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1.
Annu Rev Cell Dev Biol ; 30: 169-206, 2014.
Article in English | MEDLINE | ID: mdl-25150009

ABSTRACT

The trans-Golgi network (TGN) is an important cargo sorting station within the cell where newly synthesized proteins are packaged into distinct transport carriers that are targeted to various destinations. To maintain the fidelity of protein transport, elaborate protein sorting machinery is employed to mediate sorting of specific cargo proteins into distinct transport carriers. Protein sorting requires assembly of the cytosolic sorting machinery onto the TGN membrane and capture of cargo proteins. We review the cytosolic and transmembrane sorting machinery that function at the TGN and describe molecular interactions and regulatory mechanisms that enable accurate protein sorting. In addition, we highlight the importance of TGN sorting in physiology and disease.


Subject(s)
Protein Transport/physiology , trans-Golgi Network/physiology , ADP-Ribosylation Factor 1/physiology , Adaptor Proteins, Vesicular Transport/physiology , Amino Acid Motifs , Animals , Carrier Proteins/physiology , Cell Polarity , Cytosol/physiology , Humans , Membrane Lipids/physiology , Membrane Transport Proteins/physiology , Models, Biological , Models, Molecular , Phospholipids/physiology , Protein Conformation , Protein Sorting Signals/physiology , Protein Transport/immunology , Structure-Activity Relationship , Transport Vesicles/physiology , Vesicular Transport Proteins/physiology , trans-Golgi Network/immunology
2.
PLoS Pathog ; 15(3): e1007385, 2019 03.
Article in English | MEDLINE | ID: mdl-30845186

ABSTRACT

The six-component maintenance of lipid asymmetry (Mla) system is responsible for retrograde transport of phospholipids, ensuring the barrier function of the Gram-negative cell envelope. Located within the outer membrane, MlaA (VacJ) acts as a channel to shuttle phospholipids from the outer leaflet. We identified Neisseria gonorrhoeae MlaA (ngo2121) during high-throughput proteomic mining for potential therapeutic targets against this medically important human pathogen. Our follow-up phenotypic microarrays revealed that lack of MlaA results in a complex sensitivity phenome. Herein we focused on MlaA function in cell envelope biogenesis and pathogenesis. We demonstrate the existence of two MlaA classes among 21 bacterial species, characterized by the presence or lack of a lipoprotein signal peptide. Purified truncated N. gonorrhoeae MlaA elicited antibodies that cross-reacted with a panel of different Neisseria. Little is known about MlaA expression; we provide the first evidence that MlaA levels increase in stationary phase and under anaerobiosis but decrease during iron starvation. Lack of MlaA resulted in higher cell counts during conditions mimicking different host niches; however, it also significantly decreased colony size. Antimicrobial peptides such as polymyxin B exacerbated the size difference while human defensin was detrimental to mutant viability. Consistent with the proposed role of MlaA in vesicle biogenesis, the ΔmlaA mutant released 1.7-fold more membrane vesicles. Comparative proteomics of cell envelopes and native membrane vesicles derived from ΔmlaA and wild type bacteria revealed enrichment of TadA-which recodes proteins through mRNA editing-as well as increased levels of adhesins and virulence factors. MlaA-deficient gonococci significantly outcompeted (up to 16-fold) wild-type bacteria in the murine lower genital tract, suggesting the growth advantage or increased expression of virulence factors afforded by inactivation of mlaA is advantageous in vivo. Based on these results, we propose N. gonorrhoeae restricts MlaA levels to modulate cell envelope homeostasis and fine-tune virulence.


Subject(s)
Bacterial Outer Membrane Proteins/metabolism , Neisseria gonorrhoeae/metabolism , Phospholipid Transfer Proteins/metabolism , ATP-Binding Cassette Transporters/metabolism , Bacteria , Bacterial Outer Membrane Proteins/physiology , Bacterial Proteins , Biological Transport , Cell Membrane , Cell Wall , Escherichia coli Proteins , Gonorrhea , Gram-Negative Bacteria/metabolism , Humans , Neisseria gonorrhoeae/physiology , Phospholipids/metabolism , Phospholipids/physiology , Phylogeny , Proteomics , Virulence , Virulence Factors
3.
Proc Natl Acad Sci U S A ; 115(32): E7587-E7594, 2018 08 07.
Article in English | MEDLINE | ID: mdl-30037998

ABSTRACT

The outer membrane (OM) of Gram-negative bacteria is a robust, impermeable, asymmetric bilayer of outer lipopolysaccharides (LPSs) and inner phospholipids containing selective pore proteins which confer on it the properties of a molecular sieve. This structure severely limits the variety of antibiotic molecules effective against Gram-negative pathogens and, as antibiotic resistance has increased, so has the need to solve the OM permeability problem. Polymyxin B (PmB) represents those rare antibiotics which act directly on the OM and which offer a distinct starting point for new antibiotic development. Here we investigate PmB's interactions with in vitro OM models and show how the physical state of the lipid matrix of the OM is a critical factor in regulating the interaction with the antimicrobial peptide. Using neutron reflectometry and infrared spectroscopy, we reveal the structural and chemical changes induced by PmB on OM models of increasing complexity. In particular, only a tightly packed model reproduced the temperature-controlled disruption of the asymmetric lipid bilayer by PmB observed in vivo. By measuring the order of outer-leaflet LPS and inner-leaflet phospholipids, we show that PmB insertion is dependent on the phase transition of LPS from the gel to the liquid crystalline state. The demonstration of a lipid phase transition in the physiological temperature range also supports the hypothesis that bacteria grown at different temperatures adapt their LPS structures to maintain a homeoviscous OM.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cell Membrane/metabolism , Drug Resistance, Bacterial , Gram-Negative Bacteria/physiology , Polymyxin B/pharmacology , Cell Membrane/chemistry , Cell Membrane Permeability/drug effects , Cell Membrane Permeability/physiology , Lipid Bilayers/chemistry , Lipopolysaccharides/chemistry , Lipopolysaccharides/physiology , Liquid Crystals/chemistry , Models, Chemical , Phase Transition , Phospholipids/chemistry , Phospholipids/physiology , Spectrum Analysis , Temperature
4.
Int J Mol Sci ; 22(5)2021 Mar 06.
Article in English | MEDLINE | ID: mdl-33800808

ABSTRACT

Plants are subject to different types of stress, which consequently affect their growth and development. They have developed mechanisms for recognizing and processing an extracellular signal. Second messengers are transient molecules that modulate the physiological responses in plant cells under stress conditions. In this sense, it has been shown in various plant models that membrane lipids are substrates for the generation of second lipid messengers such as phosphoinositide, phosphatidic acid, sphingolipids, and lysophospholipids. In recent years, research on lipid second messengers has been moving toward using genetic and molecular approaches to reveal the molecular setting in which these molecules act in response to osmotic stress. In this sense, these studies have established that second messengers can transiently recruit target proteins to the membrane and, therefore, affect protein conformation, activity, and gene expression. This review summarizes recent advances in responses related to the link between lipid second messengers and osmotic stress in plant cells.


Subject(s)
Lipids/physiology , Osmotic Pressure/physiology , Plants/metabolism , Second Messenger Systems/physiology , Calcium/metabolism , Glycolipids/physiology , Models, Biological , Phospholipids/physiology , Plant Proteins/metabolism , Salt Stress/physiology
5.
Int J Mol Sci ; 22(3)2021 Feb 02.
Article in English | MEDLINE | ID: mdl-33540788

ABSTRACT

Legionella are Gram-stain-negative rods associated with water environments: either natural or man-made systems. The inhalation of aerosols containing Legionella bacteria leads to the development of a severe pneumonia termed Legionnaires' disease. To establish an infection, these bacteria adapt to growth in the hostile environment of the host through the unusual structures of macromolecules that build the cell surface. The outer membrane of the cell envelope is a lipid bilayer with an asymmetric composition mostly of phospholipids in the inner leaflet and lipopolysaccharides (LPS) in the outer leaflet. The major membrane-forming phospholipid of Legionella spp. is phosphatidylcholine (PC)-a typical eukaryotic glycerophospholipid. PC synthesis in Legionella cells occurs via two independent pathways: the N-methylation (Pmt) pathway and the Pcs pathway. The utilisation of exogenous choline by Legionella spp. leads to changes in the composition of lipids and proteins, which influences the physicochemical properties of the cell surface. This phenotypic plasticity of the Legionella cell envelope determines the mode of interaction with the macrophages, which results in a decrease in the production of proinflammatory cytokines and modulates the interaction with antimicrobial peptides and proteins. The surface-exposed O-chain of Legionella pneumophila sg1 LPS consisting of a homopolymer of 5-acetamidino-7-acetamido-8-O-acetyl-3,5,7,9-tetradeoxy-l-glycero-d-galacto-non-2-ulosonic acid is probably the first component in contact with the host cell that anchors the bacteria in the host membrane. Unusual in terms of the structure and function of individual LPS regions, it makes an important contribution to the antigenicity and pathogenicity of Legionella bacteria.


Subject(s)
Host-Pathogen Interactions/physiology , Legionella/chemistry , Membrane Lipids/metabolism , Phospholipids/physiology , Antigens, Bacterial/immunology , Antigens, Bacterial/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Choline/metabolism , Fatty Acids/analysis , Genes, Bacterial , Genetic Variation , Humans , Legionella/genetics , Lipopolysaccharides/immunology , Lipopolysaccharides/metabolism , Phosphatidylcholines/metabolism , Species Specificity
6.
Int J Mol Sci ; 22(21)2021 Oct 20.
Article in English | MEDLINE | ID: mdl-34768742

ABSTRACT

The incidences of traumatic brain injuries (TBIs) are increasing globally because of expanding population and increased dependencies on motorized vehicles and machines. This has resulted in increased socio-economic burden on the healthcare system, as TBIs are often associated with mental and physical morbidities with lifelong dependencies, and have severely limited therapeutic options. There is an emerging need to identify the molecular mechanisms orchestrating these injuries to life-long neurodegenerative disease and a therapeutic strategy to counter them. This review highlights the dynamics and role of choline-containing phospholipids during TBIs and how they can be used to evaluate the severity of injuries and later targeted to mitigate neuro-degradation, based on clinical and preclinical studies. Choline-based phospholipids are involved in maintaining the structural integrity of the neuronal/glial cell membranes and are simultaneously the essential component of various biochemical pathways, such as cholinergic neuronal transmission in the brain. Choline or its metabolite levels increase during acute and chronic phases of TBI because of excitotoxicity, ischemia and oxidative stress; this can serve as useful biomarker to predict the severity and prognosis of TBIs. Moreover, the effect of choline-replenishing agents as a post-TBI management strategy has been reviewed in clinical and preclinical studies. Overall, this review determines the theranostic potential of choline phospholipids and provides new insights in the management of TBI.


Subject(s)
Brain Injuries, Traumatic/metabolism , Choline/metabolism , Phospholipids/metabolism , Brain/physiopathology , Brain Injuries, Traumatic/complications , Brain Injuries, Traumatic/physiopathology , Choline/physiology , Comorbidity/trends , Cytidine Diphosphate Choline/metabolism , Humans , Neurodegenerative Diseases , Neuroglia/physiology , Oxidative Stress/physiology , Phosphatidylcholines/metabolism , Phospholipids/physiology
7.
Am J Respir Cell Mol Biol ; 62(3): 354-363, 2020 03.
Article in English | MEDLINE | ID: mdl-31545652

ABSTRACT

Comparisons of infectivity among the clinically important nontuberculous mycobacteria (NTM) species have not been explored in great depth. Rapid-growing mycobacteria, including Mycobacterium abscessus and M. porcinum, can cause indolent but progressive lung disease. Slow-growing members of the M. avium complex are the most common group of NTM to cause lung disease, and molecular approaches can now distinguish between several distinct species of M. avium complex including M. intracellulare, M. avium, M. marseillense, and M. chimaera. Differential infectivity among these NTM species may, in part, account for differences in clinical outcomes and response to treatment; thus, knowing the relative infectivity of particular isolates could increase prognostication accuracy and enhance personalized treatment. Using human macrophages, we investigated the infectivity and virulence of nine NTM species, as well as multiple isolates of the same species. We also assessed their capacity to evade killing by the antibacterial peptide cathelicidin (LL-37). We discovered that the ability of different NTM species to infect macrophages varied among the species and among isolates of the same species. Our biochemical assays implicate modified phospholipids, which may include a phosphatidylinositol or cardiolipin backbone, as candidate antagonists of LL-37 antibacterial activity. The high variation in infectivity and virulence of NTM strains suggests that more detailed microbiological and biochemical characterizations are necessary to increase our knowledge of NTM pathogenesis.


Subject(s)
Antimicrobial Cationic Peptides/antagonists & inhibitors , Immune Evasion/physiology , Membrane Lipids/physiology , Nontuberculous Mycobacteria/pathogenicity , Phospholipids/physiology , Antimicrobial Cationic Peptides/metabolism , Antimicrobial Cationic Peptides/pharmacology , Cell Membrane/immunology , Chromatography, Thin Layer , Escherichia coli/drug effects , Humans , Macrophages/microbiology , Macrophages, Alveolar/microbiology , Membrane Lipids/isolation & purification , Nontuberculous Mycobacteria/drug effects , Nontuberculous Mycobacteria/physiology , Phospholipids/isolation & purification , Phylogeny , Species Specificity , THP-1 Cells , Virulence , Cathelicidins
8.
J Biol Chem ; 294(12): 4282-4289, 2019 03 22.
Article in English | MEDLINE | ID: mdl-30733339

ABSTRACT

Toll-like receptors (TLRs) coupled to intracellular signaling cascades function as central elements of innate immunity that control transcription of numerous pro-inflammatory genes. Two minor anionic phospholipids present in the pulmonary surfactant complex, palmitoyl-oleoyl-phosphatidylglycerol (POPG) and phosphatidylinositol (PI), antagonize the cognate ligand activation of TLRs 2 and 4. The lipids block recognition of activating ligands by the TLRs, either directly or via the TLR4 coreceptors CD14 and MD2. Antagonism of TLR activation results in inhibition of the initiating step of the pro-inflammatory signaling pathways. Evidence for this mechanism of action comes from direct binding studies between CD14 and MD2 with POPG and PI. Additional evidence for this mechanism of antagonism also comes from monitoring the reduction of protein phosphorylation events that characterize the intracellular signaling by activated TLRs. The pathogenesis of respiratory syncytial virus (RSV) and influenza A virus (IAV) have been linked to TLR4 activation, and we examined the action of POPG and PI as potential antagonists of the pathology of these viruses. Surprisingly, POPG and PI dramatically curtail infection, in addition to inhibiting inflammatory sequelae associated with RSV and IAV infections. The mechanism of action by the lipids is disruption of virus particle binding to host cell plasma membrane receptors, required for viral uptake. The antagonism of activation of TLRs and virus binding to the alveolar epithelium by resident constituents of the pulmonary surfactant system suggests that POPG and PI function in homeostasis, to prevent inflammatory processes that result in reductions in gas exchange within the alveolar compartment.


Subject(s)
Immunity, Innate/physiology , Influenza A virus/isolation & purification , Phospholipids/physiology , Respiratory Syncytial Viruses/isolation & purification , Respiratory Tract Infections/immunology , Respiratory Tract Infections/virology , Animals , Humans , Phospholipids/metabolism , Pulmonary Surfactants/metabolism
9.
J Neurochem ; 153(3): 300-333, 2020 05.
Article in English | MEDLINE | ID: mdl-31745996

ABSTRACT

Despite the human brain being made of nearly 60% fat, the vast majority of studies on the mechanisms of neuronal communication which underpin cognition, memory and learning, primarily focus on proteins and/or (epi)genetic mechanisms. Phospholipids are the main component of all cellular membranes and function as substrates for numerous phospholipid-modifying enzymes, including phospholipases, which release free fatty acids (FFAs) and other lipid metabolites that can alter the intrinsic properties of the membranes, recruit and activate critical proteins, and act as lipid signalling molecules. Here, we will review brain specific phospholipases, their roles in membrane remodelling, neuronal function, learning and memory, as well as their disease implications. In particular, we will highlight key roles of unsaturated FFAs, particularly arachidonic acid, in neurotransmitter release, neuroinflammation and memory. In light of recent findings, we will also discuss the emerging role of phospholipase A1 and the creation of saturated FFAs in the brain.


Subject(s)
Memory/physiology , Neurons/enzymology , Phospholipases/physiology , Animals , Brain/enzymology , Humans , Learning/physiology , Phospholipids/physiology
10.
Microb Cell Fact ; 19(1): 176, 2020 Sep 04.
Article in English | MEDLINE | ID: mdl-32887610

ABSTRACT

Membrane remodeling and phospholipid biosynthesis are normally tightly regulated to maintain the shape and function of cells. Indeed, different physiological mechanisms ensure a precise coordination between de novo phospholipid biosynthesis and modulation of membrane morphology. Interestingly, the overproduction of certain membrane proteins hijack these regulation networks, leading to the formation of impressive intracellular membrane structures in both prokaryotic and eukaryotic cells. The proteins triggering an abnormal accumulation of membrane structures inside the cells (or membrane proliferation) share two major common features: (1) they promote the formation of highly curved membrane domains and (2) they lead to an enrichment in anionic, cone-shaped phospholipids (cardiolipin or phosphatidic acid) in the newly formed membranes. Taking into account the available examples of membrane proliferation upon protein overproduction, together with the latest biochemical, biophysical and structural data, we explore the relationship between protein synthesis and membrane biogenesis. We propose a mechanism for the formation of these non-physiological intracellular membranes that shares similarities with natural inner membrane structures found in α-proteobacteria, mitochondria and some viruses-infected cells, pointing towards a conserved feature through evolution. We hope that the information discussed in this review will give a better grasp of the biophysical mechanisms behind physiological and induced intracellular membrane proliferation, and inspire new applications, either for academia (high-yield membrane protein production and nanovesicle production) or industry (biofuel production and vaccine preparation).


Subject(s)
Cell Membrane/physiology , Cell Surface Extensions/metabolism , Membrane Proteins/physiology , Organelles/physiology , Phospholipids/physiology , Cell Membrane/ultrastructure , Cell Surface Extensions/ultrastructure , Organelles/ultrastructure , Protein Conformation
11.
Plant Cell Physiol ; 60(7): 1556-1566, 2019 Jul 01.
Article in English | MEDLINE | ID: mdl-31073607

ABSTRACT

Oil crop Brassica napus is subjected to environmental stresses such as drought, cold and salt. Phospholipase Ds (PLDs) have vital roles in regulation of plant growth, development and stress tolerance. In this study, 32 BnaPLD genes were identified and classified into six subgroups depending on the conserved protein structures. High similarity in gene and protein structures exists between BnaPLDs and AtPLDs. Gene expression analysis showed that BnaPLDα1s and BnaPLDδs had higher expression than other PLDs. BnaPLDα1 and BnaPLDδ were significantly induced by abiotic stresses including dehydration, NaCl, abscisic acid (ABA) and 4�C. Lipidomic analysis showed that the content of main membrane phospholipids decreased gradually under stresses, except phosphatidylglycerol increased under the treatment of ABA and phosphatidylethanolamine increased under 4�C. Correspondingly, their product of phosphatidic acid increased often with a transient peak at 8 h. The plant height of mutants of PLDα1 was significantly reduced. Agronomic traits such as yield, seed number, silique number and branches were significantly impaired in PLDα1 mutants. These results indicate that there is a large family of PLD genes in B. napus, especially BnaPLDα1s and BnaPLDδs may play important roles in membrane lipids remodeling and maintaining of the growth and stress tolerance of B. napus.


Subject(s)
Brassica napus/genetics , Genes, Plant/genetics , Phospholipase D/genetics , Phospholipids/metabolism , Brassica napus/enzymology , Brassica napus/metabolism , Gene Expression Regulation, Plant , Genes, Plant/physiology , Genome-Wide Association Study , Lipid Metabolism , Lipids/physiology , Phospholipase D/metabolism , Phospholipids/physiology , Phylogeny , Plant Leaves/metabolism , Stress, Physiological , Transcriptome
12.
Crit Rev Food Sci Nutr ; 59(2): 253-275, 2019.
Article in English | MEDLINE | ID: mdl-28820277

ABSTRACT

During the last years, phospholipids (PLs) have attracted great attention because of their crucial roles in providing nutritional values, technological and medical applications. There are considerable proofs that PLs have unique nutritional benefits on human health, such as reducing cholesterol absorption, improving liver functions, and decreasing the risk of cardiovascular diseases. PLs are the main structural lipid components of cell and organelle membranes in all living organisms, and therefore, they occur in all organisms and the derived food products. PLs are distinguished by the presence of a hydrophilic head and a hydrophobic tail, consequently they possess amphiphilic features. Due to their unique characteristics, the extraction, separation, and identification of PLs are critical issues to be concerned. This review is focused on the content of PLs classes in several sources (including milk, vegetable oils, egg yolk, and mitochondria). As well, it highlights PLs biosynthesis, and the methodologies applied for PLs extraction and separation, such as solvent extraction and solid-phase extraction. In addition, the determination and quantification of PLs classes by using thin layer chromatography, high-performance liquid chromatography coupled with different detectors, and nuclear magnetic resonance spectroscopy techniques.


Subject(s)
Health Promotion , Phospholipids/physiology , Animals , Chromatography/methods , Dairy Products/analysis , Diet , Egg Yolk/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Magnetic Resonance Spectroscopy/methods , Milk/chemistry , Mitochondria/chemistry , Nutritive Value , Phospholipids/analysis , Phospholipids/biosynthesis , Plant Oils/chemistry , Surface-Active Agents
13.
Khirurgiia (Mosk) ; (5): 25-30, 2019.
Article in Russian | MEDLINE | ID: mdl-31169815

ABSTRACT

AIM: To justify the concept of systemic membrane-destabilizing distress syndrome in surgery via analysis of phospholipid bilayer of cell membranes of various organs in urgent surgical abdominal diseases. MATERIAL AND METHODS: Experimental research on dogs (n=90) included modeling of peritonitis, pancreatitis, intestinal obstruction, obstructive jaundice, and post-hemorrhagic anemia. Clinical and laboratory studies were performed in patients (n=119) with acute peritonitis, severe pancreatitis, intestinal obstruction, post-hemorrhagic anemia, acute cholecystitis, gastrointestinal bleeding, benign mechanical jaundice. Lipid profile in tissues and blood cells was determined by extraction, fractionation and densitometry. Moreover, we assessed intensity of lipid peroxidation and phospholipase activity, endogenous intoxication, functional state of organs and blood cells. RESULTS: It was revealed that all above-mentioned acute abdominal diseases are followed by significant changes of lipid bilayer and dysfunction of tissues in target organs, blood cells and other organs (liver, kidney, colon and small intestine, heart, lungs, spleen, brain). Changes of phospholipid bilayer are correlated with severity and course of the disease. These data were used to determine a new complex in surgery - systemic membrane-destabilizing distress syndrome. Its concept, pathogenesis, and diagnosis are presented. It was analyzed its role in development and progression of dysregulation pathology and thanatogenesis. Evidence of its importance in the pathogenesis of surgical aggression was obtained.


Subject(s)
Anemia/physiopathology , Cell Membrane/physiology , Digestive System Diseases/physiopathology , Hemorrhage/physiopathology , Jaundice, Obstructive/physiopathology , Stress, Physiological/physiology , Anemia/complications , Animals , Digestive System Diseases/complications , Disease Models, Animal , Dogs , Hemorrhage/complications , Humans , Jaundice, Obstructive/complications , Membrane Lipids/physiology , Phospholipids/physiology , Syndrome
14.
Curr Genet ; 64(5): 1071-1087, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29536156

ABSTRACT

Cell size and morphology are key adaptive features that influence almost all aspects of cellular physiology such as cell cycle and lipid metabolism. Here we report the role of a transcription factor Suppressor Phenotype of Ty elements insertion 10 (SPT10) of Saccharomyces cerevisiae in regulating cell cycle, cell size and lipid metabolism in concert, in addition to its defined role of histone gene expression. Morphological and biochemical analyses of spt10Δ strain show an abnormal cell size, cell cycle and lipid levels. The expression of Spt10p in spt10Δ strain helps the cell revert to typical wild-type phenotypes. SPT10 controls lipid metabolism by negatively regulating the expression of lipid biosynthetic genes, and positively regulating the expression of the lipid hydrolyzing genes. Spt10p helps in maintaining the cell size by regulating the amount of carbon flux into the phospholipid constituents of the cell membranes. On the contrary, storage lipids have no role in regulating the cell size. An exogenous supply of phosphatidic acid increases the cell size, proving the positive impact of the phospholipids on cell size modulation. SPT10 affects cell cycle, cell size and lipid metabolism by an orchestrated transcriptional regulation of the corresponding genes.


Subject(s)
Histone Acetyltransferases/metabolism , Lipid Metabolism , Phospholipids/physiology , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/metabolism , Transcription Factors/metabolism , Carbon/metabolism , Cell Cycle , DNA, Fungal/metabolism , Electrophoretic Mobility Shift Assay , Gene Expression Regulation, Fungal , Genes, Fungal , Genetic Complementation Test , Lipid Metabolism/genetics , Lipids/biosynthesis , Phosphatidic Acids/pharmacology , Protein Binding , Saccharomyces cerevisiae/genetics , Transcription, Genetic , Up-Regulation
15.
Biochim Biophys Acta Biomembr ; 1859(9 Pt B): 1704-1724, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28432031

ABSTRACT

Membrane Lipid Replacement is the use of functional, oral supplements containing mixtures of cell membrane glycerolphospholipids, plus fructooligosaccharides (for protection against oxidative, bile acid and enzymatic damage) and antioxidants, in order to safely replace damaged, oxidized, membrane phospholipids and restore membrane, organelle, cellular and organ function. Defects in cellular and intracellular membranes are characteristic of all chronic medical conditions, including cancer, and normal processes, such as aging. Once the replacement glycerolphospholipids have been ingested, dispersed, complexed and transported, while being protected by fructooligosaccharides and several natural mechanisms, they can be inserted into cell membranes, lipoproteins, lipid globules, lipid droplets, liposomes and other carriers. They are conveyed by the lymphatics and blood circulation to cellular sites where they are endocytosed or incorporated into or transported by cell membranes. Inside cells the glycerolphospholipids can be transferred to various intracellular membranes by lipid globules, liposomes, membrane-membrane contact or by lipid carrier transfer. Eventually they arrive at their membrane destinations due to 'bulk flow' principles, and there they can stimulate the natural removal and replacement of damaged membrane lipids while undergoing further enzymatic alterations. Clinical trials have shown the benefits of Membrane Lipid Replacement in restoring mitochondrial function and reducing fatigue in aged subjects and chronically ill patients. Recently Membrane Lipid Replacement has been used to reduce pain and other symptoms as well as removing hydrophobic chemical contaminants, suggesting that there are additional new uses for this safe, natural medicine supplement. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.


Subject(s)
Aging/drug effects , Cell Membrane/chemistry , Glycerophospholipids/therapeutic use , Membrane Lipids/therapeutic use , Neoplasms/drug therapy , Oligosaccharides/therapeutic use , Organelles/chemistry , Phospholipids/physiology , Administration, Oral , Animals , Chronic Disease , Energy Metabolism/drug effects , Humans , Oligosaccharides/pharmacology , Oxidative Stress
16.
Eur J Immunol ; 46(8): 1818-25, 2016 08.
Article in English | MEDLINE | ID: mdl-27312261

ABSTRACT

During inflammation or under conditions of oxidative stress, the polyunsaturated fatty acid side chains of phospholipids in cellular membranes or lipoproteins can be oxidatively modified. This process generates a complex mixture of structurally diverse oxidized phospholipid (OxPL) species, each of which may exert distinct biological effects. The presence of OxPLs has been documented in acute and chronic microbial infections, metabolic disorders, and degenerative diseases. It is now well recognized that OxPLs actively influence biological processes and contribute to the induction and resolution of inflammation. While many pro- and anti-inflammatory effects have been documented for bulk OxPL preparations, we are only beginning to understand the exact molecular mechanisms and signaling events that mediate the individual proinflammatory or anti-inflammatory bioactivities of discrete isolated OxPL species. Here, we review the current knowledge on the regulation of inflammation by OxPLs and summarize recent studies that establish cyclopentenone-containing OxPLs as a category of potent anti-inflammatory lipid mediators.


Subject(s)
Cyclopentanes/chemistry , Inflammation/immunology , NF-E2-Related Factor 2/metabolism , Phospholipids/physiology , Animals , Humans , Isoprostanes/physiology , Mice , Signal Transduction
17.
J Neurosci ; 35(6): 2731-46, 2015 Feb 11.
Article in English | MEDLINE | ID: mdl-25673862

ABSTRACT

Drosophila phototransduction is mediated via a G-protein-coupled PLC cascade. Recent evidence, including the demonstration that light evokes rapid contractions of the photoreceptors, suggested that the light-sensitive channels (TRP and TRPL) may be mechanically gated, together with protons released by PLC-mediated PIP2 hydrolysis. If mechanical gating is involved we predicted that the response to light should be influenced by altering the physical properties of the membrane. To achieve this, we used diet to manipulate the degree of saturation of membrane phospholipids. In flies reared on a yeast diet, lacking polyunsaturated fatty acids (PUFAs), mass spectrometry showed that the proportion of polyunsaturated phospholipids was sevenfold reduced (from 38 to ∼5%) but rescued by adding a single species of PUFA (linolenic or linoleic acid) to the diet. Photoreceptors from yeast-reared flies showed a 2- to 3-fold increase in latency and time to peak of the light response, without affecting quantum bump waveform. In the absence of Ca(2+) influx or in trp mutants expressing only TRPL channels, sensitivity to light was reduced up to ∼10-fold by the yeast diet, and essentially abolished in hypomorphic G-protein mutants (Gαq). PLC activity appeared little affected by the yeast diet; however, light-induced contractions measured by atomic force microscopy or the activation of ectopic mechanosensitive gramicidin channels were also slowed ∼2-fold. The results are consistent with mechanosensitive gating and provide a striking example of how dietary fatty acids can profoundly influence sensory performance in a classical G-protein-coupled signaling cascade.


Subject(s)
Cell Membrane/physiology , Drosophila melanogaster/physiology , Light Signal Transduction/physiology , Phospholipids/physiology , Animals , Cell Membrane/metabolism , Diet , Ion Channel Gating/physiology , Light , Lipid Metabolism/physiology , Phospholipids/metabolism , Receptors, G-Protein-Coupled/physiology , Rhodopsin/metabolism , Signal-To-Noise Ratio , Sodium-Calcium Exchanger/metabolism , Type C Phospholipases/metabolism
18.
Appl Microbiol Biotechnol ; 100(10): 4255-67, 2016 May.
Article in English | MEDLINE | ID: mdl-27026177

ABSTRACT

In addition to playing a central role as a permeability barrier for controlling the diffusion of molecules and ions in and out of bacterial cells, phospholipid (PL) membranes regulate the spatial and temporal position and function of membrane proteins that play an essential role in a variety of cellular functions. Based on the very large number of membrane-associated proteins encoded in genomes, an understanding of the role of PLs may be central to understanding bacterial cell biology. This area of microbiology has received considerable attention over the past two decades, and the local enrichment of anionic PLs has emerged as a candidate mechanism for biomolecular organization in bacterial cells. In this review, we summarize the current understanding of anionic PLs in bacteria, including their biosynthesis, subcellular localization, and physiological relevance, discuss evidence and mechanisms for enriching anionic PLs in membranes, and conclude with an assessment of future directions for this area of bacterial biochemistry, biophysics, and cell biology.


Subject(s)
Bacteria/chemistry , Membrane Proteins/physiology , Phospholipids/physiology , Anions/chemistry , Bacterial Proteins/physiology , Cell Membrane/physiology
19.
Postepy Hig Med Dosw (Online) ; 70(0): 1343-1361, 2016 Dec 31.
Article in English | MEDLINE | ID: mdl-28100844

ABSTRACT

The results of numerous epidemiological studies indicate that phospholipids play an important role in the prevention of chronic diseases faced by contemporary society. Firstly, these compounds are responsible for the proper functioning of cell membranes, by ensuring liquidity and permeability, which is pivotal for normal activity of membrane proteins, including receptors. These mechanisms are at the core of prevention of cancer, autoimmune or neurological disorders. Secondly, structure and properties of phospholipids cause that they are highly available source of biologically active fatty acids. Thirdly, also products of endogenous hydrolysis of phospholipids exhibit biological activity. These include lysophospholipids formed as a result of disconnecting free fatty acid from glycerophospholipids in the reaction catalyzed by phospholipase A, phosphatidic acid and hydrophilic subunits released by the activity of phospholipase D. The bioactive products of hydrolysis also include ceramides liberated from phosphosphingolipids after removal of a hydrophilic unit catalyzed by sphingomyelinase. Phospholipids are supplied to the human body with food. A high content of phospholipids is characteristic for egg yolk, liver, pork and poultry, as well as some soy products. Particularly beneficial are phospholipids derived from seafood because they are a rich source of essential fatty acids of the n-3 family.


Subject(s)
Autoimmune Diseases/prevention & control , Food , Neoplasms/prevention & control , Nervous System Diseases/prevention & control , Phospholipids/physiology , Ceramides/metabolism , Ceramides/physiology , Fatty Acids/metabolism , Fatty Acids/physiology , Female , Humans , Hydrolysis , Lysophospholipids/metabolism , Lysophospholipids/physiology , Male , Phospholipids/metabolism
20.
Proteomics ; 15(4): 824-35, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25404199

ABSTRACT

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) such as gefitinib are one of gold standard treatment options for nonsmall-cell lung cancer (NSCLC) patients, which eventually fail due to the acquired resistance and relapse because of the development of secondary activating mutations such as T790M in EGFR. Predicting chemo-responsiveness of cancer patients provides a major challenge in chemotherapy. The goal of the present study is to determine whether phospholipid signatures of tumor extracellular vesicles (EV) are associated with gefitinib-resistance of NSCLC. A sophisticated MS-based shotgun lipidomic assays were performed for in-depth analysis of the lipidomes of gefitinib-resistant (PC9R) and responsive (PC9) NSCLC cells and their shed EV from these cell lines (PC9EV or PC9REV). Lipid MALDI-MS analysis showed that EV phospholipid composition was significantly distinct in PC9R, compared to PC9 cells. Following statistical analyses has identified 35 (20 positive and 15 negative ion mode) differentially regulated lipids, which are significantly over- or underexpressed in PC9R EV, compared to PC9 EV (p value < 0.01, fold change > 1.5). Our phospholipid signatures suggest that EV associates with drug sensitivity, which is worthy of additional investigation to assess chemoresistance in patients with NSCLC treated with anti-EGFR TKIs.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung , Cell Extracts , Drug Resistance, Neoplasm , Extracellular Space , Phospholipids , Quinazolines/pharmacology , Cell Extracts/chemistry , Cell Extracts/pharmacology , Cell Line, Tumor , Cytoplasmic Vesicles/chemistry , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/physiology , Extracellular Space/drug effects , Extracellular Space/physiology , Gefitinib , Humans , Phospholipids/pharmacology , Phospholipids/physiology
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