The Helicobacter pylori (H. pylori) virulence factor CagA undergoes tyrosine phosphorylation upon entry into host cells, enabling it to engage with multiple SH2 domain-containing proteins and disrupt host signaling pathways to promote carcinogenesis. Among these interacting partners, the tyrosine phosphatase SHP1 plays a unique role as a negative regulator by directly dephosphorylating the phosphorylated EPIYA (EPIpYA) motif of CagA, thereby counteracting its oncogenic effects. However, the molecular basis underlying SHP1's ability to specifically recognize and efficiently dephosphorylate CagA remains poorly understood. In this study, we demonstrated that the β4-β5 loop within the PTP domain of SHP1 is important for its enhanced catalytic efficiency toward the EPIpYA-peptide, as revealed by enzyme kinetics assays and molecular dynamics simulations. Substitution of this loop with the corresponding sequence from SHP1's homologue SHP2 markedly impaired SHP1's ability to dephosphorylate CagA and suppressed its tumor-suppressive function. Furthermore, we showed that the C-SH2 domain of SHP1 contributes to its efficient activation by phosphorylated CagA, and replacement of this domain compromised SHP1's ability to suppress H. pylori-induced malignant phenotypes. Together, these findings identify the β4-β5 loop as a key structural feature that enables SHP1 to efficiently dephosphorylate CagA, and the C-SH2 domain as a critical regulator that enhances SHP1 activation, both of which collectively contribute to counteracting H. pylori-induced carcinogenesis. This study provides a structural basis for understanding the unique tumor-suppressive mechanism of SHP1 and offers potential targets for developing SHP1-specific agonists against H. pylori-associated gastric cancer.

Purpose: Inflammatory bowel disease (IBD) is a chronic inflammatory disorder strongly associated with intestinal microbial dysregulation. Although 5-aminosalicylic acid (5-ASA) is widely used in the clinical management of IBD, its therapeutic efficacy is often limited. To address this, the present study aimed to develop a bifidobacterium-derived extracellular vesicle-based drug delivery system (B-MVs@5-ASA) to enhance the therapeutic outcomes of IBD. Methods: B-MVs were isolated by PEG precipitation and loaded with 5-ASA via sonication to obtain B-MVs@5-ASA. Their morphology, particle size, zeta potential, and encapsulation efficiency were analyzed using TEM, DLS, and UV spectrophotometry. Cellular uptake, cytotoxicity (LDH and NO assays), and anti-inflammatory effects were assessed in RAW 264.7 and Caco-2 cells. A DSS-induced colitis mouse model was established to evaluate therapeutic efficacy. Cytokines (ELISA), colon histopathology (H&E), tight-junction proteins (IF), and gut microbiota composition (16S rRNA sequencing) were systematically analyzed. Results: B-MVs@5-ASA exhibited a particle size of 104.3 ± 2.81 nm and an encapsulation efficiency of 11.14% ± 3.63%. B-MVs@5-ASA exhibited the strongest anti-inflammatory effect in vitro and most effectively alleviated DSS-induced colitis in vivo, outperforming monotherapies in reducing inflammation, tissue damage, and enhancing barrier integrity. B-MVs@5-ASA further promoted goblet cell regeneration and beneficially modulated the gut microbiota by enriching Akkermansia and suppressing Escherichia, thereby restoring microbial homeostasis. Conclusions: B-MVs@5-ASA provides potent anti-inflammatory and mucosal-protective effects by modulating cytokine balance, enhancing epithelial barrier function, and reshaping gut microbiota. These findings highlight probiotic vesicle-based nanoplatforms as a safe and promising strategy for targeted IBD therapy.

CagA, one of the key virulence factors of Helicobacter pylori, plays a significant role in H. pylori-associated gastric cancer by actively participating in neoplastic transformation. Among CagA variants, East Asian type CagA (CagAE) bearing the EPIYA-D motif exhibits a higher risk than the Western-type (CagAW) with EPIYA-C motifs. In this study, we investigated the interactions of CagAE and CagAW and host intracellular Grb2 and found a pronouncedly greater recruitment of Grb2 by CagAE compared to CagAW. Our findings revealed the phosphorylated tyrosine in the EPIYA motif is very important for the binding of CagA to Grb2. Phe at Y + 5 position in EPIYA-D, which interacts with Trp121 in SH2 domain of Grb2, established the higher affinity than the interaction of EPIYA-C and Grb2-SH2. The substitute of Phe to Asp/Ala in CagAE EPIYA-D reduced the recruitment of Grb2 by CagAE, and neutralized the stronger induced malignant characteristics of the recipient cells. These findings provide additional insights into the distinct regulatory mechanisms employed by CagAE and CagAW, contributing to a better understanding of the higher oncogenic risk associated with H. pylori CagAE.

Probiotic-based therapies have great potential to treat inflammatory bowel disease (IBD). Still, their success is limited by difficulties in ensuring survival, colonization, and targeted effects within the harsh environment of the gastrointestinal tract. This study presents a bio-coated probiotic strategy for treating colitis in mice, using self-crosslinking mussel adhesive protein (Map) to form a protective layer around Bifidobacterium longum (BL). Because Map contains abundant lysine residues that confer positive charges, it interacts electrostatically with negatively charged alginate (Alg) to form the BL@Map@Alg formulation. Compared to uncoated BL, BL@Map@Alg increased survival under oxygen exposure by 19.6-fold, showed a 76.8-fold increase in resistance to simulated stomach acid, and exhibited a 6.2-fold boost in intestinal colonization. It also demonstrated superior ROS scavenging ability, decreasing ROS levels by 41.1 %. In a mouse colitis model, BL@Map@Alg reduced weight loss, colon shortening, and inflammatory cytokines compared to untreated colitis. It also helped restored intestinal barrier function by increasing the levels of tight junction proteins ZO-1 and claudin-1, which were diminished in DSS-treated mice. 16S rRNA sequencing showed that BL@Map@Alg lowered Escherichia abundance from 27.5 % to 0.042 % while increasing Akkermansia from 0.73 % to 9.3 %. These results highlight the potential for BL@Map@Alg to enhance probiotic therapy by improving survival, colonization, and gut microbiota, offering a promising strategy for personalized and precision medicine.

Nanoplastics, in combination with pathogenic microorganisms or toxic substances, have been shown to induce oxidative stress and disrupt energy and lipid metabolism, posing significant health risks. This study evaluated the toxic effects of co-exposure to nanoplastics and Helicobacter pylori on the digestive system of mice. Transmission electron microscopy confirmed the accumulation of AuPS-NPs (Au-core polystyrene nanoplastics) in the stomach, colon, and liver, while hematoxylin and eosin staining revealed dose-dependent pathological damage in these tissues. Enzyme-linked immunosorbent assays quantified interleukin-6 (IL-6), malondialdehyde (MDA), triglyceride (TG), and lactate dehydrogenase (LDH) levels, which significantly increased in co-exposure groups compared to single-exposure groups (P < 0.05). After 28 days, the 100 mg/L H. pylori-AuPS-NPs group showed the highest levels of IL-6 (172.91 ± 1.51 pg/mL in the stomach, 188.31 ± 1.49 pg/mL in the colon, and 174.85 ± 0.26 pg/mL in the liver) and MDA (13.49 ± 0.16 nmol/mg in the stomach, 14.39 ± 0.20 nmol/mg in the colon, and 15.61 ± 0.63 nmol/mg in the liver). These increases, accompanied by elevated TG and LDH levels, suggest aggravated inflammation, oxidative stress, and metabolic disruption. Accumulation analysis showed that while AuPS-NPs content significantly increased over time and with higher concentrations, co-exposure with H. pylori reduced nanoparticle accumulation in gastric and intestinal tissues. These results indicate that co-exposure exacerbates tissue damage, inflammation, oxidative stress, and metabolic disruptions while modulating nanoparticle accumulation. These findings highlight the synergistic toxic effects of nanoplastics and H. pylori, underscoring the importance of understanding combined exposure risks for public health.

Purpose:Nanoplastics (NPs) are widespread environmental pollutants that pose risks to human health; however, risk thresholds for NPs accumulation in human tissues remain poorly defined. This study validates gold-core polystyrene nanoplastics (AuPS-NPs) as a quantifiable proxy for polystyrene nanoplastics (PS-NPs) to evaluate toxicity and bioaccumulation at environmentally relevant concentrations, with extrapolation to human health implications. Methods:AuPS-NPs were synthesized with a gold core and polystyrene shell, characterized by transmission electron microscopy (TEM) and quantified by inductively coupled plasma mass spectrometry (ICP-MS). In vitro, human gastric adenocarcinoma (AGS) and human colorectal adenocarcinoma (Caco-2) cells were exposed to AuPS-NPs or PS-NPs to assess cytotoxicity, reactive oxygen species generation, and mitochondrial membrane depolarization. In vivo, BALB/c mice were orally exposed to AuPS-NPs (1 and 10 mg/L) for 98 days, followed by evaluation of intestinal accumulation, body weight, organ indices, and biomarkers of inflammation, lipid metabolism, energy metabolism, and oxidative stress. A toxicokinetic-toxicodynamic (TK-TD) model was developed to simulate NPs accumulation, dose-response relationships, and human risk thresholds. Results:AuPS-NPs and PS-NPs showed comparable concentration-dependent cytotoxicity in vitro. In vivo, chronic AuPS-NP exposure caused intestinal accumulation, body weight reduction, increased organ indices, and biomarker perturbations including interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), triglycerides (TG), total cholesterol (T-CHO), adenosine triphosphate (ATP), lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD). TK-TD modeling yielded a human intestinal toxicity threshold of 9.529 × 105 particles/kg, providing a particle-based reference for risk extrapolation. Conclusion:AuPS-NPs replicate PS-NPs toxicity and enable quantitative risk assessment. Chronic exposure may induce intestinal accumulation and systemic toxicity, underscoring the need for regulatory thresholds to mitigate nanoplastic risks.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease caused by severe fever with thrombocytopenia syndrome virus (SFTSV) which results in a high mortality rate and poses a public health threat. Gene variation of SFTSV is one of the major forces driving its persistence and widespread prevalence. However, how genetic variations affect virus invasion is not yet fully understood. In this study, we evaluated the adaptive advantage of three stable high-frequency substitutions D170N, I323V, and K619R located on the envelope glycoprotein of SFTSV based on 1041 M segments of their genomes. The result demonstrated that single mutation of D170N, or K619R reduced infectivity of mutant. However, the combined presence of both D170N, and K619R mutation enhanced infectivity of mutants. Structure model and SPR assay studies indicated that the substitution at the 170 site reduced the binding affinity between Gn glycoprotein and host C-C motif chemokine receptor 2 (CCR2). Additionally, neutralization assay showed I323/K619R mutant exhibited completely resistance to neutralizing antibodies pressure. This study reveals that SFTSV balances its entry ability by gene variation of different loci on its glycoprotein via a trade-off between Gn and Gc. In addition, a weakened invasion strategy facilitated by site mutations benefits its immune evasion. The findings provide mechanistic insights into its prevalence, thereby enabling early warnings for potential future outbreaks.

Chronic Helicobacter pylori infection is a major contributor to gastric disease progression, with its involvement in autophagy and stem cell dynamics playing a critical role in disease mechanisms. This study investigated how H. pylori, particularly in combination with the carcinogen N-nitroso-N-methylurea (NMU), disrupted autophagy and stem cell function, driving gastric pathology. H. pylori infection significantly increased autophagy, promoted the epithelial-mesenchymal transition, suppressed Tff2 and Ghrelin expression in mouse gastric organoids, and enhanced stem cell proliferation (organoid numbers increased 92% compared to control at 24 weeks, p < 0.001), while NMU caused milder autophagy, severe inflammation, glandular dilation, and reduced stemness markers (CD133 decreased 30% at 24 weeks, p < 0.05). Combined H. pylori and NMU exposure synergistically dysregulated Tff2/Ghrelin expression, exacerbated autophagic flux disruption, and impaired stem cell function, reducing organoid budding (decreased 43% vs. H. pylori alone at 36 weeks, p < 0.01) and dysregulating CD133, CD44, Lgr5, and SOX2 expression. Pathologically, this combination led to severe gastric damage, including intestinal metaplasia and neutrophil infiltration. Chloroquine (CQ) treatment mitigates these effects by reversing autophagic dysfunction, restoring stem cell capacity (Lgr5 increased 97% at 44 weeks, p < 0.05), differentially modulating Tff2/Ghrelin: potentiating Tff2 and suppressing Ghrelin, normalizing organoid growth, attenuating the EMT, and reducing inflammation, particularly in the H. pylori + NMU group. These findings elucidate how H. pylori and NMU drive gastric pathology through autophagy-stem cell crosstalk and highlight CQ's potential as a targeted therapeutic strategy for infection-associated gastric damage.

Nanoplastics (NPs) are emerging environmental contaminants whose surface charge governs their biological interactions. This study investigated how differentially charged NPs modulate Helicobacter pylori virulence and gastric pathogenesis. A chronic infection mouse model was used to evaluate co-exposure to H. pylori and positive (PS-NH2), negative (PS-COOH), or neutral (PS) NPs. Gastric NPs accumulation and tissue injury were assessed by TEM and H&E staining. Oxidative stress markers, including reactive oxygen species (ROS) and malondialdehyde (MDA), antioxidants such as superoxide dismutase (SOD) and glutathione (GSH), and cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), the chemokine monocyte chemoattractant protein-1 (MCP-1), and the neutrophil enzyme myeloperoxidase (MPO), were quantified. The expression of virulence and adhesion genes, including cytotoxin-associated gene A (cagA), vacuolating cytotoxin A gene (vacA), blood group antigen-binding adhesin A gene (babA), and outer inflammatory protein A gene (oipA), was analyzed. Bacterial motility and biofilm formation were also evaluated. All NPs accumulated in gastric tissue and exacerbated injury, with severity following PS-NH2 > PS-COOH > PS. Co-exposure elevated oxidative stress and inflammation while reducing antioxidant capacity. Virulence and adhesion genes were upregulated across NPs groups, with PS-NH2 inducing early activation and PS-COOH causing sustained increases. PS-NH2 NPs showed no significant effect on early bacterial motility but suppressed late-stage swimming. Biofilm formation was markedly increased, particularly with PS-NH2 exposure. NPs exacerbate H. pylori-induced gastric injury in a surface charge-dependent manner by promoting bacterial virulence, oxidative stress, and inflammation. These findings provide new insights into host-pathogen interactions relevant to gastric disease.

To explore the intergenerational cardiotoxicity of nanoplastics, maternal mice were exposed to 60 nm polystyrene nanoplastics (PS-NP) during pregnancy and lactation. The results showed that PS-NP can enter the hearts of offspring and induce myocardial fiber arrangement disorder, acidophilic degeneration of cardiomyocytes, and elevated creatine kinase isoenzymes (CK-MB) and lactate dehydrogenase (LDH) levels after maternal exposure to PS-NP at 100 mg/kg during pregnancy and lactation. Mechanistically, KEGG analysis of RNA sequencing showed the participation of hypoxia-inducible factor-1 (HIF-1) and ferroptosis in PS-NP-induced cardiotoxicity. Key features of ferroptosis, including Fe2+ accumulation, mitochondrial injury, oxidative stress, GPX4 downregulation, and FTH1, ACSL4, and SLC7A11 upregulation, were detected. Furthermore, PS-NP treatment upregulated the expressions of HIF-1α and HO-1, and PS-NP-induced ferroptosis can be alleviated by inhibition of HIF-1α using si-HIF-1α. This study provided an insightful reference for the intergenerational cardiotoxicity assessment of PS-NP.

Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg center dot L-1) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin-eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1 beta, IL-6, and TNF-alpha) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg center dot L-1) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg center dot L-1 PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg center dot L-1 PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8(+) T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-alpha and IL-1 beta were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.

Background: SHP1 has been documented as a tumor suppressor and it was thought to play an antagonistic role in the pathogenesis of Helicobacter pylori infection. In this study, the exact mechanism of this antagonistic action was studied. Materials and methods: AGS, MGC803, and GES-1 cells were infected with H. pylori, intracellular distribution changes of SHP1 were first detected by immunofluorescence. SHP1 overexpression and knockdown were then constructed in these cells to investigate its antagonistic roles in H. pylori infection. Migration and invasion of infected cells were detected by transwell assay, secretion of IL-8 was examined via ELISA, the cells with hummingbird-like alteration were determined by microexamination, and activation of JAK2/STAT3, PI3K/Akt, and ERK pathways were detected by immunoblotting. Mice infection model was established and gastric pathological changes were evaluated. Finally, the SHP1 activator sorafenib was used to analyze the attenuating effect of SHP1 activation on H. pylori pathogenesis in vitro and in vivo. Results: The sub-localization of SHP1 changed after H. pylori infection, specifically that the majority of the cytoplasmic SHP1 was transferred to the cell membrane. SHP1 inhibited H. pylori-induced activation of JAK2/STAT3 pathway, PI3K/Akt pathway, nuclear translocation of NF-kappa B, and then reduced EMT, migration, invasion, and IL-8 secretion. In addition, SHP1 inhibited the formation of CagA-SHP2 complex by dephosphorylating phosphorylated CagA, reduced ERK phosphorylation and the formation of CagA-dependent hummingbird-like cells. In the mice infection model, gastric pathological changes were observed and increased IL-8 secretion, indicators of cell proliferation and EMT progression were also detected. By activating SHP1 with sorafenib, a significant curative effect against H. pylori infection was obtained in vitro and in vivo. Conclusions: SHP1 plays an antagonistic role in H. pylori pathogenesis by inhibiting JAK2/STAT3 and PI3K/Akt pathways, NF-kappa B nuclear translocation, and CagA phosphorylation, thereby reducing cell EMT, migration, invasion, IL-8 secretion, and hummingbird-like changes.

CagA is a significant oncogenic factor injected into host cells by Helicobacter pylori, which is divided into two subtypes: East Asian type (CagAE), characterized by the EPIYA-D motif, and western type (CagAW), harboring the EPIYA-C motif. CagAE has been reported to have higher carcinogenicity than CagAW, although the underlying reason is not fully understood. SHIP2 is an intracellular phosphatase that can be recruited by CagA to perturb the homeostasis of intracellular signaling pathways. In this study, we found that SHIP2 contributes to the higher oncogenicity of CagAE. Co-Immunoprecipitation and Pull-down assays showed that CagAE bind more SHIP2 than CagAW. Immunofluorescence staining showed that a higher amount of SHIP2 recruited by CagAE to the plasma membrane catalyzes the conversion of PI(3,4,5)P3 into PI(3,4)P2. This alteration causes higher activation of Akt signaling, which results in enhanced IL-8 secretion, migration, and invasion of the infected cells. SPR analysis showed that this stronger interaction between CagAE and SHIP2 stems from the higher affinity between the EPIYA-D motif of CagAE and the SH2 domain of SHIP2. Structural analysis revealed the crucial role of the Phe residue at the Y + 5 position in EPIYA-D. After mutating Phe of CagAE into Asp (the corresponding residue in the EPIYA-C motif) or Ala, the activation of downstream Akt signaling was reduced and the malignant transformation of infected cells was alleviated. These findings revealed that CagAE hijacks SHIP2 through its EPIYA-D motif to enhance its carcinogenicity, which provides a better understanding of the higher oncogenic risk of H. pylori CagAE.

ABSTRACT Background 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. Materials and Methods 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. Results 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. Conclusion 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.

Chronic infection by Helicobacter pylori strains expressing cytotoxin-associated gene A (CagA) are the strongest risk factor for gastric cancer. CagA can be classified into East Asian-type and Western-type (CagAE and CagAW), with CagAE being more closely associated with gastric cancer. This study aimed to investigate the impact of CagAE on intracellular signaling pathways to explain its high oncogenicity. Mutant H. pylori strains expressing either CagAE or CagAW were generated by transforming CagAE/W-expression plasmid into CagA-deleted G27 strain (G27ΔCagA). In human gastric epithelial cells (GES-1) infection, CagAE induced more severe cytopathic changes, including higher interleukin-8 (IL-8) secretion, reduced cell viability, more pronounced “hummingbird phenotype” alterations, and increased cell migration and invasion compared to CagAW. Transcriptome analysis revealed that CagAE had a stronger effect on the up-regulation of key intracellular processes, including tumor necrosis factor-ɑ (TNF-ɑ) signal pathway via nuclear factor kappa-B (NF-κB), inflammatory response, interferon-γ (IFN-γ) response, hypoxia, ultraviolet (UV) response, and Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) signaling. A significant upregulation of hypoxia-related genes was a notable feature of CagAE. GES-1 cells infected with CagAE exhibited more severe intracellular hypoxia and higher levels of reactive oxygen species (ROS) than those infected with CagAW. Inhibition of hypoxia-inducible factor-1α (HIF-1α), which blocks hypoxia signaling, mitigated CagAE-induced cell migration, emphasizing the role of hypoxia in mediating CagAE effects. The study provides transcriptome evidence of CagA-associated intracellular regulation during H. pylori infection, demonstrating that CagAE exerts stronger effects on intracellular signaling than CagAW. These findings offer insights into the heightened carcinogenic potential of CagAE in H. pylori-induced gastric cancer.

Growth factor receptor bound protein 7 (GRB7) is reportedly upregulated in human gastric cancer (GC), which is closely associated with tumor progression and prognosis. However, the mechanism underlying its dysregulation in GC remains poorly understood. In this study, we found that GRB7 overexpression was associated with Helicobacter pylori (H. pylori) infection. GC cells (AGS and MGC-803) infection assays revealed that this upregulation was mediated by the transcription factor STAT3, and activation of STAT3 by H. pylori promoted GRB7 expression in infected GC cells. Moreover, CagA, the key virulence factor of H. pylori, was found involved in STAT3-mediated GRB7 overexpression. The overexpressed GRB7 further promoted GC cell proliferation, migration, and invasion by activating ERK signaling. Mice infection was further used to investigate the action of GRB7. In H. pylori infection, GRB7 expression in mice gastric mucosa was elevated, and higher STAT3 and ERK activation were also detected. These results revealed GRB7-mediated pathogenesis in H. pylori infection, in which H. pylori activates STAT3, leading to increased GRB7 expression, then promotes activation of the ERK signal, and finally enhances malignant properties of infected cells. Our findings elucidate the role of GRB7 in H. pylori-induced gastric disorders, offering new prospects for the treatment and prevention of H. pylori-associated gastric carcinogenesis by targeting GRB7.

YAP participates in autophagy associated with many diseases. In this study, we demonstrate that YAP promotes autophagy by interacting with beclin 1, upregulating beclin 1 and LC3B-II protein expression, and promoting autophagosome formation after H. pylori infection in a vacuolating cytotoxin A-dependent manner. The protein levels of β-catenin in the cytoplasm and nuclei of GES-1 cells and the mRNA levels of Axin2, Myc, Lgr5, and Ccnd1 were increased in H. pylori-infected cells or YAP-overexpressed cells, but were decreased in YAP-silenced cells. The β-catenin inhibitor XAV939 significantly downregulated autophagy, whereas the activator LiCl showed opposite effects. An H. pylori-infected mouse model of gastric carcinoma was successfully established. The mouse model showed that H. pylori infection, when combined with NMU, promoted the tumorigenesis of gastric tissues; increased IL-1β, IL-6, and TNF-α levels; promoted NO release; and increased the expression of beclin 1, LC3B-II more than NMU alone. Chloroquine inhibited these phenomena, but did not completely attenuate the effects of H. pylori. These results demonstrate that chloroquine can be used as a drug for the treatment of H. pylori-related gastric cancer, but the treatment should simultaneously remove H. pylori.

目的 在幽门螺杆菌(Helicobacter pylori,Hp)体内构建外源基因以及自身基因的过表达系统.方法 以绿色荧光蛋白基因gfp为报告基因,通过同源重组基因敲入和穿梭质粒两种方法构建Hp中基因过表达体系.同源重组法:以预先构建的基因敲除载体pSJHK的衍生质粒pSJHK4为载体,构建gfp基因敲入质粒pSJHK4-gfp,使用Hp鞭毛高表达基因flaA的启动子调控gfp的表达;以hp0547基因区域为插入位点,通过自然转化的方式将质粒转入细菌,胞内通过同源重组将gfp插入到Hp基因组中,荧光显微镜观察gfp 表达的荧光情况.穿梭质粒法:将含有鞭毛基因flaA启动子和gfp基因的表达盒连入H.pylori-E.coli穿梭质粒pCHFHP中,构建表达质粒pCHFHP-gfp,自然转化到Hp中,荧光显微镜观察gfp表达的荧光情况.用同样方法构建Hp CagA蛋白(融合有His-tag)的表达质粒pCHFHP-CagA,转入预先构建的Hp CagA敲除株,通过亲和层析纯化重组蛋白,Western blot检测CagA的表达情况.结果 构建了 gfp基因敲入质粒pSJHK4-gfp,转入Hp后细菌发出绿色荧光;基于穿梭质粒构建了 gfp基因表达质粒pCHFHP-gfp,转入Hp中细菌同样发出荧光;进一步构建了 CagA的表达质粒并转入Hp CagA敲除株中,Western blot检测到CagA蛋白,并体外纯化获得一定量蛋白.结论 基于同源重组基因敲入和穿梭质粒的方法可在Hp中构建外源基因及Hp自体基因的过表达体系,该方法能够为Hp的基因功能研究和致病因子的发掘提供基因操作工具.

目的 研究不同类型信号肽对新布尼亚病毒(SFTSV)包膜蛋白Gn表达的影响.方法 以SFTSV(SD4毒株)M段为模板PCR扩增Gn基因,双酶切后分别连接至A16H和pHL表达载体,连接产物转染293T细胞,收集细胞和上清进行Western blot、免疫荧光以及质谱检测,分析Gn重组蛋白的表达情况;ELISA检测Gn重组蛋白的结合活性.结果 成功构建缺失载体信号肽的pA16H-Gn质粒和包含信号肽的sp-pA16H-Gn质粒,以及携带另一种载体信号肽的pHL-Fc-Gn质粒.缺失载体信号肽的pA16H-Gn质粒在细胞内外均不表达Gn重组蛋白(rGn-Fc),包含A16H载体信号肽的sp-pA16H-Gn质粒在细胞内表达Gn重组蛋白(rGn-Fc),但不能分泌表达,包含pHL载体信号肽的pHL-Fc-Gn质粒可将Gn重组蛋白(rGn-Fc)分泌表达到胞外,且具有结合活性.结论 载体本身携带的信号肽会影响SFTSV Gn重组蛋白的表达,不同信号肽影响重组蛋白的表达定位.该研究为SFTSV Gn重组蛋白的开发奠定了基础,同时也为SFTSV重组疫苗的研究提供了新思路.

Reactive oxygen species (ROS) can regulate the occurrence of autophagy, and effective control of the balance between ROS and autophagy may be an important strategy for Helicobacter pylori induced gastric-related diseases. In this study, infection with H. pylori led to a lower level of ILK phosphorylation and increased ROS generation. Knockdown of ILK enhanced total ROS generation, and upregulated NADPH oxidase (NOX) subunit p22-phox levels. Inhibition of NOXs affected total ROS generation. The inhibition of NOX and ROS generation reduced Nrf2 and HO-1 levels, and knockdown of ILK significantly enhanced Nrf2 levels in H. pylori-infected GES-1 cells. Activation of Nrf2 by DMF decreased ROS levels. Therefore, NOX-dependent ROS production regulated by ILK was essential for activation of Nrf2/HO-1 signaling pathways in H. pylori-infected GES-1 cells. Beclin1, ATG5 and LC3B-II levels were higher both in H. pylori-infected and ILK-knockdown GES-1 cells. In NAC-pretreated GES-1 cells infected with H. pylori, the LC3B-II level was decreased compared to that in cells after H. pylori infection alone. Stable low expression of ILK with further knockdown of Beclin1 or ATG5 significantly reduced LC3B-II levels in GES-1 cells, while with the addition of the autophagy inhibitor chloroquine (CQ), LC3B-II and p62 protein levels were both remarkably upregulated. H. pylori accelerated the accumulation of ROS and further led to the induction of ROS-mediated autophagy by inhibiting ILK levels. Together, these results indicate that H. pylori infection manipulates the NOX-ROS-Nrf2/HO-1-ROS loop to control intracellular oxygen stress and further induced ROS-mediated autophagy by inhibiting ILK levels.