Stem Cells: How The Body’s Natural Repair System Works

16/09/2016

Not a week goes by without a headline concerning stem cells; whether it be how they can now treat diabetes, reverse the symptoms of MS, regenerate new bone tissue, or grow organs from scratch. But what actually are stem cells, and what is it that makes them so special?

Around 200 different kinds of cells make up our bodies.

Each of these cells has its own specialisation, such as blood, bone, muscle, fat, or skin, and is one building block in the foundation of all our tissues and organs.

It’s by looking at the origin of these incredibly important specialised cells that we come to our stem cells.

A stem cell is a type of ‘unspecialised’ cell which has not yet been assigned a particular role. However, their fundamental job is clear: To provide whatever cells the body needs in early life and growth, as well as in later life to serve as a sort of internal repair system, dividing and replenishing other cells for as long as the person or animal is alive.

So according to which stage of life they support,  we can divide stem cells into one of two types:

Embryonic Stem Cells

Embryonic stem cells play an integral part in the creation of life. They’re derived from ‘blastocysts’ – microscopic structures formed in the early development of all mammals which subsequently go on to form the embryo.

Embryonic stem cells have been the centre of much controversy for many years, with moral and ethical concerns about their harvesting in which embryos are created, used, and ultimately destroyed.

Adult Stem Cells

Adult or ‘somatic’ stem cells are found in the body after development, alongside other specialised cells. Their primary role is to maintain and repair the tissue in which they are found.

Adult stem cells have been used in treatments for nearly half a century, ever since they were first identified in bone marrow. Today they’re primarily sourced from bone marrow and umbilical cord blood and used in stem cell transplants for patients with illnesses and conditions such as leukaemia and lymphoma.

Adult stem cells have generated a lot of excitement recently as they’ve been found in more tissues than scientists were previously aware of. Chances are if you hear about a new stem cell breakthrough today, adult stem cells are behind it.

Although all stem cells are similar in that they’re precursors  – cells that give rise to other cells – some are more powerful than others. These more functional cells are known as ‘pluripotent’ and have the ability to develop into any cell type in the body. This is in contrast to stem cells which are ‘multipotent’ and limited to developing a specific kind of cell such as blood cells.

Every adult stem cell is believed to belong to one of two groups, mesenchymal stem cells (MSCs) or hematopoietic stem cells. The difference between the two is clear: MSCs are multipotent, possessing the power to differentiate into any cell, while hematopoietic stem cells are multipotent, and therefore only able to form blood cells.

For a long time, scientists believed the embryo was the only source of pluripotent stem cells. This was disproved, however, when MSCs were found to make up a small proportion of the population of bone marrow stem cells. And more recently, the theory was blown out the water with the discovery that our teeth are a rich source of mesenchymal stem cells.

A sign of how much potential these types of stem cell hold first came to light in the 1990s. Up until this point, it was believed the adult brain could not physically generate new nerve cells. But despite these reports, researchers discovered the brain contains stem cells able to produce any of its three major cell types.

So now we know what stem cells are, where to find them, and why they are so important to the development and maintenance of the body. But if stem cells are so great, why aren’t they able to protect the body against disease and more serious injuries?

Harnessing The Power of Stem Cells While You Can

Stem cells are a very limited and precious resource in the body.

For example, let’s consider cord blood – a rich source of hematopoietic stem cells and a much sought after treatment for blood disorders.

If successful, one collection of blood from a baby’s umbilical cord may yield around 50ml. Given that viable stem cells are found in the collection, it may be a sufficient amount to use in the treatment of one child. However, it won’t be not enough for the treatment of an adult.

We now know that stem cells do also reside in other places throughout the body, such as our bone marrow, blood vessels, peripheral blood, teeth, and skeletal muscle, but the fact is that they only ever seem to exist in very limited quantities.

On top of this limited availability, stem cells are also not immune to the effects that cause other cells and tissues to break down and age.

Scientists understand that stem cells can divide for a long period of time, but as they gradually become more and more damaged by reactions associated with ageing and the likes of pollution, it’s this ability to divide that becomes impaired and less effective.

The fact that our stem cells degrade acts as a testament to harnessing their incredible capabilities while you can. And thanks to the technology we have to isolate stem cells from our bone marrow, cord blood, and teeth, along with banks that allow us to store them, you can do just that.

Looking Ahead To A Bright Future

There are still a lot of questions regarding our stem cells which researchers around the world are working tirelessly to answer. For instance, as the availability of stem cells is limited, how can we proliferate their number and increase their capacity to self-renew? And, what are the factors that stimulate stem cells to relocate to sites of injury or damage?

But as you can see, over the past few decades many questions have already been answered. The main one of which is how the body repairs itself; creating new immune cells when hit by an infection, generating neurones when suffering from a brain injury, or developing skin cells after a first-degree burn.

It’s this inherently natural way in which stem cells work that makes them a subject of such importance, and for many, the answer to making medicine and health care so much more effective.

Are you prepared for a future of stem cell therapies? Contact us today to find out how we can help safeguard the health of your children by storing stem cells from milk teeth.