[Guidelines of the German Respiratory Society for Diagnosis and Treatment of Adults Suffering from Acute, Subacute and Chronic Cough]. / Leitlinie der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin zur Diagnostik und Therapie von erwachsenen Patienten mit Husten.

The present 2019 S2k consensus guideline of the German Respiratory Society was written - in contrast to the predecessor more general S3 guidelines from 2004 and 2010 - for pneumologists, since 2014 the German College of General Practitioners and Family Physicians (DEGAM) published his own cough guidelines.The guideline contains 48 recommendations agreed by consensus and 16 statements, which are explained in the background text in the following nine chapters: epidemiology, physiology, classification, acute, subacute or chronic cough, diagnostics and therapy; an extra chapter was dedicated to chronic idiopathic cough. Further emphasis of the guideline is the physiology of cough in anticipation of the introduction of new drugs, as well as detailed treatises on cough triggered by affections in the upper respiratory tract or by gastroesophageal reflux. The guideline should provide the pneumologist with the latest knowledge from neighboring disciplines required for diagnosis and therapy of cough. The clinical chapters also contain a short summary, practical recommendations and a bibliography of their own. Three new, simplified algorithms for acute, subacute and chronic cough round off the Diagnostics chapter.

[Pathophysiology, diagnostics and therapy of chronic cough: neuronal reflexes and antitussiva]. / Pathophysiologie, Diagnostik und Therapie von chronischem Husten: Neuronale Reflexe und Antitussiva.

Cough is the number one symptom for patients to visit a physician worldwide. It is an important neuronal reflex which serves to protect the airways from inhaled exogenous microorganisms, thermal and chemical irritants. Moreover, it prevents the airways from mucus retention.The cough reflex is initiated by activation of different cough receptors. These cough receptors can be divided into three groups according to their electrophysiological properties: into the two Aδ-fiber types "rapid-adapting mechanoreceptor" (RAR) and "slow-adapting mechanoreceptor" (SAR), and the C-fiber receptor.The stimulus is detected by cough receptors which conduct the signal to the cerebral cough centre via vagal-sensory neurons. The cough itself is mediated by efferent motoneurons. Hence the cough reflex consists of 5 functionally sequential parts 1: the cough receptors 2, the primary afferent fibres of the N. vagus 345, N. trigeminus and N. glossopharyngeus 1, the cough centre in the medulla oblongata (N. tractus solitarius) 678, the afferent fibres of the N. phrenicus, spinal nerve and N. laryngeus recurrens, as well as the diaphragm and the abdominal, intercostal and laryngeal muscles. The cough receptors are mainly located in the larynx, trachea and main bronchi 2.The event of coughing can be divided into four subsequent parts: After the first phase of fast inspiration with an opened glottis, there is compression with a closed glottis and increasing tracheal pressure, acceleration and ultimately maximum expiration with an opened glottis 9. According to its characteristics, cough can be split into two distinct types, "aspiration cough", which is loud and involuntary, and "urge-to-cough sensation", which describes an irritant, scratchy, and controlled cough of slowly increasing intensity 10.Acute cough mostly develops because of infection of the respiratory system 111213 and ends spontaneously after 4 weeks. In contrast to this, bacterial infection with pathogens like Adenovirus, Bordetella pertussis and Mycoplasms can last up to 8 weeks 121314. In additional to the division of cough according to its cause, it can also be differentiated according to its manner: dry and mucus-producing cough.With this review we want to give an overview of neuronal processes and mechanisms, as well as diagnostics of and therapy for chronic cough. Thereby the focus is also placed on the efficiency of already established and potential future antitussive agents.

[Innervation of the airways in asthma bronchiale and chronic obstructive pulmonary disease (COPD)]. / Neuronale Kontrolle bei chronisch entzündlichen und obstruktiven Lungenerkrankungen wie Asthma bronchiale und COPD.

Airway nerves have the capacity to control airway functions via neuronal reflexes and through neuromediators and neuropeptides. Neuronal mechanisms are known to play a key role in the initiation and modulation of airway hyperresponsiveness and inflammation. Therefore, the nerve fibres may contribute to airway narrowing in asthma and COPD. In addition to the traditional transmitters such as norepinephrine in postganglionic sympathetic nerve fibres and acetylcholine in parasympathetic nerve fibres, a large number of neuropeptides have been identified to have different pharmacological effects on the muscle tone of the vessels and bronchi, mucus secretion and immune cells. Meanwhile, a broad range of stimuli including capsaicin, bradykinin, hyperosmolar saline, tobacco smoke, allergens, ozone, inflammatory mediators and even cold, dry air have been shown to activate sensory nerve fibres to release neuropeptides such as the tachykinins substance P (SP) and neurokinin A (NKA) to mediate neurogenic inflammation. Different aspects of the neurogenic inflammation have been well studied in animal models of chronic airway inflammation and anticholinergic agents such as ipratropium bromide (Atrovent (®)) and tiotropium bromide (Spiriva (®)) have been proved to be important when used as bronchodilators for the treatment of obstructive airway diseases such as COPD. However, little is known about the role of neurogenic airway inflammation in human diseases. In this review, we address the current knowledge of the airway sensory nerves in human asthma and COPD.

Catheter fragmentation and local lysis in two lung transplant patients with pulmonary embolism.

In conjunction with the rising number of lung transplant operations in the past decade, an increased predisposition to venous thrombosis (VT), particularly within the first year posttransplantation has been observed. Previous studies have revealed that between 8.6% and 12% of patients develop VT, which can ultimately result in pulmonary emboli (PE).Transplanted lungs pose a much greater infarction risk due to their lack of collateral vascularisation, relying entirely on the vasa publica--the pulmonary artery--in the absence of vasa privata. Such losses in viable lung parenchyma are always serious, but carry still greater risks for single-lung transplant recipients, an early diagnosis and treatment remain critical. Here we report on two cases of PE after lung transplantation, both of whom were managed with catheter fragmentation and local thrombolysis. In our opinion, this approach represents a viable treatment for symptomatic PE in lung transplant recipients. The benefits and risks of the alternative treatment options in these special cases will be reviewed and the definitive therapy was described. In the patients treated, catheter fragmentation with localized thrombolysis resulted in short term improvements in graft function, but could not prevent later lung infarction in one case.

German Respiratory Society guidelines for diagnosis and treatment of adults suffering from acute, subacute and chronic cough.

The present 2019 S2k consensus guideline of the German Respiratory Society was written for pneumologists - in contrast to the more general predecessor's S3 guidelines from 2004 to 2010 -, since 2014 the German College of General Practitioners and Family Physicians (DEGAM) published their own cough guidelines. The guidelines contain 48 recommendations agreed upon the consensus and 16 statements, which are explained in the background text in the following nine chapters: epidemiology, physiology, classification, acute, subacute or chronic cough, diagnostics and therapy; an extra chapter was dedicated to chronic idiopathic/refractory cough. Further emphasis of the guidelines is the physiology of cough in anticipation of the introduction of new drugs, as well as detailed treatment for cough triggered by affectations of the upper respiratory tract or gastroesophageal reflux. The guideline should provide the pneumologist with the latest knowledge for neighboring disciplines required for diagnosis and therapy of cough. The clinical chapters also contain a short summary, practical recommendations and a bibliography of their own. Three new simplified algorithms for acute, subacute and chronic cough, round off the diagnostics chapter.

Selective induction of nerve growth factor and brain-derived neurotrophic factor by LPS and allergen in dendritic cells.

BACKGROUND: Neurotrophins are produced by various cells upon different stimuli and participate in the initiation and regulation of inflammation in various diseases including allergy and asthma, but little is known about the production and control of neurotrophins by dendritic cells (DCs). The aim of this study was to assess whether DCs produce the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), and whether inflammatory stimuli or allergens are able to induce the production of neurotrophic factors. METHODS: Monocyte-derived dendritic cells (MoDCs) were generated from different donors. The neurotrophins NGF and BDNF were demonstrated by RT-PCR, Western blotting, flow cytometry analysis and fluorescence microscopy. MoDCs were cultured and stimulated with lipopolysaccharide (LPS) or allergen for 24 h. The supernatants and cells were collected. Measurement for NGF and BDNF was performed by ELISA. RESULTS: DCs express mRNA for the neurotrophins NGF and BDNF. Proteins were detectable by Western blot, FACS analysis and fluorescence microscopy. LPS led to an up-regulation of BDNF, while NGF was unaffected. Cell lysates demonstrated an increased amount of BDNF after stimulation with LPS or allergen, while NGF was not affected significantly. CONCLUSIONS: DCs are a source of neurotrophins. LPS selectively regulates the production of BDNF. Allergen stimulation leads to an LPS-independent regulation. This contributes to a complex involvement of neurotrophins in allergic diseases.

Trigeminal nasal-specific neurons respond to nerve growth factor with substance-P biosynthesis.

BACKGROUND: Nerve growth factor (NGF) has been found to induce substance-P biosynthesis in large-diameter A-fibres vagal airway neurons. However, the effect of NGF on trigeminal neurons innervating the nasal mucosa of the mouse has not been investigated so far. OBJECTIVE: NGF has been implicated in allergic diseases by modulating sensory nerves. Therefore, the present study investigated the effect of NGF on neuropeptides expression such as substance-P and glutamate in nasal trigeminal neurons. METHODS: Using neuronal tracing in combination with double labelling immunohistochemistry the expression of substance-P, glutamate and neurofilament protein 68-kDa expression was examined in nasal-specific trigeminal neurons of BALB/c-mice. RESULTS: The numbers of Fast blue-labelled trigeminal neurons expressing substance-P were significantly increased after NGF exposure (NGF-treated ganglia: 16.4 +/- 0.6% vs. control: 7.0 +/- 0.4%, P

Neurokinin-1 receptor activation induces reactive oxygen species and epithelial damage in allergic airway inflammation.

BACKGROUND: An induction of reactive oxygen species (ROS) is characteristic for inflammation but the exact pathways have not been identified for allergic airway diseases so far. OBJECTIVE: The aim of this study was to characterize the role of the tachykinin NK-1 receptor on ROS production during allergen challenge and subsequent inflammation and remodelling. METHODS: Precision-cut lung slices of ovalbumin (OVA)-sensitized mice were cultivated and ROS-generation in response to OVA challenge (10 microg/mL) was examined by the 2',7'-dichloroflourescein-diacetate method. Long-term ROS effects on epithelial proliferation were investigated by 5-bromo-2'-deoxyuridine incorporation (72 h). In vivo, the results were validated in OVA-sensitized animals which were treated intra-nasally with either placebo, the tachykinin neurokinin 1 (NK-1) receptor antagonist SR 140333 or the anti-oxidant N-acetylcystein (NAC) before allergen challenge. Inflammatory infiltration and remodelling were assessed 48 h after allergen challenge. RESULTS: ROS generation was increased by 3.7-fold, which was inhibited by SR 140333. [Sar(9),Met(11)(O(2))]-Substance P (5 nM) caused a tachykinin NK-1 receptor-dependent fourfold increase in ROS generation. Epithelial proliferation was decreased by 68% by incubation with [Sar(9),Met(11)(O(2))]-SP over 72 h. In-vivo, treatment with SR 140333 and NAC reduced epithelial damage (91.4% and 76.8% vs. placebo, respectively, P<0.01) and goblet cell hyperplasia (67.4% and 50.1% vs. placebo, respectively, P<0.05), and decreased inflammatory cell influx (65.3% and 45.3% vs. placebo, respectively, P<0.01). CONCLUSION: Allergen challenge induces ROS in a tachykinin NK-1 receptor-dependent manner. Inhibition of the tachykinin NK-1 receptor reduces epithelial damage and subsequent remodelling in vivo. Therefore, patients may possibly benefit from treatment regime that includes radical scavengers or tachykinin NK-1 receptor antagonists.

High probability of comorbidities in bronchial asthma in Germany.

Clinical experience has shown that allergic and non-allergic respiratory, metabolic, mental, and cardiovascular disorders sometimes coexist with bronchial asthma. However, no study has been carried out that calculates the chance of manifestation of these disorders with bronchial asthma in Saarland and Rhineland-Palatinate, Germany. Using ICD10 diagnoses from health care institutions, the present study systematically analyzed the co-prevalence and odds ratios of comorbidities in the asthma population in Germany. The odds ratios were adjusted for age and sex for all comorbidities for patients with asthma vs. without asthma. Bronchial asthma was strongly associated with allergic and with a lesser extent to non-allergic comorbidities: OR 7.02 (95%CI:6.83-7.22) for allergic rhinitis; OR 4.98 (95%CI:4.67-5.32) allergic conjunctivitis; OR 2.41 (95%CI:2.33-2.52) atopic dermatitis; OR 2.47 (95%CI:2.16-2.82) food allergy, and OR 1.69 (95%CI:1.61-1.78) drug allergy. Interestingly, increased ORs were found for respiratory diseases: 2.06 (95%CI:1.64-2.58) vocal dysfunction; 1.83 (95%CI:1.74-1.92) pneumonia; 1.78 (95%CI:1.73-1.84) sinusitis; 1.71 (95%CI:1.65-1.78) rhinopharyngitis; 2.55 (95%CI:2.03-3.19) obstructive sleep apnea; 1.42 (95%CI:1.25-1.61) pulmonary embolism, and 3.75 (95%CI:1.64-8.53) bronchopulmonary aspergillosis. Asthmatics also suffer from psychiatric, metabolic, cardiac or other comorbidities. Myocardial infarction (OR 0.86, 95%CI:0.79-0.94) did not coexist with asthma. Based on the calculated chances of manifestation for these comorbidities, especially allergic and respiratory, to a lesser extent also metabolic, cardiovascular, and mental disorders should be taken into consideration in the diagnostic and treatment strategy of bronchial asthma. BRONCHIAL ASTHMA: PREVALENCE OF CO-EXISTING DISEASES IN GERMANY: Patients in Germany with bronchial asthma are highly likely to suffer from co-existing diseases and their treatments should reflect this. Quoc Thai Dinh at Saarland University Hospital in Homburg, Germany, and co-workers conducted a large-scale study of patients presenting with bronchial asthma in the Saarland region between 2009 and 2012. Patients with asthma made up 5.4% of the region's total population, with a higher prevalence occurring in females. They found that bronchial asthma was strongly associated with allergic comorbidities such as rhinitis. Indeed, asthmatic patients had a seven times higher chance to suffer from allergic rhinitis than the rest of the population, and were at higher risk of respiratory diseases like pneumonia and obstructive sleep apnea syndrome. Further associations included cardiovascular, metabolic and mental disorders. Dinh's team call for asthma treatments to take such comorbidities into account.

Hymenoptera sting anaphylactic reactions in the Mediterranean population of Albania.

BACKGROUND: Relatively few studies have examined the relation of different hymenoptera sting reactions. OBJECTIVE: To investigate the relation of anaphylactic reactions against stings of different hymenoptera subspecies in the Mediterranean population of Albania. MATERIALS AND METHODS: A retrospective study was conducted using the clinic files of 111 patients who were diagnosed for hymenoptera sting reactions from 1987 to 1996. Antigens used consisted of purified hymenoptera venom (bee, wasp, and paperwasp). The patients were diagnosed by intracutaneous tests in concentrations of 0.001 microgram/ml, 0.01 microgram/ml, 0.1 microgram/ml, and 1 microgram/ml. RESULTS: The median age of the patients was 27 years. 57% of stings occurred between 20 to 40 years of age. The majority of anaphylactic reactions were recorded during the months of June to October, 81% of the patients were admitted to the hospital due to Mueller grade II to III reactions. In 26% of all cases, crossreactions (bee-wasp 16%, bee-wasp-paperwasp 7%, wasp-paperwasp 2%, bee-paperwasp 1%) were found. Of all anaphylactic reactions, 64% were attributed to bees, 24% to wasps, 8% to both bees and wasps, and 2% to paperwasps. CONCLUSIONS: In contrast to industrialized countries such as the United States or Western Europe where urban populations predominate, reactions to bee venom were more prevalent in the present study population.

Cell type-specific regulation of brain-derived neurotrophic factor in states of allergic inflammation.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a molecule influencing neuronal proliferation and differentiation. In states of allergy, it may orchestrate inflammatory changes by linking the immune system with the nervous system. Because the precise regulation of gene transcription in mast cells MCs is not clear, the present studies assessed the gene regulation of BDNF in this inflammatory cell type. METHODS: Transcriptional expression of BDNF in human skin was studied in isolated cells using RT-PCR. In situ lesional MC BDNF protein expression was analysed by immunohistochemistry and related to the differential staining of MCs and functional effects of BDNF on HaCaT keratinocytes. RESULTS: BDNF mRNA expression was found in isolated human skin MCs, keratinocytes, and fibroblasts. Also, low levels were found in endothelial cells and melanocytes. BDNF protein expression was found in situ in lesional and non-lesional MCs. A significantly decreased expression of BDNF protein was found in atopic dermatitis lesional MCs when compared with control MC expression. Functional in vitro experiments demonstrated that a decrease in BDNF stimulation led to increased secretion rates for stem cell factor and IL-8 in HaCaT keratinocytes. CONCLUSION: The demonstration of a decreased level of BDNF gene transcription in lesional MCs points to a differential regulation of MC-released neutrotrophins in cutaneous allergic inflammation. Topically administered neurotrophin receptor-modulating compounds should be receptor target specific and not universally acting in diseases such as atopic dermatitis or allergic asthma.

[Airway sensory nerve and tachykinins in asthma and COPD]. / Die sensible Atemwegsinnervation und die Tachykinine bei Asthma und chronisch-obstruktiver Lungenerkrankung (COPD).

The airway nerve has gained importance in the field of respiratory research as it is known to have the capacity to release numerous mediators which can cause pulmonary effects in the airways. Meanwhile, a broad range of stimuli including capsaicin, bradykinin, hyperosmolar saline, tobacco smoke, allergens, ozone, inflammatory mediators and cold dry air have been shown to activate sensory nerve fibres to release neuropeptides such as the tachykinins substance P (SP) and neurokinin A (NKA) to mediate neurogenic inflammation. SP is synthesized in cell bodies of airway neurons of the trigeminal, jugulare and nodose ganglia. Following their release, tachykinins are degraded by neutral endopeptidase (NEP) and an angiotensin-converting enzyme. Tachykinins have been proposed to play an important role in human respiratory diseases such as bronchial asthma und chronic obstructive diseases (COPD) as they have been shown to have potent effects on the tone of airway smooth muscle, airway secretions, bronchial circulation and on inflammatory and immune cells by activation of the neurokinin-1 (NK-1) and neurokinin-2 (NK-2) receptors. Recently, new tachykinins such as virokinin and hemokinin were identified and characterised. Different aspects of the neurogenic inflammation have been well studied in animal models of allergic airway inflammation, but only little is known about the role of neurogenic airway inflammation in human diseases. To address the precise role of tachykinins and airway sensory nerves in human asthma und COPD, experiments on sensory nerve sensitisation and neuro-immune interaction have to be carried out in future studies.

Stress induces substance P in vagal sensory neurons innervating the mouse airways.

BACKGROUND: Tachykinins-like substance P (SP) have been shown to play an important role in initiating and perpetuating airway inflammation. Furthermore, they are supposed to be released into tissues in response to stress. OBJECTIVE: The aim of this study was to investigate the effects of stress alone or in combination with allergic airway inflammation on SP expression in sensory neurons innervating the mouse airways. METHODS: Balb/c mice were systemically sensitized to ovalbumin (OVA), followed by allergen aerosol exposure, and compared with non-sensitized controls. Additionally, OVA-sensitized and -challenged and non-sensitized mice were exposed to sound stress. SP expression in airway-specific and overall vagal sensory neurons of the jugular and nodose ganglion complex was analysed using retrograde neuronal tracing in combination with immunohistochemistry. Preprotachykinin A (PPT-A) mRNA, the precursor for SP, was quantified in lung tissue by real-time PCR. Bronchoalveolar lavage (BAL) fluid was obtained, and cell numbers and differentiation were determined. RESULTS: Stress and/or allergic airway inflammation significantly increased SP expression in retrograde-labelled vagal sensory neurons from the mouse lower airways compared with controls [stress: 15.7+/-0.8% (% of retrograde-labelled neurons, mean+/-SEM); allergen: 17.9+/-0.4%; allergen/stress: 13.1+/-0.7% vs. controls: 6.3+/-0.3%]. Similarly, SP expression increased in overall vagal sensory neurons identified by the neuronal marker protein gene product (PGP) 9.5 [stress: 9.3+/-0.6% (% of PGP 9.5-positive neurons, means+/-SEM); allergen: 12.5+/-0.4%; allergen/stress: 10.2+/-0.4% vs. controls: 5.1+/-0.3%]. Furthermore, stress significantly increased PPT-A mRNA expression in lung tissue from OVA-sensitized and -challenged animals, and immune cells were identified as an additional source of SP in the lung by immunohistochemistry. Associated with enhanced neuronal SP expression, a significantly higher number of leucocytes were found in the BAL following allergen exposure. Further, stress significantly increased allergen-induced airway inflammation identified by increased leucocyte numbers in BAL fluids. CONCLUSION: The central event of sound stress leads to the stimulation of SP expression in airway-specific neurons. However, in sensitized stressed mice an additional local source of SP (probably inflammatory cells) might enhance allergic airway inflammation.

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.

Allergic airway inflammation induces tachykinin peptides expression in vagal sensory neurons innervating mouse airways.

BACKGROUND: Allergic airway inflammation has been shown to induce pro-inflammatory neuropeptides such as tachykinin peptides substance P (SP) and neurokinin A (NKA) together with related peptide like calcitonin gene-related peptide (CGRP) in nodose sensory neurons innervating guinea-pig airways. OBJECTIVE: The present study was designed to examine the effects of allergen sensitization and challenge on the SP/NKA expression in the jugular-nodose ganglion neurons innervating the murine airways. METHODS: Using retrograde neuronal tracing technique in combination with double-labelling immunohistochemistry, the expression of SP/NKA was investigated in a murine model of allergic airway inflammation. RESULTS: Allergic airway inflammation was found to induce the expression of SP/NKA (13.2+/-1.43% vs. 5.8+/-0.37%, P<0.01) in large-diameter (>20 microm) vagal sensory neurons retrograde labelled with Fast blue dye from the main stem bronchi. CONCLUSION: Based on the induction of tachykinins in airway-specific large-sized jugular-nodose ganglia neurons by allergic airway inflammation, the present study suggests that allergen sensitization and challenge may lead to de novo induction of tachykinins in neurons. This may partly contribute to the pathogenesis of airways diseases such as allergic airway inflammation.

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.

Expression and distribution of vasoactive intestinal polypeptide receptor VPAC(2) mRNA in human airways.

SUMMARY: Vasoactive intestinal polypeptide (VIP) is a putative neurotransmitter of the inhibitory non-adrenergic non-cholinergic nervous system and influences many aspects of mammalian airway function. VIP binds to two G-protein-coupled VPAC receptors that are highly homologous structurally but distinguished by their different affinities for peptide analogues of VIP. As VIP binding sites in the respiratory tract have only been examined by ligand binding and cytochemical techniques, we studied the distribution of the mRNA that encodes the inducible receptor subtype VPAC(2) in the human respiratory tract. Northern blots demonstrated the expression of VPAC(2) mRNA in human airways and other tissues. A human-specific VPAC(2) cRNA probe was used to detect VPAC(2) mRNA expression in human lung by nonradioactive in situ hybridization. In larger airways, positive VPAC(2) mRNA signals were localized to tracheal and bronchial ciliated epithelial cells. There was also marked staining of mucous and serous cells of submucosal glands. No signals were obtained in airway and vascular smooth muscle myocytes and endothelial cells. In peripheral lung tissues, VPAC(2) mRNA expression was localized to epithelial cells of the bronchioles. Specific staining was detected in immune cells and alveolar macrophages. In summary, VPAC(2) is localized in airway epithelial, glandular, and immune cells of the lung but not in airway and vascular smooth muscle. The absence of VPAC(2) mRNA in vascular and airway smooth muscle myocytes may indicate that the effects of VIP on vasodilation and bronchodilation are mediated by VPAC(1) or undefined receptors. However, a paracrine modulation of the two most prominent effects of VIP in the respiratory tract by VPAC(2) cannot be excluded.

Abundant expression of c-Jun in guinea pig sympathetic ganglia under basal conditions and allergen challenge.

Airway hyperresponsiveness, a keystone of allergic asthma, is mediated by the extrinsic airway innervation. As pathophysiological stimuli can induce the expression JUN proteins, which belong to the immediate early gene (IEG) family of transcription factors, the expression of c-Jun was examined under basal conditions and allergen challenge in guinea pig paravertebral and prevertebral sympathetic ganglia by quantitative double-labeling immunohistochemistry. C-Jun immunoreactivity was seen in 78.4 +/- 3.5% under normal and 82.6 +/- 4.6% under allergen-challenged conditions of protein-gene product (PGP) 9.5-positive sympathetic neurons of guinea pig superior cervical ganglia and 73.1 +/- 2.8% (normal) and 76.1 +/- 3.5% (allergen) of stellate ganglion neurons. In the coeliac-superior mesenteric ganglion, 59.5 +/- 5.0% (normal) and 57.5 +/- 4.4% (allergen) of the PGP 9.5-positive sympathetic neurons were labeled for c-Jun. The high basal levels of c-Jun expression indicate that the presence of c-Jun is not exclusively related to noxious stimulation such as allergic airway inflammation in the guinea pig.