title: RIP1-mediated mitochondrial dysfunction and ROS production contributed to tumor necrosis factor alpha-induced L929 cell necroptosis and autophagy.
abstract: Tumor necrosis factor alpha (TNFα) induces necroptosis and autophagy; however, the detailed molecular mechanism is not fully understood. In this study, we found that TNFα administration caused mitochondrial dysfunction and reactive oxygen species (ROS) production, which led to necroptosis and autophagy in murine fibrosarcoma L929 cells. Notably, the RIP1 (serine-threonine kinase receptor-interacting protein 1, a main adaptor protein of necroptosis) specific inhibitor necrostatin-1 (Nec-1) recovered mitochondrial dysfunction and ROS production due to TNFα administration. Moreover, pan-caspase inhibitor z-VAD-fmk (zVAD) increased RIP1 expression and exacerbated TNFα-induced mitochondrial dysfunction and ROS production, indicating that RIP1 led to mitochondrial dysfunction and ROS production. In addition, cytochrome c release from mitochondria was accompanied with TNFα administration, and Nec-1 blocked the release of cytochrome c upon TNFα administration, while zVAD enhanced the release. These further suggested that RIP1 induced mitochondrial dysfunction accompanied with cytochrome c release. Furthermore, autophagy inhibitor 3-methyladenine (3MA) did not affect RIP1 expression as well as mitochondrial dysfunction and ROS production. Together with our previous publication that autophagy was a downstream consequence of necroptosis, we concluded that TNFα induced mitochondrial dysfunction accompanied with ROS production and cytochrome c release via RIP1, leading to necroptosis and resulting autophagic cell death.
authors.affiliation: China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Yuan-Chao
authors.initials: YC
authors.lastname: Ye
authors.forename: Hong-Ju
authors.initials: HJ
authors.lastname: Wang
authors.forename: Lu
authors.initials: L
authors.lastname: Yu
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Tashiro
authors.forename: Satoshi
authors.initials: S
authors.lastname: Onodera
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikejima
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000968:Antimycin A; D001343:Autophagy; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects* / Q000502:physiology*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008928:Mitochondria / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012402:Rotenone; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D020690:GTPase-Activating Proteins; C490620:Ralbp1 protein, mouse; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D012402:Rotenone; D000968:Antimycin A; D045304:Cytochromes c