Azara Blog: Prion proteins allegedly involved in protecting against Alzheimer's disease

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Date published: 2007/06/30

The BBC says:

Proteins which cause mad cow disease may also protect against Alzheimer's disease, UK researchers say.

Prions naturally present in the brain appear to prevent the build up of a key protein associated with the condition.

In laboratory tests, beta amyloid, the building block of Alzheimer's "plaques", did not accumulate if high levels of the prions were present.
In variant Creutzfeldt-Jakob disease (vCJD), the human version of mad cow disease, the normal version of the prion protein present in brain cells is corrupted by infectious prions causing it to change shape, resulting in brain damage and death.

But little is known about purpose of the normal prion proteins.

Due to the similarities between Alzheimer's and diseases such as variant CJD, researchers at the University of Leeds, looked for a link.

They found that in cells in the laboratory, high levels of the prions reduced the build-up of beta-amyloid protein, which is found in the brains of people with Alzheimer's disease.

In comparison, when the level of the prions was low or absent, beta amyloid formation was found to go back up again, suggesting they have a preventive effect on the development of the condition.

The researchers also looked at mice who had been genetically engineered to lack the prion proteins and again found that the harmful beta-amyloid proteins were able to form.

Study leader Professor Nigel Hooper said they now needed to look at whether ageing had an affect on the ability of the prion proteins to protect against Alzheimer's.

"Until now, the normal function of prion proteins has remained unclear, but our findings clearly identify a role for normal prion proteins in regulating the production of beta-amyloid and in doing so preventing formation of Alzheimer's plaques.

It's early days but it sounds quite interesting (and one would think that prion proteins would have a bigger role than just this).

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