Do you think stem cells floating in space could possibly help us down on Earth? This might sound far out, but scientists are finding that researching stem cells outside our planet could help us better understand the physiological changes to astronauts in orbit and, more broadly, provide key insights about disease progression and treatment on Earth.

When stem cells are out of this world

Space travel plucks us away from the pull of Earth’s gravity and exposes us to solar radiation – novel conditions that provide new opportunities for research. While it is impractical to send a whole team of biologists to space, extraterrestrial physiology can still be studied by preparing cells on Earth, sending them to the International Space Station (ISS) and monitoring them remotely using automated experimental systems such as Space Tango’s CubeLab and NASA’s Bioculture System.

With these technologies, scientists sent human stem cell-derived heart cells to space for the first time in 2016 (see Figure 1). Dr. Joseph Wu, Stanford University, USA, found that these beating cells behaved differently in microgravity, yet returned to normal once back on earth. This study revealed the remarkable adaptability of human heart cells to changing environmental conditions, setting the stage for future experiments.

To take innovative stem cell research like Dr. Wu’s to the next level, NASA is constructing the Integrated Space Stem Cell Orbital Research (ISSCOR), a dedicated state-of-the-art stem cell lab within the ISS whose mission is to apply the power of stem cells in space to improve quality of life on Earth.

Figure 1. NASA Astronaut Kate Rubins works to set up a new microscope onboard the space station for the Effects of Microgravity on Stem Cell-Derived Heart Cells investigation. MEDIA CREDIT: Image courtesy of NASA TV.

Cancer research with cosmic radiation

Dr. Catriona Jamieson, University of California, San Diego, USA, is one of the scientists utilizing ISSCOR to improve treatments for patients on earth. Solar radiation breaks and mutates our DNA, leading to cancer. Tissue stem cells, long-lived cells that replenish specific tissues, are particularly vulnerable to this accumulation of DNA damage. For instance, blood stem cells exposed to cosmic levels of radiation transition more rapidly to a precancerous state, allowing scientists to study disease progression at an accelerated pace compared to that on Earth. In addition, being in space causes the immune cells in contact with cancer cells to malfunction. By studying early onset blood cancers and immune reactivation syndromes in space, Dr. Jamieson is hoping to rapidly identify treatments that can be translated to clinical trials.

Experimenting with zero gravity

Microgravity has long been known to have detrimental effects on astronauts’ bodies, and recent research is finding stem cells may be the culprits. For example, astronauts who spend extended time in space often contract a condition known as space anemia, which is caused in part by the decreased production of red blood cells, our body’s transporters of oxygen and nutrients, which come from blood stem cells.

The absence of gravitational force can change the physiology of many other cell types, and Dr. Valentina Fossati, New York Stem Cell Foundation, USA, is taking advantage of this to try to find treatments for diseases such as Parkinson’s disease and multiple sclerosis. Microgravity can influence immune cell function and their interactions with neurons, while also mimicking aging in stem cells, allowing for novel investigations. Dr. Fossati is therefore launching stem cell-derived brain organoids, 3D models of the brain, into space in the hopes of unlocking the secrets to fighting age-related neurodegenerative disorders.

Regenerative medicine of the future?

Scientists hope to one day be able to use stem cells as a reliable source of healthy functional cells that can be transplanted into patients to treat a variety of conditions. For such transplantation therapy to be successful, billions and billions of cells may be required, which can be difficult to achieve in the laboratory. Unprecedently, multiple studies have shown that various stem cells actually grow better in space than in their usual earthly conditions. Stem cells grown in space may also be better at integrating into the appropriate tissue upon transplantation, as microgravity triggers favorable changes in cellular architecture. By studying the mechanisms behind these phenomena, researchers may find ways to promote stem cell expansion and tissue integration to improve stem cell therapy.

Stem cells in space are being studied in pursuit of developing therapeutics for diseases from cancer and aging to neurodegenerative and heart diseases. Thus, learning more about stem cells in space is not only significant for understanding the impact of extraterrestrial travel on the body but can also make significant contributions to terrestrial human health.

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Blog by guest contributor Kevin Gonzales, PhD, postdoctoral fellow in the lab of Elaine Fuchs at The Rockefeller University, NY, USA. To learn more register for our Digital Series “Stem Cells in Space.”