Can embryonic stem cells be used to treat neurodegenerative diseases such as Parkinson's disease

Parkinson’s disease is a neurodegenerative disease that affects the patient’s ability to control their movement (PDF, n.d.). The disease is a progressive and chronic one, meaning its symptoms will worsen over time and so far cannot be cured. Its cause is the bundling or misfolding of certain proteins in brain cells leading to the neurons not being able to transmit enough dopamine (Harvard University, 2017) (see Figure 1). Once diagnosed with the disease, so far the only treatment option is the treating of the patients’ symptoms with medication or even surgery once the disease progresses. The symptoms include tremor of the limbs, jaw and face, bradykinesia, rigidity, postural instability, dementia, etc. (PDF, n.d.) and therefore has an immense impact on the living conditions of those affected. Additionally, it is a very widespread problem with up to 1 million people diagnosed merely in the U.S. ("Statistics of Parkinson's," n.d.)

Stem-Cell Medicine could form a new way of treatment for those affected with Parkinson’s leading to them having a higher quality lifestyle again. By injecting neurons that are made from embryonic stem (ES) cells into the patient's brain, it is plausible that the patient will then regain their ability to control their movement as well as alleviate all the other symptoms of Parkinson’s. In order to create neuron cells from ES cells they have to go through a specific process called differentiation in which they are put into special conditions, specific to creating DA neurons and left to breed and incubate in said environment (Björklund, Sanchez-Pernoté, Chung, Andersson, & Ying Ching Cheng, 2002). This will cause the cells to differentiate into neurons can then transmit a healthy amount of dopamine (see Figure 2). Once this process has been completed the cells will be inserted into the patient’s brain through several injections at different points. From this point onwards the newly ejected neurons will work inside of the brain. Therefore, the brain will be able to to again transmit the dopamine that was not transmitted before, regulating the disease and its symptoms. The benefits of such a treatment would be that the cells retain pluripotency after having been multiplied in a test tube (Politis & Lindvall, 2012) as well as the fact that in several studies that had been done on primates researches have already found that the treatment alleviates the symptoms of Parkinson’s up to a very long time (Colen, 2015). However, there are some serious limitations to this method one of them being that it increases the risk of tumor formation in the brain (Politis & Lindvall, 2012). Additionally, the injection of the DA-neurons into the patient’s brain is a hard and complicated procedure with many risks that could include brain damage since the needle has to pass the brain several times (Brown, 2016).

Figure 2: Diagram of steps of differentiation of ES cell to DA neuron (Shen, Huang, Liu, Han, & Xu, 2016).

Another factor that could risk this treatment to be used clinically is the ethical dilemma surrounding ES cells. On one hand, using this new discovery could alleviate the suffering and potential death of millions. With using embryonic stem cells doctors could highly improve the living conditions of the affected patients and prevent them from facing serious repercussions that could even lead to death. Some might see it as our duty to help the people who are in need of our help when we get the chance to. On the other hand, in order to do so others have reason to say that it would cause the destruction of an unborn child. The embryonic stem cells that are needed to alleviate Parkinson’s disease are primarily made from cells found in human blastula which is considered one of the earliest stages of life. Therefore, some people consider using these cells and causing the destruction of the blastula is to be considered destroying an unborn child. Thus, this creates a moral dilemma between feeling the need to alleviate the patient's pain and respecting the value of human life ("Embryonic Stem," 2015)

When considering the economical factor surrounding this topic, there are two sides to this. One of them being that the intensive research that is going into finding these treatments and putting them to use is opening new workplaces in labs and is therefore boosting the economy. The other side of the argument is that the money that goes into funding this research could be spent on other topics that might benefit the economy more such as the general job market or the country’s education. Particularly since the money spent on this research is such a vast amount, with the NIH spending 1.5 billion dollars a year (Hildreth, 2016) on this research, which could be used differently to directly benefit the economy.

To conclude, whilst the treatments that have already been developed seem promising, it will still take years of research and perfecting the techniques used, until it could potentially be used clinically. Furthermore, the ethical dilemma surrounding this treatment will persist to be a problem in my opinion, which could sadly highly risk the future of this project. Finding the cure to Parkinson’s disease with its appalling symptoms is and will persist to be an important part of medicine, with stem cells leading the way.

References

Björklund, L. M., Sanchez-Pernoté, R., Chung, S., Andersson, T., & Ying Ching Cheng, I. (2002, January 8). Embryonic stem cells develop into functional dopaminergic neurons after transplantation in a Parkinson rat model. Retrieved from US National Library of Medicine database.

Brown, J. (2014, June 5). Harvard researchers see promise in transplanted fetal stem cells for Parkinson's. Retrieved from https://hsci.harvard.edu/news/harvard-researchers-see-promise-transplanted-fetal-stem- cells-parkinsons

Brown, R. (2016, September 14). Stem cells successfully injected into Parkinson's disease patient, in trial treatment. Retrieved from http://www.abc.net.au/news/2016-09-14/parkinsons-disease-trial-injects-stem- cells-into-brain/7844674

Colen, B. D. (2015, March 3). Possible progress against Parkinson’s. Retrieved from https://hsci.harvard.edu/news/possible-progress-against-parkinson%E2%80%99s

Embryonic stem cell research: An ethical dilemma. (2015, November 5). Retrieved from http://www.eurostemcell.org/embryonic-stem-cell-research-ethical-dilemma

Harvard University. (2017, January 25). New understanding of Parkinson's disease. Retrieved from http://hsci.harvard.edu/news/new-understanding-parkinsons-disease

Hildreth, C. (2016, September 20). How Many Billions Are Spent on Stem Cell Funding? (NIH Spends $1.5B/Year). Retrieved from https://www.bioinformant.com/stem-cell-funding/

[Neurons in a normal and a Parkinson's patient]. (n.d.). Retrieved from https://www.atrainceu.com/course- module/2441043-143_parkinsons-module-02

PDF. (n.d.). What is Parkinson’s Disease? Retrieved from http://www.pdf.org/about_pd

Politis, M., & Lindvall, O. (2012, January 4). Clinical application of stem cell therapy in Parkinson's disease. Retrieved from https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-10-1#Tab1

Shen, Y., Huang, J., Liu, L., Han, C., & Xu, X. (2016, May 31). A Compendium of Preparation and Application of Stem Cells in Parkinson's Disease: Current Status and Future Prospects. Retrieved from US National Library of Medicine database.

Statistics of Parkinson's Disease (PD). (n.d.). Retrieved from https://www.floridahospital.com/parkinsons- disease-pd/statistics-parkinsons-disease-pd