Expression data from SCA3 and genetically corrected iPSCs

The neurodegenerative disease spinocerebellar ataxia type 3 (SCA3; also called Machado-Joseph disease, MJD) is a trinucleotide repeat disorder caused by expansion of CAG repeats which encoding an abnormal long polyglutamine (polyQ) tract in ataxin-3 of the ATXN3 gene. Even now the pathogenic mechanism has remained elusive and no cure method is currently available. In this study, we first applied CRISPR/Cas9-mediated approach using homologous recombination to achieve one-step genetic correction in SCA3-specific induced pluripotent stem cells (iPSCs) by adjusting pathological 80 CAG repeats to normal 13 CAG repeats, without detectable off-target based on whole exon sequencing or polyacrylamide gel electrophoresis (PAGE). The correction normalized SCA3 pathogenic signal pathways (like transcription, apoptosis, and ubiquitin-dependent protein catabolic process) and reversed disease-associated phenotypes. Our strategy provides deep insights into pathogenic mechanism of SCA3 disease and suggests potential therapeutic applications of trinucleotide repeat disorders. 6 experimental samples were used overall. There were 3 replicates per group, with one group being the control (SCA3 iPSCs), and the other being the experimental (corrected iPSCs).