Activation of thromboxane A2 receptors alters lipopolysaccharide-induced adherence of THP-1 cells.
U46619, a thromboxane A2 (TXA2) mimetic, inhibits human monocyte chemotactic responses, suggesting that TXA2, an arachidonic acid metabolite, may alter monocyte adhesion. We tested the hypothesis that TXA2 alters Lipopolysaccharide (LPS)-induced adhesion of THP-1 cells, a human monocytic leukemia cell line. Salmonella enteritidis endotoxin (1 microgram/mL) induced a significant (p < .05; n = 6) increase in the adherence of THP-1 cells (basal, 5.7 +/- 1.8 micrograms/well; LPS, 78.8 +/- 4.9 micrograms/well). Treatment of THP-1 cells with indomethacin or TXA2 receptor antagonists before LPS stimulation significantly (p < .05) enhanced adhesion, suggesting that endogenously produced TXA2 or prostaglandins alter LPS-induced THP-1 cell adhesion. TXA2 mimetics significantly decreased (p < .05; n = 5 and n = 3, respectively) LPS-induced THP-1 cell adhesion. This effect was blocked by three structurally dissimilar TXA2 receptor antagonists. These results support the hypothesis that TXA2 alters LPS-induced adhesion of THP-1 cells.
Wagner
R S
RS
Department of Physiology, Medical University of South Carolina, Charleston 29425, USA.
Halushka
P V
PV
Cook
J A
JA
D002448:Cell Adhesion / Q000187:drug effects*; D000242:Cyclic AMP / Q000096:biosynthesis; D006801:Humans; D007951:Leukemia, Myeloid / Q000378:metabolism / Q000473:pathology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D011869:Radioligand Assay; D017482:Receptors, Thromboxane / Q000819:agonists*; D013929:Thromboxane B2 / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D008070:Lipopolysaccharides; D017482:Receptors, Thromboxane; D013929:Thromboxane B2; D000242:Cyclic AMP