Rodrigo Fernandez-Gonzalo
Dissecting Muscle in Orbit: From Astronauts to 3D cell models
Online Summer School – Tissue Engineering & Space Medicine
25 August 2025, 11:00–12:00 CEST
About the speaker
Rodrigo Fernandez-Gonzalo is an associate professor and research group leader at Karolinska Institutet, Stockholm, Sweden. His research focuses on understanding how spaceflight affects the mass and function of skeletal muscle and how this tissue interacts with other physiological systems of the human body in space. He is also very interested in developing countermeasures to offset the deleterious effect of spaceflight on the human body. Rodrigo is the current chair of the Life Science Working Group at ESA.
Q&A
Why are only men used for these bed rest studies and others?
There are some historical aspects to this, but ESA has always tried to include women in bed rest (e.g. the WISE study) and more recently, dry immersion studies. Nowadays, the aim is to have 50/50 ration of men and women – although for unknown reasons, men are usually easier to recruit for this type of studies.
Do you think it would be meaningful to study LEO effects on muscular tissue directly via a CubeSat carrying an muscle-on-a-chip payload?
Definitely. This is something that many groups in Europe and elsewhere are doing, and it is something that ESA is trying to push, more so considering the upcoming decommission of the ISS (by 2030).
How did you collect the MASER 14 data? How do you think is interesting to measure something for 10-20 minutes if you are comparing it with t a 90/14 days experiment?
The samples were collected immediately after landing. As you point out, this experiment had some limitations, as it was a passive module. But with the appropriate fluidic and storage system (that we are planning) I consider it is very interesting to investigate the very acute changes in skeletal muscle models during short-term unloading. The data cannot be compared, but rather it should be used to build-up evidence towards a particular question/answer.
What are the advantages and disadvantages of digital twins?
This can be very useful to generate hypothesis, but I consider that now we still need classic biological evidence to corroborate the inferences obtained by digital twins models. But it is a very interesting line of research that can be applied to individualized medicine quite fast.
How does the genetic modification of our cells do you think will react in the asteroids of primary human cells model?
It will depend on the type of genetic modifications. Some will fail totally (cell/models will die), while otherswill be very useful!
In your opinion, what are the mechanisms behind the rapid recovery of satellite cells upon returning from space to earth?
Muscle plasticity. Skeletal muscle has a great capacity to recover – and satellitecells are expertes on that!
In terms of long non coding RNAs, the research was done specificfally in muscles from legs?
Yes, the experiments were done in soleus muscle of mice, and vastus lateralis from humans. The cell model was made by cells obtained from muscle biopsies from the vastus lateralis muscle as well.
Are there specific implemented countermeasures (pharmacological) to address calcium changes?
Yes, biophosphates are usually considered to address calcium changes.
What progress has been made in nutrition related to muscle preservation in space, and are the nutritional needs comparable to those of high-performance athletes on Earth?
No, they are not comparable. The main problem of astronauts when it comes to nutrition is that they do not eat enough. This is a major problem to assess countermeasure efficiency, as lack of macronutrients, eg proteins, will be detrimental for a countermeasure protocol aimed to offset muscle atrophy.
Have intracellular calcium levels been measured in these cells, as these cells are sensitive to forces during the microgravity or hypergravity phase? Do excess serum calcium levels play a role in the dysfunction of these cells?
There are some studies that have measured calcium and calcium ion dynamics. In fact, calcium ion dynamics seems to be heavily affected by space conditions – this is no surprise as there are many calcium-related aspects involved in mechanotransduction, which may prove critical to explain the changes of skeletal muscle during microgravity/space conditions.
As a bioingineering student, I’m very interested in skeletal muscle. Do you think specializing in tissue engineering would be a good path to get involved in this field, and what advice would you give me to move closer to working in this area?
Space physiology and medicine will need more and more bioengineers. We are passing from a phase where human research has been done in humans, to another where “human” research is done in (human) cellular models. The field is still rather small, but getting in contact with groups working on this, and expanding your knowledge about skeletal muscle in health and disease would be an asset.