RNA-edited glycine receptors in temporal lobe epilepsy

C-to-U RNA editing has been implicated as possibly either adaptive or maladaptive mechanism in temporal lobe epilepsy (TLE), the most common form of focal epilepsy with a persistently high rate of pharmacoresistance, despite an abundance of available antiepileptic drugs. C-to-U RNA-edited glycine receptors (edGlyR) might present a novel drug target for treatment of pharmacoresistant TLE. Previous studies have shown elevated expression of edGlyR in resected hippocampi of TLE patients, which correlated with the degree of hippocampal sclerosis. C-to-U RNA editing of GlyR mRNA leads to a gain of function, resulting in an increased affinity for glycine. edGlyR act predominantly in presynaptic compartments, where they facilitate neurotransmitter release and, depending on neuron type afflicted with edGlyR expression, induce network hyper- or hypoexcitability. C-to-U RNA editing of GlyR mRNA could therefore contribute to seizure generation or represent an adaptive mechanism to decrease hyperexcitability. The aim of this thesis was to identify specific edGlyR antagonists and investigate their effect on epileptic activity in human brain ex vivo, as well as identify the neuronal cell type expressing edGlyR using a novel RNAediting sensor tool in human brain slice cultures. Using high-throughput screening methods and database research, I was unable to identify a specific edGlyR antagonist. However, one of the molecules tested as a potential edGlyR antagonist, dimethylethanolamine (DMEA), has been tested as treatment option for different neurological disorders, although detailed functional mechanisms are still unknown. Here, I showed that DMEA decreased spontaneous activity in primary neuronal cultures and displayed an antiepileptic effect in patient-derived brain tissue ex vivo. In addition, I established stable viral mediated expression of the RNA-editing sensor tool in human brain slice cultures and showed neuron-specific expression. I propose that application of DMEA as well as identification of RNA-editing on single cell level in human brain tissue present valuable tools for the development of novel therapeutic options in patients with pharmacoresistant TLE.C-zu-U RNA-Editierung wurde sowohl als adaptiver als auch maladaptiver Prozess bei Temporallappenepilepsie (TLE) beschrieben. TLE ist die häufigste Form der fokalen Epilepsie, mit einem hohen Anteil an pharmakoresistenten Verläufen, trotz einer Vielzahl an verfügbaren antiepileptischen Substanzen. Einen neuen potentiell antiepileptischen Mechanismus stellen RNA-editierte Glyzinrezeptoren (edGlyR) dar. Hippocampi von Patienten mit pharmakoresistenter TLE zeigen eine Überexpression von edGlyR mRNA, welche mit der Schwere der Hippocampus-Sklerose korreliert. C-zu-U RNA-Editierung der GlyR mRNA führt zu einem Funktionsgewinn und zu einer erhöhten Affinität für Glyzin. edGlyR wirken überwiegend präsynaptisch, wo sie die Freisetzung von Neurotransmittern erhöhen und bedingt durch die Lokalisation auf inhibitorischen oder exzitatorischen Neuronen zu einer verstärkten oder verminderten neuronalen Erregbarkeit führen. Die C-zu-U RNA-Editierung der GlyR mRNA könnte daher zur Anfallsgenerierung beitragen oder einen adaptiven Mechanismus zur Verringerung der Übererregbarkeit darstellen. Ziel dieser Arbeit war es, spezifische edGlyR-Antagonisten zu identifizieren und ihren Einfluss auf epileptische Aktivität im humanen Gehirn ex vivo zu untersuchen sowie mit Hilfe eines RNA-Editierungssensors das Expressionsmuster von edGlyR auf Einzelzellebene in humanen Hirnschnittkulturen zu identifizieren. Weder mittels high-throughput Screening noch strukturbasierter Datenbankanalyse konnten jedoch in dieser Arbeit spezifische Antagonisten für edGlyR identifiziert werden. Eine der getesteten potentiellen edGlyR Antagonisten, Dimethylethanolamin (DMEA), wurde bereits in diversen präklinischen und klinischen Studien als Therapie für neurologische Erkrankungen getestet, jedoch ohne detailliertes Wissen über den Wirkmechanismus. In dieser Arbeit konnte ich zeigen, dass DMEA die spontane Aktivität von primären neuronalen Kulturen reduziert sowie antiepileptische Effekte in reseziertem humanem Hirngewebe von TLE Patienten aufweist. Zudem konnte ich eine stabile viral-vermittelte Expression des RNA-Editierungssensors spezifisch in Neuronen von humanen Hirnschnittkulturen zeigen. Die Anwendung von DMEA als antiepileptische Substanz sowie die Identifizierung von RNA-Editierung auf Einzelzellenebene stellen essentielle Werkzeuge für die Entwicklung neuartiger antiepileptischer Therapieansätze für Patienten mit pharmakoresistenter TLE dar

Dimethylethanolamine Decreases Epileptiform Activity in Acute Human Hippocampal Slices in vitro

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy with about 30% of patients developing pharmacoresistance. These patients continue to suffer from seizures despite polytherapy with antiepileptic drugs (AEDs) and have an increased risk for premature death, thus requiring further efforts for the development of new antiepileptic therapies. The molecule dimethylethanolamine (DMEA) has been tested as a potential treatment in various neurological diseases, albeit the functional mechanism of action was never fully understood. In this study, we investigated the effects of DMEA on neuronal activity in single-cell recordings of primary neuronal cultures. DMEA decreased the frequency of spontaneous synaptic events in a concentration-dependent manner with no apparent effect on resting membrane potential (RMP) or action potential (AP) threshold. We further tested whether DMEA can exert antiepileptic effects in human brain tissue ex vivo. We analyzed the effect of DMEA on epileptiform activity in the CA1 region of the resected hippocampus of TLE patients in vitro by recording extracellular field potentials in the pyramidal cell layer. Epileptiform burst activity in resected hippocampal tissue from TLE patients remained stable over several hours and was pharmacologically suppressed by lacosamide, demonstrating the applicability of our platform to test antiepileptic efficacy. Similar to lacosamide, DMEA also suppressed epileptiform activity in the majority of samples, albeit with variable interindividual effects. In conclusion, DMEA might present a new approach for treatment in pharmacoresistant TLE and further studies will be required to identify its exact mechanism of action and the involved molecular targets

Is bouldering-psychotherapy a cost-effective way to treat depression when compared to group cognitive behavioral therapy – results from a randomized controlled trial

Background Bouldering-Psychotherapy (BPT) has proven to effectively reduce depressive symptoms, but evidence on its cost-effectiveness is lacking. Corresponding information is paramount to support health policy decision making on a potential implementation of BPT in routine care. Methods Using data from the German KuS trial BPT was compared with group Cognitive Behavioral Therapy (CBT). Severity of depression symptoms at end of the intervention was operationalized via Montgomery-Asberg Depression Rating Scale (MADRS) and Patient Health Questionnaire (PHQ-9). Adopting a societal perspective, direct medical costs and productivity loss were calculated based on standardized unit costs. To determine incremental cost-effectiveness ratios (ICER) and cost-effectiveness-acceptance curves (CEAC), adjusted mean differences (AMD) in costs (gamma-distributed model) and both effect parameters (Gaussian-distributed model) were obtained from 1000 simultaneous bootstrap replications. Results BPT was related to improved effects (AMDs: MADRS -2.58; PHQ-9: − 1.35) at higher costs (AMD: +€ 754). No AMD was significant. ICERs amounted to €288 per MADRS-point and €550 per PHQ-9-point. For both effect parameters about 20% of bootstrap replications indicated dominance of BPT, and about 75% larger effects at higher costs. At hypothetical willingness to pay (WTP) thresholds of €241 (MADRS) and €615 (PHQ-9) per unit of change BPT had a 50% probability of being cost-effective. Conclusion BPT is a promising alternate treatment strategy which – in absence of established WTP thresholds for improving symptoms of depression – cannot unambiguously be claimed cost-effective. Further studies defining subgroups that particularly benefit from BPT appear paramount to delineate recommendations for an efficient prospective roll-out to routine care

Lithium inhibits tryptophan catabolism via the inflammation‐induced kynurenine pathway in human microglia

Despite its decades' long therapeutic use in psychiatry, the biological mechanisms underlying lithium's mood-stabilizing effects have remained largely elusive. Here, we investigated the effect of lithium on tryptophan breakdown via the kynurenine pathway using immortalized human microglia cells, primary human microglia isolated from surgical specimens, and microglia-like cells differentiated from human induced pluripotent stem cells. Interferon (IFN)-gamma, but not lipopolysaccharide, was able to activate immortalized human microglia, inducing a robust increase in indoleamine-2,3-dioxygenase (IDO1) mRNA transcription, IDO1 protein expression, and activity. Further, chromatin immunoprecipitation verified enriched binding of both STAT1 and STAT3 to the IDO1 promoter. Lithium counteracted these effects, increasing inhibitory GSK3 beta(S9) phosphorylation and reducing STAT1(S727) and STAT3(Y705) phosphorylation levels in IFN-gamma treated cells. Studies in primary human microglia and hiPSC-derived microglia confirmed the anti-inflammatory effects of lithium, highlighting that IDO activity is reduced by GSK3 inhibitor SB-216763 and STAT inhibitor nifuroxazide via downregulation of P-STAT1(S727) and P-STAT3(Y705). Primary human microglia differed from immortalized human microglia and hiPSC derived microglia-like cells in their strong sensitivity to LPS, resulting in robust upregulation of IDO1 and anti-inflammatory cytokine IL-10. While lithium again decreased IDO1 activity in primary cells, it further increased release of IL-10 in response to LPS. Taken together, our study demonstrates that lithium inhibits the inflammatory kynurenine pathway in the microglia compartment of the human brain

In vitro and in vivo anti-epileptic efficacy of eslicarbazepine acetate in a mouse model of KCNQ2-related self-limited epilepsy

Background and purpose: The KCNQ2 gene encodes for the Kv 7.2 subunit of non-inactivating potassium channels. KCNQ2-related diseases range from autosomal dominant neonatal self-limited epilepsy, often caused by KCNQ2 haploinsufficiency, to severe encephalopathies caused by KCNQ2 missense variants. In vivo and in vitro effects of the sodium channel blocker eslicarbazepine acetate (ESL) and eslicarbazepine metabolite (S-Lic) in a mouse model of self-limited neonatal epilepsy as a first attempt to assess the utility of ESL in the KCNQ2 disease spectrum was investigated. Experimental approach: Effects of S-Lic on in vitro physiological and pathological hippocampal neuronal activity in slices from mice carrying a heterozygous deletion of Kcnq2 (Kcnq2+/- ) and Kcnq2+/+ mice were investigated. ESL in vivo efficacy was investigated in the 6-Hz psychomotor seizure model in both Kcnq2+/- and Kcnq2+/+ mice. Key results: S-Lic increased the amplitude and decreased the incidence of physiological sharp wave-ripples in a concentration-dependent manner and slightly decreased gamma oscillations frequency. 4-Aminopyridine-evoked seizure-like events were blocked at high S-Lic concentrations and substantially reduced in incidence at lower concentrations. These results were not different in Kcnq2+/+ and Kcnq2+/- mice, although the EC50 estimation implicated higher efficacy in Kcnq2+/- animals. In vivo, Kcnq2+/- mice had a lower seizure threshold than Kcnq2+/+ mice. In both genotypes, ESL dose-dependently displayed protection against seizures. Conclusions and implications: S-Lic slightly modulates hippocampal oscillations and blocks epileptic activity in vitro and in vivo. Our results suggest that the increased excitability in Kcnq2+/- mice is effectively targeted by S-Lic high concentrations, presumably by blocking diverse sodium channel subtypes

Rapid identification of sepsis in the emergency department.

OBJECTIVES: Recent research has helped define the complex pathways in sepsis, affording new opportunities for advancing diagnostics tests. Given significant advances in the field, a group of academic investigators from emergency medicine, intensive care, pathology, and pharmacology assembled to develop consensus around key gaps and potential future use for emerging rapid host response diagnostics assays in the emergency department (ED) setting. METHODS: A modified Delphi study was conducted that included 26 panelists (expert consensus panel) from multiple specialties. A smaller steering committee first defined a list of Delphi statements related to the need for and future potential use of a hypothetical sepsis diagnostic test in the ED. Likert scoring was used to assess panelists agreement or disagreement with statements. Two successive rounds of surveys were conducted and consensus for statements was operationally defined as achieving agreement or disagreement of 75% or greater. RESULTS: Significant gaps were identified related to current tools for assessing risk of sepsis in the ED. Strong consensus indicated the need for a test providing an indication of the severity of dysregulated host immune response, which would be helpful even if it did not identify the specific pathogen. Although there was a relatively high degree of uncertainty regarding which patients would most benefit from the test, the panel agreed that an ideal host response sepsis test should aim to be integrated into ED triage and thus should produce results in less than 30 minutes. The panel also agreed that such a test would be most valuable for improving sepsis outcomes and reducing rates of unnecessary antibiotic use. CONCLUSION: The expert consensus panel expressed strong consensus regarding gaps in sepsis diagnostics in the ED and the potential for new rapid host response tests to help fill these gaps. These finding provide a baseline framework for assessing key attributes of evolving host response diagnostic tests for sepsis in the ED

Epidemiological Record of Permanent Artificial Cardiac Pacemaker Implant at a Reference Center

Objective: To identify the profile of patients who implanted pacemakers and their complications in a tertiary cardiology center in the state of Santa Catarina. Methods: Unicentric, observational and prospective study with 81 patients submitted to pacemaker implantation by the Cardiovascular Surgery Service. Results: Provisional pacemaker was necessary in 42 cases (51.8%) and the average time of temporary pacemaker insertion was 2.2 days. Death occurred in 3 patients (3.7%), however only 1 case (1.2%) was associated with the implant. Conclusion: The clinical characteristics and indications of the implant in the study population were similar to those found in the literature, however the number of complications was high and the length of stay of the provisional pacemaker is beyond that recommended

Epidemiological Record of Permanent Artificial Cardiac Pacemaker Implant at a Reference Center

Objective: To identify the profile of patients who implanted pacemakers and their complications in a tertiary cardiology center in the state of Santa Catarina. Methods: Unicentric, observational and prospective study with 81 patients submitted to pacemaker implantation by the Cardiovascular Surgery Service. Results: Provisional pacemaker was necessary in 42 cases (51.8%) and the average time of temporary pacemaker insertion was 2.2 days. Death occurred in 3 patients (3.7%), however only 1 case (1.2%) was associated with the implant. Conclusion: The clinical characteristics and indications of the implant in the study population were similar to those found in the literature, however the number of complications was high and the length of stay of the provisional pacemaker is beyond that recommended