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Pro-inflammatory conditions induced by products of protein glycation in diabetes substantially enhance the risk of endothelial dysfunction and related vascular complications. Endothelial cell specific molecule-1 (ESM-1) or endocan has been demonstrated as a potential biomarker in cancer and sepsis. Its role in diabetes-induced pathologies remains unknown. The expression of ESM-1 gene is under cytokine regulation, indicating its role in endothelium-dependent pathological disorders. In this study, we investigated the effect of advanced glycated human serum albumin (AGE-HSA) on the production of ESM-1. We show that AGE-HSA exerts a modulating role on the expression of ESM-1 in human umbilical vein endothelial cells. It up-regulates expression of ESM-1 protein in a dose-dependent manner which correlates with its messenger RNA (mRNA) transcription. RAGE and galectin-3, both AGE receptors, show antagonistic action on its expression. While gene silencing of RAGE has down-regulatory effect, that of galectin-3 has up-regulatory effect on AGE-induced expression of ESM-1. Inhibition of MAPKKK and JNK pathways did not alter the expression. In contrast, phosphatidylinositol 3 kinase (PI3K) inhibition significantly up-regulated ESM-1 expression. In conclusion, these results suggest that AGE-induced activation of human umbilical vein endothelial cells promotes formation of endocan which is an endothelial dysfunction marker and may be related to vascular disease in diabetes.

We report the synthesis of gold and silver nanostructures embedded in different dielectric matrices by atom beam co-sputtering, a novel technique. We have synthesized gold-silicon core shell nanostructures and Au-ZnO nanocomposite with tunable surface plasmon resonance (SPR) by atom beam co-sputtering and subsequent annealing. The Au-ZnO nanocomposite shows significant enhancement in intensity of Raman modes of fullerene molecules and therefore can help in surface enhanced Raman spectroscopy investigation of organic molecules. The synthesized Ag-polymer nanocomposite thin films show excellent features of broad SPR absorption extending upto IR region and a narrow transmission of light in UV region approximately 320 nm which could be of technological interest in solar absorbers and UV light filters respectively. The Ag-silica nanocomposite thin films show their utility in glucose sensing. The gold-silica nanocomposite thin films exhibit their possible use in detection of human ovarian cancer cells in a preliminary study. The shift in SPR peak of Au nanoparticles (NPs) present at the surface of silica synthesized by thermal evaporation and annealing, after attachment of biological molecules like proteins has been studied.

Advanced glycation end products (AGEs) are known to be involved in the pathogenesis of several diseases, in particular diabetes, via signaling through their receptor. Numerous studies have been carried out on protein-sugar interactions at very high concentrations of the latter. The objective of this investigation was to determine the effects of nonenzymatic glycation induced by reducing sugars on the secondary structure of human serum albumin (HSA) under different physiological conditions and to correlate that with expression of RAGE (receptor for advanced glycation end products) on HUVECs (human umbilical vein endothelial cells) in a controlled hemodynamic environment. Our results indicate that RAGE expression is shear stress modulated and that glycated HSA enhances the expression further. The secondary structure of AGE-HSA derived from glucose at 20 mM contains higher α-helical content and elicits maximum expression of the receptor. The effect of shear stress at 10 dynes cm(-2) is independent of AGE-HSA.