Staphylococcus aureus-mediated blood-brain barrier injury: an in vitro human brain microvascular endothelial cell model.
Blood-brain barrier (BBB) disruption constitutes a hallmark event during pathogen-mediated neurological disorders such as bacterial meningitis. As a prevalent opportunistic pathogen, Staphylococcus aureus (SA) is of particular interest in this context, although our fundamental understanding of how SA disrupts the BBB is very limited. This paper employs in vitro infection models to address this. Human brain microvascular endothelial cells (HBMvECs) were infected with formaldehyde-fixed (multiplicity of infection [MOI] 0-250, 0-48 hr) and live (MOI 0-100, 0-3 hr) SA cultures. Both Fixed-SA and Live-SA could adhere to HBMvECs with equal efficacy and cause elevated paracellular permeability. In further studies employing Fixed-SA, infection of HBMvECs caused dose-dependent release of cytokines/chemokines (TNF-α, IL-6, MCP-1, IP-10, and thrombomodulin), reduced expression of interendothelial junction proteins (VE-Cadherin, claudin-5, and ZO-1), and activation of both canonical and non-canonical NF-κB pathways. Using N-acetylcysteine, we determined that these events were coupled to the SA-mediated induction of reactive oxygen species (ROS) within HBMvECs. Finally, treatment of HBMvECs with Fixed-ΔSpA (MOI 0-250, 48 hr), a gene deletion mutant of Staphylococcal protein A associated with bacterial infectivity, had relatively similar effects to Newman WT Fixed-SA. In conclusion, these findings provide insight into how SA infection may activate proinflammatory mechanisms within the brain microvascular endothelium to elicit BBB failure.
School of Biotechnology, Dublin City University, Dublin, Ireland.
Alisha
A
McLoughlin
School of Biotechnology, Dublin City University, Dublin, Ireland.
Keith D
KD
Rochfort
Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, 123 St. Stephens Green, Dublin, Ireland.
Cormac J
CJ
McDonnell
Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, 123 St. Stephens Green, Dublin, Ireland.
Steven W
SW
Kerrigan
School of Biotechnology, Dublin City University, Dublin, Ireland.
Philip M
PM
Cummins
D001422:Bacterial Adhesion; D001812:Blood-Brain Barrier / Q000293:injuries*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D042783:Endothelial Cells / Q000382:microbiology* / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D062725:Tight Junction Proteins / Q000378:metabolism
D016207:Cytokines; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D062725:Tight Junction Proteins