Mutant huntingtin-impaired degradation of beta-catenin causes neurotoxicity in Huntington's disease.
Huntington's disease (HD) is a fatal neurodegenerative disorder causing selective neuronal death in the brain. Dysfunction of the ubiquitin-proteasome system may contribute to the disease; however, the exact mechanisms are still unknown. We report here a new pathological mechanism by which mutant huntingtin specifically interferes with the degradation of beta-catenin. Huntingtin associates with the beta-catenin destruction complex that ensures its equilibrated degradation. The binding of beta-catenin to the destruction complex is altered in HD, leading to the toxic stabilization of beta-catenin. As a consequence, the beta-transducin repeat-containing protein (beta-TrCP) rescues polyglutamine (polyQ)-huntingtin-induced toxicity in striatal neurons and in a Drosophila model of HD, through the specific degradation of beta-catenin. Finally, the non-steroidal anti-inflammatory drug indomethacin that decreases beta-catenin levels has a neuroprotective effect in a neuronal model of HD and in Drosophila and increases the lifespan of HD flies. We thus suggest that restoring beta-catenin homeostasis in HD is of therapeutic interest.
Institut Curie, Orsay, France.
Juliette D
JD
Godin
Ghislaine
G
Poizat
Miriam A
MA
Hickey
Florence
F
Maschat
Sandrine
S
Humbert
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism; D051186:Armadillo Domain Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D007213:Indomethacin / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008875:Middle Aged; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism*
C495305:ARM protein, Drosophila; D000894:Anti-Inflammatory Agents, Non-Steroidal; D051186:Armadillo Domain Proteins; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; C086055:HTT protein, human; C506812:Htt protein, mouse; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010455:Peptides; D014157:Transcription Factors; D051176:beta Catenin; C110233:slmb protein, Drosophila; C097188:polyglutamine; D044767:Ubiquitin-Protein Ligases; D007213:Indomethacin