M(3) muscarinic receptor antagonist bencycloquidium bromide attenuates allergic airway inflammation, hyperresponsiveness and remodeling in mice

ROS responsive hydrogel for inhibition of MUC5AC against allergic rhinitis: A new delivery strategy for Ipratropium Bromide

Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa mediated by immunoglobulin E (IgE) after exposure to allergens. The bothersome symptoms of AR, such as runny nose and nasal congestion, affect millions of people worldwide. Ipratropium Bromide (IB), commonly used in clinical practice for treating AR, requires frequent administration through nasal spray and may cause significant irritation to the nasal mucosa. The induction of ROS is closely related to the initiation and symptoms of AR, and ROS will continue to accumulate during the onset of AR. To address these challenges, we have designed a drug delivery system that can be administered in liquid form and rapidly crosslink into a ROS-responsive gel in the nasal cavity. This system enables sustained ROS responsive release of IB in a high-concentration ROS environment at AR lesions, thereby alleviating AR symptoms. The gel demonstrated prolonged release of IB for up to 24 hours in rats. In the treatment of AR rat models, it improved their symptoms, reduced the expression of various inflammatory factors, suppressed MUC5AC protein expression, and decreased mucus secretion through a ROS responsive IB release pattern. Overall, this system holds promise as a better option for AR treatment and may inspire the design of nanogel-based nasal drug delivery systems.

Intermittent hypoxic pretreatment exacerbates house dust mite-induced asthma airway inflammation

BACKGROUND

Asthma is widely recognized as an inflammatory disorder. In the context of this inflammatory microenvironment, the involvement of hypoxia and its impact on related pathways have drawn considerable attention. However, the exact role of hypoxia, a prevalent environmental factor, in the development and progression of asthma remains poorly understood.

METHODS

Mice were treated with house dust mite (HDM) extracts for 23 days to induce asthma. Mice were divided into room air (RA) group and intermittent hypoxic (IH) group by exposing to different conditions and IH preconditioning (IHP) were underwent to the above groups before the hypoxic regimen. Airway inflammation in mice was evaluated by airway hyperresponsiveness, excessive mucus secretion, and recruitment of inflammatory cells. Immunohistochemistry was employed to quantify the expression levels of NF-κB. Subsequently, the dose of allergen was modified to investigate whether the impact of hypoxia on asthma is affected by different doses of allergens.

RESULT

Compared to the RA and IH groups, HDM-treated mice in the IHP group exhibited aggravated inflammatory cell infiltration and airway hyperresponsiveness (p＜.05). Moreover, there was an increased release of inflammatory mediators and higher expression levels of NF-κB (p＜.05). Importantly, the impact ia on asthma was found to be influenced by high dose of allergen (p＜.05).

CONCLUSION

IHP treatment potentially exacerbates HDM-induced airway inflammation in asthma, with the involvement of NF-κB, particularly under high-dose allergen stimulation.

Combined application of multiple biomarkers for early auxiliary diagnosis of silicosis

Silicosis is an important industrial health problem for those workers exposed to silica. The present study aimed to investigate the sensitivity and specificity of combined detection of biomarkers in early auxiliary diagnosis of silicosis, the risk factors of silicosis were also studied. The study sample comprised 65 workers who had clinical silicosis and 70 matched control subjects who were exposed to silica but did not have clinical silicosis. The levels of superoxide dismutase, malondialdehyde, interleukin 6 (IL-6), tumor necrosis factor-alpha, and cholinesterases in the serum of 135 subjects were measured. After completing the biochemical assays, a logistic regression model based on the above biochemical determination results was established, and the receiver operating characteristic curve was used for judging the discrimination ability of different statistical indexes. The expression levels of MDA, IL-6, and TNF-alpha in serum samples of patients with stage I silicosis and MDA and IL-6 in serum samples of patients with stage II silicosis were all significantly higher. Results from logistic regression analysis showed that ChEs were protective factors for silicosis, while age, chronic respiratory symptoms, IL-6, and MDA were risk factors. The areas under the ROC curve (AUC) were 0.86 (IL-6), 0.81 (MDA), and 0.65 (TNF-alpha or ChEs). AUC-ROC = 0.90 (95%CI:0.84-0.95). The diagnostic efficiency of IL-6 combined with MDA and TNF-alpha was better than that of any single biomarker.

Muscarinic receptor antagonists and airway inflammation: A systematic review on pharmacological models

Airway inflammation is crucial in the pathogenesis of many respiratory diseases, including chronic obstructive pulmonary disease (COPD) and asthma. Current evidence supports the beneficial impact of muscarinic receptor antagonists against airway inflammation from bench-to-bedside. Considering the numerous sampling approaches and the ethical implications required to study inflammation in vivo in patients, the use of pre-clinical models is inevitable. Starting from our recently published systematic review concerning the impact of muscarinic antagonists, we have systematically assessed the current pharmacological models of airway inflammation and provided an overview on the advances in in vitro and ex vivo approaches. The purpose of in vitro models is to recapitulate selected pathophysiological parameters or processes that are crucial to the development of new drugs within a controlled environment. Nevertheless, immortalized cell lines or primary airway cells present major limitations, including the inability to fully replicate the conditions of the corresponding cell types within a whole organism.

Induced animal models are extensively used in research in the attempt to replicate a respiratory condition reflective of a human pathological state, although considering animal models with spontaneously occurring respiratory diseases may be more appropriate since most of the clinical features are accompanied by lung pathology resembling that of the human condition.

In recent years, three-dimensional organoids have become an alternative to animal experiments, also because animal models are unable to fully mimic the complexity of human pulmonary diseases. Ex vivo studies performed on human isolated airways have a superior translational value compared to in vitro and animal models, as they retain the morphology and the microenvironment of the lung in vivo.

In the foreseeable future, greater effort should be undertaken to rely on more physiologically relevant models, that provide translational value into clinic and have a direct impact on patient outcomes.

IL-33 amplifies airways inflammation in a murine surrogate of asthma putatively via activation of dendritic cells

Although contributions of IL-33 to pulmonary diseases, including asthma, have been well documented, the complexity of such regulation warrants additional exploration. To better understand the involvement of IL-33, we used a murine asthma surrogate based on sensitisation and challenge with dust mite extract in the presence/absence of IL-33. Murine models were established with Dermatophagoides farinae (Der f) to establish (1) the effect of co-administered rmIL-33; (2) the effect of prior glucocorticoid intervention; (3) the effect of IL-33 on challenge with sub-threshold dosage Der f. The effects of rmIL-33 on bone marrow-derived dendritic cells were explored in vitro. Mice challenged with Der f combined with IL-33 compared with diluent control evinced significantly more airways inflammation and local cytokine production which was less sensitive to inhibition by dexamethasone. IL-33 also induced airways hyperresponsiveness, eosinophilic inflammation and cytokine production in lung tissues of animals exposed to sub-threshold dosage of Der f. In vitro, IL-33-stimulated DCs showed a significantly elevated capacity to stimulate CD4⁺ T cell proliferation and cytokine production and were also significantly more resistant to dexamethasone-induced apoptosis. Our data suggest that IL-33 reduces the threshold for allergen-induced inflammation of the airways in acorticosteroid-resistant fashion possibly in part through acting on DCs, a phenomenon which may be relevant to the development of severe, corticosteroid-resistant airways obstruction in human asthmatic patients.

IRAK-M knockout promotes allergic airway inflammation, but not airway hyperresponsiveness, in house dust mite-induced experimental asthma model

Background

IL-1 receptor associated-kinase (IRAK)-M, expressed by airway epithelium and macrophages, was shown to regulate acute and chronic airway inflammation exhibiting a biphasic response in an OVA-based animal model. House dust mite (HDM) is a common real-life aeroallergen highly relevant to asthma pathogenesis. The role of IRAK-M in HDM-induced asthma remains unknown. This study was aimed to investigate the effect of IRAK-M on allergic airway inflammation induced by HDM using IRAK-M knockout (KO) mice and the potential underlying mechanisms.

Methods

IRAK-M KO and wild-type (WT) mice were sensitized and challenged with HDM. The differences in airway inflammation were evaluated 24 hours after the last challenge between the two genotypes of mice using a number of cellular and molecular biological techniques. In vitro mechanistic investigation was also involved.

Results

Lung expression of IRAK-M was significantly upregulated by HDM in the WT mice. Compared with the WT controls, HDM-treated IRAK-M KO mice showed exacerbated infiltration of inflammatory cells, particularly Th2 cells, in the airways and mucus overproduction, higher epithelial mediators IL-25, IL-33 and TSLP and Th2 cytokines in bronchoalveolar lavage (BAL) fluid. Lung IRAK-M KO macrophages expressed higher percentage of costimulatory molecules OX40L and CD 80 and exhibited enhanced antigen uptake. However, IRAK-M KO didn’t impact the airway hyperreactivity (AHR) indirectly induced by HDM.

Conclusions

The findings indicate that IRAK-M protects allergic airway inflammation, not AHR, by modifying activation and antigen uptake of lung macrophages following HDM stimulation. Optimal regulation of IRAK-M might indicate an intriguing therapeutic avenue for allergic airway inflammation.

The Impact of Muscarinic Receptor Antagonists on Airway Inflammation: A Systematic Review

Long-acting muscarinic receptor antagonists (LAMAs) are the cornerstone for the treatment of chronic obstructive pulmonary disease (COPD); furthermore, tiotropium is approved as add-on therapy in severe asthmatic patients. Accumulating evidence suggests that LAMAs may modulate airway contractility and airway hyperresponsiveness not only by blocking muscarinic acetylcholine receptors (mAchRs) expressed on airway smooth muscle but also via anti-inflammatory mechanisms by blocking mAchRs expressed on inflammatory cells, submucosal glands, and epithelial cells. The aim of this systematic review, performed according to the PRISMA-P guidelines, was to provide a synthesis of the literature on the anti-inflammatory impact of muscarinic receptor antagonists in the airways. Most of the current evidence originates from studies on tiotropium, that demonstrated a reduction in synthesis and release of cytokines and chemokines, as well as the number of total and differential inflammatory cells, induced by different pro-inflammatory stimuli. Conversely, few data are currently available for aclidinium and glycopyrronium, whereas no studies on the potential anti-inflammatory effect of umeclidinium have been reported. Overall, a large body of evidence supports the beneficial impact of tiotropium against airway inflammation. Further well-designed randomized controlled trials are needed to better elucidate the anti-inflammatory mechanisms leading to the protective effect of LAMAs against exacerbations via identifying suitable biomarkers.

Safety, Tolerability and Pharmacokinetics of Bencycloquidium Bromide, a Novel Inhaled Anticholinergic Bronchodilator, in Healthy Subjects: Results from Phase I Studies

BACKGROUND

Bencycloquidium bromide (BCQB) is a novel inhaled anticholinergic bronchodilator with high selectivity for muscarinic M3 receptor. BCQB's potential utility of for therapy in Chronic obstructive pulmonary disease (COPD) has been indicated in pre-clinical studies.

PURPOSE

To investigate the initial safety, tolerability and pharmacokinetics of BCQB delivered via pressurised Metered Dose Inhaler (pMDI) in healthy subjects.

METHODS

This study consisted of single-ascending-dose (SAD), multiple-ascending-dose (MAD) tolerability study periods, and single- plus multiple-dose pharmacokinetic study periods. Randomized, double-blind, placebo-controlled, dose-escalating tolerability and pharmacokinetic studies were conducted. Seventy-two healthy subjects were assigned 3:1 (BCQB: placebo) to 7 single-dose cohorts (125, 250, 500, 750, 1125, 1500 and 2000 μg) and 2 multiple-dose cohorts (1500 μg/d and 2000 μg/d). In the pharmacokinetic periods, 12 subjects were allocated three-way crossover to receive single dose of 250, 750 or 2000 μg BCQB, respectively. Subsequently, the same 12 subjects received multiple dose of 750 μg/d and 1000 μg/d for 7 days. Pharmacokinetic, safety and tolerability assessments were performed.

RESULTS

BCQB administered by inhalation was well tolerated, especially with favorable cardiovascular safety profile. BCQB was rapidly absorbed into plasma after inhalation through pMDI, with peak concentrations achieved within 5 to 10 minutes. Repeated inhalation caused certain degree of accumulation with the accumulation ratio R_Cmax 2.50, R_AUC 3.49 for 3 times-a-day and R_Cmax 2.23, R_AUC 3.44 for 4 times-a-day, respectively. Twice-a-day or even once-a-day dosage could be suggested in phase II study. Sex didn't affect the pharmacokinetics of BCQB and dose adjustments based on sex is not anticipated in clinical use. Approximately 4% of the BCQB dose excreted unchanged in urine and liver metabolism is the main biotransformation route of BCQB in human.

CONCLUSIONS

The results of our study provided the initial safety, tolerability and pharmacokinetic profiles of BCQB inhalation, and could enable further clinical development in COPD patients.

Biochanin A Ameliorates Ovalbumin-induced Airway Inflammation through Peroxisome Proliferator-Activated Receptor-Gamma in a Mouse Model

OBJECTIVE

Asthma is an inflammatory airway disease affecting most of the population in the world. The current medication for asthma relieves airway inflammation but it has serious adverse effects. Biochanin A (BCA), a phytoestrogen, is an active component present in red clover, alfalfa, soy having anti-oxidant and anti-inflammatory properties. BCA was identified as a natural activator of peroxisome proliferator-activated receptor-gamma (PPARγ).

METHODS

The study aims to evaluate the effects of BCA in ovalbumin (OVA)-induced murine model of asthma and to study the role of PPARγ.

RESULTS

We found that BCA administration reduced the severity of murine allergic asthma as evidenced histologically, and measurement of allergen-specific IgE levels in serum as well as in BAL fluid. BCA also reversed the elevated levels of inflammatory cytokines, cell infiltration, protein leakage into the airways and expression of hemoxygenase-1 in OVA-induced lungs. Further, we confirmed that BCA mediated inhibitory effects are mediated through PPARγ as assessed by treatment with PPARγ antagonist GW9662.

CONCLUSION

Our results suggest that BCA is efficacious in a preclinical model of asthma and may have the potential for the treatment of asthma in humans.

Long-Acting Muscarinic Antagonists Under Investigational to Treat Chronic Obstructive Pulmonary Disease

Introduction

Bronchodilators are the cornerstone of chronic obstructive pulmonary disease (COPD) therapy and long-acting muscarinic antagonists (LAMAs) as a mono or combination treatment play a pivotal role. Several LAMAs are already available on the market in different formulations, but developing a new compound with a higher M3 receptor selectivity and a lower affinity to M2 receptors to increase the therapeutic effect and minimize the adverse effects is still a goal. Moreover, new formulations could improve adherence to therapy.

Areas Covered

This systematic review assesses investigational long-acting muscarinic antagonist in Phase I and II clinical trials over the last decade. It offers insights on whether LAMAs and/or their new formulations in clinical development can become effective treatments for COPD in the future.

Expert Opinion

Research on LAMA seems to have come to a standstill, the few new molecules under study do not show distinctive characteristics compared to the previous ones. Muscarinic antagonist/β2-agonist (MABAs) appear to be the major innovation currently under investigation, and they could theoretically open new research frontiers on the effect between adrenergic and muscarinic interaction in the same cell.

Protective effects of ascorbic acid and calcitriol combination on airway remodelling in ovalbumin-induced chronic asthma

Context: Airway remodelling is one of the most refractory problems in asthma. According to the critical roles of oxidative stress and inflammation in airway remodelling, it is supposed that ascorbic acid and calcitriol have beneficial effects. However, a combination of antioxidants may be more effective for asthma therapy.Objective: This study investigated the protective effects of ascorbic acid in combination with calcitriol on airway remodelling in ovalbumin (OVA)-induced chronic asthma.Materials and methods: BALB/c mice were assigned into seven groups: (1) Control; (2) Asthma; (3) Ineffective C (orally 39 mg/kg ascorbic acid); (4) Ineffective D (intraperitoneally 1.5 μg/kg calcitriol); (5) Effective C (orally 130 mg/kg ascorbic acid); (6) Effective D (intraperitoneally 5 μg/kg calcitriol); (7) Combination (orally 39 mg/kg ascorbic acid + intraperitoneally 1.5 μg/kg calcitriol). All animals were sensitized and challenged with OVA except in the control group (normal saline). In all treatment groups, mice were administrated vitamins 30 min before each challenge (three times per week for 8 consecutive weeks).Results: In comparison with the asthma group, co-administration of ineffective doses of ascorbic acid and calcitriol led to the decreased levels of IL-13 (50.5 ± 1.85 vs. 42.13 ± 0.37 pg/mL, p = 0.02) and IgE (58.74 ± 0.43 vs. 45.78 ± 2.05 ng/mL, p = 0.003) as well as the reduction of goblet hyperplasia and subepithelial fibrosis (5 vs. 1 score, p = 0.001 and 5 vs. 2 score, p = 0.001, respectively).Discussion and conclusions: Combination of ascorbic acid with calcitriol in ineffective doses improves airway remodelling due to additive effects possibly through reduction of oxidative stress and inflammation. This study provides a scientific basis for further research and clinical applications of ascorbic acid and calcitriol and can be generalized to the broader pharmacological studies.

TLR3 inhibitor and tyrosine kinase inhibitor attenuate cigarette smoke/poly I:C-induced airway inflammation and remodeling by the EGFR/TLR3/MAPK signaling pathway

Tobacco smoke is the major risk factor for developing chronic obstructive pulmonary disease (COPD). Viral infection is a major cause of COPD exacerbation, which lacks effective drug treatments. In the present study, to mimic the pathogenesis of COPD, we employed a TLR3 ligand [Poly (I:C), PIC] to mimic viral infection to determine whether it enhances the effects of cigarette smoke (CS)-induced airway inflammation and remodeling. Our results showed that PIC enhanced the effects of cigarette smoke extract (CSE)-induced inflammatory cytokine IL-1β, TNF-α and IL-8 mRNA expression and remodeling factor E-cadherin, α-SMA and TGF-β1 mRNA expression with TLR3 upregulation and EGFR phosphorylation in pulmonary epithelial NCI-H292 cells. These responses were inhibited by a TLR3/dsRNA complex inhibitor (TLR3i) or a tyrosine kinase inhibitor icotinib (Ico). Similarly, in the PIC-enhanced CS-induced airway inflammation and remodeling mouse model, treatment with TLR3i or Ico reduced the mRNA and protein expression of the inflammatory cytokines IL-1β and TNF-α and keratinocyte chemoattractant (KC) and the remodeling factors α-SMA, TGF-β1, MMP-9 and MUC5AC, while increasing E-cadherin mRNA and protein expression. Furthermore, we found that TLRi and Ico can attenuate the airway hyperreactivity induced by PIC, which is enhanced by CS. Finally, PIC enhanced the effects of CS on TLR3 upregulation and EGFR phosphorylation and significantly increased Erk1/2 and P38 phosphorylation, whereas TLR3i and Ico markedly suppressed TLR3 upregulation and EGFR, Erk1/2 and P38 phosphorylation in the model. Our findings suggest that TLR3/EGFR may be a potential target for the treatment of airway inflammation and remodeling in COPD.

Bencycloquidium bromide nasal spray is effective and safe for persistent allergic rhinitis: a phase III, multicenter, randomized, double-blinded, placebo-controlled clinical trial

PURPOSE

To investigate the efficacy and safety of bencycloquidium bromide nasal spray (BCQB) in patients with persistent allergic rhinitis (PAR).

METHODS

We enrolled 720 patients from 15 hospitals across China and randomly assigned them into BCQB group or placebo group (90 μg per nostril qid) to receive a 4-week treatment. Visual analog scale (VAS) for rhinorrhea, sneezing, nasal congestion, itching and overall symptoms were recorded by patients every day. Anterior rhinoscopy scoring was completed by doctors on every visit. Adverse events were recorded in detail.

RESULTS

A total of 354 and 351 patients were included in BCQB group and in placebo group. Baseline information was comparable. At the end of the trial, the decrease of VAS for rhinorrhea from baseline was 4.83 ± 2.35 and 2.46 ± 2.34 in BCQB group and placebo group, respectively (P < 0.001). The change ratio from baseline of VAS for rhinorrhea in BCQB group was 72.32%, higher than 31.03% in placebo group (P < 0.001). VAS for other symptoms and overall symptoms also improved significantly in the BCQB group, while no inter-group difference was found in anterior rhinoscopy scoring. The incidence of adverse reaction was similar between the two groups. Most reactions were mild and no severe reactions happened.

CONCLUSION

90 μg BCQB per nostril four times daily is effective and safe in the treatment of rhinorrhea as well as sneezing, nasal congestion and itching for patients with PAR.

RETROSPECTIVELY REGISTERED

ChiCTR2000030924, 2020/3/17.

Emerging muscarinic receptor antagonists for the treatment of asthma

INTRODUCTION

The increased acetylcholine signaling in asthma pathophysiology offers the rationale for the use of LAMAs in the treatment of asthmatic patients. Tiotropium is still the only LAMA approved for use in asthma but there is a real interest in developing novel LAMAs for the treatment of asthma, or at least to extend this indication to other LAMAs already on the market.

AREAS COVERED

We examined and discussed trials and research that have studied or are evaluating the role of LAMAs already on the market in asthma and possible novel muscarinic acetylcholine receptor antagonists.

EXPERT OPINION

Glycopyrronium and umeclidinium will soon be included in the GINA strategy with the same current indications of tiotropium. It is likely that the choice of the LAMA will be influenced not so much by its pharmacological profile as by the type of triple therapy chosen. It is extremely difficult to identify a new LAMA that is more effective than tiotropium, but is it plausible that new technologies that will allow delivering the drug in a more targeted way and with a lower risk of adverse effects may represent the real progress in the use of LAMAs in asthma in the coming years.

ZDHXB-101 (3',5-Diallyl-2, 4'-dihydroxy-[1,1'-biphen-yl]-3,5'-dicarbaldehyde) protects against airway remodeling and hyperresponsiveness via inhibiting both the activation of the mitogen-activated protein kinase and the signal transducer and activator of transcription-3 signaling pathways

Airway remodeling consists of the structural changes of airway walls, which is often considered the result of longstanding airway inflammation, but it may be present to an equivalent degree in the airways of children with asthma, raising the need for early and specific therapeutic interventions. The arachidonic acid cytochrome P-450 (CYP) pathway has thus far received relatively little attention in its relation to asthma. In this study, we studied the inhibition of soluble epoxide hydrolase (sEH) on airway remodeling and hyperresponsiveness (AHR) in a chronic asthmatic model which long-term exposure to antigen over a period of 12 weeks. The expression of sEH and CYP2J2, the level of 14, 15-epoxyeicosatrienoic acids (EETs), airway remodeling, hyperresponsiveness and inflammation were analyzed to determine the inhibition of sEH. The intragastric administration of 3 or 10 mg/kg ZDHXB-101, which is a structural derivative of natural product honokiol and a novel soluble epoxide hydrolase (sEH) inhibitor, daily for 9 weeks significantly increased the level of 14, 15-EETs by inhibiting the expression of sEH and increasing the expression of CYP2J2 in lung tissues. ZDHXB-101 reduced the expression of remodeling-related markers such as interleukin (IL)-13, IL-17, MMP-9 N-cadherin, α-smooth muscle actin, S100A4, Twist, goblet cell metaplasia, and collagen deposition in the lung tissue or in bronchoalveolar lavage fluid. Moreover, ZDHXB-101 alleviated AHR, which is an indicator that is used to evaluate the airway remodeling function. The inhibitory effects of ZDHXB-101 were demonstrated to be related to its direct inhibition of the extracellular signal-regulated kinase (Erk1/2) phosphorylation, as well as inhibition of c-Jun N-terminal kinases (JNK) and the signal transducer and activator of transcription-3 (STAT3) signal transduction. These findings first revealed the anti-remodeling potential of ZDHXB-101 lead in chronic airway disease.

Similarities and differences in the effects of sensitisation and challenge with Dermatophagoides farinae and Dermatophagoides pteronyssinus extracts in a murine asthma surrogate

Patients with atopic asthma may become sensitised to the grain storage mite Dermatophagoides farinae (Der f), the house dust mite Dermatophagoides pteronyssinus (Der p) or both, but thus far little attention has been paid to date to possible variation in their pathophysiological effects. Here we present a side by side comparison of the effects of extracts of these two dust mites in a murine surrogate of atopic asthma. Compared with the Der p-challenged mice, however, the mice-challenged with Der f had favour changes in lung tissue elasticity and expression in matrix metalloproteinases in lung tissue, while the mice challenged with Der p showed more neutrophils infiltrating around the airway and stronger expression of steroid-resistant related cytokines in the lung tissue. Our data suggest that different dust mite crude extracts might lead different pathological characteristics, at least in murine models of asthma.

Inhibition of soluble epoxide hydrolase attenuates airway remodeling in a chronic asthma model

Airway remodeling in asthma is difficult to treat because of its complex pathophysiology that involves proinflammatory cytokines, as well as the arachidonic acid cytochrome P-450 (CYP) pathway; however, it has received little attention. In this study, we assessed the efficacy of a soluble epoxide hydrolase (sEH) on airway remodeling in a mouse model of chronic asthma. The expression of sEH and CYP2J2 and the level of 14,15-epoxyeicosatrienoic acid (14,15-EET), airway remodeling and hyperresponsiveness (AHR) were analyzed to determine the level of sEH inhibition. AUDA, a sEH inhibitor, was given daily for 9 weeks orally, which significantly increased the level of 14,15-EET by inhibiting the expression of sEH and increasing the expression of CYP2J2 in lung tissues. The inhibition of sEH reduced the expression of remodeling-related molecular markers, such as interleukin (IL)-13, IL-17, matrix metalloproteinase 9, N-cadherin, α-smooth muscle actin (α-SMA), S100A4, Twist, epithelial goblet cell metaplasia, and collagen deposition in bronchoalveolar lavage fluid (BAL fluid) and lung tissues. Moreover, remodeling-related eosinophil accumulation in the BAL fluid and infiltration into the lung tissue were improved by AUDA. Finally, AUDA alleviated AHR, which is a functional indicator of airway remodeling. The effect of AUDA on airway remodeling was related to the downregulation of extracellular-regulated protein kinases (Erk1/2), c-Jun N-terminal kinases (JNK) and signal transducer and activator of transcription 3 (STAT3). To our knowledge, this is the first report to demonstrate that inhibition of sEH exerts significant protective effects on airway remodeling in asthma.

Chinese Birch Pollen Allergy and Immunotherapy in Mice

Birch pollen allergy is a common cause of spring pollinosis in China. However, there is little research on birch pollen allergen in China and only the major allergen (Bet v 1) has been fully characterized. Chinese birch pollen-induced airway inflammation models in BALB/c mice were developed and administered subcutaneous immunotherapy (SCIT). BALB/c mice were sensitized subcutaneously on days 1, 8, and 15 with 25 μg/μL birch pollen extract. On days 24-26, the mice were challenged with 0.1% birch pollen aerosol. To investigate the efficacy of SCIT, mice were subcutaneously injected 0.3 mg birch pollen extract (BPE) with or without being adsorbed to alum. Airway hyper-responsiveness (AHR) to methacholine and immunological parameters was detected. Western blot analysis was applied with mice serum and mass spectrometry was used to identify the IgE-binding bands in birch pollen. Compared with PBS group, birch pollen sensitization and challenge BALB/c mice developed AHR, and IL4, IL5, IL6, IL10, and IL17 were significantly higher. Mice sensitized by birch pollen showed increased plasma levels of anti-BPE IgE, IgG1, and IgG2a. Histologic analyses showed that mice had peribranchial infiltration of inflammatory cells and mucosal hyperplasia. After SCIT, allergic symptoms effectively alleviated and kept for a long time. Interestingly, mice serum pool showed strong reactions to 70-kDa proteins. Mass spectrometry data suggests that the 70-kDa protein belongs to the HSP 70 family. SCIT inhibited the inflammatory response in the long term and a 70-kDa protein potentially belonging to the HSP 70 family plays a significant role in Chinese birch pollen-induced mice model.

Combination of ascorbic acid and calcitriol attenuates chronic asthma disease by reductions in oxidative stress and inflammation

Airway inflammation and oxidative stress are the two major characteristics of asthma pathogenesis. Therefore, this study evaluated the protective effects of ascorbic acid in combination with calcitriol on the oxidative damages and inflammation in asthma model. All animals, except in the control group, were sensitized and challenged with ovalbumin. One day after the last challenge, samples of bronchoalveolar lavage fluid was collected for the assessment of total white blood cell counts and differential count of white blood cell and plasma was used for the measurement of pro-oxidant/antioxidant balance level. Lung tissue samples were also stored for examining peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and measurement of malondialdehyde level. Induction of asthma caused significant increases in total white blood cell counts, percentage of neutrophils and eosinophils and a decrease in the percentage of lymphocytes. Moreover, asthma resulted in significant increases of peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and malondialdehyde level. However, no significant changes were observed in pro-oxidant/antioxidant balance level with the induction of asthma. Co-administration of low doses of ascorbic acid and calcitriol returned all to the levels measured before sensitization and challenge. Combination of low doses of ascorbic acid with calcitriol improves mouse asthma model by a possible additive effects through the decrease of oxidative stress and inflammation.

Anti-allergic activities of 5,7-dimethoxy-3,4'-dihydroxyflavone via inhalation in rat allergic models

Various studies have shown that flavones have several pharmacological activities including anti-allergy activities. However, the bioavailability of oral flavones is very low, and whether inhaled administration can improve efficacy in respiratory disease models is unclear. In the present study, the anti-allergic activities of inhaling 5,7-dimethoxy-3,4'-dihydroxyflavone (MHF), a synthetic flavonoid, was investigated by comparison with disodium cromoglycate (DSCG) and nedocromil sodium (NS) in rat allergic models. In an anti-DNP-IgE-induced asthmatic model, inhaled MHF dose-dependently inhibited the increase in airway resistance after antigen challenge. In an ovalbumin (OVA)-induced asthmatic model, inhaled MHF showed significant suppression of airway hyperresponsiveness; a decrease in eosinophil and neutrophil counts, IL-4, IL-5 and leukotriene D₄ in bronchoalveolar lavage fluid; a reduction in total IgE and OVA-specific IgE levels in serum; and suppression of eosinophil infiltration in lung tissue after antigen challenge. The efficacy of inhaled MHF was comparable to that of NS and DSCG. In conclusion, based on these findings, the report for the first time that that inhaled MHF may be a potential drug for the treatment of allergic asthma.

Salvianolic acid B improves airway hyperresponsiveness by inhibiting MUC5AC overproduction associated with Erk1/2/P38 signaling

Salvianolic acid B (SalB) is one of the main water-soluble composites from Chinese medicine Dansen (Radix miltiorrhiza). It is used for clinical treatment of various diseases including cardiovascular, lung, Liver, renal and cancers. However, the effects of SalB to allergy induced airway mucin hypersecretion, inflammation and hyperresponsiveness (AHR) remains not clear. Overproduction of airway MUC5AC is a central effector of inflammation that is strongly associated with AHR in asthmatic attack. In this study, we investigated the anti-asthmatic activity and mechanism of SalB in a murine model and human epithelial cells by monitoring changes in mucin expression and secretion, airway inflammation, AHR, and signaling pathways. SalB was administered by intragastric administration (i.g) daily for a week, starting at 21 days after sensitization of ovalbumin (OVA). All examinations were performed 24h after the last antigen challenge. We found that treatments with SalB significantly inhibited increase in the tracheobronchial secretion, glycosaminoglycan levels, interleukin (IL)-13, IL-4, and IL-5 cytokines mRNA and protein expression, and decrease in mucociliary clearance in lung tissues. Histological results demonstrated that SalB attenuated OVA-induced eosinophil infiltration, airway goblet cell hyperplasia, and MUC5AC and MUC5B mRNA and protein expression in lung tissues. SalB exhibited protective effects against AHR in OVA-challenged animals. In vitro, SalB significantly inhibited IL-13-induced MUC5AC and MUC5B mRNA and protein expression in human epithelial cells. These effects were blocked by SalB by downregulating the Erk1/2 and P38 signaling pathways. Taken together, these data indicate that treatment with SalB may improve AHR by inhibiting MUC5AC overproduction.

Cholinergic Modulation of Type 2 Immune Responses

In recent years, the bidirectional relationship between the nervous and immune system has become increasingly clear, and its role in both homeostasis and inflammation has been well documented over the years. Since the introduction of the cholinergic anti-inflammatory pathway, there has been an increased interest in parasympathetic regulation of both innate and adaptive immune responses, including T helper 2 responses. Increasing evidence has been emerging suggesting a role for the parasympathetic nervous system in the pathophysiology of allergic diseases, including allergic rhinitis, asthma, food allergy, and atopic dermatitis. In this review, we will highlight the role of cholinergic modulation by both nicotinic and muscarinic receptors in several key aspects of the allergic inflammatory response, including barrier function, innate and adaptive immune responses, and effector cells responses. A better understanding of these cholinergic processes mediating key aspects of type 2 immune disorders might lead to novel therapeutic approaches to treat allergic diseases.

Acetylcholine polarizes dendritic cells toward a Th2-promoting profile

BACKGROUND

A growing body of research shows a reciprocal regulation between the neural and immune systems. Acetylcholine (ACh) is the most important parasympathetic neurotransmitter, and increasing evidence indicates that it is able to modulate the immune response. Interestingly, in recent years, it has become clear that immune cells express a non-neuronal cholinergic system, which is stimulated in the course of inflammatory processes. We have previously shown that dendritic cells (DC) express muscarinic receptors, as well as the enzymes responsible for the synthesis and degradation of ACh. Here, we analyzed whether ACh could also modulate the functional profile of DC.

METHODS

Dendritic cells were obtained from monocytes cultured for 5 days with GM-CSF+IL-4 or isolated from peripheral blood (CD1c+ DC). The phenotype of DC was evaluated by flow cytometry, the production of cytokines was analyzed by ELISA or intracellular staining and flow cytometry, and the expression of muscarinic and nicotinic receptors was evaluated by flow cytometry or qRT-PCR.

RESULTS

Treatment of DC with ACh stimulated the expression of the Th2-promoter OX40L, the production of the Th2-chemokines MDC (macrophage-derived chemokine/CCL22) and TARC (thymus and activation-regulated chemokine/CCL17), and the synthesis of IL-4, IL-5, and IL-13 by T cells, in the course of the mixed lymphocyte reaction (MLR). Moreover, we found that the stimulation of OX40L, HLA-DR, and CD83 expressions in DC induced by the Th2-promoting cytokine TSLP, as well as the production of IL-13, IL-4, and IL-5 by T cells in the course of the MLR, was further enhanced when DC were treated with TSLP plus ACh, instead of TSLP or ACh alone.

CONCLUSIONS

Our observations suggest that ACh polarizes DC toward a Th2-promoting profile.

Increase of Frequency and Modulation of Phenotype of Regulatory T Cells by Atorvastatin Is Associated with Decreased Lung Inflammatory Cell Infiltration in a Murine Model of Acute Allergic Asthma

Regulatory T cells (Tregs) play an important role by controlling allergic inflammation of airways. Recently, it has been shown that statins have immunomodulatory properties, probably mediated by their effects on Tregs. Therefore, we evaluated the in vivo effect of atorvastatin (ATV) on Tregs and its association with the inflammatory process in a model of allergic asthma. BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with intranasal OVA. ATV (40 mg/kg) was delivered by daily intraperitoneal injection for 7 or 15 days before each OVA challenge. ATV treatment for 7 days increased the frequency of Tregs in mediastinal lymph nodes (MLN) and the interleukin (IL)-10 in lungs. After 15 days of treatment, ATV increased the percentage of glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR+) and programmed cell death protein 1 (PD-1+) Tregs in the lung, without enhancing their suppressive activity, but also increased the percentage of conventional T cells expressing GITR+, PD1+, and OX-40 (tumor necrosis factor receptor superfamily member 4). Although no significant changes were observed in the number of inflammatory cells in the bronchoalveolar lavage (BAL), OVA-specific immunoglobulin E in the serum, and type 2 helper (Th2) cytokines in the lungs, there was a significant decrease of peribronchial inflammation that negatively correlated with the Tregs in MLN and the concentration of IL-10 in the lung. These results suggest that ATV has an immunomodulatory role possibly mediated by their effects on Tregs, which could contribute to the control of inflammation during allergic asthma. Further studies are necessary to elucidate the contribution of Treg to immunomodulatory action of statins in the context of allergic asthma.

Inundation of asthma target research: Untangling asthma riddles

Asthma is an inveterate inflammatory disorder, delineated by the airway inflammation, bronchial hyperresponsiveness (BHR) and airway wall remodeling. Although, asthma is a vague term, and is recognized as heterogenous entity encompassing different phenotypes. Targeting single mediator or receptor did not prove much clinical significant, as asthma is complex disease involving myriad inflammatory mediators. Asthma may probably involve a large number of different types of molecular and cellular components interacting through complex pathophysiological pathways. This review covers the past, present, and future therapeutic approaches and pathophysiological mechanisms of asthma. Furthermore, review describe importance of targeting several mediators/modulators and receptor antagonists involved in the physiopathology of asthma. Novel targets for asthma research include Galectins, Immunological targets, K ⁺ Channels, Kinases and Transcription Factors, Toll-like receptors, Selectins and Transient receptor potential channels. But recent developments in asthma research are very promising, these include Bitter taste receptors (TAS2R) abated airway obstruction in mouse model of asthma and Calcium-sensing receptor obliterate inflammation and in bronchial hyperresponsiveness allergic asthma. All these progresses in asthma targets, and asthma phenotypes exploration are auspicious in untangling of asthma riddles.

Type 3 muscarinic receptors contribute to intestinal mucosal homeostasis and clearance of Nippostrongylus brasiliensis through induction of TH2 cytokines

Despite increased appreciation for the role of nicotinic receptors in the modulation of and response to inflammation, the contribution of muscarinic receptors to mucosal homeostasis, clearance of enteric pathogens, and modulation of immune cell function remains relatively undefined. Uninfected and Nippostrongylus brasiliensis-infected wild-type and type 3 muscarinic receptor (M3R)-deficient (Chrm3(-/-)) mice were studied to determine the contribution of M3R to mucosal homeostasis as well as host defense against the TH2-eliciting enteric nematode N. brasiliensis Intestinal permeability and expression of TH1/TH17 cytokines were increased in uninfected Chrm3(-/-) small intestine. Notably, in Chrm3(-/-) mice infected with N. brasiliensis, small intestinal upregulation of TH2 cytokines was attenuated and nematode clearance was delayed. In Chrm3(-/-) mice, TH2-dependent changes in small intestinal function including smooth muscle hypercontractility, increased epithelial permeability, decreased epithelial secretion and absorption, and goblet cell expansion were absent despite N. brasiliensis infection. These findings identify an important role for M3R in host defense and clearance of N. brasiliensis, and support the expanding role of cholinergic muscarinic receptors in maintaining mucosal homeostasis.

Evaluation of Simvastatin and Bone Marrow-Derived Mesenchymal Stem Cell Combination Therapy on Airway Remodeling in a Mouse Asthma Model

INTRODUCTION

The effect of bone marrow-derived mesenchymal stem cells (BMSCs) on asthma treatment was shown in our previous study. Several studies have shown the effect of statins on BMSC preservation and migration to sites of inflammation. In this study, the effects of simvastatin and BMSC combination therapy in an ovalbumin-induced asthma model in mouse were examined.

METHODS

Four groups of BALB/c mice were studied including control group (animals were not sensitized), asthma group (animals were sensitized by ovalbumin), asthma + simvastatin group (asthmatic animals were treated with simvastatin), and asthma + BMSC + simvastatin group (asthmatic animals were treated with simvastatin and BMSCs). BMSCs were isolated, characterized, labeled with BrdU, and transferred into asthmatic mice. BMSC migration, airways histopathology, and total and differential white blood cell (WBC) count in bronchoalveolar lavage (BAL) fluid were evaluated.

RESULTS

A significant increase in the number of BrdU-BMSCs was found in the lungs of mice treated with simvastatin + BMSCs compared to mice treated with BMSCs. The histopathological changes, BAL total WBC counts, and the percentage of neutrophils and eosinophils were increased in asthma group compared to the control group. Treatment with simvastatin significantly decreased airway inflammation and inflammatory cell infiltration. Combination therapy improved all measured parameters higher than simvastatin. Goblet cell hyperplasia and subepithelial fibrosis were also decreased in combination therapy group.

CONCLUSION

These results indicated that simvastatin and BMSC combination therapy was superior to simvastatin therapy and BMSC therapy alone in reduction of airway remodeling and lung inflammation in the ovalbumin-induced asthma model in mouse.

Airway and lung remodelling in chronic pulmonary obstructive disease: a role for muscarinic receptor antagonists?

Lung tissue remodelling in chronic inflammatory lung diseases has long been regarded as a follow-up event to inflammation. Recent studies have indicated that, although airway and lung tissue remodelling is often independent of inflammation, it precedes or causes inflammation. None of the available therapies has a significant effect on airway and lung tissue remodelling in asthma, bronchiectasis, fibrosis and chronic obstructive pulmonary disease (COPD). The goal of stopping or reversing lung tissue remodelling is difficult, as the term summarizes the net effect of independent events, including (1) cell proliferation, (2) cell volume increase, (3) cell migration, (4) modified deposition and metabolism of specific extracellular matrix components, and (5) local action of infiltrated inflammatory cells. The extracellular matrix of the lung has a very high turnover, and thus small changes may accumulate to significant structural pathologies, which seem to be irreversible. The most important question is 'why are pathological changes of the lung structure irreversible and resistant to drugs?' Many drugs have the potential to reduce remodelling mechanisms in vitro but fail in clinical trials. New evidence suggests that muscarinic receptor inhibitors have the potential to improve lung function through modifying tissue remodelling. However, the role of muscarinic receptors in lung remodelling, especially their supportive role for other remodelling driving factors, needs to be further investigated. The focus of this review is the role of muscarinic receptors in lung tissue remodelling as it has been reported in the human lung.

Type 3 Muscarinic Receptors Contribute to Clearance of Citrobacter rodentium

BACKGROUND

The role of muscarinic receptors in mucosal homeostasis, response to enteric pathogens, and modulation of immune cell function is undefined.

METHODS

The contribution of type 3 muscarinic receptors (M3R) to mucosal homeostasis within the colon and host defense against Citrobacter rodentium was determined in uninfected and C. rodentium-infected WT and M3R-deficient (Chrm3) mice. In addition, WT and Chrm3 bone marrow-derived macrophages were studied to determine the ability of M3R to modulate macrophage phenotype and function.

RESULTS

In Chrm3 mice, clearance of C. rodentium was delayed despite an amplified TH1/TH17 response. Delayed clearance of C. rodentium from Chrm3 mice was associated with prolonged adherence of bacteria to colonic mucosa, decreased goblet cell number, and decreased mucin 2 gene expression. Treatment of bone marrow-derived macrophages with bethanechol, a muscarinic-selective agonist, induced a classically activated macrophage phenotype, which was dependent on M3R expression. Chrm3 bone marrow-derived macrophages retained their ability to attain a classically activated macrophage phenotype when treated with the TH1 cytokine IFN-γ.

CONCLUSIONS

In Chrm3 mice, mucin production is attenuated and is associated with prolonged adherence of C. rodentium to colonic mucosa. The immune response, as characterized by production of TH1/TH17 cytokines, in C. rodentium-infected Chrm3 mice is intact. In addition, M3R activity promotes the development of classically activated macrophages. Our data establish a role for M3R in host defense against C. rodentium through effects on goblet cell mucus production and in the modulation of macrophage phenotype and function.

Effects of the inhalation of the m3 receptor antagonist bencycloquidium bromide in a mouse cigarette smoke-induced airway inflammation model

Bencycloquidium bromide (BCQB), a novel M3 receptor antagonist, alleviates airway hyperresponsiveness, inflammation, and airway remodeling in a murine model of asthma. The aim of this study was to investigate the anti-inflammatory activity of inhaled BCQB in a cigarette smoke (CS)-induced model of acute lung inflammation. Mice exposed to CS developed chronic obstructive pulmonary disease (COPD). Inhalation of BCQB suppressed the accumulation of neutrophils and macrophages in airways and lung and also inhibited the CS-induced increases in mRNA levels of keratinocyte-derived chemokine, monocyte chemotactic protein-1, tumor necrosis factor-alpha, and interleukin-1β in lung and protein expression levels in bronchoalveolar lavage fluid. Moreover, BCQB (300 μg/ml) inhibited the CS-induced changes in superoxide dismutase and myeloperoxidase activities in the lungs. Our study suggests that BCQB might be a potential therapy for inflammation in CS-induced pulmonary diseases, including COPD.

Study of pharmacokinetic interaction of paroxetine and roxithromycin on bencycloquidium bromide in healthy subjects

PURPOSE

The aim of this study was to investigate the potential drug-drug interaction between Bencycloquidium bromide (BCQB) and paroxetine, and between BCQB and roxithromycin.

METHODS

Two studies were conducted on healthy male Chinese volunteers. Study A was an open-label, two-period, one-sequence crossover study (n=21). Each participant received a single nasal spray dose of BCQB 180μg on day 1. After a 7-day wash-out period, subjects received 20mg of paroxetine from day 8 to 17, and were co-administered 20mg of paroxetine and BCQB 180μg on day 18. In study B, participants (n=12) were randomly assigned to two groups. In period I, group A received BCQB 180μg on day 1, followed by the same dose four times daily from day 4 to 10, then, on day 11 a single dose of 150mg roxithromycin with BCQB 180μg were co-administered. In parallel, group B received a single dose of roxithromycin 150mg on day 1, followed by 300mg of roxithromycin from day 4 to 10, then, on day 11 a single dose of BCQB 180μg with roxithromycin 300mg were co-administered. After a wash-out time of 7days the respective treatments of each group (A and B) were swapped in period II. Blood samples were collected for pharmacokinetic analysis. Statistical comparison of pharmacokinetic parameters was performed to identify a possible drug interaction between treatments. Tolerability was evaluated by recording adverse events.

RESULTS

Study A: Geometric mean AUC0-36 for BCQB alone and co-administered with paroxetine were 474.3 and 631.3pgh/ml, respectively. The geometric mean ratio (GMR) of AUC0-36 was 1.33 (1.13-1.46), 90% C.Is, and was out the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Geometric mean Cmax were 187.0 and 181.2pg/ml. Study B: The GMR of AUC0-36 was 0.98 (0.90-1.07), 90% C.Is for BCQB, and the GMR of AUC0-72 was 0.98 (0.87-1.11), 90% C.Is for roxithromycin. Both GMRs were within the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Other pharmacokinetic parameters were within the predefined interval. No serious adverse events were reported and no significant clinical changes were observed in laboratory test results, vital signs and ECGs in any of the studies. All treatments were well tolerated.

CONCLUSION

The co-administration of BCQB with paroxetine showed a moderate increase in BCQB exposure, but was not clinically relevant. Also, no drug interaction was found between BCQB and roxithromycin.

CHRM2 but not CHRM1 or CHRM3 polymorphisms are associated with asthma susceptibility in Mexican patients

Asthma is a complex disease for which genetic predisposition has been widely documented. Considerable evidence supports the hypothesis that polymorphisms in the muscarinic-cholinergic (CHRM) genes could be involved in asthma pathogenesis, bronchial hyperresponsiveness, and mucus secretion. To determine whether single nucleotide polymorphisms (SNPs) or haplotypes in CHRM1, CHRM2, or CHRM3 are associated with asthma in Mexican pediatric population. We performed a case-control study including 398 pediatric cases with asthma and 450 healthy controls. We analyzed 19 SNPs distributed among these three genes. Two of the seven SNPs located in CHRM2, the 3' untranslated region rs8191992 and rs6962027, differed significantly in allele frequencies between patients with asthma and healthy controls [odds ratio (OR) 1.42, 95 % confidence interval (95 % CI) 1.14-1.77, P = 0.001, and OR 1.50, 95 % CI 1.21-1.87, P = 0.0002, respectively]. Statistical significance remained after multiple comparison corrections (P = 0.003 and P = 0.005, respectively). The haplotypes AA and TT, containing both major and minor alleles from rs8191992 and rs6962027, also differed between cases and controls. The haplotype AA occurred at a lower frequency in cases (OR 0.67, 95 % CI 0.53-0.85, P = 0.001) whereas the haplotype TT was overrepresented in cases compared to controls (28 vs 21 %, respectively; OR 1.46, 95 % CI 1.15-1.85, P = 0.002). No association was observed between CHRM1 or CHRM3 SNPs or haplotypes and asthma. CHRM2 polymorphisms are implicated in the genetic etiology of asthma.

A new perspective on muscarinic receptor antagonism in obstructive airways diseases

Acetylcholine has traditionally only been regarded as a neurotransmitter of the parasympathetic nervous system, causing bronchoconstriction and mucus secretion in asthma and COPD by muscarinic receptor activation on airway smooth muscle and mucus-producing cells. Recent studies in experimental models indicate that muscarinic receptor stimulation in the airways also induces pro-inflammatory, pro-proliferative and pro-fibrotic effects, which may involve activation of airway structural and inflammatory cells by neuronal as well as non-neuronal acetylcholine. In addition, mechanical changes caused by muscarinic agonist-induced bronchoconstriction may be involved in airway remodeling. Crosstalk between muscarinic receptors and β2-adrenoceptors on airway smooth muscle causes a reduced bronchodilator response to β2-agonists, and a similar mechanism could possibly apply to the poor inhibition of inflammatory and remodeling processes by these drugs. Collectively, these findings provide novel perspectives for muscarinic receptor antagonists in asthma and COPD, since these drugs may not only acutely affect cholinergic airways obstruction, but also have important beneficial effects on β2-agonist responsiveness, airway inflammation and remodeling. The clinical relevance of these findings is presently under investigation and starting to emerge.

Muscarinic receptors and their antagonists in COPD: anti-inflammatory and antiremodeling effects

Muscarinic receptors are expressed by most cell types and mediate cellular signaling of their natural ligand acetylcholine. Thereby, they control numerous central and peripheral physiological organ responses to neuronal activity. In the human lung, muscarinic receptors are predominantly expressed by smooth muscle cells, epithelial cells, and fibroblasts. Antimuscarinic agents are used for the treatment of chronic obstructive pulmonary disease and to a lesser extent for asthma. They are primarily used as bronchodilators, but it is now accepted that they are also associated with anti-inflammatory, antiproliferative, and antiremodeling effects. Remodeling of the small airways is a major pathology in COPD and impairs lung function through changes of the extracellular matrix. Glycosaminoglycans, particularly hyaluronic acid, and matrix metalloproteases are among extracellular matrix molecules that have been associated with tissue inflammation and remodeling in lung diseases, including chronic obstructive pulmonary disease and asthma. Since muscarinic receptors have been shown to influence the homeostasis of glycosaminoglycans and matrix metalloproteases, these molecules may be proved valuable endpoint targets in clinical studies for the pharmacological exploitation of the anti-inflammatory and antiremodeling effects of muscarinic inhibitors in the treatment of chronic obstructive pulmonary disease and asthma.

Muscarinic receptors on airway mesenchymal cells: novel findings for an ancient target

Since ancient times, anticholinergics have been used as a bronchodilator therapy for obstructive lung diseases. Targets of these drugs are G-protein-coupled muscarinic M(1), M(2) and M(3) receptors in the airways, which have long been recognized to regulate vagally-induced airway smooth muscle contraction and mucus secretion. However, recent studies have revealed that acetylcholine also exerts pro-inflammatory, pro-proliferative and pro-fibrotic actions in the airways, which may involve muscarinic receptor stimulation on mesenchymal, epithelial and inflammatory cells. Moreover, acetylcholine in the airways may not only be derived from vagal nerves, but also from non-neuronal cells, including epithelial and inflammatory cells. Airway smooth muscle cells seem to play a major role in the effects of acetylcholine on airway function. It has become apparent that these cells are multipotent cells that may reversibly adopt (hyper)contractile, proliferative and synthetic phenotypes, which are all under control of muscarinic receptors and differentially involved in bronchoconstriction, airway remodeling and inflammation. Cholinergic contractile tone is increased by airway inflammation associated with asthma and COPD, resulting from exaggerated acetylcholine release as well as increased expression of contraction related proteins in airway smooth muscle. Moreover, muscarinic receptor stimulation promotes proliferation of airway smooth muscle cells as well as fibroblasts, and regulates cytokine, chemokine and extracellular matrix production by these cells, which may contribute to airway smooth muscle growth, airway fibrosis and inflammation. In line, animal models of chronic allergic asthma and COPD have recently demonstrated that tiotropium may potently inhibit airway inflammation and remodeling. These observations indicate that muscarinic receptors have a much larger role in the pathophysiology of obstructive airway diseases than previously thought, which may have important therapeutic implications.

Pharmacokinetics, safety and tolerability of Bencycloquidium bromide, a novel selective muscarinic M1/M3 receptor antagonist, after single and multiple intranasal doses in healthy chinese subjects: an open-label, single-center, first-in-human study

Background: Bencycloquidium bromide (BCQB) is a novel, potent and selective muscarinic M1/M3 receptor antagonist under development for the treatment of rhinorrhea in rhinitis. The pharmacokinetics and safety of BCQB in animals have been established in preclinical studies. However, no clinical pharmacokinetic data are available for BCQB in humans.

Objective: The aim of this first-in-human study was to evaluate the pharmacokinetics, safety and tolerability of BCQB following single and multiple intranasal doses in healthy Chinese subjects.

Methods: The clinical trial was comprised of the following four studies: (i) an open-label, single-dose escalation study to evaluate the safety and tolerability in healthy subjects after intranasal doses of BCQB ranging from 45 to 450 mg (total of six doses); (ii) an open-label, multiple-dose escalation study to assess the safety and tolerability in healthy subjects after intranasal administration with 120 and 150 mg doses of BCQB (360 and 450 μg/day) administered three times daily for 15 days; (iii) a randomized, open-label and parallel-group design to evaluate the single-dose pharmacokinetics of BCQB after intranasal dosing (45, 90, and 180 μg); and (iv) ten subjects received 120 μg of BCQB by intranasal administration, three times daily for 5 days with a final single dose on day 7 to assess its multiple-dose pharmacokinetics. Safety and tolerability of BCQB were evaluated by monitoring adverse events (AEs), ECG recordings, vital signs and clinical laboratory parameters. The pharmacokinetic parameters for BCQB were calculated by software using noncompartmental methods.

Results: All AEs were mild, of limited duration and no more frequent at higher doses. There was no serious adverse event, death or withdrawal. No clinically significant change was noted in clinical laboratory parameters, cardiac parameters or vital signs. Following single intranasal dosing, BCQB was rapidly absorbed with a median time to maximum concentration (t_max) of 8 minutes for 45, 90, and 180 mg dose groups; the plasma concentration of BCQB decreased in a biphasic manner with the mean half-life (t_1/2) of 8.5 hours; the maximum concentration (C_max) and area under the plasma concentration-time curve (AUC) of BCQB increased linearly across the examined dose range of 45–180 μg. During the multiple dosing, the steady state was achieved within 3 days of 120 μg three times daily dosing of BCQB. A slightly greater AUC was observed after 5 days of multiple dosing, with the mean accumulation ratio of 1.26; however, the half-life was unchanged.

Conclusion: BCQB was safe and well tolerated in healthy Chinese subjects when administered intranasally with single and multiple doses across the doses studied. The mean C_max and AUC increased proportionally to the studied doses, and the steady state was achieved within 3 days after three times daily dosing. A slight accumulation of BCQB following multiple dosing was observed. The pharmacokinetics, safety and tolerability profiles of BCQB pose it as a good candidate for further development in the treatment of rhinorrhea in rhinitis.

Role of parasympathetic nerves and muscarinic receptors in allergy and asthma

Parasympathetic nerves control the symptoms and inflammation of allergic diseases primarily by signaling through peripheral muscarinic receptors. Parasympathetic signaling targets classic effector tissues such as airway smooth muscle and secretory glands and mediates acute symptoms of allergic disease such as airway narrowing and increased mucus secretion. In addition, parasympathetic signaling modulates inflammatory cells and non-neuronal resident cell types such as fibroblasts and smooth muscle contributing to chronic allergic inflammation and tissue remodeling. Importantly, muscarinic antagonists are experiencing a rebirth for the treatment of asthma and may be useful for treating other allergic diseases.

Regulation of airway inflammation and remodeling by muscarinic receptors: perspectives on anticholinergic therapy in asthma and COPD

Acetylcholine is the primary parasympathetic neurotransmitter in the airways and an autocrine/paracrine secreted hormone from non-neuronal origins including inflammatory cells and airway structural cells. In addition to the well-known functions of acetylcholine in regulating bronchoconstriction and mucus secretion, it is increasingly evident that acetylcholine regulates inflammatory cell chemotaxis and activation, and also participates in signaling events leading to chronic airway wall remodeling that is associated with chronic obstructive airway diseases including asthma and COPD. As muscarinic receptors appear responsible for most of the pro-inflammatory and remodeling effects of acetylcholine, these findings have significant implications for anticholinergic therapy in asthma and COPD, which is selective for muscarinic receptors. Here, the regulatory role of acetylcholine in inflammation and remodeling in asthma and COPD will be discussed including the perspectives that these findings offer for anticholinergic therapy in these diseases.

Simvastatin delivery via inhalation attenuates airway inflammation in a murine model of asthma

The dose-response of the pleiotropic effects of statins on airway inflammation has not yet been established and may differ from that of their cholesterol-lowering effects. High oral doses of statins may have adverse effects, and it may be possible to overcome the side effects and low clinical efficacy by administering statins via inhalation. In this study, we hypothesize that simvastatin is a potential anti-inflammatory drug with biological and pharmacokinetic properties suitable for delivery by the inhaled route. Mice were immunized with ovalbumin (OVA) and then challenged with aerosol OVA. Simvastatin was locally delivered by inhalation (i.h.) and intratracheal injection (i.t.) or systematically delivered by intraperitoneal injection (i.p.) and gavage (i.g.) during the OVA challenge. In a mouse model of asthma, i.h. simvastatin significantly and dose-dependently attenuated airway inflammation, remodeling and hyperresponsiveness in a RhoA-dependent pathway. Upon comparing the pharmacodynamics, i.h. simvastatin had a more potent effect than that of i.g. and i.p. simvastatin, and the i.h. or i.t. delivery routes led to a higher drug concentration in local lung tissue and a lower drug concentration in the plasma than that obtained by the i.g. These results suggest that simvastatin is a potential anti-inflammatory drug for airway inflammatory diseases with properties suitable for delivery by inhalation, which will probably reduce the side effects and increase clinical efficacy.

Oral administration of allergen extracts from mugwort pollen desensitizes specific allergen-induced allergy in mice

Clinically, sublingual immunotherapy (SLIT) using allergen extracts effectively alleviates the symptoms of allergic rhinitis and asthma. We hypothesized that oral administration of a high-dose of allergen extracts imitates SLIT, which may prevent IgE-related responses in allergic diseases. In the present study, we investigated the effects of oral administration of allergen extracts from mugwort pollen (MP) on allergen-induced inflammation and airway hyperresponsiveness (AHR) in an allergic mouse model. After administration of MPdrop containing Art v 1 and Art v 4 extracts derived from MP specifically in MP-sensitized mice, the effects of MPdrop on AHR, inflammatory cell accumulation, cytokine production in the bronchoalveolar lavage fluid and lung tissue, and serum IgE and IgG levels were investigated. The results indicated that MPdrop not only prevented the AHR in response to methacholine in a dose-dependent manner but also significantly reduced the total serum and allergen-specific IgE levels. All of the maximal effects were achieved at a dose of 100μg/(kgd) and were comparable to the effects of dexamethasone at a dose of 0.5mg/(kgd). Furthermore, oral administration of MPdrop dose-dependently elevated allergen-specific serum IgG2a levels, reduced total and allergen-specific IgE levels and normalized the imbalance between the Th1 cytokine IL-12 and Th2 cytokines IL-4 and IL-5. Finally, oral administration of MPdrop significantly reduced goblet cell hyperplasia and eosinophilia in the MP-sensitized allergic mouse model. These data suggest that MPdrop effectively improves specific allergen-induced inflammation and AHR in MP-sensitized and -challenged mice and provides the rationale for clinical use of MPdrop in the specific allergen-induced asthma.