Increased motility of Helicobacter pylori by methylcellulose could upregulate the expression of proinflammatory cytokines in human gastric epithelial cells

Abstract

The inflammatory reaction in the human gastric mucosa to Helicobacter pylori could be initially triggered by an array of cytokines expressed in infected gastric epithelial cells. The spiral morphology and flagella of these organisms could increase their velocity in a viscous environment such as methylcellulose solution. The goal of this study was to determine whether modification of H. pylori motility could influence the expression of cytokine genes from gastric epithelial cells infected with H. pylori. Adherent human gastric epithelial cells were cultured and overlaid with methylcellulose solutions of varying viscosity. These epithelial cell layers covered with methylcellulose solution were inoculated with H. pylori. RNAs were then extracted from the gastric epithelial cells. Various cytokine gene expressions were assessed and quantified by reverse transcription-polymerase chain reaction (RT-PCR) and standard synthetic RNA. Cytokine proteins were also measured by enzyme-linked immunosorbent assay (ELISA). Expression of mRNA for interleukin(IL)-8 was upregulated in H. pylori-infected gastric epithelial cells overlaid with methylcellulose of 15 centipoise (cp) viscosity. The expression of mRNA for IL-lα, IL-8, monocyte chemotactic protein (MCP)-l and granulocyte macrophage colony-stimulating factor (GM-CSF) was also upregulated in H. pylori-infectedgastric epithelial cells overlaid with methylcellulose solution of the same viscosity. The number of molecules of the expressed cytokine transcripts also paralleled the amounts of protein secreted from gastric epithelial cells infected with H. pylori. These results suggest that methylcellulose solution (simulating the mucus layer in vivo) could increase contact of H. pylori with gastric epithelial cells by increasing its motility. This could result in the upregulation of mRNA for proinflammatory cytokines in gastric epithelial cells, therefore enhancing inflammatory reaction at H. pylori-infected sites.

Key Words:

• contact
• GM-CSF
• H. pylori
• IL-lα
• IL-8
• MCP-1
• quantitative RT-PCR
• velocity
• viscous

Additional information

Notes on contributors

C. Y. Kim

Joyce Laing works in the Department of Child and Family Psychiatry, Playfield House, Cupar, Fife, and is a Consultant Art Therapist to Psychiatric Hospitals and Prisons and Chairwoman of the Scottish Society of Art and Psychology.