A team of Tel Aviv University researchers have identified a specific set of molecules called microRNAs that detrimentally regulate protein levels in the brains of mice with Alzheimer’s diseaseand beneficially regulate protein levels in the brains of other mice living in a stimulating environment.
“We were able to create two lists of microRNAs — those that contribute to brain performance and those that detract — depending on their levels in the brain,” says Dr. Boaz Barak, one of the authors of the study. “By targeting these molecules, we hope to move closer toward earlier detection and better treatment of Alzheimer’s disease.”
The researchers ran a series of tests on a part of the mice’s brains called the hippocampus, which plays a major role in memory and spatial navigation and is one of the earliest targets of Alzheimer’s disease in humans. They found that, compared to mice in normal cages, the mice from the living in an “enriched environment” — an enlarged cage with running wheels, bedding and nesting material, a house, and frequently changing toys — developed higher levels of good proteins and lower levels of bad proteins.
For the first time, Barak and a team of researchers in the lab of Prof. Uri Ashery of Tel Aviv University’s Department of Neurobiology at the George S. Wise Faculty of Life Sciences and the Sagol School of Neuroscience identified the microRNAs responsible for regulating the expression of both good and bad proteins.
Prof. Daniel Michaelson of TAU’s Department of Neurobiology in the George S. Wise Faculty of Life Sciences and the Sagol School of Neuroscience, Dr. Noam Shomron of TAU’s Department of Cell and Developmental Biology and Sagol School of Neuroscience, Dr. Eitan Okun of Bar-Ilan University, and Dr. Mark Mattson of the National Institute on Aging collaborated on the study, published in Translational Psychiatry.
Two findings appear to have particular potential for treating people with Alzheimer’s disease. In the brains of old mice with the disease, microRNA-325 was diminished, leading to higher levels of tomosyn, a protein that is well known to inhibit cellular communication in the brain. The researchers hope that eventually microRNA-325 can be used to create a drug to help Alzheimer’s patients maintain low levels of tomosyn and preserve brain function.
The researchers also found several important microRNAs at low levels starting in the brains of young mice. If the same can be found in humans, these microRNAs could be used as biomarker to detect Alzheimer’s disease at a much earlier age than is now possible — at 30 years of age, for example, instead of 60.
“Our biggest hope is to be able to one day use microRNAs to detect Alzheimer’s disease in people at a young age and begin a tailor-made treatment based on our findings, right away,” says Dr. Barak.