tRNA modification enzyme-dependent redox homeostasis regulates synapse formation and memory

Area of Science:

• Molecular Biology
• Neuroscience
• Genetics

Background:

• Post-transcriptional RNA modification is crucial for gene expression.
• ALKBH8 is a tRNA-modifying enzyme essential for selenoprotein synthesis and redox homeostasis.
• ALKBH8 variants are linked to intellectual disability, but its nervous system role is unclear.

Purpose of the Study:

• Investigate the function of ALKBH8 in the nervous system.
• Determine the impact of ALKBH8 on oxidative stress, synaptic development, and cognitive function.
• Explore the therapeutic potential of antioxidants for ALKBH8-associated disorders.

Main Methods:

• In vivo studies using Drosophila melanogaster models.
• Analysis of tRNA wobble uridine methylation and protein synthesis.
• Assessment of synaptic morphology and associative learning and memory.

Main Results:

• ALKBH8 deficiency in Drosophila leads to reduced protein synthesis, decreased selenoprotein levels, and increased oxidative stress in the brain.
• Loss of ALKBH8 or selenoprotein synthesis causes ectopic synapse formation.
• Antioxidant treatment ameliorates synaptic overgrowth and rescues memory impairments in ALKBH8 null animals.

Conclusions:

• ALKBH8-mediated tRNA modification is vital for maintaining redox homeostasis in the developing nervous system.
• Oxidative stress underlies synaptic dysregulation and memory deficits in ALKBH8 deficiency.
• Antioxidants represent a promising therapeutic strategy for ALKBH8-associated intellectual disabilities.