title: Direct-contact co-culture between smooth muscle and endothelial cells inhibits TNF-alpha-mediated endothelial cell activation.
abstract: We used a direct-contact endothelial cell-smooth muscle cell (EC-SMC) co-culture to examine whether quiescent SMCs regulate the EC inflammatory response to tumor necrosis factor (TNF)-alpha. ECs were cultured under static and physiological flow conditions. Compared with TNF-alpha-treated ECs in monoculture, TNF-alpha-treated ECs in co-culture had less NF-kappaB nuclear translocation; less intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin surface protein expression; no change in TNF receptor expression, but greater Kruppel-like factor 2 (KLF2) gene expression. After flow preconditioning for 24 h at 15 dyne/cm(2), and exposure of ECs to flow and TNF-alpha for 4.5 h, ECs in co-culture had less ICAM-1, VCAM-1, and E-selectin surface protein expression. Exposure to flow greatly increased KLF2 gene expression levels in both EC cultures; as a result, ECs in co-culture and monoculture had similar levels of post-flow KLF2 gene expression. The reduced levels of TNF-alpha-induced adhesion molecule expression in co-culture required the presence of quiescent SMCs; adhesion to decellularized extracellular matrix (ECM) or co-culture with fibroblasts produced only a modest reduction in EC adhesion molecule expression. Furthermore, co-culture of quiescent SMCs and ECs on the opposite side of a 10-microm-thick porous membrane did not alter the TNF-alpha-mediated ICAM-1 surface protein expression. Although the ECM produced by SMCs plays some role in reducing TNF-alpha-mediated inflammation, these results suggest that the direct contact between ECs and quiescent SMCs is required to inhibit TNF-alpha-mediated activation.
authors.affiliation: Dept. of Biomedical Engineering, Duke Univ., Box 90281, Durham, NC 27708, USA.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Wallace
authors.forename: George A
authors.initials: GA
authors.lastname: Truskey
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002448:Cell Adhesion; D002450:Cell Communication; D049109:Cell Proliferation; D016922:Cellular Senescence; D018920:Coculture Techniques; D019040:E-Selectin / Q000378:metabolism; D042783:Endothelial Cells / Q000276:immunology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000276:immunology* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011673:Pulsatile Flow; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013314:Stress, Mechanical; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D019040:E-Selectin; D018836:Inflammation Mediators; C096161:KLF2 protein, human; D051741:Kruppel-Like Transcription Factors; D016328:NF-kappa B; D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1