title: TNF-alpha reduces the level of Staphylococcus epidermidis internalization by bovine endothelial cells.
abstract: Staphylococcus epidermidis is an environmental opportunistic pathogen associated with bovine intramammary infections. In bacterial infections, the endothelial tissue plays an important role during inflammation and it is the target of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha). Therefore, this work was designed to explore the effect of TNF-alpha on the interaction of S. epidermidis with bovine endothelial cells (BEC). We show that cell signaling activated by TNF-alpha caused a marked reduction in the number of intracellular S. epidermidis, suggesting that molecules participating in this pathway were involved in the internalization of this bacterium. We also found that S. epidermidis internalization was not associated with basal levels of nuclear factor kappa B (NF-kappaB) activity because the intracellular number of bacteria recovered after treating BEC with the NF-kappaB inhibitors, SN50 or BAY 11-7083, was similar to that of the untreated control. Interestingly, inhibition of the basal activity of JNK with SP600125 and p38 with SB203580 caused a decrease in the number of intracellular S. epidermidis. These results suggest that activation of the signaling pathway initiated by TNF-alpha could play an important role in the phagocytosis of this bacterium. However, the basal activity of NF-kappaB was shown not to be important for the internalization process of S. epidermidis.
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Michoacán, Mexico.
authors.forename: Javier
authors.initials: J
authors.lastname: Oviedo-Boyso
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bravo-Patiño
authors.forename: Marcos
authors.initials: M
authors.lastname: Cajero-Juárez
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Valdez-Alarcón
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Baizabal-Aguirre
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D002417:Cattle; D015169:Colony Count, Microbial; D003593:Cytoplasm / Q000382:microbiology; D042783:Endothelial Cells / Q000382:microbiology*; D007093:Imidazoles / Q000494:pharmacology; D007155:Immunologic Factors / Q000494:pharmacology; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000276:immunology; D009570:Nitriles / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D013212:Staphylococcus epidermidis / Q000276:immunology*; D013450:Sulfones / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D000873:Anthracenes; C416282:BAY 11-7085; D007093:Imidazoles; D007155:Immunologic Factors; D016328:NF-kappa B; D009570:Nitriles; D010455:Peptides; D011725:Pyridines; C118258:SN50 peptide; D013450:Sulfones; D014409:Tumor Necrosis Factor-alpha; C432165:pyrazolanthrone; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; C093642:SB 203580