Stem Cells Symptoms, Causes, Treatment - Why are stem cells important? on MedicineNet

Stem Cells (cont.)

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Why are stem cells important?

Stem cells represent an exciting area in medicine because of their potential to regenerate and repair damaged tissue. Some current therapies, such as bone marrow transplantation, already make use of stem cells and their potential for regeneration of damaged tissues. Other therapies are under investigation that involves transplanting stem cells into a damaged body part and directing them to grow and differentiate into healthy tissue.

What are the different types of stem cells?

Embryonic stem cells

During the early stages of embryonic development the cells remain relatively undifferentiated (immature) and appear to possess the ability to become, or differentiate, into almost any tissue within the body. For example, cells taken from one section of an embryo that might have become part of the eye can be transferred into another section of the embryo and could develop into blood, muscle, nerve, or liver cells.

Cells in the early embryonic stage are totipotent (see above) and can differentiate to become any type of body cell. After about seven days, the zygote forms a structure known as a blastocyst, which contains a mass of cells that eventually become the fetus, as well as trophoblastic tissue that eventually becomes the placenta. If cells are taken from the blastocyst at this stage, they are known as pluripotent, meaning that they have the capacity to become many different types of human cell. Cells at this stage are often referred to as blastocyst embryonic stem cells. When any type of embryonic stem cells are grown in culture in the laboratory, they can divide and grow indefinitely. These cells are then known as embryonic stem cell lines.