@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{GmachBathePetersTeluguetal.2022, author = {Gmach, Philipp and Bathe-Peters, Marc and Telugu, Narasimha and Miller, Duncan C. and Annibale, Paolo}, title = {Fluorescence spectroscopy of low-level endogenous β-adrenergic receptor expression at the plasma membrane of differentiating human iPSC-derived cardiomyocytes}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {18}, issn = {1422-0067}, doi = {10.3390/ijms231810405}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288277}, year = {2022}, abstract = {The potential of human-induced pluripotent stem cells (hiPSCs) to be differentiated into cardiomyocytes (CMs) mimicking adult CMs functional morphology, marker genes and signaling characteristics has been investigated since over a decade. The evolution of the membrane localization of CM-specific G protein-coupled receptors throughout differentiation has received, however, only limited attention to date. We employ here advanced fluorescent spectroscopy, namely linescan Fluorescence Correlation Spectroscopy (FCS), to observe how the plasma membrane abundance of the β\(_1\)- and β\(_2\)-adrenergic receptors (β\(_{1/2}\)-ARs), labelled using a bright and photostable fluorescent antagonist, evolves during the long-term monolayer culture of hiPSC-derived CMs. We compare it to the kinetics of observed mRNA levels in wildtype (WT) hiPSCs and in two CRISPR/Cas9 knock-in clones. We conduct these observations against the backdrop of our recent report of cell-to-cell expression variability, as well as of the subcellular localization heterogeneity of β-ARs in adult CMs.}, language = {en} } @article{MaiellaroLohseKitteetal.2016, author = {Maiellaro, Isabella and Lohse, Martin J. and Kitte, Robert J. and Calebiro, Davide}, title = {cAMP Signals in Drosophila Motor Neurons Are Confined to Single Synaptic Boutons}, series = {Cell Reports}, volume = {17}, journal = {Cell Reports}, number = {5}, doi = {10.1016/j.celrep.2016.09.090}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162324}, pages = {1238-1246}, year = {2016}, abstract = {The second messenger cyclic AMP (cAMP) plays an important role in synaptic plasticity. Although there is evidence for local control of synaptic transmission and plasticity, it is less clear whether a similar spatial confinement of cAMP signaling exists. Here, we suggest a possible biophysical basis for the site-specific regulation of synaptic plasticity by cAMP, a highly diffusible small molecule that transforms the physiology of synapses in a local and specific manner. By exploiting the octopaminergic system of Drosophila, which mediates structural synaptic plasticity via a cAMP-dependent pathway, we demonstrate the existence of local cAMP signaling compartments of micrometer dimensions within single motor neurons. In addition, we provide evidence that heterogeneous octopamine receptor localization, coupled with local differences in phosphodiesterase activity, underlies the observed differences in cAMP signaling in the axon, cell body, and boutons.}, language = {en} }