Exploring space is also confronting the human body with an environment radically different from that for which it has evolved. Up there, far beyond the earth's atmosphere, biological laws seem to be rewritten. Among the most disturbing discoveries, researchers are now wondering about the effects of an prolonged orbit stay on cellular longevity. Because the aging of the weightless stem cells is no longer a simple hypothesis, but from a measurable phenomenon with worrying consequences.
This permanent awakening is not without consequences. Researchers from the Sanford Stem Cell Institute have designed mini-bioreactors to embark cells from bone marrow in four spatial missions between 2021 and 2023. These cells presented an abnormally sustained activity, leading to premature aging, as explained by the Catriona Jamieson Biologist Cited by CNN Science.
Among the trigger factors, two major elements emerge. First, the prolonged absence of gravity seems to disturb the natural rest and cell renewal cycles. Then, the cosmic radiation, much more intense in low orbit, acts as chronic oxidative stress on cellular DNA. This double pressure pushes the cells to draw on their reserves, to deregulate themselves, and to activate normally silent areas of their genome.
The aging of weightless stem cells jeopardizes the immunity of astronauts
Hematopoietic cells, at the origin of white and red blood cells, are directly affected by these disruptions. Exhibited for several weeks in space, they show signs of accelerated senescence. According to a study published in the review Cell Stem Cell, these cells reduce their ability to maintain their telomeres, these DNA protective ends which naturally shorten with age. Cellular aging is also manifested by a fall in the expression of the Adar1 gene, involved in self -regional.
Another worrying phenomenon, the researchers observed a reactivation of the “dark genome”. These are DNA fragments inherited from ancient retroviruses, which have been inactive for millennia, but which can manifest themselves under extreme stress. Their activation was associated with genetic instability and a cell decline spiral which recalls certain pre-leukemic pathologies.
This table, drawn up after multi-ordinary analyzes combining complete sequencing, real-time monitoring and proliferation tests, suggests the risks of a weakening of the immune system during long space missions. A risk that is all the more tangible as certain mutations observed on the income from the space returned to those detected in the beginnings of blood cancers, according to the conclusions of the ISSCOR program of NASA.
Spatial biotechnologies to better understand age -related diseases
What space research today reveals about the aging of stem cells could soon light well terrestrial areas. The mechanisms observed in orbit have strange similarities with those identified in patients with hematological cancer or age -related immune disorders. Accelerated aging, spontaneous mutations and loss of regeneration capacity are all shared processes.
By exploiting the tools developed to study orbit cells, scientists could refine their understanding of degenerative diseases. Miniature bioreactors, capable of simulating extreme environments and monitoring live cell evolution, open the way to unpublished preclinical tests. They would predict how an organism reacts to chronic stress, whether cosmic or metabolic.
This convergence between spatial medicine and biomedical research suggests new models for studying aging. It could also inspire therapeutic countermeasures, both for astronauts and for patients on earth. The prospect of using stem cells as a predictive avatars, capable of indicating in advance the risks of exposure or the effectiveness of a treatment, is gradually imposed as a logical extension of this work.
By rejecting the limits of human biology beyond our planet, space research does not only prepare the future of missions to Mars. It also redesign the contours of tomorrow's medicine, highlighting the invisible weaknesses of our own aging.
