Two related studies from Northwestern University offer new strategies for tackling the challenges of preventing and treating diseases of protein folding, such as Alzheimer's, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis (ALS), cancer, cystic fibrosis and type 2 diabetes. To do its job properly within the cell, a protein first must fold itself into the proper shape. If it doesn't, trouble can result. More than 300 diseases have at their root proteins that misfold, aggregate and eventually cause cellular dysfunction and death. The new Northwestern research identifies new genes and pathways that prevent protein misfolding and toxic aggregation, keeping cells healthy, and also identifies small molecules with therapeutic potential that restore health to damaged cells, providing new targets for drug development.
Treatment that increases brain levels of an important regulatory enzyme may slow the loss of brain cells that characterizes Huntington's disease (HD) and other neurodegenerative disorders. In a report receiving advance online publication in Nature Medicine, a Massachusetts General Hospital (MGH)-based research team reports that increased expression of Sirt1, one of a family of enzymes called sirtuins, in the brain of a mouse model of HD protected against neurodegeneration. They also identified a potential mechanism for this protective effect. "Diseases such as Huntington's, Parkinson's and Alzheimer's disease have different causative factors, but they share common themes - such as aggregation of misfolded proteins - and a unifying endpoint, the degenerative loss of neurons, " says Dimitri Krainc, MD, PhD, of the MassGeneral Institute for Neurodegenerative Disease (MGH-MIND), the study's senior author.
Working with genetically engineered mice, Johns Hopkins researchers have discovered that a gene (SIRT1) linked to slowing the aging process in cells also appears to dramatically delay the onset of Huntington's disease (HD) and slow the progression of the relentless neurodegenerative disorder. HD in humans is a rare, fatal disorder caused by a mutation in a single gene and marked by progressive brain damage. Symptoms, which typically first appear in midlife, include jerky twitch-like movements, coordination troubles, psychiatric disorders and dementia. Although the gene responsible for HD was identified in 1993, much is still unknown about the biology of the disease. There is no cure, and there are no effective treatments. In studying two separate mouse models of HD, the Johns Hopkins team found that mice bred with Huntington's disease and a greater than usual amount of the enzyme whose blueprint is carried by the SIRT1 gene had improved motor function and reduced brain atrophy.
New Drug That Improves Memory And Prevents Brain Damage In Mice May Prevent Alzheimer's Disease Progression
A new drug candidate may be the first capable of halting the devastating mental decline of Alzheimer's disease, based on the findings of a study published in PLoS one. When given to mice with Alzheimer's, the drug, known as J147, improved memory and prevented brain damage caused by the disease. The new compound, developed by scientists at the Salk Institute for Biological Studies, could be tested for treatment of the disease in humans in the near future. "J147 enhances memory in both normal and Alzheimer's mice and also protects the brain from the loss of synaptic connections, " says David Schubert, the head of Salk's Cellular Neurobiology Laboratory, whose team developed the new drug. "No drugs on the market for Alzheimer's have both of these properties." Although it is yet unknown whether the compound will prove safe and effective in humans, the Salk researchers' say their results suggest the drug may hold potential for treatment of people with Alzheimer's.
Study Identifies Most Effective Ways To Assess Progression In Huntington's Disease, Which Could Speed Up Development Of Disease-modifying Drugs
Researchers have identified a set of objective, validated measures for evaluating new treatments for Huntington's disease (HD) in phase 2 and 3 clinical trials. According to the researchers, whose findings have been published Online first in The Lancet Neurology, the discovery should increase future new drug trial's chances of success to delay onset and reduce the severity of HD. Lead author, Sarah Tabrizi from University College London's Institute of Neurology in London, UK, explains: "HD research is at a critical point, with new drugs in the later stages of development, and we propose a battery of assessments for use in clinical trials in people with early HD. Hypothetical treatment effects defined by slower longitudinal changes in these measures should be detectable over a realistic timescale with practical sample sizes.