TY - JOUR A1 - Breyer, Maximilian A1 - Grüner, Julia A1 - Klein, Alexandra A1 - Finke, Laura A1 - Klug, Katharina A1 - Sauer, Markus A1 - Üçeyler, Nurcan T1 - \(In\) \(vitro\) characterization of cells derived from a patient with the GLA variant c.376A>G (p.S126G) highlights a non-pathogenic role in Fabry disease JF - Molecular Genetics and Metabolism Reports N2 - 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. KW - Fabry disease KW - variants of unknown significance KW - C.376A>G (p.S126G) KW - globotriaosylceramide KW - induced pluripotent stem cells KW - sensory neurons KW - disease model KW - α-Galactosidase A Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350295 SN - 22144269 VL - 38 ER - TY - JOUR A1 - Kollert, Sina A1 - Dombert, Benjamin A1 - Döring, Frank A1 - Wischmeyer, Erhard T1 - Activation of TRESK channels by the inflammatory mediator lysophosphatidic acid balances nociceptive signalling JF - Scientific Reports N2 - In dorsal root ganglia (DRG) neurons TRESK channels constitute a major current component of the standing outward current IK\(_{SO}\). A prominent physiological role of TRESK has been attributed to pain sensation. During inflammation mediators of pain e.g. lysophosphatidic acid (LPA) are released and modulate nociception. We demonstrate co-expression of TRESK and LPA receptors in DRG neurons. Heterologous expression of TRESK and LPA receptors in Xenopus oocytes revealed augmentation of basal K\(^{+}\) currents upon LPA application. In DRG neurons nociception can result from TRPV\(_{1}\) activation by capsaicin or LPA. Upon co-expression in Xenopus oocytes LPA simultaneously increased both depolarising TRPV\(_{1}\) and hyperpolarising TRESK currents. Patch-clamp recordings in cultured DRG neurons from TRESK[wt] mice displayed increased IK\(_{SO}\) after application of LPA whereas under these conditions IK\(_{SO}\) in neurons from TRESK[ko] mice remained unaltered. Under current-clamp conditions LPA application differentially modulated excitability in these genotypes upon depolarising pulses. Spike frequency was attenuated in TRESK[wt] neurons and, in contrast, augmented in TRESK[ko] neurons. Accordingly, excitation of nociceptive neurons by LPA is balanced by co-activation of TRESK channels. Hence excitation of sensory neurons is strongly controlled by the activity of TRESK channels, which therefore are good candidates for the treatment of pain disorders. KW - protein coupled receptors KW - molecular mechanisms KW - neuropathic pain KW - migraine KW - initiation KW - modulation KW - cells KW - sensory neurons KW - domain K\(^{+}\) channels KW - 2-pore potassium channel Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148312 VL - 5 IS - 12548 ER - TY - JOUR A1 - Reinhold, A. K. A1 - Batti, L. A1 - Bilbao, D. A1 - Buness, A. A1 - Rittner, H. L. A1 - Heppenstall, P. A. T1 - Differential Transcriptional Profiling of Damaged and Intact Adjacent Dorsal Root Ganglia Neurons in Neuropathic Pain JF - PLoS ONE N2 - Neuropathic pain, caused by a lesion in the somatosensory system, is a severely impairing mostly chronic disease. While its underlying molecular mechanisms are not thoroughly understood, neuroimmune interactions as well as changes in the pain pathway such as sensitization of nociceptors have been implicated. It has been shown that not only are different cell types involved in generation and maintenance of neuropathic pain, like neurons, immune and glial cells, but, also, intact adjacent neurons are relevant to the process. Here, we describe an experimental approach to discriminate damaged from intact adjacent neurons in the same dorsal root ganglion (DRG) using differential fluorescent neuronal labelling and fluorescence-activated cell sorting (FACS). Two fluorescent tracers, Fluoroemerald (FE) and 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI), were used, whose properties allow us to distinguish between damaged and intact neurons. Subsequent sorting permitted transcriptional analysis of both groups. Results and qPCR validation show a strong regulation in damaged neurons versus contralateral controls as well as a moderate regulation in adjacent neurons. Data for damaged neurons reveal an mRNA expression pattern consistent with established upregulated genes like galanin, which supports our approach. Moreover, novel genes were found strongly regulated such as corticotropinreleasing hormone (CRH), providing novel targets for further research. Differential fluorescent neuronal labelling and sorting allows for a clear distinction between primarily damaged neuropathic neurons and "bystanders," thereby facilitating a more detailed understanding of their respective roles in neuropathic processes in the DRG. KW - peripheral nerve injury KW - sensory neurons KW - rat KW - involvement KW - mechanisms KW - receptors KW - inhibition KW - expression KW - sciatic nerve KW - inflammatory pain Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143290 VL - 10 IS - 4 ER -