CRISPR-Cas9 Screens in Human Cells and Primary Neurons Identify Modifiers of C9ORF72 Dipeptide-repeat-protein Toxicity

Overview

Journal Nat Genet

Specialty Genetics

Date 2018 Mar 7

PMID 29507424

Citations 122

Authors

Nicholas J Kramer

Michael S Haney

David W Morgens

Ana Jovicic

Julien Couthouis

Amy Li

James Ousey

Rosanna Ma

Gregor Bieri

C Kimberly Tsui

Yingxiao Shi

Nicholas T Hertz

Marc Tessier-Lavigne

Justin K Ichida

Michael C Bassik

Aaron D Gitler

Affiliations

Soon will be listed here.

Abstract

Hexanucleotide-repeat expansions in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD). The nucleotide-repeat expansions are translated into dipeptide-repeat (DPR) proteins, which are aggregation prone and may contribute to neurodegeneration. We used the CRISPR-Cas9 system to perform genome-wide gene-knockout screens for suppressors and enhancers of C9ORF72 DPR toxicity in human cells. We validated hits by performing secondary CRISPR-Cas9 screens in primary mouse neurons. We uncovered potent modifiers of DPR toxicity whose gene products function in nucleocytoplasmic transport, the endoplasmic reticulum (ER), proteasome, RNA-processing pathways, and chromatin modification. One modifier, TMX2, modulated the ER-stress signature elicited by C9ORF72 DPRs in neurons and improved survival of human induced motor neurons from patients with C9ORF72 ALS. Together, our results demonstrate the promise of CRISPR-Cas9 screens in defining mechanisms of neurodegenerative diseases.

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