The IGF-1/Akt pathway is neuroprotective in Huntington's disease and involves Huntingtin phosphorylation by Akt

Dev Cell. 2002 Jun;2(6):831-7. doi: 10.1016/s1534-5807(02)00188-0.


In the search for neuroprotective factors in Huntington's disease, we found that insulin growth factor 1 via activation of the serine/threonine kinase Akt/PKB is able to inhibit neuronal death specifically induced by mutant huntingtin containing an expanded polyglutamine stretch. The IGF-1/Akt pathway has a dual effect on huntingtin-induced toxicity, since activation of this pathway also results in a decrease in the formation of intranuclear inclusions of mutant huntingtin. We demonstrate that huntingtin is a substrate of Akt and that phosphorylation of huntingtin by Akt is crucial to mediate the neuroprotective effects of IGF-1. Finally, we show that Akt is altered in Huntington's disease patients. Taken together, these results support a potential role of the Akt pathway in Huntington's disease.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Death
  • Cells, Cultured
  • Corpus Striatum / cytology
  • Enzyme Activation
  • Humans
  • Huntingtin Protein
  • Huntington Disease / genetics
  • Huntington Disease / pathology*
  • Inclusion Bodies / metabolism
  • Insulin-Like Growth Factor I / metabolism*
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / cytology*
  • Neurons / metabolism
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Point Mutation
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • Recombinant Fusion Proteins / metabolism
  • Substrate Specificity


  • HTT protein, human
  • Huntingtin Protein
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Recombinant Fusion Proteins
  • Insulin-Like Growth Factor I
  • AKT1 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt