Blood-brain barrier failure may help drive Alzheimer’s

Disruption of the blood-brain barrier’s protein transport system may contribute to Alzheimer’s disease in its early stages, ERR reports, citing a new study in mice.

Researchers in the United States, led by scientists at the Gladstone Institutes, developed a chemical labelling method to track which blood proteins cross the barrier into the brain of living mice. They identified nearly 100 proteins, each of which appeared to have a specific target in the brain.

In mouse models of Alzheimer’s, the transport system began to falter early in the disease, before the barrier physically broke down. The researchers found that less of a protective protein produced by the liver was reaching the brain.

In a healthy brain, the protein helps supporting brain cells remove excess cholesterol, a process needed to keep connections between nerve cells healthy. When the researchers increased production of the protein in the livers of affected mice, more of it reached the brain. The mice’s supporting brain cells returned to normal metabolism, their spatial memory improved and their disease-related hyperactivity eased.

The researchers reported their findings in the journal Cell.