By CGTN's Joshua Barlow
There may be new hope for those suffering from a fatal brain disorder called Huntington’s Disease. Researchers at Emory University, are using a groundbreaking gene editing tool called CRISPR-Cas9 to provide new insight into how the disease works, and possible ways to reverse its devastating effects.
Huntington’s Disease is a genetically inherited condition that leads to nerve cell destruction in the brain. Symptoms which usually appear in mid-life, include uncontrolled muscle movement, balance issues, mood swings and cognitive decline.
While there is no known cure for Huntington’s, a recent study by Chinese scientists at Emory University in Atlanta, Georgia is showing promise. Early results suggest possible treatments for the disease and a path to preventing its occurrence in the first place.
Emory School of Medicine /emory.edu Photo
Emory School of Medicine /emory.edu Photo
The research is part of an ongoing medical collaboration between the US National Institute of Health (NIH) and the National Natural Science Foundation of China. Under this program, both the US and China contribute funds and scientists for research in both countries.
Using the revolutionary gene editing technique known as CRISPR-Cas9, researchers at Emory were able to reverse the effects of Huntington’s in test mice. The mice had been genetically modified to carry a human version of the huntingtin gene that causes the disease. While considered essential for nervous system development in early life, a mutated huntingtin gene can also produce toxic proteins that cause neural generation.
After nine months, when the mice developed the animal version of Huntington’s Disease, researchers used CRISPR-Cas9 to replace the mutant gene with a normal one and then reintroduce the repaired DNA into mice.
CRISPR is a technology that employs a DNA-splitting enzyme along with a highly focused molecular guide that tell those enzymes where to split. /McGovern Institute Photo
CRISPR is a technology that employs a DNA-splitting enzyme along with a highly focused molecular guide that tell those enzymes where to split. /McGovern Institute Photo
Weeks after treatment, the brain-damaging proteins had almost disappeared and motor functions of the mice dramatically improved, though not to the same level in healthy control mice in which Huntington’s hadn’t been induced.
While the results show promise for future human trials involving humans, clinical trials remain a long way off. The long term effectiveness and safety of CRISPR-Cas9 are still under review.
The study’s senior author Dr. Li Xiaojiang, PhD, is optimistic. “The findings open up an avenue for treating Huntington’s as well as other inherited neurodegenerative diseases, although more testing of safety and long-term effects is needed,” said Li.
In addition to developing a treatment for victims of Huntington’s, the Sino-US research group hopes to develop ways to reduce the risk for people who are genetically predisposed to developing Huntington’s.
Last year, the same group of Emory researchers found they could delete the huntingtin gene in mice older than four months without any known adverse effects. Younger mice without this gene developed fatal pancreatitis. The findings suggest it may someday be possible to safely shut off the gene in adult humans, as well.
Full results of the group’s research were published in the Journal of Clinical Investigation on June 19, 2017.