Transgenically expressed Helicobacter pylori CagA in vascular endothelial cells accelerates arteriosclerosis in mice

Extracellular vesicles and endothelial dysfunction in infectious diseases

Cardiovascular diseases (CVDs) remain the leading cause of mortality and morbidity globally. Studies have shown that infections especially bacteraemia and sepsis are associated with increased risks for endothelial dysfunction and related CVDs including atherosclerosis. Extracellular vesicles (EVs) are small, sealed membrane-derived structures that are released into body fluids and blood from cells and/or microbes and are critically involved in a variety of important cell functions and disease development, including intercellular communications, immune responses and inflammation. It is known that EVs-mediated mechanism(s) is important in the development of endothelial dysfunction in infections with a diverse spectrum of microorganisms including Escherichia coli, Candida albicans, SARS-CoV-2 (the virus for COVID-19) and Helicobacter pylori. H. pylori infection is one of the most common infections globally. During H. pylori infection, EVs can carry H. pylori components, such as lipopolysaccharide, cytotoxin-associated gene A, or vacuolating cytotoxin A, and transfer these substances into endothelial cells, triggering inflammatory responses and endothelial dysfunction. This review is to illustrate the important role of EVs in the pathogenesis of infectious diseases, and the development of endothelial dysfunction in infectious diseases especially H. pylori infection, and to discuss the potential mechanisms and clinical implications.

The Interplay between Helicobacter pylori and Gut Microbiota in Non-Gastrointestinal Disorders: A Special Focus on Atherosclerosis

The discovery of Helicobacter pylori (H. pylori) in the early 1980s by Nobel Prize winners in medicine Robin Warren and Barry Marshall led to a revolution in physiopathology and consequently in the treatment of peptic ulcer disease. Subsequently, H. pylori has also been linked to non-gastrointestinal diseases, such as autoimmune thrombocytopenia, acne rosacea, and Raynaud's syndrome. In addition, several studies have shown an association with cardiovascular disease and atherosclerosis. Our narrative review aims to investigate the connection between H. pylori infection, gut microbiota, and extra-gastric diseases, with a particular emphasis on atherosclerosis. We conducted an extensive search on PubMed, Google Scholar, and Scopus, using the keywords "H. pylori", "dysbiosis", "microbiota", "atherosclerosis", "cardiovascular disease" in the last ten years. Atherosclerosis is a complex condition in which the arteries thicken or harden due to plaque deposits in the inner lining of an artery and is associated with several cardiovascular diseases. Recent research has highlighted the role of the microbiota in the pathogenesis of this group of diseases. H. pylori is able to both directly influence the onset of atherosclerosis and negatively modulate the microbiota. H. pylori is an important factor in promoting atherosclerosis. Progress is being made in understanding the underlying mechanisms, which could open the way to interesting new therapeutic perspectives.

Both extracellular vesicles from helicobacter pylori-infected cells and helicobacter pylori outer membrane vesicles are involved in gastric/extragastric diseases

Bacterial-derived extracellular vesicles (EVs) have emerged as crucial mediators in the cross-talk between hosts and pathogens, playing a significant role in infectious diseases and cancers. Among these pathogens, Helicobacter pylori (H. pylori) is a particularly important bacterium implicated in various gastrointestinal disorders, gastric cancers, and systemic illnesses. H. pylori achieves these effects by stimulating host cells to secrete EVs and generating internal outer membrane vesicles (OMVs). The EVs derived from H. pylori-infected host cells modulate inflammatory signaling pathways, thereby affecting cell proliferation, apoptosis, cytokine release, immune cell modification, and endothelial dysfunction, as well as disrupting cellular junctional structures and inducing cytoskeletal reorganization. In addition, OMVs isolated from H. pylori play a pivotal role in shaping subsequent immunopathological responses. These vesicles incite both inflammatory and immunosuppressive reactions within the host environment, facilitating pathogen evasion of host defenses and invasion of host cells. Despite this growing understanding, research involving H. pylori-derived EVs remains in its early stages across different domains. In this comprehensive review, we present recent advancements elucidating the contributions of EV components, such as non-coding RNAs (ncRNAs) and proteins, to the pathogenesis of gastric and extragastric diseases. Furthermore, we highlight their potential utility as biomarkers, therapeutic targets, and vehicles for targeted delivery.

Infection with Helicobacter pylori may predispose to atherosclerosis: role of inflammation and thickening of intima-media of carotid arteries

Atherosclerosis is a major instigator of cardiovascular disease (CVD) and a main cause of global morbidity and mortality. The high prevalence of CVD calls for urgent attention to possible preventive measures in order to curb its incidence. Traditional risk factors of atherosclerosis, like age, smoking, diabetes mellitus, dyslipidemia, hypertension and chronic inflammation, are under extensive investigation. However, these only account for around 50% of the etiology of atherosclerosis, mandating a search for different or overlooked risk factors. In this regard, chronic infections, by Helicobacter pylori for instance, are a primary candidate. H. pylori colonizes the gut and contributes to several gastrointestinal diseases, but, recently, the potential involvement of this bacterium in extra-gastric diseases including CVD has been under the spotlight. Indeed, H. pylori infection appears to stimulate foam cell formation as well as chronic immune responses that could upregulate key inflammatory mediators including cytokines, C-reactive protein, and lipoproteins. These factors are involved in the thickening of intima-media of carotid arteries (CIMT), a hallmark of atherosclerosis. Interestingly, H. pylori infection was found to increase (CIMT), which along with other evidence, could implicate H. pylori in the pathogenesis of atherosclerosis. Nevertheless, the involvement of H. pylori in CVD and atherosclerosis remains controversial as several studies report no connection between H. pylori and atherosclerosis. This review examines and critically discusses the evidence that argues for a potential role of this bacterium in atherogenesis. However, additional basic and clinical research studies are warranted to convincingly establish the association between H. pylori and atherosclerosis.

Hp0521 inhibited the virulence of H. pylori 26,695 strain via regulating CagA expression

Hp0521 is the number of cag pathogenicity island (cagPAI) family in Helicobacter pylori (H. pylori, Hp), which encoded Cag2 protein. The aim of this study was to investigate the role of hp0521 on the H. pylori 26,695 strain. We constructed the recombinant prokaryotic expression plasmid pET-32a-hp0521 and pET-32a-hpc0521. Then, we co-cultured the H. pylori wild strain 26,695 and Δhp0521 strain with GES-1 cells to detect CagA protein transport and IL-8 secretion. We found that Δhp0521 mutation increased the expression of cagA, rpoB and promoted the transportation of CagA protein in GES-1 cells. In addition, we also observed that Δhp0521 mutation had no effect on other cagPAI protein stability and the expression of IL-8. Our findings suggested that hp0521 may down-regulated the expression of cagA, rpoB and inhibited the transportation of CagA protein in GES-1 cells and had no effect on growth.

Helicobacter Pylori Virulence Factor Cytotoxin-Associated Gene A (CagA) Induces Vascular Calcification in Coronary Artery Smooth Muscle Cells

Helicobacter pylori (H. pylori) has been associated with cardiovascular diseases. The pro-inflammatory H. pylori virulence factor cytotoxin-associated gene A (CagA) has been detected in serum exosomes of H. pylori-infected subjects and may exert systemic effects throughout the cardiovascular system. The role of H. pylori and CagA in vascular calcification was hitherto unknown. The aim of this study was to determine the vascular effects of CagA through human coronary artery smooth muscle cell (CASMC) osteogenic and pro-inflammatory effector gene expression as well as interleukin 1β secretion and cellular calcification. CagA upregulated bone morphogenic protein 2 (BMP-2) associated with an osteogenic CASMC phenotype switch and induced increased cellular calcification. Furthermore, a pro-inflammatory response was observed. These results support that H. pylori may contribute to vascular calcification through CagA rendering CASMCs osteogenic and inducing calcification.

Helicobacter pylori and cardiovascular risk: Only a dead Helicobacter is a good Helicobacter?

OBJECTIVES

Helicobacter pylori (H. pylori) and cardiovascular (CV) disease share common symptoms and underlie many general medical complaints. Preliminary studies suggest an association between H. pylori positivity and CV risk, and gastroenterological guidelines recommend eradication of H. pylori in patients with manifest atherosclerosis. Therefore, the aim of this study was to examine the reciprocal association of H. pylori positivity and CV risk for their independence of shared risk factors.

METHODS

We included 3284 asymptomatic participants of a colorectal cancer screening cohort who were offered and underwent upper gastrointestinal endoscopy. We calculated the 10-year risk for a CV event using the novel SCORE2 for each patient. We evaluated the association between H. pylori positivity and CV risk assessed by SCORE2 using both multilevel logistic and linear regression. We adjusted for age, sex and the concomitant diagnosis of metabolic syndrome. Lastly, we assessed the association between H. pylori status and mortality using proportional hazard Cox regression.

RESULTS

In total, 2659 patients were H. pylori negative and 625 H. pylori positive. Helicobacter pylori positivity was associated with SCORE2 and remained so (r = .33; 95% CI 0.09-0.57; p = .006) after adjustment for age, sex, and the diagnosis of metabolic syndrome. Also, SCORE2 was associated with higher odds for H. pylori positivity (aOR 1.03 95% CI 1.01-1.05; p = .02) even after multivariable adjustment. Helicobacter pylori positivity was associated with neither CV (HR 0.60 95% CI 0.14-2.63; p = .50) nor all-cause (HR 1.20 95% CI 0.77-1.87; p = .43) mortality during a median follow-up of 9 years.

CONCLUSIONS

In our study, H. pylori positivity and CV risk were independently associated. This did not translate into a dissimilar CV mortality between H. pylori positive and H. pylori negative patients. However, the overwhelming majority of our patients underwent H. pylori eradication. We, therefore, think that H. pylori eradication is at least safe from a cardiovascular perspective and warranted from gastrointestinal standpoint.