Ipsc-based crispr/cas9 gene therapy

Reza Kouchaki,1,* Amirhosein maali,2

1. Faculty of Allied Medicine, Qazvin University of Medical Sciences, Qazvin. Iran
2. Department of Medical Biotechnology, Faculty of Medicine,Babol University of Medical Sciences, Babol, Iran

Abstract

Introduction

Clustered regularly interspaced short palindromic repeats (crispr) is a microbial adaptive immune system to cleave foreign genetics elements and has been widely used in gene therapy of hereditary diseases. in a crispr/cas9 system, cas9 acts as a nuclease that is linked to a site-specific-binding rna (crispr). combination of crispr/cas9, as a site-specific nuclease, with induced pluripotent stem cells (ipsc), as an evolution in regenerative medicine, introduced a promising tool to gene therapy of monogenic hereditary disorders that was untreatable so far. the application of this technology can help us to characterize the genetic variation involved in various human disease and find a safe method to correct them.

Methods

Searching for “ipsc-based gene therapy by crispr/cas9” in pubmed, scopus, and google scholar databases resulted in 1700 articles published between 2013 and 2018. of these, 15 closely related articles were analyzed and used to our presented article

Results

Cystic fibrosis (cf) is a progressive genetic disease that leads to lung infections, pancreas, liver, kidneys and intestine disorders. homology-directed repair (hdr)-mediated correction of cftr Δf508 mutation has been done on cf patient-derived ipscs by crisper/cas9 technology, delivered via the plasmid. it led to the corrected expression pattern of cftr on the cells. hemophilia a is a genetic deficiency in clotting factor viii which leads to bleeding and unwanted hemorrhagia. non-homologous end joining (nhej)-mediated correction of hf8 inversion (as target gene) has been done on patient ipsc via plasmid, cas9, and grna delivery system and crispr/cas9 gene editing technology. sickle cell anemia and β-thalassemia (as a defected hemoglobin disorder) have also been corrected the defective gene (hbb) by a similar method. ipsc-based crispr/cas9 can be a novel method to treat leukemia and correcting the hereditary defective genes in patient-derived cells. hiv is the most common virus that causes secondary immunodeficiency (sid) by inserting themselves to the cd4+ cells expressed ccr5 and cxcr4. ye et al. disrupted the ccr5 locus by nhej-mediated method. in this study crispr as a nuclease has been introduced to normal ipsc via aav delivery system hu et al. also disrupted the ltr u3 region of viral genes by the nhej-mediated crispr technology on the cell-lines (chme5, hela, tzm-b1, u1). duchenne muscular dystrophy (dmd) is a genetic disorder characterized by the severe muscular disorder. lee et al. corrected exon 45 of dmd gene by disruption of the splicing receptor to skip exon45, nhej restoration of reading frame and hdr-mediated exon 44 cdna knock in, by talen/crisper technology on patient-derived ipsc. alzheimer, as the most common cause of dementia, is a gene-related chronic neurodegenerative disease. in 2017, the psen2 n141i mutation in ipsc-derived alzheimer neurons corrected by crispr/cas9-based methods.

Conclusion

Crisper/cas9 technology is a promising tool for gene editing in ipscs alongside zfn, talen, meganuclease and other modified nucleases. this method can be used in the various human genetic diseases that are untreatable to human so far. crispr/cas9 will allow us to improve the genomic variation in disease prosses, especially in monogenic hereditary disorders

Keywords

Induced pluripotent stem cell, crispr/cas9, gene editing, gene therapy