Staphylococcus aureus infected embolic stroke upregulates Orm1 and Cxcl2 in a rat model of septic stroke pathology

Lærke Boye Astrup, Kerstin Skovgaard, Rune Skovgaard Rasmussen, Tine Moesgaard Iburg, Jørgen Steen Agerholm, Bent Aalbæk, Henrik Elvang Jensen, Ole Lerberg Nielsen, Flemming Fryd Johansen, Peter Mikael Helweg Heegaard, Páll Skúli Leifsson*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

10 Citations (Scopus)

Abstract

Objective: Ischaemic brain lesions and brain abscesses are frequent in both human and animal cases of septic embolic stroke. However, existing models of brain infection do not reflect central aspects of septic embolic stroke. Our aim was to compare septic and non-septic embolic stroke in order to identify gene expressions, inflammatory mediators and brain damage in a rat model. Methods: We created precisely located focal brain infarcts in a rat model of Staphylococcus aureus infected embolic stroke. To cause septic embolic stroke we used a fibrin-rich embolus with bacteria, while every rat in the control group received a non-infected embolus. 64 rats were randomized to receive sham-surgery, sterile embolic stroke or septic embolic stroke. All groups were compared for brain pathology, mortality, gene expressions and inflammatory mediators using histology and reverse transcription quantitative real-time PCR. Results: Although infarct volumes did not differ, septic embolic stroke caused higher mortality than sterile embolic stroke (p=  0.002). Brain abscesses were observed only in the septic group. Approximately 400–500 fold increases were observed for Orm1 and Cxcl2 respectively (1.00E-08 < p < 1.92E-07) in the septic group compared to the sterile group, and these were the most dramatically regulated genes in septic embolic stroke compared to sterile embolic stroke. Conclusions: Septic embolic stroke caused brain abscesses, increased mortality and upregulated Orm1 and Cxcl2 gene expressions compared to non-infected embolic stroke. The dramatic Orm1 increase observed in the septic group is unprecedented and suggests a significant biological role of Orm1 during septic neuroinflammation.

Original languageEnglish
JournalNeurological Research
Volume41
Issue number5
Pages (from-to)399-412
Number of pages14
ISSN0161-6412
DOIs
Publication statusPublished - 2019

Keywords

  • abscess
  • animal model
  • Embolic stroke
  • gene expressions
  • neuroinflammation
  • septic

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