Mitochondrial stress causes neuronal dysfunction via an ATF4-dependent increase in L-2-hydroxyglutarate

Area of Science:

• Neuroscience
• Cellular Biology
• Metabolic Disorders

Background:

• Mitochondrial stress is implicated in neurological diseases.
• Mitonuclear signaling pathways are activated by mitochondrial stress.
• The precise mechanisms linking these pathways to neuronal dysfunction remain unclear.

Purpose of the Study:

• To investigate the role of mitochondrial stress in neuronal dysfunction.
• To identify signaling mechanisms activated by mitochondrial stress in neurons.
• To explore the contribution of these mechanisms to neurological disease.

Main Methods:

• Utilized *Drosophila* as a model organism.
• Investigated the activation of transcription factor ATF4.
• Measured levels of L-2-hydroxyglutarate (L-2-HG) in the brain.
• Assessed the impact of modulating L-2-HG levels on neurological function.

Main Results:

• Mitochondrial stress in neurons activates ATF4 via the endoplasmic reticulum unfolded protein response (UPR).
• ATF4 activation reprograms nuclear gene expression, contributing to neuronal dysfunction.
• Mitochondrial stress leads to an ATF4-dependent increase in brain L-2-HG levels.
• Overexpression of L-2-HG dehydrogenase reduces L-2-HG and improves neurological function.

Conclusions:

• ATF4 acts as a key mediator of mitochondrial stress responses in neurons.
• The metabolite L-2-HG is a critical downstream effector of this signaling pathway.
• Modulating L-2-HG levels offers a potential therapeutic strategy for neurological disorders linked to mitochondrial stress.