CRISPR-Cas9 successfully reverses Huntington’s disease in mice.
Studies at Emory University has opened up new understanding on Huntington’s disease, a hereditary genetic disease that results in nerve cell death in the brain, using CRISPR-Cas9 gene editing. The new insights could provide a way to reverse its effects.
With no known cure for Huntinton’s disease, new discoveries made by Chinese scientists at Emory University in Atlanta is creating optimism, with preliminary experiments demonstrating substantial success at preventing the disease from ever developing.
The study is the result of an ongoing joint research collaboration between the U.S. National Institute of Health (NIH) and the National Natural Science Foundation of China, with funding and science personnel coming from both countries.
In the study, researchers replaced the mice’s huntingtin gene with the human huntingtin gene. In about nine months, the mice begun to exhibit motor function problems.
The researchers then used CRISPR-Cas9 delivered via bacteriophages AAV (adeno-associated virus) to replace the mutated huntingtin gene (mHTT, or mutated huntingtin) with a normal gene in the DNA of afflicted mice.
Within weeks, the toxic proteins responsible for damaging nerve cells in the brain, had nearly completely disappeared, and normal motor function of the mice were restored to nearly the same capacity as healthy mice including balance-grip strength. In addition, levels of the bad gene also fell dramatically.
Another study conducted by the Emory researchers also show that mice older than four months do not need the huntingtin gene to stay healthy, which means that it is likely safe to shut off the genes in adult humans and preventing the gene from ever becoming mutated in the first place.
However, researchers will need to address several concerns before CRISPR-Cas9 gene therapy can be used in humans, including the effectiveness of delivery and the safety of modifying DNA in brain cells. The long-term safety of introducing the AAV bacteriophage into brain cells is under intensive tests and study.