Protein disulfide-isomerase mediates delivery of nitric oxide redox derivatives into platelets
Protein disulfide-isomerase mediates delivery of nitric oxide redox derivatives into platelets
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DOI：
10.1042/bj20061146
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发表时间：
2007-04-15
影响因子：
4.1
通讯作者：
Gordge, Michael P.
中科院分区：
文献类型：
--
作者：
Bell, Susannah E.;Shah, Chirag M.;Gordge, Michael P.
s -亚硝基硫醇类化合物是NO信号转导的重要介质，可以产生多种NO的氧化还原衍生物：亚硝基阳离子（NO+）、硝基阴离子（NO-）和NO中心点自由基。几种酶和转运体参与了s -亚硝基硫醇在细胞内传递NO的过程。在本研究中，我们研究了GPx（谷胱甘肽过氧化物酶）、L-AT （l -氨基酸转运蛋白）系统和PDI（蛋白质二硫异构酶）在将NO氧化还原衍生物输送到人血小板中的作用。在暴露于NO氧化还原衍生物（s -亚硝基谷胱甘肽、安吉利氏盐和二乙胺NONOate）供体之前，用GPx、L-AT和PDI抑制剂处理洗净的人血小板。通过cGMP积累和DAF-FM（4-氨基-5-甲基氨基-2'7'-二氟荧光素）荧光监测no相关信号快速传递到血小板。所有NO氧化还原供体在靶血小板中均产生cGMP反应和DAF-FM荧光。PDI抑制以剂量依赖的方式阻断NO的递送。相比之下，抑制GPx和L-AT对no相关信号传导的影响很小。因此，PDI活性是将所有一氧化氮氧化还原衍生物供体的一氧化氮相关信号快速传递到血小板所必需的。GPx和L-AT系统在本研究中使用的化合物的快速NO信号传导中似乎不重要。然而，这并不排除细胞暴露于其他s -亚硝基硫醇化合物（如s -亚硝基半胱氨酸）时的可能作用。这些结果进一步强调了PDI在介导广泛的no相关信号的作用中的重要性。
S-nitrosothiol compounds are important mediators of NO signalling and can give rise to various redox derivatives of NO: nitrosonium cation (NO+), nitroxyl anion (NO-) and NO center dot radical. Several enzymes and transporters have been implicated in the intracellular delivery of NO from S-nitrosothiols. In the present study we have investigated the role of GPx (glutathione peroxidase), the L-AT (L-amino acid transporter) system and PDI (protein disulfide-isomerase) in the delivery of NO redox derivatives into human platelets.Washed human platelets were treated with inhibitors of GPx, L-AT and PDI prior to exposure to donors of NO redox derivatives (S-nitrosoglutathione, Angeli's salt and diethylamine NONOate). Rapid delivery of NO-related signalling into platelets was monitored by cGMP accumulation and DAF-FM (4-amino-5-methylamino-2'7'-difluorofluorescein) fluorescence.All NO redox donors produced both a cGMP response and DAF-FM fluorescence in target platelets. NO delivery was blocked by inhibition of PDI in a dose-dependent manner. In contrast, inhibition of GPx and L-AT had only a minimal effect on NO-related signalling.PDI activity is therefore required for the rapid delivery into platelets of NO-related signals from donors of all NO redox derivatives. GPx and the L-AT system appeared to be unimportant in rapid NO signalling by the compounds used in the present study. This does not, however, exclude a possible role during exposure of cells to other S-nitrosothiol compounds, such as S-nitrosocysteine. These results further highlight the importance of PDI in mediating the action of a wide range of NO-related signals.