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1.
J Med Microbiol ; 69(2): 218-227, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32011229

RESUMO

Introduction. Gastric cancer is a health disparity in the Alaska Native people. The incidence of Helicobacter pylori infection, a risk factor for non-cardia gastric adenocarcinoma, is also high. Gastric cancer is partially associated with the virulence of the infecting strain.Aim. To genotype the vacA s, m and i and cag pathogenicity island (cagPAI) genes in H. pylori from Alaskans and investigate associations with gastropathy.Methodology. We enrolled patients with gastritis, peptic ulcer disease (PUD) and intestinal metaplasia (IM) in 1998-2005 and patients with gastric cancer in 2011-2013. Gastric biopsies were collected and cultured and PCR was performed to detect the presence of the right and left ends of the cagPAI, the cagA, cagE, cagT and virD4 genes and to genotype the vacA s, m and i regions.Results. We recruited 263 people; 22 (8 %) had no/mild gastritis, 121 (46 %) had moderate gastritis, 40 (15%) had severe gastritis, 38 (14 %) had PUD, 30 (11 %) had IM and 12 (5 %) had gastric cancer. H. pylori isolates from 150 (57%) people had an intact cagPAI; those were associated with a more severe gastropathy (P≤0.02 for all comparisons). H. pylori isolates from 77 % of people had either the vacA s1/i1/m1 (40 %; 94/234) or s2/i2/m2 (37 %; 86/234) genotype. vacA s1/i1/m1 was associated with a more severe gastropathy (P≤0.03 for all comparisons).Conclusions. In this population with high rates of gastric cancer, we found that just over half of the H. pylori contained an intact cagPAI and 40 % had the vacA s1/i1/m1 genotype. Infection with these strains was associated with a more severe gastropathy.


Assuntos
Proteínas de Bactérias/genética , Ilhas Genômicas , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alaska , Nativos do Alasca/estatística & dados numéricos , Proteínas de Bactérias/metabolismo , Feminino , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/microbiologia , Neoplasias Gástricas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Adulto Jovem
2.
Biochemistry (Mosc) ; 85(2): 234-240, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32093599

RESUMO

Helicobacter pylori is an important human pathogen that causes gastritis, gastric and duodenal ulcers, and gastric cancer. O-polysaccharides of H. pylori lipopolysaccharide (LPS) are composed of (ß1→3)-poly(N-acetyllactosamine) (polyLacNAc) decorated with multiple α-L-fucose residues. In many strains, their terminal LacNAc units are mono- or di-fucosylated to mimic Lewis X (Lex) and/or Lewis Y (Ley) oligosaccharides. The studies in rhesus macaques as a model of human infection by H. pylori showed that this bacterium adapts to the host during colonization by expressing host Lewis antigens. Here, we characterized LPS from H. pylori strains used in the previous study, including the parental J166 strain and the three derivatives (98-149, 98-169, and 98-181) isolated from rhesus macaques after long-term colonization. Chemical and NMR spectroscopic analyses of the LPS showed that the parent strain expressed Lex, Ley, and H type 1 terminal oligosaccharide units. The daughter strains were similar to the parental one in the presence of the same LPS core and fucosylated polyLacNAc chain of the same length but differed in the terminal oligosaccharide units. These were Lex in the isolates 98-149 and 98-169, which corresponded to the Lea phenotype of the host animals, and Ley was found in the 98-181 isolate from the macaque characterized by the Leb phenotype. As Lea and Leb are isomers of Lex and Ley, respectively, the observed correlation confirmed adaptation of the expression of terminal oligosaccharide units in H. pylori strains to the properties of the host gastric mucosa. The 98-181 strain also acquired glucosylation of the polyLacNAc chain and was distinguished by a lower expression of fucosylated internal LacNAc units (internal Lex) as a result of decoration of polyLacNAc with ß-glucopyranose, which may also play a role in the bacterial adaptation.


Assuntos
Helicobacter pylori/química , Lipopolissacarídeos/química , Macaca mulatta/microbiologia , Oligossacarídeos/genética , Polissacarídeos/metabolismo , Animais , Glicosilação , Helicobacter pylori/metabolismo , Lipopolissacarídeos/isolamento & purificação , Lipopolissacarídeos/metabolismo , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Fenótipo , Polissacarídeos/química
3.
J Basic Microbiol ; 60(3): 207-215, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31960983

RESUMO

The treatment of Helicobacter pylori usually fails due to their ability to form biofilms and resistance to antibiotics. This might potentially lead to gastric carcinoma and mucosa-associated lymphoid tissue lymphoma. In the present study, we elucidate the potential role of N-acylhomoserine lactonase stabilized silver nanoparticles (AiiA-AgNPs) in treating biofilms produced by H. pylori. AiiA-AgNPs inhibited quorum sensing (QS) by degradation of QS molecules, thereby reducing biofilm formation, urease production, and altering cell surface hydrophobicity of H. pylori. AiiA-AgNPs showed no cytotoxic effects on RAW 264.7 macrophages at the effective concentration (1-5 µM) of antibiofilm activity. In addition, AiiA-AgNP in high concentration (80-100 µM) exhibited cytotoxicity against HCT-15 carcinoma cells, depicting its therapeutic role in treating cancer.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Hidrolases de Éster Carboxílico/farmacologia , Helicobacter pylori/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Prata/farmacologia , Animais , Antibacterianos/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Hidrolases de Éster Carboxílico/química , Linhagem Celular Tumoral , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Helicobacter pylori/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Nanopartículas Metálicas/química , Camundongos , Células RAW 264.7 , Prata/química , Urease/metabolismo
4.
Chem Commun (Camb) ; 56(3): 344-347, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31808481

RESUMO

Exploiting synergistic remote participation effects of acyl groups at the O3 and O6 positions was key to the complete α-selectivity during the total synthesis of the unique (1 → 2)- and (1 → 3)-linked α-oligoglucosides from the Helicobacter pylori O2 O-antigen. Acyl remote participation and solvent effects were found to counteract during α-stereoselective glucosylations for the first time. The resulting antigen is a lead for the development of a carbohydrate-conjugate vaccine.


Assuntos
Helicobacter pylori/metabolismo , Antígenos O/química , Oligossacarídeos/síntese química , Oligossacarídeos/química , Sorogrupo , Solventes/química , Estereoisomerismo , Vacinas Conjugadas/química
5.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31712269

RESUMO

Helicobacter pylori colonizes the stomach in about half of the world's population. H. pylori strains containing the cag pathogenicity island (cag PAI) are associated with a higher risk of gastric adenocarcinoma or peptic ulcer disease than cag PAI-negative strains. The cag PAI encodes a type IV secretion system (T4SS) that mediates delivery of the CagA effector protein as well as nonprotein bacterial constituents into gastric epithelial cells. H. pylori-induced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and interleukin-8 (IL-8) secretion are attributed to T4SS-dependent delivery of lipopolysaccharide metabolites and peptidoglycan into host cells, and Toll-like receptor 9 (TLR9) activation is attributed to delivery of bacterial DNA. In this study, we analyzed the bacterial energetic requirements associated with these cellular alterations. Mutant strains lacking Cagα, Cagß, or CagE (putative ATPases corresponding to VirB11, VirD4, and VirB4 in prototypical T4SSs) were capable of T4SS core complex assembly but defective in CagA translocation into host cells. Thus, the three Cag ATPases are not functionally redundant. Cagα and CagE were required for H. pylori-induced NF-κB activation, IL-8 secretion, and TLR9 activation, but Cagß was dispensable for these responses. We identified putative ATP-binding motifs (Walker-A and Walker-B) in each of the ATPases and generated mutant strains in which these motifs were altered. Each of the Walker box mutant strains exhibited properties identical to those of the corresponding deletion mutant strains. These data suggest that Cag T4SS-dependent delivery of nonprotein bacterial constituents into host cells occurs through mechanisms different from those used for recruitment and delivery of CagA into host cells.


Assuntos
Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Células Epiteliais/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Sistemas de Secreção Tipo IV/genética , Sistemas de Secreção Tipo IV/metabolismo , Transporte Biológico , DNA Bacteriano/metabolismo , Humanos , Interleucina-8/metabolismo , Lipopolissacarídeos/metabolismo , NF-kappa B/metabolismo , Peptidoglicano/metabolismo , Receptor Toll-Like 9/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
6.
Helicobacter ; 25(2): e12678, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31880001

RESUMO

BACKGROUND: In this study, one Helicobacter pylori isolate, from gastric biopsy of a dyspeptic patient that turned into mucoid-coccoid (MC) form upon consecutive subcultures, was identified. The culturability, antibiotic resistance, and lipid contents of MC were compared with those of non-mucoid (NM) spiral H pylori. MATERIALS AND METHODS: Mucoid-coccoid and NM H pylori were subcultured on Brucella blood agar (BBA) and incubated under aerobic and microaerobic atmospheres at 37°C. Cultures were examined for colony characteristics and bacterial morphology after 1-3 days. The isolates were identified by biochemical tests and detection of H pylori-16S rDNA. Antibiogram was performed with currently used antibiotics for H pylori eradication. Cellular lipid contents were extracted and analyzed by gas chromatography. RESULTS: Compared with pin-pointed and glistening colonies of NM H pylori that appeared under microaerobic conditions, MC H pylori grew well in consecutive subcultures under aerobic and microaerobic atmospheres and produced white patches of mucoid colonies. MC exhibited coccoid and NM spiral morphology. Both isolates were catalase, oxidase, and urease positive and contained 16S rDNA. Compared with NM that was susceptible to almost all the antibiotics, MC was resistant to all the antibiotics. Lipid analyses showed high frequency of unsaturated fatty acids and cholesterol in MC. CONCLUSIONS: Coccoid forms with high fatty acid and cholesterol contents that show resistance to antibiotics might resist against other stressful conditions such as gastric acidity and immune response. Moreover, mucoid property may enhance resistance of coccoids to stresses. With mucoid-coccoid lifestyle, H pylori may establish a chronic infection refractory to antimicrobial therapy.


Assuntos
Helicobacter pylori/citologia , Helicobacter pylori/crescimento & desenvolvimento , Helicobacter pylori/isolamento & purificação , Colesterol/química , Resistência Microbiana a Medicamentos , Ácidos Graxos/química , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Humanos , Testes de Sensibilidade Microbiana
7.
Ann Lab Med ; 40(1): 68-71, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31432642

RESUMO

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.


Assuntos
Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Análise de Classes Latentes , Anticorpos Antibacterianos/sangue , Antígenos/análise , Fezes/química , Gastroscopia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Humanos , Sensibilidade e Especificidade
8.
PLoS One ; 14(12): e0224356, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31841502

RESUMO

It has become critical to detect Helicobacter pylori (H. pylori) infection due to the link to gastric cancer with some strains. These strains are also increasing in resistance to antibiotics with clarithromycin leading the way as the first line treatment. Resistance to clarithromycin has been shown to correlate with the A2142G, A2142C, and A2143G mutations on the rrl gene. In the last few decades, non-invasive specimens, such as stool, have been a reliable alternate to gastric biopsy for immunoassay tests. More recently, it has been proven feasible for stool to be used in molecular based tests. Many of the core laboratories in the United States need a high throughput sample preparation to run this test. Here, a high throughput assay is compared to a previously published manual sample prep H. pylori molecular based assay. Using the Magna Pure 96 (Roche), at least 96 stool species and 96 biopsy specimens can be tested in an 8-hour shift of a clinical lab. The high throughput sample prep had a positive percent agreement (PPA) of 87% compared to the manual sample prep using the same testing configuration. The genotype predictions from the high throughput assay matched genotype predictions from the manual sample prep with the same stool sample 92% of the time. A concordance rate of 89% was observed with genotype predictions from the high throughput assay of the same patient stool and biopsy. In stool samples from the high throughput assay, there was 100% concordance between the quantitative polymerase chain reaction (qPCR)-derived genomic prediction and DNA sequencing data. The high throughput workflow can get more patients tested faster in addition to detection of mutations associated with clarithromycin resistance.


Assuntos
Fezes/microbiologia , Helicobacter pylori/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Antibacterianos/farmacologia , Líquidos Corporais/química , Claritromicina/farmacologia , Claritromicina/uso terapêutico , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Fezes/química , Genótipo , Infecções por Helicobacter/complicações , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase/métodos
9.
Nat Commun ; 10(1): 5717, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31844047

RESUMO

Toll-like receptor TLR5 recognizes a conserved domain, termed D1, that is present in flagellins of several pathogenic bacteria but not in Helicobacter pylori. Highly virulent H. pylori strains possess a type IV secretion system (T4SS) for delivery of virulence factors into gastric epithelial cells. Here, we show that one of the H. pylori T4SS components, protein CagL, can act as a flagellin-independent TLR5 activator. CagL contains a D1-like motif that mediates adherence to TLR5+ epithelial cells, TLR5 activation, and downstream signaling in vitro. TLR5 expression is associated with H. pylori infection and gastric lesions in human biopsies. Using Tlr5-knockout and wild-type mice, we show that TLR5 is important for efficient control of H. pylori infection. Our results indicate that CagL, by activating TLR5, may modulate immune responses to H. pylori.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Receptor 5 Toll-Like/metabolismo , Sistemas de Secreção Tipo IV/metabolismo , Animais , Proteínas de Bactérias/imunologia , Biópsia , Modelos Animais de Doenças , Feminino , Mucosa Gástrica/imunologia , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Transdução de Sinais/imunologia , Receptor 5 Toll-Like/genética , Receptor 5 Toll-Like/imunologia , Sistemas de Secreção Tipo IV/imunologia
10.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(8): 744-749, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31638572

RESUMO

Objective To demonstrate HpaA can intensify the inflammatory response and gastric mucosa injury by IL-21 from induced T cell. Methods Biopsy specimens were taken from gastric mucosa of 56 patients with H.pylori infection before and after H.pylori radical elimination by endoscope. The levels of IL-21, matrix metalloproteinase-2 (MMP2) and MMP9 from the biopsy were detected by reverse transcription PCR and Western blot analysis. Meanwhile, the recombinant HpaA was cloned, expressed and purified to stimulate the magnetic cell sorting CD3+ T cells from healthy donors' peripheral blood mononuclear cells (PBMCs), and the level of IL-21 in the supernatant fluid was detected by ELISA. Thereafter, AGS cells were cultured and Western blot analysis was performed to detect the levels of MMP2 and MMP9 in the AGS cells with human IL-21 and anti-IL-21 antibody treatment for 24 hours. Results The protein levels of IL-21 and MMP2 and MMP9 in gastric mucosa infected with H. pylori was significantly higher than that in gastric mucosa after radical treatment of H. pylori. Meanwhile, the recombinant HpaA promoted IL-21 secretion by induced CD3+T cells in vitro. IL-21 stimulated the expression of MMP2 and MMP9 in AGS cells. When IL-21 was blocked by the antibody, the levels of MMP2 and MMP9 in AGS cells decreased significantly. Conclusion HpaA plays a significant role in the gastric mucosa injury caused by H.pylori infection through IL-21 from induced T cells.


Assuntos
Adesinas Bacterianas , Mucosa Gástrica , Interleucinas , Linfócitos T , Adesinas Bacterianas/metabolismo , Mucosa Gástrica/lesões , Mucosa Gástrica/fisiopatologia , Infecções por Helicobacter/imunologia , Infecções por Helicobacter/fisiopatologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Humanos , Interleucinas/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Linfócitos T/metabolismo
11.
World J Gastroenterol ; 25(35): 5220-5232, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31558869

RESUMO

Helicobacter pylori (H. pylori) is a Gram-negative bacterium with a number of virulence factors, such as cytotoxin-associated gene A, vacuolating cytotoxin A, its pathogenicity island, and lipopolysaccharide, which cause gastrointestinal diseases. Connexins function in gap junctional homeostasis, and their downregulation is closely related to gastric carcinogenesis. Investigations into H. pylori infection and the fine-tuning of connexins in cells or tissues have been reported in previous studies. Therefore, in this review, the potential mechanisms of H. pylori-induced gastric cancer through connexins are summarized in detail.


Assuntos
Carcinogênese/patologia , Conexinas/metabolismo , Infecções por Helicobacter/patologia , Helicobacter pylori/patogenicidade , Neoplasias Gástricas/patologia , Regulação para Baixo , Mucosa Gástrica/patologia , Regulação Neoplásica da Expressão Gênica , Ilhas Genômicas , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Neoplasias Gástricas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
12.
J Immunol Res ; 2019: 1394191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31485458

RESUMO

Recent research on cancer-associated microbial communities led to the accumulation of data on the interplay between bacteria, immune and tumor cells, the pathways of bacterial induction of carcinogenesis, and its meaningfulness for medicine. Microbial communities that have any kind of impact on tumor progression and microorganisms associated with tumors have been defined as oncobiome. Over the last decades, a number of studies were dedicated to Helicobacter pylori and its role in the progression of stomach tumors, so this correlation can be regarded as proven. Involvement of bacteria in the induction of lung cancer has been largely ignored for a long time, though some correlations between this type of cancer and lung microbiome were established. Despite the fact that in the present the microbial impact on lung cancer progression has many confirmations, the underlying mechanisms are poorly understood. Microorganisms can contribute to tumor initiation and progression through production of bacteriotoxins and other proinflammatory factors. The purpose of this review is to organize the available data on lung cancer microbiome and its role in malignant tumor progression.


Assuntos
Neoplasias Pulmonares/microbiologia , Pulmão/microbiologia , Microbiota , Carcinogênese/imunologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/patologia , Progressão da Doença , Microbioma Gastrointestinal , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Humanos , Pulmão/patologia , Neoplasias Pulmonares/imunologia , Neoplasias Gástricas/microbiologia
13.
PLoS Pathog ; 15(9): e1007972, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487328

RESUMO

The biogenesis of bacterial cell-envelope polysaccharides requires the translocation, across the plasma membrane, of sugar sub-units that are produced inside the cytoplasm. To this end, the hydrophilic sugars are anchored to a lipid phosphate carrier (undecaprenyl phosphate (C55-P)), yielding membrane intermediates which are translocated to the outer face of the membrane. Finally, the glycan moiety is transferred to a nascent acceptor polymer, releasing the carrier in the "inactive" undecaprenyl pyrophosphate (C55-PP) form. Thus, C55-P is generated through the dephosphorylation of C55-PP, itself arising from either de novo synthesis or recycling. Two types of integral membrane C55-PP phosphatases were described: BacA enzymes and a sub-group of PAP2 enzymes (type 2 phosphatidic acid phosphatases). The human pathogen Helicobacter pylori does not contain BacA homologue but has four membrane PAP2 proteins: LpxE, LpxF, HP0350 and HP0851. Here, we report the physiological role of HP0851, renamed HupA, via multiple and complementary approaches ranging from a detailed biochemical characterization to the assessment of its effect on cell envelope metabolism and microbe-host interactions. HupA displays a dual function as being the main C55-PP pyrophosphatase (UppP) and phosphatidylglycerol phosphate phosphatase (PGPase). Although not essential in vitro, HupA was essential in vivo for stomach colonization. In vitro, the remaining UppP activity was carried out by LpxE in addition to its lipid A 1-phosphate phosphatase activity. Both HupA and LpxE have crucial roles in the biosynthesis of several cell wall polysaccharides and thus constitute potential targets for new therapeutic strategies.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Helicobacter pylori/metabolismo , Sequência de Aminoácidos , Animais , Proteínas da Membrana Bacteriana Externa/fisiologia , Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Parede Celular/metabolismo , Proteínas de Ligação a DNA , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Feminino , Helicobacter pylori/patogenicidade , Camundongos , Camundongos Endogâmicos , Testes de Sensibilidade Microbiana , Fosfatidato Fosfatase , Monoéster Fosfórico Hidrolases/metabolismo , Fosfatos de Poli-Isoprenil/metabolismo , Polimixina B/farmacologia , Pirofosfatases/metabolismo , Estômago
14.
Elife ; 82019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31411564

RESUMO

Post-transcriptional regulation plays important roles to fine-tune gene expression in bacteria. In particular, regulation of type I toxin-antitoxin (TA) systems is achieved through sophisticated mechanisms involving toxin mRNA folding. Here, we set up a genetic approach to decipher the molecular underpinnings behind the regulation of a type I TA in Helicobacter pylori. We used the lethality induced by chromosomal inactivation of the antitoxin to select mutations that suppress toxicity. We found that single point mutations are sufficient to allow cell survival. Mutations located either in the 5' untranslated region or within the open reading frame of the toxin hamper its translation by stabilizing stem-loop structures that sequester the Shine-Dalgarno sequence. We propose that these short hairpins correspond to metastable structures that are transiently formed during transcription to avoid premature toxin expression. This work uncovers the co-transcriptional inhibition of translation as an additional layer of TA regulation in bacteria.


Assuntos
Toxinas Bacterianas/genética , Helicobacter pylori/metabolismo , Conformação de Ácido Nucleico , Dobramento de RNA , RNA Mensageiro/química , Sistemas Toxina-Antitoxina , Toxinas Bacterianas/biossíntese , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Viabilidade Microbiana , Mutação Puntual , Biossíntese de Proteínas , RNA Mensageiro/genética , Seleção Genética
15.
PLoS Biol ; 17(8): e3000395, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31465435

RESUMO

The gastric pathogen Helicobacter pylori requires a noncanonical cytosolic chemoreceptor transducer-like protein D (TlpD) for efficient colonization of the mammalian stomach. Here, we reconstituted a complete chemotransduction signaling complex in vitro with TlpD and the chemotaxis (Che) proteins CheW and CheA, enabling quantitative assays for potential chemotaxis ligands. We found that TlpD is selectively sensitive at micromolar concentrations to bleach (hypochlorous acid, HOCl), a potent antimicrobial produced by neutrophil myeloperoxidase during inflammation. HOCl acts as a chemoattractant by reversibly oxidizing a conserved cysteine within a 3His/1Cys Zn-binding motif in TlpD that inactivates the chemotransduction signaling complex. We found that H. pylori is resistant to killing by millimolar concentrations of HOCl and responds to HOCl in the micromolar range by increasing its smooth-swimming behavior, leading to chemoattraction to HOCl sources. We show related protein domains from Salmonella enterica and Escherichia coli possess similar reactivity toward HOCl. We propose that this family of proteins enables host-associated bacteria to sense sites of tissue inflammation, a strategy that H. pylori uses to aid in colonizing and persisting in inflamed gastric tissue.


Assuntos
Quimiotaxia/fisiologia , Helicobacter pylori/metabolismo , Receptores de Formil Peptídeo/metabolismo , Proteínas de Bactérias/metabolismo , Clareadores , Células Quimiorreceptoras/metabolismo , Fatores Quimiotáticos/metabolismo , Citosol/metabolismo , Citosol/fisiologia , Helicobacter pylori/fisiologia , Ácido Hipocloroso , Oxirredução , Receptores de Formil Peptídeo/fisiologia , Transdução de Sinais
16.
Life Sci ; 231: 116688, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31348950

RESUMO

The extended infection with Helicobacter pylori (H. pylori), one of the most frequent infectious agents in humans, may cause gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. During H. pylori infection, different kinds of inflammatory cells such as dendritic cells, macrophages, neutrophils, mast cells, eosinophils, T cells and B cells are accumulated into the stomach. The interactions between chemokines and their respective receptors recruit particular types of the leukocytes that ultimately determine the nature of immune response and therefore, have a main influence on the consequence of infection. The suitable production of chemokines especially in the early stages of H. pylori infection shapes appropriate immune responses that contribute to the H. pylori elimination. The unbalanced expression of the chemokines can contribute in the induction of inappropriate responses that result in the tissue damage or malignancy. Thus, chemokines and their receptors may be promising potential targets for designing the therapeutic strategies against various types H. pylori-related gastrointestinal disorders. In this review, a comprehensive explanation regarding the roles played by chemokines in H. pylori-mediated peptic ulcer, gastritis and gastric malignancies was provided while presenting the potential utilization of these chemoattractants as therapeutic elements.


Assuntos
Quimiocinas/metabolismo , Quimiocinas/farmacologia , Infecções por Helicobacter/terapia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Quimiocinas CXC/imunologia , Quimiocinas CXC/metabolismo , Mucosa Gástrica/metabolismo , Gastrite , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Helicobacter pylori/patogenicidade , Humanos , Receptores CXCR/imunologia , Receptores CXCR/metabolismo , Receptores de Quimiocinas/imunologia , Receptores de Quimiocinas/metabolismo , Estômago/patologia , Neoplasias Gástricas/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo
17.
Rom J Morphol Embryol ; 60(1): 219-225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31263848

RESUMO

OBJECTIVE: Ghrelin is believed to influence weight evolution after bariatric surgery. Helicobacter pylori (H. pylori) infection may influence ghrelin plasma levels by affecting the ghrelin-producing cells (GPC) in the stomach. The purpose of the study was to characterize the GPC distribution in the stomach in overweight patients and the influence of H. pylori infection on them. PATIENTS, MATERIALS AND METHODS: The study group included 21 obese patients undergoing bariatric surgery with ghrelin levels and anti-H. pylori antibodies previously measured, and upper gastrointestinal endoscopy with histological evaluation of H. pylori infection performed. Immunohistochemical expression of ghrelin was quantified in gastric resection specimens. RESULTS: The results showed a higher number of GPC in the obese women than in men (p>0.05). The highest number of GPC was detected in the gastric body, followed by the fundus and antral region (p<0.001). GPC number correlated inversely with anthropometric parameters: weight (p=0.011), body mass index (BMI) (p=0.017), waist circumference (WC) (p=0.066) was lower in patients with H. pylori infection (p>0.05) or gastritis (p>0.05), the number decreasing with the increase in depth of gastritis lesion (p>0.05). CONCLUSIONS: The present study fulfills the characterization of GPC in obese patients, showing a higher number in women than in men, their predominant location in the gastric body, and their relationship with the anthropometric parameters (weight, BMI, WC), H. pylori infection and gastritis lesions. These results open broad perspectives for a deeper understanding of the ghrelin involvement in the obesity pathogenic mechanism, associated or not with other gastric conditions.


Assuntos
Grelina/metabolismo , Helicobacter pylori/metabolismo , Obesidade/sangue , Estômago/fisiopatologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/patologia , Adulto Jovem
18.
Mater Sci Eng C Mater Biol Appl ; 103: 109733, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349519

RESUMO

Helicobacter pylori (H. pylori) immunosensor based on platinum nanoparticles/poly(3,4-ethylenedioxythiophene)/reduced graphene oxide (Ptnano/PEDOT/red-GOx) modified gold electrode (Au-ET) was stepwise fabricated for the detection of cytotoxin-associated gene A antibody (CagA antibody). H. pylori is a microaerophillic and a Gram-negative bacteria that causes gastric ulcer leading eventually to adenocarcinoma (gastric cancer) in the later stage. H. pylori colonizes inner lining of human stomach. The developed diagnostic sensing interface would allow H. pylori (stomach infection) detection in early stage and would be a great contribution in clinical laboratories. In order to fabricate the immunosensor, CagA antigen was immobilized over the Ptnano/PEDOT/red-GOx modified Au-ET. Afterwards, the modified electrode was used for immuno-sensing of H. pylori specific Cag A antibodies in serum. At lower voltage the modified Ptnano/PEDOT/red-GOx/Au-ET shows an amplified sensing at the interface that makes the sensor more sensitive and specific. CagA is a virulence factor produced by H. pylori was determined by sudden decrease in the current. The laboratory synthesized nano composites were characterised by Scanning Electron Microscopy (SEM) and Atomic force microscopy (AFM) studies. The sensor had excellent linear range of 0.1 ng/ml to 30 ng/ml by limiting the detection range up to 0.1 ng/ml. Moreover, the novel immunosensor formed had good accuracy, precision and reliability. The immunosensor also showed an excellent storage stability by retaining 60-70% of its initial activity until 60 days kept at 4 °C. Highly sensitive interface of CagA antigen@Ptnano/PEDOT/red-GOx/Au-ET shows a promising future for H. pylori detection in diagnosis of stomach ulcer and stomach cancer.


Assuntos
Anticorpos Antibacterianos , Antígenos de Bactérias , Proteínas de Bactérias , Compostos Bicíclicos Heterocíclicos com Pontes/química , Materiais Revestidos Biocompatíveis/química , Técnicas Eletroquímicas , Infecções por Helicobacter , Helicobacter pylori , Nanocompostos/química , Platina/química , Polímeros/química , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Eletrodos , Infecções por Helicobacter/sangue , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Helicobacter pylori/metabolismo , Humanos , Imunoensaio
19.
Microb Pathog ; 135: 103614, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31255726

RESUMO

Helicobacter pylori is an important etiological factor involved in chronic gastritis, peptic ulcer, and gastric cancer. There are currently no optimal preventive or therapeutic interventions for H. pylori infection. H. pylori survives in the stomach by sensing and adapting to the highly acidic environment by using the two-component signal transduction system that contains the most widely known gastric acid receptor, ArsRS (which is composed of ArsS and ArsR). This study aimed to identify peptides that antagonize the acid-sensing domain of H. pylori ArsS. These peptides could be used to block the acid-sensing signal and thereby hinder H. pylori adaption to acidic environments to prevent its survival. Using proSite, the functional domains (including the N-terminal acid-sensing domain) of H. pylori J99 ArsS were predicted. The purified recombinant ArsS N-terminal acid-sensing protein (P-ArsS-A) was used as the target in a panning protocol in which peptides from the Ph.D.-7 Phage Display Peptide Library that could bind to P-ArsS-A were identified. As a result, eight phage clones that could specifically bind to P-ArsS-A were obtained and five amino acid sequences were identified, including P03 (MMSYPKH) and P06 (LTPMPNW). An in vitro minimum inhibitory concentration (MIC) evaluation showed that P03 and P06 significantly inhibited the growth of H. pylori J99. The MIC of P03 was 8 µM, and the MIC of P06 was >16 µM, indicating that P03 is a stronger inhibitor compared to P06. This was confirmed by colony counting on blood agar plates after P03 and P06 administration. Using homology modeling and molecular docking analysis, it was shown that P03 and P06 could bind to the ArsS N-terminal domain, and there were four shared binding sites: TYR25, ASN39, ARG73, and GLU74. Additionally, one hydrogen bond was found between P03 and ArsS, which is more cohesive than other forms of bonding (van der Waals force, other non-covalent bonds).


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófagos/fisiologia , Helicobacter pylori/metabolismo , Biblioteca de Peptídeos , Peptídeos/isolamento & purificação , Ácidos , Proteínas de Bactérias/genética , Sítios de Ligação , Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Peptídeos/imunologia , Proteínas Recombinantes , Transdução de Sinais/fisiologia
20.
Med Sci Monit ; 25: 4837-4848, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31256192

RESUMO

BACKGROUND Helicobacter pylori infection is associated with various vascular diseases. However, its mechanism is yet to be defined. The present study aimed to investigate the effect of H. pylori on vascular endothelial cells as well as the GATA3-related mechanism of H. pylori infection-induced endothelial injuries. MATERIAL AND METHODS A co-culture of H. pylori with human umbilical endothelial cells (HUVECs) was produced. The proliferation of HUVECs that had been incubated with H. pylori were examined via CCK-8 (Cell Counting Kit-8) and EdU (5-ethynyl-2'-deoxyuridine) staining. Cell migration and microtubules formation were studied using Transwell and tube formation respectively. Construction of a mouse model of H. pylori infection as well as the expression of GATA3 and CHI3L1 in vessels were tested using western blot and immunohistochemistry. Small interfering RNA (siRNA) of GATA3 were transfected into HUVECs in order to establish cell lines with knocked-down GATA3. The production of the aforementioned molecules and p38 mitogen-activated protein kinase (MAPK) related molecules in HUVECs was measured using quantitative real-time polymerase chain reaction and western blot. RESULTS H. pylori significantly inhibited the proliferation, migration, and tube formation of HUVECs, as well as increased the production of the inflammatory factor CHI3L1 and phosphorylated p38 from endothelial cells along with an increased expression of GATA3. Elevated levels of the GATA3 and CHI3L1 were also found in the arteries of H. pylori-infected mice. Following GATA3 knockdown, the H. pylori-induced dysfunction of HUVECs was restored. CONCLUSIONS H. pylori impaired vascular endothelial function. This might be due to the H. pylori-induced increased expression of GATA3, as well as the GATA3 mediated upregulated CHI3L1 and activation of the p38 MAPK pathway.


Assuntos
Proteína 1 Semelhante à Quitinase-3/biossíntese , Células Endoteliais/microbiologia , Fator de Transcrição GATA3/metabolismo , Infecções por Helicobacter/patologia , Helicobacter pylori/metabolismo , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Proteína 1 Semelhante à Quitinase-3/metabolismo , Quitinases/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Fator de Transcrição GATA3/biossíntese , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , RNA Interferente Pequeno/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
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