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1.
J Agric Food Chem ; 67(41): 11436-11443, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31553599

RESUMO

Phospholipids and phytic acid are important phosphorus (P)-containing compounds in rice grains. Phytic acid is considered as a major antinutrient, because the negatively charged phytic acid chelates cations, including essential micronutrients, and decreases their bioavailability to human beings and monogastric animals. To gain an insight into the interplay of these two kinds of phosphorus-containing metabolites, we used the CRISPR/Cas9 system to generate mutants of a phospholipase D gene (OsPLDα1) and analyzed the mutational effect on metabolites, including phytic acid in rice grains. Metabolic profiling of two ospldα1 mutants revealed depletion in the phosphatidic acid production and lower accumulation of cytidine diphosphate diacylglycerol and phosphatidylinositol. The mutants also showed significantly reduced phytic acid content as compared to their wild-type parent, and the expression of the key genes involved in the phytic acid biosynthesis was altered in the mutants. These results demonstrate that OsPLDα1 not only plays an important role in phospholipid metabolism but also is involved in phytic acid biosynthesis, most probably through the lipid-dependent pathway, and thus revealed a potential new route to regulate phytic acid biosynthesis in rice.


Assuntos
Oryza/genética , Fosfolipase D/genética , Ácido Fítico/biossíntese , Proteínas de Plantas/genética , Análise Mutacional de DNA , Regulação da Expressão Gênica de Plantas , Oryza/enzimologia , Oryza/metabolismo , Fosfolipase D/metabolismo , Fosfolipídeos/metabolismo , Proteínas de Plantas/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/metabolismo
2.
J Agric Food Chem ; 67(34): 9683-9693, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31379160

RESUMO

Schizochytrium sp. A-2 is a heterotrophic marine fungus used for the commercial production of docosahexaenoic acid (DHA). However, the pattern of the distribution of DHA and how DHA is channeled into phospholipid (PL) and triacylglycerol (TAG) are unknown. In this study, we systematically analyzed the distribution of DHA in TAG and PL during the growth of the cell. The migration of DHA from PL to TAG was presumed during the fermentation cycle. DHA and docosapentaenoic acid were accumulated in both TAG and phosphatidylcholine (PC), whereas eicosapentaenoic acid was mainly deposited in PC. RNA seq revealed that malic enzyme may provide lipogenic NADPH. In addition, long-chain acyl-CoA synthase and acyl-CoA:lysophosphatidylcholine acyltransferase may participate in the accumulation of DHA in PL. No phosphatidylcholine:diacylglycerol cholinephosphotransferase was identified from the genome sequence. In contrast, phospholipid:diacylglycerol acyltransferase-mediated acyl-CoA-independent TAG synthesis pathway and phospholipase C may contribute to the channeling of DHA from PC to TAG.


Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Estramenópilas/genética , Estramenópilas/metabolismo , Transcriptoma , 1-Acilglicerofosfocolina O-Aciltransferase/genética , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , Acil Coenzima A/genética , Acil Coenzima A/metabolismo , Transporte Biológico , Fosfolipídeos/metabolismo , Estramenópilas/química , Triglicerídeos/metabolismo , Fosfolipases Tipo C/genética , Fosfolipases Tipo C/metabolismo
3.
J Agric Food Chem ; 67(35): 9958-9966, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31419123

RESUMO

Chilling injury (CI) is a physiological disorder induced by cold, which heavily limit crop production and postharvest preservation worldwide. Methyl jasmonate (MeJA) can alleviate CI in various fruit species, including peach; however, the underlying molecular mechanism is poorly understood. Here, changes in contents of phenolics, lipids, and jasmonic acid (JA) and gene expressions are compared between MeJA and control fruit. Exogenous MeJA inhibited expressions of PpPAL1, PpPPO1, and PpPOD1/2 but did not affect the phenolic content. Furthermore, MeJA fruit showed lower relative electrolyte leakage, indicating less membrane damage. Meanwhile, the enrichment of linoleic acid in the potential lipid biomarkers, especially phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol, coincided with lower expressions of PpFAD8.1 but higher PpLOX3.1 and JA content. In the JA signaling pathway, MeJA significantly upregulated expressions of PpMYC2.2 and PpCBF3 but downregulated PpMYC2.1. In conclusion, adjustments of fatty acids in phospholipids contribute to MeJA-induced alleviation of CI in peach fruit via induction of the JA-mediated C-repeat-binding factor pathway.


Assuntos
Acetatos/farmacologia , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Frutas/efeitos dos fármacos , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Fosfolipídeos/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Prunus persica/metabolismo , Temperatura Baixa , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/efeitos dos fármacos , Prunus persica/genética , Prunus persica/crescimento & desenvolvimento
4.
Artigo em Inglês | MEDLINE | ID: mdl-31176865

RESUMO

Antarctic notothenioid fishes are highly stenothermal, yet their tolerance for warming is species-dependent. Because a body of literature points to the loss of cardiac function as underlying thermal limits in ectothermic animals, we investigated potential relationships among properties of ventricular mitochondrial membranes in notothenioids with known differences in both cardiac mitochondrial metabolism and organismal thermal tolerance. Fluidity of mitochondrial membranes was quantified by fluorescence depolarization for the white-blooded Chaenocephalus aceratus and the red-blooded Notothenia coriiceps. In these same membranes, lipid compositions and products of lipid peroxidation, the latter of which can disrupt membrane order, were analyzed in both species and in a second icefish, Pseudochaenichthys georgianus. Mitochondrial membranes from C. aceratus were significantly more fluid than those of the more thermotolerant species N. coriiceps (P < .0001). Consistent with this, ratios of total phosphatidylethanolamine (PE) to total phosphatidylcholine (PC) were lower in membranes from both species of icefishes, compared to those of N. coriiceps (P < .05). However, membranes of N. coriiceps displayed a greater unsaturation index (P < .0001). No differences among species were found in membrane products of lipid peroxidation. With rising temperatures, greater contents of PC in mitochondrial membranes from ventricles of icefishes are likely to promote membrane hyperfluidization at a lower temperature than for cardiac mitochondrial membranes from the red-blooded notothenioid. We propose that physical and chemical properties of the mitochondrial membranes may contribute to some of the observed differences in thermal sensitivity of physiological function among these species.


Assuntos
Lipídeos de Membrana/metabolismo , Miocárdio/metabolismo , Perciformes/metabolismo , Fosfolipídeos/metabolismo , Animais , Regiões Antárticas , Aquecimento Global , Peroxidação de Lipídeos , Fluidez de Membrana , Lipídeos de Membrana/química , Membranas Mitocondriais/metabolismo , Fosfolipídeos/química , Especificidade da Espécie , Termotolerância
5.
Gastroenterology ; 157(3): 807-822, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31194980

RESUMO

BACKGROUND & AIMS: In one-third of hepatocellular carcinomas (HCCs), cancer cells have mutations that activate ß-catenin pathway. These cells have alterations in glutamine, bile, and lipid metabolism. We investigated whether positron emission tomography (PET) imaging allows identification of altered metabolic pathways that might be targeted therapeutically. METHODS: We studied mice with activation of ß-catenin in liver (Apcko-liv mice) and male C57Bl/6 mice given injections of diethylnitrosamine, which each develop HCCs. Mice were fed a conventional or a methionine- and choline-deficient diet or a choline-deficient (CD) diet. Choline uptake and metabolism in HCCs were analyzed by micro-PET imaging of mice; livers were collected and analyzed by histologic, metabolomic, messenger RNA quantification, and RNA-sequencing analyses. Fifty-two patients with HCC underwent PET imaging with 18F-fluorodeoxyglucose, followed by 18F-fluorocholine tracer metabolites. Human HCC specimens were analyzed by immunohistochemistry, quantitative polymerase chain reaction, and DNA sequencing. We used hepatocytes and mouse tumor explants for studies of incorporation of radiolabeled choline into phospholipids and its contribution to DNA methylation. We analyzed HCC progression in mice fed a CD diet. RESULTS: Livers and tumors from Apcko-liv mice had increased uptake of dietary choline, which contributes to phospholipid formation and DNA methylation in hepatocytes. In patients and in mice, HCCs with activated ß-catenin were positive in 18F-fluorocholine PET, but not 18F-fluorodeoxyglucose PET, and they overexpressed the choline transporter organic cation transporter 3. The HCC cells from Apcko-liv mice incorporated radiolabeled methyl groups of choline into phospholipids and DNA. In Apcko-liv mice, the methionine- and choline-deficient diet reduced proliferation and DNA hypermethylation of hepatocytes and HCC cells, and the CD diet reduced long-term progression of tumors. CONCLUSIONS: In mice and humans, HCCs with mutations that activate ß-catenin are characterized by increased uptake of a fluorocholine tracer, but not 18F-fluorodeoxyglucose, revealed by PET. The increased uptake of choline by HCCs promotes phospholipid formation, DNA hypermethylation, and hepatocyte proliferation. In mice, the CD diet reverses these effects and promotes regression of HCCs that overexpress ß-catenin.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/genética , Mutação , Tomografia por Emissão de Pósitrons , beta Catenina/genética , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Proliferação de Células , Colina/administração & dosagem , Colina/análogos & derivados , Deficiência de Colina/complicações , Metilação de DNA , Dietilnitrosamina , Modelos Animais de Doenças , Genes APC , Predisposição Genética para Doença , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Masculino , Metionina/deficiência , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Fosfolipídeos/metabolismo , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos/administração & dosagem , beta Catenina/metabolismo
6.
J Food Sci ; 84(7): 1900-1908, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31183867

RESUMO

The quality of canola oil is affected by different extraction methods. The effect of cold-pressed canola oil (CPCO) diet and traditional refined bleached deodorized canola oil (RBDCO) diet on lipid accumulation and hepatic steatosis in mice were investigated. The body weight, peroxisome proliferator-activated receptor-α concentration, serum lipid profile, insulin sensitivity, and oxidative stress were increased in mice fed with CPCO diet, which had higher unsaturated fatty acid, tocopherols, phytosterols, and phospholipids but lower saturated fatty acid than RBDCO, after 12 weeks,. Moreover, CPCO significantly increased tocopherols and phytosterols content in liver and reduced liver cholesterol contents and lipid vacuoles accumulation than RBDCO. Also, serum proinflammatory cytokines, 3-hydroxy-3-methylglutary coenzyme A reductase expression level, lipogenic enzymes, and transcriptional factors such as sterol regulatory element-binding proteins 1c, acetyl-CoA carboxylase, and fatty acid synthase in the liver were also markedly downregulated from CPCO diet mice. Overall, CPCO can reduce lipid accumulation and hepatic steatosis by regulating oxidative stress and lipid metabolism in Kun Ming mice compared with RBDCO. PRACTICAL APPLICATION: The results suggested that more bioactive components were contained in cold-pressed canola oil (CPCO) rather than refined bleached deodorized canola oil (RBDCO). CPCO could lower the risk of obesity and hyperlipidemia, reduce lipid accumulation, and prevent hepatic steatosis. It could be considered as a kind of better edible oil than RBDCO.


Assuntos
Fígado Gorduroso/dietoterapia , Metabolismo dos Lipídeos , Estresse Oxidativo , Óleo de Brassica napus/química , Óleo de Brassica napus/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Animais , Colesterol/metabolismo , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/análise , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Humanos , Resistência à Insulina , Lipogênese , Fígado/metabolismo , Masculino , Camundongos , PPAR alfa/genética , PPAR alfa/metabolismo , Fosfolipídeos/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Triglicerídeos/metabolismo
7.
Phys Rev E ; 99(5-1): 052416, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31212483

RESUMO

Phospholipid vesicle membranes are simple models used to study the mechanical properties of cell membranes. The shapes of flaccid vesicles can exhibit very diverse forms. When researching very flaccid vesicles, axisymmetrical vesicles with the membranes adhered to an annular region can also be observed. A phase diagram of such shapes was studied for different values of the vesicle parameters, i.e., the adhesion constant, the vesicle volume-to-membrane ratio, the volume ratio between the polar and the equatorial parts, and the equilibrium difference between the membrane monolayers. The energies of the annular shapes with respect to the vesicle parameters were closely examined and compared with the energies of the discocyte and stomatocyte shapes. The requirements for the existence of such annular shapes were also given for adhesion-free vesicle membranes. The results show that the adhesion between the lipid bilayers stabilizes the observed shapes, which belong to the locally stable branch of the annular vesicles. The value obtained for the adhesion constant of the SOPC membrane is 3×10^{-9}J/m^{2}.


Assuntos
Adesão Celular , Membrana Celular/química , Membrana Celular/metabolismo , Modelos Biológicos , Fosfolipídeos/metabolismo , Pressão , Termodinâmica
8.
Food Chem ; 296: 123-131, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31202296

RESUMO

Phospholipids (PL) rich in conjugated linolenic acid (CLA) have important health effects. Yields of phosphatidylcholine (PC) acidolysis with CLA use to be limited to <30%, due to competitive side-hydrolysis. Duolite A658-Lecitase is a very suitable biocatalyst for this reaction. In this study, PC hydrolysis has been practically eliminated using extremely dried lyophilized PC (279 ±â€¯4 mg water/Kg PC), obtaining close to 100% molar yield of modified PC (72.3% CLA) with Duolite-Lecitase in 24 h, the highest yield reported in the literature for this reaction. It has been better improved by changing the immobilization support, using three food grade hydrophobic supports (Styrene, and two Octadecyl methacrylates (OM and OMC)). In only 2 h, with a 1/12 PC/CLA molar ratio at 50 °C, similar almost quantitative yields of PC with 74.4% CLA content has been obtained using OM-Lecitase. The fatty acid composition of modified PCs is not affected by the enzyme immobilization protocol.


Assuntos
Ácidos Linoleicos Conjugados/metabolismo , Fosfolipases A1/metabolismo , Fosfolipídeos/química , Biocatálise , Cromatografia Gasosa , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Ácidos Graxos/análise , Hidrólise , Ácidos Linoleicos Conjugados/química , Fosfatidilcolinas/química , Fosfolipases A1/química , Fosfolipídeos/metabolismo
9.
Plant Mol Biol ; 101(1-2): 81-93, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201686

RESUMO

KEY MESSAGE: Here we show that accumulation of galactose-containing lipids in plastid membranes in shoots and the other membranes in roots maintains Arabidopsis growth under acidic stress and acidic phosphate deficiency. Soil acidification and phosphate deficiency are closely related to each other in natural environments. In addition to the toxicity of high proton concentrations, acid soil can lead to imbalances of ion availability and nutritional deficiencies, including inorganic phosphate (Pi). Among plants, activation of non-phosphorus-containing galactolipid, digalactosyldiacylglycerol (DGDG), synthesis concomitant with phospholipid degradation, namely membrane lipid remodeling, is crucial for coping with Pi starvation. However, regulation mechanisms of membrane lipid composition during acidic stress have not been clarified. Here, we investigated lipid metabolism in Arabidopsis thaliana grown under acidic stress with or without Pi. Under Pi-sufficient acidic conditions, DGDG was increased in shoot membranes, and some Pi starvation-responsive genes that are involved in lipid remodeling were upregulated without reducing Pi content in leaves. In contrast, under acidic Pi deficiency, membrane lipid remodeling in roots was partially repressed at a lower external pH. Nevertheless, phenotypic comparison between wild type and the double mutant of MGD2/3, which are responsible for DGDG accumulation during Pi starvation, indicated that the complete absence of lipid remodeling in roots resulted in a loss of tolerance to Pi deficiency rather specifically under acidic conditions. This result suggested important physiological roles of galactolipid-enriched membranes under acidic Pi deficiency.


Assuntos
Arabidopsis/fisiologia , Galactolipídeos/metabolismo , Metabolismo dos Lipídeos , Lipídeos de Membrana/metabolismo , Fosfatos/deficiência , Fosfolipídeos/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Concentração de Íons de Hidrogênio , Fenótipo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Brotos de Planta/genética , Brotos de Planta/fisiologia , Plastídeos/metabolismo , Estresse Fisiológico
10.
Food Chem ; 297: 124955, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253342

RESUMO

This study aimed to investigate the effect of hydrogen peroxide (H2O2) on membrane lipids metabolism and its relation to pulp breakdown development of longan fruit during postharvest storage. Compared to the control longans, H2O2-treated longans showed higher pulp breakdown index, cell membrane permeability, and activities of phospholipase D (PLD), lipase and lipoxygenase (LOX). Moreover, H2O2-treated longans maintained higher levels of pulp phosphatidic acid (PA) and saturated fatty acids (SFA). However, H2O2-treated longans exhibited lower levels of pulp phosphatidylcholine (PC), phosphatidylinositol (PI) and unsaturated fatty acids (USFA), lower index of unsaturated fatty acids (IUFA), and lower ratio of USFA to SFA (U/S). These findings demonstrated that H2O2 caused the increased activities of enzymes involving in membrane lipids degradation and the accelerated decompositions of membrane USFA and phospholipids in longan pulp, which eventually triggered the destruction of the pulp cell membrane structure and the development of pulp breakdown in longans during storage.


Assuntos
Enzimas/metabolismo , Frutas/química , Peróxido de Hidrogênio/farmacologia , Lipídeos de Membrana/metabolismo , Sapindaceae/química , Enzimas/química , Ácidos Graxos/análise , Ácidos Graxos/química , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/metabolismo , Peróxido de Hidrogênio/química , Lipase/química , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipoxigenase/química , Lipoxigenase/metabolismo , Lipídeos de Membrana/química , Fosfolipase D/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sapindaceae/efeitos dos fármacos , Sapindaceae/metabolismo
11.
Biochemistry (Mosc) ; 84(2): 164-170, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31216975

RESUMO

Quantitative and qualitative assessments of cell membrane components are essential for the accurate interpretation of processes occurring in biological membranes. Changes in the structure and function of cell membrane components have been linked to oxidative stress. Oxidative stress induced by chronic ethanol consumption or cancer transformation has been implicated in changing the levels of phospholipids and fatty acids in the cell membrane. In this study, we used high-performance liquid chromatography to quantitate the effects of alcohol and malignant transformation on membrane components, namely phospholipids and free fatty acids. Ethanol increased the phospholipid levels. Moreover, the process of malignant transformation was accompanied by increased levels of phospholipids and arachidonic acid as well as decreased levels of linoleic acid and α-linolenic acid. Thus, these oxidative stress-inducing conditions that cause variations in the cellular composition affect the actions of the cell membrane and cell function.


Assuntos
Membrana Celular/metabolismo , Fosfolipídeos/metabolismo , Administração Oral , Intoxicação Alcoólica/tratamento farmacológico , Animais , Ácido Araquidônico/química , Ácido Araquidônico/isolamento & purificação , Ácido Araquidônico/metabolismo , Etanol/administração & dosagem , Etanol/toxicidade , Masculino , Estresse Oxidativo , Fosfolipídeos/química , Fosfolipídeos/isolamento & purificação , Ratos , Ratos Wistar
12.
Nat Commun ; 10(1): 2234, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31110175

RESUMO

The ß2 adrenergic receptor (ß2AR) signals through both Gs and Gi in cardiac myocytes, and the Gi pathway counteracts the Gs pathway. However, Gi coupling is much less efficient than Gs coupling in most cell-based and biochemical assays, making it difficult to study ß2AR-Gi interactions. Here we investigate the role of phospholipid composition on Gs and Gi coupling. While negatively charged phospholipids are known to enhance agonist affinity and stabilize an active state of the ß2AR, we find that they impair coupling to Gi3 and facilitate coupling to Gs. Positively charged Ca2+ and Mg2+, known to interact with the negative charge on phospholipids, facilitates Gi3 coupling. Mutational analysis suggests that Ca2+ coordinates an interaction between phospholipid and the negatively charged EDGE motif on the amino terminal helix of Gi3. Taken together, our observations suggest that local membrane charge modulates the interaction between ß2AR and competing G protein subtypes.


Assuntos
Membrana Celular/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Lipídeos de Membrana/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Motivos de Aminoácidos , Animais , Cátions/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/isolamento & purificação , Lipídeos de Membrana/química , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Células Sf9 , Spodoptera , Eletricidade Estática
13.
Int J Nanomedicine ; 14: 3069-3086, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118623

RESUMO

Background: Synthetic HDLs (sHDLs), small nanodiscs of apolipoprotein mimetic peptides surrounding lipid bilayers, were developed clinically for atheroma regression in cardiovascular patients. Formation of HDL involves interaction of apolipoprotein A-I (ApoA-I) with phospholipid bilayers and assembly into lipid-protein nanodiscs. Purpose: The objective of this study is to improve understanding of physico-chemical aspects of HDL biogenesis such as the thermodynamics of ApoA-I-peptide membrane insertion, lipid binding, and HDL self-assembly to improve our ability to form homogeneous sHDL nanodiscs that are suitable for clinical administration. Methods: The ApoA-I-mimetic peptide, 22A, was combined with either egg sphingomyelin (eSM) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid vesicles to form sHDL. The sHDL assembly process was investigated through lipid vehicle solubilization assays and characterization of purity, size, and morphology of resulting nanoparticles via gel permeation chromatography (GPC), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Peptide-lipid interactions involved were further probed by sum frequency generation (SFG) vibrational spectroscopy and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The pharmacokinetics of eSM-sHDL and POPC-sHDL nanodiscs were investigated in Sprague Dawley rats. Results: sHDL formation was temperature-dependent, with spontaneous formation of sHDL nanoparticles occurring only at temperatures exceeding lipid transition temperatures as evidenced by DLS, GPC, and TEM characterization. SFG and ATR-FTIR spectroscopy findings support a change in peptide-lipid bilayer interactions at temperatures above the lipid transition temperature. Lipid-22A interactions were stronger with eSM than with POPC, which resulted in the formation of more homogeneous sHDL nanoparticles with longer in vivo circulation time as evidenced the PK study. Conclusion: Physico-chemical characteristics of sHDL are in part determined by phospholipid composition. Optimization of phospholipid composition may be utilized to improve the stability and homogeneity of sHDL.


Assuntos
Apolipoproteína A-I/metabolismo , Lipoproteínas HDL/metabolismo , Nanopartículas/química , Peptídeos/metabolismo , Fosfolipídeos/metabolismo , Sequência de Aminoácidos , Animais , Apolipoproteína A-I/química , Difusão Dinâmica da Luz , Cinética , Bicamadas Lipídicas/química , Lipoproteínas HDL/química , Masculino , Nanopartículas/ultraestrutura , Peptídeos/química , Peptídeos/farmacocinética , Fosfatidilcolinas/administração & dosagem , Ratos Sprague-Dawley , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Esfingomielinas/administração & dosagem , Termodinâmica , Vibração
14.
J Mass Spectrom ; 54(6): 557-566, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31038251

RESUMO

Matrix-assisted laser/desorption ionization imaging mass spectrometry (MALDI IMS) is an analytical technique for understanding the spatial distribution of biomolecules across a sample surface. Originally employed for mammalian tissues, this technology has been adapted to study specimens as diverse as microbes and cell cultures, food such as strawberries, and invertebrates including the vinegar fly Drosophila melanogaster. As an ideal model organism, Drosophila has brought greater understanding about conserved biological processes, organism development, and diseased states and even informed management practices of agriculturally and environmentally important species. Drosophila displays anatomically separated renal (Malpighian) tubules that are the physiological equivalent to the vertebrate nephron. Insect Malpighian tubules are also responsible for pesticide detoxification. In this article, we first describe an effective workflow and sample preparation method to study the phospholipid distribution of the Malpighian tubules that initially involves the manual microdissection of the tubules in saline buffer followed by a series of washes to remove excess salt and enhances the phospholipid signals prior to matrix deposition and IMS at 25-µm spatial resolution. We also established a complementary methodology for lipid IMS analysis of whole-body fly sections using a dual-polarity data acquisition approach at the same spatial resolution after matrix deposition by sublimation. Both procedures yield rich signal profiles from the major phospholipid classes. The reproducibility and high-quality results offered by these methodologies enable cohort studies of Drosophila through MALDI IMS.


Assuntos
Drosophila melanogaster/metabolismo , Túbulos de Malpighi/metabolismo , Fosfolipídeos/metabolismo , Animais , Imagem Molecular/métodos , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
15.
Plant Cell Physiol ; 60(7): 1556-1566, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31073607

RESUMO

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.


Assuntos
Brassica napus/genética , Genes de Plantas/genética , Fosfolipase D/genética , Fosfolipídeos/metabolismo , Brassica napus/enzimologia , Brassica napus/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Estudo de Associação Genômica Ampla , Metabolismo dos Lipídeos , Lipídeos/fisiologia , Fosfolipase D/metabolismo , Fosfolipídeos/fisiologia , Filogenia , Folhas de Planta/metabolismo , Estresse Fisiológico , Transcriptoma
16.
Phys Rev E ; 99(2-1): 022414, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30934309

RESUMO

Narrow membrane tubes are commonly pulled out from the surface of phospholipid vesicles using forces applied either through laser or magnetic tweezers or through the action of processive motor proteins. Recent examples have emerged in which an array of such tubes grows spontaneously from vesicles coated with bioactive cytoskeletal filaments (e.g., FtsZ, microtubule) in the presence GTP or ATP. We show how a soft vesicle deforms as a result of the interplay between its topology, local curvature, and the forces due to filament bundles. We present results from dynamically triangulated Monte Carlo simulations of a closed membrane vesicle coated with a nematic field (the filaments), and we show how the intrinsic curvature of the filaments and their bundling interactions drive membrane tubulation. We predict interesting patterns consisting of a large number of nematic defects that accompany tubulation. A common theme emerges: defect locations on vesicle surfaces are hot spots of membrane deformation activity, which could be useful for vesicle origami. Although our equilibrium model is not applicable to the nonequilibrium shape dynamics exhibited by active microtubule-coated vesicles, we show that some of the features, such as the size-dependent vesicle shape and the number of tubes, can still be understood from our equilibrium model.


Assuntos
Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Modelos Moleculares , Membrana Celular/química , Método de Monte Carlo , Fosfolipídeos/metabolismo , Tensão Superficial
17.
Exp Parasitol ; 201: 57-66, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31004571

RESUMO

In the present study, we investigated the in vitro and in vivo leishmanicidal activity of synthetic compounds, containing a semicarbazone scaffold as a peptide mimetic framework. The leishmanicidal effect against amastigotes of Leishmania amazonensis was also evaluated at concentration of 100 µM-0.01 nM. The derivatives 2e, 2f, 2g and 1g, beyond the standards miltefosine and pentamidine, significantly diminished the number of L. amazonensis amastigotes in macrophages. These derivatives were also active against amastigotes of L. braziliensis. As 2g presented potent leishmanicidal activity against the amastigotes of L. amazonensis in macrophages, we also investigated the in vivo leishmanicidal activity of this compound against L. amazonensis. Approximately 105L. amazonensis promastigotes were subcutaneously inoculated into the dermis of the right ear of BALB/c mice, which were subsequently treated with 2g (p.o. or i.p.), miltefosine (p.o.) or glucantime (i.p.) at 30 µmol/kg/day x 28 days. Thus, a similar reduction in the lesion size was observed after the administration of 2g through oral (63.7 ±â€¯10.1%) and intraperitoneal (61.8 ±â€¯3.7%) routes. A larger effect was observed after treatment with miltefosine (97.7 ±â€¯0.4%), and glucantime did not exhibit activity at the dose administered. With respect to the ear parasite load, 2g diminished the number of parasites by p.o. (30.5 ±â€¯5.1%) and i.p. (33.3 ±â€¯4.3%) administration. In addition, 2g induced in vitro apoptosis, autophagy and cell cycle alterations on L. amazonensis promastigotes. In summary, the derivative 2g might represent a lead candidate for antileishmanial drugs, as this compound displayed pronounced leishmanicidal activity.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Semicarbazonas/uso terapêutico , Análise de Variância , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Caspases/análise , Ciclo Celular , Linhagem Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Feminino , Citometria de Fluxo , Concentração Inibidora 50 , Macrófagos/parasitologia , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos BALB C , Pentamidina/química , Pentamidina/farmacologia , Pentamidina/uso terapêutico , Fosfolipídeos/metabolismo , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , Semicarbazonas/química , Semicarbazonas/farmacologia
18.
Biochim Biophys Acta Bioenerg ; 1860(6): 461-468, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30974094

RESUMO

In contrast to plants, algae and cyanobacteria that contain glycolipids as the major lipid components in their photosynthetic membranes, phospholipids are the dominant lipids in the membranes of anoxygenic purple phototrophic bacteria. Although the phospholipid compositions in whole cells or membranes are known for a limited number of the purple bacteria, little is known about the phospholipids associated with individual photosynthetic complexes. In this study, we investigated the phospholipid distributions in both membranes and the light-harvesting 1-reaction center (LH1-RC) complexes purified from several purple sulfur and nonsulfur bacteria. 31P NMR was used for determining the phospholipid compositions and inductively coupled plasma atomic emission spectroscopy was used for measuring the total phosphorous contents. Combining these two techniques, we could determine the numbers of specific phospholipids in the purified LH1-RC complexes. A total of approximate 20-30 phospholipids per LH1-RC were detected as the tightly bound lipids in all species. The results revealed that while cardiolipin (CL) exists as a minor component in the membranes, it became the most abundant phospholipid in the purified core complexes and the sum of CL and phosphatidylglycerol accounted for more than two thirds of the total phospholipids for most species. Preferential association of these anionic phospholipids with the LH1-RC is discussed in the context of the recent high-resolution structure of this complex from Thermochromatium (Tch.) tepidum. The detergent lauryldimethylamine N-oxide was demonstrated to selectively remove phosphatidylethanolamine from the membrane of Tch. tepidum.


Assuntos
Membrana Celular/metabolismo , Chromatiaceae/metabolismo , Complexos de Proteínas Captadores de Luz/metabolismo , Fosfolipídeos/metabolismo , Cromatóforos Bacterianos/química , Cromatóforos Bacterianos/metabolismo , Membrana Celular/química , Chromatiaceae/química , Escherichia coli/química , Escherichia coli/metabolismo , Hyphomicrobiaceae/química , Hyphomicrobiaceae/metabolismo , Complexos de Proteínas Captadores de Luz/química , Ressonância Magnética Nuclear Biomolecular , Fosfolipídeos/química , Rhodobacter sphaeroides/química , Rhodobacter sphaeroides/metabolismo , Rhodospirillum rubrum/química , Rhodospirillum rubrum/metabolismo , Espectrofotometria Atômica
19.
Molecules ; 24(7)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30986911

RESUMO

A number of reports have indicated a relationship between bacterial resistance to antibiotics and their lipid composition. In the present study, we characterized the lipid profiles of American Type Culture Collection (ATCC) and clinical strains of Staphylococcus aureus and its correlation with antibiotic resistance and hydrophobicity. The following strains were used: S. aureus ATCC 6538P, S. aureus ATCC 43300 (MRSA), seven clinical strains from the pharynges, two strains from duodenal ulcers, four strains from hip prostheses, and one strain from the conjunctiva. Lipid-related differentiation was observed across the S. aureus strains: the higher abundance of anteiso-pentadecanoic acid (anteiso-C15:0) and anteiso-heptadecanoic acid (anteiso-C17:0), followed by iso-pentadecanoic acid (iso-C15:0), suggested that these were common lipids. Iso-tridecanoic acid (iso-C13:0) and anteiso-tridecanoic acid (anteiso-C13:0), iso-hexadecanoic acid (iso-C16:0) and anteiso-hexadecanoic acid (anteiso-C16:0), and all forms of octadecanoic acid (C18:0) were usually detected in low abundance. Strains isolated from pharynges showed the highest ratio of branched/straight chains. A distinction in two clusters based on the amount and type of bacterial lipids identified was obtained, which correlated to the antibiotic resistance, the strains origin, and the cell-surface hydrophobicity. We report a potential correlation between the lipid profile of S. aureus strains, site of infection, antibiotic resistance, and cell-surface hydrophobicity. These results, which still need further insights, could be a first step to identifying antibiotic resistance in response to environmental adaptation.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/metabolismo , Cromatografia Gasosa , Resistência Microbiana a Medicamentos , Ácidos Graxos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Fosfolipídeos/metabolismo
20.
Int J Mol Sci ; 20(7)2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30987349

RESUMO

Rab GTPases define the identity and destiny of vesicles. Some of these small GTPases present isoforms that are expressed differentially along developmental stages or in a tissue-specific manner, hence comparative analysis is difficult to achieve. Here, we describe the intracellular distribution and function in lipid transport of the poorly characterized Rab39 isoforms using typical cell biology experimental tools and new ones developed in our laboratory. We show that, despite their amino acid sequence similarity, Rab39a and Rab39b display non-overlapping intracellular distribution. Rab39a localizes in the late endocytic pathway, mainly at multivesicular bodies. In contrast, Rab39b distributes in the secretory network, at the endoplasmic reticulum/cis-Golgi interface. Therefore, Rab39a controls trafficking of lipids (sphingomyelin and phospholipids) segregated at multivesicular bodies, whereas Rab39b transports sphingolipids biosynthesized at the endoplasmic reticulum-Golgi factory. Interestingly, lyso bis-phosphatidic acid is exclusively transported by Rab39a, indicating that both isoforms do not exert identical functions in lipid transport. Conveniently, the requirement of eukaryotic lipids by the intracellular pathogen Chlamydia trachomatis rendered useful for dissecting and distinguishing Rab39a- and Rab39b-controlled trafficking pathways. Our findings provide comparative insights about the different subcellular distribution and function in lipid transport of the two Rab39 isoforms.


Assuntos
Fosfolipídeos/metabolismo , Esfingolipídeos/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Transporte Biológico , Chlamydia trachomatis/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Células HeLa , Humanos , Imagem com Lapso de Tempo
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