Role of ABC protein in hepatic protection and application to hepatic surgery.

在本课题中，我们研究了atp结合盒蛋白（ABC蛋白）在肝脏保护中的作用，以减少肝脏缺血再灌注损伤。我们特别关注了atp敏感钾通道（K-ATP通道）的功能，它通过控制离子流动来保护细胞。心肌K-ATP通道的细胞保护机制已得到普遍关注。然而，它在肝脏中的作用尚不清楚。因此，我们研究了K-ATP通道在肝脏中的表达和功能。首先，我们检查了K-ATP通道在肝脏中的存在。K-ATP由Kir6组成。x（6.1或6.2）和SUR （SUR1或SUR2）亚基。通过RT-PCR和Northern blotting方法分析mRNA表达，我们发现肝脏中存在Kir6.1/SUR2B复合物作为K-ATP通道亚基。此外，我们将肝脏组成细胞分为实质细胞（PCs）和非实质细胞（NPCs）。npc中存在Kir6.1/SUR2B复合体。在pc中检测到Kir6.1、6.2、SUR1、2A和2B的mrna。Western blot检测pc中Kir蛋白的表达，而SUR未检测到表达。在缺血再灌注前，通过通道开通剂或阻滞剂预处理mRNA表达的变化，证实了K-ATP通道的存在。通道阻断剂降低SUR1 mRNA表达。因此，在肝脏中证实了SUR1细胞的存在。由于内皮细胞被认为是肝脏K-ATP通道的所在地，我们采用基因转染消除细胞因子相关转录因子，因为内皮细胞在缺血-再灌注损伤下产生多种细胞因子相关因子。这些因素改变了K-ATP通道细胞保护的结果。我们开发并证明裸寡核苷酸转染内皮细胞。利用这种新的基因转染方法来明确K-ATP通道在内皮细胞中的作用是必要的。少

In this research project, we investigated the role of ATP-binding cassette protein (ABC protein) for hepatic protection to reduce the ischemia-reperfusion injury of the liver. Especially we focused on the function of ATP-sensitive potassium channel (K-ATP channel), which contributes for cell protection by controlled ionic flow. The cell protective mechanism by K-ATP channel of the myocardium is noted universally. However, its contribution in the liver is not clear. Therefore, expression and function of K-ATP channel in the liver was studied.First, we examined the existence of K-ATP channel in the liver. K-ATP is composed of Kir6.x (6.1 or 6.2) and SUR (SUR1 or SUR2) subunits. From mRNA expression using RT-PCR and Northern blotting methods, we found the existence of Kir6.1/SUR2B complex as a K-ATP channel subunit in the liver. Furthermore, we separated the composed cells of the liver to parenchymal cells (PCs) and non-parenchymal cells (NPCs). Kir6.1/SUR2B complex exsisted in NPCs. In c … More ontrast, mRNAs of Kir6.1, 6.2, SUR1, 2A and 2B were detected in PCs. Protein expression of Kir was detected in PCs using Western blot analysis, while SUR expression was not detected. Then we confirmed the existence of K-ATP channel from changes of mRNA expression by preconditioning using channel opener or blocker before ischemia-reperfusion. Channel blocker decreased mRNA expression of SUR1. Accordingly, the existence of cells having SUR1 was proved in the liver.Since endothelial cells are expected to be the location of K-ATP channel in the liver, we applied gene transfection eliminating the cytokine related transcriptional factors, because endothelial cells product various cytokine related factors under the ischemia-reperfusion injury. These factors modify the results of cytoprotection by K-ATP channel. We developed and proved that naked oligonucleotide was transfected to endothelial cells. To clear the role of K-ATP channel in endothelial cells using this new gene transfection method is necessary from now. Less