Nav: Home

New study suggests rethink of dementia causes

May 12, 2016

University of Adelaide researchers have developed a new theory for the causes of dementia and other neurodegenerative diseases, involving an out-of-control immune system.

Published in the journal Frontiers in Neuroscience, the researchers have assembled strong evidence that the neurological decline common to these diseases is caused by 'auto-inflammation', where the body's own immune system develops a persistent inflammatory response and causes brain cells to die.

"Dementia, including the most common form Alzheimer's Disease, and related neurodegenerative conditions are dramatically rising in frequency as people live longer and our population ages," says study lead Professor Robert Richards, from the University of Adelaide's School of Biological Sciences. "Australia is predicting that by 2050 there will be almost double the number of people with dementia, and the United States similarly says there will be twice as many.

"Currently we have no effective treatments to assist the millions of affected people, and these diseases are an enormous burden on families and the public health care system."

Previously, researchers have focused on the role of protein deposits called amyloid plaques that lodge in the brain of Alzheimer's affected people. But it is now clear that this is an inadequate explanation for Alzheimer's Disease.

There are many distinct forms of neurodegeneration including Alzheimer's, Parkinson's and Huntington's Diseases. These conditions are distinguished by the different types of brain nerve cells that are first affected and by the symptoms that first appear. However, as all of these diseases progress, they become more similar.

Professor Richards believes that instead of many different mechanisms, each disease has the same underlying mechanism, and common pathway of nerve cell loss.

"Our interest in the body's own (innate) immune system as the culprit began when we discovered that immune system agents become activated in a laboratory model of Huntington's Disease," he says. "Remarkably, researchers from other laboratories were at the same time reporting similar features in other neurodegenerative diseases. When we pulled the evidence together, it made a very strong case that uncontrolled innate immunity is indeed the common cause."

The innate immune system is the first line of defense in cells, and normally distinguishes molecules that belong to the body from foreign, disease-causing, molecules. It is an alarm and response system with a self-destruct mechanism to contain and eliminate invaders or abnormal cells, like cancer.

Malfunctions can occur because of various triggers including genetic mutations, infection, toxins or physical injury, all of which have been linked with different forms of neurodegeneration. Initially the innate immune system protects the tissue against these triggers, but prolonged activation becomes self-perpetuating, causing brain cell death to occur.

"We hope this new way of understanding neurodegeneration will lead to new treatments," Professor Richards says. "We now need to further investigate the immune signaling molecules, to identify new drug targets that will delay the onset and/or halt the progression of these devastating diseases."
-end-
Media Contact:

Professor Rob Richards, (currently in Washington DC, USA). Mobile: +61 (0)422 007 867, Skype: robrichards1.35, robert.richards@adelaide.edu.au

Dani Fornarino (in Adelaide), Phone: +61 (8) 8313 7557, Mobile: +61 (0)430 137 322, danielle.fornarino@adelaide.edu.au

David Ellis, Media Officer. Phone: +61 8 8313 5414, Mobile: +61 (0)421 612 762, david.ellis@adelaide.edu.au

University of Adelaide

Related Immune System Articles:

The immune system may explain skepticism towards immigrants
There is a strong correlation between our fear of infection and our skepticism towards immigrants.
New insights on how pathogens escape the immune system
The bacterium Salmonella enterica causes gastroenteritis in humans and is one of the leading causes of food-borne infectious diseases.
Understanding how HIV evades the immune system
Monash University (Australia) and Cardiff University (UK) researchers have come a step further in understanding how the human immunodeficiency virus (HIV) evades the immune system.
Carbs during workouts help immune system recovery
Eating carbohydrates during intense exercise helps to minimise exercise-induced immune disturbances and can aid the body's recovery, QUT research has found.
A new model for activation of the immune system
By studying a large protein (the C1 protein) with X-rays and electron microscopy, researchers from Aarhus University in Denmark have established a new model for how an important part of the innate immune system is activated.
Guards of the human immune system unraveled
Dendritic cells represent an important component of the immune system: they recognize and engulf invaders, which subsequently triggers a pathogen-specific immune response.
How our immune system targets TB
Researchers have seen, for the very first time, how the human immune system recognizes tuberculosis (TB).
How a fungus inhibits the immune system of plants
A newly discovered protein from a fungus is able to suppress the innate immune system of plants.
A new view of the immune system
Pathogen epitopes are fragments of bacterial or viral proteins. Nearly a third of all existing human epitopes consist of two different fragments.
TB tricks the body's immune system to allow it to spread
Tuberculosis tricks the immune system into attacking the body's lung tissue so the bacteria are allowed to spread to other people, new research from the University of Southampton suggests.

Related Immune System Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...