Mucins,a family of heavily glycosylated proteins,present mainly in epithelial cells.They function as essential barriers for epithelium and play important roles in cellular physiological processes.Aberrant expression and glycosylation of mucins in gastric epithelium occur at pathological conditions,such as Helicobacter pylori infection,chronic atrophic gastritis,intestinal metastasis,dysplasia,and gastric cancer.This review addresses the major roles played by mucins and associated O-glycan structures in normal gastric epithelium.Further,we expound the alterations of expression patterns and glycan signatures of mucins at those pathological conditions.
Gastric Mucosa/pathology* ; Glycosylation ; Helicobacter Infections/pathology* ; Helicobacter pylori/metabolism* ; Humans ; Mucins/metabolism* ; Stomach Neoplasms/pathology*

Restraint water-immersion stress (RWIS), a compound stress model, has been widely used to induce acute gastric ulceration in rats. A wealth of evidence suggests that the central nucleus of the amygdala (CEA) is a focal region for mediating the biological response to stress. Different stressors induce distinct alterations of neuronal activity in the CEA; however, few studies have reported the characteristics of CEA neuronal activity induced by RWIS. Therefore, we explored this issue using immunohistochemistry and in vivo extracellular single-unit recording. Our results showed that RWIS and restraint stress (RS) differentially changed the c-Fos expression and firing properties of neurons in the medial CEA. In addition, RWIS, but not RS, induced the activation of corticotropin-releasing hormone neurons in the CEA. These findings suggested that specific neuronal activation in the CEA is involved in the formation of RWIS-induced gastric ulcers. This study also provides a possible theoretical explanation for the different gastric dysfunctions induced by different stressors.
Action Potentials ; drug effects ; physiology ; Analysis of Variance ; Animals ; Central Amygdaloid Nucleus ; pathology ; Corticotropin-Releasing Hormone ; metabolism ; Disease Models, Animal ; Gastric Mucosa ; pathology ; Gene Expression Regulation ; physiology ; Neurons ; physiology ; Patch-Clamp Techniques ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats ; Rats, Wistar ; Stress, Physiological ; physiology ; Stress, Psychological ; etiology ; physiopathology

OBJECTIVEVigna subterranea is widely consumed as a traditional staple food in Nigeria and some West African countries. The ethanolic seed extract of V. subterranea (EEVS) was investigated for its gastroprotective effects on aspirin plus pylorus ligation-induced gastric ulcerated rats using an in vivo assay.

METHODSGastric mucosal ulceration was induced experimentally in Groups 2 to 5 using aspirin plus pylorus ligation. Rats in Group 1 were orally pretreated with 3% Tween 80 only as normal control. Groups 2 to 5 were pretreated with 3% Tween 80 (ulcer group), 20 mg/kg of omeprazole (positive group), and 200 and 400 mg/kg of EEVS (experimental groups), respectively, once daily for 21 days before ulcer induction. Parameters including those for gastric secretions, ulcerated areas and gastric wall histology were assessed. Levels of superoxide dismutase (SOD), glutathione peroxidase (GP), and malondialdehyde (MDA) in the gastric tissue homogenate were also determined.

RESULTSPretreatment with EEVS significantly (P < 0.05) reduced the ulcer index, gastric volume and total acidity in rats with aspirin plus pylorus ligation-induced ulcer. The pH and mucus of gastric content increased significantly (P < 0.05) while the levels of SOD and GP were observed to be elevated with a reduced amount of MDA. Significant severe gastric mucosal injury was exhibited in the ulcer group and EEVS or omeprazole offered significant (P < 0.05) protection against mucosal ulceration. Histologically, the gastric submucosal layer showed remarkable decrease in edema and leucocytes infiltration compared with ulcer group.

CONCLUSIONThe study suggests that EEVS offered a protective action against aspirin plus pylorus ligation-induced gastric ulcers in Wistar rats. The protective effect might be mediated via antisecretory, cytoprotective and antioxidative mechanisms.

Animals ; Anti-Ulcer Agents ; pharmacology ; therapeutic use ; Antioxidants ; pharmacology ; therapeutic use ; Aspirin ; Edema ; Gastric Mucosa ; drug effects ; metabolism ; pathology ; Gastrointestinal Agents ; pharmacology ; therapeutic use ; Glutathione Peroxidase ; metabolism ; Hydrogen-Ion Concentration ; Leukocytes ; Male ; Malondialdehyde ; metabolism ; Mucus ; metabolism ; Nuts ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Rats, Wistar ; Severity of Illness Index ; Stomach Ulcer ; chemically induced ; drug therapy ; metabolism ; prevention & control ; Superoxide Dismutase ; metabolism ; Vigna

PURPOSE: In the gastric mucosa of Helicobacter pylori (H. pylori)-infected patients with gastritis or adenocarcinoma, proliferation of gastric epithelial cells is increased. Hyperproliferation is related to induction of oncogenes, such as β-catenin and c-myc. Even though transcription factors NF-κB and AP-1 are activated in H. pylori-infected cells, whether NF-κB or AP-1 regulates the expression of β-catenein or c-myc in H. pylori-infected cells has not been clarified. The present study was undertaken to investigate whether H. pylori-induced activation of NF-κB and AP-1 mediates the expression of oncogenes and hyperproliferation of gastric epithelial cells. MATERIALS AND METHODS: Gastric epithelial AGS cells were transiently transfected with mutant genes for IκBα (MAD3) and c-Jun (TAM67) or treated with a specific NF-κB inhibitor caffeic acid phenethyl ester (CAPE) or a selective AP-1 inhibitor SR-11302 to suppress activation of NF-κB or AP-1, respecively. As reference cells, the control vector pcDNA was transfected to the cells. Wild-type cells or transfected cells were cultured with or without H. pylori. RESULTS: H. pylori induced activation of NF-κB and AP-1, cell proliferation, and expression of oncogenes (β-catenein, c-myc) in AGS cells, which was inhibited by transfection of MAD3 and TAM67. Wild-type cells and the cells transfected with pcDNA showed similar activities of NF-κB and AP-1, proliferation, and oncogene expression regardless of treatment with H. pylori. Both CAPE and SR-11302 inhibited cell proliferation and expression of oncogenes in H. pylori-infected cells. CONCLUSION: H. pylori-induced activation of NF-κB and AP-1 regulates transcription of oncogenes and mediates hyperproliferation in gastric epithelial cells.
Blotting, Western ; Caffeic Acids ; Cell Line, Tumor ; Cell Proliferation ; DNA, Bacterial/analysis/genetics ; DNA-Binding Proteins/*metabolism ; Epithelial Cells/*metabolism ; Gastric Mucosa/*metabolism/pathology ; Gastritis/pathology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/metabolism/pathology/physiopathology ; Helicobacter pylori/pathogenicity/physiology ; Humans ; NF-kappa B/antagonists & inhibitors/*biosynthesis/metabolism ; Peptide Fragments ; Phenylethyl Alcohol/analogs & derivatives ; Proto-Oncogene Proteins c-jun ; Repressor Proteins ; Transcription Factor AP-1/*biosynthesis ; Transcription Factors/*metabolism ; beta Catenin/*metabolism

Intraportal transplantation of islets is no longer considered to be an ideal procedure and finding the extrahepatic alternative site is becoming a subject of high priority. Herein, in this study, we would introduce our initial outcomes of using gastric submucosa (GS) and liver as sites of islet autotransplantation in pancreatectomized diabetic Beagles. Total pancreatectomy was performed in Beagles and then their own islets extracted from the excised pancreas were transplanted into GS (GS group, n=8) or intrahepatic via portal vein (PV group, n=5). Forty-eight hours post transplantation, graft containing tissue harvested from the recipients revealed the presence of insulin-positive cells. All recipients in GS group achieved euglycemia within 1 day, but returned to a diabetic state at 6 to 8 days post-transplantation (mean survival time, 7.16±0.69 days). However, all of the animals kept normoglycemic until 85 to 155 days post-transplantation in PV group (mean survival time, 120±28.58 days; P<0.01 vs. GS group). The results of intravenous glucose tolerance test (IVGTT) confirmed that the marked improvement in glycometabolism was obtained in intrahepatic islet autotransplantation. Thus, our findings indicate that the liver is still superior to the GS as the site of islet transplantation, at least in our islet autotransplant model in pancreatectomized diabetic Beagles.
Animals ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; therapy ; Dogs ; Gastric Mucosa ; metabolism ; transplantation ; Glucose ; metabolism ; Glucose Tolerance Test ; Graft Survival ; Humans ; Insulin ; metabolism ; Islets of Langerhans Transplantation ; Liver ; pathology ; Liver Transplantation ; Transplantation, Autologous

OBJECTIVETo study the effects of Weipixiao (胃痞消, WPX) on Wnt pathway-associated proteins in gastric mucosal epithelial cells from rats with gastric precancerous lesions (GPL).

METHODSSprague Dawley rats were randomly divided into control, model, vitacoenzyme (0.2 g·kg(-1)·day(-1)), WPX high-dose (H-WPX, 15 g·kg(-1)·day(-1)), WPX medium-dose (M-WPX, 7.5 g·kg(-1)·day(-1)) and WPX low-dose (L-WPX, 3.75 g·kg(-1)·day(-1)) groups. After successfully establishing the GPL model, the rats were consecutively administered WPX or vitacoenzyme by gastrogavage for 10 weeks. Differential expression of Leucine-rich repeat-containing G-proteincoupled receptor 5 (Lgr5), matrix metalloproteinase-7 (MMP-7), Wnt1, Wnt3a, and β-catenin in gastric mucosal epithelial cells in all groups were immunohistochemically detected, and the images were taken and analyzed semiquantitatively by image pro plus 6.0 software.

RESULTSGastric epithelium in the model group showed significantly higher expression levels of Lgr5, MMP-7, Wnt1, Wnt3a and β-catenin than those of the control group(P<0.01). Interestingly, we also observed Lgr5+ cells, which generally located at the base of the gastric glandular unit, migrated to the luminal side of gastric epithelium with GPL. The expression levels of Lgr5, MMP-7, Wnt1, and β-catenin were all down-regulated in the L-WPX group as compared with those of both model and vitacoenzyme groups (P<0.05). A similar, but nonsignificant down-regulation in expression level of Wnt3a was noted in all WPX groups (P>0.05).

CONCLUSIONOur findings suggested that the therapeutic mechanisms of WPX in treating GPL might be related with its inhibitory effects on the expressions of Lgr5, MMP-7, Wnt1, β-catenin and the aberrant activation of Wnt/β-catenin pathway.

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Gastric Mucosa ; pathology ; Immunohistochemistry ; Male ; Matrix Metalloproteinase 7 ; metabolism ; Precancerous Conditions ; drug therapy ; pathology ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; metabolism ; Staining and Labeling ; Stomach Neoplasms ; drug therapy ; pathology ; Wnt Proteins ; metabolism ; Wnt Signaling Pathway ; drug effects ; beta Catenin ; metabolism

OBJECTIVETo understand the junction protein expression of gastric mucosa including occlusal proteins (occludin), closed protein-4 (claudin-4), zonula occluden-1(ZO-1), epithelial cadherin (E-cadherin), and β ring protein (β-catenin) and the clinical significance in children with Helicobacter pylori (Hp) infection.

METHODSeventy patients in whom gastric endoscopy was performed because of nausea, vomiting, abdominal pain, bloating, acid reflux, melena, and other gastrointestinal symptoms were enrolled in this study from Dec. 2010 to Apr. 2013 in our hospital. Informed consent was signed by their parents, and the study was in accordance with the principles of medical ethics. Hp positivity was confirmed if both respiratory urea test (RUT) and Hp were positive by gastric mucosal pathology. Gastric mucosal samples from 70 patients were enrolled in this study, 23 of them were Hp negative, 47 of them were Hp positive (24 cases without peptic ulcer, 23 cases with peptic ulcer). The mRNA levels and protein expression of tight junction protein of gastric mucosa were measured by RT-PCR and Western blot respectively. The location and semi quantitative content of E-cadherin and β-catenin in gastric mucosa were detected by immunohistochemical staining method.

RESULTThe mRNA level of E-cadherin, β-catenin, ZO-1 in the Hp positive group regardless of peptic ulcer was significantly lower than that in the Hp negative group. Hp positive without peptic ulcer group were 0.0008, 0.0040, 0.0014, respectively; Hp positive with peptic ulcer group were 0.0010, 0.0090, 0.0013, respectively; Hp negative group were 0.0137, 0.0423, 0.0198, respectively (F values were 36.956, 39.893, 38.962, respectively, all P<0.05). The expression of claudin-4 mRNA in Hp positive group with peptic ulcer increased significantly, the difference among Hp positive group with peptic ulcer, Hp positive group without peptic ulcer and Hp negative group was statistically significant (0.1438 vs. 0.0926 vs. 0.0789) (F value was 11.964, P<0.05), while the difference of occludin mRNA levels among the three groups was not statistically significant.Immunohistochemistry results showed that the score of E-cadherin, β-catenin positive cell in the Hp positive patients were also significantly lower than that in the Hp negative group (t values were 3.981 and 2.340, all P<0.05, respectively). Western blot results showed that the protein levels of β-catenin in Hp positive group with peptic ulcer were significantly lower than that in Hp negative group, while the protein levels of E-cadherin in Hp positive patients regardless of peptic ulcer were decreased significantly in Hp negative group.

CONCLUSIONOur results revealed that the tight junction protein E-cadherin, β-catenin, ZO-1 expression of gastric mucosa were decreased in children with Hp infection, while claudin-4 expression was increased in Hp positive patients with peptic ulcer, suggesting that damage to gastric epithelial barrier function may be the main pathogenesis of Hp associated gastric diseases in children.

Blotting, Western ; Cadherins ; metabolism ; Child ; Claudin-4 ; metabolism ; Gastric Mucosa ; metabolism ; pathology ; Helicobacter Infections ; metabolism ; Helicobacter pylori ; Humans ; Immunohistochemistry ; Occludin ; metabolism ; Peptic Ulcer ; metabolism ; microbiology ; RNA, Messenger ; Tight Junction Proteins ; metabolism ; Tight Junctions ; metabolism ; Zonula Occludens-1 Protein ; metabolism ; beta Catenin ; metabolism

OBJECTIVETo investigate the expression of osteopontin (OPN) splice variant mRNA, including the three isoforms OPN-A, OPN-B, and OPN-C, to explore its correlation with clinicopathologic features in gastric cancer, and to elucidate their role in tumor invasion and distant metastasis of gastric cancer.

METHODSThe expression of OPN-A, OPN-B and OPN-C mRNA were detected by real-time reverse transcriptase-polymerase chain reaction in 66 gastric cancer tissues. The relationship between the expression of OPN-A, OPN-B and OPN-C mRNA and clinicopathologic features of gastric cancer was analyzed.

RESULTSThe expression of OPN-C mRNA in the gastric cancer tissue was 3.21-fold higher than that in peritumoral mucosal tissue, showing a significant difference between them (P < 0.001). OPN-C mRNA expression was correlated with the depth of tumor invasion, tumor diameter, lymph node meatastasis, distant meatastasis and had no correlation with differentiation grades. The low expression of OPN-C mRNA was correlated with long survival benefit (P = 0.03). The expression of OPN-A and OPN-B mRNA had no significant relationship with clinicopathologic features of gastric cancer.

CONCLUSIONSOne of the isoform of osteopontin (OPN) OPN-C mRNA is overexpressed in gastric cancer. The overexpression of OPN-C mRNA may reflect the progression and is associated with the prognosis of gastric cancer. OPN-C mRNA may have value as a prognostic biomarker in gastric cancer. However, the expression of OPN-A and OPN-B are not correlated with the progression and metastasis of gastric cancer.

Disease Progression ; Gastric Mucosa ; metabolism ; Humans ; Lymph Nodes ; Lymphatic Metastasis ; Neoplasm Invasiveness ; Neoplasm Proteins ; genetics ; Osteopontin ; genetics ; Prognosis ; Protein Isoforms ; genetics ; RNA, Messenger ; metabolism ; Real-Time Polymerase Chain Reaction ; Stomach Neoplasms ; genetics ; mortality ; pathology

OBJECTIVETo investigate the effect of Rhizoma Atractylodis extract (ERA) in protecting gastric mucosa and modulating gastrointestinal immune function of a rat model of spleen deficiency syndrome and elucidate the mechanism by which ERA improves spleen deficiency syndrome.

METHODSMale rats were fed with Xiaochengqi decoction and subjected to irregular feeding to induce spleen deficiency syndrome. The established models were randomized into model group, high-, moderate- and low-dose ERA groups, and domperidone group. After corresponding treatment for 30 days, the content of IgA in the intestinal lavage fluid, serum IgG, and the indices of the spleen and thymus were determined. The pathological changes in the gastric mucosa was observed with HE staining, gastric mucosal blood flow was evaluated with laser Doppler rheometry, and the expression of TFF1 in the gastric mucosa and TLR4 expression in the colon tissue were detected with immunohistochemistry.

RESULTSThe rat models of spleen deficiency syndrome showed obvious abnormalities in gastric mucosal morphology, blood flow and immunological indexes. Compared with the model rats, the rats receiving ERA treatment as different doses all showed significant improvements in gastric mucosal morphology, blood flow volume, gastric mucosa trefoil factor 1 (TFF1) expression, intestinal lavage fluid IgA content, serum IgG content, indices of the spleen and thymus, and TLR4 expression in the colon TLR4 (P<0.05 or P<0.01).

CONCLUSIONERA can inhibit gastric mucosal damage, protect and repair the damaged mucosal tissues, and improve the immune function of in rats with spleen deficiency.

Animals ; Atractylodes ; chemistry ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Gastric Mucosa ; drug effects ; pathology ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; blood ; Immunohistochemistry ; Male ; Peptides ; metabolism ; Rats ; Rhizome ; chemistry ; Spleen ; physiopathology ; Trefoil Factor-2

OBJECTIVEThe aim of this study was to investigate the clinicopathological features of different histological types of primary gastric neuroendocrine neoplasms (including the esophagogastric junction), and to analyze the characteristics and difficulties in diagnosis of all the subtypes of this disease.

METHODS75 cases of primary gastric neuroendocrine neoplasms (including the esophagogastric junction) were included in this study. The expressions of several markers including somatostatin, synaptophysin, chromogranin A, CD56, S-100, neuron-specific enolase and CD57 were assayed in all the specimens by immunohistochemical staining, and their significance in the diagnosis and prognosis of gastric neuroendocrine neoplasms were assessed. In addition, the relationship between various clinical parameters such as tumor location, histological types, depth of invasion and metastasis was also analyzed.

RESULTSThe incidence of gastric neuroendocrine neoplasms accounted for 1.5% of gastric cancer in the same period, and the proportion of each subtype was 53.3% (40/75) in G3, 29.3% (22/75) in MANEC, 16.0% in G1(12/75), and 1.3% (1/75) in G2, respectively. 41.7% (5/12) of the G1 showed multifocal lesions, accompanyied with neuroendocrine cell hyperplasia in the gastric mucosa. 54.67% (41/75) of the NEN located in the esophagogastric junction. The lymph node metastasis of MANEC is unique. The coincidence rate in diagnosis of preoperative biopsies and postoperative specimen was 75.0% (9/12) in G1, 72.7% (16/22) in MANEC, and 25.0% (10/40) in G3, respectively.

CONCLUSIONSGastric neuroendocrine neoplasms occur mainly in the esophagogastric junction, and most of them were highly malignant. The coincidence rate of preoperative and postoperative pathological diagnosis for primary gastric neuroendocrine neoplasms is low. Therefore, it should be very cautious when diagnosis of this disease is made in a preoperative biopsy.

Chromogranin A ; metabolism ; Esophagogastric Junction ; metabolism ; Gastric Mucosa ; metabolism ; pathology ; Humans ; Lymphatic Metastasis ; pathology ; Neuroendocrine Tumors ; pathology ; Phosphopyruvate Hydratase ; metabolism ; Prognosis ; Stomach Neoplasms ; pathology ; Synaptophysin ; metabolism