title: Poly(ADP-ribose) polymerase-1 signaling to mitochondria in necrotic cell death requires RIP1/TRAF2-mediated JNK1 activation.
abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) hyperactivation-induced necrosis has been implicated in several pathophysiological conditions. Although mitochondrial dysfunction and apoptosis-inducing factor translocation from the mitochondria to the nucleus have been suggested to play very important roles in PARP-1-mediated cell death, the signaling events downstream of PARP-1 activation in initiating mitochondria dysfunction are not clear. Here we used the DNA alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine, a potent PARP-1 activator, to study PARP-1 activation-mediated cell death. We found, based on genetic knockouts and pharmacological inhibition, that c-Jun N-terminal kinase (JNK), especially JNK1, but not the other groups of mitogen-activated protein kinase, is required for PARP-1-induced mitochondrial dysfunction, apoptosis-inducing factor translocation, and subsequent cell death. We reveal that receptor-interacting protein 1 (RIP1) and tumor necrosis factor receptor-associated factor 2 (TRAF2), are upstream of JNK in PARP-1 hyperactivated cells, because PARP-1-induced JNK activation was attenuated in RIP1-/- and TRAF2-/- mouse embryonic fibroblast cells. Consistently, knockouts of RIP1 and TRAF2 caused a resistance to PARP-1-induced cell death. Therefore, our study uncovers that RIP1, TRAF2, and JNK comprise a pathway to mediate the signaling from PARP-1 overactivation to mitochondrial dysfunction.
authors.affiliation: Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.forename: Shuang
authors.initials: S
authors.lastname: Huang
authors.forename: Zheng-Gang
authors.initials: ZG
authors.lastname: Liu
authors.forename: Jiahuai
authors.initials: J
authors.lastname: Han
mesh_terms: D000818:Animals; D016923:Cell Death; D002461:Cell Line, Transformed; D004789:Enzyme Activation; D005347:Fibroblasts / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008928:Mitochondria / Q000378:metabolism; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism*; D009336:Necrosis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D015398:Signal Transduction; D047992:TNF Receptor-Associated Factor 2 / Q000235:genetics / Q000378:metabolism*
chemical_list: D020690:GTPase-Activating Proteins; C490620:Ralbp1 protein, mouse; D047992:TNF Receptor-Associated Factor 2; D011065:Poly(ADP-ribose) Polymerases; D048055:Mitogen-Activated Protein Kinase 8