A new paradigm for GERD pathogenesis. Not acid injury, but cytokine-mediated inflammation driven by HIF-2α: a potential role for targeting HIF-2α to prevent and treat reflux esophagitis

Pepsin-mediated inflammation in laryngopharyngeal reflux via the ROS/NLRP3/IL-1β signaling pathway

BACKGROUND

Laryngopharyngeal reflux (LPR) is one of the most common disorders in otorhinolaryngology, affecting up to 10% of outpatients visiting otolaryngology departments. In addition, 50% of hoarseness cases are related to LPR. Pepsin reflux-induced aseptic inflammation is a major trigger of LPR; however, the underlying mechanisms are unclear. The nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome has become an important bridge between stimulation and sterile inflammation and is activated by intracellular reactive oxygen species (ROS) in response to danger signals, leading to an inflammatory cascade. In this study, we aimed to determine whether pepsin causes LPR-associated inflammatory injury via mediating inflammasome activation and explore the potential mechanism.

METHODS

We evaluated NLRP3 inflammasome expression and ROS in the laryngeal mucosa using immunofluorescence and immunohistochemistry. Laryngeal epithelial cells were exposed to pepsin and analyzed using flow cytometry, western blotting, and real-time quantitative PCR to determine ROS, NLRP3, and pro-inflammatorycytokine levels.

RESULTS

Pepsin expression was positively correlated with ROS as well as caspase-1 and IL-1β levels in laryngeal tissues. Intracellular ROS levels were elevated by increased pepsin concentrations, which were attenuated by apocynin (APO)-a ROS inhibitor-in vitro. Furthermore, pepsin significantly induced the mRNA and protein expression of thioredoxin-interacting protein, NLRP3, caspase-1, and IL-1β in a dose-dependent manner. APO and the NLRP3 inhibitor, MCC950, inhibited NLRP3 inflammasome formation and suppressed laryngeal epithelial cell damage.

CONCLUSION

Our findings verified that pepsin could regulate the NLRP3/IL-1β signaling pathway through ROS activation and further induce inflammatory injury in LPR. Targeting the ROS/NLRP3 inflammasome signaling pathway may help treat patients with LPR disease.

Mucosal neuroimmune mechanisms in gastro-oesophageal reflux disease (GORD) pathogenesis

Gastro-oesophageal reflux disease (GORD) is a chronic condition characterised by visceral pain in the distal oesophagus. The current first-line treatment for GORD is proton pump inhibitors (PPIs), however, PPIs are ineffective in a large cohort of patients and long-term use may have adverse effects. Emerging evidence suggests that nerve fibre number and location are likely to play interrelated roles in nociception in the oesophagus of GORD patients. Simultaneously, alterations in cells of the oesophageal mucosa, namely epithelial cells, mast cells, dendritic cells, and T lymphocytes, have been a focus of GORD research for several years. The oesophagus of GORD patients exhibits both macro- and micro-inflammation as a response to chronic acidic reflux at the epithelium. In other conditions of the GI tract, such as IBS and IBD, well-characterised bidirectional processes between immune cells and mucosal nerve fibres contribute to pathogenesis and symptom generation. Sensory alterations in these conditions such as nerve fibre outgrowth and hypersensitivity can be driven by inflammatory processes, which promote visceral pain signalling. This review will examine what is currently known of the molecular pathways linking inflammation and sensory perception leading to the development of GORD symptoms and explore potentially relevant mechanisms in other GI regions which may indicate new areas in GORD research.

Rheumatoid arthritis and gastroesophageal reflux disease: a bidirectional and multivariable two-sample Mendelian randomization study

Aims/hypothesis: The association between gastroesophageal reflux disease (GERD) and rheumatoid arthritis (RA) has been reported by many observational studies in the Asian population. This study aimed to examine the bidirectional causal effects between GERD and RA by two-sample Mendelian randomization (MR) analyses using genetic evidence. Methods: Two-sample Mendelian randomization analyses were performed to determine the causal effect of GERD (129,080 cases vs. 602,604 control participants) on RA (6,236 cases vs. 147,221 control participants) and RA on GERD, respectively. The inverse-variance weighted (IVW) method was used as the primary analysis. Weighted median and MR-Egger regression were taken as supplementary analyses. Cochran's Q test evaluated the heterogeneity. Horizontal pleiotropy was detected by estimating the intercept term of MR-Egger regression. Furthermore, multivariable MR analyses were performed to exclude the influence of confounding factors, including the years of schooling, BMI, and time spent watching television, between GERD and RA. Result: Both univariate MR (UVMR) and multivariable MR (MVMR) provided valid evidence that RA was causally and positively influenced by GERD (UVMR: OR = 1.49, 95% CI = 1.25-1.76, p = 6.18*10-6; MVMR: OR = 1.69, 95% CI = 1.24-2.31, p = 8.62*10-4), whereas GERD was not influenced by RA (UVMR: OR = 1.03, 95% CI = 1.00-1.06, p = 0.042; MVMR: OR = 1.04, 95% CI = 1.00-1.07, p = 0.0271). Conclusion: Our comprehensive bidirectional MR analysis found that for the European population, GERD can induce the occurrence of RA (OR = 1.69, p < 0.00125), whereas RA only has no significant influence on GERD. In particular, patients with GERD are suffering a 69% increased risk of RA occurrence, which means GERD is a substantial risk factor for RA.

Revisiting Proton Pump Inhibitors as Chemoprophylaxis Against the Progression of Barrett's Esophagus

PURPOSE OF REVIEW

Barrett's esophagus (BE) is associated with chronic gastroesophageal reflux disease and is a known precursor to esophageal adenocarcinoma. While endoscopic surveillance strategies and the role for endoscopic eradication therapy have been well established, there has been much interest in identifying chemopreventive agents to disrupt or halt the metaplasia-dysplasia-carcinoma sequence in patients with BE.

RECENT FINDINGS

No pharmacological agent has held more hope in reducing the risk of neoplastic progression in BE than proton pump inhibitors (PPIs). However, data supporting PPIs for chemoprevention have largely been from observational cohort and case-control studies with mixed results. In this review, we revisit the literature and highlight the role of PPIs in patients with BE as it pertains to chemoprophylaxis against the progression of BE to dysplasia and esophageal adenocarcinoma.

The Impact of Intermittent Fasting on Patients With Suspected Gastroesophageal Reflux Disease

GOAL

The aim was to investigate the short-term impact of time restricted feeding on patients with suspected gastroesophageal reflux disease (GERD).

BACKGROUND

Lifestyle modifications are often suggested, but the role of diet in GERD is unclear. Intermittent fasting is popular in the media and has demonstrated potential benefits with weight loss and inflammatory conditions as well as alterations in gastrointestinal hormones.

STUDY

Patients who were referred for 96-hour ambulatory wireless pH monitoring off proton pump inhibitor to investigate GERD symptoms were screened for eligibility. Patients were instructed to maintain their baseline diet for the first 2 days of pH monitoring and switch to an intermittent fasting regimen (16 consecutive hour fast and 8 h eating window) for the second 2 days. Objective measures of reflux and GERD symptom severity were collected and analyzed.

RESULTS

A total of 25 participants were analyzed. 9/25 (36%) fully adhered to the intermittent fasting regimen, with 21/25 (84%) demonstrating at least partial compliance. Mean acid exposure time on fasting days was 3.5% versus 4.3% on nonfasting days. Intermittent fasting was associated with a 0.64 reduction in acid exposure time (95% CI: -2.32, 1.05). There was a reduction in GERD symptom scores of heartburn and regurgitation during periods of intermittent fasting (14.3 vs. 9.9; difference of -4.46, 95% CI: -7.6,-1.32).

CONCLUSIONS

Initial adherence to time restricted eating may be difficult for patients. There is weak statistical evidence to suggest that intermittent fasting mildly reduces acid exposure. Our data show that short-term intermittent fasting improves symptoms of both regurgitation and heartburn.

Signaling Pathways in the Pathogenesis of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus (BE) is a premalignant lesion that can develop into esophageal adenocarcinoma (EAC). The development of Barrett's esophagus is caused by biliary reflux, which causes extensive mutagenesis in the stem cells of the epithelium in the distal esophagus and gastro-esophageal junction. Other possible cellular origins of BE include the stem cells of the mucosal esophageal glands and their ducts, the stem cells of the stomach, residual embryonic cells and circulating bone marrow stem cells. The classical concept of healing a caustic lesion has been replaced by the concept of a cytokine storm, which forms an inflammatory microenvironment eliciting a phenotypic shift toward intestinal metaplasia of the distal esophagus. This review describes the roles of the NOTCH, hedgehog, NF-κB and IL6/STAT3 molecular pathways in the pathogenesis of BE and EAC.

The Relationship between Gastroesophageal Reflux Disease and Chronic Kidney Disease

Gastroesophageal reflux disease (GERD) is commonly seen in patients with chronic kidney disease (CKD), although data on the relationship between these conditions are still limited. We aimed to explore whether CKD is related to a higher prevalence of GERD and its complications. National Inpatient Sample data were used in this retrospective analysis, including 7,159,694 patients. Patients who had a diagnosis of GERD with and without CKD were compared with patients without GERD. Complications associated with GERD that were analyzed included Barrett's esophagus and esophageal stricture. Risk factors of GERD were used for variable adjustment analysis. Different stages of CKD were evaluated in patients with and without GERD. Bivariate analyses were performed using the chi-squared test or Fisher exact test (2-tailed) for categorical variables as appropriate to assess the difference. There were significantly different demographic characteristics between GERD patients with and without CKD regarding age, sex, race, and other co-mobilities. Interestingly, a greater prevalence of GERD was seen in CKD patients (23.5%) compared to non-CKD patients (14.8%), and this increased prevalence was consistently seen in all CKD stages. CKD patients also had 1.70 higher odds of risk of having GERD compared with non-CKD after adjustment. The association between different stages of CKD and GERD showed a similar trend. Interestingly, patients with early-stage CKD were found to have a higher prevalence and odds of risk of esophageal stricture and Barrett's esophagus than non-CKD patients. CKD is associated with a high prevalence of GERD and its complications.

Network pharmacology-based prediction and verification of the active ingredients and potential targets of Huagan Decoction for reflux esophagitis

ETHNOPHARMACOLOGICAL RELEVANCE

Huagan Decoction (HGD), a famous traditional Chinese medicine (TCM) formula, has been widely used in the treatment of reflux esophagitis (RE). However, its effective compounds, potential targets and molecular mechanism remain unclear.

AIM OF THE STUDY

To investigate effective compounds, potential targets and molecular mechanism of HGD against RE by using network pharmacology combined with in vitro validation, with the aims of observing the action of HGD and exploring new therapeutic strategies for RE treatment.

MATERIALS AND METHODS

Effective compounds and potential targets of HGD, as well as related genes of RE, were collected from public databases. Pharmacological clustering and Gene Ontology (GO) enrichment analysis were applied to find targets that involving in the anti-inflammatory module. The pathways were drawn using Cytoscape 3.8.0. Important ingredients, potential targets, and signaling pathways were determined through the construction of protein-protein interaction (PPI), GO and Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, cell experiments were carried out.

RESULTS

A total of 54 active ingredients and 240 RE-related gene targets of HGD were identified. The active compound-target network was visualized and pharmacological clustering further sorted 53 proteins that involve in the regulation of inflammatory responses. GO analysis confirmed the classification was statistically significant. Analysis of compound-target network revealed that quercetin and geniposide may be key ingredients for the anti-inflammatory effect of HGD against RE. The potential targets regulated by HGD are IL-6, IL-1β, PTGS2, AKT1, TNF-α, MAPK1, IL-8, IL-10, CCL2 and MAPK3. In vitro experiment showed that quercetin and geniposide could inhibit the inflammatory response of HET-1A cells through p38MAPK/NF-κB signaling pathway, which was consistent with the prediction by the network pharmacology approach.

CONCLUSIONS

Geniposide and quercetin could be effective therapeutic ingredients for the HGD against RE. They play anti-inflammatory effects via down-regulating the pro-inflammatory cytokines and the conduction of p38MAPK/NF-κB signal. This research provides a comprehensive study on the active components, potential targets, and molecular mechanisms of HGD against RE. Moreover, the study supplies a feasible approach to reveal the mechanisms of TCM formula.

The relationship between gastroesophageal reflux disease and autism spectrum disorder in adult patients in the United States

BACKGROUND

Gastroesophageal reflux disease (GERD) has been associated with psychiatric and neurocognitive disorders. Those with autism spectrum disorder (ASD) are prone to gastrointestinal (GI) diseases, but most research has been done on children. Our aim was to determine the relationship between GERD and autism in adults and assess GERD-related complications in those with autism.

METHODS

A national cohort of adults aged 18 and above with GERD with and without ASD were compared to those without GERD. Complications of GERD that were studied included Barrett's esophagus, erosive esophagitis, esophageal stricture, ulcer, and malignancy. Conditions associated with GERD were evaluated including chronic cough, wheezing, sore throat, non-cardiac chest pain, and hoarseness. GERD treatment that was evaluated included proton pump inhibitors (PPIs), H2 receptor antagonists (H2RA), and anti-reflux surgery.

KEY RESULTS

There was an increased risk of GERD in subjects with ASD (p = 0.0001). Erosive esophagitis and esophageal ulcer were more likely to occur in those with GERD and ASD (p = 0.0001). Those with ASD were at higher risk of suffering from wheezing following a diagnosis of GERD compared to those without ASD (p = 0.0001). Those with GERD and ASD were more likely to be treated with an H2RA both as monotherapy and in combination with PPI versus those without ASD (p = 0.0001 and p = 0.0037, respectively).

CONCLUSIONS AND INFERENCES

Adult patients with ASD are more likely to have GERD as well as complications including erosive esophagitis and esophageal ulcer. Treatment of patients with GERD and ASD is not consistent and may suggest health care disparities.

Protective Mechanisms of Liquid Formulations for Gastro-Oesophageal Reflux Disease in a Human Reconstructed Oesophageal Epithelium Model

Purpose

A novel experimental design based on a human-reconstructed oesophageal epithelium (HO2E) model has been applied to quantitively assess the properties of a set of liquid formulations, Device A (Gerdoff^® Protection), Device B (Esoxx^® One), and Device C (Marial^® gel) developed to form a temporary physical barrier on the oesophageal epithelium and modify epithelial permeability so to protect the oesophageal mucosa from refluxate components.

Methods

The formulations were applied to a prewetted HO2E model for 15 min. Then, a 0.5% caffeine solution was applied, and its penetration kinetics was assessed at 1 h and 2 h in acidic environments (pH= 3.3) to mirror exposure of the oesophageal mucosa to acidic reflux in GORD patients. Caffeine permeated into the basolateral compartment (evaluated by HPLC-UV) and Lucifer yellow (LY) permeability were quantified 15 min after application of the caffeine in acidic environments.

Results

At the 15 min timepoint, Device A reduced caffeine permeation by 77.2% and LY flux by 30.4% compared to the untreated control and with a faster mode of action than that of the other liquid formulations. Transepithelial caffeine flux was reduced, albeit with different timing and efficiency, by all three compounds up to the end of the 2 hour experiment. At 1 h, Device A reduced the caffeine flux by 79.2%; Device B, by 67.2%; and Device C, by 37%.

Conclusion

These results confirm the ability of the medical devices tested to interact with the oesophageal epithelium and create a temporary physical protective film for up to 2 hours after their application. The results underline differences in the mechanism of action of the three medical devices, with Device A performing faster than the other formulations. The overall results support the relevance of the reconstructed mucosal model to investigate oesophageal epithelium–product interactions and precisely differentiate liquid formulation performance.

Expression of VEGF, EGF, and Their Receptors in Squamous Esophageal Mucosa, with Correlations to Histological Findings and Endoscopic Minimal Changes, in Patients with Different GERD Phenotypes

BACKGROUND

Gastroesophageal reflux disease (GERD) may present as nonerosive reflux disease (NERD), erosive esophagitis (EE), or be complicated by Barrett's esophagus (BE). The explanation as to what determines the phenotype of GERD is awaited. Therefore, we assessed the correlation between the growth factors expression and endoscopic as histologic findings in GERD patients.

METHODS

The squamous esophageal epithelium of 50 patients (20-NERD, 7-EE, 15-BE, 8 controls) was examined by: (1) magnification endoscopy with evaluation of minimal GERD changes such as: microerosions, white spots, palisade blood vessels visibility, and intrapapillary capillary loops (IPCLs) appearance, (2) histology, (3) immunohistochemistry with evaluation of the expression of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and their receptors (VEGFR and EGFR).

RESULTS

The expression of VEGF, but not VEGFR, EGF, and EGFR, was significantly increased in EE patients compared to NERD patients and controls. VEGF levels correlated significantly with the presence of white spots, but not with other minimal endoscopic and histologic features. The EGFR expression correlated positively with basal cell hyperplasia and enlarged IPCLs.

CONCLUSIONS

Our findings suggest a correlation between growth factors expression and findings in conventional endoscopy, formation of endoscopic minimal changes, and histologic lesions.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

Changes in laryngopharyngeal reflux after uvulopalatopharyngoplasty for obstructive sleep apnea: An observational study

PURPOSE

To estimate laryngopharyngeal reflux (LPR) changes after uvulopalatopharyngoplasty (UPPP) for obstructive sleep apnea (OSA) using the reflux symptom index (RSI) and reflux finding score (RFS) questionnaires.

METHODS

A total of 91 participants were recruited and divided into three groups: control (n = 27), OSA mild to moderate (n = 29), and OSA severe (n = 35) groups according to polysomnography. All participants completed the preoperative RSI, and underwent blinded evaluation on videolaryngoscopy using the RFS questionnaire. Thirty-four OSA patients who underwent UPPP surgery completed postoperative polysomnography and questionnaires again after a 6-month follow-up.

RESULTS

The RSI score and RFS were higher in patients with OSA than in those without OSA. Patients with severe OSA also had a higher RSI score and RFS than those with mild to moderate OSA. Apnea and hypopnea index degree and percentage of recording time for <90% oxygen saturation showed positive correlation with LPR symptoms. But the lowest blood oxygen saturation during the recording time was negatively correlated with LPR symptoms. The mean RSI score and RFS before UPPP surgery were 15.88 ± 4.85 and 13.18 ± 4.80, after surgery decreasing to 9.53 ± 4.16 and 8.65 ± 4.87, respectively (P <.05). In 25 patients where surgery was successful, RSI scores, RFSs and individual RSI variables decreased after surgery.

CONCLUSIONS

LPR symptoms are common among OSA patients, and the coexistence of OSA and LPR cannot be ignored. Successful UPPP surgery potentially reduces LPR symptoms and improves laryngoscopic signs by alleviating sleep respiratory disorders. Level of Evidence: 3.

The role of Glut-1 and H+/K+-ATPase expression in hyperplasia of mice laryngeal epithelium induced by pepsin

Purpose

To explore the role played by Glut-1 and H⁺/K⁺-ATPase in pepsin-induced, mouse laryngeal epithelial proliferation, growth, and development.

Methods

We established a mouse model of laryngopharyngeal reflux and measured Glut-1 and H⁺/K⁺-ATPase expression levels in mouse laryngeal epithelium treated with artificial gastric juice containing pepsin.

Results

Artificial pepsin-containing gastric juice induced significant hyperplastic changes in mouse laryngeal epithelium compared to control mice at 15, 30, and 45 days. Inhibition of Glut-1 expression by 2-DG significantly suppressed such hyperplasia compared to mice exposed to artificial gastric juice containing pepsin at 15, 30, and 45 days. After treatment with pepsin-containing artificial gastric juice, RT-PCR and Western blotting showed that the levels of Glut-1 and H⁺/K⁺-ATPase α, β increased significantly.

Conclusions

Pepsin-containing artificial gastric juice promoted mouse laryngeal epithelial hyperplasia associated with abnormal expression of Glut-1 and H⁺/K⁺-ATPase α, β.

The Relationship between Serum Total Oxidant Status, Total Antioxidant Status, and Oxidative Stress Index with Severity Levels of Gastroesophageal Reflux Disease: A Literature Review

Gastroesophageal reflux disease (GERD) is a global health problem in which the prevalence is increasing over periods. This disease is a significant cause of disorders in the upper gastrointestinal tract with very complex pathogenesis. Oxidative stress (OS) due to gastric acid reflux plays a role in the inflammatory response of the esophageal epithelium. Several OS markers have been widely studied and are thought to affect the severity degree of the esophageal mucosa. However, there has been no research on total oxidant status (TOS), total antioxidant status (TAS), and OS index (OSI) in the adult with GERD; hence the aim of this review was to determine the association between TOS, serum TAS, and OSI with the GERD degree. A literature review was conducted by searching articles related to the TOS, TAS, OSI, and its correlation with GERD degree on an online database, particularly Pubmed and Google scholar. We conclude that TAS and OSI might influence the severity of GERD; however, further clinical study is needed to prove this theory.

Medical Devices Made of Substances: Possible Innovation and Opportunities for Complex Natural Products

The novel Regulation 2017/745/EC on medical devices introduces and strengthens the role of "medical devices made of substances", which mostly include substances of natural origin. Natural products may follow different regulations, from food to therapeutics. Concerning their isolated constituents, extracts are characterized by a complexity that is not easily tackled from both a scientific and a regulatory point of view, but more importantly, from a therapeutic point of view. The evidence-based approach applied to isolated molecules requires appropriate evidence of quality, efficacy, and safety. The same needs must be reached for complex substances by finding appropriate methods to generate this evidence, and in addition, defining an appropriate regulatory field for them. From a scientific point of view, new methods, such as those proposed by systems biology, are available and applicable to complex substances. From a regulatory point of view, Directive 2001/83/EC on medicinal products seems to be modeled on single (or combinations of single) molecule products. On the other hand, Regulation 2017/745/EC on medical devices seems to apply to complex substances without derogating on quality, efficacy, and safety. The regulation specifically names and strengthens medical devices that include substances, mostly of natural origin, introducing the official term "medical devices made of substances". This paper discusses and proposes an interpretation of important terms connected to this legislation, regarding both scientific and regulatory issues, and the opportunities the regulation may give for innovation and therapeutic improvement with natural complex substances.

The role of hypoxia-inducible factors in the development of chronic pathology

This review highlights the current understanding of hypoxia-inducible factors (HIFs) role as regulators of oxygen-dependent reactions and inducers of genes expression in human organism. The focus is on the most significant relationships between the activation or inhibition of the HIFs intracellular system and development of the inflammatory process in various organs, chronic diseases of gastrointestinal tract, osteoarticular system, kidneys as well as hematological, endocrine and metabolic disorders.

Efficacy and safety of the Chinese herbal formula Hewei Jiangni recipe for NERD with cold-heat complex syndrome: study protocol for a double-blinded randomized controlled trial

Background

Proton pump inhibitor (PPI) is effective for the treatment of nonerosive gastroesophageal reflux (NERD), but long-term use of PPI is prone to have complications and recurrence after withdrawal. Traditional Chinese medicine (TCM) can relieve the symptoms of reflux and improve the quality of life. The purpose of this study is to evaluate the safety and efficacy of Hewei Jiangni recipe (HWJNR) in the treatment of NERD with cold-heat complex syndrome, and clarify the mechanism of HWJNR on NERD based on the correlation analysis of intestinal flora and metabolites.

Methods

This is a single-center, randomized controlled, double-blind, placebo-controlled clinical trial in which 72 eligible participants with NERD and TCM syndrome of intermingled heat and cold will be randomly allocated in the ratio of 1:1 to two groups: TCM group and western medicine group. The TCM group will receive HWJNR with omeprazole enteric-coated tablets placebo, while the western medicine group will receive omeprazole enteric-coated tablets with HWJNR placebo. Each group will be treated for 8 weeks. The primary outcome is the score of gastroesophageal reflux disease (GERD) health-related quality of life questionnaire (GERD-Q). Secondary outcomes include SF-36 quality of life scale (SF-36), patient-reported outcomes (PRO) self-rating scale score, syndrome score of TCM, and adverse events. Mechanistic outcome is the correlation analysis of intestinal flora and metabolites from healthy individuals and NERD participants before and after the treatment respectively.

Discussion

The goal of this trial is to investigate the efficacy and safety of HWJNR in the treatment of NERD with cold-heat complex syndrome, and to study the composition structure and metabolite expression profile of intestinal flora in patients with NERD through 16SrRNA sequencing and metabolomic correlation analysis of fecal flora, which makes us identify the dominant links of treatment and reveal the potential mechanism of HWJNR.

ChiCTR2000041225. Registered on 22 December 2020

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is a common disorder in adults and children. The global prevalence of GERD is high and increasing. Non-erosive reflux disease is the most common phenotype of GERD. Heartburn and regurgitation are considered classic symptoms but GERD may present with various atypical and extra-oesophageal manifestations. The pathophysiology of GERD is multifactorial and different mechanisms may result in GERD symptoms, including gastric composition and motility, anti-reflux barrier, refluxate characteristics, clearance mechanisms, mucosal integrity and symptom perception. In clinical practice, the diagnosis of GERD is commonly established on the basis of response to anti-reflux treatment; however, a more accurate diagnosis requires testing that includes upper gastrointestinal tract endoscopy and reflux monitoring. New techniques and new reflux testing parameters help to better phenotype the condition. In children, the diagnosis of GERD is primarily based on history and physical examination and treatment vary with age. Treatment in adults includes a combination of lifestyle modifications with pharmacological, endoscopic or surgical intervention. In refractory GERD, optimization of proton-pump inhibitor treatment should be attempted before a series of diagnostic tests to assess the patient's phenotype.

Helicobacter pylori infection over bile reflux: No influence on the severity of endoscopic or premalignant gastric lesion development

Helicobacter (H.) pylori infection and duodenogastric reflux (DGR) are both linked to endoscopic and premalignant gastric lesion development, but it is still unclear whether they are independent or have a causal relationship. This study investigated the histologic gastric changes in patients with primary DGR and H. pylori infection, as well as their endoscopic findings, symptoms, drug consumption, and social behavior in comparison with patients presenting only DGR. The study included 560 patients with primary DGR on endoscopy divided into two groups, according to the presence/absence of H. pylori infection on biopsy (utilizing usual stainings and immunohistochemical methods). There was no significant difference in terms of age and sex, nor in the frequency of diabetes or esophagitis between the studied groups. Epigastric pain was associated with H. pylori-positive biopsies in multivariate logistic regression analysis (P=0.005). Although without statistical significance, severe endoscopic lesions and premalignant gastric lesions were more frequent in the H. pylori group (45.1 vs. 28.4% and 37.4 vs. 32.3%, respectively). In patients with DGR, the final multivariate model revealed a positive association between smoking and immunohistochemically confirmed H. pylori infection (P=0.02, OR=1.88, 95% confidence intervals (CI)=1.10 to 3.21), but a negative effect of proton pump inhibitor consumption (P<0.001, OR=0.50, 95% CI=0.35 to 0.73). In conclusion, in patients with H. pylori infection and DGR, epigastric pain was the main reason for the endoscopic investigation. H. pylori infection over DGR did not influence the severity of endoscopic or premalignant gastric lesion development. Furthermore, smoking is directly related to immunohistochemically assessed active H. pylori infection in patients with bile reflux.

Role of Multimodality Imaging in Gastroesophageal Reflux Disease and Its Complications, with Clinical and Pathologic Correlation

Gastroesophageal reflux disease (GERD) is a common condition and impairs the quality of life for millions of patients, accounts for considerable health care spending, and is a primary risk factor for esophageal adenocarcinoma. There have been substantial advances in understanding the pathogenesis of GERD and its complications and much progress in diagnosis and management of GERD; however, these have not been comprehensively discussed in the recent radiology literature. Understanding the role of imaging in GERD and its complications is important to aid in multidisciplinary treatment of GERD. GERD results from prolonged or recurrent reflux of gastric contents into the esophagus. Common symptoms include heartburn or regurgitation. Prolonged reflux of gastric contents into the esophagus can cause erosive esophagitis. Over time, the inflammatory response related to esophagitis can lead to deposition of fibrous tissue and development of strictures. Alternatively, the esophageal mucosa can undergo metaplasia (Barrett esophagus), a precursor to dysplasia (which can lead to adenocarcinoma). Conventional barium esophagography has long been considered the primary imaging modality for the esophagus, and the fluoroscopic findings for diagnosis of GERD have been well established. Multimodality imaging has a clear role in detection and assessment of the complications of GERD, specifically reflux esophagitis and Barrett esophagus; differentiation of benign and malignant strictures; and detection, staging, and posttreatment surveillance of esophageal adenocarcinoma. Given the dramatic changes in utilization of abdominal imaging during the past 2 decades, with significantly declining volume of fluoroscopic procedures and concomitant increase in CT and MRI studies, it is crucial that modern radiologists appreciate the value of barium esophagography in the workup of GERD and recognize the key imaging features of GERD and its complications at CT and MRI.

Optimal management of severe symptomatic gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disorder, and empirical proton pump inhibitor (PPI) treatment is often the first step of management; however, up to 40% of patients remain symptomatic despite PPI treatment. Refractory reflux refers to continued symptoms despite an adequate trial of PPI, and management remains challenging. The differential diagnosis is important; other oesophageal (e.g. eosinophilic oesophagitis) and gastroduodenal disorders (e.g. functional dyspepsia) should be ruled out, as this changes management. A combination of clinical assessment, endoscopic evaluation and in selected cases oesophageal function testing can help characterize patients with refractory reflux symptoms into oesophageal phenotypes so appropriate therapy can be more optimally targeted. Medical options then may include adding a H2 receptor antagonist, alginates, baclofen or antidepressant therapy, and there is emerging evidence for bile acid sequestrants and diaphragmatic breathing. The demonstration of a temporal association of symptoms with reflux events on pH-impedance testing (reflux hypersensitivity) serves to focus the management on modulating oesophageal perception and reducing the reflux burden, or identifies those with no obvious pathophysiologic abnormalities (functional heartburn). Anti-reflux surgery based on randomized controlled trial evidence has a role in reflux hypersensitivity or continued pathological acid reflux despite PPI in carefully considered, fully worked up cases that have failed medical therapy; approximately two of three cases will respond but there is a small risk of complications. In patients with persistent volume reflux despite medical therapy, given the lack of alternatives, anti-reflux surgery is a consideration. Promising newer approaches include endoscopic techniques. This review aims to summarize current diagnostic approaches and critically evaluates the evidence for the efficacy of available treatments.

Expression of FFAR3 and FFAR4 Is Increased in Gastroesophageal Reflux Disease

Background: The negative impact of a high-fat diet on the course of gastroesophageal reflux disease (GERD) has been previously reported. Free fatty acid receptors (FFARs) may be mediators of this phenomenon. The aim of this study was to characterize the role of FFARs in the course of nonerosive (NERD) and erosive (ERD) reflux disease. Methods: Collectively, 73 patients (62 with GERD and 11 healthy controls (HCs)) were recruited to the study. Esophageal biopsies were drawn from the lower third of the esophagus and kept for further experiments. Quantitative, real-time polymerase chain reaction was used to assess the expression of FFAR1, FFAR2, FFAR3, and FFAR4 in biopsies. Histological evaluation of dilated intracellular spaces (DISs) was also performed. Results: FFAR3 exhibited the highest expression, and FFAR4 exhibited the lowest expression in all esophageal samples. Higher relative expression of FFAR1 and FFAR2 and significantly higher expression of FFAR3 (p = 0.04) was noted in patients with GERD compared to respective HCs. Patients with nonerosive GERD (NERD) presented higher expression of all FFARs compared to patients with erosive GERD (ERD) and respective HCs. Interestingly, in patients with ERD, the expression of FFAR3 was lower than in HCs. Significant, weak, positive correlation was found for FFAR3 and FFAR4 expression and DIS scores (r = 0.36, p < 0.05 for FFAR 3, and r = 0.39, p < 0.05 for FFAR4). Conclusions: In this study, we show that FFARs may play a role in GERD pathogenesis, particularly in the NERD type. It may be assumed that FFARs, in particular FFAR3 and FFAR4, may have diagnostic and therapeutic potential in GERD.

Bidirectional association between GERD and rheumatoid arthritis: two longitudinal follow-up studies using a national sample cohort

Several previous studies have suggested a relationship between GERD and RA. However, no study has investigated the bidirectional relationship between GERD and RA. This study aimed to evaluate the causal relationships between rheumatoid arthritis (RA) and gastroesophageal reflux disease (GERD). Participants aged ≥ 20 years old in the Korean Health Insurance Review and Assessment Service-National Sample Cohort from 2002 to 2013 were enrolled. In study I, 132,140 GERD participants were 1:2 matched with 264,280 control I participants. In study II, 6615 RA participants were 1:4 matched with 26,460 control II participants. Both control I and control II groups were matched with their study groups for age, sex, income, and region of residence. The occurrence of RA (study I) and GERD (study II) were followed up in both the study and control groups. The hazard ratios (HRs) of GERD for RA (study I) and of RA for GERD (study II) were analysed using stratified Cox-proportional hazards models. In study I, 0.8% (1,034/132,140) of the GERD group and 0.5% (1,290/264,280) of the control I group had RA (P < 0.001). The GERD group demonstrated a 1.49-fold higher adjusted HR than did the control I group (95% confidence interval (95% CI) = 1.37-1.62, P < 0.001). In study II, 22.5% (1,490/6,615) of the RA group and 15.2% (4,034/26,460) of the control II group had GERD (P < 0.001). The RA group showed a 1.46-fold higher adjusted HR than did the control II group (95% CI = 1.38-1.55, P < 0.001). GERD and RA have bidirectional associations in Korean adult population. Key Points • Several previous studies have suggested a relationship between gastroesophageal reflux disease (GERD) and rheumatoid arthritis (RA). • However, no study has investigated the bidirectional relationship between GERD and RA. • This is the first study to present a bidirectional relationship between GERD and RA. • GERD and RA have bidirectional relations with each other.

Esophageal Microenvironment: From Precursor Microenvironment to Premetastatic Niche

Esophageal cancer (EC) is the sixth most deadly cancer, and its incidence is still increasing year by year. Although the researches on the molecular mechanisms of EC have been widely carried out and incremental progress has been made, its overall survival rate is still low. There is cumulative evidence showing that the esophageal microenvironment plays a vital role in the development of EC. In precancerous lesions of the esophagus, high-risk environmental factors can promote the development of precancerous lesions by inducing the production of inflammatory factors and the recruitment of immune cells. In the tumor microenvironment, tumor-promoting cells can inhibit anti-tumor immunity and promote tumor progression through a variety of pathways, such as bone marrow-derived suppressor cells (MDSCs), tumor-associated fibroblasts (CAFs), and regulatory T cells (Tregs). The formation of extracellular hypoxia and acidic microenvironment and the change of extracellular matrix stiffness are also important factors affecting tumor progression and metastasis. Simultaneously, primary tumor-derived cytokines and bone marrow-derived immune cells can also promote the formation of pre-metastasis niche of EC lymph nodes, which are beneficial to EC lymph node metastasis. Further research on the specific mechanism of these processes in the occurrence, development, and metastasis of each EC subtype will support us to grasp the overall pre-cancerous prevention, targeted treatment, and metastatic assessment of EC.

Tojapride Reverses Esophageal Epithelial Inflammatory Responses on Reflux Esophagitis Model Rats

OBJECTIVE

To investigate the mechanism of Tojapride, a Chinese herbal formula extract, on strengthening the barrier function of esophageal epithelium in rats with reflux esophagitis (RE).

METHODS

Ten out of 85 SD rats were randomly selected as the sham group (n10), and 75 rats were developed a reflux esophagitis model (RE) by the esophageal and duodenal side-to-side anastomosis. Fifty successful modeling rats were divided into different medicated groups through a random number table including the model, low-, medium-, and high-dose of Tojapride as well as omeprazole groups (n10). Three doses of Tojapride [5.73, 11.46, 22.92 g/(kg•d)] and omeprazole [4.17 mg/(kg•d)] were administrated intragastrically twice daily for 3 weeks. And the rats in the sham and model groups were administered 10 mL/kg distilled water. Gastric fluid was collected and the supernatant was kept to measure for volume, pH value and acidity. Esophageal tissues were isolated to monitor the morphological changes through hematoxylin-eosin (HE) staining, and esophageal epithelial ultrastructure was observed by transmission electron microscopy. The expressions of nuclear factor kappa-light-chain-enhancer of activated B cells p65 (NF-KBp65), κB kinase beta (IKKß), occludin, and zonula occludens-1 (ZO-1) in the esophageal tissues were measured by immunohistochemistry and Western blot, respectively.

RESULTS

The gastric pH value in the model group was significantly lower than the sham group (P<0.05). Compared with the model group, gastric pH value in the omeprazole and medium-dose of Tojapride groups were significantly higher (P<0.05). A large area of ulceration was found on the esophageal mucosa from the model rats, while varying degrees of congestion and partially visible erosion was observed in the remaining groups. Remarkable increase in cell gap width and decrease in desmosome count was seen in RE rats and the effect was reversed by Tojapride treatment. Compared with the sham group, the IKKß levels were significantly higher in the model group (P<0.05). However, the IKKß levels were down-regulated after treatment by all doses of Tojapride (P<0.01 or P<0.05). The occluding and ZO-1 levels decreased in the model group compared with the sham group (Ps0.01 or Ps0.05), while both indices were significantly up-regulated in the Tojapride-treated groups (P<0.01 or P<0.05).

CONCLUSIONS

Tojapride could improve the pathological conditions of esophageal epithelium in RE rats. The underlying mechanisms may involve in down-regulating the IKKß expression and elevating ZO-1 and occludin expression, thereby alleviating the inflammation of the esophagus and strengthening the barrier function of the esophageal epithelium.

The potential role of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, but its pathogenesis is multifactorial. Although gastric acid secretion is usually normal in GERD patients, treatment with proton pump inhibitors (PPIs) has become the standard of care, despite increasing awareness of their shortcomings. In this article, a new class of antisecretory drugs (namely potassium-competitive acid blockers, P-CABs), developed to overcome these limitations, is discussed.

RECENT FINDINGS

P-CABs block the K exchange channel of the proton pump, resulting in rapid, competitive, reversible inhibition of acid secretion. These drugs offer a more rapid elevation of intragastric pH than PPIs, while maintaining similar antisecretory effect, the duration of which is dependent on half-life and can be prolonged with extended release formulations. Thus, P-CABs offer advances in the treatment of GERD including rapid heartburn relief, faster and more reliable healing of severe grades of erosive esophagitis, as a consequence of better control of nighttime acid secretion than PPIs.

SUMMARY

P-CABs overcome many of the drawbacks of PPIs. The unique antisecretory effects of vonoprazan might be especially useful in the long-term treatment of patients with Barrett's esophagus.

Perspectives on the interlinked nature of systemic sclerosis and reflux disease

Systemic sclerosis (SSc) is a multisystem connective tissue disease, characterized by chronic inflammation and vascular changes that result in esophageal smooth muscle atrophy and fibrosis. Subsequent progressive loss of peristalsis in the distal esophagus and loss of lower esophageal sphincter function lead to problems with the protective barrier and exposure of sensitive tissues to the gastroduodenal contents, a disorder called reflux disease. Areas covered: Depending on the range, nature and symptoms of the disease, the term 'reflux disease' may refer to gastroesophageal reflux, laryngopharyngeal reflux, microaspiration into the airways and silent reflux. Despite the links between these visceral complications, this connection remains controversial. This is due to a lack of complete understanding, the asymptomatic nature of the disease and the limited diagnostic accuracy of tests, which can delay diagnosis. Such delays are problematic, given that the early detection of GERD in SSc patients, the timing of assessment, the treatment of the organs involved are critical aspects of patient prognosis and disease outcome. Expert commentary: This review summarizes the most recent knowledge about the pathophysiology, diagnosis and prospective treatment of GERD in SSc patients and highlights how innovative technologies applied through an integrative, interdisciplinary approach may soon lead to effective treatment strategies.

Rat astrocytes during anoxia: Secretome profile of cytokines and chemokines

INTRODUCTION

The precise mechanisms of the inflammatory responses after cerebral ischemia in vivo are difficult to elucidate because of the complex nature of multiple series of interactions between cells and molecules. This study explored temporal patterns of secretion of 30 cytokines and chemokines from Sprague Dawley rat astrocytes in primary culture in order to elucidate signaling pathways that are triggered by astrocytes during anoxia.

METHODS

Primary cultures of rat brain astrocytes were incubated for periods of 2-24 hr in the absence of oxygen (anoxia) or under normal partial pressure of oxygen (controls). Simultaneous detection of 29 cytokines and chemokines in the samples was performed using a rat cytokine array panel, while the temporal pattern of angiopoietin-1 (Ang-1) secretion was determined separately using ELISA. Wilcoxon-Mann-Whitney test was used to compare normoxic and anoxic samples and the Hodge-Lehman estimator with exact 95% confidence intervals was computed to assess the size of differences in cytokine secretion. The obtained data were imported into the Core Analysis tool of Ingenuity Pathways Analysis software in order to relate changes in secretion of cytokines and chemokines from astrocytes during anoxia to potential molecular signal networks.

RESULTS

With the exception of Ang-1, concentrations of all cytokines/chemokines in samples collected after anoxia exposure were either the same, or higher, than in control groups. No clear pattern of changes could be established for groups of cytokines with similar effects (i.e., pro- or anti-inflammatory cytokines). The pattern of changes in cytokine secretion during anoxia was associated with the HIF-1α-mediated response, as well as cytokines IL-1β and cathepsin S pathways, which are related to initiation of inflammation and antigen presentation, respectively, and to ciliary neurotrophic factor.

CONCLUSIONS

These in vitro findings suggest that astrocytes may play a role in triggering inflammation during anoxia/ischemia of the brain.