The extracted proteins were subjected to immunoblotting check details analysis with anti-phospho-JNK, -phospho-p38 and -phospho-ERK1/2 antibodies. The stripped membranes were re-probed with anti-total-JNK, -p38, -ERK1/2 antibody to detect the total level of each MAPK protein present in the samples and to control for loading quantities. JNK and p38 were phosphorylated in cells co-incubated with the WT bacteria, in comparison to samples
obtained from untreated Caco-2 cells which showed no MAPK activation (Figure 1). Strong activation of JNK and p38 was observed at the 2 h time point, but not at earlier time points. In contrast, little or no phosphorylation of JNK and p38 was detected in cells incubated for 2 h with the heat-killed WT bacteria, indicating that the induction of activation of these two MAPK is an active selleck inhibitor process of V. parahaemolyticus requiring viable bacteria. The patterns of ERK activation in response to V. parahaemolyticus were similar with lower phosphorylation signals detected. These studies indicate that V. parahaemolyticus induces activation of the
JNK, p38 and ERK MAPK signalling pathways via a mechanism requiring metabolically active bacteria. Figure 1 V. parahaemolyticus induces JNK, p38 and ERK phosphorylation in intestinal epithelial cells. Caco-2 cells were co-incubated with viable V. parahaemolyticus WT RIMD2210633 for 15, 60 or 120 min, with 50 μg/ml anisomycin for 30 min or with heat-killed SC79 cost WT V. parahaemolyticus for 2 h. Cell lysates were prepared and proteins
separated by SDS-PAGE. Following transfer of proteins to nitrocellulose membranes, the membranes were probed with anti-phospho-JNK, -phospho-p38 and -phospho-ERK1/2 antibodies. The stripped membranes were re-probed with the corresponding anti-total-MAPK antibodies to control for equivalent protein loading. A. Representative image of MAPK immunoblot. Results are representative of at least three independent experiments. B. Quantification of MAPK activation. Results are expressed as the ratio of phospho-MAPK to total MAPK and as relative to levels in Caco-2 cells alone. Results indicate mean ± standard error of the mean (SEM) of three independent experiments. **P < 0.01; ***P < 0.001 vs medium. TTSS1 Fludarabine ic50 of V. parahaemolyticus is responsible for activation of JNK, p38 and ERK in epithelial cells TTSS effectors of several pathogenic bacteria have been shown to modify MAPK activation levels in eukaryotic cells [24, 34–36]. As V. parahaemolyticus was able to induce phosphorylation of p38, JNK and ERK MAPK by an active process, we next investigated the involvement of the TTSS of V. parahaemolyticus in the activation of these MAPK. Bacteria lacking a functional TTSS1 or a functional TTSS2 were constructed by deleting the corresponding vscN gene for each secretion system.