scholarly journals No effect of 10 weeks erythropoietin treatment on lipid oxidation in healthy men

2020 ◽  
Vol 9 (12) ◽  
pp. 1148-1155
Author(s):  
Jeyanthini Risikesan ◽  
Birgitte Nellemann ◽  
Britt Christensen ◽  
Jens Otto Lunde Jørgensen ◽  
Søren Nielsen
Keyword(s):  
Fatty Acids ◽  
Lipid Oxidation ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Resting Energy Expenditure ◽  
Oxidation Rates ◽  
Relative Contribution ◽  
The Impact

Studies indicate that erythropoietin (EPO) has effect on lipid and energy metabolism; however, the impact of EPO on lipid oxidation in vivo has not been well documented. Here, we evaluate whether long-term erythropoiesis-stimulating agent (ESA) treatment affects the oxidation of plasma very low-density lipoprotein triglycerides (VLDL-TG) fatty acids (FA), plasma free fatty acids (FFA) and non-plasma (residual) FA in healthy, young, sedentary men. Infusion of [1-14C]VLDL-TG and [9,10-3H]palmitate was used in combination with indirect calorimetry to assess resting lipid fuel utilization and kinetics, and resting energy expenditure (REE) before and after 10 weeks of ESA exposure compared with placebo. REE increased significantly during ESA compared with placebo (P = 0.023, RM-ANOVA). Oxidation rates of VLDL-TG FA, FFA, and residual FA remained unchanged during ESA compared with placebo. The relative contribution of the lipid stores was greatest for FFA (47.1%) and the total lipid oxidation rate and was not significantly different between ESA and placebo-treated subjects. We conclude that long-term ESA treatment of healthy young men increases REE but does not alter the oxidation rates of plasma and non-plasma FA sources.

scholarly journals Liver X Receptor Nuclear Receptors Are Transcriptional Regulators of Dendritic Cell Chemotaxis

2018 ◽  
Vol 38 (10) ◽  
Author(s):  
Susana Beceiro ◽  
Attila Pap ◽  
Zsolt Czimmerer ◽  
Tamer Sallam ◽  
Jose A. Guillén ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Low Density Lipoprotein ◽  
Myeloid Cells ◽  
Density Lipoprotein ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Cd38 Expression ◽  
The Impact

ABSTRACTThe liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migrationin vitroandin vivo. Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR−/−) LDLR−/−mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.

Abstract 598: Deletion of Microsomal PGE Synthase-1 Decreases Oxidative Stress and Protects Against Abdominal Aortic Aneurysm Formation in Angiotensin II-Infused Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Miao Wang ◽  
Jane Stubbe ◽  
Eric Lee ◽  
Wenliang Song ◽  
Emanuela Ricciotti ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Angiotensin Ii ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Aortic Aneurysms ◽  
Ang Ii ◽  
Abdominal Aortic ◽  
Density Lipoprotein Receptor ◽  
The Impact

Microsomal (m) prostaglandin (PG) E 2 synthase(S)-1, an enzyme that catalyzes the isomerization of the cyclooxygenase (COX) product, PGH 2 , into PGE 2 , is a major source of PGE 2 in vivo . mPGES-1 deletion in mice was found to modulate experimentally evoked pain and inflammation and atherogenesis is retarded in mPGES-1 knockout (KO) mice. The impact of mPGES-1 deletion on formation of angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) was studied in mice lacking the low density lipoprotein receptor (LDLR −/− ). AngII infusion increased aortic macrophage recruitment and nitrotyrosine staining while upregulating both mPGES-1 and COX-2 and urinary excretion of the major metabolite of PGE 2 (PGE-M). Deletion of mPGES-1 decreased both the incidence and severity of AAA and depressed excretion of both PGE-M and 8, 12-iso-iPF 2a -VI, which reflects lipid peroxidation in vivo . While Ang II infusion augmented prostaglandin biosynthesis, deletion of mPGES-1 resulted in rediversion to PGD 2 , reflected by its major urinary metabolite. However, deletion of the PGD 2 receptor, DP1, did not affect AAA in Ang II infused LDLR −/− mice. These observations indicate that deletion of mPGES-1 protects against AAA formation by AngII in hyperlipidemic mice, perhaps by decreasing oxidative stress. Inhibition of mPGES-1 may represent an effective treatment to limit aneurysm occurrence and expansion.

Nascent and remnant lipoprotein turnover in rats: experimental design and simulation

1983 ◽  
Vol 245 (3) ◽  
pp. R386-R395
Author(s):  
N. Baker ◽  
H. J. Rostami ◽  
J. Elovson
Keyword(s):  
Fatty Acids ◽  
Molecular Weight ◽  
Simulation Analysis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Kinetic Behavior ◽  
Turnover Rates ◽  
Apoprotein B ◽  
Hydrolysis Of

We have attempted to predict the kinetic behavior of the complex very low-density lipoprotein (VLDL; d less than 1.006) fraction in blood plasma of rats in the steady state. Specifically we proposed a simple model with two different kinds of nascent VLDL particles derived from the liver, one containing apoprotein B (PI/II) [apoB(PI/II)], the high-molecular-weight apoB, and the other, apoprotein B (PIII) [apoB(PIII)], the low-molecular-weight apoB. Two other particles, the corresponding remnants derived from the nascent VLDL particles were also included. Then a number of feasible in vivo tracer experiments were considered in which VLDL labeled in the apoB and/or triglyceride (TG) moieties would be injected into recipient rats and the kinetic behavior of the various compartments predicted by simulation analysis. In addition the kinetic behavior of products such as free fatty acids formed during hydrolysis of labeled TG fatty acids and liver TG derived from labeled circulating remnants was considered. Both the relative sizes of nascent and remnant particles and the extent of average hydrolysis of nascent VLDL-TG (before formation of a remnant particle) were considered in our analysis. On the basis of these predictions we have suggested a number of experimental approaches that should be helpful in defining the relative pool sizes and the turnover rates of each kind of particle in vivo.

scholarly journals Quantification in vivo of the effects of different types of dietary fat on the loci of control involved in hepatic triacylglycerol secretion

1995 ◽  
Vol 308 (2) ◽  
pp. 537-542 ◽  
Author(s):  
A M B Moir ◽  
B S Park ◽  
V A Zammit
Keyword(s):  
Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Branch Points ◽  
Pharmacological Agents ◽  
Acid Diet ◽  
Fractional Rate ◽  
Selective Labelling ◽  
Hepatic Triacylglycerol

Polyunsaturated fatty acids (PUFA) have been suggested to exert their hypotriglyceridaemic effect through several possible mechanisms that would be expected to decrease the rate of hepatic very-low-density-lipoprotein-triacylglycerol secretion. We have quantified the role played in vivo by changes in the pattern of partitioning of (i) acyl-CoA between oxidation and esterification, (ii) diacylglycerol between synthesis of triacylglycerol and of the major phospholipids, and (iii) triacylglycerol between secretion and storage within the liver, in response to two dietary levels of n-6 and n-3 PUFA. In order to achieve this we used the technique of selective labelling of hepatic fatty acids in vivo. Compared with a predominantly saturated fatty acid diet, both n-6 and n-3 PUFA intake resulted in a decrease in the proportion of acyl moieties that were secreted by the liver, through an increased diversion of acyl-CoA towards oxidation and a lower fractional rate of secretion of newly synthesized triacylglycerol. In addition, a diet rich in n-3 fatty acids resulted not only in a greater magnitude of these effects but also in a doubling of the partitioning of diacylglycerol towards phospholipid labelling. It is shown that the overall 50% reduction achieved by fish oil feeding in the proportion of acyl groups that were secreted by the liver was distributed over all three branch points. The contribution of each of these adaptations was quantified. The application of such an approach, i.e. the localization and in vivo quantification of the importance of loci of control, in studies on dietary and pharmacological agents that affect lipaemia, is discussed.

scholarly journals Effect of Dehydroepiandrosterone Replacement on Lipoprotein Profile in Hypoadrenal Women

2009 ◽  
Vol 94 (3) ◽  
pp. 761-764 ◽  
Author(s):  
Manivannan Srinivasan ◽  
Brian A. Irving ◽  
Ketan Dhatariya ◽  
Katherine A. Klaus ◽  
Stacy J. Hartman ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Profile ◽  
Double Blind ◽  
Caucasian Women ◽  
Study Participants ◽  
The Impact ◽  
To Receive

Abstract Context: Levels of dehydroepiandrosterone (DHEA) and its sulfate form (DHEAS) are inversely associated with cardiovascular mortality in men but not women. Very little evidence is available on the impact of DHEA administration on lipoprotein profile in women. DHEAS levels are very low/undetectable in hypoadrenal women. Objective: The objective of the study was to determine the impact of DHEA replacement on lipoprotein profile in hypoadrenal women. Design and Setting: A double-blind, randomized, placebo-controlled, cross-over design study was conducted at the Mayo Clinic. Participants: Thirty-three hypoadrenal Caucasian women (mean ± sd; age 50.3 ± 15.2 yr, body mass index 26.6 ± 4.4 kg/m2) took part in the study. Intervention: Study participants were assigned to receive either a placebo or 50 mg/d of DHEA for 3 months each. Lipid levels and lipoprotein profile were analyzed using the Lipo Science Lipoprotein nuclear magnetic resonance system. Main Outcome Measures: Changes in various lipoprotein sizes and levels were measured. Results: The DHEA period had higher plasma DHEAS levels than during placebo (<0.3 ± 0.0 vs. 3.5 ± 1.3 nmol/liter, P < 0.001). DHEA replacement significantly reduced total cholesterol (20.0 vs. −22, P = 0.02) and high-density lipoprotein (HDL) levels (2.0 vs. −6.0, P = 0.006) and tends to reduce triglyceride and total low-density lipoprotein levels. Although, DHEA replacement had no effect on low-density lipoprotein particle size, it significantly reduced larger HDL particles and to modest extent small HDL particles. Conclusions: Our study findings showed that oral DHEA administration in hypoadrenal women results in an unfavorable lipoprotein profile. The results warrant long-term studies to determine the impact of DHEA replacement on cardiovascular risk.

Drug-induced dyslipoproteinemia: a report of two cases.

1980 ◽  
Vol 26 (1) ◽  
pp. 163-168
Author(s):  
H K Naito ◽  
M C McHenry ◽  
L A Lewis
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serum Lipoproteins ◽  
Drug Induced ◽  
Drug Induction ◽  
Secondary Form ◽  
Species Specific

Abstract We describe two cases of atypical dyslipoproteinemia due to drug-induction. This secondary form of lipoprotein abnormality is unique because the newly available drug, miconazole, apparently directly delipidated the alpha-lipoproteins in the bloodstream. On closer study we found that the delipidation was caused by the vehicle rather than the fungicide--more specifically, only by the polyethoxylated castor oil in the vehicle. It affects serum lipoproteins both in vitro and in vivo, and the effect is species-specific. In vitro studies indicate that it preferentially delipidates high-density lipoprotein rather than low-density lipoprotein. Because its effects on the serum lipoproteins of rats resemble those on man, and because aortic lesions were produced in rats injected daily (90 mL/L) with this substance, caution is indicated in long-term use of drugs containing this chemical component in the vehicle.

Identification of the hemangioblast in postnatal life

Blood ◽  
2002 ◽  
Vol 100 (9) ◽  
pp. 3203-3208 ◽  
Author(s):  
Elvira Pelosi ◽  
Mauro Valtieri ◽  
Simona Coppola ◽  
Rosanna Botta ◽  
Marco Gabbianelli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Low Density Lipoprotein ◽  
Cell Subset ◽  
Growth Factor Receptor ◽  
Density Lipoprotein ◽  
Postnatal Life ◽  
Proliferative Potential

Abstract Postnatal CD34+ cells expressing vascular endothelial growth factor receptor 2 (KDR) generate hematopoietic or endothelial progeny in different in vitro and in vivo assays. Hypothetically, CD34+KDR+ cells may comprise hemangioblasts bipotent for both lineages. This hypothesis is consistent with 2 series of experiments. In the first series, in clonogenic culture permissive for hematopoietic and endothelial cell growth, CD34+KDR+ cells generate large hemato-endothelial (Hem-End) colonies (5% of seeded cells), whereas CD34+KDR− cells do not. Limiting-dilution analysis indicates that Hem-End colonies are clonally generated by single hemangioblasts. Sibling cells generated by a hemangioblast, replated in unicellular culture, produce either hematopoietic or Hem-End colonies, depending on the specific culture conditions. Identification of endothelial cells was based on the expression of VE-cadherin and endothelial markers and with lack of CD45 and hematopoietic molecules, as evaluated by immunofluorescence, immunocytochemistry, and reverse transcription–polymerase chain reaction. Furthermore, endothelial cells were functionally identified using low-density lipoprotein (LDL) uptake and tube-formation assays. In the second series, to evaluate the self-renewal capacity of hemangioblasts, single CD34+KDR+ cells were grown in 3-month extended long-term culture (ELTC) through 3 serial culture rounds—that is, blast cells generated in unicellular ELTC were reseeded for a subsequent round of unicellular ELTC. After 9 months, 10% blasts from tertiary ELTC functioned as hemangioblasts and generated macroscopic Hem-End colonies in clonogenic culture. These studies identified postnatal hemangioblasts in a CD34+KDR+ cell subset, endowed with long-term proliferative potential and bilineage differentiation capacity. Although exceedingly rare, hemangioblasts may represent the lifetime source/reservoir for primitive hematopoietic and endothelial progenitors.

scholarly journals The Cholesterol-Lowering Effect of Alisol Acetates Based on HMG-CoA Reductase and Its Molecular Mechanism

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Fei Xu ◽  
Hui Yu ◽  
Cai Lu ◽  
Jun Chen ◽  
Wei Gu
Keyword(s):  
Molecular Simulation ◽  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
The Impact

This study measured the impact of alisol B 23-acetate and alisol A 24-acetate, the main active ingredients of the traditional Chinese medicine Alismatis rhizoma, on total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), and low density lipoprotein-cholesterol (LDL-C) levels of hyperlipidemic mice. The binding of alisol B 23-acetate and alisol A 24-acetate to the key enzyme involved in the metabolism of TC, 3-hydroxy-3-methylglutary-coenzyme A (HMG-CoA) reductase, was studied using the reagent kit method and the western blotting technique combined with a molecular simulation technique. According to the results, alisol acetates significantly lower the TC, TG, and LDL-C concentrations of hyperlipidemic mice, while raising HDL-C concentrations. Alisol acetates lower HMG-CoA reductase activity in a dose-dependent fashion, both in vivo and in vitro. Neither of these alisol acetates significantly lower the protein expression of HMG-CoA. This suggests that alisol acetates lower the TC level via inhibiting the activity of HMG-CoA reductase by its prototype drug, which may exhibit an inhibition effect via directly and competitively binding to HMG-CoA. The side chain of the alisol acetate was the steering group via molecular simulation.

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