Researchers discovered statins, a widely-prescribed cholesterol drug, could reverse learning deficits caused by a genetic disorder called Noonan syndrome.
The disorder can also cause unusual facial features and heart defects and there is currently no known treatment, the University of California - Los Angeles Health Sciences reported.
"Our approach identified the mechanism causing the disease, as well as a treatment that reversed its effects in adult mice. We are excited about these findings, because they suggest that the treatment we developed may help the millions of Noonan patients with intellectual disabilities," said principal investigator Alcino Silva, professor of neurobiology, psychiatry and psychology at the David Geffen School of Medicine at UCLA.
Many genes contribute to this disorder, but a single gene is believed to be responsible for about half of the cases. The gene encodes for a protein that regulates other proteins called Ras, which influences how brain cells talk to each other. The team discovered the Noonan mutation creates hyperactive Ras, which disrupts these cellular conversations.
"The act of learning creates physical changes in the brain, much like grooves on a record," Silva said. "Surplus Ras tips the balance between switching signals on and off in the brain. This interrupts the delicate cell communication needed by the brain to record learned information."
An overabundance of Ras was found to prematurely alter the brain's synapses, taking up room that should be used to record the changes necessary for learning.
To make their findings the researchers treated mice with lovastatin, which lowers cholesterol by blocking the synthesis of fat molecules that Ras needs to function, resulting in a drop in the communication-blocking protein.
"We were amazed to see that statin treatment restored the adult animals' cognitive functions to normal. Traditionally, science assumes that therapy needs to start in the fetal stage to be effective," Silva said. "Our research suggests that the leading gene mutation responsible for Noonan syndrome plays critical roles not only in fetal development, but also in how well the adult brain functions."
The findings were published in a recent edition of the journal Nature Neuroscience.
