UV-induced apoptosis in SH-SY5Y cells: contribution to apoptosis by JNK signaling and cytochrome c.
Activation of the c-Jun N-terminal kinase (JNK) pathway is suggested to be required for neuronal apoptosis. We investigated the role of JNK on phosphorylation of c-Jun, Bcl-2, and apoptotic translocation of cytochrome c (cyt c) in UV-induced apoptosis in human neuroblastoma SH-SY5Y cells. We confirm that UV irradiation induces both apoptosis and necrosis in SH-SY5Y cells and that phosphorylation of JNK at Thr183/Tyr185 in SH-SY5Y cells treated with UV is an early event preceding apoptosis. We also demonstrate that phosphorylation of c-Jun at Ser63 is an early event coinciding with JNK activation, and that the phosphorylation of c-Jun is partially prevented by the JNK inhibitor SP600125. Despite the use of SP600125, the amount of cyt c released into the cytoplasm is not diminished and SP600125 is also unable to decrease the extent of UV-induced apoptosis. These data support the hypothesis that in this system, UV-induced apoptosis is not dependent exclusively on JNK activation. Possible involvement of cyclin-dependent kinases (CDKs) in c-Jun phosphorylation at Ser63 was excluded by pretreating UV-irradiated SH-SY5Y cells with the CDK1/2/5 inhibitor roscovitine.
Berglund
C Mikaela D
CM
Department of Medicine and Center of Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
Radesäter
Ann-Cathrin
AC
Persson
Mats A A
MA
Budd Haeberlein
Samantha L
SL
D000873:Anthracenes / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology / Q000528:radiation effects*; D015153:Blotting, Western / Q000379:methods; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D045304:Cytochromes c / Q000378:metabolism*; D004347:Drug Interactions; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism / Q000528:radiation effects; D009447:Neuroblastoma / Q000473:pathology; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000873:Anthracenes; D004791:Enzyme Inhibitors; D016755:Proto-Oncogene Proteins c-jun; C432165:pyrazolanthrone; D045304:Cytochromes c; D007770:L-Lactate Dehydrogenase; D048031:JNK Mitogen-Activated Protein Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases