TY  - JOUR
A1  - Schihada, Hannes
A1  - Vandenabeele, Sylvie
A1  - Zabel, Ulrike
A1  - Frank, Monika
A1  - Lohse, Martin J.
A1  - Maiellaro, Isabella
T1  - A universal bioluminescence resonance energy transfer sensor design enables high-sensitivity screening of GPCR activation dynamics
JF  - Communications Biology
N2  - G-protein-coupled receptors (GPCRs) represent one of the most important classes of drug targets. The discovery of new GCPR therapeutics would greatly benefit from the development of a generalizable high-throughput assay to directly monitor their activation or de-activation. Here we screened a variety of labels inserted into the third intracellular loop and the C-terminus of the alpha(2 Lambda)-adrenergic receptor and used fluorescence (FRET) and bioluminescence resonance energy transfer (BRET) to monitor ligand-binding and activation dynamics. We then developed a universal intramolecular BRET receptor sensor design to quantify efficacy and potency of GPCR ligands in intact cells and real time. We demonstrate the transferability of the sensor design by cloning beta(2)-adrenergic and PTH1-receptor BRET sensors and monitored their efficacy and potency. For all biosensors, the Z factors were well above 0.5 showing the suitability of such design for microtiter plate assays. This technology will aid the identification of novel types of GPCR ligands.
KW  - Fluorescence resonance energy transfer
KW  - G protein-coupled receptors
KW  - High-throughput screening
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228592
VL  - 1
IS  - 105
ER  - 
TY  - JOUR
A1  - Winkelbeiner, Nicola
A1  - Wandt, Viktoria K.
A1  - Ebert, Franziska
A1  - Lossow, Kristina
A1  - Bankoglu, Ezgi E.
A1  - Martin, Maximilian
A1  - Mangerich, Aswin
A1  - Stopper, Helga
A1  - Bornhorst, Julia
A1  - Kipp, Anna P.
A1  - Schwerdtle, Tanja
T1  - A multi-endpoint approach to base excision repair incision activity augmented by PARylation and DNA damage levels in mice: impact of sex and age
JF  - International Journal of Molecular Sciences
N2  - Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2'-deoxyguanosine (8-oxodG), 5-hydroxy-2'-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.
KW  - maintenance of genomic integrity
KW  - ageing
KW  - sex
KW  - DNA damage
KW  - base excision repair (incision activity)
KW  - DNA damage response
KW  - poly(ADP-ribosyl)ation
KW  - liver
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285706
SN  - 1422-0067
VL  - 21
IS  - 18
ER  - 
TY  - JOUR
A1  - Hommers, L. G.
A1  - Richter, J.
A1  - Yang, Y.
A1  - Raab, A.
A1  - Baumann, C.
A1  - Lang, K.
A1  - Schiele, M. A.
A1  - Weber, H.
A1  - Wittmann, A.
A1  - Wolf, C.
A1  - Alpers, G. W.
A1  - Arolt, V.
A1  - Domschke, K.
A1  - Fehm, L.
A1  - Fydrich, T.
A1  - Gerlach, A.
A1  - Gloster, A. T.
A1  - Hamm, A. O.
A1  - Helbig-Lang, S.
A1  - Kircher, T.
A1  - Lang, T.
A1  - Pané-Farré, C. A.
A1  - Pauli, P.
A1  - Pfleiderer, B.
A1  - Reif, A.
A1  - Romanos, M.
A1  - Straube, B.
A1  - Ströhle, A.
A1  - Wittchen, H.-U.
A1  - Frantz, S.
A1  - Ertl, G.
A1  - Lohse, M. J.
A1  - Lueken, U.
A1  - Deckert, J.
T1  - A functional genetic variation of SLC6A2 repressor hsa-miR-579-3p upregulates sympathetic noradrenergic processes of fear and anxiety
JF  - Translational Psychiatry
N2  - Increased sympathetic noradrenergic signaling is crucially involved in fear and anxiety as defensive states. MicroRNAs regulate dynamic gene expression during synaptic plasticity and genetic variation of microRNAs modulating noradrenaline transporter gene (SLC6A2) expression may thus lead to altered central and peripheral processing of fear and anxiety. In silico prediction of microRNA regulation of SLC6A2 was confirmed by luciferase reporter assays and identified hsa-miR-579-3p as a regulating microRNA. The minor (T)-allele of rs2910931 (MAFcases = 0.431, MAFcontrols = 0.368) upstream of MIR579 was associated with panic disorder in patients (pallelic = 0.004, ncases = 506, ncontrols = 506) and with higher trait anxiety in healthy individuals (pASI = 0.029, pACQ = 0.047, n = 3112). Compared to the major (A)-allele, increased promoter activity was observed in luciferase reporter assays in vitro suggesting more effective MIR579 expression and SLC6A2 repression in vivo (p = 0.041). Healthy individuals carrying at least one (T)-allele showed a brain activation pattern suggesting increased defensive responding and sympathetic noradrenergic activation in midbrain and limbic areas during the extinction of conditioned fear. Panic disorder patients carrying two (T)-alleles showed elevated heart rates in an anxiety-provoking behavioral avoidance test (F(2, 270) = 5.47, p = 0.005). Fine-tuning of noradrenaline homeostasis by a MIR579 genetic variation modulated central and peripheral sympathetic noradrenergic activation during fear processing and anxiety. This study opens new perspectives on the role of microRNAs in the etiopathogenesis of anxiety disorders, particularly their cardiovascular symptoms and comorbidities.
KW  - clinical genetics
KW  - psychiatric disorders
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322497
VL  - 8
ER  - 
TY  - JOUR
A1  - Holler, E.
A1  - Fischer, H.
A1  - Weber, C.
A1  - Stopper, Helga
A1  - Steger, H.
A1  - Simek, H.
T1  - A DNA polymerase with unusual properties from the slime mold Physarum polycephalum
N2  - Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase cx on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzymewas 30-40% pure and form HS2 enzyme 60% with regard toprotein contents of the preparations. Form HS2 enzymewas generated from form HS1 enzyme on prolonged standing of enzyme preparations. The DNA polymerases were obtained as complexes of a 60-kDa protein associated with either a 135-kDa (HS1) or a 110-kDa (HS2) DNA-polymerizing polypeptidein a 1:1 molar stoichiometry. The biochemical function of the 60-kDa protein remained unknown. The complexes tended to dissociate during gradient centrifugation and during partition chromatography as weil as during polyacrylamide gradient gel electrophoresis under nondenaturing conditions at high dilutions of samples. Both forms existed in plasmodia extracts, their proportions depending on several factors including those which promoted proteolysis. The DNA polymerases resembled eucaryotic DNA polymerase ß by several criteria and were functionally indistinguishable from each other. It is suggested that lower eucaryotes contain repair DNA polymerases, which are similar to those of eubacteria on a molecular mass basis.
KW  - Toxikologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63501
ER  - 
TY  - JOUR
A1  - Lutz, Werner K.
A1  - Schlatter, C.
T1  - A closed inhalation system for pharmacokinetic and metabolism studies of volatile compounds with small laboratory animals
N2  - In the inhalation system described an animal can be kept in the same atmosphere of a 2-liter desiccator for up to 24 h. The expired carbon dioxide is adsorbed with soda lime and the resulting reduced pressure is balanced by a supply of oxygen also used for the inflow of the chemical to be investigated. Urine and faeces can be collected ~eparately and the system allows a periodical control of the concentration of the chemical by sampling the air with needle and syringe.
KW  - Toxikologie
Y1  - 1978
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80145
ER  - 
TY  - JOUR
A1  - Bommakanti, R. K.
A1  - Klotz, Karl-Norbert
A1  - Dratz, E. A.
A1  - Jesaitis, A. J.
T1  - A carboxyl-terminal tail peptide of neutrophil chemotactic receptor disrupts its physical complex with G protein
N2  - No abstract available
KW  - Toxikologie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60456
ER  - 
TY  - THES
A1  - Curtaz, Carolin Julia
T1  - \(In\) \(vitro\) Analysen der Wechselwirkung erhöhter Temperatur mit Zytostatika am Beispiel von Cisplatin
T1  - \(In\) \(vitro\) analysis of the interaction of hyperthermia with cytostatica in case of cisplatin
N2  - Neben der Chemotherapie ist heutzutage auch die Hyperthermie-Behandlung eine wichtige Säule der antitumorösen Therapie. Während der sogenannten HIPEC Therapie (Hypertherme intraperitoneale Chemoperfusion) werden die beiden Arten der Therapieformen kombiniert und in der klinischen Praxis erfolgreich angewendet. Genauere Kenntnisse über die zu Grunde liegenden toxikologischen in-vitro Mechanismen könnten zu neuen Möglichkeiten in der klinischen Anwendung führen. In unserer Arbeit untersuchten wir verschiedenen Tumorzelllinien (HT29,CaCo-2,HCT116,HaCaT) in Kombination mit Cisplatin und Hyperthermie mit verschiedenen Methoden, wie zum Beispiel Mikrokerntest, Comet-Assay, Durchflusszytometrie, Vitalitätstest und mikroskopischen Analysen. Unsere Ergebnisse führten uns zu der Hypothese, dass Hyperthermie alleine zu einer sogenannte mitotic catastrophe führt und zum Absterben der Tumorzellen. Im Gegensatz dazu zeigten Tumorzellen, welche mit Cisplatin alleine oder auch in Kombination mit Hyperthermie nicht in die Mitose eintreten und daher nicht durch Apoptose in den Zelltod gehen.
N2  - Nowadays the use of chemotherapy, but also hyperthermia are main columns of the anti- cancer treatment. In the so-called HIPEC therapy (hypertherme intraperitoneale chemoperfusion) these both kinds of treatments are combined and successfully applieded with clinical relevance. More detailed knowledge about the underlying in-vitro toxicological mechanism may lead to new opportunities in the clinical practice. In our work we examined different cancer cells (HT29, CaCo2,HCT116,HaCaT) in the combination of with cisplatin and hyperthermia by using different methods e.g. micronucleus test, comet-assay, flow cytometry, vitality test and microscopical analysis. Our aquired results lead to the postulation that hyperthermia alone induces a so- called mitotic catastrophe provoking the death of tumor cells. However tumor cells treated with cisplatin with or without combination with hyperthermia do not enter into mitosis and therefore cannot undergo apoptosis through a mitotic catastrophe.
KW  - Hyperthermie
KW  - cisplatin
KW  - HIPEC therapy
KW  - mitotic catastrophe
KW  - comet assay
KW  - micronucleus test
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174543
ER  - 
TY  - JOUR
A1  - Lohse, M. J.
A1  - Klotz, Karl-Norbert
A1  - Lindenborn Fotinos, J.
A1  - Reddington, M.
A1  - Schwabe, U.
A1  - Olsson, R. A.
T1  - 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) - a selective high affinity antagonist radioligand for A\(_1\) adenosine receptors
N2  - The properties of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) as an antagonist ligand for A\(_1\) adenosirre receptors were examined and conipared with other radioligands for this receptor. DPCPX competitively antagonized both the inhibition of adenylate cyclase activity via A\(_1\) adenosirre receptors and the stimulationvia A\(_2\) adenosirre receptors. The K\(_i\)-values of this antagonism were 0.45 nM at the A\(_1\) receptor of rat fat cells, and 330 nM at the A\(_2\) receptor of human platelets, giving a more than 700-fold A\(_1\)-selectivity. A similar A\(_1\)-selectivity was determined in radioligand binding studies. Even at high concentrations, DPCPX did not significantly inhibit the soluble cAMPphosphodiesterase activity of human platelets. [\(^3\)H]DPCPX (105 Ci/mmol) bound in a saturable manner with high affinity to A\(_1\) receptors in membranes of bovine brain and heart, and rat brain and fat cells (K\(_D\) -values 50-190 pM). Its nonspecific binding was about 1% of total at K\(_D\) , except in bovine myocardial membranes (about 10%). Binding studies with bovine myocardial membranes allowed the analysis of both the high and low agonist affinity states of this receptor in a tissue with low receptor density. The binding properties of [\(^3\)H]DPCPX appear superior to those of other agonist and antagonist radioligands for the A\(_1\) receptor.
KW  - Toxikologie
KW  - Adenosine receptors
KW  - Adenylate cyclase
KW  - Phosphodiesterase
KW  - Xanthines
KW  - Radioligands
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60246
ER  - 
TY  - JOUR
A1  - Grunicke, H.
A1  - Pyerin, W.
A1  - Eisenbrand, G.
A1  - Havemann, K.
A1  - Rabes, H. M.
A1  - Molling, K.
A1  - Schwab, M.
A1  - Lutz, Werner K.
A1  - Wahrendorf, J.
A1  - Schirrmacher, V.
T1  - 7th International Symposium of the Division of Experimental Cancer Research (AEK) of the German Cancer Society : [Meeting report]
N2  - No abstract available
KW  - Toxikologie
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60651
ER  - 
TY  - INPR
A1  - Brenner, Marian
A1  - Zink, Christoph
A1  - Witzinger, Linda
A1  - Keller, Angelika
A1  - Hadamek, Kerstin
A1  - Bothe, Sebastian
A1  - Neuenschwander, Martin
A1  - Villmann, Carmen
A1  - von Kries, Jens Peter
A1  - Schindelin, Hermann
A1  - Jeanclos, Elisabeth
A1  - Gohla, Antje
T1  - 7,8-Dihydroxyflavone is a direct inhibitor of pyridoxal phosphatase
T2  - eLife
N2  - Vitamin B6 deficiency has been linked to cognitive impairment in human brain disorders for decades. Still, the molecular mechanisms linking vitamin B6 to these pathologies remain poorly understood, and whether vitamin B6 supplementation improves cognition is unclear as well. Pyridoxal phosphatase (PDXP), an enzyme that controls levels of pyridoxal 5’-phosphate (PLP), the co-enzymatically active form of vitamin B6, may represent an alternative therapeutic entry point into vitamin B6-associated pathologies. However, pharmacological PDXP inhibitors to test this concept are lacking. We now identify a PDXP and age-dependent decline of PLP levels in the murine hippocampus that provides a rationale for the development of PDXP inhibitors. Using a combination of small molecule screening, protein crystallography and biolayer interferometry, we discover and analyze 7,8-dihydroxyflavone (7,8-DHF) as a direct and potent PDXP inhibitor. 7,8-DHF binds and reversibly inhibits PDXP with low micromolar affinity and sub-micromolar potency. In mouse hippocampal neurons, 7,8-DHF increases PLP in a PDXP-dependent manner. These findings validate PDXP as a druggable target. Of note, 7,8-DHF is a well-studied molecule in brain disorder models, although its mechanism of action is actively debated. Our discovery of 7,8-DHF as a PDXP inhibitor offers novel mechanistic insights into the controversy surrounding 7,8-DHF-mediated effects in the brain.
KW  - 7,8-dihydroxyflavone (7,8-DHF)
KW  - pyridoxal phosphatase (PDXP)
KW  - vitamin B6
KW  - PDXP inhibitors
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350446
ER  -