Interferon-beta-induced activation of c-Jun NH2-terminal kinase mediates apoptosis through up-regulation of CD95 in CH31 B lymphoma cells.
Type I interferon (IFN)-induced antitumor action is due in part to apoptosis, but the molecular mechanisms underlying IFN-induced apoptosis remain largely unresolved. In the present study, we demonstrate that IFN-beta induced apoptosis and the loss of mitochondrial membrane potential (delta psi m) in the murine CH31 B lymphoma cell line, and this was accompanied by the up-regulation of CD95, but not CD95-ligand (CD95-L), tumor necrosis factor (TNF), or TNF-related apoptosis-inducing ligand (TRAIL). Pretreatment with anti-CD95-L mAb partially prevented the IFN-beta-induced loss of delta psi m, suggesting that the interaction of IFN-beta-up-regulated CD95 with CD95-L plays a crucial role in the induction of fratricide. IFN-beta induced a sustained activation of c-Jun NH2-terminal kinase 1 (JNK1), but not extracellular signal-regulated kinases (ERKs). The IFN-beta-induced apoptosis and loss of delta psi m were substantially compromised in cells overexpressing a dominant-negative form of JNK1 (dnJNK1), and it was slightly enhanced in cells carrying a constitutively active JNK construct, MKK7-JNK1 fusion protein. The IFN-beta-induced up-regulation of CD95 together with caspase-8 activation was also abrogated in the dnJNK1 cells while it was further enhanced in the MKK7-JNK1 cells. The levels of cellular FLIP (c-FLIP), competitively interacting with caspase-8, were down-regulated by stimulation with IFN-beta but were reversed by the proteasome inhibitor lactacystin. Collectively, the IFN-beta-induced sustained activation of JNK mediates apoptosis, at least in part, through up-regulation of CD95 protein in combination with down-regulation of c-FLIP protein.
Takada
Eiko
E
Department of Immunology and Intractable Disease Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, 160-8402, Tokyo, Japan.
Shimo
Kuniaki
K
Hata
Kikumi
K
Abiake
Maira
M
Mukai
Yasuo
Y
Moriyama
Masami
M
Heasley
Lynn
L
Mizuguchi
Junichiro
J
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D016207:Cytokines / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D053222:Fas Ligand Protein; D006801:Humans; D016899:Interferon-beta / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D019169:Jurkat Cells; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D019014:fas Receptor / Q000378:metabolism*
D000970:Antineoplastic Agents; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; C506387:Cflar protein, mouse; D016207:Cytokines; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D019014:fas Receptor; D016899:Interferon-beta; D048031:JNK Mitogen-Activated Protein Kinases