TYPES AND FUNCTIONS OF STEM CELLS

By: Andrew J. Rochman

Stem cells are considered to be a hot area of research because stem cells provide the prospect of developing cure for many diseases that are yet incurable, such as Alzheimer’s disease. Under the right conditions, stem cells have the ability or to develop or differentiate into different forms of cells.

There are many types of stems cells. They are classified into:

·        - Embryonic stem cells

·        - Tissue stem cells

·        - Induced pluripotent stem cells

Embryonic stem cells (ESCs)

Embryonic stem cells or ESCs are extracted from embryos at a very early stage (3 to 5 days old) and grown in the laboratory by taking consent of the donor providing them with the right conditions. The advantages of ESCs are that they can differentiate into any kind of cell and possess the ability to multiply without defects, so that large supplies can be made for research purposes (Mayoclinic.org, 2014).

ESCs are being used in clinical trials to treat eye disorders. In more recent study, ESCs were used to treat heart failure in pregnant mothers. The study suggested that ailing heart of a pregnant mother sends out a distress signal that was received by ESCs of the unborn baby, which were able to reach the distress site and differentiate into heart cells (Zimmer, 2014).

Tissue Stems Cells (TSCs)

Tissue stem cells (TSCs) are stem cells from various tissues of the body that are involved in regeneration and repair of tissues. They can only differentiate into the type of tissue in which they are present.  These include:

Skin Stem Cells

Skin stem cells have been grown in the lab since the 1980s to develop skin grafts for severe burn patients. However, this type of skin is far from perfect as no hair, sebaceous glands or sweat glands are present. It is commonly used to treat patients with third degree burns on a large area of their body (EuroStemCell, 2014).

Blood Stem Cells

Blood stem cells are commonly used in bone marrow transplants to provide patients with a new supply of blood cells.  However, there is a risk of recipient’s body attacking cell from the donor’s body. This results in graft-versus-host disease (GVHD) (EuroStemCell, 2014).

Umbilical Cord Stem Cells

Umbilical cord stem cells are extracted from the umbilical cord and are used to make different types of blood cells. They are being used in research to understand the working of blood cells. They are also used for treating leukemia in young children (EuroStemCell, 2014).

Mesenchymal Stem Cells (MSCs)

MSCs are found in the bone marrow and make cells of different types such as that of cartilage, bone and fat. MSCs also support blood cell formation in the body. MSCs are being studied to understand how these cells play a role in maintaining and repairing tissues.   Some clinical trials are underway that are investigating how MSCs help to repair bone or cartilage or even blood vessels. It appears that MSCs may have an indirect role in the repair mechanism of blood vessels (EuroStemCell, 2014).

Induced Pluripotent Stem Cells (iPSCs)

Induced pluripotent Stem Cells (iPSCs) are adult stem cells that have been reprogrammed to behave like embryonic stem cells. These stem cells can then be used instead of embryonic stem cells for treatment, thereby eliminating risk of immune rejection. They have been used in research to make new heart cell by reprogramming adult connective tissue cells (Mayoclinic.org, 2014)..  

 

References

Stem cell research & therapy: types of stem cells and their current uses. [online] Available at: http://www.eurostemcell.org/factsheet/stem-cell-research-therapy-types-stem-cells-and-their-current-uses

Mayoclinic.org, (2014). Stem cells: What they are and what they do - Mayo Clinic. [online] Available at: http://www.mayoclinic.org/tests-procedures/stem-cell-transplant/in-depth/stem-cells/art-20048117?pg=1

What are the major types of stem cells? (2007). Nature Reports Stem Cells. [online] Available at: http://www.nature.com/stemcells/2007/0706/070614/full/stemcells.2007.14.html

Zimmer, M. (2014). Mending Broken Hearts: Using Embryonic Stem Cells to Repair the Damage Caused by Heart Attacks. [online] The Huffington Post. Available at: http://www.huffingtonpost.com/marc-zimmer/mending-broken-hearts-usi_b_5269288.html