Control of ceramide-induced apoptosis by IGF-1: involvement of PI-3 kinase, caspase-3 and catalase.
Insulin-like growth factor-1 (IGF-1) inhibited N-acetylsphingosine (C2-ceramide)-induced HL-60 cell apoptosis via relieving oxidative damage. This inhibitory action of IGF-1 was blocked by a phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin and enhanced by overexpression of the p110 catalytic subunit of PI-3 kinase. Either IGF-1 pretreatment or PI-3 kinase overexpression restored ceramide-depleted catalase function, and this restoration was inhibited by wortmannin. A catalase inhibitor 3-amino-1h-1, 2, 4-triazole (ATZ) blocked the inhibitory action of IGF-1 on ceramide-induced apoptosis, whereas exogenous purified catalase enhanced it. Ceramide-activated caspase-3 was inhibited by IGF-1/PI-3 kinase and enhanced by wortmannin, while the addition of a specific caspase-3 inhibitor DMQD-CHO significantly enhanced the restoration by IGF-1 of ceramide-depleted catalase function. Moreover, IGF-1 inhibited C2-ceramide-induced decrease of mitochondrial membrane potential, and increase of cytochrome c release, caspase-3 cleavage and caspase-3 activity as judged by PhiPhiLux cleaving method. In summary, these results suggest that IGF-1/PI-3 kinase inhibited C2-ceramide-induced apoptosis due to relieving oxidative damage, which resulted from the inhibition of catalase by activated caspase-3.
Kondo
T
T
Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, 54 Syogoin-Kawaramachi, Sakyo-ku, Kyoto 606-8507, Japan.
Kitano
T
T
Iwai
K
K
Watanabe
M
M
Taguchi
Y
Y
Yabu
T
T
Umehara
H
H
Domae
N
N
Uchiyama
T
T
Okazaki
T
T
D000730:Androstadienes / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002374:Catalase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D007425:Intracellular Membranes / Q000502:physiology; D050356:Lipid Metabolism; D015227:Lipid Peroxidation; D008564:Membrane Potentials; D008928:Mitochondria / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D010084:Oxidation-Reduction; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000502:physiology*; D000077191:Wortmannin
D000730:Androstadienes; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; C064769:N-acetylsphingosine; D009842:Oligopeptides; C110922:acetyl-aspartyl-methionyl-glutaminyl-aspartyl-aldehyde; D007334:Insulin-Like Growth Factor I; D002374:Catalase; D019869:Phosphatidylinositol 3-Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D013110:Sphingosine; D000077191:Wortmannin