700 research outputs found

    Dynorphin gene expression and release in the myocardial cell.

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    The expression of the prodynorphin gene was investigated in adult cultured rat ventricular cardiac myocytes by using a sensitive solution hybridization RNase protection assay for the quantitative analysis of prodynorphin mRNA. Myocyte culture in high KCl resulted, after 4 h, in a marked increase in cellular prodynorphin mRNA, while a KCl treatment for 6, 12, or 24 h progressively down-regulated the levels of prodynorphin mRNA below the control value. Immunoreactive dynorphin B, a biologically active end product of the precursor, was found to be present in the culture medium in significantly higher amounts than in the cardiac myocytes. The levels of this biologically active K opioid receptor agonist significantly increased after 4 h of KCl treatment and were markedly reduced following a 24-h exposure of the cardiac myocytes to KCl. These KCl-induced effects were all abolished by cell incubation in the presence of the calcium channel blocker verapamil. In single cardiac myocytes, acute stimulation of K opioid receptors with dynorphin B or with the selective agonist U-50,488H increased the level of cytosolic calcium. This effect was abolished by the specific K opioid receptor antagonist (Mr-1452) and was not affected by the removal of calcium from the bathing medium. These results suggest that an opioid gene may influence the myocardial function in an autocrine or paracrine fashion

    Design and Pharmacological Characterization of α4ÎČ1 Integrin Cyclopeptide Agonists: Computational Investigation of Ligand Determinants for Agonism versus Antagonism

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    alpha 4 beta 1 integrin is a cell adhesion receptor deeply involved in the migration and accumulation of leukocytes. Therefore, integrin antagonists that inhibit leukocytes recruitment are currently regarded as a therapeutic opportunity for the treatment of inflammatory disorder, including leukocyte-related autoimmune diseases. Recently, it has been suggested that integrin agonists capable to prevent the release of adherent leukocytes might serve as therapeutic agents as well. However, very few alpha 4 beta 1 integrin agonists have been discovered so far, thus precluding the investigation of their potential therapeutic efficacy. In this perspective, we synthesized cyclopeptides containing the LDV recognition motif found in the native ligand fibronectin. This approach led to the discovery of potent agonists capable to increase the adhesion of alpha 4 integrin-expressing cells. Conformational and quantum mechanics computations predicted distinct ligand-receptor interactions for antagonists or agonists, plausibly referable to receptor inhibition or activation

    Leukocyte Integrin Antagonists as a Novel Option to Treat Dry Age-Related Macular Degeneration

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    Age-related macular degeneration (AMD) is a complex multifactorial degenerative disease that leads to irreversible blindness. AMD affects the macula, the central part of the retina responsible for sharp central vision. Retinal pigment epithelium (RPE) is the main cellular type affected in dry AMD. RPE cells form a monolayer between the choroid and the neuroretina and are in close functional relationship with photoreceptors; moreover, RPE cells are part of the blood retina barrier that is disrupted in ocular diseases such as AMD. During ocular inflammation lymphocytes and macrophages are recruited, contact RPE and produce pro-inflammatory cytokines, which play an important role in AMD pathogenesis. The interaction between RPE and immune cells is mediated by leukocyte integrins, heterodimeric transmembrane receptors, and adhesion molecules, including VCAM-1 and ICAM-1. Within this frame, this study aimed to characterize RPE-leukocytes interaction and to investigate any potentially beneficial effects induced by integrin antagonists (DS-70, MN27 and SR714), developed in previous studies. ARPE-19 cells were co-cultured for different incubation times with Jurkat cells and apoptosis and necrosis levels were analyzed by flow cytometry. Moreover, we measured the mRNA levels of the pro-inflammatory cytokine IL-1\u3b2 and the expression of adhesion molecules VCAM-1 and ICAM-1. We found that RPE-lymphocyte interaction increased apoptosis and necrosis levels in RPE cells and the expression of IL-1\u3b2. This interaction was mediated by the binding of \u3b14\u3b21 and \u3b1L\u3b22 integrins to VCAM-1 and ICAM-1, respectively. The blockade of RPE-lymphocyte interaction with blocking antibodies highlighted the pivotal role played by integrins. Therefore, \u3b14\u3b21 and \u3b1L\u3b22 integrin antagonists were employed to disrupt RPE-lymphocyte crosstalk. Small molecule integrin antagonists proved to be effective in reducing RPE cell death and expression of IL-1\u3b2, demonstrating that integrin antagonists could protect RPE cells from detrimental effects induced by the interaction with immune cells recruited to the retina. Overall, the leukocyte integrin antagonists employed in the present study may represent a novel opportunity to develop new drugs to fight dry AMD

    “Don’t blame the shopkeeper!!” Food, drink and confectionery advertising and British Government market controls during the Second World War

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    A novel series of \u3b2-lactam derivatives that was designed and synthesized to target RGD-binding and leukocyte integrins is reported. The compound library was evaluated by investigating the effects on integrin-mediated cell adhesion and cell signaling in cell lines expressing \u3b1v\u3b23, \u3b1v\u3b25, \u3b1v\u3b26, \u3b15\u3b21, \u3b1IIb\u3b23, \u3b14\u3b21, and \u3b1L\u3b22 integrins. SAR analysis of the new series of azetidinones enabled the recognition of structural elements associated with integrin selectivity. We obtained selective and potent agonists that could induce cell adhesion and promote cell signaling mediated by \u3b1v\u3b23, \u3b1v\u3b25, \u3b15\u3b21, or \u3b14\u3b21 integrin, and antagonists for the integrins \u3b1v\u3b23 and \u3b15\u3b21, as well as \u3b14\u3b21 and \u3b1L\u3b22, preventing the effects elicited by the respective endogenous agonists

    Eosinophil as a cellular target of the ocular anti-allergic action of mapracorat, a novel selective glucocorticoid receptor agonist

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    Abstract: Purpose: Glucocorticoids can either suppress gene transcription (transrepression) or activate it (transactivation). This latter process may contribute to certain side effects caused by these agents. Mapracorat (also known as BOL-303242-X or ZK 245186) is a novel selective glucocorticoid receptor agonist that maintains a beneficial anti-inflammatory activity but seems to be less effective in transactivation, resulting in a lower potential for side effects; it has been proposed for the topical treatment of inflammatory skin disorders. This study assessed the anti-allergic activity of mapracorat at the ocular level and whether eosinophils and mast cells are targets of its action

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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