Lack of Association between Epidermal Growth Factor or Its Receptor and Reflux Esophagitis, Barrett's Esophagus, and Esophageal Adenocarcinoma: A Case-Control Study.

The epidermal growth factor (EGF) and its receptor (EGFR) gene-gene interactions were shown to increase the susceptibility to esophageal cancer. However, the role of the EGF/EGFR pathway in the development of gastroesophageal reflux disease (GERD) and its complications (reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC)) remains unclear. This association study is aimed at investigating functional EGF and EGFR gene polymorphisms, their mRNA expression in esophageal tissues, and EGF plasma levels in relation to RE, BE, and EAC development in the Central European population. 301 patients with RE/BE/EAC (cases) as well as 98 patients with nonerosive reflux disease (NERD) and 8 healthy individuals (controls) were genotyped for +61 A>G EGF (rs4444903) and +142285 G>A EGFR (rs2227983) polymorphisms using the TaqMan quantitative polymerase chain reaction (qPCR). In random subgroups, the EGF and EGFR mRNA expressions were analyzed by reverse transcription qPCR in esophageal tissue with and without endoscopically visible pathological changes; and the EGF plasma levels were determined by enzyme-linked immunosorbent assay. None of the genotyped SNPs nor EGF-EGFR genotype interactions were associated with RE, BE, or EAC development (p > 0.05). Moreover, mRNA expression of neither EGF nor EGFR differed between samples of the esophageal tissue with and without endoscopically visible pathology (p > 0.05) nor between samples from patients with different diagnoses, i.e., RE, BE, or EAC (p > 0.05). Nevertheless, the lower EGF mRNA expression in carriers of combined genotypes AA +61 EGF (rs4444903) and GG +142285 EGFR (rs2227983; p < 0.05) suggests a possible direct/indirect effect of EGF-EGFR gene interactions on EGF gene expression. In conclusion, EGF and EGFR gene variants and their mRNA/protein expression were not associated with RE, BE or EAC development in the Central European population.

Cost-Utility Analysis of CYP2C19 Genotype Detection for Selection of Acid-Suppressive Therapy with Lansoprazole or Vonoprazan for Patients with Reflux Esophagitis in China.

BACKGROUND: The cytochrome P450 (CYP) 2C19 genotype has a profound effect on the efficacy of lansoprazole, with less of an influence on vonoprazan. Both are first-choice drugs for the treatment of reflux esophagitis in China. OBJECTIVE: We aimed to estimate the cost-effectiveness of acid-suppressive treatments in Chinese patients with reflux esophagitis over 1 year from the societal perspective. METHODS: We developed a decision-based Markov model with a 4-week cycle to simulate the economic benefits and quality-adjusted life-years between different treatment strategies for patients with reflux esophagitis: universal lansoprazole, universal vonoprazan, and CYP2C19 genotype-guided strategies. The primary outcome was the incremental cost-effectiveness ratio. Data sources were the published literature, clinical trials, documents, and local charges. We used sensitivity analyses to detect the robustness of the findings and explored subgroup analyses and scenario analyses to make further evaluations. RESULTS: Compared to lansoprazole, vonoprazan and the CYP2C19 genotype-guided strategy were not preferable for Chinese patients with reflux esophagitis, with an incremental cost-effectiveness ratio of 222,387.1316 yuan/quality-adjusted life-year and 349,627.5000 yuan/quality-adjusted life-year, respectively. Sensitivity analyses showed the impact factors were the utility scores and the expenditures for the maintenance stage with lansoprazole and vonoprazan. When the willingness-to-pay threshold was 215,484 yuan/quality-adjusted life-year, 46.20% of the reflux esophagitis population was willing to pay for vonoprazan, compared with 8.30% for the CYP2C19 genotype-guided strategies. Vonoprazan and the CYP2C19 genotype-guided strategy were cost effective in the severe reflux esophagitis population, and in the reduction of the price of vonoprazan. CONCLUSIONS: The health economic evaluations revealed that for Chinese patients with reflux esophagitis, vonoprazan and the CYP2C19 genotype-guided strategy were not cost-effective regimens compared with lansoprazole. However, we found that in certain conditions like a reduction in the price of vonoprazan and in patients with severe reflux esophagitis these could be cost-effective.

Pathophysiology of reflux oesophagitis: role of Toll-like receptors 2 and 4 and Farnesoid X receptor.

The pathogenesis of gastroesophageal reflux disease (GERD) is not fully understood. It involves the activation of mucosal immune-mediated and inflammatory responses. Toll-like receptors (TLR) 2 and TLR4 are pattern-recognition receptors of the innate immune system; they recognize microbial and endogenous ligands. Farnesoid X receptor (FXR) is a bile acid receptor that regulates the inflammatory response. We aimed to evaluate TLR2, TLR4 and FXR expression patterns in GERD. We re-evaluated 84 oesophageal biopsy samples according to the global severity (GS) score, including 26 cases with histologically normal oesophagus, 28 with histologically mild oesophagitis and 30 with severe oesophagitis. We used immunohistochemistry and in situ hybridization to assess the expression patterns of TLR2, TLR4 and FXR in oesophageal squamous cells. Immunohistochemistry showed that nuclear and cytoplasmic TLR2 was expressed predominantly in the basal layer of normal oesophageal epithelium. In oesophagitis, TLR2 expression increased throughout the epithelium, and the superficial expression was significantly more intensive compared to normal epithelium, p <0.01. Nuclear and cytoplasmic TLR4 was expressed throughout the thickness of squamous epithelium, with no change in oesophagitis. FXR was expressed in the nuclei of squamous cells, and the intensity of the expression increased significantly in oesophagitis (p <0.05). FXR expression correlated with basal TLR2. In situ hybridization confirmed the immunohistochemical expression patterns of TLR2 and TLR4. In GERD, TLR2, but not TLR4, expression was upregulated which indicates that innate immunity is activated according to a specific pattern in GERD. FXR expression was increased in GERD and might have a regulatory connection to TLR2.

A Novel Susceptibility Locus Near GRIK2 Associated With Erosive Esophagitis in a Korean Cohort.

INTRODUCTION: The male-predominant sex difference through the spectrum of erosive esophagitis to Barrett's esophagus is widely known. We conducted a genome-wide association study (GWAS) stratified by sex for identifying factors that can predict the endoscopically diagnosed erosive esophagitis. METHODS: Erosive esophagitis was diagnosed by endoscopy and assessed for severity. We identified genetic factors associated with erosive esophagitis that accounted for the sex differences in a cohort of 4,242 participants via a GWAS. After quality control and imputation, genetic associations with erosive esophagitis were investigated by multivariate linear regression in 3,620 subjects. Single-nucleotide polymorphisms (SNPs) with P < 5.0 × 10 were considered significant genome wide, and a genetic risk score was constructed for the prediction of erosive esophagitis risk. RESULTS: Six genome-wide significant SNPs near the GRIK2 gene on chromosome 6 were found to be associated with erosive esophagitis only in male subjects. These were predictive of severity through a genetic risk score (P < 0.05), and the findings were validated in a cohort of 622 subjects (P < 0.05). DISCUSSION: This is the first GWAS of erosive esophagitis, and we identified 6 genome-wide significant SNPs in male subjects. These SNPs could help explain the pathogenesis of erosive esophagitis and contribute to the understanding of sex differences. Further genetic investigation could allow for the prediction of high risk for erosive esophagitis and development of new treatment options.

Changes in Clock Genes Expression in Esophagus in Rat Reflux Esophagitis.

BACKGROUND: Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances. Clock genes harmonize circadian rhythms by their periodic expression and regulate several physiological functions. However, the association between clock genes and GERD is still unknown. AIMS: We investigated whether reflux esophagitis affects circadian variability of clock genes in the esophagus and other organs using a rat reflux esophagitis model. METHODS: Reflux esophagitis was induced in 7-week-old male Wistar rats. Sham-operated rats were used as controls. Rats were killed at 09:00 (light period) and 21:00 (dark period) 3 days (acute phase) and 21 days (chronic phase) after induction of esophagitis. The expression levels of clock gene mRNAs such as Per1, Per2, Per3, Cry1, Cry2, Arntl, and Clock in the esophagus were investigated by qPCR. Arntl expression was examined in stomach, small intestine, colon, and liver tissues. Serum melatonin and IL-6 levels were measured by ELISA. RESULTS: Histological examination of reflux esophagitis mainly revealed epithelial defects with marked inflammatory cell infiltration in the acute phase and mucosal thickening with basal cell hyperplasia in the chronic phase. Circadian variability of clock genes, except Cry1, was present in the normal esophagus and was completely disrupted in reflux esophagitis during the acute phase. The circadian variability of Per2, Per3, and Arntl returned to normal, but disruption of Per1, Cry2, and Clock was present in the chronic phase. Disruption of circadian variability of Arntl was observed in the esophagus, as well as in the stomach, small intestine, and liver tissues in reflux esophagitis during the acute phase. There were no significant differences in serum melatonin and IL-6 levels between control and reflux esophagitis animals in both acute and chronic phases. CONCLUSIONS: Disruption to circadian variability of clock genes may play a role in the pathogenesis of GERD.

RNA sequencing confirms similarities between PPI-responsive oesophageal eosinophilia and eosinophilic oesophagitis.

BACKGROUND: Although current American guidelines distinguish proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) from eosinophilic oesophagitis (EoE), these entities are broadly similar. While two microarray studies showed that they have similar transcriptomes, more extensive RNA sequencing studies have not been done previously. AIM: To determine whether RNA sequencing identifies genetic markers distinguishing PPI-REE from EoE. METHODS: We retrospectively examined 13 PPI-REE and 14 EoE biopsies, matched for tissue eosinophil content, and 14 normal controls. Patients and controls were not PPI-treated at the time of biopsy. We did RNA sequencing on formalin-fixed, paraffin-embedded tissue, with differential expression confirmation by quantitative polymerase chain reaction (PCR). We validated the use of formalin-fixed, paraffin-embedded vs RNAlater-preserved tissue, and compared our formalin-fixed, paraffin-embedded EoE results to a prior EoE study. RESULTS: By RNA sequencing, no genes were differentially expressed between the EoE and PPI-REE groups at the false discovery rate (FDR) ≤0.01 level. Compared to normal controls, 1996 genes were differentially expressed in the PPI-REE group and 1306 genes in the EoE group. By less stringent criteria, only MAPK8IP2 was differentially expressed between PPI-REE and EoE (FDR = 0.029, 2.2-fold less in EoE than in PPI-REE), with similar results by PCR. KCNJ2, which was differentially expressed in a prior study, was similar in the EoE and PPI-REE groups by both RNA sequencing and real-time PCR. CONCLUSION: Eosinophilic oesophagitis and PPI-REE have comparable transcriptomes, confirming that they are part of the same disease continuum.

Comparison of Tight Junction Protein-Related Gene mRNA Expression Levels between Male and Female Gastroesophageal Reflux Disease Patients.

Background/Aims: Male predominance has been observed in the erosive reflux disease (ERD), but reverse finding in nonerosive reflux disease (NERD). This suggests sex-specific medicine approach is needed but its mechanism is remained to be elucidated. We aimed to compare clinical characteristics and mRNA expression levels of tight junction-related proteins between male and female gastroesophageal reflux disease (GERD). Methods: Sixteen healthy controls, 45 ERD, and 14 NERD patients received upper endoscopies and completed questionnaires. Quantitative real-time polymerase chain reactions of occludin (OCLN), zonal occludens (ZO) 1, claudin-1 (CLDN1) and claudin-4 (CLDN4), and neurokinin 1 receptor (NK1R) were performed in the distal esophageal mucosal specimen. These results were analyzed by sex. Results: Female GERD patients were affected more by reflux symptoms than males. The impairment of overall quality of life was more prominent in female patients with reflux symptoms than male patients (5.6±0.2 vs 4.9±0.6, p=0.009). The levels of OCLN mRNA expression were significantly lower in the male ERD group. On the other hand, those of CLDN1, CLDN4, and NK1R except ZO-1 were significantly higher in the male ERD group. Conclusions: We demonstrated that female ERD/NERD patients were affected more by GERD and male ERD patients showed significant changes of tight junction protein mRNA expression levels.

Low-Molecular-Weight Oligonol, a Polyphenol Derived from Lychee Fruit, Attenuates Experimental Reflux Esophagitis and HCl/Ethanol-Induced Gastric Ulcer.

Oligonol, a polyphenol derived from lychee fruit, is produced by an oligomerization process that converts high-molecular-weight polyphenol polymers into low-molecular-weight oligomers. Evidence suggests that oligonol exerts its beneficial effects based on antioxidant and anti-inflammatory properties. This study was the first to investigate the antioxidative and anti-inflammatory effects of oligonol on gastroesophageal inflammatory models: surgically induced acute reflux esophagitis (RE) and gastric ulcer (GU) induced by HCl/ethanol. In the in vitro study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical scavenging assays were performed to determine the antioxidant activity of oligonol. The experimental groups were each composed of normal, vehicle, and oligonol groups. RE rats and GU mice were treated orally with oligonol (100 mg/kg bw) or distilled water as a vehicle (n = 8 for each group). Oligonol exhibited potent free radical-scavenging capacities for DPPH and ABTS radicals, activities that were similar to those of ascorbic acid. The in vivo study revealed that oligonol consumption significantly prevented RE and GU formation and decreased the gross mucosal injury from oxidative stress. Oligonol decreased the reactive oxygen species levels and elevated levels of both inflammatory mediators and cytokines (p-IκB, NF-κBp65, COX-2, iNOS, TNF-α, and IL-1ß) in the RE and GU models. Oligonol had a protective effect against oxidative stress by regulating antioxidant enzyme (superoxide dismutase, catalase, and GPx-1/2) activities in GU mice. Oligonol has potential as a preventive and therapeutic agent for gastroesophageal inflammatory diseases, including RE and GU.

Expression of Serum Exosomal and Esophageal MicroRNA in Rat Reflux Esophagitis.

Gastroesophageal reflux disease (GERD) is a common upper gastrointestinal disease. However, the role of exosomal microRNAs (miRNAs) and esophageal miRNAs in GERD has not been studied. A rat model of acid reflux esophagitis was used to establish a novel diagnosis marker for GERD and examine dynamics of miRNA expression in GERD. Rats were sacrificed 3 (acute phase), 7 (sub-acute phase) and 21 days (chronic phase) after induction of esophagitis. Exosomes were extracted from serum, and the expression patterns of serum miRNAs were analyzed. Four upregulated miRNAs (miR-29a-3p, 128-3p, 223-3p and 3473) were identified by microarray analysis. The expression levels of exosomal miR-29a-3p were significantly higher in the chronic phase of reflux esophagitis compared with controls, and increased expression of miR-29a-3p was specific to chronic reflux esophagitis. Esophageal miR-223-3p expression was higher compared with controls, and gradually decreased from acute to chronic phase in esophagitis. In conclusion, exosomal miR-29a-3p and esophageal miR-223-3p might play roles in GERD.

Exploration of the Esophageal Mucosal Barrier in Non-Erosive Reflux Disease.

In the absence of visible mucosal damage, it is hypothesized that the esophageal mucosal barrier is functionally impaired in patients with non-erosive reflux disease (NERD). The aim of the present study was to perform an exploratory analysis of the mucosal barrier in NERD compared to erosive esophagitis (EE) and controls. A second aim was to explore TRPV1 gene transcription in relation to the mucosal barrier function and heartburn symptoms. In this prospective study, 10 NERD patients, 11 patients with active erosive esophagitis and 10 healthy volunteers were included. Biopsies from non-eroded mucosa were obtained for (1) ex vivo analyses (Ussing chamber) of transepithelial electrical resistance (TEER) and permeability (2) gene transcription of tight-junction proteins and transient receptor potential vanilloid subfamily member 1 (TRPV1). No differences in TEER or permeability were found between NERD and healthy volunteers, whereas TEER was lower in patients with erosive esophagitis. TRPV1 gene transcription was not significantly different between EE, NERD and controls. CONCLUSIONS: esophageal mucosal barrier function and TRPV1 transcription is not significantly altered in NERD patients. Future research is needed to explore other potential mechanisms that may account for the high symptom burden in these patients.

Reflux esophagitis and its role in the pathogenesis of Barrett's metaplasia.

Reflux esophagitis damages the squamous epithelium that normally lines the esophagus, and promotes replacement of the damaged squamous lining by the intestinal metaplasia of Barrett's esophagus, the precursor of esophageal adenocarcinoma. Therefore, to prevent the development of Barrett's metaplasia and esophageal adenocarcinoma, the pathogenesis of reflux esophagitis must be understood. We have reported that reflux esophagitis, both in a rat model and in humans, develops as a cytokine-mediated inflammatory injury (i.e., cytokine sizzle), not as a caustic chemical injury (i.e., acid burn), as traditionally has been assumed. Moreover, reflux induces activation of hypoxia inducible factor (HIF)-2α, which enhances the transcriptional activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) causing increases in pro-inflammatory cytokines and in migration of T lymphocytes, an underlying molecular mechanism for this cytokine-mediated injury. In some individuals, reflux esophagitis heals with Barrett's metaplasia. A number of possibilities exist for the origin of the progenitor cells that give rise to this intestinal metaplasia including those of the esophagus, the proximal stomach, or the bone marrow. However, intestinal cells are not normally found in the esophagus, the stomach, or the bone marrow. Thus, the development of Barrett's intestinal metaplasia must involve some molecular reprogramming of key developmental transcription factors within the progenitor cell, a process termed transcommitment, which may be initiated by the noxious components of the gastric refluxate. This review will highlight recent studies on the pathogenesis of reflux esophagitis and on reflux-related molecular reprogramming of esophageal squamous epithelial cells in the pathogenesis of Barrett's metaplasia.

Factors associated with residual gastroesophageal reflux disease symptoms in patients receiving proton pump inhibitor maintenance therapy.

AIM: To elucidate the factors associated with residual gastroesophageal reflux disease (GERD) symptoms in patients receiving proton pump inhibitor (PPI) maintenance therapy in clinical practice. METHODS: The study included 39 GERD patients receiving maintenance PPI therapy. Residual symptoms were assessed using the Frequency Scale for Symptoms of GERD (FSSG) questionnaire and the Gastrointestinal Symptom Rating Scale (GSRS). The relationships between the FSSG score and patient background factors, including the CYP2C19 genotype, were analyzed. RESULTS: The FSSG scores ranged from 1 to 28 points (median score: 7.5 points), and 19 patients (48.7%) had a score of 8 points or more. The patients' GSRS scores were significantly correlated with their FSSG scores (correlation coefficient = 0.47, P < 0.005). In erosive esophagitis patients, the FSSG scores of the CYP2C19 rapid metabolizers (RMs) were significantly higher than the scores of the poor metabolizers and intermediate metabolizers (total scores: 16.7 ± 8.6 vs 7.8 ± 5.4, P < 0.05; acid reflux-related symptom scores: 12 ± 1.9 vs 2.5 ± 0.8, P < 0.005). In contrast, the FSSG scores of the CYP2C19 RMs in the non-erosive reflux disease patients were significantly lower than those of the other patients (total scores: 5.5 ± 1.0 vs 11.8 ± 6.3, P < 0.05; dysmotility symptom-related scores: 1.0 ± 0.4 vs 6.0 ± 0.8, P < 0.01). CONCLUSION: Approximately half of the GERD patients receiving maintenance PPI therapy had residual symptoms associated with a lower quality of life, and the CYP2C19 genotype appeared to be associated with these residual symptoms.

Toll-like Receptor 2 Signalling and the Lysosomal Machinery in Barrett's Esophagus.

BACKGROUND AND AIMS: Inflammation plays an important role in the development of esophageal adenocarcinoma and its metaplastic precursor lesion, Barrett's esophagus. Toll-like receptor (TLR) 2 signalling and lysosomal function have been linked to inflammation-associated carcinogenesis. We examined the expression of TLR2 in the esophagus and the effect of long-term TLR2 activation on morphological changes and expression of factors involved in lysosomal function in a Barrett's esophagus epithelium cell line. METHODS: TLR2 expression in normal squamous esophagus, reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma biopsies was assessed with Q-RT-PCR, in situ hybridization and immunohistochemistry. Barrett's esophagus epithelium cells (BAR-T) were incubated with acid and bile salts in the presence or absence of the TLR2 agonist Pam3CSK4 for a period up to 4 weeks. Morphological changes were assessed with electron microscopy, while Q-RT-PCR was used to determine the expression of lysosomal enzymes (Cathepsin B and C) and factors involved in endocytosis (LAMP-1 and M6PR) and autophagy (LC3 and Rab7). RESULTS: TLR2 was expressed in normal squamous esophagus, reflux esophagitis, Barrett's esophagus but was most prominent in esophageal adenocarcinoma. Long-term TLR2 activation in acid and bile salts exposed BAR-T cells resulted in more and larger lysosomes, more mitochondria and increased expression of LAMP-1, M6PR, Cathepsin B and C when compared to BAR-T cells incubated with acid and bile salts but no TLR2 agonist. Factors associated with autophagy (LC3 and Rab7) expression remained largely unchanged. CONCLUSION: Activation of TLR2 in acid and bile salts exposed Barrett epithelium cells resulted in an increased number of mitochondria and lysosomes and increased expression of lysosomal enzymes and factors involved in endocytosis.

The effect of n-3/n-6 polyunsaturated fatty acids on acute reflux esophagitis in rats.

BACKGROUND: Polyunsaturated fatty acids (PUFAs) play various roles in inflammation. However, the effect of PUFAs in the development of reflux esophagitis (RE) is unclear. This study is to investigate the potential effect of n-3/n-6 PUFAs on acute RE in rats along with the underlying protective mechanisms. METHODS: Forty Sprague Dawley rats were randomly divided into four groups (n = 10 in each group). RE model was established by pyloric clip and section ligation. Fish oil- and soybean oil-based fatty emulsion (n-3 and n-6 groups), or normal saline (control and sham operation groups) was injected intraperitoneally 2 h prior to surgery and 24 h postoperatively (2 mL/kg, respectively). The expressions of interleukin (IL)-1ß, IL-8, IL-6 and myeloid differentiation primary response gene 88 (MyD88) in esophageal tissues were evaluated by Western blot and immunohistochemistry after 72 h. The malondialdehyde (MDA) and superoxide dismutase (SOD) expression in the esophageal tissues were determined to assess the oxidative stress. RESULTS: The mildest macroscopic/microscopic esophagitis was found in the n-3 group (P < 0.05). The expression of IL-1ß, IL-8, IL-6 and MyD88 were increased in all RE groups, while the lowest and highest expression were found in n-3 and n-6 group, respectively (P < 0.05). The MDA levels were increased in all groups (P < 0.05), in an ascending trend from n-3, n-6 groups to control group. The lowest and highest SOD levels were found in the control and n-3 group, respectively (P < 0.05). CONCLUSION: n-3 PUFAs may reduce acute RE in rats, which may be due to inhibition of the MyD88-NF-kB pathway and limit oxidative damage.

Decreased n-6/n-3 polyunsaturated fatty acid ratio reduces chronic reflux esophagitis in rats.

AIM: To investigate the effect of dietary ratio of n-6/n-3 PUFAs on chronic reflux esophagitis (RE) and lipid peroxidation. METHOD: Rat RE model were established and then fed on a diet contained different n-6/n-3 PUFA ratios (1:1.5, 5:1, 10:1) or received pure n-6 PUFA diet for 14 days. Esophageal pathological changes were evaluated using macroscopic examination and hematoxyline-eosin staining. IL-1ß, IL-8, and TNFα mRNA and protein levels of were determined using RT-PCR and Western blotting, respectively. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined using ELISA. RESULTS: The severity of esophagitis was lowest in the PUFA(1:1.5) group (P<0.05). IL-1ß, IL-8, and TNFα mRNA and protein and MDA levels were significantly increased in model groups with the increasing n-6/n-3 PUFA ratios. SOD levels were significantly decreased in all RE PUFA groups (P<0.05). CONCLUSION: Esophageal injury and lipid peroxidation appeared to be ameliorated by increased n-3 PUFAs intake.

Rapid metabolizer genotype of CYP2C19 is a risk factor of being refractory to proton pump inhibitor therapy for reflux esophagitis.

BACKGROUND: Proton pump inhibitors (PPIs) are mainly metabolized by cytochrome P450 2C19 (CYP2C19) and used as the first-line therapy for gastroesophageal reflux disease (GERD). However, while several studies have examined the influence of CYP2C19 polymorphism on GERD treatment with PPIs, most have had small sample sizes and were conducted in a single center. Here, we used meta-analysis to investigate whether or not the CYP2C19 rapid metabolizer (RM) genotype is a risk factor for GERD patients being refractory to PPI therapy. METHODS: PubMed and other electronic databases were systematically searched up to August 2014 using the following terms: "GERD and CYP2C19", "esophagitis and CYP2C19", and "non-erosive reflux disease and CYP2C19." Searches were limited to publications in English, and two investigators evaluated eligible studies and extracted data. RESULTS: The total efficacy rate of PPIs for GERD, including reflux esophagitis (RE) and non-erosive reflux disease, was 56.4% (95% confidence interval [CI]; 53.9-58.9%, 870/1543) in intention-to-treat analysis and 63.8% (95%CI; 61.3-66.2%, 950/1489) in per-protocol analysis. Efficacy rates varied significantly between CYP2C19 genotypes (intention-to-treat analysis: RMs, 52.2% [315/604]; intermediate metabolizers, 56.7% [298/526]; poor metabolizers [PMs], 61.3% [138/225]; P = 0.047). Among RE patients, CYP2C19 RMs had an increased risk of being refractory to PPI therapy compared with PMs (odds ratio: 1.661, 95% CI: 1.023-2.659, P = 0.040). CONCLUSIONS: The present meta-analysis demonstrates that CYP2C19 RMs with RE have an increased risk of being refractory to PPI therapy compared with PMs. Individualized dosing regimen with PPIs based on CYP2C19 genotype might be a valid therapeutic strategy for overcoming insufficient gastric acid inhibition.

[POLYMORPHISM OF GLUTHATIONE-S-TRANSFERASE P1 IN CHILDREN WITH REFLUX-ESOPHAGITIS].

The distribution of allele and genotype frequencies of genes of xenobiotic detoxication (CYP2E1--PstI, RsaI, DraI; ADH, ALDH, NAT2, GSTP1, GSTM1, GSTT1) was examined in 147 patients with reflux-esophagitis (RE) and 50 conditionally healthy children 12-18 years. The frequency of AA genotype of GSTP1 gene and A allele was significantly higher in patients with RE as compared with healthy children (χ2 = 4.93; P = 0.03 and χ2 = 5.94; P = 0.01 respectively).

Genetic polymorphisms of CYP2C19 and IL1B have no influence on esomeprazole treatment for mild erosive esophagitis.

Interleukin (IL)-1ß is a potent inhibitor of gastric acid secretion and its genetic polymorphism is linked to the severity of reflux esophagitis. Proton-pump inhibitor (PPI) metabolized by P450 2C19 (CYP2C19) is the chief medication in reflux esophagitis treatment. The CYP2C19 genotype may influence the therapeutic effect of PPI for reflux esophagitis. From November 2009 to June 2012, 184 patients were enrolled in this study with endoscopy examination, 8 weeks of esomeprazole treatment, and 20 weeks of follow-up with questionnaire. These patients also received endoscopy examination after 20 weeks. Blood was collected for genetic polymorphism analysis with polymerase chain reaction. After 8 weeks of treatment with esomeprazole, all of these 184 patients had achieved complete symptom relief. However, in the following 12 weeks, 58.70% (108/184) complained of symptom relapse, 45.65% (84/184) patients had persistent esophageal erosion verified by endoscopy, and in total, 76.09% (140/184) patients had treatment failure at the end of 20 weeks. There were no influences between the genetic polymorphisms of CYP2C19 and IL1B to treatment failure (p = 0.896). Therefore, prolonging PPI treatment and further lifestyle modification might be warranted for symptomatic mild esophagitis. There were no relationships between IL-1ß and CYP2C19 in the treatment effect in mild reflux esophagitis.

Esophageal Helicobacter pylori colonization aggravates esophageal injury caused by reflux.

AIM: To investigate esophageal Helicobacter pylori (H. pylori) colonization on esophageal injury caused by reflux and the related mechanisms. METHODS: An esophagitis model, with acid and bile reflux, was surgically produced in male rats. The rats were randomly divided into either: (1) an esophagogastroduodenal anastomosis (EGDA) group; (2) an EGDA with H. pylori infection group; (3) a pseudo-operation with H. pylori infection group; or (4) a pseudo-operation group. All rats were kept for 36 wk. Based on the location of H. pylori colonization, the EGDA rats with H. pylori infection were subdivided into those with concomitant esophageal H. pylori colonization or those with only gastric H. pylori colonization. The esophageal injuries were evaluated grossly and microscopically. The expressions of CDX2 and MUC2 were determined by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. Ki-67 antigen expression was determined by immunohistochemistry. The mRNA levels of cyclin D1, c-Myc, Bax and Bcl-2 were determined by RT-PCR. Cell apoptosis was evaluated using the TdT-mediated dUTP nick-end labeling method. RESULTS: Esophagitis, Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) developed in rats that underwent EGDA. When comparing rats with EGDA and concomitant esophageal H. pylori colonization to EGDA-only rats, the severity of injury (87.9 ± 5.2 vs 77.2 ± 8.6, macroscopically, 92.5 ± 8.0 vs 83.8 ± 5.5, microscopically, both P < 0.05) and the incidences of BE (80.0% vs 33.3%, P = 0.055) and EAC (60.0% vs 11.1%, P < 0.05) were increased. These increases were associated with upregulation of CDX2 and MUC2 mRNA (10.1 ± 5.4 vs 3.0 ± 2.9, 8.4 ± 4.6 vs 2.0 ± 3.2, respectively, Ps < 0.01) and protein (8.1 ± 2.3 vs 3.3 ± 3.1, 7.3 ± 4.0 vs 1.8 ± 2.7, respectively, all P < 0.05). The expression of Ki-67 (8.9 ± 0.7 vs 6.0 ± 1.7, P < 0.01) and the presence of apoptotic cells (8.3 ± 1.1 vs 5.3 ± 1.7, P < 0.01) were also increased significantly in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only. The mRNA levels of cyclin D1 (5.8 ± 1.9 vs 3.4 ± 1.3, P < 0.01), c-Myc (6.4 ± 1.7 vs 3.7 ± 1.2, P < 0.01), and Bax (8.6 ± 1.6 vs 5.1 ± 1.3, P < 0.01) were significantly increased, whereas the mRNA level of Bcl-2 (0.6 ± 0.3 vs 0.8 ± 0.3, P < 0.01) was significantly reduced in rats with EGDA and concomitant esophageal H. pylori colonization compared with rats with EGDA only. CONCLUSION: Esophageal H. pylori colonization increases esophagitis severity, and facilitates the development of BE and EAC with the augmentation of cell proliferation and apoptosis in esophageal mucosa.

Dickkopf-1, the Wnt antagonist, is induced by acidic pH and mediates epithelial cellular senescence in human reflux esophagitis.

Squamous esophageal epithelium adapts to acid reflux-mediated injury by proliferation and differentiation via signal transduction pathways. Induction of the Wnt antagonist Dickkopf-1 (Dkk1) is involved in tissue repair during inflammation and cellular injury. In this study, we aimed to identify the biological role of Dkk1 in human reflux esophagitis with respect to cell growth and regulation of Wnt signaling. Esophageal biopsies from reflux-esophagitis patients (n = 15) and healthy individuals (n = 10) were characterized in terms of Dkk1 expression. The role of Dkk1 in response to acid-mediated epithelial injury was analyzed by cellular assays in vitro utilizing squamous esophageal epithelial cell lines (EPC1-hTERT, EPC2-hTERT, and HEEC). Dkk1 was significantly overexpressed in human reflux-esophagitis tissue compared with healthy esophageal mucosa at transcriptional and translational levels. After acute and chronic acid (pH 4) exposure, esophageal squamous epithelial cell lines expressed and secreted high levels of Dkk1 in response to stress-associated DNA injury. High extracellular levels of human recombinant Dkk1 inhibited epithelial cell growth and induced cellular senescence in vitro, as demonstrated by reduced cell proliferation, G0/G1 cell cycle arrest, elevated senescence-associated ß-galactosidase activity, and upregulation of p16. Acid pulsing induced Dkk1-mediated senescence, which was directly linked to the ability of Dkk1 to antagonize the canonical Wnt/ß-catenin signaling. In healthy esophageal mucosa, Dkk1 expression was associated with low expression of transcriptionally active ß-catenin, while in reflux-esophagitis tissue, Dkk1 overexpression correlated with increased senescence-associated ß-galactosidase activity and p16 upregulation. The data indicate that, in human reflux esophagitis, Dkk1 functions as a secreted growth inhibitor by suppressing Wnt/ß-catenin signaling and promoting cellular senescence. These findings suggest a significant role for Dkk1 and cellular senescence in esophageal tissue homeostasis during reflux esophagitis.