Mi Kyoung Lee

The Effects of Genetic Polymorphisms of il-6 , il-8 , and il-10 on helicobacter pylori- induced Gastroduodenal Diseases in Korea

Background The genes that encode proinflammatory and anti-inflammatory cytokines are good candidate markers of host susceptibility to gastroduodenal disease. The present study was performed to evaluate whether or not the genetic polymorphisms of IL-6, IL-8, and IL-10 are associated with gastroduodenal disease in the Korean population. Methods This study enrolled 1187 patients, including controls, those with gastric cancer (GC), benign gastric ulcer (BGU), and duodenal ulcer patients. Six polymorphisms were genotyped, 3 of IL-10 (at −592, −819, and −1082), 1 of IL-8 (at −251), and 2 of IL-6 (at −174 and −572), by polymerase chain reaction-restriction fragment length polymorphism analysis. Results The frequency of IL-10-1082 G carriers was higher in cases of a diffuse type GC [odds ratio (OR) 1.8, 95% confidence interval (CI): 1.0-3.1, P=0.041] or BGU (OR 1.6, 95% CI: 1.0-2.5, P=0.040), than in the control group regardless of Helicobacter pylori infection. The IL-8-251 A/A genotype was more common in H. pylori-positive patients with GC (OR 2.0, 95% CI: 1.2-3.6, P=0.013) or BGU (OR 2.7, 95% CI: 1.5-4.8, P=0.001) than in H. pylori-positive controls. In addition, the frequencies of IL-6-572 G/G (OR 0.3, 95% CI: 0.1-0.9, P=0.027) and of G carriers (OR 0.5, 95% CI: 0.4-0.8, P=0.003) were lower in H. pylori-positive duodenal ulcer patients than in H. pylori-positive controls. IL-10-592 C/C (OR 0.4, 95% CI: 0.2-0.9, P=0.028) was an independent factor associated with a decreased risk of the intestinal type of GC by multivariate analysis. Furthermore, a synergistic effect was observed between IL-10-592 A/A and IL-8-251 A/A with respect to the development of GC or BGU. Conclusions These results suggest that the genetic polymorphisms of these 3 inflammation-related cytokines, IL-10, IL-8, and IL-6, are associated with the development of H. pylori-associated gastroduodenal disease.

Change in antibiotic resistance of Helicobacter pylori strains and the effect of A2143G point mutation of 23S rRNA on the eradication of H. pylori in a single center of Korea.

Background The current prevalence of primary antibiotic resistance of H. pylori is not known in Korea. This study was done to evaluate the prevalence of primary antibiotic resistance of H. pylori, and to evaluate the effect of point mutations of 23S rRNA on the rate of eradication of H. pylori. Methods H. pylori were isolated from gastric mucosal biopsy specimens obtained from 222 Koreans. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin were examined using the agar dilution method. DNA sequencing was carried out to detect H. pylori 23S rRNA mutations. Results The resistance to clarithromycin, tetracycline, ciprofloxacin, and levofloxacin increased during the period of 2007 to 2009 compared with 2003 to 2005 (P<0.05). However, amoxicillin and metronidazole resistance slightly decreased. The rates of eradication were 95.5% for the clarithromycin-sensitive strains, which was higher than the 67.9% for the clarithromycin-resistant strains (P=0.001). By contrast, the eradication rate was 100% in patients with amoxicillin-resistant H. pylori. Among 26 clarithromyin-resistant strains, 6 (23%) had A2143G mutations, and all of the cases in which these mutations were present were not eradicated by proton pump inhibitor-based triple therapy (P=0.0004). By contrast, none of the 26 clarithromyin-sensitive strains had A2143G mutations. The T2183C and A2223G mutations were frequently found in the sensitive strains and in the resistant strains. Conclusions Clarithromycin resistance of H. pylori, which determined the efficacy of H. pylori eradication of proton pump inhibitor triple regimen, was found to be increased in a single center study. A2143G was an important 23S rRNA mutation associated with clarithromycin resistance and affected the H. pylori eradication efficacy.

Effect of aging on gastric mucosal defense mechanisms: ROS, apoptosis, angiogenesis, and sensory neurons.

Aging changes in the stomach lead to a decreased capacity for tissue repair in response to gastric acid. The aim of this study was to determine the mechanism associated with the increased susceptibility to injury of aging mucosa including reactive oxygen species (5), apoptosis, angiogenesis, and sensory neuron activity. Fischer 344 rats at four different ages (6, 31, 74 wk, and 2 yr of age) were studied. The connective tissue indicators [salt-soluble collagen and sulfated glycosaminoglycan (sGAG)], lipid hydroperoxide (LPO), myeloperoxidase (MPO), and hexosamine were assessed. We also evaluated the expression of early growth response-1 (Egr-1), phosphatase and tension homologue deleted on chromosome 10 (PTEN), caspase-9 (index of apoptosis), VEGF (index of angiogenesis), calcitonin gene-related peptide (CGRP, index of sensory neurons), and neuronal nitric oxide synthase (nNOS). The histological connective tissue area in the lower part of rat gastric mucosa increased with aging, with increase of salt-soluble collagen and sGAG. LPO and MPO in old rats were significantly greater than in the young rats, whereas hexosamine was significantly reduced. The old gastric mucosa had increased expression of Egr-1, PTEN, and caspase-9, whereas the VEGF, CGRP, and nNOS expression were significantly reduced. These results indicate that the lower part of rat gastric mucosa was found to be replaced by connective tissue with accumulation of oxidative products with aging. In addition, impairment of apoptosis, angiogenesis, and sensory neuron activity via the activation of Egr-1 and PTEN might increase the susceptibility of gastric mucosa to injury during aging.

Enhancement of Gastric Ulcer Healing and Angiogenesis by Cochinchina Momordica Seed Extract in Rats

Cochinchina momordica seed is the dried ripe seed of Momordica cochinchinensis, a perennial vine. The antiulcer effect of an extract from cochinchina momordica seeds (SK-MS10) was evaluated in a rat model of acetic acid-induced gastric ulcers. Gastric ulcers were produced by subserosal injection of acetic acid. SK-MS10 (200 mg/kg) or vehicle was administered orally once per day for 14 days after the acetic acid injection. The stomach was removed and the ulcer size measured at day 7 and 14 of the treatment. Expression of vascular endothelial growth factor (VEGF) was assessed by real-time RT-PCR and Western blot analysis. In addition, the microvasculature density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry. The treatment with SK-MS10 for 7 and 14 days significantly accelerated ulcer healing and increased the expression of mRNA (at day 7) as well as VEGF protein (at day 14) compared to the vehicle-treated rats. The MVD for factor VIII was also higher in the SK-MS10 treatment group compared to the vehicle-treated rats; however, these differences were not statistically significant. These results suggest that SK-MS10 treatment accelerates the healing of gastric ulcers via upregulation of VEGF and angiogenesis in an acetic acid rat model.

Anti-gastric cancer effects of celecoxib, a selective COX-2 inhibitor, through inhibition of Akt signaling.

Background and Aim:  Previously, we showed that treatment with celecoxib significantly reduced the number of viable gastric cancer cells, in a dose‐ and time‐dependent manner. However, the specific anti‐cancer effects of celecoxib on gastric cancer cells have not been clarified. The present in vitro study was carried out to investigate the mechanism involved in the anti‐gastric cancer effects of celecoxib.

Comparison of Indomethacin, Diclofenac and Aspirin-Induced Gastric Damage according to Age in Rats

Background/Aims Aging gastric mucosa is known to have decreased mucosal defenses and increased susceptibility to injury by nonsteroidal anti-inflammatory drugs. Depending on the type of nonsteroidal anti-inflammatory drug (NSAID), the underlying mechanisms and the extent of damage to the stomach or intestine may differ. This study was performed to evaluate the acute gastric damage caused by different doses of indomethacin, diclofenac and aspirin in rats of various ages. Methods For the acute models, indomethacin (10, 20 or 40 mg/kg), diclofenac (40 or 80 mg/kg) or aspirin (100 mg/kg) was given to 7- and 25-week-old and 1-year-old Sprague-Dawley rats by intragastric gavage. The gross ulcer index, damage area as assessed by imaging, histological index, myeloperoxidase (MPO) activity, and cytosolic phospholipase A2 (cPLA2) levels were measured after 24 hours. Results The gross ulcer index and damage area increased with age in the presence of three NSAIDs (p<0.05). The increases in MPO levels induced by diclofenac and aspirin were significantly higher in 1-year-old than 7-week-old rats (p<0.05). cPLA2 expression induced by indomethacin (10 and 40 mg/kg) was greater in the 1-year-old rats, compared with 7-week-old rats (p<0.05). Conclusions NSAID-induced acute gastric damage increased in a dose- and age-dependent manner.

Helicobacter pylori genotyping findings from multiple cultured isolates and mucosal biopsy specimens: strain diversities of Helicobacter pylori isolates in individual hosts

Objectives To determine whether the genotypes of virulent genes in Helicobacter pylori isolates and mucosal biopsy specimens differ in individuals, and to investigate whether different isolates from single hosts show strain differences. Methods Sixty-one Korean patients with H. pylori infection were enrolled. PCR and DNA sequencing for cagA, vacA, iceA, and oipA were performed using DNA extracted from H. pylori isolates cultured (2.6 H. pylori isolates per host) directly from antral mucosal biopsy specimens. Strain diversities were analyzed in 234 H. pylori isolates obtained from 43 hosts with at least two H. pylori isolates from antrum and body, respectively, and random amplified polymorphic DNA fingerprinting was carried out on isolates obtained from patients who showed genotype diversity. Results The patients with inconsistent genotyping results between H. pylori isolates and mucosal biopsies were as follows: 16.4% for cagA, 19.7% for vacA m, 47.5% for vacA s1, 6.6% for vacA i-region, 34.4% for iceA, and 21.3% for oipA. Genotyping of H. pylori isolates from same hosts showed diversity in 58.1% (25/43 patients). When random amplified polymorphic DNA -PCR fingerprinting was carried out on 104 H. pylori isolates from 19 patients who showed genotype diversity among their isolates, 68.4% (13 of 19 patients) of patients were found to be colonized by multiple H. pylori strains. Conclusion This study shows that the genotypes of virulent genes from biopsy samples produced different results when compared with those obtained from H. pylori isolates, especially for vacA s1, and iceA. In addition, about 60% of our patients were infected by multiple H. pylori strains.

The interleukin-8-251 AA genotype is associated with angiogenesis in gastric carcinogenesis in Helicobacter pylori-infected Koreans.

Helicobacter pylori (H. pylori) is an important risk factor of gastric adenocarcinoma. Interleukin (IL)-8 is a potent angiogenic factor and plays an important role in inflammation of gastric mucosa by H. pylori. Host susceptibility may help to predict H. pylori-infected individuals with a higher risk of gastric adenocarcinoma. The aim of this study was to clarify the effect of IL-8 polymorphism on angiogenesis in the process of gastric carcinogenesis in H. pylori-infected Koreans. The IL-8-251A/T polymorphism was genotyped by PCR-RFLP from a total of 395 subjects; 92 normal controls, 87 H. pylori-infected controls, 108 chronic atrophic gastritis and/or intestinal metaplasia and 108 adenocarcinoma. The gastric mucosal concentrations of IL-8, membrane metalloproteinase (MMP)-9, angiopoietin (Ang)-1, and vascular endothelial growth factor (VEGF) were measured by ELISA. MMP-9 concentrations were increased with disease progression. There was significant correlation between MMP-9 and disease progression in AA (r=0.42, p<0.01) and AT genotype (r=0.43, p<0.01). Ang-1 concentrations were increased in AA genotype (r=0.40, p=0.01). However, there was no significant correlation between VEGF and disease progression in AA genotype. In conclusion, IL-8-251 AA genotype may be associated with angiogenesis in gastric carcinogenesis in H. pylori-infected Koreans.

Probiotic suppression of the H. pylori-induced responses by conjugated linoleic acids in a gastric epithelial cell line

Conjugated linoleic acids (CLA) produced by Lactobacillus acidophilus was reported to decrease the activation of nuclear factor-kappa B. CLA was suggested as one of the anti-inflammatory molecular mechanisms of probiotics. In the present study, the effects of CLA on H. pylori-induced multiple responses were evaluated. IL-8, TNF-α and iNOS were measured in mRNA and/or protein levels in AGS cells after pretreatment with CLA or CLA-containing conditioned medium (CM) produced by Lactobacillus acidophilus or Lactobacillus plantarum. The increased expressions of IL-8 mRNA/protein and TNF-α mRNA were significantly suppressed by pretreatment with CM or CLA. The levels of IL-8 protein and TNF-α mRNA were suppressed by CM pretreatment better than CLA. The expression of iNOS mRNA was also significantly inhibited by CM pretreatment. These results suggest that the suppression of multiple mediators by CLA-containing CM plays a key role in the anti-inflammatory and anti-carcinogenic effects of probiotics on H. pylori infection.

Su1698 Comparison of Ten-Day, Fifteen-Day Sequential Therapy and Proton-Pump Inhibitor-Based Triple Therapy in Korea: A Prospective Randomized Study

Introduction: Helicobacter pylori (H. pylori) infection affects about 30-50% of adults in developed countries and causes persistent gastric infection and chronic inflammation. H. pylori infection is a major cause of gastric ulcer disease and gastric cancer. Diagnostic tests include histology, rapid urease test (RUT), breath tests and stool antigen tests. Previously, we have introduced a new electrochemical device for rapid H. pylori detection. Aims: To prospectively evaluate the newly developed electrochemical device for H. pylori detection in the clinical setting. Material & Methods: Seventy consecutive patients (43 female, 27 male; mean age 65 years, range 26-85 years) were included. The electrochemical device for H. pylori detection consists of a working and reference electrode between which a biopsy sample was administered. Acquired voltage-values between both electrodes were analysed for characteristics typical forH. pylori infection (ammonia). According to Sydney classification, biopsies were taken from gastric antrum and corpus for electrochemical H. pylori detection, RUT and immunohistochemistry (IHC). RUT results were evaluated after 24 hours. Every patient received 13C-urea breath test. Detection rates for H. pylori were analysed blinded to IHC results, which was designated as the gold standard of H. pylori diagnosis. Results: IHC had a sensitivity, specificity and accuracy of 100%. RUT analysis and 13C-urea breath test received both a sensitivity of 100% and a specificity of 92% and 95%, respectively. Accuracy of RUT was 93% and 96% for 13C-urea breath test. The new electrochemical H. pylori detection method showed a sensitivity of 100%, specificity of 94% and accuracy of 94%, respectively. Definitive results for H. pylori detection with the new device were available within 10 seconds. Conclusion: The new developed electrochemical H. pylori detection method allows rapid and accurate detection of the infection and has therefore the potential to improve H. pylori diagnosis and treatment.