The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Elizabeth Murphy - One of the best experts on this subject based on the ideXlab platform.
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Measurement of reverse cholesterol transport pathways in humans: in vivo rates of free cholesterol efflux, esterification, and excretion.
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael Davidson, Elizabeth MurphyAbstract:BACKGROUND: Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. METHODS AND RESULTS: A constant infusion of [2,3-(13)C(2)]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester (13)C-enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-(13)C(2)]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≍8 g/d. Red blood cell-derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≍28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-(13)C(2)]-cholesterol in fecal bile acids and neutral sterols, respectively. CONCLUSIONS: Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans. (J Am Heart Assoc. 2012;1:e001826 doi: 10.1161/JAHA.112.001826.).
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measurement of reverse cholesterol transport pathways in humans in vivo rates of free cholesterol efflux esterification and excretion
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael H Davidson, Elizabeth MurphyAbstract:Background Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. Methods and Results A constant infusion of [2,3-13C2]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester 13C–enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-13C2]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≈8 g/d. Red blood cell–derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≈28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-13C2]-cholesterol in fecal bile acids and neutral sterols, respectively. Conclusions Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans.
Scott Turner - One of the best experts on this subject based on the ideXlab platform.
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Measurement of reverse cholesterol transport pathways in humans: in vivo rates of free cholesterol efflux, esterification, and excretion.
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael Davidson, Elizabeth MurphyAbstract:BACKGROUND: Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. METHODS AND RESULTS: A constant infusion of [2,3-(13)C(2)]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester (13)C-enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-(13)C(2)]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≍8 g/d. Red blood cell-derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≍28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-(13)C(2)]-cholesterol in fecal bile acids and neutral sterols, respectively. CONCLUSIONS: Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans. (J Am Heart Assoc. 2012;1:e001826 doi: 10.1161/JAHA.112.001826.).
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measurement of reverse cholesterol transport pathways in humans in vivo rates of free cholesterol efflux esterification and excretion
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael H Davidson, Elizabeth MurphyAbstract:Background Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. Methods and Results A constant infusion of [2,3-13C2]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester 13C–enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-13C2]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≈8 g/d. Red blood cell–derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≈28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-13C2]-cholesterol in fecal bile acids and neutral sterols, respectively. Conclusions Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans.
Elise F. Stanley - One of the best experts on this subject based on the ideXlab platform.
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The transmitter release-site CaV2.2 channel cluster is linked to an endocytosis coat protein complex.
The European journal of neuroscience, 2007Co-Authors: Rajesh Khanna, Lyanne C. Schlichter, Elise F. StanleyAbstract:Synaptic vesicles (SVs) are triggered to fuse with the surface membrane at the presynaptic transmitter release site (TRSs) core by Ca 2+ influx through nearby attached CaV2.2 channels [see accompanying paper: Khanna et al. (2007) Eur. J. Neurosci., 26, 547‐ 559] and are then recovered by endocytosis. In this study we test the hypothesis that the TRS core is linked to an endocytosis-related protein complex. This was tested by immunostaining analysis of the chick ciliary ganglion calyx presynaptic terminal and biochemical analysis of synaptosome lysate, using CaV2.2 as a marker for the TRS. We noted that CaV2.2 clusters abut heavy-chain (H)-clathrin patches at the transmitter release face. Quantitative coimmunostaining analysis (ICA ⁄ICQ method) demonstrated a strong covariance of release-face CaV2.2 staining with that for the AP180 and intersectin endocytosis adaptor proteins, and a moderate covariance with H- or light-chain (L)-clathrin and dynamin coat proteins, consistent with a multimolecular complex. This was supported by coprecipitation of these proteins with CaV2.2 from brain synaptosome lysate. Interestingly, the channel neither colocalized nor coprecipitated with the endocytosis cargo-capturing adaptor AP2, even though this protein both colocalized and coprecipitated with H-clathrin. Fractional Recovery analysis of the immunoprecipitated CaV2.2 complex by exposure to high NaCl (� 1 m) indicated that AP180 and S-intersectin adaptors are tightly bound to CaV2.2 while L-intersectin, H- and L-clathrin and dynamin form a less tightly linked subcomplex. Our results are consistent with two distinct clathrin endocytosis complexes: an AP2-containing, remote, non-TRS complex and a specialised, AP2-lacking, TRS-associated subcomplex linked via a molecular bridge. The most probable role of this subcomplex is to facilitate SV Recovery after transmitter release.
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‘Fractional Recovery’ Analysis of a Presynaptic Synaptotagmin 1-Anchored Endocytic Protein Complex
PloS one, 2006Co-Authors: Rajesh Khanna, Elise F. StanleyAbstract:Background. The integral synaptic vesicle protein and putative calcium sensor, synaptotagmin 1 (STG), has also been implicated in synaptic vesicle (SV) Recovery. However, proteins with which STG interacts during SV endocytosis remain poorly understood. We have isolated an STG-associated endocytic complex (SAE) from presynaptic nerve terminals and have used a novel Fractional Recovery (FR) assay based on electrostatic dissociation to identify SAE components and map the complex structure. The location of SAE in the presynaptic terminal was determined by high-resolution quantitative immunocytochemistry at the chick ciliary ganglion giant calyx-type synapse. Methodology/Principle Findings. The first step in FR analysis was to immunoprecipitate (IP) the complex with an antibody against one protein component (the IP-protein). The immobilized complex was then exposed to a high salt (1150 mM) stress-test that caused shedding of co-immunoprecipitated proteins (coIP-proteins). A Fractional Recovery ratio (FR: Recovery after high salt/Recovery with control salt as assayed by Western blot) was calculated for each co-IP-protein. These FR values reflect complex structure since an easily dissociated protein, with a low FR value, cannot be intermediary between the IP-protein and a salt-resistant protein. The structure of the complex was mapped and a blueprint generated with a pair of FR analyses generated using two different IP-proteins. The blueprint of SAE contains an AP180/X/STG/stonin 2/intersectin/epsin core (X is unknown and epsin is hypothesized), and an AP2 adaptor, H-/L-clathrin coat and dynamin scission protein perimeter. Quantitative immunocytochemistry (ICA/ICQ method) at an isolated calyx-type presynaptic terminal indicates that this complex is associated with STG at the presynaptic transmitter release face but not with STG on intracellular synaptic vesicles. Conclusions/Significance. We hypothesize that the SAE serves as a recognition site and also as a seed complex for clathrin-mediated synaptic vesicle Recovery. The combination of FR analysis with quantitative immunocytochemistry provides a novel and effective strategy for the identification and characterization of biologicallyrelevant multi-molecular complexes.
Drina Boban - One of the best experts on this subject based on the ideXlab platform.
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Measurement of reverse cholesterol transport pathways in humans: in vivo rates of free cholesterol efflux, esterification, and excretion.
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael Davidson, Elizabeth MurphyAbstract:BACKGROUND: Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. METHODS AND RESULTS: A constant infusion of [2,3-(13)C(2)]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester (13)C-enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-(13)C(2)]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≍8 g/d. Red blood cell-derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≍28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-(13)C(2)]-cholesterol in fecal bile acids and neutral sterols, respectively. CONCLUSIONS: Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans. (J Am Heart Assoc. 2012;1:e001826 doi: 10.1161/JAHA.112.001826.).
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measurement of reverse cholesterol transport pathways in humans in vivo rates of free cholesterol efflux esterification and excretion
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael H Davidson, Elizabeth MurphyAbstract:Background Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. Methods and Results A constant infusion of [2,3-13C2]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester 13C–enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-13C2]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≈8 g/d. Red blood cell–derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≈28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-13C2]-cholesterol in fecal bile acids and neutral sterols, respectively. Conclusions Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans.
Julie Decaris - One of the best experts on this subject based on the ideXlab platform.
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Measurement of reverse cholesterol transport pathways in humans: in vivo rates of free cholesterol efflux, esterification, and excretion.
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael Davidson, Elizabeth MurphyAbstract:BACKGROUND: Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. METHODS AND RESULTS: A constant infusion of [2,3-(13)C(2)]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester (13)C-enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-(13)C(2)]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≍8 g/d. Red blood cell-derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≍28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-(13)C(2)]-cholesterol in fecal bile acids and neutral sterols, respectively. CONCLUSIONS: Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans. (J Am Heart Assoc. 2012;1:e001826 doi: 10.1161/JAHA.112.001826.).
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measurement of reverse cholesterol transport pathways in humans in vivo rates of free cholesterol efflux esterification and excretion
Journal of the American Heart Association, 2012Co-Authors: Scott Turner, Julie Decaris, Jason Voogt, Alex Glass, Salena Killion, Hussein Mohammed, Kaori Minehira, Drina Boban, Michael H Davidson, Elizabeth MurphyAbstract:Background Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high-density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (FC) efflux, esterification of FC in plasma, and fecal sterol excretion of plasma-derived FC. Methods and Results A constant infusion of [2,3-13C2]-cholesterol was administered to healthy volunteers. Three-compartment SAAM II (Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma FC, red blood cell FC, and plasma cholesterol ester 13C–enrichment profiles. Fecal sterol excretion of plasma-derived FC was quantified from Fractional Recovery of intravenous [2,3-13C2]-cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue FC efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≈8 g/d. Red blood cell–derived flux into plasma FC was 3.38±1.10 mg/kg per hour. Esterification of plasma FC was ≈28% of tissue FC efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3-13C2]-cholesterol in fecal bile acids and neutral sterols, respectively. Conclusions Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high-density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans.
