Posted by Rob Ring, Ph.D., vice president of translational research for Autism Speaks
One of our primary goals at Autism Speaks is to help develop the careers of promising young scientists who demonstrate the potential to greatly advance the field of autism research. Training fellowships are one important means to this end. These fellowships allow highly qualified pre-doctoral and doctoral students to pursue research projects under the mentorship of the brightest minds in the autism field. These are essential investments in the future, and we are always thrilled when we see these investments pay dividends.
Last month, an important study published in Nature Genetics culminated a research project started in 2006 by one of our first pre-doctoral fellows, Rodney Samaco. Rodney, now Dr. Samaco, is an assistant professor of molecular and human genetics at Baylor College of Medicine, in Texas.
Before describing the results of Dr. Samaco’s exciting study, let me first provide a little background. Samaco’s mentor during his Autism Speaks fellowship was the renowned pediatric neurogeneticist Huda Zoghbi, who is credited with co-discovering the genetic cause of Rett syndrome. Rett syndrome is a profoundly disabling disorder that primarily affects girls and is associated with high rates of autism.
The genetic mutations behind Rett syndrome result in the reduced production of a protein called methyl CpG binding protein 2, or MeCP2. MeCP2 is a protein that regulates the activity of hundreds of downstream target genes.
Interestingly, autism has recently been described in boys who carry duplications of the same gene. MeCP2 gene duplication results in increased production of the same protein that’s in short supply in Rett syndrome. This suggests that the brain needs just the right level of MeCP2 to function properly, and has led some to call MeCP2 the “Goldilocks gene.”
The field has learned an enormous amount about the basic underlying biology of Rett syndrome by studying mice that have been genetically altered to produce reduced levels of the MeCP2 protein – in effect mimicking what occurs in girls affected by Rett syndrome. When compared to normal mice, these mice display autism-like behaviors and physiological problems similar to those seen in people.
Now comes Dr. Samaco’s recent paper: In it, he describes work with a new mouse, genetically altered to have an additional copy of MeCP2 and therefore increased levels of the protein. This “duplication mouse” models the opposite of what occurs in Rett, and is more relevant to the MeCP2 duplication syndrome that predisposes boys to autism.
In this duplication mouse, Dr. Samaco and his collaborators were able to show that two key downstream genes regulated by MeCP2 were increased in key brain regions of these mice. This, in turn, was associated with reduced social behavior and increased anxiety-like behaviors.
Of particular interest Dr. Samaco used genetic tools to turn down the activity of these genes and reverse the social deficits and reduce anxiety. What’s more, he achieved the same results using drugs designed specifically to reduce the activity of these targets.
This demonstrates that MeCP2-related behavior abnormalities are reversible. It further suggests that similar therapies for humans have the potential to alleviate autism symptoms and anxiety in individuals carrying duplications of MeCP2.
This study is just one example of how our research fellows are affecting the direction and progress of autism research in wonderful ways.
Three years ago, we created the Dennis Weatherstone Pre-Doctoral Fellowship Program through a generous donation from the Stavros Niarchos Foundation. We thank the foundation and all of you – our supporters – for investing in the gifted and passionate scientists we fund. We are gratified to see their work continually prove the worth of your investment. As always, the guiding mission of Autism Speaks is to improve the lives of all who struggle with autism.
You can explore more of the fellowship projects we’re funding here.