Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Stress-induced extracellular vesicles: insight into their altered proteomic composition and probable physiological role in cancer

EVs (extracellular vesicles) are phospholipid bilayer vesicles that can be released by both prokaryotic and eukaryotic cells in normal as well as altered physiological conditions. These vesicles also termed as signalosomes, possess a distinctive cargo comprising nucleic acids, proteins, lipids, and metabolites, enabling them to play a pivotal role in both local and long-distance intercellular communication. The composition, origin, and release of EVs can be influenced by different physiological conditions and a variety of stress factors, consequently affecting the contents carried within these vesicles. Therefore, identifying the modified contents of EVs can provide valuable insights into their functional role in stress-triggered communication. Particularly, this is important when EVs released from tumor microenvironment are investigated for their role in the development and dissemination of cancer. This review article emphasizes the importance of differential EV shedding and altered proteomic content in response to reduced oxygen concentration, altered levels of glucose and glutamine, pH variations, oxidative stress and Ca2+ ion concertation and it is subsequent effects on the behavior of recipient cells.

Extracellular Vesicles Released From Skeletal Muscle Post-Chronic Contractile Activity Increase Mitochondrial Biogenesis in Recipient Myoblasts

The effect of chronic contractile activity (CCA) on the biophysical properties and functional activity of skeletal muscle extracellular vesicles (Skm-EVs) is poorly understood due to challenges in distinguishing Skm-EVs originating from exercising muscle in vivo. To address this, myoblasts were differentiated into myotubes, and electrically paced (3 h/day, 4 days @ 14 V). CCA evoked an increase in mitochondrial biogenesis in stimulated versus non-stimulated (CON) myotubes as expected. EVs were isolated from conditioned media (CM) from control and stimulated myotubes using differential ultracentrifugation (dUC) and characterised biophysically using tunable resistive pulse sensing (TRPS, Exoid), TEM and western blotting. TEM images confirmed isolated round-shaped vesicles of about 30-150 nm with an intact lipid bilayer. EVs ranged from 98 to 138 nm in diameter, and the mean size was not altered by CCA. Zeta potential and total EV protein yield remained unchanged between groups, and total EV secretion increased after 4 days of CCA. Concomitant analysis of EVs after each day of CCA also demonstrated a progressive increase in CCA-EV concentration, whilst size and zeta potential remained unaltered, and EV protein yield increased in both CON-EVs and CCA groups. CCA-EVs were enriched with small-EVs versus CON-EVs, concomitant with higher expression of small-EV markers CD81, Tsg101 and HSP70. In whole cell lysates, CD63 and ApoA1 were reduced with CCA in myotubes, whereas CD81, Tsg101, Flotillin-1 and HSP70 levels remained unchanged. To evaluate the functional effect of EVs secreted post-CCA, we treated C2C12 myoblasts with all EVs isolated from CON or CCA myotubes after each day of stimulation, and measured cell count, cell viability, protein yield and mitochondrial biogenesis in recipient cells. There was no effect on cell count, viability and protein yield. Myoblasts treated with CCA-EVs exhibited increased mitochondrial biogenesis as indicated by enhanced MitoTracker Red staining, cytochrome c oxidase (COX) activity and protein expression of electron transport chain subunit, CIV-MTCO1. Further, CCA-EV treatment enhanced maximal oxygen consumption rates (OCR) in a dose-dependent manner, and ATP production in treated myoblasts. This increase in maximal OCR was abrogated when CCA-EVs pre-treated with proteinase K were co-cultured with myoblasts, indicating the pro-metabolic effect was likely mediated by transmembrane or peripheral membrane proteins in CCA-EVs. Our data highlight the novel effect of Skm-EVs isolated post-CCA in mediating pro-metabolic effects in recipient cells and thereby transmitting the effects associated with traditional exercise. Further investigation to interrogate the underlying mechanisms involved in downstream cellular metabolic adaptations is warranted.

Unravelling Plasma Extracellular Vesicle Diversity With Optimised Spectral Flow Cytometry

Extracellular vesicles (EVs) are crucial for intercellular communication and are found in various biological fluids. The identification and immunophenotyping of such small particles continue to pose significant challenges. Here, we have developed a workflow for the optimisation of a next-generation panel for in-depth immunophenotyping of circulating plasma EVs using spectral flow cytometry. Our data collection followed a multistep optimisation phase for both instrument setup and 21-colour panel design, thus maximising fluorescent signal recovery. This spectral approach enabled the identification of novel EV subpopulations. Indeed, besides common EVs released by erythrocytes, platelets, leukocytes and endothelial cells, we observed rare and poorly known EV subsets carrying antigens related to cell activation or exhaustion. Notably, the unsupervised data analysis of major EV subsets revealed subpopulations expressing up to five surface antigens simultaneously. However, the majority of EVs expressed only a single surface antigen, suggesting they may not fully represent the phenotype of their parent cells. This is likely due to the small surface area or the biogenesis of EVs rather than antibody steric hindrance. Finally, we tested our workflow by analysing the plasma EV landscape in a cohort of systemic lupus erythematosus (SLE) patients. Interestingly, we observed a significant increase in CD54+ EVs, supporting the notion of elevated circulating ICAM under SLE conditions. To our knowledge, these are the first data highlighting the importance of a spectral flow cytometry approach in deciphering the heterogeneity of plasma EVs paving the way for the routine use of a high-dimensional immunophenotyping in EV research.

Nanoscopic Profiling of Small Extracellular Vesicles via High-Speed Atomic Force Microscopy (HS-AFM) Videography

Small extracellular vesicles (sEVs), which carry lipids, proteins and RNAs from their parent cells, serve as biomarkers for specific cell types and biological states. These vesicles, including exosomes and microvesicles, facilitate intercellular communication by transferring cellular components between cells. Current methods, such as ultracentrifugation and Tim-4 affinity method, yield high-purity sEVs. However, despite their small size, purified sEVs remain heterogeneous due to their varied intracellular origins. In this technical note, we used high-speed atomic force microscopy (HS-AFM) in conjunction with exosome markers (IgGCD63 and IgGCD81) to explore the intracellular origins of sEVs at single-sEV resolution. Our results first revealed the nanotopology of HEK293T-derived sEVs under physiological conditions. Larger sEVs (diameter > 100 nm) exhibited greater height fluctuations compared to smaller sEVs (diameter ≤ 100 nm). Next, we found that mouse-origin IgGCD63, and rabbit-origin IgGcontrol and IgGCD81, exhibited the iconic 'Y' conformation, and similar structural dynamics properties. Last, exosome marker antibodies predominantly co-localised with sEVd ≤ 100 nm but not with sEVd > 100 nm, demonstrating the CD63-CD81-enriched sEV and CD63-CD81-depleted sEV subpopulations. In summary, we demonstrate that nanoscopic profiling of surface exosome markers on sEVs using HS-AFM is feasible for characterising distinct sEV subpopulations in a heterogeneous sEV mixture.

Decreased Extracellular Vesicle Vasorin in Severe Preeclampsia Plasma Mediates Endothelial Dysfunction

BACKGROUND

Preeclampsia is a serious pregnancy complication affecting 5% to 8% of pregnancies globally. preeclampsia is a leading cause of maternal and neonatal morbidity and death. Despite its prevalence, the underlying mechanisms of preeclampsia remain unclear. This study investigated the role of vasorin in preeclampsia pathogenesis by examining its levels in extracellular vesicles (EVs) and effects on vascular function.

METHODS AND RESULTS

We conducted unbiased proteomics on urine-derived EVs from women with severe preeclampsia and normotensive pregnancies, identifying differentially abundant proteins. Vasorin expression levels were measured in urinary EVs, plasma EVs, and placental tissue. EVs were generated from human and murine placental explants. Vascular functions were assessed using murine aortic rings and human aortic endothelial cells. Vasorin expression was manipulated in human aortic endothelial cells via overexpression and knockdown followed by RNA sequencing. One hundred twenty proteins showed ≥±1.5-fold regulation (P<0.05) between severe preeclampsia and NTP. Vasorin levels decreased in severe preeclampsia in urinary EVs, plasma EVs, and placental tissue. Vasorin levels increased with gestational age in murine pregnancy and were diminished in a murine model of preeclampsia. Severe preeclampsia and murine preeclampsia EVs impaired human aortic endothelial cell migration and inhibited murine aortic ring vasorelaxation. Vasorin overexpression counteracted these effects. RNA sequencing showed that vasorin manipulation in human aortic endothelial cells differentially regulated hundreds of genes linked to vasculogenesis, proliferation, migration, and apoptosis.

CONCLUSIONS

The data suggest that vasorin, delivered to the endothelium via EVs, regulates vascular function and that the loss of EV vasorin may be one of the mechanistic drivers of preeclampsia.

Astrocyte-Derived Extracellular Vesicles Alleviate Optic Nerve Injury Through Remodeling of Retinal Microenvironmental Homeostasis

Purpose

Traumatic optic neuropathy (TON) leads to the loss of retinal ganglion cells (RGCs) and results in permanent visual impairment. Protecting and regenerating RGCs is crucial for the treatment of TON. Studies have demonstrated that astrocyte-derived extracellular vesicles (ADEVs) exhibit neuroprotective effects in models of central nervous system (CNS) injury. This study aimed to investigate whether ADEVs have a similar neuroprotective effect on RGCs in an optic nerve crush (ONC) rat model.

Methods

ADEVs were collected from primary rat astrocytes, and an ONC model was established to evaluate the effects of ADEVs on retinal structure and visual function using optical coherence tomography (OCT), hematoxylin and eosin (H&E) staining, and flash visual evoked potential (f-VEP) analysis. Immunofluorescence was used to examine RGCs and investigate reactive gliotic changes. Additionally, miRNA sequencing of ADEVs and retinal mRNA sequencing were performed to identify the potential mechanisms involved.

Results

ADEVs protected RGCs from progressive loss and improved visual function. ADEVs also significantly increased the expression of glial fibrillary acidic protein (GFAP) and modulated microglial activation. The miRNAs associated with ADEVs were targeted by neuroprotective signals, such as MAPK, PI3K-AKT, and TNF-α, and through the targeting network generated via retinal mRNA sequencing, we found that potential functional genes, such as THBS1, PAK3, and Gstm1, likely participate in microenvironmental regulation.

Conclusions

We discovered that ADEVs play a neuroprotective role in optic nerve injury. Our findings provide a new cell-free therapeutic strategy for optic neuropathy.

Characterizing extracellular vesicles of human fungal pathogens

Since their discovery in 2007, there has been growing awareness of the importance of fungal extracellular vesicles (EVs) for fungal physiology, host-pathogen interactions and virulence. Fungal EVs are nanostructures comprising bilayered membranes and molecules of various types that participate in several pathophysiological processes in fungal biology, including secretion, cellular communication, immunopathogenesis and drug resistance. However, many questions remain regarding the classification of EVs, their cellular origin, passage across the cell wall, experimental models for functional and compositional analyses, production in vitro and in vivo and biomarkers for EVs. Here, we discuss gaps in the literature of fungal EVs and identify key questions for the field. We present the history of fungal EV discovery, discuss five major unanswered questions in fungal EV biology and provide future perspectives for fungal EV research. We primarily focus our discussion on human fungal pathogens, but also extend it to include knowledge of other fungi, such as plant pathogens. With this Perspective we hope to stimulate new approaches and expand studies to understand the biology of fungal EVs.

Nerve growth factor precursor alterations in neuron-derived extracellular vesicles from individuals with Down syndrome along the Alzheimer's disease continuum

BACKGROUND

In Down syndrome (DS) and Alzheimer's disease (AD), nerve growth factor precursor protein (proNGF) accumulates in the brain. However, its non-invasive detection using neuron-derived extracellular vesicles (NDEVs) from plasma remains unexplored.

METHODS

We included 139 adults with DS (45 asymptomatic [aDS], 94 symptomatic for AD [sDS]) and 37 healthy controls. NDEVs were isolated from plasma. ProNGF and tetraspanin (CD81) were quantified by enzyme-linked immunosorbent assay. We assessed proNGF/CD81 changes with age, along the AD continuum (aDS and sDS), and associations with cerebrospinal fluid (CSF), plasma biomarkers, episodic memory, and basal forebrain volume.

RESULTS

In DS, proNGF/CD81 levels increased with age and were higher in NDEVs from asymptomatic and symptomatic individuals compared to controls, with the highest levels in the symptomatic group. ProNGF correlated with CSF phosphorylated tau (p-tau)181, plasma p-tau217, neurofilament light chain, and episodic memory.

DISCUSSION

ProNGF/CD81 levels in NDEVs increase along the AD continuum in DS and parallel tau pathology, indicating the potential as a promising biomarker for monitoring disease progression in plasma.

HIGHLIGHTS

Nerve growth factor precursor protein (ProNGF)/tetraspanin (CD81) ratio increased in the third decade of life, 20 years before Alzheimer's disease (AD) symptom onset in Down syndrome (DS). proNGF/CD81 concentrations were significantly higher in individuals with DS compared to controls and were notably elevated in individuals with DS and symptomatic AD compared to asymptomatic AD. proNGF/CD81 concentrations were associated with tau pathology and neuronal injury.

Unravelling exosome paradigm: Therapeutic, diagnostic and theranostics application and regulatory consideration

In the recent decade, extracellular vesicles (EVs) have been released from nearly all the kingdoms, modulating intercellular communication and maintaining the human body's homeostasis by regulating different cellular processes. Among EVs, exosomes are the emerging field in biopharmaceuticals. They have lipid bilayer ranging from 30 to 150 nm in size and encompass DNA, RNA, protein lipids, etc. Their sources are widespread, easy to acquire, and cost-effective in manufacturing. This review focuses on the detailed classification of exosomes existing in nature, knowledge and application of omics, therapeutic, diagnostic and theranostic application of exosomes. It covers diseases such as cancer, infectious diseases (viral, bacterial, fungal infections), neurodegenerative diseases, metabolic diseases, lifestyle diseases (diabetes, cardiovascular, gastric disorder (IBD)), autoimmune disorders and their biodistribution. This article unfolds the recent progress in the exosomes arena and covers all the regulatory considerations (FDA, EMA, and other nations) involved with it. Moreover, a detailed discussion about clinical trials and its manifestation with exosomes and challenges associated with their isolation procedures, reproducibility, and safety concerns.

Comprehensive Comparison of Extracellular Vesicles Derived from Mesenchymal Stem Cells Cultured with Fetal Bovine Serum and Human Platelet Lysate

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as a promising approach in regenerative therapy. However, the clinical application of MSC-EVs is hindered by the presence of xenogenic components, such as fetal bovine serum (FBS), which is the most used culture supplement for MSCs. Human platelet lysate (HPL) has been proposed as an alternative to FBS, but whether MSC-EVs derived from HPL-cultured MSCs are suitable for clinical translation remains unclear. In this study, we comprehensively compared the characterization of EVs derived from MSCs cultured in the medium with FBS (F-EVs) and HPL (H-EVs). Our study showed that HPL promoted MSC-EV production without compromising EVs critical quality attributes. Multiomics sequencing revealed the stability of H-EVs from different umbilical cord donors and global functional alterations for MSC-EVs under different culture conditions. In comparison to F-EVs, H-EVs enriched more angiogenesis-related molecules and exhibited enhanced angiogenesis, which were further confirmed by in vivo and in vitro studies. H-EVs significantly reduced renal microvascular rarefaction and promoted the regeneration of umbilical vein endothelial cells to hypoxia stimulation compared to that of F-EVs. In conclusion, our findings demonstrated that HPL as culture supplements did not alter the critical quality attributes of MSC-EVs, specifically holding a higher yield and quality of MSC-EVs with enhanced angiogenic potential.

Synovial Fluid-Derived Exosomes from Osteoarthritis Patients Modulate Cell Surface Phenotypes of Monocytes and Cytokine Secretions

BACKGROUND

Exosomes can be found in the synovial fluid of inflamed knee joints, which play a significant role in osteoarthritis (OA) progression. However, their role - in modulating the cellular environment within the body, particularly monocytes remain unexplored. This study aimed to evaluate the immunomodulatory effect of exosomes on monocytes.

METHODS

Exosomes were isolated by ultracentrifugation and characterized using nanoparticle tracking analysis (NTA), scanning electron microscopy (SEM), and Western blot. The effect of exosomes in modulating monocyte phenotypes as well as cytokine secretion were further assessed in a co-culture condition using flow cytometry and ELISA accordingly.

RESULTS

Exosomes were identified as spherical particles with a size distribution ranging from 30 nm to 150 nm. These nanoparticles intensely expressed exosome protein markers including CD9, CD63, CD81, and HSP70. The expression of HLA-DR, CD14, and CD11b on monocytes decreased in the presence of exosomes after 24 h of incubation, regardless of the dose. Exosomes significantly induced the release of anti-inflammatory cytokines IL-1Ra in a time- and dose-dependent manner, while TNF-α secretion remains unchanged regardless of the presence or absence of exosomes.

CONCLUSION

This study highlights the immunoregulatory role of exosomes on monocytes, emphasizing the need for further studies into the underlying mechanism.

Microvesicle Tissue Factor Procoagulant Activity Is Elevated and Correlated With Disease Severity in Patients With Cirrhosis

BACKGROUND AND AIMS

Tissue factor-expressing microvesicles (MV-TF) have been found to correlate with thrombotic complications in various diseases. Simultaneously, there is expanding research regarding the effect of the coagulation cascade on liver fibrosis progression. The aim of our manuscript was to evaluate MV-TF activity in patients with cirrhosis and its correlation with disease severity.

METHODS

We prospectively enrolled 82 patients [11 with cirrhosis and hepatocellular cancer (Group 1), 50 with cirrhosis (Group 2) and 21 controls (Group 3)]. Extensive workup for disease staging and exclusion criteria was undertaken. Exclusion criteria included thrombophilia, history of thrombosis, recent hospitalisation, ongoing infection, alcohol dependence, cancer, haematological diseases and use of anticoagulant, antiplatelet or contraceptive drugs. Plasma tissue factor antigen concentration and MV-TF activity were assessed.

RESULTS

MV-TF showed median values of 4.03 [1.57], 3.17 [1.59] and 2.26 [1.23] pg/mL in Groups 1, 2 and 3, respectively. There was a statistically significant difference between Groups 1 and 3 (p < 0.001) and Groups 2 and 3 (p = 0.003), while Group 1 had higher values than Group 2 without statistical significance (p = 0.088). In Group 2, the patients' Child-Pugh (CP) stage was A in 56%, B in 26% and C in 18% of cases. MV-TF activity significantly correlated with decompensated cirrhosis (p = 0.005) and higher CP stage (p = 0.011). Finally, MV-TF activity significantly correlated with 12-month mortality (p = 0.021).

CONCLUSIONS

MV-TF activity is elevated in patients with cirrhosis, showing a significant correlation with disease severity. MV-TF may play a role in the procoagulant imbalance of liver cirrhosis and their contribution in disease progression should be studied further.

Extracellular Vesicle-Associated miR-ERIA Exerts the Antiangiogenic Effect of Macrophages in Diabetic Wound Healing

ARTICLE HIGHLIGHTS

An understanding of cell interactions is needed to identify therapeutic targets for diabetic cutaneous ulcers. We explored extracellular vesicles after treatment with advanced glycation end products (AGEs-EVs) derived from macrophages that can suppress diabetic cutaneous wound healing. We found that a novel miRNA enriched in AGEs-EVs (miR-ERIA) suppresses the migration and tube formation of vascular endothelial cells by targeting helicase with zinc finger 2. miR-ERIA offers a potential therapeutic target for diabetic cutaneous ulcers.

Decoding the MMP14 integrin link: Key player in the secretome landscape

Rapid progress has been made in the exciting field of secretome research in health and disease. The tumor secretome, which is a significant proportion of the tumor proteome, is secreted into the extracellular space to promote intercellular communication and thus tumor progression. Among the many molecules of the secretome, integrins and matrix metalloproteinase 14 (MMP14) stand out as the interplay of adhesion and proteolysis drives invasion. Integrins serve as mechanosensors that mediate the contact of cells with the scaffold of the extracellular matrix and are significantly involved in the precise positioning and activity control of the membrane-bound collagenase MMP14. As a secretome proteinase, MMP14 influences and modifies the secretome itself. While integrins and MT-MMPs are membrane bound, but can be released and are therefore border crossers between the cell surface and the secretome, the extracellular matrix is not constitutively cell-bound, but its binding to integrins and other cell receptors is a stringently regulated process. To understand the mutual interactions in detail, we first summarize the structure and function of MMP14 and how it is regulated at the enzymatic and cellular level. In particular, the mutual interactions between integrins and MMP14 include the proteolytic cleavage of integrins themselves by MMP14. We then review the biochemical, cell biological and physiological effects of MMP14 on the composition and associated functions in the tumor secretome when either bound to the cell membrane, or located on extracellular microvesicles, or as a proteolytically shed non-membrane-bound ectodomain. Novel methods of proteomics, including the analysis of extravesicular vesicles, and new methods for the quantification of MMP14 will provide new research and diagnostic tools. The proteolytic modification of the tumor secretome, especially by MMP14, may bring an additional aspect to tumor secretome studies and will have an impact on the diagnosis and most likely also on the therapy of cancer patients.

Transcriptome Analysis of HNSCC by Aggregatibacter actinomycetemcomitans Extracellular Vesicles

OBJECTIVES

The role of extracellular vesicles (EVs), also known as outer membrane vesicles (OMVs), secreted by oral bacteria in the progression of head and neck squamous cell carcinomas (HNSCCs), is largely unexplored. This study aimed to investigate the influence of bacterial EVs, specifically those derived from Aggregatibacter actinomycetemcomitans (Aa), on the progression of HNSCC.

MATERIALS AND METHODS

FaDu and UMSCC1 cell lines were treated with Aa-derived EVs, and oncogenic activities were assessed. Comprehensive cellular and RNA-sequencing transcriptome analyses were conducted to assess the impact of these EVs on cell cycle progression and gene expression.

RESULTS

Our findings reveal that Aa-derived EVs accelerate cell cycle progression through the S and G2 phases and enhance invasion in HNSCC cell lines. RNA-sequencing analysis showed that Aa-derived EVs exert a more significant effect on general transcript expression than on microRNA profiles, except for miR-146a, which is recognized as a key factor in both carcinogenesis and immune modulation.

CONCLUSIONS

Bacterial EVs, particularly from periodontal pathogens like Aa, are significant modulators within the oral cancer environment, potentially affecting cellular behavior and gene expression profiles. This study highlights the complex relationship between periodontal health and oral carcinogenesis, emphasizing the significant role of bacterial EVs in HNSCC progression.

Metabolic Reprogramming Into a Glycolysis Phenotype Induced by Extracellular Vesicles Derived From Prostate Cancer Cells

Most cancer cells adopt a less efficient metabolic process of aerobic glycolysis with high level of glucose uptake followed by lactic acid production, known as the Warburg effect. This phenotypic transition enables cancer cells to achieve increased cellular survival and proliferation in a harsh low-oxygen tumor microenvironment. Also, the resulting acidic microenvironment causes inactivation of the immune system such as T-cell impairment that favors escape by immune surveillance. While lots of studies have revealed that tumor-derived EVs can deliver parental materials to adjacent cells and contribute to oncogenic reprogramming, their functionality in energy metabolism is not well addressed. In this study, we established prostate cancer cells PC-3AcT resistant to cellular death in an acidic culture medium driven by lactic acid. Quantitative proteomics between EVs derived from PC-3 and PC-3AcT cells identified 935 confident EV proteins. According to cellular adaptation to lactic acidosis, we revealed 159 regulated EV proteins related to energy metabolism, cellular shape, and extracellular matrix. These EVs contained a high abundance of glycolytic enzymes. In particular, PC-3AcT EVs were enriched with apolipoproteins including apolipoprotein B-100 (APOB). APOB on PC-3AcT EVs could facilitate their endocytic uptake depending on low density lipoprotein receptor of recipient PC-3 cells, encouraging increases of cellular proliferation and survival in acidic culture media via increased activity and expression of hexokinases and phosphofructokinase. The activation of recipient PC-3 cells can increase glucose consumption and ATP generation, representing an acquired metabolic reprogramming into the Warburg phenotype. Our study first revealed that EVs derived from prostate cancer cells could contribute to energy metabolic reprogramming and that the acquired metabolic phenotypic transition of recipient cells could favor cellular survival in tumor microenvironment.

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 Derived from Mesenchymal Stromal Cells Reduce Pseudomonas aeruginosa Lung Infection and Inflammation in Mice

The World Health Organization and the U.S. Centers for Disease Control and Prevention have reported that antibiotic resistant infections with Pseudomonas aeruginosa present a significant health risk world-wide. In the genetic disease Cystic Fibrosis (CF), chronic antibiotic resistant Pseudomonas lung infections and persistent inflammation remain the leading causes of morbidity and mortality. While highly effective modulator therapy (HEMT) dramatically improves lung function in CF, they fail to eradicate chronic infections or eliminate the associated hyperinflammatory state. Thus, there is an urgent need for innovative therapies that can simultaneously eliminate antibiotic resistant P. aeruginosa lung infection and the attendant hyperinflammatory lung environment. Mesenchymal stromal cell-derived extracellular vesicles (MSC EVs) represent a promising solution, offering potent anti-inflammatory, immunomodulatory, and antimicrobial properties while being safe and non-toxic. This study demonstrates using a CF mouse model of infection that MSC EVs reduce acute P. aeruginosa lung infection and inflammation. MSC EVs reduced Pseudomonas burden, immune cell infiltration, and pro-inflammatory cytokine levels. As the first investigation of MSC EVs in CF, this research underscores the dual effects of MSC EVs; mitigating inflammation and reducing bacterial burden. These findings mark an important advancement in antimicrobial therapy, addressing the unmet need for reducing antibiotic resistant infections and hyperinflammation for people with CF as well as the multitude of others with chronic, antibiotic resistant P. aeruginosa lung infections.

GRAPHICAL ABSTRACT

NEW AND NOTEWORTHY

This is the first study demonstrating the ability of Mesenchymal Stromal Cell Extracellular Vesicles (MSC EVs) to reduce Pseudomonas aeruginosa burden and inflammation in a CF mouse model of infection.

Synovial Fibroblast Extracellular Vesicles Induce Inflammation via Delivering miR-21-5p in Osteoarthritis

Small extracellular vesicles (sEVs) derived from different osteoarthritic (OA) tissues regulate OA-related biological processes through transporting their content (proteins, miRNAs, etc.) to recipient cells. This study aimed to characterize the miRNA profile of synovial fibroblasts-derived small EVs (FS_OA_sEVs) and investigate their role in inflammation in chondrocytes. Chondrocytes were isolated from macroscopically preserved and lesioned OA cartilage (C_OAmin and C_OAmax) and synovial fibroblasts from OA synovium. Synovial fibroblasts-derived small EVs (FS_OA_sEVs) were characterized according to ISEV guidelines and used for miRNA profiling and bioinformatics analysis. miR-21-5p was identified as one of the most abundant, and its target genes, such as KLF6, were enriched in OA-related processes including inflammation. Treatment of C_OAmin chondrocytes with FS_OA_sEVs resulted in decreased expression of COL2A1 and ACAN and an increase in catabolic markers MMP-3 and MMP-13. Moreover, C-OAmin receiving FS_OA_sEVs exhibited increased levels of inflammatory markers and miR-21-5p expression, resembling chondrocytes' phenotype from lesioned OA cartilage, whereas miR-21-5p inhibition reversed their expression of inflammatory markers and miR-21-5p. Compared to C_OA min, C_OAmax chondrocytes exhibited increased miR-21-5p and inflammatory markers expression and decreased KLF6 expression. miR-21-5p inhibition in C_OAmax led to KLF6 upregulation and suppression of inflammatory mediators, whereas co-treatment with siRNA against KLF6 negated this effect, confirming a potential direct regulatory relationship between miR-21-5p and KLF6. Our results provide novel insights into the FS_OA_sEV-mediated inflammation axis, highlighting FS_OA_sEV-derived miR-21-5p as a driver of OA progression via regulating inflammation in chondrocytes.

Exploring the relationship between extracellular vesicles, the dendritic cell immunoreceptor, and microRNA-155 in an in vivo model of HIV-1 infection to understand the disease and develop new treatments

HIV-1 infection induces persistent immune system activation despite antiretroviral therapy. New immunomodulatory targets might be required to restore immune competence. The dendritic cells immunoreceptor (DCIR) can bind HIV-1 and regulate immune functions and extracellular vesicles (EVs) production. EVs have emerged as biomarkers and a non-invasive tool to monitor HIV-1 progression. In people living with HIV-1, an increase in the size and abundance of EVs is associated with a decline in the CD4/CD8 T cells ratio, a key marker of immune dysfunction. Analysis of host nucleic acids within EVs has revealed an enrichment of microRNA-155 (miR-155) during HIV-1 infection. Experiments have demonstrated that miR-155-rich EVs enhance HIV-1 infection in vitro. A humanized NSG-mouse model was established to assess the in vivo impact of miR-155-rich EVs. Co-production of the virus with miR-155-rich EVs heightened the viral load and lowered the CD4/CD8 ratio in the mice. Upon euthanasia, EVs were isolated from plasma for size and quantity assessment. Consistent with findings in individuals with HIV-1, increased EV size and abundance were inversely correlated with the CD4/CD8 ratio. Next, by using the virus co-product with EV-miR-155, we tested a DCIR inhibitor to limit infection and immune damage in a humanized mouse model. DCIR inhibition reduced infection and partially restored immune functions. Finally, viral particles and various EV subtypes can convey HIV-1 RNA. HIV-1 RNA was predominantly associated with large EVs (200-1000 nm) rather than small EVs (50-200 nm). Viral loads in large EVs strongly correlated with blood and tissue markers of immune activation. The humanized mice model has proven its applicability to studying the roles of EVs on HIV-1 infection and investigating the impact of DCIR inhibition.

Identification of DYRK1b as a novel regulator of small extracellular vesicle release using a high throughput nanoscale flow cytometry screening platform

Extracellular vesicles (EVs) are important mediators of intercellular communication and have various roles in physiological and pathological processes. Discovery of regulators of EV biogenesis and release has led to significant improvements in our understanding of EV biology and has highlighted disease-specific pathways. Large scale discovery studies of EV regulators are limited by conventional methods of EV analysis with limited throughput and sensitivity. To address this, this study presents a high-throughput flow cytometry-based platform for the quantification of EVs released from cells. Here, a system was developed using the MDA-MB-231 cell line stably expressing ZsGreen, which passively loads ZsGreen proteins into EVs, and nanoscale flow cytometry. EV detection and quantitation was optimized and validated for a 96-well format. The high-throughput flow cytometry screening platform quantified the effect of 156 kinase inhibitors on EV number and identified AZ191 - a DYRK1b inhibitor - as a potent EV inhibitor. DYRK1b inhibition and knockdown confirmed a significant reduction in total EV number, with small EVs demonstrating the largest reduction. DYRK1b knockdown altered the intracellular distribution of EV marker CD63, suggesting a role for DYRK1b in EV trafficking. In conclusion, our study establishes a platform for high-throughput analysis of EV dynamics and introduces DYRK1b kinase as a novel EV-regulator.

Youthful Brain-Derived Extracellular Vesicle-Loaded GelMA Hydrogel Promotes Scarless Wound Healing in Aged Skin by Modulating Senescence and Mitochondrial Function

Slow wound healing in the elderly has attracted much attention recently due to the associated infection risks and decreased longevity. The "brain-skin axis" theory suggests that abnormalities in the brain and nervous system can lead to skin degeneration because abnormal mental states, like chronic stress, can have negative physiological and functional effects on the skin through a variety of processes, resulting in delayed wound healing and accelerated skin aging. However, it remains unclear whether maintaining a youthful brain has beneficial effects on aged skin healing. In light of this, we identified youthful brain-derived extracellular vesicles (YBEVs) and created a composite GelMA hydrogel material that encourages scarless wound healing in aged skin. We found that YBEVs reduce the expression of senescence, senescence-associated secretory phenotypes, and inflammation-associated proteins, and even restore dysfunction in senescent cells. Furthermore, by encouraging collagen deposition, angiogenesis, epidermal and dermal regeneration, and folliculogenesis, we demonstrated that YBEV-containing composite hydrogels accelerated scarless wound healing in skin wounds of aged rats. The pro-repairing speed and effect of this composite hydrogel even matched that of young rats. Subsequent proteomic analysis revealed the presence of numerous proteins within YBEVs, some of which may play a role in the regulation of skin energy intake, particularly through oxidative phosphorylation and mitochondrial function. In conclusion, the findings suggest that maintaining a youthful brain could potentially alleviate skin aging, and the proposed YBEVs-GelMA hydrogel emerges as a promising strategy for addressing age-related impairments in skin healing.

Engineering Exosomes for CNS Disorders: Advances, Challenges, and Therapeutic Potential

The development of targeted drugs for diseases of the central nervous system (CNS) is a significant challenge due to the structural complexity and functional specificities of these systems. Recently, exosomes have emerged as a promising therapeutic platform, given their unique capacity to traverse the blood-brain barrier and deliver bioactive molecules to target cells. This review examines recent advances in exosome research with a particular focus on CNS diseases, emphasizing their role as carriers of therapeutic cargo, including proteins, RNAs, and lipids. Nevertheless, significant challenges remain before exosome-based therapies can be translated from preclinical research to clinical applications. These include the need for scalable production and standardized isolation methods. Despite these hurdles, ongoing studies continue to shed light on the mechanisms of exosome-mediated neuroprotection and neurodegeneration. This paves the way for innovative therapeutic strategies to address CNS disorders.

Oxidative Stress, Gut Microbiota, and Extracellular Vesicles: Interconnected Pathways and Therapeutic Potentials

Oxidative stress (OS) and gut microbiota are crucial factors influencing human health, each playing a significant role in the development and progression of chronic diseases. This review provides a comprehensive analysis of the complex interplay between these two factors, focusing on how an imbalance between reactive oxygen species (ROS) and antioxidants leads to OS, disrupting cellular homeostasis and contributing to a range of conditions, including metabolic disorders, cardiovascular diseases, neurological diseases, and cancer. The gut microbiota, a diverse community of microorganisms residing in the gastrointestinal tract, is essential for regulating immune responses, metabolic pathways, and overall health. Dysbiosis, an imbalance in the gut microbiota composition, is closely associated with chronic inflammation, metabolic dysfunction, and various diseases. This review highlights how the gut microbiota influences and is influenced by OS, complicating the pathophysiology of many conditions. Furthermore, emerging evidence has identified extracellular vesicles (EVs) as critical facilitators of cellular crosstalk between the OS and gut microbiota. EVs also play a crucial role in signaling between the gut microbiota and host tissues, modulating immune responses, inflammation, and metabolic processes. The signaling function of EVs holds promise for the development of targeted therapies aimed at restoring microbial balance and mitigating OS. Personalized therapeutic approaches, including probiotics, antioxidants, and fecal microbiota transplantation-based strategies, can be used to address OS-related diseases and improve health outcomes. Nonetheless, further research is needed to study the molecular mechanisms underlying these interactions and the potential of innovative interventions to offer novel strategies for managing OS-related diseases and enhancing overall human health.

Rotenone induced acute miRNA alterations in extracellular vesicles produce mitochondrial dysfunction and cell death

How extracellular vesicles (EVs) may contribute to mechanisms of primary intracellular pathogenesis in Parkinson's disease (PD) remains unknown. To critically advance our understanding of how EVs influence early-stage PD pathogenesis, we tested the hypothesis that rats acutely exposed to the PD neurotoxin rotenone would produce differential miRNAs in CSF/serum-derived EVs and that such modulation would be responsible for PD-relevant functional alterations in recipient neuronal cells. We discovered that acute rotenone treatment produced significant and specific serum miRNA alterations. Primary midbrain neurons treated with serum EVs from rotenone-exposed rats produced oxidative stress, mitochondrial toxicity, and cell loss in neuronal culture. These mechanisms were dependent on miR-30a-5p and miR-484. Thus, this study has elucidated that differential expression of miRNAs in circulating EVs from serum/CSF of rats is a potential early diagnostic marker for PD, and that the modulation of cellular functions and viability due to extracellular vesicles determines the pathological fate.

Potential upscaling protocol establishment and wound healing bioactivity screening of exosomes isolated from canine adipose-derived mesenchymal stem cells

Mesenchymal stem cell-derived exosomes exhibit promising potential in tissue regeneration. Recent studies highlight its significant therapeutic potential in various stages of wound healing. However, the clinical translation of exosome-based therapy was hindered due to issues regarding low productivity and the lack of efficient production protocol to obtain a clinically relevant exosome quantity. Therefore, this study established a potential upscaling protocol to produce exosomes derived from canine adipose-derived mesenchymal stem cells (cAD-MSCs) and explored its potential for wound treatment. The potential upscaling protocol, termed VSCBIC-3-3D, was carried out using VSCBIC-3 in-house serum-free exosome-collecting solution in a three-dimensional (3D) culture system followed by the tangential flow filtration (TFF) isolation. Our findings suggest that culturing cAD-MSCs with VSCBIC-3 maintained cell morphology and viability. Compared to conventional two-dimensional (2D) protocols, The potential upscaling protocol increased exosome yield and concentration in conditioned medium by 2.4-fold and 3.2-fold, respectively. The quality assessment revealed enhanced purity and bioactivity of exosomes produced using the VSCBIC-3-3D protocol. In addition, the cAD-MSCs-derived exosomes were shown to significantly improve fibroblast migration, proliferation, and wound healing-related gene expression in vitro. This study collectively demonstrates that potential upscaling protocol establishment allowed robust production of exosomes from cAD-MSCs, which exhibit therapeutic potential for wound healing in vitro.

Exploring the Interaction of Tumor-Derived Exosomes and Mesenchymal Stem Cells in Tumor Biology

Exosomes are actively produced extracellular vesicles, released from different cell types, that exert important regulatory roles in vital cellular functions. Tumor-derived exosomes (TDEs) have received increasing attention because they enable intercellular communication between the neoplastic and non-neoplastic cells present in the microenvironment of tumors, affecting important functions of different types of mesenchymal stem cells (MSCs) with the ability to self-renew and differentiate. MSC-derived exosomes (MSC-exos) carry a variety of bioactive molecules that can interact with specific cellular targets and signaling pathways, influencing critical processes in tumor biology, and exhibiting properties that either promote or inhibit tumor progression. They can regulate the tumor microenvironment by modulating immune responses, enhancing or suppressing angiogenesis, and facilitating tumor cells' communication with distant sites, thus altering the behavior of non-cancerous cells present in the microenvironment. Herein, we explore the main functions of TDEs and their intricate interactions with MSC-exos, in terms of enhancing cancer progression, as well as their promising clinical applications as tumor microenvironment modulators.

Identification of Potential Amblyomma americanum Antigens After Vaccination with Tick Extracellular Vesicles in White-Tailed Deer

BACKGROUND/OBJECTIVE

Anti-tick vaccines represent a promising alternative to chemical acaricides for the management of ticks on wildlife; however, little progress has been made to produce a vaccine effective in wild hosts that are critical for tick reproduction, such as the white-tailed deer (Odocoileus virginianus). We recently tested Amblyomma americanum salivary and midgut extracellular vesicles as vaccine candidates in white-tailed deer, which resulted in on-host female tick mortality. The objective of this study was to identify the proteins recognized by the antibodies regenerated during these vaccinations to determine potential antigens for vaccine development for white-tailed deer.

METHODS

Using a proteomic approach, we characterized the cargo within salivary and midgut vesicles. Label-free quantitative proteomics were used to investigate significant changes in protein loading within extracellular vesicles in these two organs. The pre-vaccination and post-vaccination serum from three animals vaccinated with salivary and midgut vesicles and one control animal were used to identify proteins recognized by circulating antibodies.

RESULTS

We show that these salivary and midgut vesicles contain a "core-cargo" enriched in chaperones, small GTPases, and other proteins previously reported in small EVs. Label-free quantitative proteomics show significant differences in protein cargo between salivary and midgut vesicles (333 proteins out of 516). Proteomic analysis of immunoprecipitated proteins identified thirty antigens with potential for use in anti-tick vaccines, seven of which we have categorized as high priority.

CONCLUSIONS

Proteins within tick salivary and midgut vesicles are recognized by antibodies from vaccinated white-tailed deer. These proteins can be further evaluated for their function and potential as vaccine candidates against ticks.

Analysis of extracellular vesicles of frequently used colorectal cancer cell lines

Colorectal cancer (CRC) ranks as the second most prevalent malignancy globally, highlighting the urgent need for more effective diagnostic and therapeutic strategies, as well as a deeper understanding of its molecular basis. Extensive research has demonstrated that cells actively secrete extracellular vesicles (EVs) to mediate intercellular communication at both proximal and distal sites. In this study, we conducted a comprehensive analysis of the RNA content of small extracellular vesicles (sEVs) secreted into the culture media of five frequently utilised CRC cell lines (RKO, HCT116, HCT15, HT29, and DLD1). RNA sequencing data revealed significant insights into the RNA profiles of these sEVs, identifying nine protein-coding genes and fourteen long non-coding RNA (lncRNA) genes that consistently ranked among the top 30 most abundant across all cell lines. Notably, the genes found in sEVs were highly similar among the cell lines, indicating a conserved molecular signature. Several of these genes have been previously documented in the context of cancer biology, while others represent novel discoveries. These findings provide valuable insights into the molecular cargo of sEVs in CRC, potentially unveiling novel biomarkers and therapeutic targets.

Extracellular vesicles: a new frontier in diagnosing and treating graft-versus-host disease after allogeneic hematopoietic cell transplantation

Graft-versus-host disease (GvHD) is a prevalent complication following allogeneic hematopoietic stem cell transplantation (HSCT) and is characterized by relatively high morbidity and mortality rates. GvHD can result in extensive systemic damage in patients following allogeneic HSCT (allo-HSCT), with the skin, gastrointestinal tract, and liver frequently being the primary target organs affected. The severe manifestations of acute intestinal GvHD often indicate a poor prognosis for patients after allo-HSCT. Endoscopy and histopathological evaluation remain employed to diagnose GvHD, and auxiliary examinations exclude differential diagnoses. Currently, reliable serum biomarkers for the diagnosis and differential diagnosis of GvHD are scarce. As an essential part of standard transplant protocols, early application of immunosuppressive drugs effectively prevents GvHD. Among them, steroids represent first-line therapeutic agents, and the JAK2 inhibitor ruxolitinib represents the second-line therapeutic agent. Currently, no efficacious treatment modality exists for steroid-resistant aGvHD. Therefore, the diagnosis and treatment of GvHD still face significant medical demands. Extracellular vesicles (EVs) are nanometer to micrometer-scale biomembrane vesicles containing various bioactive components, such as proteins, nucleotides, and metabolites. Distinctive changes in serum-derived EV components occur in patients after allo-HSCT; Hence, EVs are expected to be potential biomarkers for diagnosing and treating GvHD. Furthermore, cell-free therapeutics characterized by EVs derived from mesenchymal stem cells (MSCs) have manifested remarkable therapeutic efficacy in preclinical models and preclinical trials of GvHD. Customized engineered EVs with fewer toxic and side effects for the combined treatment of GvHD hold broad prospects for clinical translation. This review article examines the potential value of translating EVs into clinical applications for the diagnosis and treatment of GvHD. It summarizes the latest advancements and prospects of engineered EVs applying GvHD.

Influence of hemolysis, lipemia and bilirubin on biobank sample quality- origin and interference in the use for extracellular vesicle (EV) and MiRNA analyses

PURPOSE

Pre-analytic interferences can influence the laboratory downstream measurements. We recognized hemolysis, lipemia and bilirubin in some of the serum/plasma samples of the NTF-Biobank from polytraumatized patients. Aim of the present study was to detect interferences, find reasons and describe the influence on downstream analyses.

METHODS

The study included serum samples of n = 88 polytraumatized patients admitted to a Level 1 Trauma Center in Germany at the ER & up to 10 days after trauma. Optical absorption spectra of UV-VIS (350-660 nm) were measured to detect hemolysis, lipemia and bilirubin. To find reasons for the interferences, clinical parameters like triglycerides (TAGs), nutrition, anaesthesia or transfusions were collected from patients' record. Extracellular vesicles (EVs) were isolated by SEC from controls, lipidemic and hemolytic samples and analysed via NTA.

RESULTS

Within 10 days after trauma 31.8% of polytraumatized patients' samples showed hemolysis, 12.5% showed increased bilirubin and 15.9% lipemia. Hemolysis occurred in samples mostly at the ER (18%) and was not associated with the number of red blood cell transfusions or the ISS. Both contaminants, hemolysis and lipemia interfered with EV/EV-miRNA measurements. EV miR-16-5p was significantly increased in patients with hemolysis. The presence of lipids further influenced the EV particle size distribution and concentration.

CONCLUSION

The optical absorption spectra measurement is an easy tool for a robust pre-analytic sample controlling for the presence of interferences. Nutrition and anaesthesia were found to be related with lipemia in samples. Hemolysis and lipemia interfered with EV/EV-miRNA analysis. Therefore, the optical absorption spectra pre-analyses should be incorporated in the EV-biobank sampling.

Therapeutic Potential of Extracellular Vesicles in Oral Inflammation

The therapeutic potential of extracellular vesicles (EVs) in reducing oral inflammation is thoroughly examined in this review, with an emphasis on gingivitis, periodontitis, and oral mucositis. It explains the complex relationship between microbial dysbiosis and host immune responses in the aetiology of oral inflammation. Pathophysiological mechanisms of periodontitis are examined, emphasising the roles played by periodontal pathogens and inflammatory mediators in the disease's chronic course and systemic effects. Preclinical research is providing new evidence that EVs originating from various cellular sources control immune cell dynamics towards a pro-healing phenotype, promote tissue regeneration, and have immunomodulatory qualities. EV-based therapies appear to be a promising new therapeutic technique with potential benefits over traditional methods for the treatment of oral inflammatory illnesses by specifically altering inflammatory signalling pathways. This review highlights the potential of EVs to improve patient outcomes in oral health and emphasises the need for additional clinical research to clarify the therapeutic efficacy and underlying mechanisms of EVs in periodontal therapy.

Identification of Released Bacterial Extracellular Vesicles Containing Lpp20 from Helicobacter pylori

Helicobacter pylori is a pathogenic bacterium that causes gastric and extragastric diseases. We have previously demonstrated that one of the mechanisms of H. pylori-associated chronic immune thrombocytopenia involves immune complexes of platelets, a H. pylori protein Lpp20 and an anti-Lpp20 antibody. However, it remains unclear how Lpp20 enters the body. We hypothesize that bacterial extracellular vesicles (bEVs) transport Lpp20. Thus, this study assessed Lpp20 in the bEVs released from seven clinical H. pylori isolates, using immunoprecipitation (IP), immunoblotting (IB), and surface plasmon resonance imaging (SPRi), with anti-GroEL (a marker of bEVs) and anti-Lpp20 antibodies. Lpp20 and bEVs were each detected in lysates of all seven strains. IP-IB experiments demonstrated that bEVs containing Lpp20 were produced by five of the strains (J99, SS1, HPK5, JSHR3, and JSHR31). SPRi using an anti-Lpp20 antibody demonstrated significantly higher reflectance from the strain HPK5 than from its lpp20-disrupted strains (p < 0.01), indicating localization of Lpp20 on the bEVs' surface; Lpp20 may also be contained within bEVs. The bEVs containing Lpp20 were not detected from two clinical H. pylori strains (26695 and JSHR6) or from two lpp20-disrupted strains (26695ΔLpp20 and HPK5ΔLpp20). Differences in Lpp20 detection in bEVs are likely due to variations in bEV production resulting from strain diversity.

Evaluation of cognitive and mobility function in geriatric dogs following treatment with stem cell and stem cell extracellular vesicles derived from embryonic stem cells: a pilot study

Introduction

Declining physical or mental health in older dogs can lead to changes in the dog's cognitive and musculoskeletal function. Regrettably, these degenerative changes cannot be remedied. In the present study, geriatric small dogs exhibiting cognitive and behavioral changes were treated with human embryonic stem cell-derived mesenchymal stemcells (ES-MSCs, n = 21) and mesenchymal stem cell-derived extracellular vesicles (ES-MSC-EVs, n = 21).

Methods

Before and 2 weeks after treatment, the cognitive and mobility status of the dogs were assessed using theCanine Cognitive Dysfunction Rating (CCDR) and the Liverpool Osteoarthritis in Dogs (LOAD) scale. Additionally, safety assessments were conducted through blood tests such as complete blood count and serum chemistry.

Results

Following an assessment of clinical symptoms and blood tests in both the groups receiving ES-MSC and ES-MSC-EVs treatments, no notable side effects were detected. Moreover, the questionnaire survey revealed that both groups showed alleviation in CCDR and LOAD scores following administration.

Discussion

These findings suggest that ES-MSC and ES-MSC-EV treatments have the potential to be used as a therapeutic option for improving clinical symptoms of degenerative diseases such as canine cognitive dysfunction and degenerativemusculoskeletal diseases in elderly dogs.

Exosomes: an innovative therapeutic target for cerebral ischemia-reperfusion injury

Ischemic stroke is caused by artery stenosis or occlusion, which reduces blood flow and may cause brain damage. Treatment includes restoring blood supply; however, ischemia-reperfusion can still aggravate tissue injury. Reperfusion injury can increase levels of reactive oxygen species, exacerbate mitochondrial dysfunction, create excessive autophagy and ferroptosis, and cause inflammation during microglial infiltration. Cerebral ischemia-reperfusion injury (CIRI) is a key challenge in the treatment of ischemic stroke. Currently, thrombolysis (e.g., rt-PA therapy) and mechanical thrombectomy are the primary treatments, but their application is restricted by narrow therapeutic windows (<4.5 h) and risks of hemorrhagic complications. Exosomes reduce CIRI by regulating oxidative stress, mitochondrial autophagy, inflammatory responses, and glial cell polarization. In addition, their noncellular characteristics provide a safer alternative to stem cell therapy. This article reviews the research progress of exosomes in CIRI in recent years.

Mechanisms Tackling Salivary Gland Diseases with Extracellular Vesicle Therapies

Extracellular vesicles (EVs) are lipid-enclosed particles released from cells, containing lipids, DNA, RNA, metabolites, and cytosolic and cell surface proteins. EVs support intercellular communication and orchestrate organogenesis by transferring bioactive molecules in between cells. Mesenchymal stem cells are known to produce EVs, which exhibit immunomodulatory and regenerative capabilities in many target organs, including the salivary glands (SGs). Since cell-based therapies still pose challenges (e.g., donor variability, limited hemocompatibility, and safety), specific EVs may constitute a therapeutic alternative for SG diseases. New EV guidelines (MISEV2023) have recently been updated and reported by our consortium to consolidate the principles of EV biology and expand the boundaries toward innovative therapies. These guidelines provide valuable guidance for researchers to consistently assess the effectiveness of mesenchymal stem cell-derived EV cargo cues, such as microRNA, proteins, and other molecules, to target SG diseases. This review provides a narrative synthesis of preclinical studies on EVs by highlighting EV mechanisms and their potential therapeutic applications for SG diseases, such as radiotherapy-induced SG hypofunction and Sjögren's syndrome, as well as inflammatory and aging-related SG conditions. Additionally, we highlight key areas of the MISEV2023 guidelines that will support future EV-based therapies in SG research. This review adhered to PRESS guidelines (Peer Review of Electronic Search Strategies) and utilized established databases, including Medline/PubMed, Embase, Web of Science, and Scopus, alongside machine learning tools for sorting the most impactful EV studies for SG diseases.

Microfluidic loading of verteporfin into extracellular vesicles for neuroblastoma therapy

Despite contributing to cancer progression, extracellular vesicles (EVs) could serve as potential drug delivery systems in cancer treatment, having the ability to dissolve water-insoluble drugs and facilitate targeted delivery. However, the clinical translation of EVs is still in its infancy. While traditional methods for EV modifications will remain relevant, microfluidic approaches are expected to replace benchtop methods. Taking advantage of lab-on-chip devices, passive cargo loading through microfluidic mixing and incubation may be an important strategy to produce functional engineered EVs. This study focuses on developing a microfluidic device to generate EVs loaded with verteporfin (VP), a hydrophobic porphyrin with potential applications in neuroblastoma (NB) therapy, aiming to enhance its therapeutic effectiveness. The platform ensures perfect mixing and tunable incubation time for mesenchymal stem cell-derived EVs and VP, demonstrating a significantly higher loading efficiency than traditional methods, while operating under gentle conditions that preserve EV integrity and functionality, unlike other microfluidic techniques that involve harsh mechanical or chemical treatments. The VP-loaded EVs (VP-EVs) can then be easily recovered, making them available for subsequent analysis and use. MTT assay confirmed that VP-EVs are more efficient than free VP in reducing the viability of a NB cell line. Finally, immunofluorescence assay and western blot demonstrated a greater reduction in YAP expression after treatment with VP-EVs in an NB cell line when compared to free VP. Being both non-destructive and straightforward, this microfluidic loading technique facilitates its adaptability to a wide spectrum of therapeutic compounds. As a versatile tool, microfluidic technology will help to fully unlock the potential of EVs for speeding up precision medicine and disease treatment.

Acoustofluidic Chromatography for Extracellular Vesicle Enrichment from 4 μL Blood Plasma Samples

We present a novel acoustofluidic chromatography platform for high-throughput nanoparticle trapping and enrichment, with a focus on extracellular vesicles (EVs) from blood plasma. The system features a packed bed of polystyrene beads inside a rectangular glass capillary, acoustically actuated by a piezoelectric element. Using fluorescent polystyrene nanoparticles as small as 25 nm, we characterized device performance across a frequency range of 0.45-4 MHz, demonstrating particle trapping at all tested frequencies. The platform achieved recoveries of up to 42.9 ± 3.2% at input powers as low as 55 mW and operated at high flow rates of up to 200 μL/min. Trapping capacity reached 6.7 × 109 ± 2.5 × 109 particles for 25 nm polystyrene beads. For EV isolation, processing just 4 μL of blood plasma yielded 2 × 108 washed EV-sized particles eluted in 100 μL within 8 min. Micro BCA analysis confirmed a plasma protein background below 2 μg/mL, enabling downstream mass spectrometry. This platform provides an efficient, high-throughput approach for nanoparticle trapping and EV enrichment with minimal sample volumes, offering potential applications in diagnostics and therapeutic development. Future work will focus on optimizing bead properties for EV subpopulation separation and scaling the system for clinical applications.

Mapping Organism-wide Single Cell mRNA Expression Linked to Extracellular Vesicle Biogenesis, Secretion, and Cargo

Extracellular vesicles (EVs) are functional lipid-bound nanoparticles trafficked between cells and found in every biofluid. It is widely claimed that EVs can be secreted by every cell, but the quantity and composition of these EVs can differ greatly among cell types and tissues. Defining this heterogeneity has broad implications for EV-based communication in health and disease. Recent discoveries have linked single-cell EV secretion to the expression of genes encoding EV machinery and cargo. To gain insight at single-cell resolution across an entire organism, we compared the abundance, variance, and co-expression of 67 genes involved in EV biogenesis and secretion, or carried as cargo, across >44 000 cells obtained from 117 cell populations in the Tabula Muris. Our analysis provides both novel holistic and cell population-specific insight into EV biology. The highest overall expression of EV genes occurs in secretory cells of the pancreas and perhaps more surprisingly, multiple non-neuronal cell populations of the brain. We find that the most abundant EV genes encode the most abundant EV cargo proteins (tetraspanins and syndecans), but these genes are highly differentially expressed across functionally distinct cell populations. Expression variance identifies dynamic and constitutively expressed EV genes while co-expression analysis reveals novel insights into cell population-specific coordination of expression. Results of our analysis illustrate the diverse transcriptional regulation of EV genes which could be useful for predicting how individual cell populations might communicate via EVs to influence health and disease.

Mesenchymal stem cells-derived small extracellular vesicles and apoptotic extracellular vesicles for wound healing and skin regeneration: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Studies examining the therapeutic potential of Mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) in wound healing and skin regeneration have progressed rapidly. Prior to considering clinical translation, a systematic and comprehensive understanding of these experimental details and the overall impact of MSC-EVs on skin regeneration is necessary.

METHODS

83 studies were identified in Web of Science, Embase, and PubMed that satisfied a set of prespecified inclusion criteria. A random effects meta-analysis was conducted for wound closure rate, scar width, blood vessel density and collagen deposition.

CONCLUSIONS

Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for wound healing and skin regeneration both in diabetic and non-diabetic animal models. Moreover, subgroup analyses demonstrated that apoptotic small extracellular vesicles (ApoSEVs) showed better efficacy than apoptotic bodies (ApoBDs) and small extracellular vesicles (sEVs) in wound closure outcome and collagen deposition, while sEVs displayed better than ApoEVs in revascularization. Among frequently used routes of administration, subcutaneous injection displayed a greater improvement to wound closure, collagen deposition and revascularization as compared to dressing/covering. Among easier-access source of MSCs, ADSCs demonstrated the best effect in wound closure rate and collagen deposition, as compared, BMMSCs displayed better in revascularization. Additionally, high heterogeneity observed in collection conditions, separation methods, storage methods, modifications, treatment dose, administration route, and frequency of MSC-EVs underscores the urgent need for standardization in these areas, prior to clinical translation.

PROTOCOL REGISTRATION

PROSPERO CRD42024499172.

Lipotoxicity Induces β-cell Small Extracellular Vesicle-Mediated β-cell Dysfunction in Male Mice

Chronically elevated circulating excess free fatty acids (ie, lipotoxicity) is a pathological process implicated in several metabolic disorders, including obesity-driven type 2 diabetes (T2D). Lipotoxicity exerts detrimental effects on pancreatic islet β-cells by reducing glucose-stimulated insulin secretion (GSIS), altering β-cell transcriptional identity, and promoting apoptosis. While β-cell-derived small extracellular vesicles (sEV) have been shown to contribute to β-cell failure in T2D, their specific role in lipotoxicity-mediated β-cell failure remains to be elucidated. In this work, we demonstrate that lipotoxicity enhances the release of sEVs from β-cells, which exhibit altered proteomic and lipidomic profiles. These palmitate (PAL)-exposed extracellular vesicles (EVs) induce β-cell dysfunction in healthy mouse and human islets and trigger significant islet transcriptional changes, including the upregulation of genes associated with the TGFβ/Smad3 pathway, as noted by RNA sequencing. Importantly, pharmacological inhibition of the TGFβI/II receptor improved PAL EV-induced β-cell dysfunction, underscoring their involvement in activating the TGFβ/Smad3 pathway during this process. We have comprehensively characterized lipotoxic β-cell sEVs and implicated their role in inducing β-cell functional failure in T2D. These findings highlight potential avenues for therapeutic interventions targeting sEV-mediated pathways to preserve β-cell health in metabolic disorders.

Extracellular Vesicles Analysis as Possible Signatures of Antiphospholipid Syndrome Clinical Features

Antiphospholipid syndrome (APS) is a rare autoimmune disease characterized by thrombosis and obstetric complications. Extracellular vesicles (EVs) of either platelet and endothelial origin are recognized to be involved in the pathophysiology of the disease. This study aimed to evaluate the potential role of endothelial- and platelet-derived extracellular vesicles and the clinical features or progression of APS. We enrolled 22 patients diagnosed with APS and 18 age and sex-matched healthy controls. We determined APS-specific antibody positivity and clinical manifestations in APS affected patients, with a focus on neurological, cardiovascular, dermatological, hematological manifestations, and pregnancy-related complications. Platelet-poor plasma was collected from either patients and controls for the analysis of EVs by flow cytometry technology using monoclonal antibodies to specifically identify those derived from either platelets and/or endothelial cells. EVs of endothelial and platelet origins were overall significantly increased in patients as compared to healthy controls. Furthermore, a significant association was also observed between the number of extracellular vesicles and specific organ involvement, particularly central nervous system manifestations, hematological abnormalities, and obstetric complications. An elevated proportion of endothelial-derived EVs in APS and a reduction of resting endothelial cell-derived EVs were observed in APS-affected women with obstetric complications. Our findings highlight the involvement of endothelial cells and platelets in mirroring the activities of endothelial cells and platelets in APS. Additionally, extracellular vesicles may serve as potential predictors of organ involvement and disease-related damage.

Cell Progression and Survival Functions of Enzymes Secreted in Extracellular Vesicles Associated with Breast and Prostate Cancers

Extracellular vesicles (EVs) are membrane-bound cargoes secreted by normal and pathological cells. Through their protein, nucleic acid, and lipid cargoes, EVs mediate several cellular processes, such as cell-cell communication, cell development, immune response, and tissue repair. Most importantly, through their enzyme cargo, EVs mediate pathophysiological processes, including the pathogenesis of cancer. In this review, we enumerate several enzymes secreted in EVs (EV enzyme cargo) from cells and patient clinical samples of breast and prostate cancers and detail their contributions to the progression and survival of both cancers. Findings in this review reveal that the EV enzyme cargo could exert cell progression functions via adhesion, proliferation, migration, invasion, and metastasis. The EV enzyme cargo might also influence cell survival functions of chemoresistance, radioresistance, angiogenesis, cell death inhibition, cell colony formation, and immune evasion. While the current literature provides evidence of the possible contributions of the EV enzyme cargo to the progression and survival mechanisms of breast and prostate cancers, future studies are required to validate that these effects are modified by EVs and provide insights into the clinical applications of the EV enzyme cargo in breast and prostate cancer.

Liquid biopsies in cancer

Cancer ranks among the most lethal diseases worldwide. Tissue biopsy is currently the primary method for the diagnosis and biological analysis of various solid tumors. However, this method has some disadvantages related to insufficient tissue specimen collection and intratumoral heterogeneity. Liquid biopsy is a noninvasive approach for identifying cancer-related biomarkers in peripheral blood, which allows for repetitive sampling across multiple time points. In the field of liquid biopsy, representative biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosomes. Many studies have evaluated the prognostic and predictive roles of CTCs and ctDNA in various solid tumors. Although these studies have limitations, the results of most studies appear to consistently demonstrate the correlations of high CTC counts and ctDNA mutations with lower survival rates in cancer patients. Similarly, a reduction in CTC counts throughout therapy may be a potential prognostic indicator related to treatment response in advanced cancer patients. Moreover, the biochemical characteristics of CTCs and ctDNA can provide information about tumor biology as well as resistance mechanisms against targeted therapy. This review discusses the current clinical applications of liquid biopsy in cancer patients, emphasizing its possible utility in outcome prediction and treatment decision-making.

Generation of Current Good Manufacturing Practices-Grade Mesenchymal Stromal Cell-Derived Extracellular Vesicles Using Automated Bioreactors

Interest in Current Good Manufacturing Practices (cGMP)-grade extracellular vesicles (EVs) is expanding. Some obstacles in this new but rapidly growing field include a lack of standardization and scalability. This review focuses on automated biomanufacturing of EVs in conditioned media collected from cultured mesenchymal stromal cells (MSCs). Different automated cell culture systems are discussed, including factors affecting EV quantity and quality, isolating EVs manufactured in an automated system, and validations needed. The ultimate goal when manufacturing cGMP-grade EVs is to identify a specific application and characterize the EV population in detail. This is achieved by validating every step of the process, choosing appropriate release criteria, and assuring batch-to-batch consistency. Due to the lack of standards in the field, it is critical to ensure that the cGMP-grade EVs meet FDA standards pertaining to identity, reproducibility, sterility, safety, purity, and potency. A closed-system automated bioreactor can be a valuable tool to generate cGMP-EVs in a scalable, economical, and reproducible manner.

Microglia-derived sEV: Friend or foe in the pathogenesis of cognitive impairment

As immune cells, microglia serve a dual role in cognition. Microglia-derived sEV actively contribute to the development of cognitive impairment by selectively targeting specific cells through various substances such as proteins, RNA, DNA, lipids, and metabolic waste. In recent years, there has been an increasing focus on understanding the pathogenesis and therapeutic potential of sEV. This comprehensive review summarizes the detrimental effects of M1 microglial sEV on pathogenic protein transport, neuroinflammation, disruption of the blood-brain barrier (BBB), neuronal death and synaptic dysfunction in relation to cognitive damage. Additionally, it highlights the beneficial effects of M2 microglia on alleviating cognitive impairment based on evidence from cellular experiments and animal studies. Furthermore, since microglial-secreted sEV can be found in cerebrospinal fluid or cross the BBB into plasma circulation, they play a crucial role in diagnosing cognitive impairment. However, using sEV as biomarkers is still at an experimental stage and requires further clinical validation. Future research should aim to explore the mechanisms underlying microglial involvement in various nervous system disorders to identify novel targets for clinical interventions.

Role of exosomes in diagnosis, prognostication, and treatment of pediatric solid tumors

Cancer is the second leading cause of death in children, and solid tumors make up 30% of childhood cancers. Molecular profiling of pediatric solid tumors allows a personalized approach to therapy, but this approach mostly relies on surgical biopsy, which is invasive and carries the risk of complications. Liquid biopsy serves as a reliable alternative and a minimally invasive tool for diagnosing, prognosticating, and residual disease monitoring in childhood cancers. This review outlines the potential of exosomes as informative liquid biopsies in pediatric solid tumors. Studies highlighting the potential applications and clinical utility of exosomes and their molecular constituents as prognosticators and therapies in common childhood solid tumors, including neuroblastoma, medulloblastoma, sarcoma, and hepatoblastoma, have been overviewed. We also discuss the limitations and technical challenges of utilizing exosomes for pediatric solid tumors.

Identification of distinct profiles of glioblastoma through the immunocapture of extracellular vesicles from patient plasma

Glioblastoma (GBM), a primary brain tumor, exhibits intratumoral heterogeneity and dynamic spatial-temporal changes. GBM-derived extracellular vesicles (EVs), reflecting tumor characteristics, present potential as liquid-biopsy markers for early diagnosis and monitoring. This study aims to evaluate molecular signatures of plasma-derived EVs from GBM patients using a conventional flow cytometer. EVs have been isolated from glioma patients and healthy controls (HCs) plasma using density gradient ultracentrifugation (DGU). EVs were evaluated by bead-based multiplex analysis in a conventional flow cytometer. Principal component analysis (PCA), hierarchical clustering, and correlation analysis provided comprehensive insights into EV characteristics. EVs successfully isolated were visualized in transmission and scanning electron microscopy (STEM). Bead-based multiplex analysis in flow cytometer detected the level of 37 EV surface markers, including tumor-related, cancer stem cell, endothelial cell, and immune cell- specific antigens. PCA identified the EV surface markers that are most significant for differentiating the subjects, and hierarchical clustering revealed four distinct clusters based on EV surface marker levels. EV molecular signature demonstrated considerable heterogeneity across patient clusters. The presence of CD29 emerged not only as a defining factor for a cluster of patients, but also served as a marker to differentiate patients from HCs.

Surface-Enhanced Raman Spectroscopy for Biomedical Applications: Recent Advances and Future Challenges

The year 2024 marks the 50th anniversary of the discovery of surface-enhanced Raman spectroscopy (SERS). Over recent years, SERS has experienced rapid development and became a critical tool in biomedicine with its unparalleled sensitivity and molecular specificity. This review summarizes the advancements and challenges in SERS substrates, nanotags, instrumentation, and spectral analysis for biomedical applications. We highlight the key developments in colloidal and solid SERS substrates, with an emphasis on surface chemistry, hotspot design, and 3D hydrogel plasmonic architectures. Additionally, we introduce recent innovations in SERS nanotags, including those with interior gaps, orthogonal Raman reporters, and near-infrared-II-responsive properties, along with biomimetic coatings. Emerging technologies such as optical tweezers, plasmonic nanopores, and wearable sensors have expanded SERS capabilities for single-cell and single-molecule analysis. Advances in spectral analysis, including signal digitalization, denoising, and deep learning algorithms, have improved the quantification of complex biological data. Finally, this review discusses SERS biomedical applications in nucleic acid detection, protein characterization, metabolite analysis, single-cell monitoring, and in vivo deep Raman spectroscopy, emphasizing its potential for liquid biopsy, metabolic phenotyping, and extracellular vesicle diagnostics. The review concludes with a perspective on clinical translation of SERS, addressing commercialization potentials and the challenges in deep tissue in vivo sensing and imaging.

Extracellular vesicles in cancer´s communication: messages we can read and how to answer

Extracellular vesicles (EVs) are emerging as critical mediators of intercellular communication in the tumor microenvironment (TME), profoundly influencing cancer progression. These nano-sized vesicles, released by both tumor and stromal cells, carry a diverse cargo of proteins, nucleic acids, and lipids, reflecting the dynamic cellular landscape and mediating intricate interactions between cells. This review provides a comprehensive overview of the biogenesis, composition, and functional roles of EVs in cancer, highlighting their significance in both basic research and clinical applications. We discuss how cancer cells manipulate EV biogenesis pathways to produce vesicles enriched with pro-tumorigenic molecules, explore the specific contributions of EVs to key hallmarks of cancer, such as angiogenesis, metastasis, and immune evasion, emphasizing their role in shaping TME and driving therapeutic resistance. Concurrently, we submit recent knowledge on how the cargo of EVs can serve as a valuable source of biomarkers for minimally invasive liquid biopsies, and its therapeutic potential, particularly as targeted drug delivery vehicles and immunomodulatory agents, showcasing their promise for enhancing the efficacy and safety of cancer treatments. By deciphering the intricate messages carried by EVs, we can gain a deeper understanding of cancer biology and develop more effective strategies for early detection, targeted therapy, and immunotherapy, paving the way for a new era of personalized and precise cancer medicine with the potential to significantly improve patient outcomes.