Posted by Ted (205.188.199.174) on January 14, 2002 at 14:44:28:
Scientists find key pain protein -- study
By Gene Emery
BOSTON, Jan 10 (Reuters) - Researchers have identified a key protein that controls severe pain, a discovery that might someday allow more relief for those who suffer intractable pain from terminal cancer, chronic backaches and other problems, according to Thursday's issue of the journal Cell.
The protein is known by the acronym DREAM. In tests on mice bred to have a defective form of DREAM, the researchers discovered the animals seem completely normal, except their sensitivity to pain was greatly diminished.
And while there are many types of pain, disabling the DREAM protein seems to reduce them all, said Dr. Josef Penninger of the University of Toronto, a coauthor of the study.
Pain is vital to survival, allowing us to quickly draw away from scalding water or a sharp object. DREAM, according to the new research, keeps people sensitized to pain.
But over time, such as after a person experiences a cut, the sharp pain fades because the DREAM protein becomes disabled, Penninger told Reuters in a telephone interview.
"DREAM lets you feel pain. When it doesn't work anymore, you don't feel it anymore."
If researchers could find a way to disable the protein, it could lead to a new and perhaps more effective method of pain control, he said.
However, he cautioned that finding such a treatment could be challenging because the protein works deep inside individual cells, making it less accessible to drugs.
"This is simply a beginning," Penninger said. "But if you can change DREAM, you can change pain."
The DREAM protein was discovered by other researchers but was originally implicated in Alzheimer's disease and heart function. Thus, when the people in Penninger's laboratory created a strain of mice that lacked a properly working DREAM protein, they expected to see heart and memory problems.
Instead, testers at NeuroDetective in Alberta, which screens mice strains for various defects, reported back to Penninger that the hearts and memory skills seemed fine. However, the animals weren't responding normally to pain.
Mice with the defective DREAM protein appeared to feel about 50 percent less sharp pain when exposed to heat or some other stimulus.
A treatment based on control of DREAM would be particularly useful to people with chronic pain conditions, Penninger said. For example, people with chronic back pain are often plagued because the more pain they experience, the worse the pain seems to become.
"The more they have, the more sensitive they get to it," he said. "In DREAM mutants, there was no sensitization whatsoever. ... With every pain we tested them with, the pain was much, much reduced," he said.
DREAM stands for downstream regulatory element antagonistic modulator.