Cofilin1 oxidation links oxidative distress to mitochondrial demise and neuronal cell death

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Neuronal cell death involves pathways like apoptosis, regulated necrosis, and ferroptosis, often sharing mechanisms of reactive oxygen species (ROS) production and mitochondrial damage.
• The actin-regulating protein cofilin1's role in these neuronal death pathways, particularly concerning mitochondria, requires further elucidation.

Purpose of the Study:

• To investigate the function of cofilin1 in regulating mitochondrial pathways during oxidative neuronal death.
• To determine cofilin1's involvement in ferroptosis and glutamate excitotoxicity.
• To explore the potential of cofilin1 inhibition as a therapeutic strategy for neurodegenerative diseases.

Main Methods:

• Utilized neuronal HT22 cells and primary cortical neurons.
• Assessed mitochondrial resilience by quantifying mitochondrial ROS, membrane potential, and ATP levels.
• Investigated cellular energy metabolism (glycolysis vs. mitochondrial respiration).
• Examined the role of cofilin1 oxidation at specific cysteine residues (139 and 147).

Main Results:

• Cofilin1 deletion enhanced mitochondrial resilience and ATP production in HT22 cells.
• Cofilin1-deficient cells relied on glycolysis, while control cells showed metabolic impairment during ferroptosis.
• Cofilin1 was identified as a key mediator of glutamate excitotoxicity and mitochondrial damage in primary neurons.
• Oxidized cofilin1 directly impairs mitochondrial function, with cysteine residues 139 and 147 being critical.

Conclusions:

• Cofilin1 functions as a redox sensor in oxidative cell death pathways like ferroptosis and contributes to glutamate excitotoxicity.
• Cofilin1 negatively impacts mitochondrial integrity and function, particularly when oxidized.
• Inhibiting cofilin1's oxidation and pathological activation may preserve mitochondrial function and offer a therapeutic avenue for neurodegenerative conditions.