# Understanding cell-type vulnerability and oxidative stress pathology in Parkinson's Disease using isogenic human dopaminergic neurons

> **NIH NIH R01** · ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI · 2021 · $398,325

## Abstract

About one million Americans live with Parkinson's Disease (PD) which is characterized by progressive loss of
subpopulations of nigral midbrain dopaminergic neurons (DNs), leading to motor impairment and other
debilitating conditions. Familial PD genes show broad expression in the brain and neurodegeneration in PD
can be widespread; however, it is unclear why nigral DNs show such exquisite vulnerability compared to
other cell types, including other DN populations. Post-mortem studies suggest that oxidative stress (OS)
contributes to familial and sporadic PD. Reactive oxygen species (ROS) are important signaling molecules
but high levels of intracellular ROS will damage DNA, lipids and proteins. High energy needs and dopamine
metabolism may explain increased ROS, OS and the unique vulnerability of nigral DNs but human-relevant
model systems are required to rigorously test this hypothesis. There is an urgent need to develop
experimental systems to better understand nigral DN vulnerability, identify novel disease-relevant signaling
mechanisms, and improve molecular subtyping and patient stratification. Our long-term goal is to understand
the vulnerability of nigral DNs through the interplay of genetics, cell type specific functions that confer
vulnerability and quantifiable phenotypes to identify new therapeutic targets. In support of this goal, we have
developed knock-in human pluripotent stem cell (hPSC) reporter lines to identify and isolate tyrosine
hydroxylase (TH)-positive DNs from large-scale organoid spin cultures. Using CRISPR mutagenesis we
created isogenic loss-of-function models of early-onset autosomal recessive PD (PARKIN-/-, DJ1-/- and
ATP13A2-/-) in TH-reporter cell lines. We detected dysregulation of mitochondrial proteins, significantly
increased OS and cell death in isogenic PD cell lines in midbrain DNs, but not in isogenic WT-control DNs. To
understand nigral DN vulnerability we propose to use our isogenic reporter PD model and single-cell RNA
sequencing approaches of human midbrain, hypothalamic and forebrain DNs to identify populations of cells
that show increased vulnerability to OS and cell death and identify differentially affected DN populations.
Expression and network analysis will identify cellular functions that confer vulnerability. We have developed
genetic tools to distinguish primary dysregulation from emerging phenotypes to further the mechanistic
understanding of genotype-phenotype interactions. Using innovative CRISPR-activation and inhibition
technologies we will test identified candidate genes for their potential to ameliorate OS phenotypes and cell
death in our PD model. Our model is conceptually and technically innovative and will illuminate common and
unique pathways that confer vulnerability or protection in nigral DNs and propose novel strategies for
prevention and treatment to improve the lives of patients and their caregivers.

## Key facts

- **NIH application ID:** 10247522
- **Project number:** 5R01NS114239-02
- **Recipient organization:** ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
- **Principal Investigator:** Joel William Blanchard
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $398,325
- **Award type:** 5
- **Project period:** 2020-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10247522

## Citation

> US National Institutes of Health, RePORTER application 10247522, Understanding cell-type vulnerability and oxidative stress pathology in Parkinson's Disease using isogenic human dopaminergic neurons (5R01NS114239-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10247522. Licensed CC0.

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