GeneAlert ... from UPI

ADDICTION, LEARNING LINKED TO COMMON PROTEIN

A gene that plays a key role in learning and memory also is a factor in drug addiction. Researchers at Duke University's Howard Hughes Medical Institute compared the activity of genes in the brains of mice that had "super-sensitivity" to cocaine due to a genetic defect or prior cocaine exposure to gene activity in the brains of normal mice. The comparison uncovered six genes with consistently increased or decreased levels of activity in the super-sensitive versus normal mice. In cocaine sensitive mice, levels of PSD-95, a protein encoded by one of these genes, was 50 percent lower than in the brains of normal mice. This protein had never before been linked to addiction, though it had been linked to learning. This study appeared in the Feb. 19 issue of Neuron.

MEDICAL CENTER ACQUIRES BIOTECH FIRM

The University of Pittsburgh Medical Center has acquired the biotechnology firm RheoGene Inc. The deal was made possible by a donation from the specialty chemical company Rohm and Haas. RheoGene Inc. has developed technology to manage gene expression, a key component of gene-based therapies. RheoGene's RheoSwitch inducible gene expression technology systems allow gene expression to be dialed up and down in a manner similar to a rheostat control on a light switch. This technology is effective in vitro and scientists are beginning the preclinical testing phase. The company said clinical trials in patients still are several years in the future. University of Pittsburgh Medical Center announced the acquisition Feb. 17.

NEW PROCESS ENHANCES NERVE FIBER REGENERATION

Combining gene therapy and the activation of the nerve cell growth state allowed scientists to enhance nerve fiber re-growth. Researchers at Children's Hospital Boston and Harvard Medical School studied the optic nerve, which connects nerve cells in the retina with visual centers in the brain. Normally, injured nerve fibers, or axons, cannot regenerate. Part of the problem is that several proteins present in the myelin sheath around axons strongly suppress growth. The researchers believed, however, they would have to do more than just block the inhibition -- they would need to activate the growth state at the same time. "When we combined these two therapies -- activating the growth program in nerve cells and overcoming the inhibitory signaling -- we got very dramatic regeneration," one researcher said. The amount of regeneration was not enough to restore sight but was about triple that achieved by stimulating growth factors alone. The results of the study were reported in the Feb. 18 Journal of Neuroscience.

FUTURE ATHLETES MAY USE GENETIC ENHANCEMENT

Athletes in the future may need to be tested for genetic enhancements rather than steroids. Researchers have found that combining genetic manipulation and weight training in rats yields leg muscles that are bigger and stronger than the muscles of rats exposed to just one of these two muscle-building techniques. The scientists injected a virus vector containing an IGF-1 rat gene into a hind-leg muscle of rats. The gene increased the production of the growth factor IGF-1, which promotes gains in muscle strength and mass. They also found rats with genetically elevated levels of IGF-1 retain more of their muscle mass after they stop exercising. Genetic enhancement of skeletal muscles could potentially benefit elite athletes, patients rehabilitating from injury-induced muscle wasting and elderly people who have diminished mobility due to muscular weakness. The study was reported at the Annual Meeting of the American Association for the Advancement of Science on Feb. 16 and will be published in the March issue of the Journal of Applied Physiology.

WHEN IT COMES TO CLONING, THE NOSE KNOWS

Scientists successfully cloned a mouse using mature olfactory neurons as the genetic donor. The researchers from the Whitehead Institute for Biomedical Research at the Massachusetts Institute of Technology and Columbia University credit the idea to the Woody Allen comedy "Sleeper," which depicted scientists trying to clone a dead dictator from his nose. The researchers chose olfactory neurons as the source for genetic material because previous research had suggested these cells might undergo gene rearrangements during development. "Our study demonstrates for the first time that animals can be derived from the nucleus of mature neurons following transfer into the (egg). Because the cloned animals are normal, our experiment also shows that (some) brain functions do not involve genetic alterations of the neuron's genome," said one researcher. The results of the study were reported Feb. 15 in the advance online publication of the journal Nature.

(EDITORS: For ADDICTION, contact Kendall Morgan at (919) 684-4148 or kendall.morgan@duke.edu. For UNIVERSITY, contact Michele Baum at (412) 647-3555 or baummd@upmc.edu. For NERVE, contact Aaron Patnode at (617) 355-5337 or aaron.patnode@childrens.harvard.edu. For STEROIDS, contact Monica Amarelo at (206) 774-6330 or mamarelo@aaas.org. For CLONING, contact Jim Keeley at (301) 215-8500 or keeleyj@hhmi.org)