BACKGROUND: Elevated levels of interleukin-6 (IL-6) have been identified in a variety of systemic inflammatory states that are associated with endothelial barrier dysfunction, but the specific effect of IL-6 on endothelial permeability and the mechanism of action have not been fully examined. The current study evaluated the effect of IL-6 on endothelial permeability and on the distribution of the tight junctional protein ZO-1 and cytoskeletal actin. We also assessed the role of protein kinase C (PKC) in this process. METHODS: Confluent monolayers of human umbilical vein endothelial cells (n = 6) were exposed to IL-6 (50-500 ng/ml) in the presence or absence of the PKC inhibitor Gö6976 (0.1 microM). Transendothelial electrical resistance (TEER) was measured at the onset of exposure and at 6-h intervals and compared with that of control cells using ANOVA with a Bonferroni multiple comparison test. Additional monolayers were exposed to IL-6, stained for ZO-1 and F-actin, and evaluated via fluorescence microscopy. RESULTS: Interleukin-6 increased endothelial permeability as measured by TEER in a dose- and time-dependent manner. In the presence of PKC inhibitor, the IL-6-mediated increase in permeability was attenuated (18-h TEER 73% of control with IL-6 exposure vs 95% of control with IL-6 + Gö6976 inhibitor, P < 0.01). Microscopy revealed that permeability changes were accompanied by a redistribution of the tight junctional protein ZO-1 and cytoskeletal actin, increased cell contraction, and disorganization of the intercellular borders. Conclusions. The inflammatory cytokine IL-6 is an important mediator of increased endothelial permeability via alterations in the ultrastructural distribution of tight junctions and morphologic changes in cell shape. PKC is a critical intracellular messenger in these IL-6-mediated changes. A better understanding of this mechanism should allow the determination of rational treatment strategies for endothelial barrier dysfunction which occurs in inflammatory states. (c) 2002 Elsevier Science (USA).
BACKGROUND: Elevated levels of interleukin-6 (IL-6) have been identified in a variety of systemic inflammatory states that are associated with endothelial barrier dysfunction, but the specific effect of IL-6 on endothelial permeability and the mechanism of action have not been fully examined. The current study evaluated the effect of IL-6 on endothelial permeability and on the distribution of the tight junctional protein ZO-1 and cytoskeletal actin. We also assessed the role of protein kinase C (PKC) in this process. METHODS: Confluent monolayers of human umbilical vein endothelial cells (n = 6) were exposed to IL-6 (50-500 ng/ml) in the presence or absence of the PKC inhibitor Gö6976 (0.1 microM). Transendothelial electrical resistance (TEER) was measured at the onset of exposure and at 6-h intervals and compared with that of control cells using ANOVA with a Bonferroni multiple comparison test. Additional monolayers were exposed to IL-6, stained for ZO-1 and F-actin, and evaluated via fluorescence microscopy. RESULTS:Interleukin-6 increased endothelial permeability as measured by TEER in a dose- and time-dependent manner. In the presence of PKC inhibitor, the IL-6-mediated increase in permeability was attenuated (18-h TEER 73% of control with IL-6 exposure vs 95% of control with IL-6 + Gö6976 inhibitor, P < 0.01). Microscopy revealed that permeability changes were accompanied by a redistribution of the tight junctional protein ZO-1 and cytoskeletal actin, increased cell contraction, and disorganization of the intercellular borders. Conclusions. The inflammatory cytokine IL-6 is an important mediator of increased endothelial permeability via alterations in the ultrastructural distribution of tight junctions and morphologic changes in cell shape. PKC is a critical intracellular messenger in these IL-6-mediated changes. A better understanding of this mechanism should allow the determination of rational treatment strategies for endothelial barrier dysfunction which occurs in inflammatory states. (c) 2002 Elsevier Science (USA).
Authors: Ozlem U Gurkan; Chaoxia He; Rachel Zielinski; Hamid Rabb; Landon S King; Jeffrey M Dodd-o; Franco R D'Alessio; Neil Aggarwal; David Pearse; Patrice M Becker Journal: Exp Lung Res Date: 2011-11-01 Impact factor: 2.459
Authors: Karina M Lugo-Cintrón; José M Ayuso; Bridget R White; Paul M Harari; Suzanne M Ponik; David J Beebe; Max M Gong; María Virumbrales-Muñoz Journal: Lab Chip Date: 2020-04-16 Impact factor: 6.799