Removal from the plasma of the free and esterified forms of cholesterol and transfer of lipids to HDL in type 2 diabetes mellitus patients

Background: The aim was to investigate new markers for type 2 diabetes (T2DM) dyslipidemia related with LDL and HDL metabolism. Removal from plasma of free and esterified cholesterol transported in LDL and the transfer of lipids to HDL are important aspects of the lipoprotein intravascular metabolism. The plasma kinetics (fractional clearance rate, FCR) and transfers of lipids to HDL were explored in T2DM patients and controls, using as tool a nanoemulsion that mimics LDL lipid structure (LDE). Results: C-14- cholesteryl ester FCR of the nanoemulsion was greater in T2DM than in controls (0.07 +/- 0.02 vs. 0.05 +/- 0.01 h(-1), p = 0.02) indicating that LDE was removed faster, but FCR H-3- cholesterol was equal in both groups. Esterification rates of LDE free-cholesterol were equal. Cholesteryl ester and triglyceride transfer from LDE to HDL was greater in T2DM (4.2 +/- 0.8 vs. 3.5 +/- 0.7%, p = 0.03 and 6.8 +/- 1.6% vs. 5.0 +/- 1.1, p = 0.03, respectively). Phospholipid and free cholesterol transfers were not different. Conclusions: The kinetics of free and esterified cholesterol tended to be independent in T2DM patients and the lipid transfers to HDL were also disturbed. These novel findings may be related with pathophysiological mechanisms of diabetic macrovascular disease.This study was supported by Fundação do Amparo à Pesquisa do Estado de\ud São Paulo (FAPESP), São Paulo, Brazil. Dr. Maranhão has a Research Award\ud from Conselho Nacional de Desenvolvimento Científico e Tecnológico\ud (CNPq) Brasília, Brazil

Drug-targeting in combined cancer chemotherapy: tumor growth inhibition in mice by association of paclitaxel and etoposide with a cholesterol-rich nanoemulsion

Lipid nanoemulsions (LDE) may be used as carriers of paclitaxel (PTX) and etoposide (ETP) to decrease toxicity and increase the therapeutic action of those drugs. The current study investigates the combined chemotherapy with PTX and ETP associated with LDE. Four groups of 10-20 B16F10 melanoma-bearing mice were treated with LDE-PTX and LDE-ETP in combination (LDE-PTX + ETP), commercial PTX and ETP in combination (PTX + ETP), single LDE-PTX, and single LDE-ETP. PTX and ETX doses were 9 mu mol/kg administered in three intraperitoneal injections on three alternate days. In two control groups mice were treated with saline solution or LDE alone. Tumor growth, metastasis presence, cell-cycle distribution, blood cell counts and histological data were analyzed. Toxicity of all treatments was evaluated in mice without tumors. Tumor growth inhibition was similarly strong in all treatment groups. However, there was a greater reduction in the number of animals bearing metastases in the LDE-PTX + ETP group (30 %) in comparison to the PTX + ETP group (82 %, p < 0.05). Reduction of cellular density, blood vessels and increase of collagen fibers in tumor tissues were observed in the LDE-PTX + ETP group but not in the PTX + ETP group, and in both groups reduced melanoma-related anemia and thrombocytosis were observed. Flow cytometric analysis suggested that LDE-PTX + ETP exhibited greater selectivity to neoplastic cells than PTX-ETP, showing arrest (65 %) in the G(2)/M phase of the cell cycle (p < 0.001). Toxicity manifested by weight loss and myelosuppression was markedly milder in the LDE-PTX + ETP than in the PTX + ETP group. LDE-PTX + ETP combined drug-targeting therapy showed markedly superior anti-cancer properties and reduced toxicity compared to PTX + ETP.State of Sao Paulo Foundation for Research Support (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, BrazilState of Sao Paulo Foundation for Research Support (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, Brazil [06-58917-3]National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, CNPq), Brasilia, Brazil [308238-2006-0]National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, CNPq), Brasilia, BrazilCNPqCNPq [134747/2005-4

Lipid transfers to HDL are predictors of precocious clinical coronary heart disease

Background: High-density-lipoprotein (HDL) has several antiatherogenic properties and, although the concentration of HDL-cholesterol negatively correlates with incidence of coronary artery disease (CAD), this is not sufficient to evaluate the overall HDL protective role. The aim was to investigate whether precocious CAD patients show abnormalities in lipid transfers to HDL, a fundamental step in HDL metabolism and function. Methods: Thirty normocholesterolemic CAD patients aged <50 y and 30 controls paired for sex, age and B.M.I. were studied. Fasting blood samples were collected for the in vitro lipid transfer assay and plasma lipid determination. A donor nanoemulsion labeled with radioactive free-cholesterol. cholesteryl esters, phospholipids and triglycerides was incubated with whole plasma and after chemical precipitation of non-HDL fractions, supernatant was counted for radioactivity in HDL. Results: LDL and HDL-cholesterol and triglycerides were equal in both groups. Transfers of free-cholesterol (3.8 +/- 1.2%vs 7.0 +/- 33%,p<0.0001) and triglycerides (3.7 +/- 1.7%vs 4.9 +/- 1.9%, p = 0.0125) were diminished in CAD patients whereas cholesteryl ester transfer increased (6.5 +/- 1.9%vs 4.8 +/- 1.8%, p = 0.0008); phospholipid transfer was equal (17.8 +/- 3.5% vs19.5 +/- 3.9%). Conclusion: Alterations in the transfer of lipids to HDL may constitute a new marker for precocious CAD and relation of this metabolic alteration with HDL antiatherogenic function should be investigated in future studies. (C) 2011 Published by Elsevier B.V.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, SP, BrazilFundacao do Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, SP, Brazil [06/58917-3]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brasilia, Brazil)CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, Brasilia, Brazil

Lipid Transfer to HDL is Higher in Marathon Runners than in Sedentary Subjects, but is Acutely Inhibited During the Run

Although exercise increases HDL-cholesterol, exercise-induced changes in HDL metabolism have been little explored. Lipid transfer to HDL is essential for HDL's role in reverse cholesterol transport. We investigated the effects of acute exhaustive exercise on lipid transfer to HDL. We compared plasma lipid, apolipoprotein and cytokine levels and in vitro transfer of four lipids from a radioactively labeled lipid donor nanoemulsion to HDL in sedentary individuals (n = 28) and in marathon runners (n = 14) at baseline, immediately after and 72 h after a marathon. While HDL-cholesterol concentrations and apo A1 levels were higher in marathon runners, LDL-cholesterol, apo B and triacylglycerol levels were similar in both groups. Transfers of non-esterified cholesterol [6.8 (5.7-7.2) vs. 5.2 (4.5-6), p = 0.001], phospholipids [21.7 (20.4-22.2) vs. 8.2 (7.7-8.9), p = 0.0001] and triacylglycerol [3.7 (3.1-4) vs. 1.3 (0.8-1.7), p = 0.0001] were higher in marathon runners, but esterified-cholesterol transfer was similar. Immediately after the marathon, LDL- and HDL-cholesterol concentrations and apo A1 levels were unchanged, but apo B and triacylglycerol levels increased. Lipid transfer of non-esterified cholesterol [6.8 (5.7-7.2) vs. 5.8 (4.9-6.6), p = 0.0001], phospholipids [21.7 (20.4-22.2) vs. 19.1 (18.6-19.3), p = 0.0001], esterified-cholesterol [3.2 (2.2-3.8) vs. 2.3 (2-2.9), p = 0.02] and triacylglycerol [3.7 (3.1-4) vs. 2.6 (2.1-2.8), p = 0.0001] to HDL were all reduced immediately after the marathon but returned to baseline 72 h later. Running a marathon increased IL-6 and TNF-alpha levels, but after 72 h these values returned to baseline. Lipid transfer, except esterified-cholesterol transfer, was higher in marathon runners than in sedentary individuals, but the marathon itself acutely inhibited lipid transfer. In light of these novel observations, further study is required to clarify how these metabolic changes can influence HDL composition and anti-atherogenic function.Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP), Sao Paulo, BrazilFundacao de Amparo a Pesquisa de Sao Paulo (FAPESP), Sao Paulo, BrazilConselho Nacional de Desenvolvimanto Cientifico e Tecnologico (CNPq), Brasilia, Brazil [475819/2010-1]Conselho Nacional de Desenvolvimanto Cientifico e Tecnologico (CNPq), Brasilia, Brazi

In Vitro Simultaneous Transfer of Lipids to HDL in Coronary Artery Disease and in Statin Treatment

The exchange of lipids with cells and other lipoproteins is a crucial process in HDL metabolism and for HDL antiatherogenic function. Here, we tested a practical method to quantify the simultaneous transfer to HDL of phospholipids, free-cholesterol, esterified cholesterol and triacylglycerols and to verify the lipid transfer in patients with coronary artery disease (CAD) or undergoing statin treatment. Twenty-eight control subjects without CAD, 27 with CAD and 25 CAD patients under simvastatin treatment were studied. Plasma samples were incubated with a donor nanoemulsion prepared by ultrasonication of the constituent lipids and labeled with radioactive lipids; % lipids transferred to HDL were quantified in the HDL-containing supernatant after chemical precipitation of non-HDL fractions and the nanoemulsion. The assay was precise and reproducible. Increase of temperature (4-37 A degrees C), of incubation period (5 min to 2 h), of HDL-cholesterol concentration (33-244 mg/dL) and of mass of nanoemulsion lipids (0.075-0.3 mg/mu L) resulted in increased lipid transfer from the nanoemulsion to HDL. In contrast, increasing pH (6.5-8.5) and albumin concentration (3.5-7.0 g/dL) did not affect lipid transfer. There was no difference between CAD and control non-CAD with regard to the lipid transfer, but statin treatment reduced the transfer to HDL of all four lipids. The test herein described is a valid and practical tool for exploring an important aspect of HDL metabolism.Fundacao do Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, Brazil[0408048-3]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasilia, Brazi

Previous exercise training increases levels of ppar-alpha in long-term post-myocardial infarction in rats, which is correlated with better inflammatory response

OBJECTIVE: Exercise is a protective factor for cardiovascular morbidity and mortality, with unclear mechanisms. Changing the myocardial metabolism causes harmful consequences for heart function and exercise contributes to metabolic adjustment modulation. Peroxisome proliferator-activated receptors (PPARs) are also myocardium metabolism regulators capable of decreasing the inflammatory response. We hypothesized that PPAR-alpha is involved in the beneficial effects of previous exercise on myocardial infarction (MI) and cardiac function, changing the expression of metabolic and inflammatory response regulators and reducing myocardial apoptosis, which partially explains the better outcome. METHODS AND RESULTS: Exercised rats engaged in swimming sessions for 60 min/day, 5 days/week, for 8 weeks. Both the exercised rats and sedentary rats were randomized to MI surgery and followed for 1 week (EI1 or SI1) or 4 weeks (EI4 or SI4) of healing or to sham groups. Echocardiography was employed to detect left ventricular function and the infarct size. Additionally, the TUNEL technique was used to assess apoptosis and immunohistochemistry was used to quantitatively analyze the PPAR-alpha, TNF-alpha and NF-kappa B antigens in the infarcted and non-infarcted myocardium. MI-related mortality was higher in SI4 than in EI4 (25% vs 12%), without a difference in MI size. SI4 exhibited a lower shortening fraction than EI4 did (24% vs 35%) and a higher apoptosis/area rate (3.97 +/- 0.61 vs 1.90 +/- 1.82) in infarcted areas (both p=0.001). Immunohistochemistry also revealed higher TNF-alpha levels in SI1 than in EI1 (9.59 vs 4.09, p<0.001) in infarcted areas. In non-infarcted areas, EI4 showed higher levels of TNF-alpha and positive correlations between PPAR-alpha and NF-kappa B (r=0.75, p=0.02), in contrast to SI4 (r=0.05, p=0.87). CONCLUSION: Previously exercised animals had better long-term ventricular function post-MI, in addition to lower levels of local inflammatory markers and less myocardial apoptosis, which seemed to be related to the presence of PPAR-alpha.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [06/50489-2]Zerbini FoundationHospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Instituto do Coração (InCor), Laboratório de Patologia Cardíaca, São Paulo/, SP, BrazilUniversidade Federal de São Paulo (UNIFESP), Cardiologia, São Paulo, SP, BrazilUniversidade Federal de São Paulo (UNIFESP), Fisiologia Cardíaca, São Paulo, SP, BrazilUniversidade Nove Julho, Programa de Pós Graduação em Biofotônica Aplicada às Ciências da Saúde, São Paulo/, SP, BrazilUniversidade Federal de São Paulo (UNIFESP), Cardiologia, São Paulo, SP, BrazilUniversidade Federal de São Paulo (UNIFESP), Fisiologia Cardíaca, São Paulo, SP, BrazilFAPESP: 06/50489-2Web of Scienc