Specificities of exosome versus small ectosome secretion revealed by live intracellular tracking of CD63 and CD9

Polypeptide N-Acetylgalactosaminyl transferase 14 is a novel mediator in pancreatic β-cell function and growth

Polypeptide N-Acetylgalactosaminyl transferase 14 (GALNT14) plays important roles in cancer progression and chemotherapy response. Here, we show that GALNT14 is highly expressed in pancreatic β cells and regulates β cell function and growth. We found that the expression level of Ganlt14 was significantly decreased in the primary islets from three rodent type-2 diabetic models. Single-Cell sequencing defined that Galnt14 was mainly expressed in β cells of mouse islets. Galnt14 knockout (G14KO) INS-1 cell line, constructed by using CRISPR/Cas9 technology were growth normal, but showed blunt shape, and increased basal insulin secretion. Combined proteomics and glycoproteomics demonstrated that G14KO altered cell-to-cell junctions, communication, and adhesion. Insulin receptor (IR) and IGF1-1R were indirectly confirmed for GALNT14 substrates, contributed to diminished IGF1-induced p-AKT levels and cell growth in G14KO cells. Overall, this study uncovers that GALNT14 is a novel modulator in regulating β cells biology, providing a missing link of β cells O-glycosylation to diabetes development.

CRISPR/Cas12a and aptamer-chemiluminescence based analysis for the relative abundance determination of tumor-related protein positive exosomes for breast cancer diagnosis

Exosomes, as novel biomarker for liquid biopsy, exhibit huge important potential value for cancer diagnosis. However, various proteins show different expression levels on exosomal membrane, and the absolute concentration of exosomes in clinical samples is easily influenced by a number of factors. Here, we developed a CRISPR/Cas12a and aptamer-chemiluminescence based analysis (CACBA) for the relative abundance determination of tumor-related protein positive exosomes in plasma for breast cancer diagnosis. The total concentration of exosomes was determined through captured CD63 using a CRISPR/Cas12a-based method with the LoD of 8.97 × 103 particles/μl. Meanwhile, EpCAM and MUC1 positive exosomes were quantitatively detected by aptamer-chemiluminescence (ACL) based method with the LoD of 1.45 × 102 and 3.73 × 102 particles/μl, respectively. It showed that the percentages of EpCAM and MUC1 positive exosomes offered an excellent capability to differentiate breast cancer patients and healthy donors. The high sensitivity, strong specificity, outstanding anti-interference capability, and steady recovery rate of this approach offered higher accuracy and robustness than the commercialized method in clinical trial. In addition with good stability, easy preparation and low cost, this method not only provides a new approach to rapid analysis of exosome proteins, it may be quickly extended to the diagnoses of various cancers.

Circulating serum exosomes i-tRF-AspGTC and tRF-1-SerCGA as diagnostic indicators for non-small cell lung cancer

BACKGROUND

tRF-RNA-a representative of non-coding RNA (ncRNA)-is a precursor or fragment of mature tRNA and plays a crucial regulatory role in the occurrence and development of cancer. There is currently little research on tRF-RNA as a diagnostic marker in cancer, especially for NSCLC from serum exosomes.

METHOD

Serum exosomes were successfully extracted from serum; their physical morphology was captured by transmission electron microscopy (TEM); appropriate particle size detection was performed using qNano; surface labeling was verified through western blotting. Serum exosomes i-tRF-AspGTC and tRF-1-SerCGA were selected through gene microarray, and qPCR was used to validate their significance in 242 patients and 201 healthy individuals. The area under the curve (AUC) was used to evaluate the diagnostic indicators of non-small cell lung cancer (NSCLC).

RESULT

Compared with 201 healthy individuals, i-tRF-AspGTC and tRF-1-SerCGA were significantly downregulated in 242 NSCLC patients and 95 early-stage patients. For tRF-AspGTC and tRF-1-SerCGA, the predictive diagnostic efficiency rates of AUC were 0.690 and 0.680, respectively, whereas the early diagnostic efficiency rates were 0.656 and 0.688, respectively. The result of combined diagnosis with CEA and CYFRA21-1 was 0.928, and the early diagnostic efficiency was 0.843, which is a very high biological predictive factor for NSCLC.

CONCLUSION

The expression of serum exosomes i-tRF-AspGTC and tRF-1-SerCGA was significantly downregulated in NSCLC patients. These exosomes could be used as predictive indicators for diagnosis or early diagnosis of NSCLC.

Extracellular vesicles selective capture by peptide-functionalized hollow fiber membranes

Recently, membrane devices and processes have been applied for the separation and concentration of subcellular components such as extracellular vesicles (EVs), which play a diagnostic and therapeutic role in many pathological conditions. However, the separation and isolation of specific EV populations from other components found in biological fluids is still challenging. Here, we developed a peptide-functionalized hollow fiber (HF) membrane module to achieve the separation and enrichment of highly pure EVs derived from the culture media of human cardiac progenitor cells. The strategy is based on the functionalization of PSf HF membrane module with BPt, a peptide sequence able to bind nanovesicles characterized by highly curved membranes. HF membranes were modified by a nanometric coating with a copoly azide polymer to limit non-specific interactions and to enable the conjugation with peptide ligand by click chemistry reaction. The BPt-functionalized module was integrated into a TFF process to facilitate the design, rationalization, and optimization of EV isolation. This integration combined size-based transport of species with specific membrane sensing ligands. The TFF integrated BPt-functionalized membrane module demonstrated the ability to selectively capture EVs with diameter < 200 nm into the lumen of fibers while effectively removing contaminants such as albumin. The captured and released EVs contain the common markers including CD63, CD81, CD9 and syntenin-1. Moreover, they maintained a round shape morphology and structural integrity highlighting that this approach enables EVs concentration and purification with low shear stress. Additionally, it achieved the removal of contaminants such as albumin with high reliability and reproducibility, reaching a removal of 93%.

Exosomal mRNA Cargo are biomarkers of tumor and immune cell populations in pediatric osteosarcoma

Osteosarcoma is the commonest malignant bone tumor of children and adolescents and is characterized by a high risk of recurrence despite multimodal therapy, especially in metastatic disease. This suggests the presence of clinically undetected cancer cells that persist, leading to cancer recurrence. We sought to evaluate the utility of peripheral blood exosomes as a more sensitive yet minimally invasive blood test that could aid in evaluating treatment response and surveillance for potential disease recurrence. We extracted exosomes from the blood of pediatric osteosarcoma patients at diagnosis (n=7) and after neoadjuvant chemotherapy (n=5 subset), as well as from age-matched cancer-free controls (n=3). We also obtained matched tumor biopsy samples (n=7) from the cases. Exosome isolation was verified by CD9 immunoblot and characterized on electron microscopy. Profiles of 780 cancer-related transcripts were analysed in mRNA from exosomes of osteosarcoma patients at diagnosis and control patients, matched post-chemotherapy samples, and matched primary tumor samples. Peripheral blood exosomes of osteosarcoma patients at diagnosis were significantly smaller than those of controls and overexpressed extracellular matrix protein gene THBS1 and B cell markers MS4A1 and TCL1A. Immunohistochemical staining of corresponding tumor samples verified the expression of THBS1 on tumor cells and osteoid matrix, and its persistence in a treatment-refractory patient, as well as the B cell origin of the latter. These hold potential as liquid biopsy biomarkers of disease burden and host immune response in osteosarcoma. Our findings suggest that exosomes may provide novel and clinically-important insights into the pathophysiology of cancers such as osteosarcoma.

Rapid isolation of extracellular vesicles using covalent organic frameworks combined with microfluidic technique

Extracellular vesicles (EVs) are nano-sized lipid-membrane vesicles involved in intercellular communication and reflecting the physiological and pathological processes of their parental cells. Rapid isolation of EVs with low cost is an essential precondition for downstream function exploration and clinical applications. In this work, we designed a novel EVs isolation device based on the boronated organic framework (BOF) coated recyclable microfluidic chip (named EVs-BD) to separate EVs from cell culture media. Using a reactive oxygen species responsive phenylboronic ester compound, the highly porous BOF with a pore size in the range of 10-300 nm was prepared by crosslinking γ-cyclodextrin metal-organic frameworks. A mussel-inspired polydopamine (PDA)/polyethyleneimine (PEI) coating was employed to pattern BOF on the PDMS substrate of microfluidic channels. The EVs-BD was demonstrated to offer distinct advantages over the traditional ultracentrifugation method, such as operation simplicity and safety, reduced time and expense, and low expertize requirements. All things considered, a novel approach of EV acquisition has been successfully developed, which can be customized easily to meet the requirements of various EV-relevant research.

Laser-Patterning of Micromagnets for Immuno-Magnetophoretic Exosome Capture

Efficient isolation and patterning of biomolecules is a vital step within sample preparation for biomolecular analysis, with numerous diagnostic and therapeutic applications. For exosomes, nanoscale lipid-bound biomolecules, efficient isolation is challenging due to their minute size and resultant behavior within biofluids. This study presents a method for the rapid isolation and patterning of magnetically tagged exosomes via rationally designed micromagnets. Micromagnet fabrication utilizes a novel, scalable, and high-throughput laser-based fabrication approach that enables patterning at microscale lateral resolution (<50 µm) without lithographic processing and is agnostic to micromagnet geometry. Laser-based processing allows for flexible and tunable device configurations, and herein magnetophoretic capture within both an open-air microwell and an enclosed microfluidic system is demonstrated. Patterned micromagnets enhance localized gradient fields throughout the fluid medium, resulting in rapid and high efficiency magnetophoretic separation, with capture efficiencies nearing 70% after just 1s within open-air microwells, and throughputs upward of 3 mL h-1 within enclosed microfluidic systems. Using this microchip architecture, immunomagnetic exosome isolation and patterning directly from undiluted plasma samples is further achieved. Lastly, a FEA-based modeling workflow is introduced to characterize and optimize micromagnet unit cells, simulating magnetophoretic capture zones for a given micromagnet geometry.

Ultrasensitive quantification of PD-L1+ extracellular vesicles in melanoma patient plasma using a parallelized high throughput droplet digital assay

The expression of programmed death-ligand 1 (PD-L1) on extracellular vesicles (EVs) is an emerging biomarker for cancer, and has gained particular interest for its role mediating immunotherapy. However, precise quantification of PD-L1+ EVs in clinical samples remains challenging due to their sparse concentration and the enormity of the number of background EVs in human plasma, limiting applicability of conventional approaches. In this study, we develop a high-throughput droplet-based extracellular vesicle analysis (DEVA) assay for ultrasensitive quantification of EVs in plasma that are dual positive for both PD-L1 and tetraspanin (CD81) known to be expressed on EVs. We achieve a performance that significantly surpasses conventional approaches, demonstrating 360× enhancement in the limit of detection (LOD) and a 750× improvement in the limit of quantitation (LOQ) compared to conventional plate enzyme-linked immunoassay (ELISA). Underlying this performance is DEVA's high throughput analysis of individual EVs one at a time and the high specificity to targeted EVs versus background. We achieve a 0.006% false positive rate per droplet by leveraging avidity effects that arise from EVs having multiple copies of their target ligands on their surface. We use parallelized optofluidics to rapidly process 10 million droplets per minute, ∼100× greater than conventional approaches. A validation study on a cohort of 14 patients with melanoma confirms DEVA's ability to match conventional ELISA measurements with reduced plasma sample volume and without the need for prior EV purification. This proof-of-concept study demonstrates DEVA's potential for clinical utility to enhance prognosis as well as guide treatment for cancer.

Exosomes derived from hTERT-immortalized cells delay cellular senescence of human fibroblasts

hTERT gene therapies hold significant promise for treating age-related diseases. However, further research is required to address the challenges of delivery and ethical considerations. We hypothesized that exosomes derived from hTERT-immortalized cells could function similarly to hTERT gene therapies by maintaining telomere length and attenuating cellular senescence biomarkers. In this study, we overexpressed the hTERT gene in Human Foreskin Fibroblast-1 cells (HFF cells) to produce hTERT-immortalized HFF cells (hT-HFF cells). We then used exosomes derived from these hT-HFF cells to treat human fibroblasts, HFF cells. Our results demonstrated that these exosomes effectively attenuated biomarkers of cellular senescence in HFF cells. Furthermore, analysis revealed that hTERT mRNA was indeed packaged into the exosomes from hT-HFF cells. This mRNA was capable of elongating telomeres and delaying cellular senescence in HFF cells. Therefore, exosomes from hT-HFF cells show potential as a treatment for age-related diseases.

Enhancing extracellular vesicle cargo loading and functional delivery by engineering protein-lipid interactions

Naturally generated lipid nanoparticles termed extracellular vesicles (EVs) hold significant promise as engineerable therapeutic delivery vehicles. However, active loading of protein cargo into EVs in a manner that is useful for delivery remains a challenge. Here, we demonstrate that by rationally designing proteins to traffic to the plasma membrane and associate with lipid rafts, we can enhance loading of protein cargo into EVs for a set of structurally diverse transmembrane and peripheral membrane proteins. We then demonstrate the capacity of select lipid tags to mediate increased EV loading and functional delivery of an engineered transcription factor to modulate gene expression in target cells. We envision that this technology could be leveraged to develop new EV-based therapeutics that deliver a wide array of macromolecular cargo.

Intraluminal vesicle trafficking is involved in the secretion of base excision repair protein APE1

The apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) is an essential enzyme of the base excision repair pathway of non-distorting DNA lesions. In response to genotoxic treatments, APE1 is highly secreted (sAPE1) in association with small-extracellular vesicles (EVs). Interestingly, its presence in the serum of patients with hepatocellular or non-small-cell-lung cancers may represent a prognostic biomarker. The mechanism driving APE1 to associate with EVs is unknown, but is of paramount importance in better understanding the biological roles of sAPE1. Because APE1 lacks an endoplasmic reticulum-targeting signal peptide, it can be secreted through an unconventional protein secretion endoplasmic reticulum-Golgi-independent pathway, which includes an endosome-based secretion of intraluminal vesicles, mediated by multivesicular bodies (MVBs). Using HeLa and A549 cell lines, we investigated the role of endosomal sorting complex required for transport protein pathways (either-dependent or -independent) in the constitutive or trichostatin A-induced secretion of sAPE1, by means of manumycin A and GW 4869 treatments. Through an in-depth biochemical analysis of late-endosomes (LEs) and early-endosomes (EEs), we observed that the distribution of APE1 on density gradient corresponded to that of LE-CD63, LE-Rab7, EE-EEA1 and EE-Rab 5. Interestingly, the secretion of sAPE1, induced by cisplatin genotoxic stress, involved an autophagy-based unconventional secretion requiring MVBs. The present study enlightens the central role played by MVBs in the secretion of sAPE1 under various stimuli, and offers new perspectives in understanding the biological relevance of sAPE1 in cancer cells.

m6A modification inhibits miRNAs' intracellular function, favoring their extracellular export for intercellular communication

Epitranscriptomics represents a further layer of gene expression regulation. Specifically, N6-methyladenosine (m6A) regulates RNA maturation, stability, degradation, and translation. Regarding microRNAs (miRNAs), while it has been reported that m6A impacts their biogenesis, the functional effects on mature miRNAs remain unclear. Here, we show that m6A modification on specific miRNAs weakens their coupling to AGO2, impairs their function on target mRNAs, determines their delivery into extracellular vesicles (EVs), and provides functional information to receiving cells. Mechanistically, the intracellular functional impairment is caused by m6A-mediated inhibition of AGO2/miRNA interaction, the EV loading is favored by m6A-mediated recognition by the RNA-binding protein (RBP) hnRNPA2B1, and the EV-miRNA function in the receiving cell requires their FTO-mediated demethylation. Consequently, cells express specific miRNAs that do not impact endogenous transcripts but provide regulatory information for cell-to-cell communication. This highlights that a further level of complexity should be considered when relating cellular dynamics to specific miRNAs.

Role of aptamer technology in extracellular vesicle biology and therapeutic applications

Extracellular vesicles (EVs) are cell-derived nanosized membrane-bound vesicles that are important intercellular signalling regulators in local cell-to-cell and distant cell-to-tissue communication. Their inherent capacity to transverse cell membranes and transfer complex bioactive cargo reflective of their cell source, as well as their ability to be modified through various engineering and modification strategies, have attracted significant therapeutic interest. Molecular bioengineering strategies are providing a new frontier for EV-based therapy, including novel mRNA vaccines, antigen cross-presentation and immunotherapy, organ delivery and repair, and cancer immune surveillance and targeted therapeutics. The revolution of EVs, their diversity as biocarriers and their potential to contribute to intercellular communication, is well understood and appreciated but is ultimately dependent on the development of methods and techniques for their isolation, characterization and enhanced targeting. As single-stranded oligonucleotides, aptamers, also known as chemical antibodies, offer significant biological, chemical, economic, and therapeutic advantages in terms of their size, selectivity, versatility, and multifunctional programming. Their integration into the field of EVs has been contributing to the development of isolation, detection, and analysis pipelines associated with bioengineering strategies for nano-meets-molecular biology, thus translating their use for therapeutic and diagnostic utility.

Serum extracellular vesicle-derived miR-21-5p and miR-26a-5p as non-invasive diagnostic potential biomarkers for gastric cancer: A preliminary study

PURPOSE

Gastric cancer is the most common malignancy worldwide and is the third leading cause of cancer-related deaths, urgently requiring an early and non-invasive diagnosis. Circulating extracellular vesicles may emerge as promising biomarkers for the rapid diagnosis in a non-invasive manner.

METHODS

Using high-throughput small RNA sequencing, we profiled the small RNA population of serum-derived extracellular vesicles from healthy controls and gastric cancer patients. Differentially expressed microRNAs (miRNAs) were randomly selected and validated by reverse transcription-quantitative real-time polymerase chain reaction. Receiver operating characteristic curves were employed to assess the predictive value of miRNAs for gastric cancer.

RESULTS

In this study, 193 differentially expressed miRNAs were identified, of which 152 were upregulated and 41 were significantly downregulated. Among the differently expressed miRNA, the expression levels of miR-21-5p, miR-26a-5p, and miR-27a-3p were significantly elevated in serum-derived extracellular vesicles of gastric cancer patients. The miR-21-5p and miR-27a-3p were closely correlated with the tumor size. Moreover, the expression levels of serum miR-21-5p and miR-26a-5p were significantly decreased in gastric cancer patients after surgery.

CONCLUSIONS

The present study discovered the potential of serum miR-21-5p and miR-26a-5p as promising candidates for the diagnostic and prognostic markers of gastric cancer.

CD63 sorts cholesterol into endosomes for storage and distribution via exosomes

Extracellular vesicles such as exosomes are now recognized as key players in intercellular communication. Their role is influenced by the specific repertoires of proteins and lipids, which are enriched when they are generated as intraluminal vesicles (ILVs) in multivesicular endosomes. Here we report that a key component of small extracellular vesicles, the tetraspanin CD63, sorts cholesterol to ILVs, generating a pool that can be mobilized by the NPC1/2 complex, and exported via exosomes to recipient cells. In the absence of CD63, cholesterol is retrieved from the endosomes by actin-dependent vesicular transport, placing CD63 and cholesterol at the centre of a balance between inward and outward budding of endomembranes. These results establish CD63 as a lipid-sorting mechanism within endosomes, and show that ILVs and exosomes are alternative providers of cholesterol.

Parallel Analysis of Exosomes and Cytokines in Aqueous Humor Samples to Evaluate Biomarkers for Glaucoma

Recent emerging studies have demonstrated numerous critical roles of exosomes in cell-to-cell signaling. We investigated exosomes in the aqueous humor of glaucoma patients and controls and compared their characteristics with other biomarkers such as cytokines. Glaucoma patients exhibited higher exosome particle counts and smaller sizes compared to controls. Higher exosome density was correlated with more severe visual field loss. Conversely, concentrations of aqueous humor cytokines, particularly PD-L1, were primarily associated with intraocular pressure, and none of the cytokines showed a significant association with visual field damage. This may reflect the characteristics of exosomes, which are advantageous for crossing various biological barriers. Exosomes may contain more information about glaucoma functional damage occurring in the retina or optic nerve head. This highlights the potential importance of exosomes as signaling mediators distinct from other existing molecules.

On-Site Stimulation of Dendritic Cells by Cancer-Derived Extracellular Vesicles on a Core-Shell Nanowire Platform

Extracellular vesicles (EVs) contain a subset of proteins, lipids, and nucleic acids that maintain the characteristics of the parent cell. Immunotherapy using EVs has become a focus of research due to their unique features and bioinspired applications in cancer treatment. Unlike conventional immunotherapy using tumor fragments, EVs can be easily obtained from bodily fluids without invasive actions. We previously fabricated nanowire devices that were specialized for EV collection, but they were not suitable for cell culturing. In this study, we fabricated a ZnO/Al2O3 core-shell nanowire platform that could collect more than 60% of the EVs from the cell supernatant. Additionally, we could continue to culture dendritic cells (DCs) on the platform as an artificial lymph node to investigate cell maturation into antigen-presenting cells. Finally, using this platform, we reproduced a series of on-site immune processes that are among the pivotal immune functions of DCs and include such processes as antigen uptake, antigen presentation, and endocytosis of cancer-derived EVs. This platform provides a new ex vivo tool for EV-DC-mediated immunotherapies.

Meta-analysis study of small extracellular vesicle nursing application therapies for healing of wounds and skin regeneration

We designed and performed this meta-analysis to investigate the impact of the application of extracellular small vesicle therapies on regeneration of skin and wound healing. The findings of this study were computed using fixed or random effect models. The mean differences (MDs), and odds ratio (ORs) with their 95% confidence intervals (CIs) were calculated. In this study, 43 publications were included, encompassing 530 animals with artificial wounds. Small extracellular vesicle therapy had a significant greater rate of wound closure (MD, 24.0; 95% CI, 19.98-28.02, P < 0.001), lower scar width (MD, -191.33; 95%CI, -292.26--90.4, P < 0.001), and higher blood vessel density (MD,36.11; 95%CI, 19.02-53.20, P < 0.001) compared to placebo. Our data revealed that small extracellular vesicle therapy had a significantly higher regeneration of skin and healing of wounds based on the results of wound closure rate, lower scar width, and higher blood vessel density compared to placebo. Future studies with larger sample size are needed.

CD151-enriched migrasomes mediate hepatocellular carcinoma invasion by conditioning cancer cells and promoting angiogenesis

BACKGROUND

The tetraspanin family plays a pivotal role in the genesis of migrasomes, and Tetraspanin CD151 is also implicated in neovascularization within tumorous contexts. Nevertheless, research pertaining to the involvement of CD151 in hepatocellular carcinoma (HCC) neovascularization and its association with migrasomes remains inadequate.

METHODS

To investigate the correlation between CD151 and migrasome marker TSPAN4 in liver cancer, we conducted database analysis using clinical data from HCC patients. Expression levels of CD151 were assessed in HCC tissues and correlated with patient survival outcomes. In vitro experiments were performed using HCC cell lines to evaluate the impact of CD151 expression on migrasome formation and cellular invasiveness. Cell lines with altered CD151 expression levels were utilized to study migrasome generation and in vitro invasion capabilities. Additionally, migrasome function was explored through cellular aggregation assays and phagocytosis studies. Subsequent VEGF level analysis and tissue chip experiments further confirmed the role of CD151 in mediating migrasome involvement in angiogenesis and cellular signal transduction.

RESULTS

Our study revealed a significant correlation between CD151 expression and migrasome marker TSPAN4 in liver cancer, based on database analysis of clinical samples. High expression levels of CD151 were closely associated with poor survival outcomes in HCC patients. Experimentally, decreased CD151 expression led to reduced migrasome generation and diminished in vitro invasion capabilities, resulting in attenuated in vivo metastatic potential. Migrasomes were demonstrated to facilitate cellular aggregation and phagocytosis, thereby promoting cellular invasiveness. Furthermore, VEGF-enriched migrasomes were implicated in signaling and angiogenesis, accelerating HCC progression.

CONCLUSIONS

In summary, our findings support the notion that elevated CD151 expression promotes migrasome formation, and migrasomes play a pivotal role in the invasiveness and angiogenesis of liver cancer cells, thereby facilitating HCC progression. This finding implies that migrasomes generated by elevated CD151 expression may constitute a promising high-priority target for anti-angiogenic therapy in HCC, offering crucial insights for the in-depth exploration of migrasome function and a renewed comprehension of the mechanism underlying liver cancer metastasis.

An anion exchange membrane sensor detects EGFR and its activity state in plasma CD63 extracellular vesicles from patients with glioblastoma

We present a quantitative sandwich immunoassay for CD63 Extracellular Vesicles (EVs) and a constituent surface cargo, EGFR and its activity state, that provides a sensitive, selective, fluorophore-free and rapid alternative to current EV-based diagnostic methods. Our sensing design utilizes a charge-gating strategy, with a hydrophilic anion exchange membrane functionalized with capture antibodies and a charged silica nanoparticle reporter functionalized with detection antibodies. With sensitivity and robustness enhancement by the ion-depletion action of the membrane, this hydrophilic design with charged reporters minimizes interference from dispersed proteins, thus enabling direct plasma analysis without the need for EV isolation or sensor blocking. With a LOD of 30 EVs/μL and a high relative sensitivity of 0.01% for targeted proteomic subfractions, our assay enables accurate quantification of the EV marker, CD63, with colocalized EGFR by an operator/sample insensitive universal normalized calibration. We analysed untreated clinical samples of Glioblastoma to demonstrate this new platform. Notably, we target both total and "active" EGFR on EVs; with a monoclonal antibody mAb806 that recognizes a normally hidden epitope on overexpressed or mutant variant III EGFR. Analysis of samples yielded an area-under-the-curve (AUC) value of 0.99 and a low p-value of 0.000033, surpassing the performance of existing assays and markers.

Biogenesis of extracellular vesicles from the pathogen perspective: Transkingdom strategies for delivering messages

EVs are nanoparticles enclosing proteins, nucleic acids and lipids released by cells and are essential for their metabolism and useful for intercellular communication. The importance of EVs has been highlighted by their use as biomarkers or as vaccine antigens. The release of vesicles is exploited by a wide range of organisms: from unicellular bacteria or protozoa to multicellular prokaryotes like fungi, helminths and arthropods. The mechanisms elucidated to date in each biological group are presented, as well as a discussion of interesting directions for future EV studies.

The tumour-derived extracellular vesicle proteome varies by endometrial cancer histology and is confounded by an obesogenic environment

Endometrial cancer, the most common gynaecological cancer worldwide, is closely linked to obesity and metabolic diseases, particularly in younger women. New circulating biomarkers have the potential to improve diagnosis and treatment selections, which could significantly improve outcomes. Our approach focuses on extracellular vesicle (EV) biomarker discovery by directly profiling the proteome of EVs enriched from frozen biobanked endometrial tumours. We analysed nine tissue samples to compare three clinical subgroups-low BMI (Body Mass Index) Endometrioid, high BMI Endometrioid, and Serous (any BMI)-identifying proteins related to histological subtype, BMI, and shared secreted proteins. Using collagenase digestion and size exclusion chromatography, we successfully enriched generous quantities of EVs (range 204.8-1291.0 µg protein: 1.38 × 1011-1.10 × 1012 particles), characterised by their size (∼150 nm), expression of EV markers (CD63/81), and proposed endometrial cancer markers (L1CAM, ANXA2). Mass spectrometry-based proteomic profiling identified 2075 proteins present in at least one of the 18 samples. Compared to cell lysates, EVs were successfully depleted for mitochondrial and blood proteins and enriched for common EV markers and large secreted proteins. Further analysis highlighted significant differences in EV protein profiles between the high BMI subgroup and others, underlining the impact of comorbidities on the EV secretome. Interestingly, proteins differentially abundant in tissue subgroups were largely not also differential in matched EVs. This research identified secreted proteins known to be involved in endometrial cancer pathophysiology and proposed novel diagnostic biomarkers (EIF6, MUC16, PROM1, SLC26A2).

Dual roles of the conditional extracellular vesicles derived from Pseudomonas aeruginosa biofilms: Promoting and inhibiting bacterial biofilm growth

Antibiotic-resistant biofilm infections have emerged as public health concerns because of their enhanced tolerance to high-dose antibiotic treatments. The biofilm life cycle involves multiple developmental stages, which are tightly regulated by active cell-cell communication via specific extracellular signal messengers such as extracellular vesicles. This study was aimed at exploring the roles of extracellular vesicles secreted by Pseudomonas aeruginosa at different developmental stages in controlling biofilm growth. Our results show that extracellular vesicles secreted by P. aeruginosa biofilms during their exponential growth phase (G-EVs) enhance biofilm growth. In contrast, extracellular vesicles secreted by P. aeruginosa biofilms during their death/survival phase (D-EVs) can effectively inhibit/eliminate P. aeruginosa PAO1 biofilms up to 4.8-log10 CFU/cm2. The inhibition effectiveness of D-EVs against P. aeruginosa biofilms grown for 96 h improved further in the presence of 10-50 μM Fe3+ ions. Proteomic analysis suggests the inhibition involves an iron-dependent ferroptosis mechanism. This study is the first to report the functional role of bacterial extracellular vesicles in bacterial growth, which depends on the developmental stage of the parent bacteria. The finding of D-EV-activated ferroptosis-based bacterial death may have significant implications for preventing antibiotic resistance in biofilms.

Recent research on material-based methods for isolation of extracellular vesicles

Extracellular vesicles (EVs) are nanoparticles secreted by cells with a closed phospholipid bilayer structure, which can participate in various physiological and pathological processes and have significant clinical value in disease diagnosis, targeted therapy and prognosis assessment. EV isolation methods currently include differential ultracentrifugation, ultrafiltration, size exclusion chromatography, immunoaffinity, polymer co-precipitation and microfluidics. In addition, material-based biochemical or biophysical approaches relying on intrinsic properties of the material or its surface-modified functionalized monomers, demonstrated unique advantages in the efficient isolation of EVs. In order to provide new ideas for the subsequent development of material-based EV isolation methods, this review will focus on the principle, research status and application prospects of material-based EV isolation methods based on different material carriers and functional monomers.

SARS-CoV-2 ORF3a drives dynamic dense body formation for optimal viral infectivity

SARS-CoV-2 uses the double-membrane vesicles as replication organelles. However, how virion assembly occurs has not been fully understood. Here we identified a SARS-CoV-2-driven membrane structure named the 3a dense body (3DB). 3DBs have unusual electron-dense and dynamic inner structures, and their formation is driven by the accessory protein ORF3a via hijacking a specific subset of the trans-Golgi network (TGN) and early endosomal membranes. 3DB formation is conserved in related bat and pangolin coronaviruses yet lost during the evolution to SARS-CoV. 3DBs recruit the viral structural proteins spike (S) and membrane (M) and undergo dynamic fusion/fission to facilitate efficient virion assembly. A recombinant SARS-CoV-2 virus with an ORF3a mutant specifically defective in 3DB formation showed dramatically reduced infectivity for both extracellular and cell-associated virions. Our study uncovers the crucial role of 3DB in optimal SARS-CoV-2 infectivity and highlights its potential as a target for COVID-19 prophylactics and therapeutics.

Fusion with ARRDC1 or CD63: A Strategy to Enhance p53 Loading into Extracellular Vesicles for Tumor Suppression

Small extracellular vesicles (sEVs) have emerged as promising therapeutic agents and drug delivery vehicles. Targeted modification of sEVs and their contents using genetic modification strategies is one of the most popular methods. This study investigated the effects of p53 fusion with arrestin domain-containing protein 1 (ARRDC1) and CD63 on the generation of sEVs, p53 loading efficiency, and therapeutic efficacy. Overexpression of either ARRDC1-p53 (ARP) or CD63-p53 (CDP) significantly elevated p53 mRNA and protein levels. The incorporation of ARRDC1 and CD63 significantly enhanced HEK293T-sEV biogenesis, evidenced by significant increases in sEV-associated proteins TSG101 and LAMP1, resulting in a boost in sEV production. Importantly, fusion with ARRDC1 or CD63 substantially increased the efficiency of loading both p53 fusion proteins and its mRNA into sEVs. sEVs equipped with ARP or CDP significantly enhanced the enrichment of p53 fusion proteins and mRNA in p53-null H1299 cells, resulting in a marked increase in apoptosis and a reduction in cell proliferation, with ARP-sEVs demonstrating greater effectiveness than CDP-sEVs. These findings underscore the enhanced functionality of ARRDC1- and CD63-modified sEVs, emphasizing the potential of genetic modifications in sEV-based therapies for targeted cancer treatment.

Pure total flavonoids from Citrus ameliorate NSAIDs-induced intestinal mucosal injury via regulation of exosomal LncRNA H19 and protective autophagy

Introduction

Non-steroid anti-inflammatory drugs (NSAIDs) are a class of prescription drugs with antipyretic, analgesic, anti-inflammatory, and antiplatelet effects. However, long-term use of NSAIDs will disrupt the intestinal mucosal barrier, causing erosion, ulcers, bleeding, and even perforation. Pure total flavonoids from Citrus (PTFC) is extracted from the dried peel of Citrus, showing a protective effect on intestinal mucosal barrier with unclear mechanisms.

Methods

In the present study, we used diclofenac (7.5 mg kg-1, i.g.) to induce a rat model of NSAIDs-related intestinal lesions. PTFC (50, 75, 100 mg·kg-1 d-1, i.g.) was administered 9 days before the initial diclofenac administration, followed by co-administration on the last 5 days. Exosomes were identified by western blotting and transmission electron microscopy (TEM), and then co-cultured with IEC-6 cells. The expression of long non-coding RNA (lncRNA) H19, autophagy-related 5 (Atg5), ZO-1, Occludin, and Claudin-1 were detected by quantitative real-time PCR (qRT-PCR). The expression of light chain 3 (LC3)-I, LC3-II, ZO-1, Occludin and Claudin-1 proteins was tested by western blotting. The localization of both exosomes and autophagosomes was examined by immunofluorescent technique.

Results

The treatment of PTFC attenuated intestinal mucosal mechanical barrier function disturbance in diclofenac-induced NSAIDs rats. IEC-6 cells co-cultured with NSAIDs rats-derived exosomes possessed the lowest levels of protective autophagy, and severe intestinal barrier injuries. Cells co-cultured with the exosomes extracted from rats administrated PTFC exhibited an improvement of autophagy and intestinal mucosal mechanical barrier function. The prevention effect was proportional to the concentration of PTFC administered.

Conclusion

PTFC ameliorated NSAIDs-induced intestinal mucosal injury by down-regulating exosomal lncRNA H19 and promoting autophagy.

Arf GTPase-Activating proteins ADAP1 and ARAP1 regulate incorporation of CD63 in multivesicular bodies

Arf GTPase-activating proteins (ArfGAPs) mediate the hydrolysis of GTP bound to ADP-ribosylation factors. ArfGAPs are critical for cargo sorting in the Golgi-to-ER traffic. However, the role of ArfGAPs in sorting into intralumenal vesicles (ILVs) in multivesicular bodies (MVBs) in post-Golgi traffic remains unclear. Exosomes are extracellular vesicles (EVs) of endosomal origin. CD63 is an EV marker. CD63 is enriched ILVs in MVBs of cells. However, the secretion of CD63 positive EVs has not been consistent with the data on CD63 localization in MVBs, and how CD63-containing EVs are formed is yet to be understood. To elucidate the mechanism of CD63 transport to ILVs, we focused on CD63 localization in MVBs and searched for the ArfGAPs involved in CD63 localization. We observed that ADAP1 and ARAP1 depletion inhibited CD63 localization to enlarged endosomes after Rab5Q79L overexpression. We tested epidermal growth factor (EGF) and CD9 localization in MVBs. We observed that ADAP1 and ARAP1 depletion inhibited CD9 localization in enlarged endosomes but not EGF. Our results indicate ADAP1 and ARAP1, regulate incorporation of CD63 and CD9, but not EGF, in overlapped and different MVBs. Our work will contribute to distinguish heterogenous ILVs and exosomes by ArfGAPs.

Molecular Stratification and Treatment Monitoring of Lung Cancer Using a Small Extracellular Vesicle-Activated Nanocavity Architecture

Development of molecular diagnostics for lung cancer stratification and monitoring is crucial for the rational planning and timely adjustment of treatments to improve clinical outcomes. In this regard, we propose a nanocavity architecture to sensitively profile the protein signature on small extracellular vesicles (sEVs) to enable accurate, noninvasive staging and treatment monitoring of lung cancer. The nanocavity architecture is formed by molecular recognition through the binding of sEVs with the nanobox-based core-shell surface-enhanced Raman scattering (SERS) barcodes and mirrorlike, asymmetric gold microelectrodes. By imposing an alternating current on the gold microelectrodes, a nanofluidic shear force was stimulated that supported the binding of sEVs and the efficient assembly of the nanoboxes. The binding of sEVs further induced a nanocavity between the nanobox and the gold microelectrode that significantly amplified the electromagnetic field to enable the simultaneous enhancement of Raman signals from four SERS barcodes and generate patient-specific molecular sEV signatures. Importantly, evaluated on a cohort of clinical samples (n = 76) on the nanocavity architecture, the acquired patient-specific sEV molecular signatures achieved accurate identification, stratification, and treatment monitoring of lung cancer patients, highlighting its potential for transition to clinical utility.

LS, Saftics A, Shodubi O, Raghunandan S, Xu J, Tsai SJ, Dong Y, Li R, Jovanovic-Talisman T, Gould SJ. Endocytosis blocks the vesicular secretion of exosome marker proteins

Exosomes are secreted vesicles of ~30 to 150 nm diameter that play important roles in human health and disease. To better understand how cells release these vesicles, we examined the biogenesis of the most highly enriched human exosome marker proteins, the exosomal tetraspanins CD81, CD9, and CD63. We show here that endocytosis inhibits their vesicular secretion and, in the case of CD9 and CD81, triggers their destruction. Furthermore, we show that syntenin, a previously described exosome biogenesis factor, drives the vesicular secretion of CD63 by blocking CD63 endocytosis and that other endocytosis inhibitors also induce the plasma membrane accumulation and vesicular secretion of CD63. Finally, we show that CD63 is an expression-dependent inhibitor of endocytosis that triggers the vesicular secretion of lysosomal proteins and the clathrin adaptor AP-2 mu2. These results suggest that the vesicular secretion of exosome marker proteins in exosome-sized vesicles occurs primarily by an endocytosis-independent pathway.

Bifunctional iRGD-Exo-DOX crosses the blood-brain barrier to target central nervous system lymphoma

Central nervous system lymphoma (CNSL) is a type of hematological tumor. Treatment of CNSL is difficult due to the existence of the blood-brain barrier (BBB). Here, we used exosomes (Exos), a type of extracellular vesicle, and iRGD to construct a new drug carrier system and use it to load doxorubicin (DOX). The results of in vitro and in vivo experiments showed that the iRGD-Exo-DOX system can efficiently and securely transport DOX through the BBB and target tumor cells. The results suggest that iRGD-Exo-DOX may cross the BBB through brain microvascular endothelial cell-mediated endocytosis. Together, our study indicates an impactful treatment of central nervous system tumors.

Treating cancer through modulating exosomal protein loading and function: The prospects of natural products and traditional Chinese medicine

Exosomes, small yet vital extracellular vesicles, play an integral role in intercellular communication. They transport critical components, such as proteins, lipid bilayers, DNA, RNA, and glycans, to target cells. These vesicles are crucial in modulating the extracellular matrix and orchestrating signal transduction processes. In oncology, exosomes are pivotal in tumor growth, metastasis, drug resistance, and immune modulation within the tumor microenvironment. Exosomal proteins, noted for their stability and specificity, have garnered widespread attention. This review delves into the mechanisms of exosomal protein loading and their impact on tumor development, with a focus on the regulatory effects of natural products and traditional Chinese medicine on exosomal protein loading and function. These insights not only offer new strategies and methodologies for cancer treatment but also provide scientific bases and directions for future clinical applications.

Extracellular vesicles isolated from Arabidopsis thaliana leaves reveal characteristics of mammalian exosomes

Plant-derived extracellular vesicles (EVs), containing a myriad of bioactive proteins, microRNAs, lipids, and secondary metabolites, have recently become the focus of rising interest due to their important roles in various applications. The widely accepted method for isolating plant EVs is differential ultracentrifugation plus density gradient centrifugation. However, the combination of differential ultracentrifugation and density gradient centrifugation for the isolation of plant EVs is time-consuming and labor-intensive. Hence, there is a need for more efficient methods to perform the separation of plant EVs. In this study, EVs were separated from Arabidopsis thaliana leaves by a cost-effective polyethylene glycol (PEG)-based precipitation approach. The mean size of purified Arabidopsis thaliana EVs determined by dynamic light scattering was 266 nm, which is consistent with nanoparticle tracking analysis. The size was also confirmed via transmission electron microscopy with morphology of a cup-shaped appearance which is the typical mammalian exosome's morphology. Additionally, Western blotting of the purified Arabidopsis thaliana EVs, using commercially available mammalian exosomal kits, displayed surface marker tetraspanin proteins (CD9, CD63, and CD81), and endosomal sorting complexes required for transport (ESCRT)-associated proteins (TSG101 and ALIX). This demonstrates that the purified Arabidopsis thaliana EVs reveal the typical proteins reported in mammalian exosomes.

Cellulose Nanofibrils of High Immunoaffinity for Efficient Enrichment of Small Extracellular Vesicles

Extracellular vesicles (EVs), crucial in facilitating the transport of diverse molecular cargoes for intercellular communication, have shown great potential in diagnostics, therapeutics, and drug delivery. The challenge of developing effective preparation methods for EVs is heightened by their intrinsic heterogeneity and complexity. Here, a novel strategy for high EV enrichment is developed by utilizing EV-affinitive-modified cellulose nanofibrils. Specifically, modified cellulose with rich carboxyl groups has outstanding dispersing properties, able to be dispersed into cellulose nanofibrils in solution. These cellulose nanofibrils are utilized as scaffolds for the immobilization of EV-affinitive antibody of CD63 by chemical conjugation. The CD63-modified nanofibrils demonstrate a superior EV capture efficiency of 86.4% compared with other reported methods. The high performance of this system is further validated by the efficient capture of EVs from biological blood plasma, allowing the detection of bioactive markers from EV-derived miRNAs and proteins. The authors envision that these modified cellulose nanofibrils of enhanced capability on EV enrichment will open new avenues in various biomedical applications.

Charge-Based Isolation of Extracellular Vesicles from Human Plasma

Extracellular vesicles (EVs) have garnered significant attention due to their potential applications in disease diagnostics and management. However, the process of isolating EVs, primarily from blood samples, is still suboptimal. This is mainly attributed to the abundant nature of soluble proteins and lipoproteins, which are often separated together with EVs in the end products of conventional isolation methods. As such, we devise a single-step charge-based EV isolation method by utilizing positively charged beads to selectively remove negatively charged major impurities from human plasma via electrostatic interaction. By carefully controlling the buffer pH, we successfully collected EVs from undesired plasma components with superior purity and yield compared to conventional EV collection methods. Moreover, the developed process is rapid, taking only about 20 min for overall EV isolation. The charge-based isolation can ultimately benefit the EV-based liquid biopsy field for the early diagnosis of various diseases.

Unveiling the Potential of Extracellular Vesicles as Biomarkers and Therapeutic Nanotools for Gastrointestinal Diseases

Extracellular vesicles (EVs), acting as inherent nanocarriers adept at transporting a range of different biological molecules such as proteins, lipids, and genetic material, exhibit diverse functions within the gastroenteric tract. In states of normal health, they participate in the upkeep of systemic and organ homeostasis. Conversely, in pathological conditions, they significantly contribute to the pathogenesis of gastrointestinal diseases (GIDs). Isolating EVs from patients' biofluids facilitates the discovery of new biomarkers that have the potential to offer a rapid, cost-effective, and non-invasive method for diagnosing and prognosing specific GIDs. Furthermore, EVs demonstrate considerable therapeutic potential as naturally targeted physiological carriers for the intercellular delivery of therapeutic cargo molecules or as nanoscale tools engineered specifically to regulate physio-pathological conditions or disease progression. Their attributes including safety, high permeability, stability, biocompatibility, low immunogenicity, and homing/tropism capabilities contribute to their promising clinical therapeutic applications. This review will delve into various examples of EVs serving as biomarkers or nanocarriers for therapeutic cargo in the context of GIDs, highlighting their clinical potential for both functional and structural gastrointestinal conditions. The versatile and advantageous properties of EVs position them as promising candidates for innovative therapeutic strategies in advancing personalized medicine approaches tailored to the gastroenteric tract, addressing both functional and structural GIDs.

Exosomes biogenesis was increased in metformin-treated human ovary cancer cells; possibly to mediate resistance

BACKGROUND

Exosomes derived from tumor cells contribute to the pathogenesis of cancers. Metformin, the most usually used drug for type 2 diabetes, has been frequently investigated for anticancer effects. Here, we examined whether metformin affects exosomes signaling in human ovary cancer cells in vitro.

METHODS

Human ovary cancer cells, including A2780 and Skov3 cells, were treated with metformin for either 24-48 h. Cell viability and caspase-3 activity were determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and colorimetric assays respectively. Oil-Red-O staining and in vitro, scratch assays were used to examine cellular toxicity and wound healing rate. After treatment with metformin, exosomes were isolated from cells and quantified by acetylcholinesterase (AChE) assay, Dynamic Light Scattering (DLS), and their markers. Genes related to exosomes signaling were analyzed by real-time PCR or western blotting.

RESULTS

Our results showed that metformin decreased the viability of both cells dose/time-dependently (P < 0.05). Metformin increased the activity of caspase-3 (P < 0.05) as well as the number of Oil-Red-O positive cells in both cell lines. In vitro scratch assay showed that the cell migration rate of metformin-treated cells was decreased (P < 0.05), whereas AChE activity of exosomes from metformin-treated cells was increased (P < 0.05). Concurrent with an increase in CD63 protein levels, expression of Alix, CD63, CD81, Lamp-2, and Rab27b up-regulated in treated cells (P < 0.05).

CONCLUSION

Results indicated that metformin had a cytotoxic effect on ovary cancer cells and enhanced exosome biogenesis and secretion.

Multiparametric Single-Vesicle Flow Cytometry Resolves Extracellular Vesicle Heterogeneity and Reveals Selective Regulation of Biogenesis and Cargo Distribution

Mammalian cells release a heterogeneous array of extracellular vesicles (EVs) that contribute to intercellular communication by means of the cargo that they carry. To resolve EV heterogeneity and determine if cargo is partitioned into select EV populations, we developed a method named "EV Fingerprinting" that discerns distinct vesicle populations using dimensional reduction of multiparametric data collected by quantitative single-EV flow cytometry. EV populations were found to be discernible by a combination of membrane order and EV size, both of which were obtained through multiparametric analysis of fluorescent features from the lipophilic dye Di-8-ANEPPS incorporated into the lipid bilayer. Molecular perturbation of EV secretion and biogenesis through respective ablation of the small GTPase Rab27a and overexpression of the EV-associated tetraspanin CD63 revealed distinct and selective alterations in EV populations, as well as cargo distribution. While Rab27a disproportionately affects all small EV populations with high membrane order, the overexpression of CD63 selectively increased the production of one small EV population of intermediate membrane order. Multiplexing experiments subsequently revealed that EV cargos have a distinct, nonrandom distribution with CD63 and CD81 selectively partitioning into smaller vs larger EVs, respectively. These studies not only present a method to probe EV biogenesis but also reveal how the selective partitioning of cargo contributes to EV heterogeneity.

NOX2 and NOX4 expression in monocytes and macrophages-extracellular vesicles in signalling and therapeutics

Extracellular vesicles (EVs) are a type of cytoplasmic vesicles secreted by a variety of cells. EVs originating from cells have been known to participate in cell communication, antigen presentation, immune cell activation, tolerance induction, etc. These EVs can also carry the active form of Nicotinamide Adenine Dinucleotide Phosphate Oxidase Hydrogen (NADPH) oxidase, which is very essential for the production of reactive oxygen species (ROS) and that can then modulate processes such as cell regeneration. The aim of this study is to characterize the EVs isolated from U-937 and THP-1 cells, identify the NADPH oxidase (NOX) isoforms, and to determine whether EVs can modulate NOX4 and NOX2 in monocytes and macrophages. In our study, isolated EVs of U-937 were characterized using dynamic light scattering (DLS) spectroscopy and immunoblotting. The results showed that the exogenous addition of differentiation agents (either phorbol 12-myristate 13-acetate (PMA) or ascorbic acid) or the supplementation of EVs used in the study did not cause any stress leading to alterations in cell proliferation and viability. In cells co-cultured with EVs for 72 h, strong suppression of NOX4 and NOX2 is evident when monocytes transform into macrophagic cells. We also observed lower levels of oxidative stress measured using immunoblotting and electron paramagnetic resonance spectroscopy under the EVs co-cultured condition, which also indicates that EVs might contribute significantly by acting as an antioxidant source, which agrees with previous studies that hypothesized the role of EVs in therapeutics. Therefore, our results provide evidence for NOX regulation by EVs in addition to its role as an antioxidant cargo.

Clinical significance of small extracellular vesicles in cholangiocarcinoma

Cholangiocarcinoma is an aggressive and heterogeneous malignancy originating from the bile duct epithelium. It is associated with poor prognosis and high mortality. The global incidence of cholangiocarcinoma is rising, and there is an urgent need for effective early diagnosis and treatment strategies to reduce the burden of this devastating tumor. Small extracellular vesicles, including exosomes and microparticles, are nanoscale vesicles formed by membranes that are released both normally and pathologically from cells, mediating the intercellular transfer of substances and information. Recent studies have demonstrated the involvement of small extracellular vesicles in numerous biological processes, as well as the proliferation, invasion, and metastasis of tumor cells. The present review summarizes the tumorigenic roles of small extracellular vesicles in the cholangiocarcinoma microenvironment. Owing to their unique composition, accessibility, and stability in biological fluids, small extracellular vesicles have emerged as ideal biomarkers for use in liquid biopsies for diagnosing and outcome prediction of cholangiocarcinoma. Specific tissue tropism, theoretical biocompatibility, low clearance, and strong biological barrier penetration of small extracellular vesicles make them suitable drug carriers for cancer therapy. Furthermore, the potential value of small extracellular vesicle-based therapies for cholangiocarcinoma is also reviewed.

Extracellular Vesicles as Surrogates for the Regulation of the Drug Transporters ABCC2 (MRP2) and ABCG2 (BCRP)

Drug efflux transporters of the ATP-binding-cassette superfamily play a major role in the availability and concentration of drugs at their site of action. ABCC2 (MRP2) and ABCG2 (BCRP) are among the most important drug transporters that determine the pharmacokinetics of many drugs and whose overexpression is associated with cancer chemoresistance. ABCC2 and ABCG2 expression is frequently altered during treatment, thus influencing efficacy and toxicity. Currently, there are no routine approaches available to closely monitor transporter expression. Here, we developed and validated a UPLC-MS/MS method to quantify ABCC2 and ABCG2 in extracellular vesicles (EVs) from cell culture and plasma. In this way, an association between ABCC2 protein levels and transporter activity in HepG2 cells treated with rifampicin and hypericin and their derived EVs was observed. Although ABCG2 was detected in MCF7 cell-derived EVs, the transporter levels in the vesicles did not reflect the expression in the cells. An analysis of plasma EVs from healthy volunteers confirmed, for the first time at the protein level, the presence of both transporters in more than half of the samples. Our findings support the potential of analyzing ABC transporters, and especially ABCC2, in EVs to estimate the transporter expression in HepG2 cells.

Milk Extracellular Vesicles: Natural Nanoparticles for Enhancing Oral Drug Delivery against Bacterial Infections

Oral drug delivery is typically preferred as a therapeutic intervention due to the complexities and expenses associated with intravenous administration. However, some drugs are poorly absorbed orally, requiring intravenous administration to bypass the gastrointestinal tract and deliver the drug directly into the bloodstream. Thus, there is an urgent need to develop novel drug delivery platforms to overcome the challenges of oral drug delivery with low solubility, low permeability, oral degradation, and low bioavailability. Advances in extracellular vesicles (EVs) as natural carriers have provided emerging approaches to improve potential therapeutic applications. Milk not only contains traditional nutrients but is also rich in EVs. In this Review, we focus mainly on the purification of milk EVs (mEVs), their safety, and the advantages of mEV-based drug carriers in combatting intestinal infections. Additionally, we summarize several advantages of mEVs over conventional synthetic carriers, such as low immunogenicity, high biocompatibility, and the ability to transfer bioactive molecules between cells. Considering the unmet gaps of mEVs in clinical translation, it is essential to review the cargo loading into mEVs and future perspectives for their use as natural drug carriers for oral delivery. This overview of mEV-based drug carriers for oral delivery sheds light on alternative approaches to treat clinical infections associated with intestinal pathogens and the development of novel oral delivery systems.

A Smart DNA Hydrogel Enables Synergistic Immunotherapy and Photodynamic Therapy of Melanoma

Immunotherapy faces insufficient immune activation and limited immune effectiveness. Herein, we report a smart DNA hydrogel that enables the release of multivalent functional units at the tumor site to enhance the efficacy of immunotherapy. The smart DNA hydrogel was assembled from two types of ultra-long DNA chains synthesized via rolling circle amplification. One DNA chain contained immune adjuvant CpG oligonucleotides and polyaptamers for loading natural killer cell-derived exosomes; the other chain contained multivalent G-quadruplex for loading photodynamic agents. DNA chains formed DNA hydrogel through base-pairing. HhaI restriction endonuclease sites were designed between functional units. Upon stimuli in the tumor sites, the hydrogel was effectively cleaved by the released HhaI and disassembled into functional units. Natural killer cell-derived exosomes played an anti-tumor role, and the CpG oligonucleotide activated antigen-presenting cells to enhance the immunotherapy. Besides the tumor-killing effect of photodynamic therapy, the generated cellular debris acted as an immune antigen to further enhance the immunotherapeutic effect. In a mouse melanoma orthotopic model, the smart DNA hydrogel as a localized therapeutic agent, achieved a remarkable tumor suppression rate of 91.2 %. The smart DNA hydrogel exhibited enhanced efficacy of synergistic immunotherapy and photodynamic therapy, expanding the application of DNA materials in biomedicine.

Schwann cell-derived exosomes promote lung cancer progression via miRNA-21-5p

Schwann cells (SCs), the primary glial cells of the peripheral nervous system, which have been identified in many solid tumors, play an important role in cancer development and progression by shaping the tumor immunoenvironment and supporting the development of metastases. Using different cellular, molecular, and genetic approaches with integrated bioinformatics analysis and functional assays, we revealed the role of human SC-derived exosomal miRNAs in lung cancer progression in vitro and in vivo. We found that exosomal miRNA-21 from SCs up-regulated the proliferation, motility, and invasiveness of human lung cancer cells in vitro, which requires functional Rab small GTPases Rab27A and Rab27B in SCs for exosome release. We also revealed that SC exosomal miRNA-21-5p regulated the functional activation of tumor cells by targeting metalloprotease inhibitor RECK in tumor cells. Integrated bioinformatic analyses showed that hsa-miRNA-21-5p is associated with poor prognosis in patients with lung adenocarcinoma and can promote lung cancer progression through multiple signaling pathways including the MAPK, PI3K/Akt, and TNF signaling. Furthermore, in mouse xenograft models, SC exosomes and SC exosomal hsa-miRNA-21-5p augmented human lung cancer cell growth and lymph node metastasis in vivo. Together our data revealed, for the first time, that SC-secreted exosomes and exosomal miRNA-21-5p promoted the proliferation, motility, and spreading of human lung cancer cells in vitro and in vivo. Thus, exosomal miRNA-21 may play an oncogenic role in SC-accelerated progression of lung cancer and this pathway may serve as a new therapeutic target for further evaluation.

Exosomes and exosomal miRNAs: A new avenue for the future treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic systemic autoimmune disease that involves mainly synovitis and joint injury and is one of the main causes of disability. The pathogenesis of rheumatoid arthritis is complicated, and the treatment cycle is long. The traditional methods of inhibiting inflammation and immunosuppression are no longer sufficient for treatment of the disease, so there is an urgent need to seek new treatments. The exocrine microenvironment is a kind of microvesicle with a lipid bilayer membrane structure that can be secreted by most cells in the body. This structure contains cell-specific proteins, lipids and nucleic acids that can transmit this information from one cell to another. To achieve cell-to-cell communication. Exocrine microRNAs can be contained in exocrine cells and can be selectively transferred to target receptor cells via exocrine signaling, thus regulating the physiological function of target cells. This article focuses on the pathological changes that occur during the development of rheumatoid arthritis and the biological regulation of exocrine and exocrine microRNAs in rheumatoid joints. Research on the roles of exocrine and exocrine microRNAs in regulating the inflammatory response, cell proliferation/apoptosis, autophagy, effects on fibroblast-like synoviocytes and immune regulation in rheumatoid arthritis was reviewed. In addition, the challenges faced by this new treatment are discussed.

Matrimeres are systemic nanoscale mediators of tissue integrity and function

Tissue barriers must be rapidly restored after injury to promote regeneration. However, the mechanism behind this process is unclear, particularly in cases where the underlying extracellular matrix is still compromised. Here, we report the discovery of matrimeres as constitutive nanoscale mediators of tissue integrity and function. We define matrimeres as non-vesicular nanoparticles secreted by cells, distinguished by a primary composition comprising at least one matrix protein and DNA molecules serving as scaffolds. Mesenchymal stromal cells assemble matrimeres from fibronectin and DNA within acidic intracellular compartments. Drawing inspiration from this biological process, we have achieved the successful reconstitution of matrimeres without cells. This was accomplished by using purified matrix proteins, including fibronectin and vitronectin, and DNA molecules under optimal acidic pH conditions, guided by the heparin-binding domain and phosphate backbone, respectively. Plasma fibronectin matrimeres circulate in the blood at homeostasis but exhibit a 10-fold decrease during systemic inflammatory injury in vivo . Exogenous matrimeres rapidly restore vascular integrity by actively reannealing endothelial cells post-injury and remain persistent in the host tissue matrix. The scalable production of matrimeres holds promise as a biologically inspired platform for regenerative nanomedicine.

Effect of Sample Preprocessing and Size-Based Extraction Methods on the Physical and Molecular Profiles of Extracellular Vesicles

Extracellular vesicles (EVs) are nanometric lipid vesicles that shuttle cargo between cells. Their analysis could shed light on health and disease conditions, but EVs must first be preserved, extracted, and often preconcentrated. Here we first compare plasma preservation agents, and second, using both plasma and cell supernatant, four EV extraction methods, including (i) ultracentrifugation (UC), (ii) size-exclusion chromatography (SEC), (iii) centrifugal filtration (LoDF), and (iv) accousto-sorting (AcS). We benchmarked them by characterizing the integrity, size distribution, concentration, purity, and expression profiles for nine proteins of EVs, as well as the overall throughput, time-to-result, and cost. We found that the difference between ethylenediaminetetraacetic acid (EDTA) and citrate anticoagulants varies with the extraction method. In our hands, ultracentrifugation produced a high yield of EVs with low contamination; SEC is low-cost, fast, and easy to implement, but the purity of EVs is lower; LoDF and AcS are both compatible with process automation, small volume requirement, and rapid processing times. When using plasma, LoDF was susceptible to clogging and sample contamination, while AcS featured high purity but a lower yield of extraction. Analysis of protein profiles suggests that the extraction methods extract different subpopulations of EVs. Our study highlights the strengths and weaknesses of sample preprocessing methods, and the variability in concentration, purity, and EV expression profiles of the extracted EVs. Preanalytical parameters such as collection or preprocessing protocols must be considered as part of the entire process in order to address EV diversity and their use as clinically actionable indicators.

Exosome Heterogeneity Affects the Distal "Barrier-Crossing" Trafficking of Exosome Encapsulated Quantum Dots

The biological activities of nanoparticles (NPs), which include endocytosis by macrophages and subsequent intracellular degradation and/or release, transfer to other cells, or translocation across tissue barriers, highly depend on their fate in living organisms. Yet, translocation across barriers, especially the distal "barrier-crossing" trafficking of NPs, is still unclear. The exosome (Exo) plays a crucial role in intercellular communication and biological barrier trafficking. Here, we report that ZnCdSe@ZnS quantum dots (QDs), as a representation of NPs in biomedical applications, could cross the blood-brain barrier and approach the mouse brain via active Exo encapsulation. By employing multiple techniques, we demonstrated that QDs were internalized by macrophages (J774A.1) and tumor cells (HeLa) and then released to the extracellular environment along with Exo. Exo encapsulation facilitates the distal barrier-crossing trafficking of QDs in vivo, while Exo biogenesis inhibitor GW4869 suppressed the QDs enriched in the brains of mice with a 4T1-Luc breast cancer xenograft. Interestingly, Exo heterogeneity affects the distal trafficking of enveloped QDs. Exo derived from tumorous HeLa cells, not macrophages, that were enriched in functional proteins with cell adhesion, cell migration, axon guidance, and cell motility, showed a better capacity for the remote trafficking of QDs. This study proposes Exo as a vehicle to deliver exogenous NPs to translocate across the distal barrier and provides further information for biomedical application and the risk assessment of NPs.

Identification of the exosomal PD-L1 inhibitor to promote the PD-1 targeting therapy of gastric cancer

Programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) targeting therapy is widely applied in clinics for gastric cancer treatment. Nevertheless, the clinical response is not well acceptable due to the exosomal PD-L1. Hence, abrogation of the exosomal PD-L1 may be a strategy to sensitize the gastric cancer cell to PD-1 targeting therapy. With the aid of CD63 targeting antibody and PD-L1 targeting aptamer, HTRF based assay was established to quantify the exosomal PD-L1, and applied to our in-house compound library, resulting in the identification of moclobemide. Further optimization of moclobemide lead to EP16, which can inhibit the generation of exosomal PD-L1 with IC50 = 0.108 μM. By applying EP16 to gastric cancer cell line coupled with T-cell activity related experiment, it was validated to activate T-cell and can promote the response of PD-1 targeting therapy for gastric cancer treatment in vitro and in vivo. Collectively, our findings give a promising tool to promote the sensitivity of anti-PD-1 for gastric cancer treatment, and EP16 can serve as a leading compound for exosomal PD-L1 abrogation.

NSP6 inhibits the production of ACE2-containing exosomes to promote SARS-CoV-2 infectivity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered a global pandemic, which severely endangers public health. Our and others' works have shown that the angiotensin-converting enzyme 2 (ACE2)-containing exosomes (ACE2-exos) have superior antiviral efficacies, especially in response to emerging variants. However, the mechanisms of how the virus counteracts the host and regulates ACE2-exos remain unclear. Here, we identified that SARS-CoV-2 nonstructural protein 6 (NSP6) inhibits the production of ACE2-exos by affecting the protein level of ACE2 as well as tetraspanin-CD63 which is a key factor for exosome biogenesis. We further found that the protein stability of CD63 and ACE2 is maintained by the deubiquitination of proteasome 26S subunit, non-ATPase 12 (PSMD12). NSP6 interacts with PSMD12 and counteracts its function, consequently promoting the degradation of CD63 and ACE2. As a result, NSP6 diminishes the antiviral efficacy of ACE2-exos and facilitates the virus to infect healthy bystander cells. Overall, our study provides a valuable target for the discovery of promising drugs for the treatment of coronavirus disease 2019.

IMPORTANCE

The outbreak of coronavirus disease 2019 (COVID-19) severely endangers global public health. The efficacy of vaccines and antibodies declined with the rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutants. Angiotensin-converting enzyme 2-containing exosomes (ACE2-exos) therapy exhibits a broad neutralizing activity, which could be used against various viral mutations. Our study here revealed that SARS-CoV-2 nonstructural protein 6 inhibited the production of ACE2-exos, thereby promoting viral infection to the adjacent bystander cells. The identification of a new target for blocking SARS-CoV-2 depends on fully understanding the virus-host interaction networks. Our study sheds light on the mechanism by which the virus resists the host exosome defenses, which would facilitate the study and design of ACE2-exos-based therapeutics for COVID-19.