42 research outputs found

    Aerobic exercise training enhances the in vivo cholesterol trafficking from macrophages to the liver independently of changes in the expression of genes involved in lipid flux in macrophages and aorta

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    Abstract\ud \ud Background\ud Regular exercise prevents and regresses atherosclerosis by improving lipid metabolism and antioxidant defenses. Exercise ameliorates the reverse cholesterol transport (RCT), an antiatherogenic system that drives cholesterol from arterial macrophages to the liver for excretion into bile and feces. In this study we analyzed the role of aerobic exercise on the in vivo RCT and expression of genes and proteins involved in lipid flux and inflammation in peritoneal macrophages, aortic arch and liver from wild type mice.\ud \ud \ud Methods\ud Twelve-week-old male mice were divided into sedentary and trained groups. Exercise training was performed in a treadmill (15 m/min, 30 min/day, 5 days/week). Plasma lipids were determined by enzymatic methods and lipoprotein profile by fast protein liquid chromatography. After intraperitoneal injection of J774-macrophages the RCT was assessed by measuring the recovery of 3H-cholesterol in plasma, feces and liver. The expression of liver receptors was determined by immunoblot, macrophages and aortic mRNAs by qRT-PCR. 14C-cholesterol efflux mediated by apo A-I and HDL2 and the uptake of 3H-cholesteryl oleoyl ether (3H-COE)-acetylated-LDL were determined in macrophages isolated from sedentary and trained animals 48 h after the last exercise session.\ud \ud \ud Results\ud Body weight, plasma lipids, lipoprotein profile, glucose and blood pressure were not modified by exercise training. A greater amount of 3H-cholesterol was recovered in plasma (24 h and 48 h) and liver (48 h) from trained animals in comparison to sedentary. No difference was found in 3H-cholesterol excreted in feces between trained and sedentary mice. The hepatic expression of scavenger receptor class B type I (SR-BI) and LDL receptor (B-E) was enhanced by exercise. We observed 2.8 and 1.7 fold rise, respectively, in LXR and Cyp7a mRNA in the liver of trained as compared to sedentary mice. Macrophage and aortic expression of genes involved in lipid efflux was not systematically changed by physical exercise. In agreement, 14C-cholestrol efflux and uptake of 3H-COE-acetylated-LDL by macrophages was similar between sedentary and trained animals.\ud \ud \ud Conclusion\ud Aerobic exercise in vivo accelerates the traffic of cholesterol from macrophages to the liver contributing to prevention and regression of atherosclerosis, independently of changes in macrophage and aorta gene expression.Fundação de Amparo à Pesquisa do Estado de Sao Paulo - FAPESP 12/04831-1 to MP, UFM and MLCCG; FAPESP 07/50387-8 to MP, 2011/15153-1 to PR, 06/52702-5 to DDFMRocco, 13/02854-7 to LS\ud Okuda, 12/19112-0 to AML, 10/50108-4 to GC, 12/18724-2 to KS, 11/04631-0 to DJG, 09/53412-9 to RS Pinto; 12/12088-7 to RTI, 14/07155 to GFConselho Nacional de Desenvolvimento Científico e Tecnológico (158314/\ud 2014-0 to DJG

    Advanced glycated albumin impairs HDL anti-inflammatory activity and primes macrophages for inflammatory response that reduces reverse cholesterol transport

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    Objective: We investigated the effect of advanced glycated albumin (AGE-albumin) on macrophage sensitivity to inflammation elicited by S100B calgranulin and lipopolysaccharide (LPS) and the mechanism by which HDL modulates this response. We also measured the influence of the culture medium, isolated from macrophages treated with AGE-albumin, on reverse cholesterol transport (RCT). Methods and results: Macrophages were incubated with control (C) or AGE-albumin in the presence or absence of HDL, followed by incubations with S100B or LPS. Also, culture medium obtained from cells treated with C- or AGE-albumin, following S100B or LPS stimulation was utilized to treat naive macrophages in order to evaluate cholesterol efflux and the expression of HDL receptors. In comparison with C-albumin, AGE-albumin, promoted a greater secretion of cytokines after stimulation with S100B or LPS. A greater amount of cytokines was also produced by macrophages treated with AGE-albumin even in the presence of HDL Cytokine-enriched medium, drawn from incubations with AGE-albumin and S100B or LPS impaired the cholesterol efflux mediated by apoA-I (23% and 37%, respectively), HDL2 (43% and 47%, respectively) and HDL3 (20% and 8.5%, respectively) and reduced ABCA-1 protein level (16% and 26%, respectively). Conclusions: AGE-albumin primes macrophages for an inflammatory response impairing the RCT. Moreover, AGE-albumin abrogates the anti-inflammatory role of HDL, which may aggravate the development of atherosclerosis in DM. (C) 2012 Elsevier BM. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [09/53869-9]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)FAPESPFAPESP [10/50147-0, 10/50108-4, 06/52702-5

    Chromatographic analysis of lipid fractions in healthy dogs and dogs with obesity or hyperadrenocorticism

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    Obesity and endogenous hyperadrenocorticism (HAC) are common clinical conditions in veterinary practice, and both conditions have clinical and laboratory similarities, Such as weight gain and dyslipidemia. The objective of the present study was to characterize and compare the lipid profiles and plasma lipoprotein fractions in healthy dogs (n = 10), in obese dogs (n = 10), and in dogs with HAC (n = 6). All of the dogs were client owned. The lipoproteins were separated by fast protein liquid chromatography, and the plasma concentrations of total cholesterol and total triacylglycerol (TAG) were determined by enzymatic methods. When compared with the healthy and obese groups, dogs with HAC had a significant increase (P < 0.01) in the total concentrations of TAGs and cholesterol (CHOL), with higher distribution in the very low-density lipoprotein (VLDL)-CHOL fractions. In addition, the distributions of the high-density lipoprotein (HDL)-CHOL and HDL-TAG fractions were significantly lower (P < 0.01) in dogs with HAC than in healthy dogs. Considering the animals in this study, it was determined that the dogs with HAC differed significantly from the healthy and obese dogs regarding the metabolism of CHOL and TAG, as well as their VLDL and HDL fractions. Similar laboratory findings could allow veterinarians to distinguish obese dogs from those with HAC. In addition, dogs with HAC may be at higher risk for developing metabolic and atherosclerotic complications

    Experimental diabetes modulates collagen remodelling of joints in rats

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    The aim of this study was to evaluate extracellular matrix components in articular cartilage, ligaments and synovia in an experimental model of diabetes. Young Wistar rats were divided into a streptozotocin-induced (STZ; 35 mg/kg) diabetic group (DG; n=15) and a control group (CG; n=15). Weight, blood glucose and plasma anti-carboxymethyllysine were measured 70 days after STZ infusions. Knee joints, patellar ligaments, and lateral and medial collateral ligaments were isolated and stained with hematoxylineosin and Picrosirius. The total collagen content was determined by morphometry. Immunofluorescence was employed to evaluate types I, III, and V collagen in ligaments and synovial tissues and types II and XI collagen in cartilage. Results: Higher blood glucose levels and plasma anti-carboxymethyllysine were observed in DG rats when compared to those in CG rats. The final weight was significantly lower in the DG rats than in the CG rats. Histomorphometric evaluation depicted a small quantity of collagen fibers in ligaments and articular cartilage in DG rats, as well as increased collagen in synovial tissue. There was a decrease in cartilage proteoglycans in DG rats when compared with CG rats. Immunofluorescence staining revealed an increase of collagen III and V in ligaments, collagen XI in cartilage, and collagen I in synovial tissue of DG rats compared with CG rats. Conclusion: The ligaments, cartilage and synovia are highly affected following STZ-induced diabetes in rats, due the remodeling of collagen types in these tissues. This process may promote the degradation of the extracellular matrix, thus compromising joint function. Our data may help to better understand the pathogenesis of joint involvement related to diabetes.Brazilian agency, National Council for Scientific and Technological Development (CNPq)Brazilian agency, Foundation for the Support of Research of the State of Sao Paulo (FAPESP) [2007/59792-2]Brazilian agency, Laboratories for Medical Research (LIMs), University Hospital, School of Medicine, University of Sao Paul

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

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    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

    Aerobic Exercise Training Prevents Insulin Resistance and Hepatic Lipid Accumulation in LDL Receptor Knockout Mice Chronically Fed a Low-Sodium Diet

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    Background: A low-sodium (LS) diet reduces blood pressure, contributing to the prevention of cardiovascular diseases. However, intense dietary sodium restriction impairs insulin sensitivity and worsens lipid profile. Considering the benefits of aerobic exercise training (AET), the effect of LS diet and AET in hepatic lipid content and gene expression was investigated in LDL receptor knockout (LDLr-KO) mice. Methods: Twelve-week-old male LDLr-KO mice fed a normal sodium (NS) or LS diet were kept sedentary (S) or trained (T) for 90 days. Body mass, plasma lipids, insulin tolerance testing, hepatic triglyceride (TG) content, gene expression, and citrate synthase (CS) activity were determined. Results were compared by 2-way ANOVA and Tukey’s post-test. Results: Compared to NS, LS increased body mass and plasma TG, and impaired insulin sensitivity, which was prevented by AET. The LS-S group, but not the LS-T group, presented greater hepatic TG than the NS-S group. The LS diet increased the expression of genes related to insulin resistance (ApocIII, G6pc, Pck1) and reduced those involved in oxidative capacity (Prkaa1, Prkaa2, Ppara, Lipe) and lipoprotein assembly (Mttp). Conclusion: AET prevented the LS-diet-induced TG accumulation in the liver by improving insulin sensitivity and the expression of insulin-regulated genes and oxidative capacity
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