Core Biology H/D Even
Conger, Krista. "Faulty Stem Cell Regulation May Contribute to Cognitive Deficits Associated with Down Syndrome, Study Suggests." Stanford Medicine. N.p.,11 Sept. 2013. Web. 27 Oct. 2013.
"Faulty Stem Cell Regulation May Contribute to Cognitive Deficits Associated with Down Syndrome, Study Suggests"
Recently, researchers at the Stanford University School of Medicine have discovered that the overexpression of a specific gene, known as Usp16, on chromosome 21 may be responsible for the cognitive issues exhibited by people with Down syndrome. The researchers, namely Michael Clarke, discovered this when they noticed defects in the stem cells of both the mice and human tissues they tested. Humans with Down syndrome usually have three copies of chromosome 21 and therefore multiple copies of the Usp16 gene that accelerate the uses of stem cells in early development. Therefore, by the time people with Down syndrome reach adult hood, they have overused their stem cell pools and tissue regeneration, making them vulnerable to early onset neurodegenerative diseases. This gene also makes it harder for the skin and neural progenitor cells in humans, which are the “self-renewing cellular factories responsible for the development and maintenance of many of the cell types in the brain,” to form neurospheres more slowly; this is compared to the study of Down syndrome cases whose Usp16 expression was lessened with drugs which in turn allowed for the skin and neural progenitor cells to develop at a normal rate. And so, the researchers in this study highlighted the fact that by reducing the expression of the Usp16 gene on chromosome 21, the cognitive function in humans with Down syndrome will be significantly improved, as it will balance their stem cell levels. They proved this through the results they obtained from two mice chains: Ts65Dn, who has three copies of Usp16, and Ts1Cje, who only has two copies of the gene; Ts65Dn is more closely related to the human symptoms of Down syndrome than Ts1Cje. The study found that the cells of Ts65Dn were less able to renew themselves through cell division than Ts1Cje, proving that subjects with less copies of the Usp16 gene were to able function more normally. The researchers used this information to suggest that by blocking the expression of one copy of the gene in human cells, it will improve the cognitive function in those affected.
This discovery has the potential to have a remarkable impact on the world, because it could allow for those with Down syndrome to enhance their intellectual and interactive skills. In the United States alone, 400,000 people have been diagnosed with Down syndrome, including another six million worldwide along with the families and loved ones of these people. This study is specifically significant because it is among the first to explain a possible explanation and solution for the poor cognitive skills in people with Down syndrome, since the physical health problems of the disorder, specifically involving the heart, are now able to be treated. In the future, it can potentially slow the aging of humans with this affliction, along with preventing early onset Alzheimer’s. On a larger scale, this study shows humans, whether or not they have Down syndrome, just how vital stem cell regeneration is to human cognitive and physical function. Also, if the therapies performed on the Ts65Dn mouse translates with similar, positive effects on humans, it has the capability to improve the quality of life of six million people throughout the world.
This article was successful in providing the medical and biological aspects of Down syndrome, along with formulating the results of the research of the study into a solution that the researchers believe will show cause and effect: by reducing the expression of the Usp16 gene, cognitive function in people with Down syndrome will improve. However, the study failed to indicate what specific drugs will be able to perform such a task, in addition to whether or not there were any negative side effects that the Ts65Dn mouse received from hiding the expression of one of its Usp16 genes. Therefore, the article would have made a stronger argument if it included any contradictory claims from other scientists who believe that ceasing the expression of a copy of a gene in a chromosome will have unforeseen negative impacts on the subject’s health, or whether or not other scientists have supported and agreed with the results of this study. This article only expresses the reports of the researchers working with the Stanford University School of Medicine, as well. All in all, the author of this article, Krista Conger, was able to synthesize the complex biological components of a complicated disorder into a concise explanation, making it able to be understood without being too simplistic. This is important because many people reading this article will be able to perceive the possibilities that the success of this study will offer to people living with Down syndrome.