Scientists Unravel Mystery of Aging: Gene Length Is the Decisive Factor

Scientists think they have cracked the secret of aging.

Major genetic analysis of people, rodents and fish has revealed that the length of their DNA is directly related to their biological age.

Shorter genes were associated with shorter lifespans, while longer genes were linked to better health and longevity.

Scientists believe that if they can hijack this mechanism, it could pave the way for a fountain of youth drugs that could slow — or even reverse — aging.

Dr Thomas Stoeger, lead author of the study from Northwestern University in Illinois, said: ‘I find it very elegant that a single, relatively concise principle seems to explain almost all of the changes in gene activity that occur. occur in animals as they age.’

The length of a gene is based on the number of nucleotides it contains. Each chain of nucleotides translates into an amino acid, forming a protein.

Therefore, a very long gene results in a large protein and a short gene results in a small protein. A cell must have a balanced number of small and large proteins to achieve homeostasis, and problems arise when this balance is out of whack.

In the study, the researchers looked at genetic data from several large datasets, including the Genotype-Tissue Expression Project, a tissue bank funded by the National Institutes of Health that archives samples from human donors for the purpose of research.

The research team first analyzed tissue samples from mice, rats and killifish of various ages.

In all the animals, the researchers noticed subtle changes in thousands of different genes across the samples.

This means that it’s not just a small subset of genes that contribute to aging. Aging, on the contrary, is characterized by changes at the systems level.

This view differs from mainstream biological approaches that study the effects of single genes.

Since the advent of modern genetics in the early 20th century, many researchers expected to be able to attribute many complex biological phenomena to single genes.

And although some diseases, such as hemophilia, result from mutations in a single gene, the narrow approach to studying single genes has yet to lead to explanations for the myriad changes that occur in neurodegenerative diseases and aging.

After completing their animal research, the researchers turned to humans. They looked at changes in human genes from ages 30 to 49, 50 to 69, and then 70+.

Measurable changes in gene activity as a function of gene length have already occurred by the time humans reach middle age.

“It already seems like something is going on early in life, but it becomes more pronounced with age,” Dr. Stoeger said.

“It seems that, from an early age, our cells are able to counter disturbances that would lead to an imbalance in gene activity. Then, suddenly, our cells can no longer counter it.

Luis Amaral of Northwestern, lead author of the study, said: “The result for humans is very strong because we have more samples for humans than for other animals.”

“It was also interesting because all the mice we studied are genetically identical, of the same sex and raised in the same laboratory conditions, but humans are all different.

“They all died of different causes and at different ages. We analyzed male and female samples separately and found the same pattern.

But scientists have found that as we age, activity within cells shifts to shorter genes, upsetting the balance.

This is counterbalanced in people with very long genes, as they have longer proteins available in cells.

Dr Stoeger said: ‘Changes in gene activity are very, very small, and those small changes involve thousands of genes.

“We found that this change was consistent across different tissues and across different animals.”

Scientists hope the study – published in Nature Aging – will spur the development of therapies to slow or reverse aging.

Currently, drugs target the symptoms rather than the causes of aging, which North West experts say is like using painkillers to reduce fever.

Dr Amaral said: “Fevers can occur for very many reasons. It can be caused by an infection, which requires antibiotics to cure, or caused by appendicitis, which requires surgery.

” Here, it’s the same thing. The problem is the imbalance of gene activity. If you can help correct the imbalance, then you can deal with the downstream consequences.