Estrogen protects the blood–brain barrier from inflammation-induced disruption and increased lymphocyte trafficking

•We report a novel protective action of estrogen on the BBB.•Estrogen enhances inter-endothelial cell tight junction function.•Estrogen’s actions are mediated by GPR30 signaling and phosphorylation of annexin A1.•Estrogen limits lymphocyte extravasation after challenge with inflammatory cytokines.•Estrogen limits inflammation-induced immune cell trafficking through ERβ/annexin A1 pathways.