Stem Cells Help Evaluate Experimental Alzheimer’s Drugs
Scientists have recently made significant discoveries about Alzheimer’s Disease, which has led to the development of new treatments and medications. Traditional drug trials typically use human subjects for testing, but this practice carries the risk of a patient developing unwanted side effects, some of which can be fatal. Some scientific studies use animal subjects before turning to humans, but physiological differences can make it difficult to predict which side effects may occur in humans. As an answer to these problems, scientists working on Alzheimer’s treatments have turned to stem cells, which can mimic the way that the drugs will affect people.
Why Not Use Human Subjects?
A common issue that occurs when developing new and experimental treatments for any drug is the inability to test on people. While many people may be willing to act as test subjects in the hopes of helping find a cure for their disease, it is considered unethical to do so. The U.S. National Library of Medicine, National Institutes of Health discusses why human subjects cannot be used for experimental treatments for Alzheimer’s Disease. “Although considerable effort has been expended developing drug candidates for Alzheimer disease, none have yet succeeded owing to the lack of efficacy or to safety concerns. One potential shortcoming of current approaches to Alzheimer disease drug discovery and development is that they rely primarily on transformed cell lines and animal models that substantially over-express wild-type or mutant proteins. It is possible that drug development failures thus far are caused in part by the limits of these approaches, which do not accurately reveal how drug candidates will behave in naive human neuronal cells.”
The Stem Cell Solution
Since there have not been effective animal models available for drug trials, scientists have begun using stem cells to research the effects of new treatments on human cells. Since these stem cells come from humans and can be “activated” to develop into whichever cells scientists wish to study, they are more indicative of what medications may do in the brains of actual Alzheimer’s patients.In addition to therapeutic applications, induced stem cells made from patients with AD and related disorders are helping shed light on disease mechanisms and enabling screens for potentially therapeutic compounds.” The California Institute of Regenerative Medicine is a lead provider of funding for Alzheimer’s Disease research. Its website explains some of the research taking place. “Some groups are trying to mature embryonic stem cells into a cell type that can be transplanted into the brain to replace cells that are destroyed in the disease. Others are simply using stem cells as a way of delivering factors that appear to protect brain cells. One team is trying to use stem cells to clear out the protein that builds up and clogs neurons in Alzheimer’s patients.”
One of the main problems involved in treating Alzheimer’s Disease is that many of the treatments available only treat symptoms. This is partly because the exact cause of the disease is not definitively known. Researchers at the Harvard Stem Cell Institute are utilizing stem cell research to learn more about the disease itself. They explain, “Harvard Stem Cell Institute (HSCI) scientists use a different set of tools to understand disease. With the advent of induced pluripotent stem cell technology — the biological reprogramming of mature cells into stem cells — it is possible to generate stem cells from the skin of an adult Alzheimer’s patient and then direct these cells to become different types of brain cells. HSCI investigators can direct patient stem cells to become brain cells both affected and not affected with Alzheimer’s disease. Our scientists plan to examine the types and amounts of Aß proteins generated by these cell types, and to look at how the different cell types respond to plaques.”
Stem cells offer scientists a better portrait of how their new treatments will affect human subjects without having to expose actual patients to potential side effects. They can also allow doctors to generate brain tissue that will allow them to better understand the causes of the disease, which could lead to more effective treatments. These new research methodologies could potentially change the way that this disease is diagnosed and treated, which is encouraging as more of the population enters their senior years.