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70. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Skandinavischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

12.05. - 15.05.2019, Würzburg

Spatial distribution and proinflammatory role of extracellular RNA (eRNA) after experimental subarachnoid haemorrhage (eSAH)

Die proinflammatorische Rolle undräumliche Verteilung extrazellulärer RNA (eRNA) nach experimenteller Subarachnoidalblutung (eSAH)

Meeting Abstract

Suche in Medline nach

  • presenting/speaker Katharina Tielking - Charité – Universitätsmedizin Berlin, Berlin, Deutschland
  • Ran Xu - Charité – Universitätsmedizin Berlin, Berlin, Deutschland
  • Ulf C. Schneider - Charité – Universitätsmedizin Berlin, Berlin, Deutschland
  • Peter Vajkoczy - Charité – Universitätsmedizin Berlin, Berlin, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 70. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Skandinavischen Gesellschaft für Neurochirurgie. Würzburg, 12.-15.05.2019. Düsseldorf: German Medical Science GMS Publishing House; 2019. DocV218

doi: 10.3205/19dgnc235, urn:nbn:de:0183-19dgnc2355

Veröffentlicht: 8. Mai 2019

© 2019 Tielking et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objective: The activation of neuroinflammatory signaling is thought to play a critical role in injury progression in SAH. Previous research hypothesizes that endogenous eRNA is released upon tissue injury and consecutively, activates immune cells. This study aimed at characterizing eRNA distribution and its potential role involved in innate immunity after eSAH.

Methods: Methods: Male C57Bl/6 mice were operated utilizing a filament perforation model to generate eSAH and sham operation was done for the corresponding control groups. To confirm the bleeding, the animals received Magnetic Resonance Imaging after 24 hours. Intravenous injection of RNase 1 was used to inhibit eRNA (42 µg/kg body weight). The respective control groups were treated with saline solution. On day 1, 7 and 14, mice were sacrificed (n=6 for subgroups; ntotal=72). Confocal imaging of quadruple-immunofluorescence staining for cell nuclei (DAPI), actin, ribosomal RNA and neurons (NeuN) was used to quantify eRNA content in the subarachnoid space (SAS) and brain parenchyma. Neuroinflammatory pathways were examined by Polymerase Chain Reaction and non-amplificatory mRNA probe-based analyses of brain lysates (nCounter analysis system).

Results: eSAH led to a significant increase of eRNA in the SAS on the first postoperative day (Sham vs. SAH: 1,1* vs. 74,8*10³µm² eRNA/mm² tissue, p=0,01), and treatment with RNase 1 reduced eRNA quantity (SAH vs. SAH+RNase: 74,8* vs. 1,9*10³µm² eRNA/mm² tissue, p=0,01). On day 7, SAH animals demonstrated elevated eRNA amounts in basal (Sham vs. SAH: 0,9* vs. 3,3*10³µm² eRNA/mm² tissue, p<0,01) and periventricular (Sham vs. SAH: 0,5* vs. 1,9*10³µm² eRNA/mm² tissue, p<0,001) brain regions. eRNA levels were significantly reduced after treatment of RNase 1 in both regions (p<0,001) on day 7. Ncounter gene expression profiling with a panel of 770 neuroinflammatory genes showed clustering distinguishing Sham and SAH subgroups. Inhibiting eRNA led to downregulation of genes associated with microglia activation and polarization, including Transglutaminase 2 (SAH vs. SAH+RNase: 108 vs. 85 copies, p=0,03) and Ly6a (SAH vs. SAH+RNase: 615 vs. 474, p<0,01).

Conclusion: eRNA increases acutely in the SAS after eSAH. Over time, eRNA accumulation spreads to the parenchyma, including basal and periventricular brain regions on day 7. RNase1 treatment not only abrogates eRNA accumulation in SAS and parenchyma, but also reduces gene expression associated with inflammatory signaling.