TY  - JOUR
A1  - Wohlfarth, Carolin
A1  - Schmitteckert, Stefanie
A1  - Härtle, Janina D.
A1  - Houghton, Lesley A.
A1  - Dweep, Harsh
A1  - Fortea, Marina
A1  - Assadi, Ghazaleh
A1  - Braun, Alexander
A1  - Mederer, Tanja
A1  - Pöhner, Sarina
A1  - Becker, Philip P.
A1  - Fischer, Christine
A1  - Granzow, Martin
A1  - Mönnikes, Hubert
A1  - Mayer, Emeran A.
A1  - Sayuk, Gregory
A1  - Boeckxstaens, Guy
A1  - Wouters, Mira M.
A1  - Simrén, Magnus
A1  - Lindberg, Greger
A1  - Ohlsson, Bodil
A1  - Schmidt, Peter Thelin
A1  - Dlugosz, Aldona
A1  - Agreus, Lars
A1  - Andreasson, Anna
A1  - D'Amato, Mauro
A1  - Burwinkel, Barbara
A1  - Bermejo, Justo Lorenzo
A1  - Röth, Ralph
A1  - Lasitschka, Felix
A1  - Vicario, Maria
A1  - Metzger, Marco
A1  - Santos, Javier
A1  - Rappold, Gudrun A.
A1  - Martinez, Cristina
A1  - Niesler, Beate
T1  - miR-16 and miR-103 impact 5-HT4 receptor signalling and correlate with symptom profile in irritable bowel syndrome
JF  - Scientific Reports
N2  - Irritable bowel syndrome (IBS) is a gut-brain disorder involving alterations in intestinal sensitivity and motility. Serotonin 5-HT4 receptors are promising candidates in IBS pathophysiology since they regulate gut motor function and stool consistency, and targeted 5-HT4R selective drug intervention has been proven beneficial in subgroups of patients. We identified a single nucleotide polymorphism (SNP) (rs201253747) c.*61 T > C within the 5-HT4 receptor gene \(HTR4\) to be predominantly present in diarrhoea-IBS patients (IBS-D). It affects a binding site for the miR-16 family and miR-103/miR-107 within the isoforms \({HTR4b/i}\) and putatively impairs \(HTR4\) expression. Subsequent miRNA profiling revealed downregulation of miR-16 and miR-103 in the jejunum of IBS-D patients correlating with symptoms. \(In\) \(vitro\) assays confirmed expression regulation via three 3′UTR binding sites. The novel isoform \(HTR4b\_2\) lacking two of the three miRNA binding sites escapes miR-16/103/107 regulationin SNP carriers. We provide the first evidence that \(HTR4\) expression is fine-tuned by miRNAs, and that this regulation is impaired either by the SNP c.*61 T > C or bydiminished levels of miR-16 and miR-103 suggesting that \(HTR4\) might be involved in the development of IBS-D.
KW  - Medicine
KW  - Gene regulation
KW  - Irritable bowel syndrome
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173478
VL  - 7
ER  - 
TY  - JOUR
A1  - Appelt-Menzel, Antje
A1  - Cubukova, Alevtina
A1  - Günther, Katharina
A1  - Edenhofer, Frank
A1  - Piontek, Jörg
A1  - Krause, Gerd
A1  - Stüber, Tanja
A1  - Walles, Heike
A1  - Neuhaus, Winfried
A1  - Metzger, Marco
T1  - Establishment of a Human Blood-Brain Barrier Co-culture Model Mimicking the Neurovascular Unit Using Induced Pluri- and Multipotent Stem Cells
JF  - Stem Cell Reports
N2  - In vitro models of the human blood-brain barrier (BBB) are highly desirable for drug development. This study aims to analyze a set of ten different BBB culture models based on primary cells, human induced pluripotent stem cells (hiPSCs), and multipotent fetal neural stem cells (fNSCs). We systematically investigated the impact of astrocytes, pericytes, and NSCs on hiPSC-derived BBB endothelial cell function and gene expression. The quadruple culture models, based on these four cell types, achieved BBB characteristics including transendothelial electrical resistance (TEER) up to 2,500 Ω cm\(^{2}\) and distinct upregulation of typical BBB genes. A complex in vivo-like tight junction (TJ) network was detected by freeze-fracture and transmission electron microscopy. Treatment with claudin-specific TJ modulators caused TEER decrease, confirming the relevant role of claudin subtypes for paracellular tightness. Drug permeability tests with reference substances were performed and confirmed the suitability of the models for drug transport studies.
KW  - blood-brain barrier (BBB) model
KW  - human induced pluripotent stem cells (hiPSCs)human induced pluripotent stem cells (hiPSCs)
KW  - multipotent fetal neural stem cells (fNSCs)
KW  - neurovascular unit in vitro
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170982
VL  - 8
IS  - 4
ER  - 
TY  - JOUR
A1  - Straßer, Marion
A1  - Schrauth, Joachim H. X.
A1  - Dembski, Sofia
A1  - Haddad, Daniel
A1  - Ahrens, Bernd
A1  - Schweizer, Stefan
A1  - Christ, Bastian
A1  - Cubukova, Alevtina
A1  - Metzger, Marco
A1  - Walles, Heike
A1  - Jakob, Peter M.
A1  - Sextl, Gerhard
T1  - Calcium fluoride based multifunctional nanoparticles for multimodal imaging
JF  - Beilstein Journal of Nanotechnology
N2  - New multifunctional nanoparticles (NPs) that can be used as contrast agents (CA) in different imaging techniques, such as photoluminescence (PL) microscopy and magnetic resonance imaging (MRI), open new possibilities for medical imaging, e.g., in the fields of diagnostics or tissue characterization in regenerative medicine. The focus of this study is on the synthesis and characterization of CaF\(_{2}\):(Tb\(^{3+}\),Gd\(^{3+}\)) NPs. Fabricated in a wet-chemical procedure, the spherical NPs with a diameter of 5–10 nm show a crystalline structure. Simultaneous doping of the NPs with different lanthanide ions, leading to paramagnetism and fluorescence, makes them suitable for MR and PL imaging. Owing to the Gd\(^{3+}\) ions on the surface, the NPs reduce the MR T\(_{1}\) relaxation time constant as a function of their concentration. Thus, the NPs can be used as a MRI CA with a mean relaxivity of about r = 0.471 mL·mg\(^{−1}\)·s\(^{−1}\). Repeated MRI examinations of four different batches prove the reproducibility of the NP synthesis and determine the long-term stability of the CAs. No cytotoxicity of NP concentrations between 0.5 and 1 mg·mL\(^{−1}\) was observed after exposure to human dermal fibroblasts over 24 h. Overall this study shows, that the CaF\(_{2}\):(Tb\(^{3+}\),Gd\(^{3+}\)) NPs are suitable for medical imaging.
KW  - calcium fluoride nanoparticles
KW  - magnetic resonance imaging (MRI)
KW  - multifunctional nanoparticles
KW  - multimodal imaging
KW  - photoluminescence
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170657
VL  - 8
ER  -