Quantitative study of nasal secretory cells in normal subjects and patients with chronic sinusitis

Age-Related Increase of Collagen/Fibrin Deposition and High PAI-1 Production in Human Nasal Polyps

Objective: Our previous studies showed an age-related increased prevalence of nasal polyps (NP) and reduced production of S100A8/9 in elderly patients with chronic rhinosinusitis with NP (CRSwNP). In this study, we investigated an unbiased age-related gene expression profile in CRSwNP subjects and healthy controls, and further identified the differences in their tissue remodeling. Methods: Microarrays using NP and uncinate tissues from health controls (elderly, age ≥65 vs. non-elderly, age 18-49) were performed, and differentially regulated genes were analyzed. Quantitative real-time PCR (qPCR), Immunostaining, Periodic acid-Schiff (PAS), trichrome staining, Western blot, and ELISA were performed for further investigation. Results: Microarrays identified differentially expressed genes according to disease and age; 278 in NP vs. controls, 75 in non-elderly NP vs. non-elderly controls, and 32 in elderly NP vs. elderly controls. qPCR confirmed that the PLAT gene was downregulated and the SERPINB2 gene upregulated in NP vs. controls. The serous glandular cell-derived antimicrobial protein/peptide-related genes such as BPIFB3, BPIFB2, LPO, and MUC7 were remarkably reduced in NP, regardless of age. SERPINE1 gene (plasminogen activator inhibitor-1, PAI-1) expression was significantly increased in elderly NP versus elderly controls. IHC and western blot confirmed significantly decreased production of MUC7 and LPO in NP versus controls. There was a trend of age-related reduction of submucosal gland cells in normal controls. Trichrome and immunofluorescence staining demonstrated an age-related increase of collagen and fibrin deposition in NP, consistent with increased PAI-1 production. Conclusion: This study demonstrated age-related differential glandular remodeling patterns and fibrosis in NP and normal controls. PAI-1 expression was significantly increased in elderly NP versus elderly controls, suggesting PAI-1 as a potential treatment target in elderly NP.

Septum submucosal glands exhibit aberrant morphology and reduced mucin production in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is characterized by significant accumulation and thickening of mucus in the sinonasal cavities. One contributor of aberrant mucus production and impaired mucociliary clearance (MCC) is altered function of the sinonasal submucosal glands (SMGs), yet contributions of SMGs to upper airway disease initiation and progression remain unknown. The objective of this study was to characterize the morphology and secretory cell identities of the nasal septum SMGs in both healthy and CRS adults.

METHODS

Biopsies from adult participants with CRS without nasal polyps (CRSsNP, n = 4), CRS with nasal polyps (CRSwNP, n = 8), and non-CRS controls (n = 14) were collected from the posterior septum. Glandular morphology and mucus markers were investigated using histological techniques and high-resolution confocal microscopy.

RESULTS

Analysis revealed a significant decrease in gland density in the posterior septum of CRSsNP (28% ± 6.15%) and CRSwNP (23% ± 3.09%) compared to control participants (53% ± 1.59%, p < 0.0001). Further analysis of the CRS SMG secretory function revealed an overall decrease in Mucin 5B+ gland mucus being produced. Dilated and cystic ductal structures filled with inspissated mucus were also common to CRS glands.

CONCLUSION

Here, we describe a significant alteration in SMG structure and function in the adult CRS posterior septum suggesting reduced gland contribution to MCC. The SMGs of both the nose and sinuses may represent targets for future therapeutic approaches.

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.

Mucociliary Transport Function and Damage of Ciliated Epithelium

The influence of epithelial damage on mucociliary transport was studied in relation to the amount of mucus. The mucosal epithelium of mucus-depleted frog palate was dissected and mounted on a plastic plate. Mechanical damages were created on the frog mucosa by pressing a different thickness of boards (2, 3, 5, and 8 mm). Two different amounts of frog mucus (7.9 L [small amount of mucus {S-mucus}]) and 51.0 L [large amount of mucus {L-mucus}])were applied on the frog mucosa with and without mucosal damage. There was no difference in mucociliary transport rate (MTR) on undamaged frog mucosa between S-mucus and L-mucus. However, on the damaged mucosa, MTR of S-mucus was significantly decreased compared with that of L-mucus. Moreover, capability of mucus transportation across the mucosal damage was significantly lower in S-mucus than in L-mucus. Results indicate that the larger the mucus amount becomes, the more the mucus travels the damaged epithelium. Moreover, MTR of L-mucus was decreased with increasing the degree of epithelial damage. This study indicates that the degree of loss of cilia is an important factor of mucociliary deceleration. (American Journal of Rhinology 16, 215–219, 2002)

A slippery slope: On the origin, role and physiology of mucus

The mucosa of the gastrointestinal tract, eyes, nose, lungs, cervix and vagina is lined by epithelium interspersed with mucus-secreting goblet cells, all of which contribute to their unique functions. This mucus provides an integral defence to the epithelium against noxious agents and pathogens. However, it can equally act as a barrier to drugs and delivery systems targeting epithelial passive and active transport mechanisms. This review highlights the various mucins expressed at different mucosal surfaces on the human body, and their role in creating a mucoid architecture to protect epithelia with specialized functions. Various factors compromising the barrier properties of mucus have been discussed, with an emphasis on how disease states and microbiota can alter the physical properties of mucus. For instance, Akkermansia muciniphila, a bacterium found in higher levels in the gut of lean individuals induces the production of a thickened gut mucus layer. The aims of this article are to elucidate the different physiological, biochemical and physical properties of bodily mucus, a keen appreciation of which will help circumvent the slippery slope of challenges faced in achieving effective mucosal drug and gene delivery.

Risk factors for nasal bleeding in patients undergoing transnasal gastrointestinal endoscopy

Transnasal endoscopy is widely used in screening for upper gastrointestinal lesions because of less associated pain. Nasal bleeding is the most severe adverse effect, but specific risk factors have not been identified. The aim of this study is to identify risk factors for nasal bleeding during transnasal endoscopy. Nasal bleeding occurred in 160/3035 (5.3%) of patients undergoing transnasal endoscopy as part of health checkups. Patient data were retrospectively evaluated including anthropometric, medical, and life-style parameters with multiple logistic regression analysis. Multiple logistic regression revealed that nasal bleeding was significantly associated with age in decades [odds ratio/10 years 0.78, 95% confidence interval (CI) 0.63-0.97, p = 0.027], female gender (2.15, 95% CI 1.48-3.12, p < 0.001), a history of previous upper gastrointestinal endoscopy (0.55, 95% CI 0.36-0.82, p = 0.004), and chronic/allergic rhinitis (0.60, 95% CI 0.36-0.98, p = 0.043). Other factors including the use of antiplatelet and/or anticoagulant drugs were not significantly associated with nasal bleeding. Female and young patients are significantly associated with an increased risk of bleeding from transnasal endoscopy, but antiplatelet and/or anticoagulant medications and a history of chronic/allergic rhinitis may not be associated.

Density of Middle Turbinate Subepithelial Mucous Glands in Patients with Chronic Rhinosinusitis

OBJECTIVE: Histologic changes have not been systematically assessed in chronic rhinosinusitis. Quantitative histochemical studies evaluated the extent of sinus disease and gland density in the middle turbinates.

STUDY DESIGN AND SETTING: Sinus computed tomography scans of 34 patients with chronic rhinosinusitis were retrospectively graded 0 to IV according to the May classification. Middle turbinates from patients with chronic rhinosinusitis (n = 46) and normal patients (n = 7) were harvested during endoscopic sinus surgery. The areas of Alcian blue-stained glands were assessed in paraffin sections using a computer-assisted microscopy video system.

RESULTS: Alcian blue-stained glands occupied 7.94% of normal mucosa. The staining in all grade III rhinosinusitis subjects was increased to 12.94% ( P < 0.01). In contrast, grade IV pansinusitis was associated with nasal polyposis (6 of 6) with decreased gland area (3.04%, P < 0.01). When polyp patients were excluded from grade III rhinosinusitis, the Alcian blue-staining area was 17.68% ( P < 0.01).

CONCLUSIONS: Distinct polypoid and glandular histopathologic patterns are present in chronic rhinosinusitis.

Increased expression of hCLCA1 in chronic rhinosinusitis and its contribution to produce MUC5AC

OBJECTIVES/HYPOTHESIS

Mucus hypersecretion is a hallmarks of chronic rhinosinusitis. The expression of MUC5AC, a major respiratory mucin gene, is increased in chronic rhinosinusitis. The mechanisms inducing mucus hypersecretion have not been fully evaluated in chronic rhinosinusitis. Human Ca²⁺ -activated Cl- channel 1 (hCLCA1) is implicated in the regulation of mucus production, airway fluid, and electrolyte transport. The present study objectives was to investigate the expression of hCLCA1 in chronic rhinosinusitis and evaluate whether its level is altered by stimulation with type 1 T helper (Th1) and Th2 cytokines, and to determine the possible role of hCLCA1 on the regulation of mucin 5AC (MUC5AC) production.

STUDY DESIGN

Controlled prospective study.

METHODS

The expression of hCLCA1 and MUC5AC in normal and inflammatory ethmoid mucosa was determined by real-time polymerase chain reaction, immunohistochemistry, and Western blot. In cultured cells, the expression of hCLCA1 and MUC5AC was measured after stimulation with Th1 and Th2 cytokines. In a supernatant, the MUC5AC level was analyzed using enzyme-linked immunosorbent assay after treatment with niflumic acid.

RESULTS

The levels of hCLCA1 and MUC5AC were increased in chronic rhinosinusitis, irrespective of nasal polyp presence, where they were distributed in superficial epithelial cells and submucosal glands. In cultured cells treated with interleukin (IL)-9, IL-4, IL-13, tumor necrosis factor-α, transforming growth factor-β, interferon-γ, and IL-1β, the expression of hCLCA1 and MUC5AC was increased. In cells treated with niflumic acid, the production of MUC5AC was inhibited.

CONCLUSIONS

The current findings indicate that the expression of hCLCA1 is increased in chronic rhinosinusitis and may be regulated by Th1 and Th2 cytokines, possibly contributing to the production of MUC5AC.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:E347-E355, 2016.

Correlation analysis of prognostic and pathological features of patients with chronic sinusitis and nasal polyps following endoscopic surgery

The aim of this study was to evaluate the therapeutic value of pathological indicators to predict the efficacy of endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis (CRS) with nasal polyps. A total of 53 patients with CRS with nasal polyps, who had undergone endoscopic surgery at least one year before, were surveyed for their clinical symptoms. Surgical specimen biopsies were consulted and related pathological indicators were measured. The association between the main symptoms of CRS with nasal polyps following ESS and pathological indicators were statistically analyzed. The main symptoms of patients with CRS with nasal polyps following ESS were nasal congestion, thick nasal discharge, rhinorrhea or sneezing. Goblet cells are associated with the symptoms of sneezing and thick nasal discharge, pathological gland formation is associated with dizziness, and the degree of tissue edema is associated with post-nasal discharge (P<0.05). Pathological indicators aid the prediction of the efficacy of nasal ESS in patients with CRS with nasal polyps.

Proteomics of nasal mucus in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is among the three most common chronic diseases in North America. The area of proteomics research is providing tremendous insight into the mechanisms of a variety of physiological processes and disease states. The purpose of this study was to evaluate qualitative and quantitative differences in protein content of nasal mucus in patients with chronic hypertrophic sinusitis with nasal polyposis when compared with control subjects.

METHODS

A case-control study was performed in a tertiary academic center. Nasal mucus was collected from four patients with CRS and nasal polyposis as well as four control subjects. The protein content was digested using proteolytic enzymes, labeled with iTRAQ reagents, and subjected to mass spectrometry (MS) analysis.

RESULTS

A total of 35 proteins were identified, many of which were related to innate and acquired immunity. Lysozyme C precursor was found to be down-regulated by a ratio (R) of 0.65 (p = 0.016) in CRS patients, as was Clara cell phospholipid-binding protein (R = 0.23; p = 0.0018), and antileukoproteinase 1 (R = 0.47; p < 0.0001). A detailed analysis and characterization of the protein isolates is outlined.

CONCLUSION

The field of proteomics has great potential in leading to a better understanding of the mechanism of the disease process in CRS. Differences in the expression of proteins related to regulation of immune cells and mediators merit additional investigation.

Inflammatory mechanisms and remodeling in chronic rhinosinusitis and nasal polyps

Chronic rhinosinusitis (CRS) is presently classified into two subgroups: CRS without and CRS with nasal polyps. A variety of inflammatory mediators, including cytokines and chemokines, as well as adhesion molecules and matrix metalloproteinases, are upregulated in both subgroups of CRS; remodeling is also observed in both. However, there are also characteristic differences. Whereas CRS without nasal polyps has more neutrophilic infiltration, in CRS with nasal polyps (especially when associated with allergy/asthma) eosinophil infiltration is strikingly increased. Although several features of remodeling (eg, squamous metaplasia, basement membrane thickening, collagen deposition, hyperplasia of mucous glands, and goblet cells) are features seen in both subgroups of CRS, epithelial shedding as observed in asthma is not seen in either subgroup. Furthermore, pseudocyst formation seen in CRS with nasal polyps is not seen in CRS without nasal polyps.

Immunohistochemical analyses of MUC5AC mucin expression in sinus mucosa of children with sinusitis and controls

OBJECTIVES

The purpose of this study was to analyze MUC5AC protein expression in sinus mucosal specimens of children with and without chronic sinusitis.

METHODS

Morphometric, histologic, and immunohistochemical analyses were carried out on sinus mucosa of 7 children with chronic sinusitis and 6 children without sinusitis.

RESULTS

MUC5AC protein was expressed in a subset of goblet cells in the surface epithelium, but not in the submucosal glands in either pediatric population. The number of goblet cells that expressed MUC5AC mucin was not significantly different in patients with and without chronic sinusitis. All specimens had similar numbers of goblet cells in the surface epithelium.

CONCLUSIONS

The data demonstrate that neither goblet cell hyperplasia nor increased MUC5AC expression occurs in the sinus mucosa of children with chronic sinusitis. This suggests that in contrast to asthma, in which goblet cell hyperplasia is present in the lower respiratory tract, mucus hypersecretion in pediatric chronic sinusitis may involve other secretory cells, eg, submucosal glandular cells, and mucins secreted by these glandular cells.

The new histologic classification of chronic rhinosinusitis

Two histologic patterns of disease are found in chronic rhinosinusitis. The first is dominated by eosinophilia and polypoid changes. Glandular hyperplasia and hypertrophy characterize the second. We present the evidence supporting the existence of these two patterns of disease and link these histologic patterns to the larger pathophysiologic processes that drive them. This histologic classification should be acknowledged both in the clinical setting and in laboratory research of chronic rhinosinusitis.

Tissue reparative effects of macrolide antibiotics in chronic inflammatory sinopulmonary diseases

It is well established that macrolide antibiotics are efficacious in treating sinopulmonary infections in humans. However, a growing body of experimental and clinical evidence indicates that they also express distinct salutary effects that promote and sustain the reparative process in the chronically inflamed upper and lower respiratory tract. Unlike the anti-infective properties, these distinct effects are manifested at lower doses, usually after a relatively prolonged period (weeks) of treatment, and in the absence of an identifiable, viable pathogen. Long-term, low-dose administration of macrolide antibiotics has been used most commonly for sinusitis, diffuse panbronchiolitis, asthma, bronchiectasis, and cystic fibrosis. It is associated with down-regulation of nonspecific host inflammatory response to injury and promotion of tissue repair. Although large-scale trials are lacking, the prolonged use of these drugs has not been associated with emergence of clinically significant bacterial resistance or immunosuppression. Long-term, low-dose administration of 14- and 15-membered ring macrolide antibiotics may represent an important adjunct in the treatment of chronic inflammatory sinopulmonary diseases in humans.

Differential properties of mucous glycoproteins in rat nasal epithelium. A comparison between allergic inflammation and lipopolysaccharide stimulation

To examine the differential properties of mucous glycoproteins, we produced hypertrophic and metaplastic changes in goblet cells of rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats, and by intranasal lipopolysaccharide (LPS) instillation. The epithelial mucosubstance was quantitatively examined by alcian blue-periodic acid-Schiff (AB-PAS) and lectin histochemistry. The newly produced mucin after OVA challenge or LPS instillation contained a high amount of sulfomucin and a low amount of neutral glycoprotein: LPS-induced mucin contained more sulfomucin (70.1% of total) and less neutral glycoprotein (8.6%) than OVA-induced mucin (sulfomucin, 33.6%; neutral glycoprotein, 41.8%; p < 0.01). Four of the lectins stained some of the mucosubstance, indicating the presence of galactose-N-acetylgalactosamine, alpha2,3- and alpha2,6-linked sialic acid-galactose, and fucose residues. After LPS instillation, the reactivity was higher for galactose-N-acetylgalactosamine (64.8% of total) and alpha2,3-linked sialic acid-galactose (75.8%) than after saline instillation (3.5 and 19.1%, respectively) or OVA challenge (5.8 and 32.3%; p < 0.05). OVA challenge did not induce the alteration of terminal sugar residues. A 2-fold increase in mucin mRNA (rat Muc5ac) expression was induced after LPS instillation or OVA challenge, compared with animals treated with saline instillation (p < 0.05). These results indicate that mucin mRNA expression (for peptide backbone) increases similarly after LPS instillation or OVA challenge; however, carbohydrate compositions of newly produced mucin are different between the two groups.

Quantitative analysis of mucin and lectin in maxillary sinus fluids in patients with acute and chronic sinusitis

OBJECTIVES

Sinusitis is characterized by quantitative and qualitative changes in mucus biosynthesis that contribute to sinus disease. In general, patients with acute sinusitis complain of purulent rhinorrhea, whereas those with chronic sinusitis complain of mucoid or mucopurulent rhinorrhea Locally produced mucin largely contributes to the high viscoelasticity of mucus in sinusitis. In this study, the authors attempt to quantify the concentrations of mucin and lectin in the maxillary sinus fluids from these patients.

STUDY DESIGN

To assess the concentrations of mucin and lectin in aspirates of 11 acutely and 11 chronically inflamed maxillary sinuses, the concentration of mucin was measured by enzyme-linked immunosorbent assay (ELISA) and that of lectin by sandwiched enzyme-linked lectin assay (ELLA).

RESULTS

The concentrations of mucin and lectin that were measured using monoclonal antibodies (HCS 4, HCS 14, and HCS 18) and Ulex europaeus agglutinin-1 (UEA-1) in chronic sinusitis were higher than those in acute sinusitis. The concentration of total protein in chronic sinusitis was lower than that in acute sinusitis. Each mucin and lectin versus total protein ratio in chronic sinusitis was higher than that in acute sinusitis.

CONCLUSIONS

These data suggest that hypersecretion in chronic sinusitis may result from locally increased mucin production. Comprehension of this mechanism may be a strategy to prevent the viscous cycle of paranasal sinus fluids in chronic sinusitis.

Inferior turbinate goblet cell secretion in patients with perennial allergic and nonallergic rhinitis

Perennial rhinitis is clinically associated with a significant increase in nasal mucus secretion. Moreover, it has already been established that the number of goblet cells, in the inferior turbinates of patients with perennial allergic and nonallergic rhinitis, does not differ from that of normal subjects. Thus a question is raised, whether the above-mentioned phenomenon is ascribed exclusively to submucosal glandular activity, or may also be a result of a nonhyperplastic increase of goblet cell functional activity. This study was conducted to assess inferior turbinate goblet cell mucus secretion in a cohort of patients with perennial allergic and nonallergic rhinitis compared with normal controls. A semiquantitative morphometric method was used to examine goblet cell mucus secretion in sections stained with Alcian blue and periodic acid Schiff. Mucus secretion in each section was established in terms of secretory ratio, calculated as the number of secreting goblet cells divided by the number of nonsecreting ones. The mean secretory ratio of patients with perennial allergic (n = 11) and nonallergic rhinitis (n = 23) was 0.89 and 0.57, respectively, compared to controls (n = 10) 0.25. Statistical analysis confirmed that the secretory ratio of patients with perennial allergic rhinitis was significantly higher than that of the control group. No significant difference prevailed between patients with perennial nonallergic rhinitis and controls, as well as between allergic and nonallergic patients. Based on the results of the study, a basal state of nasal goblet cell mucus secretion in nonstimulated healthy people was established. Furthermore, it was concluded that the enhancement in mucus discharge, from the inferior turbinate goblet cells of patients with perennial allergic rhinitis, was attributed to a nonhyperplastic increase of nasal goblet cell functional activity.