One of the hazards astronauts must contend with is muscle loss. The more time they spend in a microgravity environment, the more muscle loss they suffer. Astronauts use exercise to counter the effects of muscle atrophy, but it’s not a perfect solution. Researchers want to develop drugs to help, and understanding the muscle-loss process in space is a critical first step.
In the early days of space travel, researchers weren’t certain what effects microgravity had on astronauts. As the length of space missions grew and scientific monitoring became more prevalent, researchers gained a better understanding of the problem. After the Skylab missions in 1973 and 1974, researchers acquired better data and began to reach some conclusions. It was clear that microgravity contributed to a host of health problems, and muscle atrophy was among them.
Many of the problems astronauts suffer mimic the same problems stemming from aging.
“Space is a really unique environment that accelerates qualities associated with aging and also impairs many healthy processes,” said Ngan Huang, an associate professor at Stanford University. “Astronauts come back with muscle atrophy, or a reduction of muscle function, because the muscle isn’t being actively used in the absence of gravity. As space travel becomes more common and available to civilians, it’s important to understand what happens to our muscle in microgravity.”
Huang is the co-author of new research published in the journal Stem Cell Reports. The study is “Skeletal muscle-on-a-chip in microgravity as a platform for regeneration modeling and drug screening.”
Age-related muscle loss is called sarcopenia. Many factors, including immobility, hormonal changes, and even nutrition, contribute to sarcopenia. Currently, there aren’t any FDA-approved drugs to treat the condition, so exercise, lifestyle, and nutrition are the only ways to treat it. Exercise is critical for astronauts in their struggle against muscle loss. However, space for exercise equipment is limited on the ISS. An effective medication to treat astronaut sarcopenia would be a huge boon.
In this new research, the researchers grew live muscle cells on scaffolds on tiny chips and then sent them for study in microgravity aboard the ISS. The cells grew for seven days under the watchful eyes of astronauts and were exposed to a pair of used to counteract sarcopenia and enhance muscle regeneration. Then, they compared the microgravity muscle cells to ones grown under normal gravity in a lab here on Earth.
This figure from the research gives an outline of the study. (A) shows human muscle cells were seeded onto collagen scaffolds, then placed into a bioreactor with media to become muscles on a chip. (B) shows an overview of the experiment, including travelling to the ISS, being exposed to different drugs, and later extracted and analyzed. Image Credit: Kim et al. 2024.The results showed that the microgravity muscle cells had impaired muscle fibre formation, differences in gene activity, and differences in their protein profiles.
Muscle tubes, or myotubes, are precursors to muscle fibres. The study results showed reduced myotube length and width, as well as a reduced fusion index. The fusion index basically tells researchers how many muscle cell nuclei are present.
The mitochondria generate most of a cell’s energy, and the results showed that genes affecting their function were compromised. Since muscles have such high metabolic function, any impairment to mitochondria will play out in reduced muscle regeneration. Results also showed that genes associated with forming fat were bolstered. The researchers say the combined effect takes a large toll on muscle regeneration in microgravity.
Protein profiles are like snapshots of what cellular machinery is doing at a particular time. They reveal critical information about the cell’s function and health. In this research, the team examined 200 different proteins.
The results showed that five proteins were produced in greater abundance. Two of those are associated with chronic inflammation, and one is “a biomarker for mitochondrial dysfunction and cellular senescence.” Four of the proteins showed reduced abundance. One of those is “an important player in the maintenance of muscle and myogenesis,” the researchers write in their paper.
This image shows the “muscles-on-a-chip” experiment. Image Credit: Kim et al. 2024.Overall, the changes the muscle cells underwent shared similarities with changes induced by aging.
“We think our research on muscle chips in microgravity may have broader implications on sarcopenia,” says Huang. “Sarcopenia usually takes decades to develop on Earth, and we think that microgravity may have some ability to accelerate the disease process in orders of days.”
The research also helped understand the role drugs could play. “We next used the muscle-on-a-chip platform to perform proof-of-concept drug screening studies,” the researchers write. They exposed the cells to drugs used to counteract sarcopenia and enhance muscle regeneration.
Geneticists use the terms down-regulation and up-regulation to describe negative and positive effects on gene expression. They found that 286 genes were down-regulated in microgravity. Of those, 200 showed a positive response to drug treatment and similar expression levels to cells in normal gravity.
These Venn diagrams from the research show upregulated genes (left) and downregulated genes (right) in microgravity. The two drugs tested in the research are IGF-1 and 15-PDGH-i. The study showed that 286 genes in muscle tissue are downregulated in microgravity and that 200 of them responded positively to drugs. Image Credit: Kim et al. 2024.“In conclusion, we show that engineered muscle-on-a-chip bioconstructs exposed to microgravity induced prominent changes to their transcriptome that mimic aspects of impaired myogenesis,” the authors write.
Space research is difficult and resource-intensive, so the researchers intend to continue their work using equipment that mimics microgravity to dig deeper into the issue here on Earth. In 2025, the muscles-on-a-chip are scheduled for another space flight. That experiment will help to identify more drugs that can combat muscle loss.
The benefits of this research extend beyond just muscle loss. “This concept of engineered tissue chip platform in microgravity is a potentially transformative tool that could allow us to study a variety of diseases and do drug screening without animal or human subjects,” says Huang.
The authors conclude in their paper, “This work further highlights the utility of microgravity as a unique environment for drug discovery.”
The post Being in Space Mimics Age-Related Muscle Loss appeared first on Universe Today.
What does it take to have life at another world? Astrobiologists say you need water, warmth, and something for life to eat. If it’s there, it’ll leave signs of itself in the form of organic molecules called amino acids. Now, NASA scientists think that those “signatures” of life—or potential life—could exist just under the icy surfaces of Europa and Enceladus.
If future explorations find those signatures, it’ll make a major step in the search for life elsewhere in the Solar System—and beyond. That’s one reason why robotic missions will someday land on those moons—to look for the signs of life. The next mission to Europa, called Europa Clipper, will orbit that tiny moon, but won’t land. However, it will look for environments suitable for life. So, that’s a start. There’s also a proposed mission called Enceladus Orbilander. It could launch in 2038 and spend a year checking out that moon.
The Search for Life SignsScientists strongly suspect there’s a warmish salty ocean beneath the ices of both Europa and Enceladus. Moreover, they are probably heated by tidal stresses. So, those are two of the ingredients for life right there. Given what we know about these worlds, there could be something to feed that life, too.
If life does exist, it could “imprint” its existence in the form of amino acids, nucleic acids, and other organic molecules in the surface ice. Life probably wouldn’t exist right on the surface, mostly due to radiation and the lack of atmosphere at those worlds. That makes the near sub-surface ice a good place to look for evidence of that life. That will require a little digging to find the evidence. How deep? According to Alexander Pavlov of NASA Goddard Space Flight Center, it wouldn’t be far.
“Based on our experiments, the ‘safe’ sampling depth for amino acids on Europa is almost 8 inches (around 20 centimeters) at high latitudes of the trailing hemisphere (hemisphere opposite to the direction of Europa’s motion around Jupiter) in the area where the surface hasn’t been disturbed much by meteorite impacts,” Pavlov said. “Subsurface sampling is not required for the detection of amino acids on Enceladus – these molecules will survive radiolysis (breakdown by radiation) at any location on the Enceladus surface less than a tenth of an inch (under a few millimeters) from the surface.”
Testing that HypothesisOf course, scientists don’t have any samples of ice on hand to study from either Europa or Enceladus. So, Pavlov’s team simulated the conditions to see if rovers and landers could find evidence of organic materials and life on those worlds. They used amino acids in ice and those from dead microorganisms in radiolysis experiments as possible representatives of biomolecules on icy moons. Radiolysis uses ionizing radiation to bombard molecules and break them apart.
Experimental samples of amino acids (as fingerprints of life) were loaded into a dewar and bombarded by gamma radiation. Credit: Candace Davison.The team mixed samples of amino acids with ice chilled to about -196 Celsius and bombarded them with gamma rays. Since the oceans might host microscopic life, they also tested the survival of amino acids in dead bacteria in ice. Finally, they tested samples of amino acids in ice mixed with silicate dust. That tested the potential mixing of material from meteorites or the interior with surface ice.
Amino acids are interesting because life can create them. Other non-biological chemistry processes also make them. Scientists studied specific kinds of amino acids that could exist on Europa or Enceladus, particularly those amino acids from the microorganisms they tested (called A. woodii). If other microorganisms similar to that one existed at Europa or Enceladus, they could be a potential sign of life. That’s because they are used by terrestrial life as a component to build proteins. Those make enzymes that speed up or regulate chemical reactions and make structures.
Moving Evidence of Life to the Icy SurfaceIf such life did exist on either world’s subsurface oceans, the next question is how its “fingerprint” amino acids get to the ice so close to the top layers of ice. There’s evidence of resurfacing at both worlds by ocean water from below. On Europa, there are surface units much younger than others, which indicates that water makes its way to the surface and freezes. On Enceladus, geysers shoot material out to space from below the surface. Amino acids and other compounds from subsurface oceans could be brought to the surface by geyser activity or the slow churning motion of the ice crust.
Europa’s bizarre surface features suggest an actively churning ice shell above a salty liquid water ocean. That liquid could carry amino acids and signs of life to the surface. Credit: JPLSo, it looks like the team’s experiment shows that amino acids could survive on both worlds, under certain conditions, but they also degrade at different rates. That’s important news for future missions, according to Pavlov.
“Slow rates of amino acid destruction in biological samples under Europa and Enceladus-like surface conditions bolster the case for future life-detection measurements by Europa and Enceladus lander missions,” he said. “Our results indicate that the rates of potential organic biomolecules’ degradation in silica-rich regions on both Europa and Enceladus are higher than in pure ice and, thus, possible future missions to Europa and Enceladus should be cautious in sampling silica-rich locations on both icy moons.”
For More InformationNASA: Life signs Could Survive Near Surfaces of Enceladus and Europa
The post We Might Find Life Just Under the Surface on Europa appeared first on Universe Today.
Like several people I know, I’m caught up in a temporary fit of the downs because the world seems to be going off kilter. I worry about politics, I worry about Israel, I worry about Ukraine, I worry about Iran and its forthcoming nukes, I worry about fulminating wokeness and its effect on science, and, well, the list goes on. But something is keeping me awake at night. Although I don’t lie abed racked with conscious worries, my theory (which is mine) is that the worry has become internalized. Further, it’s hard, for me at least, to avoid converting the worry into anger, as it’s made me short-tempered, so I have to exert more control over my behavior.
So much for the personal stuff. But since all the stuff I have to write about is depressing (in the wings are articles about the ideological capture of chemistry, Wikipedia’s “Jewish problem”, the school curriculum in New Zealand—in other words, the kind of thing you see her regularly), there’s no light at the end of the tunnel. I’m thinking of writing about more personal stuff, just to improve my writing and go off on a different tangent. But there will always be the Hili dialogues with their daily five news items.
Do recall that on Saturday I leave for a month in South Africa, and posting will be very sparse for that month and somewhat sparse from now until Saturday.
So let’s have a couple of polls—about politics, of course. Please vote if you’re reading this and, more important, explain your feelings below if you wish.
First poll:
Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.Second poll (remember, all answers are anonymous and I don’t know who votes which way):
Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.Weigh in below. You needn’t tell me that this is not a scientific poll. It’s simply a survey of the readers.
Sometimes, brainstorming does work. In 2019, America’s National Science Foundation (NSF) held the CubeSat Ideas Lab, a shindig that brought together some of the world’s best CubeSat designers. One outcome of that shindig is the Virtual Super-Resolution Optics with Reconfigurable Swarms, or VISORS, mission. Expected to launch in October, this mission will be a proof of concept for many swarming technologies in CubeSats. Hopefully, It will also capture a pretty impressive picture of the Sun’s corona.
VISORS was formally defined in a paper in 2022, with input from experts at nine different academic institutions, one NASA lab, and one private lab. The concept of operations (or ConOps in the paper) is easy enough – fly two separate 6U CubeSats in formation and take an extreme ultraviolet picture of the Sun.
The obvious question is—why do you need two CubeSats to do that? A single spacecraft could do the job, but the science goal of the VISORS missions is to take an image at a very high resolution in a very specific extreme ultraviolet wavelength. To do that, the mission would need an optical mirror diameter of around 40m.
Fraser discusses how swarms could change how we explore the solar system.That is beyond humanity’s current capability to fit onto a rocket fairing and blast into space. So, VISORS will actually consist of two spacecraft. One, known as the Detector Spacecraft (DSC), will house an ultraviolet detector, and one, known as the Optics Spacecraft (OSC), will act as an optical system that mimics the characteristics of a 40m diameter mirror.
However, the secret sauce of the VISORS mission lies in the coordination between the DSC and the OSC. They will fly in formation with each other, about 40 m apart, with the OSC placed between the Sun and the DSC. The light from a specific region of the Sun’s corona will pass through a photon sieve on the OSC and be directed into the detector of the DSC 40 m away, effectively creating the effect of a 40m wide mirror without the need for a continuous surface.
The only problem is that this type of coordinated alignment between CubeSats has never been done before. So, really, the VISORS mission could be looked at as a technology demonstration mission for CubeSat swarm formation rather than a heliophysics one. The mission statement in the ConOps paper states that the mission will be considered successful if it captures one ten-second image over the course of a six-month primary mission duration.
YouTube video from the Space REndezvous Laboratory describing VISORS formation.Ten seconds out of almost 16 million may not seem like much, but it shows the difficulty of getting CubeSats to align properly at the right time. To do so, researchers at the Space Rendezvous Laboratory at Stanford have created novel Guidance, Navigation, and Control (GNC) software based on a concept familiar to any controls engineer—a state machine.
In software, a state machine is defined by various variables that will change the software’s behavior based on the values of those variables. In the case of VISORS, there will be five different states. Standby is pretty self-explanatory – wait in your current orbit for further instructions. Transfer is an attempt to move into formation to allow the system to capture an image. Science is when the mission will attempt to capture that ten-second image. But if something goes wrong, it also has two recovery states – Safe mode is pretty standard for all spacecraft, but Escape mode is unique for VISORS. This would move either spacecraft out of the way of the other, and collision between the two is one of the primary risks of the mission architecture and one of the things the GNC algorithm is designed to avoid.
Development of that software appears to be ongoing, though the planned launch date for the mission is only three months away. If all goes well and VISORS is successfully deployed and takes at least one picture, that proof of concept will shortly enable plenty more CubeSat swarm missions. It might even inspire more successful brainstorming Idea Labs.
Learn More:
Lightsey et al – CONCEPT OF OPERATIONS FOR THE VISORS MISSION: A TWO SATELLITE CUBESAT FORMATION FLYING TELESCOPE
UT – What a Swarm of Probes Can Teach Us About Proxima Centauri B
UT – Tiny Swarming Spacecraft Could Establish Communications with Proxima Centauri
UT – A Pair of CubeSats Using Ground Penetrating Radar Could Map The Interior of Near Earth Asteroids
Lead Image:
Artist’s depiction of the VISOR spacecraft flying in formation.
Credit – Simone D’Amico
The post Taking a High-Resolution Ultraviolet Image of the Sun’s Corona Will Require VISORS appeared first on Universe Today.