The stem cell, one of the most extraordinary cells in our body

In the recent years you must have heard of it at least once: the stem cell. With our gained knowledge on the stem cell over the past few years they have become a major focus point of new treatments, the so called stem cell therapies. Part of the whole stem cell therapy hype is that it can be used to treat lots of different diseases  including diabetes, Alzheimer, heart infarction and cancer. However all of the treatments are still under investigation with an exception for bone marrow transplants that are already being used for several years. Which is not remarkable because the stem cells also were discovered in the bone marrow.

So what is actually this stem cell? Where does it come from? And why is it so important that many researchers are dedicating their lives to it?

Figure 1 Dividing stem

 cell into another stemcell

and into a more specialized cell.

First of all you should know that a stem cell has the capability to form lots of different cell types in the body, this is why they are an essential cell type in early life. We are then talking about the time you were not more than a clump of cells in your mother belly. But also later on, when they can form not as much cell types, they still serve you as an important internal repair mechanism. The stem cell can namely divide into two cells, one of those can become a more specialized type of cell like a muscle or red blood cell, whichever is needed for repair. The other cell can choose to stay a stem cell and won’t specialize so it can again form two more cells (fig. 1). This unique capability to renew itself and as well form a more specialized cell sets it apart from all the other cells in the body. However in reality not all stem cells can form all types of cells, this is described by the potency of a stem cell. The potency says something about how many different cell types can be formed. Mainly two distinctions can be made, the first are stem cells capable of forming all/almost all cell types, which are only found in the embryo. The second being stem cells that can still form quite a few different cell types but near all, these stem cells can be found in adults. These two different potency levels give rise to the two major divisions of stem cell types. The first are the embryonic stem cells which are capable of forming all/almost all and responsible for forming us from egg and sperm cell to human.  And the second are the less potent adult stem cells found in numerous but not all organs where they act as the repair mechanisms for our adult bodies. For example in our gut which gets damaged a lot by al the food that passes through.                                                                                                                           

You mainly want the embryonic stem cells for stem cell therapy because these are capable of forming all the cells you need. There are however two main obstacles using the embryonic stem cells in therapy. The first being that embryonic stem cells are derived from an embryo of another individual. This way there is a chance that they are rejected by the body, just like an organ could in an organ transplant. The second is a non-technical issue namely an ethical issue, because when you take stem cells from a human embryo you destroy it as well and for some this is in principle the same as killing a full grown human. So embryonic stem cells are not a really a good option to base therapies on. However all hail biologists, because the last few years researchers found a solution to both these problems by finding a first thought impossible way of transforming specialized cells of your own adult body back to stem cells that have the same properties as embryonic cells.

                So now were here right we have the stem cells that can form all kinds of cells just implant them and we can regrow everything, but unlucky for us it is again not that simple. There are still major issues when it comes to actually using these cells. The cells need for one to be adjusted at your organ, like a transplanted cardiac cell must beat at the same rhythm as your own heart. Furthermore there are lots of complications like an increased risk in getting cancer. So there is still a long way to go but scientists all over the world are researching hard to solve all these problems to ultimately treat diseases that you or a loved one may suffer from one day.

By Rolf Tonckens