title: Ethanol-induced apoptosis in human liver adenocarcinoma cells (SK-Hep1): Fas- and mitochondria-mediated pathways and interaction with MAPK signaling system.
abstract: For studying molecular mechanisms regulating the fate of ethanol-treated hepatocytes, involvement of Fas in ethanol-induced apoptosis was examined in human liver adenocarcinoma (SK-Hep1) cells in which the function of Fas-associated death domain (FADD) protein was knocked down by transfection. In FADD-knocked down cells, while ethanol-induced increase in generation of reactive oxygen species (ROS) was unaffected, apoptosis was significantly suppressed, demonstrating the involvement of Fas in ethanol-induced hepatocyte apoptosis more directly than in the past reports. On the other hand, effects of mitogen-activated protein kinase (MAPK), which is well known to determine the fate of various cells, on ethanol-induced apoptosis have not been examined in SK-Hep1 cells. Of three major MAPKs, only p38 MAPK and JNK were found activated by 200 mM ethanol treatment. When cells were incubated with inhibitors of p38 MAPK and JNK, ethanol-induced apoptosis was decreased while ROS generation was unaffected, and examination of pro-apoptotic Bax and anti-apoptotic Bcl-2 levels showed decrease of the former and increase of the latter. We concluded that oxidative stress inflicted by ROS triggered Fas-mediated and mitochondria-mediated apoptotic pathways in ethanol-treated SK-Hep1 cells, and that p38 MAPK and JNK were promoting mitochondrial pathway, suggesting interaction between apoptosis and MAPK signaling systems.
authors.affiliation: Department of Pharmacology, School of Medicine, Showa University, Hatanodai 1-5-8, Shinagawa-ku, Tokyo 142-8555, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Morio
authors.forename: Mayumi
authors.initials: M
authors.lastname: Tsuji
authors.forename: Manami
authors.initials: M
authors.lastname: Inagaki
authors.forename: Mai
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Yuri
authors.initials: Y
authors.lastname: Asaka
authors.forename: Hideto
authors.initials: H
authors.lastname: Oyamada
authors.forename: Kanji
authors.initials: K
authors.lastname: Furuya
authors.forename: Katsuji
authors.initials: K
authors.lastname: Oguchi
mesh_terms: D000230:Adenocarcinoma; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor; D000431:Ethanol / Q000633:toxicity*; D053200:Fas-Associated Death Domain Protein / Q000502:physiology*; D006801:Humans; D008113:Liver Neoplasms; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D051028:bcl-2-Associated X Protein; D000431:Ethanol; D020928:Mitogen-Activated Protein Kinases; C505530:CASP8 protein, human; D053148:Caspase 3; D053181:Caspase 8
keywords: Alcoholic liver injury; Ethanol-induced apoptosis; Fas; MAPK; ROS; SK-Hep1 cells