Role of p63/p73 in epithelial remodeling and their response to steroid treatment in nasal polyposis

Neutrophil extracellular traps promote ΔNp63+ basal cell hyperplasia in chronic rhinosinusitis

BACKGROUND

Neutrophil extracellular traps (NETs) are observed in chronic rhinosinusitis (CRS), although their role remains unclear.

OBJECTIVES

This study aimed to investigate the influence of NETs on the CRS epithelium.

METHODS

Forty-five sinonasal biopsy specimens were immunofluorescence-stained to identify NETs and p63+ basal stem cells. Investigators treated human nasal epithelial cells with NETs and studied them with immunofluorescence staining, Western blotting, and quantitative real-time PCR. NET inhibitors were administered to a murine neutrophilic nasal polyp model.

RESULTS

NETs existed in tissues in patients with CRS with nasal polyps, especially in noneosinophilic nasal polyp tissues. p63+ basal cell expression had a positive correlation with the release of NETs. NETs induced the expansion of Ki-67+p63+ cells. We found that ΔNp63, an isoform of p63, was mainly expressed in the nasal epithelium and controlled by NETs. Treatment with deoxyribonuclease (DNase) I or Sivelestat (NET inhibitors) prevented the overexpression of ΔNp63+ epithelial stem cells and reduced polyp formation.

CONCLUSIONS

These results reveal that NETs are implicated in CRS pathogenesis via basal cell hyperplasia. This study suggests a novel possibility of treating CRS by targeting NETs.

Expression Profiles of Matrix Metalloproteinases and Their Inhibitors in Nasal Polyps

Purpose

Nasal polyp (NP) is characterized by inflammation of the sinonasal mucosa with predominant inflammatory cell infiltration. Matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) are recognized to play an important role in leukocyte migration in airway inflammation. Herein, efforts were made to confirm the expression levels of MMPs/TIMPs and study the relationship between the infiltration of inflammatory cells and local expression levels of MMPs/TIMPs in NPs.

Patients and Methods

NP tissues were obtained from 42 Chinese patients with bilateral nasal polyps during the endoscopic sinus surgery. Inferior turbinate (IT) tissues from 19 patients with septal deviation were taken during the rhinoplasty surgery as controls. mRNA and protein levels of MMP1, MMP9, MMP10, MMP12, TIMP1 and TIMP3 were assessed by quantitative PCR and immunohistochemistry.

Results

Eosinophilia (72%, 23/32 samples), neutrophilia (41%, 13/32 samples), and increase in macrophages (38%, 12/32 samples) were found in NP tissues. mRNA expression of MMP1 (10.9-fold), MMP9 (4.1-fold), MMP10 (6.7-fold) and MMP12 (3.5-fold) were significantly up-regulated, while TIMP1 (1.5-fold) and TIMP3 (6.0-fold) were significantly down-regulated in NPs (n=42) as compared to the controls (n=19). The immunostaining levels of all 4 MMPs and two TIMPs were higher in NPs than those in controls. The co-localization of MMP1/MMP10/MMP12 and macrophages were identified in NPs. MMP9 was mainly expressed in neutrophils, while TIMP1 or TIMP3 were mostly found in eosinophils in NPs.

Conclusion

The results of our study indicate that tissue remodeling is significant in NPs, where MMPs/TIMPs play important roles in both tissue remodeling and inflammatory cells infiltration.

Hypoxia-inducible factor 1α activates the NLRP3 inflammasome to regulate epithelial differentiation in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is an upper airway inflammation disease associated with hypoxia-mediated inflammation. The effect of hypoxia-inducible factor 1α (HIF-1α) on NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation in the pathogenesis of sinonasal mucosa is unclear.

OBJECTIVE

We investigated the effect and mechanism of HIF-1α on NLRP3 inflammasome activation in the primary human nasal epithelial cells (hNECs).

METHODS

We measured the expression levels of HIF-1α and the NLRP3 inflammasome in nasal biopsy samples and hNECs derived from negative controls (healthy) and patients with CRS with and without nasal polyps, then further analyzed the specific mechanism of HIF-1α regulation of the NLRP3 inflammasome and its effect on hNEC differentiation.

RESULTS

Increased mRNA and protein expression levels of HIF-1α and the NLRP3 inflammasome were found in all CRS biopsy samples. HIF-1α enhanced expression of phosphorylated NLRP3 (S295) in both HEK293T cells and hNECs; it also promoted recruitment of caspase-1 and apoptotic speck-like protein containing caspase recruitment domain (aka ASC) by NLRP3. HIF-1α also improved NLRP3's stability by preventing NLRP3 degradation caused by hypoxia-mediated inflammation. In addition, HIF-1α could also increase expression of Mucin5AC and decrease expression of α-tubulin by promoting activation of the NLRP3 inflammasome in hNECs. In addition, HIF-1α could also directly promote P63 expression in hNECs.

CONCLUSION

HIF-1α could potentially induce cilia loss and enhance the proliferation of goblet cells, possibly mediated by the regulation of NLRP3 phosphorylation in CRS inflammation.

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.

Canadian multidisciplinary expert consensus on the use of biologics in upper airways: a Delphi study

BACKGROUND

Chronic rhinosinusitis with nasal polyposis (CRSwNP) often coexists with lower airway disease. With the overlap between upper and lower airway disease, optimal management of the upper airways is undertaken in conjunction with that of the lower airways. Biologic therapy with targeted activity within the Type 2 inflammatory pathway can improve the clinical signs and symptoms of both upper and lower airway diseases. Knowledge gaps nevertheless exist in how best to approach patient care as a whole. There have been sixteen randomized, double-blind, placebo-controlled trails performed for CRSwNP targeted components of the Type 2 inflammatory pathway, notably interleukin (IL)-4, IL-5 and IL-13, IL- 5R, IL-33, and immunoglobulin (Ig)E. This white paper considers the perspectives of experts in various disciplines such as rhinology, allergy, and respirology across Canada, all of whom have unique and valuable insights to contribute on how to best approach patients with upper airway disease from a multidisciplinary perspective.

METHODS

A Delphi Method process was utilized involving three rounds of questionnaires in which the first two were completed individually online and the third was discussed on a virtual platform with all the panelists. A national multidisciplinary expert panel of 34 certified specialists was created, composed of 16 rhinologists, 7 allergists, and 11 respirologists who evaluated the 20 original statements on a scale of 1-9 and provided comments. All ratings were quantitively reviewed by mean, median, mode, range, standard deviation and inter-rater reliability. Consensus was defined by relative interrater reliability measures-kappa coefficient ([Formula: see text]) value > 0.61.

RESULTS

After three rounds, a total of 22 statements achieved consensus. This white paper only contains the final agreed upon statements and clear rationale and support for the statements regarding the use of biologics in patients with upper airway disease.

CONCLUSION

This white paper provides guidance to Canadian physicians on the use of biologic therapy for the management of upper airway disease from a multidisciplinary perspective, but the medical and surgical regimen should ultimately be individualized to the patient. As more biologics become available and additional trials are published we will provide updated versions of this white paper every few years.

Impairment mechanism of nasal mucosa after radiotherapy for nasopharyngeal carcinoma

The nasal mucosa, which performs the crucial functions of filtering, humidifying and temperature regulation, is one of the most vulnerable areas of nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). Following RT, NPC patients experience a series of pathological changes in the nasal mucosa, ultimately leading to physiological dysfunction of the nasal epithelium. This article systematically reviews the clinical and pathological manifestations of RT-related nasal damage in NPC patients and summarizes the potential mechanism of damage to the human nasal epithelium by RT. Finally, we outline the current mechanistic models of nasal epithelial alterations after RT in NPC patients and provide additional information to extend the in-depth study on the impairment mechanisms of the nasal mucosa resulting from RT. We also describe the relationship between structural and functional alterations in the nasal mucosa after RT to help mitigate and treat this damage and provide insights informing future clinical and fundamental investigations.

Moderate Dose Irradiation Induces DNA Damage and Impairments of Barrier and Host Defense in Nasal Epithelial Cells in vitro

Purpose

Radiotherapy (RT) is the mainstay treatment for head and neck cancers. However, chronic and recurrent upper respiratory tract infections and inflammation have been commonly reported in patients post-RT. The underlying mechanisms remain poorly understood.

Method and Materials

We used a well-established model of human nasal epithelial cells (hNECs) that forms a pseudostratified layer in the air-liquid interface (ALI) and exposed it to single or repeated moderate dose γ-irradiation (1Gy). We assessed the DNA damage and evaluated the biological properties of hNECs at different time points post-RT. Further, we explored the host immunity alterations in irradiated hNECs with polyinosinic-polycytidylic acid sodium salt (poly [I:C]) and lipopolysaccharides (LPS).

Results

IR induced DNA double strand breaks (DSBs) and triggered DNA damage response in hNECs. Repeated IR significantly reduced basal cell proliferation with low expression of p63/KRT5 and Ki67, induced cilia loss and inhibited mucus secretion. In addition, IR decreased ZO-1 expression and caused a significant decline in the transepithelial electrical resistance (TEER). Moreover, hyperreactive response against pathogen invasion and disrupted epithelial host defense can be observed in hNECs exposed to repeated IR.

Conclusion

Our study suggests that IR induced prolonged structural and functional impairments of hNECs may contribute to patients post-RT with increased risk of developing chronic and recurrent upper respiratory tract infection and inflammation.

Transcriptomic and Lipidomic Profiles in Nasal Polyps of Glucocorticoid Responders and Non-Responders: Before and After Treatment

Background: The pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and mechanisms underlying different responses to systemic glucocorticoids (GC) remain unclear. The major aim of this study was to explore the transcriptomic and oxidative lipidomic signatures and the effects of GC in patients with different clinical responses.

Methods: Nasal polyp biopsies were obtained before and after 14-day oral GC treatment from 16 patients with CRSwNP, and normal nasal mucosa specimens were collected from 12 control subjects. RNA sequencing and oxidative lipidomics were performed, and differential gene expression analysis was conducted in the Responder and Non-responder groups at baseline and after treatment.

Results: In the Responder group, GC significantly improved clinical symptoms and reduced tissue eosinophil infiltration. Meanwhile, GC led to a pronounced transcriptomic reversion with robust suppression of inflammatory responses and abnormal metabolism of extracellular matrix, as well as restoration of cilia function. However, non-responders were mainly characterized by epithelial hyperplasia and keratinization, with much less transcriptomic improvement after GC treatment. Higher expression of type 2 inflammatory molecules (CCL13, IGHE, CCL18, CCL23, CCR3, and CLC) with lower levels of LACRT, PPDPFL, DES, C6, MUC5B, and SCGB3A1 were related to a stronger clinical response to GC. Besides decreased prostaglandins and increased leukotrienes, increased dysregulation in other oxylipid mediators derived from polyunsaturated fatty acids was determined in nasal polyps, which was ameliorated by GC treatment.

Conclusion: Systemic GC exert anti-inflammatory effects, improve tissue remodeling, restore cilia function, and ameliorate dysregulation of oxylipid mediator pathway in CRSwNP. GC-responders exhibited different transcriptomic signatures from non-responders.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-β Signaling in Human Nasal Epithelial Cells

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-β1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown. In the present study, to investigate how HMGB1 affects the barrier of normal human nasal epithelial cells, 2D and 2.5D Matrigel culture of primary cultured human nasal epithelial cells were pretreated with TGF-β type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. Knockdown of angulin-1/LSR downregulated the epithelial barrier. Treatment with EW-7197 decreased angulin-1/LSR and concentrated the expression at tTJs from bTJs and increased the epithelial barrier. Treatment with a binder to angulin-1/LSR angubindin-1 decreased angulin-1/LSR and the epithelial barrier. Treatment with HMGB1 decreased angulin-1/LSR and the epithelial barrier. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen. Pretreatment with EW-7197 prevented the effects of HMGB1. HMGB1 disrupted the angulin-1/LSR-dependent epithelial permeability barriers of HNECs via TGF-β signaling in HNECs.

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.

Eosinophils Correlate with Epithelial-Mesenchymal Transition in Chronic Rhinosinusitis with Nasal Polyps

INTRODUCTION

Chronic inflammation and tissue remodeling always occur together in chronic rhinosinusitis (CRS). Epithelial-mesenchymal transition (EMT) plays a critical role in airway remodeling.

OBJECTIVE

Changes of epithelial cells in sinus mucosa in different subtypes of CRS, especially in eosinophilic chronic rhinosinusitis with nasal polyps, and the role of EMT and eosinophils (EOS) in airway remodeling are still unknown.

METHODS

We included 85 patients in this study. They were divided into 4 groups: a normal control (NC) group, a chronic rhinosinusitis without nasal polyps (CRSsNP) group, an eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) group, and a noneosinophilic chronic rhinosinusitis with nasal polyps (non-ECRSwNP) group. Clinical data were all collected and analyzed. Standard hematoxylin and eosin staining, immunohistochemical staining, and 2-color immunofluorescence staining were performed. Biomarkers of EMT, epithelial cadherin, and vimentin were labeled. The immunohistochemistry results of each group were counted and statistically analyzed.

RESULTS AND CONCLUSION

E-cadherin was downregulated, and vimentin was upregulated in epithelial tissue from the ECRSwNP group, compared with that from the control group and the other groups. The number of vimentin-expressing epithelial cells correlated with sinus CT imaging Lund-Mackay scores (r = 0.560, p < 0.001). Moreover, expression levels of vimentin in the epithelium were associated with numbers of infiltrating EOS in tissues (r = 0.710, p < 0.001) and the peripheral blood EOS ratio (r = 0.594, p < 0.001). EMT occurred in patients with CRSwNP, especially in those with ECRSwNP. Epithelial reprogramming correlates with eosinophil infiltration and disease severity. Eosinophils contributed to impairment of epithelial function and promoted EMT in CRSwNP.

IL-13 modulates ∆Np63 levels causing altered expression of barrier- and inflammation-related molecules in human keratinocytes: A possible explanation for chronicity of atopic dermatitis

BACKGROUND

Barrier disruption and an excessive immune response in keratinocytes are now considered to have important roles in the pathophysiology of atopic dermatitis (AD). Furthermore, disturbed keratinocyte differentiation is considered to underlie AD. ΔNp63, a p53-like transcription factor, is a major regulator of keratinocyte differentiation. However, the functional significance of ΔNp63 in AD has not been clarified.

OBJECTIVE

In this study, we aimed to investigate the influence of the type 2 inflammatory environment on ΔNp63 expression and AD-associated molecules regulated by ΔNp63 in keratinocytes.

METHODS

The immunohistochemical expression profiles of ΔNp63 and AD-related molecules were evaluated in human skin tissue. The function of ΔNp63 in the regulation of AD-related molecules and the influence of the type 2 inflammatory environment on ΔNp63 expression were investigated using human primary keratinocytes. Expression of ΔNp63 was manipulated using the RNA interfering method.

RESULTS

In healthy skin tissue, we observed an inverse expression pattern between ∆Np63 and some barrier-related proteins including filaggrin, caspase-14, claudin-1, and claudin-4. ΔNp63 regulated expression of these genes and proteins. In addition, production of IL-1β and IL-33, pro-inflammatory cytokines, was modulated by ΔNp63. Furthermore, prolonged IL-13 exposure increased the thickness of the three-dimensional culture of keratinocytes. IL-13 interfered with ΔNp63 downregulation during calcium-induced keratinocyte differentiation. IL-13 modulated some barrier-related and inflammation-related molecules, which were regulated by ΔNp63.

CONCLUSIONS

We have shown that ΔNp63 modulated AD-related barrier and inflammatory molecules. In addition, ΔNp63 expression was affected by IL-4/IL-13. IL-13-ΔNp63 axis would integrate two major factors of AD pathogenesis: dysregulated barrier and inflammation.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Profiling of H3K27Ac Reveals the Influence of Asthma on the Epigenome of the Airway Epithelium

Background

Asthma is a chronic airway disease driven by complex genetic–environmental interactions. The role of epigenetic modifications in bronchial epithelial cells (BECs) in asthma is poorly understood.

Methods

We piloted genome-wide profiling of the enhancer-associated histone modification H3K27ac in BECs from people with asthma (n = 4) and healthy controls (n = 3).

Results

We identified n = 4,321 (FDR < 0.05) regions exhibiting differential H3K27ac enrichment between asthma and health, clustering at genes associated predominately with epithelial processes (EMT). We identified initial evidence of asthma-associated Super-Enhancers encompassing genes encoding transcription factors (TP63) and enzymes regulating lipid metabolism (PTGS1). We integrated published datasets to identify epithelium-specific transcription factors associated with H3K27ac in asthma (TP73) and identify initial relationships between asthma-associated changes in H3K27ac and transcriptional profiles. Finally, we investigated the potential of CRISPR-based approaches to functionally evaluate H3K27ac-asthma landscape in vitro by identifying guide-RNAs capable of targeting acetylation to asthma DERs and inducing gene expression (TLR3).

Conclusion

Our small pilot study validates genome-wide approaches for deciphering epigenetic mechanisms underlying asthma pathogenesis in the airways.

Downregulation of MCM2 contributes to the reduced growth potential of epithelial progenitor cells in chronic nasal inflammation

BACKGROUND

Recent studies have shown that human nasal epithelial progenitor cells (hNEPCs) are characterized by poor proliferation capacities during chronic nasal inflammation.

OBJECTIVE

We sought to investigate the key molecular functions and candidates that contribute to the reduced growth potential of hNEPCs in chronically inflamed nasal mucosa.

METHODS

Nasal biopsy specimens were obtained from 28 patients with nasal polyps (NPs) and 13 healthy controls. hNEPCs from nasal samples were cultured for 3 consecutive passages, and their molecular and functional profiles were analyzed by RNA sequencing. The minichromosome maintenance protein (MCM) family gene MCM2 was validated in hNEPCs and tissue samples from patients with NPs and control subjects by cell cycle, quantitative PCR, and Western blot analyses; small interfering RNA-mediated knockdown assay; and immunofluorescent staining.

RESULTS

Compared with control hNEPCs, NP-derived hNEPCs showed (1) reduced growth kinetics, as evidenced by the colony-forming efficiency and doubling time; (2) inhibited cell cycle progression, as evidenced by gene ontology and/or pathway and cell cycle analyses; and (3) downregulated expression of MCM2, the key protein of the MCM complex, which is critical for DNA replication at the G1/S checkpoint. Moreover, hNEPCs with MCM2 knockdown showed a decreased proliferation rate, and the MCM2 protein level in basal cells was significantly lower in abnormally remodeled nasal epithelium than in normal epithelium.

CONCLUSION

These results demonstrate inhibited cell cycle progression and MCM2 downregulation in basal or progenitor nasal epithelial cells from NP tissue, which may contribute to the decreased growth potential of hNEPCs in chronically inflamed upper airways.

p63+Krt5+ basal cells are increased in the squamous metaplastic epithelium of patients with radiation-induced chronic Rhinosinusitis

Background

Squamous metaplasia (SM) is an irreversible form of airway epithelial remodeling. Hyperproliferation of basal cells was observed in squamous metaplastic epithelium of chronically inflamed airway. However, the association of such aberrant proliferation of basal cells with SM in the nasal epithelium after radiation damage remains unclear. The aim of this study was to investigate SM and accompanying levels of p63⁺Krt5⁺ (basal cell markers) cells in the nasal epithelium of patients with radiation-induced chronic rhinosinusitis (CRSr) and patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared to healthy controls.

Methods

We assessed the prevalence of SM and the expression of p63⁺, Krt5⁺, p63⁺Krt5⁺, and Ki67⁺ cells through immunofluorescence(IF) staining of the inferior turbinate (IT) tissues from patients with CRSr (n = 36), CRSsNP (n = 33) and controls (n = 28).

Results

The prevalence of SM and the number of p63⁺Krt5⁺ cells were both significantly increased in patients with CRSr compared to patients with CRSsNP and controls. The number of Ki67⁺ cells were both significantly increased in patients with CRSr and CRSsNP compared to controls, but the ratio of Ki67⁺ cells to p63⁺Krt5⁺ cells was significantly lower in patients with CRSr compared to patients with CRSsNP. In patients with CRSr, an increased number of p63⁺Krt5+ basal cells was observed in SM epithelium compared to non-SM epithelium.

Conclusion

SM is increased in the nasal epithelium of patients with CRSr, in which aberrant levels of p63⁺Krt5⁺ basal cells serves as an important pathologic feature in the squamous metaplastic epithelium.

Long-term defects of nasal epithelium barrier functions in patients with nasopharyngeal carcinoma post chemo-radiotherapy

BACKGROUND AND PURPOSE

Chronic and recurrent upper respiratory tract infection and inflammation is common in patients with nasopharyngeal carcinoma (NPC) post chemo-radiotherapy (CRT). Whether it is due to intrinsic (e.g., host-defense mechanisms of the epithelium), epigenetic or extrinsic factors is not fully understood.

MATERIALS AND METHODS

Tissue biopsies of the middle turbinate (MT) and inferior turbinate (IT) from NPC patients after CRT (mean of 3 years, n = 39) were compared with the IT biopsies from healthy subjects (n = 44). The epithelial ultrastructure was examined by transmission electron microscope (TEM). mRNA and protein expressions of epithelial stem/progenitor cells markers, as well markers of cell proliferation and differentiation markers was analyzed.

RESULTS

Abnormal epithelial architecture was observed in all tissue samples of NPC patients. Significantly decreased expression levels of mRNA and protein levels for p63 (basal cells), Ki67 (cell proliferation), p63⁺/KRT5⁺ (epithelial stem/progenitor cells), MUC5AC and MUC5B (secretary proteins from goblet cells), alpha-tubulin, beta-tubulin and TAp73 (ciliated cells), DNAH5 and DNAI1 and RSPH4A (microtubule assemblies of motile cilia), FOXJ1 and CP110 (ciliogenesis-associated markers) were evident in MT and IT biopsies from NPC patients when compared to healthy controls.

CONCLUSION

CRT causes long-term defects of epithelial barrier functions and increases the susceptibility of these patients to upper respiratory tract infection and inflammation.

Novel findings in immunopathophysiology of chronic rhinosinusitis and their role in a model of precision medicine

Our understanding of the pathophysiology of chronic rhinosinusitis (CRS) is continuously evolving. The traditional description of CRS in terms of two phenotypes based on the presence or absence of nasal polyps belies the underlying intricate immunopathophysiological processes responsible for this condition. CRS is being increasingly recognized as a disease spectrum encompassing a range of inflammatory states in the sinonasal cavity, with non-type 2 inflammatory disease on one end, type 2 inflammatory, eosinophil-heavy disease on the other and an overlap of both in different proportions in between. Abundance in research on the immune mechanisms of CRS has revealed various new endotypes that hold promise as biomarkers for the development of targeted therapies in severe, uncontrolled CRS. The introduction of precision medicine to manage this chronic, complex condition is a step forward in providing individualized care for all patients with CRS. In this review, the latest research on the pathophysiology of CRS with a focus on potential novel biomarkers and treatment options over the last 2 years are summarized and integrated into a suggested model of precision medicine in CRS.

Epithelial cell function and remodeling in nasal polyposis

OBJECTIVE

To review the latest discoveries on airway epithelial cell diversity and remodeling in type 2 inflammation, including nasal polyposis.

DATA SOURCES

Reviews and primary research manuscripts were identified from PubMed, Google, and Bioarchives, using the search words airway epithelium, nasal polyposis, or chronic rhinosinusitis with nasal polyposis AND basal cell, ciliated cell, secretory cell, goblet cell, neuroendocrine cell, pulmonary neuroendocrine cell, ionocyte, brush cell, solitary chemosensory cell, microvillus cell, or tuft cell.

STUDY SELECTIONS

Studies were selected based on novelty and likely relevance to airway epithelial innate immune functions or the pathobiology of type 2 inflammation.

RESULTS

Airway epithelial cells are more diverse than previously appreciated, with specialized subsets, including ionocytes, solitary chemosensory cells, and neuroendocrine cells that contribute to important innate immune functions. In chronic rhinosinusitis with nasal polyposis, the composition of the epithelium is significantly altered. Loss of ciliated cells and submucosal glands and an increase in basal airway epithelial progenitors leads to loss of innate immune functions and an expansion of proinflammatory potential. Type 2 cytokines play a major role in driving this process.

CONCLUSION

Airway epithelial remodeling in chronic rhinosinusitis is extensive, leading to loss of innate immune function and enhanced proinflammatory potential. The mechanisms driving airway remodeling and its sequelae deserve further attention before restitution of epithelial differentiation can be considered a reasonable therapeutic target.

Key role of the epithelium in chronic upper airways diseases

The respiratory epithelium of the upper airways is a first-line defence against inhaled irritants, pathogens and allergens. It ensures a physical barrier provided by apical junctions and mucociliary clearance to avoid excessive activation of the immune system. The epithelium also forms a chemical and immunological barrier, extensively equipped to protect the airways against external aggressions before the adaptive immune system is required. Under normal circumstances, the epithelium is capable of recovering rapidly after damage. This manuscript reviews these main properties of the upper airway epithelium as well as its reported impairments in chronic inflammatory diseases. The knowledge on normal epithelial functions and their dysregulation in upper airway diseases should help to design new epithelial-targeted treatments.

15-Lipoxygenase 1 in nasal polyps promotes CCL26/eotaxin 3 expression through extracellular signal-regulated kinase activation

BACKGROUND

15-Lipoxygenase 1 (15LO1) is expressed in airway epithelial cells in patients with type 2-high asthma in association with eosinophilia. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also associated with type 2 inflammation and eosinophilia. CCL26/eotaxin 3 has been reported to be regulated by 15LO1 in lower airway epithelial cells. However, its relation to 15LO1 in patients with CRSwNP or mechanisms for its activation are unclear.

OBJECTIVE

We sought to evaluate 15LO1 and CCL26 expression in nasal epithelial cells (NECs) from patients with CRSwNP and healthy control subjects (HCs) and determine whether 15LO1 regulates CCL26 in NECs through extracellular signal-regulated kinase (ERK) activation.

METHODS

15LO1, CCL26, and phosphorylated ERK were evaluated in NECs from patients with CRSwNP and HCs. 15LO1/CCL26 and CCL26/cytokeratin 5 were colocalized by means of immunofluorescence. IL-13-stimulated NECs were cultured at an air-liquid interface with or without 15-lipoxygenase 1 gene (ALOX15) Dicer-substrate short interfering RNAs (DsiRNA) transfection, a specific 15LO1 enzymatic inhibitor, and 2 ERK inhibitors. Expression of 15LO1 and CCL26 mRNA and protein was analyzed by using quantitative RT-PCR, Western blotting, and ELISA.

RESULTS

15LO1 expression was increased in nasal polyp (NP) epithelial cells compared with middle turbinate epithelial cells from patients with CRSwNP and HCs. 15LO1 expression correlated with CCL26 expression and colocalized with CCL26 expression in basal cells of the middle turbinate and NPs from patients with CRSwNP. In primary NECs in vitro, IL-13 induced 15LO1 and CCL26 expression. 15LO1 knockdown and inhibition decreased IL-13-induced ERK phosphorylation and CCL26 expression. ERK inhibition (alone) similarly decreased IL-13-induced CCL26. Phosphorylated ERK expression was increased in NECs from CRSwNP subjects and positively correlated with both 15LO1 and CCL26 expression.

CONCLUSIONS

15LO1 expression is increased in NP epithelial cells and contributes to CCL26 expression through ERK activation. 15LO1 could be considered a novel therapeutic target for CRSwNP.

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.

Aberrant localization of FOXJ1 correlates with the disease severity and comorbidities in patients with nasal polyps

Background

Upper airway inflammatory diseases are associated with abnormal expression of nasal epithelial forkhead-box J1 (FOXJ1) which regulates motile cilia formation. We sought to investigate whether aberrant FOXJ1 localizations correlate with the disease severity and the co-existence of allergic rhinitis (AR) or asthma in patients with nasal polyps (NPs).

Methods

We elucidated localization patterns of FOXJ1 by performing immunofluorescence assays in nasal specimens and cytospin samples from controls and patients with NPs. We also assayed mRNA expression levels of FOXJ1 by using quantitative real-time polymerase chain reaction. Four localization patterns [normal (N), intermediate (I), mislocalization (M), and absence (A)] were defined. A semi-quantitative scoring system was applied for demonstrating FOXJ1 localization in five areas per paraffin section, with individual sections being scored between 0 and 2.

Results

FOXJ1 localization score was significantly higher in samples from NPs than in controls (P < 0.001). Elevated FOXJ1 localization scores and down-regulation of FOXJ1 mRNA levels were observed in NPs with co-existing AR or asthma (all P < 0.05). Moreover, FOXJ1 localization scores positively correlated with Lund–Mackay score (r = 0.362, P = 0.007). Of primary cytospin samples, the mean percentage of patients with FOXJ1 localization patterns N, I, M and A was 15.0%, 3.3%, 53.3% and 28.3% in NPs, and 82.5%, 5.0%, 5.0% and 7.5% in controls, respectively (P < 0.001).

Conclusions

Aberrant localization of FOXJ1 correlates with the severity and co-existence of AR or asthma in patients with NPs, and might be a novel target for assessment and intervention in NPs.

Electronic supplementary material

The online version of this article (10.1186/s13223-018-0296-z) contains supplementary material, which is available to authorized users.

The role of transcriptional factor p63 in regulation of epithelial barrier and ciliogenesis of human nasal epithelial cells

Disruption of nasal epithelial tight junctions (TJs) and ciliary dysfunction are found in patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs), along with an increase of p63-positive basal cells and histone deacetylase (HDAC) activity. To investigate these mechanisms, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were transfected with siRNAs of TAp63 and ΔNp63, treated with the NF-kB inhibitor curucumin and inhibitors of HDACs, and infected with respiratory syncytial virus (RSV). In TERT-HNECs, knockdown of p63 by siRNAs of TAp63 and ΔNp63, induced claudin-1 and -4 with Sp1 activity and enhanced barrier and fence functions. The knockdown of p63 enhanced the number of microvilli with the presence of cilia-like structures. Treatment with curcumin and inhibitors of HDACs, or infection with RSV prevented expression of p63 with an increase of claudin-4 and the number of microvilli. The knockdown or downregulation of p63 inhibited phospho-p38MAPK, and the p38MAPK inhibitor downregulated p63 and upregulated the barrier function. Thus, epithelial barrier and ciliogenesis of nasal epithelium are regulated in a p63-negative manner in normal and upper airway diseases. Understanding of the regulation of p63/p38 MAPK/NF-κB may be important in the therapy for airway allergy and its drug delivery system.

The Role of Periostin in the Occurrence and Progression of Eosinophilic Chronic Sinusitis with Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with different host defence responses. However, whether periostin and vascular endothelial growth factor (VEGF) are similarly impaired in patients with eosinophilic CRSwNP (ENP) and those with non-eosinophilic CRSwNP (nENP) remains unclear. We sought to evaluate the expression and possible modulation of periostin and VEGF, regulated on activation normal T expressed and secreted (RANTES) and eotaxin-2 in the polyp tissues from 30 patients with ENP and from 36 patients with nENP and in middle turbinate tissues from 12 control subjects. We found that ENP tissues exhibited a significantly increased expression of periostin and VEGF compared with tissues from patients with nENP and control subjects (P < 0.05, respectively). Accordingly, the expression of VEGF, RANTES, and eotaxin-2 in ENP fibroblasts was significantly up-regulated after stimulation with up-regulated periostin in vitro, but the expression of VEGF and RANTES was significantly inhibited by stimulation with down-regulated periostin. Our findings suggest that periostin might play an important role in the occurrence and progression of ENP and might be a potential therapeutic target.

Increase of poorly proliferated p63+ /Ki67+ basal cells forming multiple layers in the aberrant remodeled epithelium in nasal polyps

BACKGROUND

Aberrant epithelial remodeling with the ectopic expression of p63 (basal cell markers) is an important pathologic phenomenon seen in chronically inflamed airway epithelium such as in nasal polyps (NPs).

METHODS

Biopsies were obtained from 55 NP patients and 18 healthy controls (inferior turbinate). Among NP patients, 15 were treated with oral and nasal steroids, so that two sets of NP biopsies were taken before and after the treatments. p63, Ki67, type IV β-tubulin, and cell cycle markers were investigated in these specimens.

RESULTS

The number of p63⁺ cells is significantly higher in both hyperplastic (1.53-fold, P < 0.0001) and squamous metaplastic (2.02-fold, P < 0.0001) epithelium from NPs than from healthy controls. There are three types of proliferative basal cells (p63⁺ /Ki67⁺ ) which are in different phases of the cell cycle, such as G1 phase (type I cells), S to G2 phase (type II cells), and mitosis (type III cells). Of importance, some type I cells may arrest after proliferation although they may still be p63⁺ /Ki67⁺ . In healthy epithelium, the ratio of the type I and II cells is almost 50:50. However, less type II cells are found in hyperplastic epithelium (34.85%, P = 0.012) and in squamous metaplastic epithelium (30.77%, P = 0.02) together with the presence of type III cells (3.45%, P = 0.01). These findings were not changed after steroid treatments.

CONCLUSIONS

An increase of poorly proliferated basal cells forming multiple layers, which may stain for basal cell markers but does not form a proper epidermal barrier, is an important histopathologic phenomenon in aberrant remodeled epithelium of NPs.

Differential Expression Patterns of EGF, EGFR, and ERBB4 in Nasal Polyp Epithelium

Epidermal growth factor receptors play an important role in airway epithelial cell growth and differentiation. The current study investigates the expression profiles of EGF, EGFR and ERBB4 in patients with nasal polyps (NP), and their response to glucocorticosteroid (GC) treatment. Fifty patients with NP (40 without GC treatment and 10 with oral GC) and 20 control subjects with septal deviation were recruited into the study. Protein levels of EGF, EGFR, and ERBB4 were evaluated by immune-staining. In healthy nasal epithelium, EGF and EGFR localized within p63⁺ basal cells, while ERBB4 localized within ciliated cells. GC-naïve NP epithelium showed weak expression of EGF in 90% of samples versus 5% of controls. EGFR was significantly increased in the epithelium with basal cell hyperplasia from GC-naïve NPs (78%, 31/40) compared to controls (23%, 4/17). EGFR was also found in some degranulating goblet cells. ERBB4 expression was significantly higher in hyperplastic epithelium from GC-naïve NPs (65%, 26/40) than in controls (6%, 1/17). GC treatment restored the EGF expression and normalized the EGFR and ERBB4 expression in NPs. Differential expression patterns of EGF, EGFR, and ERBB4 are essential in epithelial restitution and remodeling in nasal epithelium.

Ultrastructural regenerating features of nasal mucosa following microdebrider-assisted turbinoplasty are related to clinical recovery

BACKGROUND

The nasal mucosa plays a key role in conditioning the inhaled air and in regulating the immune response. These functions led many authors to recommend mucosal sparing techniques for the surgical management of inferior turbinate hypertrophy. However, the histological modifications of chronic diseases retain the inflammatory activity and prevent the nasal physiology restoration. It has been proved that the basal cells of the nasal mucosa are able to proliferate and to repair after cold-knife incision. The aim of this study was to demonstrate that the healing process after removal of the inferior turbinate mucosa with cold techniques results in a complete structural restoration.

METHODS

A prospective study was performed in 18 patients who underwent Microdebrider inferior turbinoplasty (cold technique). Subjective and objective improvement of nasal patency was evaluated with visual analogue scale, rhinomanometry, videoendoscopy and mucociliary transport test. Pre- and post-operative biopsy specimens were taken from 7 patients to evaluate the healing process. Two samples were taken from two healthy patients as control. The specimens were processed for transmission electron microscopy analysis.

RESULTS

Videoendoscopy showed reduction of lower turbinate after surgery. Nasal patency augmented and no adverse consequences were observed. After 4 months the nasal mucosa showed normal appearance, with restoration of the pseudostratified ciliated pattern, intercellular connections and normal cellular morphology. Fibrosis and submucosal edema disappeared. At longer time after operation (4 years) clinical improvement was confirmed.

CONCLUSIONS

The total removal of the nasal mucosa with cold techniques results in a complete restoration of the normal structure and permanent resolution of the chronic inflammation typical of hypertrophic rhinopathy.

p73 Is Required for Multiciliogenesis and Regulates the Foxj1-Associated Gene Network

We report that p73 is expressed in multiciliated cells (MCCs), is required for MCC differentiation, and directly regulates transcriptional modulators of multiciliogenesis. Loss of ciliary biogenesis provides a unifying mechanism for many phenotypes observed in p73 knockout mice including hydrocephalus; hippocampal dysgenesis; sterility; and chronic inflammation/infection of lung, middle ear, and sinus. Through p73 and p63 ChIP-seq using murine tracheal cells, we identified over 100 putative p73 target genes that regulate MCC differentiation and homeostasis. We validated Foxj1, a transcriptional regulator of multiciliogenesis, and many other cilia-associated genes as direct target genes of p73 and p63. We show p73 and p63 are co-expressed in a subset of basal cells and suggest that p73 marks these cells for MCC differentiation. In summary, p73 is essential for MCC differentiation, functions as a critical regulator of a transcriptome required for MCC differentiation, and, like p63, has an essential role in development of tissues.

T Cell Responses during Acute Respiratory Virus Infection

The T cell response is an integral and essential part of the host immune response to acute virus infection. Each viral pathogen has unique, frequently nuanced, aspects to its replication, which affects the host response and as a consequence the capacity of the virus to produce disease. There are, however, common features to the T cell response to viruses, which produce acute limited infection. This is true whether virus replication is restricted to a single site, for example, the respiratory tract (RT), CNS etc., or replication is in multiple sites throughout the body. In describing below the acute T cell response to virus infection, we employ acute virus infection of the RT as a convenient model to explore this process of virus infection and the host response. We divide the process into three phases: the induction (initiation) of the response, the expression of antiviral effector activity resulting in virus elimination, and the resolution of inflammation with restoration of tissue homeostasis.

Hypoxia-inducible TAp73 supports tumorigenesis by regulating the angiogenic transcriptome

The functional significance of the overexpression of unmutated TAp73, a homologue of the tumour suppressor p53, in multiple human cancers is unclear, but raises the possibility of unidentified roles in promoting tumorigenesis. We show here that TAp73 is stabilized by hypoxia, a condition highly prevalent in tumours, through HIF-1α-mediated repression of the ubiquitin ligase Siah1, which targets TAp73 for degradation. Consequently, TAp73-deficient tumours are less vascular and reduced in size, and conversely, TAp73 overexpression leads to increased vasculature. Moreover, we show that TAp73 is a critical regulator of the angiogenic transcriptome and is sufficient to directly activate the expression of several angiogenic genes.  Finally, expression of TAp73 positively correlates with these angiogenic genes in several human tumours, and the angiogenic gene signature is sufficient to segregate the TAp73(Hi)- from TAp73(Low)-expressing tumours. These data demonstrate a pro-angiogenic role for TAp73 in supporting tumorigenesis, providing a rationale for its overexpression in cancers.

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.

Features of mesenchymal transition in the airway epithelium from chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) defines a group of disorders characterized by persistent inflammation of the sinonasal tract. Epithelial changes and structural remodelling are present, but whether epithelial differentiation is altered remains uncertain.

METHODS

To evaluate the differentiation state of the sinonasal epithelium in CRS, sinonasal biopsies from patients with CRS with nasal polyps (CRSwNP) or CRS without nasal polyps (CRSsNP), or with allergic rhinitis (AR), as compared to controls, were processed by immunohistochemistry and RT-qPCR for terminal differentiation (E-cadherin, high molecular weight cytokeratins (Hmw CK) and CK5, vimentin) and lineage differentiation (ß-tubulin IV+ ciliated cells, MUC5AC+ goblet cells, p63 + basal cells). Findings were correlated with subepithelial fibrosis and clinical CT score.

RESULTS

Expression of E-cadherin was decreased at protein and mRNA levels in CRSwNP and CRSsNP, as compared to controls. Staining for Hmw CKs was also reduced in CRSwNP and CRSsNP, and CK5 mRNA was decreased in CRSwNP. These features were not due to changes in lineage specification, but associated with increases in vimentin-expressing epithelial cells. In addition, vimentin expression correlated with the basement membrane thickening and with CT score, as well as with tissue eosinophils.

CONCLUSION

Features of epithelial dedifferentiation towards a mesenchymal phenotype are observed in CRSwNP and CRSsNP and correlate with airway fibrosis and inflammation.

Reduced growth and proliferation dynamics of nasal epithelial stem/progenitor cells in nasal polyps in vitro

Basal cells in nasal epithelium have stemness/progenitor characters and play essential roles in the epithelial remodeling in nasal polyps (NP). We investigate whether the human nasal epithelial stem/progenitor cells (hNESPCs) from patients with NP are inherently distinct from those obtained from healthy controls. Epithelial basal cells were isolated and cultured for four passages from NP tissues and control nasal mucosa. hNESPCs from controls were stained positively with stem cell marker p63 and KRT5 and presented a consistent high Ki67 expression level over four passages. In contrast, hNESPCs from NP patients showed: i). a reduced growth and proliferation rate at each passage by evaluating colony-forming efficiency and doubling time; ii). a lower percentage of Ki67⁺ cells among p63⁺ cells in the colonies in late passages, which was also confirmed by immunostaining in the NP tissues. Thus reduced growth/proliferation dynamics in hNESPCs from NP could be an important pathological phenomenon in NP development.

Adverse effects of immunosuppressant drugs upon airway epithelial cell and mucociliary clearance: implications for lung transplant recipients

Optimal post-transplantation immunosuppression is critical to the survival of the graft and the patient after lung transplantation. Immunosuppressant agents target various aspects of the immune system to maximize graft tolerance while minimizing medication toxicities and side effects. The vast majority of patients receive maintenance immunosuppressive therapy consisting of a triple-drug regimen including a calcineurin inhibitor, a cell cycle inhibitor and a corticosteroid. Although these immunosuppressant drugs are frequently used after transplantation and to control inflammatory processes, limited data are available with regard to their effects on cells other than those from the immunological system. Notably, the airway epithelial cell is of interest because it may contribute to development of bronchiolitis obliterans through production of pro-inflammatory cytokines. This review focuses the current armamentarium of immunosuppressant drugs used after lung transplantation and their main side effects upon airway epithelial cells and mucociliary clearance.

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

PURPOSE OF REVIEW

To summarize the current knowledge of cellular and molecular mechanisms of nasal epithelial repair and remodeling during physical and pathophysiological conditions.

RECENT FINDINGS

Nasal epithelial repair and remodeling is a highly organized and well coordinated process, involving inflammation, proliferation, differentiation, matrix deposition, and remodeling, and is regulated by a wide variety of growth factors and cytokines. From the in-vivo and in-vitro studies conducted in both human and animal models, undifferentiated basal cells (progenitors) are able to migrate from adjacent epithelium, spread over the denuded basement membrane, and proliferate in injured regions (self-renewal) in necessary (homeostasis) or excessive (hyperplasia) degree. Progenitor cells reorient to an apical-basal polarity, and progressively differentiate into ciliated and nonciliated columnar cells and goblet cells, reconstituting a functional respiratory epithelium after several weeks. This recovery process can be observed during various types and severity of injury, and also in common nasal diseases, including acute viral, allergic, and nonallergic rhinitis, as well as chronic rhinosinusitis with and without nasal polyps.

SUMMARY

Although nearly 10 000 articles about nasal epithelium have been published in the last decade, the mechanisms underlying the nasal epithelial repair are still understood at only a superficial descriptive level. In order to advance rhinology to the next level of a comprehensive knowledge of the orchestrated genetic and molecular processes acting during epithelial repair, combined clinical and experimental studies using sophisticated investigational plans to elucidate the functions of both the protein-coding and regulatory portions of the human genome are required.

Down-regulation of EMP1 is associated with epithelial hyperplasia and metaplasia in nasal polyps

AIMS

The aim of this study was to assess protein and mRNA expression of epithelial membrane protein 1 (EMP1) in the nasal mucosa of patients with nasal polyps (NP), and to determine what changes occur in response to glucocorticosteroid (GC) treatment.

METHODS AND RESULTS

NP tissue was obtained from 55 patients, 18 of whom were treated with nasal GCs (i.e. these 18 patients had NP biopsies taken before and after treatment). Biopsies of inferior turbinate mucosa from 30 healthy subjects were used as controls. Quantitative PCR and immunohistochemistry were performed to determine the expression levels of EMP1. EMP1 mRNA expression was significantly lower (2.77-fold) in tissues from NP patients before GC treatment when compared to controls, but was increased in these patients after GC treatment. EMP1 staining in nasal epithelium co-localized with both basal (p63(+)) and differentiated (CK18(+)) epithelial cells. Their immunoreactivity was significantly greater in controls than NP patients. EMP1 mRNA levels were lower in the epithelium with severe hyperplasia (1.79-fold) or with metaplasia (1.85-fold) as compared to those with mild to moderate hyperplasia or non-metaplastic epithelium, respectively. Positive correlations between EMP1 and other epithelial cell-related gene (e.g. JUN, PTGS2, AREG etc.) mRNAs were observed.

CONCLUSIONS

EMP1 could be a biomarker for aberrant epithelial remodelling and metaplasia in chronic inflammatory upper airway mucosa (e.g. NP).

Gene expression signatures: a new approach to understanding the pathophysiology of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex inflammatory disease with variable disease manifestation. Though external risk factors are associated with development and/or persistence of CRS, the host mucosal response is also important, as nasal epithelium acts as a physical and immune barrier. Under inflammatory stress, the nasal epithelium can undergo injury, followed by a rapid remodeling response ranging from epithelial hyperplasia, to goblet-cell metaplasia, to denudation, loss of cilia, fibrosis, and basement membrane thickening. Identification of gene expression signatures and molecular pathways in CRS pathogenesis have now begun to contribute significantly to a better understanding of the genetic and molecular alterations underlying CRS development and progression. Genetic studies are especially illuminating when multiple gene variants synergize within a permissive environmental context, and are expected to guide development of more effective therapeutic targets for CRS treatment.

Genetics of chronic rhinosinusitis: state of the field and directions forward

The cause of chronic rhinosinusitis (CRS) remains unclear. Study of the genetic susceptibility to CRS might be a valuable strategy to understand the pathogenesis of this burdensome disorder. The purpose of this review is to critically evaluate the current literature regarding the genetics of CRS in a comprehensive fashion. The most promising findings from candidate gene studies include the cystic fibrosis transmembrane conductance regulator gene (CFTR), as well as genes involved in antigen presentation, innate and adaptive immune responses, tissue remodeling, and arachidonic acid metabolism. We also review the few hypothesis-independent genetic studies of CRS (ie, linkage analysis and pooling-based genome-wide association studies). Interpretation of the current literature is limited by challenges with study design, sparse replication, few functional correlates of associated polymorphisms, and inadequate examination of linkage disequilibrium or expression quantitative trait loci for reported associations. Given the relationship of CRS to other airway disorders with well-characterized genetic components (eg, asthma), study of the genetics of CRS deserves increased attention and investment, including the organization of large, detailed, and collaborative studies to advance knowledge of the mechanisms that underlie this disorder.

Expression profiles of regulatory and helper T-cell-associated genes in nasal polyposis

BACKGROUND

Nasal polyposis (NP) is a Th2-skewed inflammatory disorder, but it is unclear what role regulatory T cells (T-reg) play in disease pathology. We investigated the expression profiles of T-reg and T-helper-cell-associated genes and their response to glucocorticosteroid (GC) treatment in Chinese patients with NP.

METHODS

Biopsies were obtained from 29 non-treated NP patients for comparison with inferior turbinates collected from healthy controls. In 13 patients, NP samples were collected both before and after short-term oral GC treatment. Levels of mRNA for T-cell markers were determined by microarray and quantitative PCR. Cellular infiltrates were assessed by histo- and immunohistochemistry.

RESULTS

FOXP3(+) T-reg were increased in GC-naïve NP, and numbers were negatively correlated with eosinophil infiltration. Helios staining was not detected, suggesting that FOXP3(+) cells in NP are not thymus-derived T-reg. Compared with controls, mRNA levels corresponding to T-reg genes were significantly increased in NP (FOXP3, TGFB1, IL10, SMAD3, IL2RA, and JAK3), but transcription factors associated with Th2 (GATA3) or Th17 responses (RORc) were significantly reduced. FOXP3 mRNA levels positively correlated with other T-reg cell markers. Microarray analysis showed that most Th2-related markers (e.g., Eotaxin-1, CCL13, and CCL18) were upregulated in GC-naïve NP vs controls. GC therapy significantly suppressed eosinophilic inflammation in NP, but did not significantly alter the expression levels of T-reg/Th2-associated genes.

CONCLUSIONS

Upregulation of FOXP3(+) -inducible T-reg cells and downregulation of Th2 and Th17 markers in NP indicate a regulatory response occurring at a site of persistent mucosal inflammation. However, immune regulation fails to control the underlying tissue pathology. Expression of T-reg/Th2 markers after GC treatment was unaltered, suggesting that T-cell-driving NP inflammatory mediators are GC resistant.

Airway stem cells: review of potential impact on understanding of upper airway diseases

Epithelial remodeling is a part of our natural defense mechanisms, and includes migration, proliferation, and differentiation of epithelial cells, as well as the interactions between epithelial and stromal cells. It is not yet possible to distinguish between cause and effect during epithelium remodeling, and are there no clear roles for the many factors involved in respiratory infectious and inflammatory diseases due to a lack of critical information about epithelial cell responses. Most reported data are from lower airway studies or animal models. Therefore, research based on human nasal epithelial stem/progenitor cells can illuminate the pathophysiology of nasal airway disease from a different, more specific perspective. In this review, we discuss epithelial stem/progenitor cell research throughout the airway, with special attention to phenotypes and characterization of these cells from the nasal airway. Recently, we have isolated and cultured P63-positive human epithelial stem/progenitor cells from turbinate biopsies of healthy volunteers and from inflamed mucosa of patients with chronic rhinosinusitis with and without nasal polyposis. These cells propagate in serum-free, growth factor-supplemented, Dulbecco's modified Eagle's medium/F12 media, on either human fibroblast or 3T3 feeder layers. Self-renewal, proliferation, and differentiation potential at an air-liquid interface are being investigated to understand the molecular pathways underlying nasal inflammation. This in vitro culture system for nasal epithelial regeneration will allow molecular studies of human nasal epithelial cell interactions, differentiation, and repair, as well as responses to both environmental agents and to potential anti-inflammatory treatments.

Advances in upper airway diseases and allergen immunotherapy in 2011

The purpose of this review is to highlight recently published important articles on upper airway diseases and allergen immunotherapy. We review articles on rhinitis, sinusitis, conjunctivitis, and immunotherapy. New insights into epidemiology, pathophysiology, diagnosis, and therapy are described for each of the above diseases.

New role of microRNA: carcinogenesis and clinical application in cancer

MicroRNA (miRNA) is a cluster of small non-encoding RNA molecules of 21-23 nucleotides in length, which controls the expression of target gene at the post-transcriptional level. Recent researches have indicated that miRNA plays an essential role in carcinogenesis, such as affecting the cell growth, differentiation, apoptosis, and cell cycle. Nowadays, multiple promising roles of miRNA involved in carcinogenesis are emerging, and it is shown that miRNA closely relates to the process of epithelial-mesenchymal transition (EMT), the regulation of cancer stem cells (CSCs), the development of tumor invasion and migration. miRNA also acts as a biomarker stably expressed in serum and provides new target for molecular target therapy of various cancers. The aim of this review is to illustrate the new role of miRNA in carcinogenesis and highlight the new prospects of miRNA in cancer clinical application, such as in serological diagnosis and molecular-targeted therapeutics.