title: Daphnetin-mediated Nrf2 antioxidant signaling pathways ameliorate tert-butyl hydroperoxide (t-BHP)-induced mitochondrial dysfunction and cell death.
abstract: Daphnetin (Daph), a natural coumarin derivative isolated from plants of the Genus Daphne, possesses abundant biological activities, such as anti-inflammatory, antioxidant and anticancer properties. In the present study, we focused on investigating the protective effect of Daph against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage, mitochondrial dysfunction and the involvement of underlying molecular mechanisms. Our findings indicated that Daph effectively inhibited t-BHP-stimulated cytotoxicity, cell apoptosis, and mitochondrial dysfunction, which are associated with suppressed reactive oxygen species (ROS) generation, decreased malondialdehyde (MDA) formation, increased superoxide dismutase (SOD) levels and glutathione (GSH)/GSSG (oxidized GSH) ratio. Further investigation indicated that Daph significantly suppressed cytochrome c release and NLRP3 inflammasome activation and modulated apoptosis-related protein Bcl-2, Bax, and caspase-3 expression. Moreover, Daph dramatically induced the expression of the glutamate-cysteine ligase modifier (GCLM) subunit and the glutamate-cysteine ligase catalytic (GCLC) subunit, heme oxygenase-1 (HO-1), and NAD (P) H: quinone oxidoreductase (NQO1), which is largely dependent on upregulating the nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation, reducing the Keap1 protein expression, and strengthening the antioxidant response element (ARE) promoter activity. Additionally, Daph remarkably activated a c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) phosphorylation, but ERK and JNK inhibitor pretreatment exhibited an evident decrease of the level of Daph-enhanced Nrf2 nuclear translocation. Furthermore, Daph exposure suppressed t-BHP-induced cytotoxicity and ROS overproduction, which are mostly blocked in Nrf2 knockout RAW 264.7 cells and peritoneal macrophages. Accordingly, Daph exhibited protective roles against t-BHP-triggered oxidative damage and mitochondrial dysfunction by the upregulation of Nrf2 antioxidant signaling pathways, which may be involved in the activation of JNK and ERK.
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China; Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine. Jilin University, Changchun 130061, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Lv
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China.
authors.forename: Qinmei
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China.
authors.forename: Guangyun
authors.initials: G
authors.lastname: Tan
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China; Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine. Jilin University, Changchun 130061, China.
authors.forename: Xuming
authors.initials: X
authors.lastname: Deng
authors.affiliation: Institute of Translational Medicine, The First Hospital, Jilin University, Changchun 130001, China. Electronic address: cixinxin@jlu.edu.cn.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Ci
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics; D000072019:Kelch-Like ECH-Associated Protein 1 / Q000235:genetics; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation; D000067996:RAW 264.7 Cells; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014468:Umbelliferones / Q000008:administration & dosage*; D020122:tert-Butylhydroperoxide / Q000633:toxicity
chemical_list: D000975:Antioxidants; C117301:Keap1 protein, mouse; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D017382:Reactive Oxygen Species; D014468:Umbelliferones; D020122:tert-Butylhydroperoxide; D048031:JNK Mitogen-Activated Protein Kinases; C039952:daphnetin
keywords: Daphnetin; Mitochondrial dysfunction; Nrf2; Oxidative damage; ROS