Role of Eotaxin-3 in Chronic Rhinosinusitis with Nasal Polyps

Fractional Exhaled Nitric Oxide as a Marker of Mucosal Inflammation in Chronic Rhinosinusitis

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a cost-effective, noninvasive point-of-care test that has proven valuable in identifying patients with lower airway inflammation and predicting the likelihood of responsiveness to inhaled corticosteroid therapy in asthma. The utility of FeNO in upper airway disease, specifically in CRS, remains to be determined.

OBJECTIVE

The goal of this study was to test whether FeNO could serve as a noninvasive marker of sinonasal mucosal inflammation in CRS patients.

METHODS

FeNO was obtained using a nitric oxide analyzer (NIOX VERO) as well as nasal mucus, the 22-item Sinonasal Outcome Test (SNOT-22), University of Pennsylvania Smell Identification Test (UPSIT), and Lund-Kennedy endoscopic scores concurrently in 112 CRS patients. Nasal mucus was analyzed for cytokine expression using solid-phase sandwich ELISA. Linear regression with Spearman correlation coefficient was used to determine strength of relationship between variables.

RESULTS

CRS patients showed elevated FeNO levels with asthma (47.12 ± 5.21 ppb) or without asthma (43.24 ± 9.810 ppb). Elevated FeNO levels correlated with sinonasal mucosal inflammation, as determined by increased levels of CCL26 and TNFα in nasal mucus obtained from CRS patients. Furthermore, elevated FeNO levels selectively correlated with worsened SNOT-22 nasal symptoms (P = 0.03) and Lund-Kennedy endoscopic scores (P = 0.007), but did not correlate with UPSIT scores.

CONCLUSIONS

FeNO levels correlated with increased sinonasal mucosal inflammation and symptom severity in CRS regardless of asthma status. FeNO measurements may serve as a quick and noninvasive marker in evaluating CRS patients.

Physiological and pathophysiological roles of acidic mammalian chitinase (CHIA) in multiple organs

Acidic mammalian chitinase (CHIA) belongs to the 18-glycosidase family and is expressed in epithelial cells and certain immune cells (such as neutrophils and macrophages) in various organs. Under physiological conditions, as a hydrolase, CHIA can degrade chitin-containing pathogens, participate in Type 2 helper T (Th2)-mediated inflammation, and enhance innate and adaptive immunity to pathogen invasion. Under pathological conditions, such as rhinitis, ocular conjunctivitis, asthma, chronic atrophic gastritis, type 2 diabetes, and pulmonary interstitial fibrosis, CHIA expression is significantly changed. In addition, studies have shown that CHIA has an anti-apoptotic effect, promotes epithelial cell proliferation and maintains organ integrity, and these effects are not related to chitinase degradation. CHIA can also be used as a biomolecular marker in diseases such as chronic atrophic gastritis, dry eye, and acute kidney damage caused by sepsis. Analysis of the authoritative TCGA database shows that CHIA expression in gastric adenocarcinoma, liver cancer, renal clear cell carcinoma and other tumors is significantly downregulated compared with that in normal tissues, but the specific mechanism is unclear. This review is based on all surveys conducted to date and summarizes the expression patterns and functional diversity of CHIA in various organs. Understanding the physiological and pathophysiological relevance of CHIA in multiple organs opens new possibilities for disease treatment.

Proton pump inhibitors decrease eotaxin-3/CCL26 expression in patients with chronic rhinosinusitis with nasal polyps: Possible role of the nongastric H,K-ATPase

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is often characterized by tissue eosinophilia that is associated with poor prognosis. Recent findings that proton pump inhibitors (PPIs) directly modulate the expression of eotaxin-3, an eosinophil chemoattractant, in patients with eosinophilic diseases suggest therapeutic potential for PPIs in those with CRSwNP.

OBJECTIVE

We assessed the effect of type 2 mediators, particularly IL-13 and eotaxin-3, on tissue eosinophilia and disease severity in patients with chronic rhinosinusitis (CRS). Further investigation focused on PPI suppression of eotaxin-3 expression in vivo and in vitro, with exploration of underlying mechanisms.

METHODS

Type 2 mediator levels in nasal tissues and secretions were measured by using a multiplex immunoassay. Eotaxin-3 and other chemokines expressed in IL-13-stimulated human sinonasal epithelial cells (HNECs) and BEAS-2B cells with or without PPIs were assessed by using ELISA, Western blotting, real-time PCR, and intracellular pH imaging.

RESULTS

Nasal tissues and secretions from patients with CRSwNP had increased IL-13, eotaxin-2, and eotaxin-3 levels, and these were positively correlated with tissue eosinophil cationic protein levels and radiographic scores in patients with CRS (P < .05). IL-13 stimulation of HNECs and BEAS-2B cells dominantly induced eotaxin-3 expression, which was significantly inhibited by PPIs (P < .05). Patients with CRS taking PPIs also showed lower in vivo eotaxin-3 levels compared with those without PPIs (P < .05). Using intracellular pH imaging and altering extracellular K⁺, we found that IL-13 enhanced H⁺,K⁺-exchange, which was blocked by PPIs and the mechanistically unrelated H,K-ATPase inhibitor, SCH-28080. Furthermore, knockdown of ATP12A (gene for the nongastric H,K-ATPase) significantly attenuated IL-13-induced eotaxin-3 expression in HNECs. PPIs also had effects on accelerating IL-13-induced eotaxin-3 mRNA decay.

CONCLUSION

Our results demonstrated that PPIs reduce IL-13-induced eotaxin-3 expression by airway epithelial cells. Furthermore, mechanistic studies suggest that the nongastric H,K-ATPase is necessary for IL-13-mediated epithelial responses, and its inhibitors, including PPIs, might be of therapeutic value in patients with CRSwNP by reducing epithelial production of eotaxin-3.

Nasal fluid release of eotaxin-3 and eotaxin-2 in persistent sinonasal eosinophilic inflammation

BACKGROUND

The aim of the present study was to measure eotaxin-3 (CCL26) and eotaxin-2 (CCL24) in nasal lavage fluid of patients with different forms of chronic sinonasal eosinophilic inflammation to evaluate their role in the pathophysiology of nasal hypereosinophilia.

METHODS

The study was an analytic cross-section study, level of evidence 3b. Patients (n = 80) with nasal hypereosinophilia were randomly recruited and grouped in the following categories: persistent allergic rhinitis (AR) (n = 25), nonallergic rhinitis with eosinophilia syndrome (NARES) (n = 30), and chronic rhinosinusitis with polyps (CRSwNP) (n = 25). Non-rhinitic volunteers (n = 20) were recruited as controls. CCL24 and CCL26 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) Quantikine Human Immunoassays (R&D Systems, Minneapolis, MN) in nasal lavage fluids. Differential cell counts were performed by microscopic cytological examination of nasal tissue scraped from the inferior turbinate.

RESULTS

Mean CCL26 levels were significantly higher (p < 0.05) in AR and in NARES (132.0 pg/mL and 187.63 pg/mL, respectively) than in the control group (13.5 pg/mL); in patients with CRSwNP, CCL26 values were increased compared to controls even though the difference was not statistically significant (58.9 pg/mL vs 16.5 pg/mL). Mean CCL24 levels measured in AR, NARES, and CRSwNP were significantly increased (p < 0.05) compared to controls (96.7 pg/mL, 135.4 pg/mL, and 107.0 pg/mL, respectively, vs 32.2 pg/mL). Moreover, we observed a significant correlation between CCL24 and CCL26 levels, evaluating them intraindividually by Spearman's rank correlation test. Finally, a significant correlation was found between CCL24 and CCL26 levels and the percentage of eosinophilic infiltration of nasal mucosa.

CONCLUSION

Our data suggest that CCL26 and CCL24 are likely involved in the pathogenesis of chronic nasal hypereosinophilia, with a complex cooperation and different involvement of the various members of eotaxin family. Further studies are necessary to better understand the actual physiopathologic mechanism, possible clinical relevance, and therapeutic implications.

Novel cooperation between CX3CL1 and CCL26 inducing NK cell chemotaxis via CX3CR1: a possible mechanism for NK cell infiltration of the allergic nasal tissue

BACKGROUND

Recent data indicated that natural killer (NK) cells and chemokines could play a pivotal role in nasal inflammation. CX3CR1, the only receptor for fractalkine/CX3CL1, is abundantly expressed by NK cells, and was recently shown to also be a receptor for eotaxin-3/CCL26. However, no reports explored the NK cells-CX3CL1-CCL26 axis via CX3CR1 in allergy.

OBJECTIVE

Our goals were first to determine specifically NK cell recruitment pattern in nasal tissue of allergic chronic rhinosinusitis (ACRS) and non-allergic chronic rhinosinusitis (NACRS) patients in comparison with healthy controls, and secondly, to investigate the function of CX3CR1 in NK cell migration.

METHODS

Immunohistochemistry, microchemotaxis chambers, flow cytometry and confocal microscopy were used in this study.

RESULTS

Herein, we showed that NK cells infiltrated the epithelial layers of nasal tissue only in ACRS patients and not in NACRS patients or controls. NK cells were also more numerous in the stroma of the nasal tissue from ACRS patients compared with NACRS patients or controls. This migration could be mediated by both CX3CL1 and CCL26, as these two chemokines induced NK cell migration. Moreover, both molecules also stimulated cytoskeleton changes and F-actin reorganisation in NK cells. Chemotaxis and cytoskeleton changes were sensitive to genistein, a tyrosine kinase inhibitor. By flow cytometry, we demonstrated that a single antigen nasal provocation challenge increased the expression of CX3CR1 on NK cells in allergic rhinitis (AR) patients. The function of this receptor was associated with a significant augmentation of NK cell chemotaxis against the optimal doses of CX3CL1 and CCL26.

CONCLUSIONS AND CLINICAL RELEVANCE

Our results highlight a novel role for CX3CR1 in NK cell migration that may contribute to the NK cell trafficking to the allergic upper airway. This could be mediated largely by CX3CL1 and CCL26 stimulation of the tyrosine kinase pathway.