Hydrotalcite Can Prevent the Damaging Effects of Helicobacter Pylori on Gastric Epithelial Cells

CMTM3 protects the gastric epithelial cells from apoptosis and promotes IL-8 by stabilizing NEMO during Helicobacter pylori infection

BACKGROUND

CKLF-like MARVEL transmembrane domain containing 3 (CMTM3) plays an important role in cancer development. Although Helicobacter pylori (H. pylori) infection is a main cause of gastric cancer, the function of CMTM3 during H. pylori infection remains unclear. CMTM3 expression levels in tissues from H. pylori-infected patients and cells co-cultured with H. pylori were analyzed. qRT-PCR and ELISA were used to investigate the effects of CMTM3 on interleukin 8 (IL-8) expression. Annexin V/propidium iodide staining was performed to evaluate the function of CMTM3 in the apoptosis of gastric epithelial cells. Proteomic analysis was performed to explore the underlying mechanism of CMTM3 during H. pylori infection. The interaction between CMTM3 and NEMO was determined via co-immunoprecipitation, HA-ubiquitin pull-down assay, and immunofluorescence.

RESULTS

H. pylori induced a significant increase in CMTM3 expression. CMTM3 inhibited gastric mucosal epithelial cells from apoptosis and increased the expression level of IL-8 during H. pylori infection. KEGG pathway enrichment analysis revealed that differentially expressed proteins were involved in epithelial cell signaling in H. pylori infection. CMTM3 directly interacted with NEMO, which promoted protein stabilization by down-regulation of its ubiquitylation.

CONCLUSIONS

CMTM3 reduces apoptosis and promotes IL-8 expression in the gastric epithelial cells by stabilizing NEMO during H. pylori infection. These findings characterize a new role for CMTM3 in host-pathogen interactions and provide novel insight into the molecular regulation of NEMO.

Helicobacter pylori-Induced DNA Damage Is a Potential Driver for Human Gastric Cancer AGS Cells

Helicobacter pylori is a major cause of gastric cancer. This study was aimed to explore the characteristic of DNA damage induced by H. pylori infection in gastric cancer AGS cells. After infection with H. pylori, the reactive oxygen species (ROS) levels in AGS cells were significantly higher than those in the uninfected cells. Cells with longer comet tails were detected after infection with H. pylori. The number of apurinic/apyrimidinic endonuclease 1- and phosphorylated H2AX-positive cells was significantly increased compared with the number of negative control cells. The expression of pChk1 and pChk2 was significantly upregulated by H. pylori infection. Cell growth was inhibited after H. pylori infection. All these results were dose dependent. The cell alterations were more significant upon infection with H. pylori at a multiplicity of infection (MOI) of 100:1 than at an MOI of 50:1. H. pylori infection can induce DNA single-strand breaks, DNA double-strand breaks, and cell cycle checkpoint activation after ROS generation in the gastric cancer cell line AGS, which is a potential driver for gastric cancer.