Gastric Epithelial Cells Research Articles

Exploring the anti-EBV potential of suberoylanilide hydroxamic acid: Induction of apoptosis in infected cells through suppressing BART gene expression and inducing lytic infection

Epstein-Barr virus (EBV) is linked to lymphoma and epithelioma but lacks drugs specifically targeting EBV-positive tumors. BamHI A Rightward Transcript (BART) miRNAs are expressed in all EBV-positive tumors, suppressing both lytic infection and host cell apoptosis. We identified suberoylanilide hydroxamic acid (SAHA), an inhibitor of histone deacetylase enzymes, as an agent that suppresses BART promoter activity and transcription of BART miRNAs. SAHA treatment demonstrated a more pronounced inhibition of cell proliferation in EBV-positive cells compared to EBV-negative cells, affecting both p53 wild-type and mutant gastric epithelial cells. SAHA treatment enhanced lytic infection in wild-type EBV-infected cells, while also enhancing cell death in BZLF1-deficient EBV-infected cells. It reduced BART gene expression by 85% and increased the expression of proapoptotic factors targeted by BART miRNAs. These findings suggest that SAHA not only induces lytic infection but also leads to cell death by suppressing BART miRNA transcription and promoting the apoptotic program.

Integrin-Linked Kinase in the Development of Gastric Tumors Induced by Helicobacter pylori: Regulation and Prevention Potential.

Integrin-linked kinase (ILK) is crucial in solid tumors by regulating the Hippo-Yes-associated protein 1 (YAP) pathway. This study aimed to uncover how Helicobacter pylori influences ILK levels and its role in regulating YAP during H. pylori-induced gastric cancer. GES-1 cells with stable Ilk knockdown and overexpression and a mouse carcinogenesis model for H. pylori infection were constructed. And ILK, the phosphorylated mammalian STE20-like protein kinase 1 (MST1), large tumor suppressor 1 (LATS1; S909, T1079), and YAP (S109, S127) were detected in cells, and mice by western blotting, as well as fluorescence intensity of YAP were assayed by immunofluorescence. YAP downstream genes Igfbp4 and Ctgf, the pathological changes and tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), interleukin-1beta (IL-1β), and nitric oxide (NO) levels in mice gastric tissues were detected by real-time PCR, H&E, and ELISA assays. In this study, stable Ilk knockdown cells exhibited significantly higher phosphorylated levels of MST1, LATS1, and YAP, as well as increased YAP in the nuclei of GES-1 cells. Conversely, cells with Ilk overexpression showed opposite results. H. pylori infection led to decreased ILK levels in gastric epithelial cells but increased ILK levels in gastric cancer cell lines (MGC803, SGC7901) and gastric cancer tissues in mice. Treatment with the ILK inhibitor OST-T315 elevated the phosphorylated MST, LATS1, and YAP levels, and inhibited the mRNA levels of Igfbp4 and Ctgf at 44, 48 week-aged mice. OST-T315 also reduced the release of TNF-α, IL-6, IL-1β, and NO, as well as the progression of gastric cancer caused by H. pylori and N-Nitroso-N-methylurea (NMU) treatment. Upon initiation of gastric tumorigenesis signals, H. pylori increases ILK levels and suppresses Hippo signaling, thereby promoting YAP activation and gastric cancer progression. ILK can serve as a potential prevention target to impede H. pylori-induced gastric cancer.

Synthesis, DFT, and in silico biological evaluation of chalcone bearing pyrazoline ring against Helicobacter pylori receptors

Peptic ulcer disease (PUD), often caused by Helicobacter pylori infection, is a prevalent gastrointestinal condition characterized by the erosion of the gastric or duodenal mucosal lining. H. pylori adheres to gastric epithelial cells, secreting toxins and disrupting the stomach's defenses. H. pylori relies on various receptors to establish infection, making these molecules attractive therapeutic targets. This study aimed to develop novel anti-ulcer compounds by combining benzothiazole, pyrazoline, and chalcone pharmacophores. A series of chalcone derivatives 4a-c were synthesized via Claisen-Schmidt condensation and characterized using spectroscopic techniques such as FT-IR, NMR and elemental analysis. The DFT calculations, using B3LYP method with 6-311G basis set, revealed the p-tolyl derivative 4b exhibited the highest thermal stability while the p-bromophenyl derivative 4c showed the lowest stability but highest chemical reactivity. The HOMO-LUMO energy gaps as well as the dipole moments decreased in the order: 4b > 4a >4c, reflecting a similar reactivity trend. Molecular docking showed ligands 4a-c bound effectively to the H. pylori urease enzyme, with docking scores from −5.3862 to −5.7367 kcal/mol with superior affinity over lansoprazole. Key interactions involved hydrogen bonds and hydrophobic pi-hydrogen bonds with distances ranging 3.46–4.34 Å with active site residues ASN666, SER714 and ASN810. The combined anti-inflammatory, antimicrobial, and H. pylori anti-adhesion properties make these novel chalcones promising PUD therapeutic candidates.

Antibacterial Activity of Korean Resource Plant Extracts against <i>Helicobacter pylori</i> and Inhibitory Effect of IL-8 Secretion in Gastric Epithelial Cells

Antibacterial Activity of Korean Resource Plant Extracts against <i>Helicobacter pylori</i> and Inhibitory Effect of IL-8 Secretion in Gastric Epithelial Cells

Helicobacter pylori-Induced Decrease in Membrane Expression of Na,K-ATPase Leads to Gastric Injury.

Helicobacter pylori is a highly prevalent human gastric pathogen that causes gastritis, ulcer disease, and gastric cancer. It is not yet fully understood how H. pylori injures the gastric epithelium. The Na,K-ATPase, an essential transporter found in virtually all mammalian cells, has been shown to be important for maintaining the barrier function of lung and kidney epithelia. H. pylori decreases levels of Na,K-ATPase in the plasma membrane of gastric epithelial cells, and the aim of this study was to demonstrate that this reduction led to gastric injury by impairing the epithelial barrier. Similar to H. pylori infection, the inhibition of Na,K-ATPase with ouabain decreased transepithelial electrical resistance and increased paracellular permeability in cell monolayers of human gastric cultured cells, 2D human gastric organoids, and gastric epithelium isolated from gerbils. Similar effects were caused by a partial shRNA silencing of Na,K-ATPase in human gastric organoids. Both H. pylori infection and ouabain exposure disrupted organization of adherens junctions in human gastric epithelia as demonstrated by E-cadherin immunofluorescence. Functional and structural impairment of epithelial integrity with a decrease in Na,K-ATPase amount or activity provides evidence that the H. pylori-induced downregulation of Na,K-ATPase plays a role in the complex mechanism of gastric disease induced by the bacteria.

HtrA-Dependent E-Cadherin Shedding Impairs the Epithelial Barrier Function in Primary Gastric Epithelial Cells and Gastric Organoids.

Impaired E-cadherin (Cdh1) functions are closely associated with cellular dedifferentiation, infiltrative tumor growth and metastasis, particularly in gastric cancer. The class-I carcinogen Helicobacter pylori (H. pylori) colonizes gastric epithelial cells and induces Cdh1 shedding, which is primarily mediated by the secreted bacterial protease high temperature requirement A (HtrA). In this study, we used human primary epithelial cell lines derived from gastroids and mucosoids from different healthy donors to investigate HtrA-mediated Cdh1 cleavage and the subsequent impact on bacterial pathogenesis in a non-neoplastic context. We found a severe impairment of Cdh1 functions by HtrA-induced ectodomain cleavage in 2D primary cells and mucosoids. Since mucosoids exhibit an intact apico-basal polarity, we investigated bacterial transmigration across the monolayer, which was partially depolarized by HtrA, as indicated by microscopy, the analyses of the transepithelial electrical resistance (TEER) and colony forming unit (cfu) assays. Finally, we investigated CagA injection and observed efficient CagA translocation and tyrosine phosphorylation in 2D primary cells and, to a lesser extent, similar effects in mucosoids. In summary, HtrA is a crucially important factor promoting the multistep pathogenesis of H. pylori in non-transformed primary gastric epithelial cells and organoid-based epithelial models.

Hypoxia exacerbates the malignant transformation of gastric epithelial cells induced by long-term H. pylori infection.

Helicobacter pylori is a microaerophilic Gram-negative bacterium that resides in the human stomach and is classified as a class I carcinogen for gastric cancer. Numerous studies have demonstrated that H. pylori infection plays a role in regulating the function of host cells, thereby contributing to the malignant transformation of these cells. However, H. pylori infection is a chronic process, and short-term cellular experiments may not provide a comprehensive understanding of the in vivo situation, especially when considering the lower oxygen levels in the human stomach. In this study, we aimed to investigate the mechanisms underlying gastric cell dysfunction after prolonged exposure to H. pylori under hypoxic conditions. We conducted a co-culture experiment using the gastric cell line GES-1 and H. pylori for 30 generations under intermittent hypoxic conditions. By closely monitoring cell proliferation, migration, invasion, autophagy, and apoptosis, we revealed that sustained H. pylori stimulation under hypoxic conditions significantly influences the function of GES-1 cells. This stimulation induces epithelial-mesenchymal transition and contributes to the propensity for malignant transformation of gastric cells. To confirm the in vitro results, we conducted an experiment involving Mongolian gerbils infected with H. pylori for 85 weeks. All the results strongly suggest that the Nod1 receptor signaling pathway plays a crucial role in H. pylori-related apoptosis and autophagy. In summary, continuous stimulation by H. pylori affects the functioning of gastric cells through the Nod1 receptor signaling pathway, increasing the likelihood of cell carcinogenesis. The presence of hypoxic conditions further exacerbates this process.IMPORTANCEDeciphering the collaborative effects of Helicobacter pylori infection on gastric epithelial cell function is key to unraveling the development mechanisms of gastric cancer. Prior research has solely examined the outcomes of short-term H. pylori stimulation on gastric epithelial cells under aerobic conditions, neglecting the bacterium's nature as a microaerophilic organism that leads to cancer following prolonged stomach colonization. This study mimics a more genuine in vivo infection scenario by repeatedly exposing gastric epithelial cells to H. pylori under hypoxic conditions for up to 30 generations. The results show that chronic exposure to H. pylori in hypoxia substantially increases cell migration, invasion, and epithelial-mesenchymal transition, while suppressing autophagy and apoptosis. This highlights the significance of hypoxic conditions in intensifying the carcinogenic impact of H. pylori infection. By accurately replicating the in vivo gastric environment, this study enhances our comprehension of H. pylori's pathogenic mechanisms in gastric cancer.

Lyophilized cell-free supernatants of Limosilactobacillus fermentum T0701 exhibited antibacterial activity against Helicobacter pylori

Helicobacter pylori is a prominent gastrointestinal pathogen associated with various gastrointestinal illnesses. It presents substantial health risks due to its antibiotic resistance. Therefore, it is crucial to identify alternative treatments for H. pylori infections. Limosilactobacillus spp exhibit probiotic properties with beneficial effects in humans; however, the mechanisms by which it counteracts H. pylori infection are unknown. This study aimed to evaluate the potential of Limosilactobacillus fermentum T0701 lyophilized cell-free supernatants (LCFS) against H. pylori. The LCFS has varying antimicrobial activities, with inhibition zones of up to 10.67 mm. The minimum inhibitory concentration and minimum bacterial concentration of LCFS are 6.25–25.00 mg/mL and 6.25 mg/mL to > 50.00 mg/mL, respectively, indicating its capability to inhibit H. pylori. There is morphological damage observed in H. pylori treated with LCFS. Additionally, H. pylori adhesion to AGS cells (human gastric adenocarcinoma epithelial cells) reduces by 74.23%, highlighting the LCFS role in preventing bacterial colonization. Moreover, LCFS exhibits no cytotoxicity or morphological changes in AGS cells, and with no detected virulence or antimicrobial resistance genes, further supporting its safety profile. L. fermentum T0701 LCFS shows promise as a safe and effective non-toxic agent against H. pylori, with the potential to prevent gastric colonization.

Astragaloside IV prevents enterovirus 71-induced pyroptosis through the TCF12-TXNIP-Keap1/Nrf2 axis

This study aimed to investigate the inhibitory effect of astragaloside IV (AS-IV) on enterovirus 71 (EV71)-induced pyroptosis. The results indicated that AST-IV inhibited EV71-induced pyroptosis in normal human gastric epithelial (GES-1) cells. Therefore, we investigated the mechanisms underlying pyroptosis inhibition by AST-IV. We found that EV71 inhibited the Nrf2-Keap1 pathway, whereas AST-IV treatment activated it. Overexpression of Nrf2 led to the inhibition of EV71-induced pyroptosis. EV71 infection and AST-IV treatment upregulated and downregulated thioredoxin interacting protein (TXNIP), respectively. Downregulation of TXNIP activated the Keap1/Nrf2 signaling pathway and inhibited EV71-induced pyroptosis. Furthermore, transcription factor 12 (TCF12) reduced the protein and mRNA levels of TXNIP, and AST-IV treatment upregulated TCF12. These results demonstrate that the TCF12-TXNIP-Keap1/Nrf2 axis participates in the inhibition of pyroptosis by AST-IV in EV71-infected GES-1 cells, suggesting that AST-IV could be used as a dietary supplement to alleviate EV71-induced pyroptosis.

Epithelial cell proliferation index in patients with atrophic gastritis depending on the presence of complete or incomplete intestinal metaplasia in the gastric antrum

Introduction. There is a debate about the significance of intestinal metaplasia (IM) subtypes for the development of gastric cancer. Therefore, determining the indicators of cellular renewal in individuals with complete and incomplete IM is certainly a topical issue.Aim. To study the proliferative activity of epithelial cells of the gastric antrum in patients with Helicobacter pylori-positive antral atrophic gastritis depending on the subtype of IM.Materials and methods. The study included 20 people with chronic antral non-atrophic gastritis (CNG; group A), 20 patients with chronic antral atrophic gastritis (CAG) without IM (group B), 20 patients with CAG with complete IM (group C) and 20 people with CAG with incomplete IM (group D). The stage of chronic gastritis was assessed by the morphological method in accordance with the modified Sydney classification. Typing of IM foci in the gastric mucosa was performed using the PAS reaction. Proliferation activity was studied by the expression of nuclear protein Ki67 using immunohistochemistry.Results. The proliferation index in the foci of complete BM in group C was 5%, and in group D in the foci of incomplete BM the Ki67 expression index was significantly higher and was 39% (p < 0.001). Outside the foci of metaplasia, the proliferation index was 23.5% in group C and 19% in group D (p = 0.06).Conclusion. We have registered significantly higher proliferation indicators of gastric epithelial cells in foci with incomplete IM compared to foci with complete IM. Determination of proliferation indicators in foci of incomplete intestinal metaplasia may be a marker of an increased risk of developing gastric cancer.

Exploring the therapeutic mechanisms of Coptidis Rhizoma in gastric precancerous lesions: a network pharmacology approach

BackgroundGastric precancerous lesions are a critical stage in the development of gastric cancer or gastric adenocarcinoma, and their outcome plays an important role in the malignant progression of gastric cancer. Coptidis Rhizoma has a good effect on Gastric precancerous lesions. However, the specific mechanisms of its action remain incompletely elucidated.MethodsNetwork pharmacology and molecular docking techniques were used to explore the active ingredients and molecular mechanism of Coptidis Rhizoma in treating gastric precancerous lesions. The active compounds of Coptidis Rhizoma and their potential gastric precancerous lesions related targets were obtained from TCMSP, GeneCards, and OMIM databases. An interaction network based on protein–protein interactions (PPIs) was constructed to visualize the interactions between hub genes. Analysis of GO enrichment and KEGG pathway were conducted using the DAVID database. An investigation of interactions between active compounds and potential targets was carried out by molecular docking. Finally, animal experiments were conducted to verify the effect and mechanism of Coptidis Rhizoma in treating precancerous lesions of gastric cancer.ResultsA total of 11 active compounds and 95 anti-gastric precancerous lesions targets of Coptidis Rhizoma were screened for analysis. GO enrichment analysis showed that the mechanism of Coptidis Rhizoma acting on gastric precancerous lesions involves gene expression regulation and apoptosis regulation. KEGG pathway enrichment analysis showed that Coptidis Rhizoma against gastric precancerous lesions involving the AKT /HIF-1α/VEGF signalling pathway. Molecular docking simulations indicated potential interactions between these compounds and core targets involved in anti-gastric precancerous lesions activity. In addition, it was confirmed in vivo that Berberine and Coptidis Rhizoma may reverse atrophy and potential intestinal metaplasia by inhibiting the expression of p-AKT, HIFA, and VEGF.ConclusionBioactive compounds in Coptidis Rhizoma have the potential to prevent atrophy and intestinal metaplasia. These compounds function by regulating the proteins implicated in AKT /HIF-1α/VEGF signalling pathways that are crucial in gastric epithelial cell differentiation, proliferation and maturation.

Research Progress of Helicobacter pylori-Associated Extragastric Diseases

Helicobacter pylori (Hp) is a common Gram-negative bacillus causing gastrointestinal infections.It mainly exists on the surface of gastric epithelial cells and in mucus and is associated with gastric ulcers,gastric cancer,and gastric mucosa-associated lymphomas.Studies have shown that Hp can induce or exacerbate certain extragastric diseases and is associated with the occurrence of coronavirus disease 2019.It is hypothesized that Hp may be indirectly or directly involved in the occurrence and development of diseases by stimulating the production of inflammatory cytokines or inducing cross-immune reactions.In addition,Hp can enter Candida to release toxins continuously and play a role in escaping the recognition of the host immune system and the bactericidal effect of drugs.This article reviews the research progress in Hp-associated extragastric diseases in recent years,aiming to draw the attention of clinical workers to Hp-associated extragastric diseases and enrich the knowledge about Hp infection for formulating countermeasures to avoid the aggravation or triggering of other diseases by Hp.

Catha edulis Leaves: Morphological Characterization and Anti-Inflammatory Properties in an In Vitro Model of Gastritis.

Khat leaves, indigenous to eastern Africa, have been chewed for centuries for their stimulant effects, attributed to alkaloids such as cathinone and cathine. Although associated with gastric disorders like gastritis and gastro-oesophageal reflux disease, the underlying molecular mechanisms remain unclear. This study aimed to examine the morpho-anatomy of khat leaves using light microscopy and histochemistry and to assess the effects of leaf extracts and alkaloids on human gastric epithelial cells (GES-1). The study identified specific cells in the palisade-spongy transition zone as storage sites for psychoactive alkaloids. Leaf extracts were prepared by mimicking the chewing process, including a prolonged salivary phase followed by a gastric phase. Cytotoxicity and cell viability were evaluated using LDH and MTT assays, respectively. Additionally, the impact on IL-8 secretion, a key chemokine in gastric inflammation, was analysed under normal and TNF-α-stimulated conditions. The results showed no increase in cytotoxicity up to 250 µg/mL. However, there was a significant decrease in cell metabolism and a reduction in both basal and TNF-α-induced IL-8 secretion, but cathinone and cathine were inactive. These findings suggest that khat may not directly cause the gastric issues reported in the literature, which would rather be attributed to other confounding factors, highlighting the need for further research to clarify its biological impacts.

Cinnamaldehyde alleviates aspirin-induced gastric mucosal injury by regulating pi3k/akt pathway-mediated apoptosis, autophagy and ferroptosis

BackgroundGastric mucosal injury is a chronic and progressive stomach disease that can be caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, there is an urgent need to find safe and effective drugs to prevent gastric mucosal injury due to NSAIDs. Cinnamaldehyde (CA) is a bioactive compound extracted from the rhizome of cinnamon and has various pharmacological functions, including anti-inflammatory, analgesic, antiapoptotic, and antioxidant activities. However, the potential pharmacological effect of CA on gastric mucosal injury remains unknown. PurposeThe aim of this study was to investigate the protective effects of CA on aspirin-induced gastric mucosal injury and to explore its mechanism of action MethodsThe effect of CA on gastric mucosal injury was investigated in vitro and in vivo, in vitro mouse model of gastric mucosal injury induced by aspirin, in vitro model of GES-1 cell injury by aspirin and Erastin. The mechanism of action of CA was determined using Transcriptomics and bioinformatics. ResultsCA exerted its protective effects against gastric mucosal injury by modulating the downstream targets, including mTOR, GSK3β, and NRF2, via the PI3K/AKT signaling pathway to inhibit autophagy, apoptosis, and ferroptosis in the gastric epithelial cells. Further cellular experiments confirmed that the PI3K/AKT pathway was a key target for CA against gastric mucosal injury. ConclusionThis study provides the first evidence of CA, an active compound in cinnamon, possessing therapeutic potential in preventing and treating gastric mucosal injury, with its mechanism involving the regulation of apoptosis, autophagy, and ferroptosis in gastric epithelial cells mediated by the PI3K/AKT signaling pathway.

The protective effects and potential mechanisms of fulvic acid against ethanol-induced gastric mucosal injury in mice

Fulvic acid (FA) is a kind of natural organic acids extracted from lignite, which is the active ingredient in Wujin oral liquid, a proprietary Chinese medicine used to treat gastric and duodenal ulcers. However, our understanding of the mechanisms of FA remains limited. Currently, the protection of FA and its mechanism were explored using the ethanol-induced gastric mucosal injury mouse model. The histopathological examinations showed FAs at three doses effectively reduced gastric congestion, oedema caused by ethanol, and prevented gastric epithelial cell fall-off. When compared to the model group, FAs reduced IL-1β and IL-6 levels in serum, as well as IL-1β, IL-6, TNF-α, and COX-2 expression levels in tissue. Furthermore, FAs significantly inhibited p65, P38 MAPK, and Erk1/2 phosphorylation in damaged gastric tissue. It was indicated FA has good protection against ethanol-induced gastric mucosa injuries in mice and this effect was related to NF-κB and MAPK signalling pathways.

PDLIM1 Inhibits Chemoresistance by Blocking DNA Damage Repair in Gastric Cancer.

Current cisplatin (CDDP) resistance remains a major challenge in the treatment of advanced gastric cancer. To address the issue of drug resistance, we explored the regulatory functions of PDZ and LIM structural domain protein 1 (PDLIM1) in CDDP chemotherapy for gastric cancer. In this study, we analyzed PDLIM1 expression and prognosis using bioinformatics on publicly available data. PDLIM1 expression in a gastric mucosal epithelial cell line (GSE-1), CDDP- sensitive (SGC7901, BGC823) and CDDP-resistant gastric cancer cells was detected by RTqPCR and Western blotting. Cell proliferative capacity was assessed by knockdown of PDLIM1 and overexpression of PDLIM1 in cells administered in combination with cisplatin, and apoptotic levels were measured by CCK-8 and colony formation assay and by flow cytometry. Expression of breast cancer susceptibility gene 1 (BRCA1) and γH2AX was determined by Western blotting or immunofluorescence staining. Downregulation of PDLIM1 was found in tumor tissues and cells, which was associated with poor clinical outcomes. Knockdown of PDLIM1 enhanced proliferation and attenuated apoptosis in gastric cancer cells. In addition, the therapeutic effects of CDDP on proliferation, apoptosis, and DNA damage repair were attenuated by PDLIM1 deletion.PDLIM1 expression was downregulated in CDDP-resistant tumor cells. Overexpression of PDLIM1 overcomes CDDP resistance in tumor cells as BRCA1 expression decreases and γH2AX expression increases. Our findings demonstrate that PDLIM1 enables to alleviate gastric cancer progression and resistance to cisplatin via impeding DNA damage repair.

Progress of Clinical Studies Targeting Claudin18.2 for the Treatment of Gastric Cancer.

Claudin18.2 is a tight junction protein, highly selective, generally expressed only in normal gastric mucosal epithelial cells, which can effectively maintain the polarity of epithelial and endothelial cells, thus effectively regulating the permeability and conductance of the paracellular pathway. Abnormal expression of Claudin18.2 can occur in various primary malignant tumors, especially gastrointestinal tumors, and even in metastatic foci. It regulates its expression by activating the aPKC/MAPK/AP-1 pathway, and therefore, the Claudin18.2 protein is a pan-cancer target expressed in primary and metastatic lesions in human cancer types. Zolbetuximab (IMAB362), an antibody specific for Claudin18.2, has been successfully tested in a phase III clinical trial, and the results of the study showed that combining Zolbetuximab with chemotherapy notably extends patients' survival and is expected to be a potential first-line treatment for patients with Claudin18.2(+)/HER-2(-) gastric cancer. Here, we systematically describe the biological properties and oncogenic effects of Claudin18.2, centering on its clinical-pathological aspects and the progress of drug studies in gastric cancer, which can help to further explore its clinical value.

Alginate Oligosaccharides Protect Gastric Epithelial Cells against Oxidative Stress Damage through Induction of the Nrf2 Pathway.

Gastric diseases represent a significant global public health challenge, characterized by molecular dysregulation in redox homeostasis and heightened oxidative stress. Although prior preclinical studies have demonstrated the cytoprotective antioxidant effects of alginate oligosaccharides (AOSs) through the Nrf2 pathway, whether such mechanisms apply to gastric diseases remains unclear. In this study, we used the GES-1 gastric cell line exposed to hydrogen peroxide (H2O2) as a damage model to investigate the impact of AOS on cell viability and its associated mechanisms. Our results revealed that pre-incubation with AOS for either 4 h or 24 h significantly improved the viability of GES-1 cells exposed to H2O2. In addition, AOS reduced the intracellular ROS levels, activating the Nrf2 signaling pathway, with increased Nrf2 protein and mRNA expression and a significant upregulation of the target genes HO-1 and NQO1. The activation of Nrf2 was correlated with decreased Keap1 protein expression and an increased level of the autophagy protein p62/SQSTM1, suggesting the activation of Nrf2 through a noncanonical pathway. This study suggests that AOS is a potential treatment for protecting gastric epithelial cells from oxidative stress by activating the p62/SQSTM1-Keap1-Nrf2 axis and laying the foundation for future investigations about its specific therapeutic mechanisms.

Design and discovery of urease and Helicobacter pylori inhibitors based on benzofuran/benzothiophene-sulfonate and sulfamate scaffolds for the treatment of ureolytic bacterial infections

A series of sulfonate and sulfamate derivatives bearing benzofuran or benzothiophene scaffold exhibited potent inhibitory effect on urease enzyme. Most of the derivatives exhibited significantly higher potency than thiourea, the standard inhibitor. Compound 1s was identified as the most potent urease inhibitor with an IC50 value of 0.42 ± 0.08 μM, which is 53-fold more potent than thiourea, positive control (IC50 = 22.3 ± 0.031 μM). The docking results further revealed the binding interactions towards the urease active site. Phenotypic screening revealed that compounds 1c, 1d, 1e, 1f, 1j, 1n, and 1t exhibit high potency against H. pylori with MIC values ranging from 0.00625 to 0.05 mM and IC50 values ranging from 0.0031 to 0.0095 mM, much more potent than the positive control, acetohydroxamic acid (MIC and IC50 values were 12.5 and 7.38 mM, respectively). Additional studies were performed to investigate the toxicity of these compounds against the gastric epithelial cell line (AGS) and their selectivity profile against E. coli, and five Lactobacillus species representative of the gut microflora. Permeability characteristics of the most promising derivatives were investigated in Caco-2 cell line. The results indicate that the compounds could be targeted in the GIT only without systemic side effects.

Helicobacter pylori disrupts gastric mucosal homeostasis by stimulating macrophages to secrete CCL3

BackgroundHelicobacter pylori (H. pylori) is the predominant etiological agent of gastritis and disrupts the integrity of the gastric mucosal barrier through various pathogenic mechanisms. After H. pylori invades the gastric mucosa, it interacts with immune cells in the lamina propria. Macrophages are central players in the inflammatory response, and H. pylori stimulates them to secrete a variety of inflammatory factors, leading to the chronic damage of the gastric mucosa. Therefore, the study aims to explore the mechanism of gastric mucosal injury caused by inflammatory factors secreted by macrophages, which may provide a new mechanism for the development of H. pylori-related gastritis.MethodsThe expression and secretion of CCL3 from H. pylori infected macrophages were detected by RT-qPCR, Western blot and ELISA. The effect of H. pylori-infected macrophage culture medium and CCL3 on gastric epithelial cells tight junctions were analyzed by Western blot, immunofluorescence and transepithelial electrical resistance. EdU and apoptotic flow cytometry assays were used to detect cell proliferation and apoptosis levels. Dual-luciferase reporter assays and chromatin immunoprecipitation assays were used to study CCL3 transcription factors. Finally, gastric mucosal tissue inflammation and CCL3 expression were analyzed by hematoxylin and eosin staining and immunohistochemistry.ResultsAfter H. pylori infection, CCL3 expressed and secreted from macrophages were increased. H. pylori-infected macrophage culture medium and CCL3 disrupted gastric epithelial cells tight junctions, while CCL3 neutralizing antibody and receptor inhibitor of CCL3 improved the disruption of tight junctions between cells. In addition, H. pylori-infected macrophage culture medium and CCL3 recombinant proteins stimulated P38 phosphorylation, and P38 phosphorylation inhibitor improved the disruption of tight junctions between cells. Besides, it was identified that STAT1 was a transcription factor of CCL3 and H. pylori stimulated macrophage to secret CCL3 through the JAK1-STAT1 pathway. Finally, after mice were injected with murine CCL3 recombinant protein, the gastric mucosal injury and inflammation were aggravated, and the phosphorylation level of P38 was increased.ConclusionsIn summary, our findings demonstrate that H. pylori infection stimulates macrophages to secrete CCL3 via the JAK1-STAT1 pathway. Subsequently, CCL3 damages gastric epithelial tight junctions through the phosphorylation of P38. This may be a novel mechanism of gastric mucosal injury in H. pylori-associated gastritis.