The human heart shows signs of aging after a month in space
The human heart shows signs of aging after a month in space
In the course of only one month in space, the constructed heart tissue of humans became weaker, his "blow" pattern became irregular, and molecular and genetic changes occurred that imitated the effects of aging. Reference "Data Track Category =" References "> 1 The results were published today in the Proceedings of the National Academy of Sciences.
The study offers a useful method for identifying the molecular paths that are responsible for the harmful effects of space flight on the human heart, says Joseph Wu, cardiologist at Stanford University in California.
Microgravity can harm the body, and astronauts that are exposed to it have experienced cardiovascular changes such as irregular heartbeats. The understanding of the effects of long-term missions in space-which can last for several months-and the molecular changes on which these changes are based remained out of reach, explains the co-author of the study, deok-Ho Kim, a biomedical engineer at the Johns Hopkins University in Baltimore, Maryland. "It is not possible to carry out the various molecular and functional studies on human astronauts," he says.
a 'heart' on a chip
To master this challenge, Kim and his colleagues sent heart fabric for 30 days for International Space Station .
To develop the tissue, the researchers brought human induced pluripotent stem cells that act as empty canvases and in every cell type differentiate to this to develop into human heart muscle cells. The team tensioned sets of six tissue patterns between couples from stands. A post in every couple was flexible, so that the patterns could contract like a beating heart. The system that you call a heart-on-one chip was housed in a housing that was about half the size of a mobile phone.
As soon as the heart-on-one chip system was on board the ISS, Kim and his colleagues used sensors to monitor the strength of the contraction and the impact patterns of the tissue in real time. For comparison, monitor another set of tissue patterns that remained on earth.
After 12 days on the ISS, the contraction strength of the tissue had almost taken away by half, while the soil pattern remained relatively stable. This weakening was still obvious even after nine days of relaxation on earth. In space, the tissue's blows also became more irregular over time, with the interval between each blow on the 19th day by more than five times. However, this irregularity disappeared after the patterns returned to earth. This indicates that the NASA astronauts Sunita Williams and Butch Wilmore-who have been on the ISS for months due to technical problems with the Boeing Starliner spaceship-probably experienced cardiovascular stress, which is probably back on the ground, says Wu.
genetic changes
After the tissues have returned from space, Kim and his colleagues used the transmission electron microscopy to look at the sarcomers of the patterns - protein strands that are responsible for muscle contractions. After a month in orbit, these protein bundle had become shorter and more messy compared to those that remained on the floor. The mitochondria - the energy -producing machines in cells - were also swollen and fragmented.
When the researchers sequenced the RNA of the tissue pattern, they put an increase in the Expression of genes and signal paths, which are connected to inflammation and heart diseases in the tissues. At the same time, genes showed for proteins that are necessary for normal heart contraction and mitochondria function, signs of reduced expression.
Although the approach of the heart-on-one chip is innovative, he does not capture other important cardiovascular changes that can occur in the human heart, such as pressure in the arteries, says WU. However, it adds that a similar facility could be useful to examine how other organs react under microgravity and extreme radiation levels. "The ability of this platform to function in a microgravity and at the same time maintain tissue viaability is a great advantage," he says.
KIM and his colleagues plan to send further heart and organ tissue into space for a long time in order to examine the effects of space flight. They also hope to test medication that can counteract some of the effects of microgravity on the heart.
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Mair, D. B. et al. Proc. Natl acad. Sci. USA 121, E2404644121 (2024).