Engrailed 1 deficiency induces changes in ciliogenesis during human neuronal differentiation

Area of Science:

• Neuroscience
• Stem Cell Biology
• Molecular Biology

Background:

• Parkinson's Disease (PD) involves dopaminergic neuron (DAn) degeneration.
• The transcription factor EN1 is crucial for DAn development and maintenance.
• Human cellular models are needed to study EN1's role in PD pathogenesis.

Purpose of the Study:

• To investigate the role of EN1 in human dopaminergic neurons using induced pluripotent stem cells (hiPSCs).
• To analyze the impact of EN1 deficiency on neuronal differentiation, mitochondrial function, and primary cilia.
• To explore potential neuroprotective strategies for Parkinson's Disease.

Main Methods:

• Generation of EN1 knock-out (ko) hiPSC lines.
• Neuronal differentiation and analysis of dopaminergic neuron markers (TH+).
• Assessment of neurite length, mitochondrial respiration, and mitochondrial complex I abundance.
• Transcriptome analysis of human neuronal precursor cells (hNPCs).
• Analysis of primary cilia morphology and Wnt signaling pathway activity.
• Wnt stimulation experiments in EN1-deficient and wild-type cells.

Main Results:

• EN1 deficiency did not prevent neuronal differentiation or TH+ neuron generation but resulted in shorter neurites.
• EN1-ko neurons showed reduced mitochondrial respiration and mitochondrial complex I abundance.
• EN1 deficiency led to altered cilia-associated pathways, elongated primary cilia, and affected Wnt signaling.
• Wnt stimulation exacerbated mitochondrial dysfunction and altered cilia length in EN1-ko hNPCs.

Conclusions:

• EN1 is essential for maintaining dopaminergic neuron functionality, impacting mitochondrial health and primary cilia.
• Primary cilia and mitochondria are critical for human DAn maintenance.
• This study provides insights for developing novel neuroprotective therapies for Parkinson's Disease.