WHY ARE STEM CELLS IMPORTANT?

Stem cells have three important characteristic that distinguish them from other cells:

Stem Cell

1. They are nonspecializing cells that renew themselves for long periods through cell division. They do not have any tissue-specific functions that allow them to perform specialized functions. For example. a single stem cell cannot beat with another heart cell: it cannot communicate with other cells, as nerves cells do.

2. Under certain conditions stem cells can be induced to become cells with special functions, such as cells of the heart muscle or insulin-producing cells of the pancreas. Unlike muscle, blood, or nerve cells, they can replicate themselves many times—a process called proliferation. A starting line of stern cells can proliferate

in the laboratory for many months and yield millions of cells. If this happens over a long period of time, the process is called self-renewal.

3. Stem cells give rise to specialized cells. When this occurs, the process is called differentiation. Signals from both inside and outside the cell may trigger this differentiation. Genes control the internal signals. External signals include chemicals secreted by other cells, physical contact with other cells, and certain molecules called growth factor

   A future is envisioned in which stem cells may be used in treating diseases such as Parkinson’s disease, diabetes, and heart disease. Such cell-based therapies form the basis of a new ficld—regenerathe or reparative medicine, in addition, these therapies may be used for screening new drugs and understanding birth defects.