Cyclic nucleotide regulation of store-operated Ca2+ influx in airway smooth muscle
Cyclic nucleotide regulation of store-operated Ca2+ influx in airway smooth muscle
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DOI：
10.1152/ajplung.00188.2005
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发表时间：
2006-02-01
影响因子：
4.9
通讯作者：
Pabelick, CM
中科院分区：
文献类型：
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作者：
Ay, B;Iyanoye, A;Pabelick, CM
肌浆网 (SR) Ca2+ 释放和质膜 Ca2+ 流入是气道平滑肌 (ASM) 细胞内 Ca2+ ([Ca2+](i)) 调节的关键。 SR Ca2+ 耗尽会通过钙池操纵的 Ca2+ 通道 (SOCC) 触发流入，以补充 SR。几种临床相关的支气管扩张剂通过环核苷酸（cAMP、cGMP）介导其作用。我们研究了环核苷酸对酶解猪 ASM 细胞中 SOCC 介导的 Ca2+ 内流的影响。 SR Ca2+ 被 0 细胞外 Ca2+ ([Ca2+](i))、硝苯地平和 KCl 中的 1 μM 环吡嗪酸耗尽（防止 Ca2+ 通过 L 型和 SOCC 通道流入）。然后通过重新引入 [Ca2+](o) 激活 SOCC，并通过多种技术进行表征。我们通过在 1 μM 异丙肾上腺素或 100 μM 二丁酰 cAMP（细胞渗透性 cAMP 类似物）存在下激活 SOCC 来检查 cAMP 对 SOCC 的影响，而我们使用 1 μM (Z)-1-[N-(2-氨乙基)-N-(2-氨乙基)氨基]diazen-1-ium-1,2-二醇 (DETA-NO 一氧化氮供体）或 100 μM 8-溴鸟苷 3', 5'-环单磷酸（可渗透细胞的 cGMP 类似物）。通过分别预暴露于 100 nM KT-5720 和 500 nM KT-5823 来检查蛋白激酶 A 和 G 的作用。 SOCC 介导的 Ca2+ 流入取决于 SR Ca2+ 消耗的程度，对 Ni2+ 和 La3+ 敏感，但对电压门控流入通道的抑制剂不敏感。 cAMP 和 cGMP 主要通过各自的蛋白激酶有效抑制 Ca2+ 内流。此外，蛋白激酶 G 的 cAMP 交叉激活有助于 SOCC 抑制。这些数据表明，由 SR Ca2+ 消耗引发的 ASM 中 Ni2+/La3+ 敏感的 Ca2+ 流入被 cAMP 和 cGMP 通过蛋白激酶机制抑制。这种抑制可能在 ASM 对临床相关药物（例如 β 激动剂与一氧化氮）的支气管扩张反应中发挥作用。
Sarcoplasmic reticulum (SR) Ca2+ release and plasma membrane Ca2+ influx are key to intracellular Ca2+ ([Ca2+](i)) regulation in airway smooth muscle (ASM). SR Ca2+ depletion triggers influx via store-operated Ca2+ channels (SOCC) for SR replenishment. Several clinically relevant bronchodilators mediate their effect via cyclic nucleotides (cAMP, cGMP). We examined the effect of cyclic nucleotides on SOCC-mediated Ca2+ influx in enzymatically dissociated porcine ASM cells. SR Ca2+ was depleted by 1 mu M cyclopiazonic acid in 0 extracellular Ca2+ ([Ca2+](i)), nifedipine, and KCl (preventing Ca2+ influx through L-type and SOCC channels). SOCC was then activated by reintroduction of [Ca2+](o) and characterized by several techniques. We examined cAMP effects on SOCC by activating SOCC in the presence of 1 mu M isoproterenol or 100 mu M dibutryl cAMP (cell-permeant cAMP analog), whereas we examined cGMP effects using 1 mu M (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2- diolate (DETA- NO nitric oxide donor) or 100 mu M 8-bromo-guanosine 3', 5'-cyclic monophosphate (cell-permeant cGMP analog). The role of protein kinases A and G was examined by preexposure to 100 nM KT-5720 and 500 nM KT-5823, respectively. SOCC-mediated Ca2+ influx was dependent on the extent of SR Ca2+ depletion, sensitive to Ni2+ and La3+, but not inhibitors of voltage-gated influx channels. cAMP as well as cGMP potently inhibited Ca2+ influx, predominantly via their respective protein kinases. Additionally, cAMP cross-acti\vation of protein kinase G contributed to SOCC inhibition. These data demonstrate that a Ni2+/La3+ -sensitive Ca2+ influx in ASM triggered by SR Ca2+ depletion is inhibited by cAMP and cGMP via a protein kinase mechanism. Such inhibition may play a role in the bronchodilatory response of ASM to clinically relevant drugs ( e. g., beta-agonists vs. nitric oxide).