Cook Myosite Blog

What Is and Is Not a Stem Cell?

Posted by Cook MyoSite on Aug 18, 2021 4:51:44 PM
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Stem cells have been the center of medical intrigue for much of the last few decades. During this time, the differences between the popular and the scientific conceptions of what is and isn’t a stem cell have grown. Often, the public's understanding of stem cells is far narrower than how the term is applied by scientists. What is a stem cell? Does Cook MyoSite work with stem cells?

skeletal muscle myoblasts
A magnified image of skeletal muscle myoblasts, myocytes, and myotubes stained with Desmin (a muscle cell marker),
and DAPI (Nuclear stain). These cell types are derived from muscle satellite cells.

What is a stem cell?

Most cells in your body serve a specific function. Muscle cells contract when stimulated by an electrical signal from the brain, red blood cells carry oxygen all over the body, and skin cells form our protective covering. Stem cells, however, are unique: they are unspecialized cells that do not yet serve a specific function within the body. Instead of doing the day-to-day work that most other cells do, stem cells exist to either a) divide into more stem cells, or b) produce a cell with a specific function, like a muscle cell. They can be thought of as the body’s raw materials: stem cells are the precursor cells to all other cells.

This ability to produce other, more specialized cells – a process known as “differentiation” – is what makes stem cells so intriguing to researchers. Because stem cells have the potential to become new, functional cells, researchers are looking into the many ways that stem cells could be used to replace damaged or dysfunctional cells that might be causing a particular ailment. To date, there has been research on the potential of stem cells as a treatment for cancer, diabetes, Alzheimer's disease, and many other diseases.

There are many popular misconceptions about stem cells, but one of the most common is that stem cells only come from embryos. In fact, stem cells can be derived from a variety of adult tissues such as adipose (fat), muscle, bone marrow, dental pulp, or umbilical cord blood. There are important differences between embryonic stem cells and the stem cells found in adult tissues, most notably that embryonic stem cells can give rise to many different types of cells (referred to as “pluripotency”) while adult stem cells can usually only differentiate into a few different types of cells (referred to as “multipotency”).


What is a satellite cell?

The term “satellite cell” is another name for adult muscle stem cells. At Cook, the cells we work with are satellite cells. These satellite cells are the source of new cellular material that your muscles need to regenerate after injury or exercise. When a muscle fiber is damaged, the satellite cells near the damaged tissue activate, divide, and fuse together to replace the damaged portion of the muscle. Many adult stem cell populations, such as adipose-derived stem cells, mesenchymal stem cells, and muscle stem cells are all currently being investigated for the treatment of various clinical conditions in labs all over the world.


What is the distinction, and why does it matter?

It is important to draw a line of distinction between embryonic stem cells and adult stem cells because the two serve different functions, are collected using different methods, and are valued by researchers for different applications. Embryonic stem cells are valued due to their ability to differentiate into any kind of specialized cell, but they are also difficult and costly to obtain, isolate, and grow, and their use in research is controversial as they must be obtained from a human embryo. On the other hand, adult stem cells (like the satellite cells we utilize) are collected from specific tissues or organs in post-natal humans via a common procedure known as a biopsy. These cells maintain the specialized bodily function of whatever tissue they were collected from – as discussed above, adult muscle stem cells can only differentiate into various types of muscle cells.

These two types of cells both fall under the broad category of “stem cells,” but there are significant differences between the two ranging from the method of collection to the actual function of the cells. These differences often get swept aside in the public discourse surrounding stem cells, but a little awareness about the different types of stem cells can go a long way in helping to understand the processes behind regenerative medicine and some of this era’s most exciting medical research.  

Topics: regenerative medicine, stem cells