Helicobacter pylori protein response to human bile stress

The ability of Helicobacter pylori to tolerate bile is likely to be important for its colonization and survival in the gastrointestinal tract of humans. As bile can be acidified after reflux into the low pH of the human stomach, the inhibitory effect of fresh human bile with normal appearance on H. pylori before and after acidification was tested first. The results showed that acidification of bile attenuated its inhibitory activity towards H. pylori. Next, the protein profiles of H. pylori under human bile and acidified bile stress were obtained by two-dimensional electrophoresis. Protein spots with differential expression were identified using tandem matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that the changes in proteomic profiles under bile and acidified bile stress were similar when compared with that of normal H. pylori. Expression of 28 proteins was found to be modulated, with the majority being induced during bile or acidified bile exposure. These proteins included molecular chaperones, proteins involved in iron storage, chemotaxis protein, enzymes related to energy metabolism and flagellar protein. These results indicate that H. pylori responds to bile and acidified bile stress through multiple mechanisms involving many signalling pathways.

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Helicobacter pylori FlhB processing-deficient variants affect flagellar assembly but not flagellar gene expression

Microbiology ◽

10.1099/mic.0.022806-0 ◽

2009 ◽

Vol 155 (4) ◽

pp. 1170-1180 ◽

Cited By ~ 16

Author(s):

Todd G. Smith ◽

Lara Pereira ◽

Timothy R. Hoover

Keyword(s):

Helicobacter Pylori ◽

Substrate Specificity ◽

Reporter Genes ◽

Inhibitory Effect ◽

Protein Export ◽

Flagellar Gene ◽

Wild Type ◽

Flagellar Assembly ◽

Flagellar Protein ◽

H Pylori

Regulation of the Helicobacter pylori flagellar gene cascade involves the transcription factors σ 54 (RpoN), employed for expression of genes required midway through flagellar assembly, and σ 28 (FliA), required for expression of late genes. Previous studies revealed that mutations in genes encoding components of the flagellar protein export apparatus block expression of the H. pylori RpoN and FliA regulons. FlhB is a membrane-bound component of the export apparatus that possesses a large cytoplasmic domain (FlhBC). The hook length control protein FliK interacts with FlhBC to modulate the substrate specificity of the export apparatus. FlhBC undergoes autocleavage as part of the switch in substrate specificity. Consistent with previous reports, deletion of flhB in H. pylori interfered with expression of RpoN-dependent reporter genes, while deletion of fliK stimulated expression of these reporter genes. In the ΔflhB mutant, disrupting fliK did not restore expression of RpoN-dependent reporter genes, suggesting that the inhibitory effect of the ΔflhB mutation is not due to the inability to export FliK. Amino acid substitutions (N265A and P266G) at the putative autocleavage site of H. pylori FlhB prevented processing of FlhB and export of filament-type substrates. The FlhB variants supported wild-type expression of RpoN- and FliA-dependent reporter genes. In the strain producing FlhBN265A, expression of RpoN- and FliA-dependent reporter genes was inhibited when fliK was disrupted. In contrast, expression of these reporter genes was unaffected or slightly stimulated when fliK was disrupted in the strain producing FlhBP266G. H. pylori HP1575 (FlhX) shares homology with the C-terminal portion of FlhBC (FlhBCC) and can substitute for FlhBCC in flagellar assembly. Disrupting flhX inhibited expression of a flaB reporter gene in the wild-type but not in the ΔfliK mutant or strains producing FlhB variants, suggesting a role for FlhX or FlhBCC in normal expression of the RpoN regulon. Taken together, these data indicate that the mechanism by which the flagellar protein export apparatus exerts control over the H. pylori RpoN regulon is complex and involves more than simply switching substrate specificity of the flagellar protein export apparatus.

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Myricetin as an Antivirulence Compound Interfering with a Morphological Transformation into Coccoid Forms and Potentiating Activity of Antibiotics against Helicobacter pylori

International Journal of Molecular Sciences ◽

10.3390/ijms22052695 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2695

Author(s):

Paweł Krzyżek ◽

Paweł Migdał ◽

Emil Paluch ◽

Magdalena Karwańska ◽

Alina Wieliczko ◽

...

Keyword(s):

Helicobacter Pylori ◽

Biofilm Formation ◽

Inhibitory Effect ◽

Morphological Transformation ◽

High Tendency ◽

Minimal Inhibitory Concentrations ◽

Coccoid Form ◽

Stomach Diseases ◽

Fold Reduction ◽

H Pylori

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

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The Gastro-protective Effect of Ginger (Zingiber officinale Roscoe) in Helicobacter pylori Positive Functional Dyspepsia

Advanced Pharmaceutical Bulletin ◽

10.15171/apb.2019.038 ◽

2019 ◽

Vol 9 (2) ◽

pp. 321-324 ◽

Cited By ~ 2

Author(s):

Vahideh Ebrahimzadeh Attari ◽

Mohammad Hosein Somi ◽

Mohammad Asghari Jafarabadi ◽

Alireza Ostadrahimi ◽

Seyed-Yaghob Moaddab ◽

...

Keyword(s):

Clinical Trials ◽

Helicobacter Pylori ◽

Functional Dyspepsia ◽

Zingiber Officinale ◽

Complementary Therapy ◽

Positive Functional ◽

Before And After ◽

Rome Iii ◽

Ginger Powder ◽

H Pylori

Purpose: The present study aimed to assess the effect of ginger (Zingiber officinale) powder supplementation on Helicobacter pylori eradication and improvement of dyspeptic symptoms in patients with H. pylori positive functional dyspepsia (FD). Methods: During this pilot study 15 patients with H. pylori positive FD received 3 g/d ginger powder as three 1-g tablets for 4-weeks. Dyspepsia symptoms were asked before and after the intervention using a questionnaire based on the Rome III criteria. H. pylori eradication was also assessed by a non-invasive stool antigen (HpSAg) test. Results: Ginger consumption accompanied by significant H. pylori eradication rate of 53.3% (P = 0.019) and the odds ratio (95% CI) was 8 (1.07 to 357.14). Moreover, our results showed significant changes in most of the dyspepsia symptoms after ginger supplementation. Conclusion: According to our findings, Z. officinale can be considered as a useful complementary therapy for FD. However, due to the small number of clinical trials in this area, further welldesigned clinical trials are needed to explicitly talk about its effectiveness especially about the eradication of H. pylori.

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Identification of chemical constituents from the bark of Larix kaempferi and their tyrosinase inhibitory effect

Holzforschung ◽

10.1515/hf-2018-0267 ◽

2019 ◽

Vol 73 (7) ◽

pp. 637-643 ◽

Cited By ~ 2

Author(s):

Yuya Kakumu ◽

Kosei Yamauchi ◽

Tohru Mitsunaga

Keyword(s):

Chemical Constituents ◽

Inhibitory Effect ◽

Positive Control ◽

Hydroxyl Group ◽

Larix Kaempferi ◽

Tyrosinase Inhibition ◽

Ionization Time ◽

Flight Mass Spectrometry ◽

Potent Inhibition ◽

Forestry Production

Abstract Most of the wood bark produced by the forestry production is discarded in spite of containing many kinds of the phytochemical ingredients. The aim of the present study was to identify secondary metabolites from the bark of Larix kaempferi generated as waste material and evaluate their potential as cosmetic agents. Eighteen compounds, including a novel phenanthrene, 4,6,7-trihydroxyphenanthrene-2-O-β-D-glucopyranoside (16), were isolated from the bark of L. kaempferi and identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and nuclear magnetic resonance (NMR). In addition, the tyrosinase inhibitory activity of these compounds was evaluated. Procyanidin B7 (18) exhibited the most potent inhibition with IC50 values of 31.0 μM and 61.8 μM when using L-tyrosine and L-dopa as the substrate, respectively, which were similar to those of the positive control, kojic acid. Interestingly, quercetin-3-O-α-L-rhamnopyranoside (10) was shown to possess the tyrosinase inhibition although the other series of 3-glycoylated flavonols were not active, suggesting that the rhamnosyl group at C-3 and the hydroxyl group at C-3ʹ played an indispensable role in the anti-tyrosinase activity. These findings indicate that a number of constituents from L. kaempferi bark may have potential as additives in cosmetics.

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Effects of vaccination by a recombinant antigen ureB138 (a segment of the β-subunit of urease) against Helicobacter pylori infection

Journal of Medical Microbiology ◽

10.1099/jmm.0.47061-0 ◽

2007 ◽

Vol 56 (6) ◽

pp. 847-853 ◽

Cited By ~ 12

Author(s):

Fumiko Morihara ◽

Ryoji Fujii ◽

Emi Hifumi ◽

Akira Nishizono ◽

Taizo Uda

Keyword(s):

Helicobacter Pylori ◽

Mononuclear Cells ◽

Gel Filtration ◽

Immunohistochemical Analysis ◽

Inhibitory Effect ◽

Enzymic Activity ◽

Amino Acid Sequences ◽

Glutathione S Transferase ◽

Important Region ◽

H Pylori

Helicobacter pylori has to counteract acidity during colonization in the stomach. The most important region for the enzymic activity of H. pylori urease, consisting of 138 aa (ureB138), was determined by a comparison of the homology of amino acid sequences, and a structural analysis, between urease of H. pylori and various other species. This region was expressed in Escherichia coli as a fusion protein with glutathione S-transferase (GST), which was cleaved by PreScission protease between the GST moiety and ureB138. The ureB138 protein was then purified by gel filtration. The polyclonal antibody (pAb) induced by immunization with the purified ureB138 could suppress urease activity by about 50 %, while the pAb against the H. pylori urease did not show any inhibitory effect at all. Immunohistochemical analysis indicated that the ureB138-specific pAb specifically recognized the H. pylori infecting human gastric tissues. The effects of vaccination of recombinant ureB138 against infection by this organism were also examined. Specific IgG and IgA antibodies against H. pylori urease were induced in the serum of mice immunized with ureB138. A reduction in the number of colonizing H. pylori was observed in mice treated with ureB138 compared to ones treated with BSA and infection control mice. In the protected mice, severe gastritis characterized by marked infiltration of mononuclear cells was noted compared with the gastritis observed in unprotected mice. Immunohistochemical staining for IgA in gastric mucosa showed that the number of mice positively stained with IgA was significantly higher in ureB138-vaccinated mice than in non-vaccinated mice. This indicates that local IgA antibody and severe post-immunization gastritis correlate well with the protection of mice against H. pylori infection.

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CURCUMIN IN COMBINATION WITH TRIPLE THERAPY REGIMES AMELIORATES OXIDATIVE STRESS AND HISTOPATHOLOGIC CHANGES IN CHRONIC GASTRITIS-ASSOCIATED HELICOBACTER PYLORI INFECTION

Arquivos de Gastroenterologia ◽

10.1590/s0004-2803.201700000-18 ◽

2017 ◽

Vol 54 (3) ◽

pp. 177-182 ◽

Cited By ~ 18

Author(s):

Arezu JUDAKI ◽

Asghar RAHMANI ◽

Jalil FEIZI ◽

Khairollah ASADOLLAHI ◽

Mohammad Reza HAFEZI AHMADI

Keyword(s):

Oxidative Stress ◽

Helicobacter Pylori ◽

Triple Therapy ◽

Chronic Gastritis ◽

Therapy Group ◽

Standard Triple Therapy ◽

Before And After ◽

Total Antioxidant ◽

H Pylori ◽

Triple Regimen

ABSTRACT BACKGROUND Helicobacter pylori (H. pylori) gastric infection is a main cause of inflammatory changes and gastric cancers. OBJECTIVE The aim of this study was finding the effects of curcumin on oxidative stress and histological changes in chronic gastritis associated with H. pylori. METHODS In a randomized clinical trial, patients were divided into two groups: a standard triple therapy group and triple therapy with curcumin group. Endoscopic and histological examinations were measured for all patients before and after 8 weeks. RESULTS Triple therapy with curcumin treatment group significantly decreased malondialdehyde markers, glutathione peroxides and increased total antioxidant capacity of the gastric mucosa at the end of study compared to baseline and triple regimen groups. In addition, the oxidative damage to DNA was significantly decreased in triple therapy with curcumin group at the end of study compared to baseline and compared to triple therapy (P<0.05 for both). Triple therapy group in combination with Curcumin significantly decreased all active, chronic and endoscopic inflammation scores of patients compared to the baseline and triple therapy group (P<0.05 for both). The eradication rate by triple therapy + curcumin was significantly increased compared to triple therapy alone (P<0.05). CONCLUSION Curcumin can be a useful supplement to improve chronic inflammation and prevention of carcinogenic changes in patients with chronic gastritis associated by H. pylori.

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Host Wnt/β-catenin pathway triggered by Helicobacter pylori correlates with regression of gastric intestinal metaplasia after H. pylori eradication

Journal of Medical Microbiology ◽

10.1099/jmm.0.007310-0 ◽

2009 ◽

Vol 58 (5) ◽

pp. 567-576 ◽

Cited By ~ 18

Author(s):

Kuei-Hsiang Hung ◽

Jiunn-Jong Wu ◽

Hsiao-Bai Yang ◽

Li-Ju Su ◽

Bor-Shyang Sheu

Keyword(s):

Helicobacter Pylori ◽

Intestinal Metaplasia ◽

Glycogen Synthase ◽

Nucleotide Polymorphisms ◽

Ags Cells ◽

Gastric Intestinal Metaplasia ◽

Before And After ◽

Cox 2 ◽

H Pylori ◽

High Level

Helicobacter pylori eradication can reverse gastric intestinal metaplasia (IM) in some but not all patients. H. pylori induces high levels of nuclear β-catenin staining in IM tissues, as well as overexpression of cyclooxygenase-2 (COX-2). This study investigated whether the Wnt/β-catenin pathway plays a role in IM regression following H. pylori eradication. Sixty-five H. pylori-infected patients with IM who had achieved successful H. pylori eradication provided paired gastric samples before and after eradication to analyse the persistence of IM, and to assess COX-2 and nuclear β-catenin expression. The host genotypes of single nucleotide polymorphisms (SNPs) of the COX-2, β-catenin (CTNNB1) and adenomatous polyposis coli (APC) genes were analysed. In addition, expression of β-catenin, E-cadherin and phosphorylated and unphosphorylated glycogen synthase kinase 3β (GSK-3β) in cell lines challenged with H. pylori isolates from patients with and without IM persistence was compared by immunoanalysis. After a mean 33.9-month follow-up after H. pylori eradication, 44 patients (67.7 %) with IM persistence had a higher rate of high-level nuclear β-catenin expression in IM tissue than those without IM persistence (P=0.008). The patients with IM persistence had a higher rate of AA, GG and AA APC SNP genotypes at positions 4479, 5268 and 5465, respectively, than the patients without IM persistence (P=0.022). The H. pylori isolates from the patients with IM regression after H. pylori eradication induced more phospho-GSK-3β in AGS cells than isolates from patients with IM persistence (P=0.011). It is likely that interactions with H. pylori and the patient's Wnt/β-catenin genetic predisposition determine the outcome of IM persistence following H. pylori eradication.

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Helicobacter pylori FlhB Function: the FlhB C-Terminal Homologue HP1575 Acts as a “Spare Part” To Permit Flagellar Export When the HP0770 FlhBCC Domain Is Deleted

Journal of Bacteriology ◽

10.1128/jb.00263-06 ◽

2006 ◽

Vol 188 (21) ◽

pp. 7531-7541 ◽

Cited By ~ 11

Author(s):

Matthew E. Wand ◽

R. Elizabeth Sockett ◽

Katy J. Evans ◽

Neil Doherty ◽

Paul M. Sharp ◽

...

Keyword(s):

Helicobacter Pylori ◽

Spare Part ◽

Significant Similarity ◽

Flagellar Assembly ◽

Processing Event ◽

Processing Site ◽

Flagellar Protein ◽

H Pylori ◽

Export Protein

ABSTRACT In Helicobacter pylori 26695, a gene annotated HP1575 encodes a putative protein of unknown function which shows significant similarity to part of the C-terminal domain of the flagellar export protein FlhB. In Salmonella enterica, this part (FlhBCC) is proteolytically cleaved from the full-length FlhB, a processing event that is required for flagellar protein export and, thus, motility. The role of FlhB (HP0770) and its C-terminal homologue HP1575 was studied in H. pylori using a range of nonpolar deletion mutants defective in HP1575, HP0770, and the CC domain of HP0770 (HP0770CC). Deletion of HP0770 abolished swimming motility, whereas mutants carrying a deletion of either HP1575 or HP0770CC retained their ability to swim. An H. pylori strain containing deletions in both HP1575 and HP0770CC was nonmotile and did not produce flagella, suggesting that at least one of the two proteins had to be present for flagellar assembly to occur. Indeed, motility was restored when HP1575 was reintroduced into this strain immediately downstream of, but not fused to, the truncated HP0770 gene. Thus, HP1575 can functionally replace HP0770CC in this background. Like FlhB in S. enterica, HP0770 appeared to be proteolytically processed at a conserved NPTH processing site. However, mutation of the proline contained within the NPTH site of HP0770 did not affect motility and flagellar assembly, although it clearly interfered with processing when the protein was heterologously produced in Escherichia coli.

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Essential Role of Ferritin Pfr in Helicobacter pylori Iron Metabolism and Gastric Colonization

Infection and Immunity ◽

10.1128/iai.70.7.3923-3929.2002 ◽

2002 ◽

Vol 70 (7) ◽

pp. 3923-3929 ◽

Cited By ~ 80

Author(s):

Barbara Waidner ◽

Stefan Greiner ◽

Stefan Odenbreit ◽

Holger Kavermann ◽

Jyoti Velayudhan ◽

...

Keyword(s):

Helicobacter Pylori ◽

Iron Metabolism ◽

Essential Element ◽

Iron Starvation ◽

Iron Storage ◽

Gastric Colonization ◽

H Pylori ◽

Iron Pool

ABSTRACT The reactivity of the essential element iron necessitates a concerted expression of ferritins, which mediate iron storage in a nonreactive state. Here we have further established the role of the Helicobacter pylori ferritin Pfr in iron metabolism and gastric colonization. Iron stored in Pfr enabled H. pylori to multiply under severe iron starvation and protected the bacteria from acid-amplified iron toxicity, as inactivation of the pfr gene restricted growth of H. pylori under these conditions. The lowered total iron content in the pfr mutant, which is probably caused by decreased iron uptake rates, was also reflected by an increased resistance to superoxide stress. Iron induction of Pfr synthesis was clearly diminished in an H. pylori feoB mutant, which lacked high-affinity ferrous iron transport, confirming that Pfr expression is mediated by changes in the cytoplasmic iron pool and not by extracellular iron. This is well in agreement with the recent discovery that iron induces Pfr synthesis by abolishing Fur-mediated repression of pfr transcription, which was further confirmed here by the observation that iron inhibited the in vitro binding of recombinant H. pylori Fur to the pfr promoter region. The functions of H. pylori Pfr in iron metabolism are essential for survival in the gastric mucosa, as the pfr mutant was unable to colonize in a Mongolian gerbil-based animal model. In summary, the pfr phenotypes observed give new insights into prokaryotic ferritin functions and indicate that iron storage and homeostasis are of extraordinary importance for H. pylori to survive in its hostile natural environment.

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Impact of Helicobacter pylori Eradication Therapy on Platelet Counts in Patients With Chronic Idiopathic Thrombocytopenic Purpura

Global Journal of Health Science ◽

10.5539/gjhs.v8n7p35 ◽

2015 ◽

Vol 8 (7) ◽

pp. 35 ◽

Cited By ~ 2

Author(s):

Mohamadreza Amiri

Keyword(s):

Helicobacter Pylori ◽

Platelet Count ◽

Eradication Therapy ◽

Current Treatment ◽

Thrombocytopenic Purpura ◽

Stool Antigen Test ◽

Platelet Counts ◽

Before And After ◽

History Of ◽

H Pylori

This study was a before and after clinical evaluation of Helicobacter pylori eradication on platelet counts in a group of 23 patients with chronic Idiopathic (Autoimmune) thrombocytopenic purpura (CITP). H. pylori infection was identified in patients by a 13C-urea breath test and confirmed by an H. pylori stool antigen test. Eradication was conducted in patients testing positive. Infected (n = 10) and uninfected (n = 13) patient groups did not differ with respect to age, gender, history of previous splenectomy, treatment with anti-D, current treatment with corticosteroids, or initial platelet counts. H pylori eradication was successful in eight infected CITP patients, with two patients not responsive to treatment. Compared to the uninfected group, patients in the infected group who responded to eradication therapy had significantly increased platelet counts after six months (56.2 ± 22.2 vs. 233 ± 85.6 ×103 million cells/L; P < 0.01), whereas platelet counts in the non-responding patients and uninfected group did not differ after this period of time. H. pylori eradication promotes significant platelet count improvement in patients with CITP. Thus, all patients with CITP should be tested and treated for H. pylori infections.

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