Recently, scientists have shown that slowing the effects of aging with “young” blood is not just myth and pop culture. Indeed, studies have in the past revealed that the transfusion of young blood in elderly people slows down cellular senescence, improves cognitive abilities and delays the onset of age-related diseases. However, the benefits of transfusion are only temporary. Seeking to transpose these effects over the long term, researchers from Columbia (in New York) have suggested that a drug against rheumatoid arthritis could rejuvenate the blood production system (or hematopoietic system). Acting directly on blood stem cells by blocking an inflammatory cytokine, the drug would allow the production of young blood, without the need for transfusion. Although the research is still preliminary, the researchers hope to quickly move into clinical trials, with the drug already on the market.
Aging being a risk factor for many pathologies, more and more studies are looking at ways to reverse or slow down the process. Recent studies on aging have demonstrated that by injecting blood from young mice into older mice, the latter temporarily acquire the same physiological capacities as young mice. The opposite effect can also occur when blood from old mice is transfused into young mice, suggesting that aging is a relatively malleable state.
Apart from the transfusion of young blood, other tests have been carried out, such as the dilution of aged plasma, in order to eliminate factors or markers of senescence. However, the effects were only temporary and were only enough to alleviate the classic symptoms of aging, such as loss of muscle and heart tone. As part of a previous studyresearchers in the new study attempted approaches that directly targeted blood stem cells.
Remember that our blood cells (red blood cells, immune cells, platelets, etc.) are produced from a small number of stem cells residing in the bone marrow. With age, these so-called hematopoietic stem cells produce fewer red blood cells, fewer immune cells and struggle to maintain their genetic integrity (increasing the risk of blood cancer).
In an attempt to reverse the aging effects of hematopoietic stem cells, the Columbia research team observed (in a previous study) the effects of exercise and low-calorie diets on mice (alternatives generally thought to be may slow aging). But no significant change was noted.
Attempts to implant young stem cells and the transfusion of young blood have also failed to rejuvenate aged blood stem cells. The researchers then assumed that the best way to obtain the benefits of young blood in the long term would be to rejuvenate its production system upstream.
The changing conditions (with age) of the hematopoietic milieu are in theory a large part of the problem of aging. “ An aging blood system, because it is a vector of many proteins, cytokines and cells, has many harmful consequences for the organism. », explain Emmanuelle Passegué, a researcher in the Department of Genetics and Development at Columbia and co-lead author of the new study. ” A 70-year-old with a 40-year-old blood system could have a longer lifespan “, she suggests.
Blocking an inflammatory cytokine
According to the new study, described in the journal Nature Cell Biology, the hematopoietic milieu inside the bone marrow would deteriorate as one ages. From the age of fifty, we know that bone tissue is gradually degraded. In this condition, this very specific environment is overwhelmed with inflammatory molecules, which lead downstream to blood stem cell dysfunction.
The inflammation observed in the hematopoietic system is thought to be induced by interleukin-1B (IL-1B), the production of which can be inhibited by anakinra-type drugs, commonly prescribed against rheumatoid arthritis. When given to mice, the drug had significant blood stem cell rejuvenation effects, especially when given over the animals’ lifetimes — not just when they had already reached old age.
Now the question is whether the drug can have the same rejuvenating effect on humans. “ Treating elderly patients with anti-inflammatories that block IL-1B function should help maintain healthier blood production “says Passegué. As anakinra is already on the market, the research team expects to move quickly to clinical trials. Moreover, through the circulatory system, the rejuvenating effect could probably extend to the whole organism.
However, keep in mind that it is not recommended to take anti-inflammatories for too long, at the risk of causing side effects on the liver or other organs. Researchers will therefore have to focus more on the safety of the drug.
