Age Reversal and What It Means For Us

Aging is an irreversible pathophysiological process. Aging plagues all humans and leads to higher chances of debility, disease, and death. Hence, this begs the question: What causes aging?

In the past, the prevailing theory for the cause of aging was the accumulation of genetic mutations over time that affect the proper functioning of tissues and organs. However, research on mice with high mutation rates with no signs of premature aging and aged cells with low mutation rates have led to the emergence of other theories.

Dr. David Sinclair, a professor at Harvard Medical School, suggests that aging is the result of losing critical instructions for cell functioning. All cells have the same epigenome, a DNA blueprint, which regulates tissue differentiation.

He believes the cure for aging lies in resetting the epigenetic instructions of cells. Hence, together with his team of scientists, he has experimented with gene therapy on Yamanaka stem cell factors. The stem cells were discovered by Nobel scientist Shinya Yamanaka in 2006 and were chosen specifically because they allow adult cells to turn back to their stem cell state, reboot, and restart the differentiation process. “It’s like rebooting a malfunctioning computer,” said Sinclair.

A correlation has also been found between aging and shortened telomeres. Telomeres, which are protective caps found at the ends of our chromosomes, are formed by telomeric DNA and binding proteins. They shorten each time the cell divides due to the uneven replication of leading and lagging strands during DNA replication. Once telomeres shorten to a critical length, the cell enters a senescent phase and is said to have reached the Hayflick limit. The cell will ultimately stop dividing or undergo apoptosis (programmed cell death).

In cancer cells, scientists studied the effect of the enzyme telomerase. It was shown to prevent telomere shortening and allow cells to replicate indefinitely. To combat aging, scientists have considered using telomerase to stop or reverse the erosion of telomeres. At the same time, it has been found that forcing cells to have longer telomeres can lead to cancer, and hence, scientists have become wary of telomerase-related antiaging therapies.

Although telomerase may increase telomere length for some cells, it may not be as helpful for cells that seldom replicate such as those in the brain. Neurodegeneration is an age-related disease that has been and will continue to be a pressing issue for America’s aging population. Alzheimer’s disease is a type of dementia that affects millions of Americans and yet has no cure. Currently, scientists aim to use specific chemical compounds in drugs to target neurodegenerative diseases like Alzheimer’s to improve the human quality of life. Compounds such as fisetin (found in fruits and vegetables) and curcumin (from turmeric) have shown promise.

The impact that regenerative medicine has on the scientific community and the society is great. Scientists anticipate it to be useful in managing diabetes, muscular dystrophy, and the shortage of transplant organs available. Ultimately, through regenerative medicine, the scientific world would be able to address the root causes of aging instead of mitigating damages from age-related diseases, which might already be too late.

On the future of age reversal, Dr. David Sinclair said: “It’s no longer a question if rejuvenation is possible, but a question of when.”