Scientists have managed to reverse aging in mice by reprogramming cells to make them younger. This is the first time to having been successfully done in living organisms.

Courtesy: Juan Carlos Izpisua Belmonte Lab/Salk Institute

In the movie ‘The Curious Case of Benjamin Button’, Brad Pitt plays a character who becomes younger and younger – and this is actually not far from what a team scientists have managed to do with mice. As they have managed to, not only, halt the aging process, but even make the mice cells younger.

The team of researchers managed amazing feat by genetic tampering with the mice cells. Reversing the age of the cells by returning them to an earlier stage already passed.

This resulted in a longer lifespan of the mice, with an increase of between 18 and 24 weeks, which translates to about 30% longer lifespan.

These particular mice suffered from the aging disease called ‘progeria’, which causes cells to break down and die very quickly. By reprogramming how the cells behave, they were able to make them “back off” from this hastened aging process.

They used a method developed by the Nobel laureate in medicine Shinya Yamanaka, which enables the researchers to roll back time for live mice through systemic cellular reprogramming, causing them to become stem cells again.

All stem cells that can become any cell, they are in a state before embarking on a path and become, for example, a skin cell or a brain cell.

The method of reversing cells into stem cells involves inserting four specific so-called transcription factors in the genome. Simplified, a transcription factor that is a kind of code that is necessary for a gene to be able to begin the process of making proteins.

The researchers introduced these transcription factors into the mice’s genetic makeup. Treating the mouse with a kind of sterile hormone, these factors are activated and the cells begin to rewind the tape.

Induction of reprogramming improved muscle regeneration in aged mice. (Left) impaired muscle repair in aged mice; (right) improved muscle regeneration in aged mice subjected to reprogramming. Credit Salk Institute

This method has been used in a test tube previously, but the researchers were then forced to wait two or three weeks before the cells have fully become stem cells again.

In this case, however, the cells were given four to five days only and this is not enough time for them to revert back to being stem cells again, but it was enough time for them to be reprogrammed and to trip away some elapsed to time from their age, to become healthy, young cells, again.

“We were surprised and excited to see that we were able to prolong the lifespan by in vivo reprogramming,” says co-first author Pradeep Reddy.

Tissue from skin, spleen, kidney and stomach all had improved appearance when inspected under a microscope. And the cardiovascular system, which is especially exposed to different risks and is often the cause of early death in these prematurely aging mice, also showed improvements in structure and function.

“It is difficult to say specifically why the animal lives longer,” says co-first author Paloma Martinez-Redondo. “But we know that the expression of these factors is inducing changes in the epigenome, and those are leading to benefits at the cellular and organismal level.”

It will probably take some time before this method or something similar, can be safely used on people, there may be many ethical issues to consider, and much more research on the medical safety needs to be done for it to be medically validated.


Alejandro Ocampo et al. In Vivo amelioration of Age-Associated Halllmarks by the Partial Reprogramming. Cell, 2016. DOI: 10.1016 / j.cell.2016.11.052