title: Role of naofen in apoptosis of hepatocytes induced by lipopolysaccharide through mitochondrial signaling in rats.
abstract: OBJECTIVE
  Lipopolysaccharide (LPS) causes apoptosis of hepatocytes, which is probably mediated by inflammatory substances released from Kupffer cells (KCs). Recently, we have reported that naofen, a newly found intracellular WD40-repeat protein, has a role in inducing the apoptosis in HEK293 cells. Hence, the present study was undertaken to investigate a role of naofen in the LPS-induced apoptosis of rat hepatocytes.
  
  
  METHODS
  Rats were treated with i.v. injections of LPS, and livers were extirpated to evaluate expression of naofen and apoptosis. In in vitro experiments, hepatocytes and KCs were separately isolated from rat livers. The incubation medium for KCs treated with LPS (KC-CM) was used for hepatocyte culture.
  
  
  RESULTS
  Intravenous injections of LPS enhanced the expression of naofen in the livers. Livers showed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive staining, and elevated caspase-3 activity. In isolated KCs or hepatocytes, LPS hardly affected naofen expression and caspase-3 activity, whereas incubation of hepatocytes with KC-CM enhanced both naofen expression and caspase-3 activation. Transfection of hepatocyte with naofen siRNA prevented such effects of KC-CM, and clearly eliminated KC-CM-induced reduction of Bcl-2 and Bcl-xL. In contrast, overexpression of naofen in hepatocytes downregulated Bcl-2 and Bcl-xL, released cytochrome c from mitochondria, and activated caspase-3.
  
  
  CONCLUSIONS
  These results indicate that LPS may induce the hepatic apoptosis in association with enhanced naofen expression, and that naofen may mediate the activation of caspase-3 through downregulating the Bcl-2 and Bcl-xL expression, and releasing cytochrome c from mitochondria to cytoplasm.
authors.affiliation: Department of Gastroenterology, Nagoya University Graduate School of Medicine, Nagoya, Departments of              Pharmacology             Anesthesiology, Aichi Medical University School of Medicine, Nagakute             Health Research Center, Aichi Gakuin University, Nisshin, Aichi Prefecture, Japan.
authors.forename: Jun-Hua
authors.initials: JH
authors.lastname: Fan
authors.forename: Guo-Gang
authors.initials: GG
authors.lastname: Feng
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
authors.forename: Koji
authors.initials: K
authors.lastname: Tsunekawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Honda
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Katano
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Kandatsu
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ando
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Koide
authors.forename: Shoshiro
authors.initials: S
authors.lastname: Okada
authors.forename: Naohisa
authors.initials: N
authors.lastname: Ishikawa