The journalists also had the rare opportunity of hearing a Nobel Laureate describe his work. Dr. Stanley Prusiner, of the University of California at San Francisco, winner of the Nobel Prize in Physiology or Medicine in 1997, took time for the journalists that morning, prior to delivering NIA’s prestigious Florence Mahoney Lecture that afternoon. Dr. Prusiner discussed his work on a novel class of protein-like infectious particles, dubbed prions. Well known in the research community, these “infectious proteins,” or prion proteins (PrP), cause several neurodegenerative diseases, including Creutzfeldt-Jakob disease in humans, scrapie in sheep, and bovine spongiform encephalopathy (BSE), otherwise known as “mad cow disease.” Dr. Prusiner’s research has turned a once obscure corner of medicine into an important source of new ideas about fundamental biological mechanisms in the etiology of these diseases.
Both prion diseases and AD cause dementia and death and are each associated with insoluble protein deposits that result in cell death. For example, once the brain is infected in scrapie, PrPsc (scrapie prion protein) accumulates and causes nerve cells (neurons) to malfunction. These PrPsc deposits, or plaques, consist chiefly of protein fragments collectively called amyloid. In AD, the amyloid is formed from a protein fragment named beta-amyloid, which itself is clipped from the larger protein APP. NIA-funded researchers have studied amyloid formation in prion diseases, and their findings may be useful in studying the pathway by which plaques are formed in AD.
Dr. Prusiner described his lab’s recent experiments in transgenic mice, which show promise for one day determining, for the first time, the levels of prions in brain and other tissues. Further research may lead to ways to stop the transmission of prion diseases between animal species and between animals and humans. It also will lead to an understanding of the biological mechanisms behind protein malformations in other types of dementia-related diseases, including AD. And finally, it will suggest avenues of research for new treatment strategies for both prion diseases and other dementia-related diseases. Currently, prion research involves primarily animal models and cell cultures. The development of new technologies, Dr. Prusiner stressed, is needed to advance this field of infectious proteins.
Source: Connections Magazine [Volume 8(1), Spring 1999]