Gene Editing, a tool for editing a human DNA, may soon help alleviate the Obesity crisis that affects millions of U.S. adults.
A major research conducted by scientists from the University of California, San Francisco indicates how CRISPRa ("a" stands for activation) can be used to amplify the genes that curb human appetite for food.
The researchers believe that this new gene-editing technique could possibly cure obesity and other diseases.
CRISPR Vs. CRISPRa Technique
CRISPR differs from CRISPRa. CRISPR is a gene-editing technology that can be potentially used in cutting out genes that cause inherited diseases or disorders such as obesity.
Developed at UCSF in the lab of Jonathan Weissman, Ph.D., a professor of cellular and molecular pharmacology, CRISPRa, on the other hand, does not edit the DNA but rather ramps up the activities of a particular gene.
The researchers designed CRISPRa systems that targeted sequences which regulate the activity of SIM1 or MC4R, the genes that control food intake by sending a signal to the brain of being full. Mutations even in one of these genes are linked to extreme weight gain, the scientists said.
CRISPRa Tested On Mice With Genetic Mutations
Instead of using CRISPR to edit out the bad genes associated with obesity, USCF scientists modified the gene-editing tool. In a test, the new technique tweaked the activities of the genes of mice with a genetic mutation that makes them susceptible to gaining weight.
Throughout the study, the team studied two groups of genetically-engineered mice. One group received an injection of the CRISPRa treatment and the other group did not. Both groups were fed with a normal diet for 10 months.
Apparently, the untreated mice ate too much food and seemed hungry all the time that in just 10 weeks, they became extremely fat. The CRISPRa-treated mice were slim at 30 to 40 percent lighter compared to the untreated ones. The mice that received a single CRISPRa treatment were able to keep a healthy body weight during the 10-month period.
CRISPRa Shows Dramatic Results
The outcome showed a long-lasting weight control, which is a desirable and dramatic result without performing any single edit to the genome.
"The results were dramatic. Mice that were missing one copy of the SIM1 gene received the CRISPRa injections at four weeks of age and maintained a healthy body weight like normal mice," said Navneet Matharu, Ph.D., lead author of the study.
"Mice that didn't receive CRISPRa injections couldn't stop eating. They started gaining weight at six weeks of age, and by the time they were 10-weeks old, they were severely obese on a regular diet."
Matharu added that the results prove CRISPRa may not only help obese people who want to lose weight. It can also provide a potential cure for hundreds of other diseases.
The new study was published on Dec. 13 in the journal Science.