STEM cells have important characteristics that distinguish them from other cell types.
They are unspecialized cells that can develop into other specialized cell types in the body, like heart muscle cells, blood cells or nerve cells. Unlike these specialized cells, stem cells can replicate themselves many times over through cell division.
Under certain physiologic and experimental conditions, stem cells can be induced to transform into cells with special functions (i.e. beating cells of heart muscle, insulin-producing cells of the pancreas). As a sort of repair system of the body, stem cells can theoretically reproduce without limit as long as the person or animal is alive. Upon division, a new stem cell can either remain a stem cell or become a specialized one.
There are two kinds of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells are derived from embryos developed from eggs that have been fertilized in an in vitro fertilization clinic, and not from those fertilized within a woman’s body.
On the other hand, adult stem cells can be found in organs and tissues, including the brain, bone marrow, blood vessels, skeletal muscles, skin and liver. In some instances, adult stem cells can generate replacements for cells that are lost through normal wear and tear, injury or disease.
The primary difference between the two: While embryonic stem cells can become all cell types of the body, adult stem cells are limited to becoming cell types of their tissue of origin.
For these unique properties, scientists are currently interested in the study of how stem cells may become the basis for treating diseases such as Parkinson’s disease, diabetes, heart disease, traumatic spinal cord injury, muscular dystrophy and vision and hearing loss, as well as for understanding birth defects in the future.
Source: Stem Cell Information: National Institutes of Health resource for stem cell research (http://stemcells.nih.gov/info)
Kate Pedroso, Inquirer Research