users.

RNA sequencing and pathway analysis identify tumor necrosis factor alpha driven small proline-rich protein dysregulation in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory disorder in which many pathways contribute to end-organ disease. Small proline-rich proteins (SPRR) are polypeptides that have recently been shown to contribute to epithelial biomechanical properties relevant in T-helper type 2 inflammation. There is evidence that genetic polymorphism in SPRR genes may predict the development of asthma in children with atopy and, correlatively, that expression of SPRRs is increased under allergic conditions, which leads to epithelial barrier dysfunction in atopic disease.

METHODS

RNAs from uncinate tissue specimens from patients with CRS and control subjects were compared by RNA sequencing by using Ingenuity Pathway Analysis (n = 4 each), and quantitative polymerase chain reaction (PCR) (n = 15). A separate cohort of archived sinus tissue was examined by immunohistochemistry (n = 19).

RESULTS

A statistically significant increase of SPRR expression in CRS sinus tissue was identified that was not a result of atopic presence. SPRR1 and SPRR2A expressions were markedly increased in patients with CRS (p < 0.01) on RNA sequencing, with confirmation by using real-time PCR. Immunohistochemistry of archived surgical samples demonstrated staining of SPRR proteins within squamous epithelium of both groups. Pathway analysis indicated tumor necrosis factor (TNF) alpha as a master regulator of the SPRR gene products.

CONCLUSION

Expression of SPRR1 and of SPRR2A is increased in mucosal samples from patients with CRS and appeared as a downstream result of TNF alpha modulation, which possibly resulted in epithelial barrier dysfunction.

Impact of Respiratory Virus Infections in Exacerbation of Acute and Chronic Rhinosinusitis

Rhinosinusitis (RS) is a symptomatic disease classification of many causes and is a major economic burden worldwide. It is widely accepted that RS is further classified into acute (ARS) and chronic (CRS) rhinosinusitis based on the duration of the symptoms, and that viral infection plays a large role in initiating or potentiating the disease. In this review, we examine the role of respiratory virus infection in the exacerbation of ARS and CRS. We explore the epidemiology of viral exacerbation of ARS and CRS and highlight key viruses that may cause exacerbation. We also review the current understanding of viral infections in the upper airway to further explain the putative underlying mechanisms of inflammatory events in ARS and CRS exacerbation. Advances in accurate diagnosis of the etiologic respiratory viruses of ARS and CRS symptoms which can lead to better disease management are also surveyed. In addition to the current treatments which provide symptomatic relief, we also explore the potential of harnessing existing antiviral strategies to prevent ARS and CRS exacerbation, especially with improved viral diagnostic tools to guide accurate prescription of antivirals against causative respiratory viruses.

A systematic review of the sinonasal microbiome in chronic rhinosinusitis

BACKGROUND

The interaction between the host and microorganisms in chronic rhinosinusitis (CRS) is poorly understood and is a growing area of interest. More recently, methodologies have been developed to assess the microbiome without the use of culture by analyzing the bacterial 16S ribosomal RNA gene. We reviewed the microbiome literature to better understand the role of microbes in CRS.

METHODS

Systematic review of studies that used the 16S ribosomal RNA gene deep sequencing.

RESULTS

Nine publications met the search criteria. Eight studies evaluated the microbiome in controls (total, 83 subjects; range, 3-28 per study), whereas six of the studies included patients with CRS (total, 121 patients; range, 7-43 per study). Various sequencing techniques, primers, sample sites, and extraction methods were used. Of the articles that specified the number of taxa in controls, an average of 1587 taxa were identified (range, 911-2330). Significant heterogeneity was noted among the studies; however, Firmicutes, Actinobacteria, and Bacteroides phyla were identified in every sample of control patients and patients with CRS. Three of the studies showed enrichment to some degree of Staphylococcus aureus in patients with CRS. The total bacterial burden in CRS was similar to the controls. One study demonstrated a decrease in diversity, whereas other studies did not show any changes in CRS when compared with controls.

CONCLUSION

Although there are common phyla present in both control patients and patients with CRS, no consistent enrichment of any particular taxon was identified. Our findings indicated that there was no clear single causative microbe in CRS. More studies are needed to better understand the significance of the host interaction with the microbiome and the role it plays in CRS.

IL-13 regulates human nasal epithelial cell differentiation via H3K4me3 modification

Introduction

Epigenetic regulation has been shown to play an important role in the development of inflammatory diseases, including chronic rhinosinusitis and nasal polyps. The latter are characterized by epithelial mis-differentiation and infiltration of inflammatory cytokines. H3K4me3 has been shown to be involved in regulating lineage commitment. However, the underlying mechanisms, especially in human nasal epithelial cells (HNEpC), remain underexplored. The objective of this study was to investigate the role of H3K4me3 in HNEpC differentiation treated with the Th2 cytokine IL-13.

Patients and methods

The expression levels of mRNA and proteins were investigated using reverse transcription-polymerase chain reaction (RT-PCR) assays and Western blot in nasal polyp tissues and human nasal epithelial cells respectively. We measured these levels of H3K4me3, MLL1 and targeted genes compared with control subjects.

Results

We demonstrate that expression of H3K4me3 and its methyltransferase MLL1 was significantly upregulated in IL-13-treated HNEpC. This elevation was also observed in nasal polyps. Expression of cilia-related transcription factors FOXJ1 and DNAI2 decreased, while goblet cell-derived genes CLCA1 and MUC5a increased upon IL-13 treatment. Mechanistically, knockdown of MLL1 restored expression of these four genes induced by IL-13.

Conclusion

These findings suggest that H3K4me3 is a critical regulator in control of nasal epithelial cell differentiation. MLL1 may be a potential therapeutic target for nasal inflammatory diseases.

Myrtol standardized affects mucociliary clearance

BACKGROUND

Myrtol standardized (Gelomyrtol forte) has been shown to be effective in controlling nasal symptoms of rhinosinusitis by promoting mucociliary clearance. Our aim was to evaluate the short- and long-term effects of myrtol on ciliated columnar cells and goblet cells in an in-vitro setting.

METHODS

Nasal epithelial cells were harvested (42 days) from an air-liquid interface (ALI) culture of human nasal epithelial stem/progenitor cells (hNESPCs), which was derived from biopsies of nasal inferior turbinate mucosa. Myrtol 0.1% was applied to the ALI culture system at 2 different time-points (day 0 and day 35) on progenitor and differentiated cells. Ciliary beat frequency (CBF), supernatant fluid, and ciliated and goblet cell markers were evaluated after short- (7 days) and long-term (42 days) treatment.

RESULTS

In the long-term treatment with myrtol, there was an increase in cilia area (type IV β-tubulin⁺ , 1.53-fold, p = 0.031) and ciliogenesis-related markers (Foxj1 and CP110) with no change in CBF, as compared with control. In addition, the short-term myrtol treatment group exhibited greater mucin secretion compared with control.

CONCLUSION

This study demonstrates, through cellular and molecular mechanisms, that myrtol standardized enhances the mucus production from goblet cells in the short term, and promotes ciliated cell differentiation in the long term.

Differences in the paranasal sinuses between germ-free and pathogen-free mice

BACKGROUND

The role of bacteria in the etiology of chronic rhinosinusitis (CRS) is not fully understood. Commensal bacteria may have a significant impact on the development of normal paranasal sinus anatomy and mucosal immunity, as they do in the gut. Studying the paranasal sinuses of germ-free (GF) mice may provide some insight into the effect of commensal bacteria on sinus structure and mucosal function.

METHODS

The paranasal sinuses of 5 GF mice were compared to 5 pathogen-free normal mice. Mice heads underwent computed tomography and images were compared for pneumatization and geometry of the sinuses. Histologically, slides were examined by light microscopy and compared for mucosal thickness, epithelial thickness, cilia, collagen, goblet cells, and nasal-associated lymphatic tissue (NALT).

RESULTS

No radiological differences were seen between groups. Overall, GF mice were found to have thinner mucosa (Δ 15.2 ± 5.2 μm, p = 0.004), thinner epithelium (Δ 5.5 ± 2.6 μm, p = 0.037), more collagen (Δ 5.8% ± 1.6%, p < 0.001), fewer goblet cells (Δ 29.3 ± 5.4, p < 0.001), and less NALT (Δ 14,900 ± 6700 μm(2) , p = 0.04). Subanalysis by region revealed significant differences for GF mice in the middle (thinner mucosa, thinner epithelium, fewer cilia, and more collagen) and posterior (fewer goblet cells) sinus sections.

CONCLUSION

The results of this study demonstrate that commensal microbiota significantly contribute to the structure and function of murine paranasal sinuses. Therefore, changes in commensal microbiota associated with CRS may alter the normal microbe host dialogue in humans and be implicated in the pathogenesis of CRS.

Alternative Method for Primary Nasal Epithelial Cell Culture Using Intranasal Brushing and Feasibility for the Study of Epithelial Functions in Allergic Rhinitis

Purpose

Although differentiated normal human nasal epithelial (NHNE) cells can be used to study the role of human nasal epithelium, there is a need for effective culture models of nasal epithelium in sinonasal disease status, including allergic rhinitis (AR). We aimed to examine the feasibility of intranasal brushing for culture of nasal epithelial cells in AR patients and to verify the hypothesis that allergic nasal epithelial (ARNE) cells differ in histologic and physiologic characteristics.

Methods

We established a system for isolating (via intranasal brushing) and culturing (with air-liquid interface, ALI) nasal epithelial cells from healthy volunteers (n=8) and AR patients (n=8). We used this system to compare the histologic findings and physiologic characteristics of NHNE and ARNE.

Results

The histology results showed that fully differentiated ALI culture was obtained at least 14 days after confluence and that both ciliated and secretory cells were well differentiated in ALI culture using nasal brushing. The histology results of ARNE culture were significantly different from NHNE. The number of ciliated cells was lower, and secretory cells were more dominant in ARNE cell culture compared to NHNE cells. We also observed, by electron microscopy, loose tight junctions and short cilia in cultured ARNE cells. In addition, the mRNA level of TSLP which was one of the epithelial-derived allergic cytokines was significantly higher, and the expressions of genes involved in ciliogenesis were lower in cultured ARNE cells without allergen stimulation.

Conclusions

Our findings suggest that ALI culture of ARNE cells using intranasal brushing may be an alternative method for epithelial cell culture in AR patients and that cultured ARNE cells will be useful for in vitro studies of the mechanisms at play during AR because they maintain unique allergic characteristics.

Molecular mechanisms of nasal epithelium in rhinitis and rhinosinusitis

Allergic rhinitis, nonallergic rhinitis, and chronic rhinosinusitis are multifactorial upper airway diseases with high prevalence. Several genetic and environmental factors are proposed to predispose to the pathogenesis of the inflammatory upper airway diseases. Still, the molecular mechanisms leading toward the onset and progression of upper airway diseases are largely unknown. The upper airway epithelium has an important role in sensing the environment and regulating the inhaled air. As such, it links environmental insults to the host immunity. Human sinonasal epithelium serves as an excellent target for observing induced early-phase events, in vivo, and with a systems biological perspective. Actually, increasing number of investigations have provided evidence that altered homeostasis in the sinonasal epithelium might be important in the chronic upper airway inflammation.

Corticosteroid treatment regulates mucosal remodeling in chronic rhinosinusitis with nasal polyps

OBJECTIVES/HYPOTHESIS

To investigate the effect of oral plus intranasal corticosteroid (CS) treatment on nasal polyp (NP) mucosa remodeling from patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP).

STUDY DESIGN

Case series, retrospective study.

METHODS

Patients (n = 18) with severe CRSwNP were treated with oral prednisone for 2 weeks and intranasal budesonide for 12 weeks. NP biopsies were obtained from patients biopsies before (w0) and after 2 weeks (w2) and 12 weeks (w12) of CS treatment. Matrix metalloprotease 1 (MMP-1), MMP-2, MMP-7, MMP-9, and tissue inhibitor of metalloprotease type 1 (TIMP-1) expression was evaluated by immunohistochemistry in cell and tissue structures. Epithelial damage, eosinophil infiltration, and collagen content were also examined in NP tissues before and after CS treatment.

RESULTS

Compared to w0: 1) oral plus intranasal CS significantly (P < .01) increased presence of submucosal glands at w2, decreased epithelial cell hyperplasia at w12, and decreased tissue eosinophilia at w2 and w12; 2) CS treatment significantly (P < .05) increased immunoreactivity for MMP-1 and MMP-2 in the epithelium at w2, but decreased immunoreactivity for MMP-9 in the epithelium at w2 and w12; 3) at w12, CS significantly (P < .05) reduced MMP-9 immunoreactive positivity and intensity in the extracellular matrix, while increasing total collagen amount in the extracellular matrix; and 4) CS treatment significantly (P < .01) reduced the number of eosinophils and their MMP and TIMP-1 immunoreactive expression.

CONCLUSIONS

CS treatment modulates NP mucosa remodeling, particularly by promoting epithelial repair, regulating tissue remodeling markers, increasing total collagen content, and reducing tissue eosinophil infiltration.

LEVEL OF EVIDENCE

4

Upper airway stem cells: understanding the nose and role for future cell therapy

The nose together with the paranasal sinuses has an approximate surface area of 100 to 200 cm(2) in adults, which is lined with pseudostratified columnar ciliated epithelium. It serves several important physiological functions such as conditioning and filtration of the inspired air and the provision of end organ for the sense of smell. It is also a physical and immunological barrier as it is the first site of interaction between the host tissue and foreign invaders (viruses, bacteria, and allergens). Our understanding of the complex cellular events occurring in response to inhaled agents during the development of common airway diseases has been significantly enhanced by the current status of in vivo and in vitro nasal experimental models. This will allow the development of novel therapeutic strategies designed to improve the physiological and immune defense functions of the nasal epithelium, as well as novel therapies for other common nasal diseases.

Regenerative medicine and nasal surgery

Nasal surgery is a constellation of operations that are intended to restore form and function to the nose. The amount of augmentation required for a given case is a delicate interplay between patient aesthetic desires and corrective measures taken for optimal nasal airflow. Traditional surgical techniques make use of autologous donor tissue or implanted alloplastic materials to restore nasal deficits. Limited availability of donor tissue and associated harvest site morbidity have pushed surgeons and researchers to investigate methods to bioengineer nasal tissues. For this article, we conducted a review of the literature on regenerative medicine as it pertains to nasal surgery. PubMed was searched for articles dating from January 1, 1994, through August 1, 2014. Journal articles with a focus on regenerative medicine and nasal tissue engineering are included in this review. Our search found that the greatest advancements have been in the fields of mucosal and cartilage regeneration, with a growing body of literature to attest to its promise. With recent advances in bioscaffold fabrication, bioengineered cartilage quality, and mucosal regeneration, the transition from comparative animal models to more expansive human studies is imminent. Each of these advancements has exciting implications for treating patients with increased efficacy, safety, and satisfaction.

The response of human nasal and bronchial organotypic tissue cultures to repeated whole cigarette smoke exposure

Exposure to cigarette smoke (CS) is linked to the development of respiratory diseases, and there is a need to understand the mechanisms whereby CS causes damage. Although animal models have provided valuable insights into smoking-related respiratory tract damage, modern toxicity testing calls for reliable in vitro models as alternatives for animal experimentation. We report on a repeated whole mainstream CS exposure of nasal and bronchial organotypic tissue cultures that mimic the morphological, physiological, and molecular attributes of the human respiratory tract. Despite the similar cellular staining and cytokine secretion in both tissue types, the transcriptomic analyses in the context of biological network models identified similar and diverse biological processes that were impacted by CS-exposed nasal and bronchial cultures. Our results demonstrate that nasal and bronchial tissue cultures are appropriate in vitro models for the assessment of CS-induced adverse effects in the respiratory system and promising alternative to animal experimentation.

Fluticasone furoate maintains epithelial homeostasis via leptin/leptin receptor pathway in nasal cells

Leptin is involved in the lung epithelial homeostasis. Its role in the nasal tract is largely unknown. Allergic rhinitis (AR) is induced by the allergen exposure leading to consequential structural abnormalities in the nasal epithelium. Topical corticosteroids are recommended as first-line therapy in AR. Parietaria pollen is one of the most important allergenic sources in the southern Europe. In vitro, in human nasal epithelial cell line RPMI 2650, we aimed to determine whether allergen stimulation acts on leptin/leptin receptor pathway and how fluticasone furoate (FF) influences this pathway. The effects of the major allergen recombinant Par j 1 (rPar j 1), of FF, of leptin, and of TGF-β1 on cell proliferation, on leptin/leptin receptor expression and modulation (by clonogenic test, by RT-q-RT-PCR, by immunocytochemistry and by flow-cytometry), and on STAT-3 activation (assessing nuclear translocation by western blot analysis) were assessed. We found that rPar j 1 and TGF-β1 significantly decreased cell proliferation and down-regulated the leptin/leptin receptor pathway, whereas FF and leptin reverted them, both alone and in combination. Furthermore, rPar j 1 reduced, while leptin and FF increased STAT-3 activation. In conclusion, FF and leptin itself are able to preserve nasal epithelial homeostasis restoring the leptin/leptin receptor pathway altered by rPar j 1 exposure.

Reconstituted human upper airway epithelium as 3-d in vitro model for nasal polyposis

Background

Primary human airway epithelial cells cultured in an air-liquid interface (ALI) develop a well-differentiated epithelium. However, neither characterization of mucociliar differentiation overtime nor the inflammatory function of reconstituted nasal polyp (NP) epithelia have been described.

Objectives

1^st) To develop and characterize the mucociliar differentiation overtime of human epithelial cells of chronic rhinosinusitis with nasal polyps (CRSwNP) in ALI culture system; 2^nd) To corroborate that 3D in vitro model of NP reconstituted epithelium maintains, compared to control nasal mucosa (NM), an inflammatory function.

Methods

Epithelial cells were obtained from 9 NP and 7 control NM, and differentiated in ALI culture for 28 days. Mucociliary differentiation was characterized at different times (0, 7, 14, 21, and 28 days) using ultrastructure analysis by electron microscopy; ΔNp63 (basal stem/progenitor cell), β-tubulin IV (cilia), and MUC5AC (goblet cell) expression by immunocytochemistry; and mucous (MUC5AC, MUC5B) and serous (Lactoferrin) secretion by ELISA. Inflammatory function of ALI cultures (at days 0, 14, and 28) through cytokine (IL-8, IL-1β, IL-6, IL-10, TNF-α, and IL-12p70) and chemokine (RANTES, MIG, MCP-1, IP-10, eotaxin-1, and GM-CSF) production was analysed by CBA (Cytometric Bead Array).

Results

In both NP and control NM ALI cultures, pseudostratified epithelium with ciliated, mucus-secreting, and basal cells were observed by electron microscopy at days 14 and 28. Displaying epithelial cell re-differentation, β-tubulin IV and MUC5AC positive cells increased, while ΔNp63 positive cells decreased overtime. No significant differences were found overtime in MUC5AC, MUC5B, and lactoferrin secretions between both ALI cultures. IL-8 and GM-CSF were significantly increased in NP compared to control NM regenerated epithelia.

Conclusion

Reconstituted epithelia from human NP epithelial cells cultured in ALI system provides a 3D in vitro model that could be useful both for studying the role of epithelium in CRSwNP while developing new therapeutic strategies, including cell therapy, for CRSwNP.

Live human nasal epithelial cells (hNECs) on chip for in vitro testing of gaseous formaldehyde toxicity via airway delivery

Cell models based on human nasal epithelial stem/progenitor cells (hNESPCs) are developed to obtain functional ciliated cells on modified Transwell inserts. The live hNECs are integrated into microfluidic platforms to mimic the 3D features of the human upper airway for in vitro testing of gaseous formaldehyde toxicity via airway delivery.