AHFMR News

Heritage Investigator Publishes Key Prion Discovery

(Edmonton, AB) Tuesday September 13, 2005... A leading international scientific journal has published a study co-authored by Heritage researcher Dr. Valerie Sim. Along with collaborators from the National Institutes of Health in the U.S., Dr. Sim has discovered the size of the most infectious prion protein particle, which causes brain diseases such as mad cow disease and Creutzfeldt-Jakob disease. Their work is featured in the latest issue of the scientific journal NATURE.

Heritage clinical fellow Dr. Valerie Sim investigates prion proteins and their role in causing transmissible spongiform encephalopathies such as BSE (mad cow disease), scrapie, chronic wasting disease, and Creutzfeldt-Jakob disease. Dr. Sim is a physician researcher conducting her research at the National Institute of Allergy and Infectious Diseases' Rocky Mountain Laboratories in Hamilton Montana. She received her undergraduate and medical degrees at the University of Calgary and completed her neurology residency at the University of Ottawa. Dr. Sim receives support from the Alberta Heritage Foundation for Medical Research (AHFMR).

What:		Media opportunity to interview Dr. Valerie Sim
When:		Tuesday, September 13, 2005
Time:		10:00 AM to 12:00 noon *
Where:		The BACS Centre - Room G820 Health Sciences Centre - 3330 Hospital Dr. NW. Calgary

* Please call Dwayne Brunner, AHFMR Communications Coordinator, at (780) 966-1518 in order to arrange an interview.

Backgrounder

• Dr. Valerie Sim works with her mentor Dr. Byron Caughey researching the role of the prion protein in transmissible spongiform encephalopathies or prion diseases such as scrapie, BSE (mad cow disease), Creutzfeldt-Jakob disease, and chronic wasting disease.

• Prion diseases--also known as transmissible spongiform encephalopathies (TSEs) because the prions create holes in the brain, giving it a sponge-like appearance--include Creutzfeldt-Jakob disease in humans, mad cow disease in cattle, scrapie in sheep and chronic wasting disease in deer and elk. Scientists have known that infectious prion proteins form large fibrillar deposits in affected brains, but now, for the first time, the Rocky Mountain Laboratories' team has determined that the size of the most infectious aggregate is much smaller than expected.

• This new study of prions, which appear to be malformed proteins that initiate deadly brain diseases such as Creutzfeldt-Jakob disease in humans, has yielded new information about how the size of prions relates to their infectivity. Scientists have found that small prions are much more efficiently infectious than large ones, yet there also is a lower size limit, below which infectivity is lost.

• Many neurodegenerative diseases such as Alzheimer's, Parkinson's and TSE diseases are characterized by abnormal protein deposits in the brain, but questions abound as to what types and sizes of protein deposits are the prime causes of disease. The findings of this latest study support growing evidence for small protein aggregates, or oligomers, as major players in protein misfolding diseases.

• The Alberta Heritage Foundation for Medical Research (AHFMR) currently provides funding for over 600 researchers and researchers in training at the Province's three main universities. The foundation supports a community of researchers who generate knowledge that improves the health and quality of life of Albertans and people throughout the world. AHFMR's commitment is to fund health research based on international standards of excellence and carried out by new and established investigators and researchers in training. Total AHFMR funding over 25 years is in excess of $800 million. For more information, visit www.ahfmr.ab.ca