Neonatal heart tissue-derived EVs alleviate adult ischemic cardiac injury via regulating the function of macrophages and cardiac regeneration in murine models.

Previous studies confirmed the regenerative capacity of the mammalian neonatal heart. We recently found that adult heart tissue-derived EVs can protect the heart from myocardial ischemia-reperfusion (I/R). However, the role of EVs from neonatal heart tissue in cardiac healing post-ischemia remains unclear. In the present study, we revealed that intramyocardial administration of neonatal cardiac tissue-derived EVs (ncEVs) alleviated cardiac inflammation, mitigated reperfusion injury, and improved cardiac function in murine I/R models. In vitro, ncEVs inhibited M1 polarization of macrophages induced by LPS while up-regulated their phagocytic function via the miR-133a-3p-Ash1l signaling pathway. Moreover, the administration of ncEVs contributed to cardiac angiogenesis and improved cardiac function in murine myocardial infarction models. Collectively, these results suggested that neonatal heart-derived EVs can regulate the function of macrophages and contribute to cardiac regeneration and function recovery in murine cardiac ischemic models. Therefore, the derivatives in neonatal heart tissue-derived EVs might serve as a potential therapeutic strategy in ischemic diseases.

DNA nanotechnology for cell-free DNA marker for tumor detection: a comprehensive overview.

Advancements in DNA nanotechnology have led to new exciting ways to detect cell-free tumor biomarkers, revolutionizing cancer diagnostics. This article comprehensively reviews recent developments in this field, discussing the significance of liquid biopsies and DNA nanomachines in early cancer detection. The accuracy of cancer diagnosis at its early stages is expected to be significantly improved by identifying biomarkers. Liquid biopsies, offering minimally-invasive testing, hold the potential for capturing tumor-specific components like circulating tumor cells, cell-free DNA, and exosomes. DNA nanomachines are advanced molecular devices that exploit the programmability of DNA sequences for the ultrasensitive and specific detection of these markers. DNA nanomachines, nanostructures made of DNA that can be designable and switchable nanostructures, have a wide range of advantages for detecting tumor biomarkers, including non-invasiveness, affordability, high sensitivity, and specificity. Scientists also work on dealing with challenges like low marker concentrations and interference, which are addressed through microfluidic integration, nanomaterial amplification, and indirect signal detection. Despite advances, multiplex detection remains a challenge. In conclusion, DNA nanomachines bear immense promise for cancer diagnostics, advocating personalized treatment and improving patient outcomes. Continued research could redefine how we find and treat tumors, leading to better patient outcomes.

Unlocking the potential of extracellular vesicle circRNAs in breast cancer: From molecular mechanisms to therapeutic horizons.

Breast cancer remains the leading cause of cancer-related morbidity and mortality among women worldwide, underscoring the urgent need for novel diagnostic and therapeutic strategies. This review explores the emerging roles of circular RNAs (circRNAs) within extracellular vesicles (exosomes) in breast cancer. circRNAs, known for their stability and tissue-specific expression, are aberrantly expressed in breast cancer and regulate critical cellular processes such as proliferation, migration, and apoptosis, positioning them as promising biomarkers. Exosomes facilitate intercellular communication by delivering circRNAs, reflecting the physiological and pathological state of their source cells. This review highlights the multifaceted roles of exosomal circRNAs in promoting tumor growth, metastasis, and drug resistance through their modulation of tumor metabolism, the tumor microenvironment, and immune responses. In particular, we emphasize their contributions to chemotherapy resistance and their potential as both diagnostic markers and therapeutic targets. By synthesizing current research, this review provides novel insights into the clinical applications of exosomal circRNAs, offering a foundation for future studies aimed at improving breast cancer management through non-invasive diagnostics and targeted therapies.

Extracellular vesicles in sepsis plasma mediate neuronal inflammation in the brain through miRNAs and innate immune signaling.

BACKGROUND: Neuroinflammation reportedly plays a critical role in the pathogenesis of sepsis-associated encephalopathy (SAE). We previously reported that circulating plasma extracellular vesicles (EVs) from septic mice are proinflammatory. In the current study, we tested the role of sepsis plasma EVs in neuroinflammation. METHODS: To track EVs in cells and tissues, HEK293T cell-derived EVs were labeled with the fluorescent dye PKH26. Cecal ligation and puncture (CLP) was conducted to model polymicrobial sepsis in mice. Plasma EVs were isolated by ultracentrifugation and their role in promoting neuronal inflammation was tested following intracerebroventricular (ICV) injection. miRNA inhibitors (anti-miR-146a, -122, -34a, and -145a) were applied to determine the effects of EV cargo miRNAs in the brain. A cytokine array was performed to profile microglia-released protein mediators. TLR7- or MyD88-knockout (KO) mice were utilized to determine the underlying mechanism of EVs-mediated neuroinflammation. RESULTS: We observed the uptake of fluorescent PKH26-EVs inside the cell bodies of both microglia and neurons. Sepsis plasma EVs led to a dose-dependent cytokine release in cultured microglia, which was partially attenuated by miRNA inhibitors against the target miRNAs and in TLR7-KO cells. When administered via the ICV, sepsis plasma EVs resulted in a marked increase in the accumulation of innate immune cells, including monocyte and neutrophil and cytokine gene expression, in the brain. Although sepsis plasma EVs had no direct effect on cytokine production or neuronal injury in vitro, the conditioned media (CM) of microglia treated with sepsis plasma EVs induced neuronal cell death as evidenced by increased caspase-3 cleavage and Annexin-V staining. Cytokine arrays and bioinformatics analysis of the microglial CM revealed multiple cytokines/chemokines and other factors functionally linked to leukocyte chemotaxis and migration, TLR signaling, and neuronal death. Moreover, sepsis plasma EV-induced brain inflammation in vivo was significantly dependent on MyD88. CONCLUSIONS: Circulating plasma EVs in septic mice cause a microglial proinflammatory response in vitro and a brain innate immune response in vivo, some of which are in part mediated by TLR7 in vitro and MyD88 signaling in vivo. These findings highlight the importance of circulating EVs in brain inflammation during sepsis.

Extracellular vesicles in parasitic protozoa: Impact of Leishmania exosomes containing Leishmania RNA virus 1 (LRV1) on Leishmania infectivity and disease progression.

This chapter focuses on the interplay between Leishmania parasites and their host, particularly on Leishmania RNA virus (LRVs) and extracellular vesicles (EVs) in modulating host-pathogen interactions. Leishmania EVs have been shown to facilitate gene transfer, including drug-resistance genes, enhancing the parasites' survival and resistance to antileishmanial therapeutics. These EVs also play a significant role in host immune modulation by altering cytokine production in macrophages and promoting an anti-inflammatory environment that favours parasitic persistence. The presence of virulence factors such as GP63 within these EVs further underscores their role in the parasite's immunopathogenesis. Over the last few decades, LRVs have been established as drivers of the severity and persistence of leishmaniasis by exacerbating inflammatory responses and potentially influencing treatment outcomes. This chapter discusses the evolutionary origins and classification of these viruses, and explores their role in parasitic pathogenicity, highlighting their ubiquity across protozoan parasites and their impact on disease progression.

Comment on "Extracellular Vesicles Slow Down Aß(1-42) Aggregation by Interfering with the Amyloid Fibril Elongation Step".

Halipi et al. explored the impact of extracellular vesicles (EVs) on amyloid-ß (Aß) aggregation. They concluded that EVs reduce Aß aggregation, as seen by shorter and thicker fibrils. While we agree with the complex role of EVs in Alzheimer's disease, we are sceptical of the claim that EVs slow down Aß aggregation, noting missing key references. Previous literature rather suggests that EVs (derived from neuronal cell lines) accelerate the process of Aß fibrillation and plaque formation. Halipi et al.'s findings may be skewed due to the lack of essential neuronally expressed Aß-binding partners, like the prion protein (PrPC) in their EV samples. The commentary, in the light of included original experiments and cited literature, suggests that membrane proteins like PrPC are crucial to fully understand the role of EVs in Aß aggregation, and Halipi et al.'s conclusions should be reexamined in light of these factors.

MicroRNA Expression in Exosome Extracellular Vesicles as Targets for Personalized Medicine in Diffuse Large B Cell Lymphoma Patients with HIV Infection.

Extracellular Vesicles (EVs), more specifically exosomes (xEVs), have been associated with Diffuse Large B-cell Lymphoma (DLBCL). These xEVs contain a variety of biomolecules, such as proteins and nucleic acids (e.g., microRNA, LncRNA, and DNA). The expressions of these vesicles in the setting of Human Immunodeficiency Virus (HIV) have been linked to disease progression. Studies have explored the use of EVs in more practical clinical settings. Several studies have found that biomolecules within xEVs can serve to detect disease progression. The biomolecule content within xEVs is useful in prognostication and has even been associated with mechanisms of resistance for some DLBCL treatment modalities. This review article explores the role of xEV biomolecule content in DLBCL progression in the context of HIV infection and its applied use in practical disease management.

Immunomodulatory effects of immune cell-derived extracellular vesicles in melanoma.

Melanoma, recognized as one of the most immunogenic malignancies in humans, holds paramount significance in the realm of immunotherapy. However, the emergence of drug resistance and the occurrence of adverse drug reactions underscore the pressing need to explore increasingly personalized immunotherapeutic modalities. Extracellular Vesicles (EVs), pivotal derivatives of immune cells, assume pivotal roles by encapsulating proteins, lipids, and nucleic acids within bilayer lipid structures, thereby facilitating targeted delivery to other immune cells. This orchestrated process orchestrates critical functions including antigen presentation, immune modulation, and the induction of apoptosis in tumor cells. A burgeoning body of evidence underscores the vast therapeutic potential of EVs in melanoma treatment. This comprehensive review aims to delineate the roles of EVs derived from immune cells such as dendritic cells, natural killer cells, macrophages, and T cells in the context of melanoma patients, thereby furnishing invaluable insights for the future direction of melanoma immunotherapy.

Molecular profiling of blood plasma-derived extracellular vesicles derived from Duchenne muscular dystrophy patients through integration of FTIR spectroscopy and machine learning reveals disease signatures.

PURPOSE: To identify and monitor the FTIR spectral signatures of plasma extracellular vesicles (EVs) from Duchenne Muscular Dystrophy (DMD) patients at different stages with Healthy controls using machine learning models. MATERIALS AND METHODS: Whole blood samples were collected from the DMD (n = 30) and Healthy controls (n = 12). EVs were extracted by the Total Exosome Isolation (TEI) Method and resuspended in 1XPBS. We characterize the morphology, size, particle count, and surface markers (CD9, Alix, and Flotillin) by HR-TEM, NTA, and Western Blot analysis. The mid-IR spectra were recorded from (4000-400 cm-1) by Bruker ALPHA II FTIR spectrometer model, which was equipped with an attenuated total reflection (ATR) module. Machine learning algorithms like Principal Component Analysis (PCA) and Random Forest (RF) for dimensionality reduction and classifying the two study groups based on the FTIR spectra. The model performance was evaluated by a confusion matrix and the sensitivity, specificity, and Receiver Operating Characteristic Curve (ROC) was calculated respectively. RESULTS: Alterations in Amide I & II (1700-1470 cm-1) and lipid (3000-2800 cm-1) regions in FTIR spectra of DMD compared with healthy controls. The PCA-RF model classified correctly the two study groups in the range of 4000-400 cm-1 with a sensitivity of 20 %, specificity of 87.50 %, accuracy of 71.43 %, precision of 33.33 %, and 5-fold cross-validation accuracy of 82 %. We analyzed the ten different spectral regions which showed statistically significant at P < 0.01 except the Ester Acyl Chain region. CONCLUSION: Our proof-of-concept study demonstrated distinct infrared (IR) spectral signatures in plasma EVs derived from DMD. Consistent alterations in protein and lipid configurations were identified using a PCA-RF model, even with a small clinical dataset. This minimally invasive liquid biopsy method, combined with automated analysis, warrants further investigation for its potential in early diagnosis and monitoring of disease progression in DMD patients within clinical settings.

Metabolic landscaping of extracellular vesicles from body fluids by phosphatidylserine imprinted polymer enrichment and mass spectrometry analysis.

Extracellular vesicles (EVs) are emerging as new source of biomarkers discovery in liquid biopsy due to their stabilization in body fluids, protected by phospholipid bilayers. However, the metabolomics study of EVs is very little reported due to the lack of efficient and high-throughput isolation methods for clinical samples. In this study, phosphatidylserine imprinted polymers were employed for rapid and efficient EVs isolation from five human body fluids, including plasma, urine, amniotic fluid, cerebrospinal fluid, and saliva. The isolated EVs were subsequently analyzed for metabolomic studies by high-resolution mass spectrometry. Metabolic landscaping was conducted between the body fluids and their EVs, indicating EVs contain a large number of metabolites that are completely specific to the body fluid source. Finally, quantitative metabolomic analysis of EVs was carried out with plasma samples of hepatocellular carcinoma. Several differentially expressed exosomal metabolites were revealed including the upregulation of sphingosine (d18:1), taurochenodeoxycholic acid (TCDCA), pipecolic acid (PA), and 4-hydroxynonenal (4-HNE) and down-regulation of piperine, caffeine, and indole. We believe the proposed methodology will provide a deeper understanding of the molecular composition and functions of EVs as an alternative source for biomarker discovery.

Differential proteins from EVs identification based on tandem mass tags analysis and effect of Treg-derived EVs on T-lymphocytes in COPD patients.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a widespread respiratory disease. This study examines extracellular vesicles (EVs) and proteins contained in EVs in COPD. METHODS: Blood samples were collected from 40 COPD patients and 10 health controls. Cytokines including IFN-γ, TNF-α, IL-1ß, IL-6, IL-8, and IL-17, were measured by ELISA. Small EVs samples were extracted from plasma and identified by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blot. Protein components contained in EVs were analyzed by Tandem Mass Tags (TMT) to identify differential proteins. Treg-derived EV was extracted and added to isolated CD8+, Treg, and Th17 subsets to assess its effect on T-lymphocytes. RESULTS: ELISA revealed higher levels of all cytokines and flow cytometry suggested a higher proportion of Treg and Th17 cells in COPD patients. After identification, TMT analysis identified 207 unique protein components, including five potential COPD biomarkers: BTRC, TRIM28, CD209, NCOA3, and SSR3. Flow cytometry revealed that Treg-derived EVs inhibited differentiation into CD8+, CD4+, and Th17 cells. CONCLUSION: The study shows that cytokines, T-lymphocyte subsets differences in COPD and Treg-derived EVs influence T-lymphocyte differentiation. Identified biomarkers may assist in understanding COPD pathogenesis, prognosis, and therapy. The study contributes to COPD biomarker research.

Proteomics Studies on Extracellular Vesicles Derived from Glioblastoma: Where Do We Stand?

Like most tumors, glioblastoma multiforme (GBM), the deadliest brain tumor in human adulthood, releases extracellular vesicles (EVs). Their content, reflecting that of the tumor of origin, can be donated to nearby and distant cells which, by acquiring it, become more aggressive. Therefore, the study of EV-transported molecules has become very important. Particular attention has been paid to EV proteins to uncover new GBM biomarkers and potential druggable targets. Proteomic studies have mainly been performed by "bottom-up" mass spectrometry (MS) analysis of EVs isolated by different procedures from conditioned media of cultured GBM cells and biological fluids from GBM patients. Although a great number of dysregulated proteins have been identified, the translation of these findings into clinics remains elusive, probably due to multiple factors, including the lack of standardized procedures for isolation/characterization of EVs and analysis of their proteome. Thus, it is time to change research strategies by adopting, in addition to harmonized EV selection techniques, different MS methods aimed at identifying selected tumoral protein mutations and/or isoforms due to post-translational modifications, which more deeply influence the tumor behavior. Hopefully, these data integrated with those from other "omics" disciplines will lead to the discovery of druggable pathways for novel GBM therapies.

Extracellular Vesicle miRNAs in Diagnostics of Gastric Cancer.

Gastric cancer (GC) poses a significant global health challenge because of its high mortality rate attributed to the late-stage diagnosis and lack of early symptoms. Early cancer diagnostics is crucial for improving the survival rates in GC patients, which emphasizes the importance of identifying GC markers for liquid biopsy. The review discusses a potential use of extracellular vesicle microRNAs (EV miRNAs) as biomarkers for the diagnostics and prognostics of GC. Methods. Original articles on the identification of EV miRNA as GC markers published in the Web of Science and Scopus indexed issues were selected from the PubMed and Google Scholar databases. We focused on the methodological aspects of EV analysis, including the choice of body fluid, methods for EV isolation and validation, and approaches for EV miRNA analysis. Conclusions. Out of 33 found articles, the majority of authors investigated blood-derived extracellular vesicles (EVs); only a few utilized EVs from other body fluids, including tissue-specific local biofluids (washing the tumor growth areas), which may be a promising source of EVs in the context of cancer diagnostics. GC-associated miRNAs identified in different studies using different methods of EV isolation and analysis varied considerably. However, three miRNAs (miR-10b, miR-21, and miR-92a) have been found in several independent studies and shown to be associated with GC in experimental models. Further studies are needed to determine the optimal miRNA marker panel. Another essential step necessary to improve the reliability and reproducibility of EV-based diagnostics is standardization of methodologies for EV handling and analysis of EV miRNA.

Extracellular Vesicles & Co.: scaring immune cells in the TME since ever.

The health tissue surrounding a solid tumor, namely the tumor microenvironment (TME), is an extremely complex universe of cells, extracellular matrix, and signals of various nature, that support and protect the growth of cancer cells. The interactions taking place between cancer cells and the TME are crucial not only for tumor growth, invasion, and metastasis but they also play a key role in modulating immune system responses to cancer, and vice-versa. Indeed, tumor-infiltrating immune cells (e.g., T lymphocytes and natural killers) activity is greatly affected by signals (mostly ligands/receptors and paracrine) they receive in the TME, which frequently generate an immunosuppressive milieu. In the last years, it has become evident that soluble and receptor signaling is not the only way of communication between cells in the TME, with extracellular vesicles, such as exosomes, playing a central role. Among the different new kind of vesicles recently discovered, migrasomes look like to be of extreme interest as they are not only different from the others, but also have been reported as able to deliver a very heterogeneous kind of messages, able to profoundly affect recipient cells' behavior. Indeed, the role played by the different classes of extracellular vesicles, especially in the TME, relies on their not-directional diffusion from the originating cells, while migrasomes released from migrating cells do have a directional effect. Migrasomes biology and their involvement in cancer progression, dissemination, and resistance to therapy is still a largely obscure field, but with promising development foreseen in the next future.

Comparison of Lung Tissue-Derived Extracellular Vesicles Using Multiple Dissociation Methods for Profiling Protein Biomarkers.

Extracellular vesicles (EVs) operate as chemical messengers that facilitate intercellular communication. Emerging evidence has demonstrated that lung tissue-derived EVs play pivotal roles in pulmonary physiological processes and have potential as biomarkers and therapeutics for lung diseases. Multiple methods have been proposed for the isolation of lung tissue-derived EVs. However, the effects of different tissue pre-treatments on lung EV isolation and subsequent disease biomarker discovery have not yet been comprehensively investigated. In this study, we compared the physical characteristics, recovery yields, and protein compositions of EVs isolated from lung tissues using three methods based on different tissue dissociation principles. Methodologically, the beneficial roles of blood perfusion and gentle meshing were emphasized based on their impact on EV yield and purity. These results demonstrate that different methods enrich distinct subpopulations of EVs that exhibit significant differences in their protein cargo and surface properties. These disparities directly affect the diagnostic detection of marker proteins related to lung diseases, including lung tumors, asthma, and pulmonary fibrosis. Collectively, these findings highlight the variations in EV characteristics resulting from the applied approaches and offer compelling suggestions for guiding researchers in selecting a suitable isolation method based on downstream functional studies and clinical applications.

Clusterin-carrying extracellular vesicles derived from human umbilical cord mesenchymal stem cells restore the ovarian function of premature ovarian failure mice through activating the PI3K/AKT pathway.

BACKGROUND: Emerging evidence has highlighted the therapeutic potential of human umbilical cord mesenchymal stem cells (UC-MSCs) in chemotherapy-induced premature ovarian failure (POF). This study was designed to investigate the appropriate timing and molecular mechanism of UC-MSCs treatment for chemotherapy-induced POF. METHODS: Ovarian structure and function of mice were assessed every 3 days after injections with cyclophosphamide (CTX) and busulfan (BUS). UC-MSCs and UC-MSCs-derived extracellular vesicles (EVs) were infused into mice via the tail vein, respectively. Ovarian function was analyzed by follicle counts, the serum levels of hormones and ovarian morphology. The apoptosis and proliferation of ovarian granulosa cells were analyzed in vitro and in vivo. Label-free quantitative proteomics was used to detect the differentially expressed proteins in UC-MSC-derived EVs. RESULTS: After CTX/BUS injection, we observed that the ovarian function of POF mice was significantly deteriorated on day 9 after CTX/BUS infusion. TUNEL assay indicated that the number of apoptotic cells in the ovaries of POF mice was significantly higher than that in normal mice on day 3 after CTX/BUS injection. Transplantation of UC-MSCs on day 6 after CTX/BUS injection significantly improved ovarian function, enhanced proliferation and inhibited apoptosis of ovarian granulosa cells, whereas the therapeutic effect of UC-MSCs transplantation decreased on day 9, or day 12 after CTX/BUS injection. Moreover, EVs derived from UC-MSCs exerted similar therapeutic effects on POF. UC-MSCs-derived EVs could activate the PI3K/AKT signaling pathway and reduce ovarian granulosa cell apoptosis. Quantitative proteomics analysis revealed that clusterin (CLU) was highly expressed in the EVs of UC-MSCs. The supplementation of CLU proteins prevented ovarian granulosa cells from chemotherapy-induced apoptosis. Further mechanistic analysis showed that CLU-knockdown blocked the PI3K/AKT signaling and reversed the protective effects of UC-MSCs-derived EVs. CONCLUSIONS: Administration of UC-MSCs and UC-MSCs-derived EVs on day 6 of CTX/BUS injection could effectively improve the ovarian function of POF mice. UC-MSCs-derived EVs carrying CLU promoted proliferation and inhibited apoptosis of ovarian granulosa cells through activating the PI3K/AKT pathway. This study identifies a previously unrecognized molecular mechanism of UC-MSCs-mediated protective effects on POF, which pave the way for the use of cell-free therapeutic approach for POF.

Postoperative Organ Dysfunction Risk Stratification Using Extracellular Vesicle-Derived circRNAs in Pediatric Congenital Heart Surgery.

Breakthroughs in surgical and medical techniques have significantly improved outcomes for children with congenital heart disease (CHD), but research continues to address the ongoing challenge of organ dysfunction after surgery, particularly in neonates and infants. Our study explored circular RNAs (circRNAs) within plasma-derived extracellular vesicles (EVs) in neonates and infants undergoing CHD surgery. Post-surgery EV circRNAs showed dramatic expression changes between organ dysfunction (OD) and control groups. Tissue injury-related pathways were consistent across pre- and post-surgery in OD. The top two significant predicted tissue sources of these circRNAs originated from the respiratory system, aligning with the fact that all patients in the OD arm experienced respiratory dysfunction. Five of these circRNAs, namely circ-CELSR1, circ-PLXNA1, circ-OBSL1, circ-DAB2IP, and circ-KANK1, significantly correlated with PELOD (Pediatric Logistic Organ Dysfunction) score and demonstrated high performance (AUC = 0.95), supporting the potential of circRNAs as prognostic markers. These findings pave the way for EV circRNAs as promising tools for managing post-surgical organ dysfunction and potentially guiding therapeutic strategies in children with CHD.

Extracellular vesicles and their therapeutic applications: a review article (part 2).

Extracellular vesicles (EVs) have emerged as a fascinating area of research in molecular biology, with diverse therapeutic applications. These small membrane-bound structures, released by cells into the extracellular space, play a crucial role in intercellular communication and hold great potential for advancing medical treatments. The aim of this study is to have a narrative review on the use and therapeutic applications of EVs. Their unique characteristics, including stability, biocompatibility, and the ability to traverse biological barriers, make them promising tools for targeted drug delivery. By engineering EVs to encapsulate specific cargo molecules, such as therapeutic proteins, small interfering RNA (siRNA), or anti-cancer drugs, researchers can enhance drug stability and improve targeted delivery to desired cells or tissues. This approach can minimize off-target effects and improve therapeutic efficacy. Based on our literature search, we found that EVs can be used as biomarkers to predict diseases. Although much progress has been made in understanding the biology and function of exosomes, there are still unanswered questions that require further research. This includes identifying appropriate and safe techniques for producing exosomes in large quantities, determining which types of cells are suitable for exosome donor cells for therapeutic purposes, and investigating the safety of exosomes in human studies. Overall, the use of exosomes in clinical therapeutic applications requires a strong understanding of molecular signaling cascades and exosome profiles, as well as the specificity and sensitivity of biomarker and drug delivery methods.

Leukocyte Extracellular Vesicles Predict Progression of Systolic Dysfunction in Heart Failure with Mildly Reduced Ejection Fraction (LYCHEE) - A Prospective, Multicentre Cohort Study.

Risk stratification in heart failure with mildly-reduced ejection fraction (HFmrEF) remains challenging. We evaluated the predictive value of advanced glycation end products (AGEs) and plasma concentrations of extracellular vesicles (EVs) for the systolic and diastolic dysfunction progression in HFmrEF patients. Skin AGE accumulation was measured using AGE Reader. Plasma EV concentrations were measured using flow cytometry. Among 74 patients enrolled, 13 (18%) had systolic dysfunction progression and 5 (7%) had diastolic dysfunction progression during 6.5 months follow-up. Leukocyte EVs concentrations were higher in patients with systolic dysfunction progression (p = 0.002) and predicted the progression with 75.0% sensitivity and 58.3% specificity, independent of other clinical variables (OR 4.72, 95% CI 0.99-22.31). Skin AGE levels and concentrations of other EV subtypes were not associated with systolic or diastolic dysfunction progression. Increased leukocyte EVs concentrations are associated with 4.7-fold higher odds of systolic dysfunction progression in HFmrEF patients.