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SHR Neuro Krebs Kardio Lipid

Mayerhofer, R; Fröhlich, EE; Reichmann, F; Farzi, A; Kogelnik, N; Fröhlich, E; Sattler, W; Holzer, P.
Diverse action of lipoteichoic acid and lipopolysaccharide on neuroinflammation, blood-brain barrier disruption, and anxiety in mice.
Brain Behav Immun. 2017; 60:174-187 [OPEN ACCESS]
Web of Science PubMed PUBMED Central FullText FullText_MUG

 

Autor/innen der Med Uni Graz:
Farzi Aitak
Fröhlich Eleonore
Fröhlich Esther Eleonore
Holzer Peter
Kogelnik Nora
Mayerhofer Raphaela
Reichmann Florian
Sattler Wolfgang
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Number of Figures: 7
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Abstract:
Microbial metabolites are known to affect immune system, brain, and behavior via activation of pattern recognition receptors such as Toll-like receptor 4 (TLR4). Unlike the effect of the TLR4 agonist lipopolysaccharide (LPS), the role of other TLR agonists in immune-brain communication is insufficiently understood. We therefore hypothesized that the TLR2 agonist lipoteichoic acid (LTA) causes immune activation in the periphery and brain, stimulates the hypothalamic-pituitary-adrenal (HPA) axis and has an adverse effect on blood-brain barrier (BBB) and emotional behavior. Since LTA preparations may be contaminated by LPS, an extract of LTA (LTAextract), purified LTA (LTApure), and pure LPS (LPSultrapure) were compared with each other in their effects on molecular and behavioral parameters 3h after intraperitoneal (i.p.) injection to male C57BL/6N mice. The LTAextract (20mg/kg) induced anxiety-related behavior in the open field test, enhanced the circulating levels of particular cytokines and the cerebral expression of cytokine mRNA, and blunted the cerebral expression of tight junction protein mRNA. A dose of LPSultrapure matching the amount of endotoxin/LPS contaminating the LTAextract reproduced several of the molecular and behavioral effects of LTAextract. LTApure (20mg/kg) increased plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 and interferon-γ, and enhanced the transcription of TNF-α, interleukin-1β and other cytokines in the amygdala and prefrontal cortex. These neuroinflammatory effects of LTApure were associated with transcriptional down-regulation of tight junction-associated proteins (claudin 5, occludin) in the brain. LTApure also enhanced circulating corticosterone, but failed to alter locomotor and anxiety-related behavior in the open field test. These data disclose that TLR2 agonism by LTA causes peripheral immune activation and initiates neuroinflammatory processes in the brain that are associated with down-regulation of BBB components and activation of the HPA axis, although emotional behavior (anxiety) is not affected. The results obtained with an LTA preparation contaminated with LPS hint at a facilitatory interaction between TLR2 and TLR4, the adverse impact of which on long-term neuroinflammation, disruption of the BBB and mental health warrants further analysis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Find related publications in this database (Keywords)
Anxiety
Brain
Corticosterone
Cytokines
Lipopolysaccharide
Lipoteichoic acid
Neuroinflammation
Tight junction-associated proteins
Toll-like receptors
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