According to Einstein’s concept of relativity, time passes extra slowly in area. As a consequence, astronauts would expertise a delay in growing old. However, scientists discovered that area journey could have the alternative impact by accelerating aging in human cells, possible as a result of excessive physiological stresses it imposes on the physique.
“Space is the ultimate stress test for the human body,” stated Catriona Jamieson, a stem cell biologist on the University of California, San Diego, in a statement.
Recently, Jamieson’s staff found that spaceflight accelerates growing old in human blood-forming stem cells.1 The researchers discovered that stem cells that spent a couple of month in area had a lowered self-renewal capability and confirmed indicators of molecular growing old. Their outcomes, revealed in Cell Stem Cell, exhibit the attainable risks of spending prolonged time in area.
In 2015, NASA recruited twin astronauts Scott and Mark Kelly for an experiment to research the results of spaceflight stress on people.2 The researchers discovered vital variations in molecular profiles between Scott, who spent almost a 12 months in area, and his an identical twin Mark, who stayed on Earth. Some of the variations, akin to telomere shortening and indicators of DNA harm, continued till the endpoint of the examine, six months after Scott returned to Earth.
Catriona Jamieson, a stem cell biologist on the University of California, San Diego, investigates how area journey impacts cells within the human physique.
UC San Diego Health Sciences
Jamieson needed to research the results of spaceflight stress on cells in better molecular element by specializing in a selected cell kind. As a stem cell researcher, she selected to research this phenomenon in hematopoietic stem and progenitor cells (HSPCs), that are answerable for renewing blood and immune cells. For the current examine, Jamieson’s staff collected HSPCs from the bone marrow of people present process hip alternative surgical procedure. The staff cultured these cells for as much as 45 days both on the International Space Station (ISS) or in a analysis facility on Earth.
The researchers used a number of strategies to guage the cells’ growing old course of. First, they expressed a fluorescent gene reporter, which allowed them to tell apart cells in several phases of the cell cycle below the microscope in actual time. Using this technique, the staff discovered that in comparison with HSPCs that stayed on Earth, their counterparts in area had increased cell cycle exercise, indicated by elevated cell division and lowered dormancy—each of which counsel sooner growing old.
The staff additionally carried out extra experiments after the cells from ISS returned to Earth, together with whole-genome and RNA sequencing, to guage adjustments in telomere size, genomic stability, and gene expression patterns related to growing old. Like within the twin examine, the researchers noticed the same sample displaying a discount in telomere size in addition to considerably decrease gene expression related to telomere upkeep.
In addition to the adjustments related to growing old, Jamieson’s staff noticed the next prevalence of single-base mutations in stem cells that went to area, indicating genome instability. The researchers used a computational device referred to as AlphaMissense to foretell the probably deleterious results of this instability.3 The staff discovered that the stem cells that underwent spaceflight collected mutations related to clonal hematopoiesis, a situation the place a mutant blood cell proliferates and might contribute to the event of acute myeloid leukemia later in life.4 They didn’t establish such mutations in cells that by no means went to area.
In the longer term, Jamieson’s staff, in partnership with NASA, hopes to search out higher methods to watch molecular adjustments in astronauts in actual time and establish methods that might assist forestall or deal with the deleterious results of area journey. Jamieson believes that advances in area analysis will possible additionally profit people on Earth, noting that it “has accelerated technological advancements on Earth, making ground-based research easier and more relevant to human health.”