The preproghrelin 3056 TT genotype is associated with the feeling of hunger and low acylated ghrelin levels in Japanese patients with Helicobacter pylori-negative functional dyspepsia.

OBJECTIVE: An impairment of gastric motility is strongly associated with the pathophysiology of functional dyspepsia (FD). Plasma ghrelin is one of the key molecules linked to gastric motility. Therefore, this study aimed to evaluate whether ghrelin (GHRL) gene polymorphisms are associated with clinical symptoms, the plasma ghrelin levels and gastric emptying in patients with FD as defined by the Rome III classification. METHODS: We enrolled 74 Helicobacter pylori-negative patients presenting with typical symptoms of FD (epigastric pain syndrome (EPS), n=23; postprandial distress syndrome (PDS), n=51) and 102 healthy volunteers. Gastric motility was evaluated according to the Tmax value and T1/2 using the (13)C-acetate breath test. We used the Rome III criteria to evaluate upper abdominal symptoms and SRQ-D scores to determine the depression status. The Arg51Gln(346G->A), preproghrelin3056T->C, Leu72Met(408C->A) and Gln90Leu(3412T->A) polymorphisms were analyzed in DNA in blood samples obtained from the enrolled subjects. Genotyping was performed using polymerase chain reaction. RESULTS: There was a significant relationship (p=0.048) between the preproghrelin 3056TT genotype and the serum levels of acylated ghrelin in the H. pylori-negative FD patients. The preproghrelin 3056TT genotype was significantly (p=0.047) associated with the feeling of hunger in the H. pylori-negative FD patients. CONCLUSION: The preproghrelin 3056TT genotype is significantly associated with the acylated ghrelin levels and the feeling of hunger in H. pylori-negative FD patients. Further studies are needed to clarify the association between the preproghrelin 3056TT genotype and lower plasma acylated ghrelin levels and the impact of this relationship on the feeling of hunger in H. pylori-negative FD patients.

Pathophysiology of functional dyspepsia.

Functional dyspepsia is a highly prevalent and heterogeneous disorder. Functional dyspepsia involves many pathogenic factors, such as gastric motility disorders, visceral hypersensitivity, psychological factors, Helicobacter pylori infection, and excessive gastric acid secretion. The present article provides an overview of pathogenetic factors and pathophysiologic mechanisms.

Migration of eosinophils and CCR2-/CD68-double positive cells into the duodenal mucosa of patients with postinfectious functional dyspepsia.

OBJECTIVES: Recent studies have shown that postinfectious functional dyspepsia (FD) symptoms may persist after elimination of gastrointestinal (GI) infection as well as postinfectious irritable bowel syndrome accompanying colonic inflammation. However, it is unclear whether intestinal chronic inflammation can contribute to clinical symptoms of certain FD patients such as postinfectious FD. To determine the relationship between local inflammation of the duodenum and clinical symptoms, we evaluated the infiltration of several phenotypes of duodenal inflammatory cells as well as gastric motility using (13)C urea breath test in postinfectious FD patients. METHODS: We enrolled 136 consecutive patients diagnosed with FD according to Rome III criteria, and 20 healthy controls, after upper GI endoscopy. Gastric motility was evaluated by gastric emptying time (T-max) using the (13)C-acetate breath test. Upper abdominal symptoms including epigastric pain, epigastric burning, postprandial fullness, abdominal distension, and early satiety were assessed by questionnaire scores. We obtained biopsy specimens from the stomach and duodenum during upper GI endoscopy. Histological gastritis and duodenitis were assessed as mild, moderate, or severe according to previously described criteria. Characteristics of inflammatory cells and neuroendocrine cells were determined immunohistochemically with antibodies to CD3, CD68, CCR2, Vdelta1 TCR, and serotonin. RESULTS: Endoscopic duodenitis was observed in only 5.7% of postinfectious FD patients. However, the rates of histological duodenitis in duodenal biopsies of postinfectious FD patients were 17% for mild, 26% for moderate, and 57% for severe grades of duodenitis. The degree of histological duodenitis of postinfectious FD patients was significantly greater than that of healthy volunteers. There was a significant correlation between epigastric burning and the degree of duodenitis in postinfectious FD patients. There was no significant difference in histological duodenitis and T-max value in the postinfectious FD patients with or without Helicobacter pylori infection. In addition, CD68-positive cell number in postinfectious FD patients was significantly increased compared with the numbers in subjects with epigastric pain syndrome or postprandial distress syndrome and in healthy volunteers. CCR2-/CD68-double positive cell number in postinfectious FD patients was significantly (P=0.009) increased compared with those in healthy volunteers. CONCLUSIONS: Migration of inflammatory cells, in particular, duodenal CCR2-positive macrophages, may have an important function in the pathophysiology of postinfectious FD patients.

Cells of extraembryonic mesodermal origin confer human dystrophin in the mdx model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy is an X-linked recessive genetic disease characterized by severe skeletal muscular degeneration. The placenta is considered to be a promising candidate cell source for cellular therapeutics because it contains a large number of cells and heterogenous cell populations with myogenic potentials. We analyzed the myogenic potential of cells obtained from six parts of the placenta, that is, umbilical cord, amniotic epithelium, amniotic mesoderm, chorionic plate, villous chorion, and decidua basalis. In vitro cells derived from amniotic mesoderm, chorionic plate, and villous chorion efficiently transdifferentiate into myotubes. In addition, in vivo implantation of placenta-derived cells into dystrophic muscles of immunodeficient mdx mice restored sarcolemmal expression of human dystrophin. Differential contribution to myogenesis in this study may be attributed to placental portion-dependent default cell state. Molecular taxonomic characterization of placenta-derived maternal and fetal cells in vitro will help determine the feasibility of cell-based therapy.

Celecoxib inhibits CD133-positive cell migration via reduction of CCR2 in Helicobacter pylori-infected Mongolian gerbils.

BACKGROUND/AIMS: To see whether celecoxib prevents gastric cancer occurrence by disrupting the progression of chronic gastritis into gastric carcinoma through its inhibition of the migration of CD133-positive cells, one of the surface markers of bone marrow-derived cells, in Helicobacter pylori-infected gerbils. METHODS: 70 gerbils were divided into six groups. Group 1 gerbils served as control (n = 6). 10 gerbils were given N-methyl-N-nitrosourea (MNU), 30 ppm (group 2). 6 short-term Helicobacter pylori-infected gerbils (group 3) were sacrificed after 8 weeks of H. pylori infection and 6 long-term H. pylori-infected gerbils were sacrificed after 42 weeks of H. pylori infection (group 4). 20 gerbils were given MNU pretreatment and long-term H. pylori infection (group 5). In addition, after H. pylori inoculation, 22 gerbils also received a celecoxib in their diet (group 6). CD133 and CCR2 expression in gastric tissues was evaluated by Western blot analysis and immunostaining. RESULTS: CD133-positive cells were mainly localized in the bottom of the gastric epithelial cells. CD133-positive cells also migrated into gastric cancer tissues in this model. CD133-positive cells in MNU-pretreated H. pylori-infected gerbils were significantly increased compared to those in H. pylori short-term infected gerbils. Celecoxib treatment significantly reduced CD133-positive cell migration and CCR2 expression levels. CD133- and CCR2-positive cells were colocalized in H. pylori-infected gastritis and gastric cancer tissues. Celecoxib treatment significantly reduced the number of CD133- and CCR2-positive cells. CONCLUSIONS: Celecoxib inhibits CD133-positive cell migration via the reduction of CCR2 in this model. Further studies are needed to clarify the precise mechanisms driving H. pylori infection-induced CD133-positive cell migration and its link to the progression of chronic gastritis into gastric cancer.

The prokinetic effect of mosapride citrate combined with omeprazole therapy improves clinical symptoms and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying.

BACKGROUND: Previous studies have shown that non-erosive reflux disease (NERD) patients are less sensitive to proton pump inhibitor (PPI) treatment than patients with erosive reflux disease. The aim of this study was to investigate whether treatment with prokinetics in addition to omeprazole therapy would improve clinical symptoms, gastric emptying and esophageal peristalsis in PPI-resistant NERD patients with or without delayed gastric emptying. METHODS: Subjects were 64 consecutive patients presenting with typical symptoms of PPl-resistant NERD (n = 44) and 20 healthy volunteers. PPI-resistant NERD patients underwent mosapride citrate (15 mg/day) and omeprazole (20 mg/day) co-therapy for 12 weeks. We evaluated the clinical symptoms as well as gastric emptying and esophageal manometry before and after combined therapy. We measured both acylated- and des-acylated plasma ghrelin levels by the ELISA method. The primary endopoint was to investigate whether co-administration of mosapride citrate and omeprazole would improve clinical symptoms and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying. RESULTS: T (max) value in PPI-resistant NERD patients was significantly higher than in healthy volunteers. Combination therapy with the prokinetic agent mosapride citrate and omeprazole significantly improved reflux symptoms and T (max) value in T (max) > 65 min NERD patients. Co-therapy also significantly reduced des-acylated-ghrelin levels in NERD patients with delayed gastric emptying. CONCLUSIONS: Administration of mosapride citrate in addition to omeprazole improved gastro-esophageal reflux and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying.

Shortening of human cell life span by induction of p16ink4a through the platelet-derived growth factor receptor beta.

Mesenchymal stem cells (MSCs) are attracting a great deal of attention because they represent a valuable source of cells for use in regenerative medicine. In human cell culture it is important to obtain large numbers of cells for use in therapy. In this study, we attempted to prolong life span of a marrow-derived mesenchymal stem cell using a combination of growth factors and hormones. Furthermore we tested whether chemically defined culture conditions are sufficient for maintenance of multipotent mesenchymal stem cells. Epidermal growth factor, platelet-derived growth factor-BB (PDGF-BB), acidic fibroblast growth factor (FGF), basic FGF, and leukemia inhibitory factor were found to be key factors for the mesenchymal stem cell proliferation. The combination of these growth factors showed extremely strong mitogenic activity, and simultaneously induced the expression of cyclin-dependent kinase inhibitor p16ink4a protein and premature senescence more rapidly than serum-supported culture conditions. The induction of p16ink4a by growth factors was mediated through the mitogen-activated protein kinase (MAPK) cascade. Excess growth stimulation by growth factors was thus one of the culture stress signals and a trigger of premature senescence at least in human cells.

Comparison of gastric emptying and plasma ghrelin levels in patients with functional dyspepsia and non-erosive reflux disease.

BACKGROUND AND AIMS: The symptoms of postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), the two subtypes of functional dyspepsia (FD) under the new Rome III classification, tend to overlap with those of non-erosive reflux disease (NERD). Plasma ghrelin levels have been associated with gastric motility; however, clinical studies have yet to examine this relationship among patients with PDS, EPS or NERD. Thus, this study aims to evaluate the correlation between gastric emptying and ghrelin levels as possible candidate factors for gastric motility in these diseases. METHODS: One hundred and fifty-one patients presenting with typical symptoms of FD (EPS, n = 36; PDS, n = 76) or NERD (n = 39), and 20 healthy volunteers were enrolled. Gastric motility was evaluated with the T(max) value as a marker of gastric emptying using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms, and SRQ-D scores to determine depression status. We measured both acylated and des-acylated ghrelin levels by ELISA methods. RESULTS: The Tmax value in PDS patients was significantly higher than in healthy volunteers. Acylated ghrelin levels were significantly lower in NERD and PDS patients than in healthy volunteers. Interestingly, there was significant correlation between the acylated ghrelin levels and Tmax value in PDS patients but not in EPS or NERD patients. CONCLUSION: Our results suggest that acylated ghrelin might play an important role in the pathophysiology of PDS patients through its effect on gastric emptying.

Celecoxib inhibits apurinic/apyrimidinic endonuclease-1 expression and prevents gastric cancer in Helicobacter pylori-infected mongolian gerbils.

BACKGROUND AND AIMS: The aim of this study was to see whether administration of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, could prevent the development of gastric cancer via inhibition of apurinic/apyrimidinic endonuclease-1 (APE-1) expression induced by Helicobacter pylori infection. METHODS: 70 Mongolian gerbils were divided into 6 groups. Group 1 gerbils served as controls (n = 6). Ten gerbils were given N-methyl-N-nitrosourea (MNU), 30 ppm, 5 times biweekly (group 2). Short-term H. pylori infection was induced in 6 gerbils which were sacrificed 8 weeks after H. pylori infection (group 3). Long-term H. pylori infection was induced in 6 other gerbils which were sacrificed 44 weeks after H. pylori infection (group 4). Twenty gerbils were given MNU pretreatment 5 times biweekly and long-term H. pylori infection (group 5). In addition, after H. pylori inoculation, group 6 gerbils also received celecoxib with their diet for 26 weeks. APE-1 expression alone or with COX-2 in gastric tissues was evaluated by Western blot and immunohistological analysis. Myeloperoxidase (MPO) activity and thiobarbituric-acid-reactive substance (TBARS) levels were also evaluated. RESULTS: APE-1 was localized in gastric epithelial cells and mesenchymal cells including macrophages in H. pylori-infected gerbils. The numbers of APE-1-positive cells in group 4 and 5 were significantly increased compared to those of group 3. Celecoxib treatment significantly reduced MPO activity, TBARS levels and the incidence of gastric cancer. APE-1 and IkappaBalpha phosphorylation levels were significantly increased in MNU-pretreated H. pylori-infected gerbils compared to those in MNU-only gerbils. Celecoxib significantly reduced APE-1 and IkappaBalpha phosphorylation levels in MNU-pretreated H. pylori-infected gerbils. COX-2 and APE-1 were coexpressed in the macrophages of H. pylori-infected gerbils. CONCLUSION: Celecoxib prevented gastric cancer in MNU-pretreated H. pylori-infected gerbils with a reduction in APE-1 expression thereby suggesting the implication of APE-1 in gastric carcinogenesis in this model.

Expression of apurinic/apyrimidinic endonuclease-1 (APE-1) in H. pylori-associated gastritis, gastric adenoma, and gastric cancer.

BACKGROUND AND AIM: Apurinic/apyrimidinic endonuclease-1 (APE-1) is a key enzyme in DNA base excision repair (BER), linked to cancer chemosensitivity. However, little is known about the localization of APE-1 in Helicobacter pylori-infected gastric mucosa or its role in the development of gastric cancer. To investigate the role of APE-1 in the development of gastric cancer, we examined APE-1 expression and localization in cultured cells and gastric biopsies from patients with H. pylori-infected gastritis or gastric adenoma, and from surgically resected gastric cancer. METHODS: APE-1 mRNA and protein expression were determined in H. pylori (CagA+) water-extract protein (HPWEP)-stimulated MKN-28 cells, gastric adenocarcinoma cell-line (AGS) cells, and human peripheral macrophages by real-time polymerase chain reaction and Western blot analysis. APE-1 expression and 8-OHdG as a measure of oxidative DNA damage were evaluated by immunostaining. Localization of APE-1 and IkappaBalpha phosphorylation in gastric adenoma and gastric cancer tissues were evaluated by single- and double-label immunohistochemistry. RESULTS: In studies in vitro, HPWEP-stimulation significantly increased APE-1 mRNA expression levels in both MKN-28 cells and human peripheral macrophages. Hypo/reoxygenation treatment significantly increased APE-1 protein expression in HPWEP-stimulated MKN-28 cells. HPWEP stimulation significantly increased both APE-1 expression and IkappaBalpha phosphorylation levels in MKN-28 and AGS cells. In human tissues, APE-1 expression in H. pylori-infected gastritis without goblet cell metaplasia was significantly increased as compared to that in tissues from uninfected subjects. Eradication therapy significantly reduced both APE-1 and 8-OHdG expression levels in the gastric mucosa. APE-1 expression was mainly localized in epithelial cells within gastric adenoma and in mesenchymal cells of gastric cancer tissues. APE-1 expression in gastric cancer tissues was significantly reduced compared to that in H. pylori-infected gastric adenoma, while 8-OHdG index and IkappaBalpha phosphorylation levels did not differ between these two neoplastic tissue types. Co-localization of APE-1 and IkappaBalpha phosphorylation was observed not in gastric cancer cells but in gastric adenoma cells. CONCLUSION: H. pylori infection is associated with increased APE-1 expression in human cell lines and in gastric tissues from subjects with gastritis and gastric adenomas. The observed distinct expression patterns of APE-1 and 8-OHdG in gastric adenoma and gastric cancer tissues may provide insight into the progression of these conditions and warrants further investigation.

Monocyte chemoattractant protein 1 and CD40 ligation have a synergistic effect on vascular endothelial growth factor production through cyclooxygenase 2 upregulation in gastric cancer.

BACKGROUND: Recent studies have reported that expression of monocyte chemoattractant protein 1 (MCP-1) and its receptor (CCR2) and CD40 ligation on mesenchymal cells play important roles in tumor development. Cyclooxygenase 2 (COX-2) has also been shown to contribute to tumor angiogenesis. We examined the interaction between MCP-1 and CD40 ligation in mesenchymal cells in gastric cancer to determine the effect of these factors on vascular endothelial growth factor (VEGF) production via upregulation of COX-2 expression. METHODS: COX-2, prostaglandin E2 (PGE2), and VEGF production were evaluated in CD40 ligand (CD40L)-stimulated macrophages. CD40L and MCP-1 mRNA levels in gastric cancer tissues were evaluated by real-time polymerase chain reaction (PCR). Localizations of MCP-1, CD40L, CD34, CD40, and CCR2 in 34 gastric cancer tissue specimens were evaluated by single-or double-label immunohistochemistry. RESULTS: COX-2 expression levels were significantly higher in CD40L-stimulated macrophages and correlated with increased PGE2 and VEGF production. Addition of MCP-1 to CD40L-stimulated macrophages had a synergistic effect on COX-2 expression and subsequent PGE2 and VEGF production. CD40L and MCP-1 mRNA levels were significantly higher in poorly differentiated gastric cancers than in H. pylori-infected gastritis patients. High microvessel density was significantly associated with MCP-1 and CCR2 scores and lymph node metastasis. CONCLUSIONS: MCP-1 and CD40L had a synergistic effect on COX-2 expression and subsequent VEGF production in gastric cancer.

Extracellular HSP70 blocks CD40L-induced apoptosis and tubular formation in endothelial cells.

BACKGROUND: Recent studies have shown that CD40, a key player in angiogenesis and tubular formation, is an extracellular receptor of the heat shock protein 70 (HSP70)-peptide complex in endothelial cells. The aim of the present study was to determine the effect of extracellular HSP70 treatment on CD40L-suppressed apoptosis and CD40L-induced tubular formation in human umbilical vein endothelial cells (HUVEC). METHODS: The apoptotic index of CD40L-stimulated HUVEC with or without recombinant human HSP70 was evaluated using terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay analysis. Binding of HSP70-peptide complex to CD40 on HUVEC was determined by double-labeling immunofluorescence methods. To evaluate the biological activity of CD40 engagement pretreated with rhHSP70 (0.5, 1 and 3 ng/mL), the extent of new capillary-like networking structure (tubular formation) formation in HUVEC was counted using an Olympus digital camera. Vascular invasion into MNK-28 cell clusters was assessed by counting the number of tubular structures extending from the HUVEC into growth factor-depleted Matrigel. Scores for CD34, HSP70 and CD40L expression levels in gastric cancer tissues were determined by immunostaining. RESULTS: CD40L stimulation inhibited vincristine-induced apoptosis of HUVEC in a dose-dependent manner. Extracellular HSP70 treatment significantly blocked the inhibition of apoptosis by CD40L in HUVEC exposed to vincristine. HSP70-peptide complex bound to CD40 on HUVEC. Extracellular HSP70 treatment also significantly reduced CD40L-induced tubular formation in a dose-dependent manner. HSP70 treatment also suppressed invasive tubular formation into MKN-28 cells clusters by CD40L-activated HUVEC. There was a significant relationship between CD40L expression levels and microvessel density; however, the relationship between HSP70 expression level and microvessel density in gastric cancer tissues was not significant. CONCLUSIONS: Extracellular HSP70 treatment blocks CD40L inhibition of apoptosis and CD40L induction of tubular formation in HUVEC.

Thermodynamic analysis of the activation mechanism of the GCSF receptor induced by ligand binding.

The granulocyte colony-stimulating factor receptor (GCSFR), containing the Ig-like domain (Ig) and cytokine receptor homologous region (CRH), was prepared as a preformed dimer (Ig-CRH-Fc)(2) after fusion to the mouse Fc region via an eight-residue linker (approximately 55 A). Monomer Ig-CRH was also prepared after the Fc region was removed from (Ig-CRH-Fc)(2). GCSF binding to Ig-CRH and (Ig-CRH-Fc)(2) was investigated using light scattering and isothermal titration calorimetry. The average molecular mass determined by light scattering showed that both Ig-CRH and (Ig-CRH-Fc)(2) formed a 2:2 dimer with GCSF. Moreover, isothermal titration calorimetry showed that the thermodynamic parameters upon binding of GCSF to Ig-CRH and (Ig-CRH-Fc)(2) were comparable, suggesting a similar binding stoichiometry and interface [including similar buried surface area (5700-6000 A(2))] despite the presence of the eight-residue linker. The buried surface area is much larger than that calculated from our previous report of the crystal structure of the GCSF-CRH complex [Aritomi, M., et al. (1999) Nature 401, 713-717], suggesting a substantial contribution of the Ig domain to GCSF binding. The data also indicate that the distance (55 A) between two CRH domains in the 2:2 complex is much shorter than in our previous model (approximately 90 A) predicted from the same crystal structure of the GCSF-CRH complex.