香烟提取物活化大鼠支气管平滑肌细胞蛋白激酶C亚型及下调钾通道BK_(Ca)、Kv1.5表达(英文)  

Cigarette smoke extract activates PKC isoforms and down-regulates the expressions of potassium channels BK_(Ca) and Kv1.5 in rat bronchial smooth muscle cells

作　　者：叶红[1] 马万里[2] 金肆[1] 刘声远[1] 王迪浔[1] 胡清华[1] 

机构地区：[1]华中科技大学同济医学院病理生理学系,卫生部呼吸系疾病重点实验室,武汉430030 [2]华中科技大学同济医学院附属协和医院呼吸内科,武汉430030

出　　处：《生理学报》2008年第6期709-714,共6页Acta Physiologica Sinica

基　　金：supported by the National Natural Science Foundation of China (No. 30570793, 30770943, 30770648, 30670926)

摘　　要：大电导的钙活化钾通道(large-conductance calcium-activated potassium channel,BKCa)和电压依赖性钾通道Kv1.5在气道高反应性的发生机制中具有重要作用。已知吸烟可致气道高反应,但钾通道的变化在其发病中的作用尚需进一步阐明。本文旨在研究香烟提取物(cigarette smoke extract,CSE)对培养的大鼠支气管平滑肌细胞(bronchial smooth muscle cells,BSMCs)钾通道BKCa和Kv1.5表达的直接作用,以及蛋白激酶C(protein kinase C,PKC)在其中的作用。实验采用原代培养大鼠BSMCs,用5%CSE刺激,免疫印迹检测PKC亚型的表达和转位,半定量RT-PCR、免疫印迹实验检测BKCa和Kv1.5的mRNA和蛋白表达,然后用PKC抑制剂BIM和G?e6983与CSE共作用,检测其对BKCa和Kv1.5的mRNA和蛋白表达的影响。结果显示,5%CSE使PKCε、η、θ发生明显的膜转位,并使BKCa和Kv1.5的蛋白和mRNA表达明显降低;选择性PKC抑制剂BIM或G?e6983与CSE共同作用,均可使BKCa和Kv1.5的蛋白和mRNA表达部分恢复。上述结果提示,CSE可引起BSMCs的BKCa和Kv1.5表达下调,PKCε、η、θ参与其信号转导。Large-conductance calcium-activated potassium channel （BKca） and voltage-gated potassium channel Kv1.5 play an important role in the pathogenesis of bronchial hyperresponsiveness （BHR）. It is known that cigarette smoke can induce BHR, however, the role of BKca and Kv 1.5 expression in it remains to be further elucidated. The purpose of the present study was to investigate the direct effects of cigarette smoke extract （CSE） on B Kca and Kv 1.5 expression, and the role of protein kinase C （PKC） isoforms activation in primary cultured rat bronchial smooth muscle cells （BSMCs）. Primarily cultured rat BSMCs were treated with 5% CSE, the expression and translocation of PKC isoforms were measured by Western blot, and the mRNA and protein levels of BKca and Kv 1,5 α-subunits were determined by semi-quantitative RT-PCR and Western blot, respectively. The results showed that 5% CSE induced the translocation of PKCε, PKCη, PKCθ from soluble fraction to particulate fraction, and reduced mRNA and protein expressions of BKCa and Kv1.5 α-subunits. The decreased expression of potassium channels was partly restored by PKC inhibitor, BIM or G6e6983. In summary, CSE may activate PKC isoforms ε, η, θ, thereby down-regulate the expressions of BKCa and Kv1.5 in BSMCs.

关 键 词：支气管 平滑肌 香炯提取物 钾通道 蛋白激酶C 

分 类 号：R363[医药卫生—病理学]