Membrane Lipid Alterations Accelerate Cell Death [Mar. 11. 2025] DOJINDO LABORATORIES

Membrane Lipid Alterations Accelerate Cell Death [Mar. 11, 2025]

Previous Science Note

The lipid composition of cell membranes plays a critical role in regulating cell death by influencing membrane integrity, signaling pathways, and susceptibility to oxidative stress. This Science Note introduces the latest findings on lipid profile changes in cell and mitochondrial membranes as key factors in cell death processes such as apoptosis and ferroptosis.

Attenuated growth factor signaling during cell death initiation sensitizes membranes towards peroxidation
André Gollowitzer, et. al., Nature Communications, 2025.

Cytotoxic stress-induced inhibition of receptor tyrosine kinase (RTK) signaling not only induces cellular apoptosis but also increases the membrane PUFA ratio, thereby enhancing susceptibility to lipid peroxidation. Consequently, these cells become more susceptible to ferroptosis.

Highlighted technique: Increased susceptibility of the cell membrane to lipid peroxidation increases the susceptibility to ferroptosis. The actual occurrence of ferroptosis can be assessed by quantifying intracellular iron levels, ROS, lipid peroxidation and other related factors.

Creation of distinctive Bax-lipid complexes at mitochondrial membrane surfaces drives pore formation to initiate apoptosis
Luke A. Clifton, et. al., Science Advances, 2023.

Bax promotes cell death by adsorbing to the outer mitochondrial membrane, extracting lipids and forming Bax/lipid clusters on the membrane surface, facilitating apoptotic pore formation.

Highlighted technique: This study uses a biomimetic model of the mitochondrial outer membrane (MOM), as reported in several studies, to investigate the effect of Bax on membrane behavior. This model serves as a valuable tool for understanding how target factors influence MOM dynamics.

Lipid unsaturation promotes BAX and BAK pore activity during apoptosis
Shashank Dadsena, et. al., Nature Communications, 2024.

Unsaturated lipids enrich near BAX/BAK during apoptosis, increasing BAX pore activity and promoting mitochondrial outer membrane permeabilization, which is critical for apoptosis execution.

Highlighted technique: The GUV assay is an in vitro technique for generating unilamellar vesicles and analyzing membrane properties. This study evaluates membrane permeability using fluorescent dyes and compares the transfer of dyes of different molecular sizes into the vesicles to assess membrane pore size.

Related Techniques (click to open/close)

Target	Kit & Probes
Apoptosis detection in multiple samples	Annexin V Apoptosis Plate Assay Kit
Intracellular / mitochondrial ferrous ion (Fe²⁺) detection	FerroOrange, Mito-FerroGreen
Intracellular / mitochondrial lipid peroxidation detection	Liperfluo, MitoPeDPP
Mitochondrial membrane potential detection	JC-1 MitoMP Detection Kit, MT-1 MitoMP Detection Kit
Mitochondrial superoxide detection	MitoBright ROS Deep Red - Mitochondrial Superoxide Detection
Total ROS detection	Highly sensitive DCFH-DA or Photo-oxidation Resistant DCFH-DA
Cell proliferation/ cytotoxicity assay	Cell Counting Kit-8 and Cytotoxicity LDH Assay Kit-WST

Application Note (click to open/close)
> Changes in various indicators of cell death induced by drugs

	HepG2 cells treated with the apoptosis-inducing agent staurosporine or the ferroptosis-inducing agents Erastin and RSL3. After treatment, extracellular LDH, phosphatidylserine, cell viability, intracellular Fe²⁺ and lipid peroxidation were determined. The results showed that apoptosis-induced cells treated with staurosporine showed an increase in phosphatidylserine, a decrease in cell viability and an increase in extracellular LDH, indicating that cell death had occurred. On the other hand, intracellular Fe²⁺, an indicator of ferroptosis, remained unchanged. In cells treated with Erastin, a ferroptosis inducer, intracellular Fe²⁺ increased and cell viability decreased, but extracellular LDH and lipid peroxidation (lipid peroxidation: decrease in red fluorescence and increase in green fluorescence) did not increase. In cells in which ferroptosis was more strongly induced by co-treatment with RSL3 in addition to Erastin, increased intracellular Fe²⁺ and lipid peroxidation were observed. Moreover, decreased cell viability and increased dead cells were detected. Meanwhile, phosphatidylserine showed a lower rate of increase during ferroptosis induction compared to apoptosis-induced cells. These results suggest that cell death can be distinguished by evaluating a combination of cell death indicators.