Peripheral induction of Alzheimer's-like brain pathology in mice

Oct 21, 2010

Pathological protein deposits linked to Alzheimer's disease and cerebral amyloid angiopathy can be triggered not only by the administration of pathogenic misfolded protein fragments directly into the brain but also by peripheral administration outside the brain. This is shown in a new study done by researchers at the Hertie Institute of Clinical Brain Research (HIH, University Hospital Tübingen, University of Tübingen) and the German Center for Neurodegenerative Diseases (DZNE), to be published in Science on October 21, 2010.

Alzheimer's disease and a vascular disorder called cerebral beta-amyloid angiopathy are characterized by the accumulation of a protein fragment known as Abeta. In Alzheimer´s disease, misfolded Abeta is deposited mainly in so-called amyloid plaques, whereas in cerebral beta-amyloid angiopathy, the Abeta protein aggregates in the walls of blood vessels, interfering with their function and, in some cases, causing them to rupture with subsequent intracerebral bleeding.

In 2006, scientists in Tübingen, led by Mathias Jucker, reported that injection of dilute extracts from Alzheimer's disease brain tissue, or from Abeta-laden mouse brain tissue, into the brains of transgenic mice (genetically modified to produce the human form of Abeta) stimulated Abeta aggregation within the mouse brain (Science 313: 1781-4, 2006).

In the current Science study, Professor Jucker and first author Yvonne Eisele, together with their research team (HIH, University of Tubingen,DZNE) and colleagues Matthias Staufenbiel (Novartis), Mathias Heikenwälder (University of Zurich), and Lary Walker (Emory University Atlanta) report that Abeta deposition can be induced in the transgenic mouse brain by the intraperitoneal administration of mouse brain extract containing misfolded Abeta. This induced Abeta deposition was primarily associated with the vasculature, but was also evident as amyloid plaques between nerve cells.

The time needed to induce amyloid deposition in the brain was much longer for peripheral as compared to direct brain administration. In both cases, the induced amyloid deposition also triggered several neurodegenerative and neuroinflammatory changes commonly observed in the brains of patients with Alzheimer´s disease and cerebral beta-amyloid angiopathy.

"The finding that mechanisms exist allowing for the transport of Abeta aggregates from the periphery to the brain raises the question of whether protein aggregation and propagation, which may also be involved in other neurodegenerative brain diseases, can be induced by agents originating in the periphery", points out Professor Jucker. The present findings provide new clues on pathogenetic mechanisms underlying Alzheimer's disease; further investigation will likely lead to new strategies for prevention and treatment.

While this molecular principle of induced aggregation bears similarities to that of prion diseases, the latter, which include bovine spongiform encephalopathy (BSE), can also be initiated by introducing prions at sites peripheral to the brain. The present study shows that this is not a characteristic unique to prion diseases, as has been assumed so far. Despite this remarkable observation and the apparent mechanistic similarities between Alzheimer´s and prion diseases, there is no evidence that or cerebral amyloid angiopathy is transmitted between mammals or humans in the same manner as prion diseases.

Explore further: First vital step in fertilization between sperm and egg discovered

More information: Yvonne S. Eisele et al., Title of the original publication: Peripherally Applied Ab-Containing Inoculates Induce Cerebral b-Amyloidosis, Advanced online publication in Science, Science Express Website 21 October 2010. www.scienceexpress.org/

Related Stories

Alzheimer's prevention role discovered for prions

Jul 03, 2007

A role for prion proteins, the much debated agents of mad cow disease and vCJD, has been identified. It appears that the normal prions produced by the body help to prevent the plaques that build up in the brain to cause Alzheimer’s ...

Mutant proteins result in infectious prion disease in mice

Dec 05, 2008

A worldwide group of scientists has created an infectious prion disease in a mouse model, in a step that may help unravel the mystery of this progressive disease that affects the nervous system in humans and animals. The ...

Recommended for you

Bionic ankle 'emulates nature'

4 hours ago

These days, Hugh Herr, an associate professor of media arts and sciences at MIT, gets about 100 emails daily from people across the world interested in his bionic limbs.

Firm targets 3D printing synthetic tissues, organs

6 hours ago

(Medical Xpress)—A University of Oxford spin-out, OxSyBio, will develop 3D printing techniques to produce tissue-like synthetic materials for wound healing and drug delivery. In the longer term the company ...

User comments : 0

More news stories

Unraveling the 'black ribbon' around lung cancer

It's not uncommon these days to find a colored ribbon representing a disease. A pink ribbon is well known to signify breast cancer. But what color ribbon does one think of with lung cancer?

Classifying cognitive styles across disciplines

Educators have tried to boost learning by focusing on differences in learning styles. Management consultants tout the impact that different decision-making styles have on productivity. Various fields have ...

Tiny power plants hold promise for nuclear energy

Small underground nuclear power plants that could be cheaper to build than their behemoth counterparts may herald the future for an energy industry under intense scrutiny since the Fukushima disaster, the ...

Hand out money with my mobile? I think I'm ready

A service is soon to launch in the UK that will enable us to transfer money to other people using just their name and mobile number. Paym is being hailed as a revolution in banking because you can pay peopl ...