April 20, 2021

Alzheimer’s disease (AD) affects more than 5.5 million Americans per year. This staggering prevalence makes it a high-priority disease for researchers to develop better treatments and even a cure. Researchers at California’s National Primate Research Center (CNPRC) are among those pursuing answers and believe the disease actually begins decades before the first signs of cognitive decline are triggered. 

Until recently, testing has primarily been done on transgenic mice that express a human version of amyloid or tau proteins, but these studies have proven to be difficult to translate into new medications for the human population. In contrast, nonhuman primate (NHP) models may yield new treatments by providing a closer biological link between the laboratory and clinic. 

“Humans and monkeys have two forms of the tau protein in their brains, but rodents only have one,” said Danielle Beckman, postdoctoral researcher at the CNPRC and first author on the paper. “We think the macaque is a better model, because it expresses the same versions of tau in the brain as humans do.”

Beckman and her team recommend adding an intermediate step for translational research: “If we can test therapies that work in mouse models prior to investing millions or billions of dollars into clinical trials, we really think it’s going to make an impact in having a new drug on the market. I think we really need to be open about new animal models for diseases.”

Visualization of biomarkers in the brain of NHP models may provide the key into the progression of Alzheimer’s disease. So far, teams have monitored signs of neuron death and performed positron emission tomography imaging. The effects of neurodegeneration were observed rapidly; within three months, end-stage tangles were present. And within 6 months, the progress of neurodegeneration increases markedly.

While it is still unknown whether the treated animals will present the full spectrum of Alzheimer’s Disease, including severe cognitive impairment, the initial observations have set the stage for the next steps in testing tau‐based therapeutics for AD patients. Research with monkeys is again proving critical to finding answers that can improve millions of lives worldwide. 

To learn more about the work happening at our research centers around the country, visit this link

Back to top