Murine Model Of Chronic Asthma Research Articles

Inhibition of Macrophage-Specific CHIT1 as an Approach to Treat Airway Remodeling in Severe Asthma.

Chitotriosidase (CHIT1) is an enzyme produced by macrophages that regulates their differentiation and polarization. Lung macrophages have been implicated in asthma development; therefore, we asked whether pharmacological inhibition of macrophage-specific CHIT1 would have beneficial effects in asthma, as it has been shown previously in other lung disorders. CHIT1 expression was evaluated in the lung tissues of deceased individuals with severe, uncontrolled, steroid-naïve asthma. OATD-01, a chitinase inhibitor, was tested in a 7-week-long house dust mite (HDM) murine model of chronic asthma characterized by accumulation of CHIT1-expressing macrophages. CHIT1 is a dominant chitinase activated in fibrotic areas of the lungs of individuals with fatal asthma. OATD-01 given in a therapeutic treatment regimen inhibited both inflammatory and airway remodeling features of asthma in the HDM model. These changes were accompanied by a significant and dose-dependent decrease in chitinolytic activity in BAL fluid and plasma, confirming in vivo target engagement. Both IL-13 expression and TGFβ1 levels in BAL fluid were decreased and a significant reduction in subepithelial airway fibrosis and airway wall thickness was observed. These results suggest that pharmacological chitinase inhibition offers protection against the development of fibrotic airway remodeling in severe asthma.

Dexmedetomidine Protects against Airway Inflammation and Airway Remodeling in a Murine Model of Chronic Asthma through TLR4/NF-κB Signaling Pathway.

Asthma is a common respiratory disease characterized by chronic airway inflammation. Dexmedetomidine (DEX), a highly selective α2 adrenergic receptor agonist, has been shown to participate in regulating inflammatory states and thus exert organ protective actions. However, the potential of DEX in asthma is still unknown. This study is aimed at investigating the role of DEX in a mouse model of house dust mite- (HDM-) induced asthma and exploring its underlying mechanism. Here, we found that DEX treatment significantly ameliorated airway hyperresponsiveness, airway inflammation, and airway remodeling in the asthmatic mice, which were similar to the efficacy of the reference anti-inflammatory drug dexamethasone. In addition, DEX reversed the increased expression of toll-like receptor 4 (TLR4) and its downstream signaling adaptor molecule nuclear factor-κB (NF-κB) in the lung tissue of asthmatic mice. Furthermore, these protective effects of DEX were abolished by yohimbine, an α2 adrenergic receptor antagonist. These results indicate that DEX is capable of ameliorating airway inflammation and remodeling in asthmatic mice, and this protective effect is associated with the inhibition of the TLR4/NF-κB signaling pathway.

The hybrid protein BTH2 suppresses allergic airway inflammation in a murine model of HDM-specific immunotherapy.

Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment approach to change disease-causing allergens. Hypoallergenic derivatives show promise as potential therapeutics, amongst which BTH2 was designed to induce tolerance against Blomia tropicalis allergy. Our aim was to investigate the hypoallergenicity and immunoregulatory activity of BTH2 in vitro and its therapeutic potential in a mouse model of AIT. Recombinant Blo t 5 and Blo t 21 allergens and their hybrid derivatives (BTH1 and BTH2) were expressed and purified. IgE binding capacity was tested by ELISA using sera from Brazilian, Colombian, and Ecuadorian subjects. Secretion of cytokines in supernatants from human cell cultures was measured following stimulation with the four recombinants and controls. The capacity of BTH2 to ameliorate allergic airway inflammation induced by B.tropicalis extract was evaluated in a murine model of AIT. rBlo t 5 and rBlo t 21 were identified as major allergens in Latin American patients, and BTH2 had the lowest IgE binding. In vitro stimulation of human cells induced greater levels of IL-10 and IFN-γ and reduced the secretion of Th2 cytokines. BTH2 ameliorated allergic airway inflammation in B.tropicalis-challenged A/J mice, as evidenced by the histopathological and humoral biomarkers: decreased Th2 cytokines and cellular infiltration (especially eosinophils), lower activity of eosinophil peroxidase, an increase in IgG blocking antibodies and strong reduction of mucus production by goblet cells. Our study shows that BTH2 represents a promising candidate for the treatment of B.tropicalis allergy with hypoallergenic, immune regulatory and therapeutic properties. Further pre-clinical studies are required in murine models of chronic asthma to further address the efficacy and safety of BTH2 as a vaccine against B.tropicalis-induced allergy.

Effects of human adipose tissue- and bone marrow-derived mesenchymal stem cells on airway inflammation and remodeling in a murine model of chronic asthma

It is challenging to overcome difficult-to-treat asthma, and cell-based therapies are attracting increasing interest. We assessed the effects of mesenchymal stem cell (MSC) treatments using a murine model of chronic ovalbumin (OVA)-challenged asthma. We developed a murine model of chronic allergic asthma using OVA sensitization and challenge. Human adipose-derived MSCs (hADSCs) or human bone marrow-derived MSCs (hBMSCs) were administered. We measured the levels of resistin-like molecule-β (RELM-β). We also measured RELM-β in asthma patients and normal controls. OVA-challenged mice exhibited increased airway hyper-responsiveness, inflammation, and remodeling. hBMSC treatment remarkably decreased airway hyper-responsiveness but hADSC treatment did not. Both MSCs alleviated airway inflammation, but hBMSCs tended to have a more significant effect. hBMSC treatment reduced Th2-cytokine levels but hADSC treatment did not. Both treatments reduced airway remodeling. The RELM-β level decreased in the OVA-challenged control group, but increased in both treatment groups. We found that the serum level of RELM-β was lower in asthma patients than controls. MSC treatments alleviated the airway inflammation, hyper-responsiveness, and remodeling associated with chronic asthma. hBMSCs were more effective than hADSCs. The RELM-β levels increased in both treatment groups; the RELM-β level may serve as a biomarker of MSC treatment efficacy.

Mesenchymal stem cells exert their anti-asthmatic effects through macrophage modulation in a murine chronic asthma model

Despite numerous previous studies, the full action mechanism of the pathogenesis of asthma remains undiscovered, and the need for further investigation is increasing in order to identify more effective target molecules. Recent attempts to develop more efficacious treatments for asthma have incorporated mesenchymal stem cell (MSC)-based cell therapies. This study aimed to evaluate the anti-asthmatic effects of MSCs primed with Liproxstatin-1, a potent ferroptosis inhibitor. In addition, we sought to examine the changes within macrophage populations and their characteristics in asthmatic conditions. Seven-week-old transgenic mice, constitutively overexpressing lung-specific interleukin (IL)-13, were used to simulate chronic asthma. Human umbilical cord-derived MSCs (hUC-MSCs) primed with Liproxstatin-1 were intratracheally administered four days prior to sampling. IL-13 transgenic mice demonstrated phenotypes of chronic asthma, including severe inflammation, goblet cell hyperplasia, and subepithelial fibrosis. Ly6C+M2 macrophages, found within the pro-inflammatory CD11c+CD11b+ macrophages, were upregulated and showed a strong correlation with lung eosinophil counts. Liproxstatin-1-primed hUC-MSCs showed enhanced ability to downregulate the activation of T helper type 2 cells compared to naïve MSCs in vitro and reduced airway inflammation, particularly Ly6C+M2 macrophages population, and fibrosis in vivo. In conclusion, intratracheal administration is an effective method of MSC delivery, and macrophages hold great potential as an additional therapeutic target for asthma.

CD44 is critical for the enhancing effect of hyaluronan in allergen-specific sublingual immunotherapy in a murine model of chronic asthma.

Allergen-specific sublingual immunotherapy (SLIT) is a potentially effective disease-modification treatment for patients with allergic asthma. Because CD44 signaling enhances regulatory T (Treg) cell-induction, administering CD44 ligands such as hyaluronan (HA) with allergen-specific SLIT may enhance the therapeutic effects. We evaluated the role of CD44 in Treg cell-induction in T helper type 2 (Th2)-mediated chronic airway inflammation using CD44-/- mice and the efficacy of HA on SLIT in a Dermatophagoides farinae (Df)-induced murine model of chronic asthma. Th2 responses and Treg cell induction were evaluated in CD44-/- mice. We devised a new SLIT model of Df-induced chronic asthma utilizing HA as an adjuvant. The effects of HA added to the new SLIT model were evaluated by the early asthmatic response (EAR) and airway hyperresponsiveness (AHR), eosinophilic airway inflammation, and serum Df-specific IgE levels. Th2-mediated chronic eosinophilic airway inflammation was worse in CD44-/- mice compared with Df-sensitized wild-type (WT) mice. HA enhanced the effect of Df-induced Treg cells in a CD44-dependent manner. Sublingual Df treatment in combination with HA, but not alone, normalized EAR and AHR, and significantly reduced the serum IgE levels and the bronchoalveolar lavage fluid (BALF) eosinophil number. HA also induced Treg cells in a Df-sensitized spleen cell culture in a CD44-dependent manner. The treatment-enhancing effects of HA in this SLIT model were diminished in CD44-/- mice. CD44 is a key contributor to Treg cell induction and critical for the enhancing effects of HA in a Df-induced murine model of chronic asthma.

Photobiomodulation Therapy Restores IL-10 Secretion in a Murine Model of Chronic Asthma: Relevance to the Population of CD4+CD25+Foxp3+ Cells in Lung.

It is largely known that photobiomodulation (PBM) has beneficial effects on allergic pulmonary inflammation. Our previous study showed an anti-inflammatory effect of the PBM in an acute experimental model of asthma, and we see that this mechanism is partly dependent on IL-10. However, it remains unclear whether the activation of regulatory T cells is mediated by PBM in a chronic experimental model of asthma. In this sense, the objective of this study was to verify the anti-inflammatory role of the PBM in the pulmonary inflammatory response in a chronic experimental asthma model. The protocol used for asthma induction was the administration of OVA subcutaneously (days 0 and 14) and intranasally (3 times/week, for 5 weeks). On day 50, the animals were sacrificed for the evaluation of the different parameters. The PBM used was the diode, with a wavelength of 660 nm, a power of 100 mW, and 5 J for 50 s/point, in three different application points. Our results showed that PBM decreases macrophages, neutrophils, and lymphocytes in the bronchoalveolar lavage fluid (BALF). Moreover, PBM decreased the release of cytokines by the lung, mucus, and collagen in the airways and pulmonary mechanics. When we analyzed the percentage of Treg cells in the group irradiated with laser, we verified an increase in these cells, as well as the release of IL-10 in the BALF. Therefore, we conclude that the use of PBM therapy in chronic airway inflammation attenuated the inflammatory process, as well as the pulmonary functional and structural parameters, probably due to an increase in Treg cells.

Cyclo-VEGI inhibits bronchial artery remodeling in a murine model of chronic asthma

Purpose/Aim: In the context of asthma, airway bronchial remodeling and angiogenesis in the bronchial mucosa are well established. Cyclopeptidic-vascular endothelial growth inhibitor (cyclo-VEGI) is an inhibitor of the vascular endothelial growth factor (VEGF) receptor that increases the proliferation of endothelial cells and the formation of new vessels. However, changes in the bronchial arteries of patients with asthma have not been clearly elucidated. We investigated whether structural changes occurred in bronchial arteries, as well as the effects of cyclo-VEGI in a mouse model of chronic asthma (in vivo) and human fibroblasts (in vitro). Materials and Methods: A validated mouse model of allergic airway inflammation with ovalbumin (OVA) as the causative allergen was used for the study. Mice were treated with cyclo-VEGI or fluticasone during OVA challenge. In vitro experiments were conducted to determine whether fibroblasts proliferated following elastin exposure and the effects of cyclo-VEGI on them. Results: OVA sensitization and challenge led to greater perivascular smooth muscle area, more elastic fibers, and elevated expression of vascular cell adhesion molecule (VCAM)-1 antigen. These phenomena indicated changes to bronchial arteries. Cyclo-VEGI and fluticasone treatment both inhibited airway hyper-responsiveness and inflammation. Cyclo-VEGI-treated mice exhibited decreased perivascular smooth muscle area, elastin fibers, and VCAM-1 expression. Fluticasone-treated mice exhibited reductions in perivascular smooth muscle but not in perivascular elastin or VCAM-1 expression. In vitro, fibroblast proliferation was enhanced by elastin treatment, which was inhibited by cyclo-VEGI treatment. Eotaxin expression was elevated in elastin-treated fibroblasts and decreased with cyclo-VEGI treatment. Conclusions: Vascular remodeling occurred in our mouse model of chronic asthma. Cyclo-VEGI could reduce airway inflammation and hyper-responsiveness by inhibiting VCAM-1 expression and elastin deposition around the bronchial arteries.

Progranulin Protects Against Airway Remodeling Through the Modulation of Autophagy via HMGB1 Suppression in House Dust Mite-Induced Chronic Asthma.

PurposeAirway remodeling is an important feature of chronic asthma, and yet there are few effective therapeutic strategies. Progranulin (PGRN) has been shown to have lung protective functions, but the role of PGRN in asthmatic airway remodeling is unclear. We aim to explore the protective potential of PGRN on house dust mite (HDM)-induced airway remodeling and the underlying mechanisms.MethodsIn this study, a murine model of chronic asthma was established by HDM sensitization and challenge. Recombinant PGRN was intranasally administrated to mice during the phase of HDM challenge. TGF-β1-treated human airway epithelial BEAS-2B cells were utilized to explore the effect of PGRN on airway epithelia exposed to profibrotic conditions and molecular mechanisms.ResultsWe found that PGRN treatment attenuated HDM-induced airway remodeling, as evidenced by the suppression of collagen accumulation, mucus overproduction and airway smooth muscle synthesis in HDM-challenged asthmatic mice lungs. Meanwhile, PGRN also reversed the increased levels of autophagy markers and autophagosomes in airway epithelia under mimic asthmatic conditions, thereby controlling the fibrotic process in vivo and in vitro. Specifically, overexpressed HMGB1 and the subsequent RAGE/MAPKs signaling activation due to HDM exposure were abrogated in PGRN-treated asthmatic mice. Furthermore, knockdown of HMGB1 expression significantly restrained the fibrosis formation in TGF-β1-induced airway epithelia accompanied by the downregulation of autophagic activity. However, enhancement of extracellular HMGB1 levels blunted the inhibition of autophagic flux by PGRN in airway epithelia, thereby resulting in the augmentation of collagen synthesis and fibrosis.ConclusionTaken together, our data revealed that PGRN protected against asthmatic airway remodeling by negatively regulating autophagy via HMGB1 suppression, which might provide new insights into the therapeutic options for HDM-induced chronic asthma.

Aryl hydrocarbon receptor deficiency enhanced airway inflammation and remodeling in a murine chronic asthma model

The aryl hydrocarbon receptor (AhR) is a ligand-dependent-activated transcriptional factor that regulates the metabolism of xenobiotic and endogenous compounds. Recent studies have shown that AhR is a novel master regulator of the mucosal immune system, including lungs and intestine. To elucidate the role of AhR in chronic severe asthma, AhR wild-type and knockout mice (AhR-/- ) were sensitized and challenged with ovalbumin for 4weeks. To uncover the underlying mechanisms, inflammatory cells profile and cytokines production were analyzed in bronchial lavage fluid (BALF) and lung tissue. Compared to wild-type mice, AhR-/- mice had exacerbated asthma symptoms, including airway inflammation, mucus production, airway hyperresponsiveness, and airway remodeling. BALF monocytes, neutrophils, eosinophils, and lymphocytes were all enhanced in OVA-immunized AhR-/- mice. In OVA-immunized AhR-/- mice, T helper (Th) 17 cell-specific cytokine IL-17A, as well as airway remodeling factors, including epithelial-mesenchymal transition (EMT) markers and vascular endothelial growth factor (VEGF), were all enhanced in lung tissue. Moreover, human cohort studies showed that AhR gene expression in bronchial epithelial cells decreases in severe asthma patients. Loss of AhR leads to worsening of allergic asthma symptoms, indicating its importance in maintaining normal lung function and mediating disease severity.

Synthesized atropine nanoparticles ameliorate airway hyperreactivity and remodeling in a murine model of chronic asthma

The synthesized aerosolized biodegradable atropine loaded nanoparticle (ANP) and its influence on lung hyperresponsiveness, obstruction, and inflammation was investigated in adult Wistar rats. ANP was synthesized with biodegradable polymers-poly (lactic-co-glycolic acid) and poly ethylene glycol and characterized. Pharmacokinetics and biodistribution of ANP and atropine sulphate powder were evaluated in lung hyperresponsive followed by lung obstructed experimental rats. ANP size ranges from 88.30 ± 7.54 nm and showed excellent pharmacokinetics over atropine dry powder Cmax (μg/mL) (4.9 ± 0.92 vs 3.5 ± 0.95), t1/2 (min) (266.90 ± 24.51 vs 125.44 ± 18.90). ANP inhibits inflammatory cytokines, reduced shallow breath and normalized the tidal volume of hyperresponsiveness and obstructed lung. Further, treatment with ANP for 18 days improved the progressive airway obstruction and reduced collagen deposition. Thus, ANP delivered as nanoparticle to lungs improves the airway surfaces of the lung and ameliorated lungs hyperresponsiveness, obstruction and inflammation.

Colony-stimulating factor 1 and its receptor are new potential therapeutic targets for allergic asthma.

A new approach targeting aeroallergen sensing in the early events of mucosal immunity could have greater benefit. The CSF1-CSF1R pathway has a critical role in trafficking allergens to regional lymph nodes through activating dendritic cells. Intervention in this pathway could prevent allergen sensitization and subsequent Th2 allergic inflammation. To examine the therapeutic effectiveness of CSF1 and CSF1R inhibition for blocking the dendritic cell function of sensing aeroallergens. We adopted a model of chronic asthma induced by a panel of three naturally occurring allergens and novel delivery system of CSF1R inhibitor encapsulated nanoprobe. Selective depletion of CSF1 in airway epithelial cells abolished the production of allergen-reactive IgE, resulting in prevention of new asthma development as well as reversal of established allergic lung inflammation. CDPL-GW nanoprobe containing GW2580, a selective CSF1R inhibitor, showed favorable pharmacokinetics for inhalational treatment and intranasal insufflation delivery of CDPL-GW nanoprobe ameliorated asthma pathologies including allergen-specific serum IgE production, allergic lung and airway inflammation and airway hyper-responsiveness (AHR) with minimal pulmonary adverse reaction. The inhibition of the CSF1-CSF1R signaling pathway effectively suppresses sensitization to aeroallergens and consequent allergic lung inflammation in a murine model of chronic asthma. CSF1R inhibition is a promising new target for the treatment of allergic asthma.

PARP inhibition by olaparib alleviates chronic asthma-associated remodeling features via modulating inflammasome signaling in mice.

Despite the reported role of poly(ADP-ribose) polymerase (PARP) in asthma inflammation, its contribution during remodeling is not clearly known. The main aim of the current investigation was to examine the potential of olaparib, a pharmacological inhibitor of PARP against airway remodeling using an ovalbumin (OVA)-based murine model of chronic asthma. The results demonstrated that post-challenge olaparib treatment (5 mg/kg i.p., 30 min after OVA exposure) for six weeks (3 days/week) attenuates inflammation, mucus production, and collagen deposition in lungs. Additionally, olaparib blunted the protein expression of STAT-6 and GATA-3 considerably along with a modest reduction in p65-NF-κB phosphorylation. Furthermore, olaparib normalized the OVA-induced redox imbalance as reflected by data on reactive oxygen species, malondialdehyde, protein carbonyls, and reduced glutathione/oxidized glutathione ratio. Interestingly, the protection offered by olaparib was further linked with the altered level of NLRP3 inflammasome-mediated IL-1β release and consequent expression of its downstream targets matrix metalloproteinase-9 and transforming growth factor beta. Suppressed collagen deposition in the lungs correlates well with the reduced expression of vimentin upon olaparib treatment. Finally, olaparib restored the expression of histone deacetylase 2, a steroid-responsive element in asthma. Overall, results suggest that olaparib prevents OVA-induced airway inflammation as well as remodeling via modulating inflammasome signaling in mice. © 2019 IUBMB Life, 1-11, 2019.

Modified Si-Jun-Zi-Tang Attenuates Airway Inflammation in a Murine Model of Chronic Asthma by Inhibiting Teff Cells via the mTORC1 Pathway.

Background: Modified Si–Jun–Zi–Tang (MSJZT), a multi-herb formulation, is frequently used in traditional Chinese medicine for patients during the remission stage of asthma. However, the pharmacological basis underlying the effects of MSJZT on asthma has yet to be elucidated. This study aims at evaluating the anti-asthmatic effects of MSJZT and investigating its possible mechanism.Methods: A chronic murine model of asthma was established by sensitization and repeated challenge with ovalbumin (OVA) in female BALB/c mice, followed with oral administration of MSJZT during remission, and then mouse were re-challenged by OVA. The chemical profile of MSJZT was analyzed by high-performance liquid chromatography. The characteristic features of allergic asthma, including airway hyperreactivity, histopathology, cytokine levels (IL-4, -5, -13, -17, and INF-γ), T regulatory (Treg) lymphocytes (Foxp3+CD4+CD25+), and T effector (Teff) lymphocytes (Foxp3-CD25+CD4+) in bronchoalveolar lavage fluid (BALF), and downstream proteins of mTORC1/2 signaling pathway were examined.Results: MSJZT markedly suppressed airway hyper-responsiveness to aerosolized methacholine, and reduced levels of IL-4, IL-5, and IL-13 in the BALF. Histological studies showed that MSJZT significantly reduced inflammatory infiltration in lung tissues. The percentage and absolute number of Teff cells were suppressed to a remarkable level by MSJZT without affecting Treg cells. Furthermore, MSJZT effectively inhibited the mTORC1 activity, but exerted limited effects on mTORC2, as assessed by the phosphorylation of the mTORC1 and mTORC2 substrates, S6 ribosomal protein, p70 S6 kinase, mTOR S2481, and Akt, respectively.Conclusion: MSJZT attenuated chronic airway inflammation in a mouse model of asthma by inhibiting Teff cells, which occurred, at least in part, via modulation of the mTORC1 signaling pathway.

Bu-Shen-Yi-Qi formula ameliorates airway remodeling in murine chronic asthma by modulating airway inflammation and oxidative stress in the lung

Bu-Shen-Yi-Qi formula (BSYQF) could suppress chronic airway inflammation according to previous studies. However, there is relatively little direct experimental evidence to evaluate the effects of BSYQF treatment on airway remodeling in chronic asthma. Recent evidence suggests that oxidative stress is involved in airway inflammation and airway remodeling in chronic asthma. BSYQF which includes various of chemical components having antioxidant effects, could be beneficial in attenuating airway remodeling in chronic asthma. The purpose of this study was to elucidate the effect of BSYQF treatment on airway remodeling and investigate its potential mechanisms in chronic asthma. To develop the murine models of chronic asthma, BALB/c mice were sensitized and challenged to ovalbumin for 8 weeks. BSYQF (5, 10, 20 g raw herbs/kg body weight) or tiotropium bromide (0.1 mM) were administered orally and intranasal instillation, respectively. The effect of BSYQF on pulmonary inflammation and remodeling was evaluated. The parameters of oxidative stress in the lung were analyzed. BSYQF treatment reduced airway hyperresponsiveness (AHR), Th2 response including IL-4, IL-13, and OVA-specific IgE and IgG1, transforming growth factor-β (TGF-β), vascular endothelium growth factor (VEGF), airway inflammation and airway remodeling including smooth muscle thickening and peribronchial collagen deposition. As for oxidative stress, BSYQF treatment reduced reactive oxygen species (ROS), Malondialdehyde (MDA), NO, and the expression of inducible nitric oxide synthase (iNOS), but increased significantly glutathione (GSH) /Oxidized glutathione(GSSH) ratios in the lung, restored mitochondrial ultrastructural changes of bronchial epithelia and ATP levels in the lung.In summary, this study suggested that BSYQF treatment ameliorated airway remodeling and alleviated asthmatic features in chronic asthma models. Anti-inflammatory and antioxidant effect of BSYQF may explain why BSYQF has effects on preventing airway remodeling.

Petiveria alliacea Suppresses Airway Inflammation and Allergen-Specific Th2 Responses in Ovalbumin-Sensitized Murine Model of Asthma.

To examine the effect of metanol extract of Petiveria alliacea (PM) on airway inflflammation in a murine model of chronic asthma. Two-month-old male BALB/c mice (n=6-8/group) were sensitized on days 0 and 14 by intraperitoneal injection of 20 μg ovalbumin (OVA). On day 25, the mice received an airway challenge with OVA (3%, w/v, in phosphate buffered saline). PM was administered orally by oral gavage to mice at doses of 100, 200 and 400 mg/kg body weight once daily from days 18 to 23. Control mice were orally administered phosphate buffered saline (PBS) to induce a model of asthma. At the end of the test, respiratory reactivity was assayed, the total cell number, interleukin-4 (IL-4), IL-5, IL-13, tumor necrosis factor-alpha (TNF-α) and reactive oxygen species (ROS) in the bronchoalveolar lavage fluid (BALF) were determined and the levels of serum IgE, intercellular cell adhesion molecule 1 (ICAM-1) and eotoxin were measured. In addition, lung tissue was used to qualify the IL-4, IL-5, IL-13, TNF-α and transforming growth factor beta 1 (TGF-β1). Histologic examination was performed to observe inflammatory cellular infiltration. The administration of PM in comparison with the OVA-only treated group signifificantly attenuated the infifiltration of eosinophils and other inflflammatory cells (P<0.01). Airway resistance (RI) in the OVA-only induced group was significantly higher than that of the PBS control group (P<0.01) when methacholine was added. TNF-α, IgE, TGF-β1 and cytokine levels IL-4, IL-5, IL-13 in the BALF decreased compared to control mice (P<0.01 or P<0.05). PM treatment also inhibited the production of chemokines, eotaxin and ICAM-1 in BALF (P<0.01), which improved lung function. Histopathological examination revealed that the sensitized treated PM groups had significant lower in inflammatory scores similar to dexamethasone treatments and the untreated group. Administration of PM could inhibit airway inflammation, regulate cytokines, chemokines and enhance pulmonary conditions in allergic murine model of asthma.

Progressive increase in allergen concentration abrogates immune tolerance in ovalbumin-induced murine model of chronic asthma

Persistent inflammation and remodeling of airways are the major hallmarks of asthma. Though airway inflammation diminishes in ovalbumin (OVA)-based mouse model of chronic asthma owing to immune-tolerance linked with repeated allergen exposure, which limits the application of the disease model. Accordingly, the present study was designed to develop a murine model of chronic asthma which presents persistent airway inflammation coupled with remodeling traits. Herein, OVA-sensitized BALB/c mice were challenged with increasing (modified protocol) or constant concentration (conventional protocol) of the allergen for 6 weeks; 3 times/week. The results, indeed, revealed that mice subjected to modified protocol demonstrate an improved response to the allergen as reflected by the significant increase in inflammatory cells particularly, eosinophils in bronchoalveolar lavage fluid compared to conventional protocol. Moreover, the expression of Th2 cytokines and their responsible transcription factors (GATA-3 and STAT-6) was markedly enhanced in lungs. The increase in inflammation was further accompanied by a marked increase in mucus production, collagen deposition, and the expression of allied factors (Muc5ac, Col1α1, and α-SMA). Interestingly, pre-treatment of dexamethasone, a corticosteroid (0.5 mg/kg b.wt., i.p.), suppressed the allergen-induced airway inflammation and mucus production without altering collagen deposition. Failure of dexamethasone seems to be related to their ineffectiveness to modulate the expression of TGF-β, MMP-9, COL1α1, and α-SMA. Overall, our results strongly suggest that mice underwent modified chronic protocol bears more resemblance with asthmatics as it imitates persistent airway inflammation allied with steroid-refractory remodeling traits; hence, may be useful for the evaluation of new/alternative drugs in steroid-refractory asthmatic conditions.

Limethason reduces airway inflammation in a murine model of ovalbumin-induced chronic asthma without causing side effects.

Airway inflammation is the major pathological feature of asthma. Thus, the current therapeutic strategy for asthma is to control inflammation. Limethason, an anti-inflammation drug, is widely used in rheumatoid arthritis treatment. The aim of the present study was to detect the anti-inflammatory effect and side effects of limethason on airways that were sensitized with ovalbumin in a murine model of chronic asthma. In the present study, BALB/c mice were sensitized with ovalbumin. Airway hyperresponsiveness was estimated, and hematoxylin and eosin staining, Periodic acid-Schiff staining and bronchoalveolar lavage were used to detect the effect on chronic asthma. Limethason effectively reduced airway hyperresponsiveness, and inhibited inflammatory cell infiltration and mucus secretion. Bronchoalveolar lavage fluid analysis revealed that limethason suppressed levels of airway eosinophils. In the period of treatment, limethason exhibited no influence on morphology of the femoral head, bone mineral content or bone mineral density, which were detected by histological studies and dual-energy X-ray absorptiometry. The index of liver, spleen, kidney, gastrocnemius and brown adipose tissue also demonstrated that limethason had no adverse effects on organs and tissues. The present study revealed that limethason could effectively reduce inflammation in an asthma mouse model without side effects. Therefore, limethason may have therapeutic potential for treating chronic asthma clinically.

Immuno-modulatory and Therapeutic Effect of Curcumin in an Allergensensitized Murine Model of Chronic Asthma

Background: Asthma is a chronic allergic disease of the lung and airways, characterized by persistent inflammation and airway hyper-responsiveness. More than 200 million people are affected with severe asthma worldwide. T cells, especially Th2 cells, secreting IL-4, IL-5 and IL-13, are pivotal in orchestrating the disease process. We herein investigated the inhibition mechanism of curcumin, a polyphenol present in turmeric, and its ability to alleviate allergic asthma in C57BL/6J mice.Methods: Mice were sensitized and challenged with Ovalbumin for 54 days. We investigated cellular infiltration in blood and BALF, assessed levels of serum IgE, assessed structural changes by histological analysis, and determined the levels of expression of relevant genes and proteins.Results: Our data revealed that curcumin has some anti-inflammatory effect and is successful in ameliorating the disease. We found that curcumin most likely acts by inhibiting the activation of NFκB and its subsequent downstream processes. Our data provided evidence in support of therapeutic application of curcumin in allergic inflammation and airway remodeling.

Sinomenine ameliorates the airway remodelling, apoptosis of airway epithelial cells, and Th2 immune response in a murine model of chronic asthma

BackgroundSinomenine (SIN), an alkaloid isolated from the root of Sinomenium acutum which has a variety of pharmacological effects, including anti-inflammation, immunosuppression and anti-angiogenesis. The present study aimed to evaluate the effects of SIN on airway remodelling, epithelial apoptosis, and T Helper (Th)-2 derived cytokine levels in a murine model of chronic asthma. MethodsTwenty-two BALB/c mice were divided into four groups; I (control), II (placebo), III, IV. Mice in groups III and IV received the SIN (100mg/kg), and dexamethasone (1mg/kg) respectively. Epithelium thickness, sub-epithelial smooth muscle thickness, number of mast and goblet cells of samples isolated from the lung were measured. Immunohistochemical scorings of the lung tissue for matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEG-F), transforming growth factor-beta (TGF-β), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases (caspase)-3 were determined. IL-4, IL-5, IL-13, Nitric oxide in bronchoalveolar lavage fluid (BALF) and ovalbumin-specific immunoglobulin (Ig) E in serum were quantified by standard ELISA protocols. ResultsThe dose of 100mg/kg SIN treatment provided beneficial effects on all of the histopathological findings of airway remodelling compared to placebo (p<0.05). All cytokine levels in BALF and serum and immunohistochemical scores were significantly lower in 100mg/kg SIN treated group compared to the placebo (p<0.05). ConclusionsThese findings suggested that the dose of 100mg/kg SIN improved all histopathological changes of airway remodelling and its beneficial effects might be related to modulating Th-2 derived cytokines and the inhibition of apoptosis of airway epithelial cells.