Protein Could Slow Degenerative Brain Diseases
By Stephen Pincock
LONDON (Reuters Health) - A type of protein that helps cells respond to heat, cold and other environmental stresses could one day be used to slow down degenerative brain diseases like Alzheimer's, Parkinson's and Huntington's, British researchers said on Friday.
Early research suggests that so-called heat shock proteins could also help against conditions such as motor neurone disease and stroke damage, said Professor Jacqueline de Belleroche from Imperial College London.
"At present, there is no cure for neuro-degenerative diseases, such as Alzheimer's and Parkinson's, but the discovery of the beneficial effects of this protein in the brain may provide us with a way to at least slow down the disease process," she said.
In the Journal of Biological Chemistry, de Belleroche and colleagues report that the naturally occurring heat shock protein Hsp27 was able to reduce brain cell death in animal experiments.
Mice engineered to have high levels of the protein throughout the brain, spinal cord and other tissues had lower rates of death and brain cell death after they were injected with a toxic substance that damages cells. The protective effect was seen in the hippocampus, a part of the brain affected by neurological diseases.
In earlier studies, the researchers achieved similar results when they injected Hsp27 directly into the brain.
"Although this is unlikely to provide a cure for neuro-degenerative disorders, it could be vital in slowing their progress," de Belleroche said. "Eventually it may be possible to use a drug to increase levels of Hsp27 in the brain which could be given to those suffering from neuro-degenerative diseases."
All cells contain a range of heat shock proteins and the proteins are produced in response to environmental stresses like heat, cold and low oxygen levels. Under normal conditions they act like "chaperones" to make sure a cell's proteins are in the right place and shape at the right time.
"It's one of the systems we think is a natural defense system," de Belleroche told Reuters Health. "We're looking at trying to boost the natural system and hopefully translate it into treatment."
The heat shock proteins might achieve their effects by stopping the buildup of solid structures or aggregates within brain cells, a process that characteristically triggers cell death in neuro-degenerative diseases, she said.
"What this and other heat shock proteins do ... is stop those insoluble aggregates (from) forming, and they help to re-fold the protein so it can arrest the process."
The next step is to pin-point exactly when the heat shock protein acts in the chain-reaction of events leading to cell death, and develop drugs to affect that process, she said.
"It's a line that we're hoping to pursue," de Belleroche said. "We're testing out a few compounds but we haven't got any results yet."
SOURCE: Journal of Biological Chemistry 2003;278. |
