Increasing Glucose 6-Phosphate Dehydrogenase Activity Restores Redox Balance in Vascular Endothelial Cells Exposed to High Glucose

Previous studies have shown that high glucose increases reactive oxygen species (ROS) in endothelial cells that contributes to vascular dysfunction and atherosclerosis. Accumulation of ROS is due to dysregulated redox balance between ROS-producing systems and antioxidant systems. Previous research from our laboratory has shown that high glucose decreases the principal cellular reductant, NADPH by impairing the activity of glucose 6-phosphate dehydrogenase (G6PD). We and others also have shown that the high glucose-induced decrease in G6PD activity is mediated, at least in part, by cAMP-dependent protein kinase A (PKA). As both the major antioxidant enzymes and NADPH oxidase, a major source of ROS, use NADPH as substrate, we explored whether G6PD activity was a critical mediator of redox balance. We found that overexpression of G6PD by pAD-G6PD infection restored redox balance. Moreover inhibition of PKA decreased ROS accumulation and increased redox enzymes, while not altering the protein expression level of redox enzymes. Interestingly, high glucose stimulated an increase in NADPH oxidase (NOX) and colocalization of G6PD with NOX, which was inhibited by the PKA inhibitor. Lastly, inhibition of PKA ameliorated high glucose mediated increase in cell death and inhibition of cell growth. These studies illustrate that increasing G6PD activity restores redox balance in endothelial cells exposed to high glucose, which is a potentially important therapeutic target to protect ECs from the deleterious effects of high glucose

Bone Morphogenetic Protein‐2 Decreases MicroRNA‐30b and MicroRNA‐30c to Promote Vascular Smooth Muscle Cell Calcification

Background: Vascular calcification resembles bone formation and involves vascular smooth muscle cell (SMC) transition to an osteoblast‐like phenotype to express Runx2, a master osteoblast transcription factor. One possible mechanism by which Runx2 protein expression is induced is downregulation of inhibitory microRNAs (miR). Methods and Results: Human coronary artery SMCs (CASMCs) treated with bone morphogenetic protein‐2 (BMP‐2; 100 ng/mL) demonstrated a 1.7‐fold (P<0.02) increase in Runx2 protein expression at 24 hours. A miR microarray and target prediction database analysis independently identified miR‐30b and miR‐30c (miR‐30b‐c) as miRs that regulate Runx2 expression. Real‐time–polymerase chain reaction confirmed that BMP‐2 decreased miR‐30b and miR‐30c expression. A luciferase reporter assay verified that both miR‐30b and miR‐30c bind to the 3′‐untranslated region of Runx2 mRNA to regulate its expression. CASMCs transfected with antagomirs to downregulate miR‐30b‐c demonstrated significantly increased Runx2, intracellular calcium deposition, and mineralization. Conversely, forced expression of miR‐30b‐c by transfection with pre–miR‐30b‐c prevented the increase in Runx2 expression and mineralization of SMCs. Calcified human coronary arteries demonstrated higher levels of BMP‐2 and lower levels of miR‐30b than did noncalcified donor coronary arteries. Conclusions: BMP‐2 downregulates miR‐30b and miR‐30c to increase Runx2 expression in CASMCs and promote mineralization. Strategies that modulate expression of miR‐30b and miR‐30c may influence vascular calcification

Determination of the nucleotide sequence of a human amylase gene and analysis of intron/exon structure

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Changing international student and business staff perceptions of in-sessional EAP: using the CEM model

This article addresses the question of whether the existing approach to EAP delivery implemented at the University of Northumbria is supporting the learning needs of the international student body. In addressing this the article documents the background, research and preliminary findings relating to provision of an in-sessional English for Academic Purposes (EAP) programme to international students studying in a business context. The article focuses on the management of the delivery of the EAP programme and is based on the experiences of two ‘subject champions’ from the English Language Centre and the postgraduate (PG) area of Newcastle Business School at Northumbria University. It documents research which has begun with an analysis and critique of past practice. This has led to the recognition of key issues which can influence the attendance and participation of overseas students on an in-sessional EAP programme. The article identifies and discusses the role of the three key concepts of contextualisation, embedding and mapping of the programme, as the foundation for managing in-sessional EAP delivery. The resulting model, the CEM Model, is designed to facilitate improved management of the provision of the EAP programme in a postgraduate business context. The findings show that application of the model can demonstrate added value in the key areas of design and content of an in-sessional EAP programme impacting on student attendance, understanding and integration of the programme with PG degree programme learning objectives and outcomes. To address the issue of sustaining the practice and benefits of the CEM Model the work concludes with the articulation of a framework which establishes the integration of the EAP programme within academic programmes both at the strategic level through Teaching and Learning policies and operational processes