Gene editing therapy has made another milestone when it successfully improved the memory and cognitive functions of mice under the study of scientists at Dongguk University in Seoul, South Korea. This brings mankind a step closer to the treatment of Alzheimer’s patients. In just a few short weeks, the researchers were able to treat the neurodegenerative disease in mice by removing faulty genes at their source which may halt or even reverse disease progression depending on further studies.
An Incurable Progressive Disease
Alzheimer’s disease is a type of dementia that interferes with one’s memory, thinking, and behavior. Its symptoms usually develop slowly and get worse over time and may become severe enough to interfere with the performance of daily tasks. In its early stages, memory loss of patients inflicted with the disease is mild, but as it progresses, late-stage Alzheimer’s is capable of making individuals lose the ability to carry on a conversation and even respond to their environment. According to studies, a person with Alzheimer’s lives four to eight years after diagnosis on average but can live as long as 20 years, depending on a lot of factors. What exactly causes this type of memory loss and cognitive disability?
A Plaque in the Brain
People inflicted with Alzheimer’s disease have amyloid-β proteins accumulation on the outsides of neurons or nerve cells and acts as plaques in the brain. Dr. Jongpil Kim and his colleagues from Korea and the USA attempted to edit out the BACE 1 gene—commonly associated with Alzheimer’s disease—in the neurons of the adult mouse brain. This is the first in vivo attempt at testing the effectiveness of CRISPR-Cas9 in stopping Alzheimer’s progression which remains to be an incurable human disease. Along with Alzheimer’s, Dr. Kim’s team hopes to develop treatments for other forms of dementia including Parkinson’s using CRISPR-Cas9 technology.
The study took 8 to 12 weeks to complete, with the treatment focused on the plaque that surrounds the affected neurons in the mice. As the research progressed, the subjects showed a dramatic decrease in plaque, better associative learning and spatial working memory, and improved cognitive functions. In addition, tests showed no evidence of increasing mutations in non-targeted parts of the genome. This means the expected side-effects are minimal.
Gene Editing Therapy Irreversible
Dr. Kim, however, warns that gene editing cannot be undone. This is why it is important to make sure that the applied gene therapy will not cause any detrimental and rare, genomic alterations. Thereby more research on the technique should be done before applying it to human subjects. On the other hand, the scientist is very hopeful that their successful research using CRISPR-Cas9 on mice is a promising option for the treatment of human neurodegenerative diseases.