The Key to Regenerative Medicine

There are more than 123,000 people waiting to receive an organ transplant in the United States. In fact, the lack of available donors and organs for organ transplantations is a huge problem. Nearly 18 people die while waiting for an organ transplant every day, which amounts to nearly 6570 people a year (“25 Facts About”).  This is an enormous number of people waiting to receive an organ. But what if the waiting period were eliminated? Is this actually possible?

With the advent of regenerative medicine, which enables doctors to grow body parts in a laboratory environment, this may be possible. The process is dependent on stem cells, which are unspecialized cells that can give rise to specialized cells like neurons.  Stem cells possess two unique properties — self renewal and potency.  Self-renewal is the stem cell’s ability to create another stem cell, whereas potency refers to the capability of the cell to differentiate into specialized types of cells (“Stem Cell Basics”).

Research points to the use of stem cells as a replacement for organ transplants because stem cells act as an “internal repair system” in the body. The two properties of stem cells are the key to the possibility of regenerative medicine. The stem cells not only continuously replenish their own supply but also repair organ damage through differentiation. Embryonic stem cells, called totipotent and pluripotent, can become almost any type of cell and are thus the best choice for regenerative medicine. Adult stem cells can only become certain types of cells (“Stem Cell Basics”). While the use of embryonic stem cells elicits ethical debates, science has paved its way for further advances with the discovery of induced pluripotent stem cells (iPSCs), which are made by programming specialized body cells to become stem cells. It has been found that introducing four transcription factors — Klf4, c-Myc, SOX-2, and OCT4 —through retroviruses can reprogram a somatic cell to be a pluripotent stem cell.  Cellular reprogramming eliminates many of the sources of ethical dilemmas surrounding embryonic stem cells while at the same time creating induced pluripotent stem cells that possess equivalent capabilities of differentiation.

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Chokshi-IPSC
Induced pluripotent stem cells (iPSC) can be created from adult cells by reprogramming with certain genetic factors.

Stem cell research has come a long way, but does it help cure many diseases and regenerate organs? The answer is YES. Stem cells are used to investigate the embryonic development of humans, cure certain diseases such as cardiovascular diseases and diabetes, treat burn victims and test drugs. Stem cell differentiation in normal embryos allows scientists to determine abnormalities in the process that leads to birth defects. Induced pluripotent stem cells can be obtained from a patient to form replacement organs in vitro that can be transplanted into the patient, eliminating the long waiting lists and the chances of an immune rejection. For instance, skin is made from a patient’s somatic cells the same way as for internal organ transplants and is then put on top of burned skin in order to treat burn victims. In a similar way, certain diseases can be treated by replacing diseased cells in the body. For instance, cardiovascular diseases in which the cardiac tissue is damaged can be treated by using stem cells to regenerate the diseased tissue. Additionally, diabetes types I and II can be treated using stem cells by allowing them to differentiate into beta cells of the pancreas in order to replenish the beta cells destroyed by the autoimmune process (type I) or the beta cells that are failing (type II). These treatments, which used to require the presence of organ/tissue donors, can now be done using stem cells. The use of iPSCs also makes it possible to use cells with the same genetic material as the patient, minimizing chances of immune rejection for organ/tissue transplants.

Looking into the distant future, it can be said that the problems that are arising today because of the ever-growing waiting list for organs would cease to exist. People would be able to receive transplant organs made from iPSCs with the same genome. In fact, the world will be a very different place with the development of stem cell therapy and regenerative medicine. However, there are still many milestones left to be achieved before this will become a reality. In the meantime, it can be said that stem cells hold the potential to transform the world greatly just as they hold the potential to transform themselves into differentiated cells.

Sources

Murnaghan, Ian. “Benefits of Stem Cells.” Explore Stem Cells. N.p., 3 Oct. 2010. Web. 27 Jan. 2012. <http://www.explorestemcells.co.uk/benefitsofstemcells.html>.

“Stem Cell Basics.” Stem Cell Information. National Institute of Health, 2009. Web. 27 Jan. 2012. <http://stemcells.nih.gov/info/basics/basics1.asp>.

“25 Facts About Organ Donation and Transplantation.” National Kidney Foundation. N.p., 2012. Web. 27 Jan. 2012. <http://www.kidney.org/news/newsroom/fs_new/25factsorgdon&trans.cfm>.

About The Author

Aastha is a sophomore at Princeton planning to major in Molecular Biology. She is interested in pursuing certificates in Global Health and Health Policy as well as Quantitative and Computational Biology. She is very interested in healthcare related areas and plans on going to medical school. She likes writing about science news and research going on. She is part of several science and health related publications on campus in various positions. She is involved in research projects in the Princeton science departments for 2 years. She also participated in several science competitions. She is also a volunteer at the UMCPP.