Biliary exosomes influence cholangiocyte regulatory mechanisms and proliferation through interaction with primary cilia

Biliary fibrosis is an important but neglected pathological feature in hepatobiliary disorders: from molecular mechanisms to clinical implications

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality. Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders, which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries. Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases. In this review, we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations, epidemiology, and aberrant cellular composition involving the biliary ductules, cholangiocytes, immune system, fibroblasts, and the microbiome. We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies. This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

Most recent advances and applications of extracellular vesicles in tackling neurological challenges

Over the past few decades, there has been a notable increase in the global burden of central nervous system (CNS) diseases. Despite advances in technology and therapeutic options, neurological and neurodegenerative disorders persist as significant challenges in treatment and cure. Recently, there has been a remarkable surge of interest in extracellular vesicles (EVs) as pivotal mediators of intercellular communication. As carriers of molecular cargo, EVs demonstrate the ability to traverse the blood-brain barrier, enabling bidirectional communication. As a result, they have garnered attention as potential biomarkers and therapeutic agents, whether in their natural form or after being engineered for use in the CNS. This review article aims to provide a comprehensive introduction to EVs, encompassing various aspects such as their diverse isolation methods, characterization, handling, storage, and different routes for EV administration. Additionally, it underscores the recent advances in their potential applications in neurodegenerative disorder therapeutics. By exploring their unique capabilities, this study sheds light on the promising future of EVs in clinical research. It considers the inherent challenges and limitations of these emerging applications while incorporating the most recent updates in the field.

Cilia and Extracellular Vesicles in Brain Development and Disease

Primary and motile cilia are thin, hair-like cellular projections from the cell surface involved in movement, sensing, and communication between cells. Extracellular vesicles (EVs) are small membrane-bound vesicles secreted by cells and contain various proteins, lipids, and nucleic acids that are delivered to and influence the behavior of other cells. Both cilia and EVs are essential for the normal functioning of brain cells, and their malfunction can lead to several neurological diseases. Cilia and EVs can interact with each other in several ways, and this interplay plays a crucial role in facilitating various biological processes, including cell-to-cell communication, tissue homeostasis, and pathogen defense. Cilia and EV crosstalk in the brain is an emerging area of research. Herein, we summarize the detailed molecular mechanisms of cilia and EV interplay and address the ciliary molecules that are involved in signaling and cellular dysfunction in brain development and diseases. Finally, we discuss the potential clinical use of cilia and EVs in brain diseases.

DNA Content in Embryonic Extracellular Vesicles Is Independent of the Apoptotic Rate in Bovine Embryos Produced In Vitro

Pre-implantation embryos release extracellular vesicles containing different molecules, including DNA. The presence of embryonic DNA in E-EVs released into the culture medium during in vitro embryo production could be useful for genetic diagnosis. However, the vesicles containing DNA might be derived from embryos suffering from apoptosis, i.e., embryos of bad quality. This work intended to confirm that embryos release DNA that is useful for genotyping by evaluating the effect of embryonic apoptosis on DNA content in E-EVs. Bovine embryos were produced by parthenogenesis and in vitro fertilization (IVF). On Day 5, morulae were transferred to individual cultures in an EV-depleted SOF medium. On Day 7, embryos were used to evaluate cellular apoptosis, and each culture medium was collected to evaluate E-EV concentration, characterization, and DNA quantification. While no effect of the origin of the embryo on the apoptotic rate was found, arrested morulae had a higher apoptotic rate. E-EVs containing DNA were identified in all samples, and the concentration of those vesicles was not affected by the origin or quality of the embryos. However, the concentration of DNA was higher in EVs released by the arrested parthenogenetic embryos. There was a correlation between the concentration of E-EVs, the concentration of DNA-positive E-EVs, and the concentration of DNA. There was no negative effect of apoptotic rate on DNA-positive E-EVs and DNA concentration; however, embryos of the best quality with a low apoptotic rate still released EVs containing DNA. This study confirms that the presence of DNA in E-EVs is independent of embryo quality. Therefore, E-EVs could be used in liquid biopsy for noninvasive genetic diagnosis.

The miR-669a-5p/G3BP/HDAC6/AKAP12 Axis Regulates Primary Cilia Length

Primary cilia are conserved organelles in most mammalian cells, acting as "antennae" to sense external signals. Maintaining a physiological cilium length is required for cilium function. MicroRNAs (miRNAs) are potent gene expression regulators, and aberrant miRNA expression is closely associated with ciliopathies. However, how miRNAs modulate cilium length remains elusive. Here, using the calcium-shock method and small RNA sequencing, a miRNA is identified, namely, miR-669a-5p, that is highly expressed in the cilia-enriched noncellular fraction. It is shown that miR-669a-5p promotes cilium elongation but not cilium formation in cultured cells. Mechanistically, it is demonstrated that miR-669a-5p represses ras-GTPase-activating protein SH3-domain-binding protein (G3BP) expression to inhibit histone deacetylase 6 (HDAC6) expression, which further upregulates A-kinase anchor protein 12 (AKAP12) expression. This effect ultimately blocks cilia disassembly and leads to greater cilium length, which can be restored to wild-type lengths by either upregulating HDAC6 or downregulating AKAP12. Collectively, these results elucidate a previously unidentified miR-669a-5p/G3BP/HDAC6/AKAP12 signaling pathway that regulates cilium length, providing potential pharmaceutical targets for treating ciliopathies.

The role of extracellular vesicles in cholangiocarcinoma tumor microenvironment

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor that originates from the biliary system. With restricted treatment options at hand, the challenging aspect of early CCA diagnosis leads to a bleak prognosis. Besides the intrinsic characteristics of tumor cells, the generation and progression of CCA are profoundly influenced by the tumor microenvironment, which engages in intricate interactions with cholangiocarcinoma cells. Of notable significance is the role of extracellular vesicles as key carriers in enabling communication between cancer cells and the tumor microenvironment. This review aims to provide a comprehensive overview of current research examining the interplay between extracellular vesicles and the tumor microenvironment in the context of CCA. Specifically, we will emphasize the significant contributions of extracellular vesicles in molding the CCA microenvironment and explore their potential applications in the diagnosis, prognosis assessment, and therapeutic strategies for this aggressive malignancy.

Compartmentalized ciliation changes of oligodendrocytes in aged mouse optic nerve

Primary cilia are microtubule-based sensory organelles that project from the apical surface of most mammalian cells, including oligodendrocytes, which are myelinating cells of the central nervous system (CNS) that support critical axonal function. Dysfunction of CNS glia is associated with aging-related white matter diseases and neurodegeneration, and ciliopathies are known to affect CNS white matter. To investigate age-related changes in ciliary profile, we examined ciliary length and frequency in the retinogeniculate pathway, a white matter tract commonly affected by diseases of aging but in which expression of cilia has not been characterized. We found expression of Arl13b, a marker of primary cilia, in a small group of Olig2-positive oligodendrocytes in the optic nerve, optic chiasm, and optic tract in young and aged C57BL/6 wild-type mice. While the ciliary length and ciliated oligodendrocyte cells were constant in young mice in the retinogeniculate pathway, there was a significant increase in ciliary length in the anterior optic nerve as compared to the aged animals. Morphometric analysis confirmed a specific increase in the ciliation rate of CC1+ /Olig2+ oligodendrocytes in aged mice compared with young mice. Thus, the prevalence of primary cilia in oligodendrocytes in the visual pathway and the age-related changes in ciliation suggest that they may play important roles in white matter and age-associated optic neuropathies.

Exploring the Impact of Exosomal Cargos on Osteosarcoma Progression: Insights into Therapeutic Potential

Osteosarcoma (OS) is a primary malignant bone tumor with high metastasis. Poor prognosis highlights a clinical need for novel therapeutic strategies. Exosomes, also known as extracellular vesicles, have been identified as essential players in the modulation of cancer. Recent studies have suggested that OS-derived exosomes can drive pro-tumorigenic or anti-tumorigenic phenotypes by transferring specific cargos, including proteins, nucleic acids, and metabolites, to neighboring cells, significantly impacting the regulation of cellular processes. This review discusses the advancement of exosomes and their cargos in OS. We examine how these exosomes contribute to the modulation of cellular phenotypes associated with tumor progression and metastasis. Furthermore, we explore the potential of exosomes as valuable biomarkers for diagnostics and prognostic purposes and their role in shaping innovative therapeutic strategies in OS treatment development.

MicroRNAs in Small Extracellular Vesicles from Amniotic Fluid and Maternal Plasma Associated with Fetal Palate Development in Mice

Cleft palate (CP) is a common congenital birth defect. Cellular and morphological processes change dynamically during palatogenesis, and any disturbance in this process could result in CP. However, the molecular mechanisms steering this fundamental phase remain unclear. One study suggesting a role for miRNAs in palate development via maternal small extracellular vesicles (SEVs) drew our attention to their potential involvement in palatogenesis. In this study, we used an in vitro model to determine how SEVs derived from amniotic fluid (ASVs) and maternal plasma (MSVs) influence the biological behaviors of mouse embryonic palatal mesenchyme (MEPM) cells and medial edge epithelial (MEE) cells; we also compared time-dependent differential expression (DE) miRNAs in ASVs and MSVs with the DE mRNAs in palate tissue from E13.5 to E15.5 to study the dynamic co-regulation of miRNAs and mRNAs during palatogenesis in vivo. Our results demonstrate that some pivotal biological activities, such as MEPM proliferation, migration, osteogenesis, and MEE apoptosis, might be directed, in part, by stage-specific MSVs and ASVs. We further identified interconnected networks and key miRNAs such as miR-744-5p, miR-323-5p, and miR-3102-5p, offering a roadmap for mechanistic investigations and the identification of early CP biomarkers.

New insights into the molecular basis of alcohol abstinence and relapse in alcohol-associated liver disease

Alcohol use disorder remains a significant public health concern, affecting around 5% of adults worldwide. Novel pathways of damage have been described during the last years, providing insight into the mechanism of injury due to alcohol misuse beyond the direct effect of ethanol byproducts on the liver parenchyma and neurobehavioral mechanisms. Thus, the gut-liver-brain axis and immune system involvement could be therapeutic targets for alcohol use disorder. In particular, changes in gut microbiota composition and function, and bile acid homeostasis, have been shown with alcohol consumption and cessation. Alcohol can also directly disrupt intestinal and blood-brain barriers. Activation of the immune system can be triggered by intestinal barrier dysfunction and translocation of bacteria, pathogen-associated molecular patterns (such as lipopolysaccharide), cytokines, and damage-associated molecular patterns. These factors, in turn, promote liver and brain inflammation and the progression of liver fibrosis. Other involved mechanisms include oxidative stress, apoptosis, autophagy, and the release of extracellular vesicles and miRNA from hepatocytes. Potential therapeutic targets include gut microbiota (probiotics and fecal microbiota transplantation), neuroinflammatory pathways, as well as neuroendocrine pathways, for example, the ghrelin system (ghrelin receptor blockade), incretin mimetics (glucagon-like peptide-1 analogs), and the mineralocorticoid receptor system (spironolactone). In addition, support with psychological and behavioral treatments is essential to address the multiple dimensions of alcohol use disorder. In the future, a personalized approach considering these novel targets can contribute to significantly decreasing the alcohol-associated burden of disease.

Extracellular vesicle-mediated targeting strategies for long-term health benefits in gestational diabetes

Extracellular vesicles (EVs) are critical mediators of cell communication, playing important roles in regulating molecular cross-talk between different metabolic tissues and influencing insulin sensitivity in both healthy and gestational diabetes mellitus (GDM) pregnancies. The ability of EVs to transfer molecular cargo between cells imbues them with potential as therapeutic agents. During pregnancy, the placenta assumes a vital role in metabolic regulation, with multiple mechanisms of placenta-mediated EV cross-talk serving as central components in GDM pathophysiology. This review focuses on the role of the placenta in the pathophysiology of GDM and explores the possibilities and prospects of targeting the placenta to address insulin resistance and placental dysfunction in GDM. Additionally, we propose the use of EVs as a novel method for targeted therapeutics in treating the dysfunctional placenta. The primary aim of this review is to comprehend the current status of EV targeting approaches and assess the potential application of these strategies in placental therapeutics, thereby delivering molecular cargo and improving maternal and fetal outcomes in GDM. We propose that EVs have the potential to revolutionize GDM management, offering hope for enhanced maternal-fetal health outcomes and more effective treatments.

Primary cilia as dynamic and diverse signalling hubs in development and disease

Primary cilia, antenna-like sensory organelles protruding from the surface of most vertebrate cell types, are essential for regulating signalling pathways during development and adult homeostasis. Mutations in genes affecting cilia cause an overlapping spectrum of >30 human diseases and syndromes, the ciliopathies. Given the immense structural and functional diversity of the mammalian cilia repertoire, there is a growing disconnect between patient genotype and associated phenotypes, with variable severity and expressivity characteristic of the ciliopathies as a group. Recent technological developments are rapidly advancing our understanding of the complex mechanisms that control biogenesis and function of primary cilia across a range of cell types and are starting to tackle this diversity. Here, we examine the structural and functional diversity of primary cilia, their dynamic regulation in different cellular and developmental contexts and their disruption in disease.

Extracellular Vesicles in Hepatobiliary Health and Disease

Extracellular vesicles (EVs) are membrane-bound nanoparticles released by cells and are an important means of intercellular communication in physiological and pathological states. We provide an overview of recent advances in the understanding of EV biogenesis, cargo selection, recipient cell effects, and key considerations in isolation and characterization techniques. Studies on the physiological role of EVs have relied on cell-based model systems due to technical limitations of studying endogenous nanoparticles in vivo . Several recent studies have elucidated the mechanistic role of EVs in liver diseases, including nonalcoholic fatty liver disease, viral hepatitis, cholestatic liver disease, alcohol-associated liver disease, acute liver injury, and liver cancers. Employing disease models and human samples, the biogenesis of lipotoxic EVs downstream of endoplasmic reticulum stress and microvesicles via intracellular activation stress signaling are discussed in detail. The diverse cargoes of EVs including proteins, lipids, and nucleic acids can be enriched in a disease-specific manner. By carrying diverse cargo, EVs can directly confer pathogenic potential, for example, recruitment and activation of monocyte-derived macrophages in NASH and tumorigenicity and chemoresistance in hepatocellular carcinoma. We discuss the pathogenic role of EVs cargoes and the signaling pathways activated by EVs in recipient cells. We review the literature that EVs can serve as biomarkers in hepatobiliary diseases. Further, we describe novel approaches to engineer EVs to deliver regulatory signals to specific cell types, and thus use them as therapeutic shuttles in liver diseases. Lastly, we identify key lacunae and future directions in this promising field of discovery and development. © 2023 American Physiological Society. Compr Physiol 13:4631-4658, 2023.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

Exomap1 mouse: a transgenic model for in vivo studies of exosome biology

Exosomes are small extracellular vesicles (sEVs) of ~30-150 nm in diameter that have the same topology as the cell, are enriched in selected exosome cargo proteins, and play important roles in health and disease. To address large unanswered questions regarding exosome biology in vivo, we created the exomap1 transgenic mouse model. In response to Cre recombinase, exomap1 mice express HsCD81mNG, a fusion protein between human CD81, the most highly enriched exosome protein yet described, and the bright green fluorescent protein mNeonGreen. As expected, cell type-specific expression of Cre induced the cell type-specific expression of HsCD81mNG in diverse cell types, correctly localized HsCD81mNG to the plasma membrane, and selectively loaded HsCD81mNG into secreted vesicles that have the size (~80 nm), topology (outside out), and content (presence of mouse exosome markers) of exosomes. Furthermore, mouse cells expressing HsCD81mNG released HsCD81mNG-marked exosomes into blood and other biofluids. Using high-resolution, single-exosome analysis by quantitative single molecule localization microscopy, we show here that that hepatocytes contribute ~15% of the blood exosome population whereas neurons contribute <1% of blood exosomes. These estimates of cell type-specific contributions to blood EV population are consistent with the porosity of liver sinusoidal endothelial cells to particles of ~50-300 nm in diameter, as well as with the impermeability of blood-brain and blood-neuron barriers to particles >5 nm in size. Taken together, these results establish the exomap1 mouse as a useful tool for in vivo studies of exosome biology, and for mapping cell type-specific contributions to biofluid exosome populations. In addition, our data confirm that CD81 is a highly-specific marker for exosomes and is not enriched in the larger microvesicle class of EVs.

Role of Bile-Derived Extracellular Vesicles in Hepatocellular Proliferation after Partial Hepatectomy in Rats

Although liver regeneration has been extensively studied, the effects of bile-derived extracellular vesicles (bile EVs) on hepatocytes has not been elucidated. We examined the influence of bile EVs, collected from a rat model of 70% partial hepatectomy (PH), on hepatocytes. We produced bile-duct-cannulated rats. Bile was collected over time through an extracorporeal bile duct cannulation tube. Bile EVs were extracted via size exclusion chromatography. The number of EVs released into the bile per liver weight 12 h after PH significantly increased. Bile EVs collected 12 and 24 h post-PH, and after sham surgery (PH12-EVs, PH24-EVs, sham-EVs) were added to the rat hepatocyte cell line, and 24 h later, RNA was extracted and transcriptome analysis performed. The analysis revealed that more upregulated/downregulated genes were observed in the group with PH24-EVs. Moreover, the gene ontology (GO) analysis focusing on the cell cycle revealed an upregulation of 28 types of genes in the PH-24 group, including genes that promote cell cycle progression, compared to the sham group. PH24-EVs induced hepatocyte proliferation in a dose-dependent manner in vitro, whereas sham-Evs showed no significant difference compared to the controls. This study revealed that post-PH bile Evs promote the proliferation of the hepatocytes, and genes promoting cell cycles are upregulated in hepatocytes.

Multifunctional Milk-Derived Small Extracellular Vesicles and Their Biomedical Applications

In recent years, small extracellular vesicles (sEVs) have been regarded as the next generation of novel delivery systems after lipid nanoparticles because of their advantages and huge prospects in drug delivery. Studies have shown that sEVs are abundant in milk and therefore can be a large and economical source of sEVs. Natural milk-derived small extracellular vesicles (msEVs) have important functions such as immune regulation, anti-bacterial infection, anti-oxidative, etc., and play a beneficial role in human health at multiple levels, including intestinal health, bone/muscle metabolism, and microbiota regulation. In addition, because they can pass the gastrointestinal barrier and have low immunogenicity, good biocompatibility, and stability, msEVs are considered a crucial oral drug delivery vehicle. Moreover, msEVs can be further engineered for targeted delivery to prolong the circulation time or enhance local drug concentrations. However, msEVs separation and purification, complex contents, and quality control hinder their application in drug delivery. This paper provides a comprehensive review of the biogenesis and characteristics, isolation and purification, composition, loading methods, and function of msEVs, based on which their applications in biomedical fields are further explored.

Progress in Tuberous Sclerosis Complex Renal Disease

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects both fetal development and postnatal tissue growth, resulting in altered brain structures and a tumor predisposition syndrome. Although every organ system is affected by the disease, kidney involvement is a leading cause of death in adults with TSC. Over the past decade, significant progress has been made in understanding the renal disease. This review focuses on the cystic and solid renal lesions in TSC, including their pathobiology and treatment.

Potential roles of extracellular vesicles as a noninvasive tool for prenatal genetic diagnosis

The rate of infertility is increasing owing to genetic and environmental factors. Consequently, assisted reproductive technology has been introduced as an alternative. Bearing in mind the global trend toward the transfer of only one embryo, there is an increasing trend for assessing embryo quality before transfer through prenatal genetic diagnosis (PGD) tests. This ensures that the best-quality embryos are implanted into the uterus. In the in vitro fertilization cycle, PGD is not only used for diseases or quality checks before embryo freezing but also for evaluating unfortunate risks, such as aneuploidy, signs of early abortions, and preterm birth. However, traditional preimplantation genetic testing and screening approaches are invasive and harm the health of both the mother and embryo, raising the risk of miscarriage. In the last decade, embryonic extracellular vesicles (EVs) have been investigated and have emerged as a promising diagnostic tool. In this mini-review, we address the use of EVs as a noninvasive biomarker in PGD to test for biological hazards within the embryo without invading its cells. We summarize the state-of-the-art in the use of the embryo's EV content, genomic DNA, messenger RNA, and microRNA in the spent culture medium and their relationship with embryo quality, successful implantation, and pregnancy.

Stem Cell-derived Extracellular Vesicles: A Promising Nano Delivery Platform to the Brain?

A very important cause of the frustration with drug therapy for central nervous system (CNS) diseases is the failure of drug delivery. The blood-brain barrier (BBB) prevents most therapeutic molecules from entering the brain while maintaining CNS homeostasis. Scientists are keen to develop new brain drug delivery systems to solve this dilemma. Extracellular vesicles (EVs), as a class of naturally derived nanoscale vesicles, have been extensively studied in drug delivery due to their superior properties. This review will briefly present current brain drug delivery strategies, including invasive and non-invasive techniques that target the brain, and the application of nanocarriers developed for brain drug delivery in recent years, especially EVs. The cellular origin of EVs affects the surface protein, size, yield, luminal composition, and other properties of EVs, which are also crucial in determining whether EVs are useful as drug carriers. Stem cell-derived EVs, which inherit the properties of parental cells and avoid the drawbacks of cell therapy, have always been favored by researchers. Thus, in this review, we will focus on the application of stem cell-derived EVs for drug delivery in the CNS. Various nucleic acids, proteins, and small-molecule drugs are loaded into EVs with or without modification and undergo targeted delivery to the brain to achieve their therapeutic effects. In addition, the challenges facing the clinical application of EVs as drug carriers will also be discussed. The directions of future efforts may be to improve drug loading efficiency and precise targeting.

Prominin-1 promotes restitution of the murine extrahepatic biliary luminal epithelium following cholestatic liver injury

BACKGROUND AND AIMS

Restitution of the extrahepatic biliary luminal epithelium in cholangiopathies is poorly understood. Prominin-1 (Prom1) is a key component of epithelial ciliary body of stem/progenitor cells. Given that intrahepatic Prom1-expressing progenitor cells undergo cholangiocyte differentiation, we hypothesized that Prom1 may promote restitution of the extrahepatic bile duct (EHBD) epithelium following injury.

APPROACH AND RESULTS

Utilizing various murine biliary injury models, we identified Prom1-expressing cells in the peribiliary glands of the EHBD. These Prom1-expressing cells are progenitor cells which give rise to cholangiocytes as part of the normal maintenance of the EHBD epithelium. Following injury, these cells proliferate significantly more rapidly to re-populate the biliary luminal epithelium. Null mutation of Prom1 leads to significantly >10-fold dilated peribiliary glands following rhesus rotavirus-mediated biliary injury. Cultured organoids derived from Prom1 knockout mice are comprised of biliary progenitor cells with altered apical-basal cellular polarity, significantly fewer and shorter cilia, and decreased organoid proliferation dynamics consistent with impaired cell motility.

CONCLUSIONS

We, therefore, conclude that Prom1 is involved in biliary epithelial restitution following biliary injury in part through its role in supporting cell polarity.

Antimicrobial and Immunomodulatory Potential of Cow Colostrum Extracellular Vesicles (ColosEVs) in an Intestinal In Vitro Model

Extracellular Vesicles (EVs) are nano-sized double-lipid-membrane-bound structures, acting mainly as signalling mediators between distant cells and, in particular, modulating the immune response and inflammation of targeted cells. Milk and colostrum contain high amounts of EVs that could be exploited as alternative natural systems in antimicrobial fighting. The aim of this study is to evaluate cow colostrum-derived EVs (colosEVs) for their antimicrobial, anti-inflammatory and immunomodulating effects in vitro to assess their suitability as natural antimicrobial agents as a strategy to cope with the drug resistance problem. ColosEVs were evaluated on a model of neonatal calf diarrhoea caused by Escherichia coli infection, a livestock disease where antibiotic therapy often has poor results. Colostrum from Piedmontese cows was collected within 24 h of calving and colosEVs were immediately isolated. IPEC-J2 cell line was pre-treated with colosEVs for 48 h and then infected with EPEC/NTEC field strains for 2 h. Bacterial adherence and IPEC-J2 gene expression analysis (RT-qPCR) of CXCL8, DEFB1, DEFB4A, TLR4, TLR5, NFKB1, MYD88, CGAS, RIGI and STING were evaluated. The colosEVs pre-treatment significantly reduced the ability of EPEC/NTEC strains to adhere to cell surfaces (p = 0.006), suggesting a role of ColosEVs in modulating host−pathogen interactions. Moreover, our results showed a significant decrease in TLR5 (p < 0.05), CGAS (p < 0.05) and STING (p < 0.01) gene expression in cells that were pre-treated with ColosEVs and then infected, thus highlighting a potential antimicrobial activity of ColosEVs. This is the first preliminarily study investigating ColosEV immunomodulatory and anti-inflammatory effects on an in vitro model of neonatal calf diarrhoea, showing its potential as a therapeutic and prophylactic tool.

Extracellular Vesicles from Animal Milk: Great Potentialities and Critical Issues

Other than representing the main source of nutrition for newborn mammals, milk delivers a sophisticated signaling system from mother to child that promotes postnatal health. The bioactive components transferred through the milk intake are important for the development of the newborn immune system and include oligosaccharides, lactoferrin, lysozyme, α-La, and immunoglobulins. In the last 15 years, a pivotal role in this mother-to-child exchange has been attributed to extracellular vesicles (EVs). EVs are micro- and nanosized structures enclosed in a phospholipidic double-layer membrane that are produced by all cell types and released in the extracellular environment, reaching both close and distant cells. EVs mediate the intercellular cross-talk from the producing to the receiving cell through the transfer of molecules contained within them such as proteins, antigens, lipids, metabolites, RNAs, and DNA fragments. The complex cargo can induce a wide range of functional modulations in the recipient cell (i.e., anti-inflammatory, immunomodulating, angiogenetic, and pro-regenerative modulations) depending on the type of producing cells and the stimuli that these cells receive. EVs can be recovered from every biological fluid, including blood, urine, bronchoalveolar lavage fluid, saliva, bile, and milk, which is one of the most promising scalable vesicle sources. This review aimed to present the state-of-the-art of animal-milk-derived EV (mEV) studies due to the exponential growth of this field. A focus on the beneficial potentialities for human health and the issues of studying vesicles from milk, particularly for the analytical methodologies applied, is reported.

Extracellular vesicles biogenesis, isolation, manipulation and genetic engineering for potential in vitro and in vivo therapeutics: An overview

The main goals of medicine consist of early detection and effective treatment of different diseases. In this regard, the rise of exosomes as carriers of natural biomarkers has recently attracted a lot of attention and managed to shed more light on the future of early disease diagnosis methods. Here, exosome biogenesis, its role as a biomarker in metabolic disorders, and recent advances in state-of-art technologies for exosome detection and isolation will be reviewed along with future research directions and challenges regarding the manipulation and genetic engineering of exosomes for potential in vitro and in vivo disease diagnosis approaches.

Clinical impact of bile-derived exosomal microRNAs as novel diagnostic and prognostic biomarkers for biliary tract cancers

Sampling of bile juice during endoscopic retrograde cholangiopancreatography (ERCP) has potential benefit of being amenable to the identification of novel biomarkers in liquid biopsy. This study reports the results of a global investigation of exosomal microRNAs (miRNAs) in bile to identify potential biomarkers for biliary tract cancers (BTCs). Eighty-eight bile samples collected during ERCP (45 BTC and 43 noncancer control samples) were enrolled in this study. Eleven BTC samples and nine control samples were assigned as the discovery set. Exosomes in bile and serum samples were collected using a glass membrane column with size-controlled macroporous glass (MPG), and exosomal miRNA expression profiles were evaluated using comprehensive miRNA microarray analysis (3D-Gene). For validation, exosomal miRNA in the bile samples of 34 BTCs and 34 controls were comprehensively evaluated using 3D-Gene. In the discovery set, eight exosomal miRNAs in bile were identified as significant aberrant expression markers, while no miRNA with aberrant expression in serum was identified. In a comparison of the discovery and validation sets, miR-451a and miR-3619-3p were identified as reproducible upregulated markers, and the combination of the two bile miRNAs showed an excellent area under the curve (0.819) value for diagnosing BTCs. In addition, high miR-3619-3p expression in bile reflects poorer prognosis of BTCs (hazard ratio = 2.89). The MPG-extracted exosomal miRNAs in bile aspirated during ERCP provide a convenient new approach for diagnosing biliary diseases. Bile-derived miRNA analysis with miR-451a and miR-3619-3p represents a potentially valuable diagnostic strategy for identifying BTCs as well as a predictive indicator of BTC prognosis.

Identification of the Level of Exosomal Protein by Parallel Reaction Monitoring Technology in HCC Patients

PURPOSE

Reliable biomarkers for the diagnosis and differential diagnosis of various stages of liver cancer are lacking. In this study, we aim to detect the levels of differentially expressed proteins (DEPs) in serum exosomes of patients with different liver diseases using a sensitive method.

PATIENTS AND METHODS

Exosomes were purified and validated. The expression of DEPs in exosomes from patients with chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC) was validated by parallel reaction monitoring (PRM) technology and Western blotting, and the biological functions were analyzed by bioinformatics analysis.

RESULTS

A total of 11 DEPs were identified by PRM technology. Significantly higher level of haptoglobin (Hp) was detected in HCC patients as compared to LC and CHB patients. HCC patients had a significantly lower level of transthyretin (TTR) in the patients with CHB. Among the patients with HCC who undertaken surgery, the postoperative levels of CRP, SERPINA3 and Heparin cofactor 2 (SERPIND1) were significantly reduced compared to their respective preoperative levels.

CONCLUSION

Hp and TTR may be potential markers for early diagnosis of HCC. CRP, SERPINA3 and SERPIND1 may serve as potential prognostic indicators for HCC patients undertaken surgery.

Shedding of ciliary vesicles at a glance

Cilia sense and transduce sensory stimuli, homeostatic cues and developmental signals by orchestrating signaling reactions. Extracellular vesicles (EVs) that bud from the ciliary membrane have well-studied roles in the disposal of excess ciliary material, most dramatically exemplified by the shedding of micrometer-sized blocks by photoreceptors. Shedding of EVs by cilia also affords cells with a powerful means to shorten cilia. Finally, cilium-derived EVs may enable cell-cell communication in a variety of organisms, ranging from single-cell parasites and algae to nematodes and vertebrates. Mechanistic understanding of EV shedding by cilia is an active area of study, and future progress may open the door to testing the function of ciliary EV shedding in physiological contexts. In this Cell Science at a Glance and the accompanying poster, we discuss the molecular mechanisms that drive the shedding of ciliary material into the extracellular space, the consequences of shedding for the donor cell and the possible roles that ciliary EVs may have in cell non-autonomous contexts.

The Role of Extracellular Vesicles in Liver Pathogenesis

Extracellular vesicles (EVs) are generated by cells in the form of exosomes, microvesicles, and apoptotic bodies. They can be taken up by neighboring cells, and their contents can have functional impact on the cells that engulf them. As the mediators of intercellular communication, EVs can play important roles in both physiological and pathologic contexts. In addition, early detection of EVs in different body fluids may offer a sensitive diagnostic tool for certain diseases, such as cancer. Furthermore, targeting specific EVs may also become a promising therapeutic approach. This review summarizes the latest findings of EVs in the field of liver research, with a focus on the different contents of the EVs and their impact on liver function and on the development of inflammation, fibrosis, and tumor in the liver. The goal of this review is to provide a succinct account of the various molecules that can mediate the function of EVs so the readers may apply this knowledge to their own research.

Characterising extracellular vesicles from individual low volume cerebrospinal fluid samples, isolated by SmartSEC

Extracellular vesicles (EVs) are suggested to have a role in the progression of neurodegeneration, and are able to transmit pathological proteins from one cell to another. One of the biofluids from which EVs can be isolated is cerebrospinal fluid (CSF). However, so far, few studies have been performed on small volumes of CSF. Since pooling of patient samples possibly leads to the loss of essential individual patient information, and CSF samples are precious, it is important to have efficient techniques for the isolation of EVs from smaller volumes. In this study, the SmartSEC HT isolation kit from System Biosciences has been evaluated for this purpose. The SmartSEC HT isolation kit was used for isolation of EVs from 500 μL starting volumes of CSF, resulting in two possible EV fractions of 500 μL. Both fractions were characterised and compared to one another using a whole range of characterisation techniques. Results indicated the presence of EVs in both fractions, albeit fraction 1 showed more reproducible results over the different characterisation methods. For example, CMG (CellMask Green membrane stain) fluorescence nanotracking analysis (NTA), ExoView, and the particles/μg ratio demonstrated a clear difference between fraction 1 and 2, where fraction 1 came out as the one where most EVs were eluted with the least contamination. In the other methods, this difference was less noticeable. We successfully performed complementary characterisation tests using only 500 μL of CSF starting volume, and, conclude that fraction 1 consisted of sufficiently pure EVs for further biomarker studies. This means that future EV extractions may be based upon smaller CSF quantities, such as from individual patients. In that way, patient samples do not have to be pooled and individual patient information can be included in forthcoming studies, potentially linking EV content, size and distribution to individualised neurological diagnoses.

Bile-derived exosome noncoding RNAs as potential diagnostic and prognostic biomarkers for cholangiocarcinoma

Background

Cholangiocarcinoma (CCA) is one of the most aggressive malignancies, lacking novel diagnostic and prognostic biomarkers. Exosome noncoding RNAs (ncRNA) were previously proposed as a potential source of biomarkers in several cancers. This study aimed to interpret the value of specific bile-derived ncRNA as predictors for early diagnosis and prognosis of CCA.

Methods

We recruited 100 patients who received endoscopic retrograde cholangiopancreatography at our hospital for bile duct obstruction due to CCA (n = 50) and biliary stone (n = 50). They were further divided into training set and validation set (3:2). A panel of CCA-specific ncRNAs including 5 miRNAs (PMID: 30165035) and 2 lncRNAs (PMID: 29050258) were detected in both serum and bile exosomes. The diagnostic accuracy was assessed using the area under the receiver operating characteristic curve. Logistic analysis was used to classify the potential predictors of CCA and further establish the diagnostic model. And the prognostic value of the ncRNAs was also assessed.

Results

Exosomes were successfully collected from bile and serum. Exosomal miR-141-3p, miR-200a-3p, miR-200c-3p in serum and bile, as well as miR-200b-3p and ENST00000588480.1 in bile showed AUCs of >0.70 in the diagnosis of CCA. Bile exosomal miR-200c-3p displayed the best diagnostic value with the AUC of 0.87. The combination of serum CA19-9 into the model could increase the AUC to 0.906. Bile exosomal miR-200a-3p and miR-200c-3p were found to be independent predictors of CCA. Among exosomal ncRNAs in human bile and blood, 3 (serum and bile exosomal miR-200c-3p, bile exosomal miR-200a-3p) showed significant value in predicting cancer recurrence and 1 (serum exosomal miR-200c-3p) had great predictive ability of cancer death. High levels of serum exosomal miR-200c-3p showed unfavorable tumor-free survival and overall survival.

Conclusion

The bile exosomal miR-200 family, particularly miR-200c-3p, was verified to be a potential biomarker for the early detection of CCA. The diagnostic ability of exosomal ncRNAs in human bile is better than that in blood. Moreover, high levels of bile exosomal miR-200a-3p, miR-200c-3p, and serum exosomal miR-200c-3p represented adverse clinical outcomes.

EV duty vehicles: Features and functions of ciliary extracellular vesicles

The primary cilium is a microtubule-based organelle that extends from a basal body at the surface of most cells. This antenna is an efficient sensor of the cell micro-environment and is instrumental to the proper development and homeostatic control of organs. Recent compelling studies indicate that, in addition to its role as a sensor, the primary cilium also emits signals through the release of bioactive extracellular vesicles (EVs). While some primary-cilium derived EVs are released through an actin-dependent ectocytosis and are called ectosomes (or large EVs, 350–500 nm), others originate from the exocytosis of multivesicular bodies and are smaller (small EVs, 50–100 nm). Ciliary EVs carry unique signaling factors, including protein markers and microRNAs (miRNAs), and participate in intercellular communication in different organism models. This review discusses the mechanism of release, the molecular features, and functions of EVs deriving from cilia, based on the existing literature.

A shared, stochastic pathway mediates exosome protein budding along plasma and endosome membranes

Exosomes are small extracellular vesicles of ∼30 to 150 nm that are secreted by all cells, abundant in all biofluids, and play important roles in health and disease. However, details about the mechanism of exosome biogenesis are unclear. Here, we carried out a cargo-based analysis of exosome cargo protein biogenesis in which we identified the most highly enriched exosomal cargo proteins and then followed their biogenesis, trafficking, and exosomal secretion to test different hypotheses for how cells make exosomes. We show that exosome cargo proteins bud from cells (i) in exosome-sized vesicles regardless of whether they are localized to plasma or endosome membranes, (ii) ∼5-fold more efficiently when localized to the plasma membrane, (iii) ∼5-fold less efficiently when targeted to the endosome membrane, (iv) by a stochastic process that leads to ∼100-fold differences in their abundance from one exosome to another, and (v) independently of small GTPase Rab27a, the ESCRT complex–associated protein Alix, or the cargo protein CD63. Taken together, our results demonstrate that cells use a shared, stochastic mechanism to bud exosome cargoes along the spectrum of plasma and endosome membranes and far more efficiently from the plasma membrane than the endosome. Our observations also indicate that the pronounced variation in content between different exosome-sized vesicles is an inevitable consequence of a stochastic mechanism of small vesicle biogenesis, that the origin membrane of exosome-sized extracellular vesicles simply cannot be determined, and that most of what we currently know about exosomes has likely come from studies of plasma membrane-derived vesicles.

Cellular Homeostasis and Repair in the Biliary Tree

During biliary tree homeostasis, BECs are largely in a quiescent state and their turnover is slow for maintaining normal tissue homeostasis. BTSCs continually replenish new BECs in the luminal surface of EHBDs. In response to various types of biliary injuries, distinct cellular sources, including HPCs, BTSCs, hepatocytes, and BECs, repair or regenerate the injured bile duct. BEC, biliary epithelial cell; BTSC, biliary tree stem/progenitor cell; EHBD, extrahepatic bile ducts; HPC, hepatic progenitor cell.The biliary tree comprises intrahepatic bile ducts and extrahepatic bile ducts lined with epithelial cells known as biliary epithelial cells (BECs). BECs are a common target of various cholangiopathies for which there is an unmet therapeutic need in clinical hepatology. The repair and regeneration of biliary tissue may potentially restore the normal architecture and function of the biliary tree. Hence, the repair and regeneration process in detail, including the replication of existing BECs, expansion and differentiation of the hepatic progenitor cells and biliary tree stem/progenitor cells, and transdifferentiation of the hepatocytes, should be understood. In this paper, we review biliary tree homeostasis, repair, and regeneration and discuss the feasibility of regenerative therapy strategies for cholangiopathy treatment.

Roles of Non-Coding RNAs in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an autoimmune-mediated chronic cholestatic liver disease, fatigue, and skin itching are the most common clinical symptoms. Its main pathological feature is the progressive damage and destruction of bile duct epithelial cells. Non-coding RNA (NcRNA, mainly including microRNA, long non-coding RNA and circular RNA) plays a role in the pathological and biological processes of various diseases, especially autoimmune diseases. Many validated ncRNAs are expected to be biomarkers for the diagnosis or treatment of PBC. This review will elucidate the pathogenesis of PBC and help to identify potential ncRNA biomarkers for PBC.

Two Cases With Neonatal Cholestasis and Renal Disorders Due to DCDC2 Mutation

Ciliopathies are a heterogeneous group of diseases that are observed after deterioration of the ciliary structures on the cell surface that facilitate communication with the environment. Both liver and kidney involvement are frequently observed in this disease. Recently, a doublecortin domain containing protein 2 (DCDC2) mutation in a ciliopathy disease group was identified. Here, we present 2 patients with this mutation and with neonatal cholestasis and renal involvement.

Single Gene Mutations in Pkd1 or Tsc2 Alter Extracellular Vesicle Production and Trafficking

Simple Summary

Extracellular vesicles shed from primary cilia may be involved in renal cystogenesis. The disruption of the Pkd1 gene in our cell culture system increased the production of EVs in a similar way that occurs when the Tsc2 gene is disrupted. Disruption of the primary cilia depresses EV production, and this may be the reason that the combined Kif3A/Pkd1 mutant mouse has a less severe phenotype than the Pkd1 mutant alone. We initiated studies aimed at understanding the renal trafficking of renally-derived EVs and found that single gene disruptions can alter the EV kinetics based on dye tracking studies. These results raise the possibility that EV features, such as cargo, dose, tissue half-life, and targeting, may be involved in the disease process, and these features may also be fertile targets for diagnostic, prognostic, and therapeutic investigation.

Abstract

Patients with autosomal dominant polycystic kidney disease (ADPKD) and tuberous sclerosis complex (TSC) are born with normal or near-normal kidneys that later develop cysts and prematurely lose function. Both renal cystic diseases appear to be mediated, at least in part, by disease-promoting extracellular vesicles (EVs) that induce genetically intact cells to participate in the renal disease process. We used centrifugation and size exclusion chromatography to isolate the EVs for study. We characterized the EVs using tunable resistive pulse sensing, dynamic light scattering, transmission electron microscopy, and Western blot analysis. We performed EV trafficking studies using a dye approach in both tissue culture and in vivo studies. We have previously reported that loss of the Tsc2 gene significantly increased EV production and here demonstrate that the loss of the Pkd1 gene also significantly increases EV production. Using a cell culture system, we also show that loss of either the Tsc2 or Pkd1 gene results in EVs that exhibit an enhanced uptake by renal epithelial cells and a prolonged half-life. Loss of the primary cilia significantly reduces EV production in renal collecting duct cells. Cells that have a disrupted Pkd1 gene produce EVs that have altered kinetics and a prolonged half-life, possibly impacting the duration of the EV cargo effect on the recipient cell. These results demonstrate the interplay between primary cilia and EVs and support a role for EVs in polycystic kidney disease pathogenesis.

Novel approaches in search for biomarkers of cholangiocarcinoma

Cholangiocarcinoma (CCA) arises from the ductular epithelium of the biliary tree, either within the liver (intrahepatic CCA) or more commonly from the extrahepatic bile ducts (extrahepatic CCA). This disease has a poor prognosis and a growing worldwide prevalence. The poor outcomes of CCA are partially explained by the fact that a final diagnosis is challenging, especially the differential diagnosis between hepatocellular carcinoma and intrahepatic CCA, or distal CCA and pancreatic head adenocarcinoma. Most patients present with an advanced disease, unresectable disease, and there is a lack in non-surgical therapeutic modalities. Not least, there is an acute lack of prognostic biomarkers which further complicates disease management. Therefore, there is a dire need to find alternative diagnostic and follow-up pathways that can lead to an accurate result, either singlehandedly or combined with other methods. In the "-omics" era, this goal can be attained by various means, as it has been successfully demonstrated in other primary tumors. Numerous variants can reach a biomarker status ranging from circulating nucleic acids to proteins, metabolites, extracellular vesicles, and ultimately circulating tumor cells. However, given the relatively heterogeneous data, extracting clinical meaning from the inconsequential noise might become a tall task. The current review aims to navigate the nascent waters of the non-invasive approach to CCA and provide an evidence-based input to aid clinical decisions and provide grounds for future research.

Characteristics of Extracellular Vesicles and Preclinical Testing Considerations Prior to Clinical Applications

Cell therapy products have significant limitations, such as storage instability, difficulties with transportation, and toxicity issues such as tumorigenicity and immunogenicity. Extracellular vesicles (EVs) secreted from cells show potential for therapeutic agent development. EVs have not been widely examined as investigational drugs, and non-clinical studies for the clinical approval of EV therapeutic agents are challenging. EVs contain various materials, such as DNA, cellular RNA, cytokines, chemokines, and microRNAs, but do not proliferate or divide like cells, thus avoiding safety concerns related to tumorigenicity. However, the constituents of EVs may induce the proliferation of normal cells; therefore, the suitability of vesicles should be verified through non-clinical safety evaluations. In this review, the findings of non-clinical studies on EVs are summarized. We describe non-clinical toxicity studies of EVs, which should be useful for researchers who aim to develop these vesicles into therapeutic agents. A new method for evaluating the immunotoxicity and tumorigenicity of EVs should also be developed.

Exosomes as bio-inspired nanocarriers for RNA delivery: preparation and applications

Nanocarriers as drug/biomolecule delivery systems have been significantly developed during recent decades. Given the stability, reasonable delivery efficiency, and safety of nanocarriers, there are several barriers in the fulfillment of successful clinical application of these delivery systems. These challenges encouraged drug delivery researchers to establish innovative nanocarriers with longer circulation time, high stability, and high compatibility. Exosomes are extracellular nanometer-sized vesicles released through various cells. These vesicles serve as nanocarriers, possessing great potential to overcome some obstacles encountered in gene and drug delivery due to their natural affinity to recipient cells and the inherent capability to shuttle the genes, lipids, proteins, and RNAs between cells. So far, there has been a lot of valuable research on drug delivery by exosomes, but research on RNA delivery, especially mRNA, is very limited. Since mRNA-based vaccines and therapies have recently gained particular prominence in various diseases, it is essential to find a suitable delivery system due to the large size and destructive nature of these nucleic acids. That's why we're going to take a look at the unique features of exosomes and their isolation and loading methods, to embrace this idea that exosome-mediated mRNA-based therapies would be introduced as a very efficient strategy in disease treatment within the near future.

Mesenchymal Stem-Cell Derived Exosome Therapy as a Potential Future Approach for Treatment of Male Infertility Caused by Chlamydia Infection

Some microbial sexually transmitted infections (STIs) have adverse effects on the reproductive tract, sperm function, and male fertility. Given that STIs are often asymptomatic and cause major complications such as urogenital inflammation, fibrosis, and scarring, optimal treatments should be performed to prevent the noxious effect of STIs on male fertility. Among STIs, Chlamydia trachomatis is the most common asymptomatic preventable bacterial STI. C. trachomatis can affect both sperm and the male reproductive tract. Recently, mesenchymal stem cells (MSCs) derived exosomes have been considered as a new therapeutic medicine due to their immunomodulatory, anti-inflammatory, anti-oxidant, and regenerative effects without consequences through the stem cell transplantation based therapies. Inflammation of the genital tract and sperm dysfunction are the consequences of the microbial infections, especially Chlamydia trachomatis. Exosome therapy as a noninvasive approach has shown promising results on the ability to regenerate the damaged sperm and treating asthenozoospermia. Recent experimental methods may be helpful in the novel treatments of male infertility. Thus, it is demonstrated that exosomes play an important role in preventing the consequences of infection, and thereby preventing inflammation, reducing cell damage, inhibiting fibrogenesis, and reducing scar formation. This review aimed to overview the studies about the potential therapeutic roles of MSCs-derived exosomes on sperm abnormalities and male infertility caused by STIs.

Tumor-derived exosomes: Key players in non-small cell lung cancer metastasis and their implication for targeted therapy

Exosomes represent extracellular vesicles of endocytic origin ranging from 30 to 100 nm that are released by most of eukaryotic cells and can be found in body fluids. These vesicles in carrying DNA, RNA, microRNA (miRNA), Long noncoding RNA, proteins, and lipids serve as intercellular communicators. Due to their role in crosstalk between tumor cells and mesenchymal stroma cells, they are vital for tumor growth, progression, and anticancer drug resistance. Lung cancer is a global leading cause of cancer-related deaths with 5-year survival rates of about 7% in patients with distant metastasis. Although the implementation of targeted therapy has improved the clinical outcome of nonsmall cell lung cancer, drug resistance remains a major obstacle. Lung tumor-derived exosomes (TDEs) conveying molecular information from tumor cells to their neighbor cells or cells at distant sites of the body activate the tumor microenvironment (TME) and facilitate tumor metastasis. Exosomal miRNAs are also considered as noninvasive biomarkers for early diagnosis of lung cancer. This review summarizes the influence of lung TDEs on the TME and metastasis. Their involvement in targeted therapy resistance and potential clinical applications are discussed. Additionally, challenges encountered in the development of exosome-based therapeutic strategies are addressed.

Biliary Atresia - emerging diagnostic and therapy opportunities

Biliary Atresia is a devastating pediatric cholangiopathy affecting the bile ducts of the liver. In this review, we describe recent progress in the understanding of liver development with a focus on cholangiocyte differentiation and how use of technical platforms, including rodent, zebrafish and organoid models, advances our understanding of Biliary Atresia. This is followed by a description of potential pathomechanisms, such as autoimmune responses, inflammation, disturbed apical-basal cell polarity, primary cilia dysfunction as well as beta-amyloid accumulation. Finally, we describe current and emerging diagnostic opportunities and recent translation breakthroughs for Biliary Atresia in the area of emerging therapy development, including immunomodulation and organoid-based systems for liver and bile duct repair.

Advanced preclinical models for evaluation of drug-induced liver injury - consensus statement by the European Drug-Induced Liver Injury Network [PRO-EURO-DILI-NET]

Drug-induced liver injury (DILI) is a major cause of acute liver failure (ALF) and one of the leading indications for liver transplantation in Western societies. Given the wide use of both prescribed and over the counter drugs, DILI has become a major health issue for which there is a pressing need to find novel and effective therapies. Although significant progress has been made in understanding the molecular mechanisms underlying DILI, our incomplete knowledge of its pathogenesis and inability to predict DILI is largely due to both discordance between human and animal DILI in preclinical drug development and a lack of models that faithfully recapitulate complex pathophysiological features of human DILI. This is exemplified by the hepatotoxicity of acetaminophen (APAP) overdose, a major cause of ALF because of its extensive worldwide use as an analgesic. Despite intensive efforts utilising current animal and in vitro models, the mechanisms involved in the hepatotoxicity of APAP are still not fully understood. In this expert Consensus Statement, which is endorsed by the European Drug-Induced Liver Injury Network, we aim to facilitate and outline clinically impactful discoveries by detailing the requirements for more realistic human-based systems to assess hepatotoxicity and guide future drug safety testing. We present novel insights and discuss major players in APAP pathophysiology, and describe emerging in vitro and in vivo pre-clinical models, as well as advanced imaging and in silico technologies, which may improve prediction of clinical outcomes of DILI.

Biological Functions Driven by mRNAs Carried by Extracellular Vesicles in Cancer

Extracellular vesicles (EVs), including exosomes and microvesicles, are extracellular nanovesicles released by most cells. EVs play essential roles in intercellular communication via the transport of a large variety of lipids, proteins, and nucleic acids to recipient cells. Nucleic acids are the most commonly found molecules inside EVs, and due to their small size, microRNAs and other small RNAs are the most abundant nucleic acids. However, longer molecules, such as messenger RNAs (mRNAs), have also been found. mRNAs encapsulated within EVs have been shown to be transferred to recipient cells and translated into proteins, altering the behavior of the cells. Secretion of EVs is maintained not only through multiple normal physiological conditions but also during aberrant pathological conditions, including cancer. Recently, the mRNAs carried by EVs in cancer have attracted great interest due to their broad roles in tumor progression and microenvironmental remodeling. This review focuses on the biological functions driven by mRNAs carried in EVs in cancer, which include supporting tumor progression by activating cancer cell growth, migration, and invasion; inducing microenvironmental remodeling via hypoxia, angiogenesis, and immunosuppression; and promoting modulation of the microenvironment at distant sites for the generation of a premetastatic niche, collectively inducing metastasis. Furthermore, we describe the potential use of mRNAs carried by EVs as a noninvasive diagnostic tool and novel therapeutic approach.

The mini player with diverse functions: extracellular vesicles in cell biology, disease, and therapeutics

Extracellular vesicles (EVs) are tiny biological nanovesicles ranging from approximately 30-1000 nm in diameter that are released into the extracellular matrix of most cell types and in biofluids. The classification of EVs includes exosomes, microvesicles, and apoptotic bodies, dependent on various factors such as size, markers, and biogenesis pathways. The transition of EV relevance from that of being assumed as a trash bag to be a key player in critical physiological and pathological conditions has been revolutionary in many ways. EVs have been recently revealed to play a crucial role in stem cell biology and cancer progression via intercellular communication, contributing to organ development and the progression of cancer. This review focuses on the significant research progress made so far in the role of the crosstalk between EVs and stem cells and their niche, and cellular communication among different germ layers in developmental biology. In addition, it discusses the role of EVs in cancer progression and their application as therapeutic agents or drug delivery vehicles. All such discoveries have been facilitated by tremendous technological advancements in EV-associated research, especially the microfluidics systems. Their pros and cons in the context of characterization of EVs are also extensively discussed in this review. This review also deliberates the role of EVs in normal cell processes and disease conditions, and their application as a diagnostic and therapeutic tool. Finally, we propose future perspectives for EV-related research in stem cell and cancer biology.

Role of extracellular vesicles in liver diseases and their therapeutic potential

More than eight hundred million people worldwide have chronic liver disease, with two million deaths per year. Recurring liver injury results in fibrogenesis, progressing towards cirrhosis, for which there doesn't exists any cure except liver transplantation. Better understanding of the mechanisms leading to cirrhosis and its complications is needed to develop effective therapies. Extracellular vesicles (EVs) are released by cells and are important for cell-to-cell communication. EVs have been reported to be involved in homeostasis maintenance, as well as in liver diseases. In this review, we present current knowledge on the role of EVs in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, alcohol-associated liver disease, chronic viral hepatitis, primary liver cancers, acute liver injury and liver regeneration. Moreover, therapeutic strategies involving EVs as targets or as tools to treat liver diseases are summarized.

Current understandings of the relationship between extracellular vesicles and cilia

Mammalian cells have a tiny hair-like protrusion on their surface called a primary cilium. Primary cilia are thought to be the antennae for the cells, receiving signals from the environment. In some studies, extracellular vesicles (EVs) were found attached to the surface of the primary cilium. An idea for the phenomenon is that the primary cilium is the receptor for receiving the EVs. Meanwhile, a unicellular organism, Chlamydomonas, which has two long cilia, usually called flagella, release EVs termed ectosomes from the surface of the flagella. Accumulating evidence suggests that the primary cilium also functions as the 'emitter' of EVs. Physiological and pathological impacts are also elucidated for the release of EVs from primary cilia. However, the roles of released cilia-derived EVs remain to be clarified. This review introduces the historical background of the relationship between EVs and cilia, and recent progresses in the research field.

Next-Generation Biomarkers for Cholangiocarcinoma

Simple Summary

Early and non-invasive diagnosis of cholangiocarcinoma (CCA) is still challenging, thus largely contributing to the increased mortality rates observed worldwide. Consequently, several efforts have been made in order to report novel biomarkers for CCA, that would aid on diagnosis and also to predict prognosis and therapy response. We herein aim to provide an in-depth and critical revision on the next-generation biomarkers for CCA that have been recently proposed.

Abstract

The increasing mortality rates of cholangiocarcinoma (CCA) registered during the last decades are, at least in part, a result of the lack of accurate non-invasive biomarkers for early disease diagnosis, making the identification of patients who might benefit from potentially curative approaches (i.e., surgery) extremely challenging. The obscure CCA pathogenesis and associated etiological factors, as well as the lack of symptoms in patients with early tumor stages, highly compromises CCA identification and to predict tumor development in at-risk populations. Currently, CCA diagnosis is accomplished by the combination of clinical/biochemical features, radiological imaging and non-specific serum tumor biomarkers, although a tumor biopsy is still needed to confirm disease diagnosis. Furthermore, prognostic and predictive biomarkers are still lacking and urgently needed. During the recent years, high-throughput omics-based approaches have identified novel circulating biomarkers (diagnostic and prognostic) that might be included in large, international validation studies in the near future. In this review, we summarize and discuss the most recent advances in the field of biomarker discovery in CCA, providing new insights and future research directions.

Bile extracellular vesicles from end-stage liver disease patients show altered microRNA content

BACKGROUND

Extracellular vesicles (EVs) have recently attracted attention as novel diagnostic biomarkers and therapeutic tools. Several reports have correlated blood EVs with liver diseases. However, blood EVs do not reflect the liver state as it contains other systemically circulating EVs. Therefore, we focused on bile EVs, which are secreted directly from the liver, for the identification of potential biomarkers of liver failure.

METHODS

Bile samples were collected from liver transplant recipients (n = 21) diagnosed with end-stage liver disease (ESLD) and donors (normal liver, NL; n = 18) during transplantation. Bile EVs were extracted using ultracentrifugation.

RESULTS

Nanoparticle tracking analysis showed that bile EV concentration was significantly higher in recipients than in donors. Among recipients, bile EV concentration was remarkably higher in those with hepatocellular carcinoma. Next-generation sequencing revealed 461 and 465 types of microRNAs (miRNAs) in donor and recipient bile EVs, respectively, with no significant difference in diversity between the groups. Among 43 high-expression miRNAs, the expression of 86.0% of the miRNAs was higher in the bile EVs of recipients than in those of donors. Quantitative PCR validation showed that the levels of miR-17, miR-92a, miR-25, miR-423, and miR-451a significantly increased in bile EVs of recipients. Levels of miR-17 were remarkably higher in recipients with alcoholic ESLD.

CONCLUSIONS

Secretion of EVs into the bile and their miRNA content increase in the ESLD state. Additionally, miRNA levels in bile EVs are not correlated with those in serum EVs. Bile EVs could be promising novel biomarkers for liver diseases.

Ciliary extracellular vesicles are distinct from the cytosolic extracellular vesicles

Extracellular vesicles (EVs) are cell‐derived membrane vesicles that are released into the extracellular space. EVs encapsulate key proteins and mediate intercellular signalling pathways. Recently, primary cilia have been shown to release EVs under fluid‐shear flow, but many proteins encapsulated in these vesicles have never been identified. Primary cilia are ubiquitous mechanosensory organelles that protrude from the apical surface of almost all human cells. Primary cilia also serve as compartments for signalling pathways, and their defects have been associated with a wide range of human genetic diseases called ciliopathies. To better understand the mechanism of ciliopathies, it is imperative to know the distinctive protein profiles of the differently sourced EVs (cilia vs cytosol). Here, we isolated EVs from ciliated wild‐type (WT) and non‐ciliated IFT88 knockout (KO) mouse endothelial cells using fluid‐shear flow followed by a conventional method of EV isolation. EVs isolated from WT and KO exhibited distinctive sizes. Differences in EV protein contents were studied using liquid chromatography with tandem mass spectrometry (LC‐MS‐MS) and proteomic comparative analysis, which allowed us to classify proteins between ciliary EVs and cytosolic EVs derived from WT and KO, respectively. A total of 79 proteins were exclusively expressed in WT EVs, 145 solely in KO EVs, and 524 in both EVs. Our bioinformatics analyses revealed 29% distinct protein classes and 75% distinct signalling pathways between WT and KO EVs. Based on our statistical analyses and in vitro studies, we identified NADPH‐cytochrome P450 reductase (POR), and CD166 antigen (CD166) as potential biomarkers for ciliary and cytosolic EVs, respectively. Our protein‐protein interaction network analysis revealed that POR, but not CD166, interacted with either established or strong ciliopathy gene candidates. This report shows the unique differences between EVs secreted from cilia and the cytosol. These results will be important in advancing our understanding of human genetic diseases.