Mitochondrial oxidative stress mediated Fe-induced ferroptosis via the NRF2-ARE pathway

Area of Science:

• Biochemistry
• Cell Biology
• Pathology

Background:

• Ferroptosis is an iron-dependent form of regulated cell death characterized by lipid peroxidation.
• The precise molecular mechanisms driving ferroptosis, particularly the roles of mitochondria and oxidative stress, are not fully understood.

Purpose of the Study:

• To investigate the involvement of mitochondria and the NRF2 pathway in iron-induced ferroptosis.
• To elucidate the molecular mechanisms linking iron overload, oxidative stress, and ferroptosis.

Main Methods:

• High-iron diet administration in vivo and cell culture experiments (HEK293T cells).
• Assessment of hepatic iron content, glutathione levels, lipid peroxidation, and oxidative stress markers.
• Analysis of gene and protein expression of ferroptosis markers (GPX4, SLC7A11, ACSL4).
• Measurement of mitochondrial reactive oxygen species (ROS) and mitochondrial membrane potential (MMP).
• Iron chelation therapy (deferoxamine mesylate) and NRF2 pathway analysis (binding to antioxidant response elements).

Main Results:

• Dietary iron overload increased hepatic iron, depleted glutathione, and enhanced lipid peroxidation and oxidative stress.
• Iron overload decreased GPX4 and SLC7A11 expression while increasing ACSL4, consistent with ferroptosis induction.
• Mitochondrial ROS generation increased, and mitochondrial membrane potential decreased, indicating mitochondrial dysfunction.
• Deferoxamine mesylate treatment mitigated ROS and lipid peroxidation, confirming iron's causative role.
• Fe-induced ferroptosis involved NRF2 pathway inhibition, leading to transcriptional silencing of GPX4 and SLC7A11.

Conclusions:

• Mitochondrial oxidative stress is a key mediator in iron-induced ferroptosis.
• The NRF2-ARE pathway directly links mitochondrial oxidative stress to ferroptosis by regulating GPX4 and SLC7A11 expression.
• This study establishes a clear molecular mechanism for ferroptosis driven by iron overload.