Oxidized cholesterol species as signaling molecules in the brain: diabetes and Alzheimer's disease.

Type 2 diabetes is associated with adverse central nervous system effects, including a doubled risk for Alzheimer's disease (AD) and increased risk of cognitive impairment, but the mechanisms connecting diabetes to cognitive decline and dementia are unknown. One possible link between these diseases may be the associated alterations to cholesterol oxidation and metabolism in the brain. We will survey evidence demonstrating alterations to oxysterols in the brain in AD and diabetes and how these oxysterols could contribute to pathology, as well as identifying research questions that have not yet been addressed to allow for a fuller understanding of the role of oxysterols in AD and diabetes.