Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 293, Issue 18, Pages 6883-6892Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.RA117.000347
Keywords
CRISPR; Cas; gene therapy; liver; fibrosis; genetic disease; Cas9 nickase; gene editing; genome editing; hereditary tyrosinemia
Categories
Funding
- National Natural Science Foundation of China [81670470, 81600149]
- Shanghai Municipal Commission for Science and Technology [14140901600, 15JC1400201]
Ask authors/readers for more resources
Hereditary tyrosinemia type I (HTI) is a metabolic genetic disorder caused by mutation of fumarylacetoacetate hydrolase (FAH). Because of the accumulation of toxic metabolites, HTI causes severe liver cirrhosis, liver failure, and even hepatocellular carcinoma. HTI is an ideal model for gene therapy, and several strategies have been shown to ameliorate HTI symptoms in animal models. Although CRISPR/Cas9-mediated genome editing is able to correct the Fah mutation in mouse models, WT Cas9 induces numerous undesired mutations that have raised safety concerns for clinical applications. To develop a new method for gene correction with high fidelity, we generated a Fah mutant rat model to investigate whether Cas9 nickase (Cas9n)-mediated genome editing can efficiently correct the Fah. First, we confirmed that Cas9n rarely induces indels in both on-target and off-target sites in cell lines. Using WT Cas9 as a positive control, we delivered Cas9n and the repair donor template/single guide (sg)RNA through adenoviral vectors into HTI rats. Analyses of the initial genome editing efficiency indicated that only WT Cas9 but not Cas9n causes indels at the on-target site in the liver tissue. After receiving either Cas9n or WT Cas9-mediated gene correction therapy, HTI rats gained weight steadily and survived. Fah-expressing hepatocytes occupied over 95% of the liver tissue 9 months after the treatment. Moreover, CRISPR/Cas9-mediated gene therapy prevented the progression of liver cirrhosis, a phenotype that could not be recapitulated in the HTI mouse model. These results strongly suggest that Cas9n-mediated genome editing is a valuable and safe gene therapy strategy for this genetic disease.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available