Acute Asthma Model Research Articles

Targeting Acidic Mammalian chitinase Is Effective in Animal Model of Asthma.

This article highlights our work toward the identification of a potent, selective, and efficacious acidic mammalian chitinase (AMCase) inhibitor. Rational design, guided by X-ray analysis of several inhibitors bound to human chitotriosidase (hCHIT1), led to the identification of compound 7f as a highly potent AMCase inhibitor (IC50 values of 14 and 19 nM against human and mouse enzyme, respectively) and selective (>150× against mCHIT1) with very good PK properties. This compound dosed once daily at 30 mg/kg po showed significant anti-inflammatory efficacy in HDM-induced allergic airway inflammation in mice, reducing inflammatory cell influx in the BALF and total IgE concentration in plasma, which correlated with decrease of chitinolytic activity. Therapeutic efficacy of compound 7f in the clinically relevant aeroallergen-induced acute asthma model in mice provides a rationale for developing AMCase inhibitor for the treatment of asthma.

COMPARATIVE STUDY OF ACUTE AND CHRONIC MURINE ASTHMA MODEL IN THE PATHOGENESIS OF ASTHMA

RespirologyVolume 22, Issue S3 p. 89-89 APSR Poster Abstracts COMPARATIVE STUDY OF ACUTE AND CHRONIC MURINE ASTHMA MODEL IN THE PATHOGENESIS OF ASTHMA First published: 20 November 2017 https://doi.org/10.1111/resp.13207_6Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume22, IssueS3Supplement: 22nd Congress of the Asian Pacific Society of Respirology, International Convention Centre, Sydney, Australia, 23–26 November 2017November 2017Pages 89-89 RelatedInformation

Fine particulate matter aggravates allergic airway inflammation through thymic stromal lymphopoietin activation in mice.

Fine particulate matter (PM2.5) has been linked to exacerbation of allergic airway inflammation in mice. However, the mechanism underlying exposure to PM2.5 and subsequent and adverse effects remains to be fully elucidated. Therefore, the present study aimed to investigate the effects of PM2.5 by different levels on airway inflammation in mouse models of in allergic and steroid‑resistant asthma. BALB/c mice were nasally instilled with PBS (control) or 10, 31.6 or 100µg PM2.5, and randomly assigned into nine groups. The acute asthma model was previously induced to investigate the change of inflammatory cells in bronchoalveolar lavage fluid (BALF). Histopathological changes of the lung were assessed, in addition to levels of interleukin (IL)‑4 and IL‑13 in BALF and immunoglobulin Ein serum. Thymic stromal lymphopoietin (TSLP) proteinexpression levels were assessed by western blotting. The present study demonstrated that medium‑ and high‑dose PM2.5 is linked to acute exacerbation of allergic airway inflammation in mice. In conclusion, the pathological mechanisms of PM2.5 may be associated with allergic/steroid‑resistant airway inflammation, T‑cell helper (Th)1/Th2 cytokine production and upregulation of TSLP expression in a murine model of allergic and steroid-resistant asthma.

Therapeutic effects of Tubastatin A Hcl on airway inflammation in acute mice asthma model

Objective: To investigated the therapeutic effects of Tubastatin A Hcl, a selective HDAC6 inhibitor, on airway inflammation in acute mice bronchial asthma (asthma) model. Methods: A total of 48 BALB/C mice were randomly divided into control group, asthma group, dexamethasone group and Tubastatin A Hcl group with 12 mice in each group. Then the airway hyperresponsiveness was assessed in each group; total cell number, different cell number, levels of Interleukin (IL)-4, IL-5 and Interferon-γ (IFN-γ) in the bronchoalveolar lavage fluid (BALF) were detected; the lung tissues of each group were stained with HE to observe the inflammatory cells infiltration. AB-PAS was used to observe the goblet cell metaplasia in tracheal epithelium. Masson staining was used to observe the collagen deposition in lung tissue. Results: The airway reactivity in Tubastatin A Hcl group was significantly lower than that in asthma group [(4.18±0.94) vs (6.02±0.47), P<0.05]; in the Tubastatin A Hcl group, the total inflammatory cells [(57.0±5.7)×10(4)/ml vs (87.0±5.6)×10(4)/ml], eosinophil cells [(6.8±1.7)×10(4)/ml vs (12.3±3.5)×10(4)/ml] and levels of IL-4 [(19.3±2.7) vs (26.2±3.2)ng/ml] in BALF were obviously lower than those of asthma group (all P<0.05); IL-5 in Tubastatin A Hcl group was lower and IFN-γ was higher than that of asthma group, while there were no significant differences (both P>0.05). The degree of inflammatory cells infiltrations around the airway and vascular, number of inflammatory cells [(9.80±2.42) vs (20.67±7.53)], score of inflammation [(2.20±0.70) vs (3.60±0.68) points, ], and percentage of goblet cell metaplasia [(50.46±5.03)% vs (71.06±5.38)%] in the lung tissue of Tubastatin A Hcl group were lower than that of asthma group (all P<0.05). Although collagen deposition in the lung tissue of Tubastatin A Hcl group was lower than asthma group, there were no significant differences (P>0.05). However, all of the above results in the dexamethasone group were slightly better than Tubastatin A Hcl group, which had no significant differences (P>0.05). Conclusion: Tubastatin A Hcl can effectively alleviate the level of airway inflammation in acute asthma, but its anti-inflammatory effect is limited, which is not as significant as dexamethasone.

Inhibition of MicroRNA-21 by an antagomir ameliorates allergic inflammation in a mouse model of asthma

ABSTRACTAim of the Study: MicroRNA-21 (miR-21) is up-regulated during allergic airway inflammation, reflecting a Th2 immune response. We investigated the effects of an miR-21 antagomir and its mechanism of action in a mouse model of acute bronchial asthma. Materials and Methods: BALB/c mice were sensitized and challenged with ovalbumin (OVA). The anti-miR-21 antagomir was administered by intranasal inhalation from the day of sensitization. Changes in cell counts, Th2 cytokine levels in bronchoalveolar (BAL) fluid, and airway hyper-responsiveness (AHR) were examined. Histopathological changes and expression levels of miR-21 in lung tissues were analyzed. The mechanism of action of the antagomir was investigated by counting CD4+/CD8− T cells in splenocytes and by measuring the expression levels of transcription factors associated with T cell polarization. Results: MiR-21 expression was selectively down-regulated in the lung tissues of mice treated with anti-miR-21. The antagomir suppressed AHR compared with that of the OVA-challenged and scrambled RNA-treated groups. It also reduced the total cell and eosinophil counts in BAL fluid and the levels of Th2 cytokines, including IL-4, IL-5, and IL-13. The direct target of miR-21, IL-12p35, was induced in the antagomir-treated group, decreasing the CD4+/CD8− T cell proportions in splenocytes. The levels of transcription factors involved in the Th2-signaling pathway were reduced in lung tissues on treatment with the antagomir. Conclusions: The miR-21 antagomir suppresses the development of allergic airway inflammation in a mouse model of acute bronchial asthma, inhibiting Th2 activation. These results suggest that this antagomir might be useful for treating bronchial asthma.

Culture supernatant of adipose stem cells can ameliorate allergic airway inflammation via recruitment of CD4+CD25+Foxp3 T cells

BackgroundIn a previous study, we demonstrated that intravenous administration of adipose tissue stem cells (ASCs) could significantly reduce allergic symptoms and suppress eosinophilic inflammation.MethodsTo evaluate the secretome of ASCs, we administrated culture supernatant of ASCs (ASC sup, which contains the ASC secretome) and uncultured fresh medium (con sup) into a mouse model of allergic airway inflammation. Subsequently we observed the mice for signs of inflammation and investigated Th1-, Th2-, and Treg-related cytokine levels as well as recruitment of Treg cells into the airway.ResultsWe found that ASC sup could ameliorate allergic airway inflammation in this model; the value of airway hyperresponsiveness, and the occurrence of inflammatory cell infiltration in the lung, as well as the number of eosinophils, and goblet cells in the lung epithelium were all significantly decreased by ASC sup treatment. In addition, ASC sup treatment significantly decreased the levels of IL-4, IL-5, and IL-13 in the bronchial alveolar lavage fluid and in culture medium of lung-draining lymph node cells of the animal model of acute asthma. We detected numerous CTLA-4 and Foxp3-expressing cells in the lung after ASC sup treatment. ASC sup was found to have a higher concentration of IL-10 and TGF-β compared to con sup.ConclusionsStem cells have powerful potential for therapeutic functions in various diseases, but they also have many drawbacks. In this study, we found strong immunosuppressive ability of ASC sup in an allergic airway mouse model. It may be possible to use ASC sup for treatment of many immunological diseases in the near future.

Redistribution of adrenomedullary nicotinic acetylcholine receptor subunits and the effect on circulating epinephrine levels in a murine model of acute asthma.

The lack of circulating epinephrine (EPI) in the pathogenesis of asthma has long been attributed to the lack of adrenergic nerves in human airways. However, in this study we considered that EPI levels are regulated by EPI release in addition to synthesis. Nicotinic acetylcholine receptors (nAChRs) have been shown to control EPI release, and we hypothesized that redistribution of nAChR subunits modulates EPI release and circulating EPI levels. Using a mouse model of asthma, circulating EPI levels were measured by enzyme-linked immunosorbent assays. Changes in the expression of nAChR subunits in the adrenal medulla were observed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Expression of phenylethanolamine N-methyltransferase, tyrosine hydroxylase and galanin was detected by RT-qPCR. Lung pathology, airway resistance (RL) and EPI levels were also assessed after treatment with an α7 nAChR agonist or antagonist. α7 nAChR mRNA expression in the adrenal medulla was increased by more than 2-fold (P<0.05), and circulating EPI levels increased rapidly after treatment with the α7 nAChR agonist. These results indicated that increased EPI release, which was caused by the overexpression of α7 nAChR, was responsible for elevated circulating EPI levels. After treatment with an agonist of α7 nAChR, RL was significantly decreased. Serum corticosterone levels in individual mice were measured to rule out glucocorticoid as the main mediator of changes in EPI levels. On the whole, redistribution of nAChR subunits, primarily α7 nAChR, occurs in the adrenal medulla in asthmatic mice. Increased α7 nAChR expression can rapidly increase serum EPI levels and decrease airway responsiveness.

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.

Improvement of Th1/Th2 and Th1/Treg Imbalances by Adjutants CPG, MPLA and BCG in a Model of Acute Asthma Induced By Allergen Derp2 in BALB/c Mice

Background: The imbalance in the T helper (Th) 1/Th2 and Th1/T regulatory (Treg) cells-related immune responses plays a key role in pathogenesis of allergic asthma. Objectives: The aim of this study was to evaluate the eects of CPG-Oligodeoxynucleotide (CPG-ODN), Monophosphoryl Lipid A (MPLA) and Bacillus Calmette-Guerin (BCG) on the ratio of Th1/Th2 and Th1/Treg cells-related parameters in an animal model of asthma. Methods: This was an experimental study in which female BALB/c mice were divided to five groups and then immunized Subcuta- neously (SC) with the allergen Dermatophagoides pteronyssinus 2 (Derp2) on days 1, 15 and 22. Three groups of mice were consid- ered as test groups and pre-treated SC with CPG, CPG + MPLA or CPG + BCG on days 0, 14 and 21. Two groups were also considered as saline-control group and Derp2-sensitized control group that were administrated only saline or allergen Derp2, respectively. The mice (except saline-control group) were challenged intranasally with allergen Derp2 for ten days, from days 28 to 37 of post im- munization. Blood samples were obtained from retro-orbital sinus, on days 0, 23 and 40. The serum Interleukin (IL)-4, Interferon (IFN)- , Immunoglobulin (Ig) E and IgG2a levels were measured using the enzyme linked immunosorbent assay (ELISA) technique. The blood count of Th1- and Treg cells was detected using flow cytometry. Results: At sensitization phase, the serum IFN- /IL4 ratio was significantly increased in Derp2-sensitized group pre-treated with CPG plus MPLA or CPG plus BCG as compared with Derp2-sensitized control mice (P < 0.002 and P < 0.003). The IFN- /IL4 ratio was also markedly elevated in Derp2-sensitized group pre-treated with CPG as compared with Derp2-sensitized control mice (P = 0.07). In the challenge phase, the IFN- /IL4, IgG2a/IgE and Th1/Treg ratios in Derp2-sensitized mice pre-treated with CPG plus MPLA were significantly higher than in Derp2-sensitized control mice (P < 0.003, P < 0.006 and P < 0.003, respectively). The IFN- /IL4 and Th1/Treg ratios were also significantly raised in Derp2-sensitized mice pre-treated with CPG plus BCG in comparison with Derp2- sensitized control mice (P < 0.001 and P = 0.012, respectively). In the challenge phase the Th1/Treg ratio was significantly decreased in Derp2-sensitized group pre-treated with CPG plus BCG in comparison with Derp2-sensitized mice pre-treated with CPG (P = 0.011). The Th1/Treg ratio in Derp2-sensitized group pre-treated with CPG plus MPLA was significantly higher than in Derp2-sensitized mice pre-treated with CPG plus BCG (P < 0.035). Conclusions: These results showed that BCG, MPLA and CPG improve the Th1/Th2- and Th1/Treg cells imbalances in a mouse model of asthma.

Baicalin attenuates inflammation in mice with OVA-induced asthma by inhibiting NF-κB and suppressing CCR7/CCL19/CCL21.

Baicalin, extracted and purified from the Chinese medicinal plant, ScutellariabaicalensisGeorgi(Huangqin in Chinese), exhibits potent anti-inflammatoryactivity against asthma. However, it remains unknown whether baicalin inhibits the activity of CCchemokinereceptor7(CCR7) and its ligands, which are crucial for the initiation of airway inflammation. In the present study, we investigated the effects of baicalin on CCR7 and its ligands, CCL19 andCCL21, as well as on the nuclear factor-κB(NF-κB)pathway in a mouse model of asthma. A mouse model of acute asthma was established by exposing the mice to ovalbumin(OVA) (by intraperitoneal injection and inhalational challenge). Within 24h of the final OVAchallenge, lung function was detected by direct airway resistance analysis. Lung tissues were examined for pathological changes. Inflammatory cell counts in bronchoalveolar lavage fluid(BALF) were assessed. ELISA was utilized to evaluate the OVA-IgE, CCL19 and CCL21 levels in BALF. The interleukin(IL)-6and tumor necrosis factor(TNF)-α levels in serum were also detected by ELISA. The protein expression levels of CCR7, as well as that of phosphorylatedIκBα(p-IκBα) and phosphorylatedp65(p-p65) were determined by western blot analysis and RT-qPCR was used to determine the CCR7mRNA levels. Our data demonstrated that the oral administration of baicalin significantly improved pulmonaryfunction and attenuated inflammatory cell infiltration into the lungs. Baicalin also decreased the levels of OVA-IgE, IL-6, TNF-α and CCR7, as well as those of its ligand, CCL19; the levels of NF-κB were also markedly suppressed by baicalin. The CCR7mRNA level was substantially decreased. Our results thus suggest that baicalin exerts an inhibitory effect on airwayinflammation, and this effect may be associated with the inhibition of CCR7 and CCL19/CCL21, which may provide new mechanistic insight into the anti‑inflammatoryeffects of baicalin.

Effects of grape seed proanthocyanidin extract on airway inflammation and Treg/Th17 balance in asthmatic mice

Objective To explore effect of grape seed proanthocyanidin extract(GSPE)on airway inflammation and hyperresponsiveness of ovalbumin-induced murine asthma model and the associated regulatory effect on Treg/Th17 imbalance. Methods A total of 40 mice were randomly assigned to four experimental groups: control, asthma model, low dose GSPE(40 mg/kg), and high dose GSPE(80 mg/kg). Acute asthma model was established with OVA; airway responsiveness of mice in each group was measured with a noninvasive pulmonary function instrument; lung inflammation changes were observed by pathological HE staining; Treg/Th17 cytokines levels in bronchoalveolar lavage fluid were evaluated by ELISA; the expressions of forkhead/winged helix transcription factor(Foxp3)mRNA and retinoid-related orphan receptor gammat(RORγt)mRNA in lung tissue of each group were gained by Real-time PCR method. Results GSPE inhibited ovalbumin-induced increases in airway responsiveness(P<0.05). Histological studies demonstrated that GSPE substantially inhibited OVA-induced airway inflammation in lung tissue.GSPE decreased IL-17A levels and increased IL-10 levels in bronchoalveolar lavage fluid(P<0.05). In the asthma model group, RORγt mRNA expression in lung tissue was significantly higher than that in the control group(P<0.05)and Foxp3 mRNA expression was significantly lower than that in the control group(P<0.05). In the GSPE group, RORγt mRNA expression was lower than that in asthma model group(P<0.05), however the Foxp3 mRNA expression was higher than that in asthma model group(P<0.05). Conclusion GSPE could alleviate airway hyperresponsiveness and airway inflammation of in asthmatic mice.It can modify the asthmatic mice Treg/Th17 imbalance by decreasing IL-17A and increasing IL-10 concentration at the level of cytokines; and also by increasing Foxp3 mRNA expression and inhibiting the expression of RORγt mRNA at the transcriptional level, which provide a new way for treatment of bronchial asthma. Key words: Grape seed proanthocyanidin extract; Asthma; Forkhead/winged helix transcription factor; Retinoid-related orphan receptor gammat

Mouse Models ofAsthma.

Allergic asthma is a chronic inflammatory disease of the conducting airways characterized by the presence of allergen-specific IgE, Th2 cytokine production, eosinophilic airway inflammation, bronchial hyperreactivity, mucus overproduction, and structural changes in the airways. Investigators have tried to mimic these features of human allergic asthma in murine models. Whereas the surrogate allergen ovalbumin has been extremely valuable for unravelling underlying mechanisms of the disease, murine asthma models depend nowadays on naturally occurring allergens, such as house dust mite (HDM), cockroach, and Alternaria alternata. Here we describe a physiologically relevant model of acute allergic asthma based on sensitization and challenge with HDM extracts, and compare it with the ovalbumin/alum-induced asthma model. Moreover, we propose a detailed readout of the asthma phenotype, determining the degree of eosinophilia in bronchoalveolar lavage fluids by flow cytometry, visualizing goblet cell metaplasia, and measuring Th cytokine production by lung-draining mediastinal lymph node cells restimulated with HDM. © 2016 by John Wiley & Sons, Inc.

The Role of Regulator of G-Protein-Signaling 4 (RGS4) in Control of Airway Hyper-responsiveness in Asthma

Abstract Asthma is a common respiratory disease characterized by airway hyper-responsiveness (AHR), inflammation, and airway obstruction. In most patients, this disease can be managed with steroids and bronchodilators. However, these treatments are not effective for the 15%-25% of patients with severe asthma who may develop fixed airway obstruction due to increased airway smooth muscle (ASM) mass. ASM cells control airway patency through G-protein coupled receptors (GPCRs). Namely, GPCRs can activate the IP3 pathway to induce calcium release and airway contraction. Regulators of G-protein signaling (RGS) are a family of proteins that are known to negatively regulate the activity of GPCRs. In ASM cells, RGS4 is relatively abundant compared to other RGS4 proteins. In people with asthma, increased RGS4 expression is observed in the group with greatest impairment in lung function. We hypothesize that aberrant RGS4 expression and/or function contributes to AHR through dysregulated GPCR signaling in ASM cells. We studied bacterial artificial chromosome (BAC) transgenic (Tg) mice, which overexpress both RGS4 and eGFP under the control of endogenous RGS4 promoter. In models of acute asthma, Tg mice exhibited reduced AHR as assessed by measurements of lung resistance in live, anesthetized mice and contraction of precision cut lung slices. These findings suggest that RGS4 is an important controller of bronchial tone in asthma through its effects on contraction signaling in ASM cells.

Revealing the acute asthma ignorome: characterization and validation of uninvestigated gene networks.

Systems biology provides opportunities to fully understand the genes and pathways in disease pathogenesis. We used literature knowledge and unbiased multiple data meta-analysis paradigms to analyze microarray datasets across different mouse strains and acute allergic asthma models. Our combined gene-driven and pathway-driven strategies generated a stringent signature list totaling 933 genes with 41% (440) asthma-annotated genes and 59% (493) ignorome genes, not previously associated with asthma. Within the list, we identified inflammation, circadian rhythm, lung-specific insult response, stem cell proliferation domains, hubs, peripheral genes, and super-connectors that link the biological domains (Il6, Il1ß, Cd4, Cd44, Stat1, Traf6, Rela, Cadm1, Nr3c1, Prkcd, Vwf, Erbb2). In conclusion, this novel bioinformatics approach will be a powerful strategy for clinical and across species data analysis that allows for the validation of experimental models and might lead to the discovery of novel mechanistic insights in asthma.

Cannabinoid receptor 2 augments eosinophil responsiveness and aggravates allergen-induced pulmonary inflammation in mice.

BackgroundAccumulation of activated eosinophils in tissue is a hallmark of allergic inflammation. The endocannabinoid 2‐arachidonoylglycerol (2‐AG) has been proposed to elicit eosinophil migration in a CB 2 receptor/Gi/o‐dependent manner. However, it has been claimed recently that this process may also involve other mechanisms such as cytokine priming and the metabolism of 2‐AG into eicosanoids. Here, we explored the direct contribution of specific CB 2 receptor activation to human and mouse eosinophil effector function in vitro and in vivo.Methods In vitro studies including CB 2 expression, adhesion and migratory responsiveness, respiratory burst, degranulation, and calcium mobilization were conducted in human peripheral blood eosinophils and mouse bone marrow‐derived eosinophils. Allergic airway inflammation was assessed in mouse models of acute OVA‐induced asthma and directed eosinophil migration.Results CB 2 expression was significantly higher in eosinophils from symptomatic allergic donors. The selective CB 2 receptor agonist JWH‐133 induced a moderate migratory response in eosinophils. However, short‐term exposure to JWH‐133 potently enhanced chemoattractant‐induced eosinophil shape change, chemotaxis, CD11b surface expression, and adhesion as well as production of reactive oxygen species. Receptor specificity of the observed effects was confirmed in eosinophils from CB 2 knockout mice and by using the selective CB 2 antagonist SR144528. Of note, systemic application of JWH‐133 clearly primed eosinophil‐directed migration in vivo and aggravated both AHR and eosinophil influx into the airways in a CB 2‐specific manner. This effect was completely absent in eosinophil‐deficient ∆dblGATA mice.ConclusionOur data indicate that CB 2 may directly contribute to the pathogenesis of eosinophil‐driven diseases. Moreover, we provide new insights into the molecular mechanisms underlying the CB 2‐mediated priming of eosinophils. Hence, antagonism of CB 2 receptors may represent a novel pharmacological approach for the treatment of allergic inflammation and other eosinophilic disorders.

Potential of PEGylated Toll-Like Receptor 7 Ligands for Controlling Inflammation and Functional Changes in Mouse Models of Asthma and Silicosis.

Prior investigations show that signaling activation through pattern recognition receptors can directly impact a number of inflammatory lung diseases. While toll-like receptor (TLR) 7 agonists have raised interest for their ability to inhibit allergen-induced pathological changes in experimental asthma conditions, the putative benefit of this treatment is limited by adverse effects. Our aim was to evaluate the therapeutic potential of two PEGylated purine-like compounds, TMX-302 and TMX-306, characterized by TLR7 partial agonistic activity; therefore, the compounds are expected to induce lower local and systemic adverse reactions. In vitro approaches and translation to murine models of obstructive and restrictive lung diseases were explored. In vitro studies with human PBMCs showed that both TMX-302 and TMX-306 marginally affects cytokine production as compared with equivalent concentrations of the TLR7 full agonist, TMX-202. The PEGylated compounds did not induce monocyte-derived DC maturation or B cell proliferation, differently from what observed after stimulation with TMX-202. Impact of PEGylated ligands on lung function and inflammatory changes was studied in animal models of acute lung injury, asthma, and silicosis following Lipopolysaccharide (LPS), allergen (ovalbumin), and silica inhalation, respectively. Subcutaneous injection of TMX-302 prevented LPS- and allergen-induced airway hyper-reactivity (AHR), leukocyte infiltration, and production of pro-inflammatory cytokines in the lung. However, intranasal instillation of TMX-302 led to neutrophil infiltration and failed to prevent allergen-induced AHR, despite inhibiting leukocyte counts in the BAL. Aerosolized TMX-306 given prophylactically, but not therapeutically, inhibited pivotal asthma features. Interventional treatment with intranasal instillation of TMX-306 significantly reduced the pulmonary fibrogranulomatous response and the number of silica particles in lung interstitial space in silicotic mice. These findings highlight the potential of TMX-306, emphasizing its value in drug development for lung diseases, and particularly silicosis.

Recombinant human deoxyribonuclease therapy improves airway resistance and reduces DNA extracellular traps in a murine acute asthma model

ABSTRACTPurpose: Asthma is a highly prevalent chronic inflammatory lung disease characterized by airway hyperresponsiveness to allergens, airway edema, and increased mucus secretion. Such mucus can be liquefied by recombinant human deoxyribonuclease (rhDNase), in which efficacy of rhDNase has been well documented in patients with cystic fibrosis, but little studied in asthma. In the present study, we investigated whether rhDNase intranasal administration improved inflammation and pulmonary function in an experimental model of asthma. Methods: Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three intranasal challenges with OVA on days 14, 15, and 16. A control group, replacing OVA by DPBS, was included. On days 15 and 16, after 2 hours of OVA challenge, mice received 1 mg/mL of intranasal rhDNase. Results: We showed that rhDNase decreased significantly the airway resistance and reduced EETs formation and globet cells hyperplasia. Conclusions: Our results suggest that extracellular DNA in mucus play a role in lower airways obstruction in OVA asthma protocol and that the treatment with rhDNase improved lung function and DNA extracellular traps, with no direct cellular anti-inflammatory effects.

Combination therapy of tiotropium and ciclesonide attenuates airway inflammation and remodeling in a guinea pig model of chronic asthma.

BackgroundThe long-acting anticholinergic tiotropium has recently been registered for the treatment of asthma, and its use is associated with a reduction in exacerbation frequency. Anti-inflammatory and anti-remodeling effects of tiotropium have been demonstrated in in vitro and in vivo models. Because tiotropium treatment is used in combination with inhaled corticosteroids, potential additive effects between the two would be clinically relevant. Therefore, the aim of this study was to investigate additive effects between tiotropium and ciclesonide on airway inflammation and remodeling in guinea pig models of asthma.MethodsGuinea pigs (n = 3–8/group) were sensitized and challenged with ovalbumin in an acute (single challenge) and a chronic model (12 weekly challenges) of allergic asthma. Animals were treated with vehicle, nebulized tiotropium (0.01–0.3 mM) and/or intranasally instilled ciclesonide (0.001–1 mg/kg) before each challenge. Bronchoalveolar lavage fluid and lungs were collected for analysis of airway inflammation and remodeling.ResultsTiotropium and ciclesonide treatment, alone or in combination, did not inhibit airway inflammation in the acute asthma model. In a dose-finding study, low doses of tiotropium and ciclesonide inhibited airway eosinophilia and airway smooth muscle thickening in the chronic asthma model. Threshold doses of 0.01 mM tiotropium (nebulizer concentration) and 0.01 mg/kg ciclesonide were selected to investigate potential additive effects between both drugs. At these doses, tiotropium and ciclesonide did not inhibit airway eosinophilia or airway smooth muscle thickening when administered alone, but significantly inhibited these allergen-induced responses when administered in combination.ConclusionsCombined treatment with low doses of tiotropium and ciclesonide inhibits airway inflammation and remodeling in a guinea pig model of chronic asthma, suggesting that combined treatment with anticholinergics and corticosteroids may have anti-inflammatory and anti-remodeling activity in allergic airway diseases. Since tiotropium is registered as a therapy for asthma added on to corticosteroid treatment, these beneficial effects of the combination therapy may be clinically relevant.Electronic supplementary materialThe online version of this article (doi:10.1186/s12931-016-0327-6) contains supplementary material, which is available to authorized users.

Functional Role of FcγRIIB in the Regulation of Mesenchymal Stem Cell Function.

Mesenchymal stem cells (MSCs) derived from bone marrow are plural-potent stem cells with immune regulatory functions. We aimed to evaluate role of FcγRIIB in the regulation of bone marrow-derived MSC function. MSCs were prepared from mouse bone marrow derived from wild-type (WT) or FcγRIIB-deficient (FcγRIIB-/-) mice. MSCs were co-cultured with bone marrow-derived dendritic cells (BMDCs), and BMDC maturation and function were evaluated by flow cytometric analysis and carboxyfluorescein succinimidyl ester-labeled OT-II T-cell addition. An acute asthma model was established by aeresol ovalbumin challenge in mice. Mice received WT or FcγRIIB-/- MSC therapy. Lung function was evaluated by histological examination and cytokine production measurement. mRNA and protein expression levels of target genes were examined by real-time quantitative polymerase chain reactionor western blotting. We found that MSCs derived from bone marrow exhibit a high level of FcγRIIB expression. FcγRIIB deficiency impaired the suppressive function of MSCs, as FcγRIIB deficiency efficiently reversed the inhibitory effect of MSCs on BMDC maturation and function. Additionally, FcγRIIB-/-MSCs were less potent at suppressing asthma in model mice, possibly through reduced expression of Smad2, Smad3, Cox-2, and prostaglandin E2 in FcγRIIB-/-MSCs. FcγRIIB might play an essential role in regulating the inhibitory effects of MSCs derived from bone marrow.

The metabonomic study of Shaoyao-Gancao decoction in a rat model of acute bronchial asthma by1H NMR

Shaoyao-Gancao decoction (SGD), a traditional Chinese herbal medicine, was originally described in theTreatise on Cold Pathogenic Diseasesand is composed ofPaeoniae Radix albaandGlycyrrhiza Radix et rhizoma.