What muscle tissue reveals about us │ Sending Worms to Space with Colleen Deane

How do labs analyse muscle tissue samples? Find out what differences exist in the muscles of older compared to younger adults in this next episode of our amazing series, Worms in Space for Health on Earth.

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During clinical trials we collect muscle tissue that we analyse in the lab to measure what is happening to the molecules within the muscle, and this can be in response to an intervention such as ageing, exercise or immobilisation. Depending on what molecules we want to look at depends on what analysis we do, and here we explain some of the most common analytical methods we perform. As you may now know, the breathing apparatus of the cells are disrupted with space flight and with ageing, so we commonly measure the breathing responses of muscle in our clinical trials.

The parts of the cell responsible for breathing are called the mitochondria, and the mitochondria use oxygen to generate energy for our cells to use. To measure the mitochondrial response to an intervention we take a tiny, tiny piece of muscle tissue, and under a microscope we pull it apart so that we can see the individual muscle fibres. We then take this tiny piece of muscle tissue and we put it into a machine called the Oroboros, and here we add different solutions to make that mitochondria work harder. Now, the Oroboris measures the oxygen that is being used by the mitochondria in response to these solutions we have added. And typically, the harder the mitochondria can work, the more oxygen they are using, and therefore the better they are.

Now, in a clinical trial that we have run, we have used this machine for analysis and found that a supplement given to ageing adults tended to improve the breathing capacity of the mitochondria. We have also mentioned that molecules involved in muscle contraction are disrupted in response to space flight and in response to ageing. And in order to measure whether these molecules go up or go down in response to these interventions, we commonly perform a technique called western blotting. And to do this we collect a tiny piece of muscle tissue and we cut it up very, very fast with scissors to release the molecules from within the muscle sample.

We then prepare this sample for a process called gel electrophoresis. Now, this separates these molecules within the sample by their weight because our molecules have different weights. And to identify the molecule that we are interested in, we add antibodies to this western blot overnight. Now, the following day we use a camera to image the western blot, which will produce black marks that are proportional to the amount of the molecule that is in the sample. So, the more intense the mark is on the blot, the more of your molecule is present.

In muscle tissue samples collected from young and older adults, we used western blotting to see what happened to the molecules related to muscle growth following exercise, and we found that the presence of growth molecules goes up more in younger versus older adults, and this was showing us that older adults don't respond as well to exercise as do younger adults. And this likely contributes to muscle decline with ageing.

How are advances in computers helping us better understand health and disease? In our next episode we'll look at how computational modelling is used to analyse results from clinical trials, and how this may help us understand health on Earth.

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