13 research outputs found

    A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

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    Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

    Irony comprehension and context processing in schizophrenia during remission - A functional MRI study.

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    Schizophrenic patients have Theory of Mind (ToM) deficits even during remission, but it is yet unknown whether this could be influenced. We examined the neural correlates of irony understanding in schizophrenic patients, as an indicator of ToM capacity, and evaluated how linguistic help inserted into the context phase could affect irony comprehension. Schizophrenic patients in remission and healthy controls were subjected to event-related functional MRI scanning while performing irony, 'irony with linguistic help', and control tasks. Patients understood irony significantly worse than healthy controls. The patients showed stronger brain activity in the parietal and frontal areas in the early phase of irony task, however the healthy controls exhibited higher activation in frontal, temporal and parietal regions in the latter phase of the irony task. Interestingly the linguistic help not only improved the patients' ToM performance, but it also evoked similar activation pattern to healthy controls

    Mechanisms of Nitric Oxide Reactions Mediated by Biologically Relevant Metal Centers

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    Progress in biopolymer-based biomaterials and their application in controlled drug delivery

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