Dr. Neil CashmanPrioNet Canada researchers in Vancouver confirm
prion-like properties in Amyotrophic Lateral Sclerosis (ALS)
September 20, 2011 - Vancouver, BC: A team of researchers from the University of British Columbia and the Vancouver Coastal Health Research Institute have found a key link between prions and the neurodegenerative disease ALS (Amyotrophic Lateral Sclerosis), also known as Lou Gehrig's disease. The discovery is significant as it opens the door to novel approaches to the treatment of ALS.
SOD-1 DimerA pivotal paper published by the team this week in the Proceedings of the National Academy of Sciences (PNAS), demonstrates that the SOD1 protein (superoxide dismutase 1), which has been shown to be implicated in the ALS disease process, exhibits prion-like properties. The researchers found that SOD1 participates in a process called template-directed misfolding. This term refers to the coercion of one protein by another protein to change shape and accumulate in large complexes in a fashion similar to the process underlying prion diseases.
These findings provide a molecular explanation for the progressive spread of ALS through the nervous system, and highlight the central role of the propagation of misfolded proteins in the pathogenesis of neurodegenerative diseases, including ALS, Alzheimer's and Parkinson's.
"Our work has identified a specific molecular target, which when manipulated halts the conversion of the SOD1 protein to a misfolded, disease-causing form," says Dr. Neil Cashman, Scientific Director of PrioNet Canada, Canada Research Chair in Neurodegeneration and Protein Misfolding at UBC, and academic director of the Vancouver Coastal Health ALS Centre. "This discovery is a first-step toward the development of targeted treatments that may stop progression of ALS."
ALS is a progressive neuromuscular disease in which nerve cells die, resulting in paralysis and death. Approximately 2,500 to 3,000 Canadians currently live with this fatal disease, for which there is no effective treatment yet.
"For many years, ALS has remained a complex puzzle and we have found a key piece to help guide the research community to solutions," says Dr. Leslie Grad, a co-first author of the project and current Manager of Scientific Programs at PrioNet Canada. "PrioNet is further exploring this discovery through newly-funded research projects."
The work was completed by Dr. Neil Cashman's lab at the Brain Research Centre based at the University of British Columbia and the Vancouver Coastal Health Research Institute, in collaboration with researchers at the University of Alberta. The research was supported by PrioNet Canada and in part by Amorfix Life Sciences and the Canadian Institutes of Health Research.
PrioNet Canada, based in Vancouver, has achieved international attention for scientific discoveries and risk management strategies directed at controlling prion diseases, and is now directing capacity into therapeutic solutions for prion-like diseases of aging, such as Alzheimer's, Parkinson's and ALS.
One of Canada's Networks of Centres of Excellence, PrioNet Canada (www.prionetcanada.ca) is developing strategies to help solve the food, health safety, and socioeconomic problems associated with prion diseases. The network brings together scientists, industry, and public sector partners through its multidisciplinary research projects, training programs, events, and commercialization activities. PrioNet is hosted by the University of British Columbia and the Vancouver Coastal Health Research Institute in Vancouver.
The University of British Columbia (UBC) is one of North America's largest public research and teaching institutions, and one of only two Canadian institutions consistently ranked among the world's 40 best universities. UBC is a place that inspires bold, new ways of thinking that have helped make it a national leader in areas as diverse as community service learning, sustainability and research commercialization. UBC offers more than 50,000 students a range of innovative programs and attracts $550 million per year in research funding from government, non-profit organizations and industry through 7,000 grants.
Vancouver Coastal Health Research Institute (VCHRI) (www.vchri.ca) is the research body of Vancouver Coastal Health Authority, which includes BC's largest academic and teaching health sciences centres: VGH, UBC Hospital, and GF Strong Rehabilitation Centre. In academic partnership with the University of British Columbia, VCHRI brings innovation and discovery to patient care, advancing healthier lives in healthy communities across British Columbia, Canada, and beyond.
The Brain Research Centre (BRC) (www.brain.ubc.ca) comprises more than 200 investigators with multidisciplinary expertise in neuroscience research ranging from the test tube, to the bedside, to industrial spin-offs. The centre is a partnership of UBC and Vancouver Coastal Health Research Institute.
Media information or to set up interviews:
Gail Bergman, Gail Bergman PR
Tel: (905) 886-1340 or (905) 886-3345
BACKGROUNDER - ALS as a "prion-like" disease
Amyotrophic lateral sclerosis (ALS):
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig 's disease in the United States and motor neurone disease (MND) in Europe, is a fatal neurodegenerative disease caused by deterioration of motor neurons in the brain and spinal cord. Individuals living with the disease experience progressive paralysis, as well as difficulty breathing or swallowing. At this time, no cure or effective treatment exists.
According to the ALS Society of Canada: ALS is the most common cause of neurological death Every day two or three Canadians die of ALS Eighty per cent of people with ALS die within two to five years of diagnosis; ten per cent of those affected may live for 10 years or longer Approximately 2,500 - 3,000 Canadians currently live with this fatal disease The World Health Organization predicts that neurodegenerative diseases will surpass cancer as the second leading cause of death in Canada by 2040
Recent research highlights links between the biological mechanisms of common neurological disorders, such as ALS, Alzheimer's and Parkinson's disease with prion disease. While each of these diseases manifests itself in a different way, the hallmark of each is a progressive accumulation of misfolded protein aggregates in the central nervous system.
Correctly-folded proteins adopt one particular structure in order to carry out their intended function. A protein's failure to adopt this correct structure is what threatens the health of cells. Prions are "misfolded" proteins - the infectious, aggregating agents in diseases such as Creutzfeldt-Jakob disease (CJD) in humans, chronic wasting disease (CWD) in deer and elk and bovine spongiform encephalopathy (BSE), also known as "mad cow" disease in cattle. In ALS, Alzheimer's and Parkinson's, the misfolded proteins are SOD1, amyloid-B and a-synuclein, respectively.
"Intermolecular transmission of SOD-1 misfolding in living cells" - Published in the Proceedings of the National Academy of Sciences (PNAS), September 2011 The paper shows that superoxide dismutase 1 (SOD1) participates in template-directed misfolding, in other words, the coercion of one protein by another protein to change shape and aggregate such as prion diseases do. The results will be significant to the ALS field because it connects prion mechanisms behind the biological progression of ALS, and provides a molecular explanation for the linear and temporal spread of ALS through the nervous system. Furthermore, the research has identified a specific molecular target, which when manipulated, halts the conversion of SOD1 to a misfolded, disease-causing form. This is a first-step towards the development of targeted treatments that may stop ALS, which PrioNet is further exploiting through newly-funded research. This research was supported by PrioNet Canada and in part by Amorfix Life Sciences and the Canadian Institutes of Health Research.
Studies showing how "seed" misfolded protein induce aggregation of other protein, which provide evidence for prion-like spread: Lary Walker's group at Emory University in Atlanta, in collaboration with Matthias Jucker and others at the Universities of Tübingen in Germany and Basel in Switzerland, discovered that aggregates of amyloid-β protein from the brain of people with Alzheimer's disease could be transmitted to the brain of healthy mice. Another study by Patrik Brundin's group in Sweden demonstrated that healthy tissue surgically implanted into the brain of people with Parkinson's disease acquired the aggregates of α-synuclein protein characteristic of the disease. Eliezer Masliah of the University of California San Diego and others discovered that aggregates of a-synuclein can travel from cell to cell, forming the aggregates in human neurons that are characteristic of Parkinson's disease and certain types of dementia. Anne Bertolotti from the University of Cambridge discovered that neuronal cells spontaneously and efficiently take up misfolded mutant SOD1 from their environment. The internalized mutant SOD1 triggers a change in shape of the normally soluble mutant SOD1 protein, which causes its aggregation, and is then transferred to neighbouring cells in a prion-like fashion.