Researchers from John Hopkins University have developed an experimental drug, similar to compounds used to treat diabetes, that slows the progression of Parkinson’s disease in a mouse model.
The study has been published in the journal Nature Medicine.
In experiments performed with cultures of human brain cells and live mice, they report that the drug blocked the degradation of brain cells that is the hallmark of Parkinson’s disease. The drug is expected to move to clinical trials this year.
If planned clinical trials for the drug (named NLY01) are successful in humans, it could be one of the first treatments to directly target the progression of Parkinson’s disease, as opposed to the symptoms of the disorder.
NLY01 works by binding to so-called glucagon-like peptide-1 receptors on the surface of certain cells. Similar drugs are used widely in the treatment of type 2 diabetes to increase insulin levels in the blood.
The researchers tested NLY01 on three major cell types in the human brain: astrocytes, microglia and neurons. They found that microglia, a brain cell type that sends signals throughout the central nervous system in response to infection or injury, had the most sites for NLY01 to bind to – two times higher than the other cell types, and 10 times higher in humans with Parkinson’s disease compared to those without the disease.
In one experiment, the researchers injected mice with alpha-synuclein, the protein known to be the primary driver of Parkinson’s disease, and treated mice with NLY01. Similar but untreated mice injected with alpha-synuclein showed pronounced motor impairment over the course of six months in behavioural tests such as the pole test, which allows researchers to measure motor impairment such as that caused by Parkinson’s disease.
It was found that the mice treated with NLY01 maintained normal physical function and had no loss of dopamine neurons, indicating that the drug protected against the development of Parkinson’s disease.
The study’s lead author cautions that the experimental drug must still be tested for safety as well as effectiveness in people, but based on the safety profile of other similar drugs, he does not anticipate any major roadblocks to its use in humans.