Frequently abnormal serum gamma-glutamyl transferase activity is associated with future development of fatty liver: a retrospective cohort study.

BACKGROUND: Nonalcoholic fatty liver disease is characterized by excessive hepatic fat accumulation. Some individuals frequently present elevated gamma-glutamyl transferase (GGT) levels without fatty liver ultrasound images and other abnormal liver enzymes levels. However, whether these individuals are at an elevated risk for developing fatty liver is unclear. We compared fatty liver change rates and risk factors between individuals with frequently elevated GGT levels and those with normal levels. METHODS: We designed a retrospective cohort study on the basis of complete medical checkup records. One group of individuals had presented normal serum GGT levels during the observation period (Normal-GGT group, n = 2713). Another group had had abnormal elevated serum GGT levels frequently (Abnormal-GGT group, n = 264). We determined the fatty liver change incident rates before and after propensity score matching. We explored confounding factors affecting fatty changes in each group using univariate and multivariate Cox models. RESULTS: The change incidence rates were 5.80/1000 and 10.02/1000 person-years in the Normal-GGT and Abnormal-GGT groups, respectively. After propensity score matching, the incidence rates were 3.08/1000 and 10.18/1000 person-years in the Normal-GGT and Abnormal-GGT groups, respectively (p = 0.026). The factors associated with fatty liver changes in the Normal-GGT group included body mass index (BMI), hemoglobin, alanine aminotransferase (ALT), albumin, triglyceride (TG), fasting blood sugar, and high-density lipoprotein levels. Those in the Abnormal-GGT group were platelet counts and TG. In our multivariable analysis, BMI, ALT, albumin, and TG levels were independent predictors of fatty changes in the Normal-GGT group, and high TG level was the only independent predictor in the Abnormal-GGT group. CONCLUSIONS: The incidence rate of fatty liver change in the Abnormal-GGT group was higher than that in the Normal-GGT group. Consecutive elevated GGT levels increase the risk for fatty liver, and high TG levels in those individuals further independently increase the risk.

Impact of Helicobacter pylori eradication on circulating adiponectin in humans.

BACKGROUND: The relationship between Helicobacter pylori infection and metabolic syndrome is not well understood. Adiponectin is an adipose-derived protein considered to play a significant role in the development of metabolic syndrome. The aim of this study was to clarify the influence of H. pylori infection on circulating adiponectin in humans. METHODS: In a prospective study, 456 patients underwent endoscopy and H. pylori testing. All of the 338 H. pylori -positive patients received eradication therapy. Treatment was successful in 241 patients. Circulating adiponectin and other metabolic parameters were measured at baseline in all patients and 12 weeks after eradication therapy in those initially positive for H. pylori. RESULTS: Circulating adiponectin levels were not different between H. pylori -positive and H. pylori -negative patients. In the group with successful eradication, levels of total adiponectin and each multimer form were significantly increased after therapy. Conversely, the levels of total adiponectin and high-molecular-weight adiponectin, but not middle-molecular-weight and low-molecular-weight adiponectin, were increased in the group with unsuccessful eradication after the therapy. CONCLUSIONS: Eradication therapy of H. pylori increased circulating adiponectin levels in Japanese individuals and could be beneficial for preventing metabolic syndrome conditions.

A case of inoperable duodenal cancer achieving long-term survival after multidisciplinary treatment.

A 50-year-old female became aware of skin yellowing and consulted another hospital where she was diagnosed intraoperatively with duodenal cancer because of lymph node metastases around the aorta. Endoscopy revealed type IIa + IIc cancer distal to the duodenal papilla, and biopsy allowed a diagnosis of well-differentiated adenocarcinoma. Computed tomography revealed a large number of lymph node metastases around the aorta and in the left supraclavicular cavity. The patient was given many regimens of chemotherapy, mainly containing S-1, and multidisciplinary treatment, and achieved long-term survival for 6 years and 1 month. This is a valuable case suggesting the usefulness of this therapeutic approach. In view of the fact that duodenal cancer is a relatively rare disease and the possibility that the incidence of this disease may increase in the future, it seems essential to collect additional data from multicenter prospective studies towards the goal of establishing a standard method of treatment for this disease.

Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells.

Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic acid-induced small intestinal apoptosis, a hallmark of acetylsalicylic acid-induced enteropathy.

Oxidative stress-induced posttranslational modification of TRPV1 expressed in esophageal epithelial cells.

Human esophageal epithelium is continuously exposed to physical stimuli or to gastric acid that sometimes causes inflammation of the mucosa. Transient receptor potential vanilloid 1 (TRPV1) is a nociceptive, Ca(2+)-selective ion channel activated by capsaicin, heat, and protons. It has been reported that activation of TRPV1 expressed in esophageal mucosa is involved in gastroesophageal reflux disease (GERD) or in nonerosive GERD symptoms. In this study, we examined the expression and function of TRPV1 in the human esophageal epithelial cell line Het1A, focusing in particular on the role of oxidative stress. Interleukin-8 (IL-8) secreted by Het1A cells upon stimulation by capsaicin or acid with/without 4-hydroxy-2-nonenal (HNE) was measured by ELISA. Following capsaicin stimulation, the intracellular production of reactive oxygen species (ROS) was determined using a redox-sensitive fluorogenic probe, and ROS- and HNE-modified proteins were determined by Western blotting using biotinylated cysteine and anti-HNE antibody, respectively. HNE modification of TRPV1 proteins was further investigated by immunoprecipitation after treatment with synthetic HNE. Capsaicin and acid induced IL-8 production in Het1A cells, and this production was diminished by antagonists of TRPV1. Capsaicin also significantly increased the production of intracellular ROS and ROS- or HNE-modified proteins in Het1A cells. Moreover, IL-8 production in capsaicin-stimulated Het1A cells was enhanced by synthetic HNE treatment. Immunoprecipitation studies revealed that TRPV1 was modified by HNE in synthetic HNE-stimulated Het1A cells. We concluded that TRPV1 functions in chemokine production in esophageal epithelial cells, and this function may be regulated by ROS via posttranslational modification of TRPV1.

Reactive oxygen species-quenching and anti-apoptotic effect of polaprezinc on indomethacin-induced small intestinal epithelial cell injury.

BACKGROUND: To protect the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs is one of the critical issues in the field of gastroenterology. Polaprezinc (PZ), a gastric muco-protecting agent, has been widely used for the treatment of gastric ulcer and gastritis for its unique effects, such as its strong reactive oxygen species (ROS)-quenching effect. The aim of this study was to clarify the mechanism by which indomethacin-induced small intestinal mucosal injury occurs, by using a rat intestinal epithelial cell line (RIE-1). In addition, the protective role of PZ and the possible mechanism of its effect on indomethacin-induced small intestinal injury were investigated. METHODS: Cell death was evaluated by methyl thiazolyl tetrazolium (MTT) assay and a double-staining method with Hoechst33342 dye and propidium iodide. Indomethacin-induced ROS production was evaluated by detecting the oxidation of a redox-sensitive fluorogenic probe, RedoxSensor, and the oxidation of cysteine residues of proteins (protein S oxidation). The activation of cytochrome c, smac/DIABLO, and caspase-3 was assessed by western blotting. In some experiments, PZ or its components, L: -carnosine and zinc, were used. RESULTS: We found that indomethacin caused apoptosis in RIE-1 cells in a dose- and time-dependent manner. Indomethacin also induced ROS production and an increase in the protein S oxidation of RIE-1. Pretreatment of RIE-1 with PZ or zinc sulfate, but not L: -carnosine, significantly reduced the indomethacin-induced apoptosis. PZ prevented ROS production and the increase in protein S-oxidation. PZ inhibited indomethacin-induced cytochrome c and smac/DIABLO release and subsequent caspase-3 activation. CONCLUSIONS: The protective effect of PZ on indomethacin-induced small intestinal injury may be dependent on its ROS-quenching effect.

Heat-shock protein 70-overexpressing gastric epithelial cells are resistant to indomethacin-induced apoptosis.

BACKGROUND/AIMS: Protecting intestinal mucosa from nonsteroidal anti-inflammatory drugs is still an unsolved problem. It has been revealed that apoptosis in epithelial cells as a result of mitochondrial injury is an important pathogenesis in indomethacin-induced gastric mucosal injury. In this study, we revealed the effect of overexpressed heat-shock protein 70 (HSP70) in indomethacin-induced apoptosis and oxidative stress. METHODS: HSP70-overexpressing rat gastric mucosal cells (7018-RGM-1 cells) and control cells (pBK-CMV-12 cells) were used and treated with 0-500 microM of indomethacin for 24 h. Cell viability and cytotoxity were measured by a WST-8 assay and a lactate dehydrogenase release assay, respectively. Apoptosis was observed by fluorescence microscopy staining with Hoechst 33342 and propidium iodide. The expression of Bcl-2 family proteins, activation of caspase-3, and 4-hydroxy-2-nonenal (4-HNE)-modified proteins were assessed by Western blot analysis. RESULTS: Indomethacin caused apoptosis of gastric epithelial cells. The 7018-RGM-1 cells survived significantly after indomethacin treatment compared to the control cells. The increase in pro-apoptotic Bad proteins, the decrease in anti-apoptotic Bcl-2 proteins, and caspase activation were all suppressed in the 7018-RGM-1 cells. A lower level of indomethacin-induced 4-HNE-modification was detected in the 7018-RGM-1 cells than in the control cells. CONCLUSION: Overexpressed HSP70 may potentiate resistance to apoptosis and oxidative stress in indomethacin-induced gastric epithelial cell injury.

Involvement of reactive oxygen species in indomethacin-induced apoptosis of small intestinal epithelial cells.

BACKGROUND: The precise pathogenic mechanism of nonsteroidal antiinflammatory drug-induced small intestinal injury is still unknown. In the present study, we investigated the mechanism by which indomethacin induced mucosal injury by using an in vitro model of small intestine. METHODS: The colon cancer cell line Caco-2, exhibiting a small intestinal phenotype starting as a crypt cell and differentiating to a villous phenotype, and RIE, a rat intestinal epithelial cell line, were employed. Indomethacin was added to differentiated the Caco-2 and RIE monolayer, and cell death was quantified by MTT assay and LDH release in the cell culture supernatant. Indomethacin-induced cell death was also qualified by fluorescent probes under the fluorescent microscope. As a functional study, the permeability of the Caco-2 monolayer was assessed by measuring transepithelial electrical resistance (TEER) and the flux of FITC-conjugated dextran across the monolayer. Indomethacin-induced reactive oxygen species production in Caco-2 and RIE was evaluated by redoxsensitive fluorogenic probes using a fluorometer. In some experiments, antioxidants were used to clarify the role of reactive oxygen species on indomethacin-induced Caco-2 cell death. RESULTS: Indomethacin caused cell death (mainly apoptosis) of Caco-2 and RIE in a dose-and time-dependent manner that was correlated with increased permeability of the Caco-2 monolayer. Exposure of Caco-2 and RIE with indomethacin also resulted in a significant reactive oxygen species production that was inhibited by the pretreatment of these cells with antioxidants. CONCLUSIONS: Taken together, reactive oxygen species production is one of the mechanisms by which indomethacin induced small intestinal injury.