The blood-brain barrier in Alzheimer’s disease

By Fiona McLean

Blood vessels are everywhere in our body and supply oxygen and fuel to organs to keep them working properly. Everywhere in our brain is a group of cells that form a barrier between the blood and the nerve cells, the ‘blood-brain barrier’. The main cell type present in the blood-brain barrier are endothelial cells. These cells act like a bouncer on a nightclub door, deciding what goes into the brain or what gets ejected. However, in dementia-related diseases, such as Alzheimer’s disease, the blood-brain barrier no longer works properly. This causes many problems, including the entry of toxins into the brain, improper use of essential nutrients, such as oxygen and glucose, and failure to clear waste products from the brain. Failure of the blood-brain barrier can occur early in Alzheimer’s disease and may contribute to the progression of the disease.

My research, at the University of Dundee and funded by Alzheimer’s Research UK, will examine what causes the blood-brain barrier to malfunction in Alzheimer’s disease. One of the main goals is to understand what changes occur in the blood-brain barrier before and after the build-up of amyloid. Amyloid is one of the main pathological features of Alzheimer’s disease and in more than 80% of patients, amyloid is found in the blood vessels of the brain, a condition called cerebral amyloid angiopathy. The frequency of cerebral amyloid angiopathy occurring in patients with Alzheimer’s disease further highlights why it is important that we investigate the blood-brain barrier and how it is affected in Alzheimer’s disease.

Another goal of my research is to better understand which factors stimulate the development of Alzheimer’s disease. The cause of most sporadic cases is currently unknown; however, we do know that there are a number of modifiable risk factors associated with the ‘metabolic syndrome’ that may increase the risk of developing Alzheimer’s disease. The metabolic syndrome is a cluster of conditions that occur simultaneously, including obesity, type 2 diabetes, high blood pressure, high levels of triglycerides (fat) in the blood, and low levels of high-density lipoprotein (“good” cholesterol) in the blood. An important part of my research is to find out how the metabolic syndrome can cause Alzheimer’s disease and whether it causes problems in the blood-brain barrier. It is vital to understand the sequence of events leading up to and after blood-brain barrier problems and to better understand how metabolic syndrome can exacerbate outcomes.

The bad news is that ‘metabolic syndrome’ is on the rise in many countries and may be a key factor in the rise of Alzheimer’s cases. However, the good news is that if we change our lifestyle, up to 40% of dementia cases can be delayed or even prevented. It’s really important to get the word out that living a healthier lifestyle can protect your brain, as only 33% of people think it’s possible to reduce the risk. A public health campaign, “Think Brain Health,” has been launched to raise awareness and provide tips on how to take care of your brain.

Dementia is now a global epidemic and we need to use every inch of innovative science and creative thinking to make progress faster than we’ve ever seen. It is essential to support research into Alzheimer’s disease and other dementia-related diseases. Charities are huge contributors to ongoing research, but we need governments to deliver on the ‘moonshot’ funding commitment that has been promised for years. There is currently no cure for dementia and Alzheimer’s disease, although it is the leading cause of death in some countries. One of the worst things about this devastating disease is that not only does it cost your life, but it can steal your memories, which makes you who you are. This is why we need to push harder than ever to understand and stop Alzheimer’s disease.

The blood-brain barrier is the first line of defense to protect our brains. If we can make the blood-brain barrier work, we can protect the rest of our brain cells. There are currently no drugs for Alzheimer’s disease that target the blood-brain barrier, meaning there is a whole area of ​​potential drug discovery that has been untapped and could lead to a new generation of treatments. My research is a first step towards making these new medicines.

(The author is Alzheimer’s Research UK Fellow, University of Dundee. Opinions expressed are personal and do not reflect the official position or policy of

Leave a Reply

Your email address will not be published. Required fields are marked *