Erabulenols, inhibitors of cholesteryl ester transfer protein produced by Penicillium sp. FO-5637. I.Production, isolation and biological properties.

PubMed

Tomoda, H; Tabata, N; Masuma, R; Si, S Y; Omura, S

1998-07-01

Penicillium sp. FO-5637, a soil isolate, was found to produce a series of inhibitors of cholesteryl ester transfer protein (CETP). Novel active compounds, designated erabulenols A and B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and HPLC. Erabulenols A and B inhibit human CETP activity with IC50 values of 47.7 and 58.2 microM in an in vitro assay system containing 200 microM BSA, respectively.

Molecular organization of the cholesteryl ester droplets in the fatty streaks of human aorta.

PubMed Central

Engelman, D M; Hillman, G M

1976-01-01

X-ray diffraction patterns from human arterial specimens containing atherosclerotic fatty streak lesions exhibited a single sharp reflection, corresponding to a structural spacing of about 35 A. Specimens without lesions did not. When specimens with fatty streaks were heated, an order-to-disorder phase transition was revealed by the disappearance of the sharp reflection. The transition was thermally reversible and its temperature varied from aorta to aorta over a range from 28 degrees to 42 degrees C. Since cholesteryl ester droplets are a major component of fatty streaks, comparison studies were made of the diffraction behavior from pure cholesteryl esters. We found that the diffraction patterns of the fatty streak material could be accounted for by the organization of the cholesteryl esters into a liquid-crystalline smectic phase that melts from the smectic to a less ordered phase upon heating. When combined with the conclusions of others from polarized light microscopy, our study shows that a droplet in the smectic phase has well-defined concentric layers of lipid molecules. In each layer, the long axes of the molecules have a net radial orientation with respect to the droplet, but the side-to-side organization is disordered. We suggest that the accessibility of portions of the lipids for specific binding to enzymes or transport proteins may be restricted when they are in the smectic state, and that exchange of lipids with surrounding membranes or other potential binding sites may likewise be inhibited. The restriction in the smectic phase should be greater than in the less ordered phases that exist at higher temperatures. Images PMID:965500

Fragment-based discovery of novel pentacyclic triterpenoid derivatives as cholesteryl ester transfer protein inhibitors.

PubMed

Chang, Yongzhi; Zhou, Shuxi; Li, Enqin; Zhao, Wenfeng; Ji, Yanpeng; Wen, Xiaoan; Sun, Hongbin; Yuan, Haoliang

2017-01-27

Cholesteryl Ester Transfer Protein (CETP) is an important therapeutic target for the treatment of atherosclerotic cardiovascular disease. Our molecular modeling study revealed that pentacyclic triterpenoid compounds could mimic the protein-ligand interactions of the endogenous ligand cholesteryl ester (CE) by occupying its binding site. Alignment of the docking conformations of oleanolic acid (OA), ursolic acid (UA) and the crystal conformations of known CETP inhibitor Torcetrapib in the active site proposed the applicability of fragment-based drug design (FBDD) approaches in this study. Accordingly, a series of pentacyclic triterpenoid derivatives have been designed and synthesized as novel CETP inhibitors. The most potent compound 12e (IC 50 :0.28 μM) validated our strategy for molecular design. Molecular dynamics simulations illustrated that the more stable hydrogen bond interaction of the UA derivative 12e with Ser191 and stronger hydrophobic interactions with Val198, Phe463 than those of OA derivative 12b mainly led to their significantly different CETP inhibitory activity. These novel potent CETP inhibitors based on ursane-type scaffold should deserve further investigation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Mechanisms of foam cell formation in atherosclerosis.

PubMed

Chistiakov, Dimitry A; Melnichenko, Alexandra A; Myasoedova, Veronika A; Grechko, Andrey V; Orekhov, Alexander N

2017-11-01

Low-density lipoprotein (LDL) and cholesterol homeostasis in the peripheral blood is maintained by specialized cells, such as macrophages. Macrophages express a variety of scavenger receptors (SR) that interact with lipoproteins, including SR-A1, CD36, and lectin-like oxLDL receptor-1 (LOX-1). These cells also have several cholesterol transporters, including ATP-binding cassette transporter ABCA1, ABCG1, and SR-BI, that are involved in reverse cholesterol transport. Lipids internalized by phagocytosis are transported to late endosomes/lysosomes, where lysosomal acid lipase (LAL) digests cholesteryl esters releasing free cholesterol. Free cholesterol in turn is processed by acetyl-CoA acetyltransferase (ACAT1), an enzyme that transforms cholesterol to cholesteryl esters. The endoplasmic reticulum serves as a depot for maintaining newly synthesized cholesteryl esters that can be processed by neutral cholesterol ester hydrolase (NCEH), which generates free cholesterol that can exit via cholesterol transporters. In atherosclerosis, pro-inflammatory stimuli upregulate expression of scavenger receptors, especially LOX-1, and downregulate expression of cholesterol transporters. ACAT1 is also increased, while NCEH expression is reduced. This results in deposition of free and esterified cholesterol in macrophages and generation of foam cells. Moreover, other cell types, such as endothelial (ECs) and vascular smooth muscle cells (VSMCs), can also become foam cells. In this review, we discuss known pathways of foam cell formation in atherosclerosis.

Plasma lipid concentrations for some Brazilian lizards.

PubMed

Gillett, M P; Lima, V L; Costa, J C; Sibrian, A M

1979-01-01

1. Plasma concentrations of cholesterol, cholesteryl esters, phospholipids and triglycerides were determined for ten species of Brazilian lizards, Iguana iguana, Tropidurus torquatos and T. semitaeniatus (Iguanidae), Tupinambis teguixin, Ameiva ameiva and Cnemidophorus ocellifer (Teiidae), Mabuya maculata (Scincidae), Hemidactylus mabouia (Gekkonidae), Amphisbaenia vermicularis and Leposternon polystegum (Amphisbaenidae). 2. Considerable inter- and intra-species variations in plasma lipid concentrations were observed. 3. The percentage of total cholesterol esterified and the individual phospholipid composition of plasma were relatively constant for each species. 4. Over 60% of the cholesteryl esters present in plasma from three species each of iguanid and teiid lizards were polyenoic.

Ezetimibe selectively inhibits intestinal cholesterol absorption in rodents in the presence and absence of exocrine pancreatic function

PubMed Central

van Heek, Margaret; Farley, Constance; Compton, Douglas S; Hoos, Lizbeth; Davis, Harry R

2001-01-01

Ezetimibe potently inhibits the transport of cholesterol across the intestinal wall, thereby reducing plasma cholesterol in preclinical animal models of hypercholesterolemia. The effect of ezetimibe on known absorptive processes was determined in the present studies.Experiments were conducted in the hamster and/or rat to determine whether ezetimibe would affect the absorption of molecules other than free cholesterol, namely cholesteryl ester, triglyceride, ethinylestradiol, progesterone, vitamins A and D, and taurocholic acid. In addition, to determine whether exocrine pancreatic function is involved in the mechanism of action of ezetimibe, a biliary anastomosis model, which eliminates exocrine pancreatic function from the intestine while maintaining bile flow, was established in the rat.Ezetimibe reduced plasma cholesterol and hepatic cholesterol accumulation in cholesterol-fed hamsters with an ED50 of 0.04 mg kg−1. Utilizing cholesteryl esters labelled on either the cholesterol or the fatty acid moiety, we demonstrated that ezetimibe did not affect cholesteryl ester hydrolysis and the absorption of fatty acid thus generated in both hamsters and rats. The free cholesterol from this hydrolysis, however, was not absorbed (92 – 96% inhibition) in the presence of ezetimibe. Eliminating pancreatic function in rats abolished hydrolysis of cholesteryl esters, but did not affect the ability of ezetimibe to block absorption of free cholesterol (−94%). Ezetimibe did not affect the absorption of triglyceride, ethinylestradiol, progesterone, vitamins A and D, and taurocholic acid in rats.Ezetimibe is a potent inhibitor of intestinal free cholesterol absorption that does not require exocrine pancreatic function for activity. Ezetimibe does not affect the absorption of triglyceride as a pancreatic lipase inhibitor (Orlistat) would, nor does it affect the absorption of vitamin A, D or taurocholate, as a bile acid sequestrant (cholestyramine) would. PMID:11564660

Mechanism of Inhibition of Cholesteryl Ester Transfer Protein by Small Molecule Inhibitors.

PubMed

Chirasani, Venkat R; Sankar, Revathi; Senapati, Sanjib

2016-08-25

Cholesteryl ester transfer protein (CETP) facilitates the bidirectional exchange of cholesteryl esters and triglycerides between high-density lipoproteins and low- or very low-density lipoproteins. Recent studies have shown that the impairment of lipid exchange processes of CETP can be an effective strategy for the treatment of cardiovascular diseases (CVDs). Understanding the molecular mechanism of CETP inhibition has, therefore, attracted tremendous attention in recent past. In this study, we explored the detailed mechanism of CETP inhibition by a series of recently reported small molecule inhibitors that are currently under preclinical testing. Our results from molecular dynamics simulations and protein-ligand docking studies suggest that the hydrophobic interactions between the CETP core tunnel residues and inhibitor moieties play a pivotal role, and physical occlusion of the CETP tunnel by these small molecules is the primary mechanism of CETP inhibition. Interestingly, bound inhibitors were found to increase the plasticity of CETP, which was explained by principal component analysis that showed a larger space of sampling of CETP C-domain due to inhibitor binding. The atomic-level details presented here could help accelerate the structure-based drug-discovery processes targeting CETP for CVD therapeutics.

Wolman disease associated with hemophagocytic lymphohistiocytosis: attempts for an explanation.

PubMed

Taurisano, Roberta; Maiorana, Arianna; De Benedetti, Fabrizio; Dionisi-Vici, Carlo; Boldrini, Renata; Deodato, Federica

2014-10-01

The lysosomal acid lipase (LAL) is the enzyme responsible of the hydrolysis of cholesteryl esters and triglycerides within endo-lysosomes. Loss of enzyme activity leads to accumulation of cholesteryl esters and triglycerides in the lysosome of most tissues. The complete deficiency of LAL is responsible of Wolman disease (WD), a severe systemic disease manifesting in the first days of life with vomiting, diarrhea, failure to thrive, hepatosplenomegaly, jaundice, anemia, and thrombocytopenia. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition which may be genetically determined or secondary to infections, malignancies, immune deficiencies, and rheumatologic disorders. So far, some inborn errors of metabolism have been associated with HLH (e.g., lysinuric protein intolerance, Gaucher's disease), and it has been anecdotally described in three WD patients, without any specific pathogenetic hypothesis. Here, we report on a WD patient, showing clear clinical, biochemical, and histological features indicative of HLH. We discuss the pathophysiological role of cholesteryl ester-induced inflammasome activation in macrophages, leading to a secondary HLH. This case indicates that WD can cause secondary HLH and suggests that a careful metabolic workup should be performed when facing to a pediatric patient with HLH.

Açai (Euterpe oleracea Mart.) dietary intake affects plasma lipids, apolipoproteins, cholesteryl ester transfer to high-density lipoprotein and redox metabolism: A prospective study in women.

PubMed

Pala, Daniela; Barbosa, Priscila Oliveira; Silva, Carla Teixeira; de Souza, Melina Oliveira; Freitas, Fatima Rodrigues; Volp, Ana Carolina Pinheiro; Maranhão, Raul Cavalcante; Freitas, Renata Nascimento de

2018-04-01

The açai fruit (Euterpe oleracea Martius), which is native to the Brazilian Amazon region, was shown to have high polyphenols and MUFA contents. In this study, we aimed to assess the effects of açai consumption on plasma lipids, apolipoproteins, the transfer of lipids to HDL (which is a relevant HDL function), and some biomarkers of redox metabolism. Forty healthy volunteer women aged 24 ± 3 years consumed 200 g of açai pulp/day for 4 weeks; their clinical variables and blood sample were obtained before and after this period. Açai pulp consumption did not alter anthropometric parameters, systemic arterial pressure, glucose, insulin and total, LDL and HDL cholesterol, triglycerides and apolipoprotein (apo) B, but it did increase the concentration of apo A-I. Açai consumption decreased the ROS, ox-LDL and malondialdehyde while increasing the activity of antioxidative paraoxonase 1. Overall, the total antioxidant capacity (TAC) was increased. Regarding the transfer of plasma lipids to HDL, açai consumption increased the transfer of cholesteryl esters (p = 0.0043) to HDL. Unesterified cholesterol, phospholipids and triglyceride transfers were unaffected. The increase in apo A-I and the cholesteryl ester transfer to HDL after the açai intake period suggests that an improvement in the metabolism of this lipoprotein occurred, and it is well known that HDL is protective against atherosclerosis. Another important finding was the general improvement of the anti-oxidant defences elicited by açai consumption. Our data indicate that açai has favourable actions on plasma HDL metabolism and anti-oxidant defence; therefore açai could have a beneficial overall role against atherosclerosis, and it is a consistently good candidate to consider as a functional food. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Chemical differences are observed in children's versus adults' latent fingerprints as a function of time.

PubMed

Antoine, Kimone M; Mortazavi, Shirin; Miller, Angela D; Miller, Lisa M

2010-03-01

The identification of aged latent fingerprints is often difficult, especially for those of children. To understand this phenomenon, the chemical composition of children's versus adults' latent fingerprints was examined over time using Fourier transform infrared microscopy. Hierarchical cluster analysis revealed that children's and adults' prints were distinguishable for up to 4 weeks after deposition, based on differences in sebum composition. Specifically, adults had a higher lipid content than children, but both decreased over time, attributable to the volatility of free fatty acids. The aliphatic CH(3), aliphatic CH(2), and carbonyl ester compositions changed differently in adults versus children over time, consistent with higher cholesterol and cholesteryl esters in children's prints and wax esters and glycerides in adults' prints. Thus, fingerprint composition changes with time differently in children versus adults, making it a sensitive metric to estimate the age of an individual, especially when the age of the print is known.

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

Antoine, K.M.; Miller, L.; Mortazavi, S.

The identification of aged latent fingerprints is often difficult, especially for those of children. To understand this phenomenon, the chemical composition of children's versus adults latent fingerprints was examined over time using Fourier transform infrared microscopy. Hierarchical cluster analysis revealed that children's and adults prints were distinguishable for up to 4 weeks after deposition, based on differences in sebum composition. Specifically, adults had a higher lipid content than children, but both decreased over time, attributable to the volatility of free fatty acids. The aliphatic CH{sub 3}, aliphatic CH{sub 2}, and carbonyl ester compositions changed differently in adults versus children overmore » time, consistent with higher cholesterol and cholesteryl esters in children's prints and wax esters and glycerides in adults prints. Thus, fingerprint composition changes with time differently in children versus adults, making it a sensitive metric to estimate the age of an individual, especially when the age of the print is known.« less

HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

PubMed Central

Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

2015-01-01

Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL. PMID:25737239

HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

DOE PAGES

Zhang, Meng; Charles, River; Tong, Huimin; ...

2015-03-04

Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore » environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less

HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

2015-03-01

Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.

Radioiodinated cholesteryl ester analogs as residualizing tracers of lipoproteins disposition

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

DeForge, L.E.

1989-01-01

Due to the importance of low density lipoprotein (LDL) in lipid metabolism and atherosclerosis, efforts were made to incorporate {sup 125}I-cholesteryl iopanoate ({sup 125}I-CI), a residualizing cholesteryl ester (CE) analog, into the lipid core of LDL. This preparation is potentially useful as a scintigraphically detectable tracer of LDL uptake into atheroma and tissues such as the adrenal and liver. Initial studies using a cholesterol-fed rabbit model of atherosclerosis validated the use of {sup 125}I-CI as a tracer of CE deposition. However, scintigraphy revealed considerable nonspecific {sup 125}I-CI uptake due to tissue cholesterol loading. An alternative animal model was the guineamore » pig, which responds moderately to cholesterol feeding and carries the plasma cholesterol predominantly as LDL. Dietary fat and cholesterol, coupled with chronic aortic injury caused by an indwelling catheter, resulted in lipid containing, smooth muscle cell proliferative lesions in many animals. However, further studies are necessary to fully characterize this model. In additional studies, in vitro methods for incorporating {sup 125}I-CI into LDL were examined. These included a reconstitution procedure described by Krieger et al. and a procedure involving incubation of detergent (Tween 20)-solubilized {sup 125}I-CI with plasma. Although both LDL preparations were taken up normally by cultured fibroblasts, the plasma clearance rate of reconstituted LDL was markedly abnormal in guinea pigs. In contrast, LDL labeled by the detergent method cleared from the plasma identically to a radioiodinated LDL control. Therefore, this latter procedure was also used to incorporate two novel radioiodinated cholesteryl ether analogs {sup 125}I-CI cholesteryl m-iodobenzyl ether ({sup 125}I-CIDE) and {sup 125}I-cholesteryl 12-(miodophenyl)dodecyl ether ({sup 125}I-CIDE) into LDL.« less

Cholesteryl ester transfer protein inhibition as a strategy to reduce cardiovascular risk

PubMed Central

Barter, Philip J.; Rye, Kerry-Anne

2012-01-01

Human and rabbit plasma contain a cholesteryl ester transfer protein (CETP) that promotes net mass transfers of cholesteryl esters from high density lipoproteins (HDL) to other plasma lipoprotein fractions. As predicted, inhibition of CETP in both humans and rabbits increases the concentration of cholesterol in the potentially protective HDL fraction, while decreasing it in potentially proatherogenic non-HDL fractions. Inhibition of CETP in rabbits also inhibits the development of diet-induced atherosclerosis. However, use of the CETP inhibitor torcetrapib in humans did not reduce atheroma in three imaging trials and caused an excess of deaths and cardiovascular events in a large clinical outcome trial. The precise explanation for the harm caused by torcetrapib is unknown but may relate to documented, potentially harmful effects unrelated to inhibition of CETP. More recently, a trial using the weak CETP inhibitor dalcetrapib, which raises HDL levels less effectively than torcetrapib and does not lower non-HDL lipoprotein levels, was terminated early for reasons of futility. There was no evidence that dalcetrapib caused harm in that trial. Despite these setbacks, the hypothesis that CETP inhibitors will be antiatherogenic in humans is still being tested in studies with anacetrapib and evacetrapib, two CETP inhibitors that are much more potent than dalcetrapib and that do not share the off-target adverse effects of torcetrapib. PMID:22550134

Bolstering cholesteryl ester hydrolysis in liver: A hepatocyte-targeting gene delivery strategy for potential alleviation of atherosclerosis

PubMed Central

He, Hongliang; Lancina, Michael G.; Wang, Jing; Korzun, William J.; Yang, Hu; Ghosh, Shobha

2017-01-01

Current atherosclerosis treatment strategies primarily focus on limiting further cholesteryl esters (CE) accumulation by reducing endogenous synthesis of cholesterol in the liver. No therapy is currently available to enhance the removal of CE, a crucial step to reduce the burden of the existing disease. Given a central role of hepatic cholesteryl ester hydrolase (CEH) in intrahepatic hydrolysis of CE and subsequent removal of the resulting free cholesterol, in this work, we applied galactose-functionalized polyamidoamine (PAMAM) dendrimer G5 (Gal-G5) for hepatocyte-specific delivery of CEH expression vector. The data presented herein show increased specific uptake of Gal-G5 by the hepatocytes in vitro and in vivo. Furthermore, the upregulated CEH expression in the hepatocytes significantly enhanced intracellular hydrolysis of HDL-CE and subsequent conversion/secretion of hydrolyzed free cholesterol (FC) as bile acids. Increased CEH expression in the liver significantly increased the flux of HDL-CE to biliary as well as fecal FC and bile acids. Meanwhile, Gal-G5 did not induce hepatic or renal toxicity. It was not immunotoxic. Because of these encouraging pre-clinical testing results, using this safe and highly efficient hepatocyte-specific gene delivery platform to enhance the hepatic processes involved in cholesterol elimination is a promising strategy for alleviation of atherosclerosis. PMID:28349866

Comparative studies of three cholesteryl ester transfer proteins and their interactions with known inhibitors

PubMed Central

Wang, Ziyun; Niimi, Manabu; Ding, Qianzhi; Liu, Zhenming; Wang, Ling; Zhang, Jifeng; Xu, Jun

2017-01-01

Cholesteryl ester transfer protein (CETP) is a plasma protein that mediates bidirectional transfers of cholesteryl esters and triglycerides between low-density lipoproteins and high-density lipoproteins (HDL). Because low levels of plasma CETP are associated with increased plasma HDL-cholesterol, therapeutic inhibition of CETP activity is considered an attractive strategy for elevating plasma HDL-cholesterol, thereby hoping to reduce the risk of cardiovascular disease. Interestingly, only a few laboratory animals, such as rabbits, guinea pigs, and hamsters, have plasma CETP activity, whereas mice and rats do not. It is not known whether all CETPs in these laboratory animals are functionally similar to human CETP. In the current study, we compared plasma CETP activity and characterized the plasma lipoprotein profiles of these animals. Furthermore, we studied the three CETP molecular structures, physicochemical characteristics, and binding properties with known CETP inhibitors in silico. Our results showed that rabbits exhibited higher CETP activity than guinea pigs and hamsters, while these animals had different lipoprotein profiles. CETP inhibitors can inhibit rabbit and hamster CETP activity in a similar manner to human CETP. Analysis of CETP molecules in silico revealed that rabbit and hamster CETP showed many features that are similar to human CETP. These results provide novel insights into understanding CETP functions and molecular properties. PMID:28767652

Insights into the Tunnel Mechanism of Cholesteryl Ester Transfer Protein through All-atom Molecular Dynamics Simulations

DOE PAGES

Lei, Dongsheng; Rames, Matthew; Zhang, Xing; ...

2016-05-03

Cholesteryl ester transfer protein (CETP) mediates cholesteryl ester (CE) transfer from the atheroprotective high density lipoprotein (HDL) cholesterol to the atherogenic low density lipoprotein cholesterol. In the past decade, this property has driven the development of CETP inhibitors, which have been evaluated in large scale clinical trials for treating cardiovascular diseases. Despite the pharmacological interest, little is known about the fundamental mechanism of CETP in CE transfer. Recent electron microscopy (EM) experiments have suggested a tunnel mechanism, and molecular dynamics simulations have shown that the flexible N-terminal distal end of CETP penetrates into the HDL surface and takes up amore » CE molecule through an open pore. However, it is not known whether a CE molecule can completely transfer through an entire CETP molecule. Here, we used all-atom molecular dynamics simulations to evaluate this possibility. The results showed that a hydrophobic tunnel inside CETP is sufficient to allow a CE molecule to completely transfer through the entire CETP within a predicted transfer time and at a rate comparable with those obtained through physiological measurements. Analyses of the detailed interactions revealed several residues that might be critical for CETP function, which may provide important clues for the effective development of CETP inhibitors and treatment of cardiovascular diseases.« less

Regulation of Hepatic Cholesteryl Ester Transfer Protein Expression and Reverse Cholesterol Transport by Inhibition of DNA Topoisomerase II.

PubMed

Liu, Mengyang; Chen, Yuanli; Zhang, Ling; Wang, Qixue; Ma, Xingzhe; Li, Xiaoju; Xiang, Rong; Zhu, Yan; Qin, Shucun; Yu, Yang; Jiang, Xian-cheng; Duan, Yajun; Han, Jihong

2015-06-05

Cholesteryl ester transfer protein (CETP) transfers cholesteryl esters from high density lipoprotein to triglyceride-rich lipoproteins. CETP expression can be transcriptionally activated by liver X receptor (LXR). Etoposide and teniposide are DNA topoisomerase II (Topo II) inhibitors. Etoposide has been reported to inhibit atherosclerosis in rabbits with un-fully elucidated mechanisms. In this study we determined if Topo II activity can influence cholesterol metabolism by regulating hepatic CETP expression. Inhibition of Topo II by etoposide, teniposide, or Topo II siRNA increased CETP expression in human hepatic cell line, HepG2 cells, which was associated with increased CETP secretion and mRNA expression. Meanwhile, inhibition of LXR expression by LXR siRNA attenuated induction of CETP expression by etoposide and teniposide. Etoposide and teniposide induced LXRα expression and LXRα/β nuclear translocation while inhibiting expression of receptor interacting protein 140 (RIP140), an LXR co-repressor. In vivo, administration of teniposide moderately reduced serum lipid profiles, induced CETP expression in the liver, and activated reverse cholesterol transport in CETP transgenic mice. Our study demonstrates a novel function of Topo II inhibitors in cholesterol metabolism by activating hepatic CETP expression and reverse cholesterol transport. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Reduction of In-Stent Restenosis by Cholesteryl Ester Transfer Protein Inhibition.

PubMed

Wu, Ben J; Li, Yue; Ong, Kwok L; Sun, Yidan; Shrestha, Sudichhya; Hou, Liming; Johns, Douglas; Barter, Philip J; Rye, Kerry-Anne

2017-12-01

Angioplasty and stent implantation, the most common treatment for atherosclerotic lesions, have a significant failure rate because of restenosis. This study asks whether increasing plasma high-density lipoprotein (HDL) levels by inhibiting cholesteryl ester transfer protein activity with the anacetrapib analog, des-fluoro-anacetrapib, prevents stent-induced neointimal hyperplasia. New Zealand White rabbits received normal chow or chow supplemented with 0.14% (wt/wt) des-fluoro-anacetrapib for 6 weeks. Iliac artery endothelial denudation and bare metal steel stent deployment were performed after 2 weeks of des-fluoro-anacetrapib treatment. The animals were euthanized 4 weeks poststent deployment. Relative to control, dietary supplementation with des-fluoro-anacetrapib reduced plasma cholesteryl ester transfer protein activity and increased plasma apolipoprotein A-I and HDL cholesterol levels by 53±6.3% and 120±19%, respectively. Non-HDL cholesterol levels were unaffected. Des-fluoro-anacetrapib treatment reduced the intimal area of the stented arteries by 43±5.6% ( P <0.001), the media area was unchanged, and the arterial lumen area increased by 12±2.4% ( P <0.05). Des-fluoro-anacetrapib treatment inhibited vascular smooth muscle cell proliferation by 41±4.5% ( P <0.001). Incubation of isolated HDLs from des-fluoro-anacetrapib-treated animals with human aortic smooth muscle cells at apolipoprotein A-I concentrations comparable to their plasma levels inhibited cell proliferation and migration. These effects were dependent on scavenger receptor-B1, the adaptor protein PDZ domain-containing protein 1, and phosphatidylinositol-3-kinase/Akt activation. HDLs from des-fluoro-anacetrapib-treated animals also inhibited proinflammatory cytokine-induced human aortic smooth muscle cell proliferation and stent-induced vascular inflammation. Inhibiting cholesteryl ester transfer protein activity in New Zealand White rabbits with iliac artery balloon injury and stent deployment increases HDL levels, inhibits vascular smooth muscle cell proliferation, and reduces neointimal hyperplasia in an scavenger receptor-B1, PDZ domain-containing protein 1- and phosphatidylinositol-3-kinase/Akt-dependent manner. © 2017 American Heart Association, Inc.

Synthesis and Biological Evaluation of Ginsenoside Compound K Derivatives as a Novel Class of LXRα Activator.

PubMed

Huang, Yan; Liu, Hongmei; Zhang, Yingxian; Li, Jin; Wang, Chenping; Zhou, Li; Jia, Yi; Li, Xiaohui

2017-07-24

Compound K is one of the active metabolites of Panaxnotoginseng saponins, which could attenuate the formation of atherosclerosis in mice modelsvia activating LXRα. We synthesized and evaluated a series of ginsenoside compound K derivatives modified with short chain fatty acids. All of the structures of this class of ginsenoside compound K derivative exhibited comparable or better biological activity than ginsenoside compound K. Especially structure 1 exhibited the best potency (cholesteryl ester content: 41.51%; expression of ABCA1 mRNA: 319%) and low cytotoxicity.

Wolman's disease and cholesteryl ester storage disorder: the phenotypic spectrum of lysosomal acid lipase deficiency.

PubMed

Pericleous, Marinos; Kelly, Claire; Wang, Tim; Livingstone, Callum; Ala, Aftab

2017-09-01

Lysosomal acid lipase deficiency is a rare, autosomal recessive condition caused by mutations in the gene encoding lysosomal acid lipase (LIPA) that result in reduced or absent activity of this essential enzyme. The severity of the resulting disease depends on the nature of the underlying mutation and magnitude of its effect on enzymatic function. Wolman's disease is a severe disorder that presents during infancy, resulting in failure to thrive, hepatomegaly, and hepatic failure, and an average life expectancy of less than 4 months. Cholesteryl ester storage disorder arises later in life and is less severe, although the two diseases share many common features, including dyslipidaemia and transaminitis. The prevalence of these diseases has been estimated at one in 40 000 to 300 000, but many cases are undiagnosed and unreported, and awareness among clinicians is low. Lysosomal acid lipase deficiency-which can be diagnosed using dry blood spot testing-is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), hereditary dyslipidaemia, or cryptogenic cirrhosis. There are no formal guidelines for treatment of these patients, and treatment options are limited. In this Review we appraise the existing literature on Wolman's disease and cholesteryl ester storage disease, and discuss available treatments, including enzyme replacement therapy, oral lipid-lowering therapy, stem-cell transplantation, and liver transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Direct isolation of labeled low density lipoproteins for the determination of cholesteryl ester transfer protein activity.

PubMed

Sich, D; Saïdi, Y; Egloff, M; Giral, P; Gautier, V; Federspiel, M C; Turpin, G; Beucler, I

1997-10-31

The measurement of the activity of cholesteryl ester transfer protein (CETP), is of high clinical interest and this study reports the use of a direct LDL isolation (d-LDL) technique to determine in one step the amount of radiolabeled cholesteryls esters ([3H]-CE) transferred from exogenous HDL3 to LDL, avoiding the conveniences of the usually used ultracentrifugation or precipitation of apo-B containing lipoproteins in the CETP methodologies. The d-LDL technique providing a specific immunoprecipitation of VLDL, IDL and HDL allowed to directly determine the [3H]-CE transferred on LDL (d-[3H]-CE-LDL). Two methodologies were assayed for the CETP activity using either exogenous or endogenous lipoproteins, and the results with the d-LDL technique were compared with those obtained using the ultracentrifugation (u-[3H]-CE-LDL) considered as the reference method. The intra- and inter-assays were similar in both techniques for the two CETP activity assays. Strong positive correlations were established between values obtained with d-[3H]-CE-LDL and u-[3H]-CE-LDL isolation procedures for CETP activities with exogenous or endogenous lipoproteins (r = 0.972; p = 0.0001 and r = 0.965; p = 0.0001 respectively). In conclusion, the d-LDL technique represents an easy and accurate procedure to measure directly, in normotriglyceridemic plasmas, the amount of [3H]-CE transferred from HDL to LDL by the CETP.

In situ localization of the genetic locus encoding the lysosomal acid lipase/cholesteryl esterase (LIPA) deficient in wolman disease to chromosome 10q23. 2-q23. 3

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

Anderson, R.A.; Rao, N.; Byrum, R.S.

1993-01-01

Human acid lipase/cholesteryl esterase (EC 3.1.1.13) is a 46-kDa glycoprotein required for the lysosomal hydrolysis of cholesteryl esters and triglycerides that cells acquire through the receptor-mediated endocytosis of low-density lipoproteins. This activity is essential in the provision of free cholesterol for cell metabolism as well as for the feedback signal that modulates endogenous cellular cholesterol production. The extremely low level of lysosomal acid lipase in patients afflicted with the hereditary, allelic lysosomal storage disorders Woman disease (WD) and cholesteryl ester storage disease (CESD) (MIM Number 278000 (6)) is associated with the massive intralysosomal lipid storage and derangements in the regulationmore » of cellular cholesterol production (10). Both WD and CESD cells lack a specific acid lipase isoenzyme and it is thought that the different mutations associated with WD and CESD are in the structural gene for this isoenzyme, LIPA. Analysis of the activity of the acid lipase isoenzyme in cell extracts from human-Chinese hamster somatic cell hybrids (4, 11) demonstrated the concordant segregation of the gene locus for lysosomal acid lipase with the glutamate oxaloacetate transaminase-1 (GOT1) enzyme marker for human chromosome 10 which was subsequently localized to 10q24.1 q25.1 (8). 11 refs., 1 figs.« less

Deficiency of Cholesteryl Ester Transfer Protein Protects Against Atherosclerosis in Rabbits.

PubMed

Zhang, Jifeng; Niimi, Manabu; Yang, Dongshan; Liang, Jingyan; Xu, Jie; Kimura, Tokuhide; Mathew, Anna V; Guo, Yanhong; Fan, Yanbo; Zhu, Tianqing; Song, Jun; Ackermann, Rose; Koike, Yui; Schwendeman, Anna; Lai, Liangxue; Pennathur, Subramaniam; Garcia-Barrio, Minerva; Fan, Jianglin; Chen, Y Eugene

2017-06-01

CETP (cholesteryl ester transfer protein) plays an important role in lipoprotein metabolism; however, whether inhibition of CETP activity can prevent cardiovascular disease remains controversial. We generated CETP knockout (KO) rabbits by zinc finger nuclease gene editing and compared their susceptibility to cholesterol diet-induced atherosclerosis to that of wild-type (WT) rabbits. On a chow diet, KO rabbits showed higher plasma levels of high-density lipoprotein (HDL) cholesterol than WT controls, and HDL particles of KO rabbits were essentially rich in apolipoprotein AI and apolipoprotein E contents. When challenged with a cholesterol-rich diet for 18 weeks, KO rabbits not only had higher HDL cholesterol levels but also lower total cholesterol levels than WT rabbits. Analysis of plasma lipoproteins revealed that reduced plasma total cholesterol in KO rabbits was attributable to decreased apolipoprotein B-containing particles, while HDLs remained higher than that in WT rabbits. Both aortic and coronary atherosclerosis was significantly reduced in KO rabbits compared with WT rabbits. Apolipoprotein B-depleted plasma isolated from CETP KO rabbits showed significantly higher capacity for cholesterol efflux from macrophages than that from WT rabbits. Furthermore, HDLs isolated from CETP KO rabbits suppressed tumor necrosis factor-α-induced vascular cell adhesion molecule 1 and E-selectin expression in cultured endothelial cells. These results provide evidence that genetic ablation of CETP activity protects against cholesterol diet-induced atherosclerosis in rabbits. © 2017 American Heart Association, Inc.

Cholesteryl ester transfer protein inhibition enhances endothelial repair and improves endothelial function in the rabbit.

PubMed

Wu, Ben J; Shrestha, Sudichhya; Ong, Kwok L; Johns, Douglas; Hou, Liming; Barter, Philip J; Rye, Kerry-Anne

2015-03-01

High-density lipoproteins (HDLs) can potentially protect against atherosclerosis by multiple mechanisms, including enhancement of endothelial repair and improvement of endothelial function. This study asks if increasing HDL levels by inhibiting cholesteryl ester transfer protein activity with the anacetrapib analog, des-fluoro-anacetrapib, enhances endothelial repair and improves endothelial function in New Zealand White rabbits with balloon injury of the abdominal aorta. New Zealand White rabbits received chow or chow supplemented with 0.07% or 0.14% (wt/wt) des-fluoro-anacetrapib for 8 weeks. Endothelial denudation of the abdominal aorta was carried out after 2 weeks. The animals were euthanized 6 weeks postinjury. Treatment with 0.07% and 0.14% des-fluoro-anacetrapib reduced cholesteryl ester transfer protein activity by 81±4.9% and 92±12%, increased plasma apolipoprotein A-I levels by 1.4±0.1-fold and 1.5±0.1-fold, increased plasma HDL-cholesterol levels by 1.8±0.2-fold and 1.9±0.1-fold, reduced intimal hyperplasia by 37±11% and 51±10%, and inhibited vascular cell proliferation by 25±6.1% and 35±6.7%, respectively. Re-endothelialization of the injured aorta increased from 43±6.7% (control) to 69±6.6% and 76±7.7% in the 0.07% and 0.14% des-fluoro-anacetrapib-treated animals, respectively. Aortic ring relaxation and guanosine 3',5'-cyclic monophosphate production in response to acetylcholine were also improved. Incubation of HDLs from the des-fluoro-anacetrapib-treated animals with human coronary artery endothelial cells increased cell proliferation and migration relative to control. These effects were abolished by knockdown of scavenger receptor-B1 and PDZ domain-containing protein 1 and by pharmacological inhibition of phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt. Increasing HDL levels by inhibiting cholesteryl ester transfer protein reduces intimal thickening and regenerates functional endothelium in damaged New Zealand White rabbit aortas in an scavenger receptor-B1-dependent and phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt-dependent manner. © 2015 American Heart Association, Inc.

Bolstering cholesteryl ester hydrolysis in liver: A hepatocyte-targeting gene delivery strategy for potential alleviation of atherosclerosis.

PubMed

He, Hongliang; Lancina, Michael G; Wang, Jing; Korzun, William J; Yang, Hu; Ghosh, Shobha

2017-06-01

Current atherosclerosis treatment strategies primarily focus on limiting further cholesteryl esters (CE) accumulation by reducing endogenous synthesis of cholesterol in the liver. No therapy is currently available to enhance the removal of CE, a crucial step to reduce the burden of the existing disease. Given the central role of hepatic cholesteryl ester hydrolase (CEH) in the intrahepatic hydrolysis of CE and subsequent removal of the resulting free cholesterol (FC), in this work, we applied galactose-functionalized polyamidoamine (PAMAM) dendrimer generation 5 (Gal-G5) for hepatocyte-specific delivery of CEH expression vector. The data presented herein show the increased specific uptake of Gal-G5/CEH expression vector complexes (simply Gal-G5/CEH) by hepatocytes in vitro and in vivo. Furthermore, the upregulated CEH expression in the hepatocytes significantly enhanced the intracellular hydrolysis of high density lipoprotein-associated CE (HDL-CE) and subsequent conversion/secretion of hydrolyzed FC as bile acids (BA). The increased CEH expression in the liver significantly increased the flux of HDL-CE to biliary as well as fecal FC and BA. Meanwhile, Gal-G5 did not induce hepatic or renal toxicity. It was also not immunotoxic. Because of these encouraging pre-clinical testing results, using this safe and highly efficient hepatocyte-specific gene delivery platform to enhance the hepatic processes involved in cholesterol elimination is a promising strategy for the alleviation of atherosclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

CRISPR/Cas9-Mediated Gene Editing in Human iPSC-Derived Macrophage Reveals Lysosomal Acid Lipase Function in Human Macrophages-Brief Report.

PubMed

Zhang, Hanrui; Shi, Jianting; Hachet, Melanie A; Xue, Chenyi; Bauer, Robert C; Jiang, Hongfeng; Li, Wenjun; Tohyama, Junichiro; Millar, John; Billheimer, Jeffrey; Phillips, Michael C; Razani, Babak; Rader, Daniel J; Reilly, Muredach P

2017-11-01

To gain mechanistic insights into the role of LIPA (lipase A), the gene encoding LAL (lysosomal acid lipase) protein, in human macrophages. We used CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) technology to knock out LIPA in human induced pluripotent stem cells and then differentiate to macrophage (human-induced pluripotent stem cells-derived macrophage [IPSDM]) to explore the human macrophage LIPA loss-of-function phenotypes. LIPA was abundantly expressed in monocyte-derived macrophages and was markedly induced on IPSDM differentiation to comparable levels as in human monocyte-derived macrophage. IPSDM with knockout of LIPA ( LIPA -/- ) had barely detectable LAL enzymatic activity. Control and LIPA -/- IPSDM were loaded with [ 3 H]-cholesteryl oleate-labeled AcLDL (acetylated low-density lipoprotein) followed by efflux to apolipoprotein A-I. Efflux of liberated [ 3 H]-cholesterol to apolipoprotein A-I was abolished in LIPA -/- IPSDM, indicating deficiency in LAL-mediated lysosomal cholesteryl ester hydrolysis. In cells loaded with [ 3 H]-cholesterol-labeled AcLDL, [ 3 H]-cholesterol efflux was, however, not different between control and LIPA -/- IPSDM. ABCA1 (ATP-binding cassette, subfamily A, member 1) expression was upregulated by AcLDL loading but to a similar extent between control and LIPA -/- IPSDM. In nonlipid loaded state, LIPA -/- IPSDM had high levels of cholesteryl ester mass compared with minute amounts in control IPSDM. Yet, with AcLDL loading, overall cholesteryl ester mass was increased to similar levels in both control and LIPA -/- IPSDM. LIPA -/- did not impact lysosomal apolipoprotein-B degradation or expression of IL1B , IL6 , and CCL5. CONCLUSIONS: LIPA -/- IPSDM reveals macrophage-specific hallmarks of LIPA deficiency. CRISPR/Cas9 and IPSDM provide important tools to study human macrophage biology and more broadly for future studies of disease-associated LIPA genetic variation in human macrophages. © 2017 American Heart Association, Inc.

Metabolism of triglyceride-rich lipoproteins and transfer of lipids to high-density lipoproteins (HDL) in vegan and omnivore subjects.

PubMed

Vinagre, J C; Vinagre, C G; Pozzi, F S; Slywitch, E; Maranhão, R C

2013-01-01

Vegan diet excludes all foodstuffs of animal origin and leads to cholesterol lowering and possibly reduction of cardiovascular disease risk. The aim was to investigate whether vegan diet improves the metabolic pathway of triglyceride-rich lipoproteins, consisting in lipoprotein lipolysis and removal from circulation of the resulting remnants and to verify whether the diet alters HDL metabolism by changing lipid transfers to this lipoprotein. 21 vegan and 29 omnivores eutrophic and normolipidemic subjects were intravenously injected triglyceride-rich emulsions labeled with (14)C-cholesterol oleate and (3)H-triolein: fractional clearance rates (FCR, in min(-1)) were calculated from samples collected during 60 min for radioactive counting. Lipid transfer to HDL was assayed by incubating plasma samples with a donor nanoemulsion labeled with radioactive lipids; % lipids transferred to HDL were quantified in supernatant after chemical precipitation of non-HDL fractions and nanoemulsion. Serum LDL cholesterol was lower in vegans than in omnivores (2.1 ± 0.8, 2.7 ± 0.7 mmol/L, respectively, p < 0,05), but HDL cholesterol and triglycerides were equal. Cholesteryl ester FCR was greater in vegans than in omnivores (0.016 ± 0.012, 0.003 ± 0.003, p < 0.01), whereas triglyceride FCR was equal (0.024 ± 0.014, 0.030 ± 0.016, N.S.). Cholesteryl ester transfer to HDL was lower in vegans than in omnivores (2.7 ± 0.6, 3.5 ± 1.5%, p < 0,05). Free-cholesterol, triglyceride and phospholipid transfer were equal, as well as HDL size. Remnant removal from circulation, estimated by cholesteryl oleate FCR was faster in vegans, but the lipolysis process, estimated by triglyceride FCR was equal. Increased removal of atherogenic remnants and diminution of cholesteryl ester transfer may favor atherosclerosis prevention by vegan diet. Copyright © 2011 Elsevier B.V. All rights reserved.

Thermally controllable reflective characteristics from rupture and self-assembly of hydrogen bonds in cholesteric liquid crystals.

PubMed

Hu, Wang; Cao, Hui; Song, Li; Zhao, Haiyan; Li, Sijin; Yang, Zhou; Yang, Huai

2009-10-22

A cholesteric liquid crystal (Ch-LC) composite, made of a series of cholesteryl esters, a nematic LC, and a hydrogen bond (H-bond) chiral dopant (HCD), was prepared and filled into a planar treated cell. When the cell was heated, the selective reflection of the cell exhibited an unusual blue shift. One of the reasonable mechanisms was that the helical twisting power (HTP) value of cholesteryl esters increased with an increasing temperature. The other one was that the H-bonds of HCD were ruptured when the temperature was above 60.0 degrees C and HCD was split into two kinds of new chiral dopants, which made the HTP value of the chiral dopants change a lot, thus changing the pitch length of the composite greatly. On the basis of this mechanism, a novel thermally controllable reflective color paper could be achieved.

Antisense oligonucleotide inhibition of cholesteryl ester transfer protein enhances RCT in hyperlipidemic, CETP transgenic, LDLr-/- mice.

PubMed

Bell, Thomas A; Graham, Mark J; Lee, Richard G; Mullick, Adam E; Fu, Wuxia; Norris, Dan; Crooke, Rosanne M

2013-10-01

Due to their ability to promote positive effects across all of the lipoprotein classes, cholesteryl ester transfer protein (CETP) inhibitors are currently being developed as therapeutic agents for cardiovascular disease. In these studies, we compared an antisense oligonucleotide (ASO) inhibitor of CETP to the CETP small molecule inhibitor anacetrapib. In hyperlipidemic CETP transgenic (tg) mice, both drugs provided comparable reductions in total plasma cholesterol, decreases in CETP activity, and increases in HDL cholesterol. However, only mice treated with the antisense inhibitor showed an enhanced effect on macrophage reverse cholesterol transport, presumably due to differences in HDL apolipoprotein composition and decreases in plasma triglyceride. Additionally, the ASO-mediated reductions in CETP mRNA were associated with less accumulation of aortic cholesterol. These preliminary findings suggest that CETP ASOs may represent an alternative means to inhibit that target and to support their continued development as a treatment for cardiovascular disease in man.

Obesity and altered glucose metabolism impact HDL composition in CETP transgenic mice: a role for ovarian hormones[S

PubMed Central

Martinez, Melissa N.; Emfinger, Christopher H.; Overton, Matthew; Hill, Salisha; Ramaswamy, Tara S.; Cappel, David A.; Wu, Ke; Fazio, Sergio; McDonald, W. Hayes; Hachey, David L.; Tabb, David L.; Stafford, John M.

2012-01-01

Mechanisms underlying changes in HDL composition caused by obesity are poorly defined, partly because mice lack expression of cholesteryl ester transfer protein (CETP), which shuttles triglyceride and cholesteryl ester between lipoproteins. Because menopause is associated with weight gain, altered glucose metabolism, and changes in HDL, we tested the effect of feeding a high-fat diet (HFD) and ovariectomy (OVX) on glucose metabolism and HDL composition in CETP transgenic mice. After OVX, female CETP-expressing mice had accelerated weight gain with HFD-feeding and impaired glucose tolerance by hyperglycemic clamp techniques, compared with OVX mice fed a low-fat diet (LFD). Sham-operated mice (SHAM) did not show HFD-induced weight gain and had less glucose intolerance than OVX mice. Using shotgun HDL proteomics, HFD-feeding in OVX mice had a large effect on HDL composition, including increased levels of apoA2, apoA4, apoC2, and apoC3, proteins involved in TG metabolism. These changes were associated with decreased hepatic expression of SR-B1, ABCA1, and LDL receptor, proteins involved in modulating the lipid content of HDL. In SHAM mice, there were minimal changes in HDL composition with HFD feeding. These studies suggest that the absence of ovarian hormones negatively influences the response to high-fat feeding in terms of glucose tolerance and HDL composition. CETP-expressing mice may represent a useful model to define how metabolic changes affect HDL composition and function. PMID:22215797

Steryl ester synthesis, storage and hydrolysis: A contribution to sterol homeostasis.

PubMed

Korber, Martina; Klein, Isabella; Daum, Günther

2017-12-01

Sterols are essential lipids of all eukaryotic cells, appearing either as free sterols or steryl esters. Besides other regulatory mechanisms, esterification of sterols and hydrolysis of steryl esters serve to buffer both an excess and a lack of free sterols. In this review, the esterification process, the storage of steryl esters and their mobilization will be described. Several model organisms are discussed but the focus was set on mammals and the yeast Saccharomyces cerevisiae. The contribution of imbalanced cholesterol homeostasis to several human diseases, namely Wolman disease, cholesteryl ester storage disease, atherosclerosis and Alzheimer's disease, Niemann-Pick type C and Tangier disease is described. Copyright © 2017 Elsevier B.V. All rights reserved.

Basal-bolus insulin therapy reduces maternal triglycerides in gestational diabetes without modifying cholesteryl ester transfer protein activity.

PubMed

Olmos, Pablo R; Borzone, Gisella R

2017-09-01

Macrosomia in the offspring of overweight/obese mothers with glucose-controlled gestational diabetes mellitus (GDM) is due to excessive rise of maternal triglycerides (TG). We aimed to ascertain whether basal-bolus insulin therapy (BBIT), or other components of the treatment, could reduce TG in GDM. We studied the records of 131 singleton pregnancies with GDM, using stepwise multiple linear regression, Mann-Whitney, χ 2 , and Jonckheere-Terpstra tests. As maternal TG increased steadily during normal pregnancy, these were transformed as z-scores. The atherogenic index of plasma (AIP) was calculated as a measure of cholesteryl ester transfer protein activity. Multiple regression showed that only BBIT (but neither limitation of weight gain nor metformin) reduced maternal TG z-scores (P = 0.011). When the 131 pregnancies were split into two groups - without BBIT (n = 58; HbA1c = 5.3 ± 0.3%) and with BBIT (n = 73; HbA1c = 5.4 ± 0.6; P = 0.2005) - we observed that BBIT (n = 73) reduced maternal TG z-scores in a dose-related fashion (Jonckheere-Terpstra P = 0.03817). The atherogenic index of plasma remained within normal range in both groups. BBIT (but not weight gain control nor metformin) reduced maternal TG in mothers with glucose-controlled GDM. This beneficial effect of BBIT was not related to changes in the cholesteryl ester transfer protein activity. © 2017 Japan Society of Obstetrics and Gynecology.

Cholesteryl Ester Transfer Protein Inhibitors in the Treatment of Dyslipidemia: A Systematic Review and Meta-Analysis

PubMed Central

Zhou, Faying; Chen, Caiyu; Zhou, Liang; Li, Yafei; Liu, Ling; Pei, Fang; Luo, Hao; Hu, Zhangxue; Cai, Jing; Zeng, Chunyu

2013-01-01

Cholesteryl ester transfer protein (CETP) inhibitors are gaining substantial research interest for raising high density lipoprotein cholesterol levels. The aim of the research was to estimate the efficacy and safety of cholesteryl ester transfer protein inhibitors as novel lipid modifying drugs. Systematic searches of English literature for randomized controlled trials (RCT) were collected from MEDLINE, EBASE, CENTRAL and references listed in eligible studies. Two independent authors assessed the search results and only included the double-blind RCTs by using cholesteryl ester transfer protein inhibitors as exclusively or co-administrated with statin therapy irrespective of gender in enrolled adult subjects. Two independent authors extracted the data by using predefined data fields. Of 503 studies identified, 14 studies met the inclusion criteria, and 12 studies were included into the final meta-analysis. Our meta-analysis revealed that CETP inhibitors increased the HDL-c levels (n = 2826, p<0.00001, mean difference (MD)  = 20.47, 95% CI [19.80 to 21.15]) and total cholesterol (n = 3423, p = 0.0002, MD = 3.57, 95%CI [1.69 to 5.44] to some extent combined with a reduction in triglyceride (n = 3739, p<0.00001, MD = −10.47, 95% CI [−11.91 to −9.03]) and LDL-c (n = 3159, p<0.00001, MD = −17.12, 95% CI [−18.87 to −15.36]) irrespective of mono-therapy or co-administration with statins. Subgroup analysis suggested that the lipid modifying effects varied according to the four currently available CETP inhibitors. CETP inhibitor therapy did not increase the adverse events when compared with control. However, we observed a slight increase in blood pressure (SBP, n = 2384, p<0.00001, MD = 2.73, 95% CI [2.14 to 3.31], DBP, n = 2384, p<0.00001, MD = 1.16, 95% CI [0.73 to 1.60]) after CETP inhibitor treatment, which were mainly ascribed to the torcetrapib treatment subgroup. CETP inhibitors therapy is associated with significant increase in HDL-c and decrease in triglyceride and LDL-c with satisfactory safety and tolerability in patients with dyslipidemia. However, the side-effect on blood pressure deserves more consideration in future studies. PMID:24204732

Low density lipoproteins develop resistance to oxidative modification due to inhibition of cholesteryl ester transfer protein by a monoclonal antibody.

PubMed

Sugano, M; Sawada, S; Tsuchida, K; Makino, N; Kamada, M

2000-01-01

Although numerous studies have investigated the relationship between cholesteryl ester transfer protein (CETP) and high density lipoprotein (HDL) remodeling, the relationship between CETP and low density lipoproteins (LDL) is still not fully understood. In the present study, we examined the effect of the inhibition of CETP on both LDL oxidation and the uptake of the oxidized LDL, which were made from LDL under condition of CETP inhibition, by macrophages using a monoclonal antibody (mAb) to CETP in incubated plasma. The 6-h incubation of plasma derived from healthy, fasting human subjects led to the transfer of cholesteryl ester (CE) from HDL to VLDL and LDL, and of triglycerides (TG) from VLDL to HDL and LDL. These net mass transfers of neutral lipids among the lipoproteins were eliminated by the mAb. The incubation of plasma either with or without the mAb did not affect the phospholipid compositions in any lipoproteins. As a result, the LDL fractionated from the plasma incubated with the mAb contained significantly less CE and TG in comparison to the LDL fractionated from the plasma incubated without the mAb. The percentage of fatty acid composition of LDL did not differ among the unincubated plasma, the plasma incubated with the mAb, and that incubated without the mAb. When LDL were oxidized with CuSO4, the LDL fractionated from the plasma incubated with the mAb were significantly resistant to the oxidative modification determined by measuring the amount of TBARS and by continuously monitoring the formation of the conjugated dienes, in comparison to the LDL fractionated from the plasma incubated without the mAb. The accumulation of cholesteryl ester of oxidized LDL, which had been oxidized for 2 h with CuSO4, in J774.1 cells also decreased significantly in the LDL fractionated from the plasma incubated with mAb in comparison to the LDL fractionated from the plasma incubated without the mAb. These results indicate that CETP inhibition reduces the composition of CE and TG in LDL and makes the LDL resistant to oxidation. In addition, the uptake of the oxidized LDL, which was made from the LDL under condition of CETP inhibition, by macrophages also decreased.

Antimicrobial Lipids: Novel Innate Defense Molecules are Elevated in Sinus Secretions of Patients with Chronic Rhinosinusitis

PubMed Central

Lee, Jivianne T.; Jansen, Mike; Yilma, Abebayehu N.; Nguyen, Angels; Desharnais, Robert; Porter, Edith

2010-01-01

Introduction Airway secretions possess intrinsic antimicrobial properties that contribute to the innate host defense of the respiratory tract. These microbicidal capabilities have largely been attributed to the presence of antibacterial polypeptides. However, recent investigation has demonstrated that host-derived lipids including cholesteryl esters also exhibit antimicrobial properties. The purpose of this study was to determine whether sinus secretions contain such antimicrobial lipids and to compare the lipid composition in patients with and without chronic rhinosinusitis (CRS). Methods Maxillary sinus fluid was obtained via antral lavage from subjects with (7) and without (9) a history of CRS. Following specimen collection, total lipid was extracted according to Bligh & Dyer and lipid profiles were obtained by reverse phase HPLC on an amide-embedded C18 column. In addition, the neutrophil specific antimicrobial peptides HNP1-3 were quantified by immunoblotting. Results Lipids were identified in the maxillary sinus secretions of patients with and without CRS including cholesteryl esters. However, levels of lipid composition differed between the two groups with CRS patients exhibiting greater amounts of all classes of lipids; reaching over 10-fold higher concentration when compared to nonCRS patients. This increase was independent of HNP1-3 content. Conclusions Sinus secretions of patients with CRS appear to demonstrate elevated levels of antimicrobial lipids compared to controls independent from neutrophil influx. This upregulation suggests that host-derived lipids act as mediators of mucosal immunity in CRS. Further study is necessary to determine if such antimicrobial lipids function alone or synergistically with antibacterial peptides in conferring such inherent microbicidal properties. PMID:20338107

Influence of supercritical CO(2) pressurization on the phase behavior of mixed cholesteryl esters.

PubMed

Huang, Zhen; Feng, Mei; Su, Junfeng; Guo, Yuhua; Liu, Tie-Yan; Chiew, Yee C

2010-09-15

Evidences indicating the presence of phase transformations in the mixed cholesteryl benzoate (CBE) and cholesteryl butyrate (CBU) under the supercritical CO(2) pressurization, by means of differential scanning calorimetry (DSC) and X-ray diffraction (XRD), are presented in this work. These include (1) the DSC heating curve of pure CBU; (2) the DSC heating curves of CBU/CBE mixtures; (3) the XRD spectra of pure CBU; (4) the XRD spectra of CBU/CBE mixtures; (5) CBU and CBE are miscible in either solid phase or liquid phase over the whole composition range. As a result of the presence of these phase transformations induced by pressurization, it could be deduced that a solid solution of the CBU/CBE mixture might have formed at the interfaces under supercritical conditions, subsequently influencing their dissolving behaviors in supercritical CO(2). Copyright 2010 Elsevier B.V. All rights reserved.

A chimeric peptide of intestinal trefoil factor containing cholesteryl ester transfer protein B cell epitope significantly inhibits atherosclerosis in rabbits after oral administration.

PubMed

Qi, Gaofu; Li, Jingjing; Wang, Shengying; Xin, Shanshan; Du, Peng; Zhang, Qingye; Zhao, Xiuyun

2011-04-01

Vaccination against cholesteryl ester transfer protein (CETP) is proven to be effective for inhibiting atherosclerosis in animal models. In this study, the proteases-resistant intestinal trefoil factor (TFF3) was used as a molecular vehicle to construct chimeric TFF3 (cTFF3) containing CETP B cell epitope and tetanus toxin helper T cell epitope. It was found that cTFF3 still preserved a trefoil structure, and can resist proteases digestion in vitro. After oral immunization with cTFF3, the CETP-specific IgA and IgG could be found in intestine lavage fluid and serum, and the anti-CETP antibodies could inhibit partial CETP activity to increase high-density lipoprotein cholesterol, decrease low-density lipoprotein cholesterol, and inhibit atherosclerosis in animals. Therefore, TFF3 is a potential molecular vehicle for developing oral peptide vaccines. Our research highlights a novel strategy for developing oral peptide vaccines in the future. Copyright © 2010 Elsevier Inc. All rights reserved.

Lipoprotein composition and oxidative modification during therapy with gemfibrozil and lovastatin in patients with combined hyperlipidaemia

PubMed Central

Vázquez, M; Zambón, D; Hernández, Y; Adzet, T; Merlos, M; Ros, E; Laguna, J C

1998-01-01

Aims To evaluate the resistance to oxidation of human lipoproteins after hypolipidaemic therapy. Methods VLDL and LDL samples were obtained from patients with Familial Combined Hyperlipidaemia included in a randomized, double-blind, cross-over study, with 8 weeks of active treatment (gemfibrozil, 600 mg twice daily, or lovastatin, 40 mg daily) and a 4-week wash-out period. Oxidation related analytes after Cu-induced oxidation of VLDL and LDL have been investigated. Further, in order to relate possible changes in oxidative behaviour to lipoprotein composition, the proportion of the lipid species transported by lipoproteins (triglycerides, phospholipids, and cholesteryl esters), the molar composition of fatty acids for each lipoprotein lipid, and the content of antioxidant vitamins in plasma (vitamin C) and lipoproteins (vitamin E) have been studied. Results Both drugs reduced the plasma concentration of apo-B lipoproteins (−23% gemfibrozil, −26% lovastatin), but whereas lovastatin affected mainly LDL-cholesterol (−30%), gemfibrozil reduced triglycerides (−49%) and VLDL-cholesterol (−48%). Lovastatin treatment had no effect on the lipid and protein composition, the fatty acid profile, or the vitamin E content of either VLDL or LDL; likewise, lipoprotein oxidation markers (Cu-induced conjugated dienes, thiobarbituric acid reactive substances formation, and lysine residues) were similar before and after lovastatin treatment. Gemfibrozil therapy also had no effect on lipoprotein oxidation; nevertheless, it consistently: a) decreased the proportion of LDL-triglycerides (−32%), and b) increased the proportion (molar%) of 18:3 n-6 in VLDL triglycerides (+140%), phospholipids (+363%) and cholesteryl esters (+53%). Conclusions Based on these results, lovastatin and gemfibrozil do not adversely affect lipoprotein oxidation in patients with mixed dyslipidaemia. In the case of gemfibrozil, this occurs in spite of an increased proportion of some polyunsaturated fatty acids in VLDL. In the context of a fixed dietary intake, such modifications suggest that the drug influences liver enzyme activities involved in fatty acid chain synthesis (elongases and desaturases). PMID:9517370

The reactivity of plasma phospholipids with lecithin:cholesterol acyltransferase is decreased in fish oil-fed monkeys.

PubMed

Parks, J S; Bullock, B C; Rudel, L L

1989-02-15

The size of low density lipoproteins (LDL) is strongly correlated with LDL cholesteryl ester (CE) content and coronary artery atherosclerosis in monkeys fed cholesterol and saturated fat. African green monkeys fed 11% (weight) fish oil diets have smaller LDL and less CE per LDL particle than lard-fed animals. We hypothesized that this might be due to a lower plasma lecithin:cholesterol acyltransferase (LCAT) activity in fish oil-fed animals. Using recombinant particles made of egg yolk lecithin-[14C]cholesterol-apoA-I as exogenous substrate, we found no difference in plasma LCAT activity (27 versus 28 nmol CE formed per h/ml) of fish oil- versus lard-fed animals, respectively; furthermore, no diet-induced difference in immunodetectable LCAT was found. However, plasma phospholipids from fish oil-fed animals were over 4-fold enriched in n-3 fatty acids in the sn-2 position compared to those of lard-fed animals. Additionally, the proportion of n-3 fatty acid-containing CE products formed by LCAT, relative to the available n-3 fatty acid in the sn-2 position of phospholipids, was less than one-tenth of that for linoleic acid. The overall rate of LCAT-catalyzed CE formation with phospholipid substrates from fish oil-fed animals was lower (5-50%) than with phospholipid substrates from lard-fed animals. These data show that n-3 fatty acids in phospholipids are not readily utilized by LCAT for formation of CE; rather, LCAT preferentially utilizes linoleic acid for CE formation. The amount of linoleic acid in the sn-2 position of plasma phospholipids is reduced and replaced with n-3 fatty acids in fish oil-fed animals. As a result, LCAT-catalyzed plasma CE formation in vivo is likely reduced in fish oil-fed animals contributing to the decreased cholesteryl ester content and smaller size of LDL particles in the animals of this diet group.

Appropriateness of the hamster as a model to study diet-induced atherosclerosis

USDA-ARS?s Scientific Manuscript database

Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apo...

Lipid-lowering effect of bergamot polyphenolic fraction: role of pancreatic cholesterol ester hydrolase.

PubMed

Musolino, V; Gliozzi, M; Carresi, C; Maiuolo, J; Mollace, R; Bosco, F; Scarano, F; Scicchitano, M; Maretta, A; Palma, E; Iannone, M; Morittu, V M; Gratteri, S; Muscoli, C; Fini, M; Mollace, V

2017-01-01

Bergamot polyphenolic fraction (BPF) has been shown to positively modulate several mechanisms involved in metabolic syndrome, suggesting its use in therapy. In particular, it is able to induce a significant amelioration of serum lipid profile in hyperlipemic patients at different levels. The purpose of our study was to investigate the effect of BPF on cholesterol absorption physiologically mediated by pancreatic cholesterol ester hydrolase (pCEH). An in vitro activity assay was performed to study the effect of BPF on pCEH, whereas the rate of cholesterol absorption was evaluated through in vivo studies. In particular, male, Sprague-Dawley rats (200–225 g) were fed either normal chow or chow supplemented with 0.5% cholic acid, 5.5% peanut oil, and varying amounts of cholesterol (0 to 1.5%). BPF (10 mg/Kg) was daily administrated by means of a gastric gavage to animals fed with lipid supplemented diet for 4 weeks and, at the end of the study, plasma lipids and liver cholesteryl esters were measured in all experimental groups. Our results show that BPF was able to inhibit pCEH activity and this effect was confirmed, in vivo, via detection of lymphatic cholesteryl ester in rats fed with a cholesterol-rich diet. This evidence clarifies a further mechanism responsible for the hypolipemic properties of BPF previously observed in humans, confirming its beneficial effect in the therapy of hypercholesterolemia and in the treatment of metabolic syndrome.

Direct interaction of Plin2 with lipids on the surface of lipid droplets: a live cell FRET analysis

PubMed Central

McIntosh, Avery L.; Senthivinayagam, Subramanian; Moon, Kenneth C.; Gupta, Shipra; Lwande, Joel S.; Murphy, Cameron C.; Storey, Stephen M.

2012-01-01

Despite increasing awareness of the health risks associated with excess lipid storage in cells and tissues, knowledge of events governing lipid exchange at the surface of lipid droplets remains unclear. To address this issue, fluorescence resonance energy transfer (FRET) was performed to examine live cell interactions of Plin2 with lipids involved in maintaining lipid droplet structure and function. FRET efficiencies (E) between CFP-labeled Plin2 and fluorescently labeled phosphatidylcholine, sphingomyelin, stearic acid, and cholesterol were quantitated on a pixel-by-pixel basis to generate FRET image maps that specified areas with high E (>60%) in lipid droplets. The mean E and the distance R between the probes indicated a high yield of energy transfer and demonstrated molecular distances on the order of 44–57 Å, in keeping with direct molecular contact. In contrast, FRET between CFP-Plin2 and Nile red was not detected, indicating that the CFP-Plin2/Nile red interaction was beyond FRET proximity (>100 Å). An examination of the effect of Plin2 on cellular metabolism revealed that triacylglycerol, fatty acid, and cholesteryl ester content increased while diacylglycerol remained constant in CFP-Plin2-overexpressing cells. Total phospholipids also increased, reflecting increased phosphatidylcholine and sphingomyelin. Consistent with these results, expression levels of enzymes involved in triacylglycerol, cholesteryl ester, and phospholipid synthesis were significantly upregulated in CFP-Plin2-expressing cells while those associated with lipolysis either decreased or were unaffected. Taken together, these data show for the first time that Plin2 interacts directly with lipids on the surface of lipid droplets and influences levels of key enzymes and lipids involved in maintaining lipid droplet structure and function. PMID:22744009

Antimicrobial lipids: novel innate defense molecules are elevated in sinus secretions of patients with chronic rhinosinusitis.

PubMed

Lee, Jivianne T; Jansen, Mike; Yilma, Abebayehu N; Nguyen, Angels; Desharnais, Robert; Porter, Edith

2010-01-01

Airway secretions possess intrinsic antimicrobial properties that contribute to the innate host defense of the respiratory tract. These microbicidal capabilities have largely been attributed to the presence of antibacterial polypeptides. However, recent investigation has indicated that host-derived lipids including cholesteryl esters also exhibit antimicrobial properties. The purpose of this study was to determine whether sinus secretions contain such antimicrobial lipids and to compare the lipid composition in patients with and without chronic rhinosinusitis (CRS). Maxillary sinus fluid was obtained via antral lavage from subjects with (seven patients) and without (nine patients) a history of CRS. After specimen collection, total lipid was extracted according to Bligh and Dyer (Bligh EG and Dyer WJ, A rapid method of total lipid extraction and purification, Can J Biochem Physiol 37:911-918, 1959) and lipid profiles were obtained by reverse phase high-performance liquid chromatography on an amide-embedded C18 column. In addition, the neutrophil-specific antimicrobial peptides human neutrophil peptides 1-3 (HNP1-3) were quantified by Western immunoblotting. Lipids, including cholesteryl esters, were identified in the maxillary sinus secretions of patients with and without CRS. However, levels of lipid composition differed between the two groups with CRS patients exhibiting greater amounts of all classes of lipids, reaching over 10-fold higher concentration when compared with non-CRS patients. This increase was independent of HNP1-3 content. Sinus secretions of patients with CRS appear to show elevated levels of antimicrobial lipids compared with controls independent from neutrophil influx. This up-regulation suggests that host-derived lipids act as mediators of mucosal immunity in CRS. Further study is necessary to determine if such antimicrobial lipids function alone or synergistically with antibacterial peptides in conferring such inherent microbicidal properties.

Newer antiatherosclerosis treatment strategies.

PubMed

Aggarwal, Amitesh; Singh, Safal

2011-01-01

Atherosclerosis has been a target of much clinical and molecular research. As a result of this extensive research, it is amply clear that atherogenesis is a multifactorial process involving an interplay of metabolic, immune and inflammatory mechanisms. Antiatherosclerotic strategies are today aiming for a multipronged approach targeting each arm of this multifactorial process. The newer agents under development can be divided into three broad categories: anti-inflammatory agents, modulators of intermediary metabolism and antiatherosclerosis vaccines. Potential targets for anti-inflammatory agents include inhibition of conversion of low-density lipoprotein (LDL) to oxidised LDL, blocking or downregulation of cell adhesion molecules, chemokine modulation and macrophage receptor blockade. Beyond inhibition of plaque formation, efforts are also ongoing to develop agents which stabilise the plaque by increasing its fibrous content and inhibiting its disruption. So far as research in the sphere of intermediary metabolism is concerned, the focus is now primarily on raising high-density lipoprotein and promoting reverse cholesterol transport; potential targets include cholesteryl ester transfer protein, liver X-receptor, lecithin cholesterol acyltransferase and high-density lipoprotein mimetics. Acyl-coenzymeA: cholesterol acyltransferase is another enzyme whose selective and differential inhibition is under active investigation. The concept of immunisation against a non-communicable disease such as atherosclerosis is still in its nascent stages. However, with increasing evidence to suggest the role of antigen-specific T-cell-mediated immunity in atherogenesis, this approach is potentially promising. Possible antigens under evaluation include oxidised LDL and its subparticles, heat-shock proteins and cholesteryl ester transfer protein. With cardiovascular disease being the single leading cause of death worldwide, the development of a safe and successful antiatherosclerosis strategy (possibly employing a combination of agents acting at various levels) will indeed be a major 21st-century achievement.

Effects of cholesteryl ester transfer protein inhibition on apolipoprotein (apo) A-II-containing HDL subspecies and apoA-II metabolism

USDA-ARS?s Scientific Manuscript database

Studies in animals have documented that, compared with glucose, dietary fructose induces dyslipidemia and insulin resistance. To assess the relative effects of these dietary sugars during sustained consumption in humans, overweight and obese subjects consumed glucose- or fructose-sweetened beverages...

Inhibiting LDL glycation ameliorates increased cholesteryl ester synthesis in macrophages and hypercholesterolemia and aortic lipid peroxidation in streptozotocin diabetic rats

PubMed Central

Cohen, Margo P.; Shea, Elizabeth A.; Wu, Van-Yu

2009-01-01

Increased nonenzymatic glycation of apoB-containing lipoproteins impairs uptake and metabolism by the high affinity low density lipoprotein (LDL) receptor, and is one of the post-secretory modifications contributory to accelerated atherosclerosis in diabetes. The present study evaluated in vitro and in vivo effects of 2,2-chlorophenylaminophenylacetate (CAP22) to probe the influence of glycated lipoprotein on cholesterol homeostasis. This compound prevented the increased formation of glycated products in LDL incubated with 200 mM glucose and the increased cholesteryl ester synthesis in THP-1 macrophages induced by apoB-containing lipoproteins preincubated with high glucose concentration. The elevated circulating concentrations of glycated lipoprotein and cholesterol and higher vascular levels of lipid peroxidation products observed in streptozotocin diabetic rats compared to nondiabetic controls were significantly reduced in diabetic animals treated for six months with test compound. These results are the first to demonstrate that inhibiting nonenzymatic glycation of apoB-containing lipoproteins ameliorates abnormalities contributory to hypercholesterolemia and atherogenic risk in diabetes. PMID:19922964

Targeting Wolman Disease and Cholesteryl Ester Storage Disease: Disease Pathogenesis and Therapeutic Development

PubMed Central

Aguisanda, Francis; Thorne, Natasha; Zheng, Wei

2017-01-01

Wolman disease (WD) and cholesteryl ester storage disease (CESD) are lysosomal storage diseases (LSDs) caused by a deficiency in lysosomal acid lipase (LAL) due to mutations in the LIPA gene. This enzyme is critical to the proper degradation of cholesterol in the lysosome. LAL function is completely lost in WD while some residual activity remains in CESD. Both are rare diseases with an incidence rate of less than 1/100,000 births for WD and approximate 2.5/100,000 births for CESD. Clinical manifestation of WD includes hepatosplenomegaly, calcified adrenal glands, severe malabsorption and a failure to thrive. As in CESD, histological analysis of WD tissues reveals the accumulation of triglycerides (TGs) and esterified cholesterol (EC) in cellular lysosomes. However, the clinical presentation of CESD is less severe and more variable than WD. This review is to provide an overview of the disease pathophysiology and the current state of therapeutic development for both of WD and CESD. The review will also discuss the application of patient derived iPSCs for further drug discovery. PMID:28401034

Association of Cholesteryl Ester Transfer Protein and Endothelial Nitric Oxide Synthase Gene Polymorphisms With Coronary Artery Disease in the Multi-Ethnic Malaysian Population.

PubMed

Chu, Wern Cui; Aziz, Ahmad Fazli Abdul; Nordin, Abdul Jalil; Cheah, Yoke Kqueen

2016-09-01

Genetic variants of cholesteryl ester transfer protein (CETP) and endothelial nitric oxide synthase (eNOS) influence high-density lipoprotein cholesterol (HDL-C) metabolism and nitric oxide (NO) synthesis, respectively, and might increase the risk of coronary artery disease (CAD). This study is to investigate the relationship between genetic polymorphisms and the risk of CAD and to evaluate their potential interactions. A total of 237 patients with CAD and 101 controls were genotyped. The association of the polymorphism with the risk of CAD varied among the ethnic groups. Moreover, the concomitant presence of both CETP B1 and eNOS 4a alleles significantly increased the risk of CAD in the Malay group (OR = 33.8, P < .001) and the Indian group (OR = 10.9, P = .031) but not in the Chinese group. This study has identified a novel ethnic-specific gene-gene interaction and suggested that the combination of CETP B1 allele and eNOS 4a allele significantly increases the risk of CAD in Malays and Indians. © The Author(s) 2015.

Effect of lipid emulsions on the plasma lecithin: cholesterol acyltransfer in guinea pigs.

PubMed

Drevon, C A; Norum, K R

1975-01-01

Addition of triglyceride/phospholipid emulsion to adult guinea pig plasma more than doubled the cholesteryl ester (CE) production. Plasma from newborn guinea pigs was stimulated to a lower degree. The increase in CE production was dependant on the type and amount of phospholipids in the lipid emulsions. Egg phospholipids stimulated the cholesterol esterification while partially hydrogenated soy phospholipids (with high content of saturated fatty acids) inhibited the reaction. The stimulation of CE formation was probably due to transfer of phosphatidyl choline (PC) from the emulsion to the high density lipoproteins since the stimulation was: (a) dependant on a preincubation time, (b) less pronounced in newborn animals with high plasma PC levels, and (c) detected in plasma fractions from which the lipid emulsion had been removed.

Plasma kinetics of chylomicron-like emulsion and lipid transfers to high-density lipoprotein (HDL) in lacto-ovo vegetarian and in omnivorous subjects.

PubMed

Vinagre, Juliana C; Vinagre, Carmen C G; Pozzi, Fernanda S; Zácari, Cristiane Z; Maranhão, Raul C

2014-04-01

Previously, it was showed that vegan diet improves the metabolism of triglyceride-rich lipoproteins by increasing the plasma clearance of atherogenic remnants. The aim of the current study was to investigate this metabolism in lacto-ovo vegetarians whose diet is less strict, allowing the ingestion of eggs and milk. Transfer of lipids to HDL, an important step in HDL metabolism, was tested in vitro. Eighteen lacto-ovo vegetarians and 29 omnivorous subjects, all eutrophic and normolipidemic, were intravenously injected with triglyceride-rich emulsions labeled with ¹⁴C-cholesterol oleate and ³H-triolein. Fractional clearance rates (FCR, in min⁻¹) were calculated from samples collected during 60 min. Lipid transfer to HDL was assayed by incubating plasma samples with a donor nanoemulsion labeled with radioactive lipids. LDL cholesterol was lower in vegetarians than in omnivores (2.1 ± 0.8 and 2.7 ± 0.7 mmol/L, respectively, p < 0.05), but HDL cholesterol and triglycerides were equal. Cholesteryl ester FCR was greater in vegetarians than in omnivores (0.016 ± 0.012, 0.003 ± 0.003, p < 0.01), whereas triglyceride FCR was equal. Cholesteryl ester transfer to HDL was lower in vegetarians than in omnivores (2.7 ± 0.6, 3.5 ± 1.5 %, p < 0.05), but free cholesterol, triglyceride and phospholipid transfers and HDL size were equal. Similarly to vegans, lacto-ovo vegetarian diet increases remnant removal, as indicated by cholesteryl oleate FCR, which may favor atherosclerosis prevention, and has the ability to change lipid transfer to HDL.

Beneficial effect of CETP gene polymorphism in combination with a Mediterranean diet influencing lipid metabolism in metabolic syndrome patients: CORDIOPREV study

USDA-ARS?s Scientific Manuscript database

The cholesteryl ester transfer protein (CETP) gene has been implicated in high-density lipoprotein (HDL-C) metabolism. However, little is known about the impact of this gene on metabolic syndrome (MetS) patients and its interaction with diet. Here, we evaluate whether the consumption of a Mediterran...

Plasma Phosphatidylethanolamine and Triacylglycerol Fatty Acid Concentrations are Altered in Major Depressive Disorder Patients with Seasonal Pattern.

PubMed

Otoki, Yurika; Hennebelle, Marie; Levitt, Anthony J; Nakagawa, Kiyotaka; Swardfager, Walter; Taha, Ameer Y

2017-06-01

Disturbances in peripheral and brain lipid metabolism, including the omega-3 fatty acid docosahexaenoic acid (DHA), have been reported in major depressive disorder (MDD). However, these changes have yet to be confirmed in MDD with seasonal pattern (MDD-s), a subtype of recurrent MDD. The present exploratory study quantified plasma plasmalogen and diacyl-phospholipid species, and fatty acids within total phospholipids, cholesteryl esters, triacylglycerols and free fatty acids in non-medicated MDD-s participants (n = 9) during euthymia in summer or fall, and during depression in winter in order to screen for potential high sensitivity lipid biomarkers. Triacylglycerol alpha-linolenic acid concentration was significantly decreased, and myristoleic acid concentration was significantly increased, during winter depression compared to summer-fall euthymia. 1-stearyl-2-docosahexaenoyl-sn-glycero-3-phosphoethanolamine, a diacyl-phospholipid containing stearic acid and DHA, was significantly decreased in winter depression. Concentrations of cholesteryl ester oleic acid and several polyunsaturated fatty acids between summer/fall and winter increased in proportion to the increase in depressive symptoms. The observed changes in lipid metabolic pathways in winter-type MDD-s offer new promise for lipid biomarker development.

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

Lei, Dongsheng; Rames, Matthew; Zhang, Xing

Cholesteryl ester transfer protein (CETP) mediates cholesteryl ester (CE) transfer from the atheroprotective high density lipoprotein (HDL) cholesterol to the atherogenic low density lipoprotein cholesterol. In the past decade, this property has driven the development of CETP inhibitors, which have been evaluated in large scale clinical trials for treating cardiovascular diseases. Despite the pharmacological interest, little is known about the fundamental mechanism of CETP in CE transfer. Recent electron microscopy (EM) experiments have suggested a tunnel mechanism, and molecular dynamics simulations have shown that the flexible N-terminal distal end of CETP penetrates into the HDL surface and takes up amore » CE molecule through an open pore. However, it is not known whether a CE molecule can completely transfer through an entire CETP molecule. Here, we used all-atom molecular dynamics simulations to evaluate this possibility. The results showed that a hydrophobic tunnel inside CETP is sufficient to allow a CE molecule to completely transfer through the entire CETP within a predicted transfer time and at a rate comparable with those obtained through physiological measurements. Analyses of the detailed interactions revealed several residues that might be critical for CETP function, which may provide important clues for the effective development of CETP inhibitors and treatment of cardiovascular diseases.« less

Hyperspectral-stimulated Raman scattering imaging of cholesteryl ester accumulation: new avenue to diagnosis of human prostate cancer

NASA Astrophysics Data System (ADS)

Du, Jun; Wang, Ping; Yue, Shuhua

2016-10-01

Most prostate cancers (PCa) are slowly growing, and only the aggressive ones require early diagnosis and effective treatment. The current standard for PCa diagnosis remains histopathology. Nonetheless, for the differentiation between Gleason score 6 (low-risk PCa), which can be left without treatment, and Gleason score 7 (high-risk PCa), which requires active treatment, the inter-observer discordance can be up to 40%. Our previous study reveals that cholesteryl ester (CE) accumulation induced by PI3K/AKT activation underlies human PCa aggressiveness. However, Raman spectromicroscopy used in this study could only provide compositional information of certain lipid droplets (LDs) selected by the observer, which overlooked cell-to-cell variation and hindered translation to accurate automated diagnosis. Here, we demonstrated quantitative mapping of CE level in human prostate tissues using hyperspectral stimulated Raman scattering (SRS) microscopy that renders compositional information for every pixel in the image. Specifically, hundreds of SRS images at Raman shift between 1620-1800 cm-1 were taken, and multivariate curve resolution algorism was used to retrieve concentration images of acyl C=C bond, sterol C=C bond, and ester C=O bond. Given that the ratio between images of sterol C=C and ester C=O (sterol C=C/C=O) is nonlinearly proportional to CE percentage out of total lipid, we were able to quantitatively map CE level. Our data showed that CE level was significantly greater in high Gleason grade compared to low Gleason grade, and could be a factor that significantly contributed to cancer recurrence. Our study provides an opportunity towards more accurate PCa diagnosis and prediction of aggressiveness.

Integration of lipidomics and transcriptomics unravels aberrant lipid metabolism and defines cholesteryl oleate as potential biomarker of prostate cancer

NASA Astrophysics Data System (ADS)

Li, Jia; Ren, Shancheng; Piao, Hai-Long; Wang, Fubo; Yin, Peiyuan; Xu, Chuanliang; Lu, Xin; Ye, Guozhu; Shao, Yaping; Yan, Min; Zhao, Xinjie; Sun, Yinghao; Xu, Guowang

2016-02-01

In-depth delineation of lipid metabolism in prostate cancer (PCa) is significant to open new insights into prostate tumorigenesis and progression, and provide potential biomarkers with greater accuracy for improved diagnosis. Here, we performed lipidomics and transcriptomics in paired prostate cancer tumor (PCT) and adjacent nontumor (ANT) tissues, followed by external validation of biomarker candidates. We identified major dysregulated pathways involving lipogenesis, lipid uptake and phospholipids remodeling, correlated with widespread lipid accumulation and lipid compositional reprogramming in PCa. Specifically, cholesteryl esters (CEs) were most prominently accumulated in PCa, and significantly associated with cancer progression and metastasis. We showed that overexpressed scavenger receptor class B type I (SR-BI) may contribute to CEs accumulation. In discovery set, CEs robustly differentiated PCa from nontumor (area under curve (AUC) of receiver operating characteristics (ROC), 0.90-0.94). In validation set, CEs potently distinguished PCa and non-malignance (AUC, 0.84-0.91), and discriminated PCa and benign prostatic hyperplasia (BPH) (AUC, 0.90-0.96), superior to serum prostate-specific antigen (PSA) (AUC = 0.83). Cholesteryl oleate showed highest AUCs in distinguishing PCa from non-malignance or BPH (AUC = 0.91 and 0.96). Collectively, our results unravel the major lipid metabolic aberrations in PCa and imply the potential role of CEs, particularly, cholesteryl oleate, as molecular biomarker for PCa detection.

Depression of the Lecithin-Cholesterol Acyltransferase Reaction in Vitamin E-Deficient Monkeys,

DTIC Science & Technology

Vitamin E deficiency in two species of monkeys reduced the esterification of cholesterol by the plasma lecithin -cholesterol acyltransferase reaction...depression in the concentration of circulating polyunsaturated fatty acid cholesteryl esters. Since the plasma lecithin -cholesterol acyltransferase...cholesterol by plasma from vitamin E-deficient monkeys is due to alteration of these sulfhydryl sites. A similar reduction in the plasma lecithin -cholesterol

Clinical Effect and Safety Profile of Recombinant Human Lysosomal Acid Lipase in Patients with Cholesteryl Ester Storage Disease

PubMed Central

Balwani, Manisha; Breen, Catherine; Enns, Gregory M; Deegan, Patrick B; Honzík, Tomas; Jones, Simon; Kane, John P; Malinova, Vera; Sharma, Reena; Stock, Eveline O; Valayannopoulos, Vassili; Wraith, J Edmond; Burg, Jennifer; Eckert, Stephen; Schneider, Eugene; Quinn, Anthony G

2013-01-01

Background & Aims Cholesteryl Ester Storage Disease, an inherited deficiency of lysosomal acid lipase, is an underappreciated cause of progressive liver disease with no approved therapy. Presenting features include dyslipidemia, elevated transaminases, and hepatomegaly. Methods To assess the clinical effects and safety of the recombinant human lysosomal acid lipase, sebelipase alfa, 9 patients received 4 once-weekly infusions (0.35, 1, or 3 mg·kg−1) in LAL-CL01 which is the first human study of this investigational agent. Patients completing LAL-CL01 were eligible to enroll in the extension study (LAL-CL04) in which they again received 4 once-weekly infusions of sebelipase alfa (0.35, 1, or 3 mg·kg−1) before transitioning to long term every other week infusions (1 or 3 mg·kg−1). Results Sebelipase alfa was well-tolerated with mostly mild adverse events unrelated sebelipase alfa. No anti-drug antibodies were detected. Transaminases decreased in patients in LAL-CL01 and increased between studies. In 7 patients receiving ongoing sebelipase alfa treatment in LAL-CL04, mean±SD decreases for alanine transaminase and aspartate aminotransferase at week 12 compared to the baseline values in LAL-CL01 were 46±21U/L (-52%) and 21±14U/L (-36%), respectively (p<0.05). Through week 12 of LAL-CL04, these 7 patients also showed mean decreases from baseline in total cholesterol of 44±41mg/dL (-22%; p=0.047), low density lipoprotein-cholesterol of 29±31mg/dL (-27%; p=0.078), and triglycerides of 50±38mg/dL (-28%, p=0.016) and increases in high density lipoprotein-cholesterol of 5mg/dL (15%; p=0.016). Conclusions These data establish that sebelipase alfa, an investigational enzyme replacement, in patients with Cholesteryl Ester Storage Disease is well tolerated, rapidly decreases serum transaminases and that these improvements are sustained with long term dosing and are accompanied by improvements in serum lipid profile. PMID:23348766

Aerobic exercise improves reverse cholesterol transport in cholesteryl ester transfer protein transgenic mice.

PubMed

Rocco, D D F M; Okuda, L S; Pinto, R S; Ferreira, F D; Kubo, S K; Nakandakare, E R; Quintão, E C R; Catanozi, S; Passarelli, M

2011-07-01

We analyzed the effect of a 6-week aerobic exercise training program on the in vivo macrophage reverse cholesterol transport (RCT) in human cholesteryl ester transfer protein (CETP) transgenic (CETP-tg) mice. Male CETP-tg mice were randomly assigned to a sedentary group or a carefully supervised exercise training group (treadmill 15 m/min, 30 min sessions, five sessions per week). The levels of plasma lipids were determined by enzymatic methods, and the lipoprotein profile was determined by fast protein liquid chromatography (FPLC). CETP activity was determined by measuring the transfer rate of ¹⁴C-cholesterol from HDL to apo-B containing lipoproteins, using plasma from CETP-tg mice as a source of CETP. The reverse cholesterol transport was determined in vivo by measuring the [³H]-cholesterol recovery in plasma and feces (24 and 48 h) and in the liver (48 h) following a peritoneal injection of [³H]-cholesterol labeled J774-macrophages into both sedentary and exercise trained mice. The protein levels of liver receptors were determined by immunoblot, and the mRNA levels for liver enzymes were measured using RT-PCR. Exercise training did not significantly affect the levels of plasma lipids or CETP activity. The HDL fraction assessed by FPLC was higher in exercise-trained compared to sedentary mice. In comparison to the sedentary group, a greater recovery of [³H]-cholesterol from the injected macrophages was found in the plasma, liver and feces of exercise-trained animals. The latter occurred even with a reduction in the liver CYP7A1 mRNA level in exercised trained animals. Exercise training increased the liver LDL receptor and ABCA-1 protein levels, although the SR-BI protein content was unchanged. The RCT benefit in CETP-tg mice elicited by exercise training helps to elucidate the role of exercise in the prevention of atherosclerosis in humans.

Effect of antisense oligonucleotides against cholesteryl ester transfer protein on the development of atherosclerosis in cholesterol-fed rabbits.

PubMed

Sugano, M; Makino, N; Sawada, S; Otsuka, S; Watanabe, M; Okamoto, H; Kamada, M; Mizushima, A

1998-02-27

Cholesteryl ester transfer protein (CETP) is the enzyme that facilitates the transfer of cholesteryl ester from high density lipoprotein (HDL) to apolipoprotein B (apoB)-containing lipoproteins. However, the exact role of CETP in the development of atherosclerosis has not been determined. In the present study, we examined the effect of the suppression of increased plasma CETP by intravenous injection with antisense oligodeoxynucleotides (ODNs) against CETP targeted to the liver on the development of atherosclerosis in rabbits fed a cholesterol diet. The ODNs against rabbit CETP were coupled to asialoglycoprotein (ASOR) carrier molecules, which serve as an important method to regulate liver gene expression. Twenty-two male Japanese White rabbits were used in the experiment. Eighteen animals were fed a standard rabbit chow supplemented with 0.3% cholesterol throughout the experiment for 16 weeks. At 8 weeks, they were divided into three groups (six animals in each group), among which the plasma total and HDL cholesterol concentrations did not significantly change. The control group received nothing, the sense group were injected with the sense ODNs complex, and the antisense group were injected with the antisense ODNs complex, respectively, for subsequent 8 weeks. ASOR. poly(L-lysine) ODNs complex were injected via the ear veins twice a week. Four animals were fed a standard rabbit diet for 16 weeks. The total cholesterol concentrations and the CETP mass in the animals injected with antisense ODNs were all significantly decreased in 12 and 16 weeks compared with those injected with sense ODNs and the control animals. The HDL cholesterol concentrations measured by the precipitation assay did not significantly change among the groups fed a cholesterol diet, and triglyceride concentrations did not significantly change in the four groups. However, at the end of the study, when the HDL cholesterol concentrations were measured after the isolation by ultracentrifugation and a column chromotography, they were significantly higher in the animals injected with antisense ODNs than in the animals injected with sense ODNs and in the control animals. A reduction of CETP mRNA and an increase of LDL receptor mRNA in the liver were observed in the animals injected with antisense ODNs compared with those injected with sense ODNs and the control animals. Aortic cholesterol contents and the aortic percentage lesion to total surface area were significantly lower in the animals injected with antisense ODNs than in the animals injected with sense ODNs and in the control animals. These findings showed for the first time that suppression of increased plasma CETP by the injection with antisense ODNs against CETP coupled to ASOR carrier molecules targeted to the liver could thus inhibit the atherosclerosis possibly by decreasing the plasma LDL + very low density lipoprotein (VLDL) cholesterol in cholesterol-fed rabbits.

Aspartame-fed zebrafish exhibit acute deaths with swimming defects and saccharin-fed zebrafish have elevation of cholesteryl ester transfer protein activity in hypercholesterolemia.

PubMed

Kim, Jae-Yong; Seo, Juyi; Cho, Kyung-Hyun

2011-11-01

Although many artificial sweeteners (AS) have safety issues, the AS have been widely used in industry. To determine the physiologic effect of AS in the presence of hyperlipidemia, zebrafish were fed aspartame or saccharin with a high-cholesterol diet (HCD). After 12 days, 30% of zebrafish, which consumed aspartame and HCD, died with exhibiting swimming defects. The aspartame group had 65% survivability, while the control and saccharin groups had 100% survivability. Under HCD, the saccharin-fed groups had the highest increase in the serum cholesterol level (599 mg/dL). Aspartame-fed group showed a remarkable increase in serum glucose (up to 125 mg/dL), which was 58% greater than the increase in the HCD alone group. The saccharin and HCD groups had the highest cholesteryl ester transfer protein (CETP) activity (52% CE-transfer), while the HCD alone group had 42% CE-transfer. Histologic analysis revealed that the aspartame and HCD groups showed more infiltration of inflammatory cells in the brain and liver sections. Conclusively, under presence of hyperlipidemia, aspartame-fed zebrafish exhibited acute swimming defects with an increase in brain inflammation. Saccharin-fed zebrafish had an increased atherogenic serum lipid profile with elevation of CETP activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Interaction between dietary lipids and gut microbiota regulates hepatic cholesterol metabolism.

PubMed

Caesar, Robert; Nygren, Heli; Orešič, Matej; Bäckhed, Fredrik

2016-03-01

The gut microbiota influences many aspects of host metabolism. We have previously shown that the presence of a gut microbiota remodels lipid composition. Here we investigated how interaction between gut microbiota and dietary lipids regulates lipid composition in the liver and plasma, and gene expression in the liver. Germ-free and conventionally raised mice were fed a lard or fish oil diet for 11 weeks. We performed lipidomics analysis of the liver and serum and microarray analysis of the liver. As expected, most of the variation in the lipidomics dataset was induced by the diet, and abundance of most lipid classes differed between mice fed lard and fish oil. However, the gut microbiota also affected lipid composition. The gut microbiota increased hepatic levels of cholesterol and cholesteryl esters in mice fed lard, but not in mice fed fish oil. Serum levels of cholesterol and cholesteryl esters were not affected by the gut microbiota. Genes encoding enzymes involved in cholesterol biosynthesis were downregulated by the gut microbiota in mice fed lard and were expressed at a low level in mice fed fish oil independent of microbial status. In summary, we show that gut microbiota-induced regulation of hepatic cholesterol metabolism is dependent on dietary lipid composition. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Polyhedral 3D structure of human plasma very low density lipoproteins by individual particle cryo-electron tomography

DOE PAGES

Yu, Yadong; Kuang, Yu-Lin; Lei, Dongsheng; ...

2016-08-18

Human VLDLs assembled in the liver and secreted into the circulation supply energy to peripheral tissues. VLDL lipolysis yields atherogenic LDLs and VLDL remnants that strongly correlate with CVD. Although the composition of VLDL particles has been well-characterized, their 3D structure is elusive because of their variations in size, heterogeneity in composition, structural flexibility, and mobility in solution. Here, we employed cryo-electron microscopy and individual-particle electron tomography to study the 3D structure of individual VLDL particles (without averaging) at both below and above their lipid phase transition temperatures. The 3D reconstructions of VLDL and VLDL bound to antibodies revealed anmore » unexpected polyhedral shape, in contrast to the generally accepted model of a spherical emulsion-like particle. The smaller curvature of surface lipids compared with HDL may also reduce surface hydrophobicity, resulting in lower binding affinity to the hydrophobic distal end of the N-terminal β-barrel domain of cholesteryl ester transfer protein (CETP) compared with HDL. The directional binding of CETP to HDL and VLDL may explain the function of CETP in transferring TGs and cholesteryl esters between these particles. This first visualization of the 3D structure of VLDL could improve our understanding of the role of VLDL in atherogenesis.« less

Cannabinoids impair the formation of cholesteryl ester in cultured human cells.

PubMed

Cornicelli, J A; Gilman, S R; Krom, B A; Kottke, B A

1981-01-01

The ability of cultured human fibroblasts to form cholesteryl esters from 14C-oleate is impaired by delta'-tetrahydrocannabinol, cannabidiol, and cannabinol, a group of natural products isolated from Cannabis sativa. This inhibition is compound and dose-related; 30 microM cannabidiol reduced esterification to less than 20% of the control values. The esterification of endogenous and exogenous cholesterol was affected, since inhibition was seen with either low density lipoproteins (200 micrograms/ml) or 25-hydroxycholesterol (5 micrograms/ml) as esterification stimuli. Cells treated with these compounds at doses of from 1 to 30 microM showed no impairment of protein synthesis, triglyceride or phospholipid formation, or ability to metabolize 125I-low density lipoproteins. An inhibition of cholesterol esterification was seen in human aortic medial cells. With increasing doses of these compounds, low density lipoproteins (25 micrograms/ml) became progressively less effective in suppressing HMG-CoA reductase in cultured human fibroblasts; with 30 microM cannabidiol the enzyme suppression was only 24% of that found in cells incubated with low density lipoproteins in the absence of drugs. Based on these data, we conclude that the cannabinoids "compartmentalize" cholesterol and, thus, make is unavailable for regulating cellular cholesterol metabolism. This may occur as a result of enhanced sterol efflux.

Pyrene-Labeled Amphiphiles: Dynamic And Structural Probes Of Membranes And Lipoproteins

NASA Astrophysics Data System (ADS)

Pownall, Henry J.; Homan, Reynold; Massey, John B.

1987-01-01

Lipids and proteins are important functional and structural components of living organisms. Although proteins are frequently found as soluble components of plasma or the cell cytoplasm, many lipids are much less soluble and separate into complex assemblies that usually contain proteins. Cell membranes and plasma lipoproteins' are two important macro-molecular assemblies that contain both lipids and proteins. Cell membranes are composed of a variety of lipids and proteins that form an insoluble bilayer array that has relatively little curvature over distances of several nm. Plasma lipoproteins are different in that they are much smaller, water-soluble, and have highly curved surfaces. A model of a high density lipoprotein (HDL) is shown in Figure 1. This model (d - 10 nm) contains a surface of polar lipids and proteins that surrounds a small core of insoluble lipids, mostly triglycerides and cholesteryl esters. The low density (LDL) (d - 25 nm) and very low density (VLDL) (d 90 nm) lipoproteins have similar architectures, except the former has a cholesteryl ester core and the latter a core that is almost exclusively triglyceride (Figure 1). The surface proteins of HDL are amphiphilic and water soluble; the single protein of LDL is insoluble, whereas VLDL contains both soluble and insoluble proteins. The primary structures of all of these proteins are known.

Some Lipid Droplets Are More Equal Than Others: Different Metabolic Lipid Droplet Pools in Hepatic Stellate Cells.

PubMed

Molenaar, Martijn R; Vaandrager, Arie B; Helms, J Bernd

2017-01-01

Hepatic stellate cells (HSCs) are professional lipid-storing cells and are unique in their property to store most of the retinol (vitamin A) as retinyl esters in large-sized lipid droplets. Hepatic stellate cell activation is a critical step in the development of chronic liver disease, as activated HSCs cause fibrosis. During activation, HSCs lose their lipid droplets containing triacylglycerols, cholesteryl esters, and retinyl esters. Lipidomic analysis revealed that the dynamics of disappearance of these different classes of neutral lipids are, however, very different from each other. Although retinyl esters steadily decrease during HSC activation, triacylglycerols have multiple pools one of which becomes transiently enriched in polyunsaturated fatty acids before disappearing. These observations are consistent with the existence of preexisting "original" lipid droplets with relatively slow turnover and rapidly recycling lipid droplets that transiently appear during activation of HSCs. Elucidation of the molecular machinery involved in the regulation of these distinct lipid droplet pools may open new avenues for the treatment of liver fibrosis.

Modification of the plasma clearance and liver uptake of steroid ester-conjugated oligodeoxynucleotides by association with (lactosylated) low-density lipoprotein.

PubMed

Rump, E T; de Vrueh, R L; Manoharan, M; Waarlo, I H; van Veghel, R; Biessen, E A; van Berkel, T J; Bijsterbosch, M K

2000-06-01

Low-density lipoprotein (LDL) has been proposed as carrier for the selective delivery of anticancer drugs to tumor cells. We reported earlier the association of several lipidic steroid-conjugated anticancer oligodeoxynucleotides (ODNs) with LDL. In the present study, we determined the stability of these complexes. When the complexes were incubated with a mixture of high-density lipoprotein and albumin, or with rat plasma, the oleoyl steroid-conjugated ODNs appeared to be more stably associated with LDL than the cholesteryl-conjugated ODN. Intravenously injected free lipid-ODNs were very rapidly cleared from the circulation of rats. The area under the curve (AUC) of the lipid-ODNs in plasma was <0.4 microg x min/mL. After complexation with LDL, plasma clearance of the lipid-ODNs was delayed. This was most evident for ODN-5, the ODN conjugated with the oleoyl ester of lithocholic acid (AUC = 6.82 +/- 1.34 microg x min/mL). The AUC of ODN-4, a cholesteryl-conjugated ODN, was 1.49 +/- 0.37 microg x min/mL. In addition, the liver uptake of the LDL-complexed lipid-ODNs was reduced. The lipid-ODNs were also administered as a complex with lactosylated LDL, a modified LDL particle that is selectively taken up by the liver. A high proportion of ODN-5 was transported to the liver along with lactosylated LDL (69.1 +/- 8.1% of the dose at 15 min after injection), whereas much less ODN-4 was transported (36.6 +/- 0.1% of the dose at 15 min after injection). We conclude that the oleoyl ester of lithocholic acid is a more potent lipid anchor than the other steroid lipid anchors. Because of the stable association, the oleoyl ester of lithocholic acid is an interesting candidate for tumor targeting of anticancer ODNs with lipoproteins.

Stereoselective formation of a cholesterol ester conjugate from fenvalerate by mouse microsomal carboxyesterase(s).

PubMed

Miyamoto, J; Kaneko, H; Takamatsu, Y

1986-06-01

In accordance with in vivo findings, of the four chiral isomers of fenvalerate (S-5602 Sumicidin, Pydrin, [RS]-alpha-cyano-3-phenoxybenzyl [RS]-2-(4-chlorophenyl)isovalerate), only the [2R, alpha S]-isomer (B-isomer) yielded cholesteryl [2R]-2-(4-chlorophenyl)isovalerate (CPIA-cholesterol ester) in the in vitro study using several tissue homogenates of mice, rats, dogs, and monkeys. There were species differences in the extent of CPIA-cholesterol-ester formation, with mouse tissues showing relatively higher activity than those of other animals. The kidney, brain, and spleen of mice showed relatively higher capacities to form this ester compared to other tissues, and the enzyme activity was mainly localized in microsomal fractions. The CPIA-cholesterol ester did not seem to be produced by three known biosynthetic pathways of endogenous cholesterol esters--acyl-CoA:cholesterol O-acyltransferase (ACAT), lecithin:cholesterol O-acyltransferase (LCAT), and cholesterol esterase. Carboxyesterase(s) of mouse kidney microsomes solubilized by digitonin hydrolyzed only the B alpha-isomer of fenvalerate, yielding CPIA, whereas they yielded the corresponding cholesterol ester in the presence of artificial liposomes containing cholesterol. Thus, it appears that the stereoselective formation of the CPIA-cholesterol ester results from the stereoselective formation of the CPIA-carboxyesterase complex only from the B alpha-isomer, which subsequently undergoes cleavage by cholesterol to yield the CPIA-cholesterol ester.

Cholesteryl ester transfer protein genotype modifies the effect of apolipoprotein ε4 on memory decline in older adults.

PubMed

Sundermann, Erin Elizabeth; Wang, Cuiling; Katz, Mindy; Zimmerman, Molly E; Derby, Carol A; Hall, Charles B; Ozelius, Laurie J; Lipton, Richard B

2016-05-01

Apolipoprotein ε4 (ApoE4) is a strong genetic risk factor for sporadic Alzheimer's disease and memory decline in older adults. A single-nucleotide polymorphism in the cholesteryl ester transfer protein (CETP) gene (isoleucine to valine; V405) is associated with slower memory decline and a lower risk of Alzheimer's disease. As both genes regulate cholesterol, we hypothesized that the favorable CETPV405 allele may buffer the effect of ApoE4 on memory decline in older adults. Using linear regression, we examined the interactive effect of ApoE4 by CETPV405 on memory decline among 909 community-dwelling, nondemented, older adults (≥70 years) from the Einstein Aging Study. Episodic memory was measured using the picture version of the Free and Cued Selective Reminding Test with immediate recall (pFCSRT+IR). There was a significant ApoE × CETP interaction on decline in pFCSRT+IR scores (p = 0.01). ApoE4 carriers experienced faster decline than noncarriers among CETPI405I homozygotes (p = 0.007) and in CETPI405V heterozygotes (p = 0.015) but not in CETPV405V homozygotes (p = 0.614). Results suggest that the CETPV405 allele buffers ApoE4-associated memory decline in a gene dose-dependent manner. Copyright © 2016 Elsevier Inc. All rights reserved.

Hepatic cholesteryl ester metabolism in reptiles. A comparative study of three species of Brazilian lizards.

PubMed

Gillett, M P; Maia, M M

1984-01-01

Cholesterol esterase (CEase) and acylcoenzyme A: cholesterol acyltransferase (ACATase) activities were identified in liver cytoplasmatic extracts from Tropidurus torquatos (Iguanidae), Ameiva ameiva (Teiidae) and Hemidactylus mabouia (Gekkonidae). Optimum conditions were established to measure the hydrolytic activity of CEase and esterifying activities of CEase and ACATase. The activities of both enzymes were generally similar in all three species of reptiles, and did not differ greatly from values reported for a variety of mammalian species.

Proanthocyanidin-rich extract from grape seeds attenuates the development of aortic atherosclerosis in cholesterol-fed rabbits.

PubMed

Yamakoshi, J; Kataoka, S; Koga, T; Ariga, T

1999-01-01

The aim of this study was to evaluate the antiatherosclerotic effect of proanthocyanidin-rich extracts from grape seeds in cholesterol-fed rabbits. Proanthocyanidin-rich extracts (0.1% and 1% in diets [w/w]) did not appreciably affect the changes in serum lipid profile of cholesterol-fed rabbits. The level of cholesteryl ester hydroperoxides (ChE-OOH) induced by 2,2'-azobis(2-amidinopropane-dihydrochloride (AAPH) were lower in the plasma of rabbits fed proanthocyanidin-rich extract plus cholesterol than in the plasma of rabbits fed cholesterol alone, but not in the low-density lipoprotein (LDL). Aortic malondialdehyde (MDA) content decreased in rabbits fed proanthocyanidin-rich extract. Feeding proanthocyanidin-rich extracts (0.1 and 1% in the diet) to rabbits significantly reduced severe atherosclerosis in the aorta. Immunohistochemical analysis revealed a decrease in the number of oxidized LDL-positive macrophage-derived foam cells in atherosclerotic lesions in the aorta of rabbits fed proanthocyanidin-rich extract. When proanthocyanidin-rich extract was administered orally to rats, proanthocyanidin was detected in the plasma by Porters method but not in the lipoproteins (LDL plus VLDL). In an in vitro experiment using human plasma, proanthocyanidin-rich extract added to the plasma inhibited the oxidation of cholesteryl linoleate in LDL, but not in the LDL isolated after the plasma and the extract were incubated in advance. These results suggested that proanthocyanidins, the major polyphenols in red wine, might trap reactive oxygen species in aqueous series such as plasma and interstitial fluid of the arterial wall, thereby inhibiting oxidation of LDL and showing an antiatherosclerotic activity.

Steryl chlorin esters are formed by zooplankton herbivory

NASA Astrophysics Data System (ADS)

Harradine, Paul J.; Harris, Philip G.; Head, Robert N.; Harris, Roger P.; Maxwell, James R.

1996-06-01

Steryl chlorin esters (SCEs) were formed in laboratory feeding experiments when starved females of the copepod Calanus helgolandicus were allowed to graze on a culture of the diatom Thalassiosira weissflogii. They were found when the zooplankton had grazed for 48 hours and were also identified in fecal pellets subsequently left in seawater in the dark. The distribution contained the diatom sterols in approximately the same relative abundance as the free sterols in the substrate, as well as the most abundant copepod sterol, all esterified to the chlorophyll a degradation product, pyropheophorbide a. Hence, in studies aimed at using sedimentary SCE sterol distributions as indicators of phytoplankton community structure, cholesterol should not be considered since the cholesteryl ester of pyropheophorbide a was a significant component in the fecal pellet SCEs. The findings represent a step forward in unravelling the transformations undergone by chlorophyll a in aquatic environments, since the abundance and wide occurrence of sedimentary SCEs indicate that they are a significant preservational sink for the chlorophyll a biosynthesised in the photic zone.

Tear Film Lipids

PubMed Central

Butovich, Igor A.

2013-01-01

Human meibomian gland secretions (MGS, or meibum) are formed from a complex mixture of lipids of different classes such as wax esters, cholesteryl esters, (O-acyl)-ω-hydroxy fatty acids (OAHFA) and their esters, acylglycerols, diacylated diols, free fatty acids, cholesterol, and a smaller amount of other polar and nonpolar lipids, whose chemical nature and the very presence in MGS have been a matter of intense debates. The purpose of this review is to discuss recent results that were obtained using different experimental techniques, estimate limitations of their usability, and discuss their biochemical, biophysical, and physiological implications. To create a lipid map of MGS and tears, the results obtained in the author’s laboratory were integrated with available information on chemical composition of MGS and tears. The most informative approaches that are available today to researchers, such as HPLC-MS, GC-MS, and proton NMR, are discussed in details. A map of the meibomian lipidome (as it is seen in reverse phase liquid chromatography/mass spectrometry experiments) is presented. Directions of future efforts in the area are outlined. PMID:23769846

Oxidative tyrosylation of high density lipoprotein by peroxidase enhances cholesterol removal from cultured fibroblasts and macrophage foam cells.

PubMed Central

Francis, G A; Mendez, A J; Bierman, E L; Heinecke, J W

1993-01-01

Lipoprotein oxidation is thought to play a pivotal role in atherogenesis, yet the underlying reaction mechanisms remain poorly understood. We have explored the possibility that high density lipoprotein (HDL) might be oxidized by peroxidase-generated tyrosyl radical. Exposure of HDL to L-tyrosine, H2O2, and horseradish peroxidase crosslinked its apolipoproteins and strikingly increased protein-associated fluorescence. The reaction required L-tyrosine but was independent of free metal ions; it was blocked by either catalase or the heme poison aminotriazole. Dityrosine and other tyrosine oxidation products were detected in the apolipoproteins of HDL modified by the peroxidase/L-tyrosine/H2O2 system, implicating tyrosyl radical in the reaction pathway. Further evidence suggests that tyrosylated HDL removes cholesterol from cultured cells more effectively than does HDL. Tyrosylated HDL was more potent than HDL at inhibiting cholesterol esterification by the acyl-CoA:cholesterol acyltransferase reaction, stimulating the incorporation of [14C]acetate into [14C]cholesterol, and depleting cholesteryl ester stores in human skin fibroblasts. Moreover, exposure of mouse macrophage foam cells to tyrosylated HDL markedly diminished cholesteryl ester and free cholesterol mass. We have recently found that myeloperoxidase, a heme protein secreted by activated phagocytes, can also convert L-tyrosine to o,o'-dityrosine. This raises the possibility that myeloperoxidase-generated tyrosyl radical may modify HDL, enabling the lipoprotein to protect the artery wall against pathological cholesterol accumulation. Images Fig. 1 PMID:8341680

Role of Glycans in Cholesteryl Ester Transfer Protein revealed by MD simulation.

PubMed

Hao, Dongxiao; Yang, Zhiwei; Gao, Teng; Tian, Zhiqi; Zhang, Lei; Zhang, Shengli

2018-05-03

Current cholesteryl ester transfer protein (CETP) inhibitors are designed based on the unglycosylated crystal structure, and most of them have failed to cure cardiovascular disease (CVD). It is particularly important for us to investigate the glycosylation structure of CETP (CETP-G) and effect of glycans on the structure and function of CETP. Here, we used a total of 3.0-μs molecular dynamics trajectories of nascent structure of CETP (CETP-N) and CETP-G to study their structural differentiations, to shed new light on the CETP-mediated lipid exchange. In accordance with our simulations and previous mutation studies, relative to CETP-N, CETP-G adopts a more stretched shape with higher hydrophobic and hydrophilic SASA of N-terminal oscillating with larger amplitude, in which Glycan88 provides partial assistance for CEs through the N-terminal. Glycan341 reduces the flexibility of neck flap, with the interference of CEs through the neck region. Besides, Glycan240 reduces the flexibility of Helix-X to interfere the CEs transfer. Glycan396 decreases the flexibility and increases the hydrophobic SASA of C-terminal. Overall, these glycans affect the dynamics and structure of CETP through forming H-bonds with surrounding residues, and the sampled conformations of glycan is also affected by its surrounding residues. Thus, glycans are an integral part of CETP, further studies on the CETP inhibition and treatment of CVD should fully consider the effect of glycans. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

Liposome-based delivery of a boron-containing cholesteryl ester for high-LET particle-induced damage of prostate cancer cells: a boron neutron capture therapy study.

PubMed

Gifford, Ian; Vreeland, Wyatt; Grdanovska, Slavica; Burgett, Eric; Kalinich, John; Vergara, Vernieda; Wang, C-K Chris; Maimon, Eric; Poster, Dianne; Al-Sheikhly, Mohamad

2014-06-01

The efficacy of a boron-containing cholesteryl ester compound (BCH) as a boron neutron capture therapy (BNCT) agent for the targeted irradiation of PC-3 human prostate cancer cells was examined. Liposome-based delivery of BCH was quantified with inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC). Cytotoxicity of the BCH-containing liposomes was evaluated with neutral red, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), and lactate dehydrogenase assays. Colony formation assays were utilized to evaluate the decrease in cell survival due to high-linear energy transfer (LET) particles resulting from (10)B thermal neutron capture. BCH delivery by means of encapsulation in a lipid bilayer resulted in a boron uptake of 35.2 ± 4.3 μg/10(9) cells, with minimal cytotoxic effects. PC-3 cells treated with BCH and exposed to a 9.4 × 10(11) n/cm(2) thermal neutron fluence yielded a 20-25% decrease in clonogenic capacity. The decreased survival is attributed to the generation of high-LET α particles and (7)Li nuclei that deposit energy in densely ionizing radiation tracks. Liposome-based delivery of BCH is capable of introducing sufficient boron to PC-3 cells for BNCT. High-LET α particles and (7)Li nuclei generated from (10)B thermal neutron capture significantly decrease colony formation ability in the targeted PC-3 cells.

Hyperlipidemia and reproductive failure in captive-reared alligators: vitamin E, vitamin A, plasma lipids, fatty acids, and steroid hormones.

PubMed

Lance, V A; Morici, L A; Elsey, R M; Lund, E D; Place, A R

2001-02-01

Blood samples were collected from 26 captive-reared alligators (25 females; one male) and 12 (seven females and five males) wild "nuisance" alligators collected by wildlife personnel in south Louisiana in May 1995. The captive alligators, hatched from artificially incubated eggs in 1972-1973, had received vitamin E supplements during the 3 weeks before the blood sample was collected. Each sample was analyzed for vitamin E (alpha-tocopherol), vitamin A (retinol), total lipid, triacylglycerol, phospholipid, cholesterol, cholesteryl ester, free fatty acids, steroid hormones and a standard clinical blood panel. The fatty acid composition of the plasma lipid fraction was also analyzed. Results indicated that 18 of the captive females and three of the seven wild females were undergoing vitellogenesis, i.e. had elevated plasma estradiol and elevated plasma calcium. Vitellogenic females had higher vitamin E than non-vitellogenic females (77.4 microg/ml vs. 28.6 microg/ml in captive females; 24.0 microg/ml vs. 21 microg/ml in wild females). Plasma retinol was similar in all groups, ranging from 0.5 to 1.4 microg/ml and close to values reported in birds. All lipid fractions, with the exception of cholesteryl ester, were higher in captive alligators than in wild alligators. There were also significant differences in the fatty acid composition of wild and captive alligators. Plasma eicosapentaenoic and docasahexaenoic acid were higher in wild than in captive alligators, whereas linoleic was higher in captive than in wild.

Leoligin, the major lignan from Edelweiss, activates cholesteryl ester transfer protein

PubMed Central

Duwensee, Kristina; Schwaiger, Stefan; Tancevski, Ivan; Eller, Kathrin; van Eck, Miranda; Markt, Patrick; Linder, Tobias; Stanzl, Ursula; Ritsch, Andreas; Patsch, Josef R.; Schuster, Daniela; Stuppner, Hermann; Bernhard, David; Eller, Philipp

2011-01-01

Objective Cholesteryl ester transfer protein (CETP) plays a central role in the metabolism of high-density lipoprotein particles. Therefore, we searched for new drugs that bind to CETP and modulate its activity. Methods A preliminary pharmacophore-based parallel screening approach indicated that leoligin, a major lignan of Edelweiss (Leontopodium alpinum Cass.), might bind to CETP. Therefore we incubated leoligin ex vivo at different concentrations with human (n = 20) and rabbit plasma (n = 3), and quantified the CETP activity by fluorimeter. Probucol served as positive control. Furthermore, we dosed CETP transgenic mice with leoligin and vehicle control by oral gavage for 7 days and measured subsequently the in vivo modulation of CETP activity (n = 5 for each treatment group). Results In vitro, leoligin significantly activated CETP in human plasma at 100 pM (p = 0.023) and 1 nM (p = 0.042), respectively, whereas leoligin concentrations of 1 mM inhibited CETP activity (p = 0.012). The observed CETP activation was not species specific, as it was similar in magnitude for rabbit CETP. In vivo, there was also a higher CETP activity after oral dosage of CETP transgenic mice with leoligin (p = 0.015). There was no short-term toxicity apparent in mice treated with leoligin. Conclusion CETP agonism by leoligin appears to be safe and effective, and may prove to be a useful modality to alter high-density lipoprotein metabolism. PMID:21820657

Inhibition of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) prevents dietary cholesterol-associated steatosis by enhancing hepatic triglyceride mobilization.

PubMed

Alger, Heather M; Brown, J Mark; Sawyer, Janet K; Kelley, Kathryn L; Shah, Ramesh; Wilson, Martha D; Willingham, Mark C; Rudel, Lawrence L

2010-05-07

Acyl-CoA:cholesterol O-acyl transferase 2 (ACAT2) promotes cholesterol absorption by the intestine and the secretion of cholesteryl ester-enriched very low density lipoproteins by the liver. Paradoxically, mice lacking ACAT2 also exhibit mild hypertriglyceridemia. The present study addresses the unexpected role of ACAT2 in regulation of hepatic triglyceride (TG) metabolism. Mouse models of either complete genetic deficiency or pharmacological inhibition of ACAT2 were fed low fat diets containing various amounts of cholesterol to induce hepatic steatosis. Mice genetically lacking ACAT2 in both the intestine and the liver were dramatically protected against hepatic neutral lipid (TG and cholesteryl ester) accumulation, with the greatest differences occurring in situations where dietary cholesterol was elevated. Further studies demonstrated that liver-specific depletion of ACAT2 with antisense oligonucleotides prevents dietary cholesterol-associated hepatic steatosis both in an inbred mouse model of non-alcoholic fatty liver disease (SJL/J) and in a humanized hyperlipidemic mouse model (LDLr(-/-), apoB(100/100)). All mouse models of diminished ACAT2 function showed lowered hepatic triglyceride concentrations and higher plasma triglycerides secondary to increased hepatic secretion of TG into nascent very low density lipoproteins. This work demonstrates that inhibition of hepatic ACAT2 can prevent dietary cholesterol-driven hepatic steatosis in mice. These data provide the first evidence to suggest that ACAT2-specific inhibitors may hold unexpected therapeutic potential to treat both atherosclerosis and non-alcoholic fatty liver disease.

Low cholesteryl ester transfer protein (CETP) concentration but normal CETP activity in serum from patients with short-term hypothyroidism Lack of relationship to lipoprotein abnormalities.

PubMed

Dedecjus, Marek; Masson, David; Gautier, Thomas; de Barros, Jean-Paul Pais; Gambert, Philippe; Lewinski, Andrzej; Adamczewski, Zbigniew; Moulin, Philippe; Lagrost, Laurent

2003-05-01

Hypothyroidism is associated with a number of abnormalities in lipoprotein metabolism. Although alterations in neutral lipid exchanges among plasma lipoproteins might be one characteristic feature of hypothyroidism, a few human studies of cholesteryl ester transfer protein (CETP) activity have led to heterogeneous and fragmentary observations. The aim of the present study was to analyse the influence of short-term hypothyroidism on CETP activity, as well as on the structure and composition of lipoproteins. PATIENTS, DESIGN AND MEASUREMENTS: Sixty-six thyroidectomized patients were withdrawn from L-thyroxine (L-T4) treatment for 5 weeks. Subsequently, L-T4 therapy was reinstated for 2 months and patients were compared to 61 matched normolipidaemic controls. Serum CETP activity and mass concentration, serum lipids, apolipoproteins and lipoprotein size distribution were determined in the three groups. Serum CETP mass concentration was significantly decreased in short-term hypothyroid patients, as compared to control subjects (3.22 +/- 0.98 vs. 3.79 +/- 1.2 mg/l, respectively; P < 0.001), and the values were normalized during L-T4 therapy. The ability of endogenous serum lipoproteins to interact with CETP was normal in short-term hypothyroid patients. Concordant observations were made regardless of whether neutral lipid transfers were measured from high-density lipoproteins (HDL) toward apo B-containing lipoproteins or from liposomes toward HDL. The size distribution of HDL was significantly different in short-term hypothyroid patients, compared to either the control or treated subgroups, with significant higher proportions of large-sized HDL2b and HDL2a (HDL2b: 13.6 +/- 6.5% before vs. 8.5 +/- 4.2% during L-T4 therapy, P < 0.05; HDL2a, 33.0 +/- 7.0% before vs. 29.3 +/- 6.9% during L-T4 therapy, P < 0.05). Although serum CETP mass concentration correlated negatively with the HDL2 to HDL3 ratio in control subjects (r = -0.588; P < 0.0001), no significant correlations were observed in hypothyroid patients, regardless of whether they were treated or not. Similarly, whereas the previously recognized positive correlation of CETP mass concentration with serum LDL cholesterol levels was found in control subjects (r = 0.264; P < 0.05), no significant correlations appeared in treated and untreated patients. Short-term hypothyroidism may constitute an unique situation in which concomitant alterations in serum cholesteryl ester transfer protein concentration and lipoprotein parameters are disconnected.

Assessment of potential false positives via orbitrap-based untargeted lipidomics from rat tissues.

PubMed

Xu, Lina; Wang, Xueying; Jiao, Yupei; Liu, Xiaohui

2018-02-01

Untargeted lipidomics is increasingly popular due to the broad coverage of lipid species. Data dependent MS/MS acquisition is commonly used in order to acquire sufficient information for confident lipid assignment. However, although lipids are identified based on MS/MS confirmation, a number of false positives are still observed. Here, we discuss several causes of introducing lipid false identifications in untargeted analysis. Phosphotidylcholines and cholesteryl esters generate in-source fragmentation to produce dimethylated phosphotidylethanolamine and free cholesterol. Dimerization of fatty acid results in false identification of fatty acid ester of hydroxyl fatty acid. Realizing these false positives is able to improve confidence of results acquired from untargeted analysis. Besides, thresholds are established for lipids identified using LipidSearch v4.1.16 software to reduce unreliable results. Copyright © 2017 Elsevier B.V. All rights reserved.

Cholesteryl Ester Transfer Protein Intimately Involved in Dyslipidemia-Related Susceptibility to Cognitive Deficits in Type 2 Diabetic Patients.

PubMed

Sun, Jie; Cai, Rongrong; Huang, Rong; Wang, Pin; Tian, Sai; Sun, Haixia; Xia, Wenqing; Wang, Shaohua

2016-08-01

Cholesteryl ester transfer protein (CETP) is involved in diabetic dyslipidemia. We aim to test the hypothesis that CETP might be of importance in mediating dyslipidemia-related susceptibility to cognitive deficits in diabetic patients. We recruited 190 type 2 diabetic patients and divided them into two groups according to the Montreal Cognitive Assessment (MoCA) score. The association between CETP and cognitive decline was analyzed with logistic regression and stratification. There were 110 diabetic patients with mild cognition impairment (MCI) and 80 healthy cognition subjects as controls. Dyslipidemia is more common among diabetic patients with MCI; they had a significant increase of serum CETP concentrations, which was negatively correlated with MoCA (r = -0.638; p < 0.001). Negative correlations were also found between the serum CETP concentration with the Auditory Verbal Learning Test (r = -0.266; p = 0.008), indicating memory deficit. Logistic regression analysis revealed that CETP concentration was an independent factor of diabetic MCI (p < 0.001). Further stratification study showed that high serum levels of CETP was an independent risk factor of MCI in diabetic patients with a low density lipoproteins level ≥2.59 mmol/L, or high density lipoproteins level ≤1.0 mmol/L for men and ≤1.3 mmol/L for women, or TG level ≥1.7 mmol/L, after adjusting for age, sex, education, and glucose control (all ps < 0.05). CETP was intimately involved in dyslipidemia-related susceptibility to cognitive decline, especially memory function in type 2 diabetic patients.

Analysis of glomerulosclerosis and atherosclerosis in lecithin cholesterol acyltransferase-deficient mice.

PubMed

Lambert, G; Sakai, N; Vaisman, B L; Neufeld, E B; Marteyn, B; Chan, C C; Paigen, B; Lupia, E; Thomas, A; Striker, L J; Blanchette-Mackie, J; Csako, G; Brady, J N; Costello, R; Striker, G E; Remaley, A T; Brewer, H B; Santamarina-Fojo, S

2001-05-04

To evaluate the biochemical and molecular mechanisms leading to glomerulosclerosis and the variable development of atherosclerosis in patients with familial lecithin cholesterol acyl transferase (LCAT) deficiency, we generated LCAT knockout (KO) mice and cross-bred them with apolipoprotein (apo) E KO, low density lipoprotein receptor (LDLr) KO, and cholesteryl ester transfer protein transgenic mice. LCAT-KO mice had normochromic normocytic anemia with increased reticulocyte and target cell counts as well as decreased red blood cell osmotic fragility. A subset of LCAT-KO mice accumulated lipoprotein X and developed proteinuria and glomerulosclerosis characterized by mesangial cell proliferation, sclerosis, lipid accumulation, and deposition of electron dense material throughout the glomeruli. LCAT deficiency reduced the plasma high density lipoprotein (HDL) cholesterol (-70 to -94%) and non-HDL cholesterol (-48 to -85%) levels in control, apoE-KO, LDLr-KO, and cholesteryl ester transfer protein-Tg mice. Transcriptome and Western blot analysis demonstrated up-regulation of hepatic LDLr and apoE expression in LCAT-KO mice. Despite decreased HDL, aortic atherosclerosis was significantly reduced (-35% to -99%) in all mouse models with LCAT deficiency. Our studies indicate (i) that the plasma levels of apoB containing lipoproteins rather than HDL may determine the atherogenic risk of patients with hypoalphalipoproteinemia due to LCAT deficiency and (ii) a potential etiological role for lipoproteins X in the development of glomerulosclerosis in LCAT deficiency. The availability of LCAT-KO mice characterized by lipid, hematologic, and renal abnormalities similar to familial LCAT deficiency patients will permit future evaluation of LCAT gene transfer as a possible treatment for glomerulosclerosis in LCAT-deficient states.

Hydrolysis of phosphatidylcholine by hepatic lipase in discoidal and spheroidal recombinant high-density lipoprotein.

PubMed

Tansey, J T; Thuren, T Y; Jerome, W G; Hantgan, R R; Grant, K; Waite, M

1997-10-07

Hepatic lipase (HL) hydrolysis of phosphatidylcholine (PC) was studied in recombinant high-density lipoprotein particles (r-HDL). r-HDL were made from cholate mixed micelles that contained PC, apo AI, and, in some cases, unesterified cholesterol. r-HDL were characterized using chemical composition, nondenaturing gradient gel electrophoresis, transmission electron microscopy, and dynamic light scattering. The r-HDL were found to be discoidal and in the size range of native HDL. Upon treatment of cholesterol-containing r-HDL with lecithin-cholesterol acyltransferase (LCAT), to form cholesteryl ester, the discoidal r-HDL became spheroidal. The effects of r-HDL morphology and size on HL activity were studied on r-HDL made of palmitoyloleoyl-PC, unesterified cholesterol, cholesteryl ester, and apolipoprotein AI. Spheroidal r-HDL were hydrolyzed at a faster rate than discoidal r-HDL. Protein-poor r-HDL were hydrolyzed by HL at a faster rate than protein rich r-HDL. Unesterified cholesterol had no apparent effect on particle PC hydrolysis. The hydrolysis of different species of PC [dipalmitoyl (DPPC), dioleoyl(DOPC), palmitoylarachidonoyl (PAPC), and palmitoyloleoyl (POPC)] in r-HDL was also investigated. In discoidal r-HDL, we found that POPC >/= DOPC = PAPC/DPPC. However, in LCAT-treated spheroidal r-HDL, POPC = DOPC > PAPC/DPPC. In both discoidal and spheroidal rHDL, DPPC containing r-HDL were not hydrolyzed to a significant extent. Collectively, these studies demonstrate that the physico-chemical properties of particles (such as phospholipid packing and phospholipid acyl composition) play a significant role in hydrolysis of HDL phospholipid by HL and, therefore, in reverse cholesterol transport.

Uptake of gold- and [3H]cholesteryl linoleate-labeled human low density lipoprotein by cultured rat granulosa cells: cellular mechanisms involved in lipoprotein metabolism and their importance to steroidogenesis

PubMed Central

1985-01-01

We used electron microscopy, acid hydrolase cytochemistry, and biochemistry to analyze the uptake and metabolism of colloidal gold- and [3H]cholesteryl linoleate-labeled human low density lipoprotein (LDL) by cultured rat granulosa cells. The initial interaction of gold- LDL conjugates with granulosa cells occurred at binding sites diffusely distributed over the plasma membrane. After incubation with ligand in the cold, 99.9% of the conjugates were at the cell surface but less than 4% lay over coated pits. Uptake was specific since it was decreased 93-95% by excess unconjugated LDL and heparin, but only 34- 38% by excess unconjugated human high density lipoprotein. LDL uptake was related to granulosa cell differentiation; well-luteinized cells bound 2-3 times as much gold-LDL as did poorly luteinized cells. Ligand internalization was initiated by warming and involved coated pits, coated vesicles, pale multivesicular bodies (MVBs), dense MVBs, and lysosomes. A key event in this process was the translocation of gold- LDL conjugates from the cell periphery to the Golgi zone. This step was carried out by the pale MVB, a prelysosomal compartment that behaves like an endosome. Granulosa cells exposed to LDL labeled with gold and [3H]cholesteryl linoleate converted [3H]sterol to [3H]progestin in a time-dependent manner. This conversion was paralleled by increased gold- labeling of lysosomes and blocked by chloroquine, an inhibitor of lysosomal activity. In brief, granulosa cells deliver LDL to lysosomes by a receptor-mediated mechanism for the hydrolysis of cholesteryl esters. The resulting cholesterol is, in turn, transferred to other cellular compartments, where conversion to steroid occurs. These events comprise the pathway used by steroid-secreting cells to obtain the LDL- cholesterol vital for steroidogenesis. PMID:3920223

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.

Development of a self-emulsifying formulation that reduces the food effect for torcetrapib.

PubMed

Perlman, M E; Murdande, S B; Gumkowski, M J; Shah, T S; Rodricks, C M; Thornton-Manning, J; Freel, D; Erhart, L C

2008-03-03

Torcetrapib is a highly lipophilic (Clog P=7.45) and water insoluble cholesteryl ester transfer protein (CETP) inhibitor developed for the treatment of atherosclerosis. Self-emulsifying drug delivery system (SEDDS) formulations have been developed to reduce the food effect observed in early clinical trials using medium chain triglyceride (MCT) softgels and to increase the dose per capsule. MCT/Triacetin/Polysorbate 80/Capmul MCM (20/30/20/30) (MTPC) increased fasted exposure and thus reduced the food effect from 5- to 3-fold in dogs at a dose of 90 mg. Self-emulsifying formulations also accelerated absorption and generally decreased variability. Use of the lipophilic, GRAS cosolvent triacetin allowed a 2-fold increase in the dose per capsule. For the three formulations evaluated in dogs that showed significant differences in absorption, emulsion droplet size did not appear to play a significant role. Absorption did increase with Cremophor RH40 content, and at 50% Cremophor RH40 there was no food effect (at 30 mg). High polar surfactant content also resulted in poor dose proportionality, while there was good dose proportionality for MTPC. Studies of in vitro lipolysis are being conducted to aid in understanding the in vitro/in vivo relationships for torcetrapib SEDDS absorption.

Atomistic Simulation Studies of Cholesteryl Oleates: Model for the Core of Lipoprotein Particles

PubMed Central

Heikelä, Mikko; Vattulainen, Ilpo; Hyvönen, Marja T.

2006-01-01

We have conducted molecular dynamics simulations to gain insight into the atomic-scale properties of an isotropic system of cholesteryl oleate (CO) molecules. Cholesteryl esters are major constituents of low density lipoprotein particles, the key players in the formation of atherosclerosis, as well as the storage form of cholesterol. Here the aim is to clarify structural and dynamical properties of CO molecules under conditions, which are suggestive of those in the core of low density lipoprotein particles. The simulations in the fluid phase indicate that the system of CO molecules is characterized by an absence of translational order, as expected, while the orientational order between distinct CO molecules is significant at short distances, persisting over a molecular size. As for intramolecular properties, the bonds along the oleate chain are observed to be weakly ordered with respect to the sterol structure, unlike the bonds along the short hydrocarbon chain of cholesterol where the ordering is significant. The orientational distribution of the oleate chain as a whole with respect to the sterol moiety is of broad nature, having a major amount of extended and a less considerable proportion of bended structures. Distinct transient peaks at specific angles also appear. The diffusion of CO molecules is found to be a slow process and characterized by a diffusion coefficient of the order of 2 × 10−9 cm2/s. This is considerably slower than diffusion, e.g., in ordered domains of lipid membranes rich in sphingomyelin and cholesterol. Analysis of the rotational diffusion rates and trans-to-gauche transition rates yield results consistent with experiments. PMID:16399839

Umbilical venous-arterial plasma composition differences suggest differential incorporation of fatty acids in NEFA and cholesteryl ester pools.

PubMed

Lewis, Rohan M; Hanson, Mark A; Burdge, Graham C

2011-08-01

The developing fetus requires an adequate supply of fatty acids, in particular PUFA, for optimal growth and development. Little is known about the transfer of fatty acids by the placenta into the fetal circulation. However, the molecular form in which fatty acids are transferred into the fetal circulation may influence their metabolism and hence their availability to specific tissues. The aim of the present study was to determine which lipid pools in the fetal circulation become enriched in fatty acids from the placenta by comparing the fatty acid compositions of individual lipid pools between umbilical venous (UV) and umbilical arterial (UA) plasma. Plasma from the UV and UA was collected after delivery from ten uncomplicated pregnancies, and the fatty acid composition of each lipid class was determined by GC. Total NEFA concentration in the UV was twofold higher than in the UA (P < 0·05) due to enrichment in 16 : 0, 16 : 1n-7, 18 : 1n-9, 18 : 1n-7, 18 : 2n-6, 20 : 3n-6, 20 : 4n-6, 24 : 0 and 22 : 6n-3. Total cholesteryl ester concentration was twofold higher in the UV than in the UA (P < 0·05) due to enrichment in 16 : 0, 16 : 1n-7, 18 : 0, 18 : 1n-9, 18 : 1n-7, 18 : 2n-6 and 20 : 4n-6. There were no significant UV-UA differences in the total concentration or composition of TAG or phosphatidylcholine. The present study demonstrates differential enrichment across the placenta of fatty acids into specific lipid pools in the fetal circulation. Such partitioning may facilitate supply of individual fatty acids to specific fetal tissues.

Meta-analysis of cholesteryl ester transfer protein TaqIB polymorphism and risk of myocardial infarction.

PubMed

Cao, Min; Zhou, Zhi-Wen; Fang, Bang-Jiang; Zhao, Cheng-Gen; Zhou, Duan

2014-11-01

A number of studies have been conducted to explore the association between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism and risk of myocardial infarction (MI); however, the results are inconsistent. Therefore, we conducted this meta-analysis to clarify the issue based on all the data available.Eligible studies were retrieved by searching PubMed, Embase, Web of Science, and Google Scholar. We calculated the crude odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) to assess the association between the TaqIB polymorphism and risk of MI.We included 13 studies involving 8733 MI cases and 8573 controls in the meta-analysis. The pooled results from all included studies showed decreased MI risk in the analysis of the B2B2 versus B1B1 (OR = 0.78, 95% CI = 0.68-0.91), dominant (OR = 0.88, 95% CI = 0.77-0.99), and recessive genetic models (OR = 0.84, 95% CI = 0.78-0.91). The frequency of the B2B2 genotype in MI patients was lower (OR = 0.87, 95% CI = 0.81-0.94). However, there was no significant association in the B1B2 versus B1B1 analysis (OR = 0.92, 95% CI = 0.81-1.05) and no significant difference for the B1B1 genotype (OR = 1.04, 95% CI = 0.98-1.11) and B1B2 genotype (OR = 1.03, 95% CI = 0.97-1.08). Cumulative analysis confirmed these results.Our results suggest that the B2B2 genotype of the CETP TaqIB polymorphism is a protective factor against the development of MI.

Rationale and design of dal-PLAQUE: A study assessing efficacy and safety of dalcetrapib on progression or regression of atherosclerosis using magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography/computed tomography

PubMed Central

Fayad, Zahi A.; Mani, Venkatesh; Woodward, Mark; Kallend, David; Bansilal, Sameer; Pozza, Joseph; Burgess, Tracy; Fuster, Valentin; Rudd, James H. F.; Tawakol, Ahmed; Farkouh, Michael E.

2014-01-01

dal-PLAQUE is a placebo-controlled multicenter study designed to assess the effect of dalcetrapib on imaging measures of plaque inflammation and plaque burden. dal-PLAQUE is a multimodality imaging study in the context of the large dal-HEART Program. Decreased high-density lipoprotein cholesterol is linked to increased risk of coronary heart disease (CHD). Dalcetrapib, a compound that increases high-density lipoprotein cholesterol by modulating cholesteryl ester transfer protein, is being studied to assess if it can reduce the progression of atherosclerotic disease and thereby decrease cardiovascular morbidity and mortality. Patients with CHD or CHD-risk equivalents were randomized to receive 600 mg dalcetrapib or placebo daily for 24 months, in addition to conventional lipid-lowering medication and other medications for cardiovascular risk factors. The primary outcomes are the effect of dalcetrapib on 18F-fluorodeoxyglucose positron emission tomography target-to-background ratio after 6 months and magnetic resonance imaging (MRI) plaque burden (wall area, wall thickness, total vessel area, and wall area/total vessel area ratio) after 12 months. Secondary objectives include positron emission tomography target-to-background ratio at 3 months and MRI plaque burden at 6 and 24 months; plaque composition at 6, 12, and 24 months; and aortic compliance at 6 months. A tertiary objective is to examine the dynamic contrast-enhanced MRI parameters of plaque neovascularization. In total, 189 subjects entered screening, and 130 were randomized. dal-PLAQUE will provide important information on the effects of dalcetrapib on markers of inflammation and atherosclerotic plaque burden and, thereby, on the safety of cholesteryl ester transfer protein modulation with dalcetrapib. Results are expected in 2011. PMID:21835280

Myeloperoxidase-generated reactive nitrogen species convert LDL into an atherogenic form in vitro

PubMed Central

Podrez, Eugene A.; Schmitt, David; Hoff, Henry F.; Hazen, Stanley L.

1999-01-01

Oxidized LDL is implicated in atherosclerosis; however, the pathways that convert LDL into an atherogenic form in vivo are not established. Production of reactive nitrogen species may be one important pathway, since LDL recovered from human atherosclerotic aorta is enriched in nitrotyrosine. We now report that reactive nitrogen species generated by the MPO-H2O2-NO2– system of monocytes convert LDL into a form (NO2-LDL) that is avidly taken up and degraded by macrophages, leading to massive cholesterol deposition and foam cell formation, essential steps in lesion development. Incubation of LDL with isolated MPO, an H2O2-generating system, and nitrite (NO2–)— a major end-product of NO metabolism—resulted in nitration of apolipoprotein B 100 tyrosyl residues and initiation of LDL lipid peroxidation. The time course of LDL protein nitration and lipid peroxidation paralleled the acquisition of high-affinity, concentration-dependent, and saturable binding of NO2-LDL to human monocyte–derived macrophages and mouse peritoneal macrophages. LDL modification and conversion into a high-uptake form occurred in the absence of free metal ions, required NO2–, occurred at physiological levels of Cl–, and was inhibited by heme poisons, catalase, and BHT. Macrophage binding of NO2-LDL was specific and mediated by neither the LDL receptor nor the scavenger receptor class A type I. Exposure of macrophages to NO2-LDL promoted cholesteryl ester synthesis, intracellular cholesterol and cholesteryl ester accumulation, and foam cell formation. Collectively, these results identify MPO-generated reactive nitrogen species as a physiologically plausible pathway for converting LDL into an atherogenic form. PMID:10359564

Enhancement of High-Density Lipoprotein Cholesterol Functions by Encapsulation of Policosanol Exerts Anti-Senescence and Tissue Regeneration Effects Via Improvement of Anti-Glycation, Anti-Apoptosis, and Cholesteryl Ester Transfer Inhibition.

PubMed

Lim, So-Mang; Yoo, Jeong-Ah; Lee, Eun-Young; Cho, Kyung-Hyun

2016-02-01

Consumption of policosanol (PCO), a refined mixture of sugar cane wax alcohols, can elevate serum levels of high-density lipoprotein cholesterol (HDL-C), although the molecular mechanism is still unknown. To investigate the mechanism of action responsible for the anti-senescence effects of PCO on lipoprotein metabolism and HDL functionality, we synthesized reconstituted HDL (rHDL) containing PCO. Encapsulation of PCO by rHDL (PCO-rHDL) enhanced anti-oxidant activity against cupric ion-mediated low-density lipoprotein (LDL) oxidation. PCO-rHDL (final concentration, 9 μM PCO) showed more potent anti-oxidant activity than vitamin C treatment (final concentration, 100 μM). PCO-rHDL inhibited fructose-mediated glycation, which is a major pathological mechanism of diabetic complications, in a dose-dependent manner. PCO also showed cytoprotective effects in monocytes and macrophages with less triggering of apoptotic processes and reactive oxygen species (ROS) production in the presence of hydrogen peroxide (H2O2). PCO-rHDL strongly inhibited uptake of acetylated LDL into macrophages, which is an initial atherosclerotic process. Surprisingly, PCO-rHDL inhibited human serum cholesteryl ester transfer protein (CETP) activity by up to 47% (final concentration, 10 μM PCO). Subcutaneous injection of PCO-rHDL dose-dependently enhanced tissue regeneration activity by 2.4-fold and 3.6-fold compared to that of the phosphate-buffered saline (PBS) control. In conclusion, PCO in HDL showed potent anti-oxidant, anti-glycation, and CETP inhibitory activities along with tissue regenerative activity, especially upon incorporation into HDL. These results suggest that PCO can enhance functionality of HDL in serum to exert anti-senescence and longevity effects.

Single dose pharmacokinetics, pharmacodynamics, tolerability and safety of BAY 60-5521, a potent inhibitor of cholesteryl ester transfer protein.

PubMed

Boettcher, Michael-Friedrich; Heinig, Roland; Schmeck, Carsten; Kohlsdorfer, Christian; Ludwig, Matthias; Schaefer, Anja; Gelfert-Peukert, Sabine; Wensing, Georg; Weber, Olaf

2012-02-01

To determine pharmacokinetics (PK), pharmacodynamics (PD), tolerability and safety of BAY 60-5521, a potent inhibitor of cholesteryl ester transfer protein (CETP). The first in man (FIM) study investigated the safety, tolerability, pharmacodynamics and pharmacokinetics in healthy male subjects following administration of single oral doses. The study was performed using a randomized, single-blind, placebo-controlled, single dose-escalation design. Thirty-eight young healthy male subjects (aged 20-45 years) received an oral dose of 5, 12.5, 25 or 50 mg BAY 60-5521 (n= 28) or were treated with a placebo (n= 10). In all four dose steps, only one adverse event (25 mg; mild skin rash) was considered drug related. Clinical laboratory parameters showed no clinically relevant changes. A clear dose-dependent CETP inhibition could be demonstrated starting at a dose of 5 mg. At a dose of 25 mg, a CETP inhibition >50% over 18 h was observed. After 50 mg, CETP inhibition >50% lasted more than 50 h. Twenty-four h after administration mean HDL-C-values showed a nearly dose-proportional increase. Following administration of 50 mg, a significant HDL-C increase of about 30% relative to baseline values was found. BAY 60-5521 was slowly absorbed reaching maximum concentrations in plasma after 4 to 6 h. The disposition in plasma was multi-exponential with an estimated mean terminal half-life of 76 to 144 h. BAY 60-5521 was clinically safe and well tolerated. No effects on heart rate, blood pressure and ECG recordings were observed during the study. A clear pharmacodynamic effect on CETP inhibition and HDL could be demonstrated. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

Development of mannose functionalized dendrimeric nanoparticles for targeted delivery to macrophages: use of this platform to modulate atherosclerosis.

PubMed

He, Hongliang; Yuan, Quan; Bie, Jinghua; Wallace, Ryan L; Yannie, Paul J; Wang, Jing; Lancina, Michael G; Zolotarskaya, Olga Yu; Korzun, William; Yang, Hu; Ghosh, Shobha

2018-03-01

Dysfunctional macrophages underlie the development of several diseases including atherosclerosis where accumulation of cholesteryl esters and persistent inflammation are 2 of the critical macrophage processes that regulate the progression as well as stability of atherosclerotic plaques. Ligand-dependent activation of liver-x-receptor (LXR) not only enhances mobilization of stored cholesteryl ester but also exerts anti-inflammatory effects mediated via trans-repression of proinflammatory transcription factor nuclear factor kappa B. However, increased hepatic lipogenesis by systemic administration of LXR ligands (LXR-L) has precluded their therapeutic use. The objective of the present study was to devise a strategy to selectively deliver LXR-L to atherosclerotic plaque-associated macrophages while limiting hepatic uptake. Mannose-functionalized dendrimeric nanoparticles (mDNP) were synthesized to facilitate active uptake via the mannose receptor expressed exclusively by macrophages using polyamidoamine dendrimer. Terminal amine groups were used to conjugate mannose and LXR-L T091317 via polyethylene glycol spacers. mDNP-LXR-L was effectively taken up by macrophages (and not by hepatocytes), increased expression of LXR target genes (ABCA1/ABCG1), and enhanced cholesterol efflux. When administered intravenously to LDLR-/- mice with established plaques, significant accumulation of fluorescently labeled mDNP-LXR-L was seen in atherosclerotic plaque-associated macrophages. Four weekly injections of mDNP-LXR-L led to significant reduction in atherosclerotic plaque progression, plaque necrosis, and plaque inflammation as assessed by expression of nuclear factor kappa B target gene matrix metalloproteinase 9; no increase in hepatic lipogenic genes or plasma lipids was observed. These studies validate the development of a macrophage-specific delivery platform for the delivery of anti-atherosclerotic agents directly to the plaque-associated macrophages to attenuate plaque burden. Copyright © 2017 Elsevier Inc. All rights reserved.

Weight Loss and Exercise Alter the High-Density Lipoprotein Lipidome and Improve High-Density Lipoprotein Functionality in Metabolic Syndrome.

PubMed

Khan, Anmar A; Mundra, Piyushkumar A; Straznicky, Nora E; Nestel, Paul J; Wong, Gerard; Tan, Ricardo; Huynh, Kevin; Ng, Theodore W; Mellett, Natalie A; Weir, Jacquelyn M; Barlow, Christopher K; Alshehry, Zahir H; Lambert, Gavin W; Kingwell, Bronwyn A; Meikle, Peter J

2018-02-01

High-density lipoprotein (HDL) lipid composition and function may better reflect cardiovascular risk than HDL cholesterol concentration. This study characterized the relationships between HDL composition, metabolism, and function in metabolic syndrome (MetS) patients and how changes in composition after weight loss (WL) and exercise treatments are related to function. Plasma samples from MetS patients (n=95) and healthy individuals (n=40) were used in this study. Subsets of the MetS group underwent 12 weeks of no treatment (n=17), WL (n=19), or WL plus exercise (WLEX; n=17). HDL was isolated using density-gradient ultracentrifugation. The HDL lipidome was analyzed by mass spectrometry, and particle size determined by nuclear magnetic resonance. Cholesteryl ester transfer protein activity and ex vivo HDL cholesterol efflux capacity (CEC) were assessed. The HDL lipidome in the MetS patients was substantially different from that in healthy individuals, mean particle size was smaller, and CEC was lower. Several HDL phospholipid and sphingolipid species were associated with HDL diameter and CEC. The HDL lipidome and particle size were modified toward the healthy individuals after WL and WLEX treatments, with greater effects observed in the latter group. Cholesteryl ester transfer protein activity was reduced after WL and WLEX, and CEC was improved after WLEX. WLEX treatment in MetS patients normalizes the HDL lipidome and particle size profile and enhances CEC. HDL lipids associated with diminished CEC may represent novel biomarkers for early prediction of HDL dysfunction and disease risk and may represent potential therapeutic targets for future HDL therapies. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00163943. © 2017 American Heart Association, Inc.

Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins.

PubMed

Gillard, Baiba K; Rosales, Corina; Xu, Bingqing; Gotto, Antonio M; Pownall, Henry J

2018-04-12

Human plasma high-density lipoprotein cholesterol concentrations are a negative risk factor for atherosclerosis-linked cardiovascular disease. Pharmacological attempts to reduce atherosclerotic cardiovascular disease by increasing plasma high-density lipoprotein cholesterol have been disappointing so that recent research has shifted from HDL quantity to HDL quality, that is, functional vs dysfunctional HDL. HDL has varying degrees of dysfunction reflected in impaired reverse cholesterol transport (RCT). In the context of atheroprotection, RCT occurs by 2 mechanisms: one is the well-known trans-hepatic pathway comprising macrophage free cholesterol (FC) efflux, which produces early forms of FC-rich nascent HDL (nHDL). Lecithin:cholesterol acyltransferase converts HDL-FC to HDL-cholesteryl ester while converting nHDL from a disc to a mature spherical HDL, which transfers its cholesteryl ester to the hepatic HDL receptor, scavenger receptor B1 for uptake, conversion to bile salts, or transfer to the intestine for excretion. Although widely cited, current evidence suggests that this is a minor pathway and that most HDL-FC and nHDL-FC rapidly transfer directly to the liver independent of lecithin:cholesterol acyltransferase activity. A small fraction of plasma HDL-FC enters the trans-intestinal efflux pathway comprising direct FC transfer to the intestine. SR-B1 -/- mice, which have impaired trans-hepatic FC transport, are characterized by high plasma levels of a dysfunctional FC-rich HDL that increases plasma FC bioavailability in a way that produces whole-body hypercholesterolemia and multiple pathologies. The design of future therapeutic strategies to improve RCT will have to be formulated in the context of these dual RCT mechanisms and the role of FC bioavailability. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Atherogenic impact of lecithin-cholesterol acyltransferase and its relation to cholesterol esterification rate in HDL (FER(HDL)) and AIP [log(TG/HDL-C)] biomarkers: the butterfly effect?

PubMed

Dobiášová, M

2017-05-04

The atherogenic impact and functional capacity of LCAT was studied and discussed over a half century. This review aims to clarify the key points that may affect the final decision on whether LCAT is an anti-atherogenic or atherogenic factor. There are three main processes involving the efflux of free cholesterol from peripheral cells, LCAT action in intravascular pool where cholesterol esterification rate is under the control of HDL, LDL and VLDL subpopulations, and finally the destination of newly produced cholesteryl esters either to the catabolism in liver or to a futile cycle with apoB lipoproteins. The functionality of LCAT substantially depends on its mass together with the composition of the phospholipid bilayer as well as the saturation and the length of fatty acyls and other effectors about which we know yet nothing. Over the years, LCAT puzzle has been significantly supplemented but yet not so satisfactory as to enable how to manipulate LCAT in order to prevent cardiometabolic events. It reminds the butterfly effect when only a moderate change in the process of transformation free cholesterol to cholesteryl esters may cause a crucial turn in the intended target. On the other hand, two biomarkers - FER(HDL) (fractional esterification rate in HDL) and AIP [log(TG/HDL-C)] can offer a benefit to identify the risk of cardiovascular disease (CVD). They both reflect the rate of cholesterol esterification by LCAT and the composition of lipoprotein subpopulations that controls this rate. In clinical practice, AIP can be calculated from the routine lipid profile with help of AIP calculator www.biomed.cas.cz/fgu/aip/calculator.php.

Specificity of lecithin:cholesterol acyltransferase and atherogenic risk: comparative studies on the plasma composition and in vitro synthesis of cholesteryl esters in 14 vertebrate species.

PubMed

Liu, M; Bagdade, J D; Subbaiah, P V

1995-08-01

To determine whether the specificity of lecithin: cholesterol acyltransferase (LCAT) influences the susceptibility to atherosclerosis, we compared the composition and in vitro synthesis of cholesteryl ester (CE) in the plasmas of 14 vertebrate species with varying predisposition to atherosclerosis. The susceptible species (Group I) had significantly higher ratios of 16:0 CE/20:4 CE in their plasma than the resistant species (Group II). The in vitro formation of labeled CE species in native plasma from labeled cholesterol correlated highly with the mass composition, showing that the LCAT reaction is the predominant source of plasma CE in all the animal species examined. Isolated LCATs from Group I species also synthesized CE with higher ratios of 16:0/20:4 than LCATs from Group II when egg phosphatidylcholine (PC) was used as the acyl donor. In addition, the Group I LCATs exhibited lower specificity towards sn-2-20:4 and sn-2-22:6 PCs, and higher specificity towards sn-2-18:2 PC species than Group II LCATs. With 16:0-20:4 PC as the substrate, all Group I LCATs synthesized more 16:0 CE than 20:4 CE, whereas all Group II LCATs, with the exception of dog enzyme, synthesized predominantly 20:4 CE, showing that the two types of LCAT have different positional specificities towards this PC. These results suggest that there are two classes of LCAT in nature that differ from each other in their substrate and positional specificities, possibly because of differences in their active-site architectures. We propose that the presence of one type of LCAT, which cannot efficiently transfer certain long chain polyunsaturated acyl groups and which consequently synthesizes more saturated CE, may increase the risk of atherosclerosis.

Effects of Lycopene on the Initial State of Atherosclerosis in New Zealand White (NZW) Rabbits

PubMed Central

Lorenz, Mario; Fechner, Mandy; Kalkowski, Janine; Fröhlich, Kati; Trautmann, Anne; Böhm, Volker; Liebisch, Gerhard; Lehneis, Stefan; Schmitz, Gerd; Ludwig, Antje; Baumann, Gert; Stangl, Karl; Stangl, Verena

2012-01-01

Background Lycopene is the main carotenoid in tomatoes, where it is found in high concentrations. Strong epidemiological evidence suggests that lycopene may provide protection against cardiovascular diseases. We therefore studied the effects of lycopene on diet-induced increase in serum lipid levels and the initiation of atherosclerosis in New Zealand White (NZW) rabbits. Methodology/Principal Findings The animals, divided into four groups of 9 animals each, were fed either a standard diet, a high-cholesterol diet containing 0.5% cholesterol, a high-cholesterol diet containing placebo beadlets, or a high-cholesterol diet plus 5 mg/kg body weight/day of lycopene (in the form of lycopene beadlets), for a period of 4 weeks. We found significantly elevated lycopene plasma levels in the animal group treated with lycopene beadlets. Compared to the high-cholesterol and the placebo group, this was associated with a significant reduction of 50% in total cholesterol and LDL cholesterol serum levels in the lycopene group. The amount of cholesteryl ester in the aorta was significantly decreased by lycopene. However, we did not observe a significant decrease in the extent of aortic surface lipid accumulation in the lycopene group. In addition, no differences in the intima-media thickness among groups were observed. Endothelial-dependent and endothelial-independent vasodilation in isolated rabbit aortic and carotid rings did not differ among any of the animal groups. Conclusions Lycopene supplementation for 4 weeks increased lycopene plasma levels in the animals. Although we found strongly reduced total and LDL cholesterol serum levels as well as significantly lower amounts of cholesteryl ester in the aortae in the lycopene-treated group, no significant differences in initial lesions in the aortae were detected. PMID:22295112

Combined thin layer chromatography and gas chromatography with mass spectrometric analysis of lipid classes and fatty acids in malnourished polar bears (Ursus maritimus) which swam to Iceland.

PubMed

Eibler, Dorothee; Krüger, Sabine; Skírnisson, Karl; Vetter, Walter

2017-03-01

Between 2008 and 2011, four polar bears (Ursus maritimus) from the Greenland population swam and/or drifted on ice to Iceland where they arrived in very poor body condition. Body fat resources in these animals were only between 0% and 10% of the body weight (usually 25%). Here we studied the lipid composition in different tissues (adipose tissue if available, liver, kidney and muscle). Lipid classes were determined by thin layer chromatography (TLC) and on-column gas chromatography with mass spectrometry (GC/MS). The fatty acid pattern of total lipids and free fatty acids was analyzed by GC/MS in selected ion monitoring (SIM) mode. Additionally, cholesteryl esters and native fatty acid methyl esters, initially detected as zones in thin layer chromatograms, were enriched by solid phase extraction and quantified by GC/MS. The ratio of free fatty acids to native fatty acid methyl esters could be correlated with the remained body lipids in the polar bears and thus may also serve as a marker for other starving animals or even for humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of triglyceride metabolism. I. Eukaryotic neutral lipid synthesis: "Many ways to skin ACAT or a DGAT".

PubMed

Turkish, Aaron; Sturley, Stephen L

2007-04-01

Esterification of sterols, fatty acids and other alcohols into biologically inert forms conserves lipid resources for many cellular functions. Paradoxically, the accumulation of neutral lipids such as cholesteryl ester or triglyceride, is linked to several major disease pathologies. In a remarkable example of genetic expansion, there are at least eleven acyltransferase reactions that lead to neutral lipid production. In this review, we speculate that the complexity and apparent redundancy of neutral lipid synthesis may actually hasten rather than impede the development of novel, isoform-specific, therapeutic interventions for acne, type 2 diabetes, obesity, hyperlipidemia, fatty liver disease, and atherosclerosis.

Atheroprotective potentials of curcuminoids against ginger extract in hypercholesterolaemic rabbits.

PubMed

Elseweidy, M M; Younis, N N; Elswefy, S E; Abdallah, F R; El-Dahmy, S I; Elnagar, G; Kassem, H M

2015-01-01

The anti-atherogenic potentials of total ginger (Zingiber officinale) extract (TGE) or curcuminoids extracted from turmeric (Curcuma longa), members of family Zingiberaceae, were compared in hypercholesterolaemia. Rabbits were fed either normal or atherogenic diet. The rabbits on atherogenic diet received treatments with TGE or curcumenoids and placebo concurrently for 6 weeks (n = 6). The anti-atherogenic effects of curcuminoids and ginger are mediated via multiple mechanisms. This effect was correlated with their ability to lower cholesteryl ester transfer protein activity. Ginger extract exerted preferential effects on plasma lipids, reverse cholesterol transport, cholesterol synthesis and inflammatory status. Curcuminoids, however, showed superior antioxidant activity.

Intracellular trafficking of the free cholesterol derived from LDL cholesteryl ester is defective in vivo in Niemann-Pick C disease: insights on normal metabolism of HDL and LDL gained from the NP-C mutation.

PubMed

Shamburek, R D; Pentchev, P G; Zech, L A; Blanchette-Mackie, J; Carstea, E D; VandenBroek, J M; Cooper, P S; Neufeld, E B; Phair, R D; Brewer, H B; Brady, R O; Schwartz, C C

1997-12-01

Niemann-Pick C disease (NP-C) is a rare inborn error of metabolism with hepatic involvement and neurological sequelae that usually manifest in childhood. Although in vitro studies have shown that the lysosomal distribution of LDL-derived cholesterol is defective in cultured cells of NP-C subjects, no unusual characteristics mark the plasma lipoprotein profiles. We set out to determine whether anomalies exist in vivo in the cellular distribution of newly synthesized, HDL-derived or LDL-derived cholesterol under physiologic conditions in NP-C subjects. Three affected and three normal male subjects were administered [14C]mevalonate as a tracer of newly synthesized cholesterol and [3H]cholesteryl linoleate in either HDL or LDL to trace the distribution of lipoprotein-derived free cholesterol. The rate of appearance of free [14C]- and free [3H]cholesterol in the plasma membrane was detected indirectly by monitoring their appearance in plasma and bile. The plasma disappearance of [3H]cholesteryl linoleate was slightly faster in NP-C subjects regardless of its lipoprotein origin. Appearance of free [14C] cholesterol ill the plasma (and in bile) was essentially identical in normal and affected individuals as was the initial appearance of free [3H]cholesterol derived from HDL, observed before extensive exchange occurred of the [3H]cholesteryl linoleate among lipoproteins. In contrast, the rate of appearance of LDL-derived free [3H]cholesterol in the plasma membrane of NP-C subjects, as detected in plasma and bile, was retarded to a similar extent that LDL cholesterol metabolism was defective in cultured fibroblasts of these affected subjects. These findings show that intracellular distribution of both newly synthesized and HDL-derived cholesterol are essentially unperturbed by the NP-C mutation, and therefore occur by lysosomal-independent paths. In contrast, in NP-C there is defective trafficking of LDL-derived cholesterol to the plasma membrane in vivo as well as in vitro. The in vivo assay of intracellular cholesterol distribution developed herein should prove useful to quickly evaluate therapeutic interventions for NP-C.

Self assembling bioactive materials for cell adhesion in tissue repair

NASA Astrophysics Data System (ADS)

Hwang, Julia J.

This work involved the study of biodegradable and biocompatible materials that have the potential to modify tissue engineering scaffolds through self assembly, generating multiple layers that deliver bioactivity. Diblock biomaterials containing cholesteryl moieties and oligomers of lactic acid units were found to form single crystals when precipitated from hot ethanol and smectic liquid crystalline phases when cast as a film. Cell culture experiments on these films with 3T3 and 3T6 fibroblasts indicated that these ordered materials form surfaces with specific chemistries that favored cell adhesion, spreading, and proliferation suggesting the potential of mediating human tissue repair. The author believes the cholesteryl moieties found on the surface play a key role in determining cell behavior. Cholesteryl-(L-lactic acid) diblock molecules were then functionalized with moieties including vitamin Bx, cholesterol, and the anti-inflammatory drug indomethacin. An unstable activated ester between indomethacin and the diblock molecule resulted in the release of indomethacin into the culture medium which inhibited the proliferation of 3T3 fibroblasts. Finally, a series of molecules were designed to incorporate dendrons based on amino acids at the termini of the diblock structures. It was determined that lysine, a basic amino acid, covalently coupled to cholesteryl-(L-lactic acid) can promote cell adhesion and spreading while negatively charged and zwitterionic 2nd generation dendrons based on aspartic acid do not. Incorporation of the well known arginine-glycine-aspartic acid (RGD) sequence, which is found in many adhesive proteins, to the dendrons imparted integrin-mediated cell adhesion as evidenced by the formation of stress fibers. We also explored the capacity of integrin receptors to bind to ligands that are not the linear form of RGD, but have R, G, and D spatially positioned to mimic the linear RGD environments. For this purpose, the arms of the 2 nd generation lysine dendrons were functionalized with R, G, and D to yield an 'R,G,D library' of molecules. These materials were found to promote adhesion of 3T3 fibroblasts through integrin receptors. A dendron is multifunctional and allows a large degree of functionality in chemical design.

Free cholesterol and cholesterol esters in bovine oocytes: Implications in survival and membrane raft organization after cryopreservation

PubMed Central

Ríos, Glenda L.; Canizo, Jesica R.; Antollini, Silvia S.; Alberio, Ricardo H.

2017-01-01

Part of the damage caused by cryopreservation of mammalian oocytes occurs at the plasma membrane. The addition of cholesterol to cell membranes as a strategy to make it more tolerant to cryopreservation has been little addressed in oocytes. In order to increase the survival of bovine oocytes after cryopreservation, we proposed not only to increase cholesterol level of oocyte membranes before vitrification but also to remove the added cholesterol after warming, thus recovering its original level. Results from our study showed that modulation of membrane cholesterol by methyl-β-cyclodextrin (MβCD) did not affect the apoptotic status of oocytes and improved viability after vitrification yielding levels of apoptosis closer to those of fresh oocytes. Fluorometric measurements based on an enzyme-coupled reaction that detects both free cholesterol (membrane) and cholesteryl esters (stored in lipid droplets), revealed that oocytes and cumulus cells present different levels of cholesterol depending on the seasonal period. Variations at membrane cholesterol level of oocytes were enough to account for the differences found in total cholesterol. Differences found in total cholesterol of cumulus cells were explained by the differences found in both the content of membrane cholesterol and of cholesterol esters. Cholesterol was incorporated into the oocyte plasma membrane as evidenced by comparative labeling of a fluorescent cholesterol. Oocytes and cumulus cells increased membrane cholesterol after incubation with MβCD/cholesterol and recovered their original level after cholesterol removal, regardless of the season. Finally, we evaluated the effect of vitrification on the putative raft molecule GM1. Cholesterol modulation also preserved membrane organization by maintaining ganglioside level at the plasma membrane. Results suggest a distinctive cholesterol metabolic status of cumulus-oocyte complexes (COCs) among seasons and a dynamic organizational structure of cholesterol homeostasis within the COC. Modulation of membrane cholesterol by MβCD improved survival of bovine oocytes and preserved integrity of GM1-related rafts after vitrification. PMID:28686720

Distribution of fatty acids from dietary oils into phospholipid classes of triacylglycerol-rich lipoproteins in healthy subjects.

PubMed

Abia, Rocio; Pacheco, Yolanda M; Montero, Emilio; Ruiz-Gutierrez, Valentina; Muriana, Francisco J G

2003-02-21

Several studies have suggested that lipoprotein metabolism can be affected by lipoprotein phospholipid composition. We investigated the effect of virgin olive oil (VOO) and high-oleic sunflower oil (HOSO) intake on the distribution of fatty acids in triacylglycerols (TG), cholesteryl esters (CE) and phospholipid (PL) classes of triacylglycerol-rich lipoproteins (TRL) from normolipidemic males throughout a 7 h postprandial metabolism. Particularly, changes in oleic acid (18:1n-9) concentration of PL were used as a marker of in vivo hydrolysis of TRL external monolayer. Both oils equally promoted the incorporation of oleic acid into the TG and CE of postprandial TRL. However, PL was enriched in oleic acid (18:1n-9) and n-3 polyunsaturated fatty acids (PUFA) after VOO meal, whereas in stearic (18:0) and linoleic (18:2n-6) acids after HOSO meal. We also found that VOO produced TRL which PL 18:1n-9 content was dramatically reduced along the postprandial period. We conclude that the fatty acid composition of PL can be a crucial determinant for the clearance of TRL during the postprandial metabolism of fats.

Lowering Effects of Onion Intake on Oxidative Stress Biomarkers in Streptozotocin-Induced Diabetic Rats

PubMed Central

Azuma, Keiko; Minami, Yuko; Ippoushi, Katsunari; Terao, Junji

2007-01-01

The protective effect of onion against oxidative stress in streptozotosin-induced diabetic rats was investigated in comparison with that of quercetin aglycone. We measured oxidative stress biomarkers involving the susceptibility of the plasma against copper ion-induced lipid peroxidation, which was estimated by the amounts of thiobarbituric acid-reactive substances (TBARS) and cholesteryl ester hydroperoxides, and urine TBARS and 8-hydroxydeoxyguanosine contents. After the 12-week feeding period, plasma glucose levels and these biomarkers increased in diabetic rats compared to normal rats. In diabetic rats fed a 6.0% onion diet (quercetin equivalent: 0.023%), quercetin metabolites accumulated in the plasma at concentrations of approximately 35 µM. Onion intake decreased plasma glucose levels and lowered the oxidative stress biomarkers. On the other hand, quercetin metabolites in the plasma of rats fed a diet with 0.023% quercetin aglycone were found at lower concentrations (14.2 µM) than the rats fed the onion diet. Furthermore, oxidative stress biomarkers were higher in the quercetin diet group compared to the onion diet group. These results strongly suggest that onion intake suppresses diabetes-induced oxidative stress more effectively than the intake of the same amount of quercetin aglycone alone. PMID:18188415

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use.

PubMed

Manual Kollareth, Denny Joseph; Chang, Chuchun L; Hansen, Inge H; Deckelbaum, Richard J

2018-03-01

Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [ 3 H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [ 3 H]cholesteryl oleoyl ether and [ 3 H]cholesteryl hexadecyl ether from different suppliers, employing in vitro , in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro , in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments.

Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport

PubMed Central

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

2015-01-01

Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann–Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. PMID:27330304

Inhibition of cholesterol absorption associated with a PPAR alpha-dependent increase in ABC binding cassette transporter A1 in mice.

PubMed

Knight, Brian L; Patel, Dilip D; Humphreys, Sandy M; Wiggins, David; Gibbons, Geoffrey F

2003-11-01

Dietary supplementation with the peroxisome proliferator-activated receptor alpha (PPAR alpha) ligand WY 14,643 gave rise to a 4- to 5-fold increase in the expression of mRNA for the ATP binding cassette transporter A1 (ABCA1) in the intestine of normal mice. There was no effect in the intestine of PPAR alpha-null mice. Consumption of a high-cholesterol diet also increased intestinal ABCA1 expression. The effects of WY 14,643 and the high-cholesterol diet were not additive. WY 14,643 feeding reduced intestinal absorption of cholesterol in the normal mice, irrespective of the dietary cholesterol concentration, and this resulted in lower diet-derived cholesterol and cholesteryl ester concentrations in plasma and liver. At each concentration of dietary cholesterol, there was a similar significant inverse correlation between intestinal ABCA1 mRNA content and the amount of cholesterol absorbed. The fibrate-induced changes in the intestines of the normal mice were accompanied by an increased concentration of the mRNA encoding the sterol-regulatory element binding protein-1c gene (SREBP-1c), a known target gene for the oxysterol receptor liver X receptor alpha (LXR alpha). There was a correlation between intestinal ABCA1 mRNA and SREBP-1c mRNA contents, but not between SREBP-1c mRNA content and cholesterol absorption. These results suggest that PPAR alpha influences cholesterol absorption through modulating ABCA1 activity in the intestine by a mechanism involving LXR alpha.

Fatty acid methyl ester profiles of bat wing surface lipids.

PubMed

Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

2014-11-01

Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

Meta-analysis of Cholesteryl Ester Transfer Protein TaqIB Polymorphism and Risk of Myocardial Infarction

PubMed Central

Cao, Min; Zhou, Zhi-Wen; Fang, Bang-Jiang; Zhao, Cheng-Gen; Zhou, Duan

2014-01-01

Abstract A number of studies have been conducted to explore the association between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism and risk of myocardial infarction (MI); however, the results are inconsistent. Therefore, we conducted this meta-analysis to clarify the issue based on all the data available. Eligible studies were retrieved by searching PubMed, Embase, Web of Science, and Google Scholar. We calculated the crude odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) to assess the association between the TaqIB polymorphism and risk of MI. We included 13 studies involving 8733 MI cases and 8573 controls in the meta-analysis. The pooled results from all included studies showed decreased MI risk in the analysis of the B2B2 versus B1B1 (OR = 0.78, 95% CI = 0.68–0.91), dominant (OR = 0.88, 95% CI = 0.77–0.99), and recessive genetic models (OR = 0.84, 95% CI = 0.78–0.91). The frequency of the B2B2 genotype in MI patients was lower (OR = 0.87, 95% CI = 0.81–0.94). However, there was no significant association in the B1B2 versus B1B1 analysis (OR = 0.92, 95% CI = 0.81–1.05) and no significant difference for the B1B1 genotype (OR = 1.04, 95% CI = 0.98–1.11) and B1B2 genotype (OR = 1.03, 95% CI = 0.97–1.08). Cumulative analysis confirmed these results. Our results suggest that the B2B2 genotype of the CETP TaqIB polymorphism is a protective factor against the development of MI. PMID:25474428

Evacetrapib and Cardiovascular Outcomes in High-Risk Vascular Disease.

PubMed

Lincoff, A Michael; Nicholls, Stephen J; Riesmeyer, Jeffrey S; Barter, Philip J; Brewer, H Bryan; Fox, Keith A A; Gibson, C Michael; Granger, Christopher; Menon, Venu; Montalescot, Gilles; Rader, Daniel; Tall, Alan R; McErlean, Ellen; Wolski, Kathy; Ruotolo, Giacomo; Vangerow, Burkhard; Weerakkody, Govinda; Goodman, Shaun G; Conde, Diego; McGuire, Darren K; Nicolau, Jose C; Leiva-Pons, Jose L; Pesant, Yves; Li, Weimin; Kandath, David; Kouz, Simon; Tahirkheli, Naeem; Mason, Denise; Nissen, Steven E

2017-05-18

The cholesteryl ester transfer protein inhibitor evacetrapib substantially raises the high-density lipoprotein (HDL) cholesterol level, reduces the low-density lipoprotein (LDL) cholesterol level, and enhances cellular cholesterol efflux capacity. We sought to determine the effect of evacetrapib on major adverse cardiovascular outcomes in patients with high-risk vascular disease. In a multicenter, randomized, double-blind, placebo-controlled phase 3 trial, we enrolled 12,092 patients who had at least one of the following conditions: an acute coronary syndrome within the previous 30 to 365 days, cerebrovascular atherosclerotic disease, peripheral vascular arterial disease, or diabetes mellitus with coronary artery disease. Patients were randomly assigned to receive either evacetrapib at a dose of 130 mg or matching placebo, administered daily, in addition to standard medical therapy. The primary efficacy end point was the first occurrence of any component of the composite of death from cardiovascular causes, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina. At 3 months, a 31.1% decrease in the mean LDL cholesterol level was observed with evacetrapib versus a 6.0% increase with placebo, and a 133.2% increase in the mean HDL cholesterol level was seen with evacetrapib versus a 1.6% increase with placebo. After 1363 of the planned 1670 primary end-point events had occurred, the data and safety monitoring board recommended that the trial be terminated early because of a lack of efficacy. After a median of 26 months of evacetrapib or placebo, a primary end-point event occurred in 12.9% of the patients in the evacetrapib group and in 12.8% of those in the placebo group (hazard ratio, 1.01; 95% confidence interval, 0.91 to 1.11; P=0.91). Although the cholesteryl ester transfer protein inhibitor evacetrapib had favorable effects on established lipid biomarkers, treatment with evacetrapib did not result in a lower rate of cardiovascular events than placebo among patients with high-risk vascular disease. (Funded by Eli Lilly; ACCELERATE ClinicalTrials.gov number, NCT01687998 .).

Arsenic trioxide suppresses liver X receptor β and enhances cholesteryl ester transfer protein expression without affecting the liver X receptor α in HepG2 cells.

PubMed

Cheng, Tain-Junn; Lin, Shu-Wen; Chen, Chih-Wei; Guo, How-Ran; Wang, Ying-Jang

2016-10-25

Chronic arsenic exposure is associated with cerebrovascular disease and the formation of atherosclerotic lesions. Our previous study demonstrated that arsenic trioxide (ATO) exposure was associated with atherosclerotic lesion formation through alterations in lipid metabolism in the reverse cholesterol transport process. In mouse livers, the expression of the liver X receptor β (LXR-β) and the cholesteryl ester transfer protein (CETP) was suppressed without any changes to the lipid profile. The aim of this study was to elucidate whether ATO contributes to atherosclerotic lesions by suppressing LXR-β and CETP levels in hepatocytes. HepG2 cells, human hepatocytes, were exposed to different ATO concentrations in vitro. Cell viability was determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. The liver X receptor α (LXR-α), LXR-β, sterol regulatory element-binding protein-1c (SREBP-1c) and CETP protein levels were measured by Western blotting, and their mRNA levels were measured by real-time PCR. Cholesterol efflux was analyzed by flow cytometry. The results showed ATO inhibited LXR-β mRNA and protein levels with a subsequent decrease in SREBP-1c protein levels and reduced cholesterol efflux from HepG2 cells into the extracellular space without influencing LXR-α mRNA and protein levels. CETP protein levels of HepG2 cells were significantly elevated under arsenic exposure. Transfection of LXR-β shRNA did not change CETP protein levels, implying that there is no cross-talk between LXR-β and CETP. In conclusion, arsenic not only inhibits LXR-β and SREBP-1c mRNA and protein levels but also independently increases CETP protein levels in HepG2 cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Vitamin E tocotrienol supplementation improves lipid profiles in chronic hemodialysis patients.

PubMed

Daud, Zulfitri A Mat; Tubie, Boniface; Sheyman, Marina; Osia, Robert; Adams, Judy; Tubie, Sharon; Khosla, Pramod

2013-01-01

Chronic hemodialysis patients experience accelerated atherosclerosis contributed to by dyslipidemia, inflammation, and an impaired antioxidant system. Vitamin E tocotrienols possess anti-inflammatory and antioxidant properties. However, the impact of dietary intervention with Vitamin E tocotrienols is unknown in this population. A randomized, double-blind, placebo-controlled, parallel trial was conducted in 81 patients undergoing chronic hemodialysis. Subjects were provided daily with capsules containing either vitamin E tocotrienol-rich fraction (TRF) (180 mg tocotrienols, 40 mg tocopherols) or placebo (0.48 mg tocotrienols, 0.88 mg tocopherols). Endpoints included measurements of inflammatory markers (C-reactive protein and interleukin 6), oxidative status (total antioxidant power and malondialdehyde), lipid profiles (plasma total cholesterol, triacylglycerols, and high-density lipoprotein cholesterol), as well as cholesteryl-ester transfer protein activity and apolipoprotein A1. TRF supplementation did not impact any nutritional, inflammatory, or oxidative status biomarkers over time when compared with the baseline within the group (one-way repeated measures analysis of variance) or when compared with the placebo group at a particular time point (independent t-test). However, the TRF supplemented group showed improvement in lipid profiles after 12 and 16 weeks of intervention when compared with placebo at the respective time points. Normalized plasma triacylglycerols (cf baseline) in the TRF group were reduced by 33 mg/dL (P=0.032) and 36 mg/dL (P=0.072) after 12 and 16 weeks of intervention but no significant improvement was seen in the placebo group. Similarly, normalized plasma high-density lipoprotein cholesterol was higher (P<0.05) in the TRF group as compared with placebo at both week 12 and week 16. The changes in the TRF group at week 12 and week 16 were associated with higher plasma apolipoprotein A1 concentration (P<0.02) and lower cholesteryl-ester transfer protein activity (P<0.001). TRF supplementation improved lipid profiles in this study of maintenance hemodialysis patients. A multi-centered trial is warranted to confirm these observations.

Scavenger receptor B1 (SR-B1) profoundly excludes high density lipoprotein (HDL) apolipoprotein AII as it nibbles HDL-cholesteryl ester.

PubMed

Gillard, Baiba K; Bassett, G Randall; Gotto, Antonio M; Rosales, Corina; Pownall, Henry J

2017-05-26

Reverse cholesterol transport (transfer of macrophage-cholesterol in the subendothelial space of the arterial wall to the liver) is terminated by selective high density lipoprotein (HDL)-cholesteryl ester (CE) uptake, mediated by scavenger receptor class B, type 1 (SR-B1). We tested the validity of two models for this process: "gobbling," i.e. one-step transfer of all HDL-CE to the cell and "nibbling," multiple successive cycles of SR-B1-HDL association during which a few CEs transfer to the cell. Concurrently, we compared cellular uptake of apoAI with that of apoAII, which is more lipophilic than apoAI, using HDL-[ 3 H]CE labeled with [ 125 I]apoAI or [ 125 I]apoAII. The studies were conducted in CHO-K1 and CHO-ldlA7 cells (LDLR -/- ) with (CHO-SR-B1) and without SR-B1 overexpression and in human Huh7 hepatocytes. Relative to CE, both apoAI and apoAII were excluded from uptake by all cells. However, apoAII was more highly excluded from uptake (2-4×) than apoAI. To distinguish gobbling versus nibbling mechanisms, media from incubations of HDL with CHO-SR-B1 cells were analyzed by non-denaturing PAGE, size-exclusion chromatography, and the distribution of apoAI, apoAII, cholesterol, and phospholipid among HDL species as a function of incubation time. HDL size gradually decreased, i.e. nibbling, with the concurrent release of lipid-free apoAI; apoAII was retained in an HDL remnant. Our data support an SR-B1 nibbling mechanism that is similar to that of streptococcal serum opacity factor, which also selectively removes CE and releases apoAI, leaving an apoAII-rich remnant. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Impact of unhealthy lifestyle behaviors and obesity on cholesteryl ester transfer protein among adolescent males.

PubMed

Hirschler, Valeria; Meroño, Tomas; Maccallini, Gustavo; Gomez Rosso, Leonardo; Aranda, Claudio; Brites, Fernando

2011-01-01

Cholesteryl ester transfer protein (CETP) has been proposed to be associated with high risk of cardiovascular disease. Increased CETP activity was previously reported in obese adults, although its association with lifestyle behaviors has not been assessed in healthy adolescents. We undertook this study to determine the association between CETP activity and overweight/obesity, insulin resistance markers, components of the metabolic syndrome and lifestyle behaviors in healthy adolescent males. Data were collected from 164 adolescents from an amateur rugby club. Body mass index (BMI), blood pressure (BP), Tanner stages, lipids, glucose, insulin and CETP activity were measured. Questionnaires for daily intake of breakfast, sweet drinks, milk, and hours of TV watching were completed. About 26% of the adolescents were obese and 23% overweight. The prevalence of metabolic syndrome was 6.7%. CETP activity was higher in obese than in normal and overweight adolescents (174 ± 35, 141 ± 30, and 149 ± 38%/ml/min, respectively; p <0.001). Univariate correlations showed an inverse association between CETP and HDL-C (r = -0.43; p = 0.018) and positive ones with BMI (r = 0.38; p = 0.007), systolic BP (r = 0.20; p <0.01) triglycerides (r = 0.40; p = 0.001), LDL-C (r = 0.46; p <0.001), TV watching >2 h/day (r = 0.17; p 0.02), and milk intake >3 glasses/day (r = 0.16; p = 0.03). Multivariate analysis showed that triglycerides, LDL-C, HDL-C, TV watching >2 h/day, milk intake >3 glasses/day and BMI were significant independent predictors for CETP (R(2) = 0.41). Unhealthy lifestyle habits such as TV watching >2 h daily and milk intake higher than three glasses per day and the increase in BMI were shown to be closely associated with high CETP activity in apparently healthy adolescent males. Future longitudinal studies should be performed to confirm these findings. Copyright © 2011 IMSS. Published by Elsevier Inc. All rights reserved.

The Relationship Between Genetic Variations of the Cholesteryl Ester Transfer Protein Gene and Coronary Artery Disease in Turkish Subjects

PubMed Central

Gundogdu, Fuat; Gurlertop, Yekta; Pirim, Ibrahim; Sevimli, Serdar; Dogan, Hasan; Arslan, Sakir; Aksoy, Hulya; Karakelloglu, Sule; Senocak, Huseyin

2009-01-01

Objective Although the relationship between cholesteryl ester transfer protein (CETP) and cholesterol metabolism has been characterized in recent years, the effect of CETP genetic variants associated with coronary artery disease (CAD) is still unclear. Therefore, we investigated the association between CETP gene polymorphism and levels of lipid in patients with CAD. Materials and Methods We conducted a case-control study that included 194 unrelated subjects who underwent coronary angiography for suspected ischemic heart disease. This group was divided into 96 patients with angiographically documented CAD and 98 subjects (individuals matched for age and gender) without angiographically documented CAD (CAD-free subjects), all of whom were studied to examine the genotypic distribution of the CETP gene polymorphism in CAD. Genotyping was performed via polymerase chain reaction. Results Of the 96 patients with CAD, 38 (40%) were B1B1, 42 (44%) B1B2 and 16 (16%) B2B2, compared with the control subjects, of which 35 (36%) were B1B1, 44 (45%) B1B2 and 19 (19%) B2B2. There were no significant differences between patients with CAD and control subjects in the distribution of the CETP gene polymorphism. Patients with the B1B1 genotype had lower high-density lipoprotein-cholesterol (HDL-C) and higher triglyceride (TG) levels than patients with the B2B2 genotype (p<0.05). In addition, among control subjects HDL-C levels were significantly higher in subjects with the B2B2 genotype than in subjects with the B1B1 genotype (p<0.01). Conclusion Our results suggest that genetic variations of the CTEP gene may be responsible for low HDL-C levels but may not be considered as a risk factor for CAD in the Turkish population. PMID:25610061

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.

Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

PubMed Central

Guo, Shu-xia; Yao, Ming-hong; Ding, Yu-song; Zhang, Jing-yu; Yan, Yi-zhong; Liu, Jia-ming; Zhang, Mei; Rui, Dong-sheng; Niu, Qiang; He, Jia; Guo, Heng; Ma, Ru-lin

2016-01-01

Background: Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism (rs708272), the risk of developing composite ischemic cardiovascular disease (CVD) and the concentration of high-density lipoprotein cholesterol (HDL-C), but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors. Methods: We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0. Results: Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09–1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. Results suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36–0.65, p < 0.001. Conclusions: The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians. PMID:27608031

Success, Failure, and Transparency in Biomarker-Based Drug Development: A Case Study of Cholesteryl Ester Transfer Protein Inhibitors.

PubMed

Hey, Spencer Phillips; Franklin, Jessica M; Avorn, Jerry; Kesselheim, Aaron S

2017-06-01

Although biomarkers are used as surrogate measures for drug targeting and approval and are generally based on plausible biological hypotheses, some are found to not correlate well with clinical outcomes. Over-reliance on inadequately validated biomarkers in drug development can lead to harm to trial subjects and patients and to research waste. To shed greater light on the process and ethics of biomarker-based drug development, we conducted a systematic portfolio analysis of cholesterol ester transfer protein inhibitors, a drug class designed to improve lipid profiles and prevent cardiovascular events. Despite years of development, no cholesterol ester transfer protein inhibitor has yet been approved for clinical use. We searched PubMed and Clinicaltrials.gov for clinical studies of 5 known cholesterol ester transfer protein inhibitors: anacetrapib, dalcetrapib, evacetrapib, TA-8995, and torcetrapib. Published reports and registration records were extracted for patient demographic characteristics and study authors' recommendations of clinical usage or further testing. We used Accumulating Evidence and Research Organization graphing to depict the portfolio of research activities and a Poisson model to examine trends. We identified 100 studies for analysis that involved 96 944 human subjects. The data from only 41 201 (42%) of the human subjects had been presented in a published report. For the 3 discontinued cholesterol ester transfer protein inhibitors, we found a pattern of consistently positive results on lipid-modification end points followed by negative results using clinical end points. Inefficiencies and harms can arise if a biomarker hypothesis continues to drive trials despite successive failures. Regulators, research funding bodies, and public policy makers may need to play a greater role in evaluating and coordinating biomarker-driven research programs. © 2017 American Heart Association, Inc.

Pharmacogenomics of high-density lipoprotein-cholesterol-raising therapies

PubMed Central

Aslibekyan, Stella; Straka, Robert J.; Irvin, Marguerite R.; Claas, Steven A.; Arnett, Donna K.

2017-01-01

High levels of HDL cholesterol (HDL-C) have traditionally been linked to lower incidence of cardiovascular disease, prompting the search for effective and safe HDL-C raising pharmaceutical agents. Although drugs such as niacin and fibrates represent established therapeutic approaches, HDL-C response to such therapies is variable and heritable, suggesting a role for pharmacogenomic determinants. Multiple genetic polymorphisms, located primarily in genes encoding lipoproteins, cholesteryl ester transfer protein, transporters and CYP450 genes have been shown to associate with HDL-C drug response in vitro and in epidemiologic studies. However, few of the pharmacogenomic findings have been independently validated, precluding the development of clinical tools that can be used to predict HDL-C response and leaving the goal of personalized medicine to future efforts. PMID:23469915

Dietary n-3 LCPUFA from fish oil but not α-linolenic acid-derived LCPUFA confers atheroprotection in mice[S

PubMed Central

Degirolamo, Chiara; Kelley, Kathryn L.; Wilson, Martha D.; Rudel, Lawrence L.

2010-01-01

The atheroprotective potential of n-3 α-linolenic acid (ALA) has not yet been fully determined, even in murine models of atherosclerosis. We tested whether ALA-derived, n-3 long chain polyunsaturated fatty acids (LCPUFA) could offer atheroprotection in a dose-dependent manner. Apolipoprotein B (ApoB)100/100LDLr−/− mice were fed with diets containing two levels of ALA from flaxseed oil for 16 weeks. Fish oil- and cis-monounsaturated-fat-enriched diets were used as positive and negative controls, respectively. The mice fed cis-monounsaturated fat and ALA-enriched diets exhibited equivalent plasma total cholesterol (TPC) and LDL-cholesterol (LDL-c) levels; only mice fed the fish-oil diet had lower TPC and LDL-c concentrations. Plasma LDL-CE fatty acid composition analysis showed that ALA-enriched diets lowered the percentage of atherogenic cholesteryl oleate compared with cis-monounsaturated-fat diet (44% versus 55.6%) but not as efficiently as the fish-oil diet (32.4%). Although both ALA and fish-oil diets equally enriched hepatic phospholipids with eicosapentaenoic acid (EPA) and ALA-enriched diets lowered hepatic cholesteryl ester (CE) levels compared with cis-monounsaturated-fat diet, only fish oil strongly protected from atherosclerosis. These outcomes indicate that dietary n-3 LCPUFA from fish oil and n-3 LCPUFA (mostly EPA) synthesized endogenously from ALA were not equally atheroprotective in these mice. PMID:20154006

Color-tunable, aggregation-induced emission of a butterfly-shaped molecule comprising a pyran skeleton and two cholesteryl wings.

PubMed

Tong, Hui; Hong, Yuning; Dong, Yongqiang; Ren, Yan; Häussler, Matthias; Lam, Jacky W Y; Wong, Kam Sing; Tang, Ben Zhong

2007-03-01

A chiral pyran derivative containing two cholesteryl groups (1) is synthesized, and its optical properties are investigated. Whereas the isolated molecule of 1 is virtually nonluminescent in dilute solutions, it becomes highly emissive with a 2 orders of magnitude increase in fluorescence quantum yield upon aggregation in poor solvents or in solid state, showing a novel phenomenon of aggregation-induced emission (AIE). The color and efficiency of the AIE of 1 can be tuned by varying the morphology of its aggregates: photoluminescence of its aggregates formed in a tetrahydrofuran/water mixture progressively red-shifts (green --> yellow --> red) with increasing water content of the mixture, with the crystalline aggregates emitting bluer lights in higher efficiencies than their amorphous counterparts.

Prolonged Caloric Restriction in Obese Patients With Type 2 Diabetes Mellitus Decreases Plasma CETP and Increases Apolipoprotein AI Levels Without Improving the Cholesterol Efflux Properties of HDL

PubMed Central

Wang, Yanan; Snel, Marieke; Jonker, Jacqueline T.; Hammer, Sebastiaan; Lamb, Hildo J.; de Roos, Albert; Meinders, A. Edo; Pijl, Hanno; Romijn, Johannes A.; Smit, Johannes W.A.; Jazet, Ingrid M.; Rensen, Patrick C.N.

2011-01-01

OBJECTIVE Using a mouse model for human-like lipoprotein metabolism, we observed previously that reduction of the hepatic triglyceride (TG) content resulted in a decrease in plasma cholesteryl ester transfer protein (CETP) and an increase in HDL levels. The aim of the current study was to investigate the effects of prolonged caloric restriction in obese patients with type 2 diabetes mellitus, resulting in a major reduction in hepatic TG content, on plasma CETP and HDL levels. RESEARCH DESIGN AND METHODS We studied 27 obese (BMI: 37.2 ± 0.9 kg/m2) insulin-dependent patients with type 2 diabetes mellitus (14 men and 13 women, aged 55 ± 2 years) who received a 16-week very low calorie diet (VLCD). At baseline and after a 16-week VLCD, plasma lipids, lipoproteins, and CETP were measured. Furthermore, functionality of HDL with respect to inducing cholesterol efflux from human monocyte cells (THP-1) was determined. RESULTS A 16-week VLCD markedly decreased plasma CETP concentration (−18%; P < 0.01) and increased plasma apolipoprotein (apo)AI levels (+16%; P < 0.05), without significantly affecting plasma HDL-cholesterol and HDL-phospholipids. Although a VLCD results in HDL that is less lipidated, the functionality of HDL with respect to inducing cholesterol efflux in vitro was unchanged. CONCLUSIONS The marked decrease in hepatic TG content induced by a 16-week VLCD is accompanied by a decrease in plasma CETP concentration and an increase in apoAI levels, without improving the cholesterol efflux properties of HDL in vitro. PMID:21994427

Variability of some diterpene esters in coffee beverages as influenced by brewing procedures.

PubMed

Moeenfard, Marzieh; Erny, Guillaume L; Alves, Arminda

2016-11-01

Several coffee brews, including classical and commercial beverages, were analyzed for their diterpene esters content (cafestol and kahweol linoleate, oleate, palmitate and stearate) by high performance liquid chromatography with diode array detector (HPLC-DAD) combined with spectral deconvolution. Due to the coelution of cafestol and kahweol esters at 225 nm, HPLC-DAD did not give accurate quantification of cafestol esters. Accordingly, spectral deconvolution was used to deconvolve the co-migrating profiles. Total cafestol and kahweol esters content of classical coffee brews ranged from 5-232 to 2-1016 mg/L, respectively. Commercial blends contained 1-54 mg/L of total cafestol esters and 2-403 mg/L of total kahweol esters. Boiled coffee had the highest diterpene esters content, while filtered and instant brews showed the lowest concentrations. However, individual diterpene esters content was not affected by brewing procedure as in terms of kahweol esters, kahweol palmitate was the main compound in all samples, followed by kahweol linoleate, oleate and stearate. Higher amounts of cafestol palmitate and stearate were also observed compared to cafestol linoleate and cafestol oleate. The ratio of diterpene esters esterified with unsaturated fatty acids to total diterpene esters was considered as measure of their unsaturation in analyzed samples which varied from 47 to 52%. Providing new information regarding the diterpene esters content and their distribution in coffee brews will allow a better use of coffee as a functional beverage.

Effect of medicinal plants on the crystallization of cholesterol

NASA Astrophysics Data System (ADS)

Saraswathi, N. T.; Gnanam, F. D.

1997-08-01

One of the least desirable calcifications in the human body is the mineral deposition in atherosclerosis plaques. These plaques principally consist of lipids such as cholesterol, cholesteryl esters, phospholipids and triglycerides. Chemical analysis of advanced plaques have shown the presence of considerable amounts of free cholesterol identified as cholesterol monohydrate crystals. Cholesterol has been crystallized in vitro. The extracts of some of the Indian medicinal plants detailed below were used as additives to study their effect on the crystallization behaviour of cholesterol. It has been found that many of the herbs have inhibitory effect on the crystallization such as nucleation, crystal size and habit modification. The inhibitory effect of the plants are graded as Commiphora mughul > Aegle marmeleos > Cynoden dactylon > Musa paradisiaca > Polygala javana > Alphinia officinarum > Solanum trilobatum > Enicostemma lyssopifolium.

Lipidomics in triacylglycerol and cholesteryl ester oxidation.

PubMed

Kuksis, Arnis

2007-05-01

Although direct mass spectrometry is capable of identification the major molecular species of lipids in crude total lipid extracts, prior chromatographic isolation is necessary for detection and identification of the minor components. This is especially important for the analysis of the oxolipids, which usually occur in trace amounts in the total lipid extract, and require prior isolation for detailed analysis. Both thin-layer chromatography and adsorption cartridges provide effective means for isolation and enrichment of lipid classes, while gas-liquid chromatography and high performance liquid chromatography with on-line mass spectrometry permit further separation and identification of molecular species. Prior chromatographic resolution is absolutely necessary for the identification of isobaric and chiral molecules, which mass spectrometry/mass spectrometry (MS/MS) cannot distinguish. Both gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry applications may require the preparation of derivatives in order to improve the chromatographic and mass spectrometric properties of the oxolipids which is a small inconvenience for securing analytical reliability. The following chapter reviews the advantages and necessity of combined chromatographic-mass spectrometric approaches to successful identification and quantification of molecular species of oxoacylglycerols and oxocholesteryl esters in in-vitro model studies of lipid peroxidation and in the analyses of oxolipids recovered from tissues.

An albumin-mediated cholesterol design-based strategy for tuning siRNA pharmacokinetics and gene silencing.

PubMed

Bienk, Konrad; Hvam, Michael Lykke; Pakula, Malgorzata Maria; Dagnæs-Hansen, Frederik; Wengel, Jesper; Malle, Birgitte Mølholm; Kragh-Hansen, Ulrich; Cameron, Jason; Bukrinski, Jens Thostrup; Howard, Kenneth A

2016-06-28

Major challenges for the clinical translation of small interfering RNA (siRNA) include overcoming the poor plasma half-life, site-specific delivery and modulation of gene silencing. In this work, we exploit the intrinsic transport properties of human serum albumin to tune the blood circulatory half-life, hepatic accumulation and gene silencing; based on the number of siRNA cholesteryl modifications. We demonstrate by a gel shift assay a strong and specific affinity of recombinant human serum albumin (rHSA) towards cholesteryl-modified siRNA (Kd>1×10(-7)M) dependent on number of modifications. The rHSA/siRNA complex exhibited reduced nuclease degradation and reduced induction of TNF-α production by human peripheral blood mononuclear cells. The increased solubility of heavily cholesteryl modified siRNA in the presence of rHSA facilitated duplex annealing and consequent interaction that allowed in vivo studies using multiple cholesteryl modifications. A structural-activity-based screen of in vitro EGFP-silencing was used to select optimal siRNA designs containing cholesteryl modifications within the sense strand that were used for in vivo studies. We demonstrate plasma half-life extension in NMRI mice from t1/2 12min (naked) to t1/2 45min (single cholesteryl) and t1/2 71min (double cholesteryl) using fluorescent live bioimaging. The biodistribution showed increased accumulation in the liver for the double cholesteryl modified siRNA that correlated with an increase in hepatic Factor VII gene silencing of 28% (rHSA/siRNA) compared to 4% (naked siRNA) 6days post-injection. This work presents a novel albumin-mediated cholesteryl design-based strategy for tuning pharmacokinetics and systemic gene silencing. Copyright © 2016 Elsevier B.V. All rights reserved.

Self-assembled nanogels of cholesteryl-modified polysaccharides: effect of the polysaccharide structure on their association characteristics in the dilute and semidilute regimes.

PubMed

Akiyama, Eri; Morimoto, Nobuyuki; Kujawa, Piotr; Ozawa, Yayoi; Winnik, Françoise M; Akiyoshi, Kazunari

2007-08-01

The assembly of cholesteryl derivatives of the highly branched polysaccharide mannan Mw = (5.2 x 104 g/mol) in dilute aqueous solution was investigated by 1H nuclear magnetic resonance (NMR) spectroscopy, size-exclusion chromatography coupled with multiangle laser scattering (SEC-MALLS), dynamic light scattering (DLS), atomic force microscopy (AFM), fluorescence quenching, and fluorescence depolarization measurements. In the dilute regime, cholesteryl-bearing mannans (CHM) containing approximately 1 cholesteryl group per 100 mannopyranose units formed nanogels with a hydrodynamic radius (RH) of approximately 20 nm containing approximately 8 macromolecules held together via hydrophobic nanodomains consisting of approximately 9 cholesteryl groups. Their density Phih ( approximately 0.02) was significantly lower than the density ( approximately 0.16) of nanogels formed by a cholesteryl derivative of the linear polysaccharide pullulan (CHP) of identical molar mass and level of cholesteryl substitution. In the semidilute regime, CHM nanogels formed a macrogel network for concentrations higher than 12.5% w/w, whereas CHP nanogels underwent macrogelation only above a threshold concentration of 8.0% w/w, as revealed by oscillatory and steady-shear viscosity measurements. The differences in the solution properties of CHM and CHP reflect differences in their assembly on the molecular level, in particular, the size and number of hydrophobic nanodomains and the hydration level. They are attributed to differences in the mobility of the cholesteryl groups which, itself, can be traced to the fact that in CHM the cholesteryl groups are predominantly linked to short oligomannopyranose branches, whereas in CHP they are linked to the polymer main chain. Our study provides a novel means to nanoengineer polysaccharide nanogels which may find unique biotechnological applications.

The regulation of 3-hydroxy-3-methylglutaryl-CoA reductase activity, cholesterol esterification and the expression of low-density lipoprotein receptors in cultured monocyte-derived macrophages.

PubMed Central

Knight, B L; Patel, D D; Soutar, A K

1983-01-01

Human blood monocytes cultured in medium containing 20% whole serum showed the greatest activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and [14C]acetate incorporation into non-saponifiable lipids around the 7th day after seeding, the period of greatest growth. Although there was enough low-density lipoprotein (LDL) in the medium to saturate the LDL receptors that were expressed by normal cells at that time, HMG-CoA reductase activity and acetate incorporation were as high in normal cells as in cells from familial-hypercholesterolaemic (FH) patients. Both the addition of extra LDL, which interacted with the cells by non-saturable processes, and receptor-mediated uptake of acetylated LDL significantly reduced reductase activity and increased incorporation of [14C]oleate into cholesteryl esters in normal cells and cells from FH patients ('FH cells'), and reduced the expression of LDL receptors in normal cells. Pre-incubation for 20h in lipoprotein-deficient medium apparently increased the number of LDL receptors expressed by normal cells but reduced the activity of HMG-CoA reductase in both normal and FH cells. During subsequent incubations the same rate of degradation of acetylated LDL and of non-saturable degradation of LDL by FH cells was associated with the same reduction in HMG-CoA reductase activity, although LDL produced a much smaller stimulation of oleate incorporation into cholesteryl esters. In normal cells pre-incubated without lipoproteins, receptor-mediated uptake of LDL could abolish reductase activity and the expression of LDL receptors. The results suggested that in these cells, receptor-mediated uptake of LDL might have a greater effect on reductase activity and LDL receptors than the equivalent uptake of acetylated LDL. It is proposed that endogenous synthesis is an important source of cholesterol for growth of normal cells, and that the site at which cholesterol is deposited in the cells may determine the nature and extent of the metabolic events that follow. PMID:6305342

Genetic variants associated with myocardial infarction risk factors in over 8000 individuals from five ethnic groups: The INTERHEART Genetics Study.

PubMed

Anand, Sonia S; Xie, Changchun; Paré, Guillaume; Montpetit, Alexandre; Rangarajan, Sumathy; McQueen, Matthew J; Cordell, Heather J; Keavney, Bernard; Yusuf, Salim; Hudson, Thomas J; Engert, James C

2009-02-01

Myocardial infarction (MI) is a leading cause of death globally, but specific genetic variants that influence MI and MI risk factors have not been assessed on a global basis. We included 8795 individuals of European, South Asian, Arab, Iranian, and Nepalese origin from the INTERHEART case-control study that genotyped 1536 single-nucleotide polymorphisms (SNPs) from 103 genes. One hundred and two SNPs were nominally associated with MI, but the statistical significance did not remain after adjustment for multiple testing. A subset of 940 SNPs from 69 genes were tested against MI risk factors. One hundred and sixty-three SNPs were nominally associated with a MI risk factor and 13 remained significant after adjusting for multiple testing. Of these 13, 11 were associated with apolipoprotein (Apo) B/A1 levels: 8 SNPs from 3 genes were associated with Apo B, and 3 cholesteryl ester transfer protein SNPs were associated with Apo A1. Seven of 8 of the SNPs associated with Apo B levels were nominally associated with MI (P<0.05), whereas none of the 3 cholesteryl ester transfer protein SNPs were associated with MI (P> or =0.17). Of the 3 SNPs most significantly associated with MI, rs7412, which defines the Apo E2 isoform, was associated with both a lower Apo B/A1 ratio (P=1.0x10(-7)) and lower MI risk (P=0.0004). Two low-density lipoprotein receptor variants, 1 intronic (rs6511720) and 1 in the 3' untranslated region (rs1433099) were both associated with a lower Apo B/A1 ratio (P<1.0x10(-5)) and a lower risk of MI (P=0.004 and P=0.003, respectively). Thirteen common SNPs were associated with MI risk factors. Importantly, SNPs associated with Apo B levels were associated with MI, whereas SNPs associated with Apo A1 levels were not. The Apo E isoform, and 2 common low-density lipoprotein receptor variants (rs1433099 and rs6511720) influence MI risk in this multiethnic sample.

Intake of up to 3 Eggs per Day Is Associated with Changes in HDL Function and Increased Plasma Antioxidants in Healthy, Young Adults.

PubMed

DiMarco, Diana M; Norris, Gregory H; Millar, Courtney L; Blesso, Christopher N; Fernandez, Maria Luz

2017-03-01

Background: HDL function may be more important than HDL concentration in determining risk for cardiovascular disease. In addition, HDL is a carrier of carotenoids and antioxidant enzymes, which protect HDL and LDL particles against oxidation. Objective: The goal of this study was to determine the impact of consuming 0-3 eggs/d on LDL and HDL particle size, HDL function, and plasma antioxidants in a young, healthy population. Methods: Thirty-eight healthy men and women [age 18-30 y, body mass index (in kg/m 2 ) 18.5-29.9] participated in this 14-wk crossover intervention. Subjects underwent a 2-wk washout (0 eggs/d) followed by sequentially increasing intake of 1, 2, and 3 eggs/d for 4 wk each. After each period, fasting blood was collected for analysis of lipoprotein subfractions, plasma apolipoprotein (apo) concentration, lutein and zeaxanthin concentration, and activities of lecithin-cholesterol acyltransferase, cholesteryl ester transfer protein, and paraoxonase-1. Results: Compared with intake of 0 eggs/d, consuming 1-3 eggs/d resulted in increased large-LDL (21-37%) and large-HDL (6-13%) particle concentrations, plasma apoAI (9-15%), and lecithin-cholesterol acyltransferase activity (5-15%) ( P < 0.05 for all biomarkers). Intake of 2-3 eggs/d also promoted an 11% increase in apoAII ( P < 0.05) and a 20-31% increase in plasma lutein and zeaxanthin ( P < 0.05), whereas intake of 3 eggs/d resulted in a 9-16% increase in serum paraoxonase-1 activity compared with intake of 1-2 eggs/d ( P < 0.05). Egg intake did not affect cholesteryl ester transfer protein activity. Conclusions: Intake of 1 egg/d was sufficient to increase HDL function and large-LDL particle concentration; however, intake of 2-3 eggs/d supported greater improvements in HDL function as well as increased plasma carotenoids. Overall, intake of ≤3 eggs/d favored a less atherogenic LDL particle profile, improved HDL function, and increased plasma antioxidants in young, healthy adults. This trial was registered at clinicaltrials.gov as NCT02531958. © 2017 American Society for Nutrition.

Altered relationship of plasma triglycerides to HDL cholesterol in patients with HIV/HAART-associated dyslipidemia: further evidence for a unique form of metabolic syndrome in HIV patients.

PubMed

Vu, Catherine N; Ruiz-Esponda, Raul; Yang, Eric; Chang, Evelyn; Gillard, Baiba; Pownall, Henry J; Hoogeveen, Ron C; Coraza, Ivonne; Balasubramanyam, Ashok

2013-07-01

Plasma triglycerides (TG) and HDL-C are inversely related in Metabolic Syndrome (MetS), due to exchange of VLDL-TG for HDL-cholesteryl esters catalyzed by cholesteryl ester transfer protein (CETP). We investigated the relationship of TG to HDL-C in highly-active antiretroviral drug (HAART)-treated HIV patients. Fasting plasma TG and HDL-C levels were compared in 179 hypertriglyceridemic HIV/HAART patients and 71 HIV-negative persons (31 normotriglyceridemic (NL) and 40 hypertriglyceridemic due to type IV hyperlipidemia (HTG)). CETP mass and activity were compared in 19 NL and 87 HIV/HAART subjects. Among the three groups, a plot of HDL-C vs. TG gave similar slopes but significantly different y-intercepts (9.24±0.45, 8.16±0.54, 6.70±0.65, sqrt(HDL-C) for NL, HIV and HTG respectively; P<0.001); this difference persisted after adjusting HDL-C for TG, age, BMI, gender, glucose, CD4 count, viral load and HAART strata (7.18±0.20, 6.20±0.05 and 4.55±0.15 sqrt(HDL-C) for NL, HIV and HTG, respectively, P<0.001). CETP activity was not different between NL and HIV, but CETP mass was significantly higher in HIV (1.47±0.53 compared to 0.93±0.27μg/mL, P<0.0001), hence CETP specific activity was lower in HIV (22.67±13.46 compared to 28.46±8.24nmol/μg/h, P=0.001). Dyslipidemic HIV/HAART patients have a distinctive HDL-C plasma concentration adjusted for TG. The weak inverse relationship between HDL-C and TG is not explained by altered total CETP activity; it could result from a non-CETP-dependent mechanism or a decrease in CETP function due to inhibitors of CETP activity in HIV patients' plasma. Copyright © 2013 Elsevier Inc. All rights reserved.

Clinical effect and safety profile of recombinant human lysosomal acid lipase in patients with cholesteryl ester storage disease.

PubMed

Balwani, Manisha; Breen, Catherine; Enns, Gregory M; Deegan, Patrick B; Honzík, Tomas; Jones, Simon; Kane, John P; Malinova, Vera; Sharma, Reena; Stock, Eveline O; Valayannopoulos, Vassili; Wraith, J Edmond; Burg, Jennifer; Eckert, Stephen; Schneider, Eugene; Quinn, Anthony G

2013-09-01

Cholesteryl ester storage disease (CESD), an inherited deficiency of lysosomal acid lipase (LAL), is an underappreciated cause of progressive liver disease with no approved therapy. Presenting features include dyslipidemia, elevated transaminases, and hepatomegaly. To assess the clinical effects and safety of the recombinant human LAL, sebelipase alfa, nine patients received four once-weekly infusions (0.35, 1, or 3 mg·kg(-1) ) in LAL-CL01, which is the first human study of this investigational agent. Patients completing LAL-CL01 were eligible to enroll in the extension study (LAL-CL04) in which they again received four once-weekly infusions of sebelipase alfa (0.35, 1, or 3 mg·kg(-1) ) before transitioning to long-term every-other-week infusions (1 or 3 mg·kg(-1) ). Sebelipase alfa was well tolerated, with mostly mild adverse events unrelated to sebelipase alfa. No antidrug antibodies were detected. Transaminases decreased in patients in LAL-CL01 and increased between studies. In seven patients receiving ongoing sebelipase alfa treatment in LAL-CL04, the mean ± standard deviation (SD) decreases for alanine transaminase and aspartate aminotransferase at week 12 compared to the baseline values in LAL-CL01 were 46 ± 21 U/L (-52%) and 21 ± 14 U/L (-36%), respectively (P ≤ 0.05). Through week 12 of LAL-CL04, these seven patients also showed mean decreases from baseline in total cholesterol of 44 ± 41 mg/dL (-22%; P = 0.047), low density lipoprotein-cholesterol of 29 ± 31 mg/dL (-27%; P = 0.078), and triglycerides of 50 ± 38 mg/dL (-28%, P = 0.016) and increases in high density lipoprotein-cholesterol of 5 mg/dL (15%; P = 0.016). These data establish that sebelipase alfa, an investigational enzyme replacement, in patients with CESD is well tolerated, rapidly decreases serum transaminases, and that these improvements are sustained with long-term dosing and are accompanied by improvements in serum lipid profile. Copyright © 2013 American Association for the Study of Liver Diseases.

Secretion of prebeta HDL increases with the suppression of cholesteryl ester transfer protein in Hep G2 cells.

PubMed

Sawada, S; Sugano, M; Makino, N; Okamoto, H; Tsuchida, K

1999-10-01

Prebeta HDL are small, protein rich lipoproteins that are predominantly composed of apo A-I, without apo A-II. Prebeta HDL are secreted from the liver as nascent HDL and/or are produced in the incubated plasma by cholesteryl ester transfer protein (CETP). However, the role of CETP in the secretion of HDL from the liver has yet to be determined. In the present study, we examined the effect of the suppression of hepatic CETP by antisense oligodeoxynucleotides (ODNs) against CETP targeted to the liver on the secretion of apo A-I using a Hep G2 cell culture. The ODNs against CETP were coupled to asialoglycoprotein (ASOR) carrier molecules, which serve as an important method for the regulation of liver gene expression. Hep G2 cells were cultured in DMEM supplemented with 10 FBS. After 2 days, the medium was changed to DMEM with EGF and the cells were divided into three groups. The control group received saline, while the sense group was mixed with the sense ODNs complex and the antisense group was mixed with the antisense ODNs complex, respectively, for 2 days. Both the hepatic CETP mRNA and the CETP mass in the medium in the antisense group decreased significantly more than in the sense and the control groups (CETP mass: 1.697 + /- 0.410 ng/mg cell protein vs. 2.367 + /- 0.22 and 2.360 + /- 0.139, n = 3 in each determination). In contrast, both the hepatic apo A-I mRNA and the apo A-I mass in the medium in the antisense group were significantly higher than those in the sense and the control groups (apo A-I mass; 1.877 + /- 0.215 micro/mg cell protein vs. 1.213 + /- 0.282 and 1.097 + /- 0.144, n = 3 in each determination). The increase in apo A-I was mainly due to the increase in prebeta apo A-I. These findings may partly explain why HDL and apo A-I increase in patients with CETP deficiency, while also indicating the possibility that the original level of prebeta HDL is sufficient in such patients.

Off-Target Vascular Effects of Cholesteryl Ester Transfer Protein Inhibitors Involve Redox-Sensitive and Signal Transducer and Activator of Transcription 3-Dependent Pathways.

PubMed

Rios, Francisco J; Lopes, Rheure A; Neves, Karla B; Camargo, Livia L; Montezano, Augusto C; Touyz, Rhian M

2016-05-01

Elevated blood pressure was an unexpected outcome in some cholesteryl ester transfer protein (CETP) inhibitor trials, possibly due to vascular effects of these drugs. We investigated whether CETP inhibitors (torcetrapib, dalcetrapib, anacetrapib) influence vascular function and explored the putative underlying molecular mechanisms. Resistance arteries and vascular smooth muscle cells (VSMC) from rats, which lack the CETP gene, were studied. CETP inhibitors increased phenylephrine-stimulated vascular contraction (logEC50 (:) 6.6 ± 0.1; 6.4 ± 0.06, and 6.2 ± 0.09 for torcetrapib, dalcetrapib, and anacetrapib, respectively, versus control 5.9 ± 0.05). Only torcetrapib reduced endothelium-dependent vasorelaxation. The CETP inhibitor effects were ameliorated by N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, and by S3I-201 [2-hydroxy-4-[[2-(4-methylphenyl)sulfonyloxyacetyl]amino]benzoic acid], a signal transducer and activator of transcription 3 (STAT3) inhibitor. CETP inhibitors increased the phosphorylation (2- to 3-fold) of vascular myosin light chain (MLC) and myosin phosphatase target subunit 1 (MYPT1) (procontractile proteins) and stimulated ROS production. CETP inhibitors increased the phosphorylation of STAT3 (by 3- to 4-fold), a transcription factor important in cell activation. Activation of MLC was reduced by NAC, GKT137831 [2-(2-chlorophenyl)-4-[3-(dimethylamino)phenyl]-5-methyl-1H-pyrazolo[4,3-c]pyridine-3,6-dione] (Nox1/4 inhibitor), and S3I-201. The phosphorylation of STAT3 was unaffected by NAC and GKT137831. CETP inhibitors did not influence activation of mitogen-activated proteins kinases (MAPK) or c-Src. Our data demonstrate that CETP inhibitors influence vascular function and contraction through redox-sensitive, STAT3-dependent, and MAPK-independent processes. These phenomena do not involve CETP because the CETP gene is absent in rodents. Findings from our study indicate that CETP inhibitors have vasoactive properties, which may contribute to the adverse cardiovascular effects of these drugs such as hypertension. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Plasma lipids, lipoprotein metabolism and HDL lipid transfers are equally altered in metabolic syndrome and in type 2 diabetes.

PubMed

Silva, Vanessa M; Vinagre, Carmen G C; Dallan, Luis A O; Chacra, Ana P M; Maranhão, Raul C

2014-07-01

Metabolic syndrome (MetS) refers to states of insulin resistance that predispose to development of cardiovascular disease and type 2 diabetes (T2DM). The aim was to investigate whether plasma lipids and lipid metabolism differ in MetS patients compared to those with T2DM with poor glycemic control (glycated hemoglobin > 7.0). Eighteen patients with T2DM, 18 with MetS and 14 controls, paired for age (40-70 years) and body mass index (BMI), were studied. Plasma lipids and the kinetics of a triacylglycerol-rich emulsion labeled with [(3)H]-triolein ([(3)H]-TAG) and [(14)C]-cholesteryl esters ([(14)C]-CE) injected intravenously followed by one-hour blood sampling were determined. Lipid transfers from an artificial nanoemulsion donor to high-density lipoprotien (HDL) were assayed in vitro. Low-density lipoprotein (LDL) and HDL cholesterol (mg/dl) were not different in T2DM (128 ± 7; 42 ± 7) and MetS (142 ± 6; 39 ± 3), but triacylglycerols were even higher in MetS (215 ± 13) than in T2DM (161 ±11, p < 0.05). Fractional clearance rate (FCR, in min(1)) of [(3)H]-TAG and [(14)C]-CE were equal in T2DM (0.008 ± 0.018; 0.005 ± 0.024) and MetS (0.010 ± 0.016; 0.006 ± 0.013), and both were reduced compared to controls. The transfer of non-esterified cholesterol, phospholipids and triacylglycerols to HDL was higher in MetS and T2DM than in controls (p < 0.01). Cholesteryl ester transfer and HDL size were equal in all groups. Results imply that MetS is equal to poorly controlled T2DM concerning the disturbances of plasma lipid metabolism examined here, and suggest that there are different thresholds for the insulin action on glucose and lipids. These findings highlight the magnitude of the lipid disturbances in MetS, and may have implications in the prevention of cardiovascular diseases.

Interrelationships between postprandial lipoprotein B:CIII particle changes and high-density lipoprotein subpopulation profiles in mixed hyperlipoproteinemia.

PubMed

Saïdi, Y; Sich, D; Camproux, A; Egloff, M; Federspiel, M C; Gautier, V; Raisonnier, A; Turpin, G; Beucler, I

1999-01-01

We studied the relationships postprandially between triglyceride-rich lipoprotein (TRL) and high-density lipoprotein (HDL) in 11 mixed hyperlipoproteinemia (MHL) and 11 hypercholesterolemia (HCL) patients. The high and prolonged postprandial triglyceridemia response observed in MHL but not HCL patients was essentially dependent on very-low-density lipoprotein (VLDL) changes. This abnormal response was related to decreased lipoprotein lipase (LPL) activity (-48.7%, P<.01) in MHL compared with HCL subjects. Cholesteryl ester transfer protein (CETP) activity was postprandially enhanced only in MHL patients, and this elevation persisted in the late period (+19% at 12 hours, P<.05), sustaining the delayed enrichment of VLDL with cholesteryl ester (CE). The late postprandial period in MHL patients was also characterized by high levels of apolipoprotein B (apoB)-containing lipoproteins with apoCIII ([LpB:CIII] +36% at 12 hours, P<.01) and decreased levels of apoCIII contained in HDL ([LpCIII-HDL] -34% at 12 hours, P<.01), reflecting probably a defective return of apoCIII from TRL toward HDL. In MHL compared with HCL patients, decreased HDL2 levels were related to both HDL2b and HDL2a subpopulations (-57% and -49%, respectively, P<.01 for both) and decreased apoA-I levels (-53%, P<.01) were equally linked to decreased HDL2 with apoA-I only (LpA-I) and HDL2 with both apoA-I and apoA-II ([LpA-I:A-II] -55% and -52%, respectively, P<.01 for both). The significant inverse correlations between the postprandial magnitude of LpB:CIII and HDL2-LpA-I and HDL2b levels in MHL patients underline the close TRL-HDL interrelationships. Our findings indicate that TRL and HDL abnormalities evidenced at fasting were postprandially amplified, tightly interrelated, and persistent during the late fed period in mixed hyperlipidemia. Thus, these fasting abnormalities are likely postprandially originated and may constitute proatherogenic lipoprotein disorders additional to the HCL in MHL patients.

Vitamin E tocotrienol supplementation improves lipid profiles in chronic hemodialysis patients

PubMed Central

Daud, Zulfitri A Mat; Tubie, Boniface; Sheyman, Marina; Osia, Robert; Adams, Judy; Tubie, Sharon; Khosla, Pramod

2013-01-01

Purpose Chronic hemodialysis patients experience accelerated atherosclerosis contributed to by dyslipidemia, inflammation, and an impaired antioxidant system. Vitamin E tocotrienols possess anti-inflammatory and antioxidant properties. However, the impact of dietary intervention with Vitamin E tocotrienols is unknown in this population. Patients and methods A randomized, double-blind, placebo-controlled, parallel trial was conducted in 81 patients undergoing chronic hemodialysis. Subjects were provided daily with capsules containing either vitamin E tocotrienol-rich fraction (TRF) (180 mg tocotrienols, 40 mg tocopherols) or placebo (0.48 mg tocotrienols, 0.88 mg tocopherols). Endpoints included measurements of inflammatory markers (C-reactive protein and interleukin 6), oxidative status (total antioxidant power and malondialdehyde), lipid profiles (plasma total cholesterol, triacylglycerols, and high-density lipoprotein cholesterol), as well as cholesteryl-ester transfer protein activity and apolipoprotein A1. Results TRF supplementation did not impact any nutritional, inflammatory, or oxidative status biomarkers over time when compared with the baseline within the group (one-way repeated measures analysis of variance) or when compared with the placebo group at a particular time point (independent t-test). However, the TRF supplemented group showed improvement in lipid profiles after 12 and 16 weeks of intervention when compared with placebo at the respective time points. Normalized plasma triacylglycerols (cf baseline) in the TRF group were reduced by 33 mg/dL (P=0.032) and 36 mg/dL (P=0.072) after 12 and 16 weeks of intervention but no significant improvement was seen in the placebo group. Similarly, normalized plasma high-density lipoprotein cholesterol was higher (P<0.05) in the TRF group as compared with placebo at both week 12 and week 16. The changes in the TRF group at week 12 and week 16 were associated with higher plasma apolipoprotein A1 concentration (P<0.02) and lower cholesteryl-ester transfer protein activity (P<0.001). Conclusion TRF supplementation improved lipid profiles in this study of maintenance hemodialysis patients. A multi-centered trial is warranted to confirm these observations. PMID:24348043

Disruption of Human Plasma High Density Lipoproteins by Streptococcal Serum Opacity Factor Requires Labile Apolipoprotein A-I

PubMed Central

Han, Mikyung; Gillard, Baiba K.; Courtney, Harry S.; Ward, Kathryn; Rosales, Corina; Khant, Htet; Ludtke, Steven J.; Pownall, Henry J.

2010-01-01

Human plasma high density lipoproteins (HDL), the primary vehicle for reverse cholesterol transport, are the target of serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes that turns serum opaque. HDL comprise a core of neutral lipids–cholesteryl esters and some triglyceride–surrounded by a surface monolayer of cholesterol, phospholipids, and specialized proteins–apolipoproteins (apos) A-I and A-II. HDL is an unstable particle residing in a kinetic trap from which it can escape via chaotropic, detergent or thermal perturbation. Recombinant (r) SOF catalyzes the transfer of nearly all neutral lipids of ~100,000 HDL particles (D ~ 8.5 nm) into a single, large cholesteryl ester-rich microemulsion (CERM; D >100 nm) leaving a new HDL-like particle–neo HDL (D ~5.8 nm) while releasing lipid-free (LF) apo A-I. CERM formation and apo A-I release have similar kinetics suggesting parallel or rapid consecutive steps. By using complementary physico-chemical methods, we have refined the mechanistic model for HDL opacification. According to size exclusion chromatography, HDL containing non-labile apo A-I resists rSOF-mediated opacification. Based on kinetic cryo electron microscopy, rSOF (10 nM) catalyzes the conversion of HDL (4 μM) to neo HDL via a step-wise mechanism in which intermediate-size particles are seen. Kinetic turbidimetry revealed opacification as a rising exponential reaction with a rate constant k = (4.400 ± 0.004) × 10−2 min−1. Analysis of the kinetic data using transition state theory gave an enthalpy, entropy and free energy of activation of ΔH‡ = 73.9 kJ/mol, ΔS‡ = −66.87 J/°K, and ΔG‡ = 94.6 kJ/mol respectively. The free energy of activation for opacification is nearly identical to that for the displacement of apo A-I from HDL by guanidine hydrochloride. We conclude that apo A-I lability is required for HDL opacification, LF apo A-I desorption is the rate-limiting step, and nearly all HDL particles contain at least one labile copy of apo A-I. PMID:19191587

PEGylation of supercooled smectic cholesteryl myristate nanoparticles.

PubMed

Mengersen, Friederike; Bunjes, Heike

2012-06-01

Supercooled smectic cholesterol ester nanoparticles are under investigation as a new carrier system for lipophilic drugs. The smectic thermotropic liquid crystalline state of the matrix lipid is expected to lead to advantages with respect to physicochemical stability and drug loading capacity. Such nanoparticles can be prepared by high-pressure melt homogenization in the presence of emulsifiers. The purpose of this study was to develop PEGylated supercooled smectic cholesteryl myristate nanoparticles for parenteral administration and to provide evidence of the successful PEGylation by detecting the alterations of particle properties due to the insertion of PEGylated phospholipid into the surface layer of the particles. To achieve PEGylation, MPEG(2000)-DSPE was processed together with the phospholipids used as emulsifiers during particle preparation. The influence of the PEGylated phospholipid on the size, zeta potential, phase behavior and recrystallization tendency of the nanoparticles indicated the insertion of MPEG(2000)-DSPE into the surface layer of the particles. Evidence of the PEGylation was also obtained by (1)H NMR measurements, and the steric stabilization was verified by neutralizing the particle surface charge with calcium chloride or adjusting the pH value. As sterility is an important aspect with regard to parenteral administration of the dispersions their stability upon autoclaving was a further point of interest in the present study. The results indicate that PEGylated particles can be sterilized by autoclaving. In conclusion, the PEGylated particles are a promising formulation with respect to small particle size, stability against recrystallization and upon autoclaving. Copyright © 2012 Elsevier B.V. All rights reserved.

The spectrophotometric sulfo-phospho-vanillin assessment of total lipids in human meibomian gland secretions.

PubMed

McMahon, Anne; Lu, Hua; Butovich, Igor A

2013-05-01

Human meibomian gland secretions (meibum) are the major lipid component of the human preocular tear film. The predominant lipid classes found in meibum include waxes (WE), cholesteryl esters (CE), and varying amounts of cholesterol (Chl). The classical sulfo-phospho-vanillin assay (SPVA), adapted for a microplate reader, was used to quantitate lipids in meibum. To account for varying reactivities of different lipids in SPVA, a model meibomian lipid mixture (MMx) that approximated the WE/CE/Chl composition of meibum was developed and used to quantitate meibomian lipids. The overall SPV responses of MMx and meibum were found to be close, with similar intermediate and final reaction products for both. Saturated WE that had not been expected to be reactive were found to be SPV-positive. A reaction mechanism for these compounds in SPVA which involves the formation of alkenyl ethers is proposed and discussed. Tested proteins were non-reactive in SPVA. Thus, by comparing the results of gravimetric analyses of meibum samples with the results of a properly calibrated SPVA, it was estimated that the SPV-reactive lipid content of dry meibum in tested samples was about 78 % (w/w). The SPV method can also be adopted for analyzing other types of complex lipids secretions, such as sebum, as well as whole lipid extracts from other lipid-enriched organs and tissues, if proper standards are chosen.

The Spectrophotometric Sulfo-Phospho-Vanillin Assessment of Total Lipids in Human Meibomian Gland Secretions

PubMed Central

McMahon, Anne; Lu, Hua

2013-01-01

Human meibomian gland secretions (meibum) are the major lipid component of the human preocular tear film. The predominant lipid classes found in meibum include waxes (WE), cholesteryl esters (CE), and varying amounts of cholesterol (Chl). The classical sulfo-phospho-vanillin assay (SPVA), adapted for a microplate reader, was used to quantitate lipids in meibum. To account for varying reactivities of different lipids in SPVA, a model meibomian lipid mixture (MMx) that approximated the WE/CE/Chl composition of meibum was developed and used to quantitate meibomian lipids. The overall SPV responses of MMx and meibum were found to be close, with similar intermediate and final reaction products for both. Saturated WE that had not been expected to be reactive were found to be SPV-positive. A reaction mechanism for these compounds in SPVA which involves the formation of alkenyl ethers is proposed and discussed. Tested proteins were non-reactive in SPVA. Thus, by comparing the results of gravimetric analyses of meibum samples with the results of a properly calibrated SPVA, it was estimated that the SPV-reactive lipid content of dry meibum in tested samples was about 78 % (w/w). The SPV method can also be adopted for analyzing other types of complex lipids secretions, such as sebum, as well as whole lipid extracts from other lipid-enriched organs and tissues, if proper standards are chosen. PMID:23345137

Serum Opacity Factor Enhances HDL-Mediated Cholesterol Efflux, Esterification and Anti Inflammatory Effects

PubMed Central

Tchoua, Urbain; Rosales, Corina; Tang, Daming; Gillard, Baiba K.; Vaughan, Ashley; Lin, Hu Yu; Courtney, Harry S.

2011-01-01

Serum opacity factor (SOF) is a streptococcal protein that disrupts the structure of human high density lipoproteins (HDL) releasing lipid-free apo A-I while forming a large cholesteryl ester-rich particle and a small neo HDL. Given its low cholesterol and high phospholipid contents, we tested the hypotheses that neo HDL is a better substrate for cholesterol esterification via lecithin:cholesterol acyltransferase (LCAT), better than HDL as an acceptor of THP-1 macrophage cholesterol efflux, and improves reduction of oxidized LDL-induced production of inflammatory markers. We observed that both cholesterol efflux and esterification were improved by recombinant (r)SOF treatment of whole plasma and that the underlying cause of the improved cholesterol esterification in plasma and macrophage cholesterol efflux to rSOF-treated plasma was due to the rSOF-mediated conversion of HDL to neo HDL. Moreover, the reduction of secretion of TNF-α and IL-6 by THP-1 cells by neo HDL was twice that of HDL. Studies in BHK cells overexpressing cholesterol transporters showed that efflux to neo HDL occurred primarily via ABCA1 not ABCG1. Thus, rSOF improves two steps in reverse cholesterol transport with a concomitant reduction in the release of macrophage markers of inflammation. We conclude that rSOF catalyzes a novel reaction that might be developed as a new therapy that prevents or reverses atherosclerosis via improved reverse cholesterol transport. PMID:20972840

Echium Oil Reduces Plasma Triglycerides by Increasing Intravascular Lipolysis in apoB100-Only Low Density Lipoprotein (LDL) Receptor Knockout Mice

PubMed Central

Forrest, Lolita M.; Lough, Christopher M.; Chung, Soonkyu; Boudyguina, Elena Y.; Gebre, Abraham K.; Smith, Thomas L.; Colvin, Perry L.; Parks, John S.

2013-01-01

Echium oil (EO), which is enriched in SDA (18:4 n-3), reduces plasma triglyceride (TG) concentrations in humans and mice. We compared mechanisms by which EO and fish oil (FO) reduce plasma TG concentrations in mildly hypertriglyceridemic male apoB100-only LDLrKO mice. Mice were fed one of three atherogenic diets containing 0.2% cholesterol and palm oil (PO; 20%), EO (10% EO + 10% PO), or FO (10% FO + 10% PO). Livers from PO- and EO-fed mice had similar TG and cholesteryl ester (CE) content, which was significantly higher than in FO-fed mice. Plasma TG secretion was reduced in FO vs. EO-fed mice. Plasma very low density lipoprotein (VLDL) particle size was ordered: PO (63 ± 4 nm) > EO (55 ± 3 nm) > FO (40 ± 2 nm). Post-heparin lipolytic activity was similar among groups, but TG hydrolysis by purified lipoprotein lipase was significantly greater for EO and FO VLDL compared to PO VLDL. Removal of VLDL tracer from plasma was marginally faster in EO vs. PO fed mice. Our results suggest that EO reduces plasma TG primarily through increased intravascular lipolysis of TG and VLDL clearance. Finally, EO may substitute for FO to reduce plasma TG concentrations, but not hepatic steatosis in this mouse model. PMID:23857172

Echium oil reduces plasma triglycerides by increasing intravascular lipolysis in apoB100-only low density lipoprotein (LDL) receptor knockout mice.

PubMed

Forrest, Lolita M; Lough, Christopher M; Chung, Soonkyu; Boudyguina, Elena Y; Gebre, Abraham K; Smith, Thomas L; Colvin, Perry L; Parks, John S

2013-07-12

Echium oil (EO), which is enriched in SDA (18:4 n-3), reduces plasma triglyceride (TG) concentrations in humans and mice. We compared mechanisms by which EO and fish oil (FO) reduce plasma TG concentrations in mildly hypertriglyceridemic male apoB100-only LDLrKO mice. Mice were fed one of three atherogenic diets containing 0.2% cholesterol and palm oil (PO; 20%), EO (10% EO + 10% PO), or FO (10% FO + 10% PO). Livers from PO- and EO-fed mice had similar TG and cholesteryl ester (CE) content, which was significantly higher than in FO-fed mice. Plasma TG secretion was reduced in FO vs. EO-fed mice. Plasma very low density lipoprotein (VLDL) particle size was ordered: PO (63 ± 4 nm) > EO (55 ± 3 nm) > FO (40 ± 2 nm). Post-heparin lipolytic activity was similar among groups, but TG hydrolysis by purified lipoprotein lipase was significantly greater for EO and FO VLDL compared to PO VLDL. Removal of VLDL tracer from plasma was marginally faster in EO vs. PO fed mice. Our results suggest that EO reduces plasma TG primarily through increased intravascular lipolysis of TG and VLDL clearance. Finally, EO may substitute for FO to reduce plasma TG concentrations, but not hepatic steatosis in this mouse model.

Chemoproteomic Profiling of Acetanilide Herbicides Reveals Their Role in Inhibiting Fatty Acid Oxidation.

PubMed

Counihan, Jessica L; Duckering, Megan; Dalvie, Esha; Ku, Wan-Min; Bateman, Leslie A; Fisher, Karl J; Nomura, Daniel K

2017-03-17

Acetanilide herbicides are among the most widely used pesticides in the United States, but their toxicological potential and mechanisms remain poorly understood. Here, we have used chemoproteomic platforms to map proteome-wide cysteine reactivity of acetochlor (AC), the most widely used acetanilide herbicide, in vivo in mice. We show that AC directly reacts with >20 protein targets in vivo in mouse liver, including the catalytic cysteines of several thiolase enzymes involved in mitochondrial and peroxisomal fatty acid oxidation. We show that the fatty acids that are not oxidized, due to impaired fatty acid oxidation, are instead diverted into other lipid pathways, resulting in heightened free fatty acids, triglycerides, cholesteryl esters, and other lipid species in the liver. Our findings show the utility of chemoproteomic approaches for identifying novel mechanisms of toxicity associated with environmental chemicals like acetanilide herbicides.

Sudan stain of fecal fat: new insight into an old test.

PubMed

Khouri, M R; Huang, G; Shiau, Y F

1989-02-01

The 72-h fecal fat determination is used as the gold standard to document the presence of steatorrhea. Although the Sudan stain for fecal fat is advocated as a sensitive screening test, a quantitative correlation between the 72-h fecal fat quantitation and the fecal Sudan stain is lacking. This study was designed to examine the staining properties of different classes of purified lipids in an experimentally defined artificial matrix, and to elucidate the reasons for the lack of quantitative correlation between these two tests. Our results indicate that the "neutral fat" stain without acidification or heating identifies triglyceride; and at an appropriate pH, the "neutral stain" also identifies fatty acid. The "split fat" stain with acidification and heating identifies both triglyceride and fatty acid. After acidification, fatty acid soaps are converted to the nonionized fatty acid. Thus, fatty acid soaps can be identified indirectly as fat droplets that are stained by the split fat stain. Although cholesterol is stained with Sudan stain after heating, upon cooling, cholesterol forms crystals of anhydrous cholesterol, making its staining pattern distinct. Neither the neutral fat nor the split fat stain can detect phospholipid or cholesteryl ester. The 72-h fecal fat determination is a measure of the total fatty acid content after a specimen is saponified. The resulting fatty acids are derived from a variety of endogenous and exogenous sources, including free fatty acids, soaps of fatty acids, triglycerides, cholesterol esters, and phospholipids. Therefore, the 72-h fecal fat quantitation does not differentiate between the primary sources of the measured fatty acid. It is concluded that the 72-h fecal fat determination is not specific for documenting triglyceride (fat) malabsorption. Until new methods are developed that specifically measure fecal triglyceride and fatty acid, the Sudan stain of fecal fat appears to be a more specific method for detecting the presence of triglyceride and fatty acid in a matrix.

Mechanism of formation of 3-chloropropan-1,2-diol (3-MCPD) esters under conditions of the vegetable oil refining.

PubMed

Šmidrkal, Jan; Tesařová, Markéta; Hrádková, Iveta; Berčíková, Markéta; Adamčíková, Aneta; Filip, Vladimír

2016-11-15

3-MCPD esters are contaminants that can form during refining of vegetable oils in the deodorization step. It was experimentally shown that their content in the vegetable oil depends on the acid value of the vegetable oil and the chloride content. 3-MCPD esters form approximately 2-5 times faster from diacylglycerols than from monoacylglycerols. It has been proved that the higher fatty acids content in the oil caused higher 3-MCPD esters content in the deodorization step. Neutralization of free fatty acids in the vegetable oil before the deodorization step by alkaline carbonates or hydrogen carbonates can completely suppress the formation of 3-MCPD esters. Potassium salts are more effective than sodium salts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential effects of simple vs. complex carbohydrates on VLDL secretion rates and HDL metabolism in the guinea pig.

PubMed

Fernandez, M L; Abdel-Fattah, G; McNamara, D J

1995-04-28

Guinea pigs were fed isocaloric diets containing 52% (w/w) carbohydrate, either sucrose or starch, to investigate effects of simple vs. complex carbohydrates on plasma VLDL and HDL metabolism. Plasma cholesterol concentrations were not different between dietary groups while plasma triacylglycerol (TAG) and VLDL cholesterol levels were significantly increased in animals fed the sucrose diet (P < 0.05). Hepatic VLDL TAG secretion rates measured following intravenous injection of Triton WR-1339 were not affected by carbohydrate type whereas the rate of apo B secretion was 1.9-fold higher in sucrose fed animals (P < 0.02). Nascent VLDL from the sucrose group contained less TAG per apo B suggesting that the higher plasma TAG in animals fed simple carbohydrates results from increased secretion of VLDL particles with lower TAG content. Sucrose fed animals exhibited higher concentrations of hepatic free cholesterol (P < 0.01) while hepatic TAG levels and acyl CoA:cholesterol acyltransferase (ACAT) activity were not different between groups. Plasma HDL cholesterol concentrations and composition, and plasma lecithin cholesterol acyltransferase (LCAT) activity were not affected by diet yet there was a positive correlation between HDL cholesteryl ester content and LCAT activities (r = 0.70, P < 0.05). Hepatic membranes from the sucrose group had a higher hepatic HDL binding protein number (Bmax) with no changes in the dissociation constant (Kd). These results suggest that at the same carbohydrate energy intake, simple sugars induce modest changes in HDL metabolism while VLDL metabolism is affected at multiple sites, as indicated by the higher concentrations of hepatic cholesterol, dissociation in the synthesis rates of VLDL components, and compositional changes in nascent and mature VLDL.

Triglyceride enrichment of HDL enhances in vivo metabolic clearance of HDL apo A-I in healthy men

PubMed Central

Lamarche, Benoît; Uffelman, Kristine D.; Carpentier, André; Cohn, Jeffrey S.; Steiner, George; Barrett, P. Hugh; Lewis, Gary F.

1999-01-01

Triglyceride (TG) enrichment of HDL resulting from cholesteryl ester transfer protein–mediated exchange with TG-rich lipoproteins may enhance the lipolytic transformation and subsequent metabolic clearance of HDL particles in hypertriglyceridemic states. The present study investigates the effect of TG enrichment of HDL on the clearance of HDL-associated apo A-I in humans. HDL was isolated from plasma of six normolipidemic men (mean age: 29.7 ± 2.7 years) in the fasting state and after a five-hour intravenous infusion with a synthetic TG emulsion, Intralipid. Intralipid infusion resulted in a 2.1-fold increase in the TG content of HDL. Each tracer was then whole-labeled with 125I or 131I and injected intravenously into the subject. Apo A-I in TG-enriched HDL was cleared 26% more rapidly than apo A-I in fasting HDL. A strong correlation between the Intralipid-induced increase in the TG content of HDL and the increase in HDL apo A-I fractional catabolic rate reinforced the importance of TG enrichment of HDL in enhancing its metabolic clearance. HDL was separated further into lipoproteins containing apo A-II (LpAI:AII) and those without apo A-II (LpAI). Results revealed that the enhanced clearance of apo A-I from TG-enriched HDL could be largely attributed to differences in the clearance of LpAI but not LpAI:AII. This is, to our knowledge, the first direct demonstration in humans that TG enrichment of HDL enhances the clearance of HDL apo A-I from the circulation. This phenomenon could provide an important mechanism explaining how HDL apo A-I and HDL cholesterol are lowered in hypertriglyceridemic states. PMID:10207171

Free and esterified oxysterol: formation during copper-oxidation of low density lipoprotein and uptake by macrophages.

PubMed

Brown, A J; Dean, R T; Jessup, W

1996-02-01

We have defined the lipid composition of copper-oxidized LDL (Cu-oxLDL) and a macrophage-foam cell model generated by the uptake of this modified lipoprotein. An HPLC method previously developed by our group for the measurement of lipid oxidation products of LDL was extended to permit the analysis of an array of 7-ketocholesteryl esters. Gas chromatography was used for the quantitation of oxysterols (free and esterified) in Cu-oxLDL and their subsequent uptake by macrophages. LDL (1.0 mg protein/ml) was oxidized using Cu(II) (20 microM) for up to 48 h at 37 degrees C. Resident mouse peritoneal macrophages were incubated with 24 h Cu-oxLDL (50 micrograms/ml) for 24 h. In 24 h Cu-oxLDL, cholesterol comprised approximately 50% of total sterols, 7-ketocholesterol comprised approximately 30% with five other oxysterols comprising the remainder (7 alpha- and 7 beta-hydroxycholesterol, cholesterol alpha- and beta-epoxides, and 6 beta-hydroxycholesterol). Macrophages that were incubated with 24 h Cu-oxLDL displayed a profile of oxysterols remarkably similar to that of 24 h Cu-oxLDL itself. The majority of cholesteryl esters and 7-ketocholesteryl esters in Cu-oxLDL and in Cu-oxLDL-loaded macrophages contained fatty acyl chains which are presumed oxidized. This work represents a comprehensive survey of free and esterified oxysterols in Cu-oxLDL and Cu-oxLDL-loaded macrophages and provides a basis for exploring how oxysterols are metabolized by macrophages and authentic human foam cells, and how, in turn, these oxysterols influence cellular metabolism.

The effect of raw materials on thermo-oxidative stability and glycidyl ester content of palm oil during frying.

PubMed

Aniołowska, Magda A; Kita, Agnieszka M

2016-04-01

The objective of this research was to determine the effects of the water content of food incorporated into frying oil on oil degradation and the content of glycidyl esters. Potato chips, French fries and snacks were fried intermittently in palm oil, which was heated at 180 °C for 8 h per day over five consecutive days. Thermo-oxidative and physical alterations, changes in fatty acid composition, total polar components, polar fraction composition, and water content were analysed. The content of glycidyl esters was measured by liquid chromatography-tandem mass spectrometry. More polar compounds were formed in the oil used for frying chips (252 g kg(-1)) than for French fries (229 g kg(-1)) or snacks (196 g kg(-1)). Reductions in glycidyl esters were found in oils used for frying--greater for frying snacks and French fries (95% and 93%) than for potato chips (87%). The rate of decrease of glycidyl esters was correlated with frying parameters, most strongly with the concentrations of diacylglycerols (r = 0.98) and total polar components (r = -0.98). The raw material had a greater influence on polymerization conversion and glycidyl ester content than on hydrolytic and oxidative changes in the frying oil. © 2015 Society of Chemical Industry.

A facile synthesis and carbon-13 nuclear magnetic resonance spectral properties of 7-ketocholesteryl benzoate.

PubMed

Parish, E J; Wei, T Y; Livant, P

1987-10-01

This paper presents a modified method of the selective allylic oxidation of cholesteryl benzoate. Pyridinium chlorochromate, in refluxing benzene, has been found to be an effective and convenient reagent for the efficient oxidation of cholesteryl benzoate to 7-ketocholesteryl benzoate in high yield. Also included herein are the carbon-13 nuclear magnetic resonance spectral properties of 7-ketocholesteryl benzoate and cholesteryl benzoate.

Effects of Stigmasterol and β-Sitosterol on Nonalcoholic Fatty Liver Disease in a Mouse Model: A Lipidomic Analysis.

PubMed

Feng, Simin; Gan, Ling; Yang, Chung S; Liu, Anna B; Lu, Wenyun; Shao, Ping; Dai, Zhuqing; Sun, Peilong; Luo, Zisheng

2018-04-04

To study the effects of stigmasterol and β-sitosterol on high-fat Western diet (HFWD)-induced nonalcoholic fatty liver disease (NAFLD), lipidomic analyses were conducted in liver samples collected after 33 weeks of the treatment. Principal component analysis showed these phytosterols were effective in protecting against HFWD-induced NAFLD. Orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and S-plots showed that triacylglycerols (TGs), phosphatidylcholines, cholesteryl esters, diacylglycerols, and free fatty acids (FFAs) were the major lipid species contributing to these discriminations. The alleviation of NAFLD is mainly associated with decreases in hepatic cholesterol, TGs with polyunsaturated fatty acids, and alterations of free hepatic FFA. In conclusion, phytosterols, at a dose comparable to that suggested for humans by the FDA for the reduction of plasma cholesterol levels, are shown to protect against NAFLD in this long-term (33-week) study.

Progress and future opportunities in the development of vaccines against atherosclerosis.

PubMed

Govea-Alonso, Dania O; Beltrán-López, Josué; Salazar-González, Jorge A; Vargas-Morales, Juan; Rosales-Mendoza, Sergio

2017-04-01

Atherosclerosis represents a serious global health problem that demands new therapeutic and prophylactic interventions. Considering that atherosclerosis has autoimmune and inflammatory components, immunotherapy is a possible focus to treat this disease. Areas covered: Based on the analysis of the current biomedical literature, this review describes the status on the development of vaccines against atherosclerosis. Several targets have been identified including sequences of apolipoprotein B100 (ApoB100), cholesteryl ester transfer protein (CETP), heat shock proteins (HSP), extracellular matrix proteins, T cell receptor β chain variable region 31 (TRBV31), the major outer membrane protein (MOMP), and the outer membrane protein 5 (Pomp5) from Chlamydia pneumoniae. Humoral and cellular immunities to these targets have been associated with therapeutic effects in murine models and humans. The evaluation of some candidates in clinical trials is ongoing. Expert commentary: New research paths based on the use of next generation vaccine production platforms are envisioned.

Mapping Proteome-wide Targets of Glyphosate in Mice.

PubMed

Ford, Breanna; Bateman, Leslie A; Gutierrez-Palominos, Leilani; Park, Robin; Nomura, Daniel K

2017-02-16

Glyphosate, the active ingredient in the herbicide Roundup, is one of the most widely used pesticides in agriculture and home garden use. Whether glyphosate causes any mammalian toxicity remains highly controversial. While many studies have associated glyphosate with numerous adverse health effects, the mechanisms underlying glyphosate toxicity in mammals remain poorly understood. Here, we used activity-based protein profiling to map glyphosate targets in mice. We show that glyphosate at high doses can be metabolized in vivo to reactive metabolites such as glyoxylate and react with cysteines across many proteins in mouse liver. We show that glyoxylate inhibits liver fatty acid oxidation enzymes and glyphosate treatment in mice increases the levels of triglycerides and cholesteryl esters, likely resulting from diversion of fatty acids away from oxidation and toward other lipid pathways. Our study highlights the utility of using chemoproteomics to identify novel toxicological mechanisms of environmental chemicals such as glyphosate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increase of medium-chain fatty acid ethyl ester content in mixed H. uvarum/S. cerevisiae fermentation leads to wine fruity aroma enhancement.

PubMed

Hu, Kai; Jin, Guo-Jie; Mei, Wen-Chao; Li, Ting; Tao, Yong-Sheng

2018-01-15

Medium-chain fatty acid (MCFA) ethyl esters, as yeast secondary metabolites, significantly contribute to the fruity aroma of foods and beverages. To improve the MCFA ethyl ester content of wine, mixed fermentations with Hanseniaspora uvarum Yun268 and Saccharomyces cerevisiae were performed. Final volatiles were analyzed by gas solid phase microextraction-chromatography-mass spectrometry, and aroma characteristics were quantitated by sensory analysis. Results showed that mixed fermentation increased MCFA ethyl ester content by 37% in Cabernet Gernischt wine compared to that obtained by pure fermentation. Partial least-squares regression analysis further revealed that the improved MCFA ethyl esters specifically enhanced the temperate fruity aroma of wine. The enhancement of MCFA ethyl esters was attributed to the increased contents of MCFAs that could be induced by the presence of H. uvarum Yun268 in mixed fermentation. Meanwhile, the timing of yeast inoculations significantly affected the involving biomass of each strain and the dynamics of ethanol accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

LOSS OF L-FABP, SCP-2/SCP-X, OR BOTH INDUCES HEPATIC LIPID ACCUMULATION IN FEMALE MICE

PubMed Central

Martin, Gregory G.; Atshaves, Barbara P.; Landrock, Kerstin K.; Landrock, Danilo; Schroeder, Friedhelm; Kier, Ann B.

2015-01-01

Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals—suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD). PMID:26116377

Mediterranean Diet Improves High-Density Lipoprotein Function in High-Cardiovascular-Risk Individuals: A Randomized Controlled Trial.

PubMed

Hernáez, Álvaro; Castañer, Olga; Elosua, Roberto; Pintó, Xavier; Estruch, Ramón; Salas-Salvadó, Jordi; Corella, Dolores; Arós, Fernando; Serra-Majem, Lluis; Fiol, Miquel; Ortega-Calvo, Manuel; Ros, Emilio; Martínez-González, Miguel Ángel; de la Torre, Rafael; López-Sabater, M Carmen; Fitó, Montserrat

2017-02-14

The biological functions of high-density lipoproteins (HDLs) contribute to explaining the cardioprotective role of the lipoprotein beyond quantitative HDL cholesterol levels. A few small-scale interventions with a single antioxidant have improved some HDL functions. However, to date, no long-term, large-scale, randomized controlled trial has been conducted to assess the effects of an antioxidant-rich dietary pattern (such as a traditional Mediterranean diet [TMD]) on HDL function in humans. This study was performed in a random subsample of volunteers from the PREDIMED Study (Prevención con Dieta Mediterránea; n=296) after a 1-year intervention. We compared the effects of 2 TMDs, one enriched with virgin olive oil (TMD-VOO; n=100) and the other enriched with nuts (TMD-Nuts; n=100), with respect to a low-fat control diet (n=96). We assessed the effects of both TMDs on the role of HDL particles on reverse cholesterol transport (cholesterol efflux capacity, HDL ability to esterify cholesterol, and cholesteryl ester transfer protein activity), HDL antioxidant properties (paraoxonase-1 arylesterase activity and total HDL antioxidant capacity on low-density lipoproteins), and HDL vasodilatory capacity (HDL ability to induce the release of nitric oxide in endothelial cells). We also studied the effects of a TMD on several HDL quality-related characteristics (HDL particle oxidation, resistance against oxidative modification, main lipid and protein composition, and size distribution). Both TMDs increased cholesterol efflux capacity relative to baseline ( P =0.018 and P =0.013 for TMD-VOO and TMD-Nuts, respectively). The TMD-VOO intervention decreased cholesteryl ester transfer protein activity (relative to baseline, P =0.028) and increased HDL ability to esterify cholesterol, paraoxonase-1 arylesterase activity, and HDL vasodilatory capacity (relative to control, P =0.039, P =0.012, and P =0.026, respectively). Adherence to a TMD induced these beneficial changes by improving HDL oxidative status and composition. The 3 diets increased the percentage of large HDL particles (relative to baseline, P <0.001). The TMD, especially when enriched with virgin olive oil, improved HDL atheroprotective functions in humans. URL: http://www.controlled-trials.com. Unique identifier: ISRCTN35739639. © 2017 American Heart Association, Inc.

Orally administered glycidol and its fatty acid esters as well as 3-MCPD fatty acid esters are metabolized to 3-MCPD in the F344 rat.

PubMed

Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Akagi, Jun-ichi; Fujiwara, Satoshi; Ochiai, Ryosuke; Tsujino, Kazushige; Nishikawa, Akiyoshi; Ogawa, Kumiko

2015-12-01

IARC has classified glycidol and 3-monochloropropane-1,2-diol (3-MCPD) as group 2A and 2B, respectively. Their esters are generated in foodstuffs during processing and there are concerns that they may be hydrolyzed to the carcinogenic forms in vivo. Thus, we conducted two studies. In the first, we administered glycidol and 3-MCPD and associated esters (glycidol oleate: GO, glycidol linoleate: GL, 3-MCPD dipalmitate: CDP, 3-MCPD monopalmitate: CMP, 3-MCPD dioleate: CDO) to male F344 rats by single oral gavage. After 30 min, 3-MCPD was detected in serum from all groups. Glycidol was detected in serum from the rats given glycidol or GL and CDP and CDO in serum from rats given these compounds. In the second, we examined if metabolism occurs on simple reaction with rat intestinal contents (gastric, duodenal and cecal contents) from male F344 gpt delta rats. Newly produced 3-MCPD was detected in all gut contents incubated with the three 3-MCPD fatty acid esters and in gastric and duodenal contents incubated with glycidol and in duodenal and cecal contents incubated with GO. Although our observation was performed at 1 time point, the results showed that not only 3-MCPD esters but also glycidol and glycidol esters are metabolized into 3-MCPD in the rat. Copyright © 2015 Elsevier Inc. All rights reserved.

Simultaneous Quantification of Free Cholesterol, Cholesteryl Esters, and Triglycerides without Ester Hydrolysis by UHPLC Separation and In-Source Collision Induced Dissociation Coupled MS/MS

NASA Astrophysics Data System (ADS)

Gardner, Michael S.; McWilliams, Lisa G.; Jones, Jeffrey I.; Kuklenyik, Zsuzsanna; Pirkle, James L.; Barr, John R.

2017-08-01

We demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 μL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot. Known representative mixtures of EC and TG species were used as calibrators with stable isotope labeled analogs as internal standards. The APCI MS source was operated with nitrogen source gas. Reproducible in-source CID was achieved with the use of optimal cone voltage (declustering potential), generating FC, EC, and TG lipid class-specific precursor fragment ions for multiple reaction monitoring (MRM). Using a representative mixture of purified FC, CE, and TG species as calibrators, the method accuracy was assessed with analysis of five inter-laboratory standardization materials, showing -10% bias for Total-C and -3% for Total-TG. Repeated duplicate analysis of a quality control pool showed intra-day and inter-day variation of 5% and 5.8% for FC, 5.2% and 8.5% for Total-C, and 4.1% and 7.7% for Total-TG. The applicability of the method was demonstrated on 32 serum samples and corresponding lipoprotein sub-fractions collected from normolipidemic, hypercholesterolemic, hypertriglyceridemic, and hyperlipidemic donors. The results show that in-source CID coupled with isotope dilution UHPLC-MS/MS is a viable high precision approach for translational research studies where samples are substantially diluted or the amounts of archived samples are limited. [Figure not available: see fulltext.

Addition products of alpha-tocopherol with lipid-derived free radicals.

PubMed

Yamauchi, Ryo

2007-01-01

The addition products of alpha-tocopherol with lipid-derived free radicals have been reviewed. Free radical scavenging reactions of alpha-tocopherol take place via the alpha-tocopheroxyl radical as an intermediate. If a suitable free radical is present, an addition product can be formed from the coupling of the free radical with the alpha-tocopheroxyl radical. The addition products of alpha-tocopherol with lipid-peroxyl radicals are 8a-(lipid-dioxy)-alpha-tocopherones, which are hydrolyzed to alpha-tocopherylquinone. On the other hand, the carbon-centered radicals of lipids prefer to react with the phenoxyl radical of alpha-tocopherol to form 6-O-lipid-alpha-tocopherol under anaerobic conditions. The addition products of alpha-tocopherol with peroxyl radicals (epoxylinoleoyl-peroxyl radicals) produced from cholesteryl ester and phosphatidylcholine were detected in the peroxidized human plasma using a high-sensitive HPLC procedure with postcolumn reduction and electrochemical detection. Thus, the formation of these addition products provides us with much information on the antioxidant function of vitamin E in biological systems.

3 Benzyl-6-chloropyrone: a suicide inhibitor of cholesterol esterase

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

Saint, C.; Gallo, I.; Kantorow, M.

Cholesterol, absorbed from the intestine, appears in lymph as the ester. Cholesterol esterase is essential for this process, since depletion of the enzyme blocks and repletion restores, absorption. Selective inhibitors of cholesterol esterase may thus prove useful in reducing cholesterol uptake. A series of potential suicide substrates were synthesized which, following cleavage by the enzyme, would attack the putative nucleophile in the active site. One of these, 3-benzyl-6-chloropyrone (3BCP), inhibited both synthesis and hydrolysis of /sup 14/C-cholesteryl oleate with an I/sub 50/ of approximately 150 ..mu..M. The inactivation was time-dependent and characteristic of a suicide mechanism. The ..cap alpha.. pyronemore » structure (lactone analog) is cleaved by a serine-hydroxyl in the active site. This generates an enoyl chloride which inactivates the imidazole believed to play a part in the catalytic function of the enzyme. Inhibition by 3BCP is selective for cholesterol esterase. The activity of pancreatic lipase as not affected by concentrations up to 1 mM.« less

Diagnosis and treatment of high density lipoprotein deficiency.

PubMed

Schaefer, Ernst J; Anthanont, Pimjai; Diffenderfer, Margaret R; Polisecki, Eliana; Asztalos, Bela F

Low serum high density lipoprotein cholesterol level (HDL-C) <40 mg/dL in men and <50 mg/dL in women is a significant independent risk factor for cardiovascular disease (CVD), and is often observed in patients with hypertriglyceridemia, obesity, insulin resistance, and diabetes. Patients with marked deficiency of HDL-C (<20 mg/dL) in the absence of secondary causes are much less common (<1% of the population). These patients may have homozygous, compound heterozygous, or heterozygous defects involving the apolipoprotein (APO)AI, ABCA1, or lecithin:cholesterol acyl transferase genes, associated with apo A-I deficiency, apoA-I variants, Tangier disease , familial lecithin:cholesteryl ester acyltransferase deficiency, and fish eye disease. There is marked variability in laboratory and clinical presentation, and DNA analysis is necessary for diagnosis. These patients can develop premature CVD, neuropathy, kidney failure, neuropathy, hepatosplenomegaly and anemia. Treatment should be directed at optimizing all non-HDL risk factors. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Molecular target of decursins in the inhibition of lipid droplet accumulation in macrophages.

PubMed

Ohshiro, Taichi; Namatame, Ichiji; Lee, Eun Woo; Kawagishi, Hirokazu; Tomoda, Hiroshi

2006-05-01

During screening for inhibitors of lipid droplet accumulation in mouse peritoneal macrophages, two coumarins identified as decursin and decursinol angelate were isolated from the roots of Angelicae gigantis. The cellular molecular target of these inhibitors in macrophages was studied. Decursin and decursinol angelate inhibited cholesteryl ester (CE) synthesis with IC50 values of 9.7 and 10.1 microM, respectively, whereas they enhanced triacylglycerol (TG) synthesis. Lysosomal metabolism of cholesterol to CE was inhibited by the compounds, indicating that the site of inhibition is one of the steps between the exiting of cholesterol from the lysosomes and CE synthesis in the endoplasmic reticulum. Therefore, acyl-CoA:cholesterol acyltransferase (ACAT) activity in the microsomal fractions prepared from mouse macrophages was studied, and the results showed inhibition of this activity by decursin and decursinol angelate with IC50 values of 43 and 22 microM, respectively. Thus, it was concluded that the compounds inhibit macrophage ACAT activity to decrease CE synthesis, leading to a reduction of lipid droplets in macrophages.

Drugs targeting high-density lipoprotein cholesterol for coronary artery disease management.

PubMed

Katz, Pamela M; Leiter, Lawrence A

2012-01-01

Many patients remain at high risk for future cardiovascular events despite levels of low-density lipoprotein cholesterol (LDL-C) at, or below, target while taking statin therapy. Much effort is therefore being focused on strategies to reduce this residual risk. High-density lipoprotein cholesterol (HDL-C) is a strong, independent, inverse predictor of coronary heart disease risk and is therefore an attractive therapeutic target. Currently available agents that raise HDL-C have only modest effects and there is limited evidence of additional cardiovascular risk reduction on top of background statin therapy associated with their use. It was hoped that the use of cholesteryl ester transfer protein (CETP) inhibitors would provide additional benefit, but the results of clinical outcome studies to date have been disappointing. The results of ongoing trials with other CETP inhibitors that raise HDL-C to a greater degree and also lower LDL-C, as well as with other emerging therapies are awaited. Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Properties of the Products Formed by the Activity of Serum Opacity Factor against Human Plasma High Density Lipoproteins

PubMed Central

Pownall, Henry J.; Courtney, Harry S.; Gillard, Baiba K.; Massey, John B.

2010-01-01

Serum opacity factor from Streptococcus pyogenes transfers the cholesteryl esters (CE) of ~100,000 plasma high density lipoprotein particles (HDL) to a CE-rich microemulsion (CERM) while forming neo HDL, a cholesterol-poor HDL-like particle. HDL, neo HDL, and CERM are distinct. Neo HDL is lower in free cholesterol and has lower surface and total microviscosities than HDL; the surface polarity of neo HDL and HDL are similar. CERM is much larger than HDL and richer in cholesterol and CE. Although the surface microviscosity of HDL is higher than that of CERM, they have similar total microviscosities because cholesterol partitions into the neutral lipid core. Because of its unique surface properties apo E preferentially associates with the CERM. In contrast, the composition and properties of neo HDL make it a potential acceptor of cellular cholesterol and its esterification. Thus, neo HDL and CERM are possible vehicles for improving cholesterol transport to the liver. PMID:18838065

Novel technique for generating macrophage foam cells for in vitro reverse cholesterol transport studies[S

PubMed Central

Sengupta, Bhaswati; Narasimhulu, Chandrakala Aluganti; Parthasarathy, Sampath

2013-01-01

Generation of foam cells, an essential step for reverse cholesterol transport studies, uses the technique of receptor-dependent macrophage loading with radiolabeled acetylated LDL. In this study, we used the ability of a biologically relevant detergent molecule, lysophosphatidylcholine (lyso-PtdCho), to form mixed micelles with cholesterol or cholesteryl ester (CE) to generate macrophage foam cells. Fluorescent or radiolabeled cholesterol/lyso-PtdCho mixed micelles were prepared and incubated with RAW 264.7 or mouse peritoneal macrophages. Results showed that such micelles were quite stable at 4°C and retained the solubilized cholesterol during one month of storage. Macrophages incubated with cholesterol or CE (unlabeled, fluorescently labeled, or radiolabeled)/lyso-PtdCho mixed micelles accumulated CE as documented by microscopy, lipid staining, labeled oleate incorporation, and by TLC. Such foam cells unloaded cholesterol when incubated with HDL but not with oxidized HDL. We propose that stable cholesterol or CE/lyso-PtdCho micelles would offer advantages over existing methods. PMID:24115226

Lipidomic analysis of glycerolipid and cholesteryl ester autooxidation products.

PubMed

Kuksis, Arnis; Suomela, Jukka-Pekka; Tarvainen, Marko; Kallio, Heikki

2009-06-01

Thin-layer chromatography (TLC), gas chromatography (GC), and liquid chromatography (LC) in combination with mass spectrometry (MS) have been adopted for the isolation and identification of oxolipids and for determining their functionality. TLC provides a rapid separation and access to most oxolipids as intact molecules and has recently been effectively interfaced with time-of-flight (TOF) MS (TOF-MS). GC with flame ionization (FI) (GC/FI) and electron impact (EI) MS (GC/EI-MS) has been extensively utilized in the analysis of isoprostanes and other low-molecular-weight oxolipids, although these methods require derivatization of the analytes. In contrast, LC with ultraviolet (UV) absorption (LC/UV) or evaporate light scattering detection (ELSD) (LC/ELSD) as well as electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) MS (LC/ESI-MS) or LC/APCI-MS has proven to be well suited for the analysis of intact oxolipids and their conjugates without or with minimal derivatization. Nevertheless, kit-based colorimetric and fluorescent procedures continue to serve as sensitive indicators of the presence of hydroperoxides and aldehydes.

Improving the Organoleptic Properties of a Craft Mezcal Beverage by Increasing Fatty Acid Ethyl Ester Contents through ATF1 Expression in an Engineered Kluyveromyces marxianus UMPe-1 Yeast.

PubMed

Campos-García, Jesús; Vargas, Alejandra; Farías-Rosales, Lorena; Miranda, Ana L; Meza-Carmen, Víctor; Díaz-Pérez, Alma L

2018-05-02

Mezcal, a traditional beverage that originated in Mexico, is produced from species of the Agavaceae family. The esters associated with the yeasts utilized during fermentation are important for improving the organoleptic properties of the beverage. We improved the ester contents in a mezcal beverage by using the yeast Kluyveromyces marxianus, which was engineered with the ATF1 gene. ATF1 expression in the recombinant yeast significantly increased compared with that in the parental yeast, but its fermentative parameters were unchanged. Volatile-organic-compound-content analysis showed that esters had significantly increased in the mezcal produced with the engineered yeast. In a sensory-panel test, 48% of the panelists preferred the mezcal produced from the engineered yeast, 30% preferred the mezcal produced from the wild type, and 15 and 7% preferred the two mezcal types produced following the routine procedure. Correlation analysis showed that the fruitiness/sweetness description of the mezcal produced using the ATF1-engineered K. marxianus yeast correlated with the content of the esters, whose presence improved the organoleptic properties of the craft mezcal beverage.

Experimental diet-induced atherosclerosis in Quaker parrots (Myiopsitta monachus).

PubMed

Beaufrère, H; Nevarez, J G; Wakamatsu, N; Clubb, S; Cray, C; Tully, T N

2013-11-01

Spontaneous atherosclerosis is common in psittaciformes, and clinical signs associated with flow-limiting stenosis are encountered in pet birds. Nevertheless, a psittacine model of atherosclerosis has not been developed for research investigations. Sixteen captive-bred Quaker parrots (Myiopsitta monachus) were used in this study. While 4 control birds were fed a maintenance diet, 12 other birds were fed an atherogenic diet composed of 1% cholesterol controlling for a calorie-to-protein ratio for periods ranging from 2 to 8 months. The birds were euthanized at the end of their respective food trial period. Histopathology, transmission electron microscopy, and cholesterol measurement were performed on the ascending aorta and brachiocephalic and pulmonary arteries. Plasma lipoproteins, cholesterol, and triglycerides were also measured on a monthly basis. Significant atherosclerotic lesions were induced within 2 months and advanced atherosclerotic lesions within 4 to 6 months. The advanced lesions were histologically similar to naturally occurring lesions identified in the same parrot species with a lipid core and a fibrous cap. Ultrastructurally, there were extracellular lipid, foam cell, and endothelial changes. Arterial cholesterol content increased linearly over time. Plasma cholesterol and low-density lipoprotein (LDL) significantly increased over time by an average of 5- and 15-fold, respectively, with a shift from high-density lipoprotein to LDL as the main plasma lipoprotein. Quaker parrots also exhibited high plasma cholesteryl ester transfer protein activity that increased, although not significantly, over time. This experiment demonstrates that in Quaker parrots fed 1% cholesterol, advanced atherosclerosis can be induced relatively quickly, and lesions resemble those found in other avian models and humans.

Fucoidan cytotoxicity against human breast cancer T47D cell line increases with higher level of sulfate ester group

NASA Astrophysics Data System (ADS)

Saepudin, Endang; Alfita Qosthalani, Fildzah; Sinurat, Ellya

2018-01-01

The anticancer activity of different sulfate ester group content in different molecular weight was examined. The anticancer activity was achieved in vitro on human breast cancer T47D cell line. Fucoidan with lower molecular weight (5.79 kDa) tends to have lower sulfate ester group content (8.69%) and resulted in higher IC50 value (184.22 μg/mL). While fucoidan with higher molecular weight (785.12 kDa) tends to have higher sulfate level (18.63%) and achieved lower IC50 value (75.69 μg/mL). The result showed that in order to maintain fucoidan cytotoxic activity against human breast cancer T47D cell line, the sulfate content should be remain high. Keywords: fucoidan, sulfate ester group, human breast cancer

The Comparison of Hydrotreated Vegetable Oils With Respect to Petroleum Derived Fuels and the Effects of Transient Plasma Ignition in a Compression-Ignition Engine

DTIC Science & Technology

2012-09-01

Content per Combustion J FAME Fatty Acid Methyl Ester FMEP Friction Mean Effective Pressure PSI or Bar FT Fischer-Tropsch h Heat...recently, algae-derived oils. Biodiesel has gained popularity in North America over the past decade, but the ester content of Fatty Acid Methyl ... Ester ( FAME ) fuel creates both cold weather and water- based operational issues. The Fischer-Tropsch (FT) process produces liquid fuels from “syngas,” a

Mechanism of action of a peroxisome proliferator-activated receptor (PPAR)-delta agonist on lipoprotein metabolism in dyslipidemic subjects with central obesity.

PubMed

Ooi, Esther M M; Watts, Gerald F; Sprecher, Dennis L; Chan, Dick C; Barrett, P Hugh R

2011-10-01

Dyslipidemia increases the risk of cardiovascular disease in obesity. Peroxisome proliferator-activated receptor (PPAR)-δ agonists decrease plasma triglycerides and increase high-density lipoprotein (HDL)-cholesterol in humans. The aim of the study was to examine the effect of GW501516, a PPAR-δ agonist, on lipoprotein metabolism. Design, Setting, and Intervention: We conducted a randomized, double-blind, crossover trial of 6-wk intervention periods with placebo or GW501516 (2.5 mg/d), with 2-wk placebo washout between treatment periods. We recruited 13 dyslipidemic men with central obesity from the general community. We measured the kinetics of very low-density lipoprotein (VLDL)-, intermediate-density lipoprotein-, and low-density lipoprotein (LDL)-apolipoprotein (apo) B-100, plasma apoC-III, and high-density lipoprotein (HDL) particles (LpA-I and LpA-I:A-II). GW501516 decreased plasma triglycerides, fatty acid, apoB-100, and apoB-48 concentrations. GW501516 decreased the concentrations of VLDL-apoB by increasing its fractional catabolism and of apoC-III by decreasing its production rate (P < 0.05). GW501516 reduced VLDL-to-LDL conversion and LDL-apoB production. GW501516 increased HDL-cholesterol, apoA-II, and LpA-I:A-II concentrations by increasing apoA-II and LpA-I:A-II production (P < 0.05). GW501516 decreased cholesteryl ester transfer protein activity, and this was paralleled by falls in the triglyceride content of VLDL, LDL, and HDL and the cholesterol content of VLDL and LDL. GW501516 increased the hepatic removal of VLDL particles, which might have resulted from decreased apoC-III concentration. GW501516 increased apoA-II production, resulting in an increased concentration of LpA-I:A-II particles. This study elucidates the mechanism of action of this PPAR-δ agonist on lipoprotein metabolism and supports its potential use in treating dyslipidemia in obesity.

Nonessential fatty acids in formula fat blends influence essential fatty acid metabolism and composition in plasma and organ lipid classes in piglets.

PubMed

Wall, K M; Diersen-Schade, D; Innis, S M

1992-12-01

The n-6 and n-3 fatty acid status of developing organs is the cumulative result of the diet lipid composition and many complex events of lipid metabolism. Little information is available, however, on the potential effects of the saturated fatty acid chain length (8:0-16:0) or oleic acid (18:1) content of the diet on the subsequent metabolism of the essential fatty acids 18:2n-6 and 18:3n-3 and their elongated/desaturated products. The effects of feeding piglets formulas with fat blends containing either coconut oil (12:0 + 14:0) or medium chain triglycerides (MCT, 8:0 + 10:0) but similar levels of 18:1, 18:2n-6 and 18:3n-3, or MCT with high or low 18:1 but constant 18:2n-6 and 18:3n-3 on the fatty acid composition of plasma, liver and kidney triglycerides, phospholipids and cholesteryl esters, and of brain total lipid, were studied. Diet-induced changes in the fatty acid composition of lipid classes were generally similar for plasma, liver and kidney. Dietary 18:1 content was reflected in tissue lipids and was inversely associated with levels of 18:2n-6. Lower percentage of 18:2n-6, however, was not associated with lower levels of its elongated/desaturated product 20:4n-6 but was associated with higher levels of 22:6n-3. Feeding coconut oil vs. MCT resulted in lower 18:1 levels in all lipids, and higher percentages of 20:4n-6 in tissue phospholipid. Increasing the dietary n-6/n-3 ratio from 5 to 8 significantly increased tissue percentage of 18:2n-6 and decreased phospholipid 22:6n-3.(ABSTRACT TRUNCATED AT 250 WORDS)

Diet and waist-to-hip ratio: important predictors of lipoprotein levels in sedentary and active young men with no evidence of cardiovascular disease.

PubMed

Mansfield, E; McPherson, R; Koski, K G

1999-11-01

Healthy, young men were studied to determine the relationship of energy and nutrient intake and physical activity to concentrations of plasma lipoprotein and cholesteryl ester transfer protein. A cross-sectional study compared active and sedentary male subjects (17 to 35 years old) with no personal or family history of coronary heart disease. Participants kept 20-day food and activity journals. Individual intakes of energy, protein, carbohydrate, fat, saturated fat, monounsaturated fatty acids, polyunsaturated fatty acids, dietary fiber, and alcohol were evaluated. Measurements of blood lipids (total cholesterol and triglycerides, high- and low-density lipoprotein cholesterol); apolipoproteins; cholesteryl ester transfer protein; anthropometric variables (body mass index, waist-to-hip ratio, percentage of body fat); and aerobic capacity were taken during fall and spring data collection periods. SUBJECT SELECTION: Subjects were selected on the basis of normal blood lipid levels, absence of underlying disease, and willingness to comply with their current level of physical activity for the duration of the study. Minimal sample size for statistical power was 12 men per group: 12 of 15 subjects who exercised and 13 of 15 subjects who were sedentary completed all phases of the study. Statistical analyses consisted of 2-way analysis of variance (activity level and season). Pearson product moment correlations and multiple regression analyses were conducted to assess whether energy and nutrient intakes, physical activity status, and/or anthropometric variables predicted plasma concentrations of lipids and apolipoproteins. Lower waist-to-hip ratio, and not specifically activity level, was associated with higher levels of high-density lipoprotein cholesterol (HDL-C) and lower levels of low-density lipoprotein cholesterol (LDL-C). Dietary intake of saturated and monounsaturated fats and alcohol predicted changes in some apolipoprotein and lipoprotein levels. Use of waist-to-hip ratio in the primary prevention of coronary heart disease is a simple and cost-effective measure to predict development of abnormal lipoprotein profiles in young men. Specific dietary recommendations include adoption of a heart-healthy diet with emphasis on monounsaturated fatty acids (10% to 12% of energy or one third of total fat intake) and the suggestion that small amounts of alcohol (< 3 drinks per week) may, indeed, be beneficial. Because alcohol and waist-to-hip ratio were both important predictors of LDL-C level, even in active young men, the consumption of low levels of alcohol may be beneficial only if waist-to-hip ratio is maintained within the healthful range by achieving an appropriate balance of physical activity and macronutrient intake.

Effects of Blending Alcohols with Poultry Fat Methyl Esters on Cold Flow Properties

USDA-ARS?s Scientific Manuscript database

The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol in a linear fashion with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols t...

Do lipids retard the evaporation of the tear fluid?

PubMed

Rantamäki, Antti H; Javanainen, Matti; Vattulainen, Ilpo; Holopainen, Juha M

2012-09-21

We examined in vitro the potential evaporation-retarding effect of the tear film lipid layer (TFLL). The artificial TFLL compositions used here were based on the present knowledge of TFLL composition. A custom-built system was developed to measure evaporation rates at 35°C. Lipids were applied to an air-water interface, and the evaporation rate through the lipid layer was defined as water loss from the interface. A thick layer of olive oil and a monolayer of long-chain alcohol were used as controls. The artificial TFLLs were composed of 1 to 4 lipid species: polar phosphatidylcholine (PC), nonpolar cholesteryl ester, triglycerides, and wax ester (WE). Brewster angle microscopy (BAM) and interfacial shear rheometry (ISR) were used to assess the lateral structure and shear stress response of the lipid layers, respectively. Olive oil and long-chain alcohol decreased evaporation by 54% and 45%, respectively. The PC monolayer and the four-component mixtures did not retard evaporation. WE was the most important evaporation-retardant TFLL lipid (∼20% decrease). In PC/WE mixtures, an ∼90% proportion of WE was required for evaporation retardation. Based on BAM and ISR, WE resulted in more condensed layers than the non-retardant layers. Highly condensed, solid-like lipid layers, such as those containing high proportions of WEs, are evaporation-retardant. In multi-component lipid layers, the evaporation-retardant interactions between carbon chains decrease and, therefore, these lipid layers do not retard evaporation.

Supercooled smectic nanoparticles: a potential novel carrier system for poorly water soluble drugs.

PubMed

Kuntsche, J; Westesen, K; Drechsler, M; Koch, M H J; Bunjes, H

2004-10-01

The possibility of preparing nanoparticles in the supercooled thermotropic liquid crystalline state from cholesterol esters with saturated acyl chains as well as the incorporation of model drugs into the dispersions was investigated using cholesteryl myristate (CM) as a model cholesterol ester. Nanoparticles were prepared by high-pressure melt homogenization or solvent evaporation using phospholipids, phospholipid/ bile salt, or polyvinyl alcohol as emulsifiers. The physicochemical state and phase behavior of the particles was characterized by particle size measurements (photon correlation spectroscopy, laser diffraction with polarization intensity differential scattering), differential scanning calorimetry, X-ray diffraction, and electron and polarizing light microscopy. The viscosity of the isotropic and liquid crystalline phases of CM in the bulk was investigated in dependence on temperature and shear rate by rotational viscometry. CM nanoparticies can be obtained in the smectic phase and retained in this state for at least 12 months when stored at 230C in optimized systems. The recrystallization tendency of CM in the dispersions strongly depends on the stabilizer system and the particle size. Stable drug-loaded smectic nanoparticles were obtained after incorporation of 10% (related to CM) ibuprofen, miconazole, etomidate, and 1% progesterone. Due to their liquid crystalline state, colloidal smectic nanoparticles offer interesting possibilities as carrier system for lipophilic drugs. CM nanoparticles are suitable model systems for studying the crystallization behavior and investigating the influence of various parameters for the development of smectic nanoparticles resistant against recrystallization upon storage.

Preparation of polyol esters based on vegetable and animal fats.

PubMed

Gryglewicz, S; Piechocki, W; Gryglewicz, G

2003-03-01

The possibility of using some natural fats: rapeseed oil, olive oil and lard, as starting material for the preparation of neopentyl glycol (NPG) and trimethylol propane (TMP) esters is reported. The syntheses of final products were performed by alcoholysis of fatty acid methyl esters, obtained from natural fats studied, with the appropriate polyhydric alcohol using calcium methoxide as a catalyst. The basic physicochemical properties of the NPG and TMP esters synthesized were the following: viscosity at 40 degrees C in the range of 13.5-37.6 cSt, pour point between -10.5 and -17.5 degrees C and very high viscosity indices, higher than 200. Generally, the esters of neopentyl alcohols were characterized by higher stability in thermo-oxidative conditions in comparison to native triglycerides. Due to the low content of polyunsaturated acids, the olive oil based esters showed the highest thermo-oxidative resistance. Also, methyl esters of fatty acids of lard would constitute a good raw material for the synthesis of lubricating oils, provided that their saturated acids content was lowered. This permits synthesis of NPG and TMP esters with a lower pour point (below -10 degrees C) than natural lard (+33 degrees C).

Ursolic acid and its esters: occurrence in cranberries and other Vaccinium fruit and effects on matrix metalloproteinase activity in DU145 prostate tumor cells.

PubMed

Kondo, Miwako; MacKinnon, Shawna L; Craft, Cheryl C; Matchett, Michael D; Hurta, Robert A R; Neto, Catherine C

2011-03-30

Ursolic acid and its cis- and trans-3-O-p-hydroxycinnamoyl esters have been identified as constituents of American cranberries (Vaccinium macrocarpon), which inhibit tumor cell proliferation. Since the compounds may contribute to berry anticancer properties, their content in cranberries, selected cranberry products, and three other Vaccinium species (V. oxycoccus, V. vitis-idaea and V. angustifolium) was determined by liquid chromatography-mass spectroscopy. The ability of these compounds to inhibit growth in a panel of tumor cell lines and inhibit matrix metalloproteinase (MMP) activity associated with tumor invasion and metastasis was determined in DU145 prostate tumor cells. The highest content of ursolic acid and esters was found in V. macrocarpon berries (0.460-1.090 g ursolic acid and 0.040-0.160 g each ester kg(-1) fresh weight). V. vitis-idaea and V. angustifolium contained ursolic acid (0.230-0.260 g kg(-1) ), but the esters were not detected. V. oxycoccus was lowest (0.129 g ursolic acid and esters per kg). Ursolic acid content was highest in cranberry products prepared from whole fruit. Ursolic acid and its esters inhibited tumor cell growth at micromolar concentrations, and inhibited MMP-2 and MMP-9 activity at concentrations below those previously reported for cranberry polyphenolics. Cranberries (V. macrocarpon) were the best source of ursolic acid and its esters among the fruit and products tested. These compounds may limit prostate carcinogenesis through matrix metalloproteinase inhibition. Copyright © 2011 Society of Chemical Industry.

Evaluation of Antiatherogenic Properties of Ezetimibe Using 3H-Labeled Low-Density-Lipoprotein Cholesterol and 99mTc-cAbVCAM1-5 SPECT in ApoE-/- Mice Fed the Paigen Diet.

PubMed

Dumas, Laurent S; Briand, François; Clerc, Romain; Brousseau, Emmanuel; Montemagno, Christopher; Ahmadi, Mitra; Bacot, Sandrine; Soubies, Audrey; Perret, Pascale; Riou, Laurent M; Devoogdt, Nick; Lahoutte, Tony; Barone-Rochette, Gilles; Fagret, Daniel; Ghezzi, Catherine; Sulpice, Thierry; Broisat, Alexis

2017-07-01

The addition of ezetimibe, an intestinal cholesterol absorption inhibitor, to statin therapy has recently shown clinical benefits in the Improved Reduction of Outcomes: Vytorin Efficacy International Trial by reducing low-density-lipoprotein (LDL) cholesterol levels more than statin therapy alone. Here, we investigated the mechanisms by which inhibition of intestinal cholesterol absorption might contribute to the clinically observed reduction in cardiovascular events by evaluating its effect on inflammatory plaque development in apolipoprotein E -/- mice. Methods: Apolipoprotein E -/- mice were fed the Paigen diet (1.25% cholesterol, 0.5% cholic acid, and 15% fat) without or with ezetimibe (7 mg/kg/d) for 6 wk. In a first set of mice ( n = 15), we intravenously injected 3 H-cholesteryl oleate-labeled human LDL to test whether ezetimibe promotes LDL-derived cholesterol fecal excretion. In a second set ( n = 20), we used the imaging agent 99m Tc-cAbVCAM1-5 to evaluate expression of an inflammatory marker, vascular cell adhesion molecule 1 (VCAM-1), in atherosclerotic plaques. In a third set ( n = 21), we compared VCAM-1 expression with 99m Tc-cAbVCAM1-5 uptake in various tissues. Results: Mice treated with ezetimibe showed a 173% higher LDL-cholesteryl ester plasma disappearance rate ( P < 0.001 vs. control) after 3 H-cholesteryl oleate-labeled LDL injection. At 96 h after injection, the hepatic fraction of 3 H-tracer was 61% lower in mice treated with ezetimibe ( P < 0.001). Meanwhile, LDL-derived 3 H-cholesterol excretion in the feces was 107% higher ( P < 0.001). The antiatherogenic effect of ezetimibe monitored by 99m Tc-cAbVCAM1-5 SPECT showed a 49% reduction in aortic tracer uptake (percentage injected dose per cubic centimeter, 0.95 ± 0.04 vs. 1.87 ± 0.11; P < 0.01). In addition to hypercholesterolemia, the proinflammatory Paigen diet significantly increased VCAM-1 expression with respect to the control group in various tissues, including the aorta, and this expression correlated strongly with 99m Tc-cAbVCAM1-5 uptake ( r = 0.75; P < 0.05). Conclusion: Inhibition of intestinal cholesterol absorption with ezetimibe promotes antiatherosclerotic effects through increased LDL cholesterol catabolism and LDL-derived cholesterol fecal excretion and reduces inflamed atherosclerotic plaques. These mechanisms may contribute to the benefits of adding ezetimibe to a statin therapy. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Analysis of acrylamide, 3-monochloropropane-1,2-diol, its esters and glycidyl esters in carbohydrate-rich products available on the Polish market

PubMed

Sadowska-Rociek, Anna; Surma, Magdalena; Cieślik, Ewa

2018-01-01

Carbohydrate-rich foods, such as breakfast products, snacks and biscuits because of its nutritional or sensory qualities are an inherent part of human diet. However, their production might contribute to the formation of acrylamide, 3-monochloropropane-1,2-diol (3-MCPD) and its esters and glycidyl esters. The aim of this work was to assess the levels of acrylamide, free and bound 3-MCPD and glycidyl esters in selected carbohydrate-rich, thermal processed products, present on the market in Poland in 2016-2017. The survey involved 60 samples of snacks, breakfast products and biscuits. Acrylamide and free 3-MCPD was determined using modified QuEChERS approach. Analysis of 3-MCPD and glycidyl esters was based on the acid-catalysed method of sample preparation, derivatisation with PBA and GC-MS analysis. Free 3-MCPD contents were within the values of 9.3-63.3 μg kg-1, with the highest mean content for muesli (33.3 μg kg-1), and the lowest for baby biscuits (11.7 μg kg-1). The levels of bound 3-MCPD were higher (from 9.3 μg kg-1 to 1500 μg kg-1). The highest average content was observed for sugar free biscuits (599 μg kg-1), whereas the lowest for breakfast cereals (50.2 μg kg-1). Glycidyl esters were detected only in four samples with the highest content at the level of 28.8 μg kg-1. The acrylamide levels varied from 195 to 1352 μg kg-1, with the highest content for organic biscuit samples (913 μg kg-1), and the lowest for muesli (348 μg kg-1). Regular consumption of popular snacks such as potato chips, crackers and biscuits may result in risk to human health as the effect of high content of acrylamide or 3-MCPD. Due to a high level of these contaminants detected in some type of breakfast products, and products targeted for children, its consumption should be restricted, especially in younger population groups.

Cholesteryl oleate-loaded cationic solid lipid nanoparticles as carriers for efficient gene-silencing therapy

PubMed Central

Suñé-Pou, Marc; Prieto-Sánchez, Silvia; El Yousfi, Younes; Boyero-Corral, Sofía; Nardi-Ricart, Anna; Nofrerias-Roig, Isaac; Pérez-Lozano, Pilar; García-Montoya, Encarna; Miñarro-Carmona, Montserrat; Ticó, Josep Ramón; Suñé-Negre, Josep Mª; Hernández-Munain, Cristina; Suñé, Carlos

2018-01-01

Background Cationic solid lipid nanoparticles (SLNs) have been given considerable attention for therapeutic nucleic acid delivery owing to their advantages over viral and other nanoparticle delivery systems. However, poor delivery efficiency and complex formulations hinder the clinical translation of SLNs. Aim The aim of this study was to formulate and characterize SLNs incorporating the cholesterol derivative cholesteryl oleate to produce SLN–nucleic acid complexes with reduced cytotoxicity and more efficient cellular uptake. Methods Five cholesteryl oleate-containing formulations were prepared. Laser diffraction and laser Doppler microelectrophoresis were used to evaluate particle size and zeta potential, respectively. Nanoparticle morphology was analyzed using electron microscopy. Cytotoxicity and cellular uptake of lipoplexes were evaluated using flow cytometry and fluorescence microscopy. The gene inhibition capacity of the lipoplexes was assessed using siRNAs to block constitutive luciferase expression. Results We obtained nanoparticles with a mean diameter of approximately 150–200 nm in size and zeta potential values of 25–40 mV. SLN formulations with intermediate concentrations of cholesteryl oleate exhibited good stability and spherical structures with no aggregation. No cell toxicity of any reference SLN was observed. Finally, cellular uptake experiments with DNA-and RNA-SLNs were performed to select one reference with superior transient transfection efficiency that significantly decreased gene activity upon siRNA complexation. Conclusion The results indicate that cholesteryl oleate-loaded SLNs are a safe and effective platform for nonviral nucleic acid delivery. PMID:29881274

Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup.

PubMed

Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

2018-01-01

Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES). Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC) and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

PubMed Central

Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

2018-01-01

Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES). Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC) and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness. PMID:29487847

Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

NASA Astrophysics Data System (ADS)

Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

2018-02-01

Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents. Since it has been shown that it is possible to synthesize sugar esters in these deep eutectic solvents, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography and compared to a sugar ester which was synthesized in a conventional deep eutectic solvent. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

PubMed

Eleutério Dos Santos, Caroline Mongruel; Pietrowski, Giovana de Arruda Moura; Braga, Cíntia Maia; Rossi, Márcio José; Ninow, Jorge; Machado Dos Santos, Tâmisa Pires; Wosiacki, Gilvan; Jorge, Regina Maria Matos; Nogueira, Alessandro

2015-06-01

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. © 2015 Institute of Food Technologists®

Rapid screening of fatty acid alkyl esters in olive oils by time domain reflectometry.

PubMed

Berardinelli, Annachiara; Ragni, Luigi; Bendini, Alessandra; Valli, Enrico; Conte, Lanfranco; Guarnieri, Adriano; Toschi, Tullia Gallina

2013-11-20

The main aim of the present research is to assess the possibility of quickly screening fatty acid alkyl esters (FAAE) in olive oils using time domain reflectometry (TDR) and partial least-squares (PLS) multivariate statistical analysis. Eighteen virgin olive oil samples with fatty acid alkyl ester contents and fatty acid ethyl ester/methyl ester ratios (FAEE/FAME) ranging from 3 to 100 mg kg(-1) and from 0.3 to 2.6, respectively, were submitted to tests with time domain resolution of 1 ps. The results obtained in test set validation demonstrated that this new and fast analytical approach is able to predict FAME, FAEE, and FAME + FAEE contents with R(2) values of 0.905, 0.923, and 0.927, respectively. Further measurements on mixtures between olive oil and FAAE standards confirmed that the prediction is based on a direct influence of fatty acid alkyl esters on the TDR signal. The suggested technique appeared potentially suitable for monitoring one of the most important quality attribute of the olive oil in the extraction process.

Volatile profiles of members of the USDA Geneva Malus Core Collection: utility in evaluation of a hypothesized biosynthetic pathway for esters derived from 2-methylbutanoate and 2-methylbutan-1-ol.

PubMed

Sugimoto, Nobuko; Forsline, Philip; Beaudry, Randolph

2015-02-25

The volatile ester and alcohol profiles of ripening apple fruit from 184 germplasm lines in the USDA Malus Germplasm Repository at the New York Agricultural Experiment Station in Geneva, NY, USA, were evaluated. Cluster analysis suggested biochemical relationships exist between several ester classes. A strong linkage was revealed between 2-methylbutanoate, propanoate, and butanoate esters, suggesting the influence of the recently proposed "citramalic acid pathway" in apple fruit. Those lines with a high content of esters formed from 2-methylbutan-1-ol and 2-methylbutanoate (2MB) relative to straight-chain (SC) esters (high 2MB/SC ratio) exhibited a marked increase in isoleucine and citramalic acid during ripening, but those lines with a low content did not. Thus, the data were consistent with the existence of the hypothesized citramalic acid pathway and suggest that the Geneva Malus Germplasm Repository, appropriately used, could be helpful in expanding our understanding of mechanisms for fruit volatile synthesis and other aspects of secondary metabolism.

LAL (Lysosomal Acid Lipase) Promotes Reverse Cholesterol Transport In Vitro and In Vivo.

PubMed

Bowden, Kristin L; Dubland, Joshua A; Chan, Teddy; Xu, You-Hai; Grabowski, Gregory A; Du, Hong; Francis, Gordon A

2018-05-01

To explore the role of LAL (lysosomal acid lipase) in macrophage cholesterol efflux and whole-body reverse cholesterol transport. Immortalized peritoneal macrophages from lal -/- mice showed reduced expression of ABCA1 (ATP-binding cassette transporter A1) and ABCG1 (ATP-binding cassette transporter G1), reduced production of the regulatory oxysterol 27-hydroxycholesterol, and impaired suppression of cholesterol synthesis on exposure to acetylated low-density lipoprotein when compared with lal +/+ macrophages. LAL-deficient mice also showed reduced hepatic ABCG5 (ATP-binding cassette transporter G5) and ABCG8 (ATP-binding cassette transporter G8) expression compared with lal +/+ mice. LAL-deficient macrophages loaded with [ 3 H]-cholesteryl oleate-labeled acetylated low-density lipoprotein showed impaired efflux of released [ 3 H]-cholesterol to apoA-I (apolipoprotein A-I), with normalization of [ 3 H]-cholesteryl ester levels and partial correction of ABCA1 expression and cholesterol efflux to apoA-I when treated with exogenous rhLAL (recombinant human LAL protein). LAL-deficient mice injected intraperitoneally with lal -/- macrophages cholesterol loaded and labeled in the same way exhibited only 1.55±0.35% total injected [ 3 H]-cholesterol counts appearing in the feces for 48 h (n=30), compared with 5.38±0.92% in lal +/+ mice injected with labeled lal +/+ macrophages (n=27), P <0.001. To mimic the therapeutic condition of delivery of supplemental LAL in vivo, injection of labeled lal -/- macrophages into lal +/+ mice resulted in a significant increase in reverse cholesterol transport (2.60±0.46% of 3 H-cholesterol counts in feces at 48 hours [n=19]; P <0.001 when compared with injection into lal -/- mice). These results indicate a critical role for LAL in promoting both macrophage and whole-body reverse cholesterol transport and the ability of supplemental LAL to be taken up and correct reverse cholesterol transport in vivo. © 2018 American Heart Association, Inc.

Hepatic Overexpression of Endothelial Lipase Lowers HDL (High-Density Lipoprotein) but Maintains Reverse Cholesterol Transport in Mice: Role of SR-BI (Scavenger Receptor Class B Type I)/ABCA1 (ATP-Binding Cassette Transporter A1)-Dependent Pathways.

PubMed

Takiguchi, Shunichi; Ayaori, Makoto; Yakushiji, Emi; Nishida, Takafumi; Nakaya, Kazuhiro; Sasaki, Makoto; Iizuka, Maki; Uto-Kondo, Harumi; Terao, Yoshio; Yogo, Makiko; Komatsu, Tomohiro; Ogura, Masatsune; Ikewaki, Katsunori

2018-05-10

Reverse cholesterol transport (RCT) is a major mechanism by which HDL (high-density lipoprotein) protects against atherosclerosis. Endothelial lipase (EL) reportedly reduces HDL levels, which, in theory, would increase atherosclerosis. However, it remains unclear whether EL affects RCT in vivo. Adenoviral vectors expressing EL or luciferase were intravenously injected into mice, and a macrophage RCT assay was performed. As expected, hepatic EL overexpression markedly reduced HDL levels. In parallel, plasma 3 H-cholesterol counts from the EL-expressing mice decreased by 85% compared with control. Surprisingly, there was no difference in fecal 3 H-cholesterol excretion between the groups. Kinetic studies revealed increased catabolism/hepatic uptake of 3 HDL-cholesteryl ether, resulting in no change in fecal HDL-cholesteryl ester excretion in the mice. To explore underlying mechanisms for the preservation of RCT despite low HDL levels in the EL-expressing mice, we investigated the effects of hepatic SR-BI (scavenger receptor class B type I) knockdown. RCT assay revealed that knockdown of SR-BI alone reduced fecal excretion of macrophage-derived 3 H-cholesterol. Interestingly, hepatic EL overexpression under SR-BI inhibition further attenuated fecal tracer counts as compared with control. Finally, we observed that EL overexpression enhanced in vivo RCT under pharmacological inhibition of hepatic ABCA1 (ATP-binding cassette transporter A1) by probucol. Hepatic EL expression compensates for reduced macrophage-derived cholesterol efflux to plasma because of low HDL levels by promoting cholesterol excretion to bile/feces via an SR-BI pathway, maintaining overall RCT in vivo. In contrast, EL-modified HDL might negatively regulate RCT via hepatic ABCA1. Despite extreme hypoalphalipoproteinemia, RCT is maintained in EL-expressing mice via SR-BI/ABCA1-dependent pathways. © 2018 American Heart Association, Inc.

Antioxidant protection of LDL by physiological concentrations of 17 beta-estradiol. Requirement for estradiol modification.

PubMed

Shwaery, G T; Vita, J A; Keaney, J F

1997-03-18

Exposure to estrogens reduces the risk for coronary artery disease and associated clinical events; however, the mechanisms responsible for these observations are not clear. Supraphysiological levels of estrogens act as antioxidants in vitro, limiting oxidation of low-density lipoprotein (LDL), an event implicated in atherogenesis. We investigated the conditions under which physiological concentrations of 17 beta-estradiol (E2) inhibit oxidative modification of LDL. Plasma incubated with E2 (0.1 to 100 nmol/L) for 4 hours yielded LDL that demonstrated a dose-related increase in resistance to oxidation by Cu2+ as measured by conjugated diene formation. This effect was dependent on plasma, because incubation of isolated LDL with E2 at these concentrations in buffered saline produced no effect on Cu(2+)-mediated oxidation. Incubation of plasma with E2 had no effect on LDL alpha-tocopherol content or cholesteryl ester hydroperoxide formation during the 4-hour incubation. Plasma incubation with [3H]E2 was associated with dose-dependent association of 3H with LDL. High-performance liquid chromatographic analysis of LDL derived from plasma incubated with [3H]E2 indicated that the majority of the associated species were not detectable as authentic E2 but as nonpolar forms of E2 that were susceptible to base hydrolysis consistent with fatty acid esterification of E2. Plasma-mediated association of E2 and subsequent antioxidant protection was inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), an inhibitor of plasma acyltransferase activity. Exposure of LDL to physiological levels of E2 in a plasma milieu is associated with enhanced resistance to Cu(2+)-mediated oxidation and incorporation of E2 derivatives into LDL. This antioxidant capacity may be another means by which E2 limits coronary artery disease in women.

Glycoxidized HDL, HDL enriched with oxidized phospholipids and HDL from diabetic patients inhibit platelet function

PubMed Central

Lê, Quang Huy; El Alaoui, Meddy; Véricel, Evelyne; Ségrestin, Bérénice; Soulère, Laurent; Guichardant, Michel; Lagarde, Michel; Moulin, Philippe; Calzada, Catherine

2015-01-01

Context High-density lipoproteins (HDL) possess atheroprotective properties including anti-thrombotic and antioxidant effects. Very few studies relate to the functional effects of oxidized HDL on platelets in type 2 diabetes (T2D). Objective The objective of our study was to investigate the effects of in vitro glycoxidized HDL, and HDL from T2D patients on platelet aggregation and arachidonic acid signaling cascade. At the same time, the contents of hydroxylated fatty acids were assessed in HDL. Results Compared to control HDL, in vitro glycoxidized HDL had decreased proportions of linoleic (LA) and arachidonic (AA) acids in phospholipids and cholesteryl esters, and increased concentrations of hydroxy-octadecadienoic acids (9-HODE and 13-HODE) and 15-hydroxy-eicosatetraenoic acid (15-HETE), derived from LA and AA respectively, especially hydroxy derivatives esterified in phospholipids. Glycoxidized HDL dose-dependently decreased collagen-induced platelet aggregation by binding to SR-BI. Glycoxidized HDL prevented collagen-induced increased phosphorylation of platelet p38 MAPK and cytosolic phospholipase A2, as well as intracellular calcium mobilization. HDL enriched with oxidized phospholipids, namely PC(16:0/13-HODE) dose-dependently inhibited platelet aggregation. Increased concentrations of 9-HODE, 13-HODE and 15-HETE in phospholipids (2.1, 2.1 and 2.4-fold increase respectively) were found in HDL from patients with T2D, and these HDL also inhibited platelet aggregation via SR-BI. Conclusions Altogether, our results indicate that in vitro glycoxidized HDL as well as HDL from T2D patients inhibit platelet aggregation, and suggest that oxidized LA-containing phospholipids may contribute to the anti-aggregatory effects of glycoxidized HDL and HDL from T2D patients. PMID:25794249

FA composition of heart and skeletal muscle during embryonic development of the king penguin.

PubMed

Decrock, Frederic; Groscolas, Rene; Speake, Brian K

2002-04-01

Since the yolk lipids of the king penguin (Aptenodytes patagonicus) naturally contain the highest concentrations of DHA and EPA yet reported for the eggs of any avian species, the effects of this (n-3)-rich yolk on the FA profiles of the embryonic heart and skeletal muscle were investigated. The concentrations (mg/g wet tissue) of phospholipid (PL) in the developing heart and leg muscle of the penguin doubled between days 27 and 55 from the beginning of egg incubation (i.e., from the halfway stage of embryonic development to 2 d posthatch), whereas no net increase occurred in pectoral muscle. During this period, the concentration of TAG in heart decreased by half but increased two- and sixfold in leg and pectoral muscle, respectively. The most notable change in cholesteryl ester concentration occurred in pectoral muscle, increasing ninefold between days 27 and 55. Arachidonic acid (ARA) was the major polyunsaturate in PL of the penguin's heart, where it formed about 20% (w/w) of FA at day 55. At the equivalent developmental stage, the heart PL of the chicken contained a 1.3-fold greater proportion of ARA, contained a fifth less DHA, and was almost devoid of EPA, whereas the latter FA was a significant component (7% of FA) of penguin heart PL. Similarly, in PL of leg and pectoral muscle, the chicken displayed about 1.4-fold more ARA, up to 50% less DHA, and far less EPA in comparison with the penguin. Thus, although ARA-rich PL profiles are achieved in the heart and muscle of the penguin embryo, these profiles are significantly affected by the high n-3 content of the yolk.

The influence of acclimation temperature on the lipid composition of the larval lamprey, Petromyzon marinus, depends on tissue and lipid class.

PubMed

Kao, Yung-Hsi; Sheridan, Mark A; Holmes, John A; Youson, John H

2010-11-01

This study was designed to examine the effect of thermal acclimation on the lipid composition of fat depot organs the liver and kidneys of larval sea lamprey, Petromyzon marinus. We found that 21 °C-acclimated larvae possessed lower total lipid amounts in the liver (39% lower) and kidneys (30% lower) than 13 °C-acclimated larvae. Relatively lower lipid contents in the liver and kidneys of 21 °C-acclimated lamprey primarily resulted from a reduction in stored lipid reserve, triacylglycerol, but not the structural lipid, phospholipid. Compared to 21 °C-acclimated larvae, 13 °C-acclimated larvae were found to possess fewer saturated fatty acids (SFAs) and more unsaturated fatty acids (USFAs) in renal triacylglycerol and phospholipid classes, while there were no significant differences in the SFAs and USFAs of hepatic triacylglycerol, phospholipid, cholesteryl ester, fatty acid, and monoacylglycerol classes. Fewer SFAs, found in the kidney triacylglycerol of 13 °C-acclimated lamprey, were due to lower 12:0 and 14:0 fatty acids, but those in the renal phospholipid class were characterized by fewer 14:0, 15:0, and 16:0 fatty acids. More USFAs in renal triacylglycerol, as indicated by a higher unsaturation index, primarily resulted from higher polyunsaturated fatty acids (18:2ω6, 18:3ω3, and 18:4ω3); whereas, in the renal phospholipid class, this was a result of higher monoenes (18:1, 20:1, and 22:1ω9) and ω3 polyunsaturated fatty acids (18:4ω3). These data suggest that the influence of thermal acclimation on the lipid composition of lamprey fat depot organs depends on tissue and lipid class.

Background diet and fat type alters plasma lipoprotein response but not aortic cholesterol accumulation in F1B Golden Syrian hamsters.

PubMed

Dillard, Alice; Matthan, Nirupa R; Spartano, Nicole L; Butkowski, Ann E; Lichtenstein, Alice H

2013-12-01

Dietary modification alters plasma lipoprotein profiles and atherosclerotic lesion progression in humans and some animal models. Variability in response to diet induced atherosclerosis has been reported in hamsters. Assessed was the interaction between background diet composition and dietary fat type on aortic cholesterol accumulation, lipoprotein profiles, hepatic lipids and selected genes. F1B Golden Syrian hamsters (20/group) were fed (12 weeks) semi-purified or non-purified diets containing either 10 % (w/w) coconut oil or safflower oil and 0.15 % (w/w) cholesterol. The non-purified diets relative to semi-purified diets resulted in significantly higher TC (72 % [percent difference] and 38 %, coconut oil and safflower oil, respectively) and nHDL-C (84 and 61 %, coconut oil and safflower oil, respectively), and lower HDL-C (-47 and -45 %, coconut oil and safflower oil, respectively) concentrations. Plasma triacylglycerol concentrations in the hamsters fed the non-purified coconut oil-supplemented diets were three- to fourfold higher than non-purified safflower oil-supplemented, and both semi-purified diets. With the exception of HDL-C, a significant effect of fat type was observed in TC, nHDL-C and triacylglycerol (all P < 0.05) concentrations. Regardless of diet induced differences in lipoprotein profiles, there was no significant effect on aortic cholesterol accumulation. There was an inverse relationship between plasma nHDL-C and triacylglycerol, and hepatic cholesteryl ester content (P < 0.001). Diet induced differences in hepatic gene transcription (LDL receptor, apoB-100, microsomal transfer protein) were not reflected in protein concentrations. Although hamsters fed non-purified and/or saturated fatty acid-supplemented diets had more atherogenic lipoprotein profiles compared to hamsters fed semi-purified and/or polyunsaturated fatty acid-supplemented diets these differences were not reflected in aortic cholesterol accumulation.

Hepatic entrapment of esterified cholesterol drives continual expansion of whole body sterol pool in lysosomal acid lipase-deficient mice

PubMed Central

Aqul, Amal; Lopez, Adam M.; Posey, Kenneth S.; Taylor, Anna M.; Repa, Joyce J.; Burns, Dennis K.

2014-01-01

Cholesteryl ester storage disease (CESD) results from loss-of-function mutations in LIPA, the gene that encodes lysosomal acid lipase (LAL). Hepatomegaly and deposition of esterified cholesterol (EC) in multiple organs ensue. The present studies quantitated rates of synthesis, absorption, and disposition of cholesterol, and whole body cholesterol pool size in a mouse model of CESD. In 50-day-old lal−/− and matching lal+/+ mice fed a low-cholesterol diet, whole animal cholesterol content equalled 210 and 50 mg, respectively, indicating that since birth the lal−/− mice sequestered cholesterol at an average rate of 3.2 mg·day−1·animal−1. The proportion of the body sterol pool contained in the liver of the lal−/− mice was 64 vs. 6.3% in their lal+/+ controls. EC concentrations in the liver, spleen, small intestine, and lungs of the lal−/− mice were elevated 100-, 35-, 15-, and 6-fold, respectively. In the lal−/− mice, whole liver cholesterol synthesis increased 10.2-fold, resulting in a 3.2-fold greater rate of whole animal sterol synthesis compared with their lal+/+ controls. The rate of cholesterol synthesis in the lal−/− mice exceeded that in the lal+/+ controls by 3.7 mg·day−1·animal−1. Fractional cholesterol absorption and fecal bile acid excretion were unchanged in the lal−/− mice, but their rate of neutral sterol excretion was 59% higher than in their lal+/+ controls. Thus, in this model, the continual expansion of the body sterol pool is driven by the synthesis of excess cholesterol, primarily in the liver. Despite the severity of their disease, the median life span of the lal−/− mice was 355 days. PMID:25147230

Quantitation of the rates of hepatic and intestinal cholesterol synthesis in lysosomal acid lipase-deficient mice before and during treatment with ezetimibe.

PubMed

Chuang, Jen-Chieh; Lopez, Adam M; Turley, Stephen D

2017-07-01

Esterified cholesterol (EC) and triglycerides, contained within lipoproteins taken up by cells, are hydrolysed by lysosomal acid lipase (LAL) in the late endosomal/lysosomal (E/L) compartment. The resulting unesterified cholesterol (UC) is transported via Niemann-Pick type C2 and C1 into the cytosolic compartment where it enters a putative pool of metabolically active cholesterol that is utilized in accordance with cellular needs. Loss-of-function mutations in LIPA, the gene encoding LAL, result in dramatic increases in tissue concentrations of EC, a hallmark feature of Wolman disease and cholesteryl ester storage disease (CESD). The lysosomal sequestration of EC causes cells to respond to a perceived deficit of sterol by increasing their rate of cholesterol synthesis, particularly in the liver. A similar compensatory response occurs with treatments that disrupt the enterohepatic movement of cholesterol or bile acids. Here we measured rates of cholesterol synthesis in vivo in the liver and small intestine of a mouse model for CESD given the cholesterol absorption inhibitor ezetimibe from weaning until early adulthood. Consistent with previous findings, this treatment significantly reduced the amount of EC sequestered in the liver (from 132.43±7.35 to 70.07±6.04mg/organ) and small intestine (from 2.78±0.21 to 1.34±0.09mg/organ) in the LAL-deficient mice even though their rates of hepatic and intestinal cholesterol synthesis were either comparable to, or exceeded those in matching untreated Lal -/- mice. These data reveal the role of intestinal cholesterol absorption in driving the expansion of tissue EC content and disease progression in LAL deficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

Blood lipid-lowering and antioxidant effects of a structured lipid containing monoacylglyceride enriched with monounsaturated fatty acids in C57BL/6 mice.

PubMed

Cho, Kyung-Hyun; Lee, Jeung-Hee; Kim, Jin-Man; Park, Sang Hyun; Choi, Myung-Sook; Lee, Yun-Mi; Choi, Inho; Lee, Ki-Teak

2009-04-01

We recently reported that a synthetic edible oil-containing monoacylglyceride (MAG) and diacylglyceride (DAG) exerted anti-atherosclerotic effects. In order to further investigate the activities and individual effects of MAG and DAG on the atherosclerotic process, we prepared a structured oil with various MAG and DAG contents and tested them both in vitro and in vivo, using C57BL/6 mice. The structured oil to be tested was mixed (final concentration 5%, wt/wt) with a high-cholesterol high-fat diet (1.2% cholesterol/15% fat/0.5% sodium cholate) and provided to the mice for 7 weeks. After administration, the mice consuming MAG97%-oil and DAG50%/MAG10%-oil evidenced 17% and 24% decreases in plasma total cholesterol (TC) level, respectively, as compared to a group of mice fed on lard. The experimental mice also had reduced plasma triglyceride concentrations and elevated high-density lipoprotein-cholesterol to TC ratios, by up to 31% in the case of the DAG50%/MAG10%-oil fed mice. The mice fed on MAG97%-oil exhibited elevated plasma antioxidant activity and lecithin:cholesterol acyltransferase activity. Histological assessments of the livers of the mice showed that the consumption of MAG-containing oil attenuated the adhesion of inflammatory cells and also ameliorated fatty liver changes, as compared to what was observed in the case of DAG85%-oil consumption. In conclusion, the MAG-containing oil exhibited anti-inflammatory and antioxidant activities in vivo, as well as in vitro inhibitory activity against human cholesteryl ester transfer protein. These results provide us with new insights into MAG-containing oil in terms of hypocholesterolemic effects and antioxidant activities.

The ACAT inhibitor CP-113,818 markedly reduces amyloid pathology in a mouse model of Alzheimer's disease.

PubMed

Hutter-Paier, Birgit; Huttunen, Henri J; Puglielli, Luigi; Eckman, Christopher B; Kim, Doo Yeon; Hofmeister, Alexander; Moir, Robert D; Domnitz, Sarah B; Frosch, Matthew P; Windisch, Manfred; Kovacs, Dora M

2004-10-14

Amyloid beta-peptide (Abeta) accumulation in specific brain regions is a pathological hallmark of Alzheimer's disease (AD). We have previously reported that a well-characterized acyl-coenzyme A: cholesterol acyltransferase (ACAT) inhibitor, CP-113,818, inhibits Abeta production in cell-based experiments. Here, we assessed the efficacy of CP-113,818 in reducing AD-like pathology in the brains of transgenic mice expressing human APP(751) containing the London (V717I) and Swedish (K670M/N671L) mutations. Two months of treatment with CP-113,818 reduced the accumulation of amyloid plaques by 88%-99% and membrane/insoluble Abeta levels by 83%-96%, while also decreasing brain cholesteryl-esters by 86%. Additionally, soluble Abeta(42) was reduced by 34% in brain homogenates. Spatial learning was slightly improved and correlated with decreased Abeta levels. In nontransgenic littermates, CP-113,818 also reduced ectodomain shedding of endogenous APP in the brain. Our results suggest that ACAT inhibition may be effective in the prevention and treatment of AD by inhibiting generation of the Abeta peptide.

Association of blood lipids with Alzheimer's disease: A comprehensive lipidomics analysis.

PubMed

Proitsi, Petroula; Kim, Min; Whiley, Luke; Simmons, Andrew; Sattlecker, Martina; Velayudhan, Latha; Lupton, Michelle K; Soininen, Hillka; Kloszewska, Iwona; Mecocci, Patrizia; Tsolaki, Magda; Vellas, Bruno; Lovestone, Simon; Powell, John F; Dobson, Richard J B; Legido-Quigley, Cristina

2017-02-01

The aim of this study was to (1) replicate previous associations between six blood lipids and Alzheimer's disease (AD) (Proitsi et al 2015) and (2) identify novel associations between lipids, clinical AD diagnosis, disease progression and brain atrophy (left/right hippocampus/entorhinal cortex). We performed untargeted lipidomic analysis on 148 AD and 152 elderly control plasma samples and used univariate and multivariate analysis methods. We replicated our previous lipids associations and reported novel associations between lipids molecules and all phenotypes. A combination of 24 molecules classified AD patients with >70% accuracy in a test and a validation data set, and we identified lipid signatures that predicted disease progression (R 2  = 0.10, test data set) and brain atrophy (R 2  ≥ 0.14, all test data sets except left entorhinal cortex). We putatively identified a number of metabolic features including cholesteryl esters/triglycerides and phosphatidylcholines. Blood lipids are promising AD biomarkers that may lead to new treatment strategies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Modified high-density lipoproteins by artificial sweetener, aspartame, and saccharin, showed loss of anti-atherosclerotic activity and toxicity in zebrafish.

PubMed

Kim, Jae-Yong; Park, Ki-Hoon; Kim, Jihoe; Choi, Inho; Cho, Kyung-Hyun

2015-01-01

Safety concerns have been raised regarding the association of chronic consumption of artificial sweeteners (ASs) with metabolic disorders, especially in the heart and brain. There has been no information on the in vivo physiological effects of AS consumption in lipoprotein metabolism. High-dosage treatment (final 25, 50, and 100 mM) with AS (aspartame, acesulfame K, and saccharin) to human high-density lipoprotein (HDL) induced loss of antioxidant ability along with elevated atherogenic effects. Aspartame-treated HDL3 (final 100 mM) almost all disappeared due to putative proteolytic degradation. Aspartame- and saccharin-treated HDL3 showed more enhanced cholesteryl ester transfer activity, while their antioxidant ability was disappeared. Microinjection of the modified HDL3 exacerbated the inflammatory death in zebrafish embryos in the presence of oxLDL. These results show that AS treatment impaired the beneficial functions of HDL, resulting in loss of antioxidant and anti-atherogenic activities. These results suggest that aspartame and saccharin could be toxic to the human circulation system as well as embryonic development via impairment of lipoprotein function.

Role of contact inhibition in the regulation of receptor-mediated uptake of low density lipoprotein in cultured vascular endothelial cells.

PubMed Central

Vlodavsky, I; Fielding, P E; Fielding, C J; Gospodarowicz, D

1978-01-01

Bovine vascular endothelial cells during logarithmic growth bind, internalize, and degrade low density lipoprotein (LDL) via a receptor-mediated pathway. However, contact-inhibited (confluent) monolayers bind but do not internalize LDL. This is in contrast to aortic smooth muscle cells or endothelial cells that have lost the property of contact inhibition. These cells internalize and degrade LDL at both high and low cell densities. The LDL receptors of smooth muscle and sparse endothelial cells down-regulate in response to LDL. In contrast, normal endothelial cells at confluency show little response. When contact inhibition in endothelial monolayers was locally released by wounding, and LDL was present, only cells released from contact inhibition accumulated LDL cholesterol. In smooth muscle cells under the same conditions, the entire culture interiorized lipid. It thus appears that in endothelial cells, unlike smooth muscle cells, contact inhibition is the major factor regulating cellular uptake of LDL cholesteryl ester. Reversal of contact inhibition by wounding provides a mechanism by which the endothelium could be the primary initiator of the atherosclerotic plaque. Images PMID:203937

Genetic variants involved in gallstone formation and capsaicin metabolism, and the risk of gallbladder cancer in Chilean women

PubMed Central

Báez, Sergio; Tsuchiya, Yasuo; Calvo, Alfonso; Pruyas, Martha; Nakamura, Kazutoshi; Kiyohara, Chikako; Oyama, Mari; Yamamoto, Masaharu

2010-01-01

AIM: To determine the effects of genetic variants associated with gallstone formation and capsaicin (a pungent component of chili pepper) metabolism on the risk of gallbladder cancer (GBC). METHODS: A total of 57 patients with GBC, 119 patients with gallstones, and 70 controls were enrolled in this study. DNA was extracted from their blood or paraffin block sample using standard commercial kits. The statuses of the genetic variants were assayed using Taqman® SNP Genotyping Assays or Custom Taqman® SNP Genotyping Assays. RESULTS: The non-ancestral T/T genotype of apolipoprotein B rs693 polymorphism was associated with a decreased risk of GBC (OR: 0.14, 95% CI: 0.03-0.63). The T/T genotype of cholesteryl ester transfer protein (CETP) rs708272 polymorphism was associated with an increased risk of GBC (OR: 5.04, 95% CI: 1.43-17.8). CONCLUSION: Genetic variants involved in gallstone formation such as the apolipoprotein B rs693 and CETP rs708272 polymorphisms may be related to the risk of developing GBC in Chilean women. PMID:20082485

[New agents for hypercholesterolemia].

PubMed

Pintó, Xavier; García Gómez, María Carmen

2016-02-19

An elevated proportion of high cardiovascular risk patients do not achieve the therapeutic c-LDL goals. This owes to physicians' inappropriate or insufficient use of cholesterol lowering medications or to patients' bad tolerance or therapeutic compliance. Another cause is an insufficient efficacy of current cholesterol lowering drugs including statins and ezetimibe. In addition, proprotein convertase subtilisin kexin type 9 inhibitors are a new cholesterol lowering medications showing safety and high efficacy to reduce c-LDL in numerous already performed or underway clinical trials, potentially allowing an optimal control of hypercholesterolemia in most patients. Agents inhibiting apolipoprotein B synthesis and microsomal transfer protein are also providing a new potential to decrease cholesterol in patients with severe hypercholesterolemia and in particular in homozygote familial hypercholesterolemia. Last, cholesteryl ester transfer protein inhibitors have shown powerful effects on c-HDL and c-LDL, although their efficacy in cardiovascular prevention and safety has not been demonstrated yet. We provide in this article an overview of the main characteristics of therapeutic agents for hypercholesterolemia, which have been recently approved or in an advanced research stage. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Laser Desorption/Ionization Mass Spectrometric Imaging of Endogenous Lipids from Rat Brain Tissue Implanted with Silver Nanoparticles

NASA Astrophysics Data System (ADS)

Muller, Ludovic; Baldwin, Kathrine; Barbacci, Damon C.; Jackson, Shelley N.; Roux, Aurélie; Balaban, Carey D.; Brinson, Bruce E.; McCully, Michael I.; Lewis, Ernest K.; Schultz, J. Albert; Woods, Amina S.

2017-08-01

Mass spectrometry imaging (MSI) of tissue implanted with silver nanoparticulate (AgNP) matrix generates reproducible imaging of lipids in rodent models of disease and injury. Gas-phase production and acceleration of size-selected 8 nm AgNP is followed by controlled ion beam rastering and soft landing implantation of 500 eV AgNP into tissue. Focused 337 nm laser desorption produces high quality images for most lipid classes in rat brain tissue (in positive mode: galactoceramides, diacylglycerols, ceramides, phosphatidylcholines, cholesteryl ester, and cholesterol, and in negative ion mode: phosphatidylethanolamides, sulfatides, phosphatidylinositol, and sphingomyelins). Image reproducibility in serial sections of brain tissue is achieved within <10% tolerance by selecting argentated instead of alkali cationized ions. The imaging of brain tissues spotted with pure standards was used to demonstrate that Ag cationized ceramide and diacylglycerol ions are from intact, endogenous species. In contrast, almost all Ag cationized fatty acid ions are a result of fragmentations of numerous lipid types having the fatty acid as a subunit. Almost no argentated intact fatty acid ions come from the pure fatty acid standard on tissue.

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

Kwon, Hyock Joo; Abi-Mosleh, Lina; Wang, Michael L.

LDL delivers cholesterol to lysosomes by receptor-mediated endocytosis. Exit of cholesterol from lysosomes requires two proteins, membrane-bound Niemann-Pick C1 (NPC1) and soluble NPC2. NPC2 binds cholesterol with its isooctyl side chain buried and its 3{beta}-hydroxyl exposed. Here, we describe high-resolution structures of the N-terminal domain (NTD) of NPC1 and complexes with cholesterol and 25-hydroxycholesterol. NPC1(NTD) binds cholesterol in an orientation opposite to NPC2: 3{beta}-hydroxyl buried and isooctyl side chain exposed. Cholesterol transfer from NPC2 to NPC1(NTD) requires reorientation of a helical subdomain in NPC1(NTD), enlarging the opening for cholesterol entry. NPC1 with point mutations in this subdomain (distinct from themore » binding subdomain) cannot accept cholesterol from NPC2 and cannot restore cholesterol exit from lysosomes in NPC1-deficient cells. We propose a working model wherein after lysosomal hydrolysis of LDL-cholesteryl esters, cholesterol binds NPC2, which transfers it to NPC1(NTD), reversing its orientation and allowing insertion of its isooctyl side chain into the outer lysosomal membranes.« less

Flexible and Hierarchical Metal-Organic Framework Composites for High-Performance Catalysis.

PubMed

Huang, Ning; Drake, Hannah; Li, Jialuo; Pang, Jiangdong; Wang, Ying; Yuan, Shuai; Wang, Qi; Cai, Peiyu; Qin, Junsheng; Zhou, Hong-Cai

2018-05-18

The development of new types of porous composite materials is of great significance owing to their potentially improved performance over those of individual components and extensive applications in separation, energy storage, and heterogeneous catalysis. In this work, we integrated mesoporous metal-organic frameworks (MOFs) with macroporous melamine foam (MF) using a one-pot process, generating a series of MOF/MF composite materials with preserved crystallinity, hierarchical porosity, and increased stability over that of melamine foam. The MOF nanocrystals were threaded by the melamine foam networks, resembling a ball-and-stick model overall. As a proof-of-concept study, the resulting MOF/MF composite materials were employed as an effective heterogeneous catalyst for the epoxidation of cholesteryl esters. Combining the advantages of interpenetrative mesoporous and macroporous structures, the MOF/melamine foam composite provided higher dispersibility and more accessibility of catalytic sites, exhibiting excellent catalytic performance. This strategy constitutes an important step forward the development of other MOF composites and exploration of their high-performance catalysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel HDL-directed pharmacotherapeutic strategies

PubMed Central

deGoma, Emil M.; Rader, Daniel J.

2011-01-01

The burden of atherothrombotic cardiovascular disease remains high despite currently available optimum medical therapy. To address this substantial residual risk, the development of novel therapies that attempt to harness the atheroprotective functions of HDL is a major goal. These functions include the critical role of HDL in reverse cholesterol transport, and its anti-inflammatory, antithrombotic, and antioxidant activities. Discoveries in the past decade have shed light on the complex metabolic and antiatherosclerotic pathways of HDL. These insights have fueled the development of HDL-targeted drugs, which can be classified among four different therapeutic approaches: directly augmenting apolipoprotein A-I (apo A-I) levels, such as with apo A-I infusions and upregulators of endogenous apo A-I production; indirectly augmenting apo A-I and HDL-cholesterol levels, such as through inhibition of cholesteryl ester transfer protein or endothelial lipase, or through activation of the high-affinity niacin receptor GPR109A; mimicking the functionality of apo A-I with apo A-I mimetic peptides; and enhancing steps in the reverse cholesterol transport pathway, such as via activation of the liver X receptor or of lecithin–cholesterol acyltransferase. PMID:21243009

An overview of the new frontiers in the treatment of atherogenic dyslipidemias.

PubMed

Rached, F H; Chapman, M J; Kontush, A

2014-07-01

Cardiovascular diseases (CVDs) are the leading cause of morbidity/mortality worldwide. Dyslipidemia is a major risk factor for premature atherosclerosis and CVD. Lowering low-density-lipoprotein cholesterol (LDL-C) levels is well established as an intervention for the reduction of CVDs. Statins are the first-line drugs for treatment of dyslipidemia, but they do not address all CVD risk. Development of novel therapies is ongoing and includes the following: (i) reduction of LDL-C concentrations using antibodies to proprotein convertase subtilisin/kexin-9, antisense oligonucleotide inhibitors of apolipoprotein B production, microsomal transfer protein (MTP) inhibitors, and acyl-coenzyme A cholesterol acyl transferase inhibitors; (ii) reduction in levels of triglyceride-rich lipoproteins with ω-3 fatty acids, MTP inhibitors, and diacylglycerol acyl transferase-1 inhibitors; and (iii) increase of high-density-lipoprotein (HDL) cholesterol levels, HDL particle numbers, and/or HDL functionality using cholesteryl ester transfer protein inhibitors, HDL-derived agents, apolipoprotein AI mimetic peptides, and microRNAs. Large prospective outcome trials of several of these emerging therapies are under way, and thrilling progress in the field of lipid management is anticipated.

Synthesis of fatty acid methyl ester from used vegetable cooking oil by solid reusable Mg 1-x Zn 1+x O2 catalyst.

PubMed

Olutoye, M A; Hameed, B H

2011-02-01

Fatty acid methyl ester was produced from used vegetable cooking oil using Mg(1-)(x) Zn(1+)(x)O(2) solid catalyst and the performance monitored in terms of ester content obtained. Used vegetable cooking oil was employed to reduce operation cost of biodiesel. The significant operating parameters which affect the overall yield of the process were studied. The highest ester content, 80%, was achieved with the catalyst during 4h 15 min reaction at 188°C with methanol to oil ratio of 9:1 and catalyst loading of 2.55 wt% oil. Also, transesterification of virgin oil gave higher yield with the heterogeneous catalyst and showed high selectivity towards ester production. The used vegetable cooking oil did not require any rigorous pretreatment. Catalyst stability was examined and there was no leaching of the active components, and its performance was as good at the fourth as at the first cycle. Copyright © 2010 Elsevier Ltd. All rights reserved.

Quantitative Profiling of Major Neutral Lipid Classes in Human Meibum by Direct Infusion Electrospray Ionization Mass Spectrometry

PubMed Central

Chen, Jianzhong; Green, Kari B.; Nichols, Kelly K.

2013-01-01

Purpose. The purpose of this investigation was to better understand lipid composition in human meibum. Methods. Intact lipids in meibum samples were detected by direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis in positive detection mode using sodium iodide (NaI) as an additive. The peak intensities of all major types of lipid species, that is, wax esters (WEs), cholesteryl esters (CEs), and diesters (DEs) were corrected for peak overlapping and isotopic distribution; an additional ionization efficiency correction was performed for WEs and CEs, which was simplified by the observation that the corresponding ionization efficiency was primarily dependent on the specific lipid class and saturation degree of the lipids while independent of the carbon chain length. A set of WE and CE standards was spiked in meibum samples for ionization efficiency determination and absolute quantitation. Results. The absolute amount (μmol/mg) for each of 51 WEs and 31 CEs in meibum samples was determined. The summed masses for 51 WEs and 31 CEs accounted for 48 ± 4% and 40 ± 2%, respectively, of the total meibum lipids. The mass percentages of saturated and unsaturated species were determined to be 75 ± 2% and 25 ± 1% for CEs and 14 ± 1% and 86 ± 1% for WEs. The profiles for two types of DEs were also obtained, which include 42 α,ω Type II DEs, and 21 ω Type I-St DEs. Conclusions. Major neutral lipid classes in meibum samples were quantitatively profiled by ESI-MS analysis with NaI additive. PMID:23847307

Regulation of the activity and fatty acid specificity of lecithin-cholesterol acyltransferase by sphingomyelin, and its metabolites ceramide and ceramide phosphate†

PubMed Central

Subbaiah, Papasani V.; Horvath, Peter; Achar, Srinivasa B.

2006-01-01

Sphingomyelin (SM), the second most abundant phospholipid in plasma lipoproteins, was previously shown to be a physiological inhibitor of the lecithin-cholesterol acyltransferase (LCAT) reaction. In this study, we investigated the effects of its metabolites, ceramide and ceramide phosphate, on the activity and fatty acid specificity of LCAT in vitro. Treatment of SM-containing substrate with SMase C, which hydrolyzes SM to ceramide, abolished the inhibitory effect of SM, whereas treatment with SMase D, which hydrolyzes it to ceramide phosphate, increased the inhibition. Although incorporation of ceramide into the substrate in the absence of SM activated the LCAT reaction only modestly, its co-incorporation with SM neutralized the inhibitory effect of SM. Ceramide phosphate, on the other hand, inhibited the LCAT reaction more strongly than SM. The effects of the sphingolipids were similar on the phospholipase A and cholesterol esterification reactions of the enzyme, indicating that they regulate the binding of phosphatidylcholine (PC) to the active site, rather than the esterification step. Ceramide incorporation into the substrate stimulated the synthesis of unsaturated cholesteryl esters at the expense of saturated esters. However these effects on fatty acid specificity disappeared when the PC substrates were incorporated into an inert diether PC matrix, suggesting that ceramide increases the availability of polyunsaturated PCs to the enzyme by altering the macromolecular structure of the substrate particle. Since the plasma ceramide levels are increased during inflammation, these results indicate that the activity and fatty acid specificity of LCAT may be altered during the inflammatory response. PMID:16605271

Familial dyslipidaemias: an overview of genetics, pathophysiology and management.

PubMed

Hachem, Sahar B; Mooradian, Arshag D

2006-01-01

Plasma lipid disorders can occur either as a primary event or secondary to an underlying disease or use of medications. Familial dyslipidaemias are traditionally classified according to the electrophoretic profile of lipoproteins. In more recent texts, this phenotypic classification has been replaced with an aetiological classification. Familial dyslipidaemias are generally grouped into disorders leading to hypercholesterolaemia, hypertriglyceridaemia, a combination of hyper-cholesterolaemia and hypertriglyceridaemia, or abnormal high-density lipoprotein-cholesterol (HDL-C) levels. The management of these disorders requires an understanding of plasma lipid and lipoprotein metabolism. Lipid transport and metabolism involves three general pathways: (i) the exogenous pathway, whereby chylomicrons are synthesised by the small intestine, and dietary triglycerides (TGs) and cholesterol are transported to various cells of the body; (ii) the endogenous pathway, whereby very low-density lipoprotein-cholesterol (VLDL-C) and TGs are synthesised by the liver for transport to various tissues; and (iii) the reverse cholesterol transport, whereby HDL cholesteryl ester is exchanged for TGs in low-density lipoptrotein (LDL) and VLDL particles through cholesteryl ester transfer protein in a series of steps to remove cholesterol from the peripheral tissues for delivery to the liver and steroidogenic organs. The plasma lipid profile can provide a framework to guide the selection of appropriate diet and drug treatment. Many patients with hyperlipoproteinaemia can be treated effectively with diet. However, dietary regimens are often insufficient to bring lipoprotein levels to within acceptable limits. In this article, we review lipid transport and metabolism, discuss the more common lipid disorders and suggest some management guidelines. The choice of a particular agent depends on the baseline lipid profile achieved after 6-12 weeks of intense lifestyle changes and possible use of dietry supplements such as stanols and plant sterols. If the predominant lipid abnormality is hypertriglyceridaemia, omega-3 fatty acids, a fibric acid derivative (fibrate) or nicotinic acid would be considered as the first choice of therapy. In subsequent follow-up, when LDL-C is >130 mg/dL (3.36 mmol/L) then an HMG-CoA reductase inhibitor (statin) should be added as a combination therapy. If the serum TG levels are <500 mg/dL (2.26 mmol/L) and the LDL-C values are over 130 mg/dL (3.36 mmol/L) then a statin would be the first drug of choice. The statin dose can be titrated up to achieve the therapeutic goal or, alternatively, ezetimibe can be added. A bile acid binding agent is an option if the serum TG levels do not exceed 200 mg/dL (5.65 mmol/L), otherwise a fibrate or nicotinic acid should be considered. The decision to treat a particular person has to be individualised.

New sterically stabilized vesicles based on nonionic surfactant, cholesterol, and poly(ethylene glycol)-cholesterol conjugates.

PubMed Central

Beugin, S; Edwards, K; Karlsson, G; Ollivon, M; Lesieur, S

1998-01-01

Monomethoxypoly(ethylene glycol) cholesteryl carbonates (M-PEG-Chol) with polymer chain molecular weights of 1000 (M-PEG1000-Chol) and 2000 (M-PEG2000-Chol) have been newly synthesized and characterized. Their aggregation behavior in mixture with diglycerol hexadecyl ether (C16G2) and cholesterol has been examined by cryotransmission electron microscopy, high-performance gel exclusion chromatography, and quasielastic light scattering. Nonaggregated, stable, unilamellar vesicles were obtained at low polymer levels with optimal shape and size homogeneity at cholesteryl conjugate/ lipids ratios of 10 mol% M-PEG1000-Chol or 5 mol% M-PEG2000-Chol, corresponding to the theoretically predicted brush conformational state of the PEG chains. At 20 mol% M-PEG1000-Chol or 10 mol% M-PEG2000-Chol, the saturation threshold of the C16G2/cholesterol membrane in polymer is exceeded, and open disk-shaped aggregates are seen in coexistence with closed vesicles. Higher levels up to 30 mol% lead to the complete solubilization of the vesicles into disk-like structures of decreasing size with increasing PEG content. This study underlines the bivalent role of M-PEG-Chol derivatives: while behaving as solubilizing surfactants, they provide an efficient steric barrier, preventing the vesicles from aggregation and fusion over a period of at least 2 weeks. PMID:9635773

Biodiesel production from vegetable oil and waste animal fats in a pilot plant.

PubMed

Alptekin, Ertan; Canakci, Mustafa; Sanli, Huseyin

2014-11-01

In this study, corn oil as vegetable oil, chicken fat and fleshing oil as animal fats were used to produce methyl ester in a biodiesel pilot plant. The FFA level of the corn oil was below 1% while those of animal fats were too high to produce biodiesel via base catalyst. Therefore, it was needed to perform pretreatment reaction for the animal fats. For this aim, sulfuric acid was used as catalyst and methanol was used as alcohol in the pretreatment reactions. After reducing the FFA level of the animal fats to less than 1%, the transesterification reaction was completed with alkaline catalyst. Due to low FFA content of corn oil, it was directly subjected to transesterification. Potassium hydroxide was used as catalyst and methanol was used as alcohol for transesterification reactions. The fuel properties of methyl esters produced in the biodiesel pilot plant were characterized and compared to EN 14214 and ASTM D6751 biodiesel standards. According to the results, ester yield values of animal fat methyl esters were slightly lower than that of the corn oil methyl ester (COME). The production cost of COME was higher than those of animal fat methyl esters due to being high cost biodiesel feedstock. The fuel properties of produced methyl esters were close to each other. Especially, the sulfur content and cold flow properties of the COME were lower than those of animal fat methyl esters. The measured fuel properties of all produced methyl esters met ASTM D6751 (S500) biodiesel fuel standards. Copyright © 2014 Elsevier Ltd. All rights reserved.

Online LC-GC-based analysis of minor lipids in various tree nuts and peanuts.

PubMed

Esche, Rebecca; Müller, Luisa; Engel, Karl-Heinz

2013-11-27

As information on free sterols/stanols and steryl/stanyl esters in nuts is lacking, the compositions and contents of these lipid constituents in ten different nut types were analyzed. The applied approach was based on online liquid chromatography-gas chromatography and enabled the simultaneous analysis of free sterols/stanols and individual steryl/stanyl fatty acid esters, and additionally of tocopherols and squalene. Total contents of free sterols/stanols ranged from 0.62 mg/g nut in hazelnuts to 1.61 mg/g nut in pistachios, with sitosterol as the predominant compound. Total contents of steryl/stanyl fatty acid esters were in the range of 0.11-1.26 mg/g nut, being lowest in Brazil nuts and highest in pistachios. There were considerable differences between the various nut types not only regarding the contents, but also the compositions of both classes. The levels of tocopherols were highest in pine nuts (0.33 mg/g nut); those of squalene were remarkably high in Brazil nuts (1.11 mg/g nut).

Analysis of seed phorbol-ester and curcin content together with genetic diversity in multiple provenances of Jatropha curcas L. from Madagascar and Mexico.

PubMed

He, Wei; King, Andrew J; Khan, M Awais; Cuevas, Jesús A; Ramiaramanana, Danièle; Graham, Ian A

2011-10-01

Jatropha curcas L. has been promoted as an oilseed crop for use to meet the increased world demand for vegetable oil production, and in particular, as a feedstock for biodiesel production. Seed meal is a protein-rich by-product of vegetable oil extraction, which can either be used as an organic fertilizer, or converted to animal feed. However, conversion of J. curcas seed meal into animal feed is complicated by the presence of toxins, though plants producing "edible" or "non-toxic" seeds occur in Mexico. Toxins present in the seeds of J. curcas include phorbol esters and a type-I ribosome inactivating protein (curcin). Although the edible seeds of J. curcas are known to lack phorbol esters, the curcin content of these seeds has not previously been studied. We analyzed the phorbol ester and curcin content of J. curcas seeds obtained from Mexico and Madagascar, and conclude that while phorbol esters are lacking in edible seeds, both types contain curcin. We also analyzed spatial distribution of these toxins in seeds. Phorbol-esters were most concentrated in the tegmen. Curcin was found in both the endosperm and tegmen. We conclude that seed toxicity in J. curcas is likely to be due to a monogenic trait, which may be under maternal control. We also conducted AFLP analysis and conclude that genetic diversity is very limited in the Madagascan collection compared to the Mexican collection. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Effect of sugar fatty acid esters on rumen fermentation in vitro.

PubMed

Wakita, M; Hoshino, S

1987-11-01

1. The effect of sugar fatty acid esters (SFEs; currently used as food additives for human consumption) on rumen volatile fatty acids (VFA) and gas production was studied with sheep rumen contents in vitro. 2. Some SFEs having monoester contents of more than 70% increased the molar proportion of propionate in conjunction with reduction in the acetate:propionate ratio when the individual SFE was added to rumen contents in a final concentration of 4 g/l. Laurate sugar ester was the most potent propionate enhancer and rumen gas depressor, the effective dose being as low as 1 g/l in a final concentration. Fatty acid esters other than SFEs had little, if any, effect on rumen VFA production and their molar proportions. 3. Approximately 50% of laurate sugar ester was hydrolysed by in vitro incubation with rumen fluid for 2 h. The addition of fatty acids and sucrose was also effective in the alterations of rumen VFA and gas production. However, the effect of SFEs on in vitro rumen fermentation was significantly greater than that of their constituent fatty acids or sucrose, or both. Accordingly, the effect appeared to be ascribed to the complex action of SFE itself and to its constituents, free fatty acids and sucrose. 4. SFEs, at the level of 4 g/l, reduced substantially the froth formation (ingesta volume increase) and seemed to be effective for the prevention of bloat.

Combining mass spectrometry diagnostic and density functional theory calculations for a better understanding of the plasma polymerization of ethyl lactate.

PubMed

Ligot, S; Guillaume, M; Gerbaux, P; Thiry, D; Renaux, F; Cornil, J; Dubois, P; Snyders, R

2014-04-17

The focus of this work is on the growth mechanism of ethyl lactate-based plasma polymer film (ELPPF) that could be used as barrier coatings. In such an application, the ester density of the plasma polymer has to be controlled to tune the degradation rate of the material. Our strategy consists of correlating the plasma chemistry evaluated by RGA mass spectrometry and understanding, via DFT calculations, the chemistry of the synthesized thin films. The theoretical calculations helped us to understand the plasma chemistry in plasma ON and OFF conditions. From these data it is unambiguously shown that the signal m/z 75 can directly be correlated with the precursor density in the plasma phase. The combination of XPS and chemical derivatization experiments reveal that the ester content in the ELPFF can be tailored from 2 to 18 at. % by decreasing the RF power, which is perfectly correlated with the evolution of the plasma chemistry. Our results also highlight that the ELPPF chemistry, especially the ester content, is affected by the plasma mode of operation (continuous or pulsed discharge, at similar injected mean power) for similar ester content in the plasma. This could be related to different energy conditions at the interface of the growing films that could affect the sticking coefficient of the ester-bearing fragments.

Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

NASA Technical Reports Server (NTRS)

Chisnell, J. R.

1984-01-01

Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

Oil industry waste: a potential feedstock for biodiesel production.

PubMed

Abbas, Javeria; Hussain, Sabir; Iqbal, Muhammad Javid; Nadeem, Habibullah; Qasim, Muhammad; Hina, Saadia; Hafeez, Farhan

2016-08-01

The worldwide rising energy demands and the concerns about the sustainability of fossil fuels have led to the search for some low-cost renewable fuels. In this scenario, the production of biodiesel from various vegetable and animal sources has attracted worldwide attention. The present study was conducted to evaluate the production of biodiesel from the oil industry waste following base-catalysed transesterification. The transesterification reaction gave a yield of 83.7% by 6:1 methanol/oil molar ratio, at 60°C over 80 min of reaction time in the presence of NaOH. The gas chromatographic analysis of the product showed the presence of 16 fatty acid methyl esters with linoleic and oleic acid as principal components representing about 31% and 20.7% of the total methyl esters, respectively. The fourier transform infrared spectroscopy spectrum of oil industry waste and transesterified product further confirmed the formation of methyl esters. Furthermore, the fuel properties of oil industry waste methyl esters, such as kinematic viscosity, cetane number, cloud point, pour point, flash point, acid value, sulphur content, cold filter plugging point, copper strip corrosion, density, oxidative stability, higher heating values, ash content, water content, methanol content and total glycerol content, were determined and discussed in the light of ASTM D6751 and EN 14214 biodiesel standards. Overall, this study presents the production of biodiesel from the oil industry waste as an approach of recycling this waste into value-added products.

[The changes in contents and composition of phenolic acids during cell xylem growth in scots pine].

PubMed

Antonova, G F; Zheliznichenko, T V; Stasova, V V

2011-01-01

The contents and composition of alcohol soluble phenolic acids were studied during cell xylem growth in the course of wood annual increment formation in the stems of Scots pine. The cells of cambium zone, of two stages of expansion growth and the outset of secondary thickening zone (before lignification) were successively gathered from the stem segments of 25-old pine trees in the period of earlywood xylem formation with constant anatomical and histochemical control. The contents of free and bound forms of phenolic acids, isolated by 80% ethanol from tissues, as well as of their ethers and esters were calculated both per dry weight and per cell. The content and relation of the fractions and the composition of phenolic acid have been found to change significantly from cambium zone to the outset of tracheid secondary thickening. The character of the variations depends on a calculation method. According to the calculation per cell the amount of free and bound phenolic acids and in their composition of esters and especially ethers increased at the first step of expansion growth zone, decreased at the second one and rose again in the outset of secondary wall deposition. In dependence on the stage of cell development the pool of bound phenolic acids exceeded of free acid pool in 2-5 times. Sinapic and ferulic acids dominated in the composition of free hydroxycinnamic acids. The content and composition of hydroxycinnamic acids in ethers and esters depended on cell development phase. In cambium p-coumaric and sinapic acids were principal aglycons in ethers, at other stages these were sinapic and caffeic acids. The esters in cambium zone included essentially p-coumaric acid and at the other stages - sinapic and ferulic acids. At the first phase of growth benzoic acid was connected principally by ester bonds. The pool of these esters decreased from the first phase of growth to the outset of cell wall thickening and in proportion to this the level of free benzoic acid rose.

Formation and reduction of 3-monochloropropane-1,2-diol esters in peanut oil during physical refining.

PubMed

Li, Chang; Li, Linyan; Jia, Hanbing; Wang, Yuting; Shen, Mingyue; Nie, Shaoping; Xie, Mingyong

2016-05-15

In the present study, lab-scale physical refining processes were investigated for their effects on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters. The potential precursors, partial acylglycerols and chlorines were determined before each refining step. 3-MCPD esters were not detected in degummed and bleached oil when the crude oils were extracted by solvent. While in the hot squeezed crude oils, 3-MCPD esters were detected with low amounts. 3-MCPD esters were generated with maximum values in 1-1.5h at a certain deodorizing temperature (220-260°C). Chlorine seemed to be more effective precursor than partial acylglycerol. By washing bleached oil before deodorization with ethanol solution, the precursors were removed partially and the content of 3-MCPD esters decreased to some extent accordingly. Diacetin was found to reduce 3-MCPD esters effectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

On the biogenesis of lipid bodies in ancient eukaryotes: synthesis of triacylglycerols by a Toxoplasma DGAT1-related enzyme.

PubMed

Quittnat, Friederike; Nishikawa, Yoshifumi; Stedman, Timothy T; Voelker, Dennis R; Choi, Jae-Yeon; Zahn, Matthew M; Murphy, Robert C; Barkley, Robert M; Pypaert, Marc; Joiner, Keith A; Coppens, Isabelle

2004-11-01

In mammalian cells, the main stored neutral lipids are triacylglycerol and cholesteryl esters, which are produced by two related enzymes, acyl-CoA:diacylglycerol acyltransferase (DGAT) and acyl-CoA:cholesterol acyltransferase (ACAT), respectively. Very little is known about the metabolism, intracellular storage and function of neutral lipids in many pathogenic lower eukaryotes. In this paper, we have characterized the activity of an important triacylglycerol synthetic enzyme in the protozoan Toxoplasma gondii. A full-length cDNA and gene encoding a T. gondii DGAT1-related enzyme were identified and designated TgDGAT1. The gene is composed of 15 exons and 14 introns, and encodes a protein with a predicted M(r) 63.5kDa, containing signature motifs characteristic of the DGAT1 family. The native protein migrates at 44kDa under reducing conditions. TgDGAT1 is an integral membrane protein localized to the parasite cortical and perinuclear endoplasmic reticulum, with the C-terminus oriented to the lumen of the organelle. When a Saccharomyces cerevisiae mutant strain lacking neutral lipid production is transformed with TgDGAT1 cDNA, a significant DGAT activity is reconstituted, resulting in triacylglycerol synthesis and biogenesis of cytosolic lipid inclusions, resembling lipid bodies in T. gondii. No production of steryl esters is observed upon TgDGAT1 expression in yeast. In contrast to human DGAT1 lacking fatty acid specificity, TgDGAT1 preferentially incorporates palmitate. Our results indicate that parasitic protozoa are also neutral lipid accumulators and illustrate the first example of the existence of a functional DGAT gene in an ancient eukaryote, demonstrating that diacylglycerol esterification is evolutionarily conserved.

Expression and Characterization of a PNPLA3 Protein Isoform (I148M) Associated with Nonalcoholic Fatty Liver Disease*

PubMed Central

Huang, Yongcheng; Cohen, Jonathan C.; Hobbs, Helen H.

2011-01-01

A genetic variant of PNPLA3 (patatin-like phospholipase domain-containing 3; PNPLA3-I148M), a serine protease of unknown function, is associated with accumulation of triacylglycerol (TAG) in the liver. To determine the biological substrates of PNPLA3 and the effect of the I148M substitution on enzymatic activity and substrate specificity, we purified and characterized recombinant human PNPLA3 and PNPLA3-I148M. Maximal hydrolytic activity of PNPLA3 was observed against the three major glycerolipids, TAG, diacylglycerol, and monoacylglycerol, with a strong preference for oleic acid as the acyl moiety. Substitution of methionine for isoleucine at position 148 markedly decreased the Vmax of the enzyme for glycerolipids but had only a modest effect on the Km. Purified PNPLA3 also catalyzed the hydrolysis of oleoyl-CoA, but the Vmax was 100-fold lower for oleoyl-CoA than for triolein. The thioesterase activity required the catalytic serine but was only modestly decreased by the I148M substitution. The enzyme had little or no hydrolytic activity against the other lipid substrates tested, including phospholipids, cholesteryl ester, and retinyl esters. Neither the wild-type nor mutant enzyme catalyzed transfer of oleic acid from oleoyl-CoA to glycerophosphate, lysophosphatidic acid, or diacylglycerol, suggesting that the enzyme does not promote de novo TAG synthesis. Taken together, our results are consistent with the notion that PNPLA3 plays a role in the hydrolysis of glycerolipids and that the I148M substitution causes a loss of function, although we cannot exclude the possibility that the enzyme has additional substrates or activities. PMID:21878620

Plasma fatty acid profile in depressive disorder resembles insulin resistance state.

PubMed

Vareka, Tomas; Vecka, Marek; Jirak, Roman; Tvrzicka, Eva; Macasek, Jaroslav; Zak, Ales; Zeman, Miroslav

2012-01-01

Depressive disorder is related to an increased risk of type 2 diabetes mellitus (DM2) and cardiovascular disease (CVD). Insulin resistance (IR), connected with altered fatty acid (FA) composition, namely with decreased proportion of polyunsaturated FA could participate in these associations. The aim of the study was to investigate the composition of FA in plasma cholesterol esters (CE) and phosphatidylcholine (PC) as well as indices of insulin resistance and oxidative stress in the patients with depressive disorder. Parameters of lipid and glucose homeostasis, concentrations of FA in plasma cholesteryl esters (CE) and phosphatidylcholine (PC) and conjugated dienes in LDL were investigated in a group of 47 patients (9M/38F) with depression and compared with 47 control persons (16M/31F). Delta-9 desaturase (D9D) and D6D desaturase were estimated as product to precursor fatty acid ratios. In depressive patients increased concentrations of palmitoleic acid and total monounsaturated FA with decreased proportion of total polyunsaturated FA n-6 (PUFA n-6) (all p<0.05) in CE were found, while in PC increased proportion of saturated FA was observed (p<0.05). Moreover, index of D6D activity was significantly increased in PC and CE (p<0.05). Concomitantly, in depressive patients higher levels of plasma triacylglycerols (p<0.05), conjugated dienes in LDL (p<0.001) and HOMA index of IR (p<0.05) were found. Esterified FA composition of depressive patients revealed changes, similar to those, usually observed in insulin resistance. Dysregulation of FA could participate in the pathogenesis of depression and be associated with an increased risk of CVD and DM2.

Selective ablation of rabbit atherosclerotic plaque with less thermal effect by the control of pulse structure of a quantum cascade laser in the 5.7 μm wavelength range

NASA Astrophysics Data System (ADS)

Hashimura, Keisuke; Ishii, Katsunori; Awazu, Kunio

2016-03-01

Cholesteryl esters are main components of atherosclerotic plaques and have an absorption peak at the wavelength of 5.75 μm originated from C=O stretching vibration mode of ester bond. Our group achieved the selective ablation of atherosclerotic lesions using a quantum cascade laser (QCL) in the 5.7 μm wavelength range. QCLs are relatively new types of semiconductor lasers that can emit mid-infrared range. They are sufficiently compact and considered to be useful for clinical application. However, large thermal effects were observed because the QCL worked as quasicontinuous wave (CW) lasers due to its short pulse interval. Then we tried macro pulse irradiation (irradiation of pulses at intervals) of the QCL and achieved effective ablation with less-thermal effects than conventional quasi-CW irradiation. However, lesion selectivity might be changed by changing pulse structure. Therefore, in this study, irradiation effects of the macro pulse irradiation to rabbit atherosclerotic plaque and normal vessel were compared. The macro pulse width and the macro pulse interval were set to 0.5 and 12 ms, respectively, because the thermal relaxation time of rabbit normal and atherosclerotic aortas in the oscillation wavelength of the QCL was 0.5-12 ms. As a result, cutting difference was achieved between rabbit atherosclerotic and normal aortas by the macro pulse irradiation. Therefore, macro pulse irradiation of a QCL in the 5.7 μm wavelength range is effective for reducing thermal effects and selective ablation of the atherosclerotic plaque. QCLs have the potential of realizing less-invasive laser angioplasty.

Peroxide Bond Driven Dissociation of Hydroperoxy-Cholesterol Esters Following Collision Induced Dissociation

NASA Astrophysics Data System (ADS)

Hutchins, Patrick M.; Murphy, Robert C.

2011-05-01

Oxidative modification of polyunsaturated fatty acids, which occurs through enzymatic and nonenzymatic processes, is typically initiated by the attachment of molecular oxygen to an unsaturated fatty acyl chain forming a lipid hydroperoxide (LOOH). Enzymatic pathways are critical for cellular homeostasis but aberrant lipid peroxidation has been implicated in important pathologies. Analysis of primary oxidation products such as hydroperoxides has proven to be challenging for a variety of reasons. While negative ion electrospray ionization has been used for the specific detection of some LOOH species, hydroperoxide dehydration in the ion source has been a significant drawback. Here we describe positive ion electrospray ionization of ammoniated 13-hydroperoxy-9Z, 11E-octadecadienoyl cholesterol and 9-hydroperoxy-10E, 12Z-octadecadienoyl cholesterol, [M + NH4]+, following normal phase high-pressure liquid-chromatography. Dehydration in the ion source was not prevalent and the ammoniated molecular ion was the major species observed. Collisionally induced dissociation of the two positional isomers yielded unique product ion spectra resulting from carbon-carbon cleavages along their acyl chains. Further investigation of this behavior revealed that complex collision induced dissociations were initiated by scission of the hydroperoxide bond that drove subsequent acyl chain cleavages. Interestingly, some of the product ions retained the ammonium nitrogen through the formation of covalent carbon-nitrogen or oxygen-nitrogen bonds. These studies were carried out using hydroperoxy-octadecadienoate cholesteryl esters as model compounds, however the observed mechanisms of [LOOH + NH4]+ ionization and dissociation are likely applicable to the analysis of other lipid hydroperoxides and may serve as the basis for selective LOOH detection as well as aid in the identification of unknown lipid hydroperoxides.

Fat digestion by lingual lipase: mechanism of lipolysis in the stomach and upper small intestine.

PubMed

Liao, T H; Hamosh, P; Hamosh, M

1984-05-01

Ten to 30% of dietary fat is hydrolyzed in the stomach by lingual lipase, an enzyme secreted from lingual serous glands. We investigated the substrate specificity of this enzyme as well as the potential of lingual lipase to act in the upper small intestine i.e., in the presence of bile salts and lecithin. The data presented show that partially purified preparations of rat lingual lipase and the lipase in gastric aspirates of newborn infants have identical substrate specificity: medium-chain triglycerides were hydrolyzed at rates 5-8-fold higher than long-chain triglycerides; the rat and human enzymes do not hydrolyze the ester bond of lecithin or cholesteryl-ester. In contrast to pancreatic lipase, the hydrolysis of triglycerides by lingual lipase is not inhibited by lecithin. But, similar to pancreatic lipase the activity of lingual lipase is inhibited by bile salts, the extent of inhibition varying with its nature and concentration. This inactivation is not prevented by colipase but is partially averted by lipids and protein, suggesting that lingual lipase can remain active in the duodenum. The pH optimum of the enzyme (2.2-6.5 in the rat and 3.5-6.0 in human gastric aspirates) is compatible with continued activity in the upper small intestine, especially during the neonatal period, when the luminal pH is under 6.5. The marked variation in lipase activity levels in gastric aspirates of newborn infants is probably due to individual variations in enzyme amounts. The characteristics of the lipase are however identical in infants with low, intermediate or high activity levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Streptococcal serum opacity factor promotes cholesterol ester metabolism and bile acid secretion in vitro and in vivo.

PubMed

Gillard, Baiba K; Rodriguez, Perla J; Fields, David W; Raya, Joe L; Lagor, William R; Rosales, Corina; Courtney, Harry S; Gotto, Antonio M; Pownall, Henry J

2016-03-01

Plasma high density lipoprotein-cholesterol (HDL-C) concentrations negatively correlate with atherosclerotic cardiovascular disease. HDL is thought to have several atheroprotective functions, which are likely distinct from the epidemiological inverse relationship between HDL-C levels and risk. Specifically, strategies that reduce HDL-C while promoting reverse cholesterol transport (RCT) may have therapeutic value. The major product of the serum opacity factor (SOF) reaction versus HDL is a cholesteryl ester (CE)-rich microemulsion (CERM), which contains apo E and the CE of ~400,000 HDL particles. Huh7 hepatocytes take up CE faster when delivered as CERM than as HDL, in part via the LDL-receptor (LDLR). Here we compared the final RCT step, hepatic uptake and subsequent intracellular processing to cholesterol and bile salts for radiolabeled HDL-, CERM- and LDL-CE by Huh7 cells and in vivo in C57BL/6J mice. In Huh7 cells, uptake from LDL was greater than from CERM (2-4X) and HDL (5-10X). Halftimes for [(14)C]CE hydrolysis were 3.0±0.2, 4.4±0.6 and 5.4±0.7h respectively for HDL, CERM and LDL-CE. The fraction of sterols secreted as bile acids was ~50% by 8h for all three particles. HDL, CERM and LDL-CE metabolism in mice showed efficient plasma clearance of CERM-CE, liver uptake and metabolism, and secretion as bile acids into the gall bladder. This work supports the therapeutic potential of the SOF reaction, which diverts HDL-CE to the LDLR, thereby increasing hepatic CE uptake, and sterol disposal as bile acids. Copyright © 2015 Elsevier B.V. All rights reserved.

Streptococcal Serum Opacity Factor Increases Hepatocyte Uptake of Human Plasma High Density Lipoprotein-Cholesterol1

PubMed Central

Gillard, Baiba K.; Rosales, Corina; Pillai, Biju K.; Lin, Hu Yu; Courtney, Harry S.; Pownall, Henry J.

2010-01-01

Serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes, converts plasma high density lipoproteins (HDL) to three distinct species: lipid-free apolipoprotein (apo) A-I, neo HDL, a small discoidal HDL-like particle, and a large cholesteryl ester-rich microemulsion (CERM), that contains the cholesterol esters (CE) of up to ~400,000 HDL particles and apo E as its major protein. Similar SOF reaction products are obtained with HDL, total plasma lipoproteins and whole plasma. We hypothesized that hepatic uptake of CERM-CE via multiple apo E dependent receptors would be faster than that of HDL-CE. We tested our hypothesis using human hepatoma cells and lipoprotein receptor-specific Chinese hamster ovary (CHO) cells. [3H]CE uptake by HepG2 and Huh7 cells from HDL after SOF treatment, which transfers >90% of HDL-CE to CERM, was respectively 2.4 and 4.5 times faster than from control HDL. CERM-[3H]CE uptake was inhibited by LDL and HDL, suggestive of uptake by both the LDL receptor (LDL-R) and scavenger receptor class B type I (SR-BI). Studies in CHO cells specifically expressing LDL-R and SR-BI confirmed CERM-[3H]CE uptake by both receptors. RAP and heparin inhibit CERM-[3H]CE but not HDL-[3H]CE uptake thereby implicating LRP-1 and cell surface proteoglycans in this process. These data demonstrate that SOF treatment of HDL increases CE uptake via multiple hepatic apo E receptors. In so doing, SOF might increase hepatic disposal of plasma cholesterol in a way that is therapeutically useful. PMID:20879789

[Quality assessment of sulfur-fumigated paeoniae alba radix].

PubMed

Wang, Zhao; Chen, Yu-Wu; Wang, Qiong; Sun, Lei; Xu, Wei-Yi; Jin, Hong-Yu; Ma, Shuang-Cheng

2014-08-01

The samples of sulfur-fumigated Paeoniae Alba Radix acquired both by random spot check from domestic market and self-production by the research group in the laboratory were used to evaluate the effects of sulphur fumigation on the quality of Paeoniae Alba Radix by comparing sulfur-fumigated degree and character, the content of paeoniflorin and paeoniflorin sulfurous acid ester, and changes of the fingerprint. We used methods in Chinese Pharmacopeia to evaluate the character of sulfur-fumigated Paeoniae Alba Radix and determinate the content of aulfur-fumigated paeoniflorin. LC-MS method was used to analyze paeoniflorin-converted products. HPLC fingerprint methods were established to evaluate the differences on quality by similarity. Results showed that fumigated Paeoniae Alba Radix became white and its unique fragrance disappeared, along with the production of pungent sour gas. It also had a significant effect on paeoniflorin content. As sulfur smoked degree aggravated, paeoniflorin content decreased subsequently, some of which turned into paeoniflorin sulfurous acid ester, and this change was not reversible. Fingerprint also showed obvious changes. Obviously, sulfur fumigation had severe influence on the quality of Paeoniae Alba Radix, but we can control the quality of the Paeoniae Alba Radix by testing the paeoniflorin sulfurous acid ester content.

Identification of 3-MCPD esters to verify the adulteration of extra virgin olive oil.

PubMed

Hung, Wei-Ching; Peng, Guan-Jhih; Tsai, Wen-Ju; Chang, Mei-Hua; Liao, Chia-Ding; Tseng, Su-Hsiang; Kao, Ya-Min; Wang, Der-Yuan; Cheng, Hwei-Fang

2017-09-01

The adulteration of olive oil is an important issue around the world. This paper reports an indirect method by which to identify 3-monochloropropane-1,2-diol (3-MCPD) esters in olive oils. Following sample preparation, the samples were spiked with 1,2-bis-palmitoyl-3-chloropropanediol standard for analysis using gas chromatograph-tandem mass spectrometry. The total recovery ranged from 102.8% to 105.5%, the coefficient of variation ranged from 1.1% to 10.1%, and the limit of quantification was 0.125 mg/kg. The content of 3-MCPD esters in samples of refined olive oil (0.97-20.53 mg/kg) exceeded those of extra virgin olive oil (non-detected to 0.24 mg/kg). These results indicate that the oil refining process increased the content of 3-MCPD esters, which means that they could be used as a target compound for the differentiation of extra virgin olive oil from refined olive oil in order to prevent adulteration.

Lipophagy Contributes to Testosterone Biosynthesis in Male Rat Leydig Cells.

PubMed

Ma, Yi; Zhou, Yan; Zhu, Yin-Ci; Wang, Si-Qi; Ping, Ping; Chen, Xiang-Feng

2018-02-01

In recent years, autophagy was found to regulate lipid metabolism through a process termed lipophagy. Lipophagy modulates the degradation of cholesteryl esters to free cholesterol (FC), which is the substrate of testosterone biosynthesis. However, the role of lipophagy in testosterone production is unknown. To investigate this, primary rat Leydig cells and varicocele rat models were administered to inhibit or promote autophagy, and testosterone, lipid droplets (LDs), total cholesterol (TC), and FC were evaluated. The results demonstrated that inhibiting autophagy in primary rat Leydig cells reduced testosterone production. Further studies demonstrated that inhibiting autophagy increased the number and size of LDs and the level of TC, but decreased the level of FC. Furthermore, hypoxia promoted autophagy in Leydig cells. We found that short-term hypoxia stimulated testosterone secretion; however, the inhibition of autophagy abolished stimulated testosterone release. Hypoxia decreased the number and size of LDs in Leydig cells, but the changes could be largely rescued by blocking autophagy. In experimental varicocele rat models, the administration of autophagy inhibitors substantially reduced serum testosterone. These data demonstrate that autophagy contributes to testosterone biosynthesis at least partially through degrading intracellular LDs/TC. Our observations might reveal an autophagic regulatory mode regarding testosterone biosynthesis. Copyright © 2018 Endocrine Society.

Alcohol produces distinct hepatic lipidome and eicosanoid signature in lean and obese[S

PubMed Central

Puri, Puneet; Xu, Jun; Vihervaara, Terhi; Katainen, Riikka; Ekroos, Kim; Daita, Kalyani; Min, Hae-Ki; Joyce, Andrew; Mirshahi, Faridoddin; Tsukamoto, Hidekazu; Sanyal, Arun J.

2016-01-01

Alcohol- and obesity-related liver diseases often coexist. The hepatic lipidomics due to alcohol and obesity interaction is unknown. We characterized the hepatic lipidome due to 1) alcohol consumption in lean and obese mice and 2) obesity and alcohol interactions. In the French-Tsukamoto mouse model, intragastric alcohol or isocaloric dextrose were fed with either chow (lean) or high-fat, high-cholesterol diet (obese). Four groups (lean, lean alcohol, obese, and obese alcohol) were studied. MS was performed for hepatic lipidomics, and data were analyzed. Alcohol significantly increased hepatic cholesteryl esters and diacyl­glycerol in lean and obese but was more pronounced in obese. Alcohol produced contrasting changes in hepatic phospholipids with significant enrichment in lean mice versus significant decrease in obese mice, except phosphatidylglycerol, which was increased in both lean and obese alcohol groups. Most lysophospholipids were increased in lean alcohol and obese mice without alcohol use only. Prostaglandin E2; 5-, 8-, and 11-hydroxyeicosatetraenoic acids; and 9- and 13-hydroxyoctadecadienoic acids were considerably increased in obese mice with alcohol use. Alcohol consumption produced distinct changes in lean and obese with profound effects of obesity and alcohol interaction on proinflammatory and oxidative stress-related eicosanoids. PMID:27020313

Metabolism of plasma cholesterol and lipoprotein parameters are related to a higher degree of insulin sensitivity in high HDL-C healthy normal weight subjects.

PubMed

Leança, Camila C; Nunes, Valéria S; Panzoldo, Natália B; Zago, Vanessa S; Parra, Eliane S; Cazita, Patrícia M; Jauhiainen, Matti; Passarelli, Marisa; Nakandakare, Edna R; de Faria, Eliana C; Quintão, Eder C R

2013-11-22

We have searched if plasma high density lipoprotein-cholesterol (HDL-C) concentration interferes simultaneously with whole-body cholesterol metabolism and insulin sensitivity in normal weight healthy adult subjects. We have measured the activities of several plasma components that are critically influenced by insulin and that control lipoprotein metabolism in subjects with low and high HDL-C concentrations. These parameters included cholesteryl ester transfer protein (CETP), phospholipid transfer protein (PLTP), lecithin cholesterol acyl transferase (LCAT), post-heparin lipoprotein lipase (LPL), hepatic lipase (HL), pre-beta-₁HDL, and plasma sterol markers of cholesterol synthesis and intestinal absorption. In the high-HDL-C group, we found lower plasma concentrations of triglycerides, alanine aminotransferase, insulin, HOMA-IR index, activities of LCAT and HL compared with the low HDL-C group; additionally, we found higher activity of LPL and pre-beta-₁HDL concentration in the high-HDL-C group. There were no differences in the plasma CETP and PLTP activities. These findings indicate that in healthy hyperalphalipoproteinemia subjects, several parameters that control the metabolism of plasma cholesterol and lipoproteins are related to a higher degree of insulin sensitivity.

Omega-3 fatty acids promote fatty acid utilization and production of pro-resolving lipid mediators in alternatively activated adipose tissue macrophages.

PubMed

Rombaldova, Martina; Janovska, Petra; Kopecky, Jan; Kuda, Ondrej

2017-08-26

It is becoming increasingly apparent that mutual interactions between adipocytes and immune cells are key to the integrated control of adipose tissue inflammation and lipid metabolism in obesity, but little is known about the non-inflammatory functions of adipose tissue macrophages (ATMs) and how they might be impacted by neighboring adipocytes. In the current study we used metabolipidomic analysis to examine the adaptations to lipid overload of M1 or M2 polarized macrophages co-incubated with adipocytes and explored potential benefits of omega-3 polyunsaturated fatty acids (PUFA). Macrophages adjust their metabolism to process excess lipids and M2 macrophages in turn modulate lipolysis and fatty acids (FA) re-esterification of adipocytes. While M1 macrophages tend to store surplus FA as triacylglycerols and cholesteryl esters in lipid droplets, M2 macrophages channel FA toward re-esterification and β-oxidation. Dietary omega-3 PUFA enhance β-oxidation in both M1 and M2. Our data document that ATMs contribute to lipid trafficking in adipose tissue and that omega-3 PUFA could modulate FA metabolism of ATMs. Copyright © 2017 Elsevier Inc. All rights reserved.

[Residual risk: The roles of triglycerides and high density lipoproteins].

PubMed

Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

2016-06-01

In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. © Georg Thieme Verlag KG Stuttgart · New York.

Saturated fatty acid chain length and positional distribution in infant formula: effects on growth and plasma lipids and ketones in piglets.

PubMed

Innis, S M; Quinlan, P; Diersen-Schade, D

1993-03-01

Human milk contains a large proportion of palmitic acid (16:0) with > 70% esterified to the center sn-2 position of the milk triglyceride. Infant formulas often use 8:0 + 10:0 [medium-chain triglyceride (MCT)] or 12:0 + 14:0 (coconut oil) as the saturated fat. The effect of formula saturated fatty acid composition; 8:0 + 10:0, 12:0 + 14:0, or 16:0 from palm oil or synthesized triglyceride containing predominantly sn-2 16:0 on plasma lipids and fatty acids was studied in piglets. Although the formulas contained similar 18:1 and 18:2n-6, plasma lipid percentages of 18:1 and 18:2n-6 were higher in piglets fed the formula with MCT or coconut oil rather than the formulas with 16:0, or sow milk. The sn-2 16:0 of the synthesized triglyceride had unique properties. Specifically, piglets fed synthesized triglyceride had significantly higher cholesteryl ester 16:0 identical to that in piglets fed sow milk and higher plasma total and high-density-lipoprotein cholesterol than piglets fed the other formulas.

High-temperature gas chromatography-mass spectrometry for skin surface lipids profiling.

PubMed

Michael-Jubeli, Rime; Bleton, Jean; Baillet-Guffroy, Arlette

2011-01-01

Skin surface lipids (SSLs) arising from both sebaceous glands and skin removal form a complex lipid mixture composed of free fatty acids and neutral lipids. High-temperature gas chromatography coupled with electron impact or chemical ionization mass spectrometry was used to achieve a simple analytical protocol, without prior separation in classes and without prior cleavage of lipid molecules, in order to obtain simultaneously i) a qualitative characterization of the individual SSLs and ii) a quantitative evaluation of lipid classes. The method was first optimized with SSLs collected from the forehead of a volunteer. More than 200 compounds were identified in the same run. These compounds have been classified in five lipid classes: free fatty acids, hydrocarbons, waxes, sterols, and glycerides. The advantage to this method was it provided structural information on intact compounds, which is new for cholesteryl esters and glycerides, and to obtain detailed fingerprints of the major SSLs. These fingerprints were used to compare the SSL compositions from different body areas. The squalene/cholesterol ratio was used to determine the balance between sebaceous secretion and skin removal. This method could be of general interest in fields where complex lipid mixtures are involved.

A systematic survey of lipids across mouse tissues

PubMed Central

Jain, Mohit; Ngoy, Soeun; Sheth, Sunil A.; Swanson, Raymond A.; Rhee, Eugene P.; Liao, Ronglih; Clish, Clary B.; Mootha, Vamsi K.

2014-01-01

Lipids are a diverse collection of macromolecules essential for normal physiology, but the tissue distribution and function for many individual lipid species remain unclear. Here, we report a mass spectrometry survey of lipid abundance across 18 mouse tissues, detecting ∼1,000 mass spectrometry features, of which we identify 179 lipids from the glycerolipids, glycerophospholipids, lysophospholipids, acylcarnitines, sphingolipids, and cholesteryl ester classes. Our data reveal tissue-specific organization of lipids and can be used to generate testable hypotheses. For example, our data indicate that circulating triglycerides positively and negatively associated with future diabetes in humans are enriched in mouse adipose tissue and liver, respectively, raising hypotheses regarding the tissue origins of these diabetes-associated lipids. We also integrate our tissue lipid data with gene expression profiles to predict a number of substrates of lipid-metabolizing enzymes, highlighting choline phosphotransferases and sterol O-acyltransferases. Finally, we identify several tissue-specific lipids not present in plasma under normal conditions that may be of interest as biomarkers of tissue injury, and we show that two of these lipids are released into blood following ischemic brain injury in mice. This resource complements existing compendia of tissue gene expression and may be useful for integrative physiology and lipid biology. PMID:24518676

Abnormalities of High Density Lipoproteins in Abetalipoproteinemia*

PubMed Central

Jones, John W.; Ways, Peter

1967-01-01

Detailed studies of the high density lipoproteins from three patients with abetalipoproteinemia have revealed the following principal abnormalities: 1) High density lipoprotein 3 (HDL3) is reduced in both absolute and relative concentration, although HDL2 is present in normal amounts. 2) The phospholipid distribution of both HDL fractions is abnormal, with low concentrations of lecithin and an increased percentage (though normal absolute quantity) of sphingomyelin. 3) In both HDL fractions, lecithin contains less linoleate and more oleate than normal. The cholesteryl esters are also low in linoleic acid, and the sphingomyelin is high in nervonic acid. Dietary intake influences the linoleic acid concentration within 2 weeks, and perhaps sooner, but the elevated sphingomyelin nervonic acid is little affected by up to 6 months of corn oil supplementation. Qualitatively similar changes in fatty acid composition, but not phospholipid distribution, are also found in other malabsorption states. The available evidence suggests that the abnormally low levels of HDL3 and the deranged phospholipid distribution are more specific for abetalipoproteinemia than the fatty acid abnormalities. However, the absence of these abnormalities in obligate heterozygous subjects makes their relationship to the primary defect of abetalipoproteinemia difficult to assess. Images PMID:6027078

Molecular profiling of sepsis in mice using Fourier Transform Infrared Microspectroscopy.

PubMed

Gautam, Rekha; Deobagkar-Lele, Mukta; Majumdar, Shamik; Chandrasekar, Bhagawat; Victor, Emmanuel; Ahmed, Syed Moiz; Wadhwa, Nitin; Verma, Taru; Kumar, Srividya; Sundaresan, Nagalingam Ravi; Umapathy, Siva; Nandi, Dipankar

2016-01-01

Sepsis is a life threatening condition resulting from a high burden of infection. It is a major health care problem and associated with inflammation, organ dysfunction and significant mortality. However, proper understanding and delineating the changes that occur during this complex condition remains a challenge. A comparative study involving intra-peritoneal injection of BALB/c mice with Salmonella Typhimurium (infection), lipopolysaccharide (endotoxic shock) or thioglycollate (sterile peritonitis) was performed. The changes in organs and sera were profiled using immunological assays and Fourier Transform Infrared (FTIR) micro-spectroscopy. There is a rapid rise in inflammatory cytokines accompanied with lowering of temperature, respiratory rate and glucose amounts in mice injected with S. Typhimurium or lipopolysaccharide. FTIR identifies distinct changes in liver and sera: decrease in glycogen and protein/lipid ratio and increase in DNA and cholesteryl esters. These changes were distinct from the pattern observed in mice treated with thioglycollate and the differences in the data obtained between the three models are discussed. The combination of FTIR spectroscopy and other biomarkers will be valuable in monitoring molecular changes during sepsis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multidimensional profiling of plasma lipoproteins by size exclusion chromatography followed by reverse-phase protein arrays

PubMed Central

Dernick, Gregor; Obermüller, Stefan; Mangold, Cyrill; Magg, Christine; Matile, Hugues; Gutmann, Oliver; von der Mark, Elisabeth; Handschin, Corinne; Maugeais, Cyrille; Niesor, Eric J.

2011-01-01

The composition of lipoproteins and the association of proteins with various particles are of much interest in the context of cardiovascular disease. Here, we describe a technique for the multidimensional analysis of lipoproteins and their associated apolipoproteins. Plasma is separated by size exclusion chromatography (SEC), and fractions are analyzed by reverse-phase arrays. SEC fractions are spotted on nitrocellulose slides and incubated with different antibodies against individual apolipoproteins or antibodies against various apolipoproteins. In this way, tens of analytes can be measured simultaneously in 100 μl of plasma from a single SEC separation. This methodology is particularly suited to simultaneous analysis of multiple proteins that may change their distribution to lipoproteins or alter their conformation, depending on factors that influence circulating lipoprotein size or composition. We observed changes in the distribution of exchangeable apolipoproteins following addition of recombinant apolipoproteins or interaction with exogenous compounds. While the cholesteryl ester transfer protein (CETP)-dependent formation of pre-β-HDL was inhibited by the CETP inhibitors torcetrapib and anacetrapib, it was not reduced by the CETP modulator dalcetrapib. This finding was elucidated using this technique. PMID:21971713

Spacer effect on nanostructures and self-assembly in organogels via some bolaform cholesteryl imide derivatives with different spacers

PubMed Central

2013-01-01

In this paper, new bolaform cholesteryl imide derivatives with different spacers were designed and synthesized. Their gelation behaviors in 23 solvents were investigated, and some of them were found to be low molecular mass organic gelators. The experimental results indicated that these as-formed organogels can be regulated by changing the flexible/rigid segments in spacers and organic solvents. Suitable combination of flexible/rigid segments in molecular spacers in the present cholesteryl gelators is favorable for the gelation of organic solvents. Scanning electron microscopy and atomic force microscopy observations revealed that the gelator molecules self-assemble into different aggregates, from wrinkle and belt to fiber with the change of spacers and solvents. Spectral studies indicated that there existed different H-bond formations between imide groups and assembly modes, depending on the substituent spacers in molecular skeletons. The present work may give some insight into the design and character of new organogelators and soft materials with special molecular structures. PMID:24083361

Spacer effect on nanostructures and self-assembly in organogels via some bolaform cholesteryl imide derivatives with different spacers

NASA Astrophysics Data System (ADS)

Jiao, Tifeng; Gao, Fengqing; Zhang, Qingrui; Zhou, Jingxin; Gao, Faming

2013-10-01

In this paper, new bolaform cholesteryl imide derivatives with different spacers were designed and synthesized. Their gelation behaviors in 23 solvents were investigated, and some of them were found to be low molecular mass organic gelators. The experimental results indicated that these as-formed organogels can be regulated by changing the flexible/rigid segments in spacers and organic solvents. Suitable combination of flexible/rigid segments in molecular spacers in the present cholesteryl gelators is favorable for the gelation of organic solvents. Scanning electron microscopy and atomic force microscopy observations revealed that the gelator molecules self-assemble into different aggregates, from wrinkle and belt to fiber with the change of spacers and solvents. Spectral studies indicated that there existed different H-bond formations between imide groups and assembly modes, depending on the substituent spacers in molecular skeletons. The present work may give some insight into the design and character of new organogelators and soft materials with special molecular structures.

40 CFR 180.920 - Inert ingredients used pre-harvest; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium, and zinc salts of the phosphate esters; minimum oxyethylene content is 2 moles.... 14433-76-2) Emulsifier, solvent, cosolvent Diammonium phosphate (CAS Reg. No. 7783-28-0) Buffer...

40 CFR 180.930 - Inert ingredients applied to animals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium and zinc salts of the phosphate esters; minimum oxyethylene content averages 2..., density control agent Benzoic acid Preservative for formulations 2-Bromo-2-nitro-1,3-propanediol (CAS Reg...

40 CFR 180.920 - Inert ingredients used pre-harvest; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium, and zinc salts of the phosphate esters; minimum oxyethylene content is 2 moles... phosphate (CAS Reg. No. 7783-28-0) Buffer, surfactant dibenzylidene sorbitol (32647-67-9) Thinning agent...

40 CFR 180.920 - Inert ingredients used pre-harvest; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium, and zinc salts of the phosphate esters; minimum oxyethylene content is 2 moles... phosphate (CAS Reg. No. 7783-28-0) Buffer, surfactant dibenzylidene sorbitol (32647-67-9) Thinning agent...

Corrosion-Related Consequences of Biodiesel in Contact with Natural Seawater

DTIC Science & Technology

2010-03-01

petroleum diesel, biodiesel contains no sulfur. In the U.S. the term “biodiesel” is standardized as fatty acid methyl ester ( FAME ). Biodiesel content is...Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 to methyl (or ethyl) esters with a process known as transesterification.4 The transesterification...biodegradation of the vegetable methyl esters in agitated San Francisco Bay water was less than 4 days at 17 °C.4,22 The highest corrosion rates

Regulation of Sterol Content in Membranes by Subcellular Compartmentation of Steryl-Esters Accumulating in a Sterol-Overproducing Tobacco Mutant.

PubMed Central

Gondet, L.; Bronner, R.; Benveniste, P.

1994-01-01

The study of sterol overproduction in tissues of LAB 1-4 mutant tobacco (Nicotiana tabacum L. cv Xanthi) (P. Maillot-Vernier, H. Schaller, P. Benveniste, G. Belliard [1989] Biochem Biophys Res Commun 165: 125-130) over several generations showed that the overproduction phenotype is stable in calli, with a 10-fold stimulation of sterol content when compared with wild-type calli. However, leaves of LAB 1-4 plants obtained after two steps of self-fertilization were characterized by a mere 3-fold stimulation, whereas calli obtained from these plants retained a typical sterol-overproducing mutant phenotype (i.e. a 10-fold increase of sterol content). These results suggest that the expression of the LAB 1-4 phenotype is dependent on the differentiation state of cells. Most of the sterols accumulating in the mutant tissues were present as steryl-esters, which were minor species in wild-type tissues. Subcellular fractionation showed that in both mutant and wild-type tissues, free sterols were associated mainly with microsomal membranes. In contrast, the bulk of steryl-esters present in mutant tissues was found in the soluble fraction of cells. Numerous lipid droplets were detected in the hyaloplasm of LAB 1-4 cells by cytochemical and cytological techniques. After isolation, these lipid granules were shown to contain steryl-esters. These results show that the overproduced sterols of mutant tissues accumulate as steryl-esters in hyaloplasmic bodies. The esterification process thus allows regulation of the amount of free sterols in membranes by subcellular compartmentation. PMID:12232218

Butter as a feedstock for biodiesel production.

PubMed

Haas, Michael J; Adawi, Nadia; Berry, William W; Feldman, Elaine; Kasprzyk, Stephen; Ratigan, Brian; Scott, Karen; Landsburg, Emily Bockian

2010-07-14

Fatty acid methyl esters (FAME) were produced from cow's milk (Bostaurus) butter by esterification/transesterification in the presence of methanol. The product was assayed according to the Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels (ASTM D 6751). The preparation failed to meet the specifications for flash point, free and total glycerin contents, total sulfur, and oxidation stability. Failures to meet the flash point and free/total glycerin specifications were determined to be due to interference with standard assays for these parameters by short-chain-length fatty acid esters. The oxidation stability of the butterfat FAME was improved by supplementation with a commercial antioxidant formulation. Approximately 725 ppm of antioxidant was required to meet the ASTM-specified stability value for biodiesel. This work indicates that, without further purification to reduce a slightly excessive sulfur content, fatty acid ester preparations produced from butter are unacceptable as sole components of a biodiesel fuel. However, it is possible that even without further purification a butter-based ester preparation could be mixed with biodiesel from other feedstocks to produce a blend that meets the current quality standards for biodiesel. The results presented here also illustrate some potential weaknesses in the accepted methods for biodiesel characterization when employed in the analysis of FAME preparations containing mid- and short-chain fatty acid esters.

Effect of reaction temperature on biodiesel production from waste cooking oil using lipase as biocatalyst

NASA Astrophysics Data System (ADS)

Istiningrum, Reni Banowati; Aprianto, Toni; Pamungkas, Febria Lutfi Udin

2017-12-01

This study aims to determine the effect of temperature on conversion of biodiesel from waste cooking oil enzymatically using lipase extracted from rice bran. The feedstock was simulated waste cooking oil and lipase enzyme was extracted with buffer pH variation. The enzyme activity was titrimetrically determined and the optimum pH buffer was used to study the effect of temperature on the transesterification reaction. Temperature effects were assessed in the range of 45-60 °C and the content of methyl esters in biodiesel was determined by GC-MS. The reaction temperature significantly influences the transesterification reaction with optimum biodiesel conversion occurred at 55 °C with methyl ester content of 81.19%. The methyl ester composition in the resulting biodiesel is methyl palmitate, methyl oleate and methyl stearate.

Impact of thermooxidation of phytosteryl and phytostanyl fatty acid esters on cholesterol micellarization in vitro.

PubMed

Scholz, Birgit; Weiherer, Renate; Engel, Karl-Heinz

2017-09-01

The effects of thermooxidation of a phytosteryl/-stanyl and a phytostanyl fatty acid ester mixture on cholesterol micellarization were investigated using an in vitro digestion model simulating enzymatic hydrolysis by cholesterol esterase and subsequent competition of the liberated phytosterols/-stanols with cholesterol for incorporation into mixed micelles. As a first step, relationships between different doses of the ester mixtures and the resulting micellarized cholesterol were established. Subsequent subjection of the thermooxidized ester mixtures to the in vitro digestion model resulted in three principal observations: (i) thermal treatment of the ester mixtures led to substantial decreases of the intact esters, (ii) in vitro digestion of cholesterol in the presence of the thermooxidized ester mixtures resulted in significant increases of cholesterol micellarization, and (iii) the extents of the observed effects on cholesterol micellarization were strongly associated to the remaining contents of intact esters. The loss of efficacy to inhibit cholesterol micellarization due to thermally induced losses of intact esters corresponded to a loss of efficacy that would have been induced by an actual removal of these amounts of esters prior to the in vitro digestion. The obtained results suggest that in particular oxidative modifications of the fatty acid moieties might be responsible for the observed increases of cholesterol micellarization. Copyright © 2017 Elsevier Inc. All rights reserved.

Preparation of fatty acid methyl esters from Osage orange (Maclura pomifera) oil and evaluation as biodiesel

USDA-ARS?s Scientific Manuscript database

Fatty acid methyl esters were prepared in high yield by transesterification of Osage orange (Maclura pomifera) oil. Extracted using supercritical CO2, the crude oil was initially treated with mineral acid and methanol to lower its content of free fatty acids, thus rendering it amenable to homogeneou...

Synthesis and biological evaluation of new creatine fatty esters revealed dodecyl creatine ester as a promising drug candidate for the treatment of the creatine transporter deficiency.

PubMed

Trotier-Faurion, Alexandra; Dézard, Sophie; Taran, Frédéric; Valayannopoulos, Vassili; de Lonlay, Pascale; Mabondzo, Aloïse

2013-06-27

The creatine transporter deficiency is a neurological disease caused by impairment of the creatine transporter SLC6A8, resulting in mental retardation associated with a complete absence of creatine within the brain and cellular energy perturbation of neuronal cells. One of the therapeutic hypotheses was to administer lipophilic creatine derivatives which are (1) thought to have better permeability through the cell membrane and (2) would not rely on the activity of SLC6A8 to penetrate the brain. Here, we synthesized creatine fatty esters through original organic chemistry process. A screening on an in vitro rat primary cell-based blood-brain barrier model and on a rat primary neuronal cells model demonstrated interesting properties of these prodrugs to incorporate into endothelial, astroglial, and neuronal cells according to a structure-activity relationship. Dodecyl creatine ester showed then a 20-fold increase in creatine content in pathological human fibroblasts compared with the endogenous creatine content, stating that it could be a promising drug candidate.

Separation and determination of secoisolariciresinol diglucoside oligomers and their hydrolysates in the flaxseed extract by high-performance liquid chromatography.

PubMed

Li, Xin; Yuan, Jian-Ping; Xu, Shi-Ping; Wang, Jiang-Hai; Liu, Xin

2008-03-28

Flaxseed contains the largest amount of lignan secoisolariciresinol diglucoside (SDG) oligomers and is the richest dietary source of SDG. SDG oligomers in the flaxseed extract are often hydrolyzed to break the ester linkages for the release of SDG and the glycosidic bonds for the release of secoisolariciresinol (SECO). The hydrolysates of SDG oligomers are complicated because of the production of esters in an alcohol-containing medium. In this study, a new gradient reversed-phase high-performance liquid chromatography (HPLC) method has been developed to be suitable for the separation and determination of: (1) SDG oligomers extracted from the defatted flaxseed powder by a 70% aqueous methanol solution; (2) SDG oligomers and their alkaline hydrolysates, including SDG, p-coumaric acid glucoside and its methyl ester, ferulic acid glucoside and its methyl ester in an alkaline hydrolytic solution; and (3) the succedent acid hydrolysates, including secoisolariciresinol monoglucoside (SMG), SECO, anhydrosecoisolariciresinol (anhydro-SECO), p-coumaric acid and its methyl ester, ferulic acid and its methyl ester, 5-hydroxymethyl-2-furfural (HMF) and its degradation product in an acid hydrolytic solution. The content of SDG oligomers in a defatted flaxseed powder was found to be 38.5 mg/g on a dry matter basis, corresponding to a SDG content of 15.4 mg/g, which was determined after alkaline hydrolysis. Furthermore, this study presented a major reaction pathway for the hydrolysis of SDG oligomers.

Peroxisome proliferator-activated receptor ligands regulate lipid content, metabolism, and composition in fetal lungs of diabetic rats.

PubMed

Kurtz, M; Capobianco, E; Careaga, V; Martinez, N; Mazzucco, M B; Maier, M; Jawerbaum, A

2014-03-01

Maternal diabetes impairs fetal lung development. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors relevant in lipid homeostasis and lung development. This study aims to evaluate the effect of in vivo activation of PPARs on lipid homeostasis in fetal lungs of diabetic rats. To this end, we studied lipid concentrations, expression of lipid metabolizing enzymes and fatty acid composition in fetal lungs of control and diabetic rats i) after injections of the fetuses with Leukotriene B4 (LTB4, PPARα ligand) or 15deoxyΔ(12,14)prostaglandin J2 (15dPGJ2, PPARγ ligand) and ii) fed during pregnancy with 6% olive oil- or 6% safflower oil-supplemented diets, enriched with PPAR ligands were studied. Maternal diabetes increased triglyceride concentrations and decreased expression of lipid-oxidizing enzymes in fetal lungs of diabetic rats, an expression further decreased by LTB4 and partially restored by 15dPGJ2 in lungs of male fetuses in the diabetic group. In lungs of female fetuses in the diabetic group, maternal diets enriched with olive oil increased triglyceride concentrations and fatty acid synthase expression, while those enriched with safflower oil increased triglyceride concentrations and fatty acid transporter expression. Both olive oil- and safflower oil-supplemented diets decreased cholesterol and cholesteryl ester concentrations and increased the expression of the reverse cholesterol transporter ATP-binding cassette A1 in fetal lungs of female fetuses of diabetic rats. In fetal lungs of control and diabetic rats, the proportion of polyunsaturated fatty acids increased with the maternal diets enriched with olive and safflower oils. Our results revealed important changes in lipid metabolism in fetal lungs of diabetic rats, and in the ability of PPAR ligands to modulate the composition of lipid species relevant in the lung during the perinatal period.

Phospholipase A2-treated human high-density lipoprotein and cholesterol movements: exchange processes and lecithin: cholesterol acyltransferase reactivity.

PubMed

Chollet, F; Perret, B P; Chap, H; Douste-Blazy, L

1986-02-12

Human HDL3 (d 1.125-1.21 g/ml) were treated by an exogenous phospholipase A2 from Crotalus adamenteus in the presence of albumin. Phosphatidylcholine hydrolysis ranged between 30 and 90% and the reisolated particle was essentially devoid of lipolysis products. (1) An exchange of free cholesterol was recorded between radiolabelled erythrocytes at 5-10% haematocrit and HDL3 (0.6 mM total cholesterol) from 0 to 12-15 h. Isotopic equilibration was reached. Kinetic analysis of the data indicated a constant rate of free cholesterol exchange of 13.0 microM/h with a half-time of equilibration around 3 h. Very similar values of cholesterol exchange, specific radioactivities and kinetic parameters were measured when phospholipase-treated HDL replaced control HDL. (2) The lecithin: cholesterol acyltransferase reactivity of HDL3, containing different amounts of phosphatidylcholine, as achieved by various degrees of phospholipase A2 treatment, was measured using a crude preparation of lecithin: cholesterol acyltransferase (the d 1.21-1.25 g/ml plasma fraction). The rate of esterification was determined between 0 and 12 h. Following a 15-30% lipolysis, the lecithin: cholesterol acyltransferase reactivity of HDL3 was reduced about 30-40%, and then continued to decrease, though more slowly, as the phospholipid content was further lowered in the particle. (3) The addition of the lecithin: cholesterol acyltransferase preparation into an incubation medium made of labelled erythrocytes and HDL3 promoted a movement of radioactive cholesterol out of cells, above the values of exchange, and an accumulation of cholesteryl esters in HDL. This reflected a mass consumption of free cholesterol, from both the cellular and the lipoprotein compartments upon the lecithin: cholesterol acyltransferase action. As a consequence of a decreased reactivity, phospholipase-treated HDL (with 2/3 of phosphatidylcholine hydrolyzed) proved much less effective in the lecithin: cholesterol acyltransferase-induced removal of cellular cholesterol.

Oxidative stress, HDL functionality and effects of intravenous iron administration in women with iron deficiency anemia.

PubMed

Meroño, Tomás; Dauteuille, Carolane; Tetzlaff, Walter; Martín, Maximiliano; Botta, Eliana; Lhomme, Marie; Saez, María Soledad; Sorroche, Patricia; Boero, Laura; Arbelbide, Jorge; Chapman, M John; Kontush, Anatol; Brites, Fernando

2017-04-01

Iron deficiency anemia (IDA) affects around 20-30% of adults worldwide. An association between IDA and cardiovascular disease (CVD) has been reported. Oxidative stress, inflammation and low concentration of high-density lipoproteins (HDL) were implicated on endothelial dysfunction and CVD in IDA. We studied the effects of iron deficiency and of an intravenous iron administration on oxidative stress and HDL characteristics in IDA women. Two studies in IDA women are presented: a case-control study, including 18 patients and 18 age-matched healthy women, and a follow-up study 72hr after the administration of intravenous iron (n = 16). Lipids, malondialdehyde, cholesteryl ester transfer protein (CETP), paraoxonase-1 (PON-1) and HDL chemical composition and functionality (cholesterol efflux and antioxidative activity) were measured. Cell cholesterol efflux from iron-deficient macrophages to a reference HDL was also evaluated. IDA patients showed higher triglycerides and CETP activity and lower HDL-C than controls (all p < 0.001). HDL particles from IDA patients showed higher triglyceride content (+30%,p < 0.05) and lower antioxidative capacity (-23%,p < 0.05). Although HDL-mediated cholesterol efflux was similar between the patients and controls, iron deficiency provoked a significant reduction in macrophage cholesterol efflux (-25%,p < 0.05). Arylesterase activity of PON-1 was significantly lower in IDA patients than controls (-16%,p < 0.05). The intravenous administration of iron was associated with a decrease in malondialdehyde levels and an increase in arylesterase activity of PON-1 (-22% and +18%, respectively, p < 0.05). IDA is associated with oxidative stress and functionally deficient HDL particles. It remains to be determined if such alterations suffice to impair endothelial function in IDA. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Genotypic differences in Al resistance and the role of cell-wall pectin in Al exclusion from the root apex in Fagopyrum tataricum

PubMed Central

Yang, Jian Li; Zhu, Xiao Fang; Zheng, Cheng; Zhang, Yue Jiao; Zheng, Shao Jian

2011-01-01

Background and Aims Aluminium (Al) toxicity is one of the factors limiting crop production on acid soils. However, genotypic differences exist among plant species or cultivars in response to Al toxicity. This study aims to investigate genotypic differences among eight cultivars of tatary buckwheat (Fagopyrum tataricum) for Al resistance and explore the possible mechanisms of Al resistance. Methods Al resistance was evaluated based on relative root elongation (root elongation with Al/root elongation without Al). Root apex Al content, pectin content and exudation of root organic acids were determined and compared. Key Results Genotypic differences among the eight cultivars were correlated with exclusion of Al from the root apex. However, there was a lack of correlation between Al exclusion and Al-induced oxalate secretion. Interestingly, cell-wall pectin content of the root apex was generally lower in Al-resistant cultivars than in Al-sensitive cultivars. Although we were unable to establish a significant correlation between Al exclusion and pectin content among the eight cultivars, a strong correlation could be established among six cultivars, in which the pectin content in the most Al-resistant cultivar ‘Chuan’ was significantly lower than that in the most Al-sensitive cultivar ‘Liuku2’. Furthermore, root apex cell-wall pectin methylesterase activity (PME) was similar in ‘Chuan’ and ‘Liuku2’ in the absence of Al, but Al treatment resulted in increased PME activity in ‘Liuku2’ compared with ‘Chuan’. Immunolocalization of pectins also showed that the two cultivars had similar amounts of either low-methyl-ester pectins or high-methyl-ester pectins in the absence of Al, but Al treatment resulted in a more significant increase of low-methyl-ester pectins and decrease of high-methyl-ester pectins in ‘Liuku2’. Conclusions Cell-wall pectin content may contribute, at least in part, to differential Al resistance among tatary buckwheat cultivars. PMID:21183454

Selected physical properties of various diesel blends

NASA Astrophysics Data System (ADS)

Hlaváčová, Zuzana; Božiková, Monika; Hlaváč, Peter; Regrut, Tomáš; Ardonová, Veronika

2018-01-01

The quality determination of biofuels requires identifying the chemical and physical parameters. The key physical parameters are rheological, thermal and electrical properties. In our study, we investigated samples of diesel blends with rape-seed methyl esters content in the range from 3 to 100%. In these, we measured basic thermophysical properties, including thermal conductivity and thermal diffusivity, using two different transient methods - the hot-wire method and the dynamic plane source. Every thermophysical parameter was measured 100 times using both methods for all samples. Dynamic viscosity was measured during the heating process under the temperature range 20-80°C. A digital rotational viscometer (Brookfield DV 2T) was used for dynamic viscosity detection. Electrical conductivity was measured using digital conductivity meter (Model 1152) in a temperature range from -5 to 30°C. The highest values of thermal parameters were reached in the diesel sample with the highest biofuel content. The dynamic viscosity of samples increased with higher concentration of bio-component rapeseed methyl esters. The electrical conductivity of blends also increased with rapeseed methyl esters content.

Simultaneous analysis of free phytosterols/phytostanols and intact phytosteryl/phytostanyl fatty acid and phenolic acid esters in cereals.

PubMed

Esche, Rebecca; Barnsteiner, Andreas; Scholz, Birgit; Engel, Karl-Heinz

2012-05-30

An approach based on solid-phase extraction for the effective separation of free phytosterols/phytostanols and phytosteryl/phytostanyl fatty acid and phenolic acid esters from cereal lipids was developed. The ester conjugates were analyzed in their intact form by means of capillary gas chromatography. Besides free sterols and stanols, up to 33 different fatty acid and phenolic acid esters were identified in four different cereal grains via gas chromatography-mass spectrometry. The majority (52-57%) of the sterols and stanols were present as fatty acid esters. The highest levels of all three sterol and stanol classes based on dry matter of ground kernels were determined in corn, whereas the oil extract of rye was 1.7 and 1.6 times richer in fatty acid esters and free sterols/stanols than the corn oil. The results showed that there are considerable differences in the sterols/stanols and their ester profiles and contents obtained from corn compared to rye, wheat, and spelt. The proposed method is useful for the quantification of a wide range of free phytosterols/phytostanols and intact phytosteryl/phytostanyl esters to characterize different types of grain.

Screening of adjunct cultures and their application in ester formation in Camembert-type cheese.

PubMed

Hong, Q; Liu, X M; Hang, F; Zhao, J X; Zhang, H; Chen, W

2018-04-01

The ethanol content and esterase and alcohol acyltransferase activities are the limiting factors in the synthesis of ethyl esters in Camembert-type cheeses. This study aimed to investigate the effects of alcohol, esterase and alcohol acyltransferase activities on ethyl ester formation in Camembert-type cheeses. Five experimental cheeses were prepared with three adjunct cultures with different enzyme activities and two levels of ethanol content (400 or 800 μg/g). The cheeses were aged for 4 weeks and analysed weekly for basic physicochemical, textural, volatile and sensory properties. The results showed that both the enzyme activity and ethanol content were limiting factors in the synthesis of ethyl esters in the Camembert-type cheeses. Variation in the esterase synthesis activity was observed among lactic acid bacteria, and the starter culture Lactococcus lactis MA 14 LYO distinguished itself through its high acidifying and esterase hydrolysis abilities. The addition of CCFM 12, a lactic acid bacteria strain with high esterase and alcohol acyltransferase activity, along with 400 or 800 μg/g of ethanol, notably enhanced the generation of ethyl esters and the corresponding fruity flavour, without causing dramatic changes in the basic physicochemical indices and microbial profile. In addition, cohesiveness was influenced by the addition of 400 and 800 μg/g of ethanol, and more resilience with 800 μg/g of ethanol had been found. The results showed that the addition of CCFM12 with 400 and 800 μg/g of ethanol may be applied in the production of Camembert cheese to enhance its fruity flavour. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation of Chemicals and Bulk Drug Substances for the U.S. Army Drug Development Program.

DTIC Science & Technology

1997-12-01

4(R)-rio (,) -dihydroartemisininoxy]-; artemisinin ; dihydroartemisinin; artelinic acid, methyl ester; artelinic acid. -I- TABLE OF CONTENTS I...acid, 4-(4-chloro- phenyl) -4(R) -[10(P) -dihydro- artemisininoxy]-......................... 49 10. Artemisinin ................................. 58 11...dihydroartemisininoxy]-; artemisinin ; dihydroartemisinin; artelinic acid, methyl ester; artelinic acid. -V- II FOREWORD opinions, interpretations, conclusions and

Nanoporous Polymer Films of Cyanate Ester Resins Designed by Using Ionic Liquids as Porogens.

PubMed

Fainleib, Alexander; Vashchuk, Alina; Starostenko, Olga; Grigoryeva, Olga; Rogalsky, Sergiy; Nguyen, Thi-Thanh-Tam; Grande, Daniel

2017-12-01

Novel nanoporous film materials of thermostable cyanate ester resins (CERs) were generated by polycyclotrimerization of dicyanate ester of bisphenol E in the presence of varying amounts (from 20 to 40 wt%) of an ionic liquid (IL), i.e., 1-heptylpyridinium tetrafluoroborate, followed by its quantitative extraction after complete CER network formation. The completion of CER formation and IL extraction was assessed using gel fraction content determination, FTIR, 1 H NMR, and energy-dispersive X-ray spectroscopy (EDX). SEM and DSC-based thermoporometry analyses demonstrated the formation of nanoporous structures after IL removal from CER networks, thus showing the effective role of IL as a porogen. Pore sizes varied from ~20 to ~180 nm with an average pore diameter of around 45-60 nm depending on the initial IL content. The thermal stability of nanoporous CER-based films was investigated by thermogravimetric analysis.

Nanoporous Polymer Films of Cyanate Ester Resins Designed by Using Ionic Liquids as Porogens

NASA Astrophysics Data System (ADS)

Fainleib, Alexander; Vashchuk, Alina; Starostenko, Olga; Grigoryeva, Olga; Rogalsky, Sergiy; Nguyen, Thi-Thanh-Tam; Grande, Daniel

2017-02-01

Novel nanoporous film materials of thermostable cyanate ester resins (CERs) were generated by polycyclotrimerization of dicyanate ester of bisphenol E in the presence of varying amounts (from 20 to 40 wt%) of an ionic liquid (IL), i.e., 1-heptylpyridinium tetrafluoroborate, followed by its quantitative extraction after complete CER network formation. The completion of CER formation and IL extraction was assessed using gel fraction content determination, FTIR, 1H NMR, and energy-dispersive X-ray spectroscopy (EDX). SEM and DSC-based thermoporometry analyses demonstrated the formation of nanoporous structures after IL removal from CER networks, thus showing the effective role of IL as a porogen. Pore sizes varied from 20 to 180 nm with an average pore diameter of around 45-60 nm depending on the initial IL content. The thermal stability of nanoporous CER-based films was investigated by thermogravimetric analysis.

The effects of physical refining on the formation of 3-monochloropropane-1,2-diol esters in relation to palm oil minor components.

PubMed

Zulkurnain, Musfirah; Lai, Oi Ming; Latip, Razam Abdul; Nehdi, Imededdine Arbi; Ling, Tau Chuan; Tan, Chin Ping

2012-11-15

The formation of 3-monochloropropane-1,2-diol (3-MCPD) esters in refined palm oil during deodorisation is attributed to the intrinsic composition of crude palm oil. Utilising D-optimal design, the effects of the degumming and bleaching processes on the reduction in 3-MCPD ester formation in refined palm oil from poor-quality crude palm oil were studied relative to the palm oil minor components that are likely to be their precursors. Water degumming remarkably reduced 3-MCPD ester formation by up to 84%, from 9.79 mg/kg to 1.55 mg/kg. Bleaching with synthetic magnesium silicate caused a further 10% reduction, to 0.487 mg/kg. The reduction in 3-MCPD ester formation could be due to the removal of related precursors prior to the deodorisation step. The phosphorus content of bleached palm oil showed a significant correlation with 3-MCPD ester formation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Production of higher quality bio-oils by in-line esterification of pyrolysis vapor

DOEpatents

Hilten, Roger Norris; Das, Keshav; Kastner, James R; Bibens, Brian P

2014-12-02

The disclosure encompasses in-line reactive condensation processes via vapor phase esterification of bio-oil to decease reactive species concentration and water content in the oily phase of a two-phase oil, thereby increasing storage stability and heating value. Esterification of the bio-oil vapor occurs via the vapor phase contact and subsequent reaction of organic acids with ethanol during condensation results in the production of water and esters. The pyrolysis oil product can have an increased ester content and an increased stability when compared to a condensed pyrolysis oil product not treated with an atomized alcohol.

Effects of Fiber Finish on Mechanical, Low and High Speed Impact of Glass Fiber Reinforced Composites

DTIC Science & Technology

2011-05-12

For 70 Min Cool Down And De-mold 10Unclassified For Producing Polyester Or Vinyl Ester Composite Specimens Resin Resin Inlet Vacuum Bag Trap Pump Steel...Reinforcement Finish Matrix Fiber Content (%) Hexcel 1581-F12 Heat Burnt (No Finish) PP 71.0 Polyester 70.0 Vinyl ester 66.2 Hexcel 1581-GR Greige ( Starch

Alcohol consumption stimulates early steps in reverse cholesterol transport.

PubMed

van der Gaag, M S; van Tol, A; Vermunt, S H; Scheek, L M; Schaafsma, G; Hendriks, H F

2001-12-01

Alcohol consumption is associated with increased HDL cholesterol levels, which may indicate stimulated reverse cholesterol transport. The mechanism is, however, not known. The aim of this study was to evaluate the effects of alcohol consumption on the first two steps of the reverse cholesterol pathway: cellular cholesterol efflux and plasma cholesterol esterification. Eleven healthy middle-aged men consumed four glasses (40 g of alcohol) of red wine, beer, spirits (Dutch gin), or carbonated mineral water (control) daily with evening dinner, for 3 weeks, according to a 4 x 4 Latin square design. After 3 weeks of alcohol consumption the plasma ex vivo cholesterol efflux capacity, measured with Fu5AH cells, was raised by 6.2% (P < 0.0001) and did not differ between the alcoholic beverages. Plasma cholesterol esterification was increased by 10.8% after alcohol (P = 0.008). Changes were statistically significant after beer and spirits, but not after red wine consumption (P = 0.16). HDL lipids changed after alcohol consumption; HDL total cholesterol, HDL cholesteryl ester, HDL free cholesterol, HDL phospholipids and plasma apolipoprotein A-I all increased (P < 0.01). In conclusion, alcohol consumption stimulates cellular cholesterol efflux and its esterification in plasma. These effects were mostly independent of the kind of alcoholic beverage

Novel variants in human and monkey CETP.

PubMed

Lloyd, David B; Reynolds, Jennifer M; Cronan, Melissa T; Williams, Suzanne P; Lira, Maruja E; Wood, Linda S; Knight, Delvin R; Thompson, John F

2005-10-15

Variation in CETP has been shown to play an important role in HDL-C levels and cardiovascular disease. To better characterize this variation, the promoter and exonic DNA for CETP was resequenced in 189 individuals with extreme HDL-C or age. Two novel amino acid variants were found in humans (V-12D and Y361C) and an additional variant (R137W) not previously studied in vitro were expressed. D-12 was not secreted and had no detectable activity in cells. C361 and W137 retained near normal amounts of cholesteryl ester transfer activity when purified but were less well secreted than wild type. Torcetrapib, a CETP inhibitor in clinical development with atorvastatin, was found to have a uniform effect on inhibition of wild type CETP versus W137 or C361. In addition, the level of variation in other species was assessed by resequencing DNA from nine cynomolgus monkeys. Numerous intronic and silent SNPs were found as well as two variable amino acids. The amino acid altering SNPs were genotyped in 29 monkeys and not found to be significantly associated with HDL-C levels. Three SNPs found in monkeys were identical to three found in humans with these SNPs all occurring at CpG sites.

The High-Density Lipoprotein Puzzle: Why Classic Epidemiology, Genetic Epidemiology, and Clinical Trials Conflict?

PubMed

Rosenson, Robert S

2016-05-01

Classical epidemiology has established the incremental contribution of the high-density lipoprotein (HDL) cholesterol measure in the assessment of atherosclerotic cardiovascular disease risk; yet, genetic epidemiology does not support a causal relationship between HDL cholesterol and the future risk of myocardial infarction. Therapeutic interventions directed toward cholesterol loading of the HDL particle have been based on epidemiological studies that have established HDL cholesterol as a biomarker of atherosclerotic cardiovascular risk. However, therapeutic interventions such as niacin, cholesteryl ester transfer protein inhibitors increase HDL cholesterol in patients treated with statins, but have repeatedly failed to reduce cardiovascular events. Statin therapy interferes with ATP-binding cassette transporter-mediated macrophage cholesterol efflux via miR33 and thus may diminish certain HDL functional properties. Unraveling the HDL puzzle will require continued technical advances in the characterization and quantification of multiple HDL subclasses and their functional properties. Key mechanistic criteria for clinical outcomes trials with HDL-based therapies include formation of HDL subclasses that improve the efficiency of macrophage cholesterol efflux and compositional changes in the proteome and lipidome of the HDL particle that are associated with improved antioxidant and anti-inflammatory properties. These measures require validation in genetic studies and clinical trials of HDL-based therapies on the background of statins. © 2016 American Heart Association, Inc.

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

PubMed Central

Chatgilialoglu, Chryssostomos; Ferreri, Carla; Masi, Annalisa; Melchiorre, Michele; Sansone, Anna; Terzidis, Michael A.; Torreggiani, Armida

2013-01-01

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions. PMID:23629513

Modulation of HepG2 cell net apolipoprotein B secretion by the citrus polymethoxyflavone, tangeretin.

PubMed

Kurowska, Elzbieta M; Manthey, John A; Casaschi, Adele; Theriault, Andre G

2004-02-01

The purpose of the present study was to examine the role of tangeretin, a polymethoxylated flavone from citrus fruits, on the regulation of apolipoprotein B (apoB) and lipid metabolism in the human hepatoma cell-line HepG2. The marked reduction in apoB secretion observed in cells incubated with 72.8 microM tangeretin was rapid, apoB-specific, and partly reversible. The reduction also was observed under lipid-rich conditions and found to be insensitive to proteasomal degradation of nascent apoB. We followed our study by examining lipid synthesis and mass. A 24-h exposure of cells to 72.8 microM tangeretin decreased intracellular synthesis of cholesteryl esters, free cholesterol, and TAG by 82, 45, and 64%, respectively; tangeretin also reduced the mass of cellular TAG by 37%. The tangeretin-induced suppression of TAG synthesis and mass were associated with decreased activities of DAG acyltransferase (up to -39.0 +/- 3.0% vs. control) and microsomal triglyceride transfer protein (up to -35.5 +/- 2.5% vs. control). Tangeretin was also found to activate the peroxisome proliferator-activated receptor, a transcription factor with a positive regulatory impact on FA oxidation and TAG availability (up to 36% increase vs. control). The data suggest that tangeretin modulates apoB-containing lipoprotein metabolism through multiple mechanisms.

Alcohol produces distinct hepatic lipidome and eicosanoid signature in lean and obese.

PubMed

Puri, Puneet; Xu, Jun; Vihervaara, Terhi; Katainen, Riikka; Ekroos, Kim; Daita, Kalyani; Min, Hae-Ki; Joyce, Andrew; Mirshahi, Faridoddin; Tsukamoto, Hidekazu; Sanyal, Arun J

2016-06-01

Alcohol- and obesity-related liver diseases often coexist. The hepatic lipidomics due to alcohol and obesity interaction is unknown. We characterized the hepatic lipidome due to 1) alcohol consumption in lean and obese mice and 2) obesity and alcohol interactions. In the French-Tsukamoto mouse model, intragastric alcohol or isocaloric dextrose were fed with either chow (lean) or high-fat, high-cholesterol diet (obese). Four groups (lean, lean alcohol, obese, and obese alcohol) were studied. MS was performed for hepatic lipidomics, and data were analyzed. Alcohol significantly increased hepatic cholesteryl esters and diacyl-glycerol in lean and obese but was more pronounced in obese. Alcohol produced contrasting changes in hepatic phospholipids with significant enrichment in lean mice versus significant decrease in obese mice, except phosphatidylglycerol, which was increased in both lean and obese alcohol groups. Most lysophospholipids were increased in lean alcohol and obese mice without alcohol use only. Prostaglandin E2; 5-, 8-, and 11-hydroxyeicosatetraenoic acids; and 9- and 13-hydroxyoctadecadienoic acids were considerably increased in obese mice with alcohol use. Alcohol consumption produced distinct changes in lean and obese with profound effects of obesity and alcohol interaction on proinflammatory and oxidative stress-related eicosanoids. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Analysis of human serum lipoprotein lipid composition using MALDI-TOF mass spectrometry.

PubMed

Hidaka, Hiroya; Hanyu, Noboru; Sugano, Mitsutoshi; Kawasaki, Kenji; Yamauchi, Kazuyoshi; Katsuyama, Tsutomu

2007-01-01

This study used matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify all lipid classes in human serum lipoproteins. After the major lipoproteins classes were isolated from serum by ultracentrifugation, the lipids were extracted and mixed with 2,5-dihydroxybenzoic acid (2,5-DHB) dissolved in Folch's solution (chloroform/methanol 2:1, v/v). MALDI-TOF MS analysis of the samples identified phospholipids (PLs), lysophospholipids (lysoPLs), sphingolipids (SLs), triglycerides (TGs), cholesteryl esters (CEs), and free cholesterol; it also showed the characteristics of individual fatty acid chains in serum lipids. MALDI-TOF MS allowed analysis of strongly hydrophobic and non-polar molecules such as CEs and TGs as well as hydrophilic molecules such as phospholipids. Direct analysis of fatty acids was not possible. The concentrations of lipids were not consistent with the ion peak intensities, since the extent of polarity affected the ionization characteristics of the molecules. However, lipid molecules with similar molecular structures but various fatty acid chains, such as phosphatidylcholine (PCs), were analyzed quantitatively by MALDI-TOF MS. Quantitative measurement of cholesterol was possible with the use of an internal standard. This study shows that MALDI-TOF MS can be used for direct investigation and quantitative analysis of the phospholipid composition of serum lipoproteins.

Pharmacokinetics and Pharmacodynamics of Anacetrapib Following Single Doses in Healthy, Young Japanese and White Male Subjects.

PubMed

Krishna, Rajesh; Gheyas, Ferdous; Liu, Yang; Cote, Josee; Laterza, Omar; Ruckle, Jon L; Wagner, John A; Denker, Andrew E

2018-02-01

Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor being developed for the treatment of mixed dyslipidemia. The aim of the study was to evaluate the pharmacokinetic, pharmacodynamic, and safety characteristics of anacetrapib following single doses in healthy, young Japanese men. In a double-blind, randomized, placebo-controlled, 3-panel, single-rising-dose study, 6 healthy young Japanese male or white male subjects (aged 19 to 44 years) received single oral doses of 5 to 500 mg anacetrapib, and 2 received placebo. Plasma and urine drug concentrations were measured 0-168 hours postdose, and plasma CETP inhibition was measured 0-24 hours postdose. Urinary anacetrapib levels were all below quantitation limits. Plasma concentrations of anacetrapib increased approximately less than dose-proportionally. Consumption of a traditional Japanese breakfast prior to dosing increased the plasma pharmacokinetics of anacetrapib in Japanese subjects compared with fasted conditions, to a similar extent as in white subjects. CETP activity measured over 0-24 hours postdose resulted in significant inhibition. Anacetrapib was generally well tolerated, and there were no serious adverse experiences. No clinically meaningful differences in PK and CETP inhibition parameters were found between Japanese and white subjects. © 2017, The American College of Clinical Pharmacology.

Effect of dietary fat source on lipoprotein composition and plasma lipid concentrations in pigs.

PubMed

Faidley, T D; Luhman, C M; Galloway, S T; Foley, M K; Beitz, D C

1990-10-01

Most studies of the effects of dietary fat sources on plasma lipid components have used diets with extreme fat compositions; the current study was designed to more nearly mimic human dietary fat intake. Young growing pigs were fed diets containing either 20 or 40% of energy as soy oil, beef tallow or a 50/50 blend of soy oil and tallow. Different dietary fats did not affect concentrations of cholesterol, triacylglycerol or protein in plasma or major lipoprotein fractions. The concentration of phospholipid was less in plasma and in very low density lipoproteins with soy oil feeding than with tallow feeding. The weight percentage of cholesteryl ester in the low density lipoprotein fraction tended to be greater with 40% than with 20% tallow and tended to be less with 40% than with 20% soy oil. Phospholipid as a weight percentage of low density lipoprotein was least in pigs fed soy oil. Tallow feeding increased the percentage of myristic, palmitic, palmitoleic and oleic acids in plasma, relative to both other groups. Soy oil feeding increased the percentage of linoleic and linolenic acids. These moderate diets were not hypercholesterolemic, but they did alter plasma fatty acid composition and phospholipid concentrations in plasma and very low density lipoprotein.

Mugil cephalus roe oil obtained by supercritical fluid extraction affects the lipid profile and viability in cancer HeLa and B16F10 cells.

PubMed

Rosa, A; Piras, A; Nieddu, M; Putzu, D; Cesare Marincola, F; Falchi, A M

2016-09-14

We explored the changes in viability and lipid profile occurring in cancer cells, murine melanoma cells (B16F10 cells) and human cervical carcinoma cells (HeLa cells), when exposed to 24 h-treatments with an n-3 PUFA-rich oil obtained by supercritical extraction with CO2 from Mugil cephalus processed roe (bottarga). The composition of the major lipid classes of bottarga oil was determined by the (13)C NMR technique. Reversed-phase HPLC with DAD/ELSD detection was performed to analyze cells' total fatty acid profile and the levels of phospholipids, total/free cholesterol, triacylglycerols, and cholesteryl esters. Cell-based fluorescent measurements of intracellular membranes and lipid droplets were performed on bottarga oil-treated cells using the Nile red staining technique. The treatments of cancer cells with bottarga oil reduced the viability and affected the fatty acid profile, with a significant n-3 PUFA increase in treated cells. Mullet roe oil uptake modulated the cancer cell lipid composition, inducing a remarkable incorporation of health beneficial n-3 PUFA in the polar and neutral lipid fractions. Bottarga oil treatment influenced the synthesis of intracellular membranes and accumulation of cytoplasmic lipid droplets in cancer cells.

Dietary fish oil stimulates hepatic low density lipoprotein transport in the rat.

PubMed Central

Ventura, M A; Woollett, L A; Spady, D K

1989-01-01

These studies were undertaken to examine the effect of fish oil, safflower oil, and hydrogenated coconut oil on the major processes that determine the concentration of low density lipoprotein (LDL) in plasma, i.e., the rate of LDL production and the rates of receptor-dependent and receptor-independent LDL uptake in the various organs of the body. When fed at the 20% level, fish oil reduced plasma LDL-cholesterol levels by 38% primarily by increasing LDL receptor activity in the liver. Dietary safflower oil also increased hepatic LDL receptor activity; however, since the rate of LDL production also increased, plasma LDL-cholesterol levels remained essentially unchanged. Hydrogenated coconut oil had no effect on LDL receptor activity but increased the rate of LDL-cholesterol production causing plasma LDL-cholesterol levels to increase 46%. Dietary fish oil had no effect on the receptor-dependent transport of asialofetuin by the liver, suggesting that the effect of fish oil on hepatic LDL receptor activity was specific and not due to a generalized alteration in the physical properties of hepatic membranes. Finally, dietary fish oil increased hepatic cholesteryl ester levels and suppressed hepatic cholesterol synthesis rates, suggesting that the up-regulation of hepatic LDL receptor activity in these animals was not simply a response to diminished cholesterol availability in the liver. PMID:2760200

High-Density Lipoprotein-Targeted Therapy and Apolipoprotein A-I Mimetic Peptides.

PubMed

Uehara, Yoshinari; Chiesa, Giulia; Saku, Keijiro

2015-01-01

Numerous randomized clinical trials have established statins as the major standard therapy for atherosclerotic diseases because these molecules decrease the plasma level of low-density lipoprotein (LDL) cholesterol and moderately increase that of plasma high-density lipoprotein (HDL) cholesterol. The reverse cholesterol transport pathway, mediated by HDL particles, has a relevant antiatherogenic potential. An important approach to HDL-targeted therapy is optimization of the HDL-cholesterol level and enhanced removal of plasma cholesterol, together with the prevention and mitigation of inflammation related to atherosclerosis. Small-molecule inhibitors of cholesteryl ester transfer protein (CETP) increase the HDL-cholesterol level in subjects with normal or low HDL-cholesterol. However, CETP inhibitors do not seem to reduce the risk of atherosclerotic diseases. HDL therapies using reconstituted HDL, including apolipoprotein (Apo) A-I Milano, ApoA-I mimetics, or full-length ApoA-I, are dramatically effective in animal models. Of those, the ApoA-I-mimetic peptide called FAMP effectively removes cholesterol via the ABCA1 transporter and acts as an antiatherosclerotic agent by enhancing the biological functions of HDL without elevating the HDL-cholesterol level. Our review of the literature leads us to conclude that HDL-targeted therapies have significant atheroprotective potential and thus may effectively treat patients with cardiovascular diseases.

Cardiovascular effects of torcetrapib in conscious and pentobarbital-anesthetized dogs.

PubMed

Polakowski, James S; King, Andrew J; Campbell, Thomas J; Nelson, Richard A; Preusser, Lee C; Kempf-Grote, Anita J; Marsh, Kennan C; Gintant, Gary A; Cox, Bryan F; Mittelstadt, Scott W

2009-12-01

Torcetrapib is a cholesteryl ester transfer protein inhibitor with an undesired response of increasing arterial pressure in humans. Pressor responses to torcetrapib have been demonstrated in multiple preclinical species. However, these studies have not related plasma concentrations to observed effects. Our purpose was to 1) characterize the cardiovascular responses of torcetrapib in conscious and anesthetized dogs with measured plasma concentrations; and 2) characterize the hemodynamic effects contributing to hypertension using comprehensively instrumented anesthetized dogs. Torcetrapib was dosed orally (3, 30 mg/kg) and intravenously (0.01, 0.33, 0.1 mg/kg) in conscious and anesthetized dogs, respectively. Mean arterial pressure and heart rate were monitored in both models; additional parameters were measured in anesthetized dogs. Plasma drug concentrations were assessed in both models. In conscious and anesthetized dogs, torcetrapib increased mean arterial pressure 25 and 18 mm Hg and heart rate 35 and 21 beats/min, at 2.94 and 3.99 microg/mL, respectively. In anesthetized dogs, torcetrapib increased pulmonary arterial pressure, both systemic and pulmonary hypertension driven by increases in vascular resistance. The compound increased rate pressure product and myocardial contractility while decreasing time to systolic pressure recovery and ejection time. Thus, torcetrapib-induced pressor responses are mediated by systemic and pulmonary vasoconstriction and are associated with increased myocardial oxygen consumption and positive inotropy.

Hydrolysis of platelet-activating factor by human serum paraoxonase.

PubMed Central

Rodrigo, L; Mackness, B; Durrington, P N; Hernandez, A; Mackness, M I

2001-01-01

Human serum paraoxonase (human PON1) has been shown to be important in the metabolism of phospholipid and cholesteryl ester hydroperoxides, thereby preventing the oxidation of low-density lipoprotein (LDL) and retarding atherogenesis. However, the exact substrate specificity of PON1 has not been established. In the present study we show that purified PON1 hydrolyses platelet-activating factor (PAF). We could find no evidence for contamination of our preparation with authentic platelet-activating-factor acetylhydrolase (PAFAH) by immunoblotting with a PAFAH monoclonal antibody or by sequencing the purified protein. In addition the specific PAFAH inhibitor SB-222657 did not affect the ability of PON1 to hydrolyse PAF (30.1+/-2.8 micromol/min per mg of protein with no inhibitor; 31.4+/-2.2 micromol/min per mg of protein with 100 nM inhibitor) or phenyl acetate (242.6+/-30.8 versus 240.8+/-31.5 micromol/min per mg of protein with and without inhibitor respectively). SB-222657 was also unable to inhibit PAF hydrolysis by isolated human high-density lipoprotein (HDL), but completely abolished the activity of human LDL. Ostrich (Struthio camelus) HDL, which does not contain PON1, was unable to hydrolyse PAF. These data provide evidence that PON1 may limit the action of this bioactive pro-inflammatory phospholipid. PMID:11171072

Dalcetrapib and anacetrapib differently impact HDL structure and function in rabbits and monkeys[S

PubMed Central

Brodeur, Mathieu R.; Rhainds, David; Charpentier, Daniel; Mihalache-Avram, Teodora; Mecteau, Mélanie; Brand, Geneviève; Chaput, Evelyne; Perez, Anne; Niesor, Eric J.; Rhéaume, Eric; Maugeais, Cyrille; Tardif, Jean-Claude

2017-01-01

Inhibition of cholesteryl ester transfer protein (CETP) increases HDL cholesterol (HDL-C) levels. However, the circulating CETP level varies and the impact of its inhibition in species with high CETP levels on HDL structure and function remains poorly characterized. This study investigated the effects of dalcetrapib and anacetrapib, the two CETP inhibitors (CETPis) currently being tested in large clinical outcome trials, on HDL particle subclass distribution and cholesterol efflux capacity of serum in rabbits and monkeys. New Zealand White rabbits and vervet monkeys received dalcetrapib and anacetrapib. In rabbits, CETPis increased HDL-C, raised small and large α-migrating HDL, and increased ABCA1-induced cholesterol efflux. In vervet monkeys, although anacetrapib produced similar results, dalcetrapib caused opposite effects because the LDL-C level was increased by 42% and HDL-C decreased by 48% (P < 0.01). The levels of α- and preβ-HDL were reduced by 16% (P < 0.001) and 69% (P < 0.01), resulting in a decrease of the serum cholesterol efflux capacity. CETPis modulate the plasma levels of mature and small HDL in vivo and consequently the cholesterol efflux capacity. The opposite effects of dalcetrapib in different species indicate that its impact on HDL metabolism could vary greatly according to the metabolic environment. PMID:28515138

Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach[S

PubMed Central

Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A.; Ramanujan, Saroja

2016-01-01

The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. PMID:26522778

Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach.

PubMed

Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A; Ramanujan, Saroja

2016-01-01

The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

In vivo metabolic fingerprinting of neutral lipids with hyperspectral stimulated Raman scattering microscopy.

PubMed

Fu, Dan; Yu, Yong; Folick, Andrew; Currie, Erin; Farese, Robert V; Tsai, Tsung-Huang; Xie, Xiaoliang Sunney; Wang, Meng C

2014-06-18

Metabolic fingerprinting provides valuable information on the physiopathological states of cells and tissues. Traditional imaging mass spectrometry and magnetic resonance imaging are unable to probe the spatial-temporal dynamics of metabolites at the subcellular level due to either lack of spatial resolution or inability to perform live cell imaging. Here we report a complementary metabolic imaging technique that is based on hyperspectral stimulated Raman scattering (hsSRS). We demonstrated the use of hsSRS imaging in quantifying two major neutral lipids: cholesteryl ester and triacylglycerol in cells and tissues. Our imaging results revealed previously unknown changes of lipid composition associated with obesity and steatohepatitis. We further used stable-isotope labeling to trace the metabolic dynamics of fatty acids in live cells and live Caenorhabditis elegans with hsSRS imaging. We found that unsaturated fatty acid has preferential uptake into lipid storage while saturated fatty acid exhibits toxicity in hepatic cells. Simultaneous metabolic fingerprinting of deuterium-labeled saturated and unsaturated fatty acids in living C. elegans revealed that there is a lack of interaction between the two, unlike previously hypothesized. Our findings provide new approaches for metabolic tracing of neutral lipids and their precursors in living cells and organisms, and could potentially serve as a general approach for metabolic fingerprinting of other metabolites.

Acute sterol o-acyltransferase 2 (SOAT2) knockdown rapidly mobilizes hepatic cholesterol for fecal excretion.

PubMed

Marshall, Stephanie M; Gromovsky, Anthony D; Kelley, Kathryn L; Davis, Matthew A; Wilson, Martha D; Lee, Richard G; Crooke, Rosanne M; Graham, Mark J; Rudel, Lawrence L; Brown, J Mark; Temel, Ryan E

2014-01-01

The primary risk factor for atherosclerotic cardiovascular disease is LDL cholesterol, which can be reduced by increasing cholesterol excretion from the body. Fecal cholesterol excretion can be driven by a hepatobiliary as well as a non-biliary pathway known as transintestinal cholesterol efflux (TICE). We previously showed that chronic knockdown of the hepatic cholesterol esterifying enzyme sterol O-acyltransferase 2 (SOAT2) increased fecal cholesterol loss via TICE. To elucidate the initial events that stimulate TICE, C57Bl/6 mice were fed a high cholesterol diet to induce hepatic cholesterol accumulation and were then treated for 1 or 2 weeks with an antisense oligonucleotide targeting SOAT2. Within 2 weeks of hepatic SOAT2 knockdown (SOAT2HKD), the concentration of cholesteryl ester in the liver was reduced by 70% without a reciprocal increase in hepatic free cholesterol. The rapid mobilization of hepatic cholesterol stores resulted in a ∼ 2-fold increase in fecal neutral sterol loss but no change in biliary cholesterol concentration. Acute SOAT2HKD increased plasma cholesterol carried primarily in lipoproteins enriched in apoB and apoE. Collectively, our data suggest that acutely reducing SOAT2 causes hepatic cholesterol to be swiftly mobilized and packaged onto nascent lipoproteins that feed cholesterol into the TICE pathway for fecal excretion.

Direct infusion MS-based lipid profiling reveals the pharmacological effects of compound K-reinforced ginsenosides in high-fat diet induced obese mice.

PubMed

Shon, Jong Cheol; Shin, Hwa-Soo; Seo, Yong Ki; Yoon, Young-Ran; Shin, Heungsop; Liu, Kwang-Hyeon

2015-03-25

The serum lipid metabolites of lean and obese mice fed normal or high-fat diets were analyzed via direct infusion nanoelectrospray-ion trap mass spectrometry followed by multivariate analysis. In addition, lipidomic biomarkers responsible for the pharmacological effects of compound K-reinforced ginsenosides (CK), thus the CK fraction, were evaluated in mice fed high-fat diets. The obese and lean groups were clearly discriminated upon principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) score plot, and the major metabolites contributing to such discrimination were triglycerides (TGs), cholesteryl esters (CEs), phosphatidylcholines (PCs), and lysophosphatidylcholines (LPCs). TGs with high total carbon number (>50) and low total carbon number (<50) were negatively and positively associated with high-fat diet induced obesity in mice, respectively. When the CK fraction was fed to obese mice that consumed a high-fat diet, the levels of certain lipids including LPCs and CEs became similar to those of mice fed a normal diet. Such metabolic markers can be used to better understand obesity and related diseases induced by a hyperlipidic diet. Furthermore, changes in the levels of such metabolites can be employed to assess the risk of obesity and the therapeutic effects of obesity management.

Potential human cholesterol esterase inhibitor design: benefits from the molecular dynamics simulations and pharmacophore modeling studies.

PubMed

John, Shalini; Thangapandian, Sundarapandian; Lee, Keun Woo

2012-01-01

Human pancreatic cholesterol esterase (hCEase) is one of the lipases found to involve in the digestion of large and broad spectrum of substrates including triglycerides, phospholipids, cholesteryl esters, etc. The presence of bile salts is found to be very important for the activation of hCEase. Molecular dynamic simulations were performed for the apoform and bile salt complexed form of hCEase using the co-ordinates of two bile salts from bovine CEase. The stability of the systems throughout the simulation time was checked and two representative structures from the highly populated regions were selected using cluster analysis. These two representative structures were used in pharmacophore model generation. The generated pharmacophore models were validated and used in database screening. The screened hits were refined for their drug-like properties based on Lipinski's rule of five and ADMET properties. The drug-like compounds were further refined by molecular docking simulation using GOLD program based on the GOLD fitness score, mode of binding, and molecular interactions with the active site amino acids. Finally, three hits of novel scaffolds were selected as potential leads to be used in novel and potent hCEase inhibitor design. The stability of binding modes and molecular interactions of these final hits were re-assured by molecular dynamics simulations.

Cholesteryl-containing ionic liquid crystals composed of alkylimidazolium cations and different anions

NASA Astrophysics Data System (ADS)

Lan, Xin; Bai, Lu; Li, Xin; Ma, Shuang; He, Xiaozhi; Meng, Fanbao

2014-10-01

Cholesteryl-containing ionic liquid crystals (ILCs) 1-cholesteryloxycarbonylmethyl(propyl)-3-methyl(butyl)imidazolium chlorides ([Ca-Me-Im]Cl, [Ca-Bu-Im]Cl, [Cb-Me-Im]Cl and [Cb-Bu-Im]Cl) and corresponding imidazolium tetrachloroaluminates ([Ca-Me-Im]AlCl4, [Ca-Bu-Im]AlCl4, [Cb-Me-Im]AlCl4 and [Cb-Bu-Im]AlCl4) were synthesized in this work, and the chemical structure, LC behavior and ionic conductivity of all these ILCs were characterized by several technical methods. The imidazolium-based salts with Cl- ions showed chiral smectic A (SA*) phase on both heating and cooling cycles, while the tetrachloroaluminates exhibited chiral nematic (N*) phase. The mesophase was confirmed by characteristic LC textures observed by polarizing optical microscopy and typical diffractogram obtained by X-ray diffraction measurements. The samples with similar cholesteryl-linkage component showed similar phase transition temperature and entropy, indicating the cholesteryl component influence predominately on the phase transition rather than alkyl substituents on the imidazole ring. The imidazolium tetrachloroaluminates display relatively low phase transition temperature compared with the precursor chlorides. The functional difference in LC behavior and ionic conductivity were discussed by investigated the structural difference between the Cl--containing and AlCl4-containing materials. The imidazolium chlorides exhibited layer structure both in crystal and mesophase states, and should be organized with a ‘head-to-tail’ organization to form interdigitated monolayer structures due to the tight ion pairs. But the imidazolium tetrachloroaluminates displayed layer structure only in crystal phase, and should be organized in ‘head-to-head’ arrangements form bilayer structures due to loose combination of ion pairs despite of hydrogen-bond and electrostatic attraction interaction.

Effects of elevated temperature postharvest on color aspect, physiochemical characteristics, and aroma components of pineapple fruits.

PubMed

Liu, Chuanhe; Liu, Yan

2014-12-01

In this work, 2 separate experiments were performed to describe the influence of elevated temperature treatments postharvest on the color, physiochemical characteristics and aroma components of pineapple fruits during low-temperature seasons. The L* (lightness) values of the skin and pulp of pineapple fruits were decreased. The a* (greenness-redness) and b* (blueness-yellowness) values of the skin and pulp were all markedly increased. The elevated temperature significantly increased the contents of total soluble solids (TSS) and slightly affected contents of vitamin C (nonsignificant). Titratable acidity (TA) of pineapple fruits were notably decreased, whereas the values of TSS/TA of pineapple fruits were significantly increased. The firmness of the pineapple fruits decreased and more esters and alkenes were identified. The total relative contents of esters were increased, and the total relative contents of alkenes were decreased. © 2014 Institute of Food Technologists®

Induction of apoptosis and necroptosis by 24(S)-hydroxycholesterol is dependent on activity of acyl-CoA:cholesterol acyltransferase 1

PubMed Central

Yamanaka, K; Urano, Y; Takabe, W; Saito, Y; Noguchi, N

2014-01-01

24(S)-hydroxycholesterol (24S-OHC), which is enzymatically produced in the brain, has an important role in maintaining brain cholesterol homeostasis. We have previously reported that 24S-OHC induces necroptosis in human neuroblastoma SH-SY5Y cells. In the present study, we investigated the mechanisms by which 24S-OHC-induced cell death occurs. We found that lipid droplets formed at the early stages in the treatment of SH-SY5Y cells with 24S-OHC. These lipid droplets could be almost completely eliminated by treatment with a specific inhibitor or by siRNA knockdown of acyl-CoA:cholesterol acyltransferase 1 (ACAT1). In association with disappearance of lipid droplets, cell viability was recovered by treatment with the inhibitor or siRNA for ACAT1. Using gas chromatography–mass spectrometry, we confirmed that 24S-OHC-treated cells exhibited accumulation of 24S-OHC esters but not of cholesteryl esters and confirmed that accumulation of 24S-OHC esters was reduced when ACAT1 was inhibited. 24S-OHC induced apoptosis in T-lymphoma Jurkat cells, which endogenously expressed caspase-8, but did not induce apoptosis in SH-SY5Y cells, which expressed no caspase-8. In Jurkat cells treated with the pan-caspase inhibitor ZVAD and in caspase-8-deficient Jurkat cells, 24S-OHC was found to induce caspase-independent cell death, and this was partially but significantly inhibited by Necrostatin-1. Similarly, knockdown of receptor-interacting protein kinase 3, which is one of the essential kinases for necroptosis, significantly suppressed 24S-OHC-induced cell death in Jurkat cells treated with ZVAD. These results suggest that 24S-OHC can induce apoptosis or necroptosis, which of the two is induced being determined by caspase activity. Regardless of the presence or absence of ZVAD, 24S-OHC treatment induced the formation of lipid droplets and cell death in Jurkat cells, and this was suppressed by treatment with ACAT1 inhibitor. Collectively, these results suggest that it is ACAT1-catalyzed 24S-OHC esterification and the resulting lipid droplet formation that is the initial key event which is responsible for 24S-OHC-induced cell death. PMID:24407243

Induction of apoptosis and necroptosis by 24(S)-hydroxycholesterol is dependent on activity of acyl-CoA:cholesterol acyltransferase 1.

PubMed

Yamanaka, K; Urano, Y; Takabe, W; Saito, Y; Noguchi, N

2014-01-09

24(S)-hydroxycholesterol (24S-OHC), which is enzymatically produced in the brain, has an important role in maintaining brain cholesterol homeostasis. We have previously reported that 24S-OHC induces necroptosis in human neuroblastoma SH-SY5Y cells. In the present study, we investigated the mechanisms by which 24S-OHC-induced cell death occurs. We found that lipid droplets formed at the early stages in the treatment of SH-SY5Y cells with 24S-OHC. These lipid droplets could be almost completely eliminated by treatment with a specific inhibitor or by siRNA knockdown of acyl-CoA:cholesterol acyltransferase 1 (ACAT1). In association with disappearance of lipid droplets, cell viability was recovered by treatment with the inhibitor or siRNA for ACAT1. Using gas chromatography-mass spectrometry, we confirmed that 24S-OHC-treated cells exhibited accumulation of 24S-OHC esters but not of cholesteryl esters and confirmed that accumulation of 24S-OHC esters was reduced when ACAT1 was inhibited. 24S-OHC induced apoptosis in T-lymphoma Jurkat cells, which endogenously expressed caspase-8, but did not induce apoptosis in SH-SY5Y cells, which expressed no caspase-8. In Jurkat cells treated with the pan-caspase inhibitor ZVAD and in caspase-8-deficient Jurkat cells, 24S-OHC was found to induce caspase-independent cell death, and this was partially but significantly inhibited by Necrostatin-1. Similarly, knockdown of receptor-interacting protein kinase 3, which is one of the essential kinases for necroptosis, significantly suppressed 24S-OHC-induced cell death in Jurkat cells treated with ZVAD. These results suggest that 24S-OHC can induce apoptosis or necroptosis, which of the two is induced being determined by caspase activity. Regardless of the presence or absence of ZVAD, 24S-OHC treatment induced the formation of lipid droplets and cell death in Jurkat cells, and this was suppressed by treatment with ACAT1 inhibitor. Collectively, these results suggest that it is ACAT1-catalyzed 24S-OHC esterification and the resulting lipid droplet formation that is the initial key event which is responsible for 24S-OHC-induced cell death.

Statistical optimization for lipase production from solid waste of vegetable oil industry.

PubMed

Sahoo, Rajesh Kumar; Kumar, Mohit; Mohanty, Swati; Sawyer, Matthew; Rahman, Pattanathu K S M; Sukla, Lala Behari; Subudhi, Enketeswara

2018-04-21

The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from Bacillus licheniformis, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.

Emissions analysis on diesel engine fuelled with cashew nut shell biodiesel and pentanol blends.

PubMed

Devarajan, Yuvarajan; Munuswamy, Dinesh Babu; Nagappan, BeemKumar

2017-05-01

The present work is intended to investigate the emission characteristics of neat cashew nut shell methyl ester (CNSME100) by adding pentanol at two different proportions and compared with the baseline diesel. CNSME100 is prepared by the conventional transesterification process. CNSME100 is chosen due to its non-edible nature. Pentanol is chosen as an additive because of its higher inbuilt oxygen content and surface to volume ratio which reduces the drawbacks of neat CNSME100. Emission characteristics were carried out in single cylinder naturally aspirated CI engine fuelled with neat cashew nut shell methyl ester (CNSME), cashew nut shell methyl ester and pentanol by 10% volume (CNSME90P10), cashew nut shell methyl ester and pentanol by 20% volume (CNSME80P20), and diesel. This work also aims to investigate the feasibility of operating an engine fuelled with neat methyl ester and alcohol blends. Experimental results showed that by blending higher alcohol to neat cashew nut shell methyl ester reduces the emissions significantly. It is also found that the emission from neat methyl ester and pentanol blends is lesser than diesel at all loads.

Identification of rare diseases by screening a population selected on the basis of routine pathology results-the PATHFINDER project: lysosomal acid lipase/cholesteryl ester storage disease substudy.

PubMed

Reynolds, Timothy M; Mewies, Clare; Hamilton, John; Wierzbicki, Anthony S

2018-01-22

Lysosomal acid lipase deficiency (LALD) is an autosomal recessive disorder of cholesterol ester storage associated with hepatic disease, cirrhosis and accelerated atherosclerosis. Its prevalence in the general population, patients with dyslipidaemia and raised transaminases is unclear. This study attempted to identify the prevalence of LALD from patients with abnormal results in laboratory databases. Electronic laboratory databases were interrogated to identify from clinical biochemistry records patients with a phenotype of low high-density lipoprotein-cholesterol (≤0.85 mmol/L; 33 mg/dL) and with elevated alanine or aspartate transaminases (≥60 IU/L) on one occasion or more over a 3-year time interval. Patients were recalled, and a dried blood spot sample was collected for lysosomal acid lipase determination by a fluorimetric enzyme assay. Histopathology databases of liver biopsies were interrogated for patients with features of 'microvesicular cirrhosis' or 'cryptogenic cirrhosis' in the report. Histological blocks were sampled, and samples were analysed by next-generation sequencing for the presence of mutations in the LAL gene. Samples were obtained from 1825 patients with dyslipidaemia and elevated transaminases. No cases of LALD were identified. Liver biopsies were obtained from six patients. DNA extraction was successful from four patients. Two patients were homozygous for the LAL c.46A>C;p.Thr16Pro unclassified variant in exon 2. Pathology databases hold routine information that can be used to identify patients with specific patterns of results or those who had biopsies to allow targeted testing for possible causes of disease. Biochemical screening suggests that the gene frequency of LAL deficiency in adults is less than 1 in 100. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Production and Characterization of Ethyl Ester from Crude Jatropha curcas Oil having High Free Fatty Acid Content

NASA Astrophysics Data System (ADS)

Kumar, Rajneesh; Dixit, Anoop; Singh, Shashi Kumar; Singh, Gursahib; Sachdeva, Monica

2015-09-01

The two step process was carried out to produce biodiesel from crude Jatropha curcas oil. The pretreatment process was carried out to reduce the free fatty acid content by (≤2 %) acid catalyzed esterification. The optimum reaction conditions for esterification were reported to be 5 % H2SO4, 20 % ethanol and 1 h reaction time at temperature of 65 °C. The pretreatment process reduced the free fatty acid of oil from 7 to 1.85 %. In second process, alkali catalysed transesterification of pretreated oil was carried and the effects of the varying concentrations of KOH and ethanol: oil ratios on percent ester recovery were investigated. The optimum reaction conditions for transesterification were reported to be 3 % KOH (w/v of oil) and 30 % (v/v) ethanol: oil ratio and reaction time 2 h at 65 °C. The maximum percent recovery of ethyl ester was reported to be 60.33 %.

Analysis of confiscated black market drugs using chromatographic and mass spectrometric approaches.

PubMed

Thevis, Mario; Schrader, Yvonne; Thomas, Andreas; Sigmund, Gerd; Geyer, Hans; Schänzer, Wilhelm

2008-04-01

In the context of house searches in Germany, numerous drugs were confiscated and subjected to chemical analysis, including anabolic agents such as various anabolic-androgenic steroids (stanozolol, testosterone derivatives, trenbolone esters, etc.) and clenbuterol, as well as agents with anti-estrogenic activity (tamoxifen, clomiphene), drugs stimulating virility (sildenafil, tadalafil), and unlabeled plastic bags. Liquid chromatography-tandem mass spectrometry, gas chromatography-mass spectrometry with nitrogen-phosphorus specific detection, gel electrophoresis, and immunological tests were employed to test for the effective content of 70 products. In 18 cases (25.7%), the declared ingredients differed from the actual content, in particular concerning anabolic-androgenic steroids. Nandrolone and trenbolone esters, for instance, were frequently substituted or complemented by various testosterone derivatives, and several testosterone depot formulations originally composed of four different esters were found to contain fewer or wrong components. Except for those drugs supposedly originating from so-called underground labs, fake packings were hardly or not distinguishable from original boxes by visual inspection.

Synthesis of fatty acid methyl ester from crude jatropha (Jatropha curcas Linnaeus) oil using aluminium oxide modified Mg-Zn heterogeneous catalyst.

PubMed

Olutoye, M A; Hameed, B H

2011-06-01

The synthesis of fatty acid methyl esters (FAME) as a substitute to petroleum diesel was investigated in this study from crude jatropha oil (CJO), a non-edible, low-cost alternative feedstock, using aluminium modified heterogeneous basic oxide (Mg-Zn) catalyst. The transesterification reaction with methanol to methyl esters yielded 94% in 6h with methanol-oil ratio of 11:1, catalyst loading of 8.68 wt.% at 182°C and the properties of CJO fuel produced were determine and found to be comparable to the standards according to ASTM. In the range of experimental parameters investigated, it showed that the catalyst is selective to production of methyl esters from oil with high free fatty acid (FFA) and water content of 7.23% and 3.28%, respectively in a single stage process. Thus, jatropha oil is a promising feedstock for methyl ester production and large scale cultivation will help to reduce the product cost. Copyright © 2011 Elsevier Ltd. All rights reserved.

Covalently Cross-linked Elastomers with Self-Healing and Malleable Abilities Enabled by Boronic Ester Bonds.

PubMed

Chen, Yi; Tang, Zhenghai; Zhang, Xuhui; Liu, Yingjun; Wu, Siwu; Guo, Baochun

2018-06-26

Covalently cross-linked rubbers are renowned for their high elasticity that play an indispensable role in various applications including tires, seals, medical implants. Development of self-healing and malleable rubbers is highly desirable as it allows for damage repair and reprocessibility to extend the lifetime and alleviate environmental pollution. Herein, we propose a facile approach to prepare permanently cross-linked yet self-healing and recyclable diene-rubber by programming dynamic boronic ester linkages into the network. The network is synthesized through one-pot thermally initiated thiol-ene "click" reaction between a novel dithiol-containing boronic ester cross-linker and commonly used styrene-butadiene rubber (SBR) without modifying the macromolecular structure. The resulted samples are covalently cross-linked and possess relatively high mechanical strength which can be readily tailored by varying boronic ester content. Owning to the transesterification of boronic ester bonds, the samples can alter network topologies, endowing the materials with self-healing ability and malleability.

Degradation of Jatropha curcas phorbol esters derived from Jatropha oil cake and their tumor-promoting activity.

PubMed

Nakao, Motoyuki; Hasegawa, Go; Yasuhara, Tadashi; Ishihara, Yoko

2015-04-01

Large amount of oil cake is generated during biodiesel production from Jatropha seeds. Although Jatropha oil cake is rich in plant nutrients, presence of toxic phorbol esters restricts the usage of oil cake as a fertilizer. The objective of this study is to evaluate the components and tumor promoting activity of phorbol esters in Jatropha oil cake-supplemented soil and plants grown in the treated soil. Contents and their biological activity of Jatropha phorbol esters in soil and plants were sequentially analyzed by high-performance liquid chromatography (HPLC) and in vitro cell transformation assay, respectively. Disappearance of Jatropha phorbol-ester-specific peaks were followed with HPLC during incubation of Jatropha oil cake with soil for five weeks. Along with the degradation of Jatropha phorbol ester in soil, tumor-promoting activity in the sample was also attenuated and ultimately disappeared. Jatropha phorbol esters and tumor promoting activity were not detected from mustard spinach grown in the Jatropha oil cake-supplemented soil. In addition, the esterase KM109 degrades DHPB (see definition below; Jatropha phorbol ester) and reduced its tumor-promoting activity. From these data, we conclude: (1) components and tumor promoting activity of Jatropha phorbol esters in the oil cake disappeared completely by incubation with soil for five-week, (2) Jatropha phorbol esters did not transfer into plants grown in the Jatropha oil cake-supplemented soil, and (3) DHPB can be degraded by esterase from soil bacterium. These observations are useful for utilization of Jatropha oil cake as a fertilizer. Copyright © 2014 Elsevier Inc. All rights reserved.

Cyanate Ester Resin Modified with Nano-particles for Inclusion in Continuous Fiber Reinforced Composites

DTIC Science & Technology

2011-02-25

custom built rotating oven, to prevent settling during cure. The filler content in the test specimen are verified by thermogravimetric analysis (TGA...using a Shimadzu SA-CP3 centrifugal particle size analyzer. The moisture absorption of the nanoparticles was studied using a Q50 thermogravimetric ...low viscosity bisphenol E cyanate ester resin (BECy) resin reinforced with macro scale carbon fibers and negative CTE nanoparticles . Polymer

Effect of the environment microbiota on the flavour of light-flavour Baijiu during spontaneous fermentation.

PubMed

Pang, Xiao-Na; Han, Bei-Zhong; Huang, Xiao-Ning; Zhang, Xin; Hou, Lin-Feng; Cao, Ming; Gao, Li-Juan; Hu, Guang-Hui; Chen, Jing-Yu

2018-02-21

Light-flavour Baijiu is a type of Chinese liquor with a pure and mild flavour produced by traditional spontaneous solid-state fermentation. The flavour of this liquor has been found to vary in the different periods of annual production. To explore the factors affecting flavour, the microbiota of the surrounding environment, starter and fermentation process in different periods were investigated. Results showed that the ester content and acidity of light-flavour Baijiu were significantly lower when annual production was resumed after a summer break. HCA plot of volatile flavour profile and bacterial PCoA results indicated that the differences occurred at later stages, mainly due to different structures of Lactobacillus. Correlation analysis by O2PLS indicated that Lactobacillus positively correlated with esters. Species-level analysis showed that the lack of L. acetotolerans on the surface of the jar might cause a lag in fermentation and lower ester content. Thereafter, L. acetotolerans was revived during fermentation and enriched on the surface of the jar, which promoted ester formation. As important sources of L. acetotolerans, the air and fermentation jars played a critical role during fermentation. Therefore, this systematic study on environmental microbial ecology is valuable for quality control and to explore environmental microbiota functions during spontaneous fermentation.

Miscibility of choline-substituted polyphosphazenes with PLGA and osteoblast activity on resulting blends.

PubMed

Weikel, Arlin L; Owens, Steven G; Morozowich, Nicole L; Deng, Meng; Nair, Lakshmi S; Laurencin, Cato T; Allcock, Harry R

2010-11-01

The preparation of phosphazene tissue engineering scaffolds with bioactive side groups has been accomplished using the biological buffer, choline chloride. Mixed-substituent phosphazene cyclic trimers (as model systems) and polymers with choline chloride and glycine ethyl ester, alanine ethyl ester, valine ethyl ester, or phenylalanine ethyl ester were synthesized. Two different synthetic protocols were examined. A sodium hydride mediated route resulted in polyphosphazenes with a low choline content, while a cesium carbonate mediated process produced polyphosphazenes with higher choline content. The phosphazene structures and physical properties were studied using multinuclear NMR, differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) techniques. The resultant polymers were then blended with PLGA (50:50) or PLGA (85:15) and characterized by DSC analysis and scanning electron microscopy (SEM). Polymer products obtained via the sodium hydride route produced miscible blends with both ratios of PLGA, while the cesium carbonate route yielded products with reduced blend miscibility. Heterophase hydrolysis experiments in aqueous media revealed that the polymer blends hydrolyzed to near-neutral pH media (∼5.8 to 6.8). The effect of different molecular structures on cellular adhesion showed osteoblast proliferation with an elevated osteoblast phenotype expression compared to PLGA over a 21-day culture period. Copyright © 2010 Elsevier Ltd. All rights reserved.

New Insights on Degumming and Bleaching Process Parameters on The Formation of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Refined, Bleached, Deodorized Palm Oil.

PubMed

Sim, Biow Ing; Muhamad, Halimah; Lai, Oi Ming; Abas, Faridah; Yeoh, Chee Beng; Nehdi, Imededdine Arbi; Khor, Yih Phing; Tan, Chin Ping

2018-04-01

This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

Other factors to consider in the formation of chloropropandiol fatty esters in oil processes.

PubMed

Ramli, Muhamad Roddy; Siew, Wai Lin; Ibrahim, Nuzul Amri; Kuntom, Ainie; Abd Razak, Raznim Arni

2015-01-01

This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.

How 'ground-picked' olive fruits affect virgin olive oil ethanol content, ethyl esters and quality.

PubMed

Beltran, Gabriel; Sánchez, Raquel; Sánchez-Ortiz, Araceli; Aguilera, Maria P; Bejaoui, Mohamed A; Jimenez, Antonio

2016-08-01

Olives dropped on the ground naturally sometimes are not separated from those fresh and healthy collected from the tree for harvest and processing. In this work we compared the quality, ethanol content and bioactive components of virgin olive oils from ground-picked olives, tree-picked fruits and their mixture. Ground-picked olives produced 'Lampante' virgin olive oils; these are of a lower quality category, because of important alterations in chemical and sensory characteristics. Ethyl esters showed the highest values, although under the regulated limit. The mixture of ground and tree-picked olives gave oils classified as 'virgin' because of sensory defects, although the quality parameters did not exceed the limits for the 'extra' category. Ethanol content showed a significant increase in the oils from ground- picked olives and their mixture with respect to those from tree-picked fruits. Furthermore, bioactive compounds showed a significant decrease as fruit quality was poorer. Ground-picked olives must be harvested and processed separately since they produce low-quality virgin olive oils with sensory defects and lower concentrations of bioactive compounds. The higher acidity and ethanol concentration observed in oils from ground-picked fruits or their mixture may help ethyl ester synthesis during storage. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Composition of Lutein Ester Regioisomers in Marigold Flower, Dietary Supplement, and Herbal Tea.

PubMed

Abdel-Aal, El-Sayed M; Rabalski, Iwona

2015-11-11

Characterization of lutein and its esters in a health product is necessary for its efficacy. In the current study lutein ester regioisomers were quantified and identified in several dietary supplements and herbal teas in comparison with marigold flower, the commercial source of lutein. The products were extracted with three solvents and separated on a C30 column. The separated esters were identified/confirmed with LC-MS in APCI+ve mode with the use of synthetic lutein esters. The total content of lutein esters substantially varied among marigold flowers (167-5752 μg/g), supplements (88,000-110,700 μg/g), and herbal teas (12.4-91.3 μg/g). Lutein supplement had a lutein profile similar to that of marigold flower, whereas herbal tea showed an extremely different profile. Lutein dipalmitate was the dominant compound in supplements and marigold flowers followed by lutein 3'-O-myristate-3-O-palmitate and lutein 3'-O-palmitate-3-O-myristate. Lutein was the major compound in marigold herbal tea with small amounts of lutein mono- and diesters. Differences in the concentration and composition of lutein compounds among marigold products could indicate distinct product quality and lutein bioavailability.

Effects of temperature and NaCl on the formation of 3-MCPD esters and glycidyl esters in refined, bleached and deodorized palm olein during deep-fat frying of potato chips.

PubMed

Wong, Yu Hua; Muhamad, Halimah; Abas, Faridah; Lai, Oi Ming; Nyam, Kar Lin; Tan, Chin Ping

2017-03-15

The effects of frying duration, frying temperature and concentration of sodium chloride on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GEs) of refined, bleached and deodorized (RBD) palm olein during deep-fat frying (at 160°C and 180°C) of potato chips (0%, 1%, 3% and 5% NaCl) for 100min/d for five consecutive days in eight systems were compared in this study. All oil samples collected after each frying cycle were analyzed for 3-MCPD esters, GEs, free fatty acid (FFA) contents, specific extinction at 232 and 268 nm (K 232 and K 268 ), p-anisidine value (pAV), and fatty acid composition. The 3-MCPD ester trend was decreasing when the frying duration increased, whereas the trend was increasing when frying temperature and concentration of NaCl increased. The GEs trend was increasing when the frying temperature, frying duration and concentration of NaCl increased. All of the oil qualities were within the safety limit. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

PubMed

Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

2016-01-01

Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Synthesis of fruity ethyl esters by acyl coenzyme A: alcohol acyltransferase and reverse esterase activities in Oenococcus oeni and Lactobacillus plantarum.

PubMed

Costello, P J; Siebert, T E; Solomon, M R; Bartowsky, E J

2013-03-01

To assess the abilities of commercial wine lactic acid bacteria (LAB) to synthesize potentially flavour active fatty acid ethyl esters and determine mechanisms involved in their production. Oenococcus oeni AWRI B551 produced significant levels of ethyl hexanoate and ethyl octanoate following growth in an ethanolic test medium, and ester formation generally increased with increasing pH (4.5 > 3.5), anaerobiosis and precursor supplementation. Cell-free extracts of commercial O. oeni strains and Lactobacillus plantarum AWRI B740 were also tested for ester-synthesizing capabilities in a phosphate buffer via: (i) acyl coenzyme A: alcohol acyltransferase (AcoAAAT) activity and (ii) reverse esterase activity. For both ester-synthesizing activities, strain-dependent variation was observed, with AcoAAAT activity generally greater than reverse esterase. Reverse esterase in O. oeni AWRI B551 also esterified 1-propanol to produce propyl octanoate, and deuterated substrates ([(2)H(6)]ethanol and [(2)H(15)]octanoic acid) to produce the fully deuterated ester, [(2)H(5)]ethyl [(2)H(15)]octanoate. Wine LAB exhibit ethyl ester-synthesizing capability and possess two different ester-synthesizing activities, one of which is associated with an acyl coenzyme A: alcohol acyltransferase. This study demonstrates that wine LAB exhibit enzyme activities that can augment the ethyl ester content of wine. This knowledge will facilitate greater control over the impacts of malolactic fermentation on the fruity sensory properties and quality of wine. © 2012 Australian Wine Research Institute © 2012 The Society for Applied Microbiology.

Near Infrared Spectroscopic Identification of Alkyl Aromatic Esters and Phenyl Ketones

NASA Astrophysics Data System (ADS)

Nelyubov, D. V.; Vazhenin, D. A.; Kudriavtsev, A. A.; Buzolina, A. Yu.

2018-03-01

Bands characterizing the content of carbon atoms in alkyl (7177-7205 cm-1) and phenyl structural fragments (9175-9192 cm-1) in organic molecules were revealed by studying the near infrared spectra of such compounds. The optical density at the maxima of these absorption bands was shown to depend strongly on the fraction of carbon atoms in the corresponding fragments. The developed models proved to be adequate for determining the fraction of carbon atoms in alkyl aromatic esters and phenyl ketones. The feasibility of modeling the molecular structure of alkyl aromatic esters using regression models was demonstrated for the product of the condensation of oleic acid and benzyl alcohol.

Rapid and simple micromethod for the simultaneous determination of 3-MCPD and 3-MCPD esters in different foodstuffs.

PubMed

Küsters, Markus; Bimber, Ute; Ossenbrüggen, Alexandra; Reeser, Sebastian; Gallitzendörfer, Rainer; Gerhartz, Michael

2010-06-09

This paper describes for the first time a micromethod for the simultaneous determination of 3-monochloropropane-1,2-diol (3-MCPD) and fatty acid esters of 3-MCPD (3-MCPD esters) in different foodstuffs. 3-MCPD and 3-MCPD esters were isolated from food products using a single extraction step separating hydrophilic and lipophilic compounds. An aliquot of the aqueous layer was analyzed for the content of 3-MCPD while a part of the organic layer was analyzed for 3-MCPD esters after cleavage with sodium methoxide. After a simple derivatization procedure with phenylboronic acid (PBA), the determination was achieved by isotope dilution GC-MS using isotope-labeled 3-MCPD and 3-MCPD ester as internal standards. The method was validated for various foodstuffs like bakery products, meat and fish products, and soups as well as seasonings with LOD of 1-2 microg/kg (3-MCPD) and 6 microg/kg (3-MCPD esters), respectively. Recoveries ranged within 95 +/- 9% and 96 +/- 10% at spiking levels of 15 and 25 microg/kg in all matrices for 3-MCPD and 84 +/- 9% and 85 +/- 7% at spiking levels of 0.05 mg/kg and 2 mg/kg for 3-MCPD esters. The method avoids tedious and laborious sample preparation and was successfully applied to the rapid screening of samples conforming to the EU performance criteria for methods of analysis for 3-MCPD.

Effect of lignin linkages with other plant cell wall components on in vitro and in vivo neutral detergent fiber digestibility and rate of digestion of grass forages.

PubMed

Raffrenato, E; Fievisohn, R; Cotanch, K W; Grant, R J; Chase, L E; Van Amburgh, M E

2017-10-01

The objective of this study was to correlate in vitro and in vivo neutral detergent fiber (NDF) digestibility (NDFD) with the chemical composition of forages and specific chemical linkages, primarily ester- and ether-linked para-coumaric (pCA) and ferulic acids (FA) in forages fed to dairy cattle. The content of acid detergent lignin (ADL) and its relationship with NDF does not fully explain the observed variability in NDFD. The ferulic and p-coumaric acid linkages between ADL and cell wall polysaccharides, rather than the amount of ADL, might be a better predictor of NDFD. Twenty-three forages, including conventional and brown midrib corn silages and grasses at various stages of maturity were incubated in vitro for measurement of 24-h and 96-h NDFD. Undigested and digested residues were analyzed for NDF, acid detergent fiber (ADF), ADL, and Klason lignin (KL); ester- and ether-linked pCA and FA were determined in these fractions. To determine whether in vitro observations of ester- and ether-linked pCA and FA and digestibility were similar to in vivo observations, 3 corn silages selected for digestibility were fed to 6 ruminally fistulated cows for 3 wk in 3 iso-NDF diets. Intact samples and NDF and ADF residues of diet, rumen, and feces were analyzed for ester- and ether-linked pCA and FA. From the in vitro study, the phenolic acid content (total pCA and FA) was highest for corn silages, and overall the content of ester- and ether-linked pCA and FA in both NDF and ADF residues were correlated with NDF digestibility parameters, reflecting the competitive effect of these linkages on digestibility. Also, Klason lignin and ADL were negatively correlated with ether-linked ferulic acid on an NDF basis. Overall, esterified FA and esterified pCA were negatively correlated with all of the measured fiber fractions on both a dry matter and an NDF basis. The lignin content of the plant residues and chemical linkages explained most of the variation in both rate and extent of NDF digestion but not uniformly among forages, ranging from 56 to 99%. The results from the in vivo study were similar to the in vitro data, demonstrating the highest total-tract aNDF digestibility (70%; NDF analysis conducted with α-amylase and sodium sulfite) for cows fed the corn silage with the lowest ester- and ether-linked pCA content in the NDF fraction. In this study, digestibility of forage fiber was influenced by the linkages among lignin and the carbohydrate moieties, which vary by hybrid and species and most likely vary by the agronomic conditions under which the plant was grown. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A coumaroyl-ester-3-hydroxylase Insertion Mutant Reveals the Existence of Nonredundant meta-Hydroxylation Pathways and Essential Roles for Phenolic Precursors in Cell Expansion and Plant Growth1[W][OA

PubMed Central

Abdulrazzak, Nawroz; Pollet, Brigitte; Ehlting, Jürgen; Larsen, Kim; Asnaghi, Carole; Ronseau, Sebastien; Proux, Caroline; Erhardt, Mathieu; Seltzer, Virginie; Renou, Jean-Pierre; Ullmann, Pascaline; Pauly, Markus; Lapierre, Catherine; Werck-Reichhart, Danièle

2006-01-01

Cytochromes P450 monooxygenases from the CYP98 family catalyze the meta-hydroxylation step in the phenylpropanoid biosynthetic pathway. The ref8 Arabidopsis (Arabidopsis thaliana) mutant, with a point mutation in the CYP98A3 gene, was previously described to show developmental defects, changes in lignin composition, and lack of soluble sinapoyl esters. We isolated a T-DNA insertion mutant in CYP98A3 and show that this mutation leads to a more drastic inhibition of plant development and inhibition of cell growth. Similar to the ref8 mutant, the insertion mutant has reduced lignin content, with stem lignin essentially made of p-hydroxyphenyl units and trace amounts of guaiacyl and syringyl units. However, its roots display an ectopic lignification and a substantial proportion of guaiacyl and syringyl units, suggesting the occurrence of an alternative CYP98A3-independent meta-hydroxylation mechanism active mainly in the roots. Relative to the control, mutant plantlets produce very low amounts of sinapoyl esters, but accumulate flavonol glycosides. Reduced cell growth seems correlated with alterations in the abundance of cell wall polysaccharides, in particular decrease in crystalline cellulose, and profound modifications in gene expression and homeostasis reminiscent of a stress response. CYP98A3 thus constitutes a critical bottleneck in the phenylpropanoid pathway and in the synthesis of compounds controlling plant development. CYP98A3 cosuppressed lines show a gradation of developmental defects and changes in lignin content (40% reduction) and structure (prominent frequency of p-hydroxyphenyl units), but content in foliar sinapoyl esters is similar to the control. The purple coloration of their leaves is correlated to the accumulation of sinapoylated anthocyanins. PMID:16377748

Acidic electrolyzed water efficiently improves the flavour of persimmon (Diospyros kaki L. cv. Mopan) wine.

PubMed

Zhu, Wanqi; Zhu, Baoqing; Li, Yao; Zhang, Yanyan; Zhang, Bolin; Fan, Junfeng

2016-04-15

The ability of acidic (AcW) and alkaline electrolyzed waters (AlW) to improve the flavour of persimmon (Diospyros kaki L.) wine was evaluated. Wines made with AcW (WAcW) were significantly better than wines made with AlW or pure water (PW) in aroma, taste, and colour. Volatile analysis showed that WAcW has high alcohol and ester contents, including 2-phenylethanol, isopentanol, isobutanol, ethyl dodecanoate, phenethyl acetate, and butanedioic acid diethyl ester. The total amino acid content of persimmon slurry soaked with AcW reached 531.2 mg/l, which was much higher than those of the slurries soaked in AlW (381.3 mg/l) and PW (182.7 mg/l). The composition of major amino acids in the AcW-soaked slurry may contribute to the strong ester flavour of WAcW. This is the first report to suggest that electrolyzed functional water (EFW) can be used to improve wine flavour, leading to the possible use of EFW in food processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationship between atorvastatin dose and the harm caused by torcetrapib.

PubMed

Barter, Philip J; Rye, Kerry-Anne; Beltangady, Mohan S; Ports, William C; Duggan, William T; Boekholdt, S Matthijs; DeMicco, David A; Kastelein, John J P; Shear, Charles L

2012-11-01

Development of the cholesteryl ester transfer protein (CETP) inhibitor, torcetrapib, was halted after the ILLUMINATE trial revealed an increase in both all-cause mortality (ACM) and major cardiovascular events (MCVEs) associated with its use. We now report that the harm caused by torcetrapib was confined to those in the 10 mg atorvastatin subgroup for both ACM [hazard ratio (HR) = 2.68, 95% CI (1.58, 4.54), P < 0.0001] and MCVEs [HR = 1.41, 95% CI (1.14, 1.74), P = 0.002], with no evidence of harm when torcetrapib was coadministered with higher doses of atorvastatin. In the atorvastatin 10 mg subgroup, age, prior heart failure and stroke were significantly associated with ACM, independent of torcetrapib treatment, whereas low apoA-I, smoking, hypertension, heart failure, myocardial infarction, and stroke were independently associated with MCVEs. After adjusting for these factors, the HR associated with torcetrapib treatment in the 10 mg atorvastatin subgroup remained elevated for both ACM [HR = 2.67, 95% CI (1.57, 4.54), P < 0.001] and MCVE [HR = 1.36, 95% CI (1.10, 1.69), P = 0.005]. Thus, the harm caused by torcetrapib was confined to individuals taking atorvastatin 10 mg. The harm could not be explained by torcetrapib-induced changes in lipid levels, blood pressure, or electrolytes. It is conceivable that higher doses of atorvastatin protected against the harm caused by torcetrapib.

Mammalian Wax Biosynthesis

PubMed Central

Cheng, Jeffrey B.; Russell, David W.

2009-01-01

Wax monoesters are synthesized by the esterification of fatty alcohols and fatty acids. A mammalian enzyme that catalyzes this reaction has not been isolated. We used expression cloning to identify cDNAs encoding a wax synthase in the mouse preputial gland. The wax synthase gene is located on the X chromosome and encodes a member of the acyltransferase family of enzymes that synthesize neutral lipids. Expression of wax synthase in cultured cells led to the formation of wax monoesters from straight chain saturated, unsaturated, and polyunsaturated fatty alcohols and acids. Polyisoprenols also were incorporated into wax monoesters by the enzyme. The wax synthase had little or no ability to synthesize cholesteryl esters, diacylglycerols, or triacylglycerols, whereas other acyltransferases, including the acyl-CoA:monoacylglycerol acyltransferase 1 and 2 enzymes and the acyl-CoA:diacylglycerol acyltransferase 1 and 2 enzymes, exhibited modest wax monoester synthesis activities. Confocal light microscopy indicated that the wax synthase was localized in membranes of the endoplasmic reticulum. Wax synthase mRNA was abundant in tissues rich in sebaceous glands such as the preputial gland and eyelid and was present at lower levels in other tissues. Coexpression of cDNAs specifying fatty acyl-CoA reductase 1 and wax synthase led to the synthesis of wax monoesters. The data suggest that wax monoester synthesis in mammals involves a two step biosynthetic pathway catalyzed by fatty acyl-CoA reductase and wax synthase enzymes. PMID:15220349

Intranasal immunization with chitosan/pCETP nanoparticles inhibits atherosclerosis in a rabbit model of atherosclerosis.

PubMed

Yuan, Xiying; Yang, Xiaorong; Cai, Danning; Mao, Dan; Wu, Jie; Zong, Li; Liu, Jingjing

2008-07-04

In search of a convenient and pain-free route of administration of DNA vaccine against atherosclerosis, the plasmid pCR-X8-HBc-CETP (pCETP) encoding B-cell epitope of cholesteryl ester transfer protein C-terminal fragment displayed by Hepatitis B virus core particle was condensed with chitosan to form chitosan/pCETP nanoparticles. Cholesterol-fed rabbits were then intranasally immunized with the chitosan/pCETP nanoparticles to evaluate antiatherogenic effects. The results showed that significant serum antibodies against CETP were detected by enzyme-linked immunosorbent analysis and verified by Western blot analysis. The significant anti-CETP IgG lasted for 21 weeks in the rabbits immunized intranasally. Moreover, the atherogenic index was significantly lower compared with the saline control (5.95 versus 2.39, p<0.05). In addition, the average percentage of aortic lesions in the entire aorta area in the rabbits intranasally vaccinated with nanoparticles was 59.2% less than those treated with saline (29.0+/-10.9% versus 71.0+/-14.4%, p<0.01) and was similar to those intramuscularly injected with pCETP solution (29.0+/-10.9% versus 21.2+/-14.2%, p>0.05). Thus, chitosan/pCETP nanoparticles could significantly attenuate the progression of atherosclerosis by intranasal immunization. The results suggested that intranasal administration could be potentially developed as a vaccination route against atherosclerosis.

Neural stem cells for disease modeling of Wolman disease and evaluation of therapeutics.

PubMed

Aguisanda, Francis; Yeh, Charles D; Chen, Catherine Z; Li, Rong; Beers, Jeanette; Zou, Jizhong; Thorne, Natasha; Zheng, Wei

2017-06-28

Wolman disease (WD) is a rare lysosomal storage disorder that is caused by mutations in the LIPA gene encoding lysosomal acid lipase (LAL). Deficiency in LAL function causes accumulation of cholesteryl esters and triglycerides in lysosomes. Fatality usually occurs within the first year of life. While an enzyme replacement therapy has recently become available, there is currently no small-molecule drug treatment for WD. We have generated induced pluripotent stem cells (iPSCs) from two WD patient dermal fibroblast lines and subsequently differentiated them into neural stem cells (NSCs). The WD NSCs exhibited the hallmark disease phenotypes of neutral lipid accumulation, severely deficient LAL activity, and increased LysoTracker dye staining. Enzyme replacement treatment dramatically reduced the WD phenotype in these cells. In addition, δ-tocopherol (DT) and hydroxypropyl-beta-cyclodextrin (HPBCD) significantly reduced lysosomal size in WD NSCs, and an enhanced effect was observed in DT/HPBCD combination therapy. The results demonstrate that these WD NSCs are valid cell-based disease models with characteristic disease phenotypes that can be used to evaluate drug efficacy and screen compounds. DT and HPBCD both reduce LysoTracker dye staining in WD cells. The cells may be used to further dissect the pathology of WD, evaluate compound efficacy, and serve as a platform for high-throughput drug screening to identify new compounds for therapeutic development.

Characterization of an intraluminal differential frequency-domain photoacoustics system

NASA Astrophysics Data System (ADS)

Lashkari, Bahman; Son, Jungik; Liang, Simon; Castelino, Robin; Foster, F. Stuart; Courtney, Brian; Mandelis, Andreas

2016-03-01

Cardiovascular related diseases are ranked as the second highest cause of death in Canada. Among the most important cardiovascular diseases is atherosclerosis. Current methods of diagnosis of atherosclerosis consist of angiography, intravascular ultrasound (IVUS) and optical coherence tomography (OCT). None of these methods possesses adequate sensitivity, as the ideal technique should be capable of both depth profiling, as well as functional imaging. An alternative technique is photoacoustics (PA) which can perform deep imaging and spectroscopy. The presented study explores the application of wavelength-modulated differential photoacoustic radar (WM-DPAR) for characterizing arterial vessels. The wavelength-modulated differential photoacoustic technique was shown to be able to substantially increase the dynamic range and sensitivity of hemoglobin oxygenation level detection. In this work the differential PA technique was used with a very high frequency modulation range. To perform spectroscopic PA imaging, at least two wavelengths are required. The selected wavelengths for this work are 1210 nm and 980 nm. 1210 nm corresponds to the maximum optical absorption coefficient of cholesterol and cholesteryl esters which are the main constituents of plaques. Since water, elastin and collagen also have high absorption coefficients at 1210 nm, this wavelength alone cannot provide very high sensitivity and specificity. The additional wavelength, 980 nm corresponds to high absorption coefficient of those constituents of healthy artery tissue. The simultaneous application of the abovementioned wavelengths can provide higher sensitivity and improved specificity in detecting lipids in the arterial vessels.

Effects of anabolic androgenic steroids on chylomicron metabolism.

PubMed

Morikawa, Aleksandra T; Maranhão, Raul C; Alves, Maria-Janieire N N; Negrão, Carlos E; da Silva, Jeferson L; Vinagre, Carmen G C

2012-11-01

To evaluate the effects of anabolic androgenic steroids (AAS) on chylomicron metabolism. An artificial lipid emulsion labeled with radioactive cholesteryl ester (CE) and triglycerides (TG) mimicking chylomicrons was intravenously injected into individuals who regularly weight trained and made regular use of AAS (WT+AAS group), normolipidemic sedentary individuals (SDT group) and individuals who also regularly weight trained but did not use AAS (WT group). Fractional clearance rates (FCR) were determined by compartmental analysis for emulsion plasma decay curves. FCR-CE for the WT+AAS group was reduced (0.0073 ± 0.0079 min(-1), 0.0155 ± 0.0100 min(-1), 0.0149 ± 0.0160 min(-1), respectively; p<0.05), FCR-TG was similar for both the WT and SDT groups. HDL-C plasma concentrations were lower in the WT+AAS group when compared to the WT and SDT groups (22 ± 13; 41 ± 7; 38 ± 13 mg/dL, respectively; p<0.001). Hepatic triglyceride lipase activity was greater in the WT+AAS group when compared to the WT and SDT groups (7243 ± 1822; 3898 ± 1232; 2058 ± 749, respectively; p<0.001). However, no difference was observed for lipoprotein lipase activity. Data strongly suggest that AAS may reduce the removal from the plasma of chylomicron remnants, which are known atherogenic factors. Copyright © 2012 Elsevier Inc. All rights reserved.

Box C/D small nucleolar RNA (snoRNA) U60 regulates intracellular cholesterol trafficking.

PubMed

Brandis, Katrina A; Gale, Sarah; Jinn, Sarah; Langmade, Stephen J; Dudley-Rucker, Nicole; Jiang, Hui; Sidhu, Rohini; Ren, Aileen; Goldberg, Anna; Schaffer, Jean E; Ory, Daniel S

2013-12-13

Mobilization of plasma membrane (PM) cholesterol to the endoplasmic reticulum is essential for cellular cholesterol homeostasis. The mechanisms regulating this retrograde, intermembrane cholesterol transfer are not well understood. Because mutant cells with defects in PM to endoplasmic reticulum cholesterol trafficking can be isolated on the basis of resistance to amphotericin B, we conducted an amphotericin B loss-of-function screen in Chinese hamster ovary (CHO) cells using insertional mutagenesis to identify genes that regulate this trafficking mechanism. Mutant line A1 displayed reduced cholesteryl ester formation from PM-derived cholesterol and increased de novo cholesterol synthesis, indicating a deficiency in retrograde cholesterol transport. Genotypic analysis revealed that the A1 cell line contained one disrupted allele of the U60 small nucleolar RNA (snoRNA) host gene, resulting in haploinsufficiency of the box C/D snoRNA U60. Complementation and mutational studies revealed the U60 snoRNA to be the essential feature from this locus that affects cholesterol trafficking. Lack of alteration in predicted U60-mediated site-directed methylation of 28 S rRNA in the A1 mutant suggests that the U60 snoRNA modulates cholesterol trafficking by a mechanism that is independent of this canonical function. Our study adds to a growing body of evidence for participation of small noncoding RNAs in cholesterol homeostasis and is the first to implicate a snoRNA in this cellular function.

Associations of systemic sphingolipids with measures of hepatic function in liver cirrhosis are related to cholesterol.

PubMed

Krautbauer, Sabrina; Wiest, Reiner; Liebisch, Gerhard; Buechler, Christa

2017-07-01

Lipoprotein particles are composed of various lipid classes including cholesterol and sphingolipids, and are low in serum of patients with liver cirrhosis. Hepatic decompensation is associated with a further decline of lipoproteins. Aim of the present work was to evaluate whether ceramide and sphingomyelin species are similarly changed in patients with liver cirrhosis and whether these variations are related to systemic cholesterol levels. In a cohort of 45 patients suffering from liver cirrhosis, cholesteryl ester species and subsequently total cholesterol were identified to be negatively associated with model of end stage liver disease (MELD) score. Indeed, the negative correlations of ceramide (Cer) and sphingomyelin (SM) species with MELD score, bilirubin and anti-thrombin 3 were non-significant after adjustment for cholesterol. Cer/SM ratios of species with identical acyl chains were not related to Child-Pugh or MELD score indicating that both lipids are comparably changed. Further, cholesterol levels and concentrations of all sphingolipids measured were similar in systemic, hepatic vein and portal vein blood. Cholesterol and distinct sphingolipids were similar before and 3 months after insertion of a transjugular intrahepatic portosystemic shunt while hexosylceramide 24:1 was significantly induced. It is concluded that analysis of distinct systemic sphingolipid species is not superior to measurement of cholesterol as non-invasive marker of hepatic injury in patients with liver cirrhosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Multilevel systems biology modeling characterized the atheroprotective efficiencies of modified dairy fats in a hamster model.

PubMed

Martin, Jean-Charles; Berton, Amélie; Ginies, Christian; Bott, Romain; Scheercousse, Pierre; Saddi, Alessandra; Gripois, Daniel; Landrier, Jean-François; Dalemans, Daniel; Alessi, Marie-Christine; Delplanque, Bernadette

2015-09-01

We assessed the atheroprotective efficiency of modified dairy fats in hyperlipidemic hamsters. A systems biology approach was implemented to reveal and quantify the dietary fat-related components of the disease. Three modified dairy fats (40% energy) were prepared from regular butter by mixing with a plant oil mixture, by removing cholesterol alone, or by removing cholesterol in combination with reducing saturated fatty acids. A plant oil mixture and a regular butter were used as control diets. The atherosclerosis severity (aortic cholesteryl-ester level) was higher in the regular butter-fed hamsters than in the other four groups (P < 0.05). Eighty-seven of the 1,666 variables measured from multiplatform analysis were found to be strongly associated with the disease. When aggregated into 10 biological clusters combined into a multivariate predictive equation, these 87 variables explained 81% of the disease variability. The biological cluster "regulation of lipid transport and metabolism" appeared central to atherogenic development relative to diets. The "vitamin E metabolism" cluster was the main driver of atheroprotection with the best performing transformed dairy fat. Under conditions that promote atherosclerosis, the impact of dairy fats on atherogenesis could be greatly ameliorated by technological modifications. Our modeling approach allowed for identifying and quantifying the contribution of complex factors to atherogenic development in each dietary setup. Copyright © 2015 the American Physiological Society.

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions.

PubMed

Walker, Celia G; West, Annette L; Browning, Lucy M; Madden, Jackie; Gambell, Joanna M; Jebb, Susan A; Calder, Philip C

2015-08-03

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0-4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%-64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.

Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport

PubMed Central

Fernández-Suárez, María E.; Escolà-Gil, Joan C.; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A.; Martínez-Botas, Javier; Gómez-Coronado, Diego

2016-01-01

Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [3H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [3H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

Hexadecenoic fatty acid isomers: a chemical biology approach for human plasma biomarker development.

PubMed

Sansone, Anna; Melchiorre, Michele; Chatgilialoglu, Chryssostomos; Ferreri, Carla

2013-11-18

Hexadecenoic fatty acids are monounsaturated lipid components, which are interesting targets of plasma lipidomic studies and biomarker development. The main positional isomers, palmitoleic (9-cis-16:1) and sapienic acids (6-cis-16:1), have an endogenous origin from palmitic acid, the former being recognized as a component of adipose tissue with signaling activity, whereas the latter is mainly reported as a component of sebum. The trans 16:1 isomers are attributed so far to dietary sources of industrial and dairy fats, whereas the endogenous formation due to the free radical-mediated isomerization can represent an emerging, yet unexplored, pathway connected to cellular stress. Herein, we report a chemical biology approach for the development of hexadecenoic fatty acids as plasma biomarkers, with the first synthesis of 6-trans-16:1 and the efficient analytical setup with unambiguous assignment of 16:1 double bond position and geometry, which was applied to human commercial LDL and plasma cholesteryl esters. Sapienic acid was identified together with its geometrical trans isomer for the first time. The quantitation of hexadecenoic fatty acid isomers evidenced their different levels in the two lipid classes and LDL fractions, making us foresee interesting applications to the metabolic evaluation of fatty acid pathways. These findings open new perspectives for plasma lipidomics involving monounsaturated fatty acids, highlighting future developments for their evaluation in different health conditions including free radical stress.

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions

PubMed Central

Walker, Celia G.; West, Annette L.; Browning, Lucy M.; Madden, Jackie; Gambell, Joanna M.; Jebb, Susan A.; Calder, Philip C.

2015-01-01

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0–4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%–64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology. PMID:26247960

β-CD-dextran polymer for efficient sequestration of cholesterol from phospholipid bilayers: Mechanistic and safe-toxicity investigations.

PubMed

Stelzl, Dominik; Nielsen, Thorbjørn Terndrup; Hansen, Terkel; di Cagno, Massimiliano

2015-12-30

The aim of this work was to investigate the suitability of β-cyclodextrin-dextran (BCD-dextran) polymer as cholesterol sequestering agent in vitro. For this purpose, BCD-dextran-cholesterol complexation was studied by phase solubility studies as well as with a specifically designed in vitro model based on giant unilamellar vesicles (GUVs) to evaluate the ability of this polymer to sequestrate cholesterol from phospholipid bilayers. Cholesterol-sequestering ability of BCD-dextran was also investigated on different cell lines relevant for the hematopoietic system and results were correlated to cells toxicity. BCD-dextran polymer was capable of extracting significant amount of cholesterol from phospholipid bilayers and to a higher extent in comparison to available β-cyclodextrins (BCDs). The ability of BCD-dextran in sequestering cholesterol resulted also very high on cell lines relevant for the hematopoietic system. Moreover, BCD-dextran resulted less toxic on cell cultures due to higher selectivity in sequestering cholesterol in comparison to MBCD (that sequestrated also significant amounts of cholesteryl esters). In conclusion, BCD-dextran resulted an extremely efficient cholesterol-sequestering agent and BCD-dextran resulted more selective to cholesterol extraction in comparison to other BCDs (therefore of lower cytotoxicity). This phenomenon might play a key role to develop an efficient treatment for hypercholesterolemia based on cholesterol segregation. Copyright © 2015 Elsevier B.V. All rights reserved.

Liver-specific inhibition of acyl-coenzyme a:cholesterol acyltransferase 2 with antisense oligonucleotides limits atherosclerosis development in apolipoprotein B100-only low-density lipoprotein receptor-/- mice.

PubMed

Bell, Thomas A; Brown, J Mark; Graham, Mark J; Lemonidis, Kristina M; Crooke, Rosanne M; Rudel, Lawrence L

2006-08-01

The purpose of this study was to determine the effects of liver-specific inhibition of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) on the development of hypercholesterolemia and atherosclerosis in mice. Apolipoprotein B100-only low-density lipoprotein (LDL) receptor-/- mice were given saline, a nontargeting control antisense oligonucleotide (ASO), or ASOs targeting ACAT2 biweekly for a period spanning 16 weeks. Mice treated with ACAT2 targeting ASOs had liver-specific reduction in ACAT2 mRNA, yet intestinal ACAT2 and cholesterol absorption was left undisturbed. ASO-mediated knockdown of ACAT2 resulted in reduction of total plasma cholesterol, increased levels of plasma triglyceride, and a shift in LDL cholesteryl ester (CE) fatty acid composition from mainly saturated and monounsaturated to polyunsaturated fatty acid enrichment. Furthermore, the liver-specific depletion of ACAT2 resulted in protection against diet-induced hypercholesterolemia and aortic CE deposition. This is the first demonstration that specific pharmacological inhibition of ACAT2, without affecting ACAT1, is atheroprotective. Hepatic ACAT2 plays a critical role in driving the production of atherogenic lipoproteins, and therapeutic interventions, such as the ACAT2-specific ASOs used here, which reduce acyltransferase 2 (ACAT2) function in the liver without affecting ACAT1, may provide clinical benefit for cardiovascular disease prevention.

Carotenoids in Fish. XXXII. Content of carotenoids in eggs utilized in the form of caviar.

PubMed

Czeczuga, B

1982-01-01

The author has investigated the carotenoids in the eggs utilized in form of caviar of 4 species of fishes. By means of columnar and thin-layer chromatography, the following carotenoids were found to be present: beta-carotene, beta-cryptoxanthin, echinenone, canthaxanthin, lutein, tunaxanthin, isozeaxanthin, zeaxanthin, salmoxanthin, adobixanthin, adonixanthin ester, astaxanthin and astaxanthin ester. The total carotenoid varied from 0.229 (Th. chlacogramma) to 1.669 microgram/g fresh weight (O. nerka).

Assembly of D-alanyl-lipoteichoic acid in Lactobacillus casei: mutants deficient in the D-alanyl ester content of this amphiphile

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

Ntamere, A.S.; Taron, D.J.; Neuhaus, F.C.

D-Alanyl-lipoteichoic acid (D-alanyl-LTA) from Lactobacillus casei ATCC 7469 contains a poly(glycerophosphate) moiety that is acylated with D-alanyl ester residues. The physiological function of these residues is not well understood. Five mutant strains of this organism that are deficient in the esters of this amphiphile were isolated and characterized. When compared with the parent, strains AN-1 and AN-4 incorporated less than 10% of D-(/sup 14/C)alanine into LTA, whereas AN-2, AN-3, and AN-5 incorporated 50%. The synthesis of D-(/sup 14/C)alanyl-lipophilic LTA was virtually absent in the first group and was approximately 30% in the second group. The mutant strains synthesized and selectedmore » the glycolipid anchor for LTA assembly. In addition, all of the strains synthesized the poly(glycerophosphate) moiety of LTA to the same extent as did the parent or to a greater extent. It was concluded that the membranes from the mutant strains AN-1 and AN-4 are defective for D-alanylation of LTA even though acceptor LTA is present. Mutant strains AN-2 and AN-3 appear to be partially deficient in the amount of the D-alanine-activating enzyme. Aberrant morphology and defective cell separation appear to result from this deficiency in D-alanyl ester content.« less

Analysis of Chemical Signatures of Alkaliphiles using Fatty Acid Methyl Ester Analysis

PubMed Central

Sreenivasulu, Basha; Paramageetham, Chinthala; Sreenivasulu, Dasari; Suman, Bukke; Umamahesh, Katike; Babu, Gundala Prasada

2017-01-01

Background: Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. Materials and Methods: To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS) analysis. Results: The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl) ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. Conclusions: These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic. PMID:28717333

Experimental studies on natural aspirated diesel engine fuelled with corn seed oil methyl ester as a bio-diesel.

NASA Astrophysics Data System (ADS)

Rama Krishna Reddy, E.; Dhana Raju, V.

2018-03-01

This paper evaluates the possibilities of using corn seed oil methyl ester as a fuel for compression ignition engines. The biodiesels are contained high oxygen content, and high Cetane number, due to this properties efficiency of biodiesel is higher than diesel fuel. The experiments were conducted with different biodiesel blends of (B10, B15, B20 and B25) corn seed oil on single cylinder four stroke natural aspirated diesel engines. Performance parameters and exhaust emissions are investigated in this experimental with the blends of the corn seed oil methyl ester and diesel fuel. The test results showed that the bio-diesel blends gives improved results for brake thermal efficiency and specific fuel consumption when compared with the diesel fuel. The emissions of corn seed methyl esters follow the same trend of diesel but the smoke opacity was reduces for all blends. From the investigation, corn seed methyl ester is also having the properties similar to diesel fuel; it is biodegradable and renewable fuel, so it will be used as an alternative for diesel fuel.

A Comparison Study: The New Extended Shelf Life Isopropyl Ester PMR Technology versus The Traditional Methyl Ester PMR Approach

NASA Technical Reports Server (NTRS)

Alston, William B.; Scheiman, Daniel A.; Sivko, Gloria S.

2005-01-01

Polymerization of Monomeric Reactants (PMR) monomer solutions and carbon cloth prepregs of PMR II-50 and VCAP-75 were prepared using both the traditional limited shelf life methanol based PMR approach and a novel extended shelf life isopropanol based PMR approach. The methyl ester and isopropyl ester based PMR monomer solutions and PMR prepregs were aged for up to four years at freezer and room temperatures. The aging products formed were monitored using high pressure liquid chromatography (HPLC). The composite processing flow characteristics and volatile contents of the aged prepregs were also correlated versus room temperature storage time. Composite processing cycles were developed and six ply cloth laminates were fabricated with prepregs after various extended room temperature storage times. The composites were then evaluated for glass transition temperature (Tg), thermal decomposition temperature (Td), initial flexural strength (FS) and modulus (FM), long term (1000 hours at 316 C) thermal oxidative stability (TOS), and retention of FS and FM after 1000 hours aging at 316 C. The results for each ester system were comparable. Freezer storage was found to prevent the formation of aging products for both ester systems. Room temperature storage of the novel isopropyl ester system increased PMR monomer solution and PMR prepreg shelf life by at least an order of magnitude while maintaining composite properties.

Quantification of sterol-specific response in human macrophages using automated imaged-based analysis.

PubMed

Gater, Deborah L; Widatalla, Namareq; Islam, Kinza; AlRaeesi, Maryam; Teo, Jeremy C M; Pearson, Yanthe E

2017-12-13

The transformation of normal macrophage cells into lipid-laden foam cells is an important step in the progression of atherosclerosis. One major contributor to foam cell formation in vivo is the intracellular accumulation of cholesterol. Here, we report the effects of various combinations of low-density lipoprotein, sterols, lipids and other factors on human macrophages, using an automated image analysis program to quantitatively compare single cell properties, such as cell size and lipid content, in different conditions. We observed that the addition of cholesterol caused an increase in average cell lipid content across a range of conditions. All of the sterol-lipid mixtures examined were capable of inducing increases in average cell lipid content, with variations in the distribution of the response, in cytotoxicity and in how the sterol-lipid combination interacted with other activating factors. For example, cholesterol and lipopolysaccharide acted synergistically to increase cell lipid content while also increasing cell survival compared with the addition of lipopolysaccharide alone. Additionally, ergosterol and cholesteryl hemisuccinate caused similar increases in lipid content but also exhibited considerably greater cytotoxicity than cholesterol. The use of automated image analysis enables us to assess not only changes in average cell size and content, but also to rapidly and automatically compare population distributions based on simple fluorescence images. Our observations add to increasing understanding of the complex and multifactorial nature of foam-cell formation and provide a novel approach to assessing the heterogeneity of macrophage response to a variety of factors.

Physicochemical and histological changes in the arterial wall of nonhuman primates during progression and regression of atherosclerosis.

PubMed Central

Small, D M; Bond, M G; Waugh, D; Prack, M; Sawyer, J K

1984-01-01

To identify the temporal changes occurring during progression and regression of atherosclerosis in nonhuman primates, we have studied the physicochemical and histological characteristics of arterial wall lesions during a 30-mo progression period of diet-induced hypercholesterolemia and during a 12-mo period of regression. Three groups of cynomolgous monkeys (Macaca fascicularis) were studied. Control groups were fed a basal chow diet for 18, 24, and 30 mo and were compared with progression groups that were fed a high-cholesterol-containing diet for up to 30 mo. Regression groups were fed a high-cholesterol diet for 18 mo to induce atherosclerosis and then fed monkey chow for up to 12 mo. The progression group monkeys were killed at 6, 12, 18, 24, and 30 mo, and the regression animals were killed at 24 and 30 mo (i.e., after 6 and 12 mo of being fed a noncholesterol-containing chow diet). Histology and morphometry, physical microscopy for cholesterol monohydrate crystals, foam cell and droplet melting points and chemical composition studies were completed on a large number of individual arterial lesions. Control animals had very little cholesterol ester, rare foam cells, and no extracellular cholesterol ester droplets or cholesterol crystals. During progression, the arteries first increased cholesterol ester content to produce high melting (approximately 45 degrees C) foam cell-rich lesions essentially devoid of cholesterol crystals. With time, the number of cholesterol crystals increased so that by 30 mo large numbers were present. Foam cells decreased with time but their melting temperature remained high while that of extracellular droplets fell to approximately 38 degrees C. Between 18 and 30 mo necrosis appeared and worsened. After 6-mo regression, unexpected changes occurred in the lesions. Compared with 24-mo progression, the chemical composition showed a relative increase in free cholesterol, a decrease in cholesterol ester and microscopy revealed large numbers of cholesterol crystals. Concomitantly, foam cells decreased and the melting temperature of both intra- and extracellular cholesterol ester markedly decreased. After 12-mo regression cholesterol decreased, cholesterol crystals and necrosis diminished and collagen appeared increased. Thus, during progression there is initially an increase in the number of foam cells containing very high-melting intracellular cholesterol ester droplets. By 30 mo, cholesterol crystals and necrosis dominate and high-melting foam cells appear only at lesion margins, suggesting that the initial process continues at the lesion edge. The lower melting point of extracellular esters indicates a lipid composition different from intracellular droplets. Thus, the changes observed in these animals generally reflect those predicted for progression of human atherosclerosis. During the initial 6 mo of regression, necrosis remains, the number of foam cell decreases, and cholesterol ester content decreases; however the relative proportion of free cholesterol content increases, and large numbers of cholesterol content are formed. Thus, large and rapid decreases in serum cholesterol concentration to produce regression in fact may result in the precipitation of cholesterol monohydrate and an apparent worsening of the lesions. More prolonged regression (12-mo) tends to return the lipid composition of the artery wall towards normal, partially reduces cholesterol crystals, and results in an improved but scarred intima. Images PMID:6725553

Defective macroautophagic turnover of brain lipids in the TgCRND8 Alzheimer mouse model: prevention by correcting lysosomal proteolytic deficits

PubMed Central

Stavrides, Philip; Saito, Mitsuo; Kumar, Asok; Rodriguez-Navarro, Jose A.; Pawlik, Monika; Huo, Chunfeng; Walkley, Steven U.; Saito, Mariko; Cuervo, Ana M.

2014-01-01

Autophagy, the major lysosomal pathway for the turnover of intracellular organelles is markedly impaired in neurons in Alzheimer’s disease and Alzheimer mouse models. We have previously reported that severe lysosomal and amyloid neuropathology and associated cognitive deficits in the TgCRND8 Alzheimer mouse model can be ameliorated by restoring lysosomal proteolytic capacity and autophagy flux via genetic deletion of the lysosomal protease inhibitor, cystatin B. Here we present evidence that macroautophagy is a significant pathway for lipid turnover, which is defective in TgCRND8 brain where lipids accumulate as membranous structures and lipid droplets within giant neuronal autolysosomes. Levels of multiple lipid species including several sphingolipids (ceramide, ganglioside GM3, GM2, GM1, GD3 and GD1a), cardiolipin, cholesterol and cholesteryl esters are elevated in autophagic vacuole fractions and lysosomes isolated from TgCRND8 brain. Lipids are localized in autophagosomes and autolysosomes by double immunofluorescence analyses in wild-type mice and colocalization is increased in TgCRND8 mice where abnormally abundant GM2 ganglioside-positive granules are detected in neuronal lysosomes. Cystatin B deletion in TgCRND8 significantly reduces the number of GM2-positive granules and lowers the levels of GM2 and GM3 in lysosomes, decreases lipofuscin-related autofluorescence, and eliminates giant lipid-containing autolysosomes while increasing numbers of normal-sized autolysosomes/lysosomes with reduced content of undigested components. These findings have identified macroautophagy as a previously unappreciated route for delivering membrane lipids to lysosomes for turnover, a function that has so far been considered to be mediated exclusively through the endocytic pathway, and revealed that autophagic-lysosomal dysfunction in TgCRND8 brain impedes lysosomal turnover of lipids as well as proteins. The amelioration of lipid accumulation in TgCRND8 by removing cystatin B inhibition on lysosomal proteases suggests that enhancing lysosomal proteolysis improves the overall environment of the lysosome and its clearance functions, which may be possibly relevant to a broader range of lysosomal disorders beyond Alzheimer’s disease. PMID:25270989

Hexadecenoic Fatty Acid Isomers in Human Blood Lipids and Their Relevance for the Interpretation of Lipidomic Profiles

PubMed Central

Sansone, Anna; Tolika, Evanthia; Louka, Maria; Sunda, Valentina; Deplano, Simone; Melchiorre, Michele; Anagnostopoulos, Dimitrios; Chatgilialoglu, Chryssostomos; Formisano, Cesare; Di Micco, Rosa; Faraone Mennella, Maria Rosaria; Ferreri, Carla

2016-01-01

Monounsaturated fatty acids (MUFA) are emerging health biomarkers, and in particular the ratio between palmitoleic acid (9cis-16:1) and palmitic acid (16:0) affords the delta-9 desaturase index that is increased in obesity. Recently, other positional and geometrical MUFA isomers belonging to the hexadecenoic family (C16 MUFA) were found in circulating lipids, such as sapienic acid (6cis-16:1), palmitelaidic acid (9trans-16:1) and 6trans-16:1. In this work we report: i) the identification of sapienic acid as component of human erythrocyte membrane phospholipids with significant increase in morbidly obese patients (n = 50) compared with age-matched lean controls (n = 50); and ii) the first comparison of erythrocyte membrane phospholipids (PL) and plasma cholesteryl esters (CE) in morbidly obese patients highlighting that some of their fatty acid levels have opposite trends: increases of both palmitic and sapienic acids with the decrease of linoleic acid (9cis,12cis-18:2, omega-6) in red blood cell (RBC) membrane PL were reversed in plasma CE, whereas the increase of palmitoleic acid was similar in both lipid species. Consequentially, desaturase enzymatic indexes gave different results, depending on the lipid class used for the fatty acid content. The fatty acid profile of morbidly obese subjects also showed significant increases of stearic acid (C18:0) and C20 omega-6, as well as decreases of oleic acid (9cis-18:1) and docosahexaenoic acid (C22:6 omega-3) as compared with lean healthy controls. Trans monounsaturated and polyunsaturated fatty acids were also measured and found significantly increased in both lipid classes of morbidly obese subjects. These results highlight the C16 MUFA isomers as emerging metabolic marker provided that the assignment of the double bond position and geometry is correctly performed, thus identifying the corresponding lipidomic pathway. Since RBC membrane PL and plasma CE have different fatty acid trends, caution must also be used in the choice of lipid species for the interpretation of lipidomic profiles. PMID:27045677

Hexadecenoic Fatty Acid Isomers in Human Blood Lipids and Their Relevance for the Interpretation of Lipidomic Profiles.

PubMed

Sansone, Anna; Tolika, Evanthia; Louka, Maria; Sunda, Valentina; Deplano, Simone; Melchiorre, Michele; Anagnostopoulos, Dimitrios; Chatgilialoglu, Chryssostomos; Formisano, Cesare; Di Micco, Rosa; Faraone Mennella, Maria Rosaria; Ferreri, Carla

2016-01-01

Monounsaturated fatty acids (MUFA) are emerging health biomarkers, and in particular the ratio between palmitoleic acid (9cis-16:1) and palmitic acid (16:0) affords the delta-9 desaturase index that is increased in obesity. Recently, other positional and geometrical MUFA isomers belonging to the hexadecenoic family (C16 MUFA) were found in circulating lipids, such as sapienic acid (6cis-16:1), palmitelaidic acid (9trans-16:1) and 6trans-16:1. In this work we report: i) the identification of sapienic acid as component of human erythrocyte membrane phospholipids with significant increase in morbidly obese patients (n = 50) compared with age-matched lean controls (n = 50); and ii) the first comparison of erythrocyte membrane phospholipids (PL) and plasma cholesteryl esters (CE) in morbidly obese patients highlighting that some of their fatty acid levels have opposite trends: increases of both palmitic and sapienic acids with the decrease of linoleic acid (9cis,12cis-18:2, omega-6) in red blood cell (RBC) membrane PL were reversed in plasma CE, whereas the increase of palmitoleic acid was similar in both lipid species. Consequentially, desaturase enzymatic indexes gave different results, depending on the lipid class used for the fatty acid content. The fatty acid profile of morbidly obese subjects also showed significant increases of stearic acid (C18:0) and C20 omega-6, as well as decreases of oleic acid (9cis-18:1) and docosahexaenoic acid (C22:6 omega-3) as compared with lean healthy controls. Trans monounsaturated and polyunsaturated fatty acids were also measured and found significantly increased in both lipid classes of morbidly obese subjects. These results highlight the C16 MUFA isomers as emerging metabolic marker provided that the assignment of the double bond position and geometry is correctly performed, thus identifying the corresponding lipidomic pathway. Since RBC membrane PL and plasma CE have different fatty acid trends, caution must also be used in the choice of lipid species for the interpretation of lipidomic profiles.

Bifunctional heterogeneous catalysts from oil palm empty fruit bunches ash and alum for biodiesel synthesis simultaneously

NASA Astrophysics Data System (ADS)

Astar, Ismail; Usman, Thamrin; Wahyuni, Nelly; Rudiyansyah, Alimuddin, Andi Hairil

2017-03-01

Free fatty acids (FFA) contained in crude palm oil (CPO) and sludge oil has been used as the base material of biodiesel with the aid of a catalyst in the transesterification and esterification reactions. This study aims to synthesize and characterize bifunctional catalysts were synthesized from the ashes of palm empty fruit bunches (EFB) and alum based on the analysis of XRD, XRF and acidity test. Bifunctional catalyst obtained was used as a catalyst to production of biodiesel with different levels of FFA. The optimum ratio alum added was 0.2 mol at 3 hours of reaction time and 3% of catalyst by the FFA samples were used 67,40%. The catalyst with optimum alum mole variations subsequently used on samples with varying levels of FFA, namely 1.29%, 4.98%, 29.21%, 67.40% and 74.47%. Optimum conversion of methyl ester in the esterification reaction occurs in the sample with 67.40% FFA content, which reached 86.17%, while the conversion of methyl ester transesterification process optimum amounted to 45.70% in the samples with 4.98% FFA content. Methyl ester produced has a refractive index of 1.448 (29.8 ° C), density of 0.883 g / mL (25 °C) and a viscosity of 8.933 cSt (25 ° C). The results of GC-MS analysis showed that the main composition of methyl ester result of esterification of sludge oil methyl palmitate (36.84%), while the CPO transesterification shows the main composition of methyl ester is methyl oleic (38.87%). Based on the research results, the catalyst synthesized from alum and EFB ash can be used as a Bifunctional catalysts for biodiesel synthesis.

Direct determination of 3-chloropropanol esters in edible vegetable oils using high resolution mass spectrometry (HRMS-Orbitrap).

PubMed

Graziani, Giulia; Gaspari, Anna; Chianese, Donato; Conte, Lanfranco; Ritieni, Alberto

2017-11-01

A series of refined edible oils derived from mixed seeds, peanuts, corn, sunflower and palm obtained from the local supermarket were analyzed for their content of 3-MCPD esters. A direct analytical method for the determination of 3-monochloropropane-1,2-diol esters (3-MCPD esters) was applied to investigate the major MCPD esters found in common edible oils; in particular seven types of monoesters and eleven types of diesters were detected. The limits of detection (LODs) for monoesters and diesters of 3-MCPD were in the range of 0.079-12.678 µg kg -1 and 0.033-18.610 µg kg -1 in edible oils, and the ranges of limits of quantitation (LOQs) were 0.979-38.035 µg kg -1 and 0.100-55 µg kg -1 , respectively. The recoveries of 3-MCPD esters from oil samples were in the range of 80-100%, with RSD ranging between 1.9 and 11.8%. The concentration levels of total 3-MCPD diesters in vegetable oil samples were in the range from 0.106 up to 3.444 μg g -1 whereas total monoesters ranged from 0.005 up to 1.606 μg g -1 .

Tum1 is involved in the metabolism of sterol esters in Saccharomyces cerevisiae.

PubMed

Uršič, Katja; Ogrizović, Mojca; Kordiš, Dušan; Natter, Klaus; Petrovič, Uroš

2017-08-22

The only hitherto known biological role of yeast Saccharomyces cerevisiae Tum1 protein is in the tRNA thiolation pathway. The mammalian homologue of the yeast TUM1 gene, the thiosulfate sulfurtransferase (a.k.a. rhodanese) Tst, has been proposed as an obesity-resistance and antidiabetic gene. To assess the role of Tum1 in cell metabolism and the putative functional connection between lipid metabolism and tRNA modification, we analysed evolutionary conservation of the rhodanese protein superfamily, investigated the role of Tum1 in lipid metabolism, and examined the phenotype of yeast strains expressing the mouse homologue of Tum1, TST. We analysed evolutionary relationships in the rhodanese superfamily and established that its members are widespread in bacteria, archaea and in all major eukaryotic groups. We found that the amount of sterol esters was significantly higher in the deletion strain tum1Δ than in the wild-type strain. Expression of the mouse TST protein in the deletion strain did not rescue this phenotype. Moreover, although Tum1 deficiency in the thiolation pathway was complemented by re-introducing TUM1, it was not complemented by the introduction of the mouse homologue Tst. We further showed that the tRNA thiolation pathway is not involved in the regulation of sterol ester content in S. cerevisiae, as overexpression of the tE UUC , tK UUU and tQ UUG tRNAs did not rescue the lipid phenotype in the tum1Δ deletion strain, and, additionally, deletion of the key gene for the tRNA thiolation pathway, UBA4, did not affect sterol ester content. The rhodanese superfamily of proteins is widespread in all organisms, and yeast TUM1 is a bona fide orthologue of mammalian Tst thiosulfate sulfurtransferase gene. However, the mouse TST protein cannot functionally replace yeast Tum1 protein, neither in its lipid metabolism-related function, nor in the tRNA thiolation pathway. We show here that Tum1 protein is involved in lipid metabolism by decreasing the sterol ester content in yeast cells, and that this function of Tum1 is not exerted through the tRNA thiolation pathway, but through another, currently unknown pathway.

Preparation and blood compatibility of polysiloxane/liquid-crystal composite membranes.

PubMed

Li, L; Tu, M; Mou, S; Zhou, C

2001-10-01

Polysiloxane/liquid crystal composite membrane was first suggested to be used as biomaterials. In this work, the polydimethyl-methylhydrosiloxane and polydimethyl-methylethylenesilosiane, as a substrate, were blended with cholesteryl oleyl carbonate (COC) in tetrahydrofuran, and then crosslinked into membranes on glass plates by means of the platinum catalyst at 110 degrees C for 20 min. The effects of the liquid-crystal content in composite membranes on the formation of liquid-crystal phase were verified by the observation of optical polarization microscopy. The relationship between the morphology of the composite membranes and blood compatibility was identified by the dynamic blood-clotting tests, haemolysis ratio measurement, platelet adhesion and SEM observation. The results show that the blood-compatibility of composite membranes with the concentration of liquid crystal 20, 30% (wt) is more excellent than that of other composite membranes.

Comparative evaluation of an ISO 3632 method and an HPLC-DAD method for safranal quantity determination in saffron.

PubMed

García-Rodríguez, M Valle; López-Córcoles, Horacio; Alonso, Gonzalo L; Pappas, Christos S; Polissiou, Moschos G; Tarantilis, Petros A

2017-04-15

The aim of this work was a comparison of the ISO 3632 (2011) method and an HPLC-DAD method for safranal quantity determination in saffron. Samples from different origins were analysed by UV-vis according to ISO 3632 (2011) and by HPLC-DAD. Both methods were compared, and there was no correlation between the safranal content obtained by UV-vis and HPLC-DAD. An over-estimation in the UV-vis experiment was observed, which was related to the cis-crocetin esters content, as well as other compounds. The results demonstrated that there was no relationship between ISO quality categories and safranal content using HPLC-DAD. Therefore, HPLC-DAD might be preferable to UV-vis for determining the safranal content and the classification of saffron for commercial purposes. In addition, HPLC-DAD was adequate for determining the three foremost parameters that define the quality of saffron (crocetin esters, picrocrocin and safranal); therefore, this approach could be included in the ISO 3632 method (2011). Copyright © 2016 Elsevier Ltd. All rights reserved.

Foliar Fatty Acids and Sterols of Soybean Field Fumigated with SO2

PubMed Central

Grunwald, Claus

1981-01-01

Sixty-day-old soybean plants were exposed in the field to 78.7 parts per one-hundred million of SO2 in an open-air fumigation system for 20 days. Leaves from the top one-fourth and bottom one-fourth of the plants were analyzed for chlorophyll, free fatty acids, fatty acid esters, polar lipid fatty acids, and sterols. Fumigated plants had a lower chlorophyll, free fatty acid, and polar lipid content, but a higher fatty acid ester content. Of the individual fatty acids, linoleic and linolenic acid increased with SO2 fumigation while palmitic acid decreased. SO2 fumigations had only a minor effect on leaf sterols. In general, the lower, more mature leaves showed a greater response to SO2 exposure. PMID:16662015

Preparation and characterization of bio-diesels from various bio-oils.

PubMed

Lang, X; Dalai, A K; Bakhshi, N N; Reaney, M J; Hertz, P B

2001-10-01

Methyl, ethyl, 2-propyl and butyl esters were prepared from canola and linseed oils through transesterification using KOH and/ or sodium alkoxides as catalysts. In addition, methyl and ethyl esters were prepared from rapeseed and sunflower oils using the same catalysts. Chemical composition of the esters was determined by HPLC for the class of lipids and by GC for fatty acid compositions. The bio-diesel esters were characterized for their physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. Methyl and ethyl esters prepared from a particular vegetable oil had similar viscosities, cloud points and pour points, whereas methyl, ethyl, 2-propyl and butyl esters derived from a particular vegetable oil had similar gross heating values. However, their densities, which were 2 7% higher than those of diesel fuels, statistically decreased in the order of methyl approximately 2-propyl > ethyl > butyl esters. Butyl esters showed reduced cloud points (-6 degrees C to -10 degrees C) and pour points (-13 degrees C to -16 degrees C) similar to those of summer diesel fuel having cloud and pour points of -8 degrees C and -15 degrees C, respectively. The viscosities of bio-diesels (3.3-7.6 x 10(-4) Pa s at 40 degrees C) were much less than those of pure oils (22.4-45.1 x 10(-4) Pa s at 40 degrees C) and were twice those of summer and winter diesel fuels (3.50 and 1.72 x 10(-4) Pa s at 40 degrees C), and their gross heat contents of approximately 40 MJ/kg were 11% less than those of diesel fuels (approximately 45 MJ/kg). For different esters from the same vegetable oil, methyl esters were the most volatile, and the volatility decreased as the alkyl group grew bulkier. However, the bio-diesels were considerably less volatile than the conventional diesel fuels.

Bio-detoxification of phorbol esters and other anti-nutrients of Jatropha curcas seed cake by fungal cultures using solid-state fermentation.

PubMed

Sharath, B S; Mohankumar, B V; Somashekar, D

2014-03-01

Jatropha seed cake, a byproduct after biodiesel extraction, has several anti-nutrients and toxins. Solid-state fermentation was carried out for the detoxification of the Jatropha seed cake (JSC) using different fungal cultures. The reduction in the anti-nutritional components such as tannins, phytates, saponins, lectin and protease inhibitor, and phorbol esters on 6th, 9th, and 12th day of fermentation was analyzed. The phorbol ester content in the unfermented JSC was 0.83 mg/g, and the maximum degradation of phorbol esters to the extent of 75% was observed in the case of JSC fermented with Cunninghamella echinulata CJS-90. The phytate degradation in the fermented JSC was in the range of 65-96%. There was a gradual reduction of saponin content in the JSC from 6th to 12th day, and the reduction of saponin was in the range of 55-99% after solid-state fermentation. The trypsin inhibitor activity and lectin were 1,680 trypsin inhibitor units (TIU) per gram and 0.32 hemagglutinating unit in the unfermented JSC, respectively. Trypsin inhibitor activity and lectin could not be detected in JSC after 12th day of solid-state fermentation. Tannins accounted for 0.53% in unfermented JSC, and there was a marginal increase of tannins after solid-state fermentation. The results indicate that biological detoxification could be a promising method to reduce anti-nutritional compounds and toxins in the JSC.

Effect of heat treatment on the phenolic compounds and antioxidant capacity of citrus peel extract.

PubMed

Xu, Guihua; Ye, Xingqian; Chen, Jianchu; Liu, Donghong

2007-01-24

This paper reports the effects of heat treatment on huyou (Citrus paradisi Changshanhuyou) peel in terms of phenolic compounds and antioxidant capacity. High-performance liquid chromatography (HPLC) coupled with a photodiode array (PDA) detector was used in this study for the analysis of phenolic acids (divided into four fractions: free, ester, glycoside, and ester-bound) and flavanone glycosides (FGs) in huyou peel (HP) before and after heat treatment. The results showed that after heat treatment, the free fraction of phenolic acids increased, whereas ester, glycoside, and ester-bound fractions decreased and the content of total FGs declined (P < 0.05). Furthermore, the antioxidant activity of methanol extract of HP increased (P < 0.05), which was evaluated by total phenolics contents (TPC) assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS*+) method, and ferric reducing antioxidant power (FRAP) assay. The correlation coefficients among TPC, ABTS, FRAP assay, and total cinnamics and benzoics (TCB) in the free fraction were significantly high (P < 0.05), which meant that the increase of total antioxidant capacity (TAC) of HP extract was due at least in part to the increase of TCB in free fraction. In addition, FGs may be destroyed when heated at higher temperature for a long time (for example, 120 degrees C for 90 min or 150 degrees C for 30 min). Therefore, it is suggested that a proper and reasonable heat treatment could be used to enhance the antioxidant capacity of citrus peel.

New fluoroprostaglandin F(2alpha) derivatives with prostanoid FP-receptor agonistic activity as potent ocular-hypotensive agents.

PubMed

Nakajima, Tadashi; Matsugi, Takeshi; Goto, Wakana; Kageyama, Masaaki; Mori, Nobuaki; Matsumura, Yasushi; Hara, Hideaki

2003-12-01

To find new prostanoid FP-receptor agonists possessing potent ocular-hypotensive effects with minimal side effects, we evaluated the agonistic activities of newly synthesized prostaglandin F(2alpha) derivatives for the prostanoid FP-receptor both in vitro and in vivo. The iris constrictions induced by the derivatives and their effects on melanin content were examined using cat isolated iris sphincters and cultured B16 melanoma cells, respectively. The effects of derivative ester forms on miosis and intraocular pressure (IOP) were evaluated in cats and cynomolgus monkeys, respectively. Of these derivatives, 6 out of 12 compounds were more potent iris constrictors, with EC(50) values of 0.6 to 9.4 nM, than a carboxylic acid of latanoprost (EC(50)=13.6 nM). A carboxylic acid of latanoprost (100 microM) significantly increased the melanin content of cultured B16 melanoma cells, but some 15,15-difluoro derivatives, such as AFP-157 and AFP-172, did not. Topically applied AFP-168, AFP-169 and AFP-175 (isopropyl ester, methyl ester and ethyl ester forms, respectively, of AFP-172) induced miosis in cats more potently than latanoprost. AFP-168 (0.0005%) reduced IOP to the same extent as 0.005% latanoprost (for at least 8 h). These findings indicate that 15,15-difluoroprostaglandin F(2alpha) derivatives, especially AFP-168, have more potent prostanoid FP-receptor agonistic activities than latanoprost. Hence, AFP-168 may be worthy of further evaluation as an ocular-hypotensive agent.

Enzymatic Synthesis of Refined Olive Oil-Based Structured Lipid Containing Omega -3 and -6 Fatty Acids for Potential Application in Infant Formula.

PubMed

Li, Ruoyu; Sabir, Jamal S M; Baeshen, Nabih A; Akoh, Casimir C

2015-11-01

Structured lipids (SLs) containing palmitic, docosahexaenoic (DHA), and gamma-linolenic (GLA) acids were produced using refined olive oil, tripalmitin, and ethyl esters of DHA single cell oil and GLA ethyl esters. Immobilized Lipozyme TL IM lipase was used as the biocatalyst. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, solid fat content, oxidative stability index, and melting and crystallization profiles and compared to physical blend of substrates, extracted fat from commercial infant formula (IFF), and milk fat. 49.28 mol% of palmitic acid was found at the sn-2 position of SL TAG and total DHA and GLA composition were 0.73 and 5.00 mol%, respectively. The total oleic acid content was 36.13 mol% which was very close to the 30.49% present in commercial IFF. Comparable solid fat content profiles were also found between SLs and IFF. The SLs produced have potential for use in infant formulas. © 2015 Institute of Food Technologists®

Quantitative analysis of anti-inflammatory and radical scavenging triterpenoid esters in evening primrose seeds.

PubMed

Zaugg, Janine; Potterat, Olivier; Plescher, Andreas; Honermeier, Bernd; Hamburger, Matthias

2006-09-06

Lipophilic triterpenoidal esters with radical scavenging and cyclooxygenase inhibitory properties were recently found in cold-pressed, nonraffinated evening primrose oil (EPO). A quantitative assay for the analysis of 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid in evening primrose seeds was developed and validated. Extraction efficiency >99% was achieved by means of pressurized liquid extraction with two extraction cycles and 80% (v/v) ethanol at 120 degrees C. Analysis of esters was by normal-phase high-performance liquid chromatography on a Diol column and hexane/ethyl acetate (containing 0.1% formic acid) (65:35) as the eluent. The analytes were determined without further prepurification. Seeds from defined cultures of Oenothera biennis, Oenothera lamarckiana, and Oenothera ammophila, grown under identical conditions, were analyzed. The cultures originated from seeds from eight collections in the wild and from selections from five cultivars. The content of total triterpenoidal esters in seeds varied between 1.34 and 2.78 mg/g. Three types of qualitative patterns were observed for the triterpenoidal esters. The influence of different harvest times and plant treatments was studied with the cultivar Anothera. Variations between 1.5 and 2.3 mg/g were found.

Synthesis and characterization of a thermo-sensitive poly( N-methyl acryloylglycine methyl ester) used as a drug release carrier

NASA Astrophysics Data System (ADS)

Deng, Kui-Lin; Zhong, Hai-Bin; Jiao, Yi-Suo; Fan, Ting; Qiao, Xiao; Zhang, Peng-Fei; Ren, Xiao-Bo

2010-06-01

In this article, poly( N-methyl acryloylglycine methyl ester) (PNMAME) was prepared as a novel thermosensitive material with a lower critical solution temperature (LCST) at around 49.5°C. The chemical structures of the monomer NMAME and PNMAME were characterized by 1H NMR and IR measurements. The LCST was investigated systematically as a function of PNMAME concentration, inorganic salt solution and pH value. The results indicated that LCST of PNMAME was obviously dependent on PNMAME concentration and pH. The LCST was increased with a decrease in pH value and PNMAME concentration. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NMAME and N-acryloylglycine ethyl ester (NAGEE). The release behavior of caffeine was evaluated at different temperatures and contents of cross-linkers ( N, N-methylenebis(acrylamide) (NMBA)). The increase of cross-linker content led to a decrease in the release rate of caffeine due to higher crossing density in the hydrogel network. In addition, a faster release of caffeine from the hydrogel with 3% NMBA at 37°C was found in contrast to that at 18°C.

Engineering Potato Starch with a Higher Phosphate Content

PubMed Central

Xu, Xuan; Huang, Xing-Feng; Visser, Richard G. F.

2017-01-01

Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a carbohydrate-binding module and a dual-specificity phosphatase domain, is involved in the dephosphorylation of glycogen. To modify phosphate content and better understand starch (de)phosphorylation in storage starch, laforin was engineered and introduced into potato (cultivar Kardal). Interestingly, expression of an (engineered) laforin in potato resulted in significantly higher phosphate content of starch, and this result was confirmed in amylose-free potato genetic background (amf). Modified starches exhibited altered granule morphology and size compared to the control. About 20–30% of the transgenic lines of each series showed red-staining granules upon incubation with iodine, and contained higher phosphate content than the blue-stained starch granules. Moreover, low amylose content and altered gelatinization properties were observed in these red-stained starches. Principle component and correlation analysis disclosed a complex correlation between starch composition and starch physico-chemical properties. Ultimately, the expression level of endogenous genes involved in starch metabolism was analysed, revealing a compensatory response to the decrease of phosphate content in potato starch. This study provides a new perspective for engineering starch phosphate content in planta by making use of the compensatory mechanism in the plant itself. PMID:28056069

Release of superoxide and change in morphology by neutrophils in response to phorbol esters: antagonism by inhibitors of calcium-binding proteins

PubMed Central

1985-01-01

The ability of phorbol derivatives to function as stimulating agents for superoxide (O2-) release by guinea pig neutrophils has been evaluated and compared to the known ability of each compound to activate protein kinase C. Those that activate the kinase also stimulate O2- release, while those that are inactive with respect to the kinase have no effect on O2- release. The same correlation was observed with respect to the ability of phorbol esters to induce morphological changes in neutrophils, i.e., vesiculation and reduction in granule content. Certain phenothiazines and naphthalene sulfonamides that are known antagonists of calcium-binding proteins blocked both phorbol ester-induced O2- release and morphological changes in these cells. PMID:2993312

Optimization of an Indirect Enzymatic Method for the Simultaneous Analysis of 3-MCPD, 2-MCPD, and Glycidyl Esters in Edible Oils.

PubMed

Koyama, Kazuo; Miyazaki, Kinuko; Abe, Kousuke; Ikuta, Keiich; Egawa, Yoshitsugu; Kitta, Tadashi; Kido, Hirotsugu; Sano, Takashi; Takahashi, Yukinari; Nezu, Toru; Nohara, Hidenori; Miyashita, Takashi; Yada, Hiroshi; Yamazaki, Kumiko; Watanabe, Yomi

2015-01-01

We developed a novel, indirect enzymatic method for the analysis of fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPD), 2-monochloro-1,3-propanediol (2-MCPD), and glycidol (Gly) in edible oils and fats. Using this method, the ester analytes were rapidly cleavaged by Candida rugosa lipase at room temperature for 0.5 h. As a result of the simultaneous hydrolysis and bromination steps, 3-MCPD esters, 2-MCPD esters, and glycidyl esters were converted to free 3-MCPD, 2-MCPD, and 3-monobromo-1,2-propanediol (3-MBPD), respectively. After the addition of internal standards, the mixtures were washed with hexane, derivatized with phenylboronic acid, and analyzed by gas chromatography-mass spectrometer (GC-MS). The analytical method was evaluated in preliminary and feasibility studies performed by 13 laboratories. The preliminary study from 4 laboratories showed the reproducibility (RSD R ) of < 10% and recoveries in the range of 102-111% for the spiked 3-MCPD and 2-MCPD in extra virgin olive (EVO) oil, semi-solid palm oil, and solid palm oil. However, the RSDR and recoveries of Gly in the palm oil samples were not satisfactory. The Gly content of refrigerated palm oil samples decreased whereas the samples at room temperature were stable for three months, and this may be due to the depletion of Gly during cold storage. The feasibility studies performed by all 13 laboratories were conducted based on modifications of the shaking conditions for ester cleavage, the conditions of Gly bromination, and the removal of gel formed by residual lipase. Satisfactory RSDR were obtained for EVO oil samples spiked with standard esters (4.4% for 3-MCPD, 11.2% for 2-MCPD, and 6.6% for Gly).

Medicinal and cosmetics soap production from Jatropha oil.

PubMed

Shahinuzzaman, M; Yaakob, Zahira; Moniruzzaman, M

2016-06-01

Soap is the most useful things which we use our everyday life in various cleansing and cosmetics purposes. Jatropha oil is nonedible oil which has more benefits to soap making. It has also cosmetics and medicinal properties. But the presence of toxic Phorbol esters in Jatropha oil is the main constrains to use it. So it is necessary to search a more suitable method for detoxifying the Jatropha oil before the use as the main ingredient of soap production. This review implies a more suitable method for removing phorbol esters from Jatropha oil. Several parameters such as the % yield of pure Jatropha oil soap, TFM value of soap, total alkali content, free caustic alkalinity content, pH, the antimicrobial activity, and CMC value of general soap should be taken into consideration for soap from detoxified Jatropha oil. © 2016 Wiley Periodicals, Inc.

One step transesterification process of sludge palm oil (SPO) by using deep eutectic solvent (DES) in biodiesel production

NASA Astrophysics Data System (ADS)

Manurung, Renita; Ramadhani, Debbie Aditia; Maisarah, Siti

2017-06-01

Biodiesel production by using sludge palm oil (SPO) as raw material is generally synthesized in two step reactions, namely esterification and transesterification, because the free fatty acid (FFA) content of SPO is relatively high. However, the presence of choline chloride (ChCl), glycerol based deep eutectic solvent (DES), in transesterification may produce biodiesel from SPO in just one step. In this study, DES was produced by the mixture of ChCl and glycerol at molar ratio of 1:2 at a temperature of 80°C and stirring speed of 400 rpm for 1 hour. DES was characterized by its density and viscosity. The transesterification process was performed at reaction temperature of 70 °C, ethanol to oil molar with ratio of 9:1, sodium hydroxide as catalyst concentration of 1 % wt, DES as cosolvent with concentration of 0 to 5 % wt, stirring speed of 400 rpm, and one hour reaction time. The obtained biodiesel was then assessed with density, viscosity, and ester content as the parameters. FFA content of SPO as the raw material was 7.5290 %. In this case, DES as cosolvent in one step transesterification process of low feedstock could reduce the side reaction (saponification), decrease the time reaction, decrease the surface tension between ethanol and oil, and increase the mass transfer that simultaneously simplified the purification process and obtained the highest yield. The esters properties met the international standards of ASTM D 6751, with the highest yield obtained was 83.19% with 99.55% of ester content and the ratio of ethanol:oil of 9:1, concentration of DES of 4%, catalyst amount of 1%, temperature of reaction at 70°C and stirring speed of 400 rpm.

Two new fatty acids esters were detected in ginseng stems by the application of azoxystrobin and the increasing of antioxidant enzyme activity and ginsenosides content.

PubMed

Liang, Shuang; Xu, Xuan-Wei; Zhao, Xiao-Feng; Hou, Zhi-Guang; Wang, Xin-Hong; Lu, Zhong-Bin

2016-11-01

Panax ginseng C.A. Meyer is a valuable herb in China that has also gained popularity in the West because of its pharmacological properties. The constituents isolated and characterized in ginseng stems include ginsenosides, fatty acids, amino acids, volatile oils, and polysaccharides. In this study, the effects of fungicide azoxystrobin applied on antioxidant enzyme activity and ginsenosides content in ginseng stems was studied by using Panax ginseng C. A. Mey. cv. (the cultivar of Ermaya) under natural environmental conditions. The azoxystrobin formulation (25% SC) was sprayed three times on ginseng plants at different doses (150ga.i./ha and 225ga.i./ha), respectively. Two new fatty acids esters (ethyl linoleate and methyl linolenate) were firstly detected in ginseng stems by the application of azoxystrobin as foliar spray. The results indicated that activities of enzymatic antioxidants, the content of ginsenosides and two new fatty acids esters in ginseng stems in azoxystrobin-treated plants were increased. Azoxystrobin treatments to ginseng plants at all growth stages suggest that the azoxystrobin-induced delay of senescence is due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species (AOS). The activity of superoxide dismutase (SOD) in azoxystrobin-treated plants was about 1-3 times higher than that in untreated plants. And the effects was more significant (P=0.05) when azoxystrobin was applied at dose of 225ga.i./ha. This work suggests that azoxystrobin plays an important role in delaying of senescence by changing physiological and biochemical indicators and increasing ginsenosides content in ginseng stems. Copyright © 2016 Elsevier B.V. All rights reserved.

Expression of cholesteryl glucoside by heat shock in human fibroblasts

PubMed Central

Kunimoto, Shohko; Kobayashi, Tetsuyuki; Kobayashi, Susumu; Murakami-Murofushi, Kimiko

2000-01-01

ABSTRACT We investigated the heat-induced alteration of glycolipids in human cultured cells, TIG-3 fibroblasts, to show the expression of steryl glucoside by heat shock. A glycolipid band was detected on a thin-layer chromatography plate in lipid extracts from TIG-3 cells exposed to high temperature (42°C) for 15 and 30 minutes, while it was hardly detectable without heat shock. Both cholesterol and glucose were almost exclusively detected by gas liquid chromatography as degradation products of the lipid. The structure of the lipid molecule was elucidated by electrospray mass spectrometry to be a cholesteryl glucoside. This is the first report to show the occurrence of a steryl glucoside in mammalian cells, and this substance is considered to have a significant role in heat shock responses in mammalian cells. PMID:10701833

Fatty Acid Diversity is Not Associated with Neutral Genetic Diversity in Native Populations of the Biodiesel Plant Jatropha curcas L.

PubMed

Martínez-Díaz, Yesenia; González-Rodríguez, Antonio; Rico-Ponce, Héctor Rómulo; Rocha-Ramírez, Víctor; Ovando-Medina, Isidro; Espinosa-García, Francisco J

2017-01-01

Jatropha curcas L. (Euphorbiaceae) is a shrub native to Mexico and Central America, which produces seeds with a high oil content that can be converted to biodiesel. The genetic diversity of this plant has been widely studied, but it is not known whether the diversity of the seed oil chemical composition correlates with neutral genetic diversity. The total seed oil content, the diversity of profiles of fatty acids and phorbol esters were quantified, also, the genetic diversity obtained from simple sequence repeats was analyzed in native populations of J. curcas in Mexico. Using the fatty acids profiles, a discriminant analysis recognized three groups of individuals according to geographical origin. Bayesian assignment analysis revealed two genetic groups, while the genetic structure of the populations could not be explained by isolation-by-distance. Genetic and fatty acid profile data were not correlated based on Mantel test. Also, phorbol ester content and genetic diversity were not associated. Multiple linear regression analysis showed that total oil content was associated with altitude and seasonality of temperature. The content of unsaturated fatty acids was associated with altitude. Therefore, the cultivation planning of J. curcas should take into account chemical variation related to environmental factors. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Effects of clay minerals on diethyl phthalate degradation in Fenton reactions.

PubMed

Chen, Ning; Fang, Guodong; Zhou, Dongmei; Gao, Juan

2016-12-01

Phthalate esters are a group of plasticizers, which are commonly detected in China's soils and surface water. Fenton reactions are naturally occurring and widely applied in the degradation of contaminants. However, limited research was considered the effects of clay minerals on contaminants degradation with OH oxidation. In this study, batch experiments were conducted to investigate the degradation of diethyl phthalate (DEP) in Fenton reactions in the presence of clay minerals, and the effects of clay type, Fe content in clay structure. The results showed the clay adsorption inhibited total degradation of DEP, and Fe content in clay structure played an important role in DEP degradation, including in solution and adsorbed in clay minerals. Clay minerals with less Fe content (<3%) quenched OH radical, while nontronite with Fe content 19.2% improved OH radical generation and accelerated DEP degradation in solution. The degradation of clay-adsorbed DEP was much slower than DEP in solution. Six main products of DEP degradation were identified, including monoethyl phthalate, phthalate acid, hydroxyl diethyl phthalate, etc. This study implied that phthalate ester's degradation would be much slower in natural water than expected in the presence of clay minerals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmacological Targeting of the Atherogenic Dyslipidemia Complex: The Next Frontier in CVD Prevention Beyond Lowering LDL Cholesterol.

PubMed

Xiao, Changting; Dash, Satya; Morgantini, Cecilia; Hegele, Robert A; Lewis, Gary F

2016-07-01

Notwithstanding the effectiveness of lowering LDL cholesterol, residual CVD risk remains in high-risk populations, including patients with diabetes, likely contributed to by non-LDL lipid abnormalities. In this Perspectives in Diabetes article, we emphasize that changing demographics and lifestyles over the past few decades have resulted in an epidemic of the "atherogenic dyslipidemia complex," the main features of which include hypertriglyceridemia, low HDL cholesterol levels, qualitative changes in LDL particles, accumulation of remnant lipoproteins, and postprandial hyperlipidemia. We briefly review the underlying pathophysiology of this form of dyslipidemia, in particular its association with insulin resistance, obesity, and type 2 diabetes, and the marked atherogenicity of this condition. We explain the failure of existing classes of therapeutic agents such as fibrates, niacin, and cholesteryl ester transfer protein inhibitors that are known to modify components of the atherogenic dyslipidemia complex. Finally, we discuss targeted repurposing of existing therapies and review promising new therapeutic strategies to modify the atherogenic dyslipidemia complex. We postulate that targeting the central abnormality of the atherogenic dyslipidemia complex, the elevation of triglyceride-rich lipoprotein particles, represents a new frontier in CVD prevention and is likely to prove the most effective strategy in correcting most aspects of the atherogenic dyslipidemia complex, thereby preventing CVD events. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

New Era of Lipid-Lowering Drugs

PubMed Central

Rye, Kerry-Anne

2016-01-01

There are several established lipid-modifying agents, including statins, fibrates, niacin, and ezetimibe, that have been shown in randomized clinical outcome trials to reduce the risk of having an atherosclerotic cardiovascular event. However, in many people, the risk of having an event remains unacceptably high despite treatment with these established agents. This has stimulated the search for new therapies designed to reduce residual cardiovascular risk. New approaches that target atherogenic lipoproteins include: 1) inhibition of proprotein convertase subtilisin/kexin type 9 to increase removal of atherogenic lipoproteins from plasma; 2) inhibition of the synthesis of apolipoprotein (apo) B, the main protein component of atherogenic lipoproteins; 3) inhibition of microsomal triglyceride transfer protein to block the formation of atherogenic lipoproteins; 4) inhibition of adenosine triphosphate citrate lyase to inhibit the synthesis of cholesterol; 5) inhibition of the synthesis of lipoprotein(a), a factor known to cause atherosclerosis; 6) inhibition of apoC-III to reduce triglyceride-rich lipoproteins and to enhance high-density lipoprotein (HDL) functionality; and 7) inhibition of cholesteryl ester transfer protein, which not only reduces the concentration of atherogenic lipoproteins but also increases the level and function of the potentially antiatherogenic HDL fraction. Other new therapies that specifically target HDLs include infusions of reconstituted HDLs, HDL delipidation, and infusions of apoA-I mimetic peptides that mimic some of the functions of HDLs. This review describes the scientific basis and rationale for developing these new therapies and provides a brief summary of established therapies. PMID:26983688

Oxidation-labile subfraction of human plasma low density lipoprotein isolated by ion-exchange chromatography.

PubMed

Shimano, H; Yamada, N; Ishibashi, S; Mokuno, H; Mori, N; Gotoda, T; Harada, K; Akanuma, Y; Murase, T; Yazaki, Y

1991-05-01

We isolated subfractions of human plasma low density lipoprotein (LDL) using ion-exchange chromatography. Plasma LDL from normolipidemic subjects were applied to a DEAE Sepharose 6B column. After elution of the bulk of LDL at 150 mM NaCl (the major fraction), the residual LDL was eluted at 500 mM NaCl and designated as the minor fraction. The minor fraction, only less than 1% of total LDL, tended to be somewhat similar in certain properties to oxidized LDL, e.g., an increased negative charge, higher protein/cholesterol ratio, and a higher flotation density than native LDL. These results were consistent with data reported by Avogaro et al. (1988. Arteriosclerosis. 8: 79-87). However, assays of 125I-labeled LDL binding activity for LDL receptors equal to that of the major fraction. Incorporation of [14C]oleate into cholesteryl ester [acyl-CoA:cholesterol acyltransferase (ACAT) activity] in mouse peritoneal macrophages incubated with the minor fraction was only slightly greater than that with the major fraction. Incubation of the minor fraction with 0.5 microM Cu2+ caused a remarkable stimulation of ACAT activity, while stimulation by the major fraction required incubation with 5 microM Cu2+, suggesting that the minor fraction was relatively labile to oxidation. The minor but definite presence of a plasma LDL subfraction more negative and susceptible to oxidation implicates the possibility of its association with atherogenesis.

Mexican consensus on lysosomal acid lipase deficiency diagnosis.

PubMed

Vázquez-Frias, R; García-Ortiz, J E; Valencia-Mayoral, P F; Castro-Narro, G E; Medina-Bravo, P G; Santillán-Hernández, Y; Flores-Calderón, J; Mehta, R; Arellano-Valdés, C A; Carbajal-Rodríguez, L; Navarrete-Martínez, J I; Urbán-Reyes, M L; Valadez-Reyes, M T; Zárate-Mondragón, F; Consuelo-Sánchez, A

Lysosomal acid lipase deficiency (LAL-D) causes progressive cholesteryl ester and triglyceride accumulation in the lysosomes of hepatocytes and monocyte-macrophage system cells, resulting in a systemic disease with various manifestations that may go unnoticed. It is indispensable to recognize the deficiency, which can present in patients at any age, so that specific treatment can be given. The aim of the present review was to offer a guide for physicians in understanding the fundamental diagnostic aspects of LAL-D, to successfully aid in its identification. The review was designed by a group of Mexican experts and is presented as an orienting algorithm for the pediatrician, internist, gastroenterologist, endocrinologist, geneticist, pathologist, radiologist, and other specialists that could come across this disease in their patients. An up-to-date review of the literature in relation to the clinical manifestations of LAL-D and its diagnosis was performed. The statements were formulated based on said review and were then voted upon. The structured quantitative method employed for reaching consensus was the nominal group technique. A practical algorithm of the diagnostic process in LAL-D patients was proposed, based on clinical and laboratory data indicative of the disease and in accordance with the consensus established for each recommendation. The algorithm provides a sequence of clinical actions from different studies for optimizing the diagnostic process of patients suspected of having LAL-D. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis.

PubMed

Dong, Zhao; Shi, Haozhe; Zhao, Mingming; Zhang, Xin; Huang, Wei; Wang, Yuhui; Zheng, Lemin; Xian, Xunde; Liu, George

2018-06-01

Lecithin cholesterol acyltransferase (LCAT) plays a pivotal role in HDL metabolism but its influence on atherosclerosis remains controversial for decades both in animal and clinical studies. Because lack of cholesteryl ester transfer protein (CETP) is a major difference between murine and humans in lipoprotein metabolism, we aimed to create a novel Syrian Golden hamster model deficient in LCAT activity, which expresses endogenous CETP, to explore its metabolic features and particularly the influence of LCAT on the development of atherosclerosis. CRISPR/CAS9 gene editing system was employed to generate mutant LCAT hamsters. The characteristics of lipid metabolism and the development of atherosclerosis in the mutant hamsters were investigated using various conventional methods in comparison with wild type control animals. Hamsters lacking LCAT activity exhibited pro-atherogenic dyslipidemia as diminished high density lipoprotein (HDL) and ApoAI, hypertriglyceridemia, Chylomicron/VLDL accumulation and significantly increased ApoB100/48. Mechanistic study for hypertriglyceridemia revealed impaired LPL-mediated lipolysis and increased very low density lipoprotein (VLDL) secretion, with upregulation of hepatic genes involved in lipid synthesis and transport. The pro-atherogenic dyslipidemia in mutant hamsters was exacerbated after high fat diet feeding, ultimately leading to near a 3- and 5-fold increase in atherosclerotic lesions by aortic en face and sinus lesion quantitation, respectively. Our findings demonstrate that LCAT deficiency in hamsters develops pro-atherogenic dyslipidemia and promotes atherosclerotic lesion formation. Published by Elsevier Inc.

Increase of antioxidative potential of rat plasma by oral administration of proanthocyanidin-rich extract from grape seeds.

PubMed

Koga, T; Moro, K; Nakamori, K; Yamakoshi, J; Hosoyama, H; Kataoka, S; Ariga, T

1999-05-01

The effect of a single oral administration of proanthocyanidins, oligomeric and polymeric polyhydroxyflavan-3-ol units, on the antioxidative potential of blood plasma was studied in rats. Proanthocyanidin-rich extract from grape seeds was administered by intragastric intubation to fasted rats at 250 mg/kg of body weight. The plasma obtained from water- or proanthocyanidin-administered rats was oxidized by incubation with copper sulfate or 2, 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) at 37 degrees C, and the formation of cholesteryl ester hydroperoxides (CE-OOH) was followed. The plasma obtained from proanthocyanidin-administered rats was significantly more resistant against both copper ion-induced and AAPH-induced formation of CE-OOH than that from control rats. The lag phase in the copper ion-induced oxidation of rat plasma was remarkably increased at 15 min after administration of proanthocyanidins and reached a maximum level at 30 min. When the plasma from proanthocyanidin-administered rat was hydrolyzed by sulfatase and beta-glucuronidase following analysis by high-performance liquid chromatography with electrochemical detection, metabolites of proanthocyanidins occurred in rat plasma at 15 min after administration, three peaks of which were identified as gallic acid, (+)-catechin, and (-)-epicatechin. These results suggest that the intake of proanthocyanidins, the major polyphenols in red wine, increases the resistance of blood plasma against oxidative stress and may contribute to physiological functions of plant food including wine through their in vivo antioxidative ability.

Control of ACAT2 liver expression by HNF4{alpha}: lesson from MODY1 patients.

PubMed

Pramfalk, C; Karlsson, E; Groop, L; Rudel, L L; Angelin, B; Eriksson, M; Parini, P

2009-08-01

ACAT2 is thought to be responsible for cholesteryl ester production in chylomicron and VLDL assembly. Recently, we identified HNF1alpha as an important regulator of the human ACAT2 promoter. Thus, we hypothesized that MODY3 (HNF1alpha gene mutations) and possibly MODY1 (HNF4alpha, upstream regulator of HNF1alpha, gene mutations) subjects may have lower VLDL esterified cholesterol. Serum analysis and lipoprotein separation using size-exclusion chromatography were performed in controls and MODY1 and MODY3 subjects. In vitro analyses included mutagenesis and cotransfections in HuH7 cells. Finally, the relevance in vivo of these findings was tested by ChIP assays in human liver. Whereas patients with MODY3 had normal lipoprotein composition, those with MODY1 had lower levels of VLDL and LDL esterified cholesterol, as well as of VLDL triglyceride. Mutagenesis revealed one important HNF4 binding site in the human ACAT2 promoter. ChIP assays and protein-to-protein interaction studies showed that HNF4alpha, directly or indirectly (via HNF1alpha), can bind to the ACAT2 promoter. We identified HNF4alpha as an important regulator of the hepatocyte-specific expression of the human ACAT2 promoter. Our results suggest that the lower levels of esterified cholesterol in VLDL- and LDL-particles in patients with MODY1 may-at least in part-be attributable to lower ACAT2 activity in these patients.

PCSK9 inhibition fails to alter hepatic LDLR, circulating cholesterol, and atherosclerosis in the absence of ApoE.

PubMed

Ason, Brandon; van der Hoorn, José W A; Chan, Joyce; Lee, Edward; Pieterman, Elsbet J; Nguyen, Kathy Khanh; Di, Mei; Shetterly, Susan; Tang, Jie; Yeh, Wen-Chen; Schwarz, Margrit; Jukema, J Wouter; Scott, Rob; Wasserman, Scott M; Princen, Hans M G; Jackson, Simon

2014-11-01

LDL cholesterol (LDL-C) contributes to coronary heart disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) increases LDL-C by inhibiting LDL-C clearance. The therapeutic potential for PCSK9 inhibitors is highlighted by the fact that PCSK9 loss-of-function carriers exhibit 15-30% lower circulating LDL-C and a disproportionately lower risk (47-88%) of experiencing a cardiovascular event. Here, we utilized pcsk9(-/-) mice and an anti-PCSK9 antibody to study the role of the LDL receptor (LDLR) and ApoE in PCSK9-mediated regulation of plasma cholesterol and atherosclerotic lesion development. We found that circulating cholesterol and atherosclerotic lesions were minimally modified in pcsk9(-/-) mice on either an LDLR- or ApoE-deficient background. Acute administration of an anti-PCSK9 antibody did not reduce circulating cholesterol in an ApoE-deficient background, but did reduce circulating cholesterol (-45%) and TGs (-36%) in APOE*3Leiden.cholesteryl ester transfer protein (CETP) mice, which contain mouse ApoE, human mutant APOE3*Leiden, and a functional LDLR. Chronic anti-PCSK9 antibody treatment in APOE*3Leiden.CETP mice resulted in a significant reduction in atherosclerotic lesion area (-91%) and reduced lesion complexity. Taken together, these results indicate that both LDLR and ApoE are required for PCSK9 inhibitor-mediated reductions in atherosclerosis, as both are needed to increase hepatic LDLR expression. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

Association Studies of Specific Cholesterol Related Genes (APOE, LPL, and CETP) with Lipid Profile and Memory Function: A Correlative Study Among Rural and Tribal Population of Dharmapuri District, India.

PubMed

Periyasamy, Sabapathy; Sathya, Mohan; Karthick, Chennakesavan; Kandasamy, Mahesh; Shanmugaapriya, Sellathamby; Tamilselvan, Jeyavelu; Jayachandran, Kesavan Swaminathan; Anusuyadevi, Muthuswamy

2017-01-01

 Epidemiological studies state that dementia has multiple etiologies including genetic mutation, genetic variation, and environmental factors. Accumulating evidence suggests that dysregulation of cholesterol homeostasis is the major etiological factor in initiating neurodegeneration. Apolipoprotein E (APOE) polymorphic alleles and associated polymorphism of lipoprotein lipase (LPL) and cholesteryl ester transfer protein (CETP) that are important components in regulating cholesterol metabolism are implicated in neurodegenerative diseases. Therefore, the current study focused on identifying the association between several common polymorphism (viz., APOE, CETP, and LPL) to that of change in serum lipid levels and memory symptoms. Volunteer subjects aged 50 and above from rural and tribal areas of the Dharmapuri district, Tamilnadu, India were chosen for the current study and polymorphism was analyzed using PCR-RFLP. Fasting lipid profile and memory function using simplified version of Global Clinical Dementia rating were assessed. Significant difference in the major lipid profile parameters were observed (TC, TGL, LDL, VLDL) among rural and tribal populations that were associated with significant genotypic variation of APOE, CETP, and LPL. Regression analysis revealed significant risk for memory loss that are dependent on age and genetic variants like CETP. These data predict positive correlation between cholesterol-associated genes and their relationship to altered lipid profile and memory symptoms, which possibly link gene-polymorphism and susceptibility ratio for aging and dementia.

Association of postalimentary lipemia with atherosclerotic manifestations.

PubMed

Tentor, J; Nakamura, R T; Gidlund, M; Barros-Mazon, S; Harada, L M; Zago, V S; Oba, J F; Faria, E C de

2012-11-01

We identified different lipemic and metabolic responses after the ingestion of a standardized meal by healthy adults and related them to atherosclerotic markers. Samples from 60 normolipidemic adults were collected before and after a liquid meal (40 g fat/m² body surface) at 0, 2, 4, 6, and 8 h for measurements of lipids, free fatty acids (FFA), insulin, cholesteryl ester transfer protein (CETP), autoantibodies to epitopes of oxidized LDL (oxLDL Ab), lipolytic activities, and apolipoprotein E polymorphism. Mean carotid intima-media thickness (cIMT) was determined by Doppler ultrasound. The volunteers were classified into early (N = 39) and late (N = 31) triacylglycerol (TAG) responders to the test meal. Late responders showed lower HDL cholesterol concentration at fasting and in the TAG peak, lower insulin and higher FFA concentrations compared to early responders. Multivariate regression analyses showed that mean cIMT was associated with gender (male) and age in early responders and by cholesterol levels at the 6th hour in late responders. oxLDL Ab were explained by lipoprotein lipase and negatively by hepatic lipase and oxLDL Ab (fasting period) by CETP (negative) and FFA (positive). This study is the first to identify a postalimentary insulin resistance state, combined with a reduced CETP response exclusively among late responders, and the identification of the regulators of postalimentary atherogenicity. Further research is required to determine the metabolic mechanisms described in the different postalimentary phenotypes observed in this study, as well as in different pathological states, as currently investigated in our laboratory.

Diet-induced alterations of host cholesterol metabolism are likely to affect the gut microbiota composition in hamsters.

PubMed

Martínez, Inés; Perdicaro, Diahann J; Brown, Andrew W; Hammons, Susan; Carden, Trevor J; Carr, Timothy P; Eskridge, Kent M; Walter, Jens

2013-01-01

The gastrointestinal microbiota affects the metabolism of the mammalian host and has consequences for health. However, the complexity of gut microbial communities and host metabolic pathways make functional connections difficult to unravel, especially in terms of causation. In this study, we have characterized the fecal microbiota of hamsters whose cholesterol metabolism was extensively modulated by the dietary addition of plant sterol esters (PSE). PSE intake induced dramatic shifts in the fecal microbiota, reducing several bacterial taxa within the families Coriobacteriaceae and Erysipelotrichaceae. The abundance of these taxa displayed remarkably high correlations with host cholesterol metabolites. Most importantly, the associations between several bacterial taxa with fecal and biliary cholesterol excretion showed an almost perfect fit to a sigmoidal nonlinear model of bacterial inhibition, suggesting that host cholesterol excretion can shape microbiota structure through the antibacterial action of cholesterol. In vitro experiments suggested a modest antibacterial effect of cholesterol, and especially of cholesteryl-linoleate, but not plant sterols when included in model bile micelles. The findings obtained in this study are relevant to our understanding of gut microbiota-host lipid metabolism interactions, as they provide the first evidence for a role of cholesterol excreted with the bile as a relevant host factor that modulates the gut microbiota. The findings further suggest that the connections between Coriobacteriaceae and Erysipelotrichaceae and host lipid metabolism, which have been observed in several studies, could be caused by a metabolic phenotype of the host (cholesterol excretion) affecting the gut microbiota.

Differential effects of gemfibrozil and fenofibrate on reverse cholesterol transport from macrophages to feces in vivo.

PubMed

Rotllan, Noemí; Llaverías, Gemma; Julve, Josep; Jauhiainen, Matti; Calpe-Berdiel, Laura; Hernández, Cristina; Simó, Rafael; Blanco-Vaca, Francisco; Escolà-Gil, Joan Carles

2011-02-01

Gemfibrozil and fenofibrate, two of the fibrates most used in clinical practice, raise HDL cholesterol (HDLc) and are thought to reduce the risk of atherosclerotic cardiovascular disease. These drugs act as PPARα agonists and upregulate the expression of genes crucial in reverse cholesterol transport (RCT). In the present study, we determined the effects of these two fibrates on RCT from macrophages to feces in vivo in human apoA-I transgenic (hApoA-ITg) mice. [(3)H]cholesterol-labeled mouse macrophages were injected intraperitoneally into hApoA-ITg mice treated with intragastric doses of fenofibrate, gemfibrozil or a vehicle solution for 17days, and radioactivity was determined in plasma, liver and feces. Fenofibrate, but not gemfibrozil, enhanced [(3)H]cholesterol flux to plasma and feces of female hApoA-ITg mice. Fenofibrate significantly increased plasma HDLc, HDL phospholipids, hApoA-I levels and phospholipid transfer protein activity, whereas these parameters were not altered by gemfibrozil treatment. Unlike gemfibrozil, fenofibrate also induced the generation of larger HDL particles, which were more enriched in cholesteryl esters, together with higher potential to generate preβ-HDL formation and caused a significant increase in [(3)H]cholesterol efflux to plasma. Our findings demonstrate that fenofibrate promotes RCT from macrophages to feces in vivo and, thus, highlight a differential action of this fibrate on HDL. Copyright © 2010 Elsevier B.V. All rights reserved.

Intestinal-fatty acid binding protein and lipid transport in human intestinal epithelial cells

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

Montoudis, Alain; Delvin, Edgard; Canadian Institute of Health Research, Group of the Functional Development and Physiopathology of the Digestive Tract, and Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, Que., Canada J1H 5N4

2006-01-06

Intestinal-fatty acid binding protein (I-FABP) is a 14-15 kDa cytoplasmic molecule highly expressed in the enterocyte. Although different functions have been proposed for various FABP family members, the specific function of I-FABP in human intestine remains unclear. Here, we studied the role of I-FABP in molecularly modified normal human intestinal epithelial cells (HIEC-6). cDNA transfection resulted in 90-fold I-FABP overexpression compared to cells treated with empty pQCXIP vector. The high-resolution immunogold technique revealed labeling mainly in the cytosol and confirmed the marked phenotype abundance of I-FABP in cDNA transfected cells. I-FABP overexpression was not associated with alterations in cell proliferationmore » and viability. Studies using these transfected cells cultured with [{sup 14}C]oleic acid did not reveal higher efficiency in de novo synthesis or secretion of triglycerides, phospholipids, and cholesteryl esters compared to cells treated with empty pQCXIP vector only. Similarly, the incubation with [{sup 35}S]methionine did not disclose a superiority in the biogenesis of apolipoproteins (apo) A-I, A-IV, B-48, and B-100. Finally, cells transfected with I-FABP did not exhibit an increased production of chylomicrons, VLDL, LDL, and HDL. Our observations establish that I-FABP overexpression in normal HIEC-6 is not related to cell proliferation, lipid esterification, apo synthesis, and lipoprotein assembly, and, therefore, exclude its role in intestinal fat transport.« less

Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas.

PubMed

Jadid, Nurul; Mardika, Rizal Kharisma; Purwani, Kristanti Indah; Permatasari, Erlyta Vivi; Prasetyowati, Indah; Irawan, Mohammad Isa

2018-06-01

Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas . Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin ( ACT ) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha .

Analysis of aroma compounds of pitaya fruit wine

NASA Astrophysics Data System (ADS)

Gong, Xiao; Ma, Lina; Li, Liuji; Yuan, Yuan; Peng, Shaodan; Lin, Mao

2017-12-01

In order to analyze the volatile components in red pitaya fruit wine, the study using headspace solid phase microextractionand gas chromatography-mass spectrometry technology of pitaya fruit juice and wine aroma composition analysis comparison. Results showed that 55 volatile components were detected in red pitaya fruit wine, including 12 kinds of alcohol (18.16%), 18 kinds of esters (66.17%), 7 kinds of acids (5.94%), 11 kinds of alkanes (4.32%), one kind of aldehyde (0.09%), 2 kinds of olefins (0.09%) and 3 kinds of other volatile substances (0.23%). Relative contents among them bigger have 11 species, such as decanoic acid, ethyl ester (22.92%), respectively, diisoamylene (20.75%), octanoic acid, ethyl ester (17.73%), etc. The red pitaya fruit wine contained a lot of aroma components, which offer the products special aroma like brandy, rose and fruit.

[Research on source profile of aerosol organic compounds in leather plant].

PubMed

Wang, Bo-Guang; Zhou, Yan; Feng, Zhi-Cheng; Liu, Hui-Xuan

2009-04-15

Through investigating current air pollution condition for PM10 in every factories of different style leather plants in Pearl River Delta, characteristic profile of semi-volatile organic compounds in PM10 emitted from leather factories and their contents were researched by using ultrasonic and gas chromatography and mass spectrum technology. The 6 types of organic compounds containing 46 species in total were found in the collected samples, including phenyl compounds, alcohols, PAHs, acids, esters and amides. The concentrations of PM10 in leather tanning plant, leather dying plant and man-made leather plant were 678.5, 454.5, 498.6 microgm x m(-3) respectively, and concentration of organic compounds in PM10 were 10.04, 6.89, 14.21 microg x m(-3) in sequence. The more important type of pollutants in each leather plants had higher contribution to total organic mass as follows, esters and amides in tanning plants profile account for 43.47% and 36.51% respectively; esters and alcohols in dying plants profiles account for 52.52% and 16.16% respectively; esters and amide in man-made leather plant have the highest content and account for 57.07% and 24.17% respectively. In the aerosol organic source profiles of tested leather plants, 9-octadecenamide was the abundant important species with the weight of 26.15% in tanning plant, and Bis(2-ethylhexyl) phthalate was up to 44.19% in the dying plant, and Bis(2-ethylhexyl) maleate and 1-hydroxy-piperidine had obviously higher weight in man-made plant than the other two plants.

Combined effects of nutrients and temperature on the production of fermentative aromas by Saccharomyces cerevisiae during wine fermentation.

PubMed

Rollero, Stéphanie; Bloem, Audrey; Camarasa, Carole; Sanchez, Isabelle; Ortiz-Julien, Anne; Sablayrolles, Jean-Marie; Dequin, Sylvie; Mouret, Jean-Roch

2015-03-01

Volatile compounds produced by yeast during fermentation greatly influence the organoleptic qualities of wine. We developed a model to predict the combined effects of initial nitrogen and phytosterol content and fermentation temperature on the production of volatile compounds. We used a Box-Behnken design and response surface modeling to study the response of Lalvin EC1118® to these environmental conditions. Initial nitrogen content had the greatest influence on most compounds; however, there were differences in the value of fermentation parameters required for the maximal production of the various compounds. Fermentation parameters affected differently the production of isobutanol and isoamyl alcohol, although their synthesis involve the same enzymes and intermediate. We found differences in regulation of the synthesis of acetates of higher alcohols and ethyl esters, suggesting that fatty acid availability is the main factor influencing the synthesis of ethyl esters whereas the production of acetates depends on the activity of alcohol acetyltransferases. We also evaluated the effect of temperature on the total production of three esters by determining gas-liquid balances. Evaporation largely accounted for the effect of temperature on the accumulation of esters in liquid. Nonetheless, the metabolism of isoamyl acetate and ethyl octanoate was significantly affected by this parameter. We extended this study to other strains. Environmental parameters had a similar effect on aroma production in most strains. Nevertheless, the regulation of the synthesis of fermentative aromas was atypical in two strains: Lalvin K1M® and Affinity™ ECA5, which produces a high amount of aromatic compounds and was obtained by experimental evolution.

Determination of nitrate esters in water samples Comparison of efficiency of solid-phase extraction and solid-phase microextraction.

PubMed

Jezová, Vera; Skládal, Jan; Eisner, Ales; Bajerová, Petra; Ventura, Karel

2007-12-07

This paper deals with comparison of efficiency of extraction techniques (solid-phase extraction, SPE and solid-phase microextraction, SPME) used for extraction of nitrate esters (ethyleneglycoldinitrate, EGDN and nitroglycerin, NG), representing the first step of the method of quantitative determination of trace concentrations of nitrate esters in water samples. EGDN and NG are subsequently determined by means of high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Optimization of SPE and SPME conditions was carried out using model water samples. Seven SPE cartridges were tested and the conditions were optimized (type of sorbent, type and volume of solvent to be used as eluent). For both nitrate esters the limit of detection (LOD) and the limit of quantification (LOQ) obtained using SPE/HPLC-UV were 0.23 microg mL(-1) and 0.70 microg mL(-1), respectively. Optimization of SPME conditions: type of SPME fibre (four fibres were tested), type and time of sorption/desorption, temperature of sorption. PDMS/DVB (polydimethylsiloxane/divinylbenzene) fibre coating proved to be suitable for extraction of EGDN and NG. For this fibre the LOD and the LOQ for both nitrate esters were 0.16 microg mL(-1) and 0.50 microg mL(-1), respectively. Optimized methods SPE/HPLC-UV and SPME/HPLC-UV were then used for quantitative determination of nitrate esters content in real water samples from the production of EGDN and NG.

Synthesis and evaluation of L-cystathionine as a standard for amino acid analysis.

PubMed

Amino, Yusuke; Suzuki, Yumiko

2017-01-01

L-Cystathionine is a key nonprotein amino acid related to metabolic conditions. The quantitative determination of L-cystathionine in physiological fluids by amino acid analysis is important for clinical diagnosis; however, certified reference material for L-cystathionine with satisfactory purity, content, and quantity has been unavailable until recently. Consequently, a practical and simple method for the preparation of L-cystathionine was examined, which involves thioalkylation of N-tert-butoxycarbonyl-L-cysteine tert-butyl ester, derived from L-cystine, with (2S)-2-(tert-butoxycarbonyl)amino-4-iodobutanoic acid tert-butyl ester, derived from L-aspartic acid, to obtain L-cystathionine with protecting groups, followed by single-step deprotection under mild conditions. This method produces L-cystathionine in high purity (99.4%) and having sufficient percentage content according to amino acid analysis, which could be used as a standard for the amino acid analysis of physiological fluids.

The influence of yeast on chemical composition and sensory properties of dry white wines.

PubMed

Puertas, B; Jimenez-Hierro, M J; Cantos-Villar, E; Marrufo-Curtido, A; Carbú, M; Cuevas, F J; Moreno-Rojas, J M; González-Rodríguez, V E; Cantoral, J M; Ruiz-Moreno, M J

2018-07-01

This study evaluates the impact on two varietal white wines from 'Chardonnay' and 'Verdejo' cultivars of different fermentative strategies: inoculation with Saccharomyces cerevisiae yeast (CT), sequential inoculation (Torulaspora delbrueckii/Saccharomyces cerevisiae) (SI), and spontaneous fermentation (SP). The wines' chemical composition was characterized by oenological parameters, organic acids, metals, major volatile compounds, ester compounds and sensory analyses. The fermentative strategy (CT, SI and SP) was found to be a key factor for assessing different styles of white wines. SI wines showed enhanced 'mature fruit' nuances and a chemical profile characterized by higher content of ethyl propanoate, ethyl isobutyrate and ethyl dihydrocinnamate. Meanwhile, the SP wines presented enhanced "stone fruit" nuances possible related to the higher contents of 2-phenyl acetate and isobutyl acetate. After a chemometric approach the above esters were identified as the markers of each fermentative strategy, independently of the variety. Copyright © 2018 Elsevier Ltd. All rights reserved.

Catalytic pyrolysis of model compounds and waste cooking oil for production of light olefins over La/ZSM-5 catalysts

NASA Astrophysics Data System (ADS)

Li, F. W.; Ding, S. L.; Li, L.; Gao, C.; Zhong, Z.; Wang, S. X.; Li, Z. X.

2016-08-01

Waste cooking oil (WCO) and its model compounds (oleic acid and methyl laurate) are catalytically pyrolyzed in a fixed-bed reactor over La modified ZSM-5 catalysts (La/ZSM-5) aiming for production of C2-C4 light olefins. The LaO content in catalysts was set at 0, 2, 6, 10 and 14 wt%. The gas and liquid products are analyzed. The La/ZSM-5 catalyst with 6% LaO showed higher selectivity to light olefins when WCO and methyl laurate were pyrolyzed, and olefin content was 26% for WCO and 21% for methyl laurate. The catalyst with 10% LaO showed high selectivity to light olefins (28.5%) when oleic acid was pyrolyzed. The liquid products from WCO and model compounds mainly contain esters and aromatic hydrocarbons. More esters were observed in liquid products from methyl laurate and WCO pyrolysis, indicating that it is more difficult to pyrolyze esters and WCO than oleic acid. The coked catalysts were analyzed by temperature-programmed oxidation. The result shows that graphite is the main component of coke. The conversion of WCO to light olefins potentially provides an alternative and sustainable route for production of the key petrochemicals.

Synthesis of poly(ester-carbonate) with a pendant acetylcholine analog for promoting neurite growth.

PubMed

Xing, Dongming; Ma, Lie; Gao, Changyou

2014-10-01

The modification of biodegradable polyesters with bioactive molecules has become an important strategy for controlling neuron adhesion and neurite outgrowth in nerve regeneration. In this study we report a biodegradable poly(ester-carbonate) with a pendant acetylcholine analog, which a neurotransmitter for the enhancement of neuron adhesion and outgrowth. The acetylcholine-functionalized poly(ester-carbonate) (Ach-P(LA-ClTMC)) was prepared by copolymerizing l-lactide (LA) and 5-methyl-5-chloroethoxycarbonyl trimethylene carbonate (ClTMC), followed by quaternization with trimethylamine. The acetylcholine analog content could be modulated by changing the molar feeding fraction of ClTMC. The incorporation of the acetylcholine analog improved the hydrophilicity of the films, but the acetylcholine analog content did not significantly influence the surface morphology of the acetylcholine-functionalized films. The results of PC12 cell culture showed that the acetylcholine analog promoted cell viability and neurite outgrowth in a concentration-dependent manner. The longest length of neurite and the percentage of cells bearing neurites were obtained on the Ach-P(LA-ClTMC)-10 film. All the results indicate that the integration of the acetylcholine analog at an appropriate fraction could be an effective strategy for optimizing the existing biodegradable polyesters for nerve regeneration applications. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effect of torrefaction pretreatment on the pyrolysis of rubber wood sawdust analyzed by Py-GC/MS.

PubMed

Chen, Wei-Hsin; Wang, Chao-Wen; Kumar, Gopalakrishnan; Rousset, Patrick; Hsieh, Tzu-Hsien

2018-07-01

The aim of this study was to investigate the effect of torrefaction on the pyrolysis of rubber wood sawdust (RWS) using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Three typical torrefaction temperatures (200, 250, and 300 °C) and pyrolysis temperatures (450, 500, and 550 °C) were considered. The results suggested that only diethyl phthalate, belonging to esters, was detected at the torrefaction temperatures of 200 and 250 °C, revealing hemicellulose degradation. With the torrefaction temperature of 300 °C, esters, aldehydes, and phenols were detected, suggesting the predominant decomposition of hemicellulose and lignin. The double-shot pyrolysis indicated that the contents of oxy-compounds such as acids and aldehydes in pyrolysis bio-oil decreased with rising torrefaction temperature, implying that increasing torrefaction severity abated oxygen content in the bio-oil. With the torrefaction temperature of 300 °C, relatively more cellulose was retained in the biomass because the carbohydrate content in the pyrolysis bio-oil increased significantly. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hydrogen-bonding A(LS)2-type low-molecular-mass gelator and its thermotropic mesomorphic behavior.

PubMed

Hou, Qiufei; Wang, Shichao; Zang, Libin; Wang, Xiaoliang; Jiang, Shimei

2009-10-15

A unique cholesterol-based A(LS)2-type gelator, which is a hydrogen-bonding complex based on an ALS-type non-gelator molecule 3-cholesteryl 4-(trans-2-(4-pyridinyl)vinyl)phenyl succinate and a counterpart 3-cholesteryloxycarbonylpropanoic acid, shows strong gelation ability in alcohol and aromatic solvents. The formed gel has a high Tg at low gelation concentration, and its xerogel shows fibrillar microstructure revealed by scanning electron microscopy (SEM). FTIR confirms the existence of intermolecular hydrogen bond in the gelator, and X-ray diffraction (XRD) analysis reveals that the gelator possesses a folded conformation in gel and self-assembles into the fibrillar structure mainly by van der Waals interaction between cholesteryl moieties of the gelator. Further more, the thermotropic behavior of the xerogel is studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM), which shows typical optical textures of liquid crystals.

Cell-penetrating cationic siRNA and lipophilic derivatives efficient at nanomolar concentrations in the presence of serum and albumin.

PubMed

Perche, Phanélie; Nothisen, Marc; Bagilet, Jérémy; Behr, Jean-Paul; Kotera, Mitsuharu; Remy, Jean-Serge

2013-08-28

Despite its considerable interest in human therapy, in vivo siRNA delivery is still suffering from hurdles of vectorization. We have shown recently efficient gene silencing by non-vectorized cationic siRNA. Here, we describe the synthesis and in vitro evaluation of new amphiphilic cationic siRNA. C₁₂-, (C₁₂)₂- and cholesteryl-spermine(x)-siRNA were capable of luciferase knockdown at nanomolar concentrations without vectorization (i.e. one to two orders of magnitude more potent than commercially available cholesteryl siRNA). Moreover, incubation in the presence of serum did not impair their efficiency. Finally, amphiphilic cationic siRNA was pre-loaded on albumin. In A549Luc cells in the presence of serum, these siRNA conjugates were highly effective and had low toxicity. Copyright © 2013. Published by Elsevier B.V.

Sinapic acid or its derivatives interfere with abscisic acid homeostasis during Arabidopsis thaliana seed germination.

PubMed

Bi, Baodi; Tang, Jingliang; Han, Shuang; Guo, Jinggong; Miao, Yuchen

2017-06-06

Sinapic acid and its esters have broad functions in different stages of seed germination and plant development and are thought to play a role in protecting against ultraviolet irradiation. To better understand the interactions between sinapic acid esters and seed germination processes in response to various stresses, we analyzed the role of the plant hormone abscisic acid (ABA) in the regulation of sinapic acid esters involved in seed germination and early seedling growth. We found that exogenous sinapic acid promotes seed germination in a dose-dependent manner in Arabidopsis thaliana. High-performance liquid chromatography mass spectrometry analysis showed that exogenous sinapic acid increased the sinapoylcholine content of imbibed seeds. Furthermore, sinapic acid affected ABA catabolism, resulting in reduced ABA levels and increased levels of the ABA-glucose ester. Using mutants deficient in the synthesis of sinapate esters, we showed that the germination of mutant sinapoylglucose accumulator 2 (sng2) and bright trichomes 1 (brt1) seeds was more sensitive to ABA than the wild-type. Moreover, Arabidopsis mutants deficient in either abscisic acid deficient 2 (ABA2) or abscisic acid insensitive 3 (ABI3) displayed increased expression of the sinapoylglucose:choline sinapoyltransferase (SCT) and sinapoylcholine esterase (SCE) genes with sinapic acid treatment. This treatment also affected the accumulation of sinapoylcholine and free choline during seed germination. We demonstrated that sinapoylcholine, which constitutes the major phenolic component in seeds among various minor sinapate esters, affected ABA homeostasis during seed germination and early seedling growth in Arabidopsis. Our findings provide insights into the role of sinapic acid and its esters in regulating ABA-mediated inhibition of Arabidopsis seed germination in response to drought stress.

History and development of plant sterol and stanol esters for cholesterol-lowering purposes.

PubMed

Thompson, Gilbert R; Grundy, Scott M

2005-07-04

Plant stanol esters provide a novel approach to lowering plasma low-density lipoprotein (LDL) cholesterol by dietary means. Their development was preceded by a long period of research into the cholesterol-lowering properties of plant sterols and, recently, plant stanols. Both classes of compound competitively inhibit the absorption of cholesterol and thus lower its level in plasma. Initial impressions were that stanols were more effective and safer than sterols, but the negative outcome of a study led to the recognition that the lipid solubility of free stanols was very limited. This was overcome by esterifying them with fatty acids, with the resultant stanol esters being freely soluble in fat spreads. This led to the launch of Benecol (margarine; Raisio Group, Raisio, Finland) in 1995. The coincident publication of the year-long North Karelia study conclusively demonstrated the long-term LDL-lowering efficacy of plant stanol esters. Variables that might influence the efficacy of stanol esters include dose, frequency of administration, food vehicle in which the stanol ester is incorporated, and background diet. The effective dose is 1 to 3 g/day, expressed as free stanol, which, in placebo-controlled studies, decreased LDL cholesterol by 6% to 15%. This effect is maintained, appears to be similar with once-daily or divided dosage, and is independent of the fat content of the food vehicle. Short-term studies suggest that equivalent amounts of plant sterol and stanol esters are similarly effective in lowering LDL, the main difference being that plasma plant sterol levels increase on plant sterols and decrease on plant stanols. The clinical significance of these changes remains to be determined.

Indomethacin-5-fluorouracil-methyl ester dry emulsion: a potential oral delivery system for 5-fluorouracil.

PubMed

Wang, Jing; Hu, Yanchen; Li, Ling; Jiang, Tongying; Wang, Siling; Mo, Fengkui

2010-06-01

To produce a combined effect of indomethacin (IDM) and 5-fluorouracil (5FU) for cancer therapy, the side effects of IDM on the gastrointestinal (GI) tract were reduced and the oral adsorption of 5FU was improved. Indomethacin-5-fluorouracil-methyl ester (IFM) dry emulsion was prepared and evaluated as a potential oral delivery system for 5FU. IFM was synthesized by formation of an ester between IDM and 5FU intermediate and then characterized by structure, melting point, solubility, apparent partition coefficient, and incubation with GI tract contents and plasma. Gum acacia and sodium carboxymethyl cellulose (CMC-Na) were applied as the adsorbent and solid carrier to prepare IFM dry emulsion. IFM dry emulsion was then characterized by reconstitution in water and in situ intestinal perfusion experiment. Physicochemical properties of the new synthesized compound confirmed the formation of IFM. Incubation of IFM in the contents of the GI tract and plasma revealed that IFM was not relatively stable in GI contents during the time period of transit through the GI tract, whereas it was very unstable in plasma and released 5FU rapidly. The IFM dry emulsion could be easily reconstituted in water, and the mean particle size was 2.416 microm. The absorption rate constant (K) for IFM with concentration of 2, 5, and 10 microg/mL in the in situ perfusion experiment were 0.473, 0.423, and 0.433/h, respectively, demonstrating passive diffusion of IFM across the biological membranes. This study indicates that the IFM dry emulsion may represent a potentially useful oral delivery system for 5FU.

Gallic Acid Content in Taiwanese Teas at Different Degrees of Fermentation and Its Antioxidant Activity by Inhibiting PKCδ Activation: In Vitro and in Silico Studies.

PubMed

Kongpichitchoke, Teeradate; Chiu, Ming-Tzu; Huang, Tzou-Chi; Hsu, Jue-Liang

2016-10-12

Teas can be classified according to their degree of fermentation, which has been reported to affect both the bioactive components in the teas and their antioxidative activity. In this study, four kinds of commercial Taiwanese tea at different degrees of fermentation, which include green (non-fermented), oolong (semi-fermented), black (fully fermented), and Pu-erh (post-fermented) tea, were profiled for catechin levels by using high performance liquid chromatography (HPLC). The result indicated that the gallic acid content in tea was directly proportional to the degree of fermentation in which the lowest and highest gallic acid content were 1.67 and 21.98 mg/g from green and Pu-erh tea, respectively. The antioxidative mechanism of the gallic acid was further determined by in vitro and in silico analyses. In vitro assays included the use of phorbol ester-induced macrophage RAW264.7 cell model for determining the inhibition of reactive oxygen species (ROS) production, and PKCδ and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit (p47) activations. The results showed that only at a concentration of 5.00 μM could gallic acid significantly ( p < 0.05) reduce ROS levels in phorbol ester-activated macrophages. Moreover, protein immunoblotting expressed similar results in which activations of PKCδ and p47 were only significantly ( p < 0.05) attenuated by 5.00 μM treatment. Lastly, in silico experiments further revealed that gallic acid could block PKCδ activation by occupying the phorbol ester binding sites of the protein.

Entamoeba mitosomes play an important role in encystation by association with cholesteryl sulfate synthesis

PubMed Central

Mi-ichi, Fumika; Miyamoto, Tomofumi; Takao, Shouko; Jeelani, Ghulam; Hashimoto, Tetsuo; Hara, Hiromitsu; Nozaki, Tomoyoshi; Yoshida, Hiroki

2015-01-01

Hydrogenosomes and mitosomes are mitochondrion-related organelles (MROs) that have highly reduced and divergent functions in anaerobic/microaerophilic eukaryotes. Entamoeba histolytica, a microaerophilic, parasitic amoebozoan species, which causes intestinal and extraintestinal amoebiasis in humans, possesses mitosomes, the existence and biological functions of which have been a longstanding enigma in the evolution of mitochondria. We previously demonstrated that sulfate activation, which is not generally compartmentalized to mitochondria, is a major function of E. histolytica mitosomes. However, because the final metabolites of sulfate activation remain unknown, the overall scheme of this metabolism and the role of mitosomes in Entamoeba have not been elucidated. In this study we purified and identified cholesteryl sulfate (CS) as a final metabolite of sulfate activation. We then identified the gene encoding the cholesteryl sulfotransferase responsible for synthesizing CS. Addition of CS to culture media increased the number of cysts, the dormant form that differentiates from proliferative trophozoites. Conversely, chlorate, a selective inhibitor of the first enzyme in the sulfate-activation pathway, inhibited cyst formation in a dose-dependent manner. These results indicate that CS plays an important role in differentiation, an essential process for the transmission of Entamoeba between hosts. Furthermore, we show that Mastigamoeba balamuthi, an anaerobic, free-living amoebozoan species, which is a close relative of E. histolytica, also has the sulfate-activation pathway in MROs but does not possess the capacity for CS production. Hence, we propose that a unique function of MROs in Entamoeba contributes to its adaptation to its parasitic life cycle. PMID:25986376

Measurement uncertainty of ester number, acid number and patchouli alcohol of patchouli oil produced in Yogyakarta

NASA Astrophysics Data System (ADS)

Istiningrum, Reni Banowati; Saepuloh, Azis; Jannah, Wirdatul; Aji, Didit Waskito

2017-03-01

Yogyakarta is one of patchouli oil distillation center in Indonesia. The quality of patchouli oil greatly affect its market price. Therefore, testing quality of patchouli oil parameters is an important concern, one through determination of the measurement uncertainty. This study will determine the measurement uncertainty of ester number, acid number and content of patchouli alcohol through a bottom up approach. Source contributor to measurement uncertainty of ester number is a mass of the sample, a blank and sample titration volume, the molar mass of KOH, HCl normality, and replication. While the source contributor of the measurement uncertainty of acid number is the mass of the sample, the sample titration volume, the relative mass and normality of KOH, and repetition. Determination of patchouli alcohol by Gas Chromatography considers the sources of measurement uncertainty only from repeatability because reference materials are not available.

Myricetin down-regulates phorbol ester-induced cyclooxygenase-2 expression in mouse epidermal cells by blocking activation of nuclear factor kappa B.

PubMed

Lee, Kyung Mi; Kang, Nam Joo; Han, Jin Hee; Lee, Ki Won; Lee, Hyong Joo

2007-11-14

Abnormal expression of cyclooxygenase-2 (COX-2) has been implicated in the development of cancer. There are multiple lines of evidence that red wine exerts chemopreventive effects, and 3,5,4'-trihydroxy- trans-stilbene (resveratrol), which is a non-flavonoid polyphenol found in red wine, has been reported to be a natural chemopreventive agent. However, other phytochemicals might contribute to the cancer-preventive activities of red wine, and the flavonol content of red wines is about 30 times higher than that of resveratrol. Here we report that 3,3',4',5,5',7-hexahydroxyflavone (myricetin), one of the major flavonols in red wine, inhibits 12-O-tetradecanoylphorbol-13-acetate (phorbol ester)-induced COX-2 expression in JB6 P+ mouse epidermal (JB6 P+) cells by suppressing activation of nuclear factor kappa B (NF-kappaB). Myricetin at 10 and 20 microM inhibited phorbol ester-induced upregulation of COX-2 protein, while resveratrol at the same concentration did not exert significant effects. The phorbol ester-induced production of prostaglandin E 2 was also attenuated by myricetin treatment. Myricetin inhibited both COX-2 and NF-kappaB transactivation in phorbol ester-treated JB6 P+ cells, as determined using a luciferase assay. Myricetin blocked the phorbol ester-stimulated DNA binding activity of NF-kappaB, as determined using an electrophoretic mobility shift assay. Moreover, TPCK (N-tosyl-l-phenylalanine chloromethyl ketone), a NF-kappaB inhibitor, significantly attenuated COX-2 expression and NF-kappaB promoter activity in phorbol ester-treated JB6 P+ cells. In addition, red wine extract inhibited phorbol ester-induced COX-2 expression and NF-kappaB transactivation in JB6 P+ cells. Collectively, these data suggest that myricetin contributes to the chemopreventive effects of red wine through inhibition of COX-2 expression by blocking the activation of NF-kappaB.

Formation of Plant Sterol Oxidation Products in Foods during Baking and Cooking Using Margarine without and with Added Plant Sterol Esters.

PubMed

Lin, Yuguang; Knol, Diny; Menéndez-Carreño, María; Blom, Wendy A M; Matthee, Joep; Janssen, Hans-Gerd; Trautwein, Elke A

2016-01-27

Plant sterols (PS) in foods are subject to thermal oxidation to form PS oxidation products (POP). This study measured POP contents of 19 foods prepared by typical household baking and cooking methods using margarines without (control) and with 7.5% added PS (as 12.5% PS-esters, PS-margarine). Median POP contents per portion size of cooked foods were 0.57 mg (range 0.05-1.11 mg) with control margarine versus 1.42 mg (range 0.08-20.5 mg) with PS-margarine. The oxidation rate of PS (ORP) was 0.50% (median) with the PS-margarine and 3.66% with the control margarine. Using the PS-margarine, microwave-cooked codfish had the lowest POP content, with 0.08 mg per portion, while shallow-fried potatoes had the highest POP content, 20.5 mg per portion. Median POP contents in cookies, muffins, banana bread, and sponge cake baked with the control or PS-margarine were 0.12 mg (range 0.11-0.21 mg) and 0.24 mg (range 0.19-0.60 mg) per portion, with a corresponding ORP of 1.38% and 0.06%, respectively. POP contents in all the cooked and baked foods did not exceed 20.5 mg per typical portion size. A wide variation in the distribution of individual POP among different foods existed, with 7-keto-PS and 5,6-epoxy-PS being the major oxidation products.

Biodiesel production from ethanolysis of DPO using deep eutectic solvent (DES) based choline chloride - ethylene glycol as co-solvent

NASA Astrophysics Data System (ADS)

Taslim, Indra, Leonardo; Manurung, Renita; Winarta, Agus; Ramadhani, Debbie Aditia

2017-03-01

Biodiesel is usually produced from transesterification using methanol or ethanol as alcohol. However, biodiesel produced using methanol has several disadvantages because methanol is toxic and not entirely bio-based as it is generally produced from petroleum, natural gas and coal. On the other hand, ethanol also has several disadvantages such as lower reactivity in transesterification process and formation of stable emulsion between ester and glycerol. To improve ethanolysis process, deep eutectic solvent (DES) was prepared from choline chloride and ethylene glycol to be used as co-solvent in ethanolysis. Deep eutectic solvent was prepared by mixing choline chloride and ethylene glycol at molar ratio of 1:2, temperature of 80 °C, and stirring speed of 300 rpm for 1 hour. The DES was characterized by its density and viscosity. The ethanolysis of DPO / Degummed Palm Oil was performed at 70 °C, ethanol to oil molar ratio of 9:1, catalyst (potassium hydroxide) concentration of 0.75 wt.% concentration, co-solvent (DES) concentration of 1, 2, 3, 4, 5 and 6 wt.%, stirring speed of 600 rpm, and reaction time of 1 hour. The obtained biodiesel was then characterized by its density, viscosity and ester content. The oil - ethanol phase condition was observed in reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to that without DES. Which implied that oil and ethanol become more slightly miscible, which favours the reaction. Using DES as co-solvent in ethanolysis resulted in an increase in yield and easier purification. The esters properties met the international standards ASTM D6751, with highest yield achieved at 81.72 % with 99.35 % ethyl ester contents at 4% DES concentration.

Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

NASA Astrophysics Data System (ADS)

Miao, Fengping; Geng, Yahong; Lu, Dayan; Zuo, Jincheng; Li, Yeguang

2013-11-01

In this paper, we investigated the effects of temperature, oxygen, antioxidants, and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions, and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry. Oxygen and high temperatures (22-25°C) significantly reduced the stability of astaxanthin esters. Corn germ oil and antioxidants (ascorbic acid and vitamin E) failed to protect astaxanthin from oxidation, and actually significantly increased the instability of astaxanthin. A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage. During storage, the relative amounts of free astaxanthin and astaxanthin monoesters declined, while the relative amount of astaxanthin diesters increased. Thus, the ratio of astaxanthin diester to monoester increased, and this ratio could be used to indicate if astaxanthin esters have been properly preserved. If the ratio is greater than 0.2, it suggests that the decrease in astaxanthin content could be higher than 20%. Our results show that storing algal powder from H. pluvialis or other natural astaxanthin products under vacuum and in the dark below 4°C is the most economical and applicable storage method for the large-scale production of astaxanthin from H. pluvialis. This storage method can produce an astaxanthin preservation rate of at least 80% after 96 weeks of storage.

Phorbol esters inhibit smooth muscle contractions through activation of Na(+)-K(+)-ATPase.

PubMed Central

Sasaguri, T.; Watson, S. P.

1990-01-01

1. The role of protein kinase C (PKC) in agonist-induced contractions of guinea-pig ileum longitudinal smooth muscle has been investigated. 2. The phorbol esters, phorbol 12,13-dibutyrate (PDBu), phorbol 12,13-diacetate (PDA) and phorbol 12-myristate 13-acetate (PMA), relaxed tissues precontracted by submaximal concentrations of carbachol, histamine or substance P. 3. This inhibitory action of the phorbol esters was reversed following the application of ouabain, a specific inhibitor of Na(+)-K(+)-ATPase. Similarly, pretreatment with ouabain inhibited the ability of phorbol esters to relax tissues precontracted by the above agonists. 4. The slow relaxation of the tonic component of contraction induced by submaximal concentrations of carbachol and histamine, and all concentrations of substance P, was abolished in the presence of ouabain. 5. In Na(+)-loaded tissues, PDBu and carbachol caused a concentration-dependent increase of Na(+)-K(+)-ATPase activity, assessed by ouabain-sensitive 86Rb(+)-uptake. Extrusion of Na+, assessed by the cellular content of the ion, was also stimulated by PDBu (the effect of carbachol was not investigated). 6. We conclude that phorbol esters inhibit the tonic component of contractions induced by submaximal concentrations of these agonists through activation of Na(+)-K(+)-ATPase. We suggest that PKC may exert feedback control over the tonic component of agonist contractions through stimulation of the pump. PMID:1691673

Procedure for and results of simultaneous determination of aromatic hydrocarbons and fatty acid methyl esters in diesel fuels by high performance liquid chromatography.

PubMed

Kamiński, M; Gilgenast, E; Przyjazny, A; Romanik, G

2006-07-28

The content of aromatic hydrocarbons in diesel fuels is regulated by appropriate standards, and a further reduction in the allowed concentration of these hazardous substances in these fuels is expected. The content of aromatic hydrocarbons in diesel fuels is most often determined using standard methods EN-12916 or ASTM D-6591. The content of polycyclic aromatic hydrocarbons (PAHs) is determined from a single peak obtained using normal phase high-performance liquid chromatography (NP-HPLC), a column of the NH2 type, n-heptane as the eluent, refractive index detector (RID) and backflushing of the eluent. However, the methods mentioned above cannot be applied when the fuel contains fatty acid methyl esters (FAME), which lately has become more common. The content of FAME in diesel oils is determined using mid-IR spectrophotometry based on the absorption of carbonyl group. However, no standard procedure for the determination of classes of aromatic hydrocarbons in diesel fuels containing FAME is yet available. The present work describes such a modification of methods EN-12916/ASTM D-6591 that provides a simultaneous determination of individual groups of aromatic hydrocarbons, total content of polycyclic aromatic hydrocarbons and the FAME content in diesel fuels. The refractive index detector (RID) and n-heptane as the mobile phase are still used, but backflushing of the eluent is applied after the elution of all polycyclic aromatic hydrocarbons. Additionally, ultraviolet diode array detection is used for the exact determination of low contents of polycyclic aromatic hydrocarbons and to confirm the presence of FAME in the analyzed fuel.

Biodiesel production using fatty acids from food industry waste using corona discharge plasma technology.

PubMed

Cubas, A L V; Machado, M M; Pinto, C R S C; Moecke, E H S; Dutra, A R A

2016-01-01

This article aims to describe an alternative and innovative methodology to transform waste, frying oil in a potential energy source, the biodiesel. The biodiesel was produced from fatty acids, using a waste product of the food industry as the raw material. The methodology to be described is the corona discharge plasma technology, which offers advantages such as acceleration of the esterification reaction, easy separation of the biodiesel and the elimination of waste generation. The best conditions were found to be an oil/methanol molar ratio of 6:1, ambient temperature (25 °C) and reaction time of 110 min and 30 mL of sample. The acid value indicates the content of free fatty acids in the biodiesel and the value obtained in this study was 0.43 mg KOH/g. Peaks corresponding to octadecadienoic acid methyl ester, octadecanoic acid methyl ester and octadecenoic acid methyl ester, from the biodiesel composition, were identified using GC-MS. A major advantage of this process is that the methyl ester can be obtained in the absence of chemical catalysts and without the formation of the co-product (glycerin). Copyright © 2015 Elsevier Ltd. All rights reserved.

Discovery and characterizaton of a novel lipase with transesterification activity from hot spring metagenomic library.

PubMed

Yan, Wei; Li, Furong; Wang, Li; Zhu, Yaxin; Dong, Zhiyang; Bai, Linhan

2017-03-01

A new gene encoding a lipase (designated as Lip-1 ) was identified from a metagenomic bacterial artificial chromosome(BAC) library prepared from a concentrated water sample collected from a hot spring field in Niujie, Eryuan of Yunnan province in China. The open reading frame of this gene encoded 622 amino acid residues. It was cloned, fused with the oleosin gene and over expressed in Escherichia coli to prepare immobilized lipase artificial oil body AOB-sole-lip-1. The monomeric Sole-lip-1 fusion protein presented a molecular mass of 102.4 kDa. Enzyme assays using olive oil and methanol as the substrates in petroleum ether confirmed its transesterification activity. Hexadecanoic acid methyl ester, 8,11-Octadecadienoic acid methyl ester, 8-Octadecenoic acid methyl ester, and Octadecanoic acid methyl ester were detected. It showed favorable transesterification activity with optimal temperature 45 °C. Besides, the maximal biodiesel yield was obtained when the petroleum ether system as the organic solvent and the substrate methanol in 350 mmol/L (at a molar ratio of methanol of 10.5:1) and the water content was 1%. In light of these advantages, this lipase presents a promising resource for biodiesel production.

Thermal Decomposition of Methyl Esters in Biodiesel Fuel: Kinetics, Mechanisms and Products

NASA Astrophysics Data System (ADS)

Chai, Ming

Biodiesel continues to enjoy increasing popularity. However, recent studies on carbonyl compounds emissions from biodiesel fuel are inconclusive. Emissions of carbonyl compounds from petroleum diesel fuels were compared to emissions from pure biodiesel fuels and petroleum-biodiesel blends used in a non-road diesel generator. The concentration of total carbonyl compounds was the highest when the engine was idling. The carbonyl emissions, as well as ozone formation potential, from biodiesel fuel blends were higher than those emitted from petroleum diesel fuel. The sulfur content of diesel fuel and the source of biodiesel fuel were not found to have a significant impact on emissions of carbonyl compounds. Mechanism parameters of the thermal decomposition of biodiesel-range methyl esters were obtained from the results of thermal gravimetric analysis (TGA). The overall reaction orders are between 0.49 and 0.71 and the energies of activation are between 59.9 and 101.3 kJ/mole. Methyl esters in air have lower activation energies than those in nitrogen. Methyl linoleate has the lowest activation energy, followed by methyl oleate, and methyl stearate. The pyrolysis and oxidation of the three methyl esters were investigated using a semi-isothermal tubular flow reactor. The profiles of major products versus reaction temperature are presented. In the pyrolysis of methyl stearate, the primary reaction pathway is the decarboxylic reaction at the methyl ester functional group. Methyl oleate's products indicate more reactions on its carbon-carbon double bond. Methyl linoleate shows highest reactivity among the three methyl esters, and 87 products were detected. The oxidation of three methyl esters resulted in more products in all compound classes, and 55, 114, and 127 products were detected, respectively. The oxidation of methyl esters includes decarboxylation on ester group. The methyl ester's carbon chain could be oxidized as a hydrocarbon compound and form oxidized esters and unsaturated esters, which have been observed in methyl ester's oxidation products. The oxidation of methyl stearate, methyl oleate and methyl linoleate produces 16, 28 and 34 types of carbonyl compounds, respectively. The unsaturated methyl ester forms more carbonyl compounds compared to the saturated methyl ester, which indicates the formation of carbonyl compounds might be more related to the unsaturated carbon bond rather than the methyl ester group. Good agreement between results for total carbon (TC) generally has been found, but the organic and elemental carbon (OC and EC) fractions determined by different methods often disagree. Lack of reference materials has impeded progress on method standardization and understanding method biases. As part of this dissertation, uniform carbon distribution for the filter sets is prepared by using a simply aerosol generation and collection method. The relative standard deviations for the mean TC, OC, and EC results reported by the seven laboratories were below 10%, 11% and 12% (respectively). The method of filter generation is generally applicable and reproducible. Depending on the application, different filter loadings and types of OC materials can be employed. Matched filter sets prepared by this approach can be used for determining the accuracy of various OC-EC methods and thereby contribute to method standardization.

Serum Fatty Acids, Desaturase Activities and Abdominal Obesity – A Population-Based Study of 60-Year Old Men and Women

PubMed Central

Alsharari, Zayed D.; Risérus, Ulf; Leander, Karin; Sjögren, Per; Carlsson, Axel C.; Vikström, Max; Laguzzi, Federica; Gigante, Bruna; Cederholm, Tommy; De Faire, Ulf; Hellénius, Mai-Lis

2017-01-01

Abdominal obesity is a key contributor of metabolic disease. Recent trials suggest that dietary fat quality affects abdominal fat content, where palmitic acid and linoleic acid influence abdominal obesity differently, while effects of n-3 polyunsaturated fatty acids are less studied. Also, fatty acid desaturation may be altered in abdominal obesity. We aimed to investigate cross-sectional associations of serum fatty acids and desaturases with abdominal obesity prevalence in a population-based cohort study. Serum cholesteryl ester fatty acids composition was measured by gas chromatography in 60-year old men (n = 1883) and women (n = 2015). Cross-sectional associations of fatty acids with abdominal obesity prevalence and anthropometric measures (e.g., sagittal abdominal diameter) were evaluated in multivariable-adjusted logistic and linear regression models, respectively. Similar models were employed to investigate relations between desaturase activities (estimated by fatty acid ratios) and abdominal obesity. In logistic regression analyses, palmitic acid, stearoyl-CoA-desaturase and Δ6-desaturase indices were associated with abdominal obesity; multivariable-adjusted odds ratios (95% confidence intervals) for highest versus lowest quartiles were 1.45 (1.19–1.76), 4.06 (3.27–5.05), and 3.07 (2.51–3.75), respectively. Linoleic acid, α-linolenic acid, docohexaenoic acid, and Δ5-desaturase were inversely associated with abdominal obesity; multivariable-adjusted odds ratios (95% confidence intervals): 0.39 (0.32–0.48), 0.74 (0.61–0.89), 0.76 (0.62–0.93), and 0.40 (0.33–0.49), respectively. Eicosapentaenoic acid was not associated with abdominal obesity. Similar results were obtained from linear regression models evaluating associations with different anthropometric measures. Sex-specific and linear associations were mainly observed for n3-polyunsaturated fatty acids, while associations of the other exposures were generally non-linear and similar across sexes. In accordance with findings from short-term trials, abdominal obesity was more common among individuals with relatively high proportions of palmitic acid, whilst the contrary was true for linoleic acid. Further trials should examine the potential role of linoleic acid and its main dietary source, vegetable oils, in abdominal obesity prevention. PMID:28125662

Defective macroautophagic turnover of brain lipids in the TgCRND8 Alzheimer mouse model: prevention by correcting lysosomal proteolytic deficits.

PubMed

Yang, Dun-Sheng; Stavrides, Philip; Saito, Mitsuo; Kumar, Asok; Rodriguez-Navarro, Jose A; Pawlik, Monika; Huo, Chunfeng; Walkley, Steven U; Saito, Mariko; Cuervo, Ana M; Nixon, Ralph A

2014-12-01

Autophagy, the major lysosomal pathway for the turnover of intracellular organelles is markedly impaired in neurons in Alzheimer's disease and Alzheimer mouse models. We have previously reported that severe lysosomal and amyloid neuropathology and associated cognitive deficits in the TgCRND8 Alzheimer mouse model can be ameliorated by restoring lysosomal proteolytic capacity and autophagy flux via genetic deletion of the lysosomal protease inhibitor, cystatin B. Here we present evidence that macroautophagy is a significant pathway for lipid turnover, which is defective in TgCRND8 brain where lipids accumulate as membranous structures and lipid droplets within giant neuronal autolysosomes. Levels of multiple lipid species including several sphingolipids (ceramide, ganglioside GM3, GM2, GM1, GD3 and GD1a), cardiolipin, cholesterol and cholesteryl esters are elevated in autophagic vacuole fractions and lysosomes isolated from TgCRND8 brain. Lipids are localized in autophagosomes and autolysosomes by double immunofluorescence analyses in wild-type mice and colocalization is increased in TgCRND8 mice where abnormally abundant GM2 ganglioside-positive granules are detected in neuronal lysosomes. Cystatin B deletion in TgCRND8 significantly reduces the number of GM2-positive granules and lowers the levels of GM2 and GM3 in lysosomes, decreases lipofuscin-related autofluorescence, and eliminates giant lipid-containing autolysosomes while increasing numbers of normal-sized autolysosomes/lysosomes with reduced content of undigested components. These findings have identified macroautophagy as a previously unappreciated route for delivering membrane lipids to lysosomes for turnover, a function that has so far been considered to be mediated exclusively through the endocytic pathway, and revealed that autophagic-lysosomal dysfunction in TgCRND8 brain impedes lysosomal turnover of lipids as well as proteins. The amelioration of lipid accumulation in TgCRND8 by removing cystatin B inhibition on lysosomal proteases suggests that enhancing lysosomal proteolysis improves the overall environment of the lysosome and its clearance functions, which may be possibly relevant to a broader range of lysosomal disorders beyond Alzheimer's disease. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats.

PubMed

Baldin, M; Gama, M A S; Dresch, R; Harvatine, K J; Oliveira, D E

2013-07-01

Feeding trans-10, cis-12 CLA supplements in a rumen-protected form has been shown to cause milk fat depression (MFD) in cows, ewes, and goats. Methyl esters of CLA were shown to be as effective as FFA in inducing MFD when infused postruminally, but their efficacy as a feed supplement has not been addressed in studies with lactating ruminants. In the present study, we investigated the effects of an unprotected trans-10, cis-12 CLA supplement as methyl esters on performance, milk composition, and energy status of dairy goats. Eighteen multiparous Toggenburg goats were randomly assigned to dietary treatments in a crossover experimental design (14 d treatment periods separated by a 7 d washout interval): 30 g/d of calcium salts of fatty acids (Control) or 30 g/d of a rumen unprotected CLA supplement containing 29.9% of trans-10, cis-12 CLA as methyl esters (CLA). Lipid supplements were mixed into a concentrate and fed individually to animals 3 times a day as a total mixed ration component. The DMI, milk yield, milk protein and lactose content and secretion, and somatic cell count were unaffected by CLA treatment. On the other hand, milk fat content and yield were reduced by 19.9 and 17.9% in CLA-fed goats. Reduced milk fat yield in CLA-fed goats was a consequence of a lower secretion of both preformed and de novo synthesized fatty acids. The CLA treatment also changed the milk fatty acid profile, which included a reduction in the concentration of SFA (2.5%), increased MUFA and PUFA (5.6 and 5.4%, respectively), and a pronounced increase (1576%) in milk fat trans-10, cis-12 CLA. Consistent with the high milk fat trans-10, cis-12 CLA content, all desaturase indexes were reduced in milk fat from CLA-fed goats. The MFD induced by CLA reduced the energy required for milk production by 22%, which was accompanied by an improvement in the estimated energy balance (P < 0.001), greater blood glucose concentration (P < 0.05), and a trend for increased BW (P = 0.08). Approximately 7.2% of trans-10, cis-12 CLA was estimated to escape from rumen biohydrogenation and indirect comparisons with data obtained from other studies suggest equivalent MFD between dietary CLA in the methyl ester form and rumen protected sources. Thus, despite the apparent low degree of rumen protection, our results suggest that methyl esters of CLA could be an alternative to rumen protected CLA supplements due to manufacturing and cost advantages.

Toxicity studies of detoxified Jatropha meal (Jatropha curcas) in rats.

PubMed

Rakshit, K D; Darukeshwara, J; Rathina Raj, K; Narasimhamurthy, K; Saibaba, P; Bhagya, S

2008-12-01

Jatropha curcas, a tropical plant introduced in many Asian and African countries is presently used as a source of biodiesel. The cake after oil extraction is rich in protein and is a potential source of livestock feed. In view of the high toxic nature of whole as well as dehulled seed meal due to the presence of toxic phorbol esters and lectin, the meal was subjected to alkali and heat treatments to deactivate the phorbol ester as well as lectin content. After treatment, the phorbol ester content was reduced up to 89% in whole and dehulled seed meal. Toxicity studies were conducted on male growing rats by feeding treated as well as untreated meal through dietary source. All rats irrespective of treatment had reduced appetite and diet intake was low accompanied by diarrhoea. The rats also exhibited reduced motor activity. The rats fed with treated meals exhibited delayed mortality compared to untreated meal fed rats (p0.02). There were significant changes both in terms of food intake and gain in body weight. Gross examination of vital organs indicated atrophy compared to control casein fed rats. However, histopathological examination of various vital organs did not reveal any treatment related microscopic changes suggesting that the mortality of rats occurred due to lack of food intake, diarrhoea and emaciation. Further studies are in progress for complete detoxification of J. curcas meal for use in livestock feed.

Identification of volatile compound markers during the ripening and senescence of lulo (Solanum quitoense Lam.).

PubMed

Corpas Iguarán, Eduardo; Taborda Ocampo, Gonzalo; Tapasco Alzate, Omar

2018-01-01

Lulo ( Solanum quitoense Lam.) is an exotic fruit cultivated in Colombia. During ripening and senescence, this climactic fruit undergoes biochemical processes that produce the volatiles responsible for its aroma. This study aimed to evaluate the changes in the volatile content during the ripening and senescence of lulo. Analysis of the volatile composition of lulo harvested in each of its five ripening stages and during its senescence time when stored at 18 ± 2 °C was performed using HS-SPME with GC-MS. Throughout ripening, the most notable change was the transformation of alcohols such as (Z)-3-hexen-1-ol and 1-penten-3-ol to afford esters such as (Z)-3-hexenyl acetate and ketones such as 1-penten-3-one. Some acids reacted with alcohols to produce acetate and hexanoate esters, concentrations which increased more than sixfold between stage one and five. Moreover, all the major compounds were C 6 straight chain compounds related to the lipoxygenase pathway. During senescence, majority of compounds were methyl esters, which increased in concentration consistently until day eight. Remarkably, the content of methyl butanoate increased from 0.9% of the total amount of volatiles on day two up to 76.4% on day eight. Some of these volatiles are probably contributors to the "off flavor" during senescence.

Influence of Production Method on the Chemical Composition, Foaming Properties, and Quality of Australian Carbonated and Sparkling White Wines.

PubMed

Culbert, Julie A; McRae, Jacqui M; Condé, Bruna C; Schmidtke, Leigh M; Nicholson, Emily L; Smith, Paul A; Howell, Kate S; Boss, Paul K; Wilkinson, Kerry L

2017-02-22

The chemical composition (protein, polysaccharide, amino acid, and fatty acid/ethyl ester content), foaming properties, and quality of 50 Australian sparkling white wines, representing the four key production methods, that is, Méthode Traditionelle (n = 20), transfer (n = 10), Charmat (n = 10), and carbonation (n = 10), were studied. Méthode Traditionelle wines were typically rated highest in quality and were higher in alcohol and protein contents, but lower in residual sugar and total phenolics, than other sparkling wines. They also exhibited higher foam volume and stability, which might be attributable to higher protein concentrations. Bottle-fermented Méthode Traditionelle and transfer wines contained greater proportions of yeast-derived mannoproteins, whereas Charmat and carbonated wines were higher in grape-derived rhamnogalacturonans; however, total polysaccharide concentrations were not significantly different between sparkling wine styles. Free amino acids were most abundant in carbonated wines, which likely reflects production via primary fermentation only and/or the inclusion of nontraditional grape varieties. Fatty acids and their esters were not correlated with foaming properties, but octanoic and decanoic acids and their ethyl esters were present in Charmat and carbonated wines at significantly higher concentrations than in bottle-fermented wines and were negatively correlated with quality ratings. Research findings provide industry with a better understanding of the compositional factors driving the style and quality of sparkling white wine.

Comparison of volatile and non-volatile metabolites in rice wine fermented by Koji inoculated with Saccharomycopsis fibuligera and Aspergillus oryzae.

PubMed

Son, Eun Yeong; Lee, Sang Mi; Kim, Minjoo; Seo, Jeong-Ah; Kim, Young-Suk

2018-07-01

This study investigated volatile and nonvolatile metabolite profiles of makgeolli (a traditional rice wine in Korea) fermented by koji inoculated with Saccharomycopsis fibuligera and/or Aspergillus oryzae. The enzyme activities in koji were also examined to determine their effects on the formation of metabolites. The contents of all 18 amino acids detected were the highest in makgeolli fermented by S. fibuligera CN2601-09, and increased after combining with A. oryzae CN1102-08, unlike the contents of most fatty acids. On the other hand, major volatile metabolites were fusel alcohols, acetate esters, and ethyl esters. The contents of most fusel alcohols and acetate esters were the highest in makgeolli fermented by S. fibuligera CN2601-09, for which the protease activity was the highest, leading to the largest amounts of amino acods. The makgeolli samples fermented only by koji inoculated with S. fibuligera could be discriminated on PCA plots from the makgeolli samples fermented in combination with A. oryzae. In the case of nonvolatile metabolites, all amino acids and some metabolites such as xylose, 2-methylbenzoic acid, and oxalic acid contributed mainly to the characteristics of makgeolli fermented by koji inoculated with S. fibuligera and A. oryzae. These results showed that the formations of volatile and nonvolatile metabolites in makgeolli can be significantly affected by microbial strains with different enzyme activities in koji. To our knowledge, this study is the first report on the effects of S. fibuligera strains on the formation of volatile and non-volatile metabolites in rice wine, facilitating their use in brewing rice wine. Copyright © 2018. Published by Elsevier Ltd.

Aroma characterization based on aromatic series analysis in table grapes

PubMed Central

Wu, Yusen; Duan, Shuyan; Zhao, Liping; Gao, Zhen; Luo, Meng; Song, Shiren; Xu, Wenping; Zhang, Caixi; Ma, Chao; Wang, Shiping

2016-01-01

Aroma is an important part of quality in table grape, but the key aroma compounds and the aroma series of table grapes remains unknown. In this paper, we identified 67 aroma compounds in 20 table grape cultivars; 20 in pulp and 23 in skin were active compounds. C6 compounds were the basic background volatiles, but the aroma contents of pulp juice and skin depended mainly on the levels of esters and terpenes, respectively. Most obviously, ‘Kyoho’ grapevine series showed high contents of esters in pulp, while Muscat/floral cultivars showed abundant monoterpenes in skin. For the aroma series, table grapes were characterized mainly by herbaceous, floral, balsamic, sweet and fruity series. The simple and visualizable aroma profiles were established using aroma fingerprints based on the aromatic series. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) showed that the aroma profiles of pulp juice, skin and whole berries could be classified into 5, 3, and 5 groups, respectively. Combined with sensory evaluation, we could conclude that fatty and balsamic series were the preferred aromatic series, and the contents of their contributors (β-ionone and octanal) may be useful as indicators for the improvement of breeding and cultivation measures for table grapes. PMID:27487935

Advances in the management of dyslipidemia.

PubMed

Kampangkaew, June; Pickett, Stephen; Nambi, Vijay

2017-07-01

Cardiovascular disease is the leading cause of morbidity and mortality in the United States and therapies aimed at lipid modification are important for the reduction of cardiovascular risk. There have been many exciting advances in lipid management over the recent years. This review discusses these recent advances as well as the direction of future studies. Several recent clinical trials support low-density lipoprotein cholesterol (LDL-c) reduction beyond maximal statin therapy for improved cardiovascular outcomes. Ezetimibe reduced LDL-c beyond maximal statin therapy and was associated with improved cardiovascular outcomes for high-risk populations. Further LDL-c reduction may also be achieved with proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibition and a recent trial, Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER), was the first to show reduction in cardiovascular events for evolocumab. Additional outcome studies of monoclonal antibody and RNA-targeted PCSK9 inhibitors are underway. Quantitative high-density lipoprotein cholesterol (HDL-c) improvements have failed to have clinical impact to date; most recently, cholesteryl ester transfer protein inhibitors and apolipoprotein infusions have demonstrated disappointing results. There are still ongoing trials in both of these areas, but some newer therapies are focusing on HDL functionality and not just the absolute HDL-c levels. There are several ongoing studies in triglyceride reduction including fatty acid therapy, inhibition of apolipoprotein C-3 or ANGTPL3 and peroxisome proliferator-activated receptor-α agonists. Lipid management continues to evolve and these advances have the potential to change clinical practice in the coming years.

Low-level expression of human ACAT2 gene in monocytic cells is regulated by the C/EBP transcription factors

PubMed Central

Guo, Dongqing; Lu, Ming; Hu, Xihan; Xu, Jiajia; Hu, Guangjing; Zhu, Ming; Zhang, Xiaowei; Li, Qin; Chang, Catherine C. Y.; Chang, Tayuan; Song, Baoliang; Xiong, Ying; Li, Boliang

2016-01-01

Acyl-coenzyme A:cholesterol acyltransferases (ACATs) are the exclusive intracellular enzymes that catalyze the formation of cholesteryl/steryl esters (CE/SE). In our previous work, we found that the high-level expression of human ACAT2 gene with the CpG hypomethylation of its whole promoter was synergistically regulated by two transcription factors Cdx2 and HNF1α in the intestine and fetal liver. Here, we first observed that the specific CpG-hypomethylated promoter was correlated with the low expression of human ACAT2 gene in monocytic cell line THP-1. Then, two CCAAT/enhancer binding protein (C/EBP) elements within the activation domain in the specific CpG-hypomethylation promoter region were identified, and the expression of ACAT2 in THP-1 cells was evidently decreased when the C/EBP transcription factors were knock-downed using RNAi technology. Furthermore, ChIP assay confirmed that C/EBPs directly bind to their elements for low-level expression of human ACAT2 gene in THP-1 cells. Significantly, the increased expressions of ACAT2 and C/EBPs were also found in macrophages differentiated from both ATRA-treated THP-1 cells and cultured human blood monocytes. These results demonstrate that the low-level expression of human ACAT2 gene with specific CpG-hypomethylated promoter is regulated by the C/EBP transcription factors in monocytic cells, and imply that the lowly expressed ACAT2 catalyzes the synthesis of certain CE/SE that are assembled into lipoproteins for the secretion. PMID:27688151

Chronic Exercise Reduces CETP and Mesterolone Treatment Counteracts Exercise Benefits on Plasma Lipoproteins Profile: Studies in Transgenic Mice.

PubMed

Casquero, Andrea Camargo; Berti, Jairo Augusto; Teixeira, Laura Lauand Sampaio; de Oliveira, Helena Coutinho Franco

2017-12-01

Regular exercise and anabolic androgenic steroids have opposing effects on the plasma lipoprotein profile and risk of cardio-metabolic diseases in humans. Studies in humans and animal models show conflicting results. Here, we used a mice model genetically modified to mimic human lipoprotein profile and metabolism. They under-express the endogenous LDL receptor gene (R1) and express a human transgene encoding the cholesteryl ester transfer protein (CETP), normally absent in mice. The present study was designed to evaluate the independent and interactive effects of testosterone supplementation, exercise training and CETP expression on the plasma lipoprotein profile and CETP activity. CETP/R1 and R1 mice were submitted to a 6-week swimming training and mesterolone (MEST) supplementation in the last 3 weeks. MEST treatment increased markedly LDL levels (40%) in sedentary CETP/R1 mice and reduced HDL levels in exercised R1 mice (18%). A multifactorial ANOVA revealed the independent effects of each factor, as follows. CETP expression reduced HDL (21%) and increased non-HDL (15%) fractions. MEST treatment increased the VLDL concentrations (42%) regardless of other interventions. Exercise training reduced triacylglycerol (25%) and free fatty acids (20%), increased both LDL and HDL (25-33%), and reduced CETP (19%) plasma levels. Significant factor interactions showed that the increase in HDL induced by exercise is explained by reducing CETP activity and that MEST blunted the exercise-induced elevation of HDL-cholesterol. These results reinforce the positive metabolic effects of exercise, resolved a controversy about CETP response to exercise and evidenced MEST potency to counteract specific exercise benefits.

Fatty Acid Profile of Sunshine Bass: II. Profile Change Differs Among Fillet Lipid Classes.

PubMed

Trushenski, Jesse T; Lewis, Heidi A; Kohler, Christopher C

2008-07-01

Fatty acid (FA) profile of fish tissue mirrors dietary FA profile and changes in a time-dependent manner following a change in dietary FA composition. To determine whether FA profile change varies among lipid classes, we evaluated the FA composition of fillet cholesteryl esters (CE), phospholipids (PL), and triacylglycerols (TAG) of sunshine bass (SB, Morone chrysops x M. saxatilis) raised on feeds containing fish oil or 50:50 blend of fish oil and coconut, grapeseed, linseed, or poultry oil, with or without implementation of a finishing period (100% FO feed) prior to harvest. Each lipid class was associated with a generalized FA signature, irrespective of nutritional history: fillet PL was comprised largely of saturated FA (SFA), long-chain polyunsaturated FA (LC-PUFA), and total n-3 FA; fillet TAG was higher in MC-PUFA and total n-6 FA; and fillet CE was highest in monounsaturated FA (MUFA). Neutral lipids reflected dietary composition in a near-direct fashion; conversely, PL showed evidence of selectivity for MC- and LC-PUFA. Shorter-chain SFA were not strongly reflected within any lipid fraction, even when dietary availability was high, suggesting catabolism of these FA. FA metabolism in SB is apparently characterized by a division between saturated and unsaturated FA, whereby LC-PUFA are preferentially incorporated into tissues and SFA are preferentially oxidized for energy production. We demonstrated provision of SFA in grow-out feeds for SB, instead MC-PUFA which compete for tissue deposition, meets energy demands and allows for maximum inclusion of LC-PUFA within fillet lipids.

Intracellular cholesterol transport proteins enhance hydrolysis of HDL-CEs and facilitate elimination of cholesterol into bile.

PubMed

Wang, Jing; Bie, Jinghua; Ghosh, Shobha

2016-09-01

While HDL-associated unesterified or free cholesterol (FC) is thought to be rapidly secreted into the bile, the fate of HDL-associated cholesteryl esters (HDL-CEs) that represent >80% of HDL-cholesterol, is only beginning to be understood. In the present study, we examined the hypothesis that intracellular cholesterol transport proteins [sterol carrier protein 2 (SCP2) and fatty acid binding protein-1 (FABP1)] not only facilitate CE hydrolase-mediated hydrolysis of HDL-CEs, but also enhance elimination of cholesterol into bile. Adenovirus-mediated overexpression of FABP1 or SCP2 in primary hepatocytes significantly increased hydrolysis of HDL-[(3)H]CE, reduced resecretion of HDL-CE-derived FC as nascent HDL, and increased its secretion as bile acids. Consistently, the flux of [(3)H]cholesterol from HDL-[(3)H]CE to biliary bile acids was increased by overexpression of SCP2 or FABP1 in vivo and reduced in SCP2(-/-) mice. Increased flux of HDL-[(3)H]CE to biliary FC was noted with FABP1 overexpression and in SCP2(-/-) mice that have increased FABP1 expression. Lack of a significant decrease in the flux of HDL-[(3)H]CE to biliary FC or bile acids in FABP1(-/-) mice indicates the likely compensation of its function by an as yet unidentified mechanism. Taken together, these studies demonstrate that FABP1 and SCP2 facilitate the preferential movement of HDL-CEs to bile for final elimination. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Intracellular cholesterol transport proteins enhance hydrolysis of HDL-CEs and facilitate elimination of cholesterol into bile

PubMed Central

Wang, Jing; Bie, Jinghua; Ghosh, Shobha

2016-01-01

While HDL-associated unesterified or free cholesterol (FC) is thought to be rapidly secreted into the bile, the fate of HDL-associated cholesteryl esters (HDL-CEs) that represent >80% of HDL-cholesterol, is only beginning to be understood. In the present study, we examined the hypothesis that intracellular cholesterol transport proteins [sterol carrier protein 2 (SCP2) and fatty acid binding protein-1 (FABP1)] not only facilitate CE hydrolase-mediated hydrolysis of HDL-CEs, but also enhance elimination of cholesterol into bile. Adenovirus-mediated overexpression of FABP1 or SCP2 in primary hepatocytes significantly increased hydrolysis of HDL-[3H]CE, reduced resecretion of HDL-CE-derived FC as nascent HDL, and increased its secretion as bile acids. Consistently, the flux of [3H]cholesterol from HDL-[3H]CE to biliary bile acids was increased by overexpression of SCP2 or FABP1 in vivo and reduced in SCP2−/− mice. Increased flux of HDL-[3H]CE to biliary FC was noted with FABP1 overexpression and in SCP2−/− mice that have increased FABP1 expression. Lack of a significant decrease in the flux of HDL-[3H]CE to biliary FC or bile acids in FABP1−/− mice indicates the likely compensation of its function by an as yet unidentified mechanism. Taken together, these studies demonstrate that FABP1 and SCP2 facilitate the preferential movement of HDL-CEs to bile for final elimination. PMID:27381048

Gene-diet interaction of a common FADS1 variant with marine polyunsaturated fatty acids for fatty acid composition in plasma and erythrocytes among men.

PubMed

Takkunen, Markus J; de Mello, Vanessa D; Schwab, Ursula S; Kuusisto, Johanna; Vaittinen, Maija; Ågren, Jyrki J; Laakso, Markku; Pihlajamäki, Jussi; Uusitupa, Matti I J

2016-02-01

Limited information exists on how the relationship between dietary intake of fat and fatty acids in erythrocytes and plasma is modulated by polymorphisms in the FADS gene cluster. We examined gene-diet interaction of total marine PUFA intake with a known gene encoding Δ-5 desaturase enzyme (FADS1) variant (rs174550) for fatty acids in erythrocyte membranes and plasma phospholipids (PL), cholesteryl esters (CE), and triglycerides (TG). In this cross-sectional study, fatty acid compositions were measured using GC, and total intake of polyunsaturated fat from fish and fish oil was estimated using a food frequency questionnaire in a subsample (n = 962) of the Metabolic Syndrome in Men Study. We found nominally significant gene-diet interactions for eicosapentaenoic acid (EPA, 20:5n-3) in erythrocytes (pinteraction = 0.032) and for EPA in plasma PL (pinteraction = 0.062), CE (pinteraction = 0.035), and TG (pinteraction = 0.035), as well as for docosapentaenoic acid (22:5n-3) in PL (pinteraction = 0.007). After excluding omega-3 supplement users, we found a significant gene-diet interaction for EPA in erythrocytes (pinteraction < 0.003). In a separate cohort of the Kuopio Obesity Surgery Study, the same locus was strongly associated with hepatic mRNA expression of FADS1 (p = 1.5 × 10(-10) ). FADS1 variants may modulate the relationship between marine fatty acid intake and circulating levels of long-chain omega-3 fatty acids. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preventing cardiovascular heart disease: Promising nutraceutical and non-nutraceutical treatments for cholesterol management.

PubMed

Johnston, T P; Korolenko, T A; Pirro, M; Sahebkar, A

2017-06-01

Hypercholesterolemia is one of the major risk factors for the development of cardiovascular disease. Atherosclerosis resulting from hypercholesterolemia causes many serious cardiovascular diseases. Statins are generally accepted as a treatment of choice for lowering low-density lipoprotein (LDL) cholesterol, which reduces coronary heart disease morbidity and mortality. Since statin use can be associated with muscle problems and other adverse symptoms, non-adherence and discontinuation of statin therapy often leads to inadequate control of plasma cholesterol levels and increased cardiovascular risk. Moreover, there is compelling evidence on the presence of still considerable residual cardiovascular risk in statin-treated patients. Ezetimibe improves cholesterol-lowering efficacy and provides mild additional cardiovascular protection when combined with statin treatment. Despite a favorable safety profile compared to statins, ezetimibe-induced cholesterol-lowering is modest when used alone. Hence, there is a critical need to identity additional effective hypolipidemic agents that can be used either in combination with statins, or alone, if statins are not tolerated. Thus, hypolipidemic agents such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, apolipoprotein B-100 antisense oligonucleotides, cholesteryl ester transfer protein (CETP) inhibitors, and microsomal triglyceride transfer protein (MTTP) inhibitors, as well as yeast polysaccharides (beta-glucans and mannans) and compounds derived from natural sources (nutraceuticals) such as glucomannans, plant sterols, berberine, and red yeast rice are being used. In this review, we will discuss hypercholesterolemia, its impact on the development of cardiovascular disease (CVD), and the use of yeast polysaccharides, various nutraceuticals, and several therapeutic agents not derived from 'natural' sources, to treat hypercholesterolemia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Negatively Cooperative Binding of High Density Lipoprotein to the HDL Receptor SR-BI†

PubMed Central

Nieland, Thomas J.F.; Xu, Shangzhe; Penman, Marsha; Krieger, Monty

2011-01-01

Scavenger receptor class B, type I (SR-BI) is a high-density lipoprotein (HDL) receptor, which also binds low density lipoprotein (LDL), and mediates the cellular selective uptake of cholesteryl esters from lipoproteins. SR-BI also is a co-receptor for hepatitis C virus and a signaling receptor that regulates cell metabolism. Many investigators have reported that lipoproteins bind to SR-BI via a single class of independent (not interacting), high affinity binding sites (one site model). We have re-investigated the ligand concentration dependence of 125I-HDL binding to SR-BI and SR-BI-mediated specific uptake of [3H]CE from [3H]CE-HDL using an expanded range of ligand concentrations (<1 µg protein/ml, lower than previously reported). Scatchard and non-linear least squares model fitting analyses of the binding and uptake data were both inconsistent with a single class of independent binding sites binding univalent lipoprotein ligands. The data are best fit by models in which SR-BI has either two independent classes of binding sites, or one class of sites exhibiting negative cooperativity due to either classic allostery or ensemble effects (‘ lattice model’). Similar results were observed for LDL. Application of the ‘infinite dilution’ dissociation rate method established that the binding of 125I-HDL to SR-BI at 4 °C exhibits negative cooperativity. The unexpected complexity of the interactions of lipoproteins with SR-BI should be taken into account when interpreting the results of experiments that explore the mechanism(s) by which SR-BI mediates ligand binding, lipid transport and cell signaling. PMID:21254782

Effect of sardine proteins on hyperglycaemia, hyperlipidaemia and lecithin:cholesterol acyltransferase activity, in high-fat diet-induced type 2 diabetic rats.

PubMed

Benaicheta, Nora; Labbaci, Fatima Z; Bouchenak, Malika; Boukortt, Farida O

2016-01-14

Type 2 diabetes (T2D) is a major risk factor of CVD. The effects of purified sardine proteins (SP) were examined on glycaemia, insulin sensitivity and reverse cholesterol transport in T2D rats. Rats fed a high-fat diet (HFD) for 5 weeks, and injected with a low dose of streptozotocin, were used. The diabetic rats were divided into four groups, and they were fed casein (CAS) or SP combined with 30 or 5% lipids, for 4 weeks. HFD-induced hyperglycaemia, insulin resistance and hyperlipidaemia in rats fed HFD, regardless of the consumed protein. In contrast, these parameters lowered in rats fed SP combined with 5 or 30% lipids, and serum insulin values reduced in SP v. CAS. HFD significantly increased total cholesterol and TAG concentrations in the liver and serum, whereas these parameters decreased with SP, regardless of lipid intake. Faecal cholesterol excretion was higher with SP v. CAS, combined with 30 or 5% lipids. Lecithin:cholesterol acyltransferase (LCAT) activity and HDL3-phospholipids (PL) were higher in CAS-HF than in CAS, whereas HDL2-cholesteryl esters (CE) were lower. Otherwise, LCAT activity and HDL2-CE were higher in the SP group than in the CAS group, whereas HDL3-PL and HDL3-unesterified cholesterol were lower. Moreover, LCAT activity lowered in the SP-HF group than in the CAS-HF group, when HDL2-CE was higher. In conclusion, these results indicate the potential effects of SP to improve glycaemia, insulin sensitivity and reverse cholesterol transport, in T2D rats.

Computational Analysis of Sterol Ligand Specificity of the Niemann Pick C2 Protein.

PubMed

Poongavanam, Vasanthanathan; Kongsted, Jacob; Wüstner, Daniel

2016-09-13

Transport of cholesterol derived from hydrolysis of lipoprotein associated cholesteryl esters out of late endosomes depends critically on the function of the Niemann Pick C1 (NPC1) and C2 (NPC2) proteins. Both proteins bind cholesterol but also various other sterols and both with strongly varying affinity. The molecular mechanisms underlying this multiligand specificity are not known. On the basis of the crystal structure of NPC2, we have here investigated structural details of NPC2-sterol interactions using molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations. We found that an aliphatic side chain in the sterol ligand results in strong binding to NPC2, while side-chain oxidized sterols gave weaker binding. Estradiol and the hydrophobic amine U18666A had the lowest affinity of all tested ligands and at the same time showed the highest flexibility within the NPC2 binding pocket. The binding affinity of all ligands correlated highly with their calculated partitioning coefficient (logP) between octanol/water phases and with the potential of sterols to stabilize the protein backbone. From molecular dynamics simulations, we suggest a general mechanism for NPC2 mediated sterol transfer, in which Phe66, Val96, and Tyr100 act as reversible gate keepers. These residues stabilize the sterol in the binding pose via π-π stacking but move transiently apart during sterol release. A computational mutation analysis revealed that the binding of various ligands depends critically on the same specific amino acid residues within the binding pocket providing shape complementary to sterols, but also on residues in distal regions of the protein.

A Lipolytic Lecithin:Cholesterol Acyltransferase Secreted by Toxoplasma Facilitates Parasite Replication and Egress*

PubMed Central

Pszenny, Viviana; Ehrenman, Karen; Romano, Julia D.; Kennard, Andrea; Schultz, Aric; Roos, David S.; Grigg, Michael E.; Carruthers, Vern B.; Coppens, Isabelle

2016-01-01

The protozoan parasite Toxoplasma gondii develops within a parasitophorous vacuole (PV) in mammalian cells, where it scavenges cholesterol. When cholesterol is present in excess in its environment, the parasite expulses this lipid into the PV or esterifies it for storage in lipid bodies. Here, we characterized a unique T. gondii homologue of mammalian lecithin:cholesterol acyltransferase (LCAT), a key enzyme that produces cholesteryl esters via transfer of acyl groups from phospholipids to the 3-OH of free cholesterol, leading to the removal of excess cholesterol from tissues. TgLCAT contains a motif characteristic of serine lipases “AHSLG” and the catalytic triad consisting of serine, aspartate, and histidine (SDH) from LCAT enzymes. TgLCAT is secreted by the parasite, but unlike other LCAT enzymes it is cleaved into two proteolytic fragments that share the residues of the catalytic triad and need to be reassembled to reconstitute enzymatic activity. TgLCAT uses phosphatidylcholine as substrate to form lysophosphatidylcholine that has the potential to disrupt membranes. The released fatty acid is transferred to cholesterol, but with a lower transesterification activity than mammalian LCAT. TgLCAT is stored in a subpopulation of dense granule secretory organelles, and following secretion, it localizes to the PV and parasite plasma membrane. LCAT-null parasites have impaired growth in vitro, reduced virulence in animals, and exhibit delays in egress from host cells. Parasites overexpressing LCAT show increased virulence and faster egress. These observations demonstrate that TgLCAT influences the outcome of an infection, presumably by facilitating replication and egress depending on the developmental stage of the parasite. PMID:26694607

Quantitative In Vitro Assessment of Liposome Stability and Drug Transfer Employing Asymmetrical Flow Field-Flow Fractionation (AF4).

PubMed

Holzschuh, Stephan; Kaeß, Kathrin; Fahr, Alfred; Decker, Christiane

2016-04-01

In the present study we introduce an efficient approach for a size-based separation of liposomes from plasma proteins employing AF4. We investigated vesicle stability and release behavior of the strongly lipophilic drug temoporfin from liposomes in human plasma for various incubation times at 37°C. We used the radioactive tracer cholesteryl oleyl ether (COE) or dipalmitoyl-phosphocholine (DPPC) as lipid markers and (14)C-labeled temoporfin. First, both lipid labels were examined for their suitability as liposome markers. Furthermore, the influence of plasma origin on liposome stability and drug transfer was investigated. The effect of membrane fluidity and PEGylation on vesicle stability and drug release characteristics was also analyzed. Surprisingly, we observed an enzymatic transfer of (3)H-COE to lipoproteins due to the cholesterol ester transfer protein (CETP) in human plasma in dependence on membrane rigidity and were able to inhibit this transfer by plasma preincubation with the CETP inhibitor torcetrapib. This effect was not seen when liposomes were incubated in rat plasma. DPPC labels suffered from hydrolysis effects during preparation and/or storage. Fluid liposomes were less stable in human plasma than their PEGylated analogues or a rigid formulation. In contrast, the transfer of the incorporated drug to lipoproteins was higher for the rigid formulations. The observed effects render COE-labels questionable for in vivo studies using CEPT-rich species. Here, choline labelled (14)C-DPPC was found to be the most promising alternative. Bilayer composition has a high influence on stability and drug release of a liposomal formulation in human plasma.

Lipoprotein metabolism in Japanese centenarians: effects of apolipoprotein E polymorphism and nutritional status.

PubMed

Arai, Y; Hirose, N; Nakazawa, S; Yamamura, K; Shimizu, K; Takayama, M; Ebihara, Y; Osono, Y; Homma, S

2001-11-01

To assess the complex interaction of apolipoprotein (apo) E polymorphisms and environmental factors on lipoprotein profile in centenarians. Cross-sectional analysis. Tokyo metropolitan area. Seventy-five centenarians and 73 healthy older volunteers (mean age 63.1 +/- 10.0) living in the Tokyo metropolitan area. Plasma lipids and lipoproteins, cholesteryl ester transfer protein mass, apo E phenotype, body mass index, nutritional indices (serum albumin, prealbumin, transferrin), dietary intake, inflammation markers (C-reactive protein (CRP), interleukin-6 (IL-6)), activities of daily living, and cognitive function. In comparison with older people, the centenarians had low concentrations of total and low-density lipoprotein cholesterol (LDL-C) and a relative predominance of high-density lipoprotein 2 cholesterol. No environmental factor, except the number of apo E epsilon2 alleles, was a significant determinant of LDL-C and apo B, suggesting that the low apo B-containing lipoprotein in centenarians may be attributable to a genetic cause. Centenarians had elevated levels of lipoprotein (a) and decreased high-density lipoprotein cholesterol (HDL-C), which seem to be an unfavorable lipoprotein profile. Lower levels of HDL-C in the centenarians were associated with decreased serum albumin, elevated CRP and IL-6 levels, and cognitive impairment, suggesting that HDL-C could be a sensitive marker for frailty and comorbidity in the oldest old. Low levels of apo B-containing lipoproteins attributable to a genetic cause may be advantageous for longevity. Lipoprotein profiles in centenarians were consistently related to the subjects' nutritional status, inflammation markers, and apo E polymorphisms. The results provide evidence for the importance of maintaining nutritional status in the very old.

Activation of lecithin: cholesterol acyltransferase by human apolipoprotein A-IV.

PubMed

Steinmetz, A; Utermann, G

1985-02-25

Human plasma apoproteins (apo) A-I and A-IV both activate the enzyme lecithin:cholesterol acyltransferase (EC 2.3.1.43). Lecithin:cholesterol acyltransferase activity was measured by the conversion of [4-14C] cholesterol to [4-14C]cholesteryl ester using artificial phospholipid/cholesterol/[4-14C]cholesterol/apoprotein substrates. The substrate was prepared by the addition of apoprotein to a sonicated aqueous dispersion of phospholipid/cholesterol/[4-14C]cholesterol. The activation of lecithin:cholesterol acyltransferase by apo-A-I and -A-IV differed, depending upon the nature of the hydrocarbon chains of the sn-L-alpha-phosphatidylcholine acyl donor. Apo-A-I was a more potent activator than apo-A-IV with egg yolk lecithin, L-alpha-dioleoylphosphatidylcholine, and L-alpha-phosphatidylcholine substituted with one saturated and one unsaturated fatty acid regardless of the substitution position. When L-alpha-phosphatidylcholine esterified with two saturated fatty acids was used as acyl donor, apo-A-IV was more active than apo-A-I in stimulating the lecithin:cholesterol acyltransferase reaction. Complexes of phosphatidylcholines substituted with two saturated fatty acids served as substrate for lecithin:cholesterol acyltransferase even in the absence of any activator protein. Essentially the same results were obtained when substrate complexes (phospholipid-cholesterol-[4-14C]cholesterol-apoprotein) were prepared by a detergent dialysis procedure. Apo-A-IV-L-alpha-dimyristoylphosphatidylcholine complexes thus prepared were shown to be homogeneous particles by column chromatography and density gradient ultracentrifugation. It is concluded that apo-A-IV is able to facilitate the lecithin:cholesterol acyltransferase reaction in vitro.

Effect of apolipoprotein A-I deficiency on lecithin:cholesterol acyltransferase activation in mouse plasma.

PubMed

Parks, J S; Li, H; Gebre, A K; Smith, T L; Maeda, N

1995-02-01

Plasma cholesteryl ester (CE) synthesis by lecithin cholesterol acyltransferase (LCAT) is activated by apolipoprotein (apo)A-I. We studied the effect of plasma apoA-I concentration on LCAT activation, using normal, heterozygous or homozygous apoA-I-deficient mice made by gene targeting. Plasma esterified cholesterol concentrations of mice fed chow diets were ordered (mean +/- SEM): 105 +/- 7 (normal) > 70 +/- 5 (heterozygotes) > 26 +/- 2 (homozygotes) mg/dl. Plasma free cholesterol concentrations were similar among the three genotypes. Endogenous LCAT activity, measured as the decrease in plasma free cholesterol after a 1 h incubation at 37 degrees C, was ordered: 44 +/- 3 (normal) > 21 +/- 2 (heterozygotes) > 5 +/- 1 (homozygotes) nmol CE formed/h per ml plasma. Using a recombinant exogenous substrate consisting of egg yolk phospholipid, [14C]cholesterol, and apoA-I, CE formation of normals and heterozygotes was similar (27.4 +/- 0.6 and 28.8 +/- 1.3 nmol/h per ml plasma, respectively), but was significantly less for homozygotes (19.2 +/- 1.7 nmol/h per ml plasma). However, using a small unilamellar vesicle substrate particle containing phospholipid and [14C]cholesterol, CE formation was ordered: 1.6 +/- 0.1 (normal) = 1.6 +/- 0.1 (heterozygotes) > 0.6 +/- 0.1 (homozygotes) nmol/h per ml plasma; addition of apoA-I to the plasma of homozygous animals restored CE formation to normal levels (1.6 +/- 0.1). CE fatty acid analysis demonstrated that plasma from homozygous mice contained significantly more saturated and monounsaturated and fewer polyunsaturated fatty acids compared to normal and heterozygous mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Managing the residual cardiovascular disease risk associated with HDL-cholesterol and triglycerides in statin-treated patients: a clinical update.

PubMed

Reiner, Z

2013-09-01

Cardiovascular disease (CVD) is a significant cause of death in Europe. In addition to patients with proven CVD, those with type 2 diabetes (T2D) are at a particularly high-risk of CVD and associated mortality. Treatment for dyslipidaemia, a principal risk factor for CVD, remains a healthcare priority; evidence supports the reduction of low-density lipoprotein cholesterol (LDL-C) as the primary objective of dyslipidaemia management. While statins are the treatment of choice for lowering LDL-C in the majority of patients, including those with T2D, many patients retain a high CVD risk despite achieving the recommended LDL-C targets with statins. This 'residual risk' is mainly due to elevated triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) levels. Following statin therapy optimisation additional pharmacotherapy should be considered as part of a multifaceted approach to risk reduction. Fibrates (especially fenofibrate) are the principal agents recommended for add-on therapy to treat elevated TG or low HDL-C levels. Currently, the strongest evidence of benefit is for the addition of fenofibrate to statin treatment in high-risk patients with T2D and dyslipidaemia. An alternative approach is the addition of agents to reduce LDL-C beyond the levels attainable with statin monotherapy. Here, addition of fibrates and niacin to statin therapy is discussed, and novel approaches being developed for HDL-C and TG management, including cholesteryl ester transfer protein inhibitors, Apo A-1 analogues, mipomersen, lomitapide and monoclonal antibodies against PCSK9, are reviewed. Copyright © 2013 Elsevier B.V. All rights reserved.

Plasma lipid fatty acid composition, desaturase activities and insulin sensitivity in Amerindian women.

PubMed

Vessby, B; Ahrén, B; Warensjö, E; Lindgärde, F

2012-03-01

Two Amerindian populations--Shuar women living in the Amazonian rain forest under traditional conditions and urbanized women in a suburb of Lima were studied. The fatty acid composition in plasma lipids and the relationships between fatty acid composition and metabolic variables were studied, as well as in a reference group of Swedish women. Fasting plasma was used for analyses of glucose, insulin, leptin and fatty acid composition. Women in Lima had more body fat, higher fasting insulin and leptin and lower insulin sensitivity than the Shuar women, who had insulin sensitivity similar to Swedish women. Shuar women had very high proportions (mean; SD) of palmitoleic (13.2; 3.9%) and oleic (33.9; 3.7%) acids in the plasma cholesteryl esters with very low levels of linoleic acid (29.1; 6.1 3%), as expected on a low fat, high carbohydrate diet. The estimated activity of delta 9 (SCD-1) desaturase was about twice as high in the Shuar compared with Lima women, suggesting neo lipogenesis, while the delta 5 desaturase activity did not differ. The Lima women, as well as the Swedish, showed strong positive correlations between SCD-1 activity on the one hand and fasting insulin and HOMA index on the other. These associations were absent in the Shuar women. The high SCD-1 activity in the Shuar women may reflect increased lipogenesis in adipose tissue. It also illustrates how a low fat diet rich in non-refined carbohydrates can be linked to a good metabolic situation. Copyright © 2010. Published by Elsevier B.V.

Optimized Li-Ion Electrolytes Containing Fluorinated Ester Co-Solvents

NASA Technical Reports Server (NTRS)

Prakash, G. K. Surya; Smart, Marshall; Smith, Kiah; Bugga, Ratnakumar

2010-01-01

A number of experimental lithium-ion cells, consisting of MCMB (meso-carbon microbeads) carbon anodes and LiNi(0.8)Co(0.2)O2 cathodes, have been fabricated with increased safety and expanded capability. These cells serve to verify and demonstrate the reversibility, low-temperature performance, and electrochemical aspects of each electrode as determined from a number of electrochemical characterization techniques. A number of Li-ion electrolytes possessing fluorinated ester co-solvents, namely trifluoroethyl butyrate (TFEB) and trifluoroethyl propionate (TFEP), were demonstrated to deliver good performance over a wide temperature range in experimental lithium-ion cells. The general approach taken in the development of these electrolyte formulations is to optimize the type and composition of the co-solvents in ternary and quaternary solutions, focusing upon adequate stability [i.e., EC (ethylene carbonate) content needed for anode passivation, and EMC (ethyl methyl carbonate) content needed for lowering the viscosity and widening the temperature range, while still providing good stability], enhancing the inherent safety characteristics (incorporation of fluorinated esters), and widening the temperature range of operation (the use of both fluorinated and non-fluorinated esters). Further - more, the use of electrolyte additives, such as VC (vinylene carbonate) [solid electrolyte interface (SEI) promoter] and DMAc (thermal stabilizing additive), provide enhanced high-temperature life characteristics. Multi-component electrolyte formulations enhance performance over a temperature range of -60 to +60 C. With the need for more safety with the use of these batteries, flammability was a consideration. One of the solvents investigated, TFEB, had the best performance with improved low-temperature capability and high-temperature resilience. This work optimized the use of TFEB as a co-solvent by developing the multi-component electrolytes, which also contain non-halogenated esters, film forming additives, thermal stabilizing additives, and flame retardant additives. Further optimization of these electrolyte formulations is anticipated to yield improved performance. It is also anticipated that much improved performance will be demonstrated once these electrolyte solutions are incorporated into hermetically sealed, large capacity prototype cells, especially if effort is devoted to ensure that all electrolyte components are highly pure.

Self-sensing of elastic strain, matrix yielding and plasticity in multiwall carbon nanotube/vinyl ester composites

NASA Astrophysics Data System (ADS)

Ku-Herrera, J. J.; Avilés, F.; Seidel, G. D.

2013-08-01

The piezoresistive response of multiwalled carbon nanotube/vinyl ester composites containing 0.3, 0.5 and 1% w/w carbon nanotubes (CNTs) loaded in tension and compression is investigated. The change in electrical resistance (ΔR) under tension loading was positive and showed a linear relationship with the applied strain up to failure, with slightly increased sensitivity for decreased CNT content. In compression, a nonlinear and non-monotonic piezoresistive behavior was observed, with ΔR initially decreasing in the elastic regime, leveling off at the onset of yielding and increasing after matrix yielding. The piezoresistive response of the composite is more sensitive to the CNT content for compression than for tension, and the calculated gage factors are higher in the compressive plastic regime. The results show that the piezoresistive signal is dependent on the CNT concentration, loading type and material elastoplastic behavior, and that recording ΔR during mechanical loading can allow self-identification of the elastic and plastic regimes of the composite.

Spatiotemporal distribution and risk assessment of organophosphate esters in sediment from Taihu Lake, China.

PubMed

Chen, Meihong; Liu, Yanhua; Guo, Ruixin; Xu, Huaizhou; Song, Ninghui; Han, Zhihua; Chen, Nannan; Zhang, Shenghu; Chen, Jianqiu

2018-05-01

The occurrence and spatiotemporal distribution of 12 organophosphate esters (OPEs) were investigated in the sediments collected from Taihu Lake. Compared to the same lake in 2012 (3.4-14 ng/g dw), the concentrations of ∑12 OPEs in sediments ranged from 10.76 to 335.37 ng/g dw and from 8.06 to 425.39 ng/g dw in 2015 and in 2016, respectively, indicating that the OPEs levels in Taihu Lake have aggravated, recently. TEHP was the most abundant compound of the OPEs, which suggested that TEHP was the most widely used around Taihu Lake recently. The positive correlations between some of individual OPEs and the principal components analysis suggested the same potential sources for them. The strong positive correlation between ∑BPs and TOC content indicated that TOC content was one of the factors affected the distribution of ∑OPEs in the sediment. Risk quotient (RQ) for OPEs showed no high eco-toxicity risk in sediment for aquatic organisms.

Incorporating silica into cyanate ester-based network by sol-gel method: Structure and properties of subnano- and nanocomposites

NASA Astrophysics Data System (ADS)

Bershtein, V.; Fainleib, A.; Kirilenko, D.; Yakushev, P.; Gusakova, K.; Lavrenyuk, N.; Ryzhov, V.

2016-05-01

A series of Cyanate Ester Resins (CER)-based composites containing 0.01-10 wt. % silica, introduced by sol-gel method, was synthesized using tetraethoxysilane (TEOS) and γ-aminopropyltrimethoxysilane (APTMS), and their nanostructure and properties were characterized by means of STEM/EDXS, Far-IR spectroscopy, DMA and DSC methods. It was revealed that the most substantial positive impact on CER dynamics, thermal and mechanical properties is attained at ultra-low silica contents, e.g., at 0.1 wt. % silica where Tg and modulus increase, respectively, by 50° and 60%. In this case, silica nanoclusters are absent in the composite, and only chemically incorporated silica junctions of subnanometric size in the densely-crosslinked CER network could be implied. These composites can be designated as "polymer subnanocomposites". Contrarily, formation of silica nanoclusters and especially their aggregates of hundreds nanometers in size at silica contents of 2-10 wt. % led to the distinct negative impact on the matrix properties.

pH-triggered chitosan nanogels via an ortho ester-based linkage for efficient chemotherapy.

PubMed

Yang, Guanqing; Wang, Xin; Fu, Shengxiang; Tang, Rupei; Wang, Jun

2017-09-15

We report on new types of chitosan-based nanogels via an ortho ester-based linkage, used as drug carriers for efficient chemotherapy. First, we synthesized a novel diacrylamide containing ortho ester (OEAM) as an acid-labile cross-linker. Subsequently, methacrylated succinyl-chitosan (MASCS) was prepared and polymerized with OEAM at different molar ratios to give a series of pH-triggered MASCS nanogels. Doxorubicin (DOX) as a model anticancer drug was loaded into MASCS nanogels with a loading content of 16.5%. As expected, with the incorporation of ortho ester linkages, these nanogels showed pH-triggered degradation and drug release at acidic pH values. In vitro cellular uptake shows that the DOX-loaded nanogels could be preferentially internalized by two-dimensional (2D) cells and three-dimensional (3D) multicellular spheroids (MCs), resulting in higher inhibition of the proliferation of tumor cells. In vivo biodistribution and anti-tumor effect were determined in H22 tumor-bearing mice, and the results demonstrate that the acid-labile MASCS nanogels can significantly prolong the blood circulation time of DOX and improve the accumulation in tumor areas, leading to higher therapeutic efficacy. We designed new pH-triggered chitosan nanogels via an ortho ester-based cross-linker for efficient drug-loading and chemotherapy. These drug-loaded nanogels exhibit excellent pH-triggered drug release behavior due to the degradation of ortho ester linkages in mildly acidic environments. In vitro and in vivo results demonstrate that the nanogels could be efficiently internalized by 2D cells and 3D-MCs, improve drug concentration in solid tumors, and lead to higher therapeutic efficacy. To the best of our knowledge, this is the first report on using an ortho ester-based cross-linker to prepare pH-triggered chitosan nanogels as tumor carriers, which may provide a potential route for improved safety and to increase the therapeutic efficacy of anticancer therapy. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Experimental assessment of toxic phytochemicals in Jatropha curcas: oil, cake, bio-diesel and glycerol.

PubMed

Pradhan, Subhalaxmi; Naik, S N; Khan, M Ashhar I; Sahoo, P K

2012-02-01

Jatropha curcas seed is a rich source of oil; however, it can not be utilised for nutritional purposes due to presence of toxic and anti-nutritive compounds. The main objective of the present study was to quantify the toxic phytochemicals present in Indian J. curcas (oil, cake, bio-diesel and glycerol). The amount of phorbol esters is greater in solvent extracted oil (2.8 g kg⁻¹) than in expeller oil (2.1 g kg⁻¹). Liquid chromatography-mass spectroscopy analysis of the purified compound from an active extract of oil confirmed the presence of phorbol esters. Similarly, the phorbol esters content is greater in solvent extracted cake (1.1 g kg⁻¹) than in cake after being expelled (0.8 g kg⁻¹). The phytate and trypsin inhibitory activity of the cake was found to be 98 g kg⁻¹ and 8347 TIU g⁻¹ of cake, respectively. Identification of curcin was achieved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the concentration of curcin was 0.95 g L⁻¹ of crude concentrate obtained from cake. Higher amounts of phorbol esters are present in oil than cake but bio-diesel and glycerol are free of phorbol esters. The other anti-nutritional components such as trypsin inhibitors, phytates and curcin are present in cake, so the cake should be detoxified before being used for animal feed. Copyright © 2011 Society of Chemical Industry.

Influence of fatty acid methyl esters from hydroxylated vegetable oils on diesel fuel lubricity.

PubMed

Goodrum, John W; Geller, Daniel P

2005-05-01

Current and future regulations on the sulfur content of diesel fuel have led to a decrease in lubricity of these fuels. This decreased lubricity poses a significant problem as it may lead to wear and damage of diesel engines, primarily fuel injection systems. Vegetable oil based diesel fuel substitutes (biodiesel) have been shown to be clean and effective and may increase overall lubricity when added to diesel fuel at nominally low levels. Previous studies on castor oil suggest that its uniquely high level of the hydroxy fatty acid ricinoleic acid may impart increased lubricity to the oil and its derivatives as compared to other vegetable oils. Likewise, the developing oilseed Lesquerella may also increase diesel lubricity through its unique hydroxy fatty acid composition. This study examines the effect of castor and Lesquerella oil esters on the lubricity of diesel fuel using the High-Frequency Reciprocating Rig (HFRR) test and compares these results to those for the commercial vegetable oil derivatives soybean and rapeseed methyl esters.

Synthesis of Degradable Poly(vinyl alcohol) by Radical Ring-Opening Copolymerization and Ice Recrystallization Inhibition Activity.

PubMed

Hedir, Guillaume; Stubbs, Christopher; Aston, Phillip; Dove, Andrew P; Gibson, Matthew I

2017-12-19

Poly(vinyl alcohol) (PVA) is the most active synthetic mimic of antifreeze proteins and has extremely high ice recrystallization inhibition (IRI) activity. Addition of PVA to cellular cryopreservation solutions increases the number of recovered viable cells due to its potent IRI, but it is intrinsically nondegradable in vivo . Here we report the synthesis, characterization, and IRI activity of PVA containing degradable ester linkages. Vinyl chloroacetate (VClAc) was copolymerized with 2-methylene-1,3-dioxepane (MDO) which undergoes radical ring-opening polymerization to install main-chain ester units. The use of the chloroacetate monomer enabled selective deacetylation with retention of esters within the polymer backbone. Quantitative IRI assays revealed that the MDO content had to be finely tuned to retain IRI activity, with higher loadings (24 mol %) resulting in complete loss of IRI activity. These degradable materials will help translate PVA, which is nontoxic and biocompatible, into a range of biomedical applications.

Analysis of the physicochemical properties of post-manufacturing waste derived from production of methyl esters from rapeseed oil

NASA Astrophysics Data System (ADS)

Kachel-Jakubowska, Magdalena; Matwijczuk, Arkadiusz; Gagoś, Mariusz

2017-04-01

The technology of transesterification of biodiesel obtained from many agricultural products, which are often referred to as renewable resources, yields substantial amounts of by-products. They exhibit various properties that prompt scientific research into potential application thereof. Various spectroscopic methods, e.g. Fourier transform infrared spectroscopy, are being increasingly used in the research. In this paper, we present the results of Fourier transform infrared spectroscopy spectroscopy analyses of technical glycerine, distilled glycerine, and matter organic non glycerol, i.e. by-products of biodiesel production. To facilitate the spectroscopic analysis, a number of parameters were determined for all the materials, e.g. the calorific value, water content, sulphated ash content, methanol content, acidity, as well as the contents of esters, heavy metals, aldehydes, nitrogen, and phosphorus. The results indicate that the analysed products are characterised by a comparable calorific value in the range from 11.35 to 16.05 MJ kg-1 in the case of matter organic non glycerol and technical glycerine. Observation of changes in the position of selected peaks in the range of 3700-650 cm-1 in the Fourier transform infrared spectroscopy method facilitates determination of the level of degradation of the analysed material. Changes in the wavelength ranges can be used for monitoring the formation of secondary oxidation products containing carbonyl groups.

Entropy Calculations for a Supercooled Liquid Crystalline Blue Phase

ERIC Educational Resources Information Center

Singh, U.

2007-01-01

We observed, using polarized light microscopy, the supercooling of the blue phase (BPI) of cholesteryl proprionate and measured the corresponding liquid crystalline phase transition temperatures. From these temperatures and additional published data we have provided, for the benefit of undergraduate physics students, a nontraditional example…

Polyplex micelle installing intracellular self-processing functionalities without free catiomers for safe and efficient systemic gene therapy through tumor vasculature targeting.

PubMed

Chen, Qixian; Osada, Kensuke; Ge, Zhishen; Uchida, Satoshi; Tockary, Theofilus A; Dirisala, Anjaneyulu; Matsui, Akitsugu; Toh, Kazuko; Takeda, Kaori M; Liu, Xueying; Nomoto, Takahiro; Ishii, Tekihiko; Oba, Makoto; Matsumoto, Yu; Kataoka, Kazunori

2017-01-01

Both efficiency and safety profiles are crucial for promotion of gene delivery systems towards practical applications. A promising template system was previously developed based on block catiomer of poly(ethylene glycol) (PEG)-b-poly{N'-[N-(2-aminoethyl)-2-aminoehtyl]aspartamide}-cholesteryl [PEG-PAsp(DET)-cholesteryl] with strategies of ligand conjugation at the α-terminus for specific affinity to the targeted cells and cholesteryl conjugation at the ω-terminus for structural stabilization to obtain systemic retention. Aiming for advocating this formulation towards practical applications, in the current study, the binding profile of this polymer to plasmid DNA (pDNA) was carefully studied to address an issue of toxicity origin. Quantification of free polymer composition confirmed that the toxicity mainly results from unbound polymer and polyplex micelle itself has negligible toxicity. This evaluation allowed for identifying an optimal condition to prepare safe polyplex micelles for systemic application that possess maximal polymer-binding but exclude free polymers. The identified polyplex micelles then faced a drawback of limited transfection efficiency due to the absence of free polymer, which is an acknowledged tendency found in various synthetic gene carriers. Thus, series of functional components was strategically compiled to improve the transfection efficiency such as attachment of cyclic (Arg-Gly-Asp) (cRGD) peptide as a ligand onto the polyplex micelles to facilitate cellular uptake, use of endosome membrane disruptive catiomer of PAsp(DET) for facilitating endosome escape along with use of the conjugated cholesteryl group to amplify the effect of PAsp(DET) on membrane disruption, so as to obtain efficient transfection. The mechanistic investigation respecting the appreciated pH dependent protonation behavior of PAsp(DET) permitted to depict an intriguing scenario how the block catiomers manage to escape from the endosome entrapment in response to the pH gradient. Subsequent systemic application to the pancreatic tumor demonstrated a capability of vascular targeting mediated by the cRGD ligand, which was directly confirmed based on in situ confocal laser scanning microscopy observation. Encouraging this result, the vascular targeting to transfect a secretable anti-angiogenic gene was attempted to treat the intractable pancreatic tumor with anticipation that the strategy could circumvent the intrinsic physiological barriers derived from hypovascular and fibrotic characters. The obtained therapeutic efficiency demonstrates promising utilities of the proposed formulation as a safe systemic gene delivery carrier in practical use. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Inhibition of Linseed Oil Autooxidation by Essential Oils and Extracts from Spice Plants].

PubMed

Misharina, T A; Alinkina, E S; Terenina, M B; Krikunova, N I; Kiseleva, V I; Medvedeva, I B; Semenova, M G

2015-01-01

Clove bud essential oil, extracts from ginger, pimento and black pepper, or ascorbyl palmytate were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids in linseed oil. Different methods were used to estimate antioxidant efficiency. These methods are based on the following parameters: peroxide values; peroxide concentration; content of degradation products of unsaturated fatty acid peroxides, which acted with thiobarbituric acid; diene conjugate content; the content of volatile compounds that formed as products of unsaturated fatty acid peroxide degradation; and the composition of methyl esters of fatty acids in samples of oxidized linseed oil.

Influence of different surfactants on the physicochemical properties of elastic liposomes.

PubMed

Barbosa, R M; Severino, P; Preté, P S C; Santana, M H A

2017-05-01

Elastic liposomes are capable to improve drug transport through the skin by acting as penetration enhancers due to the high fluidity and elasticity of the liposome membranes. Therefore, elastic liposomes were prepared and characterized to facilitate the transdermal transport of bioactive molecules. Liposomes consisted of dimyristoylphosphatidylcholine (DMPC) as the structural component, with different surfactants derived from lauric acid as elastic components: C 12 E 5 (polyoxyethylene-5-lauryl ether), PEG4L (polyethyleneglycol-4-lauryl ester), PEG4DL (polyethylene glycol-4-dilauryl ester), PEG8L (polyethylene glycol-8-lauryl ester) and PEG8DL (polyethylene glycol-8-dilauryl ester). The elastic liposomes were characterized in terms of their phospholipid content, mean diameter, size distribution, elasticity and stability during storage, as well as their ability to incorporate surfactant and permeate through 50 nm pore size membranes. The results showed that the phospholipid phase transition temperature, the fluidity of the lipid bilayer resulting from incorporation of the surfactant and the preservation of particle integrity were factors determining the performance of the elastic liposomes in permeating through nanoporous membranes. The best results were obtained using DMPC combined with the surfactants PEG8L or PEG8DL. The findings demonstrate the potential of using elastic liposomes for transdermal administration of drugs.

Impact of lignin polymer backbone esters on ionic liquid pretreatment of poplar

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

Kim, Kwang Ho; Dutta, Tanmoy; Ralph, John

Biomass pretreatment remains an essential step in lignocellulosic biofuel production, largely to facilitate the efficient removal of lignin and increase enzyme accessibility to the polysaccharides. In recent years, there have been significant efforts in planta to reduce lignin content or modify its composition to overcome the inherent recalcitrance that it imposes on lignocellulosic biomass during processing. Here, transgenic poplar lines in which monolignol ferulate conjugates were synthesized during cell wall development to introduce, during lignification, readily cleavable ester linkages into the lignin polymer backbone (i.e., "zip lignin"), along with wild-type (WT) controls, were pretreated with different ionic liquids (ILs). Themore » strategic introduction of ester bonds into the lignin backbone resulted in increased pretreatment efficiency and released more carbohydrates with lower energy input. After pretreatment with any of three different ILs, and after limited saccharification, the transgenic poplars, especially those with relatively higher amounts of incorporated monolignol ferulate conjugates, yielded up to 23% higher sugar levels compared to WT plants. Our findings clearly demonstrate that the introduction of ester linkages into the lignin polymer backbone decreases biomass recalcitrance in poplar has the potential to reduce the energy and/or amount of IL required for effective pretreatment, and could enable the development of an economically viable and sustainable biorefinery process.« less

Impact of lignin polymer backbone esters on ionic liquid pretreatment of poplar

DOE PAGES

Kim, Kwang Ho; Dutta, Tanmoy; Ralph, John; ...

2017-04-20

Biomass pretreatment remains an essential step in lignocellulosic biofuel production, largely to facilitate the efficient removal of lignin and increase enzyme accessibility to the polysaccharides. In recent years, there have been significant efforts in planta to reduce lignin content or modify its composition to overcome the inherent recalcitrance that it imposes on lignocellulosic biomass during processing. Here, transgenic poplar lines in which monolignol ferulate conjugates were synthesized during cell wall development to introduce, during lignification, readily cleavable ester linkages into the lignin polymer backbone (i.e., "zip lignin"), along with wild-type (WT) controls, were pretreated with different ionic liquids (ILs). Themore » strategic introduction of ester bonds into the lignin backbone resulted in increased pretreatment efficiency and released more carbohydrates with lower energy input. After pretreatment with any of three different ILs, and after limited saccharification, the transgenic poplars, especially those with relatively higher amounts of incorporated monolignol ferulate conjugates, yielded up to 23% higher sugar levels compared to WT plants. Our findings clearly demonstrate that the introduction of ester linkages into the lignin polymer backbone decreases biomass recalcitrance in poplar has the potential to reduce the energy and/or amount of IL required for effective pretreatment, and could enable the development of an economically viable and sustainable biorefinery process.« less

Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

PubMed

da Rocha-Filho, Pedro Alves; Maruno, Mônica; Ferrari, Márcio; Topan, José Fernando

2016-06-09

The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

Biotransformation Strategy To Reduce Allergens in Propolis

PubMed Central

Gardana, Claudio; Barbieri, Andrea; Simonetti, Paolo

2012-01-01

Propolis (bee glue) is a resinous, sticky, dark-colored material produced by honeybees. Propolis today, due to its medicinal properties, is increasingly popular and is extensively used in food, beverages, and cosmetic products. Besides its numerous positive properties, propolis may also have adverse effects, such as, principally, allergic eczematous contact dermatitis in apiarists and in consumers with an allergic predisposition. In this study, we found appropriate conditions for removing caffeate esters, which are the main allergenic components, from raw propolis. The proposed method consists of the resuspension of propolis in a food grade solvent, followed by a biotransformation based on the cinnamoyl esterase activity of Lactobacillus helveticus. We showed that the reduction of caffeate esters by L. helveticus did not affect the content of flavonoids, which are the main bioactive molecules of propolis. Furthermore, we verified that the biotransformation of propolis did not cause a loss of antimicrobial activity. Finally, we demonstrated that the ability of L. helveticus to hydrolyze caffeate esters in propolis is strain specific. In conclusion, the proposed strategy is simple, employs food grade materials, and is effective in selectively removing allergenic molecules without affecting the bioactive fraction of propolis. This is the first study demonstrating that the allergenic caffeate esters of propolis can be eliminated by means of a bacterial biotransformation procedure. PMID:22522681

A Comparative Study of Dilute acid and Ionic Liquid Pretreatment of Biomass and Model Lignocellulosics

USDA-ARS?s Scientific Manuscript database

Lignocellulosic biomass has the great potential to serve as the low cost and abundant feedstock for bioconversion into fermentable sugars, which can be further utilized for biofuel production. However, high lignin content, crystalline cellulose structure and the presence of ester linkages between l...

New 5-O-caffeoylquinic acid derivatives in fruit of the wild eggplant relative Solanum viarum

USDA-ARS?s Scientific Manuscript database

Fruit of cultivated eggplant (Solanum melongena) and several wild relatives (S. aethiopicum, S. macrocarpon, S. anguivi, and S. incanum) have a high content of hydroxycinnamic acid (HCA) conjugates. Typically, caffeoylquinic acid esters predominate, and in particular chlorogenic acid [5-O-(E)-caffeo...

Assessment of chemical and sensory quality of sugarcane alcoholic fermented beverage.

PubMed

Resende Oliveira, Érica; Caliari, Márcio; Soares Soares Júnior, Manoel; Ribeiro Oliveira, Aryane; Cristina Marques Duarte, Renata; Valério de Barros Vilas Boas, Eduardo

2018-01-01

This study aimed to verify the technological feasibility, chemical quality and sensory acceptance of alcoholic fermented beverage obtained from sugarcane juice. A completely randomized design was applied. Sugar and alcohol content, phenolic (HPLC-MS) and volatile (GS-MS) compounds, pH, density, dry matter and acidity of the fermented beverage of sugarcane were quantified, as well as the acceptance of the product was carried out. The complete fermentation of sugarcane lasted 7 days, and it was obtained an alcohol content of 8.0% v/v. Titrable acidity of the beverage was of 67.31 meq L -1 , pH 4.03, soluble solids of 5 °Brix, reducing sugar of 0.07 g glucose 100 g -1 , density of 0.991 g cm -3 , reduced dry matter of 14.15 g L -1 , sulfates lower than 0.7 g K 2 SO 4  L -1 . Various phenolic compounds, among which, gallic acid (10.97%), catechin (1.73%), chlorogenic acid (3.52%), caffeic acid (1.49%), vanillic acid (0.28%), p -coumaric acid (0.24%), ferulic acid (6.63%), m -coumaric acid (0.36%), and o -coumaric acid (0.04%). Amongst aromatic compounds, were found mainly esters with fruity aromas (ethyl ester hexanoic acid and ethyl ester octanoic acid). The sugarcane juice can be commercialized as an alternative wine, as it presented adequate features to an alcoholic fermented beverage and was sensory accepted by consumers.

Infrared spectra in monitoring biochemical parameters of human blood

NASA Astrophysics Data System (ADS)

Prabhakar, S.; Jain, N.; Singh, R. A.

2012-05-01

Infrared spectroscopy is gaining recognition as a promising method. The infrared spectra of selected regions (2000-400cm-1) of blood tissue samples are reported. Present study related to the role of spectral peak fitting in the study of human blood and quantitative interpretations of infrared spectra based on chemometrics. The spectral variations are interpreted in terms of the biochemical and pathological processes involved. The mean RNA/DNA ratio of fitted intensities and analytical area as calculated from the transmittance peaks at 1121cm-1/1020cm-1 is found to be 0.911A.U and 2.00A.U. respectively. The ratio of 1659cm-1/1544cm-1 (amide-I/amide-II) bands is found to shed light on the change in the DNA content. The ratio of amide-I/amide-II is almost unity (≈1.054) for blood spectra. The deviation from unity is an indication of DNA absorption from the RBC cells. The total phosphate content has found to be 25.09A.U. The level for glycogen/phosphate ratio (areas under peaks 1030cm-1/1082cm-1) is found to be 0.286A.U. The ratio of unsaturated and saturated carbonyl compounds (C=O) in blood samples is in form of esters and the analytical areas under the spectral peaks at 1740cm-1 and 1731cm-1 for unsaturated esters and saturated esters respectively found to be 0.618A.U.

Crystallization of steroids in gels

NASA Astrophysics Data System (ADS)

Kalkura, S. Narayana; Devanarayanan, S.

1991-03-01

The crystal growth and characterization of certain steriods, viz., cholesterol, cholesteryl acetate, β-sitosterol, progesterone and testosterone, in a silica gel medium is discussed. The present study shows that the single test tube diffusion method can be used to grow crystals of steroids in a silica gel medium by the reduction of steroid solubility.

Simultaneous estimation of phenolic acids in sea buckthorn (Hippophaë rhamnoides) using RP-HPLC with DAD.

PubMed

Arimboor, Ranjith; Kumar, K Sarin; Arumughan, C

2008-05-12

A RP-HPLC-DAD method was developed and validated for the simultaneous analysis of nine phenolic acids including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, salicylic acid, p-coumaric acid, cinnamic acid, caffiec acid and ferulic acid in sea buckthorn (SB) (Hippophaë rhamnoides) berries and leaves. The method was validated in terms of linearity, LOD, precision, accuracy and recovery and found to be satisfactory. Phenolic acid derivatives in anatomical parts of SB berries and leaves were separated into free phenolic acids, phenolic acids bound as esters and phenolic acids bound as glycosides and profiled in HPLC. Berry pulp contained a total of 1068 mg/kg phenolic acids, of which 58.8% was derived from phenolic glycosides. Free phenolic acids and phenolic acid esters constituted 20.0% and 21.2%, respectively, of total phenolic acids in SB berry pulp. The total phenolic acid content in seed kernel (5741 mg/kg) was higher than that in berry pulp and seed coat (Table 2). Phenolic acids liberated from soluble esters constituted the major fraction of phenolic acids (57.3% of total phenolic acids) in seed kernel. 8.4% and 34.3% of total phenolic acids in seed kernel were, respectively contributed by free and phenolic acids liberated from glycosidic bonds. The total soluble phenolic acids content in seed coat (448 mg/kg) was lower than that in seed kernel and pulp (Table 2). Proportion of free phenolic acids in total phenolic acids in seed coat was higher than that in seed kernel and pulp. Phenolic acids bound as esters and glycosides, respectively contributed 49.1% and 20.3% of total phenolic acids in seed coat. The major fraction (approximately 70%) of phenolic acids in SB berries was found to be concentrated in the seeds. Gallic acid was the predominant phenolic acid both in free and bound forms in SB berry parts and leaves.

Molecular Structures and Sorption Mechanisms of Biochars as Heterogeneous Carbon Materials

NASA Astrophysics Data System (ADS)

Chen, Baoliang; Chen, Zaiming; Xiao, Xin; Fang, Qile

2015-04-01

Surface functional groups such as carboxyl play a vital role in the environmental applications of biochar as a soil amendment. However, the quantification of oxygen-containing groups on a biochar surface still lacks systematical investigation. An integrated method combining chemical and spectroscopic techniques was established to quantitatively identify the chemical states, dissociation constants (pKa), and contents of oxygen-containing groups on dairy manure-derived biochars prepared at 100-700 °C. The dissociation pH of carboxyl groups on the biochar surface covered a wide range of pH values (pH 2-11), due to the varied structural micro-environments and chemical states. For low temperature biochars (≤350 °C), carboxyl existed not only as hydrogen-bonded carboxyl and unbonded carboxyl groups but also formed esters at the surface of biochars. The esters consumed OH‒ via saponification in the alkaline pH region and enhanced the dissolution of organic matter from biochars. For high temperature biochars (≥500 °C), esters came from carboxyl were almost eliminated via carbonization (ester pyrolysis), while lactones were developed. The surface density of carboxyl groups on biochars decreased sharply with the increase of the biochar-producing temperature, but the total contents of the surface carboxyls for different biochars were comparable (with a difference < 3-fold) as a result of the expanded surface area at high pyrolytic temperatures. Understanding the wide pKa ranges and the abundant contents of carboxyl groups on biochars is a prerequisite to recognition of the multi-functional applications and biogeochemical cycling of biochars. A schematic diagram for the dissociation of acid/base groups on biochar surfaces and their related functions was depicted. The protonated biochars favor inorganic anion adsorption and ionizable organic chemical sorption, while the deprotonated biochars favor cationic nutrient retention, heavy metal immobilization, and the release of dissolved materials. For low temperature biochars (i.e., DM100, DM250 and DM350), the acid/base group dissociation directly controls the pH buffering properties of biochars. The resulting surface charges regulate biochars in nutrient retention, sorption/immobilization of hazardous pollutants and biochar particle dispersing properties. Meanwhile, dissociation of acid/base groups affects carbon and silica biogeochemical cycling by regulating the release of organic matter from the cleavage of esters and dissolution of the Si-containing minerals. For high temperature biochars (i.e., DM500 and DM700), the effect of acid/base dissociation on organic matter dissolution is eliminated, but other functions are similar. CGs are the major acid/base groups on biochar surfaces. In field applications, such abundant CGs are worthy of concern in terms of multiple functions of biochars, such as soil pH adjustment, soil nutrient retention, and toxic metals immobilization.

Synthesis of fatty acid methyl ester from the transesterification of high- and low-acid-content crude palm oil (Elaeis guineensis) and karanj oil (Pongamia pinnata) over a calcium-lanthanum-aluminum mixed-oxides catalyst.

PubMed

Syamsuddin, Y; Murat, M N; Hameed, B H

2016-08-01

The synthesis of fatty acid methyl ester (FAME) from the high- and low-acid-content feedstock of crude palm oil (CPO) and karanj oil (KO) was conducted over CaO-La2O3-Al2O3 mixed-oxide catalyst. Various reaction parameters were investigated using a batch reactor to identify the best reaction condition that results in the highest FAME yield for each type of oil. The transesterification of CPO resulted in a 97.81% FAME yield with the process conditions of 170°C reaction temperature, 15:1 DMC-to-CPO molar ratio, 180min reaction time, and 10wt.% catalyst loading. The transesterification of KO resulted in a 96.77% FAME yield with the conditions of 150°C reaction temperature, 9:1 DMC-to-KO molar ratio, 180min reaction time, and 5wt.% catalyst loading. The properties of both products met the ASTM D6751 and EN 14214 standard requirements. The above results showed that the CaO-La2O3-Al2O3 mixed-oxide catalyst was suitable for high- and low-acid-content vegetable oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct quantification of fatty acids in wet microalgal and yeast biomass via a rapid in situ fatty acid methyl ester derivatization approach.

PubMed

Dong, Tao; Yu, Liang; Gao, Difeng; Yu, Xiaochen; Miao, Chao; Zheng, Yubin; Lian, Jieni; Li, Tingting; Chen, Shulin

2015-12-01

Accurate determination of fatty acid contents is routinely required in microalgal and yeast biofuel studies. A method of rapid in situ fatty acid methyl ester (FAME) derivatization directly from wet fresh microalgal and yeast biomass was developed in this study. This method does not require prior solvent extraction or dehydration. FAMEs were prepared with a sequential alkaline hydrolysis (15 min at 85 °C) and acidic esterification (15 min at 85 °C) process. The resulting FAMEs were extracted into n-hexane and analyzed using gas chromatography. The effects of each processing parameter (temperature, reaction time, and water content) upon the lipids quantification in the alkaline hydrolysis step were evaluated with a full factorial design. This method could tolerate water content up to 20% (v/v) in total reaction volume, which equaled up to 1.2 mL of water in biomass slurry (with 0.05-25 mg of fatty acid). There were no significant differences in FAME quantification (p>0.05) between the standard AOAC 991.39 method and the proposed wet in situ FAME preparation method. This fatty acid quantification method is applicable to fresh wet biomass of a wide range of microalgae and yeast species.

Novel utilization of waste marine sponge (Demospongiae) as a catalyst in ultrasound-assisted transesterification of waste cooking oil.

PubMed

Hindryawati, Noor; Maniam, Gaanty Pragas

2015-01-01

This study demonstrates the potential of Na-silica waste sponge as a source of low cost catalyst in the transesterification of waste cooking oil aided by ultrasound. In this work an environmentally friendly and efficient transesterification process using Na-loaded SiO2 from waste sponge skeletons as a solid catalyst is presented. The results showed that the methyl esters content of 98.4±0.4wt.% was obtainable in less than an hour (h) of reaction time at 55°C. Optimization of reaction parameters revealed that MeOH:oil, 9:1; catalyst, 3wt.% and reaction duration of 30min as optimum reaction conditions. The catalyst is able to tolerant free fatty acid and moisture content up to 6% and 8%, respectively. In addition, the catalyst can be reused for seven cycles while maintaining the methyl esters content at 86.3%. Ultrasound undoubtedly assisted in achieving this remarkable result in less than 1h reaction time. For the kinetics study at 50-60°C, a pseudo first order model was proposed, and the activation energy of the reaction is determined as 33.45kJ/mol using Arrhenius equation. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-hexyl ester on Peronophythora litchii infection, quality and physiology of postharvest litchi fruits.

PubMed

Liu, Hai; Jing, Guoxing; Jiang, Yueming; Luo, Fuying; Li, Zaifeng

2017-01-01

Litchi ( Litchi chinensis Sonn.) is a subtropical fruit with attractive characteristic of white to creamy semitranslucent flesh and red color in pericap, but it was easily subjected to the infection of Peronophythora litchii and lost its market values. Experiments were conducted to understand the effect of [Carbamic acid, (1,2,3-thiadiazole-4-ylcarbonyl)-hexyl ester, CTE] on the growth of P. litchi and quality properties in litchi fruits during postharvest storage. In vitro experiments, CTE with minimum inhibitory concentration (MIC, 5 mg/L) and minimum fungicidal concentration (MFC, 10 mg/L) were against the growth of P. litchi for 2 and 4 days, respectively, and SEM results showed that hyphae of P. litchii shrank, distorted and collapsed after CTE treatment. In vivo experiments, CTE treatment inhibited the increase of disease incidence, browning index, weight loss and PPO activity in non- P. litchii -inoculated fruits, meanwhile the treatment markedly inhibited the decrease of color characteristic (a*, b* and L*), anthocyanin content, phenolic contents, Vc content and POD activity, but TSS content was not significantly influenced during storage. In P. litchii -inoculated fruits, all these above mentioned parameters in CTE treated fruits were significantly higher than that in control fruits, but anthocyanin content, Vc, TSS and TA content did not have consistent differences between control and CTE treated fruits at the end of storage. CTE treatment reduced the disease incidence and browning index of litchi fruits, maintained the fruits quality and, thus, it could be an effective postharvest handling to extend the shelf life of litchi fruits during storage.

Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults

PubMed Central

Chambers, Edward S; Viardot, Alexander; Psichas, Arianna; Morrison, Douglas J; Murphy, Kevin G; Zac-Varghese, Sagen E K; MacDougall, Kenneth; Preston, Tom; Tedford, Catriona; Finlayson, Graham S; Blundell, John E; Bell, Jimmy D; Thomas, E Louise; Mt-Isa, Shahrul; Ashby, Deborah; Gibson, Glen R; Kolida, Sofia; Dhillo, Waljit S; Bloom, Stephen R; Morley, Wayne; Clegg, Stuart; Frost, Gary

2015-01-01

Objective The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. Design To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. Results Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. Conclusions These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. Trial registration number NCT00750438. PMID:25500202

Development of a quantitative GC-FID method for the determination of sucrose mono- and diesters in foods.

PubMed

Cucu, Tatiana; De Meulenaer, Bruno

2015-01-01

Sucrose esters (E 473) are emulsifiers used in foods to improve different technological properties. They should conform to the specifications laid down in Commission Regulation No. 231/2012 and be used at amounts not exceeding the maximal ones set by Commission Regulation No. 1129/2011. In order to be able to characterise commercial sucrose ester formulations and to evaluate whether they are used correctly by the food industry, a quantitative GC-FID method was developed. Standards of monoesters and diesters were isolated from commercial additive preparations because no commercial ones were available. Commercial sucrose monolaureate and in-house-synthesised sucrose diarachidonate were used as internal standards. The method showed limits of detection and quantification of 2.9 and 5.7 µg ml(-1) respectively for the monoesters and 42.8 and 129.7 µg ml(-1) respectively for the diesters. The analysed commercial additive formulations contained mainly mono- and diesters of palmitic and stearic acid with low amounts of free fatty acid and sucrose. Different food matrices were incurred with commercial sucrose esters formulations and recoveries ranged between 92% and 118% for the monoesters and between 77% and 120% for the diesters. Recovery of sucrose monoesters in cake was around 34% when no enzymatic treatment was applied, and about 64% when enzymatic treatment with Clara-Diastase was applied. This indicated that sucrose esters can interact strongly with the matrix during food production and that treatment with enzymes is essential to determine the esters' content accurately in some classes of food products.

21 CFR 172.830 - Succinylated monoglycerides.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of glycerol with edible fat-forming fatty acids. (b) The additive meets the following specifications: Succinic acid content: 14.8%-25.6% Melting point: 50 °C-60 °C. Acid number: 70-120 (c) The additive is used... additive is a mixture of semi-and neutral succinic acid esters of mono- and diglycerides produced by the...

21 CFR 184.1328 - Glyceryl behenate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... glyceryl esters of behenic acid made from glycerin and behenic acid (a saturated C22 fatty acid). The... not more than 2.5 percent free fatty acids. (2) Behenic acid. Between 80 and 90 percent of the total fatty acid content. (3) Acid value. Not more than 4. (4) Saponification value. Between 145 and 165. (5...

Oil content in seeds of the NPGS jojoba (Simmondsia chinensis) germplasm collection

USDA-ARS?s Scientific Manuscript database

Jojoba, Simmondsia chinensis, (Link) Schneider is a shrub native to warm and arid land regions of North and Latin America. Its seeds contain vegetable oil composed of long (C20-22), straight-chain liquid wax of non-glyceride esters. Minute amounts of triglycerides in its composition make the oil a l...

21 CFR 184.1328 - Glyceryl behenate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... glyceryl esters of behenic acid made from glycerin and behenic acid (a saturated C22 fatty acid). The... not more than 2.5 percent free fatty acids. (2) Behenic acid. Between 80 and 90 percent of the total fatty acid content. (3) Acid value. Not more than 4. (4) Saponification value. Between 145 and 165. (5...

40 CFR 180.960 - Polymers; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-hydroxypoly (oxypropylene) and/or poly (oxyethylene) polymers where the alkyl chain contains a minimum of six...) block copolymer; the minimum poly(oxypropylene) content is 27 moles and the minimum molecular weight (in... weight (in amu), 900,000 62386-95-2 Monophosphate ester of the block copolymer α-hydro-ω-hydroxypoly...

40 CFR 180.960 - Polymers; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-hydroxypoly (oxypropylene) and/or poly (oxyethylene) polymers where the alkyl chain contains a minimum of six... (oxypropylene) poly(oxyethylene) block copolymer; the minimum poly(oxypropylene) content is 27 moles and the... number average molecular weight (in amu), 900,000 62386-95-2 Monophosphate ester of the block copolymer α...

Ortho-phthalic acid esters in lipophilic extract from the cell culture of Aconitum baicalense Turcz ex Rapaics 1907.

PubMed

Semenov, A A; Enikeev, A G; Snetkova, L V; Permyakov, A V; Sokolova, N A; Dudareva, L V

2016-11-01

Optically active bis-2R(-)ethylhexyl o-phthalate was obtained with 0.18% yield from dry cultured cells of Aconitum baicalense Turcz ex Rapaics 1907 by extraction with petroleum ether followed by silica gel column chromatography. Its structure was confirmed by the analysis of 13 C and 1 H NMR spectra. Seasonal fluctuations of quantitative phthalate content in A. baicalense cells were identified. The tests were performed under conditions excluding the presence of phthalates in reagents, materials, and laboratory dishes. The same substance was shown to be produced by cultivated cells of other plants. Biosynthesis of esters of ortho-phthalic acid by cultivated plant cells was discovered for the first time.

Effects of low frequency ultrasonic treatment on the maturation of steeped greengage wine.

PubMed

Zheng, Xinhua; Zhang, Min; Fang, Zhongxiang; Liu, Yaping

2014-11-01

To accelerate wine maturation, low frequency ultrasonic waves of 28 kHz and 45 kHz were used to treat the steeped greengage wine. The contents of total acid, total ester, fusel oils and the wine chromaticity were determined before and after the ultrasonic treatment. The volatile compounds were analysed by GC-MS method, and the sensory quality was evaluated by panelist. The results indicated that ultrasonic treatment of the steeped greengage wine at 45 kHz 360 W for 30 min was effective to accelerate the aging process, where the fusel oils and alcohol compounds were significantly reduced and acid and ester compounds were significantly increased. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of physicochemical parameters and high pressure processing on the volatile compounds of Serrano dry-cured ham after prolonged refrigerated storage.

PubMed

Martínez-Onandi, N; Rivas-Cañedo, A; Picon, A; Nuñez, M

2016-12-01

One hundred and three volatile compounds were detected by solid-phase microextraction followed by gas chromatography-mass spectrometry in 30 ripened Serrano dry-cured hams, submitted or not to high pressure processing (HPP) and afterwards held for 5months at 4°C. The effect of ham physicochemical parameters and HPP (600MPa for 6min) on volatile compounds was assessed. Physicochemical parameters primarily affected the levels of acids, alcohols, alkanes, esters, benzene compounds, sulfur compounds and some miscellaneous compounds. Intramuscular fat content was the physicochemical parameter with the most pronounced effect on the volatile fraction of untreated Serrano ham after refrigerated storage, influencing the levels of 38 volatile compounds while aw, salt content and salt-in-lean ratio respectively influenced the levels of 4, 4 and 5 volatile compounds. HPP treatment affected 21 volatile compounds, resulting in higher levels of alkanes and ketones and lower levels of esters and secondary alcohols, what might affect Serrano ham odor and aroma after 5months of refrigerated storage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of biodiesel from plant oil hydrolysates using an Aspergillus oryzae whole-cell biocatalyst highly expressing Candida antarctica lipase B.

PubMed

Adachi, Daisuke; Hama, Shinji; Nakashima, Kazunori; Bogaki, Takayuki; Ogino, Chiaki; Kondo, Akihiko

2013-05-01

For enzymatic biodiesel production from plant oil hydrolysates, an Aspergillus oryzae whole-cell biocatalyst that expresses Candida antarctica lipase B (r-CALB) with high esterification activity was developed. Each of soybean and palm oils was hydrolyzed using Candida rugosa lipase, and the resultant hydrolysates were subjected to esterification where immobilized r-CALB was used as a catalyst. In esterification, r-CALB afforded a methyl ester content of more than 90% after 6 h with the addition of 1.5 M equivalents of methanol. Favorably, stepwise additions of methanol and a little water were unnecessary for maintaining the lipase stability of r-CALB during esterification. During long-term esterification in a rotator, r-CALB can be recycled for 20 cycles without a significant loss of lipase activity, resulting in a methyl ester content of more than 90% even after the 20th batch. Therefore, the presented reaction system using r-CALB shows promise for biodiesel production from plant oil hydrolysates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Isolation and screening of heterocystous cyanobacterial strains for biodiesel production by evaluating the fuel properties from fatty acid methyl ester (FAME) profiles.

PubMed

Anahas, Antonyraj Matharasi Perianaika; Muralitharan, Gangatharan

2015-05-01

This study reports on the biodiesel quality parameters of eleven heterocystous cyanobacterial strains based on fatty acid methyl esters (FAME) profiles. The biomass productivity of the tested cyanobacterial strains ranged from 9.33 to 20.67 mg L(-1) d(-1) while the lipid productivity varied between 0.65 and 2.358 mg L(-1) d(-1). The highest biomass and lipid productivity was observed for Calothrix sp. MBDU 013 but its lipid content is only 11.221 in terms of percent dry weight, next to the Anabaena sphaerica MBDU 105, whose lipid content is high. To identify the most competent isolate, a multi-criteria decision analyses (MCDA) was performed by including the key chemical and physical parameters of biodiesel calculated from FAME profiles. The isolate A.sphaerica MBDU 105 is the most promising biodiesel feed stock based on decision vector through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA) analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.