Human coronary endothelial cell activation by endotoxin is characterized by NF-kappa B activation and TNF-alpha synthesis.
Tumor necrosis factor-alpha (TNF-alpha), an early inflammatory mediator typically regulated by nuclear factor kappa B (NF-kappa B), plays a critical role in the development of cardiovascular dysfunction in sepsis. While several myocardial cell types synthesize TNF-alpha, the importance of the myocardial endothelium in sepsis-related cardiac cytokine production is unclear. To determine the role of the human coronary artery endothelial cell (HCA-EC) in the cytokine response to endotoxin we measured in vitro TNF-alpha synthesis, TNF-alpha mRNA, and the associated NF-kappa B response to LPS. To determine the magnitude of the HCA-EC response we assessed the TNF-alpha and NF-kappa B response to LPS in a human monocytic cell line (THP-1) as well. We observed an increase in supernatant TNF-alpha from LPS-stimulated HCA-EC (12 h) that was ablated by the proteosome inhibitor, ALLN (N-acetyl-Leu-Leu-norleucinal). Similarly, ALLN-sensitive TNF-alpha was produced by monocytes following LPS, although at concentrations 100-fold higher than HCA-EC. TNF-alpha mRNA from HCA-EC was detected at 60 min in LPS-stimulated cells, but not in unstimulated cells or cells pretreated with ALLN. NF-kappa B p50/p65 subunits were detectable in endothelial nuclear protein 60 min following LPS. In contrast, NF-kappa B subunits from monocytes were detected at 15 min. Also, while ALLN only attenuated endothelial NF-kappa B translocation, monocyte NF-kappa B translocation was completely inhibited. These data suggest endotoxin-stimulated human coronary endothelial cells express TNF-alpha, which is regulated in part by NF-kappa B activation, in a manner and degree distinct from human monocytes.
Chan
E L
EL
Department of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9158, USA.
Haudek
S B
SB
Giroir
B P
BP
Murphy
J T
JT
D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000502:physiology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D004731:Endotoxins / Q000633:toxicity*; D006801:Humans; D007700:Kinetics; D008070:Lipopolysaccharides / Q000633:toxicity; D016328:NF-kappa B / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
D004731:Endotoxins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha