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Autophagy Jul 2023Ferroptosis is a type of iron-dependent regulated cell death characterized by unrestricted lipid peroxidation and membrane damage. Although GPX4 (glutathione peroxidase...
Ferroptosis is a type of iron-dependent regulated cell death characterized by unrestricted lipid peroxidation and membrane damage. Although GPX4 (glutathione peroxidase 4) plays a master role in blocking ferroptosis by eliminating phospholipid hydroperoxides, the regulation of GPX4 remains poorly understood. Here, we report an unexpected role for copper in promoting ferroptotic cell death, but not cuproptosis, by inducing macroautophagic/autophagic degradation of GPX4. Copper chelators reduce ferroptosis sensitivity but do not inhibit other types of cell death, such as apoptosis, necroptosis, and alkaliptosis. Conversely, exogenous copper increases GPX4 ubiquitination and the formation of GPX4 aggregates by directly binding to GPX4 protein cysteines C107 and C148. TAX1BP1 (Tax1 binding protein 1) then acts as an autophagic receptor for GPX4 degradation and subsequent ferroptosis in response to copper stress. Consequently, copper enhances ferroptosis-mediated tumor suppression in a mouse model of pancreatic cancer tumor, whereas copper chelators attenuate experimental acute pancreatitis associated with ferroptosis. Taken together, these findings provide new insights into the link between metal stress and autophagy-dependent cell death. CALCOCO2, calcium binding and coiled-coil domain 2; GPX4, glutathione peroxidase 4; MAP1LC3A/B, microtubule associated protein 1 light chain 3 alpha/beta; MPO, myeloperoxidase; NCOA4, nuclear receptor coactivator 4; OPTN, optineurin; PDAC, pancreatic ductal adenocarcinoma; RIPK1, receptor interacting serine/threonine kinase 1; ROS, reactive oxygen species; SLC40A1, solute carrier family 40 member 1; SQSTM1, sequestosome 1; TAX1BP1, Tax1 binding protein 1; TEPA, tetraethylenepentamine; TM, tetrathiomolybdate.
Topics: Animals; Mice; Phospholipid Hydroperoxide Glutathione Peroxidase; Autophagy; Ferroptosis; Copper; Acute Disease; Pancreatitis; Apoptosis Regulatory Proteins; Chelating Agents
PubMed: 36622894
DOI: 10.1080/15548627.2023.2165323 -
Immunity Nov 2023Gasdermin D (GSDMD)-activated inflammatory cell death (pyroptosis) causes mitochondrial damage, but its underlying mechanism and functional consequences are largely...
Gasdermin D (GSDMD)-activated inflammatory cell death (pyroptosis) causes mitochondrial damage, but its underlying mechanism and functional consequences are largely unknown. Here, we show that the N-terminal pore-forming GSDMD fragment (GSDMD-NT) rapidly damaged both inner and outer mitochondrial membranes (OMMs) leading to reduced mitochondrial numbers, mitophagy, ROS, loss of transmembrane potential, attenuated oxidative phosphorylation (OXPHOS), and release of mitochondrial proteins and DNA from the matrix and intermembrane space. Mitochondrial damage occurred as soon as GSDMD was cleaved prior to plasma membrane damage. Mitochondrial damage was independent of the B-cell lymphoma 2 family and depended on GSDMD-NT binding to cardiolipin. Canonical and noncanonical inflammasome activation of mitochondrial damage, pyroptosis, and inflammatory cytokine release were suppressed by genetic ablation of cardiolipin synthase (Crls1) or the scramblase (Plscr3) that transfers cardiolipin to the OMM. Phospholipid scramblase-3 (PLSCR3) deficiency in a tumor compromised pyroptosis-triggered anti-tumor immunity. Thus, mitochondrial damage plays a critical role in pyroptosis.
Topics: Pyroptosis; Gasdermins; Neoplasm Proteins; Cardiolipins; Intracellular Signaling Peptides and Proteins; Inflammasomes
PubMed: 37924812
DOI: 10.1016/j.immuni.2023.10.004 -
Journal of Controlled Release :... Sep 2023RNA-based therapies, and siRNAs in particular, have attractive therapeutic potential for cancer treatment due to their ability to silence genes that are imperative for... (Review)
Review
RNA-based therapies, and siRNAs in particular, have attractive therapeutic potential for cancer treatment due to their ability to silence genes that are imperative for tumor progression. To be effective and solve issues related to their poor half-life and poor pharmacokinetic properties, siRNAs require adequate drug delivery systems that protect them from degradation and allow intracellular delivery. Among the various delivery vehicles available, lipid nanoparticles have emerged as the leading choice. These nanoparticles consist of cholesterol, phospholipids, PEG-lipids and most importantly ionizable cationic lipids. These ionizable lipids enable the binding of negatively charged siRNA, resulting in the formation of stable and neutral lipid nanoparticles with exceptionally high encapsulation efficiency. Lipid nanoparticles have demonstrated their effectiveness and versatility in delivering not only siRNAs but also multiple RNA molecules, contributing to their remarkable success. Furthermore, the advancement of efficient manufacturing techniques such as microfluidics, enables the rapid mixing of two miscible solvents without the need for shear forces. This facilitates the reproducible production of lipid nanoparticles and holds enormous potential for scalability. This is shown by the increasing number of preclinical and clinical trials evaluating the potential use of siRNA-LNPs for the treatment of solid and hematological tumors as well as in cancer immunotherapy. In this review, we provide an overview of the progress made on siRNA-LNP development for cancer treatment and outline the current preclinical and clinical landscape in this area. Finally, the translational challenges required to bring siRNA-LNPs further into the clinic are also discussed.
Topics: RNA, Small Interfering; Liposomes; Nanoparticles; Phospholipids; Neoplasms
PubMed: 37532145
DOI: 10.1016/j.jconrel.2023.07.054 -
Free Radical Biology & Medicine Sep 2023Trastuzumab (TRZ) is a first-line chemotherapeutic agent for HER-2 (ErbB2)-positive breast cancer. Unfortunately, its clinical use is limited due to its cardiotoxicity,...
Trastuzumab (TRZ) is a first-line chemotherapeutic agent for HER-2 (ErbB2)-positive breast cancer. Unfortunately, its clinical use is limited due to its cardiotoxicity, referred to as TRZ-induced cardiotoxicity (TIC). However, the exact molecular mechanisms underlying the development of TIC remain unclear. Iron and lipid metabolism and redox reactions participate in the development of ferroptosis. Here, we show that ferroptosis-mediated mitochondrial dysfunction is involved in TIC in vivo and in vitro. We first established TIC models with BALB/c mice or neonatal rat cardiomyocytes and confirmed cardiomyopathy with echocardiography and inhibition of cell viability with a cell counting kit-8 examination, respectively. We showed that TRZ downregulated glutathione peroxidase 4 (GPx4) and elevated lipid peroxidation by-products, 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA), by inactivating the ErbB2/PI3K/AKT/Nrf2 signalling pathway. Additionally, upregulated mitochondrial 4-HNE binds to voltage-dependent anion channel 1 (VDAC1), increases VDAC1 oligomerization, and subsequently induces mitochondrial dysfunction, as evidenced by mitochondrial permeability transition pore (mPTP) opening and decreased mitochondrial membrane potential (MMP) and ATP levels. Concomitantly, TRZ affected the mitochondrial levels of GSH/GSSG and iron ions and the stability of mitoGPx4. Ferroptosis inhibitors, such as ferrostatin-1 (Fer-1) or the iron chelator deferoxamine (DFO), ameliorate TRZ-induced cardiomyopathy. Overexpression of mitoGPx4 also suppressed mitochondrial lipid peroxidation and prevented TRZ-induced ferroptosis. Our study strongly suggests that targeting ferroptosis-mediated mitochondrial dysfunction is a potential cardioprotective strategy.
Topics: Female; Animals; Mice; Mice, Inbred BALB C; Specific Pathogen-Free Organisms; Ferroptosis; Trastuzumab; Antineoplastic Agents, Immunological; Cardiomyopathies; Rats; Myocytes, Cardiac; Iron; Lipid Peroxidation; Mitochondria; Phospholipid Hydroperoxide Glutathione Peroxidase
PubMed: 37392951
DOI: 10.1016/j.freeradbiomed.2023.06.019 -
Journal of Hepatology Jan 2024Lipids are important in multiple cellular functions, with most having structural or energy storage roles. However, a small fraction of lipids exert bioactive roles... (Review)
Review
Lipids are important in multiple cellular functions, with most having structural or energy storage roles. However, a small fraction of lipids exert bioactive roles through binding to G protein-coupled receptors and induce a plethora of processes including cell proliferation, differentiation, growth, migration, apoptosis, senescence and survival. Bioactive signalling lipids are potent modulators of metabolism and energy homeostasis, inflammation, tissue repair and malignant transformation. All these events are involved in the initiation and progression of chronic liver diseases. In this review, we focus specifically on the roles of bioactive lipids derived from phospholipids (lyso-phospholipids) and poly-unsaturated fatty acids (eicosanoids, pro-resolving lipid mediators and endocannabinoids) in prevalent chronic liver diseases (alcohol-associated liver disease, non-alcoholic fatty liver disease, viral hepatitis and hepatocellular carcinoma). We discuss the balance between pathogenic and beneficial bioactive lipids as well as potential therapeutic targets related to the agonism or antagonism of their receptors.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Liver Diseases, Alcoholic; Carcinoma, Hepatocellular; Phospholipids; Liver Neoplasms; Liver
PubMed: 37741346
DOI: 10.1016/j.jhep.2023.08.029 -
Cell Oct 2023The CD1 system binds lipid antigens for display to T cells. Here, we solved lipidomes for the four human CD1 antigen-presenting molecules, providing a map of self-lipid...
The CD1 system binds lipid antigens for display to T cells. Here, we solved lipidomes for the four human CD1 antigen-presenting molecules, providing a map of self-lipid display. Answering a basic question, the detection of >2,000 CD1-lipid complexes demonstrates broad presentation of self-sphingolipids and phospholipids. Whereas peptide antigens are chemically processed, many lipids are presented in an unaltered form. However, each type of CD1 protein differentially edits the self-lipidome to show distinct capture motifs based on lipid length and chemical composition, suggesting general antigen display mechanisms. For CD1a and CD1d, lipid size matches the CD1 cleft volume. CD1c cleft size is more variable, and CD1b is the outlier, where ligands and clefts show an extreme size mismatch that is explained by uniformly seating two small lipids in one cleft. Furthermore, the list of compounds that comprise the integrated CD1 lipidome supports the ongoing discovery of lipid blockers and antigens for T cells.
Topics: Humans; Antigen Presentation; Antigens, CD1; Lipidomics; Lipids; T-Lymphocytes; Amino Acid Motifs
PubMed: 37725977
DOI: 10.1016/j.cell.2023.08.022 -
Cell Nov 2023Wnt proteins are enzymatically lipidated by Porcupine (PORCN) in the ER and bind to Wntless (WLS) for intracellular transport and secretion. Mechanisms governing the...
Wnt proteins are enzymatically lipidated by Porcupine (PORCN) in the ER and bind to Wntless (WLS) for intracellular transport and secretion. Mechanisms governing the transfer of these low-solubility Wnts from the ER to the extracellular space remain unclear. Through structural and functional analyses of Wnt7a, a crucial Wnt involved in central nervous system angiogenesis and blood-brain barrier maintenance, we have elucidated the principles of Wnt biogenesis and Wnt7-specific signaling. The Wnt7a-WLS complex binds to calreticulin (CALR), revealing that CALR functions as a chaperone to facilitate Wnt transfer from PORCN to WLS during Wnt biogenesis. Our structures, functional analyses, and molecular dynamics simulations demonstrate that a phospholipid in the core of Wnt-bound WLS regulates the association and dissociation between Wnt and WLS, suggesting a lipid-mediated Wnt secretion mechanism. Finally, the structure of Wnt7a bound to RECK, a cell-surface Wnt7 co-receptor, reveals how RECK engages the N-terminal domain of Wnt7a to activate Wnt7-specific signaling.
Topics: Blood-Brain Barrier; Protein Binding; Receptors, G-Protein-Coupled; Wnt Signaling Pathway; Humans; Wnt Proteins
PubMed: 37852257
DOI: 10.1016/j.cell.2023.09.021 -
Circulation Research Oct 2023The membrane components of cardiomyocytes are rich in polyunsaturated fatty acids, which are easily oxidized. Thus, an efficient glutathione-based lipid redox system is...
BACKGROUND
The membrane components of cardiomyocytes are rich in polyunsaturated fatty acids, which are easily oxidized. Thus, an efficient glutathione-based lipid redox system is essential for maintaining cellular functions. However, the relationship between disruption of the redox system during ischemia-reperfusion (IR), oxidized lipid production, and consequent cell death (ferroptosis) remains unclear. We investigated the mechanisms underlying the disruption of the glutathione-mediated reduction system related to ferroptosis during IR and developed intervention strategies to suppress ferroptosis.
METHODS
In vivo fluctuations of both intra- and extracellular metabolite levels during IR were explored via microdialysis and tissue metabolome analysis. Oxidized phosphatidylcholines were assessed using liquid chromatography high-resolution mass spectrometry. The areas at risk following IR were assessed using triphenyl-tetrazolium chloride/Evans blue stain.
RESULTS
Metabolomic analysis combined with microdialysis revealed a significant release of glutathione from the ischemic region into extracellular spaces during ischemia and after reperfusion. The release of glutathione into extracellular spaces and a concomitant decrease in intracellular glutathione concentrations were also observed during anoxia-reperfusion in an in vitro cardiomyocyte model. This extracellular glutathione release was prevented by chemical inhibition or genetic suppression of glutathione transporters, mainly MRP1 (multidrug resistance protein 1). Treatment with MRP1 inhibitor reduced the intracellular reactive oxygen species levels and lipid peroxidation, thereby inhibiting cell death. Subsequent in vivo evaluation of endogenously oxidized phospholipids following IR demonstrated the involvement of ferroptosis, as levels of multiple oxidized phosphatidylcholines were significantly elevated in the ischemic region 12 hours after reperfusion. Inhibition of the MRP1 transporter also alleviated intracellular glutathione depletion in vivo and significantly reduced the generation of oxidized phosphatidylcholines. Administration of MRP1 inhibitors significantly attenuated infarct size after IR injury.
CONCLUSIONS
Glutathione was released continuously during IR, primarily in an MRP1-dependent manner, and induced ferroptosis. Suppression of glutathione release attenuated ferroptosis and reduced myocardial infarct size following IR.
Topics: Humans; Myocytes, Cardiac; Ferroptosis; Reperfusion; Ischemia; Glutathione; Phospholipids; Phosphatidylcholines
PubMed: 37818671
DOI: 10.1161/CIRCRESAHA.123.323517 -
Nature Communications Oct 2023Mitochondrial function is vital for energy metabolism in thermogenic adipocytes. Impaired mitochondrial bioenergetics in brown adipocytes are linked to disrupted...
Mitochondrial function is vital for energy metabolism in thermogenic adipocytes. Impaired mitochondrial bioenergetics in brown adipocytes are linked to disrupted thermogenesis and energy balance in obesity and aging. Phospholipid cardiolipin (CL) and phosphatidic acid (PA) jointly regulate mitochondrial membrane architecture and dynamics, with mitochondria-associated endoplasmic reticulum membranes (MAMs) serving as the platform for phospholipid biosynthesis and metabolism. However, little is known about the regulators of MAM phospholipid metabolism and their connection to mitochondrial function. We discover that LCN2 is a PA binding protein recruited to the MAM during inflammation and metabolic stimulation. Lcn2 deficiency disrupts mitochondrial fusion-fission balance and alters the acyl-chain composition of mitochondrial phospholipids in brown adipose tissue (BAT) of male mice. Lcn2 KO male mice exhibit an increase in the levels of CLs containing long-chain polyunsaturated fatty acids (LC-PUFA), a decrease in CLs containing monounsaturated fatty acids, resulting in mitochondrial dysfunction. This dysfunction triggers compensatory activation of peroxisomal function and the biosynthesis of LC-PUFA-containing plasmalogens in BAT. Additionally, Lcn2 deficiency alters PA production, correlating with changes in PA-regulated phospholipid-metabolizing enzymes and the mTOR signaling pathway. In conclusion, LCN2 plays a critical role in the acyl-chain remodeling of phospholipids and mitochondrial bioenergetics by regulating PA production and its function in activating signaling pathways.
Topics: Animals; Male; Mice; Adipocytes, Brown; Adipose Tissue, Brown; Lipocalin-2; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Plasmalogens; Thermogenesis
PubMed: 37872178
DOI: 10.1038/s41467-023-42473-2