MARCKS protein mediates hydrogen peroxide regulation of endothelial permeability

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 109; no. 37; pp. 14864 - 14869
• Main Authors: Jin, Benjamin Y, Lin, Alison J, Golan, David E, Michel, Thomas
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 11.09.2012; National Acad Sciences
• Subjects: Actin Cytoskeleton - metabolism; Actins; Animals; Aorta - cytology; Biological Sciences; Capillary Permeability - physiology; Cattle; Cell membranes; Cells; Cytoskeleton; cytosol; Endothelial cells; Endothelial Cells - metabolism; Fluorescent Antibody Technique; Hydrogen; hydrogen peroxide; Hydrogen Peroxide - metabolism; Immunoblotting; Intracellular Signaling Peptides and Proteins - metabolism; Membrane Proteins - metabolism; Membranes; microfilament proteins; Microfilaments; Microscopy, Confocal; Molecules; Myristoylated Alanine-Rich C Kinase Substrate; Oxidative stress; Oxidative Stress - physiology; Permeability; Phosphorylation; Physiological regulation; protein kinase C; Proteins; Reactive oxygen species; RNA, Small Interfering - genetics; signal transduction; Signal Transduction - physiology; Small interfering RNA; Stress fibers
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1204974109

Impairment of endothelial barrier function is implicated in many vascular and inflammatory disorders. One prevalent mechanism of endothelial dysfunction is an increase in reactive oxygen species under oxidative stress. Previous reports have demonstrated that hydrogen peroxide (H ₂O ₂), a highly stable reactive oxygen species that modulates physiological signaling pathways, also enhances endothelial permeability, but the mechanism of this effect is unknown. Here, we identify the actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) as a key mediator of the H ₂O ₂-induced permeability change in bovine aortic endothelial cells. MARCKS knockdown and H ₂O ₂ treatment alter the architecture of the actin cytoskeleton in endothelial cells, and H ₂O ₂ induces the phosphorylation and translocation of MARCKS from the cell membrane to the cytosol. Using pharmacological inhibitors and small interference RNA constructs directed against specific proteins, we uncover a signaling cascade from Rac1 to Abl1, phospholipase Cγ1, and PKCδ that is triggered by H ₂O ₂ and leads to MARCKS phosphorylation. Our findings establish a distinct role for MARCKS in the regulation of H ₂O ₂-induced permeability change in endothelial cells, and suggest potential new therapeutic targets for the treatment of disorders involving oxidative stress and altered endothelial permeability.