Author: Isabel Zhang
From: Chicago, IL, US
Introduction
Imagine your body as a factory. Every cell is like a factory worker: they are each assigned their own special role in maintaining your body’s function. Nerve cells send signals, skin cells form protective layers, and muscle cells contract. A nerve cell cannot do a muscle cell’s job, and reversed likewise, because they each have a specific size and structure determined during the embryo stage that cannot be changed.
However, researchers have made a major discovery that defies this rule: stem cells!
The Shape-Shifting Stem Cell
Stem cells are unique from other cells in that they are unspecialized (they don’t have special roles like nerve cells, muscle cells, skin cells, etc.), but are capable of becoming specialized cells. They are the foundation for plant, animal and human development. In humans, there are two main types of stem cells: embryonic and adult.
Embryonic stem cells exist only at the earliest stages of development, and are found in embryos (thus the name) that are 3-5 years old. They are pluripotent, meaning they can develop into ANY type of cell; nerve cells, red blood cells, cartilage cells, you name it.
Adult stem cells on the other hand form during fetal development and stay throughout life, and are found in tissues such as bone marrow. They are multipotent, so they can still develop into many types of cells, but not every type like embryonic stem cells can.
In addition to their ability to become specialized cells, stem cells can self-renew, or divide to make copies of themselves. Thus, our bodies use them to replace worn-out cells when they die. For example, the cells that form the lining of our intestines get worn-out every four days. So stem cells underneath the lining replace those cells as they die.
Why Stem Cells Are So Useful
Doctors and researchers are so interested in stem cells because they could be used in so many different areas of health and medical research. They hope that studying stem cells could help:
Reveal how serious diseases come about. Researchers are trying to better understand the genetic and molecular signals in stem cells that lead to them becoming organ/tissue-specific cells (bone cells, heart muscle cells, nerve cells, etc.). Gaining such an understanding could help researchers identify what component of stem cell processes goes wrong to cause certain diseases and conditions, and possibly allow them to find ways to inhibit those diseases/conditions from forming!
Treat conditions or diseases by repairing damaged tissue in people (stem cell therapy). For example, scientists currently use stem cells to treat leukemia, a form of cancer that affects your bone marrow. With leukemia, some of the cells inside the bone marrow grow uncontrollably and crowd out the important stem cells that form the blood cells. Here’s where stem cell therapy comes into play: leukemia patients can get a stem cell transplant, where they recieve healthy stem cells that form the much-needed blood cells. Amazing, right?
Test if new drugs are ready to be used. Before trying them on people, researchers can test them on stem cells for safety and effectiveness. Recently, researchers have been trying to program stem cells into tissue-specific cells to test new drugs. For example, if they created a new drug that addresses a nerve disease and wanted to test it, they could program stem cells into nerve cells to be used for the test! If researchers can find a way to accurately program cells into specific cells, we wouldn’t have to put people at risk if a new drug is toxic.
Conclusion
With all the amazing discoveries and innovations we’ve made with stem cells, it’s no wonder that researchers are striving to advance the knowledge on stem cells and expand their applications in health and medicine. Our perceptions of conditions and diseases as once mysterious and unsolvable are now changed- all thanks to the amazing stem cell!
About the Author: Isabel Zhang
Isabel is a senior in high school, and is interested in biology and engineering. In her free time, she loves to bake, sketch, and hang out with her family.
References
Stem Cells. (2020, May 21). Retrieved from https://medlineplus.gov/stemcells.html#:~:text=Stem cells are cells with,cells and adult stem cells.
M. (2019, June 08). Stem cells: What they are and what they do. Retrieved from https://www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art-20048117
Stem Cell Basics. (n.d.). Retrieved from https://www.closerlookatstemcells.org/learn-about-stem-cells/stem-cell-basics/
Very interesting topic! I wonder if we can heal heart or brain tissue with these cells.