1,373 research outputs found

    The secretome of stem cells isolated from the adipose tissue and wharton jelly acts differently on central nervous system derived cell populations

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    Introduction: It is hypothesized that administration of stromal/stem cells isolated from the adipose tissue (ASCs) and umbilical cord (HUCPVCs) can ameliorate the inured CNS. However it is still not clear whether they have similar or opposite effects on primary cultures of neuronal populations. The objective of the present work was to determine if ASCs and HUCPVCs preferentially act, or not, on specific cell populations within the CNS. Methods: Primary cultures of hippocampal neurons were exposed to ASCs and HUCPVCs conditioned media (CM) (obtained 24, 48, 72 and 96 hours after 3 days of culture) for 1 week. Results: Cell viability experiments (MTS test) revealed that CM obtained from both cell populations at all time points did not cause any deleterious effects on neuronal cells. In fact, it was determined that whenever the ASCs CM were supplemented with bFGF and B27, there was a significant increase on the metabolic viability and neuronal cell density of the cultures. On the other hand in the absence of CM supplementation, it was the HUCPVCs secretome that had the highest impact on the metabolic viability and cell density. In an attempt to unveil which factors could be involved in the observed effects, a screening for the presence of basic fibroblast growth factor (bFGF), nerve growth factor (NGF), stem cell factor (SCF), hepatocyte growth factors (HGF) and vascular endothelial growth factor (VEGF) in the CM was performed. Results revealed the presence of all these factors in ASCs CM, except bFGF; in contrast, in HUCPVCs CM it was only possible to detect robust NGF expression. Conclusions: Overall the results herein confirm important differences on the secretome of ASCs and HUCPVCs, which leads to distinct effects on the metabolic viability and neuronal cell densities in primary cultures of hippocampal neurons; however, the factor(s) that promote the stronger effect of the HUCPVCs CM in neuronal survival is (are) still to be identified.Pennington Biomedical Research FoundationFoundation Calouste de Gulbenkian - The Gulbenkian Programme to Support Research in the Life Sciences and Ciência 2007 ProgramFundação para a Ciência e a Tecnologia (FCT

    New Cardiovascular and Pulmonary Therapeutic Strategies Based on the Angiotensin-Converting Enzyme 2/Angiotensin-(1–7)/Mas Receptor Axis

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    Angiotensin (Ang)-(1–7) is now recognized as a biologically active component of the renin-angiotensin system (RAS). The discovery of the angiotensin-converting enzyme homologue ACE2 revealed important metabolic pathways involved in the Ang-(1–7) synthesis. This enzyme can form Ang-(1–7) from Ang II or less efficiently through hydrolysis of Ang I to Ang-(1–9) with subsequent Ang-(1–7) formation. Additionally, it is well established that the G protein-coupled receptor Mas is a functional ligand site for Ang-(1–7). The axis formed by ACE2/Ang-(1–7)/Mas represents an endogenous counter regulatory pathway within the RAS whose actions are opposite to the vasoconstrictor/proliferative arm of the RAS constituted by ACE/Ang II/AT1 receptor. In this review we will discuss recent findings concerning the biological role of the ACE2/Ang-(1–7)/Mas arm in the cardiovascular and pulmonary system. Also, we will highlight the initiatives to develop potential therapeutic strategies based on this axis

    1-Methyl-7-(4-nitro­phen­yl)-3-phenyl­pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine-6,8(3H,7H)-dione

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    In the title compound, C21H13N5O4, the dihedral angles formed between the planes of the phenyl and nitro­phenyl rings and that of the heterotricyclic plane are 41.29 (7) and 61.35 (6)°, respectively. In the crystal, weak C—H⋯O interactions help to establish the packing

    Semiclassical thermodynamics of scalar fields

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    We present a systematic semiclassical procedure to compute the partition function for scalar field theories at finite temperature. The central objects in our scheme are the solutions of the classical equations of motion in imaginary time, with spatially independent boundary conditions. Field fluctuations -- both field deviations around these classical solutions, and fluctuations of the boundary value of the fields -- are resummed in a Gaussian approximation. In our final expression for the partition function, this resummation is reduced to solving certain ordinary differential equations. Moreover, we show that it is renormalizable with the usual 1-loop counterterms.Comment: 24 pages, 5 postscript figure

    (2E)-N′-[(E)-4-Chloro­benzyl­idene]-3-phenyl­prop-2-enohydrazide monohydrate

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    The conformation about each of the imine and ethene bonds in the title hydrazide hydrate, C16H13ClN2O·H2O, is E. The hydrazide mol­ecule is approximately planar (r.m.s. deviation of the 20 non-H atoms = 0.172 Å). The most significant twist occurs about the ethene bond [C—C=C—C = 164.1 (5)°] and the dihedral angle formed between the benzene rings is 5.3 (2)°]. In the crystal, the presence of N—H⋯Ow and O—H⋯Oc (× 2; w = water and c = carbon­yl) hydrogen bonds leads to a supra­molecular array in the bc plane

    Epigenetic Mechanisms Regulate MHC and Antigen Processing Molecules in Human Embryonic and Induced Pluripotent Stem Cells

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    Background Human embryonic stem cells (hESCs) are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC) class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored. Methodology/Principal Findings We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM) components and NKG2D ligands (NKG2D-L) in hESCs, induced pluripotent stem cells (iPSCs) and NTera2 (NT2) teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP) assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1) and tapasin (TPN) components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of β2-microglobulin (β2m) light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB) were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and β2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs). Absence of HLA-DR and HLA-G expression was regulated by DNA methylation. Conclusions/Significance Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance

    Different molecular conformations in the crystal structures of three 5-nitroimidazolyl derivatives

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    Acknowledgements We thank the EPSRC National Crystallography Service (University of Southampton) for the X-ray data collections.Peer reviewedPublisher PD
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