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Helicobacter pylori protein JHP0290 exhibits proliferative and anti-apoptotic effects in gastric epithelial cells.

Tavares R, Pathak SK - PLoS ONE (2015)

Bottom Line: JHP0290 existed in monomeric and dimeric forms in H. pylori cell extracts and culture broth.Recombinant purified JHP0290 (rJHP0290) also showed monomeric and dimeric forms, whereas the rJHP0290 C162A mutant exhibited only a monomeric form.CPT-induced caspase 3 activation was significantly reduced in the presence of rJHP0290.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.

ABSTRACT
The influence of Helicobacter pylori infection on gastric epithelial cell proliferation, apoptosis and signaling pathways contributes to the development of infection-associated diseases. Here we report that JHP0290, which is a poorly functionally characterized protein from H. pylori, regulates multiple responses in human gastric epithelial cells. The differential expression and release of JHP0290 homologues was observed among H. pylori strains. JHP0290 existed in monomeric and dimeric forms in H. pylori cell extracts and culture broth. Recombinant purified JHP0290 (rJHP0290) also showed monomeric and dimeric forms, whereas the rJHP0290 C162A mutant exhibited only a monomeric form. The dimeric form of the protein was found to bind more efficiently to gastric epithelial cells than the monomeric form. The exposure of gastric epithelial cells to rJHP0290 induced proliferation in a dose-dependent manner. Faster progression into the cell cycle was observed in rJHP0290-challenged gastric epithelial cells. Furthermore, we detected an anti-apoptotic effect of rJHP0290 in gastric epithelial cells when the cells were treated with rJHP0290 in combination with Camptothecin (CPT), which is an inducer of apoptosis. CPT-induced caspase 3 activation was significantly reduced in the presence of rJHP0290. In addition, the activation of ERK MAPK and the transcription factor NFκB was observed in rJHP0290-challenged gastric epithelial cells lines. Our results suggest that JHP0290 may affect H. pylori-induced gastric diseases via the regulation of gastric epithelial cell proliferation and anti-apoptotic pathways.

No MeSH data available.


Related in: MedlinePlus

rJHP0290 activates ERK MAPK in gastric epithelial cells.AGS (A) and MKN45 (B) cells were treated with rJHP0290 for various time points (min) as indicated in the figure legends. Cell lysates were prepared and immunoblotted with anti-phospho-ERK antibody followed by reprobing with anti-ERK and anti-actin antibody to confirm equal loading. Blot shown is representative of results obtained in five independent experiments. The graph shows the western blot band intensities normalized to the actin control in five experiments. Statistically significant differences are indicated by * (p < 0.05).
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pone.0124407.g007: rJHP0290 activates ERK MAPK in gastric epithelial cells.AGS (A) and MKN45 (B) cells were treated with rJHP0290 for various time points (min) as indicated in the figure legends. Cell lysates were prepared and immunoblotted with anti-phospho-ERK antibody followed by reprobing with anti-ERK and anti-actin antibody to confirm equal loading. Blot shown is representative of results obtained in five independent experiments. The graph shows the western blot band intensities normalized to the actin control in five experiments. Statistically significant differences are indicated by * (p < 0.05).

Mentions: ERK signaling pathways have been demonstrated to regulate H. pylori-induced proliferation in gastric epithelial cells [23, 31]. Therefore, we studied the activation of ERK after rJHP0290 challenge in both the AGS and MKN45 cell lines. Our results indicated that rJHP0290 induced the activation of ERK in a time-dependent manner (Fig 7A and 7B). The ERK activation kinetics was different in the two cell lines. In AGS cells, ERK activation could be detected as early as 30 min and peaked at 45 min, followed by a gradual reduction over a period of 120 min (Fig 7A). However, in the case of MKN45 cells, maximum activation was detected at 60 min (Fig 7B). A densitometry analysis of ERK phosphorylation kinetics from five independent experiments is shown in Fig 7A and 7B.


Helicobacter pylori protein JHP0290 exhibits proliferative and anti-apoptotic effects in gastric epithelial cells.

Tavares R, Pathak SK - PLoS ONE (2015)

rJHP0290 activates ERK MAPK in gastric epithelial cells.AGS (A) and MKN45 (B) cells were treated with rJHP0290 for various time points (min) as indicated in the figure legends. Cell lysates were prepared and immunoblotted with anti-phospho-ERK antibody followed by reprobing with anti-ERK and anti-actin antibody to confirm equal loading. Blot shown is representative of results obtained in five independent experiments. The graph shows the western blot band intensities normalized to the actin control in five experiments. Statistically significant differences are indicated by * (p < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400171&req=5

pone.0124407.g007: rJHP0290 activates ERK MAPK in gastric epithelial cells.AGS (A) and MKN45 (B) cells were treated with rJHP0290 for various time points (min) as indicated in the figure legends. Cell lysates were prepared and immunoblotted with anti-phospho-ERK antibody followed by reprobing with anti-ERK and anti-actin antibody to confirm equal loading. Blot shown is representative of results obtained in five independent experiments. The graph shows the western blot band intensities normalized to the actin control in five experiments. Statistically significant differences are indicated by * (p < 0.05).
Mentions: ERK signaling pathways have been demonstrated to regulate H. pylori-induced proliferation in gastric epithelial cells [23, 31]. Therefore, we studied the activation of ERK after rJHP0290 challenge in both the AGS and MKN45 cell lines. Our results indicated that rJHP0290 induced the activation of ERK in a time-dependent manner (Fig 7A and 7B). The ERK activation kinetics was different in the two cell lines. In AGS cells, ERK activation could be detected as early as 30 min and peaked at 45 min, followed by a gradual reduction over a period of 120 min (Fig 7A). However, in the case of MKN45 cells, maximum activation was detected at 60 min (Fig 7B). A densitometry analysis of ERK phosphorylation kinetics from five independent experiments is shown in Fig 7A and 7B.

Bottom Line: JHP0290 existed in monomeric and dimeric forms in H. pylori cell extracts and culture broth.Recombinant purified JHP0290 (rJHP0290) also showed monomeric and dimeric forms, whereas the rJHP0290 C162A mutant exhibited only a monomeric form.CPT-induced caspase 3 activation was significantly reduced in the presence of rJHP0290.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.

ABSTRACT
The influence of Helicobacter pylori infection on gastric epithelial cell proliferation, apoptosis and signaling pathways contributes to the development of infection-associated diseases. Here we report that JHP0290, which is a poorly functionally characterized protein from H. pylori, regulates multiple responses in human gastric epithelial cells. The differential expression and release of JHP0290 homologues was observed among H. pylori strains. JHP0290 existed in monomeric and dimeric forms in H. pylori cell extracts and culture broth. Recombinant purified JHP0290 (rJHP0290) also showed monomeric and dimeric forms, whereas the rJHP0290 C162A mutant exhibited only a monomeric form. The dimeric form of the protein was found to bind more efficiently to gastric epithelial cells than the monomeric form. The exposure of gastric epithelial cells to rJHP0290 induced proliferation in a dose-dependent manner. Faster progression into the cell cycle was observed in rJHP0290-challenged gastric epithelial cells. Furthermore, we detected an anti-apoptotic effect of rJHP0290 in gastric epithelial cells when the cells were treated with rJHP0290 in combination with Camptothecin (CPT), which is an inducer of apoptosis. CPT-induced caspase 3 activation was significantly reduced in the presence of rJHP0290. In addition, the activation of ERK MAPK and the transcription factor NFκB was observed in rJHP0290-challenged gastric epithelial cells lines. Our results suggest that JHP0290 may affect H. pylori-induced gastric diseases via the regulation of gastric epithelial cell proliferation and anti-apoptotic pathways.

No MeSH data available.


Related in: MedlinePlus