Christian Peiser

SMAD-signaling in chronic obstructive pulmonary disease: transcriptional down-regulation of inhibitory SMAD 6 and 7 by cigarette smoke.

Abstract Transforming growth factor-β1 is a potent mediator of fibrosis stimulating the secretion of extracellular matrix proteins and is involved in airway remodeling in chronic obstructive pulmonary disease (COPD). Signals from the TGF superfamily are mediated by the SMAD group of transcription factors. Here, the expression of the regulatory SMAD2, 3, the co-SMAD4 and the inhibitory SMAD6 and 7 was assessed in bronchial biopsies of COPD patients and controls by quantitative RTPCR. While SMAD2 was not expressed and SMAD3 and 4 displayed no change, the inhibitory SMAD6 and 7 were significantly downregulated in COPD. To reveal the molecular basis of tobacco smoke-induced airway remodeling and to test whether it may interfere with intracellular SMAD signaling, the airway epithelial cell line A549 was incubated with cigarette smoke extract (1% and 10%) for 48 hours, which led to down-regulation of SMAD6 and 7 at both concentrations tested. It can be concluded that TGF-β-mediated effects in COPD are influenced by a disturbed intracellular feedback mechanism of inhibitory SMADs. Also, the effects of non-volatile components in tobacco smoke may partly be regulated via a smoke-induced down-regulation of inhibitory SMADs.

Nerve growth factor‐induced substance P in capsaicin‐insensitive vagal neurons innervating the lower mouse airway

Background Nerve growth factor (NGF) is elevated in allergic diseases such as bronchial asthma and can lead to an induction of substance P (SP) and related neuropeptides in guinea‐pigs large‐diameter, neurofilament‐positive airway neurons.

Heme oxygenase is downregulated in stress-triggered and interleukin-12-mediated murine abortion.

Heme oxygenases (HOs) are responsible for heme degradation. Besides their enzymatic activities, HOs are involved in tissue protection. Failing upregulation of HOs has been linked to increased necrosis in inflammatory tissues. Interestingly, previously published data indicated that mice exposed to sonic stress during early gestation show an augmented production of decidual inflammatory T‐helper 1 (Th1) cytokines, thus resulting in increased abortion rate. No data linked the Th1‐inducer interleukin (IL)‐12 with the event of abortion. As little is known about the role of HO in pregnancy maintenance, we evaluated the expression of decidual and placental HO‐1 and HO‐2 in the abortion‐prone murine mating combination CBA/J × DBA/2 J with (1) CBA/J female control mice, (2) CBA/J mice exposed to stress during early gestation and (3) CBA/J females injected with recombinant IL‐12. Decidual and placental HOs protein expression was analysed by immunohistochemistry and mRNA levels by real time polymerase chain reaction (PCR).

Phenotypic alteration of neuropeptide‐containing nerve fibres in seasonal intermittent allergic rhinitis

Background Allergic rhinitis (AR) is the most common allergic disease affecting the respiratory tract. Next to inflammatory changes, the airway innervation plays an important modulatory role in the pathogenesis of the disease.

Innervation of human nasal mucosa in environmentally triggered hyperreflectoric rhinitis

Hyperreflectoric rhinitis is related to an unspecific hyperreactivity probably caused by chemical irritants. As a major modulatory role may be attributed to the mucosal innervation, the present study was carried out to examine possible changes in the nasal mucosa innervation. Immunohistochemistry for the neuropeptides vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide tyrosine (NPY) revealed abundant staining of nerve fibers. Neuropeptide-contents in mucosal nerves was then quantitatively assessed and significant increases were found for SP (3.00 ± 0.37 vs. 1.64 ± 0.34 control group staining intensity) and VIP (2.33 ± 0.42 vs. 0.82 ± 0.33). In conclusion, these findings demonstrated differences in human nasal mucosa innervation between nonrhinitic and hyperreflectoric rhinitic subjects and provide evidence for a modulatory participation of neuropeptide-specific subpopulations of nerve fibers in hyperreflectoric rhinitis.

Neuronal plasticity in persistent perennial allergic rhinitis.

Objective:Persistent perennial allergic rhinitis belongs to the most frequent diseases in occupational and environmental medicine. Because the innervation may play a role in the pathogenesis of the disease, the present study analyzed nasal mucosal nerve profiles. Methods:Neuropeptide-containing nerve fibers were examined using immunohistochemistry and related to eosinophil and mast cell numbers. Results:In contrast to constant numbers of mast cells, there was a significant increase in the number of eosinophils. Immunohistochemistry for calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and neuropeptide tyrosine (NPY) revealed abundant staining of mucosal nerves. Semiquantitative assessment of nerve fiber neuropeptide density demonstrated a significant increase of VIP-positive fibers in rhinitis tissues. Conclusions:The present data indicate a differential regulation of neuropeptide-containing nerve fibers with increased numbers of VIPergic fibers suggesting a modulatory role of the upper airway innervation in perennial allergic rhinitis.

Simultaneous detection of receptor mRNA and ligand protein in human skin tissues

Background:  In situ hybridization techniques allow a cell‐type‐specific messenger RNA (mRNA) analysis in complex tissues such as human skin.

Toxic Rhinitis-Induced Changes of Human Nasal Mucosa Innervation

Irritative toxic rhinitis is a nasal disorder induced by chemical compounds like ozone, formaldehyde, nickel, chrome, solvents and tobacco smoke. These noxious stimuli may have effects on the nasal innervation leading to a cascade of neuro-immune interactions and an augmentation of the symptoms. Here we examined changes in the neuropeptide content of mucosal parasympathetic, sympathetic and sensory nerves of patients with toxic rhinitis caused by chronic cigarette smoke exposure. Semiquantitative immunohistochemistry using antibodies against calcitonin gene-related peptide (CGRP), substance P (SP), neuropeptide tyrosine (NPY), and vasoactive intestinal peptide (VIP) was carried out on cryostat sections of human nasal mucosa obtained from normal subjects and patients with toxic rhinitis and revealed significant differences between both groups. Toxic rhinitis patients had significantly elevated expression scores for VIP (2.83 ± 0.31 vs 1.27 ± 0.47 control group) and NPY (3.17 ± 0.31 vs 0.91 ± 0.37 control group) revealing an increase of mediators in distinct subpopulations of airway nerves. In summary, the present studies indicate a differential participation of subclasses of mucosal nerves in the pathophysiology of toxic rhinitis. Airway innervation may have a major role in the pathophysiology of toxic rhinitis associated with chronic cigarette smoke exposure.

Expression of substance P and nitric oxide synthase in vagal sensory neurons innervating the mouse airways

INTRODUCTION Airway sensory nerves have the capacity to release neuromediators such as substance P and nitric oxide to control airway functions. The aim of the present study was to investigate substance P and neuronal nitric oxide synthase (NOS-1) expression in airway-specific sensory neurons. METHODS Airway-projecting neurons in the jugular-nodose ganglia were investigated for NOS-1 and substance P expression by neuronal tracing and double-labelling immunoreactivity. RESULTS Of the Fast blue labelled neurons, 14.6+/-1.8% (mean+/-S.E.M.) were immunoreactive only for NOS-1, 3.0+/-0.3% for NOS-1 and substance P, 2.7+/-0.3% only for substance P, and 79.7+/-1.7% of the labelled neurons were nonimmunoreactive for substance P or NOS-1 but were partly positive for I-B4-lectin-binding. Fast blue labelled NOS and/or substance P-positive neurons were small to medium sized (<20 microm). CONCLUSION Based on the expression of substance P and nitric oxide synthase in airway neurons, the present study suggests that there may be substance P and NO biosynthesis and release following a peripheral activation of the afferents, there could be a triggering of substance P and NO-mediated phenomena, including those related to airway inflammation, such as plasma extravasation and vasodilatation.

Transcriptional down-regulation of neurotrophin-3 in chronic obstructive pulmonary disease.

Abstract Chronic obstructive pulmonary disease (COPD) leads to progressive development of airflow limitation and is characterised by cough, mucus hypersecretion and inflammatory changes. These characteristic features of the disease may be modulated by neural mediators such as neurotrophins (NT). Here we examined the expression and transcriptional regulation of neurotrophins in bronchial biopsies of COPD patients and compared the data to control biopsies. Histology revealed characteristic changes in the COPD tissues, including remodelling of the epithelial lining. RT-PCR demonstrated the mRNA expression of neurotrophins in all biopsies. Immunohistochemistry confirmed the expression of different proteins. To assess changes in the transcriptional expression level, quantitative real-time PCR was carried out and revealed differential mRNA expression of neurotrophins, with marked down-regulation of NT-3 mRNA expression and constant levels of nerve growth factor (NGF), brain-derived nerve factor (BDNF), and NT-4/5 mRNA expression. The present data on neurotrophin-specific transcriptional down-regulation of NT-3 in human COPD indicate a pathophysiological role for neurotrophins in COPD.