scholarly journals The effects of fat consumption on low-density lipoprotein particle size in healthy individuals: a narrative review

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Erik Froyen
Keyword(s):  
Fatty Acids ◽  
Particle Size ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Healthy Individuals ◽  
Cvd Risk ◽  
Small Dense Ldl ◽  
Ldl Particles ◽  
Fat Consumption

AbstractCardiovascular disease (CVD) is the number one contributor to death in the United States and worldwide. A risk factor for CVD is high serum low-density lipoprotein cholesterol (LDL-C) concentrations; however, LDL particles exist in a variety of sizes that may differentially affect the progression of CVD. The small, dense LDL particles, compared to the large, buoyant LDL subclass, are considered to be more atherogenic. It has been suggested that replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids decreases the risk for CVD. However, certain studies are not in agreement with this recommendation, as saturated fatty acid intake did not increase the risk for CVD, cardiovascular events, and/or mortality. Furthermore, consumption of saturated fat has been demonstrated to increase large, buoyant LDL particles, which may explain, in part, for the differing outcomes regarding fat consumption on CVD risk. Therefore, the objective was to review intervention trials that explored the effects of fat consumption on LDL particle size in healthy individuals. PubMed and Web of Science were utilized during the search process for journal articles. The results of this review provided evidence that fat consumption increases large, buoyant LDL and/or decreases small, dense LDL particles, and therefore, influences CVD risk.

Further insights into the pathophysiology of hyperapobetalipoproteinemia: role of basic proteins I, II, III

1991 ◽  
Vol 37 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Peter O Kwiterovich ◽  
Mahnaz Motevalli ◽  
Michae Miller ◽  
Paul S Bachorik ◽  
Stephanie D Kafonek ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Low Density ◽  
Basic Proteins ◽  
Ldl Particles ◽  
Ester Formation ◽  
Normal Human

Abstract Hyperapobetalipoproteinemia (hyperapoB), a familial lipoprotein disorder characterized by an increase in small, dense, low-density lipoprotein (LDL) particles, is strongly associated with coronary artery disease. There are two metabolic defects in hyperapoB: an increased synthesis of a very-low-density lipoprotein in liver, resulting in an overproduction of LDL, and a delayed clearance of post-prandial triglyceride and free fatty acids. To date, defects in the apolipoprotein B gene do not appear to explain the hyperapoB phenotype. Defect(s) in the uptake or intracellular metabolism of free fatty acids have been found in cells from hyperapoB patients. Three basic proteins (BPs)--BP I (Mr 14,000, pI 9.10), BP II (Mr 27,500, pI 8.48), and BP III (Mr 55,000, pI 8.73)--were isolated from normal human serum. Compared with normal fibroblasts, cultured hyperapoB fibroblasts incubated with BP I, which appears to be the same protein as acylation-stimulating protein (ASP), showed 50% less stimulation of triglyceride acylation and cholesterol esterification, whereas BP II markedly stimulated cholesteryl ester formation, and BP III caused no difference in response vs normal fibroblasts. However, in cultured normal human monocyte macrophages, BP III, but not BP I or BP II, stimulated cholesteryl esterification two- to threefold. BP I, BP II, and BP III may provide new insights into normal metabolism of lipids, lipoproteins, and free fatty acids and the pathophysiology of hyperapoB.

scholarly journals Oxidative Modification of Lipoproteins: A Potential Role of Oxidized Small dense LDL in Enhanced Atherogenicity

2021 ◽  
pp. 118-140
Author(s):  
Mohammed Alsaweed
Keyword(s):  
Arterial Wall ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Predictive Marker ◽  
Oxidative Modification ◽  
Cholesterol Homeostasis ◽  
Low Density ◽  
Small Dense Ldl ◽  
Ldl Particles ◽  
Apoprotein B

Atherosclerosis (AS) is a multifaceted inflammatory syndrome of the arterial wall to which number of mediators have been implicated in lesion progression. Triglyceride (TG)-rich lipoproteins consist of the large diversity of lipoprotein particles that fluctuate in density, size, and apolipoprotein composition. Two foremost phenotypes, on basis of size, chemical configuration, and density, of low-density-lipoprotein (LDL) have been recognized i.e., pattern A, having LDL diameter greater than 25.5nm (large buoyant LDL or lb-LDL) and pattern B, having LDL diameter less than or equal to 25.5nm (small-dense LDL or sd-LDL). Small-dense low-density-lipoprotein (sd-LDL) particles are produced by potential intravascular hydrolysis of TG-rich VLDL particles via lipoprotein lipases (LPLs), hepatic lipases (HLs) and cholesterol ester transfer protein (CETP). sd-LDL is more atherogenic due to its smaller size, increased penetration into the arterial wall, extended plasma half-life, lesser binding affinity for LDL receptors (LDL-R) as well as lower resistance to oxidative stress when equated with lb-LDL. The higher atherogenic potential of sd-LDL is due to its enhanced susceptibility to oxidation, owing to high polyunsaturated fatty acids (PUFA), low cholesterol and Apoprotein B (ApoB) content. An enhanced understanding of sd-LDL metabolism at the molecular level, transport and clearance may result in the development of sd-LDL as an independent predictive marker for AS events and may be used to maintain cholesterol homeostasis and prevent the succession of AS.

scholarly journals The Effects of Linoleic Acid Consumption on Lipid Risk Markers for Cardiovascular Disease

2021 ◽  
Author(s):  
Erik Froyen
Keyword(s):  
Cardiovascular Disease ◽  
Fatty Acids ◽  
Linoleic Acid ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Risk Markers ◽  
Cvd Risk ◽  
Acid Consumption

Cardiovascular disease (CVD) is the number one contributor to death in the United States and worldwide. Lipid risk markers for CVD include high serum concentrations of total cholesterol, low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein cholesterol (VLDL-C), lipoprotein (a), and triglycerides, as well as low serum concentrations of high-density lipoprotein cholesterol (HDL-C). Additional factors to assess CVD risk include apolipoprotein A (associated with HDL) and apolipoprotein B (associated with LDL). A suggested dietary strategy to decrease these risk factors is to replace a portion of saturated fatty acids with unsaturated fatty acids – especially polyunsaturated fatty acids (PUFAs). One PUFA, in particular, is the essential omega-6 PUFA linoleic acid, which has been demonstrated to affect these CVD risk markers. Therefore, this chapter will discuss the effects of linoleic acid consumption on lipid risk markers for CVD in healthy individuals, the associated mechanisms, and dietary recommendations to decrease CVD risk.

Triacylglycerol-rich lipoproteins and the generation of small, dense low-density lipoprotein

2003 ◽  
Vol 31 (5) ◽  
pp. 1066-1069 ◽  
Author(s):  
C.J. Packard
Keyword(s):  
Residence Time ◽  
Hepatic Lipase ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Predisposing Factor ◽  
Small Dense Ldl ◽  
Lipoprotein Class ◽  
Ldl Particles ◽  
Clinical Benefits

LDL (low-density lipoprotein) is the major carrier of cholesterol in human plasma, and as such is intimately involved in the process of atherosclerosis. The lipoprotein class comprises a number of distinct subfractions, and is commonly divided into large, intermediate and small sized particles. Small, dense LDLs are held to be particularly atherogenic, since these particles are retained preferentially by the artery wall, are readily oxidized and carry an enzyme believed to have an important role in atherosclerosis, i.e. lipoprotein-associated phospholipase A2. Generation of small, dense LDL occurs by intravascular lipoprotein remodelling as a result of disturbances such as Type II diabetes, metabolic syndrome, renal disease and pre-eclampsia. The key predisposing factor is the development of hypertriglyceridaemia, in particular elevation in the plasma concentration of large, triacylglycerol-rich VLDL (very-low-density lipoprotein). This leads to the formation of slowly metabolized LDL particles (5-day residence time), which are subject to exchange processes that remove cholesteryl ester from the particle core and replace it with triacylglycerol. LDL, so altered, is a potential substrate for hepatic lipase; if the activity of the enzyme is high enough, lipolysis will generate smaller, denser particles. Correction of the dyslipidaemia associated with small, dense LDL is possible using fibrates and statins, and this may contribute to the clinical benefits seen with these drugs. Fibrates act to lower plasma triacylglycerol (VLDL) levels, and so correct the underlying metabolic disturbance. Statins remove VLDL particles via receptor-mediated pathways and reduce the residence time (and hence limit the potential for remodelling) of LDL in the circulation.

Platelet-activating factor acetylhydrolase and transacetylase activities in human plasma low-density lipoprotein

2001 ◽  
Vol 357 (2) ◽  
pp. 457-464 ◽  
Author(s):  
Demokritos C. TSOUKATOS ◽  
Theodoros A. LIAPIKOS ◽  
Alexandros D. TSELEPIS ◽  
M. John CHAPMAN ◽  
Ewa NINIO
Keyword(s):  
Human Plasma ◽  
Low Density Lipoprotein ◽  
Platelet Activating Factor ◽  
Density Lipoprotein ◽  
Biologically Active ◽  
Low Density ◽  
Ether Linkage ◽  
Small Dense Ldl ◽  
Ldl Particles ◽  
Ldl Subfractions

In this study, we demonstrate the presence of a transacetylase activity in human plasma low-density lipoprotein (LDL) that transfers short-chain fatty acids from platelet-activating factor (PAF) and its close ether- and ester-linked analogues to ether/ester-linked lysophospholipids (lyso-PL). We show evidence that both PAF acetylhydrolase (PAF-AH) and transacetylase activities are inhibited to the same extent by serine esterase inhibitors, are resistant to heat treatment, and exhibit identical distributions in lipoprotein classes and in LDL subfractions. Additionally, the competitive inhibition of PAF-AH by lyso-PL, and the evidence that the recombinant PAF-AH also showed a similar transacetylase activity, suggest that PAF-AH is responsible for both activities. Using PAF as a donor molecule and lyso-PAF (1-O-alkyl-sn-glycero-3-phosphocholine) as an acceptor, the transacetylase activity showed typical allosteric kinetics, due to the positive co-operativity of the substrates, with apparent Vmax = 19.6±3.4nmol/min per mg of protein, apparent h = 2.0±0.3 and apparent [S]0.5 = 9.4±2.3μM at saturation for the concentration of lyso-PAF. The substrate specificity of the donor molecules was decreased by increasing the chain length of the acyl moiety in the sn-2 position of the glycerol. The ether linkage in the sn-1 position of the substrate was 30% more effective than the ester bond; cholesteryl acetate was inactive as an acetyl donor. The two acceptors tested, lyso-PAF and the ester-linked lyso-PC (1-acyl-sn-glycero-3-phosphocholine), showed similar specificity. Addition of exogenous lyso-PAF induced the transient formation of PAF-like aggregating activity predominately in small dense LDL subfractions upon oxidation. We conclude that PAF-AH possesses both transacetylase and acetylhydrolase activities which remove PAF and its ether-linked analogues from LDL particles upon LDL oxidation. However, in atherogenic small dense LDL-5 particles, the transacetylase activity may acetylate extracellular lyso-PAF into biologically active PAF.

Intralysosomal Accumulation of Colloidal Gold-Low Density Lipoprotein Conjugates in Chloroquine-Treated Fibroblasts

1985 ◽  
Vol 43 ◽  
pp. 546-547 ◽  
Author(s):  
Dean A. Handley ◽  
Cynthia M. Arbeeny ◽  
Larry D. Witte
Keyword(s):  
Colloidal Gold ◽  
Cultured Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Coated Vesicle ◽  
Low Density ◽  
Cholesterol Esters ◽  
Cultured Fibroblasts ◽  
Surface Receptors ◽  
Ldl Particles

Low density lipoproteins (LDL) are the major cholesterol carrying particles in the blood. Using cultured cells, it has been shown that LDL particles interact with specific surface receptors and are internalized via a coated pit-coated vesicle pathway for lysosomal catabolism. This (Pathway has been visualized using LDL labeled to ferritin or colloidal gold. It is now recognized that certain lysomotropic agents, such as chloroquine, inhibit lysosomal enzymes that degrade protein and cholesterol esters. By interrupting cholesterol ester hydrolysis, chloroquine treatment results in lysosomal accumulation of cholesterol esters from internalized LDL. Using LDL conjugated to colloidal gold, we have examined the ultrastructural effects of chloroquine on lipoprotein uptake by normal cultured fibroblasts.

PCSK9 Inhibitors: Novel Therapeutic Strategies for Lowering LDLCholesterol

2018 ◽  
Vol 19 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Yan Wang ◽  
Zhao-Peng Liu
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Maximum Tolerated Dose ◽  
Therapeutic Strategies ◽  
Low Density ◽  
Pcsk9 Inhibitors ◽  
Cvd Risk ◽  
Safety Issues ◽  
Novel Therapeutic Strategies ◽  
Novel Therapeutic

Statins are currently the major therapeutic strategies to lower low-density lipoprotein cholesterol (LDL-C) levels. However, a number of hypercholesterolemia patients still have a residual cardiovascular disease (CVD) risk despite taking the maximum-tolerated dose of statins. Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein receptor (LDLR), inducing its degradation in the lysosome and inhibiting LDLR recirculating to the cell membranes. The gain-offunction mutations in PCSK9 elevate the LDL-C levels in plasma. Therefore, PCSK9 inhibitors become novel therapeutic approaches in the treatment of hypercholesterolemia. Several PCSK9 inhibitors have been under investigation, and much progress has been made in clinical trials, especially for monoclonal antibodies (MoAbs). Two MoAbs, evolocumab and alirocumab, are now in clinical use. In this review, we summarize the development of PCSK9 inhibitors, including antisense oligonucleotides (ASOs), small interfering RNA (siRNA), small molecule inhibitor, MoAbs, mimetic peptides and adnectins, and the related safety issues.

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