March 2019

Stem Cells – What Are They and What are the Different Types?

A stem cell is categorized as “a cell with a unique ability to develop into specialized cell types in the human body."[1] The function of stem cells in the body is to supply new cells for the body as it grows and to replace specialized cells that have been lost or damaged.[2] Stem cells are assigned these responsibilities because they are able to replicate numerous times over to create new cells, and as they replicate themselves, they are able to morph into other types of cells that reside in the human body.[3]

The term “stem cell” was coined by Russian histologist, Alexander Masimov in 1908 when he discovered that all blood cells developed from a common precursor cell.[4] Since then, scientists and researchers worldwide have taken to studying stem cells in both flora and fauna in order to find treatments and cures for injuries and diseases as well as to gain more knowledge and insight into cellular biology.[5] Stem cells are highly important in the relatively new medical field of regenerative medicine.

Stem cells originate from two sources: adult body tissue and embryos, and each possess a different function.[6]

 


Embryonic Stem Cells

Embryonic stem cells provide cells for an embryo as it develops into a fetus and then a baby.[7] These stem cells are called “pluripotent”, which means that they are able to morph into any cell in the body.[8] With the correct stimulation, embryonic stem cells are able to transform into blood cells, skin cells and other cells a body requires, which is why these type of cells are harvested and used for IVF treatments.[9]

Adult Stem Cells

Throughout an individual’s life, their body houses and produces stem cells, allowing them to be used when necessary.[10] Also known as tissue-specific or somatic stem cells, these cells exist in a non-specific state but are still more specialized its embryonic stem cell counterpart.[11] Adult stem cells can be found in different types of tissues including, the brain, bone marrow, blood and blood vessels, skeletal muscles, skin and the liver but they can be difficult to detect as they remain non-specific until they are summoned by the body to repair or grow new tissue.[12] Adult stems cells are a reason why we are able to regenerate skin over an open wound and why the liver is able to regenerate itself after it has been damaged.[13]

 


A third type of stem cell, which are created by scientists in a laboratory is called induced pluripotent stem cells. Also known as iPS cells, they are created by harvesting normal adult cells such as skin or blood cells and “reprogramming” them into stem cells, to be used as needed.[14]

In conclusion, stem cells are extraordinary cells that have multiple purposes, as they can replicate itself to provide or replace a myriad of different cells needed in the human body. These cells are vital in the medical field of regenerative medicine as they enable and encourage researchers and scientists to look for solutions to injuries and diseases that currently have limited or no treatments or cures.

 

Sources:


[1] ‘What is a Stem Cell?’, in yourgenome.org – Facts; In the Cell, last updated August 17th, 2017, viewed on January 27th, 2019, https://www.yourgenome.org/facts/what-is-a-stem-cell

[2] ibid

[3] ibid

[4] Rojas, Yenny, ‘The History of Stem Cell Treatment’, in National Stem Cell Centers – Heal & Renew, published December 29th, 2017, viewed on January 27th, 2019, https://www.nationalstemcellcenters.com/2017/12/29/history-stem-cell-tre...

[5] ibid

[6] Brazier, Yvette, reviewed by Murrell, Daniel, MD, ‘What are Stem Cells and What Do They Do?’, in Medical News Today, last reviewed Monday, October 15th, 2018, viewed on January 27th, 2019, https://www.medicalnewstoday.com/articles/323343.php

[8] ibid

[10] ibid

[11] ibid

[12] Brazier, Yvette, reviewed by Murrell, Daniel, MD, ‘What are Stem Cells and What Do They Do?’, in Medical News Today, last reviewed Monday, October 15th, 2018, viewed on January 27th, 2019, https://www.medicalnewstoday.com/articles/323343.php

[13] ibid

[14] ‘What is a Stem Cell?’, in yourgenome.org – Facts; In the Cell, last updated August 17th, 2017, viewed on January 27th, 2019, https://www.yourgenome.org/facts/what-is-a-stem-cell