Tampa, FL (Dec. 3, 2010) -- Dynamic regulation of the chaperone protein Hsp27 was required to get rid of abnormally accumulating tau in the brains of mice genetically modified to develop the memory-choking tau tangles associated with Alzheimer's disease, a University of South Florida-led study found.
Researchers at the USF Health Byrd Alzheimer's Institute demonstrated that the effective switching of Hsp27 between its active and deactivated states was critical on two fronts -- to promote the recycling of the tau protein in healthy nerve cells and to clear abnormal tau from the brain before the protein could clump together into the sticky tau neurofibrillary tangles that kill brain cells involved in memory formation. Their findings were published online Nov.17, 2010 in the Journal of Neuroscience.
"Our study shows that Hsp 27 may be a double-edged sword depending upon the contextual environment of neurons in the brain," said the study's principal investigator Chad Dickey, PhD, associate professor of molecular medicine at USF Health. "By better defining the mechanisms linking chaperone proteins to both the tau aggregation and degradation pathways, we can move toward more individualized, effective therapies targeting Alzheimer's and other distinct neurological disorders."
Hsp27 is one of several "chaperone" proteins that supervises the activity of tau inside nerve cells, ensuring that the tau protein is properly folded into its complex form. If tau somehow becomes misfolded, the protein cannot accomplish its normal job of helping maintain the structure of nerve cells. The improperly folded (abnormal) tau starts stacking up into tangles inside cells involved in memory and destroying them.
The USF study was done using mice genetically engineered to develop tau protein tangles like those found in the brains of people with Alzheimer's disease. In one experiment, the researchers injected into the brains of 4-month-old Alzh
|Contact: Anne DeLotto Baier|
University of South Florida (USF Health)