Oxidative stress initiates DNA damager MNNG-induced poly(ADP-ribose)polymerase-1-dependent parthanatos cell death.
The alkylating agent N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG) can cause excess DNA strand breaks that lead to poly(ADP-ribose)polymerase-1 (PARP-1) overactivation and cell death (parthanatos). However, the detail mechanism of MNNG-induced parthanatos was not well-investigated. In this study, we used MNNG-treated mouse embryonic fibroblasts (MEFs) to elucidate the signaling pathways of MNNG-induced parthanatos. We found that MNNG-induced cell death accompanied by rapid PARP-1 activation, c-Jun N-terminal kinase (JNK) activation, biphasic reactive oxygen species (ROS) production and intracellular calcium increase. The early ROS production occurring at 1 min and peaking at 5-15 min after MNNG treatment partially resulted from NADPH oxidase. In contrast, the late phase of ROS production occurring at 30 min and time-dependently increasing up to 6h after MNNG treatment was generated by mitochondria. The antioxidant, NAC can abrogate all phenomena caused by MNNG. Results indicate that the calcium rise was downstream of early ROS production, and was involved in PARP-1 and JNK activation. Moreover, the PARP inhibitor was able to reduce MNNG-induced late-phase ROS production, calcium elevation, and cell death. Results further indicated the involvement of RIP1 in sustained ROS production and calcium increase. We characterized the interactive roles of ROS, calcium, JNK, and RIP1 in MNNG-induced cell death. We found that in addition to the alkylating property previously demonstrated, ROS production triggered by MNNG results in enhanced DNA damage and PARP-1 activation. Moreover, intracellular calcium elevation and ROS production have mutual amplification effects and thus contribute to PARP-1-mediated parthanatos.
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Ling-Ya
LY
Chiu
Feng-Ming
FM
Ho
Shine-Gwo
SG
Shiah
Yung
Y
Chang
Wan-Wan
WW
Lin
D000477:Alkylating Agents / Q000633:toxicity*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism; D004249:DNA Damage; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D008769:Methylnitronitrosoguanidine / Q000633:toxicity*; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D002583:Uterine Cervical Neoplasms / Q000378:metabolism
D000477:Alkylating Agents; D017382:Reactive Oxygen Species; D008769:Methylnitronitrosoguanidine; D011065:Poly(ADP-ribose) Polymerases; D048670:MAP Kinase Kinase 4; D002118:Calcium