Gene-Expression Profiling Suggests Impaired Signaling via the Interferon Pathway in Cstb-/- Microglia

PLoS One. 2016 Jun 29;11(6):e0158195. doi: 10.1371/journal.pone.0158195. eCollection 2016.


Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1, OMIM254800) is an autosomal recessive neurodegenerative disorder characterized by stimulus-sensitive and action-activated myoclonus, tonic-clonic epileptic seizures, and ataxia. Loss-of-function mutations in the gene encoding the cysteine protease inhibitor cystatin B (CSTB) underlie EPM1. The deficiency of CSTB in mice (Cstb-/- mice) generates a phenotype resembling the symptoms of EPM1 patients and is accompanied by microglial activation at two weeks of age and an upregulation of immune system-associated genes in the cerebellum at one month of age. To shed light on molecular pathways and processes linked to CSTB deficiency in microglia we characterized the transcriptome of cultured Cstb-/- mouse microglia using microarray hybridization and RNA sequencing (RNA-seq). The gene expression profiles obtained with these two techniques were in good accordance and not polarized to either pro- or anti-inflammatory status. In Cstb-/- microglia, altogether 184 genes were differentially expressed. Of these, 33 genes were identified by both methods. Several interferon-regulated genes were weaker expressed in Cstb-/- microglia compared to control. This was confirmed by quantitative real-time PCR of the transcripts Irf7 and Stat1. Subsequently, we explored the biological context of CSTB deficiency in microglia more deeply by functional enrichment and canonical pathway analysis. This uncovered a potential role for CSTB in chemotaxis, antigen-presentation, and in immune- and defense response-associated processes by altering JAK-STAT pathway signaling. These data support and expand the previously suggested involvement of inflammatory processes to the disease pathogenesis of EPM1 and connect CSTB deficiency in microglia to altered expression of interferon-regulated genes.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / chemistry
  • Cystatin B / genetics*
  • Gene Expression Profiling*
  • Interferons / metabolism*
  • Janus Kinase 1 / metabolism
  • Mice
  • Mice, Knockout
  • Microglia / metabolism
  • Mutation
  • Phenotype
  • STAT1 Transcription Factor / metabolism
  • Sequence Analysis, RNA
  • Signal Transduction*
  • Unverricht-Lundborg Syndrome / genetics*
  • Unverricht-Lundborg Syndrome / pathology


  • Anti-Inflammatory Agents
  • Cstb protein, mouse
  • STAT1 Transcription Factor
  • Stat1 protein, mouse
  • Cystatin B
  • Interferons
  • Jak1 protein, mouse
  • Janus Kinase 1

Grant support

This study was funded by the Folkhälsan Research Foundation, the Sigrid Jusélius Foundation (, and Academy of Finland (project 137950) (; and Epilepsiatutkimussäätiö ( and the Doctoral Programme in Biomedicine ( to I.K. Work in the J.K. laboratory was supported by the Swedish Research Council (, the Karolinska Institutet Distinguished Professor Award, Strategic Research Program funding on Diabetes to Karolinska Institutet (, and EU FP7-PEOPLE-2012-IAPP grant SARM (324509) ( The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.