A New Cause of Alzheimer's?

By Jane Farrell

Blocking a key brain–cell receptor may eventually lead to neutralizing some consequences of Alzheimer’s, according to a new study from Temple University.

The brain cells are used by “oxygen free radicals” that are linked to “oxidative stress.”  That “stress” occurs when the production of the free radicals is greater than the body’s ability to detoxify them.

Researchers have known for a while that oxidative stress is linked to Alzheimer’s along with amyloid beta plaques and the protein tau.

“But it has always been believed that oxidative stress was just a bystander and did not have an active function in the development of the disease,” said study leader Domenico Praticὸ, professor of pharmacology and microbiology and immunology in Temple’s School of Medicine.

The Temple investigators found that the free radicals produced from oxidative stress bind to a brain-cell receptor called the thromboxane receptor, or TP. They then signal the brain cells to increase the production of amyloid beta or tau.

“Basically, it sends the wrong message inside the neuronal cells, and with time, this definitely will result in all the clinical manifestations of the disease, such as cognitive impairment, loss of memory and brain cell death,” Praticὸ said.

In their study, the researchers introduced free radicals into the brain of a mouse, and saw the resultant worsening of its memory and learning capabilities. But when the brain-cell receptor was blocked, there was no cognitive impairment.

Praticὸ said that the findings implicating oxidative stress and the TP receptor open an important chapter for Alzheimer’s treatment. “For the first time we have identified this receptor as the culprit responsible for the bad things that happen with the disease when high levels of oxygen free radicals are produced.”

The findings were published in the journal Neurobiology of Aging.