Ghrelin promotes nuclear factor kappa-B activation in a human B-lymphocyte cell line

Ghrelin, an orexigenic hormone of gastric origin that stimulates growth hormone secretion, may modulate inflammation. This experimental study examines the effect of ghrelin on NF kappa B (p65 subunit), a transcriptional factor involved in inflammation on a human B-lymphocyte cell (WILCL). After confirming the expression of ghrelin receptor protein using western blotting the cells were transferred to wells maintaining a density of 1 x 10(6) cells per ml and a proportion activated with phytohaemagluttinin. Activated and resting cells were exposed to octanoyl-, desoctanoyl ghrelin and a non-peptide ghrelin agonist (Pfizer CP-464709) in increasing concentrations for 6 h. Cell protein extracts were analyzed for NF kappa B activation using Trans AM NF kappa B p65 assay. IL-6, IL-8, IL-10, IL-13 and TNF alpha were measured in the media using Lincoplex human cytokine assay. In octanoyl ghrelin treated resting cells, NF kappa B activity (Optical Density OD450nm) (mean +/- A SEM) in control cells was 0.42 +/- A 0.10 and increased to 0.61 +/- A 0.20 (P = 0.044), 0.54 +/- A 0.10 (P = 0.043), 0.52 +/- A 0.08 at 1, 10 and 100 nM concentrations respectively. No effect was detected with desoctanoyl ghrelin or ghrelin agonist and no specific change in cytokine production. In conclusion, Octanoyl ghrelin increased NF kappa B activation by up to 50% in a B-lymphocyte cell line suggesting an effect on the inflammatory process.