Oppermann, Martin

[["dc.bibliographiccitation.firstpage","405"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","EXPERIMENTAL NEPHROLOGY"],["dc.bibliographiccitation.lastpage","411"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Grunewald, Rolf W."],["dc.contributor.author","Ehrhard, M."],["dc.contributor.author","Fiedler, Gabriele"],["dc.contributor.author","Schuttert, J. B."],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Mueller, Gerhard A."],["dc.date.accessioned","2018-11-07T09:32:11Z"],["dc.date.available","2018-11-07T09:32:11Z"],["dc.date.issued","2001"],["dc.description.abstract","Sorbitol plays a major role in the maintenance of cell volume and functional integrity of several renal cells. Sorbitol synthesis takes place in inner collecting duct cells, whereas sorbitol dehydrogenase activity, which catalyzes the degradation of sorbiotol to fructose, could mainly be detected in renal inner medullary interstitial cells. Therefore, we supposed that interstitial cells would require a sorbitol transport into the cells. However, such a transport system has not yet been described. Therefore, we have characterized the uptake of sorbitol in immortalized interstitial TK-173 cells, which were derived from human renal fibroblasts. Comparable to fresh isolated renal fibroblasts of the rat, immortalized TK-173 cells have a high sorbitol dehydrogenase activity. In this report, a temperature-dependent sorbitol uptake with saturation kinetics could be detected in immortalized TK-173 cells. The transport is characterized by a high velocity (V-max 84 mmol/l x h) and an apparent K-m of 10 mmol/l. The sorbitol uptake is independent of membrane potential, sodium, and chloride. Altogether, the physiological characteristics of this sorbitol transport are different from those of the osmotically regulated sorbitol efflux from epithelial cells. These results provide evidence that TK-173 cells derived from renal fibroblasts have a specific sorbitol transport. Furthermore, these data suggest a cooperation between epithelial and interstitial cells concerning osmoregulation. Copyright (C) 2001 S. Karger AG, Basel."],["dc.identifier.isi","000172203500008"],["dc.identifier.pmid","11702000"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31695"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Karger"],["dc.relation.issn","1018-7782"],["dc.title","Evidence for a sorbitol transport system in immortalized human renal interstitial cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1201"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Cellular Signalling"],["dc.bibliographiccitation.lastpage","1210"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Oppermann, Martin"],["dc.date.accessioned","2018-11-07T10:44:06Z"],["dc.date.available","2018-11-07T10:44:06Z"],["dc.date.issued","2004"],["dc.description.abstract","CC chemokine receptor 5 (CCR5) is a seven-transmembrane, G protein-coupled receptor (GPCR) which regulates trafficking and effector functions of memory/effector T-lymphocytes, macrophages, and immature dendritic cells. It also serves as the main coreceptor for the entry of R5 strains of human immunodeficiency virus (HIV-1, HIV-2). Chemokine binding to CCR5 leads to cellular activation through pertussis toxin-sensitive heterotrimeric G proteins as well as G protein-independent signalling pathways, Like many other GPCR, CCR5 is regulated by agonist-dependent processes which involve G protein coupled receptor kinase (GRK)-dependent phosphorylation, P-arrestin-mediated desensitization and internalization. This review discusses recent advances in the elucidation of the structure and function of CCR5, as well as the complex mechanisms that regulate CCR5 signalling and cell surface expression. (C) 2004 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.cellsig.2004.04.007"],["dc.identifier.isi","000223955300001"],["dc.identifier.pmid","15337520"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/47199"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0898-6568"],["dc.title","Chemokine receptor CCR5: insights into structure, function, and regulation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Naunyn-Schmiedeberg s Archives of Pharmacology"],["dc.bibliographiccitation.volume","365"],["dc.contributor.author","Pollok-Kopp, B."],["dc.contributor.author","Kraft, K."],["dc.contributor.author","Oppermann, Martin"],["dc.date.accessioned","2018-11-07T10:31:35Z"],["dc.date.available","2018-11-07T10:31:35Z"],["dc.date.issued","2002"],["dc.format.extent","R18"],["dc.identifier.isi","000175030900068"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44148"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","New york"],["dc.relation.issn","0028-1298"],["dc.title","Kinetic analysis of PKC- and GRK-mediated phosphorylation of chemokine receptor CCR5 by phosphosite-specific antibodies"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Molecular Immunology"],["dc.bibliographiccitation.volume","43"],["dc.contributor.author","Pollok-Kopp, B."],["dc.contributor.author","Rethorn, S."],["dc.contributor.author","Schwarze, Katrin"],["dc.contributor.author","Huttenrauch, F."],["dc.contributor.author","Oppermann, Martin"],["dc.date.accessioned","2018-11-07T10:38:44Z"],["dc.date.available","2018-11-07T10:38:44Z"],["dc.date.issued","2006"],["dc.format.extent","149"],["dc.identifier.isi","000232021600087"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45879"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.publisher.place","Oxford"],["dc.relation.conference","10th Meeting on Complement in Human Disease"],["dc.relation.eventlocation","Heidelberg, GERMANY"],["dc.relation.issn","0161-5890"],["dc.title","Protein kinase C beta-mediated phosphorylation of Serine-334 of the human C5a anaphylatoxin receptor (C5aR): Modulation by the adapter protein beta-arrestin"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","277"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Ultrasound in Obstetrics and Gynecology"],["dc.bibliographiccitation.lastpage","283"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Viereck, Volker"],["dc.contributor.author","Pauer, H. U."],["dc.contributor.author","Bader, Werner"],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Hilgers, Ralf-Dieter"],["dc.contributor.author","Gauruder-Burmester, A."],["dc.contributor.author","Lange, Rainer"],["dc.contributor.author","Emons, G."],["dc.contributor.author","Hackenberg, R."],["dc.contributor.author","Krauss, T."],["dc.date.accessioned","2018-11-07T10:51:05Z"],["dc.date.available","2018-11-07T10:51:05Z"],["dc.date.issued","2004"],["dc.description.abstract","Objective To assess the topography of the bladder neck by introital ultrasound before and after open colposuspension. Methods Three hundred and ten women with urodynamically proven stress urinary incontinence were included in this long-term study to investigate the position and function of the bladder neck at rest and during straining. Height (H), distance (D), and urethrovesical angle of the bladder neck (beta) were measured by means of preoperative and postoperative introital ultrasound. Women were followed up; 152 of them (49%) completed 48 months of follow-up. Results At the 6-month follow-up examination, 90.0% of the women were continent (279/310), 3.5% (11/310) showed voiding difficulties, 3.5% (11/310) had urgency, and 1.6% (5/310) bad developed de novo urge incontinence. At the 48-month follow-up, 76.8% of the patients were still continent. All postoperative measurements yielded significantly lower values for angle beta at rest and during straining compared with the preoperative results (P < 0.0001). The median linear movement of the bladder neck during straining decreased from 18.0 mm before surgery to 6.4 mm at the 48-month follow-up (P < 0.0001). The median level of ventrocranial elevation of the vesicourethral junction was 14.3 mm immediately after surgery, 9.9 mm after 6 months and 6.6 mm after 48 months. The degree of surgical bladder-neck elevation was associated with postoperative urgency/de novo urge incontinence (P < 0.0001) and voiding difficulty (P < 0.0001). Conclusions The colposuspension procedure reduces angle at rest and during straining, restricts linear movement with straining, and elevates the bladder neck. Perioperative introital ultrasound improves understanding of this surgical procedure and might help to prevent postoperative complications. Copyright (C) 2004 ISUOG. Published by John Wiley Sons, Ltd."],["dc.identifier.doi","10.1002/uog.982"],["dc.identifier.isi","000220287300014"],["dc.identifier.pmid","15027018"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48802"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","John Wiley & Sons Ltd"],["dc.relation.issn","0960-7692"],["dc.title","Introital ultrasound of the lower genital tract before and after colposuspension: a 4-year objective follow-up"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","251"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","HISTOLOGY AND HISTOPATHOLOGY"],["dc.bibliographiccitation.lastpage","258"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Jozsi, M."],["dc.contributor.author","Manuelian, T."],["dc.contributor.author","Heinen, S."],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Zipfel, Peter F."],["dc.date.accessioned","2018-11-07T10:52:37Z"],["dc.date.available","2018-11-07T10:52:37Z"],["dc.date.issued","2004"],["dc.description.abstract","Complement is a central element of innate immunity and this vital defense system initiates and coordinates immediate immune reactions which attack and eliminate microbes, foreign particles and altered self cells. Newly generated activation products are extremely toxic and consequently, activation is highly restricted in terms of time and space. The initial activation of the alternative complement pathway occurs continuously and the early phase acts indiscriminatoryl and forms on any surface. However, the system discriminates between self and foreign, and therefore allows activation on foreign surfaces e.g. Microbes, and restricts activation on host cells. Consequently, self cells and tissues are protected from the harmful activation products. This protection is mediated by specific regulators or inhibitors, which exist in the fluid phase and/or in membrane-bound forms. Here we review a novel mechanism, i.e. the attachment of the soluble complement regulator factor H to the surface of self cells. This attachment, which is demonstrated experimentally by means of immunofluorescense microscopy and by flow cytometry, increases the inhibitory potential at the cell surface and mediates protection by reducing the local formation of toxic inflammatory products. This attachment is highly relevant and has pathophysiological consequences in several human diseases, including Factor H-associated hemolytic uremic syndrome (FH-HUS), membrano-proliferative glomerulonephritis type II, recurrent microbial infections and chronic inflammation, e.g. rheumatoid arthritis and immune evasion of tumor cells. Defects of this safeguard activity have been recently understood in patients with FH-HUS. Point mutations in the Factor H gene occurring in the C-terminus of the protein result in impaired cell binding capacity of Factor H and, consequently, during an inflammatory insult endothelial cells are not properly protected and are damaged."],["dc.identifier.isi","000188355400030"],["dc.identifier.pmid","14702193"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49151"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","F Hernandez"],["dc.relation.issn","0213-3911"],["dc.title","Attachment of the soluble complement regulator factor H to cell and tissue surfaces: relevance for pathology"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1966"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Molecular Pharmacology"],["dc.bibliographiccitation.lastpage","1976"],["dc.bibliographiccitation.volume","67"],["dc.contributor.author","Lagane, B."],["dc.contributor.author","Ballet, S."],["dc.contributor.author","Planchenault, T."],["dc.contributor.author","Balabanian, K."],["dc.contributor.author","Le Poul, E."],["dc.contributor.author","Blanpain, C."],["dc.contributor.author","Percherancier, Y."],["dc.contributor.author","Staropoli, I."],["dc.contributor.author","Vassart, G."],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Parmentier, M."],["dc.contributor.author","Bachelerie, F."],["dc.date.accessioned","2018-11-07T10:57:24Z"],["dc.date.available","2018-11-07T10:57:24Z"],["dc.date.issued","2005"],["dc.description.abstract","CC chemokine receptor 5 (CCR5) is a G protein-coupled receptor that governs migration of leukocytes and serves as a coreceptor for the R5 tropic strains of human immunodeficiency virus (HIV). CCR5-mediated signaling in response to CC chemokines relies on G protein activation. Desensitization, which rapidly turns off G protein-dependent signaling, involves phosphorylation of CCR5 that promotes interaction of the receptor with beta-arrestins for endocytosis. Whether coupling to G proteins, desensitization, and endocytosis of CCR5 require the same structural determinants remains a matter of investigation. Here, we show that CCR5 displayed agonist-independent coupling to G proteins. This constitutive activity of the receptor was abrogated by TAK779 (N,N-dimethyl-N-[4-[[[2-(4-methylphenyl)-6,7-dihydro-5H-benzo-cyclohepten-8-yl]carbonyl]amino]benzyl]tetrahydro-2H-pyran-4-aminium chloride), a nonpeptidic CCR5 ligand that inhibits HIV infection and was found to depend on the integrity of the Asp-Arg-Tyr (DRY) motif. Changing Arg-126 by the neutral residue Asn (R126N-CCR5 mutant) abolished CCR5-mediated activation of G proteins, either constitutively or in response to agonists. In contrast, R126N-CCR5 not only retained agonist-promoted phosphorylation and beta-arrestin-dependent endocytosis but also displayed a higher basal phosphorylation than wild-type CCR5. Expression of beta-arrestin in R126N-CCR5-expressing cells resulted in receptor down-regulation, thereby suggesting that R126N-CCR5 spontaneously interacts with beta-arrestins. However, although expression of beta-arrestin favored wild-type CCR5-mediated chemotaxis, it failed to promote migration of cells expressing R126N-CCR5. Overall, these data indicate that structural requirements for CCR5-mediated activation of G proteins, albeit not involved in receptor desensitization and internalization, are needed for beta-arrestin-mediated chemotaxis. These results have implications for how distinct biological responses of CCR5 might rely on a different set of receptor conformations."],["dc.identifier.doi","10.1124/mol.104.009779"],["dc.identifier.isi","000229141200017"],["dc.identifier.pmid","15761117"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50238"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Pharmacology Experimental Therapeutics"],["dc.relation.issn","0026-895X"],["dc.title","Mutation of the DRY motif reveals different structural requirements for the CC chemokine receptor 5-mediated signaling and receptor endocytosis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","342"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Clinical & Experimental Immunology"],["dc.bibliographiccitation.lastpage","352"],["dc.bibliographiccitation.volume","144"],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Manuelian, T."],["dc.contributor.author","Jozsi, M."],["dc.contributor.author","Brandt, E."],["dc.contributor.author","Jokiranta, T. S."],["dc.contributor.author","Heinen, S."],["dc.contributor.author","Meri, S."],["dc.contributor.author","Skerka, C."],["dc.contributor.author","Gotze, O."],["dc.contributor.author","Zipfel, Peter F."],["dc.date.accessioned","2018-11-07T09:51:20Z"],["dc.date.available","2018-11-07T09:51:20Z"],["dc.date.issued","2006"],["dc.description.abstract","The complement inhibitor Factor H has three distinct binding sites for C3b and for heparin, but in solution uses specifically the most C-terminal domain, i.e. short consensus repeats (SCR) 20 for ligand interaction. Two novel monoclonal antibodies (mABs C14 and C18) that bind to the most C-terminal domain SCR 20 completely blocked interaction of Factor H with the ligands C3b, C3d, heparin and binding to endothelial cells. In contrast, several mAbs that bind to the N-terminus and to the middle regions of the molecule showed no or minor inhibitory effects when assayed by enzyme-linked immunosorbent assay (ELISA) and ligand interaction assays. This paradox between a single functional binding site identified for native Factor H versus multiple interaction sites reported for deletion constructs is explained by a compact conformation of the fluid phase protein with one accessible binding site. On zymosan particles mAbs C14 and C18 blocked alternative pathway activation completely. Thus demonstrating that native Factor H makes the first and initial contact with the C terminus, which is followed by N terminally mediated complement regulation. These results are explained by a conformational hypothetical model: the native Factor H protein has a compact structure and only one binding site accessible. Upon the first contact the protein unfolds and exposes the additional binding sites. This model does explain how Factor H mediates recognition functions during complement control and the clustering of disease associated mutations in patients with haemolytic uraemic syndrome that have been reported in the C-terminal recognition domain of Factor H."],["dc.identifier.doi","10.1111/j.1365-2249.2006.03071.x"],["dc.identifier.isi","000236766600021"],["dc.identifier.pmid","16634809"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35890"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Blackwell Publishing"],["dc.relation.issn","0009-9104"],["dc.title","The C-terminus of complement regulator Factor H mediates target recognition: evidence for a compact conformation of the native protein"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","136"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Nephrology Dialysis Transplantation"],["dc.bibliographiccitation.lastpage","144"],["dc.bibliographiccitation.volume","25"],["dc.contributor.author","Strobel, Stefanie"],["dc.contributor.author","Hoyer, Peter F."],["dc.contributor.author","Mache, Christoph J."],["dc.contributor.author","Sulyok, Endre"],["dc.contributor.author","Liu, Wei-shih"],["dc.contributor.author","Richter, Heiko"],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Zipfel, Peter F."],["dc.contributor.author","Jozsi, Mihaly"],["dc.date.accessioned","2018-11-07T08:48:11Z"],["dc.date.available","2018-11-07T08:48:11Z"],["dc.date.issued","2010"],["dc.description.abstract","Methods. CFH autoantibodies were identified and antibody levels were analysed in three aHUS patients during the disease course by the ELISA method. Epitope mapping was performed using recombinant factor H fragments and domain-mapped monoclonal antibodies. The effect of the antibodies on cell-protective activity of CFH was measured by haemolytic assays. CFH:autoantibody complexes were analysed by ELISA. Results. All three autoantibodies bound to the C-terminal domain of CFH, which is essential for CFH binding to cell surfaces. In patient 1, plasma exchanges and immune adsorption temporarily reduced the autoantibody titre and led to temporary clinical improvement. In patient 2, plasma exchanges and long-term immunosuppression strongly reduced the CFH autoantibody level, and induced a stable remission of aHUS. Patient 3 had lower autoantibody levels that decreased during the follow-up and is in good clinical condition. The patients' plasma samples caused enhanced lysis of sheep erythrocytes, and the degree of lysis correlated with the CFH autoantibody titre and the amount of CFH:autoantibody complexes. An addition of purified CFH to aHUS plasma or removal of IgG inhibited the haemolytic activity. Conclusion. These results support a direct role of the autoantibodies in aHUS pathology by inhibiting the regulatory function of CFH at cell surfaces and suggest that reduction of the autoantibody titre is beneficial for the patients."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft; Kidneeds Foundation, Cedar Rapids, US"],["dc.identifier.doi","10.1093/ndt/gfp388"],["dc.identifier.isi","000273113100024"],["dc.identifier.pmid","19666655"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21150"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","0931-0509"],["dc.title","Functional analyses indicate a pathogenic role of factor H autoantibodies in atypical haemolytic uraemic syndrome"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Allergy and Clinical Immunology"],["dc.bibliographiccitation.volume","119"],["dc.contributor.author","Purwar, R."],["dc.contributor.author","Wittmann, M."],["dc.contributor.author","Zwirner, Joerg"],["dc.contributor.author","Oppermann, Martin"],["dc.contributor.author","Kracht, Michael"],["dc.contributor.author","Dittrich-Breiholz, Oliver"],["dc.contributor.author","Gutzmer, Ralf"],["dc.contributor.author","Werfel, T."],["dc.date.accessioned","2018-11-07T11:06:45Z"],["dc.date.available","2018-11-07T11:06:45Z"],["dc.date.issued","2007"],["dc.format.extent","S203"],["dc.identifier.doi","10.1016/j.jaci.2006.12.166"],["dc.identifier.isi","000251460401185"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52391"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Mosby-elsevier"],["dc.publisher.place","New york"],["dc.relation.conference","63rd Annual Meeting of the American-Academy-of-Allergy-Asthma-and-Immunology"],["dc.relation.eventlocation","San Diego, CA"],["dc.relation.issn","1097-6825"],["dc.relation.issn","0091-6749"],["dc.title","Mast cell tryptase generate C3a from keratinocyte derived C3: Implication for allergic skin inflammation"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]