Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

MicroRNAs in vascular smooth muscle cells: Mechanisms, therapeutic potential, and advances in delivery systems

Vascular smooth muscle cells (VSMCs) are essential players in a wide range of physiological processes, and their phenotypic transitions are critical in the development of vascular diseases such as atherosclerosis (AS), restenosis, aortic dissection/aneurysm (AAD), chronic kidney disease (CKD), and diabetes mellitus (DM). MicroRNAs (miRNAs), a class of short non-coding RNAs, regulates key cellular functions like proliferation, migration, and apoptosis by modulating gene expression. Numerous studies have shown that various miRNAs play pivotal roles in the pathophysiological processes of VSMCs, with VSMC phenotype switching being a key factor. To harness miRNAs as therapeutic tools, researchers have focused on developing efficient delivery vectors, including exosomes, nanoparticles, and viral vectors. Recently, the exploration of miRNA characteristics and delivery mechanisms has led to the emergence of innovative systems, such as scaffold-based localized delivery methods, platelet-like fusion lipid nanoparticles(PLPs), liposome-exosome hybrid carriers, and stimulus-responsive delivery systems like miRNA micelles. These cutting-edge delivery systems not only enhance our understanding of miRNA's role in disease but also offer promising new strategies for gene therapy, paving the way for more precise and effective treatments in the future.

Extracellular Vesicles Delivered by a Nanofiber-Hydrogel Composite Enhance Healing In Vivo in a Model of Crohn's Disease Perianal Fistula

Perianal fistulas represent a common, aggressive, and disabling complication of Crohn's disease (CD). Despite recent drug developments, novel surgical interventions as well as multidisciplinary treatment approaches, the outcome is dismal, with >50% therapy failure rates. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) offer potential therapeutic benefits for treating fistulizing CD, due to the pro-regenerative paracrine signals. However, a significant obstacle to clinical translation of EV-based therapy is the rapid clearance and short half-life of EVs in vivo. Here, an injectable, biodegradable nanofiber-hydrogel composite (NHC) microgel matrix that serves as a carrier to deliver MSC-derived EVs to a rat model of CD perianal fistula (PAF) is reported. It is found that EV-loaded NHC (EV-NHC) yields the best fistula healing when compared to other treatment arms. The MRI assessment reveals that the EV-NHC reduces inflammation at the fistula site and promotes tissue healing. The enhanced therapeutic outcomes are contributed by extended local retention and sustained release of EVs by NHC. In addition, the EV-NHC effectively reduces inflammation at the fistula site and promotes tissue healing and regeneration via macrophage polarization and neo-vascularization. This EV-NHC platform provides an off-the-shelf solution that facilitates its clinical translation.

HSP90 N-terminal inhibition promotes mitochondria-derived vesicles related metastasis by reducing TFEB transcription via decreased HSP90AA1-HCFC1 interaction in liver cancer

Cancer cells compensate with increasing mitochondria-derived vesicles (MDVs) to maintain mitochondrial homeostasis, when canonical MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta)-mediated mitophagy is lacking. MDVs promote the transport of mitochondrial components into extracellular vesicles (EVs) and induce tumor metastasis. Although HSP90 (heat shock protein 90) chaperones hundreds of client proteins and its inhibitors suppress tumors, HSP90 inhibitors-related chemotherapy is associated with unexpected metastasis. Herein, we find that HSP90 inhibitor causes mitochondrial damage but stimulates the low LC3-induced MDVs and the release of MDVs-derived EVs. However, why LC3 decreases and what is the transcriptional regulatory mechanism of MDVs formation under HSP90 inhibition remain unknown. Because TFEB (transcription factor EB) is the most important mitophagy transcription factor, and the HSP90 client HCFC1 (host cell factor C1) regulates TFEB transcription, there should be a hidden connection between TFEB, HCFC1 and HSP90 in MDVs formation. Our results support the idea that HSP90 N-terminal inhibition reduces TFEB transcription via decreased HSP90AA1-HCFC1 interaction, which prevents HCFC1 from binding to the TFEB proximal promoter region. Decreased TFEB transcription and consequently reduced LC3, ultimately promoted MDVs formation. Blocking MDVs formation with the microtubule inhibitor nocodazole (NOC) activates the HCFC1-TFEB-LC3 axis, weakens HSP90 inhibitors-induced MDVs and the release of MDVs-derived EVs, inhibits the growth of tumor cell spheres and primary liver tumors, and reduces the extravasation of cancer cells to secondary metastatic sites. Taken together, these data suggest that combination therapy should be used to reduce the metastatic risk of low TFEB-triggered-MDVs formation caused by HSP90 inhibitors.Abbreviation: ACIs: ATP-competitive inhibitors; BaFA1: bafilomycin A1; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; CTD: C-terminal domain; EVs: extracellular vesicles; HCFC1: host cell factor C1; HSP90: heat shock protein 90; ILVs: intralumenal vesicles; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MD: middle domain; MDVs: mitochondria-derived vesicles; MQC: mitochondrial quality control; ΔΨm: mitochondrial membrane potential; MVBs: multivesicular bodies; NB: novobiocin; TEM: transmission electron microscopy; TFEB: transcription factor EB; TFs: transcription factors. NOC: nocodazole; NTD: N-terminal nucleotide binding domain; OCR: oxygen consumption rate; RFP: red fluorescent protein; ROS: reactive oxygen species; STA9090: Ganetespib; VPS35: VPS35 retromer complex component.

hESC-derived extracellular vesicles enriched with MFGE-8 and the GSH redox system act as senotherapeutics for neural stem cells in ischemic stroke

Human embryonic stem cells (hESCs) and their extracellular vesicles (EVs) hold significant potential for tissue repair and regeneration. Neural stem cells (NSCs) in the adult brain often acquire senescent phenotypes after ischemic injuries, releasing neurodegenerative senescence-associated secretory phenotype factors. In this study, we investigated the senotherapeutic effects of hESC-EVs on NSCs and confirmed their neuroprotective effects in neurons via rejuvenation of NSC secretions. Proteomic profiling of hESC-EVs identified MFGE-8 as a critical bridging molecule to NSCs. We also found that the glutathione (GSH) redox system is a key contributor to the therapeutic antioxidant activity of hESC-EVs. Additionally, EVs produced by the hypoxic preconditioning of hESCs (hESC-HypoxEVs) exhibited reinforced GSH redox capacity and further enhanced the senotherapeutic effects on NSCs compared to naïve hESC-EVs. We also demonstrated that administration of hESC-HypoxEVs, precoated with MFGE-8, significantly increased the populations of NSCs and newborn neurons in the subventricular zone of the brain and improved sensorimotor functions in a rat model of ischemic stroke. Our study suggests that combining hESC-HypoxEVs with MFGE-8 may serve as an effective therapeutic modality for reversing senescence and enhancing the neurogenic potential of NSCs to treat neurodegenerative diseases.

Mesenchymal Stromal Cell Exosome-Induced Vascular Regeneration in a PCOS Mouse Model

The efficacy of Bone Marrow Mesenchymal Stem Cell-derived Exosomes (BMSCs-Exo) in addressing the complexities of Polycystic Ovary Syndrome (PCOS) has been explored in a controlled experimental study using a DHEA-induced PCOS model in 6-8-week-old female NMRI mice. This research undertook an in vivo approach with fifteen female murine subjects to investigate the potential of BMSCs-Exo in promoting vascular regeneration and alleviating the adverse effects associated with PCOS. Through a strategic intervention, the study aimed to modulate the pathophysiological markers of oxidative stress and inflammation that are hallmark features of PCOS. Remarkably, the administration of BMSCs-Exo led to decreased CD31 expression in ovarian tissues, suggesting reduced angiogenesis and endothelial activation. Moreover, a significant reduction in pro-inflammatory cytokines and oxidative stress markers was noted, aligning closely with the metrics observed in the control group. These findings illuminate a promising therapeutic avenue utilizing BMSCs-Exo to recalibrate angiogenic, inflammatory, and oxidative stress responses in PCOS. This research not only contributes to the current understanding of PCOS management but also opens new doors for innovative clinical treatments.

Toward Identification of Markers for Brain-Derived Extracellular Vesicles in Cerebrospinal Fluid: A Large-Scale, Unbiased Analysis Using Proximity Extension Assays

Extracellular vesicles (EVs) captured in biofluids have opened a new frontier for liquid biopsies. To enrich for vesicles coming from a particular cell type or tumour, scientists utilize antibodies to transmembrane proteins that are relatively unique to the cell type of interest. However, recent evidence has called into question the basic assumption that all transmembrane proteins measured in biofluids are, in fact, EV-associated. To identify both candidate markers for brain-derived EV immunocapture and cargo proteins to validate the EVs' cell of origin, we conducted an unbiased Olink screen, measuring 5416 unique proteins in cerebrospinal fluid after size exclusion chromatography. We identified proteins that demonstrated a clear EV fractionation pattern and created a searchable dataset of candidate EV-associated markers-both proteins that are cell type-specific within the brain, and proteins found across multiple cell types for use as general EV markers. We further implemented the DeepTMHMM deep learning model to differentiate predicted cytosolic, transmembrane, and external proteins and found that intriguingly, only 10% of the predicted transmembrane proteins have a clear EV fractionation pattern based on our stringent criteria. This dataset further bolsters the critical importance of verifying EV association of candidate proteins using methods such as size exclusion chromatography before downstream use of the targets for EV analysis.

The role of extracellular vesicles in non-alcoholic steatohepatitis: Emerging mechanisms, potential therapeutics and biomarkers

Non-alcoholic steatohepatitis (NASH), an emerging global healthcare problem, has become the leading cause of liver transplantation in recent decades. No effective therapies in the clinic have been proven due to the incomplete understanding of the pathogenesis of NASH, and further studies are expected to continue to delve into the mechanisms of NASH. Extracellular vesicles (EVs), which are small lipid membrane vesicles carrying proteins, microRNAs and other molecules, have been identified to play a vital role in cell-to-cell communication and are involved in the development and progression of various diseases. In recent years, there has been increasing interest in the role of EVs in NASH. Many studies have revealed that EVs mediate important pathological processes in NASH, and the role of EVs in NASH is distinct and variable depending on their origin cells and target cells. This review outlines the emerging mechanisms of EVs in the development of NASH and the preclinical evidence related to stem cell-derived EVs as a potential therapeutic strategy for NASH. Moreover, possible strategies involving EVs as clinical diagnostic, staging and prognostic biomarkers for NASH are summarized.

Multiplexed PLGA scaffolds with nitric oxide-releasing zinc oxide and melatonin-modulated extracellular vesicles for severe chronic kidney disease

INTRODUCTION

With prevalence of chronic kidney disease (CKD) in worldwide, the strategies to recover renal function via tissue regeneration could provide alternatives to kidney replacement therapies. However, due to relatively low reproducibility of renal basal cells and limited bioactivities of implanted biomaterials along with the high probability of substance-inducible inflammation and immunogenicity, kidney tissue regeneration could be challenging.

OBJECTIVES

To exclude various side effects from cell transplantations, in this study, we have induced extracellular vesicles (EVs) incorporated cell-free hybrid PMEZ scaffolds.

METHODS

Hybrid PMEZ scaffolds incorporating essential bioactive components, such as ricinoleic acid grafted Mg(OH)2 (M), extracellular matrix (E), and alpha lipoic acid-conjugated ZnO (Z) based on biodegradable porous PLGA (P) platform was successfully manufactured. Consecutively, for functional improvements, melatonin-modulated extracellular vesicles (mEVs), derived from the human umbilical cord MSCs in chemically defined media without serum impurities, were also loaded onto PMEZ scaffolds to construct the multiplexed PMEZ/mEV scaffold.

RESULTS

With functionalities of Mg(OH)2 and extracellular matrix-loaded PLGA scaffolds, the continuous nitric oxide-releasing property of modified ZnO and remarkably upregulated regenerative functionalities of mEVs showed significantly enhanced kidney regenerative activities. Based on these, the structural and functional restoration has been practically achieved in 5/6 nephrectomy mouse models that mimicked severe human CKD.

CONCLUSION

Our study has proved the combinatory bioactivities of the biodegradable PLGA-based multiplexed scaffold for kidney tissue regeneration in 5/6 nephrectomy mouse representing a severe CKD model. The optimal microenvironments for the morphogenetic formations of renal tissues and functional restorations have successfully achieved the combinatory bioactivities of remarkable components for PMEZ/mEV, which could be a promising therapeutic alternative for CKD treatment.

Salivary Extracellular Vesicles Separation: Analysis of Ultracentrifugation-Based Protocols

INTRODUCTION

The clinical potential of extracellular vesicles (EVs) is widely acknowledged, yet the standardization and reproducibility of its separation remain challenging. This study compares three protocols: ultracentrifugation (UC), UC with purification step (UC + PS), and a combined protocol using polymer-based precipitation and UC (PBP + UC).

METHODS

Salivary samples were collected from healthy donors. EVs were separated (UC, UC + PS, and PBP + UC) and characterized using transmission electron microscopy, nanoparticle tracking analysis, EV purity, RNA concentration, and Western blotting. miRNA expression was evaluated by quantitative RT-PCR. Statistical analyses comparing groups were performed using ANOVA.

RESULTS

All methods successfully separated CD9+ and CD63+ EVs from saliva. The UC + PS and PBP + UC protocols yielded the highest concentrations of EVs, enriched in < 200 nm vesicles. EV purity and RNA recovery were comparable among all methods. Expression of miR-16, miR-27a, and miR-99a was successfully detected using all methods.

CONCLUSIONS

The UC + PS and PBP + UC protocols demonstrate comparable efficiency in separating salivary EVs. However, the combined PBP + UC protocol, with its simplified processing capability, offers a significant advantage, particularly in the initial phase of EV separation. This finding suggests its potential application in clinical settings where time-sensitive simple processing is critical. Further validation is needed to confirm its effectiveness for transcriptomic and proteomic analyses.

Extracellular vesicles from cartilage progenitors stimulate type II collagen expression and wound healing in meniscal cells

Knee meniscus tearing is a common orthopaedic injury that can heal poorly if left untreated, increasing the risk of post-traumatic Osteoarthritis. Intraarticular injection of human cartilage-derived progenitor cells (CPCs) has been shown to promote meniscus healing after injury. However, the mechanism by which CPCs stimulated this effect was unclear. The purpose of this study was to determine the paracrine effects that CPC-derived extracellular vesicles (EVs) have on native meniscal cells during healing. EVs from human CPCs and marrow-derived stromal cells were isolated via ultracentrifugation. EVs produced by each cell type were quantified, and their sizes were determined via NanoSight. EV protein expression was characterized via western blot. Meniscal fibrochondrocyte cellular metabolic activity (as an indicator of cell viability and proliferation) following treatment with EVs, was quantified using MTT and ATP assays. A 2D wound healing assay was used to determine the effects of treating inner meniscal fibrochondrocytes with EVs in a dose-dependent manner. Gene expression analysis for chondrogenesis genes was performed via RT-qPCR on inner meniscal fibrochondrocytes following treatment with EVs. Our results showed that CPCs produced a wide size range of EVs expressing CD9, CD81, and HSP70. Treatment of inner meniscal fibrochondrocytes with CPC-EVs improved 2D wound healing, in comparison to EVs isolated from marrow-derived stromal cell controls. CPC-EV treatment increased Type II Collagen mRNA expression in inner meniscal fibrochondrocytes. These findings demonstrate that CPC-EVs stimulate chondrogenic matrix production and wound healing in meniscal cells at the optimal dose of 1.0 × 107 particles/mL, significantly outperforming the effects of marrow stromal cell-derived EVs.

Tetraspanin CD9 alters cellular trafficking and endocytosis of tetraspanin CD63, affecting CD63 packaging into small extracellular vesicles

Small extracellular vesicles (sEVs) are particles secreted from cells that play vital roles both in normal physiology and in human disease. sEVs are highly enriched in tetraspanin proteins, such as CD9 and CD63, and contain tetraspanin-enriched membrane microdomains involved in loading of sEVs with macromolecule cargoes and in sEV biogenesis. However, the precise roles of individual tetraspanins in sEV biogenesis and cargo loading remain poorly understood. Here, we report that CD9 negatively regulated CD63 trafficking to tetraspanin-enriched microdomains and its subsequent packaging into sEVs, whereas CD63 had no discernable effect on CD9 localization or packaging. Using super resolution microscopy of individual vesicles, we showed that CD9 governs the fraction of sEVs that are loaded with CD63. Interestingly, CD9-dependent suppression of CD63 packaging was rescued by pharmacological blockade of endocytosis. Together, our data support a model where CD9 contributes to the regulation and secretion of CD63 in an endocytosis-dependent manner to reprogram the contents of sEVs and tetraspanin-enriched microdomains.

Glycosylation on extracellular vesicles and its detection strategy: Paving the way for clinical use

Extracellular vesicles (EVs) contain various glycans during their life cycle, from biogenesis to cellular recognition and uptake by recipient cells. EV glycosylation has substantial diagnostic significance in multiple health conditions, highlighting the necessity of determining an accurate glycosylation pattern for EVs from diverse biological fluids. Reliable and accessible glycan detection techniques help to elaborate the glycosylation-related functional alterations of specific proteins or lipids. However, multiple obstacles exist, including the inconsistency in glycosylation patterns between an entire batch of EVs and a specific EV protein, and difficulty in distinguishing glycosylation types after tedious separation and purification procedures. This review outlines recent advances in EV glycan detection, either at the glycomic level for a collection of intact EVs or at the molecular level for a specific protein on EVs. Particular emphasis has been placed on the abundance of EVs in body fluids and their unique characteristics for drug delivery of EVs, indicating an opportunity for diagnostic and therapeutic purposes via EV glycans.

Mesenchymal Stem Cell Exosome and Fibrin Sealant Composite Enhances Rabbit Anterior Cruciate Ligament Repair

BACKGROUND

The anterior cruciate ligament (ACL) fails to heal after rupture, leading to joint instability and an increased risk of osteoarthritis. Mesenchymal stem/stromal cell (MSC) exosomes have reported wide-ranging therapeutic efficacy; however, their potential for augmenting ACL repair remains to be investigated.

PURPOSE

To evaluate the use of MSC exosomes with fibrin sealant on biological augmentation of ACL healing after suture repair and their effects on ACL fibroblast functions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve rabbit knees underwent ACL transection and suture repair. MSC exosome and fibrin composite (Exosome+Fibrin) or fibrin (Fibrin) alone was used to supplement the suture repair in 6 knees. ACL repair was assessed by magnetic resonance imaging at 6 and 12 weeks postoperatively and by histologic and immunohistochemical analyses at 12 weeks. To investigate the mechanisms through which MSC exosomes augment ACL repair, metabolic activity, proliferation, migration, and matrix synthesis assays were performed using the primary ACL fibroblasts. RNA sequencing was also performed to assess global gene expression changes in exosome-treated ACL fibroblasts.

RESULTS

Based on magnetic resonance imaging findings, 5 of 6 Exosome+Fibrin-treated ACLs were completely or partially healed, as opposed to 5 of 6 Fibrin-treated ACLs appearing torn at 6 and 12 weeks postoperatively. Additionally, 4 of 6 Exosome+Fibrin-treated ACLs were isointense, as compared with 5 of 6 Fibrin-treated ACLs that were hyperintense, indicating improved remodeling and maturation of the repaired ACLs with Exosome+Fibrin treatment. Histologically, Exosome+Fibrin-treated ACLs showed more organized collagen fibers and abundant collagen deposition, with a high amount of collagen I and relatively lower amount of collagen III, which are consistent with the matrix structure and composition of the normal ACL. Cell culture studies using ACL fibroblasts showed that MSC exosomes enhanced proliferation, migration, and collagen synthesis and deposition, which are cellular processes relevant to ACL repair. Further gene set enrichment analysis revealed key pathways mediated by MSC exosomes in enhancing proliferation and migration while reducing matrix degradation of ACL fibroblasts.

CONCLUSION

The combination of MSC exosomes and fibrin sealant (Exosome+Fibrin) applied to a suture repair enhanced the morphologic and histologic properties of the ACL in a rabbit model, and these improvements could be attributed to the augmented functions of ACL fibroblasts with exosome treatment.

CLINICAL RELEVANCE

This work supports the use of MSC exosomes in biological augmentation of ACL healing after suture repair.

Comparison of the procoagulant activity between extracellular vesicles obtained from cellular monolayers and spheroids

Tissue factor (TF) is the main activator of blood coagulation and is associated with thrombosis and tumor progression. It can be released into the blood circulation incorporated within cancer cell-derived extracellular vesicles (EVs). In this study, we investigated the influence of two-dimensional (monolayer) and three-dimensional (spheroid) tumor cell culture methods, and co-culture with cancer-associated fibroblasts (CAF), on the level of EVs release and the associated TF release and activity. The density of EVs and TF released from spheroids and monolayers of Hs578t human breast cancer and CAF were measured by the concentration of the phosphatidylserine and TF-ELISA. For some experiments, cells were activated using a protease-activated receptor (PAR)-2-activating peptide (PAR2-AP). The concentration and EV's size were accessed by nanoparticle tracking analysis, and a clotting assay was used to evaluate TF pro-coagulant activity. Hs578t monolayers released sevenfold more EVs, and it was associated with an 11-fold higher TF antigen release than the spheroids cultures. Activation of the cells with a PAR2-AP resulted in a significant increase in the release of EVs and TF from the Hs578t monolayers, but no significant increase was observed in the spheroids, only from half Hs578t, half CAF spheroids. Taken together, our results demonstrate that monolayer cell cultures are capable of releasing more significant amounts of EVs and associated TF than spheroid cultures. Monolayers and spheroids have different behavior when we compare the release of EVs and TF. It is essential to consider it when choosing a cell model to study cancer-associated thrombosis.

Prospects of bovine milk small extracellular vesicles in veterinary medicine

Extracellular vesicles (EV), including exosomes or small EV (sEV) derived from biological fluids, such as milk, have garnered increasing interest in veterinary medicine because of their role in the pathophysiology and understanding of the disease status of the host. Bovine milk serves as a rich source of sEV, containing diverse cargoes of nucleic acids, proteins, and lipids, which play a critical role in intercellular communication and regulation of host status. Although it is more difficult to isolate and purify sEV from bovine milk than from human breast milk, challenges persist in enabling the enrichment and analysis of sEV populations, facilitating the elucidation of their functional roles and prognostic potential in cattle diseases. Moreover, owing to their availability, ease of collection, noninvasive nature, and low cost, bovine milk sEV could be an excellent resource for research in veterinary medicine. Furthermore, the development of sEV-based prognosis is promising for improving veterinary medicine through the early detection of diseases and personalized therapeutic strategies. In this review, we provide a comprehensive overview of bovine milk sEV related to disease monitoring, host physiology, and immune regulation, and highlight their potential applications in advancing veterinary medicine. The prognostic and therapeutic potential of bovine milk sEV could be unlocked by combining knowledge from many fields, creating new opportunities for the development of precise, early prognostic, and focused therapeutic interventions for diseases in veterinary medicine.

Comparative effects of various extracellular vesicle subpopulations derived from clonal mesenchymal stromal cells on cultured fibroblasts in wound healing-related process

INTRODUCTION

Non-healing wounds pose significant challenges and require effective therapeutic interventions. Extracellular vesicles (EVs) have emerged as promising cell-free therapeutic agents in tissue regeneration. However, the functional differences between different subpopulations of EVs in wound healing remain understudied. This study aimed to evaluate the effects of two distinct subpopulations of clonal mesenchymal stromal cells (cMSC)-derived EVs (cMSC-EVs), namely 20 K and 110K-cMSC-EVs, primarily on in vitro wound healing process, providing fast and cost-effective alternatives to animal models.

METHODS

In vitro assays were conducted to compare the effects of 20 K and 110K-cMSC-EVs, isolated through high-speed centrifugation and differential ultracentrifugation, respectively. For evaluation the main mechanisms of wound healing, including cell proliferation, cell migration, angiogenesis, and contraction. Human dermal fibroblasts (HDF) were considered as the main cells for analysis of these procedures. Moreover, gene expression analysis was performed to assess the impact of these EV subpopulations on the related process of wound healing on HDF.

RESULTS

The results demonstrated that both 20 K and 110K-cMSC-EVs exhibited beneficial effects on cell proliferation, cell migration, angiogenesis, and gel contraction. RT-qPCR revealed that both EV types downregulated interleukin 6 (IL6), induced proliferation by upregulating proliferating cell nuclear antigen (PCNA), and regulated remodeling by upregulating matrix metallopeptidase 1 (MMP1) and downregulating collagen type 1 (COL1).

DISCUSSION

This study highlights the effects of both 20 K and 110K-cMSC-EVs on the potency of HDFs in wound healing-related process. As the notable finding, 20K-cMSC-EVs offer a more feasible and cost-effective subpopulation for isolation and follow the GMP standard, recommended to utilize this fraction for therapeutic application.

Lack of cellular prion protein causes Amyloid β accumulation, increased extracellular vesicle abundance, and changes to exosome biogenesis proteins

Alzheimer's disease (AD) progression is closely linked to the propagation of pathological Amyloid β (Aβ), a process increasingly understood to involve extracellular vesicles (EVs), namely exosomes. The specifics of Aβ packaging into exosomes remain elusive, although evidence suggests an ESCRT (Endosomal Sorting Complex Required for Transport)-independent origin to be responsible in spreading of AD pathogenesis. Intriguingly, PrPC, known to influence exosome abundance and bind oligomeric Aβ (oAβ), can be released in exosomes via both ESCRT-dependent and ESCRT-independent pathways, raising questions about its role in oAβ trafficking. Thus, we quantified Aβ levels within EVs, cell medium, and intracellularly, alongside exosome biogenesis-related proteins, following deletion or overexpression of PrPC. The same parameters were also evaluated in the presence of specific exosome inhibitors, namely Manumycin A and GW4869. Our results revealed that deletion of PrPC increases intracellular Aβ accumulation and amplifies EV abundance, alongside significant changes in cellular levels of exosome biogenesis-related proteins Vps25, Chmp2a, and Rab31. In contrast, cellular expression of PrPC did not alter exosomal Aβ levels. This highlights PrPC's influence on exosome biogenesis, albeit not in direct Aβ packaging. Additionally, our data confirm the ESCRT-independent exosome release of Aβ and we show a direct reduction in Chmp2a levels upon oAβ challenge. Furthermore, inhibition of opposite exosome biogenesis pathway resulted in opposite cellular PrPC levels. In conclusion, our findings highlight the intricate relationship between PrPC, exosome biogenesis, and Aβ release. Specifically, they underscore PrPC's critical role in modulating exosome-associated proteins, EV abundance, and cellular Aβ levels, thereby reinforcing its involvement in AD pathogenesis.

Downregulation of Tumor Suppressor Gene LKB1 During Severe Primary Graft Dysfunction After Human Lung Transplantation: Implication for the Development of Chronic Lung Allograft Dysfunction

BACKGROUND

Severe primary graft dysfunction (PGD) after lung transplantation (LTx) is a significant risk factor for the development of bronchiolitis obliterans syndrome (BOS). Recent data from our group demonstrated that small extracellular vesicles (sEVs) isolated from the plasma of LTx recipients with BOS have reduced levels of tumor suppressor gene liver kinase B1 ( LKB1 ) and promote epithelial-to-mesenchymal transition (EMT) and fibrosis. Here, we hypothesized that early inflammatory responses associated with severe PGD (PGD2/3) can downregulate LKB1 levels in sEVs, predisposing to the development of chronic lung allograft dysfunction (CLAD).

METHODS

sEVs were isolated from the plasma of human participants by Exosome Isolation Kit followed by 0.20-µm filtration and characterized by NanoSight and immunoblotting analysis. Lung self-antigens (K alpha 1 tubulin, Collagen V), LKB1 , nuclear factor kappa B, and EMT markers in sEVs were compared by densitometry analysis between PGD2/3 and no-PGD participants. Neutrophil-derived factors and hypoxia/reperfusion effects on LKB1 levels and EMT were analyzed in vitro using quantitative real-time polymerase chain reaction and Western blotting.

RESULTS

LKB1 was significantly downregulated in PGD2/3 sEVs compared with no-PGD sEVs. Within PGD2/3 participants, lower post-LTx LKB1 was associated with CLAD development. Hypoxia/reperfusion downregulates LKB1 and is associated with markers of EMT in vitro. Finally, lower LKB1 levels in PGD2/3 are associated with increased markers of EMT.

CONCLUSIONS

Our results suggest that in post-LTx recipients with PGD2/3, downregulation of LKB1 protein levels in sEVs is associated with increased EMT markers and may result in the development of CLAD. Our results also suggest that ischemia/reperfusion injury during LTx may promote CLAD through the early downregulation of LKB1 .

Integrin beta 1 and fibronectin mediate extracellular vesicle uptake and functional RNA delivery

Extracellular vesicles (EVs) are cell-derived vesicles secreted by all cell types into the extracellular spaces. EVs comprise a heterogenous population of vesicles that carry bioactive molecules, such as proteins, lipids, and RNAs, which they can deliver to recipient cells. Over the past few years, EVs have been recognized for their vital role in intercellular communication, and thereby in various physiological and pathological processes. In addition, EVs are increasingly being studied as potential drug delivery vehicles. It is therefore crucial to understand the mechanisms and molecular players underlying EV uptake and functional cargo delivery. Several studies have investigated various EV uptake pathways; nonetheless, molecular mechanisms governing uptake and cargo transfer remain largely lacking. Here, we show, using a CRISPR/Cas9-mediated reporter system, that integrin β1 on recipient cells plays an important role in EV uptake and EV-mediated RNA delivery. Additionally, using both RNA interference and blocking antibodies, we show that association of integrin β1 with integrin α4 is essential for this process. We demonstrate that α4β1 on recipient cells interacts with EVs through surface localized fibronectin via binding to its leucine-aspartic acid-valine motif, and that blocking of this interaction reduces both EV uptake and RNA delivery. Thus, we identify a key mechanism in EV uptake and cargo delivery which could potentially facilitate research into EV biology and pave the way for the development of novel therapeutic approaches by targeting pathways that lead to functional cargo delivery.

Enhanced Small Extracellular Vesicle Uptake by Activated Interneurons Improves Stroke Recovery in Mice

Neuronal circuitry remodelling, which comprises excitatory and inhibitory neurons, is critical for improving neurological outcomes after a stroke. Preclinical studies have shown that small extracellular vesicles (sEVs) have a therapeutic effect on stroke recovery. However, it is highly challenging to use sEVs to specifically target individual neuronal populations to enhance neuronal circuitry remodelling after stroke. In the present study, using a chemogenetic approach to specifically activate peri-infarct cortical interneurons in combination with the administration of sEVs derived from cerebral endothelial cells (CEC-sEVs), we showed that the CEC-sEVs were preferentially taken up by the activated neurons, leading to significant improvement of functional outcome after stroke, which was associated with augmentation of peri-infarct cortical axonal/dendritic outgrowth and of axonal remodelling of the corticospinal tract. The ultrastructural and Western blot analyses revealed that neurons with internalization of CEC-sEVs exhibited significantly reduced numbers of damaged mitochondria and proteins that mediate dysfunctional mitochondria, respectively. Together, these data indicate that the augmented uptake of CEC-sEVs by activated peri-infarct cortical interneurons facilitates neuronal circuitry remodelling and functional recovery after stroke, which has the potential to be a novel therapy for improving stroke recovery.

Plant-derived nanovesicles: Promising therapeutics and drug delivery nanoplatforms for brain disorders

Plant-derived nanovesicles (PDNVs), including plant extracellular vesicles (EVs) and plant exosome-like nanovesicles (ELNs), are natural nano-sized membranous vesicles containing bioactive molecules. PDNVs consist of a bilayer of lipids that can effectively encapsulate hydrophilic and lipophilic drugs, improving drug stability and solubility as well as providing increased bioavailability, reduced systemic toxicity, and enhanced target accumulation. Bioengineering strategies can also be exploited to modify the PDNVs to achieve precise targeting, controlled drug release, and massive production. Meanwhile, they are capable of crossing the blood-brain barrier (BBB) to transport the cargo to the lesion sites without harboring human pathogens, making them excellent therapeutic agents and drug delivery nanoplatform candidates for brain diseases. Herein, this article provides an initial exposition on the fundamental characteristics of PDNVs, including biogenesis, uptake process, isolation, purification, characterization methods, and source. Additionally, it sheds light on the investigation of PDNVs' utilization in brain diseases while also presenting novel perspectives on the obstacles and clinical advancements associated with PDNVs.

Extracellular Vesicles From Follicular Fluid in Infertile Women: Size, Morphology and miRNA Content Analysis

The declining birth rates and fertility challenges in Europe have intensified global concerns over rising infertility, particularly among women. This study decisively investigates follicular fluid-related extracellular vesicles (FF-EVs) from infertile patients with polycystic ovary syndrome (PCOS) or diminished ovarian reserve (DOR) undergoing in vitro fertilization (IVF), comparing them to a healthy control group. We have identified significant variations in protein content and polydispersity in crude follicular fluid using UV-Vis absorption and dynamic light scattering (DLS) techniques. Furthermore, the morphology of the extracellular vesicles (EVs) and the patterns of non-coding RNA content, including miRNAs, reveal distinct differences in infertile patients. These findings offer critical insights into the molecular signatures associated with these conditions. This study plays a vital role in advancing reproductive healthcare by pinpointing potential targets that can enhance diagnosis and deepen our understanding of ovarian disorders.

Extracellular vesicles from pancreatic cancer and its tumour microenvironment promote increased Schwann cell migration

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) exhibits a high frequency of neural invasion (NI). Schwann cells (SCs) have been shown to be reprogrammed to facilitate cancer cell migration and invasion into nerves. Since extracellular vesicles (EVs) affect the tumour microenvironment and promote metastasis, the present study analysed the involvement of EVs from pancreatic cancer cells and their microenvironment in altering SC phenotype as part of the early events in the process of NI.

METHODS

EVs were isolated from human/murine PDAC cells, pancreatic stellate cells (PSCs), human tissues and plasma to perform a novel 3D migration assay, qRT-PCR and western blot. Kaplan-Meier and Cox regression analyses were employed to evaluate the clinical potential of plasma EV-derived candidate from 165 PDAC patients.

RESULTS

The EVs from PDAC cells, PSCs derived from human tumour tissues, other cell types in the tumour microenvironment from tumour tissues and circulating plasma act as drivers of a pro-migratory phenotype of SCs by inducing dedifferentiation in SCs. Notably, p75NTR expression was upregulated in the plasma-derived EVs from patients with NI (Pn1) relative to those without NI (Pn0). High expression of plasma-derived EV p75NTR correlated with reduced overall survival and was identified as an independent prognostic factor.

CONCLUSIONS

These findings suggest that EV-mediated SC migration underlies the interactions contributing to PDAC-associated NI with implications for improved outcome and therapeutic strategy.

Human Transmembrane Serine Protease 2 (TMPRSS2) on Human Seminal Fluid Extracellular Vesicles Is Proteolytically Active

Human transmembrane serine protease 2 (TMPRSS2) has garnered substantial interest due to its clinical significance in various pathologies, notably its pivotal role in viral entry into host cells. The development of effective strategies to target TMPRSS2 is a current area of intense research and necessitates a consistent source of active TMPRSS2 with sufficient stability. Here, we comprehensively characterised human seminal-fluid extracellular vesicles (SF-EVs, also referred to as prostasomes), bearing a native source of surface-exposed, enzymatically active TMPRSS2 as demonstrated by high-sensitivity flow cytometry and a fluorometric activity assay. Additionally, we recombinantly produced human TMPRSS2 ectodomain in mammalian cells adopting a directed activation strategy. We observed comparable catalytic parameters and inhibition characteristics for both native SF-EV-associated and recombinant TMPRSS2 when exposed to serine protease inhibitor Nafamostat mesylate. Leveraging these findings, we developed a robust in vitro biochemical assay based on these SF-EVs for the screening of TMPRSS2-targeting compounds. Our results will accelerate the discovery and advancement of efficacious therapeutic approaches targeting TMPRSS2 and propel further exploration into the biological role of SF-EV-associated active TMPRSS2.

Potential Role of Menstrual Fluid-Derived Small Extracellular Vesicle Proteins in Endometriosis Pathogenesiss

Endometriosis, a chronic debilitating disease affects 1 in 7-10 girls and women, who have symptoms of severe chronic pain and subfertility and significantly impacts the overall quality of life. Currently, no effective early diagnostic methods are available for early stages of endometriosis. We used menstrual fluid-derived small extracellular vesicles (MF-sEVs) from women with self-reported endometriosis (laparoscopically diagnosed, n = 8) and self-reported without endometriosis and no painful periods (n = 9). MF-sEVs were separated using differential ultracentrifugation and characterised using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), Western Blot, flow cytometry, mass-proteomics analysis and functional assays. Spherical-shaped sEVs were identified with a median diameter of ∼120 nm, expressing sEV marker proteins. The MF-sEV proteins were classified as endometrial origin. Over 5000 proteins were identified, ∼77% of which were decreased whilst only 22 proteins (largely comprising immunoglobulins) were increased in endometriosis/MF-sEVs compared to control/MF-sEVs. Decreased proteins were involved in nitrogen compound metabolism, immune response, intracellular signal transduction, regulation of programmed cell death, maintenance of cell polarity and actin cytoskeleton organisation. Flow cytometry demonstrated a significant increase in CD86 expression (immune activation marker) in endometriosis/MF-sEVs. Mesothelial cells showed a significant decrease in cellular resistance and junctional protein expression. MF-sEVs are possible contributors to the pathogenesis of endometriosis and may have the potential for early detection of the disease.

Hypoxia regulates small extracellular vesicle biogenesis and cargo sorting through HIF-1α/HRS signaling pathway in head and neck squamous cell carcinoma

Small extracellular vesicles (sEVs) act as crucial messengers that transmit biological signals in hypoxic tumor microenvironment (TME), significantly impacting cancer progression. However, the precise mechanism by which hypoxia influences sEV biogenesis remains poorly understood. In this study, we observed increased sEV secretion and alterations in cargo composition in head and neck squamous cell carcinoma (HNSCC) cells under hypoxic conditions. We found that hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), a key component of the endosomal sorting complexes required for transport (ESCRT), was upregulated during hypoxia. This upregulation activated the endosomal system and reduced degradation of multivesicular bodies (MVBs). HRS depletion altered the packaging of protein cargoes such as mitochondria-related proteins into sEVs under hypoxia, and these cargoes promoted a pro-tumorigenic phenotype of macrophages. Importantly, we demonstrated that HRS is transcriptionally activated by hypoxia inducible factor-1α (HIF-1α). Spatial transcriptomics and immunohistochemistry revealed a positive correlation between HRS and HIF-1α. These findings establish a link between the hypoxic response, sEV biogenesis, and cargo packaging, enhancing our understanding of how the hypoxic TME influences sEV biogenesis in HNSCC cells.

Rapid and high-sensitivity screening of pregnancy complications by profiling circulating placental extracellular vesicles

Herein, we developed a specific, rapid sensor to quantify placental extracellular vesicle (EV) protein biomarkers of early pregnancy complications. A distinct tetraspanin CD9 and placental alkaline phosphatase (PLAP) expression pattern was observed via targeted multiple reaction monitoring of EVs from maternal plasma collected before 18 weeks of gestation. A classification model was developed using training and validation patient sets, distinguishing between individuals at high risk of developing complications from those with normal pregnancies, achieving 80% sensitivity, 90% specificity, 89% positive predictive value (PPV), and 82% negative predictive value (NPV). Superparamagnetic nanoflowers that captured target EVs (CD9+/PLAP+) were used to construct a 4-flex glass strip nanozymatic readout system. The sensor analyzes plasma for EVs, identifying gestational diabetes mellitus risk with a 95% combined sensitivity, 100% specificity, 100% PPV, and 96% NPV. This nanoplatform identifies individuals at risk of developing pregnancy complications with a >90% classification accuracy, exhibiting potential for clinical applications.

Embryo-Induced Changes in the Protein Profile of Bovine Oviductal Extracellular Vesicles

The study of early maternal-embryonic cross-talk remains one of the most challenging topics in reproductive biology. Understanding the physiological mechanisms involved in the interactions between the maternal reproductive tract and the developing embryo is essential for enhancing bovine reproductive efficiency. This complex communication starts within the oviduct, where the modulation of biological processes important for ensuring embryo quality is partially facilitated through extracellular vesicles (EVs). Utilizing a combination of in vivo and in vitro models this study had three main objectives: 1) to examine the protein cargo of EVs isolated from the oviductal fluid (OF) of cyclic and pregnant heifers to understand their role in maternal-embryonic communication in vivo; 2) to characterize the protein profile of EVs in conditioned medium (CM) resulting from the culture of oviductal explants alone (Exp) or in the presence of 8- to 16-cell stage embryos (Exp + Emb); and 3) to compare the protein cargo of EVs from Exp with EVs from cyclic heifers and EVs from Exp + Emb with EVs from pregnant heifers. Proteins were considered "identified" if detected in at least three out of five replicates and considered "exclusive" if detected in at least three out of five replicates within one group but absent in all samples of other groups. We identified 659 and 1476 proteins in the OF-EVs of cyclic and pregnant heifers, respectively. Among these, 644 proteins were identified in OF-EVs from both cyclic and pregnant heifers, and 40 proteins were exclusive to OF-EVs from the pregnant group. Within the 644 proteins identified in both groups, 31 were identified as differently abundant proteins (DAPs). In pregnant heifers, DAPs were mainly related to genome activation, DNA repair, embryonic cell differentiation, migration, and immune tolerance. In vitro, we identified 841 proteins in the CM-EVs from Exp alone, 613 from Exp + Emb, and 111 in the CM-EVs from Emb alone. In the qualitative analysis between the three in vitro groups, 81 proteins were identified in all groups, 452 were common to Exp and Exp + Emb, 17 were common to Exp and Emb, 5 were common to Exp + Emb and Emb, 4 were unique to Exp, 6 were unique to Exp + Emb, and none were unique to Emb. Proteins identified when there is an interaction between the oviduct and the embryo in vitro, corresponding to the Exp + Emb group, were associated with immune tolerance, structural activity, binding, and cytoskeletal regulation. In vivo and in vitro EVs exhibit distinct qualitative and quantitative protein contents, both when comparing EVs produced in the absence of an embryo (Cyclic and Exp) and those that have undergone embryo-oviduct interaction (Pregnant and Exp + Emb). The observed changes in the protein cargo of EVs due to maternal-embryonic communication in vivo and in vitro suggest that the interaction between the embryo and the maternal milieu initiates within the oviduct and is potentially facilitated by EVs and their protein contents.

Leveraging nature's nanocarriers: Translating insights from extracellular vesicles to biomimetic synthetic vesicles for biomedical applications

Naturally occurring extracellular vesicles (EVs) and synthetic nanoparticles like liposomes have revolutionized precision diagnostics and medicine. EVs excel in biocompatibility and cell targeting, while liposomes offer enhanced drug loading capacity and scalability. The clinical translation of EVs is hindered by challenges including low yield and heterogeneity, whereas liposomes face rapid immune clearance and limited targeting efficiency. To bridge these gaps, biomimetic synthetic vesicles (SVs) have emerged as innovative platforms, combining the advantageous properties of EVs and liposomes. This review emphasizes critical aspects of EV biology, such as mechanisms of EV-cell interaction and source-dependent functionalities in targeting, immune modulation, and tissue regeneration, informing biomimetic SV engineering. We reviewed a broad array of biomimetic SVs, with a focus on lipid bilayered vesicles functionalized with proteins. These include cell-derived nanovesicles, protein-functionalized liposomes, and hybrid vesicles. By addressing current challenges and highlighting opportunities, this review aims to advance biomimetic SVs for transformative biomedical applications.

Plasma Extracellular Vesicle-derived MicroRNA Associated with Human Alpha-1 Antitrypsin Deficiency-mediated Liver Disease

Background and Aims

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder associated with liver disease, ranging from fibrosis to hepatocellular carcinoma. The disease remains asymptomatic until its final stages when liver transplantation is the only available therapy. Biomarkers offer an advantage for disease evaluation. The presence of microRNAs (miRNAs) in plasma extracellular vesicles (EVs) presents a noninvasive approach to assess the molecular signatures of the disease. In this study, we aimed to identify miRNA biomarkers to distinguish molecular signatures of the liver disease associated with AATD in AATD individuals.

Methods

Using small RNA sequencing and qPCR, we examined plasma EV miRNAs in healthy controls (n = 20) and AATD patients (n = 17). We compared the EV miRNAs of AATD individuals with and without liver disease, developing an approach for detecting liver disease. A set of miRNAs identified in the AATD testing cohort was validated in a separate cohort of AATD patients (n = 45).

Results

We identified differential expression of 178 EV miRNAs in the plasma of the AATD testing cohort compared to controls. We categorized AATD individuals into those with and without liver disease, identifying 39 differentially expressed miRNAs. Six miRNAs were selected to test their ability to discriminate liver disease in AATD. These were validated for their specificity and sensitivity in an independent cohort of 45 AATD individuals. Our logistic model established composite scores with three- and four-miRNA combinations, achieving areas under the curve of 0.737 and 0.751, respectively, for predicting AATD liver disease.

Conclusions

We introduce plasma EV-derived miRNAs as potential biomarkers for evaluating AATD liver disease. Plasma EV-associated miRNAs may represent a molecular signature of AATD liver disease and could serve as valuable tools for its detection and monitoring.

Mesenchymal Stem Cell Secretome: Potential Applications in Human Infertility Caused by Hormonal Imbalance, External Damage, or Immune Factors

Mesenchymal stem cells (MSCs) are a source of a wide range of soluble factors, including different proteins, growth factors, cytokines, chemokines, and DNA and RNA molecules, in addition to numerous secondary metabolites and byproducts of their metabolism. MSC secretome can be formally divided into secretory and vesicular parts, both of which are very important for intercellular communication and are involved in processes such as angiogenesis, proliferation, and immunomodulation. Exosomes are thought to have the same content and function as the MSCs from which they are derived, but they also have a number of advantages over stem cells, including low immunogenicity, unaltered functional activity during freezing and thawing, and a lack of tumor formation. In addition, MSC pre-treatment with various inflammatory factors or hypoxia can alter their secretomes so that it can be modified into a more effective treatment. Paracrine factors secreted by MSCs improve the survival of other cell populations by several mechanisms, including immunomodulatory (mostly anti-inflammatory) activity and anti-apoptotic activity partly based on Hsp27 upregulation. Reproductive medicine is one of the fields in which this cell-free approach has been extensively researched. This review presents the possible applications and challenges of using MSC secretome in the treatment of infertility. MSCs and their secretions have been shown to have beneficial effects in various models of female and male infertility resulting from toxic damage, endocrine disorders, trauma, infectious agents, and autoimmune origin.

Prospect of extracellular vesicles in tumor immunotherapy

Extracellular vesicles (EVs), as cell-derived small vesicles, facilitate intercellular communication within the tumor microenvironment (TME) by transporting biomolecules. EVs from different sources have varied contents, demonstrating differentiated functions that can either promote or inhibit cancer progression. Thus, regulating the formation, secretion, and intake of EVs becomes a new strategy for cancer intervention. Advancements in EV isolation techniques have spurred interest in EV-based therapies, particularly for tumor immunotherapy. This review explores the multifaceted functions of EVs from various sources in tumor immunotherapy, highlighting their potential in cancer vaccines and adoptive cell therapy. Furthermore, we explore the potential of EVs as nanoparticle delivery systems in tumor immunotherapy. Finally, we discuss the current state of EVs in clinical settings and future directions, aiming to provide crucial information to advance the development and clinical application of EVs for cancer treatment.

Plasma extracellular vesicles from recurrent GBMs carrying LDHA to activate glioblastoma stemness by enhancing glycolysis

Rationale: Glioblastoma multiforme (GBM) is the most aggressive primary malignant brain tumor in adults, characterized by high invasiveness and poor prognosis. Glioma stem cells (GSCs) drive GBM treatment resistance and recurrence, however, the molecular mechanisms activating intracranial GSCs remain unclear. Extracellular vesicles (EVs) are crucial signaling mediators in regulating cell metabolism and can cross the blood-brain barrier (BBB). This study aimed to elucidate how EV cargo contributes to the intracranial GSC state and validate a non-invasive diagnostic strategy for GBM relapse. Methods: We isolated plasma extracellular vesicles (pl-EVs) from three groups: recurrent GBM patients post-resection, non-recurrent GBM patients post-resection, and healthy individuals. Newly diagnosed GBM patients served as an additional control. EVs were characterized and co-cultured with primary GBM cell lines to assess their effect on tumor stemness. EV cargo was analyzed using proteomics to investigate specific EV subpopulations contributing to GBM relapse. Based on these findings, we generated engineered LDHA-enriched EVs (LDHA-EVs) and co-cultured them with patient-derived organoids (PDOs). Metabolomics was performed to elucidate the underlying signal transduction pathways. Results: Our study demonstrated that pl-EVs from recurrent GBM patients enhanced aerobic glycolysis and stemness in GBM cells. Proteomic analysis revealed that plasma EVs from recurrent GBMs encapsulated considerable amounts of the enzyme lactate dehydrogenase A (LDHA). Mechanistically, LDHA-loaded EVs promoted glycolysis, induced cAMP/ATP cycling, and accelerated lactate production, thereby maintained the GSC phenotype. Concurrently, post-surgical therapy-induced stress-modulated hypoxia in residual tumors, promoted LDHA-enriched EV release. Clinically, high levels of circulating LDHA-positive EVs correlated with increased glycolysis, poor therapeutic response, and shorter survival in recurrent GBM patients. Conclusion: Our study highlights LDHA-loaded EVs as key mediators promoting GSC properties and metabolic reprogramming in GBM. These findings provide insights into recurrence mechanisms and suggest potential liquid biopsy approaches for monitoring and preventing GBM relapse.

Bone and muscle crosstalk in ageing and disease

Interorgan communication between bone and skeletal muscle is central to human health. A dysregulation of bone-muscle crosstalk is implicated in several age-related diseases. Ageing-associated changes in endocrine, inflammatory, nutritional and biomechanical stimuli can influence the differentiation capacity, function and survival of mesenchymal stem cells and bone-forming and muscle-forming cells. Consequently, the secretome phenotype of bone and muscle cells is altered, leading to impaired crosstalk and, ultimately, catabolism of both tissues. Adipose tissue acts as a third player in the bone-muscle interaction by secreting factors that affect bone and muscle cells. Physical exercise remains the key biological stimulus for bone-muscle crosstalk, either directly via the release of cytokines from bone, muscle or adipocytes, or indirectly through extracellular vesicles. Overall, bone-muscle crosstalk is considered an inherent process necessary to maintain the structure and function of both tissues across the life cycle. This Review summarizes the latest biomedical advances in bone-muscle crosstalk as it pertains to human ageing and disease. We also outline future research priorities to accommodate the understanding of this rapidly emerging field.

Isolating Astrocyte-Derived Extracellular Vesicles From Urine

Introduction

Brain-derived extracellular vesicles (BDEVs) can cross the blood-brain barrier and enter the periphery. Therefore, quantifying and analyzing peripherally circulating BDEVs offer a promising approach to directly obtain a window into central nervous system (CNS) pathobiology in vivo. Rapidly evolving CNS diseases require high-frequency sampling, but daily venipuncture of human subjects is highly invasive and usually unfeasible.

Methods

To address this challenge, here we present a novel method for isolating astrocyte-derived extracellular vesicles from urine (uADEVs), combining urine concentration, ultracentrifugation to isolate total EVs, and then glutamate-aspartate transporter (GLAST) EV isolation using an anti-GLAST antibody.

Results

The identity of these GLAST+EVs as uADEVs was confirmed by transmission electron microscopy, nanoparticle tracking analysis, western blotting, and assessment of astrocyte-related neurotrophins.

Conclusions

Leveraging the convenience and availability of urine samples, the non-invasive uADEV approach provides a novel tool that allows high-frequency sampling to investigate rapidly evolving CNS diseases.

The promise of mesenchymal stromal/stem cells in erectile dysfunction treatment: a review of current insights and future directions

Erectile dysfunction is a common and multifactorial condition that significantly impacts men's quality of life. Traditional treatments, such as phosphodiesterase type 5 inhibitors (PDE5i), often fail to provide lasting benefits, particularly in patients with underlying health conditions. In recent years, regenerative medicine, particularly stem cell therapies, has emerged as a promising alternative for managing erectile dysfunction. This review explores the potential of mesenchymal stromal/stem cells (MSCs) and their paracrine effects, including extracellular vesicles (EVs), in the treatment of erectile dysfunction. MSCs have shown remarkable potential in promoting tissue repair, reducing inflammation, and regenerating smooth muscle cells, offering therapeutic benefits in models of erectile dysfunction. Clinical trials have demonstrated positive outcomes in improving erectile function and other clinical parameters. This review highlights the promise of MSC therapy for erectile dysfunction, discusses existing challenges, and emphasizes the need for continued research to refine these therapies and improve long-term patient outcomes.

Flow virometry: recent advancements, best practices, and future frontiers

The imperative for developing robust tools to detect, analyze, and characterize viruses has become increasingly evident as they continue to threaten human health. In this review, we focus on recent advancements in studying human viruses with flow virometry (FV), an emerging technique that has gained considerable momentum over the past 5 years. These advancements include the application of FV in viral surface phenotyping, viral protein functionality, virus sorting, vaccine development, and diagnostics. With examples illustrated using primary data from our recent studies, we demonstrate that FV is a powerful yet underutilized methodology that, when employed with best practices and experimental rigor, can be highly valuable for studying individual virion heterogeneity, virus phenotypes, and virus-antibody interactions. In this review, we also address the current challenges when performing FV studies, propose strategies to overcome these obstacles, and outline best practices for both new and experienced researchers. Finally, we discuss the promising future prospects of FV within the broader context of virology research.

Extracellular vesicles as drug and gene delivery vehicles in central nervous system diseases

Extracellular vesicles (EVs) are secreted by almost all cell types and contain DNA, RNA, proteins, lipids and other metabolites. EVs were initially believed to be cellular waste but now recognized for their role in cell-to-cell communication. Later, EVs from immune cells were discovered to function similarly to their parent cells, paving the way for their use as gene and drug carriers. EVs from different cell types or biological fluids carry distinct cargo depending on their origin, and they perform diverse functions. For instance, EVs derived from stem cells possess pluripotent properties, reflecting the cargo from their parent cells. Over the past two decades, substantial preclinical and clinical research has explored EVs-mediated drug and gene delivery to various organs, including the brain. Natural or intrinsic EVs may be effective for certain applications, but as drug or gene carriers, they demonstrate broader and more efficient potential across various diseases. Here, we review research on using EVs to treat central nervous system (CNS) diseases, such as Alzheimer's Disease, Parkinson diseases, depression, anxiety, dementia, and acute ischemic strokes. We first reviewed the naïve EVs, especially mesenchymal stem cell (MSC) derived EVs in CNS diseases and summarized the clinical trials of EVs in treating CNS diseases and highlighted the reports of two complete trials. Then, we overviewed the preclinical research of EVs as drug and gene delivery vehicles in CNS disease models, including the most recent two years' progress and discussed the mechanisms and new methods of engineered EVs for targeting CNS. Finally, we discussed challenges and future directions and of EVs as personalized medicine for CNS diseases.

Consensus statement on extracellular vesicles in liquid biopsy for advancing laboratory medicine

Extracellular vesicles (EVs) represent a diverse class of nanoscale membrane vesicles actively released by cells. These EVs can be further subdivided into categories like exosomes and microvesicles, based on their origins, sizes, and physical attributes. Significantly, disease-derived EVs have been detected in virtually all types of body fluids, providing a comprehensive molecular profile of their cellular origins. As a result, EVs are emerging as a valuable addition to liquid biopsy techniques. In this collective statement, the authors share their current perspectives on EV-related research and product development, with a shared commitment to translating this newfound knowledge into clinical applications for cancer and other diseases, particularly as disease biomarkers. The consensus within this document revolves around the overarching recognition of the merits, unresolved questions, and existing challenges surrounding EVs. This consensus manuscript is a collaborative effort led by the Committee of Exosomes, Society of Tumor Markers, Chinese anti-Cancer Association, aimed at expediting the cultivation of robust scientific and clinically applicable breakthroughs and propelling the field forward with greater swiftness and efficacy.

Human spindle-shaped urine-derived stem cell exosomes alleviate severe fatty liver ischemia-reperfusion injury by inhibiting ferroptosis via GPX4

BACKGROUND

Severe hepatic steatosis can exacerbate Ischemia-reperfusion injury (IRI), potentially leading to early graft dysfunction and primary non-function. In this study, we investigated the heterogeneity of different subpopulations of Urine-derived stem cells (USCs) to explore the most suitable cell subtype for treating severe steatotic liver IRI.

METHODS

This study utilized scRNA-seq and Bulk RNA-seq to investigate the transcriptional heterogeneity between Spindle-shaped USCs (SS-USCs) and Rice-shaped USCs (RS-USCs). Additionally, rat fatty Liver transplantation (LT) model, mouse fatty liver IRI model, and Steatotic Hepatocyte Hypoxia-Reoxygenation (SHP-HR) model were constructed. Extracellular vesicles derived from SS-USCs and RS-USCs were isolated and subjected to mass spectrometry analysis. The therapeutic effects of Spindle-shaped USCs Exosomes (SS-USCs-Exo) and Rice-shaped USCs Exosomes (RS-USCs-Exo) were explored, elucidating their potential mechanisms in inhibiting ferroptosis and alleviating IRI.

RESULTS

Multiple omics analyses confirmed that SS-USCs possess strong tissue repair and antioxidant capabilities, while RS-USCs have the potential to differentiate towards specific directions such as the kidney, nervous system, and skeletal system, particularly showing great application potential in renal system reconstruction. Further experiments demonstrated in vivo and in vitro models confirming that SS-USCs and SS-USCs-Exo significantly inhibit ferroptosis and alleviate severe fatty liver IRI, whereas the effects of RS-USCs/RS-USCs-Exo are less pronounced. Analysis comparing the proteomic differences between SS-USCs-Exo and RS-USCs-Exo revealed that SS-USCs-Exo primarily inhibit ferroptosis and improve cellular viability by secreting exosomes containing Glutathione Peroxidase 4 (GPX4) protein. This highlights the most suitable cell subtype for treating severe fatty liver IRI.

CONCLUSIONS

SS-USCs possess strong tissue repair and antioxidant capabilities, primarily alleviating ferroptosis in the donor liver of fatty liver through the presence of GPX4 protein in their exosomes. This highlights SS-USCs as the most appropriate cell subtype for treating severe fatty liver IRI.

Mesenchymal stem cell exosome therapy: current research status in the treatment of neurodegenerative diseases and the possibility of reversing normal brain aging

With the exacerbation of the aging population trend, a series of neurodegenerative diseases caused by brain aging have become increasingly common, significantly impacting the daily lives of the elderly and imposing heavier burdens on nations and societies. Brain aging is a complex process involving multiple mechanisms, including oxidative stress, apoptosis of damaged neuronal cells, chronic inflammation, and mitochondrial dysfunction, and research into new therapeutic strategies to delay brain aging has gradually become a research focus in recent years. Mesenchymal stem cells (MSCs) have been widely used in cell therapy due to their functions such as antioxidative stress, anti-inflammation, and tissue regeneration. However, accompanying safety issues such as immune rejection, tumor development, and pulmonary embolism cannot be avoided. Studies have shown that using exosome derived from mesenchymal stem cells (MSC-Exo) for the treatment of neurodegenerative diseases is a safe and effective method. It not only has the therapeutic effects of stem cells but also avoids the risks associated with cell therapy. Therefore, exploring new therapeutic strategies to delay normal brain aging from the mechanism of MSC-Exo in the treatment of neurodegenerative diseases is feasible. This review summarizes the characteristics of MSC-Exo and their clinical progress in the treatment of neurodegenerative diseases, aiming to explore the possibility and potential mechanisms of MSC-Exo in reversing brain aging.

High throughput analysis of rare nanoparticles with deep-enhanced sensitivity via unsupervised denoising

The large-scale multiparametric analysis of individual nanoparticles is increasingly vital in the diverse fields of biology, medicine, and materials science. However, the current methods struggle with the tradeoff between measurement scalability and sensitivity, especially when identifying rare nanoparticles in heterogeneous mixtures. By developing and combining an unsupervised deep learning-based denoising method and an optofluidic device tuned for nanoparticle detection, we realize a nanoparticle analyzer that simultaneously achieves high scalability, throughput, and sensitivity levels; we name this approach "Deep Nanometry" (DNM). DNM detects polystyrene beads with a detection of limit of 30 nm at a throughput of over 100,000 events/second. The sensitive and scalable DNM directly detects rare target extracellular vesicles (EVs) in non-purified serum, making up as little as 0.002% of the 1,214,392 total particles. Moreover, DNM accurately and sufficiently counts diagnostic marker EVs present in only 0.93% and 0.17% of particle detections in sera of colorectal cancer patients and healthy controls, demonstrating its potential application to the early detection of colorectal cancer.

Autocrine small extracellular vesicles induce tubular phenotypic transformation in diabetic nephropathy via miR-21-5p

BACKGROUND

Diabetic nephropathy (DN) is one of the most common and serious microvascular complications associated with diabetes. DN is the leading contributor to the majority of cases of end-stage renal disease (ESRD). Small extracellular vesicles (sEVs) can transport various genetic materials to recipient cells. The objective of this study was to explore how sEVs released from HK-2 cells when stimulated by high glucose levels influence renal tubular phenotypic transformation through miR-21-5p.

METHODS

Both human and cell studies were utilized to explore the crosstalk between proximal renal tubules in DN. sEVs from plasma and cells were isolated using ultracentrifugation, and the differential expression of miR-21-5p in plasma sEVs from DN patients versus healthy controls was quantified using Quantitative Real-time PCR (RT-qPCR). A DN model was constructed by stimulating HK-2 cells with glucose. The expression of epithelial-mesenchymal transition (EMT) proteins in each cell group was analyzed by Western Blot (WB), while miR-21-5p levels in both cells and their sEVs were quantified using RT-qPCR. A stable transfected HK-2 cell line was constructed. The CCK8 assay, scratch assay, and WB were employed to detect EMT proteins, aiming to explore how autocrine sEVs affect tubular phenotypic transformation in diabetic nephropathy (DN).

RESULTS

The expression of miR-21-5p in plasma sEVs was significantly elevated in the DN group compared to the healthy control group. High glucose (HG) stimulation of HK-2 cells resulted in higher miR-21-5p expression in both cells and their sEVs, leading to enhanced proliferation, migration, and EMT capacities in these cells. Co-incubation of HK-2 cells with HG-sEVs significantly enhanced the proliferation, migration, and EMT capabilities of the recipient cells, but miR-21-5p knockdown reversed these effects.

CONCLUSION

These results indicate that high glucose stimulates HK-2 cells to secrete sEVs, which promote DN proliferation, migration, and EMT through miR-21-5p, thereby offering new insights into the treatment of DN.

The roles and therapeutic potential of exosomal non-coding RNAs in microglia-mediated intercellular communication

Exosomes, which are small extracellular vesicles (sEVs), serve as versatile regulators of intercellular communication in the progression of various diseases, including neurological disorders. Among the diverse array of cargo they carry, non-coding RNAs (ncRNAs) play key regulatory roles in various pathophysiological processes. Exosomal ncRNAs derived from distinct cells modulate their reciprocal crosstalk locally or remotely, thereby mediating neurological diseases. Nevertheless, the emerging role of exosomal ncRNAsin microglia-mediated phenotypes remains largely unexplored. This review aims to summarise the biological functions of exosomal ncRNAs and the molecular mechanisms that underlie their impact on microglia-mediated intercellular communication, modulating neuroinflammation and synaptic functions within the landscape of neurological disorders. Furthermore, this review comprehensively described the potential applications of exosomal ncRNAs as diagnostic and prognostic biomarkers, as well as innovative therapeutic targets for the treatment of neurological diseases.

Advances of exosomes in diabetic wound healing

Poor wound healing is a refractory process that places an enormous medical and financial burden on diabetic patients. Exosomes have recently been recognized as crucial players in the healing of diabetic lesions. They have excellent stability, homing effects, biocompatibility, and reduced immunogenicity as novel cell-free therapies. In addition to transporting cargos to target cells to enhance intercellular communication, exosomes are beneficial in nearly every phase of diabetic wound healing. They participate in modulating the inflammatory response, accelerating proliferation and reepithelization, increasing angiogenesis, and regulating extracellular matrix remodeling. Accumulating evidence indicates that hydrogels or dressings in conjunction with exosomes can prolong the duration of exosome residency in diabetic wounds. This review provides an overview of the mechanisms, delivery, clinical application, engineering, and existing challenges of the use of exosomes in diabetic wound repair. We also propose future directions for biomaterials incorporating exosomes: 2D or 3D scaffolds, biomaterials loaded with wound healing-promoting gases, intelligent biomaterials, and the prospect of systematic application of exosomes. These findings may might shed light on future treatments and enlighten some studies to improve quality of life among diabetes patients.

Role of Glycans in Equine Endometrial Cell Uptake of Extracellular Vesicles Derived from Amniotic Mesenchymal Stromal Cells

Extracellular vesicles (EVs) are important mediators of cell-cell communication thanks to their ability to transfer their bioactive cargo, thus regulating a variety of physiological contexts. EVs derived from amniotic mesenchymal/stromal cells (eAMC-EVs) are internalized by equine endometrial cells (eECs) with positive effects on regenerative medicine treatments. As the cellular uptake of EVs is influenced by the glycan profile of both EVs and target cells, this study is focused on the role of surface glycans in the uptake of eAMC-EVs by recipient eECs. Equine ECs were obtained by enzymatic digestion of uteri from healthy mares. Equine AMC-EVs were isolated from amniotic cell cultures according to a standardized protocol. The glycan pattern was studied using a panel of lectins in combination with fucosidase and neuraminidase treatment. Both eECs and eAMC-EVs expressed N-linked high mannose glycans, as well as fucosylated and sialylated glycans. All these glycans were involved in the uptake of eAMC-EVs by eECs. The internalization of eAMC-EVs was strongly reduced after cleavage of α1,2-linked fucose and α2,3/α2,6-linked sialic acids. These results demonstrate that surface glycans are involved in the internalization of eAMC-EVs by eECs and that fucosylated and sialylated glycans are highly relevant in the transfer of bioactive molecules with effects on regenerative medicine treatments.

The Proteome of Exosomes at Birth Predicts Insulin Resistance, Adrenarche and Liver Fat in Childhood

It is unknown whether there are differentially expressed proteins (DEPs) in the circulating exosomes of appropriate- vs. small-for-gestational-age (AGA vs. SGA) infants, and if so, whether such DEPs relate to measures of endocrine-metabolic health and body composition in childhood. Proteomic analysis in cord-blood-derived exosomes was performed by label-free quantitative mass spectrometry in AGA (n = 20) and SGA infants (n = 20) and 91 DEPs were identified. Enrichment analysis revealed that they were related to complement and coagulation cascades, lipid metabolism, neural development, PI3K/Akt and RAS/RAF/MAPK signaling pathways, phagocytosis and focal adhesion. Protein-protein interaction (PPI) analysis identified 39 DEPs involved in the pathways enriched by the KEGG and Reactome. Those DEPs were associated with measures of adiposity and insulin resistance and with liver fat at age 7 (all p < 0.01). Multivariate linear regression analysis uncovered that two DEPs (up-regulated in SGA), namely PCYOX1 (related to adipogenesis) and HSP90AA1 (related to lipid metabolism and metabolic-dysfunction-associated steatotic liver disease progression), were independent predictors of the hepatic fat fraction at age 7 (β = 0.634; p = 0.002; R2 = 52% and β = 0.436; p = 0.009; R2 = 24%, respectively). These data suggest that DEPs at birth may predict insulin resistance, adrenarche and/or ectopic adiposity in SGA children at age 7, when an early insulin-sensitizing intervention could be considered.

Levels of Proangiogenic Molecules and Terminal Complement Complex C5b-9 in the Crown of Circulating sEVs in Patients with Recurrent Glioblastomas: Relationship with Tumor Molecular Characteristics

Circulating small extracellular vesicles (sEVs) are emerging as potential biomarkers for glioblastoma progression. This study aimed to compare the levels of matrix metalloproteinases (MMP2 and MMP9), terminal complement complex (C5b-9), and VEGF-A in circulating sEVs in glioblastoma patients (GBMPs) with and without tumor recurrence. Using differential ultracentrifugation, sEVs were isolated from blood samples of GBMPs with no tumor recurrence for over one year (n = 6) and after first relapse (n = 14). The vesicles were characterized and quantified using flow cytometry. In both groups, C5b-9 was predominantly detected on tumor-specific circulating sEVs (glial fibrillary acidic protein (GFAP)-positive sEVs) with high VEGF-A expression, while C5b-9 was significantly less frequent on sEVs with low VEGF-A expression (p < 0.05). GFAP+VEGF+dimMMP2-C5b-9+ vesicles were rarely detected in GBMPs without relapse, suggesting their potential utility as biomarkers for a favorable relapse-free prognosis. In recurrent GBMPs, a positive correlation was observed between GFAP+VEGF+bright MMP2+C5b-9+ sEVs and MGMT gene promoter methylation levels (r = 0.543, p < 0.05). Additionally, a trend toward a negative correlation was found between GFAP+VEGF+bright MMP2+C5b-9- sEVs and mutant p53 expression in primary tumor tissue (r = -0.44, p = 0.114). These findings suggest that sEV profiles may serve as valuable prognostic markers for glioblastoma recurrence and treatment responses.

Regulatory Roles of Exosomes in Aging and Aging-Related Diseases

Exosomes are small vesicles with diameters ranging from 30 to 150 nm. They originate from cellular endocytic systems. These vesicles contain a rich payload of biomolecules, including proteins, nucleic acids, lipids, and metabolic products. Exosomes mediate intercellular communication and are key regulators of a diverse array of biological processes, such as oxidative stress and chronic inflammation. Furthermore, exosomes have been implicated in the pathogenesis of infectious diseases, autoimmune disorders, and cancer. Aging is closely associated with the onset and progression of numerous diseases and is significantly influenced by exosomes. Recent studies have consistently highlighted the important functions of exosomes in the regulation of cellular senescence. Additionally, research has explored their potential to delay aging, such as the alleviatory effects of stem cell-derived exosomes on the aging process, which offers broad potential for the development and application of exosomes as anti-aging therapeutic strategies. This review aims to comprehensively investigate the multifaceted impact of exosomes while concurrently evaluating their potential applications and underscoring their strategic significance in advancing anti-aging strategies.

Engineered Extracellular Vesicles from Antler Blastema Progenitor Cells: A Therapeutic Choice for Spinal Cord Injury

Deer antler blastema progenitor cells (ABPCs) are promising for regenerative medicine due to their role in annual antler regeneration, the only case of complete organ regeneration in mammals. ABPC-derived signals show great potential for promoting regeneration in tissues with limited natural regenerative ability. Our findings demonstrate the capability of extracellular vesicles from ABPCs (EVsABPC) to repair spinal cord injury (SCI), a condition with low regenerative capacity. EVsABPC significantly enhanced the proliferation of neural stem cells (NSCs) and activated neuronal regenerative potential, resulting in a 5.2-fold increase in axonal length. Additionally, EVsABPC exhibited immunomodulatory effects, shifting macrophages from M1 to M2. Engineered with activated cell-penetrating peptides (ACPPs), EVsABPC significantly outperformed EVs from rat bone marrow stem cells (EVsBMSC) and neural stem cells (EVsNSC), promoting a 1.3-fold increase in axonal growth, a 30.6% reduction in neuronal apoptosis, and a 2.6-fold improvement in motor function recovery. These findings support ABPC-derived EVs as a promising therapeutic candidate for SCI repair.