title: Liver repopulation after cell transplantation in mice treated with retrorsine and carbon tetrachloride.
abstract: BACKGROUND
  Efficiency of engraftment after liver cell transplantation is less than 1% under conventional conditions. Our aim was to develop a high-efficiency, nonsurgical, no-genetic-advantage mouse model of liver repopulation with transplanted cells.
  
  
  METHODS
  Mice were conditioned with nonlethal doses of a cell cycle inhibitor, retrorsine, 70 mg/kg, to irreversibly block proliferation of native hepatocytes. After the drug was eliminated, 2 million freshly isolated beta-galactosidase-labeled liver cells were transplanted into the spleens of C57BL/6J recipient mice. To stimulate donor cell proliferation, three doses of carbon tetrachloride (CCl4), 0.5 ml/kg, were given. Several control groups were studied to evaluate the contribution of each treatment to liver repopulation.
  
  
  RESULTS
  Repopulation, as measured by cell isolation from recipient livers 1-7 months after transplantation, was on average 20%. Repopulation was 10% if CCl4 was given only once, between 0.5% and 1% if only retrorsine or CCl4 were used, and 0.05% if no conditioning was used. Phenotypically, whole livers turned blue on exposure to X-gal staining, whereas negative (control) livers remained pale brown. More than 55% of liver repopulation resulted from clusters containing 21 or more cells, some of which contained more than 200 cells, suggesting seven or more rounds of cell division in a subset of transplanted cells.
  
  
  CONCLUSIONS
  This murine study demonstrates high levels of repopulation after liver cell transplantation into nongenetically modified livers, using a cell cycle inhibitor and chemical liver injury to provide transplanted cells a proliferative advantage. Liver repopulation was effected mostly by a small fraction of transplanted cells. Analogous nonsurgical liver cell transplantation strategies, but with clinically applicable drugs, could be devised for the treatment of liver-based metabolic diseases.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics and Surgery, Northwestern University Medical School, Chicago, IL 60614, U.S.A.
authors.forename: Danqing
authors.initials: D
authors.lastname: Guo
authors.forename: Tao
authors.initials: T
authors.lastname: Fu
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Nelson
authors.forename: Riccardo A
authors.initials: RA
authors.lastname: Superina
authors.forename: Humberto E
authors.initials: HE
authors.lastname: Soriano
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002251:Carbon Tetrachloride / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D005260:Female; D005697:Galactosides; D022781:Hepatocytes / Q000166:cytology* / Q000637:transplantation*; D007211:Indoles; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D023421:Models, Animal; D010641:Phenotype; D011763:Pyrrolizidine Alkaloids / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology; D019172:Transplantation Conditioning
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005697:Galactosides; D007211:Indoles; D011763:Pyrrolizidine Alkaloids; D002251:Carbon Tetrachloride; C044888:5-bromo-4-chloro-3-indolyl beta-galactoside; C003300:retrorsine