Lipopolysaccharide induced Interleukin-6 production is mediated through activation of ERK 1/2, p38 MAPK, MEK, and NFκB in chicken thrombocytes

Thrombocytes express Toll-like receptor 4 and apparently use both mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB) pathways for nuclear signaling. However, it is not well known if the same enzyme systems found in mammalian cells are fully functional in chickens. Therefore, kinase inhibitors were used with thrombocytes to block kinases in lipopolysaccharide (LPS) stimulated cells to determine if interleukin (IL)-6 expression and production would be diminished. Results demonstrated that extracellular-signal-regulated kinase (ERK)1/2 and p38 MAPK pathways influence gene expression of IL-6 through treatment with either ERK or p38 MAPK inhibitor. In addition, thrombocyte lysates from cells treated with ERK, p38, mitogen-activated protein kinase kinase (MEK)1/2 and inhibitor of nuclear factor kappa-B kinase (IKK) inhibitor showed different levels of the phosphorylated form of ERK1/2, p38 and NFκB. Furthermore, IL-6 gene expression and production were significantly upregulated in LPS stimulated thrombocytes relative to all inhibitor-treated cells.