Dissecting the Helicobacter pylori-regulated transcriptome of B cells

2020 ◽  
Vol 78 (7) ◽  
Author(s):  
Bianca E Chichirau ◽  
Tamara Scheidt ◽  
Sebastian Diechler ◽  
Theresa Neuper ◽  
Jutta Horejs-Hoeck ◽  
...  

ABSTRACT Persistent infections with the bacterial group-I carcinogen Helicobacter pylori (H. pylori) have been associated with a broad range of gastric disorders, including gastritis, ulceration, gastric cancer or mucosa-associated lymphoid tissue (MALT) lymphoma. Pathogenesis of H. pylori requires a balance between immune tolerance and defense. Although H. pylori induces inflammatory responses, the immune system cannot eliminate the pathogen. The detailed molecular mechanisms of how H. pylori interferes with cells of the immune system, in particular infiltrated B cells, are not well investigated. Previously, it was shown that the bacterial effector and oncoprotein cytotoxin-associated gene A (CagA) is delivered into B cells followed by its tyrosine-phosphorylation. To investigate the functional consequences in B cells colonized by CagA-positive H. pylori, we analyzed the global transcriptome of H. pylori-infected Mec-1 cells by RNA sequencing. We found 889 differentially expressed genes (DEGs) and validated JUN, FOSL2, HSPA1B, SRC, CXCR3, TLR-4, TNF-α, CXCL8, CCL2, CCL4, MHC class I and MHC class II molecules by qPCR, western blot, flow cytometry and ELISA assays. The H. pylori-specific mRNA expression signature reveals a downregulation of inflammation- and migration-associated genes, whereas central signal transduction regulators of cell survival and death are upregulated.

2021 ◽  
Vol 10 (15) ◽  
pp. 3258
Author(s):  
Cristina Oana Mărginean ◽  
Lorena Elena Meliț ◽  
Maria Oana Săsăran

Helicobacter pylori (H. pylori) carcinogenicity depends on three major factors: bacterial virulence constituents, environmental factors and host’s genetic susceptibility. The relationship between microenvironmental factors and H. pylori virulence factors are incontestable. H. pylori infection has a major impact on both gastric and colonic microbiota. The presence of non-H. pylori bacteria within the gastric ecosystem is particularly important since they might persistently act as an antigenic stimulus or establish a partnership with H. pylori in order to augment the subsequent inflammatory responses. The gastric ecosystem, i.e., microbiota composition in children with H. pylori infection is dominated by Streptoccocus, Neisseria, Rothia and Staphylococcus. The impairment of this ecosystem enhances growth and invasion of different pathogenic bacteria, further impairing the balance between the immune system and mucosal barrier. Moreover, altered microbiota due to H. pylori infection is involved in increasing the gastric T regulatory cells response in children. Since gastric homeostasis is defined by the partnership between commensal bacteria and host’s immune system, this review is focused on how pathogen recognition through toll-like receptors (TLRs—an essential class of pathogen recognition receptors—PRRs) on the surface of macrophages and dendritic cells impact the immune response in the setting of H. pylori infection. Further studies are required for delineate precise role of bacterial community features and of immune system components.


2019 ◽  
Vol 77 (9) ◽  
Author(s):  
Narges Dastmalchi ◽  
Seyed Mahdi Banan Khojasteh ◽  
Mirsaed Miri Nargesi ◽  
Reza Safaralizadeh

ABSTRACT Helicobacter pylori infection performs a key role in gastric tumorigenesis. Long non-coding RNAs (lncRNAs) have demonstrated a great potential to be regarded as effective malignancy biomarkers for various gastrointestinal diseases including gastric cancer (GC). The present review highlights the relationship between lncRNAs and H. pylori in GC. Several studies have examined not only the involvement of lncRNAs in H. pylori-associated GC progression but also their molecular mechanisms of action. Among the pertinent studies, some have addressed the effects of H. pylori infection on modulatory networks of lncRNAs, while others have evaluated the effects of changes in the expression level of lncRNAs in H. pylori-associated gastric diseases, especially GC. The relationship between lncRNAs and H. pylori was found to be modulated by various molecular pathways.


2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Asieh Bolandi ◽  
Saam Torkan ◽  
Iman Alavi

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.


2005 ◽  
Vol 187 (22) ◽  
pp. 7703-7715 ◽  
Author(s):  
Isabel Delany ◽  
Raffaele Ieva ◽  
Alice Soragni ◽  
Markus Hilleringmann ◽  
Rino Rappuoli ◽  
...  

ABSTRACT Two important metal-responsive regulators, NikR and Fur, are involved in nickel and iron homeostasis and controlling gene expression in Helicobacter pylori. To date, they have been implicated in the regulation of sets of overlapping genes. We have attempted here dissection of the molecular mechanisms involved in transcriptional regulation of the NikR and Fur proteins, and we investigated protein-promoter interactions of the regulators with known target genes. We show that H. pylori NikR is a tetrameric protein and, through DNase I footprinting analysis, we have identified operators for NikR to which it binds with different affinities in a metal-responsive way. Mapping of the NikR binding site upstream of the urease promoter established a direct role for NikR as a positive regulator of transcription and, through scanning mutagenesis of this binding site, we have determined two subsites that are important for the binding of the protein to its target sequence. Furthermore, by alignment of the operators for NikR, we have shown that the H. pylori protein recognizes a sequence that is distinct from its well-studied orthologue in Escherichia coli. Moreover, we show that NikR and Fur can bind independently at distinct operators and also compete for overlapping operators in some coregulated gene promoters, adding another dimension to the previous suggested link between iron and nickel regulation. Finally, the importance of an interconnection between metal-responsive gene networks for homeostasis is discussed.


2020 ◽  
Author(s):  
Faisal Aziz ◽  
Mingxia Xin ◽  
Yunfeng Gao ◽  
Josh Monts ◽  
Kjersten Monson ◽  
...  

Abstract Background: Gastric cancer risk evolves over time due to environmental, dietary, and lifestyle changes including Helicobacter pylori (H. pylori) infection and consumption of hot peppers (i.e. capsaicin). H. pylori infection promotes gastric mucosal injury in the early phase of capsaicin exposure. In addition, capsaicin consumption is reported to suppress immune function and increase host susceptibility to microbial infection. This relationship suggests a need to investigate the mechanism of how both H. pylori infection and capsaicin contribute to gastric inflammation and lead to gastric cancer. No previous experimental animal models have been developed to study this dual association. Here we developed a series of mouse models that progress from chronic gastritis to gastric cancer. C57-Balb/c mice were infected with the H. pylori (SS1) strain and then fed capsaicin (0.05% or 0.2g/kg/day) or not. Consequently, we investigated the association between H. pylori infection and capsaicin consumption during the initiation of gastric inflammation and the later development of gastric cancer. Tumor size and phenotype were analyzed to determine the molecular mechanism driving the shift from gastritis to stomach cancer. Gastric carcinogenesis was also prevented in these models using the ornithine decarboxylase inhibitor DFMO (2-difluoromethylornithine). Results: This study provides evidence showing that a combination of H. pylori infection and capsaicin consumption leads to gastric carcinogenesis. The transition from chronic gastritis to gastric cancer is mediated through interleukin-6 (IL-6) stimulation with an incidence rate of 50%. However, this progression can be prevented by treating with anti-inflammatory agents. In particular, we used DFMO to prevent gastric tumorigenesis by reducing inflammation and promoting recovery of disease-free stasis. The anti-inflammatory role of DFMO highlights the injurious effect of inflammation in gastric cancer development and the need to reduce gastric inflammation for cancer prevention. Conclusions: Overall, these mouse models provide reliable systems for analyzing the molecular mechanisms and synergistic effects of H. pylori and capsaicin on human cancer etiology. Accordingly, preventive measures like reduced capsaicin consumption, H. pylori clearance, and DFMO treatment can lessen gastric cancer incidence. Lastly, anti-inflammatory agents like DFMO can play important roles in prevention of inflammation-associated gastric cancer.


2016 ◽  
Vol 73 (11) ◽  
pp. 1044-1049 ◽  
Author(s):  
Sasa Grgov ◽  
Tomislav Tasic ◽  
Biljana Radovanovic-Dinic ◽  
Daniela Benedeto-Stojanov

Background/Aim. Some studies suggest the benefit of applying different probiotic strains in combination with antibiotics in the eradication of Helicobacter pylori (H. pylori) infection. The aim of this study was to evaluate the effect of co-administration of multiple probiotic strains with triple H. pylori eradication therapy. Methods. This prospective study included 167 patients with dyspeptic symptoms and chronic gastritis who were diagnosed with H. pylori infection and randomized into two groups. The group I of 77 patients underwent triple eradication therapy, for 7 days, with lansoprazole, 2 ? 30 mg half an hour before the meal, amoxicillin 2 ? 1.000 mg per 12 hours and clarithromycin 2 ? 500 mg per 12 hours. After the 7th day of the therapy, lansoprazole continued at a dose of 30 mg for half an hour before breakfast for 4 weeks. The group II of 90 patients received the same treatment as the patients of the group I, with the addition of the probiotic cultures in the form of a capsule comprising Lactobacillus Rosell-52, Lactobacillus Rosell-11, Bifidobacterium Rosell-1755 and Saccharomyces boulardii, since the beginning of eradication for 4 weeks. Eradication of H. pylori infection control was performed 8 weeks after the therapy by rapid urease test and histopathologic evaluation of endoscopic biopsies or by stool antigen test for H. pylori. Results. Eradication of H. pylori infection was achieved in 93.3% of the patients who received probiotics with eradication therapy and in 81.8% of patients who were only on eradication therapy without probiotics. The difference in eradication success was statistically significant, (p < 0.05). The incidence of adverse effects of eradication therapy was higher in the group of patients who were not on probiotic (28.6%) than in the group that received probiotic (17.7%), but the difference was not statistically significant. Conclusion. Multiple probiotic strains addition to triple eradication therapy of H. pylori achieves a significantly better eradication success, with fewer side effects of antibiotics.


Author(s):  
Wongwarut Boonyanugomol ◽  
Kamolchanok Rukseree ◽  
Worrarat Kongkasame ◽  
Prasit Palittapongarnpim ◽  
Seung-Chul Baik ◽  
...  

CXC Chemokine Ligand 8 (CXCL8) plays an important role in gastric inflammation and in the progression of gastric cancer induced by Helicobacter pylori (H. pylori) infection. The association of CXCL8, CXC Chemokine Receptor 1 (CXCR1), and CXC Chemokine Receptor 2 (CXCR2) polymorphisms with H. pylori infection and gastric cancer progression needs to be investigated in a population within an enigma area consisting of multiple ethnicities, such as Thailand. To analyze the relative risk of H. pylori infection and gastric cancer among Thai gastroduodenal patients, gene polymorphisms in CXCL8 (promoter region -251) and in CXCR1 and CXCR2 (receptors for CXCL8) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific-PCR (AS-PCR). We also determined the presence of cytotoxin-associated gene A (cagA) in Thai patients with H. pylori infection. Correlation between the CXCL8 (-251) polymorphism and CXCL8 gene expression was evaluated by quantitative reverse transcriptase-PCR (qRT-PCR). We found a significant association between the T/A and A/A genotypes of CXCL8 (-251) with H. pylori infection. However, no significant correlation was found between the CXCR1 (+2607) and CXCR2 (+1208) gene polymorphisms with H. pylori infection among Thai gastroduodenal subjects. Within the H. pylori-infected group of Thai gastroduodenal patients, no significant differences in cagA were observed. In addition, the A/A genotype of CXCL8 (-251) significantly correlated with the risk of gastric cancer and correlated with higher CXCL8 gene expression levels in Thai gastroduodenal patients. These results suggest that CXCL8 (-251) polymorphisms are associated with H. pylori infection, an increased risk of stronger inflammatory responses, and gastric cancer in Thai gastroduodenal patients.  


Author(s):  
Hazim Abdul Rahman Alhit

Editorial: Helicobacter pylori is a micro-aerophilic, helical-form gramnegative aggressive bacteria. Accordingly, the idiom “Helico” intimates its helical appearance, “bacter” symbolizes bacteria, while “pylori” denotes stomach due to the first and common site of this bacteria living. Further, Marshall B. and Warren R. observed and described it in 1982. Then, the followed investigators studied this bacterium in detail with its consequences and complexities [1]. Gastric upset (Indigestion), dyspepsia: means impaired gastric digestion. Accordingly, the patient complains of upper abdominal pain, heartburn, belching, nausea, even feeling earlier gastric fullness than expected while eating. Furthermore, there are many causes of indigestion like gastroesophageal reflux disease, ulcer disease, gastritis, and even gastric cancer. Hence, unexplained recent onset dyspepsia in older people may need additional examinations. Moreover, one of the common causes is Helicobacter pylori infection, which needs laboratory and endoscopic examination [2]. Argument Many theories investigated the etiology and pathogenesis of Helicobacter pylori infection, concerning chronic or acute gastritis. Hence, gastric upset is the main presentation of both types of gastritis. Evidences The genotype is valuable in determining the dominant Helicobacter pylori strains as the isolates were different genetically plus heterogeneous distribution. Accordingly, the vac and cag markers operate a significant function in defining clinical consequences. These virulence agents are present in a subset of Helicobacter pylori strains isolates like cagA, iceA, vacA, and ureC. Moreover, the cagA causes cytotoxins induction by the gastric epithelial cell as Interleukin 8 [3]. The molecular intercommunication researches exhibit that the act of acarus calamus in hindering biofilm formation in Helicobacter pylori is due to the inhibitory impact of phytobio-active component, β-sitosterol, on the quorum sensing molecules-ToxB, PhnB, DnaA, plus Sip. Consequently, this opinion may suggest the molecular mechanism of Helicobacter pylori in producing the acidrelated complaints and gives a clue to a new therapy [4]. Helicobacter pylori infection causes lncRNA risk impression linked to H. pylori in gastric cancer patients and can prognosticate the prediction of these patients [5]. There was a close relationship between raised serum IgE levels in Helicobacter pylori infected patients [6]. Counterargument The laboratory investigations of Helicobacter pylori infection depend on several factors like the fluctuations of serum antibody titers in a time series, the antigene detection in stool tests, the false-positive results of lab tests, or the manner of endoscopic biopsy collection. Furthermore, other factors like the variations in Cytotoxin-Associated Gene A (CagA) in East Asian patients. Moreover, the gastric nodularity or atrophy, the patient’s age, the severity of the gastric mucosal infection are causes of variations in Helicobacter pylori detection at the time of the investigation [7]. Refutation The significant markers of H. pylori, the presence of the vacuolating cytotoxin (vacA), the cytotoxin-associated gene A (cagA), which induced by the direct communication with gastric epithelium factor antigen (iceA gene), and the presence of urease C gene (ureC). Consequently, all these factors play the principal factors in deciding the gastric consequences of Helicobacter infections. Conclusion Helicobacter pylori induce gastric upset by several mechanisms to form numerous Gastric diseases.


2017 ◽  
Vol 7 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Banu N Şirvan ◽  
Merve K Usta ◽  
Nuray U Kızılkan ◽  
Nafiye Urgancı

ABSTRACT Aim We aimed to evaluate the role of the addition of Bifidobacterium lactis-containing synbiotic to the triple therapy in the case of Helicobacter pylori eradication, the dyspeptic symptoms, and reducing the side effects of antibiotics. Materials and methods A total of 104 children aged between 5 and 17 years, who were histopathologically diagnosed with H. pylori were enrolled in this study, of whom 100 were included in the analysis. Patients were randomly classified into two groups. In the first group, 50 patients were administered amoxicillin + clarithromycin + lansoprazole for 14 days and B. lactis-containing synbiotic. In the second group, 50 patients were treated with the standard triple therapy. All patients were given information after completion of therapy. Results H. pylori eradication was achieved in 88% in group I who received standard therapy with additional synbiotic and 72% in group II (p = 0.046). The number of patients in the second group who suffered from abdominal pain between the 3rd and 14th day of the treatment was higher (p < 0.05). The addition of probiotics to the triple therapy significantly reduced the frequency of diarrhea, but no significant difference was detected in the frequency of metallic taste (p = 0.04, p = 0.418 respectively). Conclusion The addition of synbiotic to the triple therapy is effective for eradicating H. pylori infection in children and is usually helpful to reduce or eliminate dyspeptic symptoms like abdominal pain, diarrhea, and vomiting. This study suggest that improved tolerance to the eradication treatment also reduces the treatment failure by adding probiotics and encourages the future study using probiotic supplementation in H. pylori treatment. How to cite this article Şirvan BN, Usta MK, Kızılkan NU, Urgancı N. Are Synbiotics added to the Standard Therapy to eradicate Helicobacter Pylori in Children Beneficial? A Randomized Controlled Study. Euroasian J Hepato-Gastroenterol 2017;7(1):17-22.


2019 ◽  
Vol 58 (3) ◽  
Author(s):  
Rajagopalan Saranathan ◽  
Michael H. Levi ◽  
Alice R. Wattam ◽  
Adel Malek ◽  
Emmanuel Asare ◽  
...  

ABSTRACT The emergence of drug resistance in Helicobacter pylori has resulted in a greater need for susceptibility-guided treatment. While the alleles associated with resistance to clarithromycin and levofloxacin have been defined, there are limited data regarding the molecular mechanisms underlying resistance to other antimicrobials. Using H. pylori isolates from 42 clinical specimens, we compared phenotypic and whole-genome sequencing (WGS)-based detection of resistance. Phenotypic resistance correlated with the presence of alleles of 23S rRNA (A2142G/A2143G) for clarithromycin (kappa coefficient, 0.84; 95% confidence interval [CI], 0.67 to 1.0) and gyrA (N87I/N87K/D91Y/D91N/D91G/D99N) for levofloxacin (kappa coefficient, 0.90; 95% CI, 0.77 to 1.0). Phenotypic resistance to amoxicillin in three isolates correlated with mutations in pbp1, pbp2, and/or pbp3 within coding regions near known amoxicillin binding motifs. All isolates were phenotypically susceptible to tetracycline, although four bore a mutation in 16S rRNA (A926G). For metronidazole, nonsense mutations and R16H substitutions in rdxA correlated with phenotypic resistance (kappa coefficient, 0.76; 95% CI, 0.56 to 0.96). Previously identified mutations in the rpoB rifampin resistance-determining region (RRDR) were not present, but 14 novel mutations outside the RRDR were found in rifampin-resistant isolates. WGS also allowed for strain lineage determination, which may be important for future studies in associating precise MICs with specific resistance alleles. In summary, WGS allows for broad analyses of H. pylori isolates, and our findings support the use of WGS for the detection of clarithromycin and levofloxacin resistance. Additional studies are warranted to better define mutations conferring resistance to amoxicillin, tetracycline, and rifampin, but combinatorial analyses for rdxA gene truncations and R16H mutations have utility for determining metronidazole resistance.


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