U18666A, a cholesterol-inhibition agent, modulates human neuronal nicotinic acetylcholine receptors heterologously expressed in SH-EP1 cell line.
U18666A, a cholesterol-inhibition agent, modulates human neuronal nicotinic acetylcholine receptors heterologously expressed in SH-EP1 cell line.
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U18666A 是一种胆固醇抑制剂，可调节 SH-EP1 细胞系中异源表达的人神经元烟碱乙酰胆碱受体。
DOI：
10.1111/j.1471-4159.2009.05903.x
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发表时间：
2009
影响因子：
4.7
通讯作者：
Wu,Jie
中科院分区：
文献类型：
--
作者：
Zheng,Chao;Wang,Meng-Ya;Liu,Qiang;Wakui,Makoto;Whiteaker,Paul;Lukas,RonaldJ;Wu,Jie
在本研究中，我们使用全细胞膜片钳记录评估了 (3β)-3-[2-(二乙氨基)乙氧基]androst-5-en-17-one 二盐酸盐 (U18666A)（一种胆固醇合成/转运蛋白抑制剂）对在 SH-EP1 细胞系中异源表达的选定人神经元烟碱乙酰胆碱受体 (nAChR) 的影响。结果表明，经过 2 分钟预处理，U18666A 抑制不同 nAChR 亚型，其效力顺序（全细胞峰值电流的 IC50）为：α4β2 (8.0 ± 3.0 nM) > α3β2 (1.7 ± 0.4 μM) > α4β4 (26 ± 7.2 μM) > α7 (> 100 μM)，表明该化合物对 α4β2-nAChR 更具选择性。因此，详细研究了 U18666A 作用于 α4β2-nAChR 的药理学特征和机制。 U18666A 抑制由人类 α4β2-nAChR 响应尼古丁介导的全细胞电流的峰值和稳态分量。在尼古丁诱导的浓度响应曲线中，U18666A 在最大有效激动剂浓度下降低尼古丁诱导的电流，而不影响尼古丁的 EC50 值，表明非竞争性抑制。 U18666A 诱导的 nAChR 功能抑制具有浓度、电压和用途依赖性，表明存在开放通道阻滞。考虑到 2 分钟预处理后 U18666A 的效力增强约 10 000 倍，该化合物也可能通过封闭通道阻滞抑制 α4β2-nAChR。此外，U18666A 诱导的 α4β2-nAChR 抑制不是由受体内吞作用增加或细胞胆固醇改变介导的。这些数据表明 U18666A 是 α4β2-nAChR 的有效拮抗剂，可用作 nAChR 功能表征和药理学分析的工具，以及戒烟的潜在候选者。
In this study, we evaluate the effects of (3β)‐3‐[2‐(diethylamino)ethoxy]androst‐5‐en‐17‐one dihydrochloride (U18666A), a cholesterol synthesis/transporter inhibitor, on selected human neuronal nicotinic acetylcholine receptors (nAChRs) heterologously expressed in the SH‐EP1 cell line using whole‐cell patch‐clamp recordings. The results indicate that with 2‐min pretreatment, U18666A inhibited different nAChR subtypes with a rank‐order of potency (IC50of whole‐cell peak current): α4β2 (8.0 ± 3.0 nM) > α3β2 (1.7 ± 0.4 μM) > α4β4 (26 ± 7.2 μM) > α7 (> 100 μM), suggesting this compound is more selective to α4β2‐nAChRs. Thus, the pharmacological profiles and mechanisms of U18666A acting on α4β2‐nAChRs were investigated in detail. U18666A suppresses both peak and steady state components of whole‐cell currents mediated by human α4β2‐nAChRs in response to nicotine. In nicotine‐induced concentration–response curves, U18666A reduces nicotine‐induced current at maximally effective agonist concentrations without influencing nicotine’s EC50value, suggesting a non‐competitive inhibition. U18666A‐induced inhibition of nAChR function is concentration‐, voltage‐, and use‐dependent, suggesting an open channel block. Taken into consideration of ∼10 000‐fold enhancement of the potency of U18666A after 2‐min pre‐treatment, this compound also likely inhibits α4β2‐nAChRs through a close channel block. In addition, the U18666A‐induced inhibition in α4β2‐nAChRs is not mediated by either increased receptor endocytosis or altered cell cholesterol. These data indicate that U18666A is a potent antagonist of α4β2‐nAChRs and may be useful as a tool in the functional characterization and pharmacological profiling of nAChRs, as well as a potential candidate for smoking cessation.