Professors discuss new Alzheimer’s research
The cause of Alzheimer’s disease is uncertain, but scientists now have new theories on how the disease spreads.
Recent research explained in Nature, International Weekly Journal of Science suggests that prions, or mis-folded proteins, influence the development of Alzheimer’s.
Unlike bacteria or viruses, prions are not killed by standard sterilization procedures, which may mean that they can be passed along by contaminated surgical instruments or blood transfusions.
Jianmin Chen, an assistant research professor in the Department of Cell Biology and Neuroscience, said the complicated nature of Alzheimer’s disease means that there is no simple answer to its cause.
“There are lots of hypotheses and evidence of all different kinds of possibilities for (Alzheimer's)," she said. "We like to see a disease as simple as possible so that way we can generate a hypothesis to test it, but it’s not. In real life, it’s not that simple — it’s complex."
Since current widespread Alzheimer’s theories still involve speculation, the prion hypothesis has yet to gain momentum.
The main theory behind the development of Alzheimer’s is the amyloid hypothesis, which discusses the protein amyloid in the brain and its effect on brain function, Chen said. The growing interest in prions may lead to some branching out on Alzheimer’s research.
Karl Herrup, head of Life Sciences at Hong Kong University of Science and Technology and an adjunct professor in the Department of Cell Biology and Neuroscience at Rutgers, said researchers are too fixated on the amyloid hypothesis, and urges them to consider more possibilities.
“Could prions be an initiating factor (in causing Alzheimer’s)?" he said. "There’s no true answer to that question. Right now, prions mean something much more generic, and the idea that there might be a mis-folded protein out there doing damage, I think, is certainly an open possibility.”
Prions as disease-causing agents are not something new. They also cause mad cow disease, which fatally destroys the brain and spinal cord in bovines, according to the National Institutes of Health. Humans can develop a variant of the disease called Creutzfeldt-Jakob disease, after eating infected meat.
Alzheimer’s disease is not contagious, Herrup said. If someone with Alzheimer’s coughs on another individual, they will not get the disease like you would with the common cold, but the prion hypothesis may suggest that the disease can be passed on in other ways.
“There’s no question that the prion protein will survive most standard sterilization procedures (like used for blood transfusions)," he said. "You would have to know what that protein was before you could screen for it."
Creutzfeldt-Jakob disease has been studied for its analogies to Alzheimer’s. Neither disease has a cure, and therapies focus on treating only the symptoms, Herrup said.
There are vaccines for Alzheimer’s disease in development. Among one of the researchers for vaccine development is Hong Duck Kim, an assistant professor in the Department of Environmental Health Science at the New York Medical College School of Public Health.
The vaccine targets and destroys beta-amyloid, a protein that develops from stress and damages the brain in patients with AD, Kim said.
“Beta-amyloid or tau proteins are automatically produced by stress,” Kim said. “(The vaccine) is used to clean out (beta-amyloid) … if you do not clean (this protein) out, it will accumulate in the brain, which kills neurons in the area.”
He said that the death of neurons is what leads to memory loss in Alzheimer's patients. Since current treatments only focus on relieving symptoms of the disease and cannot reverse its effects, a vaccine that clears beta-amyloid can become a more preventive approach for it.
Established routines can also help prevent the onslaught of Alzheimer's.
“I think the best thing you can do is exercise," Herrup said. "Maintain your body’s fitness. Basically, what’s good for your heart is good for your head. And that has really stood the test of time."
He said diet may contribute to decreasing risk for Alzheimer’s. Eating foods high in omega-3 fatty acids may make a difference.
“(Alzheimer’s) is extraordinarily incredible," he said. "It’s almost like it’s the normal human condition, and the weird ones in our society are the people who don’t get it."
Editor's Note: A previous version of this story said Jianmin Chen is an associate professor in the Department of Cell Biology and Neuroscience.