Effects of NZ-107 on Airway Inflammation and Cell Activation in Guinea-pigs

Abstract— The effects of NZ-107 on some airway inflammation models and the generation of superoxide anion (O₂^?) were studied in guinea-pigs. Airway inflammation was caused by intra-tracheal injection of murine recombinant interleukin-5 (mrIL-5, 15 μg/animal), inhalation of platelet-activating factor (PAF, 0·003%) and intra-tracheal injection of leukotriene B₄ (LTB₄, 10 μg/animal). NZ-107 (4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone) at a dose of 50 mg kg^?1, intraperitoneally reduced mrIL-5- and PAF-induced eosinophilia. This compound at a dose of 25 and 50 mg kg^?1 also suppressed LTB₄-induced eosinophilia and neutrophilia in bronchoalveolar lavage fluid (BALF). On the other hand, prednisolone at a dose of 20 mg kg^?1, i.p., prevented the increased number of macrophages, eosinophils and neutrophils induced by mrIL-5, the increased number of eosinophils induced by PAF and the increased number of eosinophils and neutrophils induced by LTB₄ in BALF. Furthermore, both drugs reduced mrIL-5- or PAF-induced increase in the number of airway epithelial cells in BALF. The generation of O₂^? was measured by the method of cytochrome C reduction. NZ-107 (10–100 μg mL^?1) attenuated PAF- and FMLP-induced O₂^? production from macrophages and reduced PAF-induced O₂^? generation by eosinophils but had no effect on that from neutrophils. These results indicate that NZ-107 prevents the increased number of pulmonary eosinophils and airway epithelial cells and the activation of macrophages and eosinophils, suggesting that NZ-107 may be useful as a remedy for airway inflammatory diseases such as bronchial asthma.     

Involvement of PM2.5-bound protein and metals in PM2.5-induced allergic airway inflammation in mice

Abstract

Background: The aim of this study was to investigate the protein and trace element components of PM2.5 and their contribution to the allergic airway inflammation in BALB/c mice.

Methods: PM2.5, treated at high temperature and with a strong acid to hydrolyze any protein content and remove trace elements, was administered to BALB/c mice. Allergic airway inflammation was compared between the three groups (saline, pure PM2.5 and treated PM2.5) by evaluating airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cells, serum IgE, the mRNA of various cytokine (IL-4, IL-5, IL-13, eotaxin-1 and CXCL3), mucus protein mRNA (MUC5ac and MUC5b) and the filtration of inflammatory cells in the lung.

Results: The treatment of PM2.5 with a strong acid at a high temperature attenuated AHR, eosinophil percentage in BALF, mRNA levels of IL-13 and CXCL3 and peribronchial inflammation. On the contrary, the percentage of neutrophils in BALF, mRNA expression of MIP2α, EGFR, Nrf2, and TLR4 and 4-OH-2-nonenal levels in the lung was increased. Moreover, the treatment of the PM2.5 reduced PM2.5-bound proteins as well as the percentages of the trace elements in PM2.5 in the order Zn?>?Cu?> Pb?>?P?>?S?>?Mn?>?Fe?>?Ca?>?Ni, whereas the percentage of C, Si and Cl increased.

Conclusions: PM2.5 collected by of the cyclone system induced allergic airway inflammation in mice. PM2.5-bound proteins and acid-soluble metals may be involved in the pathogenesis of PM2.5-induced allergic airway inflammation.     

阿奇霉素对哮喘致敏大鼠气道炎症及Th1/Th2失衡的调节作用

目的:探讨阿奇霉素对哮喘(OVA)致敏大鼠气道炎症及Th1/Th2失衡的调节作用。方法:SD大鼠40只,随机分为生理盐水组、哮喘模型组、地塞米松组以及阿奇霉素组,每组10只。利用卵白蛋白(Ovalbumin,OVA)/Al(OH)3致敏与OVA雾化吸入激发建立大鼠过敏性气道炎症模型,收集肺泡灌洗液(BALF)进行白细胞分类计数。采用ELISA法测定肺泡灌洗液中IL-2、IL-4、TNF-α与ET-1的表达情况。光镜观察肺组织病理结构变化。结果:OVA模型大鼠肺泡灌洗液中的中性粒细胞、淋巴细胞以及嗜酸性粒细胞含量明显增加;HE染色观察肺组织病理结构出现明显的支气管上皮脱落、杯状细胞增生,支气管周围嗜酸性粒细胞明显浸润现象;BALF中IL-2、IL-4、TNF-α与ET-1的表达均明显高于生理盐水对照组(P<0.05)。阿奇霉素则显著降低肺泡灌洗液中中性粒细胞、淋巴细胞以及嗜酸性粒细胞含量;明显改善支气管上皮脱落、杯状细胞增生,支气管周围嗜酸性粒细胞浸润现象;BALF中IL-2、IL-4、TNF-α与ET-1的表达也明显低于OVA模型大鼠(P<0.05)。结论:阿奇霉素通过调节Th1/Th2失衡对过敏性哮喘的气道炎症具有明显的治疗作用。     

Modification of eosinophil function by suplatast tosilate (IPD), a novel anti-allergic drug

Suplatast tosilate (IPD), a new dimethylsulfonium agent, is used therapeutically in allergic diseases. Suplatast has been reported to attenuate airway hyperresponsiveness in guinea pigs, human IgE synthesis, and murine peritoneal eosinophilia. However, the effect of suplatast on human eosinophils is not known. In this study, we examined the effects of suplatast in human eosinophils on platelet activating factor (PAF, 1 microM)-induced chemotaxis by the blind well chamber technique, eosinophil adhesion to TNF-alpha (10 ng/ml) or IL-4 (10 ng/ml)-stimulated human umbilical vein endothelial cells (HUVECs), and expression of very late antigen-4 (VLA-4) on eosinophils and vascular cell adhesion molecule-1 (VCAM-1) on HUVECs by flow cytometry. Suplatast suppressed IL-4-induced eosinophil adhesion to HUVECs in a dose-dependent manner. Eosinophils from the normal subjects did not express VLA-4. However, there was a significant increase (P < 0.01) in the basal expression of VLA-4 in allergic patients. PAF or IL-4 did not enhance VLA-4 expression on eosinophils, and there was no significant effect of suplatast on VLA-4 expression in allergic patients. Suplatast did not affect TNF-alpha-induced VCAM-1 expression. Interestingly, suplatast significantly suppressed IL-4 induced VCAM-1 expression on HUVECs and PAF-induced eosinophil chemotaxis. These data suggest that suplatast may modify eosinophil participation in airway inflammation by attenuating inflammatory mediators-induced chemotaxis and adhesion to endothelial cells, and thus might be useful in the treatment of bronchial asthma.     

Effect of murine recombinant interleukin-5 on the cell population in guinea-pig airways.

1. An intratracheal injection of murine recombinant interleukin 5 (mrIL-5, 2-15 microgram/0.25 ml/animal) induced a dose-dependent increase in the number of macrophages, eosinophils, neutrophils and epithelial cells in the bronchoalveolar lavage fluid (BALF) of guinea-pigs 24 h after administration. Bovine serum albumin (15 micrograms/0.25 ml/animal), used as a reference material, did not cause any change of this type. 2. The intratracheal administration of mrIL-5 at a dose of 15 microgram showed a tendency to increase the number of these pulmonary inflammatory cells and epithelial cells in the BALF at 12 h with a significant increase observed at 24 h. 3. Prednisolone (20 mg kg-1, i.p.) inhibited the mrIL-5-induced increase in macrophages, eosinophils, neutrophils and epithelial cells. Ketotifen (2 mg kg-1, i.p.) reduced the mrIL-5-induced increase in the eosinophil, neutrophil and epithelial cell populations. The simultaneous injection of 2% disodium cromoglycate (DSCG) into the trachea prevented the mrIL-5-induced increase in the number of airway epithelial cells, without affecting changes in the other inflammatory leukocytes. 4. These results suggest that mrIL-5 is a potent inducer of lung inflammation, in terms of increased inflammatory leukocytes and epithelial cells in guinea-pig BALF. Prednisolone, DSCG and ketotifen are effective against mrIL-5-induced pulmonary inflammation, especially the desquamation of bronchial epithelial cells.     

Anti-asthmatic effect of schizandrin on OVA-induced airway inflammation in a murine asthma model

Asthma comprises a triad of reversible airway obstruction, bronchial smooth muscle cell hyperreactivity to bronchoconstrictors, and chronic bronchial inflammation. Clinical and experimental findings have established eosinophilia as a sign of allergic disorders. In the present investigation, we evaluated the anti-asthmatic effects of schizandrin and its underlying mechanisms in an in vivo murine asthmatic model. To accomplish this, female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and examined for the following typical asthmatic reactions: increased numbers of eosinophils and other inflammatory cells in bronchoalveolar lavage fluid (BALF); production of Th1 cytokines (such as tumor necrosis factor (TNF)-α in BALF); production of Th2 cytokines (such as interleukin IL-4 and IL-5) in BALF; presence of total and OVA-specific immunoglobulins (Ig)E in serum; presence of oxidative stress; hyperplasia of goblet cells in the lung; and marked influx of inflammatory cells into the lung. Our results collectively show that schizandrin exerts profound inhibitory effects on accumulation of eosinophils into the airways and reduces the levels of IL-4, IL-5, IFN-γ, and TNF-α in BALF. Additionally, schizandrin suppresses the production of reactive oxygen species (ROS) in a dose-dependent manner, and inhibits goblet cell hyperplasia and inflammatory cell infiltration in lung tissue. Thus, schizandrin has anti-asthmatic effects, which seem to be partially mediated by reduction of oxidative stress and airway inflammation, in a murine allergic asthma model. These results indicate that schizandrin may be an effective novel therapeutic agent for the treatment of allergic asthma.     

Motorcycle exhaust particles augment antigen-induced airway inflammation in BALB/c mice

Evidence indicates that environment pollutants from fossil fuel combustion compromise the immune system by enhancing allergic reactions and damaging the respiratory tract. This study was performed to investigate the effects of motorcycle exhaust particles (MEP), a major air pollutant especially in the urban areas of Taiwan, on allergen-induced airway inflammatory reactions in lab animals. BALB/c mice were intratracheally instilled with ovalbumin (OVA), MEP, or phosphate-buffered saline, 3 times every 2 wk. Airway hyperresponsiveness was measured in unrestrained mice by barometric plethsmography. Bronchoalveolar lavage fluid (BALF) and serum from treated animals were collected for cytokine and antibody determination by enzyme-linked immunosorbent assay (ELISA). Lung tissue stained with hematoxylin/eosin was examined. Data showed that MEP augmented OVA-induced airway inflammation; characterized by infiltration of eosinophils and neutrophils in BALF and lung tissue inflammation. The combination of OVA and MEP markedly increased interleukin-4 (IL-4), interleukin-5 (IL-5), and tumor necrosis factor-alpha (TNF-alpha) protein levels in BALF. In addition, MEP also augmented OVA-induced rise in OVA-specific immunoglobulin (Ig) G1 and IgE and airway hyperresponsiveness. Pretreated lavage cells with mitogen-activated protein kinase (MAPK) inhibitors showed that TNF-alpha release was significantly inhibited. This study found that MEP augmented antigen-induced allergic airway inflammation and airway hyperresponsiveness through a Th2-dominant pathway.     

The Effect of TYB-2285 on Dual Phase Bronchoconstriction and Airway Hypersensitivity in Guinea-pigs Actively Sensitized with Ovalbumin

Abstract— The effect of a new anti-asthmatic drug, TYB-2285 (3,5-bis(acetoxyacetylamino)-4-chloro-benzonitrile), was investigated in ovalbumin-sensitized guinea-pigs. When guinea-pigs were pretreated with TYB-2285 (300 mg kg^?l, p.o., single dose or consecutively for 7 days), the immediate asthmatic response was inhibited as demonstrated by diminished cyanosis, but not the bronchoconstriction. TYB-2285, given singly or consecutively, inhibited the appearance of late asthmatic response and the infiltration of inflammatory cells, such as eosinophils, into the airway. Additionally, airway hyper-responsiveness was also reversed by the single administration of TYB-2285. Luminol-dependent chemiluminescence of airway-infiltrated cells stimulated with A23187 was inhibited by TYB-2285 in a dose-dependent manner. The present study suggests that TYB-2285 inhibits late asthmatic response and airway hyper-responsiveness by inhibiting the accumulation of eosinophils and other inflammatory cells into the airway, and also by inhibiting the production of oxygen radicals from airway-infiltrated cells.     

Lysophosphatidic acid enhances in vivo infiltration and activation of guinea pig eosinophils and neutrophils via a Rho/Rho-associated protein kinase-mediated pathway

Lysophosphatidic acid (LPA) has been shown to be a chemoattractant in in vitro studies. The present study was carried out to determine whether LPA enhances infiltration of inflammatory cells in in vivo studies with guinea pigs. LPA (1 - 10 microg/ml), when by guinea pigs for 5 min, substantially increased the numbers of eosinophils and neutrophils in the bronchoalveolar lavege fluid (BALF), which was recovered at over 4 h after the inhalation of LPA. Infiltration in BALF was significantly inhibited by inhalation of Y-27632, an inhibitor of Rho-associated protein kinase (ROCK). LPA also increased superoxide production of eosinophils and neutrophils. In contrast, Y-27632 inhibited superoxide production. These findings suggest that LPA may contribute to infiltration and activation of inflammatory cells in bronchial asthma; furthermore, the Rho/ROCK-mediated pathway may be involved.     

Effect of waterpipe tobacco smoking on airway inflammation in murine model of asthma

Objective: There has been an increase in the popularity of waterpipe tobacco smoking (WTS) worldwide, especially in the younger population, including asthma patients. In this study, we investigated the effects of waterpipe smoking on airway inflammation, cytokine levels and oxidative stress markers in an antigen-driven murine model of asthma.

Materials and methods: Balb/c mice were divided into four groups; (1) control (received fresh air, ovalbumin sensitization and saline challenge), (2) WTS (received WTS, ovalbumin sensitization and saline challenge), (3) Ova S/C (received fresh air, ovalbumin sensitization and ovalbumin challenge) and (4) simultaneous WTS and Ova S/C (received WTS, ovalbumin sensitization and ovalbumin challenge). Airway inflammatory cells were evaluated in the broncho-alveolar lavage fluid. Cytokines [interleukin (IL)-13, 10 and 18] and oxidative stress markers [superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx)] were evaluated in the lung homogenates.

Results: Chronic exposure to WTS significantly increased the number of airway inflammatory cells in mice, specifically: eosinophils, neutrophils, macrophages and lymphocytes. The level of IL-13 in the lungs was increased and the level of IL-10 was reduced (p?Chronic WTS potentiated the increase in inflammatory cells induced by Ova S/C (p?p?Conclusions: Chronic WTS exposure induced airway inflammation in control mice and enhanced airway inflammation in murine model of asthma.     

Inhibitory effects of glucocorticoids on rat eosinophil superoxide generation and chemotaxis

Eosinophil infiltration into inflammatory tissues and the subsequent release of inflammatory mediators are the hallmarks of several inflammatory allergic diseases. Although there have been a considerable number of publications on anti-inflammatory effects of glucocorticoids, little is known about whether glucocorticoids affect the activation of eosinophils directly. We studied the effects of three glucocorticoids, mometasone furoate, dexamethasone and beclomethasone dipropionate, on superoxide generation and the chemotaxis of rat eosinophils. Highly purified rat eosinophils were treated for 6 h with mometasone furoate, dexamethasone or beclomethasone dipropionate. Eosinophils were stimulated with phorbol myristate acetate (PMA) for superoxide generation, while for induction of chemotaxis, platelet-activating factor (PAF) or leukotriene B(4) (LTB(4)) was used. None of the glucocorticoids used in the present study caused significant suppressive effects on superoxide generation induced by PMA. On the other hand, both PAF- and LTB(4)-induced migration of rat eosinophils were inhibited in a concentration-dependent manner by glucocorticoids. Mometasone furoate showed a significant effect at concentrations higher than 10(-11) M. Dexamethasone and beclomethasone dipropionate also caused a significant inhibition at concentrations higher than 10(-8) and 10(-7) M, respectively. These results indicated that the anti-inflammatory effects of glucocorticoids were mediated by direct inhibition of eosinophil migration. Furthermore, mometasone furoate was suggested to be more useful than the other drugs in the treatment of allergic diseases responsible for eosinophil chemotaxis.     

Zingiber officinale ameliorates allergic asthma via suppression of Th2-mediated immune response

Abstract

Context: Ginger has been used commonly in the traditional system of medicine for the treatment of respiratory disorders.

Objective: The present study investigates the immunosuppressive activity of ginger by using the mouse model of ovalbumin-induced allergic asthma.

Materials and methods: Treatment with ethanol extract (500?mg/kg) and aqueous extract (720?mg/kg) of rhizomes, and methylprednisolone (5?mg/kg) was initiated 1 week after second sensitization of mice with ovalbumin and continued for 7?d. RT-PCR followed by gel electrophoresis and ELISA were used for the evaluation of mRNA expression levels and protein levels of Th2 type markers, respectively. Lung tissue histopathology was conducted by using H&E and PAS staining.

Results: We observed significant reduction in goblet cell hyperplasia (0.83?±?0.17 and 1.0?±?0.26), infiltration of inflammatory cells in airways (0.67?±?0.33 and 1.0?±?0.37), and edema with vascular congestion (1.0?±?0.26 and 1.2?±?0.17) by both ethanol and aqueous extracts, respectively. A highly significant reduction of total and differential count of eosinophils and neutrophils in BALF, and eosinophil count in blood were also observed. Both extracts significantly inhibited Th2-mediated immune response, which is evident by a decrease in mRNA expression levels of IL-4 and IL-5. Protein levels of IL-4 and IL-5 in BALF, along with total serum IgE levels, were also significantly suppressed by both extracts.

Discussion and conclusion: Our study validated the traditional use of ginger in respiratory disorders and suggests that ginger reduces allergic airway inflammation, possibly by the suppression of Th2-mediated immune response.     

Motorcycle Exhaust Particles Induce Airway Inflammation and Airway Hyperresponsiveness in BALB/C Mice

A number of large studies have reported that environmental pollutantsfrom fossil fuel combustion can cause deleterious effects tothe immune system, resulting in an allergic reaction leadingto respiratory tract damage. In this study, we investigatedthe effect of motorcycle exhaust particles (MEP), a major pollutantin the Taiwan urban area, on airway inflammation and airwayhyperresponsiveness in laboratory animals. BALB/c mice wereinstilled intratracheally (i.t.) with 1.2 mg/kg and 12 mg/kgof MEP, which was collected from two-stroke motorcycle engines.The mice were exposed 3 times i.t. with MEP, and various parametersfor airway inflammation and hyperresponsiveness were sequentiallyanalyzed. We found that MEP would induce airway and pulmonaryinflammation characterized by infiltration of eosinophils, neutrophils,lymphocytes, and macrophages in bronchoalveolar lavage fluid(BALF) and inflammatory cell infiltration in lung. In addition,MEP treatment enhanced BALF interleukin-4 (IL-4), IL-5, andinterferon-gamma (IFN-) cytokine levels and serum IgE production.Bronchial response measured by unrestrained plethysmographywith methacholine challenge showed that MEP treatment inducedairway hyperresponsiveness (AHR) in BALB/c mice. The chemicalcomponents in MEP were further fractionated with organic solvents,and we found that the benzene-extracted fraction exerts a similarbiological effect as seen with MEP, including airway inflammation,increased BALF IL-4, serum IgE production, and induction ofAHR. In conclusion, we present evidence showing that the filter-trappedparticles emitted from the unleaded-gasoline-fueled two-strokemotorcycle engine may induce proinflammatory and proallergicresponse profiles in the absence of exposure to allergen.     

Effect of MX-68 on airway inflammation and hyperresponsiveness in mice and guinea-pigs

MX-68 is a newly synthesized antifolate, which is a derivative of methotrexate (MTX). In this paper, the effect of MX-68 on allergic airway responses in mice and guinea-pigs was studied. In the first experiment, antigen-induced airway inflammation and airway hyperresponsiveness (AHR) to acetylcholine in mice were examined and compared with the effects of classical antifolate methotrexate and prednisolone. Mice were sensitized with ovalbumin as an antigen and challenged with ovalbumin inhalation three times. After the last inhalation, AHR and airway inflammation were observed. An increase in Th2 cytokines (IL-4 and IL-5) and a decrease in a Th1 cytokine (IFN-gamma) in the bronchoalveolar lavage fluid (BALF), as well as an elevation of the immunoglobulin level in serum, were observed in sensitized mice. Oral administration of MX-68 had no effect on changes of body weight, but prednisolone reduced body weight during the experiment. The antigen-induced AHR and increases in the number of eosinophils and lymphocytes in BALF were significantly inhibited by MX-68. MX-68 interfered with the elevation of IL-4 and IL-5 levels in BALF, but had no effect on the decrease in IFN-gamma. Moreover, MX-68 significantly inhibited the elevation of serum IgE and IgG levels. In the guinea-pig model for bronchial asthma, biphasic increases in airway resistance (immediate asthmatic response, IAR, and late asthmatic response, LAR), as well as accumulated inflammatory cells in BALF, were observed after repeated antigen challenge. These asthmatic responses and inflammatory signs were significantly decreased by administration of MX-68. These results suggest that MX-68 obviously has an anti-inflammatory effect in an animal model of asthma and would be useful clinically for the treatment of bronchial asthma.     

Fine particulate matter (PM2.5) enhances allergic sensitization in BALB/c mice

Ambient particulate matter (PM), a component of air pollution, exacerbates airway inflammation and hyperreactivity in asthmatic patients. Studies showed that PM possesses adjuvant-like properties that enhance the allergic inflammatory response; however, the mechanism (or mechanisms) by which PM enhances the allergic response remains to be determined. The aim of this study was to assess how exposure to fine PM collected from Sacramento, CA, shapes the allergic airway immune response in BALB/c mice undergoing sensitization and challenge with ovalbumin (OVA). Eight-week-old BALB/c male mice were sensitized/challenged with phosphate-buffered saline (PBS/PBS; n = 6), PM/PBS (n = 6), OVA/OVA (n = 6), or OVA + PM/OVA (n = 6). Lung tissue, bronchoalveolar lavage fluid (BALF), and plasma were analyzed for cellular inflammation, cytokines, immunoglobulin E, and heme oxygenase-1 (HO-1) expression. Mice in the OVA + PM/OVA group displayed significantly increased airway inflammation compared to OVA/OVA animals. Total cells, macrophages, and eosinophils recovered in BALF were significantly elevated in the OVA + PM/OVA compared to OVA/OVA group. Histopathological grading indicated that OVA + PM/OVA treatment induced significant inflammation compared to OVA/OVA. Both immunoglobulin (Ig) E and tumor necrosis factor (TNF) α levels were significantly increased in OVA/OVA and OVA + PM /OVA groups compared to PBS/PBS control. The number of HO-1 positive alveolar macrophages was significantly elevated in lungs of mice treated with OVA + PM /OVA compared to OVA/OVA. Our findings suggest that fine PM enhances allergic inflammatory response in pulmonary tissue through mechanisms involving increased oxidative stress.     

Pharmacological profile of PKF242-484 and PKF241-466, novel dual inhibitors of TNF-alpha converting enzyme and matrix metalloproteinases, in models of airway inflammation

1. TNF-alpha converting enzyme (TACE) and matrix metalloproteinases (MMPs) are believed to play a role in various airway inflammatory disorders. Therefore we have tested the effect of two new inhibitors of TACE/MMPs (PKF242-484, PKF241-466) in models of airway inflammation. 2. PKF242-484 and PKF241-466 inhibited purified MMP-1, -2, -3, -9, -13 and rat collagenase at low nanomolar range. Both compounds inhibited the TNF-alpha release from activated human peripheral blood mononuclear cells with IC(50) values of 56+/-28 and 141+/-100 nM, respectively and had no significant effect on the activation of other human leukocytes, as neither neutrophils and eosinophils oxidative burst nor proliferation or cytokines production by T cells were inhibited in vitro. 3. PKF242-484 and PKF241-466 had beneficial effects in two different murine models of acute lung inflammation in vivo. The influx of neutrophils and lymphocytes into the airways was reduced 3 and 24 h after intranasal LPS challenge. This was accompanied by reduced levels of myeloperoxidase and elastase activities in the bronchoalveolar lavage. Furthermore, a complete inhibition of TNF-alpha release into the airways was observed. In addition, PKF242-484 effectively reduced the influx of neutrophils, eosinophils and lymphocytes in a model of acute allergic lung inflammation. 4. PKF242-484 and PKF241-466 are two novel and potent dual inhibitors of TACE and MMPs, which show activity in in vivo models of lung inflammation. Such compounds could have beneficial effects in airway inflammatory conditions such as asthma and chronic obstructive pulmonary disease.     

Eosinophil accumulation in pulmonary airways of guinea-pigs induced by exposure to an aerosol of platelet-activating factor: effect of anti-asthma drugs.

1. Exposure of guinea-pigs to aerosols of platelet activating factor (PAF) (0.01 to 100 micrograms ml-1) induced a dose-dependent increased incidence of eosinophils in bronchoalveolar lavage fluid (BAL) at 48 h. Total leucocyte numbers and the percentages of lymphocytes and neutrophils were unchanged in BAL fluid. 2. Increased numbers of eosinophils were detected in BAL 1 h after exposure to PAF but eosinophilia was not maximal until 48 h. One week after exposure to PAF, the percentage of eosinophils in BAL was within the normal range. 3. Depletion of circulating platelets or neutrophils by intravenous injection of specific antisera did not modify accumulation of eosinophils in the airway lumen following inhalation of PAF (10 micrograms ml-1). 4. PAF-induced pulmonary airway eosinophil accumulation was inhibited by treatment with SDZ 64-412, a selective PAF-antagonist, whether the compound was administered before, or 30 min after, inhalation of PAF. 5. Pulmonary airway eosinophil accumulation due to inhaled PAF (10 micrograms ml-1) was inhibited by prior treatment with aminophylline, cromoglycate, ketotifen, dexamethasone and AH 21-132. 6. Pulmonary airway eosinophil accumulation due to inhaled PAF (10 micrograms ml-1) was not inhibited by prior treatment with indomethacin, salbutamol or mepyramine.     

Apolipoprotein E negatively regulates murine allergic airway inflammation via suppressing the activation of NLRP3 inflammasome and oxidative stress

Apolipoprotein E (ApoE) has been reported as a steroid unresponsive gene and functions as a negative regulator of airway hyperreactivity (AHR) and goblet cell hyperplasia in house dust mite (HDM)-challenged mice. However, the role of ApoE in Ovalbumin (OVA)-induced allergic airway inflammation disease and the underlying mechanism are still unknown. In the present study, murine allergic airway inflammation was induced by inhaled OVA for consecutive 7 days in wild type (WT) and ApoE^−/− mice. In the OVA-induced model, the ApoE level in the bronchoalveolar lavage fluid (BALF) and lung tissues was significantly higher than that of control mice. And ApoE deficiency aggravated airway inflammation including leukocytes infiltration, goblet cell hyperplasia and IgE production as compared to those of WT mice after OVA- challenged, suggesting ApoE servers as an endogenous negative regulator of airway inflammation. Furthermore, OVA challenge elevated the activation of NLRP3 inflammasome with higher protein expression of NLRP3, caspase1 and IL-1β, enhanced oxidative stress with higher expression of 8-OHdG, nitrotyrosine and SOD2, increased the expression of mitochondrial fusion/fission markers including Optic Atrophy 1 (OPA1), Mitofusion 2 (Mfn2), dynamin-related protein 1 (DRP1) and Fission 1 (Fis1). However, these OVA-induced changes were augmented in ApoE^−/− mice. Collectively, our results demonstrated that the OVA-induced airway inflammation was aggravated in ApoE^−/− mice, and suggested that the underlying mechanism may be associated with the augmented activation of NLRP3 inflammasome and oxidative stress in ApoE^−/− mice, therefore targeting ApoE pathway might be a novel therapy approach for allergic airway diseases such as asthma.     

A Novel CC-Chemokine Receptor 3 Antagonist,Ki19003, Inhibits Airway Eosinophilia and Subepithelial/Peribronchial Fibrosis Induced by Repeated Antigen Challenge in Mice

CC-chemokine receptor 3 (CCR3) is a chemokine receptor for which major ligands, CC-chemokine ligand (CCL) 11, CCL24, and CCL26, are known to be involved in chemotaxis for eosinophils. In the present study, we evaluated the effect of a low molecular weight CCR3-receptor antagonist, Ki19003 (4-[[5-(2,4-dichlorobenzylureido)pentyl][1-(4-chlorophenyl)ethyl]amino]butanoic acid), on airway remodeling in a mouse model of allergic asthma. BALB/c mice were sensitized twice by intraperitoneal injection of ovalbumin (OA) and exposed daily to 1% OA for 3 weeks. Twenty-four hours after the final antigen challenge, bronchoalveolar lavage and histological examinations were carried out. Ki19003 clearly inhibited antigen-induced increase in the number of eosinophils in bronchoalveolar lavage fluid (BALF), but did not affect the number of other cell types examined in this study. Ki19003 also inhibited the increased production of transforming growth factor-β1 in BALF and the amount of hydroxyproline in the lungs in a dose-dependent manner. Furthermore, Ki19003 significantly attenuated allergen-induced subepithelial and peribronchial fibrosis. These findings indicate that CCR3 antagonism prevents not only the infiltration of eosinophils into the airways but also the development of allergen-induced subepithelial and peribronchial fibrosis. Therefore, a CCR3 antagonist may be useful in the treatment of airway remodeling, especially subepithelial and peribronchial fibrosis, in allergic asthma.     

Induced apoptosis of Th2 lymphocytes and inhibition of airway hyperresponsiveness and inflammation by combined lactic acid bacteria treatment

Several lactic acid bacteria (LAB) demonstrably regulate the immune system and inhibit allergic disease. This study examined whether oral feeding of either Lactobacillus paracasei (L. paracasei) BB5 and/or Lactobacillus rhamnosus (L. rhamnosus) BB1 suppresses ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and inflammation in a murine model. OVA-specific immune responses, cell profile of bronchoalveolar lavage fluid (BALF), and airway AHR were assessed following OVA and methacholine challenge. We investigated whether LAB can enhance CD4⁺FoxP3⁺ and CD8⁺FoxP3⁺ regulatory T (Treg) cells in splenic cells and apoptosis of CD4⁺IL-4⁺ T cells. Results found oral administration of combined LAB better than single L. paracasei or L. rhamnosus strain, improving Penh ratio after challenge with methacholine. High-dose combined LAB starkly decreased synthesis of OVA-specific IgE and IgG2a levels, as well as eosinophils infiltration in BALF. In addition, CD4⁺IL-4⁺ T cells decreased while CD4⁺FoxP3⁺ and CD8⁺FoxP3⁺ Treg cells increased significantly in splenic mononuclear cells of high-dose combined LAB group. Findings indicate allergen-induced AHR and airway allergic inflammation suppressed by enhances CD4⁺FoxP3⁺ and CD8⁺FoxP3⁺ Treg populations as well as Th1 cell response after treating with combined LAB. This study may provide a basis for developing a novel therapeutic or protective method for airway allergic disease.