title: Modulation of polyglutamine-induced cell death by genes identified by expression profiling.
abstract: The majority of triplet-repeat diseases are caused by mutated genes with an extended polyglutamine tract, exemplified by Huntington's disease (HD). In order to model HD pathogenesis in a controlled system, we developed stable PC12 cell lines that express exon 1 fragments of the huntingtin gene with 23 or 74 polyglutamines driven by an inducible doxycycline (dox)-sensitive promoter (HD-23Q or HD-74Q). We aimed to identify early perturbations induced by the mutation by studying expression levels of 1824 genes at 0, 5, 10 and 18 hours after induction, using adaptor-tagged competitive PCR (ATAC-PCR). At these time points, the cells show no appreciable death or mitochondrial impairment and very low inclusion levels. A total of 126 genes, including 69 known genes, exhibited statistically significant alterations in the HD-74Q cell lines but no changes in the HD-23Q lines. We tested 11 of these genes for their abilities to modulate polyglutamine-induced cell death in transiently transfected cell models. Five genes [glucose transporter 1 (Glut1), phosphofructokinase muscle isozyme (Pfkm), prostate glutathione-S -transferase 2 (Gstm2), RNA-binding motif protein 3 (Rbm3) and KRAB-A interacting protein 1 (Krip-1)] significantly suppressed cell death in both neuronal precursor and non-neuronal cell lines, suggesting that these transcriptional changes were relevant to polyglutamine pathology. The efficient recovery of functionally relevant genes supports the utility of gene expression profiling for discovering pathways related to pathogenesis, and the importance of analyzing molecular events in the early stages of disease.
authors.affiliation: Taisho Laboratory of Functional Genomics, Nara Institute of Science and Technology, Core Research for Evolutional Science and Technology, Japan Science and Technology Corporation, 8916-5 Takayama, Ikoma, Nara, 630-0101, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kita
authors.forename: Jenny
authors.initials: J
authors.lastname: Carmichael
authors.forename: Jina
authors.initials: J
authors.lastname: Swartz
authors.forename: Shizuko
authors.initials: S
authors.lastname: Muro
authors.forename: Andreas
authors.initials: A
authors.lastname: Wyttenbach
authors.forename: Kenichi
authors.initials: K
authors.lastname: Matsubara
authors.forename: David C
authors.initials: DC
authors.lastname: Rubinsztein
authors.forename: Kikuya
authors.initials: K
authors.lastname: Kato
mesh_terms: D000818:Animals; D019556:COS Cells; D016923:Cell Death / Q000502:physiology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010455:Peptides / Q000378:metabolism* / Q000633:toxicity
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010455:Peptides; C097188:polyglutamine