A gravity free environment weakens muscles just as aging does, except the process is rapidly accelerated.
This understanding led to MicroAge, a scientific space mission to explore processes that will help preserve muscle strength in old age. The mission was launched in a SpaceX Falcon 9 rocket from the Kennedy Space Center in December. Here’s the fascinating story…
With aging comes many health challenges, one of which is physical frailty. This is a major factor in a person’s ability to maintain independence and quality of life. This progressive loss of skeletal muscle mass, strength, and function with aging causes an increase in falls, functional decline, and mortality.
In recent years this condition, known as sarcopenia, has been the focus of intense research to improve diagnosis, treatment, and prevention strategies. The research effort has now extended to space.
Protein Protection Fails in Seniors
Resistance training is one method of keeping muscles in good shape. Though it slows muscle loss, studies in aging animals and humans show this loss cannot be stopped.
Astronauts also lose skeletal muscle mass—among other things— and even though they undertake extensive daily aerobic and resistance training in space, it doesn’t prevent the loss of a significant amount of muscle tissue.
Since the same effect happens in both aging and the microgravity of space, scientists at Liverpool University theorized that by studying how muscles respond to repeated contractions in space, they would get a better understanding of why muscles fail to fully respond to exercise.
Preparation for the project took three years during which the research team evaluated key mechanisms that underlie how skeletal muscle adapts to exercise. These demonstrated that in young or adult animals and humans, free radicals are generated that stimulate the activation of proteins that protect cells. This doesn’t occur in older animals and humans.
The researchers needed to confirm the process could be studied in cell culture models, which they were able to do. This provided the basis for planned experiments using cultured constructs of skeletal muscle cells placed on the International Space Station (ISS).
A Mission with Many Challenges
The research team designed a scaffold to support the muscle cell cultures so that they could grow in an environment without gravity. They also had to make sure they would survive temperature changes, vibration and the pressure of G forces during launch.
The lab grown human muscle cells were placed into small containers for the journey, and they’ll be electrically stimulated to contract, and the responses examined at the ISS. At the end of the experiment, the muscle cells will be frozen and returned to Earth, after which they will undergo further analysis.
Malcolm Jackson, Professor of Musculoskeletal and Aging Science, said, “Aging is one of the greatest challenges of the 21st century and we will learn a great deal about how muscle responds to microgravity and aging from the data we obtain from this study.
“The team has had to work extremely hard over the last three years to overcome the many challenges of sending our science into space.
“For example, the electronic equipment necessary to undertake these studies usually fills a large desk but we have managed to shrink this to the size of a pack of cards. This development work on automated and miniaturized systems represents an exciting innovation that could have a wider application in the future.”