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Blood‐Brain Barrier Disruption Following Hypoxic Stress Requires Activation of Myosin Light Chain Kinase
Author(s) -
Brown Rachel C,
Hicks Kali D,
O'Neil Roger G
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.1020.3
Subject(s) - myosin light chain kinase , tight junction , microbiology and biotechnology , stress fiber , myosin , cytoskeleton , occludin , actin cytoskeleton , barrier function , actin , chemistry , rho associated protein kinase , paracellular transport , blood–brain barrier , biology , kinase , cell , biochemistry , permeability (electromagnetism) , endocrinology , membrane , central nervous system
When blood‐brain barrier (BBB) endothelial cells are exposed to hypoxic stress for prolonged periods of time, they undergo a morphological change and round up, disrupting cell‐cell junctions which leads to increased paracellular permeability. In this study, we investigated the hypothesis that myosin light chain kinase (MLCK) is integral to this process, and investigated alterations in tight junction structure after hypoxic stress. iTRAQ proteomic analysis identified a number of proteins in BBB endothelial cells that are involved in modulation of the actin cytoskeleton that were significantly altered after 6 hrs of hypoxia. Western blotting confirmed the changes in actin, moesin and vasodilatory stimulated phosphoprotein (VASP). We treated cells with ML‐7, a selective MLCK inhibitor, and assessed barrier function; ML‐7 completely blocked the hypoxia‐induced barrier disruption seen in untreated monolayers. This protection of BBB integrity was correlated with a prevention of stress fiber formation and decreased ZO‐1 expression at tight junction sites, implicating contraction of the actin‐myosin cytoskeleton in BBB disruption following hypoxic stress.