A systems approach delivers a functional microRNA catalog and expanded targets for seizure suppression in temporal lobe epilepsy.
Temporal lobe epilepsy is the most common drug-resistant form of epilepsy in adults. The reorganization of neural networks and the gene expression landscape underlying pathophysiologic network behavior in brain structures such as the hippocampus has been suggested to be controlled, in part, by microRNAs. To systematically assess their significance, we sequenced Argonaute-loaded microRNAs to define functionally engaged microRNAs in the hippocampus of three different animal models in two species and at six time points between the initial precipitating insult through to the establishment of chronic epilepsy. We then selected commonly up-regulated microRNAs for a functional in vivo therapeutic screen using oligonucleotide inhibitors. Argonaute sequencing generated 1.44 billion small RNA reads of which up to 82% were microRNAs, with over 400 unique microRNAs detected per model. Approximately half of the detected microRNAs were dysregulated in each epilepsy model. We prioritized commonly up-regulated microRNAs that were fully conserved in humans and designed custom antisense oligonucleotides for these candidate targets. Antiseizure phenotypes were observed upon knockdown of miR-10a-5p, miR-21a-5p, and miR-142a-5p and electrophysiological analyses indicated broad safety of this approach. Combined inhibition of these three microRNAs reduced spontaneous seizures in epileptic mice. Proteomic data, RNA sequencing, and pathway analysis on predicted and validated targets of these microRNAs implicated derepressed TGF-β signaling as a shared seizure-modifying mechanism. Correspondingly, inhibition of TGF-β signaling occluded the antiseizure effects of the antagomirs. Together, these results identify shared, dysregulated, and functionally active microRNAs during the pathogenesis of epilepsy which represent therapeutic antiseizure targets.
European Regional Development Fund
FutureNeuro industry partners
Science Foundation Ireland (SFI/13/IA/1891 and 12/COEN/18 and 16/RC/3948)
Marie Skłodowska-Curie Actions Individual Fellowship (“EpimiRTherapy,” H2020-MSCA-IF-2018 840262)
Marie Skłodowska-Curie Actions Individual Fellowship (“AstroMiRimage,” H2020-MSCAIF-2017 798644)
European Union’s “Seventh Framework”Programme (FP7) under Grant Agreement 602130 (EpimiRNA).
Associated research data filesThe sequencing data have been deposited to the Gene Expression Omnibus (GEO) under accession no. GSE137473 (81). The proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD019098 (82). Custom analysis codes are available on https://github.com/g-morris/Ago2Seq. All data generated or analyzed during this study are included in this published article (and its SI Appendix files).
CommentsThe original article is available at https://www.pnas.org/content
Published CitationVenø MT, Reschke CR, Morris G, Connolly NMC, Su J, Yan Y, Engel T, Jimenez-Mateos EM, Harder LM, Pultz D, Haunsberger SJ, Pal A, Heller JP, Campbell A, Langa E, Brennan GP, Conboy K, Richardson A, Norwood BA, Costard LS, Neubert V, Del Gallo F, Salvetti B, Vangoor VR, Sanz-Rodriguez A, Muilu J, Fabene PF, Pasterkamp RJ, Prehn JHM, Schorge S, Andersen JS, Rosenow F, Bauer S, Kjems J, Henshall DC. A systems approach delivers a functional microRNA catalog and expanded targets for seizure suppression in temporal lobe epilepsy. Proceedings of the National Academy of Sciences of the USA. 2020;117(27):15977-15988.
Publication Date24 June 2020
- FutureNeuro Centre
- Physiology and Medical Physics
- Neurological and Psychiatric Disorders
PublisherNational Academy of Sciences
- Published Version (Version of Record)