January 28, 2022

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease that destroys memory and other important mental functions. AD affects more than 44 million people worldwide and more than six million Americans. Given this prevalence, studying AD is a high priority, and researchers have been searching for better ways to learn more about the disease.

Now, researchers at the Wisconsin National Primate Research Center and other institutions at UW-Madison have shown rhesus monkeys can be a new, translational model for studying late-onset Alzheimer’s disease. “Age is a major risk factor for late-onset Alzheimer’s disease (AD) but seldom features in laboratory models of the disease,” the researchers write in the scientific publication Aging Cell.

The researchers studied brain tissues from transgenic mice, old monkeys with age-related amyloid plaques and post-mortem brain tissue from donors who were aged 72 to 96 and diagnosed with AD after death. This approach provides an alternative to the most common approaches to modeling AD, which tend to use young mice in which plaques and tangles are genetically imposed and seldom include age as part of the study design.

The new study design, however, shows the aged environment impacts inflammatory processes linked to neurodegeneration. In the monkeys and humans, where plaques develop as a function of age, each demonstrated differences from mice in the immediate vicinity of amyloid plaques, but were similar to each other.

In all three species, the authors discovered new structures enriched in mitochondria surround the plaques, and the presence of these plaques influences metabolism. In the monkeys and humans, said Dr. Ricki Colman of the WNPRC, “this mitochondrial dysfunction appears to be suggestive of Alzheimer’s disease.”

The published study concludes that, given the clear parallels between amyloid plaques in monkeys and humans, further studies in nonhuman primate models are warranted. Monkey models are more likely to translate to human disease than mouse studies and could help advance treatments for AD.


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