Mouse Gastric Tissue Research Articles

Inhibitory effect of medicinal plants from Cameroon on the growth and adhesion of Helicobacter pylori

IntroductionPlants in the Cameroon Pharmacopoeia are used by the population as decoctions, infusions and are macerated to relieve digestive and gastric disorders. The aim of this study was to screen for the anti-Helicobacter pylori and anti-adhesion activities of various plant extracts from Cameroon. MethodsMedicinal plants used for the treatment and stomach pains and digestive disorders were identified and collected in an ethnopharmacological survey in Cameroon. Dried plant material were used to prepare crude extracts and tested against Helicobacter pylori strain P12 . The minimal inhibitory concentration (MIC) of plant extract was determined by broth micro dilution and agar diffusion methods. The anti-adhesion was determined by adhesion of Fluorescein-isothiocyanate (FITC) labelled Helicobacter pylori to sections of mouse gastric tissue and expression of adhesion gene in response to the plant extract treatment using RT-PCR and western blotting. Results were analyzed statistically by the Bonferroni’s post hoc test. ResultsAll the plant extracts demonstrated anti-Helicobacter pylori activity with MIC values ranging from 0.125 to 100 mg/ml. Spathodea campanulata and Nicotina tabacum showed the highest anti-Helicobacter pylori activity on H. pylori P12 strain. The lowest MIC recorded by Spathodea campanulata and Nicotina tabacum were 0.125 and 1 mg/ml respectively. Seventeen plant extracts reduced H. pylori adhesion to the mouse tissue stomach. In addition, plant extracts decreased the expression of blood group antigen-binding adhesion BabA and H. pylori outer membrane protein HopZ. ConclusionSpathodea campanulata and Nicotina tabacum may be useful in the development of new drugs for the treatment of H. pylori infection. They represent promising natural sources to be used in pharmacology.

Preventive Effect of Anji White Tea Flavonoids on Alcohol-Induced Gastric Injury through Their Antioxidant Effects in Kunming Mice.

Anji white tea (Camellia sinensis) is a traditional Chinese tea beverage, which is classified as green tea and contains an abundant amount of flavonoids. In this study, the preventive effect of Anji white tea flavonoids (AJWTFs) on ethanol/hydrochloric acid-induced gastric injury in mice was evaluated. The serum and gastric tissues of mice were analyzed using a biochemical kit and by quantitative polymerase chain reaction (qPCR). Observation of the appearance of the stomach indicated that AJWTFs could effectively reduce the area of gastric injury caused by ethanol/hydrochloric acid, and the inhibition rate of AJWTF on gastric injury increased with an increase in AJWTF concentration. The Anji white tea flavonoids could also reduce the volume and pH of gastric juice in mice with gastric injury. Biochemical results showed that AJWTFs could increase the superoxide dismutase (SOD) and glutathione (GSH) activities, as well as decrease the malondialdehyde (MDA) level, in the serum and liver of mice with gastric injury. Pathological observation confirmed that AJWTFs could inhibit the tissue damage caused by ethanol/hydrochloric acid in the stomach of mice. Further qPCR experiments also showed that AJWTFs could inhibit the decreases in neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), copper/zinc superoxide dismutase (Cu/Zn–SOD), manganese superoxide dismutase (Mn–SOD), catalase (CAT), and the increase in inducible nitric oxide synthase (iNOS) expression in the gastric tissue of mice caused by gastric injury. As observed, AJWTFs exerted a good preventive effect on alcohol-induced gastric injury in mice induced by ethanol/hydrochloric acid, and the effect is close to that of ranitidine. Anji white tea flavonoids present good antioxidant effect, which allows them to effectively prevent alcoholic gastric injury and be used as biologically active substances with a broad range of applications.

Preventive Effect of Blueberry Extract on Liver Injury Induced by Carbon Tetrachloride in Mice.

The blueberry is a common fruit that is rich in nutritional value and polyphenol substances. In this study, the blueberry polyphenol content in extract was analysed by spectrophotometry. The results showed that the blueberry polyphenol content in the extract reached 52.7%. A mouse model of liver injury induced by carbon tetrachloride (CCl4) was established to study the preventive effect of blueberry extract (BE) on liver injury in mice and the experimental animals were examined using biochemical and molecular biological methods. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are important clinical liver function indicators; the changes of triglyceride (TG) and total cholesterol (TC) are observed after liver injury; interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) are important inflammatory indexes; superoxide dismutase (SOD) activity and thiobarbituric acid reactive substances (TBARS) are important changes of oxidative stress indexes. The in vivo animal experiment results showed that BE decreased the liver index of mice with liver injury, BE could reduce the AST, ALT, TG and TC levels and also could reduce the serum cytokine IL-6, TNF-α and IFN-γ levels in mice with liver injury. Moreover, BE increased the SOD activity and decreased the TBARS level in the gastric tissues of mice with liver injury. After treatment with the highest concentration of BP in liver injury mice, these levels returned close to those obtained after treatment with the standard drug of silymarin. Detection of messenger RNA (mRNA) in liver tissue showed that BE upregulated the Cu/Zn-SOD, Mn-SOD and chloramphenicol acetyltransferase (CAT) expression levels and downregulated cyclooxygenase (COX)-2 expression. The effect of BE on mice with liver injury was positively correlated with the BE concentration and was similar to that of silymarin, which is a drug for liver injury, suggesting that BE had a good preventive effect on liver injury. Thus, BE rich in polyphenols is a bioactive substance with value for development and utilization.

A novel role for the extracellular matrix glycoprotein-Tenascin-X in gastric function.

Key points Tenascin X (TNX) functions in the extracellular matrix of skin and joints where it maintains correct intercellular connections and tissue architectureTNX is associated exclusively with vagal‐afferent endings and some myenteric neurones in mouse and human stomach, respectively.TNX‐deficient mice have accelerated gastric emptying and hypersensitivity of gastric vagal mechanoreceptors that can be normalized by an inhibitor of vagal‐afferent sensitivity.Cultured nodose ganglion neurones showed no changes in response to capsaicin, cholecystokinin and potassium chloride in TNX‐deficient mice.TNX‐deficient patients have upper gastric dysfunction consistent with those in a mouse model. Our translational studies suggest that abnormal gastric sensory function may explain the upper gut symptoms present in TNX deficient patients, thus making it important to study gastric physiology.TNX deficiency should be evaluated routinely in patients with connective tissue abnormalities, which will enable a better understanding of its role and allow targeted treatment. For example, inhibitors of vagal afferents‐baclofen could be beneficial in patients. These hypotheses need confirmation via targeted clinical trials. Tenascin‐X (TNX) is a glycoprotein that regulates tissue structure via anti‐adhesive interactions with collagen in the extracellular matrix. TNX deficiency causes a phenotype similar to hypermobility Ehlers–Danlos syndrome involving joint hypermobility, skin hyperelasticity, pain and gastrointestinal dysfunction. Previously, we have shown that TNX is required for neural control of the bowel by a specific subtype of mainly cholinergic enteric neurones and regulates sprouting and sensitivity of nociceptive sensory endings in mouse colon. These findings correlate with symptoms shown by TNX‐deficient patients and mice. We aimed to identify whether TNX is similarly present in neural structures found in mouse and human gastric tissue. We then determined whether TNX has a functional role, specifically in gastric motor and sensory function and nodose ganglia neurones. We report that TNX was present in calretinin‐immunoreactive extrinsic nerve endings in mouse and human stomach. TNX deficient mice had accelerated gastric emptying and markedly increased vagal afferent responses to gastric distension that could be rescued with GABAB receptor agonist. There were no changes in nodose ganglia excitability in TNX deficient mice, suggesting that vagal afferent responses are probably the result of altered peripheral mechanosensitivity. In TNXB‐deficient patients, significantly greater symptoms of reflux, indigestion and abdominal pain were reported. In the present study, we report the first role for TNX in gastric function. Further studies are required in TNX deficient patients to determine whether symptoms can be relieved using GABAB agonists.

Integrated Analysis of Mouse and Human Gastric Neoplasms Identifies Conserved microRNA Networks in Gastric Carcinogenesis

microRNAs (miRNAs) are small noncoding RNAs that bind to the 3' untranslated regions of mRNAs to promote their degradation or block their translation. Mice with disruption of the trefoil factor 1 gene (Tff1) develop gastric neoplasms. We studied these mice to identify conserved miRNA networks involved in gastric carcinogenesis. We performed next-generation miRNA sequencing analysis of normal gastric tissues (based on histology) from patients without evidence of gastric neoplasm (n= 64) and from TFF1-knockout mice (n= 22). We validated our findings using 270 normal gastric tissues (including 61 samples from patients without evidence of neoplastic lesions) and 234 gastric tumor tissues from 3 separate cohorts of patients and from mice. We performed molecular and functional assays using cell lines (MKN28, MKN45, STKM2, and AGS cells), gastric organoids, and mice with xenograft tumors. We identified 117 miRNAs that were significantly deregulated in mouse and human gastric tumor tissues compared with nontumor tissues. We validated changes in levels of 6 miRNAs by quantitative real-time polymerase chain reaction analyses of neoplastic gastric tissues from mice (n= 39) and 3 independent patient cohorts (n= 332 patients total). We found levels of MIR135B-5p, MIR196B-5p, and MIR92A-5p to be increased in tumor tissues, whereas levels of MIR143-3p, MIR204-5p, and MIR133-3p were decreased in tumor tissues. Levels of MIR143-3p were reduced not only in gastric cancer tissues but also in normal tissues adjacent to tumors in humans and low-grade dysplasia in mice. Transgenic expression of MIR143-3p in gastric cancer cell lines reduced their proliferation and restored their sensitivity to cisplatin. AGS cells with stable transgenic expression of MIR143-3p grew more slowly as xenograft tumors in mice thancontrol AGS cells; tumor growth from AGS cells that expressed MIR143-3p, but not control cells, was sensitive to cisplatin. We identified and validated bromodomain containing 2 (BRD2) as a direct target of MIR143-3p; increased levels of BRD2 in gastric tumors was associated with shorter survival times for patients. In an analysis of miRNA profiles of gastric tumors from mice and human patients, we identified a conserved signature associated with the early stages of gastric tumorigenesis. Strategies to restore MIR143-3p or inhibit BRD2 might be developed for treatment of gastric cancer.

Mouse Models Of Helicobacter Infection And Gastric Pathologies.

Helicobacter pylori is a gastric pathogen that is present in half of the global population and is a significant cause of morbidity and mortality in humans. Several mouse models of gastric Helicobacter infection have been developed to study the molecular and cellular mechanisms whereby H. pylori bacteria colonize the stomach of human hosts and cause disease. Herein, we describe protocols to: 1) prepare bacterial suspensions for the in vivo infection of mice via intragastric gavage; 2) determine bacterial colonization levels in mouse gastric tissues, by polymerase chain reaction (PCR) and viable counting; and 3) assess pathological changes, by histology. To establish Helicobacter infection in mice, specific pathogen-free (SPF) animals are first inoculated with suspensions (containing ≥105 colony-forming units, CFUs) of mouse-colonizing strains of either Helicobacter pylori or other gastric Helicobacter spp. from animals, such as Helicobacter felis. At the appropriate time-points post-infection, stomachs are excised and dissected sagittally into two equal tissue fragments, each comprising the antrum and body regions. One of these fragments is then used for either viable counting or DNA extraction, while the other is subjected to histological processing. Bacterial colonization and histopathological changes in the stomach may be assessed routinely in gastric tissue sections stained with Warthin-Starry, Giemsa or Haematoxylin and Eosin (H&E) stains, as appropriate. Additional immunological analyses may also be undertaken by immunohistochemistry or immunofluorescence on mouse gastric tissue sections. The protocols described below are specifically designed to enable the assessment in mice of gastric pathologies resembling those in human-related H. pylori diseases, including inflammation, gland atrophy and lymphoid follicle formation. The inoculum preparation and intragastric gavage protocols may also be adapted to study the pathogenesis of other enteric human pathogens that colonize mice, such as Salmonella Typhimurium or Citrobacter rodentium.

Hedgehog signaling induces PDL‐1 expression and subsequently inactivates effector T cell function and promotes gastric cancer cell proliferation

BackgroundHedgehog (Hh) signaling plays a crucial role in tumor growth and chemoresistance in a variety of tumors including gastric cancer. Tumor cells often express elevated programmed cell death 1 (PD‐L1) that interacts with PD‐1 on CD8+ cytotoxic T lymphocytes (CTLs). This interaction inhibits CTL effector function, leading to immune evasion and cancer cell proliferation. Regulation of PD‐L1 may be a promising therapeutic strategy, but the regulatory mechanism remains unclear in gastric cancer.HypothesisHh signaling induces PDL‐1 expression and subsequently inactivates effector T cell function and promotes gastric cancer cell proliferation.MethodsMouse‐derived gastric cancer organoids were generated from a triple‐transgenic model engineered to express an activated GLI2 allele, GLI2A, in Lgr5‐expressing stem cells when treated with doxycycline (iLgr5;GLI2A mTGOs). Organoids were also derived from normal mouse gastric tissue (mGOs). Conditioned media was collected from mTGOs (mTGOCM) and mGOs (mGOCM). Bone marrow‐derived dendritic cells (DCs) were pulsed with either mGOCM or mTGOCM for 24 hrs and co‐cultured with CTLs for 48 hrs. Pulsed DCs and CTLs were then co‐cultured with either mGOs or mTGOs for 24 hrs in presence or absence of PD‐L1 inhibitor (PDL‐1I). Apoptosis and cell proliferation were measured using TUNEL or Edu Imaging Assay Kits respectively. mTGOs were treated with GANT61. PD‐L1 expression and cell proliferation were measured after 48 hrs. iLgr5;GLI2A mice were injected with either Hh inhibitor GANT61 or phosphate buffered saline for 20 days and stomach tissues were immunostained for PD‐L1 and metaplastic markers CD44v9 and lectin Griffonia simplicifolia (GSII). Human‐derived gastric cancer organoids (huTGO) were derived from resected tumors and analyzed for Gli2 and PD‐L1 expression. HuTGOs were treated for 48 hours with gastric cancer chemotherapeutic agents (Epirubicin, Oxaliplatin, and 5‐FU) in presence or absence of GANT61 and organoid proliferation measured by MTS proliferation assay.Results Increased Gli‐2 correlates with the elevated PD‐L1 expression: ILgr5;GLI2A mice developed rapid gastric adenocarcinoma within the antrum. Organoids derived from these tumors (mTGOs) expressed Gli2 that correlated with elevated PD‐L1 expression when compared to mGOs. Inhibition of PD‐L1 in mTGO/immune cell co‐cultures induces organoid death: CTLs co‐cultured with DCs pulsed with mTGOCM had increased expression of PD‐1, IFNg, and IL‐2, compared to co‐cultures using unpulsed DCs or DCs pulsed with mGOCM. Live time‐lapse microscopy revealed migration of DCs and CTLs toward mTGOs in co‐culture. Pulsed DC/CTL/mTGO co‐cultures revealed no apoptosis or organoid death. Interestingly, when pulsed DC/CTL/mTGO co‐cultures were treated with PDL‐1I, there was induced organoid apoptosis and death. Hedgehog signaling regulates PD‐L1 expression and organoid proliferation: Hh inhibitor, GANT‐61 significantly reduced PD‐L1 expression and tumor cell proliferation both in vitro in mTGOs and in vivo in ILgr5;GLI2A mice. In vivo, GANT61 treatment resulted in decreased PD‐L1 expression that correlated with loss of tumor growth and decreased metaplasia. Inhibition of Hedgehog signaling sensitizes organoids to chemotherapy: Chemotherapy‐induced cell death in Gli2/PD‐L1+ve huTGOs pretreated with GANT61. ConclusionHh signaling plays a role as a regulator of PDL‐1 expression in gastric cancer cells to promote tumor growth.Support or Funding Information1RO1DK083402 (Zavros RO1)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of caspase-1 inhibitor VX765 on cold-restraint stress-induced acute gastric ulcer in mice

Objective: To investigate the protective effects of caspase-1 inhibitor VX765 on gastric mucosa of mice with cold-restraint stress-induced acute gastric ulcer. Methods: Twenty-four specific pathogen free male C57BL/6J mice were divided into normal control group (NC), cold restrain group (CR), VX765 pre-treatment+ cold restrain group (VCR), and rabeprazole pre-treatment+ cold restrain group (RCR) according to the random number table, with 6 mice in each group. Mice in group NC were injected intraperitoneally with solution of 10 mL/kg dimethylsulfoxide (DMSO) and phosphate buffer solution (PBS). Mice in group CR were inflicted with acute gastric ulcer induced by cold-restraint stress 30 minutes after intraperitoneal injection of solution of DMSO and PBS. Mice in groups VCR and RCR were inflicted with acute gastric ulcer as above 30 minutes after intraperitoneal injection of solution of DMSO and PBS with dose of 12.5 μmol/kg containing 10 mg VX765 and 40 mg/kg containing 20 mg rabeprazole, respectively. Four hour after cold-restraint stress, serum content of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6)was determined by enzyme-linked immunosorbent assay. Gross condition of gastric tissue was observed. Ulcer index was evaluated. Pathological change of gastric tissue was observed with HE staining. The relative expression of IL-1β, IL-18, and cleaved-caspase-1 in gastric tissue were detected by Western blotting. Mice in group NC were detected as above at the same time point. Data were processed with one-way analysis of variance and Bonferroni test. Results: The serum content of TNF-α and IL-6 and the relative expression of cleaved-caspase-1, IL-1β, and IL-18 in gastric tissue of mice in group NC were significantly lower than those in group CR (with P values below 0.01). The content of the above-mentioned inflammatory indexes in serum and gastric tissue of mice in group VCR was significantly lower than that in group CR (with P values below 0.01). There were no statistically significant differences in content of the above-mentioned inflammatory indexes in serum and gastric tissue of mice between groups RCR and CR (with P values above 0.05). The content of the above-mentioned inflammatory indexes in serum and gastric tissue of mice in group VCR was significantly lower than that in group RCR (with P values below 0.01). Surface of gastric mucosa was smooth and morphology of mucosal cells was normal with clear structure of mice in group NC. Multiple hemorrhage of gastric mucosa, disorderly arrangement of mucosal cells, and large number of inflammatory cell infiltration around necrotic tissue were observed in mice of group CR. Decreased number of gastric mucosa bleeding, intact mucosal structure, and small amount of inflammatory cell infiltration around necrotic tissue were observed in mice of groups VCR and RCR. The ulcer indexes of mice in groups NC, CR, VCR, and RCR were 0, 18.7±1.1, 6.3±1.5, and 8.2±1.3, respectively. The ulcer index of mice in group NC was significantly lower than that in the other 3 groups (with P values below 0.05). The ulcer indexes of mice in groups VCR and RCR were close (P>0.05), which were significantly lower than ulcer index of mice in group CR (with P values below 0.05). Conclusions: VX765 can effectively inhibit the activation of caspase-1, reduce production of inflammatory factor, and alleviate inflammatory response, which have protective effects on gastric mucosa of mice with cold-restraint stress-induced acute gastric ulcer.

Gastroprotective effect of aucubin against ethanol-induced gastric mucosal injury in mice

AimsAucubin, an iridoid glycoside, was isolated from seeds of Eucommia ulmoides Oliver. This study was aimed to evaluate the protective effect of aucubin against ethanol-induced gastric mucosal injury in mice. Materials and methodsMice were orally administrated with aucubin (20, 40 and 80mg/kg) for 3 consecutive days. On the 3rd day, the mice of gastric mucosal injury were induced with 70% ethanol after the last administration of aucubin. Gastric tissue of mice were submitted for evaluating the severity of gastric mucosal injury. The protective effect of aucubin was evaluated by the gastric ulcer index and histological examinations and determining the levels of inflammatory cytokines, oxidative stress and some gastric mucosal protection factors. Key findingsProphylactic oral administration of aucubin decreased gastric ulcer indexes and histological scores. A significant decrease of myeloperoxidase (MPO) activity and the levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were observed in aucubin administrated groups. In addition, mice administrated with aucubin increased glutathione (GSH) and heat shock protein-70 (HSP-70) levels and superoxide dismutase (SOD) activity, as well as normalized the levels of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and cyclooxygenase-1 (COX-1) in gastric tissue of mice. SignificanceThe findings of this study demonstrated that aucubin shows protective effect against ethanol-induced acute gastric mucosal injury through its anti-inflammatory and anti-oxidant effects. Furthermore, aucubin enhanced gastric mucosal protection by up-regulation of HSP-70 level and normalization of EGF, VEGF and COX-1 levels.

Abstract 4339: Single cell RNA sequencing dissects cellular growth factor dependencies and oncogenic driver effects in an organoid model of gastric cancer

Abstract Gastric cancer is a lethal malignancy with few therapeutic options. Gastric tumors rely on complex intercellular signaling “crosstalk” that enables tumor development, metastasis, and therapeutic resistance. To recapitulate the intercellular communications among various cell populations that exist in vivo, we are using a three-dimensional culture system to grow and manipulate mouse gastric tissue in vitro, otherwise referred to as organoids. Importantly, this organoid model contains epithelium with its endogenous mesenchymal niche and does not require exogenous Wnt stimulation. To systematically analyze the distinct cellular lineages and their interactions, we applied a massively-scaled single cell RNA-Seq platform to sequence thousands of individual cells from organoid cultures. With PCA and t-SNE analysis of the high-dimensional data generated from single cell RNA-seq, we characterized two major cell types, i.e. epithelial and mesenchymal cells. Leverage the information from single cell transcriptome profiles, we identified specific niche factors of the Wnt signaling pathways that are activated in different stomach cell lineages. These results suggest that the mesenchymal cell populations provide a potential source of the R-spondin, a Wnt agonist, that sustains the growth of epithelium. Furthermore, we compared cell populations from Cdh1-/-/Trp53-/- and Trp53-/-organoids, and characterized changes on the transcriptome profiles due to the loss of Cdh1, an early oncogenic event in diffuse gastric cancer development. Overall, using organoid model and high-throughput single cell RNA-Seq provides a novel approach to study early tumor transformation and critical cancer-stroma interactions. Citation Format: Jiamin Chen, Noemi Andor, Susan M. Grimes, Billy Lau, Hanlee P. Ji. Single cell RNA sequencing dissects cellular growth factor dependencies and oncogenic driver effects in an organoid model of gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4339. doi:10.1158/1538-7445.AM2017-4339

Stem Cells Antigen-1 Enriches for a Cancer Stem Cell-Like Subpopulation in Mouse Gastric Cancer.

There is a strong need to identify markers to enrich gastric cancer stem cells (CSCs). However, CSC enrichment markers for mouse gastric cancers have not yet been determined. In our previous study, we generated primary mouse gastric cancer cell line NCC-S1 (S1) established from a Villin-cre;Smad4(F/F) ;Trp53(F/F) ;Cdh1(F/wt) mouse and its metastatic variant cell line NCC-S1M (S1M). Interestingly, S1M cells exhibited CSC-like features, such as increased tumorigenic potential and chemoresistance. By comparing gene expression profiles between S1 and S1M cells, we identified Stem Cells Antigen-1 (Sca-1) as a cell surface marker, which was mostly upregulated in S1M. Sca-1 was upregulated in tumorspheres from S1 cells or after cisplatin treatment in S1 cells. Immunofluorescence (IF) analysis showed that approximately 7% of cancer cells exhibited positivity for Sca-1 in primary mouse gastric cancer tissues. An in vivo-limiting dilution assay showed that Sca-1(high) mouse gastric cancer cells demonstrated increased tumorigenicity compared with Sca-1(negative) cells. The Sca-1 expression was downregulated by TGF-β pathway activation and Wnt pathway inhibition in mouse gastric cancer cells. Sca-1(high) cells showed relatively low TGF-β reporter activity and high TCF/LEF1 reporter activity compared with Sca-1(negative) cells. A chromatin immunoprecipitation analysis demonstrated that Sca-1 was a β-catenin/LEF1 target gene. Sca-1(high) allografts were more resistant to cisplatin/fluorouracil chemotherapy than Sca-1(negative) allografts, and overexpressed Bcl-xL. Eighty-five mouse genes overexpressed in Sca-1(high) S1 cells compared with Sca-1(negative) cells clustered 123 pretreatment gastric cancer patient samples according to survival following chemotherapy. Taken together, Sca-1 is a novel CSC enrichment marker that mediates TGF-β and Wnt/β-catenin signaling in mouse gastric cancer. Stem Cells 2016;34:1177-1187.

Epinecidin-1 antimicrobial activity: In vitro membrane lysis and In vivo efficacy against Helicobacter pylori infection in a mouse model

Helicobacter pylori (H. pylori) infection is highly prevalent, and has a strong association with various gastric diseases, including gastritis, digestive ulcers, and cancer. H. pylori strains with resistance to existing antibiotics have emerged in the past two decades. Currently, treatment of H. pylori infection (involving the use of proton pump inhibitors, followed by triple therapy with broad-spectrum antibiotics) is suboptimal, with high failure rates. As such, there is a clear need for new approaches against H. pylori. Here, we report that Epinecidin-1 (Epi-1) shows effective bactericidal activity against H. Pylori in vitro, and modulates H. Pylori-induced host immune responses in a mouse model. Epi-1 exhibited a low minimum inhibitory concentration (MIC) against antibiotic-sensitive and clinical antibiotic-resistant strains. Moreover, Epi-1 treatment caused 1-N-phenylnaphthylamine (NPN)-fluorescent probe uptake, suggesting it induced membrane lysis; transmission electron micrographs revealed that membranes were destabilized by the generation of saddle-splay membrane curvature. Oral administration of Epi-1 (quaque die dose) in a mouse infection model had strong efficacy (p < 0.00152) against H. pylori, as compared with conventional proton pump inhibitor (PPI)-triple therapeutic antibiotics. Epi-1 inhibited infection through in vivo depletion of CD4+-FOXP3+ T Regulatory and Th17 subset populations, and aided in clearance of persistent H. pylori colonization. Flow cytometry and gene expression analysis of mouse splenic and gastric tissue indicated that Epi-1 inhibits IL-10, and thereby affects FOXP3 expression levels and reduces pro-inflammatory cytokine responses. Crucially, high doses of Epi-1 did not exert toxic effects in oral, dermal, and eye irritation models. Collectively, our results suggest that Epi-1 may be a promising, effective, and safe monotherapeutic agent for the treatment of multi-drug resistant H. pylori infection.

Effect of recombinant human lactoferrin treatment on mRNA expression of vacuolating cytotoxin A and content of tumor necrosis factor-α in gastric tissue of mice with Helicobacter pylori-associated gastritis

Effect of recombinant human lactoferrin treatment on mRNA expression of vacuolating cytotoxin A and content of tumor necrosis factor-α in gastric tissue of mice with <i>Helicobacter pylori</i>-associated gastritis

Helicobacter pylori generates cells with cancer stem cell properties via epithelial–mesenchymal transition-like changes

Helicobacter pylori infection is the major risk factor for gastric adenocarcinoma. The link with gastric adenocarcinoma is partly due to the H. pylori CagA oncoprotein. CagA is responsible for a particular cell phenotype in vitro, the 'hummingbird' phenotype, that corresponds to an elongation of the cells, mimicking an epithelial-mesenchymal transition (EMT). EMT participates in the carcinogenesis process, and is involved in the generation of cancer stem cells (CSCs). However, its involvement in gastric carcinogenesis has yet not been studied. Therefore, the aim of this study was to determine the role of H. pylori in EMT and in the emergence of gastric CSCs. For this purpose, gastric epithelial cells were cocultured with a cagA-positive H. pylori strain or its isogenic-deleted mutants or were transfected with CagA expression vectors. Study of the expression of epithelial and mesenchymal markers showed that H. pylori, via CagA, is responsible for an EMT phenotype associated with an increase in mesenchymal markers as well as CD44 expression, a known gastric CSC marker. Moreover, infection led to an increased ability to migrate, to invade and to form tumorspheres. Cell sorting experiments showed that only the CD44(high) cells induced by H. pylori infection displayed the mesenchymal phenotype and CSC properties in vitro, and had higher tumorigenic properties than CD44(low) cells in xenografted mice. Immunohistochemistry analyses on human and mouse gastric mucosa tissue samples confirmed a high expression of CD44 and mesenchymal markers in H. pylori-infected cases, and in gastric dysplasia and carcinoma. All of these data suggest that H. pylori, via CagA, unveils CSC-like properties by induction of EMT-like changes in gastric epithelial cells.

Risk assessment of mouse gastric tissue cancer induced by dichlorvos and dimethoate

Cancer hazards from pesticide residues in food have been much discussed in the past decade. In this study, we showed that dichlorvos and dimethoate affect hemoglobin content and hematocrit value, but had no effect on red blood cell counts and total plasma protein in mice. A 40-mg/kg/day dose of dichlorvos upregulated the expression of p16, Bcl-2 and c-myc genes in mouse gastric tissue. By contrast, expression of the p16, Bcl-2 and c-myc genes induced by low doses (5, 10 and 20 mg/kg/day) of dichlorvos demonstrated no change in the control check group (CK; 200 μl sterile saline perfused group; 0 mg/kg/day). Different doses of dimethoate all upregulated the expression of p16, Bcl-2 and c-myc genes in mouse gastric tissue. The results further demonstrated that mouse gastric tissue, exposed in the long-term to low doses of dichlorvos and dimethoate, has the potential to become cancerous.

DL-trans-3,4-Dihydroxy-1-selenolane (DHSred) accelerates healing of indomethacin-induced stomach ulceration in mice

Management of the gastro-toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) remains a crucial problem, because the commercially available anti-ulcer drugs have side effects and are often expensive. Hence, the potential of a new water-soluble GPx mimic, DL-trans-3,4-dihydroxy-1-selenolane (DHSred) in healing the indomethacin-induced stomach ulceration in mice was examined. Administration of indomethacin (18 mg/kg, p. o.) induced ulceration in the glandular portion of the gastric mucosa, accompanied by increased lipid peroxidation (1.3-fold, p <0.001) and protein oxidation (1.5-fold, p < 0.001), depletion of thiol-defense (42.5%, p < 0.01), plasma total antioxidant status (53.4%, p < 0.001) and mucin (47.5%, p < 0.01), as well as reduced expressions of cyclooxygenases and prostaglandin synthesis (54.7%, p < 0.001) in the gastric tissues of mice. Daily oral administration of DHSred (2.5 mg/kg) or omeprazole (Omez) (3 mg/kg) for 3 days respectively produced ˜74% and 69% (p < 0.001) healing of the acute gastric ulceration. The test samples also significantly reversed all the adverse effects of indomethacin on the biochemical parameters. Apparently, the gastric ulcer healing action of DHSred and Omez was due to their antioxidant action and their ability to protect mucin and augment PG synthesis by upregulation of the COX isozymes. The results suggested that the non-toxic and inexpensive compound, DHSred, may be a good candidate for further evaluation as a potent anti-ulcer drug.

Regulation of Helicobacter pylori adherence by gene conversion

Genetic diversification of Helicobacter pylori adhesin genes may allow adaptation of adherence properties to facilitate persistence despite host defences. The sabA gene encodes an adhesin that binds sialyl-Lewis antigens on inflamed gastric tissue. We found variability in the copy number and locus of the sabA gene and the closely related sabB and omp27 genes due to gene conversion among 51 North American paediatric H. pylori strains. We determined that sabB to sabA gene conversion is predominantly the result of intra-genomic recombination and RecA, RecG and AddA influence the rate at which it occurs. Although all clinical strains had at least one sabA gene copy, sabA and sabB were lost due to gene conversion at similar rates in vitro, suggesting host selection to maintain the sabA gene. sabA gene duplication resulted in increased SabA protein production and increased adherence to sialyl-Lewis antigens and mouse gastric tissue. In conclusion, gene conversion is a mechanism for H. pylori to regulate sabA expression level and adherence.

A possible role of cIAP2 in Helicobacter pylori-associated gastric cancer

Cellular inhibitor of apoptosis protein 2 (cIAP2) is a member of the IAP family and is over-expressed in most cancer tissues. In this study, we investigated the role cIAP2 in Helicobacter pylori (HP) related gastric carcinogenesis. We measured the expression of cIAP2 at mRNA and protein levels in a panel of gastric cancer cell lines and human gastric cancer tissues by semi-quantitative reverse transcriptase PCR (RT-PCR), quantitative real time PCR (qPCR), immunoblotting, and immunohistochemistry. The effects of cIAP2 down-regulation on gastric cell proliferation and apoptosis were detected by standard WST-1 assay and flow cytometry, respectively. Infection of gastric mucosa by HP enhances the expression of cIAP2 in mouse gastric tissues. Over 70% of human gastric cancer tissues express higher amount of cIAP2. Well-differentiated gastric cancer cells express more cIAP2 than moderately- and poorly-differentiated gastric cancer cells. Knocking down of cIAP2 in SGC-7901 cells results in a 30% decrease in cell proliferation, a 20% increase in apoptosis and delayed migration. Thus, cIAP2 may play an important role in HP-induced gastric carcinogenesis, and it may serve as a potential target for gastric cancer therapy.

Loss of NRF2 impairs gastric nitrergic stimulation and function

Emerging research suggests that antioxidant gene expression has the potential to suppress the development of gastroparesis. However, direct genetic evidence that definitively supports this concept is lacking. We used mice carrying a targeted disruption of Nfe2l2, the gene that encodes the transcription factor NRF2 and directs antioxidant Phase II gene expression, as well as mice with a targeted disruption of Gclm, the modifier subunit for glutamate–cysteine ligase, to test the hypothesis that defective antioxidant gene expression contributes to development of gastroparesis. Although expression of heme oxygenase-1 remained unchanged, expression of GCLC, GCLM, SOD1, and CAT was down-regulated in gastric tissue from Nrf2−/− mice compared to wild-type animals. Tetrahydrobiopterin oxidation was significantly elevated and nitrergic relaxation was impaired in Nrf2−/− mouse gastric tissue. In vitro studies showed a significant decrease in NO release in Nrf2−/− mouse gastric tissue. Nrf2−/− mice displayed delayed gastric emptying. The use of Gclm−/− mice demonstrated that the loss of glutamate–cysteine ligase function enhanced tetrahydrobiopterin oxidation while impairing nitrergic relaxation. These results provide genetic evidence that loss of antioxidant gene expression can contribute to the development of gastroparesis and suggest that NRF2 represents a potential therapeutic target.

Curcumin Alleviates Matrix Metalloproteinase-3 and -9 Activities during Eradication of Helicobacter pylori Infection in Cultured Cells and Mice

Current therapy-regimens against Helicobacter pylori (Hp) infections have considerable failure rates and adverse side effects that urge the quest for an effective alternative therapy. We have shown that curcumin is capable of eradicating Hp-infection in mice. Here we examine the mechanism by which curcumin protects Hp infection in cultured cells and mice. Since, MMP-3 and -9 are inflammatory molecules associated to the pathogenesis of Hp-infection, we investigated the role of curcumin on inflammatory MMPs as well as proinflammatory molecules. Curcumin dose dependently suppressed MMP-3 and -9 expression in Hp infected human gastric epithelial (AGS) cells. Consistently, Hp-eradication by curcumin-therapy involved significant downregulation of MMP-3 and -9 activities and expression in both cytotoxic associated gene (cag)+ve and cag -ve Hp-infected mouse gastric tissues. Moreover, we demonstrate that the conventional triple therapy (TT) alleviated MMP-3 and -9 activities less efficiently than curcumin and curcumin's action on MMPs was linked to decreased pro-inflammatory molecules and activator protein-1 activation in Hp-infected gastric tissues. Although both curcumin and TT were associated with MMP-3 and -9 downregulation during Hp-eradication, but unlike TT, curcumin enhanced peroxisome proliferator-activated receptor-γ and inhibitor of kappa B-α. These data indicate that curcumin-mediated healing of Hp-infection involves regulation of MMP-3 and -9 activities.