Stem cells are powerful cells that are essential for life. Often referred to as the building blocks of the human body, stem cells are young cells that can develop into other types of cells. They perform many critical tasks that are necessary for life, including healing our injuries and maintaining the health of our internal organs.
In this article, we’ll share all of the information you need to gain a basic understand of what stem cells are and what they do. We’ll also share some of the potential applications for stem cells in the future.
What are stem cells?
You can think of stem cells as the raw materials (or building blocks) that make up the human body. They are primarily responsible for creating all of the cells with specialised functions, including the cells that make up the heart, brain, skin, lungs, and other organs.
Stem cells also serve as an internal repair system. They can regenerate tissue and play a role in healing certain types of injuries. For example, if you cut your finger, stem cells will be prompted into action, creating more skin cells to heal the injury.
There are three major differences between stem cells and the other cells within your body:
1. Stem cells are not specialised
Most of the cells in the human body are specialised. That is, they have a special task to perform and are designed to perform it. A red blood cell looks very different to a skin cell and has vastly different capabilities. It must carry oxygen around the body and remove carbon dioxide, while skin cells must interlock with other cells to create skin. Stem cells are not specialised to perform a certain task.
2. Stem cells can renew themselves through cellular division
Stem cells are self-sustaining and can divide to make more stem cells. This is different to specialised cells like muscle, blood, or nerve cells, which cannot duplicate themselves.
3. Stem cells can change into specialise cells
The body uses chemical signals to tell stem cells to differentiate into specialised cells. Some stem cells will only be able to change into a specific type of specialised cell, while others can change into multiple types of cells (more on that shortly).
Some types of stem cells are extremely active, constantly dividing to make more stem cells and differentiating into specialised cells, while others are not. For example, the stem cells in your bone marrow will constantly be active, as they must continually produce new blood cells. However, the stem cells in your pancreas or heart will only divide under specific conditions.
Types of stem cells
There are four types of stem cells: embryonic stem cells, cord blood stem cells, adult stem cells, and induced pluripotent stem cells.
Embryonic stem cells
Embryonic stem cells only found in unborn children during the embryonic stage of development. An embryonic stem cell is pluripotent, which means it can change into any of type of specialised cell — obviously essential for an embryo, which is building all of the organs, tissue, and bones it requires.
As the embryo develops, the pluripotent stem cells will turn into multipotent stem cells. Multipotent stem cells are only capable of differentiating into certain types of specialised cells. Some multipotent stem cells are limited to differentiating into related types of cells. For example, a blood stem cell (called a hematopoietic stem cell) can only differentiate into a white blood cell, red blood cell, or platelets.
The types of cells that stem cell can turn into is often dictated by where in the body the stem cell is located. Some stem cell cells have the opportunity to change into vastly different cells, depending on where they travel to.
Cord blood stem cells
After the baby is born, some stem cells are left in the umbilical cord and placenta. These stem cells can be safely extracted for medicinal use. They include hematopoietic stem cells and other multipotent stem cells, along with some very powerful growth factors. Umbilical cord blood stem cells are the focus of much research because they are easily obtained and have a lower risk of rejection when used in a stem cell transplant.
Learn more about cord blood stem cells:
Potential Treatment of Autism in Children Using Cord Blood Stem Cells
Cord Blood Stem Cells Therapy: The Past, Present, and Future
The Benefits of Saving Umbilical Cord Blood Stem Cells
The Remarkable Qualities of Umbilical Cord Blood Stem Cells
Adult stem cells
Adult stem cells are also called somatic stem cells or progenitor cells. They are located throughout the body in small quantities. In most cases, they will generate cells appropriate for their location. So, stem cells located near the heart will differentiate into heart cells. If those stem cells were removed from near the heart and placed elsewhere, they might create a different kind of cell.
Induced pluripotent stem cells (iPSCs)
In 2006, a team of Japanese researchers led by Shinya Yamanaka created Induced pluripotent stem cells. These cells can be created adult somatic cells including skin cells and blood cells using genetic reprogramming. This technique has allowed researchers to create the powerful form of stem cell and has led to numerous research breakthroughs.
What are the potential uses of stem cells?
Researchers have discovered hundreds of potential uses for stem cells, many of which have already led to the development of successful treatments. There are already more than 70 different treatments already available which use hematopoietic stem cells (blood-forming stem cells). This includes treatments for various forms of cancer, blood disorders, metabolic disorders, and immune system disorders.
There are many new stem cell therapies currently in development which may lead to treatments for:
- Heart disease
- Parkinson’s disease
- Type 1 diabetes
- Alzheimer’s disease
- Stroke
- Spinal cord injury
- Liver disease
- Macular degeneration
- Multiple sclerosis
Many of these potential treatments use stem cell transplants or techniques that encourage stem cells to become more active. Once the procedure is performed, the stem cells will begin to regenerate the affected tissue by creating new specialised cells.
Stem cells have also proven to be useful for drug testing, as researchers can create organs in vitro, then test how new drugs affect them. They can also personalised drugs which are designed to be compatible with a person’s genetics or immune system.
Sources
https://stemcells.nih.gov/info/basics/1.htm
https://www.loc.gov/rr/scitech/mysteries/stemcells.html