We know that Alzheimer's disease is linked to ageing, in that the elderly are most susceptible to experiencing the disorder, but just how deep are the ties?
A new study by researchers in the US explains more about the relationship between ageing and Alzheimer's, with continued testing of an experimental drug candidate called J147 revealing unforeseen benefits in the latest research. In testing on rodents, the drug surprised researchers by showing unexpected anti-ageing effects on mice.
When the animals were treated with J147 they showed better memory and cognition, healthier blood vessels in the brain, and other improved physiological features.
"Initially, the impetus was to test this drug in a novel animal model that was more similar to 99 percent of Alzheimer's cases," said Antonio Currais, a researcher in the Cellular Neurobiology Laboratory at the Salk Institute for Biological Studies in California. "We did not predict we'd see this sort of anti-ageing effect, but J147 made old mice look like they were young, based upon a number of physiological parameters."
J147 takes a different approach to many other drugs developed to combat Alzheimer's disease. "While most drugs developed in the past 20 years target the amyloid plaque deposits in the brain (which are a hallmark of the disease), none have proven effective in the clinic," said David Schubert, senior author of the study. Instead, the treatment focuses on what the researchers say is the most obvious major risk factor for the disease: old age.
J147 was initially synthesised by using cell-based screens against old-age-associated brain toxicities. In the latest study, the researchers tested the efficacy of the treatment by tracking the progression of three groups of rapidly ageing mice. One group were young mice, one were old mice, and the final group were old mice on a diet which included J147.
In a set of experiments designed to test the animals' memory, cognition and motor movements, the old mice fed J147 showed better performance and also displayed fewer pathological signs of Alzheimer's disease in their brains. Further, many aspects of the J147-fed mice's gene expression and metabolism – including increased energy metabolism, reduced brain inflammation and reduced levels of oxidised fatty acids in the brain – were similar to that of the younger mice.
Less leakage of blood from the microvessels in the brain was another bonus stemming from the drug. "Damaged blood vessels are a common feature of ageing in general, and in Alzheimer's, it is frequently much worse," said Currais.
The research, which is published in Aging, is set to continue in 2016, with the first human trials hoped to replicate these exciting effects so far seen in rodents. "If proven safe and effective for Alzheimer's, the apparent anti-ageing effect of J147 would be a welcome benefit," said Schubert.