Stable expression and characterization of human PN1 and PN3 sodium channels
Stable expression and characterization of human PN1 and PN3 sodium channels
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DOI：
10.3109/713745174
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发表时间：
2003-09-01
期刊：
影响因子：
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通讯作者：
Barsoumian, EL
中科院分区：
文献类型：
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作者：
Akiba, I;Seki, T;Barsoumian, EL
炎性和神经性疼痛中的伤害性感受转导涉及外周表达的电压门控钠通道，例如河豚毒素（TTX）敏感性PN1和TTX抗性PN3。我们使用诱导型表达载体在中国仓鼠卵巢（CHO）细胞中产生了稳定表达人PN1和PN3钠通道的重组细胞系。PN1和PN3的cDNA分别从人肾上腺和心脏的poly（A）（+）RNA中分离。重组人PN1电流表现出快速的激活和失活动力学，并被TTX阻断，半最大抑制浓度（IC 50）为32.6 nM。在稳定转染子中表达的人PN3通道显示具有缓慢失活动力学的TTX抗性内向电流。TTX的IC 50值为73.3 μ M。与PN1通道相比，PN3通道激活的电压依赖性向去极化方向移动。利多卡因和美西律对PN1和PN3通道表现出紧张性和使用依赖性阻滞。PN1通道比PN3通道更容易受到美西律的抑制。这些结果表明，表达人PN1和PN3钠通道的稳定转染子将是定义钠通道阻断剂的亚型选择性的有用工具。
Nociceptive transduction in inflammatory and neuropathic pain involves peripherally expressed voltage-gated sodium channels, such as tetrodotoxin (TTX)- sensitive PN1 and TTX-resistant PN3. We generated recombinant cell lines stably expressing the human PN1 and PN3 sodium channels in Chinese hamster ovary (CHO) cells using inducible expression vectors. The PN1 and PN3 cDNAs were isolated fromhuman adrenal gland and heart poly(A)(+) RNAs, respectively. The recombinant human PN1 currents exhibited rapid activation and inactivation kinetics and were blocked by TTX with a half-maximal inhibitory concentration (IC50) of 32.6 nM. The human PN3 channel expressed in stable transfectants showed TTX-resistant inward currents with slow inactivation kinetics. The IC50 value for TTX was 73.3 muM. The voltage-dependence of activation of the PN3 channel was shifted to the depolarizing direction, compared to that of the PN1 channel. Lidocaine and mexiletine exhibited tonic and use-dependent block of PN1 and PN3 channels. The PN1 channel was more susceptible to inhibition by mexiletine than PN3. These results suggest that stable transfectants expressing the human PN1 and PN3 sodium channels will be useful tools to define subtype selectivity for sodium channel blockers.