There has been a lot of attention paid to stem cells in recent years, particularly in the news, but what exactly are they?
Stem cells are basically the building blocks of organisms. They exist in our bodies and every other multicellular organism on the planet. In humans, they are most active during early development, but they remain in certain areas of the body after we become adults.
Their role is to create different types of cells. They do this by dividing. When a stem cell divides, each new cell will either remain a stem cell or turn into one of the many different cells (muscle, nerve, red blood cells etc.). These specialised cells are designed for growth and repair.
Where do stem cells come from?
Let’s look at three different sources of stem cells.
Embryonic stem cells come from blastocysts, which are embryos that are five to seven days old. They are pluripotent, which means they are able to differentiate into any type of cell that is needed.
Adult stem cells can renew themselves or change into a specialised cell type in order to maintain or repair the tissue (or organ) in which they are found. Adult stem cells are generally found in specific tissue or organs like bones, skin, liver and the lining of the stomach and gut.
Induced Pluripotent stem cells are a new type of stem cell that can be made in the laboratory. Scientists effectively take a cell from the body and genetically reprogrammed it back into a stem cell with qualities similar to those of embryonic stem cells (i.e. pluripotent).
What’s so interesting about stem cells?
Studying how stem cells act within the body and also in the laboratory can assist doctors and researchers with a number of areas including:
Understanding disease - we can now use stem cells created from a patient's cell to directly study the 'disease in a dish', providing a new window into what happens during illness and injury.
Regenerative medicine - because stem cells are naturally encoded for growth and repair, there is potential for them to be used to regenerate tissue that is damaged or diseased. Using stem cells as a form of therapy is nothing new. Stems cells located in bone marrow and in umbilical cord blood are used to treat blood-related and immune diseases. They are also used to help heal the body after chemotherapy. The focus now for many researchers is how to coax stem cells in other organs to similarly restore function and health.
Testing new drugs - pharmaceutical drugs go through a thorough process to ensure effectiveness and safety before they can be used by the public. Cells made from human stem cells can be used to aid and possibly accelerate this testing process.