FIGURE 3.

LT cotreatment enhances TNF-induced IKK activity and phosphorylation and MEKK2 expression. A, IKK activity assay was performed as described under “Experimental Procedures.” Where indicated, lysates were incubated for 30 min with TPCA-1 (3 μm) prior to assay. Graph represents Western blot densitometry for three sets of 6-h samples. B, whole cell lysates were analyzed by Western blot for p-IKKα/β and total IKKα levels. At least three blots were performed. Blots are shown for a representative set of 10-min and 2-h samples grouped on one gel and the 6-, 12-, and 24-h samples grouped on a second gel. Graphs represent Western blot densitometry (n ≥3). Data were normalized relative to cells treated with medium alone and presented as means ± S.E. C, whole cell lysates were analyzed by Western blot for expression of MEKK2. A representative blot of four blots is shown. NC, negative control for IKK activity assay (no cell lysates); M, medium; L, LT; T, TNF; L + T, LT + TNF. ††, p < 0.01 versus TNF; †, p < 0.05 versus TNF.