Exosomes—nanoscale particles that are produced by all types of cells and circulate in the bloodstream—have proven to be reliable markers for the effectiveness of an experimental drug for Parkinson’s disease (PD) in a new study. The research, jointly led by investigators from the NIA Intramural Research Program and colleagues from the United Kingdom, was published in the Jan. 14 issue of JAMA Neurology.
Exosomes originating from neurons carry an information-rich cellular cargo and can cross the blood-brain barrier. Several previous studies have demonstrated that it’s possible to track key disease-related proteins within this exosome cargo and that this technique can successfully differentiate between healthy control samples and those from patients with Alzheimer’s or Parkinson’s.
In this study, the NIA team examined neuronal exosomes found in blood serum samples from 60 participants in the Exenatide-PD trial, which was conducted in the United Kingdom. Exenatide, an experimental drug of a type commonly used to treat diabetes, has shown promise for improving motor function and potentially protecting against PD, and other neurological diseases.
Patients with PD who received regular exenatide injections showed higher levels of active forms of brain insulin signaling proteins and related mechanisms in their exosomes over time compared with their baseline measurements and those of participants who received a placebo. The patients on exenatide also showed improvements in motor function tests for PD compared to those in the control group, and these improvements were found to correspond to changes in exosome proteins.
This study confirms the value of exosomes as an additional analytical tool to show target engagement in clinical trials. The investigators are optimistic about future work to examine how exosomes could help speed up validation in clinical trials of potential new drugs for PD, Alzheimer’s disease, and other neurological disorders.
Source – National Institute on Aging