Profiling of the Tox21 chemical collection for mitochondrial function to identify compounds that acutely decrease mitochondrial membrane potential.

Paradigms and Technologies
Informatics

Abstract

BACKGROUND: Mitochondrial dysfunction has been implicated in the pathogenesis of a variety of disorders including cancer, diabetes, and neurodegenerative and cardiovascular diseases. Understanding whether different environmental chemicals and druglike molecules impact mitochondrial function represents an initial step in predicting exposure-related toxicity and defining a possible role for such compounds in the onset of various diseases. OBJECTIVES: We sought to identify individual chemicals and general structural features associated with changes in mitochondrial membrane potential (MMP). METHODS: We used a multiplexed [two end points in one screen; MMP and adenosine triphosphate (ATP) content] quantitative high throughput screening (qHTS) approach combined with informatics tools to screen the Tox21 library of 10,000 compounds (~ 8,300 unique chemicals) at 15 concentrations each in triplicate to identify chemicals and structural features that are associated with changes in MMP in HepG2 cells. RESULTS: Approximately 11% of the compounds (913 unique compounds) decreased MMP after 1 hr of treatment without affecting cell viability (ATP content). In addition, 309 compounds decreased MMP over a concentration range that also produced measurable cytotoxicity [half maximal inhibitory concentration (IC50) in MMP assay/IC50 in viability assay ≤ 3; p < 0.05]. More than 11% of the structural clusters that constitute the Tox21 library (76 of 651 clusters) were significantly enriched for compounds that decreased the MMP. CONCLUSIONS: Our multiplexed qHTS approach allowed us to generate a robust and reliable data set to evaluate the ability of thousands of drugs and environmental compounds to decrease MMP. The use of structure-based clustering analysis allowed us to identify molecular features that are likely responsible for the observed activity.

Authors

Attene-Ramos, Matias S; Huang, Ruili; Michael, Samuel; Witt, Kristine L; Richard, Ann; Tice, Raymond R; Simeonov, Anton; Austin, Christopher; Xia, Menghang;

Keywords

  • Adenosine Triphosphate/ analysis
  • Cell Survival
  • Dose-Response Relationship, Drug
  • Environmental Pollutants/ toxicity
  • Hep G2 Cells
  • High-Throughput Screening Assays
  • Humans
  • Membrane Potential, Mitochondrial/ drug effects
  • Toxicity Tests

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