Changes in cell morphology induced by the combination of tumor necrosis factor alpha (TNF-α) + epidermal growth factor (EGF) are partially reduced by inhibition of MEK1/2. (a) Confluent monolayers of chondrocytes were pretreated with U0124 (10 μM) or U0126 (10 μM) for 15 min followed by 24-hour treatment with TNF-α (30 ng/ml), EGF (10 ng/ml) or TNF-α + EGF. Digital images of live cultures were captured at 20 × objective magnification. Bar = 100 μm. Images are representative of two independent experiments. (b) An elongated cell is defined as having a predominant axis with a length exceeding three times the maximum width of the cell. The total number of elongated cells per field (1.376 mm2) were counted, averaged for three independent experiments (n = 3), and analyzed by analysis of variance. a Significant difference from respective control (P < 0.05), b significant difference from respective control (P < 0.001), c significant difference from U0124 + EGF-treated cells (P < 0.01), d significant difference from U0124 + EGF-treated cells (P < 0.05), e significant difference from U0124 + TNF-α + EGF-treated cells (P < 0.001).