Association of Inflammation Mediator in Mucosal and Tissue of Chronic Rhinosinusitis with Recurrent Nasal Polyp

Biotherapy and treatment of adult primary chronic rhinosinusitis with nasal polyps: Cellular and molecular bases

The present article reviews the molecular and cellular mechanisms involved in the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwCRSwNP) and underlying the action mechanisms of biotherapies. Biotherapy uses substances naturally produced by the organism or their specific antagonists targeting a proinflammatory mechanism. CRSwCRSwNP is a form of chronic rhinosinusitis (CRS), which is classically subdivided in to 2 types according to the presence of polyps. In recent years, the concept of endotypes emerged, with a more exhaustive definition of the types of CRS according to inflammatory mechanism, with a view to developing personalized treatments. CRSwNP pathophysiology is poorly understood. Polyps arise from a primary epithelial lesion in a context of chronic local inflammation, mainly type 2 in Europe, implicating eosinophils, IgE, Th2 cytokines (IL-4/IL-13, IL-5) and T and B cells. Biotherapy seems promising in CRSwNP. The present review details the various pathophysiological pathways underlying the action mechanisms of biotherapies, and the various published studies, assessing efficacy and mode of action in the treatment of CRSwNP.

Nuclear Factor κB/MicroRNA-155 Upregulates the Expression Pattern of Cytokines in Regulating the Relapse of Chronic Sinusitis with Nasal Polyps and the Underlying Mechanism of Glucocorticoid

Background

The aim of this study was to explore the upregulated nuclear factor κB (NF-κB)/microRNA-155 (miR-155) in regulating inflammatory responses and relapse of chronic rhinosinusitis (CRS) with nasal polyps (NP), which underlies the molecular mechanism of glucocorticoid treatment.

Material/Methods

The study recruited 25 patients with eosinophilic (Eos) CRSwNP, 25 patients with Non-Eos CRSwNP, 25 patients with CRS without NP (CRSsNP) and 30 patients with nasal septum deviation (control group). The expression of NF-κB/miR-155 and inflammatory cytokines was detected in epithelial tissue specimens. Additionally, a mouse model of Eos CRSwNP was established, and the mice were treated by NF-κB inhibitor, miR-155 antagomir, or dexamethasone (DEX) to explore the role of NF-κB/miR-155 and the anti-inflammatory effects of glucocorticoid treatment.

Results

Results showed that the expression level of NF-κB/miR-155 was significantly elevated in the Eos CRSwNP group, accompanied by the upregulation of cytokines: tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-4, IL-5 (P<0.05) compared with the control group, the CRSsNP group or the Non-Eos CRSwNP group. The upregulation of NF-κB/miR-155 increased inflammatory mediator cyclooxygenase2 (COX2) while decreasing anti-inflammatory mediator Src homology-2 domain-containing inositol 5-phosphatase 1 (SOCS1), which resulted in the aberrant expression pattern of cytokines in the mice model. DEX treatment inhibited the expression of cytokines and decreased the relapse rate of Eos CRSwNP via inhibiting NF-κB/miR-155 (P<0.05).

Conclusions

The upregulation of NF-κB/miR-155 was crucial in mediating the aberrant expression of inflammatory cytokines in Eos CRSwNP. This molecular mechanism is a concern with the high relapse rate of Eos CRSwNP. However, glucocorticoid treatment inhibited the relapse of CRSwNP via downregulation of NF-κB/miR-155.

Pathogenesis of chronic rhinosinusitis with nasal polyps: role of IL-6 in airway epithelial cell dysfunction

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by an alteration in airway epithelial cell functions including barrier function, wound repair mechanisms, mucociliary clearance. The mechanisms leading to epithelial cell dysfunction in nasal polyps (NPs) remain poorly understood. Our hypothesis was that among the inflammatory cytokines involved in NPs, IL-6 could alter epithelial repair mechanisms and mucociliary clearance. The aim of this study was to evaluate the in vitro effects of IL-6 on epithelial repair mechanisms in a wound repair model and on ciliary beating in primary cultures of Human Nasal Epithelial Cells (HNEC).

Methods

Primary cultures of HNEC taken from 38 patients during surgical procedures for CRSwNP were used in an in vitro model of wound healing. Effects of increasing concentrations of IL-6 (1 ng/mL, 10 ng/mL, and 100 ng/mL) and other ILs (IL-5, IL-9, IL-10) on wound closure kinetics were compared to cultures without IL-modulation. After wound closure, the differentiation process was characterized under basal conditions and after IL supplementation using cytokeratin-14, MUC5AC, and β_IV tubulin as immunomarkers of basal, mucus, and ciliated cells, respectively. The ciliated edges of primary cultures were analyzed on IL-6 modulation by digital high-speed video-microscopy to measure: ciliary beating frequency (CBF), ciliary length, relative ciliary density, metachronal wavelength and the ciliary beating efficiency index.

Results

Our results showed that: (i) IL-6 accelerated airway wound repair in vitro, with a dose–response effect whereas no effect was observed after other ILs-stimulation. After 24 h, 79% of wounded wells with IL6-100 were fully repaired, vs 46% in the IL6-10 group, 28% in the IL6-1 group and 15% in the control group; (ii) specific migration analyses of closed wound at late repair stage (Day 12) showed IL-6 had the highest migration compared with other ILs (iii) The study of the IL-6 effect on ciliary function showed that CBF and metachronal wave increased but without significant modifications of ciliary density, length of cilia and efficiency index.

Conclusion

The up-regulated epithelial cell proliferation observed in polyps could be induced by IL-6 in the case of prior epithelial damage. IL-6 could be a major cytokine in NP physiopathology.