Publication Date

2015-12-07

Document Type

Doctoral Dissertation

Academic Program

Interdisciplinary Graduate Program

Department

Neurology

First Thesis Advisor

Miguel Sena-Esteves, Ph.D.

Keywords

gene therapy, ALS, Amyotrophic Lateral Sclerosis, AAV9 vector, SOD1 gene

Subjects

Dissertations, UMMS; Amyotrophic Lateral Sclerosis; Superoxide Dismutase; MicroRNAs; Dependovirus; Genetic Therapy; Genetic Vectors

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by loss of motor neurons, resulting in progressive muscle weakness, atrophy, paralysis and death within five years of diagnosis. About ten percent of cases are inherited, of which twenty percent are due to mutations in the superoxide dismutase 1 (SOD1) gene. Since the only FDA approved ALS drug prolongs survival by just a few months, new therapies for this disease are needed. Experiments in transgenic ALS mouse models have shown that decreasing levels of mutant SOD1 protein alters and in some cases entirely prevents disease progression. We explored this potential therapeutic approach by using a single stranded AAV9 vector encoding an artificial microRNA against human SOD1 injected bilaterally into the cerebral lateral ventricles of neonatal SOD1G93A mice. This therapy extended median survival from 135 to 206 days (a 50% increase) and delayed hind limb paralysis. Animals remained ambulatory until endpoint, as defined by a sharp drop in body weight. Treated animals had a reduction of mutant human SOD1 mRNA levels in upper and lower motor neurons. As compared to untreated SOD1G93A mice, the AAV9 treated mice also had significant improvements in multiple parameters including the number of motor neurons, diameter of ventral root axons, and degree of neuroinflammation in the spinal cord. These studies clearly show that an AAV9-delivered artificial microRNA is a translatable therapeutic approach for ALS.

Comments

This dissertation includes 4 multimedia files that are available under "Additional Files."

DOI

10.13028/M2CS3M

Rights and Permissions

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

Additional Files
Movie 2.1A.mov (3962 kB)
Movie 2.1A. An untreated SOD1G93A mouse at 135 days shows signs of hind limb paralysis.
Movie 2.1B.mov (1113 kB)
Movie 2.1B. An AAV9-amiRNA treated SOD1G93A mouse at its humane endpoint (>200 days) is thin and has signs of kyphosis.
Movie 2.1C.mov (2923 kB)
Movie 2.1C. An AAV9-amiRNA treated SOD1G93A mouse at 198 days does not show signs of paralysis, or any movement impairment.
Movie 2.1D.mov (4609 kB)
Movie 2.1D. An AAV9-amiRNA treated SOD1G93A mouse at its humane endpoint (>200 days) is still able to climb and hang from a metal food hopper.
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