TY - JOUR A1 - Shi, Yaoyao A1 - Kuai, Yue A1 - Lei, Lizhen A1 - Weng, Yuanyuan A1 - Berberich-Siebelt, Friederike A1 - Zhang, Xinxia A1 - Wang, Jinjie A1 - Zhou, Yuan A1 - Jiang, Xin A1 - Ren, Guoping A1 - Pan, Hongyang A1 - Mao, Zhengrong A1 - Zhou, Ren T1 - The feedback loop of LITAF and BCL6 is involved in regulating apoptosis in B cell non-Hodgkin's-lymphoma JF - Oncotarget N2 - Dysregulation of the apoptotic pathway is widely recognized as a key step in lymphomagenesis. Notably, LITAF was initially identified as a p53-inducible gene, subsequently implicated as a tumor suppressor. Our previous study also showed LITAF to be methylated in 89.5% B-NHL samples. Conversely, deregulated expression of BCL6 is a pathogenic event in many lymphomas. Interestingly, our study found an oppositional expression of LITAF and BCL6 in B-NHL. In addition, LITAF was recently identified as a novel target gene of BCL6. Therefore, we sought to explore the feedback loop between LITAF and BCL6 in B-NHL. Here, our data for the first time show that LITAF can repress expression of BCL6 by binding to Region A (−87 to +65) containing a putative LITAF-binding motif (CTCCC) within the BCL6 promoter. Furthermore, the regulation of BCL6 targets (PRDM1 or c-Myc) by LITAF may be associated with B-cell differentiation. Results also demonstrate that ectopic expression of LITAF induces cell apoptosis, activated by releasing cytochrome c, cleaving PARP and caspase 3 in B-NHL cells whereas knockdown of LITAF robustly protected cells from apoptosis. Interestingly, BCL6, in turn, could reverse cell apoptosis mediated by LITAF. Collectively, our findings provide a novel apoptotic regulatory pathway in which LITAF, as a transcription factor, inhibits the expression of BCL6, which leads to activation of the intrinsic mitochondrial pathway and tumor apoptosis. Our study is expected to provide a possible biomarker as well as a target for clinical therapies to promote tumor cell apoptosis. KW - LITAF KW - BCL6 KW - apoptosis KW - lymphoma KW - B-cells Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166500 VL - 7 IS - 47 ER - TY - JOUR A1 - Schneider, Anna A1 - Corona, Angela A1 - Spöring, Imke A1 - Jordan, Mareike A1 - Buchholz, Bernd A1 - Maccioni, Elias A1 - Di Santo, Roberto A1 - Bodem, Jochen A1 - Tramontano, Enzo A1 - Wöhrl, Birgitta M. T1 - Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors JF - Nucleic Acids Research N2 - We analyzed a multi-drug resistant (MR) HIV-1 reverse transcriptase (RT), subcloned from a patient-derived subtype CRF02_AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azidothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to antagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most significant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimination, indicating that the two mechanisms are mutually exclusive and that the Q151M pathway is obviously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, additionally harboring the TAM K70R and the reversions M151Q as well as R65K since K65R antagonizes excision. MR-R65K-K70R-M151Q was competent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still promoted discrimination. To tackle the multi-drug resistance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors belonging to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs. KW - ribonuclease H KW - HIV-1 subtype AG KW - azidothymidine KW - reverse transcriptase KW - multi-drug resistance Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166423 VL - 44 IS - 5 ER - TY - JOUR A1 - Cui, Huanhuan A1 - Schlesinger, Jenny A1 - Schoenhals, Sophia A1 - Tonjes, Martje A1 - Dunkel, Ilona A1 - Meierhofer, David A1 - Cano, Elena A1 - Schulz, Kerstin A1 - Berger, Michael F. A1 - Haack, Timm A1 - Abdelilah-Seyfried, Salim A1 - Bulyk, Martha L. A1 - Sauer, Sascha A1 - Sperling, Silke R. T1 - Phosphorylation of the chromatin remodeling factor DPF3a induces cardiac hypertrophy through releasing HEY repressors from DNA JF - Nucleic Acids Research N2 - DPF3 (BAF45c) is a member of the BAF chromatin remodeling complex. Two isoforms have been described, namely DPF3a and DPF3b. The latter binds to acetylated and methylated lysine residues of histones. Here, we elaborate on the role of DPF3a and describe a novel pathway of cardiac gene transcription leading to pathological cardiac hypertrophy. Upon hypertrophic stimuli, casein kinase 2 phosphorylates DPF3a at serine 348. This initiates the interaction of DPF3a with the transcriptional repressors HEY, followed by the release of HEY from the DNA. Moreover, BRG1 is bound by DPF3a, and is thus recruited to HEY genomic targets upon interaction of the two components. Consequently, the transcription of downstream targets such as NPPA and GATA4 is initiated and pathological cardiac hypertrophy is established. In human, DPF3a is significantly up-regulated in hypertrophic hearts of patients with hypertrophic cardiomyopathy or aortic stenosis. Taken together, we show that activation of DPF3a upon hypertrophic stimuli switches cardiac fetal gene expression from being silenced by HEY to being activated by BRG1. Thus, we present a novel pathway for pathological cardiac hypertrophy, whose inhibition is a long-term therapeutic goal for the treatment of the course of heart failure. KW - phosphorylation KW - DPF3a KW - HEY repressors KW - DNA KW - cardiac hypertrophy Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166391 VL - 44 IS - 6 ER - TY - JOUR A1 - Schwarz, Roland F. A1 - Tamuri, Asif U. A1 - Kultys, Marek A1 - King, James A1 - Godwin, James A1 - Florescu, Ana M. A1 - Schultz, Jörg A1 - Goldman, Nick T1 - ALVIS: interactive non-aggregative visualization and explorative analysis of multiple sequence alignments JF - Nucleic Acids Research N2 - Sequence Logos and its variants are the most commonly used method for visualization of multiple sequence alignments (MSAs) and sequence motifs. They provide consensus-based summaries of the sequences in the alignment. Consequently, individual sequences cannot be identified in the visualization and covariant sites are not easily discernible. We recently proposed Sequence Bundles, a motif visualization technique that maintains a one-to-one relationship between sequences and their graphical representation and visualizes covariant sites. We here present Alvis, an open-source platform for the joint explorative analysis of MSAs and phylogenetic trees, employing Sequence Bundles as its main visualization method. Alvis combines the power of the visualization method with an interactive toolkit allowing detection of covariant sites, annotation of trees with synapomorphies and homoplasies, and motif detection. It also offers numerical analysis functionality, such as dimension reduction and classification. Alvis is user-friendly, highly customizable and can export results in publication-quality figures. It is available as a full-featured standalone version (http://www.bitbucket.org/rfs/alvis) and its Sequence Bundles visualization module is further available as a web application (http://science-practice.com/projects/sequence-bundles). KW - visualization KW - multiple sequence alignments KW - phylogenetic trees KW - Alvis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166374 VL - 44 IS - 8 ER - TY - JOUR A1 - Letunic, Ivica A1 - Bork, Peer T1 - Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees JF - Nucleic Acids Research N2 - Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. The current version was completely redesigned and rewritten, utilizing current web technologies for speedy and streamlined processing. Numerous new features were introduced and several new data types are now supported. Trees with up to 100,000 leaves can now be efficiently displayed. Full interactive control over precise positioning of various annotation features and an unlimited number of datasets allow the easy creation of complex tree visualizations. iTOL 3 is the first tool which supports direct visualization of the recently proposed phylogenetic placements format. Finally, iTOL's account system has been redesigned to simplify the management of trees in user-defined workspaces and projects, as it is heavily used and currently handles already more than 500,000 trees from more than 10,000 individual users. KW - Interactive Tree Of Life (iTOL) KW - phylogenetic trees KW - visualization KW - tool Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166181 VL - 44 IS - W1 ER - TY - JOUR A1 - Telorac, Jonas A1 - Prykhozhij, Sergey V. A1 - Schöne, Stefanie A1 - Meierhofer, David A1 - Sauer, Sascha A1 - Thomas-Chollier, Morgane A1 - Meijsing, Sebastiaan H. T1 - Identification and characterization of DNA sequences that prevent glucocorticoid receptor binding to nearby response elements JF - Nucleic Acids Research N2 - Out of the myriad of potential DNA binding sites of the glucocorticoid receptor (GR) found in the human genome, only a cell-type specific minority is actually bound, indicating that the presence of a recognition sequence alone is insufficient to specify where GR binds. Cooperative interactions with other transcription factors (TFs) are known to contribute to binding specificity. Here, we reasoned that sequence signals preventing GR recruitment to certain loci provide an alternative means to confer specificity. Motif analyses uncovered candidate Negative Regulatory Sequences (NRSs) that interfere with genomic GR binding. Subsequent functional analyses demonstrated that NRSs indeed prevent GR binding to nearby response elements. We show that NRS activity is conserved across species, found in most tissues and that they also interfere with the genomic binding of other TFs. Interestingly, the effects of NRSs appear not to be a simple consequence of changes in chromatin accessibility. Instead, we find that NRSs interact with proteins found at sub-nuclear structures called paraspeckles and that these proteins might mediate the repressive effects of NRSs. Together, our studies suggest that the joint influence of positive and negative sequence signals partition the genome into regions where GR can bind and those where it cannot. KW - DNA sequencing KW - glucocorticoid receptor KW - DNA binding KW - transcription factors Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166330 VL - 44 IS - 13 ER - TY - JOUR A1 - Alma, Harma A1 - de Jong, Corina A1 - Jelusic, Danijel A1 - Wittmann, Michael A1 - Schuler, Michael A1 - Flokstra-de Blok, Bertine A1 - Kocks, Janwillem A1 - Schultz, Konrad A1 - van der Molen, Thys T1 - Health status instruments for patients with COPD in pulmonary rehabilitation: defining a minimal clinically important difference JF - npj Primary Care Respiration Medicine N2 - The minimal clinically important difference (MCID) defines to what extent change on a health status instrument is clinically relevant, which aids scientists and physicians in measuring therapy effects. This is the first study that aimed to establish the MCID of the Clinical chronic obstructive pulmonary disease (COPD) Questionnaire (CCQ), the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ) in the same pulmonary rehabilitation population using multiple approaches. In total, 451 COPD patients participated in a 3-week Pulmonary Rehabilitation (PR) programme (58 years, 65% male, 43 pack-years, GOLD stage II/III/IV 50/39/11%). Techniques used to assess the MCID were anchor-based approaches, including patient-referencing, criterion-referencing and questionnaire-referencing, and the distribution-based methods standard error of measurement (SEM), 1.96SEM and half standard deviation (0.5s.d.). Patient- and criterion-referencing led to MCID estimates of 0.56 and 0.62 (CCQ); 3.12 and 2.96 (CAT); and 8.40 and 9.28 (SGRQ). Questionnaire-referencing suggested MCID ranges of 0.28–0.61 (CCQ), 1.46–3.08 (CAT) and 6.86–9.47 (SGRQ). The SEM, 1.96SEM and 0.5s.d. were 0.29, 0.56 and 0.46 (CCQ); 3.28, 6.43 and 2.80 (CAT); 5.20, 10.19 and 6.06 (SGRQ). Pooled estimates were 0.52 (CCQ), 3.29 (CAT) and 7.91 (SGRQ) for improvement. MCID estimates differed depending on the method used. Pooled estimates suggest clinically relevant improvements needing to exceed 0.40 on the CCQ, 3.00 on the CAT and 7.00 on the SGRQ for moderate to very severe COPD patients. The MCIDs of the CAT and SGRQ in the literature might be too low, leading to overestimation of treatment effects for patients with COPD. KW - COPD KW - rehabilitation KW - health status instruments Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166327 VL - 26 IS - 16041 ER - TY - JOUR A1 - Redlich, Christoph A1 - Lingnau, Benjamin A1 - Holzinger, Steffen A1 - Schlottmann, Elisabeth A1 - Kreinberg, Sören A1 - Schneider, Christian A1 - Kamp, Martin A1 - Höfling, Sven A1 - Wolters, Janik A1 - Reitzenstein, Stephan A1 - Lüdge, Kathy T1 - Mode-switching induced super-thermal bunching in quantum-dot microlasers JF - New Journal of Physics N2 - The super-thermal photon bunching in quantum-dot (QD) micropillar lasers is investigated both experimentally and theoretically via simulations driven by dynamic considerations. Using stochastic multi-mode rate equations we obtain very good agreement between experiment and theory in terms of intensity profiles and intensity-correlation properties of the examined QD micro-laser's emission. Further investigations of the time-dependent emission show that super-thermal photon bunching occurs due to irregular mode-switching events in the bimodal lasers. Our bifurcation analysis reveals that these switchings find their origin in an underlying bistability, such that spontaneous emission noise is able to effectively perturb the two competing modes in a small parameter region. We thus ascribe the observed high photon correlation to dynamical multistabilities rather than quantum mechanical correlations. KW - microlaser KW - nonlinear dynamics KW - correlation properties KW - photon statistics KW - noise and multimode dynamics KW - quantum dot laser Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166286 VL - 18 IS - 063011 ER - TY - JOUR A1 - Hargart, F A1 - Roy-Choudhury, K A1 - John, T A1 - Portalupi, S L A1 - Schneider, C A1 - Höfling, S A1 - Kamp, M A1 - Hughes, S A1 - Michler, P T1 - Probing different regimes of strong field light-matter interaction with semiconductor quantum dots and few cavity photons JF - New Journal of Physics N2 - In this work we present an extensive experimental and theoretical investigation of different regimes of strong field light–matter interaction for cavity-driven quantum dot (QD) cavity systems. The electric field enhancement inside a high-Q micropillar cavity facilitates exceptionally strong interaction with few cavity photons, enabling the simultaneous investigation for a wide range of QD-laser detuning. In case of a resonant drive, the formation of dressed states and a Mollow triplet sideband splitting of up to 45 μeV is measured for amean cavity photon number \(\leq\) 1. In the asymptotic limit of the linear ACStark effect we systematically investigate the power and detuning dependence of more than 400 QDs. Some QD-cavity systems exhibit an unexpected anomalous Stark shift, which can be explained by an extended dressed 4-levelQDmodel.Weprovide a detailed analysis of the QD-cavity systems properties enabling this novel effect. The experimental results are successfully reproduced using a polaron master equation approach for the QD-cavity system, which includes the driving laser field, exciton-cavity and exciton-phonon interactions KW - light–matter interaction KW - quantum dots KW - AC Stark effect KW - dressed states Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166278 VL - 18 ER - TY - JOUR A1 - van de Kerkhof, Nora WA A1 - Fekkes, Durk A1 - van der Heijden, Frank MMA A1 - Hoogendijk, Witte JG A1 - Stöber, Gerald A1 - Egger, Jos IM A1 - Verhoeven, Willem MA T1 - Cycloid psychoses in the psychosis spectrum: evidence for biochemical differences with schizophrenia JF - Neuropsychiatric Disease and Treatment N2 - Cycloid psychoses (CP) differ from schizophrenia regarding symptom profile, course, and prognosis and over many decades they were thought to be a separate entity within the psychosis spectrum. As to schizophrenia, research into the pathophysiology has focused on dopamine, brain-derived neurotrophic factor, and glutamate signaling in which, concerning the latter, the N-methyl-d-aspartate receptor plays a crucial role. The present study aims to determine whether CP can biochemically be delineated from schizophrenia. Eighty patients referred for psychotic disorders were assessed with the Comprehensive Assessment of Symptoms and History, and (both at inclusion and after 6 weeks of antipsychotic treatment) with the Positive and Negative Syndrome Scale and Clinical Global Impression. From 58 completers, 33 patients were diagnosed with schizophrenia and ten with CP according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and Leonhard criteria, respectively. Fifteen patients were diagnosed with other disorders within the psychosis spectrum. At both time points, blood levels of the dopamine metabolite homovanillic acid, brain-derived neurotrophic factor, and amino acids related to glutamate neurotransmission were measured and compared with a matched control sample. Patients with CP showed a significantly better response to antipsychotic treatment as compared to patients with schizophrenia. In CP, glycine levels were elevated and tryptophan levels were lowered as compared to schizophrenia. Glutamate levels were increased in both patient groups as compared to controls. These results, showing marked differences in both treatment outcome and glutamate-related variable parameters, may point at better neuroplasticity in CP, necessitating demarcation of this subgroup within the psychosis spectrum. KW - cycloid psychoses KW - schizophrenia KW - glutamate KW - glycine KW - tryptophan KW - neuroplasticity Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166255 VL - 12 ER -