For the first time, University of California, Berkeley scientists have used CRISPR-Cas9 gene editing to disable a defective gene that causes amyotrophic lateral sclerosis, or Lou Gehrig’s disease, in mice, extending their lifespan by 25 percent. This step toward a CRISPR-Cas9 intervention for human ALS was reported in Science Advances on December 20, 2017. The team was led by David Schaffer, faculty scientist in the Molecular Biophysics and Integrated Bioimaging Division, who is also a professor of chemical and biomolecular engineering and director of the Berkeley Stem Cell Center.
In this study, mice were genetically engineered to express a mutated human gene, superoxide dismutase 1 (SOD1), found to cause approximately 20 percent of all inherited forms of Lou Gehrig’s Disease. The scientists showed that they could “rescue” the mutation by introducing Cas9 to brain and spinal cord cells using a specifically evolved adeno-associated virus. The action of Cas9 to destroy the mutated SOD1 gene delayed onset of symptoms and prolonged survival. Future efforts are focused on delivering Cas9 to other types of nervous system cells, modifying the Cas9 protein to reduce any possibility of off-target effects, and further optimizing the AAV to deliver a variety of molecules to any kind of tissue. For more, read the UC Berkeley News article.