JNK2 translocates to the mitochondria and mediates cytochrome c release in PC12 cells in response to 6-hydroxydopamine.
6-Hydroxydopamine (6-OHDA) causes death of dopaminergic neurons by mitochondrial dysfunction with JNKs as central mediators. Here we provide novel insights into specific actions of JNK isoforms in 6-OHDA-induced death of PC12 cells. Twenty five mum 6-OHDA enhanced total JNK activity in the cytoplasm, nucleus, and at the mitochondria. Inhibition of JNKs by 2 mum SP600125 or transfection with dominant-negative JNK2 (dnJNK2) rescued more than 60% of the otherwise dying PC12 cells after 24 h, whereas transfection with dnJNK1 had no protective effects. In contrast to constitutively present JNK1, JNK2 amounts increased in the nucleus and at the mitochondria after 6-OHDA stimulation. JNK inhibition by SP600125 or transfection of dnJNK2 reduced the pool of active JNKs in the nucleus, the release of cytochrome c, as well as the cleavage of caspase-3 and its substrate poly(ADP-ribose) polymerase-1. Transfection with dnJNK1, however, had no effects on the translocation of JNKs to the mitochondria or the release of cytochrome c. Our data provide novel functional insights into the pathological role of individual JNK isoforms, the signalosome at the mitochondria, and the mode of JNK-induced release of cytochrome c.
Eminel
Sevgi
S
Institute of Pharmacology, Schleswig-Holstein University Medical Center, Campus Kiel, Hospitalstrasse 4, 24105 Kiel, Germany.
Klettner
Alexa
A
Roemer
Lutz
L
Herdegen
Thomas
T
Waetzig
Vicki
V
D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D005799:Genes, Dominant; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048670:MAP Kinase Kinase 4; D008928:Mitochondria / Q000378:metabolism*; D048056:Mitogen-Activated Protein Kinase 9 / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D016627:Oxidopamine / Q000737:chemistry* / Q000494:pharmacology; D016716:PC12 Cells; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D020033:Protein Isoforms; D021381:Protein Transport; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D014343:Trypan Blue / Q000494:pharmacology
D000873:Anthracenes; D018076:DNA, Complementary; D020033:Protein Isoforms; C432165:pyrazolanthrone; D016627:Oxidopamine; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D048056:Mitogen-Activated Protein Kinase 9; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D014343:Trypan Blue