A study led by University of British Columbia and Vancouver Coastal Health Research Institute researchers has revealed how the fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is transmitted from cell to cell, and suggests the spread of the disease could be blocked.
“This work identifies an important piece of the puzzle in determining how the disease is transmitted throughout the nervous system,” says lead investigator Dr. Neil Cashman, UBC’s Canada Research Chair in Neurodegeneration and Protein Misfolding. “By understanding how this occurs, we can devise the best ways to stop the progressive neurological damage seen in ALS.”
The research shows that misfolded non-mutant SOD1 can be transmitted from region to region in the nervous system, offering a molecular explanation for the progressive spread of ALS.
Published today in the Proceedings of the National Academy of Sciences, the study also shows the spread can be blocked using antibodies. Antibodies were specifically raised to bind to regions of SOD1 exposed when it is misfolded, and block its spread. If non-mutant SOD1 misfolding is the cause of ALS, as the study suggests, then the antibodies could arrest ALS progression, the researchers say.
This work builds on previous research in Cashman’s lab. ALS is associated with the mutant SOD1 protein (superoxide dismutase 1) and earlier investigations found that the disease-associated mutant SOD1 can induce a change in the shape of other proteins at the molecular level by misfolding inside living cells. The affected proteins then accumulate in ways similar to the process underlying prion diseases – rare, fatal, degenerative brain disorders seen in both humans and animals.
ALS is a disease that affects nerve cells in the brain and the spinal cord. Motor neurons progressively degenerate and die so that the brain can no longer initiate and control muscle movement. Patients in the later stages of the disease may become totally paralyzed. There are approximately 140,000 new cases diagnosed worldwide each year.
Notes about this ALS and neurodegeneration research
Dr. Neil Cashman is Professor and Canada Research Chair in Neurodegeneration and Protein Misfolding at UBC, and Academic Director of the Vancouver Coastal Health ALS Centre. He is also a member of the Brain Research Centre, a partnership between UBC and Vancouver Coastal Health Research Institute.
Prion diseases belong to the general category of brain diseases called proteinopathies, which also includes Alzheimer’s disease and Parkinson’s disease. The most common human form of prion disease is Creutzfeldt-Jakob disease (CJD).
Prion diseases of animals include Bovine Spongiform Encephalopathy (BSE) (mad cow disease) in cattle, scrapie in sheep and goats, and Chronic Wasting Disease (CWD) in deer and elk.
Contact: Hilary Thomson – University of British Columbia
Source: University of British Columbia press release
Image Source: The image is credited to Frank Gaillard and is licensed as Creative Commons Attribution-Share Alike 3.0 Unported
Original Research: Full open access research for “Intercellular propagated misfolding of wild-type Cu/Zn superoxide dismutase occurs via exosome-dependent and -independent mechanisms” by Leslie I. Grad, Justin J. Yerbury, Bradley J. Turner, William C. Guest, Edward Pokrishevsky, Megan A. O’Neill, Anat Yanai, Judith M. Silverman, Rafaa Zeineddine, Lisa Corcoran, Janet R. Kumita, Leila M. Luheshi, Masoud Yousefi, Bradley M. Coleman, Andrew F. Hill, Steven S. Plotkin, Ian R. Mackenzie, and Neil R. Cashman in PNAS. Published online February 18 2014 doi:10.1073/pnas.1312245111