Short-term and long-term effects of fatty acids in rat hepatoma AS-30D cells: the way to apoptosis.
Arachidonic acid and, to a smaller extent, oleic acid at micromolar concentrations decreased the mitochondrial membrane potential within AS-30D rat hepatoma cells cultivated in vitro and increased cell respiration. The uncoupling effect of both fatty acids on cell respiration was partly prevented by cyclosporin A, blocker of the mitochondrial permeability transition pore. Arachidonic acid increased the rate of reactive oxygen species (ROS) production, while oleic acid decreased it. Both fatty acids induced apoptotic cell death of AS-30D cells, accompanied by the release of cytochrome c from mitochondria to the cytosol, activation of caspase-3 and association of proapoptotic Bax protein with mitochondria; arachidonic acid being a more potent inducer than oleic acid. Trolox, a potent antioxidant, prevented ROS increase induced by arachidonic acid and protected the cells against apoptosis produced by this fatty acid. It is concluded that arachidonic and oleic acids induce apoptosis of AS-30D hepatoma cells by the mitochondrial pathway but differ in the mechanism of their action: Arachidonic acid induces apoptosis mainly by stimulating ROS production, whereas oleic acid may contribute to programmed cell death by activation of the mitochondrial permeability transition pore.
Dymkowska
Dorota
D
Nencki Institute of Experimental Biology, Pasteura 3, 02-093 Warsaw, Poland.
Szczepanowska
Joanna
J
Wieckowski
Mariusz R
MR
Wojtczak
Lech
L
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D016718:Arachidonic Acid / Q000494:pharmacology; D002118:Calcium / Q000032:analysis; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D019069:Cell Respiration / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005227:Fatty Acids / Q000494:pharmacology*; D005434:Flow Cytometry; D007700:Kinetics; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology; D019301:Oleic Acid / Q000494:pharmacology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D014466:Ultraviolet Rays; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D016718:Arachidonic Acid; D019301:Oleic Acid; D016572:Cyclosporine; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D002118:Calcium