13 research outputs found

    Plasmonic Hepatitis B Biosensor for the Analysis of Clinical Saliva

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    A biosensor for the detection of hepatitis B antibodies in clinical saliva was developed. Compared to conventional analysis of blood serum, it offers the advantage of noninvasive collection of samples. Detection of biomarkers in saliva imposes two major challenges associated with the low analyte concentration and increased surface fouling. The detection of minute amounts of hepatitis B antibodies was performed by plasmonically amplified fluorescence sandwich immunoassay. To have access to specific detection, we prevented the nonspecific adsorption of biomolecules present in saliva by brushes of poly[(N-(2-hydroxypropyl) methacrylamide)-co-(carboxybetaine methacrylamide)] grafted from the gold sensor surface and post modified with hepatitis B surface antigen. Obtained results were validated against the response measured with ELISA at a certified laboratory using serum from the same patients. © 201

    Methyl-binding domain protein-based DNA isolation from human blood serum combines DNA analyses and serum-autoantibody testing

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    <p>Abstract</p> <p>Background</p> <p>Circulating cell free DNA in serum as well as serum-autoantibodies and the serum proteome have great potential to contribute to early cancer diagnostics via non invasive blood tests. However, most DNA preparation protocols destroy the protein fraction and therefore do not allow subsequent protein analyses. In this study a novel approach based on methyl binding domain protein (MBD) is described to overcome the technical difficulties of combining DNA and protein analysis out of one single serum sample.</p> <p>Methods</p> <p>Serum or plasma samples from 98 control individuals and 54 breast cancer patients were evaluated upon silica membrane- or MBD affinity-based DNA isolation via qPCR targeting potential DNA methylation markers as well as by protein-microarrays for tumor-autoantibody testing.</p> <p>Results</p> <p>In control individuals, an average DNA level of 22.8 ± 25.7 ng/ml was detected applying the silica membrane based protocol and 8.5 ± 7.5 ng/ml using the MBD-approach, both values strongly dependent on the serum sample preparation methods used. In contrast to malignant and benign tumor serum samples, cell free DNA concentrations were significantly elevated in sera of metastasizing breast cancer patients. Technical evaluation revealed that serum upon MBD-based DNA isolation is suitable for protein-array analyses when data are consistent to untreated serum samples.</p> <p>Conclusion</p> <p>MBD affinity purification allows DNA isolations under native conditions retaining the protein function, thus for example enabling combined analyses of DNA methylation and autoantigene-profiles from the same serum sample and thereby improving minimal invasive diagnostics.</p

    Epigenetic Profile of Human Adventitial Progenitor Cells Correlates With Therapeutic Outcomes in a Mouse Model of Limb Ischemia

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    Objective— We investigated the association between the functional, epigenetic, and expressional profile of human adventitial progenitor cells (APCs) and therapeutic activity in a model of limb ischemia. Approach and Results— Antigenic and functional features were analyzed throughout passaging in 15 saphenous vein (SV)–derived APC lines, of which 10 from SV leftovers of coronary artery bypass graft surgery and 5 from varicose SV removal. Moreover, 5 SV-APC lines were transplanted (8×10 5 cells, IM) in mice with limb ischemia. Blood flow and capillary and arteriole density were correlated with functional characteristics and DNA methylation/expressional markers of transplanted cells. We report successful expansion of tested lines, which reached the therapeutic target of 30 to 50 million cells in ≈10 weeks. Typical antigenic profile, viability, and migratory and proangiogenic activities were conserved through passaging, with low levels of replicative senescence. In vivo, SV-APC transplantation improved blood flow recovery and revascularization of ischemic limbs. Whole genome screening showed an association between DNA methylation at the promoter or gene body level and microvascular density and to a lesser extent with blood flow recovery. Expressional studies highlighted the implication of an angiogenic network centered on the vascular endothelial growth factor receptor as a predictor of microvascular outcomes. FLT-1 gene silencing in SV-APCs remarkably reduced their ability to form tubes in vitro and support tube formation by human umbilical vein endothelial cells, thus confirming the importance of this signaling in SV-APC angiogenic function. Conclusions— DNA methylation landscape illustrates different therapeutic activities of human APCs. Epigenetic screening may help identify determinants of therapeutic vasculogenesis in ischemic disease. </jats:sec

    Liquid-biopsy based Multi-Omics Technologies ready to be used in Psychoimmunology

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    Multi-Omics strategies are amongst the approaches at the forefront of personalized medicine and are grounded in the understanding that complex diseases cannot be fully characterized by isolate bio measures. Rather, interactions between genes, transcripts, proteins, metabolites, and the environment determine the development and trajectory of complex diseases which not least include psychiatric disorders.Along these lines we will introduce the manifold omics workflows established in our research group which are all based on multiplex high throughput technologies (DNA &amp; protein microarrays, Next generation sequencing, Luminex bead technology and microfluidic qPCR) and enable the analysis of a whole range of different biomolecules [DNA (methylation), mRNA, small RNAs, proteins, antibodies]. We will present and showcase different examples of multi-omics biomarker discovery -and validation studies performed by us in diverse complex diseases including immune-mediated diseases. A special focus will hereby be given to analyses from biofluids including whole blood, plasma, cerebrospinal fluid, cell-free saliva and body-fluid derived extracellular vesicles and to technologies particularly suited for psychoimmunology research

    Increased antioxidant defense mechanism in human adventitia-derived progenitor cells is associated with therapeutic benefit in ischemia

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    Aims: Vascular wall-resident progenitor cells hold great promise for cardiovascular regenerative therapy. This study evaluates the impact of oxidative stress on the viability and functionality of adventitia-derived progenitor cells (APCs) from vein remnants of coronary artery bypass graft (CABG) surgery. We also investigated the antioxidant enzymes implicated in the resistance of APCs to oxidative stress-induced damage and the effect of interfering with one of them, the extracellular superoxide dismutase (EC-SOD/SOD3), on APC therapeutic action in a model of peripheral ischemia. Results: After exposure to hydrogen peroxide, APCs undergo apoptosis to a smaller extent than endothelial cells (ECs). This was attributed to up-regulation of antioxidant enzymes, especially SODs and catalase. Pharmacological inhibition of SODs increases reactive oxygen species (ROS) levels in APCs and impairs their survival. Likewise, APC differentiation results in SOD down-regulation and ROS-induced apoptosis. Oxidative stress increases APC migratory activity, while being inhibitory for ECs. In addition, oxidative stress does not impair APC capacity to promote angiogenesis in vitro. In a mouse limb ischemia model, an injection of naïve APCs, but not SOD3-silenced APCs, helps perfusion recovery and neovascularization, thus underlining the importance of this soluble isoform in protection from ischemia. Innovation: This study newly demonstrates that APCs are endowed with enhanced detoxifier and antioxidant systems and that SOD3 plays an important role in their therapeutic activity in ischemia. Conclusions: APCs from vein remnants of CABG patients express antioxidant defense mechanisms, which enable them to resist stress. These properties highlight the potential of APCs in cardiovascular regenerative medicine. Antioxid. Redox Signal. 21, 1591–1604
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