ApoE Isoform Effects on Cerebral Insulin Signaling in Alzheimer's Disease

The APOE gene codes for the apolipoprotein E, a protein that usually helps transport fats into cells. The three most common variations of this gene are the e2, e3 and e4. People who inherit the variation APOE-e4 are at an increased risk for Alzheimer's. While the exact reasons for this heightened risk are unclear, some investigators have found that APOE-e4 may suppress the brain's ability to produce energy - a problem that can lead to brain cell damage, loss of memory and other cognitive functions. For their preliminary research, Dr. Na Zhao and colleagues have studied mice engineered to have the APOE-e4 gene variation. They found that the rodents' brains showed impairments in the ability to use insulin, a hormone involved in producing energy from sugar. Moreover, because the e4 gene is also linked to brain processes involving beta-amyloid (a key suspect in Alzheimer's), APOE-e4 and beta-amyloid may work together to hinder insulin