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Sample records for cholesterol trafficking parallels

  1. Early steps in steroidogenesis: intracellular cholesterol trafficking.

    PubMed

    Miller, Walter L; Bose, Himangshu S

    2011-12-01

    Steroid hormones are made from cholesterol, primarily derived from lipoproteins that enter cells via receptor-mediated endocytosis. In endo-lysosomes, cholesterol is released from cholesterol esters by lysosomal acid lipase (LAL; disordered in Wolman disease) and exported via Niemann-Pick type C (NPC) proteins (disordered in NPC disease). These diseases are characterized by accumulated cholesterol and cholesterol esters in most cell types. Mechanisms for trans-cytoplasmic cholesterol transport, membrane insertion, and retrieval from membranes are less clear. Cholesterol esters and "free" cholesterol are enzymatically interconverted in lipid droplets. Cholesterol transport to the cholesterol-poor outer mitochondrial membrane (OMM) appears to involve cholesterol transport proteins. Cytochrome P450scc (CYP11A1) then initiates steroidogenesis by converting cholesterol to pregnenolone on the inner mitochondrial membrane (IMM). Acute steroidogenic responses are regulated by cholesterol delivery from OMM to IMM, triggered by the steroidogenic acute regulatory protein (StAR). Chronic steroidogenic capacity is determined by CYP11A1 gene transcription. StAR mutations cause congenital lipoid adrenal hyperplasia, with absent steroidogenesis, potentially lethal salt loss, and 46,XY sex reversal. StAR mutations initially destroy most, but not all steroidogenesis; low levels of StAR-independent steroidogenesis are lost later due to cellular damage, explaining the clinical findings. Rare P450scc mutations cause a similar syndrome. This review addresses these early steps in steroid biosynthesis. PMID:21976778

  2. Early steps in steroidogenesis: intracellular cholesterol trafficking

    PubMed Central

    Miller, Walter L.; Bose, Himangshu S.

    2011-01-01

    Steroid hormones are made from cholesterol, primarily derived from lipoproteins that enter cells via receptor-mediated endocytosis. In endo-lysosomes, cholesterol is released from cholesterol esters by lysosomal acid lipase (LAL; disordered in Wolman disease) and exported via Niemann-Pick type C (NPC) proteins (disordered in NPC disease). These diseases are characterized by accumulated cholesterol and cholesterol esters in most cell types. Mechanisms for trans-cytoplasmic cholesterol transport, membrane insertion, and retrieval from membranes are less clear. Cholesterol esters and “free” cholesterol are enzymatically interconverted in lipid droplets. Cholesterol transport to the cholesterol-poor outer mitochondrial membrane (OMM) appears to involve cholesterol transport proteins. Cytochrome P450scc (CYP11A1) then initiates steroidogenesis by converting cholesterol to pregnenolone on the inner mitochondrial membrane (IMM). Acute steroidogenic responses are regulated by cholesterol delivery from OMM to IMM, triggered by the steroidogenic acute regulatory protein (StAR). Chronic steroidogenic capacity is determined by CYP11A1 gene transcription. StAR mutations cause congenital lipoid adrenal hyperplasia, with absent steroidogenesis, potentially lethal salt loss, and 46,XY sex reversal. StAR mutations initially destroy most, but not all steroidogenesis; low levels of StAR-independent steroidogenesis are lost later due to cellular damage, explaining the clinical findings. Rare P450scc mutations cause a similar syndrome. This review addresses these early steps in steroid biosynthesis. PMID:21976778

  3. Analysis of cholesterol trafficking with fluorescent probes

    PubMed Central

    Maxfield, Frederick R.; Wüstner, Daniel

    2013-01-01

    Cholesterol plays an important role in determining the biophysical properties of biological membranes, and its concentration is tightly controlled by homeostatic processes. The intracellular transport of cholesterol among organelles is a key part of the homeostatic mechanism, but sterol transport processes are not well understood. Fluorescence microscopy is a valuable tool for studying intracellular transport processes, but this method can be challenging for lipid molecules because addition of a fluorophore may alter the properties of the molecule greatly. We discuss the use of fluorescent molecules that can bind to cholesterol to reveal its distribution in cells. We also discuss the use of intrinsically fluorescent sterols that closely mimic cholesterol, as well as some minimally modified fluorophore-labeled sterols. Methods for imaging these sterols by conventional fluorescence microscopy and by multiphoton microscopy are described. Some label-free methods for imaging cholesterol itself are also discussed briefly. PMID:22325611

  4. Fluorescence Techniques Using Dehydroergosterol to Study Cholesterol Trafficking

    PubMed Central

    McIntosh, Avery L.; Atshaves, Barbara P.; Huang, Huan; Gallegos, Adalberto M.; Kier, Ann B.; Schroeder, Friedhelm

    2008-01-01

    Cholesterol itself has very few structural/chemical features suitable for real-time imaging in living cells. Thus, the advent of dehydroergosterol [ergosta-5,7,9(11),22-tetraen-3β-ol, DHE] the fluorescent sterol most structurally and functionally similar to cholesterol to date, has proven to be a major asset for real-time probing/elucidating the sterol environment and intracellular sterol trafficking in living organisms. DHE is a naturally-occurring, fluorescent sterol analog that faithfully mimics many of the properties of cholesterol. Because these properties are very sensitive to sterol structure and degradation, such studies require the use of extremely pure (>98%) quantities of fluorescent sterol. DHE is readily bound by cholesterol-binding proteins, is incorporated into lipoproteins (from the diet of animals or by exchange in vitro), and for real-time imaging studies is easily incorporated into cultured cells where it co-distributes with endogenous sterol. Incorporation from an ethanolic stock solution to cell culture media is effective, but this process forms an aqueous dispersion of dehydroergosterol crystals which can result in endocytic cellular uptake and distribution into lysosomes which is problematic in imaging DHE at the plasma membrane of living cells. In contrast, monomeric DHE can be incorporated from unilamellar vesicles by exchange/fusion with the plasma membrane or from DHE-methyl-β-cyclodextrin (DHE-MβCD) complexes by exchange with the plasma membrane. Both of the latter techniques can deliver large quantities of monomeric dehydroergosterol with significant distribution into the plasma membrane. The properties and behavior of DHE in protein-binding, lipoproteins, model membranes, biological membranes, lipid rafts/caveolae, and real-time imaging in living cells indicate that this naturally-occurring fluorescent sterol is a useful mimic for probing the properties of cholesterol in these systems. PMID:18536950

  5. Endosomal cholesterol trafficking: protein factors at a glance.

    PubMed

    Du, Ximing; Yang, Hongyuan

    2013-01-01

    The delivery of low-density lipoprotein-derived cholesterol (LDL-C) from endosomal compartments to the plasma membrane and the endoplasmic reticulum (ER) is an important yet poorly understood cellular process. Niemann-Pick C1 (NPC1), a multi-pass integral membrane protein on the limiting membranes of late endosomes (LE)/lysosomes (Ly), is known to insert lumenal LDL-C to the limiting membrane of LE/Ly. Recent progress has identified novel cytoplasmic proteins that regulate the exit of LDL-C from LE/Ly, such as ORP5, a member of the oxysterol-binding protein-related protein (ORPs) family, and Hrs/VPS27, a well-established regulator of the endosomal sorting complex required for transport pathway. Whereas ORP5/ORPs may serve as cytosolic cholesterol carriers and deliver cholesterol in a non-vesicular manner, how Hrs/VPS27 regulate endosomal cholesterol sorting remains enigmatic. We discuss the functional relationship between NPC1, Hrs, and ORP5, and formulate possible schemes on how LDL-C may be moved from endosomal compartments to other cellular organelles. PMID:23165745

  6. A role for oxysterol-binding protein–related protein 5 in endosomal cholesterol trafficking

    PubMed Central

    Du, Ximing; Kumar, Jaspal; Ferguson, Charles; Schulz, Timothy A.; Ong, Yan Shan; Hong, Wanjin; Prinz, William A.; Parton, Robert G.; Brown, Andrew J.

    2011-01-01

    Oxysterol-binding protein (OSBP) and its related proteins (ORPs) constitute a large and evolutionarily conserved family of lipid-binding proteins that target organelle membranes to mediate sterol signaling and/or transport. Here we characterize ORP5, a tail-anchored ORP protein that localizes to the endoplasmic reticulum. Knocking down ORP5 causes cholesterol accumulation in late endosomes and lysosomes, which is reminiscent of the cholesterol trafficking defect in Niemann Pick C (NPC) fibroblasts. Cholesterol appears to accumulate in the limiting membranes of endosomal compartments in ORP5-depleted cells, whereas depletion of NPC1 or both ORP5 and NPC1 results in luminal accumulation of cholesterol. Moreover, trans-Golgi resident proteins mislocalize to endosomal compartments upon ORP5 depletion, which depends on a functional NPC1. Our results establish the first link between NPC1 and a cytoplasmic sterol carrier, and suggest that ORP5 may cooperate with NPC1 to mediate the exit of cholesterol from endosomes/lysosomes. PMID:21220512

  7. Inhibition of angiogenesis by selective estrogen receptor modulators through blockade of cholesterol trafficking rather than estrogen receptor antagonism.

    PubMed

    Shim, Joong Sup; Li, Ruo-Jing; Lv, Junfang; Head, Sarah A; Yang, Eun Ju; Liu, Jun O

    2015-06-28

    Selective estrogen receptor modulators (SERM) including tamoxifen are known to inhibit angiogenesis. However, the underlying mechanism, which is independent of their action on the estrogen receptor (ER), has remained largely unknown. In the present study, we found that tamoxifen and other SERM inhibited cholesterol trafficking in endothelial cells, causing a hyper-accumulation of cholesterol in late endosomes/lysosomes. Inhibition of cholesterol trafficking by tamoxifen was accompanied by abnormal subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR2) and inhibition of the terminal glycosylation of the receptor. Tamoxifen also caused perinuclear positioning of lysosomes, which in turn trapped the mammalian target of rapamycin (mTOR) in the perinuclear region of endothelial cells. Abnormal distribution of VEGFR2 and mTOR and inhibition of VEGFR2 and mTOR activities by tamoxifen were significantly reversed by addition of cholesterol-cyclodextrin complex to the culture media of endothelial cells. Moreover, high concentrations of tamoxifen inhibited endothelial and breast cancer cell proliferation in a cholesterol-dependent, but ER-independent, manner. Together, these results unraveled a previously unrecognized mechanism of angiogenesis inhibition by tamoxifen and other SERM, implicating cholesterol trafficking as an attractive therapeutic target for cancer treatment.

  8. Synthesis and validation of novel cholesterol-based fluorescent lipids designed to observe the cellular trafficking of cationic liposomes.

    PubMed

    Kim, Bieong-Kil; Seu, Young-Bae; Choi, Jong-Soo; Park, Jong-Won; Doh, Kyung-Oh

    2015-09-15

    Cholesterol-based fluorescent lipids with ether linker were synthesized using NBD (Chol-E-NBD) or Rhodamine B (Chol-E-Rh), and the usefulnesses as fluorescent probes for tracing cholesterol-based liposomes were validated. The fluorescent intensities of liposomes containing these modified lipids were measured and observed under a microscope. Neither compound interfered with the expression of GFP plasmid, and live cell images were obtained without interferences. Changes in the fluorescent intensity of liposomes containing Chol-E-NBD were followed by flow cytometry for up to 24h. These fluorescent lipids could be useful probes for trafficking of cationic liposome-mediated gene delivery. PMID:26243368

  9. Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells.

    PubMed

    Li, Nancy C; Fan, Jinjiang; Papadopoulos, Vassilios

    2016-01-01

    Sterol carrier protein-2 (SCP2), also called nonspecific lipid-transfer protein, is thought to play a major role in intracellular lipid transport and metabolism, and it has been associated with diseases involving abnormalities in lipid trafficking, such as Zellweger syndrome. The Scp2 gene encodes the 58 kDa sterol carrier protein-x (SCPX) and 15 kDa pro-SCP2 proteins, both of which contain a 13 kDa SCP2 domain in their C-termini. We found that 22-NBD-cholesterol, a fluorescent analog of cholesterol and a preferred SCP2 ligands, was not localized in the peroxisomes. This raises questions about previous reports on the localization of the SCPX and SCP2 proteins and their relationship to peroxisomes and mitochondria in intracellular cholesterol transport. Immunofluorescent staining of cryosections of mouse testis and of MA-10 mouse tumor Leydig cells showed that SCPX and SCP2 are present in both mouse testicular interstitial tissue and in MA-10 cells. Fluorescent fusion proteins of SCPX and SCP2, as well as confocal live-cell imaging, were used to investigate the subcellular targeting of these proteins and the function of the putative mitochondrial targeting sequence. The results showed that SCPX and SCP2 are targeted to the peroxisomes by the C-terminal PTS1 domain, but the putative N-terminal mitochondrial targeting sequence alone is not potent enough to localize SCPX and SCP2 to the mitochondria. Homology modeling and molecular docking studies indicated that the SCP2 domain binds cholesterol, but lacks specificity of the binding and/or transport. These findings further our understanding of the role of SCPX and SCP2 in intracellular cholesterol transport, and present a new point of view on the role of these proteins in cholesterol trafficking.

  10. Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells

    PubMed Central

    Li, Nancy C.; Fan, Jinjiang; Papadopoulos, Vassilios

    2016-01-01

    Sterol carrier protein-2 (SCP2), also called nonspecific lipid-transfer protein, is thought to play a major role in intracellular lipid transport and metabolism, and it has been associated with diseases involving abnormalities in lipid trafficking, such as Zellweger syndrome. The Scp2 gene encodes the 58 kDa sterol carrier protein-x (SCPX) and 15 kDa pro-SCP2 proteins, both of which contain a 13 kDa SCP2 domain in their C-termini. We found that 22-NBD-cholesterol, a fluorescent analog of cholesterol and a preferred SCP2 ligands, was not localized in the peroxisomes. This raises questions about previous reports on the localization of the SCPX and SCP2 proteins and their relationship to peroxisomes and mitochondria in intracellular cholesterol transport. Immunofluorescent staining of cryosections of mouse testis and of MA-10 mouse tumor Leydig cells showed that SCPX and SCP2 are present in both mouse testicular interstitial tissue and in MA-10 cells. Fluorescent fusion proteins of SCPX and SCP2, as well as confocal live-cell imaging, were used to investigate the subcellular targeting of these proteins and the function of the putative mitochondrial targeting sequence. The results showed that SCPX and SCP2 are targeted to the peroxisomes by the C-terminal PTS1 domain, but the putative N-terminal mitochondrial targeting sequence alone is not potent enough to localize SCPX and SCP2 to the mitochondria. Homology modeling and molecular docking studies indicated that the SCP2 domain binds cholesterol, but lacks specificity of the binding and/or transport. These findings further our understanding of the role of SCPX and SCP2 in intracellular cholesterol transport, and present a new point of view on the role of these proteins in cholesterol trafficking. PMID:26901662

  11. Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells.

    PubMed

    Li, Nancy C; Fan, Jinjiang; Papadopoulos, Vassilios

    2016-01-01

    Sterol carrier protein-2 (SCP2), also called nonspecific lipid-transfer protein, is thought to play a major role in intracellular lipid transport and metabolism, and it has been associated with diseases involving abnormalities in lipid trafficking, such as Zellweger syndrome. The Scp2 gene encodes the 58 kDa sterol carrier protein-x (SCPX) and 15 kDa pro-SCP2 proteins, both of which contain a 13 kDa SCP2 domain in their C-termini. We found that 22-NBD-cholesterol, a fluorescent analog of cholesterol and a preferred SCP2 ligands, was not localized in the peroxisomes. This raises questions about previous reports on the localization of the SCPX and SCP2 proteins and their relationship to peroxisomes and mitochondria in intracellular cholesterol transport. Immunofluorescent staining of cryosections of mouse testis and of MA-10 mouse tumor Leydig cells showed that SCPX and SCP2 are present in both mouse testicular interstitial tissue and in MA-10 cells. Fluorescent fusion proteins of SCPX and SCP2, as well as confocal live-cell imaging, were used to investigate the subcellular targeting of these proteins and the function of the putative mitochondrial targeting sequence. The results showed that SCPX and SCP2 are targeted to the peroxisomes by the C-terminal PTS1 domain, but the putative N-terminal mitochondrial targeting sequence alone is not potent enough to localize SCPX and SCP2 to the mitochondria. Homology modeling and molecular docking studies indicated that the SCP2 domain binds cholesterol, but lacks specificity of the binding and/or transport. These findings further our understanding of the role of SCPX and SCP2 in intracellular cholesterol transport, and present a new point of view on the role of these proteins in cholesterol trafficking. PMID:26901662

  12. Cholesterol dependence of collagen and echovirus 1 trafficking along the novel α2β1 integrin internalization pathway.

    PubMed

    Siljamäki, Elina; Rintanen, Nina; Kirsi, Maija; Upla, Paula; Wang, Wei; Karjalainen, Mikko; Ikonen, Elina; Marjomäki, Varpu

    2013-01-01

    We have previously shown that soluble collagen and a human pathogen, echovirus 1 (EV1) cluster α2β1 integrin on the plasma membrane and cause their internalization into cytoplasmic endosomes. Here we show that cholesterol plays a major role not only in the uptake of α2β1 integrin and its ligands but also in the formation of α2 integrin-specific multivesicular bodies (α2-MVBs) and virus infection. EV1 infection and α2β1 integrin internalization were totally halted by low amounts of the cholesterol-aggregating drugs filipin or nystatin. Inhibition of cholesterol synthesis and accumulation of lanosterol after ketoconazole treatment inhibited uptake of collagen, virus and clustered integrin, and prevented formation of multivesicular bodies and virus infection. Loading of lipid starved cells with cholesterol increased infection to some extent but could not completely restore EV1 infection to control levels. Cold Triton X-100 treatment did not solubilize the α2-MVBs suggesting, together with cholesterol labeling, that the cytoplasmic endosomes were enriched in detergent-resistant lipids in contrast to αV integrin labeled control endosomes in the clathrin pathway. Cholesterol aggregation leading to increased ion permeability caused a significant reduction in EV1 uncoating in endosomes as judged by sucrose gradient centrifugation and by neutral red-based uncoating assay. In contrast, the replication step was not dependent on cholesterol in contrast to the reports on several other viruses. In conclusion, our results showed that the integrin internalization pathway is dependent on cholesterol for uptake of collagen, EV1 and integrin, for maturation of endosomal structures and for promoting EV1 uncoating. The results thus provide novel information for developing anti-viral strategies and more insight into collagen and integrin trafficking. PMID:23393580

  13. Electrochemiluminescence imaging for parallel single-cell analysis of active membrane cholesterol.

    PubMed

    Zhou, Junyu; Ma, Guangzhong; Chen, Yun; Fang, Danjun; Jiang, Dechen; Chen, Hong-Yuan

    2015-08-18

    Luminol electrochemiluminescence (ECL) imaging was developed for the parallel measurement of active membrane cholesterol at single living cells, thus establishing a novel electrochemical detection technique for single cells with high analysis throughput and low detection limit. In our strategy, the luminescence generated from luminol and hydrogen peroxide upon the potential was recorded in one image so that hydrogen peroxide at the surface of multiple cells could be simultaneously analyzed. Compared with the classic microelectrode array for the parallel single-cell analysis, the plat electrode only was needed in our ECL imaging, avoiding the complexity of electrode fabrication. The optimized ECL imaging system showed that hydrogen peroxide as low as 10 μM was visible and the efflux of hydrogen peroxide from cells could be determined. Coupled with the reaction between active membrane cholesterol and cholesterol oxidase to generate hydrogen peroxide, active membrane cholesterol at cells on the electrode was analyzed at single-cell level. The luminescence intensity was correlated with the amount of active membrane cholesterol, validating our system for single-cell cholesterol analysis. The relative high standard deviation on the luminescence suggested high cellular heterogeneities on hydrogen peroxide efflux and active membrane cholesterol, which exhibited the significance of single-cell analysis. This success in ECL imaging for single-cell analysis opens a new field in the parallel measurement of surface molecules at single cells.

  14. Cholesterol transport from late endosomes to the Golgi regulates t-SNARE trafficking, assembly, and function

    PubMed Central

    Reverter, Meritxell; Rentero, Carles; de Muga, Sandra Vilà; Alvarez-Guaita, Anna; Mulay, Vishwaroop; Cairns, Rose; Wood, Peta; Monastyrskaya, Katia; Pol, Albert; Tebar, Francesc; Blasi, Joan; Grewal, Thomas; Enrich, Carlos

    2011-01-01

    Cholesterol regulates plasma membrane (PM) association and functioning of syntaxin-4 and soluble N-ethylmaleimide-sensitive fusion protein 23 (SNAP23) in the secretory pathway. However, the molecular mechanism and cellular cholesterol pools that determine the localization and assembly of these target membrane SNAP receptors (t-SNAREs) are largely unknown. We recently demonstrated that high levels of annexin A6 (AnxA6) induce accumulation of cholesterol in late endosomes, thereby reducing cholesterol in the Golgi and PM. This leads to an impaired supply of cholesterol needed for cytosolic phospholipase A2 (cPLA2) to drive Golgi vesiculation and caveolin transport to the cell surface. Using AnxA6-overexpressing cells as a model for cellular cholesterol imbalance, we identify impaired cholesterol egress from late endosomes and diminution of Golgi cholesterol as correlating with the sequestration of SNAP23/syntaxin-4 in Golgi membranes. Pharmacological accumulation of late endosomal cholesterol and cPLA2 inhibition induces a similar phenotype in control cells with low AnxA6 levels. Ectopic expression of Niemann-Pick C1 (NPC1) or exogenous cholesterol restores the location of SNAP23 and syntaxin-4 within the PM. Importantly, AnxA6-mediated mislocalization of these t-SNAREs correlates with reduced secretion of cargo via the SNAP23/syntaxin-4–dependent constitutive exocytic pathway. We thus conclude that inhibition of late endosomal export and Golgi cholesterol depletion modulate t-SNARE localization and functioning along the exocytic pathway. PMID:22039070

  15. Cholesterol regulates Syntaxin 6 trafficking at trans-Golgi network endosomal boundaries.

    PubMed

    Reverter, Meritxell; Rentero, Carles; Garcia-Melero, Ana; Hoque, Monira; Vilà de Muga, Sandra; Alvarez-Guaita, Anna; Conway, James R W; Wood, Peta; Cairns, Rose; Lykopoulou, Lilia; Grinberg, Daniel; Vilageliu, Lluïsa; Bosch, Marta; Heeren, Joerg; Blasi, Juan; Timpson, Paul; Pol, Albert; Tebar, Francesc; Murray, Rachael Z; Grewal, Thomas; Enrich, Carlos

    2014-05-01

    Inhibition of cholesterol export from late endosomes causes cellular cholesterol imbalance, including cholesterol depletion in the trans-Golgi network (TGN). Here, using Chinese hamster ovary (CHO) Niemann-Pick type C1 (NPC1) mutant cell lines and human NPC1 mutant fibroblasts, we show that altered cholesterol levels at the TGN/endosome boundaries trigger Syntaxin 6 (Stx6) accumulation into VAMP3, transferrin, and Rab11-positive recycling endosomes (REs). This increases Stx6/VAMP3 interaction and interferes with the recycling of αVβ3 and α5β1 integrins and cell migration, possibly in a Stx6-dependent manner. In NPC1 mutant cells, restoration of cholesterol levels in the TGN, but not inhibition of VAMP3, restores the steady-state localization of Stx6 in the TGN. Furthermore, elevation of RE cholesterol is associated with increased amounts of Stx6 in RE. Hence, the fine-tuning of cholesterol levels at the TGN-RE boundaries together with a subset of cholesterol-sensitive SNARE proteins may play a regulatory role in cell migration and invasion. PMID:24746815

  16. Late Endosomal Cholesterol Accumulation Leads to Impaired Intra-Endosomal Trafficking

    PubMed Central

    Sobo, Komla; Le Blanc, Isabelle; Luyet, Pierre-Philippe; Fivaz, Marc; Ferguson, Charles; Parton, Robert G.; Gruenberg, Jean; van der Goot, F. Gisou

    2007-01-01

    Background Pathological accumulation of cholesterol in late endosomes is observed in lysosomal storage diseases such as Niemann-Pick type C. We here analyzed the effects of cholesterol accumulation in NPC cells, or as phenocopied by the drug U18666A, on late endosomes membrane organization and dynamics. Methodology/Principal Findings Cholesterol accumulation did not lead to an increase in the raft to non-raft membrane ratio as anticipated. Strikingly, we observed a 2–3 fold increase in the size of the compartment. Most importantly, properties and dynamics of late endosomal intralumenal vesicles were altered as revealed by reduced late endosomal vacuolation induced by the mutant pore-forming toxin ASSP, reduced intoxication by the anthrax lethal toxin and inhibition of infection by the Vesicular Stomatitis Virus. Conclusions/Significance These results suggest that back fusion of intralumenal vesicles with the limiting membrane of late endosomes is dramatically perturbed upon cholesterol accumulation. PMID:17786222

  17. The cross-talk of LDL-cholesterol with cell motility: insights from the Niemann Pick Type C1 mutation and altered integrin trafficking.

    PubMed

    Hoque, Monira; Rentero, Carles; Conway, James R; Murray, Rachael Z; Timpson, Paul; Enrich, Carlos; Grewal, Thomas

    2015-01-01

    Cholesterol is considered indispensible for the recruitment and functioning of integrins in focal adhesions for cell migration. However, the physiological cholesterol pools that control integrin trafficking and focal adhesion assembly remain unclear. Using Niemann Pick Type C1 (NPC) mutant cells, which accumulate Low Density lipoprotein (LDL)-derived cholesterol in late endosomes (LE), several recent studies indicate that LDL-cholesterol has multiple roles in regulating focal adhesion dynamics. Firstly, targeting of endocytosed LDL-cholesterol from LE to focal adhesions controls their formation at the leading edge of migrating cells. Other newly emerging literature suggests that this may be coupled to vesicular transport of integrins, Src kinase and metalloproteases from the LE compartment to focal adhesions. Secondly, our recent work identified LDL-cholesterol as a key factor that determines the distribution and ability of several Soluble NSF Attachment Protein (SNAP) Receptor (SNARE) proteins, key players in vesicle transport, to control integrin trafficking to the cell surface and extracellular matrix (ECM) secretion. Collectively, dietary, genetic and pathological changes in cholesterol metabolism may link with efficiency and speed of integrin and ECM cell surface delivery in metastatic cancer cells. This commentary will summarize how direct and indirect pathways enable LDL-cholesterol to modulate cell motility.

  18. SPTLC1 binds ABCA1 to negatively regulate trafficking and cholesterol efflux activity of the transporter.

    PubMed

    Tamehiro, Norimasa; Zhou, Suiping; Okuhira, Keiichiro; Benita, Yair; Brown, Cari E; Zhuang, Debbie Z; Latz, Eicke; Hornemann, Thorsten; von Eckardstein, Arnold; Xavier, Ramnik J; Freeman, Mason W; Fitzgerald, Michael L

    2008-06-10

    ABCA1 transport of cholesterol and phospholipids to nascent HDL particles plays a central role in lipoprotein metabolism and macrophage cholesterol homeostasis. ABCA1 activity is regulated both at the transcriptional level and at the post-translational level. To explore mechanisms involved in the post-translational regulation of the transporter, we have used affinity purification and mass spectrometry to identify proteins that bind ABCA1 and influence its activity. Previously, we demonstrated that an interaction between beta1-syntrophin stimulated ABCA1 activity, at least in part, be slowing the degradation of the transporter. This work demonstrates that one subunit of the serine palmitoyltransferase enzyme, SPTLC1, but not subunit 2 (SPTLC2), is copurified with ABCA1 and negatively regulates its function. In human THP-I macrophages and in mouse liver, the ABCA1-SPTLC1 complex was detected by co-immunoprecipitation, demonstrating that the interaction occurs in cellular settings where ABCA1 activity is critical for HDL genesis. Pharmacologic inhibition of SPTLC1 with myriocin, which resulted in the disruption of the SPTLC1-ABCA1 complex, and siRNA knockdown of SPTLC1 expression both stimulated ABCA1 efflux by nearly 60% ( p < 0.05). In contrast, dominant-negative mutants of SPTLC1 inhibited ABCA1 efflux, indicating that a reduced level of sphingomyelin synthesis could not explain the effect of myriocin on ABCA1 activity. In 293 cells, the SPTLC1 inhibition of ABCA1 activity led to the blockade of the exit of ABCA1 from the endoplasmic reticulum. In contrast, myriocin treatment of macrophages increased the level of cell surface ABCA1. In composite, these results indicate that the physical interaction of ABCA1 and SPTLC1 results in reduction of ABCA1 activity and that inhibition of this interaction produces enhanced cholesterol efflux. PMID:18484747

  19. Desipramine induces disorder in cholesterol-rich membranes: implications for viral trafficking

    NASA Astrophysics Data System (ADS)

    Pakkanen, Kirsi; Salonen, Emppu; Mäkelä, Anna R.; Oker-Blom, Christian; Vattulainen, Ilpo; Vuento, Matti

    2009-12-01

    In this study, the effect of desipramine (DMI) on phospholipid bilayers and parvoviral entry was elucidated. In atomistic molecular dynamics simulations, DMI was found to introduce disorder in cholesterol-rich phospholipid bilayers. This was manifested by a decrease in the deuterium order parameter SCD as well as an increase in the membrane area. Disordering of the membrane suggested DMI to destabilize cholesterol-rich membrane domains (rafts) in cellular conditions. To relate the raft disrupting ability of DMI with novel biological relevance, we studied the intracellular effect of DMI using canine parvovirus (CPV), a virus known to interact with endosomal membranes and sphingomyelin, as an intracellular probe. DMI was found to cause retention of the virus in intracellular vesicular structures leading to the inhibition of viral proliferation. This implies that DMI has a deleterious effect on the viral traffic. As recycling endosomes and the internal vesicles of multivesicular bodies are known to contain raft components, the effect of desipramine beyond the plasma membrane step could be caused by raft disruption leading to impaired endosomal function and possibly have direct influence on the penetration of the virus through an endosomal membrane.

  20. Regulation of the NPC2 protein-mediated cholesterol trafficking by membrane lipids.

    PubMed

    Gallala, Hichem D; Breiden, Bernadette; Sandhoff, Konrad

    2011-03-01

    Recycling and turnover of cell membranes play a critical role in cell metabolism. The internalization of membranes through the different processes of endocytosis, phagocytosis, and autophagy deliver a considerable amount of membranes and lipids to the endosomal and lysosomal system which is tasked with its degradation. Its failure to do so leads to severe fatal neurodegenerative diseases. In order to better understand how membranes are degraded, we have to investigate the complex interactions that take place in this compartment between complex membrane lipids, enzymes and lipid binding and transfer proteins involved. To this end, we developed lipid transfer and fusion assays which allow us to quantify these interactions and assess their specificity. The published results of these investigations are summarized in this article. One of our main conclusions is that we have provided evidence for the hypothesis that acid sphingomyelinase stimulates Niemann pick disease protein type 2-mediated cholesterol export substantially by converting sphingomyelin to ceramide in the inner membranes of late endosomes.

  1. Regulation of the high-affinity choline transporter activity and trafficking by its association with cholesterol-rich lipid rafts.

    PubMed

    Cuddy, Leah K; Winick-Ng, Warren; Rylett, Rebecca Jane

    2014-03-01

    The sodium-coupled, hemicholinium-3-sensitive, high-affinity choline transporter (CHT) is responsible for transport of choline into cholinergic nerve terminals from the synaptic cleft following acetylcholine release and hydrolysis. In this study, we address regulation of CHT function by plasma membrane cholesterol. We show for the first time that CHT is concentrated in cholesterol-rich lipid rafts in both SH-SY5Y cells and nerve terminals from mouse forebrain. Treatment of SH-SY5Y cells expressing rat CHT with filipin, methyl-β-cyclodextrin (MβC) or cholesterol oxidase significantly decreased choline uptake. In contrast, CHT activity was increased by addition of cholesterol to membranes using cholesterol-saturated MβC. Kinetic analysis of binding of [(3)H]hemicholinium-3 to CHT revealed that reducing membrane cholesterol with MβC decreased both the apparent binding affinity (KD) and maximum number of binding sites (Bmax ); this was confirmed by decreased plasma membrane CHT protein in lipid rafts in cell surface protein biotinylation assays. Finally, the loss of cell surface CHT associated with lipid raft disruption was not because of changes in CHT internalization. In summary, we provide evidence that CHT association with cholesterol-rich rafts is critical for transporter function and localization. Alterations in plasma membrane cholesterol cholinergic nerve terminals could diminish cholinergic transmission by reducing choline availability for acetylcholine synthesis. The sodium-coupled choline transporter CHT moves choline into cholinergic nerve terminals to serve as substrate for acetylcholine synthesis. We show for the first time that CHT is concentrated in cholesterol-rich lipid rafts, and decreasing membrane cholesterol significantly reduces both choline uptake activity and cell surface CHT protein levels. CHT association with cholesterol-rich rafts is critical for its function, and alterations in plasma membrane cholesterol could diminish cholinergic

  2. Human Trafficking

    MedlinePlus

    ... TRAFFICKING (English) Listen < Back to Search FACT SHEET: HUMAN TRAFFICKING (English) Published: August 2, 2012 Topics: Public Awareness , ... organizations that protect and serve trafficking victims. National Human Trafficking Resource Center at 1.888.373.7888 Last ...

  3. Cholesterol-dependent increases in glucosylceramide synthase activity in Niemann-Pick disease type C model cells: Abnormal trafficking of endogenously formed ceramide metabolites by inhibition of the enzyme.

    PubMed

    Hashimoto, Naohiro; Matsumoto, Ikiru; Takahashi, Hiromasa; Ashikawa, Hitomi; Nakamura, Hiroyuki; Murayama, Toshihiko

    2016-11-01

    Sphingolipids such as sphingomyelin and glycosphingolipids (GSLs) derived from glucosylceramide (GlcCer), in addition to cholesterol, accumulate in cells/neurons in Niemann-Pick disease type C (NPC). The activities of acid sphingomyelinase and lysosomal glucocerebrosidase (GCase), which degrade sphingomyelin and GlcCer, respectively, are down-regulated in NPC cells, however, changes in GlcCer synthase activity have not yet been elucidated. We herein demonstrated for the first time that GlcCer synthase activity for the fluorescent ceramide, 4-nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-ceramide) increased in intact NPC1((-/-)) cells and cell lysates without affecting the protein levels. In NBD-ceramide-labeled NPC1((-/-)) cells, NBD-fluorescence preferentially accumulated in the Golgi complex and vesicular specks in the cytoplasm 40 and 150 min, respectively, after labeling, while a treatment for 48 h with the GlcCer synthase inhibitors, N-butyldeoxynojirimycin (NB-DNJ) and 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol, accelerated the appearance of vesicular specks emitting NBD-fluorescence within 40 min. The treatment of NPC1((-/-)) cells with NB-DNJ for 48 h additionally increased the levels of cholesterol, but not those of sphingomyelin. Increases in the activity of GlcCer synthase and formation of vesicular specks emitting NBD-fluorescence in NPC1((-/-)) cells were dependent on cholesterol. LacCer taken up by endocytosis, which accumulated in the Golgi complex in normal cells, accumulated in vesicular specks after 10 and 40 min in NPC1((-/-)) cells, and this response was not accelerated by the NB-DNJ treatment, but was restored by the depletion of cholesterol. The cellular roles for enhanced GlcCer synthesis and increased levels of cholesterol in the trafficking of NBD-ceramide metabolites in NPC1((-/-)) cells have been discussed.

  4. Intracellular cholesterol changes induced by translocator protein (18 kDa) TSPO/PBR ligands.

    PubMed

    Falchi, Angela Maria; Battetta, Barbara; Sanna, Francesca; Piludu, Marco; Sogos, Valeria; Serra, Mariangela; Melis, Marta; Putzolu, Martina; Diaz, Giacomo

    2007-08-01

    One of the main functions of the translocator protein (18 kDa) or TSPO, previously known as peripheral-type benzodiazepine receptor, is the regulation of cholesterol import into mitochondria for steroid biosynthesis. In this paper we show that TSPO ligands induce changes in the distribution of intracellular cholesterol in astrocytes and fibroblasts. NBD-cholesterol, a fluorescent analog of cholesterol, was rapidly removed from membranes and accumulated into lipid droplets. This change was followed by a block of cholesterol esterification, but not by modification of intracellular cholesterol synthesis. NBD-cholesterol droplets were in part released in the medium, and increased cholesterol efflux was observed in [(3)H]cholesterol-prelabeled cells. TSPO ligands also induced a prominent shrinkage and depolarization of mitochondria and depletion of acidic vesicles with cytoplasmic acidification. Consistent with NBD-cholesterol changes, MTT assay showed enhanced accumulation of formazan into lipid droplets and inhibition of formazan exocytosis after treatment with TSPO ligands. The effects of specific TSPO ligands PK 11195 and Ro5-4864 were reproduced by diazepam, which binds with high affinity both TSPO and central benzodiazepine receptors, but not by clonazepam, which binds exclusively to GABA receptor, and other amphiphilic substances such as DIDS and propranolol. All these effects and the parallel immunocytochemical detection of TSPO in potentially steroidogenic cells (astrocytes) and non-steroidogenic cells (fibroblasts) suggest that TSPO is involved in the regulation and trafficking of intracellular cholesterol by means of mechanisms not necessarily related to steroid biosynthesis.

  5. Phosphatidylcholine: Greasing the Cholesterol Transport Machinery

    PubMed Central

    Lagace, Thomas A.

    2015-01-01

    Negative feedback regulation of cholesterol metabolism in mammalian cells ensures a proper balance of cholesterol with other membrane lipids, principal among these being the major phospholipid phosphatidylcholine (PC). Processes such as cholesterol biosynthesis and efflux, cholesteryl ester storage in lipid droplets, and uptake of plasma lipoproteins are tuned to the cholesterol/PC ratio. Cholesterol-loaded macrophages in atherosclerotic lesions display increased PC biosynthesis that buffers against elevated cholesterol levels and may also facilitate cholesterol trafficking to enhance cholesterol sensing and efflux. These same mechanisms could play a generic role in homeostatic responses to acute changes in membrane free cholesterol levels. Here, I discuss the established and emerging roles of PC metabolism in promoting intracellular cholesterol trafficking and membrane lipid homeostasis. PMID:27081313

  6. Effects of psyllium on LDL-cholesterol concentrations in Brazilian children and adolescents: a randomised, placebo-controlled, parallel clinical trial.

    PubMed

    Ribas, Simone Augusta; Cunha, Diana Barbosa; Sichieri, Rosely; Santana da Silva, Luiz Carlos

    2015-01-14

    The present study investigated the LDL-cholesterol (LDL-C)-lowering effects of psyllium in Brazilian dyslipidaemic children and adolescents. A total of fifty-one individuals (6-19 years) with mild-to-moderate hypercholesterolaemia were evaluated by conducting a randomised, double-blind, placebo-controlled, parallel clinical trial. Over an 8-week trial period, the participants were randomly allocated to one of two groups (control: n 25 and psyllium: n 26) using a computer-generated random number sequence. Fasting blood samples, dietary records and anthropometric data were collected. Both groups were treated with the National Cholesterol Education Program Step 2 diet for 6 weeks before randomisation. After this run-in period, a daily supplement of 7·0 g psyllium was given to the intervention group, while an equivalent amount of cellulose was given to the control group. Statistically significant changes between the control and intervention groups over time were observed for total cholesterol (7·7%; - 0·39 mmol/l; P= 0·003) and LDL-C (10·7%; - 0·36 mmol/l; P= 0·01). None of the participants reported any aversion to the smell, taste, appearance or texture of psyllium. No serious adverse effects were reported during the study. In addition to causing a significant reduction in LDL-C concentrations, psyllium therapy was found to be both safe and acceptable for the treatment of hypercholesterolaemic children and adolescents.

  7. Human Trafficking

    ERIC Educational Resources Information Center

    Wilson, David McKay

    2011-01-01

    The shadowy, criminal nature of human trafficking makes evaluating its nature and scope difficult. The U.S. State Department and anti-trafficking groups estimate that worldwide some 27 million people are caught in a form of forced servitude today. Public awareness of modern-day slavery is gaining momentum thanks to new abolitionist efforts. Among…

  8. What's Cholesterol?

    MedlinePlus

    ... Most cholesterol is LDL (low-density lipoprotein) cholesterol. LDL cholesterol is more likely to clog blood vessels because ... Here's a way to remember the difference: the LDL cholesterol is the bad kind, so call it "lousy" ...

  9. About Cholesterol

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More About Cholesterol Updated:Aug 10,2016 It may surprise you ... our bodies to keep us healthy. What is cholesterol and where does it come from? Cholesterol is ...

  10. Economics of human trafficking.

    PubMed

    Wheaton, Elizabeth M; Schauer, Edward J; Galli, Thomas V

    2010-01-01

    Because freedom of choice and economic gain are at the heart of productivity, human trafficking impedes national and international economic growth. Within the next 10 years, crime experts expect human trafficking to surpass drug and arms trafficking in its incidence, cost to human well-being, and profitability to criminals (Schauer and Wheaton, 2006: 164-165). The loss of agency from human trafficking as well as from modern slavery is the result of human vulnerability (Bales, 2000: 15). As people become vulnerable to exploitation and businesses continually seek the lowest-cost labour sources, trafficking human beings generates profit and a market for human trafficking is created. This paper presents an economic model of human trafficking that encompasses all known economic factors that affect human trafficking both across and within national borders. We envision human trafficking as a monopolistically competitive industry in which traffickers act as intermediaries between vulnerable individuals and employers by supplying differentiated products to employers. In the human trafficking market, the consumers are employers of trafficked labour and the products are human beings. Using a rational-choice framework of human trafficking we explain the social situations that shape relocation and working decisions of vulnerable populations leading to human trafficking, the impetus for being a trafficker, and the decisions by employers of trafficked individuals. The goal of this paper is to provide a common ground upon which policymakers and researchers can collaborate to decrease the incidence of trafficking in humans.

  11. Economics of human trafficking.

    PubMed

    Wheaton, Elizabeth M; Schauer, Edward J; Galli, Thomas V

    2010-01-01

    Because freedom of choice and economic gain are at the heart of productivity, human trafficking impedes national and international economic growth. Within the next 10 years, crime experts expect human trafficking to surpass drug and arms trafficking in its incidence, cost to human well-being, and profitability to criminals (Schauer and Wheaton, 2006: 164-165). The loss of agency from human trafficking as well as from modern slavery is the result of human vulnerability (Bales, 2000: 15). As people become vulnerable to exploitation and businesses continually seek the lowest-cost labour sources, trafficking human beings generates profit and a market for human trafficking is created. This paper presents an economic model of human trafficking that encompasses all known economic factors that affect human trafficking both across and within national borders. We envision human trafficking as a monopolistically competitive industry in which traffickers act as intermediaries between vulnerable individuals and employers by supplying differentiated products to employers. In the human trafficking market, the consumers are employers of trafficked labour and the products are human beings. Using a rational-choice framework of human trafficking we explain the social situations that shape relocation and working decisions of vulnerable populations leading to human trafficking, the impetus for being a trafficker, and the decisions by employers of trafficked individuals. The goal of this paper is to provide a common ground upon which policymakers and researchers can collaborate to decrease the incidence of trafficking in humans. PMID:20645472

  12. Cholesterol (image)

    MedlinePlus

    Cholesterol is a soft, waxy substance that is present in all parts of the body including the ... and obtained from animal products in the diet. Cholesterol is manufactured in the liver and is needed ...

  13. Lipid content in hepatic and gonadal adipose tissue parallel aortic cholesterol accumulation in mice fed diets with different omega-6 PUFA to EPA plus DHA ratios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diets with low omega (u)-6 polyunsaturated fatty acids (PUFA) to eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) ratios have been shown to decrease aortic cholesterol accumulation and have been suggested to promote weight loss. The involvement of the liver and gonadal adipose tissue (GAT...

  14. The Structural Basis of Cholesterol Activity in Membranes

    SciTech Connect

    Olsen, Brett N.; Bielska, Agata; Lee, Tiffany; Daily, Michael D.; Covey, Douglas F.; Schlesinger, Paul H.; Baker, Nathan A.; Ory, Daniel S.

    2013-10-15

    Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes modulates ER membrane behavior. Previous studies have predominantly examined cholesterol availability in terms of binding to extramembrane acceptors, but have provided limited insight into the structural changes underlying cholesterol activation. In this study, we use both molecular dynamics simulations and experimental membrane systems to examine the behavior of cholesterol in membrane bilayers. We find that cholesterol depth within the bilayer provides a reasonable structural metric for cholesterol availability and that this is correlated with cholesterol-acceptor binding. Further, the distribution of cholesterol availability in our simulations is continuous rather than divided into distinct available and unavailable pools. This data provide support for a revised cholesterol activation model in which activation is driven not by saturation of membrane-cholesterol interactions but rather by bulk membrane remodeling that reduces membrane-cholesterol affinity.

  15. The Structural Basis of Cholesterol Accessibility in Membranes

    PubMed Central

    Olsen, Brett N.; Bielska, Agata A.; Lee, Tiffany; Daily, Michael D.; Covey, Douglas F.; Schlesinger, Paul H.; Baker, Nathan A.; Ory, Daniel S.

    2013-01-01

    Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes modulates ER membrane behavior. Previous studies have predominantly examined cholesterol availability in terms of binding to extramembrane acceptors, but have provided limited insight into the structural changes underlying cholesterol activation. In this study, we use both molecular dynamics simulations and experimental membrane systems to examine the behavior of cholesterol in membrane bilayers. We find that cholesterol depth within the bilayer provides a reasonable structural metric for cholesterol availability and that this is correlated with cholesterol-acceptor binding. Further, the distribution of cholesterol availability in our simulations is continuous rather than divided into distinct available and unavailable pools. This data provide support for a revised cholesterol activation model in which activation is driven not by saturation of membrane-cholesterol interactions but rather by bulk membrane remodeling that reduces membrane-cholesterol affinity. PMID:24138860

  16. 25-Hydroxycholesterol Increases the Availability of Cholesterol in Phospholipid Membranes

    SciTech Connect

    Olsen, Brett N.; Schlesinger, Paul H.; Ory, Daniel S.; Baker, Nathan A.

    2011-02-01

    Side-chain oxysterols are enzymatically generated oxidation products of cholesterol that serve a central role in mediating cholesterol homeostasis. Recent work has shown that side-chain oxysterols, such as 25-hydroxycholesterol (25-HC), alter membrane structure in very different ways from cholesterol, suggesting a possible mechanism for how these oxysterols regulate cholesterol homeostasis. Here we extend our previous work, using molecular dynamics simulations of 25-HC and cholesterol mixtures in 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayers to examine interactions between 25-HC and cholesterol in the same bilayer. When added to cholesterol-containing membranes, 25-HC causes larger changes in membrane structure than when added to cholesterol-free membranes, demonstrating interactions between the two sterols. We also find that the presence of 25-HC changes the position, orientation, and solvent accessibility of cholesterol, shifting it into the water interface and therefore its availability to external acceptors. This is consistent with experimental results showing that oxysterols can trigger cholesterol trafficking from the plasma membrane to the endoplasmic reticulum. These interactions provide a potential mechanism for 25-HC-mediated regulation of cholesterol trafficking and homeostasis through direct modulation of cholesterol availability.

  17. Cholesterol in myelin biogenesis and hypomyelinating disorders.

    PubMed

    Saher, Gesine; Stumpf, Sina Kristin

    2015-08-01

    The largest pool of free cholesterol in mammals resides in myelin membranes. Myelin facilitates rapid saltatory impulse propagation by electrical insulation of axons. This function is achieved by ensheathing axons with a tightly compacted stack of membranes. Cholesterol influences myelination at many steps, from the differentiation of myelinating glial cells, over the process of myelin membrane biogenesis, to the functionality of mature myelin. Cholesterol emerged as the only integral myelin component that is essential and rate-limiting for the development of myelin in the central and peripheral nervous system. Moreover, disorders that interfere with sterol synthesis or intracellular trafficking of cholesterol and other lipids cause hypomyelination and neurodegeneration. This review summarizes recent results on the roles of cholesterol in CNS myelin biogenesis in normal development and under different pathological conditions. This article is part of a Special Issue entitled Brain Lipids.

  18. Structure of Cholesterol in Lipid Rafts

    NASA Astrophysics Data System (ADS)

    Toppozini, Laura; Meinhardt, Sebastian; Armstrong, Clare L.; Yamani, Zahra; Kučerka, Norbert; Schmid, Friederike; Rheinstädter, Maikel C.

    2014-11-01

    Rafts, or functional domains, are transient nano-or mesoscopic structures in the plasma membrane and are thought to be essential for many cellular processes such as signal transduction, adhesion, trafficking, and lipid or protein sorting. Observations of these membrane heterogeneities have proven challenging, as they are thought to be both small and short lived. With a combination of coarse-grained molecular dynamics simulations and neutron diffraction using deuterium labeled cholesterol molecules, we observe raftlike structures and determine the ordering of the cholesterol molecules in binary cholesterol-containing lipid membranes. From coarse-grained computer simulations, heterogenous membranes structures were observed and characterized as small, ordered domains. Neutron diffraction was used to study the lateral structure of the cholesterol molecules. We find pairs of strongly bound cholesterol molecules in the liquid-disordered phase, in accordance with the umbrella model. Bragg peaks corresponding to ordering of the cholesterol molecules in the raftlike structures were observed and indexed by two different structures: a monoclinic structure of ordered cholesterol pairs of alternating direction in equilibrium with cholesterol plaques, i.e., triclinic cholesterol bilayers.

  19. Aspirin Prevention of Cholesterol Gallstone Formation in Prairie Dogs

    NASA Astrophysics Data System (ADS)

    Lee, Sum P.; Carey, Martin C.; Lamont, J. Thomas

    1981-03-01

    When prairie dogs (Cynomys ludovicianus) are fed a diet containing cholesterol, a marked increase in gallbladder mucin secretion parallels the evolution of cholesterol supersaturated bile. Gelation of mucin precedes the precipitation of cholesterol liquid and solid crystals and the development of gallstones. Aspirin given to prairie dogs inhibited mucin hypersecretion and gel accumulation and prevented gallstone formation without influencing the cholesterol content of supersaturated bile. This suggests that gallbladder mucin is a nucleation matrix for cholesterol gallstones.

  20. Peptide mediators of cholesterol efflux

    DOEpatents

    Bielicki, John K.; Johansson, Jan

    2013-04-09

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  1. Women and Cholesterol

    MedlinePlus

    ... Blood Pressure Tools & Resources Stroke More Women and Cholesterol Updated:Apr 1,2016 The female sex hormone ... Glossary Related Sites Nutrition Center My Life Check Cholesterol • Home • About Cholesterol • Why Cholesterol Matters • Understand Your ...

  2. Cholesterol IQ Quiz

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Cholesterol IQ Quiz Updated:Feb 2,2015 Begin the quiz Cholesterol • Home • About Cholesterol Introduction Good vs. Bad Cholesterol ...

  3. Membrane cholesterol modulates cochlear electromechanics.

    PubMed

    Brownell, William E; Jacob, Stefan; Hakizimana, Pierre; Ulfendahl, Mats; Fridberger, Anders

    2011-06-01

    Changing the concentration of cholesterol in the plasma membrane of isolated outer hair cells modulates electromotility and prestin-associated charge movement, suggesting that a similar manipulation would alter cochlear mechanics. We examined cochlear function before and after depletion of membrane cholesterol with methyl-β-cyclodextrin (MβCD) in an excised guinea pig temporal bone preparation. The mechanical response of the cochlear partition to acoustic and/or electrical stimulation was monitored using laser interferometry and time-resolved confocal microscopy. The electromechanical response in untreated preparations was asymmetric with greater displacements in response to positive currents. Exposure to MβCD increased the magnitude and asymmetry of the response, without changing the frequency tuning of sound-evoked mechanical responses or cochlear microphonic potentials. Sodium salicylate reversibly blocked the enhanced electromechanical response in cholesterol depleted preparations. The increase of sound-evoked vibrations during positive current injection was enhanced following MβCD in some preparations. Imaging was used to assess cellular integrity which remained unchanged after several hours of exposure to MβCD in several preparations. The enhanced electromechanical response reflects an increase in outer hair cell electromotility and may reveal features of cholesterol distribution and trafficking in outer hair cells. PMID:21373862

  4. Lipid rafts, cholesterol, and the brain

    PubMed Central

    Korade, Zeljka; Kenworthy, Anne K.

    2008-01-01

    Summary Lipid rafts are specialized membrane microdomains that serve as organizing centers for assembly of signaling molecules, influence membrane fluidity and trafficking of membrane proteins, and regulate different cellular processes such as neurotransmission and receptor trafficking. In this article, we provide an overview of current methods for studying lipid rafts and models for how lipid rafts might form and function. Next, we propose a potential mechanism for regulating lipid rafts in the brain via local control of cholesterol biosynthesis by neurotrophins and their receptors. Finally, we discuss evidence that altered cholesterol metabolism and/or lipid rafts play a critical role in the pathophysiology of multiple CNS disorders, including Smith-Lemli-Opitz syndrome, Huntington, Alzheimer's, and Niemman-Pick Type C diseases. PMID:18402986

  5. Like iron in the blood of the people: the requirement for heme trafficking in iron metabolism

    PubMed Central

    Korolnek, Tamara; Hamza, Iqbal

    2014-01-01

    Heme is an iron-containing porphyrin ring that serves as a prosthetic group in proteins that function in diverse metabolic pathways. Heme is also a major source of bioavailable iron in the human diet. While the synthesis of heme has been well-characterized, the pathways for heme trafficking remain poorly understood. It is likely that heme transport across membranes is highly regulated, as free heme is toxic to cells. This review outlines the requirement for heme delivery to various subcellular compartments as well as possible mechanisms for the mobilization of heme to these compartments. We also discuss how these trafficking pathways might function during physiological events involving inter- and intra-cellular mobilization of heme, including erythropoiesis, erythrophagocytosis, heme absorption in the gut, as well as heme transport pathways supporting embryonic development. Lastly, we aim to question the current dogma that heme, in toto, is not mobilized from one cell or tissue to another, outlining the evidence for these pathways and drawing parallels to other well-accepted paradigms for copper, iron, and cholesterol homeostasis. PMID:24926267

  6. Non-cholesterol sterols and cholesterol metabolism in sitosterolemia.

    PubMed

    Othman, Rgia A; Myrie, Semone B; Jones, Peter J H

    2013-12-01

    Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.

  7. Potential of BODIPY-cholesterol for analysis of cholesterol transport and diffusion in living cells.

    PubMed

    Wüstner, Daniel; Lund, Frederik W; Röhrl, Clemens; Stangl, Herbert

    2016-01-01

    Cholesterol is an abundant and important lipid component of cellular membranes. Analysis of cholesterol transport and diffusion in living cells is hampered by the technical challenge of designing suitable cholesterol probes which can be detected for example by optical microscopy. One strategy is to use intrinsically fluorescent sterols, as dehydroergosterol (DHE), having minimal chemical alteration compared to cholesterol but giving low fluorescence signals in the UV region of the spectrum. Alternatively, one can use dye-tagged cholesterol analogs and in particular BODIPY-cholesterol (BChol), whose synthesis and initial characterization was pioneered by Robert Bittman. Here, we give a general overview of the properties and applications but also limitations of BODIPY-tagged cholesterol probes for analyzing intracellular cholesterol trafficking. We describe our own experiences and collaborative efforts with Bob Bittman for studying diffusion in the plasma membrane (PM) and uptake of BChol in a quantitative manner. For that purpose, we used a variety of fluorescence approaches including fluorescence correlation spectroscopy and its imaging variants, fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP). We also describe pulse-chase studies from the PM using BChol in direct comparison to DHE. Based on the gathered imaging data, we present a two-step kinetic model for sterol transport between PM and recycling endosomes. In addition, we highlight the suitability of BChol for determining transport of lipoprotein-derived sterol using electron microscopy (EM) and show that this approach ideally complements fluorescence studies.

  8. All about Cholesterol

    MedlinePlus

    ... are several kinds of fats in your blood. • LDL cholesterol is sometimes called “bad” cholesterol. It can narrow ... medicine to manage blood fats. They help lower LDL cholesterol. They also help lower your risk for a ...

  9. Interactions between Ether Phospholipids and Cholesterol as Determined by Scattering and Molecular Dynamics Simulations

    SciTech Connect

    Pan, Jianjun; Cheng, Xiaolin; Heberle, Frederick A; Mostofian, Barmak; Kucerka, Norbert; Drazba, Paul; Katsaras, John

    2012-01-01

    Cholesterol and ether lipids are ubiquitous in mammalian cell membranes, and their interactions are crucial in ether lipid mediated cholesterol trafficking. We report on cholesterol s molecular interactions with ether lipids as determined using a combination of small-angle neutron and Xray scattering, and all-atom molecular dynamics (MD) simulations. A scattering density profile model for an ether lipid bilayer was developed using MD simulations, which was then used to simultaneously fit the different experimental scattering data. From analysis of the data the various bilayer structural parameters were obtained. Surface area constrained MD simulations were also performed to reproduce the experimental data. This iterative analysis approach resulted in good agreement between the experimental and simulated form factors. The molecular interactions taking place between cholesterol and ether lipids were then determined from the validated MD simulations. We found that in ether membranes cholesterol primarily hydrogen bonds with the lipid headgroup phosphate oxygen, while in their ester membrane counterparts cholesterol hydrogen bonds with the backbone ester carbonyls. This different mode of interaction between ether lipids and cholesterol induces cholesterol to reside closer to the bilayer surface, dehydrating the headgroup s phosphate moiety. Moreover, the three-dimensional lipid chain spatial density distribution around cholesterol indicates anisotropic chain packing, causing cholesterol to tilt. These insights lend a better understanding of ether lipid-mediated cholesterol trafficking and the roles that the different lipid species have in determining the structural and dynamical properties of membrane associated biomolecules.

  10. microRNAs: a connection between cholesterol metabolism and neurodegeneration

    PubMed Central

    Goedeke, Leigh; Fernández-Hernando, Carlos

    2014-01-01

    Dysregulation of cholesterol metabolism in the brain has been associated with many neurodegenerative disorders such as Alzheimer’s disease, Niemann-Pick type C disease, Smith-Lemli-Opitz syndrome, Hungtington’s disease and Parkinson’s disease. Specifically, genes involved in cholesterol biosynthesis (24-dehydrocholesterol reductase, DHCR24) and cholesterol efflux (ATP-binding cassete transporter, ABCA1, and apolipoprotein E, APOE) have been associated with developing Alzheimer’s disease. Indeed, APOE was the first gene variation found to increase the risk of Alzheimer’s disease and remains the risk gene with the greatest known impact. Mutations in another cholesterol biosynthetic gene, 7-dehydrocholesterol reductase (DHCR7), cause Smith-Lemli-Opitz syndrome and impairment in cellular cholesterol trafficking caused by mutations in the NPC1 protein results in Niemann-Pick type C disease. Taken together, these findings provide strong evidence that cholesterol metabolism needs to be controlled at very tight levels in the brain. Recent studies have implicated microRNAs (miRNAs) as novel regulators of cholesterol metabolism in several tissues. These small non-coding RNAs regulate gene expression at the post-transcriptional level by either suppressing translation or inducing mRNA degradation. This review article focuses on how cholesterol homeostasis is regulated by miRNAs and their potential implication in several neurodegenerative disorders, such as Alzheimer’s disease. Finally, we also discuss how antagonizing miRNA expression could be a potential therapy for treating cholesterol related diseases. PMID:24907491

  11. MicroRNAs: a connection between cholesterol metabolism and neurodegeneration.

    PubMed

    Goedeke, Leigh; Fernández-Hernando, Carlos

    2014-12-01

    Dysregulation of cholesterol metabolism in the brain has been associated with many neurodegenerative disorders such as Alzheimer's disease, Niemann-Pick type C disease, Smith-Lemli-Opitz syndrome, Hungtington's disease and Parkinson's disease. Specifically, genes involved in cholesterol biosynthesis (24-dehydrocholesterol reductase, DHCR24) and cholesterol efflux (ATP-binding cassete transporter, ABCA1, and apolipoprotein E, APOE) have been associated with developing Alzheimer's disease. Indeed, APOE was the first gene variation found to increase the risk of Alzheimer's disease and remains the risk gene with the greatest known impact. Mutations in another cholesterol biosynthetic gene, 7-dehydrocholesterol reductase (DHCR7), cause Smith-Lemli-Opitz syndrome and impairment in cellular cholesterol trafficking caused by mutations in the NPC1 protein results in Niemann-Pick type C disease. Taken together, these findings provide strong evidence that cholesterol metabolism needs to be controlled at very tight levels in the brain. Recent studies have implicated microRNAs (miRNAs) as novel regulators of cholesterol metabolism in several tissues. These small non-coding RNAs regulate gene expression at the post-transcriptional level by either suppressing translation or inducing mRNA degradation. This review article focuses on how cholesterol homeostasis is regulated by miRNAs and their potential implication in several neurodegenerative disorders, such as Alzheimer's disease. Finally, we also discuss how antagonizing miRNA expression could be a potential therapy for treating cholesterol related diseases.

  12. Lysosomal Trafficking Regulator (LYST).

    PubMed

    Ji, Xiaojie; Chang, Bo; Naggert, Jürgen K; Nishina, Patsy M

    2016-01-01

    Regulation of vesicle trafficking to lysosomes and lysosome-related organelles (LROs) as well as regulation of the size of these organelles are critical to maintain their functions. Disruption of the lysosomal trafficking regulator (LYST) results in Chediak-Higashi syndrome (CHS), a rare autosomal recessive disorder characterized by oculocutaneous albinism, prolonged bleeding, severe immunodeficiency, recurrent bacterial infection, neurologic dysfunction and hemophagocytic lympohistiocytosis (HLH). The classic diagnostic feature of the syndrome is enlarged LROs in all cell types, including lysosomes, melanosomes, cytolytic granules and platelet dense bodies. The most striking CHS ocular pathology observed is an enlargement of melanosomes in the retinal pigment epithelium (RPE), which leads to aberrant distribution of eye pigmentation, and results in photophobia and decreased visual acuity. Understanding the molecular function of LYST and identification of its interacting partners may provide therapeutic targets for CHS and other diseases associated with the regulation of LRO size and/or vesicle trafficking, such as asthma, urticaria and Leishmania amazonensis infections. PMID:26427484

  13. UNC-108/Rab2 Regulates Postendocytic Trafficking in Caenorhabditis elegans

    PubMed Central

    Chun, Denise K.; McEwen, Jason M.; Burbea, Michelle

    2008-01-01

    After endocytosis, membrane proteins are often sorted between two alternative pathways: a recycling pathway and a degradation pathway. Relatively little is known about how trafficking through these alternative pathways is differentially regulated. Here, we identify UNC-108/Rab2 as a regulator of postendocytic trafficking in both neurons and coelomocytes. Mutations in the Caenorhabditis elegans Rab2 gene unc-108, caused the green fluorescent protein (GFP)-tagged glutamate receptor GLR-1 (GLR-1::GFP) to accumulate in the ventral cord and in neuronal cell bodies. In neuronal cell bodies of unc-108/Rab2 mutants, GLR-1::GFP was found in tubulovesicular structures that colocalized with markers for early and recycling endosomes, including Syntaxin-13 and Rab8. GFP-tagged Syntaxin-13 also accumulated in the ventral cord of unc-108/Rab2 mutants. UNC-108/Rab2 was not required for ubiquitin-mediated sorting of GLR-1::GFP into the multivesicular body (MVB) degradation pathway. Mutations disrupting the MVB pathway and unc-108/Rab2 mutations had additive effects on GLR-1::GFP levels in the ventral cord. In coelomocytes, postendocytic trafficking of the marker Texas Red-bovine serum albumin was delayed. These results demonstrate that UNC-108/Rab2 regulates postendocytic trafficking, most likely at the level of early or recycling endosomes, and that UNC-108/Rab2 and the MVB pathway define alternative postendocytic trafficking mechanisms that operate in parallel. These results define a new function for Rab2 in protein trafficking. PMID:18434599

  14. Health implications of human trafficking.

    PubMed

    Richards, Tiffany A

    2014-01-01

    Freedom is arguably the most cherished right in the United States. But each year, approximately 14,500 to 17,500 women, men and children are trafficked into the United States for the purposes of forced labor or sexual exploitation. Human trafficking has significant effects on both physical and mental health. This article describes the features of human trafficking, its physical and mental health effects and the vital role nurses can play in providing care to this vulnerable population. PMID:24750655

  15. Health implications of human trafficking.

    PubMed

    Richards, Tiffany A

    2014-01-01

    Freedom is arguably the most cherished right in the United States. But each year, approximately 14,500 to 17,500 women, men and children are trafficked into the United States for the purposes of forced labor or sexual exploitation. Human trafficking has significant effects on both physical and mental health. This article describes the features of human trafficking, its physical and mental health effects and the vital role nurses can play in providing care to this vulnerable population.

  16. Cholesterol testing and results

    MedlinePlus

    ... VLDL cholesterol) Lipoproteins are made of fat and protein. They carry cholesterol, triglycerides, and other fats, called ... Pencina MJ, Navar-Boggan AM, D'Agostino RB Sr, Williams K, Neely B, Sniderman AD, Peterson ED. ...

  17. Cholesterol and Plants

    ERIC Educational Resources Information Center

    Behrman, E. J.; Gopalan, Venkat

    2005-01-01

    There is a widespread belief among the public and even among chemist that plants do not contain cholesterol. This wrong belief is the result of the fact that plants generally contain only small quantities of cholesterol and that analytical methods for the detection of cholesterol in this range were not developed until recently.

  18. Antibodies to cholesterol.

    PubMed Central

    Swartz, G M; Gentry, M K; Amende, L M; Blanchette-Mackie, E J; Alving, C R

    1988-01-01

    Cholesterol-dependent complement activation has been proposed as a factor that might influence the pathogenesis of atherosclerosis. Although antibodies to cholesterol conjugates have been reported, cholesterol is widely regarded as a poorly immunogenic substance. Monoclonal IgM complement-fixing antibodies to cholesterol were obtained in the present study after immunizing mice with liposomes containing high amounts of cholesterol (71 mol % relative to phosphatidylcholine) and lipid A as an adjuvant. Clones were selected for the ability of secreted antibodies to react with liposomes containing 71% cholesterol but not with liposomes containing 43% cholesterol. The antibodies also reacted with crystalline cholesterol in a solid-phase enzyme-linked immunosorbent assay. Binding of monoclonal antibodies to the surface of crystalline cholesterol was demonstrated by electron microscopy by utilizing a second antibody (anti-IgM) labeled with colloidal gold. The immunization period required to induce monoclonal antibodies was very short (3 days) and a high fraction of the hybrid cells (at least 70%) were secreting detectable antibodies to cholesterol. The results demonstrate that cholesterol can be a highly immunogenic molecule and that complement-fixing antibodies to cholesterol can be readily obtained. Images PMID:3162316

  19. Avoiding Christmas cholesterol.

    PubMed

    1991-12-01

    Judging from your response to our September feature on cholesterol testing providing dietary advice has become of paramount importance to OHNs. The Flora Project for Heart Disease Prevention offers information on the risk factors of high cholesterol and has become a major noninstitutional authority on coronary heart disease. With Yuletide in sight The Flora Project offers advice on a cholesterol-clear Christmas.

  20. Potent and selective mediators of cholesterol efflux

    DOEpatents

    Bielicki, John K; Johansson, Jan

    2015-03-24

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  1. Mitochondria, cholesterol and cancer cell metabolism.

    PubMed

    Ribas, Vicent; García-Ruiz, Carmen; Fernández-Checa, José C

    2016-12-01

    Given the role of mitochondria in oxygen consumption, metabolism and cell death regulation, alterations in mitochondrial function or dysregulation of cell death pathways contribute to the genesis and progression of cancer. Cancer cells exhibit an array of metabolic transformations induced by mutations leading to gain-of-function of oncogenes and loss-of-function of tumor suppressor genes that include increased glucose consumption, reduced mitochondrial respiration, increased reactive oxygen species generation and cell death resistance, all of which ensure cancer progression. Cholesterol metabolism is disturbed in cancer cells and supports uncontrolled cell growth. In particular, the accumulation of cholesterol in mitochondria emerges as a molecular component that orchestrates some of these metabolic alterations in cancer cells by impairing mitochondrial function. As a consequence, mitochondrial cholesterol loading in cancer cells may contribute, in part, to the Warburg effect stimulating aerobic glycolysis to meet the energetic demand of proliferating cells, while protecting cancer cells against mitochondrial apoptosis due to changes in mitochondrial membrane dynamics. Further understanding the complexity in the metabolic alterations of cancer cells, mediated largely through alterations in mitochondrial function, may pave the way to identify more efficient strategies for cancer treatment involving the use of small molecules targeting mitochondria, cholesterol homeostasis/trafficking and specific metabolic pathways. PMID:27455839

  2. 31 CFR 536.311 - Narcotics trafficking.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Narcotics trafficking. 536.311 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING SANCTIONS REGULATIONS General Definitions § 536.311 Narcotics trafficking. The term narcotics trafficking means any activity...

  3. 31 CFR 536.311 - Narcotics trafficking.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Narcotics trafficking. 536.311 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING SANCTIONS REGULATIONS General Definitions § 536.311 Narcotics trafficking. The term narcotics trafficking means any activity...

  4. 31 CFR 536.311 - Narcotics trafficking.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Narcotics trafficking. 536.311 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING SANCTIONS REGULATIONS General Definitions § 536.311 Narcotics trafficking. The term narcotics trafficking means any activity...

  5. 31 CFR 536.311 - Narcotics trafficking.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Narcotics trafficking. 536.311 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING SANCTIONS REGULATIONS General Definitions § 536.311 Narcotics trafficking. The term narcotics trafficking means any activity...

  6. 31 CFR 536.311 - Narcotics trafficking.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Narcotics trafficking. 536.311... OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING SANCTIONS REGULATIONS General Definitions § 536.311 Narcotics trafficking. The term narcotics trafficking means any...

  7. Assessing Cholesterol Storage in Live Cells and C. elegans by Stimulated Raman Scattering Imaging of Phenyl-Diyne Cholesterol

    NASA Astrophysics Data System (ADS)

    Lee, Hyeon Jeong; Zhang, Wandi; Zhang, Delong; Yang, Yang; Liu, Bin; Barker, Eric L.; Buhman, Kimberly K.; Slipchenko, Lyudmila V.; Dai, Mingji; Cheng, Ji-Xin

    2015-01-01

    We report a cholesterol imaging method using rationally synthesized phenyl-diyne cholesterol (PhDY-Chol) and stimulated Raman scattering (SRS) microscope. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C = O stretching mode. SRS microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living CHO cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In live C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, our work demonstrates an enabling platform for study of cholesterol storage and trafficking in living cells and vital organisms.

  8. Assessing Cholesterol Storage in Live Cells and C. elegans by Stimulated Raman Scattering Imaging of Phenyl-Diyne Cholesterol

    PubMed Central

    Lee, Hyeon Jeong; Zhang, Wandi; Zhang, Delong; Yang, Yang; Liu, Bin; Barker, Eric L.; Buhman, Kimberly K.; Slipchenko, Lyudmila V.; Dai, Mingji; Cheng, Ji-Xin

    2015-01-01

    We report a cholesterol imaging method using rationally synthesized phenyl-diyne cholesterol (PhDY-Chol) and stimulated Raman scattering (SRS) microscope. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C = O stretching mode. SRS microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living CHO cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In live C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, our work demonstrates an enabling platform for study of cholesterol storage and trafficking in living cells and vital organisms. PMID:25608867

  9. Illicit Trafficking of Natural Radionuclides

    SciTech Connect

    Friedrich, Steinhaeusler; Lyudmila, Zaitseva

    2008-08-07

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium (<20% U 235) or highly enriched uranium (>20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces.

  10. Illicit Trafficking of Natural Radionuclides

    NASA Astrophysics Data System (ADS)

    Friedrich, Steinhäusler; Lyudmila, Zaitseva

    2008-08-01

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium (<20% U 235) or highly enriched uranium (>20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces.

  11. Sex trafficking in South Asia.

    PubMed

    Huda, S

    2006-09-01

    Economic and social inequalities and political conflicts have led to the movement of persons within each country and across the borders in South Asia. Globalization has encouraged free mobility of capital, technology, experts and sex tourism. Illiteracy, dependency, violence, social stigma, cultural stereotypes, gender disparity and endemic poverty, among other factors, place women and children in powerless, non-negotiable situations that have contributed to the emergence and breeding of the cavernous problem of sex trafficking in the entire region. This alarming spread of sex trafficking has fuelled the spread of HIV infection in South Asia, posing a unique and serious threat to community health, poverty alleviation and other crucial aspects of human development. Although the SAARC (South Asian Association for Regional Cooperation) Convention on Trafficking in Women and Children has been an important breakthrough, most of the countries in the region do not have anti-trafficking legislation or means to protect the victims. Countries of the region should make a concerted effort to treat trafficking victims as "victims" of human rights violations in all anti-trafficking strategies and actions.

  12. Home-Use Tests - Cholesterol

    MedlinePlus

    ... this test does: This is a home-use test kit to measure total cholesterol. What cholesterol is: Cholesterol is a fat (lipid) in your blood. High-density lipoprotein (HDL) ("good" cholesterol) helps protect your heart, but low-density lipoprotein (LDL) ("bad" cholesterol) can clog the arteries of your ...

  13. To discuss illicit nuclear trafficking

    SciTech Connect

    Balatsky, Galya I; Severe, William R; Wallace, Richard K

    2010-01-01

    The Illicit nuclear trafficking panel was conducted at the 4th Annual INMM workshop on Reducing the Risk from Radioactive and Nuclear Materials on February 2-3, 2010 in Washington DC. While the workshop occurred prior to the Nuclear Security Summit, April 12-13 2010 in Washington DC, some of the summit issues were raised during the workshop. The Communique of the Washington Nuclear Security Summit stated that 'Nuclear terrorism is one of the most challenging threats to international security, and strong nuclear security measures are the most effective means to prevent terrorists, criminals, or other unauthorized actors from acquiring nuclear materials.' The Illicit Trafficking panel is one means to strengthen nuclear security and cooperation at bilateral, regional and multilateral levels. Such a panel promotes nuclear security culture through technology development, human resources development, education and training. It is a tool which stresses the importance of international cooperation and coordination of assistance to improve efforts to prevent and respond to incidents of illicit nuclear trafficking. Illicit trafficking panel included representatives from US government, an international organization (IAEA), private industry and a non-governmental organization to discuss illicit nuclear trafficking issues. The focus of discussions was on best practices and challenges for addressing illicit nuclear trafficking. Terrorism connection. Workshop discussions pointed out the identification of terrorist connections with several trafficking incidents. Several trafficking cases involved real buyers (as opposed to undercover law enforcement agents) and there have been reports identifying individuals associated with terrorist organizations as prospective plutonium buyers. Some specific groups have been identified that consistently search for materials to buy on the black market, but no criminal groups were identified that specialize in nuclear materials or isotope smuggling

  14. HDL and cholesterol handling in the brain.

    PubMed

    Vitali, Cecilia; Wellington, Cheryl L; Calabresi, Laura

    2014-08-01

    Cholesterol is an essential component of both the peripheral nervous system and central nervous system (CNS) of mammals. Brain cholesterol is synthesized in situ by astrocytes and oligodendrocytes and is almost completely isolated from other pools of cholesterol in the body, but a small fraction can be taken up from the circulation as 27-hydroxycholesterol, or via the scavenger receptor class B type I. Glial cells synthesize native high-density lipoprotein (HDL)-like particles, which are remodelled by enzymes and lipid transfer proteins, presumably as it occurs in plasma. The major apolipoprotein constituent of HDL in the CNS is apolipoprotein E, which is produced by astrocytes and microglia. Apolipoprotein A-I, the major protein component of plasma HDL, is not synthesized in the CNS, but can enter and become a component of CNS lipoproteins. Low HDL-C levels have been shown to be associated with cognitive impairment and various neurodegenerative diseases. On the contrary, no clear association with brain disorders has been shown in genetic HDL defects, with the exception of Tangier disease. Mutations in a wide variety of lipid handling genes can result in human diseases, often with a neuronal phenotype caused by dysfunctional intracellular lipid trafficking.

  15. Improved Coarse-Grained Modeling of Cholesterol-Containing Lipid Bilayers

    PubMed Central

    2015-01-01

    Cholesterol trafficking, which is an essential function in mammalian cells, is intimately connected to molecular-scale interactions through cholesterol modulation of membrane structure and dynamics and interaction with membrane receptors. Since these effects of cholesterol occur on micro- to millisecond time scales, it is essential to develop accurate coarse-grained simulation models that can reach these time scales. Cholesterol has been shown experimentally to thicken the membrane and increase phospholipid tail order between 0 and 40% cholesterol, above which these effects plateau or slightly decrease. Here, we showed that the published MARTINI coarse-grained force-field for phospholipid (POPC) and cholesterol fails to capture these effects. Using reference atomistic simulations, we systematically modified POPC and cholesterol bonded parameters in MARTINI to improve its performance. We showed that the corrections to pseudobond angles between glycerol and the lipid tails and around the oleoyl double bond particle (the “angle-corrected model”) slightly improves the agreement of MARTINI with experimentally measured thermal, elastic, and dynamic properties of POPC membranes. The angle-corrected model improves prediction of the thickening and ordering effects up to 40% cholesterol but overestimates these effects at higher cholesterol concentration. In accordance with prior work that showed the cholesterol rough face methyl groups are important for limiting cholesterol self-association, we revised the coarse-grained representation of these methyl groups to better match cholesterol-cholesterol radial distribution functions from atomistic simulations. In addition, by using a finer-grained representation of the branched cholesterol tail than MARTINI, we improved predictions of lipid tail order and bilayer thickness across a wide range of concentrations. Finally, transferability testing shows that a model incorporating our revised parameters into DOPC outperforms other

  16. Children and Cholesterol

    MedlinePlus

    ... a coronary artery procedure; or who suffered a heart attack or sudden cardiac death before age 55. Those with a parent who has a history of high total cholesterol levels (240 mg/dL or higher). Talk to your child’s pediatrician ... Risk Calculator Printable Cholesterol Information Sheets Heart360 Health ...

  17. Cholesterol and Affective Morbidity

    PubMed Central

    Fiedorowicz, Jess G.; Palagummi, Narasimha M.; Behrendtsen, Ole; Coryell, William H.

    2009-01-01

    Depression and mania have been linked with low cholesterol though there has been limited prospective study of cholesterol and subsequent course of affective illness. We studied the relationship between fasting total cholesterol and subsequent depressive and manic symptoms. A total of 131 participants from a prospective cohort study were identified as having had a fasting total cholesterol evaluation at intake. Participants were predominantly inpatients at index visit and were followed for a median of 20 and up to 25 years. Cholesterol was modeled with age, gender, and index use of a mood stabilizer in linear regression to assess its influence on subsequent depressive symptom burden in participants with unipolar disorder as well as depressive and manic symptom burden in participants with bipolar disorder. Among bipolar participants (N=65), low cholesterol predicted a higher proportion of follow-up weeks with manic, but not depressive symptoms. Cholesterol did not appear to predict depressive symptom burden among participants with unipolar depression (N=66). Lower cholesterol levels may predispose individuals with bipolar disorder to a greater burden of manic symptomatology and may provide some insight into the underlying neurobiology. PMID:19969372

  18. Cholesterol and Your Child

    MedlinePlus

    ... traveling together are called lipoproteins . Two kinds — low-density lipoprotein (LDL) and high-density lipoprotein (HDL) — are the ones that most of us have heard about. Low-density lipoproteins , or "bad cholesterol," are the primary cholesterol ...

  19. Electrochemical oxidation of cholesterol

    PubMed Central

    2015-01-01

    Summary Indirect cholesterol electrochemical oxidation in the presence of various mediators leads to electrophilic addition to the double bond, oxidation at the allylic position, oxidation of the hydroxy group, or functionalization of the side chain. Recent studies have proven that direct electrochemical oxidation of cholesterol is also possible and affords different products depending on the reaction conditions. PMID:25977713

  20. Complementary probes reveal that phosphatidylserine is required for the proper transbilayer distribution of cholesterol.

    PubMed

    Maekawa, Masashi; Fairn, Gregory D

    2015-04-01

    Cholesterol is an essential component of metazoan cellular membranes and it helps to maintain the structural integrity and fluidity of the plasma membrane. Here, we developed a cholesterol biosensor, termed D4H, based on the fourth domain of Clostridium perfringens theta-toxin, which recognizes cholesterol in the cytosolic leaflet of the plasma membrane and organelles. The D4H probe disassociates from the plasma membrane upon cholesterol extraction and after perturbations in cellular cholesterol trafficking. When used in combination with a recombinant version of the biosensor, we show that plasmalemmal phosphatidylserine is essential for retaining cholesterol in the cytosolic leaflet of the plasma membrane. In vitro experiments reveal that 1-stearoy-2-oleoyl phosphatidylserine can induce phase separation in cholesterol-containing lipid bilayers and shield cholesterol from cholesterol oxidase. Finally, the altered transbilayer distribution of cholesterol causes flotillin-1 to relocalize to endocytic organelles. This probe should be useful in the future to study pools of cholesterol in the cytosolic leaflet of the plasma membrane and organelles. PMID:25663704

  1. Complementary probes reveal that phosphatidylserine is required for the proper transbilayer distribution of cholesterol.

    PubMed

    Maekawa, Masashi; Fairn, Gregory D

    2015-04-01

    Cholesterol is an essential component of metazoan cellular membranes and it helps to maintain the structural integrity and fluidity of the plasma membrane. Here, we developed a cholesterol biosensor, termed D4H, based on the fourth domain of Clostridium perfringens theta-toxin, which recognizes cholesterol in the cytosolic leaflet of the plasma membrane and organelles. The D4H probe disassociates from the plasma membrane upon cholesterol extraction and after perturbations in cellular cholesterol trafficking. When used in combination with a recombinant version of the biosensor, we show that plasmalemmal phosphatidylserine is essential for retaining cholesterol in the cytosolic leaflet of the plasma membrane. In vitro experiments reveal that 1-stearoy-2-oleoyl phosphatidylserine can induce phase separation in cholesterol-containing lipid bilayers and shield cholesterol from cholesterol oxidase. Finally, the altered transbilayer distribution of cholesterol causes flotillin-1 to relocalize to endocytic organelles. This probe should be useful in the future to study pools of cholesterol in the cytosolic leaflet of the plasma membrane and organelles.

  2. What Your Cholesterol Levels Mean

    MedlinePlus

    ... Pressure Tools & Resources Stroke More What Your Cholesterol Levels Mean Updated:Aug 17,2016 How’s your cholesterol? Time to get it checked! Keeping your cholesterol levels healthy is a great way to keep your ...

  3. Serum cholesterol selectively regulates glucocorticoid sensitivity through activation of JNK.

    PubMed

    Yang, Nan; Caratti, Giorgio; Ince, Louise M; Poolman, Toryn M; Trebble, Peter J; Holt, Cathy M; Ray, David W; Matthews, Laura C

    2014-11-01

    Glucocorticoids (Gc) are potent anti-inflammatory agents with wide clinical application. We have previously shown that increased serum concentration significantly attenuates regulation of a simple Gc-responsive reporter. We now find that glucocorticoid receptor (GR) regulation of some endogenous transactivated but not transrepressed genes is impaired, suggesting template specificity. Serum did not directly affect GR expression, activity or trafficking, implicating GR crosstalk with other signalling pathways. Indeed, a JNK inhibitor completely abolished the serum effect. We identified the Gc modulating serum component as cholesterol. Cholesterol loading mimicked the serum effect, which was readily reversed by JNK inhibition. Chelation of serum cholesterol with methyl-β-cyclodextrin or inhibition of cellular cholesterol synthesis with simvastatin potentiated the Gc response. To explore the effect in vivo we used ApoE(-/-) mice, a model of hypercholesterolaemia. Consistent with our in vitro studies, we find no impact of elevated cholesterol on the expression of GR, or on the hypothalamic-pituitary-adrenal axis, measured by dexamethasone suppression test. Instead we find selective Gc resistance on some hepatic target genes in ApoE(-/-) mice. Therefore, we have discovered an unexpected role for cholesterol as a selective modulator of Gc action in vivo. Taken together these findings reveal a new environmental constraint on Gc action with relevance to both inflammation and cancer.

  4. Cholesterol and Ion Channels

    PubMed Central

    Levitan, Irena; Fang, Yun; Rosenhouse-Dantsker, Avia; Romanenko, Victor

    2010-01-01

    A variety of ion channels, including members of all major ion channel families, have been shown to be regulated by changes in the level of membrane cholesterol and partition into cholesterol-rich membrane domains. In general, several types of cholesterol effects have been described. The most common effect is suppression of channel activity by an increase in membrane cholesterol, an effect that was described for several types of inwardly-rectifying K+ channels, voltage-gated K+ channels, Ca+2 sensitive K+ channels, voltage-gated Na+ channels, N-type voltage-gated Ca+2 channels and volume-regulated anion channels. In contrast, several types of ion channels, such as epithelial amiloride-sensitive Na+ channels and Transient Receptor Potential channels, as well as some of the types of inwardly-rectifying and voltage-gated K+ channels were shown to be inhibited by cholesterol depletion. Cholesterol was also shown to alter the kinetic properties and current-voltage dependence of several voltage-gated channels. Finally, maintaining membrane cholesterol level is required for coupling ion channels to signalling cascades. In terms of the mechanisms, three general mechanisms have been proposed: (i) specific interactions between cholesterol and the channel protein, (ii) changes in the physical properties of the membrane bilayer and (iii) maintaining the scaffolds for protein-protein interactions. The goal of this review is to describe systematically the role of cholesterol in regulation of the major types of ion channels and to discuss these effects in the context of the models proposed. PMID:20213557

  5. Trafficking: a perspective from Asia.

    PubMed

    Skeldon, R

    2000-01-01

    The main theme of this article is market development and trafficking as a business. It touches upon most of the aspects of the phenomenon, which have been encountered elsewhere, and translates them into the relatively unfamiliar context of many of the Asian and South-East Asian economies. Equally, the literature cited is also probably unfamiliar. Themes touched upon include democratization, inter-state relations, human rights, and scale and perspectives, together with the problems of definitions, theory, and the reliability of data. The directions and characteristics of trafficking flows together with routes and border control are also considered. Coordinated official responses to criminality and criminal organizations, as well as to trafficked individuals, are beginning to emerge. There is a note of caution sounded that contextual and cultural perspectives, particularly on sex workers, must be viewed somewhat differently to those in Western societies. The article concludes that as long as countries in Asia maintain their policies of restrictive immigration, trafficking can be expected to continue and almost certainly increase. This is because accelerating development creates demand for labor at various skill levels and because even in times of recession migrants and brokers will seek to side-step attempts to expel immigrants and restrict access to labor markets. The elimination of trafficking is unlikely to be realistically achieved through legislation and declarations of intent but by improvements in the socioeconomic status of the population.

  6. Trafficking in persons: a health concern?

    PubMed

    Zimmerman, Cathy; Kiss, Ligia; Houssain, Mazeda; Watts, Charlotte

    2009-01-01

    Human trafficking is a phenomenon that has now been documented in most regions in the world. Although trafficking of women and girls for sexual exploitation is the most commonly recognised form of trafficking, it is widely acknowledged that human trafficking also involves men, women and children who are trafficked for various forms of labour exploitation and into other abusive circumstances. Despite the violence and harm inherent in most trafficking situations, there remains extremely little evidence on the individual and public health implications of any form of human trafficking. The Brazilian government has recently launched a national plan to combat human trafficking. However, because the health risks associated with human trafficking have not been well-recognised or documented, there is extremely limited reliable data on the health needs of trafficked persons to inform policy and practices.. Brazilian policy-makers and service providers should be encouraged to learn about the likely range of health impacts of trafficking, and incorporate this into anti-trafficking protection and response strategies. As well as prevention activities, the government, international and local organisations should work together with the public health research community to study the health needs of trafficked persons and explore opportunities to provide safe and appropriate services to victims in need of care. PMID:19721944

  7. Dietary Fat and Cholesterol

    MedlinePlus

    ... Gynecology Medical Conditions Nutrition & Fitness Emotional Health Dietary Fat and Cholesterol Posted under Health Guides . Updated 23 ... warm What are the different types of dietary fat? The four main types of fat found in ...

  8. Get Your Cholesterol Checked

    MedlinePlus

    ... is checked with a blood test called a lipid profile. During the test, a nurse will take ... blood tests that can check cholesterol, but a lipid profile gives the most information. Find out more ...

  9. High Blood Cholesterol

    MedlinePlus

    ... of cholesterol is called plaque. Plaque Buildup Can Lead to… Click for more information Artherosclerosis. Over time, ... disease (CHD). Angina. The buildup of plaque can lead to chest pain called angina. Angina is a ...

  10. Common Misconceptions about Cholesterol

    MedlinePlus

    ... most (and preferably all) days; and stressing the importance of avoiding tobacco products. Learn more about cholesterol ... Privacy Policy Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Low Blood Pressure ...

  11. Cholesterol and Statins

    MedlinePlus

    ... the liver makes ldl & hdl In the liver, triglycerides, cholesterol, and proteins form together to make LDL ... This is especially important for individuals with high triglyceride and/or low HDL levels who are overweight ...

  12. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  13. Understanding human trafficking in the United States.

    PubMed

    Logan, T K; Walker, Robert; Hunt, Gretchen

    2009-01-01

    The topic of modern-day slavery or human trafficking has received increased media and national attention. However, to date there has been limited research on the nature and scope of human trafficking in the United States. This article describes and synthesizes nine reports that assess the U.S. service organizations' legal representative knowledge of, and experience with, human trafficking cases, as well as information from actual cases and media reports. This article has five main goals: (a) to define what human trafficking is, and is not; (b) to describe factors identified as contributing to vulnerability to being trafficked and keeping a person entrapped in the situation; (c) to examine how the crime of human trafficking differs from other kinds of crimes in the United States; (d) to explore how human trafficking victims are identified; and, (e) to provide recommendations to better address human trafficking in the United States.

  14. Understanding human trafficking in the United States.

    PubMed

    Logan, T K; Walker, Robert; Hunt, Gretchen

    2009-01-01

    The topic of modern-day slavery or human trafficking has received increased media and national attention. However, to date there has been limited research on the nature and scope of human trafficking in the United States. This article describes and synthesizes nine reports that assess the U.S. service organizations' legal representative knowledge of, and experience with, human trafficking cases, as well as information from actual cases and media reports. This article has five main goals: (a) to define what human trafficking is, and is not; (b) to describe factors identified as contributing to vulnerability to being trafficked and keeping a person entrapped in the situation; (c) to examine how the crime of human trafficking differs from other kinds of crimes in the United States; (d) to explore how human trafficking victims are identified; and, (e) to provide recommendations to better address human trafficking in the United States. PMID:19056686

  15. Cholesterol-dependent balance between evoked and spontaneous synaptic vesicle recycling

    PubMed Central

    Wasser, Catherine R; Ertunc, Mert; Liu, Xinran; Kavalali, Ege T

    2007-01-01

    Cholesterol is a prominent component of nerve terminals. To examine cholesterol's role in central neurotransmission, we treated hippocampal cultures with methyl-β-cyclodextrin, which reversibly binds cholesterol, or mevastatin, an inhibitor of cholesterol biosynthesis, to deplete cholesterol. We also used hippocampal cultures from Niemann-Pick type C1-deficient mice defective in intracellular cholesterol trafficking. These conditions revealed an augmentation in spontaneous neurotransmission detected electrically and an increase in spontaneous vesicle endocytosis judged by horseradish peroxidase uptake after cholesterol depletion by methyl-β-cyclodextrin. In contrast, responses evoked by action potentials and hypertonicity were severely impaired after the same treatments. The increase in spontaneous vesicle recycling and the decrease in evoked neurotransmission were reversible upon cholesterol addition. Cholesterol removal did not impact on the low level of evoked neurotransmission seen in the absence of synaptic vesicle SNARE protein synaptobrevin-2 whereas the increase in spontaneous fusion remained. These results suggest that synaptic cholesterol balances evoked and spontaneous neurotransmission by hindering spontaneous synaptic vesicle turnover and sustaining evoked exo-endocytosis. PMID:17170046

  16. 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

  17. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    PubMed

    Fernández-Suárez, María E; Escolà-Gil, Joan C; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-09-07

    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 [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]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.

  18. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    PubMed

    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 [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]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

  19. Regulation of Adaptive Immunity in Health and Disease by Cholesterol Metabolism

    PubMed Central

    Fessler, Michael B.

    2015-01-01

    Four decades ago, it was observed that stimulation of T cells induces rapid changes in cellular cholesterol that are required before proliferation can commence. Investigators returning to this phenomenon have finally revealed its molecular underpinnings. Cholesterol trafficking and its dysregulation are now also recognized to strongly influence dendritic cell function, T cell polarization, and antibody responses. In this review, the state of the literature is reviewed on how cholesterol and its trafficking regulate the cells of the adaptive immune response and in vivo disease phenotypes of dysregulated adaptive immunity, including allergy, asthma, and autoimmune disease. Emerging evidence supporting a potential role for statins and other lipid-targeted therapies in the treatment of these diseases is presented. Just as vascular biologists have embraced immunity in the pathogenesis and treatment of atherosclerosis, so should basic and clinical immunologists in allergy, pulmonology, and other disciplines seek to encompass a basic understanding of lipid science. PMID:26149587

  20. Small GTPases in vesicle trafficking.

    PubMed

    Molendijk, Arthur J; Ruperti, Benedetto; Palme, Klaus

    2004-12-01

    Plant small GTPases belonging to the Rop, Arf, and Rab families are regulators of vesicle trafficking. Rop GTPases regulate actin dynamics and modulate H(2)O(2) production in polar cell growth and pathogen defence. A candidate Rop GDP to Rop GTP exchange factor (RopGEF) SPIKE1 is involved in the morphogenesis of leaf epidermal cells. The ArfGEF GNOM regulates the endosomal recycling of the PIN proteins, which are involved in polar auxin transport. Intracellular localisation of small GTPases and functional studies using dominant mutant versions of Arf and Rab GTPases are defining novel plant-specific membrane compartments, especially those that participate in endosomal vesicle trafficking.

  1. MD-2 binds cholesterol.

    PubMed

    Choi, Soo-Ho; Kim, Jungsu; Gonen, Ayelet; Viriyakosol, Suganya; Miller, Yury I

    2016-02-19

    Cholesterol is a structural component of cellular membranes, which is transported from liver to peripheral cells in the form of cholesterol esters (CE), residing in the hydrophobic core of low-density lipoprotein. Oxidized CE (OxCE) is often found in plasma and in atherosclerotic lesions of subjects with cardiovascular disease. Our earlier studies have demonstrated that OxCE activates inflammatory responses in macrophages via toll-like receptor-4 (TLR4). Here we demonstrate that cholesterol binds to myeloid differentiation-2 (MD-2), a TLR4 ancillary molecule, which is a binding receptor for bacterial lipopolysaccharide (LPS) and is indispensable for LPS-induced TLR4 dimerization and signaling. Cholesterol binding to MD-2 was competed by LPS and by OxCE-modified BSA. Furthermore, soluble MD-2 in human plasma and MD-2 in mouse atherosclerotic lesions carried cholesterol, the finding supporting the biological significance of MD-2 cholesterol binding. These results help understand the molecular basis of TLR4 activation by OxCE and mechanisms of chronic inflammation in atherosclerosis.

  2. Sex trafficking and the exploitation of adolescents.

    PubMed

    McClain, Natalie M; Garrity, Stacy E

    2011-01-01

    Human trafficking affects a surprisingly large number of adolescents around the globe. Women and girls make up the majority of sex trafficking victims. Nurses must be aware of sex trafficking as a form of sexual violence in the adolescent population. Nurses can play a role in identifying, intervening, and advocating for victims of human trafficking as they currently do for patients that are the victims of other types of violent crimes. PMID:21284727

  3. 31 CFR 598.310 - Narcotics trafficking.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Narcotics trafficking. 598.310 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.310 Narcotics trafficking. The term narcotics trafficking means any illicit activity...

  4. 31 CFR 598.310 - Narcotics trafficking.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Narcotics trafficking. 598.310 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.310 Narcotics trafficking. The term narcotics trafficking means any illicit activity...

  5. 31 CFR 598.310 - Narcotics trafficking.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Narcotics trafficking. 598.310 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.310 Narcotics trafficking. The term narcotics trafficking means any illicit activity...

  6. 31 CFR 598.310 - Narcotics trafficking.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Narcotics trafficking. 598.310 Section 598.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... General Definitions § 598.310 Narcotics trafficking. The term narcotics trafficking means any...

  7. 31 CFR 598.310 - Narcotics trafficking.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Narcotics trafficking. 598.310 Section 598.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 598.310 Narcotics trafficking. The term narcotics trafficking means any illicit activity...

  8. Cholesterol depletion induces autophagy

    SciTech Connect

    Cheng, Jinglei; Ohsaki, Yuki; Tauchi-Sato, Kumi; Fujita, Akikazu; Fujimoto, Toyoshi . E-mail: tfujimot@med.nagoya-u.ac.jp

    2006-12-08

    Autophagy is a mechanism to digest cells' own components, and its importance in many physiological and pathological processes is being recognized. But the molecular mechanism that regulates autophagy is not understood in detail. In the present study, we found that cholesterol depletion induces macroautophagy. The cellular cholesterol in human fibroblasts was depleted either acutely using 5 mM methyl-{beta}-cyclodextrin or 10-20 {mu}g/ml nystatin for 1 h, or metabolically by 20 {mu}M mevastatin and 200 {mu}M mevalonolactone along with 10% lipoprotein-deficient serum for 2-3 days. By any of these protocols, marked increase of LC3-II was detected by immunoblotting and by immunofluorescence microscopy, and the increase was more extensive than that caused by amino acid starvation, i.e., incubation in Hanks' solution for several hours. The induction of autophagic vacuoles by cholesterol depletion was also observed in other cell types, and the LC3-positive membranes were often seen as long tubules, >50 {mu}m in length. The increase of LC3-II by methyl-{beta}-cyclodextrin was suppressed by phosphatidylinositol 3-kinase inhibitors and was accompanied by dephosphorylation of mammalian target of rapamycin. By electron microscopy, autophagic vacuoles induced by cholesterol depletion were indistinguishable from those seen after amino acid starvation. These results demonstrate that a decrease in cholesterol activates autophagy by a phosphatidylinositol 3-kinase-dependent mechanism.

  9. Cholesterol Absorption and Metabolism.

    PubMed

    Howles, Philip N

    2016-01-01

    Inhibitors of cholesterol absorption have been sought for decades as a means to treat and prevent cardiovascular diseases (CVDs) associated with hypercholesterolemia. Ezetimibe is the one clear success story in this regard, and other compounds with similar efficacy continue to be sought. In the last decade, the laboratory mouse, with all its genetic power, has become the premier experimental model for discovering the mechanisms underlying cholesterol absorption and has become a critical tool for preclinical testing of potential pharmaceutical entities. This chapter briefly reviews the history of cholesterol absorption research and the various gene candidates that have come under consideration as drug targets. The most common and versatile method of measuring cholesterol absorption is described in detail along with important considerations when interpreting results, and an alternative method is also presented. In recent years, reverse cholesterol transport (RCT) has become an area of intense new interest for drug discovery since this process is now considered another key to reducing CVD risk. The ultimate measure of RCT is sterol excretion and a detailed description is given for measuring neutral and acidic fecal sterols and interpreting the results. PMID:27150091

  10. Human trafficking and the healthcare professional.

    PubMed

    Barrows, Jeffrey; Finger, Reginald

    2008-05-01

    Despite the legislation passed in the 19th century outlawing human slavery, it is more widespread today than at the conclusion of the civil war. Modern human slavery, termed human trafficking, comes in several forms. The most common type of human trafficking is sex trafficking, the sale of women and children into prostitution. Labor trafficking is the sale of men, women, and children into hard labor for which they receive little or no compensation. Other forms of trafficking include child soldiering, war brides, and organ removal. Healthcare professionals play a critical role in both finding victims of human trafficking while they are still in captivity, as well as caring for their mental and physical needs upon release. Those working in the healthcare profession need to be educated regarding how a trafficking victim may present, as well as their unique healthcare needs.

  11. Human trafficking and the healthcare professional.

    PubMed

    Barrows, Jeffrey; Finger, Reginald

    2008-05-01

    Despite the legislation passed in the 19th century outlawing human slavery, it is more widespread today than at the conclusion of the civil war. Modern human slavery, termed human trafficking, comes in several forms. The most common type of human trafficking is sex trafficking, the sale of women and children into prostitution. Labor trafficking is the sale of men, women, and children into hard labor for which they receive little or no compensation. Other forms of trafficking include child soldiering, war brides, and organ removal. Healthcare professionals play a critical role in both finding victims of human trafficking while they are still in captivity, as well as caring for their mental and physical needs upon release. Those working in the healthcare profession need to be educated regarding how a trafficking victim may present, as well as their unique healthcare needs. PMID:18414161

  12. Myeloid differentiation primary response protein 88 couples reverse cholesterol transport to inflammation.

    PubMed

    Smoak, Kathleen A; Aloor, Jim J; Madenspacher, Jennifer; Merrick, B Alex; Collins, Jennifer B; Zhu, Xuewei; Cavigiolio, Giorgio; Oda, Michael N; Parks, John S; Fessler, Michael B

    2010-06-01

    Crosstalk exists in mammalian cells between cholesterol trafficking and innate immune signaling. Apolipoprotein A-I (apoA-I), a serum apolipoprotein that induces antiatherogenic efflux of macrophage cholesterol, is widely described as anti-inflammatory because it neutralizes bacterial lipopolysaccharide. Conversely, lipopolysaccharide-induced inflammation is proatherogenic. However, whether innate immunity plays an endogenous, physiological role in host cholesterol homeostasis in the absence of infection is undetermined. We report that apoA-I signals in the macrophage through Toll-like receptor (TLR)2, TLR4, and CD14, utilizing myeloid differentiation primary response protein 88 (MyD88)-dependent and -independent pathways, to activate nuclear factor-kappaB and induce cytokines. MyD88 plays a critical role in reverse cholesterol transport in vitro and in vivo, in part through promoting ATP-binding cassette A1 transporter upregulation. Taken together, this work identifies apoA-I as an endogenous stimulus of innate immunity that couples cholesterol trafficking to inflammation through MyD88 and identifies innate immunity as a physiologic signal in cholesterol homeostasis.

  13. Parallel computers

    SciTech Connect

    Treveaven, P.

    1989-01-01

    This book presents an introduction to object-oriented, functional, and logic parallel computing on which the fifth generation of computer systems will be based. Coverage includes concepts for parallel computing languages, a parallel object-oriented system (DOOM) and its language (POOL), an object-oriented multilevel VLSI simulator using POOL, and implementation of lazy functional languages on parallel architectures.

  14. CHOLESTEROL AND CHOLESTEROL ESTER CONTENT OF BOVINE COLOSTRUM

    PubMed Central

    Shope, Richard E.; Gowen, John W.

    1928-01-01

    The total amount of cholesterol found in colostrum and milk is comparatively low. The amount of cholesterol found in colostrum declines at an ever decreasing rate as milk secretion develops until at 48 hours the cholesterol is nearly the same as that found in milk 3 months or 7 months after parturition. The morning milk differs from the evening milk in that the cholesterol bound as ester is greater in amount. PMID:19869468

  15. Cholesterol: Up in Smoke.

    ERIC Educational Resources Information Center

    Raloff, Janet

    1991-01-01

    Discussed is the contribution cooked meat makes to air pollution. The dozens of compounds, including cholesterol, that are released when a hamburger is grilled are described. The potential effects of these emissions on humans and the urban environment are discussed. (KR)

  16. Cholesterol, inflammasomes, and atherogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasma cholesterol levels have been strongly associated with atherogenesis, underscoring the role of lipid metabolism in defining cardiovascular disease risk. However, atherosclerotic plaque is highly dynamic and contains elements of both the innate and adaptive immune system that respond to the abe...

  17. Niacin for cholesterol

    MedlinePlus

    ... this page, please enable JavaScript. Niacin is a B-vitamin. When taken as a prescription in larger doses, ... A.M. Editorial team. Related MedlinePlus Health Topics B Vitamins Cholesterol Browse the Encyclopedia A.D.A.M., ...

  18. Trafficking of Vesicular Neurotransmitter Transporters

    PubMed Central

    Fei, Hao; Grygoruk, Anna; Brooks, Elizabeth S.; Chen, Audrey; Krantz, David E.

    2010-01-01

    Vesicular neurotransmitter transporters are required for the storage of all classical and amino acid neurotransmitters in secretory vesicles. Transporter expression can influence neurotransmitter storage and release, and trafficking targets the transporters to different types of secretory vesicles. Vesicular transporters traffic to synaptic vesicles as well as large dense core vesicles, and are recycled to synaptic vesicles at the nerve terminal. Some of the intrinsic signals for these trafficking events have been defined and include a dileucine motif present in multiple transporter subtypes, an acidic cluster in the neural isoform of the vesicular monoamine transporter (VMAT2) and a polyproline motif in the vesicular glutamate transporter VGLUT1. The sorting of VMAT2 and the vesicular acetylcholine transporter (VAChT) to secretory vesicles is regulated by phosphorylation. In addition, VGLUT1 uses alternative endocytic pathways for recycling back to synaptic vesicles following exocytosis. Regulation of these sorting events has the potential to influence synaptic transmission and behavior. PMID:18507811

  19. Perfringolysin O Theta Toxin as a Tool to Monitor the Distribution and Inhomogeneity of Cholesterol in Cellular Membranes

    PubMed Central

    Maekawa, Masashi; Yang, Yanbo; Fairn, Gregory D.

    2016-01-01

    Cholesterol is an essential structural component of cellular membranes in eukaryotes. Cholesterol in the exofacial leaflet of the plasma membrane is thought to form membrane nanodomains with sphingolipids and specific proteins. Additionally, cholesterol is found in the intracellular membranes of endosomes and has crucial functions in membrane trafficking. Furthermore, cellular cholesterol homeostasis and regulation of de novo synthesis rely on transport via both vesicular and non-vesicular pathways. Thus, the ability to visualize and detect intracellular cholesterol, especially in the plasma membrane, is critical to understanding the complex biology associated with cholesterol and the nanodomains. Perfringolysin O (PFO) theta toxin is one of the toxins secreted by the anaerobic bacteria Clostridium perfringens and this toxin forms pores in the plasma membrane that causes cell lysis. It is well understood that PFO recognizes and binds to cholesterol in the exofacial leaflets of the plasma membrane, and domain 4 of PFO (D4) is sufficient for the binding of cholesterol. Recent studies have taken advantage of this high-affinity cholesterol-binding domain to create a variety of cholesterol biosensors by using a non-toxic PFO or the D4 in isolation. This review highlights the characteristics and usefulness of, and the principal findings related to, these PFO-derived cholesterol biosensors. PMID:27005662

  20. Viral subversion of nucleocytoplasmic trafficking.

    PubMed

    Yarbrough, Melanie L; Mata, Miguel A; Sakthivel, Ramanavelan; Fontoura, Beatriz M A

    2014-02-01

    Trafficking of proteins and RNA into and out of the nucleus occurs through the nuclear pore complex (NPC). Because of its critical function in many cellular processes, the NPC and transport factors are common targets of several viruses that disrupt key constituents of the machinery to facilitate viral replication. Many viruses such as poliovirus and severe acute respiratory syndrome (SARS) virus inhibit protein import into the nucleus, whereas viruses such as influenza A virus target and disrupt host mRNA nuclear export. Current evidence indicates that these viruses may employ such strategies to avert the host immune response. Conversely, many viruses co-opt nucleocytoplasmic trafficking to facilitate transport of viral RNAs. As viral proteins interact with key regulators of the host nuclear transport machinery, viruses have served as invaluable tools of discovery that led to the identification of novel constituents of nuclear transport pathways. This review explores the importance of nucleocytoplasmic trafficking to viral pathogenesis as these studies revealed new antiviral therapeutic strategies and exposed previously unknown cellular mechanisms. Further understanding of nuclear transport pathways will determine whether such therapeutics will be useful treatments for important human pathogens.

  1. Protein trafficking in kinetoplastid protozoa.

    PubMed Central

    Clayton, C; Häusler, T; Blattner, J

    1995-01-01

    The kinetoplastid protozoa infect hosts ranging from invertebrates to plants and mammals, causing diseases of medical and economic importance. They are the earliest-branching organisms in eucaryotic evolution to have either mitochondria or peroxisome-like microbodies. Investigation of their protein trafficking enables us to identify characteristics that have been conserved throughout eucaryotic evolution and also reveals how far variations, or alternative mechanisms, are possible. Protein trafficking in kinetoplastids is in many respects similar to that in higher eucaryotes, including mammals and yeasts. Differences in signal sequence specificities exist, however, for all subcellular locations so far examined in detail--microbodies, mitochondria, and endoplasmic reticulum--with signals being more degenerate, or shorter, than those of their higher eucaryotic counterparts. Some components of the normal array of trafficking mechanisms may be missing in most (if not all) kinetoplastids: examples are clathrin-coated vesicles, recycling receptors, and mannose 6-phosphate-mediated lysosomal targeting. Other aspects and structures are unique to the kinetoplastids or are as yet unexplained. Some of these peculiarities may eventually prove to be weak points that can be used as targets for chemotherapy; others may turn out to be much more widespread than currently suspected. PMID:7565409

  2. Viral Subversion of Nucleocytoplasmic Trafficking

    PubMed Central

    Yarbrough, Melanie L.; Mata, Miguel A.; Sakthivel, Ramanavelan; Fontoura, Beatriz M. A.

    2014-01-01

    Trafficking of proteins and RNA into and out of the nucleus occurs through the nuclear pore complex (NPC). Due to its critical function in many cellular processes, the NPC and transport factors are common targets of several viruses that disrupt key constituents of the machinery to facilitate viral replication. Many viruses such as poliovirus and severe acute respiratory syndrome (SARS) virus inhibit protein import into the nucleus, while viruses such as influenza A virus target and disrupt host mRNA nuclear export. Current evidence indicates that these viruses may employ such strategies to avert the host immune response. Conversely, many viruses co-opt nucleocytoplasmic trafficking to facilitate transport of viral RNAs. Since viral proteins interact with key regulators of the host nuclear transport machinery, viruses have served as invaluable tools of discovery that led to the identification of novel constituents of nuclear transport pathways. In addition, this review explores the importance of nucleocytoplasmic trafficking to viral pathogenesis as these studies revealed new antiviral therapeutic strategies and exposed previously unknown cellular mechanisms. Further understanding of nuclear transport pathways will determine whether such therapeutics will be useful treatments for important human pathogens. PMID:24289861

  3. Agonist-trafficking and hallucinogens.

    PubMed

    González-Maeso, Javier; Sealfon, Stuart C

    2009-01-01

    Seven transmembrane domain receptors, also termed G protein-coupled receptors (GPCRs), represent the most common molecular target for therapeutic drugs. The generally accepted pharmacological model for GPCR activation is the ternary complex model, in which GPCRs exist in a dynamic equilibrium between the active and inactive conformational states. However, the demonstration that different agonists sometimes elicit a different relative activation of two signaling pathways downstream of the same receptor has led to a revision of the ternary complex model. According to this agonist- trafficking model, agonists stabilize distinct activated receptor conformations that preferentially activate specific signaling pathways. Hallucinogenic drugs and non-hallucinogenic drugs represent an attractive experimental system with which to study agonist-trafficking of receptor signaling. Thus many of the behavioral responses induced by hallucinogenic drugs, such as lysergic acid diethylamide (LSD), psilocybin or mescaline, depend on activation of serotonin 5-HT(2A) receptors (5-HT2ARs). In contrast, this neuropsychological state in humans is not induced by closely related chemicals, such as lisuride or ergotamine, despite their similar in vitro activity at the 5-HT2AR. In this review, we summarize the current knowledge, as well as unresolved questions, regarding agonist-trafficking and the mechanism of action of hallucinogenic drugs.

  4. Cholesterol transport in model membranes

    NASA Astrophysics Data System (ADS)

    Garg, Sumit; Porcar, Lionel; Butler, Paul; Perez-Salas, Ursula

    2010-03-01

    Physiological processes distribute cholesterol unevenly within the cell. The levels of cholesterol are maintained by intracellular transport and a disruption in the cell's ability to keep these normal levels will lead to disease. Exchange rates of cholesterol are generally studied in model systems using labeled lipid vesicles. Initially donor vesicles have all the cholesterol and acceptor vesicles are devoid of it. They are mixed and after some time the vesicles are separated and cholesterol is traced in each vesicle. The studies performed up to date have significant scatter indicating that the methodologies are not consistent. The present work shows in-situ Time-Resolved SANS studies of cholesterol exchange rates in unsaturated PC lipid vesicles. Molecular dynamics simulations were done to investigate the energetic and kinetic behavior of cholesterol in this system. This synergistic approach will provide insight into our efforts to understand cholesterol traffic.

  5. Cholesterol-Dependent Anaplasma phagocytophilum Exploits the Low-Density Lipoprotein Uptake Pathway

    PubMed Central

    Xiong, Qingming; Lin, Mingqun; Rikihisa, Yasuko

    2009-01-01

    In eukaryotes, intracellular cholesterol homeostasis and trafficking are tightly regulated. Certain bacteria, such as Anaplasma phagocytophilum, also require cholesterol; it is unknown, however, how this cholesterol-dependent obligatory intracellular bacterium of granulocytes interacts with the host cell cholesterol regulatory pathway to acquire cholesterol. Here, we report that total host cell cholesterol increased >2-fold during A. phagocytophilum infection in a human promyelocytic leukemia cell line. Cellular free cholesterol was enriched in A. phagocytophilum inclusions as detected by filipin staining. We determined that A. phagocytophilum requires cholesterol derived from low-density lipoprotein (LDL), because its replication was significantly inhibited by depleting the growth medium of cholesterol-containing lipoproteins, by blocking LDL uptake with a monoclonal antibody against LDL receptor (LDLR), or by treating the host cells with inhibitors that block LDL-derived cholesterol egress from late endosomes or lysosomes. However, de novo cholesterol biosynthesis is not required, since inhibition of the biosynthesis pathway did not inhibit A. phagocytophilum infection. The uptake of fluorescence-labeled LDL was enhanced in infected cells, and LDLR expression was up-regulated at both the mRNA and protein levels. A. phagocytophilum infection stabilized LDLR mRNA through the 3′ UTR region, but not through activation of the sterol regulatory element binding proteins. Extracellular signal–regulated kinase (ERK) was up-regulated by A. phagocytophilum infection, and inhibition of its upstream kinase, MEK, by a specific inhibitor or siRNA knockdown, reduced A. phagocytophilum infection. Up-regulation of LDLR mRNA by A. phagocytophilum was also inhibited by the MEK inhibitor; however, it was unclear whether ERK activation is required for LDLR mRNA up-regulation by A. phagocytophilum. These data reveal that A. phagocytophilum exploits the host LDL uptake pathway and

  6. Regulation of aquaporin-2 trafficking.

    PubMed

    Nedvetsky, Pavel I; Tamma, Grazia; Beulshausen, Sven; Valenti, Giovanna; Rosenthal, Walter; Klussmann, Enno

    2009-01-01

    Principal cells lining renal collecting ducts control the fine-tuning of body water homeostasis by regulating water reabsorption through the water channels aquaporin-2 (AQP2), aquaporin-3 (AQP3), and aquaporin-4 (AQP4). While the localization of AQP2 is subject to regulation by arginine-vasopressin (AVP), AQP3 and AQP4 are constitutively expressed in the basolateral plasma membrane. AVP adjusts the amount of AQP2 in the plasma membrane by triggering its redistribution from intracellular vesicles into the plasma membrane. This permits water entry into the cells and water exit through AQP3 and AQP4. The translocation of AQP2 is initiated by an increase in cAMP following V2R activation through AVP. The AVP-induced rise in cAMP activates protein kinase A (PKA), which in turn phosphorylates AQP2, and thereby triggers the redistribution of AQP2. Several proteins participating in the control of cAMP-dependent AQP2 trafficking have been identified; for example, A kinase anchoring proteins (AKAPs) tethering PKA to cellular compartments; phosphodiesterases (PDEs) regulating the local cAMP level; cytoskeletal components such as F-actin and microtubules; small GTPases of the Rho family controlling cytoskeletal dynamics; motor proteins transporting AQP2-bearing vesicles to and from the plasma membrane for exocytic insertion and endocytic retrieval; SNAREs inducing membrane fusions, hsc70, a chaperone, important for endocytic retrieval. In addition, cAMP-independent mechanisms of translocation mainly involving the F-actin cytoskeleton have been uncovered. Defects of AQP2 trafficking cause diseases such as nephrogenic diabetes insipidus (NDI), a disorder characterized by a massive loss of hypoosmotic urine.This review summarizes recent data elucidating molecular mechanisms underlying the trafficking of AQP2. In particular, we focus on proteins involved in the regulation of trafficking, and physiological and pathophysiological stimuli determining the cellular localization of AQP2

  7. Human Trafficking in the Emergency Department

    PubMed Central

    Patel, Ronak B.; Ahn, Roy; Burke, Thomas F.

    2010-01-01

    Human trafficking continues to persist, affecting up to 200 million people worldwide. As clinicians in emergency departments commonly encounter victims of intimate partner violence, some of these encounters will be with trafficking victims. These encounters provide a rare opportunity for healthcare providers to intervene and help. This case report of a human trafficking patient from a teaching hospital illustrates the complexity in identifying these victims. Clinicians can better identify potential trafficking cases by increasing their awareness of this phenomenon, using qualified interpreters, isolating potential victims by providing privacy and using simple clear reassuring statements ensuring security. A multidisciplinary approach can then be mobilized to help these patients. PMID:21293753

  8. Understand Your Risk for High Cholesterol

    MedlinePlus

    ... or trans fats also increases the amount of LDL cholesterol in your blood. If high blood cholesterol runs ... may not be enough to help lower your LDL blood cholesterol. View an animation of cholesterol . More information: Women ...

  9. Overview of Cholesterol and Lipid Disorders

    MedlinePlus

    ... Cholesterol and Lipid Disorders Dyslipidemia Hypolipidemia Cholesterol and triglycerides are important fats (lipids) in the blood. Cholesterol ... needs, but it also obtains cholesterol from food. Triglycerides, which are contained in fat cells, can be ...

  10. Modulation of PICALM Levels Perturbs Cellular Cholesterol Homeostasis.

    PubMed

    Mercer, Jacob L; Argus, Joseph P; Crabtree, Donna M; Keenan, Melissa M; Wilks, Moses Q; Chi, Jen-Tsan Ashley; Bensinger, Steven J; Lavau, Catherine P; Wechsler, Daniel S

    2015-01-01

    PICALM (Phosphatidyl Inositol Clathrin Assembly Lymphoid Myeloid protein) is a ubiquitously expressed protein that plays a role in clathrin-mediated endocytosis. PICALM also affects the internalization and trafficking of SNAREs and modulates macroautophagy. Chromosomal translocations that result in the fusion of PICALM to heterologous proteins cause leukemias, and genome-wide association studies have linked PICALM Single Nucleotide Polymorphisms (SNPs) to Alzheimer's disease. To obtain insight into the biological role of PICALM, we performed gene expression studies of PICALM-deficient and PICALM-expressing cells. Pathway analysis demonstrated that PICALM expression influences the expression of genes that encode proteins involved in cholesterol biosynthesis and lipoprotein uptake. Gas Chromatography-Mass Spectrometry (GC-MS) studies indicated that loss of PICALM increases cellular cholesterol pool size. Isotopic labeling studies revealed that loss of PICALM alters increased net scavenging of cholesterol. Flow cytometry analyses confirmed that internalization of the LDL receptor is enhanced in PICALM-deficient cells as a result of higher levels of LDLR expression. These findings suggest that PICALM is required for cellular cholesterol homeostasis and point to a novel mechanism by which PICALM alterations may contribute to disease. PMID:26075887

  11. Cholesterol Metabolism in CKD.

    PubMed

    Reiss, Allison B; Voloshyna, Iryna; De Leon, Joshua; Miyawaki, Nobuyuki; Mattana, Joseph

    2015-12-01

    Patients with chronic kidney disease (CKD) have a substantial risk of developing coronary artery disease. Traditional cardiovascular disease (CVD) risk factors such as hypertension and hyperlipidemia do not adequately explain the high prevalence of CVD in CKD. Both CVD and CKD are inflammatory states and inflammation adversely affects lipid balance. Dyslipidemia in CKD is characterized by elevated triglyceride levels and high-density lipoprotein levels that are both decreased and dysfunctional. This dysfunctional high-density lipoprotein becomes proinflammatory and loses its atheroprotective ability to promote cholesterol efflux from cells, including lipid-overloaded macrophages in the arterial wall. Elevated triglyceride levels result primarily from defective clearance. The weak association between low-density lipoprotein cholesterol level and coronary risk in CKD has led to controversy over the usefulness of statin therapy. This review examines disrupted cholesterol transport in CKD, presenting both clinical and preclinical evidence of the effect of the uremic environment on vascular lipid accumulation. Preventative and treatment strategies are explored. PMID:26337134

  12. Cholesterol binding to ion channels

    PubMed Central

    Levitan, Irena; Singh, Dev K.; Rosenhouse-Dantsker, Avia

    2014-01-01

    Numerous studies demonstrated that membrane cholesterol is a major regulator of ion channel function. The goal of this review is to discuss significant advances that have been recently achieved in elucidating the mechanisms responsible for cholesterol regulation of ion channels. The first major insight that comes from growing number of studies that based on the sterol specificity of cholesterol effects, show that several types of ion channels (nAChR, Kir, BK, TRPV) are regulated by specific sterol-protein interactions. This conclusion is supported by demonstrating direct saturable binding of cholesterol to a bacterial Kir channel. The second major advance in the field is the identification of putative cholesterol binding sites in several types of ion channels. These include sites at locations associated with the well-known cholesterol binding motif CRAC and its reversed form CARC in nAChR, BK, and TRPV, as well as novel cholesterol binding regions in Kir channels. Notably, in the majority of these channels, cholesterol is suggested to interact mainly with hydrophobic residues in non-annular regions of the channels being embedded in between transmembrane protein helices. We also discuss how identification of putative cholesterol binding sites is an essential step to understand the mechanistic basis of cholesterol-induced channel regulation. Clearly, however, these are only the first few steps in obtaining a general understanding of cholesterol-ion channels interactions and their roles in cellular and organ functions. PMID:24616704

  13. The effect of cholesterol domains on PEGylated liposomal gene delivery in vitro

    PubMed Central

    Xu, Long; Wempe, Michael F; Anchordoquy, Thomas J

    2011-01-01

    Aim PEGylated components have been widely used to reduce particle aggregation in serum and extend circulation lifetime for lipid- and polymer-based gene-delivery systems. However, PEGylation is known to interfere with cell interaction and intracellular trafficking, resulting in decreased biological activity. In the present study, the effect of cholesterol domains on PEGylated liposome-mediated gene delivery was evaluated by PEGylating formulations with and without a cholesterol domain, and also by altering the location of PEG on the particle surface (i.e., within or excluded from the domain). Materials and methods Lipoplexes formulated with PEG–cholesterol or PEG–diacyl lipid were used to transfect various cell lines, including human and mouse cancer cells. Cellular uptake of lipoplexes was also quantified and compared with the transfection results. Results Our findings are consistent with previous work demonstrating that PEGylation reduces transfection rates; however, formulations in which PEG was incorporated into the cholesterol domain did not exhibit this detrimental effect. In some cell lines, the incorporation of PEG into the domain actually increased transfection rates, despite no enhancement of cellular uptake. Discussion These results suggest that the adverse alterations in intracellular trafficking that are a consequence of PEGylation may be avoided by utilizing delivery vehicles that allow PEG to partition into a cholesterol domain. PMID:22428082

  14. Sterol carrier protein 2 participates in hypersecretion of biliary cholesterol during gallstone formation in genetically gallstone-susceptible mice.

    PubMed Central

    Fuchs, M; Lammert, F; Wang, D Q; Paigen, B; Carey, M C; Cohen, D E

    1998-01-01

    In inbred mice, susceptibility to cholesterol gallstone disease is conferred by Lith genes, which in part promote hypersecretion of cholesterol into bile in response to a high-fat/cholesterol/cholic acid (lithogenic) diet. Because cytosolic sterol carrier protein 2 (SCP2) is believed to participate in cellular cholesterol trafficking and is elevated in the liver cytosol of cholesterol gallstone patients, we defined the hepatic expression of SCP2 during cholesterol gallstone formation in gallstone-susceptible C57L and gallstone-resistant AKR mice fed the lithogenic diet. Steady-state cytosolic SCP2 levels in C57L, but not AKR mice increased as a function of time and were correlated positively with biliary cholesterol hypersecretion, cholesterol saturation indices of gall-bladder biles and the appearance of liquid and solid cholesterol crystals leading to gallstone formation. Steady-state mRNA levels increased co-ordinately, consistent with regulation of SCP2 expression at the transcriptional level. Our results suggest that overexpression of SCP2 contributes to biliary cholesterol hypersecretion and the pathogenesis of gallstones in genetically susceptible mice. Because of the different chromosomal localizations of the Lith and Scp2 genes, we postulate that Lith genes control SCP2 expression indirectly. PMID:9806881

  15. Molybdenum Trafficking for Nitrogen Fixation†

    PubMed Central

    Hernandez, Jose A.; George, Simon J.; Rubio, Luis M.

    2009-01-01

    The molybdenum nitrogenase is responsible for most biological nitrogen fixation, a prokaryotic metabolic process that determines the global biogeochemical cycles of nitrogen and carbon. Here we describe the trafficking of molybdenum for nitrogen fixation in the model diazotrophic bacterium Azotobacter vinelandii. The genes and proteins involved in molybdenum uptake, homeostasis, storage, regulation, and nitrogenase cofactor biosynthesis are reviewed. Molybdenum biochemistry in A. vinelandii reveals unexpected mechanisms and a new role for iron-sulfur clusters in the sequestration and delivery of molybdenum. PMID:19772354

  16. Optical Control of Peroxisomal Trafficking.

    PubMed

    Spiltoir, Jessica I; Strickland, Devin; Glotzer, Michael; Tucker, Chandra L

    2016-07-15

    The blue-light-responsive LOV2 domain of Avena sativa phototropin1 (AsLOV2) has been used to regulate activity and binding of diverse protein targets with light. Here, we used AsLOV2 to photocage a peroxisomal targeting sequence, allowing light regulation of peroxisomal protein import. We generated a protein tag, LOV-PTS1, that can be appended to proteins of interest to direct their import to the peroxisome with light. This method provides a means to inducibly trigger peroxisomal protein trafficking in specific cells at user-defined times. PMID:26513473

  17. Preliminary Validation of the Sex Trafficking Attitudes Scale.

    PubMed

    Houston-Kolnik, Jaclyn D; Todd, Nathan R; Wilson, Midge

    2016-09-01

    This study presents the Sex Trafficking Attitudes Scale (STAS), assessing cognitive, behavioral, and affective attitudes toward the sex trafficking of women and girls. Across two studies, exploratory and confirmatory factor analyses revealed and confirmed six subscales: (a) Knowledge About Sex Trafficking, (b) Awareness of Sex Trafficking, (c) Attitudes Toward Ability to Leave Sex Trafficking, (d) Attitudes Toward Helping Survivors, (e) Empathic Reactions Toward Sex Trafficking, and (f) Efficacy to Reduce Sex Trafficking. Results showed support for convergent validity as the subscales were associated with related measures. The STAS holds promise to expand research and inform efforts to support trafficking survivors.

  18. Intracellular trafficking of nucleic acids.

    PubMed

    Zhou, Rui; Geiger, R Christopher; Dean, David A

    2004-11-01

    Until recently, the attention of most researchers has focused on the first and last steps of gene transfer, namely delivery to the cell and transcription, in order to optimise transfection and gene therapy. However, over the past few years, researchers have realised that the intracellular trafficking of plasmids is more than just a "black box" and is actually one of the major barriers to effective gene delivery. After entering the cytoplasm, following direct delivery or endocytosis, plasmids or other vectors must travel relatively long distances through the mesh of cytoskeletal networks before reaching the nuclear envelope. Once at the nuclear envelope, the DNA must either wait until cell division, or be specifically transported through the nuclear pore complex, in order to reach the nucleoplasm where it can be transcribed. This review focuses on recent developments in the understanding of these intracellular trafficking events as they relate to gene delivery. Hopefully, by continuing to unravel the mechanisms by which plasmids and other gene delivery vectors move throughout the cell, and by understanding the cell biology of gene transfer, superior methods of transfection and gene therapy can be developed.

  19. The ABCA1 transporter modulates late endocytic trafficking: insights from the correction of the genetic defect in Tangier disease.

    PubMed

    Neufeld, Edward B; Stonik, John A; Demosky, Stephen J; Knapper, Catherine L; Combs, Christian A; Cooney, Adele; Comly, Marcella; Dwyer, Nancy; Blanchette-Mackie, Joan; Remaley, Alan T; Santamarina-Fojo, Silvia; Brewer, H Bryan

    2004-04-01

    We have previously established that the ABCA1 transporter, which plays a critical role in the lipidation of extracellular apolipoprotein acceptors, traffics between late endocytic vesicles and the cell surface (Neufeld, E. B., Remaley, A. T., Demosky, S. J., Jr., Stonik, J. A., Cooney, A. M., Comly, M., Dwyer, N. K., Zhang, M., Blanchette-Mackie, J., Santamarina-Fojo, S., and Brewer, H. B., Jr. (2001) J. Biol. Chem. 276, 27584-27590). The present study provides evidence that ABCA1 in late endocytic vesicles plays a role in cellular lipid efflux. Late endocytic trafficking was defective in Tangier disease fibroblasts that lack functional ABCA1. Consistent with a late endocytic protein trafficking defect, the hydrophobic amine U18666A retained NPC1 in abnormally tubulated, cholesterol-poor, Tangier disease late endosomes, rather than cholesterol-laden lysosomes, as in wild type fibroblasts. Consistent with a lipid trafficking defect, Tangier disease late endocytic vesicles accumulated both cholesterol and sphingomyelin and were immobilized in a perinuclear localization. The excess cholesterol in Tangier disease late endocytic vesicles retained massive amounts of NPC1, which traffics lysosomal cholesterol to other cellular sites. Exogenous apoA-I abrogated the cholesterol-induced retention of NPC1 in wild type but not in Tangier disease late endosomes. Adenovirally mediated ABCA1-GFP expression in Tangier disease fibroblasts corrected the late endocytic trafficking defects and restored apoA-I-mediated cholesterol efflux. ABCA1-GFP expression in wild type fibroblasts also reduced late endosome-associated NPC1, induced a marked uptake of fluorescent apoA-I into ABCA1-GFP-containing endosomes (that shuttled between late endosomes and the cell surface), and enhanced apoA-I-mediated cholesterol efflux. The combined results of this study suggest that ABCA1 converts pools of late endocytic lipids that retain NPC1 to pools that can associate with endocytosed apoA-I, and be

  20. Examining the Risk of Nuclear Trafficking

    SciTech Connect

    Balatsky, Galya; Severe, William R; Schoeneck, Jeffery

    2009-01-01

    The need to stop illicit trafficking of nuclear and radioactive materials around the world is undeniable and urgent. This issue is particularly evident due to the highly dangerous consequences of the risks involved, the known interest of terrorist groups in acquiring such materials and the vulnerability of theft and diversion of such materials. Yet the phenomenon of nuclear trafficking remains a subject where the unknown dominates what is known on the subject. The trafficking panel at the Institute for Nuclear Materials Management (INMM) Workshop on Reducing the Risk of Radioactive and Nuclear Materials that took place in Albuquerque, New Mexico, March 10-11, 2009, dealt with some of the issues associated with nuclear trafficking. Different points of view on how to better address trafficking and thwart perpetrator efforts were discussed. This paper presents some of these views and addresses practical measures that should be considered to improve the situation.

  1. Improved Coarse-Grained Modeling of Cholesterol-Containing Lipid Bilayers

    SciTech Connect

    Daily, Michael D.; Olsen, Brett N.; Schlesinger, Paul H.; Ory, Daniel S.; Baker, Nathan A.

    2014-03-24

    In mammalian cells cholesterol is essential for membrane function, but in excess can be cytototoxic. The cellular response to acute cholesterol loading involves biophysical-based mechanisms that regulate cholesterol levels, through modulation of the “activity” or accessibility of cholesterol to extra-membrane acceptors. Experiments and united atom (UA) simulations show that at high concentrations of cholesterol, lipid bilayers thin significantly and cholesterol availability to external acceptors increases substantially. Such cholesterol activation is critical to its trafficking within cells. Here we aim to reduce the computational cost to enable simulation of large and complex systems involved in cholesterol regulation, such as those including oxysterols and cholesterol-sensing proteins. To accomplish this, we have modified the published MARTINI coarse-grained force field to improve its predictions of cholesterol-induced changes in both macroscopic and microscopic properties of membranes. Most notably, MARTINI fails to capture both the (macroscopic) area condensation and membrane thickening seen at less than 30% cholesterol and the thinning seen above 40% cholesterol. The thinning at high concentration is critical to cholesterol activation. Microscopic properties of interest include cholesterol-cholesterol radial distribution functions (RDFs), tilt angle, and accessible surface area. First, we develop an “angle-corrected” model wherein we modify the coarse-grained bond angle potentials based on atomistic simulations. This modification significantly improves prediction of macroscopic properties, most notably the thickening/thinning behavior, and also slightly improves microscopic property prediction relative to MARTINI. Second, we add to the angle correction a “volume correction” by also adjusting phospholipid bond lengths to achieve a more accurate volume per molecule. The angle + volume correction substantially further improves the quantitative

  2. Following intracellular cholesterol transport by linear and non-linear optical microscopy of intrinsically fluorescent sterols.

    PubMed

    Wüstner, Daniel

    2012-02-01

    Elucidation of intracellular cholesterol transport is important for understanding the molecular basis of several metabolic and neuronal diseases, like atheroclerosis or lysosomal storage disorders. Progress in this field depends crucially on the development of new technical approaches to follow the cellular movement of this essential lipid molecule. In this article, a survey of the various methods being used for analysis of sterol trafficking is given. Various classical biochemical methods are presented and their suitability for analysis of sterol trafficking is assessed. Special emphasis is on recent developments in imaging technology to follow the intracellular fate of intrinsically fluorescent sterols as faithful cholesterol markers. In particular, UV-sensitive wide field and multiphoton microscopy of the sterol dehydroergosterol, DHE, is explained and new methods of quantitative image analysis like pixel-wise bleach rate fitting and multiphoton image correlation spectroscopy are introduced. Several applications of the new technology including observation of vectorial sterol trafficking in polarized human hepatoma cells for investigation of reverse cholesterol transport are presented. PMID:21470123

  3. Endocytic Trafficking of Membrane-Bound Cargo: A Flotillin Point of View

    PubMed Central

    Meister, Melanie; Tikkanen, Ritva

    2014-01-01

    The ubiquitous and highly conserved flotillin proteins, flotillin-1 and flotillin-2, have been shown to be involved in various cellular processes such as cell adhesion, signal transduction through receptor tyrosine kinases as well as in cellular trafficking pathways. Due to the fact that flotillins are acylated and form hetero-oligomers, they constitutively associate with cholesterol-enriched lipid microdomains. In recent years, such microdomains have been appreciated as platforms that participate in endocytosis and other cellular trafficking steps. This review summarizes the current findings on the role of flotillins in membrane-bound cargo endocytosis and endosomal trafficking events. We will discuss the proposed function of flotillins in endocytosis in the light of recent findings that point towards a role for flotillins in a step that precedes the actual endocytic uptake of cargo molecules. Recent findings have also revealed that flotillins may be important for endosomal sorting and recycling of specific cargo molecules. In addition to these aspects, the cellular trafficking pathway of flotillins themselves as potential cargo in the context of growth factor signaling will be discussed. PMID:25019426

  4. Parallel rendering

    NASA Technical Reports Server (NTRS)

    Crockett, Thomas W.

    1995-01-01

    This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

  5. 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

  6. Cholesterol Is Required for Endocytosis and Endosomal Escape of Adenovirus Type 2

    PubMed Central

    Imelli, Nicola; Meier, Oliver; Boucke, Karin; Hemmi, Silvio; Greber, Urs F.

    2004-01-01

    The species C adenovirus type 2 (Ad2) and Ad5 bind the coxsackievirus B Ad receptor and αv integrin coreceptors and enter epithelial cells by clathrin-mediated endocytosis. This pathway is rapid and efficient. It leads to cell activation and the cholesterol-dependent formation of macropinosomes. Macropinosomes are triggered to release their contents when incoming Ad2 escapes from endosomes. Here, we show that cholesterol extraction of epithelial cells by methyl-β-cyclodextrin (mβCD) treatment reduced Ad5-mediated luciferase expression ∼4-fold. The addition of cholesterol to normal cells increased gene expression in a dose-dependent manner up to threefold, but it did not restore gene expression in mβCD-treated cells. mβCD had no effect in the presence of excess cholesterol, indicating that the inhibition of gene expression was due specifically to cholesterol depletion. Cholesterol depletion inhibited rapid Ad2 endocytosis, endosomal escape, and nuclear targeting, consistent with the notion that clathrin-dependent endocytosis of Ad2 is cholesterol dependent. In cholesterol-reduced cells, Ad2 internalized at a low rate, suggestive of an alternative, clathrin-independent, low-capacity entry pathway. While exogenous cholesterol completely restored rapid Ad2 endocytosis, macropinocytosis, and macropinosome disruption, it did not, surprisingly, restore viral escape from endosomes. Our results indicate that macropinosome disruption and endosomal escape of Ad2 are independent events in cells depleted of and then refilled with cholesterol, suggesting that viral escape from endosomes requires lipid-controlled membrane homeostasis, trafficking, or signaling. PMID:14990728

  7. Trafficking to the Ciliary Membrane

    PubMed Central

    Nachury, Maxence V.; Seeley, E. Scott; Jin, Hua

    2010-01-01

    The primary cilium organizes numerous signal transduction cascades and an understanding of signaling receptors trafficking to cilia is now emerging. A defining feature of cilia is the periciliary diffusion barrier that separates the ciliary and plasma membranes despite the topological continuity between these two membranes. Although lateral transport through this barrier may take place, polarized exocytosis to the base of the cilium has been the prevailing model for delivering membrane proteins to cilia. Key players for this polarized exocytosis model include the GTPases Rab8 and Rab11, the exocyst and possibly the intraflagellar tranport machinery. Sorting membrane proteins to cilia critically relies on the recognition of ciliary targeting signals by sorting machines such as the BBSome coat complex or the GTPase Arf4. Finally, signaling at the cilium entails the bidirectional movement of proteins between cytoplasm and cilia and ubiquitination may promote exit from cilia. PMID:19575670

  8. Specific Cellular Incorporation of a Pyrene-Labelled Cholesterol: Lipoprotein-Mediated Delivery toward Ordered Intracellular Membranes

    PubMed Central

    Gaibelet, Gérald; Azalbert, Vincent; Bertrand-Michel, Justine; Hamdi, Safouane; Collet, Xavier; Orlowski, Stéphane

    2015-01-01

    In the aim of testing tools for tracing cell trafficking of exogenous cholesterol, two fluorescent derivatives of cholesterol, 22-nitrobenzoxadiazole-cholesterol (NBD-Chol) and 21-methylpyrenyl-cholesterol (Pyr-met-Chol), with distinctive chemico-physical characteristics, have been compared for their cell incorporation properties, using two cell models differently handling cholesterol, with two incorporation routes. In the Caco-2 cell model, the cholesterol probes were delivered in bile salt micelles, as a model of intestinal absorption. The two probes displayed contrasting behaviors for cell uptake characteristics, cell staining, and efflux kinetics. In particular, Pyr-met-Chol cell incorporation involved SR-BI, while that of NBD-Chol appeared purely passive. In the PC-3 cell model, which overexpresses lipoprotein receptors, the cholesterol probes were delivered via the serum components, as a model of systemic delivery. We showed that Pyr-met-Chol-labelled purified LDL or HDL were able to specifically deliver Pyr-met-Chol to the PC-3 cells, while NBD-Chol incorporation was independent of lipoproteins. Observations by fluorescence microscopy evidenced that, while NBD-Chol readily stained the cytosolic lipid droplets, Pyr-met-Chol labelling led to the intense staining of intracellular structures of membranous nature, in agreement with the absence of detectable esterification of Pyr-met-Chol. A 48 h incubation of PC-3 cells with either Pyr-met-Chol-labelled LDL or HDL gave same staining patterns, mainly colocalizing with Lamp1, caveolin-1 and CD63. These data indicated convergent trafficking downwards their respective receptors, LDL-R and SR-BI, toward the cholesterol-rich internal membrane compartments, late endosomes and multivesicular bodies. Interestingly, Pyr-met-Chol staining of these structures exhibited a high excimer fluorescence emission, revealing their ordered membrane environment, and indicating that Pyr-met-Chol behaves as a fair cholesterol tracer

  9. Food combinations for cholesterol lowering.

    PubMed

    Harland, Janice I

    2012-12-01

    Reducing elevated LDL-cholesterol is a key public health challenge. There is substantial evidence from randomised controlled trials (RCT) that a number of foods and food components can significantly reduce LDL-cholesterol. Data from RCT have been reviewed to determine whether effects are additive when two or more of these components are consumed together. Typically components, such as plant stanols and sterols, soya protein, β-glucans and tree nuts, when consumed individually at their target rate, reduce LDL-cholesterol by 3-9 %. Improved dietary fat quality, achieved by replacing SFA with unsaturated fat, reduces LDL-cholesterol and can increase HDL-cholesterol, further improving blood lipid profile. It appears that the effect of combining these interventions is largely additive; however, compliance with multiple changes may reduce over time. Food combinations used in ten 'portfolio diet' studies have been reviewed. In clinical efficacy studies of about 1 month where all foods were provided, LDL-cholesterol is reduced by 22-30 %, whereas in community-based studies of >6 months' duration, where dietary advice is the basis of the intervention, reduction in LDL-cholesterol is about 15 %. Inclusion of MUFA into 'portfolio diets' increases HDL-cholesterol, in addition to LDL-cholesterol effects. Compliance with some of these dietary changes can be achieved more easily compared with others. By careful food component selection, appropriate to the individual, the effect of including only two components in the diet with good compliance could be a sustainable 10 % reduction in LDL-cholesterol; this is sufficient to make a substantial impact on cholesterol management and reduce the need for pharmaceutical intervention.

  10. Stimulation of cholesterol excretion by the liver X receptor agonist requires ATP-binding cassette transporters G5 and G8.

    PubMed

    Yu, Liqing; York, Jennifer; von Bergmann, Klaus; Lutjohann, Dieter; Cohen, Jonathan C; Hobbs, Helen H

    2003-05-01

    Liver X receptor (LXR) is a nuclear receptor that plays a crucial role in orchestrating the trafficking of sterols between tissues. Treatment of mice with a potent and specific LXR agonist, T0901317, is associated with increased biliary cholesterol secretion, decreased fractional cholesterol absorption, and increased fecal neutral sterol excretion. Here we show that expression of two target genes of LXRalpha, the ATP-binding cassette (ABC) transporters Abcg5 and Abcg8, is required for both the increase in sterol excretion and the decrease in fractional cholesterol absorption associated with LXR agonist treatment. Mice expressing no ABCG5 and ABCG8 (G5G8(-/-) mice) and their littermate controls were treated for 7 days with T0901317. In wild type animals, treatment with the LXR agonist resulted in a 3-fold increase in biliary cholesterol concentrations, a 25% reduction in fractional cholesterol absorption, and a 4-fold elevation in fecal neutral sterol excretion. In contrast, the LXR agonist did not significantly affect biliary cholesterol levels, fractional cholesterol absorption, or neutral fecal sterol excretion in the G5G8(-/-) mice. Thus Abcg5 and Abcg8 are required for LXR agonist-associated changes in dietary and biliary sterol trafficking. These results establish a central role for ABCG5 and ABCG8 in promoting cholesterol excretion in vivo. PMID:12601003

  11. Female sex trafficking: conceptual issues, current debates, and future directions.

    PubMed

    Meshkovska, Biljana; Siegel, Melissa; Stutterheim, Sarah E; Bos, Arjan E R

    2015-01-01

    Female sex trafficking is a pressing concern. In this article, we provide a comprehensive overview of relevant issues regarding the concept of female sex trafficking and research in the field of human trafficking, drawing on a variety of disciplines, including economics, gender and sexuality studies, psychology, sociology, law, and social work. We discuss the debates surrounding the definition of human trafficking, compare and contrast it with human smuggling, and outline connections between female sex trafficking and the issue of sex work and prostitution. We further discuss the history and current estimations of female sex trafficking. We then outline the main actors in female sex trafficking, including trafficked persons, traffickers, clients, and service providers, and we overview the trafficking process from recruitment to identification, recovery, and (re)integration. Finally, we conclude with recommendations for future research that tie together the concepts of vulnerability, exploitation, and long-term recovery and (re)integration. PMID:25897567

  12. Female sex trafficking: conceptual issues, current debates, and future directions.

    PubMed

    Meshkovska, Biljana; Siegel, Melissa; Stutterheim, Sarah E; Bos, Arjan E R

    2015-01-01

    Female sex trafficking is a pressing concern. In this article, we provide a comprehensive overview of relevant issues regarding the concept of female sex trafficking and research in the field of human trafficking, drawing on a variety of disciplines, including economics, gender and sexuality studies, psychology, sociology, law, and social work. We discuss the debates surrounding the definition of human trafficking, compare and contrast it with human smuggling, and outline connections between female sex trafficking and the issue of sex work and prostitution. We further discuss the history and current estimations of female sex trafficking. We then outline the main actors in female sex trafficking, including trafficked persons, traffickers, clients, and service providers, and we overview the trafficking process from recruitment to identification, recovery, and (re)integration. Finally, we conclude with recommendations for future research that tie together the concepts of vulnerability, exploitation, and long-term recovery and (re)integration.

  13. How cholesterol regulates endothelial biomechanics

    PubMed Central

    Hong, Zhongkui; Staiculescu, Marius C.; Hampel, Paul; Levitan, Irena; Forgacs, Gabor

    2012-01-01

    As endothelial cells form the barrier between blood flow and surrounding tissue, many of their functions depend on mechanical integrity, in particular those of the plasma membrane. As component and organizer of the plasma membrane, cholesterol is a regulator of cellular mechanical properties. Disruption of cholesterol balance leads to impairment of endothelial functions and eventually to disease. The mechanical properties of the membrane are strongly affected by the cytoskeleton. As Phosphatidylinositol-4,5-bisphosphate (PIP2) is a key mediator between the membrane and cytoskeleton, it also affects cellular biomechanical properties. Typically, PIP2 is concentrated in cholesterol-rich microdomains, such as caveolae and lipid rafts, which are particularly abundant in the endothelial plasma membrane. We investigated the connection between cholesterol and PIP2 by extracting membrane tethers from bovine aortic endothelial cells (BAEC) at different cholesterol levels and PIP2 conditions. Our results suggest that in BAEC the role of PIP2, as a mediator of membrane-cytoskeleton adhesion, is regulated by cholesterol. Our findings confirm the specific role of cholesterol in endothelial cells and may have implications for cholesterol-dependent vascular pathologies. PMID:23162471

  14. Massively parallel visualization: Parallel rendering

    SciTech Connect

    Hansen, C.D.; Krogh, M.; White, W.

    1995-12-01

    This paper presents rendering algorithms, developed for massively parallel processors (MPPs), for polygonal, spheres, and volumetric data. The polygon algorithm uses a data parallel approach whereas the sphere and volume renderer use a MIMD approach. Implementations for these algorithms are presented for the Thinking Machines Corporation CM-5 MPP.

  15. Human trafficking law and social structures.

    PubMed

    Wooditch, Alese

    2012-08-01

    Human trafficking has only recently emerged at the forefront of policy reform, even in developed nations. Yet, heightened awareness of the issue has not translated into effective policy as the majority of nations have ineffective antitrafficking practices; many countries have failed to criminalize human trafficking, whereas others do not actively enforce statutes in place. By applying Black's theory of law, this study offers a preliminary understanding into the variation of global prosecutorial efforts in human trafficking and adequacy of antitrafficking law. To isolate this relationship, the effects of trafficking markets are controlled. As with prior research, the study finds limited support for the theory. The article concludes with a discussion on the implications of the quantity of antitrafficking law and morphology association for policy development.

  16. Committee opinion no. 507: human trafficking.

    PubMed

    2011-09-01

    Human trafficking is a widespread problem with estimates ranging from 14,000 to 50,000 individuals trafficked into the United States annually. This hidden population involves the commercial sex industry, agriculture, factories, hotel and restaurant businesses, domestic workers, marriage brokers, and some adoption firms. Because 80% of trafficked individuals are women and girls, women’s health care providers may better serve their diverse patient population by increasing their awareness of this problem. The exploitation of people of any race, gender, sexual orientation, or ethnicity is unacceptable at any time, in any place. The members of the American College of Obstetricians and Gynecologists should be aware of this problem and strive to recognize and assist their patients who are victims or who have been victims of human trafficking. PMID:21860320

  17. Committee opinion no. 507: human trafficking.

    PubMed

    2011-09-01

    Human trafficking is a widespread problem with estimates ranging from 14,000 to 50,000 individuals trafficked into the United States annually. This hidden population involves the commercial sex industry, agriculture, factories, hotel and restaurant businesses, domestic workers, marriage brokers, and some adoption firms. Because 80% of trafficked individuals are women and girls, women’s health care providers may better serve their diverse patient population by increasing their awareness of this problem. The exploitation of people of any race, gender, sexual orientation, or ethnicity is unacceptable at any time, in any place. The members of the American College of Obstetricians and Gynecologists should be aware of this problem and strive to recognize and assist their patients who are victims or who have been victims of human trafficking.

  18. Sex trafficking of women and girls.

    PubMed

    Deshpande, Neha A; Nour, Nawal M

    2013-01-01

    Sex trafficking involves some form of forced or coerced sexual exploitation that is not limited to prostitution, and has become a significant and growing problem in both the United States and the larger global community. The costs to society include the degradation of human and women's rights, poor public health, disrupted communities, and diminished social development. Victims of sex trafficking acquire adverse physical and psychological health conditions and social disadvantages. Thus, sex trafficking is a critical health issue with broader social implications that requires both medical and legal attention. Healthcare professionals can work to improve the screening, identification, and assistance of victims of sex trafficking in a clinical setting and help these women and girls access legal and social services. PMID:23687554

  19. Ovarian Cystadenoma in a Trafficked Patient.

    PubMed

    Titchen, Kanani E; Katz, Douglas; Martinez, Kidian; White, Krishna

    2016-05-01

    The topic of child sex trafficking is receiving increased attention both in the lay press and in research articles. Recently, a number of physician organizations have issued policy statements calling for the education and involvement of physicians in combating this form of "modern-day slavery." Primary care and emergency medicine physicians have led these efforts, but a number of these victims may present to surgeons. Surgeons are in a unique position to identify trafficked patients; during the process of undraping, intubation, and surgical preparation, signs of trafficking such as tattoos, scars, dental injuries, and bruising may be evident. In addition, these patients may have specific needs in terms of anesthesia and postoperative care due to substance abuse. Here, we report the case of an 18-year-old girl with a history of sexual exploitation who presents for cystadenoma excision. To our knowledge, this is the first report of a sex-trafficked pediatric patient presenting for surgery. PMID:27244785

  20. Sex Trafficking of Women and Girls

    PubMed Central

    Deshpande, Neha A; Nour, Nawal M

    2013-01-01

    Sex trafficking involves some form of forced or coerced sexual exploitation that is not limited to prostitution, and has become a significant and growing problem in both the United States and the larger global community. The costs to society include the degradation of human and women’s rights, poor public health, disrupted communities, and diminished social development. Victims of sex trafficking acquire adverse physical and psychological health conditions and social disadvantages. Thus, sex trafficking is a critical health issue with broader social implications that requires both medical and legal attention. Healthcare professionals can work to improve the screening, identification, and assistance of victims of sex trafficking in a clinical setting and help these women and girls access legal and social services. PMID:23687554

  1. Cholesterol - what to ask your doctor

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000211.htm Cholesterol - what to ask your doctor To use the ... this page, please enable JavaScript. Your body needs cholesterol to work properly. When you have extra cholesterol ...

  2. What Do My Cholesterol Levels Mean?

    MedlinePlus

    ... Tools & Resources Stroke More What Do My Cholesterol Levels Mean? Updated:Mar 22,2016 High cholesterol can ... a fasting “lipoprotein profile” to measure your cholesterol levels. It assesses several types of fat in the ...

  3. How to Get Your Cholesterol Tested

    MedlinePlus

    ... HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides. A small sample of blood will be drawn ... the amount of LDL (bad) cholesterol level and triglycerides can be affected by what you've recently ...

  4. A vesicle-trafficking protein commandeers Kv channel voltage sensors for voltage-dependent secretion.

    PubMed

    Grefen, Christopher; Karnik, Rucha; Larson, Emily; Lefoulon, Cécile; Wang, Yizhou; Waghmare, Sakharam; Zhang, Ben; Hills, Adrian; Blatt, Michael R

    2015-01-01

    Growth in plants depends on ion transport for osmotic solute uptake and secretory membrane trafficking to deliver material for wall remodelling and cell expansion. The coordination of these processes lies at the heart of the question, unresolved for more than a century, of how plants regulate cell volume and turgor. Here we report that the SNARE protein SYP121 (SYR1/PEN1), which mediates vesicle fusion at the Arabidopsis plasma membrane, binds the voltage sensor domains (VSDs) of K(+) channels to confer a voltage dependence on secretory traffic in parallel with K(+) uptake. VSD binding enhances secretion in vivo subject to voltage, and mutations affecting VSD conformation alter binding and secretion in parallel with channel gating, net K(+) concentration, osmotic content and growth. These results demonstrate a new and unexpected mechanism for secretory control, in which a subset of plant SNAREs commandeer K(+) channel VSDs to coordinate membrane trafficking with K(+) uptake for growth.

  5. Lateral organization of cholesterol molecules in lipid-cholesterol assemblies.

    SciTech Connect

    Singh, Rajiv R. P.; Slepoy, Alexander; Sengupta, Pinaki; Cox, Daniel L.

    2005-05-01

    We present results of an off-lattice simulation of a two-component planar system, as a model for lateral organization of cholesterol molecules in lipid-cholesterol assemblies. We explore the existence of 'superlattice' structures even in fluid systems, in the absence of an underlying translational long-range order, and study their coupling to hexatic or bond-orientational order. We discuss our results in context of geometric superlattice theories and 'condensation complexes' in understanding a variety of experiments in artificial lipid-cholesterol assemblies.

  6. The transport of low density lipoprotein-derived cholesterol to the plasma membrane is defective in NPC1 cells.

    PubMed

    Wojtanik, Kari M; Liscum, Laura

    2003-04-25

    Niemann-Pick disease type C (NPC) is characterized by lysosomal storage of cholesterol and gangliosides, which results from defects in intracellular lipid trafficking. Most studies of NPC1 have focused on its role in intracellular cholesterol movement. Our hypothesis is that NPC1 facilitates the egress of cholesterol from late endosomes, which are where active NPC1 is located. When NPC1 is defective, cholesterol does not exit late endosomes; instead, it is carried along to lysosomal storage bodies, where it accumulates. In this study, we addressed whether cholesterol is transported from endosomes to the plasma membrane before reaching NPC1-containing late endosomes. Our study was conducted in Chinese hamster ovary cell lines that display the classical NPC biochemical phenotype and belong to the NPC1 complementation group. We used three approaches to test whether low density lipoprotein (LDL)-derived cholesterol en route to NPC1-containing organelles passes through the plasma membrane. First, we used cyclodextrins to measure the arrival of LDL cholesterol at the plasma membrane and found that the arrival of LDL cholesterol in a cyclodextrin-accessible pool was significantly delayed in NPC1 cells. Second, the movement of LDL cholesterol to NPC1-containing late endosomes was assessed and found to be normal in Chinese hamster ovary mutant 3-6, which exhibits defective movement of plasma membrane cholesterol to intracellular membranes. Third, we examined the movement of plasma membrane cholesterol to the endoplasmic reticulum and found that this pathway is intact in NPC1 cells, i.e. it does not pass through NPC1-containing late endosomes. Our data suggest that in NPC1 cells LDL cholesterol traffics directly through endosomes to lysosomes, bypassing the plasma membrane, and is trapped there because of dysfunctional NPC1. PMID:12591922

  7. Targeting mitochondrial 18 kDa translocator protein (TSPO) regulates macrophage cholesterol efflux and lipid phenotype.

    PubMed

    Taylor, Janice M W; Allen, Anne-Marie; Graham, Annette

    2014-11-01

    The aim of the present study was to establish mitochondrial cholesterol trafficking 18 kDa translocator protein (TSPO) as a potential therapeutic target, capable of increasing macrophage cholesterol efflux to (apo)lipoprotein acceptors. Expression and activity of TSPO in human (THP-1) macrophages were manipulated genetically and by the use of selective TSPO ligands. Cellular responses were analysed by quantitative PCR (Q-PCR), immunoblotting and radiolabelling, including [3H]cholesterol efflux to (apo)lipoprotein A-I (apoA-I), high-density lipoprotein (HDL) and human serum. Induction of macrophage cholesterol deposition by acetylated low-density lipoprotein (AcLDL) increased expression of TSPO mRNA and protein, reflecting findings in human carotid atherosclerosis. Transient overexpression of TSPO enhanced efflux (E%) of [3H]cholesterol to apoA-I, HDL and human serum compared with empty vector (EV) controls, whereas gene knockdown of TSPO achieved the converse. Ligation of TSPO (using PK11195, FGIN-1-27 and flunitrazepam) triggered increases in [3H]cholesterol efflux, an effect that was amplified in TSPO-overexpressing macrophages. Overexpression of TSPO induced the expression of genes [PPARA (peroxisome-proliferator-activated receptor α), NR1H3 (nuclear receptor 1H3/liver X receptor α), ABCA1 (ATP-binding cassette A1), ABCG4 (ATP-binding cassette G4) and APOE (apolipoprotein E)] and proteins (ABCA1 and PPARα) involved in cholesterol efflux, reduced macrophage neutral lipid mass and lipogenesis and limited cholesterol esterification following exposure to AcLDL. Thus, targeting TSPO reduces macrophage lipid content and prevents macrophage foam cell formation, via enhanced cholesterol efflux to (apo)lipoprotein acceptors.

  8. Ezetimibe-sensitive cholesterol uptake by NPC1L1 protein does not require endocytosis

    PubMed Central

    Johnson, Tory A.; Pfeffer, Suzanne R.

    2016-01-01

    Human NPC1L1 protein mediates cholesterol absorption in the intestine and liver and is the target of the drug ezetimibe, which is used to treat hypercholesterolemia. Previous studies concluded that NPC1L1-GFP protein trafficking is regulated by cholesterol binding and that ezetimibe blocks NPC1L1-GFP function by inhibiting its endocytosis. We used cell surface biotinylation to monitor NPC1L1-GFP endocytosis and show that ezetimibe does not alter the rate of NPC1L1-GFP endocytosis in cultured rat hepatocytes grown under normal growth conditions. As expected, NPC1L1-GFP endocytosis depends in part on C-terminal, cytoplasmically oriented sequences, but endocytosis does not require cholesterol binding to NPC1L1’s N-terminal domain. In addition, two small- molecule inhibitors of general (and NPC1L1-GFP) endocytosis failed to inhibit the ezetimibe-sensitive uptake of [3H]cholesterol from taurocholate micelles. These experiments demonstrate that cholesterol uptake by NPC1L1 does not require endocytosis; moreover, ezetimibe interferes with NPC1L1’s cholesterol adsorption activity without blocking NPC1L1 internalization in RH7777 cells. PMID:27075173

  9. Think Again About Cholesterol Survey.

    PubMed

    Catapano, Alberico L; Wiklund, Olov

    2015-12-01

    Cardiovascular disease (CVD) is still the main cause of death in Europe. Elevated plasma cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), is the main causative risk factor for CVD, most prominently associated with coronary heart disease. A widespread disinformation about cholesterol and CVD is one factor underlying a poor compliance to lipid-lowering therapy. To investigate how cholesterol, CVD and cholesterol reduction is perceived in the population, a survey was commissioned by the European Atherosclerosis Society (EAS). Nearly half of people above 25 years of age are most worried about cancer (45%), compared to just over one in four who are worried about heart disease (27%). A majority believe being overweight (72%), blood pressure (70%) and smoking (67%) most affect heart health, far more than note cholesterol (59%) and family history (39%). The majority of adults recognize that high LDL (or "bad") cholesterol should be a health priority for everyone, including those younger than 40 and those who are not overweight. However, 1 in 4 (25%) incorrectly believe that it does not need to be a concern until someone shows signs or symptoms. Although 89% of adults surveyed agreed it is important for people to know whether or not they have high LDL-C, an overwhelming 92% did not know their LDL-C levels or had never had their cholesterol levels tested. A high 63% had never heard of familial hypercholesterolemia: France had the lowest level of awareness (41%) to Denmark with a high 80%, and the association of the disease with high levels of LDL-C is quite poor (only 36%), with Sweden only at 22% versus a high in Spain of 54%. A large part of the people participating in the survey were quite uncertain about the modality of transmission for familial hypercholesterolemia in the family. All in all, this survey highlights the need for more information among citizens for the role of cholesterol in determining CVD.

  10. Think Again About Cholesterol Survey.

    PubMed

    Catapano, Alberico L; Wiklund, Olov

    2015-12-01

    Cardiovascular disease (CVD) is still the main cause of death in Europe. Elevated plasma cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), is the main causative risk factor for CVD, most prominently associated with coronary heart disease. A widespread disinformation about cholesterol and CVD is one factor underlying a poor compliance to lipid-lowering therapy. To investigate how cholesterol, CVD and cholesterol reduction is perceived in the population, a survey was commissioned by the European Atherosclerosis Society (EAS). Nearly half of people above 25 years of age are most worried about cancer (45%), compared to just over one in four who are worried about heart disease (27%). A majority believe being overweight (72%), blood pressure (70%) and smoking (67%) most affect heart health, far more than note cholesterol (59%) and family history (39%). The majority of adults recognize that high LDL (or "bad") cholesterol should be a health priority for everyone, including those younger than 40 and those who are not overweight. However, 1 in 4 (25%) incorrectly believe that it does not need to be a concern until someone shows signs or symptoms. Although 89% of adults surveyed agreed it is important for people to know whether or not they have high LDL-C, an overwhelming 92% did not know their LDL-C levels or had never had their cholesterol levels tested. A high 63% had never heard of familial hypercholesterolemia: France had the lowest level of awareness (41%) to Denmark with a high 80%, and the association of the disease with high levels of LDL-C is quite poor (only 36%), with Sweden only at 22% versus a high in Spain of 54%. A large part of the people participating in the survey were quite uncertain about the modality of transmission for familial hypercholesterolemia in the family. All in all, this survey highlights the need for more information among citizens for the role of cholesterol in determining CVD. PMID:26671304

  11. The hidden crime: human trafficking.

    PubMed

    Clause, Kristen J; Lawler, Kate Byrnes

    2013-01-01

    As the primary contact in the health care system, nurses can play a role in combating this crime and assisting the victims. Assessment for abuse, neglect, trauma, recurrent sexually transmitted infections (STIs) and fear of a controlling partner is critical. Following up on "red flags" and understanding methods of safe questioning can make the difference between slavery and recovery for victims. Nurses must also know the professional referrals in their areas once a potential victim has been identified. This may be a very dangerous undertaking and must be handled by experienced personnel. Referrals to forensic nurses or physicians, domestic violence professionals or law enforcement may be indicated. Initially, a nurse may want to consult with the agency social worker for guidance. Human trafficking is a human rights crime. Unfortunately, it is more prevalent in all types of communities than most people suspect. Nurses can be heroes to the victims through understanding of this crime and vigilance in the assessment and care of all people they encounter in their practices. PMID:24218718

  12. The hidden crime: human trafficking.

    PubMed

    Clause, Kristen J; Lawler, Kate Byrnes

    2013-01-01

    As the primary contact in the health care system, nurses can play a role in combating this crime and assisting the victims. Assessment for abuse, neglect, trauma, recurrent sexually transmitted infections (STIs) and fear of a controlling partner is critical. Following up on "red flags" and understanding methods of safe questioning can make the difference between slavery and recovery for victims. Nurses must also know the professional referrals in their areas once a potential victim has been identified. This may be a very dangerous undertaking and must be handled by experienced personnel. Referrals to forensic nurses or physicians, domestic violence professionals or law enforcement may be indicated. Initially, a nurse may want to consult with the agency social worker for guidance. Human trafficking is a human rights crime. Unfortunately, it is more prevalent in all types of communities than most people suspect. Nurses can be heroes to the victims through understanding of this crime and vigilance in the assessment and care of all people they encounter in their practices. To learn more or to help with this cause, visit the Somaly Mam Foundation at www.somaly.org or the U.S. Department of State at www. state.gov. PMID:23977773

  13. The hidden crime: human trafficking.

    PubMed

    Clause, Kristen J; Lawler, Kate Byrnes

    2013-01-01

    As the primary contact in the health care system, nurses can play a role in combating this crime and assisting the victims. Assessment for abuse, neglect, trauma, recurrent sexually transmitted infections (STIs) and fear of a controlling partner is critical. Following up on "red flags" and understanding methods of safe questioning can make the difference between slavery and recovery for victims. Nurses must also know the professional referrals in their areas once a potential victim has been identified. This may be a very dangerous undertaking and must be handled by experienced personnel. Referrals to forensic nurses or physicians, domestic violence professionals or law enforcement may be indicated. Initially, a nurse may want to consult with the agency social worker for guidance. Human trafficking is a human rights crime. Unfortunately, it is more prevalent in all types of communities than most people suspect. Nurses can be heroes to the victims through understanding of this crime and vigilance in the assessment and care of all people they encounter in their practices. To learn more or to help with this cause, visit the Somaly Mam Foundation at www.somaly.org or the U.S. Department of State at www. state.gov.

  14. The hidden crime: human trafficking.

    PubMed

    Clause, Kristen J; Lawler, Kate Byrnes

    2013-01-01

    As the primary contact in the health care system, nurses can play a role in combating this crime and assisting the victims. Assessment for abuse, neglect, trauma, recurrent sexually transmitted infections (STIs) and fear of a controlling partner is critical. Following up on "red flags" and understanding methods of safe questioning can make the difference between slavery and recovery for victims. Nurses must also know the professional referrals in their areas once a potential victim has been identified. This may be a very dangerous undertaking and must be handled by experienced personnel. Referrals to forensic nurses or physicians, domestic violence professionals or law enforcement may be indicated. Initially, a nurse may want to consult with the agency social worker for guidance. Human trafficking is a human rights crime. Unfortunately, it is more prevalent in all types of communities than most people suspect. Nurses can be heroes to the victims through understanding of this crime and vigilance in the assessment and care of all people they encounter in their practices.

  15. Lymphatic Regulation of Cellular Trafficking

    PubMed Central

    Jackson, David G.

    2016-01-01

    Lymphatic vessels play vital roles in immune surveillance and immune regulation by conveying antigen loaded dendritic cells, memory T cells, macrophages and neutrophils from the peripheral tissues to draining lymph nodes where they initiate as well as modify immune responses. Until relatively recently however, there was little understanding of how entry and migration through lymphatic vessels is organized or the specific molecular mechanisms that might be involved. Within the last decade, the situation has been transformed by an explosion of knowledge generated largely through the application of microscopic imaging, transgenic animals, specific markers and function blocking mAbs that is beginning to provide a rational conceptual framework. This article provides a critical review of the recent literature, highlighting seminal discoveries that have revealed the fascinating ultrastructure of leucocyte entry sites in lymphatic vessels, as well as generating controversies over the involvement of integrin adhesion, chemotactic and haptotactic mechanisms in DC entry under normal and inflamed conditions. It also discusses the major changes in lymphatic architecture that occur during inflammation and the different modes of leucocyte entry and trafficking within inflamed lymphatic vessels, as well as presenting a timely update on the likely role of hyaluronan and the major lymphatic endothelial hyaluronan receptor LYVE-1 in leucocyte transit.

  16. Cholesterol Perturbs Lipid Bilayers Nonuniversally

    SciTech Connect

    Pan Jianjun; Mills, Thalia T.; Tristram-Nagle, Stephanie; Nagle, John F.

    2008-05-16

    Cholesterol is well known to modulate the physical properties of biomembranes. Using modern x-ray scattering methods, we have studied the effects of cholesterol on the bending modulus K{sub C}, the thickness D{sub HH}, and the orientational order parameter S{sub xray} of lipid bilayers. We find that the effects are different for at least three classes of phospholipids characterized by different numbers of saturated hydrocarbon chains. Most strikingly, cholesterol strongly increases K{sub C} when both chains of the phospholipid are fully saturated but not at all when there are two monounsaturated chains.

  17. Targeting cancer using cholesterol conjugates

    PubMed Central

    Radwan, Awwad A.; Alanazi, Fares K.

    2013-01-01

    Conjugation of cholesterol moiety to active compounds for either cancer treatment or diagnosis is an attractive approach. Cholesterol derivatives are widely studied as cancer diagnostic agents and as anticancer derivatives either in vitro or in vivo using animal models. In largely growing studies, anticancer agents have been chemically conjugated to cholesterol molecules, to enhance their pharmacokinetic behavior, cellular uptake, target specificity, and safety. To efficiently deliver anticancer agents to the target cells and tissues, many different cholesterol–anticancer conjugates were synthesized and characterized, and their anticancer efficiencies were tested in vitro and in vivo. PMID:24493968

  18. LDL–cholesterol transport to the endoplasmic reticulum: current concepts

    PubMed Central

    Pfisterer, Simon G.; Peränen, Johan; Ikonen, Elina

    2016-01-01

    Purpose of review In this article, we summarize the present information related to the export of LDL-derived cholesterol from late endosomes, with a focus on Nieman-Pick disease, type C1 (NPC1) cholesterol delivery toward the endoplasmic reticulum (ER). We review data suggesting that several pathways may operate in parallel, including membrane transport routes and membrane contact sites (MCSs). Recent findings There is increasing appreciation that MCSs provide an important mechanism for intermembrane lipid transfer. In late endosome–ER contacts, three protein bridges involving oxysterol binding protein related protein (ORP)1L-vesicle associated membrane protein-associated protein (VAP), steroidogenic acute regulatory protein (StAR)D3-VAP and ORP5-NPC1 proteins have been reported. How much they contribute to the flux of LDL–cholesterol to the ER is currently open. Studies for lipid transfer via MCSs have been most advanced in Saccharomyces cerevisiae. Recently, a new sterol-binding protein family conserved between yeast and man was identified. Its members localize at MCSs and were named lipid transfer protein anchored at membrane contact sites (Lam) proteins. In yeast, sterol transfer between the ER and the yeast lysosome may be facilitated by a Lam protein. Summary Increasing insights into the role of MCSs in directional sterol delivery between membranes propose that they might provide routes for LDL–cholesterol transfer to the ER. Future work should reveal which specific contacts may operate for this, and how they are controlled by cholesterol homeostatic machineries. PMID:27054443

  19. Cholesterol confusion and statin controversy

    PubMed Central

    DuBroff, Robert; de Lorgeril, Michel

    2015-01-01

    The role of blood cholesterol levels in coronary heart disease (CHD) and the true effect of cholesterol-lowering statin drugs are debatable. In particular, whether statins actually decrease cardiac mortality and increase life expectancy is controversial. Concurrently, the Mediterranean diet model has been shown to prolong life and reduce the risk of diabetes, cancer, and CHD. We herein review current data related to both statins and the Mediterranean diet. We conclude that the expectation that CHD could be prevented or eliminated by simply reducing cholesterol appears unfounded. On the contrary, we should acknowledge the inconsistencies of the cholesterol theory and recognize the proven benefits of a healthy lifestyle incorporating a Mediterranean diet to prevent CHD. PMID:26225201

  20. Cholesterol's location in lipid bilayers

    DOE PAGES

    Marquardt, Drew; Kučerka, Norbert; Wassall, Stephen R.; Harroun, Thad A.; Katsaras, John

    2016-04-04

    It is well known that cholesterol modifies the physical properties of lipid bilayers. For example, the much studied liquid-ordered Lo phase contains rapidly diffusing lipids with their acyl chains in the all trans configuration, similar to gel phase bilayers. Moreover, the Lo phase is commonly associated with cholesterol-enriched lipid rafts, which are thought to serve as platforms for signaling proteins in the plasma membrane. Cholesterol's location in lipid bilayers has been studied extensively, and it has been shown – at least in some bilayers – to align differently from its canonical upright orientation, where its hydroxyl group is in themore » vicinity of the lipid–water interface. In this study we review recent works describing cholesterol's location in different model membrane systems with emphasis on results obtained from scattering, spectroscopic and molecular dynamics studies.« less

  1. Parallel pipelining

    SciTech Connect

    Joseph, D.D.; Bai, R.; Liao, T.Y.; Huang, A.; Hu, H.H.

    1995-09-01

    In this paper the authors introduce the idea of parallel pipelining for water lubricated transportation of oil (or other viscous material). A parallel system can have major advantages over a single pipe with respect to the cost of maintenance and continuous operation of the system, to the pressure gradients required to restart a stopped system and to the reduction and even elimination of the fouling of pipe walls in continuous operation. The authors show that the action of capillarity in small pipes is more favorable for restart than in large pipes. In a parallel pipeline system, they estimate the number of small pipes needed to deliver the same oil flux as in one larger pipe as N = (R/r){sup {alpha}}, where r and R are the radii of the small and large pipes, respectively, and {alpha} = 4 or 19/7 when the lubricating water flow is laminar or turbulent.

  2. Formation of cholesterol bilayer domains precedes formation of cholesterol crystals in cholesterol/dimyristoylphosphatidylcholine membranes: EPR and DSC studies.

    PubMed

    Mainali, Laxman; Raguz, Marija; Subczynski, Witold K

    2013-08-01

    Saturation-recovery EPR along with DSC were used to determine the cholesterol content at which pure cholesterol bilayer domains (CBDs) and cholesterol crystals begin to form in dimyristoylphosphatidylcholine (DMPC) membranes. To preserve compositional homogeneity throughout the membrane suspension, lipid multilamellar dispersions were prepared using a rapid solvent exchange method. The cholesterol content increased from 0 to 75 mol %. With spin-labeled cholesterol analogues, it was shown that the CBDs begin to form at ~50 mol % cholesterol. It was confirmed by DSC that the cholesterol solubility threshold for DMPC membranes is detected at ~66 mol % cholesterol. At levels above this cholesterol content, monohydrate cholesterol crystals start to form. The major finding is that the formation of CBDs precedes formation of cholesterol crystals. The region of the phase diagram for cholesterol contents between 50 and 66 mol % is described as a structured one-phase region in which CBDs have to be supported by the surrounding DMPC bilayer saturated with cholesterol. Thus, the phase boundary located at 66 mol % cholesterol separates the structured one-phase region (liquid-ordered phase of DMPC with CBDs) from the two-phase region where the structured liquid-ordered phase of DMPC coexists with cholesterol crystals. It is likely that CBDs are precursors of monohydrate cholesterol crystals.

  3. Venezuelan equine encephalitis virus entry mechanism requires late endosome formation and resists cell membrane cholesterol depletion

    SciTech Connect

    Kolokoltsov, Andrey A.; Fleming, Elisa H.; Davey, Robert A. . E-mail: radavey@utmb.edu

    2006-04-10

    Virus envelope proteins determine receptor utilization and host range. The choice of receptor not only permits specific targeting of cells that express it, but also directs the virus into specific endosomal trafficking pathways. Disrupting trafficking can result in loss of virus infectivity due to redirection of virions to non-productive pathways. Identification of the pathway or pathways used by a virus is, thus, important in understanding virus pathogenesis mechanisms and for developing new treatment strategies. Most of our understanding of alphavirus entry has focused on the Old World alphaviruses, such as Sindbis and Semliki Forest virus. In comparison, very little is known about the entry route taken by more pathogenic New World alphaviruses. Here, we use a novel contents mixing assay to identify the cellular requirements for entry of a New World alphavirus, Venezuelan equine encephalitis virus (VEEV). Expression of dominant negative forms of key endosomal trafficking genes shows that VEEV must access clathrin-dependent endocytic vesicles for membrane fusion to occur. Unexpectedly, the exit point is different from Old World alphaviruses that leave from early endosomes. Instead, VEEV also requires functional late endosomes. Furthermore, unlike the Old World viruses, VEEV entry is insensitive to cholesterol sequestration from cell membranes and may reflect a need to access an endocytic compartment that lacks cholesterol. This indicates fundamental differences in the entry route taken by VEEV compared to Old World alphaviruses.

  4. Cholesterol-dependent cytolysins.

    PubMed

    Gilbert, Robert J C

    2010-01-01

    The cholesterol-dependent cytolysins (CDCs) are part of a large family of pore-forming proteins that include the human proteins perforin and the complement membrane attack complex. The activity of all family members is focused on membranes, but the proteins are themselves involved in a diverse range of phenomena. An overview of some of these phenomena is provided here, along with an historical perspective of CDCs themselves and how our understanding of their mechanism of action has developed over the years. The way in which pore formation depends on specific characteristics of the membrane under attack as well as of the protein doing the attacking is emphasised. The cholesterol-dependent cytolysins (CDCs) have been the focus of a renewed keen research interest for over ten years now. Their importance has been even further enhanced by the homology now identified between them and the membrane attack complex/perforin (MACPF) family of proteins, which includes several components of the complement cascade as well as perforin itself. In this chapter I aim to provide an overview of our understanding of the interaction between CDCs and other members of what is now called the MACPF/CDC superfamily, with their target membranes. CDCs (also in the past known as thiol-activated toxins or cholesterol-binding toxins) were originally identified from four Gram-positive bacterial genera (Clostridium, Listeria, Bacillus and Streptococcus). Well-known examples include listeriolysin, perfringolysin, streptolysin and pneumoysin. Listeriolysin from L. monocytogenes is responsible for the escape of bacteria from the phagosome to colonise the cytoplasm and has been applied as a protein adjuvant in the development of vaccines against cancer and tuberculosis, for example. Perfringolysin from C. perfringens (Fig. 1A) has become perhaps the most studied CDC4 and has an important role in pathology associated with infection (gangrene). Streptolysin from S. pyogenes is another intensely studied

  5. Peptides having reduced toxicity that stimulate cholesterol efflux

    DOEpatents

    Bielicki, John K.; Johansson, Jan; Danho, Waleed

    2016-08-16

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABCA1 that parallels that of full-length apolipoproteins. Further, the peptides of the invention have little or no toxicity when administered at therapeutic and higher doses. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  6. Wheat germ policosanol failed to lower plasma cholesterol in subjects with normal to mildly elevated cholesterol concentrations.

    PubMed

    Lin, Yuguang; Rudrum, Mike; van der Wielen, Reggy P J; Trautwein, Elke A; McNeill, Gerald; Sierksma, Aafje; Meijer, Gert W

    2004-10-01

    Sugar cane policosanol, a mixture of long-chain primary alcohols (approximately 67% as octacosanol), has been reported to lower plasma low-density lipoprotein (LDL)-cholesterol. We investigated the effect of wheat germ policosanol (WGP) on plasma lipid profiles in 58 adults (30 men and 28 women, aged 49 +/- 11 years) with normal to mildly elevated plasma cholesterol concentrations in a double-blind, randomized, parallel placebo-controlled study. Subjects consumed chocolate pellets with or without 20 mg/d WGP for 4 weeks. Plasma lipid concentrations, routine blood chemistry and hematology were determined at the start and the end of the study. The initial plasma total, LDL-cholesterol, high-density lipoprotein (HDL)-cholesterol, and triacylglycerol concentrations in the WGP and the control groups were identical. Over the 4 weeks, neither the WGP nor the control treatment significantly changed plasma total cholesterol, LDL- and HDL-cholesterol, or triacylglycerol concentrations when compared to baseline values. In addition, there was no significant difference in plasma lipid profiles between the WGP and the control groups at the end of the study. WGP did not result in any adverse effects as indicated by plasma activities of L-gamma-glutamyltransferase (gamma-GT), ALT, AST, bilirubin concentrations, and blood cell profiles. Chemical analysis showed that WGP consists of 8% hexacosanol, 67% octacosanol, 12% triacosanol, and 13% other long-chain alcohols, which is similar to the composition of sugar cane policosanol. In conclusion, WGP at 20 mg/d had no beneficial effects on blood lipid profiles. It therefore seems unlikely that the long chain (C24-34) alcohols have any cholesterol-lowering activity.

  7. Facts about...Blood Cholesterol. Revised.

    ERIC Educational Resources Information Center

    National Heart, Lung, and Blood Inst. (DHHS/NIH), Bethesda, MD.

    This fact sheet on blood cholesterol examines the connection between cholesterol and heart disease, lists risk factors for heart disease that can and cannot be controlled, points out who can benefit from lowering blood cholesterol, distinguishes between blood and dietary cholesterol, describes low density lipoprotein and high density lipoprotein…

  8. Multiple Surface Regions on the Niemann-Pick C2 Protein Facilitate Intracellular Cholesterol Transport.

    PubMed

    McCauliff, Leslie A; Xu, Zhi; Li, Ran; Kodukula, Sarala; Ko, Dennis C; Scott, Matthew P; Kahn, Peter C; Storch, Judith

    2015-11-01

    The cholesterol storage disorder Niemann-Pick type C (NPC) disease is caused by defects in either of two late endosomal/lysosomal proteins, NPC1 and NPC2. NPC2 is a 16-kDa soluble protein that binds cholesterol in a 1:1 stoichiometry and can transfer cholesterol between membranes by a mechanism that involves protein-membrane interactions. To examine the structural basis of NPC2 function in cholesterol trafficking, a series of point mutations were generated across the surface of the protein. Several NPC2 mutants exhibited deficient sterol transport properties in a set of fluorescence-based assays. Notably, these mutants were also unable to promote egress of accumulated intracellular cholesterol from npc2(-/-) fibroblasts. The mutations mapped to several regions on the protein surface, suggesting that NPC2 can bind to more than one membrane simultaneously. Indeed, we have previously demonstrated that WT NPC2 promotes vesicle-vesicle interactions. These interactions were abrogated, however, by mutations causing defective sterol transfer properties. Molecular modeling shows that NPC2 is highly plastic, with several intense positively charged regions across the surface that could interact favorably with negatively charged membrane phospholipids. The point mutations generated in this study caused changes in NPC2 surface charge distribution with minimal conformational changes. The plasticity, coupled with membrane flexibility, probably allows for multiple cholesterol transfer routes. Thus, we hypothesize that, in part, NPC2 rapidly traffics cholesterol between closely appositioned membranes within the multilamellar interior of late endosomal/lysosomal proteins, ultimately effecting cholesterol egress from this compartment.

  9. Multiple Surface Regions on the Niemann-Pick C2 Protein Facilitate Intracellular Cholesterol Transport.

    PubMed

    McCauliff, Leslie A; Xu, Zhi; Li, Ran; Kodukula, Sarala; Ko, Dennis C; Scott, Matthew P; Kahn, Peter C; Storch, Judith

    2015-11-01

    The cholesterol storage disorder Niemann-Pick type C (NPC) disease is caused by defects in either of two late endosomal/lysosomal proteins, NPC1 and NPC2. NPC2 is a 16-kDa soluble protein that binds cholesterol in a 1:1 stoichiometry and can transfer cholesterol between membranes by a mechanism that involves protein-membrane interactions. To examine the structural basis of NPC2 function in cholesterol trafficking, a series of point mutations were generated across the surface of the protein. Several NPC2 mutants exhibited deficient sterol transport properties in a set of fluorescence-based assays. Notably, these mutants were also unable to promote egress of accumulated intracellular cholesterol from npc2(-/-) fibroblasts. The mutations mapped to several regions on the protein surface, suggesting that NPC2 can bind to more than one membrane simultaneously. Indeed, we have previously demonstrated that WT NPC2 promotes vesicle-vesicle interactions. These interactions were abrogated, however, by mutations causing defective sterol transfer properties. Molecular modeling shows that NPC2 is highly plastic, with several intense positively charged regions across the surface that could interact favorably with negatively charged membrane phospholipids. The point mutations generated in this study caused changes in NPC2 surface charge distribution with minimal conformational changes. The plasticity, coupled with membrane flexibility, probably allows for multiple cholesterol transfer routes. Thus, we hypothesize that, in part, NPC2 rapidly traffics cholesterol between closely appositioned membranes within the multilamellar interior of late endosomal/lysosomal proteins, ultimately effecting cholesterol egress from this compartment. PMID:26296895

  10. Intestinal nuclear receptors in HDL cholesterol metabolism

    PubMed Central

    Degirolamo, Chiara; Sabbà, Carlo; Moschetta, Antonio

    2015-01-01

    The intestine plays a pivotal role in cholesterol homeostasis by functioning as an absorptive and secretory organ in the reverse cholesterol transport pathway. Enterocytes control cholesterol absorption, apoAI synthesis, HDL biogenesis, and nonbiliary cholesterol fecal disposal. Thus, intestine-based therapeutic interventions may hold promise in the management of diseases driven by cholesterol overload. Lipid-sensing nuclear receptors (NRs) are highly expressed in the intestinal epithelium and regulate transcriptionally the handling of cholesterol by the enterocytes. Here, we discuss the NR regulation of cholesterol fluxes across the enterocytes with special emphasis on NR exploitation as a bona fide novel HDL-raising strategy. PMID:25070952

  11. Drosophila CK1-γ, gilgamesh, controls PCP-mediated morphogenesis through regulation of vesicle trafficking

    PubMed Central

    Gault, William J.; Olguin, Patricio; Weber, Ursula

    2012-01-01

    Cellular morphogenesis, including polarized outgrowth, promotes tissue shape and function. Polarized vesicle trafficking has emerged as a fundamental mechanism by which protein and membrane can be targeted to discrete subcellular domains to promote localized protrusions. Frizzled (Fz)/planar cell polarity (PCP) signaling orchestrates cytoskeletal polarization and drives morphogenetic changes in such contexts as the vertebrate body axis and external Drosophila melanogaster tissues. Although regulation of Fz/PCP signaling via vesicle trafficking has been identified, the interplay between the vesicle trafficking machinery and downstream terminal PCP-directed processes is less established. In this paper, we show that Drosophila CK1-γ/gilgamesh (gish) regulates the PCP-associated process of trichome formation through effects on Rab11-mediated vesicle recycling. Although the core Fz/PCP proteins dictate prehair formation broadly, CK1-γ/gish restricts nucleation to a single site. Moreover, CK1-γ/gish works in parallel with the Fz/PCP effector multiple wing hairs, which restricts prehair formation along the perpendicular axis to Gish. Our findings suggest that polarized Rab11-mediated vesicle trafficking regulated by CK1-γ is required for PCP-directed processes. PMID:22391037

  12. Drosophila CK1-γ, gilgamesh, controls PCP-mediated morphogenesis through regulation of vesicle trafficking.

    PubMed

    Gault, William J; Olguin, Patricio; Weber, Ursula; Mlodzik, Marek

    2012-03-01

    Cellular morphogenesis, including polarized outgrowth, promotes tissue shape and function. Polarized vesicle trafficking has emerged as a fundamental mechanism by which protein and membrane can be targeted to discrete subcellular domains to promote localized protrusions. Frizzled (Fz)/planar cell polarity (PCP) signaling orchestrates cytoskeletal polarization and drives morphogenetic changes in such contexts as the vertebrate body axis and external Drosophila melanogaster tissues. Although regulation of Fz/PCP signaling via vesicle trafficking has been identified, the interplay between the vesicle trafficking machinery and downstream terminal PCP-directed processes is less established. In this paper, we show that Drosophila CK1-γ/gilgamesh (gish) regulates the PCP-associated process of trichome formation through effects on Rab11-mediated vesicle recycling. Although the core Fz/PCP proteins dictate prehair formation broadly, CK1-γ/gish restricts nucleation to a single site. Moreover, CK1-γ/gish works in parallel with the Fz/PCP effector multiple wing hairs, which restricts prehair formation along the perpendicular axis to Gish. Our findings suggest that polarized Rab11-mediated vesicle trafficking regulated by CK1-γ is required for PCP-directed processes. PMID:22391037

  13. [Role of HDL in Cholesterol Efflux and Reverse Cholesterol Transport].

    PubMed

    Ayaori, Makoto

    2016-01-01

    Low plasma levels of HDL-cholesterol (HDL-C) have been consistently associated with an increased risk of atherosclerotic cardiovascular diseases (CVD), and it is thus considered to be an anti-atherogenic lipoprotein. The development of novel therapies to enhance the atheroprotective properties of HDL may have the potential to further reduce the residual risk. Reverse cholesterol transport (RCT) is believed to be a primary atheroprotective property of HDL and its major protein, apolipoprotein A-I(apoA-I). HDL and apoA-I have been shown to promote the efflux of excess cholesterol from macrophage-derived foam cells via the cholesterol transporters, ATP-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B, type I (SR-BI), and then transport it back to the liver for excretion into bile and eventually into the feces. In this regard, a validated murine assay that quantifies macrophage RCT may be a better predictor of atherosclerosis than the steady-state plasma concentration of HDL-C. Indeed, a recent clinical study demonstrated that the ability of serum HDL to mediate cholesterol efflux from macrophages was independently and negatively associated with the CVD risk even after adjustment for HDL-C levels, suggesting that HDL functionality is more important than its quantity. Therefore, the future development of HDL-targeted therapy should take both aspects into consideration to further reduce the residual risk.

  14. [Role of HDL in Cholesterol Efflux and Reverse Cholesterol Transport].

    PubMed

    Ayaori, Makoto

    2016-01-01

    Low plasma levels of HDL-cholesterol (HDL-C) have been consistently associated with an increased risk of atherosclerotic cardiovascular diseases (CVD), and it is thus considered to be an anti-atherogenic lipoprotein. The development of novel therapies to enhance the atheroprotective properties of HDL may have the potential to further reduce the residual risk. Reverse cholesterol transport (RCT) is believed to be a primary atheroprotective property of HDL and its major protein, apolipoprotein A-I(apoA-I). HDL and apoA-I have been shown to promote the efflux of excess cholesterol from macrophage-derived foam cells via the cholesterol transporters, ATP-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B, type I (SR-BI), and then transport it back to the liver for excretion into bile and eventually into the feces. In this regard, a validated murine assay that quantifies macrophage RCT may be a better predictor of atherosclerosis than the steady-state plasma concentration of HDL-C. Indeed, a recent clinical study demonstrated that the ability of serum HDL to mediate cholesterol efflux from macrophages was independently and negatively associated with the CVD risk even after adjustment for HDL-C levels, suggesting that HDL functionality is more important than its quantity. Therefore, the future development of HDL-targeted therapy should take both aspects into consideration to further reduce the residual risk. PMID:27192798

  15. Heterogeneity of cholesterol homeostasis in man. Response to changes in dietary fat quality and cholesterol quantity.

    PubMed Central

    McNamara, D J; Kolb, R; Parker, T S; Batwin, H; Samuel, P; Brown, C D; Ahrens, E H

    1987-01-01

    Studies were carried out to examine the effects of dietary fat and cholesterol on cholesterol homeostasis in man. 75 12-wk studies were carried out during intake of 35% of calories as either saturated or polyunsaturated fat, first low and then high in dietary cholesterol. Dietary fat and cholesterol intakes, plasma lipid and lipoprotein levels, cholesterol absorption and sterol synthesis in isolated blood mononuclear leukocytes were measured during each diet period. In 69% of the studies the subjects compensated for the increased cholesterol intake by decreasing cholesterol fractional absorption and/or endogenous cholesterol synthesis. When an increase in plasma cholesterol levels was observed there was a failure to suppress endogenous cholesterol synthesis. Plasma cholesterol levels were more sensitive to dietary fat quality than to cholesterol quantity. The results demonstrate that the responses to dietary cholesterol and fat are highly individualized and that most individuals have effective feedback control mechanisms. PMID:3584466

  16. ACTIVATING PERIPHERAL ARTERIAL DISEASE PATIENTS TO REDUCE CHOLESTEROL: A RANDOMIZED TRIAL

    PubMed Central

    McDermott, Mary M.; Reed, George; Greenland, Philip; Mazor, Kathy M.; Pagoto, Sherry; Ockene, Judith K.; Graff, Rex; Merriam, Philip A.; Leung, Kathy; Manheim, Larry; Kibbe, Melina R.; Olendzki, Barbara; Pearce, William H.; Ockene, Ira S.

    2011-01-01

    Background Peripheral arterial disease patients are less likely than other high-risk patients to achieve ideal low density lipoprotein cholesterol (LDL-cholesterol) levels. This randomized controlled trial assessed whether a telephone counseling intervention, designed to help peripheral arterial disease patients request more intensive cholesterol lowering therapy from their physician, achieves lower LDL-cholesterol levels than two control conditions. Methods 355 peripheral arterial disease participants with baseline LDL-cholesterol ≥ 70 mg/dl were enrolled. The primary outcome was change in LDL-cholesterol level at twelve-month follow-up. There were three parallel arms: telephone counseling intervention, attention control condition, and usual care. The intervention consisted of patient-centered counseling, delivered every six weeks, encouraging participants to request increases in cholesterol-lowering therapy from their physician. The attention control condition consisted of telephone calls every six weeks providing information only. The usual care condition participated in baseline and follow-up testing. Results At 12-month follow-up, participants in the intervention improved their LDL-cholesterol level, compared to those in attention control (−18.4 mg/dl vs. −6.8 mg/dl, p= 0.010) but not compared to those in usual care (−18.4 mg/dl vs. −11.1 mg/dl, p= 0.208). Intervention participants were more likely to start a cholesterol-lowering medication or increase their cholesterol-lowering medication dose than those in the attention control (54% vs. 18%, p=0.001) and usual care (54% vs. 31%, P<0.001) conditions. Conclusion Telephone counseling that helped peripheral arterial disease patients request more intensive cholesterol-lowering therapy from their physician achieved greater LDL-cholesterol declines than an attention control arm that provided health information alone. PMID:21605733

  17. Differences in synthesis and absorption of cholesterol of two effective lipid-lowering therapies

    PubMed Central

    Kasmas, S.H.; Izar, M.C.; França, C.N.; Ramos, S.C.; Moreira, F.T.; Helfenstein, T.; Moreno, R.A.; Borges, N.C.; Figueiredo-Neto, A.M.; Fonseca, F.A.

    2012-01-01

    Effective statin therapy is associated with a marked reduction of cardiovascular events. However, the explanation for full benefits obtained for LDL cholesterol targets by combined lipid-lowering therapy is controversial. Our study compared the effects of two equally effective lipid-lowering strategies on markers of cholesterol synthesis and absorption. A prospective, open label, randomized, parallel design study, with blinded endpoints, included 116 subjects. We compared the effects of a 12-week treatment with 40 mg rosuvastatin or the combination of 40 mg simvastatin/10 mg ezetimibe on markers of cholesterol absorption (campesterol and β-sitosterol), synthesis (desmosterol), and their ratios to cholesterol. Both therapies similarly decreased total and LDL cholesterol, triglycerides and apolipoprotein B, and increased apolipoprotein A1 (P < 0.05 vs baseline for all). Simvastatin/ezetimibe increased plasma desmosterol (P = 0.012 vs baseline), and decreased campesterol and β-sitosterol (P < 0.0001 vs baseline for both), with higher desmosterol (P = 0.007) and lower campesterol and β-sitosterol compared to rosuvastatin, (P < 0.0001, for both). In addition, rosuvastatin increased the ratios of these markers to cholesterol (P < 0.002 vs baseline for all), whereas simvastatin/ezetimibe significantly decreased the campesterol/cholesterol ratio (P = 0.008 vs baseline) and tripled the desmosterol/cholesterol ratio (P < 0.0001 vs baseline). The campesterol/cholesterol and β-sitosterol/cholesterol ratios were lower, whereas the desmosterol/cholesterol ratio was higher in patients receiving simvastatin/ezetimibe (P < 0.0001 vs rosuvastatin, for all). Pronounced differences in markers of cholesterol absorption and synthesis were observed between two equally effective lipid-lowering strategies. PMID:22801416

  18. Trafficking vesicles: pro or contra pathogens?

    PubMed

    Frei dit Frey, Nicolas; Robatzek, Silke

    2009-08-01

    Membrane compartmentalization and trafficking are pivotal for eukaryotic life and demand a higher order of coordination. Even in their resting state, most plant cells exhibit a polarized localization of membrane compartments, which is redirected when plant cells are attacked by microbes. Repositioning of organelles at pathogen penetration sites has been reported since more than a decade; however, only recently has targeted vesicle trafficking upon biotic stress emerged. It has become evident that vesicle secretion and endocytic pathways are engaged in the plant's immune system to actively defend against potential pathogens. By contrast, invasive pathogens have evolved means to utilize these trafficking pathways for the suppression of plant defenses and to the benefit of microbial proliferation. This review summarizes recent findings of host intracellular endomembrane adaptations in response to pathogens and how pathogens exploit them. PMID:19608452

  19. Vesicle trafficking and cell surface membrane patchiness.

    PubMed

    Tang, Q; Edidin, M

    2001-07-01

    Membrane proteins and lipids often appear to be distributed in patches on the cell surface. These patches are often assumed to be membrane domains, arising from specific molecular associations. However, a computer simulation (Gheber and Edidin, 1999) shows that membrane patchiness may result from a combination of vesicle trafficking and dynamic barriers to lateral mobility. The simulation predicts that the steady-state patches of proteins and lipids seen on the cell surface will decay if vesicle trafficking is inhibited. To test this prediction, we compared the apparent sizes and intensities of patches of class I HLA molecules, integral membrane proteins, before and after inhibiting endocytic vesicle traffic from the cell surface, either by incubation in hypertonic medium or by expression of a dominant-negative mutant dynamin. As predicted by the simulation, the apparent sizes of HLA patches increased, whereas their intensities decreased after endocytosis and vesicle trafficking were inhibited. PMID:11423406

  20. Purinergic Signaling During Immune Cell Trafficking.

    PubMed

    Ferrari, Davide; McNamee, Eóin N; Idzko, Marco; Gambari, Roberto; Eltzschig, Holger K

    2016-06-01

    Migration and positioning of immune cells is fundamental for their differentiation and recruitment at sites of infection. Besides the fundamental role played by chemokines and their receptors, recent studies demonstrate that a complex network of purinergic signaling events plays a key role in these trafficking events. This process includes the release of nucleotides (such as ATP and ADP) and subsequent autocrine and paracrine signaling events through nucleotide receptors. At the same time, surface-expressed ectoapyrases and nucleotidases convert extracellular nucleotides to adenosine, and adenosine signaling events play additional functional roles in leucocyte trafficking. In this review we revisit classical paradigms of inflammatory cell trafficking in the context of recent studies implicating purinergic signaling events in this process. PMID:27142306

  1. Statins increase hepatic cholesterol synthesis and stimulate fecal cholesterol elimination in mice.

    PubMed

    Schonewille, Marleen; Freark de Boer, Jan; Mele, Laura; Wolters, Henk; Bloks, Vincent W; Wolters, Justina C; Kuivenhoven, Jan A; Tietge, Uwe J F; Brufau, Gemma; Groen, Albert K

    2016-08-01

    Statins are competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme of cholesterol synthesis. Statins reduce plasma cholesterol levels, but whether this is actually caused by inhibition of de novo cholesterol synthesis has not been clearly established. Using three different statins, we investigated the effects on cholesterol metabolism in mice in detail. Surprisingly, direct measurement of whole body cholesterol synthesis revealed that cholesterol synthesis was robustly increased in statin-treated mice. Measurement of organ-specific cholesterol synthesis demonstrated that the liver is predominantly responsible for the increase in cholesterol synthesis. Excess synthesized cholesterol did not accumulate in the plasma, as plasma cholesterol decreased. However, statin treatment led to an increase in cholesterol removal via the feces. Interestingly, enhanced cholesterol excretion in response to rosuvastatin and lovastatin treatment was mainly mediated via biliary cholesterol secretion, whereas atorvastatin mainly stimulated cholesterol removal via the transintestinal cholesterol excretion pathway. Moreover, we show that plasma cholesterol precursor levels do not reflect cholesterol synthesis rates during statin treatment in mice. In conclusion, cholesterol synthesis is paradoxically increased upon statin treatment in mice. However, statins potently stimulate the excretion of cholesterol from the body, which sheds new light on possible mechanisms underlying the cholesterol-lowering effects of statins.

  2. Statins increase hepatic cholesterol synthesis and stimulate fecal cholesterol elimination in mice.

    PubMed

    Schonewille, Marleen; Freark de Boer, Jan; Mele, Laura; Wolters, Henk; Bloks, Vincent W; Wolters, Justina C; Kuivenhoven, Jan A; Tietge, Uwe J F; Brufau, Gemma; Groen, Albert K

    2016-08-01

    Statins are competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme of cholesterol synthesis. Statins reduce plasma cholesterol levels, but whether this is actually caused by inhibition of de novo cholesterol synthesis has not been clearly established. Using three different statins, we investigated the effects on cholesterol metabolism in mice in detail. Surprisingly, direct measurement of whole body cholesterol synthesis revealed that cholesterol synthesis was robustly increased in statin-treated mice. Measurement of organ-specific cholesterol synthesis demonstrated that the liver is predominantly responsible for the increase in cholesterol synthesis. Excess synthesized cholesterol did not accumulate in the plasma, as plasma cholesterol decreased. However, statin treatment led to an increase in cholesterol removal via the feces. Interestingly, enhanced cholesterol excretion in response to rosuvastatin and lovastatin treatment was mainly mediated via biliary cholesterol secretion, whereas atorvastatin mainly stimulated cholesterol removal via the transintestinal cholesterol excretion pathway. Moreover, we show that plasma cholesterol precursor levels do not reflect cholesterol synthesis rates during statin treatment in mice. In conclusion, cholesterol synthesis is paradoxically increased upon statin treatment in mice. However, statins potently stimulate the excretion of cholesterol from the body, which sheds new light on possible mechanisms underlying the cholesterol-lowering effects of statins. PMID:27313057

  3. Trafficking in persons and development: towards greater policy coherence.

    PubMed

    Danailova-Trainor, Gergana; Laczko, Frank

    2010-01-01

    Poverty is often regarded as the "root cause" of trafficking, but the linkages between poverty, a lack of development and trafficking are complex. For example, there is some evidence to suggest that victims of cross-border trafficking are more likely to originate from middle-income rather than lower-income countries. Trafficking and development have tended to be treated as very separate policy areas and the assessment of the development impact of counter-trafficking programmes is still at an early stage. This paper outlines a possible framework for a more evidence-based approach to understanding the linkages between trafficking, trafficking policy and human development. The paper argues that the human development gains from greater mobility could be significantly enhanced if there was greater coherence between policies to combat trafficking and policies to promote development. PMID:20645470

  4. 31 CFR 536.312 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... designated narcotics trafficker means: (a) Persons listed in the annex to Executive Order 12978 (3 CFR, 1995... international narcotics trafficking centered in Colombia; or (2) Materially to assist in, or provide...

  5. Genome-wide identification of microRNAs regulating cholesterol and triglyceride homeostasis

    PubMed Central

    Wagschal, Alexandre; Najafi-Shoushtari, S Hani; Wang, Lifeng; Goedeke, Leigh; Sinha, Sumita; deLemos, Andrew S; Black, Josh C; Ramírez, Cristina M; Li, Yingxia; Tewhey, Ryan; Hatoum, Ida; Shah, Naisha; Lu, Yong; Kristo, Fjoralba; Psychogios, Nikolaos; Vrbanac, Vladimir; Lu, Yi-Chien; Hla, Timothy; de Cabo, Rafael; Tsang, John S; Schadt, Eric; Sabeti, Pardis C; Kathiresan, Sekar; Cohen, David E; Whetstine, Johnathan; Chung, Raymond T; Fernández-Hernando, Carlos; Kaplan, Lee M; Bernards, Andre; Gerszten, Robert E; Näär, Anders M

    2016-01-01

    Genome-wide association studies (GWASs) have linked genes to various pathological traits. However, the potential contribution of regulatory noncoding RNAs, such as microRNAs (miRNAs), to a genetic predisposition to pathological conditions has remained unclear. We leveraged GWAS meta-analysis data from >188,000 individuals to identify 69 miRNAs in physical proximity to single-nucleotide polymorphisms (SNPs) associated with abnormal levels of circulating lipids. Several of these miRNAs (miR-128-1, miR-148a, miR-130b, and miR-301b) control the expression of key proteins involved in cholesterol-lipoprotein trafficking, such as the low-density lipoprotein (LDL) receptor (LDLR) and the ATP-binding cassette A1 (ABCA1) cholesterol transporter. Consistent with human liver expression data and genetic links to abnormal blood lipid levels, overexpression and antisense targeting of miR-128-1 or miR-148a in high-fat diet–fed C57BL/6J and Apoe-null mice resulted in altered hepatic expression of proteins involved in lipid trafficking and metabolism, and in modulated levels of circulating lipoprotein-cholesterol and triglycerides. Taken together, these findings support the notion that altered expression of miRNAs may contribute to abnormal blood lipid levels, predisposing individuals to human cardiometabolic disorders. PMID:26501192

  6. Human telomerase: biogenesis, trafficking, recruitment, and activation.

    PubMed

    Schmidt, Jens C; Cech, Thomas R

    2015-06-01

    Telomerase is the ribonucleoprotein enzyme that catalyzes the extension of telomeric DNA in eukaryotes. Recent work has begun to reveal key aspects of the assembly of the human telomerase complex, its intracellular trafficking involving Cajal bodies, and its recruitment to telomeres. Once telomerase has been recruited to the telomere, it appears to undergo a separate activation step, which may include an increase in its repeat addition processivity. This review covers human telomerase biogenesis, trafficking, and activation, comparing key aspects with the analogous events in other species.

  7. Homeostatic plasticity and NMDA receptor trafficking.

    PubMed

    Pérez-Otaño, Isabel; Ehlers, Michael D

    2005-05-01

    Learning, memory and brain development are associated with long-lasting modifications of synapses that are guided by specific patterns of neuronal activity. Such modifications include classical Hebbian plasticities (such as long-term potentiation and long-term depression), which are rapid and synapse-specific, and others, such as synaptic scaling and metaplasticity, that work over longer timescales and are crucial for maintaining and orchestrating neuronal network function. The cellular mechanisms underlying Hebbian plasticity have been well studied and involve rapid changes in the trafficking of highly mobile AMPA receptors. An emerging concept is that activity-dependent alterations in NMDA receptor trafficking contribute to homeostatic plasticity at central glutamatergic synapses.

  8. RADIOAUTOGRAPHY OF CHOLESTEROL IN LUNG

    PubMed Central

    Darrah, Hilary K.; Hedley-Whyte, John; Hedley-Whyte, E. Tessa

    1971-01-01

    30 Swiss albino mice aged 8 days were injected intraperitoneally with 0.2 ml of a solution of 4% N,N-dimethyl-formamide in 5% dextrose in water containing cholesterol-1,2-3H (∼1 mCi/ml). Lung tissue was embedded in an Epon mixture after either acetone and propylene oxide dehydration, partial ethanol and Epon 812 dehydration, or the precipitation of cholesterol by digitonin succeeded by partial dehydration. The distribution of cholesterol-1,2-3H in lung parenchyma in 1µ Epon section radioautograms was compared with that in frozen section radioautograms and was found to be independent of the manner of tissue processing. Grain distribution in the tissue was essentially the same whether 16, 63, 93, or 100% radioactivity was retained in the lung. However, grain distribution in the alveolar spaces differed, presumably due to displacement of pulmonary surfactant, which contains cholesterol. Intracellular distribution of cholesterol, in electron microscope radioautograms, was the same with either 51% or 93% retention of radioactivity in the lung. Loss of radioactivity into the various processing solutions was monitored. The various processing techniques have different drawbacks. PMID:19866763

  9. Dietary cholesterol supplementation to a plant-based diet suppresses the complete pathway of cholesterol synthesis and induces bile acid production in Atlantic salmon (Salmo salar L.).

    PubMed

    Kortner, Trond M; Björkhem, Ingemar; Krasnov, Aleksei; Timmerhaus, Gerrit; Krogdahl, Åshild

    2014-06-28

    Plants now supply more than 50 % of protein in Norwegian salmon aquafeeds. The inclusion of plant protein in aquafeeds may be associated with decreased lipid digestibility and cholesterol and bile salt levels, indicating that the replacement of fishmeal with plant protein could result in inadequate supplies of cholesterol in fish. A reduction in feed efficiency, fish growth and pathogen resistance is often observed in parallel to alterations in sterol metabolism. Previous studies have indicated that the negative effects induced by plant components can be attenuated when diets are supplemented with cholesterol. The present study evaluated the effects of dietary cholesterol supplementation (1·5 %) in Atlantic salmon fed a plant-based diet for 77 d. The weights of body, intestines and liver were recorded and blood, tissues, faeces, chyme and bile were sampled for the evaluation of effects on growth, nutrient utilisation and metabolism, and transcriptome and metabolite levels, with particular emphasis on sterol metabolism and organ structure and function. Cholesterol supplementation did not affect the growth or organ weights of Atlantic salmon, but seemed to promote the induction of cholesterol and plant sterol efflux in the intestine while suppressing sterol uptake. Cholesterol biosynthesis decreased correspondingly and conversion into bile acids increased. The marked effect of cholesterol supplementation on bile acid synthesis suggests that dietary cholesterol can be used to increase bile acid synthesis in fish. The present study clearly demonstrated how Atlantic salmon adjusted their metabolic functions in response to the dietary load of cholesterol. It has also expanded our understanding of sterol metabolism and turnover, adding to the existing, rather sparse, knowledge of these processes in fish.

  10. Dietary cholesterol supplementation to a plant-based diet suppresses the complete pathway of cholesterol synthesis and induces bile acid production in Atlantic salmon (Salmo salar L.).

    PubMed

    Kortner, Trond M; Björkhem, Ingemar; Krasnov, Aleksei; Timmerhaus, Gerrit; Krogdahl, Åshild

    2014-06-28

    Plants now supply more than 50 % of protein in Norwegian salmon aquafeeds. The inclusion of plant protein in aquafeeds may be associated with decreased lipid digestibility and cholesterol and bile salt levels, indicating that the replacement of fishmeal with plant protein could result in inadequate supplies of cholesterol in fish. A reduction in feed efficiency, fish growth and pathogen resistance is often observed in parallel to alterations in sterol metabolism. Previous studies have indicated that the negative effects induced by plant components can be attenuated when diets are supplemented with cholesterol. The present study evaluated the effects of dietary cholesterol supplementation (1·5 %) in Atlantic salmon fed a plant-based diet for 77 d. The weights of body, intestines and liver were recorded and blood, tissues, faeces, chyme and bile were sampled for the evaluation of effects on growth, nutrient utilisation and metabolism, and transcriptome and metabolite levels, with particular emphasis on sterol metabolism and organ structure and function. Cholesterol supplementation did not affect the growth or organ weights of Atlantic salmon, but seemed to promote the induction of cholesterol and plant sterol efflux in the intestine while suppressing sterol uptake. Cholesterol biosynthesis decreased correspondingly and conversion into bile acids increased. The marked effect of cholesterol supplementation on bile acid synthesis suggests that dietary cholesterol can be used to increase bile acid synthesis in fish. The present study clearly demonstrated how Atlantic salmon adjusted their metabolic functions in response to the dietary load of cholesterol. It has also expanded our understanding of sterol metabolism and turnover, adding to the existing, rather sparse, knowledge of these processes in fish. PMID:24635969

  11. Child organ trafficking: global reality and inadequate international response.

    PubMed

    Bagheri, Alireza

    2016-06-01

    In organ transplantation, the demand for human organs has grown far faster than the supply of organs. This has opened the door for illegal organ trade and trafficking including from children. Organized crime groups and individual organ brokers exploit the situation and, as a result, black markets are becoming more numerous and organized organ trafficking is expanding worldwide. While underprivileged and vulnerable men and women in developing countries are a major source of trafficked organs, and may themselves be trafficked for the purpose of illegal organ removal and trade, children are at especial risk of exploitation. With the confirmed cases of children being trafficked for their organs, child organ trafficking, which once called a "modern urban legend", is a sad reality in today's world. By presenting a global picture of child organ trafficking, this paper emphasizes that child organ trafficking is no longer a myth but a reality which has to be addressed. It argues that the international efforts against organ trafficking and trafficking in human beings for organ removal have failed to address child organ trafficking adequately. This chapter suggests that more orchestrated international collaboration as well as development of preventive measure and legally binding documents are needed to fight child organ trafficking and to support its victims. PMID:26612382

  12. 78 FR 70571 - Advisory Council on Wildlife Trafficking; Rescheduled Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Fish and Wildlife Service Advisory Council on Wildlife Trafficking; Rescheduled Meeting AGENCY: Fish... Service (Service), announce a public meeting of the Advisory Council on Wildlife Trafficking (Council... announce that the Advisory Council on Wildlife Trafficking (Council) will hold a meeting to...

  13. 48 CFR 52.222-50 - Combating Trafficking in Persons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Combating Trafficking in....222-50 Combating Trafficking in Persons. As prescribed in 22.1705(a), insert the following clause: Combating Trafficking in Persons (FEB 2009) (a) Definitions. As used in this clause— Coercion means—...

  14. Child organ trafficking: global reality and inadequate international response.

    PubMed

    Bagheri, Alireza

    2016-06-01

    In organ transplantation, the demand for human organs has grown far faster than the supply of organs. This has opened the door for illegal organ trade and trafficking including from children. Organized crime groups and individual organ brokers exploit the situation and, as a result, black markets are becoming more numerous and organized organ trafficking is expanding worldwide. While underprivileged and vulnerable men and women in developing countries are a major source of trafficked organs, and may themselves be trafficked for the purpose of illegal organ removal and trade, children are at especial risk of exploitation. With the confirmed cases of children being trafficked for their organs, child organ trafficking, which once called a "modern urban legend", is a sad reality in today's world. By presenting a global picture of child organ trafficking, this paper emphasizes that child organ trafficking is no longer a myth but a reality which has to be addressed. It argues that the international efforts against organ trafficking and trafficking in human beings for organ removal have failed to address child organ trafficking adequately. This chapter suggests that more orchestrated international collaboration as well as development of preventive measure and legally binding documents are needed to fight child organ trafficking and to support its victims.

  15. Human Trafficking: A Review for Mental Health Professionals

    ERIC Educational Resources Information Center

    Yakushko, Oksana

    2009-01-01

    This article provides a review of current research on human trafficking for mental health practitioners and scholars. In addition to an overview of definitions, causes and processes of trafficking, the article highlights mental health consequences of trafficking along with suggestions for treatment of survivors. Directions for counseling services,…

  16. Trafficking of Children in Albania: Patterns of Recruitment and Reintegration

    ERIC Educational Resources Information Center

    Gjermeni, Eglantina; Van Hook, Mary P.; Gjipali, Saemira; Xhillari, Lindita; Lungu, Fatjon; Hazizi, Anila

    2008-01-01

    Problem: Many children in Albania and other countries of Eastern Europe are being trafficked as part of the global business of human trafficking. Objectives: The study sought to identify the patterns of child trafficking involving Albanian children, and especially children's views of the role of family issues and the nature of the trafficking…

  17. Oxidative stress inhibits caveolin-1 palmitoylation and trafficking in endothelial cells

    NASA Technical Reports Server (NTRS)

    Parat, Marie-Odile; Stachowicz, Rafal Z.; Fox, Paul L.

    2002-01-01

    During normal and pathological conditions, endothelial cells (ECs) are subjected to locally generated reactive oxygen species, produced by themselves or by other vessel wall cells. In excess these molecules cause oxidative injury to the cell but at moderate levels they might modulate intracellular signalling pathways. We have investigated the effect of oxidative stress on the palmitoylation and trafficking of caveolin-1 in bovine aortic ECs. Exogenous H2O2 did not alter the intracellular localization of caveolin-1 in ECs. However, metabolic labelling experiments showed that H2O2 inhibited the trafficking of newly synthesized caveolin-1 to membrane raft domains. Several mechanisms potentially responsible for this inhibition were examined. Impairment of caveolin-1 synthesis by H2O2 was not responsible for diminished trafficking. Similarly, the inhibition was independent of H2O2-induced caveolin-1 phosphorylation as shown by the markedly different concentration dependences. We tested the effect of H2O2 on palmitoylation of caveolin-1 by the incorporation of [3H]palmitic acid. Exposure of ECs to H2O2 markedly inhibited the palmitoylation of caveolin-1. Comparable inhibition was observed after treatment of cells with H2O2 delivered either as a bolus or by continuous delivery with glucose and glucose oxidase. Kinetic studies showed that H2O2 did not alter the rate of caveolin-1 depalmitoylation but instead decreased the 'on-rate' of palmitoylation. Together these results show for the first time the modulation of protein palmitoylation by oxidative stress, and suggest a cellular mechanism by which stress might influence caveolin-1-dependent cell activities such as the concentration of signalling proteins and cholesterol trafficking.

  18. Cholesterol Flux Is Required for Endosomal Progression of African Swine Fever Virions during the Initial Establishment of Infection

    PubMed Central

    Cuesta-Geijo, Miguel Ángel; Chiappi, Michele; Galindo, Inmaculada; Barrado-Gil, Lucía; Muñoz-Moreno, Raquel; Carrascosa, José L.

    2015-01-01

    ABSTRACT African swine fever virus (ASFV) is a major threat for porcine production that has been slowly spreading in Eastern Europe since its first appearance in the Caucasus in 2007. ASFV enters the cell by endocytosis and gains access to the cytosol to start replication from late endosomes and multivesicular bodies. Cholesterol associated with low-density lipoproteins entering the cell by endocytosis also follows a trafficking pathway similar to that of ASFV. Here we show that cholesterol plays an essential role in the establishment of infection as the virus traffics through the endocytic pathway. In contrast to the case for other DNA viruses, such as vaccinia virus or adenovirus 5, cholesterol efflux from endosomes is required for ASFV release/entry to the cytosol. Accumulation of cholesterol in endosomes impairs fusion, resulting in retention of virions inside endosomes. ASFV also remodels intracellular cholesterol by increasing its cellular uptake and redistributes free cholesterol to viral replication sites. Our analysis reveals that ASFV manipulates cholesterol dynamics to ensure an appropriate lipid flux to establish productive infection. IMPORTANCE Since its appearance in the Caucasus in 2007, African swine fever (ASF) has been spreading westwards to neighboring European countries, threatening porcine production. Due to the lack of an effective vaccine, ASF control relies on early diagnosis and widespread culling of infected animals. We investigated early stages of ASFV infection to identify potential cellular targets for therapeutic intervention against ASF. The virus enters the cell by endocytosis, and soon thereafter, viral decapsidation occurs in the acid pH of late endosomes. We found that ASFV infection requires and reorganizes the cellular lipid cholesterol. ASFV requires cholesterol to exit the endosome to gain access to the cytoplasm to establish productive replication. Our results indicate that there is a differential requirement for cholesterol

  19. Polarizable multipolar electrostatics for cholesterol

    NASA Astrophysics Data System (ADS)

    Fletcher, Timothy L.; Popelier, Paul L. A.

    2016-08-01

    FFLUX is a novel force field under development for biomolecular modelling, and is based on topological atoms and the machine learning method kriging. Successful kriging models have been obtained for realistic electrostatics of amino acids, small peptides, and some carbohydrates but here, for the first time, we construct kriging models for a sizeable ligand of great importance, which is cholesterol. Cholesterol's mean total (internal) electrostatic energy prediction error amounts to 3.9 kJ mol-1, which pleasingly falls below the threshold of 1 kcal mol-1 often cited for accurate biomolecular modelling. We present a detailed analysis of the error distributions.

  20. Effect of ezetimibe on plasma cholesterol levels, cholesterol absorption, and secretion of biliary cholesterol in laboratory opossums with high and low responses to dietary cholesterol.

    PubMed

    Chan, Jeannie; Kushwaha, Rampratap S; Vandeberg, Jane F; Vandeberg, John L

    2008-12-01

    Partially inbred lines of laboratory opossums differ in plasma low-density lipoprotein cholesterol concentration and cholesterol absorption on a high-cholesterol diet. The aim of the present studies was to determine whether ezetimibe inhibits cholesterol absorption and eliminates the differences in plasma cholesterol and hepatic cholesterol metabolism between high and low responders on a high-cholesterol diet. Initially, we determined that the optimum dose of ezetimibe was 5 mg/(kg d) and treated 6 high- and 6 low-responding opossums with this dose (with equal numbers of controls) for 3 weeks while the opossums consumed a high-cholesterol and low-fat diet. Plasma and low-density lipoprotein cholesterol concentrations decreased significantly (P < .05) in treated but not in untreated high-responding opossums. Plasma cholesterol concentrations increased slightly (P < .05) in untreated low responders but not in treated low responders. The percentage of cholesterol absorption was significantly higher in untreated high responders than in other groups. Livers from high responders with or without treatment were significantly (P < .01) heavier than livers from low responders with or without treatment. Hepatic cholesterol concentrations in untreated high responders were significantly (P < .05) higher than those in low responders with or without treatment (P < .001). The gall bladder bile cholesterol concentrations in untreated high responders were significantly (P < .05) lower than those in other groups. A decrease in biliary cholesterol in low responders treated with ezetimibe was associated with a decrease in hepatic expression of ABCG5 and ABCG8. These studies suggest that ezetimibe decreases plasma cholesterol levels in high responders mainly by decreasing cholesterol absorption and increasing biliary cholesterol concentrations. Because ezetimibe's target is NPC1L1 and NPC1L1 is expressed in the intestine of opossums, its effect on cholesterol absorption may be mediated

  1. Domestic minor sex trafficking: what the PNP needs to know.

    PubMed

    Hornor, Gail

    2015-01-01

    Human trafficking is a major global public health problem and represents a substantial human rights violation. Human trafficking has been receiving attention in both the lay media and professional literature. Human trafficking can include commercial sex, forced labor, child soldiers, and stealing of human organs. One form of human trafficking represents a significant American pediatric health problem: domestic minor sex trafficking (DMST). DMST is the commercial sexual abuse of children by selling, buying, or trading their sexual service. This continuing education article will define DMST and discuss it in terms of prevalence, risk factors, and practice implications for the pediatric nurse practitioner. PMID:25497135

  2. Domestic minor sex trafficking: what the PNP needs to know.

    PubMed

    Hornor, Gail

    2015-01-01

    Human trafficking is a major global public health problem and represents a substantial human rights violation. Human trafficking has been receiving attention in both the lay media and professional literature. Human trafficking can include commercial sex, forced labor, child soldiers, and stealing of human organs. One form of human trafficking represents a significant American pediatric health problem: domestic minor sex trafficking (DMST). DMST is the commercial sexual abuse of children by selling, buying, or trading their sexual service. This continuing education article will define DMST and discuss it in terms of prevalence, risk factors, and practice implications for the pediatric nurse practitioner.

  3. Cortical development of AMPA receptor trafficking proteins

    PubMed Central

    Murphy, Kathryn M.; Tcharnaia, Lilia; Beshara, Simon P.; Jones, David G.

    2012-01-01

    AMPA-receptor trafficking plays a central role in excitatory plasticity, especially during development. Changes in the number of AMPA receptors and time spent at the synaptic surface are important factors of plasticity that directly affect long-term potentiation (LTP), long-term depression (LTD), synaptic scaling, and the excitatory-inhibitory (E/I) balance in the developing cortex. Experience-dependent changes in synaptic strength in visual cortex (V1) use a molecularly distinct AMPA trafficking pathway that includes the GluA2 subunit. We studied developmental changes in AMPA receptor trafficking proteins by quantifying expression of GluA2, pGluA2 (GluA2serine880), GRIP1, and PICK1 in rat visual and frontal cortex. We used Western Blot analysis of synaptoneurosome preparations of rat visual and frontal cortex from animals ranging in age from P0 to P105. GluA2 and pGluA2 followed different developmental trajectories in visual and frontal cortex, with a brief period of over expression in frontal cortex. The over expression of GluA2 and pGluA2 in immature frontal cortex raises the possibility that there may be a period of GluA2-dependent vulnerability in frontal cortex that is not found in V1. In contrast, GRIP1 and PICK1 had the same developmental trajectories and were expressed very early in development of both cortical areas. This suggests that the AMPA-interacting proteins are available to begin trafficking receptors as soon as GluA2-containing receptors are expressed. Finally, we used all four proteins to analyze the surface-to-internalization balance and found that this balance was roughly equal across both cortical regions, and throughout development. Our finding of an exquisite surface-to-internalization balance highlights that these AMPA receptor trafficking proteins function as a tightly controlled system in the developing cortex. PMID:22623912

  4. Membrane Cholesterol Modulates Superwarfarin Toxicity.

    PubMed

    Marangoni, M Natalia; Martynowycz, Michael W; Kuzmenko, Ivan; Braun, David; Polak, Paul E; Weinberg, Guy; Rubinstein, Israel; Gidalevitz, David; Feinstein, Douglas L

    2016-04-26

    Superwarfarins are modified analogs of warfarin with additional lipophilic aromatic rings, up to 100-fold greater potency, and longer biological half-lives. We hypothesized that increased hydrophobicity allowed interactions with amphiphilic membranes and modulation of biological responses. We find that superwarfarins brodifacoum and difenacoum increase lactate production and cell death in neuroblastoma cells. In contrast, neither causes changes in glioma cells that have higher cholesterol content. After choleterol depletion, lactate production was increased and cell viability was reduced. Drug-membrane interactions were examined by surface X-ray scattering using Langmuir monolayers of dipalmitoylphosphatidylcholine and/or cholesterol. Specular X-ray reflectivity data revealed that superwarfarins, but not warfarin, intercalate between dipalmitoylphosphatidylcholine molecules, whereas grazing incidence X-ray diffraction demonstrated changes in lateral crystalline order of the film. Neither agent showed significant interactions with monolayers containing >20% cholesterol. These findings demonstrate an affinity of superwarfarins to biomembranes and suggest that cellular responses to these agents are regulated by cholesterol content. PMID:27119638

  5. Cholesterol autoxidation in phospholipid membrane bilayers

    SciTech Connect

    Sevanian, A.; McLeod, L.L.

    1987-09-01

    Lipid peroxidation in unilamellar liposomes of known cholesterol-phospholipid composition was monitored under conditions of autoxidation or as induced by a superoxide radical generating system, gamma-irradiation or cumene hydroperoxide. Formation of cholesterol oxidation products was indexed to the level of lipid peroxidation. The major cholesterol oxidation products identified were 7-keto-cholesterol, isomeric cholesterol 5,6-epoxides, isomeric 7-hydroperoxides and isomeric 3,7-cholestane diols. Other commonly encountered products included 3,5-cholestadiene-7-one and cholestane-3 beta, 5 alpha, 6 beta-triol. Superoxide-dependent peroxidation required iron and produced a gradual increase in 7-keto-cholesterol and cholesterol epoxides. Cholesterol oxidation was greatest in liposomes containing high proportions of unsaturated phospholipid to cholesterol (4:1 molar ratio), intermediate with low phospholipid to cholesterol ratios (2:1) and least in liposomes prepared with dipalmitoylphosphatidylcholine and cholesterol. This relationship held regardless of the oxidizing conditions used. Cumene hydroperoxide-dependent lipid peroxidation and/or more prolonged oxidations with other oxidizing systems yielded a variety of products where cholesterol-5 beta,6 beta-epoxide, 7-ketocholesterol and the 7-hydroperoxides were most consistently elevated. Oxyradical initiation of lipid peroxidation produced a pattern of cholesterol oxidation products distinguishable from the pattern derived by cumene hydroperoxide-dependent peroxidation.

  6. Trafficking and contract migrant workers in the Middle East.

    PubMed

    Jureidini, Ray

    2010-01-01

    The paper addresses a number of issues regarding the extent to which trafficking may be applied to migrant domestic workers who enter under the kafala system of sponsorship in the Middle East. Migrant domestic workers are the most numerous of those mentioned in reports on trafficking for labour exploitation in the region. The discussion seeks to determine whether "trafficking" can be ex post facto, rather than ex ante? In other words, can the label of trafficking be attributed only after the worker has arrived in the receiving country and is victimized according to the principles of trafficking protocols? In addition, must there be a proven intent to traffic by agents, or can employers who harm and/or exploit them be considered as traffickers alone? Should the harm done to workers on arrival at their place of work be classified (and assisted) as victims of trafficking, or as exploited workers?

  7. Parallel Information Processing.

    ERIC Educational Resources Information Center

    Rasmussen, Edie M.

    1992-01-01

    Examines parallel computer architecture and the use of parallel processors for text. Topics discussed include parallel algorithms; performance evaluation; parallel information processing; parallel access methods for text; parallel and distributed information retrieval systems; parallel hardware for text; and network models for information…

  8. Topographic heterogeneity in cholesterol biosynthesis.

    PubMed

    Lange, Y; Muraski, M F

    1988-07-01

    We have examined the membrane topography of cholesterol biosynthesis in cultured human fibroblasts. We fed the cells with radioacetate and then interrupted the biosynthetic pathway so as to trap labeled intermediates in their subcellular locations. We analyzed homogenates of human fibroblasts labeled biosynthetically from radioacetate by centrifugation to equilibrium on sucrose gradients. The following two methods were used to interrupt cholesterol biosynthesis: incubation at 10 degrees C and treatment with 4,4,10 beta-trimethyl-trans-decal-3 beta-ol, a specific inhibitor of oxidosqualene cyclase. Incubation at 10 degrees C caused the accumulation of radiolanosterol at the expense of cholesterol. The lanosterol appeared predominantly at an unusually buoyant density (20% (w/w) sucrose; d = 1.08 g/cm3) as well as at the density normally labeled at 37 degrees C (30% sucrose; d = 1.13 g/cm3). 4,4,10 beta-Trimethyl-trans-decal-3 beta-ol treatment caused the accumulation of labeled squalene and squalene 2,3-oxide. Reversal of the block permitted the label to progress rapidly as a wave into lanosterol and ultimately into cholesterol. The profiles of the three precursors did not coincide, suggesting that they were mostly in different membranes. Squalene was uniquely confined to a density of 1.18 g/cm3 (40% sucrose) while squalene 2,3-oxide appeared in peaks of density 1.08 g/cm3 and 1.13 g/cm3 (20% and 30% sucrose). Lanosterol was in a peak of density 1.13 g/cm3. Pulse-chase experiments showed that lanosterol synthesized in the membranes at 20% sucrose moved rapidly to the membranes at 30% sucrose where it was converted to cholesterol. The density gradient profiles of the following organelle markers also were monitored: plasma membrane, cholesterol mass; Golgi apparatus, galactosyltransferase; endoplasmic reticulum, RNA, 3-hydroxy-3-methylglutaryl-coenzyme A reductase and cytochrome c reductase; peroxisomes, catalase. None of these markers appeared at the buoyant density

  9. Inherited Cholesterol Disorder Significantly Boosts Heart Risks

    MedlinePlus

    ... genetic disorder that causes high levels of "bad" LDL cholesterol have an increased risk for heart disease and ... in previous studies. Compared to people with average LDL cholesterol levels (less than 130 mg/dL), those with ...

  10. High Cholesterol: Medicines to Help You

    MedlinePlus

    ... Consumer Information by Audience For Women High Cholesterol--Medicines To Help You Share Tweet Linkedin Pin it ... Test to check your cholesterol (LDL-C) Combination Medicines Brand Name Generic Name Advicor Niacin and Lovastatin ...

  11. Do You Know Your Cholesterol Levels?

    MedlinePlus

    ... Health Information Center Do You Know Your Cholesterol Levels? Print-friendly Version (PDF, 6.1 MB) Spanish ... Syndrome? My Family Plan To Lower Blood Cholesterol Levels My Heart Health Card Play It Smart, Take ...

  12. Active membrane cholesterol as a physiological effector.

    PubMed

    Lange, Yvonne; Steck, Theodore L

    2016-09-01

    Sterols associate preferentially with plasma membrane sphingolipids and saturated phospholipids to form stoichiometric complexes. Cholesterol in molar excess of the capacity of these polar bilayer lipids has a high accessibility and fugacity; we call this fraction active cholesterol. This review first considers how active cholesterol serves as an upstream regulator of cellular sterol homeostasis. The mechanism appears to utilize the redistribution of active cholesterol down its diffusional gradient to the endoplasmic reticulum and mitochondria, where it binds multiple effectors and directs their feedback activity. We have also reviewed a broad literature in search of a role for active cholesterol (as opposed to bulk cholesterol or lipid domains such as rafts) in the activity of diverse membrane proteins. Several systems provide such evidence, implicating, in particular, caveolin-1, various kinds of ABC-type cholesterol transporters, solute transporters, receptors and ion channels. We suggest that this larger role for active cholesterol warrants close attention and can be tested easily.

  13. Physical health symptoms reported by trafficked women receiving post-trafficking support in Moldova: prevalence, severity and associated factors

    PubMed Central

    2012-01-01

    Background Many trafficked people suffer high levels of physical, sexual and psychological abuse. Yet, there has been limited research on the physical health problems associated with human trafficking or how the health needs of women in post-trafficking support settings vary according to socio-demographic or trafficking characteristics. Methods We analysed the prevalence and severity of 15 health symptoms reported by 120 trafficked women who had returned to Moldova between December 2007 and December 2008 and were registered with the International Organisation for Migration Assistance and Protection Programme. Women had returned to Moldova an average of 5.9 months prior to interview (range 2-12 months). Results Headaches (61.7%), stomach pain (60.9%), memory problems (44.2%), back pain (42.5%), loss of appetite (35%), and tooth pain (35%) were amongst the most commonly reported symptoms amongst both women trafficked for sexual exploitation and women trafficked for labour exploitation. The prevalence of headache and memory problems was strongly associated with duration of exploitation. Conclusions Trafficked women who register for post-trafficking support services after returning to their country of origin are likely to have long-term physical and dental health needs and should be provided with access to comprehensive medical services. Health problems among women who register for post-trafficking support services after returning to their country of origin are not limited to women trafficked for sexual exploitation but are also experienced by victims of labour exploitation. PMID:22834807

  14. Quercetin regulates hepatic cholesterol metabolism by promoting cholesterol-to-bile acid conversion and cholesterol efflux in rats.

    PubMed

    Zhang, Min; Xie, Zongkai; Gao, Weina; Pu, Lingling; Wei, Jingyu; Guo, Changjiang

    2016-03-01

    Quercetin, a common member of the flavonoid family, is widely present in plant kingdom. Despite that quercetin is implicated in regulating cholesterol metabolism, the molecular mechanism is poorly understood. We hypothesized that quercetin regulates cholesterol homeostasis through regulating the key enzymes involved in hepatic cholesterol metabolism. To test this hypothesis, we compared the profile of key enzymes and transcription factors involved in the hepatic cholesterol metabolism in rats with or without quercetin supplementation. Twenty male Wistar rats were randomly divided into control and quercetin-supplemented groups. Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total bile acids in feces and bile were measured. Hepatic enzymatic activities were determined by activity assay kit and high-performance liquid chromatography-based analyses. The messenger RNA (mRNA) and protein expressions were determined by reverse transcriptase polymerase chain reaction and Western blot analyses, respectively. The results showed that the activity of hepatic cholesterol 7α-hydroxylase, a critical enzyme in the conversion of cholesterol to bile acids, was significantly elevated by quercetin. The expression of cholesterol 7α-hydroxylase, as well as liver X receptor α, an important transcription factor, was also increased at both mRNA and protein levels by quercetin. However, quercetin exposure had no impact on the activity of hepatic HMG-CoA reductase, a rate-limiting enzyme in the biosynthesis of cholesterol. We also found that quercetin treatment significantly increased ATP binding cassette transporter G1 mRNA and protein expression in the liver, suggesting that quercetin may increase hepatic cholesterol efflux. Collectively, the results presented here indicate that quercetin regulates hepatic cholesterol metabolism mainly through the pathways that promote cholesterol-to-bile acid conversion and

  15. Isolation of Cholesterol from an Egg Yolk

    ERIC Educational Resources Information Center

    Taber, Douglass F.; Li, Rui; Anson, Cory M.

    2011-01-01

    A simple procedure for the isolation of the cholesterol, by hydrolysis and extraction followed by column chromatography, is described. The cholesterol can be further purified by complexation with oxalic acid. It can also be oxidized and conjugated to cholestenone. The source of the cholesterol is one egg yolk, which contains about 200 mg of…

  16. Cholesterol Screening: A Practical Guide to Implementation.

    ERIC Educational Resources Information Center

    Kingery, Paul M.

    1995-01-01

    Dry-chemistry cholesterol analysis has made screening feasible in a variety of settings. The article provides practical tips for the implementation of mass cholesterol screening using a portable dry-chemistry analyzer and discusses issues involved in conducting effective cholesterol screening programs from start to finish. (SM)

  17. A sensitive assay for ABCA1-mediated cholesterol efflux using BODIPY -cholesterol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies have shown a negative association between cellular cholesterol efflux and coronary artery disease (CAD). Standard protocol for quantifying cholesterol efflux involves labeling cells with [(3)H]cholesterol and measuring release of the labeled sterol. Using [(3)H]cholesterol is not ideal for...

  18. Percentage of Adults with High Cholesterol Whose LDL Cholesterol Levels Are Adequately Controlled

    MedlinePlus

    ... of Adults with High Cholesterol Whose LDL Cholesterol Levels are Adequately Controlled High cholesterol can double a ... with High Cholesterol that is Controlled by Education Level 8k4c-k22f Download these data » Click on legends ...

  19. Overexpression of lecithin:cholesterol acyltransferase in transgenic rabbits prevents diet-induced atherosclerosis.

    PubMed Central

    Hoeg, J M; Santamarina-Fojo, S; Bérard, A M; Cornhill, J F; Herderick, E E; Feldman, S H; Haudenschild, C C; Vaisman, B L; Hoyt, R F; Demosky, S J; Kauffman, R D; Hazel, C M; Marcovina, S M; Brewer, H B

    1996-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is a key plasma enzyme in cholesterol and high density lipoprotein (HDL) metabolism. Transgenic rabbits overexpressing human LCAT had 15-fold greater plasma LCAT activity that nontransgenic control rabbits. This degree of overexpression was associated with a 6.7-fold increase in the plasma HDL cholesterol concentration in LCAT transgenic rabbits. On a 0.3% cholesterol diet, the HDL cholesterol concentrations increased from 24 +/- 1 to 39 +/- 3 mg/dl in nontransgenic control rabbits (n = 10; P < 0.05) and increased from 161 +/- 5 to 200 +/- 21 mg/dl (P < 0.001) in the LCAT transgenic rabbits (n = 9). Although the baseline non-HDL concentrations of control (4 +/- 3 mg/dl) and transgenic rabbits (18 +/- 4 mg/dl) were similar, the cholesterol-rich diet raised the non-HDL cholesterol concentrations, reflecting the atherogenic very low density, intermediate density, and low density lipoprotein particles observed by gel filtration chromatography. The non-HDL cholesterol rose to 509 +/- 57 mg/dl in controls compared with only 196 +/- 14 mg/dl in the LCAT transgenic rabbits (P < 0.005). The differences in the plasma lipoprotein response to a cholesterol-rich diet observed in the transgenic rabbits paralleled the susceptibility to developing aortic atherosclerosis. Compared with nontransgenic controls, LCAT transgenic rabbits were protected from diet-induced atherosclerosis with significant reductions determined by both quantitative planimetry (-86%; P < 0.003) and quantitative immunohistochemistry (-93%; P < 0.009). Our results establish the importance of LCAT in the metabolism of both HDL and apolipoprotein B-containing lipoprotein particles with cholesterol feeding and the response to diet-induced atherosclerosis. In addition, these findings identify LCAT as a new target for therapy to prevent atherosclerosis. Images Fig. 2 Fig. 3 Fig. 4 PMID:8876155

  20. Cholesterol under oxidative stress-How lipid membranes sense oxidation as cholesterol is being replaced by oxysterols.

    PubMed

    Kulig, Waldemar; Olżyńska, Agnieszka; Jurkiewicz, Piotr; Kantola, Anu M; Komulainen, Sanna; Manna, Moutusi; Pourmousa, Mohsen; Vazdar, Mario; Cwiklik, Lukasz; Rog, Tomasz; Khelashvili, George; Harries, Daniel; Telkki, Ville-Veikko; Hof, Martin; Vattulainen, Ilpo; Jungwirth, Pavel

    2015-07-01

    The behavior of oxysterols in phospholipid membranes and their effects on membrane properties were investigated by means of dynamic light scattering, fluorescence spectroscopy, NMR, and extensive atomistic simulations. Two families of oxysterols were scrutinized-tail-oxidized sterols, which are mostly produced by enzymatic processes, and ring-oxidized sterols, formed mostly via reactions with free radicals. The former family of sterols was found to behave similar to cholesterol in terms of molecular orientation, roughly parallel to the bilayer normal, leading to increasing membrane stiffness and suppression of its membrane permeability. In contrast, ring-oxidized sterols behave quantitatively differently from cholesterol. They acquire tilted orientations and therefore disrupt the bilayer structure with potential implications for signaling and other biochemical processes in the membranes.

  1. Sex Trafficking: Policies, Programs, and Services.

    PubMed

    Orme, Julie; Ross-Sheriff, Fariyal

    2015-10-01

    Sex trafficking (ST), a contemporary form of female slavery, is a human rights issue of critical concern to social work. The global response to ST has been substantial, and 166 countries have adopted anti-ST legislation. Despite considerable efforts to combat ST, the magnitude is increasing. To date, the majority of anti-ST efforts have focused on criminalization policies that target traffickers or purchasers of sexual services, who are predominantly male; prevention programming and services for predominantly female victims have received less support. Therapeutic services to assist pornography addicts and purchasers of sexual services are also necessary. In this article, authors examine current anti-ST policies, programs, and services, both domestically and globally, and present an innovative paradigm that addresses social inequities and emphasizes prevention programming. They conclude with a discussion of the paradigm's implications for social work policies, practices, and services. PMID:26489349

  2. Technosocial Predictive Analytics for Illicit Nuclear Trafficking

    SciTech Connect

    Sanfilippo, Antonio P.; Butner, R. Scott; Cowell, Andrew J.; Dalton, Angela C.; Haack, Jereme N.; Kreyling, Sean J.; Riensche, Roderick M.; White, Amanda M.; Whitney, Paul D.

    2011-03-29

    Illicit nuclear trafficking networks are a national security threat. These networks can directly lead to nuclear proliferation, as state or non-state actors attempt to identify and acquire nuclear weapons-related expertise, technologies, components, and materials. The ability to characterize and anticipate the key nodes, transit routes, and exchange mechanisms associated with these networks is essential to influence, disrupt, interdict or destroy the function of the networks and their processes. The complexities inherent to the characterization and anticipation of illicit nuclear trafficking networks requires that a variety of modeling and knowledge technologies be jointly harnessed to construct an effective analytical and decision making workflow in which specific case studies can be built in reasonable time and with realistic effort. In this paper, we explore a solution to this challenge that integrates evidentiary and dynamic modeling with knowledge management and analytical gaming, and demonstrate its application to a geopolitical region at risk.

  3. Maritime drug trafficking: an underrated problem.

    PubMed

    Aune, B R

    1990-01-01

    Seizure data indicate that a substantial proportion of the total quantity of drugs seized is confiscated from maritime modes of conveyance or has been transported by sea. The trafficking of narcotic drugs by sea has virtually become an industry comprised of many individual enterprises of varying size and organization. The maritime medium is one of the main ways by which drugs may enter some countries. In response to the problem, various sophisticated anti-trafficking offensives and strategies have been established or contemplated in certain geographical areas. The shipment of drugs to the primary consuming countries has not been curbed, however, and there is every indication that the overall movement of drugs is still unimpeded.

  4. Regulatory T-cell compartmentalization and trafficking

    PubMed Central

    Wei, Shuang; Kryczek, Ilona; Zou, Weiping

    2006-01-01

    CD4+CD25+FOXP3+ regulatory T cells (CD4+ Treg cells) are thought to differentiate in the thymus and immigrate from the thymus to the periphery. Treg cells can regulate both acquired and innate immunity through multiple modes of suppression. The cross-talk between Treg cells and targeted cells, such as antigen-presenting cells (APCs) and T cells, is crucial for ensuring suppression by Treg cells in the appropriate microenvironment. Emerging evidence suggests that Treg compartmentalization and trafficking may be tissue or/and organ specific and that distinct chemokine receptor and integrin expression may contribute to selective retention and trafficking of Treg cells at sites where regulation is required. In this review, the cellular and molecular signals that control specialized migration and retention of Treg cells are discussed. PMID:16537800

  5. Endocytic membrane trafficking and neurodegenerative disease.

    PubMed

    Schreij, Andrea M A; Fon, Edward A; McPherson, Peter S

    2016-04-01

    Neurodegenerative diseases are amongst the most devastating of human disorders. New technologies have led to a rapid increase in the identification of disease-related genes with an enhanced appreciation of the key roles played by genetics in the etiology of these disorders. Importantly, pinpointing the normal function of disease gene proteins leads to new understanding of the cellular machineries and pathways that are altered in the disease process. One such emerging pathway is membrane trafficking in the endosomal system. This key cellular process controls the localization and levels of a myriad of proteins and is thus critical for normal cell function. In this review we will focus on three neurodegenerative diseases; Parkinson disease, amyotrophic lateral sclerosis, and hereditary spastic paraplegias, for which a large number of newly discovered disease genes encode proteins that function in endosomal membrane trafficking. We will describe how alterations in these proteins affect endosomal function and speculate on the contributions of these disruptions to disease pathophysiology. PMID:26721251

  6. Sex Trafficking: Policies, Programs, and Services.

    PubMed

    Orme, Julie; Ross-Sheriff, Fariyal

    2015-10-01

    Sex trafficking (ST), a contemporary form of female slavery, is a human rights issue of critical concern to social work. The global response to ST has been substantial, and 166 countries have adopted anti-ST legislation. Despite considerable efforts to combat ST, the magnitude is increasing. To date, the majority of anti-ST efforts have focused on criminalization policies that target traffickers or purchasers of sexual services, who are predominantly male; prevention programming and services for predominantly female victims have received less support. Therapeutic services to assist pornography addicts and purchasers of sexual services are also necessary. In this article, authors examine current anti-ST policies, programs, and services, both domestically and globally, and present an innovative paradigm that addresses social inequities and emphasizes prevention programming. They conclude with a discussion of the paradigm's implications for social work policies, practices, and services.

  7. D38-cholesterol as a Raman active probe for imaging intracellular cholesterol storage

    NASA Astrophysics Data System (ADS)

    Alfonso-García, Alba; Pfisterer, Simon G.; Riezman, Howard; Ikonen, Elina; Potma, Eric O.

    2016-06-01

    We generated a highly deuterated cholesterol analog (D38-cholesterol) and demonstrated its use for selective vibrational imaging of cholesterol storage in mammalian cells. D38-cholesterol produces detectable signals in stimulated Raman scattering (SRS) imaging, is rapidly taken up by cells, and is efficiently metabolized by acyl-CoA cholesterol acyltransferase to form cholesteryl esters. Using hyperspectral SRS imaging of D38-cholesterol, we visualized cholesterol storage in lipid droplets. We found that some lipid droplets accumulated preferentially unesterified D38-cholesterol, whereas others stored D38-cholesteryl esters. In steroidogenic cells, D38-cholesteryl esters and triacylglycerols were partitioned into distinct sets of lipid droplets. Thus, hyperspectral SRS imaging of D38-cholesterol demonstrates a heterogeneous incorporation of neutral lipid species, i.e., free cholesterol, cholesteryl esters, and triacylglycerols, between individual lipid droplets in a cell.

  8. D38-cholesterol as a Raman active probe for imaging intracellular cholesterol storage.

    PubMed

    Alfonso-García, Alba; Pfisterer, Simon G; Riezman, Howard; Ikonen, Elina; Potma, Eric O

    2016-06-01

    We generated a highly deuterated cholesterol analog (D38-cholesterol) and demonstrated its use for selective vibrational imaging of cholesterol storage in mammalian cells. D38-cholesterol produces detectable signals in stimulated Raman scattering (SRS) imaging, is rapidly taken up by cells, and is efficiently metabolized by acyl-CoA cholesterol acyltransferase to form cholesteryl esters. Using hyperspectral SRS imaging of D38-cholesterol, we visualized cholesterol storage in lipid droplets. We found that some lipid droplets accumulated preferentially unesterified D38-cholesterol, whereas others stored D38-cholesteryl esters. In steroidogenic cells, D38-cholesteryl esters and triacylglycerols were partitioned into distinct sets of lipid droplets. Thus, hyperspectral SRS imaging of D38-cholesterol demonstrates a heterogeneous incorporation of neutral lipid species, i.e., free cholesterol, cholesteryl esters, and triacylglycerols, between individual lipid droplets in a cell.

  9. Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

    NASA Astrophysics Data System (ADS)

    Mandal, Pritam; Noutsi, Pakiza; Chaieb, Sahraoui

    2016-06-01

    Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.

  10. Relationship between plasma cholesterol levels and cholesterol esterification in isolated human mononuclear cells

    SciTech Connect

    Dallongeville, J.; Davignon, J.; Lussier-Cacan, S. )

    1990-01-01

    The authors studied the relationship between plasma lipoprotein concentrations and cholesterol esterification in freshly isolated human mononuclear cells from 27 normolipidemic and 32 hyperlipidemic individuals. Cells were either incubated for 5 hours with radiolabeled oleate immediately after isolation or were preincubated for 18 hours in the presence of exogenous cholesterol, and then incubated with ({sup 14}C)sodium-oleate-albumin complex. In the absence of exogenous cholesterol, control and hypercholesterolemic subjects had similarly low values of intracellular cholesterol esterification. In the presence of exogenous cholesterol, both hypertriglyceridemic and hypercholesterolemic subjects had higher cholesterol esterification than controls. There was a significant correlation between the rate of cholesterol esterification and plasma total cholesterol. These results suggest that plasma cholesterol levels may regulate mononuclear cell intra-cellular cholesterol esterification in humans.

  11. Fish protein hydrolysates affect cholesterol metabolism in rats fed non-cholesterol and high-cholesterol diets.

    PubMed

    Hosomi, Ryota; Fukunaga, Kenji; Arai, Hirofumi; Kanda, Seiji; Nishiyama, Toshimasa; Yoshida, Munehiro

    2012-03-01

    Fish consumption is well known to provide health benefits in both experimental animals and human subjects. Numerous studies have demonstrated the beneficial effects of various protein hydrolysates on lipid metabolism. In this context, this study examined the effect of fish protein hydrolysates (FPH) on cholesterol metabolism compared with the effect of casein. FPHs were prepared from Alaska pollock meat using papain as a protease. Male Wistar rats were divided into the following four dietary groups of seven rats each: either casein (20%) or FPH (10%) + casein (10%), with or without 0.5% cholesterol and 0.1% sodium cholate. Serum and liver lipid levels, fecal cholesterol and bile acid excretions, and the hepatic expression of genes encoding proteins involved in cholesterol homeostasis were examined. In rats fed the FPH diets compared with casein diets with or without cholesterol and sodium cholate, the indexes of cholesterol metabolism-namely, serum cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels-were significantly lower, whereas fecal cholesterol and bile acid excretions were higher. Rats fed the FPH diets compared with casein with cholesterol exhibited a lower liver cholesterol level via an increased liver cholesterol 7α-hydroxylase (CYP7A1) expression level. This study demonstrates that the intake of FPH has hypocholesterolemic effects through the enhancement of fecal cholesterol and bile acid excretions and CYP7A1 expression levels. Therefore, fish peptides prepared by papain digestion might provide health benefits by decreasing the cholesterol content in the blood, which would contribute to the prevention of circulatory system diseases such as arteriosclerosis. PMID:22181072

  12. Protein trafficking during plant innate immunity.

    PubMed

    Wang, Wen-Ming; Liu, Peng-Qiang; Xu, Yong-Ju; Xiao, Shunyuan

    2016-04-01

    Plants have evolved a sophisticated immune system to fight against pathogenic microbes. Upon detection of pathogen invasion by immune receptors, the immune system is turned on, resulting in production of antimicrobial molecules including pathogenesis-related (PR) proteins. Conceivably, an efficient immune response depends on the capacity of the plant cell's protein/membrane trafficking network to deploy the right defense-associated molecules in the right place at the right time. Recent research in this area shows that while the abundance of cell surface immune receptors is regulated by endocytosis, many intracellular immune receptors, when activated, are partitioned between the cytoplasm and the nucleus for induction of defense genes and activation of programmed cell death, respectively. Vesicle transport is an essential process for secretion of PR proteins to the apoplastic space and targeting of defense-related proteins to the plasma membrane or other endomembrane compartments. In this review, we discuss the various aspects of protein trafficking during plant immunity, with a focus on the immunity proteins on the move and the major components of the trafficking machineries engaged. PMID:26345282

  13. LCAT synthesized by primary astrocytes esterifies cholesterol on glia-derived lipoproteins

    PubMed Central

    Hirsch-Reinshagen, Veronica; Donkin, James; Stukas, Sophie; Chan, Jennifer; Wilkinson, Anna; Fan, Jianjia; Parks, John S.; Kuivenhoven, Jan Albert; Lütjohann, Dieter; Pritchard, Haydn; Wellington, Cheryl L.

    2009-01-01

    Lipid trafficking in the brain is essential for the maintenance and repair of neuronal membranes, especially after neurotoxic insults. However, brain lipid metabolism is not completely understood. In plasma, LCAT catalyses the esterification of free cholesterol on circulating lipoproteins, a key step in the maturation of HDL. Brain lipoproteins are apolipoprotein E (apoE)-containing, HDL-like particles secreted initially as lipid-poor discs by glial cells. LCAT is synthesized within the brain, suggesting that it may play a key role in the maturation of these lipoproteins. Here we demonstrate that astrocytes are the primary producers of brain LCAT. This LCAT esterifies free cholesterol on nascent apoE-containing lipopoproteins secreted from glia. ApoE is the major LCAT activator in glia-conditioned media (GCM), and both the cholesterol transporter ABCA1 and apoE are required to generate glial LCAT substrate particles. LCAT deficiency leads to the appearance of abnormal ∼8 nm particles in GCM, and exogenous LCAT restores the lipoprotein particle distribution to the wild-type (WT) pattern. In vivo, complete LCAT deficiency results in a dramatic increase in apoE-HDL and reduced apolipoprotein A-I (apoA-I)-HDL in murine cerebrospinal fluid (CSF). These data show that brain LCAT esterifies cholesterol on glial-derived apoE-lipoproteins, and influences CSF apoE and apoA-I levels. PMID:19065001

  14. Host Cell P-glycoprotein Is Essential for Cholesterol Uptake and Replication of Toxoplasma gondii*

    PubMed Central

    Bottova, Iveta; Hehl, Adrian B.; Štefanić, Saša; Fabriàs, Gemma; Casas, Josefina; Schraner, Elisabeth; Pieters, Jean; Sonda, Sabrina

    2009-01-01

    P-glycoprotein (P-gp) is a membrane-bound efflux pump that actively exports a wide range of compounds from the cell and is associated with the phenomenon of multidrug resistance. However, the role of P-gp in normal physiological processes remains elusive. Using P-gp-deficient fibroblasts, we showed that P-gp was critical for the replication of the intracellular parasite Toxoplasma gondii but was not involved in invasion of host cells by the parasite. Importantly, we found that the protein participated in the transport of host-derived cholesterol to the intracellular parasite. T. gondii replication in P-gp-deficient host cells not only resulted in reduced cholesterol content in the parasite but also altered its sphingolipid metabolism. In addition, we found that different levels of P-gp expression modified the cholesterol metabolism in uninfected fibroblasts. Collectively our findings reveal a key and previously undocumented role of P-gp in host-parasite interaction and suggest a physiological role for P-gp in cholesterol trafficking in mammalian cells. PMID:19389707

  15. Host cell P-glycoprotein is essential for cholesterol uptake and replication of Toxoplasma gondii.

    PubMed

    Bottova, Iveta; Hehl, Adrian B; Stefanić, Sasa; Fabriàs, Gemma; Casas, Josefina; Schraner, Elisabeth; Pieters, Jean; Sonda, Sabrina

    2009-06-26

    P-glycoprotein (P-gp) is a membrane-bound efflux pump that actively exports a wide range of compounds from the cell and is associated with the phenomenon of multidrug resistance. However, the role of P-gp in normal physiological processes remains elusive. Using P-gp-deficient fibroblasts, we showed that P-gp was critical for the replication of the intracellular parasite Toxoplasma gondii but was not involved in invasion of host cells by the parasite. Importantly, we found that the protein participated in the transport of host-derived cholesterol to the intracellular parasite. T. gondii replication in P-gp-deficient host cells not only resulted in reduced cholesterol content in the parasite but also altered its sphingolipid metabolism. In addition, we found that different levels of P-gp expression modified the cholesterol metabolism in uninfected fibroblasts. Collectively our findings reveal a key and previously undocumented role of P-gp in host-parasite interaction and suggest a physiological role for P-gp in cholesterol trafficking in mammalian cells. PMID:19389707

  16. Metals and cholesterol: two sides of the same coin in Alzheimer’s disease pathology

    PubMed Central

    Wong, Bruce X.; Hung, Ya Hui; Bush, Ashley I.; Duce, James A.

    2014-01-01

    Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease. It begins years prior to the onset of clinical symptoms, such as memory loss and cognitive decline. Pathological hallmarks of AD include the accumulation of β-amyloid in plaques and hyperphosphorylated tau in neurofibrillary tangles. Copper, iron, and zinc are abnormally accumulated and distributed in the aging brain. These metal ions can adversely contribute to the progression of AD. Dysregulation of cholesterol metabolism has also been implicated in the development of AD pathology. To date, large bodies of research have been carried out independently to elucidate the role of metals or cholesterol on AD pathology. Interestingly, metals and cholesterol affect parallel molecular and biochemical pathways involved in AD pathology. The possible links between metal dyshomeostasis and altered brain cholesterol metabolism in AD are reviewed. PMID:24860500

  17. Does cholesterol lowering prevent stroke?

    PubMed

    Henry, R Y; Kendall, M J

    1998-10-01

    The importance of lowering plasma cholesterol to reduce the incidence of coronary events is well established. However, in the prevention of stroke disease, control of hypertension has been the main aim of treatment and lipid lowering therapy has not hitherto been considered to be desirable or necessary. In this review, the evidence from large multicentre trials, imaging studies and meta-analyses is presented. It shows convincingly that HMG-CoA reductase inhibitors (Statins) reduce stroke risk. PMID:9875681

  18. Forensic medical examination of victims of trafficking in human beings.

    PubMed

    Alempijevic, Djordie; Jecmenica, Dragan; Pavlekic, Snezana; Savic, Slobodan; Aleksandric, Branimir

    2007-01-01

    Trafficking in human beigns (THB) is recognized as a global public health issue as well as a violation of human rights. Trafficking has been identified to be associated with several health risks including psychological trauma, injuries from violence, and substance misuse. Public and media reports suggest that the morbidity and mortality associated with trafficking are substantial. The need of medico-legal healthcare for THB victims is being neglected. Forensic medical examination, as specific intervention, is a highly desirable element of ermegency health care provided for victims of tracking. Acting in such a way, the investigation should establish the facts related to the allegatation of trafficking, thereby assisting in identifying those responsible, but also contributing to the procedures designed to obtain redress for the victims. Local anti-trafficking policies and interventions, however, have not acknowledged these needs. Therefore, the agenda of anti-trafficking policies needs to be redrawn to include forensic medical assessment of victims for legal purposes.

  19. Trends in production, trafficking, and consumption of methamphetamine and cocaine in Mexico.

    PubMed

    Brouwer, Kimberly C; Case, Patricia; Ramos, Rebeca; Magis-Rodríguez, Carlos; Bucardo, Jesus; Patterson, Thomas L; Strathdee, Steffanie A

    2006-01-01

    Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of United States cocaine originating in South America passes through the Central America-Mexico corridor. Mexico-based groups are now believed to control 70%-90% of methamphetamine production and distribution in the United States. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetamine abuse is now the primary reason for seeking drug abuse treatment in a number of cities, primarily in northwestern Mexico. Although cocaine and methamphetamine use have been linked with the sex trade and high-risk behaviors, such as shooting gallery attendance and unprotected sex in other settings, comparatively little is known about the risk behaviors associated with use of these drugs in Mexico, especially for methamphetamines. We review historical aspects and current trends in cocaine and methamphetamine production, trafficking, and consumption in Mexico, with special emphasis on the border cities of Ciudad Juarez and Tijuana. Additionally, we discuss the potential public health consequences of cocaine use and the recent increase in methamphetamine use, especially in regards to the spread of bloodborne and other infections, in an effort to inform appropriate public health interventions.

  20. Trends in production, trafficking, and consumption of methamphetamine and cocaine in Mexico.

    PubMed

    Brouwer, Kimberly C; Case, Patricia; Ramos, Rebeca; Magis-Rodríguez, Carlos; Bucardo, Jesus; Patterson, Thomas L; Strathdee, Steffanie A

    2006-01-01

    Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of United States cocaine originating in South America passes through the Central America-Mexico corridor. Mexico-based groups are now believed to control 70%-90% of methamphetamine production and distribution in the United States. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetamine abuse is now the primary reason for seeking drug abuse treatment in a number of cities, primarily in northwestern Mexico. Although cocaine and methamphetamine use have been linked with the sex trade and high-risk behaviors, such as shooting gallery attendance and unprotected sex in other settings, comparatively little is known about the risk behaviors associated with use of these drugs in Mexico, especially for methamphetamines. We review historical aspects and current trends in cocaine and methamphetamine production, trafficking, and consumption in Mexico, with special emphasis on the border cities of Ciudad Juarez and Tijuana. Additionally, we discuss the potential public health consequences of cocaine use and the recent increase in methamphetamine use, especially in regards to the spread of bloodborne and other infections, in an effort to inform appropriate public health interventions. PMID:16603456

  1. Trends in Production, Trafficking and Consumption of Methamphetamine and Cocaine in Mexico

    PubMed Central

    Brouwer, Kimberly C.; Case, Patricia; Ramos, Rebeca; Magis-Rodríguez, Carlos; Bucardo, Jesus; Patterson, Thomas L.; Strathdee, Steffanie A.

    2009-01-01

    Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of U.S. cocaine originating in South America passes through the Central America-Mexico corridor. Mexico-based groups are now believed to control 70%–90% of methamphetamine production and distribution in the U.S. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetamine abuse is now the primary reason for seeking drug user treatment in a number of cities, primarily in northwestern Mexico. While cocaine and methamphetamine use have been linked with the sex trade and high risk behaviors such as shooting gallery attendance and unprotected sex in other settings, comparatively little is known about the risk behaviors associated with use of these drugs in Mexico, especially for methamphetamines. We review historical aspects and current trends in cocaine and methamphetamine production, trafficking and consumption in Mexico, with special emphasis on the border cities of Ciudad Juarez and Tijuana. Additionally, we discuss the potential public health consequences of cocaine use and the recent increase in methamphetamine use, especially in regards to the spread of bloodborne and other infections, in an effort to inform appropriate public health interventions. PMID:16603456

  2. A role for mRNA trafficking and localized translation in peroxisome biogenesis and function?

    PubMed

    Haimovich, Gal; Cohen-Zontag, Osnat; Gerst, Jeffrey E

    2016-05-01

    Peroxisomes are distinct membrane-enclosed organelles involved in the β-oxidation of fatty acids and synthesis of ether phospholipids (e.g. plasmalogens), as well as cholesterol and its derivatives (e.g. bile acids). Peroxisomes comprise a distinct and highly segregated subset of cellular proteins, including those of the peroxisome membrane and the interior matrix, and while the mechanisms of protein import into peroxisomes have been extensively studied, they are not fully understood. Here we will examine the potential role of RNA trafficking and localized translation on protein import into peroxisomes and its role in peroxisome biogenesis and function. Given that RNAs encoding peroxisome biogenesis (PEX) and matrix proteins have been found in association with the endoplasmic reticulum and peroxisomes, it suggests that localized translation may play a significant role in the import pathways of these different peroxisomal constituents.

  3. A role for mRNA trafficking and localized translation in peroxisome biogenesis and function?

    PubMed

    Haimovich, Gal; Cohen-Zontag, Osnat; Gerst, Jeffrey E

    2016-05-01

    Peroxisomes are distinct membrane-enclosed organelles involved in the β-oxidation of fatty acids and synthesis of ether phospholipids (e.g. plasmalogens), as well as cholesterol and its derivatives (e.g. bile acids). Peroxisomes comprise a distinct and highly segregated subset of cellular proteins, including those of the peroxisome membrane and the interior matrix, and while the mechanisms of protein import into peroxisomes have been extensively studied, they are not fully understood. Here we will examine the potential role of RNA trafficking and localized translation on protein import into peroxisomes and its role in peroxisome biogenesis and function. Given that RNAs encoding peroxisome biogenesis (PEX) and matrix proteins have been found in association with the endoplasmic reticulum and peroxisomes, it suggests that localized translation may play a significant role in the import pathways of these different peroxisomal constituents. PMID:26367800

  4. Regulation of biliary cholesterol secretion in the rat. Role of hepatic cholesterol esterification.

    PubMed Central

    Nervi, F; Bronfman, M; Allalón, W; Depiereux, E; Del Pozo, R

    1984-01-01

    Although the significance of the enterohepatic circulation of bile salts in the solubilization and biliary excretion of cholesterol is well established, little is known about the intrahepatic determinants of biliary cholesterol output. Studies were undertaken to elucidate some of these determinants in the rat. Feeding 1% diosgenin for 1 wk increased biliary cholesterol output and saturation by 400%. Bile flow, biliary bile salt, phospholipid and protein outputs remained in the normal range. When ethynyl estradiol (EE) was injected into these animals, biliary cholesterol output decreased to almost normal levels under circumstances of minor changes in the rates of biliary bile salt and phospholipid outputs. Similarly, when chylomicron cholesterol was intravenously injected into diosgenin-fed animals, biliary cholesterol output significantly decreased as a function of the dose of chylomicron cholesterol administered. Relative rates of hepatic cholesterol synthesis and esterification were measured in isolated hepatocytes. Although hepatic cholesterogenesis increased 300% in diosgenin-fed animals, the contribution of newly synthesized cholesterol to total biliary cholesterol output was only 19 +/- 9%, compared with 12 +/- 6% in control and 15 +/- 5% in diosgenin-fed and EE-injected rats. The rate of oleate incorporation into hepatocytic cholesterol esters was 30% inhibited in diosgenin-fed rats. When EE was injected into these animals, the rate of cholesterol esterification increased to almost 300%. To investigate further the interrelationship between hepatic cholesterol esterification and biliary cholesterol output, we studied 21 diosgenin-fed rats. Six of them received in addition EE and 10 received chylomicron cholesterol. The relationships between biliary cholesterol output as a function of both microsomal acyl-CoA:cholesterol acyltransferase (ACAT) activity and hepatic cholesterol ester concentration were significantly correlated in a reciprocal manner. From these

  5. The ATP-binding Cassette Transporter-2 (ABCA2) Regulates Cholesterol Homeostasis and Low-density Lipoprotein Receptor Metabolism in N2a Neuroblastoma Cells

    PubMed Central

    Davis, Warren

    2011-01-01

    The ATP-binding cassette transporter-2 (ABCA2) has been identified as a possible regulator of lipid metabolism. ABCA2 is most highly expressed in the brain but its effects on cholesterol homeostasis in neuronal-type cells have not been characterized. It is important to study the role of ABCA2 in regulating cholesterol homeostasis in neuronal-type cells because ABCA2 has been identified as a possible genetic risk factor for Alzheimer’s disease. In this study, the effects of ABCA2 expression on cholesterol homeostasis were examined in mouse N2a neuroblastoma cells. ABCA2 reduced total, free- and esterified cholesterol levels as well as membrane cholesterol but did not perturb cholesterol distribution in organelle or lipid raft compartments. ABCA2 did not modulate de novo cholesterol biosynthesis from acetate. Cholesterol trafficking to the plasma membrane was not affected by ABCA2 but efflux to the physiological acceptor ApoE3 and mobilization of plasma membrane cholesterol to the endoplasmic reticulum for esterification were reduced by ABCA2. ABCA2 reduced esterification of serum and low-density lipoprotein-derived cholesterol but not 25-hydroxycholesterol. ABCA2 decreased low-density lipoprotein receptor (LDLR) mRNA and protein levels and increased its turnover rate. The surface expression of LDLR as well as the uptake of fluroresecent DiI-LDL was also reduced by ABCA2. Reduction of endogenous ABCA2 expression by RNAi treatment of N2a cells and rat primary cortical neurons produced the opposite effects of over-expression of ABCA2, increasing LDLR protein levels. This report identifies ABCA2 as a key regulator of cholesterol homeostasis and LDLR metabolism in neuronal cells. PMID:21810484

  6. Domestic minor sex trafficking in the United States.

    PubMed

    Kotrla, Kimberly

    2010-04-01

    By now, most social workers are familiar with the issue of human trafficking. However, many are likely unfamiliar with research indicating that youths constitute the most vulnerable group in the United States for becoming victims of sex trafficking and that most women in prostitution actually entered as minors. Some experts are now referring to the sex trafficking of U.S. children and youths as "domestic minor sex trafficking," or DMST. This article seeks to acquaint readers with what is currently known regarding the extent of DMST, who is at risk for becoming a victim, and implications for the social work profession in addressing this tragedy.

  7. Domestic minor sex trafficking in the United States.

    PubMed

    Kotrla, Kimberly

    2010-04-01

    By now, most social workers are familiar with the issue of human trafficking. However, many are likely unfamiliar with research indicating that youths constitute the most vulnerable group in the United States for becoming victims of sex trafficking and that most women in prostitution actually entered as minors. Some experts are now referring to the sex trafficking of U.S. children and youths as "domestic minor sex trafficking," or DMST. This article seeks to acquaint readers with what is currently known regarding the extent of DMST, who is at risk for becoming a victim, and implications for the social work profession in addressing this tragedy. PMID:20408359

  8. 3 CFR - Continuation of the National Emergency With Respect to Significant Narcotics Traffickers Centered...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... to Significant Narcotics Traffickers Centered in Colombia Presidential Documents Other Presidential... Narcotics Traffickers Centered in Colombia On October 21, 1995, by Executive Order 12978, the President... economy of the United States constituted by the actions of significant narcotics traffickers centered...

  9. 3 CFR - Continuation of the National Emergency With Respect to Significant Narcotics Traffickers Centered...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... to Significant Narcotics Traffickers Centered in Colombia Presidential Documents Other Presidential... Narcotics Traffickers Centered in Colombia On October 21, 1995, by Executive Order 12978, the President... economy of the United States constituted by the actions of significant narcotics traffickers centered...

  10. 3 CFR - Continuation of the National Emergency With Respect to Significant Narcotics Traffickers Centered...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... to Significant Narcotics Traffickers Centered in Colombia Presidential Documents Other Presidential... Narcotics Traffickers Centered in Colombia On October 21, 1995, by Executive Order 12978, the President declared a national emergency with respect to significant narcotics traffickers centered in...

  11. Assisting victims of human trafficking: strategies to facilitate identification, exit from trafficking, and the restoration of wellness.

    PubMed

    Hodge, David R

    2014-04-01

    Human trafficking is a pressing social justice concern. Social work is uniquely situated to address this problem. However, despite the profession's commitment to social justice, the scholarship to equip social workers to address this issue has been largely absent from professional discourse. To address this gap, this article helps social work practitioners to assist victims of human trafficking. After orienting readers to the scope and process of human trafficking, the topics of victim identification, exit from trafficking, and the restoration of psychological wellness are discussed. By equipping themselves in these three areas, practitioners can advance social justice on behalf of some of the most exploited people in the world. PMID:24855860

  12. Assisting victims of human trafficking: strategies to facilitate identification, exit from trafficking, and the restoration of wellness.

    PubMed

    Hodge, David R

    2014-04-01

    Human trafficking is a pressing social justice concern. Social work is uniquely situated to address this problem. However, despite the profession's commitment to social justice, the scholarship to equip social workers to address this issue has been largely absent from professional discourse. To address this gap, this article helps social work practitioners to assist victims of human trafficking. After orienting readers to the scope and process of human trafficking, the topics of victim identification, exit from trafficking, and the restoration of psychological wellness are discussed. By equipping themselves in these three areas, practitioners can advance social justice on behalf of some of the most exploited people in the world.

  13. [A simple test for quantitative determination of LDL-cholesterol].

    PubMed

    Mertz, D P; Thuilot, G

    1986-05-01

    The subject of the report is a novel precipitation test for the quantitative recording of LDL cholesterol based on the precipitation of LDL by dextran sulphate. Parallel assays of LDL cholesterol according to the new method and using quantitative lipoprotein electrophoresis as reference showed the results, in terms of the individual values and collectively, to be practically identical for a wide concentration range of various lipids and lipoproteins in the serum. The concentration ratio of the means obtained according to the two methods is 1.014 +/- 0.102 (standard deviation). The regression function displays a correlation coefficient of 0.9470. Double assays with the new technique yield a variation coefficient of 1.7 +/- 0.4%. Limitations of the method, which are insignificant for application in practice, are pointed out. The new precipitation method is simple, safe and useful for the quantitative estimation of the LDL cholesterol concentration in freshly obtained human serum. The method requires only little time and equipment.

  14. Reduction of blood serum cholesterol

    NASA Technical Reports Server (NTRS)

    Winitz, M. (Inventor)

    1974-01-01

    By feeding a human subject as the sole source of sustenance a defined diet wherein the carbohydrate consists substantially entirely of glucose, maltose or a polysaccharide of glucose, the blood serum cholesterol level of the human subject is substantially reduced. If 25 percent of the carbohydrate is subsequently supplied in the form of sucrose, an immediate increase from the reduced level is observed. The remainder of the defined diet normally includes a source of amino acids, such as protein or a protein hydrolysate, vitamins, minerals and a source of essential fatty acid.

  15. Ganglioside Regulation of AMPA Receptor Trafficking

    PubMed Central

    Prendergast, Jillian; Umanah, George K.E.; Yoo, Seung-Wan; Lagerlöf, Olof; Motari, Mary G.; Cole, Robert N.; Huganir, Richard L.; Dawson, Ted M.; Dawson, Valina L.

    2014-01-01

    Gangliosides are major cell-surface determinants on all vertebrate neurons. Human congenital disorders of ganglioside biosynthesis invariably result in intellectual disability and are often associated with intractable seizures. To probe the mechanisms of ganglioside functions, affinity-captured ganglioside-binding proteins from rat cerebellar granule neurons were identified by quantitative proteomic mass spectrometry. Of the six proteins that bound selectively to the major brain ganglioside GT1b (GT1b:GM1 > 4; p < 10−4), three regulate neurotransmitter receptor trafficking: Thorase (ATPase family AAA domain-containing protein 1), soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (γ-SNAP), and the transmembrane protein Nicalin. Thorase facilitates endocytosis of GluR2 subunit-containing AMPA-type glutamate receptors (AMPARs) in an ATPase-dependent manner; its deletion in mice results in learning and memory deficits (J. Zhang et al., 2011b). GluR2-containing AMPARs did not bind GT1b, but bound specifically to another ganglioside, GM1. Addition of noncleavable ATP (ATPγS) significantly disrupted ganglioside binding, whereas it enhanced AMPAR association with Thorase, NSF, and Nicalin. Mutant mice lacking GT1b expressed markedly higher brain Thorase, whereas Thorase-null mice expressed higher GT1b. Treatment of cultured hippocampal neurons with sialidase, which cleaves GT1b (and other sialoglycans), resulted in a significant reduction in the size of surface GluR2 puncta. These data support a model in which GM1-bound GluR2-containing AMPARs are functionally segregated from GT1b-bound AMPAR-trafficking complexes. Release of ganglioside binding may enhance GluR2-containing AMPAR association with its trafficking complexes, increasing endocytosis. Disrupting ganglioside biosynthesis may result in reduced synaptic expression of GluR2-contianing AMPARs resulting in intellectual deficits and seizure susceptibility in mice and humans. PMID:25253868

  16. Autophagy and proteins involved in vesicular trafficking.

    PubMed

    Amaya, Celina; Fader, Claudio Marcelo; Colombo, María Isabel

    2015-11-14

    Autophagy is an intracellular degradation system that, as a basic mechanism it delivers cytoplasmic components to the lysosomes in order to maintain adequate energy levels and cellular homeostasis. This complex cellular process is activated by low cellular nutrient levels and other stress situations such as low ATP levels, the accumulation of damaged proteins or organelles, or pathogen invasion. Autophagy as a multistep process involves vesicular transport events leading to tethering and fusion of autophagic vesicles with several intracellular compartments. This review summarizes our current understanding of the autophagic pathway with emphasis in the trafficking machinery (i.e. Rabs GTPases and SNAP receptors (SNAREs)) involved in specific steps of the pathway.

  17. Plant vacuole morphology and vacuolar trafficking

    PubMed Central

    Zhang, Chunhua; Hicks, Glenn R.; Raikhel, Natasha V.

    2014-01-01

    Plant vacuoles are essential organelles for plant growth and development, and have multiple functions. Vacuoles are highly dynamic and pleiomorphic, and their size varies depending on the cell type and growth conditions. Vacuoles compartmentalize different cellular components such as proteins, sugars, ions and other secondary metabolites and play critical roles in plants response to different biotic/abiotic signaling pathways. In this review, we will summarize the patterns of changes in vacuole morphology in certain cell types, our understanding of the mechanisms of plant vacuole biogenesis, and the role of SNAREs and Rab GTPases in vacuolar trafficking. PMID:25309565

  18. Cholesterol Oxidation in Fish and Fish Products.

    PubMed

    Dantas, Natalie Marinho; Sampaio, Geni Rodrigues; Ferreira, Fernanda Silva; Labre, Tatiana da Silva; Torres, Elizabeth Aparecida Ferraz da Silva; Saldanha, Tatiana

    2015-12-01

    Fish and fish products are important from a nutritional point of view due to the presence of high biological value proteins and the high content of polyunsaturated fatty acids, especially those of the n-3 series, and above all eicosapentaenoic acid and docosahexaenoic acid. However, these important food products also contain significant amounts of cholesterol. Although cholesterol participates in essential functions in the human body, it is unstable, especially in the presence of light, oxygen, radiation, and high temperatures that can cause the formation of cholesterol oxidation products or cholesterol oxides, which are prejudicial to human health. Fish processing involves high and low temperatures, as well as other methods for microbiological control, which increases shelf life and consequently added value; however, such processes favor the formation of cholesterol oxidation products. This review brings together data on the formation of cholesterol oxides during the preparation and processing of fish into food products which are recognized and recommended for their nutritional properties.

  19. Effects of cholesterol on plasma membrane lipid order in MCF-7 cells by two-photon microscopy

    NASA Astrophysics Data System (ADS)

    Zeng, Yixiu; Chen, Jianling; Yang, Hongqin; Wang, Yuhua; Li, Hui; Xie, Shusen

    2014-09-01

    Lipid rafts are cholesterol- and glycosphingolipids- enriched microdomains on plasma membrane surface of mammal cells, involved in a variety of cellular processes. Depleting cholesterol from the plasma membrane by drugs influences the trafficking of lipid raft markers. Optical imaging techniques are powerful tools to study lipid rafts in live cells due to its noninvasive feature. In this study, breast cancer cells MCF-7 were treated with different concentrations of MβCD to deplete cholesterol and an environmentally sensitive fluorescence probe, Laurdan was loaded to image lipid order by two-photon microscopy. The generalized polarization (GP) values were calculated to distinguish the lipid order and disorder phase. GP images and GP distributions of native and cholesterol-depleted MCF-7 cells were obtained. Our results suggest that even at low concentration (0.5 mM) of MβCD, the morphology of the MCF-7 cells changes. Small high GP areas (lipid order phase) decrease more rapidly than low GP areas (lipid disorder phase), indicating that lipid raft structure was altered more severely than nonraft domains. The data demonstrates that cholesterol dramatically affect raft coverage and plasma membrane fluidity in living cells.

  20. Macrophage-mediated cholesterol handling in atherosclerosis.

    PubMed

    Chistiakov, Dimitry A; Bobryshev, Yuri V; Orekhov, Alexander N

    2016-01-01

    Formation of foam cells is a hallmark at the initial stages of atherosclerosis. Monocytes attracted by pro-inflammatory stimuli attach to the inflamed vascular endothelium and penetrate to the arterial intima where they differentiate to macrophages. Intimal macrophages phagocytize oxidized low-density lipoproteins (oxLDL). Several scavenger receptors (SR), including CD36, SR-A1 and lectin-like oxLDL receptor-1 (LOX-1), mediate oxLDL uptake. In late endosomes/lysosomes of macrophages, oxLDL are catabolysed. Lysosomal acid lipase (LAL) hydrolyses cholesterol esters that are enriched in LDL to free cholesterol and free fatty acids. In the endoplasmic reticulum (ER), acyl coenzyme A: cholesterol acyltransferase-1 (ACAT1) in turn catalyses esterification of cholesterol to store cholesterol esters as lipid droplets in the ER of macrophages. Neutral cholesteryl ester hydrolases nCEH and NCEH1 are involved in a secondary hydrolysis of cholesterol esters to liberate free cholesterol that could be then out-flowed from macrophages by cholesterol ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 and SR-BI. In atherosclerosis, disruption of lipid homoeostasis in macrophages leads to cholesterol accumulation and formation of foam cells. PMID:26493158

  1. Special parallel processing workshop

    SciTech Connect

    1994-12-01

    This report contains viewgraphs from the Special Parallel Processing Workshop. These viewgraphs deal with topics such as parallel processing performance, message passing, queue structure, and other basic concept detailing with parallel processing.

  2. 31 CFR 536.312 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designated narcotics trafficker means: (a) Persons listed in the annex to Executive Order 12978 (3 CFR, 1995... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING...

  3. 31 CFR 536.312 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designated narcotics trafficker means: (a) Persons listed in the annex to Executive Order 12978 (3 CFR, 1995... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING...

  4. 31 CFR 536.312 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... designated narcotics trafficker means: (a) Persons listed in the annex to Executive Order 12978 (3 CFR, 1995... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING...

  5. 31 CFR 536.312 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... designated narcotics trafficker means: (a) Persons listed in the annex to Executive Order 12978 (3 CFR, 1995... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NARCOTICS TRAFFICKING...

  6. Adolescent Black Males' Drug Trafficking and Addiction: Three Theoretical Perspectives.

    ERIC Educational Resources Information Center

    Moore, Sharon E.

    1995-01-01

    Explains the incidence and nature of drug trafficking and chemical dependency among adolescent black males. The paper also discusses the social science theories of Emile Durkheim, Karl Marx, and Molefi Asante to better understand the behaviors, and the consequences of those behaviors, of young black males who participate in drug trafficking. (GR)

  7. 78 FR 59317 - Federal Acquisition Regulation; Ending Trafficking in Persons

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ... INFORMATION: I. Background The United States has long had a zero-tolerance policy regarding Government... subjection to involuntary servitude, peonage, debt bondage, or slavery, and sex trafficking. As the largest... (77 FR 60029, October 2, 2012), and Title XVII, entitled ``Ending Trafficking in...

  8. Protein kinesis: The dynamics of protein trafficking and stability

    SciTech Connect

    1995-12-31

    The purpose of this conference is to provide a multidisciplinary forum for exchange of state-of-the-art information on protein kinesis. This volume contains abstracts of papers in the following areas: protein folding and modification in the endoplasmic reticulum; protein trafficking; protein translocation and folding; protein degradation; polarity; nuclear trafficking; membrane dynamics; and protein import into organelles.

  9. Aggression in Sexually Abused Trafficked Girls and Efficacy of Intervention

    ERIC Educational Resources Information Center

    Deb, Sibnath; Mukherjee, Aparna; Mathews, Ben

    2011-01-01

    The broad objective of this study was to understand the incidence and severity of aggression among sexually abused girls who were trafficked and who were then further used for commercial sexual exploitation (referred to subsequently as sexually abused trafficked girls). In addition, the impact of counseling for minimizing aggression in these girls…

  10. Domestic Minor Sex Trafficking in the United States

    ERIC Educational Resources Information Center

    Kotrla, Kimberly

    2010-01-01

    By now, most social workers are familiar with the issue of human trafficking. However, many are likely unfamiliar with research indicating that youths constitute the most vulnerable group in the United States for becoming victims of sex trafficking and that most women in prostitution actually entered as minors. Some experts are now referring to…

  11. Teaching about Trafficking: Opportunities and Challenges for Critical Engagement

    ERIC Educational Resources Information Center

    Dragiewicz, Molly

    2008-01-01

    The author came to know about trafficking by accident, when she was hired as a research assistant at The Protection Project (TPP) in 1999. As a feminist teacher, the author was very aware of the divisions among feminists on the subject of trafficking, and was interested in communicating these differences to students who were not well versed in the…

  12. Rapid labeling of lipoproteins in plasma with radioactive cholesterol. Application for measurement of plasma cholesterol esterification

    SciTech Connect

    Yen, F.T.; Nishida, T. )

    1990-02-01

    In order to efficiently and rapidly label lipoproteins in plasma with ({sup 3}H)cholesterol, micelles consisting of lysophosphatidylcholine (lysoPC) and ({sup 3}H)cholesterol (molar ratio, 50:1) were prepared. When trace amounts of these micelles were injected into plasma, ({sup 3}H)cholesterol rapidly equilibrated among the plasma lipoproteins, as compared to ({sup 3}H)cholesterol from an albumin-stabilized emulsion. The distributions of both ({sup 3}H)cholesterol and unlabeled free cholesterol in plasma lipoproteins were similar in labeled plasma samples. This method of labeling can be used for the measurement of cholesterol esterification, or lecithin:cholesterol acyltransferase activity, in small amounts (20-40 microliters) of plasma samples.

  13. Black pepper and piperine reduce cholesterol uptake and enhance translocation of cholesterol transporter proteins.

    PubMed

    Duangjai, Acharaporn; Ingkaninan, Kornkanok; Praputbut, Sakonwun; Limpeanchob, Nanteetip

    2013-04-01

    Black pepper (Piper nigrum L.) lowers blood lipids in vivo and inhibits cholesterol uptake in vitro, and piperine may mediate these effects. To test this, the present study aimed to compare actions of black pepper extract and piperine on (1) cholesterol uptake and efflux in Caco-2 cells, (2) the membrane/cytosol distribution of cholesterol transport proteins in these cells, and (3) the physicochemical properties of cholesterol micelles. Piperine or black pepper extract (containing the same amount of piperine) dose-dependently reduced cholesterol uptake into Caco-2 cells in a similar manner. Both preparations reduced the membrane levels of NPC1L1 and SR-BI proteins but not their overall cellular expression. Micellar cholesterol solubility of lipid micelles was unaffected except by 1 mg/mL concentration of black pepper extract. These data suggest that piperine is the active compound in black pepper and reduces cholesterol uptake by internalizing the cholesterol transporter proteins.

  14. Liquid disordered-liquid ordered phase coexistence in bicelles containing unsaturated lipids and cholesterol.

    PubMed

    Schmidt, Miranda L; Davis, James H

    2016-04-01

    Magnetically orienting bicelles are often made by combining the long chain phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) with the short chain phospholipid 1,2-dicaproyl-sn-glycero-3-phosphocholine (DCPC) in buffer. These bicelles orient with their bilayer normals perpendicular to the external magnetic field. We have examined the phase behaviour of DMPC/DCPC bicelles and the effects of cholesterol and the unsaturated phospholipid 1,2-dipalmitoleoyl-sn-glycero-3-phosphocholine (DPoPC) as a function of temperature using static solid state (2)H nuclear magnetic resonance spectroscopy. As expected, cholesterol has an ordering effect on the long phospholipid chains and this is reflected in the phase behaviour of the bicelle mixtures. Liquid disordered-liquid ordered, fluid-fluid phase coexistence is observed in DMPC/cholesterol/DCPC bicelles with cholesterol mole fractions of 0.13 and higher. DPoPC/DMPC/cholesterol/DCPC bicelles also exhibit two fluid phase coexistence over a broad range of temperatures and compositions. Bicelles can provide a useful medium in which to study membrane bound peptides and proteins. The orientation parallel to the magnetic field is favourable for studying membrane peptides/proteins because information about the orientation of relevant molecular bonds or internuclear vectors can be obtained directly from the resulting (2)H spectra. Lanthanide ions can be used to flip the bicelles to have their bilayer normals parallel to the external magnetic field. Yb(3+) was used to flip the DPoPC/DMPC/cholesterol/DCPC bicelles while Eu(3+) was found to be ineffective at flipping bicelles containing cholesterol in the present work.

  15. Vesicle trafficking in plant immune responses.

    PubMed

    Robatzek, Silke

    2007-01-01

    In plants, perception of pathogen-associated molecular patterns at the surface is the first line of defence in cellular immunity. This review summarizes recent evidence of the involvement of vesicle trafficking in the plant's immune response against pathogens. I first discuss aspects of ligand-stimulated receptor endocytosis. The best-characterized pattern-recognition receptor (PRR), FLS2, is a transmembrane leucine-rich repeat receptor kinase that recognizes bacterial flagellin. FLS2 was recently shown to undergo internalization upon activation with its cognate ligand. An animal PRR, TLR4 that mediates perception of bacterial-derived lipopolysaccharides, similarly exhibits ligand-stimulated endocytosis. The second focus is N-ethylmaleimide-sensitive factor adaptor protein receptor (SNARE)-mediated immunity involving syntaxins and their cognate partners. One of the genes involved in basal immunity in Arabidopsis, PEN1, encodes a syntaxin that focally accumulates at fungal penetration sites, raising the possibility that induced exocytosis is important for active defence. Pathogen-triggered endocytic and exocytic processes have to be balanced to ensure host cell homeostasis. Thus, understanding how phytopathogens have evolved strategies to exploit host cell vesicle trafficking to manipulate immune responses is currently an area of intense study. PMID:17081192

  16. Trafficking of Estrella lausannensis in human macrophages.

    PubMed

    Rusconi, Brigida; Kebbi-Beghdadi, Carole; Greub, Gilbert

    2015-07-01

    Estrella lausannensis is a new member of the Chlamydiales order. Like other Chlamydia-related bacteria, it is able to replicate in amoebae and in fish cell lines. A preliminary study investigating the pathogenic potential of Chlamydia-related bacteria found a correlation between antibody response to E. lausannensis and pneumonia in children. To further investigate the pathogenic potential of E. lausannensis, we determined its ability to grow in human macrophages and its intracellular trafficking. The replication in macrophages resulted in viable E. lausannensis; however, it caused a significant cytopathic effect. The intracellular trafficking of E. lausannensis was analyzed by determining the interaction of the Estrella-containing inclusions with various endocytic markers as well as host organelles. The E. lausannensis inclusion escaped the endocytic pathway rapidly avoiding maturation into phagolysosomes by preventing both EEA-1 and LAMP-1 accumulation. Compared to Waddlia chondrophila, another Chlamydia-related bacteria, the recruitment of mitochondria and endoplasmic reticulum was minimal for E. lausannensis inclusions. Estrella lausannensis appears to use a distinct source of nutrients and energy compared to other members of the Chlamydiales order. In conclusion, we hypothesize that E. lausannensis has a restricted growth in human macrophages, due to its reduced capacity to control programmed cell death. PMID:25857735

  17. Secretory protein trafficking in Giardia intestinalis.

    PubMed

    Hehl, Adrian B; Marti, Matthias

    2004-07-01

    Early diverged extant organisms, which may serve as convenient laboratory models to look for and study evolutionary ancient features of eukaryotic cell biology, are rare. The diplomonad Giardia intestinalis, a protozoan parasite known to cause diarrhoeal disease, has become an increasingly popular object of basic research in cell biology, not least because of a genome sequencing project nearing completion. Commensurate with its phylogenetic status, the Giardia trophozoite has a very basic secretory system and even lacks hallmark structures such as a morphologically identifiable Golgi apparatus. The cell's capacity for protein sorting is nevertheless unimpeded, exemplified by its ability to cope with massive amounts of newly synthesized cyst wall proteins and glycans, which are sorted to dedicated Golgi-like compartments termed encystation-specific vesicles (ESVs) generated from endoplasmic reticulum (ER)-derived transport intermediates. This soluble bulk cargo is kept strictly separate from constitutively transported variant surface proteins during export, a function that is dependent on the stage-specific recognition of trafficking signals. Encysting Giardia therefore provide a unique system for the study of unconventional, Golgi-independent protein trafficking mechanisms in the broader context of eukaryotic endomembrane organization and evolution. PMID:15225300

  18. Pigs fed cholesterol neonatally have increased cerebrum cholesterol as young adults.

    PubMed

    Boleman, S L; Graf, T L; Mersmann, H J; Su, D R; Krook, L P; Savell, J W; Park, Y W; Pond, W G

    1998-12-01

    Sixty-eight female neonatal pigs selected for seven (Experiment 1) or eight (Experiment 2) generations for high (HG) or low (LG) plasma cholesterol were used to test the hypothesis that neonatal dietary cholesterol fed during the first 4 or 8 wk of postnatal life increases the cholesterol content of the cerebrum in young adulthood following free access to a high-fat (15%), high-cholesterol (0.5%) diet from 8 to 20 or 24 wk of age. Pigs were removed from their dams at 1 d of age and given free access to a sow-milk replacer diet containing 9.5% coconut fat and 0 or 0.5 % cholesterol. All pigs (except four HG and four LG pigs in Experiment 2, which were deprived of cholesterol throughout the study) were fed the high-fat, high-cholesterol diet from 8 wk to termination at 20 or 24 wk of age. Cerebrum weight and cholesterol concentration were higher in pigs fed cholesterol neonatally than in those deprived of cholesterol neonatally in both experiments, but weight and cholesterol concentration were unaffected by genetic line. Cholesterol concentrations in longissimus and semitendinosus muscles and in subcutaneous fat were unaffected by diet or genetic line. We conclude that dietary cholesterol deprivation during the first 4 to 8 wk of life in piglets is associated with lower cholesterol concentration and total content in the young adult cerebrum than in pigs supplemented with cholesterol in early life. These data support previous observations and suggest the possibility of a metabolic need for neonatal dietary cholesterol in normal brain development. PMID:9868199

  19. Entrapment and Enmeshment Schemes Used by Sex Traffickers.

    PubMed

    Reid, Joan A

    2016-09-01

    Emerging research suggests that sex traffickers/pimps control the majority of trafficked girls in the United States. The youthfulness of these victims and their lack of psychosocial maturity severely diminish their ability to detect exploitative motives or withstand manipulation of traffickers. A review of 43 cases of sexually exploited girls involving non-relative traffickers and 10 semi-structured interviews with social service providers revealed numerous scripts and schemes used by sex traffickers to entrap and entangle victims including boyfriend/lover scripts, ruses involving debt bondage, friendship or faux-family scripts, threats of forced abortion or to take away children, and coerced co-offending. These findings inform potential prevention efforts and highlight the need for multi-systemic, victim-centered approaches to intervention. PMID:25079777

  20. Entrapment and Enmeshment Schemes Used by Sex Traffickers.

    PubMed

    Reid, Joan A

    2016-09-01

    Emerging research suggests that sex traffickers/pimps control the majority of trafficked girls in the United States. The youthfulness of these victims and their lack of psychosocial maturity severely diminish their ability to detect exploitative motives or withstand manipulation of traffickers. A review of 43 cases of sexually exploited girls involving non-relative traffickers and 10 semi-structured interviews with social service providers revealed numerous scripts and schemes used by sex traffickers to entrap and entangle victims including boyfriend/lover scripts, ruses involving debt bondage, friendship or faux-family scripts, threats of forced abortion or to take away children, and coerced co-offending. These findings inform potential prevention efforts and highlight the need for multi-systemic, victim-centered approaches to intervention.

  1. The role of the nurse in combating human trafficking.

    PubMed

    Sabella, Donna

    2011-02-01

    Human trafficking, also called modern slavery, happens worldwide--and the United States is no exception. Within our borders, thousands of foreign nationals and U.S. citizens, many of them children, are forced or coerced into sex work or various forms of labor every year. Nurses and other health care providers who encounter victims of trafficking often don't realize it, and opportunities to intervene are lost. Although no one sign can demonstrate with certainty when someone is being trafficked, there are several indicators that clinicians should know. This article provides an overview of human trafficking, describes how to recognize signs that a person is being trafficked and how to safely intervene, and offers an extensive resource list.

  2. The role of the nurse in combating human trafficking.

    PubMed

    Sabella, Donna

    2011-02-01

    Human trafficking, also called modern slavery, happens worldwide--and the United States is no exception. Within our borders, thousands of foreign nationals and U.S. citizens, many of them children, are forced or coerced into sex work or various forms of labor every year. Nurses and other health care providers who encounter victims of trafficking often don't realize it, and opportunities to intervene are lost. Although no one sign can demonstrate with certainty when someone is being trafficked, there are several indicators that clinicians should know. This article provides an overview of human trafficking, describes how to recognize signs that a person is being trafficked and how to safely intervene, and offers an extensive resource list. PMID:21270581

  3. Human trafficking: the role of the health care provider.

    PubMed

    Dovydaitis, Tiffany

    2010-01-01

    Human trafficking is a major public health problem, both domestically and internationally. Health care providers are often the only professionals to interact with trafficking victims who are still in captivity. The expert assessment and interview skills of providers contribute to their readiness to identify victims of trafficking. The purpose of this article is to provide clinicians with knowledge on trafficking and give specific tools that they may use to assist victims in the clinical setting. Definitions, statistics, and common health care problems of trafficking victims are reviewed. The role of the health care provider is outlined through a case study and clinical practice tools are provided. Suggestions for future research are also briefly addressed. PMID:20732668

  4. Psychological Coercion in Human Trafficking: An Application of Biderman's Framework.

    PubMed

    Baldwin, Susie B; Fehrenbacher, Anne E; Eisenman, David P

    2015-09-01

    This study examined coercive conditions experienced by trafficked persons in the context of Biderman's theory of coercion. We conducted semi-structured interviews with 12 adult women trafficked into Los Angeles County, from 10 countries, for domestic work and/or sex work. Participants described health problems they experienced in relation to their trafficking experience and their perceptions of conditions that caused health problems. Utilizing a framework analysis approach, we analyzed themes using Biderman's framework. Participants reported experiencing the range of nonphysical coercive tactics outlined by Biderman, including isolation, monopolization of perception, induced debility or exhaustion, threats, occasional indulgences, demonstration of omnipotence, degradation, and enforcement of trivial demands. Our analysis demonstrates how these coercion tactics reinforced the submission of trafficked persons to their traffickers even in the absence of physical force or restraints. Such psychological abuse creates extreme stress that can lead to acute and chronic, physical and mental health problems. PMID:25371382

  5. Human Trafficking: The Role of the Health Care Provider

    PubMed Central

    Dovydaitis, Tiffany

    2011-01-01

    Human trafficking is a major public health problem, both domestically and internationally. Health care providers are often the only professionals to interact with trafficking victims who are still in captivity. The expert assessment and interview skills of providers contribute to their readiness to identify victims of trafficking. The purpose of this article is to provide clinicians with knowledge on trafficking and give specific tools that they may use to assist victims in the clinical setting. Definitions, statistics, and common health care problems of trafficking victims are reviewed. The role of the health care provider is outlined through a case study and clinical practice tools are provided. Suggestions for future research are also briefly addressed. PMID:20732668

  6. New Insights into How Trafficking Regulates T Cell Receptor Signaling

    PubMed Central

    Lou, Jieqiong; Rossy, Jérémie; Deng, Qiji; Pageon, Sophie V.; Gaus, Katharina

    2016-01-01

    There is emerging evidence that exocytosis plays an important role in regulating T cell receptor (TCR) signaling. The trafficking molecules involved in lytic granule (LG) secretion in cytotoxic T lymphocytes (CTL) have been well-studied due to the immune disorder known as familial hemophagocytic lymphohistiocytosis (FHLH). However, the knowledge of trafficking machineries regulating the exocytosis of receptors and signaling molecules remains quite limited. In this review, we summarize the reported trafficking molecules involved in the transport of the TCR and downstream signaling molecules to the cell surface. By combining this information with the known knowledge of LG exocytosis and general exocytic trafficking machinery, we attempt to draw a more complete picture of how the TCR signaling network and exocytic trafficking matrix are interconnected to facilitate T cell activation. This also highlights how membrane compartmentalization facilitates the spatiotemporal organization of cellular responses that are essential for immune functions. PMID:27508206

  7. Cholesterol Lowering Effect of Plant Stanol Ester Yoghurt Drinks with Added Camelina Oil

    PubMed Central

    Salo, Pia; Kuusisto, Päivi

    2016-01-01

    The aim of this study was to investigate the effects of yoghurt minidrinks containing two doses of plant stanol ester either with or without added camelina oil on the serum cholesterol levels in moderately hypercholesterolemic subjects. In this randomised, double-blind, parallel group study, 143 subjects consumed a 65 mL minidrink together with a meal daily for four weeks. The minidrink contained 1.6 or 2.0 grams of plant stanols with or without 2 grams of alpha-linolenic acid-rich camelina oil. The placebo minidrink did not contain plant stanols or camelina oil. All plant stanol treated groups showed statistically significant total, LDL, and non-HDL cholesterol lowering relative to baseline and relative to placebo. Compared to placebo, LDL cholesterol was lowered by 9.4% (p < 0.01) and 8.1% (p < 0.01) with 1.6 g and 2 g plant stanols, respectively. With addition of Camelina oil, 1.6 g plant stanols resulted in 11.0% (p < 0.01) and 2 g plant stanols in 8.4% (p < 0.01) reduction in LDL cholesterol compared to placebo. In conclusion, yoghurt minidrinks with plant stanol ester reduced serum LDL cholesterol significantly and addition of a small amount of camelina oil did not significantly enhance the cholesterol lowering effect. This trial was registered with ClinicalTrials.gov NCT02628990. PMID:26998355

  8. Neonatal dietary cholesterol and alleles of cholesterol 7-alpha hydroxylase affect piglet cerebrum weight, cholesterol concentration, and behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This experiment was designed to test the effect of polymorphism in the cholesterol 7-alpha hydroxylase (CYP7) gene locus, and dietary cholesterol (C) on cerebrum C in neonatal pigs fed sow's milk formulas. Thirty-six pigs (18 male and 18 female) genetically selected for high (HG), or low (LG) plasma...

  9. Illicit trafficking of radiological & nuclear materials : modeling and analysis of trafficking trends and risks.

    SciTech Connect

    York, David L.; Love, Tracia L.; Rochau, Gary Eugene

    2005-01-01

    Concerns over the illicit trafficking of radiological and nuclear materials were focused originally on the lack of security and accountability of such material throughout the former Soviet states. This is primarily attributed to the frequency of events that have occurred involving the theft and trafficking of critical material components that could be used to construct a Radiological Dispersal Device (RDD) or even a rudimentary nuclear device. However, with the continued expansion of nuclear technology and the deployment of a global nuclear fuel cycle these materials have become increasingly prevalent, affording a more diverse inventory of dangerous materials and dual-use items. To further complicate the matter, the list of nuclear consumers has grown to include: (1) Nation-states that have gone beyond the IAEA agreed framework and additional protocols concerning multiple nuclear fuel cycles and processes that reuse the fuel through reprocessing to exploit technologies previously confined to the more industrialized world; (2) Terrorist organizations seeking to acquire nuclear and radiological material due to the potential devastation and psychological effect of their use; (3) Organized crime, which has discovered a lucrative market in trafficking of illicit material to international actors and/or countries; and (4) Amateur smugglers trying to feed their families in a post-Soviet era. An initial look at trafficking trends of this type seems scattered and erratic, localized primarily to a select group of countries. This is not necessarily the case. The success with which other contraband has been smuggled throughout the world suggests that nuclear trafficking may be carried out with relative ease along the same routes by the same criminals or criminal organizations. Because of the inordinately high threat posed by terrorist or extremist groups acquiring the ingredients for unconventional weapons, it is necessary that illicit trafficking of these materials be better

  10. Hyperinsulinemia and skeletal muscle fatty acid trafficking.

    PubMed

    Kanaley, Jill A; Shadid, Samyah; Sheehan, Michael T; Guo, ZengKui; Jensen, Michael D

    2013-08-15

    We hypothesized that insulin alters plasma free fatty acid (FFA) trafficking into intramyocellular (im) long-chain acylcarnitines (imLCAC) and triglycerides (imTG). Overnight-fasted adults (n = 41) received intravenous infusions of [U-¹³C]palmitate (0400-0900 h) and [U-¹³C]oleate (0800-1400 h) to label imTG and imLCAC. A euglycemic-hyperinsulinemic (1.0 mU·kg fat-free mass⁻¹·min⁻¹) clamp (0800-1400 h) and two muscle biopsies (0900 h, 1400 h) were performed. The patterns of [U-¹³C]palmitate incorporation into imTG-palmitate and palmitoylcarnitine were similar to those we reported in overnight postabsorptive adults (saline control); the intramyocellular palmitoylcarnitine enrichment was not different from and correlated with imTG-palmitate enrichment for both the morning (r = 0.38, P = 0.02) and afternoon (r = 0.44, P = 0.006) biopsy samples. Plasma FFA concentrations, flux, and the incorporation of plasma oleate into imTG-oleate during hyperinsulinemia were ~1/10th of that observed in the previous saline control studies (P < 0.001). At the time of the second biopsy, the enrichment in oleoylcarnitine was <25% of that in imTG-oleate and was not correlated with imTG-oleate enrichment. The intramyocellular nonesterified fatty acid-palmitate-to-imTG-palmitate enrichment ratio was greater (P < 0.05) in women than men, suggesting that sex differences in intramyocellular palmitate trafficking may occur under hyperinsulinemic conditions. We conclude that plasma FFA trafficking into imTG during hyperinsulinemia is markedly suppressed, and these newly incorporated FFA fatty acids do not readily enter the LCAC preoxidative pools. Hyperinsulinemia does not seem to inhibit the entry of fatty acids from imTG pools that were labeled under fasting conditions, possibly reflecting the presence of two distinct imTG pools that are differentially regulated by insulin. PMID:23820622

  11. Total cholesterol, low density lipoprotein cholesterol, and high density lipoprotein cholesterol and coronary heart disease in Scotland.

    PubMed Central

    Hargreaves, A D; Logan, R L; Thomson, M; Elton, R A; Oliver, M F; Riemersma, R A

    1991-01-01

    OBJECTIVE--To investigate long term changes in total cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol concentrations and in measures of other risk factors for coronary heart disease and to assess their importance for the development of coronary heart disease in Scottish men. DESIGN--Longitudinal study entailing follow up in 1988-9 of men investigated during a study in 1976. SETTING--Edinburgh, Scotland. SUBJECTS--107 men from Edinburgh who had taken part in a comparative study of risk factors for heart disease with Swedish men in 1976 when aged 40. INTERVENTION--The men were invited to attend a follow up clinic in 1988-9 for measurement of cholesterol concentrations and other risk factor measurements. Eighty three attended and 24 refused to or could not attend. MAIN OUTCOME MEASURES--Changes in total cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol concentrations, body weight, weight to height index, prevalence of smoking, and alcohol intake; number of coronary artery disease events. RESULTS--Mean serum total cholesterol concentration increased over the 12 years mainly due to an increase in the low density lipoprotein cholesterol fraction (from 3.53 (SD 0.09) to 4.56 (0.11) mmol/l) despite a reduction in high density lipoprotein cholesterol concentration. Body weight and weight to height index increased. Fewer men smoked more than 15 cigarettes/day in 1988-9 than in 1976. Blood pressure remained stable and fasting triglyceride concentrations did not change. The frequency of corneal arcus doubled. Alcohol consumption decreased significantly. Eleven men developed clinical coronary heart disease. High low density lipoprotein and low high density lipoprotein cholesterol concentrations in 1976, but not total cholesterol concentration, significantly predicted coronary heart disease (p = 0.05). Almost all of the men who developed coronary heart disease were smokers (91% v 53%, p less than

  12. Prosopis farcta beans increase HDL cholesterol and decrease LDL cholesterol in ostriches (Struthio camelus).

    PubMed

    Omidi, Arash; Ansari nik, Hossein; Ghazaghi, Mahmood

    2013-02-01

    Ten blue-neck male ostriches (Struthio camelus) were fed Prosopis farcta beans throughout a 30-day experiment. Blood samples were collected from ostriches on days 0 and 30 to measure levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, total serum protein, albumin, globulin, cholesterol, calcium, inorganic phosphorus, the activity of aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transferase (γ-GT). From days 0 to 30, HDL cholesterol, total protein, and globulins levels increased significantly whereas LDL cholesterol, inorganic phosphorus, and γ-GT activity decreased significantly.

  13. Dysregulation of Plasmalogen Homeostasis Impairs Cholesterol Biosynthesis.

    PubMed

    Honsho, Masanori; Abe, Yuichi; Fujiki, Yukio

    2015-11-27

    Plasmalogen biosynthesis is regulated by modulating fatty acyl-CoA reductase 1 stability in a manner dependent on cellular plasmalogen level. However, physiological significance of the regulation of plasmalogen biosynthesis remains unknown. Here we show that elevation of the cellular plasmalogen level reduces cholesterol biosynthesis without affecting the isoprenylation of proteins such as Rab and Pex19p. Analysis of intermediate metabolites in cholesterol biosynthesis suggests that the first oxidative step in cholesterol biosynthesis catalyzed by squalene monooxygenase (SQLE), an important regulator downstream HMG-CoA reductase in cholesterol synthesis, is reduced by degradation of SQLE upon elevation of cellular plasmalogen level. By contrast, the defect of plasmalogen synthesis causes elevation of SQLE expression, resulting in the reduction of 2,3-epoxysqualene required for cholesterol synthesis, hence implying a novel physiological consequence of the regulation of plasmalogen biosynthesis.

  14. Cholesterol-lowering effect of plant sterols.

    PubMed

    AbuMweis, Suhad S; Jones, Peter J H

    2008-12-01

    Plant sterols are plant components that have a chemical structure similar to cholesterol except for the addition of an extra methyl or ethyl group; however, plant sterol absorption in humans is considerably less than that of cholesterol. In fact, plant sterols reduce cholesterol absorption and thus reduce circulating levels of cholesterol. Earlier studies that have tested the efficacy of plant sterols as cholesterol-lowering agents incorporated plant sterols into fat spreads. Later on, plant sterols were added to other food matrices, including juices, nonfat beverages, milk and yogurt, cheese, meat, croissants and muffins, and cereal and chocolate bars. The beneficial physiologic effects of plant sterols could be further enhanced by combining them with other beneficial substances, such as olive and fish oils, fibers, and soy proteins, or with exercise. The addition of plant sterols to the diet is suggested by health experts as a safe and effective way to reduce the risk of coronary heart disease. PMID:18937893

  15. Cholesterol granulomas in three meerkats (Suricata suricatta).

    PubMed

    Sladky, K K; Dalldorf, F G; Steinberg, H; Wright, J F; Loomis, M R

    2000-11-01

    Cholesterol granulomas are uncommon pathologic lesions in animals, although they are important intracranial tumors in humans. This report describes cholesterol granulomas associated with multiple organ systems of three captive meerkats. In the most severe case, meerkat No. 1, the pathologic behavior of the cholesterol granuloma was unique in that it appeared to locally invade the cerebrum and calvarium, possibly contributing to neurological deficits observed antemortem. A review of other meerkat necropsies revealed incidental, asymptomatic cholesterol granulomas in organs of two other individuals, meerkat Nos. 2 and 3. Histologically, all lesions were composed of cholesterol clefts admixed with large, foamy macrophages containing hemosiderin, multinucleated giant cells, lymphocytes, plasma cells, and foci of mineralization. Hypercholesterolemia was documented in two of the three meerkats.

  16. Cholesterol granulomas in three meerkats (Suricata suricatta).

    PubMed

    Sladky, K K; Dalldorf, F G; Steinberg, H; Wright, J F; Loomis, M R

    2000-11-01

    Cholesterol granulomas are uncommon pathologic lesions in animals, although they are important intracranial tumors in humans. This report describes cholesterol granulomas associated with multiple organ systems of three captive meerkats. In the most severe case, meerkat No. 1, the pathologic behavior of the cholesterol granuloma was unique in that it appeared to locally invade the cerebrum and calvarium, possibly contributing to neurological deficits observed antemortem. A review of other meerkat necropsies revealed incidental, asymptomatic cholesterol granulomas in organs of two other individuals, meerkat Nos. 2 and 3. Histologically, all lesions were composed of cholesterol clefts admixed with large, foamy macrophages containing hemosiderin, multinucleated giant cells, lymphocytes, plasma cells, and foci of mineralization. Hypercholesterolemia was documented in two of the three meerkats. PMID:11105964

  17. Parallel rendering techniques for massively parallel visualization

    SciTech Connect

    Hansen, C.; Krogh, M.; Painter, J.

    1995-07-01

    As the resolution of simulation models increases, scientific visualization algorithms which take advantage of the large memory. and parallelism of Massively Parallel Processors (MPPs) are becoming increasingly important. For large applications rendering on the MPP tends to be preferable to rendering on a graphics workstation due to the MPP`s abundant resources: memory, disk, and numerous processors. The challenge becomes developing algorithms that can exploit these resources while minimizing overhead, typically communication costs. This paper will describe recent efforts in parallel rendering for polygonal primitives as well as parallel volumetric techniques. This paper presents rendering algorithms, developed for massively parallel processors (MPPs), for polygonal, spheres, and volumetric data. The polygon algorithm uses a data parallel approach whereas the sphere and volume render use a MIMD approach. Implementations for these algorithms are presented for the Thinking Ma.chines Corporation CM-5 MPP.

  18. Plant Vascular Biology 2013: vascular trafficking.

    PubMed

    Ursache, Robertas; Heo, Jung-Ok; Helariutta, Ykä

    2014-04-01

    About 200 researchers from around the world attended the Third International Conference on Plant Vascular Biology (PVB 2013) held in July 2013 at the Rantapuisto Conference Center, in Helsinki, Finland (http://www.pvb2013.org). The plant vascular system, which connects every organ in the mature plant, continues to attract the interest of researchers representing a wide range of disciplines, including development, physiology, systems biology, and computational biology. At the meeting, participants discussed the latest research advances in vascular development, long- and short-distance vascular transport and long-distance signalling in plant defence, in addition to providing a context for how these studies intersect with each other. The meeting provided an opportunity for researchers working across a broad range of fields to share ideas and to discuss future directions in the expanding field of vascular biology. In this report, the latest advances in understanding the mechanism of vascular trafficking presented at the meeting have been summarized.

  19. Glycobiology of leukocyte trafficking in inflammation.

    PubMed

    Wright, Rachael D; Cooper, Dianne

    2014-12-01

    To fulfill their potential, leukocytes must be able to exit the vasculature and reach the site of inflammation within the tissue. This process of leukocyte extravasation is a tightly regulated sequence of events that is governed by a host of cell adhesion molecules, cytokines, chemokines and lipid mediators. Of major importance to this process and the function of many of the proteins and lipids involved is the posttranslational modification of these moieties by glycosylation. The glycosylation process is coordinated by multiple enzymes that add and remove saccharides to/from glycan structures on proteins and lipids, resulting in a unique molecular signature that affords specificity to the molecules involved in leukocyte recruitment. This review will discuss how glycosylation impacts the function of these key molecules involved in the recruitment of leukocytes during inflammation and the function of specific lectins (carbohydrate-binding proteins) that have a role in leukocyte trafficking.

  20. Transnational criminal organizations and drug trafficking.

    PubMed

    Williams, P; Florez, C

    1994-01-01

    Transnational criminal organizations, particularly drug-trafficking organizations, operate unrestricted across international borders. They are very similar in kind to legitimate transnational corporations in structure, strength, size, geographical range and scope of their operations. Above all other features they engage in unregulated forms of capitalist enterprise. To fully understand transnational criminal organizations it is necessary to examine them as organizations responding to economic opportunities and focus on the factors that influence their emergence. Those factors can be understood as a result of the confluence of opportunities, pressures, incentives and resources at the global and national level. The present article identifies the key environmental factors relevant to the emergence of transnational criminal organizations, and explores the intrinsic relationship between those organizations, their home States and host States. It is those conditions which not only give rise to transnational criminal organizations, but also help to sustain them.

  1. Endocytic pathways and endosomal trafficking: a primer.

    PubMed

    Elkin, Sarah R; Lakoduk, Ashley M; Schmid, Sandra L

    2016-05-01

    This brief overview of endocytic trafficking is written in honor of Renate Fuchs, who retires this year. In the mid-1980s, Renate pioneered studies on the ion-conducting properties of the recently discovered early and late endosomes and the mechanisms governing endosomal acidification. As described in this review, after uptake through one of many mechanistically distinct endocytic pathways, internalized proteins merge into a common early/sorting endosome. From there they again diverge along distinct sorting pathways, back to the cell surface, on to the trans-Golgi network or across polarized cells. Other transmembrane receptors are packaged into intraluminal vesicles of late endosomes/multivesicular bodies that eventually fuse with and deliver their content to lysosomes for degradation. Endosomal acidification, in part, determines sorting along this pathway. We describe other sorting machinery and mechanisms, as well as the rab proteins and phosphatidylinositol lipids that serve to dynamically define membrane compartments along the endocytic pathway. PMID:26861668

  2. Chinese narcotics trafficking: a preliminary report.

    PubMed

    Huang, Kaicheng; Liu, Jianhong; Zhao, Ruohui; Zhao, Guoling; Friday, Paul C

    2012-02-01

    Questions of existence of the "China Route" for drug smuggling and trafficking have been important in the literature. The profile of the offenders, particularly whether they are primarily members of traditional criminal organization, is a hotly debated issue. Much qualitative evidence has been collected and it provides important insights into these questions. However, little quantitative data has ever been collected and analyzed to provide a broader picture of these issues. The present study involves the systematical collection of data from court sentencing files from seven high courts whose jurisdictions cover the China Route. The findings provide valuable information that sheds light on the debated questions. Some evidence consistent with the China Route arguments is found. No evidence supports the idea that traditional organized criminal syndicates are behind most offenses. Logistic regression results reveal interesting associations between offender characteristics and types of offenses.

  3. Superresolution imaging of viral protein trafficking

    PubMed Central

    Salka, Kyle; Bhuvanendran, Shivaprasad; Yang, David

    2015-01-01

    The endoplasmic reticulum (ER) membrane is closely apposed to the outer mitochondrial membrane (OMM), which facilitates communication between these organelles. These contacts, known as mitochondria-associated membranes (MAM), facilitate calcium signaling, lipid transfer, as well as antiviral and stress responses. How cellular proteins traffic to the MAM, are distributed therein, and interact with ER and mitochondrial proteins are subject of great interest. The human cytomegalovirus UL37 exon 1 protein or viral mitochondria-localized inhibitor of apoptosis (vMIA) is crucial for viral growth. Upon synthesis at the ER, vMIA traffics to the MAM and OMM, where it reprograms the organization and function of these compartments. vMIA significantly changes the abundance of cellular proteins at the MAM and OMM, including proteins that regulate calcium homeostasis and cell death. Through the use of superresolution imaging, we have shown that vMIA is distributed at the OMM in nanometer scale clusters. This is similar to the clusters reported for the mitochondrial calcium channel, VDAC, as well as electron transport chain, translocase of the OMM complex, and mitochondrial inner membrane organizing system components. Thus, aside from addressing how vMIA targets the MAM and regulates survival of infected cells, biochemical studies and superresolution imaging of vMIA offer insights into the formation, organization, and functioning of MAM. Here, we discuss these insights into trafficking, function, and organization of vMIA at the MAM and OMM and discuss how the use of superresolution imaging is contributing to the study of the formation and trafficking of viruses. PMID:25724304

  4. Ubiquitination of CXCR7 Controls Receptor Trafficking

    PubMed Central

    de Munnik, Sabrina; Han, Mitchell K. L.; Smit, Martine J.; Leurs, Rob

    2012-01-01

    The chemokine receptor CXCR7 binds CXCL11 and CXCL12 with high affinity, chemokines that were previously thought to bind exclusively to CXCR4 and CXCR3, respectively. Expression of CXCR7 has been associated with cardiac development as well as with tumor growth and progression. Despite having all the canonical features of G protein-coupled receptors (GPCRs), the signalling pathways following CXCR7 activation remain controversial, since unlike typical chemokine receptors, CXCR7 fails to activate Gαi-proteins. CXCR7 has recently been shown to interact with β-arrestins and such interaction has been suggested to be responsible for G protein-independent signals through ERK-1/2 phosphorylation. Signal transduction by CXCR7 is controlled at the membrane by the process of GPCR trafficking. In the present study we investigated the regulatory processes triggered by CXCR7 activation as well as the molecular interactions that participate in such processes. We show that, CXCR7 internalizes and recycles back to the cell surface after agonist exposure, and that internalization is not only β-arrestin-mediated but also dependent on the Serine/Threonine residues at the C-terminus of the receptor. Furthermore we describe, for the first time, the constitutive ubiquitination of CXCR7. Such ubiquitination is a key modification responsible for the correct trafficking of CXCR7 from and to the plasma membrane. Moreover, we found that CXCR7 is reversibly de-ubiquitinated upon treatment with CXCL12. Finally, we have also identified the Lysine residues at the C-terminus of CXCR7 to be essential for receptor cell surface delivery. Together these data demonstrate the differential regulation of CXCR7 compared to the related CXCR3 and CXCR4 receptors, and highlight the importance of understanding the molecular determinants responsible for this process. PMID:22457824

  5. Ligand-directed trafficking of receptor stimulus.

    PubMed

    Chilmonczyk, Zdzisław; Bojarski, Andrzej J; Sylte, Ingebrigt

    2014-12-01

    GPCRs are seven transmembrane-spanning receptors that convey specific extracellular stimuli to intracellular signalling. They represent the largest family of cell surface proteins that are therapeutically targeted. According to the traditional two-state model of receptor theory, GPCRs were considered as operating in equilibrium between two functional conformations, an active (R*) and inactive (R) state. Thus, it was assumed that a GPCR can exist either in an "off" or "on" conformation causing either no activation or equal activation of all its signalling pathways. Over the past several years it has become evident that this model is too simple and that GPCR signalling is far more complex. Different studies have presented a multistate model of receptor activation in which ligand-specific receptor conformations are able to differentiate between distinct signalling partners. Recent data show that beside G proteins numerous other proteins, such as β-arrestins and kinases, may interact with GPCRs and activate intracellular signalling pathways. GPCR activation may therefore involve receptor desensitization, coupling to multiple G proteins, Gα or Gβγ signalling, and pathway activation that is independent of G proteins. This latter effect leads to agonist "functional selectivity" (also called ligand-directed receptor trafficking, stimulus trafficking, biased agonism, biased signalling), and agonist intervention with functional selectivity may improve the therapy. Many commercially available drugs with beneficial efficacy also show various undesirable side effects. Further studies of biased signalling might facilitate our understanding of the side effects of current drugs and take us to new avenues to efficiently design pathway-specific medications.

  6. Human Trafficking of Children in the United States: A Fact Sheet for Schools

    ERIC Educational Resources Information Center

    Office of Safe and Healthy Students, US Department of Education, 2013

    2013-01-01

    Human trafficking is a serious federal crime with penalties of up to imprisonment for life. Federal law defines "severe forms of trafficking in persons." In short, human trafficking is a form of modern slavery. Those who recruit minors into commercial sexual exploitation (or prostitution) violate federal anti-trafficking laws, even if there is no…

  7. Human Trafficking of Children in the United States: A Fact Sheet

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    This fact sheet presents questions and answers related to the human trafficking of children in the United States. It describes human trafficking and its extent in the United States, how human traffickers target children for coerced labor and sex exploitation, how to identify victims of human trafficking, how to report a suspected incidence of…

  8. Physiological and pathological implications of cholesterol.

    PubMed

    Cortes, Victor A; Busso, Dolores; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2014-01-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signaling and endocrine requirements of animal systems. At a cellular level, cholesterol is found in membranes, where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signaling functions. At an organismal level, cholesterol is the precursor for all steroid hormones, including gluco- and mineralo-corticoids, sex hormones and vitamin D, all of which regulate carbohydrate, sodium, reproductive and bone homeostasis, respectively. This sterol is also the precursor for bile acids, which are important for intestinal absorption of dietary lipids as well as energy and glucose metabolic regulation. Importantly, complex mechanisms maintain cholesterol within physiological ranges and the disregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these diseases has been demonstrated by diverse genetic and pharmacologic animal models that are commented in this review. PMID:24389193

  9. Cholesterol Asymmetry in Synaptic Plasma Membranes

    PubMed Central

    Wood, W. Gibson; Igbavboa, Urule; Müller, Walter E.; Eckert, Gunter P.

    2010-01-01

    Lipids are essential for the structural and functional integrity of membranes. Membrane lipids are not randomly distributed but are localized in different domains. A common characteristic of these membrane domains is their association with cholesterol. Lipid rafts and caveolae are examples of cholesterol enriched domains, which have attracted keen interest. However, two other important cholesterol domains are the exofacial and cytofacial leaflets of the plasma membrane. The two leaflets that make up the bilayer differ in their fluidity, electrical charge, lipid distribution, and active sites of certain proteins. The synaptic plasma membrane (SPM) cytofacial leaflet contains over 85% of the total SPM cholesterol as compared with the exofacial leaflet. This asymmetric distribution of cholesterol is not fixed or immobile but can be modified by different conditions in vivo: 1) chronic ethanol consumption; 2) statins; 3) aging; and 4) apoE isoform. Several potential candidates have been proposed as mechanisms involved in regulation of SPM cholesterol asymmetry: apoE, low-density-lipoprotein receptor, sterol carrier protein-2, fatty acid binding proteins, polyunsaturated fatty acids, p-glycoprotein and caveolin-1. This review examines cholesterol asymmetry in SPM, potential mechanisms of regulation and impact on membrane structure and function. PMID:21214553

  10. Perturbed cholesterol homeostasis in aging spinal cord.

    PubMed

    Parkinson, Gemma M; Dayas, Christopher V; Smith, Doug W

    2016-09-01

    The spinal cord is vital for the processing of sensorimotor information and for its propagation to and from both the brain and the periphery. Spinal cord function is affected by aging, however, the mechanisms involved are not well-understood. To characterize molecular mechanisms of spinal cord aging, microarray analyses of gene expression were performed on cervical spinal cords of aging rats. Of the metabolic and signaling pathways affected, cholesterol-associated pathways were the most comprehensively altered, including significant downregulation of cholesterol synthesis-related genes and upregulation of cholesterol transport and metabolism genes. Paradoxically, a significant increase in total cholesterol content was observed-likely associated with cholesterol ester accumulation. To investigate potential mechanisms for the perturbed cholesterol homeostasis, we quantified the expression of myelin and neuroinflammation-associated genes and proteins. Although there was minimal change in myelin-related expression, there was an increase in phagocytic microglial and astrogliosis markers, particularly in the white matter. Together, these results suggest that perturbed cholesterol homeostasis, possibly as a result of increased inflammatory activation in spinal cord white matter, may contribute to impaired spinal cord function with aging.

  11. Tau pathology induces intraneuronal cholesterol accumulation.

    PubMed

    Glöckner, Frauke; Ohm, Thomas G

    2014-09-01

    Epidemiologic and experimental data suggest the involvement of cholesterol metabolism in the development and progression of Alzheimer disease and Niemann-Pick type C disease, but not of frontotemporal dementias. In these 3 neurodegenerative diseases, however, protein tau hyperphosphorylation and aggregation into neurofibrillary tangles are observed. To elucidate the relationship between cholesterol and tau, we compared sterol levels of neurons burdened with neurofibrillary tangles with those of their unaffected neighbors using semiquantitative filipin fluorescence microscopy in mice expressing P301L mutant human tau (a well-described model of FTDP-17) and in P301L transgenic mice lacking apolipoprotein E (the major cholesterol transporter in the brain). Cellular unesterified cholesterol was higher in neurons affected by tau pathology irrespective of apolipoprotein E deficiency. This argues for an impact of tau pathology on cellular cholesterol homeostasis. We suggest that there is a bidirectional mode of action: Disturbances in cellular cholesterol metabolism may promote tau pathology, but tau pathology may also alter neuronal cholesterol homeostasis; once it is established, a vicious cycle may promote neurofibrillary tangle formation.

  12. Protein kinase activators alter glial cholesterol esterification

    SciTech Connect

    Jeng, I.; Dills, C.; Klemm, N.; Wu, C.

    1986-05-01

    Similar to nonneural tissues, the activity of glial acyl-CoA cholesterol acyltransferase is controlled by a phosphorylation and dephosphorylation mechanism. Manipulation of cyclic AMP content did not alter the cellular cholesterol esterification, suggesting that cyclic AMP is not a bioregulator in this case. Therefore, the authors tested the effect of phorbol-12-myristate 13-acetate (PMA) on cellular cholesterol esterification to determine the involvement of protein kinase C. PMA has a potent effect on cellular cholesterol esterification. PMA depresses cholesterol esterification initially, but cells recover from inhibition and the result was higher cholesterol esterification, suggesting dual effects of protein kinase C. Studies of other phorbol analogues and other protein kinase C activators such as merezein indicate the involvement of protein kinase C. Oleoyl-acetyl glycerol duplicates the effect of PMA. This observation is consistent with a diacyl-glycerol-protein kinase-dependent reaction. Calcium ionophore A23187 was ineffective in promoting the effect of PMA. They concluded that a calcium-independent and protein C-dependent pathway regulated glial cholesterol esterification.

  13. Physiological and pathological implications of cholesterol.

    PubMed

    Cortes, Victor A; Busso, Dolores; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2014-01-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signaling and endocrine requirements of animal systems. At a cellular level, cholesterol is found in membranes, where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signaling functions. At an organismal level, cholesterol is the precursor for all steroid hormones, including gluco- and mineralo-corticoids, sex hormones and vitamin D, all of which regulate carbohydrate, sodium, reproductive and bone homeostasis, respectively. This sterol is also the precursor for bile acids, which are important for intestinal absorption of dietary lipids as well as energy and glucose metabolic regulation. Importantly, complex mechanisms maintain cholesterol within physiological ranges and the disregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these diseases has been demonstrated by diverse genetic and pharmacologic animal models that are commented in this review.

  14. Cholesterol-sensitive Modulation of Transcytosis

    PubMed Central

    Leyt, Julieta; Melamed-Book, Naomi; Vaerman, Jean-Pierre; Cohen, Shulamit; Weiss, Aryeh M.

    2007-01-01

    Cholesterol-rich membrane domains (e.g., lipid rafts) are thought to act as molecular sorting machines, capable of coordinating the organization of signal transduction pathways within limited regions of the plasma membrane and organelles. The significance of these domains in polarized postendocytic sorting is currently not understood. We show that dimeric IgA stimulates the incorporation of its receptor into cholesterol-sensitive detergent-resistant membranes confined to the basolateral surface/basolateral endosomes. A fraction of human transferrin receptor was also found in basolateral detergent-resistant membranes. Disrupting these membrane domains by cholesterol depletion (using methyl-β-cyclodextrin) before ligand-receptor internalization caused depolarization of traffic from endosomes, suggesting that cholesterol in basolateral lipid rafts plays a role in polarized sorting after endocytosis. In contrast, cholesterol depletion performed after ligand internalization stimulated cargo transcytosis. It also stimulated caveolin-1 phosphorylation on tyrosine 14 and the appearance of the activated protein in dimeric IgA-containing apical organelles. We propose that cholesterol depletion stimulates the coupling of transcytotic and caveolin-1 signaling pathways, consequently prompting the membranes to shuttle from endosomes to the plasma membrane. This process may represent a unique compensatory mechanism required to maintain cholesterol balance on the cell surface of polarized epithelia. PMID:17392516

  15. Perturbed cholesterol homeostasis in aging spinal cord.

    PubMed

    Parkinson, Gemma M; Dayas, Christopher V; Smith, Doug W

    2016-09-01

    The spinal cord is vital for the processing of sensorimotor information and for its propagation to and from both the brain and the periphery. Spinal cord function is affected by aging, however, the mechanisms involved are not well-understood. To characterize molecular mechanisms of spinal cord aging, microarray analyses of gene expression were performed on cervical spinal cords of aging rats. Of the metabolic and signaling pathways affected, cholesterol-associated pathways were the most comprehensively altered, including significant downregulation of cholesterol synthesis-related genes and upregulation of cholesterol transport and metabolism genes. Paradoxically, a significant increase in total cholesterol content was observed-likely associated with cholesterol ester accumulation. To investigate potential mechanisms for the perturbed cholesterol homeostasis, we quantified the expression of myelin and neuroinflammation-associated genes and proteins. Although there was minimal change in myelin-related expression, there was an increase in phagocytic microglial and astrogliosis markers, particularly in the white matter. Together, these results suggest that perturbed cholesterol homeostasis, possibly as a result of increased inflammatory activation in spinal cord white matter, may contribute to impaired spinal cord function with aging. PMID:27459933

  16. Cholesterol content in European bovine milk fats.

    PubMed

    Precht, D

    2001-02-01

    Data about the cholesterol content in edible fats like bovine milk fat are important for balancing the cholesterol intake with food. A comparison of 3 different cholesterol determination methods showed that with the direct analysis by a 25 m long TAP steel capillary column the same results could be obtained as with a time-consuming saponification standard method including thin-layer chromatographic cleaning and subsequent silylation. On the other hand with a rapid direct method using a short packed column 21% unsaponifiables as e.g. minor sterols or hydrocarbons could be found in the "cholesterol peak". The analysis of 1142 German milk fats led to a mean cholesterol content of 265.6 +/- 20.0 mg/100 g fat (range: 204.4 to 382.5). For 165 milk fats from other 12 EU-countries, a similar mean cholesterol content of 258.5 +/- 19.9 mg/100 g fat (range: 215.0 to 331.6) was detected. Compared with sufficiently fed cows, underfed cows demonstrated an approx. 10.1% lower mean cholesterol content (238.7 +/- 9.7 mg/100 g fat). On the other hand, during the first 7 days post partum, the colostrum showed a significantly higher mean cholesterol content of 327.2 +/- 99.0 mg/100 g fat (n = 15; range: 213.1 to 583.9). Further, with special conditions as feeding of rape-seed the cholesterol content can be significantly lowered by 8-13%. An extraordinary lowering up to 50% can be reached by dry fractionation of milk fat (stearin "hard" fraction).

  17. Tissue storage and control of cholesterol metabolism in man on high cholesterol diets.

    PubMed

    Quintão, E C; Brumer, S; Stechhahn, K

    1977-03-01

    The possibility of accumulation of tissue cholesterol in human beings submitted to high cholesterol feeding was investigated in liver biopsies and through fecal sterol balance studies. Feeding to 10 individuals 3.1 to 3.4 g/day of cholesterol for 3 weeks raised the mean serum level from 293 to 349 mg/100 ml, namely 19%, whereas the liver cholesterol content was 417 mg/100 g of wet weight. In 10 control cases eating 0.1--0.4 g/day of cholesterol serum cholesterol remained stable throughout the experimental period and the liver cholesterol content was 256 mg/100 g. Difference of liver colesterol level between the two groups was 62%. In 7 patients submitted to two periods of balance investigation on a cholesterol-free synthetic formula diet respectively prior to (PI) and after (PIII) eating the high cholesterol solid food from 4 to 15 weeks (PII), fecal steroid excretion in PIII exceeded PI in 3 patients. Such data are a direct evidence for the existence of an efficient system to release acutely stored cholesterol. In one patient bile acid excretion accounted for the difference between PIII and PI. PMID:849375

  18. Tissue storage and control of cholesterol metabolism in man on high cholesterol diets.

    PubMed

    Quintão, E C; Brumer, S; Stechhahn, K

    1977-03-01

    The possibility of accumulation of tissue cholesterol in human beings submitted to high cholesterol feeding was investigated in liver biopsies and through fecal sterol balance studies. Feeding to 10 individuals 3.1 to 3.4 g/day of cholesterol for 3 weeks raised the mean serum level from 293 to 349 mg/100 ml, namely 19%, whereas the liver cholesterol content was 417 mg/100 g of wet weight. In 10 control cases eating 0.1--0.4 g/day of cholesterol serum cholesterol remained stable throughout the experimental period and the liver cholesterol content was 256 mg/100 g. Difference of liver colesterol level between the two groups was 62%. In 7 patients submitted to two periods of balance investigation on a cholesterol-free synthetic formula diet respectively prior to (PI) and after (PIII) eating the high cholesterol solid food from 4 to 15 weeks (PII), fecal steroid excretion in PIII exceeded PI in 3 patients. Such data are a direct evidence for the existence of an efficient system to release acutely stored cholesterol. In one patient bile acid excretion accounted for the difference between PIII and PI.

  19. Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

    PubMed Central

    Mandal, Pritam; Noutsi, Pakiza; Chaieb, Sahraoui

    2016-01-01

    Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low. PMID:27245215

  20. Cholesterol homeostasis in cardiovascular disease and recent advances in measuring cholesterol signatures.

    PubMed

    Seo, Hong Seog; Choi, Man Ho

    2015-09-01

    Despite the biochemical importance of cholesterol, its abnormal metabolism has serious cellular consequences that lead to endocrine disorders such as cardiovascular disease (CVD). Nevertheless, the impact of blood cholesterol as a CVD risk factor is still debated, and treatment with cholesterol-lowering drugs remains controversial, particularly in older patients. Although, the prevalence of CVD increases with age, the underlying mechanisms for this phenomenon are not well understood, and metabolic changes have not been confirmed as predisposing factors of atherogenesis. The quantification of circulating biomarkers for cholesterol homeostasis is therefore warranted, and reference values for cholesterol absorption and synthesis should be determined in order to establish CVD risk factors. The traditional lipid profile is often derived rather than directly measured and lacks a universal standard to interpret the results. In contrast, mass spectrometry-based cholesterol profiling can accurately measure free cholesterol as a biologically active component. This approach allows to detect alterations in various metabolic pathways that control cholesterol homeostasis, by quantitative analysis of cholesterol and its precursors/metabolites as well as dietary sterols. An overview of the mechanism of cholesterol homeostasis under different physiological conditions may help to identify predictive biomarkers of concomitant atherosclerosis and conventional CVD risk factors.

  1. Raising HDL cholesterol in women

    PubMed Central

    Eapen, Danny J; Kalra, Girish L; Rifai, Luay; Eapen, Christina A; Merchant, Nadya; Khan, Bobby V

    2010-01-01

    High-density lipoprotein cholesterol (HDL-C) concentration is essential in the determination of coronary heart disease (CHD) risk in women. This is especially true in the postmenopausal state, where lipid profiles and CHD risk mimic that of age-matched men. Thus, interventions designed to reduce CHD risk by raising HDL-C levels may have particular significance during the transition to menopause. This review discusses HDL-C-raising therapies and the role of HDL in the primary prevention of CHD in women. Lifestyle-based interventions such as dietary change, aerobic exercise regimens, and smoking cessation are initial steps that are effective in raising HDL-C, and available data suggest women respond similarly to men with these interventions. When combined with pharmacotherapy, the effects of these lifestyle alterations are further amplified. Though studies demonstrating gender-specific differences in therapy are limited, niacin continues to be the most effective agent in raising HDL-C levels, especially when used in combination with fibrate or statin therapy. Emerging treatments such as HDL mimetic therapy show much promise in further raising HDL-C levels and improving cardiovascular outcomes. PMID:21072287

  2. Genetic therapies to lower cholesterol.

    PubMed

    Khoo, Bernard

    2015-01-01

    This review surveys the state-of-the-art in genetic therapies for familial hypercholesterolaemia (FH), caused most commonly by mutations in the LDL receptor (LDLR) gene. FH manifests as highly elevated low density lipoprotein (LDL) cholesterol levels and consequently accelerated atherosclerosis. Modern pharmacological therapies for FH are insufficiently efficacious to prevent premature cardiovascular disease, can cause significant adverse effects and can be expensive. Genetic therapies for FH have been mooted since the mid 1990s but gene replacement strategies using viral vectors have so far been unsuccessful. Other strategies involve knocking down the expression of Apolipoprotein B100 (APOB100) and the protease PCSK9 which designates LDLR for degradation. The antisense oligonucleotide mipomersen, which knocks down APOB100, is currently marketed (with restrictions) in the USA, but is not approved in Europe due to its adverse effects. To address this problem, we have devised a novel therapeutic concept, APO-skip, which is based on modulation of APOB splicing, and which has the potential to deliver a cost-effective, efficacious and safe therapy for FH.

  3. Lecithin:Cholesterol Acyltransferase Deficiency Protects against Cholesterol-induced Hepatic Endoplasmic Reticulum Stress in Mice*

    PubMed Central

    Hager, Lauren; Li, Lixin; Pun, Henry; Liu, Lu; Hossain, Mohammad A.; Maguire, Graham F.; Naples, Mark; Baker, Chris; Magomedova, Lilia; Tam, Jonathan; Adeli, Khosrow; Cummins, Carolyn L.; Connelly, Philip W.; Ng, Dominic S.

    2012-01-01

    We recently reported that lecithin:cholesterol acyltransferase (LCAT) knock-out mice, particularly in the LDL receptor knock-out background, are hypersensitive to insulin and resistant to high fat diet-induced insulin resistance (IR) and obesity. We demonstrated that chow-fed Ldlr−/−xLcat+/+ mice have elevated hepatic endoplasmic reticulum (ER) stress, which promotes IR, compared with wild-type controls, and this effect is normalized in Ldlr−/−xLcat−/− mice. In the present study, we tested the hypothesis that hepatic ER cholesterol metabolism differentially regulates ER stress using these models. We observed that the Ldlr−/−xLcat+/+ mice accumulate excess hepatic total and ER cholesterol primarily attributed to increased reuptake of biliary cholesterol as we observed reduced biliary cholesterol in conjunction with decreased hepatic Abcg5/g8 mRNA, increased Npc1l1 mRNA, and decreased Hmgr mRNA and nuclear SREBP2 protein. Intestinal NPC1L1 protein was induced. Expression of these genes was reversed in the Ldlr−/−xLcat−/− mice, accounting for the normalization of total and ER cholesterol and ER stress. Upon feeding a 2% high cholesterol diet (HCD), Ldlr−/−xLcat−/− mice accumulated a similar amount of total hepatic cholesterol compared with the Ldlr−/−xLcat+/+ mice, but the hepatic ER cholesterol levels remained low in conjunction with being protected from HCD-induced ER stress and IR. Hepatic ER stress correlates strongly with hepatic ER free cholesterol but poorly with hepatic tissue free cholesterol. The unexpectedly low ER cholesterol seen in HCD-fed Ldlr−/−xLcat−/− mice was attributable to a coordinated marked up-regulation of ACAT2 and suppressed SREBP2 processing. Thus, factors influencing the accumulation of ER cholesterol may be important for the development of hepatic insulin resistance. PMID:22500017

  4. Human trafficking and health: a cross-sectional survey of NHS professionals’ contact with victims of human trafficking

    PubMed Central

    Ross, Claire; Dimitrova, Stoyanka; Howard, Louise M; Dewey, Michael; Zimmerman, Cathy; Oram, Siân

    2015-01-01

    Objectives (1) To estimate the proportion of National Health Service (NHS) professionals who have come into contact with trafficked people and (2) to measure NHS professionals’ knowledge and confidence to respond to human trafficking. Design A cross-sectional survey. Setting Face-to-face mandatory child protection and/or vulnerable adults training sessions at 10 secondary healthcare provider organisations in England, and meetings of the UK College of Emergency Medicine. Participants 782/892 (84.4%) NHS professionals participated, including from emergency medicine, maternity, mental health, paediatrics and other clinical disciplines. Measures Self-completed questionnaire developed by an expert panel. Questionnaire asks about prior training and contact with potential victims of trafficking, perceived and actual human trafficking knowledge, confidence in responding to human trafficking, and interest in future human trafficking training. Results 13% participants reported previous contact with a patient they knew or suspected of having been trafficked; among maternity services professionals this was 20.4%. However, 86.8% (n=679) reported lacking knowledge of what questions to ask to identify potential victims and 78.3% (n=613) reported that they had insufficient training to assist trafficked people. 71% (n=556), 67.5% (n=528) and 53.4% (n=418) lacked confidence in making appropriate referrals for men, women and children, respectively, who had been trafficked. 95.3% (n=746) of respondents were unaware of the scale of human trafficking in the UK, and 76.5% (n=598) were unaware that calling the police could put patients in more danger. Psychometric analysis showed that subscales measuring perceived knowledge, actual knowledge and confidence to respond to human trafficking demonstrated good internal consistency (Cronbach's αs 0.93, 0.63 and 0.64, respectively) and internal correlations. Conclusions NHS professionals working in secondary care are in contact with potential

  5. Acyl-coenzyme A:cholesterol acyltransferases

    PubMed Central

    Chang, Ta-Yuan; Li, Bo-Liang; Chang, Catherine C. Y.; Urano, Yasuomi

    2009-01-01

    The enzymes acyl-coenzyme A (CoA):cholesterol acyltransferases (ACATs) are membrane-bound proteins that utilize long-chain fatty acyl-CoA and cholesterol as substrates to form cholesteryl esters. In mammals, two isoenzymes, ACAT1 and ACAT2, encoded by two different genes, exist. ACATs play important roles in cellular cholesterol homeostasis in various tissues. This chapter summarizes the current knowledge on ACAT-related research in two areas: 1) ACAT genes and proteins and 2) ACAT enzymes as drug targets for atherosclerosis and for Alzheimer's disease. PMID:19141679

  6. MPP parallel forth

    NASA Technical Reports Server (NTRS)

    Dorband, John E.

    1987-01-01

    Massively Parallel Processor (MPP) Parallel FORTH is a derivative of FORTH-83 and Unified Software Systems' Uni-FORTH. The extension of FORTH into the realm of parallel processing on the MPP is described. With few exceptions, Parallel FORTH was made to follow the description of Uni-FORTH as closely as possible. Likewise, the parallel FORTH extensions were designed as philosophically similar to serial FORTH as possible. The MPP hardware characteristics, as viewed by the FORTH programmer, is discussed. Then a description is presented of how parallel FORTH is implemented on the MPP.

  7. Triglycerides, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol in rats exposed to premium motor spirit fumes

    PubMed Central

    Aberare, Ogbevire L.; Okuonghae, Patrick; Mukoro, Nathaniel; Dirisu, John O.; Osazuwa, Favour; Odigie, Elvis; Omoregie, Richard

    2011-01-01

    Background: Deliberate and regular exposure to premium motor spirit fumes is common and could be a risk factor for liver disease in those who are occupationally exposed. A possible association between premium motor spirit fumes and plasma levels of triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol using a rodent model could provide new insights in the pathology of diseases where cellular dysfunction is an established risk factor. Aim: The aim of this study was to evaluate the possible effect of premium motor spirit fumes on lipids and lipoproteins in workers occupationally exposed to premium motor spirit fumes using rodent model. Materials and Methods: Twenty-five Wister albino rats (of both sexes) were used for this study between the 4th of August and 7th of September, 2010. The rats were divided into five groups of five rats each. Group 1 rats were not exposed to premium motor spirit fumes (control group), group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the estimation of plasma levels of triglyceride, total cholesterol, high density lipoprotein- cholesterol and low density lipoprotein- cholesterol. Result: Results showed significant increase in means of plasma total cholesterol and low density lipoprotein levels (P<0.05). The mean triglyceride and total body weight were significantly lower (P<0.05) in the exposed group when compared with the unexposed. The plasma level of high density lipoprotein, the ratio of low density lipoprotein to high density lipoprotein and the ratio of total cholesterol to high density lipoprotein did not differ significantly in exposed subjects when compared with the control group. Conclusion: These results showed that frequent exposure to petrol fumes may be highly

  8. The Medical Response to Sex Trafficking of Minors in Wisconsin.

    PubMed

    Rabbitt, Angela

    2015-04-01

    Medical professionals are in a unique position to identify and assist pediatric victims of sex trafficking, who experience a high prevalence of physical, mental, and sexual health problems. However, providers report a need for education and guidelines for medical care of this population. A literature review was conducted on the nature and scope of pediatric sex trafficking in Wisconsin, the medical and mental health needs of victims, and existing guidelines for medical management. Few existing medical guidelines for the care of trafficking victims are specific to pediatrics or include specific recommendations for the forensic medical evaluation. Because of legislation and resources specific to Wisconsin, national guidelines may not apply locally. Based on the literature review, as well as input from community partners and medical professionals who frequently provide services to victims, guidelines for the medical care of pediatric sex trafficking victims in Wisconsin were developed. Additional community barriers that may prevent an effective medical response also are discussed. PMID:26756057

  9. Recognizing victims of human trafficking in the pediatric emergency department.

    PubMed

    Becker, Heather J; Bechtel, Kirsten

    2015-02-01

    Human trafficking is a form of modern-day slavery that is rapidly expanding in the United States and throughout the world. It is a crime under both the United States and international law. The child and adult victims of human trafficking are denied their basic human rights and subjected to unspeakable physical and emotional harm. Traffickers exert complete control over their victims and are proficient at hiding their condition from authorities. Healthcare practitioners may be the only professionals who come into contact with victims if they present for medical care. This article will describe human trafficking and its potential victims, as well as guide medical management and access to services that will ensure their safety and restore their freedom.

  10. Endocytosis and Intracellular Trafficking of Human Natural Killer Cell Receptors

    PubMed Central

    Masilamani, Madhan; Peruzzi, Giovanna; Borrego, Francisco; Coligan, John E.

    2009-01-01

    Natural killer (NK) cells play a vital role in the defense against viral infections and tumor development. NK cell function is primarily regulated by the sum of signals from a broad array of activation and inhibitory receptors. Key to generating the input level of either activating or inhibitory signals is the maintenance of receptor expression levels on the cell surface. Although the mechanisms of endocytosis and trafficking for some cell surface receptors, such as transferrin receptor, and certain immune receptors, are very well known, that is not the situation for receptors expressed by NK cells. Recent studies have uncovered that endocytosis and trafficking routes characteristic for specific activation and inhibitory receptors can regulate the functional responses of NK cells. In this review, we summarize the current knowledge of receptor endocytosis and trafficking, and integrate this with our current understanding of NK cell receptor trafficking. PMID:19719476

  11. Recognizing victims of human trafficking in the pediatric emergency department.

    PubMed

    Becker, Heather J; Bechtel, Kirsten

    2015-02-01

    Human trafficking is a form of modern-day slavery that is rapidly expanding in the United States and throughout the world. It is a crime under both the United States and international law. The child and adult victims of human trafficking are denied their basic human rights and subjected to unspeakable physical and emotional harm. Traffickers exert complete control over their victims and are proficient at hiding their condition from authorities. Healthcare practitioners may be the only professionals who come into contact with victims if they present for medical care. This article will describe human trafficking and its potential victims, as well as guide medical management and access to services that will ensure their safety and restore their freedom. PMID:25651385

  12. δ-Tocopherol reduces lipid accumulation in Niemann-Pick type C1 and Wolman cholesterol storage disorders.

    PubMed

    Xu, Miao; Liu, Ke; Swaroop, Manju; Porter, Forbes D; Sidhu, Rohini; Firnkes, Sally; Finkes, Sally; Ory, Daniel S; Marugan, Juan J; Xiao, Jingbo; Southall, Noel; Pavan, William J; Davidson, Cristin; Walkley, Steven U; Remaley, Alan T; Baxa, Ulrich; Sun, Wei; McKew, John C; Austin, Christopher P; Zheng, Wei

    2012-11-16

    Niemann-Pick disease type C (NPC) and Wolman disease are two members of a family of storage disorders caused by mutations of genes encoding lysosomal proteins. Deficiency in function of either the NPC1 or NPC2 protein in NPC disease or lysosomal acid lipase in Wolman disease results in defective cellular cholesterol trafficking. Lysosomal accumulation of cholesterol and enlarged lysosomes are shared phenotypic characteristics of both NPC and Wolman cells. Utilizing a phenotypic screen of an approved drug collection, we found that δ-tocopherol effectively reduced lysosomal cholesterol accumulation, decreased lysosomal volume, increased cholesterol efflux, and alleviated pathological phenotypes in both NPC1 and Wolman fibroblasts. Reduction of these abnormalities may be mediated by a δ-tocopherol-induced intracellular Ca(2+) response and subsequent enhancement of lysosomal exocytosis. Consistent with a general mechanism for reduction of lysosomal lipid accumulation, we also found that δ-tocopherol reduces pathological phenotypes in patient fibroblasts from other lysosomal storage diseases, including NPC2, Batten (ceroid lipofuscinosis, neuronal 2, CLN2), Fabry, Farber, Niemann-Pick disease type A, Sanfilippo type B (mucopolysaccharidosis type IIIB, MPSIIIB), and Tay-Sachs. Our data suggest that regulated exocytosis may represent a potential therapeutic target for reduction of lysosomal storage in this class of diseases. PMID:23035117

  13. Three-dimensional imaging of nucleolin trafficking in normal cells, transfectants, and heterokaryons

    NASA Astrophysics Data System (ADS)

    Ballou, Byron T.; Fisher, Gregory W.; Deng, Jau-Shyong; Hakala, Thomas R.; Srivastava, Meera; Farkas, Daniel L.

    1996-04-01

    The study of intracellular trafficking using labeled molecules has been aided by the development of the cyanine fluorochromes, which are easily coupled, very soluble, resist photobleaching, and fluoresce at far-red wavelengths where background fluorescence is minimal. We have used Cy3-, Cy5-, and Cy5.5-labeled antibodies, antigen-binding fragments, and specifically binding single-stranded oligonucleotides to follow expression and trafficking of nucleolin, the most abundant protein of the nucleolus. Nucleolin shuttles between the nucleolus and the cytoplasm, and is also expressed on the cell surface, allowing us to test our techniques at all three cellular sites. Differentially cyanine-labeled non-specific antibodies were used to control for non-specific binding. Similarly, the differentially labeled non-binding strand of the cloned oligonucleotide served as a control. The multimode microscope allowed us to follow both rapid and slow redistributions of labeled ligands in the same study. We also performed 3-D reconstructions of nucleolin distribution in cells using rapid acquisition and deconvolution. Microinjection of labeled ligands was used to follow intracellular distribution, while incubation of whole cells with antibody and antigen-binding fragments was used to study uptake. To unambiguously define trafficking, and eliminate the possibility of interference by cross-reactive proteins, we transfected mouse renal cell carcinoma cells that express cell surface nucleolin with human nucleolin. We used microinjection and cell surface staining with Cy3- or Cy5- labeled monoclonal antibody D3 (specific for human nucleolin) to assess the cellular distribution of the human protein. Several clones expressed human nucleolin on their surfaces and showed high levels of transport of the human protein into the mouse nucleus and nucleolus. This distribution roughly parallels that of mouse nucleolin as determined by labeled polyclonal antibody. We have used these engineered

  14. Differential subcellular localization of cholesterol, gangliosides, and glycosaminoglycans in murine models of mucopolysaccharide storage disorders.

    PubMed

    McGlynn, Robert; Dobrenis, Kostantin; Walkley, Steven U

    2004-12-20

    The mucopolysaccharidoses (MPSs) are a complex family of lysosomal storage disorders characterized by failure to degrade heparan sulfate (HS) and/or other types of glycosaminoglycans (GAGs) secondary to the absence of specific lysosomal enzymes. An accompanying storage of glycosphingolipids (GSLs), most notably GM2 and GM3 gangliosides, has also been documented to occur in many types of MPS disease and is believed to be caused by secondary inhibition of GSL-degradative enzymes by intracellular GAG accumulation. We have documented the presence of secondary ganglioside accumulation in mouse models of several MPS disorders (types I, IIIA, IIIB, and VII) and report that this storage is accompanied by sequestration of free cholesterol in a manner similar to that observed in primary gangliosidoses. Using confocal microscopy, we evaluated the cellular distribution of cholesterol, GM2 and GM3 gangliosides, and HS in brains of mice with MPS IIIA disease. Unexpectedly, we found that although both gangliosides often accumulated in the same neurons, they were consistently located in separate populations of cytoplasmic vesicles. Additionally, GM3 ganglioside only partially co-localized with the primary storage material (HS), and cholesterol likewise only partially co-localized with the GM2 and GM3 gangliosides. These findings raise significant questions about the mechanism(s) responsible for secondary accumulation of storage materials in MPS disease. Furthermore, given that GSLs and cholesterol are constituents of membrane rafts believed critical in signal transduction events in neurons, their co-sequestration in individual neurons suggests the presence of defects in the composition, trafficking, and/or recycling of raft components and thus possible new mechanisms to explain neuronal dysfunction in MPS disorders.

  15. Drug Trafficking Organizations and Local Economic Activity in Mexico.

    PubMed

    González, Felipe

    2015-01-01

    Little is known about the relationship between illegal firms and local economic activity. In this paper I study changes in satellite night lights across Mexican municipalities after the arrival of large drug trafficking organizations in the period 2000-2010. After accounting for state trends and differences in political regimes, results indicate no significant change in night lights after the arrival of these illegal firms. Estimated coefficients are precise, robust, and similar across different drug trafficking organizations.

  16. Drug Trafficking Organizations and Local Economic Activity in Mexico.

    PubMed

    González, Felipe

    2015-01-01

    Little is known about the relationship between illegal firms and local economic activity. In this paper I study changes in satellite night lights across Mexican municipalities after the arrival of large drug trafficking organizations in the period 2000-2010. After accounting for state trends and differences in political regimes, results indicate no significant change in night lights after the arrival of these illegal firms. Estimated coefficients are precise, robust, and similar across different drug trafficking organizations. PMID:26348041

  17. Drug Trafficking Organizations and Local Economic Activity in Mexico

    PubMed Central

    González, Felipe

    2015-01-01

    Little is known about the relationship between illegal firms and local economic activity. In this paper I study changes in satellite night lights across Mexican municipalities after the arrival of large drug trafficking organizations in the period 2000–2010. After accounting for state trends and differences in political regimes, results indicate no significant change in night lights after the arrival of these illegal firms. Estimated coefficients are precise, robust, and similar across different drug trafficking organizations. PMID:26348041

  18. Sex trafficking of minors in metropolitan, micropolitan, and rural communities.

    PubMed

    Cole, Jennifer; Sprang, Ginny

    2015-02-01

    The purpose of the study was to examine professionals' awareness, knowledge, and experiences working with youth victims of sex trafficking in metropolitan and non-metropolitan communities. Professionals who worked with at-risk youth and/or crime victims were recruited from all counties in a southern, rural state in the U.S. to complete a telephone survey. Surveys included closed and open-ended questions, which were theme coded. Professionals' (n=289) were classified into one of four categories based on the counties in which they worked: metropolitan, micropolitan, rural, and all three community types. Although there were many similarities found in trafficking situations across the different types of communities, some expected differences were found. First, as expected, more professionals in metropolitan communities perceived CSEC as being a fairly or very serious problem in the state overall. Consistent with other studies, more professionals in metropolitan communities had received training on human trafficking and reported they were familiar with the state and federal laws on human trafficking (Newton et al., 2008). Significantly more professionals in metropolitan (54.7%) communities reported they had worked with a suspected or definite victim of STM compared to professionals in micropolitan communities (29.8%). There were few differences in victim characteristics, vulnerability factors, and trafficking situations (e.g., relationship to trafficker, traffickers' techniques for controlling victims, transportation, and Internet-facilitation of trafficking) across the community types. There is a continued need for awareness building of STM and training, particularly in non-metropolitan communities, as well as adoption of screening tools, integration of trauma-informed care, and identification of best practices. PMID:25151302

  19. Sex trafficking of minors in metropolitan, micropolitan, and rural communities.

    PubMed

    Cole, Jennifer; Sprang, Ginny

    2015-02-01

    The purpose of the study was to examine professionals' awareness, knowledge, and experiences working with youth victims of sex trafficking in metropolitan and non-metropolitan communities. Professionals who worked with at-risk youth and/or crime victims were recruited from all counties in a southern, rural state in the U.S. to complete a telephone survey. Surveys included closed and open-ended questions, which were theme coded. Professionals' (n=289) were classified into one of four categories based on the counties in which they worked: metropolitan, micropolitan, rural, and all three community types. Although there were many similarities found in trafficking situations across the different types of communities, some expected differences were found. First, as expected, more professionals in metropolitan communities perceived CSEC as being a fairly or very serious problem in the state overall. Consistent with other studies, more professionals in metropolitan communities had received training on human trafficking and reported they were familiar with the state and federal laws on human trafficking (Newton et al., 2008). Significantly more professionals in metropolitan (54.7%) communities reported they had worked with a suspected or definite victim of STM compared to professionals in micropolitan communities (29.8%). There were few differences in victim characteristics, vulnerability factors, and trafficking situations (e.g., relationship to trafficker, traffickers' techniques for controlling victims, transportation, and Internet-facilitation of trafficking) across the community types. There is a continued need for awareness building of STM and training, particularly in non-metropolitan communities, as well as adoption of screening tools, integration of trauma-informed care, and identification of best practices.

  20. Sterol carrier protein-2 (SCP-2) involvement in cholesterol hydroperoxide cytotoxicity as revealed by SCP-2 inhibitor effects.

    PubMed

    Kriska, Tamas; Pilat, Anna; Schmitt, Jared C; Girotti, Albert W

    2010-11-01

    Sterol carrier protein-2 (SCP-2) plays an important role in cholesterol trafficking and metabolism in mammalian cells. The purpose of this study was to determine whether SCP-2, under oxidative stress conditions, might also traffic hydroperoxides of cholesterol, thereby disseminating their cytotoxic effects. Two inhibitors, SCPI-1 and SCPI-3, known to block cholesterol binding by an insect SCP-2, were used to investigate this. A mouse fibroblast transfectant clone (SC2F) overexpressing SCP-2 was found to be substantially more sensitive to apoptotic killing induced by liposomal 7α-hydroperoxycholesterol (7α-OOH) than a wild-type control. 7α-OOH uptake by SC2F cells and resulting apoptosis were both inhibited by SCPI-1 or SCPI-3 at a subtoxic concentration. Preceding cell death, reactive oxidant accumulation and loss of mitochondrial membrane potential were also strongly inhibited. Similar SCPI protection against 7α-OOH was observed with two other types of SCP-2-expressing mammalian cells. In striking contrast, neither inhibitor had any effect on H(2)O(2)-induced cell killing. To learn whether 7α-OOH cytotoxicity is due to uptake/transport by SCP-2, we used a fluorescence-based competitive binding assay involving recombinant SCP-2, NBD-cholesterol, and SCPI-1/SCPI-3 or 7α-OOH. The results clearly showed that 7α-OOH binds to SCP-2 in SCPI-inhibitable fashion. Our findings suggest that cellular SCP-2 not only binds and translocates cholesterol but also cholesterol hydroperoxides, thus expanding their redox toxicity and signaling ranges under oxidative stress conditions.

  1. New CETP inhibitor K-312 reduces PCSK9 expression: a potential effect on LDL cholesterol metabolism.

    PubMed

    Miyosawa, Katsutoshi; Watanabe, Yuichiro; Murakami, Kentaro; Murakami, Takeshi; Shibata, Haruki; Iwashita, Masaya; Yamazaki, Hiroyuki; Yamazaki, Koichi; Ohgiya, Tadaaki; Shibuya, Kimiyuki; Mizuno, Ken; Tanabe, Sohei; Singh, Sasha A; Aikawa, Masanori

    2015-07-15

    Despite significant reduction of cardiovascular events by statin treatment, substantial residual risk persists, driving emerging needs for the development of new therapies. We identified a novel cholesteryl ester transfer protein (CETP) inhibitor, K-312, that raises HDL and lowers LDL cholesterol levels in animals. K-312 also suppresses hepatocyte expression of proprotein convertase subtilisin/kexin 9 (PCSK9), a molecule that increases LDL cholesterol. We explored the underlying mechanism for the reduction of PCSK9 expression by K-312. K-312 inhibited in vitro human plasma CETP activity (IC50; 0.06 μM). Administration of K-312 to cholesterol-fed New Zealand White rabbits for 18 wk raised HDL cholesterol, decreased LDL cholesterol, and attenuated aortic atherosclerosis. Our search for additional beneficial characteristics of this compound revealed that K-312 decreases PCSK9 expression in human primary hepatocytes and in the human hepatoma cell line HepG2. siRNA silencing of CETP in HepG2 did not compromise the suppression of PCSK9 by K-312, suggesting a mechanism independent of CETP. In HepG2 cells, K-312 treatment decreased the active forms of sterol regulatory element-binding proteins (SREBP-1 and -2) that regulate promoter activity of PCSK9. Chromatin immunoprecipitation assays demonstrated that K-312 decreased the occupancy of SREBP-1 and SREBP-2 on the sterol regulatory element of the PCSK9 promoter. PCSK9 protein levels decreased by K-312 treatment in the circulating blood of cholesterol-fed rabbits, as determined by two independent mass spectrometry approaches, including the recently developed, highly sensitive parallel reaction monitoring method. New CETP inhibitor K-312 decreases LDL cholesterol and PCSK9 levels, serving as a new therapy for dyslipidemia and cardiovascular disease.

  2. Rapid turn-over of plasma membrane sphingomyelin and cholesterol in baby hamster kidney cells after exposure to sphingomyelinase.

    PubMed

    Slotte, J P; Härmälä, A S; Jansson, C; Pörn, M I

    1990-12-14

    Plasma membrane sphingomyelin in baby hamster kidney (BHK-21) cells was hydrolyzed with sphingomyelinase (Staphylococcus aureus) and the effects on membrane cholesterol translocation and the properties of membrane bound adenylate cyclase and Na+/K(+)-ATPase were determined. Exposure of confluent BHK-21 cells to 0.1 U/ml of sphingomyelinase led to the degradation (at 37 degrees C) of about 60% of cell sphingomyelin. No simultaneous hydrolysis of phosphatidylcholine occurred. The hydrolysis of sphingomyelin subsequently led to the translocation (within 40 min) of about 50-60% of cell [3H]cholesterol from a cholesterol oxidase susceptible pool to an oxidase resistant compartment. The translocation of [3H]cholesterol from the cell surface to intracellular membranes was accompanied by a paralleled increase in [3H]cholesterol ester formation. When cells were first exposed to sphingomyelinase (to degrade sphingomyelin) and then incubated without the enzyme in serum-free media, the mass of cell sphingomyelin decreased initially (by 60%), but then began to increase and reached control levels within 3-4 h. The rapid re-synthesis of sphingomyelin was accompanied by an equally rapid normalization of cell [3H]cholesterol distribution. The re-formation of cell sphingomyelin also led to a decreased content of cellular [3H]cholesterol esters, indicating that unesterified [3H]cholesterol was pulled out of the cholesterol ester cycle and transported to the cell surface. Exposure of BHK-21 cells to sphingomyelinase further led to a dramatically decreased activity of ouabain-sensitive Na+/K(+)-ATPase, whereas forskolin-stimulated adenylate cyclase activity was not affected. The activity of Na+/K(+)-ATPase returned to normal in parallel with the normalization of cell sphingomyelin mass and cholesterol distribution. We conclude that sphingomyelin has profound effects on the steady-state distribution of cell cholesterol, and that manipulations of cell sphingomyelin levels directly and

  3. Rapid turn-over of plasma membrane sphingomyelin and cholesterol in baby hamster kidney cells after exposure to sphingomyelinase.

    PubMed

    Slotte, J P; Härmälä, A S; Jansson, C; Pörn, M I

    1990-12-14

    Plasma membrane sphingomyelin in baby hamster kidney (BHK-21) cells was hydrolyzed with sphingomyelinase (Staphylococcus aureus) and the effects on membrane cholesterol translocation and the properties of membrane bound adenylate cyclase and Na+/K(+)-ATPase were determined. Exposure of confluent BHK-21 cells to 0.1 U/ml of sphingomyelinase led to the degradation (at 37 degrees C) of about 60% of cell sphingomyelin. No simultaneous hydrolysis of phosphatidylcholine occurred. The hydrolysis of sphingomyelin subsequently led to the translocation (within 40 min) of about 50-60% of cell [3H]cholesterol from a cholesterol oxidase susceptible pool to an oxidase resistant compartment. The translocation of [3H]cholesterol from the cell surface to intracellular membranes was accompanied by a paralleled increase in [3H]cholesterol ester formation. When cells were first exposed to sphingomyelinase (to degrade sphingomyelin) and then incubated without the enzyme in serum-free media, the mass of cell sphingomyelin decreased initially (by 60%), but then began to increase and reached control levels within 3-4 h. The rapid re-synthesis of sphingomyelin was accompanied by an equally rapid normalization of cell [3H]cholesterol distribution. The re-formation of cell sphingomyelin also led to a decreased content of cellular [3H]cholesterol esters, indicating that unesterified [3H]cholesterol was pulled out of the cholesterol ester cycle and transported to the cell surface. Exposure of BHK-21 cells to sphingomyelinase further led to a dramatically decreased activity of ouabain-sensitive Na+/K(+)-ATPase, whereas forskolin-stimulated adenylate cyclase activity was not affected. The activity of Na+/K(+)-ATPase returned to normal in parallel with the normalization of cell sphingomyelin mass and cholesterol distribution. We conclude that sphingomyelin has profound effects on the steady-state distribution of cell cholesterol, and that manipulations of cell sphingomyelin levels directly and

  4. A fluorescent cholesterol analogue for observation of free cholesterol in the plasma membrane of live cells.

    PubMed

    Ogawa, Yoshikatsu; Tanaka, Mutsuo

    2016-01-01

    Free cholesterol in mammalian cells resides mostly in the plasma membrane, where it plays an important role in cellular homeostasis. We synthesized a new fluorescent cholesterol analogue that retained an intact alkyl chain and the sterane backbone of cholesterol. The hydroxyl group of cholesterol was converted into an amino group that was covalently linked to the fluorophore tetramethylrhodamine to retain the ability to form hydrogen bonds with adjacent molecules. Incubating live MDCK (Madin-Darby canine kidney) cells with our fluorescent cholesterol analogue resulted in the generation of intense signals that were detected by microscopy at the plasma membrane. Incubation with the analogue exerted minimal, if any, influence on cell growth, indicating that it could serve as a useful tool for analyzing free cholesterol at the plasma membrane.

  5. Cellular membrane trafficking of mesoporous silica nanoparticles

    SciTech Connect

    Fang, I-Ju

    2012-01-01

    This dissertation mainly focuses on the investigation of the cellular membrane trafficking of mesoporous silica nanoparticles. We are interested in the study of endocytosis and exocytosis behaviors of mesoporous silica nanoparticles with desired surface functionality. The relationship between mesoporous silica nanoparticles and membrane trafficking of cells, either cancerous cells or normal cells was examined. Since mesoporous silica nanoparticles were applied in many drug delivery cases, the endocytotic efficiency of mesoporous silica nanoparticles needs to be investigated in more details in order to design the cellular drug delivery system in the controlled way. It is well known that cells can engulf some molecules outside of the cells through a receptor-ligand associated endocytosis. We are interested to determine if those biomolecules binding to cell surface receptors can be utilized on mesoporous silica nanoparticle materials to improve the uptake efficiency or govern the mechanism of endocytosis of mesoporous silica nanoparticles. Arginine-glycine-aspartate (RGD) is a small peptide recognized by cell integrin receptors and it was reported that avidin internalization was highly promoted by tumor lectin. Both RGD and avidin were linked to the surface of mesoporous silica nanoparticle materials to investigate the effect of receptor-associated biomolecule on cellular endocytosis efficiency. The effect of ligand types, ligand conformation and ligand density were discussed in Chapter 2 and 3. Furthermore, the exocytosis of mesoporous silica nanoparticles is very attractive for biological applications. The cellular protein sequestration study of mesoporous silica nanoparticles was examined for further information of the intracellular pathway of endocytosed mesoporous silica nanoparticle materials. The surface functionality of mesoporous silica nanoparticle materials demonstrated selectivity among the materials and cancer and normal cell lines. We aimed to determine

  6. [Cholesterol and atherosclerosis. Historical considerations and treatment].

    PubMed

    Zárate, Arturo; Manuel-Apolinar, Leticia; Basurto, Lourdes; De la Chesnaye, Elsa; Saldívar, Iván

    2016-01-01

    Cholesterol is a precursor of steroid hormones and an essential component of the cell membrane, however, altered regulation of the synthesis, absorption and excretion of cholesterol predispose to cardiovascular diseases of atherosclerotic origin. Despite, the recognition of historical events for 200 years, starting with Michel Chevreul naming «cholesterol»; later on, Lobstein coining the term atherosclerosis and Marchand introducing it, Anichkov identifying cholesterol in atheromatous plaque, and Brown and Goldstein discovering LDL receptor; as well as the emerging of different drugs, such as fibrates, statins and cetrapibs this decade, promising to increase HDL and the most recent ezetimibe and anti-PCSK9 to inhibit the degradation of LDL receptor, however morbidity has not been reduced in cardiovascular disease. PMID:26774359

  7. [Cholesterol and atherosclerosis. Historical considerations and treatment].

    PubMed

    Zárate, Arturo; Manuel-Apolinar, Leticia; Basurto, Lourdes; De la Chesnaye, Elsa; Saldívar, Iván

    2016-01-01

    Cholesterol is a precursor of steroid hormones and an essential component of the cell membrane, however, altered regulation of the synthesis, absorption and excretion of cholesterol predispose to cardiovascular diseases of atherosclerotic origin. Despite, the recognition of historical events for 200 years, starting with Michel Chevreul naming «cholesterol»; later on, Lobstein coining the term atherosclerosis and Marchand introducing it, Anichkov identifying cholesterol in atheromatous plaque, and Brown and Goldstein discovering LDL receptor; as well as the emerging of different drugs, such as fibrates, statins and cetrapibs this decade, promising to increase HDL and the most recent ezetimibe and anti-PCSK9 to inhibit the degradation of LDL receptor, however morbidity has not been reduced in cardiovascular disease.

  8. HDL Function, Dysfunction, and Reverse Cholesterol Transport

    PubMed Central

    Fisher, Edward A.; Feig, Jonathan E.; Hewing, Bernd; Hazen, Stanley L.; Smith, Jonathan D.

    2012-01-01

    Although high HDL-cholesterol levels are associated with decreased cardiovascular risk in epidemiological studies, recent genetic and pharmacological findings have raised doubts about the beneficial effects of HDL. Raising HDL levels in animal models by infusion or over expression of apolipoprotein A-I has shown clear vascular improvements, such as delayed atherosclerotic lesion progression and accelerated lesion regression, along with increased reverse cholesterol transport. Inflammation and other factors, such as myeloperoxidase mediated oxidation, can impair HDL production and HDL function, in regard to its reverse cholesterol transport, antioxidant, and anti-inflammatory activities. Thus, tests of HDL function, which have not yet been developed as routine diagnostic assays, may prove useful and be a better predictor of cardiovascular risk than HDL-cholesterol levels. PMID:23152494

  9. Parallel flow diffusion battery

    DOEpatents

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  10. Parallel flow diffusion battery

    DOEpatents

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  11. Serum cholesterol concentration and coronary heart disease in population with low cholesterol concentrations.

    PubMed Central

    Chen, Z; Peto, R; Collins, R; MacMahon, S; Lu, J; Li, W

    1991-01-01

    OBJECTIVE--To examine the relation between serum cholesterol concentration and mortality (from coronary heart disease and from other causes) below the range of cholesterol values generally seen in Western populations. DESIGN--Prospective observational study based on 8-13 years of follow up of subjects in a population with low cholesterol concentrations. SETTING--Urban Shanghai, China. SUBJECTS--9021 Chinese men and women aged 35-64 at baseline. MAIN OUTCOME MEASURE--Death from coronary heart disease and other causes. RESULTS--The average serum cholesterol concentration was 4.2 mmol/l at baseline examination, and only 43 (7%) of the deaths that occurred during 8-13 years of follow up were attributed to coronary heart disease. There was a strongly positive, and apparently independent, relation between serum cholesterol concentration and death from coronary heart disease (z = 3.47, p less than 0.001), and within the range of usual serum cholesterol concentration studied (3.8-4.7 mmol/l) there was no evidence of any threshold. After appropriate adjustment for the regression dilution bias, a 4 (SD 1)% difference in usual cholesterol concentration was associated with a 21 (SD 6)% (95% confidence interval 9% to 35%) difference in mortality from coronary heart disease. There was no significant relation between serum cholesterol concentration and death from stroke or all types of cancer. The 79 deaths due to liver cancer or other chronic liver disease were inversely related to cholesterol concentration at baseline. CONCLUSION--Blood cholesterol concentration was directly related to mortality from coronary heart disease even in those with what was, by Western standards, a "low" cholesterol concentration. There was no good evidence of an adverse effect of cholesterol on other causes of death. PMID:1888927

  12. Analysis of Occludin Trafficking, Demonstrating Continuous Endocytosis, Degradation, Recycling and Biosynthetic Secretory Trafficking

    PubMed Central

    Fletcher, Sarah J.; Iqbal, Mudassar; Jabbari, Sara; Stekel, Dov; Rappoport, Joshua Z.

    2014-01-01

    Tight junctions (TJs) link adjacent cells and are critical for maintenance of apical-basolateral polarity in epithelial monolayers. The TJ protein occludin functions in disparate processes, including wound healing and Hepatitis C Virus infection. Little is known about steady-state occludin trafficking into and out of the plasma membrane. Therefore, we determined the mechanisms responsible for occludin turnover in confluent Madin-Darby canine kidney (MDCK) epithelial monolayers. Using various biotin-based trafficking assays we observed continuous and rapid endocytosis of plasma membrane localised occludin (the majority internalised within 30 minutes). By 120 minutes a significant reduction in internalised occludin was observed. Inhibition of lysosomal function attenuated the reduction in occludin signal post-endocytosis and promoted co-localisation with the late endocytic system. Using a similar method we demonstrated that ∼20% of internalised occludin was transported back to the cell surface. Consistent with these findings, significant co-localisation between internalised occludin and recycling endosomal compartments was observed. We then quantified the extent to which occludin synthesis and transport to the plasma membrane contributes to plasma membrane occludin homeostasis, identifying inhibition of protein synthesis led to decreased plasma membrane localised occludin. Significant co-localisation between occludin and the biosynthetic secretory pathway was demonstrated. Thus, under steady-state conditions occludin undergoes turnover via a continuous cycle of endocytosis, recycling and degradation, with degradation compensated for by biosynthetic exocytic trafficking. We developed a mathematical model to describe the endocytosis, recycling and degradation of occludin, utilising experimental data to provide quantitative estimates for the rates of these processes. PMID:25422932

  13. The retinal pigment epithelium as a gateway for monocyte trafficking into the eye.

    PubMed

    Benhar, Inbal; Reemst, Kitty; Kalchenko, Vyacheslav; Schwartz, Michal

    2016-06-01

    The choroid plexus epithelium within the brain ventricles orchestrates blood-derived monocyte entry to the central nervous system under injurious conditions, including when the primary injury site is remote from the brain. Here, we hypothesized that the retinal pigment epithelium (RPE) serves a parallel role, as a gateway for monocyte trafficking to the retina following direct or remote injury. We found elevated expression of genes encoding leukocyte trafficking determinants in mouse RPE as a consequence of retinal glutamate intoxication or optic nerve crush (ONC). Blocking VCAM-1 after ONC interfered with monocyte infiltration into the retina and resulted in a local pro-inflammatory cytokine bias. Live imaging of the injured eye showed monocyte accumulation first in the RPE, and subsequently in the retina, and peripheral leukocytes formed close contact with the RPE Our findings further implied that the ocular milieu can confer monocytes a phenotype advantageous for neuroprotection. These results suggest that the eye utilizes a mechanism of crosstalk with the immune system similar to that of the brain, whereby epithelial barriers serve as gateways for leukocyte entry. PMID:27107049

  14. Obesity, cholesterol metabolism, and breast cancer pathogenesis.

    PubMed

    McDonnell, Donald P; Park, Sunghee; Goulet, Matthew T; Jasper, Jeff; Wardell, Suzanne E; Chang, Ching-Yi; Norris, John D; Guyton, John R; Nelson, Erik R

    2014-09-15

    Obesity and altered lipid metabolism are risk factors for breast cancer in pre- and post-menopausal women. These pathologic relationships have been attributed in part to the impact of cholesterol on the biophysical properties of cell membranes and to the influence of these changes on signaling events initiated at the membrane. However, more recent studies have indicated that the oxysterol 27-hydroxycholesterol (27HC), and not cholesterol per se, may be the primary biochemical link between lipid metabolism and cancer. The enzyme responsible for production of 27HC from cholesterol, CYP27A1, is expressed primarily in the liver and in macrophages. In addition, significantly elevated expression of this enzyme within breast tumors has also been observed. It is believed that 27HC, acting through the liver X receptor in macrophages and possibly other cells, is involved in maintaining organismal cholesterol homeostasis. It has also been shown recently that 27HC is an estrogen receptor agonist in breast cancer cells and that it stimulates the growth and metastasis of tumors in several models of breast cancer. These findings provide the rationale for the clinical evaluation of pharmaceutical approaches that interfere with cholesterol/27HC synthesis as a means to mitigate the impact of cholesterol on breast cancer pathogenesis. Cancer Res; 74(18); 4976-82. ©2014 AACR. PMID:25060521

  15. Cholesterol suppresses antimicrobial effect of statins

    PubMed Central

    Haeri, Mohammad Reza; White, Kenneth; Qharebeglou, Mohammad; Ansar, Malek Moein

    2015-01-01

    Objective(s): Isoprenoid biosynthesis is a key metabolic pathway to produce a wide variety of biomolecules such as cholesterol and carotenoids, which target cell membranes. On the other hand, it has been reported that statins known as inhibitors of isoprenoid biosynthesis and cholesterol lowering agents, may have a direct antimicrobial effect on the some bacteria. The exact action of statins in microbial metabolism is not clearly understood. It is possible that statins inhibit synthesis or utilization of some sterol precursor necessary for bacterial membrane integrity. Accordingly, this study was designed in order to examine if statins inhibit the production of a compound, which can be used in the membrane, and whether cholesterol would replace it and rescue bacteria from toxic effects of statins. Materials and Methods: To examine the possibility we assessed antibacterial effect of statins with different classes; lovastatin, simvastatin, and atorvastatin, alone and in combination with cholesterol on two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria using gel diffusion assay. Results: Our results showed that all of the statins except for lovastatin had significant antibacterial property in S. aureus, E. coli, and Enter. faecalis. Surprisingly, cholesterol nullified the antimicrobial action of effective statins in statin-sensitive bacteria. Conclusion: It is concluded that statins may deprive bacteria from a metabolite responsible for membrane stability, which is effectively substituted by cholesterol. PMID:26877857

  16. Impaired cholesterol esterification in primary brain cultures of the lysosomal cholesterol storage disorder (LCSD) mouse mutant

    SciTech Connect

    Patel, S.C.; Suresh, S.; Weintroub, H.; Brady, R.O.; Pentchev, P.G.

    1987-02-27

    Esterification of cholesterol was investigated in primary neuroglial cultures obtained from newborn lysosomal cholesterol storage disorder (LCSD) mouse mutants. An impairment in /sup 3/H-oleic acid incorporation into cholesteryl esters was demonstrated in cultures of homozygous LCSD brain. Primary cultures derived from other phenotypically normal pups of the carrier breeders esterified cholesterol at normal levels or at levels which were intermediary between normal and deficient indicating a phenotypic expression of the LCSD heterozygote genotype. These observations on LCSD mutant brain cells indicate that the defect in cholesterol esterification is closely related to the primary genetic defect and is expressed in neuroglial cells in culture.

  17. Stereoselective recognition of monolayers of cholesterol, ent-cholesterol, and epicholesterol by an antibody.

    PubMed

    Geva, M; Izhaky, D; Mickus, D E; Rychnovsky, S D; Addadi, L

    2001-04-01

    The interaction between a monoclonal antibody and four distinct monolayers with varying degrees of structural, chemical, and stereochemical similarity were studied and quantified. The antibody, raised and selected against cholesterol monohydrate crystals, interacts with cholesterol monolayers stereospecifically, but not enantiospecifically. Monolayers of ent-cholesterol molecules, which are chemically identical to cholesterol and whose structure is the exact mirror image of the cholesterol monolayer, interact with the antibody to the same extent as the cholesterol monolayers. The affinity of the antibody for both enantiomeric monolayers is extremely high. However, the antibody does not interact with monolayers of epicholesterol, which is an epimer of cholesterol: The hydroxy group in epicholesterol is in the 3alpha position rather than in the 3beta position, imposing a different angle between the hydroxy group and the rigid steroid backbone, and a different packing of the molecules. Monolayers of triacontanol, a long-chain primary aliphatic alcohol, interact with the antibody to a lesser extent than the cholesterol and ent-cholesterol monolayers, presumably due to the structural flexibility of the triacontanol molecule. The lack of chiral discrimination by the antibody is thus correlated to the level at which the chirality is exposed at the surface of the monolayers.

  18. Parallel simulation today

    NASA Technical Reports Server (NTRS)

    Nicol, David; Fujimoto, Richard

    1992-01-01

    This paper surveys topics that presently define the state of the art in parallel simulation. Included in the tutorial are discussions on new protocols, mathematical performance analysis, time parallelism, hardware support for parallel simulation, load balancing algorithms, and dynamic memory management for optimistic synchronization.

  19. Verbal and Visual Parallelism

    ERIC Educational Resources Information Center

    Fahnestock, Jeanne

    2003-01-01

    This study investigates the practice of presenting multiple supporting examples in parallel form. The elements of parallelism and its use in argument were first illustrated by Aristotle. Although real texts may depart from the ideal form for presenting multiple examples, rhetorical theory offers a rationale for minimal, parallel presentation. The…

  20. The N-terminal Domain of NPC1L1 Protein Binds Cholesterol and Plays Essential Roles in Cholesterol Uptake*

    PubMed Central

    Zhang, Jin-Hui; Ge, Liang; Qi, Wei; Zhang, Liqing; Miao, Hong-Hua; Li, Bo-Liang; Yang, Maojun; Song, Bao-Liang

    2011-01-01

    Niemann-Pick C1-like 1 (NPC1L1) is a multitransmembrane protein playing a crucial role in dietary and biliary cholesterol absorption. Cholesterol promotes the formation and endocytosis of NPC1L1-flotillin-cholesterol membrane microdomains, which is an early step in cholesterol uptake. How cholesterol is sensed in this step is unknown. Here, we find that the N-terminal domain (NTD) of NPC1L1 binds cholesterol. Mutation of residue Leu-216 in NPC1L1-NTD eliminates cholesterol binding, decreases the formation of NPC1L1-flotillin-cholesterol membrane microdomains, and prevents NPC1L1-mediated cholesterol uptake in culture cells and mice livers. NPC1L1-NTD specifically binds cholesterol but not plant sterols, which may account for the selective cholesterol absorption in intestine. Furthermore, 25- or 27-hydroxycholesterol competes with cholesterol to bind NPC1L1-NTD and inhibits the cholesterol induced endocytosis of NPC1L1. Together, these results demonstrate that plasma membrane-localized NPC1L1 binds exogenous cholesterol via its NTD, and facilitates the formation of NPC1L1-flotillin-cholesterol membrane microdomains that are then internalized into cells through the clathrin-AP2 pathway. Our study uncovers the mechanism of cholesterol sensing by NPC1L1 and proposes a mechanism for selective cholesterol absorption. PMID:21602275

  1. The Anatomy of Human Trafficking: Learning About the Blues: A Healthcare Provider's Guide.

    PubMed

    Stevens, Meriam; Berishaj, Kelly

    2016-01-01

    Human trafficking is a major global public health concern. It is a grave crime that violates human rights. Contrary to healthcare providers' perceptions, victims of human trafficking come in contact with the healthcare system while being trafficked, with the emergency department being the most frequented setting for medical treatment. In this article, we explore the anatomy of human trafficking, including the scope of the problem, definitions, and types and elements of human trafficking. The roles of clinicians, particularly emergency department nurses and advanced practice nurses, in screening and identifying those at risk are examined. Clinical practice tools and guidelines that may be used by clinicians to guide the treatment of human trafficking victims are reviewed. Finally, current strategies and resources that address human trafficking are presented. For the purpose of this article, the terms "human trafficking" or "trafficking" will be used throughout.

  2. Parallel algorithm development

    SciTech Connect

    Adams, T.F.

    1996-06-01

    Rapid changes in parallel computing technology are causing significant changes in the strategies being used for parallel algorithm development. One approach is simply to write computer code in a standard language like FORTRAN 77 or with the expectation that the compiler will produce executable code that will run in parallel. The alternatives are: (1) to build explicit message passing directly into the source code; or (2) to write source code without explicit reference to message passing or parallelism, but use a general communications library to provide efficient parallel execution. Application of these strategies is illustrated with examples of codes currently under development.

  3. Human trafficking and health: a conceptual model to inform policy, intervention and research.

    PubMed

    Zimmerman, Cathy; Hossain, Mazeda; Watts, Charlotte

    2011-07-01

    Human trafficking is an international crime renowned for extreme forms of violence against women, men and children. Although trafficking-related violence has been well-documented, the health of trafficked persons has been a largely neglected topic. For people who are trafficked, health risks and consequences may begin before they are recruited into the trafficking process, continue throughout the period of exploitation and persist even after individuals are released. Policy-making, service provision and research often focus narrowly on criminal violations that occur during the period of exploitation, regularly overlooking the health implications of trafficking. Similarly, the public health sector has not yet incorporated human trafficking as a health concern. We present a conceptual model that highlights the migratory and exploitative nature of a multi-staged trafficking process, which includes: 'recruitment', travel-transit', 'exploitation' and 'integration' or 'reintegration', and for some trafficked persons, 'detention' and 're-trafficking' stages. Trafficked persons may suffer from physical, sexual and psychological harm, occupational hazards, legal restrictions and difficulties associated with being marginalised or stigmatised. Researchers and decision-makers will benefit from a theoretical approach that conceptualizes trafficking and health as a multi-staged process of cumulative harm. To address a health risk such as trafficking, which spans geographical boundaries and involves multiple sectors, including immigration and law enforcement, labour, social and health services, interventions must be coordinated between nations and across sectors to promote the protection and recovery of people who are trafficked.

  4. Distribution and Spectroscopy of Green Fluorescent Protein and Acyl-CoA: Cholesterol Acytransferase in Sf21 Insect Cells

    NASA Technical Reports Server (NTRS)

    Richmond, R. C.; Mahtani, H.; Lu, X.; Chang, T. Y.; Malak, H.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Acyl-CoA: cholesterol acyltransferase (ACAT) is thought to significantly participate in the pathway of cholesterol esterification that underlies the pathology of artherosclerosis. This enzyme is a membrane protein known to be preferentially bound within the endoplasmic reticulum of mammalian cells, from which location it esterifies cholesterol derived from low density lipoprotein. Cultures of insect cells were separately infected with baculovirus containing the gene for green fluroescent protein (GFP) and with baculovirus containing tandem genes for GFP and ACAT. These infected cultures expressed GFP and the fusion protein GCAT, respectively, with maximum expression occurring on the fourth day after infection. Extraction of GFP- and of GCAT-expressing cells with urea and detergent resulted in recovery of fluorescent protein in aqueous solution. Fluorescence spectra at neutral pH were identical for both GFP and GCAT extracts in aqueous solution, indicating unperturbed tertiary structure for the GFP moiety within GCAT. In a cholesterol esterification assay, GCAT demonstrated ACAT activity, but with less efficiency compared to native ACAT. It was hypothesized that the membrane protein ACAT would lead to differences in localization of GCAT compared to GFP within the respective expressing insect cells. The GFP marker directly and also within the fusion protein GCAT was accordingly used as the intracellular probe that was fluorescently analyzed by the new biophotonics technique of hyperspectral imaging. In that technique, fluorescence imaging was obtained from two dimensional arrays of cells, and regions of interest from within those images were then retrospectively analyzed for the emission spectra that comprises the image. Results of hyperspectral imaging of insect cells on day 4 postinfection showed that GCAT was preferentially localized to the cytoplasm of these cells compared to GFP. Furthermore, the emission spectra obtained for the localized GCAT displayed a peak

  5. Human trafficking: Role of oral health care providers.

    PubMed

    Nuzzolese, E

    2014-11-01

    Trafficking in human beings is a modern form of slavery and is a well-known phenomenon throughout the European Union and beyond. After drug dealing and the weapons industry, human trafficking is the second largest criminal activity in the world today and it is a growing crime. The aim of governmental and non-governmental agencies, which are either directly or indirectly involved in combating trafficking in human beings, is the identification and referral of victims of trafficking and also to encourage self-referrals. Identification is the most important step to provide protection and assistance to victims of trafficking. Victims often have a variety of physical and mental health needs, including psychological trauma, injuries from violence, head and neck trauma, sexually transmitted infections and other gynaecological problems, dental/oral problems and have poor nutrition. The author's experience in the field of community dentistry in presented within. Volunteer dental services are offered to non-European Union patients held in a centre for asylum seekers in Bari (Italy). Dental professionals can, in fact, contribute to the identification, assistance and protection of trafficked persons, as well as offering forensic services to assist the police investigation in order to identify crimes and find the criminal organizations behind them. As for domestic violence and child abuse cases, there are ethical concerns involved in the identification and protection of the trafficked persons, as well as the need for interdisciplinary work and awareness. Adequate training in behavioural science and intercultural learning is paramount in order to avoid misunderstandings and increase sensitivity. PMID:25557409

  6. Human trafficking: Role of oral health care providers.

    PubMed

    Nuzzolese, E

    2014-11-30

    Trafficking in human beings is a modern form of slavery and is a well-known phenomenon throughout the European Union and beyond. After drug dealing and the weapons industry, human trafficking is the second largest criminal activity in the world today and it is a growing crime. The aim of governmental and non-governmental agencies, which are either directly or indirectly involved in combating trafficking in human beings, is the identification and referral of victims of trafficking and also to encourage self-referrals. Identification is the most important step to provide protection and assistance to victims of trafficking. Victims often have a variety of physical and mental health needs, including psychological trauma, injuries from violence, head and neck trauma, sexually transmitted infections and other gynaecological problems, dental/oral problems and have poor nutrition. The author's experience in the field of community dentistry in presented within. Volunteer dental services are offered to non-European Union patients held in a centre for asylum seekers in Bari (Italy). Dental professionals can, in fact, contribute to the identification, assistance and protection of trafficked persons, as well as offering forensic services to assist the police investigation in order to identify crimes and find the criminal organizations behind them. As for domestic violence and child abuse cases, there are ethical concerns involved in the identification and protection of the trafficked persons, as well as the need for interdisciplinary work and awareness. Adequate training in behavioural science and intercultural learning is paramount in order to avoid misunderstandings and increase sensitivity.

  7. Mitochondrial regulation of macrophage cholesterol homeostasis.

    PubMed

    Graham, Annette

    2015-12-01

    This review explores the relationship between mitochondrial structure and function in the regulation of macrophage cholesterol metabolism and proposes that mitochondrial dysfunction contributes to loss of the elegant homeostatic mechanisms which normally maintain cellular sterol levels within defined limits. Mitochondrial sterol 27-hydroxylase (CYP27A1) can generate oxysterol activators of liver X receptors which heterodimerise with retinoid X receptors, enhancing the transcription of ATP binding cassette transporters (ABCA1, ABCG1, and ABCG4), that can remove excess cholesterol via efflux to apolipoproteins A-1, E, and high density lipoprotein, and inhibit inflammation. The activity of CYP27A1 is regulated by the rate of supply of cholesterol substrate to the inner mitochondrial membrane, mediated by a complex of proteins. The precise identity of this dynamic complex remains controversial, even in steroidogenic tissues, but may include steroidogenic acute regulatory protein and the 18 kDa translocator protein, together with voltage-dependent anion channels, ATPase AAA domain containing protein 3A, and optic atrophy type 1 proteins. Certainly, overexpression of StAR and TSPO proteins can enhance macrophage cholesterol efflux to apoA-I and/or HDL, while perturbations in mitochondrial function, or changes in the expression of mitochondrial fusion proteins, alter the efficiency of cholesterol efflux. Molecules which can sustain or improve mitochondrial function or increase the activity of the protein complex involved in cholesterol transfer may have utility in resolving the problem of dysregulated macrophage cholesterol homeostasis, a condition which may contribute to inflammation, atherosclerosis, nonalcoholic steatohepatitis, osteoblastic bone resorption, and some disorders of the central nervous system.

  8. The absorption of cholesterol and the sterol balance in the Tarahumara Indians of Mexico fed cholesterol-free and high cholesterol diets.

    PubMed

    McMurry, M P; Connor, W E; Lin, D S; Cerqueira, M T; Connor, S L

    1985-06-01

    The Tarahumara Indians of Mexico are habituated to a very low cholesterol, low fat diet and have lifelong low plasma cholesterol concentrations. To study cholesterol metabolism in these unusual people, 8 Tarahumara men were fed sequentially a cholesterol-free diet and then a diet containing 900 mg cholesterol under controlled conditions. The intestinal absorption of cholesterol, fecal steroid excretion and sterol balance were determined. During the high cholesterol diet period, the plasma cholesterol level increased from 113 +/- 8 mg/dl to 147 +/- 11 mg/dl (means +/- SD). Cholesterol biosynthesis decreased from 14.0 +/- 0.7 to 7.1 +/- 1.0 mg/kg/day (means +/- SE). The intestinal absorption of cholesterol was 27.7 +/- 6.7% (means +/- SE) during both dietary periods. Compared to other cultures, Tarahumaras had a reduced ability to absorb dietary cholesterol and higher total sterol turnover primarily because of an increased bile acid output. The total sterol disposition over three weeks of the high cholesterol diet accounted for all the absorbed dietary cholesterol.

  9. Educating Health Care Professionals on Human Trafficking

    PubMed Central

    Grace, Aimee M.; Lippert, Suzanne; Collins, Kristin; Pineda, Noelle; Tolani, Alisha; Walker, Rebecca; Jeong, Monica; Trounce, Milana Boukhman; Graham-Lamberts, Caroline; Bersamin, Melina; Martinez, Det. Jeremy; Dotzler, Det. Jennifer; Vanek, Lt John; Storfer-Isser, Amy; Chamberlain, Lisa J.; Horwitz, Sarah M.

    2015-01-01

    Background The US Department of State estimates that there are between 4 and 27 million individuals worldwide in some form of modern slavery. Recent studies have demonstrated that 28% to 50% of trafficking victims in the United States encountered health care professionals while in captivity, but were not identified and recognized. This study aimed to determine whether an educational presentation increased emergency department (ED) providers' recognition of human trafficking (HT) victims and knowledge of resources to manage cases of HT. Methods The 20 largest San Francisco Bay Area EDs were randomized into intervention (10 EDs) or delayed intervention comparison groups (10 EDs) to receive a standardized educational presentation containing the following: background about HT, relevance of HT to health care, clinical signs in potential victims, and referral options for potential victims. Participants in the delayed intervention group completed a pretest in the period the immediate intervention group received the educational presentation, and all participants were assessed immediately before (pretest) and after (posttest) the intervention. The intervention effect was tested by comparing the pre–post change in the intervention group to the change in 2 pretests in the delayed intervention group adjusted for the effect of clustering within EDs. The 4 primary outcomes were importance of knowledge of HT to the participant's profession (5-point Likert scale), self-rated knowledge of HT (5-point Likert scale), knowledge of who to call for potential HT victims (yes/no), and suspecting that a patient was a victim of HT (yes/no). Findings There were 258 study participants from 14 EDs; 141 from 8 EDs in the intervention group and 117 from 7 EDs in the delayed intervention comparison group, of which 20 served as the delayed intervention comparison group. Participants in the intervention group reported greater increases in their level of knowledge about HT versus those in the

  10. Prevention of cholesterol gallstones by inhibiting hepatic biosynthesis and intestinal absorption of cholesterol

    PubMed Central

    Wang, Helen H; Portincasa, Piero; de Bari, Ornella; Liu, Kristina J; Garruti, Gabriella; Neuschwander-Tetri, Brent A; Wang, David Q.-H

    2013-01-01

    Cholesterol cholelithiasis is a multifactorial disease influenced by a complex interaction of genetic and environmental factors, and represents a failure of biliary cholesterol homeostasis in which the physical-chemical balance of cholesterol solubility in bile is disturbed. The primary pathophysiologic event is persistent hepatic hypersecretion of biliary cholesterol, which has both hepatic and small intestinal components. The majority of the environmental factors are probably related to Western-type dietary habits, including excess cholesterol consumption. Laparoscopic cholecystectomy, one of the most commonly performed surgical procedures in the US, is nowadays a major treatment for gallstones. However, it is invasive and can cause surgical complications, and not all patients with symptomatic gallstones are candidates for surgery. The hydrophilic bile acid, ursodeoxycholic acid (UDCA) has been employed as first-line pharmacological therapy in a subgroup of symptomatic patients with small, radiolucent cholesterol gallstones. Long-term administration of UDCA can promote the dissolution of cholesterol gallstones. However, the optimal use of UDCA is not always achieved in clinical practice because of failure to titrate the dose adequately. Therefore, the development of novel, effective, and noninvasive therapies is crucial for reducing the costs of health care associated with gallstones. In this review, we summarize recent progress in investigating the inhibitory effects of ezetimibe and statins on intestinal absorption and hepatic biosynthesis of cholesterol, respectively, for the treatment of gallstones, as well as in elucidating their molecular mechanisms by which combination therapy could prevent this very common liver disease worldwide. PMID:23419155

  11. Phase separation of cholesterol and the interaction of ethanol with phosphatidylserine-cholesterol bilayer membranes.

    PubMed

    Bach, D; Borochov, N; Wachtel, E

    2002-02-01

    Thermotropic and structural effects of ethanol on phosphatidylserine (PS) membranes containing up to 0.4 mol fraction cholesterol were investigated by differential scanning calorimetry, X-ray diffraction and fluorescence spectroscopy. It was found that in the presence of cholesterol, 10% (v/v) added ethanol depresses the melting temperature of the phospholipid by approximately 2 degrees C, similar to what was observed in the absence of cholesterol. Below the melting temperature the progressive disordering effect of added cholesterol is weakly enhanced by the presence of ethanol. In the liquid crystalline state, the marked decrease in the thickness of the bilayer which ethanol causes in the absence of cholesterol (Chem. Phys. Lipids 92 (1998) 127), is also observed in its presence. We conclude that, in contrast to what has been observed for zwitterionic phospholipids, high concentrations of cholesterol do not diminish the interaction of ethanol with PS membranes. With addition of 10% (v/v) ethanol, crystalline cholesterol diffraction, an indication of phase separation of the sterol, appears at mol fraction cholesterol 0.34, as compared to 0.3 in the absence of ethanol (Chem. Phys. Lipids 92 (1998) 71).

  12. A diet rich in leafy vegetable fiber improves cholesterol metabolism in high-cholesterol fed rats.

    PubMed

    Ezz El-Arab, A M

    2009-10-01

    In the present study, the hypocholesterolemic effect of leaf vegetable (Jew's mallow) was studied in high-cholesterol fed rats. The animals were fed diets supplemented with cholesterol (0.25%) for 4 weeks. Leaf vegetable diet produced an important hypocholesterolemic action: it led to a significant lowering (p<0.05) of cholesterol in the plasma and liver, as well as of the atherogenic index and a significant increase (p<0.05) in cecal short chain fatty acids, with respect to the control group. Concurrently, total fecal neutral sterols in the excretion increased (p<0.05) and apparent absorption of dietary cholesterol was significantly depressed (-58%). The consumption of leaf vegetable (Jew's mallow) with a hypercholesterolemic diet improved the lipidemic profile and increased excretion of the total cholesterol end-products. PMID:20387744

  13. A diet rich in leafy vegetable fiber improves cholesterol metabolism in high-cholesterol fed rats.

    PubMed

    Ezz El-Arab, A M

    2009-10-01

    In the present study, the hypocholesterolemic effect of leaf vegetable (Jew's mallow) was studied in high-cholesterol fed rats. The animals were fed diets supplemented with cholesterol (0.25%) for 4 weeks. Leaf vegetable diet produced an important hypocholesterolemic action: it led to a significant lowering (p<0.05) of cholesterol in the plasma and liver, as well as of the atherogenic index and a significant increase (p<0.05) in cecal short chain fatty acids, with respect to the control group. Concurrently, total fecal neutral sterols in the excretion increased (p<0.05) and apparent absorption of dietary cholesterol was significantly depressed (-58%). The consumption of leaf vegetable (Jew's mallow) with a hypercholesterolemic diet improved the lipidemic profile and increased excretion of the total cholesterol end-products.

  14. [Trans-intestinal cholesterol excretion (TICE): a new route for cholesterol excretion].

    PubMed

    Blanchard, Claire; Moreau, François; Cariou, Bertrand; Le May, Cédric

    2014-10-01

    The small intestine plays a crucial role in dietary and biliary cholesterol absorption, as well as its lymphatic secretion as chylomicrons (lipoprotein exogenous way). Recently, a new metabolic pathway called TICE (trans-intestinal excretion of cholesterol) that plays a central role in cholesterol metabolism has emerged. TICE is an inducible way, complementary to the hepatobiliary pathway, allowing the elimination of the plasma cholesterol directly into the intestine lumen through the enterocytes. This pathway is poorly characterized but several molecular actors of TICE have been recently identified. Although it is a matter of debate, two independent studies suggest that TICE is involved in the anti-atherogenic reverse cholesterol transport pathway. Thus, TICE is an innovative drug target to reduce -cardiovascular diseases.

  15. Glucagon receptor antagonism induces increased cholesterol absorption.

    PubMed

    Guan, Hong-Ping; Yang, Xiaodong; Lu, Ku; Wang, Sheng-Ping; Castro-Perez, Jose M; Previs, Stephen; Wright, Michael; Shah, Vinit; Herath, Kithsiri; Xie, Dan; Szeto, Daphne; Forrest, Gail; Xiao, Jing Chen; Palyha, Oksana; Sun, Li-Ping; Andryuk, Paula J; Engel, Samuel S; Xiong, Yusheng; Lin, Songnian; Kelley, David E; Erion, Mark D; Davis, Harry R; Wang, Liangsu

    2015-11-01

    Glucagon and insulin have opposing action in governing glucose homeostasis. In type 2 diabetes mellitus (T2DM), plasma glucagon is characteristically elevated, contributing to increased gluconeogenesis and hyperglycemia. Therefore, glucagon receptor (GCGR) antagonism has been proposed as a pharmacologic approach to treat T2DM. In support of this concept, a potent small-molecule GCGR antagonist (GRA), MK-0893, demonstrated dose-dependent efficacy to reduce hyperglycemia, with an HbA1c reduction of 1.5% at the 80 mg dose for 12 weeks in T2DM. However, GRA treatment was associated with dose-dependent elevation of plasma LDL-cholesterol (LDL-c). The current studies investigated the cause for increased LDL-c. We report findings that link MK-0893 with increased glucagon-like peptide 2 and cholesterol absorption. There was not, however, a GRA-related modulation of cholesterol synthesis. These findings were replicated using structurally diverse GRAs. To examine potential pharmacologic mitigation, coadministration of ezetimibe (a potent inhibitor of cholesterol absorption) in mice abrogated the GRA-associated increase of LDL-c. Although the molecular mechanism is unknown, our results provide a novel finding by which glucagon and, hence, GCGR antagonism govern cholesterol metabolism.

  16. Dual roles for cholesterol in mammalian cells.

    PubMed

    Xu, Fang; Rychnovsky, Scott D; Belani, Jitendra D; Hobbs, Helen H; Cohen, Jonathan C; Rawson, Robert B

    2005-10-11

    The structural features of sterols required to support mammalian cell growth have not been fully defined. Here, we use mutant CHO cells that synthesize only small amounts of cholesterol to test the capacity of various sterols to support growth. Sterols with minor modifications of the side chain (e.g., campesterol, beta-sitosterol, and desmosterol) supported long-term growth of mutant cells, but sterols with more complex modifications of the side chain, the sterol nucleus, or the 3-hydroxy group did not. After 60 days in culture, the exogenous sterol comprised >90% of cellular sterols. Inactivation of residual endogenous synthesis with the squalene epoxidase inhibitor NB-598 prevented growth in beta-sitosterol and greatly reduced growth in campesterol. Growth of cells cultured in beta-sitosterol and NB-598 was restored by adding small amounts of cholesterol to the medium. Surprisingly, enantiomeric cholesterol also supported cell growth, even in the presence of NB-598. Thus, sterols fulfill two roles in mammalian cells: (i) a bulk membrane requirement in which phytosterols can substitute for cholesterol and (ii) other processes that specifically require small amounts of cholesterol but are not enantioselective. PMID:16199524

  17. LDL cholesterol: controversies and future therapeutic directions.

    PubMed

    Ridker, Paul M

    2014-08-16

    Lifelong exposure to raised concentrations of LDL cholesterol increases cardiovascular event rates, and the use of statin therapy as an adjunct to diet, exercise, and smoking cessation has proven highly effective in reducing the population burden associated with hyperlipidaemia. Yet, despite consistent biological, genetic, and epidemiological data, and evidence from randomised trials, there is controversy among national guidelines and clinical practice with regard to LDL cholesterol, its measurement, the usefulness of population-based screening, the net benefit-to-risk ratio for different LDL-lowering drugs, the benefit of treatment targets, and whether aggressive lowering of LDL is safe. Several novel therapies have been introduced for the treatment of people with genetic defects that result in loss of function within the LDL receptor, a major determinant of inherited hyperlipidaemias. Moreover, the usefulness of monoclonal antibodies that extend the LDL-receptor lifecycle (and thus result in substantial lowering of LDL cholesterol below the levels achieved with statins alone) is being assessed in phase 3 trials that will enrol more than 60,000 at-risk patients worldwide. These trials represent an exceptionally rapid translation of genetic observations into clinical practice and will address core questions of how low LDL cholesterol can be safely reduced, whether the mechanism of LDL-cholesterol lowering matters, and whether ever more aggressive lipid-lowering provides a safe, long-term mechanism to prevent atherothrombotic complications.

  18. Plasma cholesterol transport in anhepatic rats.

    PubMed Central

    Quarfordt, S H; Landis, B; Cucchiaro, G; Yamaguchi, Y; Oswald, B

    1992-01-01

    The plasma appearance of newly synthesized cholesterol in anhepatic laboratory diet-fed rats was 10% of the intact rat. In intact rats this cholesterol was mainly ester in lower density lipoproteins, but for anhepatic rats it was virtually only free in high density lipoprotein. Chylomicron cholesterol ester was removed much more slowly from anhepatic than control plasma and returned primarily as free in high density lipoproteins, with the control return 10 times the anhepatic return. Lower density lipoprotein cholesterol ester transfer to an extravascular pool in anhepatic rats was less than 10% of controls. The liver was responsible for 95% of the extravascular lower density lipoprotein ester pool and only 50% of the for high density lipoprotein ester. Despite decreased anhepatic lipoprotein catabolism, the mass of both plasma low and high density lipoproteins progressively decreased indicating an even greater decrease in influx. The anhepatic fractional catabolic rate of apo A1 was similar to controls, but that of apo E was considerably less. Despite the unchanged catabolism of apo A1 and the reduced catabolism of apo E, plasma apo A1 decreased less than apo E after hepatectomy. The anhepatic data confirm the pivotal role of the liver in maintaining plasma low and high density lipoprotein cholesterol concentrations. They suggest that, in addition to its anabolic and catabolic functions, the liver also acts as a reservoir buffering changes in plasma concentration. Images PMID:1569195

  19. National Human Trafficking Initiatives: Dimensions of Policy Diffusion1

    PubMed Central

    Yoo, Eun-hye; Boyle, Elizabeth Heger

    2014-01-01

    The implementation of criminal law involves formal law enforcement, education and public outreach aimed at preventing criminal activity, and providing services for victims. Historically, quantitative research on global trends has tended to focus on a single policy dimension, potentially masking the unique factors that affect the diffusion of each policy dimension independently. Using an ordered-probit model to analyze new human trafficking policy data on national prosecution, prevention, and victim-protection efforts, we find that global ties and domestic interest groups matter more in areas where international law is less defined. While prosecution, officially mandated by the Trafficking Protocol, was relatively impervious to global ties and domestic interest groups, both trafficking prevention and victim protection were associated with these factors. Our findings also suggest that fear of repercussions is not a major driver of state actions to combat trafficking—neither ratification of the Trafficking Protocol nor levels of United States aid were associated with greater implementation of anti-trafficking measures. PMID:26538806

  20. Regulation of GPCR Anterograde Trafficking by Molecular Chaperones and Motifs.

    PubMed

    Young, Brent; Wertman, Jaime; Dupré, Denis J

    2015-01-01

    G protein-coupled receptors (GPCRs) make up a superfamily of integral membrane proteins that respond to a wide variety of extracellular stimuli, giving them an important role in cell function and survival. They have also proven to be valuable targets in the fight against various diseases. As such, GPCR signal regulation has received considerable attention over the last few decades. With the amplitude of signaling being determined in large part by receptor density at the plasma membrane, several endogenous mechanisms for modulating GPCR expression at the cell surface have come to light. It has been shown that cell surface expression is determined by both exocytic and endocytic processes. However, the body of knowledge surrounding GPCR trafficking from the endoplasmic reticulum to the plasma membrane, commonly known as anterograde trafficking, has considerable room for growth. We focus here on the current paradigms of anterograde GPCR trafficking. We will discuss the regulatory role of both the general and "nonclassical private" chaperone systems in GPCR trafficking as well as conserved motifs that serve as modulators of GPCR export from the endoplasmic reticulum and Golgi apparatus. Together, these topics summarize some of the known mechanisms by which the cell regulates anterograde GPCR trafficking. PMID:26055064

  1. Localization of cholesterol in sphingomyelinase-treated fibroblasts.

    PubMed Central

    Pörn, M I; Slotte, J P

    1995-01-01

    The distribution of cellular unesterified cholesterol was studied in fibroblasts, which had been depleted of plasma membrane sphingomyelin by exposure to exogenous sphingomyelinase. This treatment has previously been shown to induce an increase in cholesterol esterification, a decrease in the biosynthesis of cholesterol, and a decreased susceptibility of cell cholesterol to oxidation with cholesterol oxidase. When the cellular localization of cholesterol was studied with fluorescent filipin staining, sphingomyelin depletion did not cause any visible changes in the filipin-cholesterol staining pattern, suggesting that the major part of cellular cholesterol was retained in the plasma membrane after sphingomyelinase treatment. After the oxidation of cell-surface cholesterol with cholesterol oxidase, the plasma membrane was no longer stained by filipin, but the plasma membrane cholesterol of sphingomyelin-depleted cells appeared to be resistant to oxidation with cholesterol oxidase when sphingomyelinase was used as an oxidation-promoting agent. However, the use of hypotonic buffer or phosphatidylcholine-specific phospholipase C together with cholesterol oxidase resulted in a complete oxidation of the cell-surface cholesterol in sphingomyelin-depleted cells, as evidenced by the filipin-cholesterol staining pattern. Similar results were obtained when [3H]cholesterol-labelled fibroblasts were used for determination of the susceptibility to cholesterol oxidation. The kinetics of [3H]cholesterol oxidation in sphingomyelin-depleted cells with cholesterol oxidase in hypotonic buffer indicated that approximately 85% of the cellular cholesterol still resided in the plasma membrane after sphingomyelin depletion. These results are contradictory to earlier reports on sphingomyelinase-induced changes in cellular cholesterol distribution and suggest that minor changes in the kinetics of cholesterol transport from the plasma membrane to the endoplasmic reticulum may be responsible

  2. Localization of cholesterol in sphingomyelinase-treated fibroblasts.

    PubMed

    Pörn, M I; Slotte, J P

    1995-05-15

    The distribution of cellular unesterified cholesterol was studied in fibroblasts, which had been depleted of plasma membrane sphingomyelin by exposure to exogenous sphingomyelinase. This treatment has previously been shown to induce an increase in cholesterol esterification, a decrease in the biosynthesis of cholesterol, and a decreased susceptibility of cell cholesterol to oxidation with cholesterol oxidase. When the cellular localization of cholesterol was studied with fluorescent filipin staining, sphingomyelin depletion did not cause any visible changes in the filipin-cholesterol staining pattern, suggesting that the major part of cellular cholesterol was retained in the plasma membrane after sphingomyelinase treatment. After the oxidation of cell-surface cholesterol with cholesterol oxidase, the plasma membrane was no longer stained by filipin, but the plasma membrane cholesterol of sphingomyelin-depleted cells appeared to be resistant to oxidation with cholesterol oxidase when sphingomyelinase was used as an oxidation-promoting agent. However, the use of hypotonic buffer or phosphatidylcholine-specific phospholipase C together with cholesterol oxidase resulted in a complete oxidation of the cell-surface cholesterol in sphingomyelin-depleted cells, as evidenced by the filipin-cholesterol staining pattern. Similar results were obtained when [3H]cholesterol-labelled fibroblasts were used for determination of the susceptibility to cholesterol oxidation. The kinetics of [3H]cholesterol oxidation in sphingomyelin-depleted cells with cholesterol oxidase in hypotonic buffer indicated that approximately 85% of the cellular cholesterol still resided in the plasma membrane after sphingomyelin depletion. These results are contradictory to earlier reports on sphingomyelinase-induced changes in cellular cholesterol distribution and suggest that minor changes in the kinetics of cholesterol transport from the plasma membrane to the endoplasmic reticulum may be responsible

  3. Melatonin directly interacts with cholesterol and alleviates cholesterol effects in dipalmitoylphosphatidylcholine monolayers.

    PubMed

    Choi, Youngjik; Attwood, Simon J; Hoopes, Matthew I; Drolle, Elizabeth; Karttunen, Mikko; Leonenko, Zoya

    2014-01-01

    Melatonin is a pineal hormone that has been shown to have protective effects in several diseases that are associated with cholesterol dysregulation, including cardiovascular disease, Alzheimer's disease, and certain types of cancers. Cholesterol is a major membrane constituent with both a structural and functional influence. It is also known that melatonin readily partitions into cellular membranes. We investigated the effects of melatonin and cholesterol on the structure and physical properties of a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer as a simple membrane model using the Langmuir-Blodgett (L-B) monolayer technique and molecular dynamics (MD) simulations. We report that melatonin increases the area per lipid and elastic compressibility of the DPPC monolayer in a concentration dependent manner, while cholesterol has the opposite effect. When both melatonin and cholesterol were present in the monolayer, the compression isotherms showed normalization of the area per molecule towards that of the pure DPPC monolayer, thus indicating that melatonin counteracts and alleviates cholesterol's effects. Atomistic MD simulations of melatonin enriched DPPC systems correlate with our experimental findings and illustrate the structural effects of both cholesterol and melatonin. Our results suggest that melatonin is able to lessen the influence of cholesterol through two different mechanisms. Firstly, we have shown that melatonin has a fluidizing effect on monolayers comprising only lipid molecules. Secondly, we also observe that melatonin interacts directly with cholesterol. Our findings suggest a direct nonspecific interaction of melatonin may be a mechanism involved in reducing cholesterol associated membrane effects, thus suggesting the existence of a new mechanism of melatonin's action. This may have important biological relevance in addition to the well-known anti-oxidative and receptor binding effects. PMID:24651707

  4. Enzymatic Quantification of Cholesterol and Cholesterol Esters from Silicone Hydrogel Contact Lenses

    PubMed Central

    Pucker, Andrew D.; Thangavelu, Mirunalni

    2010-01-01

    Purpose. The purpose of this work was to develop an enzymatic method of quantification of cholesterol and cholesterol esters derived from contact lenses, both in vitro and ex vivo. Methods. Lotrafilcon B (O2 Optix; CIBA Vision, Inc., Duluth, GA) and galyfilcon A (Acuvue Advance; Vistakon, Inc., Jacksonville, FL) silicone hydrogel contact lenses were independently incubated in cholesterol oleate solutions varying in concentrations. After incubation, the lenses were removed and underwent two separate 2:1 chloroform-methanol extractions. After in vitro studies, 10 human subjects wore both lotrafilcon B and galyfilcon A contact lenses for 7 days. The lenses also underwent two separate 2:1 chloroform-methanol extractions. All in vitro and ex vivo samples were quantified with a cholesterol esterase enzymatic reaction. Results. Calibration curves from quantifications of in vitro contact lens samples soaked in successively decreasing concentrations of cholesterol oleate yielded coefficients of determination (R2) of 0.99 (lotrafilcon B) and 0.97 (galyfilcon A). For in vitro contact lens samples, galyfilcon A was associated with an average cholesterol oleate extraction of 39.85 ± 48.65 μg/lens, whereas lotrafilcon B was associated with 5.86 ± 3.36 μg/lens (P = 0.05) across both extractions and all incubation concentrations. For ex vivo contact lens samples, there was significantly more cholesterol and cholesterol esters deposited on galyfilcon A (5.77 ± 1.87 μg/lens) than on lotrafilcon B (2.03 ± 1.62 μg/lens; P = 0.0005). Conclusions. This is an efficient and simple method of quantifying total cholesterol extracted from silicone hydrogel contact lenses and, potentially, the meibum and/or tear film. Certain silicone hydrogel materials demonstrate more affinity for cholesterol and its esters than do others. PMID:20089871

  5. Parallel digital forensics infrastructure.

    SciTech Connect

    Liebrock, Lorie M.; Duggan, David Patrick

    2009-10-01

    This report documents the architecture and implementation of a Parallel Digital Forensics infrastructure. This infrastructure is necessary for supporting the design, implementation, and testing of new classes of parallel digital forensics tools. Digital Forensics has become extremely difficult with data sets of one terabyte and larger. The only way to overcome the processing time of these large sets is to identify and develop new parallel algorithms for performing the analysis. To support algorithm research, a flexible base infrastructure is required. A candidate architecture for this base infrastructure was designed, instantiated, and tested by this project, in collaboration with New Mexico Tech. Previous infrastructures were not designed and built specifically for the development and testing of parallel algorithms. With the size of forensics data sets only expected to increase significantly, this type of infrastructure support is necessary for continued research in parallel digital forensics. This report documents the implementation of the parallel digital forensics (PDF) infrastructure architecture and implementation.

  6. Cholesterol masks membrane glycosphingolipid tumor-associated antigens to reduce their immunodetection in human cancer biopsies.

    PubMed

    Novak, Anton; Binnington, Beth; Ngan, Bo; Chadwick, Karen; Fleshner, Neil; Lingwood, Clifford A

    2013-11-01

    Glycosphingolipids (GSLs) are neoplastic and normal/cancer stem cell markers and GSL/cholesterol-containing membrane rafts are increased in cancer cell plasma membranes. We define a novel means by which cancer cells can restrict tumor-associated GSL immunoreactivity. The GSL-cholesterol complex reorients GSL carbohydrate to a membrane parallel, rather than perpendicular conformation, largely unavailable for antibody recognition. Methyl-β-cyclodextrin cholesterol extraction of all primary human tumor frozen sections tested (ovarian, testicular, neuroblastoma, prostate, breast, colon, pheochromocytoma and ganglioneuroma), unmasked previously "invisible" membrane GSLs for immunodetection. In ovarian carcinoma, globotriaosyl ceramide (Gb3), the GSL receptor for the antineoplastic Escherichia coli-derived verotoxin, was increased throughout the tumor. In colon carcinoma, Gb3 detection was vastly increased within the neovasculature and perivascular stroma. In tumors considered Gb3 negative (neuroblastoma, Leydig testicular tumor and pheochromocytoma), neovascular Gb3 was unmasked. Tumor-associated GSL stage-specific embryonic antigen (SSEA)-1, SSEA-3, SSEA-4 and globoH were unmasked according to tumor: SSEA-1 in prostate/colon; SSEA-3 in prostate; SSEA-4 in pheochromocytoma/some colon tumors; globoH in prostate/some colon tumors. In colon, anti-SSEA-1 was tumor cell specific. Within the GSL-cholesterol complex, filipin-cholesterol binding was also reduced. These results may relate to the ill-defined benefit of statins on cancer prognosis, for example, prostate carcinoma. We found novel anti-tumor GSL antibodies circulating in 3/5 statin-treated, but not untreated, prostate cancer patients. Lowering tumor membrane cholesterol may permit immune recognition of otherwise unavailable tumor-associated GSL carbohydrate, for more effective immunosurveillance and active/passive immunotherapy. Our results show standard immunodetection of tumor GSLs significantly under assesses

  7. CHOBIMALT: A Cholesterol-Based Detergent†

    PubMed Central

    Howell, Stanley C.; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M.; Sanders, Charles R.

    2010-01-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins, but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3–4μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210 ± 30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1. PMID:20919740

  8. CHOBIMALT: a cholesterol-based detergent.

    PubMed

    Howell, Stanley C; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M; Sanders, Charles R

    2010-11-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems, a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3−4 μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210±30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1.

  9. PCLIPS: Parallel CLIPS

    NASA Technical Reports Server (NTRS)

    Hall, Lawrence O.; Bennett, Bonnie H.; Tello, Ivan

    1994-01-01

    A parallel version of CLIPS 5.1 has been developed to run on Intel Hypercubes. The user interface is the same as that for CLIPS with some added commands to allow for parallel calls. A complete version of CLIPS runs on each node of the hypercube. The system has been instrumented to display the time spent in the match, recognize, and act cycles on each node. Only rule-level parallelism is supported. Parallel commands enable the assertion and retraction of facts to/from remote nodes working memory. Parallel CLIPS was used to implement a knowledge-based command, control, communications, and intelligence (C(sup 3)I) system to demonstrate the fusion of high-level, disparate sources. We discuss the nature of the information fusion problem, our approach, and implementation. Parallel CLIPS has also be used to run several benchmark parallel knowledge bases such as one to set up a cafeteria. Results show from running Parallel CLIPS with parallel knowledge base partitions indicate that significant speed increases, including superlinear in some cases, are possible.

  10. Parallel MR Imaging

    PubMed Central

    Deshmane, Anagha; Gulani, Vikas; Griswold, Mark A.; Seiberlich, Nicole

    2015-01-01

    Parallel imaging is a robust method for accelerating the acquisition of magnetic resonance imaging (MRI) data, and has made possible many new applications of MR imaging. Parallel imaging works by acquiring a reduced amount of k-space data with an array of receiver coils. These undersampled data can be acquired more quickly, but the undersampling leads to aliased images. One of several parallel imaging algorithms can then be used to reconstruct artifact-free images from either the aliased images (SENSE-type reconstruction) or from the under-sampled data (GRAPPA-type reconstruction). The advantages of parallel imaging in a clinical setting include faster image acquisition, which can be used, for instance, to shorten breath-hold times resulting in fewer motion-corrupted examinations. In this article the basic concepts behind parallel imaging are introduced. The relationship between undersampling and aliasing is discussed and two commonly used parallel imaging methods, SENSE and GRAPPA, are explained in detail. Examples of artifacts arising from parallel imaging are shown and ways to detect and mitigate these artifacts are described. Finally, several current applications of parallel imaging are presented and recent advancements and promising research in parallel imaging are briefly reviewed. PMID:22696125

  11. Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

    NASA Astrophysics Data System (ADS)

    Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

  12. Cholesterol binding by the bacterial type III translocon is essential for virulence effector delivery into mammalian cells.

    PubMed

    Hayward, Richard D; Cain, Robert J; McGhie, Emma J; Phillips, Neil; Garner, Matthew J; Koronakis, Vassilis

    2005-05-01

    A ubiquitous early step in infection of man and animals by enteric bacterial pathogens like Salmonella, Shigella and enteropathogenic Escherichia coli (EPEC) is the translocation of virulence effector proteins into mammalian cells via specialized type III secretion systems (TTSSs). Translocated effectors subvert the host cytoskeleton and stimulate signalling to promote bacterial internalization or survival. Target cell plasma membrane cholesterol is central to pathogen-host cross-talk, but the precise nature of its critical contribution remains unknown. Using in vitro cholesterol-binding assays, we demonstrate that Salmonella (SipB) and Shigella (IpaB) TTSS translocon components bind cholesterol with high affinity. Direct visualization of cell-associated fluorescently labelled SipB and parallel immunogold transmission electron microscopy revealed that cholesterol levels limit both the amount and distribution of plasma membrane-integrated translocon. Correspondingly, cholesterol depletion blocked effector translocation into cultured mammalian cells by not only the related Salmonella and Shigella TTSSs, but also the more divergent EPEC system. The data reveal that cholesterol-dependent association of the bacterial TTSS translocon with the target cell plasma membrane is essential for translocon activation and effector delivery into mammalian cells.

  13. X-ray diffraction studies of lipid phase transitions in cholesterol-rich membranes at sub-zero temperatures.

    PubMed

    Finean, J B; Hutchinson, A L

    1988-01-01

    In X-ray diffraction studies of hydrated (greater than 60%) cholesterol/dioleoylphosphatidylcholine mixtures the lipid packing band showed an abrupt transition from liquid crystal-type to gel-type position and definition at a temperature which decreased progressively to almost -50 degrees C as the proportion of cholesterol was increased to a saturation level of about 50 mol%. Plots of transition temperature against composition (mol% cholesterol) and of peak position against composition provided evidence of a significant change in phospholipid configuration at about 20 mol% cholesterol. However, the data overall suggested a uniform dispersion of the cholesterol molecules in the phospholipid bilayer at all concentrations up to the saturation point. Parallel studies of hydrated lipid extract of erythrocyte membranes and of several cholesterol-rich membrane preparations showed a similar overall change from liquid crystal-type packing at +20 degrees C to a gel-type packing at -30 degrees C to -40 degrees C but without displaying a defined transition temperature.

  14. [Basic mechanisms: absorption and excretion of cholesterol and other sterols].

    PubMed

    Cofan Pujol, Montserrat

    2014-01-01

    Cholesterol is of vital importance for vertebrate cell membrane structure and function. It is obvious that adequate regulation of cholesterol homeostasis is essential. Hypercholesterolemia promotes atherosclerosis and thereby represents a major risk factor for cardiovascular disease. The liver has been considered the major site of control in maintenance of cholesterol homeostasis. The liver facilitates clearance of (very) low density lipoprotein particles and cholesterol-containing chylomicron remnants, synthesizes cholesterol, synthesizes and secretes (nascent) high density lipoprotein particles, secretes cholesterol and bile salts to bile, and is involved in reverse cholesterol transport. In recent years, however, the importance of the intestine in many aspects of cholesterol physiology is increasingly recognized. It has become apparent that direct secretion of cholesterol from the blood compartment into the intestine, or transintestinal cholesterol excretion, plays a major role in disposal of cholesterol via the feces. This review will discuss current knowledge on the physiology of cholesterol homeostasis, with emphasis on cholesterol absorption, cholesterol synthesis and fecal excretion, and therapeutic options for hypercholesterolemia. PMID:24461630

  15. [Basic mechanisms: absorption and excretion of cholesterol and other sterols].

    PubMed

    Cofan Pujol, Montserrat

    2014-01-01

    Cholesterol is of vital importance for vertebrate cell membrane structure and function. It is obvious that adequate regulation of cholesterol homeostasis is essential. Hypercholesterolemia promotes atherosclerosis and thereby represents a major risk factor for cardiovascular disease. The liver has been considered the major site of control in maintenance of cholesterol homeostasis. The liver facilitates clearance of (very) low density lipoprotein particles and cholesterol-containing chylomicron remnants, synthesizes cholesterol, synthesizes and secretes (nascent) high density lipoprotein particles, secretes cholesterol and bile salts to bile, and is involved in reverse cholesterol transport. In recent years, however, the importance of the intestine in many aspects of cholesterol physiology is increasingly recognized. It has become apparent that direct secretion of cholesterol from the blood compartment into the intestine, or transintestinal cholesterol excretion, plays a major role in disposal of cholesterol via the feces. This review will discuss current knowledge on the physiology of cholesterol homeostasis, with emphasis on cholesterol absorption, cholesterol synthesis and fecal excretion, and therapeutic options for hypercholesterolemia.

  16. Polysialylation controls dendritic cell trafficking by regulating chemokine recognition.

    PubMed

    Kiermaier, Eva; Moussion, Christine; Veldkamp, Christopher T; Gerardy-Schahn, Rita; de Vries, Ingrid; Williams, Larry G; Chaffee, Gary R; Phillips, Andrew J; Freiberger, Friedrich; Imre, Richard; Taleski, Deni; Payne, Richard J; Braun, Asolina; Förster, Reinhold; Mechtler, Karl; Mühlenhoff, Martina; Volkman, Brian F; Sixt, Michael

    2016-01-01

    The addition of polysialic acid to N- and/or O-linked glycans, referred to as polysialylation, is a rare posttranslational modification that is mainly known to control the developmental plasticity of the nervous system. Here we show that CCR7, the central chemokine receptor controlling immune cell trafficking to secondary lymphatic organs, carries polysialic acid. This modification is essential for the recognition of the CCR7 ligand CCL21. As a consequence, dendritic cell trafficking is abrogated in polysialyltransferase-deficient mice, manifesting as disturbed lymph node homeostasis and unresponsiveness to inflammatory stimuli. Structure-function analysis of chemokine-receptor interactions reveals that CCL21 adopts an autoinhibited conformation, which is released upon interaction with polysialic acid. Thus, we describe a glycosylation-mediated immune cell trafficking disorder and its mechanistic basis. PMID:26657283

  17. Effects of Membrane Trafficking on Signaling by Receptor Tyrosine Kinases

    PubMed Central

    Miaczynska, Marta

    2013-01-01

    The intracellular trafficking machinery contributes to the spatial and temporal control of signaling by receptor tyrosine kinases (RTKs). The primary role in this process is played by endocytic trafficking, which regulates the localization of RTKs and their downstream effectors, as well as the duration and the extent of their activity. The key regulatory points along the endocytic pathway are internalization of RTKs from the plasma membrane, their sorting to degradation or recycling, and their residence in various endosomal compartments. Here I will review factors and mechanisms that modulate RTK signaling by (1) affecting receptor internalization, (2) regulating the balance between degradation and recycling of RTK, and (3) compartmentalization of signals in endosomes and other organelles. Cumulatively, these mechanisms illustrate a multilayered control of RTK signaling exerted by the trafficking machinery. PMID:24186066

  18. Monitoring receptor trafficking following retromer and WASH deregulation.

    PubMed

    Osborne, Douglas G; Phillips-Krawczak, Christine A; Billadeau, Daniel D

    2015-01-01

    Cell surface receptors that have been internalized and enter the endocytic pathway have multiple fates including entrance into the multivesicular body pathway on their way to lysosomal degradation, recycling back to the cell surface, or retrograde trafficking out of the endolysosomal system back to the Golgi apparatus. Two ubiquitously expressed protein complexes, WASH and the endosomal coat complex retromer, function together to play a central role in directing the fate of receptors into the latter two pathways. In this chapter, we describe fluorescent- and flow cytometry-based methods for analyzing the recycling and retrograde trafficking of two receptors, α5β1 and CI-M6PR, whose intracellular fates are regulated by WASH and retromer activity. The guidelines presented in this chapter can be applied to the analysis of any cell surface or intracellular membrane protein to determine the impact of WASH or retromer deregulation on its intracellular trafficking route. PMID:26360036

  19. Roles of membrane trafficking in plant cell wall dynamics

    PubMed Central

    Ebine, Kazuo; Ueda, Takashi

    2015-01-01

    The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transport of the cell wall components and proteins that are involved in cell wall-related events could be specialized for each cell type, i.e., the machinery for cell wall biogenesis, modification, and maintenance could be transported via different trafficking pathways. In this review, we summarize the recent progress in the current understanding of the roles and mechanisms of membrane trafficking in plant cells and focus on the biogenesis and regulation of the cell wall. PMID:26539200

  20. Subversion of Retrograde Trafficking by Translocated Pathogen Effectors.

    PubMed

    Personnic, Nicolas; Bärlocher, Kevin; Finsel, Ivo; Hilbi, Hubert

    2016-06-01

    Intracellular bacterial pathogens subvert the endocytic bactericidal pathway to form specific replication-permissive compartments termed pathogen vacuoles or inclusions. To this end, the pathogens employ type III or type IV secretion systems, which translocate dozens, if not hundreds, of different effector proteins into their host cells, where they manipulate vesicle trafficking and signaling pathways in favor of the intruders. While the distinct cocktail of effectors defines the specific processes by which a pathogen vacuole is formed, the different pathogens commonly target certain vesicle trafficking routes, including the endocytic or secretory pathway. Recently, the retrograde transport pathway from endosomal compartments to the trans-Golgi network emerged as an important route affecting pathogen vacuole formation. Here, we review current insight into the host cell's retrograde trafficking pathway and how vacuolar pathogens of the genera Legionella, Coxiella, Salmonella, Chlamydia, and Simkania employ mechanistically distinct strategies to subvert this pathway, thus promoting intracellular survival and replication. PMID:26924068

  1. Social world of organ transplantation, trafficking, and policies.

    PubMed

    Yousaf, Farhan Navid; Purkayastha, Bandana

    2016-05-01

    Although success of organ transplants reflects advances in medical procedures, the success has generated debates about the ethical standards and policies that govern transplants, especially the acquisition of organs for transplants. We focus on laws, policies, and organ trafficking to highlight the interdisciplinary perspectives that can shape our understanding of transplantation as a social phenomenon. We discuss international policies and country-specific legislation from Pakistan to point to gaps and their implications for protecting vulnerable people who are exploited for organ removal. International collaboration and the legal framework need to be strengthened to fight the menace globally and to deal with the cases of organ trafficking within the legal ambit of human trafficking so that the rights of victims are upheld by states, justice systems, and ultimately medical establishments and practitioners. PMID:26841906

  2. Genome-Wide Analysis of Sterol-Lipid Storage and Trafficking in Saccharomyces cerevisiae▿

    PubMed Central

    Fei, Weihua; Alfaro, Gabriel; Muthusamy, Baby-Periyanayaki; Klaassen, Zachary; Graham, Todd R.; Yang, Hongyuan; Beh, Christopher T.

    2008-01-01

    The pandemic of lipid-related disease necessitates a determination of how cholesterol and other lipids are transported and stored within cells. The first step in this determination is the identification of the genes involved in these transport and storage processes. Using genome-wide screens, we identified 56 yeast (Saccharomyces cerevisiae) genes involved in sterol-lipid biosynthesis, intracellular trafficking, and/or neutral-lipid storage. Direct biochemical and cytological examination of mutant cells revealed an unanticipated link between secretory protein glycosylation and triacylglycerol (TAG)/steryl ester (SE) synthesis for the storage of lipids. Together with the analysis of other deletion mutants, these results suggested at least two distinct events for the biogenesis of lipid storage particles: a step affecting neutral-lipid synthesis, generating the lipid core of storage particles, and another step for particle assembly. In addition to the lipid storage mutants, we identified mutations that affect the localization of unesterified sterols, which are normally concentrated in the plasma membrane. These findings implicated phospholipase C and the protein phosphatase Ptc1p in the regulation of sterol distribution within cells. This study identified novel sterol-related genes that define several distinct processes maintaining sterol homeostasis. PMID:18156287

  3. Can cholesterol be used to distinguish pleural exudates from transudates? evidence from a bivariate meta-analysis

    PubMed Central

    2014-01-01

    Background Many studies have investigated whether pleural cholesterol levels can aid in diagnosis of pleural exudates, and the results have varied considerably. To gain a more reliable answer to this question, we meta-analyzed the literature on using pleural cholesterol or the ratio of cholesterol in pleural fluid to cholesterol in serum (P/S cholesterol ratio) as diagnostic tests to help identify pleural exudates. Methods Literature databases were systematically searched for studies examining accuracy of pleural cholesterol or P/S cholesterol ratios for diagnosing pleural exudates. Data on sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR) were pooled using bivariate-effects models. Summary receiver operating characteristic (SROC) curves and area under the curve (AUC) were used to summarize overall test performance. Results Our meta-analysis included up to 20 studies involving 3,496 subjects. Summary estimates for pleural cholesterol in the diagnosis of pleural exudates were as follows: sensitivity, 0.88 (95%CI 0.84 to 0.92); specificity, 0.96 (95% CI 0.92 to 0.98); PLR, 20.31 (95% CI 11.21 to 36.78); NLR, 0.12 (95% CI 0.09 to 0.17); DOR, 167.06 (95% CI 76.79 to 363.95); and AUC 0.97 (95% CI 0.95 to 0.98). The corresponding summary performance estimates for using the P/S cholesterol ratio were as follows: sensitivity, 0.94 (95% CI 0.92 to 0.96); specificity, 0.87 (95% CI 0.83 to 0.91); PLR 7.46 (95% CI, 5.47 to 10.19); NLR, 0.07 (95% CI 0.05 to 0.10); DOR, 107.74 (95% CI 60.91 to 190.60); and AUC 0.97 (95% CI 0.95 to 0.98). Conclusions Both pleural cholesterol level and the P/S cholesterol ratio are helpful for the diagnosis of pleural exudates. Nevertheless, the results of pleural cholesterol assays should be interpreted in parallel with the results of traditional tests and clinical information. PMID:24731290

  4. Cholesterol granuloma of the breast mimicking malignancy

    PubMed Central

    Khan, Roobina; Narula, Varsha; Jain, Anshu; Maheshwari, Veena

    2013-01-01

    Cholesterol granuloma of the breast is an unusual non-neoplastic condition which frequently resembles malignancy clinically as well as radiologically. We herein report a case of a 28-year-old woman who presented with a lump in the upper outer quadrant of right breast. Physical examination and ultrasonography strongly suggested a carcinomatous lesion, but histopathological examination confirmed the diagnosis to be cholestrol granulomas. This article highlights the perplexing clinical presentation of cholesterol granulomas and affirms the role of histopathological examination in diagnosing these lesions correctly. PMID:23925685

  5. Biodistribution and Trafficking of Hydrogel Nanoparticles in Adult Mosquitoes

    PubMed Central

    Paquette, Cynthia C. H.; Phanse, Yashdeep; Perry, Jillian L.; Sanchez-Vargas, Irma; Airs, Paul M.; Dunphy, Brendan M.; Xu, Jing; Carlson, Jonathan O.; Luft, J. Christopher; DeSimone, Joseph M.; Bartholomay, Lyric C.; Beaty, Barry J.

    2015-01-01

    Background Nanotechnology offers great potential for molecular genetic investigations and potential control of medically important arthropods. Major advances have been made in mammalian systems to define nanoparticle (NP) characteristics that condition trafficking and biodistribution of NPs in the host. Such information is critical for effective delivery of therapeutics and molecules to cells and organs, but little is known about biodistribution of NPs in mosquitoes. Methodology/Principal Findings PRINT technology was used to construct a library of fluorescently labeled hydrogel NPs of defined size, shape, and surface charge. The biodistribution (organ, tissue, and cell tropisms and trafficking kinetics) of positively and negatively charged 200 nm x 200 nm, 80 nm x 320 nm, and 80 nm x 5000 nm NPs was determined in adult Anopheles gambiae mosquitoes as a function of the route of challenge (ingestion, injection or contact) using whole body imaging and fluorescence microscopy. Mosquitoes readily ingested NPs in sugar solution. Whole body fluorescence imaging revealed substantial NP accumulation (load) in the alimentary tracts of the adult mosquitoes, with the greatest loads in the diverticula, cardia and foregut. Positively and negatively charged NPs differed in their biodistribution and trafficking. Following oral challenge, negatively charged NPs transited the alimentary tract more rapidly than positively charged NPs. Following contact challenge, negatively charged NPs trafficked more efficiently in alimentary tract tissues. Following parenteral challenge, positively and negatively charged NPs differed in tissue tropisms and trafficking in the hemocoel. Injected NPs were also detected in cardia/foregut, suggesting trafficking of NPs from the hemocoel into the alimentary tract. Conclusions/Significance Herein we have developed a tool box of NPs with the biodistribution and tissue tropism characteristics for gene structure/function studies and for delivery of vector

  6. 3 CFR 9074 - Proclamation 9074 of December 31, 2013. National Slavery and Human Trafficking Prevention Month...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... down on traffickers, charging a record number of perpetrators. We are deploying new technology in the... leaders from every sector of society. Together, we came up with new ideas to fight trafficking at...

  7. Attitudes About Human Trafficking: Individual Differences Related to Belief and Victim Blame.

    PubMed

    Cunningham, Katherine C; Cromer, Lisa DeMarni

    2016-01-01

    Human trafficking is believed to oppress millions of people worldwide. Despite increased media attention and public awareness campaigns in recent years, no empirical research has examined public attitudes about human trafficking. The present study examined gender, sexual trauma history, and attitudes about human trafficking as they related to belief of a sex-trafficking scenario and willingness to blame the victim for the situation. Undergraduate students (N = 409) at a large private university in the Northeastern United States completed measures in which they responded to a vignette portraying sex trafficking in the United States. Participants also reported their personal trauma history and completed a Human Trafficking Myths Scale. Results indicated that gender and human trafficking myth acceptance, but not sexual trauma history, were significantly related to participants' belief of the sex-trafficking scenario and their perception of the victim's responsibility. Potential implications and directions for future research are discussed. PMID:25389189

  8. A model for assessing the risk of human trafficking on a local level

    NASA Astrophysics Data System (ADS)

    Colegrove, Amanda

    Human trafficking is a human rights violation that is difficult to quantify. Models for estimating the number of victims of trafficking presented by previous researchers depend on inconsistent, poor quality data. As an intermediate step to help current efforts by nonprofits to combat human trafficking, this project presents a model that is not dependent on quantitative data specific to human trafficking, but rather profiles the risk of human trafficking at the local level through causative factors. Businesses, indicated by the literature, were weighted based on the presence of characteristics that increase the likelihood of trafficking in persons. The mean risk was calculated by census tract to reveal the multiplicity of risk levels in both rural and urban settings. Results indicate that labor trafficking may be a more diffuse problem in Missouri than sex trafficking. Additionally, spatial patterns of risk remained largely the same regardless of adjustments made to the model.

  9. Attitudes About Human Trafficking: Individual Differences Related to Belief and Victim Blame.

    PubMed

    Cunningham, Katherine C; Cromer, Lisa DeMarni

    2016-01-01

    Human trafficking is believed to oppress millions of people worldwide. Despite increased media attention and public awareness campaigns in recent years, no empirical research has examined public attitudes about human trafficking. The present study examined gender, sexual trauma history, and attitudes about human trafficking as they related to belief of a sex-trafficking scenario and willingness to blame the victim for the situation. Undergraduate students (N = 409) at a large private university in the Northeastern United States completed measures in which they responded to a vignette portraying sex trafficking in the United States. Participants also reported their personal trauma history and completed a Human Trafficking Myths Scale. Results indicated that gender and human trafficking myth acceptance, but not sexual trauma history, were significantly related to participants' belief of the sex-trafficking scenario and their perception of the victim's responsibility. Potential implications and directions for future research are discussed.

  10. Eclipse Parallel Tools Platform

    2005-02-18

    Designing and developing parallel programs is an inherently complex task. Developers must choose from the many parallel architectures and programming paradigms that are available, and face a plethora of tools that are required to execute, debug, and analyze parallel programs i these environments. Few, if any, of these tools provide any degree of integration, or indeed any commonality in their user interfaces at all. This further complicates the parallel developer's task, hampering software engineering practices,more » and ultimately reducing productivity. One consequence of this complexity is that best practice in parallel application development has not advanced to the same degree as more traditional programming methodologies. The result is that there is currently no open-source, industry-strength platform that provides a highly integrated environment specifically designed for parallel application development. Eclipse is a universal tool-hosting platform that is designed to providing a robust, full-featured, commercial-quality, industry platform for the development of highly integrated tools. It provides a wide range of core services for tool integration that allow tool producers to concentrate on their tool technology rather than on platform specific issues. The Eclipse Integrated Development Environment is an open-source project that is supported by over 70 organizations, including IBM, Intel and HP. The Eclipse Parallel Tools Platform (PTP) plug-in extends the Eclipse framwork by providing support for a rich set of parallel programming languages and paradigms, and a core infrastructure for the integration of a wide variety of parallel tools. The first version of the PTP is a prototype that only provides minimal functionality for parallel tool integration of a wide variety of parallel tools. The first version of the PTP is a prototype that only provides minimal functionality for parallel tool integration, support for a small number of parallel architectures

  11. Implementation of cellulomonas cholesterol oxidase for total serum cholesterol determination by the endpoint method.

    PubMed

    Srisawasdi, Pornpen; Chaichanajarernkul, Upsorn; Teerakranjana, Narumon; Kroll, Martin H

    2008-01-01

    Cellulomonas has been shown to be a good source of cholesterol oxidase in addition to Streptomyces for serum cholesterol determination by the endpoint method, inexpensive in cost, and showing excellent performance. For clinical use, we have assessed the reliability of Cellulomonas reagent for cholesterol determination. We constructed the user-defined endpoint methods on three automated analyzers. The analytical performances (linearity, precision, recovery, interference, stability, and comparison with the standardized method) of Cellulomonas cholesterol reagents were evaluated and compared to those of Streptomyces reagents. Linearity (18.1-23.3 mmol/L) and stability of reagents (6-11 weeks) depended on the analyzers being used. The average within-run and between-day % coefficients of variation (CVs) ranged from 1.44 to 2.45 and 1.98 to 2.99, respectively, and were within National Cholesterol Education Program analytical criteria (cholesterol recovery while lipemia generated a positive interference with all methods. Cellulomonas enzyme is analytically reliable when used for serum cholesterol determination by the endpoint method. Its analytical performance is equivalent to Streptomyces enzymes and meets the analytical goals. It has an advantage over the other enzymes in that it does not ship in the frozen state.

  12. A new framework for reverse cholesterol transport: Non-biliary contributions to reverse cholesterol transport

    PubMed Central

    Temel, Ryan E; Brown, J Mark

    2010-01-01

    Reduction of low-density lipoprotein-cholesterol through statin therapy has only modestly decreased coronary heart disease (CHD)-associated mortality in developed countries, which has prompted the search for alternative therapeutic strategies for CHD. Major efforts are now focused on therapies that augment high-density lipoprotein (HDL)-mediated reverse cholesterol transport (RCT), and ultimately increase the fecal disposal of cholesterol. The process of RCT has long been thought to simply involve HDL-mediated delivery of peripheral cholesterol to the liver for biliary excretion out of the body. However, recent studies have revealed a novel pathway for RCT that does not rely on biliary secretion. This non-biliary pathway rather involves the direct excretion of cholesterol by the proximal small intestine. Compared to RCT therapies that augment biliary sterol loss, modulation of non-biliary fecal sterol loss through the intestine is a much more attractive therapeutic strategy, given that excessive biliary cholesterol secretion can promote gallstone formation. However, we are at an early stage in understanding the molecular mechanisms regulating the non-biliary pathway for RCT, and much additional work is required in order to effectively target this pathway for CHD prevention. The purpose of this review is to discuss our current understanding of biliary and non-biliary contributions to RCT with particular emphasis on the possibility of targeting the intestine as an inducible cholesterol secretory organ. PMID:21157970

  13. Lysosomal membrane glycoproteins bind cholesterol and contribute to lysosomal cholesterol export

    PubMed Central

    Li, Jian; Pfeffer, Suzanne R

    2016-01-01

    LAMP1 and LAMP2 proteins are highly abundant, ubiquitous, mammalian proteins that line the lysosome limiting membrane, and protect it from lysosomal hydrolase action. LAMP2 deficiency causes Danon’s disease, an X-linked hypertrophic cardiomyopathy. LAMP2 is needed for chaperone-mediated autophagy, and its expression improves tissue function in models of aging. We show here that human LAMP1 and LAMP2 bind cholesterol in a manner that buries the cholesterol 3β-hydroxyl group; they also bind tightly to NPC1 and NPC2 proteins that export cholesterol from lysosomes. Quantitation of cellular LAMP2 and NPC1 protein levels suggest that LAMP proteins represent a significant cholesterol binding site at the lysosome limiting membrane, and may signal cholesterol availability. Functional rescue experiments show that the ability of human LAMP2 to facilitate cholesterol export from lysosomes relies on its ability to bind cholesterol directly. DOI: http://dx.doi.org/10.7554/eLife.21635.001 PMID:27664420

  14. Trafficking in persons and victim health in Australia.

    PubMed

    Schloenhardt, Andreas; Klug, Benjamin

    2011-12-01

    This article explores the health problems experienced by victims of trafficking in persons in Australia and analyses the domestic support schemes established to assist these victims. It focuses specifically on the health of adult, female victims who constitute the majority of identified victims, and who are the principal recipients of government support services. Domestic experiences and support schemes are reviewed in the light of international law and best practice guidelines. Recommendations are made to improve the health services available to victims of trafficking in persons in Australia. PMID:22320010

  15. Organ economy: organ trafficking in Moldova and Israel.

    PubMed

    Lundin, Susanne

    2012-02-01

    Organ trafficking is an illegal means of meeting the shortage of transplants. The activity flourishes for several interacting reasons, such as medical needs, poverty and criminality. Other factors are fundamental conceptual structures such as the dream of the regenerative body as well as the view of the body as an object of utility and an object of value. The article aims to go behind the normative discussions that usually surround organ trafficking. Why this is happening, and what the societal consequences are, is examined through ethnographic fieldwork. The focus is on the shadow economies that govern existence and in which people, goods, weapons, money, bodies, etc. constitute components of the global market.

  16. Trafficking regulation of proteins in Alzheimer’s disease

    PubMed Central

    2014-01-01

    The β-amyloid (Aβ) peptide has been postulated to be a key determinant in the pathogenesis of Alzheimer’s disease (AD). Aβ is produced through sequential cleavage of the β-amyloid precursor protein (APP) by β- and γ-secretases. APP and relevant secretases are transmembrane proteins and traffic through the secretory pathway in a highly regulated fashion. Perturbation of their intracellular trafficking may affect dynamic interactions among these proteins, thus altering Aβ generation and accelerating disease pathogenesis. Herein, we review recent progress elucidating the regulation of intracellular trafficking of these essential protein components in AD. PMID:24410826

  17. A human rights approach to human trafficking for organ removal.

    PubMed

    Budiani-Saberi, Debra; Columb, Seán

    2013-11-01

    Human trafficking for organ removal (HTOR) should not be reduced to a problem of supply and demand of organs for transplantation, a problem of organized crime and criminal justice, or a problem of voiceless, abandoned victims. Rather, HTOR is at once an egregious human rights abuse and a form of human trafficking. As such, it demands a human-rights based approach in analysis and response to this problem, placing the victim at the center of initiatives to combat this phenomenon. Such an approach requires us to consider how various measures impact or disregard victims/potential victims of HTOR and gives us tools to better advocate their interests, rights and freedoms.

  18. Annexin A6 and Late Endosomal Cholesterol Modulate Integrin Recycling and Cell Migration.

    PubMed

    García-Melero, Ana; Reverter, Meritxell; Hoque, Monira; Meneses-Salas, Elsa; Koese, Meryem; Conway, James R W; Johnsen, Camilla H; Alvarez-Guaita, Anna; Morales-Paytuvi, Frederic; Elmaghrabi, Yasmin A; Pol, Albert; Tebar, Francesc; Murray, Rachael Z; Timpson, Paul; Enrich, Carlos; Grewal, Thomas; Rentero, Carles

    2016-01-15

    Annexins are a family of proteins that bind to phospholipids in a calcium-dependent manner. Earlier studies implicated annexin A6 (AnxA6) to inhibit secretion and participate in the organization of the extracellular matrix. We recently showed that elevated AnxA6 levels significantly reduced secretion of the extracellular matrix protein fibronectin (FN). Because FN is directly linked to the ability of cells to migrate, this prompted us to investigate the role of AnxA6 in cell migration. Up-regulation of AnxA6 in several cell models was associated with reduced cell migration in wound healing, individual cell tracking and three-dimensional migration/invasion assays. The reduced ability of AnxA6-expressing cells to migrate was associated with decreased cell surface expression of αVβ3 and α5β1 integrins, both FN receptors. Mechanistically, we found that elevated AnxA6 levels interfered with syntaxin-6 (Stx6)-dependent recycling of integrins to the cell surface. AnxA6 overexpression caused mislocalization and accumulation of Stx6 and integrins in recycling endosomes, whereas siRNA-mediated AnxA6 knockdown did not modify the trafficking of integrins. Given our recent findings that inhibition of cholesterol export from late endosomes (LEs) inhibits Stx6-dependent integrin recycling and that elevated AnxA6 levels cause LE cholesterol accumulation, we propose that AnxA6 and blockage of LE cholesterol transport are critical for endosomal function required for Stx6-mediated recycling of integrins in cell migration.

  19. Pitavastatin Differentially Modulates MicroRNA-Associated Cholesterol Transport Proteins in Macrophages.

    PubMed

    Zhang, Haijun; Lamon, Brian D; Moran, George; Sun, Tao; Gotto, Antonio M; Hajjar, David P

    2016-01-01

    There is emerging evidence identifying microRNAs (miRNAs) as mediators of statin-induced cholesterol efflux, notably through the ATP-binding cassette transporter A1 (ABCA1) in macrophages. The objective of this study was to assess the impact of an HMG-CoA reductase inhibitor, pitavastatin, on macrophage miRNAs in the presence and absence of oxidized-LDL, a hallmark of a pro-atherogenic milieu. Treatment of human THP-1 cells with pitavastatin prevented the oxLDL-mediated suppression of miR-33a, -33b and -758 mRNA in these cells, an effect which was not uniquely attributable to induction of SREBP2. Induction of ABCA1 mRNA and protein by oxLDL was inhibited (30%) by pitavastatin, while oxLDL or pitavastatin alone significantly induced and repressed ABCA1 expression, respectively. These findings are consistent with previous reports in macrophages. miRNA profiling was also performed using a miRNA array. We identified specific miRNAs which were up-regulated (122) and down-regulated (107) in THP-1 cells treated with oxLDL plus pitavastatin versus oxLDL alone, indicating distinct regulatory networks in these cells. Moreover, several of the differentially expressed miRNAs identified are functionally associated with cholesterol trafficking (six miRNAs in cells treated with oxLDL versus oxLDL plus pitavastatin). Our findings indicate that pitavastatin can differentially modulate miRNA in the presence of oxLDL; and, our results provide evidence that the net effect on cholesterol homeostasis is mediated by a network of miRNAs. PMID:27415822

  20. Pitavastatin Differentially Modulates MicroRNA-Associated Cholesterol Transport Proteins in Macrophages

    PubMed Central

    Moran, George; Sun, Tao; Gotto, Antonio M.; Hajjar, David P.

    2016-01-01

    There is emerging evidence identifying microRNAs (miRNAs) as mediators of statin-induced cholesterol efflux, notably through the ATP-binding cassette transporter A1 (ABCA1) in macrophages. The objective of this study was to assess the impact of an HMG-CoA reductase inhibitor, pitavastatin, on macrophage miRNAs in the presence and absence of oxidized-LDL, a hallmark of a pro-atherogenic milieu. Treatment of human THP-1 cells with pitavastatin prevented the oxLDL-mediated suppression of miR-33a, -33b and -758 mRNA in these cells, an effect which was not uniquely attributable to induction of SREBP2. Induction of ABCA1 mRNA and protein by oxLDL was inhibited (30%) by pitavastatin, while oxLDL or pitavastatin alone significantly induced and repressed ABCA1 expression, respectively. These findings are consistent with previous reports in macrophages. miRNA profiling was also performed using a miRNA array. We identified specific miRNAs which were up-regulated (122) and down-regulated (107) in THP-1 cells treated with oxLDL plus pitavastatin versus oxLDL alone, indicating distinct regulatory networks in these cells. Moreover, several of the differentially expressed miRNAs identified are functionally associated with cholesterol trafficking (six miRNAs in cells treated with oxLDL versus oxLDL plus pitavastatin). Our findings indicate that pitavastatin can differentially modulate miRNA in the presence of oxLDL; and, our results provide evidence that the net effect on cholesterol homeostasis is mediated by a network of miRNAs. PMID:27415822

  1. cDNA cloning of cholesterol 24-hydroxylase, a mediator of cholesterol homeostasis in the brain

    PubMed Central

    Lund, Erik G.; Guileyardo, Joseph M.; Russell, David W.

    1999-01-01

    The turnover of cholesterol in the brain is thought to occur via conversion of excess cholesterol into 24S-hydroxycholesterol, an oxysterol that is readily secreted from the central nervous system into the plasma. To gain molecular insight into this pathway of cholesterol metabolism, we used expression cloning to isolate cDNAs that encode murine and human cholesterol 24-hydroxylases. DNA sequence analysis indicates that both proteins are localized to the endoplasmic reticulum, share 95% identity, and represent a new cytochrome P450 subfamily (CYP46). When transfected into cultured cells, the cDNAs produce an enzymatic activity that converts cholesterol into 24S-hydroxycholesterol, and to a lesser extent, 25-hydroxycholesterol. The cholesterol 24-hydroxylase gene contains 15 exons and is located on human chromosome 14q32.1. Cholesterol 24-hydroxylase is expressed predominantly in the brain as judged by RNA and protein blotting. In situ mRNA hybridization and immunohistochemistry localize the expression of this P450 to neurons in multiple subregions of the brain. The concentrations of 24S-hydroxycholesterol in serum are low in newborn mice, reach a peak between postnatal days 12 and 15, and thereafter decline to baseline levels. In contrast, cholesterol 24-hydroxylase protein is first detected in the brain of mice at birth and continues to accumulate with age. We conclude that the cloned cDNAs encode cholesterol 24-hydroxylases that synthesize oxysterols in neurons of the brain and that secretion of 24S-hydroxycholesterol from this tissue in the mouse is developmentally regulated. PMID:10377398

  2. An amperometric cholesterol biosensor based on epoxy resin membrane bound cholesterol oxidase

    PubMed Central

    Pundir, C.S.; Narang, Jagriti; Chauhan, Nidhi; Sharma, Preety; Sharma, Renu

    2012-01-01

    Background & objectives: The use of epoxy resin membrane as a support for immobilization of enzyme has resulted into improved sensitivity and stability of biosensors for uric acid, ascorbic acid and polyphenols. The present work was aimed to prepare an improved amperometric biosensor for determination of serum cholesterol required in the diagnostics and management of certain pathological conditions. Methods: Epoxy resin membrane with immobilized cholesterol oxidase was mounted on the cleaned platinum (Pt) electrode with a parafilm to construct a working electrode. This working electrode along with Ag/AgCl as reference and Ag wire as an auxiliary electrode were connected through a three terminal electrometer to construct a cholesterol biosensor. Results: The sensor showed optimum response within 25 sec at pH 7.0 and 45°C. The linear working range of biosensor was 1.0 to 8.0 mM cholesterol. Km and Imax for cholesterol were 5.0 mM and 9.09 μA, respectively. The biosensor measured serum cholesterol. The minimum detection limit of the sensor was 1.0 mM. The mean analytical recoveries of added cholesterol in serum (2.84 and 4.13 mM) were 91.4±2.8 and 92.3±3.1 per cent (n=6), respectively. Within and between assay coefficient of variation (CV) were <2 and <4 per cent, respectively. Biosensor had a storage life of 6 months at 4°C. Interpretation & conclusions: The use of epoxy resin membrane as a support for immobilization of cholesterol oxidase has resulted into an improved amperometric cholesterol biosensor. The present biosensor had an advantage over the existing biosensors as it worked at comparatively lower potential. PMID:23168704

  3. Intestinal SR-BI does not impact cholesterol absorption or transintestinal cholesterol efflux in mice.

    PubMed

    Bura, Kanwardeep S; Lord, Caleb; Marshall, Stephanie; McDaniel, Allison; Thomas, Gwyn; Warrier, Manya; Zhang, Jun; Davis, Matthew A; Sawyer, Janet K; Shah, Ramesh; Wilson, Martha D; Dikkers, Arne; Tietge, Uwe J F; Collet, Xavier; Rudel, Lawrence L; Temel, Ryan E; Brown, J Mark

    2013-06-01

    Reverse cholesterol transport (RCT) can proceed through the classic hepatobiliary route or through the nonbiliary transintestinal cholesterol efflux (TICE) pathway. Scavenger receptor class B type I (SR-BI) plays a critical role in the classic hepatobiliary route of RCT. However, the role of SR-BI in TICE has not been studied. To examine the role of intestinal SR-BI in TICE, sterol balance was measured in control mice and mice transgenically overexpressing SR-BI in the proximal small intestine (SR-BI(hApoCIII-ApoAIV-Tg)). SR-BI(hApoCIII-ApoAIV-Tg) mice had significantly lower plasma cholesterol levels compared with wild-type controls, yet SR-BI(hApoCIII-ApoAIV-Tg) mice had normal fractional cholesterol absorption and fecal neutral sterol excretion. Both in the absence or presence of ezetimibe, intestinal SR-BI overexpression had no impact on the amount of cholesterol excreted in the feces. To specifically study effects of intestinal SR-BI on TICE we crossed SR-BI(hApoCIII-ApoAIV-Tg) mice into a mouse model that preferentially utilized the TICE pathway for RCT (Niemann-Pick C1-like 1 liver transgenic), and likewise found no alterations in cholesterol absorption or fecal sterol excretion. Finally, mice lacking SR-BI in all tissues also exhibited normal cholesterol absorption and fecal cholesterol disposal. Collectively, these results suggest that SR-BI is not rate limiting for intestinal cholesterol absorption or for fecal neutral sterol loss through the TICE pathway.

  4. Sterol Carrier Protein 2, a Critical Host Factor for Dengue Virus Infection, Alters the Cholesterol Distribution in Mosquito Aag2 Cells.

    PubMed

    Fu, Qiang; Inankur, Bahar; Yin, John; Striker, Rob; Lan, Que

    2015-09-01

    Host factors that enable dengue virus (DENV) to propagate in the mosquito host cells are unclear. It is known that cellular cholesterol plays an important role in the life cycle of DENV in human host cells but unknown if the lipid requirements differ for mosquito versus mammalian. In mosquito Aedes aegypti, sterol carrier protein 2 (SCP-2) is critical for cellular cholesterol homeostasis. In this study, we identified SCP-2 as a critical host factor for DENV production in mosquito Aag2 cells. Treatment with a small molecule commonly referred to as SCPI-1, (N-(4-{[4-(3,4-dichlorophenyl)-1,3-thiazol-2-yl]amino}phenyl)acetamide hydrobromide, a known inhibitor of SCP-2, or knockdown of SCP-2 dramatically repressed the virus production in mosquito but not mammalian cells. We showed that the intracellular cholesterol distribution in mosquito cells was altered by SCP-2 inhibitor treatment, suggesting that SCP-2-mediated cholesterol trafficking pathway is important for DENV viral production. A comparison of the effect of SCP-2 on mosquito and human cells suggests that SCPI-1 treatment decreases cholesterol in both cell lines, but this decrease in cholesterol only leads to a decline in viral titer in mosquito host cells, perhaps, owing to a more drastic effect on perinuclear cholesterol storages in mosquito cells that was absent in human cells. SCP-2 had no inhibitory effect on another enveloped RNA virus grown in mosquito cells, suggesting that SCP-2 does not have a generalized anti-cellular or antiviral effect. Our cell culture results imply that SCP-2 may play a limiting role in mosquito-dengue vector competence.

  5. Sex trafficking in Nepal: a review of intervention and prevention programs.

    PubMed

    Kaufman, Michelle R; Crawford, Mary

    2011-05-01

    Trafficking of girls and women for the purpose of sexual exploitation is a problem worldwide, particularly in South Asia. This review focuses on Nepal-to-India sex trafficking with an examination of current anti-trafficking intervention and prevention programs. The activities of both governmental agencies and nongovernment organizations are described and critically analyzed. Suggestions for evaluating and improving interventions, and thereby reducing the trafficking of girls and women, are discussed. PMID:21502114

  6. Parallel Lisp simulator

    SciTech Connect

    Weening, J.S.

    1988-05-01

    CSIM is a simulator for parallel Lisp, based on a continuation passing interpreter. It models a shared-memory multiprocessor executing programs written in Common Lisp, extended with several primitives for creating and controlling processes. This paper describes the structure of the simulator, measures its performance, and gives an example of its use with a parallel Lisp program.

  7. Insoluble carob fiber rich in polyphenols lowers total and LDL cholesterol in hypercholesterolemic sujects.

    PubMed

    Ruiz-Roso, Baltasar; Quintela, José C; de la Fuente, Ester; Haya, Javier; Pérez-Olleros, Lourdes

    2010-03-01

    Recently, polyphenols have been found to affect blood lipids in animals in a similar manner as soluble dietary fibre. The aim was to assess whether an insoluble dietary fiber very rich in polyphenols has a beneficial effect on serum lipids in humans. In a double-blind randomized placebo-controlled clinical study with parallel arms, 88 volunteers with hypercholesterolemia were randomly assigned to consume daily either, fiber with insoluble 84% polyphenols 4 g twice a day (n = 43) or placebo (n = 45). Serum total, LDL and HDL cholesterol and triglycerides were assessed at baseline and after 4 weeks. The insoluble polyphenols consumption reduced the total cholesterol by 17.8 +/- 6.1% (p < 0.05), LDL cholesterol by 22.5 +/- 8.9% (p < 0.001), LDL: HDL cholesterol ratio by 26.2 +/- 14.3% (p < 0.001) and triglycerides by 16.3 +/- 23.4% (p < 0.05) at the end of the study compared with baseline. No significant differences were found during the study time in the placebo group for the lipid profile. The consumption of fiber very rich in insoluble polyphenols shows beneficial effects on human blood lipid profile and may be effective in prevention and treatment of hyperlipemia.

  8. Curcumin promotes cholesterol efflux from adipocytes related to PPARgamma-LXRalpha-ABCA1 passway.

    PubMed

    Dong, Shao-zhuang; Zhao, Shui-ping; Wu, Zhi-hong; Yang, Jun; Xie, Xiang-zhu; Yu, Bi-lian; Nie, Sai

    2011-12-01

    Curcumin affects the functions of adipocytes. But it is not known whether curcumin has some effect on the cholesterol efflux process of adipocytes. Rabbit subcutaneous adipocytes were incubated with 5, 10 and 20 μg/ml curcumin for 24 h. The cholesterol efflux onto apoAI was assessed, and the peroxisome proliferators-activated receptor (PPAR) γ, liver X receptor (LXR) α and ATP-binding cassette transporter A1 (ABCA1) mRNA expression in adipocytes were quantified by reverse-transcription polymerase chain reaction (RT-PCR). Curcumin increased the cholesterol efflux from adipocytes in dose-dependent manner. The increased expression of PPARγ, LXRα and ABCA1 caused by curcumin were parallel. When the adipocytes were pre-treated by GW9662, the increased expression of PPARγ induced by curcumin was partially prevented, subsequent to the down-regulation of LXRα and ABCA1. Curcumin can affect the cholesterol efflux from adipocytes by regulating the PPARγ-LXR-ABCA1 passway.

  9. Parallel computing works

    SciTech Connect

    Not Available

    1991-10-23

    An account of the Caltech Concurrent Computation Program (C{sup 3}P), a five year project that focused on answering the question: Can parallel computers be used to do large-scale scientific computations '' As the title indicates, the question is answered in the affirmative, by implementing numerous scientific applications on real parallel computers and doing computations that produced new scientific results. In the process of doing so, C{sup 3}P helped design and build several new computers, designed and implemented basic system software, developed algorithms for frequently used mathematical computations on massively parallel machines, devised performance models and measured the performance of many computers, and created a high performance computing facility based exclusively on parallel computers. While the initial focus of C{sup 3}P was the hypercube architecture developed by C. Seitz, many of the methods developed and lessons learned have been applied successfully on other massively parallel architectures.

  10. Totally parallel multilevel algorithms

    NASA Technical Reports Server (NTRS)

    Frederickson, Paul O.

    1988-01-01

    Four totally parallel algorithms for the solution of a sparse linear system have common characteristics which become quite apparent when they are implemented on a highly parallel hypercube such as the CM2. These four algorithms are Parallel Superconvergent Multigrid (PSMG) of Frederickson and McBryan, Robust Multigrid (RMG) of Hackbusch, the FFT based Spectral Algorithm, and Parallel Cyclic Reduction. In fact, all four can be formulated as particular cases of the same totally parallel multilevel algorithm, which are referred to as TPMA. In certain cases the spectral radius of TPMA is zero, and it is recognized to be a direct algorithm. In many other cases the spectral radius, although not zero, is small enough that a single iteration per timestep keeps the local error within the required tolerance.

  11. Massively parallel mathematical sieves

    SciTech Connect

    Montry, G.R.

    1989-01-01

    The Sieve of Eratosthenes is a well-known algorithm for finding all prime numbers in a given subset of integers. A parallel version of the Sieve is described that produces computational speedups over 800 on a hypercube with 1,024 processing elements for problems of fixed size. Computational speedups as high as 980 are achieved when the problem size per processor is fixed. The method of parallelization generalizes to other sieves and will be efficient on any ensemble architecture. We investigate two highly parallel sieves using scattered decomposition and compare their performance on a hypercube multiprocessor. A comparison of different parallelization techniques for the sieve illustrates the trade-offs necessary in the design and implementation of massively parallel algorithms for large ensemble computers.

  12. Susceptibility of outer hair cells to cholesterol chelator 2-hydroxypropyl-β-cyclodextrine is prestin-dependent

    PubMed Central

    Takahashi, Satoe; Homma, Kazuaki; Zhou, Yingjie; Nishimura, Shinichi; Duan, Chongwen; Chen, Jessie; Ahmad, Aisha; Cheatham, Mary Ann; Zheng, Jing

    2016-01-01

    Niemann-Pick type C1 disease (NPC1) is a fatal genetic disorder caused by impaired intracellular cholesterol trafficking. Recent studies reported ototoxicity of 2-hydroxypropyl- β-cyclodextrin (HPβCD), a cholesterol chelator and the only promising treatment for NPC1. Because outer hair cells (OHCs) are the only cochlear cells affected by HPβCD, we investigated whether prestin, an OHC-specific motor protein, might be involved. Single, high-dose administration of HPβCD resulted in OHC death in prestin wildtype (WT) mice whereas OHCs were largely spared in prestin knockout (KO) mice in the basal region, implicating prestin’s involvement in ototoxicity of HPβCD. We found that prestin can interact with cholesterol in vitro, suggesting that HPβCD-induced ototoxicity may involve disruption of this interaction. Time-lapse analysis revealed that OHCs isolated from WT animals rapidly deteriorated upon HPβCD treatment while those from prestin-KOs tolerated the same regimen. These results suggest that a prestin-dependent mechanism contributes to HPβCD ototoxicity. PMID:26903308

  13. Molecular dynamics simulations of cholesterol-rich membranes using a coarse-grained force field for cyclic alkanes

    NASA Astrophysics Data System (ADS)

    MacDermaid, Christopher M.; Kashyap, Hemant K.; DeVane, Russell H.; Shinoda, Wataru; Klauda, Jeffery B.; Klein, Michael L.; Fiorin, Giacomo

    2015-12-01

    The architecture of a biological membrane hinges upon the fundamental fact that its properties are determined by more than the sum of its individual components. Studies on model membranes have shown the need to characterize in molecular detail how properties such as thickness, fluidity, and macroscopic bending rigidity are regulated by the interactions between individual molecules in a non-trivial fashion. Simulation-based approaches are invaluable to this purpose but are typically limited to short sampling times and model systems that are often smaller than the required properties. To alleviate both limitations, the use of coarse-grained (CG) models is nowadays an established computational strategy. We here present a new CG force field for cholesterol, which was developed by using measured properties of small molecules, and can be used in combination with our previously developed force field for phospholipids. The new model performs with precision comparable to atomistic force fields in predicting the properties of cholesterol-rich phospholipid bilayers, including area per lipid, bilayer thickness, tail order parameter, increase in bending rigidity, and propensity to form liquid-ordered domains in ternary mixtures. We suggest the use of this model to quantify the impact of cholesterol on macroscopic properties and on microscopic phenomena involving localization and trafficking of lipids and proteins on cellular membranes.

  14. Differences in X-Chromosome Transcriptional Activity and Cholesterol Metabolism between Placentae from Swine Breeds from Asian and Western Origins

    PubMed Central

    Bischoff, Steve R.; Tsai, Shengdar Q.; Hardison, Nicholas E.; Motsinger-Reif, Alison A.; Freking, Bradley A.; Nonneman, Dan J.; Rohrer, Gary A.; Piedrahita, Jorge A.

    2013-01-01

    To gain insight into differences in placental physiology between two swine breeds noted for their dissimilar reproductive performance, that is, the Chinese Meishan and white composite (WC), we examined gene expression profiles of placental tissues collected at 25, 45, 65, 85, and 105 days of gestation by microarrays. Using a linear mixed model, a total of 1,595 differentially expressed genes were identified between the two pig breeds using a false-discovery rate q-value ≤0.05. Among these genes, we identified breed-specific isoforms of XIST, a long non-coding RNA responsible X-chromosome dosage compensation in females. Additionally, we explored the interaction of placental gene expression and chromosomal location by DIGMAP and identified three Sus scrofa X chromosomal bands (Xq13, Xq21, Xp11) that represent transcriptionally active clusters that differ between Meishan and WC during placental development. Also, pathway analysis identified fundamental breed differences in placental cholesterol trafficking and its synthesis. Direct measurement of cholesterol confirmed that the cholesterol content was significantly higher in the Meishan versus WC placentae. Taken together, this work identifies key metabolic pathways that differ in the placentae of two swine breeds noted for differences in reproductive prolificacy. PMID:23383161

  15. Molecular dynamics simulations of cholesterol-rich membranes using a coarse-grained force field for cyclic alkanes

    SciTech Connect

    MacDermaid, Christopher M. Klein, Michael L.; Fiorin, Giacomo; Kashyap, Hemant K.; DeVane, Russell H.; Shinoda, Wataru; Klauda, Jeffery B.

    2015-12-28

    The architecture of a biological membrane hinges upon the fundamental fact that its properties are determined by more than the sum of its individual components. Studies on model membranes have shown the need to characterize in molecular detail how properties such as thickness, fluidity, and macroscopic bending rigidity are regulated by the interactions between individual molecules in a non-trivial fashion. Simulation-based approaches are invaluable to this purpose but are typically limited to short sampling times and model systems that are often smaller than the required properties. To alleviate both limitations, the use of coarse-grained (CG) models is nowadays an established computational strategy. We here present a new CG force field for cholesterol, which was developed by using measured properties of small molecules, and can be used in combination with our previously developed force field for phospholipids. The new model performs with precision comparable to atomistic force fields in predicting the properties of cholesterol-rich phospholipid bilayers, including area per lipid, bilayer thickness, tail order parameter, increase in bending rigidity, and propensity to form liquid-ordered domains in ternary mixtures. We suggest the use of this model to quantify the impact of cholesterol on macroscopic properties and on microscopic phenomena involving localization and trafficking of lipids and proteins on cellular membranes.

  16. Regulation of biliary cholesterol secretion. Functional relationship between the canalicular and sinusoidal cholesterol secretory pathways in the rat.

    PubMed Central

    Nervi, F; Marinović, I; Rigotti, A; Ulloa, N

    1988-01-01

    The functional interrelationship between biliary cholesterol secretion, sinusoidal lipoprotein cholesterol secretion and bile salt synthesis was studied in the rat. Diosgenin, fructose, and colestipol in the diet were used to, respectively, influence biliary cholesterol output, VLDL production and bile salt synthesis. In the acute bile fistula rat, biliary cholesterol output was 700% increased by diosgenin and 50% decreased by fructose. In the rats fed both diosgenin and fructose, biliary cholesterol secretion was increased only by approximately 200%, whereas biliary bile salts and phospholipid outputs were unchanged. In the isolated perfused liver, VLDL-cholesterol output was 50% reduced by diosgenin alone, but was unchanged following feeding of diosgenin plus fructose. However, the livers of rats fed diosgenin plus fructose exhibited a 700% increase in VLDL-triglyceride production and a 200% increase in VLDL-cholesterol output. A significant reciprocal relationship between VLDL-cholesterol secretion and the coupling ratio of cholesterol to bile salts in bile was observed. Colestipol added to the diet maintained both sinusoidal and biliary cholesterol outputs within the normal range. In the chronic bile fistula rat, colestipol increased bile salt synthesis by 100% while diosgenin and fructose diets had no effect. Similarly, the addition of fructose to the colestipol diet did not decrease bile salt synthesis. These data suggest a reciprocal relationship between biliary cholesterol secretion and hepatic secretion of cholesterol as VLDL particles. The free cholesterol pool used for bile salt synthesis seems functionally unrelated to the pool from which VLDL-cholesterol and biliary cholesterol originate. These findings support the idea that metabolic compartmentalization of hepatic cholesterol is a major determinant of the quantity of cholesterol available for recruitment by the bile salt-dependent biliary cholesterol secretory mechanism. PMID:3198756

  17. 78 FR 76183 - Request for Information for the 2014; Trafficking in Persons Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ... trafficking. (2) For the knowing commission of any act of sex trafficking involving force, fraud, coercion, or in which the victim of sex trafficking is a child incapable of giving meaningful consent, or of... made serious and sustained efforts to reduce the demand for (A) commercial sex acts; and...

  18. 76 FR 1660 - Request for Information for the 2011 Trafficking in Persons Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-11

    ... and punish acts of such trafficking. (2) For the knowing commission of any act of sex trafficking involving force, fraud, coercion, or in which the victim of sex trafficking is a child incapable of giving... government of the country has made serious and sustained efforts to reduce the demand for (A) commercial...

  19. 22 CFR 104.2 - Sharing of information regarding international trafficking in persons.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... trafficking in persons. 104.2 Section 104.2 Foreign Relations DEPARTMENT OF STATE ECONOMIC AND OTHER FUNCTIONS INTERNATIONAL TRAFFICKING IN PERSONS: INTERAGENCY COORDINATION OF ACTIVITIES AND SHARING OF INFORMATION § 104.2 Sharing of information regarding international trafficking in persons. Each Federal Department or...

  20. 76 FR 71830 - Defense Federal Acquisition Regulation Supplement: Administering Trafficking in Persons...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... Regulation Supplement: Administering Trafficking in Persons Regulations (DFARS Case 2011-D051) AGENCY... compliance with duties and responsibilities pertaining to trafficking in persons when they are incorporated... Trafficking in Persons, in all solicitations and contracts. When the contract will be performed outside...

  1. Combating trafficking in persons: a call to action for global health professionals.

    PubMed

    CdeBaca, Luis; Sigmon, Jane Nady

    2014-08-01

    Health care professionals can help identify victims of human trafficking, who commonly come into contact with providers during captivity. Providers can also help restore the physical and mental health of trafficking survivors. Training should focus on recognizing trafficking signs, interviewing techniques, and recommended responses when a victim is identified.

  2. Combating trafficking in persons: a call to action for global health professionals.

    PubMed

    CdeBaca, Luis; Sigmon, Jane Nady

    2014-08-01

    Health care professionals can help identify victims of human trafficking, who commonly come into contact with providers during captivity. Providers can also help restore the physical and mental health of trafficking survivors. Training should focus on recognizing trafficking signs, interviewing techniques, and recommended responses when a victim is identified. PMID:25276585

  3. The Hippo pathway, p53 and cholesterol.

    PubMed

    Aylon, Yael; Oren, Moshe

    2016-09-01

    ASBTRACT Increased rates of cholesterol and lipid synthesis have long been recognized as important aspects of the metabolic rewiring that occurs during cancerous transformation. Many genes encoding enzymes involved in cholesterol and fatty acid biogenesis are transcriptional targets of the sterol regulatory element-binding proteins (SREBPs). The SREBPs act as a hub for metabolic and proliferation-related signals; their activity is the focus of a tug-of-war between tumor suppressors, who generally inhibit SREBP function, and oncogenes, who often promote, and rely on, SREBP activity. The Hippo pathway plays a central role in coordinating cell proliferation and organ size, whereas p53 is a crucial tumor suppressor that maintains metabolic homeostasis and orchestrates cellular stress responses. Together, the Hippo and p53 signaling pathways cooperate on multiple levels to fine-tune SREPB activity and regulate cholesterol/lipid levels. Cholesterol biosynthesis inhibitors such as statins are appealing conceptually, but have yet to show an indisputable effect on cancer development. Fortunately, the complex regulation surrounding the Hippo-p53-SREBP network potentially provides a broad interface for additional novel cancer-targeting interventions. PMID:27419353

  4. The Success Story of LDL Cholesterol Lowering.

    PubMed

    Pedersen, Terje R

    2016-02-19

    We can look back at >100 years of cholesterol research that has brought medicine to a stage where people at risk of severe or fatal coronary heart disease have a much better prognosis than before. This progress has not come about without resistance. Perhaps one of the most debated topics in medicine, the cholesterol controversy, could only be brought to rest through the development of new clinical research methods that were capable of taking advantage of the amazing achievements in basic and pharmacological science after the second World War. It was only after understanding the biochemistry and physiology of cholesterol synthesis, transport and clearance from the blood that medicine could take advantage of drugs and diets to reduce the risk of atherosclerotic diseases. This review points to the highlights of the history of low-density lipoprotein-cholesterol lowering, with the discovery of the low-density lipoprotein receptor and its physiology and not only the development of statins as the stellar moments but also the development of clinical trial methodology as an effective tool to provide scientifically convincing evidence. PMID:26892969

  5. Genetic defects in postsqualene cholesterol biosynthesis.

    PubMed

    Moebius, F F; Fitzky, B U; Glossmann, H

    2000-04-01

    In humans and mice, four different genetic defects in the nine biosynthetic steps from lanosterol to cholesterol have been identified. They impair the activity of a putative C3-sterol dehydrogenase (Nshdl, X-linked dominant bare patches/striated mutation in mice), the sterol delta 8-delta 7 isomerase/EBP (Ebp, X-linked dominant tattered mutation in mice; chondrodysplasia punctata (CDPX2) in humans), the delta 24-sterol reductase (autosomal recessive desmosterolosis) and the delta 7-sterol reductase (DHCR7 gene, autosomal recessive Smith-Lemli-Opitz syndrome in humans). These inborn errors in postsqualene cholesterol metabolism result in dysmorphogenetic syndromes of variable severity. The X-linked dominant mutations result in mosaicism in females, as a result of X-inactivation, and midgestational lethality in males. The mechanisms by which the depletion of cholesterol or the accumulation of intermediates impair morphogenetic programs are unclear. So far, no cellular processes that require an intact cholesterol biosynthetic pathway have been identified, although the morphogenetic hedgehog-patched signaling cascade is a candidate. PMID:10707051

  6. Serum cholesterol concentrations among Navajo Indians.

    PubMed

    Sugarman, J R; Gilbert, T J; Percy, C A; Peter, D G

    1992-01-01

    Navajo Indians have been reported by earlier investigators to have low concentrations of serum lipids and a low prevalence of hyperlipidemia, as well as low rates of ischemic heart disease. However, no data on serum lipid concentrations among Navajos have been reported for more than two decades. The authors conducted a study to determine the distribution of concentrations of serum total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, and triglyceride among persons 25-74 years old living in a representative community on the Navajo Indian reservation. Data are reported for 255 subjects, 105 men and 150 women, ages 25-74 years. The authors compared these data to those for the general population as determined by the second National Health and Nutrition Examination Survey (NHANES II). TC concentrations among Navajo men were similar to those from NHANES II. TC concentrations among younger Navajo women were similar to those for women younger than 55 years from NHANES II, but were significantly lower among older Navajo women. While 27.6 percent of men ages 25-74 years studied in NHANES II had TC concentrations greater than 240 milligrams per deciliter, 33.8 percent of Navajo men had similarly elevated TC. However, the prevalence of serum TC concentrations greater than 240 milligrams per deciliter among Navajo women (17.5 percent) was about half that among women studied in NHANES II (32.9 percent). A similar pattern was found for low density lipoprotein cholesterol. The researchers concluded that Navajo Indians are no longer characterized by low serum lipid concentrations, that increased cholesterol concentrations may be a harbinger of increasing rates of atherosclerotic coronary heart disease among Navajos, and that attention should be directed to primary prevention of hyperlipidemia in Navajo Indian communities. PMID:1738814

  7. Role of Cholesterol Pathways in Norovirus Replication▿

    PubMed Central

    Chang, Kyeong-Ok

    2009-01-01

    Norwalk virus (NV) is a prototype strain of the noroviruses (family Caliciviridae) that have emerged as major causes of acute gastroenteritis worldwide. I have developed NV replicon systems using reporter proteins such as a neomycin-resistant protein (NV replicon-bearing cells) and a green fluorescent protein (pNV-GFP) and demonstrated that these systems were excellent tools to study virus replication in cell culture. In the present study, I first performed DNA microarray analysis of the replicon-bearing cells to identify cellular factors associated with NV replication. The analysis demonstrated that genes in lipid (cholesterol) or carbohydrate metabolic pathways were significantly (P < 0.001) changed by the gene ontology analysis. Among genes in the cholesterol pathways, I found that mRNA levels of hydroxymethylglutaryl-coenzyme A (HMG-CoA) synthase, squalene epoxidase, and acyl-CoA:cholesterol acyltransferase (ACAT), ACAT2, small heterodimer partner, and low-density lipoprotein receptor (LDLR)-related proteins were significantly changed in the cells. I also found that the inhibition of cholesterol biosynthesis using statins (an HMG-CoA reductase inhibitor) significantly increased the levels of NV proteins and RNA, whereas inhibitors of ACAT significantly reduced the replication of NV in replicon-bearing cells. Up- or downregulation of virus replication with these agents significantly correlated with the mRNA level of LDLR in replicon-bearing cells. Finally, I found that the expression of LDLR promoted NV replication in trans by transfection study with pNV-GFP. I conclude that the cholesterol pathways such as LDLR expression and ACAT activity may be crucial in the replication of noroviruses in cells, which may provide potential therapeutic targets for viral infection. PMID:19515767

  8. Bilingual parallel programming

    SciTech Connect

    Foster, I.; Overbeek, R.

    1990-01-01

    Numerous experiments have demonstrated that computationally intensive algorithms support adequate parallelism to exploit the potential of large parallel machines. Yet successful parallel implementations of serious applications are rare. The limiting factor is clearly programming technology. None of the approaches to parallel programming that have been proposed to date -- whether parallelizing compilers, language extensions, or new concurrent languages -- seem to adequately address the central problems of portability, expressiveness, efficiency, and compatibility with existing software. In this paper, we advocate an alternative approach to parallel programming based on what we call bilingual programming. We present evidence that this approach provides and effective solution to parallel programming problems. The key idea in bilingual programming is to construct the upper levels of applications in a high-level language while coding selected low-level components in low-level languages. This approach permits the advantages of a high-level notation (expressiveness, elegance, conciseness) to be obtained without the cost in performance normally associated with high-level approaches. In addition, it provides a natural framework for reusing existing code.

  9. To Your Health: NLM update transcript - Cholesterol screening for kids?

    MedlinePlus

    ... transcript102416.html To Your Health: NLM update Transcript Cholesterol screening for kids? : 10/24/2016 To use ... the need for children to be screened for cholesterol levels in their bloodstream, finds a recent article ...

  10. Talk with Your Health Care Provider about High Cholesterol

    MedlinePlus

    ... you do? Always ask your provider what your cholesterol numbers are and write them down. Discuss these ... provider may prescribe medicine to help lower your cholesterol. y y Take your medicine every day, or ...

  11. Biliary cholesterol transport and precipitation: introduction and overview of conference.

    PubMed

    Strasberg, S M; Harvey, P R

    1990-09-01

    Cholesterol is secreted into bile as cholesterol-phospholipid vesicles. The cholesterol and phospholipid are subsequently exposed to the bile salts contained in the bile, which leads to the process of micellation. Two situations may arise depending on whether there is enough bile salt in proportion to cholesterol to complete this "maturation" process. If the cholesterol saturation is low, at equilibrium the bile salts will have completely micellized the vesicles. On the other hand, if bile is saturated with cholesterol, the micellation process is incomplete and vesicles and micelles will be present at equilibrium. The residual vesicle in this latter situation may have a higher cholesterol/phospholipid ratio because of the greater propensity of phospholipid to be micellized. This situation may result in cholesterol nucleation. The mechanism of nucleation from vesicles and the possible role of nucleating and antinucleating proteins in this process have been discussed.

  12. 31 CFR 598.313 - Significant foreign narcotics trafficker.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Significant foreign narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.313 Significant foreign narcotics trafficker. The term...

  13. 31 CFR 598.314 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.314 Specially designated narcotics trafficker. The term...

  14. 31 CFR 598.313 - Significant foreign narcotics trafficker.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Significant foreign narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.313 Significant foreign narcotics trafficker. The term...

  15. 31 CFR 598.313 - Significant foreign narcotics trafficker.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Significant foreign narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.313 Significant foreign narcotics trafficker. The term...

  16. 31 CFR 598.314 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.314 Specially designated narcotics trafficker. The term...

  17. 31 CFR 598.313 - Significant foreign narcotics trafficker.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Significant foreign narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.313 Significant foreign narcotics trafficker. The term...

  18. 31 CFR 598.314 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.314 Specially designated narcotics trafficker. The term...

  19. 31 CFR 598.313 - Significant foreign narcotics trafficker.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Significant foreign narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.313 Significant foreign narcotics trafficker. The term...

  20. 31 CFR 598.314 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Specially designated narcotics... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY FOREIGN NARCOTICS KINGPIN SANCTIONS REGULATIONS General Definitions § 598.314 Specially designated narcotics trafficker. The term...

  1. Child Trafficking in West Africa: Policy Responses. Innocenti Insight.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, Florence (Italy). Innocenti Research Centre.

    This report examines policy responses and programming trends to combat the growing specter of child trafficking, focusing on the region of west and central Africa where strenuous advocacy efforts by UNICEF and its partners have helped to bring this problem to national and international attention. The report focuses on policy trends on child…

  2. Human Trafficking: A Call for Counselor Awareness and Action

    ERIC Educational Resources Information Center

    Stotts, Edward L., Jr.; Ramey, Luellen

    2009-01-01

    The counseling profession has given little attention to human trafficking, a form of modern slavery that is one of the most damaging forms of social injustice that exists today. Focusing on victims within the United States, the authors provide advocacy suggestions, treatment recommendations, and directions for research for this population.

  3. 48 CFR 52.222-50 - Combating Trafficking in Persons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... bondage, or slavery. Sex trafficking means the recruitment, harboring, transportation, provision, or obtaining of a person for the purpose of a commercial sex act. (b) Policy. The United States Government has...) Notify its employees of— (i) The United States Government's zero tolerance policy described in...

  4. Regulation of intracellular heme trafficking revealed by subcellular reporters.

    PubMed

    Yuan, Xiaojing; Rietzschel, Nicole; Kwon, Hanna; Walter Nuno, Ana Beatriz; Hanna, David A; Phillips, John D; Raven, Emma L; Reddi, Amit R; Hamza, Iqbal

    2016-08-30

    Heme is an essential prosthetic group in proteins that reside in virtually every subcellular compartment performing diverse biological functions. Irrespective of whether heme is synthesized in the mitochondria or imported from the environment, this hydrophobic and potentially toxic metalloporphyrin has to be trafficked across membrane barriers, a concept heretofore poorly understood. Here we show, using subcellular-targeted, genetically encoded hemoprotein peroxidase reporters, that both extracellular and endogenous heme contribute to cellular labile heme and that extracellular heme can be transported and used in toto by hemoproteins in all six subcellular compartments examined. The reporters are robust, show large signal-to-background ratio, and provide sufficient range to detect changes in intracellular labile heme. Restoration of reporter activity by heme is organelle-specific, with the Golgi and endoplasmic reticulum being important sites for both exogenous and endogenous heme trafficking. Expression of peroxidase reporters in Caenorhabditis elegans shows that environmental heme influences labile heme in a tissue-dependent manner; reporter activity in the intestine shows a linear increase compared with muscle or hypodermis, with the lowest heme threshold in neurons. Our results demonstrate that the trafficking pathways for exogenous and endogenous heme are distinct, with intrinsic preference for specific subcellular compartments. We anticipate our results will serve as a heuristic paradigm for more sophisticated studies on heme trafficking in cellular and whole-animal models.

  5. Regulation of intracellular heme trafficking revealed by subcellular reporters.

    PubMed

    Yuan, Xiaojing; Rietzschel, Nicole; Kwon, Hanna; Walter Nuno, Ana Beatriz; Hanna, David A; Phillips, John D; Raven, Emma L; Reddi, Amit R; Hamza, Iqbal

    2016-08-30

    Heme is an essential prosthetic group in proteins that reside in virtually every subcellular compartment performing diverse biological functions. Irrespective of whether heme is synthesized in the mitochondria or imported from the environment, this hydrophobic and potentially toxic metalloporphyrin has to be trafficked across membrane barriers, a concept heretofore poorly understood. Here we show, using subcellular-targeted, genetically encoded hemoprotein peroxidase reporters, that both extracellular and endogenous heme contribute to cellular labile heme and that extracellular heme can be transported and used in toto by hemoproteins in all six subcellular compartments examined. The reporters are robust, show large signal-to-background ratio, and provide sufficient range to detect changes in intracellular labile heme. Restoration of reporter activity by heme is organelle-specific, with the Golgi and endoplasmic reticulum being important sites for both exogenous and endogenous heme trafficking. Expression of peroxidase reporters in Caenorhabditis elegans shows that environmental heme influences labile heme in a tissue-dependent manner; reporter activity in the intestine shows a linear increase compared with muscle or hypodermis, with the lowest heme threshold in neurons. Our results demonstrate that the trafficking pathways for exogenous and endogenous heme are distinct, with intrinsic preference for specific subcellular compartments. We anticipate our results will serve as a heuristic paradigm for more sophisticated studies on heme trafficking in cellular and whole-animal models. PMID:27528661

  6. 31 CFR 598.314 - Specially designated narcotics trafficker.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... REGULATIONS General Definitions § 598.314 Specially designated narcotics trafficker. The term specially... Central Intelligence, the Director of the Federal Bureau of Investigation, the Administrator of the Drug... persons determined to fall within this definition who have been designated pursuant to this part....

  7. Analysis of Lipolytic Protein Trafficking and Interactions in Adipocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work examined the colocalization, trafficking, and interactions of key proteins involved in lipolysis during brief cAMP-dependent protein kinase A (PKA) activation. Double label immunofluorescence analysis of 3T3-L1 adipocytes indicated that PKA activation increases the translocation of hormon...

  8. Plant vacuolar trafficking occurs through distinctly regulated pathways.

    PubMed

    Ebine, Kazuo; Inoue, Takeshi; Ito, Jun; Ito, Emi; Uemura, Tomohiro; Goh, Tatsuaki; Abe, Hiroshi; Sato, Ken; Nakano, Akihiko; Ueda, Takashi

    2014-06-16

    The multifunctional vacuole is the largest organelle in plant cells, and many proteins are transported to and stored in this organelle; thus, the vacuole has great physiological and agronomical importance. However, the molecular mechanism and regulation of plant vacuolar traffic remain largely unknown. In this study, we demonstrate that multiple vacuolar trafficking pathways operate in plants. RAB5 and RAB7 are evolutionarily conserved subfamilies of Rab GTPase, whose animal and yeast counterparts regulate vacuolar/endosomal trafficking in a sequential manner. Functional analyses of a putative activating complex for RAB7 indicated that this complex is responsible for maturation from RAB5- to RAB7-positive endosomes in plant cells. Moreover, these machinery components are recruited to a more complex trafficking network. Mutations in RAB5 and RAB7 conferred counteracting effects on the vti11 mutant. Furthermore, impairment of RAB5- and RAB7-dependent pathways differentially affected the transport of distinctive cargos. These results indicate that plants have developed a complex vacuolar transport system distinct from that of nonplant systems by assigning evolutionarily conserved machinery to unique trafficking pathways. These pathways provide a fundamental basis for plant development at the cellular and higher-ordered levels.

  9. Intracellular Trafficking Network of Protein Nanocapsules: Endocytosis, Exocytosis and Autophagy

    PubMed Central

    Zhang, Jinxie; Zhang, Xudong; Liu, Gan; Chang, Danfeng; Liang, Xin; Zhu, Xianbing; Tao, Wei; Mei, Lin

    2016-01-01

    The inner membrane vesicle system is a complex transport system that includes endocytosis, exocytosis and autophagy. However, the details of the intracellular trafficking pathway of nanoparticles in cells have been poorly investigated. Here, we investigate in detail the intracellular trafficking pathway of protein nanocapsules using more than 30 Rab proteins as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy. We observed that FITC-labeled protein nanoparticles were internalized by the cells mainly through Arf6-dependent endocytosis and Rab34-mediated micropinocytosis. In addition to this classic pathway: early endosome (EEs)/late endosome (LEs) to lysosome, we identified two novel transport pathways: micropinocytosis (Rab34 positive)-LEs (Rab7 positive)-lysosome pathway and EEs-liposome (Rab18 positive)-lysosome pathway. Moreover, the cells use slow endocytosis recycling pathway (Rab11 and Rab35 positive vesicles) and GLUT4 exocytosis vesicles (Rab8 and Rab10 positive) transport the protein nanocapsules out of the cells. In addition, protein nanoparticles are observed in autophagosomes, which receive protein nanocapsules through multiple endocytosis vesicles. Using autophagy inhibitor to block these transport pathways could prevent the degradation of nanoparticles through lysosomes. Using Rab proteins as vesicle markers to investigation the detail intracellular trafficking of the protein nanocapsules, will provide new targets to interfere the cellular behaver of the nanoparticles, and improve the therapeutic effect of nanomedicine.

  10. Leukocyte trafficking: Can we bring the fight to the tumor?

    PubMed

    Pachynski, Russell; Nazha, Jonathon; Kohrt, Holbrook

    2016-03-01

    Control of leukocyte trafficking plays a critical role in the establishment of effective immune responses. It is now well established that the number or ratio of effector to suppressor immune cells within the tumor microenvironment can significantly impact tumor growth and clinical outcomes. Recently approved immunotherapies by the FDA, and those in development, aim to stimulate effector immune cell function. For example, many checkpoint inhibitors seek to stimulate an immune response to tumors by reversing T-cell exhaustion. However, activation of the immune response outside the tumor microenvironment can lead to sometimes fatal immune-mediated adverse events -- the result of "on-target, off-tumor" effects. Thus, control of localization of these activated effector cells remains a critical component of optimizing tumor response while minimizing immune-mediated adverse events. Chemokines and chemoattractants, along with their receptors on immune cells, govern leukocyte trafficking; thus, understanding their expression pattern in the context of the tumor microenvironment and developing approaches to favorably alter those should lead to improved efficacy of current immunotherapeutics. This review highlights the background of cancer immunotherapy, leukocyte trafficking, and some novel approaches being utilized to optimize recruitment of effector immune cells into the tumor microenvironment. Future combinatorial immunotherapy should incorporate therapeutics aimed at 1) favorably altering the tumor microenvironment, 2) activating effector immune cells, and 3) optimizing effector cell trafficking into tumors.

  11. Trafficking of ciliary G protein-coupled receptors.

    PubMed

    McIntyre, Jeremy C; Hege, Mellisa M; Berbari, Nicolas F

    2016-01-01

    In the last decade highly conserved cellular appendages called cilia have enjoyed a renewed interest from basic, biomedical scientists, and clinicians alike. This interest has grown upon the elucidation that cilia throughout the body serve as important sensory and signaling centers in both development and adult homeostasis. Furthermore, the identification of several rare genetic disorders associated with cilia dysfunction has broadened the field. However, even though their potential role in human health and disease is now recognized many basic questions about their functions remain. This chapter seeks to explore the trafficking of cilia-specific G protein-coupled receptors (GPCRs) and discusses several model systems in which this has been explored. We open the chapter by briefly discussing cilia and GPCRs then begin discussing some aspects of rhodopsin trafficking, arguably the most well studied of cilia GPCRs. We continue with sections on neuronal cilia and olfactory cilia receptor trafficking. Finally, we conclude with the emerging area of dynamic ciliary GPCR trafficking and speculate about future directions and some of the questions that remain for ciliary GPCRs. PMID:26928538

  12. Intracellular Trafficking Network of Protein Nanocapsules: Endocytosis, Exocytosis and Autophagy

    PubMed Central

    Zhang, Jinxie; Zhang, Xudong; Liu, Gan; Chang, Danfeng; Liang, Xin; Zhu, Xianbing; Tao, Wei; Mei, Lin

    2016-01-01

    The inner membrane vesicle system is a complex transport system that includes endocytosis, exocytosis and autophagy. However, the details of the intracellular trafficking pathway of nanoparticles in cells have been poorly investigated. Here, we investigate in detail the intracellular trafficking pathway of protein nanocapsules using more than 30 Rab proteins as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy. We observed that FITC-labeled protein nanoparticles were internalized by the cells mainly through Arf6-dependent endocytosis and Rab34-mediated micropinocytosis. In addition to this classic pathway: early endosome (EEs)/late endosome (LEs) to lysosome, we identified two novel transport pathways: micropinocytosis (Rab34 positive)-LEs (Rab7 positive)-lysosome pathway and EEs-liposome (Rab18 positive)-lysosome pathway. Moreover, the cells use slow endocytosis recycling pathway (Rab11 and Rab35 positive vesicles) and GLUT4 exocytosis vesicles (Rab8 and Rab10 positive) transport the protein nanocapsules out of the cells. In addition, protein nanoparticles are observed in autophagosomes, which receive protein nanocapsules through multiple endocytosis vesicles. Using autophagy inhibitor to block these transport pathways could prevent the degradation of nanoparticles through lysosomes. Using Rab proteins as vesicle markers to investigation the detail intracellular trafficking of the protein nanocapsules, will provide new targets to interfere the cellular behaver of the nanoparticles, and improve the therapeutic effect of nanomedicine. PMID:27698943

  13. 78 FR 59950 - Advisory Council on Wildlife Trafficking

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... Fish and Wildlife Service Advisory Council on Wildlife Trafficking AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of meeting. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a... strategies to reduce illicit trade and consumer demand for illegally traded wildlife, including...

  14. The NAS parallel benchmarks

    NASA Technical Reports Server (NTRS)

    Bailey, David (Editor); Barton, John (Editor); Lasinski, Thomas (Editor); Simon, Horst (Editor)

    1993-01-01

    A new set of benchmarks was developed for the performance evaluation of highly parallel supercomputers. These benchmarks consist of a set of kernels, the 'Parallel Kernels,' and a simulated application benchmark. Together they mimic the computation and data movement characteristics of large scale computational fluid dynamics (CFD) applications. The principal distinguishing feature of these benchmarks is their 'pencil and paper' specification - all details of these benchmarks are specified only algorithmically. In this way many of the difficulties associated with conventional benchmarking approaches on highly parallel systems are avoided.

  15. Ezetimibe and Simvastatin Reduce Cholesterol Levels in Zebrafish Larvae Fed a High-Cholesterol Diet

    PubMed Central

    Baek, Ji Sun; Fang, Longhou; Li, Andrew C.; Miller, Yury I.

    2012-01-01

    Cholesterol-fed zebrafish is an emerging animal model to study metabolic, oxidative, and inflammatory vascular processes relevant to pathogenesis of human atherosclerosis. Zebrafish fed a high-cholesterol diet (HCD) develop hypercholesterolemia and are characterized by profound lipoprotein oxidation and vascular lipid accumulation. Using optically translucent zebrafish larvae has the advantage of monitoring vascular pathology and assessing the efficacy of drug candidates in live animals. Thus, we investigated whether simvastatin and ezetimibe, the principal drugs used in management of hypercholesterolemia in humans, would also reduce cholesterol levels in HCD-fed zebrafish larvae. We found that ezetimibe was well tolerated by zebrafish and effectively reduced cholesterol levels in HCD-fed larvae. In contrast, simvastatin added to water was poorly tolerated by zebrafish larvae and, when added to food, had little effect on cholesterol levels in HCD-fed larvae. Combination of low doses of ezetimibe and simvastatin had an additive effect in reducing cholesterol levels in zebrafish. These results suggest that ezetimibe exerts in zebrafish a therapeutic effect similar to that in humans and that the hypercholesterolemic zebrafish can be used as a low-cost and informative model for testing new drug candidates and for investigating mechanisms of action for existing drugs targeting dyslipidemia. PMID:22693663

  16. Metabolism of low-density lipoprotein free cholesterol by human plasma lecithin-cholesterol acyltransferase

    SciTech Connect

    Fielding, P.E.; Miida, Takashi; Fielding, C.J. )

    1991-09-03

    The metabolism of cholesterol derived from ({sup 3}H) cholesterol-labeled low-density lipoprotein (LDL) was determined in human blood plasma. LDL-derived free cholesterol first appeared in large {alpha}-migrating HDL (HDL{sub 2}) and was then transferred to small {alpha}-HDL (HDL{sub 3}) for esterification. The major part of such esters was retained within HDL of increasing size in the course of lecithin-cholesterol acyltransferase (LCAT) activity; the balance was recovered in LDL. Transfer of preformed cholesteryl esters within HDL contributed little to the labeled cholesteryl ester accumulating HDL{sub 2}. When cholesterol for esterification was derived instead from cell membranes, a significantly smaller proportion of this cholesteryl ester was subsequently recovered in LDL. These data suggest compartmentation of cholesteryl esters within plasma that have been formed from cell membrane or LDL free cholesterol, and the role for HDL{sub 2} as a relatively unreactive sink for LCAT-derived cholesteryl esters.

  17. Cholesterol determination using protein-templated fluorescent gold nanocluster probes.

    PubMed

    Chen, Xi; Baker, Gary A

    2013-11-12

    We describe the development of a fluorescent biosensor platform for soluble cholesterol based on bovine serum albumin-stabilized gold nanocluster probes co-dissolved with cholesterol oxidase (ChOx) in a surfactant emulsion system. Selective enzymatic oxidation of cholesterol to cholest-4-en-3-one by ChOx produces stoichiometric amounts of H2O2 by-product, generating a quenching response signaling the presence of cholesterol at clinically relevant levels (LOD ∼12 μM).

  18. Neutrophil elastase and proteinase 3 trafficking routes in myelomonocytic cells

    SciTech Connect

    Kaellquist, Linda; Rosen, Hanna; Nordenfelt, Pontus; Calafat, Jero; Janssen, Hans; Persson, Ann-Maj; Hansson, Markus; Olsson, Inge

    2010-11-15

    Neutrophil elastase (NE) and proteinase 3 (PR3) differ in intracellular localization, which may reflect different trafficking mechanisms of the precursor forms when synthesized at immature stages of neutrophils. To shed further light on these mechanisms, we compared the trafficking of precursor NE (proNE) and precursor PR3 (proPR3). Like proNE [1], proPR3 interacted with CD63 upon heterologous co-expression in COS cells but endogenous interaction was not detected although cell surface proNE/proPR3/CD63 were co-endocytosed in myelomonocytic cells. Cell surface proNE/proPR3 turned over more rapidly than cell surface CD63 consistent with processing/degradation of the pro-proteases but recycling of CD63. Colocalization of proNE/proPR3/CD63 with clathrin and Rab 7 suggested trafficking through coated vesicles and late endosomes. Partial caveolar trafficking of proNE/CD63 but not proPR3 was suggested by colocalization with caveolin-1. Blocking the C-terminus of proNE/proPR3 by creating a fusion with FK506 binding protein inhibited endosomal re-uptake of proNE but not proPR3 indicating 'pro{sub C}'-peptide-dependent structural/conformational requirements for proNE but not for proPR3 endocytosis. The NE aminoacid residue Y199 of a proposed NE sorting motif that interacts with AP-3 [2] was not required for proNE processing, sorting or endocytosis in rat basophilic leukemia (RBL) cells expressing heterologous Y199-deleted proNE; this suggests operation of another AP-3-link for proNE targeting. Our results show intracellular multi-step trafficking to be different between proNE and proPR3 consistent with their differential subcellular NE/PR3 localization in neutrophils.

  19. Rab GTPase mediated procollagen trafficking in ascorbic acid stimulated osteoblasts.

    PubMed

    Nabavi, Noushin; Pustylnik, Sofia; Harrison, Rene E

    2012-01-01

    Despite advances in investigating functional aspects of osteoblast (OB) differentiation, especially studies on how bone proteins are deposited and mineralized, there has been little research on the intracellular trafficking of bone proteins during OB differentiation. Collagen synthesis and secretion is the major function of OBs and is markedly up-regulated upon ascorbic acid (AA) stimulation, significantly more so than in fibroblast cells. Understanding the mechanism by which collagen is mobilized in specialized OB cells is important for both basic cell biology and diseases involving defects in bone protein secretion and deposition. Protein trafficking along the exocytic and endocytic pathways is aided by many molecules, with Rab GTPases being master regulators of vesicle targeting. In this study, we used microarray analysis to identify the Rab GTPases that are up-regulated during a 5-day AA differentiation of OBs, namely Rab1, Rab3d, and Rab27b. Further, we investigated the role of identified Rabs in regulating the trafficking of collagen from the site of synthesis in the ER to the Golgi and ultimately to the plasma membrane utilizing Rab dominant negative (DN) expression. We also observed that experimental halting of biosynthetic trafficking by these mutant Rabs initiated proteasome-mediated degradation of procollagen and ceased global protein translation. Acute expression of Rab1 and Rab3d DN constructs partially alleviated this negative feedback mechanism and resulted in impaired ER to Golgi trafficking of procollagen. Similar expression of Rab27b DN constructs resulted in dispersed collagen vesicles which may represent failed secretory vesicles sequestered in the cytosol. A significant and strong reduction in extracellular collagen levels was also observed implicating the functional importance of Rab1, Rab3d and Rab27b in these major collagen-producing cells.

  20. Microtubule and Actin Interplay Drive Intracellular c-Src Trafficking.

    PubMed

    Arnette, Christopher; Frye, Keyada; Kaverina, Irina

    2016-01-01

    The proto-oncogene c-Src is involved in a variety of signaling processes. Therefore, c-Src spatiotemporal localization is critical for interaction with downstream targets. However, the mechanisms regulating this localization have remained elusive. Previous studies have shown that c-Src trafficking is a microtubule-dependent process that facilitates c-Src turnover in neuronal growth cones. As such, microtubule depolymerization lead to the inhibition of c-Src recycling. Alternatively, c-Src trafficking was also shown to be regulated by RhoB-dependent actin polymerization. Our results show that c-Src vesicles primarily exhibit microtubule-dependent trafficking; however, microtubule depolymerization does not inhibit vesicle movement. Instead, vesicular movement becomes both faster and less directional. This movement was associated with actin polymerization directly at c-Src vesicle membranes. Interestingly, it has been shown previously that c-Src delivery is an actin polymerization-dependent process that relies on small GTPase RhoB at c-Src vesicles. In agreement with this finding, microtubule depolymerization induced significant activation of RhoB, together with actin comet tail formation. These effects occurred downstream of GTP-exchange factor, GEF-H1, which was released from depolymerizing MTs. Accordingly, GEF-H1 activity was necessary for actin comet tail formation at the Src vesicles. Our results indicate that regulation of c-Src trafficking requires both microtubules and actin polymerization, and that GEF-H1 coordinates c-Src trafficking, acting as a molecular switch between these two mechanisms. PMID:26866809