September 20, 2015
Alzheimer’s: The New Frontier – Part III
BY Mary Mahoney
Despite the discouraging fact that Alzheimer’s disease is on the rise and that many attempts to find a cure have met with failure, renewed attention to the devastating brain disease may be yielding some promising results.
With a growing and increasingly older population in the United States and worldwide, Alzheimer’s, which primarily affects people over 65, has reached a crisis point.
Current medications only relieve symptoms temporarily, and scientists still have not pinpointed why some people get Alzheimer’s and why some don’t or why the majority affected are women. As a Medical News Today article says, “This is certainly not through lack of trying.”
Indeed, scientists recently restored memory and learning deficits in mice with Alzheimer’s. Others recognized how vitamin D deficiency could increase the risk of developing dementia. Still other researchers showed how DNA methylation in the brain is linked to Alzheimer’s.
New lines of research have opened up. Scientific American’s white paper report, “Health after 50: Memory,” covers advances and theories on Alzheimer’s including the effect of cholesterol-lowering medications, diabetes and dementia, estrogen therapy, early detection, research using stem cells, self-monitoring exercises, a vaccine to stimulate the immune system to produce antibodies against the tau protein found in Alzheimer’s patients and much more.
Studying the brain properly has been uniquely challenging. Only last year, The New York Times reported, were researchers able to grow human brain cells in a petri dish and manipulate them to develop the telltale structures of Alzheimer’s disease. The article calls this step “a real game changer” and “a paradigm shifter.”
Lead researcher Rudolph E. Tanzi of the Massachusetts General Hospital in Boston, “is now starting an ambitious project to test 1,200 drugs on the market and 5,000 experimental ones that have finished the first phase of clinical testing — a project that is impossible with mice, for which each drug test takes a year. With their petri dish system, Dr. Tanzi said, ‘we can test hundreds of thousands of drugs in a matter of months.’”
Other researchers are looking at the immune system for clues. A study in July 2015 by researchers at the University of California San Francisco and Stanford School of Medicine published in Science Daily found “a molecule, named B2M, that increases in abundance as we age, blocks the regeneration of brain cells and promotes cognitive decline.”
Scientists also discovered that connecting the circulatory system of a young mouse to that of an old mouse could reverse the declines in learning ability that typically emerge as mice age. Additionally, blood from older animals appears to contain “pro-aging factors” which can contribute to cognitive decline. “We are interested in developing antibodies or small molecules to target this protein late in life,” said study co-author Dr. Saul Villeda.
The Telegraph reported that a team at the Imperial College has discovered how to turn off an enzyme that is driving many incurable diseases including Alzheimer’s and cancer. Scientists at Ulster and Lancaster Universities found that diabetes drugs Liraglutide and Lixisenatide prevent Alzheimer’s characteristic and destructive amyloid plaques from forming in mice brains.
Other research on genetics and the immune system found a link between a rare mutation in the TEM2 gene called TREM2, which helps trigger immune system responses, and an increased risk for developing Alzheimer’s disease.
There are also new drugs in the pipeline: NitroMemantine, a combination of nitroglycerin and memantine (the latter is already used for Alzheimer’s), “appears to restore synapses — the connections between neurons — lost in the disease process,” said the author of a recent article in the Orlando Sentinel.
Calling the new research ‘very promising,’ Dr. David Smuckler, geriatrician and medical director of Orlando Health’s Center for Aging and Memory Disorder Center, said he would welcome a new treatment. “The medications we have now are not very good. A lot of patients don’t respond, but they’re the best we have,” Smuckler said. “They don’t do much to slow the process, and they definitely don’t reverse it.”
What about older people with really good memory? This year, an article in The New York Times reported results of a study of older people with “peculiar, oversize brain cells known as von Economo neurons.” There were almost five times the number of these large cells in the older people with exceptionally good memory versus the average person. Accordingly, they were dubbed the SuperAgers. No one really knows how these large neurons affect memory, but it has already become yet another starting point in the search for an Alzheimer’s cure.