Figure 4.

Role of phycocyanin intervention on the activity of the MAPK signaling pathway upon Hp infection in AGS cells. (A) The relative expression of DUPS2, GADD45A, FOSB, FOSL, MAP3K4 transcripts in AGS cells 8 h after Hp infection was assessed by RT-qPCR. The mRNA levels were normalized to GAPDH levels. (B) Cells were infected with Hp at the indicated ratio of 50:1 (cells/bacteria) for 12 h. Western blot was used to detect phosphorylation-specific and overall MAPK (ERK1/2, JNK1/2, p38) levels in whole-cell lysates (**, P<0.01 vs. NC group; ^#, P<0.05; ^##, P<0.01 vs. Hp group). NC, AGS cells were neither infected with Hp nor pretreated with phycocyanin; PC, cells were pretreated with 150 µM phycocyanin only; Hp, cells were infected at 50:1 (cells/bacteria) for 12 h; PC + Hp, AGS cells pretreated with 150 µM phycocyanin for 24 h and infected with Hp. Experiments were performed in triplicate for each data set. GAPDH was used as an internal control. JNK; c-Jun N-terminal kinase; p-JNK, phosphorylated JNK; ERK, extracellular signal-regulated kinase; p-ERK, phosphorylated ERK; p38MAPK, p38 Mitogen-activated protein kinase; p-p38, phosphorylated p-p38; RT-qPCR, quantification analysis by real-time quantitative polymerase chain reaction.