Therapy for bronchial asthma by regulating a small G protein as a targeting molecule

通过调节小G蛋白作为靶向分子治疗支气管哮喘

基本信息

批准号：
17590785
负责人：
KUME Hiroaki
金额：
$ 2.3万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590785/
关键词：
Rho β-adrenergic receptors S1P eosinophil airway smooth muscle airway hyperresponsiveness airway remodeling oxidative stress Rho-kinase 細胞増殖 Ca^<2+>感受性スタチン気管支喘息好酸球浸潤 IL-5 ケモカイン G_i

项目摘要

This project was designed to determine whether Rho, a small G protein, is useful to therapy for bronchial asthma as a targeting molecule. Since Rho, and it's effector enzyme, Rho-kinase, have functional relevance for Ca^<2+> sensitization, cell proliferation, cell migration, and cytoskeleton, the Rho/Rho-kinase pathway may related to eosinophil infiltration, airway hyperresponsiveness, β-adrenergic desensitization, and airway remodeling which are pathophysiogy of bronchial asthma. Isometric tension and concentrations of intracellular Ca^<2+> [Ca^<2+>]_i were simultaneously measured using fura-2 loaded tracheal smooth muscle in guinea pigs. When isoproterenol, a β-adrenergic receptor agonist, was cumulatively applied to the tissues precontracted with 1 μM methacholine, isoproterenol caused an inhibition of contraction induced by methacholine with reducing [Ca^<2+>]_i in a concentration-dependent manner. However, a reduction in tension was greater than that in [Ca^<2+>]_i in the inhibito … More ry action of isoproterenol, indicating that β-adrenergic action antagonizes not only Ca^<2+> mobilization but also Ca^<2+> sensitization. Loss of the latter process leads to dysfunction of β-adrenergic receptors. Hydrogen peroxide, an indicator of oxidative stress, generated force with elevating [Ca^<2+>]_i. However, Y-27632, an inhibitor of Rho-kinase, inhibited contraction by hydrogen peroxide without reducing [Ca^<2+>]_i, indicating that airflow limitation by oxidative stress is associated with activation of Rho-kinase. After exposure to sphingosine 1-phosphate (S1P), a bioactive lysophospholipid released from inflammatory cells, methacholine-induced contraction was markedly enhanced without elevating [Ca^<2+>]_i, and Y-27632 antagonized the augmented responsiveness to methacholine by pretreatment with S1P. Airway hyperresponsiveness is mediated by Rho-induced Ca^<2+> sensitization via inactivation of myosin phosphatase. In cultured human bronchial smooth muscle cells, cell proliferation and DNA synsethsis induced by FBS was inhibited by simvastatin, a HMG-CoA reductase, and Y-27632. Rho/Rho-kinase activity regulated by the mevalonate pathways in cholesterol synthesis contributes to cell proliferation related to airway remodeling. In sensitize mice, antigen challenges caused eosinophil infiltration to airways and an increase in the lung resistance in response to methacholine. Administration of Y-27632 and fasudil, another inhibitor of Rho-kinase, inhibited eosinophilia and augmented lung resistance by antigens challenges. The Rho/Rho-kinase pathway is involved in the airway inflammation by eosinophil recruitment.In conclusion, inhibiting the Rho/Rho-kinase pathway may have therapeutic potential for bronchial asthma. Less

该项目旨在确定Rho（一种小的G蛋白）是否可用于对支气管哮喘作为靶向分子的治疗。自从Rho及其效应酶（Rho-激酶）与CA^<2+>敏感性，细胞增殖，细胞迁移和细胞骨架具有功能相关性，Rho/Rho-kinase途径可能与嗜酸性粒细胞浸润有关哮喘。在豚鼠中，仅使用Fura-2加载的气管平滑肌来测量等距内Ca^<2+> [Ca^<2+>] _ I的等距张力和浓度。当异丙肾上腺素（一种β-肾上腺素的接收器激动剂）累积地应用于用1μM方法的组织累积的组织时，异丙肾上腺素引起的抑制方法是通过浓度依赖性的方法来减少[Ca^<2+>] _ i的降低[ca^<2+>] _ i的收缩。然而，张力的降低大于抑制性的[Ca^<2+>] _ I中的张力……异丙肾上腺素的更多作用，表明β-肾上腺素能的作用不仅拮抗Ca^<2+>动员，而且拮抗Ca^<2+>敏感性。后一个过程的丧失会导致β-肾上腺素受体的功能障碍。过氧化氢是氧化应激的指标，产生了升高[Ca^<2+>] _ I的力。然而，Rho-激酶的抑制剂Y-27632抑制了过氧化氢在不减少[Ca^<2+>] _ I的情况下抑制收缩，这表明氧化应激限制的气流限制与Rho-Ikinase的激活有关。暴露于1-磷酸盐（S1P）后，一种从炎性细胞释放的生物活性溶血磷脂，方法明显增强了方法，而没有[Ca^<2+>] _ I，而Y-27632抑制了对方法对方法的增强响应能力，而Y-27632通过对方法的增强响应能力。气道高反应性是通过Rho诱导的Ca^<2+>敏感性介导的。在培养的人支气管平滑肌细胞中，FBS诱导的细胞增殖和DNA依sems被HMG-COA还原剂和Y-27632抑制。由胆固醇合成中甲戊酸酯途径调节的Rho/Rho-激酶活性有助于与气道重塑有关的细胞增殖。在敏感性小鼠中，抗原挑战导致嗜酸性粒细胞浸润对气道，并响应甲基苯胺的肺耐药性增加。 Y-27632和另一种Rho-激酶抑制剂Fasudil的给药抑制了嗜酸性粒细胞增强和抗原挑战的增强肺抵抗。 Rho/Rho激酶途径参与嗜酸性粒细胞募集的气道注射。总而言，抑制Rho/Rho-kinase途径可能具有支气管哮喘的治疗潜力。较少的