Helicobacter pylori glycan biosynthesis modulates host immune cell recognition and response.

Introduction: The pathogenic bacterium Helicobacter pylori has evolved glycan-mediated mechanisms to evade host immune defenses. This study tests the hypothesis that genetic disruption of H. pylori glycan biosynthesis alters immune recognition and response by human gastric epithelial cells and monocyte-derived dendritic cells. Methods: To test this hypothesis, human cell lines were challenged with wildtype H. pylori alongside an array of H. pylori glycosylation mutants. The relative levels of immune response were measured via immature dendritic cell maturation and cytokine secretion. Results: Our findings indicate that disruption of lipopolysaccharide biosynthesis diminishes gastric cytokine production, without disrupting dendritic cell recognition and activation. In contrast, variable immune responses were observed in protein glycosylation mutants which prompted us to test the hypothesis that phase variation plays a role in regulating bacterial cell surface glycosylation and subsequent immune recognition. Lewis antigen presentation does not correlate with extent of immune response, while the extent of lipopolysaccharide O-antigen elaboration does. Discussion: The outcomes of this study demonstrate that H. pylori glycans modulate the host immune response. This work provides a foundation to pursue immune-based tailoring of bacterial glycans towards modulating immunogenicity of microbial pathogens.

[Pyloric gland adenoma - a rare tumor of the upper gastrointestinal tract with a high risk of malignancy]. / Adenoma piloricheskikh zhelez ­ redkaya opukhol' verkhnikh otdelov zheludochno-kishechnogo trakta s vysokim riskom malignizatsii.

BACKGROUND: Pyloric gland adenomas (PGA) are rare neoplasms of the gastrointestinal tract. According to the literature, these lesions may be underdiagnosed, and their true frequency of occurrence is underestimated. OBJECTIVE: Clinical and morphological analysis of eight PGA cases of the upper gastrointestinal tract. MATERIAL AND METHODS: The study included 8 cases of detection of PGA. In 7 out of 8 cases, the tumor was diagnosed by examining endoscopic biopsies, in 1 case, PGA was an accidental finding in the surgical material after proximal gastric resection. RESULTS: 6 out of 8 patients were female, the median age was 65 years (minimum 36 years and maximum 78 years). In 6 cases, PDA was localized in the stomach, in 1 - in the esophagus and in 1 - in the duodenum The size of the tumors ranged from 0.6 cm to 7.5 cm. 4 out of 6 stomach tumors appeared on the background of confirmed autoimmune gastritis, 1 - on the background of lymphocytic gastritis. 4 tumors were found in the body of the stomach, 1 - in the cardia, 1 - in the bottom of the stomach. In 2 out of 8 cases, there were signs of malignancy of the tumor with the transition to a highly differentiated adenocarcinoma. According to the results of the IHC study, the absence of a p53 mutation was noted in these cases. CONCLUSION: PGA should be considered as neoplasms with a high risk of transformation into invasive adenocarcinoma. Increasing the recognition of PGA among pathologists and further understanding of the molecular mechanisms involved in their neoplastic transformation will improve the diagnosis and treatment of this pathology.

Differential cytokine expression in gastric tissues highlights helicobacter pylori's role in gastritis.

Helicobacter pylori (H. pylori), known for causing gastric inflammation, gastritis and gastric cancer, prompted our study to investigate the differential expression of cytokines in gastric tissues, which is crucial for understanding H. pylori infection and its potential progression to gastric cancer. Focusing on Il-1ß, IL-6, IL-8, IL-12, IL-18, and TNF-α, we analysed gene and protein levels to differentiate between H. pylori-infected and non-infected gastritis. We utilised real-time quantitative polymerase chain reaction (RT-qPCR) for gene quantification, immunohistochemical staining, and ELISA for protein measurement. Gastric samples from patients with gastritis were divided into three groups: (1) non-gastritis (N-group) group, (2) gastritis without H. pylori infection (G-group), and (3) gastritis with H. pylori infection (GH-group), each consisting of 8 samples. Our findings revealed a statistically significant variation in cytokine expression. Generally, cytokine levels were higher in gastritis, but in H. pylori-infected gastritis, IL-1ß, IL-6, and IL-8 levels were lower compared to H. pylori-independent gastritis, while IL-12, IL-18, and TNF-α levels were higher. This distinct cytokine expression pattern in H. pylori-infected gastritis underscores a unique inflammatory response, providing deeper insights into its pathogenesis.

Exploring non-curative endoscopic submucosal dissection: Current treatment optimization and future indication expansion.

The increasing popularity of endoscopic submucosal dissection (ESD) as a treatment for early gastric cancer has highlighted the importance of quality assessment in achieving curative resections. This article emphasizes the significance of evaluating ESD quality, not only for curative cases but also for non-curative ones. Postoperative assessment relies on the endoscopic curability (eCura) classification, but management strategies for eCuraC-1 tumour with a positive horizontal margin are unclear. Current research primarily focuses on comparing additional surgical procedures in high-risk patients, while studies specifically targeting eCuraC-1 patients are limited. Exploring management strategies and follow-up outcomes for such cases could provide valuable insights. Furthermore, the application of molecular imaging using near-infrared fluorescent tracers holds promise for precise tumour diagnosis and navigation, potentially impacting the management of early-stage gastric cancer patients. Advancing research in these areas is essential for improving the overall efficacy of endoscopic techniques and refining treatment indications.

Clinical manifestation, lifestyle, and treatment patterns of chronic erosive gastritis: A multicenter real-world study in China.

BACKGROUND: Although chronic erosive gastritis (CEG) is common, its clinical characteristics have not been fully elucidated. The lack of consensus regarding its treatment has resulted in varied treatment regimens. AIM: To explore the clinical characteristics, treatment patterns, and short-term outcomes in CEG patients in China. METHODS: We recruited patients with chronic non-atrophic or mild-to-moderate atrophic gastritis with erosion based on endoscopy and pathology. Patients and treating physicians completed a questionnaire regarding history, endoscopic findings, and treatment plans as well as a follow-up questionnaire to investigate changes in symptoms after 4 wk of treatment. RESULTS: Three thousand five hundred sixty-three patients from 42 centers across 24 cities in China were included. Epigastric pain (68.0%), abdominal distension (62.6%), and postprandial fullness (47.5%) were the most common presenting symptoms. Gastritis was classified as chronic non-atrophic in 69.9% of patients. Among those with erosive lesions, 72.1% of patients had lesions in the antrum, 51.0% had multiple lesions, and 67.3% had superficial flat lesions. In patients with epigastric pain, the combination of a mucosal protective agent (MPA) and proton pump inhibitor was more effective. For those with postprandial fullness, acid regurgitation, early satiety, or nausea, a MPA appeared more promising. CONCLUSION: CEG is a multifactorial disease which is common in Asian patients and has non-specific symptoms. Gastroscopy may play a major role in its detection and diagnosis. Treatment should be individualized based on symptom profile.

[Therapeutic efficacy analysis of endoscopic combined with serological diagnosis strategy and endoscopic in G1 and G2 gastric neuroendocrine neoplasms].

Objective: To investigate the endoscopic combined serological diagnosis strategy for G1 and G2 gastric neuroendocrine neoplasms (G-NENs), and to evaluate the safety, short-term, and long-term efficacy of two endoscopic treatment procedures: endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Methods: This study retrospectively analyzed the clinical data of 100 consecutive patients with G-NENs who were hospitalized at the Cancer Hospital of the Chinese Academy of Medical Sciences from January 2011 to October 2023. These patients underwent endoscopic treatment, and propensity score matching (PSM) was used to compare clinicopathological characteristics, as well as short-term and long-term efficacy of lesions in the EMR group and ESD group before and after treatment. Results: Among the 100 patients with G-NENs, the median age was 54 years old. Before surgery, 29 cases underwent endoscopic combined serological examination, and 24 of them (82.2%) had abnormally elevated plasma chromogranin A. The combined diagnostic strategy for autoimmune atrophic gastritis (AIG) achieved a diagnostic accuracy of 100%(22/22). A total of 235 G-NEN lesions were included, with 84 in the ESD group and 151 in the EMR group. The median size of the lesions in the ESD group (5.0 mm) was significantly larger than that in the EMR group (2.0 mm, P＜0.001). Additionally, the ESD group had significantly more lesions with pathological grade G2[23.8%(20/84) vs. 1.3%(2/151), P＜0.001], infiltration depth reaching the submucosal layer [78.6%(66/84) vs. 51.0%(77/151), P＜0.001], and more T2 stage compared to the EMR group[15.5%(13/84) vs. 0.7%(1/151), P＜0.001]. After PSM, 49 pairs of lesions were successfully matched between the two groups. Following PSM, there were no significant differences in the en bloc resection rate [100.0%(49/49) vs. 100.0%(49/49)], complete resection rate [93.9%(46/49) vs. 100.0%(49/49)], and complication rate [0(0/49) vs. 4.1%(2/49)] between the two groups. During the follow-up period, no recurrence or distant metastasis was observed in any of the lesions in both groups. Conclusions: The combination of endoscopy and serology diagnostic strategy has the potential to enhance the accuracy of diagnosing G1 and G2 stage G-NENs and their background mucosa. Endoscopic resection surgery (EMR, ESD) is a proven and safe treatment approach for G1 and G2 stage G-NENs.

Helicobacter pylori Eradication Reverses DNA Damage Response Pathway but Not Senescence in Human Gastric Epithelium.

Helicobacter pylori (H. pylori) infection induces DNA Double-Strand Breaks (DSBs) and consequently activates the DNA Damage Response pathway (DDR) and senescence in gastric epithelium. We studied DDR activation and senescence before and after the eradication of the pathogen. Gastric antral and corpus biopsies of 61 patients with H. pylori infection, prior to and after eradication treatment, were analyzed by means of immunohistochemistry/immunofluorescence for DDR marker (γH2AΧ, phosporylated ataxia telangiectasia-mutated (pATM), p53-binding protein (53BP1) and p53) expression. Samples were also evaluated for Ki67 (proliferation index), cleaved caspase-3 (apoptotic index) and GL13 staining (cellular senescence). Ten H. pylori (-) dyspeptic patients served as controls. All patients were re-endoscoped in 72-1361 days (mean value 434 days), and tissue samples were processed in the same manner. The eradication of the microorganism, in human gastric mucosa, downregulates γH2AΧ expression in both the antrum and corpus (p = 0.00019 and p = 0.00081 respectively). The expression of pATM, p53 and 53BP1 is also reduced after eradication. Proliferation and apoptotic indices were reduced, albeit not significantly, after pathogen clearance. Moreover, cellular senescence is increased in H. pylori-infected mucosa and remains unaffected after eradication. Interestingly, senescence was statistically increased in areas of intestinal metaplasia (IM) compared with adjacent non-metaplastic mucosa (p < 0.001). In conclusion, H. pylori infection triggers DSBs, DDR and senescence in the gastric epithelium. Pathogen eradication reverses the DDR activation but not senescence. Increased senescent cells may favor IM persistence, thus potentially contributing to gastric carcinogenesis.

History of chronic gastritis: How our perceptions have changed.

Currently, the diagnostic strategy for chronic gastritis (CG) is aimed not just at fixing the presence of gastric mucosal inflammation, but also at gastric cancer (GC) risk stratification in a particular patient. Modern classification approach with the definition of the stage of gastritis determines the need, activities and frequency of dynamic monitoring of a patient. However, this attitude to the patient suffering from CG was far from always. The present publication is a literature review describing the key milestones in the history of CG research, from the description of the first observations of inflammation of the gastric mucosa, assessment of gastritis as a predominantly functional disease, to the advent of endoscopy of the upper digestive tract and diagnostic gastric biopsy, assessment of the role of Helicobacter pylori infection in progression of inflammatory changes to atrophy, intestinal metaplasia, dysplasia and GC.

Structure characteristics, protective effect and mechanisms of ethanol-fractional polysaccharides from Dendrobium officinale on acute ethanol-induced gastritis.

Gastritis is a common disease characterized by gastric ulcers and severe bleeding. Excessive daily alcohol consumption can cause acute gastritis, impacting individuals' quality of life. This study aims to explore the protective effects of different ethanol-fractional polysaccharides of Dendrobium officinale (EPDO) on acute alcohol-induced gastric injury in vivo. Results showed that EPDO-80, identified as a ß-glucan, exhibited significant anti-inflammatory properties in pathology. It could reduce the area of gastric mucosal injury and cell infiltration. EPDO-80 had a dose-effect relationship in reducing the levels of malondialdehyde and cyclooxygenase-2 and decreasing the levels of inflammation mediators such as tumor necrosis factor α. More extensively, EPDO-80 could inhibit the activation of the TNFR/IκB/NF-κB signaling pathway, reducing the production of TNF-α mRNA and cell apoptosis in organs. Conversely, EPDO-80 could promote changes in the gut microbiota structure. These findings suggest that EPDO-80 could have great potential in limiting oxidative stress and inflammation mediated by inhibiting the NF-κB signaling pathway, which is highly related to its ß-glucan structure and functions in gut microbiota.

IL-33 Accelerates Chronic Atrophic Gastritis through AMPK-ULK1 Axis Mediated Autolysosomal Degradation of GKN1.

Chronic atrophic gastritis (CAG) is a complex disease characterized by atrophy and inflammation in gastric mucosal tissue, especially with high expression of interleukins. However, the interaction and mechanisms between interleukins and gastric mucosal epithelial cells in CAG remain largely elusive. Here, we elucidate that IL-33 stands out as the predominant inflammatory factor in CAG, and its expression is induced by H. pylori and MNNG through the ROS-STAT3 signaling pathway. Furthermore, our findings reveal that the IL-33/ST2 axis is intricately involved in the progression of CAG. Utilizing phosphoproteomics mass spectrometry, we demonstrate that IL-33 enhances autophagy in gastric epithelial cells through the phosphorylation of AMPK-ULK1 axis. Notably, inhibiting autophagy alleviates CAG severity, while augmentation of autophagy exacerbates the disease. Additionally, ROS scavenging emerges as a promising strategy to ameliorate CAG by reducing IL-33 expression and inhibiting autophagy. Intriguingly, IL-33 stimulation promotes GKN1 degradation through the autolysosomal pathway. Clinically, the combined measurement of IL-33 and GKN1 in serum shows potential as diagnostic markers. Our findings unveil an IL-33-AMPK-ULK1 regulatory mechanism governing GKN1 protein stability in CAG, presenting potential therapeutic targets for its treatment.

Clinicopathologic and endoscopic characteristics of ten patients with gastric hamartomatous inverted polyp: a single center case series.

BACKGROUND: Gastric hamartomatous inverted polyps (GHIPs) are not well characterized and remain diagnostically challenging due to rarity. Therefore, this study aims to investigate the clinicopathologic and endoscopic characteristics of patients with GHIP. METHODS: We retrospectively reviewed clinicopathologic and endoscopic features of ten patients with GHIP who were admitted to Beijing Friendship Hospital from March 2013 to July 2022. All patients were treated successfully by endoscopic resection. RESULTS: GHIPs were usually asymptomatic and found incidentally during gastroscopic examination. They may be sessile or pedunculated, with diffuse or local surface redness or erosion. On endoscopic ultrasonography, the sessile submucosal tumor-type GHIP demonstrated a heterogeneous lesion with cystic areas in the third layer of the gastric wall. Histologically, GHIPs were characterized by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands accompanied by a branching proliferation of smooth muscle bundles. Inflammatory cells infiltration was observed in the stroma, whereas only one patient was complicated with glandular low-grade dysplasia. Assessment of the surrounding mucosa demonstrated that six patients (60%) had atrophic gastritis or Helicobacter pylori-associated gastritis, and four patients (40%) had non-specific gastritis. Endoscopic resection was safe and effective. CONCLUSIONS: GHIPs often arise from the background of abnormal mucosa, such as atrophic or H.pylori-associated gastritis. We make the hypothesis that acquired inflammation might lead to the development of GHIPs. We recommend to make a full assessment of the background mucosa and H. pylori infection status for evaluation of underlying gastric mucosal abnormalities, which may be the preneoplastic condition of the stomach.

Gastric digestion of the sweet-tasting plant protein thaumatin releases bitter peptides that reduce H. pylori induced pro-inflammatory IL-17A release via the TAS2R16 bitter taste receptor.

About half of the world's population is infected with the bacterium Helicobacter pylori. For colonization, the bacterium neutralizes the low gastric pH and recruits immune cells to the stomach. The immune cells secrete cytokines, i.e., the pro-inflammatory IL-17A, which directly or indirectly damage surface epithelial cells. Since (I) dietary proteins are known to be digested into bitter tasting peptides in the gastric lumen, and (II) bitter tasting compounds have been demonstrated to reduce the release of pro-inflammatory cytokines through functional involvement of bitter taste receptors (TAS2Rs), we hypothesized that the sweet-tasting plant protein thaumatin would be cleaved into anti-inflammatory bitter peptides during gastric digestion. Using immortalized human parietal cells (HGT-1 cells), we demonstrated a bitter taste receptor TAS2R16-dependent reduction of a H. pylori-evoked IL-17A release by up to 89.7 ± 21.9% (p ≤ 0.01). Functional involvement of TAS2R16 was demonstrated by the study of specific antagonists and siRNA knock-down experiments.