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1.
Cell ; 177(6): 1522-1535.e14, 2019 05 30.
Article in English | MEDLINE | ID: mdl-31130380

ABSTRACT

Metabolic coordination between neurons and astrocytes is critical for the health of the brain. However, neuron-astrocyte coupling of lipid metabolism, particularly in response to neural activity, remains largely uncharacterized. Here, we demonstrate that toxic fatty acids (FAs) produced in hyperactive neurons are transferred to astrocytic lipid droplets by ApoE-positive lipid particles. Astrocytes consume the FAs stored in lipid droplets via mitochondrial ß-oxidation in response to neuronal activity and turn on a detoxification gene expression program. Our findings reveal that FA metabolism is coupled in neurons and astrocytes to protect neurons from FA toxicity during periods of enhanced activity. This coordinated mechanism for metabolizing FAs could underlie both homeostasis and a variety of disease states of the brain.


Subject(s)
Astrocytes/metabolism , Fatty Acids/metabolism , Neurons/metabolism , Animals , Apolipoproteins E/metabolism , Apolipoproteins E/physiology , Astrocytes/physiology , Brain/metabolism , Fatty Acids/toxicity , Homeostasis , Lipid Droplets/metabolism , Lipid Metabolism/physiology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria/metabolism , Oxidation-Reduction , Rats , Rats, Sprague-Dawley
2.
Cell ; 172(3): 409-422.e21, 2018 01 25.
Article in English | MEDLINE | ID: mdl-29290465

ABSTRACT

Selenoproteins are rare proteins among all kingdoms of life containing the 21st amino acid, selenocysteine. Selenocysteine resembles cysteine, differing only by the substitution of selenium for sulfur. Yet the actual advantage of selenolate- versus thiolate-based catalysis has remained enigmatic, as most of the known selenoproteins also exist as cysteine-containing homologs. Here, we demonstrate that selenolate-based catalysis of the essential mammalian selenoprotein GPX4 is unexpectedly dispensable for normal embryogenesis. Yet the survival of a specific type of interneurons emerges to exclusively depend on selenocysteine-containing GPX4, thereby preventing fatal epileptic seizures. Mechanistically, selenocysteine utilization by GPX4 confers exquisite resistance to irreversible overoxidation as cells expressing a cysteine variant are highly sensitive toward peroxide-induced ferroptosis. Remarkably, concomitant deletion of all selenoproteins in Gpx4cys/cys cells revealed that selenoproteins are dispensable for cell viability provided partial GPX4 activity is retained. Conclusively, 200 years after its discovery, a specific and indispensable role for selenium is provided.


Subject(s)
Apoptosis , Glutathione Peroxidase/metabolism , Seizures/metabolism , Selenium/metabolism , Animals , Cell Survival , Cells, Cultured , Female , Glutathione Peroxidase/genetics , HEK293 Cells , Humans , Hydrogen Peroxide/toxicity , Interneurons/metabolism , Lipid Peroxidation , Male , Mice , Mice, Inbred C57BL , Phospholipid Hydroperoxide Glutathione Peroxidase , Seizures/etiology
3.
Mol Cell ; 84(10): 1964-1979.e6, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38759628

ABSTRACT

The role of the mitochondrial electron transport chain (ETC) in regulating ferroptosis is not fully elucidated. Here, we reveal that pharmacological inhibition of the ETC complex I reduces ubiquinol levels while decreasing ATP levels and activating AMP-activated protein kinase (AMPK), the two effects known for their roles in promoting and suppressing ferroptosis, respectively. Consequently, the impact of complex I inhibitors on ferroptosis induced by glutathione peroxidase 4 (GPX4) inhibition is limited. The pharmacological inhibition of complex I in LKB1-AMPK-inactivated cells, or genetic ablation of complex I (which does not trigger apparent AMPK activation), abrogates the AMPK-mediated ferroptosis-suppressive effect and sensitizes cancer cells to GPX4-inactivation-induced ferroptosis. Furthermore, complex I inhibition synergizes with radiotherapy (RT) to selectively suppress the growth of LKB1-deficient tumors by inducing ferroptosis in mouse models. Our data demonstrate a multifaceted role of complex I in regulating ferroptosis and propose a ferroptosis-inducing therapeutic strategy for LKB1-deficient cancers.


Subject(s)
AMP-Activated Protein Kinases , Electron Transport Complex I , Ferroptosis , Phospholipid Hydroperoxide Glutathione Peroxidase , Protein Serine-Threonine Kinases , Ferroptosis/genetics , Ferroptosis/drug effects , Animals , Humans , AMP-Activated Protein Kinases/metabolism , AMP-Activated Protein Kinases/genetics , Electron Transport Complex I/metabolism , Electron Transport Complex I/genetics , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Mice , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism , Phospholipid Hydroperoxide Glutathione Peroxidase/genetics , Cell Line, Tumor , Neoplasms/genetics , Neoplasms/pathology , Neoplasms/metabolism , Neoplasms/drug therapy , AMP-Activated Protein Kinase Kinases/genetics , Mitochondria/metabolism , Mitochondria/genetics , Mitochondria/drug effects , Xenograft Model Antitumor Assays , Signal Transduction , Female
4.
Physiol Rev ; 104(1): 103-197, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37843394

ABSTRACT

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Quality of Life , Oxidative Stress/physiology , Oxidation-Reduction , Lipids
5.
Immunity ; 54(7): 1561-1577.e7, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34102100

ABSTRACT

A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here, we examined how CD8+ tumor infiltrating lymphocytes (TILs) respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8+ TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8+ TILs, which also correlated with progressive T cell dysfunction. Cd36-/- T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells, and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by overexpression of glutathione peroxidase 4 restored functionalities in CD8+ TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8+ T cell dysfunction and serves as a therapeutic avenue for immunotherapies.


Subject(s)
CD36 Antigens/metabolism , CD8-Positive T-Lymphocytes/metabolism , Lipid Peroxidation/physiology , Lipoproteins, LDL/metabolism , Neoplasms/metabolism , Receptors, Scavenger/metabolism , Animals , Biological Transport/physiology , Cell Line, Tumor , HEK293 Cells , Humans , Leukocytes, Mononuclear/metabolism , Lymphocytes, Tumor-Infiltrating/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Tumor Microenvironment/physiology
6.
Immunity ; 52(2): 374-387.e6, 2020 02 18.
Article in English | MEDLINE | ID: mdl-32075729

ABSTRACT

Animals require complex metabolic and physiological adaptations to maintain the function of vital organs in response to environmental stresses and infection. Here, we found that infection or injury in Drosophila induced the excretion of hemolymphatic lipids by Malpighian tubules, the insect kidney. This lipid purge was mediated by a stress-induced lipid-binding protein, Materazzi, which was enriched in Malpighian tubules. Flies lacking materazzi had higher hemolymph concentrations of reactive oxygen species (ROS) and increased lipid peroxidation. These flies also displayed Malpighian tubule dysfunction and were susceptible to infections and environmental stress. Feeding flies with antioxidants rescued the materazzi phenotype, indicating that the main role of Materazzi is to protect the organism from damage caused by stress-induced ROS. Our findings suggest that purging hemolymphatic lipids presents a physiological adaptation to protect host tissues from excessive ROS during immune and stress responses, a process that is likely to apply to other organisms.


Subject(s)
Drosophila melanogaster/immunology , Hemolymph/metabolism , Lipid Metabolism/immunology , Malpighian Tubules/immunology , Reactive Oxygen Species/immunology , Adaptive Immunity , Animals , Carrier Proteins/chemistry , Carrier Proteins/genetics , Carrier Proteins/metabolism , Diglycerides/metabolism , Drosophila Proteins/chemistry , Drosophila Proteins/deficiency , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Feces/chemistry , Lipid Peroxidation/immunology , MAP Kinase Signaling System/immunology , Malpighian Tubules/metabolism , Protein Conformation , Reactive Oxygen Species/metabolism , Stress, Physiological/immunology
7.
Circ Res ; 134(10): 1292-1305, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38618716

ABSTRACT

BACKGROUND: During myocardial ischemia/reperfusion (I/R) injury, high levels of matrix Ca2+ and reactive oxygen species (ROS) induce the opening of the mitochondrial permeability transition pore (mPTP), which causes mitochondrial dysfunction and ultimately necrotic death. However, the mechanisms of how these triggers individually or cooperatively open the pore have yet to be determined. METHODS: Here, we use a combination of isolated mitochondrial assays and in vivo I/R surgery in mice. We challenged isolated liver and heart mitochondria with Ca2+, ROS, and Fe2+ to induce mitochondrial swelling. Using inhibitors of the mPTP (cyclosporine A or ADP) lipid peroxidation (ferrostatin-1, MitoQ), we determined how the triggers elicit mitochondrial damage. Additionally, we used the combination of inhibitors during I/R injury in mice to determine if dual inhibition of these pathways is additivity protective. RESULTS: In the absence of Ca2+, we determined that ROS fails to trigger mPTP opening. Instead, high levels of ROS induce mitochondrial dysfunction and rupture independently of the mPTP through lipid peroxidation. As expected, Ca2+ in the absence of ROS induces mPTP-dependent mitochondrial swelling. Subtoxic levels of ROS and Ca2+ synergize to induce mPTP opening. Furthermore, this synergistic form of Ca2+- and ROS-induced mPTP opening persists in the absence of CypD (cyclophilin D), suggesting the existence of a CypD-independent mechanism for ROS sensitization of the mPTP. These ex vivo findings suggest that mitochondrial dysfunction may be achieved by multiple means during I/R injury. We determined that dual inhibition of the mPTP and lipid peroxidation is significantly more protective against I/R injury than individually targeting either pathway alone. CONCLUSIONS: In the present study, we have investigated the relationship between Ca2+ and ROS, and how they individually or synergistically induce mitochondrial swelling. Our findings suggest that Ca2+ mediates mitochondrial damage through the opening of the mPTP, although ROS mediates its damaging effects through lipid peroxidation. However, subtoxic levels both Ca2+ and ROS can induce mPTP-mediated mitochondrial damage. Targeting both of these triggers to preserve mitochondria viability unveils a highly effective therapeutic approach for mitigating I/R injury.


Subject(s)
Lipid Peroxidation , Mice, Inbred C57BL , Mitochondria, Heart , Mitochondria, Liver , Mitochondrial Membrane Transport Proteins , Mitochondrial Permeability Transition Pore , Myocardial Reperfusion Injury , Reactive Oxygen Species , Animals , Lipid Peroxidation/drug effects , Mitochondrial Permeability Transition Pore/metabolism , Reactive Oxygen Species/metabolism , Mice , Mitochondria, Heart/metabolism , Mitochondria, Heart/drug effects , Mitochondria, Heart/pathology , Male , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/prevention & control , Myocardial Reperfusion Injury/pathology , Mitochondrial Membrane Transport Proteins/metabolism , Mitochondria, Liver/metabolism , Mitochondria, Liver/pathology , Mitochondria, Liver/drug effects , Calcium/metabolism , Mitochondrial Swelling/drug effects
8.
Proc Natl Acad Sci U S A ; 120(25): e2218896120, 2023 Jun 20.
Article in English | MEDLINE | ID: mdl-37327313

ABSTRACT

Programmed ferroptotic death eliminates cells in all major organs and tissues with imbalanced redox metabolism due to overwhelming iron-catalyzed lipid peroxidation under insufficient control by thiols (Glutathione (GSH)). Ferroptosis has been associated with the pathogenesis of major chronic degenerative diseases and acute injuries of the brain, cardiovascular system, liver, kidneys, and other organs, and its manipulation offers a promising new strategy for anticancer therapy. This explains the high interest in designing new small-molecule-specific inhibitors against ferroptosis. Given the role of 15-lipoxygenase (15LOX) association with phosphatidylethanolamine (PE)-binding protein 1 (PEBP1) in initiating ferroptosis-specific peroxidation of polyunsaturated PE, we propose a strategy of discovering antiferroptotic agents as inhibitors of the 15LOX/PEBP1 catalytic complex rather than 15LOX alone. Here we designed, synthesized, and tested a customized library of 26 compounds using biochemical, molecular, and cell biology models along with redox lipidomic and computational analyses. We selected two lead compounds, FerroLOXIN-1 and 2, which effectively suppressed ferroptosis in vitro and in vivo without affecting the biosynthesis of pro-/anti-inflammatory lipid mediators in vivo. The effectiveness of these lead compounds is not due to radical scavenging or iron-chelation but results from their specific mechanisms of interaction with the 15LOX-2/PEBP1 complex, which either alters the binding pose of the substrate [eicosatetraenoyl-PE (ETE-PE)] in a nonproductive way or blocks the predominant oxygen channel thus preventing the catalysis of ETE-PE peroxidation. Our successful strategy may be adapted to the design of additional chemical libraries to reveal new ferroptosis-targeting therapeutic modalities.


Subject(s)
Ferroptosis , Phosphatidylethanolamine Binding Protein , Glutathione/metabolism , Iron/metabolism , Lipid Peroxidation , Lipids , Oxidation-Reduction , Phosphatidylethanolamine Binding Protein/antagonists & inhibitors
9.
Genes Dev ; 32(9-10): 602-619, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29802123

ABSTRACT

Lipid peroxidation is the process by which oxygen combines with lipids to generate lipid hydroperoxides via intermediate formation of peroxyl radicals. Vitamin E and coenzyme Q10 react with peroxyl radicals to yield peroxides, and then these oxidized lipid species can be detoxified by glutathione and glutathione peroxidase 4 (GPX4) and other components of the cellular antioxidant defense network. Ferroptosis is a form of regulated nonapoptotic cell death involving overwhelming iron-dependent lipid peroxidation. Here, we review the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea. We also discuss the potential evolutionary roles of lipid peroxidation and ferroptosis.


Subject(s)
Antioxidants/metabolism , Biological Evolution , Cell Death/physiology , Iron/metabolism , Lipid Peroxidation , Animals , Humans , Reactive Oxygen Species/metabolism , Species Specificity
10.
Traffic ; 24(9): 384-396, 2023 09.
Article in English | MEDLINE | ID: mdl-37341018

ABSTRACT

Iron homeostasis is crucial for maintaining proper cellular function, and its disruption is considered one of the pathogenic mechanisms underlying musculoskeletal diseases. Under conditions of oxidative stress, the accumulation of cellular iron overload and lipid peroxidation can lead to ferroptosis. Extracellular vesicles (EVs), serving as mediators in the cell-to-cell communication, play an important role in regulating the outcome of cell ferroptosis. Growing evidence has proven that EV biogenesis and secretion are tightly associated with cellular iron export. Furthermore, different sources of EVs deliver diverse cargoes to bring about phenotypic changes in the recipient cells, either activating or inhibiting ferroptosis. Thus, delivering therapies targeting ferroptosis through EVs may hold significant potential for treating musculoskeletal diseases. This review aims to summarize current knowledge on the role of EVs in iron homeostasis and ferroptosis, as well as their therapeutic applications in musculoskeletal diseases, and thereby provide valuable insights for both research and clinical practice.


Subject(s)
Extracellular Vesicles , Ferroptosis , Musculoskeletal Diseases , Humans , Iron , Musculoskeletal Diseases/therapy , Homeostasis
11.
J Biol Chem ; 300(5): 107259, 2024 May.
Article in English | MEDLINE | ID: mdl-38582453

ABSTRACT

Selenoprotein I (SELENOI) catalyzes the final reaction of the CDP-ethanolamine branch of the Kennedy pathway, generating the phospholipids phosphatidylethanolamine (PE) and plasmenyl-PE. Plasmenyl-PE is a key component of myelin and is characterized by a vinyl ether bond that preferentially reacts with oxidants, thus serves as a sacrificial antioxidant. In humans, multiple loss-of-function mutations in genes affecting plasmenyl-PE metabolism have been implicated in hereditary spastic paraplegia, including SELENOI. Herein, we developed a mouse model of nervous system-restricted SELENOI deficiency that circumvents embryonic lethality caused by constitutive deletion and recapitulates phenotypic features of hereditary spastic paraplegia. Resulting mice exhibited pronounced alterations in brain lipid composition, which coincided with motor deficits and neuropathology including hypomyelination, elevated reactive gliosis, and microcephaly. Further studies revealed increased lipid peroxidation in oligodendrocyte lineage cells and disrupted oligodendrocyte maturation both in vivo and in vitro. Altogether, these findings detail a critical role for SELENOI-derived plasmenyl-PE in myelination that is of paramount importance for neurodevelopment.


Subject(s)
Homeostasis , Lipid Metabolism , Myelin Sheath , Oligodendroglia , Selenoproteins , Animals , Humans , Mice , Brain/metabolism , Brain/pathology , Lipid Peroxidation , Mice, Knockout , Myelin Sheath/metabolism , Oligodendroglia/metabolism , Oligodendroglia/pathology , Phosphatidylethanolamines/metabolism , Phospholipid Ethers/metabolism , Plasmalogens/metabolism , Selenoproteins/metabolism , Selenoproteins/genetics , Spastic Paraplegia, Hereditary/metabolism , Spastic Paraplegia, Hereditary/genetics , Spastic Paraplegia, Hereditary/pathology
12.
J Biol Chem ; 300(4): 107168, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38490434

ABSTRACT

Lipids have been previously implicated in the lifecycle of neuroinvasive viruses. However, the role of lipids in programmed cell death and the relationship between programmed cell death and lipid droplets (LDs) in neuroinvasive virus infection remains unclear. Here, we found that the infection of neuroinvasive virus, such as rabies virus and encephalomyocarditis virus could enhance the LD formation in N2a cells, and decreasing LDs production by targeting diacylglycerol acyltransferase could suppress viral replication. The lipidomics analysis revealed that arachidonic acid (AA) was significantly increased after reducing LD formation by restricting diacylglycerol acyltransferase, and AA was further demonstrated to induce ferroptosis to inhibit neuroinvasive virus replication. Moreover, lipid peroxidation and viral replication inhibition could be significantly alleviated by a ferroptosis inhibitor, ferrostatin-1, indicating that AA affected neuroinvasive virus replication mainly through inducing ferroptosis. Furthermore, AA was demonstrated to activate the acyl-CoA synthetase long-chain family member 4-lysophosphatidylcholine acyltransferase 3-cytochrome P450 oxidoreductase axis to induce ferroptosis. Our findings highlight novel cross-talks among viral infection, LDs, and ferroptosis for the first time, providing a potential target for antiviral drug development.


Subject(s)
Arachidonic Acid , Ferroptosis , Lipid Droplets , Virus Replication , Ferroptosis/drug effects , Lipid Droplets/metabolism , Lipid Droplets/drug effects , Animals , Virus Replication/drug effects , Mice , Arachidonic Acid/metabolism , Arachidonic Acid/pharmacology , Encephalomyocarditis virus/drug effects , Diacylglycerol O-Acyltransferase/metabolism , Diacylglycerol O-Acyltransferase/antagonists & inhibitors , Lipid Peroxidation/drug effects , Coenzyme A Ligases/metabolism , Cell Line, Tumor , Humans
13.
J Biol Chem ; : 107583, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39025451

ABSTRACT

Ferroptosis is an iron-dependent cell death mechanism that may be important to prevent tumor formation and useful as a target for new cancer therapies. Transcriptional networks play a crucial role in shaping ferroptosis sensitivity by regulating the expression of transporters, metabolic enzymes, and other proteins. The Cap'n'collar (CNC) protein nuclear factor erythroid 2 like 2 (NFE2L2, also known as NRF2) is a key regulator of ferroptosis in many cells and contexts. Emerging evidence indicates that the related CNC family members BTB and CNC homology 1 (BACH1) and nuclear factor erythroid 2 like 1 (NFE2L1) also have non-redundant roles in ferroptosis regulation. Here, we comprehensively review the role of CNC transcription factors in governing cellular sensitivity to ferroptosis. We describe how CNC family members regulate ferroptosis sensitivity through modulation of iron, lipid, and redox metabolism. We also use examples of ferroptosis regulation by CNC proteins to illustrate the flexible and highly context-dependent nature of the ferroptosis mechanism between cells and conditions.

14.
Physiology (Bethesda) ; 39(2): 73-87, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38193763

ABSTRACT

Ferroptosis, a regulated cell death hallmarked by excessive lipid peroxidation, is implicated in various (patho)physiological contexts. During ferroptosis, lipid peroxidation leads to a diverse change in membrane properties and the dysregulation of ion homeostasis via the cation channels, ultimately resulting in plasma membrane rupture. This review illuminates cellular membrane dynamics and cation handling in ferroptosis regulation.


Subject(s)
Ferroptosis , Humans , Lipid Peroxidation
15.
FASEB J ; 38(2): e23401, 2024 01 31.
Article in English | MEDLINE | ID: mdl-38236196

ABSTRACT

Ferroptosis, a type of iron-catalyzed necrosis, is responsible for vascular smooth muscle cell (VSMC) death and serves as a potential therapeutic target for alleviating aortic aneurysm. Here, our study explored the underlying mechanism of ferroptosis affecting VSMC functions and the resultant formation of AAA using its inhibitor Ferrostatin-1 (Fer-1). Microarray-based gene expression profiling was employed to identify differentially expressed genes related to AAA and ferroptosis. An AAA model was established by angiotensin II (Ang II) induction in apolipoprotein E-knockout (ApoE-/- ) mice, followed by injection of Fer-1 and RSL-3 (ferroptosis inducer). Then, the role of Fer-1 and RSL-3 in the ferroptosis of VSMCs and AAA formation was analyzed in Ang II-induced mice. Primary mouse VSMCs were cultured in vitro and treated with Ang II, Fer-1, sh-SLC7A11, or sh-GPX4 to assess the effect of Fer-1 via the SLC7A11/GPX axis. Bioinformatics analysis revealed that GPX4 was involved in the fibrosis formation of AAA, and there was an interaction between SLC7A11 and GPX4. In vitro assays showed that Fer-1 alleviated Ang II-induced ferroptosis of VSMCs and retard the consequent AAA formation. The mechanism was associated with activation of the SLC7A11/GPX4 pathway. Silencing of SLC7A11 or GPX4 could inhibit the ameliorating effect of Fer-1 on the ferroptosis of VSMCs. In vivo animal studies further demonstrated that Fer-1 inhibited Ang II-induced ferroptosis and vessel wall structural abnormalities in AAA mouse through activation of the SLC7A11/GPX4 pathway. Fer-1 may prevent AAA formation through activation of the SLC7A11/GPX4 pathway.


Subject(s)
Aortic Aneurysm, Abdominal , Ferroptosis , Peptide Hormones , Phenylenediamines , Animals , Mice , Muscle, Smooth, Vascular , Aortic Aneurysm, Abdominal/chemically induced , Aortic Aneurysm, Abdominal/prevention & control , Cyclohexylamines/pharmacology , Angiotensin II/pharmacology
16.
Bioessays ; 45(3): e2200210, 2023 03.
Article in English | MEDLINE | ID: mdl-36585363

ABSTRACT

Fatty acids (FAs) are well known to serve as substrates for reactions that provide cells with membranes and energy. In contrast to these metabolic reactions, the physiological importance of FAs themselves known as free FAs (FFAs) in cells remains obscure. Since accumulation of FFAs in cells is toxic, cells must develop mechanisms to detoxify FFAs. One such mechanism is to sequester free polyunsaturated FAs (PUFAs) into a droplet-like structure assembled by Fas-Associated Factor 1 (FAF1), a cytosolic protein. This sequestration limits access of PUFAs to Fe2+ , thereby preventing Fe2+ -catalyzed PUFA peroxidation. Consequently, assembly of the FAF1-FFA complex is critical to protect cells from ferroptosis, a cell death pathway triggered by PUFA peroxidation. The observations that free PUFAs in cytosol are not randomly diffused but rather sequestered into a membraneless complex should open new directions to explore signaling pathways by which FFAs regulate cellular physiology.


Subject(s)
Fatty Acids, Nonesterified , Fatty Acids, Unsaturated , Fatty Acids, Unsaturated/metabolism , Signal Transduction , Cell Death , Fatty Acids
17.
Proc Natl Acad Sci U S A ; 119(26): e2121987119, 2022 06 28.
Article in English | MEDLINE | ID: mdl-35749365

ABSTRACT

Mechanisms of defense against ferroptosis (an iron-dependent form of cell death induced by lipid peroxidation) in cellular organelles remain poorly understood, hindering our ability to target ferroptosis in disease treatment. In this study, metabolomic analyses revealed that treatment of cancer cells with glutathione peroxidase 4 (GPX4) inhibitors results in intracellular glycerol-3-phosphate (G3P) depletion. We further showed that supplementation of cancer cells with G3P attenuates ferroptosis induced by GPX4 inhibitors in a G3P dehydrogenase 2 (GPD2)-dependent manner; GPD2 deletion sensitizes cancer cells to GPX4 inhibition-induced mitochondrial lipid peroxidation and ferroptosis, and combined deletion of GPX4 and GPD2 synergistically suppresses tumor growth by inducing ferroptosis in vivo. Mechanistically, inner mitochondrial membrane-localized GPD2 couples G3P oxidation with ubiquinone reduction to ubiquinol, which acts as a radical-trapping antioxidant to suppress ferroptosis in mitochondria. Taken together, these results reveal that GPD2 participates in ferroptosis defense in mitochondria by generating ubiquinol.


Subject(s)
Ferroptosis , Glycerolphosphate Dehydrogenase , Lipid Peroxidation , Mitochondria , Mitochondrial Proteins , Neoplasms , Cell Line, Tumor , Ferroptosis/genetics , Glycerolphosphate Dehydrogenase/antagonists & inhibitors , Glycerolphosphate Dehydrogenase/genetics , Glycerolphosphate Dehydrogenase/metabolism , Humans , Lipid Peroxidation/genetics , Mitochondria/enzymology , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Neoplasms/enzymology , Neoplasms/pathology , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism
18.
J Cell Mol Med ; 28(7): e18212, 2024 04.
Article in English | MEDLINE | ID: mdl-38516826

ABSTRACT

SBFI26, an inhibitor of FABP5, has been shown to suppress the proliferation and metastasis of tumour cells. However, the underlying mechanism by which SBFI26 induces ferroptosis in breast cancer cells remains largely unknown. Three breast cancer cell lines were treated with SBFI26 and CCK-8 assessed cytotoxicity. Transcriptome was performed on the Illumina platform and verified by qPCR. Western blot evaluated protein levels. Malondialdehyde (MDA), total superoxide dismutase (T-SOD), Fe, glutathione (GSH) and oxidized glutathione (GSSG) were measured. SBFI26 induced cell death time- and dose-dependent, with a more significant inhibitory effect on MDA-MB-231 cells. Fer-1, GSH and Vitamin C attenuated the effects but not erastin. RNA-Seq analysis revealed that SBFI26 treatment significantly enriched differentially expressed genes related to ferroptosis. Furthermore, SBFI26 increased intracellular MDA, iron ion, and GSSG levels while decreasing T-SOD, total glutathione (T-GSH), and GSH levels.SBFI26 dose-dependently up-regulates the expression of HMOX1 and ALOX12 at both gene and protein levels, promoting ferroptosis. Similarly, it significantly increases the expression of SAT1, ALOX5, ALOX15, ALOXE3 and CHAC1 that, promoting ferroptosis while downregulating the NFE2L2 gene and protein that inhibit ferroptosis. SBFI26 leads to cellular accumulation of fatty acids, which triggers excess ferrous ions and subsequent lipid peroxidation for inducing ferroptosis.


Subject(s)
Ferroptosis , Triple Negative Breast Neoplasms , Humans , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Glutathione Disulfide , Ferroptosis/genetics , Lipid Peroxidation , Glutathione , Iron , Superoxide Dismutase/genetics , Reactive Oxygen Species , Fatty Acid-Binding Proteins
19.
J Cell Mol Med ; 28(1): e18044, 2024 01.
Article in English | MEDLINE | ID: mdl-38140764

ABSTRACT

Breast cancer is the most prevalent cancer worldwide and its incidence increases with age, posing a significant threat to women's health globally. Due to the clinical heterogeneity of breast cancer, the majority of patients develop drug resistance and metastasis following treatment. Ferroptosis, a form of programmed cell death dependent on iron, is characterized by the accumulation of lipid peroxides, elevated levels of iron ions and lipid peroxidation. The underlying mechanisms and signalling pathways associated with ferroptosis are intricate and interconnected, involving various proteins and enzymes such as the cystine/glutamate antiporter, glutathione peroxidase 4, ferroptosis inhibitor 1 and dihydroorotate dehydrogenase. Consequently, emerging research suggests that ferroptosis may offer a novel target for breast cancer treatment; however, the mechanisms of ferroptosis in breast cancer urgently require resolution. Additionally, certain natural compounds have been reported to induce ferroptosis, thereby interfering with breast cancer. Therefore, this review not only discusses the molecular mechanisms of multiple signalling pathways that mediate ferroptosis in breast cancer (including metastasis, invasion and proliferation) but also elaborates on the mechanisms by which natural compounds induce ferroptosis in breast cancer. Furthermore, this review summarizes potential compound types that may serve as ferroptosis inducers in future tumour cells, providing lead compounds for the development of ferroptosis-inducing agents. Last, this review proposes the potential synergy of combining natural compounds with traditional breast cancer drugs in the treatment of breast cancer, thereby suggesting future directions and offering new insights.


Subject(s)
Breast Neoplasms , Ferroptosis , Humans , Female , Apoptosis , Glutamic Acid , Iron , Lipid Peroxidation
20.
J Cell Mol Med ; 28(3): e18076, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38088220

ABSTRACT

Ferroptosis, characterized by lipid accumulation in intracellular compartments, is related to acute kidney injury (AKI), but the mechanism remains obscure. In our previous study, the protective effect of augmenter of liver regeneration (ALR) on AKI was not fully clarified. In this study, we established an AKI mouse model by knocking out proximal tubule-specific ALR and an AKI cell model by inducing hypoxia, as well as enrolled AKI patients, to investigate the effects of ALR on ferroptosis and the progression of AKI. We found that ALR knockout aggravated ferroptosis and increased ROS accumulation and mitochondrial damage, whereas ALR overexpression attenuated ferroptosis through clearance of ROS and maintenance of mitochondrial morphology. Mechanistically, we demonstrated that ALR could directly bind to long-chain-fatty-acid-CoA ligase 4 (ACSL4) and further inhibit the expression of ACSL4 by interacting with certain regions. By resolution liquid chromatography coupled with triple quadruple mass spectrometry, we found that ALR could reduce the contents of polyunsaturated fatty acids, especially arachidonic acid. In addition, we showed that ALR binds to ACSL4 and attenuates oxylipin accumulation, exerting a protective effect against ferroptosis in AKI. Therefore, targeting renal ALR can attenuate ferroptosis and can offer a promising strategy for the treatment of AKI.


Subject(s)
Acute Kidney Injury , Ferroptosis , Animals , Humans , Mice , Acute Kidney Injury/metabolism , Apoptosis , Ligases , Liver Regeneration , Reactive Oxygen Species/metabolism
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