title: NADPH oxidase-dependent and -independent mechanisms of reported inhibitors of reactive oxygen generation.
abstract: NADPH oxidase isoform-2 (NOX2) generates reactive oxygen species (ROS) that contribute to neurodegenerative and cardiovascular pathologies. However, validation of NOX2 as a pharmacotherapeutic target has been hampered by a lack of mechanistically-defined inhibitors. Using cellular and biochemical assays, we explored previously reported inhibitors of ROS production (perhexiline, suramin, VAS2870 and two Shionogi patent compounds) as direct NOX2 inhibitors. All but suramin, which presumably lacks cell penetrance, inhibit cellular ROS production. However, only perhexiline and suramin inhibit biochemical NOX2 activity. Indeed, our data suggest that NOX2 inhibition by perhexiline may contribute significantly to its demonstrated cardioprotective effects. Inhibition of protein kinase CβII explains the cellular activity of the Shionogi compounds, whereas VAS2870 inhibits by an as-yet unidentified mechanism unrelated to direct NOX2 function or subunit assembly. These data delineate the mechanisms of action of these compounds and highlight their strengths and limitations for use in future target validation studies.
authors.affiliation: Metabolic Pathways and Cardiovascular Therapeutic Area Unit, GlaxoSmithKline Pharmaceuticals, King of Prussia, PA 19406, USA. greg.j.gatto@gsk.com
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Gatto
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Ao
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kearse
authors.forename: Mei
authors.initials: M
authors.lastname: Zhou
authors.forename: Cyndi R
authors.initials: CR
authors.lastname: Morales
authors.forename: Erin
authors.initials: E
authors.lastname: Daniels
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Bradley
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Goserud
authors.forename: Krista B
authors.initials: KB
authors.lastname: Goodman
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Douglas
authors.forename: Mark R
authors.initials: MR
authors.lastname: Harpel
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Johns
mesh_terms: D001483:Base Sequence; D001583:Benzoxazoles / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010480:Perhexiline / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D064546:Protein Kinase C beta; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013498:Suramin / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
chemical_list: C511179:3-benzyl-7-(2-benzoxazolyl)thio-1,2,3-triazolo(4,5-d)pyrimidine; D001583:Benzoxazoles; D002317:Cardiovascular Agents; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D014230:Triazoles; D013498:Suramin; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D010480:Perhexiline