Small molecule regulators of autophagy identified by an image-based high-throughput screen

Proc Natl Acad Sci U S A. 2007 Nov 27;104(48):19023-8. doi: 10.1073/pnas.0709695104. Epub 2007 Nov 16.

Abstract

Autophagy is a lysosome-dependent cellular catabolic mechanism mediating the turnover of intracellular organelles and long-lived proteins. Reduction of autophagy activity has been shown to lead to the accumulation of misfolded proteins in neurons and may be involved in chronic neurodegenerative diseases such as Huntington's disease and Alzheimer's disease. To explore the mechanism of autophagy and identify small molecules that can activate it, we developed a series of high-throughput image-based screens for small-molecule regulators of autophagy. This series of screens allowed us to distinguish compounds that can truly induce autophagic degradation from those that induce the accumulation of autophagosomes as a result of causing cellular damage or blocking downstream lysosomal functions. Our analyses led to the identification of eight compounds that can induce autophagy and promote long-lived protein degradation. Interestingly, seven of eight compounds are FDA-approved drugs for treatment of human diseases. Furthermore, we show that these compounds can reduce the levels of expanded polyglutamine repeats in cultured cells. Our studies suggest the possibility that some of these drugs may be useful for the treatment of Huntington's and other human diseases associated with the accumulation of misfolded proteins.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autophagy / drug effects*
  • Calcium Channel Blockers / pharmacology
  • Cell Line, Tumor
  • Drug Evaluation, Preclinical / instrumentation
  • Drug Evaluation, Preclinical / methods*
  • Fluspirilene / pharmacology
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Green Fluorescent Proteins / analysis*
  • Humans
  • Intracellular Membranes / chemistry
  • Loperamide / pharmacology
  • Microtubule-Associated Proteins / analysis*
  • Mycotoxins / pharmacology
  • Peptides / metabolism
  • Phagosomes / chemistry
  • Phagosomes / drug effects*
  • Phosphatidylinositol Phosphates / metabolism
  • Pimozide / pharmacology
  • Protein Kinases / metabolism
  • Recombinant Fusion Proteins / analysis
  • Sirolimus / pharmacology
  • Small Molecule Libraries / pharmacology*
  • TOR Serine-Threonine Kinases
  • Trifluoperazine / pharmacology
  • Zinc Fingers / physiology

Substances

  • Calcium Channel Blockers
  • MAP1LC3A protein, human
  • Microtubule-Associated Proteins
  • Mycotoxins
  • Peptides
  • Phosphatidylinositol Phosphates
  • Recombinant Fusion Proteins
  • Small Molecule Libraries
  • phosphatidylinositol 3,4,5-triphosphate
  • Green Fluorescent Proteins
  • Pimozide
  • Trifluoperazine
  • polyglutamine
  • tremortin
  • Loperamide
  • Fluspirilene
  • Protein Kinases
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Sirolimus