Isolation and identification of exosomes from feline plasma, urine and adipose-derived mesenchymal stem cells

Exosomes in neurodegenerative diseases: Therapeutic potential and modification methods

In recent years, exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research. Exosomes are small and can effectively cross the blood-brain barrier, allowing them to target deep brain lesions. Recent studies have demonstrated that exosomes derived from different cell types may exert therapeutic effects by regulating the expression of various inflammatory cytokines, mRNAs, and disease-related proteins, thereby halting the progression of neurodegenerative diseases and exhibiting beneficial effects. However, exosomes are composed of lipid bilayer membranes and lack the ability to recognize specific target cells. This limitation can lead to side effects and toxicity when they interact with non-specific cells. Growing evidence suggests that surface-modified exosomes have enhanced targeting capabilities and can be used as targeted drug-delivery vehicles that show promising results in the treatment of neurodegenerative diseases. In this review, we provide an up-to-date overview of existing research aimed at devising approaches to modify exosomes and elucidating their therapeutic potential in neurodegenerative diseases. Our findings indicate that exosomes can efficiently cross the blood-brain barrier to facilitate drug delivery and can also serve as early diagnostic markers for neurodegenerative diseases. We introduce the strategies being used to enhance exosome targeting, including genetic engineering, chemical modifications (both covalent, such as click chemistry and metabolic engineering, and non-covalent, such as polyvalent electrostatic and hydrophobic interactions, ligand-receptor binding, aptamer-based modifications, and the incorporation of CP05-anchored peptides), and nanomaterial modifications. Research into these strategies has confirmed that exosomes have significant therapeutic potential for neurodegenerative diseases. However, several challenges remain in the clinical application of exosomes. Improvements are needed in preparation, characterization, and optimization methods, as well as in reducing the adverse reactions associated with their use. Additionally, the range of applications and the safety of exosomes require further research and evaluation.

Comprehensive Comparison of Methods for Isolation of Extracellular Vesicles from Human Plasma

Extracellular vesicles (EVs) are a vital component in cell-cell communication and hold significant potential as biomarkers and therapeutic carriers. Having a reproducible and simple EV isolation method for small volumes of human plasma is essential for biomarker discovery. Although combining multiple methods has been a recent trend in its ability to minimize contamination, it is not ideal for clinical specimens due to the large sample number and small sample volume. This study compared EVs isolated from 100 μL of plasma by nine commonly used methods based on different principles, including centrifugation, polymer precipitation, size exclusion, electrostatic interaction, and affinity enrichment. The isolated EVs were characterized by particle size and number using nanoparticle tracking analysis, purity, and contaminants using Simple Western and overall proteomic profiles using bottom-up proteomics. Despite the same EV enrichment principle, individual methods isolated EVs exhibited distinct characteristics, likely due to variations in the physicochemical properties of materials used and specific protocols. Overall, all of the methods evaluated are reproducible. MagNet and MagCap methods result in purer EVs with the narrowest size distribution and the highest proteome coverage but modest yield. This is the first report on isolating EVs from 100 μL of plasma using nine different methods with detailed characterization.

Equine adipose tissue-derived extracellular vesicles enhance adipose mesenchymal stem cell survival ex vivo

Adipose tissue-derived extracellular vesicles (ATEVs) have garnered attention for their roles in intercellular communication and regulation. This study presents the first investigation of equine adipose tissue, with ATEV being extracted concurrently during the isolation of adipose-derived mesenchymal stem cells (ADSCs). Through CCK-8 cell proliferation assays and scratch migration assays, a significant promotional effect of ATEV on ADSCs was observed, which not only accelerated the proliferation rate of the stem cells but also enhanced their migratory capacity. The application of Trypan Blue exclusion and live-dead cell staining further demonstrated the positive effects of ATEV on maintaining the viability of ADSCs during ex vivo storage. These findings provide new insights into the potential applications of ATEV in stem cell therapy, tissue repair, and regenerative medicine.

Human trabecular meshwork stem cell-derived small extracellular vesicles enhance trabecular meshwork cell survival and proliferation

Glaucoma is an optic neuropathy, one of the leading causes of irreversible blindness worldwide. Previous studies in animal models have shown that transplantation of trabecular meshwork stem cells (TMSCs-adult tissue-resident stem cells of TM) promotes TM regeneration and restores intraocular pressure through paracrine signaling. One of the major paracrine signal mediators is the extracellular vesicles. Given the advantages of sEV over cell-based therapies, the current work aims to investigate the potential of TMSC-derived small extracellular vesicles (sEV) in promoting TM cell survival and proliferation using in vitro experiments. TM cells were cultured in TM media and stem cell growth media (SCGM). Phenotypic and functional (sphere formation) characterization of cultured cells revealed that the SCGM maintained stemness with greater functional efficacy. sEV from TM cell (TM media) and TMSC (SCGM) conditioned media were isolated using the ultracentrifugation method. Characterization of sEV demonstrated that the sEV were within the size range of 30-200 nm and poly-dispersive spherical in shape. The TM and TMSC sEV express common exosomal marker syntenin, TM specific exosomal markers-emilin and neuropilin. To check the uptake specificity, the labelled sEV were incubated with different cell types. The varying degrees of uptake of the labelled sEV by TM cells, HLEB3 and 3T3 cell lines implied that TM and TMSC sEV might have varied surface components. The regenerative efficacy of the sEV was assessed in vitro by scratch wound assay, immunostaining for proliferation marker Ki67, and 5'-Bromo-2'-deoxyuridine incorporation assay. The TMSC sEV exhibited better wound healing efficacy by inducing TM cell proliferation. Furthermore, evaluation of the antioxidant potential depicted that the TMSC sEV enhanced TM cell viability under chronic oxidative stress by significantly reducing the intracellular reactive oxygen species. Taken together, our study demonstrated for the first time that the TMSC sEV enhanced TM cell proliferation as well as migration in vitro and attenuated oxidative stress-induced cell death by reducing intracellular reactive oxygen species. Further studies in animal models will pave the way for the potential application of TMSC sEV in glaucoma treatment.

Comparison of Methods for Isolating Exosomes from Plasma Subjects with Normal and High Fat Percentages

Adipose tissue is responsible for fat storage and is an important producer of extracellular vesicles (EVs). The biological content of exosomes, one kind of EV, provides information on aspects such as immunometabolic alterations. This study aimed to compare three plasma exosome isolation methods-using a commercial kit (CK), size exclusion chromatography (SEC), and differential centrifugation (DC)-and select the best one. Individuals categorized by normal and high body fat percentages were used. The DC and CK were proven to be the most advantageous out of the exosome isolation methods, so we suggest these methods for further protein and molecular analyses, respectively. Still, we emphasize the importance of selecting an appropriate methodology depending on the specific research objectives. At the same time, no statistical differences in exosome quality, morphology, total protein, or microRNA concentration were observed between individuals categorized by body fat percentage, so we suggest that the exosomal cargo varies in individuals with normal and high fat percentages.

Small Extracellular Vesicles from Breast Cancer Cells Induce Cardiotoxicity

Cardiovascular diseases and cancer are leading global causes of morbidity and mortality, necessitating advances in diagnosis and treatment. Doxorubicin (Doxo), a potent chemotherapy drug, causes long-term heart damage due to cardiotoxicity. Small extracellular vesicles (sEVs) carry bioactive molecules-such as proteins, lipids, and nucleic acids-that can modulate gene expression and signaling pathways in recipient cells, including cardiomyocytes. Through the delivery of cytokines, microRNAs, and growth factors, sEVs can influence cell survival, which plays a critical role in the development of cardiotoxicity. This study investigates the role of sEVs derived from breast cancer cells treated or not with Doxo and their potential to induce cardiomyocyte damage, thereby contributing to cardiotoxicity. We isolated sEVs from MCF-7 cells treated or not to Doxo using ultracentrifugation and characterized them through Nanoparticle Tracking Analysis (NTA), Scanning Electron Microscopy (SEM), and Western Blotting (WB) for the markers CD63, CD81, and TSG101. We analyzed cytokine profiles using a Multiplex Assay and Cytokine Membrane Array. We exposed Guinea pig cardiomyocytes to different concentrations of sEVs. We assessed their viability (MTT assay), shortening, reactive oxygen species (ROS-DHE dye) production, mitochondrial membrane potential (JC-1 dye), and calcium dynamics (FLUO-4 dye). We performed statistical analyses, including t-tests, ANOVA, Cohen's d, and η2 to validate the robustness of the results. Treatment of MCF-7 cells with 0.01 μM Doxorubicin resulted in increased sEVs production, particularly after 48 h of exposure (~1.79 × 108 ± 2.77 × 107 vs. ~5.1 × 107 ± 1.28 × 107 particles/mL, n = 3, p = 0.0019). These sEVs exhibited protein profiles in the 130-25 kDa range and 93-123 nm sizes. They carried cytokines including TNF-α, IL-1β, IL-4, IFN-γ, and IL-10. Exposure of cardiomyocytes to sEVs (0.025 μg/mL to 2.5 μg/mL) from both Doxo-treated and untreated cells significantly reduced cardiomyocyte viability, shortened cell length by up to 20%, increased ROS production, and disrupted calcium homeostasis and mitochondrial membrane potential, indicating severe cellular stress and cardiotoxicity. These findings suggest that Doxo enhances sEVs production from breast cancer cells, which plays a key role in cardiotoxicity through their cytokine cargo. The study highlights the potential of these sEVs as biomarkers for early cardiotoxicity detection and as therapeutic targets to mitigate cardiovascular risks in chemotherapy patients. Future research should focus on understanding the mechanisms by which Doxorubicin-induced sEVs contribute to cardiotoxicity and exploring their diagnostic and therapeutic potential to improve patient safety and outcomes in cancer therapy.

All-in-One Fusogenic Nanoreactor for the Rapid Detection of Exosomal MicroRNAs for Breast Cancer Diagnosis

Molecular-profiling-based cancer diagnosis has significant implications for predicting disease prognosis and selecting targeted therapeutic interventions. The analysis of cancer-derived extracellular vesicles (EVs) provides a noninvasive and sequential method to assess the molecular landscape of cancer. Here, we developed an all-in-one fusogenic nanoreactor (FNR) encapsulating DNA-fueled molecular machines (DMMs) for the rapid and direct detection of EV-associated microRNAs (EV miRNAs) in a single step. This platform was strategically designed to interact selectively with EVs and induce membrane fusion under a specific trigger. After fusion, the DMMs recognized the target miRNA and initiated nonenzymatic signal amplification within a well-defined reaction volume, thus producing an amplified fluorescent signal within 30 min. We used the FNRs to analyze the unique expression levels of three EV miRNAs in various biofluids, including cell culture, urine, and plasma, and obtained an accuracy of 86.7% in the classification of three major breast cancer (BC) cell lines and a diagnostic accuracy of 86.4% in the distinction between patients with cancer and healthy donors. Notably, a linear discriminant analysis revealed that increasing the number of miRNAs from one to three improved the accuracy of BC patient discrimination from 78.8 to 95.4%. Therefore, this all-in-one diagnostic platform performs nondestructive EV processing and signal amplification in one step, providing a straightforward, accurate, and effective individual EV miRNA analysis strategy for personalized BC treatment.

Therapeutic Application of Extracellular Vesicles Derived from Mesenchymal Stem Cells in Domestic Animals

Recently, the therapeutic potential of extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) has been extensively studied in both human and veterinary medicine. EVs are nano-sized particles containing biological components commonly found in other biological materials. For that reason, EV isolation and characterization are critical to draw precise conclusions during their investigation. Research on EVs within veterinary medicine is still considered in its early phases, yet numerous papers were published in recent years. The conventional adult tissues for deriving MSCs include adipose tissue and bone marrow. Nonetheless, alternative sources such as synovial fluid, endometrium, gingiva, and milk have also been intermittently used. Fetal adnexa are amniotic membrane/fluid, umbilical cord and Wharton's jelly. Cells derived from fetal adnexa exhibit an intermediate state between embryonic and adult cells, demonstrating higher proliferative and differentiative potential and longer telomeres compared to cells from adult tissues. Summarized here are the principal and recent preclinical and clinical studies performed in domestic animals such as horse, cattle, dog and cat. To minimize the use of antibiotics and address the serious issue of antibiotic resistance as a public health concern, they will undoubtedly also be utilized in the future to treat infections in domestic animals. A number of concerns, including large-scale production with standardization of EV separation and characterization techniques, must be resolved for clinical application.

The Omentum-A Forgotten Structure in Veterinary Surgery in Small Animals' Surgery

The greater and lesser omentum are derived from embryonic mesogastrium. The expansive greater omentum in dogs covers intestinal coils, while in cats, it is smaller. Comprising distinct portions, the greater omentum is rich in lymphatics and blood vessels. Conversely, the lesser omentum spans the liver, stomach, and duodenum. Studies on canine omentum reveal unique immune cell composition and regenerative potential attributed to adipose tissue-derived stromal cells (ADSCs). These cells hold promise in regenerative medicine, showing enhanced abilities compared with ADSCs from other sources. The omentum is critical in tissue repair and pathology, making it invaluable in veterinary surgery across various medical fields. The aim of this article was to research current knowledge about the applications of the omentum in veterinary surgery and the possibilities of using this structure in the future.

A method for extraction of exosomes from breast tumour cells and characterisation by transmission electron microscopy

Exosomes can not only be used as markers of tumour metastasis but also be used for noninvasive diagnosis of clinical diseases, which holds significant medical research value. Observing the morphology and distribution of exosomes using transmission electron microscopy (TEM) is highly significant. In this study, we use breast tumour cell (MDA-MB-231) exosomes as a representative sample and focus on the extraction and purification of exosomes, as well as the investigation of optimal conditions for the observation of exosomes using TEM. Through comparative tests, we obtained the optimal dilution concentration and staining method for TEM of exosomes, the best dilution concentration is 100 times, the best negative staining time is 1.5 min. Western blotting and scanning electron microscopy (SEM) confirmed the presence of exosome. The particle size experiment shows that the size of exosomes is mainly distributed between 60 nm and 150 nm. This method provides a reference for TEM sample preparation of subcellular structures and small molecular biomaterials other than exosomes.

Influence of the Anatomical Site on Adipose Tissue-Derived Stromal Cells' Biological Profile and Osteogenic Potential in Companion Animals

Adipose tissue-derived stromal cells (ADSCs) have generated considerable interest in the field of veterinary medicine, particularly for their potential in therapeutic strategies focused on bone regeneration. These cells possess unique biological characteristics, including their regenerative capacity and their ability to produce bioactive molecules. However, it is crucial to recognize that the characteristics of ADSCs can vary depending on the animal species and the site from which they are derived, such as the subcutaneous and visceral regions (SCAT and VAT, respectively). Thus, the present work aimed to comprehensively review the different traits of ADSCs isolated from diverse anatomical sites in companion animals, i.e., dogs, cats, and horses, in terms of immunophenotype, morphology, proliferation, and osteogenic differentiation potential. The findings indicate that the immunophenotype, proliferation, and osteogenic potential of ADSCs differ according to tissue origin and species. Generally, the proliferation rate is higher in VAT-derived ADSCs in dogs and horses, whereas in cats, the proliferation rate appears to be similar in both cells isolated from SCAT and VAT regions. In terms of osteogenic differentiation potential, VAT-derived ADSCs demonstrate the highest capability in cats, whereas SCAT-derived ADSCs exhibit superior potential in horses. Interestingly, in dogs, VAT-derived cells appear to have greater potential than those isolated from SCAT. Within the VAT, ADSCs derived from the falciform ligament and omentum show increased osteogenic potential, compared to cells isolated from other anatomical locations. Consequently, considering these disparities, optimizing isolation protocols becomes pivotal, tailoring them to the specific target species and therapeutic aims, and judiciously selecting the anatomical site for ADSC isolation. This approach holds promise to enhance the efficacy of ADSCs-based bone regenerative therapies.

Exosomal circNFIX promotes angiogenesis in ovarian cancer via miR-518a-3p/TRIM44 axis

Ovarian cancer (OC) is a gynecological cancer with high mortality. OC-derived exosomal circRNAs can regulate angiogenesis. This study aims to explore the role and mechanism of exosomal circRNA nuclear factor I X (CircNFIX) derived from OC cells in angiogenesis. Quantitative real-time polymerase chain reaction was employed to evaluate the levels of circNFIX, miR-518a-3p, and tripartite motif protein 44 (TRIM44) in OC and adjacent tissues. Exosomes from the ovarian surface epithelial cell (HOSEpiC) and OC cells (SKOV3 or OVCAR3) were isolated by differential centrifugation. Exosomes were cocultured with the human umbilical vein endothelial cells (HUVECs). The angiogenesis capacity was analyzed by Tube formation assay. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and Transwell assays were used to determine the cell viability and migration ability. The dual-luciferase report, RNA immunoprecipitation (RIP), and RNA pull-down assays were applied to validate the gene's interaction. CircNFIX and TRIM44 expression were higher and miR-518a-3p was lower in OC tissues than in the adjacent tissues. Upregulated circNFIX and TRIM44 were significantly correlated with the tumor size and International Federation of Gynecology and Obstetrics (FIGO) stage of OC patients. HUVECs treated OC-derived exosomes had higher proliferation, migration, and angiogenesis capacities than the control group. While OC-derived exosomal circNFIX silencing restrained HUVECs' proliferation, migration, and angiogenesis, compared with the OC-derived exosomes group. OC-derived exosomal circNFIX positively regulated TRIM44 expression by targeting miR-518a-3p in HUVECs. OC-derived exosomal circNFIX promoted angiogenesis by regulating the Janus-activated kinase/signal transducer and activator of transcription 1 (JAK/STAT1) pathway via miR-518a-3p/TRIM44 axis in HUVECs.

Urinary extracellular vesicles as a source of protein-based biomarkers in feline chronic kidney disease and hypertension

OBJECTIVES

To validate a methodology for isolating feline urinary extracellular vesicles and characterise the urinary extracellular vesicle population and proteome in cats with normal renal function and cats with normotensive or hypertensive chronic kidney disease.

METHODS

Feline urinary extracellular vesicles were isolated using three different methods (precipitation alone, precipitation followed by size exclusion chromatography and ultrafiltration followed by size exclusion chromatography, which were compared via transmission electron microscopy and nanoparticle tracking analysis. Cats with normal renal function (n=9), normotensive chronic kidney disease (n=10) and hypertensive chronic kidney disease (n=9) were identified and urinary extracellular vesicles isolated from patient urine samples via ultrafiltration followed by size exclusion chromatography. Extracellular vesicle size and concentration were determined using nanoparticle tracking analysis, and subsequently underwent proteomic analysis using liquid chromatography with tandem mass spectrometry to identify differences in protein expression between categories.

RESULTS

Urinary extracellular vesicle preparations contained particles of the expected size and morphology, and those obtained by ultrafiltration + size exclusion chromatography had a significantly higher purity (highest particle: protein ratio). The urinary extracellular vesicle proteomes contained extracellular vesicle markers and proteins originating from all nephron segments. Urinary extracellular vesicle concentration and size were unaffected by renal disease or hypertension. There were no differentially expressed proteins detected when comparing urinary extracellular vesicles derived from cats in the healthy category with the combined chronic kidney disease category, but five differentially expressed proteins were identified between the normotensive chronic kidney disease and hypertensive chronic kidney disease categories.

CLINICAL SIGNIFICANCE

Feline urinary extracellular vesicles can be successfully isolated from stored urine samples. Differentially expressed urinary extracellular vesicle proteins were discovered in cats with hypertensive chronic kidney disease, and warrant further investigation into their utility as biomarkers or therapeutic targets.

Extracellular Vesicles in Veterinary Medicine

Extracellular vesicles (EVs) are cell-derived membrane-bound vesicles involved in many physiological and pathological processes not only in humans but also in all the organisms of the eukaryotic and prokaryotic kingdoms. EV shedding constitutes a fundamental universal mechanism of intra-kingdom and inter-kingdom intercellular communication. A tremendous increase of interest in EVs has therefore grown in the last decades, mainly in humans, but progressively also in animals, parasites, and bacteria. With the present review, we aim to summarize the current status of the EV research on domestic and wild animals, analyzing the content of scientific literature, including approximately 220 papers published between 1984 and 2021. Critical aspects evidenced through the veterinarian EV literature are discussed. Then, specific subsections describe details regarding EVs in physiology and pathophysiology, as biomarkers, and in therapy and vaccines. Further, the wide area of research related to animal milk-derived EVs is also presented in brief. The numerous studies on EVs related to parasites and parasitic diseases are excluded, deserving further specific attention. The literature shows that EVs are becoming increasingly addressed in veterinary studies and standardization in protocols and procedures is mandatory, as in human research, to maximize the knowledge and the possibility to exploit these naturally produced nanoparticles.

Microbiome profiling of nasal extracellular vesicles in patients with allergic rhinitis

Background

Methods

Results

Conclusion

Adipose stem cells-released extracellular vesicles as a next-generation cargo delivery vehicles: a survey of minimal information implementation, mass production and functional modification

OBJECTIVES

To investigate current situation of minimal information implementation highlighted by minimal information for studies of extracellular vesicles 2018 (MISEV2018) guidelines, and explore technological advances towards mass production and functional modification in aesthetic, plastic and reconstructive surgery.

METHODS

Original articles on extracellular vesicles (EVs) of adipose stem cells (ASCs) were identified. Statistics upon minimal information for EVs research, such as species, cell types, culture conditions, conditioned media harvesting parameters, EVs isolation/storage/identification/quantification, functional uptake and working concentration, were analyzed.

RESULTS

The items of cell culture conditions such as passage number, seeding density, conditioned media harvesting time, functional uptake and working concentration were poorly documented, with a reporting percentage of 47.13%, 54.02%, 29.89%, 62.07% and 36.21%, respectively. However, there were some studies not reporting information of ASCs origin, culture medium, serum, EVs isolation methods, quantification and identification of EVs, accounting for 3.45%, 10.34%, 6.90%, 3.45%, 18.39% and 4.02%, respectively. Serum deprivation and trophic factors stimuli were attempted for EVs mass production. Several technological advances towards functional modification included hypoxia pre-condition, engineering EVs and controlled release. Presently, ASCs EVs have been applied in multiple fields, including diabetic/non-diabetic wound healing, angiogenesis, inflammation modulation, fat grafting, hair regeneration, antiaging, and healing and regeneration of cartilage/bone/peripheral nerve/tendon.

CONCLUSION

Our results highlight normative reporting of ASCs EVs in functional studies to increase reliability and reproducibility of scientific publications. The advances towards mass production and functional modification of ASCs EVs are also recommended to enhance therapeutic effects.