Evaluation of dyslipidemia, lipid ratios, and atherogenic index as cardiovascular risk factors among semi-urban dwellers in Nigeria

PubMed Central

Olamoyegun, Michael Adeyemi; Oluyombo, Rotimi; Asaolu, Stephen Olabode

2016-01-01

Background and Objectives: The increasing frequency of cardiovascular disease (CVD) rests on the presence of major cardiovascular risk factors including dyslipidemia. This dyslipidemia is also a target for the prevention and treatment of many cardiovascular diseases. Hence, identification of individuals at risk of CVD is needed for early identification and prevention. The study was carried out to evaluate dyslipidemia using the lipid ratios and indices instead of just the conventional lipid profile. Methodology: It was a cross-sectional study with 699 participants recruited from semi-urban communities in Nigeria. Anthropometric indices, blood pressure, and fasting lipid profiles were determined. Abnormalities in lipid indices and lipid ratios with atherogenic index were also determined. SPSS software version 17.0 were used for analysis, P < 0.05 was considered statistically significant. Results: There were 699 participants with a mean age of 64.45 ± 15.53 years. Elevated total cholesterol, high low-density lipoprotein-cholesterol, elevated triglyceride, and low high-density lipoprotein were seen in 5.3%, 19.3%, 4.4%, and 76.3% of the participants, respectively. The Castelli's risk index-I (CRI-I) predicted the highest prevalence of predisposition to cardiovascular risk (47.8%) with females being at significantly higher risk (55.2% vs. 29.3%, P < 0.001). Atherogenic coefficient, CRI-II, CHOLIndex, atherogenic index of plasma (AIP) predicted a cardiovascular risk prevalence of 22.5%, 15.9%, 11.2%, and 11.0%, respectively, with no significant difference in between the sexes. Conclusions: Serum lipid ratios and AIP may be used in addition to lipid parameters in clinical practice to assess cardiovascular risks even when lipid profiles are apparently normal. AIP was more gender specific amidst the lipid ratios. PMID:27853034

The role of helper lipids in lipid nanoparticles (LNPs) designed for oligonucleotide delivery.

PubMed

Cheng, Xinwei; Lee, Robert J

2016-04-01

Lipid nanoparticles (LNPs) have shown promise as delivery vehicles for therapeutic oligonucleotides, including antisense oligos (ONs), siRNA, and microRNA mimics and inhibitors. In addition to a cationic lipid, LNPs are typically composed of helper lipids that contribute to their stability and delivery efficiency. Helper lipids with cone-shape geometry favoring the formation hexagonal II phase, such as dioleoylphosphatidylethanolamine (DOPE), can promote endosomal release of ONs. Meanwhile, cylindrical-shaped lipid phosphatidylcholine can provide greater bilayer stability, which is important for in vivo application of LNPs. Cholesterol is often included as a helper that improves intracellular delivery as well as LNP stability in vivo. Inclusion of a PEGylating lipid can enhance LNP colloidal stability in vitro and circulation time in vivo but may reduce uptake and inhibit endosomal release at the cellular level. This problem can be addressed by choosing reversible PEGylation in which the PEG moiety is gradually released in blood circulation. pH-sensitive anionic helper lipids, such as fatty acids and cholesteryl hemisuccinate (CHEMS), can trigger low-pH-induced changes in LNP surface charge and destabilization that can facilitate endosomal release of ONs. Generally speaking, there is no correlation between LNP activity in vitro and in vivo because of differences in factors limiting the efficiency of delivery. Designing LNPs requires the striking of a proper balance between the need for particle stability, long systemic circulation time, and the need for LNP destabilization inside the target cell to release the oligonucleotide cargo, which requires the proper selection of both the cationic and helper lipids. Customized design and empirical optimization is needed for specific applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of blood lipids on global coagulation test results.

PubMed

Kim, Jung-Ah; Kim, Ji-Eun; Song, Sang Hoon; Kim, Hyun Kyung

2015-01-01

High levels of blood lipids have been associated with high levels of coagulation factors. We investigated whether blood lipids influence the results of global coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin generation assay (TGA). PT, aPTT, and TGA, along with procoagulant and anticoagulant factors, were measured in 488 normal individuals. Vitamin K status was assessed with prothrombin-induced by vitamin K absence-II (PIVKA-II). The procoagulant factors II, VII, IX, X, and XI and anticoagulant factors protein C and protein S showed significant correlations with triglyceride, and the procoagulant factors II, V, VII, IX, X, XI, and XII and anticoagulant factors antithrombin and protein C correlated with total cholesterol. There were no correlations of blood lipid levels with PIVKA-II levels. Subjects with high triglyceride levels (≥200 mg/dL) showed shorter PT values than those with lower triglyceride levels. However, aPTT value was not changed in terms of blood lipid levels. In both 1 and 5 pM tissue factor-induced TGAs, subjects in the high-triglyceride or high-cholesterol groups (≥240 mg/dL) had high levels of lag time, time-to-peak, and endogenous thrombin potential. Total cholesterol was a significant determinant of PT and TGA values. High blood lipids were related with increased coagulation activity in a normal population. Our findings are expected to help interpret the global coagulation test results in individuals with high lipid levels.

HdhQ111 Mice Exhibit Tissue Specific Metabolite Profiles that Include Striatal Lipid Accumulation

PubMed Central

Carroll, Jeffrey B.; Deik, Amy; Fossale, Elisa; Weston, Rory M.; Guide, Jolene R.; Arjomand, Jamshid; Kwak, Seung; Clish, Clary B.; MacDonald, Marcy E.

2015-01-01

The HTT CAG expansion mutation causes Huntington’s Disease and is associated with a wide range of cellular consequences, including altered metabolism. The mutant allele is expressed widely, in all tissues, but the striatum and cortex are especially vulnerable to its effects. To more fully understand this tissue-specificity, early in the disease process, we asked whether the metabolic impact of the mutant CAG expanded allele in heterozygous B6.HdhQ111/+ mice would be common across tissues, or whether tissues would have tissue-specific responses and whether such changes may be affected by diet. Specifically, we cross-sectionally examined steady state metabolite concentrations from a range of tissues (plasma, brown adipose tissue, cerebellum, striatum, liver, white adipose tissue), using an established liquid chromatography-mass spectrometry pipeline, from cohorts of 8 month old mutant and wild-type littermate mice that were fed one of two different high-fat diets. The differential response to diet highlighted a proportion of metabolites in all tissues, ranging from 3% (7/219) in the striatum to 12% (25/212) in white adipose tissue. By contrast, the mutant CAG-expanded allele primarily affected brain metabolites, with 14% (30/219) of metabolites significantly altered, compared to wild-type, in striatum and 11% (25/224) in the cerebellum. In general, diet and the CAG-expanded allele both elicited metabolite changes that were predominantly tissue-specific and non-overlapping, with evidence for mutation-by-diet interaction in peripheral tissues most affected by diet. Machine-learning approaches highlighted the accumulation of diverse lipid species as the most genotype-predictive metabolite changes in the striatum. Validation experiments in cell culture demonstrated that lipid accumulation was also a defining feature of mutant HdhQ111 striatal progenitor cells. Thus, metabolite-level responses to the CAG expansion mutation in vivo were tissue specific and most evident

Markers of lipid oxidative damage among office workers exposed intermittently to air pollutants including nanoTiO2 particles.

PubMed

Pelclova, Daniela; Zdimal, Vladimir; Kacer, Petr; Komarc, Martin; Fenclova, Zdenka; Vlckova, Stepanka; Zikova, Nadezda; Schwarz, Jaroslav; Makes, Otakar; Navratil, Tomas; Zakharov, Sergey; Bello, Dhimiter

2017-03-01

Nanoscale titanium dioxide (nanoTiO2) is a commercially important nanomaterial used in numerous applications. Experimental studies with nanotitania have documented lung injury and inflammation, oxidative stress, and genotoxicity. Production workers in TiO2 manufacturing with a high proportion of nanoparticles and a mixture of other air pollutants, such as gases and organic aerosols, had increased markers of oxidative stress, including DNA and protein damage, as well as lipid peroxidation in their exhaled breath condensate (EBC) compared to unexposed controls. Office workers were observed to get intermittent exposures to nanoTiO2 during their process monitoring. The aim of this study was to investigate the impact of such short-term exposures on the markers of health effects in office workers relative to production workers from the same factory. Twenty-two office employees were examined. They were occupationally exposed to (nano)TiO2 aerosol during their daily visits of the production area for an average of 14±9 min/day. Median particle number concentration in office workers while in the production area was 2.32×104/cm3. About 80% of the particles were <100 nm in diameter. A panel of biomarkers of lipid oxidation, specifically malondialdehyde (MDA), 4-hydroxy-trans-hexenal (HHE), 4-hydroxy-trans-nonenal (HNE), 8-isoprostaglandin F2α (8-isoprostane), and aldehydes C6-C12, were studied in the EBC and urine of office workers and 14 unexposed controls. Nine markers of lipid oxidation were elevated in the EBC of office employees relative to controls (p<0.05); only 8-isoprostane and C11 were not increased. Significant association was found in the multivariate analysis between their employment in the TiO2 production plant and EBC markers of lipid oxidation. No association was seen with age, lifestyle factors, or environmental air contamination. The EBC markers in office employees reached about 50% of the levels measured in production workers, and the difference between

Leucine Biosynthesis Is Involved in Regulating High Lipid Accumulation in Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerkhoven, Eduard J.; Kim, Young-Mo; Wei, Siwei

ABSTRACT The yeastYarrowia lipolyticais a potent accumulator of lipids, and lipogenesis in this organism can be influenced by a variety of factors, such as genetics and environmental conditions. Using a multifactorial study, we elucidated the effects of both genetic and environmental factors on regulation of lipogenesis inY. lipolyticaand identified how two opposite regulatory states both result in lipid accumulation. This study involved comparison of a strain overexpressing diacylglycerol acyltransferase (DGA1) with a control strain grown under either nitrogen or carbon limitation conditions. A strong correlation was observed between the responses on the transcript and protein levels. Combination ofDGA1overexpression with nitrogen limitationmore » resulted in a high level of lipid accumulation accompanied by downregulation of several amino acid biosynthetic pathways, including that of leucine in particular, and these changes were further correlated with a decrease in metabolic fluxes. This downregulation was supported by the measured decrease in the level of 2-isopropylmalate, an intermediate of leucine biosynthesis. Combining the multi-omics data with putative transcription factor binding motifs uncovered a contradictory role for TORC1 in controlling lipid accumulation, likely mediated through 2-isopropylmalate and a Leu3-like transcription factor. IMPORTANCEThe ubiquitous metabolism of lipids involves refined regulation, and an enriched understanding of this regulation would have wide implications. Various factors can influence lipid metabolism, including the environment and genetics. We demonstrated, using a multi-omics and multifactorial experimental setup, that multiple factors affect lipid accumulation in the yeastYarrowia lipolytica. Using integrative analysis, we identified novel interactions between nutrient restriction and genetic factors involving regulators that are highly conserved among eukaryotes. Given that lipid metabolism is involved in many

Influence of Blood Lipids on Global Coagulation Test Results

PubMed Central

Kim, Jung-Ah; Kim, Ji-Eun; Song, Sang Hoon

2015-01-01

Background High levels of blood lipids have been associated with high levels of coagulation factors. We investigated whether blood lipids influence the results of global coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin generation assay (TGA). Methods PT, aPTT, and TGA, along with procoagulant and anticoagulant factors, were measured in 488 normal individuals. Vitamin K status was assessed with prothrombin-induced by vitamin K absence-II (PIVKA-II). Results The procoagulant factors II, VII, IX, X, and XI and anticoagulant factors protein C and protein S showed significant correlations with triglyceride, and the procoagulant factors II, V, VII, IX, X, XI, and XII and anticoagulant factors antithrombin and protein C correlated with total cholesterol. There were no correlations of blood lipid levels with PIVKA-II levels. Subjects with high triglyceride levels (≥200 mg/dL) showed shorter PT values than those with lower triglyceride levels. However, aPTT value was not changed in terms of blood lipid levels. In both 1 and 5 pM tissue factor-induced TGAs, subjects in the high-triglyceride or high-cholesterol groups (≥240 mg/dL) had high levels of lag time, time-to-peak, and endogenous thrombin potential. Total cholesterol was a significant determinant of PT and TGA values. Conclusion High blood lipids were related with increased coagulation activity in a normal population. Our findings are expected to help interpret the global coagulation test results in individuals with high lipid levels. PMID:25553275

2011 Plant Lipids: Structure, Metabolism, & Function Gordon Research Conference

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christopher Benning

2011-02-04

This is the second Gordon Research Conference on 'Plant Lipids: Structure, Metabolism & Function'. It covers current topics in lipid structure, metabolism and function in eukaryotic photosynthetic organisms including seed plants, algae, mosses and ferns. Work in photosynthetic bacteria is considered as well as it serves the understanding of specific aspects of lipid metabolism in plants. Breakthroughs are discussed in research on plant lipids as diverse as glycerolipids, sphingolipids, lipids of the cell surface, isoprenoids, fatty acids and their derivatives. The program covers nine concepts at the forefront of research under which afore mentioned plant lipid classes are discussed. Themore » goal is to integrate areas such as lipid signaling, basic lipid metabolism, membrane function, lipid analysis, and lipid engineering to achieve a high level of stimulating interaction among diverse researchers with interests in plant lipids. One Emphasis is on the dynamics and regulation of lipid metabolism during plant cell development and in response to environmental factors.« less

MR-Visible Lipids and the Tumor Microenvironment

PubMed Central

Delikatny, E. James; Chawla, Sanjeev; Leung, Daniel-Joseph; Poptani, Harish

2013-01-01

MR-visible lipids or mobile lipids are defined as lipids that are observable using proton magnetic resonance spectroscopy in cells and in tissues. These MR-visible lipids are composed of triglycerides and cholesterol esters that accumulate in intracellular neutral lipid droplets, where their MR visibility is conferred as a result of the increased molecular motion available in this unique physical environment. This review will discuss factors that lead to the biogenesis of MR-visible lipids in cancer cells and in other cell types such as immune cells and fibroblasts. We focus on the accumulations of mobile lipids that are inducible in cultured cells by a number of stresses, including culture conditions and in response to activating stimuli or apoptotic cell death induced by anticancer drugs. This is compared with animal tumor models, where increases in mobile lipids are observed in response to chemo and radiotherapy, and to human tumors where mobile lipids are observed predominantly in high-grade brain tumors and in regions of necrosis. Conducive conditions for mobile lipid formation in the tumor microenvironment will be discussed including low pH, oxygen availability and the presence of inflammatory cells. It is concluded that MR-visible lipids appear in cancer cells and human tumors as a stress response. Mobile lipids stored as neutral lipid droplets may play a role in detoxification of the cell or act as an alternate energy source, especially in cancer cells, which often grow in ischemic/hypoxic environments. The role of MR-visible lipids in cancer diagnosis and assessment of treatment response both in animal models of cancer as well as human brain tumors will also be discussed. Although technical limitations exist in the accurate detection of intratumoral mobile lipids, early increases in mobile lipids after therapeutic interventions may be used as a potential biomarker for assessing treatment response in cancer. PMID:21538631

Understanding the connection between platelet-activating factor, a UV-induced lipid mediator of inflammation, immune suppression and skin cancer

PubMed Central

Damiani, Elisabetta; Ullrich, Stephen E.

2016-01-01

Lipid mediators of inflammation play important roles in several diseases including skin cancer, the most prevalent type of cancer found in the industrialized world. Ultraviolet (UV) radiation is a complete carcinogen and is the primary cause of skin cancer. UV radiation is also a potent immunosuppressive agent, and UV-induced immunosuppression is a well-known risk factor for skin cancer induction. An essential mediator in this process is the glyercophosphocholine 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine commonly referred to as platelet-activating factor (PAF). PAF is produced by keratinocytes in response to diverse stimuli and exerts its biological effects by binding to a single specific G-protein-coupled receptor (PAF-R) expressed on a variety of cells. This review will attempt to describe how this lipid mediator is involved in transmitting the immunosuppressive signal from the skin to the immune system, starting from its production by keratinocytes, to its role in activating mast cell migration in vivo, and to the mechanisms involved that ultimately lead to immune suppression. Recent findings related to its role in regulating DNA repair and activating epigenetic mechanisms, further pinpoint the importance of this bioactive lipid, which may serve as a critical molecular mediator that links the environment (UVB radiation) to the immune system and the epigenome. PMID:27073146

Multiple beneficial lipids including lecithin detected in the edible invasive mollusk Crepidula fornicata from the French Northeastern Atlantic coast.

PubMed

Dagorn, Flore; Buzin, Florence; Couzinet-Mossion, Aurélie; Decottignies, Priscilla; Viau, Michèle; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

2014-12-22

The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin.

Multiple Beneficial Lipids Including Lecithin Detected in the Edible Invasive Mollusk Crepidula fornicata from the French Northeastern Atlantic Coast

PubMed Central

Dagorn, Flore; Buzin, Florence; Couzinet-Mossion, Aurélie; Decottignies, Priscilla; Viau, Michèle; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

2014-01-01

The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin. PMID:25532566

Thermodynamic and fluorescence studies of the underlying factors in benzyl alcohol-induced lipid interdigitated phase.

PubMed

Chen, C H; Hoye, K; Roth, L G

1996-09-15

To further investigate factors contributing to the action of alcohol in the solute-induced lipid interdigitation phase, thermodynamic and fluorescence polarization measurements were carried out to study the interaction of benzyl alcohol with dipalmitoyl phosphatidylcholine bilayer vesicles. The obtained results were compared with those previously reported for ethanol and cyclohexanol (L. G. Roth and C-H. Chen, Arch. Biochem. Biophys. 296, 207, 1992). Similar to ethanol, benzyl alcohol was found to exhibit a biphasic effect on the enthalpy (delta Hm) and the temperature (tm) of the lipid-phase transition and the steady-state fluorescence polarization (P) monitored by 1,6-diphenyl-1,3,5-hexatriene. At a total concentration of benzyl alcohol < 30 mg/ml (the alcohol concentration in lipid phase < 21 mg/ml), benzyl alcohol was found to exhibit large increases in delta Hm and P, which were correlated with the formation of a lipid interdigitated phase, as evidenced by reported X-ray diffraction data. Combining the results with benzyl alcohol and ethanol suggested that simultaneously large changes in delta Hm and P can be used as an indication of the occurrence of a solute-induced lipid interdigitated phase. The overall interacting force in the formation of this lipid phase, as derived from the interactions of the hydroxyl portion of an alcohol with the lipid phosphate head group and the hydrophobic portion of an alcohol with the lipid hydrocarbon chains, may or may not be dominated by hydrophobic interaction. Although lipid/water partition coefficients and the contribution of hydrophobic interaction to the overall interacting force were comparable between benzyl alcohol and cyclohexanol, benzyl alcohol induced lipid interdigitated phase, but not for cyclohexanol. This was due to the ability of benzyl alcohol to be more effective than cyclohexanol in simultaneously interacting with the phosphate head group and the hydrocarbon chains of lipid.

Epidermal growth factor receptor-targeted lipid nanoparticles retain self-assembled nanostructures and provide high specificity

NASA Astrophysics Data System (ADS)

Zhai, Jiali; Scoble, Judith A.; Li, Nan; Lovrecz, George; Waddington, Lynne J.; Tran, Nhiem; Muir, Benjamin W.; Coia, Gregory; Kirby, Nigel; Drummond, Calum J.; Mulet, Xavier

2015-02-01

Next generation drug delivery utilising nanoparticles incorporates active targeting to specific sites. In this work, we combined targeting with the inherent advantages of self-assembled lipid nanoparticles containing internal nano-structures. Epidermal growth factor receptor (EGFR)-targeting, PEGylated lipid nanoparticles using phytantriol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG-maleimide amphiphiles were created. The self-assembled lipid nanoparticles presented here have internal lyotropic liquid crystalline nano-structures, verified by synchrotron small angle X-ray scattering and cryo-transmission electron microscopy, that offer the potential of high drug loading and enhanced cell penetration. Anti-EGFR Fab' fragments were conjugated to the surface of nanoparticles via a maleimide-thiol reaction at a high conjugation efficiency and retained specificity following conjugation to the nanoparticles. The conjugated nanoparticles were demonstrated to have high affinity for an EGFR target in a ligand binding assay.Next generation drug delivery utilising nanoparticles incorporates active targeting to specific sites. In this work, we combined targeting with the inherent advantages of self-assembled lipid nanoparticles containing internal nano-structures. Epidermal growth factor receptor (EGFR)-targeting, PEGylated lipid nanoparticles using phytantriol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG-maleimide amphiphiles were created. The self-assembled lipid nanoparticles presented here have internal lyotropic liquid crystalline nano-structures, verified by synchrotron small angle X-ray scattering and cryo-transmission electron microscopy, that offer the potential of high drug loading and enhanced cell penetration. Anti-EGFR Fab' fragments were conjugated to the surface of nanoparticles via a maleimide-thiol reaction at a high conjugation efficiency and retained specificity following conjugation to the nanoparticles. The conjugated nanoparticles

Salivary lipids: A review.

PubMed

Matczuk, Jan; Żendzian-Piotrowska, Małgorzata; Maciejczyk, Mateusz; Kurek, Krzysztof

2017-09-01

Saliva is produced by both large and small salivary glands and may be considered one of the most important factors influencing the behavior of oral cavity homeostasis. Secretion of saliva plays an important role in numerous significant biological processes. Saliva facilitates chewing and bolus formation as well as performs protective functions and determines the buffering and antibacterial prosperities of the oral environment. Salivary lipids appear to be a very important component of saliva, as their qualitative and quantitative composition can be changed in various pathological states and human diseases. It has been shown that disturbances in salivary lipid homeostasis are involved in periodontal diseases as well as various systemic disorders (e.g. cystic fibrosis, diabetes and Sjögren's syndrome). However, little is known about the role and composition of salivary lipids and their interaction with other important ingredients of human saliva, including proteins, glycoproteins and salivary mucins. The purpose of this review paper is to present the latest knowledge on salivary lipids in healthy conditions and in oral and systemic diseases.

Lipids and bariatric procedures part 1 of 2: Scientific statement from the National Lipid Association, American Society for Metabolic and Bariatric Surgery, and Obesity Medicine Association: FULL REPORT.

PubMed

Bays, Harold E; Jones, Peter H; Jacobson, Terry A; Cohen, David E; Orringer, Carl E; Kothari, Shanu; Azagury, Dan E; Morton, John; Nguyen, Ninh T; Westman, Eric C; Horn, Deborah B; Scinta, Wendy; Primack, Craig

2016-01-01

Bariatric procedures often improve lipid levels in patients with obesity. This 2 part scientific statement examines the potential lipid benefits of bariatric procedures and represents the contributions from authors representing the National Lipid Association, American Society for Metabolic and Bariatric Surgery, and the Obesity Medicine Association. The foundation for this scientific statement was based on published data through June 2015. Part 1 of this 2 part scientific statement provides an overview of: (1) adipose tissue, cholesterol metabolism, and lipids; (2) bariatric procedures, cholesterol metabolism, and lipids; (3) endocrine factors relevant to lipid influx, synthesis, metabolism, and efflux; (4) immune factors relevant to lipid influx, synthesis, metabolism, and efflux; (5) bariatric procedures, bile acid metabolism, and lipids; and (6) bariatric procedures, intestinal microbiota, and lipids, with specific emphasis on how the alterations in the microbiome by bariatric procedures influence obesity, bile acids, and inflammation, which in turn, may all affect lipid levels. Included in part 2 of this comprehensive scientific statement will be a review of (1) the importance of nutrients (fats, carbohydrates, and proteins) and their absorption on lipid levels; (2) the effects of bariatric procedures on gut hormones and lipid levels; (3) the effects of bariatric procedures on nonlipid cardiovascular disease (CVD) risk factors; (4) the effects of bariatric procedures on lipid levels; (5) effects of bariatric procedures on CVD; and finally, (6) the potential lipid effects of vitamin, mineral, and trace element deficiencies that may occur after bariatric procedures. This document represents the full report of part 1. Copyright © 2016 National Lipid Association. All rights reserved.

Lipids and bariatric procedures part 1 of 2: Scientific statement from the National Lipid Association, American Society for Metabolic and Bariatric Surgery, and Obesity Medicine Association: EXECUTIVE SUMMARY.

PubMed

Bays, Harold E; Jones, Peter H; Jacobson, Terry A; Cohen, David E; Orringer, Carl E; Kothari, Shanu; Azagury, Dan E; Morton, John; Nguyen, Ninh T; Westman, Eric C; Horn, Deborah B; Scinta, Wendy; Primack, Craig

2016-01-01

Bariatric procedures often improve lipid levels in patients with obesity. This 2-part scientific statement examines the potential lipid benefits of bariatric procedures and represents contributions from authors representing the National Lipid Association, American Society for Metabolic and Bariatric Surgery, and the Obesity Medicine Association. The foundation for this scientific statement was based on data published through June 2015. Part 1 of this 2-part scientific statement provides an overview of: (1) adipose tissue, cholesterol metabolism, and lipids; (2) bariatric procedures, cholesterol metabolism, and lipids; (3) endocrine factors relevant to lipid influx, synthesis, metabolism, and efflux; (4) immune factors relevant to lipid influx, synthesis, metabolism, and efflux; (5) bariatric procedures, bile acid metabolism, and lipids; and (6) bariatric procedures, intestinal microbiota, and lipids, with specific emphasis on how the alterations in the microbiome by bariatric procedures influence obesity, bile acids, and inflammation, which in turn, may all affect lipid levels. Included in part 2 of this comprehensive scientific statement will be a review of: (1) the importance of nutrients (fats, carbohydrates, and proteins) and their absorption on lipid levels; (2) the effects of bariatric procedures on gut hormones and lipid levels; (3) the effects of bariatric procedures on nonlipid cardiovascular disease risk factors; (4) the effects of bariatric procedures on lipid levels; (5) effects of bariatric procedures on cardiovascular disease; and finally (6) the potential lipid effects of vitamin, mineral, and trace element deficiencies that may occur after bariatric procedures. This document represents the executive summary of part 1. Copyright © 2016 National Lipid Association. All rights reserved.

Apolipoprotein gene involved in lipid metabolism

DOEpatents

Rubin, Edward [Berkeley, CA; Pennacchio, Len A [Sebastopol, CA

2007-07-03

Methods and materials for studying the effects of a newly identified human gene, APOAV, and the corresponding mouse gene apoAV. The sequences of the genes are given, and transgenic animals which either contain the gene or have the endogenous gene knocked out are described. In addition, single nucleotide polymorphisms (SNPs) in the gene are described and characterized. It is demonstrated that certain SNPs are associated with diseases involving lipids and triglycerides and other metabolic diseases. These SNPs may be used alone or with SNPs from other genes to study individual risk factors. Methods for intervention in lipid diseases, including the screening of drugs to treat lipid-related or diabetic diseases are also disclosed.

Understanding the connection between platelet-activating factor, a UV-induced lipid mediator of inflammation, immune suppression and skin cancer.

PubMed

Damiani, Elisabetta; Ullrich, Stephen E

2016-07-01

Lipid mediators of inflammation play important roles in several diseases including skin cancer, the most prevalent type of cancer found in the industrialized world. Ultraviolet (UV) radiation is a complete carcinogen and is the primary cause of skin cancer. UV radiation is also a potent immunosuppressive agent, and UV-induced immunosuppression is a well-known risk factor for skin cancer induction. An essential mediator in this process is the glyercophosphocholine 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine commonly referred to as platelet-activating factor (PAF). PAF is produced by keratinocytes in response to diverse stimuli and exerts its biological effects by binding to a single specific G-protein-coupled receptor (PAF-R) expressed on a variety of cells. This review will attempt to describe how this lipid mediator is involved in transmitting the immunosuppressive signal from the skin to the immune system, starting from its production by keratinocytes, to its role in activating mast cell migration in vivo, and to the mechanisms involved that ultimately lead to immune suppression. Recent findings related to its role in regulating DNA repair and activating epigenetic mechanisms, further pinpoint the importance of this bioactive lipid, which may serve as a critical molecular mediator that links the environment (UVB radiation) to the immune system and the epigenome. Copyright © 2016 Elsevier B.V. All rights reserved.

Mga2 Transcription Factor Regulates an Oxygen-responsive Lipid Homeostasis Pathway in Fission Yeast*

PubMed Central

Burr, Risa; Stewart, Emerson V.; Shao, Wei; Zhao, Shan; Hannibal-Bach, Hans Kristian; Ejsing, Christer S.; Espenshade, Peter J.

2016-01-01

Eukaryotic lipid synthesis is oxygen-dependent with cholesterol synthesis requiring 11 oxygen molecules and fatty acid desaturation requiring 1 oxygen molecule per double bond. Accordingly, organisms evaluate oxygen availability to control lipid homeostasis. The sterol regulatory element-binding protein (SREBP) transcription factors regulate lipid homeostasis. In mammals, SREBP-2 controls cholesterol biosynthesis, whereas SREBP-1 controls triacylglycerol and glycerophospholipid biosynthesis. In the fission yeast Schizosaccharomyces pombe, the SREBP-2 homolog Sre1 regulates sterol homeostasis in response to changing sterol and oxygen levels. However, notably missing is an SREBP-1 analog that regulates triacylglycerol and glycerophospholipid homeostasis in response to low oxygen. Consistent with this, studies have shown that the Sre1 transcription factor regulates only a fraction of all genes up-regulated under low oxygen. To identify new regulators of low oxygen adaptation, we screened the S. pombe nonessential haploid deletion collection and identified 27 gene deletions sensitive to both low oxygen and cobalt chloride, a hypoxia mimetic. One of these genes, mga2, is a putative transcriptional activator. In the absence of mga2, fission yeast exhibited growth defects under both normoxia and low oxygen conditions. Mga2 transcriptional targets were enriched for lipid metabolism genes, and mga2Δ cells showed disrupted triacylglycerol and glycerophospholipid homeostasis, most notably with an increase in fatty acid saturation. Indeed, addition of exogenous oleic acid to mga2Δ cells rescued the observed growth defects. Together, these results establish Mga2 as a transcriptional regulator of triacylglycerol and glycerophospholipid homeostasis in S. pombe, analogous to mammalian SREBP-1. PMID:27053105

Hacking an Algal Transcription Factor for Lipid Biosynthesis.

PubMed

Chen, Xiulai; Hu, Guipeng; Liu, Liming

2018-03-01

Transcriptional engineering is a viable means for engineering microalgae to produce lipid, but it often results in a trade-off between production and growth. A recent study shows that engineering a single transcriptional regulator enables efficient carbon partitioning to lipid biosynthesis with high biomass productivity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Discovery and refinement of loci associated with lipid levels.

PubMed

Willer, Cristen J; Schmidt, Ellen M; Sengupta, Sebanti; Peloso, Gina M; Gustafsson, Stefan; Kanoni, Stavroula; Ganna, Andrea; Chen, Jin; Buchkovich, Martin L; Mora, Samia; Beckmann, Jacques S; Bragg-Gresham, Jennifer L; Chang, Hsing-Yi; Demirkan, Ayşe; Den Hertog, Heleen M; Do, Ron; Donnelly, Louise A; Ehret, Georg B; Esko, Tõnu; Feitosa, Mary F; Ferreira, Teresa; Fischer, Krista; Fontanillas, Pierre; Fraser, Ross M; Freitag, Daniel F; Gurdasani, Deepti; Heikkilä, Kauko; Hyppönen, Elina; Isaacs, Aaron; Jackson, Anne U; Johansson, Åsa; Johnson, Toby; Kaakinen, Marika; Kettunen, Johannes; Kleber, Marcus E; Li, Xiaohui; Luan, Jian'an; Lyytikäinen, Leo-Pekka; Magnusson, Patrik K E; Mangino, Massimo; Mihailov, Evelin; Montasser, May E; Müller-Nurasyid, Martina; Nolte, Ilja M; O'Connell, Jeffrey R; Palmer, Cameron D; Perola, Markus; Petersen, Ann-Kristin; Sanna, Serena; Saxena, Richa; Service, Susan K; Shah, Sonia; Shungin, Dmitry; Sidore, Carlo; Song, Ci; Strawbridge, Rona J; Surakka, Ida; Tanaka, Toshiko; Teslovich, Tanya M; Thorleifsson, Gudmar; Van den Herik, Evita G; Voight, Benjamin F; Volcik, Kelly A; Waite, Lindsay L; Wong, Andrew; Wu, Ying; Zhang, Weihua; Absher, Devin; Asiki, Gershim; Barroso, Inês; Been, Latonya F; Bolton, Jennifer L; Bonnycastle, Lori L; Brambilla, Paolo; Burnett, Mary S; Cesana, Giancarlo; Dimitriou, Maria; Doney, Alex S F; Döring, Angela; Elliott, Paul; Epstein, Stephen E; Ingi Eyjolfsson, Gudmundur; Gigante, Bruna; Goodarzi, Mark O; Grallert, Harald; Gravito, Martha L; Groves, Christopher J; Hallmans, Göran; Hartikainen, Anna-Liisa; Hayward, Caroline; Hernandez, Dena; Hicks, Andrew A; Holm, Hilma; Hung, Yi-Jen; Illig, Thomas; Jones, Michelle R; Kaleebu, Pontiano; Kastelein, John J P; Khaw, Kay-Tee; Kim, Eric; Klopp, Norman; Komulainen, Pirjo; Kumari, Meena; Langenberg, Claudia; Lehtimäki, Terho; Lin, Shih-Yi; Lindström, Jaana; Loos, Ruth J F; Mach, François; McArdle, Wendy L; Meisinger, Christa; Mitchell, Braxton D; Müller, Gabrielle; Nagaraja, Ramaiah; Narisu, Narisu; Nieminen, Tuomo V M; Nsubuga, Rebecca N; Olafsson, Isleifur; Ong, Ken K; Palotie, Aarno; Papamarkou, Theodore; Pomilla, Cristina; Pouta, Anneli; Rader, Daniel J; Reilly, Muredach P; Ridker, Paul M; Rivadeneira, Fernando; Rudan, Igor; Ruokonen, Aimo; Samani, Nilesh; Scharnagl, Hubert; Seeley, Janet; Silander, Kaisa; Stančáková, Alena; Stirrups, Kathleen; Swift, Amy J; Tiret, Laurence; Uitterlinden, Andre G; van Pelt, L Joost; Vedantam, Sailaja; Wainwright, Nicholas; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilsgaard, Tom; Wilson, James F; Young, Elizabeth H; Zhao, Jing Hua; Adair, Linda S; Arveiler, Dominique; Assimes, Themistocles L; Bandinelli, Stefania; Bennett, Franklyn; Bochud, Murielle; Boehm, Bernhard O; Boomsma, Dorret I; Borecki, Ingrid B; Bornstein, Stefan R; Bovet, Pascal; Burnier, Michel; Campbell, Harry; Chakravarti, Aravinda; Chambers, John C; Chen, Yii-Der Ida; Collins, Francis S; Cooper, Richard S; Danesh, John; Dedoussis, George; de Faire, Ulf; Feranil, Alan B; Ferrières, Jean; Ferrucci, Luigi; Freimer, Nelson B; Gieger, Christian; Groop, Leif C; Gudnason, Vilmundur; Gyllensten, Ulf; Hamsten, Anders; Harris, Tamara B; Hingorani, Aroon; Hirschhorn, Joel N; Hofman, Albert; Hovingh, G Kees; Hsiung, Chao Agnes; Humphries, Steve E; Hunt, Steven C; Hveem, Kristian; Iribarren, Carlos; Järvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kaprio, Jaakko; Kesäniemi, Antero; Kivimaki, Mika; Kooner, Jaspal S; Koudstaal, Peter J; Krauss, Ronald M; Kuh, Diana; Kuusisto, Johanna; Kyvik, Kirsten O; Laakso, Markku; Lakka, Timo A; Lind, Lars; Lindgren, Cecilia M; Martin, Nicholas G; März, Winfried; McCarthy, Mark I; McKenzie, Colin A; Meneton, Pierre; Metspalu, Andres; Moilanen, Leena; Morris, Andrew D; Munroe, Patricia B; Njølstad, Inger; Pedersen, Nancy L; Power, Chris; Pramstaller, Peter P; Price, Jackie F; Psaty, Bruce M; Quertermous, Thomas; Rauramaa, Rainer; Saleheen, Danish; Salomaa, Veikko; Sanghera, Dharambir K; Saramies, Jouko; Schwarz, Peter E H; Sheu, Wayne H-H; Shuldiner, Alan R; Siegbahn, Agneta; Spector, Tim D; Stefansson, Kari; Strachan, David P; Tayo, Bamidele O; Tremoli, Elena; Tuomilehto, Jaakko; Uusitupa, Matti; van Duijn, Cornelia M; Vollenweider, Peter; Wallentin, Lars; Wareham, Nicholas J; Whitfield, John B; Wolffenbuttel, Bruce H R; Ordovas, Jose M; Boerwinkle, Eric; Palmer, Colin N A; Thorsteinsdottir, Unnur; Chasman, Daniel I; Rotter, Jerome I; Franks, Paul W; Ripatti, Samuli; Cupples, L Adrienne; Sandhu, Manjinder S; Rich, Stephen S; Boehnke, Michael; Deloukas, Panos; Kathiresan, Sekar; Mohlke, Karen L; Ingelsson, Erik; Abecasis, Gonçalo R

2013-11-01

Levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides and total cholesterol are heritable, modifiable risk factors for coronary artery disease. To identify new loci and refine known loci influencing these lipids, we examined 188,577 individuals using genome-wide and custom genotyping arrays. We identify and annotate 157 loci associated with lipid levels at P < 5 × 10(-8), including 62 loci not previously associated with lipid levels in humans. Using dense genotyping in individuals of European, East Asian, South Asian and African ancestry, we narrow association signals in 12 loci. We find that loci associated with blood lipid levels are often associated with cardiovascular and metabolic traits, including coronary artery disease, type 2 diabetes, blood pressure, waist-hip ratio and body mass index. Our results demonstrate the value of using genetic data from individuals of diverse ancestry and provide insights into the biological mechanisms regulating blood lipids to guide future genetic, biological and therapeutic research.

Discovery and Refinement of Loci Associated with Lipid Levels

PubMed Central

Peloso, Gina M.; Gustafsson, Stefan; Kanoni, Stavroula; Ganna, Andrea; Chen, Jin; Buchkovich, Martin L.; Mora, Samia; Beckmann, Jacques S.; Bragg-Gresham, Jennifer L.; Chang, Hsing-Yi; Demirkan, Ayşe; Den Hertog, Heleen M.; Do, Ron; Donnelly, Louise A.; Ehret, Georg B.; Esko, Tõnu; Feitosa, Mary F.; Ferreira, Teresa; Fischer, Krista; Fontanillas, Pierre; Fraser, Ross M.; Freitag, Daniel F.; Gurdasani, Deepti; Heikkilä, Kauko; Hyppönen, Elina; Isaacs, Aaron; Jackson, Anne U.; Johansson, Åsa; Johnson, Toby; Kaakinen, Marika; Kettunen, Johannes; Kleber, Marcus E.; Li, Xiaohui; Luan, Jian’an; Lyytikäinen, Leo-Pekka; Magnusson, Patrik K.E.; Mangino, Massimo; Mihailov, Evelin; Montasser, May E.; Müller-Nurasyid, Martina; Nolte, Ilja M.; O’Connell, Jeffrey R.; Palmer, Cameron D.; Perola, Markus; Petersen, Ann-Kristin; Sanna, Serena; Saxena, Richa; Service, Susan K.; Shah, Sonia; Shungin, Dmitry; Sidore, Carlo; Song, Ci; Strawbridge, Rona J.; Surakka, Ida; Tanaka, Toshiko; Teslovich, Tanya M.; Thorleifsson, Gudmar; Van den Herik, Evita G.; Voight, Benjamin F.; Volcik, Kelly A.; Waite, Lindsay L.; Wong, Andrew; Wu, Ying; Zhang, Weihua; Absher, Devin; Asiki, Gershim; Barroso, Inês; Been, Latonya F.; Bolton, Jennifer L.; Bonnycastle, Lori L; Brambilla, Paolo; Burnett, Mary S.; Cesana, Giancarlo; Dimitriou, Maria; Doney, Alex S.F.; Döring, Angela; Elliott, Paul; Epstein, Stephen E.; Ingi Eyjolfsson, Gudmundur; Gigante, Bruna; Goodarzi, Mark O.; Grallert, Harald; Gravito, Martha L.; Groves, Christopher J.; Hallmans, Göran; Hartikainen, Anna-Liisa; Hayward, Caroline; Hernandez, Dena; Hicks, Andrew A.; Holm, Hilma; Hung, Yi-Jen; Illig, Thomas; Jones, Michelle R.; Kaleebu, Pontiano; Kastelein, John J.P.; Khaw, Kay-Tee; Kim, Eric; Klopp, Norman; Komulainen, Pirjo; Kumari, Meena; Langenberg, Claudia; Lehtimäki, Terho; Lin, Shih-Yi; Lindström, Jaana; Loos, Ruth J.F.; Mach, François; McArdle, Wendy L; Meisinger, Christa; Mitchell, Braxton D.; Müller, Gabrielle; Nagaraja, Ramaiah; Narisu, Narisu; Nieminen, Tuomo V.M.; Nsubuga, Rebecca N.; Olafsson, Isleifur; Ong, Ken K.; Palotie, Aarno; Papamarkou, Theodore; Pomilla, Cristina; Pouta, Anneli; Rader, Daniel J.; Reilly, Muredach P.; Ridker, Paul M.; Rivadeneira, Fernando; Rudan, Igor; Ruokonen, Aimo; Samani, Nilesh; Scharnagl, Hubert; Seeley, Janet; Silander, Kaisa; Stančáková, Alena; Stirrups, Kathleen; Swift, Amy J.; Tiret, Laurence; Uitterlinden, Andre G.; van Pelt, L. Joost; Vedantam, Sailaja; Wainwright, Nicholas; Wijmenga, Cisca; Wild, Sarah H.; Willemsen, Gonneke; Wilsgaard, Tom; Wilson, James F.; Young, Elizabeth H.; Zhao, Jing Hua; Adair, Linda S.; Arveiler, Dominique; Assimes, Themistocles L.; Bandinelli, Stefania; Bennett, Franklyn; Bochud, Murielle; Boehm, Bernhard O.; Boomsma, Dorret I.; Borecki, Ingrid B.; Bornstein, Stefan R.; Bovet, Pascal; Burnier, Michel; Campbell, Harry; Chakravarti, Aravinda; Chambers, John C.; Chen, Yii-Der Ida; Collins, Francis S.; Cooper, Richard S.; Danesh, John; Dedoussis, George; de Faire, Ulf; Feranil, Alan B.; Ferrières, Jean; Ferrucci, Luigi; Freimer, Nelson B.; Gieger, Christian; Groop, Leif C.; Gudnason, Vilmundur; Gyllensten, Ulf; Hamsten, Anders; Harris, Tamara B.; Hingorani, Aroon; Hirschhorn, Joel N.; Hofman, Albert; Hovingh, G. Kees; Hsiung, Chao Agnes; Humphries, Steve E.; Hunt, Steven C.; Hveem, Kristian; Iribarren, Carlos; Järvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kaprio, Jaakko; Kesäniemi, Antero; Kivimaki, Mika; Kooner, Jaspal S.; Koudstaal, Peter J.; Krauss, Ronald M.; Kuh, Diana; Kuusisto, Johanna; Kyvik, Kirsten O.; Laakso, Markku; Lakka, Timo A.; Lind, Lars; Lindgren, Cecilia M.; Martin, Nicholas G.; März, Winfried; McCarthy, Mark I.; McKenzie, Colin A.; Meneton, Pierre; Metspalu, Andres; Moilanen, Leena; Morris, Andrew D.; Munroe, Patricia B.; Njølstad, Inger; Pedersen, Nancy L.; Power, Chris; Pramstaller, Peter P.; Price, Jackie F.; Psaty, Bruce M.; Quertermous, Thomas; Rauramaa, Rainer; Saleheen, Danish; Salomaa, Veikko; Sanghera, Dharambir K.; Saramies, Jouko; Schwarz, Peter E.H.; Sheu, Wayne H-H; Shuldiner, Alan R.; Siegbahn, Agneta; Spector, Tim D.; Stefansson, Kari; Strachan, David P.; Tayo, Bamidele O.; Tremoli, Elena; Tuomilehto, Jaakko; Uusitupa, Matti; van Duijn, Cornelia M.; Vollenweider, Peter; Wallentin, Lars; Wareham, Nicholas J.; Whitfield, John B.; Wolffenbuttel, Bruce H.R.; Ordovas, Jose M.; Boerwinkle, Eric; Palmer, Colin N.A.; Thorsteinsdottir, Unnur; Chasman, Daniel I.; Rotter, Jerome I.; Franks, Paul W.; Ripatti, Samuli; Cupples, L. Adrienne; Sandhu, Manjinder S.; Rich, Stephen S.

2013-01-01

Low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, and total cholesterol are heritable, modifiable, risk factors for coronary artery disease. To identify new loci and refine known loci influencing these lipids, we examined 188,578 individuals using genome-wide and custom genotyping arrays. We identify and annotate 157 loci associated with lipid levels at P < 5×10−8, including 62 loci not previously associated with lipid levels in humans. Using dense genotyping in individuals of European, East Asian, South Asian, and African ancestry, we narrow association signals in 12 loci. We find that loci associated with blood lipids are often associated with cardiovascular and metabolic traits including coronary artery disease, type 2 diabetes, blood pressure, waist-hip ratio, and body mass index. Our results illustrate the value of genetic data from individuals of diverse ancestries and provide insights into biological mechanisms regulating blood lipids to guide future genetic, biological, and therapeutic research. PMID:24097068

The SwissLipids knowledgebase for lipid biology

PubMed Central

Liechti, Robin; Hyka-Nouspikel, Nevila; Niknejad, Anne; Gleizes, Anne; Götz, Lou; Kuznetsov, Dmitry; David, Fabrice P.A.; van der Goot, F. Gisou; Riezman, Howard; Bougueleret, Lydie; Xenarios, Ioannis; Bridge, Alan

2015-01-01

Motivation: Lipids are a large and diverse group of biological molecules with roles in membrane formation, energy storage and signaling. Cellular lipidomes may contain tens of thousands of structures, a staggering degree of complexity whose significance is not yet fully understood. High-throughput mass spectrometry-based platforms provide a means to study this complexity, but the interpretation of lipidomic data and its integration with prior knowledge of lipid biology suffers from a lack of appropriate tools to manage the data and extract knowledge from it. Results: To facilitate the description and exploration of lipidomic data and its integration with prior biological knowledge, we have developed a knowledge resource for lipids and their biology—SwissLipids. SwissLipids provides curated knowledge of lipid structures and metabolism which is used to generate an in silico library of feasible lipid structures. These are arranged in a hierarchical classification that links mass spectrometry analytical outputs to all possible lipid structures, metabolic reactions and enzymes. SwissLipids provides a reference namespace for lipidomic data publication, data exploration and hypothesis generation. The current version of SwissLipids includes over 244 000 known and theoretically possible lipid structures, over 800 proteins, and curated links to published knowledge from over 620 peer-reviewed publications. We are continually updating the SwissLipids hierarchy with new lipid categories and new expert curated knowledge. Availability: SwissLipids is freely available at http://www.swisslipids.org/. Contact: alan.bridge@isb-sib.ch Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25943471

Lipids and lipid binding proteins: a perfect match.

PubMed

Glatz, Jan F C

2015-02-01

Lipids serve a great variety of functions, ranging from structural components of biological membranes to signaling molecules affecting various cellular functions. Several of these functions are related to the unique physico-chemical properties shared by all lipid species, i.e., their hydrophobicity. The latter, however, is accompanied by a poor solubility in an aqueous environment and thus a severe limitation in the transport of lipids in aqueous compartments such as blood plasma and the cellular soluble cytoplasm. Specific proteins which can reversibly and non-covalently associate with lipids, designated as lipid binding proteins or lipid chaperones, greatly enhance the aqueous solubility of lipids and facilitate their transport between tissues and within tissue cells. Importantly, transport of lipids across biological membranes also is facilitated by specific (membrane-associated) lipid binding proteins. Together, these lipid binding proteins determine the bio-availability of their ligands, and thereby markedly influence the subsequent processing, utilization, or signaling effect of lipids. The bio-availability of specific lipid species thus is governed by the presence of specific lipid binding proteins, the affinity of these proteins for distinct lipid species, and the presence of competing ligands (including pharmaceutical compounds). Recent studies suggest that post-translational modifications of lipid binding proteins may have great impact on lipid-protein interactions. As a result, several levels of regulation exist that together determine the bio-availability of lipid species. This short review discusses the significance of lipid binding proteins and their potential application as targets for therapeutic intervention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Endothelin-1 Expression Associated with Lipid Peroxidation and Nuclear Factor-κB Activation in Type 2 Diabetes Mellitus Patients with Angiopathy and Limb Amputation.

PubMed

Kuo, Yur-Ren; Chien, Ching-Ming; Kuo, Ming-Jen; Wang, Feng-Sheng; Huang, Eng-Yen; Wang, Ching-Jen

2016-01-01

It is unclear whether diabetic angiopathy is related to oxidative stress-associated endothelial dysfunction. The authors investigated whether alteration of endothelin-1 and lipid peroxide production and activation of nuclear factor-κB expression were involved in lower limb amputation in type 2 diabetes mellitus patients. A total of 135 subjects including 51 type 2 diabetes mellitus patients with major lower extremity amputations and 36 diabetes mellitus patients without limb and vascular complication and 48 normal controls were recruited for this study. The authors measured the plasma soluble endothelin-1 concentrations by a sandwich enzyme immunoassay, and measured oxidative stress as determined by the lipid peroxide byproduct malondialdehyde. Histologic staining and nuclear factor-κB activation determined by electrophoretic mobility shift assay of the amputated vessels were examined. Histologic staining revealed that severe arteriosclerosis with atheroma formation in the amputated diabetic arteries was significantly prominent compared with normal controls. Soluble endothelin-1 concentrations and malondialdehyde levels were increased significantly in diabetic amputation patients compared with other groups (p < 0.001). The nuclear factor-κB binding activity in amputated diabetic stump vessels was more prominent compared with healthy vessels without diabetes mellitus. There was a positive correlation between endothelin-1 and malondialdehyde in patients with diabetic amputation (r = 0.46, p = 0.001). These results suggest that elevation of endothelin-1 and lipid peroxide levels is involved in the pathogenesis of diabetic foot amputation. An increase of lipid peroxide and endothelin-1 associated with nuclear factor-κB activation plays an important role in the development of diabetic angiopathies.

Lipids, oxidized lipids, oxidation-specific epitopes, and Age-related Macular Degeneration.

PubMed

Handa, James T; Cano, Marisol; Wang, Lei; Datta, Sayantan; Liu, Tongyun

2017-04-01

Age-related Macular Degeneration (AMD) is the leading cause of blindness among the elderly in western societies. While antioxidant micronutrient treatment is available for intermediate non-neovascular disease, and effective anti-vascular endothelial growth factor treatment is available for neovascular disease, treatment for early AMD is lacking due to an incomplete understanding of the early molecular events. The role of lipids, which accumulate in the macula, and their oxidation, has emerged as an important factor in disease development. These oxidized lipids can either directly contribute to tissue injury or react with amine on proteins to form oxidation-specific epitopes, which can induce an innate immune response. If inadequately neutralized, the inflammatory response from these epitopes can incite tissue injury during disease development. This review explores how the accumulation of lipids, their oxidation, and the ensuing inflammatory response might contribute to the pathogenesis of AMD. This article is part of a Special Issue entitled: Lipid modification and lipid peroxidation products in innate immunity and inflammation edited by Christoph J. Binder . Copyright © 2016 Elsevier B.V. All rights reserved.

A statistical and experimental approach for assessing the preservation of plant lipids in soil

NASA Astrophysics Data System (ADS)

Mueller, K. E.; Eissenstat, D. M.; Oleksyn, J.; Freeman, K. H.

2011-12-01

Plant-derived lipids contribute to stable soil organic matter, but further interpretations of their abundance in soils are limited because the factors that control lipid preservation are poorly understood. Using data from a long-term field experiment and simple statistical models, we provide novel constraints on several predictors of the concentration of hydrolyzable lipids in forest mineral soils. Focal lipids included common monomers of cutin, suberin, and plant waxes present in tree leaves and roots. Soil lipid concentrations were most strongly influenced by the concentrations of lipids in leaves and roots of the overlying trees, but were also affected by the type of lipid (e.g. alcohols vs. acids), lipid chain length, and whether lipids originated in leaves or roots. Collectively, these factors explained ~80% of the variation in soil lipid concentrations beneath 11 different tree species. In order to use soil lipid analyses to test and improve conceptual models of soil organic matter stabilization, additional studies that provide experimental and quantitative (i.e. statistical) constraints on plant lipid preservation are needed.

Partition coefficients of organic compounds in lipid-water systems and correlations with fish bioconcentration factors

USGS Publications Warehouse

Chiou, C.T.

1985-01-01

Triolein-water partition coefficients (KtW) have been determined for 38 slightly water-soluble organic compounds, and their magnitudes have been compared with the corresponding octanol-water partition coefficients (KOW). In the absence of major solvent-solute interaction effects in the organic solvent phase, the conventional treatment (based on Raoult's law) predicts sharply lower partition coefficients for most of the solutes in triolein because of its considerably higher molecular weight, whereas the Flory-Huggins treatment predicts higher partition coefficients with triolein. The data are in much better agreement with the Flory-Huggins model. As expected from the similarity in the partition coefficients, the water solubility (which was previously found to be the major determinant of the KOW) is also the major determinant for the Ktw. When the published BCF values (bioconcentration factors) of organic compounds in fish are based on the lipid content rather than on total mass, they are approximately equal to the Ktw, which suggests at least near equilibrium for solute partitioning between water and fish lipid. The close correlation between Ktw and Kow suggests that Kow is also a good predictor for lipid-water partition coefficients and bioconcentration factors.

Physical activity, sedentary behavior time and lipid levels in the Observation of Cardiovascular Risk Factors in Luxembourg study.

PubMed

Crichton, Georgina E; Alkerwi, Ala'a

2015-08-11

Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. While many studies have investigated general physical activity (PA) in relation to blood lipid levels, the current study aimed to examine the intensity of activity, including sedentary behavior time, and time spent engaging in moderate and intense PA, with concentrations of HDL and LDL-cholesterol, total cholesterol, and triglycerides. Participants comprised 1331 individuals, aged 18 to 70 years, from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) study, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire (IPAQ). Time spent engaging in sedentary behaviors (screen time on a workday and a day off, and total sitting time on a work day), and moderate and intense PA, were related to levels of HDL and LDL-cholesterol, total cholesterol, and triglycerides. Analyses were conducted in the whole sample, and then with stratification according to BMI (normal weight versus overweight/obese). Both lower screen time during days off and higher intense PA time were significantly associated with higher HDL-cholesterol after full adjustment for socio-demographic factors, dietary factors and smoking (both p < 0.05). In normal weight individuals, consistent positive relations between triglycerides, LDL, and total cholesterol with all sedentary behavior time variables were observed (all p < 0.05; adjusted for age, education, gender). There were no statistically significant associations between any intensity level of PA or sedentary behavior time variable and lipid levels in those overweight or obese. Spending less time in sedentary behaviors, and engaging in medium levels of intense physical activity may be associated with a more favorable blood lipid profile, particularly with regard to levels of HDL and triglycerides.

Effects of Plasma Lipids and Statins on Cognitive Function.

PubMed

Li, Rui; Wang, Tian-Jun; Lyu, Pei-Yuan; Liu, Yang; Chen, Wei-Hong; Fan, Ming-Yue; Xu, Jing

2018-02-20

Dementia is the fourth most common cause of death in developed countries. The relationship between plasma lipids and cognitive function is complex and controversial. Due to the increasing life expectancy of the population, there is an urgent need to control vascular risk factors and to identify therapies to prevent and treat both cognitive impairment and dementia. Here, we reviewed the effects of plasma lipids and statins on cognitive function. We searched the PubMed database for research articles published through November 2017 with key words including "plasma lipids," "hyperlipidemia," "hypercholesterolemia," "statins," and "cognition function." Articles were retrieved and reviewed to analyze the effects of plasma lipids and statins on cognitive function and the mechanisms underlying these effects. Many studies have examined the relationship between plasma lipids and cognitive function, but no definitive conclusions can be drawn. The mechanisms involved may include blood-brain barrier injury, the influence on small blood vessels in the brain, the influence on amyloid deposition, and a neuroprotective effect. To date, most studies of statins and cognition have been observational, with few randomized controlled trials. Therefore, firm conclusions regarding whether mid- or long-term statin use affects cognition function and dementia remain elusive. However, increasing concern exists that statins may be a causative factor for cognitive problems. These adverse effects appear to be rare and likely represent a yet-to-be-defined vulnerability in susceptible individuals. The association between plasma lipids and cognition, the mechanism of the influence of plasma lipids on cognitive function, and the association between statins and cognitive function are complex issues and currently not fully understood. Future research aimed at identifying the mechanisms that underlie the effects of plasma lipids and statins on cognition will not only provide important insight into the

Influence of biological factors on lipid and fibrinogen measurements in young men. An epidemiological study in 2009 recruits.

PubMed

Pitsavos, C; Skoumas, J; Dernellis, J; Toutouza, M; Doulalas, A; Stefanadis, C; Toutouzas, P

1998-11-01

The aim of the present study was to detect significant relationships between lipid and fibrinogen measurements and several biological factors in young men. Medical history was obtained, and plasma lipids, lipoprotein (a) and fibrinogen levels were measured in 2009 male Greek army recruits (mean age 22.37+/-3.03 years) not taking any drugs. Plasma levels were as follows: total cholesterol, 171+/-34 mg x dl(-1), low density lipoprotein (LDL) cholesterol, 111+/-34 mg x dl(-1), high density lipoprotein (HDL) cholesterol, 45+/-10 mg x dl(1), and triglycerides, 74+/-32 mg x dl(-1). Lipoprotein (a) and fibrinogen were 18+/-13 and 278+/-67 mg x dl(-1). The atherosclerotic index, calculated as the ratio of total cholesterol/HDL, was 4+/-1. Analysis of multivariate models that included potentially confounding factors revealed the following: body mass index, season of year during which blood examinations were performed, alcohol consumption, and place of residence were found to be significantly associated with plasma levels of total cholesterol, LDL-cholesterol, fibrinogen and the atherosclerotic index in the pooled population. Season and physical activity were significantly associated with HDL-cholesterol, whereas season and family history of acute myocardial infarction were associated with triglycerides levels. Body mass index, family history of myocardial infarction and physical activity were associated with lipoprotein (a). Body mass index, season, alcohol consumption and place of residence are markers of plasma lipid profile and fibrinogen in young men. A family history of acute myocardial infarction and physical activity are related to lipoprotein (a).

Clusterin deficiency induces lipid accumulation and tissue damage in kidney.

PubMed

Heo, Jung-Yoon; Kim, Ji-Eun; Dan, Yongwook; Kim, Yong-Woon; Kim, Jong-Yeon; Cho, Kyu Hyang; Bae, Young Kyung; Im, Seung-Soon; Liu, Kwang-Hyeon; Song, In-Hwan; Kim, Jae-Ryong; Lee, In-Kyu; Park, So-Young

2018-05-01

Clusterin is a secretory glycoprotein that is involved in multiple physiopathological processes, including lipid metabolism. Previous studies have shown that clusterin prevents hepatic lipid accumulation via suppression of sterol regulatory element-binding protein (SREBP) 1. In this study, we examined the role of clusterin in renal lipid accumulation in clusterin-knockout mice and NRK52e tubular epithelial cells. Clusterin deficiency increased the expression of SREBP1 and its target genes and decreased malonyl-CoA decarboxylase protein levels in the kidney. Expression of the endocytic receptor, megalin, and scavenger receptor class A was increased in clusterin-deficient mice. Functional analysis of lipid metabolism also revealed that lipid uptake and triglyceride synthesis were increased and fatty acid oxidation was reduced, leading to increased lipid accumulation in clusterin-deficient mice. These phenomena were accompanied by mesangial expansion, fibrosis and increased urinary protein-to-creatinine ratio. High-fat feeding aggravated these clusterin deficiency-induced pathological changes. Clusterin knockdown in NRK52e cells increased lipogenic gene expression and lipid levels, whereas overexpression of clusterin by treatment with adenovirus or recombinant clusterin protein suppressed lipogenic gene expression and lipid levels. Transforming growth factor-beta 1 (TGFB1) expression increased in the kidney of clusterin-deficient mice and suppression of TGFB1 in NRK52e cells suppressed lipid accumulation. These results suggest that clusterin deficiency induces renal lipid accumulation by dysregulating the expression of lipid metabolism-related factors and TGFB1, thereby leading to chronic kidney disease. Hence, clusterin may serve as a therapeutic target for lipid-induced chronic kidney disease. © 2018 Society for Endocrinology.

Reversible Nuclear-Lipid-Droplet Morphology Induced by Oleic Acid: A Link to Cellular-Lipid Metabolism

PubMed Central

Lagrutta, Lucía C.; Montero-Villegas, Sandra; Layerenza, Juan P.; Sisti, Martín S.; García de Bravo, Margarita M.

2017-01-01

Neutral lipids—involved in many cellular processes—are stored as lipid droplets (LD), those mainly cytosolic (cLD) along with a small nuclear population (nLD). nLD could be involved in nuclear-lipid homeostasis serving as an endonuclear buffering system that would provide or incorporate lipids and proteins involved in signalling pathways as transcription factors and as enzymes of lipid metabolism and nuclear processes. Our aim was to determine if nLD constituted a dynamic domain. Oleic-acid (OA) added to rat hepatocytes or HepG2 cells in culture produced cellular-phenotypic LD modifications: increases in TAG, CE, C, and PL content and in cLD and nLD numbers and sizes. LD increments were reversed on exclusion of OA and were prevented by inhibition of acyl-CoA synthetase (with Triacsin C) and thus lipid biosynthesis. Under all conditions, nLD corresponded to a small population (2–10%) of total cellular LD. The anabolism triggered by OA, involving morphologic and size changes within the cLD and nLD populations, was reversed by a net balance of catabolism, upon eliminating OA. These catabolic processes included lipolysis and the mobilization of hydrolyzed FA from the LD to cytosolic-oxidation sites. These results would imply that nLD are actively involved in nuclear processes that include lipids. In conclusion, nLD are a dynamic nuclear domain since they are modified by OA through a reversible mechanism in combination with cLD; this process involves acyl-CoA-synthetase activity; ongoing TAG, CE, and PL biosynthesis. Thus, liver nLD and cLD are both dynamic cellular organelles. PMID:28125673

Central nervous system regulation of hepatic lipid and lipoprotein metabolism.

PubMed

Taher, Jennifer; Farr, Sarah; Adeli, Khosrow

2017-02-01

Hepatic lipid and lipoprotein metabolism is an important determinant of fasting dyslipidemia and the development of fatty liver disease. Although endocrine factors like insulin have known effects on hepatic lipid homeostasis, emerging evidence also supports a regulatory role for the central nervous system (CNS) and neuronal networks. This review summarizes evidence implicating a bidirectional liver-brain axis in maintaining metabolic lipid homeostasis, and discusses clinical implications in insulin-resistant states. The liver utilizes sympathetic and parasympathetic afferent and efferent fibers to communicate with key regulatory centers in the brain including the hypothalamus. Hypothalamic anorexigenic and orexigenic peptides signal to the liver via neuronal networks to modulate lipid content and VLDL production. In addition, peripheral hormones such as insulin, leptin, and glucagon-like-peptide-1 exert control over hepatic lipid by acting directly within the CNS or via peripheral nerves. Central regulation of lipid metabolism in other organs including white and brown adipose tissue may also contribute to hepatic lipid content indirectly via free fatty acid release and changes in lipoprotein clearance. The CNS communicates with the liver in a bidirectional manner to regulate hepatic lipid metabolism and lipoprotein production. Impairments in these pathways may contribute to dyslipidemia and hepatic steatosis in insulin-resistant states.

Genetic architecture of lipid traits changes over time and differs by race: Princeton Lipid Follow-up Study.

PubMed

Woo, Jessica G; Morrison, John A; Stroop, Davis M; Aronson Friedman, Lisa; Martin, Lisa J

2014-07-01

Dyslipidemia is a major risk factor for CVD. Previous studies on lipid heritability have largely focused on white populations assessed after the obesity epidemic. Given secular trends and racial differences in lipid levels, this study explored whether lipid heritability is consistent across time and between races. African American and white nuclear families had fasting lipids measured in the 1970s and 22-30 years later. Heritability was estimated, and bivariate analyses between visits were conducted by race using variance components analysis. A total of 1,454 individuals (age 14.1/40.6 for offspring/parents at baseline; 39.6/66.5 at follow-up) in 373 families (286 white, 87 African American) were included. Lipid trait heritabilities were typically stronger during the 1970s than the 2000s. At baseline, additive genetic variation for LDL was significantly lower in African Americans than whites (P = 0.015). Shared genetic contribution to lipid variability over time was significant in both whites (all P < 0.0001) and African Americans (P ≤ 0.05 for total, LDL, and HDL cholesterol). African American families demonstrated shared environmental contributions to lipid variation over time (all P ≤ 0.05). Lower heritability, lower LDL genetic variance, and durable environmental effects across the obesity epidemic in African American families suggest race-specific approaches are needed to clarify the genetic etiology of lipids. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

Proton Gradients as a Key Physical Factor in the Evolution of the Forced Transport Mechanism Across the Lipid Membrane.

PubMed

Strbak, Oliver; Kanuchova, Zuzana; Krafcik, Andrej

2016-11-01

A critical phase in the transition from prebiotic chemistry to biological evolution was apparently an asymmetric ion flow across the lipid membrane. Due to imbalance in the ion flow, the early lipid vesicles could selectively take the necessary molecules from the environment, and release the side-products from the vesicle. Natural proton gradients played a definitively crucial role in this process, since they remain the basis of energy transfer in the present-day cells. On the basis of this supposition, and the premise of the early vesicle membrane's impermeability to protons, we have shown that the emergence of the proton gradient in the lipid vesicle could be a key physical factor in the evolution of the forced transport mechanism (pore formation and active transport) across the lipid bilayer. This driven flow of protons across the membrane is the result of the electrochemical proton gradient and osmotic pressures on the integrity of the lipid vesicle. At a critical number of new lipid molecules incorporated into the vesicle, the energies associated with the creation of the proton gradient exceed the bending stiffness of the lipid membrane, and overlap the free energy of the lipid bilayer pore formation.

Lipid Cell Biology: A Focus on Lipids in Cell Division.

PubMed

Storck, Elisabeth M; Özbalci, Cagakan; Eggert, Ulrike S

2018-06-20

Cells depend on hugely diverse lipidomes for many functions. The actions and structural integrity of the plasma membrane and most organelles also critically depend on membranes and their lipid components. Despite the biological importance of lipids, our understanding of lipid engagement, especially the roles of lipid hydrophobic alkyl side chains, in key cellular processes is still developing. Emerging research has begun to dissect the importance of lipids in intricate events such as cell division. This review discusses how these structurally diverse biomolecules are spatially and temporally regulated during cell division, with a focus on cytokinesis. We analyze how lipids facilitate changes in cellular morphology during division and how they participate in key signaling events. We identify which cytokinesis proteins are associated with membranes, suggesting lipid interactions. More broadly, we highlight key unaddressed questions in lipid cell biology and techniques, including mass spectrometry, advanced imaging, and chemical biology, which will help us gain insights into the functional roles of lipids.

Factors affecting drug encapsulation and stability of lipid-polymer hybrid nanoparticles.

PubMed

Cheow, Wean Sin; Hadinoto, Kunn

2011-07-01

Lipid-polymer hybrid nanoparticles are polymeric nanoparticles enveloped by lipid layers that combine the highly biocompatible nature of lipids with the structural integrity afforded by polymeric nanoparticles. Recognizing them as attractive drug delivery vehicles, antibiotics are encapsulated in the present work into hybrid nanoparticles intended for lung biofilm infection therapy. Modified emulsification-solvent-evaporation methods using lipid as surfactant are employed to prepare the hybrid nanoparticles. Biodegradable poly (lactic-co-glycolic acid) and phosphatidylcholine are used as the polymer and lipid models, respectively. Three fluoroquinolone antibiotics (i.e. levofloxacin, ciprofloxacin, and ofloxacin), which vary in their ionicity, lipophilicity, and aqueous solubility, are used. The hybrid nanoparticles are examined in terms of their drug encapsulation efficiency, drug loading, stability, and in vitro drug release profile. Compared to polymeric nanoparticles prepared using non-lipid surfactants, hybrid nanoparticles in general are larger and exhibit higher drug loading, except for the ciprofloxacin-encapsulated nanoparticles. Hybrid nanoparticles, however, are unstable in salt solutions, but the stability can be conferred by adding TPGS into the formulation. Drug-lipid ionic interactions and drug lipophilicity play important roles in the hybrid nanoparticle preparation. First, interactions between oppositely charged lipid and antibiotic (i.e. ciprofloxacin) during preparation cause failed nanoparticle formation. Charge reversal of the lipid facilitated by adding counterionic surfactants (e.g. stearylamine) must be performed before drug encapsulation can take place. Second, drug loading and the release profile are strongly influenced by drug lipophilicity, where more lipophilic drug (i.e. levofloxacin) exhibit a higher drug loading and a sustained release profile attributed to the interaction with the lipid coat. Copyright © 2011 Elsevier B.V. All

Regulation of Ras Exchange Factors and Cellular Localization of Ras Activation by Lipid Messengers in T Cells

PubMed Central

Jun, Jesse E.; Rubio, Ignacio; Roose, Jeroen P.

2013-01-01

The Ras-MAPK signaling pathway is highly conserved throughout evolution and is activated downstream of a wide range of receptor stimuli. Ras guanine nucleotide exchange factors (RasGEFs) catalyze GTP loading of Ras and play a pivotal role in regulating receptor-ligand induced Ras activity. In T cells, three families of functionally important RasGEFs are expressed: RasGRF, RasGRP, and Son of Sevenless (SOS)-family GEFs. Early on it was recognized that Ras activation is critical for T cell development and that the RasGEFs play an important role herein. More recent work has revealed that nuances in Ras activation appear to significantly impact T cell development and selection. These nuances include distinct biochemical patterns of analog versus digital Ras activation, differences in cellular localization of Ras activation, and intricate interplays between the RasGEFs during distinct T cell developmental stages as revealed by various new mouse models. In many instances, the exact nature of these nuances in Ras activation or how these may result from fine-tuning of the RasGEFs is not understood. One large group of biomolecules critically involved in the control of RasGEFs functions are lipid second messengers. Multiple, yet distinct lipid products are generated following T cell receptor (TCR) stimulation and bind to different domains in the RasGRP and SOS RasGEFs to facilitate the activation of the membrane-anchored Ras GTPases. In this review we highlight how different lipid-based elements are generated by various enzymes downstream of the TCR and other receptors and how these dynamic and interrelated lipid products may fine-tune Ras activation by RasGEFs in developing T cells. PMID:24027568

Lipid mobilising factors specifically associated with cancer cachexia.

PubMed Central

Beck, S. A.; Tisdale, M. J.

1991-01-01

Both urine and plasma from mice and humans with cancer cachexia have been shown to contain higher levels of lipid mobilising activity than normal controls, even after acute starvation. There was no significant increase in the urinary lipid mobilising activity of either mice or humans after acute starvation, suggesting that the material in the cachectic situation was probably not due to an elevation of hormones normally associated with the catabolic state in starvation. Further characterisation of the lipid mobilising activity in the urine of cachectic mice using Sephadex G50 exclusion chromatography showed four distinct peaks of activity of apparent molecular weights of greater than 20, 3, 1.5 and less than 0.7 kDa. No comparable peaks of activity were found in the urine of a non tumour-bearing mouse. The high molecular weight activity was probably formed by aggregation of low molecular weight material, since treatment with 0.5 M NaCl caused dissociation to material with a broad spectrum of molecular weights between 3 and 0.7 kDa. Lipolytic species of similar molecular weights were also found in the urine of cachectic cancer patients, but not in normal urine even after 24 h starvation. The lipid mobilising species may be responsible for catabolism of host adipose tissue in the cachectic state. PMID:2069843

Influenza A Virus Hemagglutinin is Required for the Assembly of Viral Components Including Bundled vRNPs at the Lipid Raft.

PubMed

Takizawa, Naoki; Momose, Fumitaka; Morikawa, Yuko; Nomoto, Akio

2016-09-10

The influenza glycoproteins, hemagglutinin (HA) and neuraminidase (NA), which are associated with the lipid raft, have the potential to initiate virion budding. However, the role of these viral proteins in infectious virion assembly is still unclear. In addition, it is not known how the viral ribonucleoprotein complex (vRNP) is tethered to the budding site. Here, we show that HA is necessary for the efficient progeny virion production and vRNP packaging in the virion. We also found that the level of HA does not affect the bundling of the eight vRNP segments, despite reduced virion production. Detergent solubilization and a subsequent membrane flotation analysis indicated that the accumulation of nucleoprotein, viral polymerases, NA, and matrix protein 1 (M1) in the lipid raft fraction was delayed without HA. Based on our results, we inferred that HA plays a role in the accumulation of viral components, including bundled vRNPs, at the lipid raft.

Autoxidation of unsaturated lipids in food emulsion.

PubMed

Sun, Yue-E; Wang, Wei-Dong; Chen, Hong-Wei; Li, Chao

2011-05-01

Unsaturated lipids having various physiological roles are of significance in biochemistry, nutrition, medicine, and food. However, the susceptibility of lipids to oxidation is a major cause of quality deterioration in food emulsions. The reaction mechanism and factors that influence oxidation are appreciably different for emulsified lipids and bulk lipids. This article gives a brief overview of the current knowledge on autoxidation of oil-in-water food emulsions, especially those that contain unsaturated lipids, which are important in the food industry. Autoxidation of unsaturated lipids in oil-in-water emulsion is discussed, and so also their oxidation mechanism, the major factors influencing oxidation, determination measures, research status, and the problems encountered in recent years. Some effective strategies for controlling lipid oxidation in food emulsion have been presented in this review.

Biologic activity of porphyromonas endodontalis complex lipids.

PubMed

Mirucki, Christopher S; Abedi, Mehran; Jiang, Jin; Zhu, Qiang; Wang, Yu-Hsiung; Safavi, Kamran E; Clark, Robert B; Nichols, Frank C

2014-09-01

Periapical infections secondary to pulpal necrosis are associated with bacterial contamination of the pulp. Porphyromonas endodontalis, a gram-negative organism, is considered to be a pulpal pathogen. P. gingivalis is phylogenetically related to P. endodontalis and synthesizes several classes of novel complex lipids that possess biological activity, including the capacity to promote osteoclastogenesis and osteoclast activation. The purpose of this study was to extract and characterize constituent lipids of P. endodontalis and evaluate their capacity to promote proinflammatory secretory responses in the macrophage cell line, RAW 264.7, as well as their capacity to promote osteoclastogenesis and inhibit osteoblast activity. Constituent lipids of both organisms were fractionated by high-performance liquid chromatography and were structurally characterized using electrospray mass spectrometry or electrospray-mass spectrometry/mass spectrometry. The virulence potential of P. endodontalis lipids was then compared with known biologically active lipids isolated from P. gingivalis. P. endodontalis total lipids were shown to promote tumor necrosis factor alpha secretion from RAW 264.7 cells, and the serine lipid fraction appeared to account for the majority of this effect. P. endodontalis lipid preparations also increased osteoclast formation from RAW 264.7 cells, but osteoblast differentiation in culture was inhibited and appeared to be dependent on Toll-like receptor 2 expression. These effects underscore the importance of P. endodontalis lipids in promoting inflammatory and bone cell activation processes that could lead to periapical pathology. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Differential Roles of Cell Death-inducing DNA Fragmentation Factor-α-like Effector (CIDE) Proteins in Promoting Lipid Droplet Fusion and Growth in Subpopulations of Hepatocytes*♦

PubMed Central

Xu, Wenyi; Wu, Lizhen; Yu, Miao; Chen, Feng-Jung; Arshad, Muhammad; Xia, Xiayu; Ren, Hao; Yu, Jinhai; Xu, Li; Xu, Dijin; Li, John Zhong; Li, Peng; Zhou, Linkang

2016-01-01

Lipid droplets (LDs) are dynamic subcellular organelles whose growth is closely linked to obesity and hepatic steatosis. Cell death-inducing DNA fragmentation factor-α-like effector (CIDE) proteins, including Cidea, Cideb, and Cidec (also called Fsp27), play important roles in lipid metabolism. Cidea and Cidec are LD-associated proteins that promote atypical LD fusion in adipocytes. Here, we find that CIDE proteins are all localized to LD-LD contact sites (LDCSs) and promote lipid transfer, LD fusion, and growth in hepatocytes. We have identified two types of hepatocytes, one with small LDs (small LD-containing hepatocytes, SLHs) and one with large LDs (large LD-containing hepatocytes, LLHs) in the liver. Cideb is localized to LDCSs and promotes lipid exchange and LD fusion in both SLHs and LLHs, whereas Cidea and Cidec are specifically localized to the LDCSs and promote lipid exchange and LD fusion in LLHs. Cideb-deficient SLHs have reduced LD sizes and lower lipid exchange activities. Fasting dramatically induces the expression of Cidea/Cidec and increases the percentage of LLHs in the liver. The majority of the hepatocytes from the liver of obese mice are Cidea/Cidec-positive LLHs. Knocking down Cidea or Cidec significantly reduced lipid storage in the livers of obese animals. Our data reveal that CIDE proteins play differential roles in promoting LD fusion and lipid storage; Cideb promotes lipid storage under normal diet conditions, whereas Cidea and Cidec are responsible for liver steatosis under fasting and obese conditions. PMID:26733203

Differential Roles of Cell Death-inducing DNA Fragmentation Factor-α-like Effector (CIDE) Proteins in Promoting Lipid Droplet Fusion and Growth in Subpopulations of Hepatocytes.

PubMed

Xu, Wenyi; Wu, Lizhen; Yu, Miao; Chen, Feng-Jung; Arshad, Muhammad; Xia, Xiayu; Ren, Hao; Yu, Jinhai; Xu, Li; Xu, Dijin; Li, John Zhong; Li, Peng; Zhou, Linkang

2016-02-26

Lipid droplets (LDs) are dynamic subcellular organelles whose growth is closely linked to obesity and hepatic steatosis. Cell death-inducing DNA fragmentation factor-α-like effector (CIDE) proteins, including Cidea, Cideb, and Cidec (also called Fsp27), play important roles in lipid metabolism. Cidea and Cidec are LD-associated proteins that promote atypical LD fusion in adipocytes. Here, we find that CIDE proteins are all localized to LD-LD contact sites (LDCSs) and promote lipid transfer, LD fusion, and growth in hepatocytes. We have identified two types of hepatocytes, one with small LDs (small LD-containing hepatocytes, SLHs) and one with large LDs (large LD-containing hepatocytes, LLHs) in the liver. Cideb is localized to LDCSs and promotes lipid exchange and LD fusion in both SLHs and LLHs, whereas Cidea and Cidec are specifically localized to the LDCSs and promote lipid exchange and LD fusion in LLHs. Cideb-deficient SLHs have reduced LD sizes and lower lipid exchange activities. Fasting dramatically induces the expression of Cidea/Cidec and increases the percentage of LLHs in the liver. The majority of the hepatocytes from the liver of obese mice are Cidea/Cidec-positive LLHs. Knocking down Cidea or Cidec significantly reduced lipid storage in the livers of obese animals. Our data reveal that CIDE proteins play differential roles in promoting LD fusion and lipid storage; Cideb promotes lipid storage under normal diet conditions, whereas Cidea and Cidec are responsible for liver steatosis under fasting and obese conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Consensus clinical recommendations for the management of plasma lipid disorders in the Middle East.

PubMed

Al Sayed, Nasreen; Al Waili, Khalid; Alawadi, Fatheya; Al-Ghamdi, Saeed; Al Mahmeed, Wael; Al-Nouri, Fahad; Al Rukhaimi, Mona; Al-Rasadi, Khalid; Awan, Zuhier; Farghaly, Mohamed; Hassanein, Mohamed; Sabbour, Hani; Zubaid, Mohammad; Barter, Philip

2016-12-15

Plasma lipid disorders are key risk factors for the development of atherosclerotic cardiovascular disease (ASCVD) and are prevalent in the Middle East, with rates increasing in recent decades. Despite this, no region-specific guidelines for managing plasma lipids exist and there is a lack of use of guidelines developed in other regions. A multidisciplinary panel of regional experts was convened to develop consensus clinical recommendations for the management of plasma lipids in the Middle East. The panel considered existing international guidelines and regional clinical experience to develop recommendations. The panel's recommendations include plasma lipid screening, ASCVD risk calculation and treatment considerations. The panel recommend that plasma lipid levels should be measured in all at-risk patients and at regular intervals in all adults from the age of 20years. A scoring system should be used to calculate ASCVD risk that includes known lipid and non-lipid risk factors. Primary treatment targets include low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol. Lifestyle modifications should be first-line treatment for all patients; the first-line pharmacological treatment targeting plasma lipids in patients at moderate-to-high risk of ASCVD is statin therapy, with a number of adjunctive or second-line agents available. Guidance is also provided on the management of underlying conditions and special populations; of particular pertinence in the region are familial hypercholesterolaemia, diabetes and metabolic dyslipidaemia. These consensus clinical recommendations provide practicing clinicians with comprehensive, region-specific guidance to improve the detection and management of plasma lipid disorders in patients in the Middle East. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Serum Lipid Profile, Prevalence of Dyslipidaemia, and Associated Risk Factors Among Northern Mexican Adolescents.

PubMed

Bibiloni, Maria Del Mar; Salas, Rogelio; De la Garza, Yolanda E; Villarreal, Jesus Z; Sureda, Antoni; Tur, Josep A

2016-11-01

The increase in overweight and obese children and adolescents may be linked to increased rates of dyslipidaemia. The aim was to assess the serum lipid profile, the prevalence of dyslipidaemia, and associated risk factors among the North Mexican adolescent population. Two hundred and ninety-three subjects (47.8% girls) ages 11 to 16 years took part in the Nuevo León State Survey of Nutrition and Health 2011-2012. According to the 2011 Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents, dyslipidaemia was defined as a presence of ≥1 of the following levels (mg/dL): Total cholesterol ≥200, low-density lipoprotein cholesterol ≥130, non-high-density lipoprotein cholesterol <40, and triglyceride ≥130. The overall frequency of dyslipidaemia was 48.8% with no differences between sexes. Adolescents with high body mass index were more likely to have at least 1 abnormal lipid level (overweight: odds ratio [OR]: 2.07; 95% confidence interval [CI]: 1.14-3.77, P < 0.05; obesity: OR: 2.21, 95% CI: 1.11-4.41, P < 0.05) than those with normal weight. Abdominally subjects with obesity were also more likely to have at least 1 abnormal lipid level (OR: 2.30; 95% CI: 1.35-3.91, P < 0.01) than their leaner counterparts. Half of Mexican adolescents living in the State of Nuevo León have at least 1 abnormal lipid concentration. Low HDL-chol level was the most common dyslipidaemia. Body mass index and abdominal obesity were associated with the prevalence of at least 1 abnormal lipid level.

Effect of tension and curvature on the chemical potential of lipids in lipid aggregates.

PubMed

Grafmüller, Andrea; Lipowsky, Reinhard; Knecht, Volker

2013-01-21

Understanding the factors that influence the free energy of lipids in bilayer membranes is an essential step toward understanding exchange processes of lipids between membranes. In general, both lipid composition and membrane geometry can affect lipid exchange rates between bilayer membranes. Here, the free energy change ΔG(des) for the desorption of dipalmitoyl-phosphatidylcholine (DPPC) lipids from different lipid aggregates has been computed using molecular dynamics simulations and umbrella sampling. The value of ΔG(des) is found to depend strongly on the local properties of the aggregate, in that both tension and curvature lead to an increase in ΔG(des). A detailed analysis shows that the increased desorption free energy for tense bilayers arises from the increased conformational entropy of the lipid tails, which reduces the favorable component -TΔS(L) of the desorption free energy.

APP Function and Lipids: A Bidirectional Link

PubMed Central

Grimm, Marcus O. W.; Mett, Janine; Grimm, Heike S.; Hartmann, Tobias

2017-01-01

Extracellular neuritic plaques, composed of aggregated amyloid-β (Aβ) peptides, are one of the major histopathological hallmarks of Alzheimer’s disease (AD), a progressive, irreversible neurodegenerative disorder and the most common cause of dementia in the elderly. One of the most prominent risk factor for sporadic AD, carrying one or two aberrant copies of the apolipoprotein E (ApoE) ε4 alleles, closely links AD to lipids. Further, several lipid classes and fatty acids have been reported to be changed in the brain of AD-affected individuals. Interestingly, the observed lipid changes in the brain seem not only to be a consequence of the disease but also modulate Aβ generation. In line with these observations, protective lipids being able to decrease Aβ generation and also potential negative lipids in respect to AD were identified. Mechanistically, Aβ peptides are generated by sequential proteolytic processing of the amyloid precursor protein (APP) by β- and γ-secretase. The α-secretase appears to compete with β-secretase for the initial cleavage of APP, preventing Aβ production. All APP-cleaving secretases as well as APP are transmembrane proteins, further illustrating the impact of lipids on Aβ generation. Beside the pathological impact of Aβ, accumulating evidence suggests that Aβ and the APP intracellular domain (AICD) play an important role in regulating lipid homeostasis, either by direct effects or by affecting gene expression or protein stability of enzymes involved in the de novo synthesis of different lipid classes. This review summarizes the current literature addressing the complex bidirectional link between lipids and AD and APP processing including lipid alterations found in AD post mortem brains, lipids that alter APP processing and the physiological functions of Aβ and AICD in the regulation of several lipid metabolism pathways. PMID:28344547

Genetics of Lipid-Storage Management in Caenorhabditis elegans Embryos

PubMed Central

Schmökel, Verena; Memar, Nadin; Wiekenberg, Anne; Trotzmüller, Martin; Schnabel, Ralf; Döring, Frank

2016-01-01

Lipids play a pivotal role in embryogenesis as structural components of cellular membranes, as a source of energy, and as signaling molecules. On the basis of a collection of temperature-sensitive embryonic lethal mutants, a systematic database search, and a subsequent microscopic analysis of >300 interference RNA (RNAi)–treated/mutant worms, we identified a couple of evolutionary conserved genes associated with lipid storage in Caenorhabditis elegans embryos. The genes include cpl-1 (cathepsin L–like cysteine protease), ccz-1 (guanine nucleotide exchange factor subunit), and asm-3 (acid sphingomyelinase), which is closely related to the human Niemann-Pick disease–causing gene SMPD1. The respective mutant embryos accumulate enlarged droplets of neutral lipids (cpl-1) and yolk-containing lipid droplets (ccz-1) or have larger genuine lipid droplets (asm-3). The asm-3 mutant embryos additionally showed an enhanced resistance against C band ultraviolet (UV-C) light. Herein we propose that cpl-1, ccz-1, and asm-3 are genes required for the processing of lipid-containing droplets in C. elegans embryos. Owing to the high levels of conservation, the identified genes are also useful in studies of embryonic lipid storage in other organisms. PMID:26773047

Serum Lipid Profile, Prevalence of Dyslipidaemia, and Associated Risk Factors Among Northern Mexican Adolescents

PubMed Central

Bibiloni, Maria del Mar; Salas, Rogelio; De la Garza, Yolanda E.; Villarreal, Jesus Z.; Sureda, Antoni; Tur, Josep A.

2016-01-01

ABSTRACT Background: The increase in overweight and obese children and adolescents may be linked to increased rates of dyslipidaemia. The aim was to assess the serum lipid profile, the prevalence of dyslipidaemia, and associated risk factors among the North Mexican adolescent population. Methods: Two hundred and ninety-three subjects (47.8% girls) ages 11 to 16 years took part in the Nuevo León State Survey of Nutrition and Health 2011–2012. According to the 2011 Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents, dyslipidaemia was defined as a presence of ≥1 of the following levels (mg/dL): Total cholesterol ≥200, low-density lipoprotein cholesterol ≥130, non–high-density lipoprotein cholesterol <40, and triglyceride ≥130. Results: The overall frequency of dyslipidaemia was 48.8% with no differences between sexes. Adolescents with high body mass index were more likely to have at least 1 abnormal lipid level (overweight: odds ratio [OR]: 2.07; 95% confidence interval [CI]: 1.14–3.77, P < 0.05; obesity: OR: 2.21, 95% CI: 1.11–4.41, P < 0.05) than those with normal weight. Abdominally subjects with obesity were also more likely to have at least 1 abnormal lipid level (OR: 2.30; 95% CI: 1.35–3.91, P < 0.01) than their leaner counterparts. Conclusions: Half of Mexican adolescents living in the State of Nuevo León have at least 1 abnormal lipid concentration. Low HDL-chol level was the most common dyslipidaemia. Body mass index and abdominal obesity were associated with the prevalence of at least 1 abnormal lipid level. PMID:27379432

Lipid mediators and their metabolism in the nucleous: implications for Alzheimer's disease.

PubMed

Farooqui, Akhlaq A

2012-01-01

Lipid mediators are important endogenous regulators derived from enzymatic degradation of glycerophospholipids, sphingolipids, and cholesterol by phospholipases, sphingomyelinases, and cytochrome P450 hydroxylases, respectively. In neural cells, lipid mediators are associated with proliferation, differentiation, oxidative stress, inflammation, and apoptosis. A major group of lipid mediators, which originates from the enzymatic oxidation of arachidonic acid, is called eicosanoids (i.e., prostaglandins, leukotrienes, thromboxanes, and lipoxins). The corresponding lipid mediators of docosahexaenoic acid metabolism are named as docosanoids. They include resolvins, protectins (neuroprotectins), and maresins. Docosanoids produce antioxidant, anti-inflammatory, and antiapoptotic effects in brain tissue. Other glycerophospholipid-derived lipid mediators are platelet activating factor, lysophosphatidic acid, and endocannabinoids. Degradation of sphingolipids also results in the generation of sphingolipid-derived lipid mediators, such as ceramide, ceramide 1-phosphate, sphingosine, and sphingosine 1-phosphate. These mediators are involved in differentiation, growth, cell migration, and apoptosis. Similarly, cholesterol-derived lipid mediators, hydroxycholesterol, produce apoptosis. Abnormal metabolism of lipid mediators may be closely associated with pathogenesis of Alzheimer's disease.

Metals and lipid oxidation. Contemporary issues.

PubMed

Schaich, K M

1992-03-01

Lipid oxidation is now recognized to be a critically important reaction in physiological and toxicological processes as well as in food products. This provides compelling reasons to understand what causes lipid oxidation in order to be able to prevent or control the reactions. Redox-active metals are major factors catalyzing lipid oxidation in biological systems. Classical mechanisms of direct electron transfer to double bonds by higher valence metals and of reduction of hydroperoxides by lower valence metals do not always account for patterns of metal catalysis of lipid oxidation in multiphasic or compartmentalized biological systems. To explain why oxidation kinetics, mechanisms, and products in molecular environments which are both chemically and physically complex often do not follow classical patterns predicted by model system studies, increased consideration must be given to five contemporary issues regarding metal catalysis of lipid oxidation: hypervalent non-heme iron or iron-oxygen complexes, heme catalysis mechanism(s), compartmentalization of reactions and lipid phase reactions of metals, effects of metals on product mixes, and factors affecting the mode of metal catalytic action.

Retinal lipid and glucose metabolism dictates angiogenesis through lipid sensor Ffar1

PubMed Central

Joyal, Jean-Sébastien; Sun, Ye; Gantner, Marin L.; Shao, Zhuo; Evans, Lucy P.; Saba, Nicholas; Fredrick, Thomas; Burnim, Samuel; Kim, Jin Sung; Patel, Gauri; Juan, Aimee M.; Hurst, Christian G.; Hatton, Colman J.; Cui, Zhenghao; Pierce, Kerry A.; Bherer, Patrick; Aguilar, Edith; Powner, Michael B.; Vevis, Kristis; Boisvert, Michel; Fu, Zhongjie; Levy, Emile; Fruttiger, Marcus; Packard, Alan; Rezende, Flavio A.; Maranda, Bruno; Sapieha, Przemyslaw; Chen, Jing; Friedlander, Martin; Clish, Clary B.; Smith, Lois E.H.

2016-01-01

Tissues with high metabolic rates often use lipid as well as glucose for energy, conferring a survival advantage during feast and famine.1 Current dogma suggests that high-energy consuming photoreceptors depend on glucose.2,3 Here we show that retina also uses fatty acids (FA) β-oxidation for energy. Moreover, we identify a lipid sensor Ffar1 that curbs glucose uptake when FA are available. Very low-density lipoprotein receptor (VLDLR), expressed in tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived FA.4,5 Vldlr is present in photoreceptors.6 In Vldlr−/− retinas, Ffar1, sensing high circulating lipid levels despite decreased FA uptake5, suppresses glucose transporter Glut1. This impaired glucose entry into photoreceptors results in a dual lipid/glucose fuel shortage and reduction in the Krebs cycle intermediate α-ketoglutarate (KG). Low α-KG levels promote hypoxia-induced factor-1α (Hif1a) stabilization and vascular endothelial growth factor (Vegfa) secretion by starved Vldlr−/− photoreceptors, attracting neovessels to supply fuel. These aberrant vessels invading normally avascular photoreceptors in Vldlr−/− retinas are reminiscent of retinal angiomatous proliferation (RAP), a subset of neovascular age-related macular degeneration (AMD)7, associated with high vitreous VEGF levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in neovascular AMD and other retinal diseases. PMID:26974308

Lipid stability in meat and meat products.

PubMed

Morrissey, P A; Sheehy, P J; Galvin, K; Kerry, J P; Buckley, D J

1998-01-01

Lipid oxidation is one of the main factors limiting the quality and acceptability of meats and meat products. Oxidative damage to lipids occurs in the living animal because of an imbalance between the production of reactive oxygen species and the animal's defence mechanisms. This may be brought about by a high intake of oxidized lipids or poly-unsaturated fatty acids, or a low intake of nutrients involved in the antioxidant defence system. Damage to lipids may be accentuated in the immediate post-slaughter period and, in particular, during handling, processing, storage and cooking. In recent years, pressure to reduce artificial additive use in foods has led to attempts to increase meat stability by dietary strategies. These include supplementation of animal diets with vitamin E, ascorbic acid, or carotenoids, or withdrawal of trace mineral supplements. Dietary vitamin E supplementation reduces lipid and myoglobin oxidation, and, in certain situations, drip losses in meats. However, vitamin C supplementation appears to have little, if any, beneficial effects on meat stability. The effect of feeding higher levels of carotenoids on meat stability requires further study. Some studies have demonstrated that reducing the iron and copper content of feeds improves meat stability. Post-slaughter carnosine addition may be an effective means of improving lipid stability in processed meats, perhaps in combination with dietary vitamin E supplementation.

Lipid Metabolism and Lipid Droplets in Pancreatic Cancer and Stellate Cells

PubMed Central

Sunami, Yoshiaki; Rebelo, Artur; Kleeff, Jörg

2017-01-01

Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second deadliest cancer by 2030, and the overall 5-year survival rate is currently less than 7%. Cancer cells frequently exhibit reprogramming of their metabolic activity. It is increasingly recognized that aberrant de novo lipid synthesis and reprogrammed lipid metabolism are both associated with the development and progression of various cancers, including pancreatic cancer. In this review, the current knowledge about lipid metabolism and lipid droplets in pancreatic cancer is discussed. In the first part, molecular mechanisms of lipid metabolism and roles of enzymes involved in lipid metabolism which are relevant for pancreatic cancer research are presented. Further, preclinical studies and clinical trials with drugs/inhibitors targeting cancer metabolic systems in cancer are summarized. An increase of our knowledge in lipid metabolism in pancreatic cancer cells and in tumor stroma is important for developing novel strategies of future individualized therapies of pancreatic cancer. PMID:29295482

Applications of lipid based formulation technologies in the delivery of biotechnology-based therapeutics.

PubMed

du Plessis, Lissinda H; Marais, Etienne B; Mohammed, Faruq; Kotzé, Awie F

2014-01-01

In the last decades several new biotechnologically-based therapeutics have been developed due to progress in genetic engineering. A growing challenge facing pharmaceutical scientists is formulating these compounds into oral dosage forms with adequate bioavailability. An increasingly popular approach to formulate biotechnology-based therapeutics is the use of lipid based formulation technologies. This review highlights the importance of lipid based drug delivery systems in the formulation of oral biotechnology based therapeutics including peptides, proteins, DNA, siRNA and vaccines. The different production procedures used to achieve high encapsulation efficiencies of the bioactives are discussed, as well as the factors influencing the choice of excipient. Lipid based colloidal drug delivery systems including liposomes and solid lipid nanoparticles are reviewed with a focus on recent advances and updates. We further describe microemulsions and self-emulsifying drug delivery systems and recent findings on bioactive delivery. We conclude the review with a few examples on novel lipid based formulation technologies.

Lipid profile in cerebrovascular accidents.

PubMed

Togha, Mansoureh; Gheini, Mohamad Reza; Ahmadi, Babak; Khashaiar, Patricia; Razeghi, Soodeh

2011-01-01

Changes in the lipid profile have been suggested as a risk factor for developing ischemic stroke. Their role in intra-cerebral hemorrhage, however, is not clear. The present study was designed to evaluate the lipid profile levels of patients who had experienced an acute stroke during the first 24-hour and to compare these levels in different patients suffering from the stroke, either hemorrhagic or ischemic, and healthy individuals. In this cross-sectional study, 258 consecutive patients with acute stroke admitted to the neurology department of our center during September 2006 and September 2007 were studied. As for the control group, 187 apparently healthy subjects living in the same community and matched for age and sex were selected. Lipid profile was measured and compared between the three groups. In the patients' group, 65 suffered from hemorrhagic stroke (group 1) and the other 193 had ischemic stroke (group 2). Except for TG values, there was no significant difference among the ischemic and hemorrhagic lipid profile. Age, cholesterol, and LDL influenced the risk of developing an ischemic stroke; TG was not reported as a risk factor or a protective one. While the comparison of data retrieved from patients suffering from hemorrhagic strokes with the controls, revealed LDL as the risk factor contributing to the development of ICH whereas TG was reported as a protective factor. It could be concluded that LDL level can be considered as a risk factor for both ischemic and hemorrhagic cerebral events.

Expanding roles for lipid droplets

PubMed Central

Welte, Michael A.

2015-01-01

Summary Lipid droplets are the intracellular sites for neutral lipid storage. They are critical for lipid metabolism and energy homeostasis, and their dysfunction has been linked to many diseases. Accumulating evidence suggests that the roles lipid droplets play in biology are significantly broader than previously anticipated. Lipid droplets are the source of molecules important in the nucleus: they can sequester transcription factors and chromatin components and generate the lipid ligands for certain nuclear receptors. Lipid droplets have also emerged as important nodes for fatty acid trafficking, both inside the cell and between cells. In immunity, new roles for droplets, not directly linked to lipid metabolism, have been uncovered, as assembly platforms for specific viruses and as reservoirs for proteins that fight intracellular pathogens. Until recently, knowledge about droplets in the nervous system has been minimal, but now there are multiple links between lipid droplets and neurodegeneration: Many candidate genes for Hereditary Spastic Paraplegia also have central roles in lipid-droplet formation and maintenance, and mitochondrial dysfunction in neurons can lead to transient accumulating of lipid droplets in neighboring glial cells, an event that may, in turn, contribute to neuronal damage. As the cell biology and biochemistry of lipid droplets are increasingly well understood, the next few years should yield many new mechanistic insights into these novel functions of lipid droplets. PMID:26035793

Regulation of NF-κB-Induced Inflammatory Signaling by Lipid Peroxidation-Derived Aldehydes

PubMed Central

Yadav, Umesh C. S.; Ramana, Kota V.

2013-01-01

Oxidative stress plays a critical role in the pathophysiology of a wide range of diseases including cancer. This view has broadened significantly with the recent discoveries that reactive oxygen species initiated lipid peroxidation leads to the formation of potentially toxic lipid aldehyde species such as 4-hydroxy-trans-2-nonenal (HNE), acrolein, and malondialdehyde which activate various signaling intermediates that regulate cellular activity and dysfunction via a process called redox signaling. The lipid aldehyde species formed during synchronized enzymatic pathways result in the posttranslational modification of proteins and DNA leading to cytotoxicity and genotoxicty. Among the lipid aldehyde species, HNE has been widely accepted as a most toxic and abundant lipid aldehyde generated during lipid peroxidation. HNE and its glutathione conjugates have been shown to regulate redox-sensitive transcription factors such as NF-κB and AP-1 via signaling through various protein kinase cascades. Activation of redox-sensitive transcription factors and their nuclear localization leads to transcriptional induction of several genes responsible for cell survival, differentiation, and death. In this review, we describe the mechanisms by which the lipid aldehydes transduce activation of NF-κB signaling pathways that may help to develop therapeutic strategies for the prevention of a number of inflammatory diseases. PMID:23710287

Lipid, lipoproteins, C-reactive protein, and hemostatic factors at baseline in the diabetes prevention program.

PubMed

2005-10-01

Individuals with impaired glucose tolerance (IGT) appear to be at increased risk for cardiovascular disease (CVD) due at least in part to an increased prevalence of risk factors. We evaluated lipid, lipoprotein, C-reactive protein (CRP), fibrinogen, and tissue plasminogen activator (tPA) levels at study entry in the largest multiethnic cohort of participants with IGT described, namely in the Diabetes Prevention Program (DPP). Measurements were performed at the baseline visit of 3,819 randomized participants of the DPP. Among 3,622 participants who were not taking lipid-lowering medicines, cardiovascular risk factors were analyzed in relation to demographic, anthropometric, and metabolic measures. Major determinants of risk factors were assessed in multivariate analysis. Over 40% of participants had elevated triglyceride, LDL cholesterol, and CRP levels and reduced HDL cholesterol levels. Men had higher triglyceride and tPA and lower HDL cholesterol concentrations and smaller LDL particle size than women, whereas women had higher CRP and fibrinogen levels. African Americans had less dyslipidemia but higher fibrinogen levels, and Asian Americans had lower CRP and fibrinogen levels than Caucasians and Hispanics. The surrogate measure of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) had the strongest association with HDL cholesterol, triglyceride, and tPA levels and LDL particle size. BMI had the greatest influence on CRP and fibrinogen levels. Using median splits of indexes of insulin resistance and insulin secretion (insulin-to-glucose ratio), participants with greater insulin resistance had a more adverse CVD risk-factor profile, whereas insulin secretion had little influence on risk factors. The pattern of CVD risk factors in participants with IGT in the DPP exhibits substantial heterogeneity and is significantly influenced by race, sex, and age, as well as by obesity, glucose, and insulin measures. The degree of insulin

Acyl-Lipid Metabolism

PubMed Central

Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

2013-01-01

Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

Acyl-Lipid Metabolism

PubMed Central

Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

2010-01-01

Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:22303259

LipidPedia: a comprehensive lipid knowledgebase.

PubMed

Kuo, Tien-Chueh; Tseng, Yufeng Jane

2018-04-10

Lipids are divided into fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, sterols, prenol lipids and polyketides. Fatty acyls and glycerolipids are commonly used as energy storage, whereas glycerophospholipids, sphingolipids, sterols and saccharolipids are common used as components of cell membranes. Lipids in fatty acyls, glycerophospholipids, sphingolipids and sterols classes play important roles in signaling. Although more than 36 million lipids can be identified or computationally generated, no single lipid database provides comprehensive information on lipids. Furthermore, the complex systematic or common names of lipids make the discovery of related information challenging. Here, we present LipidPedia, a comprehensive lipid knowledgebase. The content of this database is derived from integrating annotation data with full-text mining of 3,923 lipids and more than 400,000 annotations of associated diseases, pathways, functions, and locations that are essential for interpreting lipid functions and mechanisms from over 1,400,000 scientific publications. Each lipid in LipidPedia also has its own entry containing a text summary curated from the most frequently cited diseases, pathways, genes, locations, functions, lipids and experimental models in the biomedical literature. LipidPedia aims to provide an overall synopsis of lipids to summarize lipid annotations and provide a detailed listing of references for understanding complex lipid functions and mechanisms. LipidPedia is available at http://lipidpedia.cmdm.tw. yjtseng@csie.ntu.edu.tw. Supplementary data are available at Bioinformatics online.

LipidMatch: an automated workflow for rule-based lipid identification using untargeted high-resolution tandem mass spectrometry data.

PubMed

Koelmel, Jeremy P; Kroeger, Nicholas M; Ulmer, Candice Z; Bowden, John A; Patterson, Rainey E; Cochran, Jason A; Beecher, Christopher W W; Garrett, Timothy J; Yost, Richard A

2017-07-10

Lipids are ubiquitous and serve numerous biological functions; thus lipids have been shown to have great potential as candidates for elucidating biomarkers and pathway perturbations associated with disease. Methods expanding coverage of the lipidome increase the likelihood of biomarker discovery and could lead to more comprehensive understanding of disease etiology. We introduce LipidMatch, an R-based tool for lipid identification for liquid chromatography tandem mass spectrometry workflows. LipidMatch currently has over 250,000 lipid species spanning 56 lipid types contained in in silico fragmentation libraries. Unique fragmentation libraries, compared to other open source software, include oxidized lipids, bile acids, sphingosines, and previously uncharacterized adducts, including ammoniated cardiolipins. LipidMatch uses rule-based identification. For each lipid type, the user can select which fragments must be observed for identification. Rule-based identification allows for correct annotation of lipids based on the fragments observed, unlike typical identification based solely on spectral similarity scores, where over-reporting structural details that are not conferred by fragmentation data is common. Another unique feature of LipidMatch is ranking lipid identifications for a given feature by the sum of fragment intensities. For each lipid candidate, the intensities of experimental fragments with exact mass matches to expected in silico fragments are summed. The lipid identifications with the greatest summed intensity using this ranking algorithm were comparable to other lipid identification software annotations, MS-DIAL and Greazy. For example, for features with identifications from all 3 software, 92% of LipidMatch identifications by fatty acyl constituents were corroborated by at least one other software in positive mode and 98% in negative ion mode. LipidMatch allows users to annotate lipids across a wide range of high resolution tandem mass spectrometry

Novel insights on interactions between folate and lipid metabolism

PubMed Central

da Silva, Robin P; Kelly, Karen B; Al Rajabi, Ala; Jacobs, René L

2014-01-01

Folate is an essential B vitamin required for the maintenance of AdoMet-dependent methylation. The liver is responsible for many methylation reactions that are used for post-translational modification of proteins, methylation of DNA, and the synthesis of hormones, creatine, carnitine, and phosphatidylcholine. Conditions where methylation capacity is compromised, including folate deficiency, are associated with impaired phosphatidylcholine synthesis resulting in non-alcoholic fatty liver disease and steatohepatitis. In addition, folate intake and folate status have been associated with changes in the expression of genes involved in lipid metabolism, obesity, and metabolic syndrome. In this review, we provide insight on the relationship between folate and lipid metabolism, and an outlook for the future of lipid-related folate research. © 2013 BioFactors, 40(3):277–283, 2014 PMID:24353111

Evidence for Lipid Packaging in the Crystal Structure of the GM2-Activator Complex with Platelet Activating Factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wright, Christine S.; Mi, Li-Zhi; Rastinejad, Fraydoon

2010-11-16

GM2-activator protein (GM2-AP) is a lipid transfer protein that has the ability to stimulate the enzymatic processing of gangliosides as well as T-cell activation through lipid presentation. Our previous X-ray crystallographic studies of GM2-AP have revealed a large lipid binding pocket as the central overall feature of the structure with non-protein electron density within this pocket suggesting bound lipid. To extend these studies, we present here the 2 {angstrom} crystal structure of GM2-AP complexed with platelet activating factor (PAF). PAF is a potent phosphoacylglycerol whose toxic patho-physiological effects can be inhibited by GM2-AP. The structure shows an ordered arrangement ofmore » two bound lipids and a fatty acid molecule. One PAF molecule binds in an extended conformation within the hydrophobic channel that has an open and closed conformation, and was seen to contain bound phospholipid in the low pH apo structure. The second molecule is submerged inside the pocket in a U-shaped conformation with its head group near the single polar residue S141. It was refined as lyso-PAF as it lacks electron density for the sn-2 acetate group. The alkyl chains of PAF interact through van der Waals contacts, while the head groups bind in different environments with their phosphocholine moieties in contact with aromatic rings (Y137, F80). The structure has revealed further insights into the lipid binding properties of GM2-AP, suggesting an unexpected unique mode of lipid packaging that may explain the efficiency of GM2-AP in inhibiting the detrimental biological effects of PAF.« less

LMSD: LIPID MAPS structure database

PubMed Central

Sud, Manish; Fahy, Eoin; Cotter, Dawn; Brown, Alex; Dennis, Edward A.; Glass, Christopher K.; Merrill, Alfred H.; Murphy, Robert C.; Raetz, Christian R. H.; Russell, David W.; Subramaniam, Shankar

2007-01-01

The LIPID MAPS Structure Database (LMSD) is a relational database encompassing structures and annotations of biologically relevant lipids. Structures of lipids in the database come from four sources: (i) LIPID MAPS Consortium's core laboratories and partners; (ii) lipids identified by LIPID MAPS experiments; (iii) computationally generated structures for appropriate lipid classes; (iv) biologically relevant lipids manually curated from LIPID BANK, LIPIDAT and other public sources. All the lipid structures in LMSD are drawn in a consistent fashion. In addition to a classification-based retrieval of lipids, users can search LMSD using either text-based or structure-based search options. The text-based search implementation supports data retrieval by any combination of these data fields: LIPID MAPS ID, systematic or common name, mass, formula, category, main class, and subclass data fields. The structure-based search, in conjunction with optional data fields, provides the capability to perform a substructure search or exact match for the structure drawn by the user. Search results, in addition to structure and annotations, also include relevant links to external databases. The LMSD is publicly available at PMID:17098933

Endoplasmic reticulum factor ERLIN2 regulates cytosolic lipid content in cancer cells

PubMed Central

Wang, Guohui; Zhang, Xuebao; Lee, Jin-Sook; Wang, Xiaogang; Yang, Zeng-Quan; Zhang, Kezhong

2013-01-01

Increased de novo lipogenesis is a hallmark of aggressive cancers. Lipid droplets, the major form of cytosolic lipid storage, have been implicated in cancer cell proliferation and tumorigenesis. Recently, we identified the ERLIN2 [ER (endoplasmic reticulum) lipid raft-associated 2) gene that is amplified and overexpressed in aggressive human breast cancer. Previous studies demonstrated that ERLIN2 plays a supporting oncogenic role by facilitating the transformation of human breast cancer cells. In the present study, we found that ERLIN2 supports cancer cell growth by regulating cytosolic lipid droplet production. ERLIN2 is preferably expressed in human breast cancer cells or hepatoma cells and is inducible by insulin signalling or when cells are cultured in lipoprotein-deficient medium. Increased expression of ERLIN2 promotes the accumulation of cytosolic lipid droplets in breast cancer cells or hepatoma cells in response to insulin or overload of unsaturated fatty acids. ERLIN2 regulates activation of SREBP (sterol regulatory element-binding protein) 1c, the key regulator of de novo lipogenesis, in cancer cells. ERLIN2 was found to bind to INSIG1 (insulin-induced gene 1), a key ER membrane protein that blocks SREBP activation. Consistent with the role of ERLIN2 in regulating cytosolic lipid content, down-regulation of ERLIN2 in breast cancer or hepatoma cells led to lower cell proliferation rates. The present study revealed a novel role for ERLIN2 in supporting cancer cell growth by promoting the activation of the key lipogenic regulator SREBP1c and the production of cytosolic lipid droplets. The identification of ERLIN2 as a regulator of cytosolic lipid content in cancer cells has important implications for understanding the molecular basis of tumorigenesis and the treatment of cancer. PMID:22690709

The Flexibility of Ectopic Lipids

PubMed Central

Loher, Hannah; Kreis, Roland; Boesch, Chris; Christ, Emanuel

2016-01-01

In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL), skeletal (intramyocellular lipids; IMCL) or cardiac muscle cells (intracardiomyocellular lipids; ICCL). Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS) is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass), insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term) appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations. PMID:27649157

The Flexibility of Ectopic Lipids.

PubMed

Loher, Hannah; Kreis, Roland; Boesch, Chris; Christ, Emanuel

2016-09-14

In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL), skeletal (intramyocellular lipids; IMCL) or cardiac muscle cells (intracardiomyocellular lipids; ICCL). Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. ¹H-magnetic resonance spectroscopy (¹H-MRS) is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass), insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term) appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.

Imbalanced Hemolymph Lipid Levels Affect Feeding Motivation in the Two-Spotted Cricket, Gryllus bimaculatus.

PubMed

Konuma, Takahiro; Tsukamoto, Yusuke; Nagasawa, Hiromichi; Nagata, Shinji

2016-01-01

Insect feeding behavior is regulated by many intrinsic factors, including hemolymph nutrient levels. Adipokinetic hormone (AKH) is a peptide factor that modulates hemolymph nutrient levels and regulates the nutritional state of insects by triggering the transfer of lipids into the hemolymph. We recently demonstrated that RNA interference (RNAi)-mediated knockdown of the AKH receptor (AKHR) reduces hemolymph lipid levels, causing an increase in the feeding frequency of the two-spotted cricket, Gryllus bimaculatus. This result indicated that reduced hemolymph lipid levels might motivate crickets to feed. In the present study, to elucidate whether hemolymph lipid levels contribute to insect feeding behavior, we attempted to manipulate hemolymph lipid levels via the lipophorin (Lp)-mediated lipid transferring system in G. bimaculatus. Of the constituent proteins in Lp, we focused on apolipophorin-III (GrybiApoLp-III) because of its possible role in facilitating lipid mobilization. First, we used RNAi to reduce the expression of GrybiApoLp-III. RNAi-mediated knockdown of GrybiApoLp-III had little effect on basal hemolymph lipid levels and the amount of food intake. In addition, hemolymph lipid levels remained static even after injecting AKH into GrybiApoLp-IIIRNAi crickets. These observations indicated that ApoLp-III does not maintain basal hemolymph lipid levels in crickets fed ad libitum, but is necessary for mobilizing lipid transfer into the hemolymph following AKH stimulation. Second, Lp (containing lipids) was injected into the hemolymph to induce a temporary increase in hemolymph lipid levels. Consequently, the initiation of feeding was delayed in a dose-dependent manner, indicating that increased hemolymph lipid levels reduced the motivation to feed. Taken together, these data validate the importance of basal hemolymph lipid levels in the control of energy homeostasis and for regulating feeding behavior in crickets.

Imbalanced Hemolymph Lipid Levels Affect Feeding Motivation in the Two-Spotted Cricket, Gryllus bimaculatus

PubMed Central

Konuma, Takahiro; Tsukamoto, Yusuke; Nagasawa, Hiromichi; Nagata, Shinji

2016-01-01

Insect feeding behavior is regulated by many intrinsic factors, including hemolymph nutrient levels. Adipokinetic hormone (AKH) is a peptide factor that modulates hemolymph nutrient levels and regulates the nutritional state of insects by triggering the transfer of lipids into the hemolymph. We recently demonstrated that RNA interference (RNAi)-mediated knockdown of the AKH receptor (AKHR) reduces hemolymph lipid levels, causing an increase in the feeding frequency of the two-spotted cricket, Gryllus bimaculatus. This result indicated that reduced hemolymph lipid levels might motivate crickets to feed. In the present study, to elucidate whether hemolymph lipid levels contribute to insect feeding behavior, we attempted to manipulate hemolymph lipid levels via the lipophorin (Lp)-mediated lipid transferring system in G. bimaculatus. Of the constituent proteins in Lp, we focused on apolipophorin-III (GrybiApoLp-III) because of its possible role in facilitating lipid mobilization. First, we used RNAi to reduce the expression of GrybiApoLp-III. RNAi-mediated knockdown of GrybiApoLp-III had little effect on basal hemolymph lipid levels and the amount of food intake. In addition, hemolymph lipid levels remained static even after injecting AKH into GrybiApoLp-IIIRNAi crickets. These observations indicated that ApoLp-III does not maintain basal hemolymph lipid levels in crickets fed ad libitum, but is necessary for mobilizing lipid transfer into the hemolymph following AKH stimulation. Second, Lp (containing lipids) was injected into the hemolymph to induce a temporary increase in hemolymph lipid levels. Consequently, the initiation of feeding was delayed in a dose-dependent manner, indicating that increased hemolymph lipid levels reduced the motivation to feed. Taken together, these data validate the importance of basal hemolymph lipid levels in the control of energy homeostasis and for regulating feeding behavior in crickets. PMID:27144650

High resolution microscopy of the lipid layer of the tear film.

PubMed

King-Smith, P Ewen; Nichols, Jason J; Braun, Richard J; Nichols, Kelly K

2011-10-01

Tear film evaporation is controlled by the lipid layer and is an important factor in dry eye conditions. Because the barrier to evaporation depends on the structure of the lipid layer, a high resolution microscope has been constructed to study the lipid layer in dry and in normal eyes. The microscope incorporates the following features. First, a long working distance microscope objective is used with a high numerical aperture and resolution. Second, because such a high resolution objective has limited depth of focus, 2000 images are recorded with a video camera over a 20-sec period, with the expectation that some images will be in focus. Third, illumination is from a stroboscopic light source having a brief flash duration, to avoid blurring from movement of the lipid layer. Fourth, the image is in focus when the edge of the image is sharp - this feature is used to select images in good focus. Fifth, an aid is included to help align the cornea at normal incidence to the axis of the objective so that the whole lipid image can be in focus. High resolution microscopy has the potential to elucidate several characteristics of the normal and abnormal lipid layer, including different objects and backgrounds, changes in the blink cycle, stability and fluidity, dewetting, gel-like properties and possible relation to lipid domains. It is expected that high resolution microscopy of the lipid layer will provide information about the mechanisms of dry eye disorders. Illustrative results are presented, derived from over 10,000 images from 375 subjects.

Effects of Bread with Nigella Sativa on Lipid Profiles, Apolipoproteins and Inflammatory Factor in Metabolic Syndrome Patients

PubMed Central

2016-01-01

Nigella sativa (N.sativa) has been used in traditional medicine and many studies have been performed in different communities in order to reveal the effects of it on medical disorders and chronic diseases. The aim of this study was to investigate the effects of bread with N. Sativa on lipid profiles, apolipoproteins, and inflammatory factors in metabolic syndrome (MetS) patients. A randomized, double-blind, cross-over and clinical trial was conducted in 51 MetS patients of both sexes with age group of 20-65 years old in Chaloos, north of Iran. Patients were randomly divided in two groups. In phase 1, intervention group (A, n = 27) received daily a bread with N. sativa and wheat bran and control group (B, n = 24) received the same bread without N. sativa for 2 months. After 2 weeks of wash out period, phase 2 was started with switch the intervention between two groups. Measuring of lipid profiles, apolipoproteins and inflammatory factor was performed for all patients before and after two phases. In this study, treatment, sequence and time effects of intervention were evaluated and revealed that consumption of bread with N. sativa has no significant treatment and time effects on triglyceride (TG), cholesterol (CHOL), low density lipoprotein (LDL), high density lipoprotein (HDL), apolipoprotein (APO)-A, APO-B and high-sensitivity C-reactive protein (p > 0.05). Sequence effect was significant on CHOL, LDL, APO-A, and APO-B (p < 0.05) but was not significant on other parameters (p > 0.05). Consumption of bread with N. sativa has no a significant effect on lipid profiles, apolipoproteins and inflammatory factor in MetS patients. PMID:27152298

Nutrients and neurodevelopment: lipids.

PubMed

González, Horacio F; Visentin, Silvana

2016-10-01

Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding. Sociedad Argentina de Pediatría.

Serum lipid alterations in GBA-associated Parkinson's disease.

PubMed

Guedes, Leonor Correia; Chan, Robin Barry; Gomes, Marcos António; Conceição, Vasco A; Machado, Raquel Bouça; Soares, Tiago; Xu, Yimeng; Gaspar, Paulo; Carriço, Joao André; Alcalay, Roy N; Ferreira, Joaquim J; Outeiro, Tiago Fleming; Miltenberger-Miltenyi, Gabriel

2017-11-01

Mutations in the GBA gene, encoding for the lysosomal enzyme glucocerebrosidase, are associated with Gaucher disease. Alterations in plasma sphingolipids have been reported in Gaucher, and similarly in brain extracts in Lewy body disease. As GBA mutations are prevalent risk factors for Parkinson's disease and overlap of molecular pathways are presumable, here we assessed the lipid profiles in Parkinson's patients with and without GBA mutations. We sequenced all GBA exons in 415 Parkinson's patients, previously genotyped for LRRK2. 64 patients (29 GBA positive vs. 35 non-GBA-carriers including 18 LRRK2 positive and 17 non-mutated) were analyzed for chitotriosidase activity and for the concentration of 40 lipid classes using HPLC-MS. 29/415 patients (6.9%) carried 8 different GBA mutations associated with Gaucher or Parkinson's, including one novel mutation. Chitotriosidase activity was similar across the genetic groups, while the levels of key lipids were altered in GBA mutation carriers: Monohexosylceramide, Ceramide and Sphingomyelin were elevated; while Phosphatidic acid (PA), Phosphatidylethanolamine (PE), Plasmalogen phosphatidylethanolamine (PEp) and Acyl Phosphatidylglycerol (AcylPG) were decreased. The results suggest an important role for these lipids in GBA mediated Parkinson's disease and assist in the identification of common pathways between Gaucher and Parkinson's. Ultimately, our findings may lead to the identification of novel biomarkers for individuals at increased risk of developing Parkinson's disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of Factors Associated With the Tear Film Lipid Layer Thickness in Normal Eyes and Patients With Dry Eye Syndrome.

PubMed

Jung, Ji Won; Park, Si Yoon; Kim, Jin Sun; Kim, Eung Kweon; Seo, Kyoung Yul; Kim, Tae-Im

2016-08-01

To determine the effects of clinical variables, including age, sex, history of refractive or cataract surgery, contact lens use, and ocular surface and meibomian gland parameters on the lipid layer thickness (LLT) in normal subjects and patients with dry eye syndrome (DES). A total of 64 normal subjects and 326 patients with DES were enrolled, and they underwent measurements of LLT with a LipiView interferometer and tear meniscus height using optical coherence tomography, tear film break-up time (TBUT) determination, ocular surface staining, Schirmer's test, examination of the lid margins and meibomian glands, and assessment using the Ocular Surface Disease Index (OSDI). In normal subjects, the median (range) LLT was 67 (33-100) nm, and age was the only factor that was significantly associated with LLT (β = 0.678, P = 0.028). In patients with DES, the median (range) LLT was 84 (20-100) nm, and 79.0% of the participants fulfilled the diagnostic criteria for meibomian gland dysfunction (MGD). In a multivariate analysis, increased age and female sex were significantly related to increased LLT (β = 0.282, P = 0.005 and β = 11.493, P < 0.001), and hypersecretory MGD and lid margin inflammation were independently associated with increased LLT (β = 11.299, P = 0.001 and β = 12.747, P = 0.001). Lipid layer thickness measurements using a new interferometer are significantly affected by demographic factors such as age, sex, ocular surgical history, and MGD type. Therefore, all of these factors must be considered in the diagnosis of ocular surface diseases.

Lipid profiling in sewage sludge.

PubMed

Zhu, Fenfen; Wu, Xuemin; Zhao, Luyao; Liu, Xiaohui; Qi, Juanjuan; Wang, Xueying; Wang, Jiawei

2017-06-01

High value-added reutilization of sewage sludge from wastewater treatment plants (WWTPs) is essential in sustainable development in WWTPs. However, despite the advantage of high value reutilization, this process must be based on a detailed study of organics in sludge. We used the methods employed in life sciences to determine the profile of lipids (cellular lipids, free fatty acids (FFAs), and wax/gum) in five sludge samples obtained from three typical WWTPs in Beijing; these samples include one sludge sample from a primary sedimentation tank, two activated sludge samples from two Anaerobic-Anoxic-Oxic (A2/O) tanks, and two activated sludge samples from two membrane bioreactor tanks. The percentage of total raw lipids varied from 2.90% to 12.3%. Sludge from the primary sedimentation tank showed the highest concentrations of lipid, FFA, and wax/gum and the second highest concentration of cellular lipids. All activated sludge contained an abundance of cellular lipids (>54%). Cells in sludge can from plants, animals, microbes and so on in wastewater. Approximately 14 species of cellular lipids were identified, including considerable high value-potential ceramide (9567-38774 mg/kg), coenzyme (937-3897 mg/kg), and some phosphatidylcholine (75-548 mg/kg). The presence of those lipid constituents would thus require a wider range of recovery methods for sludge. Both cellular lipids and FFAs contain an abundance of C16-C18 lipids at high saturation level, and they serve as good resources for biodiesel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plasma membrane lipids and their role in fungal virulence.

PubMed

Rella, Antonella; Farnoud, Amir M; Del Poeta, Maurizio

2016-01-01

There has been considerable evidence in recent years suggesting that plasma membrane lipids are important regulators of fungal pathogenicity. Various glycolipids have been shown to impart virulent properties in several fungal species, while others have been shown to play a role in host defense. In addition to their role as virulence factors, lipids also contribute to other virulence mechanisms such as drug resistance, biofilm formation, and release of extracellular vesicles. In addition, lipids also affect the mechanical properties of the plasma membrane through the formation of packed microdomains composed mainly of sphingolipids and sterols. Changes in the composition of lipid microdomains have been shown to disrupt the localization of virulence factors and affect fungal pathogenicity. This review gathers evidence on the various roles of plasma membrane lipids in fungal virulence and how lipids might contribute to the different processes that occur during infection and treatment. Insight into the role of lipids in fungal virulence can lead to an improved understanding of the process of fungal pathogenesis and the development of new lipid-mediated therapeutic strategies. Published by Elsevier Ltd.

Changes over time in risk factors for cardiovascular disease and use of lipid-lowering drugs in HIV-infected individuals and impact on myocardial infarction.

PubMed

Sabin, C A; d'Arminio Monforte, A; Friis-Moller, N; Weber, R; El-Sadr, W M; Reiss, P; Kirk, O; Mercie, P; Law, M G; De Wit, S; Pradier, C; Phillips, A N; Lundgren, J D

2008-04-01

Because of the known relationship between exposure to combination antiretroviral therapy and cardiovascular disease (CVD), it has become increasingly important to intervene against risk of CVD in human immunodeficiency virus (HIV)-infected patients. We evaluated changes in risk factors for CVD and the use of lipid-lowering therapy in HIV-infected individuals and assessed the impact of any changes on the incidence of myocardial infarction. The Data Collection on Adverse Events of Anti-HIV Drugs Study is a collaboration of 11 cohorts of HIV-infected patients that included follow-up for 33,389 HIV-infected patients from December 1999 through February 2006. The proportion of patients at high risk of CVD increased from 35.3% during 1999-2000 to 41.3% during 2005-2006. Of 28,985 patients, 2801 (9.7%) initiated lipid-lowering therapy; initiation of lipid-lowering therapy was more common for those with abnormal lipid values and those with traditional risk factors for CVD (male sex, older age, higher body mass index [calculated as the weight in kilograms divided by the square of the height in meters], family and personal history of CVD, and diabetes mellitus). After controlling for these, use of lipid-lowering drugs became relatively less common over time. The incidence of myocardial infarction (0.32 cases per 100 person-years [PY]; 95% confidence interval [CI], 0.29-0.35 cases per 100 PY) appeared to remain stable. However, after controlling for changes in risk factors for CVD, the rate decreased over time (relative rate in 2003 [compared with 1999-2000], 0.73 cases per 100 PY [95% CI, 0.50-1.05 cases per 100 PY]; in 2004, 0.64 cases per 100 PY [95% CI, 0.44-0.94 cases per 100 PY]; in 2005-2006, 0.36 cases per 100 PY [95% CI, 0.24-0.56 cases per 100 PY]). Further adjustment for lipid levels attenuated the relative rates towards unity (relative rate in 2003 [compared with 1999-2000], 1.06 cases per 100 PY [95% CI, 0.63-1.77 cases per 100 PY]; in 2004, 1.02 cases per 100 PY

Lipids in the cell: organisation regulates function.

PubMed

Santos, Ana L; Preta, Giulio

2018-06-01

Lipids are fundamental building blocks of all cells and play important roles in the pathogenesis of different diseases, including inflammation, autoimmune disease, cancer, and neurodegeneration. The lipid composition of different organelles can vary substantially from cell to cell, but increasing evidence demonstrates that lipids become organised specifically in each compartment, and this organisation is essential for regulating cell function. For example, lipid microdomains in the plasma membrane, known as lipid rafts, are platforms for concentrating protein receptors and can influence intra-cellular signalling. Lipid organisation is tightly regulated and can be observed across different model organisms, including bacteria, yeast, Drosophila, and Caenorhabditis elegans, suggesting that lipid organisation is evolutionarily conserved. In this review, we summarise the importance and function of specific lipid domains in main cellular organelles and discuss recent advances that investigate how these specific and highly regulated structures contribute to diverse biological processes.

Insulin-like Growth Factor I Reduces Lipid Oxidation and Foam Cell Formation via Downregulation of 12/15-lipoxygenase

PubMed Central

Sukhanov, Sergiy; Snarski, Patricia; Vaughn, Charlotte; Lobelle-Rich, Patricia; Kim, Catherine; Higashi, Yusuke; Shai, Shaw-Yung; Delafontaine, Patrice

2014-01-01

Objective We have shown that insulin-like growth factor I (IGF-1) infusion in Apoe−/− mice decreased atherosclerotic plaque size and plaque macrophage and lipid content suggesting that IGF-1 suppressed formation of macrophage-derived foam cells. Since 12/15-lipoxygenase (12/15-LOX) plays an important role in OxLDL and foam cell formation, we hypothesized that IGF-1 downregulates 12/15-LOX, thereby suppressing lipid oxidation and foam cell formation. Approach and Results We found that IGF-1 decreased 12/15-LOX plaque immunopositivity and serum OxLDL levels in Apoe−/− mice. IGF-1 reduced 12/15-LOX protein and mRNA levels in cultured THP-1 macrophages and IGF-1 also decreased expression of STAT6 transcription factor. IGF-1 reduction in macrophage 12/15-LOX was mediated in part via a PI3 kinase- and STAT6-dependent transcriptional mechanism. IGF-1 suppressed THP-1 macrophage ability to oxidize lipids and form foam cells. IGF-1 downregulated 12/15-LOX in human blood-derived primary macrophages and IGF-1 decreased LDL oxidation induced by these cells. IGF-1 reduced LDL oxidation and formation of foam cells by wild type murine peritoneal macrophages, however these effects were completely blocked in 12/15-LOX-null macrophages suggesting that the ability of IGF-1 to reduce LDL oxidation and foam cells formation is dependent on its ability to downregulate 12/15-LOX. Conclusions Overall our data demonstrate that IGF-1 reduces lipid oxidation and foam cell formation via downregulation of 12/15-LOX and this mechanism may play a major role in the anti-atherosclerotic effects of IGF-1. PMID:25549319

Insulin-like growth factor I reduces lipid oxidation and foam cell formation via downregulation of 12/15-lipoxygenase.

PubMed

Sukhanov, Sergiy; Snarski, Patricia; Vaughn, Charlotte; Lobelle-Rich, Patricia; Kim, Catherine; Higashi, Yusuke; Shai, Shaw-Yung; Delafontaine, Patrice

2015-02-01

We have shown that insulin-like growth factor I (IGF-1) infusion in Apoe(-/-) mice decreased atherosclerotic plaque size and plaque macrophage and lipid content suggesting that IGF-1 suppressed formation of macrophage-derived foam cells. Since 12/15-lipoxygenase (12/15-LOX) plays an important role in OxLDL and foam cell formation, we hypothesized that IGF-1 downregulates 12/15-LOX, thereby suppressing lipid oxidation and foam cell formation. We found that IGF-1 decreased 12/15-LOX plaque immunopositivity and serum OxLDL levels in Apoe(-/-) mice. IGF-1 reduced 12/15-LOX protein and mRNA levels in cultured THP-1 macrophages and IGF-1 also decreased expression of STAT6 transcription factor. IGF-1 reduction in macrophage 12/15-LOX was mediated in part via a PI3 kinase- and STAT6-dependent transcriptional mechanism. IGF-1 suppressed THP-1 macrophage ability to oxidize lipids and form foam cells. IGF-1 downregulated 12/15-LOX in human blood-derived primary macrophages and IGF-1 decreased LDL oxidation induced by these cells. IGF-1 reduced LDL oxidation and formation of foam cells by wild type murine peritoneal macrophages, however these effects were completely blocked in 12/15-LOX-null macrophages suggesting that the ability of IGF-1 to reduce LDL oxidation and foam cells formation is dependent on its ability to downregulate 12/15-LOX. Overall our data demonstrate that IGF-1 reduces lipid oxidation and foam cell formation via downregulation of 12/15-LOX and this mechanism may play a major role in the anti-atherosclerotic effects of IGF-1. Published by Elsevier Ireland Ltd.

Lipid, Lipoproteins, C-Reactive Protein, and Hemostatic Factors at Baseline in the Diabetes Prevention Program

PubMed Central

2005-01-01

OBJECTIVE — Individuals with impaired glucose tolerance (IGT) appear to be at increased risk for cardiovascular disease (CVD) due at least in part to an increased prevalence of risk factors. We evaluated lipid, lipoprotein, C-reactive protein (CRP), fibrinogen, and tissue plasminogen activator (tPA) levels at study entry in the largest multiethnic cohort of participants with IGT described, namely in the Diabetes Prevention Program (DPP). RESEARCH DESIGN AND METHODS — Measurements were performed at the baseline visit of 3,819 randomized participants of the DPP. Among 3,622 participants who were not taking lipid-lowering medicines, cardiovascular risk factors were analyzed in relation to demographic, anthropometric, and metabolic measures. Major determinants of risk factors were assessed in multivariate analysis. RESULTS — Over 40% of participants had elevated triglyceride, LDL cholesterol, and CRP levels and reduced HDL cholesterol levels. Men had higher triglyceride and tPA and lower HDL cholesterol concentrations and smaller LDL particle size than women, whereas women had higher CRP and fibrinogen levels. African Americans had less dyslipidemia but higher fibrinogen levels, and Asian Americans had lower CRP and fibrinogen levels than Caucasians and Hispanics. The surrogate measure of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) had the strongest association with HDL cholesterol, triglyceride, and tPA levels and LDL particle size. BMI had the greatest influence on CRP and fibrinogen levels. Using median splits of indexes of insulin resistance and insulin secretion (insulin-to-glucose ratio), participants with greater insulin resistance had a more adverse CVD risk-factor profile, whereas insulin secretion had little influence on risk factors. CONCLUSIONS — The pattern of CVD risk factors in participants with IGT in the DPP exhibits substantial heterogeneity and is significantly influenced by race, sex, and age, as well as

Integral lipids of mammalian hair.

PubMed

Wertz, P W; Downing, D T

1989-01-01

1. It has been demonstrated that hair contains lipids which cannot be removed by extensive extraction with chloroform-methanol mixtures. These integral lipids can be extracted only after the hair has been subjected to alkaline hydrolysis. 2. Integral hair lipids include cholesterol sulfate (0.7-2.9 mg/g hair), ceramides (0.6-1.4 mg/g), cholesterol (0.3-1.4 mg/g), fatty alcohols (trace-0.2 mg/g) and fatty acids (2.3-4.0 mg/g). 3. One of the major integral hair lipids, representing 38.4-47.6% of the total fatty acids, is the anteisobranched 18-methyleicosanoic acid. 4. The species examined included human (Homo sapiens), pig (Sus scrofa), dog (Canis familiaris), sheep (Ovis ammon aries) and cow (Bos taurus).

Blood lipid levels in a rural male population.

PubMed

Thelin, A; Stiernström, E L; Holmberg, S

2001-06-01

Farmers have a low risk for cardiovascular disease, which may be related to a favourable blood lipid profile. In order to study the blood lipid levels and evaluate the effect of other cardiovascular risk factors on the blood lipid profile, this cross-sectional study was made. A total of 1013 farmers and 769 non-farming rural men in nine different Swedish counties were examined, interviewed, and replied to questionnaires. The inter-relationships between different risk factors were analysed using a multivariate linear regression model. The farmers had a significantly more favourable blood lipid profile than the non-farmers although the total cholesterol levels were almost the same for the two groups. In the total study population there were significant positive relationships between total cholesterol level and body mass index (BMI), diastolic blood pressure and smoking. The high-density lipoprotein (HDL) level was positively related to physical workload and alcohol consumption, and negatively related to BMI, waist/hip ratio and smoking. Triglyceride levels showed a positive relationship to BMI, waist/hip ratio and blood pressure. Differences between farmers and other rural males were seen, especially with respect to the effect of physical activity and psychosocial factors. Among the farmers, a negative correlation between the Karasek-Theorell authority over work index and total cholesterol, the low-density lipoprotein (LDL)/HDL ratio and triglyceride levels was observed. This study indicated that diet is of minor significance for the blood lipid profile, whereas factors such as physical activity, body weight and the waist/hip ratio, smoking, alcohol consumption, and perhaps psychosocial working conditions are major independent factors affecting the blood lipid profile most prominently among farmers, but also among non-farming rural men.

Effect of neurosteroids on a model lipid bilayer including cholesterol: An Atomic Force Microscopy study.

PubMed

Sacchi, Mattia; Balleza, Daniel; Vena, Giulia; Puia, Giulia; Facci, Paolo; Alessandrini, Andrea

2015-05-01

Amphiphilic molecules which have a biological effect on specific membrane proteins, could also affect lipid bilayer properties possibly resulting in a modulation of the overall membrane behavior. In light of this consideration, it is important to study the possible effects of amphiphilic molecule of pharmacological interest on model systems which recapitulate some of the main properties of the biological plasma membranes. In this work we studied the effect of a neurosteroid, Allopregnanolone (3α,5α-tetrahydroprogesterone or Allo), on a model bilayer composed by the ternary lipid mixture DOPC/bSM/chol. We chose ternary mixtures which present, at room temperature, a phase coexistence of liquid ordered (Lo) and liquid disordered (Ld) domains and which reside near to a critical point. We found that Allo, which is able to strongly partition in the lipid bilayer, induces a marked increase in the bilayer area and modifies the relative proportion of the two phases favoring the Ld phase. We also found that the neurosteroid shifts the miscibility temperature to higher values in a way similarly to what happens when the cholesterol concentration is decreased. Interestingly, an isoform of Allo, isoAllopregnanolone (3β,5α-tetrahydroprogesterone or isoAllo), known to inhibit the effects of Allo on GABAA receptors, has an opposite effect on the bilayer properties. Copyright © 2015 Elsevier B.V. All rights reserved.

Retinal lipid and glucose metabolism dictates angiogenesis through the lipid sensor Ffar1.

PubMed

Joyal, Jean-Sébastien; Sun, Ye; Gantner, Marin L; Shao, Zhuo; Evans, Lucy P; Saba, Nicholas; Fredrick, Thomas; Burnim, Samuel; Kim, Jin Sung; Patel, Gauri; Juan, Aimee M; Hurst, Christian G; Hatton, Colman J; Cui, Zhenghao; Pierce, Kerry A; Bherer, Patrick; Aguilar, Edith; Powner, Michael B; Vevis, Kristis; Boisvert, Michel; Fu, Zhongjie; Levy, Emile; Fruttiger, Marcus; Packard, Alan; Rezende, Flavio A; Maranda, Bruno; Sapieha, Przemyslaw; Chen, Jing; Friedlander, Martin; Clish, Clary B; Smith, Lois E H

2016-04-01

Tissues with high metabolic rates often use lipids, as well as glucose, for energy, conferring a survival advantage during feast and famine. Current dogma suggests that high-energy-consuming photoreceptors depend on glucose. Here we show that the retina also uses fatty acid β-oxidation for energy. Moreover, we identify a lipid sensor, free fatty acid receptor 1 (Ffar1), that curbs glucose uptake when fatty acids are available. Very-low-density lipoprotein receptor (Vldlr), which is present in photoreceptors and is expressed in other tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived fatty acid. In the retinas of Vldlr(-/-) mice with low fatty acid uptake but high circulating lipid levels, we found that Ffar1 suppresses expression of the glucose transporter Glut1. Impaired glucose entry into photoreceptors results in a dual (lipid and glucose) fuel shortage and a reduction in the levels of the Krebs cycle intermediate α-ketoglutarate (α-KG). Low α-KG levels promotes stabilization of hypoxia-induced factor 1a (Hif1a) and secretion of vascular endothelial growth factor A (Vegfa) by starved Vldlr(-/-) photoreceptors, leading to neovascularization. The aberrant vessels in the Vldlr(-/-) retinas, which invade normally avascular photoreceptors, are reminiscent of the vascular defects in retinal angiomatous proliferation, a subset of neovascular age-related macular degeneration (AMD), which is associated with high vitreous VEGFA levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in macular telangiectasia, neovascular AMD and other retinal diseases.

Synthesis of Lipidated Proteins.

PubMed

Mejuch, Tom; Waldmann, Herbert

2016-08-17

Protein lipidation is one of the major post-translational modifications (PTM) of proteins. The attachment of the lipid moiety frequently determines the localization and the function of the lipoproteins. Lipidated proteins participate in many essential biological processes in eukaryotic cells, including vesicular trafficking, signal transduction, and regulation of the immune response. Malfunction of these cellular processes usually leads to various diseases such as cancer. Understanding the mechanism of cellular signaling and identifying the protein-protein and protein-lipid interactions in which the lipoproteins are involved is a crucial task. To achieve these goals, fully functional lipidated proteins are required. However, access to lipoproteins by means of standard expression is often rather limited. Therefore, semisynthetic methods, involving the synthesis of lipidated peptides and their subsequent chemoselective ligation to yield full-length lipoproteins, were developed. In this Review we summarize the commonly used methods for lipoprotein synthesis and the development of the corresponding chemoselective ligation techniques. Several key studies involving full-length semisynthetic lipidated Ras, Rheb, and LC3 proteins are presented.

Large-scale dialysis of sample lipids

USGS Publications Warehouse

Meadows, Jill; Tillitt, Donald E.; Huckins, James; Schroeder, D.

1993-01-01

The use of a semipermeable membrane device (SPMD) for dialysis in an organic solvent phase is an efficient alternative approach to separation of contaminants from large amounts of lipid (up to 50 grams or more) prior to organic chemical analysis. Passive separation of contaminants can be accomplished with a minimum of equipment and a comparatively small volume of solvent. This study examines the effects of factors such as dialytic solvent, lipid type, dialytic solvent:lipid volume ratio, dialysis time, and temperature on the performance of polyethylene SPMDs during lipid-contaminant separations. The experimental conditions for maximal recoveries of organochlorine pesticides and polychlorinated biphenyls with minimal lipid carryover are determined for the examined variables. When the dialytic procedure is optimized, very satisfactory and highly reproducible analyte recoveries can be obtained in a few days while separating > 90% of the lipid material in a single operation.

Solid-state fermentation of Mortierella isabellina for lipid production from soybean hull.

PubMed

Zhang, Jianguo; Hu, Bo

2012-02-01

Soybean hull, generated from soybean processing, is a lignocellulosic material with limited industrial applications and little market value. This research is exploring a new application of soybean hull to be converted to fungal lipids for biodiesel production through solid-state fermentation. Mortierella isabellina was selected as the oil producer because of its high lipid content at low C/N ratio. Several cultivation factors were investigated, including moisture content, inoculums size, fungal spore age, and nutrient supplements, in an attempt to enhance the lipid production of the solid-state fermentation process. The results showed that lipid production with the increase of the moisture content and the spore age, while decreased as the size of inoculums increased. Nutrients addition (KH₂PO₄ 1.2 mg and MgSO₄ 0.6 mg/g soybean hull) improved the lipid production. The total final lipid reached 47.9 mg lipid from 1 g soybean hull after the conversion, 3.3-fold higher than initial lipid reserve in the soybean hull. The fatty acid profile analysis indicated that fatty acid content consisted of 30.0% of total lipid, and 80.4% of total fatty acid was C16 and C18. Therefore, lipid production from soybean hull is a possible option to enable soybean hull as a new resource for biodiesel production and to enhance the overall oil production from soybeans.

DNA release from lipoplexes by anionic lipids: correlation with lipid mesomorphism, interfacial curvature, and membrane fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarahovsky, Yury S.; Koynova, Rumiana; MacDonald, Robert C.

2010-01-18

DNA release from lipoplexes is an essential step during lipofection and is probably a result of charge neutralization by cellular anionic lipids. As a model system to test this possibility, fluorescence resonance energy transfer between DNA and lipid covalently labeled with Cy3 and BODIPY, respectively, was used to monitor the release of DNA from lipid surfaces induced by anionic liposomes. The separation of DNA from lipid measured this way was considerably slower and less complete than that estimated with noncovalently labeled DNA, and depends on the lipid composition of both lipoplexes and anionic liposomes. This result was confirmed by centrifugalmore » separation of released DNA and lipid. X-ray diffraction revealed a clear correlation of the DNA release capacity of the anionic lipids with the interfacial curvature of the mesomorphic structures developed when the anionic and cationic liposomes were mixed. DNA release also correlated with the rate of fusion of anionic liposomes with lipoplexes. It is concluded that the tendency to fuse and the phase preference of the mixed lipid membranes are key factors for the rate and extent of DNA release. The approach presented emphasizes the importance of the lipid composition of both lipoplexes and target membranes and suggests optimal transfection may be obtained by tailoring lipoplex composition to the lipid composition of target cells.« less

Lipid Synthesis in Protozoan Parasites: a Comparison Between Kinetoplastids and Apicomplexans

PubMed Central

Ramakrishnan, Srinivasan; Serricchio, Mauro; Striepen, Boris; Bütikofer, Peter

2013-01-01

Lipid metabolism is of crucial importance for pathogens. Lipids serve as cellular building blocks, signalling molecules, energy stores, posttranslational modifiers, and pathogenesis factors. Parasites rely on a complex system of uptake and synthesis mechanisms to satisfy their lipid needs. The parameters of this system change dramatically as the parasite transits through the various stages of its life cycle. Here we discuss the tremendous recent advances that have been made in the understanding of the synthesis and uptake pathways for fatty acids and phospholipids in apicomplexan and kinetoplastid parasites, including Plasmodium, Toxoplasma, Cryptosporidium, Trypanosoma and Leishmania. Lipid synthesis differs in significant ways between parasites from both phyla and the human host. Parasites have acquired novel pathways through endosymbiosis, as in the case of the apicoplast, have dramatically reshaped substrate and product profiles, and have evolved specialized lipids to interact with or manipulate the host. These differences potentially provide opportunities for drug development. We outline the lipid pathways for key species in detail as they progress through the developmental cycle and highlight those that are of particular importance to the biology of the pathogens and/or are the most promising targets for parasite-specific treatment. PMID:23827884

Association of lipid metabolism with ovarian cancer.

PubMed

Tania, M; Khan, M A; Song, Y

2010-10-01

Defects in lipid metabolism have been found to be linked to several diseases, among which atherosclerosis, hypertension, obesity, and diabetes are the most important. Although cancer is chiefly a genetic disease, dietary lipid intake and metabolism are related to some cancer risks, including the risk for ovarian cancer. Higher intake of dietary lipids, systemic lipid metabolism malfunction, and abnormal serum lipid levels are somehow related to ovarian cancer. Overexpression of some lipid metabolic enzymes are also found in ovarian cancer. In this review article, we summarize the relationships between lipid intake, lipid metabolism, and ovarian cancer.

Association of lipid metabolism with ovarian cancer

PubMed Central

Tania, M.; Khan, M.A.; Song, Y.

2010-01-01

Defects in lipid metabolism have been found to be linked to several diseases, among which atherosclerosis, hypertension, obesity, and diabetes are the most important. Although cancer is chiefly a genetic disease, dietary lipid intake and metabolism are related to some cancer risks, including the risk for ovarian cancer. Higher intake of dietary lipids, systemic lipid metabolism malfunction, and abnormal serum lipid levels are somehow related to ovarian cancer. Overexpression of some lipid metabolic enzymes are also found in ovarian cancer. In this review article, we summarize the relationships between lipid intake, lipid metabolism, and ovarian cancer. PMID:20975872

Interdigitation between Triglycerides and Lipids Modulates Surface Properties of Lipid Droplets.

PubMed

Bacle, Amélie; Gautier, Romain; Jackson, Catherine L; Fuchs, Patrick F J; Vanni, Stefano

2017-04-11

Intracellular lipid droplets (LDs) are the main cellular site of metabolic energy storage. Their structure is unique inside the cell, with a core of esterified fatty acids and sterols, mainly triglycerides and sterol esters, surrounded by a single monolayer of phospholipids. Numerous peripheral proteins, including several that were previously associated with intracellular compartments surrounded by a lipid bilayer, have been recently shown to target the surface of LDs, but how they are able to selectively target this organelle remains largely unknown. Here, we use atomistic and coarse-grained molecular dynamics simulations to investigate the molecular properties of the LD surface and to characterize how it differs from that of a lipid bilayer. Our data suggest that although several surface properties are remarkably similar between the two structures, key differences originate from the interdigitation between surface phospholipids and core neutral lipids that occurs in LDs. This property is extremely sensitive to membrane undulations, unlike in lipid bilayers, and it strongly affects both lipid-packing defects and the lateral pressure profile. We observed a marked change in overall surface properties for surface tensions >10 mN/m, indicative of a bimodal behavior. Our simulations provide a comprehensive molecular characterization of the unique surface properties of LDs and suggest how the molecular properties of the surface lipid monolayer can be modulated by the underlying neutral lipids. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Role of Fatty Acid Kinase in Cellular Lipid Homeostasis and SaeRS-Dependent Virulence Factor Expression in Staphylococcus aureus.

PubMed

Ericson, Megan E; Subramanian, Chitra; Frank, Matthew W; Rock, Charles O

2017-08-01

The SaeRS two-component system is a master activator of virulence factor transcription in Staphylococcus aureus , but the cellular factors that control its activity are unknown. Fatty acid (FA) kinase is a two-component enzyme system required for extracellular FA uptake and SaeRS activity. Here, we demonstrate the existence of an intracellular nonesterified FA pool in S. aureus that is elevated in strains lacking FA kinase activity. SaeRS-mediated transcription is restored in FA kinase-negative strains when the intracellular FA pool is reduced either by growth with FA-depleted bovine serum albumin to extract the FA into the medium or by the heterologous expression of Neisseria gonorrhoeae acyl-acyl carrier protein synthetase to activate FA for phospholipid synthesis. These data show that FAs act as negative regulators of SaeRS signaling, and FA kinase activates SaeRS-dependent virulence factor production by lowering inhibitory FA levels. Thus, FA kinase plays a role in cellular lipid homeostasis by activating FA for incorporation into phospholipid, and it indirectly regulates SaeRS signaling by maintaining a low intracellular FA pool. IMPORTANCE The SaeRS two-component system is a master transcriptional activator of virulence factor production in response to the host environment in S. aureus , and strains lacking FA kinase have severely attenuated SaeRS-dependent virulence factor transcription. FA kinase is required for the activation of exogenous FAs, and it plays a role in cellular lipid homeostasis by recycling cellular FAs into the phospholipid biosynthetic pathway. Activation of the sensor kinase, SaeS, is mediated by its membrane anchor domain, and the FAs which accumulate in FA kinase knockout strains are potent inhibitors of SaeS-dependent signaling. This work identifies FAs as physiological effectors for the SaeRS system and reveals a connection between cellular lipid homeostasis and the regulation of virulence factor transcription. FA kinase is widely

Associations between lipid metabolism and fertility in the dairy cow.

PubMed

Wathes, D Claire; Clempson, Andrew M; Pollott, Geoff E

2012-01-01

Dairy cows mobilise body tissues to support milk production and, because glucose supplies are limited, lipids are used preferentially for energy production. Lipogenic activity is switched off and lipolytic mechanisms in adipose tissue increase through changes in the expression of several key enzymes. This results in a loss of body condition, together with high circulating concentrations of non-esterified fatty acids. Changes in the synthesis, secretion and signalling pathways of somatotrophic hormones (insulin, growth hormone, insulin-like growth factor 1) and adipokines (e.g. leptin) are central to the regulation of these processes. A high reliance on fatty acids as an energy source in the peripartum period causes oxidative damage to mitochondria in metabolically active tissues, including the liver and reproductive tract. The expression of genes involved in insulin resistance (PDK4, AHSG) is increased, together with expression of TIEG1, a transcription factor that can induce apoptosis via the mitochondrial pathway. Polymorphisms in TFAM and UCP2, two autosomal mitochondrial genes, have been associated with longevity in dairy cows. Polymorphisms in many other genes that affect lipid metabolism also show some associations with fertility traits. These include DGAT1, SCD1, DECR1, CRH, CBFA2T1, GH, LEP and NPY. Excess lipid accumulation in oocytes and the regenerating endometrium reduces fertility via reductions in embryo survival and increased inflammatory changes, respectively.

Oleic Acid enhances all-trans retinoic Acid loading in nano-lipid emulsions.

PubMed

Chinsriwongkul, Akhayachatra; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Sila-On, Warisada; Ruktanonchai, Uracha

2010-01-01

The aim of this study was to investigate the enhancement of all-trans retinoic acid (ATRA) loading in nano-lipid emulsions and stability by using oleic acid. The effect of formulation factors including initial ATRA concentration and the type of oil on the physicochemical properties, that is, percentage yield, percentage drug release, and photostability of formulations, was determined. The solubility of ATRA was increased in the order of oleic acid > MCT > soybean oil > water. The physicochemical properties of ATRA-loaded lipid emulsion, including mean particle diameter and zeta potential, were modulated by changing an initial ATRA concentration as well as the type and mixing ratio of oil and oleic acid as an oil phase. The particles of lipid emulsions had average sizes of less than 250 nm and negative zeta potential. The addition of oleic acid in lipid emulsions resulted in high loading capacity. The photodegradation rate was found to be dependent on the initial drug concentration but independent of the type of oily phase used in this study. The release rates were not affected by initial ATRA concentration but were affected by the type of oil, where oleic acid showed the highest release rate of ATRA from lipid emulsions.

Using fluorescent lipids in live zebrafish larvae: From imaging whole animal physiology to subcellular lipid trafficking.

PubMed

Anderson, J L; Carten, J D; Farber, S A

2016-01-01

Lipids serve essential functions in cells as signaling molecules, membrane components, and sources of energy. Defects in lipid metabolism are implicated in a number of pandemic human diseases, including diabetes, obesity, and hypercholesterolemia. Many aspects of how fatty acids and cholesterol are absorbed and processed by intestinal cells remain unclear and present a hurdle to developing approaches for disease prevention and treatment. Numerous studies have shown that the zebrafish is an excellent model for vertebrate lipid metabolism. In this chapter, we review commercially available fluorescent lipids that can be deployed in live zebrafish to better understand lipid signaling and metabolism. In this chapter, we present criteria one should consider when selecting specific fluorescent lipids for the study of digestive physiology or lipid metabolism in larval zebrafish. Copyright © 2016 Elsevier Inc. All rights reserved.

Alteration of lipid profile in subclinical hypothyroidism: a meta-analysis.

PubMed

Liu, Xiao-Li; He, Shan; Zhang, Shao-Fang; Wang, Jun; Sun, Xiu-Fa; Gong, Chun-Mei; Zheng, Shi-Jie; Zhou, Ji-Chang; Xu, Jian

2014-08-14

Previous studies yielded controversial results about the alteration of lipid profiles in patients with subclinical hypothyroidism. We performed a meta-analysis to investigate the association between subclinical hypothyroidism and lipid profiles. We searched PubMed, Cochrane Library, and China National Knowledge Infrastructure articles published January 1990 through January 2014. Dissertation databases (PQDT and CDMD) were searched for additional unpublished articles. We included articles reporting the relationship between subclinical hypothyroidism and at least 1 parameter of lipid profiles, and calculated the overall weighted mean difference (WMD) with a random effects model. Meta-regression was used to explore the source of heterogeneity among studies, and the Egger test, Begg test, and the trim and fill method were used to assess potential publication bias. Sixteen observational studies were included in our analysis. Meta-analysis suggested that the serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and total triglyceride levels were significantly increased in patients with subclinical hypothyroidism compared with euthyroidism individuals; the WMD were 12.17 mg/dl, 7.01 mg/dl, and 13.19 mg/dl, respectively (P<0.001 for all). No significant difference was observed for serum high-density lipoprotein cholesterol (HDL-C). Match strategy was the main source of heterogeneity among studies in TC and LDL-C analysis. Potential publication bias was found in TC and LDL-C analysis by the Egger test or Begg test and was not confirmed by the trim and fill method. Subclinical hypothyroidism may correlate with altered lipid profile. Previous studies had limitations in the control of potential confounding factors and further studies should consider those factors.

Alteration of Lipid Profile in Subclinical Hypothyroidism: A Meta-Analysis

PubMed Central

Liu, Xiao-Li; He, Shan; Zhang, Shao-Fang; Wang, Jun; Sun, Xiu-Fa; Gong, Chun-Mei; Zheng, Shi-Jie; Zhou, Ji-Chang; Xu, Jian

2014-01-01

Background Previous studies yielded controversial results about the alteration of lipid profiles in patients with subclinical hypothyroidism. We performed a meta-analysis to investigate the association between subclinical hypothyroidism and lipid profiles. Material/Methods We searched PubMed, Cochrane Library, and China National Knowledge Infrastructure articles published January 1990 through January 2014. Dissertation databases (PQDT and CDMD) were searched for additional unpublished articles. We included articles reporting the relationship between subclinical hypothyroidism and at least 1 parameter of lipid profiles, and calculated the overall weighted mean difference (WMD) with a random effects model. Meta-regression was used to explore the source of heterogeneity among studies, and the Egger test, Begg test, and the trim and fill method were used to assess potential publication bias. Results Sixteen observational studies were included in our analysis. Meta-analysis suggested that the serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and total triglyceride levels were significantly increased in patients with subclinical hypothyroidism compared with euthyroidism individuals; the WMD were 12.17 mg/dl, 7.01 mg/dl, and 13.19 mg/dl, respectively (P<0.001 for all). No significant difference was observed for serum high-density lipoprotein cholesterol (HDL-C). Match strategy was the main source of heterogeneity among studies in TC and LDL-C analysis. Potential publication bias was found in TC and LDL-C analysis by the Egger test or Begg test and was not confirmed by the trim and fill method. Conclusions Subclinical hypothyroidism may correlate with altered lipid profile. Previous studies had limitations in the control of potential confounding factors and further studies should consider those factors. PMID:25124461

Lipid14: The Amber Lipid Force Field

PubMed Central

2015-01-01

The AMBER lipid force field has been updated to create Lipid14, allowing tensionless simulation of a number of lipid types with the AMBER MD package. The modular nature of this force field allows numerous combinations of head and tail groups to create different lipid types, enabling the easy insertion of new lipid species. The Lennard-Jones and torsion parameters of both the head and tail groups have been revised and updated partial charges calculated. The force field has been validated by simulating bilayers of six different lipid types for a total of 0.5 μs each without applying a surface tension; with favorable comparison to experiment for properties such as area per lipid, volume per lipid, bilayer thickness, NMR order parameters, scattering data, and lipid lateral diffusion. As the derivation of this force field is consistent with the AMBER development philosophy, Lipid14 is compatible with the AMBER protein, nucleic acid, carbohydrate, and small molecule force fields. PMID:24803855

Subclinical hypothyroidism, lipid metabolism and cardiovascular disease.

PubMed

Delitala, Alessandro P; Fanciulli, Giuseppe; Maioli, Margherita; Delitala, Giuseppe

2017-03-01

Subclinical hypothyroidism is defined by elevated serum thyrotropin in presence of normal free thyroid hormones. Lipid metabolism is influenced by thyroid hormone and many reports showed that lipids status worsen along with TSH level. Subclinical hypothyroidism has been also linked to other cardiovascular risk factors such as alteration in blood pressure and increased atherosclerosis. Further evidences suggested that mild dysfunction of thyroid gland is associated with metabolic syndrome and heart failure. Thyrotropin level seems the best predictor of cardiovascular disease, in particular when its levels are above 10mU/L. However, despite these observations, there is no clear evidence that levothyroxine therapy in subjects with milder form of subclinical hypothyroidism could improve lipid status and the other cardiovascular risk factors. In this review, we address the effect of thyroid hormone and cardiovascular risk, with a focus on lipid metabolism. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Life-stage-associated remodelling of lipid metabolism regulation in Atlantic salmon.

PubMed

Gillard, Gareth; Harvey, Thomas N; Gjuvsland, Arne; Jin, Yang; Thomassen, Magny; Lien, Sigbjørn; Leaver, Michael; Torgersen, Jacob S; Hvidsten, Torgeir R; Vik, Jon Olav; Sandve, Simen R

2018-03-01

Atlantic salmon migrates from rivers to sea to feed, grow and develop gonads before returning to spawn in freshwater. The transition to marine habitats is associated with dramatic changes in the environment, including water salinity, exposure to pathogens and shift in dietary lipid availability. Many changes in physiology and metabolism occur across this life-stage transition, but little is known about the molecular nature of these changes. Here, we use a long-term feeding experiment to study transcriptional regulation of lipid metabolism in Atlantic salmon gut and liver in both fresh- and saltwater. We find that lipid metabolism becomes significantly less plastic to differences in dietary lipid composition when salmon transitions to saltwater and experiences increased dietary lipid availability. Expression of genes in liver relating to lipogenesis and lipid transport decreases overall and becomes less responsive to diet, while genes for lipid uptake in gut become more highly expressed. Finally, analyses of evolutionary consequences of the salmonid-specific whole-genome duplication on lipid metabolism reveal several pathways with significantly different (p < .05) duplicate retention or duplicate regulatory conservation. We also find a limited number of cases where the whole-genome duplication has resulted in an increased gene dosage. In conclusion, we find variable and pathway-specific effects of the salmonid genome duplication on lipid metabolism genes. A clear life-stage-associated shift in lipid metabolism regulation is evident, and we hypothesize this to be, at least partly, driven by nondietary factors such as the preparatory remodelling of gene regulation and physiology prior to sea migration. © 2018 John Wiley & Sons Ltd.

Serum homocysteine is not independently associated with an atherogenic lipid profile: The Very Large Database of Lipids (VLDL-21) study.

PubMed

Lupton, Joshua R; Quispe, Renato; Kulkarni, Krishnaji; Martin, Seth S; Jones, Steven R

2016-06-01

Hyperhomocysteinemia is an independent risk factor for cardiovascular disease, but the mechanism for this risk remains unclear. While reducing serum total homocysteine (tHcy) has been shown to decrease strokes, there is no evidence for an effect on myocardial infarctions in randomized controlled trials. This study aims to examine the relationship between tHcy and several lipid measures. Our analyses included 18,297 U.S. adults from the Very Large Database of Lipids who had an extended lipid panel including direct measurement of triglycerides (TG), and the cholesterol concentration of low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), non-HDL-C, very low-density lipoprotein (VLDL-C), and remnant-lipoprotein cholesterol (RLP-C: IDL-C + VLDL3-C). Additional measurements were tHcy, hemoglobin A1c (HbA1c), insulin, creatinine, and blood urea nitrogen (BUN). Subjects were categorized into tHcy quartiles. Linear regression models were performed using lipids and tHcy as dependent and independent variables respectively, and further adjusted with age, sex, HbA1c, insulin, creatinine, and BUN levels in multivariable regression. In unadjusted analysis, levels of LDL-C (p < 0.001), non-HDL-C (p < 0.001) and HDL-C (p < 0.001) were 7-10% lower whereas levels of TG (p < 0.001), VLDL-C (p = 0.016) and RLP-C (p < 0.001) were 2-6% higher in the highest tHcy quartile. These associations between tHcy levels and lipids were eliminated (p-value range: 0.101-0.750) when controlling for age, sex, HbA1c, insulin, creatinine, and BUN. Although high levels of tHcy were associated with 2-6% higher TG-rich lipoproteins in unadjusted analysis, after adjustment for confounders our findings do not support the hypothesis that hyperhomocysteinemia is associated with an atherogenic lipid profile. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Circadian regulation of intestinal lipid absorption by apolipoprotein AIV involves forkhead transcription factors A2 and O1 and microsomal triglyceride transfer protein.

PubMed

Pan, Xiaoyue; Munshi, Mohamed Khalid; Iqbal, Jahangir; Queiroz, Joyce; Sirwi, Alaa Ahmed; Shah, Shrenik; Younus, Abdullah; Hussain, M Mahmood

2013-07-12

We have shown previously that Clock, microsomal triglyceride transfer protein (MTP), and nocturnin are involved in the circadian regulation of intestinal lipid absorption. Here, we clarified the role of apolipoprotein AIV (apoAIV) in the diurnal regulation of plasma lipids and intestinal lipid absorption in mice. Plasma triglyceride in apoAIV(-/-) mice showed diurnal variations similar to apoAIV(+/+) mice; however, the increases in plasma triglyceride at night were significantly lower in these mice. ApoAIV(-/-) mice absorbed fewer lipids at night and showed blunted response to daytime feeding. To explain reasons for these lower responses, we measured MTP expression; intestinal MTP was low at night, and its induction after food entrainment was less in apoAIV(-/-) mice. Conversely, apoAIV overexpression increased MTP mRNA in hepatoma cells, indicating transcriptional regulation. Mechanistic studies revealed that sequences between -204/-775 bp in the MTP promoter respond to apoAIV and that apoAIV enhances expression of FoxA2 and FoxO1 transcription factors and their binding to the identified cis elements in the MTP promoter at night. Knockdown of FoxA2 and FoxO1 abolished apoAIV-mediated MTP induction. Similarly, knockdown of apoAIV in differentiated Caco-2 cells reduced MTP, FoxA2, and FoxO1 mRNA levels, cellular MTP activity, and media apoB. Moreover, FoxA2 and FoxO1 expression showed diurnal variations, and their expression was significantly lower in apoAIV(-/-) mice. These data indicate that apoAIV modulates diurnal changes in lipid absorption by regulating forkhead transcription factors and MTP and that inhibition of apoAIV expression might reduce plasma lipids.

Multifaceted role of lipids in Mycobacterium leprae.

PubMed

Kaur, Gurkamaljit; Kaur, Jagdeep

2017-03-01

Mycobacterium leprae must adopt a metabolic strategy and undergo various metabolic alterations upon infection to survive inside the human body for years in a dormant state. A change in lipid homeostasis upon infection is highly pronounced in Mycobacterium leprae. Lipids play an essential role in the survival and pathogenesis of mycobacteria. Lipids are present in several forms and serve multiple roles from being a source of nutrition, providing rigidity, evading the host immune response to serving as virulence factors, etc. The synthesis and degradation of lipids is a highly regulated process and is the key to future drug designing and diagnosis for mycobacteria. In the current review, an account of the distinct roles served by lipids, the mechanism of their synthesis and degradation has been elucidated.

Lipid Metabolism, Apoptosis and Cancer Therapy

PubMed Central

Huang, Chunfa; Freter, Carl

2015-01-01

Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy. PMID:25561239

Isolation and analysis of membrane lipids and lipid rafts in common carp (Cyprinus carpio L.).

PubMed

Brogden, Graham; Propsting, Marcus; Adamek, Mikolaj; Naim, Hassan Y; Steinhagen, Dieter

2014-03-01

Cell membranes act as an interface between the interior of the cell and the exterior environment and facilitate a range of essential functions including cell signalling, cell structure, nutrient uptake and protection. It is composed of a lipid bilayer with integrated proteins, and the inner leaflet of the lipid bilayer comprises of liquid ordered (Lo) and liquid disordered (Ld) domains. Lo microdomains, also named as lipid rafts are enriched in cholesterol, sphingomyelin and certain types of proteins, which facilitate cell signalling and nutrient uptake. Lipid rafts have been extensively researched in mammals and the presence of functional lipid rafts was recently demonstrated in goldfish, but there is currently very little knowledge about their composition and function in fish. Therefore a protocol was established for the analysis of lipid rafts and membranous lipids in common carp (Cyprinus carpio L.) tissues. Twelve lipids were identified and analysed in the Ld domain of the membrane with the most predominant lipids found in all tissues being; triglycerides, cholesterol, phosphoethanolamine and phosphatidylcholine. Four lipids were identified in lipid rafts in all tissues analysed, triglycerides (33-62%) always found in the highest concentration followed by cholesterol (24-32%), phosphatidylcholine and sphingomyelin. Isolation of lipid rafts was confirmed by identifying the presence of the lipid raft associated protein flotillin, present at higher concentrations in the detergent resistant fraction. The data provided here build a lipid library of important carp tissues as a baseline for further studies into virus entry, protein trafficking or environmental stress analysis. Copyright © 2013 Elsevier Inc. All rights reserved.

Immunopharmacology of lipid A mimetics.

PubMed

Bowen, William S; Gandhapudi, Siva K; Kolb, Joseph P; Mitchell, Thomas C

2013-01-01

The structural core of bacterial lipopolysaccharide, lipid A, has played a role in medicine since the 1890s when William Coley sought to harness its immunostimulatory properties in the form of a crude bacterial extract. Recent decades have brought remarkable clarity to the structure of lipid A and the multicomponent endotoxin receptor system that evolved to detect it. A range of therapeutically useful versions of lipid A now exists, including preparations of detoxified lipid A, synthetic copies of naturally occurring biological intermediates such as lipid IVa, and synthetic mimetics. These agents are finding use as vaccine adjuvants, antagonists and immunostimulants whose structural features have been refined to potentiate efficacy while decreasing the risk of inflammatory side effects. Copyright © 2013 Elsevier Inc. All rights reserved.

Specificity of Intramembrane Protein–Lipid Interactions

PubMed Central

Contreras, Francesc-Xabier; Ernst, Andreas Max; Wieland, Felix; Brügger, Britta

2011-01-01

Our concept of biological membranes has markedly changed, from the fluid mosaic model to the current model that lipids and proteins have the ability to separate into microdomains, differing in their protein and lipid compositions. Since the breakthrough in crystallizing membrane proteins, the most powerful method to define lipid-binding sites on proteins has been X-ray and electron crystallography. More recently, chemical biology approaches have been developed to analyze protein–lipid interactions. Such methods have the advantage of providing highly specific cellular probes. With the advent of novel tools to study functions of individual lipid species in membranes together with structural analysis and simulations at the atomistic resolution, a growing number of specific protein–lipid complexes are defined and their functions explored. In the present article, we discuss the various modes of intramembrane protein–lipid interactions in cellular membranes, including examples for both annular and nonannular bound lipids. Furthermore, we will discuss possible functional roles of such specific protein–lipid interactions as well as roles of lipids as chaperones in protein folding and transport. PMID:21536707

Biological, Clinical, and Population Relevance of 95 Loci for Blood Lipids

PubMed Central

Teslovich, Tanya M.; Musunuru, Kiran; Smith, Albert V.; Edmondson, Andrew C.; Stylianou, Ioannis M.; Koseki, Masahiro; Pirruccello, James P.; Ripatti, Samuli; Chasman, Daniel I.; Willer, Cristen J.; Johansen, Christopher T.; Fouchier, Sigrid W.; Isaacs, Aaron; Peloso, Gina M.; Barbalic, Maja; Ricketts, Sally L.; Bis, Joshua C.; Aulchenko, Yurii S.; Thorleifsson, Gudmar; Feitosa, Mary F.; Chambers, John; Orho-Melander, Marju; Melander, Olle; Johnson, Toby; Li, Xiaohui; Guo, Xiuqing; Li, Mingyao; Cho, Yoon Shin; Go, Min Jin; Kim, Young Jin; Lee, Jong-Young; Park, Taesung; Kim, Kyunga; Sim, Xueling; Ong, Rick Twee-Hee; Croteau-Chonka, Damien C.; Lange, Leslie A.; Smith, Joshua D.; Song, Kijoung; Zhao, Jing Hua; Yuan, Xin; Luan, Jian'an; Lamina, Claudia; Ziegler, Andreas; Zhang, Weihua; Zee, Robert Y.L.; Wright, Alan F.; Witteman, Jacqueline C.M.; Wilson, James F.; Willemsen, Gonneke; Wichmann, H-Erich; Whitfield, John B.; Waterworth, Dawn M.; Wareham, Nicholas J.; Waeber, Gérard; Vollenweider, Peter; Voight, Benjamin F.; Vitart, Veronique; Uitterlinden, Andre G.; Uda, Manuela; Tuomilehto, Jaakko; Thompson, John R.; Tanaka, Toshiko; Surakka, Ida; Stringham, Heather M.; Spector, Tim D.; Soranzo, Nicole; Smit, Johannes H.; Sinisalo, Juha; Silander, Kaisa; Sijbrands, Eric J.G.; Scuteri, Angelo; Scott, James; Schlessinger, David; Sanna, Serena; Salomaa, Veikko; Saharinen, Juha; Sabatti, Chiara; Ruokonen, Aimo; Rudan, Igor; Rose, Lynda M.; Roberts, Robert; Rieder, Mark; Psaty, Bruce M.; Pramstaller, Peter P.; Pichler, Irene; Perola, Markus; Penninx, Brenda W.J.H.; Pedersen, Nancy L.; Pattaro, Cristian; Parker, Alex N.; Pare, Guillaume; Oostra, Ben A.; O'Donnell, Christopher J.; Nieminen, Markku S.; Nickerson, Deborah A.; Montgomery, Grant W.; Meitinger, Thomas; McPherson, Ruth; McCarthy, Mark I.; McArdle, Wendy; Masson, David; Martin, Nicholas G.; Marroni, Fabio; Mangino, Massimo; Magnusson, Patrik K.E.; Lucas, Gavin; Luben, Robert; Loos, Ruth J. F.; Lokki, Maisa; Lettre, Guillaume; Langenberg, Claudia; Launer, Lenore J.; Lakatta, Edward G.; Laaksonen, Reijo; Kyvik, Kirsten O.; Kronenberg, Florian; König, Inke R.; Khaw, Kay-Tee; Kaprio, Jaakko; Kaplan, Lee M.; Johansson, Åsa; Jarvelin, Marjo-Riitta; Janssens, A. Cecile J.W.; Ingelsson, Erik; Igl, Wilmar; Hovingh, G. Kees; Hottenga, Jouke-Jan; Hofman, Albert; Hicks, Andrew A.; Hengstenberg, Christian; Heid, Iris M.; Hayward, Caroline; Havulinna, Aki S.; Hastie, Nicholas D.; Harris, Tamara B.; Haritunians, Talin; Hall, Alistair S.; Gyllensten, Ulf; Guiducci, Candace; Groop, Leif C.; Gonzalez, Elena; Gieger, Christian; Freimer, Nelson B.; Ferrucci, Luigi; Erdmann, Jeanette; Elliott, Paul; Ejebe, Kenechi G.; Döring, Angela; Dominiczak, Anna F.; Demissie, Serkalem; Deloukas, Panagiotis; de Geus, Eco J.C.; de Faire, Ulf; Crawford, Gabriel; Collins, Francis S.; Chen, Yii-der I.; Caulfield, Mark J.; Campbell, Harry; Burtt, Noel P.; Bonnycastle, Lori L.; Boomsma, Dorret I.; Boekholdt, S. Matthijs; Bergman, Richard N.; Barroso, Inês; Bandinelli, Stefania; Ballantyne, Christie M.; Assimes, Themistocles L.; Quertermous, Thomas; Altshuler, David; Seielstad, Mark; Wong, Tien Y.; Tai, E-Shyong; Feranil, Alan B.; Kuzawa, Christopher W.; Adair, Linda S.; Taylor, Herman A.; Borecki, Ingrid B.; Gabriel, Stacey B.; Wilson, James G.; Stefansson, Kari; Thorsteinsdottir, Unnur; Gudnason, Vilmundur; Krauss, Ronald M.; Mohlke, Karen L.; Ordovas, Jose M.; Munroe, Patricia B.; Kooner, Jaspal S.; Tall, Alan R.; Hegele, Robert A.; Kastelein, John J.P.; Schadt, Eric E.; Rotter, Jerome I.; Boerwinkle, Eric; Strachan, David P.; Mooser, Vincent; Holm, Hilma; Reilly, Muredach P.; Samani, Nilesh J; Schunkert, Heribert; Cupples, L. Adrienne; Sandhu, Manjinder S.; Ridker, Paul M; Rader, Daniel J.; van Duijn, Cornelia M.; Peltonen, Leena; Abecasis, Gonçalo R.; Boehnke, Michael; Kathiresan, Sekar

2010-01-01

Serum concentrations of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with serum lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 × 10-8), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (e.g., CYP7A1, NPC1L1, and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and impact lipid traits in three non-European populations (East Asians, South Asians, and African Americans). Our results identify several novel loci associated with serum lipids that are also associated with CAD. Finally, we validated three of the novel genes—GALNT2, PPP1R3B, and TTC39B—with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD. PMID:20686565

Biological, clinical and population relevance of 95 loci for blood lipids.

PubMed

Teslovich, Tanya M; Musunuru, Kiran; Smith, Albert V; Edmondson, Andrew C; Stylianou, Ioannis M; Koseki, Masahiro; Pirruccello, James P; Ripatti, Samuli; Chasman, Daniel I; Willer, Cristen J; Johansen, Christopher T; Fouchier, Sigrid W; Isaacs, Aaron; Peloso, Gina M; Barbalic, Maja; Ricketts, Sally L; Bis, Joshua C; Aulchenko, Yurii S; Thorleifsson, Gudmar; Feitosa, Mary F; Chambers, John; Orho-Melander, Marju; Melander, Olle; Johnson, Toby; Li, Xiaohui; Guo, Xiuqing; Li, Mingyao; Shin Cho, Yoon; Jin Go, Min; Jin Kim, Young; Lee, Jong-Young; Park, Taesung; Kim, Kyunga; Sim, Xueling; Twee-Hee Ong, Rick; Croteau-Chonka, Damien C; Lange, Leslie A; Smith, Joshua D; Song, Kijoung; Hua Zhao, Jing; Yuan, Xin; Luan, Jian'an; Lamina, Claudia; Ziegler, Andreas; Zhang, Weihua; Zee, Robert Y L; Wright, Alan F; Witteman, Jacqueline C M; Wilson, James F; Willemsen, Gonneke; Wichmann, H-Erich; Whitfield, John B; Waterworth, Dawn M; Wareham, Nicholas J; Waeber, Gérard; Vollenweider, Peter; Voight, Benjamin F; Vitart, Veronique; Uitterlinden, Andre G; Uda, Manuela; Tuomilehto, Jaakko; Thompson, John R; Tanaka, Toshiko; Surakka, Ida; Stringham, Heather M; Spector, Tim D; Soranzo, Nicole; Smit, Johannes H; Sinisalo, Juha; Silander, Kaisa; Sijbrands, Eric J G; Scuteri, Angelo; Scott, James; Schlessinger, David; Sanna, Serena; Salomaa, Veikko; Saharinen, Juha; Sabatti, Chiara; Ruokonen, Aimo; Rudan, Igor; Rose, Lynda M; Roberts, Robert; Rieder, Mark; Psaty, Bruce M; Pramstaller, Peter P; Pichler, Irene; Perola, Markus; Penninx, Brenda W J H; Pedersen, Nancy L; Pattaro, Cristian; Parker, Alex N; Pare, Guillaume; Oostra, Ben A; O'Donnell, Christopher J; Nieminen, Markku S; Nickerson, Deborah A; Montgomery, Grant W; Meitinger, Thomas; McPherson, Ruth; McCarthy, Mark I; McArdle, Wendy; Masson, David; Martin, Nicholas G; Marroni, Fabio; Mangino, Massimo; Magnusson, Patrik K E; Lucas, Gavin; Luben, Robert; Loos, Ruth J F; Lokki, Marja-Liisa; Lettre, Guillaume; Langenberg, Claudia; Launer, Lenore J; Lakatta, Edward G; Laaksonen, Reijo; Kyvik, Kirsten O; Kronenberg, Florian; König, Inke R; Khaw, Kay-Tee; Kaprio, Jaakko; Kaplan, Lee M; Johansson, Asa; Jarvelin, Marjo-Riitta; Janssens, A Cecile J W; Ingelsson, Erik; Igl, Wilmar; Kees Hovingh, G; Hottenga, Jouke-Jan; Hofman, Albert; Hicks, Andrew A; Hengstenberg, Christian; Heid, Iris M; Hayward, Caroline; Havulinna, Aki S; Hastie, Nicholas D; Harris, Tamara B; Haritunians, Talin; Hall, Alistair S; Gyllensten, Ulf; Guiducci, Candace; Groop, Leif C; Gonzalez, Elena; Gieger, Christian; Freimer, Nelson B; Ferrucci, Luigi; Erdmann, Jeanette; Elliott, Paul; Ejebe, Kenechi G; Döring, Angela; Dominiczak, Anna F; Demissie, Serkalem; Deloukas, Panagiotis; de Geus, Eco J C; de Faire, Ulf; Crawford, Gabriel; Collins, Francis S; Chen, Yii-der I; Caulfield, Mark J; Campbell, Harry; Burtt, Noel P; Bonnycastle, Lori L; Boomsma, Dorret I; Boekholdt, S Matthijs; Bergman, Richard N; Barroso, Inês; Bandinelli, Stefania; Ballantyne, Christie M; Assimes, Themistocles L; Quertermous, Thomas; Altshuler, David; Seielstad, Mark; Wong, Tien Y; Tai, E-Shyong; Feranil, Alan B; Kuzawa, Christopher W; Adair, Linda S; Taylor, Herman A; Borecki, Ingrid B; Gabriel, Stacey B; Wilson, James G; Holm, Hilma; Thorsteinsdottir, Unnur; Gudnason, Vilmundur; Krauss, Ronald M; Mohlke, Karen L; Ordovas, Jose M; Munroe, Patricia B; Kooner, Jaspal S; Tall, Alan R; Hegele, Robert A; Kastelein, John J P; Schadt, Eric E; Rotter, Jerome I; Boerwinkle, Eric; Strachan, David P; Mooser, Vincent; Stefansson, Kari; Reilly, Muredach P; Samani, Nilesh J; Schunkert, Heribert; Cupples, L Adrienne; Sandhu, Manjinder S; Ridker, Paul M; Rader, Daniel J; van Duijn, Cornelia M; Peltonen, Leena; Abecasis, Gonçalo R; Boehnke, Michael; Kathiresan, Sekar

2010-08-05

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD.

Lipid Panel

MedlinePlus

... Time and International Normalized Ratio (PT/INR) PSEN1 Quantitative Immunoglobulins Red Blood Cell (RBC) Antibody Identification Red ... typically includes a fasting lipid panel. Beyond that, research continues into the usefulness of other non-traditional ...

Mitochondrial lipids in neurodegeneration.

PubMed

Aufschnaiter, Andreas; Kohler, Verena; Diessl, Jutta; Peselj, Carlotta; Carmona-Gutierrez, Didac; Keller, Walter; Büttner, Sabrina

2017-01-01

Mitochondrial dysfunction is a common feature of many neurodegenerative diseases, including proteinopathies such as Alzheimer's or Parkinson's disease, which are characterized by the deposition of aggregated proteins in the form of insoluble fibrils or plaques. The distinct molecular processes that eventually result in mitochondrial dysfunction during neurodegeneration are well studied but still not fully understood. However, defects in mitochondrial fission and fusion, mitophagy, oxidative phosphorylation and mitochondrial bioenergetics have been linked to cellular demise. These processes are influenced by the lipid environment within mitochondrial membranes as, besides membrane structure and curvature, recruitment and activity of different proteins also largely depend on the respective lipid composition. Hence, the interaction of neurotoxic proteins with certain lipids and the modification of lipid composition in different cell compartments, in particular mitochondria, decisively impact cell death associated with neurodegeneration. Here, we discuss the relevance of mitochondrial lipids in the pathological alterations that result in neuronal demise, focussing on proteinopathies.

Emerging targets in lipid-based therapy☆

PubMed Central

Tucker, Stephanie C.; Honn, Kenneth V.

2013-01-01

The use of prostaglandins and NSAIDS in the clinic has proven that lipid mediators and their associated pathways make attractive therapeutic targets. When contemplating therapies involving lipid pathways, several basic agents come to mind. There are the enzymes and accessory proteins that lead to the metabolism of lipid substrates, provided through diet or through actions of lipases, the subsequent lipid products, and finally the lipid sensors or receptors. There is abundant evidence that molecules along this lipid continuum can serve as prognostic and diagnostic indicators and are in fact viable therapeutic targets. Furthermore, lipids themselves can be used as therapeutics. Despite this, the vernacular dialog pertaining to “biomarkers” does not routinely include mention of lipids, though this is rapidly changing. Collectively these agents are becoming more appreciated for their respective roles in diverse disease processes from cancer to preterm labor and are receiving their due appreciation after decades of ground work in the lipid field. By relating examples of disease processes that result from dysfunction along the lipid continuum, as well as examples of lipid therapies and emerging technologies, this review is meant to inspire further reading and discovery. PMID:23261527

Atherogenic dyslipidemia: prevalence and management in lipid clinics.

PubMed

Pedro-Botet, J; Flores-Le Roux, J A; Mostaza, J M; Pintó, X; de la Cruz, J J; Banegas, J R

2014-12-01

Atherogenic dyslipidemia, which is characterized by increased triglyceride levels and reduced HDL cholesterol levels, is underestimated and undertreated in clinical practice. We assessed its prevalence and the achievement of therapeutic objectives for HDL cholesterol and triglyceride levels in patients treated at lipid and vascular risk units in Spain. This was an observational, longitudinal, retrospective, multicenter study performed in 14 autonomous Spanish communities that consecutively included 1828 patients aged ≥18 years who were referred for dyslipidemia and vascular risk to 43 lipid clinics accredited by the Spanish Society of Arteriosclerosis. We collected information from the medical records corresponding to 2 visits conducted during 2010 and 2011-12, respectively. Of the 1649 patients who had a lipid profile in the first visit (90.2%), 295 (17.9%) had atherogenic dyslipidemia. The factors associated with atherogenic dyslipidemia were excess weight/obesity, not taking hypolipidemic drugs (statins and/or fibrates), diabetes, myocardial infarction and previous heart failure. Of the 273 (92.5%) patients with atherogenic dyslipidemia that had a lipid profile in the last visit, 44 (16.1%) achieved the therapeutic objectives for HDL cholesterol and triglyceride levels. The predictors of therapeutic success were normal weight and normoglycemia. One of every 6 patients treated in lipid and vascular risk units had atherogenic dyslipidemia. The degree to which the therapeutic goals for HDL cholesterol and triglyceride levels were achieved in these patients was very low. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Natural lipid extracts and biomembrane-mimicking lipid compositions are disposed to form nonlamellar phases, and they release DNA from lipoplexes most efficiently

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koynova, Rumiana; MacDonald, Robert C.

2010-01-18

A viewpoint now emerging is that a critical factor in lipid-mediated transfection (lipofection) is the structural evolution of lipoplexes upon interacting and mixing with cellular lipids. Here we report our finding that lipid mixtures mimicking biomembrane lipid compositions are superior to pure anionic liposomes in their ability to release DNA from lipoplexes (cationic lipid/DNA complexes), even though they have a much lower negative charge density (and thus lower capacity to neutralize the positive charge of the lipoplex lipids). Flow fluorometry revealed that the portion of DNA released after a 30-min incubation of the cationic O-ethylphosphatidylcholine lipoplexes with the anionic phosphatidylserinemore » or phosphatidylglycerol was 19% and 37%, respectively, whereas a mixture mimicking biomembranes (MM: phosphatidylcholine/phosphatidylethanolamine/phosphatidylserine /cholesterol 45:20:20:15 w/w) and polar lipid extract from bovine liver released 62% and 74%, respectively, of the DNA content. A possible reason for this superior power in releasing DNA by the natural lipid mixtures was suggested by structural experiments: while pure anionic lipids typically form lamellae, the natural lipid mixtures exhibited a surprising predilection to form nonlamellar phases. Thus, the MM mixture arranged into lamellar arrays at physiological temperature, but began to convert to the hexagonal phase at a slightly higher temperature, {approx} 40-45 C. A propensity to form nonlamellar phases (hexagonal, cubic, micellar) at close to physiological temperatures was also found with the lipid extracts from natural tissues (from bovine liver, brain, and heart). This result reveals that electrostatic interactions are only one of the factors involved in lipid-mediated DNA delivery. The tendency of lipid bilayers to form nonlamellar phases has been described in terms of bilayer 'frustration' which imposes a nonzero intrinsic curvature of the two opposing monolayers. Because the stored

Natural lipid extracts and biomembrane-mimicking lipid compositions are disposed to form nonlamellar phases, and they release DNA from lipoplexes most efficiently

PubMed Central

Koynova, Rumiana; MacDonald, Robert C.

2007-01-01

A viewpoint now emerging is that a critical factor in lipid-mediated transfection (lipofection) is the structural evolution of lipoplexes upon interacting and mixing with cellular lipids. Here we report our finding that lipid mixtures mimicking biomembrane lipid compositions are superior to pure anionic liposomes in their ability to release DNA from lipoplexes (cationic lipid/DNA complexes), even though they have a much lower negative charge density (and thus lower capacity to neutralize the positive charge of the lipoplex lipids). Flow fluorometry revealed that the portion of DNA released after a 30 min incubation of the cationic O-ethylphosphatidylcholine lipoplexes with the anionic phosphatidylserine or phosphatidylglycerol was 19% and 37%, respectively, whereas a mixture mimicking biomembranes (MM: phosphatidylcholine/phosphatidylethanolamine/ phosphatidylserine/cholesterol 45:20:20:15 w/w) and polar lipid extract from bovine liver released 62% and 74%, respectively, of the DNA content. A possible reason for this superior power in releasing DNA by the natural lipid mixtures was suggested by structural experiments: while pure anionic lipids typically form lamellae, the natural lipid mixtures exhibited a surprising predilection to form nonlamellar phases. Thus, the MM mixture arranged into lamellar arrays at physiological temperature, but began to convert to the hexagonal phase at a slightly higher temperature, ∼40-45°C. A propensity to form nonlamellar phases (hexagonal, cubic, micellar) at close to physiological temperatures was also found with the lipid extracts from natural tissues (from bovine liver, brain, and heart). This result reveals that electrostatic interactions are only one of the factors involved in lipid-mediated DNA delivery. The tendency of lipid bilayers to form nonlamellar phases has been described in terms of bilayer “frustration” which imposes a nonzero intrinsic curvature of the two opposing monolayers. Because the stored curvature

Nontargeted quantitation of lipid classes using hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry with single internal standard and response factor approach.

PubMed

Cífková, Eva; Holčapek, Michal; Lísa, Miroslav; Ovčačíková, Magdaléna; Lyčka, Antonín; Lynen, Frédéric; Sandra, Pat

2012-11-20

The identification and quantitation of a wide range of lipids in complex biological samples is an essential requirement for the lipidomic studies. High-performance liquid chromatography-mass spectrometry (HPLC/MS) has the highest potential to obtain detailed information on the whole lipidome, but the reliable quantitation of multiple lipid classes is still a challenging task. In this work, we describe a new method for the nontargeted quantitation of polar lipid classes separated by hydrophilic interaction liquid chromatography (HILIC) followed by positive-ion electrospray ionization mass spectrometry (ESI-MS) using a single internal lipid standard to which all class specific response factors (RFs) are related to. The developed method enables the nontargeted quantitation of lipid classes and molecules inside these classes in contrast to the conventional targeted quantitation, which is based on predefined selected reaction monitoring (SRM) transitions for selected lipids only. In the nontargeted quantitation method described here, concentrations of lipid classes are obtained by the peak integration in HILIC chromatograms multiplied by their RFs related to the single internal standard (i.e., sphingosyl PE, d17:1/12:0) used as common reference for all polar lipid classes. The accuracy, reproducibility and robustness of the method have been checked by various means: (1) the comparison with conventional lipidomic quantitation using SRM scans on a triple quadrupole (QqQ) mass analyzer, (2) (31)P nuclear magnetic resonance (NMR) quantitation of the total lipid extract, (3) method robustness test using subsequent measurements by three different persons, (4) method transfer to different HPLC/MS systems using different chromatographic conditions, and (5) comparison with previously published results for identical samples, especially human reference plasma from the National Institute of Standards and Technology (NIST human plasma). Results on human plasma, egg yolk and porcine

Influence of encapsulated functional lipids on crystal structure and chemical stability in solid lipid nanoparticles: Towards bioactive-based design of delivery systems.

PubMed

Salminen, Hanna; Gömmel, Christina; Leuenberger, Bruno H; Weiss, Jochen

2016-01-01

We investigated the influence of physicochemical properties of encapsulated functional lipids--vitamin A, β-carotene and ω-3 fish oil--on the structural arrangement of solid lipid nanoparticles (SLN). The relationship between the crystal structure and chemical stability of the incorporated bioactive lipids was evaluated with different emulsifier compositions of a saponin-rich, food-grade Quillaja extract alone or combined with high-melting or low-melting lecithins. The major factors influencing the structural arrangement and chemical stability of functional lipids in solid lipid dispersions were their solubility in the aqueous phase and their crystallization temperature in relation to that of the carrier lipid. The results showed that the stabilization of the α-subcell crystals in the lattice of the carrier lipid is a key parameter for forming stable solid lipid dispersions. This study contributes to a better understanding of SLN as a function of the bioactive lipid. Copyright © 2015 Elsevier Ltd. All rights reserved.

The use of lipid-lowering therapy for secondary prevention in patients undergoing percutaneous coronary intervention

PubMed Central

Ma, Jessica M; Jackevicius, Cynthia A; Genus, Uchenwa; Dzavik, Vladimir

2006-01-01

BACKGROUND Recent literature suggests that lipid-lowering therapy may have an early beneficial effect among patients undergoing percutaneous coronary intervention (PCI) because the therapy decreases cardiac mortality, morbidity and possibly restenosis. OBJECTIVE The primary objective of the present study was to determine the proportion of PCI patients receiving lipid-lowering therapy at a large, tertiary-care referral centre. METHODS Patients undergoing a first PCI between August 2000 and August 2002 with corresponding inpatient medication information were included in the study. Patient demographics, procedural variables, and lipid-lowering and other evidence-based cardiac medication data were collected. A multiple logistical regression model was constructed to evaluate the factors associated with the use of lipid-lowering therapy. RESULTS Of the 3254 cases included in the analyses, 52% were elective, 44% were urgent or salvage, and 4% were emergent. The mean patient age was 63 years, and 73% of patients were male. Over 76% of patients were receiving lipid-lowering therapy at the time of PCI. Patient use of other medications was as follows: acetylsalicylic acid in 96%, beta-blocker in 80% and angiotensin-converting enzyme inhibitor in 59%. In the multiple regression analysis, variables significantly associated with lipid-lowering therapy use included hypercholesterolemia, beta-blocker use, angiotensin-converting enzyme inhibitor use, case urgency, prior coronary artery bypass graft surgery, age and sex. CONCLUSION Lipid-lowering therapy use rates exceeded those previously reported in the literature. Women and patients undergoing elective procedures appear to be treated less often with lipid-lowering therapy. There remains an opportunity to further optimize use in this high-risk cohort at time of PCI. PMID:16639478

Permeability of boric acid across lipid bilayers and factors affecting it.

PubMed

Dordas, C; Brown, P H

2000-05-15

Boron enters plant roots as undissociated boric acid (H(3)BO(3)). Significant differences in B uptake are frequently observed even when plants are grown under identical conditions. It has been theorized that these differences reflect species differences in permeability coefficient of H(3)BO(3) across plasma membrane. The permeability coefficient of boric acid however, has not been experimentally determined across any artificial or plant membrane. In the experiments described here the permeability coefficient of boric acid in liposomes made of phosphatidylcholine was 4.9x10(-6) cm sec(-1), which is in good agreement with the theoretical value. The permeability coefficient varied from 7x10(-6) to 9.5x10(-9) cm sec(-1) with changes in sterols (cholesterol), the type of phospholipid head group, the length of the fatty acyl chain, and the pH of the medium. In this study we also used Arabidopsis thaliana mutants which differ in lipid composition to study the effect of lipid composition on B uptake. The chs1-1 mutant which has lower proportion of sterols shows 30% higher B uptake compared with the wild type, while the act1-1 mutant which has an increased percentage of longer fatty acids, exhibited 35% lower uptake than the wild type. Lipid composition changes in each of the remaining mutants influenced B uptake to various extents. These data suggest that lipid composition of the plasma membrane can affect total B uptake.

Lipids and bariatric procedures Part 2 of 2: scientific statement from the American Society for Metabolic and Bariatric Surgery (ASMBS), the National Lipid Association (NLA), and Obesity Medicine Association (OMA).

PubMed

Bays, Harold; Kothari, Shanu N; Azagury, Dan E; Morton, John M; Nguyen, Ninh T; Jones, Peter H; Jacobson, Terry A; Cohen, David E; Orringer, Carl; Westman, Eric C; Horn, Deborah B; Scinta, Wendy; Primack, Craig

2016-01-01

Bariatric procedures generally improve dyslipidemia, sometimes substantially so. Bariatric procedures also improve other major cardiovascular risk factors. This 2-part Scientific Statement examines the lipid effects of bariatric procedures and reflects contributions from authors representing the American Society for Metabolic and Bariatric Surgery (ASMBS), the National Lipid Association (NLA), and the Obesity Medicine Association (OMA). Part 1 was published in the Journal of Clinical Lipidology, and reviewed the impact of bariatric procedures upon adipose tissue endocrine and immune factors, adipose tissue lipid metabolism, as well as the lipid effects of bariatric procedures relative to bile acids and intestinal microbiota. This Part 2 reviews: (1) the importance of nutrients (fats, carbohydrates, and proteins) and their absorption on lipid levels; (2) the effects of bariatric procedures on gut hormones and lipid levels; (3) the effects of bariatric procedures on nonlipid cardiovascular disease (CVD) risk factors; (4) the effects of bariatric procedures on lipid levels; (5) effects of bariatric procedures on CVD; and finally, (6) the potential lipid effects of vitamin, mineral, and trace element deficiencies, that may occur after bariatric procedures. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Polar lipid composition of mammalian hair.

PubMed

Wix, M A; Wertz, P W; Downing, D T

1987-01-01

The types and amounts of polar lipids from the hair of monkey (Macacca fascicularis), dog (Canis familiaris), pig (Sus scrofa) and porcupine (Erethizon dorsatum) have been determined by quantitative thin-layer chromatography. The polar lipid content of the hair samples ranged from 0.6 to 1.6 wt%. Lipid compositions included ceramides (57-63% of the polar lipid by weight), glycosphingolipids (7-9%) and cholesteryl sulfate (22-29%). Several minor components (4-7%) remain unidentified. The results suggest that cholesteryl sulfate may be an important determinant of the cohesiveness of hair.

Transcriptional Regulation of T-Cell Lipid Metabolism: Implications for Plasma Membrane Lipid Rafts and T-Cell Function.

PubMed

Robinson, George A; Waddington, Kirsty E; Pineda-Torra, Ines; Jury, Elizabeth C

2017-01-01

It is well established that cholesterol and glycosphingolipids are enriched in the plasma membrane (PM) and form signaling platforms called lipid rafts, essential for T-cell activation and function. Moreover, changes in PM lipid composition affect the biophysical properties of lipid rafts and have a role in defining functional T-cell phenotypes. Here, we review the role of transcriptional regulators of lipid metabolism including liver X receptors α/β, peroxisome proliferator-activated receptor γ, estrogen receptors α/β (ERα/β), and sterol regulatory element-binding proteins in T-cells. These receptors lie at the interface between lipid metabolism and immune cell function and are endogenously activated by lipids and/or hormones. Importantly, they regulate cellular cholesterol, fatty acid, glycosphingolipid, and phospholipid levels but are also known to modulate a broad spectrum of immune responses. The current evidence supporting a role for lipid metabolism pathways in controlling immune cell activation by influencing PM lipid raft composition in health and disease, and the potential for targeting lipid biosynthesis pathways to control unwanted T-cell activation in autoimmunity is reviewed.

Transcriptional Regulation of T-Cell Lipid Metabolism: Implications for Plasma Membrane Lipid Rafts and T-Cell Function

PubMed Central

Robinson, George A.; Waddington, Kirsty E.; Pineda-Torra, Ines; Jury, Elizabeth C.

2017-01-01

It is well established that cholesterol and glycosphingolipids are enriched in the plasma membrane (PM) and form signaling platforms called lipid rafts, essential for T-cell activation and function. Moreover, changes in PM lipid composition affect the biophysical properties of lipid rafts and have a role in defining functional T-cell phenotypes. Here, we review the role of transcriptional regulators of lipid metabolism including liver X receptors α/β, peroxisome proliferator-activated receptor γ, estrogen receptors α/β (ERα/β), and sterol regulatory element-binding proteins in T-cells. These receptors lie at the interface between lipid metabolism and immune cell function and are endogenously activated by lipids and/or hormones. Importantly, they regulate cellular cholesterol, fatty acid, glycosphingolipid, and phospholipid levels but are also known to modulate a broad spectrum of immune responses. The current evidence supporting a role for lipid metabolism pathways in controlling immune cell activation by influencing PM lipid raft composition in health and disease, and the potential for targeting lipid biosynthesis pathways to control unwanted T-cell activation in autoimmunity is reviewed. PMID:29225604

Future directions in lipid therapies.

PubMed

Ansell, Benjamin

2002-01-01

Cholesterol management to reduce the burden of cardiovascular disease is a major public health concern. Despite widespread recognition of lipid abnormalities as cardiovascular risk factors, significant cardiovascular event reductions with cholesterol-lowering therapies, and dissemination of treatment guidelines, most high-risk patients are not at target lipid levels. In addition to lifestyle changes, four major drug classes are available to modify lipid levels: fibrates, niacin, resins, and statins. High efficacy and tolerability in clinical trials make statins the most widely prescribed of these agents. Newer, more potent members of this class and novel formulations of niacin and resins may provide more effective therapy for dyslipidemia with fewer side effects. Several agents in development (cholesterol-absorption inhibitors and ACAT inhibitors) exploit mechanisms of action complementary to those of current treatments and combined with statins may produce greater improvements in lipid profiles than are now possible. These innovations should enable a greater number of patients to achieve more aggressive cholesterol goals, thereby reducing the risk of cardiovascular events.

Introduction to fatty acids and lipids.

PubMed

Burdge, Graham C; Calder, Philip C

2015-01-01

The purpose of this article is to describe the structure, function and metabolism of fatty acids and lipids that are of particular importance in the context of parenteral nutrition. Lipids are a heterogeneous group of molecules that share the common property of hydrophobicity. Lipids range in structure from simple short hydrocarbon chains to more complex molecules, including triacylglycerols, phospholipids and sterols and their esters. Lipids within each class may differ structurally. Fatty acids are common components of complex lipids, and these differ according to chain length and the presence, number and position of double bonds in the hydrocarbon chain. Structural variation among complex lipids and among fatty acids gives rise to functional differences that result in different impacts upon metabolism and upon cell and tissue responses. Fatty acids and complex lipids exhibit a variety of structural variations that influence their metabolism and their functional effects. © 2015 S. Karger AG, Basel.

Effects of a Western-type diet on plasma lipids and other cardiometabolic risk factors in African green monkeys (Chlorocebus aethiops sabaeus).

PubMed

Jorgensen, Matthew J; Aycock, S Tyler; Clarkson, Thomas B; Kaplan, Jay R

2013-07-01

Our goal was to assess a nonhuman primate diet that mimicked the Western-type diet of humans with regard to palatability and the diet's effects on plasma lipid concentrations and other cardiometabolic risk factors. We evaluated male (n = 8) and female (n = 11) African green monkeys (vervets; Chlorocebus aethiops sabaeus) that initially were fed a standard diet. Each cohort then was divided into 2 groups, which received either standard chow or the Western diet. Food consumption and fecal quality were measured weekly. Body weight, waist circumference, and body-mass index were measured every 2 wk. CBC and clinical chemistry analyses were performed at baseline and 4 wk after the diet change. Plasma lipid concentrations, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, insulin, and fructosamine were measured at baseline and at 4, 8, and 12 wk after the diet change. Isoflavones were measured in the male monkeys at 6 wk after diet change, and lipid particle size was measured in the female monkeys at the 12-wk point. Green monkeys readily ate the Western diet and maintained baseline body weight and morphometric measures, with no adverse effects on fecal quality or clinical measures. Total plasma cholesterol was higher in monkeys fed the Western diet compared with standard chow. Isoflavones were higher in male monkeys fed standard chow compared with the Western diet, but lipid particle size did not differ by diet in female monkeys. Our data indicate that the Western diet led to changes in various biomedical risk factors of green monkeys to become similar to those of humans in the United States.

Manipulating membrane lipid profiles to restore T-cell function in autoimmunity.

PubMed

Waddington, Kirsty E; Jury, Elizabeth C

2015-08-01

Plasma membrane lipid rafts are heterogeneous cholesterol and glycosphingolipid (GSL)-enriched microdomains, within which the tight packing of cholesterol with the saturated-acyl chains of GSLs creates a region of liquid-order relative to the surrounding disordered membrane. Thus lipid rafts govern the lateral mobility and interaction of membrane proteins and regulate a plethora of signal transduction events, including T-cell antigen receptor (TCR) signalling. The pathways regulating homoeostasis of membrane cholesterol and GSLs are tightly controlled and alteration of these metabolic processes coincides with immune cell dysfunction as is evident in atherosclerosis, cancer and autoimmunity. Indeed, membrane lipid composition is emerging as an important factor influencing the ability of cells to respond appropriately to microenvironmental stimuli. Consequently, there is increasing interest in targeting membrane lipids or their metabolic control as a novel therapeutic approach to modulate immune cell behaviour and our recent work demonstrates that this is a promising strategy in T-cells from patients with the autoimmune disease systemic lupus erythematosus (SLE). © 2015 Authors; published by Portland Press Limited.

Effects of retinoids on differentiation, lipid metabolism, epidermal growth factor, and low-density lipoprotein binding in squamous carcinoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ponec, M.; Weerheim, A.; Havekes, L.

The relationship among keratinocyte differentiation capacity, lipid synthesis, low-density lipoprotein (LDL) metabolism, plasma membrane composition, and epidermal growth factor (EGF) binding has been studied in SCC-12F2 cells. The differentiation capacity of the cells, i.e., ionophore-induced cornified envelope formation, was inhibited by various retinoids and stimulated by hydrocortisone. Retinoids that caused a significant reduction of cornified envelope formation, i.e., retinoic acid and 13-cis-retinoic acid, caused only minor changes in lipid synthesis and plasma membrane composition. Arotinoid ethylsulfone, having a minor effect on cornified envelope formation, caused a drastic inhibition of cholesterol synthesis resulting in changes in the plasma membrane composition. Hydrocortisonemore » stimulated cornified envelope formation but had only minor effects on lipid synthesis and plasma membrane composition. Of all retinoids tested, only arotinoid ethylsulfone caused a drastic increase in EGF binding, while hydrocortisone had no effect. These results clearly demonstrate that the plasma membrane composition is not related to keratinocyte differentiation capacity, but most likely does determine EGF binding. Furthermore, EGF binding does not determine keratinocyte differentiation capacity.« less

Lipid and Creatinine Adjustment to Evaluate Health Effects of Environmental Exposures.

PubMed

O'Brien, Katie M; Upson, Kristen; Buckley, Jessie P

2017-03-01

Urine- and serum-based biomarkers are useful for assessing individuals' exposure to environmental factors. However, variations in urinary creatinine (a measure of dilution) or serum lipid levels, if not adequately corrected for, can directly impact biomarker concentrations and bias exposure-disease association measures. Recent methodological literature has considered the complex relationships between creatinine or serum lipid levels, exposure biomarkers, outcomes, and other potentially relevant factors using directed acyclic graphs and simulation studies. The optimal measures of urinary dilution and serum lipids have also been investigated. Existing evidence supports the use of covariate-adjusted standardization plus creatinine adjustment for urinary biomarkers and standardization plus serum lipid adjustment for lipophilic, serum-based biomarkers. It is unclear which urinary dilution measure is best, but all serum lipid measures performed similarly. Future research should assess methods for pooled biomarkers and for studying diseases and exposures that affect creatinine or serum lipids directly.

Omega-3 fatty acids, lipids, and apoE lipidation in Alzheimer's disease: a rationale for multi-nutrient dementia prevention.

PubMed

Grimm, Marcus O W; Michaelson, Daniel M; Hartmann, Tobias

2017-11-01

In the last decade, it has become obvious that Alzheimer's disease (AD) is closely linked to changes in lipids or lipid metabolism. One of the main pathological hallmarks of AD is amyloid-β (Aβ) deposition. Aβ is derived from sequential proteolytic processing of the amyloid precursor protein (APP). Interestingly, both, the APP and all APP secretases are transmembrane proteins that cleave APP close to and in the lipid bilayer. Moreover, apoE4 has been identified as the most prevalent genetic risk factor for AD. ApoE is the main lipoprotein in the brain, which has an abundant role in the transport of lipids and brain lipid metabolism. Several lipidomic approaches revealed changes in the lipid levels of cerebrospinal fluid or in post mortem AD brains. Here, we review the impact of apoE and lipids in AD, focusing on the major brain lipid classes, sphingomyelin, plasmalogens, gangliosides, sulfatides, DHA, and EPA, as well as on lipid signaling molecules, like ceramide and sphingosine-1-phosphate. As nutritional approaches showed limited beneficial effects in clinical studies, the opportunities of combining different supplements in multi-nutritional approaches are discussed and summarized. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

Membrane re-modelling by BAR domain superfamily proteins via molecular and non-molecular factors.

PubMed

Nishimura, Tamako; Morone, Nobuhiro; Suetsugu, Shiro

2018-04-17

Lipid membranes are structural components of cell surfaces and intracellular organelles. Alterations in lipid membrane shape are accompanied by numerous cellular functions, including endocytosis, intracellular transport, and cell migration. Proteins containing Bin-Amphiphysin-Rvs (BAR) domains (BAR proteins) are unique, because their structures correspond to the membrane curvature, that is, the shape of the lipid membrane. BAR proteins present at high concentration determine the shape of the membrane, because BAR domain oligomers function as scaffolds that mould the membrane. BAR proteins co-operate with various molecular and non-molecular factors. The molecular factors include cytoskeletal proteins such as the regulators of actin filaments and the membrane scission protein dynamin. Lipid composition, including saturated or unsaturated fatty acid tails of phospholipids, also affects the ability of BAR proteins to mould the membrane. Non-molecular factors include the external physical forces applied to the membrane, such as tension and friction. In this mini-review, we will discuss how the BAR proteins orchestrate membrane dynamics together with various molecular and non-molecular factors. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Associations between long chain polyunsaturated fatty acids and cardiovascular lipid risk factors in youth with type 1 diabetes: SEARCH Nutrition Ancillary Study.

PubMed

Couch, Sarah C; Crandell, Jamie; King, Irena; Peairs, Abigail; Shah, Amy S; Dolan, Lawrence M; Tooze, Janet; Crume, Tessa; Mayer-Davis, Elizabeth

2017-01-01

In this longitudinal study we explored the relationships between plasma n-3 and n-6 polyunsaturated fatty acids (PUFAs) and Δ5 and Δ6 desaturase activities (D5D and D6D, respectively) and fasting lipids in youth with type 1 diabetes (T1D). Incident cases of T1D in youth <20years of age who were seen for a baseline study visit (N=914) and a 1-year follow-up visit (N=416) were included. Fasting blood samples were obtained at each visit and plasma phospholipid n-6 PUFAs were measured, which included linoleic acid (LA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA); n-3 PUFAs included α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Estimated D5D and D6D were calculated as FA product-to-precursor ratios, where D5D=AA/DGLA and D6D=DGLA/LA. To examine the longitudinal relationships between long chain PUFAs, desaturase activities and fasting plasma lipids in youth with T1D mixed effects models were used for each individual PUFAs, D5D and D6D, adjusted for demographics, clinic site, diabetes duration, insulin regimen, insulin dose/kg, HbA1c, insulin sensitivity score, and body mass index with random effects to account for the repeated measurements. Favorable lipid associations were found between LA and low-density lipoprotein (LDL) cholesterol (β=-0.58, p<0.05); AA, plasma triglycerides (TG) (β=-0.04, p<0.05) and TG/high-density lipoprotein (HDL)-C ratio (β=-0.04, p<0.05); and D5D, plasma TG (β=-0.2, p<0.05) and TG/HDL-cholesterol ratio (β=-0.23, p<0.05). Findings were mixed for the n-3 PUFAs and DGLA: ALA was positively associated with plasma TG (β=0.33, p<0.05) and HDL cholesterol (β=9.86, p<0.05); EPA was positively associated with total cholesterol (β=8.17, p<0.05), LDL cholesterol (β=5.74, p<0.01) and HDL cholesterol (β=2.27, p<0.01); and DGLA was positively associated with TG/HDL-cholesterol ratio (β=0.05, P<0.05). Findings suggest that the most abundant PUFA, LA as well as its metabolic bi-product AA, may

The helix bundle: A reversible lipid binding motif

PubMed Central

Narayanaswami, Vasanthy; Kiss, Robert S.; Weers, Paul M.M.

2009-01-01

Apolipoproteins are the protein components of lipoproteins that have the innate ability to inter convert between a lipid-free and a lipid-bound form in a facile manner, a remarkable property conferred by the helix bundle motif. Composed of a series of four or five amphipathic α-helices that fold to form a helix bundle, this motif allows the en face orientation of the hydrophobic faces of the α-helices in the protein interior in the lipid-free state. A conformational switch then permits helix-helix interactions to be substituted by helix-lipid interactions upon lipid binding interaction. This review compares the apolipoprotein high resolution structures and the factors that trigger this switch in insect apolipophorin III and the mammalian apolipoproteins, apolipoprotein E and apolipoprotein A-I, pointing out the commonalities and key differences in the mode of lipid interaction. Further insights into the lipid bound conformation of apolipoproteins are required to fully understand their functional role under physiological conditions. PMID:19770066

Avanti lipid tools: connecting lipids, technology, and cell biology.

PubMed

Sims, Kacee H; Tytler, Ewan M; Tipton, John; Hill, Kasey L; Burgess, Stephen W; Shaw, Walter A

2014-08-01

Lipid research is challenging owing to the complexity and diversity of the lipidome. Here we review a set of experimental tools developed for the seasoned lipid researcher, as well as, those who are new to the field of lipid research. Novel tools for probing protein-lipid interactions, applications for lipid binding antibodies, enhanced systems for the cellular delivery of lipids, improved visualization of lipid membranes using gold-labeled lipids, and advances in mass spectrometric analysis techniques will be discussed. Because lipid mediators are known to participate in a host of signal transduction and trafficking pathways within the cell, a comprehensive lipid toolbox that aids the science of lipidomics research is essential to better understand the molecular mechanisms of interactions between cellular components. This article is part of a Special Issue entitled Tools to study lipid functions. Copyright © 2014. Published by Elsevier B.V.

Lipid partitioning in maize (Zea mays L.) endosperm highlights relationships among starch lipids, amylose, and vitreousness.

PubMed

Gayral, Mathieu; Bakan, Bénédicte; Dalgalarrondo, Michele; Elmorjani, Khalil; Delluc, Caroline; Brunet, Sylvie; Linossier, Laurent; Morel, Marie-Hélène; Marion, Didier

2015-04-08

Content and composition of maize endosperm lipids and their partition in the floury and vitreous regions were determined for a set of inbred lines. Neutral lipids, i.e., triglycerides and free fatty acids, accounted for more than 80% of endosperm lipids and are almost 2 times higher in the floury than in the vitreous regions. The composition of endosperm lipids, including their fatty acid unsaturation levels, as well as their distribution may be related to metabolic specificities of the floury and vitreous regions in carbon and nitrogen storage and to the management of stress responses during endosperm cell development. Remarkably, the highest contents of starch lipids were observed systematically within the vitreous endosperm. These high amounts of starch lipids were mainly due to lysophosphatidylcholine and were tightly linked to the highest amylose content. Consequently, the formation of amylose-lysophosphatidylcholine complexes has to be considered as an outstanding mechanism affecting endosperm vitreousness.

The TULIP superfamily of eukaryotic lipid-binding proteins as a mediator of lipid sensing and transport.

PubMed

Alva, Vikram; Lupas, Andrei N

2016-08-01

The tubular lipid-binding (TULIP) superfamily has emerged in recent years as a major mediator of lipid sensing and transport in eukaryotes. It currently encompasses three protein families, SMP-like, BPI-like, and Takeout-like, which share a common fold. This fold consists of a long helix wrapped in a highly curved anti-parallel β-sheet, enclosing a central, lipophilic cavity. The SMP-like proteins, which include subunits of the ERMES complex and the extended synaptotagmins (E-Syts), appear to be mainly located at membrane contacts sites (MCSs) between organelles, mediating inter-organelle lipid exchange. The BPI-like proteins, which include the bactericidal/permeability-increasing protein (BPI), the LPS (lipopolysaccharide)-binding protein (LBP), the cholesteryl ester transfer protein (CETP), and the phospholipid transfer protein (PLTP), are either involved in innate immunity against bacteria through their ability to sense lipopolysaccharides, as is the case for BPI and LBP, or in lipid exchange between lipoprotein particles, as is the case for CETP and PLTP. The Takeout-like proteins, which are comprised of insect juvenile hormone-binding proteins and arthropod allergens, transport, where known, lipid hormones to target tissues during insect development. In all cases, the activity of these proteins is underpinned by their ability to bind large, hydrophobic ligands in their central cavity and segregate them away from the aqueous environment. Furthermore, where they are involved in lipid exchange, recent structural studies have highlighted their ability to establish lipophilic, tubular channels, either between organelles in the case of SMP domains or between lipoprotein particles in the case of CETP. Here, we review the current knowledge on the structure, versatile functions, and evolution of the TULIP superfamily. We propose a deep evolutionary split in this superfamily, predating the Last Eukaryotic Common Ancestor, between the SMP-like proteins, which act on

Lipid profile in oral submucous fibrosis.

PubMed

Mehrotra, Ravi; Pandya, Shruti; Chaudhary, Ajay Kumar; Singh, Himanshu Pratap; Jaiswal, Ritesh Kumar; Singh, Mangal; Gupta, S C; Singh, Mamta

2009-07-24

Changes in lipid profile have long been associated with malignancies as lipids play a key role in maintenance of cell integrity. This study evaluated the alterations in extended lipid profile in untreated patients of oral submucous fibrosis (OSMF) and studied the correlation between lipid levels with tobacco consumption. In this hospital-based study, 65 clinically diagnosed and histopathologically proven patients of OSMF and 42 age and sex matched controls were studied. In these samples serum lipids including: (i) Total cholesterol, (ii) LDL cholesterol (LDLC), (iii) HDL cholesterol (HDLC) (iv) VLDL cholesterol (VLDLC) (v) triglycerides (vi) Apo-A1 (viii) Apo-B and (viii) LPa were analyzed. A significant decrease in plasma total cholesterol, HDLC and Apo-A1 was observed in patients with OSMF as compared to the controls. Thus an inverse relationship between plasma lipid levels and patients was found in OSMF. The lower levels of plasma cholesterol and other lipid constituents in patients might be due to their increased utilization. The findings strongly warrant an in-depth study of alterations in plasma lipid profile in patients with oral precancerous conditions.

[Factors affecting the control of blood pressure and lipid levels in patients with cardiovascular disease: the PREseAP Study].

PubMed

Orozco-Beltrán, Domingo; Brotons, Carlos; Moral, Irene; Soriano, Nuria; Del Valle, María A; Rodríguez, Ana I; Pepió, Josep M; Pastor, Ana

2008-03-01

The aim of this observational study was to identify factors influencing the control of blood pressure (i.e., <140/90 mmHg, or <130/80 mmHg in diabetic patients) and low-density lipoprotein (LDL) cholesterol level (<100 mg/dL) in 1223 patients with cardiovascular disease. Overall, 70.2% of patients were men, and their mean age was 66.4 years. Blood pressure was poorly controlled in 50.9% (95% confidence interval [CI], 46.9%-54.8%) and the LDL cholesterol level was poorly controlled in 60.1% (95% CI, 56.3%-63.9%). Determinants of poor blood pressure control were diabetes, hypertension, no previous diagnosis of heart failure, previous diagnosis of peripheral artery disease or stroke, obesity, and no lipid-lowering treatment. Determinants of poor LDL cholesterol control were no lipid-lowering treatment, no previous diagnosis of ischemic heart disease, no antihypertensive treatment, and dyslipidemia. The factors affecting blood pressure control were different from those affecting LDL cholesterol control, an observation that should be taken into account when implementing treatment recommendations for achieving therapeutic objectives in secondary prevention.

Proton permeation of lipid bilayers.

PubMed

Deamer, D W

1987-10-01

Proton permeation of the lipid bilayer barrier has two unique features. First, permeability coefficients measured at neutral pH ranges are six to seven orders of magnitude greater than expected from knowledge of other monovalent cations. Second, proton conductance across planar lipid bilayers varies at most by a factor of 10 when pH is varied from near 1 to near 11. Two mechanisms have been proposed to account for this anomalous behavior: proton conductance related to contaminants of lipid bilayers, and proton translocation along transient hydrogen-bonded chains (tHBC) of associated water molecules in the membrane. The weight of evidence suggests that trace contaminants may contribute to proton conductance across planar lipid membranes at certain pH ranges, but cannot account for the anomalous proton flux in liposome systems. Two new results will be reported here which were designed to test the tHBC model. These include measurements of relative proton/potassium permeability in the gramicidin channel, and plots of proton flux against the magnitude of pH gradients. (1) The relative permeabilities of protons and potassium through the gramicidin channel, which contains a single strand of hydrogen-bonded water molecules, were found to differ by at least four orders of magnitude when measured at neutral pH ranges. This result demonstrates that a hydrogen-bonded chain of water molecules can provide substantial discrimination between protons and other cations. It was also possible to calculate that if approximately 7% of bilayer water was present in a transient configuration similar to that of the gramicidin channel, it could account for the measured proton flux. (2) The plot of proton conductance against pH gradient across liposome membranes was superlinear, a result that is consistent with one of three alternative tHBC models for proton conductance described by Nagle elsewhere in this volume.

Comparison of pinniped and cetacean prey tissue lipids with lipids of their elasmobranch predator.

PubMed

Davidson, Bruce; Cliff, Geremy

2014-01-01

The great white shark is known to include pinnipeds and cetaceans in its diet. Both groups of marine mammals deposit thick blubber layers around their bodies. Elasmobranchs do not produce adipose tissue, but rather store lipid in their livers, thus a great white predating on a marine mammal will deposit the lipids in its liver until required. Samples from great white liver and muscle, Cape fur seal, Indian Ocean bottlenose dolphin and common dolphin liver, muscle and blubber were analyzed for their lipid and fatty acid profiles. The great white liver and marine mammal blubber samples showed a considerable degree of homogeneity, but there were significant differences when comparing between the muscle samples. Blubber from all three marine mammal species was calculated to provide greater than 95% of lipid intake for the great white shark from the tissues analyzed. Sampling of prey blubber may give a good indication of the lipids provided to the shark predator.

Zinc-α2-glycoprotein, a lipid mobilizing factor, is expressed in adipocytes and is up-regulated in mice with cancer cachexia

PubMed Central

Bing, Chen; Bao, Yi; Jenkins, John; Sanders, Paul; Manieri, Monia; Cinti, Saverio; Tisdale, Michael J.; Trayhurn, Paul

2004-01-01

Zinc-α2-glycoprotein (ZAG), a 43-kDa protein, is overexpressed in certain human malignant tumors and acts as a lipid-mobilizing factor to stimulate lipolysis in adipocytes leading to cachexia in mice implanted with ZAG-producing tumors. Because white adipose tissue (WAT) is an endocrine organ secreting a wide range of protein factors, including those involved in lipid metabolism, we have investigated whether ZAG is produced locally by adipocytes. ZAG mRNA was detected by RT-PCR in the mouse WAT depots examined (epididymal, perirenal, s.c., and mammary gland) and in interscapular brown fat. In WAT, ZAG gene expression was evident in mature adipocytes and in stromal-vascular cells. Using a ZAG Ab, ZAG protein was located in WAT by Western blotting and immunohistochemistry. Mice bearing the MAC16-tumor displayed substantial losses of body weight and fat mass, which was accompanied by major increases in ZAG mRNA and protein levels in WAT and brown fat. ZAG mRNA was detected in 3T3-L1 cells, before and after the induction of differentiation, with the level increasing progressively after differentiation with a peak at days 8–10. Both dexamethasone and a β3 agonist, BRL 37344, increased ZAG mRNA levels in 3T3-L1 adipocytes. ZAG gene expression and protein were also detected in human adipose tissue (visceral and s.c.). It is suggested that ZAG is a new adipose tissue protein factor, which may be involved in the modulation of lipolysis in adipocytes. Overexpression in WAT of tumor-bearing mice suggests a local role for adipocyte-derived ZAG in the substantial reduction of adiposity of cancer cachexia. PMID:14983038

Neuroimaging of Lipid Storage Disorders

ERIC Educational Resources Information Center

Rieger, Deborah; Auerbach, Sarah; Robinson, Paul; Gropman, Andrea

2013-01-01

Lipid storage diseases, also known as the lipidoses, are a group of inherited metabolic disorders in which there is lipid accumulation in various cell types, including the central nervous system, because of the deficiency of a variety of enzymes. Over time, excessive storage can cause permanent cellular and tissue damage. The brain is particularly…

What are the effects of psychological stress and physical work on blood lipid profiles?

PubMed

Assadi, Seyedeh Negar

2017-05-01

Blood lipids disorders are prevalent in the world. Some of their risk factors are modifiable such as mental and physical stress which existed in some places such as work environment.Objective of this study was to determine the effects of psychological and physical stress on the lipid profiles. It was a historical cohort study. The people who were employed as general worker were participated. The study was conducted with flexible interview for getting history, lipid profile examination, and a checklist including occupational and nonoccupational risk factors and using the health issues. According to the type of stress exposures, the study population was divided into 5 groups. Groups were followed for lipid profiles. These groups were exposed to psychological stress, physical stress or both of them; mild psychological stress (group 1), mild physical work without psychological stress (group 2), mild psychological stress and mild physical work (group 3), moderate physical work without psychological stress (group 4), and heavy physical work without psychological stress (group 5). Data were analyzed with SPSS 16. ANOVA, χ, and exact test were calculated with considering P < .05 as significant level. Relative risks were calculated with confidence interval 95%. The means of lipid profiles were in normal ranges. The relative risks for triglycerides more than 200 mg/dL was 1.57 (1.02-2.42) and low density lipoprotein (LDL) more than 130 mg/dL was 14.54 (3.54-59.65) in group 1. The relative risks for high density lipoprotein (HDL) less than 45 mg/dL was 14.61 (8.31-25.68) in group 1 and 16.00 (8.30-30.83) in group 3. After multinomial logistic regression they had significant differences. Psychological stress was a risk factor for lipid disorders, and suitable physical activity was protective in this situation.

Spontaneous charged lipid transfer between lipid vesicles.

PubMed

Richens, Joanna L; Tyler, Arwen I I; Barriga, Hanna M G; Bramble, Jonathan P; Law, Robert V; Brooks, Nicholas J; Seddon, John M; Ces, Oscar; O'Shea, Paul

2017-10-03

An assay to study the spontaneous charged lipid transfer between lipid vesicles is described. A donor/acceptor vesicle system is employed, where neutrally charged acceptor vesicles are fluorescently labelled with the electrostatic membrane probe Fluoresceinphosphatidylethanolamine (FPE). Upon addition of charged donor vesicles, transfer of negatively charged lipid occurs, resulting in a fluorescently detectable change in the membrane potential of the acceptor vesicles. Using this approach we have studied the transfer properties of a range of lipids, varying both the headgroup and the chain length. At the low vesicle concentrations chosen, the transfer follows a first-order process where lipid monomers are transferred presumably through the aqueous solution phase from donor to acceptor vesicle. The rate of transfer decreases with increasing chain length which is consistent with energy models previously reported for lipid monomer vesicle interactions. Our assay improves on existing methods allowing the study of a range of unmodified lipids, continuous monitoring of transfer and simplified experimental procedures.

Lipid and Creatinine Adjustment to Evaluate Health Effects of Environmental Exposures

PubMed Central

O’Brien, Katie M.; Upson, Kristen; Buckley, Jessie P.

2017-01-01

Purpose of review Urine- and serum-based biomarkers are useful for assessing individuals’ exposure to environmental factors. However, variations in urinary creatinine (a measure of dilution) or serum lipid levels, if not adequately corrected for, can directly impact biomarker concentrations and bias exposure-disease association measures. Recent findings Recent methodological literature has considered the complex relationships between creatinine or serum lipid levels, exposure biomarkers, outcomes, and other potentially relevant factors using directed acyclic graphs and simulation studies. The optimal measures of urinary dilution and serum lipids have also been investigated. Summary Existing evidence supports the use of covariate-adjusted standardization plus creatinine adjustment for urinary biomarkers and standardization plus serum lipid adjustment for lipophilic, serum-based biomarkers. It is unclear which urinary dilution measure is best, but all serum lipid measures performed similarly. Future research should assess methods for pooled biomarkers and for studying diseases and exposures that affect creatinine or serum lipids directly. PMID:28097619

Lipid-lowering nutraceuticals in clinical practice: position paper from an International Lipid Expert Panel.

PubMed

Cicero, Arrigo F G; Colletti, Alessandro; Bajraktari, Gani; Descamps, Olivier; Djuric, Dragan M; Ezhov, Marat; Fras, Zlatko; Katsiki, Niki; Langlois, Michel; Latkovskis, Gustavs; Panagiotakos, Demosthenes B; Paragh, Gyorgy; Mikhailidis, Dimitri P; Mitchenko, Olena; Paulweber, Bernhard; Pella, Daniel; Pitsavos, Christos; Reiner, Željko; Ray, Kausik K; Rizzo, Manfredi; Sahebkar, Amirhossein; Serban, Maria-Corina; Sperling, Laurence S; Toth, Peter P; Vinereanu, Dragos; Vrablík, Michal; Wong, Nathan D; Banach, Maciej

2017-09-01

In recent years, there has been growing interest in the possible use of nutraceuticals to improve and optimize dyslipidemia control and therapy. Based on the data from available studies, nutraceuticals might help patients obtain theraputic lipid goals and reduce cardiovascular residual risk. Some nutraceuticals have essential lipid-lowering properties confirmed in studies; some might also have possible positive effects on nonlipid cardiovascular risk factors and have been shown to improve early markers of vascular health such as endothelial function and pulse wave velocity. However, the clinical evidence supporting the use of a single lipid-lowering nutraceutical or a combination of them is largely variable and, for many of the nutraceuticals, the evidence is very limited and, therefore, often debatable. The purpose of this position paper is to provide consensus-based recommendations for the optimal use of lipid-lowering nutraceuticals to manage dyslipidemia in patients who are still not on statin therapy, patients who are on statin or combination therapy but have not achieved lipid goals, and patients with statin intolerance. This statement is intended for physicians and other healthcare professionals engaged in the diagnosis and management of patients with lipid disorders, especially in the primary care setting. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Proteomic analysis of BmN cell lipid rafts reveals roles in Bombyx mori nucleopolyhedrovirus infection.

PubMed

Hu, Xiaolong; Zhu, Min; Liang, Zi; Kumar, Dhiraj; Chen, Fei; Zhu, Liyuan; Kuang, Sulan; Xue, Renyu; Cao, Guangli; Gong, Chengliang

2017-04-01

The mechanism of how Bombyx mori nucleopolyhedrovirus (BmNPV) enters cells is unknown. The primary components of membrane lipid rafts are proteins and cholesterol, and membrane lipid rafts are thought to be an active region for host-viral interactions. However, whether they contribute to the entry of BmNPV into silkworm cells remains unclear. In this study, we explored the membrane protein components of lipid rafts from BmN cells with mass spectrometry (MS). Proteins and cholesterol were investigated after establishing infection with BmNPV in BmN cells. In total, 222 proteins were identified in the lipid rafts, and Gene Ontology (GO) annotation analysis showed that more than 10% of these proteins had binding and catalytic functions. We then identified proteins that potentially interact between lipid rafts and BmNPV virions using the Virus Overlay Protein Blot Assay (VOPBA). A total of 65 proteins were analyzed with MS, and 7 were predicted to be binding proteins involved in BmNPV cellular invasion, including actin, kinesin light chain-like isoform X2, annexin B13, heat-shock protein 90, barrier-to-autointegration factor B-like and serine/arginine-rich splicing factor 1 A-like. When the cholesterol of the lipid rafts from the membrane was depleted by methyl-β-cyclodextrin (MβCD), BmNPV entry into BmN cells was blocked. However, supplying cholesterol into the medium rescued the BmNPV infection ability. These results show that membrane lipid rafts may be the active regions for the entry of BmNPV into cells, and the components of membrane lipid rafts may be candidate targets for improving the resistance of the silkworm to BmNPV.

Association between Carbohydrate Intake and Serum Lipids

PubMed Central

Ma, Yunsheng; Chiriboga, David E.; Olendzki, Barbara C.; Li, Wenjun; Leung, Katherine; Hafner, Andrea R.; Li, Youfu; Ockene, Ira S.; Hebert, James R.

2006-01-01

Background The effect of dietary carbohydrate on blood lipids has received considerable attention in light of the current trend in lowering carbohydrate intake for weight loss. Objectives To evaluate the association between carbohydrate intake and serum lipids. Methods Blood samples and 24-hour dietary and physical activity recall interviews were obtained from each subject at quarterly intervals for five consecutive quarters between 1994 and 1998 from 574 healthy adults in Central Massachusetts. Relationships between serum lipids and dietary carbohydrate factors were assessed using linear mixed models and adjusting for other risk factors known to be related to blood lipids. Both cross-sectional and longitudinal results were reported. Results Cross-sectional analysis results from this study suggest that higher total carbohydrate intake, percentage of calories from carbohydrate, glycemic index (GI) and/or glycemic load (GL) are related to lower high-density lipoprotein cholesterol (HDL-C) and higher serum triacylglycerol levels, while higher total carbohydrate intake and/or GL are related to lower total and low-density lipoprotein cholesterol (LDL-C) levels. In a one-year longitudinal analysis, GL was positively associated with total and LDL-C levels, and there was an inverse association between percentage of calories from carbohydrate and HDL-C levels. Conclusions Results suggest that there is a complex and predominantly unfavorable effect of increased intake of highly processed carbohydrate on lipid profile, which may have implications for metabolic syndrome, diabetes, and coronary heart disease. Further studies in the form of randomized controlled trials are required to investigate these associations and determine the implications for lipid management. PMID:16582033

Integrated analysis of transcriptome and lipid profiling reveals the co-influences of inositol-choline and Snf1 in controlling lipid biosynthesis in yeast.

PubMed

Chumnanpuen, Pramote; Zhang, Jie; Nookaew, Intawat; Nielsen, Jens

2012-07-01

In the yeast Saccharomyces cerevisiae many genes involved in lipid biosynthesis are transcriptionally controlled by inositol-choline and the protein kinase Snf1. Here we undertook a global study on how inositol-choline and Snf1 interact in controlling lipid metabolism in yeast. Using both a reference strain (CEN.PK113-7D) and a snf1Δ strain cultured at different nutrient limitations (carbon and nitrogen), at a fixed specific growth rate of 0.1 h(-1), and at different inositol choline concentrations, we quantified the expression of genes involved in lipid biosynthesis and the fluxes towards the different lipid components. Through integrated analysis of the transcriptome, the lipid profiling and the fluxome, it was possible to obtain a high quality, large-scale dataset that could be used to identify correlations and associations between the different components. At the transcription level, Snf1 and inositol-choline interact either directly through the main phospholipid-involving transcription factors (i.e. Ino2, Ino4, and Opi1) or through other transcription factors e.g. Gis1, Mga2, and Hac1. However, there seems to be flux regulation at the enzyme levels of several lipid involving enzymes. The analysis showed the strength of using both transcriptome and lipid profiling analysis for mapping the co-influence of inositol-choline and Snf1 on phospholipid metabolism.

Method of fabricating lipid bilayer membranes on solid supports

NASA Technical Reports Server (NTRS)

Cho, Nam-Joon (Inventor); Frank, Curtis W. (Inventor); Glenn, Jeffrey S. (Inventor); Cheong, Kwang Ho (Inventor)

2012-01-01

The present invention provides a method of producing a planar lipid bilayer on a solid support. With this method, a solution of lipid vesicles is first deposited on the solid support. Next, the lipid vesicles are destabilized by adding an amphipathic peptide solution to the lipid vesicle solution. This destabilization leads to production of a planar lipid bilayer on the solid support. The present invention also provides a supported planar lipid bilayer, where the planar lipid bilayer is made of naturally occurring lipids and the solid support is made of unmodified gold or titanium oxide. Preferably, the supported planar lipid bilayer is continuous. The planar lipid bilayer may be made of any naturally occurring lipid or mixture of lipids, including, but not limited to phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinsitol, cardiolipin, cholesterol, and sphingomyelin.

Lipid chain geometry of C14 glycerol-based lipids: effect on lipoplex structure and transfection.

PubMed

Kudsiova, Laila; Ho, Jimmy; Fridrich, Barbara; Harvey, Richard; Keppler, Melanie; Ng, Tony; Hart, Stephen L; Tabor, Alethea B; Hailes, Helen C; Lawrence, M Jayne

2011-02-01

The effects have been determined of a systematic alteration of the alkyl chain geometry of a C14 analogue of DOTMA on the detailed molecular architecture of the resulting cationic vesicles formed both in the absence and presence of 50 mol% DOPE, and of the lipoplexes prepared from these vesicles using either calf thymus or plasmid DNA. The C14 DOTMA analogues studied involved cis- or trans-double bonds at positions Δ9 or Δ11, and a compound (ALK) featuring an alkyne at position C9. For all of these analogues, examination by light scattering and neutron scattering, zeta potential measurement, and negative staining electron microscopy showed that there were no significant differences in the structures or charges of the vesicles or of the resulting lipoplexes, regardless of the nature of the DNA incorporated. Differences were observed, however, between the complexes formed by the various lipids when examining the extent of complexation and release by gel electrophoresis, where the E-lipids appeared to complex the DNA more efficiently than all other lipids tested. Moreover, the lipoplexes prepared from the E-lipids were the most effective in transfection of MDA-MB-231 breast cancer cells. As indicated through confocal microscopy studies, the E-lipids also showed a higher internalisation capacity and a more diffuse cellular distribution, possibly indicating a greater degree of endosomal escape and/or nuclear import. These observations suggest that the extent of complexation is the most important factor in determining the transfection efficiency of the complexes tested. At present it is unclear why the E-lipids were more effective at complexing DNA, although it is thought that the effective area per molecule occupied by the cationic lipid and DOPE head groups, and therefore the density of positive charges on the surface of the bilayer most closely matches the negative charge density of the DNA molecule. From a consideration of the geometry of the cationic lipids it is

Homogenization of the lipid profile values.

PubMed

Pedro-Botet, Juan; Rodríguez-Padial, Luis; Brotons, Carlos; Esteban-Salán, Margarita; García-Lerín, Aurora; Pintó, Xavier; Lekuona, Iñaki; Ordóñez-Llanos, Jordi

Analytical reports from the clinical laboratory are essential to guide clinicians about what lipid profile values should be considered altered and, therefore, require intervention. Unfortunately, there is a great heterogeneity in the lipid values reported as "normal, desirable, recommended or referenced" by clinical laboratories. This can difficult clinical decisions and be a barrier to achieve the therapeutic goals for cardiovascular prevention. A recent international recommendation has added a new heterogeneity factor for the interpretation of lipid profile, such as the possibility of measuring it without previous fasting. All this justifies the need to develop a document that adapts the existing knowledge to the clinical practice of our health system. In this regard, professionals from different scientific societies involved in the measurement and use of lipid profile data have developed this document to establish recommendations that facilitate their homogenization. Copyright © 2017. Publicado por Elsevier España, S.L.U.

[Study on the dynamic variations and influencing factors of serum lipid levels during pregnancy and postpartum].

PubMed

Xu, D; Liang, C; Chen, L; Wu, X D; He, J

2018-04-25

Objective: To study the variations and influencing factors of serum triglycerides and cholesterol levels during pregnancy and postpartum. Methods: A retrospective study was performed among 5 020 healthy singleton (95.10%, 4 774/5 020) and twin (4.90%, 246/5 020) women who had delivery in Women's Hospital, Zhejiang University School of Medicine from January 2011 to December 2016. Serum triglycerides and cholesterol levels during pregnancy and postpartum of all the cases were collected. Both singleton and twin pregnant women were divided into advanced age and appropriate age groups, and then data of serum sample were assigned to 3 groups according to the gestation weeks, which were second trimester pregnancy (24-28 gestation weeks) , third trimester pregnancy (32-41 gestation weeks) and postpartum (within 72 hours after delivery) . The serum triglycerides and cholesterol levels in each groups were compared. Results: (1) Serum triglycerides and cholesterol levels during the second trimester pregnancy, third trimester pregnancy and postpartum were higher than levels of non-pregnancy in both singleton and twin groups (all P< 0.05) . (2) Serum triglycerides and cholesterol levels in the third trimester pregnancy group were higher than those of second trimester pregnancy group in both advanced age and appropriate aged women regardless singleton or twin pregnancy (all P< 0.05) . The 95% CI of serum lipid levels in each group during second and third trimester pregnancy were as follows: in appropriate aged singleton group, the triglycerides levels were 1.07-4.13 and 1.52-7.21 mmol/L, and the cholesterol levels were 2.77-12.11 and 4.44-9.36 mmol/L. In advanced aged singleton group, the triglycerides levels were 1.28-4.61 and 1.70-7.80 mmol/L, and the cholesterol levels were 4.35-8.40 and 4.46-9.35 mmol/L; in appropriate aged twin group, the triglycerides levels were 1.39-7.16 and 1.90-9.29 mmol/L, and the cholesterol levels were 4.99-12.16 and 4.52-10.07 mmol/L; in advanced

Lipid Storage Diseases

MedlinePlus

... Neurological Disorders and Stroke (NINDS) is to seek fundamental knowledge about the brain and nervous system and ... some of the major challenges in the diagnosis, management, and therapy of rare diseases, including the lipid ...

Lipid regulatory genes polymorphism in children with and without obesity and cardiometabolic risk factors: The CASPIAN-III study

PubMed Central

Hovsepian, Silva; Javanmard, Shaghayegh Haghjooy; Mansourian, Marjan; Hashemipour, Mahin; Tajadini, Mohamadhasan; Kelishadi, Roya

2018-01-01

Background: Genetically, predisposed children are considered as at-risk individuals for cardiovascular disease. In this study, we aimed to compare the frequency of four-lipid regulatory polymorphism in obese and normal-weight children with and without cardiometabolic risk factors. Materials and Methods: In this nested case–control study, 600 samples of four groups of participants consisted of those with normal weight with and without cardiometabolic risk factors and obese with and without cardiometabolic risk factors. Allelic and genotypic frequencies of GCKR (rs780094), GCKR (rs1260333), MLXIPL (rs3812316), and FADS (rs174547) polymorphisms were compared in the four studied groups. Results: Data of 528 samples were complete and included in this study. The mean (standard deviation) age of participants was 15.01 (2.21) years. Frequency of tt allele (minor allele) of GCKR (rs1260333) polymorphism was significantly lower in normal weight metabolically healthy participants than metabolically unhealthy normal weight (MUHNW) and obese children with and without cardiometabolic risk factor (P = 0.01). Frequency of ga allele of GCKR (rs780094) polymorphism was significantly higher in normal weight children with cardiometabolic risk factor than in their obese counterparts with cardiometabolic risk factor (P = 0.04). Frequency of cg and gg alleles (minor type) of MLXIPL (rs3812316) polymorphism in normal weight metabolically healthy participants was significantly higher than MUHNW (P = 0.04) and metabolically healthy obese children (P = 0.04). Conclusion: The findings of our study indicated that the minor allele of GCKR (rs1260333) single nucleotide polymorphisms (SNPs) could have pathogenic effect for obesity and cardiometabolic risk factors. Ga allele of GCKR (rs780094) SNPs had a protective effect on obesity. Minor alleles of MLXIPL (rs3812316) could have a protective effect for obesity and cardiometabolic risk factors. PMID:29531563

Prenatal exposure to common environmental factors affects brain lipids and increases risk of developing autism spectrum disorders.

PubMed

Wong, Christine T; Wais, Joshua; Crawford, Dorota A

2015-11-01

The prevalence of autism spectrum disorders (ASDs) has been on the rise over recent years. The presence of diverse subsets of candidate genes in each individual with an ASD and the vast variability of phenotypical differences suggest that the interference of an exogenous environmental component may greatly contribute to the development of ASDs. The lipid mediator prostaglandin E2 (PGE2 ) is released from phospholipids of cell membranes, and is important in brain development and function; PGE2 is involved in differentiation, synaptic plasticity and calcium regulation. The previous review already described extrinsic factors, including deficient dietary supplementation, and exposure to oxidative stress, infections and inflammation that can disrupt signaling of the PGE2 pathway and contribute to ASDs. In this review, the structure and establishment of two key protective barriers for the brain during early development are described: the blood-brain barrier; and the placental barrier. Then, the first comprehensive summary of other environmental factors, such as exposure to chemicals in air pollution, pesticides and consumer products, which can also disturb PGE2 signaling and increase the risk for developing ASDs is provided. Also, how these exogenous agents are capable of crossing the protective barriers of the brain during critical developmental periods when barrier components are still being formed is described. This review underlines the importance of avoiding or limiting exposure to these factors during vulnerable periods in development. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Light intensity as major factor to maximize biomass and lipid productivity of Ettlia sp. in CO2-controlled photoautotrophic chemostat.

PubMed

Seo, Seong-Hyun; Ha, Ji-San; Yoo, Chan; Srivastava, Ankita; Ahn, Chi-Yong; Cho, Dae-Hyun; La, Hyun-Joon; Han, Myung-Soo; Oh, Hee-Mock

2017-11-01

The optimal culture conditions are critical factors for high microalgal biomass and lipid productivity. To optimize the photoautotrophic culture conditions, combination of the pH (regulated by CO 2 supply), dilution rate, and light intensity was systematically investigated for Ettlia sp. YC001 cultivation in a chemostat during 143days. The biomass productivity increased with the increase in dilution rate and light intensity, but decreased with increasing pH. The average lipid content was 19.8% and statistically non-variable among the tested conditions. The highest biomass and lipid productivities were 1.48gL -1 d -1 and 291.4mgL -1 d -1 with a pH of 6.5, dilution rate of 0.78d -1 , and light intensity of 1500μmolphotonsm -2 s -1 . With a sufficient supply of CO 2 and nutrients, the light intensity was the main determinant of the photosynthetic rate. Therefore, the surface-to-volume ratio of a photobioreactor should enable efficient light distribution to enhance microalgal growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

Salt modulates the stability and lipid binding affinity of the adipocyte lipid-binding proteins

NASA Technical Reports Server (NTRS)

Schoeffler, Allyn J.; Ruiz, Carmen R.; Joubert, Allison M.; Yang, Xuemei; LiCata, Vince J.

2003-01-01

Adipocyte lipid-binding protein (ALBP or aP2) is an intracellular fatty acid-binding protein that is found in adipocytes and macrophages and binds a large variety of intracellular lipids with high affinity. Although intracellular lipids are frequently charged, biochemical studies of lipid-binding proteins and their interactions often focus most heavily on the hydrophobic aspects of these proteins and their interactions. In this study, we have characterized the effects of KCl on the stability and lipid binding properties of ALBP. We find that added salt dramatically stabilizes ALBP, increasing its Delta G of unfolding by 3-5 kcal/mol. At 37 degrees C salt can more than double the stability of the protein. At the same time, salt inhibits the binding of the fluorescent lipid 1-anilinonaphthalene-8-sulfonate (ANS) to the protein and induces direct displacement of the lipid from the protein. Thermodynamic linkage analysis of the salt inhibition of ANS binding shows a nearly 1:1 reciprocal linkage: i.e. one ion is released from ALBP when ANS binds, and vice versa. Kinetic experiments show that salt reduces the rate of association between ANS and ALBP while simultaneously increasing the dissociation rate of ANS from the protein. We depict and discuss the thermodynamic linkages among stability, lipid binding, and salt effects for ALBP, including the use of these linkages to calculate the affinity of ANS for the denatured state of ALBP and its dependence on salt concentration. We also discuss the potential molecular origins and potential intracellular consequences of the demonstrated salt linkages to stability and lipid binding in ALBP.

Proteomic analysis of Chlorella vulgaris: Potential targets for enhanced lipid accumulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guarnieri, Michael T.; Nag, Ambarish; Yang, Shihui

2013-11-01

Oleaginous microalgae are capable of producing large quantities of fatty acids and triacylglycerides. As such, they are promising feedstocks for the production of biofuels and bioproducts. Genetic strain-engineering strategies offer a means to accelerate the commercialization of algal biofuels by improving the rate and total accumulation of microalgal lipids. However, the industrial potential of these organisms remains to be met, largely due to the incomplete knowledgebase surrounding the mechanisms governing the induction of algal lipid biosynthesis. Such strategies require further elucidation of genes and gene products controlling algal lipid accumulation. In this study, we have set out to examine thesemore » mechanisms and identify novel strain-engineering targets in the oleaginous microalga, Chlorella vulgaris. Comparative shotgun proteomic analyses have identified a number of novel targets, including previously unidentified transcription factors and proteins involved in cell signaling and cell cycle regulation. These results lay the foundation for strain-improvement strategies and demonstrate the power of translational proteomic analysis.« less

Lipidomic and proteomic analysis of Caenorhabditis elegans lipid droplets and identification of ACS-4 as a lipid droplet-associated protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vrablik, Tracy L.; Petyuk, Vladislav A.; Larson, Emily M.

2015-06-27

Lipid droplets are cytoplasmic organelles that store neutral lipids for membrane synthesis and energy reserves. In this study, we characterized the lipid and protein composition of purified C. elegans lipid droplets. These lipid droplets are composed mainly of triacylglycerols, surrounded by a phospholipid monolayer composed primarily of phosphatidylcholine and phosphatidylethanolamine. The fatty acid composition of the triacylglycerols was rich in fatty acid species obtained from the dietary E. coli, including cyclopropane fatty acids and cis-vaccenic acid. Unlike other organisms, C. elegans lipid droplets contain very little cholesterol or cholesterol esters. Comparison of the lipid droplet proteomes of wild type andmore » high-fat daf-2 mutant strains shows a relative decrease of MDT-28 abundance in lipid droplets isolated from daf-2 mutants. Functional analysis of lipid droplet proteins identified in our proteomic studies indicated an enrichment of proteins required for growth and fat homeostasis in C. elegans.« less

LipidFinder: A computational workflow for discovery of lipids identifies eicosanoid-phosphoinositides in platelets

PubMed Central

O’Connor, Anne; Brasher, Christopher J.; Slatter, David A.; Meckelmann, Sven W.; Hawksworth, Jade I.; Allen, Stuart M.; O’Donnell, Valerie B.

2017-01-01

Accurate and high-quality curation of lipidomic datasets generated from plasma, cells, or tissues is becoming essential for cell biology investigations and biomarker discovery for personalized medicine. However, a major challenge lies in removing artifacts otherwise mistakenly interpreted as real lipids from large mass spectrometry files (>60 K features), while retaining genuine ions in the dataset. This requires powerful informatics tools; however, available workflows have not been tailored specifically for lipidomics, particularly discovery research. We designed LipidFinder, an open-source Python workflow. An algorithm is included that optimizes analysis based on users’ own data, and outputs are screened against online databases and categorized into LIPID MAPS classes. LipidFinder outperformed three widely used metabolomics packages using data from human platelets. We show a family of three 12-hydroxyeicosatetraenoic acid phosphoinositides (16:0/, 18:1/, 18:0/12-HETE-PI) generated by thrombin-activated platelets, indicating crosstalk between eicosanoid and phosphoinositide pathways in human cells. The software is available on GitHub (https://github.com/cjbrasher/LipidFinder), with full userguides. PMID:28405621

The relationship between calcium intake, obesity, and cardiovascular disease risk factors: the jackson heart study

USDA-ARS?s Scientific Manuscript database

Cardiovascular disease (CVD) is a major health risk in the United States. Major indicators of CVD risk include obesity, blood lipids, and blood pressure. Modifiable risk factors associated with CVD include body composition (body mass index and waist circumference), serum lipids, and blood pressure. ...

α-Lipoic acid ameliorated oxidative stress induced by perilla oil, but the combination of these dietary factors was ineffective to cause marked deceases in serum lipid levels in rats.

PubMed

Ide, Takashi; Tanaka, Ai

2017-12-01

Dietary perilla oil rich in α-linolenic acid and α-lipoic acid lowers the serum lipid level through changes in hepatic fatty acid metabolism. We therefore hypothesized that the combination of these dietary factors may ameliorate lipid metabolism more than the factors individually. Moreover, α-lipoic acid exerts strong anti-oxidative activity. Hence, we also hypothesized that α-lipoic acid may attenuate perilla oil-mediated oxidative stress. We therefore studied the combined effects of perilla oil and α-lipoic acid on lipid metabolism and parameters of oxidative stress. Male rats were fed diets supplemented with 0 or 2.0 g/kg R-α-lipoic acid and containing 120 g/kg of palm (saturated fat), corn (linoleic acid), or perilla oil (α-linolenic acid) for 23 days. Perilla oil compared with other fats decreased serum lipid concentrations in rats fed α-lipoic acid-free diets; however, the combination of perilla oil with α-lipoic acid was ineffective for observing more marked decreases in serum lipid levels. Alterations in hepatic fatty acid synthesis and oxidation may account for the observed changes. Perilla oil, compared with palm and corn oils, strongly increased the malondialdehyde level in the serum and liver. α-Lipoic acid counteracted the increases in these parameters even though the effects were attenuated in the liver. α-Lipoic acid increased the parameters of the anti-oxidant system. The results suggested that α-lipoic acid can ameliorate oxidative stress induced by perilla oil, but the combination of these dietary factors was ineffective for additionally reducing serum lipid levels. Copyright © 2017 Elsevier Inc. All rights reserved.

A Genome Wide Association Study Identifies Common Variants Associated with Lipid Levels in the Chinese Population

PubMed Central

Wu, Chen; Yang, Handong; Yu, Dianke; Yang, Xiaobo; Zhang, Xiaomin; Wang, Yiqin; Sun, Jielin; Gao, Yong; Tan, Aihua; He, Yunfeng; Zhang, Haiying; Qin, Xue; Zhu, Jingwen; Li, Huaixing; Lin, Xu; Zhu, Jiang; Min, Xinwen; Lang, Mingjian; Li, Dongfeng; Zhai, Kan; Chang, Jiang; Tan, Wen; Yuan, Jing; Chen, Weihong; Wang, Youjie; Wei, Sheng; Miao, Xiaoping; Wang, Feng; Fang, Weimin; Liang, Yuan; Deng, Qifei; Dai, Xiayun; Lin, Dafeng; Huang, Suli; Guo, Huan; Lilly Zheng, S.; Xu, Jianfeng; Lin, Dongxin; Hu, Frank B.; Wu, Tangchun

2013-01-01

Plasma lipid levels are important risk factors for cardiovascular disease and are influenced by genetic and environmental factors. Recent genome wide association studies (GWAS) have identified several lipid-associated loci, but these loci have been identified primarily in European populations. In order to identify genetic markers for lipid levels in a Chinese population and analyze the heterogeneity between Europeans and Asians, especially Chinese, we performed a meta-analysis of two genome wide association studies on four common lipid traits including total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) in a Han Chinese population totaling 3,451 healthy subjects. Replication was performed in an additional 8,830 subjects of Han Chinese ethnicity. We replicated eight loci associated with lipid levels previously reported in a European population. The loci genome wide significantly associated with TC were near DOCK7, HMGCR and ABO; those genome wide significantly associated with TG were near APOA1/C3/A4/A5 and LPL; those genome wide significantly associated with LDL were near HMGCR, ABO and TOMM40; and those genome wide significantly associated with HDL were near LPL, LIPC and CETP. In addition, an additive genotype score of eight SNPs representing the eight loci that were found to be associated with lipid levels was associated with higher TC, TG and LDL levels (P = 5.52×10-16, 1.38×10-6 and 5.59×10-9, respectively). These findings suggest the cumulative effects of multiple genetic loci on plasma lipid levels. Comparisons with previous GWAS of lipids highlight heterogeneity in allele frequency and in effect size for some loci between Chinese and European populations. The results from our GWAS provided comprehensive and convincing evidence of the genetic determinants of plasma lipid levels in a Chinese population. PMID:24386095

The Tomato MIXTA-Like Transcription Factor Coordinates Fruit Epidermis Conical Cell Development and Cuticular Lipid Biosynthesis and Assembly1

PubMed Central

Lotan, Orfa; Alkan, Noam; Tsimbalist, Tatiana; Rechav, Katya; Fernandez-Moreno, Josefina-Patricia; Widemann, Emilie; Grausem, Bernard; Pinot, Franck; Costa, Fabrizio; Aharoni, Asaph

2015-01-01

The epidermis of aerial plant organs is the primary source of building blocks forming the outer surface cuticular layer. To examine the relationship between epidermal cell development and cuticle assembly in the context of fruit surface, we investigated the tomato (Solanum lycopersicum) MIXTA-like gene. MIXTA/MIXTA-like proteins, initially described in snapdragon (Antirrhinum majus) petals, are known regulators of epidermal cell differentiation. Fruit of transgenically silenced SlMIXTA-like tomato plants displayed defects in patterning of conical epidermal cells. They also showed altered postharvest water loss and resistance to pathogens. Transcriptome and cuticular lipids profiling coupled with comprehensive microscopy revealed significant modifications to cuticle assembly and suggested SlMIXTA-like to regulate cutin biosynthesis. Candidate genes likely acting downstream of SlMIXTA-like included cytochrome P450s (CYPs) of the CYP77A and CYP86A subfamilies, LONG-CHAIN ACYL-COA SYNTHETASE2, GLYCEROL-3-PHOSPHATE SN-2-ACYLTRANSFERASE4, and the ATP-BINDING CASSETTE11 cuticular lipids transporter. As part of a larger regulatory network of epidermal cell patterning and L1-layer identity, we found that SlMIXTA-like acts downstream of SlSHINE3 and possibly cooperates with homeodomain Leu zipper IV transcription factors. Hence, SlMIXTA-like is a positive regulator of both cuticle and conical epidermal cell formation in tomato fruit, acting as a mediator of the tight association between fruit cutin polymer formation, cuticle assembly, and epidermal cell patterning. PMID:26443676

Lipid Droplet-Associated Proteins (LDAPs) Are Required for the Dynamic Regulation of Neutral Lipid Compartmentation in Plant Cells1

PubMed Central

Park, Sunjung; Wu, Peng

2016-01-01

Eukaryotic cells compartmentalize neutral lipids into organelles called lipid droplets (LDs), and while much is known about the role of LDs in storing triacylglycerols in seeds, their biogenesis and function in nonseed tissues are poorly understood. Recently, we identified a class of plant-specific, lipid droplet-associated proteins (LDAPs) that are abundant components of LDs in nonseed cell types. Here, we characterized the three LDAPs in Arabidopsis (Arabidopsis thaliana) to gain insight to their targeting, assembly, and influence on LD function and dynamics. While all three LDAPs targeted specifically to the LD surface, truncation analysis of LDAP3 revealed that essentially the entire protein was required for LD localization. The association of LDAP3 with LDs was detergent sensitive, but the protein bound with similar affinity to synthetic liposomes of various phospholipid compositions, suggesting that other factors contributed to targeting specificity. Investigation of LD dynamics in leaves revealed that LD abundance was modulated during the diurnal cycle, and characterization of LDAP misexpression mutants indicated that all three LDAPs were important for this process. LD abundance was increased significantly during abiotic stress, and characterization of mutant lines revealed that LDAP1 and LDAP3 were required for the proper induction of LDs during heat and cold temperature stress, respectively. Furthermore, LDAP1 was required for proper neutral lipid compartmentalization and triacylglycerol degradation during postgerminative growth. Taken together, these studies reveal that LDAPs are required for the maintenance and regulation of LDs in plant cells and perform nonredundant functions in various physiological contexts, including stress response and postgerminative growth. PMID:26896396

Modification of the lipid moiety of the enterobacterial common antigen by the "Pseudomonas factor".

PubMed Central

Kuhn, H M; Neter, E; Mayer, H

1983-01-01

Pseudomonas aeruginosa produces a factor (PF) which affects the enterobacterial common antigen (ECA); resulting in failure of the antigen to modify erythrocytes for hemagglutination by ECA antibodies. In the present study the nature of PF was determined. Pronase treatment abolished its activity, indicating the protein nature of PF. PF-treated ECA no longer coated erythrocytes but still reacted with ECA antibodies in immunoelectrophoresis tests with monospecific antiserum to ECA, although differences were noted between the precipitation patterns of PF-treated and untreated ECA. Therefore, PF does not significantly affect the antigenic determinant of ECA but rather affects its lipid carrier, an L-glycerophosphatide. Accordingly, differences in the sugar chain could not be detected by high-voltage paper electrophoretic examinations of partial hydrolysates of PF-treated and untreated ECA. PF liberates all fatty acids from ECA, similarly to commercial lipases, as evidenced by the liberation of unsubstituted glycerol upon HF degradation at 0 degrees C of PF-treated ECA. The lipase activity of PF is indicated also by the observation that a strain of P. aeruginosa with reduced lipase production and an exolipase-negative strain affect ECA either less or not at all. We conclude that PF is a lipase acting on the lipid moiety of ECA, which is responsible for the coating of erythrocytes, but not significantly on the serological determinant, the amino sugar chain. Images PMID:6404831

Formulation of a novel oxybenzone-loaded nanostructured lipid carriers (NLCs).

PubMed

Sanad, Rania A; Abdelmalak, Nevine Shawky; Elbayoomy, Tahany S; Badawi, Alia A

2010-12-01

The objective of the current study was to formulate oxybenzone into nanostructured lipid carriers (NLCs) to enhance its sunscreening efficacy and safety. NLCs of oxybenzone were prepared by the solvent diffusion method. A complete 2(3) factorial design was used for the evaluation of the prepared oxybenzone NLCs. The study design involves the investigation of the effect of three independent variables namely liquid lipid type (Miglyol 812 and oleic acid), liquid lipid concentration (15% and 30%), and oxybenzone concentration (5% and 10% with respect to total lipids) on the particle size (p.s.) , the entrapment efficiency (EE%) and the in vitro drug release after 8 h. The prepared NLCs were spherical in overall shape and were below 0.8 microm. Miglyol 812 and 30% liquid lipid were found to significantly decrease the p.s. and increase the EE% when compared to oleic acid and 15% liquid lipid. Increasing oxybenzone concentration increased significantly the p.s. but did not affect the EE%. NLCs prepared using Miglyol 812, 15% liquid lipid, and 10% oxybenzone showed slower drug release when compared to those prepared using oleic acid, 30% liquid lipid, and 5% oxybenzone, respectively. The candidate oxybenzone-loaded NLC dispersion was then formulated into gel. The incorporation of oxybenzone into NLCs greatly increased the in vitro sun protection factor and erythemal UVA protection factor of oxybenzone more than six- and eightfold, respectively, while providing the advantage of overcoming side effects of free oxybenzone as evidenced by very low irritation potential.

Down-regulation of lipid raft-associated onco-proteins via cholesterol-dependent lipid raft internalization in docosahexaenoic acid-induced apoptosis.

PubMed

Lee, Eun Jeong; Yun, Un-Jung; Koo, Kyung Hee; Sung, Jee Young; Shim, Jaegal; Ye, Sang-Kyu; Hong, Kyeong-Man; Kim, Yong-Nyun

2014-01-01

Lipid rafts, plasma membrane microdomains, are important for cell survival signaling and cholesterol is a critical lipid component for lipid raft integrity and function. DHA is known to have poor affinity for cholesterol and it influences lipid rafts. Here, we investigated a mechanism underlying the anti-cancer effects of DHA using a human breast cancer cell line, MDA-MB-231. We found that DHA decreased cell surface levels of lipid rafts via their internalization, which was partially reversed by cholesterol addition. With DHA treatment, caveolin-1, a marker for rafts, and EGFR were colocalized with LAMP-1, a lysosomal marker, in a cholesterol-dependent manner, indicating that DHA induces raft fusion with lysosomes. DHA not only displaced several raft-associated onco-proteins, including EGFR, Hsp90, Akt, and Src, from the rafts but also decreased total levels of those proteins via multiple pathways, including the proteasomal and lysosomal pathways, thereby decreasing their activities. Hsp90 overexpression maintained its client proteins, EGFR and Akt, and attenuated DHA-induced cell death. In addition, overexpression of Akt or constitutively active Akt attenuated DHA-induced apoptosis. All these data indicate that the anti-proliferative effect of DHA is mediated by targeting of lipid rafts via decreasing cell surface lipid rafts by their internalization, thereby decreasing raft-associated onco-proteins via proteasomal and lysosomal pathways and decreasing Hsp90 chaperone function. © 2013.

Lipid Clustering Correlates with Membrane Curvature as Revealed by Molecular Simulations of Complex Lipid Bilayers

PubMed Central

Koldsø, Heidi; Shorthouse, David; Hélie, Jean; Sansom, Mark S. P.

2014-01-01

Cell membranes are complex multicomponent systems, which are highly heterogeneous in the lipid distribution and composition. To date, most molecular simulations have focussed on relatively simple lipid compositions, helping to inform our understanding of in vitro experimental studies. Here we describe on simulations of complex asymmetric plasma membrane model, which contains seven different lipids species including the glycolipid GM3 in the outer leaflet and the anionic lipid, phosphatidylinositol 4,5-bisphophate (PIP2), in the inner leaflet. Plasma membrane models consisting of 1500 lipids and resembling the in vivo composition were constructed and simulations were run for 5 µs. In these simulations the most striking feature was the formation of nano-clusters of GM3 within the outer leaflet. In simulations of protein interactions within a plasma membrane model, GM3, PIP2, and cholesterol all formed favorable interactions with the model α-helical protein. A larger scale simulation of a model plasma membrane containing 6000 lipid molecules revealed correlations between curvature of the bilayer surface and clustering of lipid molecules. In particular, the concave (when viewed from the extracellular side) regions of the bilayer surface were locally enriched in GM3. In summary, these simulations explore the nanoscale dynamics of model bilayers which mimic the in vivo lipid composition of mammalian plasma membranes, revealing emergent nanoscale membrane organization which may be coupled both to fluctuations in local membrane geometry and to interactions with proteins. PMID:25340788

Lipid clustering correlates with membrane curvature as revealed by molecular simulations of complex lipid bilayers.

PubMed

Koldsø, Heidi; Shorthouse, David; Hélie, Jean; Sansom, Mark S P

2014-10-01

Cell membranes are complex multicomponent systems, which are highly heterogeneous in the lipid distribution and composition. To date, most molecular simulations have focussed on relatively simple lipid compositions, helping to inform our understanding of in vitro experimental studies. Here we describe on simulations of complex asymmetric plasma membrane model, which contains seven different lipids species including the glycolipid GM3 in the outer leaflet and the anionic lipid, phosphatidylinositol 4,5-bisphophate (PIP2), in the inner leaflet. Plasma membrane models consisting of 1500 lipids and resembling the in vivo composition were constructed and simulations were run for 5 µs. In these simulations the most striking feature was the formation of nano-clusters of GM3 within the outer leaflet. In simulations of protein interactions within a plasma membrane model, GM3, PIP2, and cholesterol all formed favorable interactions with the model α-helical protein. A larger scale simulation of a model plasma membrane containing 6000 lipid molecules revealed correlations between curvature of the bilayer surface and clustering of lipid molecules. In particular, the concave (when viewed from the extracellular side) regions of the bilayer surface were locally enriched in GM3. In summary, these simulations explore the nanoscale dynamics of model bilayers which mimic the in vivo lipid composition of mammalian plasma membranes, revealing emergent nanoscale membrane organization which may be coupled both to fluctuations in local membrane geometry and to interactions with proteins.

Associations between long chain polyunsaturated fatty acids and cardiovascular lipid risk factors in youth with type 1 diabetes: SEARCH Nutrition Ancillary Study

PubMed Central

Couch, Sarah C.; Crandell, Jamie; King, Irena; Peairs, Abigail; Shah, Amy S; Dolan, Lawrence M; Tooze, Janet; Crume, Tessa; Mayer-Davis, Elizabeth

2017-01-01

Purpose In this longitudinal study we explored the relationships between plasma n-3 and n-6 polyunsaturated fatty acids (PUFAs) and Δ5 and Δ6 desaturase activities (D5D and D6D, respectively) and fasting lipids in youth with type 1 diabetes (T1D). Methods Incident cases of T1D in youth <20 years of age who were seen for a baseline study visit (N=914) and a 1-year follow-up visit (N=416) were included. Fasting blood samples were obtained at each visit and plasma phospholipid n-6 PUFAs were measured, which included linoleic acid (LA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA); n-3 PUFAs included α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Estimated D5D and D6D were calculated as FA product-to-precursor ratios, where D5D= AA/DGLA and D6D = DGLA/LA. To examine the longitudinal relationships between long chain PUFAs, desaturase activities and fasting plasma lipids in youth with T1D mixed effects models were used for each individual PUFAs, D5D and D6D, adjusted for demographics, clinic site, diabetes duration, insulin regimen, insulin dose/kg, HbA1c, insulin sensitivity score, and body mass index with random effects to account for the repeated measurements. Findings Favorable lipid associations were found between LA and low-density lipoprotein (LDL) cholesterol (β= −0.58, P<0.05); AA, plasma triglycerides (TG) (β= −0.04, P<0.05) and TG/ high-density lipoprotein (HDL)-C ratio (β= −0.04, P<0.05); and D5D, plasma TG (β= −0.2, P<0.05) and TG/HDL-cholesterol ratio (β= −0.23, P<0.05). Findings were mixed for the n-3 PUFAs and DGLA: ALA was positively associated with plasma TG (β= 0.33, P<0.05) and HDL cholesterol (β= 9.86, P<0.05); EPA was positively associated with total cholesterol (β= 8.17, P<0.05), LDL cholesterol (β=5.74, P<0.01) and HDL cholesterol (β= 2.27, P<0.01); and DGLA was positively associated with TG/HDL-cholesterol ratio (β= 0.05, P<0.05) Conclusion Findings suggest that the most

Preservation of Microbial Lipids in Geothermal Sinters

NASA Astrophysics Data System (ADS)

Kaur, Gurpreet; Mountain, Bruce W.; Hopmans, Ellen C.; Pancost, Richard D.

2011-04-01

Lipid biomarkers are widely used to study the earliest life on Earth and have been invoked as potential astrobiological markers, but few studies have assessed their survival and persistence in geothermal settings. Here, we investigate lipid preservation in active and inactive geothermal silica sinters, with ages of up to 900 years, from Champagne Pool, Waiotapu, New Zealand. Analyses revealed a wide range of bacterial biomarkers, including free and bound fatty acids, 1,2-di-O-alkylglycerols (diethers), and various hopanoids. Dominant archaeal lipids include archaeol and glycerol dialkyl glycerol tetraethers (GDGTs). The predominance of generally similar biomarker groups in all sinters suggests a stable microbial community throughout Champagne Pool's history and indicates that incorporated lipids can be well preserved. Moreover, subtle differences in lipid distributions suggest that past changes in environmental conditions can be elucidated. In this case, higher archaeol abundances relative to the bacterial diethers, a greater proportion of cyclic GDGTs, the high average chain length of the bacterial diethers, and greater concentrations of hopanoic acids in the older sinters all suggest hotter conditions at Champagne Pool in the past.

The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation.

PubMed

Sharma, Hari; Zhang, Xiaoying; Dwivedi, Chandradhar

2010-04-01

Ghee, also known as clarified butter, has been utilized for thousands of years in Ayurveda as a therapeutic agent. In ancient India, ghee was the preferred cooking oil. In the last several decades, ghee has been implicated in the increased prevalence of coronary artery disease (CAD) in Asian Indians due to its content of saturated fatty acids and cholesterol and, in heated ghee, cholesterol oxidation products. Our previous research on Sprague-Dawley outbred rats, which serve as a model for the general population, showed no effect of 5 and 10% ghee-supplemented diets on serum cholesterol and triglycerides. However, in Fischer inbred rats, which serve as a model for genetic predisposition to diseases, results of our previous research showed an increase in serum total cholesterol and triglyceride levels when fed a 10% ghee-supplemented diet. In the present study, we investigated the effect of 10% dietary ghee on microsomal lipid peroxidation, as well as serum lipid levels in Fischer inbred rats to assess the effect of ghee on free radical mediated processes that are implicated in many chronic diseases including cardiovascular disease. Results showed that 10% dietary ghee fed for 4 weeks did not have any significant effect on levels of serum total cholesterol, but did increase triglyceride levels in Fischer inbred rats. Ghee at a level of 10% in the diet did not increase liver microsomal lipid peroxidation or liver microsomal lipid peroxide levels. Animal studies have demonstrated many beneficial effects of ghee, including dose-dependent decreases in serum total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate. Similar results were seen with heated (oxidized) ghee which contains cholesterol oxidation products. A preliminary clinical study showed that high doses of

Lipid Quality in Infant Nutrition: Current Knowledge and Future Opportunities

PubMed Central

Delplanque, Bernadette; Gibson, Robert; Koletzko, Berthold; Lapillonne, Alexandre; Strandvik, Birgitta

2015-01-01

Abstract Dietary lipids are key for infants to not only meet their high energy needs but also fulfill numerous metabolic and physiological functions critical to their growth, development, and health. The lipid composition of breast milk varies during lactation and according to the mother's diet, whereas the lipid composition of infant formulae varies according to the blend of different fat sources. This report compares the compositions of lipids in breast milk and infant formulae, and highlights the roles of dietary lipids in term and preterm infants and their potential biological and health effects. The major differences between breast milk and formulae lie in a variety of saturated fatty acids (such as palmitic acid, including its structural position) and unsaturated fatty acids (including arachidonic acid and docosahexaenoic acid), cholesterol, and complex lipids. The functional outcomes of these differences during infancy and for later child and adult life are still largely unknown, and some of them are discussed, but there is consensus that opportunities exist for improvements in the qualitative lipid supply to infants through the mother's diet or infant formulae. Furthermore, research is required in several areas, including the needs of term and preterm infants for long-chain polyunsaturated fatty acids, the sites of action and clinical effects of lipid mediators on immunity and inflammation, the role of lipids on metabolic, neurological, and immunological outcomes, and the mechanisms by which lipids act on short- and long-term health. PMID:25883056

Structure, stability, and thermodynamics of lamellar DNA-lipid complexes.

PubMed Central

Harries, D; May, S; Gelbart, W M; Ben-Shaul, A

1998-01-01

We develop a statistical thermodynamic model for the phase evolution of DNA-cationic lipid complexes in aqueous solution, as a function of the ratios of charged to neutral lipid and charged lipid to DNA. The complexes consist of parallel strands of DNA intercalated in the water layers of lamellar stacks of mixed lipid bilayers, as determined by recent synchrotron x-ray measurements. Elastic deformations of the DNA and the lipid bilayers are neglected, but DNA-induced spatial inhomogeneities in the bilayer charge densities are included. The relevant nonlinear Poisson-Boltzmann equation is solved numerically, including self-consistent treatment of the boundary conditions at the polarized membrane surfaces. For a wide range of lipid compositions, the phase evolution is characterized by three regions of lipid to DNA charge ratio, rho: 1) for low rho, the complexes coexist with excess DNA, and the DNA-DNA spacing in the complex, d, is constant; 2) for intermediate rho, including the isoelectric point rho = 1, all of the lipid and DNA in solution is incorporated into the complex, whose inter-DNA distance d increases linearly with rho; and 3) for high rho, the complexes coexist with excess liposomes (whose lipid composition is different from that in the complex), and their spacing d is nearly, but not completely, independent of rho. These results can be understood in terms of a simple charging model that reflects the competition between counterion entropy and inter-DNA (rho < 1) and interbilayer (rho > 1) repulsions. Finally, our approach and conclusions are compared with theoretical work by others, and with relevant experiments. PMID:9649376

Nanostructured lipid carriers to enhance transdermal delivery and efficacy of diclofenac.

PubMed

Nguyen, Chien Ngoc; Nguyen, Thi Thuy Trang; Nguyen, Hanh Thuy; Tran, Tuan Hiep

2017-10-01

Lipid carrier-mediated transdermal drug delivery offers several advantages because it is non-irritating and non-toxic, provides effective control of drug release, and forms an adhesive film that hydrates the outer skin layers. However, to penetrate the deeper skin layers, these formulations need to overcome several barriers in the stratum corneum. This study evaluates factors influencing particle size and drug-loading capacity, which play a key role in drug permeation and efficacy. Diclofenac sodium was chosen as the model drug. The fabrication of diclofenac sodium-loaded lipid nanoparticles was optimized by modulating several parameters, including the lipids and surfactants employed, the drug/lipid ratio, and the pH of the aqueous phase. The physical properties and loading efficiencies of the nanoparticles were characterized. The optimized formulation was then dispersed into a polymer solution to form a gel, which demonstrated a sustained ex vivo permeation of diclofenac sodium over 24 h through excised rat skin and a higher drug penetrating capacity than that of a commercially available gel. In vivo anti-inflammatory activity was assessed in a rat carrageenan-induced paw edema model; the anti-edema effects of the prepared gel and commercially available gel over 24 h were comparable. The present findings indicate the effects of particle size and drug loading on the ability of nanostructured lipid carrier preparations to provide transdermal drug delivery.

A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

PubMed Central

2014-01-01

Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

Effect of liquid-to-solid lipid ratio on characterizations of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) for transdermal administration.

PubMed

Song, Aihua; Zhang, Xiaoshu; Li, Yanting; Mao, Xinjuan; Han, Fei

2016-08-01

The aim of this study is to evaluate the effect of liquid-to-solid lipid ratio on properties of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), and to clarify the superiority of NLCs over SLNs for transdermal administration. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, differential scanning calorimetry, X-ray diffractometry, in vitro percutaneous permeation profile, and stability of SLNs and NLCs were compared. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, and in vitro percutaneous permeation amount of the developed NLCs were all <200 nm, < -20 mV, >78%, >35, and >240 μg/cm(2), respectively, however, for SLNs were 280 nm, -29.11 mV, 63.2%, 32.54, and 225.9 μg/cm(2), respectively. After 3 months storage at 4 °C and 25 °C, almost no significant differences between the evaluated parameters of NLCs were observed. However, for SLNs, particle size was increased to higher than 300 nm (4 °C and 25 °C), drug encapsulation efficiency was decreased to 51.2 (25 °C), in vitro occlusion factor was also decreased to lower than 25 (4 °C and 25 °C), and the cumulative amount was decreased to 148.9 μg/cm(2) (25 °C) and 184.4 μg/cm(2) (4 °C), respectively. And DSC and XRD studies indicated that not only the crystalline peaks of the encapsulated flurbiprofen disappeared but also obvious difference between samples and bulk Compritol® ATO 888 was seen. It could be concluded that liquid-to-solid lipid ratio has significant impact on the properties of SLNs and NLCs, and NLCs showed better stability than SLNs. Therefore, NLCs might be a better option than SLNs for transdermal administration.

Nuclear Receptors, Mitochondria, and Lipid Metabolism

PubMed Central

Alaynick, William A.

2009-01-01

Lipid metabolism is a continuum from emulsification and uptake of lipids in the intestine to cellular uptake and transport to compartments such as mitochondria. Whether fats are shuttled into lipid droplets in adipose tissue or oxidized in mitochondria and peroxisomes depends on metabolic substrate availability, energy balance and endocrine signaling of the organism. Several members of the nuclear hormone receptor superfamily are lipid-sensing factors that affect all aspects of lipid metabolism. The physiologic actions of glandular hormones (e.g. thyroid, mineralocorticoid and glucocorticoid), vitamins (e.g. vitamins A and D) and reproductive hormones (e.g. progesterone, estrogen and testosterone) and their cognate receptors are well established. The peroxisome proliferator activated receptors (PPARs) and Liver X receptors (LXRs), acting in concert with PPARγ Coactivator 1α (PGC-1α), have been shown to regulate insulin sensitivity and lipid handling. These receptors are the focus of intense pharmacologic studies to expand the armamentarium of small molecule ligands to treat diabetes and the metabolic syndrome (hypertension, insulin resistance, hyperglycemia, dyslipidemia, and obesity). Recently, additional partners of PGC-1α have moved to the forefront of metabolic research, the Estrogen-related Receptors (ERRs). Although no endogenous ligands for these receptors have been identified, phenotypic analyses of knockout mouse models demonstrate an important role for these molecules in substrate sensing and handling as well as mitochondrial function. PMID:18375192

Near infrared Raman spectra of human brain lipids

NASA Astrophysics Data System (ADS)

Krafft, Christoph; Neudert, Lars; Simat, Thomas; Salzer, Reiner

2005-05-01

Human brain tissue, in particular white matter, contains high lipid content. These brain lipids can be divided into three principal classes: neutral lipids including the steroid cholesterol, phospholipids and sphingolipids. Major lipids in normal human brain tissue are phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, phosphatidic acid, sphingomyelin, galactocerebrosides, gangliosides, sulfatides and cholesterol. Minor lipids are cholesterolester and triacylglycerides. During transformation from normal brain tissue to tumors, composition and concentration of lipids change in a specific way. Therefore, analysis of lipids might be used as a diagnostic parameter to distinguish normal tissue from tumors and to determine the tumor type and tumor grade. Raman spectroscopy has been suggested as an analytical tool to detect these changes even under intra-operative conditions. We recorded Raman spectra of the 12 major and minor brain lipids with 785 nm excitation in order to identify their spectral fingerprints for qualitative and quantitative analyses.

Discovery of Novel Lipid Profiles in PCOS: Do Insulin and Androgen Oppositely Regulate Bioactive Lipid Production?

PubMed

Li, Shengxian; Chu, Qianqian; Ma, Jing; Sun, Yun; Tao, Tao; Huang, Rong; Liao, Yu; Yue, Jiang; Zheng, Jun; Wang, Lihua; Xue, Xinli; Zhu, Mingjiang; Kang, Xiaonan; Yin, Huiyong; Liu, Wei

2017-03-01

Polycystic ovary syndrome (PCOS) is a complex syndrome showing clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Polyunsaturated fatty acids (PUFAs) and their derivatives, both tightly linked to PCOS and obesity, play important roles in inflammation and reproduction. This study aimed to investigate serum lipid profiles in newly diagnosed patients with PCOS using lipidomics and correlate these features with the hyperinsulinemia and hyperandrogenism associated with PCOS and obesity. Thirty-two newly diagnosed women with PCOS and 34 controls were divided into obese and lean subgroups. A PCOS rat model was used to validate results of the human studies. Serum lipid profiles, including phospholipids, free fatty acids (FFAs), and bioactive lipids, were analyzed using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS. Elevation in phosphatidylcholine and a concomitant decrease in lysophospholipid were found in obese patients with PCOS vs lean controls. Obese patients with PCOS had decreased PUFA levels and increased levels of long-chain saturated fatty acids vs lean controls. Serum bioactive lipids downstream of arachidonic acid were increased in obese controls, but reduced in both obese and lean patients with PCOS vs their respective controls. Patients with PCOS showed abnormal levels of phosphatidylcholine, FFAs, and PUFA metabolites. Circulating insulin and androgens may have opposing effects on lipid profiles in patients with PCOS, particularly on the bioactive lipid metabolites derived from PUFAs. These clinical observations warrant further studies of the molecular mechanisms and clinical implications of PCOS and obesity. Copyright © 2017 by the Endocrine Society

Discovery of Novel Lipid Profiles in PCOS: Do Insulin and Androgen Oppositely Regulate Bioactive Lipid Production?

PubMed Central

Li, Shengxian; Chu, Qianqian; Ma, Jing; Sun, Yun; Tao, Tao; Huang, Rong; Liao, Yu; Yue, Jiang; Zheng, Jun; Wang, Lihua; Xue, Xinli; Zhu, Mingjiang; Kang, Xiaonan; Yin, Huiyong

2017-01-01

Abstract Context: Polycystic ovary syndrome (PCOS) is a complex syndrome showing clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Polyunsaturated fatty acids (PUFAs) and their derivatives, both tightly linked to PCOS and obesity, play important roles in inflammation and reproduction. Objective: This study aimed to investigate serum lipid profiles in newly diagnosed patients with PCOS using lipidomics and correlate these features with the hyperinsulinemia and hyperandrogenism associated with PCOS and obesity. Design and Setting: Thirty-two newly diagnosed women with PCOS and 34 controls were divided into obese and lean subgroups. A PCOS rat model was used to validate results of the human studies. Main Outcome Measures: Serum lipid profiles, including phospholipids, free fatty acids (FFAs), and bioactive lipids, were analyzed using gas chromatography–mass spectrometry (MS) and liquid chromatography–MS. Results: Elevation in phosphatidylcholine and a concomitant decrease in lysophospholipid were found in obese patients with PCOS vs lean controls. Obese patients with PCOS had decreased PUFA levels and increased levels of long-chain saturated fatty acids vs lean controls. Serum bioactive lipids downstream of arachidonic acid were increased in obese controls, but reduced in both obese and lean patients with PCOS vs their respective controls. Conclusions: Patients with PCOS showed abnormal levels of phosphatidylcholine, FFAs, and PUFA metabolites. Circulating insulin and androgens may have opposing effects on lipid profiles in patients with PCOS, particularly on the bioactive lipid metabolites derived from PUFAs. These clinical observations warrant further studies of the molecular mechanisms and clinical implications of PCOS and obesity. PMID:27886515

Lipidomic and proteomic analysis of Caenorhabditis elegans lipid droplets and identification of ACS-4 as a lipid droplet-associated protein

DOE PAGES

Vrablik, Tracy L.; Petyuk, Vladislav A.; Larson, Emily M.; ...

2015-06-27

Lipid droplets are cytoplasmic organelles that store neutral lipids for membrane synthesis and energy reserves. In this study, we characterized the lipid and protein composition of purified Caenorhabditis elegans lipid droplets. These lipid droplets are composed mainly of triacylglycerols, surrounded by a phospholipid monolayer composed primarily of phosphatidylcholine and phosphatidylethanolamine. The fatty acid composition of the triacylglycerols is rich in fatty acid species obtained from the dietary Escherichia coli, including cyclopropane fatty acids and cis-vaccenic acid. Unlike other organisms, C. elegans lipid droplets contain very little cholesterol or cholesterol esters. Comparison of the lipid droplet proteomes of wild type andmore » high-fat daf-2 mutant strains shows a very similar proteome in both strains, except that the most abundant protein in the C. elegans lipid droplet proteome, MDT-28, is relatively less abundant in lipid droplets isolated from daf-2 mutants. Functional analysis of lipid droplet proteins identified in our proteomic studies indicated an enrichment of proteins required for growth and fat homeostasis in C. elegans. Finally, we confirmed the localization of one of the newly identified lipid droplet proteins, ACS-4. We found that ACS-4 localizes to the surface of lipid droplets in the C. elegans intestine and skin. This study bolsters C. elegans as a model to study the dynamics and functions of lipid droplets in a multicellular organism.« less

Lipid effects on neutrophil calcium signaling induced by opsonized particles: platelet activating factor is only part of the story.

PubMed

Wanten, Geert; Kusters, Anneke; van Emst-de Vries, Sjenet E; Tool, Anton; Roos, Dirk; Naber, Ton; Willems, Peter

2004-08-01

Total parenteral nutrition is frequently used in clinical practice to improve the nutritional status of patients. However, the risk for infectious complications remains a drawback in which immune-modulating effects of the lipid component may play a role. To characterize these lipid effects we investigated neutrophil activation by opsonized yeast particles under influence of lipid emulsions derived from fish oil (VLCT), olive oil (LCT-MUFA), soybean oil (LCT), and a physical mixture of coconut and soybean oil (LCT-MCT). Serum-treated zymosan (STZ) evoked a biphasic increase in cytosolic Ca2+ concentration ([Ca2+]c) with an initial slow rise that turned into a second fast rise until a plateau was reached. LCT-MCT (5 mM) pretreatment markedly increased the rate of [Ca2+]c rise during the initial phase, abolished the second phase and lowered the plateau. These effects of LCT-MCT were mimicked by the protein kinase C (PKC) activating phorbol ester PMA. LCT, LCT-MUFA and VLCT, on the other hand, decreased the rate of [Ca2+]c rise during both phases and lowered the plateau. The platelet-activating factor (PAF) receptor antagonist WEB 2086 inhibited the second phase, demonstrating that PAF acts as an intercellular messenger in STZ-induced Ca2+ mobilization, but did not interfere with the stimulatory effect of LCT-MCT or PMA on the initial rate of [Ca2+]c rise. Structurally different lipids act only in part through PAF to distinctively modulate neutrophil calcium signaling in response to activation by opsonized particles. Copyright 2003 Elsevier Ltd.

An independent effect of parental lipids on the offspring lipid levels in a cohort of adolescents with type 1 diabetes.

PubMed

Marcovecchio, M Loredana; Tossavainen, Paivi H; Heywood, James Jn; Dalton, R Neil; Dunger, David B

2012-09-01

Genetic factors modulate lipid levels and an intrafamilial aggregation of abnormal lipid profiles has been reported in the general population. As dyslipidemia is common among people with diabetes and has been related to diabetic nephropathy, we investigated whether parental lipid levels were related to lipids and albumin excretion in young offspring with childhood-onset type 1 diabetes (T1D). Non-fasting blood samples were collected from 895 offspring, 808 mothers and 582 fathers. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and non-HDL-C were measured. Three early morning urinary albumin-creatinine ratios (ACR), hemoglobin A1C (HbA1c) and anthropometric parameters were also assessed. The offspring's mean age (±SD) was 14.5 ± 2.2 yr, mean diabetes duration 5.5 ± 3.7 yr; the fathers' age was 45.7 ± 6.1 yr and the mothers' age was 42.8 ± 5.5 yr. After adjusting for the offspring age, gender, body mass index, HbA1c, maternal (TC: β = 0.242; TG: β = 0.152; HDL-C: β = 0.285; LDL-C: β = 0.278; non-HDL-C: β = 0.253; all p < 0.001) and paternal lipid levels (TC: β = 0.188; TG: β = 0.108; HDL-C: β = 0.253; LDL-C: β = 0.187; non-HDL-C: β = 0.173; all p < 0.001) were significantly associated with the offspring's lipid parameters. In contrast, no significant association was found between parental lipid levels and the offspring's ACR. In the present study, parental lipid levels were independently associated with the same traits in the offspring, suggesting a role of genetic influences and/or shared environmental factors in modulating the metabolic profile of adolescents with T1D. In contrast, there was no significant association between parental lipid levels and the offspring's albumin excretion. © 2012 John Wiley & Sons A/S.

An improved high-throughput lipid extraction method for the analysis of human brain lipids.

PubMed

Abbott, Sarah K; Jenner, Andrew M; Mitchell, Todd W; Brown, Simon H J; Halliday, Glenda M; Garner, Brett

2013-03-01

We have developed a protocol suitable for high-throughput lipidomic analysis of human brain samples. The traditional Folch extraction (using chloroform and glass-glass homogenization) was compared to a high-throughput method combining methyl-tert-butyl ether (MTBE) extraction with mechanical homogenization utilizing ceramic beads. This high-throughput method significantly reduced sample handling time and increased efficiency compared to glass-glass homogenizing. Furthermore, replacing chloroform with MTBE is safer (less carcinogenic/toxic), with lipids dissolving in the upper phase, allowing for easier pipetting and the potential for automation (i.e., robotics). Both methods were applied to the analysis of human occipital cortex. Lipid species (including ceramides, sphingomyelins, choline glycerophospholipids, ethanolamine glycerophospholipids and phosphatidylserines) were analyzed via electrospray ionization mass spectrometry and sterol species were analyzed using gas chromatography mass spectrometry. No differences in lipid species composition were evident when the lipid extraction protocols were compared, indicating that MTBE extraction with mechanical bead homogenization provides an improved method for the lipidomic profiling of human brain tissue.

LIPID ABNORMALITIES AND LIPID-BASED REPAIR STRATEGIES IN ATOPIC DERMATITIS

PubMed Central

Elias, Peter M.

2013-01-01

Prior studies have revealed the key roles played by Th1/Th2 cell dysregulation, IgE production, mast cell hyperactivity, and dendritic cell signaling in the evolution of the chronic, pruritic, inflammatory dermatosis that characterizes atopic dermatitis (AD). We review here increasing evidence that the inflammation in AD results primarily from inherited abnormalities in epidermal structural and enzymatic proteins that impact permeability barrier function. We also will show that the barrier defect can be attributed to a paracellular abnormality due to a variety of abnormalities in lipid composition, transport and extracellular organization. Accordingly, we also review the therapeutic implications of this emerging pathogenic paradigm, including several current and potentially novel, lipid-based approaches to corrective therapy. PMID:24128970

Impact of plant-based diet on lipid risk factors for atherosclerosis.

PubMed

Kuchta, Agnieszka; Lebiedzińska, Anna; Fijałkowski, Marcin; Gałąska, Rafał; Kreft, Ewelina; Totoń, Magdalena; Czaja, Kuba; Kozłowska, Anna; Ćwiklińska, Agnieszka; Kortas-Stempak, Barbara; Strzelecki, Adrian; Gliwińska, Anna; Dąbkowski, Kamil; Jankowski, Maciej

2016-01-01

The aim of the study was to investigate the effect of a vegan diet on the serum lipid profile with particular regard to the parameters characterizing the high-density lipoprotein (HDL) fractions in subjects without subclinical atherosclerosis, measured by carotid Doppler ultrasonography. Forty-two 23 to 38 year old subjects (21 omnivores and 21 vegans) participated in the study. Compared to the omnivores, the vegan subjects were characterized by lower parameters of lipid profile: total cholesterol (p < 0.001), low-density lipoprotein (LDL)-cholesterol (p < 0.001), non-HDL-cholesterol (p < 0.001), apolipoprotein B (apoB) (p < 0.001) and phospholipids (p < 0.01). Concentration of HDL-cholesterol was apparently similar between groups. Furthermore, the parameters which characterize HDL particles (con-centration of apolipoproteins AI [apoAI] and AII, HDL-phospholipids, LpAI fraction and pre-b1-HDL fraction) were not significantly different between omnivore and vegan subjects. The apoB/apoAI ratio in vegans was lower than in omnivores (p < 0.01). There was no difference between serum concentration of triacylglycerols between omnivores and vegans. The activity of paraoxonase-1 and 8-iso-prostaglandin F2a concentration were also not different between the study groups. We suggest that a vegan diet may have a beneficial effect on serum lipid profile and cardiovascular protection, but it is not associated with changes in HDL composition.

What are the effects of psychological stress and physical work on blood lipid profiles?

PubMed Central

Assadi, Seyedeh Negar

2017-01-01

Abstract Blood lipids disorders are prevalent in the world. Some of their risk factors are modifiable such as mental and physical stress which existed in some places such as work environment. Objective of this study was to determine the effects of psychological and physical stress on the lipid profiles. It was a historical cohort study. The people who were employed as general worker were participated. The study was conducted with flexible interview for getting history, lipid profile examination, and a checklist including occupational and nonoccupational risk factors and using the health issues. According to the type of stress exposures, the study population was divided into 5 groups. Groups were followed for lipid profiles. These groups were exposed to psychological stress, physical stress or both of them; mild psychological stress (group 1), mild physical work without psychological stress (group 2), mild psychological stress and mild physical work (group 3), moderate physical work without psychological stress (group 4), and heavy physical work without psychological stress (group 5). Data were analyzed with SPSS 16. ANOVA, χ2, and exact test were calculated with considering P < .05 as significant level. Relative risks were calculated with confidence interval 95%. The means of lipid profiles were in normal ranges. The relative risks for triglycerides more than 200 mg/dL was 1.57 (1.02–2.42) and low density lipoprotein (LDL) more than 130 mg/dL was 14.54 (3.54–59.65) in group 1. The relative risks for high density lipoprotein (HDL) less than 45 mg/dL was 14.61 (8.31–25.68) in group 1 and 16.00 (8.30–30.83) in group 3. After multinomial logistic regression they had significant differences. Psychological stress was a risk factor for lipid disorders, and suitable physical activity was protective in this situation. PMID:28471984

Metabolism. Part III: Lipids.

ERIC Educational Resources Information Center

Bodner, George M.

1986-01-01

Describes the metabolic processes of complex lipids, including saponification, activation and transport, and the beta-oxidation spiral. Discusses fatty acid degradation in regard to biochemical energy and ketone bodies. (TW)

microRNAs and lipid metabolism

PubMed Central

Aryal, Binod; Singh, Abhishek K.; Rotllan, Noemi; Price, Nathan; Fernández-Hernando, Carlos

2017-01-01

Purpose of review Work over the last decade has identified the important role of microRNAs (miRNAS) in regulating lipoprotein metabolism and associated disorders including metabolic syndrome, obesity and atherosclerosis. This review summarizes the most recent findings in the field, highlighting the contribution of miRNAs in controlling low-density lipoprotein (LDL) and high-density lipoprotein (HDL) metabolism. Recent findings A number of miRNAs have emerged as important regulators of lipid metabolism, including miR-122 and miR-33. Work over the last two years has identified additional functions of miR-33 including the regulation of macrophage activation and mitochondrial metabolism. Moreover, it has recently been shown that miR-33 regulates vascular homeostasis and cardiac adaptation in response to pressure overload. In addition to miR-33 and miR-122, recent GWAS have identified single nucleotide polymorphisms (SNP) in the proximity of miRNAs genes associated with abnormal levels of circulating lipids in humans. Several of these miRNA, such as miR-148a and miR-128-1, target important proteins that regulate cellular cholesterol metabolism, including the low-density lipoprotein receptor (LDLR) and the ATP-binding cassette A1 (ABCA1). Summary microRNAs have emerged as critical regulators of cholesterol metabolism and promising therapeutic targets for treating cardiometabolic disorders including atherosclerosis. Here, we discuss the recent findings in the field highlighting the novel mechanisms by which miR-33 controls lipid metabolism and atherogenesis and the identification of novel miRNAs that regulate LDL metabolism. Finally, we summarize the recent findings that identified miR-33 as an important non-coding RNA that controls cardiovascular homeostasis independent of its role in regulating lipid metabolism. PMID:28333713

Implications of lipid raft disintegration: enhanced anti-inflammatory macrophage phenotype.

PubMed

Cuschieri, Joseph

2004-08-01

Lipid rafts are membrane microdomains characterized by an enriched cholesterol environment and appear to serve as a platform for signaling. Their role within the macrophage during endotoxin exposure is unknown. THP-1 cells were subjected to lipopolysaccharide stimulation with or without methyl-beta-cyclodextrin (MbetaCD) pretreatment, a cholesterol depleting agent. Cell surface expression of toll-like receptor-4 (TLR4) and platelet-activating factor receptor (PAFr) was determined by flow cytometry. Membrane receptor components and activation of the mitogen-activated protein kinases (MAPK) was determined from lipid raft and cellular protein by immunoblot. Inflammatory mediator production was determined from harvested supernatants by enzyme-linked immunosorbent assay. Surface expression of TLR4 and PAFr was not affected by MbetaCD. Lipopolysaccharide stimulation led to TLR4 mobilization to lipid rafts, MAPK activation, and inflammatory mediator production. Pretreatment with MbetaCD did not affect TLR4 mobilization to lipid rafts, but did result in lost lipid raft expression of the PAFr coupled G-protein, Galpha1. MbetaCD treatment led to selective attenuation of MAPK activation through ERK 1/2. This dysregulated signaling was associated with attenuated production of tumor necrosis factor-alpha, but increased production of interleukin-10. Lipid raft disintegration results in lost expression of Galpha1, dysregulated MAPK signaling, and selective anti-inflammatory mediator production. Therefore, modulation of lipid raft cholesterol content may represent a potential mechanism for regulation of macrophage phenotypic differentiation. Copyright 2004 Elsevier Inc.

Analysis of Lipids and Lipid Rafts in Borrelia.

PubMed

Toledo, Alvaro; Huang, Zhen; Benach, Jorge L; London, Erwin

2018-01-01

Lipid rafts are membrane microdomains that are involved in cellular processes such as protein trafficking and signaling processes, and which play a fundamental role in membrane fluidity and budding. The lipid composition of the membrane and the biochemical characteristics of the lipids found within rafts define the ability of cells to form microdomains and compartmentalize the membrane. In this chapter, we describe the biophysical, biochemical, and molecular approaches used to define and characterize lipid rafts in the Lyme disease agent, Borrelia burgdorferi.

The multifaceted interplay between lipids and epigenetics.

PubMed

Dekkers, Koen F; Slagboom, P Eline; Jukema, J Wouter; Heijmans, Bastiaan T

2016-06-01

The interplay between lipids and epigenetic mechanisms has recently gained increased interest because of its relevance for common diseases and most notably atherosclerosis. This review discusses recent advances in unravelling this interplay with a particular focus on promising approaches and methods that will be able to establish causal relationships. Complementary approaches uncovered close links between circulating lipids and epigenetic mechanisms at multiple levels. A characterization of lipid-associated genetic variants suggests that these variants exert their influence on lipid levels through epigenetic changes in the liver. Moreover, exposure of monocytes to lipids persistently alters their epigenetic makeup resulting in more proinflammatory cells. Hence, epigenetic changes can both impact on and be induced by lipids. It is the combined application of technological advances to probe epigenetic modifications at a genome-wide scale and methodological advances aimed at causal inference (including Mendelian randomization and integrative genomics) that will elucidate the interplay between circulating lipids and epigenetics. Understanding its role in the development of atherosclerosis holds the promise of identifying a new category of therapeutic targets, since epigenetic changes are amenable to reversal.

Phloem proteomics reveals new lipid-binding proteins with a putative role in lipid-mediated signaling

DOE PAGES

Barbaglia, Allison M.; Tamot, Banita; Greve, Veronica; ...

2016-04-28

Global climate changes inversely affect our ability to grow the food required for an increasing world population. To combat future crop loss due to abiotic stress, we need to understand the signals responsible for changes in plant development and the resulting adaptations, especially the signaling molecules traveling long-distance through the plant phloem. Using a proteomics approach, we had identified several putative lipid-binding proteins in the phloem exudates. Simultaneously, we identified several complex lipids as well as jasmonates. These findings prompted us to propose that phloem (phospho-) lipids could act as long-distance developmental signals in response to abiotic stress, and thatmore » they are released, sensed, and moved by phloem lipid-binding proteins (Benning et al., 2012). Indeed, the proteins we identified include lipases that could release a signaling lipid into the phloem, putative receptor components, and proteins that could mediate lipid-movement. To test this possible protein-based lipid-signaling pathway, three of the proteins, which could potentially act in a relay, are characterized here: (I) a putative GDSL-motif lipase (II) a PIG-P-like protein, with a possible receptor-like function; (III) and PLAFP (phloem lipid-associated family protein), a predicted lipid-binding protein of unknown function. Here we show that all three proteins bind lipids, in particular phosphatidic acid (PtdOH), which is known to participate in intracellular stress signaling. Genes encoding these proteins are expressed in the vasculature, a prerequisite for phloem transport. Cellular localization studies show that the proteins are not retained in the endoplasmic reticulum but surround the cell in a spotted pattern that has been previously observed with receptors and plasmodesmatal proteins. Abiotic signals that induce the production of PtdOH also regulate the expression of GDSL-lipase and PLAFP, albeit in opposite patterns. Our findings suggest that while all

Phloem proteomics reveals new lipid-binding proteins with a putative role in lipid-mediated signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbaglia, Allison M.; Tamot, Banita; Greve, Veronica

Global climate changes inversely affect our ability to grow the food required for an increasing world population. To combat future crop loss due to abiotic stress, we need to understand the signals responsible for changes in plant development and the resulting adaptations, especially the signaling molecules traveling long-distance through the plant phloem. Using a proteomics approach, we had identified several putative lipid-binding proteins in the phloem exudates. Simultaneously, we identified several complex lipids as well as jasmonates. These findings prompted us to propose that phloem (phospho-) lipids could act as long-distance developmental signals in response to abiotic stress, and thatmore » they are released, sensed, and moved by phloem lipid-binding proteins (Benning et al., 2012). Indeed, the proteins we identified include lipases that could release a signaling lipid into the phloem, putative receptor components, and proteins that could mediate lipid-movement. To test this possible protein-based lipid-signaling pathway, three of the proteins, which could potentially act in a relay, are characterized here: (I) a putative GDSL-motif lipase (II) a PIG-P-like protein, with a possible receptor-like function; (III) and PLAFP (phloem lipid-associated family protein), a predicted lipid-binding protein of unknown function. Here we show that all three proteins bind lipids, in particular phosphatidic acid (PtdOH), which is known to participate in intracellular stress signaling. Genes encoding these proteins are expressed in the vasculature, a prerequisite for phloem transport. Cellular localization studies show that the proteins are not retained in the endoplasmic reticulum but surround the cell in a spotted pattern that has been previously observed with receptors and plasmodesmatal proteins. Abiotic signals that induce the production of PtdOH also regulate the expression of GDSL-lipase and PLAFP, albeit in opposite patterns. Our findings suggest that while all

Effect of an individualised physical exercise program on lipid profile in sedentary patients with cardiovascular risk factors.

PubMed

Rubio Pérez, Francisco Javier; Franco Bonafonte, Luis; Ibarretxe Guerediaga, Daiana; Oyon Belaza, Maria Pilar; Ugarte Peyron, Paola

Physical exercise has become in an important tool in the reduction of cardiovascular risk. To evaluate the effectiveness of an unsupervised physical exercise program that on the physical condition and the lipid profile. The final sample included 49 sedentary men and women, who were non-smokers, with dyslipidaemia, overweight, and type1 obesity. The 4-month program included walking for 30-60minutes every day, and for three days a week, 30minutes of cycling at an intensity of 40-60% of maximum functional capacity, as well as isometric abdominals and static stretching. Anthropometrics, physical condition (6minute test), and the lipid profile were evaluated before and after the physical exercise program. The objective was to achieve a caloric expenditure between 1200-2000kcal/week. At the end of the program it was observed, in both sexes, that there was a decrease in total cholesterol (P<0.02), LDL cholesterol (P<0.01), VLDL cholesterol (P<0.01), and triglycerides (P<0.05), and an increase HDL cholesterol (P<0.05). There was also an increase in the distance travelled in the 6minute test of 52m in men and 39.5m in women (P<0.002), plus a decrease in the perception of fatigue on the Borg scale of 1.19 in men, and 0.96 in women (P<0.01). There were no anthropometric changes. The physical exercise improved physical condition and the lipid profile in the sample that has been studied, with 64% of participants continuing to do it. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Lipid nanocarriers: influence of lipids on product development and pharmacokinetics.

PubMed

Pathak, Kamla; Keshri, Lav; Shah, Mayank

2011-01-01

Lipid nanocarriers are on the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery. Owing to their size-dependent properties, lipid nanoparticles offer the possibility for development of new therapeutics and an alternative system to other colloidal counterparts for drug administration. An important point to be considered in the selection of a lipid for the carrier system is its effect on the properties of the nanocarrier and also its intended use, as different types of lipids differ in their nature. Researchers around the globe have tapped the potential of solid lipid nanoparticles (SLNs) in developing formulation(s) that can be administered by various routes such as oral, ocular, parenteral, topical, and pulmonary. Since the start of this millennium, a new generation of lipid nanoparticles, namely nanostructured lipid carriers (NLCs), lipid drug conjugates (LDCs), and pharmacosomes, has evolved that have the potential to overcome the limitations of SLNs. The current review article presents broad considerations on the influence of various types of lipids on the diverse characteristics of nanocarriers, encompassing their physicochemical, formulation, pharmacokinetic, and cytotoxic aspects.

Comparative effects of cholesteryl ester transfer protein inhibition, statin or ezetimibe on lipid factors: The ACCENTUATE trial.

PubMed

Nicholls, Stephen J; Ray, Kausik K; Ballantyne, Christie M; Beacham, Lauren A; Miller, Debra L; Ruotolo, Giacomo; Nissen, Steven E; Riesmeyer, Jeffrey S

2017-06-01

The optimal approaches to management of patients treated with moderate statin doses on lipid parameters are unknown. The ACCENTUATE study aimed to compare the effects of adding the cholesteryl ester transfer protein inhibitor (CETP) evacetrapib, ezetimibe or increasing statin dose in atorvastatin-treated high-vascular risk patients on lipid parameters. 366 patients with atherosclerotic cardiovascular disease (ASCVD) and/or diabetes were treated with atorvastatin 40 mg/day for 28 days prior to randomization to atorvastatin 40 mg plus evacetrapib 130 mg, atorvastatin 80 mg, atorvastatin 40 mg plus ezetimibe 10 mg or atorvastatin 40 mg plus placebo, daily for 90 days at 64 centers in the United States. Lipid parameters, safety and tolerability were measured. Addition of evacetrapib significantly reduced LDL-C (-33%) compared with ezetimibe (-27%, p=0.045), increasing statin dose (-6%) and statin alone (0%, p<0.001). Evacetrapib also decreased apoB by 23% compared to 19% with ezetimibe (p=0.06) and 7% with increased statin dose (p<0.001), and reduced Lp(a) by 29% (p<0.001 vs. other groups). Evacetrapib increased HDL-C (+125%), apoA-I (+46%), apoC-III (+50%) and apoE (+28%) (p<0.001 vs. other groups). Non-ABCA1-mediated efflux increased by 53% (p<0.001 vs. other groups) with evacetrapib. ABCA1-mediated efflux also increased by 13% with evacetrapib (p<0.001 vs. ezetimibe, p=0.002 vs. increasing statin dose, and p=0.004 vs. statin alone). Addition of evacetrapib to atorvastatin produced an increase in hsCRP compared with ezetimibe (p=0.02). While evacetrapib improved traditional atherogenic and putative protective lipid measures compared with ezetimibe and increasing statin dose in patients with ASCVD and/or diabetes, it also adversely affected novel atherogenic risk factors. These findings may contribute to the lack of clinical benefit observed in the ACCELERATE trial. Copyright © 2017 Elsevier B.V. All rights reserved.

LIPID11: A Modular Framework for Lipid Simulations using Amber

PubMed Central

Skjevik, Åge A.; Madej, Benjamin D.; Walker, Ross C.; eigen, Knut T

2013-01-01

Accurate simulation of complex lipid bilayers has long been a goal in condensed phase molecular dynamics (MD). Structure and function of membrane-bound proteins are highly dependent on the lipid bilayer environment and are challenging to study through experimental methods. Within Amber, there has been limited focus on lipid simulations, although some success has been seen with the use of the General Amber Force Field (GAFF). However, to date there are no dedicated Amber lipid force fields. In this paper we describe a new charge derivation strategy for lipids consistent with the Amber RESP approach, and a new atom and residue naming and type convention. In the first instance, we have combined this approach with GAFF parameters. The result is LIPID11, a flexible, modular framework for the simulation of lipids that is fully compatible with the existing Amber force fields. The charge derivation procedure, capping strategy and nomenclature for LIPID11, along with preliminary simulation results and a discussion of the planned long-term parameter development are presented here. Our findings suggest that Lipid11 is a modular framework feasible for phospholipids and a flexible starting point for the development of a comprehensive, Amber-compatible lipid force field. PMID:22916730

Wrinkled1 Accelerates Flowering and Regulates Lipid Homeostasis between Oil Accumulation and Membrane Lipid Anabolism in Brassica napus.

PubMed

Li, Qing; Shao, Jianhua; Tang, Shaohua; Shen, Qingwen; Wang, Tiehu; Chen, Wenling; Hong, Yueyun

2015-01-01

Wrinkled1 (WRI1) belongs to the APETALA2 transcription factor family; it is unique to plants and is a central regulator of oil synthesis in Arabidopsis. The effects of WRI1 on comprehensive lipid metabolism and plant development were unknown, especially in crop plants. This study found that BnWRI1 in Brassica napus accelerated flowering and enhanced oil accumulation in both seeds and leaves without leading to a visible growth inhibition. BnWRI1 decreased storage carbohydrates and increased soluble sugars to facilitate the carbon flux to lipid anabolism. BnWRI1 is localized to the nucleus and directly binds to the AW-box at proximal upstream regions of genes involved in fatty acid (FA) synthesis and lipid assembly. The overexpression (OE) of BnWRI1 resulted in the up-regulation of genes involved in glycolysis, FA synthesis, lipid assembly, and flowering. Lipid profiling revealed increased galactolipids monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and phosphatidylcholine (PC) in the leaves of OE plants, whereas it exhibited a reduced level of the galactolipids DGDG and MGDG and increased levels of PC, phosphatidylethanolamide, and oil [triacylglycerol (TAG)] in the siliques of OE plants during the early seed development stage. These results suggest that BnWRI1 is important for homeostasis among TAG, membrane lipids and sugars, and thus facilitates flowering and oil accumulation in B. napus.

Risk Factors for Breast Cancer, Including Occupational Exposures

PubMed Central

Meo, Margrethe; Vainio, Harri

2011-01-01

The knowledge on the etiology of breast cancer has advanced substantially in recent years, and several etiological factors are now firmly established. However, very few new discoveries have been made in relation to occupational risk factors. The International Agency for Research on Cancer has evaluated over 900 different exposures or agents to-date to determine whether they are carcinogenic to humans. These evaluations are published as a series of Monographs (www.iarc.fr). For breast cancer the following substances have been classified as "carcinogenic to humans" (Group 1): alcoholic beverages, exposure to diethylstilbestrol, estrogen-progestogen contraceptives, estrogen-progestogen hormone replacement therapy and exposure to X-radiation and gamma-radiation (in special populations such as atomic bomb survivors, medical patients, and in-utero exposure). Ethylene oxide is also classified as a Group 1 carcinogen, although the evidence for carcinogenicity in epidemiologic studies, and specifically for the human breast, is limited. The classification "probably carcinogenic to humans" (Group 2A) includes estrogen hormone replacement therapy, tobacco smoking, and shift work involving circadian disruption, including work as a flight attendant. If the association between shift work and breast cancer, the most common female cancer, is confirmed, shift work could become the leading cause of occupational cancer in women. PMID:22953181

Relation of Plasma Lipids to Alzheimer Disease and Vascular Dementia

PubMed Central

Reitz, Christiane; Tang, Ming-Xin; Luchsinger, Jose; Mayeux, Richard

2009-01-01

Background The relation between plasma lipid levels and Alzheimer disease (AD) and vascular dementia (VaD), and the impact of drugs to lower lipid levels remains unclear. Objective To investigate the relation between plasma lipid levels and the risk of AD and VaD and the impact of drugs to lower lipid levels on this relationship. Design and Setting Cross-sectional and prospective community-based cohort studies. Participants Random sample of 4316 Medicare recipients, 65 years and older, residing in northern Manhattan, NY. Main Outcome Measures Vascular dementia and AD according to standard criteria. Results Elevated levels of non–high-density lipoprotein (HDL-C) and low-density lipoprotein cholesterol (LDL-C) and decreased levels of HDL-C were weak risk factors for VaD in either cross-sectional or prospective analyses. Higher levels of total cholesterol were associated with a decreased risk of incident AD after adjustment for demographics, apolipoprotein E genotype, and cardiovascular risk factors. Treatment with drugs to lower lipid levels did not change the disease risk of either disorder. Conclusions We found a weak relation between non–HDL-C, LDL-C, and HDL-C levels and the risk of VaD. Lipid levels and the use of agents to lower them do not seem to be associated with the risk of AD. PMID:15148148

Lipid Profiles in Wheat Cultivars Resistant and Susceptible to Tan Spot and the Effect of Disease on the Profiles

PubMed Central

Kim, Dongwon; Jeannotte, Richard; Welti, Ruth; Bockus, William W.

2013-01-01

Lipid profiles in wheat leaves and the effects of tan spot on the profiles were quantified by mass spectrometry. Inoculation with Pyrenophora tritici-repentis significantly reduced the amount of leaf lipids, including the major plastidic lipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), which together accounted for 89% of the mass spectral signal of detected lipids in wheat leaves. Levels of these lipids in susceptible cultivars dropped much more quickly during infection than those in resistant cultivars. Furthermore, cultivars resistant or susceptible to tan spot displayed different lipid profiles; leaves of resistant cultivars had more MGDG and DGDG than susceptible ones, even in non-inoculated plants. Lipid compositional data from leaves of 20 non-inoculated winter wheat cultivars were regressed against an index of disease susceptibility and fitted with a linear model. This analysis demonstrated a significant relationship between resistance and levels of plastidic galactolipids and indicated that cultivars with high resistance to tan spot uniformly had more MGDG and DGDG than cultivars with high susceptibility. These findings suggest that lipid composition of wheat leaves may be a determining factor in the resistance response of cultivars to tan spot. PMID:23035632

Lipidomics reveals a remarkable diversity of lipids in human plasma.

PubMed

Quehenberger, Oswald; Armando, Aaron M; Brown, Alex H; Milne, Stephen B; Myers, David S; Merrill, Alfred H; Bandyopadhyay, Sibali; Jones, Kristin N; Kelly, Samuel; Shaner, Rebecca L; Sullards, Cameron M; Wang, Elaine; Murphy, Robert C; Barkley, Robert M; Leiker, Thomas J; Raetz, Christian R H; Guan, Ziqiang; Laird, Gregory M; Six, David A; Russell, David W; McDonald, Jeffrey G; Subramaniam, Shankar; Fahy, Eoin; Dennis, Edward A

2010-11-01

The focus of the present study was to define the human plasma lipidome and to establish novel analytical methodologies to quantify the large spectrum of plasma lipids. Partial lipid analysis is now a regular part of every patient's blood test and physicians readily and regularly prescribe drugs that alter the levels of major plasma lipids such as cholesterol and triglycerides. Plasma contains many thousands of distinct lipid molecular species that fall into six main categories including fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, and prenols. The physiological contributions of these diverse lipids and how their levels change in response to therapy remain largely unknown. As a first step toward answering these questions, we provide herein an in-depth lipidomics analysis of a pooled human plasma obtained from healthy individuals after overnight fasting and with a gender balance and an ethnic distribution that is representative of the US population. In total, we quantitatively assessed the levels of over 500 distinct molecular species distributed among the main lipid categories. As more information is obtained regarding the roles of individual lipids in health and disease, it seems likely that future blood tests will include an ever increasing number of these lipid molecules.

Biologic Activity of Porphyromonas endodontalis complex lipids

PubMed Central

Mirucki, Christopher S.; Abedi, Mehran; Jiang, Jin; Zhu, Qiang; Wang, Yu-Hsiung; Safavi, Kamran E.; Clark, Robert B.; Nichols, Frank C.

2014-01-01

Introduction Periapical infections secondary to pulpal necrosis are associated with bacterial contamination of the pulp. Porphyromonas endodontalis, a Gram-negative organism, is considered to be a pulpal pathogen. P. gingivalis is phylogenetically related to P. endodontalis and synthesizes several classes of novel complex lipids that possess biological activity, including the capacity to promote osteoclastogenesis and osteoclast activation. The purpose of this study was to extract and characterize constituent lipids of P. endodontalis, and evaluate their capacity to promote pro-inflammatory secretory responses in the macrophage cell line, RAW 264.7, as well as their capacity to promote osteoclastogenesis and inhibit osteoblast activity. Methods Constituent lipids of both organisms were fractionated by HPLC and were structurally characterized using electrospray-mass spectrometry (ESI-MS) or ESI-MS/MS. The virulence potential of P. endodontalis lipids was then compared with known biologically active lipids isolated from P. gingivalis. Results P. endodontalis total lipids were shown to promote TNF-α secretion from RAW 264.7 cells and the serine lipid fraction appeared to account for the majority of this effect. P. endodontalis lipid preparations also increased osteoclast formation from RAW 264.7 cells but osteoblast differentiation in culture was inhibited and appeared to be dependent on TLR2 expression. Conclusions These effects underscore the importance of P. endodontalis lipids in promoting inflammatory and bone cell activation processes that could lead to periapical pathology. PMID:25146013

No association of apolipoprotein B gene polymorphism and blood lipids in obese Egyptian subjects.

PubMed

Bogari, Neda M; Abdel-Latif, Azza M; Hassan, Maha A; Ramadan, Abeer; Fawzy, Ahmed

2015-03-18

Several environmental and genetic factors are associated with high levels of lipids in obese patients. Apolipoprotein B (ApoB) is the major protein component of low-density lipoproteins (LDL), very-low density lipoproteins (VLDL) and chylomicrons and plays a central role in lipid metabolism. Several apoB restriction fragment length polymorphisms (XbaI, EcoRI, MspI) have been reported to be associated with variation in lipid levels and obesity. To date, no data are available on the relationship between XbaI polymorphism and lipid levels in Egyptian populations. Following clinical profiling, 178 obese (body mass index [BMI] >25 kg/m(2)) and 178 age-matched non-obese (BMI ≤ 25 kg/m(2)) subjects were included in this case-control study. All samples were analysed for total cholesterol, triglycerides and HDL-cholesterol. Genetic analysis of apoB XbaI (X) was performed using Polymerase Chain Reaction-Restriction Fragment Length polymorphism (PCR-RFLP). The aim of this study was to assess the association of apoB XbaI gene polymorphism (X) and lipid profiles in obese and non-obese Egyptian populations. Obese subjects demonstrated significantly higher values of waist-to-hip ratio, blood pressure, and total lipid. However, in our sample we did not find significant differences in apoB XbaI gene polymorphism (X) genotype or allele frequencies. Moreover, none of the studied lipid parameters showed any association with the gene polymorphism. This study reveals no significant association of apoB XbaI gene polymorphism (X) with obesity or lipid profiles in an Egyptian population.

Emerging Roles for the Lysosome in Lipid Metabolism.

PubMed

Thelen, Ashley M; Zoncu, Roberto

2017-11-01

Precise regulation of lipid biosynthesis, transport, and storage is key to the homeostasis of cells and organisms. Cells rely on a sophisticated but poorly understood network of vesicular and nonvesicular transport mechanisms to ensure efficient delivery of lipids to target organelles. The lysosome stands at the crossroads of this network due to its ability to process and sort exogenous and endogenous lipids. The lipid-sorting function of the lysosome is intimately connected to its recently discovered role as a metabolic command-and-control center, which relays multiple nutrient cues to the master growth regulator, mechanistic target of rapamycin complex (mTORC)1 kinase. In turn, mTORC1 potently drives anabolic processes, including de novo lipid synthesis, while inhibiting lipid catabolism. Here, we describe the dual role of the lysosome in lipid transport and biogenesis, and we discuss how integration of these two processes may play important roles both in normal physiology and in disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lipids, lipid genes, and incident age-related macular degeneration: the three continent age-related macular degeneration consortium.

PubMed

Klein, Ronald; Myers, Chelsea E; Buitendijk, Gabriëlle H S; Rochtchina, Elena; Gao, Xiaoyi; de Jong, Paulus T V M; Sivakumaran, Theru A; Burlutsky, George; McKean-Cowdin, Roberta; Hofman, Albert; Iyengar, Sudha K; Lee, Kristine E; Stricker, Bruno H; Vingerling, Johannes R; Mitchell, Paul; Klein, Barbara E K; Klaver, Caroline C W; Wang, Jie Jin

2014-09-01

To describe associations of serum lipid levels and lipid pathway genes to the incidence of age-related macular degeneration (AMD). Meta-analysis. setting: Three population-based cohorts. population: A total of 6950 participants from the Beaver Dam Eye Study (BDES), Blue Mountains Eye Study (BMES), and Rotterdam Study (RS). observation procedures: Participants were followed over 20 years and examined at 5-year intervals. Hazard ratios associated with lipid levels per standard deviation above the mean or associated with each additional risk allele for each lipid pathway gene were calculated using random-effects inverse-weighted meta-analysis models, adjusting for known AMD risk factors. main outcome measures: Incidence of AMD. The average 5-year incidences of early AMD were 8.1%, 15.1%, and 13.0% in the BDES, BMES, and RS, respectively. Substantial heterogeneity in the effect of cholesterol and lipid pathway genes on the incidence and progression of AMD was evident when the data from the 3 studies were combined in meta-analysis. After correction for multiple comparisons, we did not find a statistically significant association between any of the cholesterol measures, statin use, or serum lipid genes and any of the AMD outcomes in the meta-analysis. In a meta-analysis, there were no associations of cholesterol measures, history of statin use, or lipid pathway genes to the incidence and progression of AMD. These findings add to inconsistencies in earlier reports from our studies and others showing weak associations, no associations, or inverse associations of high-density lipoprotein cholesterol and total cholesterol with AMD. Copyright © 2014 Elsevier Inc. All rights reserved.

Oral mucosal lipids are antibacterial against Porphyromonas gingivalis, induce ultrastructural damage, and alter bacterial lipid and protein compositions.

PubMed

Fischer, Carol L; Walters, Katherine S; Drake, David R; Dawson, Deborah V; Blanchette, Derek R; Brogden, Kim A; Wertz, Philip W

2013-09-01

Oral mucosal and salivary lipids exhibit potent antimicrobial activity for a variety of Gram-positive and Gram-negative bacteria; however, little is known about their spectrum of antimicrobial activity or mechanisms of action against oral bacteria. In this study, we examine the activity of two fatty acids and three sphingoid bases against Porphyromonas gingivalis, an important colonizer of the oral cavity implicated in periodontitis. Minimal inhibitory concentrations, minimal bactericidal concentrations, and kill kinetics revealed variable, but potent, activity of oral mucosal and salivary lipids against P. gingivalis, indicating that lipid structure may be an important determinant in lipid mechanisms of activity against bacteria, although specific components of bacterial membranes are also likely important. Electron micrographs showed ultrastructural damage induced by sapienic acid and phytosphingosine and confirmed disruption of the bacterial plasma membrane. This information, coupled with the association of treatment lipids with P. gingivalis lipids revealed via thin layer chromatography, suggests that the plasma membrane is a likely target of lipid antibacterial activity. Utilizing a combination of two-dimensional in-gel electrophoresis and Western blot followed by mass spectroscopy and N-terminus degradation sequencing we also show that treatment with sapienic acid induces upregulation of a set of proteins comprising a unique P. gingivalis stress response, including proteins important in fatty acid biosynthesis, metabolism and energy production, protein processing, cell adhesion and virulence. Prophylactic or therapeutic lipid treatments may be beneficial for intervention of infection by supplementing the natural immune function of endogenous lipids on mucosal surfaces.

Lipid nanoparticles based on butyl-methoxydibenzoylmethane: in vitro UVA blocking effect

NASA Astrophysics Data System (ADS)

Niculae, G.; Lacatusu, I.; Badea, N.; Meghea, A.

2012-08-01

The aim of the present study was to obtain efficient lipid nanoparticles loaded with butyl-methoxydibenzoylmethane (BMDBM) in order to develop cosmetic formulations with enhanced UVA blocking effect. For this purpose, two adequate liquid lipids (medium chain triglycerides and squalene) have been used in combination with two solid lipids (cetyl palmitate and glyceryl stearate) in order to create appropriate nanostructured carriers with a disordered lipid network able to accommodate up to 1.5% BMDBM. The lipid nanoparticles (LNs) were characterized in terms of particle size, zeta potential, entrapment efficiency, loading capacity and in vitro UVA blocking effect. The efficiency of lipid nanoparticles in developing some cosmetic formulations has been evaluated by determining the in vitro erythemal UVA protection factor. In order to quantify the photoprotective effect, some selected cream formulations based on BMDBM-LNs and a conventional emulsion were exposed to photochemical UV irradiation at a low energy to simulate the solar energy during the midday. The results obtained demonstrated the high ability of cream formulations based on BMDBM-LNs to absorb more than 96% of UVA radiation. Moreover, the developed cosmetic formulations manifest an enhanced UVA blocking effect, the erythemal UVA protection factor being four times higher than those specific to conventional emulsions.

HIV replication enhances production of free fatty acids, low density lipoproteins and many key proteins involved in lipid metabolism: a proteomics study.

PubMed

Rasheed, Suraiya; Yan, Jasper S; Lau, Alex; Chan, Arvan S

2008-08-20

HIV-infected patients develop multiple metabolic abnormalities including insulin resistance, lipodystrophy and dyslipidemia. Although progression of these disorders has been associated with the use of various protease inhibitors and other antiretroviral drugs, HIV-infected individuals who have not received these treatments also develop lipid abnormalities albeit to a lesser extent. How HIV alters lipid metabolism in an infected cell and what molecular changes are affected through protein interaction pathways are not well-understood. Since many genetic, epigenetic, dietary and other factors influence lipid metabolism in vivo, we have chosen to study genome-wide changes in the proteomes of a human T-cell line before and after HIV infection in order to circumvent computational problems associated with multiple variables. Four separate experiments were conducted including one that compared 14 different time points over a period of >3 months. By subtractive analyses of protein profiles overtime, several hundred differentially expressed proteins were identified in HIV-infected cells by mass spectrometry and each protein was scrutinized for its biological functions by using various bioinformatics programs. Herein, we report 18 HIV-modulated proteins and their interaction pathways that enhance fatty acid synthesis, increase low density lipoproteins (triglycerides), dysregulate lipid transport, oxidize lipids, and alter cellular lipid metabolism. We conclude that HIV replication alone (i.e. without any influence of antiviral drugs, or other human genetic factors), can induce novel cellular enzymes and proteins that are significantly associated with biologically relevant processes involved in lipid synthesis, transport and metabolism (p = <0.0002-0.01). Translational and clinical studies on the newly discovered proteins may now shed light on how some of these proteins may be useful for early diagnosis of individuals who might be at high risk for developing lipid

Autophagic Regulation of Lipid Homeostasis in Cardiometabolic Syndrome.

PubMed

Yang, Mingjie; Zhang, Yingmei; Ren, Jun

2018-01-01

As an important protein quality control process, autophagy is essential for the degradation and removal of long-lived or injured cellular components and organelles. Autophagy is known to participate in a number of pathophysiological processes including cardiometabolic syndrome. Recent findings have shown compelling evidence for the intricate interplay between autophagy and lipid metabolism. Autophagy serves as a major regulator of lipid homeostasis while lipid can also influence autophagosome formation and autophagic signaling. Lipophagy is a unique form of selective autophagy and functions as a fundamental mechanism for clearance of lipid excess in atherosclerotic plaques. Ample of evidence has denoted a novel therapeutic potential for autophagy in deranged lipid metabolism and management of cardiometabolic diseases such as atherosclerosis and diabetic cardiomyopathy. Here we will review the interplays between cardiac autophagy and lipid metabolism in an effort to seek new therapeutic options for cardiometabolic diseases.

Chemical and structural investigation of lipid nanoparticles: drug-lipid interaction and molecular distribution

NASA Astrophysics Data System (ADS)

Anantachaisilp, Suranan; Meejoo Smith, Siwaporn; Treetong, Alongkot; Pratontep, Sirapat; Puttipipatkhachorn, Satit; Rungsardthong Ruktanonchai, Uracha

2010-03-01

Lipid nanoparticles are a promising alternative to existing carriers in chemical or drug delivery systems. A key challenge is to determine how chemicals are incorporated and distributed inside nanoparticles, which assists in controlling chemical retention and release characteristics. This study reports the chemical and structural investigation of γ-oryzanol loading inside a model lipid nanoparticle drug delivery system composed of cetyl palmitate as solid lipid and Miglyol 812® as liquid lipid. The lipid nanoparticles were prepared by high pressure homogenization at varying liquid lipid content, in comparison with the γ-oryzanol free systems. The size of the lipid nanoparticles, as measured by the photon correlation spectroscopy, was found to decrease with increased liquid lipid content from 200 to 160 nm. High-resolution proton nuclear magnetic resonance (1H-NMR) measurements of the medium chain triglyceride of the liquid lipid has confirmed successful incorporation of the liquid lipid in the lipid nanoparticles. Differential scanning calorimetric and powder x-ray diffraction measurements provide complementary results to the 1H-NMR, whereby the crystallinity of the lipid nanoparticles diminishes with an increase in the liquid lipid content. For the distribution of γ-oryzanol inside the lipid nanoparticles, the 1H-NMR revealed that the chemical shifts of the liquid lipid in γ-oryzanol loaded systems were found at rather higher field than those in γ-oryzanol free systems, suggesting incorporation of γ-oryzanol in the liquid lipid. In addition, the phase-separated structure was observed by atomic force microscopy for lipid nanoparticles with 0% liquid lipid, but not for lipid nanoparticles with 5 and 10% liquid lipid. Raman spectroscopic and mapping measurements further revealed preferential incorporation of γ-oryzanol in the liquid part rather than the solid part of in the lipid nanoparticles. Simple models representing the distribution of γ-oryzanol and

[Overweight, obesity and lipids abnormalities in adolescents with type 1 diabetes].

PubMed

Wysocka-Mincewicz, Marta; Kołodziejczyk, Honorata; Wierzbicka, Elżbieta; Szalecki, Mieczysław

2016-02-18

Overweight children are growing problem as in the pediatric, as well in the diabetic population. The aim of the study was to research the percentage of overweight and obesity in a group of adolescents with type 1 diabetes, and to analyzethe lipid parameters, as well risk factors of these abnormalities. The study group consist of 60 type 1 diabetic adolescents (including 32 girls, 53.3%), aged above 12 years (mean age for girls 14.6+/-0,3years, boys 15.6+/-0.4 years) with diabetes duration (girls 5.7+-0.6 years, boys 4.4+/-0.8 years). Statistical analysis was performed using Statistica v 9.0 and SPSS v20. The study revealed that boys with type 1 diabetes are significantly higher than healthy population, with weight, waist circumference and BMI comparable to the healthy counterparts. However, diabetic girls are more likely to be overweight and have bigger waist circumference, and higher BMI than the healthy population. Overweight were 12 adolescents (20%) using BMI ≥1SD criterion, and 10 (16%) using waist circumference as obesity parameter. Logistic regression revealed that the most important factors for obesity and abdominal obesity are female gender (OR=2.43 and OR=4.56for obesity and abdominal, respectively), diabetes duration above 5 years (respectively OR=1.96 and OR=3.27) and poor metabolic control (respectively OR=1.74 and OR=2.89). The most important risk factor for obesity in adolescents with type 1 diabetes is female gender. Lipids profile is closely dependent on metabolic control and mass excess. Diabetes duration, metabolic control and lipids profile are significant risk factors for overweight and abdominal obesity. © Polish Society for Pediatric Endocrinology and Diabetology.

Lipid nanotechnologies for structural studies of membrane-associated proteins.

PubMed

Stoilova-McPhie, Svetla; Grushin, Kirill; Dalm, Daniela; Miller, Jaimy

2014-11-01

We present a methodology of lipid nanotubes (LNT) and nanodisks technologies optimized in our laboratory for structural studies of membrane-associated proteins at close to physiological conditions. The application of these lipid nanotechnologies for structure determination by cryo-electron microscopy (cryo-EM) is fundamental for understanding and modulating their function. The LNTs in our studies are single bilayer galactosylceramide based nanotubes of ∼20 nm inner diameter and a few microns in length, that self-assemble in aqueous solutions. The lipid nanodisks (NDs) are self-assembled discoid lipid bilayers of ∼10 nm diameter, which are stabilized in aqueous solutions by a belt of amphipathic helical scaffold proteins. By combining LNT and ND technologies, we can examine structurally how the membrane curvature and lipid composition modulates the function of the membrane-associated proteins. As proof of principle, we have engineered these lipid nanotechnologies to mimic the activated platelet's phosphtaidylserine rich membrane and have successfully assembled functional membrane-bound coagulation factor VIII in vitro for structure determination by cryo-EM. The macromolecular organization of the proteins bound to ND and LNT are further defined by fitting the known atomic structures within the calculated three-dimensional maps. The combination of LNT and ND technologies offers a means to control the design and assembly of a wide range of functional membrane-associated proteins and complexes for structural studies by cryo-EM. The presented results confirm the suitability of the developed methodology for studying the functional structure of membrane-associated proteins, such as the coagulation factors, at a close to physiological environment. © 2014 Wiley Periodicals, Inc.

Racial differences in levels of serum lipids and effects of exposure to persistent organic pollutants on lipid levels in residents of Anniston, Alabama.

PubMed

Aminov, Zafar; Haase, Richard; Olson, James R; Pavuk, Marian; Carpenter, David O

2014-12-01

Serum lipid levels are major risk factors for cardiovascular disease. In addition to diet, exercise, genetics, age and race, serum concentrations of persistent organic pollutants (POPs) influence concentrations of serum lipids. We investigated associations between fasting concentrations of 35 polychlorinated biphenyl (PCB) congeners and nine organochlorine pesticides in relation to total serum lipids, total cholesterol, low-density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides in 525 Caucasian and African American residents of Anniston, Alabama, who were not on any lipid-lowering medication. In Model 1, data were adjusted for age, age quadratic, gender, BMI, alcohol consumption, smoking and exercise, while in Model 2, additional adjustment was done for other POPs. As compared to Caucasians, African Americans had lower levels of total lipids and triglycerides with higher concentrations of HDL cholesterol, but higher concentrations of PCBs and pesticides. Total pesticides were more strongly associated with elevations in serum lipids than were total PCBs, and the associations were stronger in African Americans. Total DDTs were not associated with serum lipids after adjustment for other POPs in either racial group, while the strongest positive associations were seen for hexachlorobenzene (HCB) in both racial groups. Racial differences in lipid profiles, concentrations of POPs and associations between POP concentrations and serum lipids are relevant to racial differences in rates of cardiovascular disease. Copyright © 2014 Elsevier Ltd. All rights reserved.

Wheat leaf lipids during heat stress: II. Lipids experiencing coordinated metabolism are detected by analysis of lipid co-occurrence

PubMed Central

Narayanan, Sruthi; Prasad, P.V. Vara; Welti, Ruth

2016-01-01

Identifying lipids that experience coordinated metabolism during heat stress would provide information regarding lipid dynamics under stress conditions and assist in developing heat-tolerant wheat varieties. We hypothesized that co-occurring lipids, which are up-or-down-regulated together through time during heat stress, represent groups that can be explained by coordinated metabolism. Wheat plants (Triticum aestivum L.) were subjected to 12 days of high day and/or night temperature stress, followed by a 4-day recovery period. Leaves were sampled at four time points, and 165 lipids were measured by electrospray ionization-tandem mass spectrometry. Correlation analysis of lipid levels in 160 leaf samples from each of two wheat genotypes revealed 13 groups of lipids. Lipids within each group co-occurred through the high day and night temperature stress treatments. The lipid groups can be broadly classified as groups containing: extraplastidic phospholipids, plastidic glycerolipids, oxidized glycerolipids, triacylglycerols, acylated sterol glycosides, and sterol glycosides. Current knowledge of lipid metabolism suggests that the lipids in each group co-occur because they are regulated by the same enzyme(s). The results suggest that increases in activities of desaturating, oxidizing, glycosylating, and acylating enzymes lead to simultaneous changes in levels of multiple lipid species during high day and night temperature stress in wheat. PMID:26436445

Mechanisms of stable lipid loss in a social insect

PubMed Central

Ament, Seth A.; Chan, Queenie W.; Wheeler, Marsha M.; Nixon, Scott E.; Johnson, S. Peir; Rodriguez-Zas, Sandra L.; Foster, Leonard J.; Robinson, Gene E.

2011-01-01

SUMMARY Worker honey bees undergo a socially regulated, highly stable lipid loss as part of their behavioral maturation. We used large-scale transcriptomic and proteomic experiments, physiological experiments and RNA interference to explore the mechanistic basis for this lipid loss. Lipid loss was associated with thousands of gene expression changes in abdominal fat bodies. Many of these genes were also regulated in young bees by nutrition during an initial period of lipid gain. Surprisingly, in older bees, which is when maximum lipid loss occurs, diet played less of a role in regulating fat body gene expression for components of evolutionarily conserved nutrition-related endocrine systems involving insulin and juvenile hormone signaling. By contrast, fat body gene expression in older bees was regulated more strongly by evolutionarily novel regulatory factors, queen mandibular pheromone (a honey bee-specific social signal) and vitellogenin (a conserved yolk protein that has evolved novel, maturation-related functions in the bee), independent of nutrition. These results demonstrate that conserved molecular pathways can be manipulated to achieve stable lipid loss through evolutionarily novel regulatory processes. PMID:22031746

Mechanisms of stable lipid loss in a social insect.

PubMed

Ament, Seth A; Chan, Queenie W; Wheeler, Marsha M; Nixon, Scott E; Johnson, S Peir; Rodriguez-Zas, Sandra L; Foster, Leonard J; Robinson, Gene E

2011-11-15

Worker honey bees undergo a socially regulated, highly stable lipid loss as part of their behavioral maturation. We used large-scale transcriptomic and proteomic experiments, physiological experiments and RNA interference to explore the mechanistic basis for this lipid loss. Lipid loss was associated with thousands of gene expression changes in abdominal fat bodies. Many of these genes were also regulated in young bees by nutrition during an initial period of lipid gain. Surprisingly, in older bees, which is when maximum lipid loss occurs, diet played less of a role in regulating fat body gene expression for components of evolutionarily conserved nutrition-related endocrine systems involving insulin and juvenile hormone signaling. By contrast, fat body gene expression in older bees was regulated more strongly by evolutionarily novel regulatory factors, queen mandibular pheromone (a honey bee-specific social signal) and vitellogenin (a conserved yolk protein that has evolved novel, maturation-related functions in the bee), independent of nutrition. These results demonstrate that conserved molecular pathways can be manipulated to achieve stable lipid loss through evolutionarily novel regulatory processes.

Modifications of coronary risk factors.

PubMed

Albu, Jeanine; Gottlieb, Sheldon H; August, Phyllis; Nesto, Richard W; Orchard, Trevor J

2006-06-19

In addition to the revascularization and glycemic management interventions assigned at random, the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) design includes the uniform control of major coronary artery disease risk factors, including dyslipidemia, hypertension, smoking, central obesity, and sedentary lifestyle. Target levels for risk factors were adjusted throughout the trial to comply with changes in recommended clinical practice guidelines. At present, the goals are low-density lipoprotein cholesterol <2.59 mmol/L (<100 mg/dL) with an optional goal of <1.81 mmol/L (<70 mg/dL); plasma triglyceride level <1.70 mmol/L (<150 mg/dL); blood pressure level <130 mm Hg systolic and <80 mm Hg diastolic; and smoking cessation treatment for all active smokers. Algorithms were developed for the pharmacologic management of dyslipidemia and hypertension. Dietary prescriptions for the management of glycemia, plasma lipid profiles, and blood pressure levels were adapted from existing clinical practice guidelines. Patients with a body mass index >25 were prescribed moderate caloric restriction; after the trial was under way, a lifestyle weight-management program was instituted. All patients were formally prescribed both endurance and resistance/flexibility exercises, individually adapted to their level of disability and fitness. Pedometers were distributed as a biofeedback strategy. Strategies to achieve the goals for risk factors were designed by BARI 2D working groups (lipid, cardiovascular and hypertension, and nonpharmacologic intervention) and the ongoing implementation of the strategies is monitored by lipid, hypertension, and lifestyle intervention management centers.

Pathophysiology of mitochondrial lipid oxidation: Role of 4-hydroxynonenal (4-HNE) and other bioactive lipids in mitochondria.

PubMed

Xiao, Mengqing; Zhong, Huiqin; Xia, Lin; Tao, Yongzhen; Yin, Huiyong

2017-10-01

Mitochondrial lipids are essential for maintaining the integrity of mitochondrial membranes and the proper functions of mitochondria. As the "powerhouse" of a cell, mitochondria are also the major cellular source of reactive oxygen species (ROS). Oxidative stress occurs when the antioxidant system is overwhelmed by overproduction of ROS. Polyunsaturated fatty acids in mitochondrial membranes are primary targets for ROS attack, which may lead to lipid peroxidation (LPO) and generation of reactive lipids, such as 4-hydroxynonenal. When mitochondrial lipids are oxidized, the integrity and function of mitochondria may be compromised and this may eventually lead to mitochondrial dysfunction, which has been associated with many human diseases including cancer, cardiovascular diseases, diabetes, and neurodegenerative diseases. How mitochondrial lipids are oxidized and the underlying molecular mechanisms and pathophysiological consequences associated with mitochondrial LPO remain poorly defined. Oxidation of the mitochondria-specific phospholipid cardiolipin and generation of bioactive lipids through mitochondrial LPO has been increasingly recognized as an important event orchestrating apoptosis, metabolic reprogramming of energy production, mitophagy, and immune responses. In this review, we focus on the current understanding of how mitochondrial LPO and generation of bioactive lipid mediators in mitochondria are involved in the modulation of mitochondrial functions in the context of relevant human diseases associated with oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

Altered lipid metabolism in brain injury and disorders.

PubMed

Adibhatla, Rao Muralikrishna; Hatcher, J F

2008-01-01

Deregulated lipid metabolism may be of particular importance for CNS injuries and disorders, as this organ has the highest lipid concentration next to adipose tissue. Atherosclerosis (a risk factor for ischemic stroke) results from accumulation of LDL-derived lipids in the arterial wall. Pro-inflammatory cytokines (TNF-alpha and IL-1), secretory phospholipase A2 IIA and lipoprotein-PLA2 are implicated in vascular inflammation. These inflammatory responses promote atherosclerotic plaques, formation and release of the blood clot that can induce ischemic stroke. TNF-alpha and IL-1 alter lipid metabolism and stimulate production of eicosanoids, ceramide, and reactive oxygen species that potentiate CNS injuries and certain neurological disorders. Cholesterol is an important regulator of lipid organization and the precursor for neurosteroid biosynthesis. Low levels of neurosteroids were related to poor outcome in many brain pathologies. Apolipoprotein E is the principal cholesterol carrier protein in the brain, and the gene encoding the variant Apolipoprotein E4 is a significant risk factor for Alzheimer's disease. Parkinson's disease is to some degree caused by lipid peroxidation due to phospholipases activation. Niemann-Pick diseases A and B are due to acidic sphingomyelinase deficiency, resulting in sphingomyelin accumulation, while Niemann-Pick disease C is due to mutations in either the NPC1 or NPC2 genes, resulting in defective cholesterol transport and cholesterol accumulation. Multiple sclerosis is an autoimmune inflammatory demyelinating condition of the CNS. Inhibiting phospholipase A2 attenuated the onset and progression of experimental autoimmune encephalomyelitis. The endocannabinoid system is hypoactive in Huntington's disease. Ethyl-eicosapetaenoate showed promise in clinical trials. Amyotrophic lateral sclerosis causes loss of motorneurons. Cyclooxygenase-2 inhibition reduced spinal neurodegeneration in amyotrophic lateral sclerosis transgenic mice

Blockade of lipid accumulation by silibinin in adipocytes and zebrafish.

PubMed

Suh, Hyung Joo; Cho, So Young; Kim, Eun Young; Choi, Hyeon-Son

2015-02-05

Silibinin is a compound present mainly in milk thistle. In this study, we investigated the mechanism by which silibinin suppresses adipogenesis of 3T3-L1 cells, and evaluated the anti-adipogenic effect of silibinin in zebrafish. Silibinin reduced lipid accumulation by downregulating adipogenic factors, such as, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer binding protein α (C/EBPα), and fatty acid-binding protein 4 (FABP4). The reduction of these adipogenic protein levels was associated with the regulation of early adipogenic factors, such as, C/EBPβ and Krüppel-like factor 2 (KLF2), and was reflected in downregulation of lipid synthetic enzymes. Silibinin arrested cells in the G0/G1 phase of the cell cycle, accompanied by downregulation of cyclins and upregulation of p27, a cell cycle inhibitor. These results correlated with the finding of deactivation of extracellular signal-regulated kinase (ERK) and AKT, a serine/threonine-specific kinase. In addition, silibinin activated AMP-activated protein kinase α (AMPKα) to inhibit fatty acid synthesis. As observed in 3T3-L1 cells, silibinin inhibited lipid accumulation in zebrafish with the reduction of adipogenic factors and triglyceride levels. Our data revealed that silibinin inhibited lipid accumulation in 3T3-L1 cells and zebrafish, and this inhibitory effect was associated with abrogation of early adipogenesis via regulation of cell cycle and AMPKα signaling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Blood coagulation, fibrinolytic activity and lipid profile in subclinical thyroid disease: subclinical hyperthyroidism increases plasma factor X activity.

PubMed

Erem, Cihangir

2006-03-01

Various abnormalities of coagulation and fibrinolysis occur in patients with thyroid diseases, and may range from subclinical laboratory abnormalities to clinically significant disorders of coagulation and, rarely, major haemorrhage or thromboembolism. The influence of subclinical hypothyroidism (SHypo) on haemostasis is controversial, both hypercoagulable and hypocoagulable states have been reported. A hypercoagulable state might be a risk factor for thromboembolic disease in SHypo. On the other hand, subclinical hyperthyroidism (SCHyper) is associated with enhanced cardiovascular risk. In the English literature, there are no studies on changes in coagulation and fibriolytic status in subjects with SCHyper. Therefore, the aim of the present study was to investigate the markers of endogenous coagulation and fibrinolysis, and to evaluate the relationships between serum lipid profile and thyroid hormones and these haemostatic parameters in subclinical thyroid patients. Various haemostatic parameters were investigated in 30 patients with SHypo and 20 patients with SCHyper and compared to 20 euthyroid controls. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, factors V, VII, VIII, IX and X activities, vWF, antithrombin III (AT III), protein C, protein S, tissue plasminogen activator (t-PA) and tissue plasminogen activator inhibitor-1 (PAI-1), as well as common lipid variables, were measured. The relationships between serum thyroid hormones and these haemostatic parameters were examined. Compared with the control subjects, only FX activity was significantly increased in patients with SCHyper (P < 0.01). Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly higher in patients with SHypo compared with the control group (P < 0.001 and P < 0.01, respectively). TC levels were significantly higher in patients with SCHyper than in controls (P < 0.05). No differences could be found in coagulation

Enhanced dissolved lipid production as a response to the sea surface warming

NASA Astrophysics Data System (ADS)

Novak, Tihana; Godrijan, Jelena; Pfannkuchen, Daniela Marić; Djakovac, Tamara; Mlakar, Marina; Baricevic, Ana; Tanković, Mirta Smodlaka; Gašparović, Blaženka

2018-04-01

The temperature increase in oceans reflects on marine ecosystem functioning and surely has consequences on the marine carbon cycle and carbon sequestration. In this study, we examined dissolved lipid, lipid classes and dissolved organic carbon (DOC) production in the northern Adriatic Sea, isolated diatom Chaetoceros pseudocurvisetus batch cultures grown in a wide temperature range (10-30 °C) and in contrasting nutrient regimes, phosphorus (P)-depleted and P-replete conditions. Additionally, lipids and DOC were analyzed in the northern Adriatic (NA) in two stations characterized with different P availability, occupied from February to August 2010 that covered a temperature range from 9.3 to 31.1 °C. To gain insight into factors governing lipid and lipid classes' production in the NA, apart from temperature (T), Chlorophyll a, phytoplankton community abundance and structure, nutrient concentrations were measured together with hydrographic parameters. We found enhanced accumulation of dissolved lipids, particulary glycolipids, with increasing T, especially during the highest in situ temperature. The effect of T on enhanced dissolved lipid release is much more pronounced under P-deplete conditions indicating that oligotrophic regions might be more vulnerable to T rise. Temperature between 25 and 30 °C is a threshold T range for C. pseudocurvisetus, at which a significant part of lipid production is directed toward the dissolved phase. Unlike monocultures, there are multiple factors influencing produced lipid composition, distribution and cycling in the NA that may counteract the T influence. The possible role of enhanced dissolved lipid concentration for carbon sequestration at elevated T is discussed. On the one hand, lipids are buoyant and do not sink, which enhances their retention at the surface layer. In addition, they are surface active, and therefore prone to adsorb on sinking particles, contributing to the C sequestration.

Lens lipids.

PubMed

Zelenka, P S

1984-11-01

Lens cells can synthesize, degrade, and remodel lipids. Endogenous lipid synthesis, in conjunction with uptake of exogenous cholesterol and certain fatty acids, leads to the formation of a plasma membrane that is especially rich in sphingomyelin, cholesterol, and long-chain saturated fatty acids. As a result of this unusual lipid composition, lens membranes have very low fluidity, which is restricted even further by lipid-protein interactions. The composition and metabolism of membrane lipids may affect the formation of various types of cataracts. Diets rich in vegetable oils offer some protection against the formation of osmotic cataracts and the hereditary cataract of the RCS rat, although the mechanism of this effect is not clear. Vitamin E also protects against the formation of several types of cataract in vivo and in vitro, suggesting that lipid peroxidation may play a role in cataractogenesis. Certain drugs which inhibit lipid synthesis or degradation are cataractogenic, and a deficiency in cataractogenic, and a deficiency in phosphatidylserine is associated with a loss of Na+/K+ ATPase activity in several types of cataract. Human senile cataracts show a marked loss of protein-lipid interactions, although the overall lipid composition is normal. This loss of protein-lipid interactions may be related to oxidative damage to membrane-associated proteins. Interestingly, the decrease in the fluidity of lens membranes with age would counteract the formation of aqueous pores in the membrane, which can result from the oxidative cross-linking of membrane-associated proteins. Certain pathways of lipid metabolism seem to have regulatory functions. Among these are phosphatidylinositol turnover, phosphatidylethanolamine methylation, and arachidonic acid metabolism. All of these pathways function in the lens. Phosphatidylinositol turnover is correlated with the rate of lens epithelial cell division, while phosphatidylethanolamine methylation seems to be related to the

Polyunsaturated Fatty Acids in Lipid Bilayers and Tubules

NASA Astrophysics Data System (ADS)

Hirst, Linda S.; Yuan, Jing; Pramudya, Yohannes; Nguyen, Lam T.

2007-03-01

Omega-3 polyunsaturated fatty acids (PUFAs) are found in a variety of biological membranes and have been implicated with lipid raft formation and possible function, typical molecules include DHA (Docosahexanoic Acid) and AA (Alphalinoleic Acid) which have been the focus of considerable attention in recent years. We are interested in the phase behavior of these molecules in the lipid bilayer. The addition of lipid molecules with polyunsaturated chains has a clear effect on the fluidity and curvature of the membrane and we investigate the effects the addition of polyunsaturated lipids on bilayer structure and tubule formation. Self-assembled cylindrical lipid tubules have attracted considerable attention because of their interesting structures and potential technological applications. Using x-ray diffraction techniques, Atomic Force Microscopy and confocal fluorescence imaging, both symmetric and mixed chain lipids were incorporated into model membranes and the effects on bilayer structure and tubule formation investigated.

Wheat leaf lipids during heat stress: II. Lipids experiencing coordinated metabolism are detected by analysis of lipid co-occurrence.

PubMed

Narayanan, Sruthi; Prasad, P V Vara; Welti, Ruth

2016-03-01

Identifying lipids that experience coordinated metabolism during heat stress would provide information regarding lipid dynamics under stress conditions and assist in developing heat-tolerant wheat varieties. We hypothesized that co-occurring lipids, which are up-regulated or down-regulated together through time during heat stress, represent groups that can be explained by coordinated metabolism. Wheat plants (Triticum aestivum L.) were subjected to 12 days of high day and/or night temperature stress, followed by a 4-day recovery period. Leaves were sampled at four time points, and 165 lipids were measured by electrospray ionization-tandem mass spectrometry. Correlation analysis of lipid levels in 160 leaf samples from each of two wheat genotypes revealed 13 groups of lipids. Lipids within each group co-occurred through the high day and night temperature stress treatments. The lipid groups can be broadly classified as groups containing extraplastidic phospholipids, plastidic glycerolipids, oxidized glycerolipids, triacylglycerols, acylated sterol glycosides and sterol glycosides. Current knowledge of lipid metabolism suggests that the lipids in each group co-occur because they are regulated by the same enzyme(s). The results suggest that increases in activities of desaturating, oxidizing, glycosylating and acylating enzymes lead to simultaneous changes in levels of multiple lipid species during high day and night temperature stress in wheat. © 2015 John Wiley & Sons Ltd.

Lipases as biocatalysts for the synthesis of structured lipids.

PubMed

Jala, Ram Chandra Reddy; Hu, Peng; Yang, Tiankui; Jiang, Yuanrong; Zheng, Yan; Xu, Xuebing

2012-01-01

Structured lipids (SL) are broadly referred to as modified or synthetic oils and fats or lipids with functional or pharmaceutical applications. Some structured lipids, such as triglycerides that contain both long-chain (mainly essential) fatty acids and medium- or short-chain fatty acids and also artificial products that mimic the structure of natural materials, namely human milk fat substitutes and cocoa butter equivalents, have been discussed. Further, other modified or synthetic lipids, such as structured phospholipids and synthetic phenolic lipids are also included in this chapter. For all the products described in this chapter, enzymatic production in industry has been already conducted in one way or another. Cocoa butter equivalents, healthy oil containing medium-chain fatty acids, phosphatidyl serine, and phenol lipids from enzyme technology have been reported for commercial operation. As the demand for better quality functional lipids is increasing, the production of structured lipids becomes an interesting area. Thus, in this chapter we have discussed latest developments as well as present industrial situation of all commercially important structured lipids.

PPAR-γ activation by Tityus serrulatus venom regulates lipid body formation and lipid mediator production.

PubMed

Zoccal, Karina Furlani; Paula-Silva, Francisco Wanderley Garcia; Bitencourt, Claudia da Silva; Sorgi, Carlos Artério; Bordon, Karla de Castro Figueiredo; Arantes, Eliane Candiani; Faccioli, Lúcia Helena

2015-01-01

Tityus serrulatus venom (TsV) consists of numerous peptides with different physiological and pharmacological activities. Studies have shown that scorpion venom increases pro-inflammatory cytokine production, contributing to immunological imbalance, multiple organ dysfunction, and patient death. We have previously demonstrated that TsV is a venom-associated molecular pattern (VAMP) recognized by TLRs inducing intense inflammatory reaction through the production of pro-inflammatory cytokines and arachidonic acid-derived lipid mediators prostaglandin (PG)E2 and leukotriene (LT)B4. Lipid bodies (LBs) are potential sites for eicosanoid production by inflammatory cells. Moreover, recent studies have shown that the peroxisome proliferator-activated receptor gamma (PPAR-γ) is implicated in LB formation and acts as an important modulator of lipid metabolism during inflammation. In this study, we used murine macrophages to evaluate whether the LB formation induced by TsV after TLR recognition correlates with lipid mediator generation by macrophages and if it occurs through PPAR-γ activation. We demonstrate that TsV acts through TLR2 and TLR4 stimulation and PPAR-γ activation to induce LB formation and generation of PGE2 and LTB4. Our data also show that PPAR-γ negatively regulates the pro-inflammatory NF-κB transcription factor. Based on these results, we suggest that during envenomation, LBs constitute functional organelles for lipid mediator production through signaling pathways that depend on cell surface and nuclear receptors. These findings point to the inflammatory mechanisms that might also be triggered during human envenomation by TsV. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relations of long-term and contemporary lipid levels and lipid genetic risk scores with coronary artery calcium in the framingham heart study.

PubMed

Tsao, Connie W; Preis, Sarah Rosner; Peloso, Gina M; Hwang, Shih-Jen; Kathiresan, Sekar; Fox, Caroline S; Cupples, L Adrienne; Hoffmann, Udo; O'Donnell, Christopher J

2012-12-11

This study evaluated the association of timing of lipid levels and lipid genetic risk score (GRS) with subclinical atherosclerosis. Atherosclerosis is a slowly progressive disorder influenced by suboptimal lipid levels. Long-term versus contemporary lipid levels may more strongly impact the development of coronary artery calcium (CAC). Framingham Heart Study (FHS) Offspring Cohort participants (n = 1,156, 44% male, 63 ± 9 years) underwent serial fasting lipids (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein, and triglycerides), Exam 1 (1971 to 1975) to Exam 7 (1998 to 2001). FHS Third Generation Cohort participants (n = 1,954, 55% male, 45 ± 6 years) had fasting lipid profiles assessed, 2002 to 2005. Computed tomography (2002 to 2005) measured CAC. Lipid GRSs were computed from significantly associated single-nucleotide polymorphisms. The association between early, long-term average, and contemporary lipids, and lipid GRS with elevated CAC was assessed using logistic regression. In FHS Offspring, Exam 1 and long-term average as compared with Exam 7 lipid measurements, including untreated lipid levels, were strongly associated with elevated CAC. In the FHS Third Generation, contemporary lipids were associated with CAC. The LDL-C GRS was associated with CAC (age-/sex-adjusted odds ratio: 1.14, 95% confidence interval: 1.00 to 1.29, p = 0.04). However, addition of the GRS to the lipid models did not result in a significant increase in the odds ratio or C-statistic for any lipid measure. Early and long-term average lipid levels, as compared with contemporary measures, are more strongly associated with elevated CAC. Lipid GRS was associated with lipid levels but did not predict elevated CAC. Adult early and long-term average lipid levels provide important information when assessing subclinical atherosclerosis and cardiovascular risk. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Epidermal lipid in several cetacean species: ultrastructural observations.

PubMed

Pfeiffer, C J; Jones, F M

1993-09-01

The ultrastructure of the skin of four cetacean species, bottlenose dolphin (Tursiops truncatus) long-finned pilot whale (Globicephala melaena), humpback whale (Megaptera novaeangliae), and fin whale (Balaenoptera physalus) was investigated with particular reference to epidermal lipid. It has already been established that massive lipid reservoirs exist in whales, that the biochemical structures of cetacean lipids are unique, and that unusual intracellular lipid droplets appear in the epidermis. We report here some novel findings on scanning electron microscopic morphology of epidermal lipid, and on its ultrastructural morphology in general and specialized integumentary sites, including species not previously investigated. The intracellular epidermal lipid droplets were more extensive than lamellar body-derived intercellular lipid which is within the interstices of stratum externum cells. The intracellular droplets were spherical, highly variable in size ranging from 0.24 micron to 3.0 microns in diameter, appeared singly or were aggregated in cytoplasmic cavitations, and often were closely associated with epidermal cell nuclei. Evidence for exocytosis of the intracellular droplets was not observed. Significant numbers of intracellular lipid droplets are not observed in the epidermis of terrestrial mammals, so their presence is one of several aquatic specializations of the cetacean integument. Its full significance remains obscure, but it is more probably associated with epidermal cell metabolism than with secretion of lipid.

SAXS Study of Sterically Stabilized Lipid Nanocarriers Functionalized by DNA

NASA Astrophysics Data System (ADS)

Angelov, Borislav; Angelova, Angelina; Filippov, Sergey; Karlsson, Göran; Terrill, Nick; Lesieur, Sylviane; Štěpánek, Petr

2012-03-01

The structure of novel spontaneously self-assembled plasmid DNA/lipid complexes is investigated by means of synchrotron radiation small-angle X-ray scattering (SAXS) and Cryo-TEM imaging. Liquid crystalline (LC) hydrated lipid systems are prepared using the non-ionic lipids monoolein and DOPE-PEG2000 and the cationic amphiphile CTAB. The employed plasmid DNA (pDNA) is encoding for the human protein brain-derived neurotrophic factor (BDNF). A coexistence of nanoparticulate objects with different LC inner organizations is established. A transition from bicontinuous membrane sponges, cubosome intermediates and unilamelar liposomes to multilamellar vesicles, functionalized by pDNA, is favoured upon binding and compaction of pBDNF onto the cationic PEGylated lipid nanocarriers. The obtained sterically stabilized multicompartment nanoobjects, with confined supercoiled plasmid DNA (pBDNF), are important in the context of multicompartment lipid nanocarriers of interest for gene therapy of neurodegenerative diseases.

Cationic cell-penetrating peptide binds to planar lipid bilayers containing negatively charged lipids but does not induce conductive pores.

PubMed

Gurnev, Philip A; Yang, Sung-Tae; Melikov, Kamran C; Chernomordik, Leonid V; Bezrukov, Sergey M

2013-05-07

Using a cation-selective gramicidin A channel as a sensor of the membrane surface charge, we studied interactions of oligoarginine peptide R9C, a prototype cationic cell-penetrating peptide (CPP), with planar lipid membranes. We have found that R9C sorption to the membrane depends strongly on its lipid composition from virtually nonexistent for membranes made of uncharged lipids to very pronounced for membranes containing negatively charged lipids, with charge overcompensation at R9C concentrations exceeding 1 μM. The sorption was reversible as it was removed by addition of polyanionic dextran sulfate to the membrane bathing solution. No membrane poration activity of R9C (as would be manifested by increased bilayer conductance) was detected in the charged or neutral membranes, including those with asymmetric negative/neutral and negative/positive lipid leaflets. We conclude that interaction of R9C with planar lipid bilayers does not involve pore formation in all studied lipid combinations up to 20 μM peptide concentration. However, R9C induces leakage of negatively charged but not neutral liposomes in a process that involves lipid mixing between liposomes. Our findings suggest that direct traversing of CPPs through the uncharged outer leaflet of the plasma membrane bilayer is unlikely and that permeabilization necessarily involves both anionic lipids and CPP-dependent fusion between opposing membranes. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Charge-reversal Lipids, Peptide-based Lipids, and Nucleoside-based Lipids for Gene Delivery

PubMed Central

LaManna, Caroline M.; Lusic, Hrvoje; Camplo, Michel; McIntosh, Thomas J.; Barthélémy, Philippe; Grinstaff, Mark W.

2013-01-01

Conspectus Twenty years after gene therapy was introduced in the clinic, advances in the technique continue to garner headlines as successes pique the interest of clinicians, researchers, and the public. Gene therapy’s appeal stems from its potential to revolutionize modern medical therapeutics by offering solutions to a myriad of diseases by tailoring the treatment to a specific individual’s genetic code. Both viral and non-viral vectors have been used in the clinic, but the low transfection efficiencies when utilizing non-viral vectors have lead to an increased focus on engineering new gene delivery vectors. To address the challenges facing non-viral or synthetic vectors, specifically lipid-based carriers, we have focused on three main themes throughout our research: 1) that releasing the nucleic acid from the carrier will increase gene transfection; 2) that utilizing biologically inspired designs, such as DNA binding proteins, to create lipids with peptide-based headgroups will improve delivery; and 3) that mimicking the natural binding patterns observed within DNA, by using lipids having a nucleoside headgroup, will give unique supramolecular assembles with high transfection efficiency. The results presented in this Account demonstrate that cellular uptake and transfection efficacy can be improved by engineering the chemical components of the lipid vectors to enhance nucleic acid binding and release kinetics. Specifically, our research has shown that the incorporation of a charge-reversal moiety to initiate change of the lipid from positive to negative net charge during the transfection process improves transfection. In addition, by varying the composition of the spacer (rigid, flexible, short, long, and aromatic) between the cationic headgroup and the hydrophobic chains, lipids can be tailored to interact with different nucleic acids (DNA, RNA, siRNA) and accordingly affect delivery, uptake outcomes, and transfection efficiency. Introduction of a peptide

Imaging of blood plasma coagulation at supported lipid membranes.

PubMed

Faxälv, Lars; Hume, Jasmin; Kasemo, Bengt; Svedhem, Sofia

2011-12-15

The blood coagulation system relies on lipid membrane constituents to act as regulators of the coagulation process upon vascular trauma, and in particular the 2D configuration of the lipid membranes is known to efficiently catalyze enzymatic activity of blood coagulation factors. This work demonstrates a new application of a recently developed methodology to study blood coagulation at lipid membrane interfaces with the use of imaging technology. Lipid membranes with varied net charges were formed on silica supports by systematically using different combinations of lipids where neutral phosphocholine (PC) lipids were mixed with phospholipids having either positively charged ethylphosphocholine (EPC), or negatively charged phosphatidylserine (PS) headgroups. Coagulation imaging demonstrated that negatively charged SiO(2) and membrane surfaces exposing PS (obtained from liposomes containing 30% of PS) had coagulation times which were significantly shorter than those for plain PC membranes and EPC exposing membrane surfaces (obtained from liposomes containing 30% of EPC). Coagulation times decreased non-linearly with increasing negative surface charge for lipid membranes. A threshold value for shorter coagulation times was observed below a PS content of ∼6%. We conclude that the lipid membranes on solid support studied with the imaging setup as presented in this study offers a flexible and non-expensive solution for coagulation studies at biological membranes. It will be interesting to extend the present study towards examining coagulation on more complex lipid-based model systems. Copyright © 2011 Elsevier Inc. All rights reserved.

Regulation of AMPA receptor localization in lipid rafts

PubMed Central

Hou, Qingming; Huang, Yunfei; Amato, Stephen; Snyder, Solomon H.; Huganir, Richard L.; Man, Heng-Ye

2009-01-01

Lipid rafts are special microdomains enriched in cholesterol, sphingolipids and certain proteins, and play important roles in a variety of cellular functions including signal transduction and protein trafficking. We report that in cultured cortical and hippocampal neurons the distribution of lipid rafts is development-dependent. Lipid rafts in mature neurons exist on the entire cell-surface and display a high degree of mobility. AMPA receptors co-localize and associate with lipid rafts in the plasma membrane. The association of AMPARs with rafts is under regulation; through the NOS–NO pathway, NMDA receptor activity increases AMPAR localization in rafts. During membrane targeting, AMPARs insert into or at close proximity of the surface raft domains. Perturbation of lipid rafts dramatically suppresses AMPA receptor exocytosis, resulting in significant reduction in AMPAR cell-surface expression. PMID:18411055

Lipid diffusion in alcoholic environment.

PubMed

Rifici, Simona; Corsaro, Carmelo; Crupi, Cristina; Nibali, Valeria Conti; Branca, Caterina; D'Angelo, Giovanna; Wanderlingh, Ulderico

2014-08-07

We have studied the effects of a high concentration of butanol and octanol on the phase behavior and on the lateral mobility of 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC) by means of differential scanning calorimetry and pulsed-gradient stimulated-echo (PGSTE) NMR spectroscopy. A lowering of the lipid transition from the gel to the liquid-crystalline state for the membrane-alcohol systems has been observed. NMR measurements reveal three distinct diffusions in the DPPC-alcohol systems, characterized by a high, intermediate, and slow diffusivity, ascribed to the water, the alcohol, and the lipid, respectively. The lipid diffusion process is promoted in the liquid phase while it is hindered in the interdigitated phase due to the presence of alcohols. Furthermore, in the interdigitated phase, lipid lateral diffusion coefficients show a slight temperature dependence. To the best of our knowledge, this is the first time that lateral diffusion coefficients on alcohol with so a long chain, and at low temperatures, are reported. By the Arrhenius plots of the temperature dependence of the diffusion coefficients, we have evaluated the apparent activation energy in both the liquid and in the interdigitated phase. The presence of alcohol increases this value in both phases. An explanation in terms of a free volume model that takes into account also for energy factors is proposed.

Differential Effects of Oral and Intravenous Lipid Administration on Key Molecules Related to Energy Homeostasis

PubMed Central

Vamvini, Maria T.; Hamnvik, Ole-Petter; Sahin-Efe, Ayse; Gavrieli, Anna; Dincer, Fadime; Farr, Olivia M.

2016-01-01

Context: The spectrum of lipid-induced changes in the secretion of hormones important in energy homeostasis has not yet been fully elucidated. Objective: To identify potential incretin-like effects in response to lipid administration, we examined the short-term effect of iv vs oral lipids on key molecules regulating energy homeostasis. Design, Intervention, and Participants: After a 10-hour overnight fast, 26 subjects were randomized to receive an oral lipid load, a 10% iv lipid emulsion, a 20% iv lipid emulsion, or an iv saline infusion. We obtained blood samples at 30-minute intervals for the first 2 hours and hourly thereafter for a total of 6 hours. Main Outcome Measures: Circulating levels of insulin, glucose, c-peptide, free fatty acids, incretins (glucagon-like peptide-1, gastric inhibitory polypeptide), glucagon, peptide YY, ghrelin, fibroblast growth factor 21, fetuin A, irisin, omentin, and adiponectin were measured. Results: Oral lipid ingestion resulted in higher glucagon-like peptide-1, gastric inhibitory polypeptide, glucagon, and peptide YY levels, compared with the other three groups (incremental area under the curve P = .003, P < .001, P < .001, P < .001, respectively). The 20% lipid emulsion, leading to higher free fatty acid levels, resulted in greater insulin, c-peptide, and fibroblast growth factor 21 responses compared with placebo and the other two groups (incremental area under the curve P = .002, P = .005, P < .001, P < .001, respectively). Omentin, adiponectin, fetuin A, and irisin levels were not affected by either mode of lipid administration. Conclusions: Metabolic responses to lipids depend on the route of administration. Only iv lipids trigger a dose-dependent fibroblast growth factor 21 secretion, which is nonglucagon mediated. Intravenous lipids also induce hyperinsulinemia without concurrent decreases in glucose, a phenomenon observed in insulin-resistant states. Orally administered lipids mostly affect gastrointestinal tract

GPS-Lipid: a robust tool for the prediction of multiple lipid modification sites.

PubMed

Xie, Yubin; Zheng, Yueyuan; Li, Hongyu; Luo, Xiaotong; He, Zhihao; Cao, Shuo; Shi, Yi; Zhao, Qi; Xue, Yu; Zuo, Zhixiang; Ren, Jian

2016-06-16

As one of the most common post-translational modifications in eukaryotic cells, lipid modification is an important mechanism for the regulation of variety aspects of protein function. Over the last decades, three classes of lipid modifications have been increasingly studied. The co-regulation of these different lipid modifications is beginning to be noticed. However, due to the lack of integrated bioinformatics resources, the studies of co-regulatory mechanisms are still very limited. In this work, we developed a tool called GPS-Lipid for the prediction of four classes of lipid modifications by integrating the Particle Swarm Optimization with an aging leader and challengers (ALC-PSO) algorithm. GPS-Lipid was proven to be evidently superior to other similar tools. To facilitate the research of lipid modification, we hosted a publicly available web server at http://lipid.biocuckoo.org with not only the implementation of GPS-Lipid, but also an integrative database and visualization tool. We performed a systematic analysis of the co-regulatory mechanism between different lipid modifications with GPS-Lipid. The results demonstrated that the proximal dual-lipid modifications among palmitoylation, myristoylation and prenylation are key mechanism for regulating various protein functions. In conclusion, GPS-lipid is expected to serve as useful resource for the research on lipid modifications, especially on their co-regulation.

Very large database of lipids: rationale and design.

PubMed

Martin, Seth S; Blaha, Michael J; Toth, Peter P; Joshi, Parag H; McEvoy, John W; Ahmed, Haitham M; Elshazly, Mohamed B; Swiger, Kristopher J; Michos, Erin D; Kwiterovich, Peter O; Kulkarni, Krishnaji R; Chimera, Joseph; Cannon, Christopher P; Blumenthal, Roger S; Jones, Steven R

2013-11-01

Blood lipids have major cardiovascular and public health implications. Lipid-lowering drugs are prescribed based in part on categorization of patients into normal or abnormal lipid metabolism, yet relatively little emphasis has been placed on: (1) the accuracy of current lipid measures used in clinical practice, (2) the reliability of current categorizations of dyslipidemia states, and (3) the relationship of advanced lipid characterization to other cardiovascular disease biomarkers. To these ends, we developed the Very Large Database of Lipids (NCT01698489), an ongoing database protocol that harnesses deidentified data from the daily operations of a commercial lipid laboratory. The database includes individuals who were referred for clinical purposes for a Vertical Auto Profile (Atherotech Inc., Birmingham, AL), which directly measures cholesterol concentrations of low-density lipoprotein, very low-density lipoprotein, intermediate-density lipoprotein, high-density lipoprotein, their subclasses, and lipoprotein(a). Individual Very Large Database of Lipids studies, ranging from studies of measurement accuracy, to dyslipidemia categorization, to biomarker associations, to characterization of rare lipid disorders, are investigator-initiated and utilize peer-reviewed statistical analysis plans to address a priori hypotheses/aims. In the first database harvest (Very Large Database of Lipids 1.0) from 2009 to 2011, there were 1 340 614 adult and 10 294 pediatric patients; the adult sample had a median age of 59 years (interquartile range, 49-70 years) with even representation by sex. Lipid distributions closely matched those from the population-representative National Health and Nutrition Examination Survey. The second harvest of the database (Very Large Database of Lipids 2.0) is underway. Overall, the Very Large Database of Lipids database provides an opportunity for collaboration and new knowledge generation through careful examination of granular lipid data on

2017 Taiwan lipid guidelines for high risk patients.

PubMed

Li, Yi-Heng; Ueng, Kwo-Chang; Jeng, Jiann-Shing; Charng, Min-Ji; Lin, Tsung-Hsien; Chien, Kuo-Liong; Wang, Chih-Yuan; Chao, Ting-Hsing; Liu, Ping-Yen; Su, Cheng-Huang; Chien, Shih-Chieh; Liou, Chia-Wei; Tang, Sung-Chun; Lee, Chun-Chuan; Yu, Tse-Ya; Chen, Jaw-Wen; Wu, Chau-Chung; Yeh, Hung-I

2017-04-01

In Taiwan, the prevalence of hyperlipidemia increased due to lifestyle and dietary habit changes. Low density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein cholesterol (non-HDL-C) are all significant predicting factors of coronary artery disease in Taiwan. We recognized that lipid control is especially important in patients with existed atherosclerotic cardiovascular diseases (ASCVD), including coronary artery disease (CAD), ischemic stroke and peripheral arterial disease (PAD). Because the risk of ASCVD is high in patients with diabetes mellitus (DM), chronic kidney disease (CKD) and familial hypercholesterolemia (FH), lipid control is also necessary in these patients. Lifestyle modification is the first step to control lipid. Weight reduction, regular physical exercise and limitation of alcohol intake all reduce triglyceride (TG) levels. Lipid-lowering drugs include HMG-CoA reductase inhibitors (statins), cholesterol absorption inhibitors (ezetimibe), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, nicotinic acids (niacin), fibric acids derivatives (fibrates), and long-chain omega-3 fatty acids. Statin is usually the first line therapy. Combination therapy with statin and other lipid-lowering agents may be considered in some clinical settings. For patients with acute coronary syndrome (ACS) and stable CAD, LDL-C < 70 mg/dL is the major target. A lower target of LDL-C <55 mg/dL can be considered in ACS patients with DM. After treating LDL-C to target, non-HDL-C can be considered as a secondary target for patients with TG ≥ 200 mg/dL. The suggested non-HDL-C target is < 100 mg/dL in ACS and CAD patients. For patients with ischemic stroke or transient ischemic attack presumed to be of atherosclerotic origin, statin therapy is beneficial and LDL-C < 100 mg/dL is the suggested target. For patients with symptomatic carotid stenosis or intracranial arterial stenosis, in addition to antiplatelets and blood pressure control, LDL

Lipids as a principle for the identification of Archaebacteria

NASA Technical Reports Server (NTRS)

Tornabene, T. G.; Lloyd, R. E.; Holzer, G.; Oro, J.

1980-01-01

The 'Archaebacteria' consist of several distinct subgroups including methanogens, extreme halophiles and specific thermoacidophiles. These bacteria are distinct from other bacteria with respect to their characteristic RNA compositions, the absence of muramic acid in the cell walls and the predominance of nonsaponifable lipids. The lipid composition of the Archaebacteria consists of isoprenoid and hydroisoprenoid hydrocarbons and isopranyl glycerol ether lipids. The pathways for the biosynthesis of the lipid components are those shared by most microorganisms and demonstrate a close relationship; however, an independent line of descent is indicated by the formation of the isopranyl glycerol ether lipids. This discontinuity formulates a point for delineating the early stages of biological evolution and for dividing bacteria into two subgroups.

Lxr-driven enterocyte lipid droplet formation delays transport of ingested lipids.

PubMed

Cruz-Garcia, Lourdes; Schlegel, Amnon

2014-09-01

Liver X receptors (Lxrs) are master regulators of cholesterol catabolism, driving the elimination of cholesterol from the periphery to the lumen of the intestine. Development of pharmacological agents to activate Lxrs has been hindered by synthetic Lxr agonists' induction of hepatic lipogenesis and hypertriglyceridemia. Elucidating the function of Lxrs in regulating enterocyte lipid handling might identify novel aspects of lipid metabolism that are pharmacologically amenable. We took a genetic approach centered on the single Lxr gene nr1h3 in zebrafish to study the role of Lxr in enterocyte lipid metabolism. Loss of nr1h3 function causes anticipated gene regulatory changes and cholesterol intolerance, collectively reflecting high evolutionary conservation of zebrafish Lxra function. Intestinal nr1h3 activation delays transport of absorbed neutral lipids, with accumulation of neutral lipids in enterocyte cytoplasmic droplets. This delay in transport of ingested neutral lipids protects animals from hypercholesterolemia and hepatic steatosis induced by a high-fat diet. On a gene regulatory level, Lxra induces expression of acsl3a, which encodes acyl-CoA synthetase long-chain family member 3a, a lipid droplet-anchored protein that directs fatty acyl chains into lipids. Forced overexpression of acls3a in enterocytes delays, in part, the appearance of neutral lipids in the vasculature of zebrafish larvae. Activation of Lxr in the intestine cell-autonomously regulates the rate of delivery of absorbed lipids by inducting a temporary lipid intestinal droplet storage depot. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

Lipid nanoparticle interactions and assemblies

NASA Astrophysics Data System (ADS)

Preiss, Matthew Ryan

Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron

Antibacterial characteristics of newly developed amphiphilic lipids and DNA-lipid complexes against bacteria.

PubMed

Inoue, Y; Fukushima, T; Hayakawa, T; Takeuchi, H; Kaminishi, H; Miyazaki, K; Okahata, Y

2003-05-01

The purpose of this study was to investigate the antibacterial activity of newly developed amphiphilic lipids and DNA/lipid complexes against two types of oral bacteria and two types of hospital infection bacteria. Nine amphiphilic lipids were quantitatively prepared from the reaction of n-alkyl alcohol, alpha-amino acids, and p-toluenesulfonic acid. Nine DNA-lipid complexes were prepared by the simple mixing of DNA and amphiphilic lipids. The DNA-lipid complexes were insoluble in water. The antibacterial activity of lipids and DNA-lipid complexes against Porphyromonas gingivalis, Streptococcus mutans, Staphylococcus aureus, and Pseudomonas aeruginosa were evaluated by the disk-diffusion method. Seven artificial lipids showed antibacterial behavior; in particular, the lipids prepared from n-decyl alcohol and glycine and from n-decyl alcohol and L-alanine showed antibacterial activity against the four bacterial strains used in this study. On the other hand, the lipids of glutamic acid derivatives did not show any antibacterial activity against the four bacteria strains except for the lipid with an n-octyl group. Five DNA-lipid complexes also had an antibacterial effect. The complex prepared from DNA and glycine decyl ester p-toluenesulfonic acid salt exhibited antibacterial activity against the four types of bacteria strains. In this study it was found that lipids and DNA-lipid complexes with a mono-decyl group or a mono-dodecyl group have more favorable antibacterial activity. Copyright 2003 Wiley Periodicals, Inc.

Parenteral nutrition-associated liver disease and lipid emulsions.

PubMed

Zugasti Murillo, Ana; Petrina Jáuregui, Estrella; Elizondo Armendáriz, Javier

2015-01-01

Parenteral nutrition-associated liver disease (PNALD) is a particularly important problem in patients who need this type of nutritional support for a long time. Prevalence of the condition is highly variable depending on the series, and its clinical presentation is different in adults and children. The etiology of PNALD is not well defined, and participation of several factors at the same time has been suggested. When a bilirubin level >2 mg/dl is detected for a long time, other causes of liver disease should be ruled out and risk factors should be minimized. The composition of lipid emulsions used in parenteral nutrition is one of the factors related to PNALD. This article reviews the different types of lipid emulsions and the potential benefits of emulsions enriched with omega-3 fatty acids. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Localization and Ordering of Lipids Around Aquaporin-0: Protein and Lipid Mobility Effects.

PubMed

Briones, Rodolfo; Aponte-Santamaría, Camilo; de Groot, Bert L

2017-01-01

Hydrophobic matching, lipid sorting, and protein oligomerization are key principles by which lipids and proteins organize in biological membranes. The Aquaporin-0 channel (AQP0), solved by electron crystallography (EC) at cryogenic temperatures, is one of the few protein-lipid complexes of which the structure is available in atomic detail. EC and room-temperature molecular dynamics (MD) of dimyristoylglycerophosphocholine (DMPC) annular lipids around AQP0 show similarities, however, crystal-packing and temperature might affect the protein surface or the lipids distribution. To understand the role of temperature, lipid phase, and protein mobility in the localization and ordering of AQP0-lipids, we used MD simulations of an AQP0-DMPC bilayer system. Simulations were performed at physiological and at DMPC gel-phase temperatures. To decouple the protein and lipid mobility effects, we induced gel-phase in the lipids or restrained the protein. We monitored the lipid ordering effects around the protein. Reducing the system temperature or inducing lipid gel-phase had a marginal effect on the annular lipid localization. However, restraining the protein mobility increased the annular lipid localization around the whole AQP0 surface, resembling EC. The distribution of the inter-phosphate and hydrophobic thicknesses showed that stretching of the DMPC annular layer around AQP0 surface is the mechanism that compensates the hydrophobic mismatch in this system. The distribution of the local area-per-lipid and the acyl-chain order parameters showed particular fluid- and gel-like areas that involved several lipid layers. These areas were in contact with the surfaces of higher and lower protein mobility, respectively. We conclude that the AQP0 surfaces induce specific fluid- and gel-phase prone areas. The presence of these areas might guide the AQP0 lipid sorting interactions with other membrane components, and is compatible with the squared array oligomerization of AQP0 tetramers

Cholesterol-based cationic lipids for gene delivery: contribution of molecular structure factors to physico-chemical and biological properties.

PubMed

Sheng, Ruilong; Luo, Ting; Li, Hui; Sun, Jingjing; Wang, Zhao; Cao, Amin

2014-04-01

In this work, we prepared a series of cholesterol-based cationic (Cho-cat) lipids bearing cholesterol hydrophobe, natural amino acid headgroups (lysine/histidine) and linkage (carbonate ester/ether) bonds. In which, the natural amino acid headgroups made dominant contribution to their physico-chemical and biological properties. Among the lipids, the l-lysine headgroup bearing lipids (Cho-es/et-Lys) showed higher pDNA binding affinity and were able to form larger sized and higher surface charged lipoplexes than that of l-histidine headgroup bearing lipids (Cho-es/et-His), they also demonstrated higher transfection efficacy and higher membrane disruption capacities than that of their l-histidine headgroup bearing counterparts. However, compared to the contributions of the headgroups, the (carbonate ester/ether) linkage bonds showed much less affects. Besides, it could be noted that, Cho-es/et-Lys lipids exhibited very high luciferase gene transfection efficiency that almost reached the transfection level of "gold standard" bPEI-25k, made them potential transfection reagents for practical application. Moreover, the results facilitated the understanding for the structure-activity relationship of the cholesterol-based cationic lipids, and also paved a simple and efficient way for achieving high transfection efficiency by modification of suitable headgroups on lipid gene carriers. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of SNPs at newly identified lipids loci on blood lipid levels and risk of coronary heart disease in Chinese Han population: a case control study.

PubMed

Zhuang, Ke; Zhang, Wencai; Zhang, Xiaobo; Wu, Fangqin; Cheng, Longxian

2011-08-01

Associations between "lipid-related" candidate genes, blood lipid concentrations and coronary artery disease (CHD) risk are not clear. We aimed to investigate the effect of three newly identified lipids loci from genome-wide association studies on CHD and blood lipid levels in Chinese Han population. The genotypes of SNPs at three newly identified lipid loci and blood lipids concentrations were examined in 1360 CHD patients and 1360 age- and sex-frequency matched controls from an unrelated Chinese Han population. Allele T of rs16996148 occurred less frequently in CHD patients with the odds ratio (OR) being 0.64 (95% CI 0.50 to 0.81), after adjusting for conventional risk factors and was associated with a 33% decreased CHD risk (P<0.01) comparing with the major allele G. Individuals with GT genotype had the lowest CHD risk. No associations were found between the polymorphisms of other two loci with CHD risk and all three SNPs had no effect on lipid profile in this population. SNP rs16996148 on chromosome 19p13 is significantly associated with lower risk for CHD in Chinese Han population. However, it remains unresolved why these lipid-related loci had significantly less effects than the correspondingly expected effects on blood lipids levels in this population.

Surface phase behavior and microstructure of lipid/PEG-emulsifier monolayer-coated microbubbles.

PubMed

Borden, Mark A; Pu, Gang; Runner, Gabriel J; Longo, Marjorie L

2004-06-01

Langmuir trough methods and fluorescence microscopy were combined to investigate the phase behavior and microstructure of monolayer shells coating micron-scale bubbles (microbubbles) typically used in biomedical applications. The monolayer shell consisted of a homologous series of saturated acyl chain phospholipids and an emulsifier containing a single hydrophobic stearate chain and polyethylene glycol (PEG) head group. PEG-emulsifier was fully miscible with expanded phase lipids and phase separated from condensed phase lipids. Phase coexistence was observed in the form of dark condensed phase lipid domains surrounded by a sea of bright, emulsifier-rich expanded phase. A rich assortment of condensed phase area fractions and domain morphologies, including networks and other novel structures, were observed in each batch of microbubbles. Network domains were reproduced in Langmuir monolayers under conditions of heating-cooling followed by compression-expansion, as well as in microbubble shells that underwent surface flow with slight compression. Domain size decreased with increased cooling rate through the phase transition temperature, and domain branching increased with lipid acyl chain length at high cooling rates. Squeeze-out of the emulsifier at a surface pressure near 35 mN/m was indicated by a plateau in Langmuir isotherms and directly visualized with fluorescence microscopy, although collapse of the solid lipid domains occurred at much higher surface pressures. Compression of the monolayer past the PEG-emulsifier squeeze-out surface pressure resulted in a dark shell composed entirely of lipid. Under certain conditions, the PEG-emulsifier was reincorporated upon subsequent expansion. Factors that affect shell formation and evolution, as well as implications for the rational design of microbubbles in medical applications, are discussed.

Obesity in mares promotes uterine inflammation and alters embryo lipid fingerprints and homeostasis.

PubMed

Sessions-Bresnahan, Dawn R; Heuberger, Adam L; Carnevale, Elaine M

2018-05-07

Maternal body composition can be an important determinant for development of obesity and metabolic syndrome in adult offspring. Obesity-related outcomes in offspring may include epigenetic alterations; however, mechanisms of fetal programming remain to be fully elucidated. This study was conducted to determine the impact of maternal obesity in the absence of a high fat diet on equine endometrium and preimplantation embryos. Embryos were collected from normal and obese mares at 8 and 16 d and a uterine biopsy at 16 d (0 d = ovulation). With the exception of 8 d embryos, each sample was divided into two pieces. One piece was analyzed for gene expression markers related to carbohydrate metabolism, lipid homeostasis, inflammation, endoplasmic reticulum stress, oxidative stress, mitochondrial stress, and components of the insulin-like growth factor (IGF) system. The second piece was analyzed for lipid content using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Obese mares had elevated concentrations of insulin, leptin and total cholesterol, and they tended to have increased triglycerides and decreased insulin sensitivity. Embryos from obese mares had altered transcript abundance in genes for inflammation and lipid homeostasis, as well as, endoplasmic reticulum, oxidative and mitochondrial stress and altered lipid fingerprints. Endometrium from obese mares had increased expression of inflammatory cytokines, lipid homeostasis regulation, mitochondrial stress, and the IGF2 system. This study demonstrates increased adiposity in mares alters the uterine environment, transcript abundance of genes for cellular functions, and lipid profiles of embryos. These alterations could affect prenatal programming, with potential long-term effects in offspring.

Shrimp Lipids: A Source of Cancer Chemopreventive Compounds

PubMed Central

López-Saiz, Carmen-María; Suárez-Jiménez, Guadalupe-Miroslava; Plascencia-Jatomea, Maribel; Burgos-Hernández, Armando

2013-01-01

Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp. PMID:24135910

Lipid-Based Nanoparticles as Pharmaceutical Drug Carriers: From Concepts to Clinic

PubMed Central

Puri, Anu; Loomis, Kristin; Smith, Brandon; Lee, Jae-Ho; Yavlovich, Amichai; Heldman, Eli; Blumenthal, Robert

2010-01-01

In recent years, various nanotechnology platforms in the area of medical biology, including both diagnostics and therapy, have gained remarkable attention. Moreover, research and development of engineered multifunctional nanoparticles as pharmaceutical drug carriers have spurred exponential growth in applications to medicine in the last decade. Design principles of these nanoparticles, including nano-emulsions, dendrimers, nano-gold, liposomes, drug-carrier conjugates, antibody-drug complexes, and magnetic nanoparticles, are primarily based on unique assemblies of synthetic, natural, or biological components, including but not limited to synthetic polymers, metal ions, oils, and lipids as their building blocks. However, the potential success of these particles in the clinic relies on consideration of important parameters such as nanoparticle fabrication strategies, their physical properties, drug loading efficiencies, drug release potential, and, most importantly, minimum toxicity of the carrier itself. Among these, lipid-based nanoparticles bear the advantage of being the least toxic for in vivo applications, and significant progress has been made in the area of DNA/RNA and drug delivery using lipid-based nanoassemblies. In this review, we will primarily focus on the recent advances and updates on lipid-based nanoparticles for their projected applications in drug delivery. We begin with a review of current activities in the field of liposomes (the so-called honorary nanoparticles), and challenging issues of targeting and triggering will be discussed in detail. We will further describe nanoparticles derived from a novel class of amphipathic lipids called bolaamphiphiles with unique lipid assembly features that have been recently examined as drug/DNA delivery vehicles. Finally, an overview of an emerging novel class of particles (based on lipid components other than phospholipids), solid lipid nanoparticles and nanostructured lipid carriers will be presented. We

Deficient serum 25-hydroxyvitamin D is associated with an atherogenic lipid profile: The Very Large Database of Lipids (VLDL-3) study.

PubMed

Lupton, Joshua R; Faridi, Kamil F; Martin, Seth S; Sharma, Sristi; Kulkarni, Krishnaji; Jones, Steven R; Michos, Erin D

2016-01-01

Cross-sectional studies have found an association between deficiencies in serum vitamin D, as measured by 25-hydroxyvitamin D (25[OH]D), and an atherogenic lipid profile. These studies have focused on a limited panel of lipid values including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Our study examines the relationship between serum 25(OH)D and an extended lipid panel (Vertical Auto Profile) while controlling for age, gender, glycemic status, and kidney function. We used the Very Large Database of Lipids, which includes US adults clinically referred for analysis of their lipid profile from 2009 to 2011. Our study focused on 20,360 subjects who had data for lipids, 25(OH)D, age, gender, hemoglobin A1c, insulin, creatinine, and blood urea nitrogen. Subjects were split into groups based on serum 25(OH)D: deficient (<20 ng/mL), intermediate (≥ 20-30 ng/mL), and optimal (≥ 30 ng/mL). The deficient group was compared to the optimal group using multivariable linear regression. In multivariable-adjusted linear regression, deficient serum 25(OH)D was associated with significantly lower serum HDL-C (-5.1%) and higher total cholesterol (+9.4%), non-HDL-C (+15.4%), directly measured LDL-C (+13.5%), intermediate-density lipoprotein cholesterol (+23.7%), very low-density lipoprotein cholesterol (+19.0%), remnant lipoprotein cholesterol (+18.4%), and TG (+26.4%) when compared with the optimal group. Deficient serum 25(OH)D is associated with significantly lower HDL-C and higher directly measured LDL-C, intermediate-density lipoprotein cholesterol, very low-density lipoproteins cholesterol, remnant lipoprotein cholesterol, and TG. Future trials examining vitamin D supplementation and cardiovascular disease risk should consider using changes in an extended lipid panel as an additional outcome measurement. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Lipid Nanoparticles Enabling Gene Therapies: From Concepts to Clinical Utility.

PubMed

Kulkarni, Jayesh A; Cullis, Pieter R; van der Meel, Roy

2018-04-23

Genetic drugs based on RNA or DNA have remarkable therapeutic potential as virtually any disease can be treated by silencing a pathological gene, expressing a beneficial protein, or by editing defective genes. However, therapies based on nucleic acid polymers require sophisticated delivery systems to deliver these macromolecules to the interior of target cells. In this study, we review progress in developing nonviral lipid nanoparticle (LNP) delivery systems that have attractive properties, including ease of manufacture, reduced immune responses, multidosing capabilities, larger payloads, and flexibility of design. LNP systems represent the most advanced delivery systems for genetic drugs as it is expected that an LNP-short interfering RNA (siRNA) formulation will receive clinical approval from the Food and Drug Administration (FDA) in 2018 for treatment of the hereditary condition transthyretin-mediated amyloidosis, a fatal condition for which there is currently no treatment. This achievement is largely due to the development of optimized ionizable cationic lipids, arguably the most important factor in the clinical success of LNP-siRNA. In addition, we highlight potential LNP applications, including targeting tissues beyond the liver and therapeutic approaches based on messenger RNA or Clustered Regularly Interspaced Short Palindromic Repeats/Cas.

V-ATPase and osmotic imbalances activate endolysosomal LC3 lipidation.

PubMed

Florey, Oliver; Gammoh, Noor; Kim, Sung Eun; Jiang, Xuejun; Overholtzer, Michael

2015-01-01

Recently a noncanonical activity of autophagy proteins has been discovered that targets lipidation of microtubule-associated protein 1 light chain 3 (LC3) onto macroendocytic vacuoles, including macropinosomes, phagosomes, and entotic vacuoles. While this pathway is distinct from canonical autophagy, the mechanism of how these nonautophagic membranes are targeted for LC3 lipidation remains unclear. Here we present evidence that this pathway requires activity of the vacuolar-type H(+)-ATPase (V-ATPase) and is induced by osmotic imbalances within endolysosomal compartments. LC3 lipidation by this mechanism is induced by treatment of cells with the lysosomotropic agent chloroquine, and through exposure to the Heliobacter pylori pore-forming toxin VacA. These data add novel mechanistic insights into the regulation of noncanonical LC3 lipidation and its associated processes, including LC3-associated phagocytosis (LAP), and demonstrate that the widely and therapeutically used drug chloroquine, which is conventionally used to inhibit autophagy flux, is an inducer of LC3 lipidation.

Modifications of Coronary Risk Factors

PubMed Central

Albu, Jeanine; Gottlieb, Sheldon H.; August, Phyllis; Nesto, Richard W.; Orchard, Trevor J.

2009-01-01

In addition to the revascularization and glycemic management interventions assigned at random, the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) design includes the uniform control of major coronary artery disease risk factors, including dyslipidemia, hypertension, smoking, central obesity, and sedentary lifestyle. Target levels for risk factors were adjusted throughout the trial to comply with changes in recommended clinical practice guidelines. At present, the goals are low-density lipoprotein cholesterol <2.59 mmol/L (<100 mg/dL) with an optional goal of <1.81 mmol/L (<70 mg/dL); plasma triglyceride level <1.70 mmol/L (<150 mg/dL); blood pressure level <130 mm Hg systolic and <80 mm Hg diastolic; and smoking cessation treatment for all active smokers. Algorithms were developed for the pharmacologic management of dyslipidemia and hypertension. Dietary prescriptions for the management of glycemia, plasma lipid profiles, and blood pressure levels were adapted from existing clinical practice guidelines. Patients with a body mass index >25 were prescribed moderate caloric restriction; after the trial was under way, a lifestyle weight-management program was instituted. All patients were formally prescribed both endurance and resistance/flexibility exercises, individually adapted to their level of disability and fitness. Pedometers were distributed as a biofeedback strategy. Strategies to achieve the goals for risk factors were designed by BARI 2D working groups (lipid, cardiovascular and hypertension, and nonpharmacologic intervention) and the ongoing implementation of the strategies is monitored by lipid, hypertension, and lifestyle intervention management centers. PMID:16813737

Factors Influencing Escherichia coli and Enterococcus durans Growth in Parenteral Nutrition With and Without Lipid Emulsion to Inform Maximum Duration of Infusion Policy Decisions.

PubMed

Austin, Peter David; Hand, Kieran Sean; Elia, Marinos

2015-11-01

Recommendations effectively restrict the infusion duration of lipid-containing parenteral nutrition (PN) from a single bag, purportedly because it encourages growth of potential microbial contaminants more than lipid-free PN. Since other variables, including osmolarity, may independently affect microbial growth, this study examined variables affecting growth of Escherichia coli and Enterococcus durans in PN infusates. Growth of E coli and E durans was assessed in quadruplicate in 12 different PN infusates, with and without lipid, in varying glucose concentrations. Results are presented as mean log10 colony-forming units (cfu)/mL ± SEM at 48 hours. The log10cfu/mL of both E coli and E durans in PN increased considerably after adjustment for baseline log10cfu/mL and pH, from 1.093 to 2.241 (P < .001) and from 0.843 to 3.451 (P < .001) respectively. Growth of each microorganism was independently increased by lipid inclusion, or increasing the proportion of nonnitrogen energy from lipid, and reduced by raising the glucose concentration or energy density. Increasing the osmolarity of lipid-PN with glucose or sodium chloride reduced growth but only significantly for sodium chloride (E coli, P = .025; E durans, P = .045). Induced changes in pH affected the growth of the 2 organisms differently. The presence of lipid and an increasing proportion of energy from lipid in PN favored the growth of E coli and E durans. Osmolarity changes and the nutrient type causing these changes independently affect the growth of these microbes. Each effect needs to be considered when establishing guidelines based on the growth of potential contaminants in different types of PN. © 2014 American Society for Parenteral and Enteral Nutrition.

Characterization of 3D Voronoi Tessellation Nearest Neighbor Lipid Shells Provides Atomistic Lipid Disruption Profile of Protein Containing Lipid Membranes

PubMed Central

Cheng, Sara Y.; Duong, Hai V.; Compton, Campbell; Vaughn, Mark W.; Nguyen, Hoa; Cheng, Kwan H.

2015-01-01

Quantifying protein-induced lipid disruptions at the atomistic level is a challenging problem in membrane biophysics. Here we propose a novel 3D Voronoi tessellation nearest-atom-neighbor shell method to classify and characterize lipid domains into discrete concentric lipid shells surrounding membrane proteins in structurally heterogeneous lipid membranes. This method needs only the coordinates of the system and is independent of force fields and simulation conditions. As a proof-of-principle, we use this multiple lipid shell method to analyze the lipid disruption profiles of three simulated membrane systems: phosphatidylcholine, phosphatidylcholine/cholesterol, and beta-amyloid/phosphatidylcholine/cholesterol. We observed different atomic volume disruption mechanisms due to cholesterol and beta-amyloid Additionally, several lipid fractional groups and lipid-interfacial water did not converge to their control values with increasing distance or shell order from the protein. This volume divergent behavior was confirmed by bilayer thickness and chain orientational order calculations. Our method can also be used to analyze high-resolution structural experimental data. PMID:25637891

Lipid droplet-associated gene expression and chromatin remodelling in LIPASE 5'-upstream region from beginning- to mid-endodormant bud in 'Fuji' apple.

PubMed

Saito, Takanori; Wang, Shanshan; Ohkawa, Katsuya; Ohara, Hitoshi; Ikeura, Hiromi; Ogawa, Yukiharu; Kondo, Satoru

2017-11-01

We found that lipid accumulation in the meristem region and the expression of MdLIP2A, which appears to be regulated by chromatin remodeling, coincided with endodormancy induction in the 'Fuji' apple. In deciduous trees, including apples (Malus × domestica Borkh.), lipid accumulation in the meristem region towards endodormancy induction has been thought to be an important process for the acquisition of cold tolerance. In this study, we conducted histological staining of crude lipids in the meristem region of 'Fuji' apples and found that lipid accumulation coincided with endodormancy induction. Since a major component of lipid bodies (triacylglycerol) is esterified fatty acids, we analysed fatty acid-derived volatile compounds and genes encoding fatty acid-modifying enzymes (MdLOX1A and MdHPL2A); the reduction of lipid breakdown also coincided with endodormancy induction. We then characterised the expression patterns of lipid body-regulatory genes MdOLE1 and MdLIP2A during endodormancy induction and found that the expression of MdLIP2A correlated well with lipid accumulation towards endodormancy induction. Based on these results, we conducted chromatin remodelling studies and localized the cis-element in the 5'-upstream region of MdLIP2A to clarify its regulatory mechanism. Finally, we revealed that chromatin was concentrated - 764 to - 862 bp of the 5'-upstream region of MdLIP2A, which harbours the GARE [gibberellin responsive MYB transcription factor binding site] and CArG [MADS-box transcription factor binding site] motifs-meristem development-related protein-binding sites.

The lipid habitats of neurotransmitter receptors in brain.

PubMed

Borroni, María Virginia; Vallés, Ana Sofía; Barrantes, Francisco J

2016-11-01

Neurotransmitter receptors, the macromolecules specialized in decoding the chemical signals encrypted in the chemical signaling mechanism in the nervous system, occur either at the somatic cell surface of chemically excitable cells or at specialized subcellular structures, the synapses. Synapses have lipid compositions distinct from the rest of the cell membrane, suggesting that neurotransmitter receptors and their scaffolding and adaptor protein partners require specific lipid habitats for optimal operation. In this review we discuss some paradigmatic cases of neurotransmitter receptor-lipid interactions, highlighting the chemical nature of the intervening lipid species and providing examples of the receptor mechanisms affected by interaction with lipids. The focus is on the effects of cholesterol, glycerophospholipids and covalent fatty acid acylation on neurotransmitter receptors. We also briefly discuss the role of lipid phase states involving lateral heterogeneities of the host membrane known to modulate membrane transport, protein sorting and signaling. Modulation of neurotransmitter receptors by lipids occurs at multiple levels, affecting a wide span of activities including their trafficking, sorting, stability, residence lifetime at the cell surface, endocytosis, and recycling, among other important functional properties at the synapse. Copyright © 2016 Elsevier B.V. All rights reserved.

Decreased inducibility of TNF expression in lipid-loaded macrophages

PubMed Central

Ares, Mikko PS; Stollenwerk, Maria; Olsson, Anneli; Kallin, Bengt; Jovinge, Stefan; Nilsson, Jan

2002-01-01

Background Inflammation and immune responses are considered to be very important in the pathogenesis of atherosclerosis. Lipid accumulation in macrophages of the arterial intima is a characteristic feature of atherosclerosis which can influence the inflammatory potential of macrophages. We studied the effects of lipid loading on the regulation of TNF expression in human monocyte-derived macrophages. Results In macrophages incubated with acetylated low density lipoprotein (ac-LDL) for 2 days, mRNA expression of TNF in cells stimulated with TNF decreased by 75%. In cell cultures stimulated over night with IL-1β, lipid loading decreased secretion of TNF into culture medium by 48%. These results suggest that lipid accumulation in macrophages makes them less responsive to inflammatory stimuli. Decreased basal activity and inducibility of transcription factor AP-1 was observed in lipid-loaded cells, suggesting a mechanism for the suppression of cytokine expression. NF-κB binding activity and inducibility were only marginally affected by ac-LDL. LDL and ac-LDL did not activate PPARγ. In contrast, oxidized LDL stimulated AP-1 and PPARγ but inhibited NF-κB, indicating that the effects of lipid loading with ac-LDL were not due to oxidation of lipids. Conclusions Accumulation of lipid, mainly cholesterol, results in down-regulation of TNF expression in macrophages. Since monocytes are known to be activated by cell adhesion, these results suggest that foam cells in atherosclerotic plaques may contribute less potently to an inflammatory reaction than newly arrived monocytes/macrophages. PMID:12366867

Genetics of Lipid and Lipoprotein Disorders and Traits.

PubMed

Dron, Jacqueline S; Hegele, Robert A

2016-01-01

Plasma lipids, namely cholesterol and triglyceride, and lipoproteins, such as low-density lipoprotein (LDL) and high-density lipoprotein, serve numerous physiological roles. Perturbed levels of these traits underlie monogenic dyslipidemias, a diverse group of multisystem disorders. We are on the verge of having a relatively complete picture of the human dyslipidemias and their components. Recent advances in genetics of plasma lipids and lipoproteins include the following: (1) expanding the range of genes causing monogenic dyslipidemias, particularly elevated LDL cholesterol; (2) appreciating the role of polygenic effects in such traits as familial hypercholesterolemia and combined hyperlipidemia; (3) accumulating a list of common variants that determine plasma lipids and lipoproteins; (4) applying exome sequencing to identify collections of rare variants determining plasma lipids and lipoproteins that via Mendelian randomization have also implicated gene products such as NPC1L1 , APOC3 , LDLR , APOA5 , and ANGPTL4 as causal for atherosclerotic cardiovascular disease; and (5) using naturally occurring genetic variation to identify new drug targets, including inhibitors of apolipoprotein (apo) C-III, apo(a), ANGPTL3, and ANGPTL4. Here, we compile this disparate range of data linking human genetic variation to plasma lipids and lipoproteins, providing a "one stop shop" for the interested reader.

[Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

PubMed

Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

2016-03-01

Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.

Microalgal lipids biochemistry and biotechnological perspectives.

PubMed

Bellou, Stamatia; Baeshen, Mohammed N; Elazzazy, Ahmed M; Aggeli, Dimitra; Sayegh, Fotoon; Aggelis, George

2014-12-01

In the last few years, there has been an intense interest in using microalgal lipids in food, chemical and pharmaceutical industries and cosmetology, while a noteworthy research has been performed focusing on all aspects of microalgal lipid production. This includes basic research on the pathways of solar energy conversion and on lipid biosynthesis and catabolism, and applied research dealing with the various biological and technical bottlenecks of the lipid production process. In here, we review the current knowledge in microalgal lipids with respect to their metabolism and various biotechnological applications, and we discuss potential future perspectives. The committing step in fatty acid biosynthesis is the carboxylation of acetyl-CoA to form malonyl-CoA that is then introduced in the fatty acid synthesis cycle leading to the formation of palmitic and stearic acids. Oleic acid may also be synthesized after stearic acid desaturation while further conversions of the fatty acids (i.e. desaturations, elongations) occur after their esterification with structural lipids of both plastids and the endoplasmic reticulum. The aliphatic chains are also used as building blocks for structuring storage acylglycerols via the Kennedy pathway. Current research, aiming to enhance lipogenesis in the microalgal cell, is focusing on over-expressing key-enzymes involved in the earlier steps of the pathway of fatty acid synthesis. A complementary plan would be the repression of lipid catabolism by down-regulating acylglycerol hydrolysis and/or β-oxidation. The tendency of oleaginous microalgae to synthesize, apart from lipids, significant amounts of other energy-rich compounds such as sugars, in processes competitive to lipogenesis, deserves attention since the lipid yield may be considerably increased by blocking competitive metabolic pathways. The majority of microalgal production occurs in outdoor cultivation and for this reason biotechnological applications face some difficulties

RaftProt: mammalian lipid raft proteome database.

PubMed

Shah, Anup; Chen, David; Boda, Akash R; Foster, Leonard J; Davis, Melissa J; Hill, Michelle M

2015-01-01

RaftProt (http://lipid-raft-database.di.uq.edu.au/) is a database of mammalian lipid raft-associated proteins as reported in high-throughput mass spectrometry studies. Lipid rafts are specialized membrane microdomains enriched in cholesterol and sphingolipids thought to act as dynamic signalling and sorting platforms. Given their fundamental roles in cellular regulation, there is a plethora of information on the size, composition and regulation of these membrane microdomains, including a large number of proteomics studies. To facilitate the mining and analysis of published lipid raft proteomics studies, we have developed a searchable database RaftProt. In addition to browsing the studies, performing basic queries by protein and gene names, searching experiments by cell, tissue and organisms; we have implemented several advanced features to facilitate data mining. To address the issue of potential bias due to biochemical preparation procedures used, we have captured the lipid raft preparation methods and implemented advanced search option for methodology and sample treatment conditions, such as cholesterol depletion. Furthermore, we have identified a list of high confidence proteins, and enabled searching only from this list of likely bona fide lipid raft proteins. Given the apparent biological importance of lipid raft and their associated proteins, this database would constitute a key resource for the scientific community. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Targeting SREBP-1-driven lipid metabolism to treat cancer

PubMed Central

Guo, Deliang; Bell, Erica Hlavin; Mischel, Paul; Chakravarti, Arnab

2014-01-01

Metabolic reprogramming is a hallmark of cancer. Oncogenic growth signaling regulates glucose, glutamine and lipid metabolism to meet the bioenergetics and biosynthetic demands of rapidly proliferating tumor cells. Emerging evidence indicates that sterol regulatory element-binding protein 1 (SREBP-1), a master transcription factor that controls lipid metabolism, is a critical link between oncogenic signaling and tumor metabolism. We recently demonstrated that SREBP-1 is required for the survival of mutant EGFR-containing glioblastoma, and that this pro-survival metabolic pathway is mediated, in part, by SREBP-1-dependent upregulation of the fatty acid synthesis and low density lipoprotein (LDL) receptor (LDLR). These results have identified EGFR/PI3K/Akt/SREBP-1 signaling pathway that promotes growth and survival in glioblastoma, and potentially other cancer types. Here, we summarize recent insights in the understanding of cancer lipid metabolism, and discuss the evidence linking SREBP-1 with PI3K/Akt signaling-controlled glycolysis and with Myc-regulated glutaminolysis to lipid metabolism. We also discuss the development of potential drugs targeting the SREBP-1-driven lipid metabolism as anti-cancer agents. PMID:23859617

Receptor-Mediated Uptake and Intracellular Sorting of Multivalent Lipid Nanoparticles Against the Epidermal Growth Factor Receptor (EGFR) and the Human EGFR 2 (HER2)

NASA Astrophysics Data System (ADS)

Tran, David Tu

In the area of receptor-targeted lipid nanoparticles for drug delivery, efficiency has been mainly focused on cell-specificity, endocytosis, and subsequently effects on bioactivity such as cell growth inhibition. Aspects of targeted liposomal uptake and intracellular sorting are not well defined. This dissertation assessed a series of ligands as targeted functional groups against HER2 and EGFR for liposomal drug delivery. Receptor-mediated uptake, both mono-targeted and dual-targeted to multiple receptors of different ligand valence, and the intracellular sorting of lipid nanoparticles were investigated to improve the delivery of drugs to cancer cells. Lipid nanoparticles were functionalized through a new sequential micelle transfer---conjugation method, while the micelle transfer method was extended to growth factors. Through a combination of both techniques, anti-HER2 and anti-EGFR dual-targeted immunoliposomes with different combinations of ligand valence were developed for comparative studies. With the array of lipid nanoparticles, the uptake and cytotoxicity of lipid nanoparticles in relationship to ligand valence, both mono-targeting and dual-targeting, were evaluated on a small panel of breast cancer cell lines that express HER2 and EGFR of varying levels. Comparable uptake ratios of ligand to expressed receptor and apparent cooperativity were observed. For cell lines that express both receptors, additive dose-uptake effects were also observed with dual-targeted immunoliposomes, which translated to marginal improvements in cell growth inhibition with doxorubicin delivery. Colocalization analysis revealed that ligand-conjugated lipid nanoparticles settle to endosomal compartments similar to their attached ligands. Pathway transregulation and pathway saturation were also observed to affect trafficking. In the end, liposomes routed to the recycling endosomes were never observed to traffic beyond the endosomes nor to be exocytose like recycled ligands. Based on

Influence of lipids on the interfacial disposition of respiratory syncytical virus matrix protein.

PubMed

McPhee, Helen K; Carlisle, Jennifer L; Beeby, Andrew; Money, Victoria A; Watson, Scott M D; Yeo, R Paul; Sanderson, John M

2011-01-04

The propensity of a matrix protein from an enveloped virus of the Mononegavirales family to associate with lipids representative of the viral envelope has been determined using label-free methods, including tensiometry and Brewster angle microscopy on lipid films at the air-water interface and atomic force microscopy on monolayers transferred to OTS-treated silicon wafers. This has enabled factors that influence the disposition of the protein with respect to the lipid interface to be characterized. In the absence of sphingomyelin, respiratory syncytial virus matrix protein penetrates monolayers composed of mixtures of phosphocholines with phosphoethanolamines or cholesterol at the air-water interface. In ternary mixtures composed of sphingomyelin, 1,2-dioleoyl-sn-glycero-3-phosphocholine, and cholesterol, the protein exhibits two separate behaviors: (1) peripheral association with the surface of sphingomyelin-rich domains and (2) penetration of sphingomyelin-poor domains. Prolonged incubation of the protein with mixtures of phosphocholines and phosphoethanolamines leads to the formation of helical protein assemblies of uniform diameter that demonstrate an inherent propensity of the protein to assemble into a filamentous form.

Lipid-converter, a framework for lipid manipulations in molecular dynamics simulations

PubMed Central

Larsson, Per; Kasson, Peter M.

2014-01-01

Construction of lipid membrane and membrane protein systems for molecular dynamics simulations can be a challenging process. In addition, there are few available tools to extend existing studies by repeating simulations using other force fields and lipid compositions. To facilitate this, we introduce lipidconverter, a modular Python framework for exchanging force fields and lipid composition in coordinate files obtained from simulations. Force fields and lipids are specified by simple text files, making it easy to introduce support for additional force fields and lipids. The converter produces simulation input files that can be used for structural relaxation of the new membranes. PMID:25081234

Lipid antigens in immunity

PubMed Central

Dowds, C. Marie; Kornell, Sabin-Christin

2014-01-01

Lipids are not only a central part of human metabolism but also play diverse and critical roles in the immune system. As such, they can act as ligands of lipid-activated nuclear receptors, control inflammatory signaling through bioactive lipids such as prostaglandins, leukotrienes, lipoxins, resolvins, and protectins, and modulate immunity as intracellular phospholipid- or sphingolipid-derived signaling mediators. In addition, lipids can serve as antigens and regulate immunity through the activation of lipid-reactive T cells, which is the topic of this review. We will provide an overview of the mechanisms of lipid antigen presentation, the biology of lipid-reactive T cells, and their contribution to immunity. PMID:23999493

Lipids and buoyancy in Southern ocean pteropods.

PubMed

Phleger, C F; Nichols, P D; Virtue, P

1997-10-01

The lipids of Clione limacina, a Southern Ocean pteropod (order Gymnosomata), contain 28% diacylglyceryl ether (DAGE) (as percentage of total lipid) whereas the pteropod Limacina helicina (order Thecosomata) lacks DAGE. The alkyl glyceryl ether diols (1-O-alkyl glycerols, GE) of Clione DAGE are dominated by 16:0 (60%) and 15:0 (21%), in contrast with deep-sea shark liver DAGE, which is dominated by 18:1 GE. The fatty acid profiles of Clione and Limacina are similar (28-32% polyunsaturated, 26-34% monounsaturated) as are the sterols, which include 24-methylenecholesterol, transdehydrocholesterol, cholesterol, and desmosterol. This finding probably reflects the fact that Limacina is the major food source for Clione. Spongiobranchaea australis, another Southern Ocean pteropod (order Gymnosomata), has 0.9-1.7% DAGE, but has less lipid (3.3-4.8 mg/g lipid, wet weight) than Clione (50.8 mg/g lipid, wet weight). We propose a buoyancy role for DAGE in Clione since Limacina has bubbles for flotation which Clione lack; DAGE provides 23% more uplift than triacylglycerol at a concentration of 1.025 g/mL seawater.

A Molecular Probe for the Detection of Polar Lipids in Live Cells

PubMed Central

Bader, Christie A.; Shandala, Tetyana; Carter, Elizabeth A.; Ivask, Angela; Guinan, Taryn; Hickey, Shane M.; Werrett, Melissa V.; Wright, Phillip J.; Simpson, Peter V.; Stagni, Stefano; Voelcker, Nicolas H.; Lay, Peter A.; Massi, Massimiliano; Brooks, Douglas A.

2016-01-01

Lipids have an important role in many aspects of cell biology, including membrane architecture/compartment formation, intracellular traffic, signalling, hormone regulation, inflammation, energy storage and metabolism. Lipid biology is therefore integrally involved in major human diseases, including metabolic disorders, neurodegenerative diseases, obesity, heart disease, immune disorders and cancers, which commonly display altered lipid transport and metabolism. However, the investigation of these important cellular processes has been limited by the availability of specific tools to visualise lipids in live cells. Here we describe the potential for ReZolve-L1™ to localise to intracellular compartments containing polar lipids, such as for example sphingomyelin and phosphatidylethanolamine. In live Drosophila fat body tissue from third instar larvae, ReZolve-L1™ interacted mainly with lipid droplets, including the core region of these organelles. The presence of polar lipids in the core of these lipid droplets was confirmed by Raman mapping and while this was consistent with the distribution of ReZolve-L1™ it did not exclude that the molecular probe might be detecting other lipid species. In response to complete starvation conditions, ReZolve-L1™ was detected mainly in Atg8-GFP autophagic compartments, and showed reduced staining in the lipid droplets of fat body cells. The induction of autophagy by Tor inhibition also increased ReZolve-L1™ detection in autophagic compartments, whereas Atg9 knock down impaired autophagosome formation and altered the distribution of ReZolve-L1™. Finally, during Drosophila metamorphosis fat body tissues showed increased ReZolve-L1™ staining in autophagic compartments at two hours post puparium formation, when compared to earlier developmental time points. We concluded that ReZolve-L1™ is a new live cell imaging tool, which can be used as an imaging reagent for the detection of polar lipids in different intracellular

Supercritical fluid chromatography for lipid analysis in foodstuffs.

PubMed

Donato, Paola; Inferrera, Veronica; Sciarrone, Danilo; Mondello, Luigi

2017-01-01

The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO 2 , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biogenesis of the multifunctional lipid droplet: Lipids, proteins, and sites

PubMed Central

Gross, Steven P.

2014-01-01

Lipid droplets (LDs) are ubiquitous dynamic organelles that store and supply lipids in all eukaryotic and some prokaryotic cells for energy metabolism, membrane synthesis, and production of essential lipid-derived molecules. Interest in the organelle’s cell biology has exponentially increased over the last decade due to the link between LDs and prevalent human diseases and the discovery of new and unexpected functions of LDs. As a result, there has been significant recent progress toward understanding where and how LDs are formed, and the specific lipid pathways that coordinate LD biogenesis. PMID:24590170

Impact of lipid disorders on mortality among Saudi patients with heart failure

PubMed Central

Al Qahtani, M.; Al Backer, T.; Al Anazi, T.; Al Johani, N.; Binsalih, S.; AlGobain, M.; Alshammari, H.

2014-01-01

Background Dyslipidemia, a known cardiovascular risk factor, is extremely common among Saudis, both adults and children. The impact, however, of dyslipidemia and several other lipid disorders in patients with congestive heart failure in this particular population has not been documented. This study aims to fill the gap. Methods This retrospective, single center study was conducted at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Of the 500 cases seen during the period between 2002 and 2008, 392 were included in the study. Charts were reviewed and information on medical history, medications, and lipid status were documented. Results Low HDL-cholesterol level was the most common lipid disorder with 82.9%, followed by hypertriglyceridemia (35.2%), atherogenic dyslipidemia (27.8%), and hypercholesterolemia (9.2%). Diabetes mellitus was the single most significant predictor of mortality (p = 0.001). Among the lipid disorders, only low levels of HDL-cholesterol contributed to significant mortality risk [OR 1.29 (Confidence Interval 1.04–1.59) (p-value < 0.01)] adjusted for age, gender and statin use. Conclusion The results of this study suggest that emphasis should be on the elevation of HDL-cholesterol levels among subjects with congestive heart failure, without compromising any ongoing management of LDL-lowering drugs. Management should not be limited to conventional statin use and should promote other treatments to elevate HDL-cholesterol levels. PMID:25870502

Oxidation-Induced Increase In Photoreactivity of Bovine Retinal Lipid Extract.

PubMed

Koscielniak, A; Serafin, M; Duda, M; Oles, T; Zadlo, A; Broniec, A; Berdeaux, O; Gregoire, S; Bretillon, L; Sarna, T; Pawlak, A

2017-12-01

The mammalian retina contains a high level of polyunsaturated fatty acids, including docosahexaenoic acid (22:6) (DHA), which are highly susceptible to oxidation. It has been shown that one of the products of DHA oxidation-carboxyethylpyrrole (CEP), generated in situ, causes modifications of retinal proteins and induces inflammation response in the outer retina. These contributing factors may play a role in the development of age-related macular degeneration (AMD). It is also possible that some of the lipid oxidation products are photoreactive, and upon irradiation with blue light may generate reactive oxygen species. Therefore, in this work we analysed oxidation-induced changes in photoreactivity of lipids extracted from bovine neural retinas. Lipid composition of bovine neural retinas closely resembles that of human retinas making the bovine tissue a convenient model for studying the photoreactivity and potential phototoxicity of oxidized human retinal lipids. Lipid composition of bovine neural retinas Folch' extracts (BRex) was determined by gas chromatography (GC) and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS) analysis. Liposomes prepared from BRex, equilibrated with air, were oxidized in the dark at 37 °C for up to 400 h. The photoreactivity of BRex at different stages of oxidation was studied by EPR-oximetry and EPR-spin trapping. Photogeneration of singlet oxygen ( 1 O 2 , 1 Δ g ) by BRex was measured using time-resolved detection of the characteristic phosphorescence at 1270 nm. To establish contribution of lipid components to the analysed photoreactivity of Folch' extract of bovine retinas, a mixture of selected synthetic lipids in percent by weight (w/w %) ratio resembling that of the BRex has been also studied. Folch's extraction of bovine neural retinas was very susceptible to oxidation despite the presence of powerful endogenous antioxidants such as α-tocopherol and zeaxanthin. Non

Essential oil-loaded lipid nanoparticles for wound healing.

PubMed

Saporito, Francesca; Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Boselli, Cinzia; Icaro Cornaglia, Antonia; Mannucci, Barbara; Grisoli, Pietro; Vigani, Barbara; Ferrari, Franca

2018-01-01

Chronic wounds and severe burns are diseases responsible for severe morbidity and even death. Wound repair is a crucial process and tissue regeneration enhancement and infection prevention are key factors to minimize pain, discomfort, and scar formation. The aim of this work was the development of lipid nanoparticles (solid lipid nanoparticles and nanostructured lipid carriers [NLC]), to be loaded with eucalyptus or rosemary essential oils and to be used, as medical devices, to enhance healing of skin wounds. Lipid nanoparticles were based on natural lipids: cocoa butter, as solid lipid, and olive oil or sesame oil, as liquid lipids. Lecithin was chosen as surfactant to stabilize nanoparticles and to prevent their aggregation. The systems were prepared by high shear homogenization followed by ultrasound application. Nanoparticles were characterized for physical-chemical properties, bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward normal human dermal fibroblasts. Antimicrobial activity of nanoparticles was evaluated against two reference microbial strains, one of Staphylococcus aureus , the other of Streptococcus pyogenes . Finally, the capability of nanoparticles to promote wound healing in vivo was evaluated on a rat burn model. NLC based on olive oil and loaded with eucalyptus oil showed appropriate physical-chemical properties, good bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward fibroblasts, associated to antimicrobial properties. Moreover, the in vivo results evidenced the capability of these NLC to enhance the healing process. Olive oil, which is characterized by a high content of oleic acid, proved to exert a synergic effect with eucalyptus oil with respect to antimicrobial activity and wound repair promotion.

Obesity and Breast Cancer: Current Insights on the Role of Fatty Acids and Lipid Metabolism in Promoting Breast Cancer Growth and Progression

PubMed Central

Blücher, Christina; Stadler, Sonja C.

2017-01-01

Obesity and excess accumulation of adipose tissue are known risk factors for several types of cancer, including breast cancer. With the incidence of obesity constantly rising worldwide, understanding the molecular details of the interaction between adipose tissue and breast tumors, the most common tumors in women, becomes an urgent task. In terms of lipid metabolism, most of the studies conducted so far focused on upregulated de novo lipid synthesis in cancer cells. More recently, the use of extracellular lipids as source of energy came into focus. Especially in obesity, associated dysfunctional adipose tissue releases increased amounts of fatty acids, but also dietary lipids can be involved in promoting tumor growth and progression. In addition, it was shown that breast cancer cells and adipocytes, which are a major component of the stroma of breast tumors, are able to directly interact with each other. Breast cancer cells and adjacent adipocytes exchange molecules such as growth factors, chemokines, and interleukins in a reciprocal manner. Moreover, it was shown that breast cancer cells can access and utilize fatty acids produced by neighboring adipocytes. Thus adipocytes, and especially hypertrophic adipocytes, can act as providers of lipids, which can be used as a source of energy for fatty acid oxidation and as building blocks for tumor cell growth. PMID:29163362

Single lipid bilayer deposition on polymer surfaces using bicelles.

PubMed

Saleem, Qasim; Zhang, Zhenfu; Petretic, Amy; Gradinaru, Claudiu C; Macdonald, Peter M

2015-03-09

A lipid bilayer was deposited on a 3 μm diameter polystyrene (PS) bead via hydrophobic anchoring of bicelles containing oxyamine-bearing cholesteric moieties reacting with the aldehyde functionalized bead surface. Discoidal bicelles were formed by mixing dimyristoylphosphatidylcholine (DMPC), dihexanoylphosphatidylcholine (DHPC), dimyristoyltrimethylammonium propane (DMTAP), and the oxyamine-terminated cholesterol derivative, cholest-5-en-3β-oxy-oct-3,6-oxa-an-8-oxyamine (CHOLOA), in the molar ratio DMPC/DHCP/DMTAP/CHOLOA (1/0.5/0.01/0.05) in water. Upon exposure to aldehyde-bearing PS beads, a stable single lipid bilayer coating rapidly formed at the bead surface. Fluorescence recovery after photobleaching demonstrated that the deposited lipids fused into an encapsulating lipid bilayer. Electrospray ionization mass spectrometry showed that the short chain lipid DHPC was entirely absent from the PS adherent lipid coating. Fluorescence quenching measurements proved that the coating was a single lipid bilayer. The bicelle coating method is thus simple and robust, can be modified to include membrane-associated species, and can be adapted to coat any number of different surfaces.

Development, characterization, and evaluation of sunscreen cream containing solid lipid nanoparticles of silymarin.

PubMed

Netto MPharm, Gladyston; Jose, Jobin

2017-12-10

Most of the sunscreen formulations mainly contain chemicals or synthetic molecules. Nowadays, researchers are mainly focussing on herbal formulations due to toxicity of the synthetic molecules. Silymarin is a natural flavonoids having excellent antioxidant properties. Solid lipid nanoparticles are novel drug carriers which improve the drug stability and tolerance effect and also enhance the permeation effect. This study aimed at the preparation of solid lipid nanoparticles containing silymarin that will be incorporated into a sunscreen cream and determine its sun protection factor. The solid lipid nanoparticles were prepared by micro-emulsion method; here, the glyceryl monostearate was used as lipid, and Tween 80 was used as an emulsifier. The solid lipid nanoparticles were evaluated for drug entrapment, particle size and morphology, zeta potential, and polydispersity index. The dispersion was formulated into sunscreen cream and evaluated for various parameters, such as extrudability, viscosity, spreadability, drug content, in vitro drug release, ex vivo permeation of drug, in vitro and in vivo sun protection factor determination, in vivo skin irritation test, and accelerated stability studies. The results suggested that as the concentration of emulsifier increased, the entrapment efficiency of silymarin increased. In vitro and in vivo sun protection factor determination showed that SPF of 13.80 and 14.1, respectively. Stability studies were performed under accelerated conditions, and it did not show any appreciable change in parameters. These results indicated that the sunscreen containing silymarin solid lipid nanoparticles exhibited better photoprotective action. © 2017 Wiley Periodicals, Inc.

Factors that contribute to biomarker responses in humans including a study in individuals taking Vitamin C supplementation.

PubMed

Anderson, D

2001-09-01

It is possible in many situations to identify humans exposed to potentially toxic materials in the workplace and in the environment. As in most human studies, there tends to be a high degree of interindividual variability in response to chemical insults. Some non-exposed control individuals exhibit as high a level of damage as some exposed individuals and some of these have levels of damage as low as many of the controls. Thus, it is only the mean values of the groups that can substantiate an exposure-related problem; the data on an individual basis are still of limited use. While human lymphocytes remain the most popular cell type for monitoring purposes, sperm, buccal, nasal, epithelial and placental cells are also used. However, for interpretation of responses, the issue of confounding factors must be addressed. There are endogenous confounding factors, such as age, gender, and genetic make-up and exogenous ones, including lifestyle habits (smoking, drinking, etc.) There are biomarkers of exposure, effect/response and susceptibility and the last may be influenced by the genotype and polymorphism genes existing in a population. From our own studies, confounding effects on cytogenetic damage and ras oncoproteins will be considered in relation to workers exposed to vinyl chloride and petroleum emissions and to volunteers taking Vitamin C supplementation. Smoking history, exposure and duration of employment affected the worker studies. For petroleum emissions, so did gender and season of exposure. For the non-smoking volunteer Vitamin C supplementation study, cholesterol levels, plasma Vitamin C levels, lipid peroxidation products and DNA damage in the Comet assay were also measured. Gender affected differences in Vitamin C levels, antioxidant capacity and the number of chromosome aberrations induced by bleomycin challenge in vitro. The results were the same for both high and low cholesterol subjects. The relationship between biomarkers and the various factors which

Exome-wide association analysis reveals novel coding sequence variants associated with lipid traits in Chinese.

PubMed

Tang, Clara S; Zhang, He; Cheung, Chloe Y Y; Xu, Ming; Ho, Jenny C Y; Zhou, Wei; Cherny, Stacey S; Zhang, Yan; Holmen, Oddgeir; Au, Ka-Wing; Yu, Haiyi; Xu, Lin; Jia, Jia; Porsch, Robert M; Sun, Lijie; Xu, Weixian; Zheng, Huiping; Wong, Lai-Yung; Mu, Yiming; Dou, Jingtao; Fong, Carol H Y; Wang, Shuyu; Hong, Xueyu; Dong, Liguang; Liao, Yanhua; Wang, Jiansong; Lam, Levina S M; Su, Xi; Yan, Hua; Yang, Min-Lee; Chen, Jin; Siu, Chung-Wah; Xie, Gaoqiang; Woo, Yu-Cho; Wu, Yangfeng; Tan, Kathryn C B; Hveem, Kristian; Cheung, Bernard M Y; Zöllner, Sebastian; Xu, Aimin; Eugene Chen, Y; Jiang, Chao Qiang; Zhang, Youyi; Lam, Tai-Hing; Ganesh, Santhi K; Huo, Yong; Sham, Pak C; Lam, Karen S L; Willer, Cristen J; Tse, Hung-Fat; Gao, Wei

2015-12-22

Blood lipids are important risk factors for coronary artery disease (CAD). Here we perform an exome-wide association study by genotyping 12,685 Chinese, using a custom Illumina HumanExome BeadChip, to identify additional loci influencing lipid levels. Single-variant association analysis on 65,671 single nucleotide polymorphisms reveals 19 loci associated with lipids at exome-wide significance (P<2.69 × 10(-7)), including three Asian-specific coding variants in known genes (CETP p.Asp459Gly, PCSK9 p.Arg93Cys and LDLR p.Arg257Trp). Furthermore, missense variants at two novel loci-PNPLA3 p.Ile148Met and PKD1L3 p.Thr429Ser-also influence levels of triglycerides and low-density lipoprotein cholesterol, respectively. Another novel gene, TEAD2, is found to be associated with high-density lipoprotein cholesterol through gene-based association analysis. Most of these newly identified coding variants show suggestive association (P<0.05) with CAD. These findings demonstrate that exome-wide genotyping on samples of non-European ancestry can identify additional population-specific possible causal variants, shedding light on novel lipid biology and CAD.

Deficiency in Nrf2 transcription factor decreases adipose tissue mass and hepatic lipid accumulation in leptin-deficient mice.

PubMed

Xu, Jialin; Donepudi, Ajay C; More, Vijay R; Kulkarni, Supriya R; Li, Liya; Guo, Liangran; Yan, Bingfang; Chatterjee, Tapan; Weintraub, Neal; Slitt, Angela L

2015-02-01

To evaluate whether Nrf2 deficiency impacts insulin resistance and lipid accumulation in liver and white adipose tissue. Lep(ob/ob) mice (OB) with targeted Nrf2 deletion (OB-Nrf2KO) were generated. Pathogenesis of obesity and type 2 diabetes was measured in C57BL/6J, Nrf2KO, OB, and OB-Nrf2KO mice. Hepatic lipid content, lipid clearance, and very low-density lipoprotein (VLDL) secretion were determined between OB and OB-Nrf2KO mice. OB-Nrf2KO mice exhibited decreased white adipose tissue mass and decreased adipogenic and lipogenic gene expression compared with OB mice. Nrf2 deficiency prolonged hyperglycemia in response to glucose challenge, which was paralleled by reduced insulin-stimulated Akt phosphorylation. In OB mice, Nrf2 deficiency decreased hepatic lipid accumulation, decreased peroxisome proliferator-activated receptor γ expression and nicotinamide adenine dinucleotide phosphate (NADPH) content, and enhanced VLDL secretion. However, this observation was opposite in lean mice. Additionally, OB-Nrf2KO mice exhibited increased plasma triglyceride content, decreased HDL-cholesterol content, and enhanced apolipoprotein B expression, suggesting Nrf2 deficiency caused dyslipidemia in these mice. Nrf2 deficiency in Lep(ob/ob) mice reduced white adipose tissue mass and prevented hepatic lipid accumulation but induced insulin resistance and dyslipidemia. This study indicates a dual role of Nrf2 during metabolic dysregulation-increasing lipid accumulation in liver and white adipose tissue but preventing lipid accumulation in obese mice. © 2014 The Obesity Society.

Effect of Lipid-Based Nanostructure on Protein Encapsulation within the Membrane Bilayer Mimetic Lipidic Cubic Phase Using Transmembrane and Lipo-proteins from the Beta-Barrel Assembly Machinery.

PubMed

van 't Hag, Leonie; Shen, Hsin-Hui; Lin, Tsung-Wu; Gras, Sally L; Drummond, Calum J; Conn, Charlotte E

2016-11-29

A fundamental understanding of the effect of amphiphilic protein encapsulation on the nanostructure of the bicontinuous cubic phase is crucial to progressing biomedical and biological applications of these hybrid protein-lipid materials, including as drug delivery vehicles, as biosensors, biofuel cells and for in meso crystallization. The relationship between the lipid nanomaterial and the encapsulated protein, however, remains poorly understood. In this study, we investigated the effect of incorporating the five transmembrane and lipo-proteins which make up the β-barrel assembly machinery from Gram-negative bacteria within a series of bicontinuous cubic phases. The transmembrane β-barrel BamA caused an increase in lattice parameter of the cubic phase upon encapsulation. By contrast, the mainly hydrophilic lipo-proteins BamB-E caused the cubic phase lattice parameters to decrease, despite their large size relative to the diameter of the cubic phase water channels. Analysis of the primary amino acid sequence was used to rationalize this effect, based on specific interactions between aromatic amino acids within the proteins and the polar-apolar interface. Other factors that were found to have an effect were lateral bilayer pressure and rigidity within the lipid bilayer, water channel diameter, and size and structure of the lipo-proteins. The data presented suggest that hydrophilic bioactive molecules can be selectively encapsulated within the cubic phase by using a lipid anchor or aromatic amino acids, for drug delivery or biosensing applications.

Multifunctional pH-Sensitive Amino Lipids for siRNA Delivery.

PubMed

Gujrati, Maneesh; Vaidya, Amita; Lu, Zheng-Rong

2016-01-20

RNA interference (RNAi) represents a powerful modality for human disease therapy that can regulate gene expression signature using small interfering RNA (siRNA). Successful delivery of siRNA into the cytoplasm of target cells is imperative for efficient RNAi and also constitutes the primary stumbling block in the clinical applicability of RNAi. Significant progress has been made in the development of lipid-based siRNA delivery systems, which have practical advantages like simple chemistry and easy formulation of nanoparticles with siRNA. This review discusses the recent development of pH-sensitive amino lipids, with particular focus on multifunctional pH-sensitive amino lipids for siRNA delivery. The key components of these multifunctional lipids include a protonatable amino head group, distal lipid tails, and two cross-linkable thiol groups, which together facilitate the facile formation of stable siRNA-nanoparticles, easy surface modification for target-specific delivery, endosomal escape in response to the pH decrease during subcellular trafficking, and reductive dissociation of the siRNA-nanoparticles for cytoplasmic release of free siRNA. By virtue of these properties, multifunctional pH-sensitive lipids can mediate efficient cytosolic siRNA delivery and gene silencing. Targeted siRNA nanoparticles can be readily formulated with these lipids, without the need for other helper lipids, to promote systemic delivery of therapeutic siRNAs. Such targeted siRNA nanoparticles have been shown to effectively regulate the expression of cancer-related genes, resulting in significant efficacy in the treatment of aggressive tumors, including metastatic triple negative breast cancer. These multifunctional pH-sensitive lipids constitute a promising platform for the systemic and targeted delivery of therapeutic siRNA for the treatment of human diseases. This review summarizes the structure-property relationship of the multifunctional pH-sensitive lipids and their efficacy in

PPAR-α, a lipid-sensing transcription factor, regulates blood–brain barrier efflux transporter expression

PubMed Central

More, Vijay R; Campos, Christopher R; Evans, Rebecca A; Oliver, Keith D; Chan, Gary NY; Miller, David S

2016-01-01

Lipid sensor peroxisome proliferator-activated receptor alpha (PPAR-α) is the master regulator of lipid metabolism. Dietary release of endogenous free fatty acids, fibrates, and certain persistent environmental pollutants, e.g. perfluoroalkyl fire-fighting foam components, are peroxisome proliferator-activated receptor alpha ligands. Here, we define a role for peroxisome proliferator-activated receptor alpha in regulating the expression of three ATP-driven drug efflux transporters at the rat and mouse blood–brain barriers: P-glycoprotein (Abcb1), breast cancer resistance protein (Bcrp/Abcg2), and multidrug resistance-associated protein 2 (Mrp2/Abcc2). Exposing isolated rat brain capillaries to linoleic acid, clofibrate, or PKAs increased the transport activity and protein expression of the three ABC transporters. These effects were blocked by the PPAR-α antagonist, GW6471. Dosing rats with 20 mg/kg or 200 mg/kg of clofibrate decreased the brain accumulation of the P-glycoprotein substrate, verapamil, by 50% (in situ brain perfusion; effects blocked by GW6471) and increased P-glycoprotein expression and activity in capillaries ex vivo. Fasting C57Bl/6 wild-type mice for 24 h increased both serum lipids and brain capillary P-glycoprotein transport activity. Fasting did not alter P-glycoprotein activity in PPAR-α knockout mice. These results indicate that hyperlipidemia, lipid-lowering fibrates and exposure to certain fire-fighting foam components activate blood–brain barrier peroxisome proliferator-activated receptor alpha, increase drug efflux transporter expression and reduce drug delivery to the brain. PMID:27193034

The Membrane and Lipids as Integral Participants in Signal Transduction: Lipid Signal Transduction for the Non-Lipid Biochemist

ERIC Educational Resources Information Center

Eyster, Kathleen M.

2007-01-01

Reviews of signal transduction have often focused on the cascades of protein kinases and protein phosphatases and their cytoplasmic substrates that become activated in response to extracellular signals. Lipids, lipid kinases, and lipid phosphatases have not received the same amount of attention as proteins in studies of signal transduction.…

Lipids, lysosomes, and autophagy

PubMed Central

2016-01-01

Lipids are essential components of a cell providing energy substrates for cellular processes, signaling intermediates, and building blocks for biological membranes. Lipids are constantly recycled and redistributed within a cell. Lysosomes play an important role in this recycling process that involves the recruitment of lipids to lysosomes via autophagy or endocytosis for their degradation by lysosomal hydrolases. The catabolites produced are redistributed to various cellular compartments to support basic cellular function. Several studies demonstrated a bidirectional relationship between lipids and lysosomes that regulate autophagy. While lysosomal degradation pathways regulate cellular lipid metabolism, lipids also regulate lysosome function and autophagy. In this review, we focus on this bidirectional relationship in the context of dietary lipids and provide an overview of recent evidence of how lipid-overload lipotoxicity, as observed in obesity and metabolic syndrome, impairs lysosomal function and autophagy that may eventually lead to cellular dysfunction or cell death. PMID:27330054

MicroRNA modulation of lipid metabolism and oxidative stress in cardiometabolic diseases.

PubMed

Aranda, Juan F; Madrigal-Matute, Julio; Rotllan, Noemi; Fernández-Hernando, Carlos

2013-09-01

The regulation of the metabolism of cholesterol has been one of the most studied biological processes since its first isolation from gallstones in 1784. High levels of plasma low-density lipoprotein (LDL) cholesterol and reduced levels of plasma high-density lipoprotein (HDL) cholesterol are widely recognized as major risk factors of cardiovascular disease. An imbalance in the production of reactive oxygen species can oxidize LDL particles, increasing the levels of the highly proatherogenic oxidized LDL. Furthermore, under pathological scenarios, numerous molecules can function as pro-oxidants, such as iron or (high levels of) glucose. In addition to the classical mechanisms regulating lipid homeostasis, recent studies have demonstrated the important role of microRNAs (miRNAs) as regulators of lipoprotein metabolism, oxidative derivatives of lipoprotein, and redox balance. Here, we summarize recent findings in the field, highlighting the contributions of some miRNAs to lipid- and oxidative-associated pathologies. We also discuss how therapeutic intervention of miRNAs may be a promising strategy to decrease LDL, increase HDL, and ameliorate lipid- and oxidative-related disorders, including atherosclerosis, nonalcoholic fatty liver disease, and metabolic syndrome. © 2013 Elsevier Inc. All rights reserved.

Cationic niosomes an effective gene carrier composed of novel spermine-derivative cationic lipids: effect of central core structures.

PubMed

Opanasopit, Praneet; Leksantikul, Lalita; Niyomtham, Nattisa; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Yingyongnarongkul, Boon-Ek

2017-05-01

Cationic niosomes formulated from Span 20, cholesterol (Chol) and novel spermine-based cationic lipids of multiple central core structures (di(oxyethyl)amino, di(oxyethyl)amino carboxy, 3-amino-1,2-dioxypropyl and 2-amino-1,3-dioxypropyl) were successfully prepared for improving transfection efficiency in vitro. The niosomes composed of spermine cationic lipid with central core structure of di(oxyethyl)amino revealed the highest gene transfection efficiency. To investigate the factors affecting gene transfection and cell viability including differences in the central core structures of cationic lipids, the composition of vesicles, molar ratio of cationic lipids in formulations and the weight ratio of niosomes to DNA. Cationic niosomes composed of nonionic surfactants (Span20), cholesterol and spermine-based cationic lipids of multiple central core structures were formulated. Gene transfection and cell viability were evaluated on a human cervical carcinoma cell line (HeLa cells) using pDNA encoding green fluorescent protein (pEGFP-C2). The morphology, size and charge were also characterized. High transfection efficiency was obtained from cationic niosomes composed of Span20:Chol:cationic lipid at the molar ratio of 2.5:2.5:0.5 mM. Cationic lipids with di(oxyethyl)amino as a central core structure exhibited highest transfection efficiency. In addition, there was also no serum effect on transfection efficiency. These novel cationic niosomes may constitute a good alternative carrier for gene transfection.

Freeze-dried strawberry powder improves lipid profile and lipid peroxidation in women with metabolic syndrome: baseline and post intervention effects

PubMed Central

Basu, Arpita; Wilkinson, Marci; Penugonda, Kavitha; Simmons, Brandi; Betts, Nancy M; Lyons, Timothy J

2009-01-01

Background Strawberry flavonoids are potent antioxidants and anti-inflammatory agents that have been shown to reduce cardiovascular disease risk factors in prospective cohort studies. Effects of strawberry supplementation on metabolic risk factors have not been studied in obese populations. We tested the hypothesis that freeze-dried strawberry powder (FSP) will lower fasting lipids and biomarkers of oxidative stress and inflammation at four weeks compared to baseline. We also tested the tolerability and safety of FSP in subjects with metabolic syndrome. FSP is a concentrated source of polyphenolic flavonoids, fiber and phytosterols. Methods Females (n = 16) with 3 features of metabolic syndrome (waist circumference >35 inches, triglycerides > 150 mg/dL, fasting glucose > 100 mg/dL and < 126 mg/dL, HDL <50 mg/dL, or blood pressure >130/85 mm Hg) were enrolled in the study. Subjects consumed two cups of the strawberry drink daily for four weeks. Each cup had 25 g FSP blended in water. Fasting blood draws, anthropometrics, dietary analyses, and blood pressure measurements were done at baseline and 4 weeks. Biomarkers of oxidative stress and inflammation were measured using ELISA techniques. Plasma ellagic acid was measured using HPLC-UV techniques. Results Total cholesterol and LDL-cholesterol levels were significantly lower at 4 weeks versus baseline (-5% and -6%, respectively, p < 0.05), as was lipid peroxidation in the form of malondialdehyde and hydroxynonenal (-14%, p < 0.01). Oxidized-LDL showed a decreasing trend at 4 weeks (p = 0.123). No effects were noted on markers of inflammation including C-reactive protein and adiponectin. A significant number of subjects (13/16) showed an increase in plasma ellagic acid at four weeks versus baseline, while no significant differences were noted in dietary intakes at four weeks versus baseline. Thus, short-term supplementation of freeze-dried strawberries appeared to exert hypocholesterolemic effects and decrease lipid

Binary lipids-based nanostructured lipid carriers for improved oral bioavailability of silymarin.

PubMed

Shangguan, Mingzhu; Lu, Yi; Qi, Jianping; Han, Jin; Tian, Zhiqiang; Xie, Yunchang; Hu, Fuqiang; Yuan, Hailong; Wu, Wei

2014-02-01

The main purpose of this study was to prepare binary lipids-based nanostructured lipid carriers to improve the oral bioavailability of silymarin, a poorly water-soluble liver protectant. Silymarin-loaded nanostructured lipid carriers were prepared by the method of high-pressure homogenization with glycerol distearates (Precirol ATO-5) and oleic acid as the solid and liquid lipids, respectively, and lecithin (Lipoid E 100) and Tween-80 as the emulsifiers. The silymarin-nanostructured lipid carrier prepared under optimum conditions was spherical in shape with mean particle size of ∼78.87 nm, entrapment efficiency of 87.55%, loading capacity of 8.32%, and zeta potential of -65.3 mV, respectively. In vitro release of silymarin-nanostructured lipid carriers was very limited even after 12 h, while in vitro lipolysis showed fast digestion of nanostructured lipid carriers within 1 h. Relative oral bioavailability of silymarin-nanostructured lipid carriers in Beagle dogs was 2.54- and 3.10-fold that of marketed Legalon® and silymarin solid dispersion pellets, respectively. It was concluded that nanostructured lipid carriers were potential drug delivery systems to improve the bioavailability of silymarin. Other than improved dissolution, alternative mechanisms such as facilitated absorption as well as lymphatic transport may contribute to bioavailability enhancement.

Interfacial & colloidal aspects of lipid digestion.

PubMed

Wilde, P J; Chu, B S

2011-06-09

chain fatty acids, particularly the very long chain n-3 fatty acids from fish oils are dependent on source and so may depend on food microstructure for optimal uptake [3]. The uptake of some poorly water soluble nutrients are enhanced by the presence of lipids, but the mechanisms are not clear. In addition, controlling the digestion of lipids can be beneficial as slower release of lipids into the bloodstream can reduce risk of cardiovascular disease, and can promote gut feedback processes that reduce appetite. This presents an opportunity to colloid and interfacial science, as there are many unanswered questions regarding the specific physicochemical mechanisms underlying the process of lipid digestion and uptake. I will review our current knowledge of lipid digestion and present examples of how fundamental research in colloidal and interface science is beginning to address these issues. These include the adsorption behaviour of physiological surfactants such as bile salts; interfacial processes by which different polar lipids can influence lipolysis; and the effect of emulsion based delivery systems on cellular uptake of lipid soluble nutrients. A fundamental understanding of these processes is required if we are to develop intelligent design strategies for foods that will deliver optimal nutrition and improved health benefits in order to address the global challenges facing the food sector in the future. Copyright © 2011 Elsevier B.V. All rights reserved.

Lipid biomarkers of thermal stress in scleractinian corals

NASA Astrophysics Data System (ADS)

Kneeland, J. M.; Hughen, K.; Cervino, J.; Eglinton, T. I.; Bartels, E.

2007-12-01

Lipid content and fatty acid profiles of corals and their symbiotic dinoflagellates are known to vary in response to heat stress and bleaching. To develop lipid biomarkers of heat stress and bleaching response in scleractinian corals, clones of Symbiodinium algae of clade subtypes C1 and D1 were cultured under a range of temperatures. The predominant lipids produced are palmitic (C16) and stearic (C18) saturated fatty acids and their unsaturated analogs. Other important compounds included a C22 penta-unsaturated fatty acid, which is thought to be a specific dinoflagellate marker, and a variety of sterols. Analysis of lipids extracted from coral skeleton indicated that palmitic and stearic acids were the most abundant compounds. The amount of unsaturated C16 and C18 fatty acids in coral skeleton relative to the saturated versions of those acids was much lower in coral skeleton than in the zooxanthellae tissue. This could indicate the incorporation of lipids from outside the coral host-symbiont system into the coral aragonite, or it could reflect diagenesis. A comparison between the lipids found in cloned zooxanthellae, coral tissue, and aragonitic skeleton will be presented to assess the usefulness of lipid biomarkers as indicators of temperature stress on corals.

Immobilized lipid-bilayer materials

DOEpatents

Sasaki, Darryl Y.; Loy, Douglas A.; Yamanaka, Stacey A.

2000-01-01

A method for preparing encapsulated lipid-bilayer materials in a silica matrix comprising preparing a silica sol, mixing a lipid-bilayer material in the silica sol and allowing the mixture to gel to form the encapsulated lipid-bilayer material. The mild processing conditions allow quantitative entrapment of pre-formed lipid-bilayer materials without modification to the material's spectral characteristics. The method allows for the immobilization of lipid membranes to surfaces. The encapsulated lipid-bilayer materials perform as sensitive optical sensors for the detection of analytes such as heavy metal ions and can be used as drug delivery systems and as separation devices.

Lipid profile, cardiovascular disease and mortality in a Mediterranean high-risk population: The ESCARVAL-RISK study

PubMed Central

Orozco-Beltran, Domingo; Gil-Guillen, Vicente F.; Redon, Josep; Martin-Moreno, Jose M.; Pallares-Carratala, Vicente; Navarro-Perez, Jorge; Valls-Roca, Francisco; Sanchis-Domenech, Carlos; Fernandez-Gimenez, Antonio; Perez-Navarro, Ana; Bertomeu-Martinez, Vicente; Bertomeu-Gonzalez, Vicente; Cordero, Alberto; Pascual de la Torre, Manuel; Trillo, Jose L.; Carratala-Munuera, Concepcion; Pita-Fernandez, Salvador; Uso, Ruth; Durazo-Arvizu, Ramon; Cooper, Richard; Sanz, Gines; Castellano, Jose M.; Ascaso, Juan F.; Carmena, Rafael; Tellez-Plaza, Maria

2017-01-01

Introduction The potential impact of targeting different components of an adverse lipid profile in populations with multiple cardiovascular risk factors is not completely clear. This study aims to assess the association between different components of the standard lipid profile with all-cause mortality and hospitalization due to cardiovascular events in a high-risk population. Methods This prospective registry included high risk adults over 30 years old free of cardiovascular disease (2008–2012). Diagnosis of hypertension, dyslipidemia or diabetes mellitus was inclusion criterion. Lipid biomarkers were evaluated. Primary endpoints were all-cause mortality and hospital admission due to coronary heart disease or stroke. We estimated adjusted rate ratios (aRR), absolute risk differences and population attributable risk associated with adverse lipid profiles. Results 51,462 subjects were included with a mean age of 62.6 years (47.6% men). During an average follow-up of 3.2 years, 919 deaths, 1666 hospitalizations for coronary heart disease and 1510 hospitalizations for stroke were recorded. The parameters that showed an increased rate for total mortality, coronary heart disease and stroke hospitalization were, respectively, low HDL-Cholesterol: aRR 1.25, 1.29 and 1.23; high Total/HDL-Cholesterol: aRR 1.22, 1.38 and 1.25; and high Triglycerides/HDL-Cholesterol: aRR 1.21, 1.30, 1.09. The parameters that showed highest population attributable risk (%) were, respectively, low HDL-Cholesterol: 7.70, 11.42, 8.40; high Total/HDL-Cholesterol: 6.55, 12.47, 8.73; and high Triglycerides/HDL-Cholesterol: 8.94, 15.09, 6.92. Conclusions In a population with cardiovascular risk factors, HDL-cholesterol, Total/HDL-cholesterol and triglycerides/HDL-cholesterol ratios were associated with a higher population attributable risk for cardiovascular disease compared to other common biomarkers. PMID:29045483

Lipid profile, cardiovascular disease and mortality in a Mediterranean high-risk population: The ESCARVAL-RISK study.

PubMed

Orozco-Beltran, Domingo; Gil-Guillen, Vicente F; Redon, Josep; Martin-Moreno, Jose M; Pallares-Carratala, Vicente; Navarro-Perez, Jorge; Valls-Roca, Francisco; Sanchis-Domenech, Carlos; Fernandez-Gimenez, Antonio; Perez-Navarro, Ana; Bertomeu-Martinez, Vicente; Bertomeu-Gonzalez, Vicente; Cordero, Alberto; Pascual de la Torre, Manuel; Trillo, Jose L; Carratala-Munuera, Concepcion; Pita-Fernandez, Salvador; Uso, Ruth; Durazo-Arvizu, Ramon; Cooper, Richard; Sanz, Gines; Castellano, Jose M; Ascaso, Juan F; Carmena, Rafael; Tellez-Plaza, Maria

2017-01-01

The potential impact of targeting different components of an adverse lipid profile in populations with multiple cardiovascular risk factors is not completely clear. This study aims to assess the association between different components of the standard lipid profile with all-cause mortality and hospitalization due to cardiovascular events in a high-risk population. This prospective registry included high risk adults over 30 years old free of cardiovascular disease (2008-2012). Diagnosis of hypertension, dyslipidemia or diabetes mellitus was inclusion criterion. Lipid biomarkers were evaluated. Primary endpoints were all-cause mortality and hospital admission due to coronary heart disease or stroke. We estimated adjusted rate ratios (aRR), absolute risk differences and population attributable risk associated with adverse lipid profiles. 51,462 subjects were included with a mean age of 62.6 years (47.6% men). During an average follow-up of 3.2 years, 919 deaths, 1666 hospitalizations for coronary heart disease and 1510 hospitalizations for stroke were recorded. The parameters that showed an increased rate for total mortality, coronary heart disease and stroke hospitalization were, respectively, low HDL-Cholesterol: aRR 1.25, 1.29 and 1.23; high Total/HDL-Cholesterol: aRR 1.22, 1.38 and 1.25; and high Triglycerides/HDL-Cholesterol: aRR 1.21, 1.30, 1.09. The parameters that showed highest population attributable risk (%) were, respectively, low HDL-Cholesterol: 7.70, 11.42, 8.40; high Total/HDL-Cholesterol: 6.55, 12.47, 8.73; and high Triglycerides/HDL-Cholesterol: 8.94, 15.09, 6.92. In a population with cardiovascular risk factors, HDL-cholesterol, Total/HDL-cholesterol and triglycerides/HDL-cholesterol ratios were associated with a higher population attributable risk for cardiovascular disease compared to other common biomarkers.

Lipid Peroxidation and Transforming Growth Factor-β1 Levels in Gastric Cancer at Pathologic Stages.

PubMed

Tüzün, Sefa; Yücel, Ahmet Fikret; Pergel, Ahmet; Kemik, Ahu Sarbay; Kemik, Ozgür

2012-09-01

High levels of TGF-β1 and enhanced TGF-β1 receptor signaling are related to the pathology of gastric cancer. This effect is caused by oxidative stress and lipid peroxidation products. The aim of this study was to investigate the levels of TGF-β1 and lipid peroxidation products in gastric cancer patients and their correlation with pathologic stage. Lipid peroxidation products and TGF-β1 levels were studied in the serum samples of 50 gastric cancer patients and 18 control subjects. HNE-protein adducts and TGF-β1 levels were significantly higher in T2, T3 and T4 gastric cancers than in either the T1 stage or controls (p<0.001). Pathologic stage was correlated with TGF-β1 levels (r=0.702, p<0.05). These markers production may contribute to tumor angiogenesis and aid in the prognosis of the gastric cancer.

Medical Student Response to a Class Lipid-Screening Project.

ERIC Educational Resources Information Center

Lum, Gifford; And Others

1982-01-01

Medical students at the State University of New York's Downstate Medical Center initiated and carried out a voluntary project to screen lipids (cholesterol) to identify known coronary risk factors. The incidence of coronary disease factors among these students and the response of students with high cholesterol levels are reported. (Authors/PP)

Alcohol and lipid metabolism

PubMed Central

Sozio, Margaret; Crabb, David W.

2008-01-01

Many new mechanisms for alcoholic steatosis have been suggested by work reported in the last five years. These include alterations of transcriptional controls of lipid metabolism, better understanding of the effects of abnormal methionine metabolism on the endoplasmic reticulum stress response, unraveling of the basis for sensitization of the Kupffer cell to lipopolysaccharide, a better understanding of the role of cytokines and adipokines in alcoholic liver disease, and implication of the innate immune and complement systems in responses to alcohol. Much of this work has been facilitated by work with knockout mice. Undoubtedly, there are interrelationships among these various pathogenic mechanisms that ultimately will provide a more cohesive picture of how heavy alcohol use deranges hepatic lipid metabolism. PMID:18349117

LipidPioneer: A Comprehensive User-Generated Exact Mass Template for Lipidomics

PubMed Central

Ulmer, Candice Z.; Koelmel, Jeremy P.; Ragland, Jared M.; Garrett, Timothy J.

2017-01-01

Lipidomics, the comprehensive measurement of lipid species in a biological system, has promising potential in biomarker discovery and disease etiology elucidation. Advances in chromatographic separation, mass spectrometric techniques, and novel substrate applications continue to expand the number of lipid species observed. The total number and type of lipid species detected in a given sample are generally indicative of the sample matrix examined (e.g. serum, plasma, cells, bacteria, tissue, etc.). Current exact mass lipid libraries are static and represent the most commonly analyzed matrices. It is common practice for users to manually curate their own lists of lipid species and adduct masses; however, this process is time-consuming. LipidPioneer, an interactive template, can be used to generate exact masses and molecular formulas of lipid species that may be encountered in the mass spectrometric analysis of lipid profiles. Over 60 lipid classes are present in the LipidPioneer template, and include several unique lipid species, such as ether-linked lipids and lipid oxidation products. In the template, users can add any fatty acyl constituents without limitation in the number of carbons or degrees of unsaturation. LipidPioneer accepts naming using the lipid class level (sum composition) and the LIPID MAPS notation for fatty acyl structure level. In addition to lipid identification, user generated lipid m/z values can be used to develop inclusion lists for targeted fragmentation experiments. Resulting lipid names and m/z values can be imported into software such as MZmine or Compound Discoverer to automate exact mass searching and isotopic pattern matching across experimental data. PMID:28074328

Trifunctional lipid probes for comprehensive studies of single lipid species in living cells

PubMed Central

Nadler, André; Haberkant, Per; Kirkpatrick, Joanna; Schifferer, Martina; Stein, Frank; Hauke, Sebastian; Porter, Forbes D.; Schultz, Carsten

2017-01-01

Lipid-mediated signaling events regulate many cellular processes. Investigations of the complex underlying mechanisms are difficult because several different methods need to be used under varying conditions. Here we introduce multifunctional lipid derivatives to study lipid metabolism, lipid−protein interactions, and intracellular lipid localization with a single tool per target lipid. The probes are equipped with two photoreactive groups to allow photoliberation (uncaging) and photo–cross-linking in a sequential manner, as well as a click-handle for subsequent functionalization. We demonstrate the versatility of the design for the signaling lipids sphingosine and diacylglycerol; uncaging of the probe for these two species triggered calcium signaling and intracellular protein translocation events, respectively. We performed proteomic screens to map the lipid-interacting proteome for both lipids. Finally, we visualized a sphingosine transport deficiency in patient-derived Niemann−Pick disease type C fibroblasts by fluorescence as well as correlative light and electron microscopy, pointing toward the diagnostic potential of such tools. We envision that this type of probe will become important for analyzing and ultimately understanding lipid signaling events in a comprehensive manner. PMID:28154130

Lipid melting and cuticular permeability: new insights into an old problem.

PubMed

Gibbs, Allen G.

2002-04-01

The idea that the physical properties of cuticular lipids affect cuticular permeability goes back over 65 years. This proposal has achieved textbook status, despite controversy and the general lack of direct supporting evidence. Recent work supports the standard model, in which lipid melting results in increased cuticular permeability. Surprisingly, although all species studied to date can synthesize lipids that remain in a solid state at environmental temperatures, partial melting often occurs due to the deposition of lipids with low melting points. This will tend to increase water loss; the benefits may include better dispersal of lipids or other compounds across the cuticle or improved communication via cuticular pheromones. In addition, insects with high melting-point lipids are not necessarily less permeable at low temperatures. One likely reason is variation in lipid properties within the cuticle. Surface lipids differ from one region to another, and biophysical studies of model mixtures suggest the occurrence of phase separation between melted and solid lipid fractions. Lipid phase separation may have important implications for insect water balance and chemical communication.

Cell-sized asymmetric lipid vesicles facilitate the investigation of asymmetric membranes

NASA Astrophysics Data System (ADS)

Kamiya, Koki; Kawano, Ryuji; Osaki, Toshihisa; Akiyoshi, Kazunari; Takeuchi, Shoji

2016-09-01

Asymmetric lipid giant vesicles have been used to model the biochemical reactions in cell membranes. However, methods for producing asymmetric giant vesicles lead to the inclusion of an organic solvent layer that affects the mechanical and physical characteristics of the membrane. Here we describe the formation of asymmetric giant vesicles that include little organic solvent, and use them to investigate the dynamic responses of lipid molecules in the vesicle membrane. We formed the giant vesicles via the inhomogeneous break-up of a lipid microtube generated by applying a jet flow to an asymmetric planar lipid bilayer. The asymmetric giant vesicles showed a lipid flip-flop behaviour in the membrane, superficially similar to the lipid flip-flop activity observed in apoptotic cells. In vitro synthesis of membrane proteins into the asymmetric giant vesicles revealed that the lipid asymmetry in bilayer membranes improves the reconstitution ratio of membrane proteins. Our asymmetric giant vesicles will be useful in elucidating lipid-lipid and lipid-membrane protein interactions involved in the regulation of cellular functions.

Parenteral Nutrition and Lipids.

PubMed

Raman, Maitreyi; Almutairdi, Abdulelah; Mulesa, Leanne; Alberda, Cathy; Beattie, Colleen; Gramlich, Leah

2017-04-14

Lipids have multiple physiological roles that are biologically vital. Soybean oil lipid emulsions have been the mainstay of parenteral nutrition lipid formulations for decades in North America. Utilizing intravenous lipid emulsions in parenteral nutrition has minimized the dependence on dextrose as a major source of nonprotein calories and prevents the clinical consequences of essential fatty acid deficiency. Emerging literature has indicated that there are benefits to utilizing alternative lipids such as olive/soy-based formulations, and combination lipids such as soy/MCT/olive/fish oil, compared with soybean based lipids, as they have less inflammatory properties, are immune modulating, have higher antioxidant content, decrease risk of cholestasis, and improve clinical outcomes in certain subgroups of patients. The objective of this article is to review the history of IVLE, their composition, the different generations of widely available IVLE, the variables to consider when selecting lipids, and the complications of IVLE and how to minimize them.

Parenteral Nutrition and Lipids

PubMed Central

Raman, Maitreyi; Almutairdi, Abdulelah; Mulesa, Leanne; Alberda, Cathy; Beattie, Colleen; Gramlich, Leah

2017-01-01

Lipids have multiple physiological roles that are biologically vital. Soybean oil lipid emulsions have been the mainstay of parenteral nutrition lipid formulations for decades in North America. Utilizing intravenous lipid emulsions in parenteral nutrition has minimized the dependence on dextrose as a major source of nonprotein calories and prevents the clinical consequences of essential fatty acid deficiency. Emerging literature has indicated that there are benefits to utilizing alternative lipids such as olive/soy-based formulations, and combination lipids such as soy/MCT/olive/fish oil, compared with soybean based lipids, as they have less inflammatory properties, are immune modulating, have higher antioxidant content, decrease risk of cholestasis, and improve clinical outcomes in certain subgroups of patients. The objective of this article is to review the history of IVLE, their composition, the different generations of widely available IVLE, the variables to consider when selecting lipids, and the complications of IVLE and how to minimize them. PMID:28420095

In rats fed high-energy diets, taste, rather than fat content, is the key factor increasing food intake: a comparison of a cafeteria and a lipid-supplemented standard diet.

PubMed

Oliva, Laia; Aranda, Tània; Caviola, Giada; Fernández-Bernal, Anna; Alemany, Marià; Fernández-López, José Antonio; Remesar, Xavier

2017-01-01

Food selection and ingestion both in humans and rodents, often is a critical factor in determining excess energy intake and its related disorders. Two different concepts of high-fat diets were tested for their obesogenic effects in rats; in both cases, lipids constituted about 40% of their energy intake. The main difference with controls fed standard lab chow, was, precisely, the lipid content. Cafeteria diets (K) were self-selected diets devised to be desirable to the rats, mainly because of its diverse mix of tastes, particularly salty and sweet. This diet was compared with another, more classical high-fat (HF) diet, devised not to be as tasty as K, and prepared by supplementing standard chow pellets with fat. We also analysed the influence of sex on the effects of the diets. K rats grew faster because of a high lipid, sugar and protein intake, especially the males, while females showed lower weight but higher proportion of body lipid. In contrast, the weight of HF groups were not different from controls. Individual nutrient's intake were analysed, and we found that K rats ingested large amounts of both disaccharides and salt, with scant differences of other nutrients' proportion between the three groups. The results suggest that the key differential factor of the diet eliciting excess energy intake was the massive presence of sweet and salty tasting food. The significant presence of sugar and salt appears as a powerful inducer of excess food intake, more effective than a simple (albeit large) increase in the diet's lipid content. These effects appeared already after a relatively short treatment. The differential effects of sex agree with their different hedonic and obesogenic response to diet.

No Evidence for Spontaneous Lipid Transfer at ER-PM Membrane Contact Sites.

PubMed

Merklinger, Elisa; Schloetel, Jan-Gero; Spitta, Luis; Thiele, Christoph; Lang, Thorsten

2016-04-01

Non-vesicular lipid transport steps play a crucial role in lipid trafficking and potentially include spontaneous exchange. Since membrane contact facilitates this lipid transfer, it is most likely to occur at membrane contact sites (MCS). However, to date it is unknown whether closely attached biological membranes exchange lipids spontaneously. We have set up a system for studying the exchange of lipids at MCS formed between the endoplasmic reticulum (ER) and the plasma membrane. Contact sites were stably anchored and the lipids cholesterol and phosphatidylcholine (PC) were not capable of transferring spontaneously into the opposed bilayer. We conclude that physical contact between two associated biological membranes is not sufficient for transfer of the lipids PC and cholesterol.

Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

ABSTRACT Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeastYarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism inY. lipolytica. Deletion of the GATA transcription factor genesgzf3andgzf2resulted in nitrogen source-specific growth defects and greater accumulation of lipids when the cells weremore » growing on a simple nitrogen source. Deletion ofgzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion ofgzf3results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, whilegzf2is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressormig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism. IMPORTANCENitrogen source is commonly used to control lipid production in industrial fungi. Here we identified regulators of nitrogen catabolite repression in the oleaginous yeast

Alkyl ether lipids, ion channels and lipid raft reorganization in cancer therapy.

PubMed

Jaffrès, Paul-Alain; Gajate, Consuelo; Bouchet, Ana Maria; Couthon-Gourvès, Hélène; Chantôme, Aurélie; Potier-Cartereau, Marie; Besson, Pierre; Bougnoux, Philippe; Mollinedo, Faustino; Vandier, Christophe

2016-09-01

Synthetic alkyl lipids, such as the ether lipids edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) and ohmline (1-O-hexadecyl-2-O-methyl-rac-glycero-3-β-lactose), are forming a class of antitumor agents that target cell membranes to induce apoptosis and to decrease cell migration/invasion, leading to the inhibition of tumor and metastasis development. In this review, we present the structure-activity relationship of edelfosine and ohmline, and we point out differences and similarities between these two amphiphilic compounds. We also discuss the mechanisms of action of these synthetic alkyl ether lipids (involving, among other structures and molecules, membrane domains, Fas/CD95 death receptor signaling, and ion channels), and highlight a key role for lipid rafts in the underlying process. The reorganization of lipid raft membrane domains induced by these alkyl lipids affects the function of death receptors and ion channels, thus leading to apoptosis and/or inhibition of cancer cell migration. The possible therapeutic use of these alkyl lipids and the clinical perspectives for these lipids in prevention or/and treatment of tumor development and metastasis are also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Lipid signalling couples translational surveillance to systemic detoxification in Caenorhabditis elegans

PubMed Central

Govindan, J. Amaranath; Jayamani, Elamparithi; Zhang, Xinrui; Breen, Peter; Larkins-Ford, Jonah; Mylonakis, Eleftherios

2015-01-01

Translation in eukaryotes is surveilled to detect toxins and virulence factors and coupled to the induction of defense pathways. C. elegans germline-specific mutations in translation components are detected by this system to induce detoxification and immune responses in distinct somatic cells. An RNAi screen revealed gene inactivations that act at multiple steps in lipid biosynthetic and kinase pathways that act upstream of MAP kinase to mediate the systemic communication of translation-defects to induce detoxification genes. Mammalian bile acids can rescue the defect in detoxification gene induction caused by C. elegans lipid biosynthetic gene inactivations. Extracts prepared from C. elegans with translation deficits but not from wild type can also rescue detoxification gene induction in lipid biosynthetic defective strains. These eukaryotic antibacterial countermeasures are not ignored by bacteria: particular bacterial species suppress normal C. elegans detoxification responses to mutations in translation factors. PMID:26322678

Increased lipid droplet accumulation associated with a peripheral sensory neuropathy.

PubMed

Marshall, Lee L; Stimpson, Scott E; Hyland, Ryan; Coorssen, Jens R; Myers, Simon J

2014-04-01

Hereditary sensory neuropathy type 1 (HSN-1) is an autosomal dominant neurodegenerative disease caused by missense mutations in the SPTLC1 gene. The SPTLC1 protein is part of the SPT enzyme which is a ubiquitously expressed, critical and thus highly regulated endoplasmic reticulum bound membrane enzyme that maintains sphingolipid concentrations and thus contributes to lipid metabolism, signalling, and membrane structural functions. Lipid droplets are dynamic organelles containing sphingolipids and membrane bound proteins surrounding a core of neutral lipids, and thus mediate the intracellular transport of these specific molecules. Current literature suggests that there are increased numbers of lipid droplets and alterations of lipid metabolism in a variety of other autosomal dominant neurodegenerative diseases, including Alzheimer's and Parkinson's disease. This study establishes for the first time, a significant increase in the presence of lipid droplets in HSN-1 patient-derived lymphoblasts, indicating a potential connection between lipid droplets and the pathomechanism of HSN-1. However, the expression of adipophilin (ADFP), which has been implicated in the regulation of lipid metabolism, was not altered in lipid droplets from the HSN-1 patient-derived lymphoblasts. This appears to be the first report of increased lipid body accumulation in a peripheral neuropathy, suggesting a fundamental molecular linkage between a number of neurodegenerative diseases.

Synthetic lipids and their role in defining macromolecular assemblies.

PubMed

Parrill, Abby L

2015-10-01

Lipids have a variety of physiological roles, ranging from structural and biophysical contributions to membrane functions to signaling contributions in normal and abnormal physiology. This review highlights some of the contributions made by Robert Bittman to our understanding of lipid assemblies through the production of synthetic lipid analogs in the sterol, sphingolipid, and glycolipid classes. His contributions have included the development of a fluorescent cholesterol analog that shows strong functional analogies to cholesterol that has allowed live imaging of cholesterol distribution in living systems, to stereospecific synthetic approaches to both sphingolipid and glycolipid analogs crucial in defining the structure-activity relationships of lipid biological targets. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Biodegradable lipids enabling rapidly eliminated lipid nanoparticles for systemic delivery of RNAi therapeutics.

PubMed

Maier, Martin A; Jayaraman, Muthusamy; Matsuda, Shigeo; Liu, Ju; Barros, Scott; Querbes, William; Tam, Ying K; Ansell, Steven M; Kumar, Varun; Qin, June; Zhang, Xuemei; Wang, Qianfan; Panesar, Sue; Hutabarat, Renta; Carioto, Mary; Hettinger, Julia; Kandasamy, Pachamuthu; Butler, David; Rajeev, Kallanthottathil G; Pang, Bo; Charisse, Klaus; Fitzgerald, Kevin; Mui, Barbara L; Du, Xinyao; Cullis, Pieter; Madden, Thomas D; Hope, Michael J; Manoharan, Muthiah; Akinc, Akin

2013-08-01

In recent years, RNA interference (RNAi) therapeutics, most notably with lipid nanoparticle-based delivery systems, have advanced into human clinical trials. The results from these early clinical trials suggest that lipid nanoparticles (LNPs), and the novel ionizable lipids that comprise them, will be important materials in this emerging field of medicine. A persistent theme in the use of materials for biomedical applications has been the incorporation of biodegradability as a means to improve biocompatibility and/or to facilitate elimination. Therefore, the aim of this work was to further advance the LNP platform through the development of novel, next-generation lipids that combine the excellent potency of the most advanced lipids currently available with biodegradable functionality. As a representative example of this novel class of biodegradable lipids, the lipid evaluated in this work displays rapid elimination from plasma and tissues, substantially improved tolerability in preclinical studies, while maintaining in vivo potency on par with that of the most advanced lipids currently available.

Toward the establishment of standardized in vitro tests for lipid-based formulations, part 4: proposing a new lipid formulation performance classification system.

PubMed

Williams, Hywel D; Sassene, Philip; Kleberg, Karen; Calderone, Marilyn; Igonin, Annabel; Jule, Eduardo; Vertommen, Jan; Blundell, Ross; Benameur, Hassan; Müllertz, Anette; Porter, Christopher J H; Pouton, Colin W

2014-08-01

The Lipid Formulation Classification System Consortium looks to develop standardized in vitro tests and to generate much-needed performance criteria for lipid-based formulations (LBFs). This article highlights the value of performing a second, more stressful digestion test to identify LBFs near a performance threshold and to facilitate lead formulation selection in instances where several LBF prototypes perform adequately under standard digestion conditions (but where further discrimination is necessary). Stressed digestion tests can be designed based on an understanding of the factors that affect LBF performance, including the degree of supersaturation generated on dispersion/digestion. Stresses evaluated included decreasing LBF concentration (↓LBF), increasing bile salt, and decreasing pH. Their capacity to stress LBFs was dependent on LBF composition and drug type: ↓LBF was a stressor to medium-chain glyceride-rich LBFs, but not more hydrophilic surfactant-rich LBFs, whereas decreasing pH stressed tolfenamic acid LBFs, but not fenofibrate LBFs. Lastly, a new Performance Classification System, that is, LBF composition independent, is proposed to promote standardized LBF comparisons, encourage robust LBF development, and facilitate dialogue with the regulatory authorities. This classification system is based on the concept that performance evaluations across three in vitro tests, designed to subject a LBF to progressively more challenging conditions, will enable effective LBF discrimination and performance grading. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

The physiology of lipid storage and use in reptiles.

PubMed

Price, Edwin R

2017-08-01

Lipid metabolism is central to understanding whole-animal energetics. Reptiles store most excess energy in lipid form, mobilise those lipids when needed to meet energetic demands, and invest lipids in eggs to provide the primary source of energy to developing embryos. Here, I review the mechanisms by which non-avian reptiles store, transport, and use lipids. Many aspects of lipid absorption, transport, and storage appear to be similar to birds, including the hepatic synthesis of lipids from glucose substrates, the transport of triglycerides in lipoproteins, and the storage of lipids in adipose tissue, although adipose tissue in non-avian reptiles is usually concentrated in abdominal fat bodies or the tail. Seasonal changes in fat stores suggest that lipid storage is primarily for reproduction in most species, rather than for maintenance during aphagic periods. The effects of fasting on plasma lipid metabolites can differ from mammals and birds due to the ability of non-avian reptiles to reduce their metabolism drastically during extended fasts. The effect of fasting on levels of plasma ketones is species specific: β-hydroxybutyrate concentration may rise or fall during fasting. I also describe the process by which the bulk of lipids are deposited into oocytes during vitellogenesis. Although this process is sometimes ascribed to vitellogenin-based transport in reptiles, the majority of lipid deposition occurs via triglycerides packaged in very-low-density lipoproteins (VLDLs), based on physiological, histological, biochemical, comparative, and genomic evidence. I also discuss the evidence for non-avian reptiles using 'yolk-targeted' VLDLs during vitellogenesis. The major physiological states - feeding, fasting, and vitellogenesis - have different effects on plasma lipid metabolites, and I discuss the possibilities and potential problems of using plasma metabolites to diagnose feeding condition in non-avian reptiles. © 2016 Cambridge Philosophical Society.

Essential oil-loaded lipid nanoparticles for wound healing

PubMed Central

Saporito, Francesca; Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Boselli, Cinzia; Icaro Cornaglia, Antonia; Mannucci, Barbara; Grisoli, Pietro; Vigani, Barbara; Ferrari, Franca

2018-01-01

Chronic wounds and severe burns are diseases responsible for severe morbidity and even death. Wound repair is a crucial process and tissue regeneration enhancement and infection prevention are key factors to minimize pain, discomfort, and scar formation. The aim of this work was the development of lipid nanoparticles (solid lipid nanoparticles and nanostructured lipid carriers [NLC]), to be loaded with eucalyptus or rosemary essential oils and to be used, as medical devices, to enhance healing of skin wounds. Lipid nanoparticles were based on natural lipids: cocoa butter, as solid lipid, and olive oil or sesame oil, as liquid lipids. Lecithin was chosen as surfactant to stabilize nanoparticles and to prevent their aggregation. The systems were prepared by high shear homogenization followed by ultrasound application. Nanoparticles were characterized for physical–chemical properties, bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward normal human dermal fibroblasts. Antimicrobial activity of nanoparticles was evaluated against two reference microbial strains, one of Staphylococcus aureus, the other of Streptococcus pyogenes. Finally, the capability of nanoparticles to promote wound healing in vivo was evaluated on a rat burn model. NLC based on olive oil and loaded with eucalyptus oil showed appropriate physical–chemical properties, good bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward fibroblasts, associated to antimicrobial properties. Moreover, the in vivo results evidenced the capability of these NLC to enhance the healing process. Olive oil, which is characterized by a high content of oleic acid, proved to exert a synergic effect with eucalyptus oil with respect to antimicrobial activity and wound repair promotion. PMID:29343956

Electrostatic swelling of bicontinuous cubic lipid phases.

PubMed

Tyler, Arwen I I; Barriga, Hanna M G; Parsons, Edward S; McCarthy, Nicola L C; Ces, Oscar; Law, Robert V; Seddon, John M; Brooks, Nicholas J

2015-04-28

Lipid bicontinuous cubic phases have attracted enormous interest as bio-compatible scaffolds for use in a wide range of applications including membrane protein crystallisation, drug delivery and biosensing. One of the major bottlenecks that has hindered exploitation of these structures is an inability to create targeted highly swollen bicontinuous cubic structures with large and tunable pore sizes. In contrast, cubic structures found in vivo have periodicities approaching the micron scale. We have been able to engineer and control highly swollen bicontinuous cubic phases of spacegroup Im3m containing only lipids by (a) increasing the bilayer stiffness by adding cholesterol and (b) inducing electrostatic repulsion across the water channels by addition of anionic lipids to monoolein. By controlling the composition of the ternary mixtures we have been able to achieve lattice parameters up to 470 Å, which is 5 times that observed in pure monoolein and nearly twice the size of any lipidic cubic phase reported previously. These lattice parameters significantly exceed the predicted maximum swelling for bicontinuous cubic lipid structures, which suggest that thermal fluctuations should destroy such phases for lattice parameters larger than 300 Å.

Regulation of nitrogen metabolism by GATA zinc finger transcription factors in Yarrowia lipolytica

DOE PAGES

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.; ...

2017-02-15

Here, fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism in Y. lipolytica. Deletion of the GATA transcription factor genes gzf3 and gzf2 resulted in nitrogen source-specific growth defects and greatermore » accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion of gzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion of gzf3 results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, while gzf2 is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressor mig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.« less

Regulation of nitrogen metabolism by GATA zinc finger transcription factors in Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

Here, fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism in Y. lipolytica. Deletion of the GATA transcription factor genes gzf3 and gzf2 resulted in nitrogen source-specific growth defects and greatermore » accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion of gzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion of gzf3 results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, while gzf2 is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressor mig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.« less

Current trends to comprehend lipid metabolism in diatoms.

PubMed

Zulu, Nodumo Nokulunga; Zienkiewicz, Krzysztof; Vollheyde, Katharina; Feussner, Ivo

2018-04-01

Diatoms are the most dominant phytoplankton species in oceans and they continue to receive a great deal of attention because of their significant contributions in ecosystems and the environment. Due to triacylglycerol (TAG) profiles that are abundant in medium-chain fatty acids, diatoms have emerged to be better feed stocks for biofuel production, in comparison to the commonly studied green microalgal species (chlorophytes). Importantly, diatoms are also known for their high levels of the essential ω3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and are considered to be a promising alternative source of these components. The two most commonly exploited diatoms include Thalassiosira pseudonana and Phaeodactylum tricornutum. Although obvious similarities between diatoms and chlorophytes exist, there are some substantial differences in their lipid metabolism. This review provides an overview on lipid metabolism in diatoms, with P. tricornutum as the most explored model. Special emphasis is placed on the synthesis and incorporation of very long chain ω3 fatty acids into lipids. Furthermore, current approaches including genetic engineering and biotechnological methods aimed at improving and maximizing lipid production in P. tricornutum are also discussed. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Effect of polyethylene glycol-lipid derivatives on the stability of grafted liposomes].

PubMed

Xu, Yang; Shi, Li; Deng, Yi-hui

2011-10-01

It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.

Studying lipid-protein interactions with electron paramagnetic resonance spectroscopy of spin-labeled lipids.

PubMed

Páli, Tibor; Kóta, Zoltán

2013-01-01

Spin label electron paramagnetic resonance (EPR) of lipid-protein interactions reveals crucial features of the structure and assembly of integral membrane proteins. Spin label EPR spectroscopy is the technique of choice to characterize the protein-solvating lipid shell in its highly dynamic nature, because the EPR spectra of lipids that are spin labeled close to the terminal methyl end of their acyl chains display two spectral components, those corresponding to lipids directly contacting the protein and those corresponding to lipids in the bulk fluid bilayer regions of the membrane. In this chapter, typical spin label EPR procedures are presented that allow determination of the stoichiometry of interaction of spin-labeled lipids with the intra-membranous region of membrane proteins or polypeptides, as well as the association constant of the spin-labeled lipid with respect to the host lipid. The lipids giving rise to the so-called immobile spectral component in the EPR spectrum of such samples are identified as the motionally restricted first-shell lipids solvating membrane proteins in biomembranes. Stoichiometry and selectivity are directly related to the structure of the intra-membranous sections of membrane-associated proteins or polypeptides and can be used to study the state of assembly of such proteins in the membrane. Since these characteristics of lipid-protein interactions are discussed in detail in the literature [see Marsh (Eur Biophys J 39:513-525, 2010) for a most recent review], here we focus more on how to spin label model and biomembranes and how to measure and analyze the two-component EPR spectra of spin-labeled lipids in phospholipid bilayers that contain proteins or polypeptides. After a description of how to prepare spin-labeled model and native biological membranes, we present the reader with computational procedures for determining the molar fraction of motionally restricted lipids when both, one, or none of the pure isolated-mobile or

Ionization behavior of amino lipids for siRNA delivery: determination of ionization constants, SAR, and the impact of lipid pKa on cationic lipid-biomembrane interactions.

PubMed

Zhang, Jingtao; Fan, Haihong; Levorse, Dorothy A; Crocker, Louis S

2011-03-01

Ionizable amino lipids are being pursued as an important class of materials for delivering small interfering RNA (siRNA) therapeutics, and research is being conducted to elucidate the structure-activity relationships (SAR) of these lipids. The pK(a) of cationic lipid headgroups is one of the critical physiochemical properties of interest due to the strong impact of lipid ionization on the assembly and performance of these lipids. This research focused on developing approaches that permit the rapid determination of the relevant pK(a) of the ionizable amino lipids. Two distinct approaches were investigated: (1) potentiometric titration of amino lipids dissolved in neutral surfactant micelles; and (2) pH-dependent partitioning of a fluorescent dye to cationic liposomes formulated from amino lipids. Using the approaches developed here, the pK(a) values of cationic lipids with distinct headgroups were measured and found to be significantly lower than calculated values. It was also found that lipid-lipid interaction has a strong impact on the pK(a) values of lipids. Lysis of model biomembranes by cationic lipids was used to evaluate the impact of lipid pK(a) on the interaction between cationic lipids and cell membranes. It was found that cationic lipid-biomembrane interaction depends strongly on lipid pK(a) and solution pH, and this interaction is much stronger when amino lipids are highly charged. The presence of an optimal pK(a) range of ionizable amino lipids for siRNA delivery was suggested based on these results. The pK(a) methods reported here can be used to support the SAR screen of cationic lipids for siRNA delivery, and the information revealed through studying the impact of pK(a) on the interaction between cationic lipids and cell membranes will contribute significantly to the design of more efficient siRNA delivery vehicles.

Drug solubility in lipid nanocarriers: Influence of lipid matrix and available interfacial area.

PubMed

Göke, Katrin; Bunjes, Heike

2017-08-30

Amongst other strategies for the formulation of poorly water-soluble drugs, solubilization of these drugs in lipid-based formulations is a promising option. Most screening methods for the identification of a suitable lipid-based formulation fail to elucidate the role interfacial effects play for drug solubility in disperse systems. In a novel screening approach called passive drug loading, different preformed lipid nanocarrier dispersions are incubated with drug powder. Afterwards, undissolved drug is filtered off and the amount of solubilized drug is determined. The aim of this study was to identify parameters for drug solubility in pure lipids as well as for drug loading to the lipid-water interface of lipid nanoparticles. Using passive loading, the solubility of eight poorly water-soluble drugs in seven lipid nanocarriers varying in particle size or lipid matrix was investigated. Drug solubility in the nanocarriers did not follow any apparent trend and different drugs dissolved best in different carriers. Drugs with a melting point below approximately 150°C displayed distinctly better solubility than higher melting drugs. Additionally, relating the specific lipid nanocarrier surface area to the drug solubility allowed drawing conclusions on the drug localization. Fenofibrate, dibucaine and, less distinctly also clotrimazole, which all melt below 150°C, were predominantly located in the lipid droplet core of the nanoparticles. In contrast, the five remaining drugs (betamethasone valerate, flufenamic acid, itraconazole, ketoconazole, mefenamic acid) were also located at the lipid-water interface to different, but substantial degrees. The ability to account for drug loading to the lipid-water interface is thus a major advantage of passive loading. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of the lipid biomarkers from plasma in idiopathic pulmonary fibrosis by Lipidomics.

PubMed

Yan, Feng; Wen, Zhensong; Wang, Rui; Luo, Wenling; Du, Yufeng; Wang, Wenjun; Chen, Xianyang

2017-12-06

Idiopathic pulmonary fibrosis (IPF) is an irreversible interstitial pulmonary disease featured by high mortality, chronic and progressive course, and poor prognosis with unclear etiology. Currently, more studies have been focusing on identifying biomarkers to predict the progression of IPF, such as genes, proteins, and lipids. Lipids comprise diverse classes of molecules and play a critical role in cellular energy storage, structure, and signaling. The role of lipids in respiratory diseases, including cystic fibrosis, asthma and chronic obstructive pulmonary disease (COPD) has been investigated intensely in the recent years. The human serum lipid profiles in IPF patients however, have not been thoroughly understood and it will be very helpful if there are available molecular biomarkers, which can be used to monitor the disease progression or provide prognostic information for IPF disease. In this study, we performed the ultraperformance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-QTOF/MS) to detect the lipid variation and identify biomarker in plasma of IPF patients. The plasma were from 22 IPF patients before received treatment and 18 controls. A total of 507 individual blood lipid species were determined with lipidomics from the 40 plasma samples including 20 types of fatty acid, 159 types of glycerolipids, 221 types of glycerophospholipids, 47 types of sphingolipids, 46 types of sterol lipids, 7 types of prenol lipids, 3 types of saccharolipids, and 4 types of polyketides. By comparing the variations in the lipid metabolite levels in IPF patients, a total of 62 unique lipids were identified by statistical analysis including 24 kinds of glycerophoslipids, 30 kinds of glycerolipids, 3 kinds of sterol lipids, 4 kinds of sphingolipids and 1 kind of fatty acids. Finally, 6 out of 62 discriminating lipids were selected as the potential biomarkers, which are able to differentiate between IPF disease and controls with ROC

Lipid Peroxidation and Transforming Growth Factor-β1 Levels in Gastric Cancer at Pathologic Stages

PubMed Central

Tüzün, Sefa; Yücel, Ahmet Fikret; Pergel, Ahmet; Kemik, Ahu Sarbay; Kemik, Özgür

2012-01-01

Objective: High levels of TGF-β1 and enhanced TGF-β1 receptor signaling are related to the pathology of gastric cancer. This effect is caused by oxidative stress and lipid peroxidation products. The aim of this study was to investigate the levels of TGF-β1 and lipid peroxidation products in gastric cancer patients and their correlation with pathologic stage. Material and Methods: Lipid peroxidation products and TGF-β1 levels were studied in the serum samples of 50 gastric cancer patients and 18 control subjects. Results: HNE-protein adducts and TGF-β1 levels were significantly higher in T2, T3 and T4 gastric cancers than in either the T1 stage or controls (p<0.001). Pathologic stage was correlated with TGF-β1 levels (r=0.702, p<0.05). Conclusion: These markers production may contribute to tumor angiogenesis and aid in the prognosis of the gastric cancer. PMID:25207013

Lipids of mitochondria.

PubMed

Horvath, Susanne E; Daum, Günther

2013-10-01

A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described. Copyright © 2013 Elsevier Ltd. All rights reserved.

Benefits of commercial weight-loss programs on blood pressure and lipids: a systematic review.

PubMed

Mehta, Ambereen K; Doshi, Ruchi S; Chaudhry, Zoobia W; Jacobs, David K; Vakil, Rachit M; Lee, Clare J; Bleich, Sara N; Clark, Jeanne M; Gudzune, Kimberly A

2016-09-01

Our objective was to compare the effect of commercial weight-loss programs on blood pressure and lipids to control/education or counseling among individuals with overweight/obesity. We conducted a systematic review by searching MEDLINE and Cochrane Database of Systematic Reviews from inception to November 2014 and references identified by the programs. We included randomized, controlled trials ≥12weeks in duration. Two reviewers extracted information on study design, interventions, and mean change in systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), triglycerides, and total cholesterol and assessed risk of bias. We included 27 trials. Participants' blood pressure and lipids were normal at baseline in most trials. At 12months, Weight Watchers showed little change in blood pressure or lipid outcomes as compared to control/education (2 trials). At 12months, Atkins' participants had higher HDL-c and lower triglycerides than counseling (4 trials). Other programs had inconsistent effects or lacked long-term studies. Risk of bias was high for most trials of all programs. In conclusion, limited data exist regarding most commercial weight-loss programs' long-term effects on blood pressure and lipids. Clinicians should be aware that Weight Watchers has limited data that demonstrate CVD risk factor benefits relative to control/education. Atkins may be a reasonable option for patients with dyslipidemia. Additional well-designed, long-term trials are needed to confirm these conclusions and evaluate other commercial programs. Copyright © 2016 Elsevier Inc. All rights reserved.

Chronic hepatitis C infection is associated with insulin resistance and lipid profiles.

PubMed

Dai, Chia-Yen; Yeh, Ming-Lun; Huang, Chung-Feng; Hou, Chen-Hsiu; Hsieh, Ming-Yen; Huang, Jee-Fu; Lin, I-Ling; Lin, Zu-Yau; Chen, Shinn-Chern; Wang, Liang-Yen; Chuang, Wan-Long; Yu, Ming-Lung; Tung, Hung-Da

2015-05-01

Chronic hepatitis C virus (HCV) infection has been suggested to be associated with non-insulin-dependent diabetes mellitus and lipid profiles. This study aimed to investigate the possible relationships of insulin resistance (IR) and lipid profiles with chronic hepatitis C (CHC) patients in Taiwan. We enrolled 160 hospital-based CHC patients with liver biopsy and the 480 controlled individuals without CHC and chronic hepatitis B from communities without known history of non-insulin-dependent diabetes mellitus. Fasting plasma glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), alanine aminotransferase, and serum insulin levels, and homeostasis model assessment (HOMA-IR) were tested. When comparing factors between CHC patients, and sex- and age-matched controls who had no HCV infection, patients with HCV infection had a significantly higher alanine aminotransferase level, fasting plasma glucose level, insulin level, and HOMA-IR (P < 0.001, P = 0.023, P = 0.017, and P = 0.011, respectively), and significantly lower TG level (P = 0.023), total cholesterol, and HDL-C and LDL-C levels (all P < 0.001) than 480 controls. In multivariate logistic regression analyses, a low total cholesterol, a low TGs, and a high HOMA-IR are independent factors significantly associated with chronic HCV infection. In the 160 CHC patients (41 patients with high HOMA-IR [> 2.5]), a high body mass index, TGs, and HCV RNA level are independent factors significantly associated with high HOMA-IR in multivariate logistic analyses. Chronic HCV infection was associated with metabolic characteristics including IR and lipid profile. IR was also associated with virological characteristics. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Lipid Oxidation in Carriers of Lecithin:Cholesterol Acyltransferase Gene Mutations

PubMed Central

Holleboom, Adriaan G.; Daniil, Georgios; Fu, Xiaoming; Zhang, Renliang; Hovingh, G. Kees; Schimmel, Alinda W.; Kastelein, John J.P.; Stroes, Erik S.G.; Witztum, Joseph L.; Hutten, Barbara A.; Tsimikas, Sotirios; Hazen, Stanley L.; Chroni, Angeliki; Kuivenhoven, Jan Albert

2013-01-01

Objective Lecithin:cholesterol acyltransferase (LCAT) has been shown to play a role in the depletion of lipid oxidation products, but this has so far not been studied in humans. In this study, we investigated processes and parameters relevant to lipid oxidation in carriers of functional LCAT mutations. Methods and Results In 4 carriers of 2 mutant LCAT alleles, 63 heterozygotes, and 63 family controls, we measured activities of LCAT, paraoxonase 1, and platelet-activating factor-acetylhydrolase; levels of lysophosphatidylcholine molecular species, arachidonic and linoleic acids, and their oxidized derivatives; immunodetectable oxidized phospholipids on apolipoprotein (apo) B–containing and apo(a)-containing lipoproteins; IgM and IgG autoantibodies to malondialdehyde-low-density lipoprotein and IgG and IgM apoB-immune complexes; and the antioxidant capacity of high-density lipoprotein (HDL). In individuals with LCAT mutations, plasma LCAT activity, HDL cholesterol, apoA-I, arachidonic acid, and its oxidized derivatives, oxidized phospholipids on apo(a)-containing lipoproteins, HDL-associated platelet-activating factor-acetylhydrolase activity, and the antioxidative capacity of HDL were gene-dose–dependently decreased. Oxidized phospholipids on apoB-containing lipoproteins was increased in heterozygotes (17%; P<0.001) but not in carriers of 2 defective LCAT alleles. Conclusion Carriers of LCAT mutations present with significant reductions in LCAT activity, HDL cholesterol, apoA-I, platelet-activating factor-acetylhydrolase activity, and antioxidative potential of HDL, but this is not associated with parameters of increased lipid peroxidation; we did not observe significant changes in the oxidation products of arachidonic acid and linoleic acid, immunoreactive oxidized phospholipids on apo(a)-containing lipoproteins, and IgM and IgG autoantibodies against malondialdehyde-low-density lipoprotein. These data indicate that plasma LCAT activity, HDL

Lysosomal Lipid Storage Diseases

PubMed Central

Schulze, Heike; Sandhoff, Konrad

2011-01-01

Lysosomal lipid storage diseases, or lipidoses, are inherited metabolic disorders in which typically lipids accumulate in cells and tissues. Complex lipids, such as glycosphingolipids, are constitutively degraded within the endolysosomal system by soluble hydrolytic enzymes with the help of lipid binding proteins in a sequential manner. Because of a functionally impaired hydrolase or auxiliary protein, their lipid substrates cannot be degraded, accumulate in the lysosome, and slowly spread to other intracellular membranes. In Niemann-Pick type C disease, cholesterol transport is impaired and unesterified cholesterol accumulates in the late endosome. In most lysosomal lipid storage diseases, the accumulation of one or few lipids leads to the coprecipitation of other hydrophobic substances in the endolysosomal system, such as lipids and proteins, causing a “traffic jam.” This can impair lysosomal function, such as delivery of nutrients through the endolysosomal system, leading to a state of cellular starvation. Therapeutic approaches are currently restricted to mild forms of diseases with significant residual catabolic activities and without brain involvement. PMID:21502308

Lipid interactions in breadmaking.

PubMed

Carr, N O; Daniels, N W; Frazier, P J

1992-01-01

Both the natural lipids of flour and added fats are known to play an important role during the production of bread. In this review, the chemical and physical interactions of fat have been assessed in an attempt to explain these technological functions. Particular emphasis has been placed on the "binding" or complexing of lipid by flour proteins during the development of dough. While publications in this field have frequently been contradictory, evidence now indicates that observed lipid binding may involve lipid mesophase transformation and the nonspecific occlusion of lipid phases within the gluten network. The significance of these suggested events has been compared with current theories of lipid function in the breadmaking process.

Dietary silymarin supplementation promotes growth performance and improves lipid metabolism and health status in grass carp (Ctenopharyngodon idellus) fed diets with elevated lipid levels.

PubMed

Xiao, Peizhen; Ji, Hong; Ye, Yuantu; Zhang, Baotong; Chen, Yongsheng; Tian, Jingjing; Liu, Pin; Chen, Liqiao; Du, Zhenyu

2017-02-01

This study was carried out to evaluate whether silymarin supplementation influences growth, lipid metabolism, and health status in grass carp fed elevated dietary lipid levels. The juvenile fish (27.43 ± 0.17 g/tail) were fed six isonitrogenous and isocaloric diets in a factorial design containing 0, 100, or 200 mg kg -1 silymarin (SM0, SM100, SM200) associated with either 4 or 8 % lipid level (low lipid, LL, and high lipid, HL, respectively) for 82 days. The results showed that both dietary silymarin supplementation and high lipid level significantly enhanced growth performance (WG, SGR), protein efficiency ratio, and feed utilization. Silymarin supplementation significantly reduced the VSI, hepatic lipid content, and the total bilirubin concentration in the serum. The gallbladdersomatic index displayed higher in the SM100 groups than SM200 groups. Serum total cholesterol content exhibited lower in the SM100 groups than SM0 groups. Meanwhile, significant interactions were shown for hepatic gene expression of HSL and CPT1 by two factors, and SM100 group had higher hepatic gene expression of HSL and CPT1 in fish fed with the HL diets. The SM100 groups up-regulated hepatic gene expressions of HMGCR and CYP7A1 compared with the SM0 groups. Silymarin supplementation notably reduced the elevated serum MDA content induced by HL treatments. Thus, silymarin supplementation markedly promoted growth and protein efficiency, suppressed lipid accumulation, and improved health status in grass carp fed with high-lipid diets, which might be associated with its enhancement of lipolysis and β-oxidation, antioxidant capacity.

Involvement of glycosphingolipid-enriched lipid rafts in inflammatory responses.

PubMed

Iwabuchi, Kazuhisa

2015-01-01

Glycosphingolipids (GSLs) are membrane components consisting of hydrophobic ceramide and hydrophilic sugar moieties. GSLs cluster with cholesterol in cell membranes to form GSL-enriched lipid rafts. Biochemical analyses have demonstrated that GSL-enriched lipid rafts contain several kinds of transducer molecules, including Src family kinases. Among the GSLs, lactosylceramide (LacCer, CDw17) can bind to various microorganisms, is highly expressed on the plasma membranes of human phagocytes, and forms lipid rafts containing the Src family tyrosine kinase Lyn. LacCer-enriched lipid rafts mediate immunological and inflammatory reactions, including superoxide generation, chemotaxis, and non-opsonic phagocytosis. Therefore, LacCer-enriched membrane microdomains are thought to function as pattern recognition receptors (PRRs), which recognize pathogen-associated molecular patterns (PAMPs) expressed on microorganisms. LacCer also serves as a signal transduction molecule for functions mediated by CD11b/CD18-integrin (αM/β2-integrin, CR3, Mac-1), as well as being associated with several key cellular processes. LacCer recruits PCKα/ε and phospholipase A2 to stimulate PECAM-1 expression in human monocytes and their adhesion to endothelial cells, as well as regulating β1-integrin clustering and endocytosis on cell surfaces. This review describes the organizational and inflammation-related functions of LacCer-enriched lipid rafts.

Single Lipid Molecule Dynamics on Supported Lipid Bilayers with Membrane Curvature.

PubMed

Cheney, Philip P; Weisgerber, Alan W; Feuerbach, Alec M; Knowles, Michelle K

2017-03-15

The plasma membrane is a highly compartmentalized, dynamic material and this organization is essential for a wide variety of cellular processes. Nanoscale domains allow proteins to organize for cell signaling, endo- and exocytosis, and other essential processes. Even in the absence of proteins, lipids have the ability to organize into domains as a result of a variety of chemical and physical interactions. One feature of membranes that affects lipid domain formation is membrane curvature. To directly test the role of curvature in lipid sorting, we measured the accumulation of two similar lipids, 1,2-Dihexadecanoyl- sn -glycero-3-phosphoethanolamine (DHPE) and hexadecanoic acid (HDA), using a supported lipid bilayer that was assembled over a nanopatterned surface to obtain regions of membrane curvature. Both lipids studied contain 16 carbon, saturated tails and a head group tag for fluorescence microscopy measurements. The accumulation of lipids at curvatures ranging from 28 nm to 55 nm radii was measured and fluorescein labeled DHPE accumulated more than fluorescein labeled HDA at regions of membrane curvature. We then tested whether single biotinylated DHPE molecules sense curvature using single particle tracking methods. Similar to groups of fluorescein labeled DHPE accumulating at curvature, the dynamics of single molecules of biotinylated DHPE was also affected by membrane curvature and highly confined motion was observed.

Dietary Lipid Type, Rather Than Total Number of Calories, Alters Outcomes of Enteric Infection in Mice.

PubMed

DeCoffe, Daniella; Quin, Candice; Gill, Sandeep K; Tasnim, Nishat; Brown, Kirsty; Godovannyi, Artem; Dai, Chuanbin; Abulizi, Nijiati; Chan, Yee Kwan; Ghosh, Sanjoy; Gibson, Deanna L

2016-06-01

Dietary lipids modulate immunity, yet the means by which specific fatty acids affect infectious disease susceptibility remains unclear. Deciphering lipid-induced immunity is critical to understanding the balance required for protecting against pathogens while avoiding chronic inflammatory diseases. To understand how specific lipids alter susceptibility to enteric infection, we fed mice isocaloric, high-fat diets composed of corn oil (rich in n-6 polyunsaturated fatty acids [n-6 PUFAs]), olive oil (rich in monounsaturated fatty acids), or milk fat (rich in saturated fatty acids) with or without fish oil (rich in n-3 PUFAs). After 5 weeks of dietary intervention, mice were challenged with Citrobacter rodentium, and pathological responses were assessed. Olive oil diets resulted in little colonic pathology associated with intestinal alkaline phosphatase, a mucosal defense factor that detoxifies lipopolysaccharide. In contrast, while both corn oil and milk fat diets resulted in inflammation-induced colonic damage, only milk fat induced compensatory protective responses, including short chain fatty acid production. Fish oil combined with milk fat, unlike unsaturated lipid diets, had a protective effect associated with intestinal alkaline phosphatase activity. Overall, these results reveal that dietary lipid type, independent of the total number of calories associated with the dietary lipid, influences the susceptibility to enteric damage and the benefits of fish oil during infection. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Effect of tofacitinib on lipid levels and lipid-related parameters in patients with moderate to severe psoriasis.

PubMed

Wolk, Robert; Armstrong, Ehrin J; Hansen, Peter R; Thiers, Bruce; Lan, Shuping; Tallman, Anna M; Kaur, Mandeep; Tatulych, Svitlana

Psoriasis is a systemic inflammatory disease associated with increased cardiovascular (CV) risk and altered lipid metabolism. Tofacitinib is an oral Janus kinase inhibitor. The aim of the study was to investigate the effects of tofacitinib on traditional and nontraditional lipid parameters and CV risk markers in patients with psoriasis from a phase III study, OPT Pivotal 1. Patients with psoriasis were randomized to tofacitinib 5 or 10 mg twice daily (BID) or placebo BID. Serum samples were collected at baseline, week 4, and week 16. Analyses included serum cholesterol levels, triglycerides, lipoproteins, lipid particles, lipid-related parameters/CV risk markers, and high-density lipoprotein (HDL) function analyses. At week 16, small concurrent increases in mean low-density lipoprotein cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels were observed with tofacitinib; total cholesterol/HDL-C ratio did not change. There was no significant change in the number of small dense LDL particles, which are considered to be more atherogenic than large particles, and oxidized LDL did not increase. Paraoxonase 1 activity, linked to HDL antioxidant capacity, increased, and HDL-associated serum amyloid A, which reduces the anti-atherogenic potential of HDL, decreased. HDL capacity to promote cholesterol efflux from macrophages did not change. Lecithin-cholesterol acyltransferase activity, which is associated with reverse cholesterol transport, increased. Markers of systemic inflammation, serum amyloid A and C-reactive protein, decreased with tofacitinib. While small increases in lipid levels are observed with tofacitinib treatment in patients with psoriasis, effects on selected lipid-related parameters and other circulating CV risk biomarkers are not suggestive of an increased CV risk [NCT01276639]. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Solubilization of lipids and lipid phases by the styrene-maleic acid copolymer.

PubMed

Dominguez Pardo, Juan J; Dörr, Jonas M; Iyer, Aditya; Cox, Ruud C; Scheidelaar, Stefan; Koorengevel, Martijn C; Subramaniam, Vinod; Killian, J Antoinette

2017-01-01

A promising tool in membrane research is the use of the styrene-maleic acid (SMA) copolymer to solubilize membranes in the form of nanodiscs. Since membranes are heterogeneous in composition, it is important to know whether SMA thereby has a preference for solubilization of either specific types of lipids or specific bilayer phases. Here, we investigated this by performing partial solubilization of model membranes and analyzing the lipid composition of the solubilized fraction. We found that SMA displays no significant lipid preference in homogeneous binary lipid mixtures in the fluid phase, even when using lipids that by themselves show very different solubilization kinetics. By contrast, in heterogeneous phase-separated bilayers, SMA was found to have a strong preference for solubilization of lipids in the fluid phase as compared to those in either a gel phase or a liquid-ordered phase. Together the results suggest that (1) SMA is a reliable tool to characterize native interactions between membrane constituents, (2) any solubilization preference of SMA is not due to properties of individual lipids but rather due to properties of the membrane or membrane domains in which these lipids reside and (3) exploiting SMA resistance rather than detergent resistance may be an attractive approach for the isolation of ordered domains from biological membranes.

Incorporation of liquid lipid in lipid nanoparticles for ocular drug delivery enhancement

NASA Astrophysics Data System (ADS)

Shen, Jie; Sun, Minjie; Ping, Qineng; Ying, Zhi; Liu, Wen

2010-01-01

The present work investigates the effect of liquid lipid incorporation on the physicochemical properties and ocular drug delivery enhancement of nanostructured lipid carriers (NLCs) and attempts to elucidate in vitro and in vivo the potential of NLCs for ocular drug delivery. The CyA-loaded or fluorescein-marked nanocarriers composed of Precifac ATO 5 and Miglyol 840 (as liquid lipid) were prepared by melting-emulsion technology, and the physicochemical properties of nanocarriers were determined. The uptake of nanocarriers by human corneal epithelia cell lines (SDHCEC) and rabbit cornea was examined. Ex vivo fluorescence imaging was used to investigate the ocular distribution of nanocarriers. The in vitro cytotoxicity and in vivo acute tolerance were evaluated. The higher drug loading capacity and improved in vitro sustained drug release behavior of lipid nanoparticles was found with the incorporation of liquid lipid in lipid nanoparticles. The uptake of nanocarriers by the SDHCEC was increased with the increase in liquid lipid loading. The ex vivo fluorescence imaging of the ocular tissues indicated that the liquid lipid incorporation could improve the ocular retention and penetration of ocular therapeutics. No alternation was macroscopically observed in vivo after ocular surface exposure to nanocarriers. These results indicated that NLC was a biocompatible and potential nanocarrier for ocular drug delivery enhancement.

Solid Lipid Nanoparticles and Nanostructured Lipid Carriers: Structure, Preparation and Application

PubMed Central

Naseri, Neda; Valizadeh, Hadi; Zakeri-Milani, Parvin

2015-01-01

Lipid nanoparticles (LNPs) have attracted special interest during last few decades. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are two major types of Lipid-based nanoparticles. SLNs were developed to overcome the limitations of other colloidal carriers, such as emulsions, liposomes and polymeric nanoparticles because they have advantages like good release profile and targeted drug delivery with excellent physical stability. In the next generation of the lipid nanoparticle, NLCs are modified SLNs which improve the stability and capacity loading. Three structural models of NLCs have been proposed. These LNPs have potential applications in drug delivery field, research, cosmetics, clinical medicine, etc. This article focuses on features, structure and innovation of LNPs and presents a wide discussion about preparation methods, advantages, disadvantages and applications of LNPs by focusing on SLNs and NLCs. PMID:26504751

Computational Functional Analysis of Lipid Metabolic Enzymes.

PubMed

Bagnato, Carolina; Have, Arjen Ten; Prados, María B; Beligni, María V

2017-01-01

The computational analysis of enzymes that participate in lipid metabolism has both common and unique challenges when compared to the whole protein universe. Some of the hurdles that interfere with the functional annotation of lipid metabolic enzymes that are common to other pathways include the definition of proper starting datasets, the construction of reliable multiple sequence alignments, the definition of appropriate evolutionary models, and the reconstruction of phylogenetic trees with high statistical support, particularly for large datasets. Most enzymes that take part in lipid metabolism belong to complex superfamilies with many members that are not involved in lipid metabolism. In addition, some enzymes that do not have sequence similarity catalyze similar or even identical reactions. Some of the challenges that, albeit not unique, are more specific to lipid metabolism refer to the high compartmentalization of the routes, the catalysis in hydrophobic environments and, related to this, the function near or in biological membranes.In this work, we provide guidelines intended to assist in the proper functional annotation of lipid metabolic enzymes, based on previous experiences related to the phospholipase D superfamily and the annotation of the triglyceride synthesis pathway in algae. We describe a pipeline that starts with the definition of an initial set of sequences to be used in similarity-based searches and ends in the reconstruction of phylogenies. We also mention the main issues that have to be taken into consideration when using tools to analyze subcellular localization, hydrophobicity patterns, or presence of transmembrane domains in lipid metabolic enzymes.

Ambient and at-the-ear occupational noise exposure and serum lipid levels.

PubMed

Arlien-Søborg, Mai C; Schmedes, Astrid S; Stokholm, Z A; Grynderup, M B; Bonde, J P; Jensen, C S; Hansen, Å M; Frederiksen, T W; Kristiansen, J; Christensen, K L; Vestergaard, J M; Lund, S P; Kolstad, H A

2016-10-01

Occupational and residential noise exposure has been related to increased risk of cardiovascular disease. Alteration of serum lipid levels has been proposed as a possible causal pathway. The objective of this study was to investigate the relation between ambient and at-the-ear occupational noise exposure and serum levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides when accounting for well-established predictors of lipid levels. This cross-sectional study included 424 industrial workers and 84 financial workers to obtain contrast in noise exposure levels. They provided a serum sample and wore portable dosimeters that every 5-s recorded ambient noise exposure levels during a 24-h period. We extracted measurements obtained during work and calculated the full-shift mean ambient noise level. For 331 workers who kept a diary on the use of a hearing protection device (HPD), we subtracted 10 dB from every noise recording obtained during HPD use and estimated the mean full-shift noise exposure level at the ear. Mean ambient noise level was 79.9 dB (A) [range 55.0-98.9] and the mean estimated level at the ear 77.8 dB (A) [range 55.0-94.2]. Ambient and at-the-ear noise levels were strongly associated with increasing levels of triglycerides, cholesterol-HDL ratio, and decreasing levels of HDL-cholesterol, but only in unadjusted analyses that did not account for HPD use and other risk factors. No associations between ambient or at-the-ear occupational noise exposure and serum lipid levels were observed. This indicates that a causal pathway between occupational and residential noise exposure and cardiovascular disease does not include alteration of lipid levels.

Altered lipid and salt taste responsivity in ghrelin and GOAT null mice.

PubMed

Cai, Huan; Cong, Wei-Na; Daimon, Caitlin M; Wang, Rui; Tschöp, Matthias H; Sévigny, Jean; Martin, Bronwen; Maudsley, Stuart

2013-01-01

Taste perception plays an important role in regulating food preference, eating behavior and energy homeostasis. Taste perception is modulated by a variety of factors, including gastric hormones such as ghrelin. Ghrelin can regulate growth hormone release, food intake, adiposity, and energy metabolism. Octanoylation of ghrelin by ghrelin O-acyltransferase (GOAT) is a specific post-translational modification which is essential for many biological activities of ghrelin. Ghrelin and GOAT are both widely expressed in many organs including the gustatory system. In the current study, overall metabolic profiles were assessed in wild-type (WT), ghrelin knockout (ghrelin(-/-)), and GOAT knockout (GOAT(-/-)) mice. Ghrelin(-/-) mice exhibited decreased food intake, increased plasma triglycerides and increased ketone bodies compared to WT mice while demonstrating WT-like body weight, fat composition and glucose control. In contrast GOAT(-/-) mice exhibited reduced body weight, adiposity, resting glucose and insulin levels compared to WT mice. Brief access taste behavioral tests were performed to determine taste responsivity in WT, ghrelin(-/-) and GOAT(-/-) mice. Ghrelin and GOAT null mice possessed reduced lipid taste responsivity. Furthermore, we found that salty taste responsivity was attenuated in ghrelin(-/-) mice, yet potentiated in GOAT(-/-) mice compared to WT mice. Expression of the potential lipid taste regulators Cd36 and Gpr120 were reduced in the taste buds of ghrelin and GOAT null mice, while the salt-sensitive ENaC subunit was increased in GOAT(-/-) mice compared with WT mice. The altered expression of Cd36, Gpr120 and ENaC may be responsible for the altered lipid and salt taste perception in ghrelin(-/-) and GOAT(-/-) mice. The data presented in the current study potentially implicates ghrelin signaling activity in the modulation of both lipid and salt taste modalities.

Body Composition and Ectopic Lipid Changes With Biochemical Control of Acromegaly.

PubMed

Bredella, Miriam A; Schorr, Melanie; Dichtel, Laura E; Gerweck, Anu V; Young, Brian J; Woodmansee, Whitney W; Swearingen, Brooke; Miller, Karen K

2017-11-01

Acromegaly is characterized by growth hormone (GH) and insulinlike growth factor-1 (IGF-1) hypersecretion, and GH and IGF-1 play important roles in regulating body composition and glucose homeostasis. The purpose of our study was to investigate body composition including ectopic lipids, measures of glucose homeostasis, and gonadal steroids in patients with active acromegaly compared with age-, body mass index (BMI)-, and sex-matched controls and to determine changes in these parameters after biochemical control of acromegaly. Cross-sectional study of 20 patients with active acromegaly and 20 healthy matched controls. Prospective study of 16 patients before and after biochemical control of acromegaly. Body composition including ectopic lipids by magnetic resonance imaging/proton magnetic resonance spectroscopy; measures of glucose homeostasis by an oral glucose tolerance test; gonadal steroids. Patients with active acromegaly had lower mean intrahepatic lipid (IHL) and higher mean fasting insulin and insulin area under the curve (AUC) values than controls. Men with acromegaly had lower mean total testosterone, sex hormone-binding globulin, and estradiol values than male controls. After therapy, homeostasis model assessment of insulin resistance, fasting insulin level, and insulin AUC decreased despite an increase in IHL and abdominal and thigh adipose tissues and a decrease in muscle mass. Patients with acromegaly were characterized by insulin resistance and hyperinsulinemia but lower IHL compared with age-, BMI-, and sex-matched healthy controls. Biochemical control of acromegaly improved insulin resistance but led to a less favorable anthropometric phenotype with increased IHL and abdominal adiposity and decreased muscle mass. Copyright © 2017 Endocrine Society

Investigating the Biosynthesis of Membrane-spanning Lipids Using Model Strains of Acidobacteria

NASA Astrophysics Data System (ADS)

Bradley, A. S.; Chubiz, L. M.

2016-12-01

Glycerol dialkyl glycerol tetraethers (GDGTs), deriving from the membrane-spanning lipids of microbes, are detected in a wide range of environments including marine and lacustrine waters, sediments, and in terrestrial soils. In sediments and soils, ratios of various GDGT structures form the basis of the TEX86 proxy based on isoprenoidal GDGTs derived from archaea, and the MBT/CBT proxy based on bacterial-derived branched GDGTs (brGDGTs), which is influenced by both temperature and pH. While the relationships of the proxy values to environmental variables have been empirically calibrated, much uncertainty remains in understanding genetic and physiological factors that affect the production of these lipid structures by microbes. In this study we compare two model bacterial strains - Edaphobacter aggregans WGB-1 , which has been previously demonstrated to produce brGDGTs (Damsté et al 2011) and Edaphobacter modestus JBG-1 (a non-brGDGT producer) to gain traction into understanding brGDGT production. We have sequenced each genome, facilitating comparisons that can be used to computationally generate hypotheses for genes involved in brGDGT biosynthesis. We will also report the results of initial experiments conducted to understand how the lipid profiles of each strain vary as a function of growth phase. Through a combination of genetic approaches and physiolotical experiments, we aim to bring new understanding to brGDGTs and how proxies derived from these lipids relate to environmental variables. Damsté et al. 2011 AEM 77: 4147

pH-Cleavable Nucleoside Lipids: A New Paradigm for Controlling the Stability of Lipid-Based Delivery Systems.

PubMed

Oumzil, Khalid; Benizri, Sébastien; Tonelli, Giovanni; Staedel, Cathy; Appavoo, Ananda; Chaffanet, Max; Navailles, Laurence; Barthélémy, Philippe

2015-11-01

Lipid-based delivery systems are an established technology with considerable clinical acceptance and several applications in human. Herein, we report the design, synthesis and evaluation of novel orthoester nucleoside lipids (ONLs) for the modulation of liposome stability. The ONLs contain head groups with 3'-orthoester nucleoside derivatives featuring positive or negative charges. The insertion of the orthoester function in the NL structures allows the formation of pH-sensitive liposomes. ONL-based liposomes can be hydrolyzed to provide nontoxic products, including nucleoside derivatives and hexadecanol. To allow the release to be tunable at different hydrolysis rates, the charge of the polar head structure is modulated, and the head group can be released at a biologically relevant pH. Crucially, when ONLs are mixed with natural phosphocholine lipids (PC), the resultant liposome evolves toward the formation of a hexadecanol/PC lamellar system. Biological evaluation shows that stable nucleic acid lipid particles (SNALPs) formulated with ONLs and siRNAs can effectively enter into tumor cells and release their nucleic acid payload in response to an intracellular acidic environment. This results in a much higher antitumor activity than conventional SNALPs. The ability to use pH-cleavable nucleolipids to control the stability of lipid-based delivery systems represents a promising approach for the intracellular delivery of drug cargos. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Associations of Serum Lipids with Vitamin D Status.

PubMed

Wang, Ying; Si, Shaoyan; Liu, Junli; Wang, Zongye; Jia, Haiying; Feng, Kai; Sun, Lili; Song, Shu Jun

2016-01-01

Vitamin D deficiency has been associated with some disorders including cardiovascular diseases. Dyslipidemia is a major risk factor for cardiovascular diseases. However, data about the relationships between vitamin D and lipids are inconsistent. The relationship of vitamin D and Atherogenic Index of Plasma (AIP), as an excellent predictor of level of small and dense LDL, has not been reported. The objective of this study was to investigate the effects of vitamin D status on serum lipids in Chinese adults. The study was carried out using 1475 participants from the Center for Physical Examination, 306 Hospital of PLA in Beijing, China. Fasting blood samples were collected and serum concentrations of 25(OH)D, total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were measured. AIP was calculated based on the formula: log [TG/HDL-C]. Multiple linear regression analysis was used to estimate the associations between serum 25(OH)D and lipids. The association between the occurrences of dyslipidemias and vitamin D levels was assessed by multiple logistic regression analysis. Confounding factors, age and BMI, were used for the adjustment. The median of serum 25(OH)D concentration was 47 (27-92.25) nmol/L in all subjects. The overall percentage of 25(OH)D ≦ 50 nmol/L was 58.5% (males 54.4%, females 63.7%). The serum 25(OH)D levels were inversely associated with TG (β coefficient = -0.24, p < 0.001) and LDL-C (β coefficient = -0.34, p < 0.001) and positively associated with TC (β coefficient = 0.35, p < 0.002) in men. The associations between serum 25(OH)D and LDL-C (β coefficient = -0.25, p = 0.01) and TC (β coefficient = 0.39, p = 0.001) also existed in women. The serum 25(OH)D concentrations were negatively associated with AIP in men (r = -0.111, p < 0.01) but not in women. In addition, vitamin D deficient men had higher AIP values than vitamin D sufficient men. Furthermore, the

Invited review: The anti-inflammatory properties of dairy lipids.

PubMed

Lordan, R; Zabetakis, I

2017-06-01

Dairy product consumption is often associated with negative effects because of its naturally high levels of saturated fatty acids. However, recent research has shown that dairy lipids possess putative bioactivity against chronic inflammation. Inflammation triggers the onset of several chronic diseases, including cardiovascular disease, type 2 diabetes mellitus, obesity, and cancer. This review discusses the anti-inflammatory properties of dairy lipids found in milk, yogurt, and cheese, and it examines them in relation to their implications for human health: their protective effects and their role in pathology. We also consider the effect of lipid profile alteration in dairy products-by using ruminant dietary strategies to enrich the milk, or by lipid fortification in the products. We critically review the in vivo, in vitro, ex vivo, and epidemiological studies associated with these dairy lipids and their role in various inflammatory conditions. Finally, we discuss some suggestions for future research in the study of bioactive lipids and dairy products, with reference to the novel field of metabolomics and epidemiological studies. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.