A brief history of nearly EV-erything - The rise and rise of extracellular vesicles

Small extracellular vesicles derived from cerebral endothelial cells with elevated microRNA 27a promote ischemic stroke recovery

JOURNAL/nrgr/04.03/01300535-202501000-00030/figure1/v/2024-05-14T021156Z/r/image-tiff Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery. Our previous in vitro study demonstrated that exosomes/small extracellular vesicles (sEVs) isolated from cerebral endothelial cells (CEC-sEVs) of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a (miR-27a) is an elevated miRNA in ischemic CEC-sEVs. In the present study, we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a (27a-sEVs) further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs. 27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector. Small EVs isolated from CECs transfected with a scramble vector (Scra-sEVs) were used as a control. Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs. An array of behavior assays was used to measure neurological function. Compared with treatment of ischemic stroke with Scra-sEVs, treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side, and significantly improved neurological outcomes. In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth. Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone, while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a, and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone. Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs. Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes. Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.

Lung contusion complicated by pneumonia worsens lung injury via the inflammatory effect of alveolar small extracellular vesicles on macrophages and epithelial cells

BACKGROUND

Lung contusion (LC) complicated by pneumonia is associated with a higher risk of acute lung injury (ALI) mediated by activation of immune cells and injury to the lung epithelium. Small extracellular vesicles (sEVs) are essential mediators of cellular crosstalk; however, their role in the development of postinjury ALI remains unclear. We hypothesized that LC complicated by pneumonia increases the pro-inflammatory effect of alveolar sEVs on macrophages and the cytotoxicity of alveolar sEVs to pulmonary epithelial cells, worsening the severity of ALI.

METHODS

Studies in C57BL/6 mice were designed with four groups: sham, LC, Pneumonia (Pneu), and LC + Pneu. Lung contusion was induced by a cortical controlled impactor, while pneumonia was conducted by intratracheal injection of 10 5 cfu Pseudomonas aeruginosa . Bronchoalveolar lavage fluid (BAL) was harvested 24 hours postinfection, and sEVs were purified by centrifugation and size exclusion chromatography. To evaluate the effect of alveolar sEV on cells, sEVs from each group were cocultured with macrophages (RAW 264.7) to assess cytokine release and lung epithelial cells (MLE 12) to assess epithelial cytotoxicity.

RESULTS

The LC + Pneu group severely injured lungs histologically and increased the susceptibility to the bacteria. The LC + Pneu group showed higher concentrations of proteins, macrophage inflammatory protein 1-alpha (MIP1α), and intercellular adhesion molecule 1 (ICAM-1) in BAL. MIP1α and ICAM-1 expression in the macrophages increased after incubation with sEVs from the LC + Pneu group. Moreover, the sEVs demonstrated higher cytotoxicity to epithelial cells and increased apoptosis in epithelial cells after incubation with sEVs from the LC + Pneu group.

CONCLUSION

Lung contusion complicated by pneumonia increased the pro-inflammatory effect of alveolar sEVs on macrophages and the cytotoxicity of alveolar sEVs to pulmonary epithelial cells, worsening the severity of ALI. These results demonstrate the potential importance of alveolar sEVs in lung inflammation following a bacterial infection after trauma.

Biophysical Profiling of Protein Corona on Red Blood Cell-Derived Extracellular Vesicles (REVs): Linear Dichroism and Microfluidic Resistive Pulse Sensing Separate Surface Clearing from Vesicle Disruption

Extracellular vesicles (EVs) have attracted significant scientific attention due to their critical functions in intercellular communication and their possible uses in diverse fields such as immunology, therapeutics, reproductive biology, biotechnology, and medicine. EVs are engulfed in a layer of proteins, also known as protein corona, which is speculated to play roles in several areas, from intercellular communication through immune recognition to cargo delivery. The composition of the protein corona strongly depends on the origin and the biological environment of EVs. Understanding the protein corona opens doors to finding various applications for vesicles by manipulating them. Typical ways of protein corona removal involve applying high salt concentration or the use of surface-active biomolecules, such as peptides, but this can result in EV membrane damage or complete vesicle disruption. Here, we describe a protocol for characterizing the change in protein corona content on red blood cell-derived EVs (REVs) by using linear dichroism spectroscopy (LD) with microfluidic resistive pulse sensing (MRPS). LD can quantify the change in the amount of the surface attached hemoglobins but cannot identify whether these changes are due to vesicle disruption or protein corona removal from intact vesicles. This necessitates the use of MRPS, which counts the number of vesicles before and after adding a surface manipulating compound. Thus it can identify whether the change in LD signal is due to vesicle disruption or due to loss of protein corona. The combined methods can be employed to understand which process takes place in which ratio, allowing the optimization of vesicle engineering toward specific needs.

Extracellular Vesicles From Bone Marrow-Derived Macrophages Enriched in ARG1 Enhance Microglial Phagocytosis and Haematoma Clearance Following Intracerebral Haemorrhage

Microglial phagocytosis of haematomas is crucial for neural functional recovery following intracerebral haemorrhage (ICH), a process regulated by various factors from within and outside the central nervous system (CNS). Extracellular vesicles (EVs), significant mediators of intercellular communication, have been demonstrated to play a pivotal role in the pathogenesis and progression of CNS diseases. However, the regulatory role of endogenous EVs on the phagocytic capacity of microglia post-ICH remains elusive. Utilising multi-omics analysis of brain tissue-derived EVs proteomics and single-cell RNA sequencing, this study identified that bone marrow-derived macrophages (BMDMs) potentially enhance microglial phagocytosis via EVs following ICH. By blocking BMDMs and reducing ARG1 in BMDM-derived EVs, we demonstrated that BMDMs facilitate erythrophagocytosis by delivering ARG1 to microglia via EVs post-ICH. EVs-carried ARG1 was found to augment phagocytosis by promoting RAC1-dependent cytoskeletal remodelling in microglia. Collectively, this research uncovers an intercellular communication pathway from BMDMs to microglia mediated by EVs post-ICH. This provides a novel paradigm for EV-mediated intercellular communication mechanisms and suggests a promising therapeutic potential for BMDM-derived EVs in the treatment of ICH.

Harnessing the therapeutic potential of exercise in extracellular vesicle-based therapy in metabolic disease associated cardiovascular complications

Cardiovascular disease (CVD) is a leading cause of mortality, affecting ∼18 million individuals each year. Obesity and type 2 diabetes mellitus in particular, both chronic metabolic disorders, are risk factors for CVD. The salutary effects of physical activity in preventing and ameliorating CVD have long been acknowledged, as it improves glucose and lipid homeostasis, alongside attenuating oxidative damage, increasing mitochondrial function, and ultimately improving cardiac function. Exercise serves as a catalyst for the secretion of extracellular vesicles (EVs), facilitating inter-tissue communication, by which tissues can deliver important signals from one tissue to another. In recent years, an increasing number of studies have focused on the cargo encapsulated within exercise-derived EVs, as well as the orchestration of inter-tissue crosstalk aimed at modulating metabolism and tissue function in CVDs. The precise mechanisms underpinning the cardioprotective properties of exercise-derived EVs, however, remains only partially elucidated. This review explores novel EV based therapeutic options in CVD and, in particular, EVs derived from models of exercise to alter metabolism and enhance cardiovascular outcomes.

An improvised one-step OptiPrep cushion ultracentrifugation method for outer membrane vesicles isolation of Klebsiella pneumoniae

BACKGROUND

Extracellular vesicles (EVs) play a crucial role in intraspecies and interspecies communication, significantly influencing physiological and pathological processes. Outer membrane vesicles (OMVs) secreted by Gram-negative bacteria are rich in components from the parent cells and are important for bacterial communication, immune evasion, and pathogenic mechanisms. However, the extraction and purification of OMVs face numerous challenges due to their small size and heterogeneity.

RESULTS

This study proposes an innovative strategy that combines traditional differential centrifugation (DC) with one-step ultracentrifugation (ODG) to develop a dual differential gradient centrifugation (DDGC) method for extracting outer membrane vesicles from Klebsiella pneumoniae. By comparing the DC and DDGC extraction methods, we found that OMVs extracted by DDGC exhibited more typical morphology, clearer backgrounds, and more uniform particle size distribution. The lipid polysaccharide (LPS) content in OMVs extracted by DDGC was significantly higher than that obtained by DC, and the outer membrane protein content was also greater, demonstrating enhanced biological activity. Biological activity assays indicated that OMVs extracted by DDGC showed stronger cytotoxicity to A549 lung epithelial cells, a significant decrease in cell viability, and higher levels of inflammatory factor expression(IL-6, TNF-α, IL-1β, and IL-8).

CONCLUSION

Our study demonstrates the advantages of the DDGC method in extracting K. pneumoniae OMVs, showing improvements in morphology, particle size distribution, protein content, and biological activity. This provides a solid foundation for further exploration of the biological functions of OMVs and their potential applications in the biomedical field.

Dual role of extracellular vesicles in neurodegenerative diseases

Extracellular vesicles (EVs) are cell-to-cell interaction tools that are attracting increasing interest in the literature in two opposing areas. In addition to their role in physiological development, there is growing evidence of their involvement in healing and protective processes. However, EVs also mediate pathological conditions, particularly contributing to the progression of several chronic diseases, such as neurodegenerative diseases. On the other hand, EVs also form the core of a new therapeutic strategy for neuroprotection, which is based on the administration of EVs derived from a wide range of donor cells. In particular, the possibility of obtaining numerous EVs from stem cells of different origins, which is feasible for therapeutic aims, is now under investigation. In this review, we focused on neurodegenerative diseases, in which EVs could have a propagative detrimental effect or could also be exploited to deliver protective factors. This review explores the different hypotheses concerning the dual role of EVs, with the aim of shedding light on the following question: Can vesicles be used to fight vesicle-propagated diseases?

Protective effects of miR-24-2-5p in early stages of breast cancer bone metastasis

BACKGROUND

Bone is the most frequent site of metastasis for breast cancer (BC). Metastatic BC cells interact with bone cells, including osteoclasts and osteoblasts, creating a cancer niche where they seed and proliferate. MicroRNAs (miRNAs) are regulators of breast-to-bone metastasis progression. MiR-24-2-5p has previously been shown to have roles in both breast cancer progression and inhibition of osteogenic differentiation. However, a direct link between miR-24-2-5p activity and the onset of bone metastasis remains ill-defined.

METHODS

Analysis of the expression of miR-24 forms (miR-24-2-5p, miR-24-3p, miR-24-1-5p) in the serum from early-stage BC patients at baseline (time of surgery) was conducted. MiR-24-2-5p overexpression in BC cells (NW1, a luc2-positive subpopulation of MDA-MB-231, and MCF7) was obtained by miRNA mimic transfection or lentivirus transduction. MiR-24-2-5p downregulation in BC cells (ZR-75-1, T-47D, SK-BR-3) was obtained by miRNA inhibitor transfection. Cell proliferation, migration and/or invasion assays were performed to assess BC cell functions after modulation of miR-24-2-5p expression. An animal model was used to assess the effect of miR-24-2-5p overexpression on early BC metastasis formation, as judged by bioluminescence imaging, and on bone remodelling, following measurement of circulating bone resorption (CTX-I) and bone formation (P1NP) markers. The effect of conditioned medium from miR-24-2-5p-overexpressing BC cells on human and murine osteoclast differentiation was investigated. Endogenous miR-24-2-5p expression levels were also quantified during murine osteoclast differentiation. RNA-sequencing (RNA-seq) analysis of BC cells was performed to evaluate transcriptomic changes associated with miR-24-2-5p overexpression. Selected modulated transcripts upon miR-24-2-5p overexpression were further validated by real-time qPCR.

RESULTS

Low expression levels of miR-24-2-5p, but not other miR-24 forms (miR-24-3p, miR-24-1-5p), in the serum from early-stage BC patients were associated with a high risk to develop future (bone) metastases. MiR-24-2-5p was also present in small extracellular vesicles secreted from BC cells. Forced expression of miR-24-2-5p in BC cells (NW1, MCF7) reduced their malignant traits (migration, invasion, and proliferation) in vitro. Furthermore, miR-24-2-5p overexpression in NW1 cells reduced metastasis, particularly in bone, and decreased bone turnover in vivo. RNA-seq and real-time qPCR analyses of NW1 and MCF7 cells overexpressing miR-24-2-5p showed the downregulation of common transcripts (CNNM4, DCTD, FMR1, PIGS, HLA-A, ICK, SH3BGRL2, WDFY, TRAF9B, IL6ST, PEX10, TRIM59). The conditioned medium from BC cells overexpressing miR-24-2-5p decreased human and murine osteoclast differentiation in vitro. Additionally, endogenous miR-24-2-5p expression levels in murine bone marrow-derived monocytes decreased during their differentiation into osteoclasts, further suggesting an inhibitory role for miR-24-2-5p during osteoclastogenesis.

CONCLUSION

MiR-24-2-5p exerts multiple protective roles in the early steps of BC bone metastasis by reducing malignant BC cell traits and tumour cell dissemination in bone, as well as by reducing the differentiation of precursors into mature osteoclasts.

Polyamine-Enriched Exosomes from Leishmania donovani Drive Host Macrophage Polarization via Immunometabolism Reprogramming

Leishmania donovani (Ld) promastigotes secrete exosomes that are crucial in host-pathogen interactions and intercellular communication by carrying parasite-specific molecules. Although the composition of cargos in Leishmania exosomes is known, the effects of the unique metabolic repertoire on immunometabolism rewiring of macrophage polarization are poorly understood. Interestingly, we found the enrichment of polyamines (PAs) such as spermidine and putrescine in the Ld-exosomes. Herein, we investigate the critical polycationic molecules and their crucial role in parasite survival. Our study shows that PA inhibition or depletion significantly impairs parasite growth and fitness, particularly in drug-resistant strains. Furthermore, we aimed to elucidate the impact of PAs-enriched Ld-exosomes on host macrophages. The data demonstrated that macrophages efficiently internalized these exosomes, leading to heightened phagocytic activity and infectivity. In addition, internalized Ld-exosomes induced M2 macrophage polarization characterized by elevated Arginase-1 expression and activity. The increased expression of the solute carrier gene (SLC3A2) and elevated intracellular spermidine levels suggest that Ld-exosomes contribute to the host PAs pool and create an anti-inflammatory milieu. These findings highlight the essential role of PAs-enriched Ld-exosomes in parasite survival and establishing a pro-parasitic environment in the host macrophage.

Extracellular Vesicles: Biology and Therapeutic Applications

Extracellular vesicles (EVs) are phospholipid-bilayer-limited particles in the extracellular space, without self-replicating capabilities [...].

From isolation to detection, advancing insights into endothelial matrix-bound vesicles

Matrix-bound vesicles (MBVs), an integral part of the extracellular matrix (ECM), are emerging as pivotal factors in ECM-driven molecular signaling. This study is the first to report the isolation of MBVs from porcine arterial endothelial cell basement membranes (A-MBVs) and thyroid cartilage (C-MBVs), the latter serving as a negative control due to its minimal vascular characteristics. Using Transmission Electron Microscopy (TEM), Nano-Tracking Analysis (NTA), Electrochemical Impedance Spectroscopy (EIS), and Atomic Force Microscopy (AFM), we orthogonally characterized the isolated MBVs. We detected the presence and preservation of vascular endothelial cadherin (CD144) in A-MBVs, its low to non-detetcted in C-MBVs, in which SOX9, a chondrocyte marker, was detected. Moreover, we developed a prototype of an immuno-functionalized screen-printed electrode designed for the immunoadsorption of CD144+ MBVs. This device facilitated the electrochemical detection of the targeted vesicles and allowed for their subsequent topological characterization using AFM, which verified the integrity and morphology of CD144+ MBVs post-immunoadsorption. These advancements enhance our comprehension of MBVs as conveyors of tissue-specific signals and pioneer new avenues for harnessing their cargo in biomedical applications. This research sets a significant precedent for future studies on the application of MBVs in regenerative medicine and ECM signaling.

Role and therapeutic perspectives of extracellular vesicles derived from liver and adipose tissue in metabolic dysfunction-associated steatotic liver disease

The global epidemic of metabolic diseases has led to the emergence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), which pose a significant threat to human health. Despite recent advances in research on the pathogenesis and treatment of MASLD/MASH, there is still a lack of more effective and targeted therapies. Extracellular vesicles (EVs) discovered in a wide range of tissues and body fluids encapsulate different activated biomolecules and mediate intercellular communication. Recent studies have shown that EVs derived from the liver and adipose tissue (AT) play vital roles in MASLD/MASH pathogenesis and therapeutics, depending on their sources and intervention types. Besides, adipose-derived stem cell (ADSC)-derived EVs appear to be more effective in mitigating MASLD/MASH. This review presents an overview of the definition, extraction strategies, and characterisation of EVs, with a particular focus on the biogenesis and release of exosomes. It also reviews the effects and potential molecular mechanisms of liver- and AT-derived EVs on MASLD/MASH, and emphasises the contribution and clinical therapeutic potential of ADSC-derived EVs. Furthermore, the future perspective of EV therapy in a clinical setting is discussed.

Single step capture and assessment of multiple plasma extracellular vesicle biomarkers in Alzheimer's disease detection

BACKGROUND

Blood tests for Alzheimer's disease (AD) that measure biomarkers related to neuropathology have demonstrated to be useful, minimally-invasive ways to identify patients for screening into clinical trials. While some AD biomarkers can be detected in plasma, greater sensitivity is needed to make plasma AD tests more effective. Extracellular vesicles (EVs) in plasma carry AD-related biomarkers from the brain and could offer a concentrated source of brain-related biomarkers, though the methodological complexities involved in isolating plasma EVs have hampered its validation for clinical use.

OBJECTIVE

To explore the feasibility and effectiveness of developing blood tests for AD utilizing extracellular vesicle-bound protein biomarkers.

METHODS

We developed a simplified method for isolating EVs directly from plasma using an alternating current electrokinetic (ACE) microchip. No sample pretreatment steps were needed. Protein biomarkers on the EVs were detected by adding fluorescent antibodies to the plasma samples before capture by the chip. This allowed measurement of EV biomarker levels directly on the chip.

RESULTS

AD or non-AD control plasma was measured for ten different AD-related biomarkers. EV-associated NCAM1, pTau231, α-synuclein, and TDP-43 levels were able to distinguish a group of 10 AD, 10 mild cognitive impairment (MCI), and 10 non-AD subjects. pTau231 was different between AD and non-AD (p = 0.0300) and α-synuclein differentiated AD from MCI (p = 0.0148).

CONCLUSIONS

This study shows how ACE microfluidic chip technology can help differentiate AD and MCI patients from non-AD controls with clinical relevance. This work also highlights the important diagnostic role of plasma EV biomarkers in neurodegenerative disease.

Microvesicle-eluting nano-engineered implants influence inflammatory response of keratinocytes

Besides enhancing osseo- and soft tissue integration, modulating inflammation at the implant site is also crucial for dental implant success. Uncontrolled peri-implant inflammation can cause significant loss of surrounding tissue and implant failure. It was recently shown that microvesicles (MVs), a less-studied type of extracellular vesicles, play a crucial role in cell-to-cell communication and may modulate angiogenesis and inflammatory response. The effect of MVs on regulating inflammation at an implant site, however, remains unexplored. In the current study, MVs were isolated and characterised from human primary gingival fibroblasts (hGFs) and loaded within titania nanotubes (TNTs, fabricated via anodisation on 3D Ti wire implants) towards their local release. The modified implants were characterised using SEM and confocal imaging to confirm the loading and local release of MVs from TNTs. In vitro studies demonstrated the internalisation of hGFs-MVs by human gingival keratinocytes (OKF6/TERT2 cell line), which caused a significant reduction in the production of pro-inflammatory cytokines. The results support MVs-releasing TNTs as a promising implant surface modification strategy to reduce inflammation, paving the way for further advancements in therapeutic dental implants.

A "poly-matter network" conception of biological inheritance

Here we intend to shift the "DNA- and information-centric" conception of biological inheritance, with the accompanying exclusion of any non-DNA matter, to a "poly-matter network" framework which, in addition to DNA, considers the action of other cellular membranous constituents. These cellular structures, in particular organelles and plasma membranes, express "landscapes" of specific topologies at their surfaces, which may become altered in response to certain environmental factors. These so-called "membranous environmental landscapes" (MELs), which replicate by self-organization / autopoiesis rather than self-assembly, are transferred from donor to acceptor cells by various - vesicular and non-vesicular - mechanisms and exert novel features in the acceptor cells. The "DNA-centric" conception may be certainly explanatorily sufficient for the transfer of heritable phenotype variation to acceptor cells following the copying of DNA in donor cells and thereby for the phenomenon of biological inheritance of traits. However, it is not causally sufficient. With the observation of phenotype variation, as initially manifested during bacterial transformation, the impact of environmental factors, such as nutrition and stress, in the differential regulation of gene expression has been widely accepted and resulted in intense efforts to resolve the underlying epigenetic mechanisms. However, these are explained under a conceptual frame where the DNA (and associated proteins) are the only matter of inheritance. In contrast, it is our argumentation that inheritance can only be adequately understood as the transfer of DNA in concert with non-DNA matter in a "poly-matter network" conception. The adequate inclusion of the transfer of non-DNA matter is still a desideratum of future genetic research, which may pave the way for the experimental elucidation not only of how DNA and membrane matter act in concert to enable the inheritance of innate traits, but also whether they interact for that of acquired biological traits. Moreover, the "poly-matter network" conception may open new perspectives for an understanding of the pathogenesis of "common complex" diseases.

miRNA packaging into small extracellular vesicles and implications in pain

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

Mesenchymal Stromal Cells for Aging Cartilage Regeneration: A Review

Cartilage degeneration is a key feature of aging and osteoarthritis, characterized by the progressive deterioration of joint function, pain, and limited mobility. Current treatments focus on symptom relief, not cartilage regeneration. Mesenchymal stromal cells (MSCs) offer a promising therapeutic option due to their capability to differentiate into chondrocytes, modulate inflammation, and promote tissue regeneration. This review explores the potential of MSCs for cartilage regeneration, examining their biological properties, action mechanisms, and applications in preclinical and clinical settings. MSCs derived from bone marrow, adipose tissue, and other sources can self-renew and differentiate into multiple cell types. In aging cartilage, they aid in tissue regeneration by secreting growth factors and cytokines that enhance repair and modulate immune responses. Recent preclinical studies show that MSCs can restore cartilage integrity, reduce inflammation, and improve joint function, although clinical translation remains challenging due to limitations such as cell viability, scalability, and regulatory concerns. Advancements in MSC delivery, including scaffold-based approaches and engineered exosomes, may improve therapeutic effectiveness. Potential risks, such as tumorigenicity and immune rejection, are also discussed, emphasizing the need for optimized treatment protocols and large-scale clinical trials to develop effective, minimally invasive therapies for cartilage regeneration.

Nucleic acid drugs: recent progress and future perspectives

High efficacy, selectivity and cellular targeting of therapeutic agents has been an active area of investigation for decades. Currently, most clinically approved therapeutics are small molecules or protein/antibody biologics. Targeted action of small molecule drugs remains a challenge in medicine. In addition, many diseases are considered 'undruggable' using standard biomacromolecules. Many of these challenges however, can be addressed using nucleic therapeutics. Nucleic acid drugs (NADs) are a new generation of gene-editing modalities characterized by their high efficiency and rapid development, which have become an active research topic in new drug development field. However, many factors, including their low stability, short half-life, high immunogenicity, tissue targeting, cellular uptake, and endosomal escape, hamper the delivery and clinical application of NADs. Scientists have used chemical modification techniques to improve the physicochemical properties of NADs. In contrast, modified NADs typically require carriers to enter target cells and reach specific intracellular locations. Multiple delivery approaches have been developed to effectively improve intracellular delivery and the in vivo bioavailability of NADs. Several NADs have entered the clinical trial recently, and some have been approved for therapeutic use in different fields. This review summarizes NADs development and evolution and introduces NADs classifications and general delivery strategies, highlighting their success in clinical applications. Additionally, this review discusses the limitations and potential future applications of NADs as gene therapy candidates.

Extracellular vesicles derived from endothelial progenitor cells modified by Houshiheisan promote angiogenesis and attenuate cerebral ischemic injury via miR-126/PIK3R2

Angiogenesis following cerebral ischemia is crucial for restoring blood supply to the ischemic region. Extracellular vesicles (EVs) derived from endothelial progenitor cells (EPCs) offer potential therapeutic benefits in the treatment of cerebral ischemia. Houshiheisan (HSHS) has been shown to improve clinical outcomes in ischemic stroke patients, reduce cerebral ischemic damage in rats, and protect endothelial cells. However, the potential effects of HSHS-modified EPC-derived EVs (EVsHSHS) for cerebral ischemia remain unexplored. This study investigated the impact of EVsHSHS on angiogenesis using rats with permanent middle cerebral artery occlusion (pMCAO) and brain microvascular endothelial cells (BMECs) subjected to oxygen-glucose deprivation (OGD). Results demonstrated that EVsHSHS promoted the proliferation, migration, and tube formation of BMECs in vitro. In vivo, high doses of EVsHSHS exhibited better performance than equivalent doses of unmodified EPC-derived EVs in reducing cerebral infarction volume, improving cortical blood perfusion, decreasing neurological deficit scores, and increasing cortical microvessel density at day 7 post-modeling. The pro-angiogenic effects of EVsHSHS following cerebral ischemia were associated with the regulation of miR-126 and the PIK3R2/PI3K/AKT pathway.

A Reproducible Protocol for the Isolation of Malaria-Derived Extracellular Vesicles by Differential Centrifugation

Over the last few decades, malaria-derived extracellular vesicles (EVs) have gained increasing interest due to their role in disease pathophysiology and parasite biology. Unlike other EV research fields, the isolation of malaria EVs is not standardized, hampering inter-study comparisons. Most malaria EV studies isolate vesicles by the "gold-standard" technique of differential (ultra)centrifugation (DC). Here, we describe in detail an optimized and reproducible protocol for the isolation of malaria-derived EVs by DC. The protocol begins with a description of cultivating high-parasitemia, synchronous P. falciparum cultures that are the source of EV-containing conditioned culture media. The isolation protocol generates two EV subtypes, and we provide details of characterizing these distinct subtypes by analyzing human and parasite proteins by Western blot analysis. We identify some of these proteins as suitable markers for malaria EV subpopulations and subtypes.

High-throughput, multiplexed quantification, and sorting of single EVs at single-molecule level

We have developed a platform for the high-throughput, multiplexed, and ultra-sensitive profiling of individual extracellular vesicles (EVs) directly in plasma, which we call BDEVS - Agarose B ead-based D igital Single Molecule-Single EV S orting. Unlike conventional approaches, BDEVS achieves single molecule sensitivity and moderate multiplexing (demonstrated 3-plex) without sacrificing the throughput (processing ten thousand of EVs per minute) necessary to resolve EVs directly in human plasma. Our platform integrates rolling circle amplification (RCA) of EV surface proteins, which are cleaved from single EVs, and amplified within agarose droplets, followed by flow cytometry-based readout and sorting, overcoming steric hindrance, non-specific binding, and the lack of quantitation of multiple proteins on EVs that have plagued earlier approaches. We evaluated the analytical capabilities of BDEVS through head-to-head comparison with gold-standard technologies, and demonstrated a ∼100x improvement in the limit of detection of EV subpopulations. We demonstrate the high throughput (∼100k beads / minute) profiling of individual EVs for key immune markers PD-L1, CD155, and the melanoma tumor marker TYRP-1, and showed that BDEVS can precisely quantify and sort EVs, offering unprecedented resolution for analyzing tumor-immune interactions and detecting rare EV subpopulations in complex clinical specimens. We demonstrate BDEVS's potential as a transformative tool for EV-based diagnostics and therapeutic monitoring in the context of cancer immunology by analyzing plasma samples from patients with melanoma, where EV heterogeneity plays a critical role in disease progression and response to therapy.

Antibody-displaying extracellular vesicles for targeted cancer therapy

Extracellular vesicles (EVs) function as natural delivery vectors and mediators of biological signals across tissues. Here, by leveraging these functionalities, we show that EVs decorated with an antibody-binding moiety specific for the fragment crystallizable (Fc) domain can be used as a modular delivery system for targeted cancer therapy. The Fc-EVs can be decorated with different types of immunoglobulin G antibody and thus be targeted to virtually any tissue of interest. Following optimization of the engineered EVs by screening Fc-binding and EV-sorting moieties, we show the targeting of EVs to cancer cells displaying the human epidermal receptor 2 or the programmed-death ligand 1, as well as lower tumour burden and extended survival of mice with subcutaneous melanoma tumours when systemically injected with EVs displaying an antibody for the programmed-death ligand 1 and loaded with the chemotherapeutic doxorubicin. EVs with Fc-binding domains may be adapted to display other Fc-fused proteins, bispecific antibodies and antibody-drug conjugates.

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.

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

Shortcomings, limitations and gaps in physiological roles of extracellular vesicles in obesity

Extracellular vesicles (EVs) play a crucial role in mediating communication between cells across species and kingdoms. The intercellular communication facilitated by EVs through autocrine and paracrine signalling mechanisms is essential for cell survival, maintaining normal metabolic functions and ensuring overall bodily homeostasis and health. Extracellular vesicles are present in various bodily fluids, such as pleural effusions, plasma, breast milk, amniotic fluid, semen and saliva. Additionally, the generation and release of EVs contribute to the removal of cellular waste. Patients with obesity exhibit a higher release and amount of circulating EVs than individuals with normal weight. This increased EV release in obesity might contribute to the inflammatory state characteristic of this metabolic condition, because higher levels of pro-inflammatory molecules are found within their cargo. However, interpreting results related to EV abundance, cargo and biological actions can be complicated by several factors; these include variations in cell sources, a wide age range (from children to the elderly), a mix of females and males, medication use and health status, a range of body weights (from normal weight to morbid obesity) and differences between in vitro assays using cell lines versus primary cultures. This article addresses the shortcomings, limitations and gaps in knowledge, providing a framework for enhancing our understanding of the physiological effects of EVs on obesity.

Morphine-induced hyperalgesia impacts small extracellular vesicle miRNA composition and function

Morphine and other synthetic opioids are widely prescribed to treat pain. Prolonged morphine exposure can paradoxically enhance pain sensitivity in humans and nociceptive behavior in rodents. To better understand the molecular mechanisms underlying opioid-induced hyperalgesia, we investigated changes in miRNA composition of small extracellular vesicles (sEVs) from the serum of mice after a morphine treatment paradigm that induces hyperalgesia. We observed significant differential expression of 18 miRNAs in sEVs from morphine-treated mice of both sexes compared to controls. Several of these miRNAs were bioinformatically predicted to regulate cyclic AMP response element binding protein (CREB), a well-characterized transcription factor implicated in pain and drug addiction. We confirmed the binding and repression of Creb mRNA by miR-155 and miR-10a. We tested if serum-derived sEVs from morphine-treated mice could elicit nociceptive behavior in naïve recipient mice. Intrathecal injection of 1 μg sEVs did not significantly impact basal mechanical and thermal threshold in naïve recipient mice. However, prophylactic 1 μg sEV administration in recipient mice resulted in faster resolution of complete Freund's adjuvant-induced mechanical and thermal inflammatory hypersensitivity. Other behaviors assayed following administration of these sEVs were not impacted including sEV conditioned place preference and locomotor sensitization. These results indicate that morphine regulation of serum sEV composition can contribute to analgesia and suggest a potential for sEVs to be a non-opioid therapeutic intervention strategy to treat pain.

Extracellular vesicles in cancer: golden goose or Trojan horse

Intercellular communication can be mediated by direct cell-to-cell contact and indirect interactions through secretion of soluble chemokines, cytokines, and growth factors. Extracellular vesicles (EVs) have emerged as important mediators of cell-to-cell and cell-to-environment communications. EVs from tumor cells, immune cells, and stromal cells can remodel the tumor microenvironment and promote cancer cell survival, proliferation, metastasis, immune evasion, and therapeutic resistance. Most importantly, EVs as natural nanoparticles can be manipulated to serve as a potent delivery system for targeted cancer therapy. EVs can be engineered or modified to improve their ability to target tumors and deliver therapeutic substances, such as chemotherapeutic drugs, nucleic acids, and proteins, for the treatment of cancer. This review provides an overview of the biogenesis and recycling of EVs, discusses their roles in cancer development, and highlights their potential as a delivery system for targeted cancer therapy.

Reduced circulating CD63+ extracellular vesicle levels associate with atherosclerosis in hypercholesterolaemic mice and humans

AIMS

The association and co-isolation of low-density lipoproteins (LDL) and extracellular vesicles (EVs) have been shown in blood plasma. Here we explore this relationship to better understand the role of EVs in atherogenesis.

METHODS AND RESULTS

Wild type (WT), PCSK9-/-, and LDLR-/- C57BL/6 mice were used in this study. Eleven week-old male mice were fed high-fat diet (HFD) for 12 weeks or kept on normal diet until old age (22-months). Cardiac function was assessed by ultrasound, cholesterol was quantified with a colorimetric kit and circulating EVs were measured using flow cytometry. Plaques were analysed post-mortem using Oil-Red-O staining of the aortic arch. EVs were measured from platelet free blood plasma samples of normal and hypercholesterolaemic clinical patients. Based on annexin V and CD63 staining, we found a significant increase in EV levels in LDLR-/- and PCSK9-/- mice after HFD, but CD81 showed no significant change in either group. There was no significant change in plaque formation after HFD. PCSK9-/- mice show a favourable cardiac function after HFD. Blood cholesterol levels progressively increased during HFD, with LDLR-/- mice showing high levels while PCSK9-/- were significantly lowered compared to WT animals. In mice at old age, similar cholesterol levels were observed as in young mice. In old age, LDLR-/- mice showed significantly increased plaques. At old age, ejection fraction was decreased in all groups of mice, as were CD63+ EVs. Similarly to mice, in patients with hypercholesterolaemia, CD63+ EVs were significantly depleted.

CONCLUSIONS

This research demonstrates an inverse relationship between circulating EVs and cholesterol, making EVs a potential marker for cardiovascular disease (CVD). HFD causes reduced cardiac function, but atherosclerotic development is slowly progressing in hypercholesterolaemic models and only observed with old animals. These results also bring further evidence for the benefit of using of PCSK9 inhibitors as therapeutic agents in CVD.

Human Breast Milk Exosomes: Affecting Factors, Their Possible Health Outcomes, and Future Directions in Dietetics

Background: Human breast milk is a complex biological fluid containing multifaceted biological compounds that boost immune and metabolic system development that support the short- and long-term health of newborns. Recent literature suggests that human breast milk is a substantial source of nutrients, bioactive molecules, and exosomes. Objectives: This review examines the factors influencing exosomes noted in human milk and the impacts of exosomes on infant health. Furthermore, it discusses potential future prospects for exosome research in dietetics. Methods: Through a narrative review of the existing literature, we focused on exosomes in breast milk, exosome components and their potential impact on exosome health. Results: Exosomes are single-membrane extracellular vesicles of endosomal origin, with an approximate radius of 20-200 nm. They are natural messengers that cells secrete to transport a wide range of diverse cargoes, including deoxyribonucleic acid, ribonucleic acid, proteins, and lipids between various cells. Some studies have reported that the components noted in exosomes in human breast milk could be transferred to the infant and cause epigenetic changes. Thus, it can affect gene expression and cellular event regulation in several tissues. Conclusions: In this manner, exosomes are associated with several pathways, including the immune system, oxidative stress, and cell cycle, and they can affect the short- and long-term health of infants. However, there is still much to learn about the functions, effectiveness, and certain impacts on the health of human breast milk exosomes.

Tumor-derived EV miRNA signatures surpass total EV miRNA in supplementing mammography for precision breast cancer diagnosis

Background: With the rising global incidence and mortality rates of breast cancer, early diagnosis is becoming increasingly crucial. The World Health Organization (WHO) recommends mammography as a primary screening tool. However, despite its clinical benefits, mammography has potential risks including radiation exposure, unnecessary follow-up, and overdiagnosis due to false positives, particularly in cases of early cancer or dense breast tissue. In this study, we aimed to address these concerns by introducing an innovative diagnostic method that employs circulating biomarkers to enhance the existing screening techniques Methods: Breast cancer-derived extracellular vesicles (BEVs) were isolated from the bloodstream using advanced immunoaffinity capture techniques. Subsequently, we analyzed the microRNA (miRNA) profiles of BEVs in plasma samples from 120 patients with breast cancer, 46 with benign tumors, and 45 healthy controls. Results: This retrospective study identified a distinct signature of five EV miRNAs (miR-21, miR-106b, miR-181a, miR-484, and miR-1260b) that effectively differentiated patients with breast cancer from healthy controls. This signature provides essential insights into tumor progression, metastasis, and the risk of recurrence. Notably, overexpression of this signature correlated with poorer survival outcomes. Conclusions: Our novel gene signature-based approach not only complements existing diagnostic methods with high accuracy but also provides a deeper understanding of the molecular aspects of breast cancer, heralding a significant advancement in precision medicine and personalized cancer care.

Hijacking host extracellular vesicle machinery by hepatotropic viruses: current understandings and future prospects

Recent advances in studies exploring the roles of extracellular vesicles (EVs) in viral transmission and replication have illuminated hepatotropic viruses, such as hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV). While previous investigations have uncovered these viruses' ability to exploit cellular EV pathways for replication and transmission, most have focused on the impacts of exosomal pathways. With an improved understanding of EVs, four main subtypes, including exosomes, microvesicles, large oncosomes, and apoptotic bodies, have been categorized based on size and biogenic pathways. However, there remains a noticeable gap in comprehensive reviews summarizing recent findings and outlining future perspectives for EV studies related to hepatotropic viruses. This review aims to consolidate insights into EV pathways utilized by hepatotropic viruses, offering guidance for the future research direction in this field. By comprehending the diverse range of hepatotropic virus-associated EVs and their role in cellular communication during productive viral infections, this review may offer valuable insights for targeting therapeutics and devising strategies to combat virulent hepatotropic virus infections and the associated incidence of liver cancer.

Proteomic Characterization of Transfusable Blood Components: Fresh Frozen Plasma, Cryoprecipitate, and Derived Extracellular Vesicles via Data-Independent Mass Spectrometry

Extracellular vesicles (EVs) are a heterogeneous collection of particles that play a crucial role in cell-to-cell communication, primarily due to their ability to transport molecules, such as proteins. Thus, profiling EV-associated proteins offers insight into their biological effects. EVs can be isolated from various biological fluids, including donor blood components such as cryoprecipitate and fresh frozen plasma (FFP). In this study, we conducted a proteomic analysis of five single donor units of cryoprecipitate, FFP, and EVs derived from these blood components using a quantitative mass spectrometry approach. EVs were successfully isolated from both cryoprecipitate and FFP based on community guidelines. We identified and quantified approximately 360 proteins across all sample groups. Principal component analysis and heatmaps revealed that both cryoprecipitate and FFP are similar. Similarly, EVs derived from cryoprecipitate and FFP are comparable. However, they differ between the originating fluids and their derived EVs. Using the R-package MS-DAP, differentially expressed proteins (DEPs) were identified. The DEPs for all comparisons, when submitted for gene enrichment analysis, are involved in the complement and coagulation pathways. The protein profile generated from this study will have important clinical implications in increasing our knowledge of the proteins that are associated with EVs derived from blood components.

Lipidome profiling of neutrophil-derived extracellular vesicles unveils their contribution to the ensemble of synovial fluid-derived extracellular vesicles during joint inflammation

The molecular signature of cell-derived extracellular vesicles (EVs) from synovial fluid (SF) offers insights into the cells and molecular processes associated with joint disorders and can be exploited to define biomarkers. The EV-signature is determined by cargo molecules and the lesser-studied lipid bilayer. We here investigated the lipidome of SF-EVs in inflamed joints derived from Rheumatoid Arthritis (RA) and Spondyloarthritis (SpA) patients, two autoimmune-driven joint diseases, and compared these signatures to the lipid profile of equine SF-EVs obtained during induced acute synovitis. Since neutrophils are primary SF-infiltrating cells during these inflammatory joint diseases, we also analyzed how inflammatory stimuli alter the lipidomic profile of human and equine neutrophil-derived EVs (nEVs) in vitro and how these signatures relate to the lipidome signatures of SF-EVs from inflamed joints. We identified neutrophil stimulation intensity-dependent changes in the lipidomic profile of nEVs with elevated presence of dihexosylceramide (lactosylceramide), phosphatidylserine, and phosphatidylethanolamine ether-linked lipid classes in human nEVs upon full neutrophil activation. In horses, levels of monohexosylceramide (glucosylceramide) increased instead of dihexosylceramide, indicating species-specific differences. The lipid profiles of RA and SpA SF-EVs were relatively similar and showed a relative resemblance with stimulated human nEVs. Similarly, the lipidome of equine synovitis-derived SF-EVs closer resembled the one of stimulated equine nEVs. Hence, lipidome profiling can provide insights into the contribution of nEVs to the heterogeneous pool of SF-EVs, deepening our understanding of inflammatory joint diseases and revealing molecular changes in joint homeostasis, which can lead to the development of more precise disease diagnosis and treatment strategies.

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

Neuroserpin and Extracellular Vesicles in Ischemic Stroke: Partners in Neuroprotection?

Ischemic stroke represents a significant global health challenge, often resulting in death or long-term disability, particularly among the elderly, where advancing age stands as the most unmodifiable risk factor. Arising from the blockage of a brain-feeding artery, the only therapies available to date aim at removing the blood clot to restore cerebral blood flow and rescue neuronal cells from death. The prevailing treatment approach involves thrombolysis by administration of recombinant tissue plasminogen activator (tPA), albeit with a critical time constraint. Timely intervention is imperative, given that delayed thrombolysis increases tPA leakage into the brain parenchyma, causing harmful effects. Strategies to preserve tPA's vascular benefits while shielding brain cells from its toxicity have been explored. Notably, administering neuroserpin (Ns), a brain-specific tPA inhibitor, represents one such approach. Following ischemic stroke, Ns levels rise and correlate with favorable post-stroke outcomes. Studies in rodent models of focal cerebral ischemia have demonstrated the beneficial effects of Ns administration. Ns treatment maintains blood-brain barrier (BBB) integrity, reducing stroke volume. Conversely, Ns-deficient animals exhibit larger stroke injury, increased BBB permeability and enhanced microglia activation. Furthermore, Ns administration extends the therapeutic window for tPA intervention, underscoring its potential in stroke management. Remarkably, our investigation reveals the presence of Ns within extracellular vesicles (EVs), small membrane-surrounded particles released by all cells and critical for intercellular communication. EVs influence disease outcome following stroke through cargo transfer between cells. Clarifying the role of EVs containing NS could open up urgently needed novel therapeutic approaches to improve post-ischemic stroke outcome.

Shining a light on fluorescent EV dyes: Evaluating efficacy, specificity and suitability by nano-flow cytometry

Extracellular vesicles (EVs) are mediators of intercellular communication, recently recognised for their clinical applications. Accurate characterisation and quantification of EVs are critical for understanding of their function and clinical relevance. Many platforms utilise fluorescence for EV characterisation, frequently labelling surface proteins to identify EVs. The heterogeneity of EVs and the lack of a universal protein marker encourages the use of generic EV labelling methods, including membrane labelling. Using nano-flow cytometry, we evaluated six membrane dyes, including MemGlow and CellMask. Evaluation criteria included EV labelling efficacy, non-specific labelling of very low-density lipoproteins (VLDLs), brightness and dye aggregation. Significant variation was observed in dye performance, with certain dyes showing poor EV labelling efficacy or high affinity to VLDLs. Importantly, several promising candidates were identified for further investigation. Overall, this study highlights the importance of selecting appropriate membrane dyes for EV staining tailored to the aims of the study and the EV origin. MemGlow and CellMask proved favourable, allowing bright, sensitive staining of EV membranes with minimal aggregation. However, MemGlow showed an affinity to VLDLs, and CellMask requires additional sample handling for optimal labelling. These results contribute to deepening our understanding of EV membrane dyes, allowing for better dye selection and EV identification in future studies.

A critical systematic review of extracellular vesicle clinical trials

This systematic review examines the landscape of extracellular vesicle (EV)-related clinical trials to elucidate the field's trends in clinical applications and EV-related methodologies, with an additional focus on the acknowledgement of EV subpopulations. By analysing data from public reporting repositories, we catalogued 471 EV-related clinical trials to date, with indications for over 200 diseases. Diagnostics and companion diagnostics represented the bulk of EV-related clinical trials with cancer being the most frequent application. EV-related therapeutics trials mainly utilized mesenchymal stromal cell (MSC) EVs and were most frequently used for treatment of respiratory illnesses. Ultracentrifugation and RNA-sequencing were the most common isolation and characterization techniques; however, methodology for each was not frequently reported in study records. Most of the reported characterization relied on bulk characterization of EV isolates, with only 11% utilizing EV subpopulations in their experimental design. While this may be connected to a lack of available techniques suitable for clinical implementation, it also highlights the opportunity for use of EV subpopulations to improve translational efforts. As academic research identifies more chemically distinct subpopulations and technologies for their enrichment, we forecast to more refined EV trials in the near future. This review emphasizes the need for meticulous methodological reporting and consideration of EV subpopulations to enhance the translational success of EV-based interventions, pointing towards a paradigm shift in personalized medicine.

Contribution of extracellular vesicles to steatosis-related liver disease and their therapeutic potential

Extracellular vesicles (EVs) are small particles released by many cell types in different tissues, including the liver, and transfer specific cargo molecules from originating cells to receptor cells. This process generally culminates in activation of distant cells and inflammation and progression of certain diseases. The global chronic liver disease (CLD) epidemic is estimated at 1.5 billion patients worldwide. Cirrhosis and liver cancer are the most common risk factors for CLD. However, hepatitis C and B virus infection and obesity are also highly associated with CLD. Nonetheless, the etiology of many CLD pathophysiological, cellular, and molecular events are unclear. Changes in hepatic lipid metabolism can lead to lipotoxicity events that induce EV release. Here, we aimed to present an overview of EV features, from definition to types and biogenesis, with particular focus on the molecules related to steatosis-related liver disease, diagnosis, and therapy.

Exosomes as promising bioactive materials in the treatment of spinal cord injury

Patients with spinal cord injury (SCI) have permanent devastating motor and sensory disabilities. Secondary SCI is known for its complex progression and presents with sophisticated aberrant inflammation, vascular changes, and secondary cellular dysfunction, which aggravate the primary damage. Since their initial discovery, the potent neuroprotective effects and powerful delivery abilities of exosomes (Exos) have been reported in different research fields, including SCI. In this study, we summarize therapeutic advances related to the application of Exos in preclinical animal studies. Subsequently, we discuss the mechanisms of action of Exos derived from diverse cell types, including neurogenesis, angiogenesis, blood-spinal cord barrier preservation, anti-apoptosis, and anti-inflammatory potential. We also evaluate the relationship between the Exo delivery cargo and signaling pathways. Finally, we discuss the challenges and advantages of using Exos to offer innovative insights regarding the development of efficient clinical strategies for SCI.

Hitting the target: cell signaling pathways modulation by extracellular vesicles

Extracellular vesicles (EVs) are lipid bilayer-enclosed nanoparticles released outside the cell. EVs have drawn attention not only for their role in cell waste disposal, but also as additional tools for cell-to-cell communication. Their complex contents include not only lipids, but also proteins, nucleic acids (RNA, DNA), and metabolites. A large part of these molecules are involved in mediating or influencing signal transduction in target cells. In multicellular organisms, EVs have been suggested to modulate signals in cells localized either in the neighboring tissue or in distant regions of the body by interacting with the cell surface or by entering the cells via endocytosis or membrane fusion. Most of the EV-modulated cell signaling pathways have drawn considerable attention because they affect morphogenetic signaling pathways, as well as pathways activated by cytokines and growth factors. Therefore, they are implicated in relevant biological processes, such as embryonic development, cancer initiation and spreading, tissue differentiation and repair, and immune response. Furthermore, it has recently emerged that multicellular organisms interact with and receive signals through EVs released by their microbiota as well as by edible plants. This review reports studies investigating EV-mediated signaling in target mammalian cells, with a focus on key pathways for organism development, organ homeostasis, cell differentiation and immune response.

Unraveling the extracellular vesicle network: insights into ovarian cancer metastasis and chemoresistance

Ovarian cancer (OC) is one of the most prevalent and lethal gynecological malignancies, with high mortality primarily due to its aggressive nature, frequent metastasis, and resistance to standard therapies. Recent research has highlighted the critical role of extracellular vesicles (EVs) in these processes. EVs, secreted by living organisms and carrying versatile and bioactive cargoes, play a vital role in intercellular communication. Functionally, the transfer of cargoes orchestrates multiple processes that actively affect not only the primary tumor but also local and distant pre-metastatic niche. Furthermore, their unique biological properties position EVs as novel therapeutic targets and promising drug delivery systems, with potential profound implications for cancer patients.This review summarizes recent progress in EV biology, delving into the intricate mechanisms by which EVs contribute to OC metastasis and drug resistance. It also explores the latest advances and therapeutic potential of EVs in the clinical context of OC. Despite the progress made, EV research in OC remains in its nascent stages. Consequently, this review presents existing research limitations and suggests avenues for future investigation. Altogether, the review aims to elucidate the critical roles of EVs in OC and spotlight their promising potential in this field.

Two roads diverged in a cell: insights from differential exosome regulation in polarized cells

Exosomes are extracellular vesicles involved in intercellular signaling, carrying various cargo from microRNAs to metabolites and proteins. They are released by practically all cells and are highly heterogenous due to their origin and content. Several groups of exosomes are known to be involved in various pathological conditions including autoimmune, neurodegenerative, and infectious diseases as well as cancer, and therefore a substantial understanding of their biogenesis and release is crucial. Polarized cells display an array of specific functions originated from differentiated membrane trafficking systems and could lead to hints in untangling the complex process of exosomes. Indeed, recent advances have successfully revealed specific regulation pathways for releasing different subsets of exosomes from different sides of polarized epithelial cells, underscoring the importance of polarized cells in the field. Here we review current evidence on exosome biogenesis and release, especially in polarized cells, highlight the challenges that need to be combatted, and discuss potential applications related to exosomes of polarized-cell origin.

The Role of Extracellular Vesicles in the Treatment of Prostate Cancer

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

Differences in the proteome within extracellular vesicles between premalignant and malignant plasma cell disorders

BACKGROUND

Precursor plasma cell disorders such as monoclonal gammopathy of undetermined significance (MGUS) always precede the development of active malignancies such as multiple myeloma (MM). There is a need for novel biomarkers to identify those patients with such precursor plasma cell disorders who rapidly progress to MM. Plasma-derived extracellular vesicles (EVs) may serve as a reservoir of potential biomarkers that can shed light on the pathogenesis and disease biology of MM.

METHODS

This study isolated small EVs (SEVs) and large EVs (LEVs) from the platelet-poor peripheral blood plasma of MGUS (n = 9) and MM (n = 12) patients using the size exclusion chromatography-based method and evaluated their proteome using a label-free proteomics workflow.

RESULTS

In total, 2055 proteins were identified in SEVs, while 2794 proteins were identified in LEVs. The transferrin receptor (or CD71) protein was upregulated in both populations of EVs derived from MM patients compared to MGUS patients and was of prognostic significance. Similarly, three isoforms of serum amyloid A (SAA) protein, SAA1, SAA2, and SAA4, were also highly upregulated in SEVs within MM patients relative to MGUS patients. Finally, CD40 expression was also higher in the LEVs derived from MM patients than in MGUS patients.

CONCLUSIONS

This study demonstrates the feasibility of successfully isolating both SEVs and LEVs from the peripheral blood of patients with plasma cell disorders and quantifying protein biomarkers within these EVs that could be of prognostic and diagnostic interest.

Phospholipid-Anchored Ligand Conjugation on Extracellular Vesicles for Enhanced Cancer Targeting

Extracellular vesicles (EVs) are recognized as potential candidates for next-generation drug delivery systems. However, the inherent cancer-targeting efficiency is unsatisfactory, necessitating surface modification to attach cell-binding ligands. By utilizing phospholipase D from Streptomyces in combination with maleimide-containing primary alcohol, the authors successfully anchored ligands onto milk-derived EVs (mEVs), overcoming the issues of ligand leakage or functional alteration seen in traditional methods. Quantitative nano-flow cytometry demonstrated that over 90% of mEVs are effectively modified with hundreds to thousands of ligands. The resulting mEV formulations exhibited remarkable long-term stability in conjugation proportion, ligand number, size distribution, and particle concentration, even after months of storage. It is further shown that conjugating transferrin onto mEVs significantly enhanced cellular uptake and induced pronounced cytotoxic effects when loaded with paclitaxel. Overall, this study presents a highly efficient, stable, cost-effective, and scalable ligand conjugation approach, offering a promising strategy for targeted drug delivery of EVs.

Extracellular Vesicles as Mediators in Atherosclerotic Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease of the arterial intima, characterized by accumulation of lipoproteins and accompanying inflammation, leading to the formation of plaques that eventually trigger occlusive thrombotic events, such as myocardial infarction and ischemic stroke. Although many aspects of plaque development have been elucidated, the role of extracellular vesicles (EVs), which are lipid bilayer-delimited vesicles released by cells as mediators of intercellular communication, has only recently come into focus of atherosclerosis research. EVs comprise several subtypes that may be differentiated by their size, mode of biogenesis, or surface marker expression and cargo. The functional effects of EVs in atherosclerosis depend on their cellular origin and the specific pathophysiological context. EVs have been suggested to play a role in all stages of plaque formation. In this review, we highlight the known mechanisms by which EVs modulate atherogenesis and outline current limitations and challenges in the field.

Extracellular vesicles in cancer: challenges and opportunities for clinical laboratories

Extracellular vesicles (EVs) are nano-sized particles secreted by most cells. They transport different types of biomolecules (nucleic acids, proteins, and lipids) characteristic of their tissue or cellular origin that can mediate long-distance intercellular communication. In the case of cancer, EVs participate in tumor progression by modifying the tumor microenvironment, favoring immune tolerance and metastasis development. Consequently, EVs have great potential in liquid biopsy for cancer diagnosis, prognosis and follow-up. In addition, EVs could have a role in cancer treatment as a targeted drug delivery system. The intense research in the EV field has resulted in hundreds of patents and the creation of biomedical companies. However, methodological issues and heterogeneity in EV composition have hampered the advancement of EV validation trials and the development of EV-based diagnostic and therapeutic products. Consequently, only a few EV biomarkers have moved from research to clinical laboratories, such as the ExoDx Prostate IntelliScore (EPI) test, a CLIA/FDA-approved EV prostate cancer diagnostic test. In addition, the number of large-scale multicenter studies that would clearly define biomarker performance is limited. In this review, we will critically describe the different types of EVs, the methods for their enrichment and characterization, and their biological role in cancer. Then, we will specially focus on the parameters to be considered for the translation of EV biology to the clinic laboratory, the advances already made in the field of EVs related to cancer diagnosis and treatment, and the issues still pending to be solved before EVs could be used as a routine tool in oncology.