Figure 4.

The FTase-ERK pathway contributes to IL-6 expression in cardiac fibroblasts. Quiescent fibroblasts derived from the old MSCs were treated with 100 nM FTI-277 (FTI) or 2μM PD 0325901 (PD) for 24 h. A–C) IL-6 mRNA level (A), IL-6 secretion (B), and cytoplasmic IL-6 (C) are shown. To visualize cytoplasmic IL-6 cells were treated with 10 ng/ml brefeldin A for 6 h. Scale bar, 50 μm. P < 0.05 denotes statistical significance; the number in each column corresponds to the number of donor animals from which cells were derived for these experiments. For immunofluorescence staining treated cells from 3 independent experiments were analyzed.