Parkinson’s Research Surges Ahead

by Denis Storey
July 2, 2024 at 10:04 AM UTC

Parkinson’s research has been progressing rapidly, revealing a link to anxiety and the potential protective role of the GUCY2C receptor.

Clinical relevance: Parkinson’s research has advanced significantly, with notable discoveries made before the passage of the National Plan to End Parkinson’s Act in late May.

  • A study found that individuals over 50 with new-onset anxiety have twice the risk of developing Parkinson’s.
  • Researchers identified the GUCY2C receptor as a potential defense against dopamine neuron loss in Parkinson’s patients.
  • These findings suggest that targeting GUCY2C could slow Parkinson’s progression and that its levels might serve as an early biomarker for the disease.

Parkinson’s research has been accelerating even before Congress passed the “National Plan to End Parkinson’s Act” in late May. A rare act of unity from a chronically divided legislature.

“As we eagerly await the bill to be signed into law, we applaud members of Congress for their bipartisan support and recognition of one of the most pressing healthcare issues of our day,” Parkinson’s Foundation President and CEO John L. Lehr said in a press release.

Even so, it’s been a busy – and enlightening – summer of research results for anyone living with Parkinson’s.

Study Exposes Link Between Anxiety and Parkinson’s

A paper in the British Journal of General Practice reveals that the risk of developing Parkinson’s is twice as high for those with anxiety.

A team of researchers at the University College of London Institute of Neurology, led by Professor Anette Schrag, combed through the primary care data of nearly 1 million patients in the United Kingdom between 2008 and 2018. Specifically, the researchers sought out the nearly 110,000 patients who developed anxiety after the age of 50. They then compared them to 878,256 matched controls without anxiety.

Subsequently, the study’s authors tracked the presence of the disease’s features, from trouble sleeping to balance impairment, “from the point of their anxiety diagnosis up until one year before the date of a Parkinson’s diagnosis, to help them understand each group’s risk of developing Parkinson’s over time and what their risk factors might be.”

“Anxiety is known to be a feature of the early stages of Parkinson’s disease, but before our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown,” the paper’s co-lead author, Juan Bazo Alvarez, MD explained. “By understanding that anxiety and the mentioned features are linked to a higher risk of developing Parkinson’s disease over the age of 50, we hope that we may be able to detect the condition earlier and help patients get the treatment they need.”

The researchers also confirmed that symptoms such as depression, sleep disturbance, fatigue, cognitive impairment, hypotension, tremor, rigidity, balance impairment, and constipation, are risk factors for anxiety sufferers.

“Anxiety is not as well researched as other early indicators of Parkinson’s disease,” co-lead author and UCL Queen Square Institute of Neurology Professor Anette Schrag added. “Further research should explore how the early occurrence of anxiety relates to other early symptoms and the underlying progression of Parkinson’s in its early stages. This may lead to better treatment of the condition in its earliest stages.”

The Body Already Has A Defense Against Parkinson’s?

More recently, a new study sponsored by the Parkinson’s Foundation appears to have identified the brain receptor GUCY2C as a potential target for mitigating dopamine loss in Parkinson’s patients.

Researchers already knew that the decay of dopamine-producing neurons – vital in movement and mood regulation – is to blame for the development of the degenerative disorder. Mitochondrial dysfunction contributes to this neuronal death.

Related research had shown that GUCY2C, initially found in the gut, is also present in the substantia nigra pars compacta (SNpc).

The new research, led by Scott Waldman, MD, digs deeper into GUCY2C’s role in protecting mitochondria and preventing neuron degeneration in the first place. In Parkinson’s patients, dopamine neurons exhibit an increased number of GUCY2C receptors.

Waldman’s experiments with mice showed that the absence of GUCY2C led to mitochondrial dysfunction, oxidative stress, and cell death in brain areas plagued by Parkinson’s. When exposed to a toxin that induces PD symptoms, mice lacking GUCY2C had higher rates of dopamine neuron death. On the other hand, mice with GUCY2C showed an increased production of the receptor, illustrating its defensive role.

These findings suggest the body’s increase in GUCY2C in those with the disease might be a natural defense against neuronal damage. Targeting GUCY2C or enhancing cGMP levels could be therapeutic strategies to protect dopamine neurons, potentially slowing PD progression.

The study also indicates that GUCY2C levels could serve as an early biomarker for Parkinson’s. While developing GUCY2C-targeted treatments will take time, this research opens new avenues for Parkinson’s therapies.

Further Reading

Blood Test Offers Parkinson’s Early Warning System

How Two Sisters May Change Our Understanding of Parkinson’s Disease

3 Key Updates in Parkinson’s Disease

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