Stem Cells Tested on Mice with Alzheimer’s Disease

Researchers test stem cells on mice with Alzheimer’s Disease

Stem Cells Tested on Mice with Alzheimer’s Disease

In a mouse model of Alzheimer’s disease, amyloid beta clusters (red) build up among neurons (green) in a memory-related area of the brain. Credit: Strittmatter Laboratory, Yale University Photo/Adam Kaufman

Researchers at the University of Michigan (UM) are testing the effectiveness of transplanted stem cells on mice with Alzheimer’s Disease (AD). After implanting human neural stem cells into the brains of affected mice, they saw improvement in recognition, spatial memory and learning.1

The research team, led by Dr. Eva Feldman, reported its results in an article published in Nature earlier this year. UM scientists completed a proof-of-concept study using mice with genes that mimic AD. In the study, they transplanted human neural stem cells into the fimbria fornix. This region of the brain serves the hippocampus.

At 4 weeks and 16 weeks post-transplant, scientists observed significant changes in cognition for two hippocampus-centered tasks. Scientists believe the hippocampus controls emotion, memory and the autonomic nervous system. The team also noted that the test mice showed a marked decrease in their amyloid plaque load. Further, the researchers found that the transplanted stem cells did not trigger a significant immune system reaction. The results of the study suggest that stem cell transplantation could potentially provide therapeutic treatment for AD.

The results also suggest that the transplanted stem cells aren’t replacing neurons lost or damaged by the disease. Instead, they believe that the cells are magnifying and supporting the body’s natural immune response to the disease. This is important, not only for its effect, but also because it sheds some additional light on a potential cause.

What is Alzheimer’s Disease?

AD is the leading cause of dementia in the United States. Currently, about 5 million people have the disease and doctors expect this number to grow. Doctors are not sure of what causes the condition, and do not have effective treatments for it. They believe that some factors including age, heredity and other health conditions can influence the disease’s onset. While some drugs can slow the progress of the characteristic AD dementia, they cannot stop the disease itself.

According to the Centers for Disease Control, AD patients initially show symptoms of mild memory loss. Over time, the disease progresses and can impair memory, thought processes and language. In addition, AD patients may lose the ability to interact with and understand their environment. In later stages, AD patients are unable to care for themselves and perform simple activities of daily life.

Early on, doctors could only confirm an AD diagnosis after death. Today, many new imaging techniques can show the deterioration that takes place in the brain of an Alzheimer’s patient. One characteristic of the disease is the build-up of tau proteins and amyloid plaques in the brain. Researchers don’t know whether the build-up of these substances is a symptom or the cause of AD. The findings are important because they show that these changes take place long before symptoms of the disease appear.

Normally, symptoms of AD appear after age 60, however early-onset forms of the disease do exist. Without effective treatments, the number of people living with the disease doubles every 5 years beyond age 65.2 Scientists expect to see the affected population increase to 14 million by 2060. AD is also the 6th leading cause of death among adults in the US.

How can stem cells combat Alzheimer’s Disease?

Scientists have conducted an enormous amount of research to find the cause of the disease and evaluate potential treatments. Unfortunately, the disease is likely the result of many factors, which tends to complicate the research. While researchers have conducted many human trials, most have not proven to be effective. No new treatments for AD have been introduced in 15 years.

While the UM study results are encouraging, additional stems are needed before human clinical trials. Feldman’s team recently received a grant from the National Institute on aging to continue animal studies. The next step will be to conduct similar research on larger animals that are more like human beings. Additionally, the team must evaluate the long-term effect of stem cell transplants on animal subjects. Long-term observation of test animals can show whether stem cell treatment may produce unwanted side effects. If large animal studies show serious promise, Feldman believes that a human clinical trial could be 3-5 years away.

The scientists say that the study is a small step forward in advancing their knowledge about the disease. Further research in to the causes of AD may eventually lead to meaningful stem-cell and other interventions and treatments. Overall, this and other research helps show the potential power of stem cell-based therapies. If you would like more information about banking human stem cells for future research or treatment, or the work of the National Dental Pulp Laboratory, please visit our website or call us at (774) 843-2984.