An explanation of stem cells and their potential to treat HD
What is a stem cell?
Most of the cells that make up the organs and tissues of the body are highly specialized for their specific jobs. The red blood cell, for example, is specifically crafted to carry oxygen from the lungs to the tissues. A comparison can be made with today’s society where most workers are trained to perform a specific trade. The days of the generic fix-it man are gone; instead, the electrician, the plumber, and the cable guy fill specific niches.
Likewise, in the human body, most cells are specialized for certain jobs. In fact, most cells lead very standard lives – they grow up, do the same job every day, and then eventually retire and pass away. These cells, such as nerve cells or skin cells, are called specialized cells. They are mature cells that have characteristic shapes and are committed to performing specific functions (See Figure 1). Once these cells have matured, they are usually incapable of reproducing themselves. They essentially remain “childless” for their whole lives.
If mature specialized cells cannot leave “children” behind when they die, how does your body make new cells? For example, when you cut your skin, how do you grow new skin cells? When you get blood drawn, how do you make new blood cells?
It turns out that stem cells solve this unique problem. A stem cell can reproduce itself over and over again (a special trick known as “self-renewal” or “self-replication”). With every replication, the stem cell produces one new stem cell and one new specialized cell. Stem cells can often give rise to a number of different cell types. For example, blood stem cells can produce both red blood cells and white blood cells. In this way, stem cells are not committed to produce a single cell type. Instead, a stem cell remains uncommitted until it receives a specific signal to divide and produce one of the various specialized cells.
In more formal terms, a stem cell is a special kind of cell that has the ability to divide for indefinite periods of time and to give rise to the mature, specialized cells that make up an organism. A stem cell is uncommitted and remains uncommitted until it receives a signal to differentiate (become a specialized cell). (See Figure 2).
Last Modified: 5-08-03
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