Neuroprotective role of Sirt1 in mammalian models of Huntington's disease through activation of multiple Sirt1 targets.

TitleNeuroprotective role of Sirt1 in mammalian models of Huntington's disease through activation of multiple Sirt1 targets.
Publication TypeJournal Article
Year of Publication2012
AuthorsJiang, M, Wang J, Fu J, Du L, Jeong H, West T, Xiang L, Peng Q, Hou Z, Cai H, Seredenina T, Arbez N, Zhu S, Sommers K, Qian J, Zhang J, Mori S, Yang WX, Tamashiro KLK, Aja S, Moran TH, Luthi-Carter R, Martin B, Maudsley S, Mattson MP, Cichewicz RH, Ross CA, Holtzman DM, Krainc D, Duan W
JournalNature medicine
Date Published2012 Jan
KeywordsAnimals, Brain, Brain-Derived Neurotrophic Factor, Disease Models, Animal, Dopamine and cAMP-Regulated Phosphoprotein 32, Forkhead Transcription Factors, Gene Expression Regulation, Humans, Huntington Disease, Mice, Nerve Tissue Proteins, Neurons, Nuclear Proteins, Rats, Receptor, trkB, Signal Transduction, Sirtuin 1

Huntington's disease is a fatal neurodegenerative disorder caused by an expanded polyglutamine repeat in huntingtin (HTT) protein. We previously showed that calorie restriction ameliorated Huntington's disease pathogenesis and slowed disease progression in mice that model Huntington's disease (Huntington's disease mice). We now report that overexpression of sirtuin 1 (Sirt1), a mediator of the beneficial metabolic effects of calorie restriction, protects neurons against mutant HTT toxicity, whereas reduction of Sirt1 exacerbates mutant HTT toxicity. Overexpression of Sirt1 improves motor function, reduces brain atrophy and attenuates mutant-HTT-mediated metabolic abnormalities in Huntington's disease mice. Further mechanistic studies suggested that Sirt1 prevents the mutant-HTT-induced decline in brain-derived neurotrophic factor (BDNF) concentrations and the signaling of its receptor, TrkB, and restores dopamine- and cAMP-regulated phosphoprotein, 32 kDa (DARPP32) concentrations in the striatum. Sirt1 deacetylase activity is required for Sirt1-mediated neuroprotection in Huntington's disease cell models. Notably, we show that mutant HTT interacts with Sirt1 and inhibits Sirt1 deacetylase activity, which results in hyperacetylation of Sirt1 substrates such as forkhead box O3A (Foxo3a), thereby inhibiting its pro-survival function. Overexpression of Sirt1 counteracts the mutant-HTT-induced deacetylase deficit, enhances the deacetylation of Foxo3a and facilitates cell survival. These findings show a neuroprotective role for Sirt1 in mammalian Huntington's disease models and open new avenues for the development of neuroprotective strategies in Huntington's disease.

Alternate JournalNat. Med.