Of all the ailments Ronald Reagan has suffered, none seems as grim as his recent diagnosis of Alzheimer's disease. Yet Reagan's sad news comes just as researchers are unlocking the secrets of this terrible malady, and they are beginning to hope they will find ways to cure or even prevent the disease. The most recent and promising work flows from the lab of Allen Roses and Warren Strittmatter and their team at Duke University, who found that the ravages of Alzheimer's are linked to a form of a protein known as ApoE (short for apolipoprotein E). Mounting evidence shows that ApoE fails to protect the internal structures of nerve cells from damage, and that leads to their destruction.
Recent experiments have placed ApoE at another scene of devastation in the brains of Alzheimer's victims. In a paper published earlier this month in Nature, a team led by Harvard neuroscientists Huntington Potter and Leonard Scinto showed that ApoE may also play a principal role in the appearance of lesions, or plaques, that litter the brains of Alzheimer's victims. In the Alzheimer's brain, says Potter, ApoE and another molecule, called ACT, are transformed from good citizens of the body into "pathological chaperones." These bad actors bring together smaller proteins into tough, fibrous chains that make up plaques -- and that are now known to be toxic to nerve cells. Understanding the link between ApoE, ACT and these chains could lead to drugs that interfere with their pathology.
Diagnosis. Another finding of Potter's may soon help to diagnose Alzheimer's. Dozens of other ailments, including stroke, can masquerade as Alzheimer's dementia, so diagnosis is difficult. Potter has devised a simple test based on his finding that the eyes of Alzheimer's patients are keenly sensitive to a drug used to dilate the pupils. Just one one-hundredth of the normal concentration of a drug used in eye exams widens the pupils of Alzheimer's patients. If the test proves valid, it could one day predict who will get Alzheimer's long before symptoms appear. That would allow researchers to gauge the capacity of new drugs to slow or even halt the disease's onslaught.
The speed of the hunt for tests and cures depends on funding. "There are many good projects that we cannot fund," says Zaven Khachaturian, chief of Alzheimer's research at the National Institute on Aging. Alzheimer's strikes 1 in 12 Americans over 65, 1 in 3 over the age of 80, and costs Americans $82.7 billion a year in medical expenses and lost productivity. The annual federal research budget for Alzheimer's is $310 million, a fraction of the funds devoted to other killers such as cancer and AIDS. Beyond raising the public's awareness of this scourge, Reagan's candor might mobilize others to press for more Alzheimer's research.
