Mkp-1 deficiency exacerbates PFKFB3 induction in Escherichia coli–infected mice. WT and Mkp-1 KO mice were infected with E. coli (O55:B5) or injected with PBS (controls) as in Figure 1. Mice were euthanized after 24 h. Hearts, kidneys, and lungs were harvested to extract soluble protein for Western blot analysis. Total and phosphorylated PFKFB3, and total and phosphorylated p38 MAPK in the hearts (A), kidneys (B), and lungs (C) of PBS-treated (control) and E. coli–infected WT and Mkp-1 KO mice were detected by Western blotting. The lung samples were also analyzed by Western blotting to detect MKP-1 expression, using a rabbit mAb (C). A mAb against GAPDH or β-ACTIN was used to control for sample loading. Each lane was from a distinct animal. Representative Western blotting results are shown. MAPK, mitogen-activated protein kinase; MKP, MAPK phosphatase; PFKFB, phosphofructo-2-kinase/fructose-2,6-biphosphatase.