Aortic Cholesterol Research Articles

Gsα Regulates Macrophage Foam Cell Formation During Atherosclerosis.

Many cardiovascular pathologies are induced by signaling through G-protein-coupled receptors via Gsα (G protein stimulatory α subunit) proteins. However, the specific cellular mechanisms that are driven by Gsα and contribute to the development of atherosclerosis remain unclear. High-throughput screening involving data from single-cell and bulk sequencing were used to explore the expression of Gsα in atherosclerosis. The differentially expression and activity of Gsα were analyzed by immunofluorescence and cAMP measurements. Macrophage-specific Gsα knockout (Mac-GsαKO) mice were generated to study the effect on atherosclerosis. The role of Gsα was determined by transplanting bone marrow and performing assays for foam cell formation, Dil-ox-LDL (oxidized low-density lipoprotein) uptake, chromatin immunoprecipitation, and luciferase reporter assays. ScRNA-seq showed elevated Gnas in atherosclerotic mouse aorta's cholesterol metabolism macrophage cluster, while bulk sequencing confirmed increased GNAS expression in human plaque macrophage content. A significant upregulation of Gsα and active Gsα occurred in macrophages from human and mouse plaques. Ox-LDL could translocate Gsα from macrophage lipid rafts in short-term and promote Gnas transcription through ERK1/2 activation and C/EBPβ phosphorylation via oxidative stress in long-term. Atherosclerotic lesions from Mac-GsαKO mice displayed decreased lipid deposition compared with those from control mice. Additionally, Gsα deficiency alleviated lipid uptake and foam cell formation. Mechanistically, Gsα increased the levels of cAMP and transcriptional activity of the cAMP response element binding protein, which resulted in increased expression of CD36 and SR-A1. In the translational experiments, inhibiting Gsα activation with suramin or cpGN13 reduced lipid uptake, foam cell formation, and the progression of atherosclerotic plaques in mice in vivo. Gsα activation is enhanced during atherosclerotic progression and increases lipid uptake and foam cell formation. The genetic or chemical inactivation of Gsα inhibit the development of atherosclerosis in mice, suggesting that drugs targeting Gsα may be useful in the treatment of atherosclerosis.

Dietary Grape Seed Tannins Affect Lipoproteins, Lipoprotein Lipases and Tissue Lipids in Rats Fed Hypercholesterolemic Diets , ,

The effects of monomeric and polymeric grape seed tannins on rat plasma lipoproteins, lipoprotein lipase, hepatic lipase and aortic and hepatic lipid concentration were studied. Male Sprague-Dawley rats received either a normal diet (with no added cholesterol and no tannins), a control diet (hypercholesterolemic diet) or hypercholesterolemic diets supplemented with 2% tannin monomers or 2% polymers 3 or 9 wk. Plasma total cholesterol, triacylglycerol, LDL cholesterol and VLDL concentrations were significantly higher and the HDL cholesterol concentration lower in controls and in rats fed the diet supplemented with monomers compared with rats fed polymeric tannins at both time points. Lipoprotein lipase and hepatic lipase activities were significantly higher in control and in monomer-fed groups than in the polymer-fed group. Hepatic and aortic cholesterol and triacylglycerol concentrations were significantly higher in control rats and those fed monomers than in the polymer-fed group. Moreover, plasma HDL cholesterol and hepatic lipase activity were closely associated with low aortic cholesterol and triacylglycerol in rats fed polymeric tannins. These rats also exhibited greater fecal excretion of cholesterol and especially bile acids than the control or monomer-fed groups. Thus dietary grape seed tannins have a pronounced anti-hypercholesterolemic effect by enhancing reverse cholesterol transport and also by reducing intestinal cholesterol absorption and increasing bile acid excretion.

Differential distribution of cholesterol pools across arteries under high-cholesterol diet

Excessive cholesterol constitutes a major risk factor for vascular disease. Within cells, cholesterol is distributed in detergent-sensitive and detergent-resistant fractions, with the largest amount of cholesterol residing in cellular membranes. We set out to determine whether various arteries differ in their ability to accumulate esterified and non-esterified cholesterol in detergent-sensitive versus detergent-resistant fractions throughout the course of a high-cholesterol diet. Male Sprague-Dawley rats were placed on 2 % cholesterol diet while a control group was receiving iso-caloric standard chow. Liver, aorta, and pulmonary, mesenteric, and cerebral arteries were collected at 2–6, 8–12, 14–18, and 20–24 weeks from the start of high-cholesterol diet. After fraction separation, esterified and free non-esterified cholesterol levels were measured. In all arteries, largest cholesterol amounts were present in detergent-sensitive fractions in the non-esterified form. Overall, cholesterol in aorta and cerebral arteries was elevated during 14–18 weeks of high-cholesterol diet. Cerebral arteries also exhibited increase in esterified cholesterol within detergent-sensitive domains, as well as increase in cholesterol level in the detergent-resistant fraction at earlier time-points of diet. Pulmonary artery and mesenteric artery were largely resistant to cholesterol accumulation. Quantitative polymerase chain reaction (qPCR) analysis revealed up-regulation of low-density lipoprotein receptor (Ldlr) and low-density lipoprotein receptor-related protein 1 (Lrp1) gene expression in cerebral arteries when compared to mesenteric and pulmonary arteries, respectively. In summary, we unveiled the differential ability of arteries to accumulate cholesterol over the course of a high-cholesterol diet. The differential accumulation of cholesterol seems to correlate with the up-regulated gene expression of proteins responsible for cholesterol uptake.

Ractopamine at legal residue dosage accelerates atherosclerosis by inducing endothelial dysfunction and promoting macrophage foam cell formation

Ractopamine, a synthetic β-adrenoreceptor agonist, is used as an animal feed additive to increase food conversion efficiency and accelerate lean mass accretion in farmed animals. The U.S. Food and Drug Administration claimed that ingesting products containing ractopamine residues at legal dosages might not cause short-term harm to human health. However, the effect of ractopamine on chronic inflammatory diseases and atherosclerosis is unclear. Therefore, we investigated the effects of ractopamine on atherosclerosis and its action mechanism in apolipoprotein E-null (apoe−/−) mice and human endothelial cells (ECs) and macrophages. Daily treatment with ractopamine for four weeks increased the body weight and the weight of brown adipose tissues and gastrocnemius muscles. However, it decreased the weight of white adipose tissues in apoe−/− mice. Additionally, ractopamine exacerbated hyperlipidemia and systemic inflammation, deregulated aortic cholesterol metabolism and inflammation, and accelerated atherosclerosis. In ECs, ractopamine treatment induced endothelial dysfunction and increased monocyte adhesion and transmigration across ECs. In macrophages, ractopamine dysregulated cholesterol metabolism by increasing oxidized low-density lipoprotein (oxLDL) internalization and decreasing reverse cholesterol transporters, increasing oxLDL-induced lipid accumulation. Collectively, our findings revealed that ractopamine induces EC dysfunction and deregulated cholesterol metabolism of macrophages, which ultimately accelerates atherosclerosis progression.

Protective properties of sardine and chickpea protein hydrolysates against lipoprotein oxidative damages and some inflammation markers in hypercholesterolemic rats

OBJECTIVE: This study evaluated the effect of sardine (SPH) and chickpea protein hydrolysates (CPH) on oxidant stress and inflammatory profile in cholesterol-fed rats. METHODS: The experiment was undertaken for thirty days on 18 cholesterol-fed Wistar rats (220±10 g) divided into three groups and receiving 1 g/kg of body weight either chickpea protein hydrolysate (CPH), sardine protein hydrolysate (SPH) or casein in water (CG). RESULTS: Compared to CG, SPH and CPH treatment reduced cholesterol, hydroperoxide and malondialdehyde contents in serum, lipoproteins, erythrocytes and aorta. These same treated groups showed also lower serum isoprostane levels. However, serum paraoxonase activity and HDL-antioxidant property were improved only by CPH compared to CG. SOD activity of aorta and erythrocytes was higher in CPH but in SPH group, SOD activity was lower in these tissues and remained unchanged in serum. Furthermore, CPH and SPH stimulated glutathione peroxidase and catalase activities of aorta and erythrocytes. In CPH group, nitric oxide levels of serum, erythrocytes and aorta were increased by respectively 1.4- to 1.8-fold compared to CG and SPH. In addition, among the three groups, CPH exhibited the best anti-inflammatory effect by lowering serum C reactive protein, uric acid and albumin concentrations. CONCLUSIONS: SPH and particularly CPH possess antioxidant and anti-inflammatory properties and could be useful as nutraceuticals for health improving and preventing numerous disorders such as cardiovascular diseases.

Complex of tris(2-hydroxyethyl)amine with zinc bis[(2-methylphenoxy)acetate] as an aortic cholesterol esterase inhibitor in the experiment

Complex of tris(2-hydroxyethyl)amine with zinc bis[(2-methylphenoxy)acetate] as an aortic cholesterol esterase inhibitor in the experiment

Spirulina liquid extract prevents metabolic disturbances and improves liver sphingolipids profile in hamster fed a high-fat diet.

Metabolic syndrome is characterized by hyperglycemia, hyperlipemia and exacerbated oxidative stress. The aim of the study was to determine whether Spirulysat®, a Spirulina liquid extract (SLE) enriched in phycocyanin, would prevent metabolic abnormalities induced by high-fat diet. The effect of acute SLE supplementation on postprandial lipemia and on triton-induced hyperlipidemia was studied in hamster fed control diet (C). The effect of chronic SLE supplementation on lipid content in plasma, liver and aorta, and on glycemia and oxidative stress was studied in hamster fed control (C) or high-fat diet (HF) for two weeks and then treated with SLE for two weeks (CSp and HFSp) or not (C and HF). The acute SLE supplementation lowered plasma cholesterol and non-esterified fatty acid concentrations after olive oil gavage (P < 0.05) in CSp, while no effect was observed on triglyceridemia. HFD increased plasma MDA, basal glycemia, triglyceridemia, total plasma cholesterol, VLDL, LDL and HDL cholesterol, ceramide, sphingomyelin and glucosylceramide content in liver in HF compared to C (P < 0.05). SLE did not affect SOD and GPx activities nor total antioxidant status in HFSp group but lowered glycemia, glucoceramide and cholesterol in liver and cholesterol in aorta compared to HF (P < 0.05). SLE also decreased HMGCoA and TGF-β1 gene expression in liver (P < 0.05) and tended to lower G6Pase (P = 0.068) gene expression in HFSp compared to HF. Although 2-week SLE supplementation did not affect oxidative stress, it protected from hyperglycemia and lipid accumulation in liver and aorta suggesting a protective effect against metabolic syndrome.

Adverse Effects of Oseltamivir Phosphate Therapy on the Liver of LDLR-/- Mice Without Any Benefit on Atherosclerosis and Thrombosis.

Desialylation, governed by sialidases or neuraminidases, is strongly implicated in a wide range of human disorders, and accumulative data show that inhibition of neuraminidases, such as neuraminidases 1 sialidase, may be useful for managing atherosclerosis. Several studies have reported promising effects of oseltamivir phosphate, a widely used anti-influenza sialidase inhibitor, on human cancer cells, inflammation, and insulin resistance. In this study, we evaluated the effects of oseltamivir phosphate on atherosclerosis and thrombosis and potential liver toxicity in LDLR-/- mice fed with high-fat diet. Our results showed that oseltamivir phosphate significantly decreased plasma levels of LDL cholesterol and elastin fragmentation in aorta. However, no effect was observed on both atherosclerotic plaque size in aortic roots and chemically induced thrombosis in carotid arteries. Importantly, oseltamivir phosphate administration had adverse effects on the liver of mice and significantly increased messenger RNA expression levels of F4/80, interleukin-1β, transforming growth factor-β1, matrix metalloproteinase-12, and collagen. Taken together, our findings suggest that oseltamivir phosphate has limited benefits on atherosclerosis and carotid thrombosis and may lead to adverse side effects on the liver with increased inflammation and fibrosis.

Benefits of Anthocyanin-Rich Black Rice Fraction and Wood Sterols to Control Plasma and Tissue Lipid Concentrations in Wistar Kyoto Rats Fed an Atherogenic Diet.

Background: This study reports on the relative effects of administrating a cyanidin-3-O-glucoside-rich black rice fraction (BRF), a standardized wood sterol mixture (WS), and a combination of both to lower plasma and target tissue lipid concentrations in Wistar Kyoto (WKY) rats fed atherogenic diets. Methods: Male WKY (n = 40) rats were randomly divided into five groups, which included a nonatherogenic control diet and atherogenic diets that included a positive control and atherogenic diets supplemented with BRF or WS, respectively, and a combination of both BRF + WS. Plasma and target tissue liver, heart and aorta cholesterol, and triacylglycerides (TAG) content were also measured. Results: Rats fed atherogenic diets exhibited elevated hyperlipidemia compared to counterparts fed nonatherogenic diets (p < 0.001); this effect was mitigated by supplementing the atherogenic diets with BRF and WS, respectively (p < 0.05). Combining BRF with WS to enrich the supplement lowered cholesterol similar to the WS effect (p < 0.05) and lowered TAG characteristic to the BRF effect (p < 0.05). Conclusions: Rats fed diets containing BRF or WS effectively mitigate the hypercholesterolemia and elevated TAG induced by feeding an atherogenic diet. The benefit of adding BRF + WS together is relevant to the lipid parameter measured and is target tissue-specific.

Permethrin induced arterial retention of native and oxidized LDL in rats by promoting inflammation, oxidative stress and affecting LDL receptors, and collagen genes

This study is the first to examine the possible mechanism by which long-term exposure to permethrin (PER) can promote arterial retention of proatherogenic lipid and lipoproteins and related vascular dysfunction in rats. Experimental animals were administered two doses of oral PER, PER-1 (2.5 mg/kg/bw) and PER-2 (5 mg/kg/bw), for 90 consecutive days. The results indicated that both PER-1 and PER-2 increased plasmatic and aortic total cholesterol, low-density lipoprotein cholesterol (LDL-C), apo B-100, and oxidized LDL together with arterial scavenger LDL receptors (CD36) but markedly reduced plasmatic and hepatic high-density lipoprotein cholesterol and native LDL receptors in aortic and hepatic tissue. The levels of malondialdehyde, protein carbonyl, and reactive oxygen species were significantly higher, and glutathione content as well as catalase, superoxide dismutase, and glutathione peroxidase activities were suppressed in the aorta of the PER-1 and PER-2 groups. The arterial oxidative damage possibly caused by PER was clearly demonstrated by hematoxylin and eosin histological analysis. Moreover, PER treatment aggravated the inflammatory responses through enhancement of the production of proinflammatory cytokines (tumor necrosis factor–α, interleukin-2, and interleukin-6) in both plasma and aorta. Furthermore, PER-1 and PER-2 potentiated the dysregulation of the aortic extracellular matrix (ECM) content by increasing mRNA activation of collagens I and III. The abundant histological collagen deposition observed in the media and adventitia of intoxicated rats using Masson's trichrome staining corroborates the observed change in ECM. These data showed that oxidative stress related to PER exposure increases the arterial accumulation of lipoprotein biomarkers, likely by actions on both LDL and CD36 receptors, together with the disruption of the aortic ECM.

Nanoparticle-based “Two-pronged” approach to regress atherosclerosis by simultaneous modulation of cholesterol influx and efflux

Reduction of lipoprotein uptake by macrophages and stimulation of cholesterol efflux are two essential steps required for atherosclerotic plaque regression. We used the optimized mannose-functionalized dendrimeric nanoparticle (mDNP)-based platform for macrophage-specific delivery of therapeutics to simultaneously deliver SR-A siRNA (to reduce LDL uptake) and LXR ligand (LXR-L, to stimulate cholesterol efflux) – a novel “Two-pronged” approach to facilitate plaque regression. mDNP-mediated delivery of SR-A siRNA led to a significant reduction in SR-A expression with a corresponding decrease in uptake of oxLDL. Delivery of LXR-L increased expression of ABCA1/G1 and cholesterol efflux. Combined delivery of siRNA and LXR-L led to a significantly greater decrease in macrophage cholesterol content compared to either treatment alone. Administration of this in vitro optimized formulation of mDNP complexed with SR-A-siRNA and LXR-L (Two-pronged complex) to atherosclerotic LDLR−/− mice fed western diet (TD88137) led to significant regression of atherosclerotic plaques with a corresponding decrease in aortic cholesterol content.

Cholesterol induced heart valve inflammation and injury: efficacy of cholesterol lowering treatment

BackgroundHeart valves often undergo a degenerative process leading to mechanical dysfunction that requires valve replacement. This process has been compared with atherosclerosis because of shared pathology and risk factors. In...

Alterations in Copper Homeostasis in Rabbit Model of Atherosclerosis

Copper concentrations decrease in atherosclerotic tissues. The present study was undertaken to determine overall alterations in copper homeostasis in the pathogenesis of atherosclerosis. New Zealand white rabbits, aged 10‐weeks‐old, were fed a rodent chow diet containing 1% (w/w) cholesterol or the same diet without cholesterol as control. Twelve weeks after respective diet feeding, the animals were euthanatized by sodium pentobarbital. Rabbits fed cholesterol‐containing diet developed hyperlipemic as defined by a significant increase in the total plasma cholesterol and atherosclerotic lesions in aorta. Copper concentrations in the atherosclerotic tissues were significantly decreased while serum copper concentrations were increased in the hyperlipemic animals in comparison with controls. A detailed analysis revealed that copper concentration in abdominal aorta of the hyperlipemic rabbits was negatively correlated with the severity of the atherosclerotic lesion, stenosis of the lumen area, and collagen deposition. In addition, copper concentrations in the kidney of hyperlipemic rabbits were increased, but in the heart, liver, spleen and lung were decreased. These results suggest that in the pathogenesis of atherosclerosis, changes in copper homeostasis are not only observable in the atherosclerotic tissues, but also in multiple organ systems. These changes would be additive to atherosclerosis as a high risk of cardiovascular disease in humans.Support or Funding InformationWest China Hospital, Sichuan University(A) The percentage of the aortae staining positively for lipid(Longitudinal of suprarenal abdominal aortae was stained with oil red O). Sections of infrarenal abdominal aortae were stained with EVG for microscopic quantification of lesion areas, (B) the atherosclerotic lesion area and (C) the percent of stenosis of lumen area. Collagen fibers in the lesions were assessed by picrosirius red staining, the percent of Collagen in lesion area. (*P &lt; 0.05)Figure 1The concentration of copper in tissues and plasma.(A) cardiac copper concentration; (B) liver copper concentration; (C) spleen copper concentration; (D) lung copper concentration; (E) kidney copper concentration; (F) duodenum copper concentration; (G) abdominal aortic copper; (H) plasma copper concentration. (*P &lt; 0.05)Figure 2

Zygophyllum album saponins prevent atherogenic effect induced by deltamethrin via attenuating arterial accumulation of native and oxidized LDL in rats.

The current study aimed to examine, for the first time, the relationship between exposure to deltamethrin (DLM) and atherogenic lipid profile disorders in adult Wistar rats, as well as, to verify the mechanism of the beneficial role of Zygophyllum album leaves extracts (ZALE). The experimental study was assessed using DLM (4mg/kg b.w) either alone or co administered with ZALE (400mg/kg b.w) orally for 90 days in rats. RP-HPLC-DAD-ESI-QTOF-MS was used to identify the bioactive metabolites present in ZALE. Plasmatic and aortic total cholesterol (TC), LDL-cholesterol (LDL-C), native LDL (LDL-apo B-100) and oxidized LDL (ox-LDL) were evaluated using auto-analyzer and a sandwich ELISA, respectively. The protein expressions of LDLR (native LDL receptor) and CD36 (Scavenger receptor class B) were evaluated in aorta or liver with a Western blot. The pathology has been confirmed with lipid stain (Oil Red O). Phytochemicals analysis revealed the presence of fifteen saponins in ZALE. Rats intoxicated with DLM revealed a significant increase in plasmatic and aortic lipid profile (TC, LDL-C, LDL-apo B-100 and ox-LDL), as well as, the concentration of the plasmatic cytokines include TNF-α, IL-2 and IL-6, compared to control. Hepatic native LDL and aortic CD36 receptor expression were increased in DLM treated group, however aortic LDL-R does not present any modification, when compared to control. The detected disturbances in lipid parameters were supported by Oil Red O applied. Due to their antioxidant activity, the bioactive compounds in ZALE as powerful agents able to prevent the pro-atherogenic effect observed in DLM-treated animals. These metabolites modulated most of inflammatory markers, prevented accumulation of lipid and lipoprotein biomarkers, regulated the major receptor regulators of hepatic cholesterol metabolism, as well as normalize lipid distribution in liver and aorta tissue.

The effect of lanthanum carbonate on calciprotein particles in hemodialysis patients

BackgroundAggregation of solid-phase calcium–phosphate and fetuin-A form nanoparticles called calciprotein particles (CPP). Serum CPP levels are increased in CKD patients and correlated with vascular stiffness and calcification. In this study, we evaluated effects of lanthanum carbonate (LC) and calcium carbonate (CC) on serum CPP levels in hemodialysis (HD) patients.MethodsTwenty-four (24) HD patients (50% men, age; 68 ± 12 years, dialysis period; 6.2 ± 4.8 years, Kt/v; 1.74 ± 0.34) were treated with CC during 0–8 weeks and then switched to LC during 9–16 weeks. Blood samples were obtained at 0, 8, 16 weeks. Serum CPP levels (TCPP) were measured by the gel-filtration method. Low-density CPP (LCPP) levels were determined by centrifuging the serum samples at 16,000 g for 2 h and measuring CPP levels in the supernatant. The difference between TCPP and LCPP was defined as the high-density CPP (HCPP) level. We evaluated association of TCPP, LCPP, and HCPP with serum calcium (Ca), phosphorus (P), intact PTH, FGF23, Klotho, fetuin-A, aortic calcification index (ACI), LDL cholesterol, and hs-CRP.ResultsTCPP and LCPP levels were significantly decreased after switching CC to LC, whereas Ca and P levels were not changed. HCPP levels were below the lower limit quantification in all patients. The changes in P, Ca × P, LDL cholesterol, but not ACI and the changes in hs-CRP, were correlated with the change in TCPP levels.ConclusionThe TCPP levels were significantly decreased after switching CC to LC. Non-calcium-containing phosphate binders may be preferable for lowering CPP levels.

Bifenthrin exerts proatherogenic effects via arterial accumulation of native and oxidized LDL in rats: the beneficial role of vitamin E and selenium.

The purpose of this study was to investigate, for the first time, the effects of Bifenthrin (Bif) chronic exposure on plasmatic and aortic lipid parameters disturbance and their pro-atherogenic possibility in Wistar rats. The ameliorative role of vitamin E (Vit E) and selenium (Se) were also targeted. Thus, rats were treated by gastric gavage with combination of Vit E (100mg/kg/bw) and Se (0.25mg/kg/bw) in alone and co-treated groups for 90days. Apart from control and Vit E-Se groups, all the groups were subjected to Bif (3mg/kg, via gavage) toxicity. Results showed that Bif increased markedly plasmatic and aortic total cholesterol, LDL-cholesterol, native LDL-apoB-100, and oxidized-LDL, compared to the control. Moreover, Bif treatment significantly increased the plasmatic levels of the pro-inflammatory cytokines TNF-α, IL-2, and IL-6. In addition, the densitometric quantification of protein bands showed that the amount of hepatic native LDL-receptor protein decreased significantly in the intoxicated rats compared to the control group. The expression of arterial LDL receptors (LDLRs) and scavenger receptors (CD36) was amplified owing to Bif toxicity. This harmful effect was confirmed by histological study using Oil-Red-O staining. Owing to their antioxidant capacities, Vit E and Se have maintained all the changes in plasma and aorta lipids and prevented the pro-atherogenic effect observed in Bif-treated animals.

Exogenous (Pomegranate Juice) or Endogenous (Paraoxonase1) Antioxidants Decrease Triacylglycerol Accumulation in Mouse Cardiovascular Disease-Related Tissues.

The polyphenol-rich pomegranate juice (PJ) and the high-density lipoprotein (HDL)-associated paraoxonase1 (PON1) are known as potent atheroprotective antioxidants, but their effects on other tissues related to cardiovascular disease (CVD) remain unknown. The current study aimed to investigate the effects of treating mice with PJ or recombinant PON1 (rePON1) on the oxidation and lipid status of CVD-related tissues: serum, aorta, heart, liver, kidney, visceral, and subcutaneous adipose tissues (VAT and SAT). Both PJ consumption and rePON1 injection decreased the serum levels of thiobarbituric acid-reactive substances (16% and 19%) and triacylglycerols (TAG, 24% and 27%), while only rePON1 increased the levels of thiol groups (35%) and decreased serum cholesterol (15%). Both PJ and rePON1 significantly decreased aortic cholesterol (38% and 32%) and TAG (62% and 58%) contents in association with downregulation of the key TAG biosynthetic enzyme diacylglycerol O-acyltransferase 1 (DGAT1, 71% and 65%), while only PJ decreased aortic lipid peroxides (47%). Substantial TAG-lowering effects of both PJ and rePON1 were observed also in the heart (31% and 42%), liver (34% and 42%), and kidney (42% and 57%). In both VAT and SAT, rePON1 decreased the levels of lipid peroxides (28% and 25%), while PJ decreased the TAG content (22% and 18%). Ex vivo incubation of SAT with serum derived from mice that consumed PJ or injected with rePON1 decreased SAT lipid peroxides (35% or 28%) and TAG mass (12% or 10%). These novel findings highlight potent TAG-lowering properties of exogenous (PJ) and endogenous (PON1) antioxidants in tissues associated with CVD.

Lack of Correlation of Plasma HDL With Fecal Cholesterol and Plasma Cholesterol Efflux Capacity Suggests Importance of HDL Functionality in Attenuation of Atherosclerosis.

A number of clinical findings suggested HDL-raising as a plausible approach to treat residual risk of CVD. However, lack of CVD risk reduction by elevated HDL cholesterol (HDL-C) through cholesterol ester transfer protein (CETP) inhibition and enhanced risk reduction in apolipoprotein A-I Milano (apoAI-M) individuals with low HDL-C shifted the focus from HDL-C level to HDL function. In the present study, we investigated correlations between HDL-C, HDL function, fecal cholesterol excretion, and ex vivo plasma cholesterol efflux capacity (CEC) in animal models using two HDL modulators, LXR and PPAR-α agonists. In C57Bl mice, LXR agonist, T1317, raised HDL-C by 30%, while PPAR-α agonist, fenofibrate, reduced HDL-C by 30%, but fecal cholesterol showed twofold increase in both cases. CEC showed a 30–40% increase. Combination of LXR and PPAR-α agonists showed no changes in HDL-C, but, interestingly, fecal cholesterol increased by 4.5-fold, and CEC by 40%, suggesting existence of additional pathway for fecal cholesterol excretion. Regression analysis showed a lack of correlation between HDL-C and fecal cholesterol and CEC, while fecal cholesterol showed significant correlation with CEC, a measure of HDL function. ABCA1 and G1, the two important players in RCT showed greater induction with LXR agonist than PPAR-α agonist. HDL-C increased by 40 and 80% in LXR and PPAR-α treated apoA-I transgenic mice, respectively, with 80% increase in fecal cholesterol. A fivefold increase in fecal cholesterol with no correlation with either plasma HDL-C or CEC following co-treatment with LXR and PPAR-α agonists suggested existence of an HDL-independent pathway for body cholesterol elimination. In hyperlipidemic diabetic ob/ob mice also combination of LXR and PPAR-α agonists showed marked increases in fecal cholesterol content (10–20-fold), while HDL-C rise was only 40%, further suggesting HDL-independent elimination of body cholesterol in mice treated with combination of LXR and PPAR-α agonists. Atherosclerosis attenuation by LXR and PPAR-α agonists in LDLr-deficient mice was associated with increased fecal cholesterol, but not HDL-C. However, fecal cholesterol counts showed inverse correlation with aortic cholesteryl ester content. These data suggest: (a) lack of correlation between HDL-C and fecal or aortic cholesterol content; (b) HDL function (CEC) correlated with fecal cholesterol content; (c) association of reduced aortic lipids in LDLr−/− mice with increased fecal cholesterol, but not with HDL-C, and (d) existence of an HDL-independent pathway for fecal cholesterol excretion following co-treatment with LXR and PPAR-α agonists.

Unraveling the Interaction of Aspirin, Ticagrelor, and Rosuvastatin on the Progression of Atherosclerosis and Inflammation in Diabetic Mice.

We explored the effects of rosuvastatin, aspirin, ticagrelor, and clopidogrel, alone or in combinations on the progression of atherosclerosis and inflammasome activation in diabetic mice. Statins and ticagrelor increase the production of 15-epi-lipoxin A4 via cyclooxygenase-2. Aspirin alone increases 15-epi-lipoxin A4, but when combined with statins, cyclooxygenase-2 is completely blocked. ApoE-/-/db+/db+ double-knockout mice received rosuvastatin (5mg/kg/day), aspirin (25mg/kg/day), ticagrelor (300mg/kg/day), clopidogrel (75mg/kg/day), or their combination for 14weeks. Serum 15-epi-lipoxin A4 levels and aortic wall cholesterol content, IL-1β, IL-6, and TNF-α levels, and plaque area were assessed. Aspirin, ticagrelor, and rosuvastatin increased 15-epi-lipoxin A4 levels. The combination of rosuvastatin + ticagrelor provided an additive effect. Aspirin attenuated the effect of both ticagrelor and rosuvastatin. Aspirin, ticagrelor, and rosuvastatin reduced the area of the atherosclerotic plaque. The combination of ticagrelor + rosuvastatin provided additive effects. There was a negative interaction when aspirin was combined with ticagrelor or rosuvastatin. Aspirin, ticagrelor, and rosuvastatin decreased serum IL-1β and IL-6 levels. There was no interaction between aspirin and ticagrelor or aspirin and rosuvastatin, whereas combining rosuvastatin and ticagrelor provided an additive effect. Aspirin, ticagrelor, and rosuvastatin all decreased TNF-α levels. Aspirin attenuated the effect of both ticagrelor and rosuvastatin, and there was no additive effect of combining ticagrelor + rosuvastatin. We found an intricate interaction between aspirin, ticagrelor, and rosuvastatin, as aspirin reduced both ticagrelor and rosuvastatin ability to ameliorate inflammation and atherosclerosis. In contrast, we found additive effects when ticagrelor and rosuvastatin were combined.

Aerobic Exercise Training Selectively Changes Oxysterol Levels and Metabolism Reducing Cholesterol Accumulation in the Aorta of Dyslipidemic Mice.

Background: Oxysterols are bioactive lipids that control cellular cholesterol synthesis, uptake, and exportation besides mediating inflammation and cytotoxicity that modulate the development of atherosclerosis. Aerobic exercise training (AET) prevents and regresses atherosclerosis by the improvement of lipid metabolism, reverse cholesterol transport (RCT) and antioxidant defenses in the arterial wall. We investigated in dyslipidemic mice the role of a 6-week AET program in the content of plasma and aortic arch cholesterol and oxysterols, the expression of genes related to cholesterol flux and the effect of the exercise-mimetic AICAR, an AMPK activator, in macrophage oxysterols concentration.Methods: Sixteen-week old male apo E KO mice fed a chow diet were included in the protocol. Animals were trained in a treadmill running, 15 m/min, 5 days/week, for 60 min (T; n = 29). A control group was kept sedentary (S; n = 32). Plasma lipids and glucose were determined by enzymatic techniques and glucometer, respectively. Cholesterol and oxysterols in aortic arch and macrophages were measured by gas chromatography/mass spectrometry. The expression of genes involved in lipid metabolism was determined by RT-qPCR. The effect of AMPK in oxysterols metabolism was determined in J774 macrophages treated with 0.25 mM AICAR.Results: Body weight and plasma TC, TG, HDL-c, glucose, and oxysterols were similar between groups. As compared to S group, AET enhanced 7β-hydroxycholesterol (70%) and reduced cholesterol (32%) in aorta. In addition, exercise increased Cyp27a1 (54%), Cd36 (75%), Cat (70%), Prkaa1 (40%), and Prkaa2 (51%) mRNA. In macrophages, the activation of AMPK followed by incubation with HDL2 increased Abca1 (52%) and Cd36 (220%) and decrease Prkaa1 (19%), Cyp27a1 (47%) and 7α-hydroxycholesterol level.Conclusion: AET increases 7β-hydroxycholesterol in the aortic arch of dyslipidemic mice, which is related to the enhanced expression of Cd36. In addition, the increase and reduction of Cyp27a1 and Cyp7b1 in trained mice may contribute to enhance levels of 27-OH C. Both oxysterols may act as an alternative pathway for the RCT contributing to the reduction of cholesterol in the aortic arch preventing atherogenesis.