Microglia increase endothelial cell death due to LPS, reversal by NOS and ROS inhibitors. While LPS did not affect bEND.3 cells alone, when cultured with BV2 cells, LPS increased cell death and monolayer disruption of primarily bEND.3 cells (Panel A, LPS) compared to control cocultures (Panel A, Control). The majority cell type that succumbed to LPS was the bEND.3 rather than BV2 cells. Treatment with aminoguanidine (Panel A, AG+), apocynin (Panel A, APO+), indomethacin (Panel A, INDO+) or minocycline (Panel A, MINO+) all prevented this monolayer disruption. To determine which cell type succumbed to LPS exposure, cocultures of bEND.3 and BV2 cells were prepared and exposed to LPS for 24 h. Immunostains of cell type markers showed that endothelial cells (Panel B, CD33, green) were primarily affected compared to BV2 cells (CD11b, red), as more BV2 cells remained post LPS treatment than bEND.3 cells. Panels C & D summarize the effect of various NOS (AG, LNMA), ROS (APO, INDO, ALO) and inflammatory (MINO) inhibitors on LPS-induced cell viability (B) and NO accumulation (C). CTL: control cultures treated with vehicle, AG: aminoguanidine (1 mM), LNMA: L-NMA (1 mM); APO: apocynin (1 mM), ALO: allopurinol (1 mM); INDO: indomethacin (50 μM). (n = 4-6 independent observations, *P < 0.05 vs. control, #P < 0.05 versus LPS.
Kacimi et al. Journal of Inflammation 2011 8:7 doi:10.1186/1476-9255-8-7