Stanford University researchers have developed a new map of the human epigenome, which controls gene expression — like a traffic light —across different cells types and integrates genetic and environmental signals. The development is significant for Alzheimer’s disease as the researchers say that their work indicates that the body’s immune system may play a role in the illness.
While the human genome, which are genes contained in DNA, had already been mapped, the epigenome, which gives signals as to whether a gene is active or not in a cell, had not, until now. The epigenetic processes that have now been mapped — and that occur in more than 100 different cell types — could spur development of drugs that can undue actions that impact genes that lead to diseases.
Anshul Kundaje, an assistant professor of genetics and computer science at the university, and colleagues found that genetic mutations related to Alzheimer’s in mice were found in both immune cells as well as neurons in the brain, they reported in the journal Nature. This could be an indication that Alzheimer’s impacts not only neural activity in the brain, but the immune system as well, study co-author Manolis Kellis, PhD, a molecular biologist at the Massachusetts Institute of Technology, told The Verge.
“Our analysis provides convincing evidence that Alzheimer’s disease has a strong immune component that contributes to neurodegeneration, in which mutations strongly affect regulatory regions of cells responsible for removing potentially damaging plaques from the brain,” Kundaje said in a news release issued by Stanford.
While researchers have been able to identify mutations that cause disease, it’s hasn’t always been clear in which cell types in the body the mutations manifest themselves. But now, they can match up the mutations with the epigenomic maps to identify cell types and tissues in which the mutation are likely to affect regulation of genes and negatively impact cellular function.
Kundaje A, et al. Conserved epigenomic signals in mice and humans reveal immune basis of Alzheimer’s disease. Nature. 2015; doi:10.1038/nature14252.