title: β-Lapachone increases phase II antioxidant enzyme expression via NQO1-AMPK/PI3K-Nrf2/ARE signaling in rat primary astrocytes.
abstract: β-Lapachone (β-LAP) is a naturally occurring quinine that exerts a number of pharmacological actions including antibacterial, antifungal, antimalarial, and antitumor activities. In the present study, we investigated whether β-LAP has an antioxidant effect in rat primary astrocytes. β-LAP suppressed intracellular reactive oxygen species (ROS) production induced by hydrogen peroxide and inhibited astroglial cell death. It also increased astrocytic expression of phase II antioxidant enzymes such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), manganese superoxide dismutase (MnSOD), and catalase. Further mechanistic studies revealed that β-LAP activated AMPK and Akt, and pretreatment of cells with an AMPK inhibitor (compound C) or PI3K/Akt inhibitor (LY294002) suppressed β-LAP-induced antioxidant enzyme expression by inhibiting Nrf2/antioxidant response element (ARE) signaling. Compound C also decreased Akt phosphorylation, suggesting that AMPK is upstream of PI3K/Akt. Furthermore, the AMPK activator 5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside mimicked the effect of β-LAP by increasing Akt phosphorylation and ARE-mediated transcription, suggesting that AMPK plays a pivotal role in β-LAP-mediated antioxidant enzyme expression. Because β-LAP effects are usually associated with NQO1 activity, we examined the effect of NQO1 knockdown on antioxidant enzyme expression. Small interfering RNA (siRNA) specific for NQO1 inhibited β-LAP-induced AMPK/Akt phosphorylation and downstream antioxidant enzyme expression. Collectively, the results suggest that β-LAP increases antioxidant enzyme gene expression in astrocytes by modulating NQO1-AMPK/PI3K-Nrf2/ARE signaling.
authors.affiliation: Department of Molecular Medicine, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul, Republic of Korea.
authors.forename: Jin-Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Molecular Medicine, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul, Republic of Korea.
authors.forename: Yu-Young
authors.initials: YY
authors.lastname: Lee
authors.affiliation: Department of Molecular & Life Sciences, Hanyang University, Republic of Korea.
authors.forename: Jisun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Molecular & Life Sciences, Hanyang University, Republic of Korea. Electronic address: hseo@hanyang.ac.kr.
authors.forename: Hyemyung
authors.initials: H
authors.lastname: Seo
authors.affiliation: Department of Molecular Medicine, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul, Republic of Korea. Electronic address: hskimp@ewha.ac.kr.
authors.forename: Hee-Sun
authors.initials: HS
authors.lastname: Kim
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002867:Chromones / Q000008:administration & dosage; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D050217:Metabolic Detoxication, Phase II / Q000235:genetics; D009025:Morpholines / Q000008:administration & dosage; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics* / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics* / Q000378:metabolism; D009285:Naphthoquinones / Q000008:administration & dosage*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D055372:AMP-Activated Protein Kinases; D000975:Antioxidants; D002265:Carboxylic Ester Hydrolases; D002867:Chromones; D006861:Hydrogen Peroxide; D009025:Morpholines; D016660:NAD(P)H Dehydrogenase (Quinone); D051267:NF-E2-Related Factor 2; D009285:Naphthoquinones; D019869:Phosphatidylinositol 3-Kinases; D017382:Reactive Oxygen Species; C495637:Nfe2l2 protein, rat; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C014638:beta-lapachone; C507703:NQO1 protein, rat; C568305:Prkaa1 protein, rat; C019734:arylesterase
keywords: AMPK; Astrocyte; NQO1; Nrf2/ARE signaling; Phase II antioxidant enzyme; β-Lapachone