1. Antifungal drug itraconazole targets VDAC1 to modulate the AMPK/mTOR signaling axis in endothelial cells
- Author
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Zhiyou Deng, Marco Colombini, Yue Chen, Wei Shi, Ruo-Jing Li, Joong Sup Shim, Jin Zhang, Sarah A. Head, Thomas Hartung, Yingming Zhao, Kalyan Kumar Pasunooti, Liang Zhao, Kirill Gorshkov, Jun O. Liu, Wenzhi Tan, and School of Biological Sciences
- Subjects
Antifungal Agents ,Angiogenesis ,Antifungal drug ,Biology ,AMP-Activated Protein Kinases ,Rats, Sprague-Dawley ,AMP-activated protein kinase ,Cell Line, Tumor ,Fluorescence Resonance Energy Transfer ,Human Umbilical Vein Endothelial Cells ,Animals ,Humans ,Phosphorylation ,Mechanistic target of rapamycin ,PI3K/AKT/mTOR pathway ,Cells, Cultured ,Cell Proliferation ,Multidisciplinary ,TOR Serine-Threonine Kinases ,Voltage-Dependent Anion Channel 1 ,RPTOR ,AMPK ,Cell biology ,Mitochondria ,Enzyme Activation ,VDAC1 ,Metabolism ,HEK293 Cells ,PNAS Plus ,Microscopy, Fluorescence ,biology.protein ,RNA Interference ,Itraconazole ,Mitochondrial Swelling ,HeLa Cells ,Signal Transduction - 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.
- Published
- 2015