Related Experiment Video
Updated: Dec 2, 2025
Author Spotlight: Establishing a New Fluorescence-Based Protocol for In Vivo Mitochondrial Morphology Analysis in Parkinson's Disease
Published on: June 23, 2023
Mitochondrial and Clearance Impairment in p.D620N VPS35 Patient-Derived Neurons
Zoé Hanss1, Simone B Larsen1, Paul Antony1
1Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg.
Background:
VPS35 is part of the retromer complex and is responsible for the trafficking and recycling of proteins implicated in autophagy and lysosomal degradation, but also takes part in the degradation of mitochondrial proteins via mitochondria-derived vesicles. The p.D620N mutation of VPS35 causes an autosomal-dominant form of Parkinson's disease (PD), clinically representing typical PD.
Objective:
Most of the studies on p.D620N VPS35 were performed on human tumor cell lines, rodent models overexpressing mutant VPS35, or in patient-derived fibroblasts. Here, based on identified target proteins, we investigated the implication of mutant VPS35 in autophagy, lysosomal degradation, and mitochondrial function in induced pluripotent stem cell-derived neurons from a patient harboring the p.D620N mutation.
Methods:
We reprogrammed fibroblasts from a PD patient carrying the p.D620N mutation in the VPS35 gene and from two healthy donors in induced pluripotent stem cells. These were subsequently differentiated into neuronal precursor cells to finally generate midbrain dopaminergic neurons.
Results:
We observed a decreased autophagic flux and lysosomal mass associated with an accumulation of α-synuclein in patient-derived neurons compared to controls. Moreover, patient-derived neurons presented a mitochondrial dysfunction with decreased membrane potential, impaired mitochondrial respiration, and increased production of reactive oxygen species associated with a defect in mitochondrial quality control via mitophagy.
Conclusion:
We describe for the first time the impact of the p.D620N VPS35 mutation on autophago-lysosome pathway and mitochondrial function in stem cell-derived neurons from an affected p.D620N carrier and define neuronal phenotypes for future pharmacological interventions. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Insights
The VPS35 p.D620N mutation linked to Parkinson's disease impairs neuronal autophagy and mitochondrial function. This study reveals neuronal phenotypes in patient-derived stem cells for future therapeutic development.
Area of Science:
- Neuroscience
- Cell Biology
- Genetics
Background:
- VPS35 is crucial for protein trafficking and degradation, including mitochondrial proteins.
- The VPS35 p.D620N mutation causes an autosomal-dominant form of Parkinson's disease (PD).
- Previous studies used cell lines or animal models; this research focuses on patient-derived neurons.
Purpose of the Study:
- To investigate the impact of the VPS35 p.D620N mutation on neuronal autophagy, lysosomal degradation, and mitochondrial function.
- To utilize induced pluripotent stem cell (iPSC)-derived neurons from a PD patient carrying the mutation.
Main Methods:
- Reprogramming patient and healthy donor fibroblasts into iPSCs.
- Differentiating iPSCs into midbrain dopaminergic neurons.
- Analyzing autophagic flux, lysosomal mass, mitochondrial function, and mitophagy in patient-derived neurons.
Main Results:
- Patient-derived neurons showed reduced autophagic flux and lysosomal mass.
- Accumulation of alpha-synuclein was observed in patient neurons.
- Mitochondrial dysfunction, including decreased membrane potential and impaired respiration, was evident.
- Defects in mitophagy and increased reactive oxygen species were detected.
Conclusions:
- The VPS35 p.D620N mutation disrupts the autophago-lysosome pathway and mitochondrial function in neurons.
- This study establishes neuronal phenotypes associated with the mutation in patient-derived stem cells.
- Findings provide a basis for developing targeted pharmacological interventions for Parkinson's disease.
