TY - JOUR A1 - Rauschenberger, Vera A1 - Piro, Inken A1 - Kasaragod, Vikram Babu A1 - Hörlin, Verena A1 - Eckes, Anna-Lena A1 - Kluck, Christoph J. A1 - Schindelin, Hermann A1 - Meinck, Hans-Michael A1 - Wickel, Jonathan A1 - Geis, Christian A1 - Tüzün, Erdem A1 - Doppler, Kathrin A1 - Sommer, Claudia A1 - Villmann, Carmen T1 - Glycine receptor autoantibody binding to the extracellular domain is independent from receptor glycosylation JF - Frontiers in Molecular Neuroscience N2 - Glycine receptor (GlyR) autoantibodies are associated with stiff-person syndrome and the life-threatening progressive encephalomyelitis with rigidity and myoclonus in children and adults. Patient histories show variability in symptoms and responses to therapeutic treatments. A better understanding of the autoantibody pathology is required to develop improved therapeutic strategies. So far, the underlying molecular pathomechanisms include enhanced receptor internalization and direct receptor blocking altering GlyR function. A common epitope of autoantibodies against the GlyRα1 has been previously defined to residues 1A-33G at the N-terminus of the mature GlyR extracellular domain. However, if other autoantibody binding sites exist or additional GlyR residues are involved in autoantibody binding is yet unknown. The present study investigates the importance of receptor glycosylation for binding of anti-GlyR autoantibodies. The glycine receptor α1 harbors only one glycosylation site at the amino acid residue asparagine 38 localized in close vicinity to the identified common autoantibody epitope. First, non-glycosylated GlyRs were characterized using protein biochemical approaches as well as electrophysiological recordings and molecular modeling. Molecular modeling of non-glycosylated GlyRα1 did not show major structural alterations. Moreover, non-glycosylation of the GlyRα1N38Q did not prevent the receptor from surface expression. At the functional level, the non-glycosylated GlyR demonstrated reduced glycine potency, but patient GlyR autoantibodies still bound to the surface-expressed non-glycosylated receptor protein in living cells. Efficient adsorption of GlyR autoantibodies from patient samples was possible by binding to native glycosylated and non-glycosylated GlyRα1 expressed in living not fixed transfected HEK293 cells. Binding of patient-derived GlyR autoantibodies to the non-glycosylated GlyRα1 offered the possibility to use purified non-glycosylated GlyR extracellular domain constructs coated on ELISA plates and use them as a fast screening readout for the presence of GlyR autoantibodies in patient serum samples. Following successful adsorption of patient autoantibodies by GlyR ECDs, binding to primary motoneurons and transfected cells was absent. Our results indicate that the glycine receptor autoantibody binding is independent of the receptor’s glycosylation state. Purified non-glycosylated receptor domains harbouring the autoantibody epitope thus provide, an additional reliable experimental tool besides binding to native receptors in cell-based assays for detection of autoantibody presence in patient sera. KW - glycine receptor KW - autoantibodies KW - glycosylation KW - extracellular domain KW - adsorption Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304206 VL - 16 ER - TY - JOUR A1 - Andreska, Thomas A1 - Lüningschrör, Patrick A1 - Wolf, Daniel A1 - McFleder, Rhonda L. A1 - Ayon-Olivas, Maurilyn A1 - Rattka, Marta A1 - Drechsler, Christine A1 - Perschin, Veronika A1 - Blum, Robert A1 - Aufmkolk, Sarah A1 - Granado, Noelia A1 - Moratalla, Rosario A1 - Sauer, Markus A1 - Monoranu, Camelia A1 - Volkmann, Jens A1 - Ip, Chi Wang A1 - Stigloher, Christian A1 - Sendtner, Michael T1 - DRD1 signaling modulates TrkB turnover and BDNF sensitivity in direct pathway striatal medium spiny neurons JF - Cell Reports N2 - 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. KW - motor learning KW - cortico-striatal synapse KW - basal ganglia KW - direct pathway KW - DRD1 KW - dSPN KW - BDNF KW - TrkB KW - synaptic plasticity KW - GPCR Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349932 VL - 42 IS - 6 ER - TY - JOUR A1 - Grotemeyer, Alexander A1 - Fischer, Judith F. A1 - Koprich, James B. A1 - Brotchie, Jonathan M. A1 - Blum, Robert A1 - Volkmann, Jens A1 - Ip, Chi Wang T1 - Inflammasome inhibition protects dopaminergic neurons from α-synuclein pathology in a model of progressive Parkinson’s disease JF - Journal of Neuroinflammation N2 - Neuroinflammation has been suggested as a pathogenetic mechanism contributing to Parkinson’s disease (PD). However, anti-inflammatory treatment strategies have not yet been established as a therapeutic option for PD patients. We have used a human α-synuclein mouse model of progressive PD to examine the anti-inflammatory and neuroprotective effects of inflammasome inhibition on dopaminergic (DA) neurons in the substantia nigra (SN). As the NLRP3 (NOD-, LRR- and pyrin domain-containing 3)-inflammasome is a core interface for both adaptive and innate inflammation and is also highly druggable, we investigated the implications of its inhibition. Repeat administration of MCC950, an inhibitor of NLRP3, in a PD model with ongoing pathology reduced CD4\(^+\) and CD8\(^+\) T cell infiltration into the SN. Furthermore, the anti-inflammasome treatment mitigated microglial activation and modified the aggregation of α-synuclein protein in DA neurons. MCC950-treated mice showed significantly less neurodegeneration of DA neurons and a reduction in PD-related motor behavior. In summary, early inflammasome inhibition can reduce neuroinflammation and prevent DA cell death in an α-synuclein mouse model for progressive PD. KW - neurodegeneration KW - movement disorder KW - neuroinflammation KW - Parkinson’s disease KW - inflammasome KW - dopaminergic cells KW - NLRP3 KW - MCC950 KW - microglia KW - T cells Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357652 VL - 20 ER - TY - JOUR A1 - García-Fernández, Patricia A1 - Höfflin, Klemens A1 - Rausch, Antonia A1 - Strommer, Katharina A1 - Neumann, Astrid A1 - Cebulla, Nadine A1 - Reinhold, Ann-Kristin A1 - Rittner, Heike A1 - Üçeyler, Nurcan A1 - Sommer, Claudia T1 - Systemic inflammatory markers in patients with polyneuropathies JF - Frontiers in Immunology N2 - Introduction In patients with peripheral neuropathies (PNP), neuropathic pain is present in 50% of the cases, independent of the etiology. The pathophysiology of pain is poorly understood, and inflammatory processes have been found to be involved in neuro-degeneration, -regeneration and pain. While previous studies have found a local upregulation of inflammatory mediators in patients with PNP, there is a high variability described in the cytokines present systemically in sera and cerebrospinal fluid (CSF). We hypothesized that the development of PNP and neuropathic pain is associated with enhanced systemic inflammation. Methods To test our hypothesis, we performed a comprehensive analysis of the protein, lipid and gene expression of different pro- and anti-inflammatory markers in blood and CSF from patients with PNP and controls. Results While we found differences between PNP and controls in specific cytokines or lipids, such as CCL2 or oleoylcarnitine, PNP patients and controls did not present major differences in systemic inflammatory markers in general. IL-10 and CCL2 levels were related to measures of axonal damage and neuropathic pain. Lastly, we describe a strong interaction between inflammation and neurodegeneration at the nerve roots in a specific subgroup of PNP patients with blood-CSF barrier dysfunction. Conclusion In patients with PNP systemic inflammatory, markers in blood or CSF do not differ from controls in general, but specific cytokines or lipids do. Our findings further highlight the importance of CSF analysis in patients with peripheral neuropathies. KW - cytokines KW - polyneuropathy KW - cerebrospinal fluid KW - neurofilament light chain KW - blood CSF barrier Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304217 VL - 14 ER - TY - JOUR A1 - McFleder, Rhonda L. A1 - Makhotkina, Anastasiia A1 - Groh, Janos A1 - Keber, Ursula A1 - Imdahl, Fabian A1 - Peña Mosca, Josefina A1 - Peteranderl, Alina A1 - Wu, Jingjing A1 - Tabuchi, Sawako A1 - Hoffmann, Jan A1 - Karl, Ann-Kathrin A1 - Pagenstecher, Axel A1 - Vogel, Jörg A1 - Beilhack, Andreas A1 - Koprich, James B. A1 - Brotchie, Jonathan M. A1 - Saliba, Antoine-Emmanuel A1 - Volkmann, Jens A1 - Ip, Chi Wang T1 - Brain-to-gut trafficking of alpha-synuclein by CD11c\(^+\) cells in a mouse model of Parkinson’s disease JF - Nature Communications N2 - Inflammation in the brain and gut is a critical component of several neurological diseases, such as Parkinson’s disease (PD). One trigger of the immune system in PD is aggregation of the pre-synaptic protein, α-synuclein (αSyn). Understanding the mechanism of propagation of αSyn aggregates is essential to developing disease-modifying therapeutics. Using a brain-first mouse model of PD, we demonstrate αSyn trafficking from the brain to the ileum of male mice. Immunohistochemistry revealed that the ileal αSyn aggregations are contained within CD11c+ cells. Using single-cell RNA sequencing, we demonstrate that ileal CD11c\(^+\) cells are microglia-like and the same subtype of cells is activated in the brain and ileum of PD mice. Moreover, by utilizing mice expressing the photo-convertible protein, Dendra2, we show that CD11c\(^+\) cells traffic from the brain to the ileum. Together these data provide a mechanism of αSyn trafficking between the brain and gut. KW - antigen-presenting cells KW - neuroimmunology KW - Parkinson's disease Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357696 VL - 14 ER - TY - JOUR A1 - Griebel, Matthias A1 - Segebarth, Dennis A1 - Stein, Nikolai A1 - Schukraft, Nina A1 - Tovote, Philip A1 - Blum, Robert A1 - Flath, Christoph M. T1 - Deep learning-enabled segmentation of ambiguous bioimages with deepflash2 JF - Nature Communications N2 - Bioimages frequently exhibit low signal-to-noise ratios due to experimental conditions, specimen characteristics, and imaging trade-offs. Reliable segmentation of such ambiguous images is difficult and laborious. Here we introduce deepflash2, a deep learning-enabled segmentation tool for bioimage analysis. The tool addresses typical challenges that may arise during the training, evaluation, and application of deep learning models on ambiguous data. The tool’s training and evaluation pipeline uses multiple expert annotations and deep model ensembles to achieve accurate results. The application pipeline supports various use-cases for expert annotations and includes a quality assurance mechanism in the form of uncertainty measures. Benchmarked against other tools, deepflash2 offers both high predictive accuracy and efficient computational resource usage. The tool is built upon established deep learning libraries and enables sharing of trained model ensembles with the research community. deepflash2 aims to simplify the integration of deep learning into bioimage analysis projects while improving accuracy and reliability. KW - machine learning KW - microscopy KW - quality control KW - software Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357286 VL - 14 ER - TY - JOUR A1 - Ip, Chi Wang A1 - Wischhusen, Jörg T1 - Versatile guardians: regenerative regulatory T cells in Parkinson’s disease rodent models JF - Signal Transduction and Targeted Therapy N2 - No abstract available. KW - diseases of the nervous system KW - neuroimmunology KW - neurological disorders Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357674 VL - 8 ER - TY - JOUR A1 - García-Fernández, Patricia A1 - Reinhold, Colette A1 - Üçeyler, Nurcan A1 - Sommer, Claudia T1 - Local inflammatory mediators involved in neuropathic pain JF - International Journal of Molecular Sciences N2 - Polyneuropathy (PNP) is a term to describe diseases of the peripheral nervous system, 50% of which present with neuropathic pain. In some types of PNP, pain is restricted to the skin distally in the leg, suggesting a local regulatory process leading to pain. In this study, we proposed a pro-inflammatory pathway mediated by NF-κB that might be involved in the development of pain in patients with painful PNP. To test this hypothesis, we have collected nerve and skin samples from patients with different etiologies and levels of pain. We performed RT-qPCR to analyze the gene expression of the proposed inflammatory pathway components in sural nerve and in distal and proximal skin samples. In sural nerve, we showed a correlation of TLR4 and TNFα to neuropathic pain, and an upregulation of TNFα in patients with severe pain. Patients with an inflammatory PNP also presented a lower expression of TRPV1 and SIRT1. In distal skin, we found a reduced expression of TLR4 and miR-146-5p, in comparison to proximal skin. Our findings thus support our hypothesis of local inflammatory processes involved in pain in PNP, and further show disturbed anti-inflammatory pathways involving TRPV1 and SIRT1 in inflammatory PNP. KW - polyneuropathy KW - pain KW - inflammation KW - NF-κB KW - TNFα Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313613 SN - 1422-0067 VL - 24 IS - 9 ER - TY - JOUR A1 - Kuzkina, A. A1 - Rößle, J. A1 - Seger, A. A1 - Panzer, C. A1 - Kohl, A. A1 - Maltese, V. A1 - Musacchio, T. A1 - Blaschke, S. J. A1 - Tamgüney, G. A1 - Kaulitz, S. A1 - Rak, K. A1 - Scherzad, A. A1 - Zimmermann, P. H. A1 - Klussmann, J. P. A1 - Hackenberg, S. A1 - Volkmann, J. A1 - Sommer, C. A1 - Sommerauer, M. A1 - Doppler, K. T1 - Combining skin and olfactory α-synuclein seed amplification assays (SAA)—towards biomarker-driven phenotyping in synucleinopathies JF - npj Parkinson’s Disease N2 - Seed amplification assays (SAA) are becoming commonly used in synucleinopathies to detect α-synuclein aggregates. Studies in Parkinson’s disease (PD) and isolated REM-sleep behavior disorder (iRBD) have shown a considerably lower sensitivity in the olfactory epithelium than in CSF or skin. To get an insight into α-synuclein (α-syn) distribution within the nervous system and reasons for low sensitivity, we compared SAA assessment of nasal brushings and skin biopsies in PD (n = 27) and iRBD patients (n = 18) and unaffected controls (n = 30). α-syn misfolding was overall found less commonly in the olfactory epithelium than in the skin, which could be partially explained by the nasal brushing matrix exerting an inhibitory effect on aggregation. Importantly, the α-syn distribution was not uniform: there was a higher deposition of misfolded α-syn across all sampled tissues in the iRBD cohort compared to PD (supporting the notion of RBD as a marker of a more malignant subtype of synucleinopathy) and in a subgroup of PD patients, misfolded α-syn was detectable only in the olfactory epithelium, suggestive of the recently proposed brain-first PD subtype. Assaying α-syn of diverse origins, such as olfactory (part of the central nervous system) and skin (peripheral nervous system), could increase diagnostic accuracy and allow better stratification of patients. KW - diagnostic markers KW - Parkinson's disease Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357687 SN - 2373-8057 VL - 9 ER - TY - JOUR A1 - Odorfer, Thorsten M. A1 - Yabe, Marie A1 - Hiew, Shawn A1 - Volkmann, Jens A1 - Zeller, Daniel T1 - Topological differences and confounders of mental rotation in cervical dystonia and blepharospasm JF - Scientific Reports N2 - Mental rotation (mR) bases on imagination of actual movements. It remains unclear whether there is a specific pattern of mR impairment in focal dystonia. We aimed to investigate mR in patients with cervical dystonia (CD) and blepharospasm (BS) and to assess potential confounders. 23 CD patients and 23 healthy controls (HC) as well as 21 BS and 19 hemifacial spasm (HS) patients were matched for sex, age, and education level. Handedness, finger dexterity, general reaction time, and cognitive status were assessed. Disease severity was evaluated by clinical scales. During mR, photographs of body parts (head, hand, or foot) and a non-corporal object (car) were displayed at different angles rotated within their plane. Subjects were asked to judge laterality of the presented image by keystroke. Both speed and correctness were evaluated. Compared to HC, CD and HS patients performed worse in mR of hands, whereas BS group showed comparable performance. There was a significant association of prolonged mR reaction time (RT) with reduced MoCA scores and with increased RT in an unspecific reaction speed task. After exclusion of cognitively impaired patients, increased RT in the mR of hands was confined to CD group, but not HS. While the question of whether specific patterns of mR impairment reliably define a dystonic endophenotype remains elusive, our findings point to mR as a useful tool, when used carefully with control measures and tasks, which may be capable of identifying specific deficits that distinguish between subtypes of dystonia. KW - neurology KW - neuroscience Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357713 VL - 13 ER -