The lipid flippase SLC47A1 blocks metabolic vulnerability to ferroptosis

PUFAs dictate the balance of power in ferroptosis

Ferroptosis is an iron-dependent form of cell death triggered by dysregulation of biochemical processes that culminate in lethal lipid peroxidation. Lipid metabolism is fundamental for determining ferroptotic fate, however, the mechanisms that alter lipid components to shape ferroptosis susceptibility remains elusive. A recent article by Lin and colleagues in Nature Communications systematically analyzed phospholipid transporters (phospholipid scramblases, flippases, and floppases), and identified that the lipid flippase solute carrier family 47 member 1 (SLC47A1) functions as a regulator of lipid remodeling and promotes ferroptosis resistance. SLC47A1 is transactivated by peroxisome proliferator activated receptor alpha (PPARA). Upon ferroptosis induction, SLC47A1 upregulation inhibits DHA/DPA polyunsaturated fatty acid containing glycerophospholipids (PUFA-PLs) accumulation to block ferroptosis. Depletion of either PPARA or SLC47A1 sensitized cells to ferroptosis by favoring ACSL4-SOAT1-mediated production of polyunsaturated fatty acid containing (PUFA) cholesterol esters. Ferroptosis has been widely linked to degenerative processes and tumor suppression. These findings indicate that lipid transporters may provide yet another means by which PUFA-containing membrane lipids convey ferroptosis sensitivity.

Lipidomics Analysis in Ferroptosis

Ferroptosis is a form of regulated cell death that occurs due to abnormal lipid metabolism. Lipids, which have been identified in over 45,000 different molecular species, play essential roles in modulating basic life processes. The process of ferroptosis is highly reliant on various lipid species, with polyunsaturated fatty acids (PUFAs) playing a central role in driving this process. Recent advances in mass spectrometry-based lipidomics have led to a surge in studies on ferroptosis. To explore the mechanism of lipid homeostasis in ferroptosis, the development of lipidomics techniques is critical. Currently, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) are the most widely used analytical techniques in lipidomics. These techniques offer deeper insights into the complex lipid mechanisms that underlie ferroptosis.

Probing Lipid Peroxidation in Ferroptosis: Emphasizing the Utilization of C11-BODIPY-Based Protocols

Ferroptosis is a form of regulated cell death that relies on iron and is characterized by the accumulation of lipid peroxides, resulting in oncotic cell swelling and eventual disruption of cellular membranes. Lipid peroxidation, a hallmark of ferroptosis, refers to the oxidative deterioration of lipids that contain carbon-carbon double bonds, particularly polyunsaturated fatty acids (PUFAs). Understanding the molecular mechanisms underlying the interplay between ferroptosis and lipid peroxidation and identifying reliable techniques for assessing lipid peroxidation levels are crucial for further advancements in this field of research. Various methods have been developed to detect lipid peroxidation levels, including C11-BODIPY (BODIPY™ 581/591 C11), liperfluo, 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), Click-iT LAA (linoleamide alkyne), and liquid chromatography-mass spectrometry (LC-MS)-based epilipidomics (redox lipidomics). Currently, one of the most commonly used and effective methods is the C11-BODIPY assay, which utilizes a fluorescent probe that selectively sensitizes lipid peroxidation in cell membranes. Incorporating advanced techniques such as flow cytometry and fluorescence microscopy with C11-BODIPY dye is essential for accurate assessment of lipid peroxidation levels in ferroptosis. This chapter aims to provide comprehensive experimental protocols for detecting lipid peroxidation levels indicative of ferroptosis using C11-BODIPY staining and subsequent detection via flow cytometry and fluorescence microscopy.

Membrane Integrity Assay in Ferroptosis

Ferroptosis is a form of regulated cell death that relies on the accumulation of intracellular iron and subsequent oxidative stress. Ferroptotic cell death is characterized by uncontrolled lipid peroxidation, which leads to plasma membrane damage and rupture. The loss of plasma membrane integrity results in the release of intracellular components, including damage-associated molecular patterns, and can propagate death between cells in a synchronized manner. Understanding the mechanisms of ferroptotic membrane damage is crucial to comprehending this form of cell death. This chapter provides a summary of techniques for detecting plasma membrane integrity in ferroptosis, including transmission electron microscopy analysis, flow cytometry analysis, and assessments of oxidoreductase-mediated membrane damage.