Redox mechanism of S-nitrosothiol modulation of neuronal CaV3.2 T-type calcium channels.
Redox mechanism of S-nitrosothiol modulation of neuronal CaV3.2 T-type calcium channels.
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DOI：
10.1007/s12035-013-8493-8
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发表时间：
2013-10
影响因子：
5.1
通讯作者：
Todorovic, Slobodan M.
中科院分区：
文献类型：
--
作者：
Lee, Jeonghan;Nelson, Michael T.;Rose, Kirstin E.;Todorovic, Slobodan M.
背根神经节（DRG）中的T型钙通道在调节神经元兴奋性方面具有中枢功能，并与包括疼痛在内的感觉加工有关。以前的研究已经暗示氧化还原剂控制T通道活性;然而，所涉及的机制尚未完全理解。本研究记录了急性分离的幼年大鼠DRG神经元的T型钙电流，并探讨了S-亚硝基硫醇（SNOs）对CaV3.2 T型通道的调节机制。我们发现，细胞外应用S-亚硝基谷胱甘肽（GSNO）和S-亚硝基-N-乙酰青霉胺（SNAP）迅速降低T型电流的幅度。GSNO不影响T型通道稳态失活的电压依赖性和宏观电流动力学。用N-乙基马来酰亚胺（一种不可逆的烷化剂）预处理细胞可消除GSNO的作用，但用1H-（1，2，4）恶二唑并（4，3-a）喹喔啉-1-酮（ODQ）（一种特异性可溶性鸟苷酸环化酶抑制剂）预处理细胞则不能消除GSNO的作用，这表明GSNO对T型通道上假定的细胞外巯基残基具有潜在作用。野生型CaV3.2通道或四重Cys-Ala突变体在人胚肾（HEK）细胞中的表达揭示了通道的细胞外表面上的重复序列I和II中的Cys残基是GSNO抑制通道所需的。我们建议，在体内的SNO相关分子可能会导致T-型通道依赖的感觉神经元和中枢神经系统（CNS）在生理和病理条件下，如神经元缺血/缺氧的神经元兴奋性的改变。
T-type calcium channels in the dorsal root ganglia (DRG) have a central function in tuning neuronal excitability and are implicated in sensory processing including pain. Previous studies have implicated redox agents in control of T-channel activity; however, the mechanisms involved are not completely understood. Here we recorded T-type calcium currents from acutely dissociated DRG neurons from young rats and investigated the mechanisms of CaV3.2 T-type channel modulation by S-nitrosothiols (SNOs). We found that extracellular application of S-nitrosoglutathione (GSNO) and S-nitroso-N-acetyl-penicillamine (SNAP) rapidly reduced T-type current amplitudes. GSNO did not affect voltage-dependence of steady-state inactivation and macroscopic current kinetics of T-type channels. The effects of GSNO were abolished by pretreatment of the cells with N-ethylmaleimide, an irreversible alkylating agent, but not by pretreatment with 1H-(1,2,4) oxadiazolo (4,3-a) quinoxalin-1-one (ODQ), a specific soluble guanylyl cyclase inhibitor, suggesting a potential effect of GSNO on putative extracellular thiol residues on T-type channels. Expression of wild type CaV3.2 channels or a quadruple Cys-Ala mutant in human embryonic kidney (HEK) cells revealed that Cys residues in repeats I and II on the extracellular face of the channel were required for channel inhibition by GSNO. We propose that SNO-related molecules in vivo may lead to alterations of T-type channel-dependent neuronal excitability in sensory neurons and in the central nervous system (CNS) in both physiological and pathological conditions such as neuronal ischemia/hypoxia.
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影响因子：
5.5
作者：
Carabelli, V.;Marcantoni, A.;Carbone, E.
通讯作者：
Carbone, E.
影响因子：
2.5
作者：
Todorovic, SM;Lingle, CJ
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Lingle, CJ
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作者：
CARBONE, E;LUX, HD
通讯作者：
LUX, HD
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作者：
Smith, SD;Wheeler, MA;Weiss, RM
通讯作者：
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作者：
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通讯作者：
Nargeot, J