Stent composition and immune response after long-term coronary angioplasty.

Background: There are limited data about the influence of stent composition on immune responses after percutaneous coronary intervention (PCI). Objective: The aim was to compare the effects of PCI with conventional cobalt-chromium bare metal stent (BMS) and drug-eluting stent (DES) implantation on the modulation of humoral and cellular immune responses. Methods: A randomised, single-centre, open pilot study involving patients with stable coronary artery disease eligible for PCI was performed. Blood samples were collected from the peripheral artery (PA) and the coronary sinus (CS) at baseline and 40 weeks following PCI. IgM and IgG autoantibodies (Abs), anti-oxLDL and anti-ApoB-D, as well as cytokine levels were evaluated by enzyme-linked immunosorbent assay. Results: A total of 30 patients of 60 years mean age were included, 68% of whom were men. At the nine-month follow-up, a modulation in the levels of cytokines and autoantibodies was observed in both stent type groups. However, no difference was observed in the modulation of these markers between stents. Conclusion: The stent type promotes modulations in cellular and humoral immune responses in the long-term, with differences in the magnitude of effects in specific immune responses.

Macadamia nut effects on cardiometabolic risk factors: a randomised trial.

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (-4⋅3 mg/dl; 95 % CI -14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (-4⋅7 mg/dl; 95 % CI -14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts. Clinical Trial Registry Number and Website: NCT03801837 https://clinicaltrials.gov/ct2/show/NCT03801837?term = macadamia + nut&draw = 2&rank = 1.

Oxidised Low-Density Lipoprotein-Induced Platelet Hyperactivity-Receptors and Signalling Mechanisms.

Dyslipidaemia leads to proatherogenic oxidative lipid stress that promotes vascular inflammation and thrombosis, the pathologies that underpin myocardial infarction, stroke, and deep vein thrombosis. These prothrombotic states are driven, at least in part, by platelet hyperactivity, and they are concurrent with the appearancxe of oxidatively modified low-density lipoproteins (LDL) in the circulation. Modified LDL are heterogenous in nature but, in a general sense, constitute a prototype circulating transporter for a plethora of oxidised lipid epitopes that act as danger-associated molecular patterns. It is well-established that oxidatively modified LDL promote platelet activation and arterial thrombosis through a number of constitutively expressed scavenger receptors, which transduce atherogenic lipid stress to a complex array of proactivatory signalling pathways in the platelets. Stimulation of these signalling events underlie the ability of modified LDL to induce platelet activation and blunt platelet inhibitory pathways, as well as promote platelet-mediated coagulation. Accumulating evidence from patients at risk of arterial thrombosis and experimental animal models of disease suggest that oxidised LDL represents a tangible link between the dyslipidaemic environment and increased platelet activation. The aim of this review is to summarise recent advances in our understanding of the pro-thrombotic signalling events induced in platelets by modified LDL ligation, describe the contribution of individual platelet scavenger receptors, and highlight potential future challenges of targeting these pathways.

The Placebo-Controlled Effect of Percutaneous Coronary Intervention on Exercise Induced Changes in Anti-Malondialdehyde-LDL Antibody Levels in Stable Coronary Artery Disease: A Substudy of the ORBITA Trial.

Aim: Malondialdehyde-modified low-density lipoprotein (MDA-LDL) forms a significant component of oxidised LDL. The effects of exercise on levels of MDA-LDL and anti-MDA-LDL antibodies are not well-understood. Furthermore, it is not known whether these can be modified in patients with coronary artery disease by percutaneous coronary intervention (PCI). Methods: The Objective Randomised Blinded Investigation with optimal medical Therapy of Angioplasty in stable angina (ORBITA) trial was the first blinded, multi-centre randomised trial of PCI vs. placebo procedure for angina relief. Serum samples were available at four time-points: pre-randomisation pre- (P1) and post- (P2) exercise and post-randomisation (6-weeks following the PCI or placebo procedure), pre- (P3) and post- (P4) exercise. ELISAs were performed using laboratory-developed assays for MDA-LDL (adjusted for Apolipoprotein B) and anti-MDA-LDL antibodies. Results: One hundred ninety-six of the 200 patients (age 66.1 [SD 8.99] years, 28% female) with severe single vessel coronary artery disease suitable for PCI enrolled in the ORBITA trial had blood available for analysis. With exercise at pre-randomisation (P2-P1) there was no significant change in adjusted MDA-LDL (-0.001, 95% CI -0.004 to 0.001; p = 0.287); however, IgG and IgM anti-MDA-LDL significantly declined (-0.022, 95% CI -0.029 to -0.014, p < 0.0001; -0.016, 95% CI -0.024 to -0.008, p = 0.0002, respectively). PCI did not have a significant impact on either the pre-exercise values (P3 controlling for P1) of MDA-LDL (p = 0.102), IgG (p = 0.444) or IgM anti-MDA-LDL (p = 0.909). Nor did PCI impact the exercise induced changes in these markers (P4 controlling for P1, P2, and P3) for MDA-LDL (p = 0.605), IgG (p = 0.725) or IgM anti-MDA-LDL (p = 0.171). Pre-randomisation ischaemia on stress echo did not impact these interactions. Conclusions: Exercise results in an acute reduction in anti-oxLDL antibodies in patients with severe single vessel coronary disease, possibly indicating an induction in homoeostatic clearance via the innate immune system. However, PCI did not ameliorate this effect.

Effect of bariatric surgery on plasma levels of oxidised phospholipids, biomarkers of oxidised LDL and lipoprotein(a).

BACKGROUND: Obesity is associated with adverse cardiovascular outcomes and this is improved following bariatric surgery. Oxidised phospholipids (OxPL) are thought to reflect the pro-inflammatory effects of lipoprotein(a) [Lp(a)], and both are independent predictors of cardiovascular disease. OBJECTIVE: Our study sought to determine the impact of bariatric surgery on OxPL, biomarkers of oxidised LDL (OxLDL) and Lp(a). METHODS: This is a prospective, observational study of 59 patients with severe obesity undergoing bariatric surgery. Blood samples were obtained prior to surgery and at 6 and 12 months after. Sixteen patients attending the tertiary medical weight management clinic at the same centre were also recruited for comparison. Lipid and metabolic blood parameters, OxLDL, OxPL on apolipoprotein B-100 (OxPL-apoB), IgG and IgM autoantibodies to MDA-LDL, IgG and IgM apoB-immune complexes and Lp(a) were measured. RESULTS: Reduction in body mass index (BMI) was significant following bariatric surgery, from median 48 kg/m2 at baseline to 37 kg/m2 at 6 months and 33 kg/m2 at 12 months. OxPL-apoB levels decreased significantly at 12 months following surgery [5.0 (3.2-7.4) to 3.8 (3.0-5.5) nM, p = 0.001], while contrastingly, Lp(a) increased significantly [10.2 (3.8-31.9) to 16.9 (4.9-38.6) mg/dl, p = 0.002]. There were significant post-surgical decreases in IgG and IgM biomarkers, particularly at 12 months, while OxLDL remained unchanged. CONCLUSIONS: Bariatric surgery results in a significant increase in Lp(a) but reductions in OxPL-apoB and other biomarkers of oxidised lipoproteins, suggesting increased synthetic capacity and reduced oxidative stress. These biomarkers might be clinically useful to monitor physiological effects of weight loss interventions.

Oxidised LDL and Anti-Oxidised LDL Antibodies Are Reduced by Lipoprotein Apheresis in a Randomised Controlled Trial on Patients with Refractory Angina and Elevated Lipoprotein(a).

Aims: An abundance of epidemiological evidence demonstrates that elevated lipoprotein(a) (Lp(a)) represents a significant contributing risk factor towards the development of cardiovascular disease. In particular, raised Lp(a) may play a mechanistic role in patients with refractory angina. Studies have also shown a correlation between oxidised LDL (oxLDL) levels and atherosclerotic burden as well as rates of cardiovascular events. Antibodies against oxLDL (anti-oxLDL) are involved in the removal of oxLDL. Lipoprotein apheresis (LA), which removes lipoproteins using extra-corporeal processes, is an established means of reducing Lp(a), and thereby reduces cardiovascular events. The aim of this study was to investigate the effect of LA on oxLDL and anti-oxLDL levels amongst those with refractory angina in the context of raised Lp(a). Methods: We performed a sub-study within a randomised controlled crossover trial involving 20 patients with refractory angina and raised Lp(a) > 500 mg/L, comparing the effect of three months of blinded weekly LA or sham, followed by crossover to the opposite study arm. We utilized enzyme-linked immunosorbent assays (ELISA) to quantify oxLDL and IgG/ IgM anti-oxLDL antibody levels at baseline and following three months of active LA or sham sessions. Results: Following three months of LA, there was a 30% reduction in oxLDL from 0.37 ± 0.06 to 0.26 ± 0.04 with a mean drop of -0.11 units (U) (95% CI -0.13, -0.09) compared to no significant change with sham therapy (p < 0.0001 between treatment arms). LA also led to a 22% reduction in levels of IgG and IgM anti-oxLDL, again with no significant change demonstrated during sham (p = 0.0036 and p = 0.012, respectively, between treatment arms). Conclusion: Amongst patients with refractory angina in the context of elevated Lp(a), LA significantly lowers levels of oxLDL and anti-oxLDL antibodies, representing potential mechanisms by which LA yields symptomatic and prognostic benefits in this patient cohort.

NET-associated citrullinated histones promote LDL aggregation and foam cell formation in vitro.

Neutrophils have been recently identified in the atherosclerotic lesion and they can release neutrophil extracellular trap (NET) under the pro-inflammatory conditions prevailing in the lesion. Citrullinated histones (Cit-histones) are the major type of citrullinated proteins associated with NET release. Since elevated levels of citrullinated proteins have been detected in inflammatory diseases including atherosclerosis, this study analysed the role played by NET and Cit-histones in different atherogenic events in vitro. First, neutrophil recruitment and NET release in the presence of low-density lipoprotein (LDL) and oxidised LDL (Ox-LDL) were analysed by Boyden's chamber method and microscopy respectively. Then, LDL oxidation and LDL aggregation in the presence of NET and Cit-histones were analysed spectroscopically. Foam cell formation in the presence of NET or Cit-histone was studied by both microscopic and spectroscopic methods. While neutrophil recruitment was facilitated by Ox-LDL and not by LDL, the extent of NET release was significantly increased in the presence of both LDL and Ox-LDL. In the presence of NET, LDL oxidation, aggregation and foam cell formation were found to be increased. Cit-histones were found to accelerate LDL aggregation and foam cell formation at higher citrulline levels. Altogether, the results suggest that both NET and NET-associated Cit-histone released at the lesion can play major roles as pro-atherogenic mediators. Inhibiting the action of NET or Cit-histone would, therefore, be beneficial in slowing down atherosclerotic progression.

Recombinant Domain V of beta (2)-Glycoprotein I Inhibits OxLDL-induced TF Expression in Macrophages.

OBJECTIVE: To investigate if lectin-like oxidised low density lipoprotein receptor is implicated in oxidised low density lipoprotein induced up regulation of tissue factor and whether recombinant domain V of beta (2)-Glycoprotein I expressed in Pichia pastoris inhibits the binding of oxidised and lectin-like low density lipoprotein. METHODS: The expression of tissue factor and lectin-like oxidised low density lipoprotein receptor was detected using Western blot methods. Small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor was used to block lectin-like oxidised low density lipoprotein receptor expression. Flow cytometry was used to test the effect of beta (2)-Glycoprotein I expressed in Pichia pastoris on the binding of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor by using the lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. RESULTS: Oxidised low density lipoprotein at 5-10 g/mL increased tissue factor and lectin-like oxidised low density lipoprotein receptor expression, whereas 20-50 g/mL oxidised low density lipoprotein attenuated tissue factor expression. Inhibiting lectin-like oxidised low density lipoprotein receptor expression by small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor impaired oxidised low density lipoprotein-induced tissue factor over expression in macrophages. Pretreatment with beta (2)-Glycoprotein I expressed in Pichia pastoris led to a strong inhibition of tissue factor and lectin-like oxidised low density lipoprotein receptor expression in a dose-dependent manner in macrophages. Flow cytometry analysis showed that beta (2)-Glycoprotein I expressed in Pichia pastoris attenuated the interaction of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor in lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. CONCLUSIONS: Lectin-like oxidised low density lipoprotein receptor was implicated in the expression of tissue factor induced by oxidised low density lipoprotein, and beta (2)-Glycoprotein I expressed in Pichia pastoris inhibited oxidised low density lipoprotein-induced tissue factor and lectin-like oxidised low density lipoprotein receptor expression, at least in part, via inhibition of the interaction between oxidised low density lipoprotein and lectin-like oxidised low density lipoprotein receptor.

Curcumin-galactomannoside complex inhibits pathogenesis in Ox-LDL-challenged human peripheral blood mononuclear cells.

Oxidised low-density lipoprotein (ox-LDL) is a pro-atherogenic molecule, which induces inflammatory response and contributes to the pathogenesis of vascular dysfunction to atherosclerosis. The aim of the present study was to explore the anti-inflammatory effect of a novel bioavailable formulation of curcumin as 'curcumagalactomannosides' (CGM) against ox-LDL-induced inflammatory responses in human peripheral blood mononuclear cells (hPBMCs). Curcumagalactomannosides was made from natural curcumin using the soluble dietary fibre (galactomannans) derived from fenugreek seeds (Trigonella foenumgracum) and the hPBMCs were isolated from healthy human volunteers. The cells were cultured in collagen-coated plates at 37 °C and grouped as Group I (Control), Group II (ox-LDL treated) and Group III (ox-LDL + CGM treated). Further analysis of inflammatory markers, reactive oxygen species and mRNA expression levels indicated significantly increased expressions of iNOS, TNF-α, IL-6 and VCAM-1 in ox-LDL-treated group along with the nuclear translocation of NF-κB. Other inflammatory markers such as LOX, PGE2, total COX and lipid peroxidation level were also found to be significantly (p < 0.05) increased upon ox-LDL treatment. The treatment with CGM on the other hand was found to down-regulate and reverse the ox-LDL-induced alterations indicating its potential anti-inflammatory effect on hPBMCs via. NF-κB signalling pathway.

Vitamin D deficiency, oxidative stress and antioxidant status: only weak association seen in the absence of advanced age, obesity or pre-existing disease.

Vitamin D deficiency (plasma 25-hydroxycholecalciferol (25(OH)D)70 % of participants were vitamin D deficient. No significant correlations and no biomarker differences across 25(OH)D quartiles or groups were seen except for total antioxidant status. A weak direct association (r 0·252, P<0·05) was observed between 25(OH)D and FRAP, and those in the lowest 25(OH)D quartile and group had significantly lower FRAP values. Results did not reveal a clear link between vitamin D status and oxidative stress biomarkers in the absence of advanced age, obesity and disease, though some evidence of depleted antioxidant status in those with vitamin D deficiency was seen. Poor antioxidant status may pre-date increased oxidative stress. Study of effects of correction of deficiency on antioxidant status and oxidative stress in vitamin D-deficient but otherwise healthy subjects is needed.

Consumption of seafood and its estimated heavy metals are associated with lipid profile and oxidative lipid damage on healthy adults from a Spanish Mediterranean area: A cross-sectional study.

The association between the consumption of seafood and its benefits on cardiovascular (CVD) risk can be challenged by its heavy metal (HM) content. This study aimed to explore the association of seafood consumption and its estimated HM contents with the lipid profile and lipid oxidation biomarkers in adults from a Spanish Mediterranean area who do not present risk factors for CVD. In this cross-sectional study, the clinical history, three-day dietary record, lipid profile (LDLc, HDLc, APOB/A, and triglyceride levels), plasma oxidised LDL (oxLDL) and 8-isoprostane levels of 81 adults without risk factors for CVD [43% men, with a mean age of 43.6 years (95%CI: 40.1-47.1)] were assessed. The HM [arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb)] contents of seafood were estimated according to data from analyses of marine species in the same Mediterranean area. Moderate adherence to the Mediterranean diet (score: 4.6 of 9) with a mean seafood consumption of 74.9g/day (95%CI: 59.9-89.9), including 22.7g of shellfish per day (95%CI: 13.5-31.9), was observed. The estimated HM contents were lower than the provisional tolerable weekly intakes (PTWIs): 21.12µg/kg/week As, 0.57µg/kg/week InAs, 0.15µg/kg/week Cd, 1.11µg/kg/week Hg and 0.28µg/kg/week Pb. After adjusting by confounder variables, an increase in shellfish consumption was associated with increases in the levels of LDLc (P=0.013), non-HDLc (P=0.015), APOB/A (P=0.02) and plasma oxLDL (P=0.002). Moreover, an increase in the estimated As and Hg levels in shellfish was associated with an increase in LDLc (P=0.015 and P=0.018, respectively), non-HDLc (P<0.008 and P<0.008, respectively), APOB/A ratio (P=0.008 and P=0.009, respectively), and oxLDL (P≤0.001 and P≤0.001, respectively) levels. In conclusion, in adults without risk factors for CVD, increasing shellfish consumption, even by a moderate amount, could favour a pro-atherogenic lipid profile and a higher level of oxidised LDL. These associations are likely influenced by the estimated exposure to As and Hg from shellfish despite these values are lower than the PTWIs.

Extravascular modified lipoproteins: a role in the propagation of diabetic retinopathy in a mouse model of type 1 diabetes.

AIMS/HYPOTHESIS: We aimed to determine whether plasma lipoproteins, after leakage into the retina and modification by glycation and oxidation, contribute to the development of diabetic retinopathy in a mouse model of type 1 diabetes. METHODS: To simulate permeation of plasma lipoproteins into retinal tissues, streptozotocin-induced mouse models of diabetes and non-diabetic mice were challenged with intravitreal injection of human 'highly-oxidised glycated' low-density lipoprotein (HOG-LDL), native- (N-) LDL, or the vehicle PBS. Retinal histology, electroretinography (ERG) and biochemical markers were assessed over the subsequent 14 days. RESULTS: Intravitreal administration of N-LDL and PBS had no effect on retinal structure or function in either diabetic or non-diabetic animals. In non-diabetic mice, HOG-LDL elicited a transient inflammatory response without altering retinal function, but in diabetic mice it caused severe, progressive retinal injury, with abnormal morphology, ERG changes, vascular leakage, vascular endothelial growth factor overexpression, gliosis, endoplasmic reticulum stress, and propensity to apoptosis. CONCLUSIONS/INTERPRETATION: Diabetes confers susceptibility to retinal injury imposed by intravitreal injection of modified LDL. The data add to the existing evidence that extravasated, modified plasma lipoproteins contribute to the propagation of diabetic retinopathy. Intravitreal delivery of HOG-LDL simulates a stress known to be present, in addition to hyperglycaemia, in human diabetic retinopathy once blood-retinal barriers are compromised.

Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial.

The polyphenol quercetin may prevent CVD due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored. Subjects (n 70) were randomised to receive 162 mg/d quercetin from onion skin extract powder or placebo in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 6-week washout period. Before and after the intervention, ambulatory blood pressure (ABP) and office BP were measured; urine and blood samples were collected; and endothelial function was measured by EndoPAT technology. In the total group, quercetin did not significantly affect 24 h ABP parameters and office BP. In the subgroup of hypertensives, quercetin decreased 24 h systolic BP by -3·6 mmHg (P=0·022) when compared with placebo (mean treatment difference, -3·9 mmHg; P=0·049). In addition, quercetin significantly decreased day-time and night-time systolic BP in hypertensives, but without a significant effect in inter-group comparison. In the total group and also in the subgroup of hypertensives, vasoactive biomarkers including endothelin-1, soluble endothelial-derived adhesion molecules, asymmetric dimethylarginine, angiotensin-converting enzyme activity, endothelial function, parameters of oxidation, inflammation, lipid and glucose metabolism were not affected by quercetin. In conclusion, supplementation with 162 mg/d quercetin from onion skin extract lowers ABP in patients with hypertension, suggesting a cardioprotective effect of quercetin. The mechanisms responsible for the BP-lowering effect remain unclear.

Dietary cholesterol and oxidised cholesterol: effects on sperm characteristics, antioxidant status and hormonal profile in rats.

Present study was designed to compare the potential effects of high serum levels of LDL and oxidised LDL (OxLDL) on spermatogenesis parameters in male Wistar rats. Animals were allocated into three groups and were fed for 14 weeks with normal, cholesterol-rich and oxidised cholesterol-rich diets. Blood lipid profile, sex hormones level, as well as sex organs weight were evaluated. The sex organs weight in oxidised cholesterol-fed group was significantly reduced (P < 0.05). Spermatozoa count in the group with high serum concentration of OxLDL (64 ± 4.2 × 10(6) ) was markedly lower (P < 0.01) than that of normal rats (87 ± 4.1 × 10(6) ) and rats with high serum level of LDL (90 ± 6.3 × 10(6) ). Similarly, the percentage of viable spermatozoa was significantly (P < 0.001) decreased from 78% to 52% by high level of OxLDL in serum. While, nonoxidised LDL did not have suppressive effects on spermatogenesis and organs weight. Consistent with these effects, the serum concentration of sex hormones including FSH (P < 0.001), LH (P < 0.001) and testosterone (P < 0.01) was significantly decreased only in rats with high level of OxLDL but not in rats with high level of nonoxidised LDL. In conclusion, high OxLDL level showed higher destructive effect on reproductive system compared to the high LDL level.

Curcuma oil attenuates accelerated atherosclerosis and macrophage foam-cell formation by modulating genes involved in plaque stability, lipid homeostasis and inflammation.

In the present study, the anti-atherosclerotic effect and the underlying mechanism of curcuma oil (C. oil), a lipophilic fraction from turmeric (Curcuma longa L.), was evaluated in a hamster model of accelerated atherosclerosis and in THP-1 macrophages. Male golden Syrian hamsters were subjected to partial carotid ligation (PCL) or FeCl3-induced arterial oxidative injury (Ox-injury) after 1 week of treatment with a high-cholesterol (HC) diet or HC diet plus C. oil (100 and 300 mg/kg, orally). Hamsters fed with the HC diet were analysed at 1, 3 and 5 weeks following carotid injury. The HC diet plus C. oil-fed group was analysed at 5 weeks. In hyperlipidaemic hamsters with PCL or Ox-injury, C. oil (300 mg/kg) reduced elevated plasma and aortic lipid levels, arterial macrophage accumulation, and stenosis when compared with those subjected to arterial injury alone. Similarly, elevated mRNA transcripts of matrix metalloproteinase-2 (MMP-2), MMP-9, cluster of differentiation 45 (CD45), TNF-α, interferon-γ (IFN-γ), IL-1ß and IL-6 were reduced in atherosclerotic arteries, while those of transforming growth factor-ß (TGF-ß) and IL-10 were increased after the C. oil treatment (300 mg/kg). The treatment with C. oil prevented HC diet- and oxidised LDL (OxLDL)-induced lipid accumulation, decreased the mRNA expression of CD68 and CD36, and increased the mRNA expression of PPARα, LXRα, ABCA1 and ABCG1 in both hyperlipidaemic hamster-derived peritoneal and THP-1 macrophages. The administration of C. oil suppressed the mRNA expression of TNF-α, IL-1ß, IL-6 and IFN-γ and increased the expression of TGF-ß in peritoneal macrophages. In THP-1 macrophages, C. oil supplementation prevented OxLDL-induced production of TNF-α and IL-1ß and increased the levels of TGF-ß. The present study shows that C. oil attenuates arterial injury-induced accelerated atherosclerosis, inflammation and macrophage foam-cell formation.

oxLDL induces injury and defenestration of human liver sinusoidal endothelial cells via LOX1.

Non-alcoholic fatty liver disease is associated with hepatic microangiopathy and liver inflammation caused by type 2 diabetes mellitus. Oxidised LDL (oxLDL) is involved in proinflammatory and cytotoxic events in various microcirculatory systems. The lectin-like oxLDL receptor 1 (LOX1) plays a crucial role in oxLDL-induced pathological transformation. However, the underlying mechanism of oxLDL's effects on liver microcirculation disturbances remains unclear. In this study, we investigated the effects of oxLDL on LOX1 (OLR1) expression and function, as well as on the fenestration features of human liver sinusoidal endothelial cells (HLSECs) in vitro. Primary HLSECs were obtained and cultured. The cells were treated with various concentrations of oxLDL (25, 50, 100 and 200  µg/ml), and the cytotoxicity and expression of LOX1 were examined. Furthermore, LOX1 knockdown was performed using siRNA technology, and the changes in intracellular reactive oxygen species (ROS), NFκB, p65, (p65), endothelin 1 (ET1 (EDN1)), eNOS (NOS3) and caveolin 1 (CAV1) levels were measured. Cells were treated with 100  µg/ml oxLDL, and the fenestra morphology was visualised using scanning electron microscopy. oxLDL significantly increased LOX1 expression at both the mRNA and protein levels in HLSECs in a dose- and time-dependent manner. oxLDL stimulation increased ROS generation and NFκB activation, upregulated ET1 and caveolin 1 expression, downregulated eNOS expression and reduced the fenestra diameter and porosity. All of these oxLDL-mediated effects were inhibited after LOX1 knockdown. These results reveal a mechanism by which oxLDL stimulates the production of LOX1 through the ROS/NFκB signalling pathway and by which LOX1 mediates oxLDL-induced endothelial injury and the defenestration of HLSECs.

Bariatric surgery in morbidly obese patients improves the atherogenic qualitative properties of the plasma lipoproteins.

OBJECTIVE: The purpose of this study was to evaluate the effect of weight loss induced in morbidly obese subjects by Roux-en-Y gastric bypass bariatric surgery on the atherogenic features of their plasma lipoproteins. METHODS: Twenty-one morbidly obese subjects undergoing bariatric surgery were followed up for up to 1 year after surgery. Plasma and lipoproteins were assayed for chemical composition and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity. Lipoprotein size was assessed by non-denaturing polyacrylamide gradient gel electrophoresis, and oxidised LDL by ELISA. Liver samples were assayed for mRNA abundance of oxidative markers. RESULTS: Lipid profile analysis revealed a reduction in the plasma concentrations of cholesterol and triglycerides, which were mainly associated with a significant reduction in the plasma concentration of circulating apoB-containing lipoproteins rather than with changes in their relative chemical composition. All patients displayed a pattern A phenotype of LDL subfractions and a relative increase in the antiatherogenic plasma HDL-2 subfraction (>2-fold; P < 0.001). The switch towards predominantly larger HDL particles was due to an increase in their relative cholesteryl ester content. Excess weight loss also led to a significant decrease in the plasma concentration of oxidised LDL (∼-25%; P < 0.01) and in the total Lp-PLA2 activity. Interestingly, the decrease in plasma Lp-PLA2 was mainly attributed to a decrease in the apoB-containing lipoprotein-bound Lp-PLA2. CONCLUSION: Our data indicate that the weight loss induced by bariatric surgery ameliorates the atherogenicity of plasma lipoproteins by reducing the apoB-containing Lp-PLA2 activity and oxidised LDL, as well as increasing the HDL-2 subfraction.

Differential partitioning of antioxidants, including hydroxytyrosol, in human plasma and LDL: implications for their antioxidant activity in vivo.

In vivo studies of LDL oxidation following consumption of natural phenolic compounds have yielded mixed results. It is reported that the amphiphilic hydroxytyrosol, after addition to human plasma, does not accumulate in LDL but protects plasma lipids, which are extracted together with hydroxytyrosol, from chemically-induced oxidation. Thus, a novel methodology was proposed, which does not rely on LDL separation and subsequent oxidation but is based on the oxidation of total lipids - simultaneously extracted from plasma with antioxidants - to evaluate the effects of micronutrients that do not partition into LDL, after in vivo supplementation.

Heterogeneidade e mecanismos moleculares da atividade anti-apoptótica das subfrações de HDL em células endoteliais humanas / Heterogeneity and molecular mechanisms of anti-apoptotic activity of high-density lipoprotein (HDL) subfractions on endothelial cells

Introdução: A lipoproteína de baixa densidade (LDL) e suas formas oxidadas (LDLox) possuem múltiplas propriedades aterogênicas, atuando na deposição de colesterol, indução e manutenção da inflamação, disfunção endotelial, surgimento de células espumosas na parede arterial e conseqüente formação da placa de ateroma. Adicionalmente, LDLox induz apoptose de células endoteliais humanas (HMEC). A lipoproteína de alta densidade (HDL) possui inúmeras atividades antiaterogênicas, incluindo ações antioxidante, anti-inflamatória e anti-trombótica. A HDL é capaz de proteger as HMEC contra apoptose. As subfrações de HDL (sHDL) são heterogêneas em sua composição físico-química e atividades biológicas. A atividade antioxidante das sHDL aumenta com a densidade (HDL2b100% - anexina V) e 3b (43% e 67%, respectivamente) de indivíduos normolipidêmicos apresentaram atividade anti-apoptótica mais potente do que as subfrações HDL2a (29% e 28%; p<0,01 vs. HDL3c, respectivamente) e 2b (25% e 62%; p<0,001 vs. HDL3c, respectivamente). Todas sHDL reduziram geração de espécies reativas de oxigênio (ROS) induzida pela LDLox, sendo a HDL3c (54%) mais potente do que HDL2b (21%; p<0.05 vs. HDL3c). Houve correlação positiva entre as atividades anti-apoptótica e antioxidante intracelular com conteúdo de apoA-I e esfingosina 1-fosfato (E1F) das sHDL, senda HDL3b e 3c ricas em E1F. A atividade anti-apoptótica da E1F e das sHDL parece depender da interação com as células endoteliais via apoA-I e seu receptor SR-BI. Finalmente, as HDL3c (n=5) isoladas de pacientes com SMet possuem conteúdo significativamente menor de apoA-I e reduzida atividade anti-apoptótica (60%, p<0,01), quando comparada aos controles normolipidêmicos (n=5). Houve tendência à diminuição da proteção contra a geração de ROS (SMet, n=10). Conclusão: As subfrações HDL3c protegem de forma potente as células endoteliais humanas contra toxicidade e apoptose induzidas pela LDLox, assim como contra geração de ROS...

Background: Low density lipoprotein (LDL) and its oxidized forms (oxLDL) have several atherogenic properties, including cholesterol deposition, inflammation, endothelial dysfunction and foam cell formation on the arterial wall, leading to atherosclerotic plaque development. In addition, oxLDL induces human endothelial cell apoptosis (HMEC). High-density lipoprotein (HDL) has number of antiatherogenic activities, as antioxidative, anti-inflammatory and anti-thrombotic actions. HDL displays anti-apoptotic activity and is able to protect endothelial cells against oxLDL-induced apoptosis. HDL subfractions (sHDL) are highly heterogeneous in their physical and chemical composition and biological functions. Antioxidative activity of HDL subfractions increases with increment in density, HDL2b100% in annexin V biding) and 3b subfractions (43% and 67%, respectively) were more potent against oxLDL-induced toxicity and apoptosis as compared to HDL2a (29% and 28%; p<0.01 vs. HDL3c, respectively) and 2b subfractions (25% and 62%; p<0.001 vs. HDL3c, respectively). All HDL subfractions attenuated of reactive oxygen species (ROS) generation in HMEC induced by oxLDL. Again, HDL3c (54% inhibition) were more potent as compared to HDL2b (21%; p<0.05 vs. HDL3c). The anti-apoptotic and intracellular antioxidative activities of HDL3 were positively correlated with apoA-I and sphingosine 1-phosphate (S1P) content of sHDL and, possibly, depend on their cellular interaction through apoA-I and its SR-BI receptor. The sHDL3c isolated from MetS patients (n=5) possess reduced content of apoA-I and less potent anti-apoptotic activity (-60%, p<0.01) than controls (n=5). Conclusion: Normolipidemic small dense HDL3 provide potent protection of human endothelial cells from oxLDL-induced apoptosis; this anti-apoptotic activity is reduced in the MetS.

Facilitative interaction between angiotensin II and oxidised LDL in cultured human coronary artery endothelial cells.

Background Several studies have shown that angiotensin II (Ang II) and oxidised low-density lipoprotein (ox-LDL) are critical factors in atherosclerosis. In this study, we examined the molecular basis of mutually facilitative interactions between Ang II and ox-LDL in human coronary artery endothelial cells (HCAECs). Methods and results We observed that incubation of cultured HCAECs with Ang II (10-12 to 10-6 M) for 24 hours caused a concentration-dependent increase in the expression of mRNA and protein of a specialised receptor for ox-LDL (LOX-1). These effects of Ang II were completely blocked by pretreatment of HCAECs with candesartan (10-6 M), a specific AT1-receptor blocker, but not by PD 123319 (10-6 M), a specific AT2-receptor blocker. On the other hand, incubation of HCAECs with ox-LDL (10 and 40 µg/ml) for 24 hours progressively upregulated AT1-, but not AT 2-, receptor mRNA and protein. Pretreatment of cells with the anti-oxidant alpha-tocopherol (1-5 x 10-6 M) inhibited the upregulation of AT1-receptor expression induced by ox-LDL (p<0.05). To determine the significance of expression of AT1-receptors and LOX-1, we measured cell injury in response to Ang II and ox-LDL. Incubation of cells with both ox-LDL and Ang II synergistically increased cell injury, measured as cell viability and LDH release, compared with either ox-LDL or Ang II alone (both p<0.05). Alpha-tocopherol, as well as candesartan, attenuated cell injury in response to Ang II and ox-LDL (both p<0.05). Conclusions These observations show that Ang II upregulates a novel endothelial receptor for ox-LDL (LOX-1) gene expression and ox-LDL in turn upregulates Ang II AT 1receptor gene expression. This interaction between Ang II and ox-LDL further augments cell injury in HCAECs. These findings provide basis for the use of AT1-receptor blockers and anti-oxidants in designing therapy for atherosclerosis and myocardial ischaemia.