Years before Parkinson’s disease causes telltale symptoms like involuntary tremors, it is quietly wreaking havoc inside the body. And a group of Queen’s undergraduate students has developed a molecule they hope could one day halt the progression of the disease before severe symptoms ever emerge.
More than 100,000 Canadians are living with Parkinson’s today. In the fall of 2024, the Queen’s Genetically Engineered Machine (QGEM) team earned a silver medal at the prestigious International Genetically Engineered Machine (iGEM) competition in Paris for developing a molecule they hope could stop the accumulation of a protein that might be the cause of the neurological disease. And that protein is found in a very unexpected part of the body: the intestines.
Parkinson’s tremors are caused by a lack of dopamine, which communicates movement from the brain to the rest of the body. Dopamine is a neurotransmitter – a type of chemical messenger essential to the function of brain and body – and Parkinson’s damages the brain cells that produce it. But even though Parkinson’s affects the brain, it doesn’t necessarily begin there.
“It is still a controversial idea that a neurological disease could be connected to the intestines, but there is some evidence to support it,” says Mariam El-Behiry, an undergraduate biochemical engineering student and the director of the QGEM team.
A group of Queen’s undergraduate students has developed a molecule they hope could one day halt the progression of Parkinson’s disease before severe symptoms ever emerge.
The gut hypothesis centres on the connection between the brain and the intestines. There, the body makes a protein called alpha-synuclein. Like other proteins, alpha-synuclein is made of amino acids – chains of organic molecules that are the building blocks of all life. Amino acids become proteins through a process called folding, a chemical reaction through which the linear chains of amino acids transform into the shape of the three-dimensional protein. The gut hypothesis posits that an error in protein folding causes excess alpha-synuclein to accumulate in clumps called Lewy bodies. These clumps travel to the brain along the vagal nerves, which control bodily functions like digestion. In the brain, the Lewy bodies wreak havoc, damaging brain cells that control movement and balance, and causing non-motor symptoms like anxiety or memory problems. Ultimately, the disease they cause is fatal.
Though the hypothesis is still unproven, QGEM’s 29-member team of undergrads used it as a starting point for their entry into this year’s iGEM competition. The prestigious global synthetic biology competition brings together more than 400 teams of students who apply engineering principles to biological systems, with the aim of developing biotechnologies that work in harmony with nature and tackle global challenges.
With guidance from Christopher Lohans, associate professor of biomedical and molecular sciences, the QGEM team designed a protein that stops the folding errors that occur in the formation of the alpha-synuclein protein. The ultimate goal is to stop disease progression before the Lewy bodies ever reach the brain, delaying or even preventing the onset of the most severe symptoms of Parkinson’s. Currently, no treatment does anything like that.
“Neurologists tell us that even identifying people with early-stage Parkinson’s disease is a challenge,” says Ms. El-Behiry. “It can manifest in so many ways before motor symptoms appear, like gut dysfunction or insomnia. All diagnosis for Parkinson’s disease is made by clinical examination. There is no way to do that before symptoms like tremors appear, but tests are under development and, one day, it might be possible to diagnose – and treat – Parkinson’s earlier in the disease’s progression.”
