Einfluss von Trefoilfaktor 3 auf Gliazellen

Trefoil peptide 3 (TFF3) reduces the expression of pro-inflammatory mediators in cultivated microglia Ann-Kristin Helmers, Jessica Spreu, Ralph Lucius, Uta Rickert Institutes of Anatomy Christian-Albrechts-University of Kiel Introduction: Trefoil factor 3 (TFF3) is a member of the trefoil peptide family characterized by a highly conserved motif containing 38-39 amino acids with 6 cysteine residues. Previous studies suggest an important role of the trefoil peptide family members in regeneration and the modulation of immune response of the gut (Hoffmann, 2009). Furthermore members support catabolic functions in diseased articular cartilage, activates matrix metalloproteinases and enhances apoptosis of articular cartilage chondrocytes (Rosler et al., 2010). TFF members have also been detected in the central nervous system by immunohistochemistry, especially in the cerebellum, the temporal cortex and the hippocampus (Hoffmann, 2009). In this study, we especially examied the function of TFF3 in cells of the central nervous system. Methods: Using RT-PCR and immunohistochemistry we investigated whether primary astrocytes or microglia express TFF3 and explored a possible regulation of TFF3-mRNA synthesis in inflamed microglia cells and astrocytes via quantitative PCR. To induce inflammation we utilized an in-vitro model of brain inflammation using lipopolysaccharide (LPS). Furthermore, we showed the influence of TFF3 on inflamed microglia. Therefore we measured the activation of microglia via quantification of mRNA synthesis of inducible NO synthase (iNOS) and cyclooxygenase 2 (Cox-2) and pro-inflammatory cytokines as interleukin-1β (Il-1β) and Interleuki-6 (Il-6) and tumornecrosisfactor-α (TNF-α). In addition we explored the influence of TFF3 on the quantitative Il-6 and TNF-α protein synthesis in inflamed microglia via ELISA. Finally, we investigated the intracellular signaling mechanisms triggered by TFF3 in inflamed microglia using Western blotting and immunocytochemistry. Results: RT-PCR and immunohistochemistry revealed expression and regulation by LPS of TFF3 in astrocytes, but expression in microglia was missing. Quantification of mRNA synthesis of iNOS, Cox-2 and pro-inflammatory cytokines such as Il-1β, Il-6 and TNF-α showed an inhibitory effect of TFF3 on inflamed microglia. Additionally, ELISA data demonstrated inhibition of protein synthesis of Il-6 and TNF-α. Signal transduction analysis data suggest a participation of NF-κB-signaling and a MAP-kinase pathway. Conclusion: Our results indicate that (i) cultivated astrocytes produce TFF3, which is able to (ii) decrease pro inflammatory mediators and cytokines of activated microglia cells. A major unanswered question is wether pharmacological inhibition of neuroinflammation, e.g. via TFF3, will be able to slow neurodegenerative diseases. Key words: TFF3, microglia, astrocytes, cytokines, inflammation, neuroprotectio

Investigation of Magnetoelectric Sensor Requirements for Deep Brain Stimulation Electrode Localization and Rotational Orientation Detection

Correct position and orientation of a directional deep brain stimulation (DBS) electrode in the patient's brain must be known to fully exploit its benefit in guiding stimulation programming. Magnetoelectric (ME) sensors can play a critical role here. The aim of this study was to determine the minimum required limit of detection (LOD) of a ME sensor that can be used for this application by measuring the magnetic field induced by DBS. For this experiment, a commercial DBS system was integrated into a head phantom and placed inside of a state-of-the-art Superconducting Quantum Interference Device (SQUID)-based magnetoencephalography system. Measurements were performed and analyzed with digital signal processing. Investigations have shown that the minimum required detection limit depends on various factors such as: measurement distance to electrode, bandwidth of magnetic sensor, stimulation amplitude, stimulation pulse width, and measurement duration. For a sensor that detects only a single DBS frequency (stimulation frequency or its harmonics), a LOD of at least 0.04 pT/Hz0.5 is required for 3 mA stimulation amplitude and 60 μμs pulse width. This LOD value increases by an order of magnitude to 0.4 pT/Hz0.5 for a 1 kHz, and by approximately two orders to 3 pT/Hz0.5 for a 10 kHz sensor bandwidth. By averaging, the LOD can be reduced by at least another 2 orders of magnitude with a measurement duration of a few minutes

Riscurile și beneficiile înregistrării cu microelectrod în chirurgia bolii Parkinson

Background. Microelectrode recording is believed to improve the outcome by enhancing the precision of electrodes used in deep brain stimulation in patients with Parkinson’s Disease. There is a trend that higher number of penetrations correlate with high rate of hemorrhagic complications. Objective of the study. Determine the clinical outcome of patients stimulated decentrally compared to those placed centrally. Additionally, to assess whether a higher number of penetrations correlate with higher rates of intracranial bleeding. Material and Methods. This monocentric study included 556 patients with bilateral STN-DBS and relies on a large prospectively established database. Data were available from 400 patients. The outcome parameter was the stimulation-induced improvement of the UPDRS for PD. We compared patients with both electrodes centrally to that bi-decentrally. Also, we determined the rate of surgical complications. Results. A decentral tract was chosen in 41% of the electrodes based on clinical grounds (central, n = 471 electrodes; decentral, n = 329). Motor symptom improvement was not different between patients with electrodes implanted bilaterally in the central (44.39% ± 22.71) or decentral (43,22% ± 17) trajectory bilaterally (p = 0.5571). Similar results were obtained for the hemibody score and subscores for akinesia, tremor, rigidity, postural instability and gait disorder. The overall bleeding rate was 2,78% and not depending on the number of penetrations. Conclusion. Outcomes between the groups with central or decentral electrode trajectories did not differ and, therefore, the use of mMER is likely to improve outcome quality. Comparison with other cohorts does not disclose a higher rate of bleeding complications in this cohort with mMER. Introducere. În chirurgia bolii Parkinson, înregistrarea cu microelectrod se utilizează pentru determinarea punctului optim pentru stimulare cerebrală profundă. Se consideră că numărul crescut de penetrații corelează cu rata mai mare a complicațiilor hemoragice postoperatorii. Scopul lucrării. De a determina efectul clinic al pacienților stimulați cu electrozi bicentral versus cei implantați decentral bilateral. De asemenea, de a evalua dacă numărul mai mare de penetrații corelează cu rata mai mare a sângerării intracraniene. Material și Metode. Acest studiu monocentric a inclus 556 de pacienți cu boala Parkinson, stimulați bilateral, bază pe o bază de date prospectivă. Datele complete au fost găsite la 400 de pacienți. Parametrul pentru comparație a fost scala UPDRS pentru BP. Studiul nostru a comparat pacienții cu ambii electrozi implantați bilateral central și decentral. De asemenea, s-a studiat rata sângerării postoperatorii. Rezultate. Traiectorie decentrală s-a ales în 41% din electrozi pe baza la rezultatul clinic (central - 471 electrozi, decentral - 329). Ameliorarea simptomelor motorii nu diferă între grupurile de pacienți cu electrozi implantați bilateral central (44.39% ± 22.71) sau decentral (43, 22% ± 17), p = 0.56. Aceleași rezultate s-au obținut pentru scorul hemibody și subscoruri ca: akinezia, tremorul, rigiditatea, tulburările de statică și mers. Incidența hemoragiei a fost de 2.78% și nu corelează cu numărul de penetrații cu microelectroade. Concluzii. Rezultatul clinic al pacienților cu ambii electrozi bilateral central și decentral nu diferă. Astfel, utilizarea MER poate ameliora rezultatul final. Totodată, incidența complicațiilor postoperatorii hemoragice în studiul nostru nu este mai mare decât în alte studii

The role of microelectrode recording during Deep Brain Stimulation of Subthalamic Nucleus in patients with Parkinson’s disease

Background: Deep brain stimulation of the subthalamic nucleus improves symptoms of Parkinson’s disease. However, the clinical outcome depends on the accurate location of the final electrode. Multiple microelectrode recording is believed to improve the precision, although it prolongs the duration of surgery. We hypothesize that patients implanted in the central trajectory have the same outcome as patients implanted decentrally. Material and methods: This study was carried out in UKSH Kiel and included 556 patients treated from 1999 until 2018 with bilateral STN-DBS (safety population). Pre- and postoperative efficacy data were available from 400 patients. The outcome parameter was the stimulation-induced improvement of the UPDRS for PD. We compared patients with both electrodes centrally to that bi-decentrally. The rate of surgical complications was determined with postoperative imaging. Results: A decentral tract was chosen in 41% of the electrodes (central, n = 471 electrodes; decentral, n = 329). Motor improvement was not different between patients with electrodes implanted bicentral (44.39% ± 22.71) or decentral (43.22% ± 17) trajectory bilaterally (p = 0.5571). Similar results were obtained for the hemi body score and subscores for akinesia, tremor, rigidity, postural instability and gait disorder. The overall bleeding rate was 2.78% and not dependent on the number of penetrations. Conclusions: Outcomes between the groups did not differ and, therefore, the use of mMER is likely to improve the outcome. Comparison with other cohorts does not disclose a higher rate of bleeding complications in this cohort with mMER

Influence of Simulated Deep Brain Stimulation on the Expression of Inflammatory Mediators by Human Central Nervous System Cells In Vitro

Deep brain stimulation (DBS) seems to modulate inflammatory processes. Whether this modulation leads to an induction or suppression of inflammatory mediators is still controversially discussed. Most studies of the influence of electrical stimulation on inflammation were conducted in rodent models with direct current stimulation and/or long impulses, both of which differ from the pattern in DBS. This makes comparisons with the clinical condition difficult. We established an in-vitro model that simulated clinical stimulation patterns to investigate the influence of electrical stimulation on proliferation and survival of human astroglial cells, microglia, and differentiated neurons. We also examined its influence on the expression of the inflammatory mediators C-X-C motif chemokine (CXCL)12, CXCL16, CC-chemokin-ligand-2 (CCL)2, CCL20, and interleukin (IL)-1β and IL-6 by these cells using quantitative polymerase chain reaction. In addition, protein expression was assessed by immunofluorescence double staining. In our model, electrical stimulation did not affect proliferation or survival of the examined cell lines. There was a significant upregulation of CXCL12 in the astrocyte cell line SVGA, and of IL-1β in differentiated SH-SY5Y neuronal cells at both messenger RNA and protein levels. Our model allowed a valid examination of chemokines and cytokines associated with inflammation in human brain cells. With it, we detected the induction of inflammatory mediators by electrical stimulation in astrocytes and neurons

MaDoPO: Magnetic Detection of Positions and Orientations of Segmented Deep Brain Stimulation Electrodes: A Radiation-Free Method Based on Magnetoencephalography

Background: Current approaches to detect the positions and orientations of directional deep brain stimulation (DBS) electrodes rely on radiative imaging data. In this study, we aim to present an improved version of a radiation-free method for magnetic detection of the position and the orientation (MaDoPO) of directional electrodes based on a series of magnetoencephalography (MEG) measurements and a possible future solution for optimized results using emerging on-scalp MEG systems. Methods: A directional DBS system was positioned into a realistic head–torso phantom and placed in the MEG scanner. A total of 24 measurements of 180 s each were performed with different predefined electrode configurations. Finite element modeling and model fitting were used to determine the position and orientation of the electrode in the phantom. Related measurements were fitted simultaneously, constraining solutions to the a priori known geometry of the electrode. Results were compared with the results of the high-quality CT imaging of the phantom. Results: The accuracy in electrode localization and orientation detection depended on the number of combined measurements. The localization error was minimized to 2.02 mm by considering six measurements with different non-directional bipolar electrode configurations. Another six measurements with directional bipolar stimulations minimized the orientation error to 4°. These values are mainly limited due to the spatial resolution of the MEG. Moreover, accuracies were investigated as a function of measurement time, number of sensors, and measurement direction of the sensors in order to define an optimized MEG device for this application. Conclusion: Although MEG introduces inaccuracies in the detection of the position and orientation of the electrode, these can be accepted when evaluating the benefits of a radiation-free method. Inaccuracies can be further reduced by the use of on-scalp MEG sensor arrays, which may find their way into clinics in the foreseeable future

Expression of interleukin-18 in muscle tissue of patients with polymyositis or dermatomyositis and effects of conventional immunosuppressive treatment

Objectives: To investigate the expression of IL-18 in symptomatic and asymptomatic muscle tissues of patients with PM and DM and the effects of conventional immunosuppressive treatment on such expression. Methods: Two cohorts of patients were included in this study. The first cohort consisted of 10 new-onset myositis patients. IL-18 expression was compared between symptomatic and asymptomatic muscle biopsies that were taken prior to treatment. The second cohort consisted of another 10 patients with repeated muscle biopsies before and after 8 months with conventional immunosuppressive treatment. Using immunohistochemistry, IL-18 expression in muscle tissues was compared before and after treatment. Biopsies from seven healthy individuals were included as controls. Results: IL-18 expression was predominantly localized to inflammatory cells and capillaries in patients and mostly to capillaries in healthy controls. Total IL-18 expression in muscle tissues from the new-onset patients, at both symptomatic and asymptomatic sites, was significantly higher compared with healthy controls (P = 0.007 and P = 0.002) with no statistical difference in appearances between symptomatic and asymptomatic sites. The number of IL-18 positive capillaries was not different among symptomatic, asymptomatic and healthy muscles. Total IL-18 expression appeared lower in biopsies from patients receiving and improving with immunosuppressive treatment, particularly the number of IL-18 positive inflammatory cells but not the number of IL-18 positive capillaries, which was consistent with significantly decreased expression of CD68+ macrophages (P = 0.04). Conclusion: IL-18 is highly expressed in muscle tissue in the context of inflammatory myopathies and based on its plausible effector functions could provide a novel therapeutic target in future

A multicenter, open-label, controlled trial on acceptance, convenience, and complications of rechargeable internal pulse generators for deep brain stimulation: the Multi Recharge Trial

OBJECTIVE Rechargeable neurostimulators for deep brain stimulation have been available since 2008, promising longer battery life and fewer replacement surgeries compared to non-rechargeable systems. Long-term data on how recharging affects movement disorder patients are sparse. This is the first multicenter, patient-focused, industry-independent study on rechargeable neurostimulators. METHODS Four neurosurgical centers sent a questionnaire to all adult movement disorder patients with a rechargeable neurostimulator implanted at the time of the trial. The primary endpoint was the convenience of the recharging process rated on an ordinal scale from "very hard" (1) to "very easy" (5). Secondary endpoints were charge burden (time spent per week on recharging), user confidence, and complication rates. Endpoints were compared for several subgroups. RESULTS Datasets of 195 movement disorder patients (66.1% of sent questionnaires) with Parkinson's disease (PD), tremor, or dystonia were returned and included in the analysis. Patients had a mean age of 61.3 years and the device was implanted for a mean of 40.3 months. The overall convenience of recharging was rated as "easy" (4). The mean charge burden was 122 min/wk and showed a positive correlation with duration of therapy; 93.8% of users felt confident recharging the device. The rate of surgical revisions was 4.1%, and the infection rate was 2.1%. Failed recharges occurred in 8.7% of patients, and 3.6% of patients experienced an interruption of therapy because of a failed recharge. Convenience ratings by PD patients were significantly worse than ratings by dystonia patients. Caregivers recharged the device for the patient in 12.3% of cases. Patients who switched from a non-rechargeable to a rechargeable neurostimulator found recharging to be significantly less convenient at a higher charge burden than did patients whose primary implant was rechargeable. Age did not have a significant impact on any endpoint. CONCLUSIONS Overall, patients with movement disorders rated recharging as easy, with low complication rates and acceptable charge burden