Fig. 5.

Inhibition of actin-myosin contraction protects tight junction structure. Zonula occludens 1 (ZO-1) is a tight junction accessory protein that links actin filaments to the plasma membrane at tight junctions (61). After 6-h hypoxic stress, ZO-1 immunofluorescence moves away from the cell-cell border into the cytoplasm, indicating disruption of the BBB. However, in cells treated with 1 μM ML-7, a MLCK inhibitor, ZO-1 localization at the plasma membrane is preserved after 6-h hypoxia. Representative fluorescent images are shown (×63 objective).