title: Antifungal drug itraconazole targets VDAC1 to modulate the AMPK/mTOR signaling axis in endothelial cells.
abstract: Itraconazole, a clinically used antifungal drug, was found to possess potent antiangiogenic and anticancer activity that is unique among the azole antifungals. Previous mechanistic studies have shown that itraconazole inhibits the mechanistic target of rapamycin (mTOR) signaling pathway, which is known to be a critical regulator of endothelial cell function and angiogenesis. However, the molecular target of itraconazole that mediates this activity has remained unknown. Here we identify the major target of itraconazole in endothelial cells as the mitochondrial protein voltage-dependent anion channel 1 (VDAC1), which regulates mitochondrial metabolism by controlling the passage of ions and small metabolites through the outer mitochondrial membrane. VDAC1 knockdown profoundly inhibits mTOR activity and cell proliferation in human umbilical vein cells (HUVEC), uncovering a previously unknown connection between VDAC1 and mTOR. Inhibition of VDAC1 by itraconazole disrupts mitochondrial metabolism, leading to an increase in the cellular AMP:ATP ratio and activation of the AMP-activated protein kinase (AMPK), an upstream regulator of mTOR. VDAC1-knockout cells are resistant to AMPK activation and mTOR inhibition by itraconazole, demonstrating that VDAC1 is the mediator of this activity. In addition, another known VDAC-targeting compound, erastin, also activates AMPK and inhibits mTOR and proliferation in HUVEC. VDAC1 thus represents a novel upstream regulator of mTOR signaling in endothelial cells and a promising target for the development of angiogenesis inhibitors.
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205;
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Head
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205; Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701;
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205;
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205;
authors.forename: Kirill
authors.initials: K
authors.lastname: Gorshkov
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205; Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637551;
authors.forename: Kalyan
authors.initials: K
authors.lastname: Pasunooti
authors.affiliation: Ben May Department of Cancer Research, The University of Chicago, Chicago, IL 60637;
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Ben May Department of Cancer Research, The University of Chicago, Chicago, IL 60637;
authors.forename: Zhiyou
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205;
authors.forename: Ruo-jing
authors.initials: RJ
authors.lastname: Li
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205; Faculty of Health Sciences, University of Macau, Taipa, Macau Special Administrative Region, China;
authors.forename: Joong Sup
authors.initials: JS
authors.lastname: Shim
authors.affiliation: Department of Biology, University of Maryland, College Park, MD 20742;
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Tan
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205;
authors.forename: Thomas
authors.initials: T
authors.lastname: Hartung
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205;
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Ben May Department of Cancer Research, The University of Chicago, Chicago, IL 60637;
authors.forename: Yingming
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Biology, University of Maryland, College Park, MD 20742;
authors.forename: Marco
authors.initials: M
authors.lastname: Colombini
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205; Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205 joliu@jhu.edu.
authors.forename: Jun O
authors.initials: JO
authors.lastname: Liu
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D008933:Mitochondrial Swelling / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D034622:RNA Interference; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D050995:Voltage-Dependent Anion Channel 1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; C494762:VDAC1 protein, human; D017964:Itraconazole; D050995:Voltage-Dependent Anion Channel 1; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases
keywords: VDAC1; angiogenesis; itraconazole; metabolism; mitochondria