O-Glycosylation Regulates Ubiquitination and Degradation of the Anti-Inflammatory Protein A20 to Accelerate Atherosclerosis in Diabetic ApoE-Null Mice

Background: Accelerated atherosclerosis is the leading cause of morbidity and mortality in diabetic patients. Hyperglycemia is a recognized independent risk factor for heightened atherogenesis in diabetes mellitus (DM). However, our understanding of the mechanisms underlying glucose damage to the vasculature remains incomplete. Methodology/Principal Findings: High glucose and hyperglycemia reduced upregulation of the NF-κB inhibitory and atheroprotective protein A20 in human coronary endothelial (EC) and smooth muscle cell (SMC) cultures challenged with Tumor Necrosis Factor alpha (TNF), aortae of diabetic mice following Lipopolysaccharide (LPS) injection used as an inflammatory insult and in failed vein-grafts of diabetic patients. Decreased vascular expression of A20 did not relate to defective transcription, as A20 mRNA levels were similar or even higher in EC/SMC cultured in high glucose, in vessels of diabetic C57BL/6 and FBV/N mice, and in failed vein grafts of diabetic patients, when compared to controls. Rather, decreased A20 expression correlated with post-translational O-Glucosamine-N-Acetylation (O-GlcNAcylation) and ubiquitination of A20, targeting it for proteasomal degradation. Restoring A20 levels by inhibiting O-GlcNAcylation, blocking proteasome activity, or overexpressing A20, blocked upregulation of the receptor for advanced glycation end-products (RAGE) and phosphorylation of PKCβII, two prime atherogenic signals triggered by high glucose in EC/SMC. A20 gene transfer to the aortic arch of diabetic ApoE null mice that develop accelerated atherosclerosis, attenuated vascular expression of RAGE and phospho-PKCβII, significantly reducing atherosclerosis. Conclusions: High glucose/hyperglycemia regulate vascular A20 expression via O-GlcNAcylation-dependent ubiquitination and proteasomal degradation. This could be key to the pathogenesis of accelerated atherosclerosis in diabetes

Interventional Echocardiography: Field of Advanced Imaging to Support Structural Heart Interventions

Multimodality imaging, particularly echocardiography, is paramount in planning and guiding structural heart disease interventions. Transesophageal echocardiography remains unique in its ability to provide real-time 2D and 3D imaging of valvular heart disease and anatomic cardiac defects, which directly impacts the strategy and outcome of these procedures. This review summarizes the role of transesophageal echocardiography in patients undergoing the most common structural heart disease interventions. </jats:p

Lyme Carditis Presenting as Sinus Node Dysfunction and Accelerated Junctional Rhythm

Lyme disease can have cardiac involvement and can subsequently present with various types of atrio ventricular (AV) block. Sinus node dysfunction (SND) and accelerated junctional rhythm are highlighted in this case as an uncommon presentation for Lyme Carditis. This case highlights the importance of having a high index of suspicion for cardiac involvement with Lyme disease when atypical arrhythmias are present.</jats:p

The Influence Of Customer Perceived Ethicality On Customer Loyalty And Trust

The concern for business ethics is of no doubt under huge attention today. The ethical reputation in banking sector is believed to play a crucial role and might build customer trust in financial partner as well as strengthen identification and commitment for the company. Is there a clear answer how ‘ethical’ is perceived by customers? Do customers trust ethical companies more? Do customers tend to be more loyal to ethical companies? The goal of the paper is to analyze factors which constitute company ethicality for customers and to examine the influence of perceived ethicality on customer loyalty and trust with the bank

A hybrid partial and general equilibrium modeling approach to assess the hydro-economic impacts of large dams: The case of the Grand Ethiopian Renaissance Dam in the Eastern Nile River basin

A novel integrated hydro-economic modeling framework that links a bottom-up partial equilibrium (engineering) model with a top-down (economic) general equilibrium model is developed for assessing the regional economic impacts of water resources management and infrastructure development decisions in a transboundary river basin. The engineering model is employed first to solve the water allocation problem for a river system in a partial equilibrium setting. The resulting system-wide changes in optimal water allocation are subsequently fed into the general equilibrium model to provide an economy-wide perspective. This integrated hydro-economic modeling framework is illustrated using the Eastern Nile River basin as a case study. The engineering-based stochastic dual dynamic programming (SDDP) model of the Eastern Nile basin is coupled with the computable general equilibrium (CGE) model GTAP-W to assess the economy-wide impacts of the Grand Ethiopian Renaissance Dam (GERD) on the Eastern Nile economies.Accepted Author ManuscriptWater Resource

Lower A20 protein levels contrast with increased mRNA levels in failed vein grafts of diabetic patients.

<p>(A) A20 protein expression and (B) mRNA levels (real-time PCR, lower panel) in failed vein grafts recovered from non-diabetic (ND) and patients with type I and type II DM (t1 and t2 DM) show lower A20 protein levels in failed vein grafts of diabetic patients as compared to non-diabetic patients, despite significantly higher A20 mRNA levels in these samples. Expression of GAPDH was checked as a loading control and to quantify relative A20 expression by densitometry. A20/GAPDH ratios are listed below the WB. Data shown are representative of 4 patients in each group. Samples were all run on the same gel but are shown as separate because they were not loaded contiguously. (B) A20 mRNA levels of the same failed vein grafts shown in 4A demonstrate increased A20 mRNA levels in failed vein grafts from diabetic vs. non-diabetic patients. 18S ribosomal RNA was used to normalize the data. Data is expressed as fold increase of A20 mRNA using the A20 mRNA level detected in the failed vein graft of the non-diabetic patient as a baseline value. (C) A20 mRNA levels analyzed by real time PCR from failed vein grafts of diabetic (DM) and non-diabetic (ND) patients show significantly higher A20 mRNA in failed vein grafts of diabetic versus non-diabetic patients; **p = 0.0016. 18S ribosomal RNA was used to normalize the data. Natural log transformed data (ln) are presented as mean±SEM of 6 failed vein grafts per group. The 6 failed vein grafts from diabetic patients included 2 type I and 4 type II DM patients. Data is expressed as fold increase of A20 mRNA using the A20 mRNA level detected in the failed vein graft of the non-diabetic patient shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0014240#pone-0014240-g001" target="_blank">Figure 1A</a>, as a baseline value.</p

Restoring A20 levels reverts glucose-mediated upregulation of RAGE and phosphorylation of PKCβII.

<p>(A) WB analysis for RAGE and A20 expression in SMC cultured in 5 or 30 mM D-Glu for 24 h and treated with TNF in the presence or absence of 20 mM of Azaserine (prior to TNF) or 10 mM of MG132 (following TNF). Corrected RAGE fold-inductions are listed below the WB. The RAGE protein is detected as a doublet as a result of pre and post-N-glycosylated form of the protein. Both bands were used for densitometry evaluation. (B) WB analysis of phospho-PKCβII (pPKCβII) and total (c) PKCβII in NT SMC, and in SMC transduced with rAd.A20 or rAd.βgal, and treated with PMA or challenged with 30 mM D-Glu for 1 h. Data shown in A and B are representative of 3 independent experiments. NT = non-transduced cells. GAPDH was used as loading control to quantify the relative expression of RAGE and pPKCβII by densitometry.</p

Expression of A20 in the ascending aorta and aortic arch of diabetic ApoE-null mice prevents the development of atherosclerotic lesions by inhibiting PKCβII phosphorylation and blunting the induction of RAGE.

<p>(A) Transgene expression was confirmed by X-gal staining in rAd.βgal-transduced vessels 5 days following transgene delivery (n = 3 mice/group) and demonstrate the expression of the transgene in medial SMC (M) as well as the adventitia at the level of the aortic root, albeit not in all cells. Image amplification 100× and 400×. (B) A20 expression was verified by real time RT-PCR in two rAd.A20-transduced vessels, using human A20 specific primers that do not recognize mouse A20. Our data indicate significant expression of human A20 in aortic roots of rAd.A20 but not saline treated mice. Results are shown as average± SE. (C) H&E stained aortic root sections at the level of the first coronary from 20 week-old diabetic ApoE-null mice treated with saline, rAd.A20 or rAd.βgal. Images are shown at 100× and 400× as indicated by the scale bar. The asterisk indicates the level of the first coronary branch, Arrows define the intima (I) and the media (M). ApoE-competent, non-diabetic C57BL/6 and non-diabetic ApoE-null mice were used as controls. Blood glucose and cholesterol levels (cholest) are listed below the sections. *P<0.05 compared to saline, ** P<0.01 compared to rAd. βGal. Data shown are representative of 4 to 6 mice per group. I/M ratios were calculated after analysis of 10 serial sections per vessel. (D) phospho-(p)PKCβII (5 days) and RAGE (14 days) immunostaining in aortic arches 5 and 14 days after transgene delivery. Data shown in C are representative of all sections analyzed (n = 3 mice per group, 2–3 sections analyzed per vessel). Image amplification 200×.</p