@article{GruenewaldBennettToykaetal.2016,
  author    = {Gr{\"u}newald, Benedikt and Bennett, Jeffrey L. and Toyka, Klaus V. and Sommer, Claudia and Geis, Christian},
  title     = {Efficacy of Polyvalent Human Immunoglobulins in an Animal Model of Neuromyelitis Optica Evoked by Intrathecal Anti-Aquaporin 4 Antibodies},
  series = {International Journal of Molecular Sciences},
  volume    = {17},
  journal   = {International Journal of Molecular Sciences},
  number    = {9},
  doi       = {10.3390/ijms17091407},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166000},
  pages     = {1407},
  year      = {2016},
  abstract  = {Neuromyelitis Optica Spectrum Disorders (NMOSD) are associated with autoantibodies (ABs) targeting the astrocytic aquaporin-4 water channels (AQP4-ABs). These ABs have a direct pathogenic role by initiating a variety of immunological and inflammatory processes in the course of disease. In a recently-established animal model, chronic intrathecal passive-transfer of immunoglobulin G from NMOSD patients (NMO-IgG), or of recombinant human AQP4-ABs (rAB-AQP4), provided evidence for complementary and immune-cell independent effects of AQP4-ABs. Utilizing this animal model, we here tested the effects of systemically and intrathecally applied pooled human immunoglobulins (IVIg) using a preventive and a therapeutic paradigm. In NMO-IgG animals, prophylactic application of systemic IVIg led to a reduced median disease score of 2.4 on a 0-10 scale, in comparison to 4.1 with sham treatment. Therapeutic IVIg, applied systemically after the 10th intrathecal NMO-IgG injection, significantly reduced the disease score by 0.8. Intrathecal IVIg application induced a beneficial effect in animals with NMO-IgG (median score IVIg 1.6 vs. sham 3.7) or with rAB-AQP4 (median score IVIg 2.0 vs. sham 3.7). We here provide evidence that treatment with IVIg ameliorates disease symptoms in this passive-transfer model, in analogy to former studies investigating passive-transfer animal models of other antibody-mediated disorders.},
  language  = {en}
}
@article{EvdokimovDinkelFranketal.2020,
  author    = {Evdokimov, Dimitar and Dinkel, Philine and Frank, Johanna and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Characterization of dermal skin innervation in fibromyalgia syndrome},
  series = {PLoS One},
  volume    = {15},
  journal   = {PLoS One},
  number    = {1},
  doi       = {10.1371/journal.pone.0227674},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229299},
  year      = {2020},
  abstract  = {Introduction We characterized dermal innervation in patients with fibromyalgia syndrome (FMS) as potential contribution to small fiber pathology. Methods Skin biopsies of the calf were collected (86 FMS patients, 35 healthy controls). Skin was immunoreacted with antibodies against protein gene product 9.5, calcitonine gene-related peptide, substance P, CD31, and neurofilament 200 for small fiber subtypes. We assessed two skin sections per patient; on each skin section, two dermal areas (150 x 700 mu m each) were investigated for dermal nerve fiber length (DNFL). Results In FMS patients we found reduced DNFL of fibers with vessel contact compared to healthy controls (p<0.05). There were no differences for the other nerve fiber subtypes. Discussion We found less dermal nerve fibers in contact with blood vessels in FMS patients than in controls. The pathophysiological relevance of this finding is unclear, but we suggest the possibility of a relationship with impaired thermal tolerance commonly reported by FMS patients.},
  language  = {en}
}
@article{ReinholdKrugSalvadoretal.2022,
  author    = {Reinhold, Ann Kristin and Krug, Susanne M. and Salvador, Ellaine and Sauer, Reine S. and Karl-Sch{\"o}ller, Franziska and Malcangio, Marzia and Sommer, Claudia and Rittner, Heike L.},
  title     = {MicroRNA-21-5p functions via RECK/MMP9 as a proalgesic regulator of the blood nerve barrier in nerve injury},
  series = {Annals of the New York Academy of Sciences},
  volume    = {1515},
  journal   = {Annals of the New York Academy of Sciences},
  number    = {1},
  doi       = {10.1111/nyas.14816},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318226},
  pages     = {184 -- 195},
  year      = {2022},
  abstract  = {Both nerve injury and complex regional pain syndrome (CRPS) can result in chronic pain. In traumatic neuropathy, the blood nerve barrier (BNB) shielding the nerve is impaired—partly due to dysregulated microRNAs (miRNAs). Upregulation of microRNA-21-5p (miR-21) has previously been documented in neuropathic pain, predominantly due to its proinflammatory features. However, little is known about other functions. Here, we characterized miR-21 in neuropathic pain and its impact on the BNB in a human-murine back translational approach. MiR-21 expression was elevated in plasma of patients with CRPS as well as in nerves of mice after transient and persistent nerve injury. Mice presented with BNB leakage, as well as loss of claudin-1 in both injured and spared nerves. Moreover, the putative miR-21 target RECK was decreased and downstream Mmp9 upregulated, as was Tgfb. In vitro experiments in human epithelial cells confirmed a downregulation of CLDN1 by miR-21 mimics via inhibition of the RECK/MMP9 pathway but not TGFB. Perineurial miR-21 mimic application in mice elicited mechanical hypersensitivity, while local inhibition of miR-21 after nerve injury reversed it. In summary, the data support a novel role for miR-21, independent of prior inflammation, in elicitation of pain and impairment of the BNB via RECK/MMP9.},
  language  = {en}
}
@article{PetzkeKloseWelschetal.2020,
  author    = {Petzke, Frank and Klose, Petra and Welsch, Patrick and Sommer, Claudia and H{\"a}user, Winfried},
  title     = {Opioids for chronic low back pain: An updated systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks of double-blind duration},
  series = {European Journal of Pain},
  volume    = {24},
  journal   = {European Journal of Pain},
  number    = {3},
  doi       = {10.1002/ejp.1519},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218498},
  pages     = {497 -- 517},
  year      = {2020},
  abstract  = {Background and Objective This updated systematic review evaluated the efficacy, tolerability and safety of opioids compared to placebo in non-malignant chronic low back pain. Databases and Data Treatment Clinicaltrials.gov, CENTRAL, MEDLINE and PsycINFO were searched from October 2013 to May 2019. Randomized controlled trials comparing opioids with placebo and at least 4 weeks of double-blinded duration were analysed. Primary outcomes were pain relief of 50\% or greater, disability, tolerability and safety. Effects were summarized by a random effects model using risk differences or standardized mean differences. We added nine new studies with 2,980 participants for a total of 21 studies with 7,650 participants. Study duration ranged between 4 and 15 weeks. Studies with a parallel and cross-over design: Based on very low to low-quality evidence, opioids provided no clinically relevant pain relief of 50\% or greater, but a clinically relevant reduction of disability compared to placebo. Enriched enrolment randomized withdrawal (EERW) design: Based on very low to low-quality evidence, opioids provided a clinically relevant pain relief of 50\% or greater, but not a clinically relevant reduction of disability compared to placebo. There was no clinically relevant harm with regard to serious adverse events by opioids compared to placebo in studies with parallel/cross-over and EERW design. There was a relevant harm with regard to drop out rates due to adverse events in studies with parallel/cross-over, but not in studies with EERW design. Conclusions Opioids may provide a safe and clinically relevant pain relief for 4-15 weeks in highly selected patients. Significance Within the context of randomized controlled trials of 4-15 weeks, opioids provided a clinically relevant pain relief of 30\% or greater and a clinically relevant reduction of disability compared to placebo in non-malignant chronic low back pain. Number needed to treat for an additional drop out due to side effects was 11 (95\% confidence interval: 6-33). Assessment of abuse and addiction was incomplete. The frequency of serious adverse events including deaths did not differ from placebo.},
  language  = {en}
}
@article{StengelVuralBrunderetal.2019,
  author    = {Stengel, Helena and Vural, Atay and Brunder, Anna-Michelle and Heinius, Annika and Appeltshauser, Luise and Fiebig, Bianca and Giese, Florian and Dresel, Christian and Papagianni, Aikaterini and Birklein, Frank and Weis, Joachim and Huchtemann, Tessa and Schmidt, Christian and K{\"o}rtvelyessy, Peter and Villmann, Carmen and Meinl, Edgar and Sommer, Claudia and Leypoldt, Frank and Doppler, Kathrin},
  title     = {Anti-pan-neurofascin IgG3 as a marker of fulminant autoimmune neuropathy},
  series = {Neurology: Neuroimmunology \& Neuroinflammation},
  volume    = {6},
  journal   = {Neurology: Neuroimmunology \& Neuroinflammation},
  number    = {5},
  doi       = {10.1212/NXI.0000000000000603},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202462},
  year      = {2019},
  abstract  = {Objective To identify and characterize patients with autoantibodies against different neurofascin (NF) isoforms. Methods Screening of a large cohort of patient sera for anti-NF autoantibodies by ELISA and further characterization by cell-based assays, epitope mapping, and complement binding assays. Results Two different clinical phenotypes became apparent in this study: The well-known clinical picture of subacute-onset severe sensorimotor neuropathy with tremor that is known to be associated with IgG4 autoantibodies against the paranodal isoform NF-155 was found in 2 patients. The second phenotype with a dramatic course of disease with tetraplegia and almost locked-in syndrome was associated with IgG3 autoantibodies against nodal and paranodal isoforms of NF in 3 patients. The epitope against which these autoantibodies were directed in this second phenotype was the common Ig domain found in all 3 NF isoforms. In contrast, anti-NF-155 IgG4 were directed against the NF-155-specific Fn3Fn4 domain. The description of a second phenotype of anti-NF-associated neuropathy is in line with some case reports of similar patients that were published in the last year. Conclusions Our results indicate that anti-pan-NF-associated neuropathy differs from anti-NF-155-associated neuropathy, and epitope and subclass play a major role in the pathogenesis and severity of anti-NF-associated neuropathy and should be determined to correctly classify patients, also in respect to possible differences in therapeutic response.},
  language  = {en}
}
@article{EvdokimovFrankKlitschetal.2019,
  author    = {Evdokimov, Dimitar and Frank, Johanna and Klitsch, Alexander and Unterecker, Stefan and Warrings, Bodo and Serra, Jordi and Papagianni, Aikaterini and Saffer, Nadine and Meyer zu Altenschildesche, Caren and Kampik, Daniel and Malik, Rayaz A. and Sommer, Claudia and {\"U}ceyler, Nurcan},
  title     = {Reduction of skin innervation is associated with a severe fibromyalgia phenotype},
  series = {Annals of Neurology},
  volume    = {86},
  journal   = {Annals of Neurology},
  number    = {4},
  doi       = {10.1002/ana.25565},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206168},
  pages     = {504-516},
  year      = {2019},
  abstract  = {Objective: To assess patterns and impact of small nerve fiber dysfunction and pathology in patients with fibromyalgia syndrome (FMS). Methods: One hundred seventeen women with FMS underwent neurological examination, questionnaire assessment, neurophysiology assessment, and small fiber tests: skin punch biopsy, corneal confocal microscopy, microneurography, quantitative sensory testing including C-tactile afferents, and pain-related evoked potentials. Data were compared with those of women with major depressive disorder and chronic widespread pain (MD-P) and healthy women. Results: Intraepidermal nerve fiber density (IENFD) was reduced at different biopsy sites in 63\% of FMS patients (MDP: 10\%, controls: 18\%; p < 0.001 for each). We found 4 patterns of skin innervation in FMS: normal, distally reduced, proximally reduced, and both distally and proximally reduced (p < 0.01 for each compared to controls). Microneurography revealed initial activity-dependent acceleration of conduction velocity upon low frequencies of stimulation in 1A fibers, besides 1B fiber spontaneous activity and mechanical sensitization in FMS patients. FMS patients had elevated warm detection thresholds (p < 0.01), impaired C-tactile afferents (p < 0.05), and reduced amplitudes (p < 0.001) of pain-related evoked potentials compared to controls. Compared to FMS patients with normal skin innervation, those with generalized IENFD reduction had higher pain intensity and impairment due to pain, higher disease burden, more stabbing pain and paresthesias, and more anxiety (p < 0.05 for each). FMS patients with generalized IENFD reduction also had lower corneal nerve fiber density (p < 0.01) and length (p < 0.05). Interpretation: The extent of small fiber pathology is related to symptom severity in FMS. This knowledge may have implications for the diagnostic classification and treatment of patients with FMS.},
  language  = {en}
}
@article{KlitschEvdokimovFranketal.2020,
  author    = {Klitsch, Alexander and Evdokimov, Dimitar and Frank, Johanna and Thomas, Dominique and Saffer, Nadine and Meyer zu Altenschildesche, Caren and Sisignano, Marco and Kampik, Daniel and Malik, Rayaz A. and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Reduced association between dendritic cells and corneal sub-basal nerve fibers in patients with fibromyalgia syndrome},
  series = {Journal of the Peripheral Nervous System},
  volume    = {25},
  journal   = {Journal of the Peripheral Nervous System},
  number    = {1},
  doi       = {10.1111/jns.12360},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214150},
  pages     = {9-18},
  year      = {2020},
  abstract  = {In our study, we aimed at investigating corneal langerhans cells (LC) in patients with fibromyalgia syndrome (FMS) and small fiber neuropathy (SFN) as potential contributors to corneal small fiber pathology. We enrolled women with FMS (n = 134) and SFN (n = 41) who underwent neurological examination, neurophysiology, prostaglandin analysis in tear fluid, and corneal confocal microscopy (CCM). Data were compared with those of 60 age-matched female controls. After screening for dry eye disease, corneal LC were counted and sub-classified as dendritic (dLC) and non-dendritic (ndLC) cells with or without nerve fiber association. We further analyzed corneal nerve fiber density (CNFD), length (CNFL), and branch density (CNBD). Neurological examination indicated deficits of small fiber function in patients with SFN. Nerve conduction studies were normal in all participants. Dry eye disease was more prevalent in FMS (17\%) and SFN (28\%) patients than in controls (5\%). Tear fluid prostaglandin levels did not differ between FMS patients and controls. While corneal LC density in FMS and SFN patients was not different from controls, there were fewer dLC in association with nerve fibers in FMS and SFN patients than in controls (P < .01 each). Compared to controls, CNFL was lower in FMS and SFN patients (P < .05 each), CNFD was lower only in FMS patients (P < .05), and CNBD was lower only in SFN patients (P < .001). There was no difference in any CCM parameter between patients with and without dry eyes. Our data indicate changes in corneal innervation and LC distribution in FMS and SFN, potentially based on altered LC signaling.},
  language  = {en}
}
@article{HofmannKarlSommeretal.2017,
  author    = {Hofmann, Lukas and Karl, Franziska and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Affective and cognitive behavior in the alpha-galactosidase A deficient mouse model of Fabry disease},
  series = {PLoS ONE},
  volume    = {12},
  journal   = {PLoS ONE},
  number    = {6},
  doi       = {10.1371/journal.pone.0180601},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170745},
  pages     = {e0180601},
  year      = {2017},
  abstract  = {Fabry disease is an X-linked inherited lysosomal storage disorder with intracellular accumulation of globotriaosylceramide (Gb3) due to α-galactosidase A (α-Gal A) deficiency. Fabry patients frequently report of anxiety, depression, and impaired cognitive function. We characterized affective and cognitive phenotype of male mice with α-Gal A deficiency (Fabry KO) and compared results with those of age-matched male wildtype (WT) littermates. Young (3 months) and old (≥ 18 months) mice were tested in the na{\"i}ve state and after i.pl. injection of complete Freund`s adjuvant (CFA) as an inflammatory pain model. We used the elevated plus maze (EPM), the light-dark box (LDB) and the open field test (OF) to investigate anxiety-like behavior. The forced swim test (FST) and Morris water maze (MWM) were applied to assess depressive-like and learning behavior. The EPM test revealed no intergroup difference for anxiety-like behavior in na{\"i}ve young and old Fabry KO mice compared to WT littermates, except for longer time spent in open arms of the EPM for young WT mice compared to young Fabry KO mice (p<0.05). After CFA injection, young Fabry KO mice showed increased anxiety-like behavior compared to young WT littermates (p<0.05) and na{\"i}ve young Fabry KO mice (p<0.05) in the EPM as reflected by shorter time spent in EPM open arms. There were no relevant differences in the LDB and the OF test, except for longer time spent in the center zone of the OF by young WT mice compared to young Fabry KO mice (p<0.05). Complementary to this, depression-like and learning behavior were not different between genotypes and age-groups, except for the expectedly lower memory performance in older age-groups compared to young mice. Our results indicate that genetic influences on affective and cognitive symptoms in FD may be of subordinate relevance, drawing attention to potential influences of environmental and epigenetic factors.},
  language  = {en}
}
@article{PiroEckesKasaragodetal.2021,
  author    = {Piro, Inken and Eckes, Anna-Lena and Kasaragod, Vikram Babu and Sommer, Claudia and Harvey, Robert J. and Schaefer, Natascha and Villmann, Carmen},
  title     = {Novel Functional Properties of Missense Mutations in the Glycine Receptor β Subunit in Startle Disease},
  series = {Frontiers in Molecular Neuroscience},
  volume    = {14},
  journal   = {Frontiers in Molecular Neuroscience},
  issn      = {1662-5099},
  doi       = {10.3389/fnmol.2021.745275},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246676},
  year      = {2021},
  abstract  = {Startle disease is a rare disorder associated with mutations in GLRA1 and GLRB, encoding glycine receptor (GlyR) α1 and β subunits, which enable fast synaptic inhibitory transmission in the spinal cord and brainstem. The GlyR β subunit is important for synaptic localization via interactions with gephyrin and contributes to agonist binding and ion channel conductance. Here, we have studied three GLRB missense mutations, Y252S, S321F, and A455P, identified in startle disease patients. For Y252S in M1 a disrupted stacking interaction with surrounding aromatic residues in M3 and M4 is suggested which is accompanied by an increased EC\(_{50}\) value. By contrast, S321F in M3 might stabilize stacking interactions with aromatic residues in M1 and M4. No significant differences in glycine potency or efficacy were observed for S321F. The A455P variant was not predicted to impact on subunit folding but surprisingly displayed increased maximal currents which were not accompanied by enhanced surface expression, suggesting that A455P is a gain-of-function mutation. All three GlyR β variants are trafficked effectively with the α1 subunit through intracellular compartments and inserted into the cellular membrane. In vivo, the GlyR β subunit is transported together with α1 and the scaffolding protein gephyrin to synaptic sites. The interaction of these proteins was studied using eGFP-gephyrin, forming cytosolic aggregates in non-neuronal cells. eGFP-gephyrin and β subunit co-expression resulted in the recruitment of both wild-type and mutant GlyR β subunits to gephyrin aggregates. However, a significantly lower number of GlyR β aggregates was observed for Y252S, while for mutants S321F and A455P, the area and the perimeter of GlyR β subunit aggregates was increased in comparison to wild-type β. Transfection of hippocampal neurons confirmed differences in GlyR-gephyrin clustering with Y252S and A455P, leading to a significant reduction in GlyR β-positive synapses. Although none of the mutations studied is directly located within the gephyrin-binding motif in the GlyR β M3-M4 loop, we suggest that structural changes within the GlyR β subunit result in differences in GlyR β-gephyrin interactions. Hence, we conclude that loss- or gain-of-function, or alterations in synaptic GlyR clustering may underlie disease pathology in startle disease patients carrying GLRB mutations.},
  language  = {en}
}
@article{WagenhaeuserRickertSommeretal.2022,
  author    = {Wagenh{\"a}user, Laura and Rickert, Vanessa and Sommer, Claudia and Wanner, Christoph and Nordbeck, Peter and Rost, Simone and {\"U}{\c{c}}eyler, Nurcan},
  title     = {X-chromosomal inactivation patterns in women with Fabry disease},
  series = {Molecular Genetics \& Genomic Medicine},
  volume    = {10},
  journal   = {Molecular Genetics \& Genomic Medicine},
  number    = {9},
  doi       = {10.1002/mgg3.2029},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312795},
  year      = {2022},
  abstract  = {Background Although Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene (GLA), women may develop severe symptoms. We investigated X-chromosomal inactivation patterns (XCI) as a potential determinant of symptom severity in FD women. Patients and Methods We included 95 women with mutations in GLA (n = 18 with variants of unknown pathogenicity) and 50 related men, and collected mouth epithelial cells, venous blood, and skin fibroblasts for XCI analysis using the methylation status of the androgen receptor gene. The mutated X-chromosome was identified by comparison of samples from relatives. Patients underwent genotype categorization and deep clinical phenotyping of symptom severity. Results 43/95 (45\%) women carried mutations categorized as classic. The XCI pattern was skewed (i.e., ≥75:25\% distribution) in 6/87 (7\%) mouth epithelial cell samples, 31/88 (35\%) blood samples, and 9/27 (33\%) skin fibroblast samples. Clinical phenotype, α-galactosidase A (GAL) activity, and lyso-Gb3 levels did not show intergroup differences when stratified for X-chromosomal skewing and activity status of the mutated X-chromosome. Conclusions X-inactivation patterns alone do not reliably reflect the clinical phenotype of women with FD when investigated in biomaterial not directly affected by FD. However, while XCI patterns may vary between tissues, blood frequently shows skewing of XCI patterns.},
  language  = {en}
}
@article{SpitzelWagnerBreyeretal.2022,
  author    = {Spitzel, Marlene and Wagner, Elise and Breyer, Maximilian and Henniger, Dorothea and Bayin, Mehtap and Hofmann, Lukas and Mauceri, Daniela and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Dysregulation of immune response mediators and pain-related ion channels is associated with pain-like behavior in the GLA KO mouse model of Fabry disease},
  series = {Cells},
  volume    = {11},
  journal   = {Cells},
  number    = {11},
  issn      = {2073-4409},
  doi       = {10.3390/cells11111730},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275186},
  year      = {2022},
  abstract  = {Fabry disease (FD) is a rare life-threatening disorder caused by deficiency of the alpha-galactosidase A (GLA) enzyme with a characteristic pain phenotype. Impaired GLA production or function leads to the accumulation of the cell membrane compound globotriaosylceramide (Gb3) in the neurons of the dorsal root ganglia (DRG) of FD patients. Applying immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT PCR) analysis on DRG tissue of the GLA knockout (KO) mouse model of FD, we address the question of how Gb3 accumulation may contribute to FD pain and focus on the immune system and pain-associated ion channel gene expression. We show a higher Gb3 load in the DRG of young (<6 months) (p < 0.01) and old (≥12 months) (p < 0.001) GLA KO mice compared to old wildtype (WT) littermates, and an overall suppressed immune response in the DRG of old GLA KO mice, represented by a reduced number of CD206\(^+\) macrophages (p < 0.01) and lower gene expression levels of the inflammation-associated targets interleukin(IL)1b (p < 0.05), IL10 (p < 0.001), glial fibrillary acidic protein (GFAP) (p < 0.05), and leucine rich alpha-2-glycoprotein 1 (LRG1) (p < 0.01) in the DRG of old GLA KO mice compared to old WT. Dysregulation of immune-related genes may be linked to lower gene expression levels of the pain-associated ion channels calcium-activated potassium channel 3.1 (KCa3.1) and transient receptor potential ankyrin 1 channel (TRPA1). Ion channel expression might further be disturbed by impaired sphingolipid recruitment mediated via the lipid raft marker flotillin-1 (FLOT1). This impairment is represented by an increased number of FLOT1\(^+\) DRG neurons with a membranous expression pattern in old GLA KO mice compared to young GLA KO, young WT, and old WT mice (p < 0.001 each). Further, we provide evidence for aberrant behavior of GLA KO mice, which might be linked to dysregulated ion channel gene expression levels and disturbed FLOT1 distribution patterns. Behavioral testing revealed mechanical hypersensitivity in young (p < 0.01) and old (p < 0.001) GLA KO mice compared to WT, heat hypersensitivity in young GLA KO mice (p < 0.001) compared to WT, age-dependent heat hyposensitivity in old GLA KO mice (p < 0.001) compared to young GLA KO mice, and cold hyposensitivity in young (p < 0.001) and old (p < 0.001) GLA KO mice compared to WT, which well reflects the clinical phenotype observed in FD patients.},
  language  = {en}
}
@article{SommerCarrollKoikeetal.2021,
  author    = {Sommer, Claudia and Carroll, Antonia S. and Koike, Haruki and Katsuno, Masahisa and Ort, Nora and Sobue, Gen and Vucic, Steve and Spies, Judith M. and Doppler, Kathrin and Kiernan, Matthew C.},
  title     = {Nerve biopsy in acquired neuropathies},
  series = {Journal of the Peripheral Nervous System},
  volume    = {26},
  journal   = {Journal of the Peripheral Nervous System},
  number    = {S2},
  doi       = {10.1111/jns.12464},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259555},
  pages     = {S21-S41},
  year      = {2021},
  abstract  = {A diagnosis of neuropathy can typically be determined through clinical assessment and focused investigation. With technological advances, including significant progress in genomics, the role of nerve biopsy has receded over recent years. However, making a specific and, in some cases, tissue-based diagnosis is essential across a wide array of potentially treatable acquired peripheral neuropathies. When laboratory investigations do not suggest a definitive diagnosis, nerve biopsy remains the final step to ascertain the etiology of the disease. The present review highlights the utility of nerve biopsy in confirming a diagnosis, while further illustrating the importance of a tissue-based diagnosis in relation to treatment strategies, particularly when linked to long-term immunosuppressive therapies,},
  language  = {en}
}
@article{SommerKloseWelschetal.2020,
  author    = {Sommer, Claudia and Klose, Petra and Welsch, Patrick and Petzke, Frank and H{\"a}user, Winfried},
  title     = {Opioids for chronic non-cancer neuropathic pain. An updated systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks duration},
  series = {European Journal of Pain},
  volume    = {24},
  journal   = {European Journal of Pain},
  number    = {1},
  doi       = {10.1002/ejp.1494},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218487},
  pages     = {3 -- 18},
  year      = {2020},
  abstract  = {Background and Objective This updated systematic review evaluated the efficacy, tolerability and safety of opioids compared to placebo in chronic non-cancer neuropathic pain. Databases and Data Treatment Clinicaltrials.gov, CENTRAL, PubMed and PsycINFO were searched from October 2013 to June 2019. Randomized controlled trials comparing opioids with placebo and at least 4 weeks double-blinded duration were analysed. Primary outcomes were pain relief of 50\% or greater, disability, tolerability and safety. Effects were summarized by a random effects model using risk differences (RD) or standardized mean differences (SMD). We added four new studies with 662 participants for a total of 16 included studies with 2,199 participants. Study duration ranged between 4 and 12 weeks. Studies with a parallel and cross-over design: Based on low to moderate quality evidence, opioids (buprenorphine, hydromorphone, morphine, oxycodone, tramadol) provided a clinically relevant pain relief of 50\% or greater and reduction of disability compared to placebo. There was no clinically relevant harm with regards to the drop out rate due to adverse and serious adverse events by opioids compared to placebo. Enriched enrolment randomized withdrawal design: Based on low to moderate quality evidence, tapentadol provided a clinically relevant pain relief of 50\% or greater and reduction of disability compared to placebo in diabetic polyneuropathy. There was no clinically relevant harm with regards to the drop out rate due to adverse and serious adverse events by tapentadol compared to placebo. Conclusions Some opioids provided a short-term substantial pain relief in highly selected patients in some neuropathic pain syndromes. Significance Some opioids (buprenorphine, morphine, oxycodone, tramadol, tapentadol) provide substantial pain relief compared to placebo in postherpetic neuralgia and peripheral neuropathies of different aetiologies for 4-12 weeks. There is insufficient evidence to support or refute the suggestion that these drugs are effective in other neuropathic pain conditions. The safety of opioids with regards to abuse and deaths in the studies analysed cannot be extrapolated to routine clinical care.},
  language  = {en}
}
@article{BraunEvdokimovFranketal.2022,
  author    = {Braun, Alexandra and Evdokimov, Dimitar and Frank, Johanna and Pauli, Paul and Wabel, Thomas and {\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia},
  title     = {Relevance of Religiosity for Coping Strategies and Disability in Patients with Fibromyalgia Syndrome},
  series = {Journal of Religion and Health},
  volume    = {61},
  journal   = {Journal of Religion and Health},
  number    = {1},
  issn      = {1573-6571},
  doi       = {10.1007/s10943-020-01177-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269135},
  pages     = {524-539},
  year      = {2022},
  abstract  = {Coping strategies are essential for the outcome of chronic pain. This study evaluated religiosity in a cohort of patients with fibromyalgia syndrome (FMS), its effect on pain and other symptoms, on coping and FMS-related disability. A total of 102 FMS patients were recruited who filled in questionnaires, a subgroup of 42 patients participated in a face-to-face interview, and data were evaluated by correlation and regression analyses. Few patients were traditionally religious, but the majority believed in a higher existence and described their spirituality as "transcendence conviction". The coping strategy "praying-hoping" and the ASP dimension "religious orientation" (r = 0.5, P < 0.05) showed a significant relationship independent of the grade of religiosity (P < 0.05). A high grade of belief in a higher existence was negatively associated with the choice of ignoring as coping strategy (r = - 0.4, P < 0.05). Mood and affect-related variables had the highest impact on disability (b = 0.5, P < 0.05). In this cohort, the grade of religiosity played a role in the choice of coping strategies, but had no effects on health and mood outcome.},
  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}
}