Indole-3-acetic acid/horseradish peroxidase-induced apoptosis involves cell surface CD95 (Fas/APO-1) expression.
Recently, we showed that a combination of indole-3-acetic acid (IAA) and horseradish peroxidase (HRP) produces hydrogen peroxide (H2O2), and that this leads to the apoptosis of G361 human melanoma cells. In the present study, flow cytometric analysis confirmed that H2O2 is involved the IAA/HRP-induced apoptotic process. We also found that IAA/HRP increases cell surface CD95 (Fas/APO-1) expression, and that this is blocked by catalase treatment. Furthermore, blocking CD95 with a neutralizing antibody significantly restored IAA/HRP-induced apoptosis. In addition, the IAA/HRP-induced activations of CD95 downstream molecules, i.e., caspase-8, Bid, and caspase-3, were also inhibited by catalase. Moreover, a caspase-8 inhibitor significantly blocked IAA/HRP-induced apoptosis. These results indicate that IAA/HRP-induced apoptosis involves a CD95-initiated death receptor signaling pathway initiated by hydrogen peroxide.
Kim
Dong-Seok
DS
Research Division for Human Life Sciences, Seoul National University, Korea.
Kim
So-Young
SY
Jeong
Yun-Mi
YM
Jeon
Sang-Eun
SE
Kim
Myo-Kyoung
MK
Kwon
Sun-Bang
SB
Park
Kyoung-Chan
KC
D000906:Antibodies / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002374:Catalase / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D005434:Flow Cytometry; D006735:Horseradish Peroxidase / Q000494:pharmacology*; D006801:Humans; D007210:Indoleacetic Acids / Q000494:pharmacology*; D018613:Microscopy, Confocal; D019014:fas Receptor / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D007210:Indoleacetic Acids; D019014:fas Receptor; C030737:indoleacetic acid; D006735:Horseradish Peroxidase; D002374:Catalase