VA Research Wrap Up: New findings on Agent Orange, Parkinson’s disease and opioid use

VA’s Office of Research and Development recently published three News Briefs highlighting research findings on skin cancer linked to Agent Orange exposure, Parkinson’s disease and a potential new treatment for substance use disorder.

Agent Orange linked to rare skin cancer

VA Boston researchers identified a possible link between exposure to Agent Orange and a rare form of skin cancer called acral melanoma, which appears on the palms, soles of the feet and under nails, and has a poorer prognosis than other forms of skin cancer.

In a study of nearly 8,000 Veterans, those exposed to Agent Orange had 30% higher odds of acral melanoma compared to both healthy controls and Veterans with a more common form of melanoma. While Agent Orange has been associated with risk of other forms of cancer, this is the first study to link the chemical to acral melanoma. View the full study from “JAMA Dermatology.”

Parkinson’s disease may be linked to gut bacteria

A team led by a New Mexico VA researcher found a potential causal link between gut bacteria and the development of Parkinson’s disease.

The bacteria Desulfovibrio vulgaris has been shown to be much more prevalent in the digestive tract of people with Parkinson’s disease. The researchers showed these bacteria can cause a build-up of a protein called alpha-synuclein, which has been connected to Parkinson’s when concentrated in the brain, and that the bacteria promote the release of this protein from intestinal cells into the body. They further showed a build-up of alpha-synuclein suppresses an enzyme necessary to the brain’s ability to use the neurotransmitter dopamine. The findings advance understanding of how bacteria in the gut can drive neurodegeneration and point to a possible target for early intervention in Parkinson’s disease. View the full study from “Frontiers in Neuroscience.”

Heart disease drug may help with substance use disorder

Iowa City VA researchers showed that acetazolamide, a heart disease medication, may be able to reverse opioid withdrawal and reduce drug-seeking behavior.

Using a mouse model, the researchers demonstrated how prolonged withdrawal from opioids led to alterations of the brain’s synapses related to an enzyme called carbonic anhydrase 4 (CA4). Administering acetazolamide blocked the expression of CA4, preventing the synaptic alterations that increase opioid cravings. The results suggest acetazolamide and similar drugs could be repurposed as effective non-opioid treatment for substance use disorder. View the full study from “Neuropsychopharmacology.”

For more Office of Research and Development updates, visit ORD online or go to https://www.research.va.gov/news_briefs/.