Protein Identified That Helps Parkinson’s Disease Spread Through the Brain

A team from the University of Pennsylvania School of Medicine showed that the protein GPNMB (Glycoprotein Nonmetastatic Melanoma Protein B) acts as a “courier” of pathology. It is released by activated microglial cells (the brain’s immune cells) in response to damaged neurons and facilitates the transmission of toxic forms of the protein alpha-synuclein between cells.

In experiments using Parkinson’s disease models, blocking GPNMB with monoclonal antibodies significantly reduced the spread of pathology, protected dopamine neurons, and improved motor function in animals.

“We have identified a molecular mechanism that helps the disease ‘jump’ from cell to cell,” the authors noted. “This opens up a new promising therapeutic target that could slow or halt disease progression.”

The discovery is particularly important because GPNMB has already been studied in the context of other neurodegenerative diseases and cancer. Existing antibodies against it may accelerate the development of a new treatment.

So far, the research has been conducted in animal and cellular models. Clinical trials in humans are still a long way off, but the identified target appears promising.

The study was published in the journal Nature Medicine.

Sources: University of Pennsylvania School of Medicine. Protein identified that helps Parkinson’s disease spread in the brain. Nature Medicine, 2026.