Decreased cAMP response element-mediated transcription: an early event in exon 1 and full-length cell models of Huntington's disease that contributes to polyglutamine pathogenesis.
Huntington's disease (HD) is one of nine neurodegenerative diseases caused by an expanded polyglutamine (polyQ) tract within the disease protein. To characterize pathways induced early in HD, we have developed stable inducible PC12 cell lines expressing wild-type or mutant forms of huntingtin exon 1 fragments or the full-length huntingtin protein. Three cAMP response element-binding protein (CREB)-binding protein-dependent transcriptional pathways, regulated by cAMP response element (CRE), retinoic acid response element, and nuclear factor kappaB, show abnormalities in our exon 1 cell model. Of these, the CRE pathway shows the earliest disruption and is significantly down-regulated as early as 12 h following mutant htt transgene induction. This pathway is also the only one of the three that is similarly perturbed in our full-length HD model, where it is also down-regulated at an early time point, compatible with observations in HD brains. Reduced CRE-dependent transcription may contribute to polyQ disease pathogenesis because overexpression of transcriptionally active CREB, but not an inactive form of the protein, is able to protect against polyQ-induced cell death and reduce aggregation.
Sugars
Katharine L
KL
Department of Medical Genetics, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, United Kingdom.
Brown
Rosemary
R
Cook
Lynnette J
LJ
Swartz
Jina
J
Rubinsztein
David C
DC
D000818:Animals; D017209:Apoptosis; D019556:COS Cells; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D005091:Exons; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016716:PC12 Cells; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D014158:Transcription, Genetic; D014162:Transfection
D017362:Cyclic AMP Response Element-Binding Protein; C086055:HTT protein, human; C499524:Htt protein, rat; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D010455:Peptides; C097188:polyglutamine