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

在本研究中，我们探讨了三磷酸腺苷结合盒蛋白(ABC蛋白)对肝脏的保护作用，以减轻肝脏的缺血再灌注损伤。重点研究了ATP敏感性钾通道(K-ATP通道)的功能，它有助于控制离子流对细胞的保护作用。心肌K-ATP通道的细胞保护机制是人们普遍关注的问题。然而，其在肝脏中的作用尚不清楚。因此，我们对K-ATP通道在肝脏中的表达和功能进行了研究。首先，我们检测了肝脏中K-ATP通道的存在。K-ATP由Kir6.x(6.1或6.2)和Sur(SUR1或SUR2)亚基组成。通过RT-PCR和Northern blotting等方法进行mRNA表达，我们发现Kir6.1/SUR2B复合体作为K-ATP通道亚单位存在于肝脏中。此外，我们将肝脏的组成细胞分离为实质细胞(PC)和非实质细胞(NPC)。鼻咽癌中存在Kir6.1/SUR2B复合体。在c…中在PC中还检测到Kir6.1、6.2、SUR1、2A和2B的mRNAs。Western印迹分析检测到PC中KIR蛋白的表达，而未检测到SUR的表达。再用通道开放剂或阻断剂在缺血再灌流前进行预处理，从mRNA表达的变化来确定K-ATP通道的存在。通道阻滞剂可降低SUR1的mRNA表达。鉴于内皮细胞被认为是肝脏K-ATP通道的位置，我们应用基因转染法去除了细胞因子相关的转录因子，因为内皮细胞在缺血再灌注损伤下会产生各种细胞因子相关的因子。这些因素影响了K-ATP通道对细胞的保护作用。我们发展并证明了裸露寡核苷酸可转染内皮细胞。用这种新的基因转染法明确K-ATP通道在血管内皮细胞中的作用是今后的需要。较少

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