Gene and protein expression of protease-activated receptor 2 in structural and inflammatory cells in the nasal mucosa in seasonal allergic rhinitis

BACKGROUND

Protease-activated receptor 2 (PAR 2) has been shown to be responsible for trypsin and mast cell tryptase-induced airway inflammation. Here, the present study aimed to explore the expression of PAR 2 in the nasal mucosa of seasonal allergic rhinitis (SAR).

METHODS

Study subjects were recruited for the study by medical history, physical examination and laboratory screening tests. Using immunohistochemistry, laser-assisted cell picking and subsequently real-time PCR, nasal mucosa biopsies of SAR patients were investigated for PAR 2 gene and protein expression in complex tissues of the nasal mucosa.

RESULTS

Gene and protein expression of PAR 2 was firstly detected in nasal mucosa of SAR patients. The relative gene expression level of PAR 2 was significantly increased in complex tissues of the nasal mucosa of SAR (6.21+/-4.02 vs. controls: 1.38+/-0.86, P=0.004). Moreover, PAR 2 mRNA expression in epithelial cells (SAR: 4.78+/-4.64 vs. controls: 0.84+/-0.61, P=0.003) but not in mucus (SAR: 1.51+/-1.15 vs. controls: 1.35+/-1.02, P=0.78) and endothelial cells (SAR: 1.20+/-0.57 vs. controls: 1.73+/-1.30, P=0.5) was found to be significantly changed in the nasal mucosa in SAR. Using double immunohistochemistry the present study demonstrated that the total numbers of mast cells (P=0.0003) and eosinophils (P=0.03) and the numbers of eosinophils expressing PAR 2 (P=0.006) were significantly elevated in the nasal mucosa of SAR compared with the controls.

CONCLUSION

The abundant presence and distribution of gene and protein expression of PAR 2 in different cell types in the nasal mucosa under normal situation, the increased expression of PAR 2 in epithelial cells and the increased number of eosinophils with PAR 2 suggest that PAR 2 may contribute to the pathogenesis of allergic diseases such as SAR.

Transcriptional up-regulation of histamine receptor-1 in epithelial, mucus and inflammatory cells in perennial allergic rhinitis

BACKGROUND

Histamine receptors play an important role in the pathogenesis of nasal allergy. Activation of histamine receptor 1 (H1R) and 2 (H2R) can cause allergic symptoms which can be blocked effectively by antihistamines. H1R and H2R transcript levels have been found to be up-regulated in perennial - but not in seasonal - allergic rhinitis (AR). The present study aimed to explore H1R and H2R expression in complex tissues of the nasal mucosa of perennial allergic rhinitis (PAR).

METHODS

Ten patients with PAR and 13 non-AR subjects were recruited for the study by medical history, physical examination and laboratory screening tests. In this study, we have analysed single cells dissected from the nasal mucosa biopsies by laser-assisted microdissection. H1R mRNA expression was analysed in different cell types such as epithelial, endothelial, mucus and inflammatory cells isolated from the nasal mucosa of PAR in comparison with non-AR subjects.

RESULTS

H1R mRNA gene expression level was significantly increased in the nasal mucosa of PAR in comparison with non-AR (P<0.0001). H1R mRNA was significantly elevated in epithelial (P<0.001) and mucus cells (P<0.05) of PAR in comparison with non-AR whereas H1R gene expression levels in endothelial cells between both groups were not changed (P=0.23). Interestingly, inflammatory cells in the nasal mucosa of PAR patients were also strongly expressed H1R mRNA (P<0.001).

CONCLUSION

The present study indicates that PAR alters the expression of H1R mRNA in epithelial, mucus and inflammatory cells of the nasal mucosa and but not in endothelial cells. Therefore, epithelial, mucus and inflammatory cells may play an important role in histamine-mediated allergic airway inflammation in PAR.

A novel per-oral insulin formulation: proof of concept study in non-diabetic subjects

AIMS

The aim of our study was to examine the absorption of insulin from the gastrointestinal (GI) tract, using a novel oral formulation-adding a delivery agent SNAC (sodium N-[8-(2-hydroxybenzoyl)amino] caprylate) in combination with insulin.

METHODS

Capsules containing insulin and SNAC, in various combinations, were administered orally, as a single dose, to 12 non-diabetic subjects and four control subjects (receiving SNAC or insulin only) in order to assess its biological effect and safety. Plasma glucose levels, insulin and C-peptide concentrations, as well as SNAC levels, were determined, at timed intervals up to 4 h.

RESULTS

In all cases, a glucose-lowering effect was demonstrated, preceded by an increase in plasma insulin levels. The nadir of plasma glucose levels appeared after 30-50 min, following the ingestion of the mixture. The plasma insulin levels were found to parallel the blood SNAC levels. Plasma C-peptide levels were suppressed by the lowered glucose levels achieved concurrent with the increasing amount of exogenous insulin absorbed, indicating that the secretion of endogenous hormone was partially abolished. There were no biological effects regarding blood glucose levels upon administration of SNAC or insulin when given alone. No adverse effects were detected during the trial or several weeks after the trial.

CONCLUSIONS

Insulin in combination with a novel delivery agent, SNAC, given orally, is absorbed through the GI tract in a biologically active form. This was demonstrated by a glucose lowering effect of the mixture as well as a suppression of an endogenous insulin secretion.

HPV-assoziierte Tonsillenkarzinome

The major risk factors for head and neck squamous cell carcinomas (HNSCC) are considered to be tobacco and alcohol. A link between oncogenic types of the human papilloma virus (HPV) and the risk of HNSCC has been suggested in the literature. However, the causal link is now becoming more firmly established on the basis of recent analyses. About 20% of all HNSCC and more than 50% of tonsillar cancers contain HR-HPV. The causal role of HPV-infection in carcinogenesis and the molecular mechanisms involved could thus far be best elucidated in the case of cervical carcinomas. New insights and increasing evidence for the analogy of HPV-positive HNSCC with cervical cancer are discussed. The definition of HPV-positive HNSCC has become more important due to the implications for risk factors and prognosis.

An in vivo investigation of the rabbit skin responses to transdermal iontophoresis

To optimize the benefits of transdermal iontophoresis, it is necessary to develop a suitable animal model that would allow for extensive assessments of the biological effects associated with electro-transport. Rabbit skin responses to iontophoresis treatments were evaluated by visual scoring and by non-invasive bioengineering parameters and compared with available human data. In the current density range 0.1-1.0 mA/cm(2) applied for 1 h using 0.9% w/v NaCl and 0.5 mA/cm(2) for up to 4 h, no significant irritation was observed. 2 mA/cm(2) applied through an area of 1 cm(2) for 1 h resulted in slight erythema at both active electrode sites but without significant changes in transepidermal water loss (TEWL) and laser Doppler velocimetry (LDV). A value of 4 mA/cm(2) under similar conditions caused moderate erythema at the anode and cathode with TEWL and LDV being significantly elevated at both sites; 1 mA/cm(2) current applied for 4 h, caused moderate erythema at both anode and cathode; and 1 mA/cm(2) applied for 1 h caused no irritation when the area of exposure was increased from 1 to 4.5 cm(2). When significant irritation and barrier impairment occurred, the erythema was resolved within 24 h with barrier recovery complete 3-5 days post-treatment. Rabbit skin thus shows promise as an acceptable model for iontophoresis experiments.

Transdermal iontophoretic delivery of methylphenidate HCl in vitro

Methylphenidate is prescribed orally for Attention Deficit Disorder in children and adults, and for narcolepsy patients. Methylphenidate has a short plasma half-life (1-2 h) and thus needs to be frequently administered for effective therapy. Such therapy has limitations in terms of patient compliance, particularly in young children. For such reasons, the development of a transdermal dosage form of methylphenidate may be useful. This study was undertaken to evaluate the passive and electrically assisted transport (iontophoresis) of methylphenidate from aqueous methylphenidate hydrochloride solutions across excised human skin. A maximum flux of 12.0 micrograms/(cm2 h) of protonated methylphenidate was estimated from the passive transport data at pH 3.5. Iontophoresis significantly enhanced protonated methylphenidate transport as compared with passive delivery. From the present experiments, the efficiency of iontophoretic delivery of methylphenidate was approximately 700 micrograms/(mA h). Based on in vitro skin flux data, the daily dose of 15-40 mg methylphenidate can be achieved using a current density of 0.5 mA/cm2 and a minimum transport area of 2-5 cm2 for 24-h application, or an area of 4-10 cm2 for 12-h (daytime) application. From methylphenidate skin flux values, methylphenidate mobility of 2.2 x 10(-4) cm2/(V s) was estimated, which compares reasonably with its free solution mobility of 6.6 x 10(-4) cm2/(V s).

Dual effects of a phorbol ester on calcium-dependent chloride secretion by T84 epithelial cells

Ca(2+)-dependent secretagogues (e.g., carbachol, histamine, ionomycin, and 4-bromo-A23187) have relatively transient effects on chloride secretion, even if there is a sustained increase in cytosolic calcium ([Ca2+]i) (as for the ionophores). Because these agents increase both [Ca2+]i and protein kinase C (PKC) activity, chloride secretion might be stimulated by [Ca2+]i and terminated by PKC activity. We tested the effect of a PKC activator, phorbol 12-myristate 13-acetate (PMA), on Cl- secretion by T84 cell monolayers by measuring short-circuit current (Isc). PMA alone had no effect on Isc but potentiated increases in Isc when added 10 min or less before Ca(2+)-dependent secretagogues. Chelation of [Ca2+]i with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid inhibited the increases both in [Ca2+]i and Isc induced by carbachol with or without brief PMA pretreatment. Longer preincubations with PMA inhibited Isc responses to Ca(2+)-dependent secretagogues, even when increased [Ca2+]i was sustained by ionophores. Inhibitors of PKC could reverse the inhibitory effect of PMA but did not reverse the potentiating effect. The effects of PMA on Cl- secretion were reproduced by 1,2-dioctanoyl-sn-glycerol and were mirrored by effects on K+ channel opening. Thus PMA has dual effects on chloride secretion. Initially, it exerts a stimulatory action and subsequently an inhibitory action. The stimulatory effect only occurs if Ca(2+)-dependent secretion is ongoing. The inhibitory effect of PMA is mediated by PKC and cannot be overcome by increasing [Ca2+]i.