Transcriptional repression of PGC-1alpha by mutant huntingtin leads to mitochondrial dysfunction and neurodegeneration.
Huntington's disease (HD) is an inherited neurodegenerative disease caused by a glutamine repeat expansion in huntingtin protein. Transcriptional deregulation and altered energy metabolism have been implicated in HD pathogenesis. We report here that mutant huntingtin causes disruption of mitochondrial function by inhibiting expression of PGC-1alpha, a transcriptional coactivator that regulates several metabolic processes, including mitochondrial biogenesis and respiration. Mutant huntingtin represses PGC-1alpha gene transcription by associating with the promoter and interfering with the CREB/TAF4-dependent transcriptional pathway critical for the regulation of PGC-1alpha gene expression. Crossbreeding of PGC-1alpha knockout (KO) mice with HD knockin (KI) mice leads to increased neurodegeneration of striatal neurons and motor abnormalities in the HD mice. Importantly, expression of PGC-1alpha partially reverses the toxic effects of mutant huntingtin in cultured striatal neurons. Moreover, lentiviral-mediated delivery of PGC-1alpha in the striatum provides neuroprotection in the transgenic HD mice. These studies suggest a key role for PGC-1alpha in the control of energy metabolism in the early stages of HD pathogenesis.
Cui
Libin
L
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, MassGeneral Institute for Neurodegeneration, Charlestown, MA 02129 USA.
Jeong
Hyunkyung
H
Borovecki
Fran
F
Parkhurst
Christopher N
CN
Tanese
Naoko
N
Krainc
Dimitri
D
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000166:cytology / Q000378:metabolism; D004734:Energy Metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000378:metabolism / Q000503:physiopathology; D016086:Lentivirus / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008928:Mitochondria / Q000378:metabolism*; D009410:Nerve Degeneration / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic
C506812:Htt protein, mouse; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors