间尼索地平对5-羟色胺诱导的大鼠肺动脉平滑肌细胞增殖中Ca^(2+)/CaM/CaN通路的影响

Effect of m-nisoldipine on the Ca^(2+)/CaM/CaN signal pathway in 5-HT-induced proliferation of rat PASMCs

探讨Ca2+/CaM/CaN信号通路在5-羟色胺(5-HT)诱导的大鼠肺动脉平滑肌细胞(PASMCs)增殖中的作用以及间尼索地平(m-Nis)对此的影响。采用细胞培养、噻唑蓝(MTT)比色检测、激光共聚焦显微镜及反转录聚合酶链反应(RT-PCR)等方法,研究5-HT(1μmol·L-1)对大鼠PASMCs细胞增殖的影响以及m-Nis对此的抑制作用,并通过检测m-Nis对5-HT诱导的大鼠PASMCs增殖中Ca2+/CaM/CaN通路的影响深入探讨其作用机制。结果显示,5-HT(1μmol·L-1)可明显诱导大鼠PASMCs增殖(P<0.01),m-Nis对此有明显的抑制作用,并呈现一定的浓度依赖性(P<0.05或P<0.01);另外,m-Nis还明显抑制了5-HT引起的[Ca2+]i的升高(P<0.01)、CaM和CaNmRNA的表达以及CaN活性的升高(P<0.05或P<0.01)。结果表明,Ca2+/CaM/CaN信号通路在5-HT诱导的大鼠PASMCs增殖中起重要作用,m-Nis抗5-HT诱导的增殖作用可能与抑制[Ca2+]i增高从而阻断了Ca2+/CaM/CaN信号通路有关。

This study is to explore the activation of the Ca^2＋/CaM/CaN signal pathway in 5-HT-induced proliferation of rat pulmonary artery smooth muscle cells （PASMCs） and the inhibitory effect of m-nisoldipine （m-Nis） on this pathway. PASMCs were cultured with the explant technique. The proliferation of PASMCs was evaluated by MTT assay. Confocal microscopy was used to measure the change of [Ca^2＋]i. The mRNA expression of CaM and CaN was evaluated by RT-PCR and the activity of CaN was measured according to the instruction of kits. The results of MTT assay suggested that 5-HT （1 μmol·L-1） significantly induced the proliferation of rat PASMCs （P〈0.01）, which was inhibited obviously by m-Nis （P 〈0.05 or P 〈0.01）. Similarly, m-Nis inhibited 5-HT-induced elevation of [Ca^2＋]i （P 〈0.01）. The mRNA expression of CaM, CaN and the activation of CaN were also inhibited by m-Nis at different degrees （P〈 0.05 or P〈 0.01）. Thus, the results of this study suggested that Ca^2＋/CaM/CaN signal pathway played an important role in 5-HT-induced proliferation of rat PASMCs, the inhibition of m-Nis on proliferation of rat PASMCs may be related to the blockage of Ca^2＋/CaM/CaN signal pathway by inhibiting the elevation of [Ca^2＋]i.