NGLY1 mutations cause protein aggregation in human neurons

Area of Science:

• Neuroscience
• Genetics
• Cell Biology

Background:

• Biallelic mutations in N-glycanase 1 (NGLY1) cause a rare multisystem disorder.
• NGLY1's role in human neural cells and specific disease phenotypes remains unclear.
• NGLY1 deficiency symptoms include developmental delay, intellectual disability, neuropathy, and seizures.

Purpose of the Study:

• To elucidate the cellular mechanisms underlying NGLY1 deficiency phenotypes.
• To investigate the function of NGLY1 in human cortical neurons.
• To identify potential therapeutic targets for NGLY1-related disorders.

Main Methods:

• Direct conversion of NGLY1 patient-derived induced pluripotent stem cells (iPSCs) into functional cortical neurons.
• Transcriptomic, proteomic, and functional analyses of NGLY1-deficient neurons.
• Laser capture microscopy coupled with mass spectrometry for protein aggregate characterization.

Main Results:

• NGLY1-deficient neurons exhibit impaired protein aggregate clearance, mitochondrial dysfunction, and synaptic deficits.
• These cellular phenotypes were observed in mature neurons but not astrocytes.
• Introduction of a functional NGLY1 gene rescued the observed phenotypes.
• Specific protein aggregates characteristic of NGLY1 deficiency were identified.

Conclusions:

• NGLY1 is crucial for maintaining protein homeostasis, mitochondrial function, and synaptic integrity in human neurons.
• Loss of NGLY1 function leads to specific cellular pathologies contributing to NGLY1 deficiency.
• The study provides a cellular model for NGLY1 deficiency and identifies key pathways for future therapeutic interventions.