Membrane Channels Research Articles

Probing membrane deformation energy by KcsA potassium channel gating under varied membrane thickness and tension.

This study investigated how membrane thickness and tension modify the gating of KcsA potassium channels when simultaneously varied. The KcsA channel undergoes global conformational changes upon gating: expansion of the cross-sectional area and longitudinal shortening upon opening. Thus, membranes impose differential effects on the open and closed conformations, such as hydrophobic mismatches. Here, the single-channel open probability was recorded in the contact bubble bilayer, by which variable thickness membranes under a defined tension were applied. A fully open channel in thin membranes turned to sporadic openings in thick membranes, where the channel responded moderately to tension increase. Quantitative gating analysis prompted the hypothesis that tension augmented the membrane deformation energy when hydrophobic mismatch was enhanced in thick membranes.

Immune protection of grass carp by oral vaccination with recombinant Bacillus methylotrophicus expressing the heterologous tolC gene

In the field of aquaculture, the enhancement of animal health and disease prevention is progressively being tackled using alternatives to antibiotics, including vaccines and probiotics. This study was designed to evaluate the potential of a recombinant Bacillus methylotrophicus, engineered to express the outer membrane channel protein TolC of Aeromonas hydrophila AH3 and the green fluorescent protein GFP, as an oral vaccine. Initially, the genes encoding tolC and GFP were cloned into a prokaryotic expression system, and anti-TolC mouse antiserum was generated. Subsequently, the tolC gene was subcloned into a modified pMDGFP plasmid, which was transformed into B. methylotrophicus WM-1 for protein expression. The recombinant B. methylotrophicus BmT was then administered to grass carp via co-feeding, and its efficacy as an oral vaccine was assessed. Our findings demonstrated successful expression of the 55 kDa TolC and 28 kDa GFP proteins, and the preparation of polyclonal antibodies with high specificity. The BmT exhibited stable expression of the GFP-TolC fusion protein and excellent genetic stability. Following oral immunization, significant elevations were observed in serum-specific IgM levels and the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), and lysozyme (LZM) in grass carp. Concurrently, significant upregulation of immune-related genes, including IFN-I, IL-10, IL-1β, TNF-α, and IgT, was noted in the intestines, head kidney, and spleen of the grass carp. Colonization tests further revealed that the BmT persisted in the gut of immunized fish even after a fasting period of 7 days. Notably, oral administration of BmT enhanced the survival rate of grass carp following A. hydrophila infection. These results suggest that the oral BmT vaccine developed in this study holds promise for future applications in aquaculture.

Synergy effects of pH and thermal localization on membrane-based salinity gradient energy harvesting

Salinity gradient power generation receives increasing attention due to its availability in nature. However, membrane surface charge is not fixed value in isolation but strongly dependent of various conditions. Here, a coupled ion transport model is proposed to study the synergy effects of pH and thermal localization on membrane-based salinity gradient energy conversion. The research illustrates that the surface charge is regulated by solution environment, membrane properties and thermal conditions. Specially, the surface charge sign can be even reversed at certain case that induces distinct ion transports behaviors. Consequently, Al2O3 membrane achieves the better energy conversion performance at low pH with negative temperature difference. While SiO2 membrane obtains the best output performance at high pH with negative temperature difference. Such is ascribed to pH-regulated surface charge and thermal up-diffusion enhancement. The maximum output power of 10 pW with efficiency of 16 % is achieved for individual membrane channel. As a proof of concept, it shows significant deviations between the single and coupling model on power generation. The findings of this study can help for better understanding the coupling mechanisms of solution, membrane and thermal conditions during the energy conversions, thereby providing a reasonable design route for membrane-based energy devices.

Zn-ion ultrafluidity via bioinspired ion channel for ultralong lifespan Zn-ion battery.

Rechargeable aqueous Zn-ion batteries have been deemed a promising energy storage device. However, the dendrite growth and side reactions have hindered their practical application. Herein, inspired by the ultrafluidic and K+ ion-sieving flux through enzyme-gated potassium channels (KcsA) in biological plasma membranes, a metal-organic-framework (MOF-5) grafted with -ClO4 groups (MOF-ClO4) as functional enzymes is fabricated to mimic the ultrafluidic lipid-bilayer structure for gating Zn2+ 'on' and anions 'off' states. The MOF-ClO4 achieved perfect Zn2+/SO4 2- selectivity (∼10), enhanced Zn2+ transfer number ([Formula: see text]) and the ultrafluidic Zn2+ flux (1.9×10-3 vs. 1.67mmol m-2 s-1 for KcsA). The symmetric cells based on MOF-ClO4 achieve a lifespan of over 5400h at 10mAcm-2/20mAhcm-2. Specifically, the performance of the PMCl-Zn//V2O5 pouch cell keeps 81% capacity after 2000 cycles at 1Ag-1. The regulated ion transport, by learning from a biological plasma membrane, opens a new avenue towards ultralong lifespan aqueous batteries.

Gramicidin A as a mechanical sensor for mixed nonideal lipid membranes.

Gramicidin A (gA) is a short hydrophobic β-helical peptide that forms cation-selective channels in lipid membranes in the course of transbilayer dimerization. The length of the gA helix is smaller than the thickness of a typical lipid monolayer. Consequently, elastic deformations of the membrane arise in the configurations of gA monomers, conducting dimer, and the intermediate state of coaxial pair, where gA monomers from opposing membrane monolayers are located one on top of the other. The gA channel is characterized by the average lifetime of the conducting state. The elastic properties of the membrane influence the average lifetime, thus making gA a convenient sensor of membrane elasticity. However, the utilization of gA to investigate the elastic properties of mixed membranes comprising two or more components frequently relies on the assumption of ideality, namely that the elastic parameters of mixed-lipid bilayers depend linearly on the concentrations of the components. Here, we developed a general approach that does not rely on the aforementioned assumption. Instead, we explicitly accounted for the possibility of inhomogeneous lateral distribution of all lipid components, as well as for membrane-mediated lateral interactions of gA monomers, dimer, coaxial pair, and minor lipid components. This approach enabled us to derive unknown elastic parameters of lipid monolayer from experimentally determined lifetimes of gA channel in mixed-lipid bilayers. A general algorithm was formulated that allows the unknown elastic parameters of a lipid monolayer to be obtained using gA as a mechanical sensor.

SARS-CoV-2 Viroporin E Induces Ca2+ Release and Neuron Cell Death in Primary Cultures of Rat Hippocampal Cells Aged In Vitro.

The COVID-19 pandemic was caused by infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which may lead to serious respiratory, vascular and neurological dysfunctions. The SARS-CoV-2 envelope protein (E protein) is a structural viroporin able to form ion channels in cell membranes, which is critical for viral replication. However, its effects in primary neurons have not been addressed. Here we used fluorescence microscopy and calcium imaging to study SARS-CoV-2 viroporin E localization and the effects on neuron damage and intracellular Ca2+ homeostasis in a model of rat hippocampal neurons aged in vitro. We found that the E protein quickly enters hippocampal neurons and colocalizes with the endoplasmic reticulum (ER) in both short-term (6-8 days in vitro, DIV) and long-term (20-22 DIV) cultures resembling young and aged neurons, respectively. Strikingly, E protein treatment induces apoptosis in aged neurons but not in young neurons. The E protein induces variable increases in cytosolic Ca2+ concentration in hippocampal neurons. Ca2+ responses to the E protein are due to Ca2+ release from intracellular stores at the ER. Moreover, E protein-induced Ca2+ release is very small in young neurons and increases dramatically in aged neurons, consistent with the enhanced Ca2+ store content in aged neurons. We conclude that the SARS-CoV-2 E protein quickly translocates to ER endomembranes of rat hippocampal neurons where it releases Ca2+, probably acting like a viroporin, thus producing Ca2+ store depletion and neuron apoptosis in aged neurons and likely contributing to neurological damage in COVID-19 patients.

Pore-Forming VDAC Proteins of the Outer Mitochondrial Membrane: Regulation and Pathophysiological Role.

Voltage-dependent anion channels (VDAC1-3) of the outer mitochondrial membrane are a family of pore-forming β-barrel proteins that carry out controlled "filtration" of small molecules and ions between the cytoplasm and mitochondria. Due to the conformational transitions between the closed and open states and interaction with cytoplasmic and mitochondrial proteins, VDACs not only regulate the mitochondrial membrane permeability for major metabolites and ions, but also participate in the control of essential intracellular processes and pathological conditions. This review discusses novel data on the molecular structure, regulatory mechanisms, and pathophysiological role of VDAC proteins, as well as future directions in this area of research.

Significance of new geometry of flow channels in proton exchange membrane fuel cell with comparing experimental and numerical methods

The flow field geometry mainly affects the electrochemical reaction, the mass transfer, and gas diffusion layers. All these parameters affect the performance of a PEM fuel cell. In this study, a three-dimensional model is used for all parts of the fuel cell such as the flow channels, gas-diffusion electrodes, catalyst layers, and the membrane. These equations are numerically solved using a finite volume-based computational fluid dynamics technique to investigate the effect of using new geometries such as tubular, rectangular, elliptical, and triangular compared to planner-type fuel cells. Also, a test bench was designed and constructed for checking the cell and a series of experiments were done. The results show that there is good agreement between the numerical and experimental results. In summary, the tubular geometry has the best performance compared to others which can increase the execution of the fuel cell maximum by 43 %.

Mechano-activated connexin hemichannels and glutathione transport protect lens fiber cells against oxidative insults

Long-lived lens fiber cells require a robust cellular protective function against oxidative insults to maintain their hemostasis and viability; however, the underlying mechanism is largely obscure. In this study, we unveiled a new mechanism that protects lens fiber cells against oxidative stress-induced cell death. We found that mechano-activated connexin (Cx) hemichannels (HCs) mediate the transport of glutathione (GSH) into chick embryonic fibroblasts (CEF) and primary lens fiber cells, resulting in a decrease in the accumulation of intracellular reactive oxygen species induced by both H2O2 and ultraviolet B, providing protection to lens fiber cells against cell apoptosis and necrosis. Furthermore, HCs formed by both homomeric Cx50 or Cx46 and heteromeric Cx50/Cx46 were mechanosensitive and could transport GSH into CEF cells. Notably, mechano-activated Cx50 HCs exhibited a greater capacity to transport GSH than Cx46 HCs. Consistently, the deficiency of Cx50 in single lens fiber cells led to a higher level of oxidative stress. Additionally, outer cortical short lens fiber cells expressing full length Cxs demonstrated greater resistance to oxidative injury compared to central core long lens fibers. Taken together, our results suggest that the activation of Cx HCs by interstitial fluid flow in cultured epithelial cells and isolated fiber cells shows that HCs can serve as a pathway for moving GSH across the cell membrane to offer protection against oxidative stress.

Analysis of the gas transport resistance of CO2 and CH4 through ultra-thin DD3R zeolite membrane

Ultra-thin DD3R zeolite membranes exhibit excellent separation properties for CO2 capture from natural gas, as well as the lower transmembrane resistance. However, the interfacial transport of permeation gas in such systems may dominate the whole separation process. In this work, we employed external force non-equilibrium molecular dynamic (EF-NEMD) simulation to predict the single-component permeabilities of CO2 and CH4 through a defect-free DD3R zeolite membrane at different pressured drops. By explicitly including the gas transport from bulk phase to zeolitic channels, the predicted results of EF-NEMD simulation showed good agreements with the reported experimental data. The contribution of interfacial resistance over the total transport resistance (Rinter/Rtotal) was further evaluated for the membranes with different thicknesses under temperatures between 273 K and 373 K. The results revealed a decrease in Rinter/Rtotal with increasing membrane thickness, leading to a reduction in CO2/CH4 selectivity, and the critical thickness (Rinter/Rtotal < 0.01) was determined to be approximately 300 nm at pressure of 1.0 MPa and temperature of 298 K. Similarly, the Rinter/Rtotal decreased with increasing temperature due to the augmentation in molecule kinetic energy. Furthermore, it was confirmed that the gas adsorption effect could expand the effective size of eight membered ring (8-MR) channels in DD3R zeolite membrane, thereby decreasing the CO2/CH4 selectivity, despite higher permeation fluxes. The above discoveries essentially benefit the design of the ultra-thin DD3R zeolite membrane through an understanding of CO2 and CH4 transport behaviors.

α-Latrotoxin Tetramers Spontaneously Form Two-Dimensional Crystals in Solution and Coordinated Multi-Pore Assemblies in Biological Membranes.

α-Latrotoxin (α-LTX) was found to form two-dimensional (2D) monolayer arrays in solution at relatively low concentrations (0.1 mg/mL), with the toxin tetramer constituting a unit cell. The crystals were imaged using cryogenic electron microscopy (cryoEM), and image analysis yielded a ~12 Å projection map. At this resolution, no major conformational changes between the crystalline and solution states of α-LTX tetramers were observed. Electrophysiological studies showed that, under the conditions of crystallization, α-LTX simultaneously formed multiple channels in biological membranes that displayed coordinated gating. Two types of channels with conductance levels of 120 and 208 pS were identified. Furthermore, we observed two distinct tetramer conformations of tetramers both when observed as monodisperse single particles and within the 2D crystals, with pore diameters of 11 and 13.5 Å, suggestive of a flickering pore in the middle of the tetramer, which may correspond to the two states of toxin channels with different conductance levels. We discuss the structural changes that occur in α-LTX tetramers in solution and propose a mechanism of α-LTX insertion into the membrane. The propensity of α-LTX tetramers to form 2D crystals may explain many features of α-LTX toxicology and suggest that other pore-forming toxins may also form arrays of channels to exert maximal toxic effect.

SGLT2i Alleviates Atherosclerosis by Inhibiting NHE1 Activation to Protect against Macrophage Senescence Induced by Angiotensin II.

Sodium-dependent glucose transporter (SGLT2) inhibitors (SGLT2i) have been found to have anti-atherosclerotic effects in clinical treatment. The aim of this study was to explore whether angiotensin II (Ang II) induces changes in the expression of Na+/H+ exchanger of cytoplasmic membrane channel proteins (NHE1) and SGLT2 in macrophages and whether dapagliflozin (DAPA), an SGLT2i, protects against Ang II induced macrophage senescence by inhibiting NHE1 activation to alleviate Atherosclerosis (AS). After intervention with DAPA plus gavage or feeding them a high-fat diet, the mice's aortas were dissected, and oil red O staining was performed. Cell proliferation and toxicity detection, western blot, immunofluorescence, and β-galactosidase staining methods were adopted to detect cell activity, expressions of senescence-related genes, and number of senescent cells after different concentrations of Ang II or DAPA or plasmid NHE1 were treated with RAW264.7 cells. (1) The formation of AS plaques in ApoE -/- mice showed a downward trend under DAPA. (2) After the intervention of Ang II, the cell activity of RAW264.7 decreased, and the expression of senescent cells and related genes increased. (3) Under the Ang II condition, the expression of SGLT2 and NHE1 increased, and SGLT2, NHE1, and senescence-related genes decreased with the addition of DAPA. (4) The expression of NHE1, senescent cells and related genes decreased in RAW264.7 cells after DAPA treatment with plasmid NHE1 intervention. SGLT2i alleviates atherosclerosis by inhibiting NHE1 activation to protect against macrophage senescence induced by Ang II.

Recent advances in cryotolerance biomarkers for semen preservation in frozen form-A systematic review.

Spermatozoa cryopreservation has been practiced for decades and is a very useful technique for long-term preservation of sperm fertility. The capability for semen cryopreservation varies across species, seasons, latitudes, and even for different ejaculates from the same animal. This article summarizes research results on sperm cryotolerance biomarkers in several species, focusing on three areas: spermatozoa cryotolerance biomarkers, seminal plasma proteins cryotolerance biomarkers, and other cryotolerance biomarkers. We discovered that sperm cryoresistance biomarkers are primarily related to sperm plasma membrane stability, the presence of antioxidant substances in sperm or seminal plasma, sperm cell energy metabolism, water and small molecule transport channels in the sperm plasma membrane, and antistress substances in sperm or seminal plasma. The research conducted using diverse livestock models can be employed to enhance the basic and applied reproduction of other mammals through the study of sperm cryotolerance biomarkers, as well as the substantial similarities between livestock and other organisms, including endangered species.

Fabrication of high-performance recrystallized silicon carbide ceramic membrane based on particle packing optimization

Overcoming the challenges associated with achieving high uniformity and connectivity of pore channels in ceramic membranes, we designed silicon carbide ceramic membrane derived from the recrystallization process based on the Dinger-Funk equation of the closest-packing model with various grain grading. Furthermore, the effects of particle size distribution on the resulting microstructure and pore architecture of the ceramic membrane was also explored. The findings corroborated the critical importance of raw material particle size distribution in controlling pore size distribution and morphology. After sintering at 1900°C, the silicon carbide ceramic membrane, benefiting from ideal particle packing, exhibited a remarkably uniform pore structure. Notably, the most probable pore size constituted over 70 %, while achieving an open porosity of 51.3 % even without the addition of pore-forming agents. The silicon carbide ceramic membrane also demonstrated exceptional hydrophilicity (water contact angle:∼0°), impressive water permeation (1210 L m−2 h−1·bar−1), coupled with efficient turbidity removal (∼100 %) in carbon black wastewater treatment applications. Additionally, membrane regeneration proved effective using a dilute NaOH solution backwash, achieving a flux recovery efficiency of 98 %. This strategy had directive significance for designing high-performing silicon carbide ceramic membranes.

Two co-existing and opposing mechanisms of proton transfer in one-dimensional open-end water chains.

The proton transport in one-dimensional (1D) confined water chains has been extensively studied as a model for ion channels in cell membrane and fuel cell. However, the mechanistic understanding of the proton transfer (PT) process in 1D water chains remains incomplete. In this study, we demonstrate that the two limiting structures of the hydrated excess proton, H5O2+ (Zundel) and H3O+ (linear H7O3+), undergo a change in dominance as the water chain grows, causing two co-existing and opposing PT mechanisms. Specifically, H5O2+ is stable in the middle of the chain, whereas H3O+ serves as a transition state (TS). Except for this region, H3O+ is stabilized while H5O2+ serves as a TS. The interaction analysis shows that the electrostatic interaction plays a crucial role in the difference in PT mechanisms. Our work fills a knowledge gap between the various PT mechanisms reported in bulk water and long 1D water chains, contributing to a deeper understanding of biological ion channels at the atomic level.

Modelling spatio-temporal interactions between second messengers Ca and cAMP in a pancreatic -cell.

Calcium serves as a widespread second messenger in almost every human and animal cell. The regulation of various cellular processes, such as transcriptional control and the kinetics of membrane channels, is significantly influenced by intracellular calcium ions (Ca ), and linkages between Ca and other second messengers should activate signaling networks. The passage of ions across the cell membrane regulates Ca levels in pancreatic -cells and requires the coordinated interaction of various ion transport mechanisms and organelles. The signaling of Ca in -cells and its interactions with the intracellular dynamics of cyclic adenosine monophosphate (cAMP) is poorly understood. Therefore, the current investigation proposes a mathematical model to illustrate the spatiotemporal dynamical interaction between Ca and cAMP. In order to construct a one-dimensional mathematical model, the fundamental initial and boundary conditions derived from the physiological characteristics of the -cell are incorporated. The numerical results were obtained by MATLAB simulations using the finite element method and the Crank-Nicolson method. The current study aims to offer an update on regulation between Ca and cAMP signaling circuits, with a focus on interactions that occur in localized areas of the -cell. The model gives the individual effect of each parameter on the regulation of Ca and cAMP profiles in a -cell. Evidently, impairments in the regulation of messenger pathways contribute to the pathological conditions, as demonstrated by the results obtained.

The nanostructure of ion channels of thin PFSA membrane in the catalyst layer: A molecular dynamics simulation study combined with unsupervised machine learning

The nanostructure of ion channels of thin perfluorosulfonic acid membrane in the catalyst layer plays an important role in determining the efficiency of proton exchange membrane fuel cells. However, it is still unclear at microscopic scale at present time. In this work, by combining molecular dynamics simulation with unsupervised machine learning, the nanostructure of ion channels in the catalyst layer was visualized and quantified, including the size, shape, distribution and connectivity. Then the effects of water content and side chain length on the nanostructure of ion channels in the catalyst layer were revealed. It is shown that the water content has a more important effect than side chain length. As the water content increases and the side chain becomes shorter, the ionic clusters become larger and the bridging region between neighboring ionic clusters becomes wider. Moreover, the shape anisotropy of the ionic clusters becomes slightly smaller with increasing water content. The heterogeneity of the diffusion of water molecules is revealed, which may originate from the spatial limiting effect of the size of ionic clusters, as well as the strong interactions with sulfonate and platinum. It is also found that the jumping of water molecules between neighboring ionic clusters is a rate-limiting step of transport. This study provides a fundamental and comprehensive understanding on the nanostructure of ion channels and related transport properties in the thin PFSA membrane of catalyst layer, which is vital for the design of high-performance proton exchange membranes.

Ferroptosis inducers – erastin and analogues (review)

Introduction. Improving the efficacy of chemotherapy is a non-trivial task of modern oncology. Its successful solution requires knowledge in many fields, including physiology, pathology, clinical oncology, pharmacology and others. The search for small molecules that selectively kill tumor cells led to the accidental discovery of erastin.Text. Erastin is a unique molecule that has a quinazoline fragment in its structure. Not so long ago it became known that the antitumour effect of this compound is due to the induction of ferroptosis – an iron-dependent form of cell death caused by lipid peroxidation. Erastin is able to induce ferroptosis through various biochemical pathways, including blocking of cystine-glutamate transport channel of cell membrane and potential-dependent anion channel of mitochondria, as well as activation of p53 protein.Conclusion. Pharmacological induction of ferroptosis by erastin and its analogues represents a promising direction in cancer chemotherapy. In addition, erastin and its analogues are able to increase sensitivity to chemotherapy and radiation therapy, which allows us to talk about the possibility of their use in the combined treatment of malignant neoplasms.

Anti-bacterial PVA@Ag/PVDF NF membrane made by filtration-coating plus in-situ reduction of NPs for dye removal

In this study, a filtration-coating method was developed to create a PVA layer on a PVDF membrane, and then silver nanoparticles (Ag NPs) were introduced by in-situ reduction to form an antibacterial PVA@Ag/PVDF NF membrane. The relationship between the rejection of dye by the membrane, the morphology of the coated PVA layer and its coating process parameters, such as polymer concentration, crosslinking ratio, vacuum pressure, and time, was investigated. The filtration-coating method facilitated the infiltration of PVA molecules into the porous channel of PVDF membrane, thus improved the stability of coated PVA. Meanwhile, it was observed that high vacuum pressure (1 bar), high polymer concentration (2%), and short filtration time (5 min) have a similar effect to low polymer concentration (1%) and long filtration time (10 min), which results in the formation of a dense layer structure (2–5 μm) on the membrane surface and leads to a high rejection rate but low flux. While filtration at low vacuum pressure (0.1 bar) leads to a thin PVA layer (<0.2μm), and PVA turns to appear on the entrance and surface of pore channel of membrane. The coated membrane showed a stable performance during 72 hrs filtration. Furthermore, Ag NPs were incorporated into PVA layer by the in-situ reduction method, the obtained membrane showed an enhanced dye rejection (92% for methyl blue), and a low salt rejection (NaCl 18%) and moderate flux (17.2 L·m−2·h−1 at 1 bar). Moreover, the composite membrane demonstrated excellent antibacterial properties (Staphylococcus aureus and E. coli). Overall, this work may present a novel approach to prepare new NF membrane.

Lipid-derived electrophiles inhibit the function of membrane channels during ferroptosis

The therapeutic targeting of ferroptosis requires full understanding of the molecular mechanism of this regulated cell death pathway. While lipid-derived electrophiles (LDEs), including 4-hydroxy-2-nonenal (4-HNE), are important biomarkers of ferroptosis, a functional role for these highly reactive species in ferroptotic cell death execution has not been established. Here, through mechanistic characterization of LDE-detoxification impairment, we demonstrate that LDEs mediate altered protein function during ferroptosis. Applying live cell fluorescence imaging, we first identified that export of glutathione-LDE-adducts through multidrug resistance-associated protein (MRP) channels is inhibited following exposure to a panel of ferroptosis inducers (FINs) with different modes of action (type I-IV FINs erastin, RSL3, FIN56, and FINO2). This channel inhibition was recreated by both initiation of lipid peroxidation and treatment with 4-HNE. Importantly, treatment with radical-trapping antioxidants prevented impaired LDE-adduct export when working with both FINs and lipid peroxidation initiators but not 4-HNE, pinpointing LDEs as the cause of this inhibited MRP activity observed during ferroptosis. Our findings, when combined with reports of widespread LDE alkylation of key proteins following ferroptosis induction, including MRP1, set a precedent for LDEs as critical mediators of ferroptotic cell damage. Lipid hydroperoxide breakdown to form truncated phospholipids and LDEs may fully explain membrane permeabilization and modified protein function downstream of lipid peroxidation, offering a unified explanation of the molecular cell death mechanism of ferroptosis.