Inflammation Linked to Alzheimer's Disease Development

A study published in Nature found clear evidence of a direct connection between inflammation and the development of Alzheimer's disease, reports ScienceDaily . A protein known as IFITM3 that plays a role in the immune response to pathogens also is involved in the buildup of beta-amyloid in plaques. The researchers learned that IFITM3 changes the activity of an enzyme called gamma-secretase, which segments precursor proteins into the fragments of beta-amyloid that constitute plaques. The protein's removal decreased the enzyme's activity, and reduced the number of plaques that formed in a mouse model of Alzheimer's. The implication of these findings is that viral and bacterial infections could elevate the risk of Alzheimer's development, as the concentration of IFITM3 in human brain samples correlated with levels of certain viral infections and with gamma-secretase activity and beta-amyloid production. Moreover, the levels of both inflammatory markers and IFITM3 rose with advancing age in mice. In addition, IFITM3 increased in a subset of late onset Alzheimer's patients, suggesting the protein could find use as a biomarker to identify a subset who might benefit from therapies that target it.