Experimental drug may soon make dementia history

Washington: Scientists have developed new drugs that - at least in a laboratory dish - seems to stop the brain-destroying impact of a genetic mutation at work in some forms of two incurable diseases, amyotrophic lateral sclerosis (ALS) and dementia.

Jeffrey D. Rothstein, M.D., Ph.D., a professor of neurology and neuroscience at the Johns Hopkins University School of Medicine, said with this iPS technology, they believe think they can target an exact subset of patients with a specific mutation and succeed. It's individualized brain therapy, just the sort of thing that has been done in cancer, but not yet in neurology.

Scientists in 2011 discovered that more than 40 percent of patients with an inherited form of ALS and at least 10 percent of patients with the non-inherited sporadic form have a mutation in the C9ORF72 gene.

Rothstein said that in a series of experiments they discovered that in iPS neurons with the mutation, the process of using the DNA blueprint to make RNA and then produce protein is disrupted.

Normally, RNA-binding proteins facilitate the production of RNA. Instead, in the iPS neurons with the C9ORF72 mutation, the RNA made from the repeating GGGGCC strings was bunching up, gumming up the works by acting like flypaper and grabbing hold of the extremely important RNA binding proteins, including one known as ADARB2, needed for the proper production of many other cellular RNAs.

Overall, the C9ORF72 mutation made the cell produce abnormal amounts of many other normal RNAs and made the cells very sensitive to stress.

To counter this effect, the researchers developed a number of chemical compounds targeting the problem. This compound behaved like a coating that matches up to the GGGGCC repeats like velcro, keeping the flypaper-like repeats from attracting the bait, allowing the RNA-binding protein to properly do its job.

The study has been published online in the journal Neuron.