scholarly journals Mecanismos Moleculares de Adesão e Colonização da Mucosa Gástrica pela Helicobacter pylori e suas Implicações Clínicas

2016 ◽  
Vol 29 (7-8) ◽  
pp. 476 ◽  
Author(s):  
Elisabete Coelho ◽  
Ana Magalhães ◽  
Mário Dinis-Ribeiro ◽  
Celso A. Reis

Introduction: Helicobacter pylori infection is very prevalent worldwide and is associated with the progression of the gastriccarcinogenesis cascade, being one of the main risk factors for the development of gastric carcinoma. Several factors are determinant for the infection and for the development of gastric disease, including environmental factors, host genetic factors and virulence factors of the bacteria.Material and Methods: In this review, we present an overview of the current knowledge on the determinants of the infection and on the recently described molecular mechanisms of Helicobacter pylori adhesion to the gastric mucosa, as well as its possible future therapeutic application.Results: The adhesion of Helicobacter pylori to the gastric epithelium is critical for gastric pathogenesis, allowing bacterial access to nutrients and the action of bacterial virulence factors, promoting recurrence of the infection and the progression of the gastric carcinogenesis pathway.Discussion: Eradication of Helicobacter pylori infection is the best preventive strategy available against gastric cancer, mainly if it is achieved before the development of pre-neoplastic lesions. The increase in antibiotics resistance, together with the eradication failures in some patients, has promoted the development of alternative treatments.Conclusion: The new therapeutic strategies, focused on the molecular mechanism of Helicobacter pylori adhesion, are very promising; however, future studies are needed to evaluate its in vivo efficiency and toxicity.


2019 ◽  
Vol 316 (2) ◽  
pp. G251-G262 ◽  
Author(s):  
Jon N. Buzzelli ◽  
Louise O’Connor ◽  
Michelle Scurr ◽  
Sharleen Chung Nien Chin ◽  
Angelique Catubig ◽  
...  

Expression of the cytokine IL-11 is elevated in human Helicobacter pylori infection and progressively increases with worsening gastric pathology. Additionally, IL-11 is required for tumor development in STAT3-dependent murine models of gastric cancer (GC) and, when administered acutely, causes resolving atrophic gastritis. However, it is unclear whether locally elevated IL-11 ligand expression can, in isolation from oncogenic gp130-JAK-STAT pathway mutations, initiate GC pathogenesis. Here we developed a transgenic mouse model of stomach-specific (keratin 19 promoter) IL-11 ligand overexpression. Keratin 19 promoter-IL-11 transgenic ( K19-IL11Tg) mice showed specific IL-11 overexpression in gastric corpus and antrum but not elsewhere in the gastrointestinal tract or in other tissues. K19-IL11Tg mice developed spontaneous premalignant disease of the gastric epithelium, progressing from atrophic gastritis to TFF2-positive metaplasia and severe epithelial hyperplasia, including adenoma-like lesions in a subset of older (1 yr old) animals. Although locally advanced, the hyperplastic lesions remained noninvasive. H. pylori infection in K19-IL11Tg mice accelerated some aspects of the premalignant phenotype. Finally, K19-IL11Tg mice had splenomegaly in association with elevated serum IL-11, with spleens showing an expanded myeloid compartment. Our results provide direct in vivo functional evidence that stomach-specific overexpression of IL-11, in isolation from germline gp130-JAK-STAT3 genetic drivers, is sufficient for premalignant progression. These findings have important functional implications for human GC, in which frequent IL-11 overexpression occurs in the reported absence of somatic mutations in gp130 signaling components. NEW & NOTEWORTHY We provide direct in vivo functional evidence that stomach-specific overexpression of the cytokine IL-11, in isolation from gp130-JAK-STAT3 pathway mutations, can trigger spontaneous atrophic gastritis progressing to locally advanced epithelial hyperplasia (but not dysplasia or carcinoma), which does not require, but may be accelerated by, concomitant Helicobacter pylori infection.



2001 ◽  
Vol 120 (5) ◽  
pp. A670-A670
Author(s):  
M NERI ◽  
G DAVI ◽  
D FESTI ◽  
F LATERZA ◽  
A FALCO ◽  
...  


Helicobacter ◽  
2005 ◽  
Vol 10 (2) ◽  
pp. 136-138 ◽  
Author(s):  
Rassa Shahidzadeh ◽  
Antone Opekun ◽  
Akiko Shiotani ◽  
David Y. Graham


Author(s):  
Hazim Abdul Rahman Alhit

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



Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 193 ◽  
Author(s):  
Yasuyoshi Miyata ◽  
Yohei Shida ◽  
Tomoaki Hakariya ◽  
Hideki Sakai

Prostate cancer is the most common cancer among men. Green tea consumption is reported to play an important role in the prevention of carcinogenesis in many types of malignancies, including prostate cancer; however, epidemiological studies show conflicting results regarding these anti-cancer effects. In recent years, in addition to prevention, many investigators have shown the efficacy and safety of green tea polyphenols and combination therapies with green tea extracts and anti-cancer agents in in vivo and in vitro studies. Furthermore, numerous studies have revealed the molecular mechanisms of the anti-cancer effects of green tea extracts. We believe that improved understanding of the detailed pathological roles at the molecular level is important to evaluate the prevention and treatment of prostate cancer. Therefore, in this review, we present current knowledge regarding the anti-cancer effects of green tea extracts in the prevention and treatment of prostate cancer, with a particular focus on the molecular mechanisms of action, such as influencing tumor growth, apoptosis, androgen receptor signaling, cell cycle, and various malignant behaviors. Finally, the future direction for the use of green tea extracts as treatment strategies in patients with prostate cancer is introduced.



2020 ◽  
Vol 11 (5) ◽  
pp. 4525-4534
Author(s):  
Carla Palacios-Gorba ◽  
Raquel Pina ◽  
Miguel Tortajada-Girbés ◽  
Ana Jiménez-Belenguer ◽  
Érica Siguemoto ◽  
...  

Fucoidan effectively reduces H. pylori infection.



2020 ◽  
Vol 318 (5) ◽  
pp. G931-G945 ◽  
Author(s):  
Elizabeth A. Marcus ◽  
Elmira Tokhtaeva ◽  
Jossue L. Jimenez ◽  
Yi Wen ◽  
Bita V. Naini ◽  
...  

This work provides evidence that Helicobacter pylori decreases levels of Na-K-ATPase, a vital transport enzyme, in gastric epithelia, both in acutely infected cultured cells and in chronically infected patients and animals. The bacteria interfere with BiP-assisted folding of newly-made Na-K-ATPase subunits in the endoplasmic reticulum, accelerating their ubiquitylation and proteasomal degradation and decreasing efficiency of the assembly of native enzyme. Decreased Na-K-ATPase expression contributes to H. pylori-induced gastric injury.



Sign in / Sign up

Export Citation Format

Share Document