Helicobacter pylori infection induces gastric precancerous lesions and persistent expression of Angpt2, Vegf-A and Tnf-A in a mouse model

Helicobacter pylori infection promotes M1 macrophage polarization and gastric inflammation by activation of NLRP3 inflammasome via TNF/TNFR1 axis

BACKGROUND

Macrophages play a crucial role in chronic gastritis induced by the pathogenic Helicobacter pylori (H. pylori) infection. NLRP3 inflammasome has emerged as an important component of inflammatory processes. However, the molecular mechanism by which H. pylori infection drives NLRP3 inflammasome and macrophages activation remains unclear.

METHODS

Human gastritis tissues were collected for clinical significance of NLRP3. Infection with H. pylori was performed using in vitro and in vivo models. Bone marrow-derived macrophages (BMDMs) from wild-type (WT), Nlrp3-knockout (KO) and Tnfr1-KO mice were infected with H. pylori. Western blotting, qRT-PCR, immunofluorescence, immunohistochemistry and ELISA were utilized for functional and mechanistic studies.

RESULTS

Single-cell RNA sequencing (ScRNA-seq) analysis of human gastric tissues, followed by validation, indicated that NLRP3 was primarily expressed in myeloid cells and was significantly increased in H. pylori-positive gastritis compared to H. pylori-negative gastritis. Infection with PMSS1 and NCTC11637 H. pylori strains induced NLRP3 inflammasome activation in vitro (THP1 cells) and in the insulin-gastrin (INS-GAS) transgenic mouse model. Deletion of NLRP3 in BMDMs showed marked inhibition of H. pylori-induced M1 macrophage polarization. Furthermore, NLRP3 inflammasome activation upon TNFα, or H. pylori stimulation, was partially blocked by TNFα/TNFR1 signaling inhibitors. Deletion of TNFR1 in BMDMs significantly impaired NLRP3 inflammasome activation and M1 macrophages induced by H. pylori.

CONCLUSION

This study revealed that the activation of NLRP3 inflammasome, regulated by the TNF/TNFR1 signaling axis, is a key regulator of H. pylori-induced M1 macrophage activation and gastritis.

Serum levels of oxidative stress, IL-8, and pepsinogen I/II ratio in Helicobacter pylori and gastric cancer patients: potential diagnostic biomarkers

BACKGROUND AND AIM

Helicobacter pylori (H.pylori), a gram-negative bacterial pathogen associated with an increased risk of gastric cancer. This study investigates potential factors in the incidence of gastric cancer in patients with H.pylori, including oxidative stress, inflammatory biomarkers, serum pepsinogens (PG) of I and II, and PG-I/PG-II ratio.

METHODS

The study comprised individuals with Helicobacter pylori (H.pylori) infection, gastric cancer patients, and healthy individuals. Biochemical parameters such as FBS (fasting blood sugar), lipid profile, and liver and kidney functional factors were evaluated using colorimetric techniques. Oxidative markers such as total oxidant status (TOS) and malondialdehyde (MDA) were quantified through colorimetric methods. IL-8, PG-II, and PG-II levels were also determined using the ELISA technique.

RESULTS

Individuals with H. pylori infection exhibited elevated levels of IL-8 (940.5 ± 249.7 vs. 603.4 ± 89.1 pg/ml, P < 0.0001) and oxidative species (5.47 ± 0.7 vs. 1.64 ± 0.7 nM, P < 0.05) compared to gastric cancer patients, who, despite having lower levels of IL-8 and oxidative species, showed higher levels of MDA. H.pylori patients exhibited significantly higher levels of PG-I (7.28 ± 2.1 vs. 2.61 ± 1.4 ng/ml, P < 0.001), PG-II (3.21 ± 1 vs. 2.6 ± 0.6 ng/ml, P < 0.001), and the PG-I/PG-II ratio (2.27 ± 1.2 vs. 1 ± 0.4, P < 0.001) compared to gastric cancer patients. The findings were substantiated using various data analysis platforms such as Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN (The University of ALabama at Birmingham CANcer data analysis), cBioPortal, and TIMER (Tumor IMmune Estimation Resource). These parameters could serve as potential diagnostic biomarkers for screening and therapeutic interventions based on the cut-off values derived from ROC (receiver operating characteristic) curves for IL-8, PGI, PGII, and PGI/PGII across the three groups.

CONCLUSIONS

IL-8, PGI, PGII, and PGI/PGII parameters could serve as potential diagnostic markers for the screening and treatment of gastric conditions.

Effect of Helicobacter pylori-related chronic gastritis on gastrointestinal microorganisms and brain neurotransmitters in mice

The effects of Helicobacter pylori (Hp)-related chronic gastritis on gastrointestinal microorganisms or brain neurotransmitters are not fully understood. Here, this study selected SPF C57BL/6 mice to set up a Hp-related chronic gastritis experiment group and a blank control group, and used omics to explore the specific effects of Hp-related chronic gastritis on gastrointestinal microorganisms and brain neurotransmitters in mice. The Tyramine (TyrA) content in the female experiment group's brain was considerably reduced compared to the female control group (p < 0.01), and TyrA was strongly correlated with 13 gastrointestinal microorganisms with significant differences, such as Acinetobacter_baumannii (p < 0.05). The His content in the male experiment group's brain was significantly higher than that in the male control group (p < 0.05), and His was strongly correlated with four gastrointestinal microorganisms with significant differences, such as Acinetobacter_baumannii (p < 0.05). The Levodopa (DOPA) content in the female control group's brain was significantly lower than that in the male control group (p < 0.05), and DOPA was strongly correlated with 19 gastrointestinal microorganisms with significant differences, such as Achromobacter_xylosoxidans (p < 0.05). The contents of L-Glutamine (Gln), L-Glutamine (GABA), Noradrenaline hydrochloride (NE), and Adrenaline hydrochloride (E) in the female experiment group's brain were significantly lower than those in the male experiment group (p < 0.05), and Gln, GABA, NE, and E were strongly correlated with 41, 28, 40, and 33 gastrointestinal microorganisms with significant differences (p < 0.05), respectively. These results indicate that Hp-related chronic gastritis could affect gastrointestinal microorganisms and brain neurotransmitters in mice with certain gender differences, and the changes in brain neurotransmitters might be related to the changes in gastrointestinal microorganisms.

Antitumor Effects of Resveratrol Opposing Mechanisms of Helicobacter pylori in Gastric Cancer

Gastric cancer is an aggressive and multifactorial disease. Helicobacter pylori (H. pylori) is identified as a significant etiological factor in gastric cancer. Although only a fraction of patients infected with H. pylori progresses to gastric cancer, bacterial infection is critical in the pathology and development of this malignancy. The pathogenic mechanisms of this bacterium involve the disruption of the gastric epithelial barrier and the induction of chronic inflammation, oxidative stress, angiogenesis and metastasis. Adherence molecules, virulence (CagA and VacA) and colonization (urease) factors are important in its pathogenicity. On the other hand, resveratrol is a natural polyphenol with anti-inflammatory and antioxidant properties. Resveratrol also inhibits cancer cell proliferation and angiogenesis, suggesting a role as a potential therapeutic agent against cancer. This review explores resveratrol as an alternative cancer treatment, particularly against H. pylori-induced gastric cancer, due to its ability to mitigate the pathogenic effects induced by bacterial infection. Resveratrol has shown efficacy in reducing the proliferation of gastric cancer cells in vitro and in vivo. Moreover, the synergistic effects of resveratrol with chemotherapy and radiotherapy underline its therapeutic potential. However, further research is needed to fully describe its efficacy and safety in treating gastric cancer.

Impact of Helicobacter pylori and metabolic syndrome on mast cell activation-related pathophysiology and neurodegeneration

Both Helicobacter pylori (H. pylori) infection and metabolic syndrome (MetS) are highly prevalent worldwide. The emergence of relevant research suggesting a pathogenic linkage between H. pylori infection and MetS-related cardio-cerebrovascular diseases and neurodegenerative disorders, particularly through mechanisms involving brain pericyte deficiency, hyperhomocysteinemia, hyperfibrinogenemia, elevated lipoprotein-a, galectin-3 overexpression, atrial fibrillation, and gut dysbiosis, has raised stimulating questions regarding their pathophysiology and its translational implications for clinicians. An additional stimulating aspect refers to H. pylori and MetS-related activation of innate immune cells, mast cells (MC), which is an important, often early, event in systemic inflammatory pathologies and related brain disorders. Synoptically, MC degranulation may play a role in the pathogenesis of H. pylori and MetS-related obesity, adipokine effects, dyslipidemia, diabetes mellitus, insulin resistance, arterial hypertension, vascular dysfunction and arterial stiffness, an early indicator of atherosclerosis associated with cardio-cerebrovascular and neurodegenerative disorders. Meningeal MC can be activated by triggers including stress and toxins resulting in vascular changes and neurodegeneration. Likewise, H.pylori and MetS-related MC activation is linked with: (a) vasculitis and thromboembolic events that increase the risk of cardio-cerebrovascular and neurodegenerative disorders, and (b) gut dysbiosis-associated neurodegeneration, whereas modulation of gut microbiota and MC activation may promote neuroprotection. This narrative review investigates the intricate relationship between H. pylori infection, MetS, MC activation, and their collective impact on pathophysiological processes linked to neurodegeneration. Through a comprehensive search of current literature, we elucidate the mechanisms through which H. pylori and MetS contribute to MC activation, subsequently triggering cascades of inflammatory responses. This highlights the role of MC as key mediators in the pathogenesis of cardio-cerebrovascular and neurodegenerative disorders, emphasizing their involvement in neuroinflammation, vascular dysfunction and, ultimately, neuronal damage. Although further research is warranted, we provide a novel perspective on the pathophysiology and management of brain disorders by exploring potential therapeutic strategies targeting H. pylori eradication, MetS management, and modulation of MC to mitigate neurodegeneration risk while promoting neuroprotection.