Prolonged endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) have been linked to apoptosis via several mechanisms, including increased expression of C/EBP ...homologous protein (Chop). Increased long-chain fatty acids, in particular saturated fatty acids, induce ER stress, Chop expression, and apoptosis in liver cells. The first aim of the present study was to determine the role of Chop in lipid-induced hepatocyte cell death and liver injury induced by a methionine-choline-deficient diet. Albumin-bound palmitate increased Chop gene and protein expression in a dose-dependent fashion in H4IIE liver cells. siRNA-mediated silencing of Chop in H4IIE liver cells reduced thapsigargin-mediated cell death by approximately 40% and delayed palmitate-mediated cell death, but only at high concentrations of palmitate (400-500 microM). Similar results were observed in primary hepatocytes isolated from Chop-knockout mice. Indices of liver injury were also not reduced in Chop-knockout mice provided a methionine-choline-deficient diet. To ascertain whether ER stress was linked to palmitate-induced cell death, primary hepatocytes were incubated in the absence or presence of the chemical chaperones taurine-conjugated ursodeoxycholic acid or 4-phenylbutyric acid. The presence of either of these chemical chaperones protected liver cells from palmitate-mediated ER stress and cell death, in part, via inhibition of JNK activation. These data suggest that ER stress is linked to palmitate-mediated cell death via mechanisms that include JNK activation.
To review the literature systematically and perform meta-analyses to address these questions: 1) Is there evidence that self-measured blood pressure (BP) without other augmentation is superior to ...office-based measurement of BP for achieving better BP control or for preventing adverse clinical outcomes that are related to elevated BP? 2) What is the optimal target for BP lowering during antihypertensive therapy in adults? 3) In adults with hypertension, how do various antihypertensive drug classes differ in their benefits and harms compared with each other as first-line therapy?
Electronic literature searches were performed by Doctor Evidence, a global medical evidence software and services company, across PubMed and EMBASE from 1966 to 2015 using key words and relevant subject headings for randomized controlled trials that met eligibility criteria defined for each question. We performed analyses using traditional frequentist statistical and Bayesian approaches, including random-effects Bayesian network meta-analyses.
Our results suggest that: 1) There is a modest but significant improvement in systolic BP in randomized controlled trials of self-measured BP versus usual care at 6 but not 12 months, and for selected patients and their providers self-measured BP may be a helpful adjunct to routine office care. 2) systolic BP lowering to a target of <130 mm Hg may reduce the risk of several important outcomes including risk of myocardial infarction, stroke, heart failure, and major cardiovascular events. No class of medications (i.e., angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, calcium channel blockers, or beta blockers) was significantly better than thiazides and thiazide-like diuretics as a first-line therapy for any outcome.
Abstract Background In cell systems, saturated fatty acids, compared to unsaturated fatty acids, induce a greater degree of ER stress and inflammatory signaling in a number of cell types, including ...hepatocytes and adipocytes. The aim of the present study was to determine the effects of infusions of lard oil (enriched in saturated fatty acids) and soybean oil (enriched in unsaturated fatty acids) on liver and adipose tissue ER stress and inflammatory signaling in vivo. Methods Lipid emulsions containing glycerol, phosphatidylcholine, antibiotics (Control, n = 7) and either soybean oil (Soybean, n = 7) or lard oil (Lard, n = 7) were infused intravenously into rats over a 4 h period. Results Plasma free fatty acid levels were 0.5 ± 0.1 mmol/L (mean ± SD) in Control and were increased to 1.0 ± 0.3 mmol/L and 1.1 ± 0.3 mmol/L in Soybean and Lard, respectively. Glucose and insulin levels were not different among groups. Markers of endoplasmic reticulum (ER) stress and activation of inflammatory pathway signaling were increased in liver and adipose tissue from Soybean and Lard compared to Control, but were increased to a greater extent in Lard compared to Soybean. Conclusions These data suggest that elevated plasma free fatty acids can induce hepatic and adipose tissue ER stress and inflammation in vivo. In addition, saturated fatty acids appear to be more cytotoxic than unsaturated fatty acids in vivo.
The incidence of obesity is now at epidemic proportions and has resulted in the emergence of nonalcoholic fatty liver disease (NAFLD) as a common metabolic disorder that can lead to liver injury and ...cirrhosis. Excess sucrose and long-chain saturated fatty acids in the diet may play a role in the development and progression of NAFLD. One factor linking sucrose and saturated fatty acids to liver damage is dysfunction of the endoplasmic reticulum (ER). Although there is currently no proven, effective therapy for NAFLD, the amino sulfonic acid taurine is protective against various metabolic disturbances, including alcohol-induced liver damage. The present study was undertaken to evaluate the therapeutic potential of taurine to serve as a preventative treatment for diet-induced NAFLD. We report that taurine significantly mitigated palmitate-mediated caspase-3 activity, cell death, ER stress, and oxidative stress in H4IIE liver cells and primary hepatocytes. In rats fed a high-sucrose diet, dietary taurine supplementation significantly reduced hepatic lipid accumulation, liver injury, inflammation, plasma triglycerides, and insulin levels. The high-sucrose diet resulted in an induction of multiple components of the unfolded protein response in the liver consistent with ER stress, which was ameliorated by taurine supplementation. Treatment of mice with the ER stress-inducing agent tunicamycin resulted in liver injury, unfolded protein response induction, and hepatic lipid accumulation that was significantly ameliorated by dietary supplementation with taurine. Our results indicate that dietary supplementation with taurine offers significant potential as a preventative treatment for NAFLD.
The refinement of tightly regulated prokaryotic expression systems that permit functional expression of toxic recombinant proteins is a continually evolving process. Unfortunately, the current best ...promoter options are either tightly repressed and produce little protein, or produce substantial protein but lack the necessary repression to avoid mutations stimulated by leaky expression in the absence of inducer. In this report, we present three novel prokaryotic expression constructs that are tightly regulated by L-rhamnose and D-glucose. These expression vectors utilize the Escherichia coli rhaT promoter and corresponding regulatory genes to provide titratable, high-level protein yield without compromising clone integrity. Together, these components may enable the stable cloning and functional expression of otherwise toxic proteins.
Sphingosine-1-phosphate (S1P) is a pleiotropic lysolipid that has recently been implicated in the regulation of tissue fibrosis. However, the fibrogenic potential of S1P in the eye has not previously ...been investigated. In the current study, we evaluated cells from the anterior and posterior segments of the eye for the presence of S1P and their potential ability to produce and respond to S1P. In addition, we investigated the regulatory role of S1P as a mediator of proliferation, cellular transformation and pro-fibrotic protein expression in human retinal pigmented epithelial cells. Expression of S1P receptors and sphingosine kinases (the enzymes that produce S1P) was examined using RT-PCR, and intracellular localization of S1P was examined using immunoblotting, immunohistochemistry and ELISA in primary human retinal pigmented epithelial (RPE) cells, primary human conjunctival fibroblasts (ConF), and primary human corneal fibroblasts (CF). RPE cell proliferation was determined using an MTT-based cell proliferation assay, and RPE myofibroblast transformation, collagen type I production and profibrotic protein expression were assessed using immunofluorescence, ELISA and immunoblot. S1P
1–3, 5 receptors and sphingosine kinases 1 and 2 were expressed and intracellular pools of S1P were detected in RPE cells, ConF and CF. S1P stimulated RPE cell proliferation in a dose- and time-dependent manner. S1P induced myofibroblast transformation of RPE cells, as indicated by increased α-smooth muscle actin (α-SMA) expression and its incorporation into prominent stress fibers, and promoted collagen type I production. S1P stimulated the expression of plasminogen activator inhibitor-1 (PAI-1) and heat shock protein 47 (HSP47), two proteins that are linked to increased tissue fibrosis. Combined, these data demonstrate that RPE cells, ConF and CF from the human eye not only have the molecular ability to produce and respond to S1P, but also contain S1P. Furthermore, S1P promotes proliferation, myofibroblast transformation, collagen production and pro-fibrotic protein expression by human RPE cells. These data suggest that S1P is a previously unrecognized mediator of profibrotic cellular function and signaling in the eye.
Pericardiocentesis is useful in the diagnosis and treatment of pericardial effusive disease. To date, a number of methods have been developed to reduce complications and increase the success rate of ...the procedure. The aim of the present study was to evaluate the efficacy and the safety of echocardiography-guided pericardiocentesis under continuous echocardiographic monitoring in the management of pericardial effusion. We prospectively performed 161 pericardiocentesis procedures in 141 patients admitted from 1993 to 2015 in 3 centers. This procedure was performed for tamponade or large pericardial effusion in 157 cases and for diagnosis in 4 cases. A percutaneous puncture was performed where the largest amount of fluid was detected. To perform a real-time echo-guided procedure, a multi-angle bracket was mounted on the echocardiographic probe to support the needle and enable its continuous visualization during the puncture. The procedure was successful in 160 of 161 cases (99%). Two major complications occurred (1.2%): 1 mediastinal hematoma that required surgical drainage in a patient on anticoagulant therapy and 1 pleuropericardial shunt requiring thoracentesis. Seven minor complications occurred (4.3%): 1 pleuropericardial shunt, 1 case of transient AV type III block, 3 vasovagal reactions (1 with syncope), and 2 cases of acute pulmonary edema managed with medical therapy. No punctures of any cardiac chamber occurred, and emergency surgical drainage was not required in any case. In conclusion, echocardiography-guided pericardiocentesis under continuous visualization is effective, safe, and easy to perform, even in hospitals with low volumes of procedures with or without cardiac surgery.
Summary
The delivery of DNA to mammalian cells is of critical importance to the development of genetic vaccines, gene replacement therapies and gene silencing. For these applications, targeting, ...effective DNA transfer and vector safety are the major roadblocks in furthering development. In this report, we present a novel DNA delivery vehicle that makes use of protoplasted, achromosomal bacterial minicells. Transfer of plasmid DNA as measured by green fluorescent protein expression was found to occur in as high as 25% of cultured Cos‐7 cells when a novel chimeric protein containing the D2–D5 region of invasin was expressed and displayed on the surface of protoplasted minicells. Based on endoplasmic reticulum stress and other responses, protoplasted minicells were non‐toxic to recipient eukaryotic cells as a consequence of the transfection process. Taken together, these results suggest that bacterial minicells may represent a novel and promising gene delivery vehicle.
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