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1.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 49(2): 286-295, 2024 Feb 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38755725

RESUMO

Bladder cancer (BC) is one of the 3 common malignant tumors in the urinary system, with high incidence, easy metastasis, poor therapeutic efficacy, and poor prognosis, which seriously threatens the health of human. Tumor cells exhibit a strong demand for iron, and iron overload can induce ferroptosis, which is an iron dependent cell death caused by lipid peroxidation and cell membrane damage. Therefore, ferroptosis has strong anti-tumor potential. The molecular mechanisms of ferroptosis is associated with abnormalities in cellular phospholipid metabolism and iron metabolism, and dysregulation of antioxidant and non-antioxidant systems Xc-/glutathione (GSH)/glutathione peroxidase 4 (GPX4). Ferroptosis relevant molecules play important roles in the occurrence and development, metastasis, drug resistance, and immune response of BC, and are expected to become targets for the treatment of BC.


Assuntos
Ferroptose , Ferro , Peroxidação de Lipídeos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/genética , Ferro/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Glutationa/metabolismo , Antioxidantes/metabolismo , Fosfolipídeos/metabolismo , Sistema y+ de Transporte de Aminoácidos/metabolismo , Sistema y+ de Transporte de Aminoácidos/genética
2.
ACS Synth Biol ; 13(5): 1549-1561, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632869

RESUMO

ATP is a universal energy currency that is essential for life. l-Arginine degradation via deamination is an elegant way to generate ATP in synthetic cells, which is currently limited by a slow l-arginine/l-ornithine exchange. We are now implementing a new antiporter with better kinetics to obtain faster ATP recycling. We use l-arginine-dependent ATP formation for the continuous synthesis and export of glycerol 3-phosphate by including glycerol kinase and the glycerol 3-phosphate/Pi antiporter. Exported glycerol 3-phosphate serves as a precursor for the biosynthesis of phospholipids in a second set of vesicles, which forms the basis for the expansion of the cell membrane. We have therefore developed an out-of-equilibrium metabolic network for ATP recycling, which has been coupled to lipid synthesis. This feeder-utilizer system serves as a proof-of-principle for the systematic buildup of synthetic cells, but the vesicles can also be used to study the individual reaction networks in confinement.


Assuntos
Trifosfato de Adenosina , Arginina , Trifosfato de Adenosina/metabolismo , Arginina/metabolismo , Células Artificiais/metabolismo , Glicerofosfatos/metabolismo , Glicerol Quinase/metabolismo , Glicerol Quinase/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Lipídeos/biossíntese , Fosfolipídeos/metabolismo , Redes e Vias Metabólicas
3.
Nat Cell Biol ; 26(5): 811-824, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38671262

RESUMO

The mechanisms underlying the dynamic remodelling of cellular membrane phospholipids to prevent phospholipid peroxidation-induced membrane damage and evade ferroptosis, a non-apoptotic form of cell death driven by iron-dependent lipid peroxidation, remain poorly understood. Here we show that lysophosphatidylcholine acyltransferase 1 (LPCAT1) plays a critical role in ferroptosis resistance by increasing membrane phospholipid saturation via the Lands cycle, thereby reducing membrane levels of polyunsaturated fatty acids, protecting cells from phospholipid peroxidation-induced membrane damage and inhibiting ferroptosis. Furthermore, the enhanced in vivo tumour-forming capability of tumour cells is closely associated with the upregulation of LPCAT1 and emergence of a ferroptosis-resistant state. Combining LPCAT1 inhibition with a ferroptosis inducer synergistically triggers ferroptosis and suppresses tumour growth. Therefore, our results unveil a plausible role for LPCAT1 in evading ferroptosis and suggest it as a promising target for clinical intervention in human cancer.


Assuntos
1-Acilglicerofosfocolina O-Aciltransferase , Ferroptose , Fosfolipídeos , Humanos , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/genética , Animais , Fosfolipídeos/metabolismo , Linhagem Celular Tumoral , Peroxidação de Lipídeos , Camundongos Nus , Membrana Celular/metabolismo , Camundongos , Neoplasias/patologia , Neoplasias/metabolismo , Neoplasias/genética , Proliferação de Células
4.
Curr Opin Struct Biol ; 86: 102813, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38598982

RESUMO

Oxidative stress leads to the production of oxidized phospholipids (oxPLs) that modulate the biophysical properties of phospholipid monolayers and bilayers. As many immune cells are responsible for surveilling cells and tissues for the presence of oxPLs, oxPL-dependent mechanisms have been suggested as targets for treating chronic kidney disease, atherosclerosis, diabetes, and cancer metastasis. This review details recent experimental and computational studies that characterize oxPLs' behaviors in various monolayers and bilayers. These studies investigate how the tail length and polar functional groups of OxPLs impact membrane properties, how oxidized membranes can be stabilized, and how membrane integrity is generally affected by oxidized lipids. In addition, for oxPL-containing membrane modeling and simulation, CHARMM-GUI Membrane Builder has been extended to support a variety of oxPLs, accelerating the simulation system building process for these biologically relevant lipid bilayers.


Assuntos
Bicamadas Lipídicas , Oxirredução , Fosfolipídeos , Fosfolipídeos/metabolismo , Fosfolipídeos/química , Bicamadas Lipídicas/metabolismo , Bicamadas Lipídicas/química , Humanos , Membrana Celular/metabolismo , Membrana Celular/química , Simulação de Dinâmica Molecular , Modelos Moleculares
5.
FASEB J ; 38(8): e23619, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38661031

RESUMO

Exosomes, which are small membrane-encapsulated particles derived from all cell types, are emerging as important mechanisms for intercellular communication. In addition, exosomes are currently envisioned as potential carriers for the delivery of drugs to target tissues. The natural population of exosomes is very variable due to the limited amount of cargo components present in these small vesicles. Consequently, common components of exosomes may play a role in their function. We have proposed that membrane phospholipids could be a common denominator in the effect of exosomes on cellular functions. In this regard, we have previously shown that liposomes made of phosphatidylcholine (PC) or phosphatidylserine (PS) induced a robust alteration of macrophage (Mϕ) gene expression. We herewith report that these two phospholipids modulate gene expression in Mϕs by different mechanisms. PS alters cellular responses by the interaction with surface receptors, particularly CD36. In contrast, PC is captured by a receptor-independent process and likely triggers an activity within endocytic vesicles. Despite this difference in the capture mechanisms, both lipids mounted similar gene expression responses. This investigation suggests that multiple mechanisms mediated by membrane phospholipids could be participating in the alteration of cellular functions by exosomes.


Assuntos
Exossomos , Macrófagos , Fosfatidilserinas , Macrófagos/metabolismo , Animais , Camundongos , Fosfatidilserinas/metabolismo , Exossomos/metabolismo , Fosfatidilcolinas/metabolismo , Inflamação/metabolismo , Fosfolipídeos/metabolismo , Camundongos Endogâmicos C57BL , Antígenos CD36/metabolismo , Antígenos CD36/genética , Lipossomos
6.
Cells ; 13(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38667329

RESUMO

In the last three decades, the presence of phospholipids in the nucleus has been shown and thoroughly investigated. A considerable amount of interest has been raised about nuclear inositol lipids, mainly because of their role in signaling acting. Here, we review the main issues of nuclear phospholipid localization and the role of nuclear inositol lipids and their related enzymes in cellular signaling, both in physiological and pathological conditions.


Assuntos
Núcleo Celular , Fosfolipídeos , Transdução de Sinais , Humanos , Núcleo Celular/metabolismo , Fosfolipídeos/metabolismo , Animais
7.
Environ Pollut ; 349: 123904, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38565392

RESUMO

The indiscriminate and, very often, incorrect use of pesticides in Brazil, as well as in other countries, results in severe levels of environmental pollution and intoxication of human life. Herein, we studied plasma membrane models (monolayer and bilayer) of the phospholipid Dioleoyl-sn-glycerol-3-phosphocholine (DOPC) using Langmuir films, and large (LUVs) and giant (GUVs) unilamellar vesicles, to determine the effect of the pesticides chlorantraniliprole (CLTP), isoxaflutole (ISF), and simazine (SMZ), used in sugarcane. CLTP affects the lipid organization of the bioinspired models of DOPC π-A isotherms, while ISF and SMZ pesticides significantly affect the LUVs and GUVs. Furthermore, the in vivo study of the gill tissue in fish in the presence of pesticides (2.0 × 10-10 mol/L for CLTP, 8.3 × 10-9 mol/L for ISF, and SMZ at 9.9 × 10-9 mol/L) was performed using optical and fluorescence images. This investigation was motivated by the gill lipid membranes, which are vital for regulating transporter activity through transmembrane proteins, crucial for maintaining ionic balance in fish gills. In this way, the presence of phospholipids in gills offers a model for understanding their effects on fish health. Histological results show that exposure to CLTP, ISF, and SMZ may interfere with vital gill functions, leading to respiratory disorders and osmoregulation dysfunction. The results indicate that exposure to pesticides caused severe morphological alterations in fish, which could be correlated with their impact on the bioinspired membrane models. Moreover, the effect does not depend on the exposure period (24h and 96h), showing that animals exposed to pesticides for a short period suffer irreparable damage to gill tissue. In summary, we can conclude that the harm caused by pesticides, both in membrane models and in fish gills, occurs due to contamination of the aquatic system with pesticides. Therefore, water quality is vital for the preservation of ecosystems.


Assuntos
Brânquias , Praguicidas , Fosfolipídeos , Tilápia , ortoaminobenzoatos , Animais , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Fosfolipídeos/metabolismo , Praguicidas/toxicidade , Tilápia/metabolismo , ortoaminobenzoatos/toxicidade , Poluentes Químicos da Água/toxicidade , Membrana Celular/efeitos dos fármacos , Brasil
8.
Sci Signal ; 17(827): eade3643, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470955

RESUMO

Activation of the endoplasmic reticulum (ER)-resident adaptor protein STING, a component of a cytosolic DNA-sensing pathway, induces the transcription of genes encoding type I interferons (IFNs) and other proinflammatory factors. Because STING is activated at the Golgi apparatus, control of the localization and activation of STING is important in stimulating antiviral and antitumor immune responses. Through a genome-wide CRISPR interference screen, we found that STING activation required the Golgi-resident protein ACBD3, which promotes the generation of phosphatidylinositol 4-phosphate (PI4P) at the trans-Golgi network, as well as other PI4P-associated proteins. Appropriate localization and activation of STING at the Golgi apparatus required ACBD3 and the PI4P-generating kinase PI4KB. In contrast, STING activation was enhanced when the lipid-shuttling protein OSBP, which removes PI4P from the Golgi apparatus, was inhibited by the US Food and Drug Administration-approved antifungal itraconazole. The increase in the abundance of STING-activating phospholipids at the trans-Golgi network resulted in the increased production of IFN-ß and other cytokines in THP-1 cells. Furthermore, a mutant STING that could not bind to PI4P failed to traffic from the ER to the Golgi apparatus in response to a STING agonist, whereas forced relocalization of STING to PI4P-enriched areas elicited STING activation in the absence of stimulation with a STING agonist. Thus, PI4P is critical for STING activation, and manipulating PI4P abundance may therapeutically modulate STING-dependent immune responses.


Assuntos
Complexo de Golgi , Fosfolipídeos , Fosfolipídeos/metabolismo , Complexo de Golgi/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
9.
Microbiol Spectr ; 12(5): e0047024, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38501821

RESUMO

Bacterial lipoproteins are post-translationally modified by the addition of acyl chains that anchor the protein to bacterial membranes. This modification includes two ester-linked and one amide-linked acyl chain on lipoproteins from Gram-negative bacteria. Helicobacter pylori lipoproteins have important functions in pathogenesis (including delivering the CagA oncoprotein to mammalian cells) and are recognized by host innate and adaptive immune systems. The number and variety of acyl chains on lipoproteins impact the innate immune response through Toll-like receptor 2. The acyl chains added to lipoproteins are derived from membrane phospholipids. H. pylori membrane phospholipids have previously been shown to consist primarily of C14:0 and C19:0 cyclopropane-containing acyl chains. However, the acyl composition of H. pylori lipoproteins has not been determined. In this study, we characterized the acyl composition of two representative H. pylori lipoproteins, Lpp20 and CagT. Fatty acid methyl esters were prepared from both purified lipoproteins and analyzed by gas chromatography-mass spectrometry. For comparison, we also analyzed H. pylori phospholipids. Consistent with previous studies, we observed that the H. pylori phospholipids contain primarily C14:0 and C19:0 cyclopropane-containing fatty acids. In contrast, both the ester-linked and amide-linked fatty acids found in H. pylori lipoproteins were observed to be almost exclusively C16:0 and C18:0. A discrepancy between the acyl composition of membrane phospholipids and lipoproteins as reported here for H. pylori has been previously reported in other bacteria including Borrelia and Brucella. We discuss possible mechanisms.IMPORTANCEColonization of the stomach by Helicobacter pylori is an important risk factor in the development of gastric cancer, the third leading cause of cancer-related death worldwide. H. pylori persists in the stomach despite an immune response against the bacteria. Recognition of lipoproteins by TLR2 contributes to the innate immune response to H. pylori. However, the role of H. pylori lipoproteins in bacterial persistence is poorly understood. As the host response to lipoproteins depends on the acyl chain content, defining the acyl composition of H. pylori lipoproteins is an important step in characterizing how lipoproteins contribute to persistence.


Assuntos
Proteínas de Bactérias , Ácidos Graxos , Helicobacter pylori , Lipoproteínas , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Ácidos Graxos/metabolismo , Ácidos Graxos/química , Lipoproteínas/metabolismo , Lipoproteínas/química , Fosfolipídeos/metabolismo , Fosfolipídeos/química , Humanos , Infecções por Helicobacter/microbiologia , Imunidade Inata , Cromatografia Gasosa-Espectrometria de Massas
10.
Arch Biochem Biophys ; 754: 109956, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458481

RESUMO

Phospholipids are key biomolecules with important roles as components of membranes, lipoproteins and as signalling molecules. However, phospholipids are quite prone to oxidation. Upon oxidation they generate several types of oxidation products including long chain oxidation products, as hydroperoxyl and hydroxy derivatives, and highly reactive oxidation products, like small aldehydes and truncated oxidized phospholipids. The formation of protein adducts with small electrophilic aldehydes (like malondialdehyde) is now well studied, however, the aggregation of proteins with truncated oxidized phospholipids lacks research. This paper provides a short overview of the formation of protein adducts with truncated oxidized phospholipids as well as a gathering of the research on this topic. The literature found reports the synthesis, detection and fragmentation of this type of adducts, mainly focusing on truncated oxidized phospholipid' products from phosphatidylcholine class and few peptides and proteins, as human serum albumin and Apo B100, leaving unattended the screening in vivo and in disease correlation, thus lacking possible association with their biological role. These adducts are a consequence of oxidative modifications to important biomolecules and their involvement in the organism is still unclear, revealing the urgent need for more investigation in this area.


Assuntos
Lipoproteínas , Fosfolipídeos , Humanos , Fosfolipídeos/metabolismo , Oxirredução , Lipoproteínas/metabolismo , Peptídeos/metabolismo , Aldeídos/metabolismo
11.
Toxicology ; 504: 153764, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38428665

RESUMO

Hepatotoxicity poses a significant concern in drug design due to the potential liver damage that can be caused by new drugs. Among common manifestations of hepatotoxic damage is lipid accumulation in hepatic tissue, resulting in liver steatosis or phospholipidosis. Carboxylic derivatives are prone to interfere with fatty acid metabolism and cause lipid accumulation in hepatocytes. This study investigates the toxic behaviour of 24 structurally related carboxylic acids in hepatocytes, specifically their ability to cause accumulation of fatty acids and phospholipids. Using high-content screening (HCS) assays, we identified two distinct lipid accumulation patterns. Subsequently, we developed structure-activity relationship (SAR) and quantitative structure-activity relationship (QSAR) models to determine relevant molecular substructures and descriptors contributing to these adverse effects. Additionally, we calculated physicochemical properties associated with lipid accumulation in hepatocytes and examined their correlation with our chemical structure characteristics. To assess the applicability of our findings to a wide range of chemical compounds, we employed two external datasets to evaluate the distribution of our QSAR descriptors. Our study highlights the significance of subtle molecular structural variations in triggering hepatotoxicity, such as the presence of nitrogen or the specific arrangement of substitutions within the carbon chain. By employing our comprehensive approach, we pinpointed specific molecules and elucidated their mechanisms of toxicity, thus offering valuable insights to guide future toxicology investigations.


Assuntos
Ácidos Carboxílicos , Hepatócitos , Relação Quantitativa Estrutura-Atividade , Ácidos Carboxílicos/toxicidade , Ácidos Carboxílicos/química , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fosfolipídeos/metabolismo , Fosfolipídeos/química , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Células Hep G2
12.
J Clin Lab Anal ; 38(7): e25031, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38514901

RESUMO

BACKGROUND: Primary cilia are static microtubule-based structures protruding from the cell surface and present on most vertebrate cells. The appropriate localization of phospholipids is essential for cilia formation and stability. INPP5E is a cilia-localized inositol 5-phosphatase; its deletion alters the phosphoinositide composition in the ciliary membrane, disrupting ciliary function. METHODS: The EGFP-2xP4MSidM, PHPLCδ1-EGFP, and SMO-tRFP plasmids were constructed by the Gateway system to establish a stable RPE1 cell line. The INPP5E KO RPE1 cell line was constructed with the CRISPR/Cas9 system. The localization of INPP5E and the distribution of PI(4,5)P2 and PI4P were examined by immunofluorescence microscopy. The fluorescence intensity co-localized with cilia was quantified by ImageJ. RESULTS: In RPE1 cells, PI4P is localized at the ciliary membrane, whereas PI(4,5)P2 is localized at the base of cilia. Knocking down or knocking out INPP5E alters this distribution, resulting in the distribution of PI(4,5)P2 along the ciliary membrane and the disappearance of PI4P from the cilia. Meanwhile, PI(4,5)P2 is located in the ciliary membrane labeled by SMO-tRFP. CONCLUSIONS: INPP5E regulates the distribution of phosphoinositide on cilia. PI(4,5)P2 localizes at the ciliary membrane labeled with SMO-tRFP, indicating that ciliary pocket membrane contains PI(4,5)P2, and phosphoinositide composition in early membrane structures may differ from that in mature ciliary membrane.


Assuntos
Cílios , Monoéster Fosfórico Hidrolases , Cílios/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Monoéster Fosfórico Hidrolases/genética , Humanos , Linhagem Celular , Fosfatidilinositol 4,5-Difosfato/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/citologia , Fosfatos de Fosfatidilinositol/metabolismo , Sistemas CRISPR-Cas , Fosfolipídeos/metabolismo
13.
Cell ; 187(5): 1177-1190.e18, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38366593

RESUMO

Phospholipids containing a single polyunsaturated fatty acyl tail (PL-PUFA1s) are considered the driving force behind ferroptosis, whereas phospholipids with diacyl-PUFA tails (PL-PUFA2s) have been rarely characterized. Dietary lipids modulate ferroptosis, but the mechanisms governing lipid metabolism and ferroptosis sensitivity are not well understood. Our research revealed a significant accumulation of diacyl-PUFA phosphatidylcholines (PC-PUFA2s) following fatty acid or phospholipid treatments, correlating with cancer cell sensitivity to ferroptosis. Depletion of PC-PUFA2s occurred in aging and Huntington's disease brain tissue, linking it to ferroptosis. Notably, PC-PUFA2s interacted with the mitochondrial electron transport chain, generating reactive oxygen species (ROS) for initiating lipid peroxidation. Mitochondria-targeted antioxidants protected cells from PC-PUFA2-induced mitochondrial ROS (mtROS), lipid peroxidation, and cell death. These findings reveal a critical role for PC-PUFA2s in controlling mitochondria homeostasis and ferroptosis in various contexts and explain the ferroptosis-modulating mechanisms of free fatty acids. PC-PUFA2s may serve as diagnostic and therapeutic targets for modulating ferroptosis.


Assuntos
Gorduras na Dieta , Ferroptose , Fosfolipídeos , Ácidos Graxos , Fosfatidilcolinas , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Espécies Reativas de Oxigênio , Gorduras na Dieta/metabolismo
14.
ACS Chem Neurosci ; 15(5): 983-993, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38355427

RESUMO

Temporal lobe epilepsy (TLE) is one of the most common neurological disorders, often accompanied by hippocampal sclerosis. The molecular processes underlying this epileptogenesis are poorly understood. To examine the lipid profile, 39 fresh frozen sections of the human hippocampus obtained from epilepsy surgery for TLE (n = 14) and non-TLE (control group; n = 25) patients were subjected to desorption electrospray ionization mass spectrometry imaging in the negative ion mode. In contrast to our earlier report that showed striking downregulation of positively charged phospholipids (e.g., phosphatidylcholine and phosphatidylethanolamine, etc.) in the TLE hippocampus, this study finds complementary upregulation of negatively charged phospholipids, notably, phosphatidylserine and phosphatidylglycerol. This result may point to an active metabolic pool in the TLE hippocampus that produces these anionic phospholipids at the expense of the cationic phospholipids. This metabolic shift could be due to the dysregulation of the Kennedy and CDP-DG pathways responsible for biosynthesizing these lipids. Thus, this study further opens up opportunities to investigate the molecular hallmarks and potential therapeutic targets for TLE.


Assuntos
Epilepsia do Lobo Temporal , Fosfolipídeos , Humanos , Fosfolipídeos/metabolismo , Hipocampo/metabolismo , Epilepsia do Lobo Temporal/complicações , Epilepsia do Lobo Temporal/metabolismo , Epilepsia do Lobo Temporal/cirurgia , Espectrometria de Massas , Regulação para Cima , Imageamento por Ressonância Magnética/métodos
15.
Int J Mol Med ; 53(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38362962

RESUMO

Phospholipids (PLs) are principle constituents of biofilms, with their fatty acyl chain composition significantly impacting the biophysical properties of membranes, thereby influencing biological processes. Recent studies have elucidated that fatty acyl chains, under the enzymatic action of lyso­phosphatidyl­choline acyltransferases (LPCATs), expedite incorporation into the sn­2 site of phosphatidyl­choline (PC), profoundly affecting pathophysiology. Accumulating evidence suggests that alterations in LPCAT activity are implicated in various diseases, including non­alcoholic fatty liver disease (NAFLD), hepatitis C, atherosclerosis and cancer. Specifically, LPCAT3 is instrumental in maintaining systemic lipid homeostasis through its roles in hepatic lipogenesis, intestinal lipid absorption and lipoprotein secretion. The liver X receptor (LXR), pivotal in lipid homeostasis, modulates cholesterol, fatty acid (FA) and PL metabolism. LXR's capacity to modify PL composition in response to cellular sterol fluctuations is a vital mechanism for protecting biofilms against lipid stress. Concurrently, LXR activation enhances LPCAT3 expression on cell membranes and elevates polyunsaturated PL levels. This activation can ameliorate saturated free FA effects in vitro or endoplasmic reticulum stress in vivo due to lipid accumulation in hepatic cells. Pharmacological interventions targeting LXR, LPCAT and membrane PL components could offer novel therapeutic directions for NAFLD management. The present review primarily focused on recent advancements in understanding the LPCAT3 signaling pathway's role in lipid metabolism related to NAFLD, aiming to identify new treatment targets for the disease.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptores X do Fígado/metabolismo , Fígado/metabolismo , Metabolismo dos Lipídeos , Fosfolipídeos/metabolismo , Ácidos Graxos/metabolismo , Transdução de Sinais , Colina/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/farmacologia
16.
J Theor Biol ; 582: 111757, 2024 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-38336240

RESUMO

BACKGROUND: Factor X activation by the phospholipid-bound intrinsic tenase complex is a critical membrane-dependent reaction of blood coagulation. Its regulation mechanisms are unclear, and a number of questions regarding diffusional limitation, pathways of assembly and substrate delivery remain open. METHODS: We develop and analyze here a detailed mechanism-driven computer model of intrinsic tenase on phospholipid surfaces. Three-dimensional reaction-diffusion-advection and stochastic simulations were used where appropriate. RESULTS: Dynamics of the system was predominantly non-stationary under physiological conditions. In order to describe experimental data, we had to assume both membrane-dependent and solution-dependent delivery of the substrate. The former pathway dominated at low cofactor concentration, while the latter became important at low phospholipid concentration. Factor VIIIa-factor X complex formation was the major pathway of the complex assembly, and the model predicted high affinity for their lipid-dependent interaction. Although the model predicted formation of the diffusion-limited layer of substrate for some conditions, the effects of this limitation on the fXa production were small. Flow accelerated fXa production in a flow reactor model by bringing in fIXa and fVIIIa rather than fX. CONCLUSIONS: This analysis suggests a concept of intrinsic tenase that is non-stationary, employs several pathways of substrate delivery depending on the conditions, and is not particularly limited by diffusion of the substrate.


Assuntos
Fator X , Proteínas de Neoplasias , Fosfolipídeos , Fator X/metabolismo , Fosfolipídeos/metabolismo , Fator IXa/metabolismo , Cisteína Endopeptidases/metabolismo , Cinética
17.
Am J Physiol Gastrointest Liver Physiol ; 326(4): G411-G425, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38375587

RESUMO

Recently, the development of nonalcoholic steatohepatitis (NASH) in common strains of pigs has been achieved using a diet high in saturated fat, fructose, cholesterol, and cholate and deficient in choline and methionine. The aim of the present work was to characterize the hepatic and plasma lipidomic changes that accompany the progression of NASH and its reversal by switching pigs back to a chow diet. One month of this extreme steatotic diet was sufficient to induce porcine NASH. The lipidomic platform using liquid chromatography-mass spectrometry analyzed 467 lipid species. Seven hepatic phospholipids [PC(30:0), PC(32:0), PC(33:0), PC(33:1), PC(34:0), PC(34:3) and PC(36:2)] significantly discriminated the time of dietary exposure, and PC(30:0), PC(33:0), PC(33:1) and PC(34:0) showed rapid adaptation in the reversion period. Three transcripts (CS, MAT1A, and SPP1) showed significant changes associated with hepatic triglycerides and PC(33:0). Plasma lipidomics revealed that these species [FA 16:0, FA 18:0, LPC(17:1), PA(40:5), PC(37:1), TG(45:0), TG(47:2) and TG(51:0)] were able to discriminate the time of dietary exposure. Among them, FA 16:0, FA 18:0, LPC(17:1) and PA(40:5) changed the trend in the reversion phase. Plasma LDL-cholesterol and IL12P40 were good parameters to study the progression of NASH, but their capacity was surpassed by hepatic [PC(33:0), PC(33:1), and PC(34:0)] or plasma lipid [FA 16:0, FA 18:0, and LPC(17:1)] species. Taken together, these lipid species can be used as biomarkers of metabolic changes in the progression and regression of NASH in this model. The lipid changes suggest that the development of NASH also affects peripheral lipid metabolism.NEW & NOTEWORTHY A NASH stage was obtained in crossbred pigs. Hepatic [PC(33:0), PC(33:1) and PC(34:0)] or plasma [FA 16:0, FA 18:0 and LPC(17:1)] species were sensitive parameters to detect subtle changes in development and regression of nonalcoholic steatohepatitis (NASH). These findings may delineate the liquid biopsy to detect subtle changes in progression or in treatments. Furthermore, phospholipid changes according to the insult-inducing NASH may play an important role in accepting or rejecting fatty livers in transplantation.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Suínos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Lipidômica , Fígado/metabolismo , Fosfolipídeos/metabolismo , Colesterol/metabolismo , Modelos Animais de Doenças
18.
Nature ; 626(7998): 411-418, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38297130

RESUMO

Ferroptosis, a form of regulated cell death that is driven by iron-dependent phospholipid peroxidation, has been implicated in multiple diseases, including cancer1-3, degenerative disorders4 and organ ischaemia-reperfusion injury (IRI)5,6. Here, using genome-wide CRISPR-Cas9 screening, we identified that the enzymes involved in distal cholesterol biosynthesis have pivotal yet opposing roles in regulating ferroptosis through dictating the level of 7-dehydrocholesterol (7-DHC)-an intermediate metabolite of distal cholesterol biosynthesis that is synthesized by sterol C5-desaturase (SC5D) and metabolized by 7-DHC reductase (DHCR7) for cholesterol synthesis. We found that the pathway components, including MSMO1, CYP51A1, EBP and SC5D, function as potential suppressors of ferroptosis, whereas DHCR7 functions as a pro-ferroptotic gene. Mechanistically, 7-DHC dictates ferroptosis surveillance by using the conjugated diene to exert its anti-phospholipid autoxidation function and shields plasma and mitochondria membranes from phospholipid autoxidation. Importantly, blocking the biosynthesis of endogenous 7-DHC by pharmacological targeting of EBP induces ferroptosis and inhibits tumour growth, whereas increasing the 7-DHC level by inhibiting DHCR7 effectively promotes cancer metastasis and attenuates the progression of kidney IRI, supporting a critical function of this axis in vivo. In conclusion, our data reveal a role of 7-DHC as a natural anti-ferroptotic metabolite and suggest that pharmacological manipulation of 7-DHC levels is a promising therapeutic strategy for cancer and IRI.


Assuntos
Desidrocolesteróis , Ferroptose , Humanos , Membrana Celular/metabolismo , Colesterol/biossíntese , Colesterol/metabolismo , Sistemas CRISPR-Cas/genética , Desidrocolesteróis/metabolismo , Genoma Humano , Nefropatias/metabolismo , Membranas Mitocondriais/metabolismo , Metástase Neoplásica , Neoplasias/metabolismo , Neoplasias/patologia , Fosfolipídeos/metabolismo , Traumatismo por Reperfusão/metabolismo
19.
Biophys Chem ; 306: 107174, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38211368

RESUMO

The progressive aggregation of misfolded proteins is the underlying molecular cause of numerous pathologies including Parkinson's disease and injection and transthyretin amyloidosis. A growing body of evidence indicates that protein deposits detected in organs and tissues of patients diagnosed with such pathologies contain fragments of lipid membranes. In vitro experiments also showed that lipid membranes could strongly change the aggregation rate of amyloidogenic proteins, as well as alter the secondary structure and toxicity of oligomers and fibrils formed in their presence. In this review, the effect of large unilamellar vesicles (LUVs) composed of zwitterionic and anionic phospholipids on the aggregation rate of insulin, lysozyme, transthyretin (TTR) and α- synuclein (α-syn) will be discussed. The manuscript will also critically review the most recent findings on the lipid-induced changes in the secondary structure of protein oligomers and fibrils, as well as reveal the extent to which lipids could alter the toxicity of protein aggregates formed in their presence.


Assuntos
Amiloidose , Doença de Parkinson , Humanos , Agregados Proteicos , Fosfolipídeos/metabolismo , alfa-Sinucleína/química , Doença de Parkinson/metabolismo , Amiloidose/metabolismo , Proteínas Amiloidogênicas , Amiloide/química
20.
J Cell Biol ; 223(2)2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38270920

RESUMO

Phosphatidylserine levels and distribution are tightly controlled by dedicated enzymes at the ER and plasma membrane. Nakatsu and Kawasaki discuss new work by Aoki and colleagues (https://doi.org/10.1083/jcb.202212074), which reveals an acute reliance on phosphatidylserine synthesis in B cell lymphomas needed to prevent aberrant B cell receptor activation and ensuing apoptosis.


Assuntos
Linfoma de Células B , Fosfatidilserinas , Receptores de Antígenos de Linfócitos B , Humanos , Apoptose , Linfoma de Células B/metabolismo , Fosfatidilserinas/metabolismo , Fosfolipídeos/metabolismo , Estrutura Secundária de Proteína , Receptores de Antígenos de Linfócitos B/metabolismo
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