@article{AndreskaLueningschroerWolfetal.2023, author = {Andreska, Thomas and L{\"u}ningschr{\"o}r, Patrick and Wolf, Daniel and McFleder, Rhonda L. and Ayon-Olivas, Maurilyn and Rattka, Marta and Drechsler, Christine and Perschin, Veronika and Blum, Robert and Aufmkolk, Sarah and Granado, Noelia and Moratalla, Rosario and Sauer, Markus and Monoranu, Camelia and Volkmann, Jens and Ip, Chi Wang and Stigloher, Christian and Sendtner, Michael}, title = {DRD1 signaling modulates TrkB turnover and BDNF sensitivity in direct pathway striatal medium spiny neurons}, series = {Cell Reports}, volume = {42}, journal = {Cell Reports}, number = {6}, doi = {10.1016/j.celrep.2023.112575}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349932}, year = {2023}, abstract = {Highlights • Dopamine receptor-1 activation induces TrkB cell-surface expression in striatal neurons • Dopaminergic deficits cause TrkB accumulation and clustering in the ER • TrkB clusters colocalize with cargo receptor SORCS-2 in direct pathway striatal neurons • Intracellular TrkB clusters fail to fuse with lysosomes after dopamine depletion Summary Disturbed motor control is a hallmark of Parkinson's disease (PD). Cortico-striatal synapses play a central role in motor learning and adaption, and brain-derived neurotrophic factor (BDNF) from cortico-striatal afferents modulates their plasticity via TrkB in striatal medium spiny projection neurons (SPNs). We studied the role of dopamine in modulating the sensitivity of direct pathway SPNs (dSPNs) to BDNF in cultures of fluorescence-activated cell sorting (FACS)-enriched D1-expressing SPNs and 6-hydroxydopamine (6-OHDA)-treated rats. DRD1 activation causes enhanced TrkB translocation to the cell surface and increased sensitivity for BDNF. In contrast, dopamine depletion in cultured dSPN neurons, 6-OHDA-treated rats, and postmortem brain of patients with PD reduces BDNF responsiveness and causes formation of intracellular TrkB clusters. These clusters associate with sortilin related VPS10 domain containing receptor 2 (SORCS-2) in multivesicular-like structures, which apparently protects them from lysosomal degradation. Thus, impaired TrkB processing might contribute to disturbed motor function in PD.}, language = {en} } @article{PetersKaiserFinketal.2021, author = {Peters, Simon and Kaiser, Lena and Fink, Julian and Schumacher, Fabian and Perschin, Veronika and Schlegel, Jan and Sauer, Markus and Stigloher, Christian and Kleuser, Burkhard and Seibel, Juergen and Schubert-Unkmeir, Alexandra}, title = {Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-83813-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259147}, pages = {4300}, year = {2021}, abstract = {Sphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce 'click-AT-CLEM', a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.}, language = {en} }