@article{WeineltKarathanasisSmithetal.2021, author = {Weinelt, Nadine and Karathanasis, Christos and Smith, Sonja and Medler, Juliane and Malkusch, Sebastian and Fulda, Simone and Wajant, Harald and Heilemann, Mike and van Wijk, Sjoerd J. L.}, title = {Quantitative single-molecule imaging of TNFR1 reveals zafirlukast as antagonist of TNFR1 clustering and TNFα-induced NF-ĸB signaling}, series = {Journal of Leukocyte Biology}, volume = {109}, journal = {Journal of Leukocyte Biology}, number = {2}, doi = {10.1002/JLB.2AB0420-572RR}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215960}, pages = {363 -- 371}, year = {2021}, abstract = {TNFR1 is a crucial regulator of NF-ĸB-mediated proinflammatory cell survival responses and programmed cell death (PCD). Deregulation of TNFα- and TNFR1-controlled NF-ĸB signaling underlies major diseases, like cancer, inflammation, and autoimmune diseases. Therefore, although being routinely used, antagonists of TNFα might also affect TNFR2-mediated processes, so that alternative approaches to directly antagonize TNFR1 are beneficial. Here, we apply quantitative single-molecule localization microscopy (SMLM) of TNFR1 in physiologic cellular settings to validate and characterize TNFR1 inhibitory substances, exemplified by the recently described TNFR1 antagonist zafirlukast. Treatment of TNFR1-mEos2 reconstituted TNFR1/2 knockout mouse embryonic fibroblasts (MEFs) with zafirlukast inhibited both ligand-independent preligand assembly domain (PLAD)-mediated TNFR1 dimerization as well as TNFα-induced TNFR1 oligomerization. In addition, zafirlukast-mediated inhibition of TNFR1 clustering was accompanied by deregulation of acute and prolonged NF-ĸB signaling in reconstituted TNFR1-mEos2 MEFs and human cervical carcinoma cells. These findings reveal the necessity of PLAD-mediated, ligand-independent TNFR1 dimerization for NF-ĸB activation, highlight the PLAD as central regulator of TNFα-induced TNFR1 oligomerization, and demonstrate that TNFR1-mEos2 MEFs can be used to investigate TNFR1-antagonizing compounds employing single-molecule quantification and functional NF-ĸB assays at physiologic conditions.}, language = {en} } @article{EngelRudeliusSlawskaetal.2016, author = {Engel, Katharina and Rudelius, Martina and Slawska, Jolanta and Jacobs, Laura and Abhari, Behnaz Ahangarian and Altmann, Bettina and Kurutz, Julia and Rathakrishnan, Abirami and Fern{\´a}ndez-S{\´a}iz, Vanesa and Brunner, Andr{\"a} and Targosz, Bianca-Sabrina and Loewecke, Felicia and Gloeckner, Christian Johannes and Ueffing, Marius and Fulda, Simone and Pfreundschuh, Michael and Tr{\"u}mper, Lorenz and Klapper, Wolfram and Keller, Ulrich and Jost, Philipp J. and Rosenwald, Andreas and Peschel, Christian and Bassermann, Florian}, title = {USP9X stabilizes XIAP to regulate mitotic cell death and chemoresistance in aggressive B-cell lymphoma}, series = {EMBO Molecular Medicine}, volume = {8}, journal = {EMBO Molecular Medicine}, doi = {10.15252/emmm.201506047}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165016}, pages = {851-862}, year = {2016}, abstract = {The mitotic spindle assembly checkpoint (SAC) maintains genome stability and marks an important target for antineoplastic therapies. However, it has remained unclear how cells execute cell fate decisions under conditions of SAC-induced mitotic arrest. Here, we identify USP9X as the mitotic deubiquitinase of the X-linked inhibitor of apoptosis protein (XIAP) and demonstrate that deubiquitylation and stabilization of XIAP by USP9X lead to increased resistance toward mitotic spindle poisons. We find that primary human aggressive B-cell lymphoma samples exhibit high USP9X expression that correlate with XIAP overexpression. We show that high USP9X/XIAP expression is associated with shorter event-free survival in patients treated with spindle poison-containing chemotherapy. Accordingly, aggressive B-cell lymphoma lines with USP9X and associated XIAP overexpression exhibit increased chemoresistance, reversed by specific inhibition of either USP9X or XIAP. Moreover, knockdown of USP9X or XIAP significantly delays lymphoma development and increases sensitivity to spindle poisons in a murine Eμ-Myc lymphoma model. Together, we specify the USP9X-XIAP axis as a regulator of the mitotic cell fate decision and propose that USP9X and XIAP are potential prognostic biomarkers and therapeutic targets in aggressive B-cell lymphoma.}, language = {en} }