Molecular docking of a set of flavonoid compounds with Helicobacter pylori virulence factors CagA and VacA

Introduction: Cytotoxin associated gene A (CagA) and vacuolating cytotoxin A (VacA) proteins are the main Helicobacter pylori virulence factors. These toxins are associated with severe gastric diseases. Flavonoids are plant secondary metabolites that have shown great antibacterial effects. This work aimed to study the interaction of a set of flavonoid compounds with CagA and VacA proteins using molecular docking.Methods: A set of 54 flavonoid compounds were used in this study, and 36 of which passed the Lipinski rules of 5. The 3D structures of CagA and VacA proteins were obtained from the Protein Data Bank. The molecular docking was performed using AutoDock Vina software and the results were expressed in terms of binding energies (kcal/mol). Protein-ligand interactions were analyzed using PyMOL software.Results: For the CagA protein, the licochalcone A molecule showed the highest binding affinity (-8 kcal/mol). For the VacA protein, the galangin, luteolin, and apigenin molecules showed the highest binding affinity (-8.9, -8.5, and -8.2 kcal/mol, respectively). Interactions of the licochalcone A, galangin, luteolin, and apigenin with CagA and VacA proteins involved their hydroxyl groups and/or their carbonyl groups.Conclusion: Our study showed that these compounds might have the potential for their development into drugs for controlling H. pylori pathogenicity.

Association of Helicobacter pylori vacA polymorphisms with the risk of gastric precancerous lesions in a Moroccan population

INTRODUCTION

Helicobacter pylori infection is the major risk factor of atrophic gastritis and intestinal metaplasia. The vacA gene is one of the most virulence factors of H. pylori and genetic diversity in its s, m, i, and d regions is associated with gastric lesions severity. This study aimed to investigate the association of vacA s, m, i, and d regions with the risk of atrophic gastritis and intestinal metaplasia in a Casablanca population.

METHODOLOGY

A total of 210 patients suffering from gastric lesions (chronic gastritis, atrophic gastritis, and intestinal metaplasia) were enrolled. The type of lesion was diagnosed by histological examination. Detection of H. pylori infection and genotyping of vacA regions were carried out by PCR.

RESULTS

The prevalence of H. pylori was 95%. The most common vacA genotypes were s2 (51.5%), m2 (77%), i2 (60.5%), and d2 (58.5%). VacA s1, m1, and i1 genotypes were associated with a high risk of intestinal metaplasia, while the vacA d1 genotype increases the risk of atrophic gastritis and intestinal metaplasia. The most common vacA combination was s2/m2/i2/d2 (52%), and it was more detected in chronic gastritis. The moderate virulent vacA combination (s1/m2/i1/d1) increases the risk of atrophic gastritis, while the most virulent vacA combination (s1/m1/i1/d1) increases the risk of intestinal metaplasia.

CONCLUSIONS

Genotyping of vacA d region might be a reliable marker for the identification of vacA virulent strains that represent a high risk of developing precancerous lesions (atrophic gastritis and intestinal metaplasia).

Upstream stimulating factor 1 (USF1) -202 G/A polymorphism and serum levels of USF1 and USF2 are associated with gastric cancer risk: a case control study

PURPOSE

Gastric cancer is an inflammation-driven disease often associated with a bad prognosis. Upstream stimulatory factors USF1 and USF2 are pleiotropic transcription factors, with tumor suppressor function. Low expression of USF1 is associated with low survival in gastric cancer patients. USF1 genetic polymorphism -202G > A has been associated with cancer susceptibility. Our aim was to investigate USF1 gene polymorphism and serum level with the risk of gastric cancer.

METHODS

USF1-202 G/A polymorphism was analyzed by sanger sequencing, with the measure of USF1/USF2 serum levels by ELISA in H. pylori-positive patients with chronic gastritis, gastric precancerous lesions, gastric cancer and in healthy controls.

RESULTS

Our results show that the presence of the USF1-202 A allele increased the risk of gastric cancer compared to G (OR = 2; 95% CI 1.07-3.9; P = 0.02). Genotypically and under the dominant mutation model, the combined USF1- GA/AA -202 genotypes corresponded to higher risk of gastric cancer (OR = 3.5; 95% CI 1.4-8.2; p-value = 0.005) than the GG genotype. Moreover, the G/A transition at USF1-202 was associated with lower USF1 serum level, and mostly observed in gastric cancer patients where the average serological level of USF1 were 2.3 and twofold lower for the AA and GA genotypes, respectively, compared to GG.

CONCLUSION

USF1-202 G/A polymorphism constitutes a gastric cancer genetic risk factor. Together with USF1/USF2 serum level, they can be proposed as promising biomarkers for gastric cancer detection/prevention.

Comparative Study of Helicobacter Pylori Resistance to Clarithromycin and Metronidazole and Its Association with Epidemiological Factors in A Moroccan Population

OBJECTIVE

Knowledge of local antibiotic resistance is crucial to the adaption of the effective empirical first-line treatment for Helicobacter Pylori (H. pylori) infection. This study aimed to evaluate the prevalence of H. pylori resistance to clarithromycin and compare it with that of metronidazole, and highlight the impact of epidemiological factors and gastric lesions severity on H. pylori resistance.

METHODS

The susceptibility to clarithromycin of 96 isolates was determined by PCR-RFLP and the susceptibility to metronidazole of 185 isolates was determined by classic PCR.

RESULT

Our results showed that the prevalence of H. pylori resistance to clarithromycin (‎14.6%) was low compared to that recorded with metronidazole (‎62.7%). Moreover, we remarked that 7.3% of isolates were co-resistant to both antibiotics. The assessment of epidemiological factors' impact on the resistance to studied antibiotics has revealed no association. Besides, our results had demonstrated that the metronidazole and clarithromycin resistance was not related to the severity of gastric lesions.

CONCLUSION

In our population, clarithromycin seems to be an effective antibiotic as long as the resistance rate of H. pylori is low. In contrast to metronidazole, it appears that this antibiotic will lose its efficacy, due to the high rate of resistance among our population. Therefore, each population must conduct their epidemiologic studies separately to survey the resistance profile of strains and choose the appropriate antibiotic, in order to avoid the failure of H. pylori eradication and the development of severe gastric diseases.

The EPIYA-ABCC motif of Helicobacter pylori cagA gene and gastric carcinogenesis in Casablanca population

Background: H. pylori infection induce atrophic gastritis (AG) and intestinal metaplasia (IM) that can lead to gastric cancer (GC). The severity of gastric lesions is related to H. pylori genetic diversity. The oncogenic potential of H. pylori cagA virulence factor is linked to its high polymorphic EPIYA motifs. Objectives: Our aim was to evaluate the association of EPIYA motifs with the risk of AG and IM in Casablanca population. Methods: A total of 210 patients suffering from gastric lesions (chronic gastritis, AG, and IM) was enrolled. H. pylori infection and the type of lesions were diagnosed by ureC PCR and histological examination, respectively. Detection of the cagA gene, and the type of EPIYA motifs, were carried out by PCR Results: The prevalence of H. pylori and cagA gene was 95% and 37%, respectively. CagA-positive strains were associated with the risk of IM. The EPIYA motifs detected were: EPIYA-ABC (58%), EPIYA-ABCC (22%), and EPIYA-AB (20%). The EPIYA-ABCC motif was associated with the risk of IM (p-value = 0.007), compared to AG (p-value = 0.28). Conclusion: The EPIYA-ABCC motif might be a useful marker for the identification of patients at high risk of developing IM that can lead to GC. Keywords: cagA gene; EPIYA motifs; gastric carcinogenesis.