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

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury: state of the art and future perspectives

"Peripheral nerve injury" refers to damage or trauma affecting nerves outside the brain and spinal cord. Peripheral nerve injury results in movements or sensation impairments, and represents a serious public health problem. Although severed peripheral nerves have been effectively joined and various therapies have been offered, recovery of sensory or motor functions remains limited, and efficacious therapies for complete repair of a nerve injury remain elusive. The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function. Mesenchymal stem cells, as large living cells responsive to the environment, secrete various factors and exosomes. The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins, microRNA, and messenger RNA derived from parent mesenchymal stem cells. Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function, offering solutions to changes associated with cell-based therapies. Despite ongoing investigations, mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage. A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation. This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury, exploring the underlying mechanisms. Subsequently, it provides an overview of the current status of mesenchymal stem cell and exosome-based therapies in clinical trials, followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes. Finally, the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes, offering potential solutions and guiding future directions.

Utilizing engineered extracellular vesicles as delivery vectors in the management of ischemic stroke: a special outlook on mitochondrial delivery

Ischemic stroke is a secondary cause of mortality worldwide, imposing considerable medical and economic burdens on society. Extracellular vesicles, serving as natural nano-carriers for drug delivery, exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke. However, the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency. By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles, their delivery efficacy may be greatly improved. Furthermore, previous studies have indicated that microvesicles, a subset of large-sized extracellular vesicles, can transport mitochondria to neighboring cells, thereby aiding in the restoration of mitochondrial function post-ischemic stroke. Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components, such as proteins or deoxyribonucleic acid, or their sub-components, for extracellular vesicle-based ischemic stroke therapy. In this review, we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies. Given the complex facets of treating ischemic stroke, we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process. Moreover, given the burgeoning interest in mitochondrial delivery, we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.

Exosomes: the next-generation therapeutic platform for ischemic stroke

Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery. Therefore, there is an urgent need to develop new methods for the treatment of this condition. Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions. They have low immunogenicity, good stability, high delivery efficiency, and the ability to cross the blood-brain barrier. These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke. The rapid development of nanotechnology has advanced the application of engineered exosomes, which can effectively improve targeting ability, enhance therapeutic efficacy, and minimize the dosages needed. Advances in technology have also driven clinical translational research on exosomes. In this review, we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke, including their anti-inflammation, anti-apoptosis, autophagy-regulation, angiogenesis, neurogenesis, and glial scar formation reduction effects. However, it is worth noting that, despite their significant therapeutic potential, there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes. Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke. Ultimately, our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.

Genetically modified extracellular vesicles loaded with activated gasdermin D potentially inhibit prostate-specific membrane antigen-positive prostate carcinoma growth and enhance immunotherapy

Prostate cancer (PCa) is associated with poor immunogenicity and lymphocytic infiltration, and immunotherapy effective against PCa remains unavailable. Pyroptosis, a novel immunotherapeutic modality for cancer, promotes systemic immune responses leading to immunogenic cell death in solid tumors. This paper describes the preparation and analysis of PSMAscFv-EVN-GSDMD; this genetically engineered recombinant extracellular vesicle (EV) expresses a single-chain variable antibody fragment (scFv) with high affinity for prostate-specific membrane antigen (PSMA) on their surfaces and is loaded with the N-terminal domain of gasdermin D (GSDMD). Both in vitro and in vivo, PSMAscFv-EVN-GSDMD effectively targeted PSMA-positive PCa cells and induced pyroptosis through the carrier properties of EVs and the specificity of PSMAscFv. In the 22RV1 and PSMA-transfected RM-1-inoculated PCa mouse models, PSMAscFv-EVN-GSDMD efficiently inhibited tumor growth and promoted tumor immune responses. In conclusion, PSMAscFv-EVN-GSDMD can convert the immunosuppressive "cold" tumor microenvironment of PCa into an immunogenic "hot" tumor microenvironment.

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.

Surface-enhanced infrared spectroscopic study of extracellular vesicles using plasmonic gold nanoparticles

Extracellular vesicles (EVs), sub-micrometer lipid-bound particles released by most cells, are considered a novel area in both biology and medicine. Among characterization methods, infrared (IR) spectroscopy, especially attenuated total reflection (ATR), is a rapidly emerging label-free tool for molecular characterization of EVs. The relatively low number of vesicles in biological fluids (∼1010 particle/mL), however, and the complex content of the EVs' milieu (protein aggregates, lipoproteins, buffer molecules) might result in poor signal-to-noise ratio in the IR analysis of EVs. Exploiting the increment of the electromagnetic field at the surface of plasmonic nanomaterials, surface-enhanced infrared spectroscopy (SEIRS) provides an amplification of characteristic IR signals of EV samples. Negatively charged citrate-capped and positively charged cysteamine-capped gold nanoparticles with around 10 nm diameter were synthesized and tested with blood-derived EVs. Both types of gold nanoparticles contributed to an enhancement of the EVs' IR spectroscopic signature. Joint evaluation of UV-Vis and IR spectroscopic results, supported by FF-TEM images, revealed that proper interaction of gold nanoparticles with EVs is crucial, and an aggregation or clustering of gold nanoparticles is necessary to obtain the SEIRS effect. Positively charged gold nanoparticles resulted in higher enhancement, probably due to electrostatic interaction with EVs, commonly negatively charged.

Extracellular Vesicles-in-Hydrogel (EViH) targeting pathophysiology for tissue repair

Regenerative medicine endeavors to restore damaged tissues and organs utilizing biological approaches. Utilizing biomaterials to target and regulate the pathophysiological processes of injured tissues stands as a crucial method in propelling this field forward. The Extracellular Vesicles-in-Hydrogel (EViH) system amalgamates the advantages of extracellular vesicles (EVs) and hydrogels, rendering it a prominent biomaterial in regenerative medicine with substantial potential for clinical translation. This review elucidates the development and benefits of the EViH system in tissue regeneration, emphasizing the interaction and impact of EVs and hydrogels. Furthermore, it succinctly outlines the pathophysiological characteristics of various types of tissue injuries such as wounds, bone and cartilage injuries, cardiovascular diseases, nerve injuries, as well as liver and kidney injuries, underscoring how EViH systems target these processes to address related tissue damage. Lastly, it explores the challenges and prospects in further advancing EViH-based tissue regeneration, aiming to impart a comprehensive understanding of EViH. The objective is to furnish a thorough overview of EViH in enhancing regenerative medicine applications and to inspire researchers to devise innovative tissue engineering materials for regenerative medicine.

Ovarian cancer extracellular vesicle biomarkers

Ovarian cancer (OC) remains a significant women's health concern due to its high mortality rate and the challenges posed by late detection. Exploring novel biomarkers could lead to earlier, more specific diagnoses and improved survival rates for OC patients. This review focuses on biomarkers associated with extracellular vesicles (EVs) found in various proximal fluids, including urine, ascites, utero-tubal lavage fluid of OC patients. We highlight these proximal fluids as rich sources of potential biomarkers. The review explains the roles of EV biomarkers in ovarian cancer progression and discusses EV-related proteins and miRNAs as potential diagnostic or prognostic indicators and therapeutic targets. Finally, we highlighted the limitations of examining proximal fluids as sources of biomarkers and encourage researchers to proactively pursue innovative solutions to overcome these challenges.

Plasma extracellular vesicles regulate the Functions of Th2 and ILC2 cells via miRNA-150-5p in patients with allergic rhinitis

Allergic rhinitis (AR), a chronic airway inflammation, has witnessed a rising prevalence in recent decades. Recent research indicates that various EVs are released into plasma in allergic airway inflammation, correlating with impaired airway function and severe inflammation. However, the contribution of plasma EVs to AR pathogenesis remains incompletely understood. We isolated plasma EVs using differential ultracentrifugation or size exclusion chromatography (SEC) and obtained differential microRNA (miRNA) expression profiles through miRNA sequencing. Peripheral blood mononuclear cells (PBMCs) were exposed to plasma EVs and miRNA mimics and inhibitors to assess the effect of plasma EVs and the underlying mechanisms. We found that EVs from HC and AR patients exhibited comparable characteristics in terms of concentration, structure, and EV marker expression. AR-EVs significantly enhanced Th2 cell levels and promoted ILC2 differentiation and IL-13+ ILC2 levels compared to HC-EVs. Both HC-EVs and AR-EVs were efficiently internalized by CD4+ T cells and ILCs. miRNA sequencing of AR-EVs revealed unique miRNA signatures implicated in diverse biological processes, among which miR-150-5p, miR-144-3p, miR-10a-5p, and miR-10b-5p were identified as pivotal contributors to AR-EVs' effects on CD4+ T cells and ILC2s. MiR-150-5p exhibited the most pronounced impact on cell differentiation and was confirmed to be upregulated in AR-EVs by PCR. In total, our study demonstrated that plasma EVs from patients with AR exhibited a pronounced capacity to significantly enhance the differentiation of Th2 cells and ILC2, which was correlated with an elevated expression of miR-150-5p within AR-EVs. These findings contribute to the advancement of our comprehension of EVs in the pathogenesis of AR and hold the potential to unveil novel therapeutic targets for the treatment of AR.

Role of extracellular vesicles in the pathogenesis of mosquito-borne flaviviruses that impact public health

Mosquito-borne flaviviruses represent a public health challenge due to the high-rate endemic infections, severe clinical outcomes, and the potential risk of emerging global outbreaks. Flavivirus disease pathogenesis converges on cellular factors from vectors and hosts, and their interactions are still unclear. Exosomes and microparticles are extracellular vesicles released from cells that mediate the intercellular communication necessary for maintaining homeostasis; however, they have been shown to be involved in disease establishment and progression. This review focuses on the roles of extracellular vesicles in the pathogenesis of mosquito-borne flavivirus diseases: how they contribute to viral cycle completion, cell-to-cell transmission, and cellular responses such as inflammation, immune suppression, and evasion, as well as their potential use as biomarkers or therapeutics (antiviral or vaccines). We highlight the current findings concerning the functionality of extracellular vesicles in different models of dengue virus, Zika virus, yellow fever virus, Japanese encephalitis virus, and West Nile virus infections and diseases. The available evidence suggests that extracellular vesicles mediate diverse functions between hosts, constituting novel effectors for understanding the pathogenic mechanisms of flaviviral diseases.

The microRNA profile of brain-derived extracellular vesicles: A promising step forward in developing pharmacodynamic biomarkers for psychiatric disorders

MicroRNAs (miRNAs) have the potential to affect drug metabolism, and some drugs affect cellular miRNA expression. miRNAs are found inside extracellular vesicles (EVs), and the profile of these EV-miRNAs can change across different diseases and disease states. Consequently, in recent years EV-miRNAs have attracted increasing attention as possible non-invasive biomarkers. For example, analyzing the miRNA expression profile of brain-derived EVs in blood may allow us to non-invasively assess miRNA dysregulation and thus to gain knowledge about the pathophysiology of psychiatric disorders and identify potential new predictive targets. We searched PubMed for all studies related to the effects of psychiatric medications on EV-miRNAs and identified 14 relevant articles. Taken together, findings indicate that certain EV-miRNAs may be targets for psychiatric medications and that antipsychotics such as olanzapine and antidepressants such as fluoxetine may alter the expression levels of particular EV-miRNAs. If confirmed and replicated, these findings may lead to the suggested miRNA profiles being used as pharmacodynamic biomarkers. However, heterogeneities and uncertainties remain regarding the role of EV-miRNAs in psychiatric disorders and their interaction with neuronal gene expression and drugs. This minireview summarizes some of the findings on the effects of psychiatric medications on EV-miRNAs and describes the potential role of EV-miRNAs as pharmacodynamic biomarkers for psychiatric disorders.

Platelet-derived extracellular vesicles in cardiovascular disease and treatment - from maintaining homeostasis to targeted drug delivery

PURPOSE OF REVIEW

Cardiovascular disease (CVD) remains a major global health burden. Rising incidences necessitate improved understanding of the pathophysiological processes underlying disease progression to foster the development of novel therapeutic strategies. Besides their well recognized role in CVD, platelet-derived extracellular vesicles (PEVs) mediate inter-organ cross talk and contribute to various inflammatory diseases.

RECENT FINDINGS

PEVs are readily accessible diagnostic biomarkers that mirror pathophysiological disease progression but also may confer cardioprotective properties. Monitoring the effects of modulation of PEV signatures through pharmacotherapies has also provided novel insights into treatment efficacy. Furthermore, exploiting their inherent ability to infiltrate thrombi, atherosclerotic plaques and solid tumours, PEVs as well as platelet-membrane coated nanoparticles are emerging as novel effective and targeted treatment options for CVD and cancer.

SUMMARY

Collectively, in-depth characterization of PEVs in various diseases ultimately enhances their use as diagnostic or prognostic biomarkers and potential therapeutic targets, making them clinically relevant candidates to positively impact patient outcomes.

Wildfire-relevant woodsmoke and extracellular vesicles (EVs): Alterations in EV proteomic signatures involved in extracellular matrix degradation and tissue injury in airway organotypic models

Wildfires adversely impact air quality and public health worldwide. Exposures to wildfire smoke are linked to adverse health outcomes, including cardiopulmonary diseases. Critical research gaps remain surrounding the underlying biological pathways leading to wildfire-induced health effects. The regulation of intercellular communication and downstream toxicity driven by extracellular vesicles (EVs) is an important, understudied biological mechanism. This study investigated EVs following a wildfire smoke-relevant in vitro exposure. We hypothesized that woodsmoke (WS) would alter the proteomic content of EVs secreted in organotypic in vitro airway models. Exposures were carried out using a tri-culture model of alveolar epithelial cells, fibroblasts, and endothelial cells and a simplified co-culture model of alveolar epithelial cells and fibroblasts to inform responses across different cell populations. Epithelial cells were exposed to WS condensate and EVs were isolated from basolateral conditioned medium following 24 h exposure. WS exposure did not influence EV particle characteristics, and it moderately increased EV count. Exposure caused the differential loading of 25 and 35 proteins within EVs collected from the tri- and co-culture model, respectively. EV proteins involved in extracellular matrix degradation and wound healing were consistently modulated across both models. However, distinct proteins involved in the wound healing pathway were altered between models, suggesting unique but concerted efforts across cell types to communicate in response to injury. These findings demonstrate that a wildfire-relevant exposure alters the EV proteome and suggest an impact on EV-mediated intercellular communication. Overall, results demonstrate the viability of organotypic approaches in evaluating EVs to investigate exposure-induced biomarkers and underlying mechanisms. Findings also highlight the impact of differences in the biological complexity of in vitro models used to evaluate the effects of inhaled toxicants.

Precision Medicine for Pulmonary Vascular Disease: The Future Is Now (2023 Grover Conference Series)

Pulmonary vascular disease is not a single condition; rather it can accompany a variety of pathologies that impact the pulmonary vasculature. Applying precision medicine strategies to better phenotype, diagnose, monitor, and treat pulmonary vascular disease is increasingly possible with the growing accessibility of powerful clinical and research tools. Nevertheless, challenges exist in implementing these tools to optimal effect. The 2023 Grover Conference Series reviewed the research landscape to summarize the current state of the art and provide a better understanding of the application of precision medicine to managing pulmonary vascular disease. In particular, the following aspects were discussed: (1) Clinical phenotypes, (2) genetics, (3) epigenetics, (4) biomarker discovery, (5) application of precision biology to clinical trials, (6) the right ventricle (RV), and (7) integrating precision medicine to clinical care. The present review summarizes the content of these discussions and the prospects for the future.

Endometrial extracellular vesicles regulate processes related to embryo development and implantation in human blastocysts

STUDY QUESTION

What is the transcriptomic response of human blastocysts following internalization of extracellular vesicles (EVs) secreted by the human endometrium?

SUMMARY ANSWER

EVs secreted by the maternal endometrium induce a transcriptomic response in human embryos that modulates molecular mechanisms related to embryo development and implantation.

WHAT IS KNOWN ALREADY

EVs mediate intercellular communication by transporting various molecules, and endometrial EVs have been postulated to be involved in the molecular regulation of embryo implantation. Our previous studies showed that endometrial EVs carry miRNAs and proteins associated with implantation events that can be taken up by human blastocysts; however, no studies have yet investigated the transcriptomic response of human embryos to this EV uptake, which is crucial to demonstrate the functional significance of this communication system.

STUDY DESIGN, SIZE, DURATION

A prospective descriptive study was performed. Primary human endometrial epithelial cells (pHEECs), derived from endometrial biopsies collected from fertile oocyte donors (n = 20), were cultured in vitro to isolate secreted EVs. Following EV characterization, Day 5 human blastocysts (n = 24) were cultured in the presence or absence of the EVs for 24 h and evaluated by RNA-sequencing.

PARTICIPANTS/MATERIALS, SETTING, METHODS

EVs were isolated from the conditioned culture media using ultracentrifugation, and characterization was performed using western blot, nanoparticle tracking analysis, and transmission electron microscopy. Human blastocysts were devitrified, divided into two groups (n = 12/group), and cultured in vitro for 24 h with or without previously isolated EVs. RNA-sequencing analysis was performed, and DESeq2 was used to identify differentially expressed genes (DEGs) (FDR < 0.05). QIAGEN Ingenuity Pathway Analysis was used to perform the functional enrichment analysis and integration with our recently published data from the pHEECs' EV-miRNA cargo.

MAIN RESULTS AND THE ROLE OF CHANCE

Characterization confirmed the isolation of EVs from pHEECs' conditioned culture media. Among the DEGs in blastocysts co-cultured with EVs, we found 519 were significantly upregulated and 395 were significantly downregulated. These DEGs were significantly enriched in upregulated functions related to embryonic development, cellular invasion and migration, cell cycle, cellular organization and assembly, gene expression, and cell viability; and downregulated functions related to cell death and DNA fragmentation. Further, the intracellular signaling pathways regulated by the internalization of endometrial EVs were previously related to early embryo development and implantation potential, for their role in pluripotency, cellular homeostasis, early embryogenesis, and implantation-related processes. Finally, integrating data from miRNA cargo of EVs, we found that the miRNAs carried by endometrial EVs targeted nearly 80% of the DEGs in human blastocysts.

LIMITATIONS, REASONS FOR CAUTION

This is an in vitro study in which conditions of endometrial cell culture could not mimic the intrauterine environment.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides novel insights into the functional relevance of EVs secreted by the human endometrium, and particularly the role of EV-miRNA regulation on global transcriptome behavior of human blastocysts during early embryogenesis and embryo implantation. It provides potential biomarkers that could become useful diagnostic targets for predicting implantation success.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Spanish Ministry of Education through FPU awarded to M.S.-B. (FPU18/03735), Generalitat Valenciana through VALi+d Programme awarded to M.C.C.-G. (ACIF/2019/139), and Instituto de Salud Carlos III and cofounded by the European Social Fund (ESF) "Investing in your future" through the Miguel Servet Program (CP20/00120 [H.F.]; CP19/00149 [I.C.]). The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

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

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

Isolation and Characterization of Exosomes from Ocular Samples

Exosomes are microsize vesicles secreted by nearly all cells to the extracellular space. The vesicles transport cell signaling and communicate with other cells. Ultracentrifugation is the standard method to isolate exosomes from culture media or body fluid. Without ultracentrifuge, exosomes can be precipitated by polyethylene glycol or separated by size exclusion chromatography. After isolation, nanoparticle tracking analysis can help to estimate the size and concentration of exosome samples. Transmission electron microscopy can directly show the size and morphology of exosomes. Moreover, the sample should be characterized by the expression of several exosome biomarker proteins. Exosomal contents such as proteins and miRNAs could be profiled using appropriate technologies.

miRNA-21-5p is an important contributor to the promotion of injured peripheral nerve regeneration using hypoxia-pretreated bone marrow-derived neural crest cells

JOURNAL/nrgr/04.03/01300535-202501000-00035/figure1/v/2024-05-14T021156Z/r/image-tiff Our previous study found that rat bone marrow-derived neural crest cells (acting as Schwann cell progenitors) have the potential to promote long-distance nerve repair. Cell-based therapy can enhance peripheral nerve repair and regeneration through paracrine bioactive factors and intercellular communication. Nevertheless, the complex contributions of various types of soluble cytokines and extracellular vesicle cargos to the secretome remain unclear. To investigate the role of the secretome and extracellular vesicles in repairing damaged peripheral nerves, we collected conditioned culture medium from hypoxia-pretreated neural crest cells, and found that it significantly promoted the repair of sensory neurons damaged by oxygen-glucose deprivation. The mRNA expression of trophic factors was highly expressed in hypoxia-pretreated neural crest cells. We performed RNA sequencing and bioinformatics analysis and found that miR-21-5p was enriched in hypoxia-pretreated extracellular vesicles of neural crest cells. Subsequently, to further clarify the role of hypoxia-pretreated neural crest cell extracellular vesicles rich in miR-21-5p in axonal growth and regeneration of sensory neurons, we used a microfluidic axonal dissociation model of sensory neurons in vitro, and found that hypoxia-pretreated neural crest cell extracellular vesicles promoted axonal growth and regeneration of sensory neurons, which was greatly dependent on loaded miR-21-5p. Finally, we constructed a miR-21-5p-loaded neural conduit to repair the sciatic nerve defect in rats and found that the motor and sensory functions of injured rat hind limb, as well as muscle tissue morphology of the hind limbs, were obviously restored. These findings suggest that hypoxia-pretreated neural crest extracellular vesicles are natural nanoparticles rich in miRNA-21-5p. miRNA-21-5p is one of the main contributors to promoting nerve regeneration by the neural crest cell secretome. This helps to explain the mechanism of action of the secretome and extracellular vesicles of neural crest cells in repairing damaged peripheral nerves, and also promotes the application of miR-21-5p in tissue engineering regeneration medicine.

Lipidomic and transcriptomic characteristics of boar seminal plasma extracellular vesicles associated with sperm motility

Seminal plasma extracellular vesicles (SPEVs) play an important role in regulating sperm motility by delivering various cargoes, such as miRNAs, mRNAs, proteins and metabolites. However, information on the lipid compositions of SPEVs and their roles in semen quality is limited. Here, we performed high-throughput transcriptomic and lipidomic analysis on SPEVs isolated from 20 boars with high or low sperm motility. Then, we evaluated the lipid composition and gene expression characteristics of SPEVs and identified the specific lipids and genes related to sperm motility. As a result, a total of 26 lipid classes were identified in SPEVs, and five subclasses, CerG2, CerG3, LPE, LPS and TG, were significantly different in boars with high and low sperm motility. In addition, 195 important lipids and 334 important genes were identified by weighted gene coexpression analysis (WGCNA) and differential expression analysis. We observed that several important genes and lipids in SPEVs potentially influence sperm motility via glycerophospholipid metabolism, glycerolipid metabolism, the sphingolipid signaling pathway and the ferroptosis pathway. Furthermore, we found a significant correlation between the content of 22 lipids and the expression levels of 67 genes (|cor| > 0.8, P < 0.05). Moreover, we observed that three important gene-lipid linkages (CerG1 (d22:0/24:0) - RCAN3, Cer (d18:1/24:0) - SCFD2 and CerG1 (d18:0/24:1) - SCFD2) were strongly correlated with sperm motility. Based on the results, some genes and lipids in SPEVs may play important roles in sperm motility by interacting with sperm through important pathways.

Inflammatory pain resolution by mouse serum-derived small extracellular vesicles

Current treatments for chronic pain have limited efficacy and significant side effects, warranting research on alternative strategies for pain management. One approach involves using small extracellular vesicles (sEVs), or exosomes, to transport beneficial biomolecular cargo to aid pain resolution. Exosomes are 30-150 nm sEVs that can be beneficial or harmful depending on their source and cargo composition. We report a comprehensive multi-modal analysis of different aspects of sEV characterization, miRNAs, and protein markers across sEV sources. To investigate the short- and long-term effects of mouse serum-derived sEVs in pain modulation, sEVs from naïve control or spared nerve injury (SNI) model male donor mice were injected intrathecally into naïve male recipient mice. These sEVs transiently increased basal mechanical thresholds, an effect mediated by opioid signaling as this outcome was blocked by naltrexone. Mass spectrometry of sEVs detected endogenous opioid peptide leu-enkephalin. sEVs from naïve female mice have higher levels of leu-enkephalin compared to male, matching the analgesic onset of leu-enkephalin in male recipient mice. In investigating the long-term effect of sEVs, we observed that a single prophylactic intrathecal injection of sEVs two weeks prior to induction of the pain model in recipient mice accelerated recovery from inflammatory pain after complete Freund's adjuvant (CFA) injection. Our exploratory studies examining immune cell populations in spinal cord and dorsal root ganglion using ChipCytometry suggested alterations in immune cell populations 14 days post-CFA. Flow cytometry confirmed increases in CD206+ macrophages in the spinal cord in sEV-treated mice. Collectively, these studies demonstrate multiple mechanisms by which sEVs can attenuate pain.

Enhancing epithelial regeneration with gelatin methacryloyl hydrogel loaded with extracellular vesicles derived from adipose mesenchymal stem cells for decellularized tracheal patching

Patch tracheoplasty offers an alternative approach to repairing congenital tracheal stenosis without tension but poses a higher risk of restenosis, granulation tissue formation, and tracheal collapse. The use of tissue-engineered patches for tracheoplasty has been proposed as a solution. Studies suggest that decellularization methods are effective in preparing tracheal patches; however, further research is necessary to improve their efficiency and safety. This study introduces a novel decellularization method using 3-[(3Cholamidopropyl)dimethylammonio]propanesulfonate (CHAPS) and DNase to create a biocompatible tracheal matrix. To enhance the regeneration of epithelial regions within decellularized tracheal scaffolds, this study conducted experimental validations at various levels, both in vivo and in vitro, by introducing extracellular vesicles derived from adipose mesenchymal stem cells as an intervention measure. The ability to promote epithelial regeneration was validated both in vitro and in vivo by incorporating a GelMA hydrogel loaded with adipose-derived mesenchymal stem cell extracellular vesicles (ADMSC-EVs). Evaluation of HBE cell proliferation on tracheal patches treated with varying concentrations of ADMSC-EVs, along with migration and invasion experiments on ADMSC-EV-treated HBE cells, demonstrated enhanced epithelialization in vitro. The inflammatory response and vascular regeneration were assessed via subcutaneous implantation in rats for two weeks. In a rabbit tracheal defect model, the hydrogel loaded with ADMSC-EVs accelerated re-epithelialization in the patch area. This approach shows promise as a novel material for tracheal patching in clinical applications.

Separation and Purification of CHO Secretome and Extracellular Vesicles for Proteome Analysis

For decades, host cell proteins (HCPs) have been investigated as putative contaminants in downstream processing of biopharmaceutical products of Chinese hamster ovary (CHO) cells. However, little is still known about the composition of the entire protein and vesicle environment in CHO cultivations. Ever evolving mass spectrometry techniques allow more and more insights into cell-cell communication processes and the composition of extracellular matrix, proteases, and further actively segregated compounds such as extracellular vesicles (EVs). EVs themselves are a heterologous group consisting of exosomes, ectosomes, and apoptotic vesicles. To specifically analyze these subsets of the secretome and determine beneficial and detrimental factors for a production process, targeted separation and purification techniques are necessary.In this chapter, we present our optimized workflows for a clear differentiation between directly secreted proteins and the vesicular protein content of different fractions (especially exosomal small EVs) from CHO cell supernatant for proteomic analysis by NanoLC ESI-MS.

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

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

Macrophage heterogeneity regulation by small extracellular vesicles from adipose-derived stem cells: A promising approach for treating chronic prostatitis/pelvic pain syndrome

chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is an intractable aseptic disease. Modulating the transition of macrophages from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype offers an attractive therapeutic approach. Recently, small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) reportedly have potent modulatory abilities, however, their applications are limited by suboptimal targeting. Our group hypothesized that surface modification of sEVs derived from ADSCs are useful for the management of CP/CPPS by promoting M1/M2 macrophage phenotypic transformation. In this study, a novel nanomaterial (CD86-sEVs) is designed for CP/CPPS treatment using click chemistry, a bioconjugation technique enabling robust covalent linkages. The results of immunofluorescence staining, western blot and ELISA confirmed that azide-modified CD86 antibody was successfully conjugated onto the sEVs surface. In vitro, CD86-sEVs significantly accelerated M1 macrophage polarization to M2 and upregulated anti-inflammatory factors. In vivo, CD86-sEVs targeted the prostatic lesion region, alleviated chronic pelvic pain, and inhibited inflammation by promoting M1/M2 phenotype shift. Furthermore, miRNA array analysis identified specific miRNAs (miR-26a, miR-147, miR-17, miR-21, miR-182, miR-451a) within CD86-sEVs that likely contributed to these observed effects. In sum, this study presents a novel paradigm for the treatment of CP/CPPS.

Extracellular vesicles as emerging players in glaucoma: Mechanisms, biomarkers, and therapeutic targets

In recent years, extracellular vesicles (EVs) have attracted significant scientific interest due to their widespread distribution, their potential as disease biomarkers, and their promising applications in therapy. Encapsulated by lipid bilayers these nanovesicles include small extracellular vesicles (sEV) (30-150 nm), microvesicles (100-1000 nm), and apoptotic bodies (100-5000 nm) and are essential for cellular communication, immune responses, biomolecular transport, and physiological regulation. As they reflect the condition and functionality of their originating cells, EVs play critical roles in numerous physiological processes and diseases. Therefore, EVs offer valuable opportunities for uncovering disease mechanisms, enhancing drug delivery systems, and identifying novel biomarkers. In the context of glaucoma, a leading cause of irreversible blindness, the specific roles of EVs are still largely unexplored. This review examines the emerging role of EVs in the pathogenesis of glaucoma, with a focus on their potential as diagnostic biomarkers and therapeutic agents. Through a thorough analysis of current literature, we summarize key advancements in EV research and identify areas where further investigation is needed to fully understand their function in glaucoma.

Enhancing EV-cell communication through "External Modulation of Cell by EV" (EMCEV)

Mesenchymal stem/stromal cells (MSC) have displayed promising therapeutic potential. Nonetheless, no United States Food and Drug Administration (FDA)-approved MSC product exists due largely to the absence of a reliable potency assay based on the mechanisms of action to ensure consistent efficacy. MSCs are now thought to exert their effects primarily by releasing small extracellular vesicles (sEVs) of 50-200 nm. While non-living MSC-sEV drugs offer distinct advantages over larger, living MSC drugs, elucidating their mechanism of action to develop robust potency assays remains a challenge. A pivotal prelude to elucidating the mechanism of action for MSC-sEVs is how extracellular vesicles (EVs) engage their primary target cells. Given the inherent inefficiencies of processes such as endocytosis, endosomal escape and EV uncoating during cellular internalization, we propose an alternative EV-cell engagement: EMCEV (Extracellular Modulation of Cells by EV). This approach involves extracellular modulation by EV attributes to generate signaling/inhibitory molecules that have the potential to affect many cells within the vicinity, thereby eliciting a more widespread tissue response.

Engineered Nanoparticles for Theranostic Applications in Kidney Repair

Kidney diseases are characterized by their intricate nature and complexity, posing significant challenges in their treatment and diagnosis. Nanoparticles (NPs), which can be further classified as synthetic and biomimetic NPs, have emerged as promising candidates for treating various diseases. In recent years, the development of engineered nanotherapeutics has focused on targeting damaged tissues and serving as drug delivery vehicles. Additionally, these NPs have shown superior sensitivity and specificity in diagnosis and imaging, thus providing valuable insights for the early detection of diseases. This review aims to focus on the application of engineered synthetic and biomimetic NPs in kidney diseases in the aspects of treatment, diagnosis, and imaging. Notably, the current perspectives and challenges are evaluated, which provide inspiration for future research directions, and encourage the clinical application of NPs in this field.

Plasma-derived exosomes of Edwardsiella piscicida challenged olive flounder (Paralichthys olivaceus): Characterization and miRNA profiling for potential biomarkers screening

Exosomes are released from multiple cell types as part of their normal physiology as well as during acquired abnormalities. In this study, we investigated the effect of pathogenic Edwardsiella piscicida infection on olive flounder (Paralichthys olivaceus) exosomes at morphometric, physicochemical, and molecular levels. Unique cup-shaped exosomes were isolated from the plasma of non-infected (PBS-Exo) and E. piscicida experimentally challenged (Ep-Exo) olive flounder using ultracentrifugation. The average particle size, concentration, and zeta potential were 150.9 ± 6.9 nm, 5.67 × 1010 particles/mL, and -25.6 ± 1.36 mV for PBS-Exo while 138.7 ± 1.9 nm, 1.22 × 1011 particles/mL, and -35 ± 1.82 mV for Ep-Exo, respectively. Expression of tetraspanin markers (CD81, CD9, and CD63) confirmed the presence of olive flounder exosomes. Differentially expressed (DE) known (9) and novel (29) miRNAs (log2 fold change ≥1; p < 0.05) were identified in the Ep-Exo that could be potential as diagnostic biomarkers for the infection. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the predicted target genes of the DE miRNAs were highly enriched in metabolic and immune roles. Both PBS-Exo and Ep-Exo were non-toxic in vitro (up to 100 μg/mL) and in vivo (up to 400 μg/mL). Compared to the vehicle, PBS-Exo at 50 μg/mL induced Nf-kB (>1.50-fold) while at 100 μg/mL, Il8, Il10, Nf-kB, P53, and Inf were induced (>1.50-fold) in fathead minnow cells (FHMs). This suggests that the PBS-Exo contains molecules that moderately stimulate gene expression. In the future, validating the exact olive flounder immune response target genes that interact with DE miRNAs in Ep-Exo will be crucial for investigating the host-pathogen interactions, immune defense mechanisms, and therapeutic targets for olive flounder against E. piscicida infection.

Effect of clinically relevant antibiotics on bacterial extracellular vesicle release from Escherichia coli

Sepsis, a leading cause of death in hospitals, can be defined as a dysregulated host inflammatory response to infection, which can lead to tissue damage, organ failure and cardiovascular complications. Although there is no cure for sepsis, the condition is typically managed with broad-spectrum antibiotics to eliminate any potential bacterial source of infection. However, a potential side effect of antibiotic treatment is the enhanced release of bacterial extracellular vesicles (BEVs), membrane-bound nanoparticles containing proteins and other biological molecules from their parent bacterium. Some of the Gram-negative extracellular vesicle (EV) cargo, including peptidoglycan associated lipoprotein and outer membrane protein A, have been shown to induce both acute and chronic inflammation in host tissue. It was hypothesized that the antibiotic concentration and mechanism of action may affect the amount of released BEVs, which could potentially exacerbate the host inflammatory response. This study evaluated nine clinically relevant antibiotics for their effect on EV release from Escherichia coli. Several beta-lactam antibiotics caused significantly more EV release, while quinolone and aminoglycoside antibiotics caused less vesiculation. Further study is warranted to corroborate the correlation between an antibiotic's mechanism of action and its effect on EV release, but these results underline the importance of antibiotic choice when treating patients with sepsis.

Loading of Extracellular Vesicles with Nucleic Acids via Hybridization with Non-Lamellar Liquid Crystalline Lipid Nanoparticles

The translation of cell-derived extracellular vesicles (EVs) into biogenic gene delivery systems is limited by relatively inefficient loading strategies. In this work, the loading of various nucleic acids into small EVs via their spontaneous hybridization with preloaded non-lamellar liquid crystalline lipid nanoparticles (LCNPs), forming hybrid EVs (HEVs) is described. It is demonstrated that LCNPs undergo pH-dependent structural transitions from inverse hexagonal (HII) phases at pH 5 to more disordered non-lamellar phases, possibly inverse micellar (L2) or sponge (L3) phases, at pH 7.4, which are particularly suitable for inducing a controlled hybridization process with EVs. State-of-the-art single-particle analysis techniques reveal that LCNPs interact with various EV subpopulations at physiological conditions and that ≈40% of HEVs are loaded with the genetic cargo. Importantly, this study demonstrates that EV membrane proteins remain accessible on HEV surfaces, with their intrinsic enzymatic activity unaffected after the hybridization process. Finally, HEVs show in vitro improved transfection efficiencies compared to unhybridized LCNPs. In summary, this versatile platform holds potential for loading various nucleic acid molecules into native EVs and may help developing EV-based therapeutics.

Immunotherapy and delivery systems for melanoma

Melanoma is a highly malignant tumor of melanocyte origin that is prone to early metastasis and has a very poor prognosis. Early melanoma treatment modalities are mainly surgical, and treatment strategies for advanced or metastatic melanoma contain chemotherapy, radiotherapy, targeted therapy and immunotherapy. The efficacy of chemotherapy and radiotherapy has been unsatisfactory due to low sensitivity and strong toxic side effects. And targeted therapy is prone to drug resistance, so its clinical application is limited. Melanoma has always been the leader of immunotherapy for solid tumors, and how to maximize the role of immunotherapy and how to implement immunotherapy more accurately are still urgent to be explored. This review summarizes the common immunotherapies and applications for melanoma, illustrates the current research status of melanoma immunotherapy delivery systems, and discusses the advantages and disadvantages of each delivery system and its prospects for clinical application.

Research hotspots and trends regarding microRNAs in hypertension: a bibliometric analysis

To investigate the research levels, hotspots, and development trends regarding microRNAs in hypertension, this study conducted a visual analysis of studies on miRNA in hypertension based on the Web of Science core collection database using CiteSpace and VOSviewer analysis software along with literature from 2005-2023 as information data. Using citation frequency, centrality, and starting year as metrics, this study analyzed the research objects. It revealed the main research bodies and hotspots and evaluated the sources of literature and the distribution of knowledge from journals and authors. Finally, the potential research directions for miRNAs in hypertension are discussed. The results showed that the research field is in a period of vigorous development, and scholars worldwide have shown strong interest in this research field. A comprehensive summary and analysis of the current research status and application trends will prove beneficial for the advancement of this field.

Parallel single-cell metabolic analysis and extracellular vesicle profiling reveal vulnerabilities with prognostic significance in acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive disease with a high relapse rate. In this study, we map the metabolic profile of CD34+(CD38low/-) AML cells and the extracellular vesicle signatures in circulation from AML patients at diagnosis. CD34+ AML cells display high antioxidant glutathione levels and enhanced mitochondrial functionality, both associated with poor clinical outcomes. Although CD34+ AML cells are highly dependent on glucose oxidation and glycolysis for energy, those from intermediate- and adverse-risk patients reveal increased mitochondrial dependence. Extracellular vesicles from AML are mainly enriched in stem cell markers and express antioxidant GPX3, with their profiles showing potential prognostic value. Extracellular vesicles enhance mitochondrial functionality and dependence on CD34+ AML cells via the glutathione/GPX4 axis. Notably, extracellular vesicles from adverse-risk patients enhance leukemia cell engraftment in vivo. Here, we show a potential noninvasive approach based on liquid 'cell-extracellular vesicle' biopsy toward a redefined metabolic stratification in AML.

Targeting modulation of intestinal flora through oral route by an antimicrobial nucleic acid-loaded exosome-like nanovesicles to improve Parkinson's disease

Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases. It is usually accompanied by motor and non-motor symptoms that seriously threaten the health and the quality of life. Novel medications are urgently needed because current pharmaceuticals can relieve symptoms but cannot stop disease progression. The microbiota-gut-brain axis (MGBA) is closely associated with the occurrence and development of PD and is an effective therapeutic target. Tetrahedral framework nucleic acids (tFNAs) can modulate the microbiome and immune regulation. However, such nucleic acid nanostructures are very sensitive to acids which hinder this promising approach. Therefore, we prepared exosome-like nanovesicles (Exo@tac) from ginger that are acid resistant and equipped with tFNAs modified by antimicrobial peptides (AMP). We verified that Exo@tac regulates intestinal bacteria associated with the microbial-gut-brain axis in vitro and significantly improves PD symptoms in vivo when administered orally. Microbiota profiling confirmed that Exo@tac normalizes the intestinal flora composition of mouse models of PD. Our findings present a novel strategy for the development of PD drugs and the innovative delivery of nucleic acid nanomedicines.

The endoplasmic reticulum as a cradle for virus and extracellular vesicle secretion

Extracellular vesicles (EVs) are small membranous carriers of protein, lipid, and nucleic acid cargoes and play a key role in intercellular communication. Recent work has revealed the previously under-recognized participation of endoplasmic reticulum (ER)-associated proteins (ERAPs) during EV secretion, using pathways reminiscent of viral replication and secretion. Here, we present highlights of the literature involving ER/ERAPs in EV biogenesis and propose mechanistic parallels with ERAPs exploited during viral infections. We propose that ERAPs play an active role in the release of EVs and viral particles, and we present views on whether viruses hijack or enhance pre-existing ERAP-dependent secretory machineries or whether they repurpose ERAPs to create new secretory pathways.

A new strategy for drug delivery systems in oral diseases using stem cell-derived extracellular vesicles: review and new perspectives

Extracellular vesicles (EVs) are membrane vesicles derived from cells and serve as an endogenous mechanism for intercellular communication. Since the discovery of their capacity to effectively transfer biological information, their potential as drug delivery vehicles has garnered significant scientific interest. Particularly, EVs derived from mesenchymal cells (MSC-EVs) have emerged as a highly promising method for drug delivery. They can transport bioactive molecules, such as nucleic acids, lipids, and proteins, and possess the ability to modulate immune responses, transmit information, and target specific cells. EVs offer several advantages over conventional drug delivery systems, including their capacity to traverse natural barriers, inherent cell targeting capabilities, and stability in circulation. Compared to their parent cells, EVs exhibit low immunogenicity, ease of storage and transport, and a reduced risk of tumorigenesis. The diagnosis and treatment of oral diseases often involve invasive measures, and MSC-EVs have demonstrated initial efficacy in oral disease treatment. This review explores the application of MSC-EVs in maxillofacial tissue regeneration, periodontitis, temporomandibular joint osteoarthritis, Sjögren's Syndrome, oral cancer, and other oral diseases. Additionally, it outlines potential future directions for the development of MSC-EVs. This review aims to provide a comprehensive understanding of MSC-EVs in oral disease treatment and to stimulate interest in their applications for targeted drug delivery.

Mesenchymal stem cell therapy in atherosclerosis: A bibliometric and visual analysis

BACKGROUND

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation, and extensive studies have demonstrated their therapeutic potential in atherosclerosis (AS).

AIM

To conduct a bibliometric analysis of studies on the use of MSC therapy for AS over the past two decades, assess key trends and provide insights for future research directions.

METHODS

We systematically searched the Web of Science Core Collection database for articles published between 1999 and 2023, yielding a total of 556 articles. Visual representation and bibliometric analysis of information and trends were facilitated using CiteSpace, the R package 'bibliometrix' and VOSviewer.

RESULTS

The analyzed articles were predominantly from 52 countries/regions, with prominent contributions from China and the United States. A cohort of 3057 authors contributed to these publications, with the works of Libby P distinguished by their influence and citation count. Int J Mol Sci has emerged as the journal with the highest publication volume, prominently disseminating influential papers and identifying citation outbreaks. Furthermore, our analysis identified current research hotspots within the field, focusing on vascular progenitor cells, inflammatory mechanisms, and extracellular vesicles. Emerging research frontiers, such as extracellular vesicles and oxidative stress, have been highlighted as areas of burgeoning interest. Finally, we offer perspectives on the status of research and future directions of MSC therapy in AS.

CONCLUSION

This comprehensive analysis provides valuable insights for advancing scientific research on MSC therapy for AS. By elucidating pivotal trends and research directions, this study aimed to foster innovation and promote the progress of disciplines in this field, thereby contributing to advancing scientific knowledge and clinical practice.

Dual role of extracellular vesicles in neurodegenerative diseases

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

Endplate chondrocyte-derived exosomal miR-128-3p mitigates intervertebral disc degeneration by targeting TRAF6 via the miR-128-3p/TRAF6 axis to suppress pyroptosis

Intervertebral disc degeneration (IVDD) is a leading cause of chronic back pain and significantly impacts quality of life. The pathogenesis of IVDD is largely driven by inflammation, pyroptosis, and extracellular matrix (ECM) degradation, which current therapies fail to adequately address. In this study, we explore the therapeutic potential of exosomes derived from endplate chondrocytes (EPCs), with a particular focus on the microRNA miR-128-3p. Our findings reveal that exosomes isolated from third-generation EPCs, enriched with miR-128-3p, exhibit potent anti-inflammatory and anti-pyroptotic effects in lipopolysaccharide-treated nucleus pulposus cells, which are key contributors to IVDD pathology. Specifically, we demonstrate that miR-128-3p delivered via EPC-derived exosomes directly targets TRAF6, effectively suppressing activation of the NF-κB signaling pathway, which is known to play a pivotal role in inflammation and ECM breakdown, leading to a marked reduction in pro-inflammatory cytokine release and mitigation of ECM degradation. Importantly, third-generation EPC exosomes, with higher levels of miR-128-3p, showed superior efficacy compared to fifth-generation EPCs, underscoring the critical role of miR-128-3p in mediating these protective effects. Our research highlights the promise of EPC-derived exosomes, particularly those rich in miR-128-3p, as a novel, cell-free therapeutic approach for IVDD. Unlike current treatments that focus primarily on symptom management, our approach targets key molecular pathways underlying IVDD progression, including inflammation, pyroptosis, and ECM degradation. By elucidating the miR-128-3p/TRAF6 axis, this study provides a foundation for the development of targeted, biologically based interventions aimed at halting or even reversing IVDD, thereby offering hope for more effective and lasting therapeutic options.

Hypoxia-Induced and Glucuronic Acid-Modified Extracellular Vesicles from Mesenchymal Stromal Cells Treat Pulmonary Arterial Hypertension by Improving Vascular Remodeling

Achieving precise delivery of extracellular vesicles (EVs) to treat pulmonary arterial hypertension (PAH) remains challenging. Here, we propose a strategy using hypoxia-induced and glucuronic acid (GA)-modified mesenchymal stromal-cell-derived EVs (MSC-EVs) to enhance their functionalities and therapeutic targeting. The hypoxia-induced EVs (Hypo-EVs) exhibit enriched exosomal signatures and display heightened inhibition of the proliferation of pulmonary arterial smooth muscle cells (PASMCs) compared to normoxic EVs (Norm-EV). We then modify Hypo-EVs by incorporating GA into their outer membrane, targeting glucose transporter-1 overexpressed on PASMCs. Our studies show that GA-EVs significantly enhance the therapeutic efficacy, both in vitro and in vivo, through improved targeted delivery to diseased PASMCs for improving vascular remodeling. Additionally, we identify miR-5119 involved in the PAH-associated calcium signaling pathway as a key contributor to GA-EVs' superior effects. This work provides a promising strategy for PAH treatment and advances the clinical potential of MSC-EV-based therapies.

A Systematic Review on the Effectiveness and Safety of Combining Biostimulators with Botulinum Toxin, Dermal Fillers, and Energy-Based Devices

INTRODUCTION

Aesthetic medicine has evolved towards minimally invasive procedures, with biostimulators like Poly-L-Lactic Acid (PLLA), Calcium Hydroxylapatite (CaHA), and Polycaprolactone (PCL) gaining attention for their role in collagen induction, improving skin texture, elasticity, and volume. Combining these agents with other treatments-such as botulinum toxin, dermal fillers, and energy-based devices (e.g. laser and radiofrequency therapies)-is hypothesised to provide enhanced aesthetic outcomes. However, studies on the efficacy and safety of these combinations remain sparse and methodologically varied, posing challenges in establishing definitive recommendations.

METHODS

This systematic review adhered to PRISMA guidelines, involving a thorough literature search across PubMed, MEDLINE, Embase, and Cochrane databases. The search included terms related to biostimulators and combination treatments. Studies meeting inclusion criteria reported clinical outcomes of combined biostimulator treatments, including effectiveness, safety, patient satisfaction, and adverse effects. Key parameters extracted included treatment area, combination protocols, and outcomes. Data synthesis used a narrative approach due to variability in methodologies, treatment protocols, and outcome metrics.

RESULTS

Out of 1,237 studies initially identified, 29 met the inclusion criteria. These studies included various combinations of biostimulators with botulinum toxin, dermal fillers, and energy-based devices, with sample sizes ranging from 10 to 350 subjects. Treatments combining CaHA or PLLA with energy-based modalities like high-intensity focused ultrasound (HIFU), fractional lasers, and microneedling demonstrated notable improvements in skin texture, elasticity, and contouring, particularly in areas with ageing signs. Adverse events included erythema, bruising, and nodules in 15-30% of cases, with rare but severe complications such as granulomas and vascular occlusions. Management protocols for these events involved corticosteroids, hyaluronidase, or surgical intervention. The review also found a lack of molecular understanding of the synergistic mechanisms.

CONCLUSION

The review underscores the potential benefits of combined treatments in aesthetic outcomes, though limitations like heterogeneous methodologies, small sample sizes, and inconsistent protocols impact the reliability of findings. Current literature lacks a molecular understanding of the mechanisms underlying these combinations, limiting insights into the longevity and safety of results. Future studies with standardised protocols, objective outcome measures, and detailed molecular analyses are essential for developing evidence-based recommendations for combining biostimulators with other treatments in aesthetic practice.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Enhancing cardiac regeneration: direct reprogramming of fibroblasts into myocardial-like cells using extracellular vesicles secreted by cardiomyocytes

To investigate the promoting effect of extracellular vesicles derived from myocardial cells (CM-EVs) on the reprogramming of cardiac fibroblasts (CFs) into cardiomyocyte-like cells (iCMs) and their therapeutic effect on myocardial infarction (MI) in rats. Cell experiments: The differential adhesion method was used to obtain Sprague Dawley (SD) suckling rat CFs and cardiomyocytes (CMs), while the ultracentrifugation method was used to obtain CM-EVs. Transmission electron microscopy and nanoparticle tracking technology were used to analyze and determine the morphology and particle size of CM-EVs. Western blotting was used to identify the expression of EV markers CD9, CD63, and Alix proteins. Small molecule combination of CHIR99021, Forskolin, Dorsomorphin, SB431542, and Valproic acid (CFDSV) and CFDSV + CM-EVs combination were used to induce CFs to differentiate into cardiomyocytes. The expression of cellular morphological changes, myocardial-specific protein cardiac troponin T (cTnT), and α-actinin were detected on the 3rd, 6th, 9th, and 15th day of reprogramming, respectively. After transfection and inhibition of miRNA-133, immunofluorescence, RT-qPCR, and Western blotting techniques were used to detect the expression of cTnT and α-actinin of induced CFs in the CMs group (CM-EVs), miRNA-133 high expression group (133H), and miRNA-133 inhibition group (133I). Animal experiment: CM-EVs were injected into the margin of myocardial infarction in rats. Cardiac function was detected by echocardiography before and 4 weeks after infarction, and the pathological changes were detected by HE and Masson staining, while Tunel and CD31 fluorescence staining were used to detect myocardial cell apoptosis and angiogenesis. CFs in the CM-EVs group expressed cTnT and α-actinin after induction, and the expression intensity gradually increased with the extension of induction time. On the 15th day after induction, cTnT-positive cells accounted for 85.6% of the total cell count, while the CFDSV group accounted for 48.8%. The majority of cells expressed GATA-binding protein 4 (GATA4), NK2 homeobox 5 (Nkx-2.5), and connexin 43 (Cx43). The RT-qPCR analysis showed the induced CFs expressed mature cardiomyocyte markers, including cTnT, Ryr2, Nkx-2.5, and GATA, which were similar to those of CMs (P < 0.05). Upon induction of CFs into iCMs, iCMs expressed cardiac precursor cell markers, such as source domain transcription factor-1 (Isl-1), mesodermal posterior spiral transcription factor-1 (Mesp-1), GATA4, and fetal liver kinase-1 (Flk-1). RT-qPCR, Western blotting, and immunofluorescence results showed that cTnT and α-actinin were highly expressed in CFs induced by CM-EVs group and 133H group until the 15th day, while the expression levels were low in cont group and 133I group. In animal in vivo experiments, injection of CM-EVs was found to alleviate myocardial fibrosis and reduce apoptosis of myocardial cells in the infarcted area compared to the MI group (P < 0.001). Moreover, there was an increase in capillary density. Results showed a significant improvement in left ventricular ejection fraction and fractional shortening after 4 weeks of CM-EVs injection (P < 0.01). CM-EVs can enhance the reprogramming efficiency of CFs into iCMs, effectively alleviate myocardial fibrosis, resist cell apoptosis, increase angiogenesis, and improve heart function after myocardial infarction. MiRNA-133 plays an important regulatory role in this process.

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

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

Comparative Analysis of the Therapeutic Potential of Extracellular Vesicles Secreted by Aged and Young Bone Marrow-Derived Mesenchymal Stem Cells in Osteoarthritis Pathogenesis

Osteoarthritis (OA), a joint disease, burdens global healthcare due to aging and obesity. Recent studies show that extracellular vesicles (EVs) from bone marrow-derived mesenchymal stem cells (BMSCs) contribute to joint homeostasis and OA management. However, the impact of donor age on BMSC-derived EV efficacy remains underexplored. In this study, we investigated EV efficacy from young BMSCs (2-month-old) in mitigating OA, contrasting them with EVs from aged BMSCs (27-month-old). The study used destabilisation of the medial meniscus (DMM) surgery on mouse knee joints to induce accelerated OA. Cartilage degeneration markers and senescence markers' expression levels were investigated in response to EV treatment. The therapeutic impact of EVs on chondrocytes under inflammatory responses was also evaluated. Despite having similar morphologies, EVs from young BMSCs markedly decreased senescence and improved chondroprotection by activating the PTEN pathway while simultaneously suppressing the upregulation of the PI3K/AKT pathways, proving to be more effective than those from older BMSCs in vitro. Furthermore, intraperitoneal injections of EVs from young donors significantly mitigated OA progression by preserving cartilage and reducing synovitis in a surgical OA model using DMM in mice. These findings highlight that donor age as a critical determinant in the therapeutic potential of BMSC-derived EVs for clinical use in OA treatment.

Healing the Cornea: Exploring the Therapeutic Solutions Offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

Oncolytic viruses alter the biogenesis of tumor extracellular vesicles and influence their immunogenicity

Extracellular vesicles (EVs) are mediators of intercellular communication in the tumor microenvironment. Tumor EVs are commonly associated with metastasis, immunosuppression or drug resistance. Viral infections usually increase EV secretion, but little is known about the effect of oncolytic viruses (OVs) on tumor EVs. Here, we investigated the impact of oncolytic vesicular stomatitis virus (VSV) and vaccinia virus on EVs secreted by human melanoma and thoracic cancer cells. We found that OV infection increases the production of EVs by tumor cells. These EVs contain proteins of viral origin, such as VSV-G, thus creating a continuum of particles sharing markers of both canonical EVs and viruses. As such, the presence of VSV-G on EVs improves the transfer of their protein content to cell types commonly found in the tumor microenvironment. A proteomic analysis also revealed that EVs-OV secreted during VSV infection are enriched in immunity-related proteins. Finally, CD8+ T cells incubated with EVs-OV from infected cells display slightly enhanced cytotoxic functions. Taken together, these data suggest that OVs enhance the communication mediated by tumor EVs, which could participate in the therapeutic efficacy of OVs. These results also provide rationale for engineering OVs to exploit EVs and disseminate therapeutic proteins within the tumor microenvironment.

Bovine PMN responses to extracellular vesicles released by Besnoitia besnoiti tachyzoites and B. besnoiti-infected host cells

Bovine besnoitiosis is a re-emerging cattle disease caused by the apicomplexan parasite Besnoitia besnoiti, which severely affects individual animal welfare and profitability in cattle industry. We recently showed that B. besnoiti tachyzoite exposure to bovine polymorphonuclear neutrophils (PMN) effectively triggers neutrophil extracellular trap (NET) formation, leading to parasite immobilization hampering host cell infection. So far, the triggers of this defense mechanism remain unclear. Emerging evidence indicates that extracellular vesicles (EVs) modulate PMN effector functions, such as ROS production or NET formation. Therefore, we tested whether exposure of bovine PMN to EVs from different cellular sources affects classical PMN effector functions and cytokine/chemokine secretion. EVs were isolated from B. besnoiti-infected and non-infected host cells (bovine umbilical vein endothelial cells, BUVEC), from tachyzoite-exposed bovine PMN and from B. besnoiti tachyzoites. EV concentration and size was determined by Nano-Flow cytometry and EV nature was confirmed by both classical EV markers (CD9 and CD81) and transmission electron microscopy (TEM). Overall, PMN stimulation with both BUVEC- and tachyzoite-derived EVs significantly induced extracellular DNA release while EVs from PMN failed to affect NET formation. BUVEC and tachyzoite EV-driven NET formation was confirmed microscopically by the presence of DNA decorated with neutrophil elastase (NE) and histones in typical NET structures. Moreover, confocal microscopy revealed EVs to be internalized by bovine PMN. Referring to PMN activation, EVs from the different cellular sources all failed to affect glycolytic or oxidative responses of bovine PMN as detected by Seahorse®-based analytics and luminol-based chemoluminescence, thereby denying any role of NADPH oxidase (NOX) activity in EV-driven NET formation. Finally, exposure to B. besnoiti-infected BUVEC-derived EVs induced IL-1β and IL-6 release, but failed to drive CXCL8 release of bovine PMN. Hence, we overall demonstrated that EVs of selected cellular origin owned the capacity to trigger NOX-independent NET formation, were incorporated by PMN and selectively fostered IL-1β and IL-6 release.

iTRAQ proteomic analysis of exosomes derived from synovial fluid reveals disease patterns and potential biomarkers of Osteoarthritis

Exosomes extracted from synovial fluid (SF-exo) reflect the status of their originating cells. The proteomic profiles of SF-exo are important for the diagnosis of osteoarthritis (OA). To delineate the proteomic differences between SF-exo from OA patients and healthy individuals, a quantitative proteomic study based on iTRAQ technology was performed. In this study, a total of 439 proteins were identified, with 20 proteins exhibiting increased expression in the OA patient group, while 5 showed decreased expression levels. Bioinformatic analysis showed these differentially expressed proteins (DEPs) were involved in a variety of immune-related processes, including complement activation and antigen binding. For further screening, we downloaded a publicly available dataset of synovial fluid (PXD023708) and compared it with our dataset. The comparative Results identified that 5 DEPs overlapped in two datasets, and protein-protein interaction revealed that C3, C4B and APOM were key members of a tightly interactive network. Through receiver operating characteristic (ROC) curve analysis and enzyme-linked immunosorbent assay (ELISA), we confirmed 5 DEPs (C3, C4B, APOM, MMP3, DPYSL2) as potential diagnostic biomarkers for OA. And Pearson correlation analysis confirmed that most of these biomarkers had no significant linear correlation with age. Overall, our study provides the first comprehensive description of the proteomic landscape of SF-exo in OA and identifies several potential biomarkers. These findings are expected to provide valuable insights into the diagnosis and treatment of OA.

Exosomal signaling in cancer metastasis: Molecular insights and therapeutic opportunities

Exosomes are membrane-bound extracellular vesicles that play a role in exchanging biological products across membranes and serve as intermediaries in intercellular communication to maintain normal homeostasis. Numerous molecules, including lipids, proteins, and nucleic acids are enclosed in exosomes. Exosomes are constantly released into the extracellular environment and exhibit distinct characteristics based on the secreted cells that produce them. Exosome-mediated cell-to-cell communication has reportedly been shown to affect multiple cancer hallmarks, such as immune response modulation, pre-metastatic niche formation, angiogenesis, stromal cell reprogramming, extracellular matrix architecture remodeling, or even drug resistance, and eventually the development and metastasis of cancer cells. Exosomes can be used as therapeutic targets and possible diagnostic biomarkers by selectively loading oncogenic molecules into them. We highlight the important roles that exosomes play in cancer development in this review, which may lead to the development of fresh approaches for future clinical uses.

Efficient Enzymatic Glycan Engineering of Extracellular Vesicles Using Nanomaterial-Interfaced Microfluidics

Extracellular vesicles (EVs) present a promising modality for numerous biological and medical applications, including therapeutics. Developing facile methods to engineer EVs is essential to meeting the rapidly expanding demand for various functionalized EVs in these applications. Herein, we developed a technology that integrates enzymatic glycoengineering and microfluidics for effective EV functionalization. This method builds on a 3D nanostructured microfluidic device to streamline a multiple-step EV engineering process, which involves a step of enzymatic reaction to install azido-sialic acid residues to glycans on EVs using a sialyltransferase and an azide-tagged sialyl donor followed by the attachment of various functionalities, such as biotin and fluorescent labels, to the resulting azido-glycans on EVs through a biocompatible click reaction. Compared to traditional EV engineering methods, we show that our technology improves the efficiency of EV glycoengineering while simplifying and expediting the workflow. Furthermore, we demonstrated the applicability of this technology to EVs derived from the cell lines of different cancer types, including A549, PC3, and COLO-1 cells. Overall, this EV engineering technology could provide a potentially useful tool for broad applications.