DNA Stability, Regeneration Capacity, and Mucociliary Differentiation of Human Nasal Mucosa Cells in Tissue Systems

For culture models of primary cells of the human nasal mucosa, monocultures with epithelial cells (ECs) are used as well as cocultures with ECs and fibroblasts (FBs). Well-differentiated models of the respiratory nasal epithelium can be used for ecogenotoxicological assessments, for experiments on host/pathogen interactions, or tissue engineering. However, long-term cultivation and repeated passaging may induce a loss of DNA integrity or cell functionality. The aim of this study was to evaluate these parameters in test systems created from primary nasal mucosa cells. Enzymatic and sequential cell isolation from nasal tissue was performed. EC monocultures and compartment-separated EC-FB cocultures were cultivated over three passages under air/liquid interface conditions. DNA stability and regenerative capacity at the DNA and chromosomal level as well as proliferation and cell differentiation were examined. Both methods showed equivalent levels of DNA stability and regenerative capacity over all passages. Sequential growth of the coculture provided higher cell purity, while enzymatic cell harvest was associated with FB contamination in EC culture. Mucociliary differentiation was verified with electron microscopy in both methods. Functionality measured by lipopolysaccharide stimulation of interleukins was constant over long-term cultivation. Our data confirm DNA stability in long-term cell cultivation as well as functional integrity in both culture methods. Sequential cell isolation should be favored over enzymatic isolation due to higher culture purity. Impact statement Cell culture models are frequently used for ecogenotoxicological assessments, for experiments on host/pathogen interactions, or tissue engineering. However, DNA stability and functional integrity after long-term cultivation in such tissue models have not been investigated, yet. This study is the first showing systematic and evident data on DNA damage and functional aspects in primary human cell culture models of nasal epithelium.

Neutrophils as a Protagonist and Target in Chronic Rhinosinusitis

Neutrophils have traditionally been acknowledged as the first immune cells that are recruited to inflamed tissues during acute inflammation. By contrast, their importance in the context of chronic inflammation has been studied in less depth. Neutrophils can be recruited and are largely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS) both in Asians and in Caucasians. Increased infiltration of neutrophils in patients with CRS has been linked to poor corticosteroid response and disease prognosis. Meanwhile, tissue neutrophils may possess specific phenotypic features distinguishing them from resting blood counterparts and are endowed with particular functions, such as cytokines and chemokines production, thus may contribute to the pathogenesis of CRS. This review aims to summarize our current understanding of the pathophysiologic mechanisms of CRS, with a focus on the roles of neutrophils. We discuss recruitment, function, and regulation of neutrophils in CRS and outline the potential therapeutic strategies targeting neutrophils.

Superior effect of MP-AzeFlu than azelastine or fluticasone propionate alone on reducing inflammatory markers

BACKGROUND

MP-AzeFlu, intranasal formulation of azelastine hydrochloride (AZE) and fluticasone propionate (FP), is superior to AZE or FP alone for treatment of allergic rhinitis (AR). However, the precise anti-inflammatory mechanism of action of MP-AzeFlu has not been characterized.

OBJECTIVE

To investigate the anti-inflammatory effects of MP-AzeFlu compared with AZE or FP alone in an established in vitro model of eosinophilic inflammation.

METHODS

Nasal mucosal epithelial cells and peripheral blood eosinophils were obtained from human volunteers. Epithelial cells were stimulated with 10% fetal bovine serum (FBS) in the presence of MP-AzeFlu, AZE, or FP (1:102 to 1:105 dilution). Concentrations of interleukin (IL)-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were measured by ELISA. Eosinophils were incubated in 10% human epithelial cell-conditioned medium (HECM) and survival assessed by trypan blue dye exclusion. Results are expressed as mean ± SEM percentage secretion/survival compared with FBS/HECM (respectively).

RESULTS

FP and MP-AzeFlu (all dilutions) and AZE (1:102) significantly reduced IL-6 secretion and eosinophil survival compared with positive controls. At 1:102 dilution, IL-6 secretion was significantly lower with MP-AzeFlu (38.3 ± 4.2%, compared with FBS = 100%) than with AZE (76.1 ± 4.9%) or FP (53.0 ± 4.9%). At 1:102 dilution, eosinophil survival was significantly lower with MP-AzeFlu at day 3 (17.5 ± 3.0%) and day 4 (2.4 ± 1.4%, compared with HECM = 100%) than with AZE (day 3: 75.2 ± 7.2%; day 4: 44.0 ± 9.7%) or FP (day 3: 38.5 ± 3.5%; day 4: 14.6 ± 4.0%).

CONCLUSION

Greater reductions in cytokine secretion and eosinophil survival observed with MP-AzeFlu in vitro may underlie MP-AzeFlu's superior clinical efficacy vs. AZE or FP alone observed in AR patients.

Effects of Fluticasone Furoate Nasal Spray on Parameters of Eosinophilic Inflammation in Patients With Nasal Polyposis and Perennial Allergic Rhinitis

OBJECTIVES

Regulated on activation normal T cell expressed and secreted (RANTES) and eotaxin-2 have been postulated to be responsible for eosinophilia in chronically inflamed nasal mucosa. This study evaluated mucosal production of RANTES and eotaxin-2 in patients with perennial allergic rhinitis (PAR) and nonallergic and allergic form of chronic rhinosinusitis with nasal polyps (CRSwNP) before and after nasal corticosteroid treatment.

METHODS

Twenty patients with PAR, 20 nonallergic and 20 allergic CRSwNP patients, and 20 healthy controls were included. The RANTES and eotaxin-2 levels were measured in nasal secretion samples. The patients with chronic inflammation were treated with fluticasone furoate nasal spray for 2 weeks. Cytological examination and measurement of RANTES and eotaxin-2 in nasal fluid were performed before and after the treatment.

RESULTS

The levels of RANTES were higher in patients with PAR ( P < .05) and nonallergic ( P < .01) and allergic CRSwNP patients ( P < .001) compared to controls. Eotaxin-2 levels were higher in all 3 inflammation groups compared to healthy subjects ( P < .001). After the treatment, we found a significant decrease of RANTES and eotaxin-2 concentrations ( P < .001) in all 3 groups of patients.

CONCLUSION

The levels of RANTES and eotaxin-2 in nasal fluid could be reliable markers for assessing corticosteroid administration outcomes.

Increased expression of α7nAChR in chronic rhinosinusitis: The intranasal cholinergic anti-inflammatory hypothesis

OBJECTIVE

Chronic rhinosinusitis results from a dysfunctional host-environment interaction at the site of interface, in the nose and paranasal sinuses. A parasympathetic-mediated anti-inflammatory reflex is known to have a pivotal role in the control of damage induced by immune response to injury and infection; acetylcholine released by peripheral nerves interacts with nicotinic acetylcholine receptor subunit α7 - α7nAChR - of innate immune cells, inhibiting pro-inflammatory signalling. This work aims to investigate whether cholinergic function is implicated in chronic rhinosinusitis.

METHODS

α7nAChR mRNA and protein levels were measured in nasal biopsy specimens of 14 patients with CRSwNP, 8 with CRSsNP and 10 control subjects, undergoing surgery.

RESULTS

Gene expression levels of α7nAChR did not differ between groups; protein expression was significantly higher in CRSwNP than in CRSsNP (p=0.041), and both of these patient groups showed significant higher levels than controls (CRSwNP vs Controls - p=0.001; CRSsNP vs Controls - p=0.041).

CONCLUSION

Elevated α7nAChR protein levels suggest that the cholinergic system is involved in the inflammatory response of chronic rhinosinusitis. This can shed light on both, the disease pathophysiology and the development of future treatment options.