Airway Hyperresponsiveness In Asthmatic Mice Research Articles

Demethylzeylasteral (T-96) Alleviates Allergic Asthma via Inhibiting MAPK/ERK and NF-κB Pathway

Introduction: Demethylzeylasteral (T-96), a new extract of Tripterygium wilfordii Hook F, exerted immunomodulatory properties in autoimmune diseases, but its effect on airway inflammatory diseases remains unclear. Our study aims to explore the protective effect and underlying mechanism of T-96 in allergic asthma. Methods: The OVA-induced asthmatic mice were administered by gavage with T-96 (0.1 mg/10 g, 0.3 mg/10 g, or 0.6 mg/10 g) 1 h before each challenge. The airway hyperresponsiveness was assessed, pathological changes were evaluated by HE and PAS staining, and expressions of Th2 cytokines were determined by PCR and ELISA. The activation of MAPK/ERK and NF-κB pathway was assessed by western blot. Results: T-96 significantly relieved airway hyperresponsiveness in asthmatic mice, evidenced by reduced airway resistance (Raw) and increased lung compliance dynamic compliance (Cdyn). Also, enhanced inflammatory infiltration and mucus hypersecretion were ameliorated in lungs of asthmatic mice following increasing doses of T-96 treatment, accompanied by decreased eosinophils in bronchoalveolar lavage fluid (BALF), IgE and OVA-specific IgE levels in serum, and downregulated IL-5 and IL-13 expressions in BALF and lung tissues as well. Notably, phosphorylation levels of p38 MAPK, ERK, and p65 NF-κB were obviously increased in asthmatic mice compared with the control group, which were then abrogated upon T-96 treatment. Conclusion: This study first revealed that T-96 alleviated allergic airway inflammation and airway hyperresponsiveness via inhibiting MAPK/ERK and NF-κB pathway. Thus, T-96 could potentially act as a new anti-inflammatory agent in allergic asthma.

Effects of increasing sensitizing doses of ovalbumin on airway hyperresponsiveness in asthmatic mice.

The dosage of ovalbumin (OVA) during the sensitization stage is considered a crucial factor in the development of airway hyperresponsiveness (AHR). However, the inconsistent dosages of sensitizing OVA used in current studies and the lack of research on their impact on AHR are notable limitations. We examined the impact of increasing sensitizing doses of OVA in a murine asthma model, which entailed initial sensitization with OVA followed by repeated exposure to OVA aerosols. BALB/c mice were primed with doses of OVA (0, 10, 20, 50, and 100 μg) plus 1 mg Alum on Days 0 and 7, and were challenged with OVA aerosols (10 mg/mL for 30 min) between Days 14 and 17. Antigen-induced AHR to methacholine (MCh), as well as histological changes, eosinophilic infiltration, and epithelial injury were assessed. The result indicated that there are striking OVA dose-related differences in antigen-induced AHR to MCh. The most intense antigen-induced AHR to MCh was observed with sensitization at 50 μg, while weaker responses were seen at 10, 20, and 100 μg. Meanwhile, there was a significant increase in eosinophil count with sensitization at 50 μg. The changes of AHR were correlated with total cells count, lymphocytes count, eosinophils count, and basophils count in bronchoalveolar lavage fluid; however, it did not correlate with histological changes such as cellular infiltration into bronchovascular bundles and goblet cell hyperplasia of the bronchial epithelium. Overall, this study demonstrated that sensitization with 50 μg of OVA resulted in the most significant AHR compared to other dosages. These findings may offer valuable insights for future research on mouse asthma modeling protocols.

Mycobacterium vaccae alleviates allergic airway inflammation and airway hyper-responsiveness in asthmatic mice by altering intestinal microbiota.

Host immunity can influence the composition of the gut microbiota and consequently affect disease progression. Previously, we reported that a Mycobacterium vaccae vaccine could ameliorate allergic inflammation in asthmatic mice by regulating inflammatory immune processes. Here, we investigated the anti-inflammatory effects of M. vaccae on allergic asthma via gut microbiota modulation. An ovalbumin (OVA)-induced asthmatic murine model was established and treated with M. vaccae. Gut microbiota profiles were determined in 18 BALB/c mice using 16S rDNA gene sequencing and metabolomic profiling was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. Mycobacterium vaccae alleviated airway hyper-reactivity and inflammatory infiltration in mice with OVA-induced allergic asthma. The microbiota of asthmatic mice is disrupted and that this can be reversed with M. vaccae. Additionally, a total of 24 differential metabolites were screened, and the abundance of PI(14:1(9Z)/18:0), a glycerophospholipid, was found to be correlated with macrophage numbers (r = 0.52, p = 0.039). These metabolites may affect chemokine (such as macrophage chemoattractant protein-1) concentrations in the serum, and ultimately affect pulmonary macrophage recruitment. Our data demonstrated that M. vaccae might alleviate airway inflammation and hyper-responsiveness in asthmatic mice by reversing imbalances in gut microbiota. These novel mechanistic insights are expected to pave the way for novel asthma therapeutic strategies.

IL-27 Alleviates Airway Inflammation and Airway Hyperresponsiveness in Asthmatic Mice by Targeting the CD39/ATP Axis of Dendritic Cells

Interleukin-27 receptor (IL-27R) is expressed in a variety of immune cells and structural cells, including dendritic cells. The mechanism of IL-27 in asthma has not been fully elucidated. This study aimed to examine whether IL-27 regulated the CD39/ATP axis of dendritic cells in asthma. Our results showed that in ovalbumin (OVA)-induced asthma mouse model, IL-27Rα−/− asthmatic mice showed increased airway resistance, increased infiltration of inflammatory cells in lung tissue, proliferation of goblet cells, enhanced expression of Muc5 AC around airway epithelium, increased total number of cells and eosinophils, increased levels of total IgE, OVA-IgE, IL-4, IL-5, IL-13 and IL-17 A, and increased expression of transcription factors GATA-3 and RORγt in lung tissue. The expression of CD39 mRNA and protein in the lung tissue of IL-27Rα−/− asthmatic mice decreased, and the expression of NLRP3, ASC and Caspase-1 in NLRP3 inflammasome components increased. The concentration of ATP was significantly increased compared with WT asthmatic mice. In vitro experiments showed that the expression of CD39 in lung dendritic cells of IL-27Rα−/− asthmatic mice decreased, while the expression of NLRP3 inflammasome components NLRP3, ASC and Caspase-1 increased. These findings indicate that IL-27 directly and indirectly regulates immunoinflammatory responses in asthma by acting on dendritic cells CD39/ATP Axis.

Quercetin Alleviates Asthma-Induced Airway Inflammation and Remodeling through Downregulating Periostin via Blocking TGF‐β1/Smad Pathway

Introduction: The aim of the study was to discuss whether the anti-asthmatic effect of quercetin is related to periostin and the downstream molecular pathway of quercetin’s anti-asthmatic effect. Methods: We constructed asthmatic mice, sensitized by ovalbumin, and administrated different treatments into mice according to the experimental design. In this study, we mainly observed the inflammatory response, airway fibrosis, and airway hyperresponsiveness in asthmatic mice. Pathological stains (H&E, PAS, and Masson) were performed. We also detected the inflammation factors and fibrosis-related cytokines by enzyme-linked immunosorbent serologic assay. In addition, we also explored the level of periostin by enzyme-linked immunosorbent serologic assay and Western blot. At the same time, TGF‐β1/Smad pathway was also determined by Western blot. Results: A high expression of periostin was found in asthmatic mice, and quercetin decreases periostin content in bronchoalveolar lavage fluid. Quercetin and OC-20 inhibit airway inflammation response, airway fibrosis, and airway hyperreactivity. Quercetin downregulated TGF‐β1/Smad pathway in the lung tissues of asthmatic mice. Anti-asthma role of quercetin is related to periostin. Then deeper mechanical study revealed that inhibiting TGF-β1 could improve asthmatic symptoms, and quercetin exerted the protective effect on asthmatic mice through inhibition of TGF‐β1/Smad pathway. Conclusion: Quercetin provided a protective role against asthma via periostin, manifested by mild inflammatory infiltration, reduced goblet cell proliferation, and reduced airway fibrosis. TGF‐β1/Smad pathway is an important transduction system, participating in the protective effect of quercetin on asthma.

Evaluation of You-Gui-Wan critical compounds inhibiting ALOX-5 and HDC gene expression in RBL-2H3 cells using a fractional factorial design

Ethnopharmacological relevanceThe traditional Chinese medicine (TCM) You-Gui-Wan (YGW) has been used to treat asthma for hundreds of years. Aim of the studyYGW is composed of 10 types of medicinal materials. However, the immune mechanism of YGW in asthma treatment has not been elucidated. Therefore, this study investigated asthma symptoms attenuated by YGW and the underlying immune regulatory mechanism. Materials and methodsIntratracheal (i.t.) stimulation of BALB/c mice with Dermatophagoides pteronyssinus (Der p) was performed once per week (40 μL, 2.5 μg/μL). For six consecutive weeks, different doses of YGW (0.2 g/kg and 0.5 g/kg) were orally administered 30 min before stimulation with Der p. After the last stimulation, airway hyperreactivity, lung gene expression, and total immunoglobulin E (IgE) in blood were evaluated using a whole-body plethysmograph system, real-time PCR, and ELISA, respectively. In addition, DNP-IgE/DNP-BSA was added to stimulate mast cells (RBL-2H3), and YGW or various compound compositions (Trial) were added to RBL-2H3 cells for 30 min to evaluate the effects of the drug on mast cell degranulation and on gene expression. JMP 5.1 software was used to design and analyze YGW's critical compounds by which it inhibited ALOX-5 and HDC gene expression in RBL-2H3 cells. ResultsYGW significantly decreased serum total IgE levels and airway hyperresponsiveness in asthmatic mice. YGW also reduced the gene expression of IL-6, TNF-α, IL-4, IL-13, and COX-2 in the lungs of asthmatic mice and RBL-2H3 cells. YGW and the compound (Trial 21) present in YGW inhibited the gene expression of ALOX-5 and HDC in RBL-2H3 cells. ConclusionThe experimental results indicate that YGW exhibits anti-airway hyperresponsiveness and specific immunomodulatory effects. In addition, YGW synergistically inhibits ALOX-5 and HDC gene expression in mast cells through a combination of 21 compounds, including luteolin, quercetin, and β-carotene.

Fisetin Suppresses the Inflammatory Response and Oxidative Stress in Bronchial Epithelial Cells.

Fisetin is isolated from many fruits and vegetables and has been confirmed to improve airway hyperresponsiveness in asthmatic mice. However, whether fisetin reduces inflammatory response and oxidative stress in bronchial epithelial cells is unclear. Here, BEAS-2B human bronchial epithelial cells were treated with various concentrations of fisetin and then stimulated with tumor necrosis factor-α (TNF-α) or TNF-α/interleukin-4. In addition, ovalbumin-sensitized mice were treated with fisetin to detect inflammatory mediators and oxidative stress expression. Fisetin significantly reduced the levels of inflammatory cytokines and chemokines in TNF-α-stimulated BEAS-2B cells. Fisetin also attenuated intercellular adhesion molecule-1 expression in TNF-α-stimulated BEAS-2B cells, suppressing THP-1 monocyte adhesion. Furthermore, fisetin significantly suppressed airway hyperresponsiveness in the lungs and decreased eosinophil numbers in the bronchoalveolar lavage fluid of asthmatic mice. Fisetin decreased cyclooxygenase-2 expression, promoted glutathione levels, and decreased malondialdehyde levels in the lungs of asthmatic mice. Our findings indicate that fisetin is a potential immunomodulator that can improve the pathological features of asthma by decreasing oxidative stress and inflammation.

STIM1 is a core trigger of airway smooth muscle remodeling and hyperresponsiveness in asthma

Airway remodeling and airway hyperresponsiveness are central drivers of asthma severity. Airway remodeling is a structural change involving the dedifferentiation of airway smooth muscle (ASM) cells from a quiescent to a proliferative and secretory phenotype. Here, we show up-regulation of the endoplasmic reticulum Ca2+ sensor stromal-interacting molecule 1 (STIM1) in ASM of asthmatic mice. STIM1 is required for metabolic and transcriptional reprogramming that supports airway remodeling, including ASM proliferation, migration, secretion of cytokines and extracellular matrix, enhanced mitochondrial mass, and increased oxidative phosphorylation and glycolytic flux. Mechanistically, STIM1-mediated Ca2+ influx is critical for the activation of nuclear factor of activated T cells 4 and subsequent interleukin-6 secretion and transcription of pro-remodeling transcription factors, growth factors, surface receptors, and asthma-associated proteins. STIM1 drives airway hyperresponsiveness in asthmatic mice through enhanced frequency and amplitude of ASM cytosolic Ca2+ oscillations. Our data advocates for ASM STIM1 as a target for asthma therapy.

Lipoxin A4 inhibits ovalbumin-induced airway inflammation and airway remodeling in a mouse model of asthma

Asthma is a chronic respiratory disease, which is characterized by airway inflammation, remodeling and airway hyperresponsiveness. Airway remodeling is caused by long-term inflammation of the airways. Lipoxin A4 (LXA4) is a natural eicosanoid with powerful anti-inflammatory properties, and has been shown to serve a critical role in orchestrating pulmonary inflammation and airway hyper-responsiveness in asthmatic mice. However, its effect on airway remodeling is unknown. Female BALB/c mice were used to establish a mouse model of asthma which were sensitized and challenged by ovalbumin (OVA). LXA4 was intranasally administrated prior to the challenge. The results of our study indicated that LXA4 suppressed the OVA-induced inflammatory cell infiltration and T helper type 2 (Th2) cytokines secretion in the mouse model of asthma. Characteristics of airway remodeling, such as thickening of the bronchial wall and smooth muscle, overdeposition of collagen, and overexpression of α-smooth muscle actin (α-SMA) and collagen-I were reversed by LXA4. Furthermore, LXA4 suppressed the aberrant activation of the signal transducer and activator of transcription 3 (STAT3) pathway in the lung tissues of asthmatic mice. In conclusion, these findings demonstrated that LXA4 alleviated allergic airway inflammation and remodeling in asthmatic mice, which may be related to the inhibition of STAT3 pathway.

Enhanced airway hyperresponsiveness in asthmatic children and mice with A(H1N1)pdm09 infection.

BackgroundSevere asthma exacerbation is an important comorbidity of the 2009 HIN1 pandemic (A(H1N1)pdm09) in asthmatic patients. However, the mechanisms underlying severe asthma exacerbation remain unknown. In this study, airway hyperresponsiveness (AHR) was measured in pediatric asthma patients infected with A(H1N1)pdm09. We also evaluated AHR in asthmatic mice with A(H1N1)pdm09 infection and those with seasonal influenza for comparison.MethodsAHRs in asthmatic children were defined as the provocative acetylcholine concentration causing a 20% reduction in forced expiratory volume in 1 s (PC20). To investigate the pathophysiology using animal models, BALB/c mice aged 6‐8 weeks were sensitized and challenged with ovalbumin. Either mouse‐adapted A(H1N1)pdm09, seasonal H1N1 virus (1 × 105 pfu/20 μl), or mock treatment as a control was administered intranasally. At 3, 7, and 10 days after infection, each group of mice was evaluated for AHR by methacholine challenge using an animal ventilator, flexiVent. Lung samples were resected and observed using light microscopy to assess the degree of airway inflammation.ResultsAHRs in the children with bronchial asthma were temporarily increased, and alleviated by 3 months after discharge. AHR was significantly enhanced in A(H1N1)pdm09‐infected asthmatic mice compared to that in seasonal H1N1‐infected mice (p < .001), peaking at 7 days postinfection and then becoming similar to control levels by 10 days postinfection. Histopathological examination of lung tissues showed more intense infiltration of inflammatory cells and severe tissue destruction in A(H1N1)pdm09‐infected mice at 7 days postinfection than at 10 days postinfection.ConclusionOur results suggest that enhanced AHR could contribute to severe exacerbation in human asthmatic patients with A(H1N1)pdm09 infection.

Glutathione ethyl ester supplementation prevents airway hyper-responsiveness in mice.

BackgroundOxidative stress plays an important role in the pathogenesis of asthma. Glutathione (GSH) is considered to be one of the most important antioxidants. Our study systematically investigated the effect of the GSH alternative, glutathione ethyl ester (GSH-EE), on airway hyper-responsiveness (AHR) in mice.MethodsSixty-three male specific pathogen-free mice were used. Asthma was induced using a single dose of ovalbumin (OVA). The normal group (n=15) received vehicle only [Al(OH)3 in saline]. Then, 48 mice were divided into two groups, including a control group who received sodium phosphate buffer (pH =7.4), and the GSH-EE group who received 0.1% GSH-EE. AHR was measured 2, 6, and 12 hours after exposure to nebulized OVA (0.01%). The animals were then sacrificed, and lung tissue and the bronchi-alveolar lavage fluid (BALF) were harvested. Factors involved in the antioxidant response to asthma were then measured in these tissues, including thiol content (from GSH and protein), γ-glutamylcysteine synthetase (γ-GCS) activity and expression, and nuclear factor-erythroid-2-related factor (Nrf2) expression.ResultsThe GSH-EE group showed a significant attenuation of AHR (P<0.01) 2 hours after OVA challenge, and significantly enhanced thiol contents by approximately 45% (P<0.05) at 2 and 6 hours after the last OVA challenge, compared to the control group. γ-GCS activity was also higher in the GSH-EE group compared to the control group at different time points (P<0.01). γ-GCSh and Nrf2 protein expression increased in the GSH-EE group and the control group compared with the normal group, but there was no statistically significant difference (P>0.05) between the GSH-EE group and the control group.ConclusionsGSH-EE supplementation can prevent AHR in asthmatic mice during the early stages. It may function by serving as a precursor for GSH biosynthesis and by protecting sulfhydryl groups from oxidation.

Effect of neurokinin 1 receptor antagonist on airway inflammation and hyperresponsiveness in asthmatic mice

Objective To investigate the effects of neurokinin-1 receptor antagonist WIN 62, 577 on airway inflammation and airway hyperresponsiveness in asthmatic mice. Methods Thirty-two BALB/c mice(Specific-pathogen-free grade) were randomly divided into 4 groups: control group, asthmatic group, WIN 62, 577 intervention group and dexamethasone group.The asthmatic group, the WIN 62, 577 intervention group, and the dexamethasone group were given intraperitoneal injection of 0.2 ml of OVA sensitization solution at 0 d, 7 d, and 14 d, respectively.Then the asthmatic group, WIN 62, 577 group and dexamethasone group were given OVA challenge solution(4% OVA solution) by inhalation once a day for 30 min from 21 d to 28 d for 7 consecutive days.The WIN 62, 577 intervention group was given WIN 62, 577 300 μg intraperitoneal injection 1 h before each challenge; the dexamethasone group was given intraperitoneal injection of dexamethasone 2 mg/kg 1 h before each challenge.The airway responsiveness of each group of mice was detected by non-invasive pulmonary function test.The bronchoalveolar lavage fluid(BALF) was obtained for inflammatory count.The HE staining of lung tissue was used to observe airway inflammation in mice. Results Compared with the asthmatic group, the mice in the WIN 62, 577 intervention group showed less restlessness, standing upright, crouching back, scratching the ears and scratching the cheeks, shortness of breath and cyanosis of the lips.After inhaling different concentrations of acetylcholine, the Penh value of mice in the WIN 62, 577 intervention group and the dexamethasone group was significantly lower than that in the asthmatic group(P<0.05). Compared with the asthmatic group, the number of WBC and EOS in BALF decreased significantly in the WIN 62, 577 intervention group and the dexamethasone group(P<0.01). HE staining showed that the inflammatory changes in the lung tissue of mice in the WIN 62, 577 intervention group were significantly reduced, the bronchial epithelium did not fall off significantly, the mucosal edema was not obvious, the smooth muscle proliferation was reduced, and the inflammatory cell infiltration was reduced, similar to the airway changes in the dexamethasone group. Conclusion Neurokinin-1 receptor antagonist WIN 62, 577 can reduce airway inflammation and airway hyperresponsiveness in asthmatic mice. Key words: Asthma; Inflammation; Hyperresponsiveness; Substance P; Neurokinin-1 receptor

Cryptotanshinone attenuates allergic airway inflammation through negative regulation of NF-κB and p38 MAPK

This study is to determine the role and mechanism of cryptotanshinone (CTS) in allergic airway inflammation. Asthma induced by OVA was established in BALB/c mice. We found increased airway hyperresponsiveness (AHR), increased inflammatory cell infiltration, elevated levels of TNF-α, interleukin-1β (IL-1β), IL-4, IL-5, IL-6 and IL-13, decreased interferon gamma (IFN-γ) in lung tissue, increased content of total immunoglobulin E (IgE), OVA specific IgE, Eotaxin, ICAM-1, VCAM-1, nuclear factor-kappaB (NF-κB) and phosphorylation of p38 MAPK in lung tissue. However, the administration of CTS significantly decreased AHR in asthmatic mice, reduced inflammation around the bronchioles and inflammatory cells around airway, regulated cytokine production, reduced the total IgE and OVA-specific IgE levels, and inhibited NF-κB activation and p38 MAPK phosphorylation. In vitro experiments in 16 HBE cells revealed that CTS attenuated CAM-1 and IL-6 expression. These results indicate that CTS alleviates allergic airway inflammation by modulating p38 MAPK phosphorylation and NF-κB activation.

Enhanced pause correlates with airway neutrophils and airway-epithelial injury in asthmatic mice treated with dexamethasone

Objective: To investigate the correlations among airway inflammation, airway epithelial injury and airway hyperresponsiveness (AHR) in asthmatic mice treated with dexamethasone. Methods: Female BALB/c mice were sensitized with intraperitoneal and hypodermic injections of ovalbumin (OVA) and aluminum on days 0, 7 and 14, challenged with OVA starting on day 21 for 10 days, and treated with dexamethasone via intraperitoneal injection starting on day 28 for 3 days. Female C57BL/6 mice were treated intranasally with house dust mite (HDM) on days 1 and 14, challenged intranasally with HDM on days 21, 23, 25, 27 and 29, and treated with sivelestat (a selective neutrophil elastase inhibitor) via intraperitoneal injection after each challenge. Following the final challenge, enhanced pause (Penh) and differential cell counts in the broncho-alveolar lavage fluid were measured and the correlations were analyzed. Results: Compared with OVA-challenged BALB/c mice, the counterpart mice treated with dexamethasone showed reduced Penh and shedding of airway epithelial cells. In addition, we found that Penh 50 (an indicator of AHR) had positive correlations with airway neutrophils and shedding of airway epithelial cells, but no correlation with eosinophils, lymphocytes or macrophages. Moreover, shedding of airway epithelial cells had positive correlations with airway neutrophils, but no correlation with eosinophils, lymphocytes or macrophages. Further, sivelestat decreased Penh 50 and shed airway-epithelial cells in HDM-challenged C57BL/6 mice. Conclusions: Collectively, our findings suggest that airway neutrophils and excessive shedding of airway epithelial cells, but not eosinophils, lymphocytes or macrophages, may be involved in AHR in asthmatic mice treated with dexamethasone.

Fisetin inhibits the generation of inflammatory mediators in interleukin-1β–induced human lung epithelial cells by suppressing the NF-κB and ERK1/2 pathways

Fisetin, a flavone that can be isolated from fruits and vegetables, has anti-tumor and anti-oxidative properties and ameliorates airway hyperresponsiveness in asthmatic mice. This study investigated whether fisetin can suppress the expression of inflammatory mediators and intercellular adhesion molecule 1 (ICAM-1) in A549 human lung epithelial cells that were stimulated with interleukin-1β (IL-1β) to induce inflammatory responses. A549 cells were treated with fisetin (3–30 μM) and then with IL-1β. Fisetin significantly inhibited COX-2 expression and reduced prostaglandin E2 production, and it suppressed the levels of IL-8, CCL5, monocyte chemotactic protein 1, tumor necrosis factor α, and IL-6. Fisetin also significantly attenuated the expression of chemokine and inflammatory cytokine genes and decreased the expression of ICAM-1, which mediates THP-1 monocyte adhesion to inflammatory A549 cells. Fisetin decreased the translocation of nuclear transcription factor kappa-B (NF-κB) subunit p65 into the nucleus and inhibited the phosphorylation of proteins in the ERK1/2 pathway. Co-treatment of IL-1β–stimulated A549 cells with ERK1/2 inhibitors plus fisetin reduced ICAM-1 expression. Furthermore, fisetin significantly increased the effects of the protective antioxidant pathway by promoting the expression of nuclear factor erythroid-2-related factor-2 and heme oxygenase 1. Taken together, these data suggest that fisetin has anti-inflammatory effects and that it suppresses the expression of chemokines, inflammatory cytokines, and ICAM-1 by suppressing the NF-κB and ERK1/2 signaling pathways in IL-1β–stimulated human lung epithelial A549 cells.

Acacetin from Traditionally Used Saussurea involucrata Kar. et Kir. Suppressed Adipogenesis in 3T3-L1 Adipocytes and Attenuated Lipid Accumulation in Obese Mice.

Acacetin, a flavone that can be isolated from the Saussurea involucrata plant, has anti-tumor and anti-inflammatory properties that ameliorate airway hyperresponsiveness in asthmatic mice. This study investigated whether acacetin has anti-adipogenic effects in 3T3-L1 adipocytes and whether it regulates the inflammatory response in adipocytes and macrophages. It also investigated whether acacetin ameliorates lipid accumulation in high-fat diet- (HFD) induced obese mice. Differentiated 3T3-L1 cells were treated with acacetin. The glycerol levels in the culture medium were measured, and the expression of proteins and genes involved in adipogenesis and lipolysis were assayed by Western blot and real-time PCR, respectively. Inflammatory cytokine signaling pathway activity was assessed in macrophages that were treated with acacetin and cultured with differentiated medium from 3T3-L1 cells. Intraperitoneal injections of acacetin were administered to HFD-induced obese mice twice a week for 10 weeks. Acacetin significantly increased the levels of glycerol in the culture medium and significantly inhibited lipid accumulation in adipocytes. Acacetin reduced the expression of adipogenesis-related transcription factors, including the expression of the CCAAT/enhancer-binding protein; it also increased sirtuin 1 expression and AMPK phosphorylation in adipocytes. In macrophages cultured with differentiated media from 3T3-L1 adipocytes, acacetin reduced the levels of inflammatory mediators and the activity of the mitogen-activated protein kinase and NF-κB pathways. In obese mice, acacetin reduced both body weight and visceral adipose tissue weight. These results demonstrate that acacetin inhibited adipogenesis in adipocytes and in obese mice. Acacetin also reduced the inflammatory response of macrophages that were stimulated with differentiated media from 3T3-L1 cells.

Consequences of acute ozone exposure imposed on the culminated allergic pulmonary inflammation in an established murine model of asthma

Asthma exacerbations are often triggered by air pollution, including O3, whereas how patients with asthma exacerbations react to high levels of ambient ozone remain unknown. Here, we investigated the manner in which acute ozone exposure affects the pathophysiological characteristics of an asthma model on the premise of culminated allergic airway inflammation. The asthma model was constructed in mice, and enhanced pause (Penh), total and differential cell number, soluble mediator concentration, histopathology, and Muc5ac mRNA expression in the mice were observed. The results showed that ozone could induce airway hyperresponsiveness (AHR) in controls and an additional enhancement of preexisting AHR in asthmatic mice. When exposed to ozone, the asthmatic mice expressed more neutrophils, TNF-α, IL-13, and hyaluronan in bronchoalveolar lavage than controls. The mice with asthma and the controls both showed decreased epithelial cell density in the proximal and distal airways. Ozone aggravated the increased mucus production and mucin gene expression in mice with asthma. These results show that subjects with asthma may react differently to the same high level of ambient ozone, especially for those with asthma exacerbations.

Danggui Buxue Tang attenuates eosinophil infiltration and airway hyperresponsiveness in asthmatic mice

Danggui Buxue Tang (DBT), an herbal formula containing Angelica sinensis (AS) and Astragalus membranaceus (AM) (AS:AM = 1:5, designated as DBT1 here), has been used in Chinese medicine to enhance qi and blood circulation. In addition, DBT has served as a treatment for atopic dermatitis in dogs in Taiwan. It also may improve fibrosis in a rat model of pulmonary fibrosis. In this study, we evaluated the effect of oral administration of DBT1 in asthma in ovalbumin (OVA)-sensitized mice. Female BALB/c mice were sensitized and challenged with OVA and fed with DBT1 or modified formulas of DBT1, designated as DBT2 (AS:AM = 1:1) and DBT3 (AS:AM = 5:1), from days 21 to 27. DBT1 suppressed airway hyperresponsiveness and eosinophil infiltration in bronchoalveolar lavage fluid (BALF) and lung, and Th2-associated cytokines and chemokines were inhibited in BALF. In addition, levels of OVA-immunoglobulin E (IgE) also were suppressed in serum. However, treatment with DBT2 or DBT3 showed no improved effects relative to DBT1 in treating asthmatic symptoms. These results suggest that orally administered DBT (DBT1) can reduce allergic reactions in OVA-sensitized mice.

Flt-3 Ligand (FL) Treatment Upregulates PDL2 and Downregulates CCR7 in Distinct Myeloid Dendritic Cell (DC) Populations in the Lungs of Asthmatic Mice

RationaleWe observed that Flt-3 ligand reversed airway hyperresponsiveness (AHR) in a mouse model of asthma. FL preferentially affects the development and differentiation of myeloid DCs. In this study, we examined the phenotype of lung myeloid dendritic cells and their responses to ovalbumin (OVA) sensitization and FL treatment.MethodsA mouse model of asthma was established by administration of OVA and confirmed by AHR to methacholine. Sensitized and challenged mice were given either recombinant human FL or PBS. Non-sensitized mice received PBS as controls. CD11c+ lung DCs sorted by MACS were further labeled with CD11c, CD11b, CD8, PDL1, PDL2, and CCR7 antibodies conjugated with fluorochrome. FACS was used to identify phenotypic myeloid DC populations. The expression levels of cell surface markers were analyzed using flow cytometry.ResultsThree distinct lung myeloid DC populations, CD11c+CD11blow, CD11chiCD11bint, and CD11c+CD11bhi were identified. CD11chiCD11bint cells accounted for the majority of the lung myeloid DCs in non-sensitized condition. OVA sensitization significantly increased the proportion of CD11c+CD11bhi cells and decreased CD11chiCD11bint cells but FL treatment reversed the trend. CD11chiCD11bint cells had a higher expression of CD8, PDL1, and PDL2 as compared to CD11c+CD11bhi cells. CCR7 expression was higher in CD11c+CD11bhi cells. PDL2 was upregulated after sensitization and was further unregulated after FL treatment in CD11chiCD11bint cell population. CCR7 was upregulated after sensitization and downregulated after FL treatment in CD11c+CD11bhi cells.ConclusionsCD11chiCD11bint and CD11chiCD11bint DCs may be responsible for immune tolerance and immune response, respectively. FL reverses AHR in asthmatic mice possibly through upregulating PDL2 and downregulating CCR7 on DCs. RationaleWe observed that Flt-3 ligand reversed airway hyperresponsiveness (AHR) in a mouse model of asthma. FL preferentially affects the development and differentiation of myeloid DCs. In this study, we examined the phenotype of lung myeloid dendritic cells and their responses to ovalbumin (OVA) sensitization and FL treatment. We observed that Flt-3 ligand reversed airway hyperresponsiveness (AHR) in a mouse model of asthma. FL preferentially affects the development and differentiation of myeloid DCs. In this study, we examined the phenotype of lung myeloid dendritic cells and their responses to ovalbumin (OVA) sensitization and FL treatment. MethodsA mouse model of asthma was established by administration of OVA and confirmed by AHR to methacholine. Sensitized and challenged mice were given either recombinant human FL or PBS. Non-sensitized mice received PBS as controls. CD11c+ lung DCs sorted by MACS were further labeled with CD11c, CD11b, CD8, PDL1, PDL2, and CCR7 antibodies conjugated with fluorochrome. FACS was used to identify phenotypic myeloid DC populations. The expression levels of cell surface markers were analyzed using flow cytometry. A mouse model of asthma was established by administration of OVA and confirmed by AHR to methacholine. Sensitized and challenged mice were given either recombinant human FL or PBS. Non-sensitized mice received PBS as controls. CD11c+ lung DCs sorted by MACS were further labeled with CD11c, CD11b, CD8, PDL1, PDL2, and CCR7 antibodies conjugated with fluorochrome. FACS was used to identify phenotypic myeloid DC populations. The expression levels of cell surface markers were analyzed using flow cytometry. ResultsThree distinct lung myeloid DC populations, CD11c+CD11blow, CD11chiCD11bint, and CD11c+CD11bhi were identified. CD11chiCD11bint cells accounted for the majority of the lung myeloid DCs in non-sensitized condition. OVA sensitization significantly increased the proportion of CD11c+CD11bhi cells and decreased CD11chiCD11bint cells but FL treatment reversed the trend. CD11chiCD11bint cells had a higher expression of CD8, PDL1, and PDL2 as compared to CD11c+CD11bhi cells. CCR7 expression was higher in CD11c+CD11bhi cells. PDL2 was upregulated after sensitization and was further unregulated after FL treatment in CD11chiCD11bint cell population. CCR7 was upregulated after sensitization and downregulated after FL treatment in CD11c+CD11bhi cells. Three distinct lung myeloid DC populations, CD11c+CD11blow, CD11chiCD11bint, and CD11c+CD11bhi were identified. CD11chiCD11bint cells accounted for the majority of the lung myeloid DCs in non-sensitized condition. OVA sensitization significantly increased the proportion of CD11c+CD11bhi cells and decreased CD11chiCD11bint cells but FL treatment reversed the trend. CD11chiCD11bint cells had a higher expression of CD8, PDL1, and PDL2 as compared to CD11c+CD11bhi cells. CCR7 expression was higher in CD11c+CD11bhi cells. PDL2 was upregulated after sensitization and was further unregulated after FL treatment in CD11chiCD11bint cell population. CCR7 was upregulated after sensitization and downregulated after FL treatment in CD11c+CD11bhi cells. ConclusionsCD11chiCD11bint and CD11chiCD11bint DCs may be responsible for immune tolerance and immune response, respectively. FL reverses AHR in asthmatic mice possibly through upregulating PDL2 and downregulating CCR7 on DCs. CD11chiCD11bint and CD11chiCD11bint DCs may be responsible for immune tolerance and immune response, respectively. FL reverses AHR in asthmatic mice possibly through upregulating PDL2 and downregulating CCR7 on DCs.