@article{HartmannsbergerScribaGuidolinetal.2024, author = {Hartmannsberger, Beate and Scriba, Sabrina and Guidolin, Carolina and Becker, Juliane and Mehling, Katharina and Doppler, Kathrin and Sommer, Claudia and Rittner, Heike L.}, title = {Transient immune activation without loss of intraepidermal innervation and associated Schwann cells in patients with complex regional pain syndrome}, series = {Journal of Neuroinflammation}, volume = {21}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-023-02969-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357164}, year = {2024}, abstract = {Background Complex regional pain syndrome (CRPS) develops after injury and is characterized by disproportionate pain, oedema, and functional loss. CRPS has clinical signs of neuropathy as well as neurogenic inflammation. Here, we asked whether skin biopsies could be used to differentiate the contribution of these two systems to ultimately guide therapy. To this end, the cutaneous sensory system including nerve fibres and the recently described nociceptive Schwann cells as well as the cutaneous immune system were analysed. Methods We systematically deep-phenotyped CRPS patients and immunolabelled glabrous skin biopsies from the affected ipsilateral and non-affected contralateral finger of 19 acute (< 12 months) and 6 chronic (> 12 months after trauma) CRPS patients as well as 25 sex- and age-matched healthy controls (HC). Murine foot pads harvested one week after sham or chronic constriction injury were immunolabelled to assess intraepidermal Schwann cells. Results Intraepidermal Schwann cells were detected in human skin of the finger—but their density was much lower compared to mice. Acute and chronic CRPS patients suffered from moderate to severe CRPS symptoms and corresponding pain. Most patients had CRPS type I in the warm category. Their cutaneous neuroglial complex was completely unaffected despite sensory plus signs, e.g. allodynia and hyperalgesia. Cutaneous innate sentinel immune cells, e.g. mast cells and Langerhans cells, infiltrated or proliferated ipsilaterally independently of each other—but only in acute CRPS. No additional adaptive immune cells, e.g. T cells and plasma cells, infiltrated the skin. Conclusions Diagnostic skin punch biopsies could be used to diagnose individual pathophysiology in a very heterogenous disease like acute CRPS to guide tailored treatment in the future. Since numbers of inflammatory cells and pain did not necessarily correlate, more in-depth analysis of individual patients is necessary.}, language = {en} } @article{HeckerGruenerHartmannsbergeretal.2023, author = {Hecker, Katharina and Gr{\"u}ner, Julia and Hartmannsberger, Beate and Appeltshauser, Luise and Villmann, Carmen and Sommer, Claudia and Doppler, Kathrin}, title = {Different binding and pathogenic effect of neurofascin and contactin-1 autoantibodies in autoimmune nodopathies}, series = {Frontiers in Immunology}, volume = {14}, journal = {Frontiers in Immunology}, doi = {10.3389/fimmu.2023.1189734}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-320395}, year = {2023}, abstract = {Introduction IgG4 autoantibodies against paranodal proteins are known to induce acute-onset and often severe sensorimotor autoimmune neuropathies. How autoantibodies reach their antigens at the paranode in spite of the myelin barrier is still unclear. Methods We performed in vitro incubation experiments with patient sera on unfixed and unpermeabilized nerve fibers and in vivo intraneural and intrathecal passive transfer of patient IgG to rats, to explore the access of IgG autoantibodies directed against neurofascin-155 and contactin-1 to the paranodes and their pathogenic effect. Results We found that in vitro incubation resulted in weak paranodal binding of anti-contactin-1 autoantibodies whereas anti-neurofascin-155 autoantibodies bound to the nodes more than to the paranodes. After short-term intraneural injection, no nodal or paranodal binding was detectable when using anti-neurofascin-155 antibodies. After repeated intrathecal injections, nodal more than paranodal binding could be detected in animals treated with anti-neurofascin-155, accompanied by sensorimotor neuropathy. In contrast, no paranodal binding was visible in rats intrathecally injected with anti-contactin-1 antibodies, and animals remained unaffected. Conclusion These data support the notion of different pathogenic mechanisms of anti-neurofascin-155 and anti-contactin-1 autoantibodies and different accessibility of paranodal and nodal structures.}, language = {en} } @article{RauschenbergerPiroKasaragodetal.2023, author = {Rauschenberger, Vera and Piro, Inken and Kasaragod, Vikram Babu and H{\"o}rlin, Verena and Eckes, Anna-Lena and Kluck, Christoph J. and Schindelin, Hermann and Meinck, Hans-Michael and Wickel, Jonathan and Geis, Christian and T{\"u}z{\"u}n, Erdem and Doppler, Kathrin and Sommer, Claudia and Villmann, Carmen}, title = {Glycine receptor autoantibody binding to the extracellular domain is independent from receptor glycosylation}, series = {Frontiers in Molecular Neuroscience}, volume = {16}, journal = {Frontiers in Molecular Neuroscience}, doi = {10.3389/fnmol.2023.1089101}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304206}, year = {2023}, abstract = {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.}, language = {en} } @article{GarciaFernandezHoefflinRauschetal.2023, author = {Garc{\´i}a-Fern{\´a}ndez, Patricia and H{\"o}fflin, Klemens and Rausch, Antonia and Strommer, Katharina and Neumann, Astrid and Cebulla, Nadine and Reinhold, Ann-Kristin and Rittner, Heike and {\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia}, title = {Systemic inflammatory markers in patients with polyneuropathies}, series = {Frontiers in Immunology}, volume = {14}, journal = {Frontiers in Immunology}, doi = {10.3389/fimmu.2023.1067714}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304217}, year = {2023}, abstract = {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.}, language = {en} } @article{DopplerBrockmannSedghietal.2018, author = {Doppler, Kathrin and Brockmann, Kathrin and Sedghi, Annahita and Wurster, Isabel and Volkmann, Jens and Oertel, Wolfgang H. and Sommer, Claudia}, title = {Dermal phospho-alpha-synuclein deposition in patients with Parkinson's disease and mutation of the glucocerebrosidase gene}, series = {Frontiers in Neurology}, volume = {9}, journal = {Frontiers in Neurology}, doi = {10.3389/fneur.2018.01094}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222828}, year = {2018}, abstract = {Heterozygous mutations in the glucocerebrosidase gene (GBA1) represent the most common genetic risk factor for Parkinson's disease (PD) and are histopathologically associated with a widespread load of alpha-synuclein in the brain. Therefore, PD patients with GBA1 mutations are a cohort of high interest for clinical trials on disease-modifying therapies targeting alpha-synuclein. There is evidence that detection of phospho-alpha-synuclein (p-syn) in dermal nerve fibers might be a biomarker for the histopathological identification of PD patients even at premotor or very early stages of disease. It is so far unknown whether dermal p-syn deposition can also be found in PD patients with GBA1 mutations and may serve as a biomarker for PD in these patients. Skin biopsies of 10 PD patients with different GBA1 mutations (six N3705, three E326K, one L444P) were analyzed by double-immunofluorescence labeling with anti-p-syn and anti-protein gene product 9.5 (PGP9.5, axonal marker) to detect intraaxonal p-syn deposition. Four biopsy sites (distal, proximal leg, paravertebral Th10, and C7) per patient were studied. P-syn was found in six patients (three N370S, three E326K). P-syn deposition was mainly detected in autonomic nerve fibers, but also in somatosensory fibers and was not restricted to a certain GBA1 mutation. In summary, dermal p-syn in PD patients with GBA1 mutations seems to offer a similar distribution and frequency as observed in patients without a known mutation. Skin biopsy may be suitable to study p-syn deposition in these patients or even to identify premotor patients with GBA1 mutations.}, language = {en} }