Therapeutic CRISPR/Cas9 Genome Editing in a Humanized Mouse Model Ameliorates α1-antitrypsin Deficiency Phenotype | Chapter 2 | Research Perspectives of Microbiology and Biotechnology Vol. 9

The aim of the study is to evaluate the role of CRISPR/Cas9 Genome Editing in improving α1-Antitrypsin Deficiency Symptoms. α1-antitrypsin (AAT) is a circulating serine protease inhibitor secreted from the liver and important in preventing proteolytic neutrophil elastase associated tissue damage, primarily in lungs. In humans, AAT is encoded by the SERPINA1 (hSERPINA1) gene in which a point mutation (commonly referred to as PiZ) causes aggregation of the miss-folded protein in hepatocytes resulting in subsequent liver damage. Targeting a defective gene in order to cure inherited human disease is an attractive therapeutic option and the stable disruption of SERPINA1 variants in vivo, at the genomic or mRNA level, is a promising strategy to reduce levels of miss-folded AAT protein and ameliorate pathological findings in the liver. In an attempt to rescue the pathologic liver phenotype of a mouse model of human AAT deficiency (AATD), we used adenovirus to deliver Cas9 and a guide-RNA (gRNA) molecule targeting hSERPINA1. Our single dose therapeutic gene editing approach completely reverted the phenotype associated with the PiZ mutation, including circulating transaminase and human AAT (hAAT) protein levels, liver fibrosis and protein aggregation. Furthermore, liver histology was significantly improved regarding inflammation and overall morphology in hSERPINA1 gene edited PiZ mice, which expresses the human SERPINA1 variant. Genomic analysis confirmed significant disruption to the hSERPINA1 transgene resulting in a reduction of hAAT protein levels and quantitative mRNA analysis showed a reduction in fibrosis and hepatocyte proliferation as a result of editing. Currently, available treatment options for patients with AATD are limited and include protein replacement therapy using plasma-derived AAT in lung disease and, in the case of advanced cirrhosis, liver transplantation. Our findings indicate that therapeutic gene editing in hepatocytes is possible in an AATD mouse model.

 

Author (s) Details

 

Mikael Bjursell
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Michelle J. Porritt
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Elke Ericson
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Amir Taheri-Ghahfarokhi
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Maryam Clausen
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Lisa Magnusson|
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Therese AdmyreA
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Roberto Nitsch
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Lorenz Mayr
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Leif AasehaugA
Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Frank Seeliger
Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Marcello Maresca
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Mohammad Bohlooly-Y
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

John Wiseman
Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.

 

Please see the book here:- https://doi.org/10.9734/bpi/rpmab/v9/3611