Lipid insights最新文献

Effects of Phenylalanine on the Liquid-Expanded and Liquid-Condensed States of Phosphatidylcholine Monolayers. 苯丙氨酸对磷脂酰胆碱单分子膜液-膨胀和液-凝聚状态的影响。

Lipid insights Pub Date : 2019-01-05 eCollection Date: 2019-01-01 DOI: 10.1177/1178635318820923

Andrea C Cutro, E Anibal Disalvo, María A Frías

{"title":"Effects of Phenylalanine on the Liquid-Expanded and Liquid-Condensed States of Phosphatidylcholine Monolayers.","authors":"Andrea C Cutro, E Anibal Disalvo, María A Frías","doi":"10.1177/1178635318820923","DOIUrl":"https://doi.org/10.1177/1178635318820923","url":null,"abstract":"Background: Phenylalanine (Phe) is involved in physiological and pathological processes in cell membranes in which expanded and condensed states coexist. In this direction, it was reported that surface hydration is important for the binding affinity of the amino acid which significantly perturbs 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer structure and morphology. A deeper insight showed that Phe inserts in DPPC monolayer defects as a monomer at pH 5 and forms aggregates that adsorb to the membrane surface generating a reconfiguration of the lipid arrangement in areas of higher packing. This new arrangement in the monolayer causes the reorientation of dipoles of lipid and water molecules which is congruent with the dehydration and surface tension changes reported above. With this background, this article studies the affinity of Phe in liquid-expanded 1,2-dimyristoyl-sn-glycero-3 phosphocholine (LE DMPC) and liquid-condensed 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (LC DPPC) monolayers and their effects on membrane properties.Results: The adsorption of Phe can be described by a cooperative process in non-independent sites suggesting that Phe/lipid systems reorganize to form new structures at a high degree of coverage. Compressibility modulus and Brewster angle microscopy (BAM) images allow to propose that Phe causes a new phase in 1,2-dimyristoyl-sn-glycero-3 phosphocholine (DMPC) and DPPC.Conclusions: Phe imposes new arrangements in the lipid phase to form new structures with different compressibility behavior than lipid binary mixtures of DMPC and DPPC. Phe interaction with the LC and LE phases gives place to a process in which a synergistic effect between non-independent sites can be produced. These features of Phe/lipid interaction would be of great importance to understand the multiple effects of Phe on cell membranes.","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"12 ","pages":"1178635318820923"},"PeriodicalIF":0.0,"publicationDate":"2019-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178635318820923","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36854048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Cholesterol-Binding Sites in GIRK Channels: The Devil is in the Details. GIRK通道中的胆固醇结合位点:细节决定成败。

Lipid insights Pub Date : 2018-02-14 eCollection Date: 2018-01-01 DOI: 10.1177/1178635317754071

Avia Rosenhouse-Dantsker

{"title":"Cholesterol-Binding Sites in GIRK Channels: The Devil is in the Details.","authors":"Avia Rosenhouse-Dantsker","doi":"10.1177/1178635317754071","DOIUrl":"https://doi.org/10.1177/1178635317754071","url":null,"abstract":"In recent years, it has become evident that cholesterol plays a direct role in the modulation of a variety of ion channels. In most cases, cholesterol downregulates channel activity. In contrast, our earlier studies have demonstrated that atrial G protein inwardly rectifying potassium (GIRK) channels are upregulated by cholesterol. Recently, we have shown that hippocampal GIRK currents are also upregulated by cholesterol. A combined computational-experimental approach pointed to putative cholesterol-binding sites in the transmembrane domain of the GIRK2 channel, the primary subunit in hippocampal GIRK channels. In particular, the principal cholesterol-binding site was located in the center of the transmembrane domain in between the inner and outer α-helices of 2 adjacent subunits. Further studies pointed to a similar cholesterol-binding site in GIRK4, a major subunit in atrial GIRK channels. However, a close look at a sequence alignment of the transmembrane helices of the 2 channels reveals surprising differences among the residues that interact with the cholesterol molecule in these 2 channels. Here, we compare the residues that form putative cholesterol-binding sites in GIRK2 and GIRK4 and discuss the similarities and differences among them.","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"11 ","pages":"1178635317754071"},"PeriodicalIF":0.0,"publicationDate":"2018-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178635317754071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35851910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Some Lipid Droplets Are More Equal Than Others: Different Metabolic Lipid Droplet Pools in Hepatic Stellate Cells. 一些脂滴比其他的更平等:肝星状细胞中不同的代谢脂滴池。

Lipid insights Pub Date : 2017-12-15 eCollection Date: 2017-01-01 DOI: 10.1177/1178635317747281

Martijn R Molenaar, Arie B Vaandrager, J Bernd Helms

{"title":"Some Lipid Droplets Are More Equal Than Others: Different Metabolic Lipid Droplet Pools in Hepatic Stellate Cells.","authors":"Martijn R Molenaar, Arie B Vaandrager, J Bernd Helms","doi":"10.1177/1178635317747281","DOIUrl":"https://doi.org/10.1177/1178635317747281","url":null,"abstract":"Hepatic stellate cells (HSCs) are professional lipid-storing cells and are unique in their property to store most of the retinol (vitamin A) as retinyl esters in large-sized lipid droplets. Hepatic stellate cell activation is a critical step in the development of chronic liver disease, as activated HSCs cause fibrosis. During activation, HSCs lose their lipid droplets containing triacylglycerols, cholesteryl esters, and retinyl esters. Lipidomic analysis revealed that the dynamics of disappearance of these different classes of neutral lipids are, however, very different from each other. Although retinyl esters steadily decrease during HSC activation, triacylglycerols have multiple pools one of which becomes transiently enriched in polyunsaturated fatty acids before disappearing. These observations are consistent with the existence of preexisting \"original\" lipid droplets with relatively slow turnover and rapidly recycling lipid droplets that transiently appear during activation of HSCs. Elucidation of the molecular machinery involved in the regulation of these distinct lipid droplet pools may open new avenues for the treatment of liver fibrosis.","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"10 ","pages":"1178635317747281"},"PeriodicalIF":0.0,"publicationDate":"2017-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178635317747281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35687367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 31

Intracellular Lipid Droplets: From Structure to Function. 细胞内脂滴:从结构到功能。

Lipid insights Pub Date : 2017-12-13 eCollection Date: 2017-01-01 DOI: 10.1177/1178635317745518

Stefano Vanni

引用次数: 20

Four Acyltransferases Uniquely Contribute to Phospholipid Heterogeneity in Saccharomyces cerevisiae 四种酰基转移酶对酿酒酵母磷脂异质性的独特贡献

Lipid insights Pub Date : 2016-11-28 DOI: 10.4137/LPI.S40597

P. Oelkers, K. Pokhrel

{"title":"Four Acyltransferases Uniquely Contribute to Phospholipid Heterogeneity in Saccharomyces cerevisiae","authors":"P. Oelkers, K. Pokhrel","doi":"10.4137/LPI.S40597","DOIUrl":"https://doi.org/10.4137/LPI.S40597","url":null,"abstract":"Diverse acyl‐CoA species and acyltransferase isoenzymes are part of a complex system that synthesizes glycerophospholipids and triacylglycerols. Saccharomyces cerevisiae, having four main acyl‐CoA species, two main glycerol‐3‐phosphate 1‐O‐acyltransferases (Gat1p, Gat2p) and two main 1‐acylglycerol‐3‐phosphate O‐acyltransferases (Lpt1p, Slc1p), provides an experimental system of reduced complexity. To comprehensively examine the in vivo contribution of the acyltransferase isoenzymes to phospholipid heterogeneity, haploid yeast with compound mutations were generated: gat1Δlpt1Δ, gat2Δlpt1Δ, gat1Δslc1Δ, and gat2Δslc1Δ. All mutations mildly reduced [3H]palmitic acid incorporation into phospholipids relative to triacylglycerol. Electrospray ionization tandem mass spectrometry analysis of phospholipids identified few differences from wild type in gat1Δlpt1Δ, dramatic differences in gat2Δslc1Δ, and intermediate changes in the other two mutants. The gat2Δslc1Δ yeast, solely expressing Gat1p and Lpt1p, had phospholipids with 10% more unsaturated acyl chains and 20% fewer species with 34 acyl chain carbons. These percent changes varied among phospholipid head group species. Thus, the combined activities of Gat2p and Slc1p seem to promote the production of phospholipids with “mixed” chain lengths (e.g. 16 and 18 carbons). This is particularly true for phosphatidylserine. Head group allocation was also affected in gat2Δslc1Δ yeast which had 15% more phosphatidylethanolamine, 38% less phosphatidylserine, and 85% less phosphatidylglycerol. These alterations slowed growth in rich media at 30 °C by 18% but not in media with non‐fermentable carbon sources. Growth was abrogated in rich media at 18.5 °C or containing 10% ethanol. Therefore, Gat2p and Slc1p primarily dictate appropriate phospholipid acyl chain composition, presumably through de novo synthesis, in several growth conditions. This composition is likely steered by Slc1p selectively pairing acyl chains of different lengths.","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"54 1","pages":"31 - 41"},"PeriodicalIF":0.0,"publicationDate":"2016-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83148490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Current and Emerging Uses of Statins in Clinical Therapeutics: A Review 他汀类药物在临床治疗中的应用综述

Lipid insights Pub Date : 2016-11-14 DOI: 10.4137/LPI.S37450

Jonathan T. Davies, Spencer Delfino, Chad E. Feinberg, Meghan Johnson, Veronica L. Nappi, Joshua T. Olinger, Anthony P. Schwab, H. Swanson

{"title":"Current and Emerging Uses of Statins in Clinical Therapeutics: A Review","authors":"Jonathan T. Davies, Spencer Delfino, Chad E. Feinberg, Meghan Johnson, Veronica L. Nappi, Joshua T. Olinger, Anthony P. Schwab, H. Swanson","doi":"10.4137/LPI.S37450","DOIUrl":"https://doi.org/10.4137/LPI.S37450","url":null,"abstract":"Statins, a class of cholesterol-lowering medications that inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, are commonly administered to treat atherosclerotic cardiovascular disease. Statin use may expand considerably given its potential for treating an array of cholesterol-independent diseases. However, the lack of conclusive evidence supporting these emerging therapeutic uses of statins brings to the fore a number of unanswered questions including uncertainties regarding patient-to-patient variability in response to statins, the most appropriate statin to be used for the desired effect, and the efficacy of statins in treating cholesterol-independent diseases. In this review, the adverse effects, costs, and drug–drug and drug–food interactions associated with statin use are presented. Furthermore, we discuss the pleiotropic effects associated with statins with regard to the onset and progression of autoimmune and inflammatory diseases, cancer, neurodegenerative disorders, strokes, bacterial infections, and human immunodeficiency virus. Understanding these issues will improve the prognosis of patients who are administered statins and potentially expand our ability to treat a wide variety of diseases.","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"18 1","pages":"13 - 29"},"PeriodicalIF":0.0,"publicationDate":"2016-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74048192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 122

Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production 蓖麻油:性质、用途及商业生产工艺参数的优化

Lipid insights Pub Date : 2016-09-07 DOI: 10.4137/LPI.S40233

V. Patel, Gerard G. Dumancas, Lakshmi C. Kasi Viswanath, Randall D. Maples, B. J. J. Subong

引用次数: 223

Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport. 荧光甾醇和胆固醇酯作为细胞内胆固醇转运的探针。

Lipid insights Pub Date : 2016-06-09 eCollection Date: 2015-01-01 DOI: 10.4137/LPI.S31617

Katarzyna A Solanko, Maciej Modzel, Lukasz M Solanko, Daniel Wüstner

{"title":"Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport.","authors":"Katarzyna A Solanko, Maciej Modzel, Lukasz M Solanko, Daniel Wüstner","doi":"10.4137/LPI.S31617","DOIUrl":"https://doi.org/10.4137/LPI.S31617","url":null,"abstract":"Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann-Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. ","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"8 Suppl 1","pages":"95-114"},"PeriodicalIF":0.0,"publicationDate":"2016-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/LPI.S31617","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34601099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 32

Is Spontaneous Translocation of Polar Lipids Between Cellular Organelles Negligible? 细胞器间极性脂质的自发易位可以忽略吗?

Lipid insights Pub Date : 2016-04-27 eCollection Date: 2015-01-01 DOI: 10.4137/LPI.S31616

Pentti Somerharju

引用次数: 16

Tracking Diacylglycerol and Phosphatidic Acid Pools in Budding Yeast. 芽殖酵母中二酰基甘油和磷脂酸池的追踪。

Lipid insights Pub Date : 2016-04-06 eCollection Date: 2015-01-01 DOI: 10.4137/LPI.S31781

Suriakarthiga Ganesan, Brittney N Shabits, Vanina Zaremberg

{"title":"Tracking Diacylglycerol and Phosphatidic Acid Pools in Budding Yeast.","authors":"Suriakarthiga Ganesan, Brittney N Shabits, Vanina Zaremberg","doi":"10.4137/LPI.S31781","DOIUrl":"https://doi.org/10.4137/LPI.S31781","url":null,"abstract":"Phosphatidic acid (PA) and diacylglycerol (DAG) are key signaling molecules and important precursors for the biosynthesis of all glycerolipids found in eukaryotes. Research conducted in the model organism Saccharomyces cerevisiae has been at the forefront of the identification of the enzymes involved in the metabolism and transport of PA and DAG. Both these lipids can alter the local physical properties of membranes by introducing negative curvature, but the anionic nature of the phosphomonoester headgroup in PA sets it apart from DAG. As a result, the mechanisms underlying PA and DAG interaction with other lipids and proteins are notoriously different. This is apparent from the analysis of the protein domains responsible for recognition and binding to each of these lipids. We review the current evidence obtained using the PA-binding proteins and domains fused to fluorescent proteins for in vivo tracking of PA pools in yeast. In addition, we present original results for visualization of DAG pools in yeast using the C1 domain from mammalian PKCδ. An emerging first cellular map of the distribution of PA and DAG pools in actively growing yeast is discussed. ","PeriodicalId":18039,"journal":{"name":"Lipid insights","volume":"8 Suppl 1","pages":"75-85"},"PeriodicalIF":0.0,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/LPI.S31781","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34406270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20