Nasal Epithelial Cell Line Research Articles

Ubiquitin E3 ligase TNFIAP3 mediates endosome/lysosome fusion in nasal epithelial cells

The nasal epithelial barrier dysfunction is associated with the pathogenesis of nasal allergy; the causative factors are to be further elucidated. Ubiquitin E3 ligase TNFIAP3 (TNFIAP3, in short) plays a role in the maintenance of the homeostasis in the body. This study aims to elucidate the role of TNFIAP3 in the degradation of endocytic substances in nasal epithelial cells. The nasal epithelial cell line, RPMI 2650 cells (RPC), was cultured into monolayers in transwells. The endocytosis of staphylococcal enterotoxin B (SEB) by RPC monolayers was assessed by enzyme-linked immunoassay. The endocytosis of SEB-triggered endosome/lysosome fusion was observed by immunocytochemistry. The results showed that RPC monolayers expressed TNFIAP3 upon the endocytosis of SEB. Deficiency of TNFIAP3 resulted in abundant SEBs being transported to the basal chambers of transwells via the intracellular pathway. In the TNFIAP3-sufficient RPC, SEB-carrying endosomes fused with lysosomes were observed. The TNFIAP3-deficient RPC showed few SEB-carrying endosomes fused with lysosomes. In summary, TNFIAP3 plays an important role in tethering endosomes to lysosomes in RPC.

Deficiency of ubiquitin A20 promotes antigen transport across airway epithelial cells via a transcellular pathway

The epithelial barrier dysfunction is associated with the pathogenesis of a number of diseases. Ubiquitin E3 ligase A20 (A20) plays a critical role in maintaining the homeostasis in the body. This study aimed to investigate the role of A20 in the degradation of endocytic antigens in airway epithelial cells. The expression of A20 in the human nasal epithelial cell line, RPMI 2650 cells (Rpcs), was evaluated. The role of A20 in maintaining the intracellular permeability in Rpc monolayers was assessed in Transwells. The endosome/lysosome fusion in epithelial cells was observed by immunocytochemistry. On the absorption of antigen, the expression of A20 was increased in Rpcs. The knockdown of the A20 gene in Rpcs increased the amounts of the endocytic antigens across the Rpc monolayers. A20 was required in the process of the endosome/lysosome fusion. The antigens transported to the basal compartment by A20-deficient Rpc monolayers still kept strong antigenicity. The nasal epithelial cell line, Rpcs, expresses A20 that facilitates the degradation of endocytic antigens in Rpcs by facilitating the endosome/lysosome fusion.

Ubiquitin E3 Ligase A20 Facilitates Processing Microbial Product in Nasal Epithelial Cells

Microbial products play a role in the pathogenesis of allergic diseases; ubiquitin E3 ligase A20 (A20) is an important molecule in regulating inflammation in the body. The present study aims to elucidate the role of A20 in processing the absorbed microbial products in nasal epithelial cells. Human nasal mucosal specimens were collected from patients with or without chronic rhinitis and analyzed by immunohistochemistry. Human nasal epithelial cell line, RPMI2650 cell, was employed to assess the role of A20 in processing the absorbed staphylococcal enterotoxin B (SEB). The RPMI2650 cells absorbed SEB in the culture. The increase in A20 was observed in RPMI2650 cells in parallel to the absorption of SEB. A20 is a critical molecule in the degradation of SEB in the nasal epithelial cells by promoting the tethering of endosomes and lysosomes. A20 plays a critical role in processing of the absorbed SEB in nasal epithelial cells.

Increased expression of IL‐19 in the epithelium of patients with chronic rhinosinusitis and nasal polyps

Chronic rhinosinusitis (CRS) is an inflammation of the nose and of the paranasal sinuses. The involvement of the respiratory epithelium in the mechanisms of CRS is poorly understood. Among proteins expressed by nasal epithelial cells in CRS, IL-19 may have key functions. We here aimed to determine the expression and regulation of IL-19. Nasal biopsies from normal subjects (n = 12), subjects with CRS but without nasal polyps (NP) (CRSsNP, n = 12) and with CRS with NP (CRSwNP, n = 15) were collected. Human Asthma Gene Array and real-time PCR were used to evaluate gene expression, western blot analysis and immunohistochemistry for protein expression. Results for IL-19 were confirmed by real-time PCR. The constitutive and stimulated (LPS, TGF β) expression of IL-19 and cell proliferation were evaluated in a nasal epithelial cell line (RPMI 2650). Human Asthma Gene Array showed an increased IL-19 gene expression in NP from patients with CRS in comparison with normal subjects. Real-time PCR confirmed the IL-19 mRNA up-regulation in patients with CRSwNP and showed an up-regulation of IL-19, at lower extent, in patients with chronic rhinosinusitis without nasal polyps (CRSsNP) in comparison with normal subjects. Western blot analysis confirmed that IL-19 is increased also at protein level in patients with CRSwNP in comparison with normal subjects. In NP, IL-19 is highly expressed in the metaplastic nasal epithelium when compared to normal or hyperplastic epithelium. LPS stimulation increased IL-19 expression, and recombinant IL-19 increased cell proliferation in nasal epithelial cells. IL-19 is overexpressed in the epithelium in CRSwNP and increases epithelial cell proliferation.

The effect of sucrose esters on a culture model of the nasal barrier

Sucrose esters are effective solubilizers and there is an interest to use them as pharmaceutical excipients for nasal drug delivery. We have determined for the first time the non-toxic doses of laurate and myristate sucrose esters by four independent methods, and their effects on epithelial permeability using RPMI 2650 human nasal epithelial cell line. Based on real-time cell electronic sensing, MTT dye conversion and lactate dehydrogenase release methods reference surfactant Cremophor RH40 proved to be the least toxic excipient, and could be used at 5mg/mL concentration for 1h in epithelial cells without cellular damage. The non-toxic dose of Tween 80 was 1mg/mL, while the dose of laurate and myristate sucrose esters that could be safely used on cells for 1h was 0.1mg/mL. Both the reference surfactants and the sucrose esters significantly enhanced the permeability of epithelial cell layers for the paracellular marker FITC-labelled 4.4kDa dextran at 0.1mg/mL concentration. The effects of sucrose esters on epithelial permeability were dose-dependent. These data indicate that laurate and myristate sucrose esters can be potentially used as permeability enhancers in nasal formulations to augment drug delivery to the systemic circulation.

A Model for Studying Nasal Drug Delivery: RPMI650 Human Nasal Epithelial Cell Line

Studies on nasal epithelial models are important to develop vehicles for systemic nasal drug delivery, and also for targeting drugs to brain via the nasal route. [...]

RPMI 2650 epithelial model and three-dimensional reconstructed human nasal mucosa as in vitro models for nasal permeation studies

The purpose of this study was to investigate the human nasal epithelial cell line RPMI 2650 regarding its usefulness as in vitro model for drug permeation studies. Particularly, the influence of the air–liquid interface in culture and coculture with human nasal fibroblasts (HNF) on the differentiation and permeation barrier properties of the cell layer was examined. In addition to a non-contact coculture, we developed a three-dimensional construct of the human nasal mucosa composed of a collagen matrix with embedded HNF, covered by a RPMI 2650 epithelial cell layer. Microscopic examination as well as measurement of the transepithelial electrical resistance and permeation experiments showed the importance of cultivation at the air–liquid interface. Permeation studies were performed using a paracellular marker (sodium fluorescein), a transcellular marker (propranolol-HCl) and a model substance with high molecular weight (FITC-dextran, MW 4000). The epithelial model showed an organotypic permeation barrier for paracellular, transcellular and high MW permeation. Three-dimensional reconstructed human nasal mucosa showed four- to fivefold higher permeation coefficients. Regardless of the limits of these models, both offer promise to evaluate passive drug permeation through the nasal mucosa.

Rescue of Functional F508del Cystic Fibrosis Transmembrane Conductance Regulator by Vasoactive Intestinal Peptide in the Human Nasal Epithelial Cell Line JME/CF15

F508del is the most common cystic fibrosis-causing mutation that induces early degradation and poor trafficking of cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels to the apical membrane of epithelial cells. Our previous work in bronchial serous cells showed that vasoactive intestinal peptide (VIP) stimulation of the VPAC(1) receptor enhances CFTR-dependent chloride secretion by increasing its membrane insertion by a protein kinase C (PKC)-dependent pathway. In the present study, we investigated the effect of VIP on F508del-CFTR activity and membrane insertion in the human nasal epithelial cell line JME/CF15, which also expresses the VPAC(1) receptor. At reduced temperature (27 degrees C), which rescues F508del-CFTR trafficking, acute stimulation by VIP of rescued F508del-CFTR channels was protein kinase A (PKA)- and PKC-dependent. One hour of treatment with VIP strongly increased F508del-CFTR activity, with iodide efflux peaks three times higher than with untreated cells. At 37 degrees C, VIP-treated cells, but not untreated controls, showed significant iodide efflux peaks that were sensitive to the CFTR inhibitor 3-[(3-trifluoromethyl)phenyl]-5-[(4-carboxyphenyl)methylene]-2-thioxo-4-thiazolidinone (CFTR(inh)-172). Immunostaining, biotinylation assays, and Western blots confirmed a VIP-induced maturation and membrane insertion of F508del-CFTR at 37 degrees C. The corrector effect of VIP was abolished by the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamidedihydrochloride (H89), whereas Galpha(s) stimulation by cholera toxin significantly increased F508del-CFTR trafficking. On the other hand, membrane localization, but not maturation, of F508del-CFTR was significantly reduced by the PKC inhibitor bisindolylmaleimide X and the G(i/o) protein inhibitor pertussis toxin. VIP treatment had no effect on intracellular calcium or proteasome activity. These results indicate that, in human nasal cells, VIP rescues trafficking and membrane insertion of functional F508del-CFTR channels at physiological temperature by stimulating both PKA- and PKC-dependent pathways.

A Cystic Fibrosis Respiratory Epithelial Cell Chronically Treated by Miglustat Acquires a Non–Cystic Fibrosis–Like Phenotype

Cystic fibrosis (CF) is a fatal, autosomal and recessive genetic disease that is mainly due to inactivating mutations in the chloride channel CF transmembrane conductance regulator (CFTR). Sodium hyperabsorption by the airways, profound lung inflammation, and dysregulation of calcium homeostasis, are presumably causally related to loss of CFTR-dependent chloride function in patients with CF. Miglustat (N-butyldeoxynojirimycin, Zavesca), an inhibitor of the alpha-1,2 glucosidase, has been proposed for clinical use in CF because of its effect as a corrector of the defective trafficking of F508del-CFTR. In the present study, we show that daily treatment for 2 months with low concentrations of miglustat on the human CF nasal epithelial cell line, JME/CF15 (F508del/F508del-CFTR), results in progressive, stable, reversible, and sustained correction of F508del-CFTR trafficking, down-regulation of sodium hyperabsorption, and regulation of the calcium homeostasis. In conclusion, we provide here the first evidence that a respiratory CF cell can acquire a non-CF-like phenotype when chronically treated with low concentrations of a pharmacological drug.

Guanabenz, an α 2-selective adrenergic agonist, activates Ca 2+-dependent chloride currents in cystic fibrosis human airway epithelial cells

In cystic fibrosis respiratory epithelial cells, the absence or dysfunction of the chloride channel CFTR (Cystic Fibrosis Transmembrane conductance Regulator) results in reduced chloride ion transport. In contrast, Ca 2+-stimulated Cl − secretion is intact in cystic fibrosis airway epithelia. One possible target for drug discovery aiming at treating cystic fibrosis is to correct the ionic imbalance through stimulation of alternative ionic pathways that may compensate the failure of epithelial Cl − conductance. Here, using a simple high-throughput screening assay to search for Cl − channels modulators in the cystic fibrosis nasal epithelial cell line JME-CF15, the compound guanabenz (Wytensin ®), an α 2-selective adrenergic agonist was found positive. Using iodide effluxes and electrophysiological recordings, we showed that guanabenz-activated (EC 50 = 831 nM) a DIDS (4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid) sensitive and Ca 2+ dependent Cl − channel (CaCC). Guanabenz activated a linear Cl − channel with unitary single-channel conductance of 8 pS. Recording calcium signals in CF15 cells showed that guanabenz increased the intracellular Ca 2+ concentration stimulating an influx of Ca 2+. In the absence of extracellular Ca 2+, the guanabenz effects on Ca 2+ influx and activation of CaCC were both abolished. These data demonstrate that guanabenz activates Ca 2+-dependent Cl − channels via a Ca 2+ influx in human cystic fibrosis airway epithelial cells.

Characterization of 3 Oral Squamous Cell Carcinoma Cell Lines With Different Invasion and/or Metastatic Potentials

Proteolytic enzymes may confer specific types of invasion and metastasis in patients with oral squamous cell carcinoma (OSCC). The purpose of this study was to determine if OSCC that invades adjacent bone has different proteolytic enzyme expression profiles than OSCC that metastasizes to lymph nodes or distant organs. Three OSCC cell lines, BHY, HSC-3, and HN, with known behavior regarding bone invasion and lymph node and distant metastatic profiles, were evaluated. The characteristics of a control, human normal nasal epithelial cell line (HNEC), and BHY, HSC-3 and HN were evaluated with regard to their expression of the matrix metalloproteinases and cathepsins. Expressions of proteolytic enzymes including matrix metalloproteinase, MMP-1, MMP-2, MMP-3, MMP-9, extracellular matrix metalloproteinase inducer (EMMPRIN), cathepsin B, and cathepsin L were compared using immunocytochemistry and flow cytometry in 3 OSCC cell lines and HNEC. The cell morphologies of these 4 cell lines were compared using transmission electron microscopy (TEM). All OSCC cell lines showed higher expression of all the proteolytic proteins when compared with HNEC, except the HSC-3 cell line showed no difference in the expression of MMP-9. There was no detectable difference at the expression level of MMP-1, MMP-2, MMP-3, cathepsin B, and cathepsin L in any of the OSCC cell lines. However, MMP-9 and EMMPRIN levels were higher in the BHY cell line. According to electron microscopy, the cells of the HSC-3 cell line were the smallest and least differentiated among the 3 OSCC cell lines. The BHY cell line was the most highly differentiated showing interdigitation and numerous cell junctions. MMPs play an important role in the invasion and metastasis of oral cancer. MMP-9 might play a more important role than MMP-2 during invasion. Increased expression of MMP-1, MMP-9, and EMMPRIN proteins might be involved in invasion of OSCC to adjacent bone, as they are necessary for the collagen matrix degradation. Increased expression of MMP-3, cathepsin B and L in OSCC might be associated with both invasion and a high incidence of metastasis.

The novel use of the human nasal epithelial cell line RPMI 2650 as an in vitro model to study the influence of allergens and cytokines on transforming growth factor‐β gene expression and protein release

The epithelial accumulation of mast cells is a feature of allergic rhinitis and this has been linked to the expression of the known mast cell chemoattractant transforming growth factor-beta (TGF-beta) at this site. Little is known concerning the regulation of TGF-beta gene expression or protein release by nasal epithelial cells. To address this we have utilized the RPMI 2650 human nasal epithelial cell line, which has some features that closely resemble normal nasal epithelium and has been reported to secrete a TGF-beta-like molecule. To investigate the regulation of TGF-beta gene expression and protein secretion in RPMI 2650 nasal epithelial cells following exposure to allergens (house dust mite (HDM) and grass pollen) and mast cell associated T-helper type 2 (Th2) cytokines (IL-4, IL-13, and TNF-alpha). Methods Light and scanning electron microscopy was used to evaluate the morphology of RPMI 2650 cells in culture, enzyme-linked immunosorbent assay was used to investigate their TGF-beta secretory capacity and the identification of the TGF-beta isotype(s) involved, flow cytometry was used to demonstrate the presence of TGF-beta receptors on the RPMI 2650 cells, and the quantitative real-time TaqMan PCR was used to measure TGF-beta gene expression. TGF-beta(2) was identified as the main isotype secreted by the RPMI 2650 cells. HDM allergens and TNF-alpha increased both TGF-beta gene expression and protein release from these cells, whereas grass pollen, IL-4, and IL-13 were without effect. The RPMI 2650 nasal epithelial cell line represents a valid in vitro model to evaluate the regulation of TGF-beta biology. In this system HDM allergens have stimulatory activity that is fundamentally different from that of grass pollen allergens, and the Th2 cytokines IL-4 and IL-13 are without effect. The ability of TNF-alpha to up-regulate both TGF-beta gene expression and protein release indicates that mast cell-epithelial interactions concerning TGF-beta are bi-directional and this may be fundamental to epithelial immunoregulation. The availability of a model system, such as the RPMI 2650 cells, will enable the early evaluation of future novel and targeted interventions directed toward the aberrant responses of upper airway structural cells.

Cystic Fibrosis Transmembrane Conductance Regulator Does Not Affect Neutrophil Migration across Cystic Fibrosis Airway Epithelial Monolayers

Recent studies have shown that airway inflammation dominated by neutrophils, ie, polymorphonuclear cells (PMN) was observed in infants and children with cystic fibrosis (CF) even in the absence of detectable infection. To assess whether there is a CF-related anomaly of PMN migration across airway epithelial cells, we developed an in vitro model of chemotactic migration across tight and polarized CF(15) cells, a CF human nasal epithelial cell line, seeded on porous filters. To compare PMN migration across a pair of CF and control monolayers in the physiological direction, inverted CF(15) cells were infected with increasing concentrations of recombinant adenoviruses containing either the normal cystic fibrosis transmembrane conductance regulator (CFTR) cDNA, the DeltaF508 CFTR cDNA, or the beta-galactosidase gene. The number of PMN migrating in response to N-formyl-Met-Leu-Phe across inverted CF(15) monolayers expressing beta-galactosidase was similar to that seen across CF(15) monolayers rescued with CFTR, whatever the proportion of cells expressing the transgene. Moreover, PMN migration across monolayers expressing various amounts of mutated CFTR was not different from that observed across matched counterparts expressing normal CFTR. Finally, PMN migration in response to adherent or Pseudomonas aeruginosa was equivalent across CF and corrected monolayers. The possibility that mutated CFTR may exert indirect effects on PMN recruitment, via an abnormal production of the chemotactic cytokine interleukin-8, was also explored. Apical and basolateral production of interleukin-8 by polarized CF cells expressing mutated CFTR was not different from that observed with rescued cells, either in baseline or stimulated conditions. CF(15) cells displayed a CF phenotype that could be corrected by CFTR-containing adenoviruses, because two known CF defects, Cl(-) secretion and increased P. aeruginosa adherence, were normalized after infection with those viruses. Thus, we conclude that the presence of a mutated CFTR does not per se lead to an exaggerated inflammatory response of CF surface epithelial cells in the absence or presence of a bacterial infection.

Hepatocyte Growth Factor Inhibits Amiloride-Sensitive Na+Channel Function in Cystic Fibrosis Airway Epithelium in vitro

Cystic fibrosis (CF) airway epithelial cells have a reduced cAMP-dependent Cl−conductance channel (CFTR) function but an increased level of amiloride-sensitive Na+channel (ENaC) activity. Recently, expression of theα-subunit of the ENaC protein complex was shown to be down-regulated by activation of the extracellular signal-regulated protein kinase (ERK) pathway. In the present study we have examined the actions of a potent regulator of the ERK pathway, recombinant human hepatocyte growth factor (rhHGF), on the function of ENaC in confluent, polarized monolayers of both primary cultures of CF airway cells and an SV40-transformed CF nasal epithelial cell line (JME CF/15). Treatment of JME/CF 15 cells with rhHGF at concentrations of 100 ng/ml and above was found to dramatically decrease the activity of amiloride-sensitive Na+transport. This effect required basolateral exposure of the cytokine. Addition of 100 ng/ml rhHGF to JME/CF 15 cells decreased Ieqwith a t1/2of 18 h, with a maximal inhibition of 90% by 36 h. By 48 h, stimulation with rhHGF induced a down-regulation of its receptor,c-met, expressed in these cells. The decrease in Ieqof JME/CF 15 monolayers was not immediately reversed upon removal of rhHGF. Treatment with rhHGF did not appear to affect monolayer resistances nor Cl−currents induced by mediators such as isoproterenol, histamine or bradykinin. Studies with primary cultures of CF airway cell sheets demonstrated comparable sensitivity and time-course properties for the inhibition of amiloride-sensitive currents following rhHGF addition. These observations are consistent with the possible application of an extracellular signalling molecule, such as the cytokine HGF, to reduce the abnormally high activity of amiloride-sensitive Na+ion channels observed in CF airway cells.

Roles of Soluble Fibronectin and β 1 Integrin Receptors in the Binding of Mycobacterium leprae to NaSal Epithelial Cells

The mechanisms by which Mycobacterium leprae invades the human host are presently unknown. We investigated the ability of M. leprae to bind to human RPMI 2650 cells, a human nasal septal epithelial cell line, using both microscopic observation and an ELISA technique. The results demonstrated that M. leprae adheres to nasal cells after binding to soluble fibronectin. Furthermore, it was observed that M. leprae could bind to the β 1 chain of the integrins in the absence of serum or mucus. These results demonstrated that M. leprae uses fibronectin and fibronectin receptors on the surface of epithelial cells to bind and possibly invade the nasal epithelial cells.

MUC1 mucin mRNA expression in cultured human nasal and bronchial epithelial cells.

The MUC1 mucin mRNA, for which the cDNA was previously cloned from human breast and pancreatic tissues, was found to be expressed in nasal and bronchial epithelial cell primary cultures from cystic fibrotic, atopic, and normal individuals. Sequence analysis of cDNA clones from the CF/T43 cystic fibrosis nasal epithelial cell line revealed only insignificant differences in the 3' untranslated region of the mRNA when compared with the pancreas and breast mucin cDNAs.

Aminopeptidases of newborn bovine nasal turbinate epithelial cell cultures

Newborn bovine nasal turbinate epithelial cell cultures were grown to confluent monolayers and characterized by electron and light microscopy. The passaged nasal turbinate cells retain some similar but not identical morphological characteristics (e.g., microvilli, cuboidal shape, dome formation, apparent mucin granules) exhibited by parent tissue. Morphological properties, however, were consistent with other nasal cell culture systems that have been used to elucidate transport and metabolic features of nasal mucosa. The activity of aminopeptidases in homogenates of the turbinate cell cultures was assayed with 4-methoxy-2-naphthylamides of leucine, alanine, and arginine as substrates. The observed pattern of hydrolysis, apparent kinetic parameters, and inhibition by typical aminopeptidase inhibitors, puromycin and bestatin, were consistent with reported characteristics of aminopeptidases associated with excised nasal epithelial cells. Results here form the basis for consideration of the continuous newborn bovine nasal turbinate epithelial cell line in examining the role of aminopeptidases in determining the metabolic fate of intranasally administered peptides and proteins.