[LUM#4] Growing old: the big deal

[LUM Magazine] - Published on January 17, 2017 in Science-Society

Living longer and in good health? It's possible! We still don't know how to stop the effects of time, but researchers now know how to delay them.

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At the age of 100, she was still riding a bicycle. She lived at home until she was 110, and died at the canonical age of 122 years, 5 months and 14 days. And what if we all soon learned about Jeanne Calment's exceptional longevity? " Not only her longevity, but also her vitality," replies Jean-Marc Lemaître. The researcher at theInstitute for Regenerative Medicine and Biotherapy(IRMB) is convinced: we're going to live longer and healthier. For a very long time, research focused mainly on age-related diseases, without seeking to understand ageing itself, its causes and consequences", explains the specialist. Now, the scientific community has come to realize that by treating aging, we will also be treating the pathologies associated with it."

Understanding aging

And over the past 15 years, the fight against aging has taken a quantum leap forward, thanks in particular to research into "senescent" cells. " When subjected to stress, cells can enter senescence, a state in which they no longer proliferate but don't die either ," explains Jean-Marc Lemaître. The problem is that these cells secrete substances that cause chronic inflammation, often associated with age-related illnesses. " In a young person, senescent cells are suppressed by the immune system, but from the age of 50, this process loses its effectiveness, and senescent cells accumulate in the body, with all their negative effects ".

What if, to slow down the aging process, we were to attack these famous cells? That's what American researchers at the Mayo Clinic in Minnesota have done: they have succeeded in suppressing senescent cells in mice. The result: the rodents' life expectancy was extended by 30%. " Not only did these mice live much longer, they also aged better," emphasizes the aging specialist. Mice treated in this way showed fewer age-related pathologies such as cataracts and muscle wasting.

Anti-aging pill

Good news for mice, but what about humans? " We can imagine transposing these results to humans," replies the specialist. 30% more longevity? We could all live to be centenarians. And in good shape, too: " Eliminating senescent cells can extend the number of years we live in good health ," insists Jean-Marc Lemaître. What was considered science fiction until recently will soon become reality. " We have already identified molecules such as rapamycin, an immunosuppressant, or metformin, a substance used to treat diabetes, which delay senescence in humans and are good candidates for an anti-aging cocktail. We still need to find small molecules that will selectively destroy senescent cells". When will we see the arrival of a "long life in good health" pill?" Within the next fifteen years ", assures Jean-Marc Lemaître.

In parallel with work on senescent cells, research into regenerative medicine is making great strides. " The idea is to be able to repair tissues and organs damaged by aging or disease," explains Jean-Marc Lemaître. How can this be achieved? By replacing failing cells with healthy ones. With cell therapy, researchers can create cells à la carte. " We reprogram simple cells such as blood cells into stem cells ", explains the reprogramming specialist. This "reset" then enables these cells to be differentiated into the body's various cell types: hepatic, to regenerate the liver; cardiac, to repair the heart. " By treating age-related diseases in this way, we can significantly increase life expectancy in good health," says Jean-Marc Lemaître.

Longevity without limits?

Regenerative medicine is not just about curing disease, it's also about creating human "bio-organisms" to replace a tired pancreas or a worn-out kidney. "The first bio-artificial kidney should appear within the next 5 to 10 years," says the specialist.

Slowing down the aging process, swapping outdated cells for fresh ones, replacing our failing organs with brand-new machinery... the fountain of youth could be just a test tube away. " If these scientific advances are accompanied by a genuine social will, everyone could live to be 120 years old in good health ," imagines Jean-Marc Lemaître. And why not even longer? A thorny question for researchers. " In fact, we don't really know what the limit of longevity might be "...