Genetic Polymorphism in Alcohol Metabolism and Drinking Behavior are Associated with Gastric Cancer Risk in Men.

Objective In recent years, there has been a growing focus on health risks associated with alcohol consumption. The present study investigated whether or not the genetic variant of aldehyde dehydrogenase 2 (ALDH2) influences the risk of gastric cancer among individuals identified as hazardous drinkers using the Alcohol Use Disorders Identification Test (AUDIT), which provides a comprehensive assessment of hazardous drinking behavior. Patients We enrolled men with hazardous drinking behavior (AUDIT score ≥ 8) who had undergone gastric cancer screening (either endoscopy or a barium X-ray examination of the upper gastrointestinal tract) between April 2013 and March 2020 within 1 year from entry and who had subsequently undergone at least one more gastric cancer screening up to March 2021. Functional single-nucleotide polymorphisms of ALDH2 (rs671) were measured using a direct TaqMan PCR method with unprocessed saliva. Results A total of 246 men were enrolled, comprising 193 individuals with active ALDH2 (ALDH2*1/*1) and 53 with less-active ALDH2 (ALDH2*1/*2). The cumulative incidence of gastric cancer in the less-active group was higher than in the active ALDH2 group (p=0.01, hazard ratio: 4.6, 95% confidence interval: 1.2-16.7). Alcohol consumption was lower in the less-active ALDH2 group than in the active ALDH2 group, although no marked difference was observed in the AUDIT score. Conclusion In individuals with hazardous drinking behavior, a heightened risk of gastric cancer was observed among those with less-active ALDH2 variants, even when their alcohol consumption was comparatively lower than in those with active ALDH2 variants.

The Impact of Duodenal Mucosal Vulnerability in the Development of Epigastric Pain Syndrome in Functional Dyspepsia.

An unidentified cause of functional dyspepsia (FD) is closely associated with medication resistance. Acid suppression is a traditional and preferential method for the treatment of FD, but the efficacy of this treatment varies between epigastric pain syndrome (EPS) and postprandial syndrome (PDS): it is efficient in the former but not much in the latter. Transepithelial electrical resistance (TEER), a surrogate of mucosal barrier function, was measured under pH 3 and pH 5 acidic conditions using duodenal biopsy specimens obtained from the patients with EPS and PDS and asymptomatic healthy controls. The infiltration of inflammatory cells to the duodenal mucosa was accessed by immunohistochemical analysis. The duodenal mucosal TEER in EPS patients was decreased by exposure to the acidic solution compared to that of the controls and the PDS patients. The decrease in TEER of the EPS patients was observed even under pH 5 weak acidic condition and was correlated to degree of the epigastric pain. Moreover, the duodenal mucosa of EPS patients presented an increase in mast cells and plasma cells that expressed Ig-E. Duodenal mucosal vulnerability to acid is likely to develop EPS.

Decreased Expression of NRF2 Target Genes after Alcohol Exposure in the Background Esophageal Mucosa of Patients with Esophageal Squamous Cell Carcinoma.

Patients with esophageal squamous cell carcinoma (ESCC) might have a specific mechanism for the carcinogenesis by alcohol consumption in the background esophageal mucosa, and nuclear factor erythroid 2-related factor 2 (NRF2), which plays a protective role against esophageal carcinogenesis, and barrier dysfunction might be associated with this phenomenon. This study aimed to confirm this hypothesis. Twenty patients with superficial ESCCs (ESCC patients) and 20 age- and sex-matched patients without ESCC (non-ESCC patients) were enrolled. Biopsy samples were obtained from non-neoplastic esophageal mucosa: one for histological evaluation, one for quantitative real-time polymerase chain reaction (PCR), and two for the mini-Ussing chamber system to measure transepithelial electrical resistance (TEER) and, thereafter, for PCR. The TEER after acetaldehyde or both acetaldehyde and ethanol exposure did not differ significantly between ESCC and non-ESCC patients. Unlike non-ESCC patients, mRNA levels of NRF2 target genes and claudin4 in ESCC patients tended to decrease after the exposure, with a significant difference between no exposure and both acetaldehyde and ethanol exposure in NRF2 target genes (p < 0.05). Furthermore, in ESCC patients, the decreased tendency of mRNA levels of NRF2 target genes after the exposure was more pronounced in high-risk states, such as aldehyde dehydrogenase 2 (ALDH2) Lys alleles (Glu/Lys + Lys/Lys), Lugol-voiding lesion grade C, and drinking history. In conclusion, the protective role of NRF2 against carcinogenesis from alcohol exposure might be disrupted in the background esophageal mucosa of ESCC patients, which might lead to a high incidence of metachronous ESCC.

Nitric oxide could promote development of Barrett's esophagus by S-nitrosylation-induced inhibition of Rho-ROCK signaling in esophageal fibroblasts.

Barrett's esophagus arises in the process of wound healing in distal esophageal epithelium damaged by gastroesophageal reflux disease. Differentiation of fibroblast into myofibroblasts, a smooth muscle cell-like phenotype and tissue contraction are crucial processes in wound healing. No study has evaluated mechanism by which luminal esophageal nitric oxide (NO) affect Rho-associated coiled coil-forming protein kinase (Rho-ROCK) signaling pathway, a key factor of tissue contraction, in stromal fibroblasts to develop Barrett's esophagus. Using esophageal fibroblasts, we performed collagen-based cell contraction assays and evaluated influence of Rho-ROCK signaling in the exposure to acidic bile salts and NOC-9, which is an NO donor. We found that enhanced cell contraction induced by acidic bile salts was inhibited by NO, accompanied by decrease in phosphorylated myosin light chain expression and stress fiber formation. NO directly S-nitrosylated GTP-RhoA and consequently blocked Rho-ROCK signaling. Moreover, exposure to NO and Y27632, a Rho-ROCK signaling inhibitor, decreased α-SMA expression and increased bone morphogenetic protein-4 (BMP4) expression and secretion. These findings could account for the increased expression of BMP4 in the columnar epithelial cells and stromal fibroblasts in human Barrett's esophagus. NO could impair wound contraction by blocking the Rho-ROCK signaling pathway and promote the development of Barrett's esophagus.NEW & NOTEWORTHY Barrett's esophagus is the condition where esophageal epithelium damaged by gastroesophageal reflux disease (GERD) is abnormally healed via replacing of metaplastic columnar epithelium, but very few studies have conducted focusing wound healing in the development of Barrett's esophagus. Esophageal luminal nitric oxide inhibits Rho-ROCK signaling pathway in esophageal fibroblasts, which leads to delay tissue contraction, a pivotal step in proper wound healing. Moreover, this inhibition increases tissue BMP4 expression. Impaired wound healing could be related to Barrett's esophagus.

A Rare Case of Localized Esophageal Amyloidosis.

A 72-year-old man without any symptoms was referred to our hospital. Esophagogastroduodenoscopy revealed an elevated esophageal lesion that was covered with normal mucosa. The examination of biopsy specimens from the lesion revealed amyloid light-chain (AL) (λ) type amyloid deposits, but there were no amyloid deposits elsewhere in the gastrointestinal tract. Further examinations did not indicate systemic amyloidosis. Thus, this case was diagnosed as a localized esophageal amyloidosis. As the clinical outcome of localized amyloidosis is favorable, this case was scheduled for close follow-up. Localized amyloidosis should be considered in the differential diagnosis of esophageal submucosal tumors.

Impaired Mucosal Integrity in Proximal Esophagus Is Involved in Development of Proton Pump Inhibitor-Refractory Nonerosive Reflux Disease.

BACKGROUND AND OBJECTIVE: Weakly acidic reflux reaching to the proximal esophagus is closely related to the perception of gastroesophageal reflux in patients with nonerosive reflux disease despite treatment with a proton pump inhibitor (PPI). However, little is known about the involvement of the patients' mucosal integrity of the proximal esophagus. METHODS: We recruited 15 symptomatic nonerosive gastroesophageal reflux disease (GERD) patients with a positive symptom index despite PPI treatment and 11 healthy asymptomatic volunteers as controls. The biopsy specimens obtained from the proximal and distal esophagus were applied to a mini-Ussing chamber system to measure transepithelial electrical resistance (TEER) against a pH 4 weak acid. The esophageal biopsy samples were subjected to quantitative real-time PCR and immunohistochemical analysis. RESULTS: In the proximal esophagus, the weak acid exposure reduced the TEER in the PPI-refractory patients compared to that in the controls. The frequency of the reflux extending to the proximal esophagus had a significant correlation with the reduction in the proximal esophageal TEER in the patients. The reduced TEER in the proximal esophagus was accompanied by an increase in IL-8 and IL-1ß mRNA and a decrease in occludin mRNA levels. The proximal esophageal mucosa in the patients presented infiltration of CD3-positive lymphocytes and an increased expression of solute carrier organic anion transporter family member 2A1 (SLCO2A1), a passage gate of reflux symptom-evoking molecules. CONCLUSIONS: The reflux perception is related to an impairment of the proximal esophageal mucosal integrity in patients with nonerosive reflux disease despite PPI.

The Ameliorating Effect of Switching to Vonoprazan: A Novel Potassium-Competitive Acid Blocker in Patients with Proton Pump Inhibitor Refractory Non-Erosive Reflux Disease.

INTRODUCTION: Weakly acidic reflux has been reported to be the major cause of symptoms in patients with proton pump inhibitor (PPI)-refractory nonerosive reflux disease (NERD) undergoing PPI treatment. We previously reported that reflux at pH 4-5 was the main factor that induced symptoms in such patients. The present study aimed to elucidate the symptom-ameliorating effect of vonoprazan (VPZ) by evaluating the change in the pH value of the refluxate using multichannel intraluminal impedance and pH (MII-pH) monitoring. METHODS: We retrospectively evaluated the records of MII-pH monitoring in 29 symptom index (SI) and/or symptom association probability (SAP)-positive patients with PPI-refractory NERD. After switching to VPZ 20 mg/day, we performed MII-pH monitoring again. We assessed the change in the score of the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), the pH value of the refluxate, and the percent times of intragastric pH <4 or <5 before and after switching. We divided the patients into the following 2 groups according to the FSSG score after switching: effective and noneffective groups. RESULTS: Among of the 29 SI/SAP-positive patients, 16 underwent switching to VPZ. Furthermore, of these 16 patients, 10 underwent MII-pH monitoring again after switching. The FSSG score decreased, the pH value of the refluxate increased, and the percent times of intragastric pH <4 or <5 reduced after switching when compared with the findings before switching. In the effective group, both the proportion of reflux at pH <4 and that of reflux at pH 4-5 decreased while taking VPZ when compared with the findings while taking double-dose PPI. In the noneffective group, the proportion of reflux at pH <4 decreased but that of reflux at pH 4-5 increased and that of reflux at pH <5 did not change overall while taking VPZ. In addition, the percent times of intragastric pH <5 values were low in the effective group. CONCLUSION: Symptom suppression appears to be inadequate in patients with persistent reflux at pH 4-5 even with VPZ 20 mg/day. Strong acid suppressive therapy with VPZ to increase the pH value of the refluxate to ≥5 is useful for symptom improvement.

Localized Gastric Amyloidosis that Displayed Morphological Changes over 10 Years of Observation.

We herein report an extremely rare case of localized gastric amyloidosis (LGA) with morphological changes during the follow-up. A 71-year-old woman who had a depressed lesion with central elevation in the gastric lower body was diagnosed with LGA. Esophagogastroduodenoscopy at 10 years after the initial examination showed that the lesion had grown and changed morphologically, exhibiting a submucosal tumor-like appearance. Since the lesion was confined to the submucosa, the patient underwent endoscopic submucosal dissection. The final pathological diagnosis was amyloid light-chain (AL)-type LGA. This case may provide useful information regarding the natural history of AL-type LGA.

Duodenal Obstruction Caused by the Long-term Recurrence of Appendiceal Goblet Cell Carcinoid.

A 38-year-old Japanese man who had been diagnosed with appendiceal carcinoid and undergone ileocecal resection 8 years before presented with duodenal obstruction caused by a submucosal tumor-like appearance. He was diagnosed with long-term recurrence of appendiceal goblet cell carcinoid (GCC) with a multi-morphological pattern based on the histological assessment of a duodenal biopsy and his previously resected appendix. He underwent subtotal stomach-preserving pancreaticoduodenectomy combined with resection of an ileo-colic anastomotic lesion. The GCC recurred at the nearby ileo-colic anastomosis and invaded the duodenum. This late recurrence might have resulted from the unique features of his GCC, which contained cells with different degrees of malignancy.

Sox2 induces tumorigenesis and angiogenesis of early-stage esophageal squamous cell carcinoma through secretion of Suprabasin.

Early stage of esophageal squamous cell carcinoma (ESCC) is known to be accompanied by angiogenesis and morphological changes of microvessels. Transcription factor Sox2 is amplified in various cancers including ESCC, but the role of Sox2 in the carcinogenesis and angiogenesis has not been determined. Hence, we aimed to investigate the role of Sox2 in the early stage of ESCC. We found that the expression of Sox2 was significantly higher in early-stage ESCC tissues than that in their adjacent normal tissues. We then established Sox2-inducible normal human esophageal squamous cell line (HetSox2) to investigate the role of Sox2 in esophageal carcinogenesis and angiogenesis in vitro. Sox2 overexpression led to increased cell proliferation and spheroid formation. The culture supernatant of Sox2-overexpressing HetSox2 induced migration and sprouting of endothelial cell line HUVEC (human umbilical vein endothelial cell). As for the mechanism, we found that the expression of secreted protein Suprabasin was directly induced by Sox2. Suprabasin enhanced proliferation of normal human esophageal squamous cells when added to the culture. Moreover, Suprabasin enhanced migration and sprouting of HUVEC cells, which were observed with the culture supernatant of Sox2-overexpressing HetSox2. This angiogenic effect of Suprabasin was abolished by inhibiting AKT phosphorylation, which suggested its dependence on AKT signaling. Finally, we showed that Suprabasin expression and the density of microvessels were significantly higher in ESCC tissues with high Sox2 expression. Our study suggested that increased Sox2 expression in esophageal squamous cells induced Suprabasin expression, and as a result initiated the carcinogenesis via increased cell proliferation and angiogenesis.

Influence of the pH Value of Refluxate and Proximal Extent on Heartburn Perception in Patients with Proton Pump Inhibitor-Refractory Non-Erosive Reflux Disease.

BACKGROUND AND OBJECTIVES: Weakly acidic reflux has been reported as the major cause of symptom occurrence in patients with proton pump inhibitor (PPI)-refractory non-erosive reflux disease (NERD). This study is aimed at clarifying whether the pH value of weakly acidic reflux affects the induction of symptoms. METHODS: We retrospectively evaluated the records of combined multichannel intraluminal impedance and pH monitoring in 57 patients with PPI-refractory NERD. Weakly acidic refluxes were divided into 3 categories based on the pH value of the refluxate: pH 4-5, 5-6, and 6-7. RESULTS: A total of 29 patients were positive in the symptom index. The symptom provocation rate in reflux of pH 4-5 (19%) was much higher than in that of pH 5-6 (11%) and pH 6-7 (12%). In the reflux at pH 4-5, the symptom provocation rate in the proximal reflux was higher than that in the distal reflux (p < 0.05), whereas the reflux at pH 5-6 and pH 6-7 was not significantly different in the symptom provocation rate between the proximal and distal refluxes. CONCLUSION: Reflux at pH <5 reaching the proximal esophagus was the main factor in the induced symptoms of patients with PPI-refractory NERD.

Strong Intra-Esophageal Reflux May Contribute to the Development of Barrett's Adenocarcinoma and Affect the Localization.

BACKGROUND: There has been no study that has directly measured the esophageal reflux factors in Barrett's adenocarcinoma (BA) using 24-h multichannel intraluminal impedance-pH monitoring (24-h MII-pH). We aimed to clarify the esophageal reflux factors in Barrett's esophagus (BE) and BA and the factors that determine the location of BA with 24-h MII-pH. METHODS: We performed 24-h MII-pH in 26 patients with superficial BA treated endoscopically (BA group) and 13 patients with BE (BE group) and examined the esophageal reflux factors (esophageal acid exposure time [AET], bolus exposure (acid, weakly acid, and alkaline), and number of reflux episodes. In the BA group, there were 16 cases in which the lesions were localized in an area in contact with the esophagogastric junction (EGJ; EGJ group), and 10 cases in which the lesions were proximal to the BE and separated from the EGJ (non-EGJ group). RESULTS: Total reflux in the bolus exposure in the BA group showed higher values compared to that in the BE group. The total of acid and weakly acid reflux of bolus exposure was significantly higher in the BA group than that in the BE group. The BA group also had greater numbers of total reflux episodes than the BE group. As for the cancer locations in BE, the cases in which the lesions were located proximally and separated from the EGJ had more AET and total reflux and acid reflux indicated by bolus exposure compared to the lesions adjacent to the EGJ. CONCLUSIONS: Stronger gastro-esophageal reflux appeared to be an important factor in the development of adenocarcinoma from BE. In addition, the cancer location in BE may be related to the intensity of esophageal reflux.

T-cell Lymphoma Presenting Neutrophilic Inflammation in the Cerebrospinal Fluid.

A 66-year-old woman presented with upper abdominal pain and weakness in the limbs. She had bilateral uveitis and gastric ulcers. A neurological examination revealed tetraparesis and sensory disturbance in the right arm. A cerebrospinal fluid (CSF) examination showed polymorphonuclear pleocytosis with elevated pro-inflammatory cytokine levels. Magnetic resonance imaging showed brain lesions and a long spinal cord lesion. She was initially diagnosed with neuro-Behçet's disease and was treated with corticosteroids, resulting in no improvement. A gastric mucosa biopsy indicated T-cell lymphoma colocalizing with neutrophils. The cytokine-mediated neutrophilic inflammation probably caused characteristic CSF and histopathological features. It is noteworthy that T-cell lymphoma may present with CSF neutrophilic inflammation.

Difficult Preoperative Diagnosis of Lymphoepithelioma-Like Carcinoma of the Esophagus.

A 60-year-old man with a medical history of diabetes, liver cirrhosis, and distal gastrectomy was referred for further examination of a 10-mm pale-colored submucosal tumor around 40 cm from the incisors. Narrow band imaging-magnifying endoscopy revealed the lesion covered by smooth epithelium with irregular microvascular architecture in a sparse distribution. Endosonography showed an irregular-shaped hypoechoic lesion in the submucosa. With no evidence of metastases, we performed en bloc endoscopic submucosal dissection, whose specimen revealed esophageal lymphoepithelioma-like carcinoma invading up to 500 µm in the submucosa, a rare disease entity. Despite no additional treatment, he was alive without recurrence for longer than 88 months.

Endoscopic Findings of Esophageal Adenosquamous Carcinoma Diagnosed by Endoscopic Mucosal Resection.

Adenosquamous carcinoma (ASC) is a rare histological type of esophageal carcinoma. Esophagogastroduodenoscopy for the health checkup of a 71-year-old male revealed the presence of a slightly elevated lesion like a submucosal tumor at the lower part of the esophagus. The center of it was slightly depressed, and the depressed area was not stained by iodine. Magnifying endoscopy with narrow-band imaging revealed reticular pattern vessels in the depressed area, whereas no irregularity of the microvascular pattern of the surrounding area was evident. One of the biopsied specimens taken from the depressed area was diagnosed as squamous intraepithelial neoplasia, but a malignant tumor with submucosal invasion was suspected based on the findings of endoscopic ultrasonography. Endoscopic mucosal resection using a cap-fitted endoscope was performed, and the lesion was diagnosed as esophageal ASC histologically. Carcinomas that formed nested and ductal structures existed in the lamina propria and invaded to the submucosa. Almost all of them were covered by non-invasive intraepithelial neoplasia, whereas small erosion was seen in the central depressed area. The growing pattern of ASC was quite different from that of typical differentiated squamous cell carcinomas. When we do endoscopic examination for an esophageal lesion like submucosal tumor, we have to consider the possibility of an esophageal carcinoma that has a similar growing pattern. If reticular pattern vessels are seen with magnifying endoscopy, the existence of an invasive carcinoma is suspected, and additional endoscopic ultrasonography is recommended. Possible efforts to gain histological findings have to be made using bowling biopsy, endoscopic resection, and so on.

A Primary Barrett's Adenocarcinoma with a Squamous Cell Carcinoma Component.

The present report describes an extremely rare case of Barrett's adenocarcinoma (BAC) with a squamous cell carcinoma (SCC) component. A 55-year-old man was diagnosed with esophageal adenocarcinoma on Barrett's esophagus. The patient underwent endoscopic submucosal dissection, but the pathology revealed deep submucosal invasive, moderately differentiated tubular adenocarcinoma and focal SCC with vascular invasion. In addition, morphological transition between adenocarcinoma and SCC components was confirmed. The patient underwent additional surgery, which revealed lymph node metastasis, and then received S-1 adjuvant chemotherapy. Based on the pathological findings, the transdifferentiation process may have a role in the histogenesis of this tumor.

Continuous liquid-suction catheter attachment for endoscope reduces volume of liquid reflux to the mouth in esophageal endoscopic submucosal dissection.

BACKGROUND AND AIM: Pooling of liquid in the esophageal lumen can worsen the field of vision and cause liquid reflux to the mouth, which leads to aspiration pneumonia, in esophageal endoscopic submucosal dissection (ESD). We developed a continuous liquid-suction catheter attachment for the endoscope (CLCA) that has multiple tiny holes and can suction the liquid without causing mucosal injury. Thus, we aim to show the efficacy of CLCA in esophageal ESD. METHODS: This was a single-blinded, randomized controlled trial involving patients with superficial esophageal cancer. The enrolled patients were randomly assigned to the conventional ESD (C-ESD) or ESD with CLCA (CLCA-ESD) groups. Primary endpoint was volume of liquid reflux to the mouth during the ESD procedure. Secondary endpoints were incidence of aspiration pneumonia and procedure time. RESULTS: Fifty patients were enrolled in this trial. Volume of liquid reflux to the mouth was significantly lower in the CLCA-ESD group than in the C-ESD group (mean: 10 vs 73 mL, P = 0.010). Furthermore, the incidence of aspiration pneumonia on computed tomography (CT) scan between the two groups was also significantly different (4.0% vs 32.0%, P = 0.023), although no significant difference was observed through chest radiography. In addition, procedure time tended to be shorter in the CLCA-ESD group (P = 0.054). CONCLUSION: This study first showed that use of CLCA in esophageal ESD reduced the volume of liquid reflux to the mouth and contributed to decreased incidence of aspiration pneumonia on CT scan (UMIN000018167).

The Use of Higher Dose Steroids Increases the Risk of Rebleeding After Endoscopic Hemostasis for Peptic Ulcer Bleeding.

BACKGROUND: Previous studies have shown that several factors such as hemodynamic instability at admission are risk factors for rebleeding of peptic ulcer bleeding. However, whether steroid use increases the risk of rebleeding remains elusive. AIMS: This study aimed to clarify the risk factors for rebleeding after endoscopic hemostasis for peptic ulcer bleeding. METHODS: A total of 185 patients who underwent endoscopic hemostasis for peptic ulcer bleeding at our institution between 2005 and 2017 were retrospectively analyzed. We evaluated factors, including comorbid conditions, in-hospital onset, and steroid use, associated with rebleeding by logistic regression analysis. In addition, we investigated the association between the dose of steroids and rebleeding. RESULTS: The rebleeding rate after endoscopic hemostasis for peptic ulcer bleeding was 14.6%. In the multivariate analysis, the independent risk factors for rebleeding were steroid use (odds ratio 4.56, p = 0.015), multiple ulcers (4.43, p = 0.005), number of comorbidities ≥ 3 3.18, p = 0.026), hemodynamic instability (3.06, p = 0.039), and number of comorbidities ≥ 3 (2.93, p = 0.047). Furthermore, the use of higher dose steroids (≥ 20 mg per day in prednisolone; 10.55, p = 0.002), but not lower dose (< 20 mg per day in prednisolone), was an independent risk factor for rebleeding in the multivariate analysis. The relationship between steroid use and rebleeding was observed in a dose-dependent manner (p for trend = 0.002). CONCLUSIONS: This study first revealed that using higher dose steroids was an independent risk factor for rebleeding after endoscopic hemostasis for peptic ulcer bleeding, with a dose-response relation.

Leptin Aggravates Reflux Esophagitis by Increasing Tissue Levels of Macrophage Migration Inhibitory Factor in Rats.

Leptin, produced primarily by the adipose tissue, acts as a pro-inflammatory modulator, thereby contributing to the development of obesity-related disease. Although high levels of leptin in the obese are closely related to gastroesophageal reflux disease, the mechanism by which leptin influences esophageal inflammation remains unknown. Macrophage migration inhibitory factor (MIF) is produced by immune cells, such as T lymphocytes and macrophages, and MIF is known to induce the production of tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß) and interleukin 6 (IL-6). We therefore investigated the mechanism whereby leptin aggravates reflux esophagitis, by focusing on esophageal tissue levels of MIF and CD3+ T lymphocytes, both of which are crucial for the reflux-induced epithelial damage. Esophageal inflammation was surgically induced in male Wistar rats by ligating the forestomach and narrowing the duodenum to facilitate gastroesophageal reflux, followed by administration of leptin or vehicle with an osmotic pump system for 1 week. We demonstrated that the administration of leptin exacerbated the reflux esophagitis with the apparent infiltration of CD3+ T lymphocytes and caused the significant increase in the esophageal tissue levels of MIF. Moreover, the leptin caused increases in the esophageal tissue levels of TNF-α, IL-1ß and IL-6, downstream targets of MIF. Importantly, the increases in these pro-inflammatory cytokines were accompanied by increased protein levels of phospho-STAT3 and phospho-AKT, pivotal molecules of leptin signaling pathways. In conclusion, through enhancing the MIF-induced inflammatory signaling, leptin could contribute to the development of gastroesophageal reflux disease.

Acidic bile salts induces mucosal barrier dysfunction through let-7a reduction during gastric carcinogenesis after Helicobacter pylori eradication.

Gastric cancer (GC) after eradication for Helicobacter pylori (H.pylori) increases, but its carcinogenesis is not elucidated. It is mainly found in acid non-secretion areas (ANA), as mucosal regeneration in acid secretory areas (AA) after eradication changes the acidity and bile toxicity of gastric juice. We aimed to clarify the role of barrier dysfunction of ANA by the stimulation of pH3 bile acid cocktail (ABC) during carcinogenesis. We collected 18 patients after curative endoscopic resection for GC, identified later than 24 months after eradication, and took biopsies by Congo-red chromoendoscopy to distinguish AA and ANA (UMIN00018967). The mucosal barrier function was investigated using a mini-Ussing chamber system and molecular biological methods. The reduction in mucosal impedance in ANA after stimulation was significantly larger than that in AA, 79.6% vs. 87.9%, respectively. The decrease of zonula occludens-1 (ZO-1) and let-7a and the increase of snail in ANA were significant compared to those in AA. In an in vitro study, the restoration of ZO-1 and let-7a as well as the induction of snail were observed after stimulation. High mobility group A2 (HMGA2)-snail activation, MTT proliferation, and cellular infiltration capacity were significantly increased in AGS transfected with let-7a inhibitor, and vice versa. Accordingly, using a mini-Ussing chamber system for human biopsy specimens followed by an in vitro study, we demonstrated for the first time that the exposure of acidic bile salts to ANA might cause serious barrier dysfunction through the let-7a reduction, promoting epithelial-mesenchymal transition during inflammation-associated carcinogenesis even after eradication.