Investigation of HDV antigen induced genes and associated proteins in Huh7 cells

• Main Authors: Chu-Cheng, 蔡居政
• Other Authors: Gwo-Tarng Sheu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/89537361497413739896

碩士 === 中山醫學大學 === 醫學分子毒理學研究所 === 95 === The genome of hepatitis delta virus (HDV) is composed of a circular single-stranded RNA molecule of 1.7 kb. The gene of hepatitis delta antigen (HDAg) consists of two related proteins. The small form is a 24 kD (195 amino acids) of S-HDAg, which is essential for replication of HDV RNA genome. The large form is L-HDAg, which is a 27 kD (214 amino acids), that is essential for particle assembly of HDV RNA. We have found that mRNA level of clusterin of Huh7 cells stablely expressing L-HDAg (Lg stable clone) was higher than Huh7 cells not expressing HDAgs. Our first goal was to examine the regulation of clusterin expression by L-HDAg. Therefore, we demonstrated secretary form of clusterin (sCLU) in Lg stable clone and its medium are higher than Huh7 cells stablely expressing S-HDAg (Sm stable clone) and Huh7 cells. Cells with higher sCLU decrease sensitivity to ADR treatment. Because of L-HDAg enhances histone H3 acetylation and induces expression of clusterin protein, it indicates that L-HDAg regulates the activity of HATs or HDACs to induce clusterin expression. We also found that in about 90% (7/8) of patients with hepatitis, the level of sCLU in the serum was higher than normal control group. The second goal was to examine the association hnRNP H1 with S-HDAg. Although we demonstrated hnRNP H1 did not bind to S-HDAg directly, the expression level of clusterin in Lg and Sm stable clone nuclear fractions are higher than Huh7 nuclear fraction. To further screen the HDAgs associated proteins, we prepared Huh7 nuclear fraction and Lg or Sm stable clone nuclear fractions for immunoprecipitation and two-dimensional electrophoresis analysis that may provide a new insight for HDV research.