Erratum: Circulating Very-Low-Density Lipoprotein Characteristics Resulting from Fatty Liver in an Insulin Resistance Rat Model

The close association between nonalcoholic fatty liver and insulin resistance is now widely recognized. While the former is characterized by excessive intrahepatic triglyceride accumulation, the latter induces overproduction of very-low-density lipoprotein (VLDL) particles. It has not been well elucidated whether these apparently opposite mechanisms impact on VLDL characteristics or not. The aim of the present study was to evaluate the VLDL secretion and features resulting from insulin resistance and fatty liver in rats fed a sucrose-rich diet (SRD, i.e. addition of sucrose to drinking water during 12 weeks). No differences in calorie intake were observed in comparison to controls. Both groups showed similar weight gains throughout the treatment period. However, SRD rats showed an increased proportion of body fat as assessed by X-ray absorptiometry, increased visceral obesity, liver weight and fat accumulation in the liver (p < 0.04). Histological study revealed moderate micro- and macrovesicular steatosis. Fasting insulin, triglyceride and free fatty acid (FFA) levels increased while VLDLs decreased in SRD rats (p < 0.05). The chemical composition of VLDLs of SRD rats showed a higher percentage of triglycerides, and the VLDL triglyceride/protein ratio, an estimator of lipoprotein size, suggests that VLDL particles of SRD rats are larger than those of controls (p < 0.0005). FFA levels correlated with VLDL triglycerides (r = 0.49, p = 0.03) and liver fat content correlated with plasma triglycerides (r = 0.65), VLDL triglycerides (r = 0.55) and triglyceride/protein ratio (r = 0.52, p < 0.02). The VLDL secretion rate assay showed an increase in SRD rats (p < 0.02), confirming an overproduction despite liver fat accumulation. Our findings are consistent with an insulin resistance development model in which hepatic lipid content would constitute an important determinant of a triglyceride-rich, large-particle VLDL secretion; both features would increase its atherogenic potential

Epicardial Adipose Tissue in Cardiovascular Disease

Cardiovascular disease (CVD) is the maincause of morbidity and mortality in industrialized countries, despite the evolution of treatments and revascularization strategies.Obesity, also accompanied by a chronicinflammatory process, is an independent riskfactor for CVD. Abdominal adipose tissue is acomplex, metabolically very active organcapable of producing different adipokines andhormones, responsible for endocrinemetabolic comorbidities. The epicardial adipose tissue (EAT) has not been as extensivelystudied as the abdominal or subcutaneous adipose tissue. However, recent evidence associates it with an increased cardiometabolic riskdue to its apposition with the heart. EAT storestriglycerides to provide energy to the myocardium and is characterized by its greater ability to release and capture free fatty acids. EATstrategic localization allows a singular crosstalk with cardiomyocytes and vascular wallcells. The fact that EAT produces proinflammatory adipokines as well as metalloproteinases and pro-oxidant substances,highlights its possible direct impact on plaquevulnerability and heart failure, being still necessary further studies of EAT behavior inCVD.Fil: Berg, Gabriela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Miksztowicz, Verónica Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Morales, Celina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Barchuk, Magalí. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Rice bran protein hydrolysates reduce arterial stiffening, vascular remodeling and oxidative stress in rats fed a high-carbohydrate and high-fat diet

This study was supported by grants from the Faculty of Medicine, Khon Kaen University, the Agricultural Research Development Agency, the National Research Council of Thailand and the Thailand Research Fund. Ketmanee Senaphan was supported by a scholarship (PHD/0048/2553) from the Royal Golden Jubilee PhD Program, the Thailand Research Fund

Insulin Clearance Is Associated with Hepatic Lipase Activity and Lipid and Adiposity Traits in Mexican Americans

Reduction in insulin clearance plays an important role in the compensatory response to insulin resistance. Given the importance of this trait to the pathogenesis of diabetes, a deeper understanding of its regulation is warranted. Our goal was to identify metabolic and cardiovascular traits that are independently associated with metabolic clearance rate of insulin (MCRI). We conducted a cross-sectional analysis of metabolic and cardiovascular traits in 765 participants from the Mexican-American Coronary Artery Disease (MACAD) project who had undergone blood sampling, oral glucose tolerance test, euglycemic-hyperinsulinemic clamp, dual-energy X-ray absorptiometry, and carotid ultrasound. We assessed correlations of MCRI with traits from seven domains, including anthropometry, biomarkers, cardiovascular, glucose homeostasis, lipase activity, lipid profile, and liver function tests. We found inverse independent correlations between MCRI and hepatic lipase (P = 0.0004), insulin secretion (P = 0.0002), alanine aminotransferase (P = 0.0045), total fat mass (P = 0.014), and diabetes (P = 0.03). MCRI and apolipoprotein A-I exhibited a positive independent correlation (P = 0.035). These results generate a hypothesis that lipid and adiposity associated traits related to liver function may play a role in insulin clearance

Transcriptomic and Proteomic Analysis of the Epicardial Adipose Tissue

The study of epicardial adipose tissue (EAT) has been limited by its accessibility due to its proximity to the heart. Moreover, many common animal models do not have EAT, leaving its functional role underestimated and poorly elucidated. Recent advances in medicine and science have allowed for better studies that provide a more comprehensive understanding of its physiological role. One way to dissect its function is the study of its gene expression. In this chapter, we summarize transcriptomic and proteomic analyses which show that EAT expresses a unique set of genes setting it apart from other adipose tissues in the body. This distinctive set of genes modulates a feedback mechanism that has direct interaction with the myocardium. The EAT shares its blood supply with the coronary arteries and innervation with the cardiac muscle, provides physical protection, and regulates energetic metabolites needed by the myocardium. Transcriptomic and proteomic studies show that it is a local source of adipokines with paracrine influence on the myocardium due to the intimate microcirculation shared by both tissues. These analyses also show that it has a role in the immune and endocrine systems affecting the rest of the body. Furthermore, regulation of EAT gene expression is not monolithic and can be affected by multiple factors such as sex, age, underling disease, medication, etc. Gene expression studies can therefore provide great insight into the function of EAT and its role in health and disease