Lifespan-doubling injection in mice takes rejuvenation therapy step closer in humans

Scientists have developed a new injection that they claim can double the remaining lifespan of elderly mice, a breakthrough they say could help develop new treatments to reverse age-associated diseases.

Previous studies have shown that ageing is best characterised by the chronic dysregulation of gene activity in the body over time, leading to tissue and organ dysfunction. This deterioration has been shown to cause age-related functional decline and diseases.

In a new study, which is yet to be peer reviewed but has been published in the bioRxiv preprint server, scientists have said that a special injection can partially reprogram cells in mice to reverse age-related changes.

Researchers, including Noah Davidsohn from the biotech company Rejuvenate Bio, claim in the new study that the injection could double the remaining lifespan of geriatric mice.

“The main causes of death in the elderly are age-related diseases, such as heart disease, stroke, and specific cancers,” Dr Davidsohn said. “While ageing cannot currently be prevented, its impact on life and healthspan can potentially be minimized by interventions that aim to return gene expression networks to optimal function.”

The technique developed by scientists involves the control of a set of genes that have been shown to reverse age-related changes in lab cell studies.

Controlling the activity of this subset of gene factors – OCT4, SOX2, and KLF4; OSK – have been found to revert highly specified cells like a skin cell back to its younger and more adaptable stem cell state.

Japanese researchers discovered that they could essentially reset the clock on cells’ age by controlling these Yamanaka factors.

An earlier study had also shown that a subset of the factors could reverse damage to the optic nerve.

In the new research, scientists developed a system using a modified virus to deliver and express one of the Yamahaka factors OSK in 124 week old mice – the mouse equivalent of 77-year-old people.

They claim in the study that the treatment could enhance health parameters as well as increase remaining lifespan by 109 per cent in the rodents compared to control mice.

Scientists say the rodents that received the treatment lived for a median of 18.5 more weeks, while the untreated ones lived only for a median of 9 more weeks.

Researchers also reported gene activity changes in the mice that received the treatment which was consistent with age reversal of liver and heart tissue function relative to untreated controls.

While the rodent study does not directly translate to results in people, the findings, according to the researchers, suggest that partial reprogramming of cells could be a potential approach for reversing age-associated diseases in the elderly and “could extend human lifespan.”

“Together, these results may have important implications for the development of partial reprogramming interventions to reverse age-associated diseases in the elderly,” scientists wrote in the study.

“This is a powerful technology, and here is the proof of concept. I wanted to show that it’s actually something we can do in our elderly population,” Dr Davidsohn told MIT Technology Review.