Processing and secretion of tumor necrosis factor alpha in endotoxin-treated Mono Mac 6 cells are dependent on phorbol myristate acetate.

摘要: Lipopolysaccharide (LPS, endotoxin) is a potent stimulator of tumor necrosis factor alpha (TNF alpha) synthesis and secretion in mouse macrophage cells (Golenbock, D. T., Hampton, R. Y., Qureshi, N., Takayama, K., Raetz, C. H. (1991) J. Biol. Chem. 266, 19490-19498). In contrast, addition LPS (10 ng/ml) to human monomyelocytic (Mono Mac 6) induces very little production TNF alpha, as judged by immunoassay the growth medium. When 30 ng/ml 4-beta-phorbol-12-myristate 13-acetate (PMA) added together with LPS, large amounts are secreted. PMA alone inactive. Maximal levels medium achieved at 1 LPS. Protein kinase C inhibitors, such H7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine), staurosporine, sphingosine, reduce stimulated PMA. The effect has been investigated each stage biogenesis. Treatment Mono 6 results rapid, transient, full expression mRNA. Concomitant does not increase mRNA any further, but it prolongs half-life about 3-fold. However, stabilization account for striking on secretion. Analysis immunoprecipitation indicates that fully effective stimulating formation intracellular 26-kDa precursor. sufficient allow processing precursor mature 17-kDa alpha. rate observed immediately after LPS-pretreated similar maximum from LPS/PMA-treated cells, without lag being exposed simultaneously. summary, required completion LPS-treated whereas murine RAW able complete terminal steps absence