sEV miRNAs Research Articles

Characterization of plasma-derived small extracellular vesicle miRNA and protein cargo in hereditary angioedema

Hereditary angioedema (HAE) is an inherited disorder causing attacks of subcutaneous tissue or mucosa swelling. The disease burden and attack frequencies vary significantly among patients. This is the first pilot study investigating small extracellular vesicles (sEV) as potential disease modulators in HAE.Plasma-derived sEVs from HAE patients and healthy donors (HD) were thoroughly characterized by Western blot, transmission electron microscopy, nanoparticle tracking and bead-based flow cytometry. The miRNA content of sEVs was examined by nCounter technology and used to predict sEV-based pathomechanisms in silico. All sEV readouts were analyzed regarding HAE-related changes and associations with clinical parameters and attack frequency.Total sEV protein levels were elevated in HAE patients compared to HD. In HAE patients, lower levels of sEVs carrying CD8, CD209, CD81, CD24 and CD44 were measured. sEV miRNA profiling revealed 84 HAE-exclusive and 30 significantly HAE-upregulated candidates. Core hubs of their predicted interaction networks were AGO2, VEGF, RGS5, MTA1, IFG1 and BAX. A set of 12 and 36 sEV miRNAs were restricted to patients with absent attacks or patients with present attacks during prophylactic therapy, respectively.sEVs, especially sEV miRNAs, could contribute to disease pathogenesis and differential attack frequencies. They emerged as disease modulators in HAE and require further study to reveal underlying mechanisms.

In Situ, Fusion-Free, Multiplexed Detection of Small Extracellular Vesicle miRNAs for Cancer Diagnostics.

Tumor-derived small extracellular vesicle (sEV) microRNAs (miRNAs) are emerging biomarkers for cancer diagnostics. Conventional sEV miRNA detection methods necessitate the lysis of sEVs, rendering them laborious and time-consuming and potentially leading to damage or loss of miRNAs. Membrane fusion-based in situ detection of sEV miRNAs involves the preparation of probe-loaded vesicles (e.g., liposomes or cellular vesicles), which are typically sophisticated and require specialist equipment. Membrane perforation methods employ chemical treatments that can induce severe miRNA degradation or leaks. Inspired by previous studies that loaded nucleic acids into EVs or cells using hydrophobic tethers for therapeutic applications, herein, we repurposed this strategy by conjugating a hydrophobic tether onto molecular beacons to aid their transportation into sEVs, allowing for in situ detection of miRNAs in a fusion-free and multiplexing manner. This method enables simultaneous detection of multiple miRNA species within serum-derived sEVs for the diagnosis of prostate cancer, breast cancer, and gastric cancer with an accuracy of 83.3%, 81.8%, and 100%, respectively, in a cohort of 66 individuals, indicating that it holds a high application potential in clinical diagnostics.

Non-canonical RNA-binding protein ANXA11 regulates microRNA resorting into small extracellular vesicles to mediate cisplatin resistance.

The sensitivity of laryngeal squamous cell carcinoma (LSCC) to chemotherapy shows large heterogeneity. The role of miRNA in small extracellular vesicles (sEV) in chemotherapy resistance is under investigation. However, the regulation and sorting mechanism of sEV miRNAs remains unclear. In this study, small RNA sequencing was used to explore miRNA expression profiles in sEV of LSCC after cisplatin stimulation; RNA pull-down, mass spectrometry, and EMSA were used to clarify the binding of candidate RNA-binding protein (RBP) and candidate miRNA. Immunostaining and microRNA fluorescence insitu hybridization were performed to identify how candidate RBP affects miRNA stability and nuclear/cytoplasmic distribution. Invivo experiments were performed to verify the biological functions and response to cisplatin of candidate RBP. We found that cisplatin stimulation induced increased expression of miR-148a-3p and sEV sorting. ANXA11 binds to miR-148a-3p in a sequence-specific manner. ANXA11 inhibits tumor cell proliferation and drug resistance by binding to and retaining miR-148a-3p. Cisplatin stimulation reduced ANXA11 expression and promoted miR-148a-3p efflux through sEV pathways. ANXA11 overexpression reduced invivo tumor proliferation and cisplatin-resistance. Taken together, ANXA11 mediates cisplatin resistance through sEV miRNA resorting. Mechanically, ANXA11 binds to miR-148a-3p in a sequence-specific manner to regulate its resorting and thus influences tumor proliferation and chemoresistance.

Tumor-associated genetic amplifications impact extracellular vesicle miRNA cargo and their recruitment of nerves in head and neck cancer.

Cancer neuroscience is an emerging field of cancer biology focused on defining the interactions and relationships between the nervous system, developing malignancies, and their environments. Our previous work demonstrates that small extracellular vesicles (sEVs) released by head and neck squamous cell carcinomas (HNSCCs) recruit loco-regional nerves to the tumor. sEVs contain a diverse collection of biological cargo, including microRNAs (miRNAs). Here, we asked whether two genes commonly amplified in HNSCC, CCND1, and PIK3CA, impact the sEV miRNA cargo and, subsequently, sEV-mediated tumor innervation. To test this, we individually overexpressed these genes in a syngeneic murine HNSCC cell line, purified their sEVs, and tested their neurite outgrowth activity on dorsal root ganglia (DRG) neurons invitro. sEVs purified from Ccnd1-overexpressing cells significantly increased neurite outgrowth of DRG compared to sEVs from parental or Pik3ca over-expressing cells. When implanted into C57BL/6 mice, Ccnd1 over-expressing tumor cells promoted significantly more tumor innervation invivo. qPCR analysis of sEVs shows that increased expression of Ccnd1 altered the packaging of miRNAs (miR-15-5p, miR-17-5p, and miR-21-5p), many of which target transcripts important in regulating axonogenesis. These data indicate that genetic amplifications harbored by malignancies impose changes in sEV miRNA cargo, which can influence tumorc innervation.

Extracellular vesicle miRNAs for predicting the efficacy of late-line treatment with anlotinib in patients with lung adenocarcinoma

BackgroundAnlotinib is a targeted therapy indicated for some malignancies, including advanced non-small cell lung cancer (NSCLC). However, noninvasive biomarkers for identifying patients who will benefit from this disease remain lacking.MethodsHere, we investigated the potential of small extracellular vesicle (sEV) microRNAs (miRNAs) as predictive biomarkers for anlotinib efficacy. A total of 20 advanced NSCLC patients were enrolled. Patients were classified as having stable disease (SD) or progressive disease (PD) after the initial efficacy assessment.ResultsSeven differentially expressed miRNAs (DEMs) were identified. Among them, miR-941 was significantly upregulated in the PD group, while the others were downregulated. Furthermore, these six downregulated miRNAs (miR-30a-3p, miR-150-5p, miR-122-5p, miR-10b-5p, miR-92a-3p, and miR-150-3p) were more pronounced in nonsmoking patients.ConclusionsIt was found that sEV miRNAs have the potential to predict the benefit of anlotinib.

Identifying MiR-140-3p as a stable internal reference to normalize MicroRNA qRT-PCR levels of plasma small extracellular vesicles in lung cancer patients

Exploration of a stably expressed gene as a reference is critical for the accurate evaluation of miRNAs isolated from small extracellular vesicles (sEVs). In this study, we analyzed small RNA sequencing on plasma sEV miRNAs in the training dataset (n = 104) and found that miR-140-3p was the most stably expressed candidate reference for sEV miRNAs. We further demonstrated that miR-140-3p expressed most stably in the validation cohort (n = 46) when compared to two other reference miRNAs, miR-451a and miR-1228-3p, and the commonly-used miRNA reference U6. Finally, we compared the capability of miR-140-3p and U6 as the internal reference for sEV miRNA expression by evaluating key miRNAs expression in lung cancer patients and found that miR-140-3p was more suitable as a sEV miRNA reference gene. Taken together, our data indicated miR-140-3p as a stable internal reference miRNA of plasma sEVs to evaluate miRNA expression profiles in lung cancer patients.

A Group of Highly Secretory miRNAs Correlates with Lymph Node Metastasis and Poor Prognosis in Oral Squamous Cell Carcinoma.

MicroRNAs (miRNAs) in oral squamous cell carcinoma (OSCC)-derived small extracellular vesicles (sEVs) play a pivotal role in modulating intercellular communications between tumor cells and other cells in the microenvironment, thereby influencing tumor progression and the efficacy of therapeutic interventions. However, a comprehensive inventory of these secretory miRNAs in sEVs and their biological and clinical implications remains elusive. This study aims to profile the miRNA content of OSCC cell line sEVs and computationally elucidate their biological and clinical relevance. We conducted miRNA sequencing to compare the miRNA profiles of OSCC cells and their corresponding sEVs. Our motif enrichment analysis identified specific sorting motifs that are implicated in either cellular retention or preferential sEV secretion. Target cell analysis suggested that the sEV miRNAs potentially interact with various immune cell types, including natural killer cells and dendritic cells. Additionally, we explored the clinical relevance of these miRNAs by correlating their expression levels with TNM stages and patient survival outcomes. Intriguingly, our findings revealed that a distinct sEV miRNA signature is associated with lymph node metastasis and poorer survival in patients in TCGA-HNSC dataset. Collectively, this research furthers our understanding of the miRNA sorting mechanisms in OSCC and underscores their clinical implications.

Diagnostic plasma small extracellular vesicles miRNA signatures for pancreatic cancer using machine learning methods

BackgroundIdentifying biomarkers may lead to easier detection and a better understanding of pathogenesis of pancreatic ductal adenocarcinoma (PDAC). MethodsPlasma small extracellular vesicles (sEV) from 106 participants, including 20 healthy controls (HC), 12 chronic pancreatitis (CP) patients, 12 benign pancreatic tumour (BPT) patients, and 58 PDAC patients, were profiled for microRNA (miRNA) sequencing. Three machine learning methods were applied to establish and evaluate the diagnostic model. ResultsThe plasma sEV miRNA diagnostic signature (d-signature) selected using the three machine learning methods could distinguish PDAC patients from non-PDAC individuals, HC, and benign pancreatic disease (BPD, CP plus BPT) both in training and validation cohort. Combining the d-signature with carbohydrate antigen 19-9 (CA19-9) performed better than with each model alone. Plasma sEV miR-664a-3p was selected by all methods and used to predict PDAC diagnosis with high accuracy combined with CA19-9. Plasma sEV miR-664a-3p was significantly positively associated with the presence of vascular invasion, lower surgery ratio, and poor differentiation. MiR-664a-3p was mainly distributed in the PDAC cancer stroma, including fibers and vessels, and was accompanied by VEGFA expression. Overexpression of miR-664a-3p could promote the epithelial-mesenchymal transition (EMT) and angiogenesis. ConclusionIn conclusion, our study demonstrated the potential utility of the sEV-miRNA d-signature in the diagnosis of PDAC via machine learning methods. A novel sEV biomarker, miR-664a-3p, was identified for the diagnosis of PDAC. It can also potentially promote angiogenesis and metastasis, provide insight into PDAC pathogenesis, and reveal novel regulators of this disease.

Identifying Serum Small Extracellular Vesicle MicroRNA as a Noninvasive Diagnostic and Prognostic Biomarker for Ovarian Cancer.

There remains a lack of effective and noninvasive methods for the diagnosis and prognosis prediction of epithelial ovarian carcinoma (EOC). Here, we investigated the possibility of serum-derived small extracellular vesicle (sEV) microRNAs (miRNAs) as potential biomarkers for distinguishing between benign and malignant adnexal masses and predicting the prognosis of EOC patients. A serum sEV miRNA model for identifying the EOC (sEVmiR-EOC) was successfully established in the training cohort. Furthermore, the sEVmiR-EOC model was confirmed in the testing cohort and validation cohort, demonstrating robust diagnostic accuracy. The sEVmiR-EOC model showed better performance than carbohydrate antigen 125 (CA125) in discriminating patients with stage I EOC from benign patients. Using EOC samples and follow-up data, we identified miR-141-3p and miR-200c-3p as potential prognostic predictors. Finally, we confirmed the change of the sEVmiR-EOC RiskScore between the preoperative and postoperative samples and found that the sEVmiR-EOC model could predict the prognosis of EOC patients.

MicroRNA Cargo in Wharton’s Jelly MSC Small Extracellular Vesicles: Key Functionality to In Vitro Prevention and Treatment of Premature White Matter Injury

SummaryPreterm birth is the leading cause of childhood morbidity and mortality and can result in white matter injury (WMI), leading to long-term neurological disabilities with global health burden. Mesenchymal stromal cell-derived small extracellular vesicles (MSC-sEV) are a promising therapeutic agent for treating perinatal neurological injury. They carry microRNAs (miRNAs) predicted to be involved in the onset of premature WMI. We hypothesize that miRNAs have a key function in the beneficial effects of MSC-sEV. We isolated MSC from umbilical cord tissue, the Wharton’s jelly (WJ), and purified small extracellular vesicles (sEV) from WJ-MSC culture supernatant by ultracentrifugation and size exclusion chromatography. The miRNA content was quantified by real-time polymerase chain reaction. A luciferase gene assay validated silencing of TP53 and TAOK1, which we previously identified as predicted target genes of MSC-sEV miRNAs by Next Generation Sequencing and pathway enrichment analysis. The impact of sEV miRNAs on oligodendroglial maturation and neuronal apoptosis was evaluated using an in vitro oxygen-glucose deprivation model (OGD/R) by knocking-down DROSHA in WJ-MSC, which initiates miRNA processing. WJ-MSC-sEV contained miRNAs involved in WMI, namely hsa-miR-22-3p, hsa-miR-21-5p, hsa-miR-27b-3p, and the hsa-let-7 family. The luciferase assay strongly indicated an inhibitory effect of sEV miRNAs on the gene expression of TP53 and TAOK1. Small EV initiated oligodendrocyte maturation and reduced OGD/R-mediated neuronal apoptosis. Knocking-down DROSHA in WJ-MSC reduced the expression of sEV miRNAs and led to the loss of their beneficial effects. Our in vitro study strongly indicates the key function of miRNAs in the therapeutic potential of WJ-MSC-sEV in premature WMI.

CD10-Bound Human Mesenchymal Stem/Stromal Cell-Derived Small Extracellular Vesicles Possess Immunomodulatory Cargo and Maintain Cartilage Homeostasis under Inflammatory Conditions.

The onset and progression of human inflammatory joint diseases are strongly associated with the activation of resident synovium/infrapatellar fat pad (IFP) pro-inflammatory and pain-transmitting signaling. We recently reported that intra-articularly injected IFP-derived mesenchymal stem/stromal cells (IFP-MSC) acquire a potent immunomodulatory phenotype and actively degrade substance P (SP) via neutral endopeptidase CD10 (neprilysin). Our hypothesis is that IFP-MSC robust immunomodulatory therapeutic effects are largely exerted via their CD10-bound small extracellular vesicles (IFP-MSC sEVs) by attenuating synoviocyte pro-inflammatory activation and articular cartilage degradation. Herein, IFP-MSC sEVs were isolated from CD10High- and CD10Low-expressing IFP-MSC cultures and their sEV miRNA cargo was assessed using multiplex methods. Functionally, we interrogated the effect of CD10High and CD10Low sEVs on stimulated by inflammatory/fibrotic cues synoviocyte monocultures and cocultures with IFP-MSC-derived chondropellets. Finally, CD10High sEVs were tested in vivo for their therapeutic capacity in an animal model of acute synovitis/fat pad fibrosis. Our results showed that CD10High and CD10Low sEVs possess distinct miRNA profiles. Reactome analysis of miRNAs highly present in sEVs showed their involvement in the regulation of six gene groups, particularly those involving the immune system. Stimulated synoviocytes exposed to IFP-MSC sEVs demonstrated significantly reduced proliferation and altered inflammation-related molecular profiles compared to control stimulated synoviocytes. Importantly, CD10High sEV treatment of stimulated chondropellets/synoviocyte cocultures indicated significant chondroprotective effects. Therapeutically, CD10High sEV treatment resulted in robust chondroprotective effects by retaining articular cartilage structure/composition and PRG4 (lubricin)-expressing cartilage cells in the animal model of acute synovitis/IFP fibrosis. Our study suggests that CD10High sEVs possess immunomodulatory miRNA attributes with strong chondroprotective/anabolic effects for articular cartilage in vivo. The results could serve as a foundation for sEV-based therapeutics for the resolution of detrimental aspects of immune-mediated inflammatory joint changes associated with conditions such as osteoarthritis (OA).

MiR-142-3p encapsulated in T lymphocyte-derived tissue small extracellular vesicles induces Treg function defect and thyrocyte destruction in Hashimoto’s thyroiditis

BackgroundHashimoto’s thyroiditis (HT) is an organ-specific autoimmune disease characterized by lymphocyte infiltration that destroys thyrocyte cells. The aim of the present study was to elucidate the role and mechanisms of tissue small extracellular vesicle (sEV) microRNAs (miRNAs) in the pathogenesis of HT.MethodsDifferentially expressed tissue sEV miRNAs were identified between HT tissue and normal tissue by RNA sequencing in the testing set (n = 20). Subsequently, using quantitative real-time polymerase chain reaction (qRT‒PCR) assays and logistic regression analysis in the validation set (n = 60), the most relevant tissue sEV miRNAs to HT were verified. The parental and recipient cells of that tissue sEV miRNA were then explored. In vitro and in vivo experiments were further performed to elucidate the function and potential mechanisms of sEV miRNAs that contribute to the development of HT.ResultsWe identified that miR-142-3p encapsulated in T lymphocyte-derived tissue sEVs can induce Treg function defect and thyrocyte destruction through an intact response loop. Inactivation of miR-142-3p can effectively protect non-obese diabetic (NOD).H-2h4 mice from HT development display reduced lymphocyte infiltration, lower antibody titers, and higher Treg cells. Looking at the mechanisms underlying sEV action on thyrocyte destruction, we found that the strong deleterious effect mediated by tissue sEV miR-142-3p is due to its ability to block the activation of the ERK1/2 signaling pathway by downregulating RAC1.ConclusionsOur findings highlight the fact that tissue sEV-mediated miR-142-3p transfer can serve as a communication mode between T lymphocytes and thyrocyte cells in HT, favoring the progression of HT.

Preliminary study using a small plasma extracellular vesicle miRNA panel as a potential biomarker for early diagnosis and prognosis in laryngeal cancer.

Plasma extracellular vesicle (EV) miRNAs are important biomarkers for body fluid biopsy. The purpose of this study was to screen and construct a plasma small EV (sEV) miRNA panel as a biomarker for diagnosis and prognosis in laryngeal squamous cell carcinoma (LSCC). Plasma sEV miRNAs from 6 LSCC patients with three typical anatomical sites and 3 normal controls (NCs) were analyzed by next-generation sequencing. The aberrant expression profile of sEV miRNAs was compared with the online databases of LSCC to construct and verify the diagnostic and prognostic panel by machine learning. Additionally, quantitative real-time polymerase chain reaction (qRT‒PCR) was performed to validate the diagnostic efficacy of the screened miRNAs in an independent clinical cohort. A plasma sEV miRNA panel (consisting of hsa-miR-139-3p, hsa-miR-486-5p, hsa-miR-944, hsa-miR-320b and hsa-miR-455-5p) was successfully constructed for the early diagnosis and prognosis of LSCC and showed good predictive potential with AUCs of 0.782, 1.000, 0.716, and 0.875 by an artificial neural network (ANN) panel in independent datasets. This panel was further validated in an independent cohort consisting of 84 clinical cases (48 LSCC and 36 NCs). In the validation cohort, the AUC of the 5 individual miRNAs ranged from 0.721 to 0.837. The accuracy was further increased by the logistic model, which further increased the AUC to 0.959 by adjusting for the number of miRNAs. The miRNA‒mRNA regulatory network and immune function analysis revealed the possible underlying pathogenesis of LSCC. Plasma sEV miRNA panels can be promising plasma biomarkers for predicting early diagnosis and prognosis in LSCC.

Therapeutic Role of microRNAs of Small Extracellular Vesicles from Human Mesenchymal Stromal/Stem Cells in Treatment of Experimental Traumatic Brain Injury.

Mesenchymal stem/stromal cells (MSC)-derived small extracellular vesicles (sEVs) possess therapeutic potential for treatment of traumatic brain injury (TBI). The essential role of micro ribonucleic acids (miRNAs) underlying the beneficial effects of MSC-derived sEVs for treatment of TBI remains elusive. The present study was designed to investigate the role of microRNAs in sEVs from MSCs with Argonaute 2 knockdown (Ago2-KD) in neurological recovery, neuroinflammation, and neurovascular remodeling in TBI rats. Therapeutic effects of sEVs derived from naïve MSCs (naïve-sEV), MSCs transfected with a vector carrying scramble control short hairpin RNA (shRNA; vector-sEV), and MSCs transfected with a lentiviral vector-based shRNA against Ago2 to knock down Ago2 (Ago2-KD-sEV) were determined in adult male rats subjected to a moderate TBI induced by controlled cortical impact (CCI). sEVs (naïve-sEV, vector-sEV, and Ago2-KD-sEV) or vehicle (phosphate-buffered solution [PBS]) were given intravenously 1 day post-injury (PI). Multiple neurological functional tests were performed weekly PI for 5 weeks. The Morris water maze (MWM) test was performed for spatial learning and memory 31-35 days PI. All animals were euthanized 5 weeks PI and the brains were collected for analyses of lesion volume, cell loss, neurovascular remodeling, and neuroinflammation. Ago2-KD reduced global sEV miRNA levels. Compared with the vehicle treatment, both naïve-sEV and vector-sEV treatments significantly improved functional recovery, reduced hippocampal neuronal cell loss, inhibited neuroinflammation, and promoted neurovascular remodeling (angiogenesis and neurogenesis). However, Ago2-KD-sEV treatment had a significantly less therapeutic effect on all the parameters measured above than did naïve-sEV and vector-sEV treatments. The therapeutic effects of Ago2-KD-sEV were comparable to that of vehicle treatment. Our findings demonstrate that attenuation of Ago2 protein in MSCs reduces miRNAs in MSC-derived sEVs and abolishes exosome treatment-induced beneficial effects in TBI recovery, suggesting that miRNAs in MSC-derived sEVs play an essential role in reducing neuronal cell loss, inhibiting neuroinflammation, and augmenting angiogenesis and neurogenesis, as well as improving functional recovery in TBI. The findings underscore the important role of miRNAs in MSC-derived sEVs in the treatment of TBI.

A comparative analysis of small extracellular vesicle (sEV) micro-RNA (miRNA) isolation and sequencing procedures in blood plasma samples

Aims: Analysis of miRNA (18-23nt) encapsulated in small extracellular vesicles (sEVs) (diameter ~30-200 nm) is critical in understanding the diagnostic and therapeutic value of sEV miRNA. However, various sEV enrichment techniques yield different quantities and qualities of sEV miRNA. Here, we compare the efficacy of three sEV isolation techniques in four combinations for miRNA next-generation sequencing. Methods: Blood plasma from four Holstein-Friesian dairy cows (Bos taurus) (n = 4) with similar genetic traits and physical characteristics were pooled to isolate sEV. Ultracentrifugation (UC) (100,000 × g, 2 h at 4 °C), size-exclusion chromatography (SEC) and ultrafiltration (UF) were used to design four groups of sEV isolations (UC+SEC, SEC+UC, SEC+UF and UC+SEC+UF). sEV miRNAs were isolated using a combination of TRIzol, Chloroform and miRNeasy mini kit (n = 4/each), later sequenced utilizing Novaseq S1 platform (single-end 100 bp sequencing). Results: All four sEV methods yielded > 1,700 miRNAs and sEV miRNAs demonstrated a clear separation from control blood plasma circulating miRNA (PCA analysis). MiR-381-3p, miR-23-3p, and miR-18b-3p are among the 25 miRNAs unique to sEV, indicating potential sEV-specific miRNA markers. Further, those 25 miRNAs mostly regulate immune-related functions, indicating the value of sEV miRNA cargo in immunology. Conclusion: The four sEV miRNA isolation methods employed in this study are valid techniques. The choice of method depends on the research question and study design. If purity is of concern, the UC+SEC method resulted in the best particles/µg protein ratio, which is often used as an indication of sample purity. These results could eventually establish sEV miRNAs as effective diagnostic and therapeutic tools of immunology.

Abstract 12912: Metabolic Labeling of Cardiomyocyte-Derived Small Extracellular-Vesicle (sEV) MiRNAs Identifies MiR-208a in Cardiac Regulation of Lung Gene Expression

Background & Hypothesis: T. gondii uracil phosphoribosyltransferase (UPRT) can convert 4-thiouracil(4TUc) into 4-thiouridine (4TUd), thus incorporating into nascent RNAs, and the thio-labeled RNAs can be identified by thio-linked-biotinylation and streptavidin-affinity isolation, we hypothesize that cardiomyocyte (CM) expression of UPRT ( CM UPRT) allows labeling and tracking of CM-derived miRNAs in PB sEV and peripheral organs. Methods & Results: We generated mice that expressed T. gondii UPRT only in cardiomyocytes ( CM UPRT mice) and tested our hypothesis that CM-derived miRNAs ( CM miRs) are transferred into remote organs after myocardial infarction (MI) by PB sEV. We found that 4TUd was incorporated with high specificity and sensitivity into RNAs isolated from the hearts and PB sEV of CM UPRT mice six hours after 4TUc injection. In PB sEV, 4TUd was incorporated into CM-specific/enriched miRs including miR-208a, but not into miRs with other organ or tissue-type specificities. 4TUd-labeled miR208a was also present in lung tissues, especially lung endothelial cells (ECs), and CM-derived miR-208a ( CM miR-208a) levels peaked 12 hours after experimentally induced MI in PB sEV and 24 hours after MI in the lung. Notably, miR-208a is expressed from intron 29 of α myosin heavy chain (αMHC), but αMHC transcripts were nearly undetectable in the lung. When PB sEV from mice that underwent MI (MI- PB sEV) or sham surgery (Sham- PB sEV) were injected into intact mice, the expression of Tmbim6 and NLK, which are suppressed by miR-208a and cooperatively regulate inflammation via the NF-κB pathway, was lower in the lungs of MI- PB sEV-treated animals than the lungs of animals treated with Sham- PB sEV or saline. In MI mice, Tmbim6 and NLK were downregulated, whereas endothelial adhesion molecules and pro-inflammatory cells were upregulated in the lung; these changes were significantly attenuated when the mice were treated with miR-208a antagomirs prior to MI surgery. Conclusion: CM UPRT mice enables us to track PB sEV-mediated transport of CM miRs and identify an miR-208a-mediated mechanism by which myocardial injury alters the expression of genes and inflammatory response in the lung.

Evaluation of circulating small extracellular vesicle-derived miRNAs as diagnostic biomarkers for differentiating between different pathological types of early lung cancer

Lung cancer is the leading cause of cancer-related death worldwide. MicroRNAs (miRNAs) in circulating small extracellular vesicles (sEVs) have been suggested to be potential biomarkers for cancer diagnosis. The present study was designed to explore whether plasma-derived sEV miRNAs could be utilized as diagnostic biomarkers for differentiating between early-stage small cell lung cancer (SCLC) and early-stage non-small cell lung cancer (NSCLC). We compared the miRNA profiles of plasma-derived sEVs from healthy individuals, patients with early-stage SCLC and patients with early-stage NSCLC. Next-generation sequencing was used to screen for differentially expressed miRNAs (DEMs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to predict the potential functions of these DEMs. Weighted gene coexpression network analysis (WGCNA) was used to identify the different pathology-related miRNA modules. We found that 22 DEMs were significantly different among healthy individuals, patients with early-stage SCLC, and patients with early-stage NSCLC. We selected six representative DEMs for validation by qRT‒PCR, which confirmed that miRNA-483-3p derived from plasma sEVs could be used as a potential biomarker for the diagnosis of early-stage SCLC, miRNA-152-3p and miRNA-1277-5p could be used for the diagnosis of early-stage NSCLC respectively.

Atrophic skeletal muscle fibre-derived small extracellular vesicle miR-690 inhibits satellite cell differentiation during ageing.

Sarcopenia is a common and progressive skeletal muscle disorder characterized by atrophic muscle fibres and contractile dysfunction. Accumulating evidence shows that the number and function of satellite cells (SCs) decline and become impaired during ageing, which may contribute to impaired regenerative capacity. A series of myokines/small extracellular vesicles (sEVs) released from muscle fibres regulate metabolism in muscle and extramuscular tissues in an autocrine/paracrine/endocrine manner during muscle atrophy. It is still unclear whether myokines/sEVs derived from muscle fibres can affect satellite cell function during ageing. Aged mice were used to investigate changes in the myogenic capacity of SCs during ageing-induced muscle atrophy. The effects of atrophic myotube-derived sEVs on satellite cell differentiation were investigated by biochemical methods and immunofluorescence staining. Small RNA sequencing was performed to identify differentially expressed sEV microRNAs (miRNAs) between the control myotubes and atrophic myotubes. The target genes of the miRNA were predicted by bioinformatics analysis and verified by luciferase activity assays. The effects of identified miRNA on the myogenic capacity of SCs in vivo were investigated by intramuscular injection of adeno-associated virus (AAV) to overexpress or silence miRNA in skeletal muscle. Our study showed that the myogenic capacity of SCs was significantly decreased (50%, n=6, P<0.001) in the tibialis anterior muscle of aged mice. We showed that atrophic myotube-derived sEVs inhibited satellite cell differentiation in vitro (n=3, P<0.001) and in vivo (35%, n=6, P<0.05). We also found that miR-690 was the most highly enriched miRNA among all the screened sEV miRNAs in atrophic myotubes [Log2 (Fold Change)=7, P<0.001], which was verified in the atrophic muscle of aged mice (threefold, n=6, P<0.001) and aged men with mean age of 71±5.27years (2.8-fold, n=10, P<0.001). MiR-690 can inhibit myogenic capacity of SCs by targeting myocyte enhancer factor 2, including Mef2a, Mef2c and Mef2d, in vitro (n=3, P<0.05) and in vivo (n=6, P<0.05). Specific silencing of miR-690 in the muscle can promote satellite cell differentiation (n=6, P<0.001) and alleviate muscle atrophy in aged mice (n=6, P<0.001). Our study demonstrated that atrophic muscle fibre-derived sEV miR-690 may inhibit satellite cell differentiation by targeting myocyte enhancer factor 2 during ageing.

A reducible comparison of 2D vs. 3D HepG2 culture‐derived sEV characteristics and cancer pathway‐related miRNA content

Hepatocellular carcinoma cells (HCCs) produce small extracellular vesicles (sEVs or exosomes) to enable tumor survival, including inactivation of anti‐tumor macrophage immune responses. For sEV studies in vitro, 2D adherent culture cells are typically used to manufacture sEVs. In contrast, 3D matrix‐based culture systems closely simulate in vivo tissues but produce difficult to isolate sEVs. To address this issue, we developed a reducible 3D suspension HCC spheroid culture system to generate easily obtainable sEVs for investigations. The objective was to evaluate biophysical and cancer pathway‐focused miRNA content differences between HCC HepG2 sEVs produced in 2D adherent vs. 3D spheroid suspension culture. To summarize methods, sEVs were isolated from 2D and 3D cell culture using differential ultracentrifugation and size and zeta potential biophysical characteristics were determined by nanoparticle tracking analysis. Fold regulation of 2D and 3D derived sEV miRNAs, compared to their source cells and one another, were determined by qRT‐PCR, and statistically significant differences were determined by Student’s t‐test. Results indicated that HepG2 sEVs generated from 2D adherent or 3D spheroid suspension culture do not differ significantly in terms of size (~130 nm) and zeta potential (&lt; ‐30 mV) characteristic of sEVs. A comparison of 2D vs. 3D sEVs revealed differences in the enrichment of let‐7a‐5p (decreased in HCC in vivo), miR‐21‐5p (enables HCC drug resistance), and miR‐126‐3p (impairs HCC tumor volume in vivo). let‐7a‐5p and miR‐21‐5p were downregulated, while miR‐126‐3p was upregulated in 3D sEVs compared to 2D sEVs (control) respectively. Overall, similarities and differences between 2D and 3D sEV miRNA content were observed relevant to HCC pathogenesis. In conclusion, the 3D HepG2 spheroid suspension model provides an additional reducible level of HCC sEV investigation to augment traditional 2D sEV studies while better simulating an in vivo 3D source of easily obtainable HCC sEVs. Our 3D model could be used in conjunction with typical 2D EV culture systems to streamline the identification of candidate sEV‐based biomarkers and therapeutic targets for HCC and other cancers.

MiR-10a, miR-30c, and miR-451a Encapsulated in Small Extracellular Vesicles Are Prosenescence Factors in Human Dermal Fibroblasts

Although small extracellular vesicles (sEV) have been reported to play an important role in cellular senescence and aging, little is known about the potential role and function of microRNAs (miRNAs) contained within the sEV. To determine the senescence-associated factors secreted from sEV of human dermal fibroblasts (HDFs), we isolated and characterized sEV from nonsenescent versus that from senescent HDFs. Small RNA-sequencing analysis identified many enriched miRNAs in sEV of senescent HDF, as shown by the upregulation of miR-10a, miR-30c, and miR-451a and downregulation of miR-128, miR-184, miR-200c, and miR-125a. Overexpression of miR-10a, miR-30c, and miR-451a induced an aging phenotype in HDFs, whereas inhibition of these miRNAs reduced senescent-like phenotypes in senescent HDFs. Moreover, treatment with sEV or sEV-containing conditioned medium promoted cellular senescence in HDFs, whereas sEV depletion abrogated prosenescence effects of the senescent HDF secretome. Interestingly, prosenescence sEV miRNAs were found to have an essential role in regulating ROS production and mitophagy activation. Taken together, our results revealed miR-10a, miR-30c, and miR-451a as prosenescence factors that are differentially expressed in sEV of senescent HDFs, showing the essential role of sEV miRNAs in the biological processes of aging.