But the rodent is in for a surprise. Researchers give it an age-reversal cocktail, and before long, the mouse is active, energetic and full of life.
If you're thinking this is too good to be true, that there must be a catch, you’re right...
A few days later the mouse is dead.
Oops!
But even in the face of this setback, scientists believe the technology that gave this mouse a new lease on life—at least temporarily— will be developed and safely applied to humans someday, allowing us to live much longer lives. Let’s take a look...
The age-reversal cocktail used in the mouse study sounds a lot like the fountain of youth.
"It completely rejuvenates," explained Juan Carlos Izpisúa Belmonte from the Gene Expression Laboratory at the Salk Institute for Biological Studies in San Diego.
Dr. Izpisúa Belmonte reported that the age-reversal cocktail restored all of the cells and organs in the once dying mouse to their youthful state.
How?
Through a tool called epigenetic reprogramming, which resets the body's epigenetic marks that control which genes are turned on and off within cells.
Epigenetic Reprogramming and Stem Cells
Dr. Izpisúa Belmonte’s work is based on a discovery made in 2006, which found that adding four proteins to human adult cells wipes out the epigenetic marks. If the marks are erased completely, the cell no longer knows what type of cell it is and reverts back to an embryonic state, giving the cell a fresh start.These “embryonic” cells are called induced pluripotent stem cells (IPSCs) and can be turned into any other type of cell in the body. Even skin cells from centenarians can revert to an embryonic state when scientists apply epigenetic reprogramming. This technique isn’t brand new -- in fact, it’s often used by labs to manufacture stem cells.
This reprogramming has also been demonstrated, not just in a Petri dish, but inside other laboratory mice. Some have lived and some have died.
Why Did the Rejuvenated Mouse Die?
The problem is that when you clear away the marks, the cell loses any identity or memory. While it might then grow into a functioning cell, it could just as easily remain dormant or become cancerous. The results are usually fatal. In the case of the lab mouse at the beginning of our article, it sprouted tumors.However, the good news is that the scientists at the Gene Expression Lab have devised a way to temper the process. The cells of mice with progeria can be partially reprogrammed to not only reverse aging, but live longer.
Mice Live 30 Percent Longer
In their experiment using this new technique, mice gained strength, various organs saw functional improvement and no tumors formed. They also lived 30 percent longer."That was the benefit," said Dr. Izpisúa Belmonte. "We don’t kill the mouse. We don’t generate tumors, but we have our rejuvenation."
Solving the Root Cause of Aging
Dr. Izpisúa Belmonte believes this epigenetic reprogramming will extend human life span by 30 to 50 years, because aging as he describes it is "nothing other than molecular aberrations that occur at the cellular level.”He points out how these aberrations come partly from changes that occur over time to the epigenetic marks. These changes cause cells to malfunction, leading the body to suffer the symptoms and illnesses of aging. Epigenetic reprogramming can reverse these alterations and successfully delay aging.
Many Unanswered Questions
While some scientists are positive about Dr. Izpisúa Belmonte’s findings, others are more cautious, pointing to a number of difficulties.For one thing, a vast number of processes are involved in aging and it's unlikely just one would be so powerful as to override all the others. It's possible, but this hasn't been demonstrated yet.
It's also possible that epigenetic changes are merely signs of aging, not a major cause. Treatments may be no more than cosmetic, the equivalent of smoothing out wrinkles.
Mice with progeria are used in experiments because they only live three months, but progeria involves a single DNA mutation. Natural aging is far more complex. It isn't known whether the technique will work in normal, healthy mice.
Although there are still many unanswered questions, Dr. Izpisúa Belmonte remains optimistic.
"I think the kid that will be living to 130 is already with us. He has already been born. I’m convinced."
