Mitsuo Nagasaka

The Influence of Polymorphisms of Interleukin-17A and Interleukin-17F Genes on the Susceptibility to Ulcerative Colitis

We investigated the association between ulcerative colitis (UC) and polymorphisms of IL-17A (rs2275913, G-197A) and IL-17F (rs763780, 7488T/C) genes. We employed the multiplex PCR-SSCP method to detect gene polymorphisms. Both the numbers of -197A (IL-17A) and 7488T (IL-17F) alleles were significantly correlated to the development of UC. The frequencies of -197A/A and 7488T/T genotypes in the UC group were significantly higher than those in the non-UC group. An adjusted analysis revealed that -197A and 7488T alleles were independent risk factors for the developing UC. In addition, both polymorphisms were significantly associated with the pancolitis phenotype. Furthermore, -197A allele was significantly correlated to the chronic relapsing phenotype and -197A/A homozygote was more frequent in steroid-dependent cases, whereas 7488T allele was correlated with the chronic continuous phenotype. Our results provided the first evidence that -197A (IL-17A) and 7488T (IL-17F) alleles may influence the susceptibility to and pathophysiological features of UC independently.

Association Study of Common Genetic Variants in Pre-microRNAs in Patients with Ulcerative Colitis

BackgroundCommon single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of ulcerative colitis (UC) in a Japanese population.MethodsThe rs11614913 (T > C), rs2910164 (C > G), and rs3746444 (A > G) SNPs were genotyped in 170 UC and 403 control subjects.ResultsThe rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR) = 1.51, 95% CI = 1.03–2.21, p = 0.037). The rs3746444 AG genotype was associated with onset at an older age (OR = 1.70, 95% CI = 1.04–2.78, p = 0.035), left-sided colitis and pancolitis (left-sided colitis, OR = 2.10, 95% CI = 1.12–3.94, p = 0.024; pancolitis, OR = 1.81, 95% CI = 1.09–3.01, p = 0.028, left-sided colitis + pancolitis, OR = 1.91, 95% CI = 1.26–2.92, p = 0.003), higher number of times hospitalized (OR = 2.63, 95% CI = 1.22–5.69, p = 0.017), steroid dependence (OR = 2.63, 95% CI = 1.27–5.44, p = 0.014), and refractory phenotypes (OR = 2.76, 95% CI = 1.46–5.21, p = 0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR = 0.36, 95% CI = 0.17–0.79, p = 0.012), steroid dependence (OR = 0.42, 95% CI = 0.21–0.88, p = 0.021), and refractory phenotypes (OR = 0.38, 95% CI = 0.20–0.72, p = 0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C + C/C, OR = 2.21, 95% CI = 1.17–4.18, p = 0.016).ConclusionsOur results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.

Selenoprotein S (SEPS1) gene -105G>A promoter polymorphism influences the susceptibility to gastric cancer in the Japanese population

BackgroundInflammation is a key factor in the process of carcinogenesis from chronic gastritis induced by Helicobacter pylori. Selenoprotein S (SEPS1) is involved in the control of the inflammatory response in the endoplasmic reticulum (ER). Recently the -105G>A polymorphism in the promoter of SEPS1 was shown to increase pro-inflammatory cytokine expression. We examined the association between this polymorphism and the risk of gastric cancer.MethodsWe took stomach biopsies during endoscopies of 268 Japanese gastric cancer patients (193 males and 75 females, average age 65.3), and 306 control patients (184 males and 122 females, average age 62.7) and extracted the DNA from the biopsy specimens. All subjects provided written informed consent. For the genotyping of the SEPS1 promoter polymorphism at position -105G>A, PCR-RFLP methods were used and the PCR products were digested with PspGI.Logistic-regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for age, sex, and H. pylori infection status.ResultsAmong cases, the distribution of genotypes was as follows: 88.4% were GG, 11.2% were GA, and 0.4% were AA. Among controls, the distribution was as follows: 92.5% were GG, 7.2% were GA, and 0.3% were AA. Among males, carrying the A allele was associated with an increased odds of gastric cancer, compared with the GG genotype (OR: 2.0, 95% CI 1.0–4.1, p = 0.07). Compared with the GG genotype, carrying the A allele was significantly associated with increased risks of intestinal type gastric cancer (OR: 2.0, 95%CI 1.0–3.9, p < 0.05) as well as of gastric cancer located in the middle third of the stomach (OR: 2.0, 95%CI 1.0–3.9, p < 0.05).ConclusionThe -105G>A promoter polymorphism of SEPS1 was associated with the intestinal type of gastric cancer. This polymorphism may influence the inflammatory conditions of gastric mucosa. Larger population-based studies are needed for clarifying the relation between inflammatory responses and SEPS1 polymorphism.

A Polymorphism of microRNA 27a Genome Region Is Associated With the Development of Gastric Mucosal Atrophy in Japanese Male Subjects

Noncoding microRNAs regulate the expression of various mRNAs. We attempted to clarify the relationship between miR-27a genome polymorphism and chronic gastritis. The study was performed in 179 patients with no evidence of gastric malignancy. The severity of histologic chronic gastritis was classified according to the updated Sydney system. The frequency of miR-27a G allele was 34.6%. Although the frequencies of miR-27a G allele were increased in subjects with peptic ulcer or severe mucosal atrophy, no significant differences were seen. The miR-27a polymorphism showed an interaction with gender in relation to gastric mucosal atrophy (P=.090). In only male subjects, the miR-27a polymorphism was associated with the gastric mucosal atrophy (P=.039) and both atrophy and metaplasia scores in G/G group were significantly higher than those in the other groups. The miR-27a genome region polymorphism may be an important definitive factor to develop the gastric mucosal atrophy in Japanese male subjects.

Risk prediction of gastric cancer by analysis of aberrant DNA methylation in non-neoplastic gastric epithelium.

Background: Aberrant DNA methylation is one of the major events in carcinogenesis. Promoter DNA methylation is also present in various non-neoplastic tissues including gastric epithelium as age-related phenomenon, suggesting that it occurs early in the process of tumorigenesis. Aim: We aimed to clarify the relationship of aberrant DNA methylation in non-neoplastic gastric epithelia with the risk of gastric cancer, Helicobactor pylori infection, and the degree of H. pylori-induced gastritis. Methods: 89 patients enrolled in this study. The status of aberrant DNA methylation was compared in two groups of patients: 43 cases with gastric cancer (mean age 65.9 years [29–91], F:M = 0.30, intestinal type [n = 25], diffuse type [n = 18]) and 46 age- and sex-matched patients without gastric cancer (peptic ulcer diseases [n = 11], gastritis [n = 35]) as a control group. Genomic DNA was extracted directly from non-neoplastic epithelia of antral biopsies obtained by endoscopy. The promoter methylation status of the p14 and p21 genes was determined by methylation-specific-polymerase chain reaction (MSP). The promoter methylation status of the p16 gene was quantified by digital densitographic analysis following MSP. The degree of gastritis in the antrum was assessed according to the updated Sydney system. The PG I/II ratio was calculated based on the data of serum PG I and PG II levels measured by radioimmunoassay. Results: In all 89 subjects, CpG island methylation was found in 25.8% for p14, 52.8% for p16, 1.1% for p21. Among non-cancer patients, the methylation frequency of the p14 gene was significantly higher in H. pylori-positive than in H. pylori-negative patients (38.5 vs. 10.0%, p = 0.03). The mean (± SD) methylation levels of the p16 gene in non-neoplastic gastric epithelium was significantly higher in gastric cancer cases both in all patients and in H. pylori-positive patients (0.45 ± 0.31 vs. 0.20 ± 0.17; p = 0.019, 0.45 ± 0.31 vs. 0.20 ± 0.17; p = 0.016, respectively). The methylation level of the p16 gene was also associated with the presence of intestinal-type gastric cancer (p = 0.017). The methylation level of the p16 gene was significantly higher in patients with intestinal metaplasia (IM) than those without (p = 0.04). Furthermore, the methylation level of the p16 gene was correlated with lower PG l/ll ratio (p = 0.04). The methylation of the p21gene was found in only 1 patient with gastric cancer. Conclusions: Our data suggest that promoter of the p14 gene may be one of the specific regions whose methylation is closely associated with H. pylori infection. Methylation levels of the p16 gene seem to be accumulated in the progression of gastric mucosal atrophy and IM, and thus may be associated with the presence of gastric cancer especially for intestinal-type histopathology.

Genetic polymorphisms of CD14 and Toll-like receptor-2 (TLR2) in patients with ulcerative colitis

Background and Aim:  Ulcerative colitis (UC) is a multifactorial disease resulting from a complex interaction of genetic and environmental factors. Identifying genetic variants that alter the innate immune response is highly relevant to understanding the pathogenesis of UC. The aim of this study was to investigate the association between CD14 and Toll‐like receptor‐2 (TLR2) genetic polymorphisms and chronic UC in Japanese patients.

Effect of concurrent elemental diet on infliximab treatment for Crohn’s disease

Background:  Infliximab and elemental diet (ED) have been shown to be effective in the management of Crohn’s disease. However, few experiences have been reported regarding their combination therapy. The aim of the present study was to investigate the efficacy and safety of infliximab in Japanese patients, the first such study in Asia, as well as the effect of concomitant ED.

Increased number of methylated CpG islands correlates with Helicobacter pylori infection, histological and serological severity of chronic gastritis.

Background Promoter hypermethylation of tumor suppressor genes is one of the major events in gastric carcinogenesis. Promoter hypermethylation is also present in non-neoplastic gastric epithelium as age-related phenomenon and some reports suggest the potential association between promoter hypermethylation and Helicobacter pylori infection. Here, we examined whether methylation of multiple promoter CpG islands would occur by H. pylori infection and correlate with histological or serological severity of chronic gastritis. Methods One hundred and ninety-one gastric mucosa samples were obtained by endoscopy. The promoter methylation status of the p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific-polymerase chain reaction. The degree of gastritis in the antrum was assessed according to the updated Sydney system in 150 participants. The pepsinogen (PG) I/II ratio was calculated based on the data of serum PG I and PG II levels measured by radioimmunoassay in 54 selected cases. Results CpG island methylation was found in 32.5% for p14, 35.1% for p16, 43.5% for DAP-kinase and 36.1% for CDH1, whereas non, 1, 2, 3, and all methylation of four promoter CpG sites were present in 46 (24.1%), 59 (30.9%), 46 (24.1%), 30 (15.7%), and 10 (5.2%) participants, respectively. A strong association between the increased number of methylated CpG islands and H. pylori infection was observed (P<0.0001). An increased number of methylated CpG islands was also associated with severity of neutrophil infiltration (P<0.0001), mononuclear cell infiltration (P<0.0001) and atrophy (P=0.0021) in all, and severity of neutrophil infiltration (P=0.0177) and mononuclear cell infiltration (P=0.0004) in H. pylori-positive participants. An increased number of methylated CpG islands correlated with lower PG I/II ratio in all (P=0.0105) and H. pylori-infected participants (P=0.074). Conclusion Multiple promoter CpG islands would be methylated by H. pylori infection, and an increased number of methylated CpG sites correlate with histological and serological severity of chronic gastritis.

Genetic polymorphisms of cyclooxygenase-1 (COX-1) are associated with functional dyspepsia in Japanese women.

BACKGROUND Prostaglandins (PGs), catalyzed from arachidonic acid by cyclooxygenase (COX), are involved in a variety of physiological processes in the stomach. COX-1 has been regarded as a constitutively expressed enzyme that generates prostaglandins for gastrointestinal integrity. We investigated the association between the potentially functional polymorphism T-1676C in the COX-1 gene promoter and functional dyspepsia (FD) in the Japanese population. METHODS The study was performed in 272 subjects (185 with no upper abdominal symptoms and 87 with FD). We employed the PCR-SSCP method to detect the gene polymorphism. RESULTS Overall, female sex had a 2-2.5-fold risk for the development of FD compared with male sex, whereas the COX-1 gene polymorphism and Helicobacter pylori infection were not associated with susceptibility to FD. However, in female subjects, -1676T allele carriers had a significantly increased risk for the development of FD (OR 2.70, 95%CI 1.04-6.99, p = 0.041), especially the epigastric pain syndrome (EPS) subgroup (OR 4.07, 95%CI 1.15-14.4, p = 0.029). CONCLUSIONS Our results provide the first evidence that the COX-1 gene polymorphism is significantly associated with the development of the EPS subgroup of FD in female subjects.

Correlation between magnifying narrow band imaging and histopathology in gastric protruding/or polypoid lesions: a pilot feasibility trial

BackgroundSeveral study showed usefulness of microscopic capillaries, seen by magnifying narrow band imaging (NBI) endoscopy for predicting histopathology among superficial depressed or flat elevated gastric neoplasia (GN). Here we assessed the diagnostic efficacy of magnifying NBI for predicting histopathology among gastric protruding/or polypoid lesions.MethodsUsing endoscopic pictures of magnifying NBI from 95 protruding/or polypoid lesions (19 fundic gland polyps: FGP, 47 hyperplastic polyps: HP, and 29 GN), fine mucosal patterns were classified into four categories: small round, prolonged, villous or ridge, and unclear patterns, and micro vascular patterns were classified into five categories: honey comb, dense vascular, fine net work, core vascular, and unclear patterns.ResultsMost suggestive micro vascular patterns for predicting FGP, and HP were honeycomb (sensitivity 94.7%, specificity 97.4%), and dense vascular patterns (sensitivity 93.6%, specificity 91.6%), respectively. Fine net work, core vascular, and unclear patterns presented higher specificity (97%, 100%, and 100%) for predicting GN, and diagnostic efficacy of combined of those patterns was favorable (sensitivity 86.2%, specificity 97.0%).ConclusionMicro vascular patterns by using magnifying NBI provides meaningful information for predicting the histopathology of gastric protruding/or polypoid lesions.