生理学报Acta Physiologica Sinica, April

研究论文

蛋白激酶C对大鼠支气管平滑肌KV通道的影响

刘先胜*, 徐永健, 张珍祥, 倪望, 陈仕新

华中科技大学同济医学院附属同济医院呼吸内科, 武汉 430030

摘要: 用全细胞膜片钳、 Western印迹法和逆转录-PCR技术, 观察蛋白激酶C (protein kinase C, PKC)对大鼠支气管平滑肌细胞(bronchial smooth muscle cells, BSMCs)电压依赖性延迟整流钾通道(KV)活性及其亚型KV1.5表达的影响。结果为: (1) PKC激活剂豆蔻酰佛波醇乙酯(phorbol 12-myristate 13-acetate, PMA)显著抑制急性分离大鼠BSMCs的 KV通道电流, 该效应被PKC阻断剂Ro31-8220显著抑制; (2)PMA显著抑制体外培养大鼠BSMCs的KV1.5 mRNA和蛋白质的表达, 该效应被Ro31-8220显著抑制。 上述观察结果提示, PKC活化可抑制大鼠BSMCs的KV通道电流活性, 下调KV1.5亚型的表达水平。

关键词: 支气管; 平滑肌细胞; 电压依赖性延迟整流钾通道; 蛋白激酶C

中图分类号: Q47; R56

Effect of protein kinase C on KV channel in rat bronchial smooth muscle

LIU Xian-Sheng*, XU Yong-Jian, ZHANG Zhen-Xiang, NI Wang, CHEN Shi-Xin

Department of Respiratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030

Abstract: The effect of protein kinase C (PKC) signaling pathway on the activity of voltage-dependent delayed rectifier potassium channel (KV) and the expression of KV isoform KV1.5 in rat bronchial smooth cells (BSMCs) were investigated with whole-cell patch clamp, Western-blot and RT-PCR techniques. The results showed: (1) phorbol 12-myristate 13-acetate (PMA), a PKC activator, caused a significant inhibition of KV channel currents in rat BSMCs. The inhibition was partly abolished by Ro31-8220, a PKC inhibitor. (2) PMA caused a significant suppression of the expression of KV1.5 mRNA and protein in rat BSMCs. These effects were attenuated by Ro31-8220. The results suggest that in rat BSMCs PKC activation inhibits KV currents and down-regulates the expression of KV1.5.

Key words: bronchus; smooth muscle cells; voltage-dependent delayed rectifier potassium channel; protein kinase C