mouse study offers hope for gene therapy for Parkinson’s disease | Health Info

By Robert Preidt, Health Day reporter

THURSDAY, November 4, 2021 (HealthDay News) – An experimental gene therapy to increase the effectiveness of the Parkinson’s disease drug levodopa has shown promising results in mice, researchers report.

As the loss of dopamine-releasing neurons progresses to advanced Parkinson’s disease, levodopa is less able to relieve movement problems caused by the disease, which is a progressive disorder of the nervous system.

But a team from Northwestern University found that gene therapy targeting the region of the brain in mice where these neurons are located dramatically increased the benefits of levodopa.

Gene therapy did this by restoring the ability of neurons to convert levodopa to dopamine, the researchers said. However, animal research does not always bear fruit in humans.

Along with their findings on gene therapy, the researchers offered new insight into why dopamine-releasing neurons are lost in patients with Parkinson’s disease.

In mice, researchers found that damage to mitochondria (powerhouses) in dopamine-releasing neurons triggers a sequence of events that mimics what happens to brain circuits in Parkinson’s disease.

The results can help identify people in the early stages of Parkinson’s disease and lead to therapies to slow disease progression and treat late-stage disease.

“Developing effective therapies to slow or stop the progression of Parkinson’s disease requires scientists to know what causes it,” said study author D. James Surmeier, president of neuroscience at Northwestern’s School of Medicine.

“This is the first time that there is definitive evidence that damage to mitochondria in dopamine-releasing neurons is sufficient to cause human-like parkinsonism in a mouse,” he said in a statement from university press.

“The question of whether mitochondrial damage was a cause or a consequence of the disease has long been debated,” Surmeier noted. “Now that this issue is resolved, we can focus our attention on developing therapies to preserve their function and slow the loss of these neurons.”

The study also provides a model of Parkinson’s disease before symptoms appear.

“This new ‘human-like’ model could help us develop tests that identify people who are about to be diagnosed with Parkinson’s disease in five or 10 years,” Surmeier said. “This would allow us to launch them early on therapies that could alter the progression of the disease. “

The results were published on November 3 in the journal Nature.

SOURCE: Northwestern University, press release, November 3, 2021

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