Dataset Information

Lack of RAN-mediated toxicity in Huntington’s disease knock-in mice

ABSTRACT: Identification of repeat-associated non-AUG (RAN) translation in trinucleotide (CAG) repeat diseases leads to an emerging concept that CAG repeat diseases are caused by non-polyglutamine products. Nonetheless, the exact contribution of RAN translation to the pathogenesis of CAG repeat diseases remains elusive. Via CRISPR/Cas9-mediated genome editing, we established new knock-in mouse models that harbor expanded CAG repeats in the mouse huntingtin gene, which express RAN translated products or polyglutamine products respectively. Here we report that RAN translation is not detected in the knock-in mouse models, and that only the expanded polyglutamine products can cause neuropathology and behavioral phenotypes. Therefore, polyglutamine products, rather than RAN translated products, play a major role in the pathogenesis of CAG repeat diseases.

ORGANISM(S): Mus musculus

PROVIDER: GSE142603 | GEO | 2020/02/03

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Spinocerebellar ataxia type 3 (SCA3) is one of the polyglutamine (polyQ) diseases, which are caused by a CAG repeat expansion within the coding region of the associated genes. The CAG repeat specifies glutamine, and the expanded polyQ domain with mutation confers dominant toxicity on the protein. Traditionally, studies have focused on protein toxicity in polyQ disease mechanisms. Recent findings, however, demonstrate that the CAG repeat RNA, which encodes the toxic polyQ protein, also contributes to the disease in Drosophila. To provide insight into the nature of the RNA toxicity, we extracted brain-enriched RNA from flies expressing a toxic CAG repeat mRNA (CAG100) and a non-toxic interrupted CAA/G mRNA repeat (CAA/G105) for microarray analysis. This approach identified a set of genes that are differentially expressed specifically in CAG100 flies. Four independent replicates of flies expressing CAG0, CAG100, or CAA/G105 by elav-GAL4 were collected at 3 days. The transgenes are DsRed with either (CAG0) no CAG repeat in the 3'UTR, (CAG100) a CAG repeat of 100 CAGs in the 3'UTR, or (CAA/G105) an interrupted CAA CAG repeat in the 3'UTR (ref: Li et al., Nature 453:1107) The transgenes were adjusted to match in mRNA expression such that CAG0 flies had one copy of the transgene, CAG100 flies had 5 copies, and CAA/G105 had two copies. Fly brain tissue (about 20 brains per sample, dissected from head capsule, eyes, lamina and outer medulla removed) was dissected in cold phosphate buffered saline (PBS) and stored in Trizol reagent (Invitrogen Corporation, Carlsbad, CA) at -80Ë?C. Total brain RNA was extracted and purified using TRIzol reagent (Invitrogen) and the RNeasy Mini system (Qiagen), and treated with RNase-free DNase I (Qiagen). To define genes whose expression is altered in response to a toxic CAG repeat RNA, we compared CAG100 flies with age-matched flies expressing CAG0. To exclude transcriptional changes in response to a non-toxic trinucleotide repeat, a second gene list was generated by comparing CAA/G105 flies with age-matched CAG0 flies.

Dataset Information

Lack of RAN-mediated toxicity in Huntington’s disease knock-in mice

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure