CRISPR/Cas9-Mediated Gene Correction to Understand ALS

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by the death of motor neurons in the spinal cord and brainstem. ALS has a diverse genetic origin; at least 20 genes have been shown to be related to ALS. Most familial and sporadic cases of ALS are caused by variants of the SOD1, C9orf72, FUS, and TARDBP genes. Genome editing using clustered regularly interspaced short palindromic repeats/CRISPR-associated system 9 (CRISPR/Cas9) can provide insights into the underlying genetics and pathophysiology of ALS. By correcting common mutations associated with ALS in animal models and patient-derived induced pluripotent stem cells (iPSCs), CRISPR/Cas9 has been used to verify the effects of ALS-associated mutations and observe phenotype differences between patient-derived and gene-corrected iPSCs. This technology has also been used to create mutations to investigate the pathophysiology of ALS. Here, we review recent studies that have used CRISPR/Cas9 to understand the genetic underpinnings of ALS.

Keywords: CRISPR/Cas9; amyotrophic lateral sclerosis (ALS); gene correction; induced pluripotent stem cells (iPSCs).

Figure 1

Genetic causes of amyotrophic lateral sclerosis (ALS). (a) Prevalence of familial and sporadic ALS cases. (b) Proportion of causative genes in familial and sporadic ALS [25].

Figure 2

Strategy of clustered regularly interspaced short palindromic repeats/CRISPR-associated system 9 (CRISPR/Cas9)-mediated gene correction. (a) Patient-derived induced pluripotent stem cells (iPSCs) were used to perform gene correction. Isogenic cell line was generated to investigate phenotypic changes comparing iPSCs with genetic mutation; (b) A point mutation was target specific corrected using a donor via homology-directed repair (HDR) mechanism; (c) Repeat expansion in C9orf72 was deleted with two sgRNAs.