Efficacy of acotiamide on postprandial distress syndrome and epigastric pain syndrome depending on the estimated gastric acid secretion level.

BACKGROUND/AIMS: Gastric acid secretion is suspected to be a pivotal contributor to the pathogenesis of functional dyspepsia. The present study investigates the potential association of the gastric acid secretion estimated by measuring serum pepsinogen with therapeutic responsiveness to the prokinetic drug acotiamide. METHODS: Dyspeptic patients consulting participating clinics from October 2017 to March 2019 were prospectively enrolled in the study. The dyspeptic symptoms were classified into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). Gastric acid secretion levels were estimated by the Helicobacter pylori infection status and serum pepsinogen using established criteria and classified into hypo-, normo-, and hyper-secretion. Each patient was then administered 100 mg acotiamide thrice daily for 4 weeks, and the response rate to the treatment was evaluated using the overall treatment efficacy scale. RESULTS: Of the 86 enrolled patients, 56 (65.1%) and 26 (30.2%) were classified into PDS and EPS, respectively. The estimated gastric acid secretion was not significantly different between PDS and EPS. The response rates were 66.0% for PDS and 73.1% for EPS, showing no significant difference. While the response rates were stable, ranging from 61.0% to 75.0% regardless of the estimated gastric acid secretion level among subjects with PDF, the rates were significantly lower in hyper-secretors than in non-hyper-secretors among subjects with EPS (42.0% vs 83.0%, P = 0.046). CONCLUSION: Although acotiamide is effective for treating EPS as well as PDS overall, the efficacy is somewhat limited in EPS with gastric acid hypersecretion, with gastric acid suppressants, such as proton pump inhibitors, being more suitable.

Traditional Herbal Medicine, Rikkunshito, Induces HSP60 and Enhances Cytoprotection of Small Intestinal Mucosal Cells as a Nontoxic Chaperone Inducer.

Increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with recent advances of endoscopic technology. However, the pathogenesis and therapy are not fully understood. The aim of this study is to examine the effect of Rikkunshito (TJ-43), a traditional herbal medicine, on expression of HSP60 and cytoprotective ability in small intestinal cell line (IEC-6). Effect of TJ-43 on HSP60 expression in IEC-6 cells was evaluated by immunoblot analysis. The effect of TJ-43 on cytoprotective abilities of IEC-6 cells against hydrogen peroxide or indomethacin was studied by MTT assay, LDH-release assay, caspase-8 activity, and TUNEL. HSP60 was significantly induced by TJ-43. Cell necrosis and apoptosis were significantly suppressed in IEC-6 cells pretreated by TJ-43 with overexpression of HSP60. Our results suggested that HSP60 induced by TJ-43 might play an important role in protecting small intestinal epithelial cells from apoptosis and necrosis in vitro.

Evidence for enhanced cytoprotective function of HSP90-overexpressing small intestinal epithelial cells.

BACKGROUND: In the clinical field, increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with the advances of capsule endoscopy and balloon enteroscopy technology for the detection of small intestinal lesions. However, the pathogenesis of NSAID-induced mucosal damage, defensive mechanism of intestinal epithelial cells, and therapy for small intestinal mucosal lesion have not been fully understood. Heat shock proteins (HSPs) are involved in cytoprotection mediated by their function as a molecular chaperone. Since the function of HSP90 in the intestinal epithelial cells has not been well investigated, we examined the cytoprotective ability of HSP90-overexpressing small intestinal epithelial cells against hydrogen peroxide-induced or indomethacin-induced cell damage. METHODS: cDNA of human HSP90 gene was transfected to rat small intestinal epithelial cells (IEC-6 cells), and HSP90-overexpressing cells (IEC-6-90 cells) were selected and cloned. Anti-necrotic abilities and anti-apoptotic abilities of IEC-6-90 cells were compared with IEC-6-mock cells (transfected with vector alone). To examine the specific contribution of HSP90 on cytoprotection of IEC-6-90 cells, cytoprotective ability of IEC-6-90 cells was analyzed with or without pretreatment with functional inhibitor of HSP90, geldanamycine analog, followed by hydrogen peroxide-challenge or indomethacin-challenge. RESULTS: Hydrogen peroxide-induced or indomethacin-induced cell necrosis and apoptosis were significantly suppressed in IEC-6-90 cells. The cytoprotective ability of IEC-6-90 cells was suppressed by HSP90 inhibitor. CONCLUSIONS: Our results suggest that HSP90 might play an important role in protecting small intestinal epithelial cells from hydrogen peroxide-induced or indomethacin-induced cell injury in vitro, and raised the possibility of protection of small intestinal epithelial cells by manipulation of HSP90 expression.

Mobile echoes in liver cysts: a form of range-ambiguity artifact.

PURPOSE: Faint moving echoes are occasionally encountered in large hepatic cysts, as an example of range-ambiguity artifacts. The aim of this article is to describe the pattern of these intracystic mobile echoes, to analyze the mechanism of their formation, and to discuss options to clear them. METHODS: We analyzed the size and location of the hepatic cysts, the movement of the artifactual echoes, and the relationship between pulse repetition frequency (PRF) and the depth of these intracystic mobile echoes in 10 cases. In three cases examination at a lower PRF was made to ascertain whether the artifactual echoes would disappear. RESULTS: Intracystic range-ambiguity echoes appeared when the heart was located distal to the hepatic cyst and these echoes moved according to cardiac motion. The depth of the intracystic artifacts changed according to the PRF and they disappeared at a low PRF. CONCLUSION: Intracystic range-ambiguity artifacts are caused by an erroneous display of the returning echoes from the heart. Knowledge of the mechanism and appearance of this artifact helps prevent misdiagnosis of internal echoes in large hepatic cysts. Observation at different PRFs is key to recognizing this artifact, and examination at lower PRFs should be done to confirm the artifactual nature of the echoes.

Correlation of heat shock protein expression to gender difference in development of stress-induced gastric mucosal injury in rats.

Recent studies have indicated that heat shock proteins (HSPs), which function as molecular chaperones, play important roles in cellular responses to stress-related events. However, the gender difference in the expression of HSP in the gastric mucosa remains unclear. In order to understand the mechanism of gender difference in the prevalence or severity of gastric mucosal lesions, the expression level of HSP and the correlation of estrogen to HSP induction in the gastric mucosa were evaluated in this study. The basal expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. The gastric ulcer index was significantly higher in male rats compared to female rats observed after 12 h water immersion stress exposure. At this time point, the expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. An estrogen-treatment significantly induced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Inversely, an ovariectomy dramatically reduced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Our results suggested that estrogen might play an important role in gastric mucosal protection with the induction of gastric mucosal HSPs.

Overexpression of a 60-kDa heat shock protein enhances cytoprotective function of small intestinal epithelial cells.

AIMS: With the advancement of small intestinal (double balloon and capsule) endoscopy technology, incidence of small intestinal lesion caused by nonsteroidal anti-inflammatory drugs (NSAIDs) has been known to be high. However, therapy for small intestinal mucosal lesion has not yet been developed. Previous studies have shown that heat shock proteins (HSPs) are involved in cytoprotection mediated by their function as a molecular chaperone. In this study, we examined the effect of HSP60 or HSP70 overexpression on hydrogen peroxide-induced (H2O2) or indomethacin-induced cell damage in the small intestinal epithelial cells. MAIN METHODS: cDNA of human HSP60 or HSP70 was transfected to rat small intestinal (IEC-6) cells, and HSP60- or HSP70-overexpressing cells were cloned. IEC-6 cells transfected with vector only were used as control cells. These cells were treated with H2O2 (0-0.14mM) or indomethacin (0-2.5mM). The cell viability was determined by MTT-assay. Cell necrosis was evaluated by LDH-release assay. Further, apoptosis was evaluated by caspases-3/7 activity and TUNEL assay. KEY FINDINGS: Cell viability after H2O2 or indomethacin treatment was significantly higher in HSP60-overexpressing cells compared with that in control cells and HSP60-overexpressing cells. Apoptotic cells were also reduced in HSP60-overexpressing. CONCLUSION: These results indicate that HSP60 plays an important role in protecting small intestinal mucosal cells from H2O2-induced or indomethacin-induced cell injury. HSP70-overexpressing cells did not show anti-apoptotic ability. SIGNIFICANCE: These findings possibly suggest that function of each HSP is different in the small intestine. Therefore, for the therapy of small intestinal mucosal lesion, HSP60-induction therapy could be a new therapeutic strategy.

Expression and function of stress (heat shock) proteins in gastrointestinal tract.

This review will focus on gastrointestinal mucosal protection against cytotoxic agents and cellular stress mainly from the viewpoint of expression and function of heat shock proteins, in their role of 'molecular chaperones', as internal cytoprotectants. Also, recently identified target molecules of heat shock protein in damaged gastric mucosal cells are introduced. Elucidation of such stress-responses and repairing process of damaged protein by heat shock proteins in the gastrointestinal mucosa may provide a better understanding for the mechanisms of cytoprotection and cellular repair. In addition, these findings in post-genomic level may provide new strategies for the therapy of gastrointestinal disorders.

Attenuation of gastric mucosal inflammation induced by indomethacin through activation of the A2A adenosine receptor in rats.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin induce gastric mucosal lesions in part by the activation of inflammatory cells and the production of proinflammatory cytokines. The activation of adenosine A(2A) receptors inhibits inflammation by increasing cyclic AMP in leukocytes and reducing both the production of various proinflammatory cytokines and neutrophil chemotaxis. The aim of present study was to determine whether administration of an orally active adenosine A(2A) receptor agonist (4-[3-[6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl]-piperidine-1-carboxylic acid methyl ester; ATL-313) ameliorated indomethacin-induced gastric mucosal lesions in rats. METHODS: Gastric lesions were produced by oral gavage of indomethacin (30 mg/kg). ATL-313 (1-10 microg/kg) was given orally just before the indomethacin administration. RESULTS: The ulcer index induced by indomethacin was significantly (>50%) reduced by pretreatment with ATL-313 and this effect was blocked completely by the addition of equimolar ZM241385, a selective A(2A) receptor antagonist. The gastric content of myeloperoxidase (MPO) and proinflammatory cytokines was significantly reduced by 10 microg/kg ATL-313, but gastric mucosal prostaglandin 2 (PGE2) was not affected. CONCLUSION: We conclude that ATL-313 does not inhibit the mucosal damaging effect of indomethacin, but it does block secondary injury due to stomach inflammation. A(2A) agonists may represent a class of new therapeutic drugs for NSAID-induced gastric ulcers.

Target molecules of molecular chaperone (HSP70 family) in injured gastric mucosa in vivo.

AIMS: Several recent studies, including ours, have indicated the importance of heat shock proteins (HSPs) in cytoprotection against cytotoxic agents and environmental stresses mediated by the chaperone function of HSPs (molecular chaperones). However, the target molecule that is recognized by HSPs in damaged cells currently remains unknown. As HSPs rapidly recognize and bind to degenerated protein in cells, target molecules of HSPs might be key molecules for the initiation and pathogenesis of cellular damage. In the present study, gastric mucosal proteins that specifically bind to the HSP70 family (HSC70) were analyzed using HSC70-affinity chromatography. MAIN METHODS: The gastric mucosa was removed from Sprague-Dawley rats after exposure to water immersion-stress for 0, 1, 3 or 5 h. Soluble fractions of each gastric mucosa were applied to the HSC70-affinity column separately. After washing off non-specific binding proteins, specific binding proteins were eluted by ATP-containing buffer. Binding proteins were analyzed by SDS-polyacrylamide gel electrophoresis. In addition, the amino acid sequence of purified proteins was also analyzed. KEY FINDINGS: Specific HSC70-binding proteins with a molecular weight of 200-kDa and 45-kDa were eluted from an affinity column when gastric mucosal homogenate of 1-h stress exposure was applied. The amino acid sequencing showed that these binding proteins were cytoskeletal myosin (heavy chain) and actin, respectively. SIGNIFICANCE: During the pathogenesis of stress-induced gastric mucosal damage, structurally degenerated cytoskeletal myosin (heavy chain) and actin may be key or initiation molecules which structural changes were firstly recognized by molecular chaperone.

Gallbladder hernia into the foramen of Winslow: CT findings.

We present a case of gallbladder hernia into the foramen of Winslow. During the diagnosis of hernia, ultrasonography, computed tomography and intravenous computed tomography, cholangiography of the abdomen were performed. Ultrasonography detected gallstone, but did not provide sufficient information to diagnose gallbladder hernia. Computed tomography yielded the correct diagnosis. At laparoscopic cholecystectomy, the diagnosis was confirmed.

Hamartomatous inverted polyp successfully treated by endoscopic submucosal dissection.

We report a case of gastric hamartomatous inverted polyps that are a rare histological type of gastric polyp and difficult to diagnose. Gastric submucosal tumor was detected by upper gastrointestinal X-ray series in 37-year-old man. Endoscopy revealed a submucosal tumor (SMT) , which eroded with a depression on its surface in the fornix. Endoscopic ultrasonography showed a heterogeneous tumor in the third layer. Endoscopic submucosal dissection (ESD) was performed to resect the tumor completely. The pathological diagnosis was a gastric hamartomatous inverted polyp. The patient was later discharged without any complications. Hamartomatous inverted polyps without a stalk are classified as the SMT type because the tumor is inverted down growth into the submucosal layer, otherwise polyps with a stalk are classified as the polyp type. All of the polyps were resected endoscopically, however, surgical resection was performed for those of the SMT type, because it is difficult to remove this type completely by en-block resection using conventional EMR technique. ESD method may be indicated for SMT-type hamartomatous inverted polyps.

Effect of alcohol consumption on leptin level in serum, adipose tissue, and gastric mucosa.

It has been reported that the stomach is a source of leptin, which is the product of the obese (ob) gene. In the present study, the effect of alcohol on leptin level in serum, gastric mucosa, and adipose tissue was studied to understand the relationship between appetite and alcohol consumption. Male Sprague-Dawley rats were administered 1 ml of 25% ethanol perorally. Leptin levels in the serum, gastric mucosa, and adipose tissue were measured. The serum leptin level was significantly decreased 3 and 6 hr after ethanol administration, although the gastric leptin level was not affected. The leptin level in the adipose tissue was significantly increased 3 hr after administration. We conclude that the decreased serum leptin level after ethanol administration might be due to suppression of leptin secretion from adipose tissue to the systemic circulation. These findings might be important for understanding the relationship between alcohol consumption and appetite.

Attenuation of gastric mucosal inflammation induced by aspirin through inhibition of selective type III phospshodiesterase in rats.

Cilostazol, a selective type III phosphodiesterase inhibitor, is widely used for treatment of ischemic symptoms of peripheral vascular disease. Recent studies have reported that the mechanism of cilostazol is related to suppression of pro-inflammatory cytokine production and improvement of local microcirculation disturbances. The activation of inflammatory cells and pro-inflammatory cytokine production play critical roles in the pathogenesis of aspirin-induced gastric irritation. The aim of the present study was to determine whether cilostazol can ameliorate aspirin-induced gastric mucosal lesions in rats, reduce neutrophil accumulation, and reduce the production of pro-inflammatory cytokines. Gastric lesions were produced by oral gavage of aspirin (200 mg/kg) and HCl (0.15 N, 8.0 ml/kg). Cilostazol (1-10 mg/kg, IP) was injected 30 min before aspirin administration. Also, we measured the gastric mucosal concentrations of myeloperoxidase and interleukin-1 beta, tumor necrosis factor-alpha, and cytokine-induced neutrophil chemoattractants-1, as an index of neutrophil accumulation, and the pro-inflammatory cytokines. Cilostazol ameliorated the gastric mucosal lesions induced by aspirin administration (P<0.01). The gastric contents of myeloperoxidase and pro-inflammatory cytokines were all increased after aspirin administration and significantly reduced by cilostazol treatment. In this study, we demonstrated that a selective type III phosphodiesterase inhibitor, cilostazol, reduced aspirin-induced gastric inflammation and damage via suppression of the production of proinflammatory cytokines. Cilostazol may be useful for preventing gastric mucosal lesions induced by aspirin.

MEK activation suppresses CPT11-induced apoptosis in rat intestinal epithelial cells through a COX-2-dependent mechanism.

Resistance to chemotherapeutic agents is one of the distinct features of cancer cells. We evaluate the role of activated MEK-ERK signaling in Camptotecin/irinotecan (CPT-11)-induced cell death using constitutively activated MEK1-transfected normal rat intestinal epithelial cells (IEC-caMEK cells). A CPT-11-induced inhibitory concentration of 50% was determined by WST assay. Apoptosis was evaluated by DNA staining and fragmented DNA analysis. Protein expressions were analyzed by western blotting. We also examined the role of cyclooxygenase-2 in the cell systems. IEC-caMEK cells possessed survival advantages compared to control cells. Apoptosis was remarkably suppressed in IEC-caMEK cells. Western blot analysis revealed increased expression of Bcl-2, Bcl-xL, Mcl-1, and COX-2 and decreased expression of Bak in IEC-caMEK cells. The COX-2 selective inhibitor ameliorated the antiapoptotic nature of IEC-caMEK cells. MEK activation suppressed CPT-11-induced apoptosis in IEC-caMEK cells via a COX-2- dependent mechanism. Therefore, MEK-ERK signaling may contribute to the drug-resistant nature of cancer cells.

Mechanical strain stress suppresses expression of HSP70 and wound restoration in gastric mucosal cells.

The major heat shock protein, HSP70, is known to be involved in cytoprotection against environmental stresses mediated by their function as a "molecular chaperone." However, the influence of HSP70 on gastric mucosal healing under physical stimulation or stress is not completely understood. Rat gastric mucosal cells (RGM-1) were stably transfected with pBK-CMV containing the human HSP70 gene (7018-RGM-1) or pBK-CMV alone (pBK-CMV-12). Artificial wounds were created. Mechanical stretch was applied to 7018-RGM-1 cells or pBK-CMV-12 cells. The effect of mechanical stretch on HSP70 expression was assessed by Western blot analysis. Expression of HSP70 was decreased by mechanical stretch in pBK-CMV-12 cells. However, expression of HSP70 was not decreased by mechanical stretch in 7018-RGM-1 cells. Furthermore, the wound restoration of pBK-CMV-12 cells was suppressed under mechanical stretch condition. On the other hand, the wound restoration of 7018-RGM-1 cells was not affected by mechanical stretch. These results suggest that HSP70 plays an important role in gastric wound healing under physical stress.

Mitigation of stress-induced gastric mucosal lesions by a specific type IV phosphodiesterase inhibitor.

Inhibition of type IV phosphodiesterase (PDE4) activity is beneficial in various inflammations. However, the effect of phosphodiesterase inhibitors on the development of stress-induced gastric mucosal lesions has not been reported. In the present study, we examined the effect of a specific PDE4 inhibitor (rolipram) on stress-induced gastric mucosal lesions. Rats were exposed to water-immersion stress with or without pretreatment with rolipram. Ulcer index and myeloperoxidase activity of the gastric mucosa were evaluated. Gastric mucosal lesions and mucosal myeloperoxidase activity were suppressed by treatment with rolipram without acid suppression. The effect of intraperitoneal administration of 2.5 mg/kg rolipram on suppression of mucosal lesions was almost equal to that of treatment with 200 mg/kg cimetidine. We demonstrated that a specific PDE4 inhibitor has a potent anti-ulcer effect presumably mediated by an increment in intracellular cAMP in inflammatory cells, in which this enzyme is abundantly and specifically expressed.

Protective effect of a novel rice extract against ethanol-induced gastric mucosal injury in rat.

The aim of this study was to investigate the protective action of rice extract on ethanol-induced mucosal damage in vivo and wound healing of epithelial cells in vitro. Also, the effect of rice extract on gastric mucosal prostaglandin E(2) level, HSP72 expression, gastric acid secretion, and contribution of vanilloid receptor-mediated action was studied. In addition, using cultured gastric mucosal cells (RGM-1), the effect of rice extract on cytoprotection and wound healing of epithelial cells was evaluated. Rice extract significantly reduced gastric mucosal damage produced by ethanol in vivo, and heat treatment (80 degrees C, 3 min) of this agent did not alter its protective effect. Rice extract also protected RGM-1 from ethanol-induced damage in a dose-dependent manner. Rice extract accelerated wound healing of gastric epithelial cells. Our results demonstrate that rice extract could be an alternative ulcer treatment that provides cytoprotection and enhancement of wound healing not dependent on acid secretion, prostaglandin E(2) level, HSP72 expression, or vanilloid receptors.

The induction mechanism of the molecular chaperone HSP70 in the gastric mucosa by Geranylgeranylacetone (HSP-inducer).

To elucidate the induction mechanism of HSP70 by geranylgeranylacetone (GGA), we investigated GGA specific binding proteins using a GGA-affinity column. Alteration of chaperone activity of HSP70 and binding affinity of HSP70 to heat shock factor-1 (HSF-1) was evaluated in the presence or absence of GGA. The binding domain of HSP70 to GGA was also analyzed. A 70-kDa protein eluted by 10 mM GGA from the GGA-affinity column was identical to constitutively expressed HSP70 on immunoblotting. GGA-binding domain of HSP70 was C-terminal of the protein as peptide-binding domain (HSP70C). The chaperone activity of HSP70 and recombinant HSP70C was suppressed by GGA. Furthermore, dissociation of the HSP70 from HSF-1 was observed in the presence of GGA. GGA preferentially binds to the C-terminal of HSP70 which binds to HSF-1. After dissociation of HSP70, free HSF-1 could acquire the ability to bind to HSE (the promoter region of HSP70) gene.