In the complex laboratory space of the International Space Station, the study of life at the subcellular level is opening a new chapter of science that connects space travel and biomedical challenges on Earth. Research on cells in microgravity provides key insights – from understanding the mechanisms of cellular gravity perception to applications in treating diseases like osteoporosis, muscle atrophy, cardiovascular disorders, and neurological degenerations.

Cells – the foundation of life in space

Cells are the basic units of life, present in all living beings, from single-celled bacteria to complex organisms like humans and plants. Each cell has a unique structure and function: while nerve cells use long fibers to transmit signals, plant cells have rigid cell walls that provide them with mechanical support. In microgravity conditions, these basic functions can change significantly, opening up space for new scientific discoveries.

Cell Gravisensing – discovering how cells "feel" gravity

One of the most intriguing questions in space biology is how cells register the presence or absence of gravity. The Japanese space agency JAXA is conducting an experiment called Cell Gravisensing, which focuses on the molecular mechanisms of gravity perception. Research shows that changes in the tension of cellular fibers can affect signaling pathways, activate ion channels, and trigger a series of reactions within the cell. For this purpose, advanced methods of confocal microscopy and FRET technology are used to measure changes at the protein and intracellular structure levels. The results could pave the way for the development of new therapies against bone mass loss and muscle atrophy, both for astronauts on long-term missions and for patients on Earth.

Cardiovascular changes – STaARS BioScience-3

The STaARS BioScience-3 mission investigated changes in the cells that line blood vessels. After just three days in microgravity, changes in the expression of more than 11,000 genes were recorded, which can significantly alter the functionality of blood vessels. This discovery not only helps in understanding how the space environment affects the cardiovascular health of astronauts but also offers valuable data for developing therapies against heart diseases on Earth.

Neural cells and adaptation – STaARS BioScience-4

The STaARS BioScience-4 research focused on neural stem cells and their response to microgravity. The results showed increased degradation of cellular components and changes in metabolism, indicating the adaptation of cells to conditions without gravity. These findings highlight the importance of ensuring an optimal energy supply to maintain the cognitive and physiological functions of astronauts on long-term space missions.

Fish scales as a model for bones

In a study called Fish Scales, scientists used the scales of goldfish as a model for studying human bones. Since fish scales contain similar proteins, minerals, and cell types as human bones, this research helps to understand how bones adapt to different gravitational conditions. The experiment involved exposing the scales to conditions three times greater than Earth's gravity, simulated microgravity, and actual microgravity on the ISS.

Mice and stem cells – genetics and radiation

JAXA's Stem Cells project investigated the impact of spaceflight on the DNA and chromosomes of mouse embryonic stem cells. Some of the cells were genetically unmodified, while others were more sensitive to radiation. The results showed that in the unmodified cells, there were no significant chromosomal differences compared to control samples from Earth, while in the more sensitive cells, more pronounced DNA abnormalities were recorded. This research is important for assessing the risks of radiation during long space missions and for understanding the mechanisms of cancer development.

Cardiac adaptation – results of the RR-1 mission

Analysis of mouse heart tissue from the RR-1 mission, the data for which is available in NASA's GeneLab database, has shown that the heart can adapt to the stress of microgravity in just 30 days. The genetic changes discovered in the study suggest that this adaptation can help maintain heart functionality during space missions and potentially open up new approaches to treating heart disease on Earth.

The ISS as a laboratory for medical discoveries

The International Space Station serves as a unique laboratory where open data from numerous experiments are available to scientists. This data accelerates the development of new medical technologies, from organ-on-a-chip systems to three-dimensional cell cultures and organoids. Such models allow for a better understanding of diseases and the testing of therapies in conditions that realistically mimic human organs, which has enormous potential for both space medicine and healthcare on Earth.