title: Generation of Novel Chimeric Mice with Humanized Livers by Using Hemizygous cDNA-uPA/SCID Mice.
abstract: We have used homozygous albumin enhancer/promoter-driven urokinase-type plasminogen activator/severe combined immunodeficient (uPA/SCID) mice as hosts for chimeric mice with humanized livers. However, uPA/SCID mice show four disadvantages: the human hepatocytes (h-heps) replacement index in mouse liver is decreased due to deletion of uPA transgene by homologous recombination, kidney disorders are likely to develop, body size is small, and hemizygotes cannot be used as hosts as more frequent homologous recombination than homozygotes. To solve these disadvantages, we have established a novel host strain that has a transgene containing albumin promoter/enhancer and urokinase-type plasminogen activator cDNA and has a SCID background (cDNA-uPA/SCID). We applied the embryonic stem cell technique to simultaneously generate a number of transgenic lines, and found the line with the most appropriate levels of uPA expression-not detrimental but with a sufficiently damaged liver. We transplanted h-heps into homozygous and hemizygous cDNA-uPA/SCID mice via the spleen, and monitored their human albumin (h-alb) levels and body weight. Blood h-alb levels and body weight gradually increased in the hemizygous cDNA-uPA/SCID mice and were maintained until they were approximately 30 weeks old. By contrast, blood h-alb levels and body weight in uPA/SCID chimeric mice decreased from 16 weeks of age onwards. A similar decrease in body weight was observed in the homozygous cDNA-uPA/SCID genotype, but h-alb levels were maintained until they were approximately 30 weeks old. Microarray analyses revealed identical h-heps gene expression profiles in homozygous and hemizygous cDNA-uPA/SCID mice were identical to that observed in the uPA/SCID mice. Furthermore, like uPA/SCID chimeric mice, homozygous and hemizygous cDNA-uPA/SCID chimeric mice were successfully infected with hepatitis B virus and C virus. These results indicate that hemizygous cDNA-uPA/SCID mice may be novel and useful hosts for producing chimeric mice for use in future long-term studies, including hepatitis virus infection analysis or drug toxicity studies.
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.|Liver Research Project Center, Hiroshima University, Hiroshima, Japan.
authors.forename: Chise
authors.initials: C
authors.lastname: Tateno
authors.affiliation: Chugai Research Institute for Medical Science, Inc., Gotemba, Shizuoka, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kawase
authors.affiliation: Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Tobita
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Hamamura
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohshita
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokomichi
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Harumi
authors.initials: H
authors.lastname: Sanada
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kakuni
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shiota
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.
authors.forename: Yuha
authors.initials: Y
authors.lastname: Kojima
authors.affiliation: PhoenixBio Co., Ltd., Higashihiroshima, Hiroshima, Japan.|Liver Research Project Center, Hiroshima University, Hiroshima, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shitara
authors.affiliation: Chugai Research Institute for Medical Science, Inc., Gotemba, Shizuoka, Japan.
authors.forename: Naoko A
authors.initials: NA
authors.lastname: Wada
authors.affiliation: Chugai Research Institute for Medical Science, Inc., Gotemba, Shizuoka, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Tateishi
authors.affiliation: Chugai Pharmaceutical Co., Ltd., Gotemba, Shizuoka, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sudoh
authors.affiliation: Sekisui Medical Co., Ltd., Tokyo, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nagatsuka
authors.affiliation: Chugai Pharmaceutical Co., Ltd., Gotemba, Shizuoka, Japan.
authors.forename: Kou-Ichi
authors.initials: K
authors.lastname: Jishage
authors.affiliation: Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Michinori
authors.initials: M
authors.lastname: Kohara
mesh_terms: D000818:Animals; D001947:Breeding; D002648:Child; D002675:Child, Preschool; D046528:Chimerism; D004195:Disease Models, Animal; D005260:Female; D057898:Hemizygote; D006518:Hepatitis Viruses / Q000472:pathogenicity; D006525:Hepatitis, Viral, Human; D022781:Hepatocytes / Q000637:transplantation; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008815:Mice, Inbred Strains / Q000235:genetics* / Q000821:virology; D016513:Mice, SCID