This work evaluated cellular proliferation, changes in Major Histocompatibility Complex (MHC) expression as a reflection of antigen processing, and cytokine (IL-6 & IL-8) secretion in a human astrocytoma cell line exposed to a trypomastigote-derived antigen.
As we have shown earlier, the stable adenosine analogue NECA (N6-(R)-phenylisopropyladenosine) stimulates IL-6 expression in the human astrocytoma cell line U373 MG via the A(2b) receptor.
We have investigated this role of IL-6 in a mouse model of spontaneous astrocytoma by crossbreeding glial fibrillary acidic protein (GFAP)-viral src oncogene transgenic mice with IL-6-deficient mice.
Here, we describe p38 mitogen-activated protein kinase (p38 MAPK) as a signal transduction component that operates independently from NF-kappaB activation and that mediates SP-induced IL-6 expression in the human astrocytoma cell line U373 MG. SP induced the phosphorylation of p38 MAPK within 10 min, and this activation persisted up to 30 min and was independent from p42/44 MAPKs and protein kinase C activation, which all are induced after stimulation with SP.
We therefore used human astrocytoma cells to search for signal transduction cascades and transcription factors whose inhibition suppresses IL-6 synthesis after stimulation with three different inductors, IL-1beta, SP, and histamine.
Using Northern blot analysis, we confirmed this result and also show that in addition to IL-1, TNFalpha but not IL-6 induces the transcription of cytoplasmic PTPvarepsilon and RPTPgamma in human astrocytoma cells.
To assess whether PGs are able to induce IL-6 synthesis in cells of the CNS, IL-6 mRNA and protein syntheses were measured in a human astrocytoma cell line after stimulation with different PGs.
For a better understanding of their pathogenic role, we analyzed signal transduction pathways mediating the interleukin (IL)-1 beta-induced synthesis of IL-6 and tumor necrosis factor alpha (TNF alpha) in the human astrocytoma cell line U373 MG.
In the present study, the effects of seven non-steroidal anti-inflammatory drugs (NSAIDs) on interleukin-1 beta (IL-1 beta)-induced IL-6 mRNA expression and protein synthesis in a human astrocytoma cell line were investigated.
We have studied the effects of synthetic ceramides and sphingomyelinase as possible regulators of IL-6 gene expression in a human astrocytoma cell line.
IL-1 stimulates, among others, production of interleukin-6 (IL-6), granulocyte macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha) in cultured astrocytes and astrocytoma cell lines.
In particular, an astrocytoma cell line U373MG subclone responded markedly to IL-1 with high expression levels of IL-8 and MCAF mRNA as well as IL-6 mRNA.