EpCAM-dependent extracellular vesicles from intestinal epithelial cells maintain intestinal tract immune balance

Microscopic messengers: Extracellular vesicles shaping gastrointestinal health and disease

The field of extracellular vesicles (EVs) is advancing rapidly, and this review aims to synthesize the latest research connected to EVs and the gastrointestinal tract. We will address new and emerging roles for EVs derived from internal sources such as the pancreas and immune system and how these miniature messengers alter organismal health or the inflammatory response within the GI tract. We will examine what is known about external EVs from dietary and bacterial sources and the immense anti-inflammatory, immune-modulatory, and proliferative potential within these nano-sized information carriers. EV interactions with the intestinal and colonic epithelium and associated immune cells at homeostatic and disease states, such as necrotizing enterocolitis (NEC) and inflammatory bowel disease (IBD) will also be covered. We will discuss how EVs are being leveraged as therapeutics or for drug delivery and conclude with a series of unanswered questions in the field.

Biological roles and clinical applications of EpCAM in HCC

Epithelial cell adhesion molecule (EpCAM) is an important biomarker in tumors. In hepatocellular carcinoma (HCC), EpCAM + cells exhibit high invasiveness, tumorigenic ability, therapeutic resistance, and self-renewal ability, often identified as liver cancer stem cells (CSCs). Detecting EpCAM + cells in tumor lesions and circulation is valuable for predicting patient prognosis and monitoring therapeutic outcomes, emphasizing its clinical significance. Given its broad expression in HCC, especially in CSCs and circulating tumor cells (CTCs), EpCAM-targeting agents have garnered substantial research interest. However, the role of EpCAM in HCC progression and its regulatory mechanisms remains poorly understood. Furthermore, clinical applications of EpCAM, such as liquid biopsy and targeted therapies, are still controversial. This review summarizes the biological properties of EpCAM + HCC cells, explores the regulatory mechanisms governing EpCAM expression, and discusses its clinical significance of using EpCAM as a prognostic marker and therapeutic target.

Extracellular vesicles and preterm infant diseases

With the continuous improvement in perinatal care, the number of viable preterm infants is gradually increasing, along with the rise in preterm-related diseases such as necrotizing enterocolitis, bronchopulmonary dysplasia, perinatal brain injury, retinopathy of prematurity, and sepsis. Due to the unique pathophysiology of preterm infants, diagnosing and treating these diseases has become particularly challenging, significantly affecting their survival rate and long-term quality of life. Extracellular vesicles (EVs), as key mediators of intercellular communication, play an important regulatory role in the pathophysiology of these diseases. Because of their biological characteristics, EVs could serve as biomarkers and potential therapeutic agents for preterm-related diseases. This review summarizes the biological properties of EVs, their relationship with preterm-related diseases, and their prospects for diagnosis and treatment. EVs face unique challenges and opportunities for clinical applications.

Qingchang suppository ameliorates mucosal inflammation in ulcerative colitis by inhibiting the differentiation and effector functions of Th1 and Th17 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Qing Chang Suppository (QCS), a traditional Chinese medicine formula, has been shown to effectively alleviate mucosal inflammation in patients with ulcerative colitis (UC). While the mechanism of QCS appears to be related to the regulation of CD4+T cell subset responses, direct evidence demonstrating that QCS inhibits Th1 and Th17 cell activation in UC (particularly based on human data) remains lacking. Additionally, the precise mechanisms through which QCS affects these cells have yet to be fully elucidated.

AIM OF STUDY

This study aimed to investigate the effects of QCS on Th1 and Th17 cell responses in UC and to explore the underlying mechanisms.

MATERIALS AND METHODS

Twenty-eight patients with mild-to-moderate UC were recruited and treated with QCS for 12 weeks. Symptoms were assessed every two weeks, with sigmoidoscopies performed at baseline and at week 12. Intestinal mucosal biopsies and peripheral blood (PB) were collected at these time points. At the end of the trial, patients were categorized into responder and non-responder groups based on a modified Mayo disease activity index score. Healthy controls (HCs) were defined as subjects without IBD or colorectal carcinoma but with colon polyps. The frequencies of IFN-γ+CD4+T cells and IL-17A+CD4+T cells in PB and colonic mucosa were measured using flow cytometry. The expression levels and localization of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A were determined via immunofluorescence, and JNK signaling activation was assessed through immunoblotting and immunohistochemistry. All parameters were compared across the three groups.

RESULTS

At week 12, responders showed a significant reduction in colonic mucosal inflammation compared to baseline, accompanied by decreased frequencies of IFN-γ+CD4+T and IL-17A+CD4+ T cells in both PB and the colonic epithelial layer. Notably, Th1 and Th17 cell activity around intestinal epithelial cells (IECs) was nearly undetectable, as evidenced by the diminished expression of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A. Additionally, JNK phosphorylation in these cells was significantly reduced. In contrast, non-responders exhibited no meaningful improvement; colonic pathology remained unchanged, and elevated levels of IFN-γ+CD4+T and IL-17A+CD 4+T cells persisted in both the PB and colonic epithelial layer. The presence of Th1 and Th17 cells and their associated cytokines around IECs remained substantial, and there was no significant change in JNK activation.

CONCLUSION

QCS attenuates mucosal inflammation in UC patients by inhibiting the differentiation and effector functions of Th1 and Th17 cells, primarily through the regulation of the JNK signaling pathway.

Therapeutic potential of human breast milk-derived exosomes in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe inflammatory and necrotizing disease of the intestine that primarily affects the neonates, particularly premature infants. It has a high incidence of approximately 8.9% in extremely preterm infants, with a mortality rate ranging from 20 to 30%. In recent years, exosomes, particularly those derived from breast milk, have emerged as potential candidates for NEC therapy. Human breast milk-derived exosomes (BME) have been shown to enhance intestinal barrier function, protect intestinal epithelial cells from oxidative stress, promote the proliferation and migration of intestinal epithelial cells, and reduce the severity of experimental NEC models. As a subset of extracellular vesicles, BME possess the membrane structure, low immunogenicity, and high permeability, making them ideal vehicles for the treatment of NEC. Additionally, exosomes derived from various sources, including stem cells, intestinal epithelial cells, plants, and bacteria, have been implicated in the development and protection of intestinal diseases. This article summarizes the mechanisms through which exosomes, particularly BME, exert their effects on NEC and discusses the feasibility and obstacles associated with this novel therapeutic strategy.

Knockout of neutrophil cytosolic factor 1 ameliorates neuroinflammation and motor deficit after traumatic brain injury

Traumatic brain injury (TBI) is a predominant cause of long-term disability in adults, yet the molecular mechanisms underpinning the neuropathological processes associated with it remain inadequately understood. Neutrophil cytosolic factor 1 (NCF1, also known as p47phox) is one of the cytosolic components of NADPH oxidase NOX2. In this study, we observed a reduction in the volume of TBI-induced brain lesions in NCF1-knockout mice compared to controls. Correspondingly, the neuronal loss induced by TBI was mitigated in the NCF1-knockout mice. Behavioral analysis also demonstrated that the motor coordination deficit following TBI was mitigated by the depletion of NCF1. Mechanistically, our findings revealed that NCF1 deficiency attenuated TBI-induced inflammatory responses by inhibiting the release of proinflammatory factors and reducing neutrophil infiltration into the brain parenchyma. Additionally, our results indicated that NCF1 deficiency significantly decreased the levels of reactive oxygen species in neutrophils. Taken together, our findings indicate that NCF1 plays a crucial role in the regulation of brain injury and secondary inflammation post-TBI.

Cell-derived biomimetic drug delivery system for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is a chronic recurrent disease with an increasing incidence year by year. At present, no safe and effective treatment for IBD exists. Thus, there is an urgent need to create new therapeutic options that have decreased adverse effects and positive clinical efficacy. A range of nanomaterials have fueled the advancement of nanomedicine in recent years, which is establishing more appealing and prospective treatment approaches for IBD. However, traditional synthetic nanomaterials still have some problems in the IBD drug delivery process, such as weak targeting ability of vectors, difficulty escaping immune surveillance, and poor biosecurity. Natural sources of biological nanomaterials have been identified to solve the above problems. A drug delivery system based on bionic technology is expected to achieve a new breakthrough in the targeted therapy of IBD by nanotechnology due to its organic integration of low immunogenicity and natural targeting of biological materials and the controllability and versatility of synthetic nanocarrier design. We begin this review by outlining the fundamental traits of both inflammatory and healthy intestinal microenvironments. Subsequently, we review the latest application of a cell-derived bionic drug delivery system in IBD therapy. Finally, we discuss the development prospects of this delivery system and challenges to its clinical translation. Biomimetic nanotherapy is believed to offer a new strategy for the treatment of IBD.

Identification of Key Genes in Fetal Gut Development at Single-Cell Level by Exploiting Machine Learning Techniques

The study of fetal gut development is critical due to its substantial influence on immediate neonatal and long-term adult health. Current research largely focuses on microbiome colonization, gut immunity, and barrier function, alongside the impact of external factors on these phenomena. Limited research has been dedicated to the categorization of developing fetal gut cells. Our study aimed to enhance our understanding of fetal gut development by employing advanced machine-learning techniques on single-cell sequencing data. This dataset consisted of 62,849 samples, each characterized by 33,694 distinct gene features. Four feature ranking algorithms were utilized to sort features according to their significance, resulting in four feature lists. Then, these lists were fed into an incremental feature selection method to extract essential genes, classification rules, and build efficient classifiers. Several important genes were recognized by multiple feature ranking algorithms, such as FGG, MDK, RBP1, RBP2, IGFBP7, and SPON2. These features were key in differentiating specific developing intestinal cells, including epithelial, immune, mesenchymal, and vasculature cells of the colon, duo jejunum, and ileum cells. The classification rules showed special gene expression patterns on some intestinal cell types and the efficient classifiers can be useful tools for identifying intestinal cells.

miRNA packaging into small extracellular vesicles and implications in pain

Extracellular vesicles (EVs) are a heterogenous group of lipid bilayer bound particles naturally released by cells. These vesicles are classified based on their biogenesis pathway and diameter. The overlap in size of exosomes generated from the exosomal pathway and macrovesicles that are pinched off from the surface of the plasma membrane makes it challenging to isolate pure populations. Hence, isolated vesicles that are less than 200 nm are called small extracellular vesicles (sEVs). Extracellular vesicles transport a variety of cargo molecules, and multiple mechanisms govern the packaging of cargo into sEVs. Here, we discuss the current understanding of how miRNAs are targeted into sEVs, including the role of RNA binding proteins and EXOmotif sequences present in miRNAs in sEV loading. Several studies in human pain disorders and rodent models of pain have reported alterations in sEV cargo, including miRNAs. The sorting mechanisms and target regulation of miR-939, a miRNA altered in individuals with complex regional pain syndrome, is discussed in the context of inflammation. We also provide a broad overview of the therapeutic strategies being pursued to utilize sEVs in the clinic and the work needed to further our understanding of EVs to successfully deploy sEVs as a pain therapeutic.

Proton pump inhibitors reduce chemotherapeutic hepatotoxicity and enhance hepatic uptake and accumulation of drug-loaded extracellular vesicles

Extracellular vesicles (EVs) are involved in the progression of various diseases. Tumor cell-derived EVs (TEVs) are a particular concern, as they can induce fatty liver by promoting liver macrophages to secrete tumor necrosis factor (TNF), thus enhancing the toxicity of chemotherapy. Therefore, reducing pathogenic EV production is a potential strategy for treating EV-related diseases. However, there are currently no effective clinical reagents to obtain this purpose. In addition, EVs are also natural and ideal drug-delivery vehicles. Improving the delivery efficiency of EVs remains a challenge. Proton pump inhibitors (PPIs) have been demonstrated to promote cell uptake of EVs by inducing micropinocytosis. Here, we show that PPIs can accelerate TEV clearance, reduce TEV uptake by liver macrophages and decrease the mRNA expression of TNF in liver macrophages of tumor-bearing mice. Correspondingly, the fatty liver phenotypes are alleviated, and the tolerance to chemotherapy is improved in these mice. Furthermore, our findings indicate that PPIs facilitate the uptake of red blood cell-derived EVs (RBC-EVs) loaded with antisense oligonucleotides of Trim21 (Trim21-ASOs) by the liver macrophages of obesity. Consequently, the inhibition of macrophage inflammatory responses in obese mice mediated by RBC-EVs/Trim21-ASOs was further enhanced by PPIs, resulting in a more profound improvement in obesity and related metabolic disorders. In conclusion, our findings demonstrated that PPIs can effectively clear pathogenic EVs and enhance the delivery efficacy of EV vehicles, making them a highly promising clinical prospect.

Extracellular vesicles for the treatment of ulcerative colitis: A systematic review and meta-analysis of animal studies

Background

Extracellular vesicles (EVs) are being considered as a potential therapeutic option for ulcerative colitis (UC), and numerous preclinical studies have been conducted on the use of EVs for UC.

Methods

A systematic review was conducted to compare the therapeutic effects of mammalian EVs and placebo on UC in animal models, along with a meta-analysis comparing naïve (unmodified) EVs and placebo. The search was performed in four databases (PubMed, Web of Science, Scopus, and EMBASE) up to September 13th, 2023. The primary outcomes included disease activity index (DAI), colonic mucosal damage index (CMDI), and adverse effects (PROSPERO ID: CRD42023458039).

Results

A total of 69 studies were included based on pre-determined criteria, involving 1271 animals. Of these studies, 51 measured DAI scores, with 98 % reporting that EVs could reduce DAI scores. Additionally, 5 studies reported CMDI and all showed that EVs could significantly reduce CMDI. However, only 3 studies assessed adverse effects and none reported any significant adverse effects. The meta-analysis of these studies (40 studies involving 1065 animals) revealed that naïve EVs could significantly decrease the DAI score (SMD = -3.00; 95 % CI: -3.52 to -2.48) and CMDI (SMD = -2.10; 95 % CI: -2.85 to -1.35).

Conclusion

The results indicate that mammalian EVs have demonstrated therapeutic benefits in animal models of UC; however, the safety profile of EVs remains inadequate which highlights the need for further research on safety outcomes.

Yin-Yang: two sides of extracellular vesicles in inflammatory diseases

The concept of Yin-Yang, originating in ancient Chinese philosophy, symbolizes two opposing but complementary forces or principles found in all aspects of life. This concept can be quite fitting in the context of extracellular vehicles (EVs) and inflammatory diseases. Over the past decades, numerous studies have revealed that EVs can exhibit dual sides, acting as both pro- and anti-inflammatory agents, akin to the concept of Yin-Yang theory (i.e., two sides of a coin). This has enabled EVs to serve as potential indicators of pathogenesis or be manipulated for therapeutic purposes by influencing immune and inflammatory pathways. This review delves into the recent advances in understanding the Yin-Yang sides of EVs and their regulation in specific inflammatory diseases. We shed light on the current prospects of engineering EVs for treating inflammatory conditions. The Yin-Yang principle of EVs bestows upon them great potential as, therapeutic, and preventive agents for inflammatory diseases.

The downregulation of tight junction proteins and pIgR in the colonic epithelium causes the susceptibility of EpCAM+/- mice to colitis and gut microbiota dysbiosis

Background

The genetic factors play important roles on the pathogenesis of inflammatory bowel disease (IBD). EpCAM is highly expressed in the intestinal epithelium. It is still unclear if the decrease or somatic mutation of EpCAM could cause IBD.

Methods

The WT and EpCAM+/- mice were administrated with DSS intermittently for nearly 8 weeks. The colon, liver and feces were harvested to check the morphological and histological changes, the expression of inflammatory genes and the gut microbiota via H&E staining, immunofluorescence, qPCR, western blot and 16S rDNA sequence assays.

Results

The DSS administration induced more serious inflammation in the colon of EpCAM+/- mice than WT mice. Compared to DSS-induced WT mice, the transcriptional levels of IL-6, F4/80, Ly6g, Ly6d and Igha were significantly higher in the colon of DSS-induced EpCAM+/- mice. The protein levels of MMP7 and MMP8 and the activation of JNK, ERK1/2 and p38 were significantly increased in the colon of DSS-induced EpCAM+/- mice. The protein levels of CLDN1, CLDN2, CLDN3, CLDN7, OCLD, ZO-1 and pIgR were significantly decreased in the colon of DSS-induced EpCAM+/- mice. The serum concentration of LPS was significantly higher in the DSS-induced EpCAM+/- mice which caused the acute inflammation in the liver of them. The expression of Pigr was significantly reduced in the liver of DSS-induced EpCAM+/- mice. The ratio of Firmicutes/Bacteroidetes at the phylum level was higher in the gut microbiota of EpCAM+/- mice than WT mice.

Conclusion

In conclusion, the heterozygous mutation of EpCAM increased the susceptibility to colitis, gut microbiota dysbiosis and liver injury.

Three-Dimensional DNA Hydrogel Mediated Dual-Mode Sensing Method for Quantification of Epithelial Cell Adhesion Molecule in Biological Fluid Samples

Monitoring changes in the expression of marker proteins in biological fluids is essential for biomarker-based disease diagnosis. Epithelial cell adhesion molecule (EpCAM) has been identified as a broad-spectrum biomarker for various chronic diseases and as a therapeutic target. However, the development of simple and reliable methods for quantifying EpCAM changes in biological fluids faces challenges due to the variability of its expression across different diseases, the presence of soluble forms, and matrix effects. In this paper, a surface-enhanced Raman scattering (SERS)-fluorescence (FL) dual-mode sensing method was established for quantification of trace EpCAM in biological fluids based on bimetallic Au@Ag nanoparticles and nitrogen-doped quantum dots encapsulated DNA hydrogel hybrid with graphene oxide (Au@Ag-NQDs/GO). The DNA hydrogel was constructed based on three-dimensional (3D) structure DNA-mediated strategy using an aptamer DNA (AptDNA) linker. The interaction of the AptDNA with EpCAM triggered the disassembly of the DNA hydrogel. Consequently, the release of Au@Ag nanoparticles induced an "on-off" switch in the SERS signal while the weakened FL quenching effect in Au@Ag-NQDs/GO system achieved "off-on" switch of FL signal, enabling the simultaneous SERS-FL quantification of EpCAM. The established dual-mode method exhibited outstanding sensitivity and stability in quantifying EpCAM in the range of 0.5-60.0 pg/mL, with the limits of detection (LODs) of SERS and FL as 0.17 and 0.35 pg/mL, respectively. When applied for real sample analysis, the method showed satisfactory specificity and recoveries in cancer cells lysate, serum, and urine samples with RSDs of 2.8-6.3%, 4.0-6.3%, and 2.8-5.7%, respectively. The developed SERS-FL sensing method offered a sensitive, reliable, and practical quantification strategy for trace EpCAM in diverse biological fluid samples, which would benefit the early diagnosis of disease and further health management.

Proteomic Analysis of Caco-2 Cells Disrupted by EcN 1917-Derived OMVs Reveals Molecular Information on Bacteria-Mediated Cancer Cell Migration

Escherichia coli Nissle 1917 (EcN 1917) exhibits distinct tumor-targeting activity, and early studies demonstrated that outer membrane vesicles (OMVs) mediate bacteria-host interactions. To decipher the molecular mechanism underlying the interaction between EcN 1917 and host cells via OMV-mediated communication, we investigated the phenotypic changes in Caco-2 cells perturbed by EcN 1917-derived OMVs and constructed proteomic maps of the EcN 1917-derived OMV components and OMV-perturbed host cells. Our findings revealed that the size of the EcN 1917-derived OMV proteome increased 4-fold. Treatment with EcN 1917-derived OMVs altered the proteomic and phosphoproteomic profiles of host cells. Importantly, for the first time, we found that treatment with EcN 1917-derived OMVs inhibited cancer cell migration by suppressing the expression of ANXA9. In addition, phosphoproteomic data suggested that the ErbB pathway may be involved in OMV-mediated cell migration. Taken together, our study provides valuable data for further investigations of OMV-mediated bacteria-host interactions and offers great insights into the underlying mechanism of probiotic-assisted colorectal cancer therapy.

The science of exosomes: Understanding their formation, capture, and role in cellular communication

Extracellular vesicles (EVs) serve as a crucial method for transferring information among cells, which is vital in multicellular organisms. Among these vesicles, exosomes are notable for their small size, ranging from 20 to 150 nm, and their role in cell-to-cell communication. They carry lipids, proteins, and nucleic acids between cells. The creation of exosomes begins with the inward budding of the cell membrane, which then encapsulates various macromolecules as cargo. Once filled, exosomes are released into the extracellular space and taken up by target cells via endocytosis and similar processes. The composition of exosomal cargo varies, encompassing diverse macromolecules with specific functions. Because of their significant roles, exosomes have been isolated from various cell types, including cancer cells, endothelial cells, macrophages, and mesenchymal cells, with the aim of harnessing them for therapeutic applications. Exosomes influence cellular metabolism, and regulate lipid, glucose, and glutamine pathways. Their role in pathogenesis is determined by their cargo, which can manipulate processes such as apoptosis, proliferation, inflammation, migration, and other molecular pathways in recipient cells. Non-coding RNA transcripts, a common type of cargo, play a pivotal role in regulating disease progression. Exosomes are implicated in numerous biological and pathological processes, including inflammation, cancer, cardiovascular diseases, diabetes, wound healing, and ischemic-reperfusion injury. As a result, they hold significant potential in the treatment of both cancerous and non-cancerous conditions.

Proton pump inhibitors enhance macropinocytosis-mediated extracellular vesicle endocytosis by inducing membrane v-ATPase assembly

Besides participating in diverse pathological and physiological processes, extracellular vesicles (EVs) are also excellent drug-delivery vehicles. However, clinical drugs modulating EV levels are still lacking. Here, we show that proton pump inhibitors (PPIs) reduce EVs by enhancing macropinocytosis-mediated EV uptake. PPIs accelerate intestinal cell endocytosis of autocrine immunosuppressive EVs through macropinocytosis, thereby aggravating inflammatory bowel disease. PPI-induced macropinocytosis facilitates the clearance of immunosuppressive EVs from tumour cells, improving antitumor immunity. PPI-induced macropinocytosis also increases doxorubicin and antisense oligonucleotides of microRNA-155 delivery efficiency by EVs, leading to enhanced therapeutic effects of drug-loaded EVs on tumours and acute liver failure. Mechanistically, PPIs reduce cytosolic pH, promote ATP6V1A (v-ATPase subunit) disassembly from the vacuolar membrane and enhance the assembly of plasma membrane v-ATPases, thereby inducing macropinocytosis. Altogether, our results reveal a mechanism for macropinocytic regulation and PPIs as potential modulators of EV levels, thus regulating their functions.

Extracellular vesicles derived from M2-like macrophages alleviate acute lung injury in a miR-709-mediated manner

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is characterised by an uncontrolled inflammatory response, and current treatment strategies have limited efficacy. Although the protective effect of M2-like macrophages (M2φ) and their extracellular vesicles (EVs) has been well-documented in other inflammatory diseases, the role of M2φ-derived EVs (M2φ-EVs) in the pathogenesis of ALI/ARDS remains poorly understood. The present study utilised a mouse model of lipopolysaccharide-induced ALI to first demonstrate a decrease in endogenous M2-like alveolar macrophage-derived EVs. And then, intratracheal instillation of exogenous M2φ-EVs from the mouse alveolar macrophage cell line (MH-S) primarily led to a take up by alveolar macrophages, resulting in reduced lung inflammation and injury. Mechanistically, the M2φ-EVs effectively suppressed the pyroptosis of alveolar macrophages and inhibited the release of excessive cytokines such as IL-6, TNF-α and IL-1β both in vivo and in vitro, which were closely related to NF-κB/NLRP3 signalling pathway inhibition. Of note, the protective effect of M2φ-EVs was partly mediated by miR-709, as evidenced by the inhibition of miR-709 expression in M2φ-EVs mitigated their protective effect against lipopolysaccharide-induced ALI in mice. In addition, we found that the expression of miR-709 in EVs derived from bronchoalveolar lavage fluid was correlated negatively with disease severity in ARDS patients, indicating its potential as a marker for ARDS severity. Altogether, our study revealed that M2φ-EVs played a protective role in the pathogenesis of ALI/ARDS, partly mediated by miR-709, offering a potential strategy for assessing disease severity and treating ALI/ARDS.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

TLR4, IgA and EpCAM Expression in Colorectal Cancer and Their Possible Association with Microbiota as a Pathogenic Factor; An Immunohistochemical and Genetic Study

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC) is thought to be related to immune response against gut microbiota. TLR4, IgA, and EpCAM have a role in intestinal local immune response and their altered expression related to both IBD and CRC. Lipopolysaccharide (LPS) is the main activator of TLR4. The objective of this study is to evaluate the possible role of intestinal microbiota in the pathogenesis of IBD and CRC through expression of TLR4, IgA and EpCAM.

METHODS

One hundred five cases were divided into (Group 1/ Control: 10 sections of normal colonic mucosa, Group 2/CRC: 51 cases, Group 3/IBD: 44 cases). Immunohistochemistry for TLR4, IgA, and EpCAM was done. LPS was assessed in all groups. TLR4 gene and protein expression were assessed in colorectal cancer cell line by RT-PCR and immunocytochemistry.

RESULTS

There was a significant correlation between TLR4 and tumor grade (P value 0.003 and 0.01 respectively). A significant correlation was found between IgA expression and T stage (P value 0.02) and between EpCAM expression and histologic type (P value 0.02). In comparison of CRC patients to controls; there was a statistically significant different expression of TLR4 positivity, IgA positivity and EpCAM (P value <0.001, 0.004, <0.001 respectively). Patients with CRC were compared to colitis patients and there was a statistically significant different expression of IgA positivity and EpCAM expression (P value <0.001). There was significant higher expression of TLR4 in CRC cell line than the fibroblast by both PCR and immunocytochemistry (P-value: 0.003 and 0.024 respectively). LPS level in CRC patients was significantly higher than the control and IBD groups (P values <0.001 and <0.001 respectively).

CONCLUSION

TLR4, IgA, EpCAM expression in both CRC and IBD might be related to the pathogenic role of microbiota and could represent potential prevention modalities and therapeutic targets.

Cellular evidence of communication strategies for small intestinal high endothelial cells: Ultrastructural insights of nano-scale exosomes and autophagy

Although several immune related cells of small intestine play an essential role in the intestinal homeostasis. However, information related to ultrastructural evidence of Nano-scale exosomes-multivesicular bodies and autophagic pathway in the high endothelial cells (HECs) of the small intestine in laying birds is still ambiguous. In present study, the HECs secreted the early endosome (ee), late endosome (le) and multivesicular bodies (MVBs) in the lamina propria of layer small intestine was confirmed by transmission electron microscopy. Besides that, in the cytoplasm of HECs showed many autophagosomes were directly associated with lysosomes and mitochondria. Further, the immunohistochemistry and immunofluorescence results showed that, the immunoreactivity and immuno-signaling of Nano-scale exosome related proteins, cluster of differentiation (CD63) and tumor susceptibility gene (TSG101), and autophagic related proteins, autophagic related gene (ATG7) and microtubule-associated protein light chain (LC3) were strong positive expression in the lamina propria of small intestine. These results prove that HECs play a well-known immunological role in the maintenance of intestinal homeostasis. In summary, these findings indicate that the small intestine's HECs have developed an innovative way of communication.

Nanomedicine-mediated drug delivery for potential treatment of inflammatory bowel disease: a narrative review

Background & aims: Inflammatory bowel disease (IBD) is a condition characterized by chronic inflammation of the gastrointestinal tract, manifesting as either Crohn's disease (CrD) or ulcerative colitis (UC). Current treatment options for CrD and UC primarily focus on symptom management. In recent years, advancements in nanotechnology have increased the clinical applicability of nanoparticles (NPs) in treating IBD. This review explores the current research on NP-mediated drug-delivery systems for IBD treatment and assesses its advantages and limitations. Results: The authors examine diverse nanomedicine applications for IBD and address the current challenges and prospects in the field to advance nanomediated therapies in the future. Conclusion: Innovative NP-based treatment strategies promise a reliable and effective approach to IBD management.

Extracellular Vesicles: Novel Potential Therapeutic Agents in Inflammatory Bowel Diseases

Patients affected by inflammatory bowel diseases (IBD) can nowadays benefit from a growing number of pharmacological options. However, in moderate-to-severe cases, the therapeutic response is still far from optimal, and treatment changes and optimizations are often required. Thus, researchers in this field are strongly engaged in studies aiming to identify new potential therapeutic targets. Extracellular vesicles (EVs) are tiny subcellular bodies with a phospholipid bilayer envelope containing bioactive molecules, which are released from different cells and are involved in intercellular communication. Recent pre-clinical data show their emerging role in the pathogenesis and treatment of IBD. In our review, we summarize current evidence about the function of EVs as active therapeutic agents in ulcerative colitis and Crohn's disease, analyzing the properties of EVs derived from different cellular sources and the mechanisms through which they may improve intestinal inflammation.

Efficacy of extracellular vesicles as a cell-free therapy in colitis: a systematic review and meta-analysis of animal studies

Background: Extracellular vesicles (EVs) mediate inflammation, immune responses, gut barrier integrity, and intestinal homeostasis. Recently, the application of EVs in the treatment of inflammatory bowel disease (IBD) has been under intensive focus. Some studies have been conducted in animal models of colitis, while systematic reviews and meta-analyses are lacking. The current study aimed to conduct a systematic review and meta-analysis of studies investigating the efficacy of EVs on IBD. Methods: A systematic retrieval of all studies in PubMed, EMBASE, MEDLINE, Web of Science, and Cochrane Library reported the effects of EVs in the colitis model up to 22 June 2023. The methodological quality was assessed based on SYRCLE's risk of bias (RoB) tool. Disease activity index (DAI), myeloperoxidase activity (MPO), histopathological score (HS), and inflammatory cytokines (TNF-α, NF-κB, IL-1β, IL-6, and IL-10) were extracted as analysis indicators by Web Plot Digitizer 4.5. A meta-analysis was performed to calculate the standardized mean difference and 95% confidence interval using random-effect models by Review Manager 5.3 and STATA 14.0 software. Results: A total of 21 studies were included in this meta-analysis. Although the heterogeneity between studies and the potential publication bias limits confidence in the extent of the benefit, EV treatment was superior to the control in the colitis evaluation with reduced DAI, HS, MPO activity, and pro-inflammatory cytokines, including TNF-α, NF-κB, IL-1β, and IL-6, while increasing the content of anti-inflammatory cytokine IL-10 (all p < 0.05). Conclusion: Our meta-analysis results supported the protective effect of EVs on colitis rodent models based on their potential role in IBD therapy and propelling the field toward clinical studies.

Exosomes as cutting-edge therapeutics in various biomedical applications: An update on engineering, delivery, and preclinical studies

Exosomes are cell-derived nanovesicles, circulating in different body fluids, and acting as an intercellular mechanism. They can be purified from culture media of different cell types and carry an enriched content of various protein and nucleic acid molecules originating from their parental cells. It was indicated that the exosomal cargo can mediate immune responses via many signaling pathways. Over recent years, the therapeutic effects of various exosome types were broadly investigated in many preclinical studies. Herein, we present an update on recent preclinical studies on exosomes as therapeutic and/or delivery agents for various applications. The exosome origin, structural modifications, natural or loaded active ingredients, size, and research outcomes were summarized for various diseases. Overall, the present article provides an overview of the latest exosome research interests and developments to clear the way for the clinical study design and application.

Exosomes-transferred LINC00668 Contributes to Thrombosis by Promoting NETs Formation in Inflammatory Bowel Disease

Epidemiological studies show an association between inflammatory bowel disease (IBD) and increased risk of thrombosis. However, how IBD influences thrombosis remains unknown. The current study shows that formation of neutrophil extracellular traps (NETs) significantly increased in the dextran sulfate sodium (DSS)-induced IBD mice, which in turn, contributes to thrombus formation in a NETs-dependent fashion. Furthermore, the exosomes isolated from the plasma of the IBD mice induce arterial and venous thrombosis in vivo. Importantly, proinflammatory factors-exposed intestinal epithelial cells (inflamed IECs) promote neutrophils to release NETs through their secreted exosomes. RNA sequencing revealed that LINC00668 is highly enriched in the inflamed IECs-derived exosomes. Mechanistically, LINC00668 facilitates the translocation of neutrophil elastase (NE) from the cytoplasmic granules to the nucleus via its interaction with NE in a sequence-specific manner, thereby inducing NETs release and thrombus formation. Importantly, berberine (BBR) suppresses the nuclear translocation of NE and subsequent NETs formation by inhibiting the interaction of LINC00668 with NE, thus exerting its antithrombotic effects. This study provides a novel pathobiological mechanism linking IBD and thrombosis by exosome-mediated NETs formation. Targeting LINC00668 can serve as a novel molecular treatment strategy to treat IBD-related thrombosis.

Blood-borne extracellular vesicles of bacteria and intestinal cells in patients with psychotic disorders

BACKGROUND

Human cells and bacteria secrete extracellular vesicles (EV) which play a role in intercellular communication. EV from the host intestinal epithelium are involved in the regulation of bacterial gene expression and growth. Bacterial EV (bactEV) produced in the intestine can pass to various tissues where they deliver biomolecules to many kinds of cells, including neurons. Emerging data indicate that gut microbiota is altered in patients with psychotic disorders. We hypothesized that the amount and content of blood-borne EV from intestinal cells and bactEV in psychotic patients would differ from healthy controls.

METHODS

We analyzed for human intestinal proteins by proteomics, for bactEV by metaproteomic analysis, and by measuring the level of lipopolysaccharide (LPS) in blood-borne EV from patients with psychotic disorders (n = 25), tested twice, in the acute phase of psychosis and after improvement, with age- and sex-matched healthy controls (n = 25).

RESULTS

Patients with psychotic disorders had lower LPS levels in their EV compared to healthy controls (p = .027). Metaproteome analyses confirmed LPS finding and identified Firmicutes and Bacteroidetes as dominating phyla. Total amounts of human intestine proteins in EV isolated from blood was lower in patients compared to controls (p = .02).

CONCLUSIONS

Our results suggest that bactEV and host intestinal EV are decreased in patients with psychosis and that this topic is worthy of further investigation given potential pathophysiological implications. Possible mechanisms involve dysregulation of the gut microbiota by host EV, altered translocation of bactEV to systemic circulation where bactEV can interact with both the brain and the immune system.

Quantitative proteomic analysis of local and systemic extracellular vesicles during Eimeria falciformis infectious cycle in the host

BACKGROUND

Extracellular vesicles (EVs) are membranous structures that are formed during pathophysiology, host-parasite interactions and parasite motility. Typically, apicomplexan-infected host cells secrete EVs which traverse local and systemic strata of the host as the parasites develop.

METHODS

Extracellular vesicles were isolated from the caecum and serum of Eimeria falciformis-infected mice during oocyst ingestion (0 h post-infection [0 hpi]), merozont stages 1 and 2 (68 and 116 hpi), oocyst shedding (7 days post-infection [7 dpi]) and host recovery (10 dpi) and subsequently characterized and profiled by tandem mass tag (TMT).

RESULTS

With the progression of E. falciformis life stages, subpopulation of EVs bearing EV biomarkers, including CD9, CD82, heat shock protein 70 (HSP70) and major histocompatibility complex (MHC) molecules, increased. A total of 860 and 1024 differentially expressed proteins were identified in serum EVs (sEVs) and caecum EVs (cEVs), respectively. Identified immune-related molecules (such as cytokines, receptors, immunoglobins, complements, hormones, inflammasomes), ion exchange and cell death-associated proteins were significantly expressed, at least during the E. falciformis first and second merozont stages. Bioinformatics assessment indicated that sEV proteins were at all time points implicated in antigen processing and presentation as well as natural killer cell-mediated cytotoxicity (68 hpi), complement activation/blood coagulation (116 hpi/10 dpi) and catabolic activities (7 dpi). In contrast, cEV proteins were involved in catabolic process, ion transport and antigen presentation (68 and 116 hpi). Host response to E. falciformis infection was similar to intestinal bacterium at 7 dpi and cell adhesion and intercellular protein transport at 10 dpi. In both systems, ferroptosis and necroptosis were common across the parasite's infectious cycle while apoptosis occurred at 68 hpi.

CONCLUSION

The proteomic data indicate that E. falciformis infection co-opts cellular and humoral responses through EV secretions, and that, host cell death and ionic imbalance are associated with E. falciformis infection. This study offers additional insight into host-parasite interactions and host regulatory EV proteins as potential disease indicators or diagnostic molecules.

Beyond Macromolecules: Extracellular Vesicles as Regulators of Inflammatory Diseases

Inflammation is the defense mechanism of the immune system against harmful stimuli such as pathogens, toxic compounds, damaged cells, radiation, etc., and is characterized by tissue redness, swelling, heat generation, pain, and loss of tissue functions. Inflammation is essential in the recruitment of immune cells at the site of infection, which not only aids in the elimination of the cause, but also initiates the healing process. However, prolonged inflammation often brings about several chronic inflammatory disorders; hence, a balance between the pro- and anti-inflammatory responses is essential in order to eliminate the cause while producing the least damage to the host. A growing body of evidence indicates that extracellular vesicles (EVs) play a major role in cell-cell communication via the transfer of bioactive molecules in the form of proteins, lipids, DNA, RNAs, miRNAs, etc., between the cells. The present review provides a brief classification of the EVs followed by a detailed description of how EVs contribute to the pathogenesis of various inflammation-associated diseases and their implications as a therapeutic measure. The latter part of the review also highlights how EVs act as a bridging entity in blood coagulation disorders and associated inflammation. The findings illustrated in the present review may open a new therapeutic window to target EV-associated inflammatory responses, thereby minimizing the negative outcomes.

Emerging diversity in extracellular vesicles and their roles in cancer

Extracellular vesicles have undergone a paradigm shift from being considered as 'waste bags' to being central mediators of cell-to-cell signaling in homeostasis and several pathologies including cancer. Their ubiquitous nature, ability to cross biological barriers, and dynamic regulation during changes in pathophysiological state of an individual not only makes them excellent biomarkers but also critical mediators of cancer progression. This review highlights the heterogeneity in extracellular vesicles by discussing emerging subtypes, such as migrasomes, mitovesicles, and exophers, as well as evolving components of extracellular vesicles such as the surface protein corona. The review provides a comprehensive overview of our current understanding of the role of extracellular vesicles during different stages of cancer including cancer initiation, metabolic reprogramming, extracellular matrix remodeling, angiogenesis, immune modulation, therapy resistance, and metastasis, and highlights gaps in our current knowledge of extracellular vesicle biology in cancer. We further provide a perspective on extracellular vesicle-based cancer therapeutics and challenges associated with bringing them to the clinic.

The Cellular Mechanism of Acupuncture for Ulcerative Colitis based on the Communication of Telocytes

Acupuncture can ameliorate or treat diseases according to the meridian theory in traditional Chinese medicine (TCM); however, its mechanism has not been scientifically clarified. On the other hand, telocytes (TCs) are morphologically in accordance with the meridian system, which needs further cytological investigations and acupuncture confirmation. The present study showed that acupuncture could activate TCs in several ways, alleviating rabbit ulcerative colitis. TCs could cytologically communicate the acupoints, the acupuncture sites in skin with their corresponding large intestine by TC homo-cellular junctions, exosomes around TCs, and TC-mediated nerves or blood vessels. TCs expressed transient receptor potential vanilloid type 4, the mechanosensitive channel protein that can transduce the mechanical stimulation of acupuncture into biochemical signals transferring along the extremely thin and long TCs. Collectively, a cellular mechanism diagram of acupuncture was concluded based on TC characteristics. Those results also confirmed the viewpoint that TCs were the key cells of meridian essence in TCM.

Extracellular vesicles and their indispensable roles in pathogenesis and treatment of inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a global disease with rising incidence worldwide, and its debilitating symptoms and dissatisfactory therapies have brought heavy burdens for patients. Extracellular vesicles (EVs), a heterogeneous population of lipid bilayer membranes containing abundant bioactive molecules, have been indicated to play important roles in the pathogenesis and treatment of many diseases. However, to our knowledge, comprehensive reviews summarizing the various roles of diverse source-derived EVs in the pathogenesis and treatment of IBD are still lacking. This review, not only summarizes the EV characteristics, but also focuses on the multiple roles of diverse EVs in IBD pathogenesis and their treatment potential. In addition, hoping to push forward the research frontiers, we point out several challenges that the researchers are faced, about EVs in current IBD research and future therapeutic applications. We also put forward our prospects on future exploration regarding EVs in IBD treatment, including developing IBD vaccines and paying more attention on apoptotic vesicles. This review is aimed to enrich the knowledge on the indispensable roles of EVs in IBD pathogenesis and treatment, providing ideas and reference for future therapeutic strategy for IBD treatment.

Dysbiosis in gastrointestinal pathophysiology: Role of the gut microbiome in Gulf War Illness

Gulf War Illness (GWI) has been reported in 25%-35% of veterans returned from the Gulf war. Symptoms of GWI are varied and include both neurological and gastrointestinal symptoms as well as chronic fatigue. Development of GWI has been associated with chemical exposure particularly with exposure to pyridostigmine bromide (PB) and permethrin. Recent studies have found that the pathology of GWI is connected to changes in the gut microbiota, that is the gut dysbiosis. In studies using animal models, the exposure to PB and permethrin resulted in similar changes in the gut microbiome as these found in GW veterans with GWI. Studies using animal models have also shown that phytochemicals like curcumin are beneficial in reducing the symptoms and that the extracellular vesicles (EV) released from gut bacteria and from the intestinal epithelium can both promote diseases and suppress diseases through the intercellular communication mechanisms. The intestinal epithelium cells produce EVs and these EVs of intestinal epithelium origin are found to suppress inflammatory bowel disease severity, suggesting the benefits of utilizing EV in treatments. On the contrary, EV from the plasma of septic mice enhanced the level of proinflammatory cytokines in vitro and neutrophils and macrophages in vivo, suggesting differences in the EV depending on the types of cells they were originated and/or influences of environmental changes. These studies suggest that targeting the EV that specifically have positive influences may become a new therapeutic strategy in the treatment of veterans with GWI.

Tissue-derived extracellular vesicles: Isolation, purification, and multiple roles in normal and tumor tissues

Extracellular vesicles (EVs) are particles released from cells, and their lipid bilayer membrane encloses large amounts of bioactive molecules that endow EVs with intercellular or inter-tissue communicational abilities. Tissue-derived extracellular vesicles (Ti-EVs) are EVs directly separated from the interstitial space of tissue. They could better reflect the actual physiological or pathological state of the tissue microenvironment compared with cell line-derived EVs and biofluid EVs, indicating their potential roles in elucidating the underlying mechanism of pathogenesis and guiding the diagnosis, therapeutic targeting, and cell-free treatment of diseases. However, there have been a relatively limited number of investigations of Ti-EVs. In this review, we have summarized general procedures for Ti-EVs isolation, as well as some caveats with respect to operations after the isolation step, such as purification and storage. In addition, we have also briefly concluded the current research trends on EVs from various normal and tumor tissues, aiming to cast new light on the future research direction of Ti-EVs.

Gastrointestinal consequences of lipopolysaccharide-induced lung inflammation

BACKGROUND

Respiratory inflammation is the body's response to lung infection, trauma or hypersensitivity and is often accompanied by comorbidities, including gastrointestinal (GI) symptoms. Why respiratory inflammation is accompanied by GI dysfunction remains unclear. Here, we investigate the effect of lipopolysaccharide (LPS)-induced lung inflammation on intestinal barrier integrity, tight-junctions, enteric neurons and inflammatory marker expression.

METHODS

Female C57bl/6 mice (6-8 weeks) were intratracheally administered LPS (5 µg) or sterile saline, and assessed after either 24 or 72 h. Total and differential cell counts in bronchoalveolar lavage fluid (BALF) were used to evaluate lung inflammation. Intestinal barrier integrity was assessed via cross sectional immunohistochemistry of tight junction markers claudin-1, claudin-4 and EpCAM. Changes in the enteric nervous system (ENS) and inflammation in the intestine were quantified immunohistochemically using neuronal markers Hu + and nNOS, glial markers GFAP and S100β and pan leukocyte marker CD45.

RESULTS

Intratracheal LPS significantly increased the number of neutrophils in BALF at 24 and 72 h. These changes were associated with an increase in CD45 + cells in the ileal mucosa at 24 and 72 h, increased goblet cell expression at 24 h, and increased expression of EpCAM at 72 h. LPS had no effect on the expression of GFAP, S100β, nor the number of Hu + neurons or proportion of nNOS neurons in the myenteric plexus.

CONCLUSIONS

Intratracheal LPS administration induces inflammation in the ileum that is associated with enhanced expression of EpCAM, decreased claudin-4 expression and increased goblet cell density, these changes may contribute to systemic inflammation that is known to accompany many inflammatory diseases of the lung.

Circulating Extracellular Vesicles Are Increased in Newly Diagnosed Celiac Disease Patients

Extracellular vesicles (EVs) are a class of circulating entities that are involved in intercellular crosstalk mechanisms, participating in homeostasis maintenance, and diseases. Celiac disease is a gluten-triggered immune-mediated disorder, characterized by the inflammatory insult of the enteric mucosa following local lymphocytic infiltration, resulting in villous atrophy. The goal of this research was the assessment and characterization of circulating EVs in celiac disease patients, as well as in patients already on an adequate gluten-free regimen (GFD). For this purpose, a novel and validated technique based on polychromatic flow cytometry that allowed the identification and enumeration of different EV sub-phenotypes was applied. The analysis evidenced that the total, annexin V+, leukocyte (CD45+), and platelet (CD41a+) EV counts were significantly higher in both newly diagnosed celiac disease patients and patients under GFD compared with the healthy controls. Endothelial-derived (CD31+) and epithelial-derived (EpCAM+) EV counts were significantly lower in subjects under gluten exclusion than in celiac disease patients, although EpCAM+ EVs maintained higher counts than healthy subjects. The numbers of EpCAM+ EVs were a statistically significant predictor of intraepithelial leukocytes (IEL). These data demonstrate that EVs could represent novel and potentially powerful disease-specific biomarkers in the context of celiac disease.

Gut-Derived Exosomes Induce Liver Injury After Intestinal Ischemia/Reperfusion by Promoting Hepatic Macrophage Polarization

Liver injury induced by intestinal ischemia/reperfusion (I/R) is accompanied by the polarization of Kupffer cells, which are specialized macrophages located in the liver. However, the causes of hepatic macrophage polarization after intestinal I/R remain unknown. This study investigated whether gut-derived exosomes contribute to the pathogenesis of liver injury triggered by intestinal I/R in a murine model and explored the underlying mechanisms. Intestinal I/R models were established by temporally clamping the superior mesenteric arteries of mice. Exosomes were isolated from the intestinal tissue of mice that underwent intestinal I/R or sham surgery according to a centrifugation-based protocol. Exosomes were co-cultured with RAW 264.7 macrophages or injected intravenously in mice. Liposomal clodronate was administered intraperitoneally to deplete the macrophages. Macrophage polarization was determined by flow cytometry, immunohistochemistry, and quantitative polymerase chain reaction. Liver injury was assessed by histological morphology and increased serum aspartate aminotransferase and alanine aminotransferase levels. Exosomes from mice intestines subjected to I/R (IR-Exo) promoted macrophage activation in vitro. Intravenous injection of IR-Exo caused hepatic M1 macrophage polarization and led to liver injury in mice. Depleting macrophages ameliorated liver injury caused by intestinal I/R or the injection of IR-Exo. Furthermore, inhibiting exosome release improved intestinal injury, liver function, and survival rates of mice subjected to intestinal I/R. Our study provides evidence that gut-derived exosomes induce liver injury after intestinal I/R by promoting hepatic M1 macrophage polarization. Inhibition of exosome secretion could be a therapeutic target for preventing hepatic impairment after intestinal I/R.

Understanding the versatile roles and applications of EpCAM in cancers: from bench to bedside

Epithelial cell adhesion molecule (EpCAM) functions not only in physiological processes but also participates in the development and progression of cancer. In recent decades, extensive efforts have been made to decipher the role of EpCAM in cancers. Great advances have been achieved in elucidating its structure, molecular functions, pathophysiological mechanisms, and clinical applications. Beyond its well-recognized role as a biomarker of cancer stem cells (CSCs) or circulating tumor cells (CTCs), EpCAM exhibits novel and promising value in targeted therapy. At the same time, the roles of EpCAM in cancer progression are found to be highly context-dependent and even contradictory in some cases. The versatile functional modules of EpCAM and its communication with other signaling pathways complicate the study of this molecule. In this review, we start from the structure of EpCAM and focus on communication with other signaling pathways. The impacts on the biology of cancers and the up-to-date clinical applications of EpCAM are also introduced and summarized, aiming to shed light on the translational prospects of EpCAM.

Ibrutinib Prevents Acute Lung Injury via Multi-Targeting BTK, FLT3 and EGFR in Mice

Ibrutinib has potential therapeutic or protective effects against viral- and bacterial-induced acute lung injury (ALI), likely by modulating the Bruton tyrosine kinase (BTK) signaling pathway. However, ibrutinib has multi-target effects. Moreover, immunity and inflammation targets in ALI treatment are poorly defined. We investigated whether the BTK-, FLT3-, and EGFR-related signaling pathways mediated the protective effects of ibrutinib on ALI. The intratracheal administration of poly I:C or LPS after ibrutinib administration in mice was performed by gavage. The pathological conditions of the lungs were assessed by micro-CT and HE staining. The levels of neutrophils, lymphocytes, and related inflammatory factors in the lungs were evaluated by ELISA, flow cytometry, immunohistochemistry, and immunofluorescence. Finally, the expression of proteins associated with the BTK-, FLT3-, and EGFR-related signaling pathways were evaluated by Western blotting. Ibrutinib (10 mg/kg) protected against poly I:C-induced (5 mg/kg) and LPS-induced (5 mg/kg) lung inflammation. The wet/dry weight ratio (W/D) and total proteins in the bronchoalveolar lavage fluid (BALF) were markedly reduced after ibrutinib (10 mg/kg) treatment, relative to the poly I:C- and LPS-treated groups. The levels of ALI indicators (NFκB, IL-1β, IL-6, TNF-α, IFN-γ, neutrophils, and lymphocytes) were significantly reduced after treatment. Accordingly, ibrutinib inhibited the poly I:C- and LPS-induced BTK-, FLT3-, and EGFR-related pathway activations. Ibrutinib inhibited poly I:C- and LPS-induced acute lung injury, and this may be due to its ability to suppress the BTK-, FLT3-, and EGFR-related signaling pathways. Therefore, ibrutinib is a potential protective agent for regulating immunity and inflammation in poly I:C- and LPS-induced ALI.

Extracellular vesicle miRNAs promote the intestinal microenvironment by interacting with microbes in colitis

Inflammatory bowel disease (IBD) is a global disease with no cure. Disruption of the microbial ecosystem is considered to be an important cause of IBD. Extracellular vesicles (EVs) are vital participants in cell-cell and cell-organism communication. Both host-derived EVs and bacteria-derived membrane vesicles (OMVs) contribute to homeostasis in the intestine. However, the roles of EVs-miRNAs and MVs in host-microbe interactions in colitis remain unclear. In the present study, the animal model of colitis was established by dextran sulfate sodium (DSS) to investigate the changes of miRNAs in colonic EVs from colitis. Several miRNAs were significantly altered in colitis EVs. miR-181b-5p transplantation inhibited M1 macrophage polarization and promoted M2 polarization to reduce the levels of inflammation both in acute and remission of chronic colitis. miR-200b-3p could interact with bacteria and regulate the composition of the microbiota, which contributed to intestinal barrier integrity and homeostasis. Notably, MVs from normal feces could effectively reverse the composition of the intestinal microbiota, restore the intestinal barrier and rescue colitis, and BMVs from colitis would also have similar effects after miR-200b-3p treatment. Our results preliminarily identify a vesicle-based host-microbe interaction cycle in colitis and provide new ideas for colitis treatment.

Trophoblast-Derived Extracellular Vesicles Promote Preeclampsia by Regulating Macrophage Polarization

BACKGROUND

Systemic inflammation caused by dysfunctional macrophages is a crucial pathogenetic event in preeclampsia (PE). Trophoblast-derived extracellular vesicles (T-EVs) are potent immune cell signaling modulators in pregnancy. Herein, we aimed to investigate T-EVs' effect and mechanism on macrophage polarization and its role in PE pathogenesis, which remain unclear.

METHODS

Flow cytometry and immunochemistry were used to determine placental macrophage phenotypes. T-EVs were immuno-isolated via placental alkaline phosphatase antibody and identified by transmission electron microscopy and nanoparticle tracking analysis. Quantitative real-time polymerase chain reaction and flow cytometry were used to examine the effects of T-EVs on macrophage polarization, and correlation analysis of T-EVs lipidomics and macrophages transcriptome were performed to explore how T-EVs modulate macrophages. Animal experiments were established to investigate the relationship among PE, T-EVs, and macrophages.

RESULTS

Macrophages shift from the M2 to M1 phenotype in the preeclamptic placenta. Also, T-EVs from women with PE (PE-EVs) significantly upregulated M1 gene markers and significantly downregulated CD163 expression in macrophages compared with T-EVs in women with normal pregnancies (NP-EVs). Mechanistically, correlation analysis with T-EVs lipidome and the transcriptome of macrophages treated with PE-EVs or NP-EVs indicated that 37 lipids altered in PE-EVs considerably affected classical inflammatory biological pathways in macrophages. Finally, animal experiments revealed that PE-EVs triggered PE-like symptoms in pregnant mice, which were alleviated after macrophage depletion.

CONCLUSIONS

T-EVs from women with PE could promote preeclampsia by inducing macrophage imbalance polarization, signifying a potential novel interventional target for the prevention and management of PE.

The Pathogenicity and Synergistic Action of Th1 and Th17 Cells in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn's disease, are characterized by chronic idiopathic inflammation of gastrointestinal tract. Although the pathogenesis of IBD remains unknown, intestinal immune dysfunction has been considered as the core pathogenesis. In the intestinal immune system, T helper 1 (Th1) and Th17 cells are indispensable for intestine homeostasis via preventing pathogenic bacteria invasion, regulating metabolism and functions of intestinal epithelial cells (IECs), and promoting IEC self-renewal. However, during the development of IBD, Th1 and Th17 cells acquire the pathogenicity and change from the maintainer of intestinal homeostasis to the destroyer of intestinal mucosa. Because of coexpressing interferon-γ and interleukin-17A, Th17 cells with pathogenicity are named as pathogenic Th17 cells. In disease states, Th1 cells impair IEC programs by inducing IEC apoptosis, recruiting immune cells, promoting adhesion molecules expression of IECs, and differentiating to epithelial cell adhesion molecule-specific interferon γ-positive Th1 cells. Pathogenic Th17 cells induce IEC injury by triggering IBD susceptibility genes expression of IECs and specifically killing IECs. In addition, Th1 and pathogenic Th17 cells could cooperate to induce colitis. The evidences from IBD patients and animal models demonstrate that synergistic action of Th1 and pathogenic Th17 cells occurs in the diseases development and aggravates the mucosal inflammation. In this review, we focused on Th1 and Th17 cell programs in homeostasis and intestine inflammation and specifically discussed the impact of Th1 and Th17 cell pathogenicity and their synergistic action on the onset and the development of IBD. We hoped to provide some clues for treating IBD.

Extracellular Vesicles: The Next Generation Theranostic Nanomedicine for Inflammatory Bowel Disease

The recent rapid development in the field of extracellular vesicles (EVs) based nanotechnology has provided unprecedented opportunities for nanomedicine platforms. As natural nanocarriers, EVs such as exosomes, exosome-like nanoparticles and outer membrane vesicles (OMVs), have unique structure/composition/morphology characteristics, and show excellent physical and chemical/biochemical properties, making them a new generation of theranostic nanomedicine. Here, we reviewed the characteristics of EVs from the perspective of their formation and biological function in inflammatory bowel disease (IBD). Moreover, EVs can crucially participate in the interaction and communication of intestinal epithelial cells (IECs)-immune cells-gut microbiota to regulate immune response, intestinal inflammation and intestinal homeostasis. Interestingly, based on current representative examples in the field of exosomes and exosome-like nanoparticles for IBD treatment, it is shown that plant, milk, and cells-derived exosomes and exosome-like nanoparticles can exert a therapeutic effect through their components, such as proteins, nucleic acid, and lipids. Moreover, several drug loading methods and target modification of exosomes are used to improve their therapeutic capability. We also discussed the application of exosomes and exosome-like nanoparticles in the treatment of IBD. In this review, we aim to better and more clearly clarify the underlying mechanisms of the EVs in the pathogenesis of IBD, and provide directions of exosomes and exosome-like nanoparticles mediated for IBD treatment.

Approaches to incorporate extracellular vesicles into exposure science, toxicology, and public health research

Extracellular vesicles (EVs) represent small, membrane-enclosed particles that are derived from parent cells and are secreted into the extracellular space. Once secreted, EVs can then travel and communicate with nearby or distant cells. Due to their inherent stability and biocompatibility, these particles can effectively transfer RNAs, proteins, and chemicals/metabolites from parent cells to target cells, impacting cellular and pathological processes. EVs have been shown to respond to disease-causing agents and impact target cells. Given that disease-causing agents span environmental contaminants, pathogens, social stressors, drugs, and other agents, the translation of EV methods into public health is now a critical research gap. This paper reviews approaches to translate EVs into exposure science, toxicology, and public health applications, highlighting blood as an example due to its common use within clinical, epidemiological, and toxicological studies. Approaches are reviewed surrounding the isolation and characterization of EVs and molecular markers that can be used to inform EV cell-of-origin. Molecular cargo contained within EVs are then discussed, including an original analysis of blood EV data from Vesiclepedia. Methods to evaluate functional consequences and target tissues of EVs are also reviewed. Lastly, the expanded integration of these approaches into future public health applications is discussed, including the use of EVs as promising biomarkers of exposure, effect, and disease. IMPACT STATEMENT: Extracellular vesicles (EVs) represent small, cell-derived structures consisting of molecules that can serve as biomarkers of exposure, effect, and disease. This review lays a novel foundation for integrating EVs, a rapidly advancing molecular biological tool, into the field of public health research including epidemiological, toxicological, and clinical investigations. This article represents an important advancement in public health and exposure science as it is among the first to translate EVs into this field.

Intestine epithelial cell-derived extracellular vesicles alleviate inflammation induced by Clostridioides difficile TcdB through the activity of TGF-β1

Background

Clostridioides difficile infection (CDI) has been primarily associated with the toxin B (TcdB), one of the three known protein toxins secreted by C. difficile, which can activate the intestinal immune system and lead to pathological damage. Even though the biological functions of intestine epithelial cell-derived extracellular vesicles (I-Evs) have been well documented, the role of I-Evs in the process of CDI is still unknown.

Objectives

The protective effect of I-Evs against C. difficile TcdB was investigated both in cultured murine colon carcinoma MC38 cells and a mouse model used in this study.

Results

Mouse I-Evs with mean diameter ranging from 100 to 200 nm and a density of 1.09-1.17 g/mL were obtained and confirmed containing the Ev-associated specific surface markers CD63 and TSG101 as well as high level of TGF-β1. In MC38 cells, I-Evs were able to decrease the gene expression of IL-6, TNF-α, IL-1β, and IL-22 induced by C. difficile TcdB, but to increase both the gene expression and protein levels of TGF-β1. I-Evs treatment via intraperitoneal administration alleviates C. difficile TcdB-induced local colon inflammation in mice and increased their survival rate from 50% up to 80%. Furthermore, I-Evs induced an increase in the proportion of CD4+Foxp3+Tregs in vitro and in vivo through a TGF-β1-dependent mechanism by activating the TGF-β1 pathway and prompting phosphorylation of the downstream proteins Smad 2/3.

Conclusion

For the first time, our study demonstrated that I-Evs originated from intestine epithelial cells can alleviate inflammation induced by C. difficile TcdB both in vitro and in vivo. Therefore, I-Evs might be potentially a novel endogenous candidate for effective treatment of CDI.

Attenuation of Excess TNF-α Release in Crohn’s Disease by Silencing of iRHOMs 1/2 and the Restoration of TGF-β Mediated Immunosuppression Through Modulation of TACE Trafficking

TNFα converting enzyme (TACE) is a transmembrane metalloprotease that sheds an assortment of signaling receptors, cytokines, growth factors, and pro-inflammatory mediators. In Crohn’s disease (CD), TACE activity is upregulated, resulting in a marked increase of TNFα secretion and inflammation. Although treatment of CD with TNFα monoclonal antibodies is beneficial, many patients are at risk for acquiring opportunistic infections, and the treatment efficacy of TNFα monoclonal antibodies typically decreases over time. This study investigated an alternative approach for mitigating TNFα release by knocking down TACE membrane translocation in macrophages via inhibitory rhomboid proteins 1 and 2 (iRHOMs 1/2) siRNA treatment. First we measured TGFβRII shedding in ex vivo plasma samples collected from CD patients and healthy control subjects (N=40 per group). Then, we measured TGFβRII shedding and the expression and production of TGFβ ligand, TNFα, IL-6, IL-1β, IL-10, and total versus membranous TACE in vitro with THP-1 derived macrophage infected with Mycobacterium avium subspecies paratuberculosis (MAP), a highly studied CD-related pathogen. We determined that TGFβRII shedding was significantly higher in CD patients compared to healthy controls [515.52 ± 54.23 pg/mL vs 310.81 ± 43.16 pg/mL, respectively], and MAP-infected CD plasma samples had significantly more TGFβRII shedding (601.83 ± 49.56 pg/mL) than MAP-negative CD samples (430.37 ± 45.73 pg/mL). Moreover, we also determined that TACE production; TGFβ ligand expression and production; and TGFβRII shedding were also higher in MAP-infected THP-1 macrophages. Nevertheless, once we transfected the MAP infected macrophages with iRHOM siRNA, TACE production and membrane localization were significantly decreased, resulting in a significant decrease in TGFβRII shedding; an increase in Smad3 phosphorylation; a decrease in the expression and production of pro-inflammatory cytokines; and a decrease in the expression and production of stricture-associated factor, plasminogen activator inhibitor-1 (PAI-1). Our data clearly demonstrates that the regression of TACE trafficking, via iRHOM 1/2 silencing, significantly reduces the release of TNFα and restores the immunosuppressive capabilities of TGFβ signaling, which ultimately reverses inflammatory tissue damage. Accordingly, this study may provide a framework for the creation of newer, safer therapeutic options designed to treat inflammatory autoimmune diseases such as CD and rheumatoid arthritis.

Microbial DNA enrichment promotes liver steatosis and fibrosis in the course of non-alcoholic steatohepatitis

AIM

Low-grade inflammation is the hallmark of non-alcoholic fatty liver diseases (NAFLD) and non-alcoholic steatohepatitis (NASH). The leakage of microbiota-derived products can contribute to liver inflammation during NAFLD/NASH development. Here, we assessed the roles of gut microbial DNA-containing extracellular vesicles (mEVs) in regulating liver cellular abnormalities in the course of NAFLD/NASH.

METHODS

We performed studies with Vsig4^-/- , C3^-/- , cGAS^-/- , and their wild-type littermate mice. Vsig4+ macrophage population and bacterial DNA abundance were examined in both mouse and human liver by either flow cytometric or immunohistochemistry analysis. Gut mEVs were adoptively transferred into Vsig4^-/- , C3^-/- , cGAS^-/- , or littermate WT mice, and hepatocyte inflammation and HSC fibrogenic activation were measured in these mice.

RESULTS

Non-alcoholic fatty liver diseases and non-alcoholic steatohepatitis development was concomitant with a diminished liver Vsig4+ macrophage population and a marked bacterial DNA enrichment in both hepatocytes and HSCs. In the absence of Vsig4+ macrophages, gut mEVs translocation led to microbial DNA accumulation in hepatocytes and HSCs, resulting elevated hepatocyte inflammation and HSC fibrogenic activation. In contrast, in lean WT mice, Vsig4+ macrophages remove gut mEVs from bloodstream through a C3-dependent opsonization mechanism and prevent the infiltration of gut mEVs into hepatic cells. Additionally, Vsig4^-/- mice more quickly developed significant liver steatosis and fibrosis than WT mice after Western diet feeding. In vitro treatment with NASH mEVs triggered hepatocyte inflammation and HSC fibrogenic activation. Microbial DNAs are key cargo for the effects of gut mEVs by activating cGAS/STING.

CONCLUSION

Accumulation of microbial DNAs fuels the development of NAFLD/NASH-associated liver abnormalities.

Intestinal epithelial cell-derived exosomes package microRNA-23a-3p alleviate gut damage after ischemia/reperfusion via targeting MAP4K4

Intestinal epithelial cells (IECs) contribute to regulation of gut injury after intestinal ischemia/reperfusion (II/R). Exosomes are well documented to deliver bioactive molecules to recipient cells for the purpose of modulating cell function. However, the role of IEC-derived exosomes in gut damage after II/R and the underlying mechanisms remain unclear. Here, we investigated the effects of exosomal miR-23a-3p on gut damage using primary IECs that underwent oxygen-glucose deprivation (OGD) as well as II/R rats. We observed that exosomes released by IECs attenuated damage in IECs that underwent OGD in vitro (P < 0.05) as well as the degree of gut injury after an II/R assault in vivo (P < 0.05). Injection of miR-23a-3p knockdown exosomes aggravated the II/R injury, whereas PF-6260933, a small-molecule inhibitor of MAP4K4, partly reversed the injury. Underlying mechanistic studies revealed that exosomal miR-23a-3p attenuated gut damage by regulating its downstream target, MAP4K4.

Hypoxic Cell-Derived Extracellular Vesicles Aggravate Rectal Injury Following Radiotherapy via MiR-122-5p

Radiation-induced rectal injury is a common side effect of radiotherapy. Hypoxia often occurs after radiotherapy. This study aimed to explore the bystander effect of hypoxia on radiation-induced rectal injury. In vivo, apoptosis increased nearby the highly hypoxic area in the rectal tissues in the mouse models of radiation-induced rectal injury, indicating the potential involvement of hypoxia. In vitro, flow cytometry and Western blotting showed that both hypoxia and hypoxic human intestinal epithelial crypt (HIEC) cell supernatant promoted apoptosis in normoxic HIEC cells. The pro-apoptotic effect of extracellular vesicles (EVs) derived from hypoxic HIEC cell to normoxic HIEC cells was then determined. MiR-122-5p was chosen for further studies through a microRNA (miRNA) microarray assay and apoptosis was alleviated in cells receiving miR-122-5p inhibiting hypoxic EVs. Together, our study demonstrated that the miR-122-5p containing-EVs derived from hypoxic HIEC cells promoted apoptosis in normoxic HIEC cells. Hypoxic EV-derived miR-122-5p plays a critical pathologic role in radiation-induced rectal injury and may be a potential therapeutic target.

EpCAM Is Essential to Maintaining the Immune Homeostasis of Intestines via Keeping the Expression of pIgR in the Intestinal Epithelium of Mice

EpCAM deficiency causes congenital tufting enteropathy (CTE) which is considered as one kinds of very early onset inflammatory bowel disease (IBD). However, functions of EpCAM on regulating the immunity of intestines are still unclear. To study the mechanism of EpCAM on maintaining the intestinal immune homeostasis, the intestines of WT and EpCAM^-/- mice at E18.5, P0 and P3 stages were collected for morphological, histological and gene expression tests. Serious inflammation was detected in the small intestines of P3 EpCAM^-/- mice. Compared to WT mice, genes related to inflammatory factors and immunity cells, including TNFα, IL-1β, IL-6, IL-8rb, MIP2, MCP1, Ly6d and Ly6g, were all significantly upregulated and the expression of intestinal abundance matrix metalloproteinases (MMPs) was also significantly increased in the intestines of EpCAM^-/- mice at E18.5, P0 and P3 stages. Signals of p38, ERK1/2 and JNK were hyper-activated in the intestines of EpCAM^-/- mice. The expression of pIgR was significantly decreased and the expression and activation of transcriptional factors which promote the expression of pIgR were also reduced in the intestines of EpCAM^-/- mice compared to WT controls. In conclusion, EpCAM could maintain the immune homeostasis of intestines via keeping the expression of pIgR in the intestinal epithelium.