Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development

Helicobacter pylori outer membrane vesicles and infected cell exosomes: new players in host immune modulation and pathogenesis

Outer membrane vesicles (OMVs) and exosomes are essential mediators of host-pathogen interactions. Elucidating their mechanisms of action offers valuable insights into diagnosing and treating infectious diseases and cancers. However, the specific interactions of Helicobacter pylori (H. pylori) with host cells via OMVs and exosomes in modulating host immune responses have not been thoroughly investigated. This review explores how these vesicles elicit inflammatory and immunosuppressive responses in the host environment, facilitate pathogen invasion of host cells, and enable evasion of host defenses, thereby contributing to the progression of gastric diseases and extra-gastric diseases disseminated through the bloodstream. Furthermore, the review discusses the challenges and future directions for investigating OMVs and exosomes, underscoring their potential as therapeutic targets in H. pylori-associated diseases.

Proteomic Insights Into Gingival Crevicular Extracellular Vesicles in Periodontitis and Gestational Diabetes: An Exploratory Study

AIM

To characterize the gingival crevicular fluid (GCF) and plasma extracellular vesicles (EVs) and explore their proteomic cargo in healthy pregnant women compared to those with gestational diabetes mellitus (GDM) and periodontitis.

METHODS

One-hundred and four pregnant women were recruited at 24-30 gestation weeks. GDM was diagnosed by an oral glucose tolerance test. GCF and plasma samples were obtained to isolate EVs and characterized by nanoparticle tracking, immunoassays, electron microscopy and mass spectrometry.

RESULTS

Of the recruits,17.3% women were healthy, 50% had periodontitis and 32.7% had both GDM and periodontitis. Probing depth, clinical attachment loss and bleeding on probing were more severe in GDM and periodontitis pregnancies (p < 0.0001). Additionally, this group showed an increase concentration of total, small and large GCF-EVs (p = 0.0015, p = 0.0011 and p = 0.0008, respectively), with decreased expression of CD9, CD81 and CD81/CD63 ratio (p = 0.0461, p = 0.0164 and p = 0.0005, respectively). No differences were observed in plasmatic EVs concentration or markers expression. Proteomic analysis of GCF-EVs showed peptides of both host and bacterial origin. Gene ontology analysis revealed that proteins of GCF-EVs participate in immune inflammatory responses, glucose metabolism and insulin response mechanisms.

CONCLUSION

GCF-EVs were increased in both GDM and periodontitis, and their proteomic cargo suggest their involvement in immune inflammatory response, glucose metabolism and insulin pathways during pregnancy.

The effect of Helicobacter pylori-derived extracellular vesicles on glucose metabolism and induction of insulin resistance in HepG2 cells

Helicobacter pylori infection has been associated with the development of insulin resistance (IR). This study aimed to examine the effect of H. pylori-derived extracellular vesicles (EVs) on IR induction. EVs were derived from two H. pylori strains, and characterised by transmission electron microscopy and dynamic light scattering. Different concentrations of insulin were added to HepG2 cells to induce IR model. HepG2 cells were exposed to various concentrations of H. pylori-derived EVs to assess IR development. The gene expression of IRS1, AKT2, GLUT2, IL-6, SOCS3, c-Jun and miR-140 was examined using RT-qPCR. Glucose uptake analysis revealed insulin at 5 × 10 -7 mol/l and EVs at 50 µg/ml induced IR model in HepG2 cells. H. pylori-derived EVs downregulated the expression level of IRS1, AKT2, and GLUT2, and upregulated IL-6, SOCS3, c-Jun, and miR-140 expression in HepG2 cells. In conclusion, our findings propose a novel mechanism by which H. pylori-derived EVs could potentially induce IR.

Effects and mechanisms of Helicobacter pylori infection on the occurrence of extra-gastric tumors

Helicobacter pylori (H. pylori) colonizes the human stomach and many studies have discussed the mechanisms of H. pylori infection leading to gastric diseases, including gastric cancer. Additionally, increasing data have shown that the infection of H. pylori may contribute to the development of extra-gastric diseases and tumors. Inflammation, systemic immune responses, microbiome disorders, and hypergastrinemia caused by H. pylori infection are associated with many extra-gastric malignancies. This review highlights recent discoveries; discusses the relationship between H. pylori and various extra-gastric tumors, such as colorectal cancer, lung cancer, cholangiocarcinoma, and gallbladder carcinoma; and explores the mechanisms of extra-gastric carcinogenesis by H. pylori. Overall, these findings refine our understanding of the pathogenic processes of H. pylori, provide guidance for the clinical treatment and management of H. pylori-related extra-gastric tumors, and help improve prognosis.

Beyond the Gut: The intratumoral microbiome's influence on tumorigenesis and treatment response

The intratumoral microbiome (TM) refers to the microorganisms in the tumor tissues, including bacteria, fungi, viruses, and so on, and is distinct from the gut microbiome and circulating microbiota. TM is strongly associated with tumorigenesis, progression, metastasis, and response to therapy. This paper highlights the current status of TM. Tract sources, adjacent normal tissue, circulatory system, and concomitant tumor co-metastasis are the main origin of TM. The advanced techniques in TM analysis are comprehensively summarized. Besides, TM is involved in tumor progression through several mechanisms, including DNA damage, activation of oncogenic signaling pathways (phosphoinositide 3-kinase [PI3K], signal transducer and activator of transcription [STAT], WNT/β-catenin, and extracellular regulated protein kinases [ERK]), influence of cytokines and induce inflammatory responses, and interaction with the tumor microenvironment (anti-tumor immunity, pro-tumor immunity, and microbial-derived metabolites). Moreover, promising directions of TM in tumor therapy include immunotherapy, chemotherapy, radiotherapy, the application of probiotics/prebiotics/synbiotics, fecal microbiome transplantation, engineered microbiota, phage therapy, and oncolytic virus therapy. The inherent challenges of clinical application are also summarized. This review provides a comprehensive landscape for analyzing TM, especially the TM-related mechanisms and TM-based treatment in cancer.

Evaluation of the effect of Helicobacter pylori -derived OMVs and released exosomes from stomach cells treated with OMVs on the expression of genes related to the TGF-β/SMAD signaling pathway in hepatocellular carcinoma

OMVs derived from Helicobacter pylori can lead to cell transformation in gastric epithelium and cancer. Additionally, exosomes (Exos) released by host cells infected with H. pylori can significantly contribute to the development of diseases such as cancer. In this study, the effects of both Exos from AGS cells treated with H. pylori-derived OMVs on the expression of genes related to the TGF-β/SMAD signaling pathway in hepatocellular carcinoma (HCC) cells were investigated. The TGF-β/SMAD pathway is one of the most important pathways that regulate the development and progression of HCC. For this purpose, after treating HepG2 cells with H. pylori-derived OMVs (directly) and Exos from AGS cells treated with H. pylori-derived OMVs (indirectly), the expression levels of TGF-β, SMAD2, SMAD3, SMAD4, and ERK genes were analyzed using Real-time PCR. The findings showed that OMVs derived from H. pylori can significantly increase the expression of genes involved in the TGF-β signaling pathway, which can affect the aggressive behavior of HepG2 cells. Additionally, exosomes secreted from AGS cells or AGS cells treated with OMVs had no effect on changing the expression of the studied genes. Therefore, only the OMVs released from H. pylori can affect the TGF-β/SMAD signaling pathway in HCC cells.

Helicobacter pylori CAs inhibition

Infections from Helicobacter pylori (Hp) are endangering Public Health safety worldwide, due to the associated high risk of developing severe diseases, such as peptic ulcer, gastric cancer, diabetes, and cardiovascular diseases. Current therapies are becoming less effective due to the rise of (multi)drug-resistant phenotypes and an urgent need for new antibacterial agents with innovative mechanisms of action is pressing. Among the most promising pharmacological targets, Carbonic Anhydrases (EC: 4.2.1.1) from Hp, namely HpαCA and HpβCA, emerged for their high druggability and crucial role in the survival of the pathogen in the host. Thereby, in the last decades, the two isoenzymes were isolated and characterized offering the opportunity to profile their kinetics and test different series of inhibitors.

Interaction between intestinal flora and gastric cancer in tumor microenvironment

Gastric Cancer (GC) is a prevalent malignancy globally and is the third leading cause of cancer-related deaths. Recent researches focused on the correlation between intestinal flora and GC. Studies indicate that bacteria can influence the development of gastrointestinal tumors by releasing bacterial extracellular vesicles (BEVs). The Tumor microenvironment (TME) plays an important role in tumor survival, with the interaction between intestinal flora, BEVs, and TME directly impacting tumor progression. Moreover, recent studies have demonstrated that intestinal microflora and BEVs can modify TME to enhance the effectiveness of antitumor drugs. This review article provides an overview and comparison of the biological targets through which the intestinal microbiome regulates TME, laying the groundwork for potential applications in tumor diagnosis, treatment, and prognosis.

Immunomodulatory properties of Bacillus subtilis extracellular vesicles on rainbow trout intestinal cells and splenic leukocytes

Extracellular vesicles (EVs) are cell-derived membrane-surrounded vesicles that carry bioactive molecules. Among EVs, outer membrane vesicles (OMVs), specifically produced by Gram-negative bacteria, have been extensively characterized and their potential as vaccines, adjuvants or immunotherapeutic agents, broadly explored in mammals. Nonetheless, Gram-positive bacteria can also produce bilayered spherical structures from 20 to 400 nm involved in pathogenesis, antibiotic resistance, nutrient uptake and nucleic acid transfer. However, information regarding their immunomodulatory potential is very scarce, both in mammals and fish. In the current study, we have produced EVs from the Gram-positive probiotic Bacillus subtilis and evaluated their immunomodulatory capacities using a rainbow trout intestinal epithelial cell line (RTgutGC) and splenic leukocytes. B. subtilis EVs significantly up-regulated the transcription of several pro-inflammatory and antimicrobial genes in both RTgutGC cells and splenocytes, while also up-regulating many genes associated with B cell differentiation in the later. In concordance, B. subtilis EVs increased the number of IgM-secreting cells in splenocyte cultures, while at the same time increased the MHC II surface levels and antigen-processing capacities of splenic IgM+ B cells. Interestingly, some of these experiments were repeated comparing the effects of B. subtilis EVs to EVs obtained from another Bacillus species, Bacillus megaterium, identifying important differences. The data presented provides evidence of the immunomodulatory capacities of Gram-positive EVs, pointing to the potential of B. subtilis EVs as adjuvants or immunostimulants for aquaculture.

The modulatory effect of Lactobacillus gasseri ATCC 33323 on autophagy induced by extracellular vesicles of Helicobacter pylori in gastric epithelial cells in vitro

Helicobacter pylori has been recognized as a true pathogen, which is associated with various gastroduodenal diseases, and gastric adenocarcinoma. The crosstalk between H. pylori virulence factors and host autophagy remains challenging. H. pylori can produce extracellular vesicles (EVs) that contribute to gastric inflammation and malignancy. Some probiotic strains have been documented to modulate cell autophagy process. This study was aimed to investigate the modulatory effect of cell-free supernatant (CFS) obtained from Lactobacillus gasseri ATCC 33323 on autophagy induced by H. pylori-derived EVs. EVs were isolated from two clinical H. pylori strains (BY-1 and OC824), and characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The viability of AGS cells was assessed after exposure to different concentrations of H. pylori EVs, and L. gasseri CFS. Based on MTT assay and Annexin V-FITC/PI staining, 50 μg/ml of H. pylori EVs and 10 % v/v of L. gasseri CFS were used for further cell treatment experiments. Autophagy was examined using acridin orange (AO) staining, RT-qPCR analysis for autophagy mediators (LC3B, ATG5, ATG12, ATG16L1, BECN1, MTOR, and NOD1), and western blotting for LC3B expression. H. pylori EVs were detected to range in size from 50 to 200 nm. EVs of both H. pylori strains and L. gasseri CFS showed no significant effect on cell viability as compared to untreated cells. H. pylori EVs promoted the development of acidic vesicular organelles and the expression of autophagy-related genes (LC3B, ATG5, ATG12, ATG16L1, BECN1, and NOD1), and decreased the expression of MTOR in AGS cells at 12 and 24 h time periods. In addition, the production of LC3B was increased following 12 h of treatment in AGS cells. In contrast, L. gasseri CFS effectively inhibited EVs-induced autophagy, as evidenced by reduced acidic vesicular organelle formation and modulation of autophagy markers. Our study indicated that L. gasseri CFS can effectively suppress H. pylori EV-induced autophagy in AGS cells. Further investigations are required to decipher the mechanism of action L. gasseri CFS and its metabolites on autophagy inhibition induced by H. pylori.

Engineered bacterial outer membrane vesicles: a versatile bacteria-based weapon against gastrointestinal tumors

Outer membrane vesicles (OMVs) are nanoscale lipid bilayer structures released by gram-negative bacteria. They share membrane composition and properties with their originating cells, making them adept at traversing cellular barriers. These OMVs have demonstrated exceptional membrane stability, immunogenicity, safety, penetration, and tumor-targeting properties, which have been leveraged in developing vaccines and drug delivery systems. Recent research efforts have focused on engineering OMVs to increase production yield, reduce cytotoxicity, and improve the safety and efficacy of treatment. Notably, gastrointestinal (GI) tumors have proven resistant to several traditional oncological treatment strategies, including chemotherapy, radiotherapy, and targeted therapy. Although immune checkpoint inhibitors have demonstrated efficacy in some patients, their usage as monotherapy remains limited by tumor heterogeneity and individual variability. The immunogenic and modifiable nature of OMVs makes them an ideal design platform for the individualized treatment of GI tumors. OMV-based therapy enables combination therapy and optimization of anti-tumor effects. This review comprehensively summarizes recent advances in OMV engineering for GI tumor therapy and discusses the challenges in the clinical translation of emerging OMV-based anti-tumor therapies.

AUF1-mediated inhibition of autophagic lysosomal degradation contributes to CagA stability and Helicobacter pylori-induced inflammation

CagA, a virulence factor of Helicobacter pylori (H. pylori), is known to drive inflammation in gastric epithelial cells and is typically degraded through autophagy. However, the molecular mechanism by which CagA evades autophagy-mediated degradation remains elusive. This study found that H. pylori inhibits autophagic flux by upregulating the expression of AU-rich element RNA-binding factor 1 (AUF1). We confirmed that AUF1 does not affect autophagy initiation but instead hampers lysosomal clearance, as evidenced by treatments with 3-MA, CQ and BafA1. Upregulated AUF1 stabilizes CagA protein levels by inhibiting the autolysosomal degradation of intracellular CagA in H. pylori-infected gastric epithelial cells. Knocking down AUF1 promotes CagA degradation, an effect that can be reversed by the lysosome inhibitor BafA1 and CQ. Transcriptome analysis of AUF1-knockdown gastric epithelial cells infected with H. pylori indicated that AUF1 regulates the expression of lysosomal-associated hydrolase genes, specifically CTSD, to inhibit autolysosomal degradation. Moreover, we observed that knockdown of AUF1 enhanced the stability of CTSD mRNA and identified AUF1 binding to the 3'UTR region of CTSD mRNA. AUF1-mediated downregulation of CTSD expression contributes to CagA stability, and AUF1 overexpression leads to an increase in CagA levels in exosomes, thus promoting extracellular inflammation. In clinical gastric mucosa, the expression of AUF1 and its cytoplasmic translocation are associated with H. pylori-associated gastritis, with CagA being necessary for the translocation of AUF1 into the cytoplasm. Our findings suggest that AUF1 is a novel host-positive regulator of CagA, and dysregulation of AUF1 expression increases the risk of H. pylori-associated gastritis.

Bacterial Outer Membrane Vesicles: Role in Pathogenesis and Host-Cell Interactions

Outer membrane vesicles (OMVs) are small, spherical structures released from the outer membranes of Gram-negative bacteria into the surrounding environment. Investigations into OMVs range from their biogenesis and cargo composition to their ability to transfer virulence factors and modulate host immune responses. This emerging understanding of OMVs has unveiled their pivotal role in the pathogenicity of infectious diseases, shedding light on their interactions with host cells, their contributions to inflammation, their potential involvement in antimicrobial resistance, and their promising use for the development of novel treatments and therapies. Numerous studies have associated the OMVs of pathogenic bacteria with the exacerbation of inflammatory diseases, underlining the significance of understanding the mechanisms associated with these vesicles to find alternatives for combating these conditions. Additionally, OMVs possess the ability to act as decoys, absorbing and neutralizing antibiotics, which significantly diminishes the efficacy of a broad spectrum of antimicrobial agents. Another subtopic of interest is OMVs produced by commensal microbiota. These vesicles are increasingly acknowledged for their mutualistic functions, significantly influencing their host's physiology and immune responses. Consequently, OMVs play a crucial role in maintaining a balanced gut microbiota by fostering symbiotic relationships that significantly contribute to the overall health and well-being of the host. This comprehensive review aims to provide an up-to-date review of OMVs derived from Gram-negative bacteria, summarizing current research findings, and elucidating the multifaceted role of these vesicles in diverse biological contexts.

An update: is there a relationship between H. pylori infection and nonalcoholic fatty liver disease? why is this subject of interest?

Helicobacter pylori (H. pylori) infection is thought to impact various extragastric diseases, including nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease. Meanwhile, the pathogenesis of NAFLD needs further research, and effective treatment for this disease remains elusive. In this mini-review, we enumerate and ponder on the evidence demonstrating an association between H. pylori infection and NAFLD. Primarily, we delve into high-quality meta-analyses and clinical randomized controlled trials focusing on the association studies between the two. We also discuss clinical studies that present opposite conclusions. In addition, we propose a mechanism through which H. pylori infection aggravates NAFLD: inflammatory cytokines and adipocytokines, insulin resistance, lipid metabolism, intestinal barrier and microbiota, H. pylori outer membrane vesicles and H. pylori-infected cell-extracellular vesicles. This mini-review aims to further explore NAFLD pathogenesis and extragastric disease mechanisms caused by H. pylori infection.

The proteomics analysis of extracellular vesicles revealed the possible function of heat shock protein 60 in Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) infection is a major risk factor for gastric diseases, including gastritis and gastric cancer. Heat shock protein 60 (HSP60) is a chaperone protein involved in various cellular processes and has been implicated in the immune response to bacterial infections. Extracellular vesicles (EVs) containing various protein components play important roles in cell communication. In the present study, a systematic proteomic analysis of EVs obtained from H. pylori infected cells was performed and the EV-derived HSP60 function was studied.

METHODS

EVs were evaluated by nanoparticle tracking analysis, transmission electron microscopy and western blotting. The recognized protein components were quantified by label-free proteomics and subjected to bioinformatics assays. The expression of HSP60 in EVs, host cells and gastric cancers infected by H. pylori was determined by western blotting and immunohistochemical, respectively. In addition, the apoptotic regulation mechanisms of HSP60 in H. pylori infection were analyzed by western blotting and flow cytometry.

RESULTS

A total of 120 important differential proteins were identified in the EVs from H. pylori-infected cells and subjected to Gene Ontology analysis. Among them, CD63, HSP-70 and TSG101 were verified via western blotting. Moreover, HSP60 expression was significantly increased in the EVs from H. pylori-infected GES-1 cells. H. pylori infection promoted an abnormal increase in HSP60 expression in GES-1 cells, AGS cells, gastric mucosa and gastric cancer. In addition, knockdown of HSP60 suppressed the apoptosis of infected cells and the expression of Bcl2, and promoted the upregulation of Bax.

CONCLUSION

This study provides a comprehensive proteomic profile of EVs from H. pylori-infected cells, shedding light on the potential role of HSP60 in H. pylori infection. The findings underscore the significance of EV-derived HSP60 in the pathophysiology of H. pylori-associated diseases.

Extracellular vesicles as a novel mediator of interkingdom communication

Extracellular vesicles (EVs) are nanosized lipid bilayer-delimited particles secreted from almost all types of cells including bacteria, mammals and plants, and are presumed to be mediators of intercellular communication. Bacterial extracellular vesicles (BEVs) are nanoparticles with diverse diameters, ranging from 20 to 400 nm. BEVs are composed of soluble microbial metabolites, including nucleic acid, proteins, lipoglycans, and short-chain fatty acids (SCFAs). In addition, EVs may contain quorum sensing peptides that are endowed with the ability to protect bacteria against bacteriophages, form and maintain bacterial communities, and modulate the host immune system. BEVs are potentially promising therapeutic modalities for use in vaccine development, cancer immunotherapy regimens, and drug delivery cargos. Plant-derived EVs (PEVs), such as EVs derived from herbal medicines, can be absorbed by the gut microbiota and influence the composition and homeostasis of gut microbiota. This review highlights the roles of BEVs and PEVs in bacterial and plant physiology and discusses crosstalk among gut bacteria, host metabolism and herbal medicine. In summary, EVs represent crucial communication messengers in the gut microbiota, with potential therapeutic value in the delivery of herbal medicines.

Bacterial Membrane Vesicles: Physiological Roles, Infection Immunology, and Applications

Bacterial or fungal membrane vesicles, traditionally considered as microbial metabolic wastes, are secreted mainly from the outer membrane or cell membrane of microorganisms. However, recent studies have shown that these vesicles play essential roles in direct or indirect communications among microorganisms and between microorganisms and hosts. This review aims to provide an updated understanding of the physiological functions and emerging applications of bacterial membrane vesicles, with a focus on their biogenesis, mechanisms of adsorption and invasion into host cells, immune stimulatory effects, and roles in the much-concerned problem of bacterial resistance. Additionally, the potential applications of these vesicles as biomarkers, vaccine candidates, and drug delivery platforms are discussed.

To eat or not to eat mitochondria? How do host cells cope with mitophagy upon bacterial infection?

Mitochondria fulfil a plethora of cellular functions ranging from energy production to regulation of inflammation and cell death control. The fundamental role of mitochondria makes them a target of choice for invading pathogens, with either an intracellular or extracellular lifestyle. Indeed, the modulation of mitochondrial functions by several bacterial pathogens has been shown to be beneficial for bacterial survival inside their host. However, so far, relatively little is known about the importance of mitochondrial recycling and degradation pathways through mitophagy in the outcome (success or failure) of bacterial infection. On the one hand, mitophagy could be considered as a defensive response triggered by the host upon infection to maintain mitochondrial homeostasis. However, on the other hand, the pathogen itself may initiate the host mitophagy to escape from mitochondrial-mediated inflammation or antibacterial oxidative stress. In this review, we will discuss the diversity of various mechanisms of mitophagy in a general context, as well as what is currently known about the different bacterial pathogens that have developed strategies to manipulate the host mitophagy.

The role and mechanisms of gram-negative bacterial outer membrane vesicles in inflammatory diseases

Outer membrane vesicles (OMVs) are spherical, bilayered, and nanosized membrane vesicles that are secreted from gram-negative bacteria. OMVs play a pivotal role in delivering lipopolysaccharide, proteins and other virulence factors to target cells. Multiple studies have found that OMVs participate in various inflammatory diseases, including periodontal disease, gastrointestinal inflammation, pulmonary inflammation and sepsis, by triggering pattern recognition receptors, activating inflammasomes and inducing mitochondrial dysfunction. OMVs also affect inflammation in distant organs or tissues via long-distance cargo transport in various diseases, including atherosclerosis and Alzheimer's disease. In this review, we primarily summarize the role of OMVs in inflammatory diseases, describe the mechanism through which OMVs participate in inflammatory signal cascades, and discuss the effects of OMVs on pathogenic processes in distant organs or tissues with the aim of providing novel insights into the role and mechanism of OMVs in inflammatory diseases and the prevention and treatment of OMV-mediated inflammatory diseases.

Role of the gut microbiota in anticancer therapy: from molecular mechanisms to clinical applications

In the past period, due to the rapid development of next-generation sequencing technology, accumulating evidence has clarified the complex role of the human microbiota in the development of cancer and the therapeutic response. More importantly, available evidence seems to indicate that modulating the composition of the gut microbiota to improve the efficacy of anti-cancer drugs may be feasible. However, intricate complexities exist, and a deep and comprehensive understanding of how the human microbiota interacts with cancer is critical to realize its full potential in cancer treatment. The purpose of this review is to summarize the initial clues on molecular mechanisms regarding the mutual effects between the gut microbiota and cancer development, and to highlight the relationship between gut microbes and the efficacy of immunotherapy, chemotherapy, radiation therapy and cancer surgery, which may provide insights into the formulation of individualized therapeutic strategies for cancer management. In addition, the current and emerging microbial interventions for cancer therapy as well as their clinical applications are summarized. Although many challenges remain for now, the great importance and full potential of the gut microbiota cannot be overstated for the development of individualized anti-cancer strategies, and it is necessary to explore a holistic approach that incorporates microbial modulation therapy in cancer.

Interactions between extracellular vesicles and microbiome in human diseases: New therapeutic opportunities

In recent decades, accumulating research on the interactions between microbiome homeostasis and host health has broadened new frontiers in delineating the molecular mechanisms of disease pathogenesis and developing novel therapeutic strategies. By transporting proteins, nucleic acids, lipids, and metabolites in their versatile bioactive molecules, extracellular vesicles (EVs), natural bioactive cell-secreted nanoparticles, may be key mediators of microbiota-host communications. In addition to their positive and negative roles in diverse physiological and pathological processes, there is considerable evidence to implicate EVs secreted by bacteria (bacterial EVs [BEVs]) in the onset and progression of various diseases, including gastrointestinal, respiratory, dermatological, neurological, and musculoskeletal diseases, as well as in cancer. Moreover, an increasing number of studies have explored BEV-based platforms to design novel biomedical diagnostic and therapeutic strategies. Hence, in this review, we highlight the recent advances in BEV biogenesis, composition, biofunctions, and their potential involvement in disease pathologies. Furthermore, we introduce the current and emerging clinical applications of BEVs in diagnostic analytics, vaccine design, and novel therapeutic development.

The Influence of Helicobacter pylori on Human Gastric and Gut Microbiota

Helicobacter pylori is a Gram-negative bacterium that is able to colonize the human stomach, whose high prevalence has a major impact on human health, due to its association with several gastric and extra-gastric disorders, including gastric cancer. The gastric microenvironment is deeply affected by H. pylori colonization, with consequent effects on the gastrointestinal microbiota, exerted via the regulation of various factors, including gastric acidity, host immune responses, antimicrobial peptides, and virulence factors. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Notably, therapy regimens integrated with probiotics have been shown to reduce the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. In light of the deep impact of gut microbiota alterations on human health, the present article aims to provide an overview of the complex interaction between H. pylori and the gastrointestinal microbiota, focusing also on the consequences of eradication therapies and the effects of probiotic supplementation.

Glycyrrhizin, an inhibitor of HMGB1 induces autolysosomal degradation function and inhibits Helicobacter pylori infection

BACKGROUND

Helicobacter pylori is a key agent for causing gastric complications linked with gastric disorders. In response to infection, host cells stimulate autophagy to maintain cellular homeostasis. However, H. pylori have evolved the ability to usurp the host's autophagic machinery. High mobility group box1 (HMGB1), an alarmin molecule is a regulator of autophagy and its expression is augmented during infection and gastric cancer. Therefore, this study aims to explore the role of glycyrrhizin (a known inhibitor of HMGB1) in autophagy during H. pylori infection.

MAIN METHODS

Human gastric cancer (AGS) cells were infected with the H. pylori SS1 strain and further treatment was done with glycyrrhizin. Western blot was used to examine the expression of autophagy proteins. Autophagy and lysosomal activity were monitored by fluorescence assays. A knockdown of HMGB1 was performed to verify the effect of glycyrrhizin. H. pylori infection in in vivo mice model was established and the effect of glycyrrhizin treatment was studied.

RESULTS

The autophagy-lysosomal pathway was impaired due to an increase in lysosomal membrane permeabilization during H. pylori infection in AGS cells. Subsequently, glycyrrhizin treatment restored the lysosomal membrane integrity. The recovered lysosomal function enhanced autolysosome formation and concomitantly attenuated the intracellular H. pylori growth by eliminating the pathogenic niche. Additionally, glycyrrhizin treatment inhibited inflammation and improved gastric tissue damage in mice.

CONCLUSION

This study showed that inhibiting HMGB1 restored lysosomal activity to ameliorate H. pylori infection. It also demonstrated the potential of glycyrrhizin as an antibacterial agent to address the problem of antimicrobial resistance.

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.

Extracellular Vesicles from Campylobacter jejuni CDT-Treated Caco-2 Cells Inhibit Proliferation of Tumour Intestinal Caco-2 Cells and Myeloid U937 Cells: Detailing the Global Cell Response for Potential Application in Anti-Tumour Strategies

Cytolethal distending toxin (CDT) is produced by a range of Gram-negative pathogenic bacteria such as Campylobacter jejuni. CDT represents an important virulence factor that is a heterotrimeric complex composed of CdtA, CdtB, and CdtC. CdtA and CdtC constitute regulatory subunits whilst CdtB acts as the catalytic subunit exhibiting phosphatase and DNase activities, resulting in cell cycle arrest and cell death. Extracellular vesicle (EV) secretion is an evolutionarily conserved process that is present throughout all kingdoms. Mammalian EVs play important roles in regular cell-to-cell communications but can also spread pathogen- and host-derived molecules during infections to alter immune responses. Here, we demonstrate that CDT targets the endo-lysosomal compartment, partially evading lysosomal degradation and exploiting unconventional secretion (EV release), which is largely involved in bacterial infections. CDT-like effects are transferred by Caco-2 cells to uninfected heterologous U937 and homologous Caco-2 cells. The journey of EVs derived from CDT-treated Caco-2 cells is associated with both intestinal and myeloid tumour cells. EV release represents the primary route of CDT dissemination, revealing an active toxin as part of the cargo. We demonstrated that bacterial toxins could represent suitable tools in cancer therapy, highlighting both the benefits and limitations. The global cell response involves a moderate induction of apoptosis and autophagic features may play a protective role against toxin-induced cell death. EVs from CDT-treated Caco-2 cells represent reliable CDT carriers, potentially suitable in colorectal cancer treatments. Our data present a potential bacterial-related biotherapeutic supporting a multidrug anticancer protocol.

Membrane Vesicles Derived from Gut Microbiota and Probiotics: Cutting-Edge Therapeutic Approaches for Multidrug-Resistant Superbugs Linked to Neurological Anomalies

Multidrug-resistant (MDR) superbugs can breach the blood-brain barrier (BBB), leading to a continuous barrage of pro-inflammatory modulators and induction of severe infection-related pathologies, including meningitis and brain abscess. Both broad-spectrum or species-specific antibiotics (β-lactamase inhibitors, polymyxins, vancomycin, meropenem, plazomicin, and sarecycline) and biocompatible poly (lactic-co-glycolic acid) (PLGA) nanoparticles have been used to treat these infections. However, new therapeutic platforms with a broad impact that do not exert off-target deleterious effects are needed. Membrane vesicles or extracellular vesicles (EVs) are lipid bilayer-enclosed particles with therapeutic potential owing to their ability to circumvent BBB constraints. Bacteria-derived EVs (bEVs) from gut microbiota are efficient transporters that can penetrate the central nervous system. In fact, bEVs can be remodeled via surface modification and CRISPR/Cas editing and, thus, represent a novel platform for conferring protection against infections breaching the BBB. Here, we discuss the latest scientific research related to gut microbiota- and probiotic-derived bEVs, and their therapeutic modifications, in terms of regulating neurotransmitters and inhibiting quorum sensing, for the treatment of neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases. We also emphasize the benefits of probiotic-derived bEVs to human health and propose a novel direction for the development of innovative heterologous expression systems to combat BBB-crossing pathogens.

Extracellular vesicles from gastric epithelial GES-1 cells infected with Helicobacter pylori promote changes in recipient cells associated with malignancy

Chronic Helicobacter pylori (H. pylori) infection is considered the main risk factor for the development of gastric cancer. Pathophysiological changes in the gastric mucosa initiated by this bacterium can persist even after pharmacological eradication and are likely attributable also to changes induced in non-infected cells as a consequence of intercellular communication via extracellular vesicles (EVs). To better understand what such changes might entail, we isolated EVs from immortalized normal gastric GES-1 cells infected (EVHp+) or not with H. pylori (EVHp-) by ultracentrifugation and characterized them. Infection of GES-1 cells with H. pylori significantly increased the release of EVs and slightly decreased the EV mean size. Incubation with EVHp+ for 24 h decreased the viability of GES-1 cells, but increased the levels of IL-23 in GES-1 cells, as well as the migration of GES-1 and gastric cancer AGS cells. Furthermore, incubation of GES-1 and AGS cells with EVHp+, but not with EVHp-, promoted cell invasion and trans-endothelial migration in vitro. Moreover, stimulation of endothelial EA.hy926 cells for 16 h with EVHp+ promoted the formation of linked networks. Finally, analysis by mass spectrometry identified proteins uniquely present and others enriched in EVHp+ compared to EVHp-, several of which are known targets of hypoxia induced factor-1α (HIF-1α) that may promote the acquisition of traits important for the genesis/progression of gastric pre-neoplastic changes associated with H. pylori infection. In conclusion, the harmful effects of H. pylori infection associated with the development of gastric malignancies may spread via EVs to non-infected areas in the early and later stages of gastric carcinogenesis.

Effects of Helicobacter pylori Infection on Ghrelin and Insulin-like Growth Factor 1 Secretion in Children with Idiopathic Short Stature

BACKGROUND

A diagnosis of "idiopathic short stature" (ISS) in a child means that the cause of the disease has not been established, although there are certainly some unknown factors that contributed to its occurrence. Ghrelin and leptin are important in controlling food intake; ghrelin is also a growth hormone (GH) stimulator. Both enterohormones are produced in the stomach and their secretion may be affected by a Helicobacter pylori (H. pylori) infection.

METHODS

Our study included a group of 61 children (53 prepubertal and 8 peripubertal) with ISS, without any gastrointestinal tract symptoms but in whom the histopathological evaluation of stomach tissue was made during gastroscopy to diagnose H. pylori infection. In each child, fasting ghrelin, leptin and IGF-1 concentrations, and GH levels in two stimulation tests were assessed.

RESULTS

H. pylori infection was confirmed in 24.6% of the children. Ghrelin and IGF-1 concentrations were significantly lower in H. pylori-positive than H. pylori-negative children (this was more noticeable in prepubertal subgroups), however there was not a discrepancy in regards to GH concentrations in stimulation tests, leptin levels or the nutritional state between groups.

CONCLUSIONS

Short children, infected by H. pylori seem to have lower ghrelin and IGF-1 concentrations than children without infection, this may be the reason for a worse growth rate in this subgroup.

Bacterial Infections and Atherosclerosis – A Mini Review

Atherosclerosis is the most challenging subsets of coronary artery disease in humans, in which risk factors emerge from childhood, and its prevalence increases with age. Experimental research demonstrates that infections due to bacteria stimulate atherogenic events. Atherosclerosis has complex pathophysiology that is linked with several bacterial infections by damaging the inner arterial wall and heart muscles directly and indirectly by provoking a systemic pro-inflammation and acute-phase protein. Repeated bacterial infections trigger an inflammatory cascade that triggers immunological responses that negatively impact cardiovascular biomarkers includes triglycerides, high-density lipoprotein, C-reactive protein, heat shock proteins, cytokines, fibrinogen, and leukocyte count. Herein, we intended to share the role of bacterial infection in atherosclerosis and evaluate existing evidence of animal and human trials on the association between bacterial infections and atherosclerosis on update.

Intestinal microbiota-derived membrane vesicles and their role in chronic kidney disease

Intestinal microbiota-derived membrane vesicles (MVs) play essential roles in immunomodulation and maintenance of the intestinal micro-ecosystem. The relationship between MVs and chronic kidney disease (CKD) has remained undefined. This review provides a survey of the structure and biological function of different vesicle types and summarizes the possible pathogenic mechanisms mediated by MVs, which may be of great clinical significance in the diagnosis and treatment of chronic kidney disease.

Extracellular vesicles from helicobacter pylori-infected cells and helicobacter pylori outer membrane vesicles in atherosclerosis

BACKGROUND

The role of H. pylori infection has been reported in various extragastric diseases, particularly, the correlation between H. pylori and atherosclerosis (AS) have received lots of attention. Some scholars demonstrated that the presence of H. pylori-specific DNA in the sclerotic plaques of atheromatous patients provides biological evidences, with indicating that H. pylori infection is a potential factor of AS. However, the underlying mechanism of H. pylori or their products cross the epithelial barriers to enter the blood circulation remains unclear. Recent studies have shown that the extracellular vesicles (EVs) derived from H. pylori-infected gastric epithelial cells encapsulated H. pylori virulence factor cytotoxin-associated gene A (CagA) and existed in the blood samples of patients or mice, which indicating that they can carry CagA into the blood circulation. Based on these findings, some researchers proposed a hypothesis that H. pylori is involved in the pathogenesis of AS via EVs-based mechanisms. In addition, outer membrane vesicles (OMVs) serve as transport vehicles to deliver H. pylori virulence factors to epithelial cells. It is necessary to discuss the role of H. pylori OMVs in the development of AS.

OBJECTIVES

This review will focus on the correlation between H. pylori infection and AS and tried to unveil the possible role of EVs from H. pylori-infected cells and H. pylori OMVs in the pathogenesis of AS, with a view to providing help in refining our knowledge in this aspect.

METHODS

All of information included in this review was retrieved from published studies on H. pylori infection in AS.

RESULTS

H. pylori infection may be an atherosclerotic risk factor and drives researchers to reevaluate the role of H. pylori in the pathogenesis of AS. Some findings proposed a new hypothesis that H. pylori may be involved in the pathogenesis of AS through EVs-based mechanisms. Besides EVs from H. pylori-infected cells, whether H. pylori OMVs may play some role in the pathogenesis of AS is still remain unclear.

CONCLUSION

Existing epidemiological and clinical evidence had shown that there is a possible association between H. pylori and AS. However, except for the larger randomized controlled trials, more basic research about EVs from H. pylori-infected cells and H. pylori OMVs is the need of the hour to unveil the possible role of H. pylori infection in the pathogenesis of AS.

Immunological Perspective: Helicobacter pylori Infection and Gastritis

Helicobacter pylori is a spiral-shaped gram-negative bacterium. Its infection is mainly transmitted via oral-oral and fecal-oral routes usually during early childhood. It can achieve persistent colonization by manipulating the host immune responses, which also causes mucosal damage and inflammation. H. pylori gastritis is an infectious disease and results in chronic gastritis of different severity in near all patients with infection. It may develop from acute/chronic inflammation, chronic atrophic gastritis, intestinal metaplasia, dysplasia, and intraepithelial neoplasia, eventually to gastric cancer. This review attempts to cover recent studies which provide important insights into how H. pylori causes chronic inflammation and what the characteristic is, which will immunologically explain H. pylori gastritis.

MicroRNAs Encoded by Virus and Small RNAs Encoded by Bacteria Associated with Oncogenic Processes

Cancer is a deadly disease and, globally, represents the second leading cause of death in the world. Although it is a disease where several factors can help its development, virus induced infections have been associated with different types of neoplasms. However, in bacterial infections, their participation is not known for certain. Among the proposed approaches to oncogenesis risks in different infections are microRNAs (miRNAs). These are small molecules composed of RNA with a length of 22 nucleotides capable of regulating gene expression by directing protein complexes that suppress the untranslated region of mRNA. These miRNAs and other recently described, such as small RNAs (sRNAs), are deregulated in the development of cancer, becoming promising biomarkers. Thus, resulting in a study possibility, searching for new tools with diagnostic and therapeutic approaches to multiple oncological diseases, as miRNAs and sRNAs are main players of gene expression and host–infectious agent interaction. Moreover, sRNAs with limited complementarity are similar to eukaryotic miRNAs in their ability to modulate the activity and stability of multiple mRNAs. Here, we will describe the regulatory RNAs from viruses that have been associated with cancer and how sRNAs in bacteria can be related to this disease.