标题: Analysis of HCV replication and trace element [打印本页] 作者: 我容易吗我 时间: 2015-8-17 12:15 标题: Analysis of HCV replication and trace element nalysis of HCV replication and trace element
metabolism in replicon system by microPIXIE.
Associate Professor
Hitoshi Takagi htakagi@med.gunma-u.ac.jp
Liver disease is called as “National Disease of Japan” in 21st century. Fifty thousands of people died of liver cirrhosis or liver cancer in Japan in these days. Hepatitis C virus (HCV) is the most prevalent cause of these disease. Interferon is widely administered to the patients with HCV but the rate of HCV eradication is around 40-50%, so the more effective treatment is required for those patients.
On the other hand, patients with chronic liver disease tend to be complicated with metabolic disturbance of trace element, namely the decrease of zinc and the increase of iron and copper. The ion channel or transporter of the metals could be related for these changes and substantial amount of data have been accumulated about this. We have reported zinc supplementation additively enhanced the effect of IFN on the eradication of HCV(J Viral Hepatitis,8: 367, 2001). The mechanism of the collaborative effects of zinc on IFN has not yet clarified. Zinc is not only the component of nonstructural protein NS3 but also an inducer of metallothionein, which is an anti-oxidant and a chelating agent of metals. As for iron, phlebotomy could improve the liver function due to iron depletion. Copper increases and deposited to the hepatocytes as liver disease progresses not only in Wilson’s disease and chronic viral hepatitis. These changes are opposite to zinc.
In vitro assay of HCV has not been established because no cell culture system can replicate HCV. Bartenschlager developed in vitro HCV-replication system called “replicon” which can not produce the complete virion of HCV but efficiently express part of structural and nonstructural proteins of HCV in Huh7 hepatoma cell line. This system is useful for pharmacologic assessment of drug effect on HCV. In this system IFN can clearly suppress HCV replicon in physiological concentration.
Our aim in this COE program is the clarification of the relationship between trace element and HCV replication in replicon system using microPIXIE system. Electron microscopic examination could reveal a part of the dynamics of trace element but the quantitative analysis is available only by using microPIXIE system in one cell. MicroPixie can distinguish the change of trace element in nucleus and cytoplasm. Replicon is not ubiquitously expressed in Huh7 so first of all we have to discriminate positive cells and negative cells and compare the difference of trace element. We hope this project will be able to clarify the dynamics of trace element in HCV replicon system and develop the effective treatment for the chronic hepatitis C.