Stem Cells

Overview:

Stem cells are cells that can develop into different cell types and repair the human body. The use of stem cells in stem cell transplant, more commonly known as a bone marrow transplant, have the potential to treat many diseases in the future. However, stem cell research is fairly new, only having begun about 30 years ago which means many new discoveries are on the horizon. There are two main types of stem cells: embryonic stem cells and adult stem cells and both types provide their own complications which will be discussed later in this paper.

Embryonic Stem Cells:

Embryonic stem cells are harvested during the developmental stage of embryos at 3-5 days of development. This is prior to the time at which implantation would normally occur in the uterus. This type of stem cell is called a pluripotent stem cell that consists of 50-150 cells at harvest. Pluripotent stem cells are considered “master cells” because they can self-renew and develop into the three primary cell layers of the early embryo: the endoderm, the ectoderm, and the mesoderm. Therefore, these stem cells have the capacity to develop into all cells of the adult body. The use of embryonic stem cells can provide cures for cardiovascular diseases, spinal cord injury, Alzheimer’s, diabetes, and Parkinson’s. However, ethical issues arise when considering that a human life could be involved in its use. Opposers of using embryonic stem cells in science argue that since these embryos could have developed into a fetus and, eventually, a human being, they should not be harvested. As a result, it is illegal to research embryonic stem cells without parental consent within some countries, such as the US.

Embryonic stem cells can be harvested in two ways: somatic cell nuclear transfer (SCNT) or altered nuclear transfer (ANT). SCNT is the traditional way of harvesting stem cells and involves removing the inner cell mass, ultimately destroying the embryo. ANT may remove the ethical issues that come with harvesting embryonic stem cells because in this process, scientists genetically program the nucleus and prevent the cell from becoming an embryo in the first place. However, this DNA is still the same as any other stem cell. This circumvention is part of the reason why ANT is the preferred method for harvesting.

Adult Stem Cells:

Adult stem cells are the other main type of stem cells. Their primary functions are to maintain homeostasis and replace cells that are dead due to injury or disease. Fortunately, their use does not possess many ethical issues, but they cannot be scientifically grown for a long time and thus cannot be generated in large quantities. However, adult stem cells have a significantly lower chance of being rejected, as opposed to embryonic stem cells which makes them a better choice. Blood stem cells can be harvested directly from the donor’s bone marrow, but the first step is to isolate them. Isolating them involves separating them from the other pathogens in the blood. Removing bone marrow is a difficult and painful procedure and the patient commonly stays in the hospital for 1-2 days after the harvest. The doctor will give a local anesthetic and insert the needle into the patient’s back. However, since this procedure is risky, stem cells are commonly removed from the blood to minimize complications and pain.

Diseases That Stem Cells Can Treat:

Stargardt’s disease is caused by a genetic mutation that eventually leads to blindness. The mutation causes the retinal photoreceptor cells to degenerate. Since the energy transport is faulty the consequence occurs within the eyes. By replacing dead cells in the retina with functioning ones from stem cells, patients could treat Stargardt’s. Diabetes can also be treated with stem cells. If the non-functioning islet cells (which produce insulin), are replaced with stem cells that can,, Type 1 diabetes can be treated. By placing stem cells that can produce insulin in a human body that requires it,it is possible for the patient to go for years without needing an insulin shot. However, there is no cure to diabetes, and not much research on this process, as not many patients have had this procedure done, as it can cause lots of complications. Stem cell transplants are being tested to treat other diseases like heart failure. Heart failure is a common issue in America among the older population and if doctors proceed with research, it is possible to reduce the number of deaths from heart complications in the future.

References:

1. Stanford Children's Health. (n.d.). What are stem cells? https://www.stanfordchildrens.org/en/topic/default?id=what-are-stem-cells-160-38

2. Mayo Clinic. (2019, June 08). Frequently asked questions about stem cell research. https://www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art-20048117

3. Types of stem cells. (n.d.). Closer look at stem cells. Retrieved October 11, 2020, from https://www.closerlookatstemcells.org/learn-about-stem-cells/types-of-stem-cells/

4. North East Knee and Joint Institute. (2019, January 18). The Truth About Stem Cell Therapy. https://nkjinstitute.com/the-truth-about-stem-cell-therapy/