“Each vesicle has a novel molecular signature on its surface, including proteins that offer you clues about its origin,” Martens said. “In our case, we chosen vesicles that carry markers which are characteristic of neurons, and so we have now confidence that the NAD+ we measured in them reflects what happens within the neurons and by extension the brain.”
Using samples from their first initial clinical trial, they found that levels of NAD+ increased in vesicles roughly six weeks after ingesting NR. “When NAD+ goes up in these vesicles, we see an association with a number of the biomarkers of neurodegenerative disease,” Martens said. “Particularly, in people where we saw a rise in NAD+, we also saw changes in biomarkers like amyloid beta and tau, that are each related to Alzheimer’s disease.”
In addition they found a correlation between these neurodegenerative biomarkers and changes in NAD+. “If NAD+ went up rather a lot, there was typically a bigger change in a number of the disease biomarkers,” Martens said. “That tells us the NAD+ will not be only stepping into the brain however it’s likely also having some effect on its metabolism and multiple interrelated pathways.”
The team hopes these recent blood-based biomarkers will help reveal if NAD+ depletion causes Alzheimer’s or other neurodegenerative disorders and even open the door to providing a reliable approach to test for difficult-to-diagnose diseases.