Alzheimer’s is the most common form of dementia. According to the Alzheimer’s Association, as of 2015, 5.3 million Americans are currently living with Alzheimer’s. As the sixth leading cause of death in the United States, it is the only top 10 cause of death that cannot be prevented, cured, or slowed. Alzheimer’s research is vital if we are ever going to find proper treatments and, hopefully, a cure.
Possible New Cause of Alzheimer's Discovered
A study recently conducted by Duke University claims to have discovered a possible new cause of Alzheimer’s that could be targeted with drug treatments. The study used mice and focused on the immune system and its connection to Alzheimer’s. Previous research has looked into possible Alzheimer’s connections to the protein amyloid. This time, researchers looked at the amino acid known as arginine. Until this study was done, the role of the immune system and arginine in Alzheimer’s was unknown.
Arginine aids in many different bodily processes. It helps to widen and relax blood vessels and arteries, helping to increase blood flow. It helps the body to heal injuries, helps the kidneys to remove waste, and of course, boosts immune system response. Arginine is found in many foods. Lean meats, dairy, nuts, soy beans, chickpeas, and lentils are just some of the foods that contain high levels of arginine.
Researchers at Duke found that, in mice with Alzheimer’s, immune cells that normally protect the brain end up consuming large amounts of arginine. Using the drug difluoromethylornithine (DFMO), which is already being used in drug trials against many types of cancer, such as colorectal cancer and neuroblastomas, researchers were able to block the immune response to arginine and, in turn, prevented the plaques that are characteristic of Alzheimer’s from forming on parts of the brain. Researchers were also able to stop memory loss in the mice. The possibility of new drug trials against Alzheimer’s is promising and could help to boost funding for Alzheimer’s research.
Link Between Sleep Problems and Alzheimer's
Previous research done at Washington University in Saint Louis has found that sleep loss contributed to the growth of the brain plaques that are associated with Alzheimer’s disease. Now, scientists at Washington University are focusing on a protein called orexin, which is the protein that rouses the brain from sleep. By eliminating the protein orexin in mice, scientists have been able to slow the growth of plaques in the mice’s brains.
An upcoming study at the Brain Institute at Oregon Health & Science University hopes to use the Washington University sleep and brain research to officially define the relationship between lack of sleep and Alzheimer’s. We know that people with Alzheimer’s have trouble sleeping, but researchers at OHSU believe that instead of Alzheimer’s causing sleep problems, the reverse might be the case. It is possible that poor sleep patterns may help pave the way for Alzheimer’s.
According to the researchers at OHSU, they know that, during sleep, the brain goes through a sort of cleansing process in what is known as the glymphatic system. During this cleansing, cerebrospinal fluid begins to circulate throughout the brain and clears out the toxins that cause the growth of Alzheimer’s plaques. Researcher Jeffrey Iliff says, “That suggests at least one possible way that disruption in sleep may predispose toward Alzheimer's disease.” If the body is not falling into a deep sleep, the brain cannot flush out the toxins as it normally would.
Mice are already being tested using a sophisticated microscope. The OHSU researchers hope to start testing on people soon using a very sensitive MRI machine that can detect changes in the glymphatic system. Researchers hope to find a definitive connection between lack of sleep and the formation of Alzheimer’s plaques so that it becomes easier to identify the people who are more likely to get Alzheimer’s. Knowing how to pinpoint the people who are at a higher risk of developing the disease can also help scientists find ways to lower a person’s chances of developing Alzheimer’s.
Special Ultrasound Treatment Restores Memory Function
The protein amyloid is certainly still an important part of Alzheimer’s research. The plaques that form on the brain in a person with Alzheimer’s are made up of either amyloid plaques or of neurofibrillary tangles, which are found inside the neurons of the brain. Researchers at the Queensland Brain Institute at the University of Queensland in Australia recently published a study in Science Translational Medicine about a non-invasive way they have found that clears the brain of these plaques.
By using a specific type of ultrasound called a focused therapeutic ultrasound, researchers at QBI were able to beam sound waves into the brain and activate the brain’s waste-removal cells, the microglial cells. These cells are responsible for clearing out the toxins that form the amyloid plaques. After using this technique on mice, researchers reported that they were able to restore full brain function to 75% of the mice that were tested, with no damage at all to the mice’s surrounding brain tissue. After treatment, the mice’s performance improved in several test tasks, such as a maze, a test that tried to get them to recognize new objects, and a test that tried to make them remember places that they should avoid.
This study has not found the cause of Alzheimer’s or a way to prevent it, but the promise of a treatment that is very effective is extraordinary. The team at QBI plan on testing larger animals next, such as sheep. They hope to start human trials in 2017.