In the microgravity environment on board the International Space Station (ISS), astronauts are known to suffer from a host of ailments, some requiring mitigation. Chief among these are bone density and muscle loss, which require astronauts to follow a strict daily exercise regimen for their duration on the ISS. However, recent studies have indicated other, less obvious conditions that can also be attributed to the space environment.

One of these conditions is space anaemia, a mild form of anaemia that sees a drop in astronaut red blood cell counts within a few days of arriving in space. Just a few weeks after return from the ISS, the space anaemia condition is, however, fully resolved, with astronauts recovering completely without any necessary intervention.

Anaemia on Earth, especially in its more severe forms, is an extremely debilitating disease, with patients possibly requiring frequent blood transfusions and other intrusive treatment procedures, such as bone marrow transplants. 

In our study, recently published on Nature Communications as part of the Space Omics and Medical Atlas (SOMA) Nature collection, we investigated blood samples obtained from astronauts from a number of different missions and space agencies, namely NASA, JAXA and the Space X Inspiration4 mission.

The aim of the study was to ascertain, at the RNA level, which genes changed in their expression before, during and after spaceflight

The aim of the study was to ascertain, at the RNA level, which genes changed in their expression before, during and after spaceflight. A globin gene switch mechanism, previously suspected to play a role in amelioration of symptoms in severely anaemic patients on Earth, was also seen to be activated in astronauts.

This globin gene switch mechanism sees a ‘reversal’ in expressed globin, with an increased expression of foetal haemoglobin, typically only expressed at higher levels before birth and during the first few months post-partum, and a simultaneous lowering of adult haemoglobin expression.

The clinical significance of this trend is that foetal haemoglobin has a higher oxygen affinity, and understanding the pathways leading to its enhanced expression could provide a treatment route for chronic anaemia patients. In addition, changes in a number of genes involved in red blood cell production were seen after return to Earth, once again providing clues as to the pathways through which astronauts were able to recover from space anaemia.

While this is one of the first studies looking at space anaemia in such detail, we aim to further investigate this condition to be able to further understand the globin switch mechanism, in itself a probable adaptation to the space anaemia condition, with future astronaut missions to the ISS and beyond! 

Josef Borg completed a PhD in astronomy at the Institute of Space Sciences and Astronomy, University of Malta, and is currently a post-doctoral researcher in space bioscience at the Faculty of Health Sciences at the University of Malta.  Joseph Borg is an academic and full professor at the Department of Applied Biomedical Science, Faculty of Health Sciences at the University of Malta, specialising in haemoglobin biology, genetics and space bioscience.

Sound Bites

The Space Omics and Medical Atlas Nature package: A collection of over 40 papers were released in the Space Omics and Medical Atlas Nature package, with different studies looking into various different effects of spaceflight on human physiology. This represented the work carried out by scientists in 25 countries, hailing from over 100 different institutions. Maltese researchers were involved in five of these publications.

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DID YOU KNOW?

•        Space travel poses significant challenges to human physiology, particularly concerning blood health and anaemia: The phenomenon of space anaemia occurs in part due to the body’s adaptation to the weightless environment, resulting in the destruction of red blood cells and a reduction in their production. Upon returning to Earth, recovery from space anaemia can take several weeks. Continuous research is crucial to ensure the health and safety of astronauts on long-duration missions.

•        Life science research in space is critical for understanding how microgravity affects human physiology and health: The International Space Station (ISS) serves as a unique laboratory where scientists conduct experiments that cannot be performed on Earth. Studies on the ISS have revealed that microgravity affects various bodily systems, including muscle atrophy, bone density loss and cardiovascular changes. Additionally, research on the ISS has shown alterations in immune system function and microbial behaviour, providing insights into potential health risks.

For more trivia, see: www.um.edu.mt/think.