Inhibitory Effects of Anti-Immunoglobulin E Antibodies on Airway Remodeling in A Murine Model of Chronic Asthma

Background: Airway remodeling is one of the cardinal features of asthma and is thought to play a pivotal role in refractory or persistent asthma. Immunoglobulin E (IgE) has a major effect on the pathogenesis of asthma. The aim of this study was to investigate the effects of anti-IgE antibody not only on airway inflammation and bronchial hyperresponsiveness, but also on airway remodeling in a murine model of chronic asthma. Methods: The authors developed a mouse model of chronic asthma in which ovalbumin (OVA)-sensitized female BALB/c-mice were exposed to intranasal OVA administration twice a week for 3 months. Anti-IgE antibodies were administered intravenously starting on the 38th day and once a month thereafter for 3 months during the intranasal OVA challenge. Results: Mice that were chronically exposed to OVA developed sustained eosinophilic airway inflammation and airway hyperresponsiveness (AHR) to methacholine and showed increased levels of collagen, hydroxyproline, and α-smooth muscle actin, as compared with control mice. Treatment with anti-IgE antibody inhibited the development of AHR, eosinophilic inflammation, and airway remodeling. Moreover, anti-IgE antibody treatment reduced the levels of interleukin (IL)-5 and IL-13 in the bronchoalveolar lavage fluids, although it did not affect the levels of IL-10, transforming growth factor-β, and activin A. Conclusion: These results suggest that anti-IgE antibody treatment modulates the airway inflammation and remodeling associated with chronic allergen challenge. The inhibition of inflammation may be related to the regulation of Th2 cytokines. However, the mechanisms underlying the blocking of airway remodeling by anti-IgE antibody remain to be elucidated.     

Serum B12 Tryptase Level as a Marker of Allergic Airway Inflammation in Asthma

Tryptase is a specific marker of mast-cell activation and plays a part in the pathophysiology of various allergic diseases including asthma, but little is known of the spillover of this enzyme into the systemic circulation. Therefore, we measured serum levels of mast-cell-derived tryptase in 21 patients with mild to moderate asthma and 20 healthy subjects, using a B12 monoclonal antibody-based immunofluoroassay that detects both monomers and tetramers of α- and β-tryptases. There was a good correlation between serum and sputum tryptase levels, and, compared with healthy subjects (1.68 ± 0.31 ng/ml), asthma patients had higher concentrations of serum tryptase (atopic asthma: 4.18 ± 0.95 ng/ml, p = 0.022; nonatopic asthma: 3.93 ± 0.82 ng/ml, p = 0.031). Although serum tryptase levels did not correlate with asthma symptom scores, peak expiratory flow, or forced expiratory volume in 1 s, they positively correlated with mast-cell and eosinophil counts (p = 0.041 and p = 0.025, respectively) and eosinophil cationic protein contents (p = 0.029) in induced sputum. These results suggest that serum tryptase detected with B12 antibody is a marker of allergic airway inflammation in asthma.     

雌激素替代治疗对绝经后妇女血管内皮舒张功能的影响

为了探讨雌激素抗动脉粥样硬化和降低冠心病发病危险的机制 ,采用无创性高分辨超声法观察雌激素替代治疗对绝经后妇女血管内皮依赖性舒张功能的影响 ,于治疗前后测量血清雌二醇、一氧化氮和血脂水平。结果发现 ,绝经后妇女较绝经前妇女血清雌二醇和一氧化氮下降 (P <0 .0 0 1) ,肱动脉血流介导的舒张反应较绝经前明显下降 (3.84 %± 2 .18%比 10 .0 5 %± 3.18% ,P <0 .0 0 1) ;短期雌激素替代治疗后雌二醇和一氧化氮水平较治疗前极显著升高 (P <0 .0 0 1) ,肱动脉血流介导的舒张反应也显著改善 (9.16 %± 3.0 2 % ,P <0 .0 0 1) ,而雌激素替代治疗并未使血脂发生明显改善 (P >0 .0 5 )。相关分析发现肱动脉血流介导的舒张反应与雌二醇和一氧化氮呈正相关(r值分别为 0 .5 6 4和 0 .72 9,P <0 .0 0 1) ,与总胆固醇呈负相关 (r为 - 0 .36 9,P <0 .0 5 )。结果提示短期雌激素替代治疗可明显改善绝经后妇女内皮依赖性舒血管功能障碍 ,且与血脂的改善无关 ,可能与雌激素的直接血管保护作用有关。     

Co-Administration of Vaccination with DNA Encoding T Cell Epitope on the Der p and BCG Inhibited Airway Remodeling in a Murine Model of Chronic Asthma

Therapeutic modalities of airway remodeling in asthma have proved to be unsuccessful regarding reversing the previously established chronic airway changes. Recently, the potential of plasmid DNA to inhibit the Th2 immune response has been demonstrated in animal models of asthma. Bacillus Calmette-Guerin (BCG) immunization also induced immunomodulation, which appeared to be reliant on the properties of the interferon-gamma that was produced. Mice were immunized with house dust mite extract (HDM). At the 3 week point, we injected BCG subcutaneously into mice on three successive weeks. One week after the BCG injection, we immunized mice with the DNA plasmid encoding for murine T-cell epitope on Dermatophagoide pteronyssinus 2 thrice weekly. At 9 weeks after immunization, we measured airway responsiveness. Twenty four hours later, we performed bronchoalveolar lavage and histological examinations. Co-administration of DNA vaccination and BCG resulted in a partial suppression of the overproduction of goblet cells and the thickness of the peribronchial smooth muscle in ongoing allergic responses. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was reduced, and regarding the change of cytokines, the concentration of IL-4 was also decreased, but interferon-gamma was increased in the co-administration group, opposed to the asthma group. These results suggest that co-administration of vaccination with the DNA encoding T-cell epitope and BCG are effective regarding ongoing allergic response and might constitute an ideal method for combating allergic disease in the future.     

Co-Administration of Vaccination with DNA Encoding T Cell Epitope on the Der p and BCG Inhibited Airway Remodeling in a Murine Model of Chronic Asthma

Therapeutic modalities of airway remodeling in asthma have proved to be unsuccessful regarding reversing the previously established chronic airway changes. Recently, the potential of plasmid DNA to inhibit the Th2 immune response has been demonstrated in animal models of asthma. Bacillus Calmette-Guerin (BCG) immunization also induced immunomodulation, which appeared to be reliant on the properties of the interferon-gamma that was produced. Mice were immunized with house dust mite extract (HDM). At the 3 week point, we injected BCG subcutaneously into mice on three successive weeks. One week after the BCG injection, we immunized mice with the DNA plasmid encoding for murine T-cell epitope on Dermatophagoide pteronyssinus 2 thrice weekly. At 9 weeks after immunization, we measured airway responsiveness. Twenty four hours later, we performed bronchoalveolar lavage and histological examinations. Co-administration of DNA vaccination and BCG resulted in a partial suppression of the overproduction of goblet cells and the thickness of the peribronchial smooth muscle in ongoing allergic responses. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was reduced, and regarding the change of cytokines, the concentration of IL-4 was also decreased, but interferon-gamma was increased in the co-administration group, opposed to the asthma group. These results suggest that co-administration of vaccination with the DNA encoding T-cell epitope and BCG are effective regarding ongoing allergic response and might constitute an ideal method for combating allergic disease in the future.     

Regulation of VEGF-A, VEGFR-I, thrombospondin-1, -2, and -3 expression in a human pituitary cell line (HP75) by TGFbeta1, bFGF, and EGF

Pituitary tumors are highly vascular neoplasms, which suggest an important role of angiogenesis in pituitary tumor growth. We used the human pituitary cell line (HP75) to examine the effects of the growth factors TGFβ1, bFGF, and EGF on cell growth, and on the regulation of the pro-angiogenic growth factor VEGF-A and the VEGFR-I and the anti-angiogenic molecules thrombospondin (TSP) TSP-1 and TSP-2 along with TSP-3. Real-time RT-PCR was used to measure mRNA levels, and Western blot was used to analyze TSP-1 and TSP-2 protein levels. TGFβ1 treatment (1×10⁻⁹ M) increased VEGF-A mRNA levels significantly (p<0.05) after 4 and 24 h of treatment. TGF β1 treatment decreased VEGF-R mRNA levels after 96 h of treatment (p<0.05). After 96 h of treatment, TSP-1 and TSP-2 mRNA levels were significantly increased (p<0.05) by TGFβ1 treatment, which also inhibited HP75 cell growth. Basic FGF also increased TSP-1 mRNA levels after 96 h of treatment, but did not regulate growth of the pituitary tumor cells. Basic FGF and EGF did not modulate changes in VEGF-A mRNA levels after 4 and 24 h of treatment, but EGF increased VEGF-A significantly (p<0.05) after 96 h of treatment. These results indicate that TGFβ1 treatment may regulate angiogenesis in pituitary cells by initially increasing levels of pro-angiogenic VEGF-A and then stimulating the anti-angiogenic molecules TSP-1 and TSP-2 levels.     

Airway Remodeling and Serum Total Immunoglobulin E (IgE) Levels in a Murine Model of Asthma

A murine model of allergen-induced airway inflammation, epithelial phenotypic changes, and total immunoglobulin E (IgE) levels is described. Mice were sensitized to ovalbumin without adjuvant and challenged by multiple intratracheal instillations of ovalbumin by a nonsurgical technique. After repeated challenges, the basement membrane of the airway epithelium showed fibrosis, inflammatory cell infiltration at peribronchial and perivascular sites, and goblet cell hyperplasia. In addition, total IgE levels were found to be increased significantly. Further studies which will evaluate the contribution of each feature of remodeled airway to the natural history of asthma are definitely needed.     

Airway Remodeling and Serum Total Immunoglobulin E (IgE) Levels in a Murine Model of Asthma

A murine model of allergen-induced airway inflammation, epithelial phenotypic changes, and total immunoglobulin E (IgE) levels is described. Mice were sensitized to ovalbumin without adjuvant and challenged by multiple intratracheal instillations of ovalbumin by a nonsurgical technique. After repeated challenges, the basement membrane of the airway epithelium showed fibrosis, inflammatory cell infiltration at peribronchial and perivascular sites, and goblet cell hyperplasia. In addition, total IgE levels were found to be increased significantly. Further studies which will evaluate the contribution of each feature of remodeled airway to the natural history of asthma are definitely needed.     

日本血吸虫不同阶段抗原免疫抑制过敏性哮喘小鼠气道炎症的实验观察

目的 观察日本血吸虫不同生活史阶段抗原对过敏性哮喘小鼠气道炎症的影响。方法 雌性BALB/c小鼠48只,随机均分8组,A组为健康对照组;B组为哮喘模型组,以鸡卵白蛋白（OVA）抗原腹腔注射致敏,OVA滴鼻诱发哮喘;C、D和E组小鼠分别用可溶性虫卵抗原（SEA）、可溶性成虫抗原（SWA）和童虫抗原（SSA）经腹部皮下免疫,共4次,每次间隔1周,末次免疫后1周再按B组方法诱发哮喘;F、G和H组分别用SEA、SWA和SSA免疫接种小鼠（免疫方法及剂量分别同C、D、E组）,末次免疫后1周用等量生理盐水代替OVA处理小鼠,不诱发哮喘。诱发哮喘后48 h剖杀各组小鼠,观察各组小鼠肺组织的病理变化和支气管肺泡灌洗液（BALF）中的相关细胞成分及细胞因子的变化。 结果 A组小鼠气道肺组织无明显炎症变化;B组小鼠气道肺组织可见明显的炎性细胞,尤其是嗜酸粒细胞的浸润;C、D和E组小鼠气道肺组织炎症明显轻于B组小鼠。B组小鼠BALF中白细胞总数［（98.4±16.1）×10⁴/ml］、嗜酸粒细胞百分数[（17.6±4.3）×10⁴/ml]和白细胞介素-5(IL-5)水平［（197.9±36.5）pg/ml］均明显高于A组［分别为（8.2±1.1）×10⁴/ml、（0.02±0.01）×10⁴/ml和（12.3±7.4）pg/ml］,而IL-10和γ干扰素(IFN-γ)水平明显低于A组。C、D和E组小鼠BALF中白细胞总数、嗜酸粒细胞百分数和IL-5水平均明显低于B组,而IL-10,IFN-γ水平则明显高于B组,差异有统计学意义（P<0.05）。 结论 日本血吸虫不同抗原免疫后能有效调节过敏性哮喘小鼠的细胞因子平衡,同时对哮喘小鼠嗜酸粒细胞在肺组织中的浸润及肺组织炎症都有一定的抑制作用。     

A bone-derived mixture of TGFβ-superfamily members forms a more mature vascular network than bFGF or TGF-β2 in vivo

Clinical trials of therapeutic angiogenesis for the treatment of cardiovascular ischemia have failed to meet the expectations with the use of single growth factors, namely VEGF and bFGF. We show here that a bovine bone-derived growth factor mixture (GFM) of TGFβs, BMPs, and no more than 0.1% aFGF can initiate a dose-dependent angiogenic response in subcutaneously implanted Growth Factor Reduced Matrigel plugs that includes abundant smooth muscle actin positive (SMA+) tubes and functional CD31+, red blood cell filled, capillaries. Tube forming activity of the single factors, recombinant bFGF and bone-derived TGF-β2, were comparable to GFM, but only the bone-derived factors were able to create a larger fraction of SMA+ tubes than Matrigel alone at an equal dose. Basic FGF formed a greater number of RBC-filled capillaries within the plugs than GFM or TGF-β2 at the highest doses, although GFM created RBC-filled capillaries that penetrated deeper into the plugs than bFGF. However, bFGF showed the greatest number of non-cell-lined, RBC-filled pools, suggestive of vessel rupture, and the largest number of plugs showing signs of fluid accumulation in the form of large, cell-lined clefts in the implants. TGF-β2 showed less RBC-filled pools, but a significant number of implants with signs of fluid accumulation. At high doses of GFM penetration by blood vessels and mesenchymal cells was obstructed by cartilage development within the plugs accompanied by a prominent band of SMA+ granulation tissue with abundant RBC-filled capillaries encapsulating the implants. Thus, GFM is also capable of dramatically remodeling the vascular system in the interstitial space surrounding the plug. These results show that GFM is capable of inducing the formation of a more mature vascular system than that formed by the single factors bFGF and TGFβ-2. Natural mixtures of TGFβs, BMPs, and FGFs may have superior clinical utility in therapeutic angiogenesis applications.     

Estrogen evokes a rapid effect on intracellular calcium in neurons characterized by calcium oscillations in the arcuate nucleus

Rapid estrogen effects became an interesting topic to explain estrogen effects not associated with the classical nuclear pathway. The rapid estrogen effect on intracellular calcium oscillations was characterized in neurons of the arcuate nucleus. Ratiometric calcium imaging (fura-2AM) was used to measure intracellular calcium in brain slices of female Swiss Webster mice (median of age 27 days p.n.). Calcium oscillations were dependent on intracellular calcium and also on calcium influx from the extracellular space. The perfusion of slices with calcium-free solution inhibited spontaneous calcium oscillations. The metabotropic glutamate receptor agonist t-ACPD (5 microM) and low concentrated ryanodine (100 nM) induced intracellular calcium release when slices were perfused with calcium-free solution. 17beta-estradiol (10 nM) also induced intracellular calcium release in calcium-free ACSF. This effect was inhibited by the preceding administration of thapsigargin (2 microM) indicating the association of the rapid estrogen effect with intracellular calcium stores. The administration of the non-selective phospholipase C-inhibitor ET-18 (30 microM), but not U73122 (10 microM), and the inhibition of protein kinase A by H-89 (0.25 microM) suppressed the rapid estrogen effect. Analyses indicated a qualitative, but not quantitatively significant effect of 17beta-estradiol on calcium oscillations.     

早期给予雌激素对去卵巢兔动脉斑块及血脂、单核细胞趋化蛋白1的影响

目的观察早期不同剂量雌激素替代治疗对高脂饮食诱导的去卵巢雌兔动脉粥样硬化及血脂、单核细胞趋化蛋白1的影响。方法健康雌性新西兰白兔28只，随机分为假手术组、去卵巢组、去卵巢＋小剂量雌激素替代治疗组（苯甲酸雌二醇200μg）和去卵巢＋大剂量雌激素替代治疗组（苯甲酸雌二醇1mg）。术后给予高脂饲料喂养，测定血清总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、雌二醇和单核细胞趋化蛋白1浓度，并分离主动脉标本行组织形态学观察。结果与假手术组比较，去卵巢组高脂喂食后血清总胆固醇、低密度脂蛋白胆固醇、单核细胞趋化蛋白1均明显升高，血清高密度脂蛋白胆固醇、雌二醇水平下降；而雌激素替代治疗组的上述指标与假手术组相似；与小剂量雌激素替代治疗组比较，大剂量雌激素替代治疗组12周后雌二醇水平较高、单核细胞趋化蛋白1水平较低。比较主动脉斑块面积，去卵巢组大于假手术组，而雌激素替代治疗两组明显小于去卵巢组和假手术组，但雌激素替代治疗两组之间差异无显著性。主动脉斑块面积与高脂喂养12周后血清低密度脂蛋白胆固醇、总胆固醇以及单核细胞趋化蛋白1水平呈明显正相关（r分别为0．765，0．803，0．829，P均〈0．01），与血清高密度脂蛋白胆固醇（r=-0．441，P〈0．05）、雌二醇水平呈负相关（r=-0．755，P〈0．01）。结论早期雌激素替代治疗可改善血脂代谢、降低单核细胞趋化蛋白1水平、减少主动脉斑块面积。雌激素的调脂、抗炎作用可能与其抗动脉粥样硬化作用有关。     

Modulation of VEGF/Flk-1 receptor expression in the rat pituitary GH3 cell line by growth factors

Both vascular endothelial growth factor (VEGF) and its receptor Flk-1 are expressed in normal pituitary cells and in the prolactin- and growth hormone-producing GH3 cell line of the rat, thus suggesting autocrine/paracrine function. Regulation of the Flk-1 receptor system in pituitary cells is poorly understood, but evidence suggests that up-regulated growth factors play a role in its expression and activation. To study the role of growth factors in this process, we examined changes in VEGF and Flk-1 expression in GH3 cells following varied exposure to βFGF, EGF, and TGFβ1. Immunofluorescence labelling and laser scanning cytometry were used to measure changes in VEGF and Flk-1 expression. Results showed that βFGF, EGF and TGFβ up-regulated the VEGF/FLK-1 receptor system. Distinct patterns of activation were detected. At 2 hours, EGF and TGFβ caused no significant changes in VEGF and Flk-1 expression; however, βFGF up-regulated VEGF expression in 99% of cells but only induced modest changes in Flk-1 overexpression. A similar percentage of cells overexpressed VEGF after 24-hour incubation with βFGF, but more prominent Flk-1 overexpression was detected. At 24 hours, EGF and TGFβ1 induced a significant increase in both VEGF and Flk-1 expression. In summary, our findings show that VEGF/Flk-1 expression in pituitary cells may be altered by different growth factors. This may affect angiogenesis and the progression of pituitary tumors.     

Modulation of Airway Responsiveness to Acetylcholine by Nitric Oxide in a Rabbit Model

Nitric oxide (NO) is an important mediator in the regulation of bronchial muscle tone and airway responsiveness. We investigated the influence of exogenous NO on airway responsiveness to acetylcholine aerosols (ACH) in normal and in hyperresponsive rabbits. White New Zealand rabbits were anesthetized, intubated, and breathed room air spontaneously. Responses of respiratory parameters in ACH challenge tests were measured. In group A the influence of NO on ACH infusion-induced airway constriction was measured. Airway responses to aerosols from 0.25 to 8.0% ACH solutions in saline were measured with 150 and 300 ppm NO inhalation (groups B and C) and compared with the same animals' responses without NO. Moreover, we examined the influence of NO synthase inhibition on airway responsiveness (group D) and the modulatory effect of NO in hyperresponsive animals (group E). 300 ppm NO inhalation significantly decreased the bronchoconstrictor response to intravenously administered ACH (group A). However, the baseline value of dynamic elastance (E_dyn) was only marginally lower under the influence of 300 ppm NO. During inhalation of 150 or 300 ppm NO, responses to nebulized 2.0% and less ACH solutions remained nearly unaltered. Responses to aerosols of 4.0 and 8.0% diminished significantly (groups B and C). Following 40 min of aerosolized N-nitro-l-arginine-methyl ester (l-NAME) solution (a NO synthase inhibitor, 1.2 mM) inhalation, the response of E_dyn to ACH increased significantly in group D. In group E, animals inhaled 500 mg/m³ ammonium persulfate (APS), an oxidant with various industrial applications, after the first ACH challenge test (0.2, 1.0, and 2.0% ACH). After 2 h of APS exposure, the ACH-induced broncho constriction was increased significantly in the challenge test. After another 2 h of APS inhalation, the airway responsiveness to ACH was tested under the influence of 300 ppm NO. NO significantly decreased the response to ACH to almost the same level as before APS exposure. The results indicate that responses to high ACH concentrations as well as an APS-induced increase in ACH responsiveness were effectively reduced by high concentrations of inhaled NO. Accepted for publication: 11 February 1997     

Deterioration of Asthma in a Patient With Diffuse Panbronchiolitis (DPB) After Macrolide Therapy

Diffuse panbronchiolitis (DPB), an important cause of progressive obstructive lung disease in the Far East, is a distinctive sinobronchial syndrome with characteristic radiologic and histologic features. Asthma is a chronic inflammatory disease characterized by airway narrowing. The major inflammatory cells involved in the pathogenesis of asthma are type 2 helper T (Th2) cells, eosinophils, and mast cells. The authors’ patient was diagnosed with DPB and asthma. Although macrolide therapy led to the disappearance of the radiologic abnormalities indicating centrilobular nodular lesions, the respiratory symptoms and pulmonary function worsened. Administration of inhaled corticosteroids improved the respiratory symptoms and pulmonary function. To the authors’ knowledge, no case of DPB with asthma has been reported in the English-language literature.     

FIZZ1 Plays a Crucial Role in Early Stage Airway Remodeling of OVA-Induced Asthma

The aim of this study was to elucidate the role of Found in Inflammatory Zone 1 (FIZZ1, also known as RELM-α or resistin-like molecule-α) in airway remodeling in asthma. We used a rat model of ovalbumin (OVA) sensitization and challenge to induce lung inflammation and remodeling. Expression of α -SMA in the lungs of OVA-treated rats was significantly elevated in the peribronchial regions compared with control saline-treated animals. Expression of FIZZ1 mRNA in alveolar epithelial type II cells (AECII) isolated from OVA-treated animals was higher than in control animals. Forced expression of recombinant FIZZ1 in rat-1 lung fibroblast cell line enhanced production of collagen type I and α -SMA compared with control transfected cells. These results suggest that FIZZ1 can induce fibroblasts to express markers of myofibroblast differentiation such as α -SMA and collagen type I, which are characteristic of early stages of airway remodeling seen in asthma.