Blood tests show that Parkinson's patients have trouble recycling energy in their cells

A recent study by researchers from Fujita Health University has uncovered new clues about the metabolic problems faced by PD patients. By examining the blood and spinal fluid of these patients, they found significant disruptions in energy production and purine metabolism, which is linked to the recycling of ATP—a key molecule for energy in cells. For years, scientists have noticed lower levels of uric acid, a natural antioxidant, in PD patients. Initially, it was thought that uric acid helped protect the brain by reducing harmful oxidative stress. However, this new study, published in NPJ Parkinson’s Disease on September 9, 2024, reveals that the situation is more complicated. Lead researcher Dr. Watanabe explains, "Our findings show that low uric acid levels in PD patients are influenced by more than just purine metabolism. Factors like sex, weight, and age also play a role, suggesting that the connection between uric acid and PD is not only about oxidative stress." Using a technique called targeted metabolomics, the team analyzed various purine metabolites, including inosine, hypoxanthine, xanthine, and uric acid. They discovered that PD patients had much lower levels of uric acid in both their blood and spinal fluid compared to healthy individuals. They also found reduced levels of hypoxanthine, another key purine compound. Interestingly, the study showed that these reduced uric acid levels were linked to body weight and sex, but not to xanthine, an upstream metabolite in the purine pathway. This finding challenges previous beliefs about how purine metabolism works in PD patients. This research highlights a critical malfunction in the ATP recycling system. ATP is essential for energy use in cells, and its breakdown and recycling are vital for healthy cell function. In PD, this energy recycling system appears to be failing, contributing to the disease’s symptoms. The study also looked at inosine, which is a precursor to uric acid. While PD patients had lower inosine levels in their spinal fluid, their blood levels remained normal. Dr. Watanabe suggests this may indicate a drop in energy production within the brain itself. Additionally, the research found that PD patients had much lower levels of hypoxanthine in both blood and spinal fluid. Hypoxanthine is mostly recycled as inosine monophosphate (IMP), which plays an important role in maintaining energy production in cells. These findings about energy disruption in PD open up new possibilities for treatment. Current therapies mostly focus on managing symptoms, but this research suggests that targeting the body's energy recycling system might slow down the progression of the disease. The study also indicates that simply raising uric acid levels might not be enough to improve PD symptoms. Instead, improving ATP production and the purine recycling system could be more effective. Moving forward, the research team plans to explore how exercise and nutrition might help boost energy metabolism and ATP recycling in PD patients. In summary, this groundbreaking research brings us closer to understanding the complex metabolic changes in Parkinson’s disease. By focusing on energy production and purine recycling, scientists hope to develop new treatments that could slow the disease’s progression and improve the lives of those affected by PD.