Investigators have uncovered a molecular mechanism that links the susceptibility gene for Alzheimer’s to the process of the disease’s onset.
Research led by scientists at the Oklahoma Medical Research Foundation discovered that ApoE4 along with other apolipoproteins attaches itself to a particular receptor on the surface of brain cells. That receptor, in turn, adheres to a protein known as amyloid precursor protein. The brain cells then transport the entire protein mass inside.
Once inside, proteases attack the amyloid precursor protein. This creates protein fragments that, when present in the brain for long periods of time, are believed to cause the cell death, memory loss, and neurological dysfunction characteristic of Alzheimer's.
While roughly one in seven people carry the E4 gene, the remainder of the population carry only two variations, E2 and E3. These individuals have a markedly lower incidence of Alzheimer's than those who carry the E4 gene. The new study also found that ApoE4 produced more protein fragments than E2 or E3 did.
The findings appear in the April 11 issue of The Journal of Neuroscience.