| Project/Area Number |
08457077
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Experimental pathology
|
|---|
| Research Institution | Nihon University |
|---|
Principal Investigator |
ESUMI Mariko Nihon University, School of Medicine Associate Professor, 医学部, 助教授 (30167291)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KATO Tamami Nihon University School of Medicine, Research Associate, 医学部, 助手 (70224516)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Project Status |
Completed (Fiscal Year 1997)
|
| Budget Amount *help |
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 1997: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1996: ¥3,900,000 (Direct Cost: ¥3,900,000)
|
|---|
| Keywords | Hepatitis C virus / Hepatocellular carcinoma / Traansgenic mouse / Methylation / 5-Azacytidine / トランスジェニックスマウス |
|---|
| Research Abstract |
1. Production of transgenic mice
To establish an animal model of hepatitis C and hepatocellular carcinoma, we generated 31 transgenic mice carrying hepatitis C virus (HCV) genome : 3 lines of transgenic mice carrying a partial genome including the structural protein region under the control of the albumin promoter/enhancer (Alb-HN3.8), 19 lines with the whole genome of HCV (Alb-HN2) and 9 lines with the whole genome under the control of the SRalpha promoter (ME-HN2). HCV-specific RNA was little expressed within 8 weeks after birth.
2. Induction of transgene expression
To analyze the mechanism of transgene inactivation, we examined methylation inactivation of the transgene. Methylation-sensitive restriction enzyme fragment analysis and mapping of methylated cytosine by bisulfite-genome sequencing showed that the transgene was extensively methylated. A demethylating agent, 5-azacytidine, induced HCV gene expression in 4 of 6 lines examined. These results suggest that methylation of HCV cDNA is a cause of its suppressive expression in transgenic mice.
3. Histopathological changes of transgenic liver
We investigated long-term pathological changes in liver of transgenic mice. Hepatitis such as semi-acute phase of fulminant hepatitis and liver atrophy with lymphocyte infiltration and ascitic accumulation was observed in mice with 7 to 22 months of age : I of 1 mouse in line Alb-HN3.8-l, 1 of 4 mice in line Alb-HN2-48, and 1 of 6 mice in line ME-HN2-5. The expression of HCV RNA was detected in these liver tissues. As for line Alb-HN2-44, dysplastic changes were observed in 2 of 17 transgenic livers. One of them developed adenoma. These results suggest that only the expression of transgene induces pathological change of liver. However, it is further necessarily examined whether these changes observed are transgene-associated.
|
