A small-molecule scaffold induces autophagy in primary neurons and protects against toxicity in a Huntington disease model

Proc Natl Acad Sci U S A. 2010 Sep 28;107(39):16982-7. doi: 10.1073/pnas.1004498107. Epub 2010 Sep 10.

Abstract

Autophagy is an intracellular turnover pathway. It has special relevance for neurodegenerative proteinopathies, such as Alzheimer disease, Parkinson disease, and Huntington disease (HD), which are characterized by the accumulation of misfolded proteins. Although induction of autophagy enhances clearance of misfolded protein and has therefore been suggested as a therapy for proteinopathies, neurons appear to be less responsive to classic autophagy inducers than nonneuronal cells. Searching for improved inducers of neuronal autophagy, we discovered an N(10)-substituted phenoxazine that, at proper doses, potently and safely up-regulated autophagy in neurons in an Akt- and mTOR-independent fashion. In a neuron model of HD, this compound was neuroprotective and decreased the accumulation of diffuse and aggregated misfolded protein. A structure/activity analysis with structurally similar compounds approved by the US Food and Drug Administration revealed a defined pharmacophore for inducing neuronal autophagy. This pharmacophore should prove useful in studying autophagy in neurons and in developing therapies for neurodegenerative proteinopathies.

Publication types

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

MeSH terms

  • Animals
  • Autophagy*
  • Cells, Cultured
  • Cytoprotection*
  • Drug Approval
  • Huntington Disease / metabolism*
  • Huntington Disease / pathology
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Mice
  • Neurons / drug effects*
  • Neuroprotective Agents / pharmacology*
  • Oxazines / chemistry
  • Oxazines / pharmacology*
  • Protein Folding
  • Protein-Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • TOR Serine-Threonine Kinases

Substances

  • 10-(4'-(N-diethylamino)butyl)-2-chlorophenoxazine
  • Intracellular Signaling Peptides and Proteins
  • Neuroprotective Agents
  • Oxazines
  • phenoxazine
  • TOR Serine-Threonine Kinases
  • mTOR protein, mouse
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt