Publikationen

2022
Yin, H. ; Karayel, O. ; Chao, Y.Y. ; Seeholzer, T. ; Hamp, I. ; Plettenburg, O. ; Gehring, T. ; Zielinski, C. ; Mann, M. ; Krappmann, D.
Cell. Mol. Life Sci. 79:112 (2022)
T cell activation initiates protective adaptive immunity, but counterbalancing mechanisms are critical to prevent overshooting responses and to maintain immune homeostasis. The CARD11-BCL10-MALT1 (CBM) complex bridges T cell receptor engagement to NF-κB signaling and MALT1 protease activation. Here, we show that ABIN-1 is modulating the suppressive function of A20 in T cells. Using quantitative mass spectrometry, we identified ABIN-1 as an interactor of the CBM signalosome in activated T cells. A20 and ABIN-1 counteract inducible activation of human primary CD4 and Jurkat T cells. While A20 overexpression is able to silence CBM complex-triggered NF-κB and MALT1 protease activation independent of ABIN-1, the negative regulatory function of ABIN-1 depends on A20. The suppressive function of A20 in T cells relies on ubiquitin binding through the C-terminal zinc finger (ZnF)4/7 motifs, but does not involve the deubiquitinating activity of the OTU domain. Our mechanistic studies reveal that the A20/ABIN-1 module is recruited to the CBM complex via A20 ZnF4/7 and that proteasomal degradation of A20 and ABIN-1 releases the CBM complex from the negative impact of both regulators. Ubiquitin binding to A20 ZnF4/7 promotes destructive K48-polyubiquitination to itself and to ABIN-1. Further, after prolonged T cell stimulation, ABIN-1 antagonizes MALT1-catalyzed cleavage of re-synthesized A20 and thereby diminishes sustained CBM complex signaling. Taken together, interdependent post-translational mechanisms are tightly controlling expression and activity of the A20/ABIN-1 silencing module and the cooperative action of both negative regulators is critical to balance CBM complex signaling and T cell activation.
Wissenschaftlicher Artikel
Scientific Article
Napolitano, V. ; Dabrowska, A. ; Schorpp, K.K. ; Mourao, A. ; Barreto-Duran, E. ; Benedyk, M. ; Botwina, P. ; Brandner, S. ; Bostock, M.J. ; Chykunova, Y. ; Czarna, A. ; Dubin, G. ; Fröhlich, T. ; Hölscher, M. ; Jedrysik, M. ; Matsuda, A. ; Owczarek, K. ; Pachota, M. ; Plettenburg, O. ; Potempa, J.S. ; Rothenaigner, I. ; Schlauderer, F. ; Slysz, K. ; Szczepanski, A. ; Greve-Isdahl Mohn, K. ; Blomberg, B. ; Sattler, M. ; Hadian, K. ; Popowicz, G.M. ; Pyrc, K.
Cell Chem. Bio. 29, 774-784.e8 (2022)
The COVID-19 pandemic caused by SARS-CoV-2 has been socially and economically devastating. Despite an unprecedented research effort and available vaccines, effective therapeutics are still missing to limit severe disease and mortality. Using high-throughput screening, we identify acriflavine (ACF) as a potent papain-like protease (PLpro) inhibitor. NMR titrations and a co-crystal structure confirm that acriflavine blocks the PLpro catalytic pocket in an unexpected binding mode. We show that the drug inhibits viral replication at nanomolar concentration in cellular models, in vivo in mice and ex vivo in human airway epithelia, with broad range activity against SARS-CoV-2 and other betacoronaviruses. Considering that acriflavine is an inexpensive drug approved in some countries, it may be immediately tested in clinical trials and play an important role during the current pandemic and future outbreaks.
Wissenschaftlicher Artikel
Scientific Article
2021
Liu, N. ; O'Connor, P. ; Gujrati, V. ; Gorpas, D. ; Glasl, S. ; Blutke, A. ; Walch, A.K. ; Kleigrewe, K. ; Sattler, M. ; Plettenburg, O. ; Ntziachristos, V.
In: (European Conference on Biomedical Optics, 20–24 June 2021, Munich Germany). 2021. DOI: 10.1117/12.2615998 ( ; 11923)
CR760, a croconaine dye with excellent optical properties, was synthesized in a single step and subsequently nano-formulated for optoacoustic imaging and photothermal therapy of cancer.
Gerckens, M. ; Schorpp, K.K. ; Pelizza, F. ; Wögrath, M. ; Reichau, K. ; Ma, H. ; Dworsky, A.-M. ; Sengupta, A. ; Stoleriu, M.-G. ; Heinzelmann, K. ; Merl-Pham, J. ; Irmler, M. ; Alsafadi, H.N. ; Trenkenschuh, E. ; Sarnova, L. ; Jirouskova, M. ; Frieß, W. ; Hauck, S.M. ; Beckers, J. ; Kneidinger, N. ; Behr, J. ; Hilgendorff, A. ; Hadian, K. ; Lindner, M. ; Königshoff, M. ; Eickelberg, O. ; Gregor, M. ; Plettenburg, O. ; Yildirim, A.Ö. ; Burgstaller, G.
Sci. Adv. 7:eabb3673 (2021)
Fibrogenic processes instigate fatal chronic diseases leading to organ failure and death. Underlying biological processes involve induced massive deposition of extracellular matrix (ECM) by aberrant fibroblasts. We subjected diseased primary human lung fibroblasts to an advanced three-dimensional phenotypic high-content assay and screened a repurposing drug library of small molecules for inhibiting ECM deposition. Fibrotic Pattern Detection by Artificial Intelligence identified tranilast as an effective inhibitor. Structure-activity relationship studies confirmed N-(2-butoxyphenyl)-3-(phenyl)acrylamides (N23Ps) as a novel and highly potent compound class. N23Ps suppressed myofibroblast transdifferentiation, ECM deposition, cellular contractility, and altered cell shapes, thus advocating a unique mode of action. Mechanistically, transcriptomics identified SMURF2 as a potential therapeutic target network. Antifibrotic activity of N23Ps was verified by proteomics in a human ex vivo tissue fibrosis disease model, suppressing profibrotic markers SERPINE1 and CXCL8. Conclusively, N23Ps are a novel class of highly potent compounds inhibiting organ fibrosis in patients.
Wissenschaftlicher Artikel
Scientific Article
Fino, R. ; Lenhart, D. ; Kalel, V.C. ; Softley, C. ; Napolitano, V. ; Byrne, R. ; Schliebs, W. ; Dawidowski, M. ; Erdmann, R. ; Sattler, M. ; Schneider, G. ; Plettenburg, O. ; Popowicz, G.M.
J. Chem. Inf. Model. 61, 5256-5268 (2021)
African and American trypanosomiases are estimated to affect several million people across the world, with effective treatments distinctly lacking. New, ideally oral, treatments with higher efficacy against these diseases are desperately needed. Peroxisomal import matrix (PEX) proteins represent a very interesting target for structure- and ligand-based drug design. The PEX5-PEX14 protein-protein interface in particular has been highlighted as a target, with inhibitors shown to disrupt essential cell processes in trypanosomes, leading to cell death. In this work, we present a drug development campaign that utilizes the synergy between structural biology, computer-aided drug design, and medicinal chemistry in the quest to discover and develop new potential compounds to treat trypanosomiasis by targeting the PEX14-PEX5 interaction. Using the structure of the known lead compounds discovered by Dawidowski et al. as the template for a chemically advanced template search (CATS) algorithm, we performed scaffold-hopping to obtain a new class of compounds with trypanocidal activity, based on 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines chemistry. The initial compounds obtained were taken forward to a first round of hit-to-lead optimization by synthesis of derivatives, which show activities in the range of low- to high-digit micromolar IC50 in the in vitro tests. The NMR measurements confirm binding to PEX14 in solution, while immunofluorescent microscopy indicates disruption of protein import into the glycosomes, indicating that the PEX14-PEX5 protein-protein interface was successfully disrupted. These studies result in development of a novel scaffold for future lead optimization, while ADME testing gives an indication of further areas of improvement in the path from lead molecules toward a new drug active against trypanosomes.
Wissenschaftlicher Artikel
Scientific Article
Hamp, I. ; O'Neill, T.J. ; Plettenburg, O. ; Krappmann, D.
Expert Opin. Ther. Patents, DOI: 10.1080/13543776.2021.1951703 (2021)
INTRODUCTION: MALT1 is the only human paracaspase, a protease with unique cleavage activity and substrate specificity. As a key regulator of immune responses, MALT1 has attracted attention as an immune modulatory target for the treatment of autoimmune/inflammatory diseases. Further, chronic MALT1 protease activation drives survival of lymphomas, suggesting that MALT1 is a suitable drug target in lymphoid malignancies. Recent studies have indicated that MALT1 inhibition impairs immune suppressive function of regulatory T cells in the tumor microenvironment, suggesting that MALT1 inhibitors may boost anti-tumor immunity in the treatment of solid cancers. AREAS COVERED: : This review summarizes the literature on MALT1 patents and applications. We discuss the potential therapeutic uses for MALT1 inhibitors based on patents and scientific literature. EXPERT OPINION: : There has been a steep increase in MALT1 inhibitor patents. Compounds with high selectivity and good bioavailability have been developed. An allosteric binding pocket is the preferred site for potent and selective MALT1 targeting. MALT1 inhibitors have moved to early clinical trials, but toxicological studies indicate that long-term MALT1 inhibition can disrupt immune homeostasis and lead to autoimmunity. Even though this poses risks, preventing immune suppression may favor the use of MALT1 inhibitors in cancer immunotherapies.
Review
Review
Rai, A. ; Klare, J.P. ; Reinke, P.Y.A. ; Englmaier, F. ; Fohrer, J. ; Fedorov, R. ; Taft, M.H. ; Chizhov, I. ; Curth, U. ; Plettenburg, O. ; Manstein, D.J.
Int. J. Mol. Sci. 22:6265 (2021)
A novel cytoplasmic dye-decolorizing peroxidase from Dictyostelium discoideum was investi-gated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such as ABTS efficiently. Unlike related enzymes, an aspartate residue replaces the first glycine of the conserved GXXDG motif in Dictyostelium DyPA. In solution, Dictyostelium DyPA exists as a stable dimer with the side chain of Asp146 contributing to the stabilization of the dimer interface by extending the hydrogen bond network connecting two monomers. To gain mechanistic insights, we solved the Dicty-ostelium DyPA structures in the absence of substrate as well as in the presence of potassium cyanide and veratryl alcohol to 1.7, 1.85, and 1.6 Å resolution, respectively. The active site of Dictyostelium DyPA has a hexa-coordinated heme iron with a histidine residue at the proximal axial position and either an acti-vated oxygen or CN− molecule at the distal axial position. Asp149 is in an optimal conformation to accept a proton from H2O2 during the formation of compound I. Two potential distal solvent channels and a conserved shallow pocket leading to the heme molecule were found in Dictyostelium DyPA. Further, we identified two substrate-binding pockets per monomer in Dictyostelium DyPA at the dimer interface. Long-range electron transfer pathways associated with a hydrogen-bonding network that connects the substrate-binding sites with the heme moiety are described.
Wissenschaftlicher Artikel
Scientific Article
Hofmeister, A. ; Jahn-Hofmann, K. ; Brunner, B. ; Helms, M.W. ; Metz-Weidmann, C. ; Krack, A. ; Kurz, M. ; Li, Z. ; Weitzenberg, M.M. ; Pflimlin, E. ; Plettenburg, O. ; Scheidler, S.
J. Med. Chem. 64, 6838–6855 (2021)
A morpholine-based nucleotide analog was developed as a building block for hepatic siRNA targeting and stabilization. Attachment of an asialoglycoprotein-binding GalNAc ligand at the morpholine nitrogen was realized with different linkers. The obtained morpholino GalNAc scaffolds were coupled to the sense strand of a transthyretin-targeting siRNA and tested for their knockdown potency in vitro and in vivo. A clear structure-activity relationship was developed with regard to the linker type and length as well as the attachment site of the morpholino GalNAc moieties at the siRNA sense strand. Further, simple alkylation of the morpholine nitrogen led to a nucleotide analog, which increased siRNA stability, when used as a double 3'-overhang at the sense strand sequence. Combination of the best morpholino GalNAc building blocks as targeting nucleotides with an optimized stabilizing alkyl-substituted morpholine as 3'-overhangs resulted in siRNAs without any phosphorothioate stabilization in the sense strand and clearly improved the duration of action in vivo.
Wissenschaftlicher Artikel
Scientific Article
Liu, N. ; O'Connor, P. ; Gujrati, V. ; Gorpas, D. ; Glasl, S. ; Blutke, A. ; Walch, A.K. ; Kleigrewe, K. ; Sattler, M. ; Plettenburg, O. ; Ntziachristos, V.
Adv. Healthc. Mater. 10:e2002115 (2021)
Near-infrared (NIR) light absorbing theranostic agents can integrate optoacoustic imaging and photothermal therapy for effective personalized precision medicine. However, most of these agents face the challenges of unstable optical properties, material-associated toxicity, and nonbiodegradability, all of which limit their biomedical application. Several croconaine-based organic agents able to overcome some of these limitations have been recently reported, but these suffer from complicated multistep synthesis protocols. Herein, the use of CR760, a croconaine dye with excellent optical properties, is reported for nanoparticle formulation and subsequent optoacoustic imaging and photothermal therapy. Importantly, CR760 can be conveniently prepared in a single step from commercially available materials. Furthermore, CR760 can be covalently attached, via a polyethylene glycol linker, to the αvβ3 integrin ligand c(RGDyC), resulting in self-assembled nanoparticles (NPs) with cancer-targeting capability. Such CR760RGD-NPs exhibit strong NIR absorption, high photostability, high optoacoustic generation efficiency, and active tumor-targeting, making them ideal candidates for optoacoustic imaging. Due to favorable electron transfer, CR760RGD-NPs display a 45.37% photothermal conversion efficiency thereby rendering them additionally useful for photothermal therapy. Targeted tumor elimination, biosafety, and biocompatibility are demonstrated in a 4T1 murine breast tumor model. This work points to the use of CR760RGD-NPs as a promising nanoagent for NIR-based cancer phototheranostics.
Wissenschaftlicher Artikel
Scientific Article
Ansarullah ; Jain, C. ; Far, F.F. ; Homberg, S. ; Wißmiller, K. ; von Hahn, F. ; Raducanu, A. ; Schirge, S. ; Sterr, M. ; Bilekova, S. ; Siehler, J. ; Wiener, J. ; Oppenländer, L. ; Morshedi, A. ; Bastidas-Ponce, A. ; Collden, G. ; Irmler, M. ; Beckers, J. ; Feuchtinger, A. ; Grzybek, M. ; Ahlbrecht, C. ; Feederle, R. ; Plettenburg, O. ; Müller, T.D. ; Meier, M. ; Tschöp, M.H. ; Coskun, Ü. ; Lickert, H.
Nature 592:E1 (2021)
In this Article, the affiliations for author Ünal Coskun were incorrect. They should be ‘German Center for Diabetes Research (DZD), Neuherberg, Germany’, ‘Paul Langerhans Institute Dresden of Helmholtz Center Munich, Technical University Dresden, Dresden, Germany’ and ‘Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Clinic Carl Gustav Carus, Technical University Dresden, Dresden, Germany’ (affiliations 2, 10 and 14, respectively), and not ‘Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany’ (affiliation 5). The original Article has been corrected online.
Eriksson, O. ; Velikyan, I. ; Haack, T. ; Bossart, M. ; Evers, A. ; Lorenz, K. ; Laitinen, I. ; Larsen, P.J. ; Plettenburg, O. ; Johansson, L. ; Pierrou, S. ; Wagner, M.
Diabetes 70, 842-853 (2021)
Targeting of the Glucose-dependent Insulinotropic Polypeptide receptor GIPR is an emerging strategy in anti-diabetic drug development. The aim of this study was to develop a Positron Emission Tomography (PET) radioligand for the GIPR, to enable the assessment of target distribution and drug target engagement in vivo.The GIPR selective peptide S02-GIP was radiolabeled with Gallium-68. The resulting PET tracer [68Ga]S02-GIP-T4 was evaluated for affinity and specificity to human GIPR (huGIPR). The in vivo GIPR binding of [68Ga]S02-GIP-T4, as well as the occupancy of a drug candidate with GIPR activity, was assessed in non-human primates (NHP) by PET.[68Ga]S02-GIP-T4 bound with nanomolar affinity and high selectivity to huGIPR in overexpressing cells. In vivo pancreatic binding in NHP could be dose dependently inhibited by co-injection of unlabelled S02-GIP-T4. Finally, subcutaneous pre-treatment with a high dose of a drug candidate with GIPR activity led to a decreased pancreatic binding of [68Ga]S02-GIP-T4, corresponding to a GIPR drug occupancy of almost 90%. [68Ga]S02-GIP-T4 demonstrated a safe dosimetric profile, allowing for repeated studies in humans. In conclusion, [68Ga]S02-GIP-T4 is a novel PET biomarker for safe, non-invasive, and quantitative assessment of GIPR target distribution and drug occupancy.
Wissenschaftlicher Artikel
Scientific Article
Ansarullah ; Jain, C. ; Far, F.F. ; Homberg, S. ; Wissmiller, K. ; Gräfin von Hahn, F. ; Raducanu, A. ; Schirge, S. ; Sterr, M. ; Bilekova, S. ; Siehler, J. ; Wiener, J. ; Oppenländer, L. ; Morshedi, A. ; Bastidas-Ponce, A. ; Collden, G. ; Irmler, M. ; Beckers, J. ; Feuchtinger, A. ; Grzybek, M. ; Ahlbrecht, C. ; Feederle, R. ; Plettenburg, O. ; Müller, T.D. ; Meier, M. ; Tschöp, M.H. ; Coskun, Ü. ; Lickert, H.
Nature 590, 326–331 (2021)
Resistance to insulin and insulin-like growth factor 1 (IGF1) in pancreatic β-cells causes overt diabetes in mice; thus, therapies that sensitize β-cells to insulin may protect patients with diabetes against β-cell failure1–3. Here we identify an inhibitor of insulin receptor (INSR) and IGF1 receptor (IGF1R) signalling in mouse β-cells, which we name the insulin inhibitory receptor (inceptor; encoded by the gene Iir). Inceptor contains an extracellular cysteine-rich domain with similarities to INSR and IGF1R4, and a mannose 6-phosphate receptor domain that is also found in the IGF2 receptor (IGF2R)5. Knockout mice that lack inceptor (Iir−/−) exhibit signs of hyperinsulinaemia and hypoglycaemia, and die within a few hours of birth. Molecular and cellular analyses of embryonic and postnatal pancreases from Iir−/− mice showed an increase in the activation of INSR–IGF1R in Iir−/− pancreatic tissue, resulting in an increase in the proliferation and mass of β-cells. Similarly, inducible β-cell-specific Iir−/− knockout in adult mice and in ex vivo islets led to an increase in the activation of INSR–IGF1R and increased proliferation of β-cells, resulting in improved glucose tolerance in vivo. Mechanistically, inceptor interacts with INSR–IGF1R to facilitate clathrin-mediated endocytosis for receptor desensitization. Blocking this physical interaction using monoclonal antibodies against the extracellular domain of inceptor resulted in the retention of inceptor and INSR at the plasma membrane to sustain the activation of INSR–IGF1R in β-cells. Together, our findings show that inceptor shields insulin-producing β-cells from constitutive pathway activation, and identify inceptor as a potential molecular target for INSR–IGF1R sensitization and diabetes therapy.
Wissenschaftlicher Artikel
Scientific Article
Hartleben, G. ; Schorpp, K.K. ; Kwon, Y. ; Betz, B. ; Tsokanos, F.-F. ; Dantes, Z. ; Schäfer, A. ; Rothenaigner, I. ; Monroy Kuhn, J.M. ; Morigny, P. ; Mehr, L. ; Lin, S. ; Seitz, S. ; Tokarz, J. ; Artati, A. ; Adamski, J. ; Plettenburg, O. ; Lutter, D. ; Irmler, M. ; Beckers, J. ; Reichert, M. ; Hadian, K. ; Zeigerer, A. ; Herzig, S. ; Berriel Diaz, M.
EMBO Mol. Med.:e12461 (2021)
By accentuating drug efficacy and impeding resistance mechanisms, combinatorial, multi-agent therapies have emerged as key approaches in the treatment of complex diseases, most notably cancer. Using high-throughput drug screens, we uncovered distinct metabolic vulnerabilities and thereby identified drug combinations synergistically causing a starvation-like lethal catabolic response in tumor cells from different cancer entities. Domperidone, a dopamine receptor antagonist, as well as several tricyclic antidepressants (TCAs), including imipramine, induced cancer cell death in combination with the mitochondrial uncoupler niclosamide ethanolamine (NEN) through activation of the integrated stress response pathway and the catabolic CLEAR network. Using transcriptome and metabolome analyses, we characterized a combinatorial response, mainly driven by the transcription factors CHOP and TFE3, which resulted in cell death through enhanced pyrimidine catabolism as well as reduced pyrimidine synthesis. Remarkably, the drug combinations sensitized human organoid cultures to the standard-of-care chemotherapy paclitaxel. Thus, our combinatorial approach could be clinically implemented into established treatment regimen, which would be further facilitated by the advantages of drug repurposing.
Wissenschaftlicher Artikel
Scientific Article
2020
Dawidowski, M. ; Kalel, V.C. ; Napolitano, V. ; Fino, R. ; Schorpp, K.K. ; Emmanouilidis, L. ; Lenhart, D. ; Ostertag, M.S. ; Kaiser, M. ; Kolonko, M. ; Tippler, B. ; Schliebs, W. ; Dubin, G. ; Mäser, P. ; Tetko, I.V. ; Hadian, K. ; Plettenburg, O. ; Erdmann, R. ; Sattler, M. ; Popowicz, G.M.
J. Med. Chem. 63, 847-879 (2020)
Trypanosoma protists are pathogens leading to a spectrum of devastating infectious diseases. The range of available chemotherapeutics against Trypanosoma is limited, and the existing therapies are partially ineffective and cause serious adverse effects. Formation of the PEX14-PEX5 complex is essential for protein import into the parasites' glycosomes. This transport is critical for parasite metabolism and failure leads to mislocalization of glycosomal enzymes, with fatal consequences for the parasite. Hence, inhibiting the PEX14-PEX5 protein protein interaction (PPI) is an attractive way to affect multiple metabolic pathways. Herein, we have used structure-guided computational screening and optimization to develop the first line of compounds that inhibit PEX14-PEX5 PPI. The optimization was driven by several X-ray structures, NMR binding data, and molecular dynamics simulations. Importantly, the developed compounds show significant cellular activity against Trypanosoma, including the human pathogen Trypanosoma brucei gambiense and Trypanosoma cruzi parasites.
Wissenschaftlicher Artikel
Scientific Article
2019
Laitinen, I. ; Jones, S. ; Derdau, V. ; Eriksson, O. ; Haack, T.B. ; Johansson, L. ; Larsen, P. ; Loewe, C. ; Pierrou, S. ; Plettenburg, O. ; Schudok, M. ; Velikyan, I. ; Wagner, M.
Eur. J. Nucl. Med. Mol. Imaging 46, S707-S708 (2019)
Meeting abstract
Meeting abstract
Eriksson, O. ; Velikyan, I. ; Haack, T. ; Bossart, M. ; Evers, A. ; Laitinen, I. ; Larsen, P.J. ; Plettenburg, O. ; Takano, A. ; Halldin, C. ; Antoni, G. ; Johansson, L. ; Pierrou, S. ; Wagner, M.
Sci. Rep. 9:14960 (2019)
The glucagon receptor (GCGR) is an emerging target in anti-diabetic therapy. Reliable biomarkers for in vivo activity on the GCGR, in the setting of dual glucagon-like peptide 1/glucagon (GLP-1/GCG) receptor agonism, are currently unavailable. Here, we investigated [Ga-68]Ga-DO3A-S01-GCG as a biomarker for GCGR occupancy in liver, the tissue with highest GCGR expression, in non-human primates (NHP) by PET. [Ga-68]Ga-DO3A-S01-GCG was evaluated by dynamic PET in NHPs by a dose escalation study design, where up to 67 mu g/kg DO3A-S01-GCG peptide mass was co-injected. The test-retest reproducibility of [Ga-68]Ga-DO3A-S01-GCG binding in liver was evaluated. Furthermore, we investigated the effect of pre-treatment with acylated glucagon agonist 1-GCG on [Ga-68]GaDO3A-S01-GCG binding in liver. [Ga-68]Ga-DO3A-S01-GCG bound to liver in vivo in a dose-dependent manner. Negligible peptide mass effect was observed for DO3A-S01-GCG doses <0.2 mu g/kg. In vivo K-d for [Ga-68]Ga-DO3A-S01-GCG corresponded to 0.7 mu g/kg, which indicates high potency. The test-retest reproducibility for [Ga-68]Ga-DO3A-S01-GCG binding in liver was 5.7 +/- 7.9%. Pre-treatment with 1-GCG, an acylated glucagon agonist, resulted in a GCGR occupancy of 61.5 +/- 9.1% in liver. Predicted human radiation dosimetry would allow for repeated annual [Ga-68]Ga-DO3A-S01-GCG PET examinations. In summary, PET radioligand [Ga-68]Ga-DO3A-S01-GCG is a quantitative biomarker of in vivo GCGR occupancy.
Wissenschaftlicher Artikel
Scientific Article
Kniggendorf, A.K. ; Schmidt, D. ; Roth, B. ; Plettenburg, O. ; Zeilinger, C.
Int. J. Mol. Sci. 20:2736 (2019)
KcsA is a tetrameric potassium channel formed out of four identical monomeric subunits used as a standard model for selective potassium transport and pH-dependent gating. Large conformational changes are reported for tetramer and monomer upon gating, and the response of the monomer being controversial with the two major studies partially contradicting each other. KcsA was analyzed as functional tetramers embedded in liposomes and as monomer subunits with confocal Raman microscopy under physiological conditions for the active and the closed channel state, using 532 nm excitation to avoid introducing conformational changes during the measurement. Channel function was confirmed using liposome flux assay. While the classic fingerprint region below 1800 rel. cm(-1) in the Raman spectrum of the tetramer was unaffected, the CH-stretching region between 2800 and 3200 rel. cm(-1) was found to be strongly affected by the conformation. No pH-dependency was observed in the Raman spectra of the monomer subunits, which closely resembled the Raman spectrum of the tetramer in its active conformation, indicating that the open conformation of the monomer and not the closed conformation as postulated may equal the relaxed state of the molecule.
Wissenschaftlicher Artikel
Scientific Article
Ostertag, M.S. ; Hutwelker, W. ; Plettenburg, O. ; Sattler, M. ; Popowicz, G.M.
J. Mol. Biol. 431, 2213-2221 (2019)
BET proteins such as BRD3 are oncogenic transcriptional coactivators. SPOP binding triggers their proteasomal degradation. In both endometrial and prostate cancers, SPOP mutations occur in the MATH domain, but with opposed influence on drug susceptibility. In prostate cancer, SPOP mutations presumably cause increased BET levels, decreasing BET inhibitor drug susceptibility. As opposed, in endometrial cancer, decreased BET levels concomitant with higher BET inhibitor drug susceptibility were observed. Here, we present the to our knowledge first co-crystal structure of SPOP and a bromodomain containing protein (BRD3). Our structural and biophysical data confirm the suggested loss-of-function in prostate cancer-associated SPOP mutants and provide mechanistic explanation. As opposed to previous literature, our data on endometrial cancer-associated SPOP mutants do not show altered binding behavior compared to wild-type SPOP, indicating a more complex regulatory mechanism. SPOP mutation screening may thus be considered a valuable personalized medicine tool for effective antitumor therapy. (C) 2019 Elsevier Ltd. All rights reserved.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O.
Isr. J. Chem. 59, 29-36 (2019)
In early times, the drug discovery process was mainly based on profiling of new medications in in vivo systems. In the absence of knowledge on enzymatic structures, biochemical signaling or precise cellular processes, researchers were dependent on knowledgeable readout of phenotypic effects in living animals.
Review
Review
Velikyan, I. ; Haack, T. ; Bossart, M. ; Evers, A. ; Laitinen, I. ; Larsen, P. ; Plettenburg, O. ; Johansson, L. ; Pierrou, S. ; Wagner, M. ; Eriksson, O.
EJNMMI Res. 9:17 (2019)
The glucagon receptor (GCGR) is emerging as an important target in anti-diabetic therapy, especially as part of the pharmacology of dual glucagon-like peptide-1/glucagon (GLP-1/GCG) receptor agonists. However, currently, there are no suitable biomarkers that reliably demonstrate GCG receptor target engagement.MethodsTwo potent GCG receptor peptide agonists, S01-GCG and S02-GCG, were labeled with positron emission tomography (PET) radionuclide gallium-68. The GCG receptor binding affinity and specificity of the resulting radiopharmaceuticals [Ga-68]Ga-DO3A-S01-GCG and [Ga-68]Ga-DO3A-S02-GCG were evaluated in HEK-293 cells overexpressing the human GCG receptor and on frozen hepatic sections from human, non-human primate, and rat. In in vivo biodistribution, binding specificity and dosimetry were assessed in rat.Results[Ga-68]Ga-DO3A-S01-GCG in particular demonstrated GCG receptor-mediated binding in cells and liver tissue with affinity in the nanomolar range required for imaging. [Ga-68]Ga-DO3A-S01-GCG binding was not blocked by co-incubation of a GLP-1 agonist. In vivo binding in rat liver was GCG receptor specific with low non-specific binding throughout the body. Moreover, the extrapolated human effective doses, predicted from rat biodistribution data, allow for repeated PET imaging potentially also in combination with GLP-1R radiopharmaceuticals.Conclusion[Ga-68]Ga-DO3A-S01-GCG thus constitutes a first-in-class PET tracer targeting the GCG receptor, with suitable properties for clinical development. This tool has potential to provide direct quantitative evidence of GCG receptor occupancy in humans.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O.
ChemBioChem 20, 129-130 (2019)
Chi-Huey Wong turned 70 in August 2018: This special issue is dedicated to that event. It can be seen from the variety of topics covered that he influenced the thinking of many of his former co-workers, who then transformed and developed these thoughts into fascinating, creative and independent research areas, enriching the science of bioorganic chemistry.
Editorial
Editorial
2018
Kyriakou, E. ; Schmidt, S. ; Dodd, G.T. ; Pfuhlmann, K. ; Simonds, S.E. ; Lenhart, D. ; Geerlof, A. ; Schriever, S.C. ; de Angelis, M. ; Schramm, K.-W. ; Plettenburg, O. ; Cowley, M.A. ; Tiganis, T. ; Tschöp, M.H. ; Pfluger, P.T. ; Sattler, M. ; Messias, A.C.
J. Med. Chem. 61, 11144-11157 (2018)
Celastrol is a natural pentacyclic triterpene used in traditional Chinese medicine with significant weight-lowering effects. Celastrol-administered mice at 100 mu g/kg decrease food consumption and body weight via a leptin-dependent mechanism, yet its molecular targets in this pathway remain elusive. Here, we demonstrate in vivo that celastrol-induced weight loss is largely mediated by the inhibition of leptin negative regulators protein tyrosine phosphatase (PTP) 1B (PTP1B) and T-cell PTP (TCPTP) in the arcuate nucleus (ARC) of the hypothalamus. We show in vitro that celastrol binds reversibly and inhibits noncompetitively PTP1B and TCPTP. NMR data map the binding site to an allosteric site in the catalytic domain that is in proximity of the active site. By using a panel of PTPs implicated in hypothalamic leptin signaling, we show that celastrol additionally inhibited PTEN and SHP2 but had no activity toward other phosphatases of the PTP family. These results suggest that PTP1B and TCPTP in the ARC are essential for celastrol's weight lowering effects in adult obese mice.
Wissenschaftlicher Artikel
Scientific Article
Hadian, K. ; Brenke, J.K. ; Plettenburg, O. ; Jürjens, G.
Schutzrecht WO 2018050286 (2018)
The invention relates to compounds which are suitable for the treatment of cancer, an immune disease, Parkinson's disease, Cardiac Hypertrophy or Type-2 diabetes and to pharmaceutical compositions containing such compounds. The invention further relates to a kit of parts comprising such compounds.
Duro-Castano, A. ; Lim, N.H. ; Tranchant, I. ; Amoura, M. ; Beau, F. ; Wieland, H. ; Kingler, O. ; Hermann, M. ; Nazaré, M. ; Plettenburg, O. ; Dive, V. ; Vicent, M.J. ; Nagase, H.
Adv. Func. Mat. 28:1802738 (2018)
Imaging early molecular changes in osteoarthritic (OA) joints is instrumental for the development of disease-modifying drugs. To this end, a fluorescent resonance energy transfer-based peptide probe that is cleavable by matrix metalloproteinase 13 (MMP-13) has been developed. This protease degrades type II collagen, a major matrix component of cartilage. The probe exhibits high catalytic efficiency (k(cat)/K-M = 6.5 x 10(5) m(-1) s(-1)) and high selectivity for MMP-13 over a set of nine MMPs. To achieve optimal in vivo pharmacokinetics and tissue penetration, the probe has been further conjugated to a linear l-polyglutamate chain of 30 kDa. The conjugate detects early biochemical events that occur in a surgically induced murine model of OA before major histological changes. The nanometric probe is suitable for the monitoring of in vivo efficacy of an orally bioavailable MMP-13 inhibitor, which effectively blocks cartilage degradation during the development of OA. This new polymer-probe can therefore be a useful tool in detecting early OA, disease progression, and in developing MMP-13-based disease-modifying drugs for OA.
Wissenschaftlicher Artikel
Scientific Article
Brenke, J.K. ; Popowicz, G.M. ; Schorpp, K.K. ; Rothenaigner, I. ; Roesner, M. ; Meininger, I. ; Kalinski, C. ; Ringelstetter, L. ; R'kyek, O. ; Jürjens, G. ; Vincendeau, M. ; Plettenburg, O. ; Sattler, M. ; Krappmann, D. ; Hadian, K.
J. Biol. Chem. 293, 13191-13203 (2018)
Constitutive NE-kappa B signaling represents a hallmark of chronic inflammation and autoimmune diseases. The E3 ligase TNF receptor-associated factor 6 (TRAF6) acts as a key regulator bridging innate immunity, pro-inflammatory cytokines, and antigen receptors to the canonical NF-kappa B pathway. Structural analysis and point mutations have unraveled the essential role of TRAF6 binding to the E2-conjugating enzyme ubiquitin-conjugating enzyme E2 N (Ubc13 or UBE2N) to generate Lys63-linked ubiquitin chains for inflammatory and immune signal propagation. Genetic mutations disrupting TRAF6-Ubc13 binding have been shown to reduce TRAF6 activity and, consequently, NE-kappa B activation. However, to date, no small-molecule modulator is available to inhibit the TRAF6-Ubc13 interaction and thereby counteract NF-kappa B signaling and associated diseases. Here, using a high-throughput small-molecule screening approach, we discovered an inhibitor of the TRAF6 -Ubc13 interaction that reduces TRAF6-Ubc13 activity both in vitro and in cells. We found that this compound, C25-140, impedes NF-kappa B activation in various immune and inflammatory signaling pathways also in primary human and murine cells. Importantly, C25-140 ameliorated inflammation and improved disease outcomes of autoimmune psoriasis and rheumatoid arthritis in preclinical in vivo mouse models. Hence, the first-in-class TRAF6-Ubc13 inhibitor C25-140 expands the toolbox for studying the impact of the ubiquitin system on immune signaling and underscores the importance of TRAF6 E3 ligase activity in psoriasis and rheumatoid arthritis. We propose that inhibition of TRAF6 activity by small molecules represents a promising novel strategy for targeting autoimmune and chronic inflammatory diseases.
Wissenschaftlicher Artikel
Scientific Article
Yue, Q. ; Stahl, F.R. ; Plettenburg, O. ; Kirschning, A. ; Warnecke, A. ; Zeilinger, C.
Biochemistry 57, 2601-2605 (2018)
The heat shock protein 90 (Hsp90) family plays a critical role in maintaining the homeostasis of the intracellular environment for human and prokaryotic cells. Hsp90 orthologues were identified as important target proteins for cancer and plant disease therapies. It was shown that gambogic acid (GBA) has the potential to inhibit human Hsp90. However, it is unknown whether it is also able to act on the bacterial high-temperature protein (HtpG) analogue. In this work, we screened GBA and nine other novel potential Hsp90 inhibitors using a miniaturized high-throughput protein microarray-based assay and found that GBA shows an inhibitory effect on different Hsp90s after dissimilarity analysis of the protein sequence alignment. The dissociation constant of GBA and HtpG Xanthomonas (XcHtpG) computed from microscale thermophoresis is 682.2 ± 408 μM in the presence of ATP, which is indispensable for the binding of GBA to XcHtpG. Our results demonstrate that GBA is a promising Hsp90/HtpG inhibitor. The work further demonstrates that our assay concept has great potential for finding new potent Hsp/HtpG inhibitors.
Wissenschaftlicher Artikel
Scientific Article
2017
Haack, T. ; Plettenburg, O. ; Wagner, M. ; Bossart, M. ; Betrand, R.
Schutzrecht WO 2017/102613 A1 (2017)
The present invention relates to exendin-4 peptide analogues which selectively bind and activate the glucagon receptor and comprise a chelating moiety capable of binding a metal ion and their use, for example in PET imaging.
Petry, S. ; Plettenburg, O. ; Tennagels, N. ; Werner, U.
Schutzrecht WO 2017/207754 A1 (2017)
The invention describes novel conjugates of formula (I) of a pharmaceutical agent and a moiety capable of binding to a glucose sensing protein allowing a reversible release of the pharmaceutical agent depending on the glucose concentration.
Eriksson, O. ; Bossart, M. ; Haack, T.B. ; Laitinen, I. ; Larsen, P. ; Plettenburg, O. ; Johansson, L. ; Pierrou, S. ; Wagner, M. ; Velikyan, I.
Diabetologia 60, S400-S400 (2017)
Meeting abstract
Meeting abstract
Keipert, S. ; Kutschke, M. ; Ost, M. ; Schwarzmayr, T. ; van Schothorst, E.M. ; Lamp, D. ; Brachthäuser, L. ; Hamp, I. ; Mazibuko-Mbeje, S. ; Hartwig, S. ; Lehr, S. ; Graf, E. ; Plettenburg, O. ; Neff, F. ; Tschöp, M.H. ; Jastroch, M.
Cell Metab. 26, 437-446.e5 (2017)
Brown adipose tissue (BAT)-dependent thermogenesis and its suggested augmenting hormone, FGF21, are potential therapeutic targets in current obesity and diabetes research. Here, we studied the role of UCP1 and FGF21 for metabolic homeostasis in the cold and dissected underlying molecular mechanisms using UCP1-FGF21 double-knockout mice. We report that neither UCP1 nor FGF21, nor even compensatory increases of FGF21 serum levels in UCP1 knockout mice, are required for defense of body temperature or for maintenance of energy metabolism and body weight. Remarkably, cold-induced browning of inguinal white adipose tissue (iWAT) is FGF21 independent. Global RNA sequencing reveals major changes in response to UCP1- but not FGF21-ablation in BAT, iWAT, and muscle. Markers of mitochondrial failure and inflammation are observed in BAT, but in particular the enhanced metabolic reprogramming in iWAT supports the thermogenic role of UCP1 and excludes an important thermogenic role of endogenous FGF21 in normal cold acclimation.
Wissenschaftlicher Artikel
Scientific Article
Li, J. ; Chu, M.K. ; Lu, B. ; Mirzaie, S. ; Chen, K. ; Gordijo, C.R. ; Plettenburg, O. ; Giacca, A. ; Wu, X.Y.
Drug Deliv. Transl. Res. 7, 529-543 (2017)
Development of highly concentrated formulations of protein and peptide drugs is a major challenge due to increased susceptibility to aggregation and precipitation. Numerous drug delivery systems including implantable and wearable controlled-release devices require thermally stable formulations with high concentrations due to limited device sizes and long-term use. Herein we report a highly concentrated insulin gel formulation (up to 80 mg/mL, corresponding to 2200 IU/mL), stabilized with a non-ionic amphiphilic triblock copolymer (i.e., Pluronic F-127 (PF-127)). Chemical and physical stability of insulin was found to be improved with increasing polymer concentration, as evidenced by reduced insulin fibrillation, formation of degradation products, and preserved secondary structure as measured by HPLC and circular dichroism spectroscopy, respectively. This formulation exhibits excellent insulin stability for up to 30 days in vitro under conditions of continuous shear at 37 °C, attributable to the amphiphilic properties of the copolymer and increased formulation viscosity. The mechanism of stabilizing insulin structure by PF-127 was investigated by coarse-grained molecular dynamics (CG-MD), all-atom MD, and molecular docking simulations. The computation results revealed that PF-127 could reduce fibrillation of insulin by stabilizing the secondary structure of unfolded insulin and forming hydrophobic interaction with native insulin. The gel formulations contained in microfabricated membrane-reservoir devices released insulin at a constant rate dependent on both membrane porosity and copolymer concentration. Subcutaneous implantation of the gel formulation-containing devices into diabetic rats resulted in normal blood glucose levels for the duration of drug release. These findings suggest that the thermally stable gel formulations are suitable for long-term and implantable drug delivery applications.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O.
Angew. Chem.-Int. Edit. 56, 446-448 (2017)
Covalently binding molecules are frequently regarded as being generally promiscuous. In a recent study, binding selectivities and cellular target proteins of a wide variety of reactive fragments are examined in a proteome-wide context.
Wissenschaftlicher Artikel
Scientific Article
2016
Bertrand, R. ; Wagner, M. ; Derdau, V. ; Plettenburg, O.
Bioconjug. Chem. 27, 2281-2286 (2016)
Chemoselective functionalization of peptides and proteins to selectively introduce residues for detection, capture, or specific derivatization is of high interest to the synthetic community. Here we report a new method for the mild and effective mono iodination of tyrosine residues in fully unprotected peptides. This method is highly chemoselective and compatible with a wide variety of functional groups. The introduced iodine can subsequently serve as a handle for further functionalization such as introduction of fluorescent dyes and thus be used for chemoselective labeling of isolated peptides.
Wissenschaftlicher Artikel
Scientific Article
Bertrand, R. ; Hamp, I. ; Brönstrup, M. ; Weck, R. ; Lukacevic, M. ; Polyak, A. ; Ross, T.L. ; Gotthardt, M. ; Plettenburg, O. ; Derdau, V.
J. Labelled Comp. Radiopharm. 59, 604-610 (2016)
Diabetes affects an increasing number of patients worldwide and is responsible for a significant rise in healthcare expenses. Imaging of β-cells in vivo is expected to contribute to an improved understanding of the underlying pathophysiology, improved diagnosis, and development of new treatment options for diabetes. Here, we describe the first radiosyntheses of [(3) H]-TAK875 and [(18) F]-TAK875 derivatives to be used as β-cell imaging probes addressing the free fatty acid receptor 1 (FFAR1/GPR40). The fluorine-labeled derivative showed similar agonistic activity as TAK875 in a functional assay. The radiosynthesis of the (18) F-labelled tracer 2a was achieved with 16.7 ± 5.7% radiochemical yield in a total synthesis time of 60-70 min.
Wissenschaftlicher Artikel
Scientific Article
Bertrand, R. ; Wolf, A. ; Ivashchenko, Y. ; Löhn, M. ; Schäfer, M. ; Brönstrup, M. ; Gotthardt, M. ; Derdau, V. ; Plettenburg, O.
ACS Chem. Biol. 11, 1745-1754 (2016)
Diabetes affects an increasing number of patients worldwide and is responsible for a significant rise in healthcare expenses. Imaging of β-cells bears the potential to contribute to an improved understanding, diagnosis, and development of new treatment options for diabetes. Here, we describe the first small molecule fluorescent probe targeting the free fatty acid receptor 1 (FFAR1/GPR40). This receptor is highly expressed on β-cells, and was up to now unexplored for imaging purposes. We designed a novel probe by facile modification of the selective and potent FFAR1 agonist TAK-875. Effective and specific binding of the probe was demonstrated using FFAR1 overexpressing cells. We also successfully labeled FFAR1 on MIN6 and INS1E cells, two widely used β-cell models, by applying an effective amplification protocol. Finally, we showed that the probe is capable of inducing insulin secretion in a glucose-dependent manner, thus demonstrating that functional activity of the probe was maintained. These results suggest that our probe represents a first important step to successful β-cell imaging by targeting FFAR1. The developed probe may prove to be particularly useful for in vitro and ex vivo studies of diabetic cellular and animal models to gain new insights into disease pathogenesis.
Wissenschaftlicher Artikel
Scientific Article
2015
Hu, H.Y. ; Nazare, M. ; Han Lim, N. ; Ding-Pfennigdorff, D. ; Plettenburg, O. ; Ritzeler, O. ; Juretschke, H.P. ; Saas, J. ; Bartinek, E. ; Florian, P. ; Wendt, U. ; Schultz, C. ; Nagase, H.
Schutzrecht WO 2015075699 (2015)
Hu, H.Y. ; Lim, N.H. ; Ding-Pfennigdorff, D. ; Saas, J. ; Wendt, K.U. ; Ritzeler, O. ; Nagase, H. ; Plettenburg, O. ; Schultz, C. ; Nazare, M.
Bioconjug. Chem. 26, 383-388 (2015)
Targeted drug-delivery methods are crucial for effective treatment of degenerative joint diseases such as osteoarthritis (OA). Toward this goal, we developed a small multivalent structure as a model drug for the attenuation of cartilage degradation. The DOTAM (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid amide)-based model structure is equipped with the cathepsin D protease inhibitor pepstatin A, a fluorophore, and peptide moieties targeting collagen II. In vivo injection of these soluble probes into the knee joints of mice resulted in 7-day-long local retention, while the drug carrier equipped with a scrambled peptide sequence was washed away within 6-8 h. The model drug conjugate successfully reduced the cathepsin D protease activity as measured by release of GAG peptide. Therefore, these conjugates represent a promising first drug conjugate for the targeted treatment of degenerative joint diseases.
Wissenschaftlicher Artikel
Scientific Article
Li, J. ; Chu, M.K. ; Gordijo, C.R. ; Abbasi, A.Z. ; Chen, K. ; Adissu, H.A. ; Löhn, M. ; Giacca, A. ; Plettenburg, O. ; Wu, X.Y.
Biomaterials 47, 51-61 (2015)
Implantation of a medical implant within the body inevitably triggers a host inflammatory response that negatively impacts its function and longevity. Nevertheless, the degree and severity of this response may be reduced by selecting appropriate materials, implant geometry, surface topography and surface treatment. Here we demonstrate a strategy to improve the biocompatibility of a chemically-driven closed-loop insulin delivery implant. A microfabricated microporous, poly(ethylene glycol)-grafted polydimethylsiloxane membrane was placed on top of the glucose-responsive insulin release plug of the implant. Implant biocompatibility was assessed in healthy rats while implant function was evaluated in a type 1 diabetic rat model. The microporous membrane with a small distance to the plug provided a geometric barrier to inflammatory cell migration and prevented leukocyte-mediated degradation of the plug for at least 30 days. Membrane-protected devices elicited a significantly milder inflammatory response and formation of a well-defined fibrous capsule at the device opening compared to unprotected devices. The device's glucose-responsiveness was nearly unchanged, although the insulin release rate decreased with decreasing pore size. The microporous membrane improved biocompatibility and prolonged in vivo efficacy of the implant by ∼3-fold. This work suggests the importance of implant design in modulating inflammatory response and thereby extending the functional duration of the implant.
Wissenschaftlicher Artikel
Scientific Article
Löhn, M. ; Plettenburg, O. ; Kannt, A. ; Kohlmann, M. ; Hofmeister, A. ; Kadereit, D. ; Monecke, P. ; Schiffer, A. ; Schulte, A. ; Ruetten, H. ; Ivashchenko, Y.
World J. Cardiol. 7, 31-42 (2015)
AIM: To compare the therapeutic efficacy of SAR407899 with the current standard treatment for hypertension [an angiotensin converting enzyme (ACE)-inhibitor and a calcium channel blocker] and compare the frequency and severity of the hypertension-related end-organ damage. METHODS: Long-term pharmacological characte-rization of SAR407899 has been performed in two animal models of hypertension, of which one is sensitive to ACE-inhibition (LNAME) and the other is insensitive [deoxycorticosterone acetate (DOCA)]. SAR407899 efficiently lowered high blood pressure and significantly reduced late-stage end organ damage as indicated by improved heart, kidney and endothelial function and reduced heart and kidney fibrosis in both models of chronic hypertension. RESULTS: Long term treatment with SAR407899 has been well tolerated and dose-dependently reduced elevated blood pressure in both models with no signs of tachyphylaxia. Blood pressure lowering effects and protective effects on hypertension related end organ damage of SAR407899 were superior to ramipril and amlodipine in the DOCA rat. Typical end-organ damage was significantly reduced in the SAR407899-treated animals. Chronic administration of SAR407899 significantly reduced albuminuria in both models. The beneficial effect of SAR407899 was associated with a reduction in leukocyte/macrophage tissue infiltration. The overall protective effect of SAR407899 was superior or comparable to that of ACE-inhibition or calcium channel blockade. Chronic application of SAR407899 protects against hypertension and hypertension-induced end organ damage, regardless of the pathophysiological mechanism of hypertension. CONCLUSION: Rho-kinases-inhibition by the SAR407899 represents a new therapeutic option for the treatment of hypertension and its complications.
Wissenschaftlicher Artikel
Scientific Article
Chu, M.K. ; Gordijo, C.R. ; Li, J. ; Abbasi, A.Z. ; Giacca, A. ; Plettenburg, O. ; Wu, X.Y.
Diabetes Technol. Ther. 17, 255-267 (2015)
An implantable, glucose-responsive insulin delivery microdevice was reported previously by our group, providing rapid insulin release in response to hyperglycemic events and efficacy in vivo over a 1-week period when implanted intraperitoneally in rats with diabetes. Herein, we focused on the improvement of the microdevice prototype for long-term glycemic control by subcutaneous (SC) implantation, which allows for easy retrieval and replacement as needed. To surmount the strong immune response to the SC implant system, the microdevice was treated by surface modification with high-molecular-weight polyethylene glycol (PEG). In vitro glucose-responsive insulin release, in vivo efficacy, and biocompatibility of the microdevice were studied. Modification with 20-kDa PEG chains greatly reduced the immune response without a significant change in glucose-responsive insulin release in vitro. The fibrous capsule thickness was reduced from approximately 1,000 μm for the untreated devices to 30-300 μm for 2-kDa PEG-treated and to 30-50 μm for 20-kDa PEG-treated devices after 30 days of implantation. The integrity of the glucose-responsive bioinorganic membrane and the resistance to acute and chronic immune response were improved with the long-chain 20-kDa PEG brush layer. The 20-kDa PEG-treated microdevice provided long-term maintenance of euglycemia in a rat model of diabetes for up to 18 days. Moreover, a consistent rapid response to short-term glucose challenge was demonstrated in multiple-day tests for the first time on rats with diabetes in which the devices were implanted. The improvement of the microdevice is a promising step toward a long-acting insulin implant system for a true, closed-loop treatment of diabetes.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Löhn, M.
In: Czechtizky, W.* ; Hamley, P.* [Eds.]: Small Molecule Medicinal Chemistry: Strategies and Technologies. Wiley Blackwell, 2015. 465-501
In vivo imaging has evolved to be one of the most powerful methods to assist modern drug development, and to enable monitoring of disease progression in longitudinal studies by noninvasive methods in living animals. This chapter discusses the general principles and concepts of in vivo imaging and probe design, that are used to visualize the distribution behavior and effects of drug treatment. It provides some selected case studies in the areas of oncology, CNS, and diabetes. Some examples for translating these results into clinical practice are also discussed. The imaging techniques discussed in the chapter are magnetic resonance imaging (MRI), X-ray computer tomography (CT), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and fluorescence-or luminescence-based technologies. Key to success is an early, reliable diagnosis, and allowing clear assessment of the actual disease stage, thus opening up opportunities for therapeutic intervention at an early point in time.
2014
Hu, H.Y. ; Vats, D. ; Vizovisek, M. ; Krämer, L. ; Germanier, C. ; Wendt, K.U. ; Rudin, M. ; Turk, B. ; Plettenburg, O. ; Schultz, C.
Angew. Chem.-Int. Edit. 53, 7669-7673 (2014)
The synthesis and evaluation of two cathepsin S-specific probes is described. For long-term retention of the probe at the target site and a high signal-to-noise ratio, we introduced a lipidation approach via the simple attachment of palmitoic acid to the reporter. After cathepsin S-specific cleavage in cultured cells and in a grafted tumor mouse model, fluorescence increased owing to dequenching and we observed an intracellular accumulation of the fluorescence in the target tissue. The lipidated probe provided a prolonged and strongly fluorescent signal in tumors when compared to the very similar non-lipidated probe, demonstrating that non-invasive tumor identification is feasable. The homing principle by probe lipidation might also work for selective administration of cytotoxic compounds to specifically reduce tumor mass.
Wissenschaftlicher Artikel
Scientific Article
Hu, H.Y. ; Gehrig, S. ; Reither, G. ; Subramanian, D. ; Mall, M.A. ; Plettenburg, O. ; Schultz, C.
Biotechnol. J. 9, 266-281 (2014)
The continuous detection of enzyme activities and their application in medical diagnostics is one of the challenges in the translational sciences. Proteinases represent one of the largest groups of enzymes in the human genome and many diseases are based on malfunctions of proteolytic activity. Fluorescent sensors may shed light on regular and irregular proteinase activity in vitro and in vivo and provide a deeper insight into the function of these enzymes and their role in pathophysiological processes. The focus of this review is on Förster resonance energy transfer (FRET)-based proteinase sensors and reporters because these probes are most likely to provide quantitative data. The medical relevance of proteinases are discussed using lung diseases as a prominent example. Probe design and probe targeting are described and fluorescent probe development for disease-relevant proteinases, including matrix-metalloproteinases, cathepsins, caspases, and other selected proteinases, is reviewed.
Wissenschaftlicher Artikel
Scientific Article
Grisk, O. ; Koenen, A. ; Meissner, T. ; Donner, A. ; Braun, D. ; Steinbach, A. ; Glöckl, G. ; Zimmermann, U. ; Evert, K. ; Evert, M. ; Katsari, E. ; Löhn, M. ; Plettenburg, O. ; Rettig, R.
J. Hypertens. 32, 2199-2210 (2014)
OBJECTIVES: The therapeutic use of the vascular endothelial growth factor (VEGF) antagonist sunitinib is limited by sunitinib-induced hypertension. The hypotheses were tested that sunitinib increases renal vascular resistance (RVR) and renal Na+ reabsorption, and that Rho kinase (ROCK) inhibition blunts sunitinib-induced hypertension. METHODS: Sunitinib actions on human and rat resistance arteries were investigated by myography. The effects of sunitinib alone or in combination with a ROCK inhibitor on arterial pressure and renal function were investigated in rats by radiotelemetry, renal function and metabolism studies accompanied by biochemical, molecular and histological analyses. RESULTS: Sunitinib blunted agonist-induced vasoconstriction and facilitated endothelium-dependent vasodilation. Within 4 days, sunitinib treatment caused arterial pressure and RVR to rise by 30 mmHg and 5 mmHg × ml × min × g kidney weight, respectively, accompanied by reduced glomerular filtration rate and fractional Na+ excretion with unaffected fractional Li+ excretion. ROCK inhibition blunted sunitinib-induced hypertension and prevented the early rise in RVR, but not the decrease in fractional Na+ excretion, which may explain its modest effect on sunitinib-induced hypertension. CONCLUSION: Our data indicate that early sunitinib-induced hypertension is associated with modest alterations in renal vascular function, but markedly increased renal sodium reabsorption, probably due to direct actions of the VEGF antagonist on the collecting duct, suggesting that VEGF receptors regulate renal Na+ absorption.
Wissenschaftlicher Artikel
Scientific Article
2013
Babelova, A. ; Jansen, F. ; Sander, K. ; Löhn, M. ; Schäfer, L. ; Fork, C. ; Ruetten, H. ; Plettenburg, O. ; Stark, H. ; Daniel, C. ; Amann, K. ; Pavenstädt, H. ; Jung, O. ; Brandes, R.P.
PLoS ONE 8:e80328 (2013)
Rho-family GTPases like RhoA and Rac-1 are potent regulators of cellular signaling that control gene expression, migration and inflammation. Activation of Rho-GTPases has been linked to podocyte dysfunction, a feature of chronic kidney diseases (CKD). We investigated the effect of Rac-1 and Rho kinase (ROCK) inhibition on progressive renal failure in mice and studied the underlying mechanisms in podocytes. SV129 mice were subjected to 5/6-nephrectomy which resulted in arterial hypertension and albuminuria. Subgroups of animals were treated with the Rac-1 inhibitor EHT1846, the ROCK inhibitor SAR407899 and the ACE inhibitor Ramipril. Only Ramipril reduced hypertension. In contrast, all inhibitors markedly attenuated albumin excretion as well as glomerular and tubulo-interstitial damage. The combination of SAR407899 and Ramipril was more effective in preventing albuminuria than Ramipril alone. To study the involved mechanisms, podocytes were cultured from SV129 mice and exposed to static stretch in the Flexcell device. This activated RhoA and Rac-1 and led via TGFβ to apoptosis and a switch of the cells into a more mesenchymal phenotype, as evident from loss of WT-1 and nephrin and induction of α-SMA and fibronectin expression. Rac-1 and ROCK inhibition as well as blockade of TGFβ dramatically attenuated all these responses. This suggests that Rac-1 and RhoA are mediators of podocyte dysfunction in CKD. Inhibition of Rho-GTPases may be a novel approach for the treatment of CKD.
Wissenschaftlicher Artikel
Scientific Article
2012
Grisk, O. ; Schlüter, T. ; Reimer, N. ; Zimmermann, U. ; Katsari, E. ; Plettenburg, O. ; Löhn, M. ; Wollert, H.G. ; Rettig, R.
J. Hypertens. 30, 980-989 (2012)
OBJECTIVES: Increased renal vascular resistance contributes to the pathogenesis of hypertension. The new Rho kinase (ROCK) inhibitor SAR407899 more potently lowers arterial pressure than the commercially available ROCK inhibitor Y27623. We tested whether ROCK inhibition more effectively reduced agonist-induced vasoconstriction in renal than in nonrenal resistance arteries and if SAR407899 more potently inhibits agonist-induced vasoconstriction than Y27632. METHODS: The effects of the ROCK inhibitors on endothelin-1 (ET-1) induced vasoconstriction were investigated in isolated renal and coronary arteries from lean, normotensive Dark Agouti and obese, type 2 diabetic Zucker diabetic fatty (ZDF) rats as well as in isolated human resistance arteries from the kidney and thymus. Vascular ROCK mRNA abundance was studied by real-time PCR (RT-PCR). RESULTS: ET-1-induced constriction depended more on ROCK in rat and human renal resistance arteries than in rat coronary or human thymic arteries, respectively. SAR407899 was more effective than Y27632 in reducing ET-1-induced vasoconstriction in ZDF rat renal resistance arteries. Maximum ET-1-induced vasoconstriction in SAR407899-treated and Y27632-treated human renal resistance arteries was 23 ± 5 and 48 ± 6% of control values, respectively. Transcripts of both ROCK isoforms were detected in rat and human renal resistance arteries. In human thymic arteries, only the ROCK2 transcript was found. CONCLUSION: ET-1-induced vasoconstriction is more ROCK-dependent in renal than in nonrenal resistance arteries. SAR407899 causes a greater inhibition of ET-1-induced vasoconstriction in renal resistance arteries from ZDF rats and patients than Y27632. The greater efficacy in renal vessels may contribute to the higher antihypertensive potency of SAR407899 compared with Y27632.
Wissenschaftlicher Artikel
Scientific Article
McNicholas, T.P. ; Yum, K. ; Ahn, J.H. ; Mu, B. ; Plettenburg, O. ; Gooderman, A. ; Natesan, S. ; Strano, M.S.
Small 8, 3510-3516 (2012)
Understanding the structure and function of glucose binding proteins (GBP) complexed with single walled carbon nanotubes (SWNTs) is important for the development of applications including fluorescent sensors and nanostructure particle tracking. Herein, circular dichroism (CD), thermal denaturation, photo-absorption spectroscopy and atomic force microscopy are used to study these nanostructures. The protein retains its glucose-binding activity after complexation and is thermally stable below 36 °C. However, the SWNT lowers the midpoint denaturation temperature (Tm) by 5 °C and 4 °C in the absence and presence of 10 mM glucose, respectively. This data highlights that using techniques such as CD and thermal denaturation may be necessary to fully characterize such protein-nanomaterial nanostructures.
Wissenschaftlicher Artikel
Scientific Article
2009
Löhn, M. ; Plettenburg, O. ; Ivashchenko, Y. ; Kannt, A. ; Hofmeister, A. ; Kadereit, D. ; Schaefer, M. ; Linz, W. ; Kohlmann, M. ; Herbert, J.M. ; Janiak, P. ; O'Connor, S.E. ; Ruetten, H.
Hypertension 54, 676-683 (2009)
Recent advances in basic and clinical research have identified Rho kinase as an important target potentially implicated in a variety of cardiovascular diseases. Rho kinase is a downstream mediator of RhoA that leads to stress fiber formation, membrane ruffling, smooth muscle contraction, and cell motility. Increased Rho-kinase activity is associated with vasoconstriction and elevated blood pressure. We identified a novel inhibitor of Rho kinase (SAR407899) and characterized its effects in biochemical, cellular, tissue-based, and in vivo assays. SAR407899 is an ATP-competitive Rho-kinase inhibitor, equipotent against human and rat-derived Rho-kinase 2 with inhibition constant values of 36 nM and 41 nM, respectively. It is highly selective in panel of 117 receptor and enzyme targets. SAR407899 is approximately 8-fold more active than fasudil. In vitro, SAR407899 demonstrated concentration-dependent inhibition of Rho-kinase-mediated phosphorylation of myosin phosphatase, thrombin-induced stress fiber formation, platelet-derived growth factor-induced proliferation, and monocyte chemotactic protein-1-stimulated chemotaxis. SAR407899 potently (mean IC(50) values: 122 to 280 nM) and species-independently relaxed precontracted isolated arteries of different species and different vascular beds. In vivo, over the dose range 3 to 30 mg/kg PO, SAR407899 lowered blood pressure in a variety of rodent models of arterial hypertension. The antihypertensive effect of SAR407899 was superior to that of fasudil and Y-27632. In conclusion, SAR407899 is a novel and potent selective Rho-kinase inhibitor with promising antihypertensive activity.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Lorenz, K. ; Loehn, M. ; Duclos, O. ; Biscarrat, S.
Schutzrecht WO/2009/156092 (2009)
The invention relates to bi- and polycyclic substituted isoquinoline and isoquinolinones of the formula (I) wherein R1 to R12 are as defined in the application useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Lorenz, K. ; Loehn, M. ; Weston, J. ; Kleemann, H.-W.
Schutzrecht WO/2009/156099 (2009)
The invention relates to 6-substituted isoquinoline and isoquinolinone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
2008
Bickel, M. ; Brummerhop, H. ; Frick, W. ; Glombik, H. ; Herling, A.W. ; Heuer, H.O. ; Plettenburg, O. ; Theis, S. ; Werner, U. ; Kramer, W.
Arzneim. Forsch. 58, 574-580 (2008)
AVE2268, a substituted glycopyranoside, is an orally active and selective inhibitor of sodium-dependent glucose transporter 2 (SGLT2; IC50 = 13 nmol/L). Investigation of the pharmacological profile of AVE2268 on urinary glucose excretion (UGE) and blood glucose after glucose challenge (po or Intraperitoneal) was performed in mice and rats. AVE2268 caused a dose-dependent increase of UGE in mice (ID30 = 79 +/- 8.1 mg/kg p.o.) and rats (ID30 = 39.8 +/- 4.0 mg/kg p.o.). AVE2268 in mice was more potent to decrease blood glucose ascent when glucose was given intraperitoneally (ID50 = 13.2 +/- 3.9 mg/ kg), compared to orally administered glucose (ID50 = 26.1 +/- 3.9 mg/kg), showing that AVE2268 has no effects on SGLT 1 in the gut in vivo, which is in accordance with ist very low affinity to the SGLT 1 in vitro (IC50 >10,000 nmol/L). During an oral glucose tolerance test, AVE2268 dose-dependently increased UGE, with subsequent decreases of AUC and blood glucose. A highly significant inverse correlation between AUC and UGE was found (p < 0.001). The increase in UGE is linked to the inhibition of SGLT2 only. This profile renders AVE2268 as a new antidiabetic drug for the treatment of type 2 diabetes.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Lorenz, K. ; Goerlitzer, J. ; Löhn, M. ; Biscarrat, S. ; Jeannot, F. ; Duclos, Ol
Schutzrecht WO/2008/077556 (2008)
The invention relates to 6-substituted isoquinoline and isoquinolinone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Brendel, J. ; Löhn, M.
Schutzrecht WO/2008/077550 (2008)
The invention relates to 6-substituted isoquinoline and isochinolone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Goerlitzer, J. ; Löhn, M.
Schutzrecht WO/2008/077552 (2008)
The invention relates to 6-substituted isoquinoline and isochinolone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Goerlitzer, J. ; Löhn, M.
Schutzrecht WO/2008/077553 (2008)
The invention relates to 6-substituted isoquinoline and isoquinolinone derivatives of the Formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Kadereit, D. ; Peukert, S. ; Ruf, S. ; Löhn, M. ; Monecke, P. ; Schiffer, A. ; Kannt, A. ; Kohlmann, M.
Schutzrecht WO/2008/077554 (2008)
The invention relates to 6-substituted isoquinoline derivatives of the Formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Lorenz, K. ; Brendel, J. ; Löhn, M. ; Weston, J.
Schutzrecht WO/2008/077551 (2008)
The invention relates to 6-substituted isoquinolone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Lorenz, K. ; Goerlitzer, J. ; Löhn, M.
Schutzrecht WO/2008/077555 (2008)
The invention relates to 6-substituted isoquinoline and isochinolone derivatives of the formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
2007
Plettenburg, O. ; Hofmeister, A. ; Kadereit, D. ; Peukert, S. ; Ruf, S. ; Ritter, K. ; Löhn, M. ; Ivashchenko, Y. ; Monecke, P. ; Dreyer, M. ; Kannt, A.
Schutzrecht WO/2007/000240 (2007)
The invention relates to 6-piperidinyl-substituted isoquinoline derivatives of the formula (I); useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Kadereit, D. ; Brendel, J. ; Loehn, M.
Schutzrecht WO/2007/012422 (2007)
The invention relates to 6-cyclohexylamine-substituted isoquinolone derivatives of the formula (I) or isoquinoline derivatives of the formula (I’) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
Plettenburg, O. ; Hofmeister, A. ; Kadereit, D. ; Brendel, J. ; Loehn, M.
Schutzrecht WO/2007/012421 (2007)
The invention relates to 6-piperidinyl-substituted isoquinolone derivatives of the formula (I) or isoquinoline derivatives of the formula (I´) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
2005
Steioff, K. ; Rütten, H. ; Busch, A.E. ; Plettenburg, O. ; Ivashchenko, Y. ; Löhn, M.
Eur. J. Pharmacol. 512, 247-249 (2005)
Chronic inhibition of Rho-kinase has been recently implicated in retardation of atherogenesis induced by high-fat diet in low-density lipoprotein receptor deficient (LDLR-/-) mice. However, it remains to be examined whether long-term Rho-kinase inhibition will reduce vascular dysfunction in this model. LDLR-/- mice on a high-fat diet were treated either with saline (LDLR-/-) or with the Rho-kinase inhibitor Fasudil (HA1077, 5-Isoquinolinesulfonyl homopiperazine, 100 mg/kg/day by gavage, LDLR-/- +Fasudil) for 10 weeks. Fasudil-treatment normalized endothelial function (measured by means of endothelium-dependent vasorelaxation) in LDLR-/- +Fasudil, to the level of controls (C57BL/6J). No tolerance toward Rho-kinase inhibition has been detected in Fasudil-treated animals. We conclude that long-term Rho-kinase inhibition normalizes endothelial function without development of tolerance.
Wissenschaftlicher Artikel
Scientific Article
Wu, D. ; Xing, G.W. ; Poles, M.A. ; Horowitz, A. ; Kinjo, Y. ; Sullivan, B. ; Bodmer-Narkevitch, V. ; Plettenburg, O. ; Kronenberg, M.F. ; Tsuji, M. ; Ho, D.D. ; Wong, C.H.
Proc. Natl. Acad. Sci. U.S.A. 102, 1351-1356 (2005)
The CD1 family of proteins binds self and foreign glycolipids for presentation to CD1-restricted T cells. To identify previously uncharacterized active CD1 ligands, especially those of microbial origin, numerous glycolipids were synthesized and tested for their ability to stimulate mouse and human natural killer T (NKT) cells. They included analogs of the well known NKT cell agonist alpha-galactosyl ceramide (alpha-GalCer), bacterial glycolipids, and variations of the self-glycolipid, sulfatide. Bacterial glycolipids, alpha-galacturonosyl-ceramides from Sphingomonas wittichii, although structurally similar to alpha-GalCer, have significant differences in the sugar head group as well as the ceramide portion. The Sphingomonas glycosphingolipids (GSLs) and sulfatide variants were shown to activate human NKT cells as measured by IL-4 and IFN-gamma secretion. Moreover, CD1d-dimer staining revealed human NKT cell reactivity toward these GSLs and to the sulfatides in a fashion comparable with alpha-GalCer. Because alpha-GalCer is a marine-sponge-derived ligand, our study here shows that bacterium-derived antigens are also able to stimulate mouse and human NKT cells.
Wissenschaftlicher Artikel
Scientific Article
Podeschwa, M.A. ; Plettenburg, O. ; Altenbach, H.J.
Eur. J. Org. Chem., 3116-3127 (2005)
A practical route is described for the preparation of myo-inositol phosphates. Optically pure compounds can be prepared, in both forms, from p-benzoquinone by enzymatic resolution of a diacetoxyconduritol key intermediate. Monosubstituted inositol derivatives can be obtained by breaking the C-2 symmetry, of conduritol B derivatives. A wide variety of myo-inositol phosphates can be synthesized by combining the previously reported symmetrical approach with this new non-symmetrical approach.
Wissenschaftlicher Artikel
Scientific Article
Podeschwa, M.A. ; Plettenburg, O. ; Altenbach, H.J.
Eur. J. Org. Chem., 3101-3115 (2005)
A practical route is described for the preparation of myo-inositol polyphosphates. Optically pure myo-mositol derivatives can be prepared from p-benzoquinone in both forms by enzymatic resolution of a C-2-symmetric diacetoxyconduritol B key intermediate, followed by cis-dihydroxylation. Selective functionalization of axial and equatorial hydroxy groups allows the synthesis of symmetric mositol phosphates as well as unsymmetrical, enantiomerically pure mositol phosphates.
Wissenschaftlicher Artikel
Scientific Article
Brummerhop, H. ; Frick, W. ; Glombik, H. ; Plettenburg, O. ; Bickel, M. ; Heuer, H. ; Theis, S.
Schutzrecht WO/2005/121161 (2005)
The invention relates to substituted fluoroglycoside derivatives of pyrazoles of formula (I), in which the radicals have the indicated meanings, to the physiologically compatible salts thereof, and to a method for the production thereof. The compounds are suited for as, e.g. antidiabetics.
2004
Glombik, H. ; Frick, W. ; Heuer, H. ; Kramer, W. ; Brummerhop, H. ; Plettenburg, O.
Schutzrecht WO2004007517 A1 (2004)
The invention relates to novel thiophenylglycoside derivatives of formula (I), where the groups have the given meanings, the physiologically-acceptable salts and methods for production thereof. The compounds are suitable as anti-diabetics for example.
Frick, W. ; Glombik, H. ; Kramer, W. ; Heuer, H. ; Brummerhop, H. ; Plettenburg, O.
Schutzrecht WO/2004/052902 (2004)
The invention relates to substituted aromatic fluoroglycoside derivatives of a formula (1), wherein radicals have predefined bonds, to the psychologically tolerated salts thereof, and methods for the preparation thereof. Said compounds can be used, for example in the form of antidiabetic agents.
Frick, W. ; Glombik, H. ; Kramer, W. ; Heuer, H. ; Brummerhop, H. ; Plettenburg, O.
Schutzrecht WO/2004/052903 (2004)
The invention relates to substituted fluoroglycoside heterocyclic derivatives of a formula (I), wherein radicals have predefined bonds, to the psychologically tolerated salts thereof and to methods for the preparation thereof. Said compounds can be used, for example as antidiabetic agents.
2003
Podeschwa, M.A. ; Plettenburg, O. ; Altenbach, H.J.
Org. Biomol. Chem. 1, 1919-1929 (2003)
A practical route is described for the preparation of azido-myo-inositols, amino-myo-inositols and azido-conduritol B derivatives. Starting from p-benzoquinone, optically pure compounds in both forms can be prepared via enzymatic resolution of a derived diacetoxy conduritol B derivative. Selective introduction of nitrogen-containing functional groups in four of the six possible positions in the cyclitol moiety is followed by further functionalization to yield the target compounds.
Wissenschaftlicher Artikel
Scientific Article
Podeschwa, M.A. ; Plettenburg, O. ; vom Brocke, J. ; Block, O. ; Adelt, S. ; Altenbach, H.J.
Eur. J. Org. Chem., 1958-1972 (2003)
A practical route is described for the flexible preparation of a wide variety of inositol stereoisomers and their polyphosphates. The potential of this approach is demonstrated by the synthesis Of myo-, L-chiro-, D-chiro-, epi-, scyllo-, allo-, and neo-inositol systems. Optically pure compounds in either enantiomeric form can be prepared from p-benzoquinone via enzymatic resolution of a derived conduritol B key intermediate. High-performance anion-exchange chromatography with pulsed amperometric detection permits inositol stereoisomers to be resolved and detected with high sensitivity.
Wissenschaftlicher Artikel
Scientific Article
2002
Bryan, M.C. ; Plettenburg, O. ; Sears, P. ; Rabuka, D. ; Wacowich-Sgarbi, S. ; Wong, C.H.
Chem. Biol. 9, 713-720 (2002)
New insight into the importance of carbohydrates in biological systems underscores the need for rapid synthetic and screening procedures for them. Development of an organic synthesis-compatible linker that would attach saccharides to microtiter plates was therefore undertaken to facilitate research in glycobiology. Galactosyllipids containing small, hydrophobic groups at the anomeric position were screened for noncovalent binding to microtiter plates. When the lipid component was a saturated hydrocarbon between 13 and 15 carbons in length, the monosaccharide showed complete retention after aqueous washing and could be utilized in biological assays. This alkyl chain was also successfully employed with more complex oligosaccharides in biological assays. In light of these findings, this method of attachment of oligosaccharides to microtiter plates should be highly efficacious to high-throughput synthesis and analyses of carbohydrates in biological assays.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Bodmer-Narkevitch, V. ; Wong, C.H.
J. Org. Chem. 67, 4559-4564 (2002)
Alpha-galactosyl ceramide has been identified to be a potent stimulatory agent for a novel immunological process, mediated by CD1 molecules. This paper describes a short and efficient synthesis of alpha-galactosyl ceramide. Starting from commercially available 2-deoxy galactose, a suitable sphingosine derivative was obtained in nine steps and 36% overall yield, which was subsequently glycosylated to give the target molecule. This flexible route will provide various glycolipids for further exploration of this interesting biological process.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Mui, C. ; Bodmer-Narkevitch, V. ; Wong, C.
Adv. Synth. Catal. 344, 622-626 (2002)
A new strategy for the synthesis of a well-defined glycolipid library is presented. A highly selective cross metathesis reaction is used to diversify the lipid moiety of anomerically pure alpha- or beta-glycosides, and subsequent functionalization of the double bond allows further expansion of the diversity. These glycolipids are being investigated for their effect on the immune system, especially the CD1-mediated T-cell activation.
Wissenschaftlicher Artikel
Scientific Article
2001
Izumi, M. ; Shen, G.J. ; Wacowich-Sgarbi, S. ; Nakatani, T. ; Plettenburg, O. ; Wong, C.H.
J. Am. Chem. Soc. 123, 10909-10918 (2001)
The alpha-2,3-sialyltransferase from Neisseria gonorrheae was overproduced in E. coli for exploitation of its substrate specificity and synthetic utility. Several potential acceptor substrates were synthesized in this study, including mono- and oligosaccharides, glycolipids, and glycopeptides and their sulfate derivatives. Some CMP-sialic acid derivatives with modification at the C-5 position were also prepared for evaluation as donor substrates. It was found that the enzyme exhibits a broader acceptor substrate specificity when compared to other sialyltransferases, though the donor specificity is quite limited. Application of the enzyme to the preparative synthesis of representative sialyl glycoconjugates has been demonstrated. On the basis of this work and the work of others, this enzyme is the most versatile and synthetically useful among all sialyltransferases known to date, especially for the synthesis of sulfate-containing glycoconjugates.
Wissenschaftlicher Artikel
Scientific Article
Adelt, S. ; Plettenburg, O. ; Dallmann, G. ; Ritter, F.P. ; Shears, S.B. ; Altenbach, H.J. ; Vogel, G.
Bioorg. Med. Chem. Lett. 11, 2705-2708 (2001)
A new de novo synthesis of the enantiomeric pair D-myo-inositol 1,2,4-trisphosphate and D-myo-inositol 2,3,6-trisphosphate is described. Starting from enantiopure dibromocyclohexenediol, several C2 symmetrical building blocks were synthesized which gave access to D-myo-inositol 1,2,4,5-tetrakisphosphate and D-myo-inositol 1,2,3,6-tetrakisphosphate. Exploiting the high regiospecificity of two partially purified phosphohydrolases from Dictyostelium, a 5-phosphatase and a phytase, the inositol tetrakisphosphates were converted enzymatically to the target compounds. Their potential to modulate the activity of Ins3,4,5,6P4 1-kinase was investigated and compared with the effects of D-myo-inositol 1,3,4-trisphosphate.
Wissenschaftlicher Artikel
Scientific Article
1999
Adelt, S. ; Plettenburg, O. ; Stricker, R. ; Reiser, G. ; Altenbach, H.J. ; Vogel, G.
J. Med. Chem. 42, 1262-1273 (1999)
Unambiguous total syntheses of both optical antipodes of the enantiomeric pair d-myo-inositol 3,4,5-trisphosphate (Ins(3,4,5)P3) and d-myo-inositol 1,5,6-trisphosphate (Ins(1,5,6)P3) are described. The ring system characteristic of myo-inositol was constructed de novo from p-benzoquinone. X-ray data for the enzymatically resolved (1S,2R,3R,4S)-1,4-diacetoxy-2,3-dibromocyclohex-5-ene enabled the unequivocal assignment of the absolute configuration. Subsequent transformations under stereocontrolled conditions led to enantiopure C2-symmetrical 1,4-(di-O-benzyldiphospho)conduritol B derivatives. Their synthetic potential was exploited to prepare Ins(3,4,5,6)P4 and Ins(1,4,5,6)P4 in three steps. With a recently identified and partially purified InsP5/InsP4 phosphohydrolase from Dictyostelium discoideum, these enantiomers could be converted to the target compounds, Ins(3,4,5)P3 and Ins(1,5,6)P3, on a preparative scale. An HPLC system employed for both purification of the inositol phosphates and analytical runs ensured that the products were isomerically homogeneous. The sensitivity of detection achieved by a complexometric postcolumn derivatization method indicates that the complexation properties of Ins(3,4,5)P3/Ins(1,5,6)P3 resemble those of Ins(1,2,3)P3, a compound with antioxidant potential. The set of inositol phosphates synthesized was used to clarify structural motifs important for molecular recognition by p42IP4, a high-affinity Ins(1,3,4,5)P4/PtdIns(3,4,5)P3-specific binding protein from pig cerebellum.
Wissenschaftlicher Artikel
Scientific Article
Adelt, S. ; Plettenburg, O. ; Stricker, R. ; Reiser, G. ; Altenbach, H.J. ; Vogel, G.
J. Med. Chem. 42, 1262-1273 (1999)
Unambiguous total syntheses of both optical antipodes of the enantiomeric pair D-myo-inositol 3,4,5-trisphosphate (Ins(3,4,5)P3) and D-myo-inositol 1,5,6-trisphosphate (Ins(1,5,6)P3) are described. The ring system characteristic of myo-inositol was constructed de novo from p-benzoquinone. X-ray data for the enzymatically resolved (1S,2R,3R,4S)-1,4-diacetoxy-2,3-dibromocyclohex-5-ene enabled the unequivocal assignment of the absolute configuration. Subsequent transformations under stereocontrolled conditions led to enantiopure C2-symmetrical 1,4-(di-O-benzyldiphospho)conduritol B derivatives. Their synthetic potential was exploited to prepare Ins(3,4,5,6)P4 and Ins(1,4,5,6)P4 in three steps. With a recently identified and partially purified InsP5/InsP4 phosphohydrolase from Dictyostelium discoideum, these enantiomers could be converted to the target compounds, Ins(3,4,5)P3 and Ins(1,5,6)P3, on a preparative scale. An HPLC system employed for both purification of the inositol phosphates and analytical runs ensured that the products were isomerically homogeneous. The sensitivity of detection achieved by a complexometric postcolumn derivatization method indicates that the complexation properties of Ins(3,4,5)P3/Ins(1,5,6)P3 resemble those of Ins(1,2,3)P3, a compound with antioxidant potential. The set of inositol phosphates synthesized was used to clarify structural motifs important for molecular recognition by p42(IP4), a high-affinity Ins(1,3,4,5)P4/PtdIns(3,4,5)P3-specific binding protein from pig cerebellum.
Wissenschaftlicher Artikel
Scientific Article
Plettenburg, O. ; Adelt, S. ; Vogel, G. ; Altenbach, H.J.
Tetrahedron Asymm. 11, 1057-1061 (1999)
The first total synthesis of Ins(1,2,3,4)P4 and Ins(1,2,3,6)P4 is presented. Starting from p-benzoquinone, we took advantage of the C2-symmetry of conduritol-B intermediates. The target compounds were dephosphorylated by several enzymes, and the resulting InsP3 isomers were identified. Some of these enzymatic conversions were found to be preparatively applicable and to allow the synthesis of Ins(1,2,3)P3, Ins(2,3,6)P3 and Ins(1,2,4)P3.
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