Alterations in the microbiome are associated with the development of gastric cancer. Our study aimed to identify dysbiotic features in early gastric cancer (EC). The gastric microbiome was assessed in EC (n = 30), advanced gastric cancer (AC) (n = 30), and chronic gastritis (CG) (n = 60). The results demonstrated significant differences in the microbial profile and composition between EC and AC, suggesting alterations associated with gastric cancer progression. Linear discriminant analysis (LDA) effect size (LEfSe) analyses identified 32 bacterial genera that were associated with EC. Functional analyses of the gastric microbiome showed that the production of urease and synthesis of bacterial flagella were weakened in EC, while the glycolysis of fructose and hydrolysis of glycosides were enhanced. A classifier based on a random forest (RF) machine learning algorithm identified a microbial signature that distinguished EC from CG or AC with high accuracy. The correct identification of the signature was further validated in independent cohorts. This signature enriched of bacteria with varied abundance, high degree of bacterial interactions and carcinogenic potentials. Constrained principal coordinate analyses revealed that the presence of Helicobacter pylori and the cagA and vacA virulence genotypes influenced the structure of the gastric microbiome. To determine the impacts of host genetic variations on the gastric microbiome, six previously reported single nucleotide polymorphisms (SNPs) were examined. The minor allele of MUC1 rs4072037 was associated with an increased abundance of Ochrobactrum. The gastric microbiome altered in EC, which might be attributed in part to host genetic variations, H. pylori infection, bacterial virulence and environmental adaptations. The identified microbial signature could serve as biomarkers for clinical assessment of gastric cancer risk in high-risk patients.

The gastric epithelium is often exposed to injurious elements and failure of appropriate healing predisposes to ulcers, hemorrhage, and ultimately cancer. We examined the gastric function of CD36, a protein linked to disease and homeostasis. We used the tamoxifen model of gastric injury in mice null for Cd36 (Cd36-/-), with Cd36 deletion in parietal cells (PC-Cd36-/-) or in endothelial cells (EC-Cd36-/-). CD36 expresses on corpus ECs, on PC basolateral membranes, and in gastrin and ghrelin cells. Stomachs of Cd36-/- mice have altered gland organization and secretion, more fibronectin, and inflammation. Tissue respiration and mitochondrial efficiency are reduced. Phospholipids increased and triglycerides decreased. Mucosal repair after injury is impaired in Cd36-/- and EC-Cd36-/-, not in PC-Cd36-/- mice, and is due to defect of progenitor differentiation to PCs, not of progenitor proliferation or mature PC dysfunction. Relevance to humans is explored in the Vanderbilt BioVu using PrediXcan that links genetically-determined gene expression to clinical phenotypes, which associates low CD36 mRNA with gastritis, gastric ulcer, and gastro-intestinal hemorrhage. A CD36 variant predicted to disrupt an enhancer site associates (p < 10-17) to death from gastro-intestinal hemorrhage in the UK Biobank. The findings support role of CD36 in gastric tissue repair, and its deletion associated with chronic diseases that can predispose to malignancy.

The human stomach mucosa contains two main group of gastric proteinases. Both pepsinogen A (PGA) and pepsinogen C (PGC) consist of molecular variants, isozymogens, which can be separated electrophoretically, PGA was found to consist of five isozymogens (Pg1-Pg2), and PGC of two isozymogens (Pg6 and Pg7). Five hundred zymograms were examined and electrophoretic mobility of pepsinogens from patients with gastric cancer was found to be higher than from other gastric diseases. The ratio of isozymogens Pg3 to Pg5 differs in to great extent in various disease. Patients with ulcer disease have this value higher than 1, but patients with gastric cancer lower than 1. Patients with gastric ulcer have lower occurrence of Pg1 and SMP in antrum. In patients with gastric carcinoma lower concentration of PGA and also ratio PGA to PGC are observed.

Teprenone (geranylgeranylacetone) is a gastric mucosal protective drug used clinically in Japan for treatment of gastric ulcers and gastritis. Its effect on portal hypertensive (PHT) gastric mucosa which has impaired defensive mechanisms is not known. In 20 PHT and 20 sham-operated rats, we studied the effects of teprenone or placebo on: (1) portal pressure; (2) gastric pH; (3) gastric mucosal blood flow using laser doppler flowmetry, and (4) hexosamine content in gastric mucosa. The gastric mucosal blood flow was significantly higher in the PHT + teprenone group than in the PHT + placebo group (463 +/- 75 and 381 +/- 82 perfusion units, respectively; p < 0.05). The hexosamine content was significantly lower in PHT rats than in sham-operated controls (12.6 +/- 2.3 vs. 14.3 +/- 2.2 micrograms/mg, respectively). Teprenone treatment significantly increased the gastric mucosal hexosamine concentration in both sham-operated and PHT rats (17.2 +/- 3.1 and 15.6 +/- 3.6 micrograms/mg, respectively). These effects of teprenone, combined with its known prostaglandin-stimulating action, suggest a potential role for this agent in the treatment of PHT gastric mucosal abnormalities.

Not much is known about the role of gastric microbiota except for Helicobacter pylori in human health and disease. In this study, we aimed to detect human gastric microbiota in both gastric mucosa and gastric juice by barcoded 454-pyrosequencing of the 16S rRNA gene and to compare the results from mucosa and juice.

The transitional-CpG sites between weakly methylated genes and densely methylated retroelements are overmethylated in the gastric mucosa infected with Helicobacter pylori (H. pylori) and they are undermethylated in the gastric cancers depending on the level of loss of heterozygosity (LOH) events. This study delineated the transitional-CpG methylation patterns of CpG-island-containing and -lacking genes in view of the retroelements.

LASSBio-596 (2-[4-(1,4-thiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid) is a molecular hybrid of anti-tumor necrosis factor α (TNF-α) and phosphodiesterase 5 inhibitors, and its anti-inflammatory effects have been demonstrated in experimental models of inflammation. The aim of this study was to evaluate the gastroprotective effect of LASSBio-596 in an ethanol-induced acute gastritis model. Before induction of gastric damage, mice were pretreated with LASSBio-596 (20 mg per os (p.o.), Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 3 mg/kg, intraperitoneally [i.p.]) or with 1400W (10 mg/kg, i.p.) given alone or in their combinations. Thirty minutes later, gastric damage was induced by intragastric instillation of 50% ethanol (0.5 ml/25 g, by gavage). After 1 h, gastric damage (hemorrhagic or ulcerative lesions) was measured by planimetry. Samples of the stomach were also taken for histopathological assessment and for assays of tissue myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), and inflammatory cytokines. Ethanol administration induced the development of gastric lesions in mice. LASSBio-596 reduced gastric damage, epithelial cell loss and hemorrhage, and restored the antioxidant defense system by decreasing the levels of MDA and the consumption of GSH in gastric mucosa. LASSBio-596 also decreased gastric TNF-α and interleukin-1β (IL-1β) protein levels, MPO enzymatic activity, and hemoglobin levels. Treatment with the nitric oxide synthase inhibitors L-NAME and 1400W reversed the effects of LASSBio-596 on ethanol-induced gastric lesions. LASSBio-596 did not alter mucus content and pH of gastric secretions. In summary, LASSBio-596 exerts protective effects against ethanol-induced gastric injury. The gastroprotective effects of LASSBio seem to be NO-dependent.

No abstract available

The ineffective short-term control of feeding behavior compromises energy homeostasis and can lead to obesity. The gastrointestinal tract secretes several regulatory peptides. However, little is known about the stomach peptide contribution to the acute regulation of intake. In an attempt to identify new gastric signals, the serial analysis of gene expression (SAGE) method was used for the transcription profiling of stomach mucosa in 7 groups of mice: fasting and sacrificed 30 minutes, 1 hour, 3 hours after a low-fat (LF) or high-fat (HF) ad libitum meal. In total, 35 genes were differentially modulated by LF and HF meals compared to fasting, including 15 mRNAs coding for digestive enzymes/secretory proteins, and 10 novel transcripts. Although the basic expression profile did not undergo substantial variations, both LF and HF meals influenced the transcription. This study represents the first global analysis of stomach transcriptome as induced by different nutritional stimuli. Further studies including the characterization of novel genes may help to identify new targets for the therapy and prevention of obesity.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to increase the histamine release from gastric enterochromaffin-like (ECL) cells and promote gastric acid secretion in rats. In contrast, in mice, PACAP has been demonstrated to induce a decrease of gastric acid secretion, an effect presumably due to somatostatin release. To more clearly define the role of PACAP in the regulation of gastric acid output, a knockout mouse model for the PACAP-specific receptor PAC1 was applied in this study. Measurements of the basal and stimulated gastric acid secretion and morphological studies on the gastric mucosa were performed in both wild-type and PAC1-deficient mice. Compared with the wild-type mice, the PAC1-deficient mice showed a nearly threefold higher basal gastric acid output, increased gastric mucosa thickness and glands height, and proportional increases in parietal and total cell counts in the gastric mucosa. The PAC1-deficient mice also showed a trend of increased plasma gastrin levels and gastrin gene expression in the gastric mucosa. This study indicates that the expression of PAC1 is clearly important for maintaining the homeostasis of gastric acid secretion. Loss of PACAP receptor during development may lead to a compensatory mechanism regulating gastric acid secretion.

Hydrogen sulphide (H₂S) is produced endogenously via two enzymes dependent on pyridoxal phosphate (PLP): cystathionine beta-synthase (CBS, EC 4.2.1.22), cystathionase γ-liase (CTH, EC 4.4.1.1), and a third, 3-mercaptopyruvate sulfurtransferase (MPST, EC 2.8.1.2). H₂S strengthens the defence mechanisms of the gastric mucosal barrier, and plays an important role in gastroprotection, including the increased resistance to damage caused by various irritants and non-steroidal anti-inflammatory drugs. The study was conducted to determine the role of H₂S in ulcerated gastric mucosa of rats caused by immobilization in cold water (WRS). The activity and expression of γ-cystathionase, cystathionine β-synthase, 3-mercaptopyruvate sulfurtransferase, and rhodanese was compared with healthy mucosa, together with H₂S generation, and cysteine, glutathione, and cystathionine levels. The results showed that the defence mechanism against stress is associated with stimulation of the production of H₂S in the tissue and confirmed the observed advantageous effect of H₂S on healing of gastric ulcers. In case of animals pretreated with exogenous sources of H₂S and NaHS, and some changes observed in the ulcerated gastric mucosa tend to return to values found in the healthy tissue, a finding that is in accordance with the previously determined gastroprotective properties of H₂S. The results presented in this paper point to the possible role of rhodanese in H₂S production in the gastric mucosa of rats, together with the earlier mentioned three enzymes, which are all active in this tissue.

More than 90% of individuals with germline pathogenic CDH1 variants will harbor occult, microscopic foci of signet ring cell carcinomas capable of progressing to advanced diffuse-type gastric cancer. Here, we present a protocol for high viability suspension of signet ring cells from human gastric tissue. We describe the steps for gastric mucosa isolation and tissue dissociation. We then detail procedures for embedding cells into HistoGel for immunohistochemistry staining and additional applications such as flow cytometry and single-cell sequencing.

This research aimed at better understanding the histopathological development of precancerous lesions of gastric cancer (PLGC) and organelle ultrastructure changes.

Stress ulcers are complicated by severe trauma and other critical diseases, the mechanism of which remains unclear. An increasing number of studies have shown that microRNAs (miRNAs) are important regulators of stress responses such as hypoxia, abnormal temperature, and inflammation. The evidence indicates that miRNAs are also involved in regulating stress-induced ulcers. Recently, we demonstrated that gastric mucosal injury induced by aspirin is related to the reduction of glutamate levels by inhibition of cystine/glutamate transporter (xCT) activity. In the present study, the effect of a miRNA/xCT on gastric mucosal injury induced by cold stimulation was investigated. We found that cold stimulation induced gastric mucosa injury with a reduction in glutamate levels and xCT activity and upregulation of miR-143, miR-152, and miR-181 expression. Exogenous glutamate significantly alleviated gastric mucosa injury by cold stimulation. In vitro experiments demonstrated that treatment with miR-143, miR-152, or miR-181 mimics directly induced cell damage. The effects of these mimics were alleviated by exogenous glutamate. The present study suggests that miR-143, miR-152, and miR-181 are involved in cold stimulation-induced acute gastric mucosal injury. Furthermore, the regulatory effect of miRNAs on gastric mucosa injury induced by cold stimulation is related to a decrease in glutamate release by reduction of cystine/glutamate transporter activity.

Aging gastric mucosa has increased susceptibility to injury and delayed healing owing to impaired angiogenesis, but the mechanisms are not fully known. We examined whether impairment of angiogenesis in aging gastric mucosa is caused by deficiency of nerve growth factor (NGF) in gastric endothelial cells (ECs), and whether NGF therapy could reverse this impairment.

The link between microbiota and gastric cancer (GC) has attracted widespread attention. However, the phylogenetic profiles of niche-specific microbiota in the tumor microenvironment is still unclear. Here, mucosa-associated microorganisms from 62 pairs of matched GC tissues and adjacent non-cancerous tissues were characterized by 16S rRNA gene sequencing. Functional profiles of the microbiota were predicted using PICRUSt, and a co-occurrence network was constructed to analyze interactions among gastric microbiota. Results demonstrated that mucosa-associated microbiota from cancerous and non-cancerous tissues established micro-ecological systems that differed in composition, structure, interaction networks, and functions. Microbial richness and diversity were increased in cancerous tissues, with the co-occurrence network exhibiting greater complexity compared with that in non-cancerous tissue. The bacterial taxa enriched in the cancer samples were predominantly represented by oral bacteria (such as Peptostreptococcus, Streptococcus, and Fusobacterium), while lactic acid-producing bacteria (such as Lactococcus lactis and Lactobacillus brevis) were more abundant in adjacent non-tumor tissues. Colonization by Helicobacter pylori, which is a GC risk factor, also impacted the structure of the microbiota. Enhanced bacterial purine metabolism, carbohydrate metabolism and denitrification functions were predicted in the cancer associated microbial communities, which was consistent with the increased energy metabolism and concentration of nitrogen-containing compounds in the tumor microenvironment. Furthermore, the microbial co-occurrence networks in cancerous and non-cancerous tissues of GC patients were described for the first time. And differential taxa and functions between the two groups were identified. Changes in the abundance of certain bacterial taxa, especially oral microbiota, may play a role in the maintenance of the local microenvironment, which is associated with the development or progression of GC.

The purpose of this study was to characterize alterations in mucosa-associated microbiota in different anatomical locations of the stomach during gastric cancer progression and to identify associations between Helicobacter pylori infection and gastric microbial changes in patients with gastric cancer.

We have characterized an experimental model of ethanol-induced chronic gastritis in which a compensatory mucosal cell proliferation is apparently regulated by lipoperoxidative events. Therefore, the present study is an attempt to further assess the participation of oxidant stress during gastric mucosa proliferation, by administering alpha-tocopherol (vitamin E) to rats with gastritis. A morphometric analysis was done, and parameters indicative of oxidant stress, cellular proliferation (including cyclin D1 levels), apoptotic events, and activities of endogenous antioxidant systems were measured in gastric mucosa from our experimental groups. After ethanol withdrawal, restitution of surface epithelium coincided with increased lipid peroxidation and cell proliferation and further active apoptosis. High alpha-tocopherol dosing (100 IU/kg bw) showed a clear antioxidant effect, abolished cell proliferation, and promoted an early and progressive apoptosis, despite vitamin E also enhancing levels of endogenous antioxidants. Indicators of cell proliferation inversely correlated with apoptotic events, and this relationship was blunted by administering vitamin E, probably by affecting translocation of active cyclin D1 into the nucleus. In conclusion, alpha-tocopherol administration inhibited cell proliferation, leading to a predominance of apoptotic events in ethanol-induced gastric damage. Therefore, the timing and magnitude of lipoperoxidative events seemed to synchronize in vivo cell proliferative and apoptotic events, probably by changing the cell redox state.

Gastric cancer (GC), as one of the most common malignancies across the globe, is the fourth leading cause of cancer-related deaths. Though a large body of research has been conducted to develop the therapeutic methods of GC, the survival rate of advanced patients is still poor. We aimed to dig into the potential regulatory mechanism of GC progression.

Gastritis refers to inflammation caused by injury to the gastric epithelium, which is usually due to excessive alcohol consumption and prolonged use of nonsteroidal anti‑inflammatory drugs. Millions of individuals worldwide suffer from this disease. However, the lack of safe and promising treatments makes it urgent to explore and develop leads from natural resources. Therefore, food as medicine may be the best approach for the treatment of these disorders. The present study described the protective effects of food‑polydeoxyribonucleotides (f‑PDRNs) in a rat model of gastric mucosal injury induced by HCl‑EtOH. Administration of f‑PDRN was performed with low‑PRF002 (26 mg/kg/day), medium‑PRF002 (52 mg/kg/day) and high‑PRF002 (78 mg/kg/day) on the day of autopsy. The site of damage to the mucous membrane was also analysed. In addition, an increase in gastric juice pH, total acidity of gastric juice and decrease in gastric juice secretion were confirmed, and gastric juice secretion‑related factors corresponding to the administration of f‑PDRN were analysed. Administration of f‑PDRN reduced the mRNA expression of histamine H2 receptor, muscarinic acetylcholine receptor M3, cholecystokinin 2 receptor and H+/K+ ATPase related to gastric acid secretion and downregulation of histamine, myeloperoxidase and cyclic adenosine monophosphate. In addition, it was histologically confirmed that the loss of epithelial cells and the distortion of the mucosa were recovered in the group in which f‑PDRN was administered compared to the model group with gastric mucosa damage. In summary, the present study suggested that f‑PDRN has therapeutic potential and may have beneficial effects if taken regularly as a food supplement.