Shin-ichirou Narita

Expression and localization of the cysteinyl leukotriene 1 receptor in human nasal mucosa

Background The cysteinyl leukotrienes (CysLT) are lipid mediators that have been implicated in the pathogenesis of allergic diseases. Pharmacological studies using CysLTs indicate that two classes of receptors, named CysLT1 and CysLT2 receptor, exist. The former is sensitive to the CysLT1 antagonist currently used to treat asthma and allergic rhinitis. Recently, the cDNA for human CysLT1 and CysLT2 receptor have been cloned, making it now possible to study the gene expression of CysLTs receptors.

Effects of a cysteinyl leukotriene antagonist, ONO-1078 (pranlukast), on total airway resistance after antigen challenge in sensitized guinea pigs.

Abstract.Objective and Design: To define the role of leukotriene (LT) in allergic rhinitis, we examined the effects of a cysteinyl (Cys) LT antagonist (ONO-1078, pranlukast).¶Material: Actively sensitized Dunkin-Hartley guinea pigs.¶Treatment: ONO-1078 (pranlukast), 3–100 mg/kg p.o. l h before antigen challenge.¶Methods: Nasal symptoms (sneezing, nasal scratches), changes of total airway resistance (TAR by plethysmography) and eosinophil infiltration into the nasal mucosa were determined following topical antigen (OA) challenge. Dunnets test (TAR and symptoms) and the Mann-Whitney U-test (eosinophils) were applied.¶Results: Control animals showed bi-phasic nasal responses, peaking 10 min and 240 min after the topical antigen challenge, respectively. While the early-phase response was characterized by nasal symptoms of sneezing and scratching accompanied by the increase in TAR, the late-phase was characterized by an increase in TAR accompanied by eosinophil infiltration into nasal mucosa. The nasal symptoms (sneezing and scratching) were not inhibited by pretreatment with ONO-1078 at doses up to 100 mg/kg (p.o., n = 15). Although early peak responses of TAR were not affected with even the highest dose (30 mg/kg, p.o., n = 6), late-phase TAR peak response (control: 174.8 ± 8.2%, n = 6) were significantly inhibited by 10 mg/kg (142.7 ± 15.8%; p < 0.05, n = 6) and 30 mg/kg (118.0 ± 6.6%; p < 0.01, n = 6) of ONO-1078 (p.o.). In addition, the eosinophil infiltration induced by the antigen was not inhibited by ONO-1078 (30 and 100 mg/kg, p.o., n = 6).¶Conclusions: Our results suggest that Cys LT may play an important role in the late-phase increase in TAR in the guinea pig model of allergic rhinitis.

Effect of glucocorticosteroids on tumour necrosis factor‐α‐induced intercellular adhesion molecule‐1 expression in cultured primary human nasal epithelial cells

Objective In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule‐1 (ICAM‐1) expression, we examined ICAM‐1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels.

Tumor necrosis factor increases MUC1 mRNA in cultured human nasal epithelial cells.

Objective--Mucins are high molecular weight glycoproteins which are normally expressed on the surface of a variety of epithelia. It is possible that shedding of such molecules from the epithelium could play a role in preventing bacterial colonization at the mucosal surface. Immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of human inferior turbinates have shown the existence of MUC1 mucin in nasal mucosa. However, the regulatory mechanisms of MUC1 mucin are poorly understood. In order to clarify the modulation of mucin gene expression, we developed a real-time semi-quantitative RT-PCR based on TaqMan fluorescence methodology to quantify MUC1 mRNA in primary cultured human nasal epithelial cells (HNECs).Material and Methods--HNECs were stimulated with recombinant human tumor necrosis factor (TNF)-α (20 pg/ml to 20 ng/ml) for specified time periods (0, 12, 24 and 48 h) and MUC1 mRNA was determined by means of semi-quantitative RT-PCR.Results--Significant increases in MUC1 gene expression in HNECs were initially detected at 12 h, peaking at 24 h after stimulation. TNF-mediated MUC1 mRNA expression at 24 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor.Conclusions--TNF-mediated MUC1 gene expression may contribute to the pathogenesis of human inflammatory upper airway disorders. Also, our mucin mRNA real-time PCR provides a quantitative method for investigating the regulation of mucin gene expression in both healthy and diseased samples.

Expression and Localization of Steroid Receptors in Human Nasal Mucosa

Objective—To investigate the expression of glucocorticoid receptor (GR), oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) in nasal mucosa. Material and Methods—Human turbinates were obtained after turbinectomy from seven patients. The expression and localization of steroid receptors were examined using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Results—Using RT-PCR, GR and ERα mRNA were detected in all cases. In contrast, ERβ, PR and AR mRNA were found in five, four and six cases, respectively. Using immunohistochemistry, antibodies to GR showed the presence of GR within all cells of nasal mucosa, with the highest quantities of GR being localized in epithelial cells, submucosal glands and inflammatory leukocytes. Immunohistochemical analysis of sex steroid receptor revealed that anti-ERα antibody labelled mainly mast cells and anti-ERβ antibody labelled submucosal glands, and that no PR or AR expression was detected in any of the samples tested. Conclusions—The role of ER in mast cells and submucosal glands has not been well clarified. However, precise knowledge of the identity and distribution of sex steroid receptor should be of considerable interest in understanding the role of sex hormones in upper airway diseases such as allergic and non-allergic rhinitis.

The effects of NK1 receptor antagonists (FK224 and FK888) on agonist- and antigen-induced nasal microvascular leakage in guinea pigs

Abstract.  Objective: To study the inhibitory effects of two NK1 receptor antagonists on substance P (SP) and antigen-induced increase of nasal vascular permeability in ovalbumen (OA)-sensitized guinea pigs. ¶Material: Male Dunkin-Hartley guinea pigs. ¶Treatment: SP (100 ;mol/l), FK224 (1–10  mol/kg) and FK888 (0.2– 2 mol/kg). ¶Methods: The in vivo model of nasal microvascular leakage was used for nasal allergic challenge in ovalbumin (OA)-sensitized guinea pigs, or nasal stimulation with substance P (SP) in non-sensitized animals. Nasal microvascular leakage was measured by the accumulation of Evans Blue dye after intravenous injection. ¶Results: Following nasal stimulation with SP 100 M, the concentration of dye in the nasal lavage fluid rapidly increased. NK1 receptor antagonists FK224 (10 mol/kg i.v.) and FK888 (2 mol/kg i.v.) inhibited SP-induced microvascular leakage. In OA-sensitized guinea pigs, exudation of dye into nasal lavage fluid was observed soon after topical antigenic stimulation and continued for over 60 min. Both NK1 receptor antagonists inhibited the immediate phase of the antigen-induced microvascular leakage. ¶Conclusions: We conclude that the immediate change of vascular permeability during the nasal allergic response is mediated by activation of the NK1 receptor in the guinea-pig.

Effects of cetirizine on substance P release in patients with perennial allergic rhinitis.

To evaluate the effect of cetirizine hydrochloride on substance P release in allergic rhinitis, we performed a single-blind placebo-controlled study of 14 patients with perennial allergic rhinitis (7 treated with cetirizine and 7 with placebo). After an initial nasal allergen challenge with lavages, the subjects received treatment with placebo or cetirizine hydrochloride (10 mg by mouth daily) for 1 week, followed by the second nasal allergen challenge with lavages. The levels of albumin, histamine, and substance P in nasal lavages before and after allergen challenge were quantified by enzyme-linked immunosorbent assay. Pretreatment of subjects with cetirizine reduced the level of substance P induced by antigen challenge, but did not significantly reduce levels of histamine. These results suggest that cetirizine may reduce nasal neurogenic inflammation by modulating the release of substance P in allergic rhinitis.