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

Extracellular Vesicles in Renal Inflammatory Diseases: Revealing Mechanisms of Extracellular Vesicle-Mediated Macrophage Regulation

Renal inflammatory diseases are a group of severe conditions marked by significant morbidity and mortality. Extracellular vesicles (EVs), as facilitators of intercellular communication, have been recognized as pivotal regulators of renal inflammatory diseases, significantly contributing to these conditions by modulating immune responses among other mechanisms. This review highlights the intricate mechanisms through which EVs modulate macrophage-kidney cell interactions by regulating macrophages, the principal immune cells within the renal milieu. This regulation subsequently influences the pathophysiology of renal inflammatory diseases such as acute kidney injury and chronic kidney disease. Furthermore, understanding these mechanisms offers novel opportunities to alleviate the severe consequences associated with renal inflammatory diseases. In addition, we summarize the therapeutic landscape based on EV-mediated macrophage regulatory mechanisms, highlighting the potential of EVs as biomarkers and therapeutic targets as well as the challenges and limitations of translating therapies into clinical practice.

Quantification of Urine and Plasma Levels of Extracellular Vesicles in a Cohort of Kidney Transplant Recipients and Chronic Kidney Disease Patients

Extracellular vesicles (EVs) have a key role in intercellular communication. We hypothesized that EVs are biomarkers of nephropathy or kidney allograft rejection. We screened patients with chronic kidney disease (CKD) and kidney transplant (KT) recipients. We measured the urine and plasma levels of total EVs overall and EV subpopulations (positive for podocalyxin, aquaporin-1, CD133, CD144, CD19, CD3, CD16, CD56, or CD41). We included 92 patients with CKD, 70 KT recipients, and 33 healthy volunteers. In CKD, the total urine EV concentration was correlated positively with the estimated glomerular filtration rate (eGFR), but none of the subpopulations was identified as a potential biomarker of nephropathy. Among the KT recipients, 30 had good allograft function and 40 had allograft disease (13 with antibody-mediated rejections (ABMR), 12 with T-cell-mediated rejection (TCMR), and 15 with allograft dysfunction). Patients with ABMR had low plasma levels of EVs derived from B-cells, T-cells, and endothelium (p = 0.003, 0.009, and 0.005, respectively). Patients with TCMR had a low urine level of EVs derived from endothelium (p = 0.05). EVs derived from B-cells, T-cells, and endothelium might be biomarkers of kidney allograft rejection. However, we did not identify biomarkers of nephropathy in CKD.

Detection of Human Circulating and Extracellular Vesicle-Derived miRNAs in Serum of Humanized Mice Transplanted with Human Breast Cancer (HER2+ and TNBC) Cells-A Proof of Principle Investigation

Humanized tumor mice (HTM) allow for preclinical cancer treatment studies of breast cancer (BC) under human-like conditions. This study utilized HTM for the first time to investigate potential miRNA biomarker candidates for treatment response in sera and extracellular vesicles (EVs), following X-irradiation and atezolizumab (anti-PD-L1) treatment. We identified the changes of human-specific miRNAs (miR-23b-3p and miR-155-5p) after irradiation and anti-PD-L1 treatment in HTMs with human epidermal growth factor receptor 2 positive (HER2+ BC) and triple-negative breast cancer (TNBC). The high degree of conserved, circulating free miRNA in mice and men represents a challenge of our assay; however, miRNAs with ≥2 nucleotide mismatches can be employed for human-specific analysis, and even conserved miRNAs may be utilized under clearly defined conditions of human tumor growth in HTM. A comparative analysis of extracellular vesicle miRNA cargo and free-circulating serum miRNAs revealed several exosome-specific miRNAs (miR-29b-3p, miR-34c-5p, miR-203a-3p, miR-378g, and miR-382-5p) in HTMs, which are known to play roles in BC. Our findings demonstrate that HTMs are a suitable model to identify treatment-induced changes in free-circulating and exosomal miRNAs that influence tumor progression and immunological tumor defense, both locally and at distant sites. This study presents a proof-of-principle approach to analyzing cell-free nucleotides and exosomes in a human-like, preclinical in vivo setting. Further refinements are necessary to enhance the sensitivity and the specificity of the HTM-based approach.

Characterization of size distribution and markers for mosquito extracellular vesicles

Extracellular vesicles (EVs) are non-replicative, cell-derived membranous structures secreted by potentially all eukaryotic cells, playing a crucial role in intercellular communication. The study of EVs requires approaches and tools, which have predominantly been developed for mammalian models. Here, we undertook a multimodal characterization of mosquito EVs to provide a technical and knowledge foundation for their study. First, using a cell line model from Aedes aegypti and applying multiple analytical technologies (i.e., NTA, TEM, cryo-EM, and AFM), we observed that mosquito EVs range from 20 to 500 nm in diameter and that a majority are smaller than 100 nm. Second, we showed that smaller EVs are secreted in mosquito saliva. Third, we evaluated the capacity of differential centrifugation and size exclusion chromatography to separate mosquito EVs, revealing the strengths and weaknesses of each technology. Finally, we identified a mosquito homolog of CD63 as an extravesicular marker and the mosquito syntenin as a putative luminal marker. Overall, our results promote the development of tools and approaches for the study of mosquito EVs.

Reduction of alternative polarization of macrophages by short-term activated hepatic stellate cell-derived small extracellular vesicles

BACKGROUND

Activated hepatic stellate cells (HSCs) induce alternative (M2) polarization of macrophages and contribute to the progression of fibrosis and hepatocellular carcinoma (HCC). However, the effects of small extracellular vesicles released by HSCs (HSC-sEVs) during activation remain largely unknown.

METHODS

The aim of this study was to investigate the role of extracellular vesicles released by HSCs (HSC-sEVs) at different stages of activation in macrophage polarization. The effects of sEVs from short-term activated and long-term activated HSCs on liver macrophages was studied. Small RNA sequencing analyses were performed to obtain differential miRNAs transported by the short-term and long-term activated HSC- sEVs. The in vivo effects of short-term activated HSC-sEV-specific miRNA on liver macrophage and liver fibrosis were confirmed in a CCl4-induced liver injury mouse model. To study the tumor suppressive effects of the macrophages educated by short-term activated HSC-sEV-specific miRNA, human hepatoma cells were mixed and subcutaneously cotransplanted with miR-99a-5p mimic-pretreated macrophages.

RESULTS

We found that consistent with activated HSCs, long-term activated HSC-sEVs (14dHSC-sEVs) induce bone marrow-derived monocytes (MOs) toward an M2 phenotype, but short-term activated HSC-sEVs (3dHSC-sEVs) induce the resident macrophages (Kupffer cells, KCs) toward a classically activated (M1) phenotype. We identified five 3dHSC-sEV-specific miRNAs, including miR-99a-5p. In vitro and in vivo experiments support that miR-99a-5p negatively regulates alternative polarization of macrophages, decreases collagen deposition in chronic liver injury model, and suppresses the progression of hepatoma in a xenograft model partially by targeting CD93.

CONCLUSION

Collectively, our work reveals an unexpected proinflammatory role of 3dHSC-sEVs, preliminarily explores the underlying mechanism, and evaluates the therapeutic potential of 3dHSC-sEV-specific miR-99a-5p for liver fibrosis and tumorigenesis.

Isolation and characterization of extracellular vesicles from EGFR mutated lung cancer cells

The epidermal growth factor receptor (EGFR) signaling pathway is essential for cellular processes such as proliferation, survival, and migration. Dysregulation of EGFR signaling is frequently observed in non-small cell lung cancer (NSCLC) and is associated with poor prognosis. This study aims to isolate and characterize extracellular vesicles (EVs) released by mutant EGFR lung cancer cell line PC9 and compare them with wild-type EGFR lung cancer cell line A549, while also evaluating the effect of gefitinib treatment on EV secretion and cargo composition. The two lung cancer cell lines were cultured with 2% EV-free serum, and EVs were subsequently isolated by differential ultra centrifugation. EVs were characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) for quantification size and shape determination. Western blot analysis confirmed the enrichment and purity of isolated EVs. Results showed that EGFR mutation significantly increased EV release and altered their size, compared to EVs released by wild-type EGFR cells. In addition to classical EV markers such as CD81, Flotillin- 1, and TSG101, Western blot analysis also detected phosphorylated EGFR (p-EGFR) selectively packaged into EVs from PC9 cells. Gefitinib treatment significantly reduced EV secretion in PC9 cells and led to a marked decrease in p-EGFR incorporation into EVs, indicating that EV biogenesis and compostion are modulated by active EGFR signaling. In conclusion, this study highlights the significant influence of EGFR activation on EV secretion and cargo composition while demonstrating that EGFR inhibition via gefitinib alters EV-mediated signaling in lung cancer cells. These findings provide insights into tumor behavior, EV-mediated oncogenic communication, and the potential use of EVs as biomarkers and therapeutic targets in NSCLC.

FRET imaging of glycoRNA on small extracellular vesicles enabling sensitive cancer diagnostics

Glycosylated RNAs (glycoRNAs), a recently discovered class of membrane-associated glyco-molecules, remain poorly understood in function and clinical value due to limited detection methods. Here, we show a dual recognition Förster resonance energy transfer (drFRET) strategy using nucleic acid probes to detect N-acetylneuraminic acid-modified RNAs, enabling sensitive, selective profiling of glycoRNAs on small extracellular vesicles (sEVs) from minimal biofluids (10 μl initial biofluid). Using drFRET, we identify 5 prevalent sEV glycoRNAs derived from 7 cancer cell lines. In a 100-patient cohort (6 cancer types and non-cancer controls), sEV glycoRNA profiles achieve 100% accuracy (95% confidence interval) in distinguishing cancers from non-cancer cases and 89% accuracy in classifying specific cancer types. Furthermore, drFRET reveal that sEV glycoRNAs specifically interact with Siglec proteins and P-selectin, which is critical for sEV cellular internalization. The drFRET strategy provides a versatile and sensitive platform for the imaging and functional analysis of sEV glycoRNAs, with promising implications for clinical applications.

Most L1CAM Is not Associated with Extracellular Vesicles in Human Biofluids and iPSC-Derived Neurons

Transmembrane L1 cell adhesion molecule (L1CAM) is widely used as a marker to enrich for neuron-derived extracellular vesicles (EVs), especially in plasma. However, this approach lacks sufficient robust validation. This study aimed to assess whether human biofluids are indeed enriched for EVs, particularly neuron-derived EVs, by L1CAM immunoaffinity, utilizing multiple sources (plasma, CSF, conditioned media from iPSC-derived neurons [iNCM]) and different methods (mass spectrometry [MS], nanoparticle tracking analysis [NTA]). Following a systematic multi-step validation approach, we confirmed isolation of generic EV populations using size-exclusion chromatography (SEC) and polymer-aided precipitation (PPT)-two most commonly applied EV isolation methods-from all sources. Neurofilament light (NfL) was detected in both CSF and blood-derived EVs, indicating their neuronal origin. However, L1CAM immunoprecipitation did not yield enrichment of L1CAM in EV fractions. Instead, it was predominantly found in its free-floating form. Additionally, MS-based proteomic analysis of CSF-derived EVs also did not show L1CAM enrichment. Our study validates EV isolation from diverse biofluid sources by several isolation approaches and confirms that some EV subpopulations in human biofluids are of neuronal origin. Thorough testing across multiple sources by different orthogonal methods, however, does not support L1CAM as a marker to reliably enrich for a specific subpopulation of EVs, particularly of neuronal origin.

Stem-Cell Derived Exosomal microRNAs as Biomarkers and Therapeutics for Pediatric Cardiovascular Disease

Purpose of Review

In recent years, several pre-clinical studies have demonstrated the therapeutic potential of stem cell-derived exosomes in the treatment of cardiovascular disease (CVD). Here, we evaluate their potential as biomarkers for the detection and monitoring of CVD, with a particular focus on pediatric heart disease.

Recent Findings

Exosomes isolated from stem cell sources, including mesenchymal stem cells (MSCs) and pluripotent stem cells (PSCs), benefit cardiovascular function, inflammatory responses, and angiogenesis in injured and diseased hearts. These exosomes carry a variety of cargo, such as proteins, lipids, and nucleic acids. However, the majority contain non-coding RNA molecules.

Summary

Review of the existing literature for several non-coding RNAs and their relationship to CVD suggests that exosomes containing microRNAs (miRNAs) can serve as promising biomarkers for CVD due to their presence in circulation, ease of isolation, and therapeutic potential. These biomarkers are especially promising as screening and diagnostic tools for the early detection of pediatric and congenital heart disease.

MiR-148a-3p Loaded Human Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles Alleviates Silica-Induced Pulmonary Fibrosis by Inhibiting β-Catenin Signaling

Background

In clinical practice, due to the lack of typical symptoms and specific diagnostic biomarkers, silicotic patients often having already developed pulmonary fibrosis by the time of clinical diagnosis. Studies have demonstrated that human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hucMSC-EVs) could moderate silicosis fibrosis, which may be related to the microRNAs (miRNAs) in hucMSC-EVs. While the full extent of their antifibrotic effects and the underlying mechanisms remain to be elucidated.

Methods

HucMSC-EVs were administered from day 28 to day 56 after silica exposure in mice, which in a therapeutic manner. In addition, the antifibrotic abilities of engineered hucMSC-EVs with varying levels of miR-148a-3p, a miRNA with antifibrotic properties, were evaluated. Heat shock protein 90 beta family member 1 (Hsp90b1) is reported to be a target of miR-148a-3p, the protein-protein interaction analysis was used to explore its regulated downstream factors in lung fibrosis. The underlying mechanisms were also investigated by using miR-148a-3p mimics and small interfering RNA (siRNA) targeting Hsp90b1 in vitro.

Results

HucMSC-EVs could reduce the histopathological changes and the levels of fibrotic proteins in the mouse lung tissues when administered in a therapeutic manner. Meanwhile, miR-148a-3p-overexpressed hucMSC-EVs intervention exhibited the enhanced anti-fibrotic effect compared with the negative control intervention group. In vitro, the elevated level of miR-148a-3p in hucMSC-EVs was shown to enhance hucMSC-EVs' inhibition of fibroblast collagen hypersecretion, whereas a depressed level of miR-148a-3p in hucMSC-EVs partially counteracted the inhibitory effect. Moreover, the mechanistic investigations revealed that miR-148a-3p could blunt β-catenin signaling via targeting Hsp90b1 in fibroblasts.

Conclusion

This study demonstrated that hucMSC-EVs retain their antifibrotic properties in silicotic mice when administered in a therapeutic manner. Further, miR-148a-3p was confirmed to be an essential component within hucMSC-EVs, mediating their inhibition of silica-induced pulmonary fibrosis by reducing β-catenin signaling via targeting of Hsp90b1 in fibroblasts.

Extracellular Vesicles in Aging and Age-Related Diseases. How Important Are They?

Extracellular vesicles (EVs), lipid bilayer-bound particles secreted by cells, have attracted significant research attention for their roles in aging-related disorders, including cardiovascular disease, metabolic dysfunction, cancer, and neurodegeneration. Research shows that EV cargo and function are influenced by factors including age, disease state, exercise, nutrition and sleep, and they may modulate various aging-associated processes such as stem cell renewal, nutrient sensing, cell senescence, mitochondrial function, and insulin resistance. This perspective highlights, for a general audience, a selection of studies of EVs in aging and age-related diseases, and their diverse roles in organ crosstalk. While current evidence indicates that EVs play multiple roles in aging, there are numerous challenges including methodological challenges and limitations, heterogeneous reports of EV cargo, limited reproducibility, and apparent context-dependent effects of EVs and their cargo. Together, this limits the interpretation of these studies. This is proposed that EVs may act as fine-tuners of cellular communication within the broader aging-associated secretome and the importance of standardizing methods are emphasized. Last, future directions for EV research are suggested.

The roles of extracellular vesicles in mental disorders: information carriers, biomarkers, therapeutic agents

Mental disorders are complex conditions that encompass various symptoms and types, affecting approximately 1 in 8 people globally. They place a significant burden on both families and society as a whole. So far, the etiology of mental disorders remains poorly understood, making diagnosis and treatment particularly challenging. Extracellular vesicles (EVs) are nanoscale particles produced by cells and released into the extracellular space. They contain bioactive molecules including nucleotides, proteins, lipids, and metabolites, which can mediate intercellular communication and are involved in various physiological and pathological processes. Recent studies have shown that EVs are closely linked to mental disorders like schizophrenia, major depressive disorder, and bipolar disorder, playing a key role in their development, diagnosis, prognosis, and treatment. Therefore, based on recent research findings, this paper aims to describe the roles of EVs in mental disorders and summarize their potential applications in diagnosis and treatment, providing new ideas for the future clinical transformation and application of EVs.

Extracellular vesicles as precision therapeutics for psychiatric conditions: targeting interactions among neuronal, glial, and immune networks

The critical role of the immune system in brain function and dysfunction is well recognized, yet development of immune therapies for psychiatric diseases has been slow due to concerns about iatrogenic immune deficiencies. These concerns are emphasized by the lack of objective diagnostic tools in psychiatry. A promise to resolve this conundrum lies in the exploitation of extracellular vesicles (EVs) that are physiologically produced or can be synthetized. EVs regulate recipient cell functions and offer potential for EVs-based therapies. Intranasal EVs administration enables the targeting of specific brain regions and functions, thereby facilitating the design of precise treatments for psychiatric diseases. The development of such therapies requires navigating four dynamically interacting networks: neuronal, glial, immune, and EVs. These networks are profoundly influenced by brain fluid distribution. They are crucial for homeostasis, cellular functions, and intercellular communication. Fluid abnormalities, like edema or altered cerebrospinal fluid (CSF) dynamics, disrupt these networks, thereby negatively impacting brain health. A deeper understanding of the above-mentioned four dynamically interacting networks is vital for creating diagnostic biomarker panels to identify distinct patient subsets with similar neuro-behavioral symptoms. Testing the functional pathways of these biomarkers could lead to new therapeutic tools. Regulatory approval will depend on robust preclinical data reflecting progress in these interdisciplinary areas, which could pave the way for the design of innovative and precise treatments. Highly collaborative interdisciplinary teams will be needed to achieve these ambitious goals.

Modular and Nondisturbing Chimeric Adaptor Protein for Surface Chemistry of Small Extracellular Vesicles

Current chemical strategies for modifying the surface of extracellular vesicles (sEVs) often struggle to balance efficient functionalization with preserving structural integrity. Here, we present a modular approach for the surface modification of sEVs using a chimeric adaptor protein (CAP). The CAP was designed with three key features: a SNAP-tag for stable and modular binding, long and rigid linker to enhance spatial accessibility and conjugation efficiency, and the N-terminal sorting domain derived from syntenin to improve CAP expression on the sEV. We established a postsynthetic method to introduce diverse functional molecules onto sEVs, creating a versatile system termed "sEV-X" (where X represents an organic molecule, protein, or nanoparticle). Quantitative analyses at the single-molecule level revealed a linear relationship between CAP expression and the number of conjugated functional molecules, underscoring the importance of steric hindrance mitigation in sEV surface engineering. Moreover, antibody-conjugated sEVs as drug carriers, demonstrated significant tumor-specific delivery and therapeutic efficacy in a tumor-bearing mouse model, underscoring the potential of CAP-expressing sEVs as a customizable therapeutic vesicle. Overall, the CAP technology may serve as a universal platform for advancing the development of sEV-based therapeutics.

lncRNAs GAS5 and MALAT1 Contained in Human Adipose Stem Cell (hASC)-Derived Exosomes Drive the Cell-Free Repair and Regeneration of Wounds In Vivo

Wound healing progresses through four phases: hemostasis, inflammation, proliferation, and remodeling. Wounds may become chronic if this process is disrupted. The use of small extracellular vesicle (sEV; EVs < 200 nm) exosomes (exo; ~40-120 nm) derived from human adipose stem cells (hASCs) as a treatment for wounds is well studied. The cargo of these exosomes is of great interest as this accelerates wound healing. Our previous studies identified lncRNAs GAS5 and MALAT1 as packaged and enriched in hASC exosomes. In this study, we use a rat model to examine the effects on wound healing when hASC exosomes are depleted of GAS5 and MALAT1. Rats were wounded and wounds were treated with 100 μg hASCexo or hASCexo-G-M every 2 days for 1 week. qPCR was completed to evaluate the molecular effects of depletion of GAS5 and MALAT1 from hASCexo. RNAseq was performed on wound tissue to evaluate the molecular mechanisms changed by hASCexo-G-M in wound healing. While hASCexo-G-M significantly improved wound healing rate compared to control wounds, healing occurred slower than in wounds treated with hASCexo that were not depleted of GAS5 and MALAT1. Overall, this study reveals that molecular functions associated with healing are reduced in the absence of GAS5 and MALAT1, highlighting the importance of these lncRNAs.

Cyclophilin A and C are the Main Components of Extracellular Vesicles in Response to Hyperglycemia in BV2 Microglial Cells

Cyclophilins (Cyps) and CD147 receptor play a crucial role in the inflammatory responses. Chronic inflammation causes tissue damage and is a common condition of several inflammation-based pathologies as diabetes or Alzheimer´s disease. Under high glucose (HG) conditions, microglia is activated and releases inflammatory mediators. In this process the role of Cyps is unknown, so this study was aimed to investigate the profile of Cyps in microglia and their release through extracellular vesicles (EVs) under hyperglycemia. An increase in reactive oxygen species (ROS) and nitric oxide (NO) levels was observed when BV2 glia cells were incubated with HG concentration. These effects were mitigated by the Cyps inhibitor cyclosporine A (CsA), suggesting the implication of Cyps in BV2 activation. In these conditions the intracellular expression of CypA, B, C and D, as well as the membrane expression of CD147 receptor was increased. In addition, only CypA and CypC were detected in the extracellular medium. Then, the presence of Cyps inside EVs was explored as an alternative secretion route. Interestingly, under HG treatment, an increase in the levels of the four Cyps in EVs was observed. When neurons were treated with EVs derived from HG-treated glia cells, their viability was reduced and EVs were detected in cytosol neurons pointing to an EVs-Cyps neurotoxic effect. These findings provide novel insights into the relationship between Cyps and EVs in neuroinflammation in hyperglycemia conditions. The current results strengthen the role of Cyps in cell communication and its potential role in brain function under pathological conditions.

Enhancing Analysis of Extracellular Vesicles by Microfluidics

Extracellular vesicles (EVs) play crucial roles in intercellular communication and hold great promise as biomarkers for noninvasive disease diagnosis. Intensive research efforts have been devoted to discovering the EV subpopulations responsible for specific functions or with enhanced effectiveness as disease markers, through extensive EV purification and content analysis. However, their high heterogeneity in size and cargo composition poses significant challenges for reaching such goals. Isolation methods like ultracentrifugation and size-exclusion chromatography, as well as content analysis approaches like polymerase chain reaction and enzyme-linked immunosorbent assay, have made significant contributions to improving our understanding of EV biology. Nonetheless, these methods face limitations in isolation efficiency, EV purity, and detection sensitivity and specificity due to issues like large sample consumption, unsatisfactory purity, and insufficient resolution in EV subtyping. Microfluidic technology presents promising solutions to these challenges, leveraging their intrinsic capabilities in precise flow and external energy field manipulation, sample compartmentalization, and signal enhancement at the micro- and nanoscale. Hence, this review summarizes the recent developments in microfluidics-enabled EV analysis, paying special attention to the unique microfluidic features exploited. Strategies such as viscoelastic and inertial flow, fluid mixing, and external-field-assisted approaches in improving EV purification, as well as compartmentalization and micro/nanostructures for enhancing EV detection, are examined. Furthermore, the current limitations and potential future directions are discussed to inspire advancements in this rapidly developing field.

Menstrual blood serum extracellular vesicles reveal novel molecular biomarkers and potential endotypes of unexplained infertility

Several biomolecules have been previously associated with unexplained infertility (uIF) in blood and uterine samples, immune cells and their secreted factors, endometrial tissue, menstrual blood, serum, and stromal cells, however they do not comprehensively represent different uIF endotypes and their isolation/detection involves invasive diagnostic methods and lacks precision. This ex-vivo study was performed on extracellular vesicles (EVs) from menstrual blood collected on cycle day 2 from 9 fertile volunteers and 8 women with uIF. Menstrual blood serum (MBS) EVs were isolated from fertile and uIF MBS using Iodixanol Density Gradient Centrifugation and quantified by flow cytometry. EVs were characterized according to MISEV2023 guidelines. Comprehensive proteomic analysis of MBS EVs and EV-depleted MBS showed significant changes in uIF proteome, mostly affecting cell adhesion, immune response, apoptosis, response to oxidative stress and lipid metabolism. These processes were previously linked to pathologies of the female reproductive system but never investigated in uIF and were used to stratify patients into distinct molecular endotypes. Area under the curve (AUC) analysis was used to determine the optimum set of biomarkers for each of the uIF molecular endotypes. These findings provide new insights into uIF that could facilitate personalised treatment approaches.

Plasma Microvesicles May Contribute to Muscle Damage in the mdx Mouse Model of Duchenne Muscular Dystrophy

Extracellular vesicles (EVs) are cell-derived lipid-bound vesicles divided into apoptotic bodies, microvesicles (MVs), and exosomes based on their biogenesis, release pathway, size, content, and functions. EVs are intercellular mediators that significantly affect muscle diseases such as Duchenne muscular dystrophy (DMD). DMD is a fatal X-linked disorder caused by mutations in the dystrophin gene, leading to muscle degeneration. Mdx mice are the most commonly used model to study the disease, and in this study, we phenotypically characterized plasma MVs from mdx mice by flow cytometry. Furthermore, we assessed the ability of plasma MVs to modulate muscle inflammation, damage, and/or regeneration by intramuscular injection of MVs from mdx mice into mdx or DBA/2 mice as a control. In both mouse lineages, platelets and erythrocytes were the primary sources of MVs, and CD3+ CD4+ MVs were observed only in mdx mice. We also observed that plasma MVs from mdx mice induced muscle damage in mdx mice but not in DBA/2 mice, while plasma MVs from DBA/2 mice did not induce muscle damage in either mouse lineage. These results indicate that plasma MVs from mdx are potentially pathogenic. However, this condition also depends on the muscular tissue status, which must be responsive due to active inflammatory or regenerative responses.

Advances in Plant-Derived Extracellular Vesicle Extraction Methods and Pharmacological Effects

Extracellular vesicles (EVs) are those with a double-membrane structure that contains proteins, lipids, nucleic acids, and other biologically active substances that play an important role in cell-cell and cell-environment communication. They have also become an important mechanism for exchanging biologically active substances for cellular molecules. As many studies on EVs have been conducted, plant-derived extracellular vesicles (PDEVs) have also started attracting attention. The biological activity and stability of PDEVs are closely related to the extraction and separation methods, and choosing a separation method that meets the requirements of PDEVs is important. The extraction methods of PDEVs include ultracentrifugation, ultrafiltration, size-exclusion chromatography, etc. In recent years, it has been found through research that PDEVs possess biological properties, such as anti-inflammatory, anti-cancer, and anti-infective properties, and that they show unique advantages as therapeutic agents and drug carriers. Therefore, we have collected the scientific literature related to EVs derived from more than a dozen fruits and vegetables, and summarized and analyzed their extraction, separation, and roles in disease treatment, aiming to provide reference and inspiration for the in-depth study of the efficacy of new drugs.

Fructose-2,6-bisphosphate restores TDP-43 pathology-driven genome repair deficiency in motor neuron diseases

TAR DNA-binding protein 43 (TDP-43) proteinopathy plays a critical role in neurodegenerative diseases, including amyotrophic lateral sclerosis and frontotemporal dementia (FTD). In our recent discovery, we identified that TDP-43 plays an essential role in DNA double-strand break (DSB) repair via the non-homologous end joining (NHEJ) pathway. Here, we found persistent DNA damage in the brains of ALS/FTD patients, primarily in the transcribed regions of the genome. We further investigated the underlying mechanism and found that polynucleotide kinase 3'-phosphatase (PNKP) activity was severely impaired in the nuclear extracts of both patient brains and TDP-43-depleted cells. PNKP is a key player in DSB repair within the transcribed genome, where its 3'-P termini processing activity is crucial for preventing persistent DNA damage and neuronal death. The inactivation of PNKP in ALS/FTD was due to reduced levels of its interacting partner, phosphofructo-2-kinase fructose 2,6 bisphosphatase (PFKFB3), and its biosynthetic product, fructose-2,6-bisphosphate (F2,6BP), an allosteric modulator of glycolysis. Recent work from our group has shown that F2,6BP acts as a positive modulator of PNKP activity in vivo. Notably, exogenous supplementation with F2,6BP restored PNKP activity in nuclear extracts from ALS/FTD brain samples and patient-derived induced pluripotent stem (iPS) cells harboring pathological mutations. Furthermore, we demonstrate that supplementation of F2,6BP restores genome integrity and partially rescues motor phenotype in a Drosophila model of ALS. Our findings underscore the possibility of exploring the therapeutic potential of F2,6BP or its analogs in TDP-43 pathology-associated motor neuron diseases.

Determination of the miRNA profile of extracellular vesicles from equine mesenchymal stem cells after different treatments

BACKGROUND

Osteoarthritis (OA) is a common and incurable disease in humans and animals. To gain a better understanding of the pathogenesis and identify potential treatments, miRNAs will be extracted and analysed from extracellular vesicles (EVs) of equine adipose derived mesenchymal stem cells (AdMSCs).

METHODS

For this purpose we cultivated and pretreated AdMSCs under different conditions: interleukin 1β, shock wave, chondrogenic differentiation, chondrogenic differentiation under hypoxia, or after senescence. After treatment, EVs were harvested from the cell culture supernatants. Next-generation sequencing (NGS) was used to sequence the miRNAs from the EVs.

RESULTS

A total of 89 miRNAs whose expression was significantly altered compared with that of an untreated negative control were identified. On average, 53 miRNAs were upregulated and 6 miRNAs were downregulated. Among others, the miRNAs eca-miR-101, eca-miR-143, eca-miR-145, eca-miR-146a, eca-miR-27a, eca-miR-29b, eca-miR-93, eca-miR-98, and eca-miR-221 were significantly increased after the stimulations, which, as known anti-inflammatory miRNAs, could be candidates for therapeutic use in the treatment of OA.

CONCLUSION

These results lay the foundation for further research into the significance and efficacy of these miRNAs so that this knowledge can be improved in further experiments and, ideally, translated into therapeutic use.

Extracellular Vesicles from Different Mesenchymal Stem Cell Types Exhibit Distinctive Surface Protein Profiling and Molecular Characteristics: A Comparative Analysis

The current medical need to respond to different diseases has sparked great interest in extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) due to their great regenerative potential and as drug carriers by playing a critical role in cell-cell communication. However, due to their heterogeneity, there is no standardized universal method for their identification and characterization, which limits their clinical application. This study, following the recommendations and methodologies proposed by MISEV2023 for the characterization of EVs, shows for the first time a detailed morphological, protein, and biochemical comparison between EVs derived from three different MSCs sources (placenta, endometrium, and dental pulp). The information obtained from the different applied assays suggests that there are substantial differences between one EVs source and another. It also offers valuable insights that provide the guidelines to ease their profiling and therefore improve their selection, in order to speed up their use and clinical application; additionally, the knowledge obtained from each characterization test could facilitate new researchers in the field to choose a specific cell source to obtain EVs and select the appropriate methods that provide the necessary information according to their requirements.

New Challenges and Opportunities: Extracellular Vesicles in Biological and Biochemical Processes

Cell-to-cell communication plays a crucial role in many processes, both in physiological and pathological assets [...].

Extracellular Vesicles in Asthma: Intercellular Cross-Talk in TH2 Inflammation

Asthma is a complex, multifactorial inflammatory disorder of the airways, characterized by recurrent symptoms and variable airflow obstruction. So far, two main asthma endotypes have been identified, type 2 (T2)-high or T2-low, based on the underlying immunological mechanisms. Recently, extracellular vesicles (EVs), particularly exosomes, have gained increasing attention due to their pivotal role in intercellular communication and distal signaling modulation. In the context of asthma pathobiology, an increasing amount of experimental evidence suggests that EVs secreted by eosinophils, mast cells, dendritic cells, T cells, neutrophils, macrophages, and epithelial cells contribute to disease modulation. This review explores the role of EVs in profiling the molecular signatures of T2-high and T2-low asthma, offering novel perspectives on disease mechanisms and potential therapeutic targets.

Extracellular vesicles: innovative cell-free solutions for wound repair

Chronic non-healing wounds are often associated with conditions such as diabetes and peripheral vascular disease, pose significant medical and socioeconomic challenges. Cell-based therapies have shown promise in promoting wound healing but have major drawbacks such as immunogenicity and tumor formation. As a result, recent research has shifted to the potential of extracellular vesicles (EVs) derived from these cells. EVs are nanosized lipid bilayer vesicles, naturally produced by all cell types, which facilitate intercellular communication and carry bioactive molecules, offering advantages such as low immunogenicity, negligible toxicity and the potential to be re-engineered. Recent evidence recognizes that during wound healing EVs are released from a wide range of cells including immune cells, skin cells, epithelial cells and platelets and they actively participate in wound repair. This review comprehensively summarizes the latest research on the function of EVs from endogenous cell types during the different phases of wound healing, thereby presenting interesting therapeutic targets. Additionally, it gives a critical overview of the current status of mesenchymal stem cell-derived EVs in wound treatment highlighting their tremendous therapeutic potential as a non-cellular of-the-shelf alternative in wound care.

Rapid isolation of extracellular vesicles from stem cell conditioned medium using osmosis-driven filtration

Extracellular vesicles (EVs) hold significant promise as biomarkers and therapeutics, yet their isolation remains challenging due to their low abundance and complex sample matrices. Here, we introduce EV-Osmoprocessor (EVOs), a novel device that leverages osmosis-driven filtration for rapid and efficient EV isolation. EVOs employs a high osmolarity polymer solution to concentrate EVs while simultaneously removing smaller contaminants. Compared to traditional methods such as ultracentrifugation and precipitation, EVOs offers speed and convenience, achieving a 50-fold volume reduction in under 2 h. Our results show that EVOs retained EVs and removed >99% albumin from the cell conditioned culture medium (CCM). The isolated EVs exhibited a particle size distribution centered around 140 nm, which was very similar to EVs isolated via precipitation or ultracentrifugation. The standalone EVOs process achieved a particle:protein ratio (EV purity) of ~107 particles/µg protein. Comprehensive characterization, including cryo-electron microscopy, validation of protein markers and known miRNA cargo confirmed the successful isolation of EVs. Functional assays, based on protection of cardiomyocytes from hypoxia/reoxygenation injury, demonstrated the bioactivity of EVOs-isolated EVs. Furthermore, we show that EVOs can be used to concentrate 30 ml of CCM into a 0.5 ml solution, which was then further processed with size-exclusion chromatography (SEC), improving EV purity to ~109 particles/µg protein. This work establishes EVOs as a promising tool for EV research and clinical applications, offering a streamlined approach to EV isolation with enhanced analytical performance.

Polycystins recruit cargo to distinct ciliary extracellular vesicle subtypes in C. elegans

Therapeutic use of tiny extracellular vesicles (EVs) requires understanding cargo loading mechanisms. Here, we use a modular proximity labeling approach to identify the cargo of ciliary EVs associated with the transient receptor potential channel polycystin-2 PKD-2 of C. elegans. Polycystins are conserved ciliary proteins and cargo of EVs; dysfunction causes polycystic kidney disease in humans and mating deficits in C. elegans. We discover that polycystins localize with specific cargo on ciliary EVs: polycystin-associated channel-like protein PACL-1, dorsal and ventral polycystin-associated membrane C-type lectins PAMLs, and conserved tumor necrosis factor receptor-associated factor (TRAF) TRF-1 and TRF-2. Loading of these components to EVs relies on polycystin-1 LOV-1. Our modular EV-TurboID approach can be applied in both cell- and tissue-specific manners to define the composition of distinct EV subtypes, addressing a major challenge of the EV field.

Application of plant-derived extracellular vesicles as novel carriers in drug delivery systems: a review

INTRODUCTION

Plant-derived extracellular vesicles (P-EVs) are nanoscale, lipid bilayer vesicles capable of transporting diverse bioactive substances, enabling intercellular and interspecies communication and material transfer. With inherent pharmacological effects, targeting abilities, high safety, biocompatibility, and low production costs, P-EVs are promising candidates for drug delivery systems, offering significant application potential.

AREAS COVERED

A comprehensive review of studies on P-EVs was conducted through extensive database searches, including PubMed and Web of Science, spanning the years 1959 to 2025. Drawing on animal and cellular model research, this review systematically analyzes the pharmacological activities of P-EVs and their advantages as drug delivery carriers. It also explores P-EVs' drug loading methods, extraction techniques, and application prospects, including their benefits, clinical potential, and feasibility for commercial expansion.

EXPERT OPINION

Establishing unified preparation standards and conducting a more comprehensive analysis of molecular composition, structural characteristics, and mechanisms of P-EVs are essential for their widespread application. Greater attention should be given to the potential synergistic or antagonistic effects between P-EVs as carriers and the drugs they deliver, as this understanding will enhance their practical applications. In conclusion, P-EVs-based drug delivery systems represent a promising strategy to improve treatment efficacy, reduce side effects, and ensure drug stability.

Anti-liver fibrotic effects of small extracellular vesicle microRNAs from human umbilical cord-derived mesenchymal stem cells and their differentiated hepatocyte-like cells

OBJECTIVE

The aim of this study is to identify therapeutic cargos within mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) for the treatment of liver fibrosis, a condition that poses significant health risks.

RESULTS

sEVs from human umbilical cord-derived MSCs (UCMSCs) and their differentiated hepatocyte-like cells (hpUCMSCs) were found to alleviate liver fibrosis in mouse models, reduce fibrogenic gene expression in the liver, and inhibit hepatic stellate cell (HSC) activation, a central driver of liver fibrosis, in vitro. Deep sequencing identified differentially abundant microRNAs (miRNAs) (high-abundance: 57, low-abundance: 22) in both UCMSC- and hpUCMSC-derived sEVs, compared to HeLa cell-derived sEVs, which lack anti-liver fibrotic activity. Functional enrichment analysis of the high-abundance sEV miRNA targets revealed their involvement in transcriptional regulation, apoptosis, and cancer-related pathways, all of which are linked to liver fibrosis and hepatocellular carcinoma. Notably, many of the top 10 most abundant miRNAs reduced pro-fibrotic marker levels in activated HSCs in vitro.

CONCLUSION

The therapeutic potential of the high-abundance miRNAs shared by UCMSC- and hpUCMSC-derived sEVs in treating liver fibrosis is highlighted.

Prognostic value of clinical parameters and exosomal lncRNA NEAT1_1 in MEN1-related non-functioning pancreatic neuroendocrine tumors

Non-functioning pancreatic neuroendocrine tumors (NF-pNETs) significantly contribute to the premature death of multiple endocrine neoplasia type 1 (MEN1) patients. Reliable prognostic markers are not yet available. MicroRNAs (miRNA) and long-non-coding (lnc) RNAs, transported by extracellular vesicles, are emerging as new prognostic tools. This study aimed to analyze the clinical characteristics, the exosomal-miRNA 451 (exo-miR451) and the lnc-RNA nuclear paraspeckle assembly transcript 1 (NEAT1_1, 3.7 kB) in the mild and aggressive courses of MEN1-NFpNET disease. Patient characteristics were assessed regarding an aggressive course of disease. In addition, exo-miR451 and exo-lnc-NEAT1_1 expression levels were quantified in serum by RT-qPCR and correlated with clinical data. Immunohistochemistry results of STAT3 (signal transducer and activator of transcription 3), regulated by NEAT1, were performed in NF-pNET tissue and correlated with exo-lnc-NEAT1_1 expression. Among 66 MEN1 patients with NF-pNETs, 13 (20%) had an aggressive disease course. No significant differences in patient characteristics were observed between those with aggressive (n = 13) and mild (n = 53) disease (all p > .5). Exosomal miRNA-451 was dysregulated in 55% (n = 23) of cases, showing a trend toward higher upregulation in the aggressive group (36% vs. 19%), although this difference was not statistically significant (p = .215). Exo-NEAT1_1 was overexpressed in 42% (16/38) of patients, without significant differences between groups (p = .0523). However, exo-NEAT1_1 expression strongly correlated with STAT3 immunohistochemical staining (p = .001). Although no prognostic marker could be identified, we show for the first time that the STAT3-NEAT1 pathway plays a role in MEN1-associated NF-pNET tumorigenesis.

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.

Role of mesenchymal stromal cell secretome on recovery from cellular senescence: an overview

Cellular senescence is intricately linked with numerous changes observed in the aging process, including the depletion of the stem cell pool and the decline in tissue and organ functions. Over the past three decades, efforts to halt and reverse aging have intensified, bringing rejuvenation closer to reality. Current strategies involve treatments using stem cells or their derivatives, such as the secretome. This article aims to highlight key points and evaluate the utilization of secretome derived from mesenchymal stromal cells (MSCs) as an antisenescent approach. Employing a quasi-systematic research approach, the authors conducted a comprehensive analysis based on a search algorithm targeting the in vitro effects of MSC-derived secretome on rescuing cells from a senescent state. Reviewing 39 articles out of 687 hits retrieved from PubMed and Scopus without a time limit, the authors synthesized information and identified common types of MSC-tissue sources utilized (including bone marrow-MSCs, umbilical cord-MSCs, iPSC-derived MSCs, adipose tissue-MSCs, dental pulp-MSCs, amniotic membrane-MSCs, placenta-MSCs, gingival-MSCs, urine-MSCs, and commercially available MSC lineages) from both human and other species (such as mice and rats). The authors also examined the forms of secretome tested (including conditioned media and extracellular vesicles), the cell types treated (MSCs or other cell types), methods/biomarkers of monitoring senescence/rejuvenation, and the mechanisms involved. Ultimately, this review underscores the proof-of-principle of the beneficial effects of MSC-derived secretome in reversing cellular senescence across various cell types. Such insights might aid the scientific community in designing improved in vitro and in vivo assays for future research and clinical validation of this promising cell-free therapy.

Bovine fecal extracellular vesicles: A novel noninvasive tool for understanding gut physiology and pathophysiology in calves

Dairy calf gut health is linked with development and future production. Fecal extracellular vesicles (fEV) have emerged as a noninvasive tool in elucidating gut physiology and pathophysiology. Because feces is a complex matrix, the enrichment of extracellular vesicles (EV) from ruminant or preruminant feces is difficult. Nevertheless, if enriched, they have great potential as a gut health diagnostic and monitoring tool in dairy calves. Therefore, this study aimed to devise a protocol to enrich and characterize fEV from preweaning calves. We developed an fEV enrichment method by combination of differential centrifugation and double size exclusion chromatography and then characterized the fEV from the healthy calves. The study also assessed sample storage conditions, and the results indicated that storing preprocessed fecal samples at -80°C effectively preserves EV without introducing additional nanoparticles. Finally, fEV from 10-d-old healthy and Cryptosporidium spp.-positive calves were enriched, and a comparative analysis of fEV characteristics between the 2 groups was performed. Characterization results on EV specific protein biomarkers, size profile, total protein content, zeta potential, and morphology clearly established the enrichment of fEV with the developed protocol. The fEV analysis for calves positive and negative for Cryptosporidium spp. revealed a significant decrease in average nanoparticle size and zeta potential values in Cryptosporidium spp.-infected calves. Furthermore, the enriched fEV carried protein and nucleic acid cargo which could be further analyzed for other biomarkers to predict the gut physiology and pathophysiology of calves. In conclusion, our study has successfully optimized a protocol to enrich high purity grade EV from calf feces and displayed potential diagnostic application as a noninvasive tool.

Microscopic messengers: Extracellular vesicles shaping gastrointestinal health and disease

The field of extracellular vesicles (EVs) is advancing rapidly, and this review aims to synthesize the latest research connected to EVs and the gastrointestinal tract. We will address new and emerging roles for EVs derived from internal sources such as the pancreas and immune system and how these miniature messengers alter organismal health or the inflammatory response within the GI tract. We will examine what is known about external EVs from dietary and bacterial sources and the immense anti-inflammatory, immune-modulatory, and proliferative potential within these nano-sized information carriers. EV interactions with the intestinal and colonic epithelium and associated immune cells at homeostatic and disease states, such as necrotizing enterocolitis (NEC) and inflammatory bowel disease (IBD) will also be covered. We will discuss how EVs are being leveraged as therapeutics or for drug delivery and conclude with a series of unanswered questions in the field.

Exosomes and tissue engineering: A novel therapeutic strategy for nerve regenerative

Damage to nerves negatively impacts quality of life and causes considerable morbidity. Self-regeneration is a special characteristic of the nervous system, yet how successful regeneration is accomplished remains unclear. Research on nerve regeneration is advancing and accelerating successful nerve recovery with potential new approaches. Eukaryote cells release extracellular vesicles (EVs), which control intercellular communication in both health and disease. More and more, EVs such as microvesicles and exosomes (EXOs) are being recognized as viable options for cell-free therapies that address complex tissue regeneration. The present study highlights the functional relevance of EVs in regenerative medicine for nerve-related regeneration. A subclass of EVs, EXOs were first identified as a way for cells to expel undesirable cell products. These nanovesicles have a diameter of 30-150 nm and are secreted by a variety of cells in conditions of both health and illness. Their benefits include the ability to promote endothelial cell growth, inhibit inflammation, encourage cell proliferation, and regulate cell differentiation. They are also known to transport functional proteins, metabolites, and nucleic acids to recipient cells, thus playing a significant role in cellular communication. EXOs impact an extensive array of physiological functions, including immunological responses, tissue regeneration, stem cell conservation, communication within the central nervous system, and pathological processes involving cardiovascular disorders, neurodegeneration, cancer, and inflammation. Their biocompatibility and bi-layered lipid structure (which shields the genetic consignment from deterioration and reduces immunogenicity) make them appealing as therapeutic vectors. They can pass through the blood brain barrier and other major biological membranes because of their small size and membrane composition. The creation of modified EXOs is a dynamic area of research that supports the evaluation of diverse therapeutic freights, improvement of target selectivity, and manufacturing optimization.

Rapid identification of extracellular vesicles in basal tears using transmission electron microscopy

PURPOSE

To describe basal human tear components in negative staining with real-time transmission electron microscopy and identify extracellular vesicles using immunogold labeling.

METHODS

Basal tears of 13 healthy human subjects were collected using microcapillary glass tubes, negatively stained, and observed by transmission electron microscopy. Anti-CD63 immunogold labeling was also performed to confirm the nature of elements morphologically suggestive of extracellular vesicles.

RESULTS

Human tears were rich in cup-shaped vesicular structures, identified as extracellular vesicles by immunogold labeling. These vesicles were highly heterogeneous in morphology and size. Filamentous structures 200 to 700nm in length, presumed to be structures composed of phospholipids or mucopolysaccharides, were also observed.

CONCLUSIONS

Two main structures were observed in human basal tears of healthy subjects, mostly extracellular vesicles. To improve applicability and translation from the laboratory bench to the hospital bedside, we provide a quick and feasible workflow for real-time analysis of human tears using transmission electron microscopy. Analysis of vesicle richness and morphology in tears could help for detecting biomarkers of ocular and systemic disease.

Exploring the Adhesion Properties of Extracellular Vesicles for Functional Assays

The ‛stickiness' of extracellular vesicles (EVs) can pose challenges for EV processing and storage, but adhesive properties may also be exploited to immobilise EVs directly on surfaces for various measurement techniques, including super-resolution microscopy (SRM). Direct adhesion to surfaces may allow the examination of broader populations of EVs than molecular affinity approaches, which can also involve specialised, expensive affinity reagents. Here, we report on the interaction of EVs with borosilicate glass and quartz coverslips and on the effects of pre-coating coverslips with poly-L-lysine (PLL), a reagent commonly used to facilitate interactions between negatively charged surfaces of cells and amorphous surfaces. Additionally, we compared two mounting media conditions for SRM imaging and used immobilised EVs for a B-cell interaction test. Our findings suggest that borosilicate glass coverslips immobilise EVs better than quartz glass coverslips. We also found that PLL is not strictly required for EV retention but contributes to the uniform distribution of EVs on borosilicate glass coverslips. Overall, these findings suggest that standard lab materials like borosilicate glass coverslips, with or without PLL, can be effectively used for the immobilisation of EVs in specific imaging techniques.

Development and optimization of an ex vivo model of corneal epithelium damage with 1-heptanol: Investigating the influence of donor clinical parameters and MSC-sEV treatment on healing capacity

PURPOSE

To develop and characterize a reproducible human corneal epithelial wound-healing model using 1-heptanol, and to investigate the healing potential of Bone Marrow-derived Mesenchymal Stromal Cell small Extracellular Vesicles (MSC-sEV) and the influence of donor characteristics on epithelial healing.

METHODS

Eighty-eight (n = 88) human corneoscleral tissues unsuitable for transplantation were employed. Corneal epithelial damage was induced with 1-heptanol and monitored every 24 h up to 96 h using fluorescein and trypan blue staining. Histological assessment was performed on untreated and damaged tissues. Damaged areas were measured with FIJI software, and healing rates were calculated. MSC-sEV were isolated with size exclusion chromatography and characterized for their size, morphology and biomarkers. Their impact on healing was assessed in both in vitro scratch assays on cultured human corneal epithelial cells and on ex vivo 1-heptanol-damaged corneas.

RESULTS

Histological analysis revealed detached corneal epithelium in the central area, while other layers remained unaffected. Healing rate peaked at 48 h post-damage. Trypan blue and Fluorescein staining correlated and the former highlighted a higher initial healing rate than the latter. Diabetic and heart-beating brain-deceased donors showed impaired healing rates. MSC-sEV (79.8 nm, spherical bilayer, positive for TSG101, CD9, CD63, and CD81) significantly improved epithelial wound healing in both in vitro and ex vivo models.

CONCLUSION

1-heptanol effectively induces reproducible corneal epithelial damage, and the ex vivo organ-cultured human cornea heals the epithelium within 96 h. Diabetes and donation from heart-beating brain-deceased donors reduce healing capacity. MSC-sEV boost epithelial repair in damaged corneas.

Bimodal In Situ Analyzer for Circular RNA in Extracellular Vesicles Combined with Machine Learning for Accurate Gastric Cancer Detection

Circular RNAs in extracellular vesicles (EV-circRNAs) are gaining recognition as potential biomarkers for the diagnosis of gastric cancer (GC). Most current research is focused on identifying new biomarkers and their functional significance in disease regulation. However, the practical application of EV-circRNAs in the early diagnosis of GC is yet to be thoroughly explored due to the low accuracy of EV-circRNAs analysis. In this study, a hybridization chain reaction system based on rectangular DNA framework guidance and constructing a bimodal EV-circRNA in situ analyzer (BEISA) is developed. The analyzer can provide dual signal outputs in the fluorescence and electrochemical modes, enabling a self-correcting detection mechanism that significantly improves the accuracy of the assay. It has a broad detection range and an extremely low limit of detection. In a clinical cohort study, the BEISA used four circRNAs as biomarkers, combining them with machine learning for multiparametric analysis, which effectively differentiated between healthy donors and patients with early-stage GC. It is believed that the BEISA, in conjunction with machine learning technology, provides an efficient, sensitive, and reliable tool for EV-circRNA analysis, aiding in the early diagnosis of GC.

MSC exosomes and MSC exosomes loaded with LncRNA H19 as nanotherapeutics regulate the neurogenetic potential of Müller Glial Cells in dry age-related macular degeneration

In retinal degeneration diseases such as dry age-related macular degeneration (AMD), Müller Glial Cells (MGCs) in mammals undergo a process of reactive gliosis leading to the progression of dry AMD. Here, It is demonstrated that exosomes derived from mesenchymal stem cells (MSC exosomes) and MSC exosomes loaded with LncRNA H19, acting as nanotherapeutics, can be regulated by MGCs in dry AMD. In the in vivo study, MSC exosomes were administered via intravitreal injection. MSC exosomes effectively redirected MGCs from gliosis to dedifferentiation and alleviated MGCs-to-epithelial transition by inhibiting oxidative stress in mice with dry AMD induced by NaIO3. In the in vitro study, MSC exosomes promoted MGCs dedifferentiation by activating Wnt/β-catenin signaling pathway and prevented oxidative stress-induced MGCs gliosis and MGCs-to-epithelial transition by inhibiting TGFβ1 signaling pathway. MSC exosomes loaded with LncRNA H19 enhanced the activation of Wnt/β-catenin signaling pathway and the inhibition of the TGFβ1 signaling pathway compared with MSC exosomes. These results suggest that MSC exosomes regulate the neurogenetic potential of MGCs by redirecting MGCs from gliosis to dedifferentiation and alleviating the transformation of MGCs to epithelial cells through regulating oxidative stress. Regulating LncRNA H19 in MGCs to promote mammalian retinal regeneration in dry AMD was suggested for the first time.

New therapeutic strategies for malaria

Malaria is a life-threatening parasitic disease and remains a significant global health problem, associated with high morbidity and mortality. Malaria cases are widely spread, but the highest incidence occurs in tropical and subtropical areas, especially in developing countries. Despite all efforts to control the disease, the number of cases increased by 5 million from 2021 to 2022. The mechanisms of malaria pathogenesis are still not fully understood. This, combined with the parasite's recurrent ability to develop resistance to standard treatments, hinders effective disease management and control. Therefore, a deep understanding of parasite biology, along with the various aspects of host-parasite interactions, is essential for malaria elimination. Extracellular vesicles (EVs) are membrane-enclosed vesicles which are secreted by a variety of cells. These tiny structures have emerged as a key component in the mechanisms of pathogenesis of different parasitic diseases, promoting cell-to-cell communication, even in distance. In this review, we explore the latest advancements in EV research in the malaria field, focusing on their role in pathophysiology, as well as their potential as diagnostic tools, alternative therapeutic strategies, and vaccine development. We conclude by highlighting key elements in EV research that could provide insights into the translational application of EVs.

Yersinia pestis Actively Inhibits the Production of Extracellular Vesicles by Human Neutrophils

Yersinia pestis is the etiologic agent of the plague. A hallmark of plague is subversion of the host immune response by disrupting host signalling pathways required for inflammation. This non-inflammatory environment permits bacterial colonization and has been shown to be essential for disease manifestation. Previous work has shown that Y. pestis inhibits phagocytosis and degranulation by neutrophils. Manipulation of these key vesicular trafficking pathways suggests that Y. pestis influences extracellular vesicle (EV) secretion, cargo selection, trafficking and/or maturation. Our goals were to define the EV population produced by neutrophils in response to Y. pestis and determine how these vesicles might influence inflammation. Towards these goals, EVs were isolated from human neutrophils infected with Y. pestis or a mutant lacking bacterial effector proteins known to manipulate host cell signalling. Mass spectrometry data revealed that cargoes packaged in EVs isolated from mutant infected cells were enriched with antimicrobial and cytotoxic proteins, contents which differed from uninfected and Y. pestis infected cells. Further, EVs produced in response to Y. pestis lacked inflammatory properties observed in those isolated from neutrophils responding to the mutant. Together, these data demonstrate that Y. pestis actively inhibits the production of antimicrobial EVs produced by neutrophils, likely contributing to immune evasion.

A Simple Modification Results in a Significant Improvement in Measuring the Size of Extracellular Vesicles

OBJECTIVE

Size distribution is an important biophysical property of extracellular vesicles (EVs). EVs include small EVs (s-EVs) and large EVs (l-EVs) by size. Differential ultracentrifugation (dUC) is widely used to separate EVs from biofluids, but it can precipitate large impurity particles. Dynamic light scattering (DLS) is a simple and fast method for analyzing the size distribution of EVs. However, this approach is nonideal for heterogeneous and polydisperse samples since a small quantity of large impurity particles can markedly disturb the DLS results. Here, we developed a simple method to improve the reliability of DLS measurements.

METHODS

Plasma was obtained from 13 volunteers. The plasma was first processed by dUC to obtain crude l-EVs. The crude l-EVs were filtered with syringe filters (pore size of 1 μm and membrane material of hydrophilic polyvinylidene fluoride (PVDF)) to remove large impurity particles from l-EVs. The size distributions of the crude l-EVs and filtered l-EVs were measured via DLS.

RESULTS

After the samples were filtered, the coefficients of variation of the hydrodynamic radius and Peak 1 intensity of the filtered l-EVs decreased from 20.39% (12.76-28.96%) and 20.44% (14.58-28.32%) to 3.05% (1.79-4.72%) and 3.43% (1.76-5.88%), respectively, compared with those of the crude l-EVs.

CONCLUSION

These findings suggest that filtration can effectively separate circulating l-EVs in plasma to remove large impurity particles and make samples suitable for characterization by DLS. Our findings provide a simple method to improve precision via DLS to measure the size distribution of EVs.

Cardiac fibroblast-derived mitochondria-enriched sEVs regulate tissue inflammation and ventricular remodeling post-myocardial infarction through NLRP3 pathway

Resident cardiac fibroblasts (CFs) play crucial roles in sensing injury signals and regulating inflammatory responses post-myocardial infarction (MI). Damaged mitochondria can be transferred extracellularly via various mechanisms, including extracellular vesicles (EVs). In this study, we aimed to investigate whether CFs could transfer damaged mitochondrial components via small EVs (sEVs) and elucidate their role in regulating inflammatory responses post-MI. Left anterior descending coronary artery ligation was performed in mice. Mitochondrial components in sEVs were detected using nanoflow cytometry. Differential protein expression in sEVs from normoxia and normoglycemia CFs (CFs-Nor-sEVs) and CFs post oxygen-glucose deprivation (CFs-OGD-sEVs) was identified using label-free proteomics. CFs-sEVs were co-cultured with mouse bone marrow-derived macrophages (BMDMs) to assess macrophage inflammatory responses. Effects of intramyocardial injection of CFs-sEVs were assessed in MI mice in the absence or presence of NLRP3 inhibitor CY-09. Results demonstrated that mitochondrial components were detected in CFs-derived sEVs post-MI. Damaged mitochondrial components were enriched in CFs-OGD-sEVs (CFs-mt-sEVs), which promoted pro-inflammatory phenotype activation of BMDMs in vitro. Myocardial injection of CFs-mt-sEVs enhanced tissue inflammation, aggravated cardiac dysfunction, and exacerbated maladaptive ventricular remodeling post-MI in vivo. Mechanistically, above effects were achieved via activation of NLRP3 and above effects could be reversed by NLRP3 inhibitor CY-09. This study indicates that CFs could transfer damaged mitochondrial components via the sEVs post-MI, promote macrophage inflammatory activation and exacerbate maladaptive ventricular remodeling post MI by activating NLRP3. Our findings highlight the potential therapeutic effects of inhibiting CFs-mt-sEVs and NLRP3 to improve cardiac function and attenuate ventricular remodeling post-MI.

Building a digital library on research into mineralizing vesicles: a systematic review-based approach

This systematic review consolidates current research on mineralizing extracellular vesicles, or matrix vesicles (MVs), including their isolation, characterization, and role in physiological and pathological calcification. We searched PubMed/Medline, Scopus, and Web of Knowledge by employing the keywords "matrix vesicles" or "collagenase-released matrix vesicles" or "mineralizing vesicles" and publishing years from 2000 to 2023. Seventy-one studies met the inclusion criteria. The studies described different experimental protocols, especially with respect to methods for isolating MVs, wherein digestion with collagenase combined with centrifugation was the most used. The studies employed characterization techniques, including the determination of alkaline phosphatase (ALP) and transmission electron microscopy (TEM), to assess the functionality, size, and morphology of MVs. MVs contain key proteins such as ALP, annexins, and osteocalcin, along with calcium and phosphate ions, which are all critical for precipitating apatite. In the studies, evaluation of ALP activity revealed that MVs are more effective for mineralization than their parent cells and, hence, a valuable tool to regenerate bone and to engineer tissues. On the other hand, MVs play an essential role in pathologies, and the studies showed how they contribute to vascular calcification. Despite the therapeutic potential of MVs, isolation methods and characterization protocols vary across the studies, so standardized methods are needed. We have consolidated the data resulting from this systematic review in an open digital library on MVs with free access to all researchers. The users of the digital library can apply filters and taxonomy to find and interconnect the data resulting from the review.

Extracellular particles: emerging insights into central nervous system diseases

Extracellular particles (EPs), including extracellular vesicles (EVs) and non-vesicular extracellular particles (NVEPs), are multimolecular biomaterials released by cells that play a crucial role in intercellular communication. Recently, new subtypes of EPs associated with central nervous system (CNS), such as exophers and supermeres have been identified. These EPs provide new perspectives for understanding the pathological progression of CNS disorders and confer potential diagnostic value for liquid biopsies in neurodegenerative diseases (NDs). Moreover, EPs have emerged as promising drug delivery vehicles and targeted platforms for CNS-specific therapies. In this review, we delineate the landscape of EP subtypes and their roles in the pathophysiology of CNS diseases. We also review the recent advances of EP-based diagnosis in NDs and highlight the importance of analytical platforms with single-particle resolution in the exploitation of potential biomarkers. Furthermore, we summarize the application of engineered EVs in the treatment of CNS diseases and outline the underexplored potential of NVEPs as novel therapeutic agents.

Extracellular vesicles and the tumour microenvironment

Extracellular vesicles (EVs), tiny packages of information released by cells, are well established as being involved in unwanted cell-to-cell communication in cancer. EVs from cancer cells have been associated with the spread of drug resistance, immune suppression, and metastasis. Additional to cancer cells, the tumour microenvironment (TME) involves many cell types -including immune cells, fibroblasts, and endothelial cells, each of which has a potential role in how tumours grow, spread, and respond (or otherwise) to therapy. This review collates and distils research developments regarding the role of EVs in multi-way communication between cells in the TME. Further research including tailored clinical studies are now warranted to determine how best to prevent this extensive adverse communication occurring and/or how best to exploit it for biomarker discovery and as a therapeutic approach, in the interest of patients and also for economic benefit.

Plasma extracellular vesicles carry immune system-related peptides that predict human longevity

Extracellular vesicles (EVs) play crucial roles in aging. In this National Institutes on Aging-funded study, we sought to identify circulating extracellular vesicle (EV) biomarkers indicative of longevity. The plasma EV proteome of 48 older adults (mean age 77.2 ± 1.7 years [range 72-80]; 50% female, 50% Black, 50% < 2-year survival, 50% ≥ 10-year survival) was analyzed by high-resolution mass spectrometry and flow cytometry. The ability of EV peptides to predict longevity was evaluated in discovery (n = 32) and validation (n = 16) datasets with areas under receiver operating characteristic curves (AUCs). Longevity-associated large EV (LEV) plasma subpopulations were mainly related to immune cells (HLA-ABC+, CD9+, and CD31+) and muscle cells (MCAD+ and RyR2+). Of 7960 identified plasma EV peptides (519 proteins), 46.4% were related to the immune system and 10.1% to muscle. Compared with short-lived older adults, 756 EV peptides (131 proteins) had a higher abundance, and 130 EV peptides (78 proteins) had a lower abundance in long-lived adults. Among longevity-associated peptides, 437 (58 proteins) were immune system related, and 12 (2 proteins) were muscle related. Using just three to five plasma EV peptides (mainly complement components C2-C6), we achieved high predictive accuracy for longevity (AUC range 0.91-1 in a hold-out validation dataset). Our findings suggest that immune cells produce longevity-associated plasma EVs and elucidate fundamental mechanisms regulating aging and longevity. EV longevity predictors suggest there may be merit in targeting complement pathways to extend lifespan, for instance, with any one of the multiple complement inhibitors currently available or in clinical development.