The pursuit of a cure for Alzheimer’s disease has become an increasingly competitive and controversial quest, witnessing several important controversies in recent years.
In July 2022, science magazine Report that is a key 2006 research paper, published in prestigious journal the naturewhich identified a subtype of brain protein called beta-amyloid as the cause of Alzheimer’s, may be based on anecdotal evidence.
A year ago, in June 2021, The US Food and Drug Administration has approved aducanumabAn antibody-targeting beta-amyloid, as a treatment for Alzheimer’s, although data supporting its use were incomplete and conflicting.
Some physicians believe aducanumab should never have been approved, while others think it should be given a chance.
With millions of people in need of an effective treatment, why are researchers still scrambling to find a cure for one of the most important diseases facing mankind?
Getting out of the beta-amyloid rut
For years, scientists have focused on trying to come up with new treatments for Alzheimer’s Prevents the formation of brain-damaging clumps of this mysterious protein called beta-amyloid.
Indeed, we scientists have arguably gotten ourselves into an intellectual rut that focuses almost exclusively on this approach, often neglecting or even ignoring other possible explanations.
Unfortunately, this dedication to studying abnormal protein clumps has not translated into an effective drug or therapy. The need for a new “out-of-the-klump” approach to thinking about Alzheimer’s is emerging as a top priority in brain science.
My lab at the Krembill Brain Institute, part of the University of Toronto Health Network, is developing a plan New theories of Alzheimer’s disease.
Based on our research over the past 30 years, we no longer think of Alzheimer’s as primarily a brain disease. Rather, we believe that Alzheimer’s is predominant A disorder of the immune system in the brain.
The immune system, found in every part of the body, is a collection of cells and molecules that help repair injuries and defend against foreign invaders.
When a person trips and falls, the immune system helps repair damaged tissue. When someone experiences a viral or bacterial infection, the immune system helps fight these microbial invaders.
Exactly the same process is present in the brain. When a head injury occurs, the brain’s immune system helps repair it. When bacteria are present in the brain, the immune system is there to fight.
Alzheimer’s as an autoimmune disease
We believe that beta-amyloid is not an abnormally produced protein, but rather a normal molecule that is part of the brain’s immune system. Should be there.
When brain injury occurs or when bacteria are present in the brain, beta-amyloid is a key contributor to the brain’s extensive immune response. And this is where the problem begins.
Because of the striking similarities between the fat molecules that make up both bacterial membranes and brain cell membranes, beta-amyloid cannot tell the difference between invading bacteria and host brain cells and mistakenly attacks brain cells that are supposed to. protection
This leads to chronic, progressive loss of brain cell function, eventually leading to dementia – because our body’s immune system cannot distinguish between bacteria and brain cells.
Considered a misdirected attack by the brain’s immune system on the very organ it is supposed to protect, Alzheimer’s disease emerges as an autoimmune disease.
There are many types of autoimmune diseases, such as rheumatoid arthritis, in which autoantibodies play an important role in the development of the disease and for which steroid-based therapy may be effective. But these therapies won’t work against Alzheimer’s disease.
The brain is recognized as a very special and unique organ The most complex structure in the universe. In our Alzheimer’s model, beta-amyloid helps protect and strengthen our immune system, but unfortunately, it also plays a central role in the autoimmune process that, we believe, can lead to the development of Alzheimer’s.
Although drugs traditionally used to treat autoimmune diseases may not work against Alzheimer’s, we strongly believe that targeting other immune-regulatory pathways in the brain will lead to new and effective treatment approaches for the disease.
Other theories of disease
In addition to this autoimmune theory of Alzheimer’s, many new and varied theories have begun to appear. For example, some scientists believe Alzheimer’s is a disease of tiny cellular structures called mitochondria – Energy factory in every brain cell.
Mitochondria convert oxygen from the air we breathe and glucose from the food we eat into the energy we need to remember and think.
Some maintain that it is the end result of a Special brain infectionswith Bacteria from the mouth are often suggested as the culprit. Still others suggest that the disease may be caused by one Abnormal handling of metals in the brainProbably zinc, copper, or iron.
It’s satisfying to watch New thinking about this old disease. Dementia currently affects more than 50 million people worldwide, with a new diagnosis being made every three seconds. Often, people with Alzheimer’s disease do not recognize their own children or even their spouses of over 50 years.
Alzheimer’s is a public health crisis that requires innovative ideas and new directions.
For the well-being of people and families living with dementia and the socioeconomic impact of our already strained health-care system to cope with the ever-increasing costs and demands of dementia, we need a better understanding of Alzheimer’s, its causes, and how we can treat and manage it. What can I do to help the people and families who live there?
Donald WeaverProfessor of Chemistry and Director of the Krembil Research Institute, University Health Network, University of Toronto
Reprinted from this article the conversation Under Creative Commons license. After this Main article.
An earlier version of this article was published in September 2022.
