In vitro modeling of inflammation‐induced blood‐brain barrier dysfunction in sickle cell disease

Abstract

Patients with sickle cell disease (SCD) have a high incidence of cerebral vascular occlusion combined with inflammation. The properties of the blood‐brain barrier (BBB) in SCD are not characterized. We investigated structural and functional properties of SCD BBB using cerebrovascular endothelial cells (CVEC) from Berkeley SCD (BERK) and control C57BL/6 (WT) mice. BERK CVEC in primary cultures had normal growth potency and the ability to form cell contacts visualized by beta‐catenin and VE‐cadherin staining. BBB functions were tested by transendothelial electrical resistance (TEER) and by permeability to Alexa Fluor 488‐dextran in CVEC grown on transwell inserts. The baseline parameters of BBB functions were identical in WT and BERK CVEC. Pro‐inflammatory cytokine TNF‐alpha combined with cycloheximide (CHX) caused a time‐dependent (5–23 h) reduction in TEER and increased dextran permeability in both cell types. TNF/CHX‐induced BBB dysfunction was accompanied by loss of cell‐cell contacts, cell detachment, and by apoptosis. Antioxidant bilirubin conferred protection against TNF/CHX‐increased endothelial permeability, indicating that oxidative stress is a leading factor in inflammation‐induced BBB dysfunction in WT and SCD mice. Overall, CVEC from SCD mice maintain normal functional properties of BBB and are not hypersensitized to inflammation‐related injury. The study is supported by NIH/NINDS.