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.

OSCA/TMEM63 protein families are recognized as typical mechanosensitive (MS) ion channels in both plants and animals. Resolved OSCA and TMEM63 structures have revealed that these channels are forming dimer and monomer, respectively. Despite the distinguished architectures, OSCA and TMEM63 serve similar functions in multiple physiological processes. Recently, human TMEM63A (hTMEM63A) structure was identified, allowing for investigation into the activation mechanism of hTMEM63A through molecular dynamics (MD) simulations. In this study, we performed multi-scale MD simulations toward hTMEM63A, aiming to reveal how lipid binding regulates hTMEM63A activation. Our results identified two regions on the surface of hTMEM63A, exhibiting a preference for lysophosphatidylcholine (LPC) lipids. Further conformation analyses clarified the activation mechanism of hTMEM63A induced by LPC insertion. These simulation results provide detailed insights into the hTMEM63A-lipid interaction and significant conformational changes associated with hTMEM63A gating, thereby shed lights on the MS ion channel activation mechanism driven by lipid plugging.

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.

IntroductionHelicobacter pylori (H. pylori) infection induced miRNA dysregulation plays an important role in gastric cancer (GC) and exosomes mediate the spread of pathogenic effects.MethodsExpression of miR-362-5p and its clinical significance in GC were analyzed using data from TCGA. The effects of miR-362-5p on GC cells’ proliferation and migration were examined by using CCK-8, EdU, transwell and scratch assays. MKN45 xenograft model in nude mice was employed to evaluate impacts of miR-362-5p on GC progression in vivo. Target gene of miR-362-5p was screened by bioinformatic analysis and verified by using dual-luciferase assay. Exosomes from H. pylori-infected GES-1 cell (Hp-GES-EVs) were isolated and miR-362-5p inside the exosome was detected. The uptake of exosome by GC cells was observed through fluorescence imaging and exosome-mediated pathogenesis was explored. Furthermore, the transport of exosome-mediated miR-362-5p via blood was examined. The effect of exosome-carried miR-362-5p on hepatocellular carcinoma (HCC) progression was investigated by hepatocyte’s uptake, proliferation and migration assays.ResultsmiR-362-5p was significantly upregulated in GC tissues associated with H. pylori infection. Downregulation of miR-362-5p in GC cells inhibited proliferation and migration in vitro and suppressed tumor growth in vivo, counteracting H. pylori-induced carcinogenesis. TLE4 was confirmed as a direct target of miR-362-5p, and miR-362-5p/TLE4 axis implicated in H. pylori-driven neoplastic transformations in GC cells. Hp-GES-EVs mediated the transport of miR-362-5p, was absorbed by GC cells and detected at elevated levels in the serum of infected mice. Moreover, Hp-GES-EVs were diffused to liver and taken up by liver cells, enhancing HCC cell proliferation and migration by targeting TLE4.ConclusionH. pylori infection upregulates miR-362-5p, facilitating GC progression via TLE4 targeting. Exosome-mediated transfer amplifies its effects, contributing to liver damage and potentially facilitating HCC.

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.

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.

Helicobacter pylori infection has been thought to be associated with liver diseases, although the exact mechanisms remain elusive. This study identified H. pylori-induced liver inflammation and tissue damage in infected mice and examined the exosome-mediated mechanism underlying H. pylori infection's impact on liver injury. Exosomes were isolated from H. pylori-infected gastric epithelial GES-1 cells (Hp-GES-EVs), and the crucial virulence factor CagA was identified within these exosomes. Fluorescent labeling demonstrated that Hp-GES-EVs can be absorbed by liver cells. Treatment with Hp-GES-EVs enhanced the proliferation, migration, and invasion of Hep G2 and Hep 3B cells. Additionally, exposure to Hp-GES-EVs activated NF-κB and PI3K/AKT signaling pathways, which provides a reasonable explanation for the liver inflammation and neoplastic traits. Using a mouse model established via tail vein injection of Hp-GES-EVs, exosome-driven liver injury was evidenced by slight hepatocellular erosion around the central hepatic vein and elevated serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and IL-6. Administering the exosome inhibitor GW4869 via intraperitoneal injection in mice resulted in a reduction of liver damage caused by H. pylori infection. These findings illuminate the exosome-mediated pathogenesis of H. pylori-induced liver injury and offer valuable insights into the extra-gastrointestinal manifestations of H. pylori infection.

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.

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.

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 设计与细菌抗原检测相关的虚拟仿真综合实验,评估其在临床医学专业本科教学中的应用效果.方法 以细菌抗原与抗体特异免疫反应为核心内容,把细菌分离培养、细菌O抗原和H抗原制备、玻片凝集与肥达试验融合为一个虚拟仿真综合实验.对照组采用传统实验教学模式,实验组采用传统实验操作与虚拟仿真综合实验相结合的教学模式,通过问卷调查和病原知识小测试比较两组教学效果.结果 两组各项指标比较存在差异,实验组高于对照组(P<0.05).结论 虚拟仿真综合实验有利于学生系统掌握病原生物学、免疫学相关知识,加深对细菌生物学特性的理解,增强解决临床问题的能力.

A novel Gram-negative, motile, aerobic, spiral-shaped bacterium designated D5T, was isolated from a coastal sediment collected in the Yellow Sea. Optimal growth occurred at 30 °C, pH 7.0–8.0 and in the presence of 1–3% (w/v) NaCl. Strain D5T contained ubiquinone 8 (Q-8) as the predominant respiratory quinone. The major fatty acids (> 10%) were C16:0, C16:1 ω7c/C16:1 ω6c and C18:1w7c/C18:1w6c. The main polar lipids were phosphatidylglycerol and phosphatidylethanolamine. The draft genome is 5.6 Mb in length, and DNA G + C content is 47.2 mol%. 16S rRNA gene sequences showed that strain D5T is most closely related to Oceanospirillum beijerinckii NBRC 15445T (97.8%, sequence similarity). However, the digital DNA-DNA hybridization (dDDH) value and average nucleotide identity (ANI) between strain D5T and O. beijerinckii is only 27.8% and 77.1%. Phylogenetic trees based on 16S rRNA gene sequences and whole genomes all indicated that strain D5T formed a separate branch in the genus Oceanospirillum. Combined results of the polyphasic analyses suggested that strain D5T represents a novel species in the genus Oceanospirillum, for which the name Oceanospirillum sediminis sp. nov. is proposed. The type strain is D5T (= MCCC 1K06061T = KCTC 62987T).

The ability of Helicobacter pylori to manipulate host autophagy is an important pathogenic mechanism. We found an inverse correlation between the expression of ILK and the autophagy marker protein LC3B in H. pylori-positive human samples, H. pylori-infected mice models and H. pylori-infected GES-1 cell lines. When the ILK-knockdown GES-1 cells were infected by H. pylori, CagA were significantly degraded, autophagosomes accumulation and autolysosomes formation were significantly increased, and LC3B protein levels and ratio of LC3BII to LC3BI were also remarkably upregulated. And chloroquine treatment increased LC3B levels in ILK-knockdown GES-1 cells. The expression levels of both Rac1 and RhoA were downregulated in GES-1 cells after H. pylori infection and were decreased in ILK-knockdown GES-1 cells. The mRNA and protein levels of PAK1, MLC, and LIMK were significantly decreased and cofilin mRNA and protein levels were significantly increased in GES-1 cells treated with the Rac1 inhibitor NSC 23766. The mRNA and protein levels of ROCK1, ROCK2, MLC, and LIMK1 were significantly reduced and cofilin mRNA and protein levels were significantly increased in GES-1 cells treated with the RhoA inhibitor CCG-1423. F-actin was significantly reduced in Rac1- or RhoA-inhibited GES-1 cells. F-actin depolymerization induced autophagosomes accumulation, autolysosomes formation, and the increase of LC3B levels in GES-1 cells. Therefore, these findings revealed that ILK could serve as a novel regulator to affect Rac1/ PAK1 and RhoA/ROCKs signaling pathways, thereby influencing H. pylori-induced autophagy.

With the widespread use of plastics and nanotechnology products, nanoplastics (NPs) have become a potential threat to human health. It is of great practical significance to study and evaluate the distribution of NPs in mice as mammal models and their entry, transport, and cytotoxicity in human cell lines. In this study, we detected the tissue distribution of fluorescent polystyrene nanoplastics (PS-NPs) in mice and assessed their endocytosis, transport pathways, and cytotoxic effects in GES-1 cells. We found that PS-NPs were clearly visible in gastric, intestine, and liver tissues of mice and in GES-1 cells treated with PS-NPs. Entry of PS-NPs into GES-1 cells decreased with the inhibition of caveolae-mediated endocytosis (nystatin), clathrin-mediated endocytosis (chlorpromazine HCl), micropinocytosis (ethyl-isopropyl amiloride), RhoA (CCG-1423), and F-actin polymerization (lantrunculin A). Rac1 inhibitors (NSC 23766) had no significant effect on PS-NPs entering GES-1 cells. F-actin levels significantly decreased in CCG-1423-pretreated GES-1 cells exposed to PS-NPs. GES-1 cell ultrastructural features indicated that internalized PS-NPs can be encapsulated in vesicles, autophagosomes, lysosomes, and lysosomal residues. RhoA, F-actin, RAB7, and LAMP1 levels in PS-NPs-treated GES-1 cells were remarkably up-regulated and the Rab5 level was significantly down-regulated compared to levels in untreated cells. PS-NPs treatment decreased cell proliferation rates and increased cell apoptosis. The formation of autophagosomes and autolysosomes and levels of LC3II increased with the length of PS-NPs treatment. The results indicated that cells regulated endocytosis in response to PS-NPs through the RhoA/F-actin signaling pathway and internalized PS-NPs in the cytoplasm, autophagosomes, or lysosomes produced cytotoxicity. These results illustrate the potential threat of NPs pollution to human health.

A novel Gram-stain-negative, facultative anaerobic, motile bacterium, designated as 404T, was isolated from a marine sediment sample in the Bohai Gulf, China. Growth was observed at 10–35 °C (optimum, 20–25 °C) and in the presence of 1.0–6.0% (w/v) NaCl (optimum, 1.0–3.0%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain 404T belonged to the genus Vibrio, showing the highest sequence similarity to Vibrio renipiscarius KCTC 42287T (97.6%). The draft genome is 4.5 Mb in length, containing 4278 protein-coding genes, 60 tRNA genes and 9 rRNA genes, and DNA G+C content is 44.1 mol%. Strain 404T contains phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, and phospholipid as the main polar lipids, and the predominant quinone is ubiquinone Q-8. The major cellular fatty acids (>8.0%) are C16 : 1ω6c and/or C16 : 1ω7c, C16 : 0, C18 : 1ω6c and/or C18 : 1ω7c. Strain 404T shows some typical characteristics among the members of genus Vibrio, while it can be clearly distinguished from the closely related type strains through genome analysis (average nucleotide identity and digital DNA–DNA hybridization values), fatty acid composition and a series of physiological and biochemical characteristics. On the basis of the polyphasic analysis, strain 404T is considered to represent a novel species of the genus Vibrio, for which the name Vibrio marinisediminis sp. nov., is proposed. The type strain is 404T (= MCCC 1H00367T = KCTC 62958T).

A novel Gram-stain-negative, moderately halophilic bacterium, designated strain 204T, was isolated from a marine sediment sample in the Bohai Gulf, Yellow Sea, China. Cells of strain 204T are aerobic, motile, cocci or short rods with two lateral flagella. Growth was observed at 15–40 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, 7.0–7.5) and in the presence of 1.0–18.0% (w/v) NaCl (optimum, 3.0–8.0%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 204T belonged to the genus Halomonas, showing highest sequence similarity to Halomonas alimentaria YKJ-16T (98.08%), followed by Halomonas sediminicola (97.47%), Halomonas fontilapidosi (97.14%), Halomonas halodenitrificans (96.98%), Halomonas ventosae (96.92%), and Halomonas shengliensis (96.85%). The draft genome is 3.8 Mb in length, containing 3673 protein-coding genes, 62 tRNA genes and 10 rRNA genes, and DNA G+C content is 62.7 mol%. Strain 204T contains phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol as the main polar lipids, and the predominant respiratory quinone was ubiquinone Q-9. The major cellular fatty acids (> 5%) are C18:1ω7c, C16:1ω7c and/or C16:1ω6c, C16:0 and C12:03-OH. Strain 204T was clearly distinguished from the closely related type strains through phylogenetic analysis, dDNA-DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics comparisons. On the basis of the polyphasic analysis, strain 204T is considered to represent a novel species of the genus Halomonas, for which the name Halomonas marinisediminis sp. nov. is proposed. The type strain is 204T (= MCCC 1H00366T = KCTC 62957T).

BackgroundThe ability of Helicobacter pylori to manipulate host autophagy is an important pathogenic mechanism.ResultsWe found a negative correlation between the expression of ILK and the autophagy marker protein LC3B in H. pylori-positive human samples and in H. pylori-infected GES-1 cell lines. There was a significant accumulation of autophagosomes in ILK-knockdown GES-1 cells, and the expression levels of both LC3B and p62 were also increased. Here, we showed the activities of Rac1 and RhoA were decreased in H. pylori-infected GES-1 cells and ILK-knockdown GES-1 cells. Inhibition of Rac1 and RhoA increased LC3B levels and autophagosome formation in GES-1 cells after H. pylori infection. Simultaneously, H. pylori infection activated downstream signal molecules of Rac1 (PAK1, LIMK1 and cofilin) and RhoA (ROCK1, ROCK2 and LIMK1 and cofilin).ConclusionsOur results demonstrated that H. pylori regulated autophagy through ILK/Rac1 and ILK/RhoA signaling pathways in gastric epithelial cells.

目的 研究幽门螺杆菌(Hp)对胃上皮细胞GES-1自噬与凋亡的影响.方法 Hp与自噬抑制剂3-MA、广谱凋亡抑制剂Z-VAD-FMK处理后的GES-1细胞共培养,流式细胞术检测细胞凋亡情况,Western blot检测LC3B-Ⅱ、Caspase-3及PARP蛋白的表达.结果 3-MA处理后,与空白对照组相比,Hp组LC3B-Ⅱ蛋白相对表达量显著增高(t = 7.54,P＜0.01);3-MA+Hp组与Hp组相比,LC3B-Ⅱ蛋白相对表达量显著降低(t =-3.24,P＜0.05);与空白对照组相比,Hp组、3-MA组GES-1细胞凋亡率均显著增加(t值分别为-9.71和-3.25,P＜0.01或P＜0.05).Z-VAD-FMK处理后,与空白对照组相比,Hp组GES-1细胞凋亡率显著增加,(t =-9.29,P＜0.01);Hp+Z-VAD-FMK组较Hp组GES-1细胞凋亡率显著下降(t=-8.47,P＜0.01);与空白对照组相比,Hp组、Z-VAD-FMK组的LC3B-Ⅱ蛋白相对表达量均显著增加(t值分别为-12.98和-11.28,均P＜0.01).3-MA与Z-VAD-FMK共处理后,3-MA+Hp+Z-VAD-FMK组较3-MA+Z-VAD-FMK组和Hp+Z-VAD-FMK组的GES-1细胞凋亡率显著增加(t值分别为-4.91和-9.64,P＜0.05或P＜0.01);3-MA+Hp+Z-VAD-FMK组与3-MA+Z-VAD-FMK组相比,Caspase-3蛋白相对表达量显著增加,PARP蛋白相对表达量显著下降(t值分别为-5.16和3.02,均P＜0.05);3-MA+Hp+Z-VAD-FMK组较Hp+Z-VAD-FMK组LC3B-Ⅱ蛋白相对表达量显著下降(t=4.63,P＜0.05).结论 幽门螺杆菌既能上调GES-1细胞自噬也能诱导其凋亡,并通过增加Caspase-3表达的同时降低PARP的表达以增强自噬抑制引起的细胞凋亡.而在抑制凋亡后,幽门螺杆菌可能诱导GES-1细胞发生自噬性死亡.

C1q, as a LAIR-1 ligand, maintains monocytes quiescence and possess immunosuppressive properties. To understand the roles and molecular mechanisms, C1q mediated inflammation cytokines and several pivotal proteins in THP-1 cells after H. pylori infection were detected. The results showed that the expression of IL-8, IL-10, LAIR-1, phosphorylated/total JNK, phosphorylated/total p38-MAPK, phosphorylated/total AKT and phosphorylated/total NF-κB were up-regulated significantly in THP-1 cells after H. pylori infection. There was significant upregulation in IL-10 concentration, phosphorylated/total p38-MAPK and phosphorylated/total AKT, and downregulation in phosphorylated/total JNK in non-H. pylori infected THP-1 cells pretreated with C1q. C1q was also able to increase IL-8 and IL-10 production, and reduce LAIR-1 and phosphorylated/total p38-MAPK expression in pretreatment-C1q THP-1 cells after H. pylori infection. These results together indicated that H. pylori might induce IL-8 and IL-10 production through JNK, p38-MAPK, PI3K/AKT and NF-κB signaling pathway. C1q manipulate LAIR-1 to regulation IL-8 and IL-10 secretion in THP-1 cells after H. pylori infection through the p38-MAPK signaling pathway. This information is helpful to further understand the role and mechanisms of C1q on inflammation cytokines secretion in monocytes after H. pylori infection.