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1.
FASEB J ; 35(11): e21942, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34670018

RESUMO

Atherosclerosis is a chronic inflammatory disease. Pathophysiological similarities between chronic infections and atherosclerosis triggered interests between these conditions. The seroepidemiological study showed that Helicobacter pylori strains that express cytotoxin-associated gene A (CagA), an oncoprotein and a major virulence factor, was positively correlated with atherosclerosis and related clinical events. Nevertheless, the underlying mechanism is poorly understood. In this study, the seroprevalence of infection by H. pylori and by strains express CagA assessed by enzyme-linked immunosorbent assay (ELISA) showed that the prevalence of CagA strains rather than H. pylori in patients was positively correlated with atherogenesis. Correspondingly, we found that CagA augmented the growth of plaque of ApoE-/- mice in the early stage of atherosclerosis and promoted the expression of adhesion molecules and inflammatory cytokines in mouse aortic endothelial cells (MAECs). Mechanistically, both si-NLRP3 and si-IL-1ß mitigated the promoting effect of CagA on the inflammatory activation of HAECs. In vivo, the inhibition of NLRP3 by MCC950 significantly attenuated the promoting effect of CagA on plaque growth of ApoE-/- mice. We also propose NLRP3 as a potential therapeutic target for CagA-positive H. pylori infection-related atherosclerosis and emphasize the importance of inflammation in atherosclerosis pathology.


Assuntos
Antígenos de Bactérias/metabolismo , Aorta/patologia , Aterosclerose/sangue , Proteínas de Bactérias/metabolismo , Caspase 1/metabolismo , Células Endoteliais/metabolismo , Infecções por Helicobacter/sangue , Helicobacter pylori/metabolismo , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Placa Aterosclerótica/sangue , Idoso , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Aorta/metabolismo , Aterosclerose/microbiologia , Proteínas de Bactérias/imunologia , Modelos Animais de Doenças , Feminino , Infecções por Helicobacter/imunologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/imunologia , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Pessoa de Meia-Idade , Placa Aterosclerótica/microbiologia , Estudos Soroepidemiológicos , Células THP-1
2.
Helicobacter ; 26(6): e12849, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34490965

RESUMO

BACKGROUND: Activin A receptor type I (ACVR1) is involved in tumorigenesis. However, the underlying molecular mechanisms of ACVR1 in gastric cancer (GC) and its association with Helicobacter pylori remained unclear. MATERIALS AND METHODS: The Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis (GEPIA) database were utilized to explore the ACVR1 expression in GC and normal control and its association with survival. The ACVR1 was knocked out using CRISPR/Cas-9; RNA sequencing analysis was performed in AGS cells with ACVR1 knockout and normal control. Functional experiments (CCK-8, colony-forming, and transwell assays) were conducted to demonstrate the role of ACVR1 in cell proliferation, invasion, and metastasis. H. pylori-infected C57/BL6 models were established. ACVR1, p-Smad1/5, and CDX2 were detected in AGS cells cocultured with H. pylori strains. The CDX2 and key elements of BMP signaling pathway were detected in AGS cells with ACVR1 knockout and normal control. In addition, Immunohistochemistry was performed to detect the ACVR1 and CDX2 expression in gastric samples. RESULTS: ACVR1 expression was higher in GC than normal control from TCGA, GEPIA, and samples collected from our hospital (p < 0.05). ACVR1 promoted cell proliferation, migration, and invasion in vitro. Both cagA+ and cagA- H. pylori could upregulate the expression ACVR1 (p < 0.05). Downregulation of ACVR1 inhibited the H. pylori-induced cell proliferation, migration, and invasion (p < 0.05). H. pylori increased the expression of p-Smad 1/5 and CDX2. The CDX2 and key elements of BMP signaling pathway were downregulated in AGS cells with ACVR1 knockout. ACVR1 and CDX2 were upregulated in the stage of intestinal metaplasia (IM). Moreover, ACVR1 and CDX2 expressions were higher in H. pylori-positive group than H. pylori-negative group (p < 0.05). CONCLUSION: Our data indicate that H. pylori infection increases ACVR1 expression, promoting gastric IM via regulating CDX2, which is an essential step in H. pylori carcinogenesis.


Assuntos
Receptores de Ativinas Tipo I , Fator de Transcrição CDX2 , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Ativinas , Animais , Fator de Transcrição CDX2/genética , Fator de Transcrição CDX2/metabolismo , Mucosa Gástrica/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Metaplasia , Camundongos , Camundongos Endogâmicos C57BL , Oncogenes , Neoplasias Gástricas/genética , Regulação para Cima
3.
Int J Mol Sci ; 22(17)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34502367

RESUMO

BACKGROUND: the neoplastic B cells of the Helicobacter pylori-related low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma proliferate in response to H. pylori, however, the nature of the H. pylori antigen responsible for proliferation is still unknown. The purpose of the study was to dissect whether CagY might be the H. pylori antigen able to drive B cell proliferation. METHODS: the B cells and the clonal progeny of T cells from the gastric mucosa of five patients with MALT lymphoma were compared with those of T cell clones obtained from five H. pylori-infected patients with chronic gastritis. The T cell clones were assessed for their specificity to H. pylori CagY, cytokine profile and helper function for B cell proliferation. RESULTS: 22 of 158 CD4+ (13.9%) gastric clones from MALT lymphoma and three of 179 CD4+ (1.7%) clones from chronic gastritis recognized CagY. CagY predominantly drives Interferon-gamma (IFN-γ) and Interleukin-17 (IL-17) secretion by gastric CD4+ T cells from H. pylori-infected patients with low-grade gastric MALT lymphoma. All MALT lymphoma-derived clones dose dependently increased their B cell help, whereas clones from chronic gastritis lost helper activity at T-to-B-cell ratios greater than 1. CONCLUSION: the results obtained indicate that CagY drives both B cell proliferation and T cell activation in gastric MALT lymphomas.


Assuntos
Helicobacter pylori/enzimologia , Linfoma de Zona Marginal Tipo Células B/imunologia , Linfoma de Zona Marginal Tipo Células B/microbiologia , Idoso , Linfócitos B/imunologia , Linfócitos B/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proliferação de Células , Feminino , Mucosa Gástrica/metabolismo , Gastrite/patologia , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/patologia , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Humanos , Inflamação/imunologia , Interferon gama/metabolismo , Ativação Linfocitária , Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Estômago/patologia , Células Th1/imunologia , Células Th1/metabolismo , Células Th17/imunologia , Células Th17/metabolismo
4.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360614

RESUMO

HP1043 is an essential orphan response regulator of Helicobacter pylori orchestrating multiple crucial cellular processes. Classified as a member of the OmpR/PhoB family of two-component systems, HP1043 exhibits a highly degenerate receiver domain and evolved to function independently of phosphorylation. Here, we investigated the HP1043 binding mode to a target sequence in the hp1227 promoter (Php1227). Scanning mutagenesis of HP1043 DNA-binding domain and consensus sequence led to the identification of residues relevant for the interaction of the protein with a target DNA. These determinants were used as restraints to guide a data-driven protein-DNA docking. Results suggested that, differently from most other response regulators of the same family, HP1043 binds in a head-to-head conformation to the Php1227 target promoter. HP1043 interacts with DNA largely through charged residues and contacts with both major and minor grooves of the DNA are required for a stable binding. Computational alanine scanning on molecular dynamics trajectory was performed to corroborate our findings. Additionally, in vitro transcription assays confirmed that HP1043 positively stimulates the activity of RNA polymerase.


Assuntos
Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Humanos , Simulação de Dinâmica Molecular , Fosforilação , Conformação Proteica , Fatores de Transcrição/química , Fatores de Transcrição/genética
5.
FEBS Lett ; 595(16): 2160-2168, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34216493

RESUMO

The persistence of Helicobacter pylori in the human gastric mucosa implies that the immune response fails to clear the infection. We found that H. pylori compromises the antigen presentation ability of macrophages, because of the decline of the presenting molecules HLA-II. Here, we reveal that the main bacterial factor responsible for this effect is ADP-heptose, an intermediate metabolite in the biosynthetic pathway of lipopolysaccharide (LPS) that elicits a pro-inflammatory response in gastric epithelial cells. In macrophages, it upregulates the expression of miR146b which, in turn, would downmodulate CIITA, the master regulator for HLA-II genes. Hence, H. pylori, utilizing ADP-heptose, exploits a specific arm of macrophage response to establish its survival niche in the face of the immune defense elicited in the gastric mucosa.


Assuntos
Apresentação do Antígeno/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Helicobacter pylori/fisiologia , Heptoses/farmacologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Macrófagos/efeitos dos fármacos , Helicobacter pylori/metabolismo , Heptoses/química , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Proteínas Nucleares/metabolismo , Transativadores/metabolismo
6.
Int J Mol Sci ; 22(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205762

RESUMO

oriC is a region of the bacterial chromosome at which the initiator protein DnaA interacts with specific sequences, leading to DNA unwinding and the initiation of chromosome replication. The general architecture of oriCs is universal; however, the structure of oriC and the mode of orisome assembly differ in distantly related bacteria. In this work, we characterized oriC of Helicobacter pylori, which consists of two DnaA box clusters and a DNA unwinding element (DUE); the latter can be subdivided into a GC-rich region, a DnaA-trio and an AT-rich region. We show that the DnaA-trio submodule is crucial for DNA unwinding, possibly because it enables proper DnaA oligomerization on ssDNA. However, we also observed the reverse effect: DNA unwinding, enabling subsequent DnaA-ssDNA oligomer formation-stabilized DnaA binding to box ts1. This suggests the interplay between DnaA binding to ssDNA and dsDNA upon DNA unwinding. Further investigation of the ts1 DnaA box revealed that this box, together with the newly identified c-ATP DnaA box in oriC1, constitute a new class of ATP-DnaA boxes. Indeed, in vitro ATP-DnaA unwinds H. pylori oriC more efficiently than ADP-DnaA. Our results expand the understanding of H. pylori orisome formation, indicating another regulatory pathway of H. pylori orisome assembly.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Helicobacter pylori/metabolismo , Complexo de Reconhecimento de Origem , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Helicobacter pylori/genética , Mutação
7.
Helicobacter ; 26(5): e12842, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34331360

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) is a major risk factor for gastric cancer. The water channel protein Aquaporin 5 (AQP5) is involved in the tumorigenesis and progression of various cancers. In this study, we aimed to explore the role of AQP5 in H. pylori-induced gastric carcinogenesis. MATERIALS AND METHODS: We collected 160 samples which inculded CNAG, IM, Dys and gastric cancer from patients who underwent endoscopy and detected the expression of AQP5. In vivo and vitro H. pylori infection models, we explored the relationship between AQP5 and H. pylori. Plasmid, siRNA and inhibitors were used to investigated the relationship between AQP5 and EMT and the role of AQP5 in H. pylori-induced gastric carcinogenesis. RESULT: AQP5 expression was gradually increased in human gastric tissues with the progression of chronic nonatrophic gastritis to gastric cancer and associated with the H. pylori infection status. In vivo and in vitro studies showed that H. pylori infection induced AQP5 expression in gastric epithelial cells in a CagA-dependent manner. Knockdown of AQP5 reversed H. pylori-induced cell proliferation and invasion, and -suppressed cell apoptosis. Additionally, knockdown of AQP5 suppressed H. pylori-induced Epithelial-mesenchymal transition (EMT) phenotypes by regulating transcriptional factors, mesenchymal markers, and epithelial markers. CONCLUSIONS: We explored the underlying mechanism and our results indicated that knockdown of AQP5 significantly suppressed H. pylori infection-induced phosphorylation of ERK1/2, MEK and the expression levels of downstream genes. Treatment with an ERK inhibitor suppressed the EMT induced by H. pylori infection. Taken together, this study suggest that pathogenic H. pylori infection promotes AQP5 expression to induce the EMT via the MEK/ERK signaling pathway.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Sistema de Sinalização das MAP Quinases , Neoplasias Gástricas , Antígenos de Bactérias/metabolismo , Aquaporina 5/genética , Proteínas de Bactérias/metabolismo , Carcinogênese , Carcinógenos , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Mucosa Gástrica/metabolismo , Helicobacter pylori/metabolismo , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno
8.
EMBO Rep ; 22(9): e52878, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34328245

RESUMO

Helicobacter pylori infection constitutes one of the major risk factors for the development of gastric diseases including gastric cancer. The activation of nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB) via classical and alternative pathways is a hallmark of H. pylori infection leading to inflammation in gastric epithelial cells. Tumor necrosis factor receptor-associated factor (TRAF)-interacting protein with forkhead-associated domain (TIFA) was previously suggested to trigger classical NF-κB activation, but its role in alternative NF-κB activation remains unexplored. Here, we identify TRAF6 and TRAF2 as binding partners of TIFA, contributing to the formation of TIFAsomes upon H. pylori infection. Importantly, the TIFA/TRAF6 interaction enables binding of TGFß-activated kinase 1 (TAK1), leading to the activation of classical NF-κB signaling, while the TIFA/TRAF2 interaction causes the transient displacement of cellular inhibitor of apoptosis 1 (cIAP1) from TRAF2, and proteasomal degradation of cIAP1, to facilitate the activation of the alternative NF-κB pathway. Our findings therefore establish a dual function of TIFA in the activation of classical and alternative NF-κB signaling in H. pylori-infected gastric epithelial cells.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Helicobacter pylori/metabolismo , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Fator 6 Associado a Receptor de TNF/genética , Fator 6 Associado a Receptor de TNF/metabolismo
9.
Nucleic Acids Res ; 49(12): 6863-6879, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34139017

RESUMO

Helicobacter pylori is a gram-negative, microaerophilic, pathogenic bacterium and a widespread colonizer of humans. H. pylori has developed mechanisms that enable it to overcome the harsh environment of the human stomach, including reactive oxygen species (ROS). Interestingly, up to now no typical regulator dedicated to the oxidative-stress response has been discovered. In this work, we reveal that the inhibitor of replication initiation HP1021 functions as a redox switch protein in H. pylori and plays an important role in response to oxidative stress of the gastric pathogen. Each of the two predicted HP1021 domains contains three cysteine residues. We show that the cysteine residues of HP1021 are sensitive to oxidation both in vitro and in vivo, and we demonstrate that HP1021 DNA-binding activity to oriC depends on the redox state of the protein. Moreover, Zn2+ modulates HP1021 affinity towards oriC template DNA. Transcription analysis of selected H. pylori genes by RT-qPCR indicated that HP1021 is directly involved in the oxygen-dependent control of H. pylori fecA3 and gluP genes, which are implicated in response to oxidative stress. In conclusion, HP1021 is a redox switch protein and could be a target for H. pylori control strategies.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Helicobacter pylori/genética , Estresse Oxidativo , Proteínas de Bactérias/química , Proteínas de Bactérias/fisiologia , Cátions Bivalentes/metabolismo , DNA/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/fisiologia , Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/metabolismo , Modelos Moleculares , Oxirredução , Ligação Proteica , Domínios Proteicos , Transcrição Genética
10.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070700

RESUMO

BACKGROUND: the molecular mechanism of gastric cancer development related to Helicobacter pylori (H. pylori) infection has not been fully understood, and further studies are still needed. Information regarding nanomechanical aspects of pathophysiological events that occur during H. pylori infection can be crucial in the development of new prevention, treatment, and diagnostic measures against clinical consequences associated with H. pylori infection, including gastric ulcer, duodenal ulcer, and gastric cancer. METHODS: in this study, we assessed mechanical properties of children's healthy and H. pylori positive stomach tissues and the mechanical response of human gastric cells exposed to heat-treated H. pylori cells using atomic force microscopy (AFM NanoWizard 4 BioScience JPK Instruments Bruker). Elastic modulus (i.e., the Young's modulus) was derived from the Hertz-Sneddon model applied to force-indentation curves. Human tissue samples were evaluated using rapid urease tests to identify H. pylori positive samples, and the presence of H. pylori cells in those samples was confirmed using immunohistopathological staining. RESULTS AND CONCLUSION: collected data suggest that nanomechanical properties of infected tissue might be considered as markers indicated H. pylori presence since infected tissues are softer than uninfected ones. At the cellular level, this mechanical response is at least partially mediated by cell cytoskeleton remodeling indicating that gastric cells are able to tune their mechanical properties when subjected to the presence of H. pylori products. Persistent fluctuations of tissue mechanical properties in response to H. pylori infection might, in the long-term, promote induction of cancer development.


Assuntos
Mucosa Gástrica , Infecções por Helicobacter , Helicobacter pylori/metabolismo , Úlcera Gástrica , Adolescente , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/patologia , Humanos , Masculino , Úlcera Gástrica/metabolismo , Úlcera Gástrica/microbiologia , Úlcera Gástrica/patologia
11.
Int J Mol Sci ; 22(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062919

RESUMO

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.


Assuntos
Vesículas Extracelulares/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Gastropatias/metabolismo , Membrana Externa Bacteriana/metabolismo , Progressão da Doença , Vesículas Extracelulares/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/patogenicidade , Humanos , Gastropatias/microbiologia , Gastropatias/patologia
12.
Front Immunol ; 12: 632154, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093525

RESUMO

The human gastric pathogen Helicobacter pylori activates human epithelial cells by a particular combination of mechanisms, including NOD1 and ALPK1-TIFA activation. These mechanisms are characterized by a strong participation of the bacterial cag pathogenicity island, which forms a type IV secretion system (CagT4SS) that enables the bacteria to transport proteins and diverse bacterial metabolites, including DNA, glycans, and cell wall components, into human host cells. Building on previous findings, we sought to determine the contribution of lipopolysaccharide inner core heptose metabolites (ADP-heptose) in the activation of human phagocytic cells by H. pylori. Using human monocyte/macrophage-like Thp-1 cells and human primary monocytes and macrophages, we were able to determine that a substantial part of early phagocytic cell activation, including NF-κB activation and IL-8 production, by live H. pylori is triggered by bacterial heptose metabolites. This effect was very pronounced in Thp-1 cells exposed to bacterial purified lysates or pure ADP-heptose, in the absence of other bacterial MAMPs, and was significantly reduced upon TIFA knock-down. Pure ADP-heptose on its own was able to strongly activate Thp-1 cells and human primary monocytes/macrophages. Comprehensive transcriptome analysis of Thp-1 cells co-incubated with live H. pylori or pure ADP-heptose confirmed a signature of ADP-heptose-dependent transcript activation in monocyte/macrophages. Bacterial enzyme-treated lysates (ETL) and pure ADP-heptose-dependent activation differentiated monocytes into macrophages of predominantly M1 type. In Thp-1 cells, the active CagT4SS was less required for the heptose-induced proinflammatory response than in epithelial cells, while active heptose biosynthesis or pure ADP-heptose was required and sufficient for their early innate response and NF-κB activation. The present data suggest that early activation and maturation of incoming and resident phagocytic cells (monocytes, macrophages) in the H. pylori-colonized stomach strongly depend on bacterial LPS inner core heptose metabolites, also with a significant contribution of an active CagT4SS.


Assuntos
Ilhas Genômicas/fisiologia , Helicobacter pylori/metabolismo , Heptoses/metabolismo , Macrófagos/imunologia , Monócitos/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Vias Biossintéticas , Helicobacter pylori/patogenicidade , Humanos , Imunidade Inata , Lipopolissacarídeos/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Monócitos/metabolismo , Transdução de Sinais , Transcriptoma , Sistemas de Secreção Tipo IV/genética , Sistemas de Secreção Tipo IV/metabolismo
13.
J Cancer Res Clin Oncol ; 147(10): 2851-2865, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34117917

RESUMO

PURPOSE: As the conventional therapeutic approaches were not completely successful in the treatment of colon cancer, there is still a need for finding the most efficient therapeutic agents. Here we investigated the anticancer activity of HPRP-A1 that was derived from the N-terminal region of Helicobacter pylori ribosomal protein L1 (RpL1) alone or in combination with tumor-homing peptide iRGD and 5-Fluorouracil (5FU) on colon cancer cell lines (CT26 and HT29) and isograft models of colon cancer. METHOD: We assessed the tumor growth inhibitory activity of HPRP-A1 with or without iRGD and 5FU on colon cancer in vitro and in vivo. In the in vitro part, we investigate the effect of HPRP-A1 alone and in combination with iRGD/5FU. RESULTS: Our results demonstrated that co-administration of HPRP-A1 with iRGD increased the apoptosis, while these two peptides in combination with 5FU increased the intracellular level of p53 that upregulate the pro-apoptotic gene BAX and downregulate the anti-apoptotic gene BCL2. HPRP-A1 blocks the cell cycle progression in G0/G1. Co-administration of two peptides significantly reduced the size and weight of the tumors, while the group that received 5FU in combination with the peptides increased the necrotic and decrease the fibrotic area significantly in the tumor tissues, which also disrupt the oxidant/antioxidant balance. CONCLUSIONS: Our results indicated that HPRP-A1 could be considered an effective agent toward colon cancer in vitro and in vivo with the ability to enhance the effects of conventional chemotherapy agent 5FU.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Proteínas de Bactérias/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Fluoruracila/farmacologia , Oligopeptídeos/farmacologia , Proteínas Ribossômicas/administração & dosagem , Animais , Apoptose , Proteínas de Bactérias/metabolismo , Movimento Celular , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Quimioterapia Combinada , Feminino , Helicobacter pylori/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Ribossômicas/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Biochemistry ; 60(24): 1933-1946, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34077175

RESUMO

Helicobacter pylori is a Gram-negative bacterium that is responsible for gastric and duodenal ulcers. H. pylori uses the unusual mqn pathway with aminofutalosine (AFL) as an intermediate for menaquinone biosynthesis. Previous reports indicate that hydrolysis of AFL by 5'-methylthioadenosine nucleosidase (HpMTAN) is the direct path for producing downstream metabolites in the mqn pathway. However, genomic analysis indicates jhp0252 is a candidate for encoding AFL deaminase (AFLDA), an activity for deaminating aminofutolasine. The product, futalosine, is not a known substrate for bacterial MTANs. Recombinant jhp0252 was expressed and characterized as an AFL deaminase (HpAFLDA). Its catalytic specificity includes AFL, 5'-methylthioadenosine, 5'-deoxyadenosine, adenosine, and S-adenosylhomocysteine. The kcat/Km value for AFL is 6.8 × 104 M-1 s-1, 26-fold greater than that for adenosine. 5'-Methylthiocoformycin (MTCF) is a slow-onset inhibitor for HpAFLDA and demonstrated inhibitory effects on H. pylori growth. Supplementation with futalosine partially restored H. pylori growth under MTCF treatment, suggesting AFL deamination is significant for cell growth. The crystal structures of apo-HpAFLDA and with MTCF at the catalytic sites show a catalytic site Zn2+ or Fe2+ as the water-activating group. With bound MTCF, the metal ion is 2.0 Å from the sp3 hydroxyl group of the transition state analogue. Metabolomics analysis revealed that HpAFLDA has intracellular activity and is inhibited by MTCF. The mqn pathway in H. pylori bifurcates at aminofutalosine with HpMTAN producing adenine and depurinated futalosine and HpAFLDA producing futalosine. Inhibition of cellular HpMTAN or HpAFLDA decreased the cellular content of menaquinone-6, supporting roles for both enzymes in the pathway.


Assuntos
Helicobacter pylori/metabolismo , Nucleosídeos/metabolismo , Vitamina K 2/metabolismo , Domínio Catalítico , Cristalografia por Raios X/métodos , Desoxiadenosinas , Helicobacter pylori/química , Helicobacter pylori/enzimologia , Modelos Moleculares , N-Glicosil Hidrolases/química , N-Glicosil Hidrolases/metabolismo , Nucleosídeos/química , Purina-Núcleosídeo Fosforilase/química , Especificidade por Substrato , Tionucleosídeos , Vitamina K 2/análogos & derivados
15.
J Microbiol ; 59(8): 763-770, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34061339

RESUMO

Helicobacter pylori colonizes human gastric mucosa. Its infection is associated with gastric diseases including gastric cancer. CagA is one of the most important toxins produced by H. pylori. It is related to gastric cancer which can be injected into host cells via a type IV secretion system (T4SS). CagL is a structural component of T4SS apparatus, which triggers host cell signaling pathway. It has been reported that CagL polymorphisms may influence the severity of disease development. To explore the contribution of CagL polymorphisms between East Asian and Western H. pylori in pathogenesis, cagL gene in G27 H. pylori was swapped by K74 cagL which is identical to East Asian CagL consensus sequence and by Western 26695 H. pylori, resulting in G27 ΔcagL/cagLK74 and G27 ΔcagL/cagL26695, respectively. Intriguingly, G27 ΔcagL/cagLK74 showed significantly less ability of IL-8 induction than G27 ΔcagL/cagL26695 while displayed similar abilities of CagA phosphorylation, and cell elongation. Taken together, this study suggests that the CagL polymorphism may influence IL-8 induction, and K74 CagL has less ability to induce IL-8 secretion than G27 or 26695 CagL. Further research should address how the different capabilities of IL-8 induction between intraspecies-CagL are associated with the large differences of the incidence of gastric cancer between East Asian and Western countries.


Assuntos
Proteínas de Bactérias/genética , Infecções por Helicobacter/metabolismo , Helicobacter pylori/genética , Interleucina-8/metabolismo , Polimorfismo Genético , Sequência de Aminoácidos , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/química , Helicobacter pylori/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Interleucina-8/genética , República da Coreia , Alinhamento de Sequência
16.
Medicine (Baltimore) ; 100(18): e25729, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33950955

RESUMO

BACKGROUND: There were many case-control studies performed the association between TLRs gene polymorphisms and the correlation of Helicobactor pylori infection, these results were inconformity. Therefore, a comprehensive meta-analysis was performed to evaluate the TLRs gene polymorphism and susceptibility to H. pylori infection. METHODS: Eligible studies were searched from PubMed, EMBASE, Web of science, Cochrane library, CNKI, CBM, Wan Fang Database and VIP Database, all the databases were searched from inception to December 2020. OR with the corresponding 95% CI were presented as associations between certain TLR gene polymorphism and the risk of H. pylori infection, all the included data will be analyzed with the software of Review Manager 5.2 and STATA 14.2. RESULTS: This study will provide a high-quality evidence to find the TLR gene polymorphisms with H. pylori infection susceptibility. CONCLUSION: This study will explore which TLR genotype increase the risk of H. pylori infection.


Assuntos
Predisposição Genética para Doença , Infecções por Helicobacter/epidemiologia , Receptores Toll-Like/genética , Estudos de Casos e Controles , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/genética , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/metabolismo , Humanos , Metanálise como Assunto , Padrões Moleculares Associados a Patógenos/metabolismo , Polimorfismo de Nucleotídeo Único , Revisões Sistemáticas como Assunto , Receptores Toll-Like/metabolismo
18.
Sci Rep ; 11(1): 10794, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031459

RESUMO

Iron-sulfur (Fe-S) proteins play essential roles in all living organisms. The gastric pathogen Helicobacter pylori relies exclusively on the NIF system for biosynthesis and delivery of Fe-S clusters. Previously characterized components include two essential proteins, NifS (cysteine desulfurase) and NifU (scaffold protein), and a dispensable Fe-S carrier, Nfu. Among 38 proteins previously predicted to coordinate Fe-S clusters, two proteins, HP0207 (a member of the Nbp35/ApbC ATPase family) and HP0277 (previously annotated as FdxA, a member of the YfhL ferredoxin-like family) were further studied, using a bacterial two-hybrid system approach to identify protein-protein interactions. ApbC was found to interact with 30 proteins, including itself, NifS, NifU, Nfu and FdxA, and alteration of the conserved ATPase motif in ApbC resulted in a significant (50%) decrease in the number of protein interactions, suggesting the ATpase activity is needed for some ApbC-target protein interactions. FdxA was shown to interact with 21 proteins, including itself, NifS, ApbC and Nfu, however no interactions between NifU and FdxA were detected. By use of cross-linking studies, a 51-kDa ApbC-Nfu heterodimer complex was identified. Attempts to generate apbC chromosomal deletion mutants in H. pylori were unsuccessful, therefore indirectly suggesting the hp0207 gene is essential. In contrast, mutants in the fdxA gene were obtained, albeit only in one parental strain (26695). Taken together, these results suggest both ApbC and FdxA are important players in the H. pylori NIF maturation system.


Assuntos
Helicobacter pylori/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Proteínas de Bactérias/metabolismo , Fixação de Nitrogênio , Mapas de Interação de Proteínas , Técnicas do Sistema de Duplo-Híbrido
19.
Cell Host Microbe ; 29(6): 941-958.e10, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-33989515

RESUMO

Infection with CagA-producing Helicobacter pylori plays a causative role in the development of gastric cancer. Upon delivery into gastric epithelial cells, CagA deregulates prooncogenic phosphatase SHP2 while inhibiting polarity-regulating kinase PAR1b through complex formation. Here, we show that CagA/PAR1b interaction subverts nuclear translocation of BRCA1 by inhibiting PAR1b-mediated BRCA1 phosphorylation. It hereby induces BRCAness that promotes DNA double-strand breaks (DSBs) while disabling error-free homologous recombination-mediated DNA repair. The CagA/PAR1b interaction also stimulates Hippo signaling that circumvents apoptosis of DNA-damaged cells, giving cells time to repair DSBs through error-prone mechanisms. The DSB-activated p53-p21Cip1 axis inhibits proliferation of CagA-delivered cells, but the inhibition can be overcome by p53 inactivation. Indeed, sequential pulses of CagA in TP53-mutant cells drove somatic mutation with BRCAness-associated genetic signatures. Expansion of CagA-delivered cells with BRCAness-mediated genome instability, from which CagA-independent cancer-predisposing cells arise, provides a plausible "hit-and-run mechanism" of H. pylori CagA for gastric carcinogenesis.


Assuntos
Antígenos de Bactérias/metabolismo , Proteína BRCA1/metabolismo , Proteínas de Bactérias/metabolismo , Células Epiteliais/metabolismo , Instabilidade Genômica , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carcinogênese/metabolismo , Linhagem Celular , Quebras de DNA de Cadeia Dupla , Células Epiteliais/microbiologia , Feminino , Regulação Neoplásica da Expressão Gênica , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Estômago/microbiologia , Proteína Supressora de Tumor p53/metabolismo
20.
Toxins (Basel) ; 13(3)2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33804551

RESUMO

The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Neoplasias Gástricas/microbiologia , Animais , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Transição Epitelial-Mesenquimal , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/terapia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Proteínas Imediatamente Precoces/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Risco , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/prevenção & controle , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Supressoras de Tumor/metabolismo
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