Huntington’s disease research news. In plain language. Written by scientists. For the global HD community.
Clumps of mutant huntingtin protein in brain cells are a hallmark of HD, and they build up slowly, occupying more and more cells over time. Recent research in mice shows that the harmful proteins can travel between neurons, setting off a chain reaction that leads to more sick cells and the development of symptoms.
It’s like gardening gone wrong: scientists can sprinkle Huntington’s protein on the outside of laboratory-grown brain cells and make sticky, potentially harmful protein clumps grow inside the cells. Now, new research showing that human brain fluid does the same thing could help us monitor Huntington's disease.
A recent study by the Yang lab at UCLA points to a new idea for preventing damage to neurons in Huntington’s disease. The strategy is to tone down an overly helpful protein called ATM. Inside neurons, ATM provides a crucial role in repairing the cell’s infrastructure, somewhat like that of a bridge inspector, but the expanded HD protein may be causing ATM to misjudge DNA damage.
The growth factor 'BDNF' usually sends a “Survive!” signal to brain cells. In Huntington’s Disease (HD), this system doesn’t work as it should, so scientists have been looking for ways to boost the signal. Enter one of nature’s most useful tools: the antibody. Usually antibodies play an important role in the immune system, but researchers have identified two antibodies, produced by the company Pfizer, that can act like a set of spare keys to activate the TrkB receptor. This unlocks the door to determining whether a boost in TrkB activity is enough to prevent neurons from dying, in hopes of slowing the progression of HD.
Scientists can now reprogram human skin cells to make working cells that resemble 'medium spiny neurons', the type of brain cell that is most affected early in Huntington's disease. We're still a long way off from being able to replace the brain cells that are being lost in HD, but this research is an important step down that path, and is a great tool to study HD.
Huntington’s disease is caused by the accumulation of the toxic mutant huntingtin (mHTT) protein. This means that decreasing levels of mHTT, by boosting its breakdown, could be therapeutically beneficial. Palacino and colleagues have identified a possible contender for this role: negative regulator of ubiquitin-like protein 1, better known as NUB1.
Many types of stresses occur within cells that have the HD gene, and examining how simple organisms cope can help scientists define new targets for HD drugs. A new study examines yeast to determine which proteins can protect these cells from damage and death, uncovering a protective antioxidant and a related drug.
Certain regions of the brain degenerate more quickly than others in Huntington’s disease. Steven Finkbeiner’s team concludes that this discrepancy is based on differing abilities of brain cells in these regions to quickly identify and dispose of mutant HD protein. Specifically, neurons from vulnerable brain regions are slowest to clear the protein.
Figuring out how the mutant huntingtin protein causes damage is the central problem of Huntington's disease research. Now a team of Canadian researchers led by Dr Ray Truant has shown that the protein has an important 'hinge' function, which works less well in cells with the HD mutation. Exciting stuff, but contrary to what you might have read, it doesn't mean we no longer need to study mice!