As we reported on Here & Now, this week brought news of a promising advance on Alzheimer’s disease: A study in the journal Nature that helps illuminate what goes wrong early on in the brains of people who get late-onset Alzheimer’s, the most common form. The researchers aimed to connect the dots between the gene APOE4, the strongest known genetic risk factor, and development of the actual disease.
Please read the Here & Now report for more detail, but for the bigger picture, here are some clear insights from Dr. Robert C. Green, a medical geneticist at Brigham and Women’s Hospital and Harvard Medical School. (To sum up in an adjective: Here & Now host Robin Young asked me if this was “great” news on Alzheimer’s; I only felt comfortable going as far as “promising.” Dr. Green takes it all the way to “exciting.”) His points:
“What I think is the really exciting part of it is that, for nearly 20 years, we’ve known that APOE was a robust risk factor for Alzheimer’s disease, but we really didn’t know why. And this paper is actually the first paper that begins to offer an answer as to why APOE4 is a risk factor at a molecular level.
The way they did it is quite remarkable: They did it with gene expression profiles, a hot new area, and they found that certain genes were turned up or down by the APOE4, and they were genes that appeared to regulate the production of the bad amyloid protein associated with Alzheimer’s disease. So the APOE4 didn’t directly influence the production of the amyloids; it seemed to regulate up or down these signaling genes, sort of like a cascade effect, to regulate some of the amyloid up and down. Continue reading