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Updated: Sep 27, 2025
Author Spotlight: Advancing 3D Cell Modeling – A High-Throughput Approach for Neural Cocultures
Published on: September 29, 2023
Human IPSC 3D brain model as a tool to study chemical-induced dopaminergic neuronal toxicity
David Pamies1, Daphne Wiersma2, Moriah E Katt3
1Center for Alternative to Animal Testing, Johns Hopkins University, 615 North Wolfe St., Baltimore, MD 21205, United States of America; Department of Biomedical Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland.
Abstract:
Oxidative stress is caused by an imbalance between the generation and detoxification of reactive oxygen and nitrogen species (ROS/RNS). This imbalance plays an important role in brain aging and age-related neurodegenerative diseases. In the context of Parkinson's disease (PD), the sensitivity of dopaminergic neurons in the substantia nigra pars compacta to oxidative stress is considered a key factor of PD pathogenesis. Here we study the effect of different oxidative stress-inducing compounds (6-OHDA, MPTP or MPP+) on the population of dopaminergic neurons in an iPSC-derived human brain 3D model (aka BrainSpheres). Treatment with 6-OHDA, MPTP or MPP+ at 4 weeks of differentiation disrupted the dopaminergic neuronal phenotype in BrainSpheres at (50, 5000, 1000 μM respectively). 6-OHDA increased ROS production and decreased mitochondrial function most efficiently. It further induced the greatest changes in gene expression and metabolites related to oxidative stress and mitochondrial dysfunction. Co-culturing BrainSpheres with an endothelial barrier using a transwell system allowed the assessment of differential penetration capacities of the tested compounds and the damage they caused in the dopaminergic neurons within the BrainSpheres In conclusion, treatment with compounds known to induce PD-like phenotypes in vivo caused molecular deficits and loss of dopaminergic neurons in the BrainSphere model. This approach therefore recapitulates common animal models of neurodegenerative processes in PD at similarly high doses. The relevance as tool for drug discovery is discussed.
Insights
Oxidative stress contributes to brain aging and Parkinson's disease (PD). This study used a 3D human brain model to show that compounds inducing PD-like symptoms damage dopaminergic neurons, highlighting the model's utility for drug discovery.
Area of Science:
- Neuroscience
- Cell Biology
- Toxicology
Background:
- Oxidative stress, an imbalance in reactive oxygen and nitrogen species (ROS/RNS), is implicated in brain aging and neurodegenerative diseases like Parkinson's disease (PD).
- Dopaminergic neurons in the substantia nigra pars compacta are particularly vulnerable to oxidative stress, a key factor in PD pathogenesis.
Purpose of the Study:
- To investigate the impact of specific oxidative stress-inducing compounds (6-OHDA, MPTP, MPP+) on dopaminergic neurons within a human 3D brain model (BrainSpheres).
- To evaluate the efficacy of the BrainSphere model in recapitulating PD-related neurodegenerative processes and its potential for drug discovery.
Main Methods:
- Utilized induced pluripotent stem cell (iPSC)-derived human BrainSpheres as a 3D model system.
- Administered oxidative stress-inducing agents (6-OHDA, MPTP, MPP+) to BrainSpheres at 4 weeks of differentiation.
- Assessed dopaminergic neuronal phenotype, reactive oxygen species (ROS) production, mitochondrial function, and gene/metabolite expression.
- Employed a transwell system to model an endothelial barrier for assessing compound penetration and differential damage.
Main Results:
- Treatment with 6-OHDA, MPTP, and MPP+ disrupted the dopaminergic neuronal phenotype in BrainSpheres at specific concentrations.
- 6-OHDA demonstrated the highest efficiency in increasing ROS production and decreasing mitochondrial function.
- Significant alterations in gene expression and metabolites related to oxidative stress and mitochondrial dysfunction were observed, particularly with 6-OHDA.
- The transwell system demonstrated differential compound penetration and subsequent damage to dopaminergic neurons.
Conclusions:
- The BrainSphere model effectively recapitulates molecular deficits and dopaminergic neuron loss induced by PD-related compounds, mirroring findings from in vivo animal models.
- This 3D human brain model, even at high compound doses, serves as a valuable tool for studying neurodegeneration and for drug discovery in Parkinson's disease.
- The study validates the use of iPSC-derived BrainSpheres for modeling neurotoxic insults relevant to Parkinson's disease pathogenesis.
