GSBS Dissertations and Theses

ORCID ID

0000-0003-2476-1624

Publication Date

2019-08-09

Document Type

Doctoral Dissertation

Academic Program

Neuroscience

Department

RNA Therapeutics Institute

First Thesis Advisor

Wen Xue

Second Thesis Advisor

Robert H Brown Jr.

Keywords

CRISPR/Cas9, Cas9, Amyotrophic lateral sclerosis, ALS, Motor Neuron Disease, SOD1, superoxide dismutase, gene therapy, gene editing, AAV, adeno associated vector, adeno-associated vector, AAV9

Abstract

Mutations in the SOD1 gene are the best characterized genetic cause of amyotrophic lateral sclerosis (ALS) and account for ~20% of inherited cases and 1-3% of sporadic cases. The gene-editing tool Cas9 can silence mutant genes that cause disease, but effective delivery of CRISPR-Cas9 to the central nervous system (CNS) remains challenging. Here, I developed strategies using canonical Streptococcus pyogenes Cas9 to silence SOD1. In the first strategy, I demonstrate effectiveness of systemic delivery of guide RNA targeting SOD1 to the CNS in a transgenic mouse model expressing human mutant SOD1 and Cas9. Silencing was observed in both the brain and the spinal cord. In the second strategy, I demonstrate the effectiveness of delivering both guide RNA and Cas9 via two AAVs into the ventricles of the brain of SOD1G93A mice. Silencing was observed in the brain and in motor neurons within the spinal cord. For both strategies, treated mice had prolonged survival when compared to controls. Treated mice also had improvements in grip strength and rotarod function. For ICV treated mice, we detected a benefit of SOD1 silencing using net axonal transport assays, a novel method to detect motor neuron function in mice before onset of motor symptoms. These studies demonstrate that Cas9-mediated genome editing can mediate disease gene silencing in motor neurons and warrants further development for use as a therapeutic intervention for SOD1-linked ALS patients.

DOI

10.13028/9qjz-qq07

Rights and Permissions

Copyright is held by the author, with all rights reserved.

Available for download on Friday, February 28, 2020

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