Embryonic stem cell-derived microvesicles reprogram hematopoietic progenitors: evidence for horizontal transfer of mRNA and protein delivery

Clinical investigation on nebulized human umbilical cord MSC-derived extracellular vesicles for pulmonary fibrosis treatment

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are recognized as a promising strategy for cell-free therapy, however, their therapeutic role in pulmonary fibrosis remains unrevealed. Here, we report the safety and efficacy of MSC-EVs from human umbilical cord (hUCMSC-EVs) evaluated in mouse models and pulmonary fibrosis patients. We established a rigorous system to produce high-quality of hUCMSC-EVs, characterized by miRNA, protein, and metabolite profiles. When administered via nebulization, hUCMSC-EVs predominantly accumulated in murine lungs and ameliorated bleomycin-induced pulmonary fibrosis, with increased survival rate (from 20% to 80%), restored lung volume, and attenuated injury severity accompanied by elevated oxyhemoglobin saturation and improved pulmonary function evaluations. We performed a phase l clinical trial involving twenty-four patients in a randomized, single-blind, and placebo-controlled study to treat pulmonary fibrosis (MR-46-22-004531, ChiCTR2300075466). All participants tolerated the nebulized hUCMSC-EVs well, with no serious adverse events. Patients receiving the combined therapy of nebulized hUCMSC-EVs and routine treatment demonstrated significant improvements in both lung function indices (forced vital capacity and maximal voluntary ventilation) and respiratory health status (as measured by the Saint George's Respiratory Questionnaire and Leicester Cough Questionnaire. Overall, patients upon the additional therapy with nebulized hUCMSC-EVs gained significant benefits compared with those accepted only routine treatment. Remarkably, two patients with advanced post-inflammatory pulmonary fibrosis exhibited clinically significant regression on serial CT scans after hUCMSC-EVs therapy. These findings suggest that nebulized hUCMSC-EVs could be used as a promising therapeutic strategy for treating pulmonary fibrosis diseases.

Minimum information for studies of extracellular vesicles (MISEV) as toolbox for rigorous, reproducible and homogeneous studies on extracellular vesicles

Studies based on extracellular vesicles (EVs) have been multiplying exponentially for almost two decades, since they were first identified as vectors of cell-cell communication. However, several of these studies display a lack of rigor in EVs characterization and isolation, without discriminating between the different EV populations, thus generating conflicting and unreproducible results. There is therefore a strong need for standardization and guidelines to conduct studies that are rigorous, transparent, reproducible and comply with certain nomenclatures concerning the type of EVs used. The International Society for Extracellular Vesicles (ISEV) published the Minimum Information for Studies of Extracellular Vesicles (MISEV) in 2014, updating it in 2018 and 2023 to reflect different study contexts and technical advancements. The primary objective of this review is to inform future authors about EVs, including their history, nomenclature, and technical recommendations for the for isolation and functionality analysis for conducing EV-based studies according to current standards. Additionally, it aims to inform reviewers about the key parameters required for characterizing EV preparations.

Liquid Biopsy: The Challenges of a Revolutionary Approach in Oncology

Liquid biopsy has gained attention in oncology as a non-invasive diagnostic tool, offering valuable insights into tumor biology through the analysis of circulating nucleic acid (cfDNA and cfRNA), circulating tumor cells (CTCs), extracellular vesicles (EVs), and tumor-educated platelets (TEPs). In this review, we summarize the clinical use of liquid biopsies in cancer now and look forward to its future, with a particular emphasis on some the methods used to isolate the liquid biopsy analytes. This technique provides real-time information on tumor dynamics, treatment response, and disease progression, with the potential for early diagnosis and personalized treatment. Despite its advantages, liquid biopsy faces several challenges, particularly in detecting analytes in early-stage cancers and evaluating the tumor molecular fraction. Tumor burden, molecular fraction, and the presence of subclones can impact the sensitivity and specificity of the analysis. Recent advancements in artificial intelligence (AI) have enhanced the diagnostic accuracy of liquid biopsy by integrating data, and multimodal approaches that combine multiple biomarkers such as ctDNA, CTCs, EVs, and TEPs show promise in providing a more comprehensive view of tumor characteristics. Liquid biopsy has the potential to revolutionize cancer care by providing rapid, non-invasive, and cost-effective diagnostics, enabling timely interventions and personalized treatment strategies.

Ribonuclease activity undermines immune sensing of naked extracellular RNA

Cell membranes are thought of as barriers to extracellular RNA (exRNA) uptake. While naked exRNAs can be spontaneously internalized by certain cells, functional cytosolic delivery has been rarely observed. Here, we show that extracellular ribonucleases (RNases)-primarily from cell culture supplements-have obscured the study of exRNA functionality. When ribonuclease inhibitor (RI) is added to cell cultures, naked exRNAs can trigger pro-inflammatory responses in dendritic cells and macrophages, largely via endosomal Toll-like receptors (TLRs). Moreover, naked exRNAs can escape endosomes, engaging cytosolic RNA sensors. In addition, naked extracellular mRNAs can be spontaneously internalized and translated by various cell types in an RI-dependent manner. In vivo, RI co-injection amplifies naked-RNA-induced activation of splenic lymphocytes and myeloid leukocytes. Furthermore, naked RNA is inherently pro-inflammatory in RNase-poor compartments like the peritoneal cavity. These findings demonstrate that naked RNA is bioactive without requiring vesicular encapsulation, making a case for nonvesicular-exRNA-mediated intercellular communication.

Progress of mesenchymal stem cell-derived exosomes in targeted delivery of antitumor drugs

Mesenchymal stem cells (MSCs) are currently being used in clinical trials for the treatment of a wide range of diseases and have a wide range of applications in the fields of tissue engineering and regeneration. Exosomes are extracellular vesicles containing a variety of components such as proteins, nucleic acids and lipids, which are widely present in biological fluids and have the functions of participating in intercellular information transfer, immune response and tissue repair, and can also be used as carriers to target and deliver tumors to improve therapeutic effects. Mesenchymal stem cell-derived Exosomes (MSC-Exos), which have the advantages of low immunogenicity and high tumor homing ability, have attracted much attention in targeted drug delivery. Here, we review the current knowledge on the involvement of MSC-Exos in tumor progression and their potential as drug delivery systems in targeted therapies. It also discusses the advantages and prospects of MSC-Exos as a drug carrier and the challenges that still need to be overcome.

Extracellular membrane particles en route to the nucleus - exploring the VOR complex

Intercellular communication is an essential hallmark of multicellular organisms for their development and adult tissue homeostasis. Over the past two decades, attention has been focused on communication mechanisms based on various membrane structures, as illustrated by the burst of scientific literature in the field of extracellular vesicles (EVs). These lipid bilayer-bound nano- or microparticles, as vehicle-like devices, act as regulators in various biological and physiological processes. When EVs are internalized by recipient cells, their membrane and cytoplasmic cargoes can interfere with cellular activities, affecting pathways that regulate cell proliferation, differentiation, and migration. In cancer, EVs can transfer oncogenic factors, stimulate neo-angiogenesis and immunosuppression, reprogram stromal cells, and confer drug resistance traits, thereby remodeling the surrounding microenvironment. Although the mechanisms underlying EV biogenesis and uptake are now better understood, little is known about the spatiotemporal mechanism(s) of their actions after internalization. In this respect, we have shown that a fraction of endocytosed EVs reaches the nuclear compartment via the VOR (VAP-A-ORP3-Rab7) complex-mediated docking of late endosomes to the outer nuclear membrane in the nucleoplasmic reticulum, positioning and facilitating the transfer of EV cargoes into the nucleoplasm via nuclear pores. Here, we highlight the EV heterogeneity, the cellular pathways governing EV release and uptake by donor and recipient cells, respectively, and focus on a novel intracellular pathway leading to the nuclear transfer of EV cargoes. We will discuss how to intercept it, which could open up new avenues for clinical applications in which EVs and other small extracellular particles (e.g., retroviruses) are implicated.

Keratinocyte-derived extracellular vesicles induce macrophage polarization toward an M1-like phenotype

Multiple reports have shown an effect of keratinocyte-derived extracellular vesicles (EVs) on keratinocytes and other cell types. However, the contribution of keratinocyte-derived EVs under physiological and pathological conditions is not fully elucidated. Therefore, whether there is an effect of EVs on macrophages in cervical cancer (CC) is also unknown. Here, we evaluated the effect of tumor and non-tumor keratinocyte-derived EVs on the polarization of peripheral blood mononuclear cells (PBMCs)-derived macrophages and THP-1 cell line. Flow cytometric evaluation of macrophages cultured in the presence of keratinocyte-derived EVs mainly indicated an increase in classical activation markers CD80 and CD86 (M1 phenotype) and little or no modification of alternative activation markers (M2 phenotype). ELISA evaluation of macrophage supernatants revealed an increase in the secretion of proinflammatory cytokines such as IL-1β and IL-6. On the other hand, TGF-β was not significantly modified and only EVs derived from non-cancerous keratinocytes induced a significant increase in IL-10. The expression levels of transcripts associated with the M1 phenotype were also evaluated by qRT-PCR with similar results to ELISA for TGF-β and IL-10; but also an increase in the expression of HLA-DRα and TNF-α was observed, and no statistically significant changes in ARG1. The ROS production was also evaluated and this increase mainly in macrophages treated with CC keratinocytes-derived EVs. So, our results suggest that the uptake of EVs derived from released by non-tumor and cervical cancer keratinocytes promotes in macrophages their polarization to an M1-like phenotype.

Rigorous Process for Isolation of Gut-Derived Extracellular Vesicles (EVs) and the Effect on Latent HIV

The human gastrointestinal (GI) track host trillions of microorganisms that secrete molecules, including extracellular vesicles (EVs) and extracellular condensates (ECs) that may affect physiological and patho-physiological activities in the host. However, efficient protocols for the isolation of pure and functional GI-derived EVs|ECs is lacking. Here, we describe the use of high-resolution particle purification liquid chromatography (PPLC) gradient-bead-column integrated with polyvinylpolypyrrolidone (PVPP)-mediated extraction of impurities to isolate EVs from colonic content (ColEVs). PVPP facilitates the isolation of pure, non-toxic, and functionally active ColEVs that were internalized by cells and functionally activate HIV LTR promoter. ColEVs isolated without PVPP have a reductive effect on MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) without living cells, suggesting that ColEVs contain reductases capable of catalyzing the reduction of MTT to formazan. The assessment of the origin of ColEVs reveals that they are composed of both bacteria and host particles. This protocol requires ~12 h (5 h preprocessing, 7 h isolation) to complete and should be used to purify EVs from sources contaminated with microbial agents to improve rigor. This protocol provides a robust tool for researchers and clinicians investigating GI-derived EVs and the translational use of GI-derived EVs for diagnostic and therapeutic use. Additionally, GI-derived EVs may serve as a window into the pathogenesis of diseases.

Unlocking a Decade of Research on Embryo-Derived Extracellular Vesicles: Discoveries Made and Paths Ahead

Over the past decade, research on embryo-derived extracellular vesicles (EVs) has unveiled their critical roles in embryonic development and intercellular communication. EVs secreted by embryos are nanoscale lipid bilayer vesicles that carry bioactive cargo, including proteins, lipids, RNAs, and DNAs, reflecting the physiological state of the source cells. These vesicles facilitate paracrine and autocrine signaling, influencing key processes such as cell differentiation, embryo viability, and endometrial receptivity. Studies reveal that EVs can traverse the zona pellucida, transferring molecular signals that enhance blastocyst formation and support embryo-maternal crosstalk. EVs have emerged as non-invasive biomarkers for embryo quality, with their cargo providing insights into genetic integrity and developmental competence. Advances in isolation and characterization techniques have identified specific microRNA (miRNAs) and transcription factors within EVs, offering potential for use in preimplantation genetic screening (PGS) and sex determination. Moreover, EV-mediated interactions with the maternal environment are critical for successful implantation, as they modulate gene expression and immune responses in endometrial and oviductal cells. Despite these advancements, challenges persist, including the standardization of EV isolation methods and the low yield of EVs DNA from spent culture media. Future research should aim to refine analytical techniques, explore EV-miRNA profiling, and investigate the mechanisms underlying EV-mediated signaling. By addressing these gaps, EVs could revolutionize embryo selection and reproductive technologies, offering new strategies to improve outcomes in assisted reproduction and animal breeding.

Extracellular Vesicles Alter Trophoblast Function in Pregnancies Complicated by COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and resulting coronavirus disease (COVID-19) cause placental dysfunction, which increases the risk of adverse pregnancy outcomes. While abnormal placental pathology resulting from COVID-19 is common, direct infection of the placenta is rare. This suggests that pathophysiology associated with maternal COVID-19, rather than direct placental infection, is responsible for placental dysfunction. We hypothesized that maternal circulating extracellular vesicles (EVs), altered by COVID-19 during pregnancy, contribute to placental dysfunction. To examine this hypothesis, we characterized circulating EVs from pregnancies complicated by COVID-19 and tested their effects on trophoblast cell physiology in vitro. Trophoblast exposure to EVs isolated from patients with an active infection (AI), but not controls, altered key trophoblast functions including hormone production and invasion. Thus, circulating EVs from participants with an AI, both symptomatic and asymptomatic cases, can disrupt vital trophoblast functions. EV cargo differed between participants with COVID-19, depending on the gestational timing of infection, and Controls, which may contribute to the disruption of the placental transcriptome and morphology. Our findings show that COVID-19 can have effects throughout pregnancy on circulating EVs, and circulating EVs are likely to participate in placental dysfunction induced by COVID-19.

Innovative Applications of Nanopore Technology in Tumor Screening: An Exosome-Centric Approach

Cancer remains one of the leading causes of death worldwide. Its complex pathogenesis and metastasis pose significant challenges for early diagnosis, underscoring the urgent need for innovative and non-invasive tumor screening methods. Exosomes, small extracellular vesicles that reflect the physiological and pathological states of their parent cells, are uniquely suited for cancer liquid biopsy due to their molecular cargo, including RNA, DNA, and proteins. However, traditional methods for exosome isolation and detection are often limited by inadequate sensitivity, specificity, and efficiency. Nanopore technology, characterized by high sensitivity and single-molecule resolution, offers powerful tools for exosome analysis. This review highlights its diverse applications in tumor screening, such as magnetic nanopores for high-throughput sorting, electrochemical sensing for real-time detection, nanomaterial-based assemblies for efficient capture, and plasmon resonance for ultrasensitive analysis. These advancements have enabled precise exosome detection and demonstrated promising potential in the early diagnosis of breast, pancreatic, and prostate cancers, while also supporting personalized treatment strategies. Additionally, this review summarizes commercialized products for exosome-based cancer diagnostics and examines the technical and translational challenges in clinical applications. Finally, it discusses the future prospects of nanopore technology in advancing liquid biopsy toward clinical implementation. The continued progress of nanopore technology not only accelerates exosome-based precision medicine but also represents a significant step forward in next-generation liquid biopsy and tumor screening.

The Proteomic Analysis of Platelet Extracellular Vesicles in Diabetic Patients by nanoLC-MALDI-MS/MS and nanoLC-TIMS-MS/MS

Platelet extracellular vesicles (PEVs) are emerging as key biomarkers in diabetes mellitus (DM), reflecting altered platelet function and coagulation pathways. This study compares two proteomic techniques-nanoLC-MALDI-MS/MS and nanoLC-TIMS-MS/MS-for analyzing PEVs in diabetic patients, to assess their potential for biomarker discovery. PEVs were isolated from platelet-rich plasma and characterized using tunable resistive pulse sensing (TRPS), Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Proteomic analyses identified significant differences in protein expression between diabetic and non-diabetic individuals, with nanoLC-TIMS-MS/MS demonstrating superior sensitivity by detecting 97% more unique proteins than nanoLC-MALDI-MS/MS. Key differentially expressed proteins included apolipoproteins and oxidative stress markers, which may contribute to platelet dysfunction and cardiovascular complications in DM. Sex-specific variations in protein expression were also observed, highlighting potential differences in disease progression between male and female patients. The integration of advanced proteomic methodologies provides novel insights into the role of PEVs in diabetes pathophysiology, underscoring their diagnostic and therapeutic potential. These findings pave the way for improved biomarker-based strategies for early detection and monitoring of diabetic complications.

Extracellular microvesicles/exosomes-magic bullets in horizontal transfer between cells of mitochondria and molecules regulating mitochondria activity

Extracellular microvesicles (ExMVs) were one of the first communication platforms between cells that emerged early in evolution. Evidence indicates that all types of cells secrete these small circular structures surrounded by a lipid membrane that plays an important role in cellular physiology and some pathological processes. ExMVs interact with target cells and may stimulate them by ligands expressed on their surface and/or transfer to the target cells their cargo comprising various RNA species, proteins, bioactive lipids, and signaling nucleotides. These small vesicles can also hijack some organelles from the cells and, in particular, transfer mitochondria, which are currently the focus of scientific interest for their potential application in clinical settings. Different mechanisms exist for transferring mitochondria between cells, including their encapsulation in ExMVs or their uptake in a "naked" form. It has also been demonstrated that mitochondria transfer may involve direct cell-cell connections by signaling nanotubules. In addition, evidence accumulated that ExMVs could be enriched for regulatory molecules, including some miRNA species and proteins that regulate the function of mitochondria in the target cells. Recently, a new beneficial effect of mitochondrial transfer has been reported based on inducing the mitophagy process, removing damaged mitochondria in the recipient cells to improve their energetic state. Based on this novel role of ExMVs in powering the energetic state of target cells, we present a current point of view on this topic and review some selected most recent discoveries and recently published most relevant papers.

Very small embryonic-like stem cells (VSELs) on the way for potential applications in regenerative medicine

Evidence has accumulated that adult tissues contain a population of early development stem cells capable of differentiating across germ layers into various types of cells. Our group purified these rare cells, naming them very small embryonic-like stem cells (VSELs). With their broad differentiation potential, VSELs have emerged as a new candidate population for clinical applications. This advancement is now possible due to our recent development of a model for ex vivo expansion of these rare cells. Importantly, no evidence suggests that VSELs, isolated from adult tissues, can form teratomas. In this review paper, we update current research on these cells reported in our laboratory as well as in those of several independent investigators.

Mesenchymal Stromal Cell-Derived Extracellular Vesicles in the Management of Atopic Dermatitis: A Scoping Review of Therapeutic Opportunities and Challenges

Atopic dermatitis (AD) is a global concern marked by inflammation, skin barrier dysfunction, and immune dysregulation. Current treatments primarily address symptoms without offering a cure, underscoring the need for innovative therapeutic approaches. Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) have attracted attention for their potential in immunomodulation and tissue repair, similar to their parent cells. This review provides a comprehensive analysis of the current landscape of MSC-EV research for AD management. We identified 12 studies that met our predefined inclusion criteria. We thoroughly reviewed both human and animal studies, analyzing aspects such as the source, isolation, and characterization of MSC-EVs, as well as the animal and disease models, dosage strategies, efficacy, mechanisms, and adverse effects. While this review highlights the promising potential of MSC-EV therapy for AD, it also emphasizes significant challenges, including heterogeneity and insufficient reporting. Given that this research area is still in its early stages, addressing these uncertainties will require collaborative efforts among researchers, regulatory bodies, and international societies to advance the field and improve patient outcomes.

Extracellular vesicle-mediated chemoresistance in breast cancer: focus on miRNA cargo

The role of extracellular vesicles (EVs) in mediating chemoresistance has gained significant attention due to their ability to transfer bioactive molecules between drug-resistant and drug-sensitive cells. In particular, they have been demonstrated to play an active part in breast cancer chemoresistance by the horizontal transfer of genetic and protein material. This review highlights the role of EVs, particularly their miRNA cargo, in driving drug resistance in breast cancer. EVs derived from chemoresistant cells carry miRNAs and lncRNAs, which are known to modulate gene networks involved in cell proliferation and survival. These cargo molecules suppress apoptosis by targeting pro-apoptotic genes like PTEN and BIM, promote epithelial-mesenchymal transition (EMT) through the regulation of pathways such as TGF-β and Wnt/b-catenin, and contribute to tumor growth and resistance by enhancing angiogenesis and modulating the tumor microenvironment. Beyond RNA-mediated effects, EVs also transfer functional proteins, including P-glycoprotein and Hsp70, which impact cellular metabolism and survival pathways. Our findings underscore the significance of EVs in breast cancer chemoresistance, suggesting their potential involvement as possible prognostic factors to predict therapy response and as therapeutic targets in combination with usual therapy.

Amniotic epithelial Cell microvesicles uptake inhibits PBMCs and Jurkat cells activation by inducing mitochondria-dependent apoptosis

Amniotic epithelial cells (AECs) exhibit significant immunomodulatory and pro-regenerative properties, largely due to their intrinsic paracrine functions that are currently harnessed through the collection of their secretomes. While there is increasing evidence of the role of bioactive components freely secreted or carried by exosomes, the bioactive cargo of AEC microvesicles (MVs) and their crosstalk with the immune cells remains to be fully explored. We showed that under intrinsic conditions or in response to LPS, AEC-derived MV carries components such as lipid-mediated signaling molecules, ER, and mitochondria. They foster the intra/interspecific mitochondrial transfer into immune cells (PBMCs and Jurkat cells) in vitro and in vivo on the zebrafish larvae model of injury. The internalization of MV cargoes through macropinocytosis induces hyperpolarization of PBMC mitochondrial membranes and triggers MV-mediated apoptosis. This powerful immune suppressive mechanism triggered by AEC-MV cargo delivery paves the way for controlled and targeted cell-free therapeutic approaches.

Recent Advances in Microfluidics for Nucleic Acid Analysis of Small Extracellular Vesicles in Cancer

Small extracellular vesicles (sEVs) are membranous vesicles released from cellular structures through plasma membrane budding. These vesicles contain cellular components such as proteins, lipids, mRNAs, microRNAs, long-noncoding RNA, circular RNA, and double-stranded DNA, originating from the cells they are shed from. Ranging in size from ≈25 to 300 nm and play critical roles in facilitating cell-to-cell communication by transporting signaling molecules. The discovery of sEVs in bodily fluids and their involvement in intercellular communication has revolutionized the fields of diagnosis, prognosis, and treatment, particularly in diseases like cancer. Conventional methods for isolating and analyzing sEVs, particularly their nucleic acid content face challenges including high costs, low purity, time-consuming processes, limited standardization, and inconsistent yield. The development of microfluidic devices, enables improved precision in sorting, isolating, and molecular-level separation using small sample volumes, and offers significant potential for the enhanced detection and monitoring of sEVs associated with cancer. These advanced techniques hold great promise for creating next-generation diagnostic and prognostic tools given their possibility of being cost-effective, simple to operate, etc. This comprehensive review explores the current state of research on microfluidic devices for the detection of sEV-derived nucleic acids as biomarkers and their translation into practical point-of-care and clinical applications.

Metabolic Messengers: small extracellular vesicles

Small extracellular vesicles (sEVs) are signalling molecules and biomarkers of cell status that govern a complex intraorgan and interorgan communication system through their cargo. Initially recognized as a waste disposal mechanism, they have emerged as important metabolic regulators. They transfer biological signals to recipient cells through their cargo content, and microRNAs (miRNAs) often mediate their metabolic effects. This review provides a concise overview of sEVs, specifically in the context of obesity-associated chronic inflammation and related metabolic disorders, describing their role as metabolic messengers, identifying their key sites of action and elucidating their mechanisms. We highlight studies that have shaped our understanding of sEV metabolism, address critical questions for future exploration, discuss the use of miRNAs as disease biomarkers and provide insights into the therapeutic potential of sEVs or specific miRNAs for treating metabolic diseases and related disorders in the future.

Clinical studies of blood-borne Extracellular vesicles in psychiatry: A systematic review

Biomarkers for the diagnosis and clinical management of psychiatric disorders are currently lacking. Extracellular vesicles (EVs), lipid membrane-encapsulated vesicles released by cells, hold promise as a source of biomarkers due to their ability to carry molecules that reflect the status of their donor cells and their ubiquitous presence in biofluids. This review examines the literature on EVs in biofluids from psychiatric disorder patients, and discuss how the published studies contribute to our understanding of the pathophysiology of these conditions and to the discovery of potential biomarkers. We analyzed 46 studies on blood-borne EVs; no investigations on cerebrospinal fluid-derived EVs were found. A significant number of studies lacked optimal description of the methodology and/or characterization of the isolated EVs. Moreover, many studies aimed to capture brain-derived EVs, but often capture-proteins with low brain specificity were used. Considering biomarkers, miRNAs were the most investigated molecular type, but based on the studies analyzed it was not possible to identify robust biomarker candidates for the investigated disorders. Additionally, we describe the contribution of EV studies in illuminating the pathophysiology of psychiatric disorders, including research on insulin resistance, inflammation, mitochondrial dysfunction, and the microbiota. We conclude that there is a shortage of studies with detailed methodology description and EV sample characterization in psychiatric research. To exploit the potential of EVs to investigate psychiatric disorders and identify biomarkers more studies and validated protocols using capture proteins with high specificity to brain cells are needed. The review protocol was pre-registered in the PROSPERO database under the registration number CRD42021277534.

Prominosomes - a particular class of extracellular vesicles containing prominin-1/CD133?

Extracellular membrane vesicles (EVs) offer promising values in various medical fields, e.g., as biomarkers in liquid biopsies or as native (or bioengineered) biological nanocarriers in tissue engineering, regenerative medicine and cancer therapy. Based on their cellular origin EVs can vary considerably in composition and diameter. Cell biological studies on mammalian prominin-1, a cholesterol-binding membrane glycoprotein, have helped to reveal new donor membranes as sources of EVs. For instance, small EVs can originate from microvilli and primary cilia, while large EVs might be produced by transient structures such as retracting cellular extremities of cancer cells during the mitotic rounding process, and the midbody at the end of cytokinesis. Here, we will highlight the various subcellular origins of prominin-1+ EVs, also called prominosomes, and the potential mechanism(s) regulating their formation. We will further discuss the molecular and cellular characteristics of prominin-1, notably those that have a direct effect on the release of prominin-1+ EVs, a process that might be directly implicated in donor cell reprogramming of stem and cancer stem cells. Prominin-1+ EVs also mediate intercellular communication during embryonic development and adult homeostasis in healthy individuals, while disseminating biological information during diseases.

Technical considerations and review of urinary microRNAs as biomarkers for chronic kidney disease in dogs and cats

MicroRNAs (miRNAs or miRs) are small, non-coding RNAs that play a crucial role in gene regulation, making them potential biomarkers for various diseases. In the field of veterinary medicine, there is a growing interest in exploring the diagnostic and therapeutic potential of miRNAs in kidney diseases affecting dogs and cats. This review focuses on the use of urinary miRNAs as biomarkers for chronic kidney disease (CKD) in these companion animals. We introduce miRNAs, their biogenesis, and their presence in biofluids, particularly within exosomes, and discuss studies investigating miRNAs in kidney tissue and urine. We acknowledge the challenges associated with miRNA studies, including preanalytical factors such as biological variation, sample collection/processing, storage conditions, and experimental design. We highlight the importance of technical considerations, such as sample pooling, sequencing depth, multiplexing, and the various steps of the miRNA experimental workflow. Furthermore, we discuss RNA isolation methods, small RNA sequencing data analysis, and the use of quantitative reverse transcription PCR (qRT-PCR) and droplet digital PCR for verification. We emphasize the importance of internal controls, spike-ins, and normalization methods to minimize technical variation and ensure reliable results in qRT-PCR analysis. This review concludes that while urinary miRNAs hold promise as non-invasive biomarkers for CKD in dogs and cats, addressing the challenges and standardization of protocols is vital for the successful translation of this research into clinical practice.

Extracellular vesicles: essential agents in critical bone defect repair and therapeutic enhancement

Bone serves as a fundamental structural component in the body, playing pivotal roles in support, protection, mineral supply, and hormonal regulation. However, critical-sized bone injuries have become increasingly prevalent, necessitating extensive medical interventions due to limitations in the body's capacity for self-repair. Traditional approaches, such as autografts, allografts, and xenografts, have yielded unsatisfactory results. Stem cell therapy emerges as a promising avenue, but challenges like immune rejection and low cell survival rates hinder its widespread clinical implementation. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have garnered attention for their regenerative capabilities, which surpass those of MSCs themselves. EVs offer advantages such as reduced immunogenicity, enhanced stability, and simplified storage, positioning them as a promising tool in stem cell-based therapies. This review explores the potential of EV-based therapy in bone tissue regeneration, delving into their biological characteristics, communication mechanisms, and preclinical applications across various physiological and pathological conditions. The mechanisms underlying EV-mediated bone regeneration, including angiogenesis, osteoblast proliferation, mineralization, and immunomodulation, are elucidated. Preclinical studies demonstrate the efficacy of EVs in promoting bone repair and neovascularization, even in pathological conditions like osteoporosis. EVs hold promise as a potential alternative for regenerating bone tissue, particularly in the context of critical-sized bone defects, offering new avenues for effective bone defect repair and management.

Rigorous process for isolation of gut-derived extracellular vesicles and the effect on latent HIV

Aim

Extracellular particles (EPs) are produced/secreted by cells from all domains of life and are present in all body fluids, brain, and gut. EPs consist of extracellular vesicles (EVs) made up of exosomes, microvesicles, and other membranous vesicles; and extracellular condensates (ECs) that are non-membranous carriers of lipid-protein-nucleic acid aggregates. The purity of EVs|ECs, which ultimately depends on the isolation method used to obtain them is critical, particularly EVs|ECs from the gastrointestinal (GI) tract that is colonized by a huge number of enteric bacteria. Therefore, identifying GI derived EVs|ECs of bacterial and host origin may serve as a window into the pathogenesis of diseases and as a potential therapeutic target.

Methods

Here, we describe the use of high-resolution particle purification liquid chromatography (PPLC) gradient-bead-column integrated with polyvinylpolypyrrolidone (PVPP)-mediated extraction of impurities to isolate GI-derived EPs.

Results and Conclusion

PVPP facilitates isolation of pure and functionally active, non-toxic EVs ColEVs from colonic contents. ColEVs are internalized by cells and they activate HIV LTR promoter. In the absence of PVPP, ColEVs have a direct reductive potential of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) absorbance in a cell-free system. Assessment of the origin of ColEVs reveals that they are composed of both bacteria and host particles. This protocol requires ∼12 hours (5 hours preprocessing, 7 hours isolation) to complete and should be used to purify EVs from sources contaminated with microbial agents to improve rigor. Additionally, this protocol provides a robust tool for researchers and clinicians investigating GI-derived EVs and the translational use of GI-derived EVs for diagnostic and therapeutic use.

Highlight

ColEVs but not ColECs are present in colonic content (GI tract) and can be isolated with gradient or single bead PPLC column.ColEVs isolated without PVPP are toxic to cells and they have a direct reductive potential of MTT. Addition of PVPP treatment in the isolation protocol results in clean and non-toxic ColEVs that transactivate the HIV LTR promoter.

Engineering therapeutical extracellular vesicles for clinical translation

Cell-based therapies are revolutionizing medicine by replacing or modifying dysfunctional cells with healthy cells or engineered derivatives, offering disease reversal and cure. One promising approach is using cell-derived extracellular vesicles (EVs), which offer therapeutic benefits similar to cell transplants without the biosafety risks. Although EV applications face challenges like limited production, inadequate therapeutic loading, and poor targeting efficiency, recent advances in bioengineering have enhanced their effectiveness. Herein, we summarize technological breakthroughs in EV bioengineering over the past 5 years, highlighting their improved therapeutic functionalities and potential clinical prospects. We also discuss biomanufacturing processes, regulation, and safety considerations for bioengineered EV therapies, emphasizing the significance of establishing robust frameworks to ensure translation capability, safety, and therapeutic effectiveness for successful clinical adoption.

Early vascular aging in chronic kidney disease: focus on microvascular maintenance, senescence signature and potential therapeutics

Chronic kidney disease (CKD) is a strong risk factor for cardiovascular mortality and morbidity. We hypothesized that a senescent phenotype instigated by uremic toxins could account for early vascular aging (EVA) and vascular dysfunctions of microvasculature in end stage kidney disease (ESKD) patients which ultimately lead to increased cardiovascular complication. To test this hypothesis, we utilized both in vivo, and ex vivo approaches to study endothelial and smooth muscle function and structure, and characterized markers related to EVA in 82 ESKD patients (eGFR <15 ml/min) and 70 non-CKD controls. In vivo measurement revealed no major difference in endothelial function between ESKD and control group, aside from higher stiffness detected in the microcirculation of ESKD participants. In contrast, ex vivo measurements revealed a notable change in the contribution of endothelium-derived factors and increased stiffness in ESKD patients vs. controls. In support, we demonstrated that ex vivo exposure of arteries to uremic toxins such as Trimethylamine N-oxide, Phenylacetylglutamine, or extracellular vesicles from CKD patients impaired endothelial function via diminishing the contribution of endothelium-derived relaxing factors such as nitric oxide and endothelium derived hyperpolarizing factor. Uremic arteries displayed elevated expression of senescence markers (p21CIP1, p16INK4a, and SA-β-gal), calcification marker (RUNX2), and reduced expression of Ki67, sirtuin1, Nrf2, and MHY11 markers, indicating the accumulation of senescent cells and EVA phenotype. Correspondingly, treating uremic vessel rings ex vivo with senolytic agents (Dasatinib + Quercetin) effectively reduced the senescence-associated secretory phenotype and changed the origin of extracellular vesicles. Notably, sex differences exist for certain abnormalities suggesting the importance of biological sex in the pathogenesis of vascular complications. In conclusion, the uremic microvasculature is characterized by a "senescence signature", which may contribute to EVA and cardiovascular complications in ESKD patients and could be alleviated by treatment with senolytic agents.

Exploring Extracellular Vesicle Transcriptomic Diversity Through Long-Read Nanopore Sequencing

Nanopore long-read RNA sequencing is reshaping extracellular vesicle (EV) research by providing the capacity to analyze full-length RNA molecules. EVs are crucial for intercellular communication, carrying a diverse range of RNA cargo that can regulate recipient cell behavior. However, traditional short-read sequencing methods involve transcript fragmentation, limiting our understanding of the EV transcriptomic landscape. Furthermore, it has been generally assumed that EV RNAs are likely to be fragmentation products of cellular RNAs, and the extent to which full length RNAs are present within EVs remains to be clarified. Recent advancements in sequencing technology, particularly long-read sequencing by Oxford Nanopore Technologies (ONT), offer a solution to this limitation. Hence, long-read sequencing allows for the analysis of full-length EV RNA molecules, providing deeper insights into their integrity and isoform diversity. Here, we present a comprehensive protocol for EV RNA purification, cDNA library preparation, and sequencing using ONT's MinION platform.

The Role of Cardiac Troponin and Other Emerging Biomarkers Among Athletes and Beyond: Underlying Mechanisms, Differential Diagnosis, and Guide for Interpretation

Cardiovascular (CV) disease remains the leading cause of morbidity and mortality worldwide, highlighting the necessity of understanding its underlying molecular and pathophysiological pathways. Conversely, physical activity (PA) and exercise are key strategies in reducing CV event risks. Detecting latent CV conditions in apparently healthy individuals, such as athletes, presents a unique challenge. The early identification and treatment of CV disorders are vital for long-term health and patient survival. Cardiac troponin is currently the most commonly used biomarker for assessing CV changes in both athletes and the general population. However, there remains considerable debate surrounding the mechanisms underlying exercise-induced troponin elevations and its release in non-ischemic contexts. Thus, there is a pressing need to identify and implement more sensitive and specific biomarkers for CV disorders in clinical practice. Indeed, research continues to explore reliable biomarkers for evaluating the health of athletes and the effectiveness of physical exercise. It is essential to analyze current evidence on troponin release in non-ischemic conditions, post-strenuous exercise, and the complex biological pathways that influence its detection. Furthermore, this study summarizes current research on cytokines and exosomes, including their physiological roles and their relevance in various CV conditions, especially in athletes. In addition, this paper gives special attention to underlying mechanisms, potential biomarkers, and future perspectives.

Research progress on astrocyte-derived extracellular vesicles in the pathogenesis and treatment of neurodegenerative diseases

Neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD), pose significant global health risks and represent a substantial public health concern in the contemporary era. A primary factor in the pathophysiology of these disorders is aberrant accumulation and aggregation of pathogenic proteins within the brain and spinal cord. Recent investigations have identified extracellular vesicles (EVs) in the central nervous system (CNS) as potential carriers for intercellular transport of misfolded proteins associated with neurodegenerative diseases. EVs are involved in pathological processes that contribute to various brain disorders including neurodegenerative disorders. Proteins linked to neurodegenerative disorders are secreted and distributed from cell to cell via EVs, serving as a mechanism for direct intercellular communication through the transfer of biomolecules. Astrocytes, as active participants in CNS intercellular communication, release astrocyte-derived extracellular vesicles (ADEVs) that are capable of interacting with diverse target cells. This review primarily focuses on the involvement of ADEVs in the development of neurological disorders and explores their potential dual roles - both advantageous and disadvantageous in the context of neurological disorders. Furthermore, this review examines the current studies investigating ADEVs as potential biomarkers for the diagnosis and treatment of neurodegenerative diseases. The prospects and challenges associated with the application of ADEVs in clinical settings were also comprehensively reviewed.

Approaches and Challenges in Characterizing the Molecular Content of Extracellular Vesicles for Biomarker Discovery

Extracellular vesicles (EVs) are lipid bilayer nanoparticles released from all known cells and are involved in cell-to-cell communication via their molecular content. EVs have been found in all tissues and body fluids, carrying a variety of biomolecules, including DNA, RNA, proteins, metabolites, and lipids, offering insights into cellular and pathophysiological conditions. Despite the emergence of EVs and their molecular contents as important biological indicators, it remains difficult to explore EV-mediated biological processes due to their small size and heterogeneity and the technical challenges in characterizing their molecular content. EV-associated small RNAs, especially microRNAs, have been extensively studied. However, other less characterized RNAs, including protein-coding mRNAs, long noncoding RNAs, circular RNAs, and tRNAs, have also been found in EVs. Furthermore, the EV-associated proteins can be used to distinguish different types of EVs. The spectrum of EV-associated RNAs, as well as proteins, may be associated with different pathophysiological conditions. Therefore, the ability to comprehensively characterize EVs' molecular content is critical for understanding their biological function and potential applications in disease diagnosis. Here, we set out to provide an overview of EV-associated RNAs and proteins as well as approaches currently being used to characterize them.

Role of Redox Homeostasis in the Communication Between Brain and Liver Through Extracellular Vesicles

Extracellular vesicles (EVs) are small, membrane-bound particles secreted by cells into the extracellular environment, playing an increasingly recognized role in inter-organ communication and the regulation of various physiological processes. Regarding the redox homeostasis context, EVs play a pivotal role in propagating and mitigating oxidative stress signals across different organs. Cells under oxidative stress release EVs containing signaling molecules that can influence the redox status of distant cells and tissues. EVs are starting to be recognized as contributors to brain-liver communication. Therefore, in this review, we show how redox imbalance can affect the release of EVs in the brain and liver. We propose EVs as mediators of redox homeostasis in the brain-liver axis.

The Role of Extracellular Vesicles and Microparticles in Central Nervous System Disorders: Mechanisms, Biomarkers, and Therapeutic Potential

Microscopic, membranous vesicles known as extracellular vesicles (EVs) have been proposed to play a role in the mechanisms underlying central nervous system (CNS) diseases. EVs are secreted by a variety of cells, including myeloid, endothelial, microglial, oligodendroglial, and mesenchymal stem cells (MSCs). Body fluids such as plasma, urine, and cerebrospinal fluid (CSF) contain microparticles (MPs). The detection of MPs in CSF may indicate genetic or environmental susceptibility to conditions such as schizophrenia, schizoaffective disorder, and bipolar disorder. MPs of different origins can exhibit changes in specific biomarkers at various stages of the disease, aiding in the diagnosis and monitoring of neurological conditions. However, understanding the role and clinical applications of MPs is complicated by challenges such as their isolation and dual roles within the CNS. In this review, we discuss the history, characteristics, and roles of MPs in CNS diseases. We also provide practical insights for future research and highlight the challenges that obscure the therapeutic potential of MPs.

Extracellular vesicles epitopes as potential biomarker candidates in patients with traumatic spinal cord injury

Background

Extracellular vesicles (EVs), a heterogeneous group of cell-derived, membrane-enclosed vesicles bearing cell-specific epitopes, have been demonstrated to play a crucial role in neuronal-glial communication and the orchestration of neuroinflammatory processes. However, the existing evidence regarding their function as biomarkers and their role in the pathobiology of traumatic spinal cord injuries (tSCI), particularly in humans, is scarce.

Objective

The primary goal of this study was to investigate whether a distinct pattern of EV surface epitopes detected in the plasma of individuals suffering from spinal cord injury is indicative of tSCI.

Methods

The study includes patients with isolated tSCI (n=8), polytrauma patients without tSCI (PT; ISS ≥16, n=8), and healthy volunteers (HV; n=8). Plasma samples from tSCI and PT patients were collected right after admission to the emergency room (ER), 24 hours (24h), and 48h after trauma. EVs were isolated via size exclusion chromatography, and EVs' surface epitopes were quantified with MACSPlex EV Kit Neuro (prototype product, Miltenyi Biotec) and compared among the groups. Additionally, results were correlated with clinical parameters.

Results

In total, 19 epitopes differed significantly between the tSCI and the HV groups. Out of these 19, four (CD47, CD56, CD68, and ADAM17) were found to differ significantly among tSCI and PT groups. The expression of the CD47 epitope was found to correlate positively with the American Spinal Injury Association (ASIA) impairment scale.

Conclusion

We identified four potential EV-based tSCI biomarkers (CD47+, CD56+, CD68+, and ADAM17+ EVs) that differ in tSCI, with CD47+ EVs showing a strong correlation with the neurological function in tSCI. Thus, future studies might further specify the relevance of potential tSCI-specific biomarkers and investigate underlying mechanisms of tSCI.

The prospective roles of exosomes in pituitary tumors

Pituitary neuroendocrine tumors are common, typically benign intracranial neoplasms arising from well-differentiated anterior pituitary cells with prevalence of clinically relevant pituitary tumor of 89 in 100 000 people. Despite the growing number of published studies, there is still a need for diagnostic and predictive biomarkers of pituitary adenomas. Prompt determination of tendency of the tumor for invasive growth and aggressive behavior would allow for earlier and more effective treatment. Extracellular vesicles (EVs), including exosomes, are particles released by cells containing cell-specific cargo including a variety of bioactive molecules, such as DNA, messenger RNA, microRNA, long non-coding RNA, circular RNA, proteins, and lipids surrounded by lipid membranes, which act as mediators of cell to cell communication. The ability of exosomes to reflect the functional state of the tumor, transport informative molecules, and accessibility in body fluids make them promising candidates in the search for biomarkers and new therapeutic methods. This study aims to investigate the involvement of exosomes in the pathology of pituitary adenoma and their potential clinical applications.

Recent Advances of Small Extracellular Vesicles for the Regulation and Function of Cancer-Associated Fibroblasts

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population in the tumor microenvironment (TME) that critically affect cancer progression. Small extracellular vesicles (sEVs) act as information messengers by transmitting a wide spectrum of biological molecules, including proteins, nucleic acids, and metabolites, from donor cells to recipient cells. Previous studies have demonstrated that CAFs play important roles in tumor progression by regulating tumor cell proliferation, metastasis, therapeutic resistance, and metabolism via sEVs. In turn, tumor-derived sEVs can also regulate the activation and phenotype switch of CAFs. The dynamic crosstalk between CAFs and cancer cells via sEVs could ultimately determine cancer progression. In this review, we summarized the recent advance of the biological roles and underlying mechanisms of sEVs in mediating CAF-tumor cell interaction and its impact on cancer progression. We also reviewed the clinical applications of tumor- and CAF-derived sEVs, which could identify novel potential targets and biomarkers for cancer diagnosis, therapy, and prognosis.

Food-derived extracellular vesicles: natural nanocarriers for active phytoconstituents in new functional food

Extracellular vesicles (EVs) are naturally occurring non-replicating particles released from cells, known for their health-promoting effects and potential as carriers for drug delivery. Extensive research has been conducted on delivery systems based on culture-cell-derived EVs. Nevertheless, they have several limitations including low production yield, high expenses, unsuitability for oral administration, and safety concerns in applications. Conversely, food-derived EVs (FDEVs) offer unique advantages that cannot be easily substituted. This review provides a comprehensive analysis of the biogenesis pathways, composition, and health benefits of FDEVs, as well as the techniques required for constructing oral delivery systems. Furthermore, it explores the advantages and challenges associated with FDEVs as oral nanocarriers, and discusses the current research advancements in delivering active phytoconstituents. FDEVs, functioning as a nanocarrier platform for the oral delivery of active molecules, present numerous benefits such as convenient administration, high biocompatibility, low toxicity, and inherent targeting. Nevertheless, numerous unresolved issues persist in the isolation, characterization, drug loading, and application of FDEVs. Technical innovation and standardization of quality control are the key points to promote the development of FDEVs. The review aimed to provide frontier ideas and basic quality control guidelines for developing new functional food based on FDEVs oral drug delivery system.

A negative regulatory role of β-cell-derived exosomes in the glucose-stimulated insulin secretion of recipient β-cells

Exosomes are extracellular vesicles that play a role in intercellular communication through the transportation of their cargo including mRNAs, microRNAs, proteins, and nucleic acids. Exosomes can also regulate glucose homeostasis and insulin secretion under diabetic conditions. However, the role of exosomes in insulin secretion in islet β-cells under physiological conditions remains to be clarified. The aim of this study was to investigate whether exosomes derived from pancreatic islet β-cells could affect insulin secretion in naïve β-cells. We first confirmed that exosomes derived from the RIN-m5f β-cell line interfered with the glucose-stimulated insulin secretion (GSIS) of recipient β-cells without affecting cell viability. The exosomes significantly reduced the protein expression levels of phosphorylated Akt, phosphorylated GSK3α/β, CaMKII, and GLUT2 (insulin-related signaling molecules), and they increased the protein expression levels of phosphorylated NFκB-p65 and Cox-2 (inflammation-related signaling molecules), as determined by a Western blot analysis. A bioinformatics analysis of Next-Generation Sequencing data suggested that exosome-carried microRNAs, such as miR-1224, -122-5p, -133a-3p, -10b-5p, and -423-5p, may affect GSIS in recipient β-cells. Taken together, these findings suggest that β-cell-derived exosomes may upregulate exosomal microRNA-associated signals to dysregulate glucose-stimulated insulin secretion in naïve β-cells.

The Nature and Nurture of Extracellular Vesicle-Mediated Signaling

In the last decade, it has become clear that extracellular vesicles (EVs) are a ubiquitous component of living systems. These small membrane-enclosed particles can confer diverse functions to the cells that release, capture, or coexist with them in an environment. We use examples across living systems to produce a conceptual framework that classifies three modes by which EVs exert functions: (a) EV release that serves a function for producing cells, (b) EV modification of the extracellular environment, and (c) EV interactions with, and alteration of, receiving cells. We provide an overview of the inherent properties of EVs (i.e., their nature) as well as factors in the environment and receiving cell (i.e., nurture) that determine whether transmission of EV cargo leads to functional cellular responses. This review broadens the context for ruminating on EV functions and highlights the emergent properties of EVs that define their role in biology and will shape their applications in medicine.

Harnessing exosomes for advanced osteoarthritis therapy

Exosomes are nanosized, lipid membrane vesicles secreted by cells, facilitating intercellular communication by transferring cargo from parent to recipient cells. This capability enables biological crosstalk across multiple tissues and cells. Extensive research has been conducted on their role in the pathogenesis of degenerative musculoskeletal diseases such as osteoarthritis (OA), a chronic and painful joint disease that particularly affects cartilage. Currently, no effective treatment exists for OA. Given that exosomes naturally modulate synovial joint inflammation and facilitate cartilage matrix synthesis, they are promising candidates as next generation nanocarriers for OA therapy. Recent advancements have focused on engineering exosomes through endogenous and exogenous approaches to enhance their joint retention, cartilage and chondrocyte targeting properties, and therapeutic content enrichment, further increasing their potential for OA drug delivery. Notably, charge-reversed exosomes that utilize electrostatic binding interactions with cartilage anionic aggrecan glycosaminoglycans have demonstrated the ability to penetrate the full thickness of early-stage arthritic cartilage tissue following intra-articular administration, maximizing their therapeutic potential. These exosomes offer a non-viral, naturally derived, cell-free carrier for OA drug and gene delivery applications. Efforts to standardize exosome harvest, engineering, and property characterization methods, along with scaling up production, will facilitate more efficient and rapid clinical translation. This article reviews the current state-of-the-art, explores opportunities for exosomes as OA therapeutics, and identifies potential challenges in their clinical translation.

Extracellular vesicle-mediated trafficking of molecular cues during human brain development

Cellular crosstalk is an essential process influenced by numerous factors, including secreted vesicles that transfer nucleic acids, lipids, and proteins between cells. Extracellular vesicles (EVs) have been the center of many studies focusing on neurodegenerative disorders, but whether EVs display cell-type-specific features for cellular crosstalk during neurodevelopment is unknown. Here, using human-induced pluripotent stem cell-derived cerebral organoids, neural progenitors, neurons, and astrocytes, we identify heterogeneity in EV protein content and dynamics in a cell-type-specific and time-dependent manner. Our results support the trafficking of key molecules via EVs in neurodevelopment, such as the transcription factor YAP1, and their localization to differing cell compartments depending on the EV recipient cell type. This study sheds new light on the biology of EVs during human brain development.

Extracellular Vesicle-Mediated Neuron-Glia Communications in the Central Nervous System

Communication between neurons and glia significantly influences the development maturation, plasticity, and disease progressions of the nervous system. As a new signaling modality, extracellular vesicles display a diverse role for robust functional regulation of neurons through their protein and nucleic acid cargoes. This review highlights recent breakthroughs in the research of signaling mechanisms between glia and neurons mediated by extracellular vesicles that are important for neural development, axonal maintenance, synaptic functions, and disease progression in the mammalian nervous system. We will discuss the biological roles of extracellular vesicles released from neurons, astroglia, microglia, and oligodendroglia in the nervous system and their implications in neurodegenerative disorders.

Unveiling exosomes: Cutting-edge isolation techniques and their therapeutic potential

Exosomes are one type of nanosized membrane vesicles with an endocytic origin. They are secreted by almost all cell types and play diverse functional roles. It is essential for research purposes to differentiate exosomes from microvesicles and isolate them from other components in a fluid sample or cell culture medium. Exosomes are important mediators in cell-cell communication. They deliver their cargos, such as mRNA transcripts, microRNA, lipids, cytosolic and membrane proteins and enzymes, to target cells with or without physical connections between cells. They are highly heterogeneous in size, and their biological functions can vary depending on the cell type, their ability to interact with recipient cells and transport their contents, and the environment in which they are produced. This review summarized the recent progress in exosome isolation and characterization techniques. Moreover, we review the therapeutic approaches, biological functions of exosomes in disease progression, tumour metastasis regulation, immune regulation and some ongoing clinical trials.

Extracellular Microvesicles vs. Mitochondria: Competing for the Top Spot in Cardiovascular Regenerative Medicine

Regenerative medicine aims to restore, replace, and regenerate human cells, tissues, and organs. Despite significant advancements, many cell therapy trials for cardiovascular diseases face challenges like cell survival and immune compatibility, with benefits largely stemming from paracrine effects. Two promising therapeutic tools have been recently emerged in cardiovascular diseases: extracellular vesicles (EVs) and mitochondrial transfer. Concerning EVs, the first pivotal study with EV-enriched secretome derived from cardiovascular progenitor cells has been done treating heart failure. This first in man demonstrated the safety and feasibility of repeated intravenous infusions and highlighted significant clinical improvements, including enhanced cardiac function and reduced symptoms in heart failure patients. The second study uncovered a novel mechanism of endothelial regeneration through mitochondrial transfer via tunneling nanotubes (TNTs). This research showed that mesenchymal stromal cells (MSCs) transfer mitochondria to endothelial cells, significantly enhancing their bioenergetics and vessel-forming capabilities. This mitochondrial transfer was crucial for endothelial cell engraftment and function, offering a new strategy for vascular regeneration without the need for additional cell types. Combining EV and mitochondrial strategies presents new clinical opportunities. These approaches could revolutionize regenerative medicine, offering new hope for treating cardiovascular and other degenerative diseases. Continued research and clinical trials will be crucial in optimizing these therapies, potentially leading to personalized medicine approaches that enhance patient outcomes.

Endoplasmic reticulum stress alters myelin associated protein expression and extracellular vesicle composition in human oligodendrocytes

Myelination of the central nervous system is mediated by specialized glial cells called oligodendrocytes (OLs). Multiple sclerosis (MS) is characterized by loss of myelination and subsequent clinical symptoms that can severely impact the quality of life and mobility of those affected by the disease. The major protein components of myelin sheaths are synthesized in the endoplasmic reticulum (ER), and ER stress has been observed in patients with MS. Extracellular vesicles (EVs) have been shown to carry bioactive cargo and have the potential to be utilized as noninvasive biomarkers for various diseases. In the current study, we sought to determine how ER stress in OLs affected the production of key myelination proteins and EV release and composition. To achieve this, tunicamycin was used to induce ER stress in a human oligodendroglioma cell line and changes in myelination protein expression and markers of autophagy were assessed. EVs were also separated from the conditioned cell culture media through size exclusion chromatography and characterized. Significant reductions in the expression of myelination proteins and alterations to autophagosome formation were observed in cells undergoing ER stress. EVs released from these cells were slightly smaller relative to controls, and had strong expression of LC3B. We also observed significant upregulation of miR-29a-3p in ER stress EVs when compared to controls. Taken together, these data suggest that ER stress negatively impacts production of key myelination proteins and induces cells to release EVs that may function to preemptively activate autophagic pathways in neighboring cells.

Small extracellular vesicles derived from synovial fibroblasts contain distinct miRNA profiles and contribute to chondrocyte damage in osteoarthritis

BACKGROUND

Small extracellular vesicles (sEV) derived from synovial fibroblasts (SF) represent a novel molecular mechanism regulating cartilage erosion in osteoarthritis (OA). However, a comprehensive evaluation using disease relevant cells has not been undertaken. The aim of this study was to isolate and characterise sEV from OA SF and to look at their ability to regulate OA chondrocyte effector responses relevant to disease. Profiling of micro (mi) RNA signatures in sEV and parental OA SF cells was performed.

METHODS

SF and chondrocytes were isolated from OA synovial membrane and cartilage respectively (n = 9). sEV were isolated from OA SF (± IL-1β) conditioned media by ultracentrifugation and characterised using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Particle size was confirmed by nanoparticle tracking analysis (NTA). sEV regulation of OA chondrocyte and cartilage effector response was evaluated using qPCR, ELISA and sulphated glycosaminoglycan assay (sGAG). RNA-sequencing was used to establish miRNA signatures in isolated sEV from OA SF.

RESULTS

OA SF derived sEV were readily taken up by OA chondrocytes, with increased expression of the catabolic gene MMP 13 (p < 0.01) and decreased expression of the anabolic genes aggrecan and COL2A1 (p < 0.01) observed. Treatment with sEV derived from IL-1β stimulated OA SF significantly decreased expression of aggrecan and COL2A1 (p < 0.001) and increased SOX 9 gene expression (p < 0.05). OA chondrocytes cultured with sEV from either non-stimulated or IL-1β treated OA SF, resulted in a significant increase in the secretion of IL-6, IL-8 and MMP-3 (p < 0.01). Cartilage explants cultured with sEV from SF (± IL-1β) had a significant increase in the release of sGAG (p < 0.01). miRNA signatures differed between parental SF cells and isolated sEV. The recently identified osteoclastogenic regulator miR182, along with miR4472-2, miR1302-3, miR6720, miR6087 and miR4532 were enriched in sEV compared to parental cells, p < 0.01. Signatures were similar in sEVs derived from non-stimulated or IL-1β stimulated SF.

CONCLUSIONS

OA SF sEV regulate chondrocyte inflammatory and remodelling responses. OA SF sEV have unique signatures compared to parental cells which do not alter with IL-1β stimulation. This study provides insight into a novel regulatory mechanism within the OA joint which could inform future targeted therapy.

Molecular and biochemical evaluation of oxidative effects of cord blood CD34+ MPs on hematopoietic cells

A graft source for allogeneic hematopoietic stem cell transplantation is umbilical cord blood, which contains umbilical cord blood mononuclear cells (MNCs and mesenchymal stem cells, both an excellent source of extracellular microparticles (MPs). MPs act as cell communication mediators, which are implicated in reactive oxygen species formation or detoxification depending on their origin. Oxidative stress plays a crucial role in both the development of cancer and its treatment by triggering apoptotic mechanisms, in which CD34+ cells are implicated. The aim of this work is to investigate the oxidative stress status and the apoptosis of HL-60 and mononuclear cells isolated from umbilical cord blood (UCB) following a 24- and 48-hour exposure to CD34 + microparticles (CD34 + MPs). The activity of superoxide dismutase, glutathione reductase, and glutathione S-transferase, as well as lipid peroxidation in the cells, were employed as oxidative stress markers. A 24- and 48-hour exposure of leukemic and mononuclear cells to CD34 + -MPs resulted in a statistically significant increase in the antioxidant activity and lipid peroxidation in both cells types. Moreover, CD34 + MPs affect the expression of BCL2 and FAS and related proteins and downregulate the hematopoietic differentiation program in both HL-60 and mononuclear cells. Our results indicate that MPs through activation of antioxidant enzymes in both homozygous and nonhomozygous cells might serve as a means for graft optimization and enhancement.

5-Fluorouracil treatment represses pseudouridine-containing miRNA export into extracellular vesicles

5-Fluorouracil (5-FU) has been used for chemotherapy for colorectal and other cancers for over 50 years. The prevailing view of its mechanism of action is inhibition of thymidine synthase leading to defects in DNA replication and repair. However, 5-FU is also incorporated into RNA causing defects in RNA metabolism, inhibition of pseudouridine modification, and altered ribosome function. We examined the impact of 5-FU on post-transcriptional small RNA modifications (PTxMs) and the expression and export of RNA into small extracellular vesicles (sEVs). EVs are secreted by all cells and contain a variety of proteins and RNAs that can function in cell-cell communication. We found that treatment of colorectal cancer (CRC) cells with 5-FU represses sEV export of miRNA and snRNA-derived RNAs, but promotes export of snoRNA-derived RNAs. Strikingly, 5-FU treatment significantly decreased the levels of pseudouridine on both cellular and sEV small RNA profiles. In contrast, 5-FU exposure led to increased levels of cellular small RNAs containing a variety of methyl-modified bases. These unexpected findings show that 5-FU exposure leads to altered RNA expression, base modification, and aberrant trafficking and localization of small RNAs.

Extracellular vesicle therapy in neurological disorders

Extracellular vesicles (EVs) are vital for cell-to-cell communication, transferring proteins, lipids, and nucleic acids in various physiological and pathological processes. They play crucial roles in immune modulation and tissue regeneration but are also involved in pathogenic conditions like inflammation and degenerative disorders. EVs have heterogeneous populations and cargo, with numerous subpopulations currently under investigations. EV therapy shows promise in stimulating tissue repair and serving as a drug delivery vehicle, offering advantages over cell therapy, such as ease of engineering and minimal risk of tumorigenesis. However, challenges remain, including inconsistent nomenclature, complex characterization, and underdeveloped large-scale production protocols. This review highlights the recent advances and significance of EVs heterogeneity, emphasizing the need for a better understanding of their roles in disease pathologies to develop tailored EV therapies for clinical applications in neurological disorders.

Therapeutic potential of adipose-derived stem cell extracellular vesicles: from inflammation regulation to tissue repair

Inflammation is a key pathological feature of many diseases, disrupting normal tissue structure and resulting in irreversible damage. Despite the need for effective inflammation control, current treatments, including stem cell therapies, remain insufficient. Recently, extracellular vesicles secreted by adipose-derived stem cells (ADSC-EVs) have garnered attention for their significant anti-inflammatory properties. As carriers of bioactive substances, these vesicles have demonstrated potent capabilities in modulating inflammation and promoting tissue repair in conditions such as rheumatoid arthritis, osteoarthritis, diabetes, cardiovascular diseases, stroke, and wound healing. Consequently, ADSC-EVs are emerging as promising alternatives to conventional ADSC-based therapies, offering advantages such as reduced risk of immune rejection, enhanced stability, and ease of storage and handling. However, the specific mechanisms by which ADSC-EVs regulate inflammation under pathological conditions are not fully understood. This review discusses the role of ADSC-EVs in inflammation control, their impact on disease prognosis, and their potential to promote tissue repair. Additionally, it provides insights into future clinical research focused on ADSC-EV therapies for inflammatory diseases, which overcome some limitations associated with cell-based therapies.