Creutzfeldt-Jakob disease in humans and scrapie in sheep are examples of transmissible spongiform encephalopathies (TSEs), fatal diseases that kill brain cells. Scientists believe TSEs are caused by the buildup of abnormal forms of prion protein that causes sponge-like holes in the brain. Using special mice, NIAID researchers have found a new prion disease that does not make holes in the brain. Instead, the disease damages brain blood vessels in a process called cerebral amyloid angiopathy, a symptom typical of Alzheimer’s disease. The study mice first had a molecular anchor genetically removed to prevent prion protein from attaching to brain cells. Researchers then infected the mice with scrapie and observed them for 500 days.
Upon examination, the mouse brains showed large accumulations of prion proteins trapped outside blood vessels and no holes in the brain. Mouse symptoms resembled the neurologic symptoms seen in people with cerebral amyloid angiopathy, which increases the risk of profuse bleeding and dementia. This is the first animal model to show that abnormal prion-protein accumulation can damage blood vessels without making holes in the brain. If scientists learn how to stop this new prion disease in mice, they may eventually be able to apply the same method to the treatment of Alzheimer’s disease.
Chesebro B, Race B, Meade-White K, Lacasse R, Race R, Klingeborn M, Striebel J, Dorward D, McGovern G, Jeffrey M, Fatal transmissible amyloid encephalopathy: a new type of prion disease associated with lack of prion protein membrane anchoring. PLoS Pathog. 2010 Mar 5;6(3):e1000800.
Last Updated November 10, 2011
Last Reviewed June 03, 2011