Alzheimer's Disease

 

What is Alzheimer's Disease?

 

Alzheimer’s disease accounts for 60% to 70% of cases of dementia. Approximately 35 million people worldwide have Alzheimer’s disease today and well over 100 million people could be affected by 2050. It is a chronic neurodegenerative disease that usually starts slowly and gets worse over time. The first signs of Alzheimer’s often include lapses in memory or struggling to find the right words. Over time, symptoms such as confusion, mood swings or memory loss develop and become increasingly severe.

 

What causes it?

 

The cause of the disease is still unclear, but researchers have found that people affected by Alzheimer’s have an abnormal build-up of certain proteins in the brain. One of these proteins, called amyloid beta, clumps together to form ‘plaques’.  Another, known as tau, gets twisted into protein ‘tangles’. Scientists are still exploring whether these changes in the brain lead to the symptoms of Alzheimer’s. One theory is that plaques prevent nerve cells inside the brain from communicating properly. Tangles may make it difficult for the cells to get the nutrients they need. Whatever the exact processes involved, it is clear that as Alzheimer’s develops certain nerve cells die, as seen from the brain of people who died from Alzheimer’s. Increasing numbers of nerve cells, also called neurons, are lost as the disease progresses. For this reason, Alzheimer’s is known as a neurodegenerative disease.

 

Can stem cells be used to treat Alzheimer’s disease?

 

No stem cell treatments for Alzheimer’s disease are yet available. Many different types of neurons in all parts of the brain are affected by the disease. This poses a complex problem if we want to replace the damaged brain cells. For example, when transplanting neural stem cells into the brain of an Alzheimer’s patient, even if healthy, working neural stem cells were available and could be transplanted safely, they would have to achieve several difficult tasks before any therapeutic benefits might be seen:

• travel into the multiple areas of the brain where damage has occurred

• produce the many different types of neurons needed to replace the damaged or lost cells

• do this in a way that enables the new neurons to integrate effectively into the brain, making connections to replace the lost parts of a complex network

Despite these significant challenges, scientists have been actively engaged in research on stem cell transplants in mice and studies have shown some benefits. Also,many scientists believe that Alzheimer’s patients will benefit from stem cells in a different way before the development of potential cell transplantation therapies. By using stem cells derived from Alzheimer patients to grow large numbers of brain cells in the lab, scientists can study the disease and search for new drugs.

 

How could stem cells help in Alzheimers?

 

It is hoped that eventually stem cells might assist in rebuilding lost nerve fibers. This could repair the damage caused in the progressive stages of Alzheimer's that results in the accumulation of permanent disability. Scientists around the world agree that more research is much needed in this complicated and challenging area.