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06:07
Author Spotlight: Establishing a New Fluorescence-Based Protocol for In Vivo Mitochondrial Morphology Analysis in Parkinson's Disease
Published on: June 23, 2023
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Pathological structural conversion of α-synuclein at the mitochondria induces neuronal toxicity
Minee L Choi1,2,3, Alexandre Chappard4, Bhanu P Singh4,5
1Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.
Nature Neuroscience
|August 30, 2022
Summary
Alpha-synuclein (α-Syn) aggregation in neurons initiates Parkinson's disease. This study reveals α-Syn oligomerization on mitochondrial membranes, leading to neuronal death and offering insights into PD pathogenesis.
Area of Science:
- Neuroscience
- Biochemistry
- Cell Biology
Background:
- Alpha-synuclein (α-Syn) aggregation is a hallmark of Parkinson's disease (PD).
- The initial intracellular steps of α-Syn self-assembly and structural changes remain poorly understood.
- Observing α-Syn dynamics within neurons is crucial for understanding PD initiation.
Purpose of the Study:
- To track intracellular conformational states of α-Syn in neurons.
- To elucidate the mechanisms of α-Syn oligomerization and its role in neuronal toxicity.
- To investigate the role of mitochondrial membranes in initiating α-Syn aggregation.
Main Methods:
- Single-molecule Förster resonance energy transfer (smFRET) biosensor to monitor α-Syn conformational changes.
- Three-dimensional FRET-correlative light and electron microscopy (FRET-CLEM) for spatial localization.
- Utilized induced pluripotent stem cell (iPSC)-derived neurons from PD patients.
Main Results:
- α-Syn converts from monomeric to two distinct oligomeric states within neurons.
- Oligomerization is concentration-dependent, sequence-specific, and initiated at membrane surfaces, particularly mitochondrial membranes.
- Mitochondrial cardiolipin triggers rapid A53T α-Syn oligomerization, impairing Complex I, increasing ROS, and causing cell death.
Conclusions:
- A novel mechanism for de novo α-Syn oligomerization at mitochondrial membranes is identified.
- Mitochondrial dysfunction and ROS generation accelerate α-Syn aggregation, leading to neuronal death.
- This pathway is relevant to Parkinson's disease, as evidenced in patient-derived iPSC neurons.
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