Role of caspase-3/E-cadherin in helicobacter pylori-induced apoptosis of gastric epithelial cells

Hyperoside Alleviates Helicobacter pylori-Induced Gastric Epithelial Cell Injury by Regulating Nrf2/HO-1 Signaling

Infection with Helicobacter pylori is the major causative factor of chronic gastritis, peptic ulcer, gastric cancer, and other diseases. Gastric mucosal epithelial injury characterized by abnormal apoptosis, oxidative stress, and inflammation is a crucial mechanism of H. pylori infection. Hyperoside (HYP) is a flavonol glycoside derived from many herbal plants, which exhibits potent anti-apoptotic, antioxidant, and anti-inflammatory properties. Our research explored whether it exerts protective effects on H. pylori-infected human gastric epithelial cells. GES-1 cells were first treated for 24 h with HYP (0, 10, 20, 40, 80, 100, or 120 μM) to determine the cytotoxicity of HYP. Subsequently, GES-1 cells were pre-treated for 4 h with HYP (80 μM), followed by exposure to H. pylori for 24 h. CCK-8 assay, flow cytometry assay, ELISA, RT-qPCR, DCFH-DA staining, the commercial assay kits, immunofluorescence staining, and western blotting were used to assess cell viability, cell apoptosis, pro-inflammatory cytokine levels, oxidative stress marker levels, and Nrf2/HO-1 signaling-related molecule levels. The Nrf2 inhibitor ML385 was employed to verify the beneficial role of Nrf2 activation in HYP-mediated GES-1 cell injury induced by H. pylori. The results showed that HYP pre-treatment reversed H. pylori-induced cell apoptosis, inflammation, and oxidative stress in GES-1 cells. Furthermore, HYP downregulated Nrf2, HO-1, and NQO1 protein levels in H. pylori-infected GES-1 cells. ML385 overturned the protective effects of HYP against H. pylori-induced GES-1 cell apoptosis, inflammation, and oxidative stress. In conclusion, HYP protects gastric epithelial cells against H. pylori-induced cell injury by activating the Nrf2/HO-1 pathway.

Role of E-cadherin in epithelial barrier dysfunction: implications for bacterial infection, inflammation, and disease pathogenesis

Epithelial barriers serve as critical defense lines against microbial infiltration and maintain tissue homeostasis. E-cadherin, an essential component of adherens junctions, has emerged as a pivotal molecule that secures epithelial homeostasis. Lately, its pleiotropic role beyond barrier function, including its involvement in immune responses, has become more evident. Herein, we delve into the intricate relationship between (dys)regulation of epithelial homeostasis and the versatile functionality of E-cadherin, describing complex mechanisms that underlie barrier integrity and disruption in disease pathogenesis such as bacterial infection and inflammation, among others. Clinical implications of E-cadherin perturbations in host pathophysiology are emphasized; downregulation, proteolytic phenomena, abnormal localization/signaling and aberrant immune reactions are linked with a broad spectrum of pathology beyond infectious diseases. Finally, potential therapeutic interventions that may harness E-cadherin to mitigate barrier-associated tissue damage are explored. Overall, this review highlights the crucial role of E-cadherin in systemic health, offering insights that could pave the way for strategies to reinforce/restore barrier integrity and treat related diseases.

Unveiling the potential mechanisms of Amomi fructus against gastric ulcers via integrating network pharmacology and in vivo experiments

ETHNOPHARMACOLOGICAL RELEVANCE

As a well-known traditional Chinese medicine, Amomi fructus (A. fructus) (Sharen) has been used therapeutically to treat gastrointestinal illnesses, including gastric ulcer (GU). The mechanism underlying this impact is still not fully known, though.

AIM OF THE STUDY

To investigate the hidden mechanism by which A. fructus influences the pathogenesis of GU, we employed network pharmacology approaches and in vivo validated studies.

MATERIALS AND METHODS

Multiple public databases were used to compile information on bioactive compounds, potential targets of A. fructus, and associated genes of GU. Then, the STRING database's protein-protein interaction (PPI) data of the drug-disease overlapping gene targets was obtained, and the core targets for A. fructus against GU were discovered. Additionally, molecular docking was done to examine the binding capabilities of the active substances and core targets. Then, the pathways of A. fructus that target GU were examined using the Annotation, Visualization and Integrated Discovery (DAVID)'s Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway studies. In a mouse model of acute stomach mucosal damage brought on by absolute ethanol, the findings of network pharmacology were finally validated.

RESULTS

In total, 610 targets derived from the 196 bioactive compounds in A. fructus, were discovered, and along with 115 A. fructus target genes for therapy of GU. Then, ten core targets associated with apoptosis and inflammation were determined based on node degree, and ALB, AKT1, TNF, EGFR, MAPK3, CASP3, MMP9, STAT3, SRC, and HRAS were identified as promising therapeutic targets of A. fructus against GU. The results of molecular docking also revealed that 65 active compounds had strong binding activity with the core targets, with volatile chemicals being the most significant active ingredients. So, for following in vivo tests, A. fructus volatile oils (AVO) were used. The KEGG analysis showed that the phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) signaling pathway may be crucial for the therapeutic mechanism of GU. In experiments that were validated in vivo, AVO considerably decreased the ulcer area and enhanced the histological appearance of the gastric tissues. In addition, compared to the model group, up-regulated the expression of IGF-1, p-PI3K, and p-AKT and down-regulated the protein levels of TNF-α and Caspase 3 in the stomach tissues.

CONCLUSION

According to preliminary findings from this work, A. fructus may influence inflammatory response and apoptosis via regulating the PI3K/AKT signaling pathway and associated gene targets. Importantly, our research might offer a theoretical foundation for future research into the intricate anti-GU mechanism of A. fructus.

The Effects of Helicobacter pylori-Derived Outer Membrane Vesicles on Hepatic Stellate Cell Activation and Liver Fibrosis In Vitro

INTRODUCTION

Helicobacter pylori is a prevalent pathogenic bacterium that resides in the human stomach. Outer membrane vesicles (OMVs) are known as nanosized cargos released by H. pylori, which have been proposed to have a key role in disease progression, pathogenesis, and modulation of the immune system. There are multiple evidences for the role of H. pylori in extragastroduodenal illnesses especially liver-related disorders. However, the precise mechanism of H. pylori extragastroduodenal pathogenesis still remains unclear. In the current study, we aimed to determine the impact of H. pylori-isolated OMVs on hepatic stellate cell (HSC) activation and expression of liver fibrosis markers.

MATERIALS AND METHODS

Five H. pylori clinical strains with different genotype profiles were used. Helicobacter pylori OMVs were isolated using ultracentrifugation and were analyzed by scanning electron microscopy (SEM) and dynamic light scattering (DLS). Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis was applied to determine protein components of H. pylori-derived OMVs. Cell viability of LX-2 human hepatic stellate cell line exposed to OMVs was measured by MTT assay. LX-2 cells were treated with OMVs for 24 h. The gene expression of α-SMA, E-cadherin, vimentin, snail, and β-catenin was analyzed using quantitative real-time PCR. The protein expression of α-SMA, as a well-studied profibrotic marker, was evaluated with immunocytochemistry.

RESULTS

Our results showed that H. pylori strains released round shape nanovesicles ranging from 50 to 500 nm. Totally, 112 various proteins were identified in OMVs by proteomic analysis. The isolated OMVs were negative for both CagA and VacA virulence factors. Treatment of HSCs with H. pylori-derived OMVs significantly increased the expression of fibrosis markers.

CONCLUSIONS

In conclusion, the present study demonstrated that H. pylori-derived OMVs could promote HSC activation and induce the expression of hepatic fibrosis markers. Further research is required to elucidate the definite role of H. pylori-derived OMVs in liver fibrosis and liver-associated disorders.

Basic Traditional Chinese Medicinal Compound for Adjuvant Treatment of Helicobacter pylori-Related Gastritis: Implication for Anti-H. pylori-Related Gastritis Drug Discovery

This study was aimed at evaluating the efficacy of traditional Chinese medicine (TCM) in the adjuvant treatment of Helicobacter pylori-associated gastritis (HPAG) and exploring the molecular mechanism underlying the action of the basic TCM compounds against HPAG. Eight representative Chinese and British databases were combed for pertinent literature. In light of the basic principle of evidence-based medicine, this work rigorously stuck to the inclusion and exclusion of criteria so as to plump for qualified articles. Also, the data mining method was adopted to help determine the basic TCM compound for HPAG treatment. Furthermore, a network pharmacology-based strategy was used to uncover the underlying mechanisms of the basic TCM compound against HPAG. Ultimately, molecular docking was used for preliminary verification. TCM combined with triple or quadruple therapy against HPAG possessed more advantages in improving the total effective rate and H. pylori eradication rate than triple or quadruple therapy alone. The basic TCM plant materials against HPAG consisted of Citrus reticulata Blanco, Glycyrrhiza uralensis Fisch, Pinellia ternata (Thunb.) Breit, Coptis chinensis Franch, and Poria cocos (Schw.) Wolf. Quercetin, kaempferol, naringenin, baicalein, nobiletin, and hederagenin were determined as the key active ingredients of the basic TCM preparation against HPAG. Moreover, these ingredients played a therapeutic role by acting on AKT1, TP53, interleukin (IL)-6, VEGFA, CASP3, MAPK3, JUN, TNF, and MAPK8 via Pathways in cancer, PI3K-Akt signaling pathway, TNF signaling pathway, and MAPK signaling pathway. The results of molecular docking indicated that the key ingredients could bind stably with the core targets. The efficacy of the TCM in the adjuvant treatment of HPAG is worthy of affirmation. Compatible use of the key ingredients of the basic TCM compound is a novel idea of drug research with profound clinical significance and research value in the development of anti- H. pylori drugs.

Proteolytic Landscapes in Gastric Pathology and Cancerogenesis

Gastric cancer is a leading cause of cancer-related death, and a large proportion of cases are inseparably linked to infections with the bacterial pathogen and type I carcinogen Helicobacter pylori. The development of gastric cancer follows a cascade of transformative tissue events in an inflammatory environment. Proteases of host origin as well as H. pylori-derived proteases contribute to disease progression at every stage, from chronic gastritis to gastric cancer. In the present article, we discuss the importance of (metallo-)proteases in colonization, epithelial inflammation, and barrier disruption in tissue transformation, deregulation of cell proliferation and cell death, as well as tumor metastasis and neoangiogenesis. Proteases of the matrix metalloproteinase (MMP) and a disintegrin and metalloproteinase domain-containing protein (ADAM) families, caspases, calpain, and the H. pylori proteases HtrA, Hp1012, and Hp0169 cleave substrates including extracellular matrix molecules, chemokines, and cytokines, as well as their cognate receptors, and thus shape the pathogenic microenvironment. This review aims to summarize the current understanding of how proteases contribute to disease progression in the gastric compartment.

Investigating Helicobacter pylori-related pyloric hypomotility: functional, histological, and molecular alterations

Multiple theories have been proposed describing the pathogenic mechanisms of Helicobacter pylori (H. pylori)-associated gastric motility disorders. We assessed ex vivo pyloric activity in H. pylori-infected rats, and tried to explore the associated ghrelin hormone alteration and pyloric fibrogenesis. In addition, miR-1 was assessed in pyloric tissue samples, being recently accused of having a role in smooth muscle dysfunction. Ninety adult male Wistar albino rats were assigned into nine groups: 1) control group, 2) sterile broth (vehicle group), 3) amoxicillin control, 4) omeperazole control, 5) clarithromycin control, 6) triple therapy control, 7) H. pylori- group, 8) H. pylori-clarithromycin group, and 9) H. pylori-triple therapy group. Urease enzyme activity was applied as an indicator of H. pylori infection. Ex vivo pyloric contractility was evaluated. Serum ghrelin was assessed, and histological tissue evaluation was performed. Besides, pyloric muscle miR-1 expression was measured. The immunological epithelial to mesenchymal transition (EMT) markers; transforming growth factor β (TGFβ), α-smooth muscle actin (α-SMA), and E-cadherin-3 were also evaluated. By H. pylori infection, a significant (P < 0.001) reduced pyloric contractility index was recorded. The miR-1 expression was decreased (P < 0.001) in the H. pylori-infected group, associated with reduced serum ghrelin, elevated TGFβ, and α-SMA levels and reduced E-cadherin levels. Decreased miR-1 and disturbed molecular pattern were improved by treatment. In conclusion, H. pylori infection was associated with reduced miR-1, epithelial to mesenchymal transition, and pyloric hypomotility. The miR-1 may be a target for further studies to assess its possible involvement in H. pylori-associated pyloric dysfunction, which might help in the management of human H. pylori manifestations and complications.NEW & NOTEWORTHY This work is investigating functional, histopathological, and molecular changes underlying Helicobacter pylori hypomotility and is correlating these with miR-1, whose disturbance is supposed to be involved in smooth muscle dysfunction and cell proliferation according to literature. Epithelial to mesenchymal transition and reduced ghrelin hormone may contribute to H. pylori infection-associated hypomotility. H. pylori infection was associated with reduced pyloric miR-1 expression. Targeting miR-1 could be valuable in the clinical management of pyloric hypofunction.

Porphyromonas gingivalis lipopolysaccharide affects oral epithelial connections via pyroptosis

Background/purpose

Pyroptosis is a form of programmed cell death dependent on the activation of caspase-1. Porphyromonas gingivalis (P. gingivalis) is a major pathogenic bacterium in periodontitis and its lipopolysaccharide (LPS) can trigger inflammation. However, whether P. gingivalis-LPS affects epithelial connections or triggers pyroptosis in the gingival epithelium is unknown.

Materials and methods

Gingival samples from human donors were collected and the expression levels of E-cadherin, nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), caspase-1/4/5, interleukin (IL)-18, and IL-1β were examined. P. gingivalis-LPS was injected into rat gingival sulcus to establish gingivitis models, and the expression levels of E-cadherin, NLRP3, caspase-1/11, IL-18, and IL-1β were compared via immunohistochemistry. The mRNA levels of E-cadherin, caspase-1, IL-18, and IL-1β were evaluated in oral mucosa epithelial cells (OMECs) and rat gingival tissues.

Results

In the present study, NLRP3 (p < 0.01), caspase-1 (p < 0.01), caspase-4 (p = 0.044), and IL-18 (p = 0.036) expression was greater in the human inflammatory gingival samples, whereas E-cadherin (p = 0.045) had the opposite presentation. Gingivitis models were successfully established in rats with the injection of P. gingivalis-LPS. NLRP3 (p = 0.015), caspase-1 (p < 0.01), caspase-11 (p < 0.01), and IL-18 (p = 0.041) were upregulated, whereas E-cadherin (p = 0.038) expression was decreased. Furthermore, E-cadherin mRNA was decreased while caspase-1, IL-18, and IL-1β mRNA levels were increased. The addition of a caspase-1 inhibitor reversed the expression changes.

Conclusion

P. gingivalis-LPS may effectively destroy the epithelial connection by triggering pyroptosis.

Ligustrazine Attenuates Gastric Inflammation and Apoptosis in Helicobacter pylori-induced Gastric Epithelial Cells

Background: Stomach disorders, including gastric cancer and gastritis, are associated with the pathogenic bacterium Helicobacter pylori. Enhanced inflammation is the characteristic of H. pylori-induced gastritis. Ligustrazine exerts anti-inflammatory properties in mouse asthma models and acute kidney injury. Objectives: To determine the role of ligustrazine in H. pylori-induced gastritis. Methods: Normal gastric epithelial cell line (GES-1) was cultured with H. pylori at a multiplicity of infection (MOI) of 100: 1 for 24 hours. GES-1 cell line under H. pylori condition was incubated with 100 or 200 μM ligustrazine for 24 hours. Cell viability and apoptosis were investigated by MTT and flow cytometry assays, respectively. Inflammation was assessed by determining the levels and mRNA expression of interleukins (IL)-6/8, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein 1 (MCP-1) using ELISA and qRT-PCR analysis, respectively. Results: Helicobacter pylori infection reduced the viability and promoted the apoptosis of GES-1 cell line, accompanied by the enhanced activities of caspases 3 and 9. However, ligustrazine reversed the H. pylori-induced infection decreased viability, while increased apoptosis and caspases 3/9 activities in GES-1 cell line. Moreover, ligustrazine attenuated H. pylori-induced secretions of pro-inflammatory factors, IL-6/8, TNF-α, and MCP-1, in GES-1 cell line. The protein expression of inhibitor of NF-κB (IκBα) was downregulated in GES-1 cell line after H. pylori infection, while the protein expression levels of p65 and phosphorylation of IκBα were upregulated by H. pylori infection. On the contrary, ligustrazine decreased H. pylori-induced protein expression of IκBα, whereas increased protein expression of p65 and phosphorylation of IκBα. Conclusions: Ligustrazine exerted protective effects on H. pylori-induced gastric epithelial cells through inhibition of gastric inflammation and apoptosis and inactivation of NF-κB pathway.

Laryngeal Helicobacter pylori Infection and Laryngeal Cancer-Case Series and a Systematic Review

Helicobacter pylori (H. pylori) infection involves the development of gastric cancer and may be associated with laryngeal cancer. However, laryngeal H. pylori infection in Taiwanese patients with newly diagnosed laryngeal cancer has not been reported. This study was aimed to investigate the possible association between laryngeal H. pylori infection and laryngeal cancer in Taiwan and perform a systematic review of previous reports in other countries. An analysis of 105 patients with laryngeal lesions found the positive rates of H. pylori DNA (determined by polymerase chain reaction) and antigen (determined by immunohistochemistry) of the laryngeal lesions were relatively low (vocal polyps: 3% and 3%; vocal fold leukoplakia: 0% and 0%; laryngeal cancers: 0% and 2%). Furthermore, H. pylori-associated laryngopharyngeal reflux and the expression of E-cadherin and CD1d (determined by immunohistochemistry) were comparable among the three subgroups. Fifteen studies were involved in the systematic review of the digital literature database, distributed to February 2021. The data of patients with laryngeal cancer and controls showed that the laryngeal H. pylori infection rates were 29.4% and 16.7%, respectively. Although current evidence supported that laryngeal H. pylori infection was associated with laryngeal cancer globally, it might not play a role in the development of laryngeal cancer in Taiwan.

Analysis of Gene Expression of miRNA-106b-5p and TRAIL in the Apoptosis Pathway in Gastric Cancer

Helicobacter pylori (H. pylori) is one of the main causes of gastric gancer. TNF-related apoptosis-inducing ligand (TRAIL) is a protein able to promote apoptosis in cancer cells, however not in gastric cancer, which presents resistance to apoptosis via TRAIL. It is believed that MicroRNA-106b-5p might be involved in this resistance, although its role in Gastric Cancer is unclear. We aimed to determine the expression of microRNA-106b-5p and TRAIL in patients with gastric diseases, infected by H. pylori, and understand the relationship between these genes and their role in apoptosis and the gastric cancer pathways. H. pylori was detected by PCR, gene expression analysis was performed by real-time-qPCR, and bioinformatics analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cytoscape software. A total of 244 patients were divided into groups (Control, Gastritis, and Cancer); H. pylori was detected in 42.2% of the samples. The cancer group had a poor expression of TRAIL (p < 0.0001) and overexpression of microRNA-106b-5p (p = 0.0005), however, our results confirmed that these genes are not directly related to each other although both are apoptosis-related regulators. Our results also indicated that H. pylori decreases microRNA-106b-5p expression and that this is a carcinogenic bacterium responsible for gastric diseases.

Helicobacter pylori-downregulated tumor necrosis factor receptor-associated protein 1 mediates apoptosis of human gastric epithelial cells

Heat shock proteins (HSPs) are crucial proteins in maintaining the homeostasis of human gastric epithelial cells. Tumor necrosis factor receptor-associated protein 1 (TRAP1), a member of the HSP90 family, has been shown to be involved in various crucial physiological processes, particularly against apoptosis. However, the regulation and function of TRAP1 in Helicobacter pylori infection is still unknown. Here, we found that TRAP1 expression was downregulated on human gastric epithelial cells during H. pylori infection by real-time polymerase chain reaction (PCR) and western blot analysis. Through virulence factors mutant H. pylori strains infection and inhibitors screening, we found that H. pylori vacuolating cytotoxin A ( vacA), but not cytotoxin-associated gene A ( cagA) protein, induced human gastric epithelial cells to downregulate TRAP1 via P38MAPK pathway by real-time PCR and western blot analysis. Furthermore, downregulation of TRAP1 with lentivirus carrying TRAP1 short hairpin RNA constructs impairs mitochondrial function, and increases apoptosis of gastric epithelial cells. The results indicate that H. pylori vacA downregulated TRAP1 is involved in the regulation of gastric epithelial cell apoptosis.

Diffuse Gastric Cancer: A Summary of Analogous Contributing Factors for Its Molecular Pathogenicity

Gastric cancer is the third leading cause of cancer-related deaths and ranks as the fifth most common cancer worldwide. Incidence and mortality differ depending on the geographical region and gastric cancer ranks first in East Asian countries. Although genetic factors, gastric environment, and Helicobacter pylori infection have been associated with the pathogenicity and development of intestinal-type gastric cancer that follows the Correa's cascade, the pathogenicity of diffuse-type gastric cancer remains mostly unknown and undefined. However, genetic abnormalities in the cell adherence factors, such as E-cadherin and cellular activities that cause impaired cell integrity and physiology, have been documented as contributing factors. In recent years, H. pylori infection has been also associated with the development of diffuse-type gastric cancer. Therefore, in this report, we discuss the host factors as well as the bacterial factors that have been reported as associated factors contributing to the development of diffuse-type gastric cancer.