title: Gene expression profile in the regenerating rat liver after partial hepatectomy.
abstract: OBJECTIVE
  When a loss of hepatic mass occurs, the expression of a large number of genes is either induced or altered, accompanying hepatocyte proliferation. In the present study, we made an in-house cDNA microarray containing 4608 elements (Liver chip), and analyzed extensively gene expression profiles of the regenerating liver after 70% partial hepatectomy (PHx) in rats.
  
  
  METHODS
  RNAs were prepared from three rat livers at each time point (taken at 0, 6, 12, 18, 24, 48, 72 h, and 1 week after PHx). Using the liver chip, we performed large-scale analysis of gene expression during liver regeneration. Elements either up- or down-regulated more than twofold at one or more time points were selected.
  
  
  RESULTS
  Among the 4608, 382 were identified. Using cluster analysis, we found great similarity between gene-expression profiles at 12 and 18 h after PHx as well as between 48 and 72 h after PHx. We also found that there are at least six distinct temporal patterns of gene expression in the regenerating rat liver after PHx.
  
  
  CONCLUSIONS
  These results indicated that microarray analysis is a powerful approach for monitoring molecular events in the regenerating liver.
authors.affiliation: Department of Innovative Surgery, National Research Institute for Child Health and Development, 3-35-31 Taishido, Setagaya-ku, 154-8567, Tokyo, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Fukuhara
authors.forename: Akira
authors.initials: A
authors.lastname: Hirasawa
authors.forename: Xiao Kang
authors.initials: XK
authors.lastname: Li
authors.forename: Mikiko
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujino
authors.forename: Naoko
authors.initials: N
authors.lastname: Funeshima
authors.forename: Susumu
authors.initials: S
authors.lastname: Katsuma
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shiojima
authors.forename: Masateru
authors.initials: M
authors.lastname: Yamada
authors.forename: Torayuki
authors.initials: T
authors.lastname: Okuyama
authors.forename: Seiichi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Gozoh
authors.initials: G
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D006498:Hepatectomy / Q000379:methods; D008115:Liver Regeneration / Q000235:genetics*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D011184:Postoperative Period; D012313:RNA / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D012313:RNA