Gene-expression profiles in gastric epithelial cells stimulated with spiral and coccoid Helicobacter pylori

Abstract

Human gastric epithelial immortalized GES-1 cells were infected with spiral and coccoid Helicobacter pylori. Scanning electron microscopy was used to determine the ability of the two forms of H. pylori to adhere to GES-1 cells. GES-1 cell apoptosis induced by coccoid and spiral H. pylori was analysed using flow cytometry. A cDNA microarray for 22 000 human genes was used to identify the gene-expression differences in GES-1 cells infected with the two forms of H. pylori, and the gene expression identified by the cDNA microarray was confirmed by RT-PCR. Scanning electron microscope observation showed that both coccoid and spiral bacteria can adhere to GES-1 cells. After 4 h infection, apoptosis induction was 27?4 % for spiral-form infection and 10?2 % for coccoid-form infection. Of 268 differentially expressed genes identified by cDNA microarray, 166 showed higher expression with the spiral H. pylori infection than with the coccoid H. pylori infection. To the best of the authors' knowledge, this is the first report that GES-1 cells infected with spiral H. pylori have higher expression of cxcl10, ccl11, ccl5, groa, TLR5, ATF3, fos, fosl2, gadd45a and myc. The cells infected with coccoid H. pylori had higher expression of survivin. The global profile of gene expression in GES-1 cells infected with coccoid and spiral H. pylori is described for the first time. INTRODUCTIONHelicobacter pylori is a prevalent Gram-negative microaerophilic bacterium that infects human gastric mucosa and causes many digestive diseases, such as chronic gastritis, peptic ulcers and gastric cancer (Nomura et al., 1991;Parsonnet et al., 1991; Graham et al., 1992). H. pylori exists in two morphological forms: an actively dividing spiral form and a non-culturable but viable coccoid form (Bode et al., 1993). Spiral H. pylori converts to the coccoid form under various unfavourable conditions, such as extended incubation (Catrenich & Maki, 1991;Reynolds & Penn, 1994), antibiotic treatment (Bode et al., 1993), nutrient deprivation (Mizoguchi et al., 1999), increased oxygen tension (Catrenich & Maki, 1991;Cellini et al., 1994), increased temperature (Shahamat et al., 1993), aerobic culture and alkaline pH (Cellini et al., 1994). Many researchers think that this morphological change may be a transitory adaptation to a particular environment as a means of species preservation, and that it may play an important role in antibiotic resistance and make the bacterium more difficult to eradicate. Also, the coccoid form might lead to difficult recovery, easy relapse and epidemic transmission (Mizoguchi et al., 1998). The spiral bacteria are the most common form found in the human stomach, but the coccoid bacteria are observed in more severely damaged regions of the gastric mucosa (Saito et al., 2003;Chan et al., 1994; Janas et al., 1995). Several reports have shown that although the coccoid form is non-culturable, it may be viable, as transcription and translation may actively take place in coccoid cells (Sisto et al., 2000;Monstein & Jonasson, 2001;Ng et al....

VGF: An inducible gene product, precursor of a diverse array of neuro-endocrine peptides and tissue-specific disease biomarkers

“…VGF mRNA was induced in the brain by erythropoietin treatment (Girgenti et al, 2009), in gastric epithelial cells upon Helicobacter pylori infection (Liu et al, 2006), and in the testis upon germ cell depletion, compared to normally very low levels in the latter organ (Xia et al, 2007). Conversely, a reduced expression of VGF mRNA was found in the carotid body upon chronic hyperoxia (Dmitrieff et al, 2011), and in breast cancer cell lines (Herná ndez-Vargas et al, 2006;Mitra et al, 2008), possibly via cancer-specific gene methylation (Ostrow et al, 2009), with an associated decrease of VGF products in the secreted proteome (Mitra et al, 2008).…”

Comparative Proteomic Analysis of Helicobacter pylori-Expressed Proteins in Gastric Epithelial Cell Apoptosis (Supplementry Material)

“…On the other hand, an increase of coccoid H. pylori morphology is suggested not capable of inducing apoptosis, certain coccoid-form cells were adhered to the AGS cells, probably as bacillus form [30]. In a later study, Liu et al observed that coccoid forms induce apoptosis in a non-significant manner in tumoral AGS cells or GES-1 gastric cells when compared with the bacillus form [31].…”

Stable isotope labeling by amino acids in cell culture based proteomics reveals differences in protein abundances between spiral and coccoid forms of the gastric pathogen Helicobacter pylori

“…In animal experiments, coccoid cells were unable to colonize the stomach mucosa of gnotobiotic piglets and induced less inflammation response in mice [19]. Gastric epithelial immortalized (GES-1) cells stimulated with coccoid H. pylori showed lower apoptosis rates and reduced production of pro-inflammatory cytokines and chemokines compared to infection with the spiral form [20]. In line with this, different gastric adenocarcinoma cell lines also react with lower inflammatory response to coccoid H. pylori [21,22].…”