Effect of Helicobacter pylori infection and eradication on gastric epithelial cell proliferation and apoptosis

Effect of Helicobacter pylori infection and its eradication on gastric regenerating atypia in 22 133 subjects

BACKGROUND AND AIM

The aim of this study was to identify factors affecting persistent gastric regenerating atypia and determine the effect of Helicobacter pylori eradication on the course of this lesion.

METHODS

In cross-sectional setting, comprehensive health check-up subjects who underwent both endoscopy and H. pylori test from 2001 to 2009 were included. The association between H. pylori and gastric regenerating atypia was evaluated. In cohort setting, patients with regenerating atypia who underwent H. pylori test from 2001 to 2013 were included. Factors affecting positive pathology (persistent regenerating atypia or new development of neoplasm) in patients with regenerating atypia at baseline were investigated.

RESULTS

In cross-sectional setting, regenerating atypia was observed in 1.1% (241/22 133). H. pylori infection was associated with gastric regenerating atypia (adjusted odds ratio, 1.47; 95% confidence interval [CI], 1.12-1.91). In cohort setting, 310 patients with regenerating atypia were finally eligible. Positive pathology rate during follow up was 16.1% (15/93) in the persistent infection group, 2.8% (3/106) in successful eradication group, and 4.5% (5/111) in baseline H. pylori-negative group. Persistent H. pylori infection increased the risk of positive pathology (adjusted risk ratio [RR], 7.18; 95% CI, 1.95-26.48) compared to H. pylori eradication group. Persistent H. pylori infection increased the risk of regenerative atypia (adjusted RR, 5.70; 95% CI, 1.46-22.17) and new neoplasm (adjusted RR, 10.74; 95% CI, 1.10-105.17) compared to baseline negative H. pylori.

CONCLUSIONS

H. pylori infection is an independent risk factor for gastric regenerating atypia. Eradication of H. pylori seems helpful for regression of regenerating atypia.

Analyzing the influence of gastric intestinal metaplasia on gastric ulcer healing in Helicobacter pylori-infected patients without atrophic gastritis

BACKGROUND

Gastric epithelial hyper-proliferation was reported in patients with Helicobacter pylori (H. pylori)-infected gastric mucosa with intestinal metaplasia (IM) changes. In patients with gastric ulcer (GU) and IM, the GU may have a different healing rate in comparison to patients without IM. This study aimed to compare the difference in GU healing between H. pylori-infected patients with IM and those without IM.

METHODS

We retrospectively analyzed patients at the Keelung Chung Gung Memorial Hospital during the period from March 2005 to January 2011. The inclusion criteria were: 1) endoscopic findings of GU and biopsy histological examination plus rapid urease test indicating H. pylori infection; 2) gastric IM adjacent to a GU but with no atrophic gastritis changes; 3) patients receiving H. pylori eradication triple therapy and 8 weeks of maintenance therapy with a proton pump inhibitor; and 4) patients receiving follow-up endoscopy within the 3^rd and the 4^th months after treatment.

RESULTS

In total, 327 patients with GU and H. pylori infection (136 with IM and 191 without IM) were included. Patients with IM had a higher GU healing rate than those without IM (91.9% vs. 84.3%, P = 0.040). Multivariate logistical regression analysis revealed that failure of H. pylori eradication (Odds = 4.013, 95% CI: 1.840-8.951, P < 0.001) and gastric IM (Odds = 0.369, 95% CI: 0.168-0.812, P = 0.013) were the predictors of non-healing GU following treatment.

CONCLUSIONS

Patient with gastric IM change may have a higher GU healing rate than those without gastric IM. However, successful H. pylori eradication is a more important factor for GU healing than gastric IM.

Eradication of Helicobacter pylori Infection Restores ki67, p53, and Cyclin D1 Immunoreactivity in the Human Gastric Epithelium

INTRODUCTION

We evaluated the effect of Helicobacter pylori (HP) eradication on p53, cyclin D1 expression, and cell proliferation in gastric mucosa.

MATERIALS AND METHODS

We assessed p53, cyclin D1, and ki67 immunoexpression in gastric mucosa from 31 HP chronic gastritis patients and 12 controls. Reassessment was performed 6 months after successful HP eradication.

RESULTS

Successful eradication resulted in significant decrease of p53 (1.53 ± 0.16 vs 0.83 ± 0.19, P = 0.01) and ki67 (9.84 ± 0.96 vs 4.77 ± 0.27, P < 0.001) staining in the antrum. Similarly, p53 immunoreactivity significantly decreased in the corpus (1.27 ± 0.20 vs 0.46 ± 0.15, P = 0.02), while there was a trend for decreased corpus cyclin D1 and ki67 expression (0.17 ± 0.07 vs 0.0, P = 0.08 and 8.71 ± 1.24 vs 5.85 ± 0.54, P = 0.09, respectively). Importantly, after successful HP eradication, the immunoreactivity of the studied parameters was similar to that of controls.

CONCLUSION

Successful HP infection eradication restores p53, cyclin D1, and ki67 immunoreactivity in the gastric mucosa to the level of controls.

Dynamics of cell proliferation and apoptosis reflect different life strategies in hydrothermal vent and cold seep vestimentiferan tubeworms

Deep-sea vestimentiferan tubeworms, which live in symbiosis with bacteria, exhibit different life strategies according to their habitat. At unstable and relatively short-lived hydrothermal vents, they grow extremely fast, whereas their close relatives at stable and long-persisting cold seeps grow slowly and live up to 300 years. Growth and age differences are thought to occur because of ecological and physiological adaptations. However, the underlying mechanisms of cell proliferation and death, which are closely linked to homeostasis, growth, and longevity, are unknown. Here, we show by immunohistochemical and ultrastructural cell cycle analyses that cell proliferation activities of the two species studied are higher than in any other characterized invertebrate, being only comparable with tumor and wound-healing processes. The slow growth in Lamellibrachia luymesi from cold seeps results from balanced activities of proliferation and apoptosis in the epidermis. In contrast, Riftia pachyptila from hydrothermal vents grows fast because apoptosis is down-regulated in this tissue. The symbiont-housing organ, the trophosome, exhibits a complex cell cycle and terminal differentiation pattern in both species, and growth is regulated by proliferation. These mechanisms have similarities to the up- and down-regulation of proliferation or apoptosis in various types of tumor, although they occur in healthy animals in this study, thus providing significant insights into the underlying mechanisms of growth and longevity.

Effects of rabbit serum containing Yiqi Qingre Formula and its decomposed recipes on type I Helicobacter pylori-induced apoptosis of GES-1 cells in vitro

AIM: To observe the effects of rabbit serum containing Qi-replenishing heat-clearing formula (Yiqi Qingre Formula) and its decomposed recipes on type ⅠHelicobacter pylori (H pylori) -induced GES-1 cell apoptosis and to explore its mechanism.

METHODS: Rabbit sera saline, containing amoxicillin, Yiqi Qingre Formula, Huangqi or Huangqin were prepared. The model of type Ⅰ H pylori-induced GES-1 cell injury was established and co-cultured with the individually complete culture fluid of 100 mL/L rabbit serum for 48 h. Then, cells were collected and fixed, followed by identification of apoptosis using flow cytometry and Hoechst33258 fluorescent staining.

RESULTS: Apoptosis rate of type ⅠH pylori-infected GES-1 cells remarkedly increased in the saline group, while it was decreased either by amoxicillin, Yiqi Qingre Formula, Huangqi or Huangqin (1.3633 ± 0.4229, 2.1925 ± 0.6779, 1.7967 ± 0.6987, 1.4740 ± 0.4156 vs 16.6229 ± 8.5087, P < 0.01 or 0.05). The coincidence rate determined using flow cytometry and Hoechst33258 fluorescent staining was high.

CONCLUSION: Yiqi Qingre Formula has the effects of alleviating type ⅠH pylori-induced gastric epithelial cell injury through inhibition of cell apoptosis, thus maintaining cell growth.

Effects of Helicobacter pylori infection on gastric epithelial cell kinetics in patients with chronic renal failure

AIM

To evaluate the effects of Helicobacter pylori infection on gastric epithelial cell kinetics in patients with chronic renal failure (CRF).

METHODS

Forty-four patients were enrolled in this study and divided into four groups with respect to their Helicobacter pylori (H pylori) and CRF status. Groups were labeled as follows: 1a: normal renal function, H pylori negative (n = 12), 1b: normal renal function, H pylori positive (n = 11), 2a: CRF, H pylori negative (n = 10), 2b: CRF, H pylori positive (n = 11). Upper gastrointestinal endoscopy was done in all the patients involved in the study. During endoscopical investigation, antral biopsy specimens were taken from each patient. In order to evaluate the cell apoptosis and proliferation in gastric epithelial cells, Bax and proliferating cell nuclear antigen (PCNA) labeling indexes (LI) were assessed with immunohistochemical staining method.

RESULTS

For groups 1a, 1b, 2a, and 2b, mean Bax LI was identified as 34.4+/-13.7, 44.1+/-16.5, 46.3+/-20.5, 60.7+/-13.8, respectively and mean PCNA LI was identified as 36.2+/-17.2, 53.6+/-25.6, 59.5+/-25.6, 67.2+/-22, respectively. When the one-way ANOVA test was applied, statistically significant differences were detected between the groups for both Bax LI (P = 0.004 <0.01) and PCNA LI (P = 0.009 <0.01). When groups were compared further in terms of Bax LI and PCNA LI with Tukeyos HSD test for multiple pairwise comparisons, statistically significant difference was observed only between groups 1a and 2b (P = 0.006 <0.01).

CONCLUSION

In gastric epithelial cells, expression of both the pre-apoptotic protein Bax and the proliferation marker PCNA increase with H pylori infection. This increase is more evident in patients with uremia. These findings suggest that uremia accelerates apoptosis and proliferation in gastric epithelial cells.

Helicobacter pylori induces apoptosis of rat gastric epithelial cells in vitro

AIM: To investigate the effect of Helicobacter pylori (H. pylori) sonicated extract on the apoptosis of rat gastric epithelial cells as well as the expression of apoptosis-related genes in vitro.

METHODS: H. pylori sonicated extract from strain Sydney SS-1 was cultured with OUMS-37, a kind of immortalized rat gastric cell lines. Apoptosis of the cells was confirmed according to specific changes of morphology and DNA ladder 24-48 h after co-incubation. The expression of P53 protein was detected by Western blotting and the expression of bax and bcl-2 mRNA were observed by Northern blotting.

RESULTS: The specific morphology of the cells such as shrinkage, condensation, margination of nuclear chromatin and apoptotic bodies were observed under light microscope. DNA ladder was manifested by fragment analysis. Western blotting showed a dose-dependent increased expression of wild-type P53 protein and Northern blotting showed a dose-pendent increased expression of bax mRNA and reduced expression of bcl-2 mRNA in the treated cells.

CONCLUSION: H. pylori sonicated extract induces the apoptosis in vitro through up-regulation of wild-type P53 protein and bax mRNA expression, and down-regulation of bcl-2 mRNA expression, suggesting that H. pylori infection may interrupt the balance between proliferation and apoptosis of the gastric epithelial cells, which plays a key role in gastric carcinogenesis.

Long-term omeprazole and esomeprazole treatment does not significantly increase gastric epithelial cell proliferation and epithelial growth factor receptor expression and has no effect on apoptosis and p53 expression

AIM: To study the effect of proton pump inhibitor (PPI) treatment on patients with reflux esophagitis and its in vivo effect on apoptosis, p53- and epidermal growth factor receptor (EGFR) expression.

METHODS: After informed consent was obtained, gastric biopsies of the antrum were taken from patients with reflux oesophagitis prior to and after 6 mo of 20 mg omeprazole (n = 14) or 40 mg esomeprazole (n = 12) therapy. Patients did not take any other medications known to affect the gastric mucosa. All patients were Helicobacter pylori negative as confirmed by rapid urease test and histology, respectively. Cell proliferation, apoptosis, EGFR, and p53 expression were measured by immunohistochemical techniques. At least 600 glandular epithelial cells were encountered and results were expressed as percentage of total cells counted. Was considered statistically significant.

RESULTS: Although there was a trend towards increase of cell proliferation and EGFR expression both in omeprazole and esomeprazole treated group, the difference was not statistically significant. Neither apoptosis nor p53 expression was affected.

CONCLUSION: Long-term PPI treatment does not significantly increase gastric epithelial cell proliferation and EGFR expression and has no effect on apoptosis and p53 expression.

Proton pump inhibitor co-therapy normalizes the increased cell turnover of the gastric mucosa both in NSAID and selective COX-2 users

Proton pump inhibitor (PPI) co-therapy is considered the best strategy in preventing gastrointestinal complications during non-steroidal anti-inflammatory drug (NSAID) treatment, but there is limited information available on its effect on gastric mucosal cell kinetics. To evaluate the effect of PPI co-therapy on gastric mucosa we investigated epithelial cell proliferation, apoptosis, epithelial growth factor receptor (EGFR) and p53 expression in patients on chronic non-selective NSAID or cyclooxygenase-2 selective inhibitor (COX-2) treatment. Gastric biopsies of the antrum were taken from 10-10 patients on chronic NSAID and COX-2, therapy prior and after 6 months PPI co-therapy, and 10 controls without any treatment. Cell proliferation, apoptosis, EGFR and p53 expression were measured by immunohistochemistry. At least 600 glandular epithel cells were encountered and results were expressed as % of total cells counted. We found increased cell proliferation in patients on chronic COX-2 but not on NSAID therapy. Patients on either NSAID or COX-2 therapy had an increased p53 and decreased EGFR expression. PPI therapy reversed not only the increased cell proliferation and p53 expression, but also the suppressed EGFR expression when administered as co-therapy. The fewer gastrointestinal side effects observed during chronic COX-2 therapy may partially be the result of the higher cell proliferation. This effect is not mediated by the EGFR pathway. PPI co-therapy normalizes the disturbed cell kinetics irrespective of NSAID treatment used.

Cell kinetic balance in gastric mucosa with intestinal metaplasia after Helicobacter pylori eradication: 2-year follow-up study

BACKGROUND

Proliferation and apoptosis events are altered in Helicobacter pylori infection. However, whether H. pylori eradication has an effect on the disturbed kinetics in metaplastic mucosa has not been well elucidated.

AIM

To investigate the effect of eradication on the gastric cell kinetics.

SUBJECTS AND METHODS

Initially, biopsies were obtained from 74 H. pylori-infected subjects and repeated 12 and 24 months after eradication. Biopsies were immunohistochemically stained for apoptosis by single-stranded DNA, for proliferation by Ki-67 antibodies and for intestinal metaplasia MUC2, MUC5AC, MUC6 and CD10.

RESULTS

While antral apoptosis in intestinal metaplasia was significantly lower than in non-intestinal metaplasia, proliferation was significantly higher (greater and lesser curvatures, P < 0.05, respectively). This resulted in a significantly lower apoptosis/proliferation ratio in intestinal metaplasia than in non-intestinal metaplasia (antrum greater and lesser curvatures and corpus greater curvature, P < 0.05). After successful eradication, apoptosis and proliferation decreased in both intestinal metaplasia and non-intestinal metaplasia. The pattern of reduction of apoptosis and proliferation differed in these two groups. However, in the corpus, the reduction resulted in a significant increase in the apoptosis/proliferation ratio in both.

CONCLUSION

Proliferation and apoptosis are unevenly and disproportionately altered in H. pylori infection leading to an imbalance in cell kinetics. Eradication of the organism improves the balance and may possibly play a role in the prevention of malignancy transformation in the metaplastic mucosa.