Pharmacological inhibition of sphingolipid synthesis reduces ferroptosis by stimulating the HIF-1 pathway

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Ferroptosis, a regulated cell death, is implicated in neurological disease pathology.
• Sphingolipid metabolism plays a role in cellular stress responses.
• Glutathione levels are critical in preventing ferroptosis.

Purpose of the Study:

• To investigate the protective effects of myriocin against ferroptosis in HT22 cells.
• To identify novel molecular targets and pathways involved in myriocin's cytoprotective mechanism.
• To explore the role of the hypoxia-inducible factor 1 (HIF-1) pathway in myriocin-mediated ferroptosis inhibition.

Main Methods:

• Cell culture (HT22 cells) and induction of ferroptosis (erastin, glutamate).
• Treatment with myriocin, a sphingolipid synthesis inhibitor.
• Transcriptome analysis to identify affected pathways.
• Validation of HIF-1 pathway involvement through molecular assays (e.g., Western blotting, ubiquitination assays).

Main Results:

• Myriocin significantly decreased erastin- or glutamate-induced ferroptosis in HT22 cells.
• Transcriptome analysis revealed the hypoxia-inducible factor 1 (HIF-1) pathway as a key target.
• HIF1α stabilization by myriocin was essential for its cytoprotective effects.
• Myriocin promoted HIF-1 pathway effectors (PDK1, BNIP3) and altered glucose metabolism.
• Myriocin reduced HIF1α ubiquitination and proteasomal degradation, stabilizing the protein.

Conclusions:

• Myriocin confers cytoprotection against ferroptosis via HIF1α stabilization, independent of glutathione levels.
• The HIF-1 pathway represents a novel therapeutic target for mitigating ferroptosis in neurological conditions.
• Myriocin's mechanism of stabilizing HIF1α is conserved across mammalian cell lines.