Research conducted aboard the International Space Station will look at how nerve cells interact with key immune cells of the brain in low-gravity conditions. The goal is to better understand nervous system damage in Parkinson’s disease and multiple sclerosis (MS) — and help improve their treatments.
“This is the first time anyone is researching the effects of microgravity and spaceflight on such cells,” Andres Bratt-Leal, a stem cell expert with Aspen Neuroscience and one of the project’s lead scientists, said in a NASA press release, written by Charlie Plain. “These cells are hard to study in a lab because of the way gravity influences them. The cool part is now we can do it in space!”
The research was sparked by scientists’ observations of the activation of dormant viruses in astronauts aboard space missions.
The study, “The Effects of Microgravity on Microglia 3-Dimensional Models of Parkinson’s Disease and Multiple Sclerosis,” will explore how spaceflight changes the immune system. The investigators suspect that altered immune processes drive damage in both disorders.
To learn more, they are focusing on neurons and microglia — immune cells of the brain that, when acting normally, defend nerve cells from invaders.
“Microglia are found in every part of the brain, and it’s really starting to look like neurodegenerative illnesses develop because the cells begin behaving improperly or overreacting,” said Valentina Fossati, an MS researcher with the New York Stem Cell Foundation Research Institute, and the project’s co-lead researcher. “Misbehaving microglia may contribute to killing the neurons.”
These cells cannot be collected safely from the brain. So, Bratt-Leal and Fossati are using an approach called induced pluripotent stem cells — in which adult cells are genetically reprogrammed to an embryonic–like state — to make neurons and microglia from skin cells in the laboratory.
The first cells were recently launched into space aboard SpaceX CRS-18. Over the course of 30 days, the cells will be grown into 3D models called organoids, which enable a view both of how nerve cells organize, and how microglia respond to and infiltrate them.
The cells are then returned to Earth for the team to evaluate their shape and arrangement. The researchers also will test whether microgravity — known to increase proliferation and delay differentiation of stem cells — and exposure to space radiation can alter gene expression. That’s the process by which information in a gene is synthesized, or used to create a working product, like a protein.
“We know that forces can influence the behavior of cells by changing aspects such as their shape. So, what happens when you remove gravity?” Bratt-Leal said. “How the cells respond will tell us new things about how they function.”
The cells are now inside CubeLabs, automated modules developed by Space Tango. Inside the CubeLab — approximately the size of a small shoebox — is a camera and a pair of containers. One container holds cells of a Parkinson’s patient and a healthy person, called a control, while the other has cells of an MS patient and a healthy donor. The cells are fed through a tubing and pump system connected to the chambers.
In addition to key insights into the processes of these diseases, understanding how microgravity affects the growth and survival of nerve cells is key to better protecting astronauts in space, particularly on long-duration missions, they added.