OBJECTIVE: To analyze and characterize the separation effectiveness of self-constructed asymmetrical flow field-flow fractionation system on proteins and lipoproteins, to achieve the optimization of the experimental conditions when separating lipoproteins by orthogonal design test and to investigate the carrier viscosity's influence on separation effectiveness. METHODS: The evaluation of asymmetrical flow field-flow fractionation separation capacity was conducted by using two standard proteins (carbonic anhydrase and thyroglobulin). Under the optimized separation conditions of carbonic anhydrase and thyroglobulin, the channel actual thickness (after assembling, the actual thickness of separation channel was less than initial thickness) was calculated by the analytes' elution time based on the hydrokinetic theory. With orthogonal design test the optimized experimental conditions were studied and statistical analysis was carried on to find out the factors with statistical significance which needed further exploration. RESULTS: According to the hydrodynamics principle and Stoke's function, the channel actual thickness was measured to be 164 μm by separating the two standard proteins, carbonic anhydrase and thyroglobulin, under proper experimental conditions. By the optimization based on orthogonal design test, base-line separation (the resolution had to be higher than 1.50) was achieved. The resolutions of the two experiments were 1.61 and 1.58. According to previous study/ pre-study and supporting theory, in the orthogonal design test, the total 5 factors were integrated for comprehensive investigation: the total flow rate (3.00, 3.50, 4.00, 4.50 mL/min), focus time (3.00, 3.50, 4.00, 4.50 min), transition time (0.5, 1.0, 1.5, 2.0 min), pH of the carrier fluid(6.8, 7.00, 7.20, 7.40) and viscosity of the carrier fluid hydroxypropylmethylcellulose concentration: 0.00%, 0.03%, 0.06%, 1.00%). Among the 5 factors, viscosity was found to have the statistical significance on separation effectiveness which was further investigated. The resolution of high density lipoprotein and low density lipoprotein was increased by the increasing viscosity which also caused more obvious negative spikes. CONCLUSION The separating capacities of self-constructed asymmetrical flow field-flow fractionation system on lipoproteins were verified to be effective and an optimized experimental condition was found to achieve the base-line separation of high density lipoprotein and low density lipoprotein. Viscosity of the carrier fluid was proved to have the statistical significance on lipoprotein separation.
Fractionation, Field Flow ; Lipoproteins ; Lipoproteins, LDL

No abstract available.
Cholesterol ; Cholesterol, LDL ; Humans ; Lipoproteins

Low-density lipoprotein receptor (LDLR) and metabolic syndrome (MS) are closely correlated. Changes in LDLR expression, feedback regulation and degradation, impacts of LDLR deficiency on blood lipid levels, roles of LDLR in islet β cell dysfunction and cholesterol homeostasis dysregulation, expression of LDLR gene nuclear transcription factors and polymorphism of LDLR gene segments are all involved in the development of specific components of MS. In recent years, a variety of targets and intervention mechanisms in relation to LDLR and MS have been extensively studied. Knowledge about association between LDLR and MS may contribute to the development of strategies for prevention and treatment of MS. This article reviews the update on the association between LDLR and MS.
Homeostasis ; Humans ; Lipid Metabolism ; Lipoproteins, LDL ; Metabolic Syndrome ; Receptors, LDL

OBJECTIVETo investigate effects of serum HDL(1) on the formation of foam cells from human peripheral blood monocyte-derived macrophages.

METHODSSectie density polyacrylamide gel electrophoresis (sd-PAGE) was applied for isolation and preparation of HDL(1) simultaneously. Monocytes were isolated from human peripheral blood by Ficoll-Hypaque density gradient centrifugation and plastic adsorptive process. The isolated monocytes were stimulated by phorbol 12-myristate 13-acetate (PMA) at a concentration of 50 nmol/L for 48 h and transferred to macrophages. The monocyte-derived macrophages were then coincubated with 80 mg/L ox-LDL and HDL(1) (0, 0.1, 1.0 and 10.0 mg/L) for 6, 12 and 24 h, respectively. The formation of foam cells was identified by transmission electron microscope (TEM), total cholesterol (TC), free cholesterol (FC) and protein (Pro) in cultured cells were quantitatively analyzed by high performance chromatography (HPLC) and modified lowry protein assay, respectively.

RESULTSHDL(1) isolated from human serum by sd-PAGE could significantly decrease TC/Pro ratio in foam cells in a concentration-dependent (0 mg/L: 36.9 +/- 1.1, 10.0 mg/L: 6.2 +/- 0.4, P < 0.01) and time-dependent (10.0 mg/L HDL(1) 6 h: 16.9 +/- 0.9, 24 h: 6.4 +/- 0.6, P < 0.01) manner.

CONCLUSIONHDL(1) is capable of inhibiting and attenuating the formation of foam cells by decreasing cellular TC, therefore, might play an important role in attenuating atherosclerosis.

Atherosclerosis ; Cells, Cultured ; Cholesterol, LDL ; metabolism ; Foam Cells ; cytology ; metabolism ; Humans ; Lipoproteins, HDL ; blood ; Lipoproteins, LDL ; Monocytes ; cytology ; metabolism

BACKGROUND: This study investigated the effects of Korean red ginseng (KRG) supplementation on metabolic parameters, inflammatory markers, and arterial stiffness in subjects with metabolic syndrome. METHODS: We performed a randomized, double-blind, placebo-controlled, single-center study in 60 subjects who were not taking drugs that could affect metabolic and vascular functions. Subjects were randomized into either a KRG (4.5 g/d) group or a placebo group for a 12-week study. We collected anthropometric measurements, blood for laboratory testing, and brachial-ankle pulse wave velocity (baPWV) at the initial (week 0) and final (week 12) visits. RESULTS: A total of 48 subjects successfully completed the study protocol. Oral administration of KRG did not significantly affect blood pressure, oxidative or inflammatory markers, or baPWV. CONCLUSION: We found no evidence that KRG had an effect on blood pressure, lipid profile, oxidized low density lipoprotein, fasting blood glucose, or arterial stiffness in subjects with metabolic syndrome. These findings warrant subsequent longer-term prospective clinical investigations with a larger population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00976274
Administration, Oral ; Blood Glucose ; Blood Pressure ; Fasting ; Lipoproteins ; Lipoproteins, LDL ; Panax ; Pulse Wave Analysis ; Vascular Stiffness

Experimental, epidemiological and clinical studies indicate and important relationship between abnormalities in serum lipoproteins and atherosclerosis. With the introduction in 1965 by Fredrickson and Lees of a system for phenotyping hyperlipoproteinemias, quantitation of pre-and beta-lipoproteins gained much significance, and hence, the development of simple method for studying serum lipids and lipoproteins is needed. In the past, several methods have been proposed for the estimation of serum lipoproteins by electrophoresis. Authors observed serum total lipoprotein, beta-lipoprotein, pre-beta-lipoprotein and alpha-lipoprotein fractions in 80 (male:40, female;40)normal individuals with electrophoesis using cellulose acetate membrane instead of filter paper and concluded as follow: 1) Total lipoprotein and beta-lipoprotein levels had increasing tendency according to aging on both sexes. 2) Serum pre-beta-lipoprotein level also had increasing tendency according to age on both sexes and these features are more conspicious after fifth decade. 3) Electrophoresis using cellulose acetate membrance seem to be convinient method for analysis of serum lipoproteins especially pre-beta-lipoprotein fraction. 4) This method can be likely applied as routine screening test of hyperlipemia.
Aging ; Atherosclerosis ; Cellulose* ; Electrophoresis* ; Hyperlipidemias ; Hyperlipoproteinemias ; Lipoproteins ; Lipoproteins, LDL ; Mass Screening ; Membranes*

Lipoprotein lipase (LPL) is known to be attached to the luminal surface of vascular endothelial cells in a complex with membrane-bound heparan sulfate, and released into blood stream by heparin. LPL that catalyzes hydrolysis of triglyceride (TGL) on chylomicron and VLDL into two fatty acids and monoacylglycerol, is also implicated to participate in an enhancement of cholesterol uptake by arterial endothelial cells in vitro. But little is known about the LPL-mediated cholesterol uptake in physiological state. In this study, changes in blood lipid composition and levels of lipoproteins were determined after the injection of heparin in human. The level of LPL in plasma was increased from 0 to 11 mU/ml within 30-40 min post-heparin administration and decreased to the basal level within 2 h. The level of TGL in plasma decreased from 70 mg/dl to 20 mg/dl within 1 h and gradually increased to 80 mg/dl within 4 h. However the level of total cholesterol in plasma remained at 140 mg/dl during an experimental period of 4 h. Analysis of Lipoproteins in plasma by NaBr density gradient ultracentrifugation showed that the level of VLDL decreased from 50 mg/dl to 10 mg/dl within 1-2 h and returned to normal plasm level at 4 h. However there were no significant changes in the level of LDL and HDL. These results suggest that, at least, in normo-lipidemic subjects, increased free plasm LPL acts primarily on VLDL and failed to show any significant uptake of cholesterol-rich lipoproteins in human.
Adult ; Cholesterol/blood ; Heparin/pharmacology* ; Heparin/administration & dosage ; Human ; Immunoblotting ; Lipoprotein Lipase/blood* ; Lipoproteins/blood* ; Lipoproteins, HDL/blood ; Lipoproteins, LDL/blood ; Lipoproteins, VLDL/blood ; Triglycerides/blood

This study was performed to examine the combined effects of gamma linolenic acid and isoflavone supplementation on menopausal symptoms and serum lipids in 73 postmenopausal women. A total subjects were randomly assigned to isoflavone (30 mg) + gamma-linolenic acid (110 mg) group or placebo group. We measured menopausal symptoms by modified Kupperman Index (KI) and oxidized LDL, lipid peroxides, blood components and anthropometric parameters before and after the 12 week intervention period. After the 12 weeks of supplementation, supplement group and placebo group showed a significant reduction of modified kupperman index (p < 0.001). Isoflavone (30 mg) + gamma-linolenic acid (110 mg) supplement group showed a significant reduction of oxidized LDL cholesterol concentration (p = 0.006) whereas placebo group did not show significant change. Isoflavone and gamma-linolenic acid consumption did not significantly affect plasma concentrations of total, LDL, HDL cholesterol, triglyceride, apo A1, B and blood components. The result of present study demonstrated the supplementation of 30 mg isoflavone and 110 mg gamma-linolenic acid per day for 12 weeks may protect LDL cholesterol from oxidative stress.
Apolipoprotein A-I ; Cholesterol, HDL ; Cholesterol, LDL ; Female ; gamma-Linolenic Acid ; Humans ; Lipid Peroxides ; Lipoproteins, LDL ; Oxidative Stress ; Plasma

This study explores the regulatory effect of astragaloside Ⅳ on miR-17-5 p and its downstream proprotein convertase subtillisin/kexin type 9(PCSK9)/very low density lipoprotein receptor(VLDLR) signal pathway, aiming at elucidating the mechanism of astragaloside Ⅳ against atherosclerosis(AS). In cell experiment, oxidized low-density lipoprotein(ox-LDL) was used for endothelial cell injury modeling with vascular smooth muscle cells(VSMCs). Then cells were classified into the model group, miR-17-5 p inhibitor group, blank serum group, and astragaloside Ⅳ-containing serum group based on the invention. Afterward, cell viability and the expression of miR-17-5 p, VLDLR, and PCSK9 mRNA and protein in cells in each group were detected. In animal experiment, 15 C57 BL/6 mice were used as the control group, and 45 ApoE~(-/-) mice were classified into the model group, miR-17-5 p inhibitor group, and astragaloside Ⅳ group, with 15 mice in each group. After 8 weeks of intervention, the peripheral serum levels of interleukin-6(IL-6), interleukin-10(IL-10), and tumor necrosis factor-α(TNF-α), and the expression of miR-17-5 p, VLDLR, and PCSK9 mRNA in the aorta of mice were detected. The pathological changes of mice in each group were observed. According to the cell experiment, VSMC viability in the miR-17-5 p inhibitor group and the astragaloside Ⅳ-containing serum group was higher than that in the model group(P<0.05). The mRNA and protein expression of miR-17-5 p and VLDLR in VSMCs in the miR-17-5 p inhibitor group and the astragaloside Ⅳ-containing serum group was lower than that in the model group(P<0.05), but the mRNA and protein expression of PCSK9 was higher than that in the model group(P<0.05). As for the animal experiment, the levels of IL-6 and TNF-α in the peripheral serum of the miR-17-5 p inhibitor group and the astragaloside Ⅳ group were lower(P<0.05) and the serum level of IL-10 was higher(P<0.05) than that of the model group. The mRNA expression of miR-17-5 p and VLDLR in the aorta in the miR-17-5 p inhibitor group and the astragaloside Ⅳ group was lower(P<0.05), and PCSK9 mRNA expression was higher(P<0.05) than that in the model group. Pathological observation showed mild AS in the miR-17-5 p inhibitor group and the astragaloside Ⅳ group. In summary, astragaloside Ⅳ can prevent the occurrence and development of AS. The mechanism is that it performs targeted regulation of miR-17-5 p, further affecting the PCSK9/VLDLR signal pathway, inhibiting vascular inflammation, and thus alleviating endothelial cell injury.
Animals ; Atherosclerosis/genetics* ; Lipoproteins, LDL/metabolism* ; Mice ; MicroRNAs/metabolism* ; Proprotein Convertase 9/metabolism* ; Receptors, LDL/metabolism* ; Saponins ; Signal Transduction ; Triterpenes

To observe the effect of oxidized low density lipoprotein (OxLDL) on arterial endothelial cells apoptosis in vivo, we established a model in which Sprague-Dawley rats were given intraperitoneal and intravenous injection of unmodified LDL (8 mg/kg every day) via the tail vein. Seven days after the injection, the aortic endothelial cells specimens were prepared by an en face preparation of rat aorta. The apoptotic cells were identified and counted by in situ nick and labelling (TUNEL) method and light microscopy. The numbers of the apoptotic cells were 12.52 +/- 4.71/field in the intraperitoneal injection control group, 11.41 +/- 2.94/field in the intravenous injection control group, 22.98 +/- 8.01/field in the intraperitoneal injection LDL group and 103.8 +/- 11.5/field in the intravenous injection LDL group, respectively. The difference was significant between injection LDL group and control (P < 0.01), and the difference was also significant between two LDL injection groups (P < 0.01). These findings suggest that injection of LDL can induce apoptosis in arterial endothelial cells and the effect is especially significant with intravenous injection LDL. After injection, oxidative modification of LDL may occur in local arteries and causes injury to the endothelial cells.
Aorta ; Apoptosis/*drug effects ; Endothelium, Vascular/*pathology ; In Situ Nick-End Labeling ; Injections, Intraperitoneal ; Injections, Intravenous ; Lipoproteins, LDL/*metabolism ; Lipoproteins, LDL/*pharmacology ; Oxidation-Reduction ; Random Allocation ; Rats, Sprague-Dawley