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1.
Annu Rev Med ; 72: 431-446, 2021 01 27.
Article in English | MEDLINE | ID: mdl-33217249

ABSTRACT

Although numerous trials have convincingly shown benefits of statin therapy in both primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD), most showed relative risk reductions of 25-40%, and thus many individuals continue to have ASCVD events despite statin therapy. Substantial progress has been made in developing therapies that address the residual risk for ASCVD despite statin therapy. In this review, we summarize progress of currently available therapies along with therapies under development that further reduce low-density lipoprotein cholesterol and apolipoprotein B-containing lipoproteins, reduce lipoprotein(a), reduce ASCVD events in patients with high triglycerides, and directly target inflammation to reduce ASCVD risk.


Subject(s)
Cardiovascular Diseases/prevention & control , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Inflammation/drug therapy , Lipoproteins/blood , Primary Prevention/methods , Secondary Prevention/methods , Biomarkers/blood , Cardiovascular Diseases/blood , Humans , Inflammation/blood , Lipoproteins/drug effects
2.
Br J Nutr ; 125(2): 147-160, 2021 01 28.
Article in English | MEDLINE | ID: mdl-32660657

ABSTRACT

Mycoprotein consumption has been shown to improve acute postprandial glycaemic control and decrease circulating cholesterol concentrations. We investigated the impact of incorporating mycoprotein into the diet on insulin sensitivity (IS), glycaemic control and plasma lipoprotein composition. Twenty healthy adults participated in a randomised, parallel-group trial in which they consumed a 7 d fully controlled diet where lunch and dinner contained either meat/fish (control group, CON) or mycoprotein (MYC) as the primary source of dietary protein. Oral glucose tolerance tests were performed pre- and post-intervention, and 24 h continuous blood glucose monitoring was applied throughout. Fasting plasma samples were obtained pre- and post-intervention and were analysed using quantitative, targeted NMR-based metabonomics. There were no changes within or between groups in blood glucose or serum insulin responses, nor in IS or 24 h glycaemic profiles. No differences between groups were found for 171 of the 224 metabonomic targets. Forty-five lipid concentrations of different lipoprotein fractions (VLDL, LDL, intermediate-density lipoprotein and HDL) remained unchanged in CON but showed a coordinated decrease (7-27 %; all P < 0·05) in MYC. Total plasma cholesterol, free cholesterol, LDL-cholesterol, HDL2-cholesterol, DHA and n-3 fatty acids decreased to a larger degree in MYC (14-19 %) compared with CON (3-11 %; P < 0·05). Substituting meat/fish for mycoprotein twice daily for 1 week did not modulate whole-body IS or glycaemic control but resulted in changes to plasma lipid composition, the latter primarily consisting of a coordinated reduction in circulating cholesterol-containing lipoproteins.


Subject(s)
Blood Glucose/drug effects , Dietary Proteins/pharmacology , Fungal Proteins/pharmacology , Insulin Resistance , Lipoproteins/drug effects , Blood Glucose Self-Monitoring , Cholesterol/blood , Fasting/blood , Female , Fish Proteins, Dietary/pharmacology , Glucose Tolerance Test , Glycemic Control , Healthy Volunteers , Humans , Insulin/blood , Lipidomics , Male , Meat Proteins/pharmacology , Postprandial Period/drug effects , Young Adult
3.
Cardiovasc Drugs Ther ; 35(3): 677-690, 2021 06.
Article in English | MEDLINE | ID: mdl-33710501

ABSTRACT

OBJECTIVE: Despite aggressive reduction of low-density lipoprotein cholesterol (LDL-C), there is a residual risk of cardiovascular disease (CVD). Hypertriglyceridemia is known to be associated with increased CVD risk, independently of LDL-C. Triglycerides are one component of the heterogenous class of triglyceride-rich lipoproteins (TGRLs). METHODS/RESULTS: Growing evidence from biology, epidemiology, and genetics supports the contribution of TGRLs to the development of CVD via a number of mechanisms, including through proinflammatory, proapoptotic, and procoagulant pathways. CONCLUSION: New genetics-guided pharmacotherapies to reduce levels of triglycerides and TGRLs and thus reduce risk of CVD have been developed and will be discussed here.


Subject(s)
Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/physiopathology , Lipoproteins/drug effects , Lipoproteins/metabolism , Triglycerides/metabolism , Atherosclerosis/genetics , Atherosclerosis/physiopathology , Cardiovascular Diseases/genetics , Chylomicrons/metabolism , Genetic Predisposition to Disease , Heart Disease Risk Factors , Humans , Inflammation Mediators/metabolism , Lipoprotein Lipase/metabolism , Risk Reduction Behavior
4.
Lancet ; 394(10199): 697-708, 2019 Aug 24.
Article in English | MEDLINE | ID: mdl-31448741

ABSTRACT

Atherosclerosis and its clinical manifestation as ischaemic heart disease remains a considerable health burden. Given that many factors contribute to ischaemic heart disease, a multifactorial approach to prevention is recommended, starting with lifestyle advice, smoking cessation, and control of known cardiovascular risk factors, such as blood pressure and lipids. Within the lipid profile, the principal target is lowering LDL cholesterol, firstly with lifestyle interventions and subsequently with pharmacological therapy. Statins are the recommended first-line pharmacological treatment. Some individuals might require further lowering of LDL cholesterol or be unable to tolerate statins. Additional therapies targeting different pathways in cholesterol metabolism are now available, ranging from small molecules taken orally, to injectable therapies. Examples include ezetimibe, which targets Niemann-Pick C1-like protein, and monoclonal antibodies that target PCSK9. Phase 3 trials have also been completed for bempedoic acid (targeting ATP-citrate lyase) and inclisiran (an interference RNA-based therapeutic targeting hepatic PCSK9 synthesis). In addition to LDL cholesterol, mendelian randomisation studies support a causal role for lipoprotein(a) and triglycerides in ischaemic heart disease. In this Series paper, we appraise currently available and emerging therapies for lowering LDL cholesterol, lipoprotein(a), and triglycerides for prevention of ischaemic heart disease.


Subject(s)
Antibodies, Monoclonal/pharmacology , Anticholesteremic Agents/pharmacology , Cholesterol, LDL/drug effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Lipoproteins/drug effects , Myocardial Ischemia/prevention & control , Cholesterol, LDL/blood , Humans , Lipoproteins/blood , Myocardial Ischemia/drug therapy , Proprotein Convertase 9 , Risk Factors , Triglycerides/blood
5.
Pediatr Nephrol ; 35(9): 1601-1619, 2020 09.
Article in English | MEDLINE | ID: mdl-31302760

ABSTRACT

Children with steroid-resistant nephrotic syndrome (SRNS) are exposed to multiple cardiovascular risk factors predisposing them to accelerated atherosclerosis. This risk is negligible in steroid-sensitive nephrotic syndrome, but a substantial proportion of children with SRNS progress to chronic kidney disease, exacerbating the already existing cardiovascular risk. While dyslipidemia is an established modifiable risk factor for cardiovascular disease in adults with NS, it is uncertain to what extent analogous risks exist for children. There is increasing evidence of accelerated atherosclerosis in children with persistently high lipid levels, especially in refractory NS. Abnormalities of lipid metabolism in NS include hypertriglyceridemia and hypercholesterolemia due to elevated apolipoprotein B-containing lipoproteins, decreased lipoprotein lipase and hepatic lipase activity, increased hepatic PCSK9 levels, and reduced hepatic uptake of high-density lipoprotein. Existing guidelines for the management of dyslipidemia in children may be adapted to target lower lipid levels in children with NS, but they will most likely require both lifestyle modifications and pharmacological therapy. While there is a lack of data from randomized controlled trials in children with NS demonstrating the benefit of lipid-lowering drugs, therapies including statins, bile acid sequestrants, fibrates, ezetimibe, and LDL apheresis have all been suggested and/or utilized. However, concerns with the use of lipid-lowering drugs in children include unclear side effect profiles and unknown long-term impacts on neurological development and puberty. The recent introduction of anti-PCSK9 monoclonal antibodies and other therapies targeted to the molecular mechanisms of lipid transport disrupted in NS holds promise for the future treatment of dyslipidemia in NS.


Subject(s)
Dyslipidemias/physiopathology , Nephrotic Syndrome/physiopathology , Adolescent , Adult , Atherosclerosis/etiology , Atherosclerosis/prevention & control , Child , Dyslipidemias/drug therapy , Dyslipidemias/etiology , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Lipoproteins/blood , Lipoproteins/drug effects , Nephrotic Syndrome/complications , Nephrotic Syndrome/drug therapy , Risk Factors , Young Adult
6.
J Periodontal Res ; 53(3): 403-413, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29341140

ABSTRACT

BACKGROUND AND OBJECTIVE: Several studies have shown an association between periodontitis and cardiovascular disease (CVD). Atherosclerosis is the major cause of CVD, and a key event in the development of atherosclerosis is accumulation of lipoproteins within the arterial wall. Bacteria are the primary etiologic agents in periodontitis and Porphyromonas gingivalis is the major pathogen in the disease. Several studies support a role of modified low-density lipoprotein (LDL) in atherogenesis; however, the pathogenic stimuli that induce the changes and the mechanisms by which this occur are unknown. This study aims to identify alterations in plasma lipoproteins induced by the periodontopathic species of bacterium, P. gingivalis, in vitro. MATERIAL AND METHODS: Plasma lipoproteins were isolated from whole blood treated with wild-type and gingipain-mutant (lacking either the Rgp- or Kgp gingipains) P. gingivalis by density/gradient-ultracentrifugation and were studied using 2-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization mass spectrometry. Porphyromonas gingivalis-induced lipid peroxidation and antioxidant levels were measured by thiobarbituric acid-reactive substances and antioxidant assay kits, respectively, and lumiaggregometry was used for measurement of reactive oxygen species (ROS) and aggregation. RESULTS: Porphyromonas gingivalis exerted substantial proteolytic effects on the lipoproteins. The Rgp gingipains were responsible for producing 2 apoE fragments, as well as 2 apoB-100 fragments, in LDL, and the Kgp gingipain produced an unidentified fragment in high-density lipoproteins. Porphyromonas gingivalis and its different gingipain variants induced ROS and consumed antioxidants. Both the Rgp and Kgp gingipains were involved in inducing lipid peroxidation. CONCLUSION: Porphyromonas gingivalis has the potential to change the expression of lipoproteins in blood, which may represent a crucial link between periodontitis and CVD.


Subject(s)
Adhesins, Bacterial/metabolism , Cysteine Endopeptidases/metabolism , Cysteine Endopeptidases/pharmacokinetics , Lipoproteins/drug effects , Lipoproteins/metabolism , Periodontitis/metabolism , Porphyromonas gingivalis/metabolism , Adhesins, Bacterial/blood , Adhesins, Bacterial/genetics , Antioxidants/analysis , Apolipoprotein A-I/metabolism , Apolipoprotein B-100/metabolism , Cysteine Endopeptidases/blood , Cysteine Endopeptidases/genetics , Gingipain Cysteine Endopeptidases , Humans , Lipid Peroxidation , Lipoproteins/blood , Lipoproteins, HDL/blood , Lipoproteins, HDL/metabolism , Lipoproteins, LDL/blood , Lipoproteins, LDL/drug effects , Lipoproteins, LDL/metabolism , Methionine/metabolism , Periodontitis/microbiology , Porphyromonas gingivalis/pathogenicity , Reactive Oxygen Species/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
7.
Pediatr Int ; 60(9): 839-843, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29931721

ABSTRACT

BACKGROUND: Lipid emulsions given i.v. are normally rapidly metabolized by apoprotein recruited from high-density lipoprotein (HDL) particles in the blood. Very low-birthweight infants (VLBWI), however, have a low rate of lipid clearance from the blood, and therefore lipid emulsions must be given carefully to minimize the risk of hyperlipidemia. The purpose of this study was to evaluate the influence of i.v. lipid emulsion on lipoprotein subclass profile in VLBWI during the early postnatal period. METHODS: Forty-six VLBWI who had been given different doses of lipid emulsion in the first few days after birth were enrolled in the present study. Triglyceride and cholesterol content of each lipoprotein subclass was measured at 3 weeks after birth, and their correlation with the total dose of lipid emulsion was calculated. RESULTS: There was no correlation between the total dose of lipid emulsion and the triglyceride and cholesterol content in any subclasses of very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL). There was a significant negative correlation between the total dose of lipid emulsion and the triglyceride content in very large (P < 0.05, r = -0.32), large (P < 0.01, r = -0.47) and medium HDL (P < 0.05, r = -0.34) particles; and the cholesterol content in large (P < 0.01, r = -0.47) and medium HDL (P < 0.01, r = -0.4) particles. CONCLUSION: Lipid emulsion influenced the triglyceride and cholesterol content of HDL particles in VLBWI, suggesting that lipid emulsion can affect lipid metabolism in this infant population in the early postnatal period.


Subject(s)
Cholesterol/blood , Fat Emulsions, Intravenous/adverse effects , Lipoproteins/drug effects , Triglycerides/blood , Female , Humans , Infant, Newborn , Infant, Premature , Infant, Very Low Birth Weight , Lipoproteins/blood , Male
8.
An Acad Bras Cienc ; 90(2 suppl 1): 2299-2310, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29947666

ABSTRACT

PsaA (pneumococcal surface antigen A) is a S. pneumoniae virulence factor that belongs to the metal transport system. The Manganese PsaA binding has been associated with oxidative stress resistance becoming a pivotal element in the bacteria virulence. It has been shown that Zinc inhibits the Manganese acquisition and promotes bacteria toxicity. We have performed a PsaA conformational analysis both in the presence (Zn-rPsaA) and in the absence of Zinc (free-rPsaA). We performed experiments in the presence of different Zinc concentrations to determine the metal minimum concentration which induced a conformational change. The protein in free and Zn-binding condition was also studied in pH ranging 2.6-8.0 and in temperature ranging 25oC-85oC. pH experiments showed a decrease of fluorescence intensity only in acidic medium. Analysis of the heat-induced denaturation demonstrated that Zinc-binding promoted an increase in melting temperature from 55oC (free-rPsaA) to 78.8oC (Zn-rPsaA) according to fluorescence measurements. In addition, the rPsaA stabilization by Zinc was verified through analysis of urea and guanidine hydrochloride denaturation. Data showed that Zinc promoted an increase in the rPsaA stability and its removal by EDTA can lead to a PsaA intermediate conformation. These findings can be considered in the development of vaccines containing PsaA as antigen.


Subject(s)
Adhesins, Bacterial/chemistry , Antigens, Surface/chemistry , Lipoproteins/chemistry , Protein Conformation/drug effects , Streptococcus pneumoniae/chemistry , Zinc/pharmacology , Adhesins, Bacterial/drug effects , Lipoproteins/drug effects , Spectrometry, Fluorescence , Temperature
10.
Diabetes Obes Metab ; 18(9): 936-40, 2016 09.
Article in English | MEDLINE | ID: mdl-27109453

ABSTRACT

The bile acid analogue obeticholic acid (OCA) is a selective farnesoid X receptor (FXR) agonist in development for treatment of several chronic liver diseases. FXR activation regulates lipoprotein homeostasis. The effects of OCA on cholesterol and lipoprotein metabolism in healthy individuals were assessed. Two phase I studies were conducted to evaluate the effects of repeated oral doses of 5, 10 or 25 mg OCA on lipid variables after 14 or 20 days of consecutive administration in 68 healthy adults. Changes in HDL and LDL cholesterol levels were examined, in addition to nuclear magnetic resonance analysis of particle sizes and sub-fraction concentrations. OCA elicited changes in circulating cholesterol and particle size of LDL and HDL. OCA decreased HDL cholesterol and increased LDL cholesterol, independently of dose. HDL particle concentrations declined as a result of a reduction in medium and small HDL. Total LDL particle concentrations increased because of an increase in large LDL particles. Changes in lipoprotein metabolism attributable to OCA in healthy individuals were found to be consistent with previously reported changes in patients receiving OCA with non-alcoholic fatty liver disease or non-alcoholic steatohepatitis.


Subject(s)
Apolipoprotein A-I/drug effects , Apolipoproteins B/drug effects , Chenodeoxycholic Acid/analogs & derivatives , Cholesterol, HDL/drug effects , Cholesterol, LDL/drug effects , Receptors, Cytoplasmic and Nuclear/agonists , Adult , Apolipoprotein A-I/metabolism , Apolipoproteins B/metabolism , Chenodeoxycholic Acid/administration & dosage , Chenodeoxycholic Acid/pharmacology , Cholesterol, HDL/metabolism , Cholesterol, LDL/metabolism , Cholesterol, VLDL/drug effects , Cholesterol, VLDL/metabolism , Female , Healthy Volunteers , Humans , Lipoproteins/drug effects , Lipoproteins/metabolism , Magnetic Resonance Spectroscopy , Male , Triglycerides/metabolism
11.
Arterioscler Thromb Vasc Biol ; 35(5): 1092-100, 2015 May.
Article in English | MEDLINE | ID: mdl-25675997

ABSTRACT

OBJECTIVE: Intestinal overproduction of atherogenic chylomicron particles postprandially is an important component of diabetic dyslipidemia in insulin-resistant states. In addition to enhancing insulin secretion, peripheral glucagon-like peptide-1 (GLP-1) receptor stimulation has the added benefit of reducing this chylomicron overproduction in patients with type 2 diabetes mellitus. Given the presence of central GLP-1 receptors and GLP-1-producing neurons, we assessed whether central GLP-1 exerts an integral layer of neuronal control during the production of these potentially atherogenic particles. APPROACH AND RESULTS: Postprandial production of triglyceride-rich lipoproteins was assessed in Syrian hamsters administered a single intracerebroventricular injection of the GLP-1 receptor agonist exendin-4. Intracerebroventricular exendin-4 reduced triglyceride-rich lipoprotein-triglyceride and -apolipoprotein B48 accumulation relative to vehicle-treated controls. This was mirrored by intracerebroventricular MK-0626, an inhibitor of endogenous GLP-1 degradation, and prevented by central exendin9-39, a GLP-1 receptor antagonist. The effects of intracerebroventricular exendin-4 were also lost during peripheral adrenergic receptor and central melanocortin-4 receptor inhibition, achieved using intravenous propranolol and phentolamine and intracerebroventricular HS014, respectively. However, central exendin9-39 did not preclude the effects of peripheral exendin-4 treatment on chylomicron output. CONCLUSIONS: Central GLP-1 is a novel regulator of chylomicron production via melanocortin-4 receptors. Our findings point to the relative importance of central accessibility of GLP-1-based therapies and compel further studies examining the status of this brain-gut axis in the development of diabetic dyslipidemia and chylomicron overproduction.


Subject(s)
Central Nervous System/metabolism , Diabetes Mellitus, Type 2/metabolism , Glucagon-Like Peptide 1/metabolism , Lipoproteins/metabolism , Peptides/pharmacology , Receptors, Glucagon/metabolism , Venoms/pharmacology , Animals , Central Nervous System/drug effects , Chylomicrons/drug effects , Chylomicrons/metabolism , Cricetinae , Diabetes Mellitus, Type 2/physiopathology , Disease Models, Animal , Exenatide , Glucagon-Like Peptide-1 Receptor , Intestinal Mucosa/metabolism , Intestines/innervation , Lipid Metabolism/drug effects , Lipoproteins/drug effects , Random Allocation
12.
Circ Res ; 112(10): 1345-54, 2013 May 10.
Article in English | MEDLINE | ID: mdl-23501697

ABSTRACT

RATIONALE: Macrophage accumulation in adipose tissue associates with insulin resistance and increased cardiovascular disease risk. We previously have shown that generation of reactive oxygen species and monocyte chemotactic factors after exposure of adipocytes to saturated fatty acids, such as palmitate, occurs via translocation of NADPH oxidase 4 into lipid rafts (LRs). The anti-inflammatory effects of apolipoprotein AI (apoAI) and high-density lipoprotein (HDL) on macrophages and endothelial cells seem to occur via cholesterol depletion of LRs. However, little is known concerning anti-inflammatory effects of HDL and apoAI on adipocytes. OBJECTIVE: To determine whether apoAI and HDL inhibit inflammation in adipocytes and adipose tissue, and whether this is dependent on LRs. METHODS AND RESULTS: In 3T3L-1 adipocytes, apoAI, HDL, and methyl-ß-cyclodextrin inhibited chemotactic factor expression. ApoAI and HDL also disrupted LRs, reduced plasma membrane cholesterol content, inhibited NADPH oxidase 4 translocation into LRs, and reduced palmitate-induced reactive oxygen species generation and monocyte chemotactic factor expression. Silencing ATP-binding cassette A-1 abrogated the effect of apoAI, but not HDL, whereas silencing ATP-binding cassette G-1 or scavenger receptor B-1 abrogated the effect of HDL but not apoAI. In vivo, apoAI transgenic mice fed a high-fat, high-sucrose, cholesterol-containing diet showed reduced chemotactic factor and proinflammatory cytokine expression and reduced macrophage accumulation in adipose tissue. CONCLUSIONS: ApoAI and HDL have anti-inflammatory effects in adipocytes and adipose tissue similar to their effects in other cell types. These effects are consistent with disruption and removal of cholesterol from LRs, which are regulated by cholesterol transporters, such as ATP-binding cassette A-1, ATP-binding cassette G-1, and scavenger receptor B-1.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Adipocytes/metabolism , Apolipoprotein A-I/metabolism , Cholesterol/metabolism , Lipoproteins, HDL/metabolism , Lipoproteins/metabolism , Scavenger Receptors, Class B/metabolism , 3T3-L1 Cells , ATP Binding Cassette Transporter 1 , ATP Binding Cassette Transporter, Subfamily G, Member 1 , ATP-Binding Cassette Transporters/drug effects , Adipocytes/cytology , Adipocytes/drug effects , Animals , Anti-Inflammatory Agents/pharmacology , Apolipoprotein A-I/genetics , Apolipoprotein A-I/pharmacology , Biological Transport/physiology , Cells, Cultured , Disease Models, Animal , Humans , In Vitro Techniques , Inflammation/metabolism , Lipoproteins/drug effects , Lipoproteins, HDL/pharmacology , Male , Membrane Microdomains/drug effects , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , RNA, Small Interfering/pharmacology , Reactive Oxygen Species/metabolism , Receptors, LDL/deficiency , Receptors, LDL/genetics , Receptors, LDL/metabolism , Scavenger Receptors, Class B/drug effects
13.
Vnitr Lek ; 61(5): 398-400, 2015 May.
Article in Cs | MEDLINE | ID: mdl-26075846

ABSTRACT

Despite significant improvement in the diagnosis and therapy of cardiovascular diseases their global risk and proportion of their clinical forms remains very high. Still the large part of the patients cannot reach the estimated target lipid levels despite statin therapy. Low adherence to preventive programmes with physical training and diet leads to progression of the pathological process of atherothrombosis. One possible therapeutic approach could be the combined hypolipidemic treatment. In this context we followed-up the size of lipoprotein particles among very high risk patients on statin monotherapy, where phytosterole was added. Lipoprotein profile among very high risk patients during combined therapy lead to improvement and therefore may contribute to lowering of their residual risk.


Subject(s)
Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Lipoproteins/blood , Phytosterols/therapeutic use , Cardiovascular Diseases/blood , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Drug Therapy, Combination , Global Health , Humans , Incidence , Lipoproteins/drug effects , Risk Factors
14.
Arterioscler Thromb Vasc Biol ; 33(1): 24-33, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23117655

ABSTRACT

OBJECTIVE: Atherosclerosis is characterized as a chronic inflammatory condition that involves cholesterol deposition in arteries. Together with scavenger receptor B1 (SR-B1), the ATP-binding cassette transporters ABCA1 and ABCG1 are the major components of macrophage cholesterol efflux. Recent studies have shown that low-grade inflammation plays a distinct regulatory role in the expression of SR-B1 and ABCA1/ABCG1. However, the mechanisms linking low-grade inflammation and cholesterol accumulation are poorly understood. METHODS AND RESULTS: Using primary bone-marrow-derived macrophages, we demonstrate that subclinical low-dose lipopolysaccharide potently reduces the expression of SR-B1 and ABCA1/ABCG1, as well as cholesterol efflux from macrophages through interleukin-1 receptor-associated kinase 1 and Toll-interacting-protein. Low-dose lipopolysaccharide downregulates the nuclear levels of retinoic acid receptor-α, leading to their reduced binding to the promoters of SR-B1 and ABCA1/ABCG1. We observe that glycogen synthase kinase 3ß activation by low-dose lipopolysaccharide through interleukin-1 receptor-associated kinase 1 and Toll-interacting-protein is responsible for reduced levels of retinoic acid receptor-α, and reduced expression of SR-B1 and ABCA1/ABCG1. Interleukin-1 receptor-associated kinase M, however, counteracts the function of interleukin-1 receptor associated kinase 1. CONCLUSIONS: Collectively, our data reveal a novel intracellular network regulated by low-dose endotoxemia that disrupts cholesterol efflux from macrophages and leads to the pathogenesis of atherosclerosis.


Subject(s)
ATP-Binding Cassette Transporters/drug effects , Cholesterol/metabolism , Endotoxins/pharmacology , Lipoproteins/drug effects , Macrophages/drug effects , Scavenger Receptors, Class B/drug effects , ATP Binding Cassette Transporter 1 , ATP Binding Cassette Transporter, Subfamily G, Member 1 , ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Animals , Apolipoprotein A-I/metabolism , Atherosclerosis/chemically induced , Atherosclerosis/metabolism , Binding Sites , Cells, Cultured , Cholesterol, HDL/metabolism , Dose-Response Relationship, Drug , Down-Regulation , Endotoxins/toxicity , Foam Cells/drug effects , Foam Cells/metabolism , Glycogen Synthase Kinase 3/genetics , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Interleukin-1 Receptor-Associated Kinases/genetics , Interleukin-1 Receptor-Associated Kinases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Lipoproteins/genetics , Lipoproteins/metabolism , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Promoter Regions, Genetic , Receptors, Retinoic Acid/metabolism , Retinoic Acid Receptor alpha , Scavenger Receptors, Class B/genetics , Scavenger Receptors, Class B/metabolism
15.
Curr Cardiol Rep ; 16(7): 506, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24890766

ABSTRACT

Statins are safe, efficacious and the cornerstone of cardiovascular disease prevention strategies. A number of add-on therapies with complementary actions on the plasma lipid profile have been tested in large scale trials to see if they give incremental benefit. In particular, the 'HDL hypothesis' - that raising this lipoprotein will promote reverse cholesterol transport and reduce cardiovascular risk - has been examined using drugs such as dalcetrapib and niacin. So far, results have been negative, and this has raised questions over the nature of the association of HDL with atherosclerosis, and whether statins reduce cardiovascular risk through multiple mechanisms. There is still an unmet clinical need especially in those patients who cannot tolerate statins and those with severe hyperlipidemia, and so new therapeutic approaches have been developed. These show significant promise in terms of LDL-cholesterol lowering but significant challenges include cost, route of administration (subcutaneous injection) and side effects. Testing in major outcome trials will be required to demonstrate their clinical utility.


Subject(s)
Cardiovascular Diseases/prevention & control , Dyslipidemias/drug therapy , Hypolipidemic Agents/therapeutic use , Lipoproteins/drug effects , Dyslipidemias/complications , Humans , Hypolipidemic Agents/adverse effects , Lipoproteins/blood , Treatment Outcome
16.
Hepatology ; 56(5): 1828-37, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22829162

ABSTRACT

UNLABELLED: Secretion of cholesterol into bile is important for the elimination of cholesterol from the body. Thyroid hormone (TH) increases biliary cholesterol secretion and hepatic gene expression of adenosine triphosphate (ATP)-binding cassette, subfamily G (WHITE), member 5 (ABCG5) and ATP-binding cassette, subfamily G (WHITE), member 8 (ABCG8), two half-transporters that act as a heterodimeric complex promoting sterol secretion. In addition, nuclear liver x receptor-alpha (LXRa), also regulated by TH, induces gene expression of ABCG5/G8. We here investigated if the TH-induced stimulation of biliary cholesterol secretion is mediated by the ABCG5/G8 complex in vivo, and if so, whether LXRa is involved. Mice homozygous for disruption of Abcg5 (Abcg5(-/-) ) or Lxra (Lxra(-/-) ) and their wild-type counterparts were treated with triiodothyronine (T3) for 14 days and compared to untreated mice of corresponding genetic backgrounds. Bile was collected by gallbladder cannulation, and liver samples were analyzed for gene expression levels. Basal biliary cholesterol secretion in Abcg5(-/-) mice was 72% lower than in Abcg5(+/+) mice. T3 treatment increased cholesterol secretion 3.1-fold in Abcg5(+/+) mice, whereas this response was severely blunted in Abcg5(-/-) mice. In contrast, biliary cholesterol secretion in T3-treated Lxra(+/+) and Lxra(-/-) mice was increased 3.5- and 2.6-fold, respectively, and did not differ significantly. CONCLUSIONS: TH-induced secretion of cholesterol into bile is largely dependent on an intact ABCG5/G8 transporter complex, whereas LXRa is not critical for this effect.


Subject(s)
ATP-Binding Cassette Transporters/genetics , Bile/metabolism , Cholesterol/metabolism , Gene Expression/drug effects , Lipoproteins/genetics , Liver/metabolism , Orphan Nuclear Receptors/genetics , RNA/metabolism , ATP Binding Cassette Transporter, Subfamily G, Member 5 , ATP Binding Cassette Transporter, Subfamily G, Member 8 , ATP-Binding Cassette Transporters/drug effects , Analysis of Variance , Animals , Bile Acids and Salts/metabolism , Cholesterol 7-alpha-Hydroxylase/genetics , Homozygote , Hydroxymethylglutaryl CoA Reductases/genetics , Lipoproteins/drug effects , Liver X Receptors , Male , Mice , Orphan Nuclear Receptors/drug effects , Phospholipids/analysis , Receptors, LDL/genetics , Triiodothyronine/pharmacology
17.
Arterioscler Thromb Vasc Biol ; 32(2): 427-33, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22116096

ABSTRACT

OBJECTIVE: Factor VII-activating protease (FSAP) activates both factor VII and pro-urokinase and inhibits platelet-derived growth factor-BB, thus regulating hemostasis- and remodeling-associated processes in the vasculature. A genetic variant of FSAP (Marburg I polymorphism) results in low enzymatic activity and is associated with an enhanced risk of carotid stenosis and stroke. We postulate that there are additional substrates for FSAP that will help to explain its role in vascular biology and have searched for such a substrate. METHODS AND RESULTS: Using screening procedures to determine the influence of FSAP on various hemostasis-related processes on endothelial cells, we discovered that FSAP inhibited tissue factor pathway inhibitor (TFPI), a major anticoagulant secreted by these cells. Proteolytic degradation of TFPI by FSAP could also be demonstrated by Western blotting, and the exact cleavage sites were determined by N-terminal sequencing. The Marburg I variant of FSAP had a diminished ability to inhibit TFPI. A monoclonal antibody to FSAP that specifically inhibited FSAP binding to TFPI reversed the inhibitory effect of FSAP on TFPI. CONCLUSIONS: The identification of TFPI as a sensitive substrate for FSAP increases our understanding of its role in regulating hemostasis and proliferative remodeling events in the vasculature.


Subject(s)
Endothelium, Vascular/drug effects , Lipoproteins/antagonists & inhibitors , Proteolysis/drug effects , Serine Endopeptidases/pharmacology , Antibodies, Monoclonal/pharmacology , Cell Proliferation , Cells, Cultured , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Hemostasis/physiology , Humans , Lipoproteins/drug effects , Serine Endopeptidases/drug effects , Serine Endopeptidases/immunology
18.
Toxicol Appl Pharmacol ; 251(3): 201-8, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21195106

ABSTRACT

Gemfibrozil (GEM) is a fibrate drug consistently found in effluents from sewage treatment plants. This study characterizes the pharmacological effects of GEM on the plasma lipoproteins of rainbow trout (Oncorhynchus mykiss). Our goals were to quantify the impact of the drug on: 1) lipid constituents of lipoproteins (phospholipids (PL), triacylglycerol (TAG), and cholesterol), 2) lipoprotein classes (high, low and very low density lipoproteins), and 3) fatty acid composition of lipoproteins. Potential mechanisms of GEM action were investigated by measuring lipoprotein lipase activity (LPL) and the hepatic gene expression of LPL and of the peroxisome proliferator-activated receptor (PPAR) α, ß, and γ isoforms. GEM treatment resulted in decreased plasma lipoprotein levels (-29%) and a reduced size of all lipoprotein classes (lower PL:TAG ratios). However, the increase in HDL-cholesterol elicited by GEM in humans failed to be observed in trout. Therefore, HDL-cholesterol cannot be used to assess the impact of the drug on fish. GEM also modified lipoprotein composition by reducing the abundance of long-chain n-3 fatty acids, thereby potentially reducing the nutritional quality of exposed fish. The relative gene expression of LPL was increased, but the activity of the enzyme was not, and we found no evidence for the activation of PPAR pathways. The depressing effects of GEM on fish lipoproteins demonstrated here may be a concern in view of the widespread presence of fibrates in aquatic environments. Work is needed to test whether exposure to environmental concentrations of these drugs jeopardizes the capacity of fish for reproduction, temperature acclimation or migratory behaviors.


Subject(s)
Gemfibrozil/toxicity , Gene Expression Regulation/drug effects , Hypolipidemic Agents/toxicity , Lipoproteins/drug effects , Water Pollutants, Chemical/toxicity , Animals , Fatty Acids/metabolism , Fatty Acids, Omega-3/metabolism , Female , Lipoprotein Lipase/drug effects , Lipoprotein Lipase/metabolism , Lipoproteins/metabolism , Liver/drug effects , Liver/metabolism , Oncorhynchus mykiss , PPAR alpha/genetics , PPAR gamma/genetics , PPAR-beta/genetics , Sewage/chemistry
19.
BMC Public Health ; 11: 882, 2011 Nov 23.
Article in English | MEDLINE | ID: mdl-22112189

ABSTRACT

BACKGROUND: Pneumonia is still the leading cause of death among children in Africa, and pneumococcal serotypes 1 and 5 are frequently isolated from African children with invasive pneumococcal disease below the age of 5 years. The immunogenicity, safety and reactogenicity of 3-dose primary vaccination with the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) were evaluated in infants in Mali and Nigeria. METHODS: In an open, randomized, controlled study, 357 infants received DTPw-HBV/Hib and OPV primary vaccination with (PHiD-CV group) or without (control group) PHiD-CV co-administration at 6, 10 and 14 weeks of age. Pneumococcal antibody responses and opsonophagocytic activity (OPA) were measured and adverse events (AEs) recorded. RESULTS: One month post-dose 3, ≥ 97.2% of PHiD-CV-vaccinated infants had an antibody concentration ≥ 0.2 µg/mL for each vaccine pneumococcal serotype except for 6B (82.0%) and 23F (87.6%) versus < 10% in the control group except for serotypes 14 (35.7%) and 19F (22.5%). For each vaccine serotype, ≥ 93.3% of PHiD-CV recipients had an OPA titre ≥ 8, except for serotypes 1 (87.6%) and 6B (85.4%), compared to < 10% in the control group, except for serotypes 7F (42.9%), 9V (24.1%) and 14 (24.5%). Anti-protein D geometric mean antibody concentrations were 3791.8 and 85.4 EL.U/mL in the PHiD-CV and control groups, respectively. Overall incidences of solicited and unsolicited AEs were similar between groups. CONCLUSIONS: In sub-Saharan African infants, PHiD-CV was immunogenic for all vaccine pneumococcal serotypes and protein D. Vaccine tolerability was generally comparable between the PHiD-CV and control groups. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00678301.


Subject(s)
Bacterial Proteins/immunology , Carrier Proteins/immunology , Haemophilus Infections/prevention & control , Haemophilus influenzae/immunology , Immunoglobulin D/immunology , Lipoproteins/immunology , Pneumococcal Vaccines/therapeutic use , Primary Prevention , Africa South of the Sahara , Bacterial Proteins/drug effects , Carrier Proteins/drug effects , Female , Haemophilus influenzae/drug effects , Humans , Immunoglobulin D/drug effects , Infant , Lipoproteins/drug effects , Male , Mali , Nigeria , Pneumococcal Vaccines/administration & dosage , Pneumococcal Vaccines/pharmacology
20.
Circ J ; 74(8): 1644-50, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20574136

ABSTRACT

BACKGROUND: Remnant lipoproteinemia is a strong risk factor for cardiovascular (CV) diseases. This study examined which of 2 common lipid-lowering drugs (fibrates and statins) is more effective in patients with remnant lipoproteinemia and if lowering remnant lipoprotein levels can reduce CV risk. METHODS AND RESULTS: Remnant lipoprotein levels were measured by an immunoseparation method (remnant-like lipoprotein particles cholesterol: RLP-C) in 274 patients with coronary artery disease and high RLP-C levels (>or=5.0 mg/dl). They were randomly assigned to receive bezafibrate (200-400 mg/day) or pravastatin (10-20 mg/day), and were prospectively followed-up for 1 year or until the occurrence of CV events. Complete follow-up data were obtained in 180 patients. RLP-C levels at 1 year of treatment were reduced more by bezafibrate than pravastatin (37% and 25% from baseline, respectively). During follow-up, bezafibrate-treated patients had 3 CV events, compared with 12 events in pravastatin-treated patients (P<0.01). In multivariate logistic regression analysis, a decrease in RLP-C level was significantly associated with a reduction in CV events after adjustment for treatment group and changes in levels of other lipids. CONCLUSIONS: Bezafibrate therapy decreased RLP-C levels to a greater extent than pravastatin and a decrease in RLP-C level may be associated with a reduction in CV events in patients with high RLP-C levels.


Subject(s)
Bezafibrate/administration & dosage , Coronary Artery Disease/drug therapy , Lipoproteins/drug effects , Pravastatin/administration & dosage , Aged , Anticholesteremic Agents/therapeutic use , Cardiovascular Diseases/prevention & control , Cholesterol/blood , Female , Follow-Up Studies , Humans , Hypolipidemic Agents/therapeutic use , Lipids/blood , Lipoproteins/blood , Male , Middle Aged , Triglycerides/blood
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