Left ventricular geometry characteristics and clinical outcomes in hemodialysis patients with heart failure with preserved ejection fraction.

BACKGROUND: The relationships among left heart remodeling, cardiac function, and cardiovascular events (CEs) in patients with heart failure (HF) with preserved ejection fraction (HFpEF) undergoing maintenance hemodialysis (MHD) remain unclear. We evaluated the echocardiographic characteristics and clinical outcomes of such patients with diverse left ventricular geometric (LVG) configurations. METHODS: Overall, 210 patients with HFpEF undergoing MHD (cases) and 60 healthy controls were enrolled. Cases were divided into four subgroups based on LVG and were followed up for three years. The primary outcomes were the first CEs and all-cause mortality. RESULTS: Left ventricular ejection fraction (LVEF) and right ventricular systolic function did significantly differ between cases and controls, whereas echocardiographic parameters of cardiac structure, diastolic function, and left ventricular global longitudinal strain (LVGLS) differed significantly. The proportion of cases with left ventricular hypertrophy (LVH) was 67.1%. In addition, 2.38%, 21.90%, 12.86%, and 62.86% of cases presented with normal geometry (NG), concentric remodeling (CR), eccentric hypertrophy (EH), and concentric hypertrophy (CH), respectively. The left atrial diameter (LAD) was the largest and cardiac output index was the lowest in the EH subgroup. The score of Acute Dialysis Quality Initiative Workgroup (ADQI) HF class was worse in the EH subgroup than in other subgroups at baseline. The proportions of cases free of adverse CEs in the EH subgroup at 12, 24, and 36 months were 40.2%, 14.8%, and 0%, respectively, and the survival rates were 85.2%, 29.6%, 3.7%, respectively, which were significantly lower than those in other subgroups. Multivariate Cox regression revealed that age, TNI (Troponin I), EH, left ventricular mass index (LVMI), age and EH configuration were independent risk factors for adverse CEs and all-cause mortality in the cases. CONCLUSION: Most patients with HFpEF receiving MHD have LVH and diastolic dysfunction. Among the four LVGs, patients with HFpEF undergoing MHD who exhibited EH had the highest risk of adverse CEs and all-cause mortality.

Stimulation of Intestinal Cl- Secretion Through CFTR by Caffeine Intake in Salt-Sensitive Hypertensive Rats.

BACKGROUND/AIMS: High salt consumption is a major risk factor for hypertension, and sodium homeostasis is regulated by both intestinal sodium absorption and urinary sodium excretion. Chronic caffeine intake has been reported to attenuate salt-sensitive hypertension by promoting urinary sodium excretion; however, its exact role in intestinal sodium absorption remains unknown. Here, we investigated whether and how chronic caffeine consumption antagonizes salt-sensitive hypertension by inhibiting intestinal sodium absorption. METHODS: Dahl salt-sensitive rats were fed 8% NaCl chow and 0.1% caffeine in their drinking water for 15 days. The blood pressure and fecal sodium content were measured. The effect of caffeine on the movement of Cl- in enterocyte cells was determined with the Ussing chamber assay. RESULTS: Rats that were treated with caffeine displayed significantly lower mean blood pressure and higher fecal sodium content than the controls. Consistent with these findings, caffeine intake decreased fluid absorption by the intestine in the fluid perfusion experiment. Further, the results from the Ussing chamber assay indicated that caffeine promoted Cl- secretion through enterocyte apical cystic fibrosis transmembrane conductance regulator (CFTR), and thus inhibited sodium absorption. Moreover, depletion of cAMP or inhibition of CFTR completely abolished the effect of caffeine on Cl- secretion. CONCLUSION: The results indicate that chronic caffeine consumption reduces sodium absorption by promoting CFTR-mediated Cl- secretion in the intestine, which contributes to the anti-hypertensive effect of caffeine in salt-sensitive rats.

Enhancement of Neural Salty Preference in Obesity.

BACKGROUND/AIMS: Obesity and high salt intake are major risk factors for hypertension and cardiometabolic diseases. Obese individuals often consume more dietary salt. We aim to examine the neurophysiologic effects underlying obesity-related high salt intake. METHODS: A multi-center, random-order, double-blind taste study, SATIETY-1, was conducted in the communities of four cities in China; and an interventional study was also performed in the local community of Chongqing, using brain positron emission tomography/computed tomography (PET/CT) scanning. RESULTS: We showed that overweight/obese individuals were prone to consume a higher daily salt intake (2.0 g/day higher compared with normal weight individuals after multivariable adjustment, 95% CI, 1.2-2.8 g/day, P < 0.001), furthermore they exhibited reduced salt sensitivity and a higher salt preference. The altered salty taste and salty preference in the overweight/obese individuals was related to increased activity in brain regions that included the orbitofrontal cortex (OFC, r = 0.44, P= 0.01), insula (r = 0.38, P= 0.03), and parahippocampus (r = 0.37, P= 0.04). CONCLUSION: Increased salt intake among overweight/obese individuals is associated with altered salt sensitivity and preference that related to the abnormal activity of gustatory cortex. This study provides insights for reducing salt intake by modifying neural processing of salty preference in obesity.

ABCA1 rs4149313 polymorphism and susceptibility to coronary heart disease: a meta-analysis.

Many existing studies have demonstrated that common polymorphisms in the ABCA1 gene may play important roles in the development and progression of coronary heart disease (CHD), but individually published results are inconclusive. This meta-analysis aimed to derive a more precise estimation of the relationship between the ABCA1 rs4149313 polymorphism and CHD risk. We searched the CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and CBM databases from inception through 1 September 2013. Meta-analysis was performed using the STATA 12.0 software. Odds ratios (OR) and their 95% confidence intervals (CI) were estimated. Eleven case-control studies were included with a total of 5416 CHD patients and 20,897 healthy controls. Our meta-analysis results revealed that the ABCA1 rs4149313 polymorphism may be associated with an increased risk of CHD. Subgroup analysis by ethnicity suggested that there were significant associations between the ABCA1 rs4149313 polymorphism and an increased risk of CHD in Asian populations, but not in Caucasian populations (all P > 0.05). Meta-regression analyses showed that ethnicity may be a main source of heterogeneity. The present meta-analysis suggests that the ABCA1 rs4149313 polymorphism may contribute to the risk of CHD, especially in Asian populations.

Inflammatory factor-specific sumoylation regulates NF-κB signalling in glomerular cells from diabetic rats.

OBJECTIVE: The activation of nuclear factor (NF)-κB by cytokines under hyperglycaemic conditions is a potential mechanism for complications in diabetes. We investigated whether small ubiquitin-like modifier 4 (SUMO4) regulates renal NF-κB signalling in diabetic rats. METHODS: Histological changes in kidney were analysed in diabetic GK rats. The expressions of tumour necrosis factor (TNF)-α, NF-κB (p65), IκBα and SUMO4 in renal tissues were examined by immunohistochemistry and Western blotting. Primary cultured glomerular endothelial cells from rats were stimulated by TNF-α or interleukin (IL)-2. RESULTS: The renal expression of TNF-α, NF-κB (p65), IκBα and SUMO4 was significantly higher in diabetic GK rats than in control rats. In control rats, no nuclear translocation was observed for IκBα or NF-κB (p65). However, in diabetic GK rats, translocation of NF-κB (p65) and IκBα into the nucleus was observed, and the expression of SUMO4 and IκBα was up-regulated in the glomerular endothelial cells. SUMO4 was localised in both the cytoplasm and nucleus, while IκBα was predominantly located in the nucleus after stimulation with TNF-α. In contrast, SUMO4 was localised in the nucleus, and increased cytoplasm SUMO4 localisation was found after stimulation with IL-2. CONCLUSIONS: SUMO4 plays a role in regulating NF-κB signalling in glomerular cells. Cytokines have a unique effect in regulating the sumoylation of NF-κB.

TRPV1-mediated UCP2 upregulation ameliorates hyperglycemia-induced endothelial dysfunction.

BACKGROUND: Diabetic cardiovascular complications are characterised by oxidative stress-induced endothelial dysfunction. Uncoupling protein 2 (UCP2) is a regulator of mitochondrial reactive oxygen species (ROS) generation and can antagonise oxidative stress, but approaches that enhance the activity of UCP2 to inhibit ROS are scarce. Our previous studies show that activation of transient receptor potential vanilloid 1 (TRPV1) by capsaicin can prevent cardiometabolic disorders. In this study, we conducted experiments in vitro and in vivo to investigate the effect of capsaicin treatment on endothelial UCP2 and oxidative stress. We hypothesised that TRPV1 activation by capsaicin attenuates hyperglycemia-induced endothelial dysfunction through a UCP2-mediated antioxidant effect. METHODS: TRPV1(-/-), UCP2(-/-) and db/db mice, as well as matched wild type (WT) control mice, were included in this study. Some mice were subjected to dietary capsaicin for 14 weeks. Arteries isolated from mice and endothelial cells were cultured. Endothelial function was examined, and immunohistological and molecular analyses were performed. RESULTS: Under high-glucose conditions, TRPV1 expression and protein kinase A (PKA) phosphorylation were found to be decreased in the cultured endothelial cells, and the effects of high-glucose on these molecules were reversed by the administration of capsaicin. Furthermore, high-glucose exposure increased ROS production and reduced nitric oxide (NO) levels both in endothelial cells and in arteries that were evaluated respectively by dihydroethidium (DHE) and DAF-2 DA fluorescence. Capsaicin administration decreased the production of ROS, restored high-glucose-induced endothelial dysfunction through the activation of TRPV1 and acted in a UCP2-dependent manner in vivo. Administration of dietary capsaicin for 14 weeks increased the levels of PKA phosphorylation and UCP2 expression, ameliorated the vascular oxidative stress and increased NO levels observed in diabetic mice. Prolonged dietary administration of capsaicin promoted endothelium-dependent relaxation in diabetic mice. However, the beneficial effect of capsaicin on vasorelaxation was absent in the aortas of UCP2(-/-) mice exposed to high-glucose levels. CONCLUSION: TRPV1 activation by capsaicin might protect against hyperglycemia-induced endothelial dysfunction through a mechanism involving the PKA/UCP2 pathway.

Honokiol inhibits tumor necrosis factor-α-stimulated rat aortic smooth muscle cell proliferation via caspase- and mitochondrial-dependent apoptosis.

This study aims to investigate the effects of honokiol on proliferation, cell cycle, and apoptosis in tumor necrosis factor (TNF)-α-induced rat aortic smooth muscle cells (RASMCs). We found that honokiol treatment showed potent inhibitory effects on TNF-α-induced RASMC proliferation, which were associated with G0/G1 cell cycle arrest and downregulation of cell cycle-related proteins, including cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2 and CDK4. Furthermore, honokiol treatment led to the release of cytochrome c into cytosol and a loss of mitochondrial membrane potential (ΔΨm), as well as a decrease in the expression of Bcl-2 and an increase in the expression of Bax. Treatment with honokiol also reduced TNF-α-induced phosphorylation of p38, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase. Taken together, our results suggest that honokiol suppresses TNF-α-stimulated RASMC proliferation via caspase- and mitochondria-dependent apoptosis and highlight the therapeutic potential of honokiol in the prevention of cardiovascular diseases.