What Are Stem Cells?
Before we can delve into the research and potential of stem cells, it’s important to first understand what they are and how they function.
Stem cells exist inside all of us and they are what we are originally created from. Stem cells are their own unique cell which continues to divide and grow while the person or animal is living. When a stem cell divides the two new cells can remain stem cells or they can turn into different cells with specialized functions, such as a muscle cell or red blood cell. In this way stem cells are like a universal remote, they can be used to make any other type of cell needed by the animal or person.
Stem cells are remarkable because of the ability to keep renewing themselves through cell division even after long periods of inactivity, sometimes. Under certain conditions these cells can be induced to become specific parts for a body such as organ specific tissues or tissue. This happens regularly in our bone marrow where cells are dividing regularly to replace and repair wear and tear. However, as J Kevin Kaufman points out, some organs only have stem cells which divide to become new functioning cells for that organ under special conditions, for example the heart and brain.
So the three properties which make stem cells unique are their ability to renew and divide for extended periods of time, unspecialized, and capable of turning into other specialized cell types.
Different Kinds of Stem Cells
There are different kinds of stem cells, but for the most part a majority of stem cell research has been conducted using embryonic stem cells. The other kind of stem cell is called the “somatic or “adult” stem cell. In 1981 scientists learned to extract embryo stem cells from mice. After 17 years of research, scientists learned how to derive human embryonic stem cells. The human embryonic stem cells were created from in vitro fertilization and were only used for research when they were no longer needed and donors gave consent.
Fortunately, scientists had a breakthrough in 2006 when they discovered somatic stem cells could be engineered to genetically assume a stem cell-like state; these cells are called induced pluripotent stem cells (iPSCs).
Embryos which are 3-5 days old are called blastocyst and it is within these which embryonic stem cells generate the entire body of an organism. This early period of pregnancy is when the stem cells are induced into generating the many different special cells needed for vital organs and skeletal structure for the organism, such as the lungs, heart, skin, bones and so on.
Be sure to check back soon as we begin discussing the cell based therapies for treating diseases and the discoveries unveiled from research on stem cells.