OPA1 promotes ferroptosis by augmenting mitochondrial ROS and suppressing an integrated stress response.

Area of Science:

• Biochemistry
• Cell Biology
• Pathology

Background:

• Ferroptosis, an iron-dependent cell death, involves lipid peroxidation and is implicated in various diseases.
• Mitochondria critically regulate ferroptosis, yet their specific roles are not fully understood.
• Optic atrophy 1 (OPA1), a mitochondrial GTPase, influences mitochondrial structure and energy metabolism.

Purpose of the Study:

• To investigate the role of OPA1 in ferroptosis regulation.
• To elucidate the mechanisms by which OPA1 affects ferroptosis susceptibility.
• To explore the therapeutic potential of targeting OPA1 in ferroptosis-related diseases.

Main Methods:

• Utilized human and mouse cell lines lacking OPA1.
• Employed OPA1 mutants to assess the necessity of GTPase activity and mitochondrial fusion.
• Analyzed mitochondrial homeostasis, lipid reactive oxygen species (ROS) production, and the integrated stress response pathway (ATF4).

Main Results:

• Cells deficient in OPA1 exhibited significant resistance to ferroptosis.
• OPA1's role in sensitizing cells to ferroptosis depends on its GTPase activity, not mitochondrial fusion.
• OPA1 maintains mitochondrial homeostasis, promoting ROS generation and suppressing the ATF4-mediated integrated stress response, thereby sensitizing cells to ferroptosis.

Conclusions:

• OPA1 acts as a key regulator of ferroptosis through a mitochondrial pathway.
• OPA1's GTPase activity is essential for its pro-ferroptosis function.
• Targeting the OPA1-mitochondrial axis offers potential therapeutic strategies for diseases involving ferroptosis.