A recent study led by Stanford Medicine researchers has found that inhibiting an overactive enzyme linked to a specific genetic mutation associated with Parkinson's disease may offer therapeutic benefits. The enzyme, known as leucine-rich repeat kinase 2 (LRRK2), becomes excessively active due to this mutation, leading to structural changes in brain cells that disrupt communication essential for dopamine signaling in the striatum, a brain region involved in movement and decision-making.
The study, published in Science Signaling, highlights the potential of a molecule called MLi-2 LRRK2 kinase inhibitor to reduce the activity of the LRRK2 enzyme, which could stabilize or even improve symptoms if treatment begins early in patients. Lead author Ebsy Jaimon and senior author Dr. Suzanne Pfeffer noted that while the mutation is a significant contributor to LRRK2 overactivity, the inhibitor could potentially benefit a broader range of Parkinson's cases and other neurodegenerative diseases.
The research demonstrated that an overactive LRRK2 enzyme leads to the loss of primary cilia—cellular structures critical for signal reception—resulting in disrupted neuroprotective signaling from dopamine neurons. Initial attempts to reverse these effects showed no changes in brain structure or neuron viability. However, after administering the inhibitor over a three-month period, researchers observed a remarkable restoration of primary cilia in striatal neurons and glia, enabling effective communication and secretion of neuroprotective factors.
The findings suggest that early intervention with LRRK2 inhibitors may enhance neuronal function and potentially improve the condition of individuals with Parkinson's disease. Future research will explore the inhibitor's efficacy in other forms of Parkinson's disease beyond the LRRK2 mutation. The study was funded by several organizations, including The Michael J. Fox Foundation for Parkinson's Research.