Researchers at the University of Arizona Health Sciences have discovered the potential of a protein called PNA5 in protecting brain cells, offering a promising avenue for treating cognitive symptoms associated with Parkinson’s disease and related disorders.
Parkinson’s disease is a brain disorder that causes unintended or uncontrollable movements, such as shaking, stiffness, and difficulty with balance and coordination.
The United Kingdom’s National Institute of Ageing describes it as Parkinson’s disease, which occurs when nerve cells in the basal ganglia, an area of the brain that controls movement, become impaired and/or die. Normally, these nerve cells, or neurones, produce an important brain chemical known as dopamine. “When the neurones die or become impaired, they produce less dopamine, which causes the movement problems associated with the disease. Scientists still do not know what causes the neurones to die.”
The American Parkinson Disease Association states that people with PD may experience mild cognitive impairment at the time of diagnosis or later. These changes can include Forgetfulness Difficulty concentrating Confusion Difficulty making decisions Difficulty planning and accomplishing tasks Dementia.
According to the association, about 4 in 5 patients with Parkinson’s disease develop dementia. Other cognitive changes that can occur with PD include:
Slowed thought processes; Lack of judgment Compulsive behaviours Paranoia.
Unfortunately, while medications exist to manage motor symptoms, no effective treatment is currently available for the cognitive challenges linked to the disease.
Dr Kelsey Bernard, lead author of the study, highlighted the prevalence of cognitive symptoms in patients, stating, “When patients are diagnosed with Parkinson’s disease, 25 to 30 per cent already have mild cognitive impairment. As the disorder progresses into its later stages, 50 to 70 per cent of patients complain of cognitive problems.” She emphasised the urgent need for treatments addressing cognitive decline in Parkinson’s.
Published in Experimental Neurology Journal, the team’s findings showed that PNA5 reduced inflammation and protected brain cells in mammal animal models. According to the lead author, “With PNA5, we’re targeting cognitive symptoms, but, in particular, we’re trying to prevent further degeneration from occurring.” The researchers observed a decrease in harmful inflammatory chemicals in the brain following PNA5 treatment, equating to less brain cell loss.
According to the study, microglia, immune cells in the brain, become overactive in Parkinson’s disease, releasing inflammatory substances that harm surrounding neurones, particularly in regions of the brain associated with learning and memory. PNA5 appears to moderate this overactive immune response, potentially preventing further cognitive decline.
Dr Hay, a professor of Physiology who also co-authored the study, confirmed the other uses of the PNA5 protein for other types of dementia, such as vascular dementia and Alzheimer’s disease. She and her collaborators modified a naturally occurring chemical to enhance its ability to penetrate the brain and remain active longer, a critical factor in its therapeutic promise.
While PNA5 shows potential for managing cognitive symptoms, it is unconvincing to replace existing medical treatment for Parkinson’s disease. The team’s next steps include identifying biomarkers, refining dosages, and examining sex differences in response to PNA5, aiming to pave the way for clinical applications.
