Many of us either know someone or potentially are someone who is affected by an injury or trauma to the brain. Whether it be a concussion from playing sports, disease or illness that damages the brain, or a severe injury that causes lasting, devastating, problems. Those of us affected by these traumatic brain injuries (TBIs) are all somewhat aware of the hardships and troubles that come with brain damage. Consequences of TBIs can range from loss of comprehension in reading to more severe cases such as coma-like symptoms or chronic debilitations to mental capacity (Chen et. al 2016). Although the vast majority of people are affected by TBIs, many of us do not know what current treatment methods look like or how those methods of treatment work. Within the domain of TBIs and their treatment, a rising method of treatment has been the use of stem cell therapy. For the past couple of decades, the benefits of stem cell research have been questioned and evaluated, and the general consensus is as such: the future of treatment for victims of TBIs remains in and is contingent on the use/furthering of stem cell therapy. Two proponents of this statement are Dr. Nicole M. Weston and Dr. Dong Sun of Virginia Commonwealth University. In their review “The Potential of Stem Cells in Treatment of Traumatic Brain Injury,” they have found, through review and evaluation of many different primary research articles, that stem cell therapy of TBIs takes many forms and techniques, but in general prove to be supremely useful in treating patients. These two, along with many other researchers in the past few decades, have devoted time and energy to understanding how this devastating problem could potentially be erased with useful research and testing.
Drs. Weston and Sun work specifically at the Department of Anatomy and Neurobiology at the University’s School of Medicine. Their review was published in January of 2018 in an editorial named Current Neurology and Neuroscience Reports. Their goal was to see if advancing stem cell techniques can aid in neuroregeneration, the main issue that has to be dealt with when treating TBIs. They found that neuroregeneration can be aided via stem cell treatment in two main methods: 1) manipulating and controlling endogenous (natural to the victim/host body) neural stem cells or 2) transplanting/grafting exogenous (foreign/donor) stem cells to the area of interest. Both of these methods are used to achieve the goal of repairing and regenerating the brain (Weston and Sun 2018). The importance and relevance of that goal have long been emphasized in the medical world, as treatments in the past aside from stem cell therapy could barely make any progress in aiding the victim and reducing the effects of the TBI. What stem cell research has allowed researchers to accomplish would be one of the largest steps in medical science, and a key step in understanding the development of our own cells/bodies. Drs. Weston and Sun also addressed their concern for the growing cases around the world of TBI mortalities and the lack of thorough testing. Herein lies their larger, more morally-based motive for evaluating the past couple of decades worth of research.
Their research relies on a few key concepts: TBIs (and their consequences), stem cells, and neural regeneration. TBIs, as previously explained are injuries or traumas inflicted on the brain that can cause both short and long-term cognitive issues. They can come in many different forms like concussions or strokes and are generally well-known by the public due to the high chance that someone either has been affected or knows someone who is affected by TBIs. They affect the sensory-motor tissue in the brain that deals with controlling our perception and reaction to those perceptions and affects our ability to retain and recall memories (Spalding et al 2013). While most current therapies focus on secondary injuries, cutting-edge research looks to the root of the problem: neural regeneration. This is where stem cells come into play. Stem cells come in many different forms, from different places, and are utilized in many ways. The variability of stem cells is addressed by the researchers and the different kinds are explained. The different kinds of stem cell therapies can first be split up into two categories: endogenous SCs and exogenous SCs (Weston and Sun 2018).
Endogenous SCs, or adult neural stem cells (NSCs) are stem cells that reside in certain regions of the brain and create new neurons naturally as our bodies develop and age. The development of these new neurons by NSCs is generally well understood, which is why scientists are trying to manipulate these NSCs. A region of the brain called the olfactory bulb works with NSCs to replace old neurons with new ones in 3 main steps: creating the new neurons, moving the neurons, and integrating the neurons. When TBIs occur, this process can be affected/inhibited which leads to problems in creating new neurons (Spalding et al. 2013). Scientists look to modulate NSCs to help regenerate damaged tissue. Weston and Sun note that many different studies were done on both humans and mice (and various other animals) indicate potential in the manipulation of NSCs in order to make therapies for injured tissue in the brain. One of their noted studies that back up this claim includes one conducted in 2013 about the inner workings of natural neuron creation in adults (Spalding et al. 2013). They then talk about the main methods of changing these NSCs. One is a biochemical approach where growth factors are used to stimulate damaged NSCs to improve the survival of new neurons. This approach has been aided by many pharmacological groups around the world who have developed FDA-approved drugs that also stimulate NSCs (Weston and Sun 2018).
The other method of treatment was using exogenous SCs. This relies on harvesting SCs from other sources outside of the victim’s body. Exogenous SCs rely on the principle of introducing SCs that will replace the lost neural tissue and recreate or uphold the brain’s support system. These sources are most often embryonic stem cells, adult-derived NSCs, induced pluripotent stem cells, and mesenchymal stromal cells. While the names are a bit confusing, they all are named from where they come from. The most common exogenous SCs are embryonic which are harvested from embryonic or fetal brains. They are the most used because they differentiate easier and transform into neural tissue that matches the victim very easily compared to other exogenous SCs. They also have shown better rates of survival compared to other SCs long after they have been grafted, making them the prime candidate for this kind of therapy. The other types of stem cells include adult NSCs (like mentioned in the previous paragraph, but this time transplanted into someone else), induced pluripotent SCs (SCs that come from normal cells in our body), and mesenchymal stromal cells (SCs that come from bone marrow). These exogenous SCs are following the same principle but are a bit more ethically charged than endogenous SCs, especially embryonic SCs (Weston and Sun 2018).
The ethics of stem cell research is one of the biggest issues regarding stem cell research, as it has become intertwined with political stances. The ethical argument about harvesting stem cells from fetuses or embryonic donors is an important discussion as it relates to the limits scientists should consider from a scientific standpoint and moral standpoint. Does the fetus/embryo have a right to those cells? Is harvesting those cells the same as harming the embryo, or even as far as murdering the embryo by removing its method of development? Do scientists have a right to affect the development of embryos at all? These are all important questions that affect the scope of SC research. While the authors did not do any actual harvesting or stem cell manipulation themselves, they addressed this topic as an important one and talked about how some of the different trials they evaluated addressed that issue. While many different responses were recorded, the majority of researchers mainly propagated that the harvesting of stem cells is a delicate but necessary process to furthering treatment methods (Weston and Sun 2018).
If this kind of research interests you, another article published by Gao et al. in 2020 related to this one deals with how SCs can be used to treat spinal cord injuries (SCIs). That article also evaluates past research on SC therapy, but now for spinal cord injuries, and comes to a similar conclusion that continued use and development of SC therapy is the future of SCI treatments. That article details not just the methods for SC therapy but also the safety of those methods, and some methods not mentioned by Weston and Sun, like biomaterials, optogenetics, and more. This article is not only another great source of information about SCs but provides great support for the use of SCs in the future. It also backs up the claims provided by Weston and Sun while making the reader think about the possibility for SC therapy throughout the whole body.
In general, the study was very well conducted and Weston and Sun look into more than 130 different resources to build this guide to stem cell research. Their work was thorough and well documented and maintains a balance between generalizing topics and using specific studies to back up their claims. Their work is important for spreading awareness and understanding of TBIs. The common person can get lost in the intricate medical language relating to TBIs and SCs but works like this that simplify the current status of SC therapy can help people to better their own experiences with TBIs. This article could possibly help someone address their doctor about an issue they are having or help someone else who might be affected by a TBI. The article could also be a guide to a trained and professional researcher who wants to look more into the global problem that is TBIs. In this way, articles like this that summarize and provide analyses of years of research are crucial to the furthering of research.
Chen L, Zhang G, Khan AA, Guo X, Gu Y. 2016 Aug 31. Clinical efficacy and meta-analysis of stem cell therapies for patients with brain ischemia. Stem Cells International. doi:https://doi.org/10.1155/2016/6129579. [accessed 2021 Feb 8]. https://www.hindawi.com/journals/sci/2016/6129579/.
Gao L, Peng Y, Xu W, He P, Li T, Lu X, Chen G. 2020 Nov 5. Progress in stem cell therapy for spinal cord injury. Stem Cells International. doi:https://doi.org/10.1155/2020/2853650. [accessed 2021 Feb 8]. https://www.hindawi.com/journals/sci/2020/2853650/.
Spalding KL, Bergmann O, Alkass K, Bernard S, Salehpour M, Huttner HB, Boström E, Westerlund I, Vial C, Buchholz BA, et al. 2013. Dynamics of Hippocampal Neurogenesis in Adult Humans. Cell. 153(6):1219–1227. doi:10.1016/j.cell.2013.05.002. [accessed 2021 Feb 12]
Weston NM, Sun D. 2018 Jan 25. The Potential of Stem Cells in Treatment of Traumatic Brain Injury. Curr Neurol Neurosci Rep. 18(1):1. doi:10.1007/s11910-018-0812-z. [accessed 2021 Feb 8] https://link.springer.com/article/10.1007/s11910-018-0812-z
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