Rabeprazole inhibits inflammatory reaction by inhibition of cell pyroptosis in gastric epithelial cells

Fexuprazan safeguards the esophagus from hydrochloric acid-induced damage by suppressing NLRP1/Caspase-1/GSDMD pyroptotic pathway

Introduction

Proton pump inhibitors (PPIs) and potassium-competitive acid blockers (P-CABs) are widely used to manage gastric acid-related disorders by inhibiting hydrochloric acid (HCl) secretion from parietal cells in the stomach. Although PPIs are known to have anti-inflammatory properties beyond their role in inhibiting gastric acid secretion, research on P-CABs is lacking. In this study, we aimed to investigate whether all available P-CABs exhibit anti-inflammatory effects in gastroesophageal reflux-induced esophagitis and to elucidate the underlying mechanisms.

Methods

Het-1A cells, normal esophageal epithelial cells, were treated with HCl (pH 4) for 30 min. Esomeprazole, a representative PPI, and three currently marketed P-CABs (vonoprazan, tegoprazan, and fexuprazan) were used for pretreatment. Total RNA sequencing was performed using Het-1A cells pretreated with 1% DMSO or fexuprazan, followed by exposure to HCl. Pyroptosis was measured using lactate dehydrogenase (LDH) release and Annexin V-FITC/PI staining. Western blotting, qRT-PCR, and ELISA were used to determine the expression of the related genes.

Results

Pretreatment with esomeprazole, vonoprazan, tegoprazan, and fexuprazan significantly inhibited the HCl-induced pro-inflammatory cytokines, including IL-6, IL-8, IL-1β, and TNF-α. Fexuprazan and vonoprazan significantly attenuated the HCl-induced pyroptosis rate, as assessed by elevated LDH release and Annexin V-FITC/PI staining, whereas esomeprazole and tegoprazan did not. RNA sequencing revealed that NOD-like receptor (NLR) family pyrin domain-containing 1 (NLRP1) was significantly reduced in Het-1A cells pretreated with fexuprazan compared to those treated with DMSO. Fexuprazan and vonoprazan markedly reduced the HCl-induced transcriptional and translational expression of genes involved in the pyroptosis pathway, including NLRP1, Caspase-1, gasdermin D, and IL-1β. Notably, fexuprazan reduced the HCl-induced increase in pyroptosis and IL-1β using siRNA, even in the presence of NLRP1 knockdown. Fexuprazan, tested on inflammatory THP-1 macrophage cells, significantly reduced NLRP1 expression and inhibited lipopolysaccharide-induced pyroptosis.

Conclusion

Our findings reveal that all p-CABs exhibit anti-inflammatory properties, while fexuprazan inhibits inflammation and pyroptosis of esophageal cells caused by the gastric acid. Therefore, it is presumed to have additional benefits in gastroesophageal reflux disease in addition to suppressing gastric acid secretion.

Rabeprazole suppressed gastric intestinal metaplasia through activation of GPX4-mediated ferroptosis

Background

Gastric intestinal metaplasia is a common pathological feature in patients with Helicobacter pylori (H. pylori) infection. Rabeprazole was widely used as the first-line regimen for H. pylori infectious treatment. The objective of this study is to explore the mechanism of rabeprazole in gastric intestinal metaplasia treatment.

Methods

Real-time PCR, Western blotting (WB) and ROS analysis were conducted to confirm that rabeprazole could induce ferroptosis to suppress gastric intestinal metaplasia. Cellular fraction, luciferase and chromatin immunoprecipitation (ChIP) were used to identify the mechanism underlying rabeprazole modulated ferroptosis.

Results

Herein, we found rabeprazole treatment led to inhibit CDX2 and MUC2 expression, alleviating gastric intestinal metaplasia, which was attributed to enhanced ferroptosis characterized by decreased GPX4 expression. Inhibition of ferroptosis by ferrostatin-1 (Fer-1) could reverse decreased CDX2 and MUC2 expression caused by rabeprazole. Mechanically, Rabeprazole could inhibit CREB phosphorylation and nuclear translocation, which further decreased the binding of CREB to GPX4 promoter, reducing GPX4 transactivity. Moreover, endogenous PKA interacted with CREB, and this interaction was drastically destroyed in response to rabeprazole treatment. Most importantly, enhanced ferroptosis was observed in H. pylori-infected gastric intestinal metaplasia in comparison to HC control.

Conclusion

These findings suggested that rabeprazole induced ferroptosis to reduce CDX2 expression in gastric epithelial cells through PKA/CREB cascade signaling, implying that targeting ferroptosis could be a promising strategy in improving gastric intestinal metaplasia during H. pylori-infected patients.

Beyond Inflammation: Role of Pyroptosis Pathway Activation by Gram-Negative Bacteria and Their Outer Membrane Vesicles (OMVs) in the Interaction with the Host Cell

Pyroptosis is a gasdermin-mediated pro-inflammatory programmed cell death that, during microbial infections, aims to restrict the spreading of bacteria. Nevertheless, excessive pyroptosis activation leads to inflammation levels that are detrimental to the host. Pathogen-associated molecular patterns (PAMPs) present in bacteria and outer membrane vesicles (OMVs) can trigger pyroptosis pathways in different cell types with different outcomes. Moreover, some pathogens have evolved virulence factors that directly interfere with pyroptosis pathways, like Yersinia pestis YopM and Shigella flexneri IpaH7.8. Other virulence factors, such as those of Neisseria meningitidis, Neisseria gonorrhoeae, Salmonella enterica, and Helicobacter pylori affect pyroptosis pathways indirectly with important differences between pathogenic and commensal species of the same family. These pathogens deserve special attention because of the increasing antimicrobial resistance of S. flexneri and N. gonorrhoeae, the high prevalence of S. enterica and H. pylori, and the life-threatening diseases caused by N. meningitidis and Y. pestis. While inflammation due to macrophage pyroptosis has been extensively addressed, the effects of activation of pyroptosis pathways on modulation of cell cytoskeleton and cell-cell junctions in epithelia and endothelia and on the bacterial crossing of epithelial and endothelial barriers have only been partly investigated. Another important point is the diverse consequences of pyroptosis pathways on calcium influx, like activation of calcium-dependent enzymes and mitochondria dysregulation. This review will discuss the pyroptotic pathways activated by Gram-negative bacteria and their OMVs, analyzing the differences between pathogens and commensal bacteria. Particular attention will also be paid to the experimental models adopted and the main results obtained in the different models. Finally, strategies adopted by pathogens to modulate these pathways will be discussed with a perspective on the use of pyroptosis inhibitors as adjuvants in the treatment of infections.

Programmed cell death in Helicobacter pylori infection and related gastric cancer

Programmed cell death (PCD) plays a crucial role in maintaining the normal structure and function of the digestive tract in the body. Infection with Helicobacter pylori (H. pylori) is an important factor leading to gastric damage, promoting the Correa cascade and accelerating the transition from gastritis to gastric cancer. Recent research has shown that several PCD signaling pathways are abnormally activated during H. pylori infection, and the dysfunction of PCD is thought to contribute to the development of gastric cancer and interfere with treatment. With the deepening of studies on H. pylori infection in terms of PCD, exploring the interaction mechanisms between H. pylori and the body in different PCD pathways may become an important research direction for the future treatment of H. pylori infection and H. pylori-related gastric cancer. In addition, biologically active compounds that can inhibit or induce PCD may serve as key elements for the treatment of this disease. In this review, we briefly describe the process of PCD, discuss the interaction between different PCD signaling pathways and the mechanisms of H. pylori infection or H. pylori-related gastric cancer, and summarize the active molecules that may play a therapeutic role in each PCD pathway during this process, with the expectation of providing a more comprehensive understanding of the role of PCD in H. pylori infection.

Aloe vera gel confers therapeutic effect by reducing pyroptosis in ethanol-induced gastric ulcer rat model: Role of NLRP3/GSDMD signaling pathway

BACKGROUND

Gastric ulcer (GU) is a common gastrointestinal tract illness. Aloe vera has anti-inflammatory, antioxidant, and healing characteristics. This research sought to explore the therapeutic impact of Aloe vera gel on ethanol-provoked GU in rats and to elucidate the underlying mechanisms involved.

METHODS

An ethanol-induced GU rat model was constructed using forty male Wistar rats distributed at random into four groups: control, ulcer, pantoprazole, and Aloe vera. Gross evaluation of the stomach, ulcer index (UI), inhibition index, and gastric pH estimation were analyzed. Gastric malondialdehyde (MDA) and reduced glutathione (GSH) were determined using the spectrophotometric method, and serum gastrin level was measured by an enzyme-linked immunosorbent assay. Gastric nucleotide-binding domain, leucine-rich repeat, and pyrin domain PYD containing protein 3 (NLRP3) and gasdermin D (GSDMD) mRNA expression levels were estimated by quantitative real-time PCR. Finally, the histopathological examination of the glandular part of stomach tissue was done.

RESULTS

The ulcer group revealed a significant increase in MDA, gastrin, NLRP3, and GSDMD and a decrease in gastric pH and GSH compared to the control group. Gross investigations of the ulcer group revealed a hemorrhagic lesion in the stomach and an increase in UI. Also, histopathological results for this group showed severe epithelial loss, haemorrhage, inflammatory cell infiltration, and blood vessel congestion. However, Aloe vera treatment improved the gross, biochemical, molecular, and histopathological alterations induced by ethanol when compared to the ulcer group.

CONCLUSIONS

Aloe vera exerted antiulcer activities through modulation of oxidant/antioxidant status, anti-secretory properties, and mitigation of pyroptosis.

Application of pyroptosis score in the treatment and prognosis evaluation of gastric cancer

Pyroptosis is a kind of proinflammatory programmed cell death mediated by inflammasome. It affects the occurrence and development of gastric cancer through different ways, showing dual effects. On the one hand, inflammasome-mediated inflammatory response is highly likely to participate in the formation and development of early tumors; on the other hand, drugs can inhibit the deterioration process of tumor proliferation, invasion and metastasis through activating the pathways of inflammasome and pyroptosis. Recently, many agents based on pyroptosis have been found to inhibit gastric cancer by promoting the secondary pyroptosis pathway, regulating NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and inhibiting caspase-1. The establishment of cell pyrodeath models can predict the prognosis of gastric cancer patients. Most of the models show that gastric cancer patients with high pyroptosis level have better prognosis and longer overall survival. Pyroptosis scores can also be used to predict the response of gastric cancer patients to immunotherapy and to screen potential anti-gastric cancer drugs. Therefore, in-depth understanding of the potential mechanism of pyroptosis affecting the progression of gastric cancer and the role of pyroptosis score in the treatment and prognosis assessment of gastric cancer will be helpful to find a new and effective method for the treatment of gastric cancer.

Augmented nephroprotective effect of liraglutide and rabeprazole via inhibition of OCT2 transporter in cisplatin-induced nephrotoxicity in rats

AIMS

Cisplatin, a widely used anticancer treatment, has a marked nephrotoxic effect. This nephrotoxic effect is linked to the triggering of oxidative stress, inflammation, activation of mitogen-activated protein kinase (MAPK) pathway as well as apoptosis. The purpose of the present research was to examine the possible ameliorative effect of liraglutide and/or rabeprazole on cisplatin-induced nephrotoxicity in rats and to underline the potential molecular pathways involved.

MAIN METHODS

Rats were divided into five groups: Control, cisplatin, liraglutide (200 μg/kg/day, i.p), rabeprazole (10 mg/kg/day, orally) and liraglutide + rabeprazole combination groups. All treatments were given for 7 days. Cisplatin was given as a single dose (7 mg/kg, i.p) at day 4 to induce nephrotoxicity in all groups except the control group.

KEY FINDINGS

Treatment with liraglutide and/or rabeprazole prior to cisplatin maintained the function and morphology of kidney via decreasing cisplatin renal uptake by significant inhibition of OCT2. Besides, they showed a significant increase in GLP-1 receptor expression. Liraglutide and/or rabeprazole significantly attenuated the levels of TNF-α. ICAM, NF-κB, and downregulated MAPK pathway proteins such as JNK, and ERK1/2. Moreover, they maintained oxidant antioxidant balance by decreasing MDA level and increasing GSH level and CAT activity. Additionally, liraglutide and/or rabeprazole exhibited antiapoptotic effect evidenced by the decreased caspase-3 level and Bax expression and the increased Bcl-2 expression.

SIGNIFICANCE

The current study showed that both liraglutide and rabeprazole exerted a nephroprotective effect against cisplatin-induced renal toxicity in rats. Interestingly, co-treatment with both drugs showed an augmented effect.

NLRP3 inflammasome in digestive diseases: From mechanism to therapy

Digestive system diseases remain a formidable challenge to human health. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex and is involved in a wide range of digestive diseases as intracellular innate immune sensors. It has emerged as a research hotspot in recent years. In this context, we provide a comprehensive review of NLRP3 inflammasome priming and activation in the pathogenesis of digestive diseases, including clinical and preclinical studies. Moreover, the scientific evidence of small-molecule chemical drugs, biologics, and phytochemicals, which acts on different steps of the NLRP3 inflammasome, is reviewed. Above all, deep interrogation of the NLRP3 inflammasome is a better insight of the pathomechanism of digestive diseases. We believe that the NLRP3 inflammasome will hold promise as a novel valuable target and research direction for treating digestive disorders.

Candidate Drugs Screening for Behcet’s Disease Based on Bioinformatics Analysis and Mouse Experiments

Background

Behcet’s disease (BD) is a chronic immune disease that involves multiple systems. As the pathogenesis of BD is not clear, and new treatments are needed, we used bioinformatics to identify potential drugs and validated them in mouse models.

Methods

Behcet’s disease-related target genes and proteins were screened in the PubMed and UVEOGENE databases. The biological functions and pathways of the target genes were analyzed in detail by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein-protein interaction (PPI) network was constructed by the STRING database, and hub genes were identified by the Cytoscape plug-in CytoHubba. Gene-drug interactions were identified from the DGIdb database. Experimental autoimmune uveitis (EAU) mice were used as an animal model for drug validation.

Results

A total of 249 target genes and proteins with significant differences in BD were screened, and the results of functional enrichment analysis suggested that these genes and proteins were more located on the cell membrane, involved in regulating the production of cytokines and affecting the activity of cytokines. They mainly regulated “Cytokine- Cytokine receptor interaction”, “Inflammatory bowel disease (IBD)” and “IL-17 signaling Pathway”. In addition, 10 hub genes were obtained through PPI network construction and CytoHubba analysis, among which the top 3 hub genes were closely related to BD. The DGIdb analysis enriched seven drugs acting together on the top 3 hub genes, four of which were confirmed for the treatment of BD or its complications. There is no evidence in the research to support the results in omeprazole, rabeprazole, and celastrol. However, animal experiments showed that rabeprazole and celastrol reduced anterior chamber inflammation and retinal inflammation in EAU mice.

Conclusions

The functional analysis of genes and proteins related to BD, identification of hub genes, and validation of potential drugs provide new insights into the disease mechanism and potential for the treatment of BD.

Vitronectin, a Novel Urinary Proteomic Biomarker, Promotes Cell Pyroptosis in Juvenile Systemic Lupus Erythematosus

Objective

Identifying new markers of juvenile systemic lupus erythematosus (JSLE) is critical event to predict patient stratification and prognosis. The aim of the present study is to analyze alteration of urinary protein expression and screen potential valuable biomarkers in juvenile systemic lupus erythematosus (JSLE).

Methods

The urine was collected from the patients with or without JSLE and detected by mass spectrometry to analyze proteomic changes. ELISA was used to verify the Vitronectin (VTN) changes in a new set of patients. The clinical correlation was performed to analyze between VTN and clinical pathological parameters. WB and ELISA were used to analyze VTN-mediated cell pyroptosis.

Results

Herein, we have identified a group of 105 differentially expressed proteins with ≥1.3-fold upregulation or ≤0.77-fold downregulation in JSLE patients. These proteins were involved in several important biological processes, including acute phase inflammatory responses, complement activation, hemostasis, and immune system regulation through Gene Ontology and functional enrichment analysis. Interestingly, urinary ephrin type-A receptor 4 (EPHA4) and VTN were significantly reduced in both inactive and active JSLE patients, and VTN treatment in THP-1 derived macrophages led to a significant increased cell pyroptosis by activation of Nod-like receptor family protein 3 (NLRP3) inflammasomes, resulting in caspase-1 activation, cleaved gasdermin D (GSDMD), and IL-18 secretion. Most importantly, the urinary VTN was also linearly correlated with clinical characteristics of JSLE, implying that VTN could be a specific diagnostic biomarker to distinguish inactive and active JSLE.

Conclusion

This study provided a novel role of VTN in pyroptosis in JSLE through the urinary proteomic profile for JSLE, which could be a nonintrusive monitoring strategy in clinical diagnosis.