Stimulatory Actions of Caffeic Acid Phenethyl Ester, a Known Inhibitor of NF-κB Activation, on Ca2+-activated K+ Current in Pituitary GH3 Cells*
Stimulatory Actions of Caffeic Acid Phenethyl Ester, a Known Inhibitor of NF-κB Activation, on Ca2+-activated K+ Current in Pituitary GH3 Cells*
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咖啡酸苯乙酯（一种已知的 NF-κB 激活抑制剂）对垂体 GH3 细胞中 Ca2+ 激活的 K+ 电流的刺激作用*
DOI：
10.1074/jbc.m400356200
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发表时间：
2004
影响因子：
4.8
通讯作者：
Sheng
中科院分区：
文献类型：
--
作者：
Ming;Su;Mei‐Han Huang;Sheng
咖啡酸苯乙酯（CAPE）是一种从蜂箱中提取的酚类抗氧化剂，是核转录因子NF-κB活化的抑制剂。在垂体GH 3细胞上研究了它对离子电流的影响。该化合物以浓度依赖性方式增加Ca 2+激活的K+电流（IK（Ca）），EC 50值为14 ± 2 μm。然而，在用2，2 ′-偶氮-双-（2-脒基丙烷）盐酸盐（100 μm）或叔丁基过氧化氢（1 mm）预孵育的GH 3细胞中，CAPE诱导的IK（Ca）刺激的幅度被减弱。CAPE（50 μm）轻微抑制电压依赖性L型Ca ~（2+）电流。在由内向外的结构中，CAPE（20 μm）作用于离体膜片钳的胞内面，可增强大电导Ca ~（2+）激活K ~+（BKCa）通道的活性，而对单通道电导无影响。在CAPE（20 μm）增加BKCa通道活性后，随后应用去甲二氢愈创木酸（20 μm）不会进一步增加通道活性。CAPE刺激的通道活性依赖于膜电位。CAPE还可增加BKCa通道对Ca ~（2+）的敏感性。其打开概率的增加可能主要涉及平均关闭时间的减少。在电流钳条件下，CAPE使膜电位超极化，减少动作电位的放电。对这些通道的刺激作用可能部分有助于该化合物影响神经元或神经内分泌细胞功能活动的潜在机制。在将其反应归因于NF-κB活化时必须谨慎。
Caffeic acid phenethyl ester (CAPE), a phenolic antioxidant derived from the propolis of honeybee hives, is known to be an inhibitor of activation of nuclear transcript factor NF-κB. Its effects on ion currents have been investigated in pituitary GH3 cells. This compound increased Ca2+-activated K+ current (IK(Ca)) in a concentration-dependent manner with an EC50 value of 14 ± 2 μm. However, the magnitude of CAPE-induced stimulation of IK(Ca) was attenuated in GH3 cells preincubated with 2,2′-azo-bis-(2-amidinopropane) hydrochloride (100 μm) or t-butyl hydroperoxide (1 mm). CAPE (50 μm) slightly suppressed voltage-dependent L-type Ca2+ current. In inside-out configuration, CAPE (20 μm) applied to the intracellular face of the detached patch enhanced the activity of large conductance Ca2+-activated K+ (BKCa) channels with no modification in single-channel conductance. After BKCa channel activity was increased by CAPE (20 μm), subsequent application of nordihydroguaiaretic acid (20 μm) did not further increase the channel activity. CAPE-stimulated channel activity was dependent on membrane potential. CAPE could also increase Ca2+ sensitivity of BKCa channels in these cells. Its increase in the open probability could primarily involve a decrease in the mean closed time. In current-clamp conditions, CAPE hyperpolarized the membrane potential and reduced the firing of action potentials. The stimulatory effects on these channels may partly contribute to the underlying mechanisms through which this compound influences the functional activities of neurons or neuroendocrine cells. Caution has to be used in attributing its response in the activation of NF-κB.
咖啡酸苯乙酯刺激人体抗氧化反应元件介导的 NAD(P)H:醌氧化还原酶 (NQO1) 基因的表达。
影响因子：
11.2
作者：
Jaiswal,AK;Venugopal,R;Mucha,J;Carothers,AM;Grunberger,D
通讯作者：
Grunberger,D