"We can't draw direct parallels between mice and humans, because OCD behavior in mice shows up as excessive self-grooming, and in humans there is a broad spectrum of behaviors, from hand-washing to other compulsive actions as well as obsessive thoughts," says Dr. Lee. "But our finding of altered brain functioning suggests a very strong link at this point to some of the issues seen in humans."
The research team cannot say why a gene found in blood stem cells and vascular cells could be implicated in a behavioral brain disorder, but they speculate that "cross-talk" between the vascular system in the brain and neurons in brain tissue may be the link.
Dr. Rafii and his colleagues had previously identified Slitrk5 in the progenitor stem cells that create blood, and they subsequently demonstrated that the protein created by this gene is expressed in leukemia, embryonic stem cells, and in subsets of endothelial cells, which are the basic building blocks for the circulatory system.
In this study, the researchers were looking at the effects created when the Slitrk5 gene was "knocked out" in laboratory mice and replaced with a "reporter" gene. "We did this because we wanted to look at the effect on the blood system, which is what we are primarily interested in," says Dr. Shmelkov. "But we didn't find anything, which was frustrating."
But then Dr. Shmelkov and Dr. Hormigo noticed that some of the knockout mice began to develop facial lesions, and over time, all of the mice without Slitrk5 eventually developed the same skin issues. They also noticed that the mice were hyperactive and seemed to groom themselve
|Contact: Andrew Klein|
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College