CRISPR Technology
CRISPR/Cas9 technology is a molecular tool used to "edit" or "correct" the genome of any cell. This includes, of course, human cells. It would be something like molecular scissors that are capable of cutting any DNA molecule and doing so in a very precise and totally controlled manner. This ability to cut DNA is what makes it possible to modify its sequence, eliminating or inserting new DNA.
The acronym CRISPR/Cas9 stands for Clustered Regularly Interspaced Short Palindromic Repeats. The latter is the name of a series of proteins, mainly nucleases.
Several studies have been conducted using this technology, with promising results. In one of them, scientists from several countries correct a hereditary disease in human embryos. The CRISPR technique eliminates the genetic cause of sudden death.
Scientists in the USA, South Korea, and China have successfully eliminated an inherited disease in human embryos for the first time. The research is a major step toward future therapies to correct certain types of cancer as well as some 10,000 rare diseases that arise when one of the two copies of a gene is wrong.
It is also a wake-up call to society as a whole, as the technique allows humans to change their biological destiny by introducing changes in germ cells - eggs, sperm, and embryos - that will be passed on forever from generation to generation.
The researchers have focused on hypertrophic cardiomyopathy, a common heart condition that causes sudden death in athletes and young people. Scientists have used CRISPR to correct the mutation in the sperm of a man who is a carrier of the disease. The scientists injected the sperm and a CRISPR sequence with the correct gene version into eggs donated by healthy women at the same time.
Of the 58 resulting embryos, 42 developed without the disease-causing mutation, a success rate of 72%.
Other studies seek to use this technology to treat progeria syndrome. One study concluded that a Single-Dose CRISPR/Cas9 Therapy Extends the Lifespan of Mice with Hutchinson-Gilford Progeria Syndrome.
Hutchinson-Gilford syndrome (HGPS), also known as infantile progeria, is a rare genetic disease characterized by premature aging that begins early in childhood. This is a rare, incurable, and fatal genetic disease characterized by abrupt and premature aging in both boys and girls, regardless of race, resulting in children with the appearance of the elderly.
"Aging is a complex process in which cells start to lose their functionality, so it is critical for us to find effective ways to study the molecular drivers of aging," says Juan Carlos Izpisua Belmonte, senior author of the paper. "Progeria is an ideal aging model because it allows us to devise an intervention, refine it and test it again quickly.”
The researchers used the CRISPR/Cas9 system to deliver gene therapy into cells of a Cas9-expressing mouse model of progeria.
Two months after treatment, the mice were stronger, more active, and had improved cardiovascular fitness. They showed reduced degeneration of large arterial vessels and delayed onset of bradycardia (an abnormally slow heart rate) -- two problems common in progeria and aging. Overall, the treated progeria mice had activity levels similar to normal mice, and their lifespans increased by about 25 percent.
Taken together, the results demonstrate this can significantly improve the physiological health and longevity of mice with progeria. These results provide an important new understanding of how scientists can ultimately target the molecular drivers of human aging.