IL-6 Cytokines Induce STAT3 Activation in Primary Neurons and SH-SY5Y Cells. A

, Primary neurons were treated with IL-6 (10 ng/ml) plus sIL-6R (25 ng/ml) or OSM (10 ng/ml) for the times indicated. Protein lysates were prepared and subjected to immunoblot analyses with antibodies against phosphorylated STAT3 Tyr705, phosphorylated STAT3 Ser727, and total STAT3. B, SH-SY5Y cells were treated with IL-6 (10 ng/ml) plus sIL-6R (25 ng/ml) or OSM (10 ng/ml) for the times indicated, and cell lysates immunoblotted as described. The densitometric ratios of P-STAT3 Tyr705 or P-STAT3 Ser727 versus total STAT3 were calculated, and are shown as Fold Increase. Graphs represent the mean ± SEM for triplicate cultures in three separate experiments. *p<0.001, #p<0.01, and **p<0.05 compared to control, untreated cultures.