Faculty Collaboration Database

Effects of interleukin-6 on the expression of tight junction proteins in isolated cerebral microvessels from yearling and adult sheep. Neuroimmunomodulation 2013;20(5):264-73

Date

07/23/2013

Pubmed ID

23867217

Pubmed Central ID

PMC3827681

DOI

10.1159/000350470

Scopus ID

2-s2.0-84882384404 (requires institutional sign-in at Scopus site)   54 Citations

Abstract

OBJECTIVES: The blood-brain barrier is a selective diffusion barrier between brain parenchyma and the intravascular compartment. Tight junctions are integral components of the blood-brain barrier. Pro-inflammatory cytokines are important in the pathogenesis of brain injury and could modify the protein constituents of tight junctions. We hypothesized that interleukin-6 (IL-6) downregulates key protein constituents of endothelial tight junctions (e.g. occludin and claudin-5).

METHODS: We examined the effects of IL-6 on tight junction protein expression using an in vitro blood-brain barrier model. We isolated microvessels from yearling and adult ovine cerebral cortex and placed them into culture with IL-6 concentrations of 0 (control, phosphate-buffered saline), 1, 10, and 100 ng/ml for 24 h. Cerebral microvessels were harvested, Western immunoblot performed for occludin and claudin-5, densitometry performed, and results expressed as a ratio to control values.

RESULTS: Western immunoblot analysis showed that treatment with 100 ng/ml of IL-6, but not the lower concentrations, reduced (p < 0.05) occludin expression in microvessels from yearling and adult sheep and claudin-5 in microvessels from adult sheep. However, treatment with 10 ng/ml of IL-6 increased claudin-5 in microvessels from yearling sheep. The percent of lactate dehydrogenase released from the microvessels into the surrounding media was not increased by IL-6 treatment, suggesting that the reductions in tight junction proteins did not result from cell death. Treatment of adult cerebral cortical microvessels with IL-6 preincubated with anti-IL-6 monoclonal antibodies partially attenuated the reduction in claudin-5.

CONCLUSION: We conclude that IL-6 modulates tight junction protein expression in cerebral cortical microvessels from yearling and adult sheep.

Author List

Cohen SS, Min M, Cummings EE, Chen X, Sadowska GB, Sharma S, Stonestreet BS

Author

Susan Cohen MD Associate Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Age Factors
Analysis of Variance
Animals
Animals, Newborn
Antibodies
Cerebral Cortex
Dose-Response Relationship, Drug
Gene Expression Regulation
In Vitro Techniques
Interleukin-6
L-Lactate Dehydrogenase
Microvessels
Sheep
Tight Junction Proteins