title: Significance and therapeutic potential of endothelial progenitor cell transplantation in a cirrhotic liver rat model.
abstract: OBJECTIVE
  We investigated whether endothelial progenitor cell (EPC) transplantation could reduce established liver fibrosis and promote hepatic regeneration by isolating rat EPCs from bone marrow cells.
  
  
  METHODS
  Recipient rats were injected intraperitoneally with carbon tetrachloride (CCl(4)) twice weekly for 6 weeks before initial administration of EPCs. CCl(4) was then readministered twice weekly for 4 more weeks, and EPC transplantation was carried out for these same 4 weeks.
  
  
  RESULTS
  At 7 days in culture, the cells expressed Thy-1, CD31, CD133, Flt-1, Flk-1, and Tie-2, suggesting an immature endothelial lineage. Immunohistochemical analyses showed fluorescent-labeled, transplantation EPCs were incorporated into the portal tracts and fibrous septa. Single and multiple EPC transplantation rats had reduced liver fibrosis, with decreased alpha2-(I)-procollagen, fibronectin, transforming growth factor-beta, and alpha-smooth muscle actin-positive cells. Film in situ zymographic analysis revealed strong gelatinolytic activity in the periportal area, in accordance with EPC location. Real-time polymerase chain reaction analysis of multiple EPC-transplantation livers showed significantly increased messenger RNA levels of matrix metalloproteinase (MMP)-2, -9 and -13, whereas tissue inhibitor of metalloproteinase-1 expression was significantly reduced. Expression of hepatocyte growth factor, transforming growth factor-alpha, epidermal growth factor, and vascular endothelial growth factor was increased in multiple EPC-transplantation livers, while hepatocyte proliferation increased. Transaminase, total bilirubin, total protein, and albumin levels were maintained in EPC-transplantation rats, significantly improving survival rates.
  
  
  CONCLUSIONS
  We conclude that single or repeated EPC transplantation halts established liver fibrosis in rats by suppressing activated hepatic stellate cells, increasing matrix metalloproteinase activity, and regulating hepatocyte proliferation.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Fukuoka, Japan. ntoru@med.kurume-u.ac.jp <ntoru@med.kurume-u.ac.jp>
authors.forename: Toru
authors.initials: T
authors.lastname: Nakamura
authors.forename: Takuji
authors.initials: T
authors.lastname: Torimura
authors.forename: Masaharu
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Hashimoto
authors.forename: Eitaro
authors.initials: E
authors.lastname: Taniguchi
authors.forename: Kinya
authors.initials: K
authors.lastname: Inoue
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Sakata
authors.forename: Ryukichi
authors.initials: R
authors.lastname: Kumashiro
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
authors.forename: Takato
authors.initials: T
authors.lastname: Ueno
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002251:Carbon Tetrachloride; D002455:Cell Division; D002478:Cells, Cultured; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000166:cytology; D006085:Graft Survival; D022781:Hepatocytes / Q000166:cytology / Q000201:enzymology; D017404:In Situ Hybridization, Fluorescence; D008103:Liver Cirrhosis / Q000139:chemically induced / Q000473:pathology / Q000628:therapy*; D008115:Liver Regeneration; D008297:Male; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D033581:Stem Cell Transplantation / Q000379:methods*; D013853:Thioacetamide; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D013853:Thioacetamide; D002251:Carbon Tetrachloride; D020782:Matrix Metalloproteinases