@article{LauUeceylerCairnsetal.2022,
  author    = {Lau, Kolja and {\"U}{\c{c}}eyler, Nurcan and Cairns, Tereza and Lorenz, Lora and Sommer, Claudia and Schindeh{\"u}tte, Magnus and Amann, Kerstin and Wanner, Christoph and Nordbeck, Peter},
  title     = {Gene variants of unknown significance in Fabry disease: Clinical characteristics of c.376AG (p.Ser126Gly)},
  series = {Molecular Genetics \& Genomic Medicine},
  volume    = {10},
  journal   = {Molecular Genetics \& Genomic Medicine},
  number    = {5},
  doi       = {10.1002/mgg3.1912},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312817},
  year      = {2022},
  abstract  = {Background Anderson-Fabry disease (FD) is an X-linked lysosomal storage disorder with varying organ involvement and symptoms, depending on the underlying mutation in the alpha-galactosidase A gene (HGNC: GLA). With genetic testing becoming more readily available, it is crucial to precisely evaluate pathogenicity of each genetic variant, in order to determine whether there is or might be not a need for FD-specific therapy in affected patients and relatives at the time point of presentation or in the future. Methods This case series investigates the clinical impact of the specific GLA gene variant c.376A>G (p.Ser126Gly) in five (one heterozygous and one homozygous female, three males) individuals from different families, who visited our center between 2009 and 2021. Comprehensive neurological, nephrological and cardiac examinations were performed in all cases. One patient received a follow-up examination after 12 years. Results Index events leading to suspicion of FD were mainly unspecific neurological symptoms. However, FD-specific biomarkers, imaging examinations (i.e., brain MRI, heart MRI), and tissue-specific diagnostics, including kidney and skin biopsies, did not reveal evidence for FD-specific symptoms or organ involvement but showed normal results in all cases. This includes findings from 12-year follow-up in one patient with renal biopsy. Conclusion These findings suggest that p.Ser126Gly represents a benign GLA gene variant which per se does not cause FD. Precise clinical evaluation in individuals diagnosed with genetic variations of unknown significance should be performed to distinguish common symptoms broadly prevalent in the general population from those secondary to FD.},
  language  = {en}
}
@article{ErbacherVaknineMoshitzkyetal.2022,
  author    = {Erbacher, Christoph and Vaknine, Shani and Moshitzky, Gilli and Lobentanzer, Sebastian and Eisenberg, Lina and Evdokimov, Dimitar and Sommer, Claudia and Greenberg, David S. and Soreq, Hermona and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Distinct CholinomiR blood cell signature as a potential modulator of the cholinergic system in women with fibromyalgia syndrome},
  series = {Cells},
  volume    = {11},
  journal   = {Cells},
  number    = {8},
  issn      = {2073-4409},
  doi       = {10.3390/cells11081276},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270686},
  year      = {2022},
  abstract  = {Fibromyalgia syndrome (FMS) is a heterogeneous chronic pain syndrome characterized by musculoskeletal pain and other key co-morbidities including fatigue and a depressed mood. FMS involves altered functioning of the central and peripheral nervous system (CNS, PNS) and immune system, but the specific molecular pathophysiology remains unclear. Anti-cholinergic treatment is effective in FMS patient subgroups, and cholinergic signaling is a strong modulator of CNS and PNS immune processes. Therefore, we used whole blood small RNA-sequencing of female FMS patients and healthy controls to profile microRNA regulators of cholinergic transcripts (CholinomiRs). We compared microRNA profiles with those from Parkinson's disease (PD) patients with pain as disease controls. We validated the sequencing results with quantitative real-time PCR (qRT-PCR) and identified cholinergic targets. Further, we measured serum cholinesterase activity in FMS patients and healthy controls. Small RNA-sequencing revealed FMS-specific changes in 19 CholinomiRs compared to healthy controls and PD patients. qRT-PCR validated miR-182-5p upregulation, distinguishing FMS patients from healthy controls. mRNA targets of CholinomiRs bone morphogenic protein receptor 2 and interleukin 6 signal transducer were downregulated. Serum acetylcholinesterase levels and cholinesterase activity in FMS patients were unchanged. Our findings identified an FMS-specific CholinomiR signature in whole blood, modulating immune-related gene expression.},
  language  = {en}
}
@article{KressEgenolfSommeretal.2023,
  author    = {Kreß, Luisa and Egenolf, Nadine and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Cytokine expression profiles in white blood cells of patients with small fiber neuropathy},
  series = {BMC Neuroscience},
  volume    = {24},
  journal   = {BMC Neuroscience},
  number    = {1},
  doi       = {10.1186/s12868-022-00770-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300619},
  year      = {2023},
  abstract  = {Background The role of cytokines in the pathophysiology, diagnosis, and prognosis of small fiber neuropathy (SFN) is incompletely understood. We studied expression profiles of selected pro- and anti-inflammatory cytokines in RNA from white blood cells (WBC) of patients with a medical history and a clinical phenotype suggestive for SFN and compared data with healthy controls. Methods We prospectively recruited 52 patients and 21 age- and sex-matched healthy controls. Study participants were characterized in detail and underwent complete neurological examination. Venous blood was drawn for routine and extended laboratory tests, and for WBC isolation. Systemic RNA expression profiles of the pro-inflammatory cytokines interleukin (IL)-1ß, IL-2, IL-8, tumor necrosis factor-alpha (TNF) and the anti-inflammatory cytokines IL-4, IL-10, transforming growth factor beta-1 (TGF) were analyzed. Protein levels of IL-2, IL-8, and TNF were measured in serum of patients and controls. Receiver operating characteristic (ROC)-curve analysis was used to determine the accuracy of IL-2, IL-8, and TNF in differentiating patients and controls. To compare the potential discriminatory efficacy of single versus combined cytokines, equality of different AUCs was tested. Results WBC gene expression of IL-2, IL-8, and TNF was higher in patients compared to healthy controls (IL-2: p = 0.02; IL-8: p = 0.009; TNF: p = 0.03) and discriminated between the groups (area under the curve (AUC) ≥ 0.68 for each cytokine) with highest diagnostic accuracy reached by combining the three cytokines (AUC = 0.81, sensitivity = 70\%, specificity = 86\%). Subgroup analysis revealed the following differences: IL-8 and TNF gene expression levels were higher in female patients compared to female controls (IL-8: p = 0.01; TNF: p = 0.03). The combination of TNF with IL-2 and TNF with IL-2 and IL-8 discriminated best between the study groups. IL-2 was higher expressed in patients with moderate pain compared to those with severe pain (p = 0.02). Patients with acral pain showed higher IL-10 gene expression compared to patients with generalized pain (p = 0.004). We further found a negative correlation between the relative gene expression of IL-2 and current pain intensity (p = 0.02). Serum protein levels of IL-2, IL-8, and TNF did not differ between patients and controls. Conclusions We identified higher systemic gene expression of IL-2, IL-8, and TNF in SFN patients than in controls, which may be of potential relevance for diagnostics and patient stratification.},
  language  = {en}
}
@article{GarciaFernandezReinholdUeceyleretal.2023,
  author    = {Garc{\´i}a-Fern{\´a}ndez, Patricia and Reinhold, Colette and {\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia},
  title     = {Local inflammatory mediators involved in neuropathic pain},
  series = {International Journal of Molecular Sciences},
  volume    = {24},
  journal   = {International Journal of Molecular Sciences},
  number    = {9},
  issn      = {1422-0067},
  doi       = {10.3390/ijms24097814},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313613},
  year      = {2023},
  abstract  = {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.},
  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{BreyerGruenerKleinetal.2024,
  author    = {Breyer, Maximilian and Gr{\"u}ner, Julia and Klein, Alexandra and Finke, Laura and Klug, Katharina and Sauer, Markus and {\"U}{\c{c}}eyler, Nurcan},
  title     = {\(In\) \(vitro\) characterization of cells derived from a patient with the GLA variant c.376A>G (p.S126G) highlights a non-pathogenic role in Fabry disease},
  series = {Molecular Genetics and Metabolism Reports},
  volume    = {38},
  journal   = {Molecular Genetics and Metabolism Reports},
  issn      = {22144269},
  doi       = {10.1016/j.ymgmr.2023.101029},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350295},
  year      = {2024},
  abstract  = {Highlights • The GLA variant S126G is not associated with Fabry symptoms in the presented case • S126G has no effect on α-GAL A activity or Gb3 levels in this patient • S126G sensory neurons show no electrophysiological abnormalities Abstract Fabry disease (FD) is a life-limiting disorder characterized by intracellular globotriaosylceramide (Gb3) accumulations. The underlying α-galactosidase A (α-GAL A) deficiency is caused by variants in the gene GLA. Variants of unknown significance (VUS) are frequently found in GLA and challenge clinical management. Here, we investigated a 49-year old man with cryptogenic lacunar cerebral stroke and the chance finding of the VUS S126G, who was sent to our center for diagnosis and initiation of a costly and life-long FD-specific treatment. We combined clinical examination with in vitro investigations of dermal fibroblasts (HDF), induced pluripotent stem cells (iPSC), and iPSC-derived sensory neurons. We analyzed α-GAL A activity in iPSC, Gb3 accumulation in all three cell types, and action potential firing in sensory neurons. Neurological examination and small nerve fiber assessment was normal except for reduced distal skin innervation. S126G iPSC showed normal α-GAL A activity compared to controls and no Gb3 deposits were found in all three cell types. Baseline electrophysiological characteristics of S126G neurons showed no difference compared to healthy controls as investigated by patch-clamp recordings. We pioneer multi-level cellular characterization of the VUS S126G using three cell types derived from a patient and provide further evidence for the benign nature of S126G in GLA, which is of great importance in the management of such cases in clinical practice.},
  language  = {en}
}
@article{JaenschEvdokimovEgenolfetal.2024,
  author    = {J{\"a}nsch, Sarah and Evdokimov, Dimitar and Egenolf, Nadine and Meyer zu Altenschildesche, Caren and Kreß, Luisa and {\"U}{\c{c}}eyler, Nurcan},
  title     = {Distinguishing fibromyalgia syndrome from small fiber neuropathy: a clinical guide},
  series = {Pain Reports},
  volume    = {9},
  journal   = {Pain Reports},
  number    = {1},
  doi       = {10.1097/PR9.0000000000001136},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350306},
  year      = {2024},
  abstract  = {Introduction: Fibromyalgia syndrome (FMS) and small fiber neuropathy (SFN) are distinct pain conditions that share commonalities and may be challenging as for differential diagnosis. Objective: To comprehensively investigate clinical characteristics of women with FMS and SFN to determine clinically applicable parameters for differentiation. Methods: We retrospectively analyzed medical records of 158 women with FMS and 53 with SFN focusing on pain-specific medical and family history, accompanying symptoms, additional diseases, and treatment. We investigated data obtained using standardized pain, depression, and anxiety questionnaires. We further analyzed test results and findings obtained in standardized small fiber tests. Results: FMS patients were on average ten years younger at symptom onset, described higher pain intensities requiring frequent change of pharmaceutics, and reported generalized pain compared to SFN. Pain in FMS was accompanied by irritable bowel or sleep disturbances, and in SFN by paresthesias, numbness, and impaired glucose metabolism (P < 0.01 each). Family history was informative for chronic pain and affective disorders in FMS (P < 0.001) and for neurological disorders in SFN patients (P < 0.001). Small fiber pathology in terms of skin denervation and/or thermal sensory threshold elevation was present in 110/158 (69.7 \%) FMS patients and 39/53 (73.6 \%) SFN patients. FMS patients mainly showed proximally reduced skin innervation and higher corneal nerve branch densities (p<0.001) whereas SFN patients were characterized by reduced cold detection and prolonged electrical A-delta conduction latencies (P < 0.05). Conclusions: Our data show that FMS and SFN differ substantially. Detailed pain, drug and family history, investigating blood glucose metabolism, and applying differential small fiber tests may help to improve diagnostic differentiation and targeted therapy.},
  language  = {en}
}