Role of Rho in the pathophysiology of bronchial asthma

Rho 在支气管哮喘病理生理学中的作用

基本信息

批准号：
15590805
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：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

This study was designed to determine involvement of Rho in the pathophysiology of bronchial asthma such as bronchial hyperreactivity, β-adrenergic desensitization, and airway remodeling. After exposure of the fura-2 loaded strip of tracheal smooth muscle to sphingosine 1-phosphate (S1IP,10 μM) for more than 15 min, contraction by methacholine(MCh), a muscarinic receptor agonist, was markedly augmented in a time-dependent fashion. However, concentration of intracellular Ca^<2+>([Ca^<2+>]i) by MCh was not affected. The increased response to MCh (bronchial hyperreactivity) by S1P was antagonized in the presence of 0.01-1 μM Y-27632, a selective inhibitor of Rho-kinase, in a concentration-dependent fashion. Pre exposure to pertussis toxin over 6 hours also prohibited the increased response to MCh by S1P. Next, after exposure of the tissues to S1P (<1 μM) for an equivalent time, the inhibitory effect of isoproterenol (ISO), a β-adrenergic receptor agonist, against MCh-induced contraction wa … More s markedly attenuated without no change in [Ca^<2+>]i. The reduced responsiveness to ISO (desensitization of β-adrenergic receptors) by S1P was inhibited by Y-27632 in a concentration-dependent fashion. Pre exposure to pertussis toxin over an equivalent time also prohibited the reduced response to ISO by S1P. On the other hand, after repeated exposure to ISO every 30 min, response to ISO was gradually attenuated with an increase in [Ca^<2+>]i. This reduced responsiveness to ISO was inhibited in the presence of verapamil, a selective antagonist of voltage-dependent Ca^<2+> channels. In cultured bronchial smooth muscle cells, S1P phosphorylated myosin phosphatase targeting protein (MYPT1) that is a specific protein in myosin phosphatase affected by Rho-kinase. Proliferation of the bronchial smooth muscle cells (airway remodeling) was reduced by Y-27632 in a concentration-dependent fashion. In conclusion, Rho/Rho-kinase processes play an important role in the pathophysiology of bronchial asthma. Less

这项研究旨在确定RHO参与支气管哮喘的病理生理，例如支气管高反应性，β-肾上腺素脱敏和气道重塑。在将气管平滑肌的Fura-2载液条暴露于1-磷酸盐（S1IP，10μM）中，持续15分钟以上，以时间依赖性的方式显着增强了毒蕈碱受体激动剂的甲氧醇（MCH）（MCH）（MCH）。但是，MCH受到MCH的细胞内Ca^<2+>（[Ca^<2+>] i）的浓度没有影响。在0.01-1μmy-27632的存在下，S1P对MCH（支气管高反应性）的反应增加，这是一种浓度依赖性的Rho-kinase的选择性抑制剂。在6小时内暴露于百日咳毒素之前，也禁止S1P对MCH的反应增加。接下来，将时间曝光在同等时间内暴露于S1P（<1μm）之后，异丙肾上腺素（ISO）的抑制作用，一种β-肾上腺素能受体激动剂，对MCH诱导的收缩wa…在[Ca^<2+>] i的情况下更明显地减弱而没有变化。 Y-27632以浓度依赖性的方式抑制了S1P对ISO（β-肾上腺素能受体脱敏）的反应性降低。在同等时间内暴露于百日咳毒素的情况下，S1P也禁止对ISO的响应减少。另一方面，在每30分钟反复接触ISO后，对ISO的反应逐渐减弱，[Ca^<2+>] i。在维拉帕米（Verapamil）存在的情况下，对ISO的反应性降低是电压依赖性Ca^<2+>通道的选择性拮抗剂的存在。在培养的支气管平滑肌细胞中，S1P磷酸化的肌球蛋白磷酸酶靶向蛋白（MYPT1）是受Rho-激酶影响的肌球蛋白磷酸酶中的特定蛋白。 Y-27632以浓度依赖性方式减少了支气管平滑肌细胞（气道重塑）的增殖。总之，Rho/Rho-激酶过程在支气管哮喘的病理生理学中起重要作用。较少的