It is estimated that 44 million people worldwide suffer from some form of dementia, and the number of people diagnosed, as well as those caring for them, is ever-increasing. A recent breakthrough in Alzheimer’s research, which has been dubbed “Alzheimer’s in a Dish”, offers new hope as a quick, easy and inexpensive way to test thousands of pharmaceuticals used for treatment of the disease.
“Alzheimer’s in a Dish” is the formation and growth of human brain cells that exhibit the signs and symptoms of Alzheimer’s disease within a gel-filled petri dish. Dr. Doo Yeon Kim, co-senior author on the paper, was inspired by the brain’s jelly-like consistency when he came up with the idea to grow human stem cells in a 3D gel matrix. The research team at Massachusetts General Hospital, led by Dr. Rudolph Tanzi, successfully grew human stem cells that were mutated to create amyloid plaques in six weeks. Two to four weeks later, the cells developed tangles and resembled that of a human brain with Alzheimer’s.
Dr. Tanzi says that there are three tell-tale stages of Alzheimer’s that work in a cyclical manner. Amyloid plaques build up outside neurons, which then cause tangles inside these same neurons, leading to inflammation of the cells in the brain and causing the cycle to repeat. Because these three components work together, preventing one step has the potential to disrupt the entire process. With this new model, testing how drugs interfere with each stage is easier than ever before.
While it is true in most cases of Alzheimer’s that amyloid plaques appear first, thereby causing tangles and starting the disease process, it is still possible to trigger the cycle by beginning in any of the three stages.
A caveat of “Alzheimer’s in a dish” is that while it recapitulates the building process of amyloid plaques to tangles, inflammation is not evident. By definition, all three stages of the cycle, including inflammation, are required to form Alzheimer’s. Some autopsy cases of individuals who did not display symptoms of dementia reveal that their brains contained amyloid plaques and tangles but did not exhibit signs of inflammation. The research team is in the process of creating a second dish model that exhibits inflammation.
Regardless, this new model shows promise. Dr. Tanzi and his team are aiming to test 1,200 drugs that are currently on the market and 5,000 experimental drugs that have completed the first phase of clinical testing, all within a matter of months. There is still a long way to go before finding a cure for Alzheimer’s, but with breakthroughs like this one, we get closer and closer.