ASK1-p38 MAPK/JNK signaling cascade mediates anandamide-induced PC12 cell death.
Anandamide is a neuroimmunoregulatory molecule that triggers apoptosis in a number of cell types including PC12 cells. Here, we investigated the molecular mechanisms underlying anandamide-induced cell death in PC12 cells. Anandamide treatment resulted in the activation of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and p44/42 MAPK in apoptosing cells. A selective p38 MAPK inhibitor, SB203580, or dn-JNK, JNK1(A-F) or SAPKbeta(K-R), blocked anandamide-induced cell death, whereas a specific inhibitor of MEK-1/2, U0126, had no effect, indicating that activation of p38 MAPK and JNK is critical in anandamide-induced cell death. An important role for apoptosis signal-regulating kinase 1 (ASK1) in this event was also demonstrated by the inhibition of p38 MAPK/JNK activation and death in cells overexpressing dn-ASK1, ASK1 (K709M). Conversely, the constitutively active ASK1, ASK1DeltaN, caused prolonged p38 MAPK/JNK activation and increased cell death. These indicate that ASK1 mediates anandamide-induced cell death via p38 MAPK and JNK activation. Here, we also found that activation of p38 MAPK/JNK is accompanied by cytochrome c release from the mitochondria and caspase activation (which can be inhibited by SB203580), suggesting that anandamide triggers a mitochondrial dependent apoptotic pathway. The caspase inhibitor, zVAD, and the mitochondrial pore opening inhibitor, cyclosporine A, blocked anandamide-induced cell death but not p38 MAPK/JNK activation, suggesting that activation of these kinases may occur upstream of mitochondrial associated events.
Sarker
Krishna Pada
KP
Department of Laboratory and Molecular Medicine, Faculty of Medicine, Kagoshima University, Kagoshima, Japan.
Biswas
Kamal Krishna
KK
Yamakuchi
Munekazu
M
Lee
Ki-Young
KY
Hahiguchi
Teruto
T
Kracht
Michael
M
Kitajima
Isao
I
Maruyama
Ikuro
I
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001095:Arachidonic Acids / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D063388:Endocannabinoids; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016716:PC12 Cells; D010673:Pheochromocytoma / Q000188:drug therapy* / Q000378:metabolism; D053284:Polyunsaturated Alkamides; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D051381:Rats; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases
D001095:Arachidonic Acids; D063388:Endocannabinoids; D004791:Enzyme Inhibitors; D053284:Polyunsaturated Alkamides; D019253:Proto-Oncogene Proteins c-bcl-2; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases; C078814:anandamide