OVA-treated Mice Research Articles

Different allergen-induced asthma and anaphylaxis show distinctive IgE pathway dependence

BackgroundThe pathogenesis of allergic asthma is classically understood to involve allergens crosslinking Immunoglobulin E (IgE) bound to mast cells, leading to the release of histamine and other inflammatory mediators. ObjectiveThis study aims to explore whether different allergens have distinct IgE-dependent mechanisms in mouse models of both asthma and anaphylaxis. MethodsWild type (WT) and IgE knockout (IgE KO) mice were used to generate asthma mouse models. Lung inflammation was assessed by histological analysis and inflammatory cells in Bronchial Alveolar Lavage Fluids (BALF). Passive Cutaneous Anaphylaxis (PCA) was conducted to quantify IgE, and Toluidine Blue staining was used to visualize mast cell recruitment. ResultsAll allergen-treated mice exhibited significant airway inflammation. Compared to WT mice, HDM-treated IgE KO mice showed an attenuated inflammatory profile, particularly with reduced eosinophils. These mice had lower serum levels of HDM-specific IgE and IgG1 as well as reduced levels of Th2 cytokines interleukin 4 (IL-4) and IL-5 in BALF. CRE-treated IgE KO mice also displayed a reduced inflammation, with significant differences only in eosinophils. Interestingly, no significant differences in airway inflammation were observed between OVA-treated IgE KO mice and WT mice. Furthermore, both HDM and CRE-induced PCA model showed significantly less Evan's blue dye leakage and mast cell recruitment in the ears of IgE KO mice compared to WT mice, with no differences for OVA-induced PCA and mast cell recruitment. ConclusionThe results highlight the variability in IgE pathway dependence among different allergens, emphasizing the need for further research to delineate the underlying mechanisms.

Oral administration of ovalbumin ameliorates specific food allergy via inhibiting gasdermin C-mediated pyroptosis and regulating microbial homeostasis

Early intervention with food allergenic proteins is considered the most promising and effective approach in preventing the onset of food allergy (FA). However, the effects of oral administration of protein antigens from different food sources on specific FA outcomes and its regulatory mechanisms remain largely unclear. Here, the Balb/c mice were treated with 5 mg of egg ovalbumin (OVA) or cow's milk β-lactoglobulin (BLG) for 5 days prior to intraperitoneal sensitization with OVA/Alum and oral challenge with 20 mg OVA. The results indicated that oral administration of both OVA and BLG significantly increased the proportion of regulatory T cells. However, the introduction of OVA, but not the bystander antigen BLG, prevented the occurrence of allergic diarrhea (OT-OVA group: 0% vs OT-BLG group: 100%) and mitigated the decrease in body temperature (OT-OVA group: 0.11 °C vs OT-BLG group: 1.1 °C). Specifically, the levels of serum immunoglobulin-E and mast cell protease-1 were significantly reduced, and the expression of zonula occludens-1, occludin, and claudin-1 was increased in the OVA-treated mice but not BLG-treated mice. Subsequently, transcriptome sequencing and Western blot analysis revealed that oral administration of OVA reduced the expression and cleavage of gasdermin C, which further decreased interleukin-33 secretion. Additionally, the dysregulation of the gut microbiota and short-chain fatty acid metabolism in the intestinal microenvironment caused by FA was reversed in OVA-treated mice but not BLG. In summary, our results presented a unique approach to ameliorate FA through targeting gasdermin C-mediated pyroptosis and dysbiosis of the gut microbiota in the intestinal microenvironment with OVA.

Role of transient receptor potential vanilloid 4 channels in an ovalbumin-induced murine food allergic model.

The prevalence of food allergy (FA) has increased worldwide but an effective therapeutic strategy has not been established. Transient receptor potential vanilloid 4 (TRPV4), a mechanosensitive nonselective cation channel, is mainly expressed in the epithelium of various organs. The present study investigated the role of TRPV4 in the pathogenesis of an ovalbumin (OVA)-induced FA model in mice. Wild-type (WT) and TRPV4-deficient (TRPV4KO) mice were sensitized and challenged by OVA to establish FA model. Intestinal tissue samples were processed for biochemical, molecular, and image analyses. Intestinal permeability and antigen uptake assay were conducted using FITC-dextran and OVA-FITC, respectively. TRPV4 was expressed in the colonic epithelium in normal and OVA-treated WT mice. Repeated oral administration of OVA to mice induced systemic allergic symptoms, diarrhea, upregulation of T helper 2 cytokines, OVA-specific immunoglobulin, and FA-related inflammatory cells. These responses were significantly augmented in TRPV4KO mice compared with WT mice. After the induction of FA, the intestinal permeability was significantly increased in TRPV4KO mice compared with WT mice. The expressions of the tight junction protein occludin and adherence junction protein E-cadherin in the colon were significantly lower in TRPV4KO mice compared with WT mice under normal and FA conditions. In addition, the uptake of OVA by CD11c-positive cells was significantly increased in TRPV4KO mice compared with WT mice under FA conditions. These results suggest that epithelial TRPV4 protects against OVA-induced FA symptoms by suppressing the penetration of allergens by maintaining epithelial barrier functions.

Lipocalin 2 (LCN2) Knockdown Regulates Treg/Th17 Balance to Improve Asthma in Mice.

Asthma substantially affects the quality of life and health of children. Lipocalin 2 (LCN2) is an immune-related protein, which is predicted to be highly expressed in asthma. Here, we investigated the role of LCN2 in ovalbumin (OVA)-induced asthma mouse model. We knocked down LCN2 in an asthma mouse model and performed histopathological analysis using hematoxylin and eosin (H&E) staining assay. Differentiated cells were assessed using Diff-Quick staining assay. We investigated the regulatory T (Treg) cell/ T helper 17 (Th17) cell balance using flow cytometry and enzyme-linked immunosorbent assay (ELISA). Inflammatory factors were measured using quantitative real-time reverse transcription PCR (qRT-PCR). The involved pathways were assessed using Western blotting. LCN2 was upregulated in patients with asthma. OVA promoted pathological deterioration in the lungs, increased IgE levels in the plasma, and elevated the number of differentiated inflammatory cells, whereas LCN2 knockdown abrogated the OVA-induced effects. Additionally, the Treg/Th17 imbalance and increased inflammatory cytokine levels were improved by LCN2 knockdown in OVA-treated mice. Moreover, LCN2 knockdown reversed the activation of the janus kinase (JNK) pathway. LCN2 knockdown improved the Treg/Th17 balance, alleviated inflammation, and inactivated the JNK pathway in OVA-induced asthma mouse model, suggesting that LCN2 may be a novel therapeutic target for asthma in children.

Downregulation of NOX4 improves airway remodeling and inflammation by the TGF-β1-Smad2/3 pathway in asthma.

Asthma is a respiratory inflammatory disease, and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is involved in the progression of respiratory diseases. However, the role of NOX4 in asthma remains unclear. In the present study, we aimed to explore the effects of NOX4 on airway remodeling and inflammation. NOX4 expression was measured using immunocytochemistry (IHC), western blot, and real-time PCR (qPCR). Lung tissues were stained using the H&E assay. ELISA was used to examine the levels of airway remodeling-related indicators, and qPCR was used to detect airway inflammatory factors. The results indicated that NOX4 is highly expressed in lung tissues, bronchoalveolar lavage fluid (BALF), and serum of OVA-treated mice. Inhibition of NOX4 alleviated OVA-induced airway remodeling and inflammation. Similarly, TGF-β1 was also upregulated in BALF and serum OVA-induced mice. Inhibition of TGF-β1 signaling also improved airway remodeling and inflammation induced by OVA. Moreover, the downregulation of NOX4 inactivated the TGF-β1-Smad2/3 pathway, and TGF-β1 decreased Smad2/3 expression. Moreover, inhibition of the TGF-β1 was enhanced, while TGF-β1 reversed the effects on airway remodeling and inflammation induced by NOX4 inhibition. Taken together, the downregulation of NOX4 improves airway remodeling and inflammation via inactivation of the TGF-β1-Smad2/3 pathway in asthma mice, suggesting that NOX4 may be a therapeutic target for asthma.

Attenuated airways inflammation and remodeling in IL-37a and IL-37b transgenic mice with an ovalbumin-induced chronic asthma

BackgroundAsthma is a common chronic respiratory disease characterized by airways inflammation, hyperresponsiveness and remodeling. IL-37, an anti-inflammatory cytokine, consists of five splice isoforms, that is, a-e. Although it has been previously shown that recombinant human IL-37b is able to inhibit airway inflammation and hyperresponsiveness in animal models of asthma, the effects and difference of other IL-37 isoforms, such as IL-37a on features of asthma are unknown. MethodsAnimal models of chronic asthma were established using IL-37a and IL-37b transgenic mice with C57BL/6J background and wild-type (WT) mice sensitized and nasally challenged with ovalbumin (OVA). Airway hyperresponsiveness was measured using FlexiVent apparatus, while histological and immunohistological stainings were employed to measure airways inflammation and remodeling indexes, including goblet cell metaplasia, mucus production, deposition of collagen, hypertrophy of airway smooth muscles and pulmonary angiogenesis. ResultsCompared to WT mice, both IL-37a and IL-37b transgenic mice had significant reduced airway hyperresponsiveness and the declined total numbers of inflammatory cells, predominant eosinophils into airways and lung tissues. Furthermore, all features of airways remodeling, including degrees of mucus expression, collagen deposition, hypertrophy of smooth muscles, thickness of airways and neovascularization markedly decreased in IL-37 transgenic mice compared with OVA-treated WT mice. ConclusionOur data suggest that both IL-37a and IL-37b isoforms are able to not only ameliorate airways inflammation and airways hyperresponsiveness, but also greatly reduce airways structural changes of animal models of chronic asthma.

Myeloid-associated differentiation marker is associated with type 2 asthma and is upregulated by human rhinovirus infection.

Human rhinoviruses are known to predispose infants to asthma development during childhood and are often associated with exacerbations in asthma patients. MYADM epithelial expression has been shown to associate with asthma severity. The goal of this study was to determine if MYADM expression patterns were altered in asthma and/or rhinovirus infection and if increased MYADM expression is associated with increased asthma-associated factors. Utilizing H1HeLa cells and differentiated primary human airway epithelial cells (AECs), we measured the expression of MYADM and inflammatory genes by qRT-PCR in the presence or absence of RV-1B infection or poly I:C treatment and with siRNA knockdown of MYADM. Expression of MYADM in the asthmatic lung was determined in the ovalbumin (ova)-challenged murine model. MYADM expression was upregulated in the lungs from ova-treated mice and in particular on the subsurface vesicle membrane in airway epithelial cells. Upon infection with RV-1B, human AECs grown at an air-liquid interface had increased the MYADM expression predominantly detected in ciliated cells. We found that the presence of MYADM was required for expression of several inflammatory genes both in a resting state and after RV-1B or poly I:C treatments. Our studies show that in a mouse model of asthma and during RV-1B infection of primary human AECs, increased MYADM expression is observed. In the mouse model of asthma, MYADM expression was predominantly on the luminal side of airway epithelial cells. Additionally, MYADM expression was strongly associated with increases in inflammatory genes, which may contribute to more severe asthma and RV-linked asthma exacerbations.

Leptin/obR signaling exacerbates obesity-related neutrophilic airway inflammation through inflammatory M1 macrophages

BackgroundObesity-related asthma is a kind of nonallergic asthma with excessive neutrophil infiltration in the airways. However, the underlying mechanisms have been poorly elucidated. Among the adipokines related to obesity, leptin is related to the inflammatory response. However, little is understood about how leptin acts on the leptin receptor (obR) in neutrophilic airway inflammation in obesity-associated asthma. We explored the inflammatory effects of leptin/obR signaling in an obesity-related neutrophilic airway inflammation mouse model.MethodsWe established a neutrophilic airway inflammation mouse model using lipopolysaccharide (LPS)/ovalbumin (OVA) sensitization and OVA challenge (LPS + OVA/OVA) in lean, obese, or db/db (obR deficiency) female mice. Histopathological, bronchoalveolar lavage fluid (BALF) inflammatory cell, and lung inflammatory cytokine analyses were used to analyze airway inflammation severity. Western blotting, flow cytometry, reverse transcription‐polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay (ELISA) were used to evaluate the underlying mechanisms. In vitro bone marrow‐derived macrophage (BMDM) and bone marrow-derived neutrophil experiments were performed.ResultsWe found that the serum leptin level was higher in obese than in lean female mice. Compared to LPS/OVA + OVA-treated lean female mice, LPS/OVA + OVA-treated obese female mice had higher peribronchial inflammation levels, neutrophil counts, Th1/Th17-related inflammatory cytokine levels, M1 macrophage polarization levels, and long isoform obR activation, which could be decreased by the obR blockade (Allo-Aca) or obR deficiency, suggesting a critical role of leptin/obR signaling in the pathogenesis of obesity-related neutrophilic airway inflammation in female mice. In in vitro experiments, leptin synergized with LPS/IFN-γ to promote the phosphorylation of the long isoform obR and JNK/STAT3/AKT signaling pathway members to increase M1 macrophage polarization, which was reversed by Allo-Aca. Moreover, leptin/obR-mediated M1 macrophage activity significantly elevated CXCL2 production and neutrophil recruitment by regulating the JNK/STAT3/AKT pathways. In clinical studies, obese patients with asthma had higher serum leptin levels and M1 macrophage polarization levels in induced sputum than non-obese patients with asthma. Serum leptin levels were positively correlated with M1 macrophage polarization levels in patients with asthma.ConclusionsOur results demonstrate leptin/obR signaling plays an important role in the pathogenesis of obesity-related neutrophilic airway inflammation in females by promoting M1 macrophage polarization.Graphical abstract

Protective effects of aloin on asthmatic mice by activating Nrf2/HO-1 pathway and inhibiting TGF-β/Smad2/3 pathway.

Asthma is a severe chronic respiratory disease affecting all age groups with increasing prevalence. Anti-inflammatory strategies are promising options for the treatment of asthma. Although the inhibitory effect of aloin on inflammation has been demonstrated in various diseases, its effect on asthma remains unknown. A mice asthma model was established by treating with ovalbumin (OVA). The effects and mechanism of aloin on the OVA-treated mice were determined by enzyme-linked--immunosorbent serologic assay, biochemical examination, hematoxylin and eosin and Masson's staining, and Western blot assay. OVA treatment in mice significantly increased the number of total cells, neutrophils, eosinophils, and macrophages and the concentration of interleukin (IL)-4, IL-5, and IL-13, which were attenuated with the administration of aloin. The content of malondialdehyde was enhanced in OVA-treated mice, with the decreased levels of superoxide dismutase and glutathione, which were reversed with aloin treatment. Aloin treatment reduced the airway resistance of OVA-induced mice. The inflammatory cell infiltration around small airways was accompanied by the thickening and contraction of bronchial walls and pulmonary collagen deposition in OVA-treated mice; however, these conditions were ameliorated with aloin treatment. Mechanically, aloin upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)-heme oxygenase 1 (HO-1) pathway but inhibited the level of transforming growth factor beta-SMAD2/3 genes (TGF-β/Smad2/3) axis in OVA-induced mice. Aloin treatment lessened airway hyperresponsiveness, airway remodeling, inflammation, and oxidative stress in OVA-treated mice, and was closely related to the activation of Nrf2/HO-1 pathway and the weakening of TGF-β/Smad2/3 pathway.

Ablation of CD226 on CD4+ T cells modulates asthma progress associated with altered IL-10 response and gut microbiota.

To investigate the role of the costimulatory molecule CD226 in asthma pathogenesis, we produced a CD4+ T-cell-specific CD226 knockout mice model (Cd226ΔCD4) and induced airway allergic inflammation by administering ovalbumin (OVA). Our results revealed alleviated lung inflammation, decreased levels of OVA-specific IgE, and increased levels of IL-10 in the serum of Cd226ΔCD4 mice (P<0.05). Moreover, IL-10 levels in CD4+ T cells were significantly elevated in the mediastinal lymph node, spleen, and Peyer's patches in the Cd226ΔCD4 mice compared with those in controls (P<0.05 to P<0.01). Notably, there was a significantly higher IL-10 mRNA levels in the large intestine of the mice (P<0.05). The protective effect of CD226 deficiency is also associated with the accumulation of gut TCRγδ+ intraepithelial lymphocytes and reversion of the gut microbiome dysbiosis. The Bacteroidetes-to-Firmicutes ratio and the abundance of Akkermansia increased in the absence of CD226 after OVA treatment. Our data reveal the synchronous changes in the lung and intestine in OVA-treated CD226-knockout mice, supporting the gut-lung axis concept and providing evidence for novel therapeutic approaches for asthma.

Transient Receptor Potential Channel Vanilloid 1 Contributes to Facial Mechanical Hypersensitivity in a Mouse Model of Atopic Asthma

Sensitive skin, a common pathophysiological feature of allergic diseases, is defined as an unpleasant sensation in response to stimuli that normally should not provoke such sensations. However, the relationship between allergic inflammation and hypersensitive skin in the trigeminal system remains to be elucidated. To explore whether bronchial allergic inflammation affects facial skin and primary sensory neurons, we used an ovalbumin (OVA)–induced asthma mouse model. Significant mechanical hypersensitivity was observed in the facial skin of mice with pulmonary inflammation induced by OVA sensitization compared to mice treated with adjuvant or vehicle as controls. The skin of OVA-treated mice showed an increased number of nerve fibers, especially rich intraepithelial nerves, compared to controls. Transient receptor potential channel vanilloid 1 (TRPV1)–immunoreactive nerves were enriched in the skin of OVA-treated mice. Moreover, epithelial TRPV1 expression was higher in OVA-treated mice than in controls. Trigeminal ganglia of OVA-treated mice displayed larger numbers of activated microglia/macrophages and satellite glia. In addition, more TRPV1 immunoreactive neurons were found in the trigeminal ganglia of OVA-treated mice than in controls. Mechanical hypersensitivity was suppressed in OVA-treated Trpv1-deficient mice, while topical skin application of a TRPV1 antagonist before behavioral testing reduced the reaction induced by mechanical stimulation. Our findings reveal that mice with allergic inflammation of the bronchi had mechanical hypersensitivity in the facial skin that may have resulted from TRPV1-mediated neuronal plasticity and glial activation in the trigeminal ganglion.

Collagen Triple Helix Repeat Containing 1 Deficiency Protects Against Airway Remodeling and Inflammation in Asthma Models In Vivo and In Vitro.

Asthma is a chronic inflammatory disease characterized by airway remodeling and lung inflammation. Collagen triple helix repeat containing 1 (CTHRC1), a glycoprotein, is involved in multiple pathological processes, including inflammation and fibrosis. However, the function of CTHRC1 in asthma remains unclear. In the present study, the mouse asthma model was successfully generated by sensitizing and challenging mice with ovalbumin (OVA). CTHRC1 expression at both RNA and protein levels was significantly upregulated in lung tissues of asthmatic mice. Asthmatic mice exhibited significant airway remodeling as evidenced by increased bronchial wall and smooth muscle cell layer thickness, goblet cell hyperplasia and collagen deposition, and epithelial-mesenchymal transition (EMT), but those characteristics were reversed by CTHRC1 silencing. The cell model with transforming growth factor-β1 (TGF-β1) induction in bronchial epithelial cells (BEAS-2B) was conducted to verify the effects of CTHRC1 on EMT, a classic mechanism that mediates airway remodeling. The results showed that TGF-β1 stimulation increased CTHRC1 expression, and CTHRC1 knockdown inhibited TGF-β1-induced EMT. OVA-treated mice also showed increased inflammatory cell infiltration and the production of OVA-specific immunoglobulin E (IgE), interleukin (IL)-4, IL-5, and IL-13, which were decreased by CTHRC1 downregulation. The effects of CTHRC1 on OVA-induced airway inflammation were further determined by treating BEAS-2B cells with IL-13, in which CTHRC1 knockdown reduced the IL-13-induced secretion of pro-inflammatory factors, including IL-4 and IL-5. In conclusion, these results indicate that CTHRC1 silencing attenuates asthmatic airway remodeling and inflammation in vivo and in vitro, suggesting that CTHRC1 may be a potential target for asthma treatment.

Chryseriol attenuates the progression of OVA-induced asthma in mice through NF-κκB/HIF-1αα and MAPK/STAT1 pathways

Asthma is a hackneyed chronic inflammatory disease of the airway. Chryseriol (CSR) is a kind of flavonoid, and has the effect of bronchiectasis, indicating its potential application for treating respiratory diseases. However, the functions of CSR in asthma have not been reported till now. The histopathologic changes of the lung tissues were assessed by hematoxylin and eosin staining. The cell apoptosis was identified through terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. Total numbers of eosinophils, neutrophils, and macrophages were assessed under microscope. The levels of interleukin (IL)-1β, IL-4, IL-5, and IL-13 were detected by enzyme-linked-immunosorbent serologic assay. The airway hyper-responsiveness (AHR) was evaluated by the whole body plethysmography. The levels of methane dicarboxylic aldehyde, superoxide dismutase, glutathione S-transferase, and glutathione in lung homogenates were confirmed by using corresponding commercial kits. The protein expressions were examined by Western blot analysis. The ovalbumin (OVA) was utilized to establish asthma mouse model. At first, it was revealed that CSR treatment reduced lung injury in OVA-stimulated mice. Moreover, cell apoptosis was enhanced after OVA stimulation but was attenuated by CSR treatment. In addition, CSR treatment decreased the infiltration of inflammatory cells and the production of inflammatory factors in OVA-treated mice. Further investigations demonstrated that CSR treatment relieved AHR in OVA-stimulated mice. The oxidative stress was strengthened in OVA-treated mice, but these effects were relieved by CSR treatment. Lastly, it was discovered that CSR treatment retarded nuclear factor kappa B (NF-κB)/hypoxia-inducible factor 1 alpha (HIF-1α) and p38 mitogen-activated protein kinase (MAPK)/signal transducer and activator of transcription 1 (STAT1) pathways in OVA-triggered asthma mice. Our findings proved that CSR attenuated the progression of OVA-induced asthma in mice through inhibiting NF-κB/HIF-1α and MAPK/STAT1 pathways. This work might highlight the functions of CSR in the treatment of asthma.

Korean Red Ginseng Ameliorates Allergic Asthma through Reduction of Lung Inflammation and Oxidation.

Six-year-old red ginseng, which is processed from the whole ginseng root via steaming and drying, has been shown to have preventive effects such as antioxidative, anti-inflammatory, and immunomodulatory. In this study, we evaluated the therapeutic effects of Korean red ginseng (KRG) against ovalbumin (OVA)-induced allergic asthma and the underlying mechanisms involved. We injected 20 µg of OVA on days 0 and 14, and mice were challenged with aerosolized OVA via a nebulizer for 1 h on days 21, 22, and 23. KRG was administered at 100 and 300 mg/kg from days 18 to 23. The KRG-treated mice showed significant reductions in their airway hyperresponsiveness, production of reactive oxygen species (ROS), and the number of inflammatory cells compared with the OVA-treated mice. The levels of type 2 cytokines in the bronchoalveolar lavage fluid and expression of OVA-specific immunoglobulin E in the serum, which were elevated in the OVA group, were reduced in the KRG-treated groups. The pro-inflammatory factors, inducible nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells, were downregulated by the KRG administration in a dose-dependent manner. KRG effectively suppressed the inflammatory response by inhibiting ROS production. Our results suggest that KRG may have the potential to alleviate asthma.

Zizania latifolia and Its Major Compound Tricin Regulate Immune Responses in OVA-Treated Mice.

Tricin, a flavone belonging to the Gramineae family, has been confirmed to be the primary compound in a Zizania latifolia extract (ZLE) that prevents allergies. Various allergic reactions occur because of the unbalanced differentiation of T help cells (Th) and the consequent overproduction of IgE. Therefore, the regulation of Th1 and Th2 responses by T helper cell differentiation is essential for suppressing allergic responses. This study confirmed the immunomodulatory effects of ZLE and the major compound tricin in an OVA-sensitized mouse model. The IgE and OVA-specific production of tricin and ZLE in plasma were investigated in OVA-sensitized mice. The effects of tricin and ZLE on the amount of Th1 and Th2 cytokines and transcription factors released in splenocytes were investigated in OVA-sensitized mice. The skin roughness and the number of mast cells were confirmed by staining the skin surface with H&E and toluidine blue. Tricin and ZLE reduced the plasma IgE and OVA-specific-IgE levels significantly compared to the OVA group. On the other hand, tricin and ZLE promoted the release of the Th1 cytokines IL-12 and IFN-γ and inhibited the release of Th2 cytokines (IL-4, -10, -13, and -5) in OVA-sensitized mice. Tricin and ZLE induced T-bet and NFATc2 expression, and-down regulated GATA-3 levels. The skin roughness and the number of mast cells decreased in the OVA-immunized mice. Overall, the data indicate that tricin and ZLE may prevent allergy-related diseases through immunomodulation.

Amelioration of Ovalbumin-Induced Allergic Asthma by Juglans regia via Downregulation of Inflammatory Cytokines and Upregulation of Aquaporin-1 and Aquaporin-5 in Mice.

Juglans regia (J. regia) has been used traditionally to treat cough and asthma. The present study evaluates the immunomodulatory and anti-inflammatory potential of J. regia against ovalbumin (OVA)-induced allergic asthma. Intraperitoneal sensitization proceeded by intranasal challenge with OVA was used to induce allergic asthma. BALB/c mice were treated with methanol, n-hexane, and ethyl acetate extracts of J. regia and methylprednisolone one week after 2nd sensitization with OVA and continued for 7 days. mRNA expression levels of IL-4, IL-5, IL-13, AQP-1, AQP-5 TNF-α, TGF-β, and NF-kB were determined using reverse transcription polymerase chain reaction. Hematoxylin and eosin, and periodic acidic-Schiff stains were used for histopathological studies of lung tissues. The data presented all three extracts of J. regia significantly ameliorated airway inflammation by reducing expression levels of IL-4, IL-5, and IL-13 and TNF-α in OVA-treated mice. The suppression of goblet cells hyperplasia and inflammatory cells infiltration by J. regia involved low TGF-β and NF-kB levels. Pretreatment with J. regia also increased the AQP-1 and AQP-5 expression levels in mice treated with OVA. This study supported the traditional use of J. regia and proposed that J. regia ameliorated allergic asthma by suppression of proinflammatory cytokines and elevation of AQP-1 and AQP-5 expression levels.

The Ability of Resveratrol to Attenuate Ovalbumin-Mediated Allergic Asthma Is Associated With Changes in Microbiota Involving the Gut-Lung Axis, Enhanced Barrier Function and Decreased Inflammation in the Lungs.

Asthma is a chronic respiratory disease highly prevalent worldwide. Recent studies have suggested a role for microbiome-associated gut–lung axis in asthma development. In the current study, we investigated if Resveratrol (RES), a plant-based polyphenol, can attenuate ovalbumin (OVA)-induced murine allergic asthma, and if so, the role of microbiome in the gut–lung axis in this process. We found that RES attenuated allergic asthma with significant improvements in pulmonary functions in OVA-exposed mice when tested using plethysmography for frequency (F), mean volume (MV), specific airway resistance (sRaw), and delay time(dT). RES treatment also suppressed inflammatory cytokines in the lungs. RES modulated lung microbiota and caused an abundance of Akkermansia muciniphila accompanied by a reduction of LPS biosynthesis in OVA-treated mice. Furthermore, RES also altered gut microbiota and induced enrichment of Bacteroides acidifaciens significantly in the colon accompanied by an increase in butyric acid concentration in the colonic contents from OVA-treated mice. Additionally, RES caused significant increases in tight junction proteins and decreased mucin (Muc5ac) in the pulmonary epithelium of OVA-treated mice. Our results demonstrated that RES may attenuate asthma by inducing beneficial microbiota in the gut-lung axis and through the promotion of normal barrier functions of the lung.

Qufeng Xuanbi Formula Ameliorates Airway Remodeling in Asthmatic Mice by Suppressing Airway Smooth Muscle Cell Proliferation through MEK/ERK Signaling Pathway.

Asthma is a common chronic respiratory disease. The Qufeng Xuanbi formula (QFXBF), a Chinese herbal decoction, has shown efficacy in the management of asthma. The purpose of this study was to investigate the potential therapeutic effects of QFXBF in the treatment of asthma both in vitro and in vivo. Platelet-derived growth factor (PDGF)-induced airway smooth muscle cell (ASMC) proliferation and MTT assays were used to explore the effects of QFXBF on the proliferation of ASMCs. Moreover, 40 female BALB/c mice were randomly divided into five groups: control group, ovalbumin (OVA) group, high QFXBF group, low QFXBF group, and dexamethasone (DEX) group (n = 8 per group). A mouse allergic asthma model was established using the intranasally administered OVA sensitization method. Morphological changes in the lung tissue were examined by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. Finally, the protein expression of alpha-smooth muscle actin (α-SMA), proliferating cell nuclear antigen (PCNA), phospho-mitogen-activated protein kinase (p-MEK1/2), mitogen-activated protein kinase (MEK1/2), phospho-extracellular signal-regulated kinases (p-ERK1/2), and extracellular signal-regulated kinases (ERK1/2) in ASMCs and lung tissue were determined by western blotting and immunofluorescent staining assays. PDGF significantly increased the viability of ASMCs. Compared with mice in the control group, the airway walls and airway smooth muscle of mice in the OVA group were thickened, and the number of inflammatory cells around the bronchus significantly increased. Moreover, the administration of QFXBF markedly inhibited the proliferation of ASMCs and alleviated the pathological changes induced by OVA. Furthermore, the protein expressions of p-ERK1/2, p-MEK1/2, PCNA, and α-SMA were significantly increased in OVA-treated mice and PDGF-treated ASMCs. Finally, treatment with QFXBF also significantly decreased the protein expression of p-ERK1/2, p-MEK1/2, α-SMA, and PCNA. QFXBF inhibited the proliferation of ASMCs by suppressing MEK/ERK signaling in PDGF-induced ASMCs and OVA-induced mice.

Salidroside Attenuates Airway Inflammation and Remodeling via the miR-323-3p/SOCS5 Axis in Asthmatic Mice

Introduction: Salidroside (Sal) a bioactive component extracted from Rhodiola rosea is remarkable for its anti-asthmatic effects. The study aimed to explore the molecular mechanism of Sal in airway inflammation and remodeling in asthmatic mice and provide a novel theoretical basis for asthma treatment. Methods: An asthmatic mouse model was established via ovalbumin (OVA) treatment, followed by injection of Sal and transfection of miR-323-3p-mimic and sh- suppressor of cytokine signaling 5 (SOCS5). Expressions of miR-323-3p, SOCS5 mRNA, collagen (COL)-I, and COL-III were detected via reverse transcription quantitative polymerase chain reaction. SOCS5 protein level was detected via Western blot. Levels of IgE, IL-13, IL-4, and IL-5 were detected via enzyme-linked immunosorbent assay. Inflammatory cell infiltration was observed via hematoxylin-eosin staining. Collagen disposition was observed via Masson staining. Resistance index (RI) of airway hyperresponsiveness, and the number of total cells, inflammatory cells (eosinophil, macrophage, neutrophil, and lymphocyte) in bronchoalveolar lavage fluid (BALF) were observed. The binding relationship between miR-323-3p and SOCS5 was predicted through the RNA22 website and verified via dual-luciferase reporter assay. Results: miR-323-3p was highly expressed in OVA-treated mice. Sal treatment reduced inflammatory cell infiltration, COL disposition, miR-323-3p expression, and IgE, IL-13, IL-4, IL-5, COL-I, and COL-III levels, RI value, and the number of total cells and inflammatory cells in BALF. miR-323-3p inhibited SOCS5 transcription. miR-323-3p overexpression or SOCS5 downregulation reversed the protecting role of Sal in asthmatic mice. Conclusion: Sal inhibited miR-323-3p expression to promote SOCS5 transcription, thereby attenuating airway inflammation and remodeling in asthmatic mice.

Impact of dietary exposure to low-dose tris(1,3-dichloro-2-propyl)phosphate in allergic asthmatic mice

Objective Tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) is an organophosphorus flame retardant that is an alternative to brominated flame retardants. Although TDCIPP can adversely affect human health, information about its effects on immune and allergic responses is scarce. We aimed to investigate the effects of dietary exposure to TDCIPP using less than the human tolerable daily intake (TDI) in allergic asthmatic mice. Methods Male C3H/HeJSlc mice were fed a chow diet containing TDCIPP equivalent to 0.02 μg/kg/day (low; L), 0.2 μg/kg/day (medium; M), or 2 μg/kg/day (high; H) and were intratracheally administered ovalbumin (OVA, 1 μg/animal) every 2 weeks from 5 to 11 weeks of age. Results In OVA-treated mice, TDCIPP-H exposure tended to enhance pulmonary inflammation compared with vehicle exposure. TDCIPP dose-dependently decreased mRNA level of G protein-coupled estrogen receptor (GPER) in the lungs with or without OVA. OVA + TDCIPP-H treatment tended to increase the total cell number and promoted CD4+ cell activation compared with OVA alone treatment in mediastinal lymph nodes. In splenocytes, an increase in the fraction of Breg cells, but not of total B and T cells, and an increase in IL-5 in cell culture supernatants following OVA re-stimulation in OVA + TDCIPP-H-treated mice was observed compared with OVA-alone-treated mice. Moreover, OVA + TDCIPP-H exposure decreased Gr-1 expression in bone marrow (BM) cells. Discussion These results suggested that dietary exposure to TDCIPP at TDI level slightly enhances allergic diseases, such as allergic asthma, via GPER regulation at inflamed sites and secondary lymphoid tissue and BM cell alternations.