scholarly journals Cortactin: A Major Cellular Target of the Gastric Carcinogen Helicobacter pylori

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 159 ◽  
Author(s):  
Irshad Sharafutdinov ◽  
Steffen Backert ◽  
Nicole Tegtmeyer
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Cell Movement ◽  
Cell Types ◽  
Eukaryotic Cell ◽  
Actin Binding ◽  
Gastric Diseases ◽  
Cell Functions ◽  
H Pylori ◽  
Cytoskeletal Rearrangements

Cortactin is an actin binding protein and actin nucleation promoting factor regulating cytoskeletal rearrangements in nearly all eukaryotic cell types. From this perspective, cortactin poses an attractive target for pathogens to manipulate a given host cell to their own benefit. One of the pathogens following this strategy is Helicobacter pylori, which can cause a variety of gastric diseases and has been shown to be the major risk factor for the onset of gastric cancer. During infection of gastric epithelial cells, H. pylori hijacks the cellular kinase signaling pathways, leading to the disruption of key cell functions. Specifically, by overruling the phosphorylation status of cortactin, H. pylori alternates the activity of molecular interaction partners of this important protein, thereby manipulating the performance of actin-cytoskeletal rearrangements and cell movement. In addition, H. pylori utilizes a unique mechanism to activate focal adhesion kinase, which subsequently prevents host epithelial cells from extensive lifting from the extracellular matrix in order to achieve chronic infection in the human stomach.

scholarly journals Cortactin Promotes Effective AGS Cell Scattering by Helicobacter pylori CagA, but Not Cellular Vacuolization and Apoptosis Induced by the Vacuolating Cytotoxin VacA

Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Irshad Sharafutdinov ◽  
Jakob Knorr ◽  
Delara Soltan Esmaeili ◽  
Steffen Backert ◽  
Nicole Tegtmeyer
Keyword(s):  
Helicobacter Pylori ◽  
Cell Movement ◽  
Actin Binding ◽  
Knockout Mutant ◽  
Vacuolating Cytotoxin ◽  
Cell Functions ◽  
Cell Scattering ◽  
Induction Of Apoptosis ◽  
H Pylori ◽  
Cytoskeletal Rearrangements

Cortactin is an actin-binding protein and actin-nucleation promoting factor regulating cytoskeletal rearrangements in eukaryotes. Helicobacter pylori is a gastric pathogen that exploits cortactin to its own benefit. During infection of gastric epithelial cells, H. pylori hijacks multiple cellular signaling pathways, leading to the disruption of key cell functions. Two bacterial virulence factors play important roles in this scenario, the vacuolating cytotoxin VacA and the translocated effector protein CagA of the cag type IV secretion system (T4SS). Specifically, by overruling the phosphorylation status of cortactin, H. pylori alternates the activity of molecular interaction partners of this important protein, thereby manipulating the performance of cytoskeletal rearrangements, endosomal trafficking and cell movement. Based on shRNA knockdown and other studies, it was previously reported that VacA utilizes cortactin for its cellular uptake, intracellular travel and induction of apoptosis by a mitochondria-dependent mechanism, while CagA induces cell scattering, motility and elongation. To investigate the role of cortactin in these phenotypes in more detail, we produced a complete knockout mutant of cortactin in the gastric adenocarcinoma cell line AGS by CRISPR-Cas9. These cells were infected with H. pylori wild-type or various isogenic mutant strains. Unexpectedly, cortactin deficiency did not prevent the uptake and formation of VacA-dependent vacuoles, nor the induction of apoptosis by internalized VacA, while the induction of T4SS- and CagA-dependent AGS cell movement and elongation were strongly reduced. Thus, we provide evidence that cortactin is required for the function of internalized CagA, but not VacA.

scholarly journals α-Lipoic Acid Inhibits IL-8 Expression by Activating Nrf2 Signaling in Helicobacter pylori-infected Gastric Epithelial Cells

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2524 ◽  
Author(s):  
Seoyeon Kyung ◽  
Joo Weon Lim ◽  
Hyeyoung Kim
Keyword(s):  
Oxidative Stress ◽  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Lipoic Acid ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Gastric Epithelial Cells ◽  
Gastric Diseases ◽  
Ags Cells ◽  
H Pylori

Helicobacter pylori (H. pylori) causes gastritis and gastric cancers. Oxidative stress is involved in the pathological mechanism of H. pylori-induced gastritis and gastric cancer induction. Therefore, reducing oxidative stress may be beneficial for preventing the development of H. pylori-associated gastric diseases. Nuclear factor erythroid-2-related factor 2 (Nrf2) is a crucial regulator for the expression of antioxidant enzyme heme oxygenase-1 (HO-1), which protects cells from oxidative injury. α-Lipoic acid (α-LA), a naturally occurring dithiol, shows antioxidant and anti-inflammatory effects in various cells. In the present study, we examined the mechanism by which α-LA activates the Nrf2/HO-1 pathway, suppresses the production of pro-inflammatory cytokine interleukine-8 (IL-8), and reduces reactive oxygen species (ROS) in H. pylori-infected AGS cells. α-LA increased the level of phosphorylated and nuclear-translocated Nrf2 by decreasing the amount of Nrf2 sequestered in the cytoplasm by complex formation with Kelch-like ECH1-associated protein 1 (KEAP 1). By using exogenous inhibitors targeting Nrf2 and HO-1, we showed that up-regulation of activated Nrf2 and of HO-1 results in the α-LA-induced suppression of interleukin 8 (IL-8) and ROS. Consumption of α-LA-rich foods may prevent the development of H. pylori-associated gastric diseases by decreasing ROS-mediated IL-8 expression in gastric epithelial cells.

scholarly journals Helicobacter pylori Exploits Cholesterol-Rich Microdomains for Induction of NF-κB-Dependent Responses and Peptidoglycan Delivery in Epithelial Cells

2010 ◽  
Vol 78 (11) ◽  
pp. 4523-4531 ◽  
Author(s):  
Melanie L. Hutton ◽  
Maria Kaparakis-Liaskos ◽  
Lorinda Turner ◽  
Ana Cardona ◽  
Terry Kwok ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Host Cell ◽  
Severe Disease ◽  
Host Cells ◽  
Type Iv ◽  
Increased Risk ◽  
Proinflammatory Responses ◽  
H Pylori ◽  
Cytoskeletal Rearrangements

ABSTRACT Infection with Helicobacter pylori cag pathogenicity island (cagPAI)-positive strains is associated with more destructive tissue damage and an increased risk of severe disease. The cagPAI encodes a type IV secretion system (TFSS) that delivers the bacterial effector molecules CagA and peptidoglycan into the host cell cytoplasm, thereby inducing responses in host cells. It was previously shown that interactions between CagL, present on the TFSS pilus, and host α5β1 integrin molecules were critical for CagA translocation and the induction of cytoskeletal rearrangements in epithelial cells. As the α5β1 integrin is found in cholesterol-rich microdomains (known as lipid rafts), we hypothesized that these domains may also be involved in the induction of proinflammatory responses mediated by NOD1 recognition of H. pylori peptidoglycan. Indeed, not only did methyl-β-cyclodextrin depletion of cholesterol from cultured epithelial cells have a significant effect on the levels of NF-κB and interleukin-8 (IL-8) responses induced by H. pylori bacteria with an intact TFSS (P < 0.05), but it also interfered with TFSS-mediated peptidoglycan delivery to cells. Both of these effects could be restored by cholesterol replenishment of the cells. Furthermore, we demonstrated for the first time the involvement of α5β1 integrin in the induction of proinflammatory responses by H. pylori. Taking the results together, we propose that α5β1 integrin, which is associated with cholesterol-rich microdomains at the host cell surface, is required for NOD1 recognition of peptidoglycan and subsequent induction of NF-κB-dependent responses to H. pylori. These data implicate cholesterol-rich microdomains as a novel platform for TFSS-dependent delivery of bacterial products to cytosolic pathogen recognition molecules.

scholarly journals Interaction of CagA with Crk plays an important role in Helicobacter pylori–induced loss of gastric epithelial cell adhesion

2005 ◽  
Vol 202 (9) ◽  
pp. 1235-1247 ◽  
Author(s):  
Masato Suzuki ◽  
Hitomi Mimuro ◽  
Toshihiko Suzuki ◽  
Morag Park ◽  
Tadashi Yamamoto ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Adaptor Proteins ◽  
Dominant Negative ◽  
Gastric Epithelium ◽  
Host Responses ◽  
Gastric Epithelial Cells ◽  
Gastric Diseases ◽  
Cell Responses ◽  
H Pylori

CagA protein is a major virulence factor of Helicobacter pylori, which is delivered into gastric epithelial cells and elicits growth factor–like responses. Once within the cells, CagA is tyrosine phosphorylated by Src family kinases and targets host proteins required to induce the cell responses. We show that the phosphorylated CagA binds Crk adaptor proteins (Crk-II, Crk-I, and Crk-L) and that the interaction is important for the CagA-mediated host responses during H. pylori infection. H. pylori–induced scattering of gastric epithelial cells in culture was blocked by overexpression of dominant-negative Crk and by RNA interference–mediated knockdown of endogenous Crk. H. pylori infection of the gastric epithelium induced disruption of E-cadherin/catenin–containing adherens junctions, which was also dependent on CagA/Crk signaling. Furthermore, inhibition of the SoS1/H-Ras/Raf1, C3G/Rap1/B-Raf, or Dock180/Rac1/Wiskott-Aldrich syndrome protein family verprolin homologous protein pathway, all of which are involved downstream of Crk adaptors, greatly diminished the CagA-associated host responses. Thus, CagA targeting of Crk plays a central role in inducing the pleiotropic cell responses to H. pylori infection that cause several gastric diseases, including gastric cancer.

Helicobacter pylori CagA induces ornithine decarboxylase upregulation via Src/MEK/ERK/c-Myc pathway: implication for progression of gastric diseases

2012 ◽  
Vol 237 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Xia Xu ◽  
Zhifang Liu ◽  
Ming Fang ◽  
Han Yu ◽  
Xiuming Liang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Ornithine Decarboxylase ◽  
Ectopic Expression ◽  
Negative Control ◽  
Mitogen Activated Protein Kinase ◽  
Gastric Epithelial Cells ◽  
Gastric Diseases ◽  
Key Enzyme ◽  
H Pylori

Helicobacter pylori (H. pylori) dysregulates the expression of various genes resulting in gastric precursor lesions and cancer. Meanwhile, ornithine decarboxylase (ODC) is a key enzyme that catalyzes the formation of polyamines which are critical for cell growth. So far, the possible regulation of ODC by H. pylori and its virulence factors, and the associated mechanism in gastric epithelial cells remains undefined. In the present study, we found that cellular ODC protein was upregulated by wild-type H. pylori infection and ectopic expression of a cytotoxin-associated gene A (CagA). As a negative control, there was no such effect by cagA-mutant H. pylori infection. Results of signal protein inhibitor treatment demonstrated that the Src, MEK (mitogen-activated protein kinase kinase) and ERK (extracellular signal-regulated kinase) pathway was involved. Moreover, when c-Myc was inhibited, the stimulatory effect of CagA on ODC expression was abolished. Clinically, a positive correlation between c-Myc and ODC expression was observed in patient-derived abnormal gastric tissues. These results implied that the Src/MEK/ERK/c-Myc pathway was required for CagA-mediated ODC induction. Finally, inhibition of ODC expression led to decreased foci formation of gastric epithelial cells before and after H. pylori infection, and ODC protein was over-expressed in precancerous gastric lesions and primary gastric cancer. Collectively, our findings provide new insights into the mechanism behind H. pylori-infection-associated gastric diseases.

Analysis of babA, cagE and cagA Genes in Helicobacter pylori from Upper Gastric Patients in the North of Iran

2019 ◽  
Vol 19 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Saba Fakhrieh Asl ◽  
Mehrnaz Pourvahedi ◽  
Ali Mojtahedi ◽  
Mohammad Shenagari
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Diseases ◽  
Specific Primers ◽  
The North ◽  
Different Types ◽  
North Of Iran ◽  
Gastric Biopsies ◽  
Pcr Method ◽  
Non Ulcer Dyspepsia ◽  
H Pylori

Objective:Helicobacter pylori is a Gram-negative bacterium which has a serious effect on up to half of the world’s population and has been related to different gastric diseases. The goal of this study was to assess the frequency of babA, cagE and cagA genotypes among H. pylori strains isolated from gastric biopsies of endoscopic patients in the north of Iran.Methods:The present study was performed on 90 strains of H. pylori isolated from patients with gastric diseases (Gastric ulcer (GU), Duodenal ulcer (DU), Gastritis (G), Non-ulcer dyspepsia (NUD) and Gastric adenocarcinoma (GC)). DNA was extracted from all isolated strains and PCR method was performed to detect the prevalence of babA2, cagE and cagA genes using specific primers.Results:Among 90 samples of H. pylori, babA2, cagE, and cagA genes were detected in 42.2%, 30% and 82.2% of strains respectively. The statistical analysis showed that the prevalence of cagA gene in GU, G, DU, and NUD was significantly higher than other genes. Moreover, cagA, and babA2 genes were significantly more prevalent in GC patients compared to cagE gene. Our isolates exhibited 8 distinct arrangements of virulence patterns. The occurrence of cagA (35.6%) was the most prevalent pattern followed by cagA/babA2 (20%) and cagA/babA2/cagE (14.4%).Conclusion:In summary, as first report from Guilan province in the north of Iran, we showed significant association between the presence of babA2, cagE, and cagA genes in different types of gastric disorders.

Perfil Epidemiológico de Pacientes Submetidos à Biópsia Gástrica em um Hospital Escola do Sul de Minas Gerais/ Epidemiological Profile of Patients Undergo Gastric Biopsy in a School Hospital of Minas Gerais

1970 ◽  
Vol 4 (3) ◽  
pp. 48-57
Author(s):  
Isabela Maria A. Ribeiro Simões ◽  
Ana Carolina Mauad Coli ◽  
Roseane de Souza Candido Irulegui
Keyword(s):  
Helicobacter Pylori ◽  
Age Groups ◽  
Epidemiological Data ◽  
Minas Gerais ◽  
Gastric Biopsy ◽  
Gastric Ulcers ◽  
Histopathological Diagnosis ◽  
Gastric Diseases ◽  
H Pylori ◽  
Epidemiological Profile

Objetivo: Determinar a prevalência de lesões benignas e neoplasia gástrica através do estudo de biópsias realizadas em um Hospital Escola do Sul de Minas Gerais, no período entre 2007 e 2011. Materiais e Métodos: A pesquisa documental foi quantitativa e retrospectiva, baseada na análise dos registros de biópsias e prontuários. Realizou-se o levantamento de dados referentes à idade, gênero, cor, profissão, diagnóstico histopatológico e presença de Helicobacter pylori nas amostras. Resultados: O número total de biópsias gástricas analisadas foi de 1225, cujo perfil populacional encontrado foi: idade média de 56,75 anos, sexo masculino (52%), cor branca (81,9 %), aposentado (30%). Os diagnósticos mais frequentes foram: gastrites (71,9%), pólipos (14,2%), adenocarcinomas (5,9%), úlceras gástricas (6%), linfomas (0,4%), sem alterações (0,4%) e outros (1,2%). Em outros, encontram-se achados de malignidade, metaplasia e xantelasma gástrico. Em relação à presença de Helicobacter pylori nas amostras, o resultado encontrado foi de24% positivas, 46% negativas e 30% não pesquisadas. Conclusão: Os resultados confirmam a alta frequência das doenças gástricas e sua incidência nas diversas faixas etárias, além do envolvimento do H. pylori em tais afecções. É de grande importância a caracterização dos dados epidemiológicos, o que permite prováveis direcionamentos para programas de prevenção e informação para a população. Palavras-chave: biópsia gástrica, gastropatia, perfil epidemiológico.  ABSTRACTObjective: To determine the prevalence of benign lesions and gastric cancer through study of biopsies performed at a school hospital in southern Minas Gerais, in the period between 2007 and 2011.Materials and Methods: The research was quantitative and retrospective, based on analysis of biopsies records and medical records. We conducted the survey data regarding age, sex, color, profession, histopathological diagnosis and the presence of Helicobacter pylori in the samples. Results: The total number of gastric biopsies analyzed was 1225. Population listing was found: mean age of 56.75 years, male (52%), white (81.9%), retired (30%). The most frequent diagnoses were gastritis (71.9%), polyps (14.2%), adenocarcinomas (5.9%), gastric ulcers (6%), lymphoma (0.4%), unchanged (0, 4%) and others (1.2%). In others, there are: findings of malignancy, metaplasia, gastric xanthelasma. Regarding the presence of Helicobacter pylori in the sample, the result was: 24% positive, 46% negative, 30% non searched. Conclusion: The results confirm the high frequency of gastric diseases and their incidence in the various age groups additionally to the involvement of H. pylori in such conditions. It is of great importance to characterize the epidemiological data, allowing probable directions for prevention and information programs for population. Keywords: gastric biopsy, gastropathy, epidemiological profile

scholarly journals The correlation between lncRNAs and Helicobacter pylori in gastric cancer

2019 ◽  
Vol 77 (9) ◽  
Author(s):  
Narges Dastmalchi ◽  
Seyed Mahdi Banan Khojasteh ◽  
Mirsaed Miri Nargesi ◽  
Reza Safaralizadeh
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Molecular Mechanisms ◽  
Gastrointestinal Diseases ◽  
Mechanisms Of Action ◽  
Molecular Pathways ◽  
Gastric Diseases ◽  
Non Coding Rnas ◽  
H Pylori ◽  
The Relationship

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

scholarly journals Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liping Tao ◽  
Hai Zou ◽  
Zhimin Huang
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Heat Shock Protein ◽  
Mtt Assay ◽  
Heat Shock Protein 70 ◽  
Hsp70 Expression ◽  
Gastric Epithelial Cells ◽  
Ags Cells ◽  
H Pylori

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.

Prospective Assessment of Helicobacter Pylori Infection and Gastric Pathologies in Sidi Bel Abbes region, Western Algeria

2018 ◽  
Vol 7 (5) ◽  
pp. 217-224
Author(s):  
Zouaouia Chama ◽  
Khedoudj Kanoun ◽  
Fatima Zohra Elkadi ◽  
Kara Turqui Douidi ◽  
Noria Harir ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Histological Study ◽  
Helicobacter Pylori Infection ◽  
University Hospital ◽  
Infection Prevalence ◽  
Gastric Diseases ◽  
Number Of Patients ◽  
H Pylori ◽  
The Impact

Helicobacter pylori infection concerns half of the world’s population, mainly in developing countries. It causes several gastrodudenal pathologies such as gastritis, ulcer and gastric adenocarcinoma. The aim of our study was to determine the prevalence of H.pylori infection and to assess the impact of different epidemiological factors as well as principal gastric diseases associ-ated to this infection. We underwent a prospective study during 18 months (month 2016-month 2017) which implicated 201 symptomatic patients for gastric fiboptic endoscopy at the level of Sidi Bel Abbes University hospital. We collected patients’ biopsies to perform a histological study and H. pylori culture. H. pylori identification was carried out based on bacteriological and biochemical analysis. The middle age of our population was (47.29 ±15.97ans) and the sex-ratio =0,8. The global prevalence of Helicobacter pylori infection is of 61.2% (123/201). This rate, after a statistic analysis, seems to be significantly related to age. It is particularly high especially for patients belonging to age range (20-30)-(51-60) years. The gender did not affect the infection prevalence that is more frequent in the gastritis case. We noticed also that HP infection prevalence was important in SBA the hospital. The range age (20-30)-(51-60) years had the highest prevalence of H. pylori and of gastritis which might be a risky ground of gastric cancer appearance. The ulcer pathology maximal rate concerned the group of 51 to 60 years. Above this age, this rate dropped whereas the number of patients suffering from gastric cancer, which presents an important rate in our study, increase for the group of 61-70 years.

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