Molecularbiological study for the role of sinusoidal cells in pathogenesis of liver disease.

本研究旨在探讨窦状细胞，特别是库普弗细胞在各种实验性肝损伤中的作用。分析Kupffer细胞氧化应激和一氧化氮释放与肝细胞损伤和凋亡的关系。研究了肝癌细胞与离体大鼠Kupffer细胞共培养后的代谢变化。来自库普弗细胞的一氧化氮诱导肿瘤细胞线粒体功能障碍，并引起肝窦膜屏障功能障碍。在与肝癌细胞共培养的Kupffer细胞中，iNOS和iNOS mRNA的表达增加。研究还表明，cd18 /ICAM-1依赖性细胞与肝癌细胞之间的相互作用导致钙动员和NF-kB的氧化活化，这可能导致Kupffer细胞中NO的产生增加。脂多糖刺激的Kupffer细胞也释放NO和TNF-a，导致肝细胞线粒体损伤。酒精性肝灌注损伤实验模型表明，乙醇可使库普弗细胞释放超氧阴离子进入窦状动脉，导致窦状动脉内皮细胞损伤。Kupffer细胞通过细胞色素P450 2E1代谢乙醇。慢性乙醇饲喂后，LPS可引起微循环紊乱，但剂量较小。白细胞黏附分子的表达，以及白细胞在鼻窦内的黏附。

Aim of this study is to investigate the role of sinusoidal cells, especially Kupffer cells, on various experimental liver injuries. Oxidative stress and release of nitric oxide by Kupffer cells analyzed in relation to hepatocyte injury and apoptosis.The metabolic changes in hepatoma cells co-cultured with isolated rat Kupffer cells were investigated. NO from Kupffer cells induced mitochondrial dysfunction in tumor cells followed by membrane barrier dysfunction in the liver sinusoid. Increased expression of iNOS and iNOS mRNA in the Kupffer cells co-cultured with hepatoma cells was shown. It is also suggested that CD 18/ICAM-1 dependent cell-to-cell interaction with hepatoma cells causes calcium mobilization and oxidative activation of NF-kB , which may lead to the increase production of NO in Kupffer cells. Kupffer cells stimulated by lipopolysaccharides was also shown to release NO and TNF-a, which resulted in mitochondrial injury in hepatocyte.Experimental model of alcoholic liver damage in perfused liver showed that superoxide anion was released from Kupffer cells into sinusoid by ethanol administration, and lead to damage in sinusoidal endothelial cells. Kupffer cells were shown to metabolize ethanol by cytochrome P450 2E1. After chronic ethanol feeding, LPS elicited microcirculatory disturbance with smaller dose. Expression of adhesion molecules on leukocytes, and adhesion of leukocytes in sinusoid was shown.