Cardiac Na+ current regulation by pyridine nucleotides.
Cardiac Na+ current regulation by pyridine nucleotides.
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心脏Na+电流对吡啶核苷酸的调节。
DOI：
10.1161/circresaha.109.197277
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发表时间：
2009-10-09
影响因子：
20.1
通讯作者：
Dudley, Samuel C., Jr.
中科院分区：
文献类型：
--
作者：
Liu, Man;Sanyal, Shamarendra;Gao, Ge;Gurung, Iman S.;Zhu, Xiaodong;Gaconnet, Georgia;Kerchner, Laurie J.;Shang, Lijuan L.;Huang, Christopher L-H.;Grace, Andrew;London, Barry;Dudley, Samuel C., Jr.
甘油-3-磷酸脱氢酶1-样蛋白(GPD1-L)基因突变可降低心肌钠电流(INA)，导致Brugada综合征(BRS)。GPD1-L与参与烟酰胺腺嘌呤二核苷酸依赖的能量代谢的甘油-3-磷酸脱氢酶有80%的氨基酸同源性。因此，我们检测了NAD(H)对人心脏钠通道(NaV1.5)的调节作用。使用稳定表达NaV1.5的HEK293细胞和新生大鼠心肌细胞。在野生型或SCN5A+/−小鼠心脏上评价NADH/NAD+对心律失常风险的影响。280V GPD1-L使细胞内NADH水平增加2.48±0.17倍(P<；0.001)。应用NADH或与A280VGPD1-L共转染组INa下降(分别为对照组的0.48±0.09和0.19±0.04；P<；0.01)，NAD+、白屈菜红碱或超氧化物歧化酶可逆转该作用。蛋白激酶A抑制剂PKAI6-22可阻断由A280V GPD1-L或NADH下调的Na+通道的NAD+拮抗作用。NADH和NAD+的作用分别被佛波醇酯和Forskolin模拟。在野生型小鼠心脏中，细胞内NADH增加与室性心动过速(VT)风险增加相关。在SCN5A+/−小鼠心脏细胞外应用NAD+可降低室性心动过速的风险。我们的结果表明，NaV1.5受吡啶核苷酸的调节，这表明代谢和INA之间存在联系。这种作用需要蛋白激酶C(PKC)的激活，并由氧化应激介导。NAD+可通过激活PKA来阻止这种作用。GPD1-L突变可能通过改变氧化的NAD(H)平衡而下调NaV1.5。
Mutations in glycerol-3-phosphate dehydrogenase 1-like (GPD1-L) protein reduce cardiac Na+ current (INa) and cause Brugada Syndrome (BrS). GPD1-L has >80% amino acid homology with glycerol-3-phosphate dehydrogenase, which is involved in nicotinamide adenine dinucleotide (NAD)-dependent energy metabolism. Therefore, we tested whether NAD(H) could regulate human cardiac sodium channels (Nav1.5). HEK293 cells stably expressing Nav1.5 and rat neonatal cardiomyocytes were used. The influence of NADH/NAD+ on arrhythmic risk was evaluated in wild-type or SCN5A+/− mouse heart. A280V GPD1-L caused a 2.48 ± 0.17-fold increase in intracellular NADH level (P<0.001). NADH application or co-transfection with A280V GPD1-L resulted in decreased INa (0.48 ± 0.09 or 0.19 ±0.04 of control group, respectively; P<0.01), which was reversed by NAD+, chelerythrine, or superoxide dismutase (SOD). NAD+ antagonism of the Na+ channel downregulation by A280V GPD1-L or NADH was prevented by a protein kinase A (PKA) inhibitor, PKAI6–22. The effects of NADH and NAD+ were mimicked by a phorbol ester and forskolin, respectively. Increasing intracellular NADH was associated with an increased risk of ventricular tachycardia (VT) in wild-type mouse hearts. Extracellular application of NAD+ to SCN5A+/− mouse hearts ameliorated the risk of VT. Our results show that Nav1.5 is regulated by pyridine nucleotides, suggesting a link between metabolism and INa. This effect required protein kinase C (PKC) activation and was mediated by oxidative stress. NAD+ could prevent this effect by activating PKA. Mutations of GPD1-L may downregulate Nav1.5 by altering the oxidized to reduced NAD(H) balance.