High stretch induces endothelial dysfunction accompanied by oxidative stress and actin remodeling in human saphenous vein endothelial cells

The rate of the remodeling of the arterialized saphenous vein conduit limits the outcomes of coronary artery bypass graft surgery (CABG), which may be influenced by endothelial dysfunction. We tested the hypothesis that high stretch (HS) induces human saphenous vein endothelial cell (hSVEC) dysfunction and examined candidate underlying mechanisms. Our results showed that in vitro HS reduces NO bioavailability, increases inflammatory adhesion molecule expression (E-selectin and VCAM1) and THP-1 cell adhesion. HS decreases F-actin in hSVECs, but not in human arterial endothelial cells, and is accompanied by G-actin and cofilin’s nuclear shuttling and increased reactive oxidative species (ROS). Pre-treatment with the broad-acting antioxidant N-acetylcysteine (NAC) supported this observation and diminished stretch-induced actin remodeling and inflammatory adhesive molecule expression. Altogether, we provide evidence that increased oxidative stress and actin cytoskeleton remodeling play a role in HS-induced saphenous vein endothelial cell dysfunction, which may contribute to predisposing saphenous vein graft to failure

Dietary sodium intake and overweight and obesity in children and adults: a protocol for a systematic review and meta-analysis.

BACKGROUND: Overweight and obesity in children and adults is a major public health concern. Emerging evidence suggests dietary sodium intake may be associated with obesity. This systematic review and meta-analysis will aim to (i) assess the relation between dietary sodium intake and measures of adiposity in children and adults and (ii) examine the relation between sodium intake and sugar-sweetened beverage (SSB) consumption, which is a known risk factor for obesity. METHODS/DESIGN: An electronic search will be conducted using Medline Complete, CINAHL, Scopus, Embase and Cochrane central register of controlled trials (CENTRAL). The search strategy will identify published peer-reviewed articles that report on dietary sodium and either a marker of adiposity or SSB consumption. Only human studies (ages >1 year) in English will be included, and no limits will be placed on publication date. No restrictions will be placed on the method of sodium intake assessment. Cross-sectional, prospective studies, and randomised controlled trials with a duration of ≥ 3 months will be included. Studies with participants with renal disease, cancer, type 1 diabetes or heart failure or who are pregnant will be excluded. To assess the quality of studies, the Cochrane's Collaboration tool for assessing risk of bias in randomised trials will be used for randomised controlled trials (RCTs), and the modified Newcastle-Ottawa Scale will be used for cross-sectional and prospective studies. Meta-analysis will be used to assess the relation of sodium intake with two primary outcomes: (i) BMI and body weight in adults and BMI z-score in children and (ii) weight category (i.e. healthy weight vs. overweight/obese). For any outcomes in which meta-analysis is not possible, we will present data as a systematic review. Findings will be grouped and reported separately for children and adolescents (ages 1-17 years) and adults (ages >18 years). DISCUSSION: This review and meta-analysis will provide insight into the relation between dietary sodium intake and overweight and obesity. This information can be used to inform public health policies which target population sodium consumption. SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42015016440.CG is supported by a National Heart Foundation of Australia Postdoctoral Fellowship (Award ID: 100155)

Leucine supplementation improves adiponectin and total cholesterol concentrations despite the lack of changes in adiposity or glucose homeostasis in rats previously exposed to a high-fat diet

<p>Abstract</p> <p>Background</p> <p>Studies suggest that leucine supplementation (LS) has a therapeutic potential to prevent obesity and to promote glucose homeostasis. Furthermore, regular physical exercise is a widely accepted strategy for body weight maintenance and also for the prevention of obesity. The aim of this study was to determine the effect of chronic LS alone or combined with endurance training (ET) as potential approaches for reversing the insulin resistance and obesity induced by a high-fat diet (HFD) in rats.</p> <p>Methods</p> <p>Forty-seven rats were randomly divided into two groups. Animals were fed a control diet-low fat (<it>n = </it>10) or HFD (<it>n = </it>37). After 15 weeks on HFD, all rats received the control diet-low fat and were randomly divided according to treatment: reference (REF), LS, ET, and LS+ET (<it>n = </it>7-8 rats per group). After 6 weeks of treatment, the animals were sacrificed and body composition, fat cell volume, and serum concentrations of total cholesterol, HDL-cholesterol, triacylglycerol, glucose, adiponectin, leptin and tumor necrosis factor-alpha (TNF-α) were analyzed.</p> <p>Results</p> <p>At the end of the sixth week of treatment, there was no significant difference in body weight between the REF, LS, ET and LS+ET groups. However, ET increased lean body mass in rats (<it>P </it>= 0.019). In addition, ET was more effective than LS in reducing adiposity (<it>P </it>= 0.019), serum insulin (<it>P </it>= 0.022) and TNF-α (<it>P </it>= 0.044). Conversely, LS increased serum adiponectin (<it>P </it>= 0.021) levels and reduced serum total cholesterol concentration (<it>P </it>= 0.042).</p> <p>Conclusions</p> <p>The results showed that LS had no beneficial effects on insulin sensitivity or adiposity in previously obese rats. On the other hand, LS was effective in increasing adiponectin levels and in reducing total cholesterol concentration.</p

Obesity, inflammation, and insulin resistance

White adipose tissue (WAT) is considered an endocrine organ. When present in excess, WAT can influence metabolism via biologically active molecules. Following unregulated production of such molecules, adipose tissue dysfunction results, contributing to complications associated with obesity. Previous studies have implicated pro- and anti-inflammatory substances in the regulation of inflammatory response and in the development of insulin resistance. In obese individuals, pro-inflammatory molecules produced by adipose tissue contribute to the development of insulin resistance and increased risk of cardiovascular disease. On the other hand, the molecules with anti-inflammatory action, that have been associated with the improvement of insulin sensitivity, have your decreased production. Imbalance of these substances contributes significantly to metabolic disorders found in obese individuals. The current review aims to provide updated information regarding the activity of biomolecules produced by WAT