Basic research on the function of ABC protein in ischemic myocardium

ABC蛋白在缺血心肌中的功能基础研究

• 批准号: 11670676
• 负责人: OTANI Hideo
• 金额: $ 2.3万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670676/
• 关键词: KATP channel; Myocardial ischemia; Kir 6.1; SUR; patch clump; phospholipase C; KATPチャネル; 虚血心筋; Kir6.x; イオンチャネル; K_<ATP>チャネル; ischemic preconditioning

In ischemic myocardium decreased intracellular ATP level affects metabolic, electrophysiologic and mechanical performance. One of the most critical protective mechanism for severe myocaraial ischemia is conducted through the activity of the KATP channel. This channel opens when the ATP level drops suppressing inward Ca current, and preserves ATP consumption.We ligated rat coronary artery to establish the model for myocardial ischemia under various conditions, and found that there is differential expression among the subunits of KATP channel, Kir6.1, Kir6.2 and SUR. This may be one of the protective mechanism in preparation for recurrent ischemia by more easily opens under higher ATP level.We expressed Kir6.1-Kir6.2 tandem recombinant protein in cultured cells and measured the potassium current to found each chimeric protein had a intermediate channel property between homo-tetramer. We also observed the intracellular distribution and the efficiency of transport of each chymeric channel protein, Kir6.x and SURx, labeled with GFP using confocal microscopy. The variable combination of each isoprotein resulted in remarkable change in the intracellular sorting of the channel protein.These mechanism may work for subtle control of the activity of KATP channel under various degree of ischemia in the myocardial cells. We also determined the expression and electrophysiological character affected with angiotensin receptor blocker or signal transduction components, such as Na-K ATPase or phospholipase C.

在缺血性心肌中，细胞内 ATP 水平降低会影响代谢、电生理和机械性能。严重心肌缺血最关键的保护机制之一是通过 KATP 通道的活性进行的。当ATP水平下降时，该通道打开，抑制内向Ca电流，并保留ATP消耗。我们结扎大鼠冠状动脉建立不同条件下的心肌缺血模型，发现KATP通道亚基Kir6之间存在差异表达。 1、Kir6.2和SUR。这可能是在更高的ATP水平下更容易打开而为复发性缺血做准备的保护机制之一。我们在培养细胞中表达Kir6.1-Kir6.2串联重组蛋白并测量钾电流，发现每个嵌合蛋白都有一个中间体同源四聚体之间的通道特性。我们还使用共聚焦显微镜观察了用 GFP 标记的每种糜聚通道蛋白 Kir6.x 和 SURx 的细胞内分布和运输效率。各同种蛋白的可变组合导致通道蛋白的细胞内排序发生显着变化。这些机制可能在心肌细胞不同程度缺血下对KATP通道的活性进行微妙的控制。我们还确定了血管紧张素受体阻滞剂或信号转导成分（例如 Na-K ATP 酶或磷脂酶 C）影响的表达和电生理特征。

项目成果

Kono Y, Horie M, Takano M, Otani H, Xie LH, Akao M, Tsuji K, Sasayama S.: "The properties of the Kir6.1-6.2 tandem channel co-expressed with SUR2A"Pflugers Arch.. 440(5). 692-8 (2000)

Kono Y，Horie M，Takano M，Otani H，Xie LH，Akao M，Tsuji K，Sasayama S.：“Kir6.1-6.2串联通道与SUR2A共同表达的特性”Pflugers Arch.. 440(5

Yoshida H et al.: "A novel missense mutation in the pore region of HERG in a long QT syndrome patient causes a severe dominant negative effect on HERG function"J Cardiovas Electrophysiol. 10. 1262-1270 (1999)

Yoshida H 等人：“长 QT 综合征患者 HERG 孔区中的一种新型错义突变会对 HERG 功能产生严重的显性负效应”J Cardiovas Electrophysiol。

Ai T, Fujiyama Y, Otani H, et al.: "Novel KCNJ2 mutation in familial periodic paralysis with ventricular dysrhythmia"Circulation. (in press).

Ai T、Fujiyama Y、Otani H 等人：“家族性周期性麻痹伴室性心律失常中的新型 KCNJ2 突变”循环。

Yoshida H, Horie M, Otani H, et al.: "Brady cardia-induced long QT syndrome caused by a de novo missense mutation in the S2-S3 inner loop of HERG"Am J Med Genet. 98(4). 348-352 (2001)

Yoshida H、Horie M、Otani H 等人：“由 HERG S2-S3 内环中的从头错义突变引起的缓慢性心动过速诱发的长 QT 综合征”Am J Med Genet。

Haruna T, Horie M, Takano M, Kono Y, Yoshida H, Otani H, Kubota T, Ninomiya T, Akao M, Sasayama S.: "Alteration of the membrane lipid environment by L-palmitoylcarnitine modulates K(ATP) channels in guinea-pig ventricular myocytes"Pflugers Arch.. 441(2-3)

Haruna T、Horie M、Takano M、Kono Y、Yoshida H、Otani H、Kubota T、Ninomiya T、Akao M、Sasayama S.：“L-棕榈酰肉碱改变膜脂环境可调节几内亚的 K(ATP) 通道