Isolation and Identification of miRNAs in exosomes derived from serum of colon cancer patients

MiRNAs in Extracellular Vesicles as Biomarkers in Plasma of Papillary Thyroid Cancer Patients: A Proof-of-Concept Study

BACKGROUND

The incidence of various types of cancer, for example, papillary thyroid carcinoma (PTC), is on the rise. Since therapeutic success depends greatly on early diagnosis, reliable diagnostic biomarkers must be identified, and easy-to-apply tools for detecting them must urgently be standardized. Here, we contribute to solving this medical challenge by assessing miRNAs suspected of promoting carcinogenesis in extracellular vesicles (EVs) that can be routinely obtained via liquid biopsy. We profit from current progress in cancerology that provides innovations in liquid biopsy and EVs analysis, along with the identification of miRNAs and chaperone system (CS) components implicated in carcinogenesis.

METHODS

We measured in EVs obtained from circulating blood plasma from PTC patients the levels of three miRNAs implicated in thyroid cancer, hsa-miR-1-3p, hsa-miR-206, and hsa-miR-221-3p, and most likely involved in the regulation of two members of the CS, Hsp60 and CCT. EVs were isolated from the plasma of patients with PTC and controls with benign goiter (BG) and from the culture medium of a PTC cell line (MDAT32) and were appropriately characterized.

RESULTS

The levels of miRNAs determined by RT-qPCR were consistently higher in PTC patients and decreased down to control levels after thyroidectomy. Bioinformatics showed that the miRNAs target genes are associated with the molecular pathogenesis of PTC.

CONCLUSIONS

Our exploratory study reaffirms the potential in clinics of the selected miRNAs in EVs as useful biomarkers of PTC easily accessible via liquid biopsy, which is minimally invasive and amenable to periodic repetition, an improvement compared to the established fine-needle aspirate biopsy.

Mesenchymal stromal/stem cell tissue source and in vitro expansion impact extracellular vesicle protein and miRNA compositions as well as angiogenic and immunomodulatory capacities

Recently, therapies utilizing extracellular vesicles (EVs) derived from mesenchymal stromal/stem cells (MSCs) have begun to show promise in clinical trials. However, EV therapeutic potential varies with MSC tissue source and in vitro expansion through passaging. To find the optimal MSC source for clinically translatable EV-derived therapies, this study aims to compare the angiogenic and immunomodulatory potentials and the protein and miRNA cargo compositions of EVs isolated from the two most common clinical sources of adult MSCs, bone marrow and adipose tissue, across different passage numbers. Primary bone marrow-derived MSCs (BMSCs) and adipose-derived MSCs (ASCs) were isolated from adult female Lewis rats and expanded in vitro to the indicated passage numbers (P2, P4, and P8). EVs were isolated from the culture medium of P2, P4, and P8 BMSCs and ASCs and characterized for EV size, number, surface markers, protein content, and morphology. EVs isolated from different tissue sources showed different EV yields per cell, EV sizes, and protein yield per EV. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of proteomics data and miRNA seq data identified key proteins and pathways associated with differences between BMSC-EVs and ASC-EVs, as well as differences due to passage number. In vitro tube formation assays employing human umbilical vein endothelial cells suggested that both tissue source and passage number had significant effects on the angiogenic capacity of EVs. With or without lipopolysaccharide (LPS) stimulation, EVs more significantly impacted expression of M2-macrophage genes (IL-10, Arg1, TGFβ) than M1-macrophage genes (IL-6, NOS2, TNFα). By correlating the proteomics analyses with the miRNA seq analysis and differences observed in our in vitro immunomodulatory, angiogenic, and proliferation assays, this study highlights the trade-offs that may be necessary in selecting the optimal MSC source for development of clinical EV therapies.

Comparison of morphology, protein concentration, and size distribution of bone marrow and Wharton's jelly-derived mesenchymal stem cells exosomes isolated by ultracentrifugation and polymer-based precipitation techniques

Exosomes which are tiny extracellular vesicles (30-150 nm), transport vital proteins and gene materials such as miRNA, mRNA, or DNA, whose role in cell communication and epithelia regulation is critical. Many techniques have been developed as a result of studying exosomes' biochemical and physicochemical properties, although there is still no standard method to isolate exosomes simply with high yield. Commercial kits have gained popularity for exosome extraction despite concerns about their effectiveness in scientific research. On the other hand, ultracentrifugation remains the gold standard isolation method. This study compares these two common exosome isolation methods to determine their impact on the quality and quantity of exosomes isolated from bone marrow (BM) and Wharton's jelly (WJ)-derived mesenchymal stem cells. Isolated exosomes from the two sources of the cell's conditioned medium by two methods (polymer kit and ultracentrifuge) were characterized using western blotting, scanning electron microscopy (SEM), dynamic light scattering (DLS), and the Bradford assay. Western blot analysis confirmed separation efficiency based on CD81 and CD63 markers, with the absence of calnexin serving as a negative control. The Morphology of exosomes studied by SEM image analysis revealed a similar round shape appearance and their sizes (30-150 nm) were the same in both isolation techniques. The DLS analysis of the sample results was consistent with the SEM ones, showing a similar size range and very low disparity. The exosome protein content concentration analysis revealed that exosomes isolated by the polymer-based kits contained higher protein concentration density and purity (p <0.001). In general, though the protein yield was higher when the polymer-based kits were used, there were no significant differences in morphology, or size between WJ-derived and BM-derived exosomes, regardless of the isolation method employed.

An overview of challenges associated with exosomal miRNA isolation toward liquid biopsy-based ovarian cancer detection

As one of the deadliest gynaecological cancers, ovarian cancer has been on the list. With lesser-known symptoms and lack of an accurate detection method, it is still difficult to catch it early. In terms of both the diagnosis and outlook for cancer, liquid biopsy has come a long way with significant advancements. Exosomes, extracellular components commonly shed by cancerous cells, are nucleic acid-rich particles floating in almost all body fluids and hold enormous promise, leading to minimallyinvasive molecular diagnostics. They have been shown as potential biomarkers in liquid biopsy, being implicated in tumour growth and metastasis. In order to address the drawbacks of ovarian cancer tumor heterogeneity, a liquid biopsy-based approach is being investigated by detecting cell-free nucleic acids, particularly non-coding RNAs, having the advantage of being less invasive and more prominent in nature. microRNAs are known to actively contribute to cancer development and their existence inside exosomes has also been made quite apparent which can be leveraged to diagnose and treat the disease. Extraction of miRNAs and exosomes is an arduous execution, and while other approaches have been investigated, none have produced results that are as encouraging due to limits in time commitment, yield, and, most significantly, damage to the exosomal structure resulting discrepancies in miRNA-based expression profiling for disease diagnosis. We have briefly outlined and reviewed the difficulties with exosome isolation techniques and the need for their standardization. The several widely used procedures and their drawbacks in terms of the exosomal purity they may produce have also been outlined.

MicroRNA-148a-3p in pericyte-derived extracellular vesicles improves erectile function in diabetic mice by promoting cavernous neurovascular regeneration

BACKGROUND

To investigate the regulatory role of microRNA (miR)-148a-3p in mouse corpus cavernous pericyte (MCPs)-derived extracellular vesicles (EVs) in the treatment of diabetes-induced erectile dysfunction (ED).

METHODS

Mouse corpus cavernous tissue was used for MCP primary culture and EV isolation. Small-RNA sequencing analysis was performed to assess the type and content of miRs in MCPs-EVs. Four groups of mice were used: control nondiabetic mice and streptozotocin-induced diabetic mice receiving two intracavernous injections (days - 3 and 0) of phosphate buffered saline, MCPs-EVs transfected with reagent control, or MCPs-EVs transfected with a miR-148a-3p inhibitor. miR-148a-3p function in MCPs-EVs was evaluated by tube-formation assay, migration assay, TUNEL assay, intracavernous pressure, immunofluorescence staining, and Western blotting.

RESULTS

We extracted EVs from MCPs, and small-RNA sequencing analysis showed miR-148a-3p enrichment in MCPs-EVs. Exogenous MCPs-EV administration effectively promoted mouse cavernous endothelial cell (MCECs) tube formation, migration, and proliferation, and reduced MCECs apoptosis under high-glucose conditions. These effects were significantly attenuated in miR-148a-3p-depleted MCPs-EVs, which were extracted after inhibiting miR-148a-3p expression in MCPs. Repetitive intracavernous injections of MCPs-EVs improved erectile function by inducing cavernous neurovascular regeneration in diabetic mice. Using online bioinformatics databases and luciferase report assays, we predicted that pyruvate dehydrogenase kinase-4 (PDK4) is a potential target gene of miR-148a-3p.

CONCLUSIONS

Our findings provide new and reliable evidence that miR-148a-3p in MCPs-EVs significantly enhances cavernous neurovascular regeneration by inhibiting PDK4 expression in diabetic mice.

Paper-Based Exosomal MicroRNA-21 Detection for Wound Monitoring: A Proof of Concept and Clinical Validation Trial Study

Emerging evidence has shown that microRNAs play pivotal roles in wound healing. MicroRNA-21 (miR-21) was previously found to upregulate in order to fulfill an anti-inflammation role for wounds. Exosomal miRNAs have been identified and explored as essential markers for diagnostic medicine. However, the role of exosomal miR-21 in wounds has yet to be well studied. In order to facilitate the early management of poorly healing wounds, we developed an easy-to-use, rapid, paper-based microfluidic-exosomal miR-21 extraction device to determine wound prognosis in a timely manner. We isolated and then quantitatively examined exosomal miR-21 in wound fluids from normal tissues and acute and chronic wounds. Eight improving wounds displayed lower levels of exosomal miR-21 expression after wound debridement. However, four instances of increased exosomal miR-21 expression levels were notably associated with patients with poor healing wounds despite aggressive wound debridement, indicating a predictive role of tissue exosomal miR-21 for wound outcome. Paper-based nucleic acid extraction device provides a rapid and user-friendly approach for evaluating exosomal miR-21 in wound fluids as a means of monitoring wounds. Our data suggest that tissue exosomal miR-21 is a reliable marker for determining current wound status.

Exosome-mediated regulatory mechanisms in skeletal muscle: a narrative review

Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.

Epithelial senescence in idiopathic pulmonary fibrosis is propagated by small extracellular vesicles

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that affects 3 million people worldwide. Senescence and small extracellular vesicles (sEVs) have been implicated in the pathogenesis of IPF, although how sEVs promote disease remains unclear. Here, we profile sEVs from bronchial epithelial cells and determine small RNA (smRNA) content.

METHODS

Conditioned media was collected and sEVs were isolated from normal human bronchial epithelial cells (NHBEs) and IPF-diseased human bronchial epithelial cells (DHBEs).

RESULTS

Increased sEV release from DHBEs compared to NHBEs (n = 4; p < 0.05) was detected by nanoparticle tracking analysis. NHBEs co-cultured with DHBE-derived sEVs for 72 h expressed higher levels of SA-β-Gal and γH2AX protein, p16 and p21 RNA and increased secretion of IL6 and IL8 proteins (all n = 6-8; p < 0.05). sEVs were also co-cultured with healthy air-liquid interface (ALI) cultures and similar results were observed, with increases in p21 and p16 gene expression and IL6 and IL8 (basal and apical) secretion (n = 6; p < 0.05). Transepithelial electrical resistance (TEER) measurements, a reflection of epithelial barrier integrity, were decreased upon the addition of DHBE-derived sEVs (n = 6; p < 0.05). smRNA-sequencing identified nineteen significantly differentially expressed miRNA in DHBE-derived sEVs compared to NHBE-derived sEVs, with candidate miRNAs validated by qPCR (all n = 5; p < 0.05). Four of these miRNAs were upregulated in NHBEs co-cultured with DHBE-derived sEVs and three in healthy ALI cultures co-cultured with DHBE-derived sEVs (n = 3-4; p < 0.05).

CONCLUSIONS

This data demonstrates that DHBE-derived sEVs transfer senescence to neighbouring healthy cells, promoting the disease state in IPF.

Advances in exosome analysis

There is growing demand for novel biomarkers that detect early stage disease as well as monitor clinical management and therapeutic strategies. Exosome analysis could provide the next advance in attaining that goal. Exosomes are membrane encapsulated biologic nanometric-sized particles of endocytic origin which are released by all cell types. Unfortunately, exosomes are exceptionally challenging to characterize with current technologies. Exosomes are between 30 and 200nm in diameter, a size that makes them out of the sensitivity range to most cell-oriented sorting or analysis platforms, i.e., traditional flow cytometers. The most common methods for targeting exosomes to date typically involve purification followed by the characterization and the specific determination of their cargo. The whole procedure is time consuming, requiring thus skilled personnel as well as laboratory facilities and benchtop instrumentation. The most relevant methodology for exosome isolation, characterization and quantification is addressed in this chapter, including the most up-to-date approaches to explore the potential usefulness of exosomes as biomarkers in liquid biopsies and in advanced nanomedicine.

Effective Separation of Cancer-Derived Exosomes in Biological Samples for Liquid Biopsy: Classic Strategies and Innovative Development

Liquid biopsy has remarkably facilitated clinical diagnosis and surveillance of cancer via employing a non-invasive way to detect cancer-derived components, such as circulating tumor DNA and circulating tumor cells from biological fluid samples. The cancer-derived exosomes, which are nano-sized vesicles secreted by cancer cells have been investigated in liquid biopsy as their important roles in intracellular communication and disease development have been revealed. Given the challenges posed by the complicated humoral microenvironment, which contains a variety of different cells and macromolecular substances in addition to the exosomes, it has attracted a large amount of attention to effectively isolate exosomes from collected samples. In this review, the authors aim to analyze classic strategies for separation of cancer-derived exosomes, giving an extensive discussion of advantages and limitations of these methods. Furthermore, the innovative multi-strategy methods to realize efficient isolation of cancer-derived exosomes in practical applications are also presented. Additionally, the possible development trends of exosome separation in to the future is discussed in this review.

Hydrogel-Embedded Poly(Lactic-co-Glycolic Acid) Microspheres for the Delivery of hMSC-Derived Exosomes to Promote Bioactive Annulus Fibrosus Repair

OBJECTIVE

Intervertebral disk degeneration is a prevalent postoperative complication after discectomy, underscoring the need to develop preventative and bioactive treatment strategies that decelerate degeneration and seal annulus fibrosus (AF) defects. Human mesenchymal stem cell-derived exosomes (MSC-Exos) hold promise for cell-free bioactive repair; however, their ability to promote AF repair is poorly understood. The objective of this study was to evaluate the ability of MSC-Exos to promote endogenous AF repair processes and integrate MSC-Exos within a biomaterial delivery system.

DESIGN

We characterize biophysical and biochemical properties of normoxic (Nx) and hypoxic (Hx) preconditioned MSC-Exos from young, healthy donors and examine their effects on AF cell proliferation, migration, and gene expression. We then integrate a poly(lactic-co-glycolic acid) microsphere (PLGA µSphere) delivery platform within an interpenetrating network hydrogel to facilitate sustained MSC-Exo delivery.

RESULTS

Hx MSC-Exos led to a more robust response in AF cell proliferation and migration than Nx MSC-Exos and was selected for a downstream protection experiment. Hx MSC-Exos maintained a healthy AF cell phenotype under a TNFα challenge in vitro and attenuated catabolic responses. In all functional assays, AF cell responses were more sensitive to Hx MSC-Exos than Nx MSC-Exos. PLGA µSpheres released MSC-Exos over a clinically relevant timescale without affecting hydrogel modulus or pH upon initial embedment and µSphere degradation.

CONCLUSIONS

This MSC-Exo treatment strategy may offer benefits of stem cell therapy without the need for exogenous stem cell transplantation by stimulating cell proliferation, promoting cell migration, and protecting cells from the degenerative proinflammatory microenvironment.

Effects of Anesthetics on Proliferation and Apoptosis of Drug-Resistant Human Colon Cancer Cells

In recent years, people's living standards are getting higher and higher, and life pressure is also increasing, and there are also many problems in eating habits. This is also the direct cause of colon cancer. The aim of this paper was to investigate whether anesthetic drugs could positively affect the proliferation and apoptosis of colon cancer cells. In this paper, the significance of anesthetic drugs is proposed, and an artificial neural network algorithm based on artificial intelligence is proposed. It is well known that artificial neural networks play an important role in medicine. The experimental results of this paper show that the incidence of colon cancer in 2020 will be in the range of 5%-35%, and the incidence of colon cancer in 2021 will be in the range of 7%-30%. While colon cancer rates in 2021 do not appear to be as high as colon cancer rates in 2020, they are generally much higher than colon cancer rates in 2020. It can be seen that as the population ages, the number of colon cancer patients is increasing due to the lack of emphasis on health. This also means that the incidence of colon cancer is getting higher and higher, and traditional drug chemotherapy has been unable to play a good role in inhibiting the proliferation of colon cancer cells. Therefore, this paper investigated the effects of anesthetic drugs on the proliferation and apoptosis of human colon cancer cells.

Downregulated miR-129-5p expression inhibits rat pulmonary fibrosis by upregulating STAT1 gene expression in macrophages

OBJECTIVE

This study investigated the mechanism by which microRNA-129-5p (miR-129-5p) in macrophages affects pulmonary fibrosis in rats by regulating the expression of the signal transducer and activator of transcription 1 (STAT1) gene.

METHODS

After the establishment of a pulmonary fibrosis rat model, quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of miR-129-5p in the sham group and model group. The binding sites between miR-129-5p and STAT1 were predicted online and verified by using a dual luciferase reporter system. qRT-PCR and Western blot analyses were used to test the effect of miR-129-5p on STAT1 gene expression. M2 macrophages were isolated and induced, and exosomes were extracted. Cell proliferation was detected by EdU. Furthermore, qRT-PCR was performed to detect the expression of STAT1, collagen type I A2 (COL1A2), collagen type III A1 (COL3A1), fibronectin, and α-SMA in cells and tissues followed by the detection of CD9, CD63, CD81, CD31 and STAT1 protein expression using a Western blot analysis. The pulmonary fibrosis area was detected by Masson staining followed by the immunohistochemical detection of α-smooth muscle actin (α-SMA) and type I collagen (COL-I) expression in pulmonary fibroblasts.

RESULTS

Compared with the sham group, the expression level of miR-129-5p in the model group was significantly increased (P < 0.05). miR-129-5p was observed to negatively regulate the expression of STAT1 (P < 0.05). The in vitro cell transfection experiments showed that after inhibiting the expression of miR-129-5p, the expression of STAT1 was increased, and the proliferation of fibroblasts and pulmonary fibrosis were inhibited (all P < 0.05). Furthermore, compared with the fibroblasts without coculture, the proliferation of the fibroblasts cocultured with M2 macrophage-secreted exosomes was clearly increased, and the expression levels of COL1A2, COL3A1, fibronectin and α-SMA were significantly increased (all P < 0.05). Compared with the mimic NC-exo group, the miR-129-5p-exo group had significantly increased proliferation of fibroblasts, decreased expression of STAT1, and significantly increased expression of COL1A2, COL3A1, fibronectin and α-SMA, and M2 macrophage-secreted exosomes could carry miR-129-5p to fibroblasts. Furthermore, the in vivo experiment confirmed that the exosomes of M2 macrophages could carry miR-129-5p, which could regulate M2 macrophages with pulmonary fibrosis in vivo.

CONCLUSION

M2 macrophages can carry miR-129-5p to pulmonary interstitial fibroblasts and inhibit STAT1 gene expression, which may lead to the proliferation of fibroblasts and promote pulmonary fibrosis. The downregulation of miR-129-5p can significantly promote STAT1 gene expression in macrophages to inhibit pulmonary fibrosis in rats.

Quantification of Desiccated Extracellular Vesicles by Quartz Crystal Microbalance

Extracellular vesicle (EV) quantification is a procedure through which the biomedical potential of EVs can be used and their biological function can be understood. The number of EVs isolated from cell culture media depends on the cell status and is especially important in studies on cell-to-cell signaling, disease modeling, drug development, etc. Currently, the methods that can be used to quantify isolated EVs are sparse, and each have limitations. In this report, we introduce the application of a quartz crystal microbalance (QCM) as a biosensor for quantifying EVs in a small drop of volatile solvent after it evaporates and leaves desiccated EVs on the surface of the quartz crystal. The shifts in the crystal’s resonant frequency were found to obey Sauerbrey’s relation for EV quantities up to 6 × 10⁷, and it was determined that the biosensors could resolve samples that differ by at least 2.7 × 10⁵ EVs. A ring-shaped pattern enriched in EVs after the samples had dried on the quartz crystal is also reported and discussed. QCM technology is highly sensitive and only requires small sample volumes and is significantly less costly compared with the approaches that are currently used for EV quantification.

MicroRNA Profiling of the Tears of Children With Vernal Keratoconjunctivitis

Vernal Keratoconjunctivitis (VKC) is a chronic conjunctival inflammatory condition that typically affects children. Extracellular microRNAs (miRNAs) are small noncoding RNA molecules, the expression of which is reported to regulate cellular processes implicated in several eye diseases. The aim of this preliminary study is to identify the miRNA expression profile in the tears of children with VKC vis-à-vis controls, and to statistically evaluate these miRNAs as potential diagnostic biomarkers of VKC. The study involved a VKC group and a control group. Tear specimens were collected using Schirmer’s strips. RNA was isolated using miRNeasy Micro kit and quantification was performed using an Agilent Bioanalyzer RNA 6000 Nano kit and Small RNA kit. miRNA profiling was performed using the Agilent microarray technique. A total of 51 miRNAs (48 upregulated and three downregulated) were differentially expressed in the tears of children with VKC and controls. The three most significantly upregulated miRNAs were hsa-miR-1229-5p, hsa-miR-6821-5p, and hsa-miR-6800-5p, and the three most significantly downregulated miRNAs were hsa-miR-7975, hsa-miR-7977, and hsa-miR-1260a. All the upregulated miRNAs are potential diagnostic biomarkers of VKC pending validation due to their larger discriminatory area under the curve (AUC) values. miRNA target prediction analysis revealed multiple overlapping genes that are known to play a role in conjunctival inflammation. We identified a set of differentially expressed miRNAs in the tears of children with VKC that may play a role in VKC pathogenesis. This study serves as the platform study for future miRNA studies that will provide a deeper understanding of the pathophysiology of VKC.

Exosomal RNAs: Novel Potential Biomarkers for Diseases-A Review

Exosomes are a subset of nano-sized extracellular vesicles originating from endosomes. Exosomes mediate cell-to-cell communication with their cargos, which includes mRNAs, miRNAs, lncRNAs, and circRNAs. Exosomal RNAs have cell specificity and reflect the conditions of their donor cells. Notably, their detection in biofluids can be used as a diagnostic marker for various diseases. Exosomal RNAs are ideal biomarkers because their surrounding membranes confer stability and they are detectable in almost all biofluids, which helps to reduce trauma and avoid invasive examinations. However, knowledge of exosomal biomarkers remains scarce. The present review summarizes the biogenesis, secretion, and uptake of exosomes, the current researches exploring exosomal mRNAs, miRNAs, lncRNAs, and circRNAs as potential biomarkers for the diagnosis of human diseases, as well as recent techniques of exosome isolation.

Over-expression of miR-193a-3p regulates the apoptosis of colorectal cancer cells by targeting PAK3

Although dysregulated expression of microRNAs (miRNA) has been investigated in colorectal cancer (CRC), MiR-193a-3p, as a tumor inhibitor, is less studied. To investigate the function and mechanism of miR-193a-3p in CRC, the potential function of miR-193a-3p in regulating PAK3 in CRC with a series of experimental assays including western blotting, qRT-PCR, bioinformatics analysis, a luciferase reporter assay, flow cytometry, Transwell assay, CCK8 assay and immunofluorescence were performed in this study. The results showed that miR-193a-3p was down-regulated in CRC tissues and cell lines, which was also correlated with tumor progression. PAK3 was predicted as a target gene of miR-193a-3p in CRC cells by TargetScan database, which was confirmed by luciferase assays. Moreover, overexpression of miR-193a-3p suppressed the viability, cell cycle progression, migration, and invasion, and induced apoptosis of CRC cells in vitro by regulating the PAK3 signaling pathway. Therefore, miR-193a-3p may serve as a tumor suppressor and potential target for CRC treatment.

Extracellular vesicles in pharmacology: Novel approaches in diagnostics and therapy

Exosomes are nano-sized lipid vesicles that are produced by all eukaryotic cells, and they typically range in size from 30 to 150 nm. Exosomes were discovered almost 40 years ago; however, the last two decades have attracted considerable attention due to exosomes' inherent abilities to shuttle nucleic acids, lipids and proteins between cells, along with their natural affinity to exosome target cells. From a pharmaceutical perspective, exosomes are regarded as naturally produced nanoparticle drug delivery vehicles. The application of exosomes as a means of drug delivery offers critical advantages compared to other nanoparticulate drug delivery systems, such as liposomes and polymeric nanoparticles. These advantages are due to the exosomes' intrinsic features, such as low immunogenicity, biocompatibility, stability, and their ability to overcome biological barriers. Herein, we outline the structure and origin of exosomes, as well as their biological functions. We also touch upon recent advances in exosome labeling, imaging and drug loading. Finally, we discuss exosomes in targeted drug delivery and clinical trial development.

Diagnostic value of using exosome-derived cysteine-rich protein 61 as biomarkers for acute coronary syndrome

Acute coronary syndrome (ACS) is the main manifestation of cardiovascular disease and the primary cause of adult hospitalization in China. There is an urgent demand for novel biomarkers for the diagnosis of ACS. Although plasma cysteine-rich protein 61 (Cyr61) has been previously reported to be accurate for ACS diagnosis, the accuracy of exosomal Cyr61 in ACS diagnosis remains unknown. In the present study, the aim was to assess the potential of applying exosomal Cyr61 in ACS diagnosis and to explore the role of Cyr61 in vascular remodeling in vitro. The abundance of Cyr61 in plasma-derived exosomes from patients with unstable angina pectoris (UAP), acute myocardial infarction (AMI) patients in addition to those isolated from healthy individuals were detected using an ELISA kit. The association between exosomal Cyr61 levels and clinical characteristics of ACS patients was analyzed through χ² test, Fisher's exact test and Student's t-test. Receiver operating characteristic (ROC) curve analysis was used to determine the accuracy of using exosomal Cyr61 as a biomarker of ACS diagnosis. Furthermore, independent predictors of the existence of ACS were investigated through a multivariate analysis. Subsequently, the role of Cyr61 on vascular remodeling was evaluated in vascular smooth muscle cells (VSMCs) upon oxidized low-density lipoprotein (ox-LDL) treatment by performing Cyr61 knockdown, Cell Counting Kit-8, flow cytometry and Transwell assays. Exosomal Cyr61 expression was found to be significantly elevated in patients with ACS compared with that in healthy individuals. In addition, exosomal Cyr61 levels were associated with sex, family history of ACS and glucose levels. ROC curve analyzes revealed that exosomal Cyr61 expression could be used to differentiate patients with UAP, AMI and ACS from healthy individuals. Furthermore, exosomal Cyr61 levels were independently correlated with the existence of ACS. In vitro, Cyr61 expression was demonstrated to be significantly increased in VSMCs after ox-LDL exposure in a concentration- and time-dependent manner. Functionally, the elevated cell viability and migration of VSMCs induced by ox-LDL were partially but significantly inhibited by Cyr61 knockdown. By contrast, knocking down Cyr61 expression significantly elevated the apoptosis rate of VSMCs compared with that in the ox-LDL-treated group. In conclusion, data from the present study suggest that Cyr61 serve a regulatory role in vascular remodeling in vitro, where exosomal Cyr61 levels may represent a promising biomarker for ACS diagnosis.

Exosomes and organ-specific metastasis

The transmission of information between tumor cells and other cell types in the tumor microenvironment plays an important role in tumor metastasis and is critically modulated by exosomes and other mediators. Tumor-derived exosomes can promote epithelial-mesenchymal transition, angiogenesis, immune escape, formation of the pre-metastatic microenvironment, and transmission of drug-resistant molecules, thereby promoting tumor growth, invasion, and metastasis. Integrins are important regulatory molecules on exosomes that can locate metastatic cells at the initial stage of metastasis and show good organotropism. This fact suggests that a clear understanding of the roles of exosomal integrins will be beneficial for future clinical applications. Follow-up studies on exosomes using continuously updated purification techniques and identification methods are extremely important. In addition to their potential as cancer biomarkers, exosomes also provide new research directions for precision medicine. Currently, exosomes have potential value in disease treatment and provide clinicians with more meaningful judgment standards.

Blood small extracellular vesicles derived miRNAs to differentiate pancreatic ductal adenocarcinoma from chronic pancreatitis

BACKGROUND

The differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis (CP) is clinically challenging due to a lack of minimally invasive diagnosis methods. MicroRNAs (miRNAs) derived from small extracellular vesicles (EVs) in the blood have been reported as a promising diagnosis biomarker for various types of cancer. However, blood small EV miRNA signatures and their diagnostic value to differentiate between PDAC and CP remain to be determined.

METHODS

In this study, 107 patients with PDAC or CP were recruited, and 90 patients were finally enrolled for a training cohort (n = 48) and test cohort (n = 42). Small RNA sequencing was used to assess the expression of blood small EV miRNAs in these patients.

RESULTS

The linear model from the differentially expressed blood small EV miR-95-3p divided by miR-26b-5p showed an average sensitivity of 84.1% and an average specificity of 96.6% to identify PDAC from CP in the training cohort and the test cohort, respectively. When the model was combined with serum carbohydrate antigen 19-9 (CA19-9), the average sensitivity increased to 96.5%, and the average specificity remained at 96.4% of both cohorts, which demonstrated the best performance of all the published biomarkers for distinguishing between PDAC and CP. The causal analysis performed using the Bayesian network demonstrated that miR-95-3p was associated with a "consequence" of "cancer" and miR-26b-5p as a "cause" of "pancreatitis." A subgroup analysis revealed that blood small EV miR-335-5p/miR-340-5p could predict metastases in both cohorts and was associated with an overall survival (p = 0.020).

CONCLUSIONS

This study indicated that blood small EV miR-95-3p/miR-26b-5p and its combination with serum levels of CA19-9 could separate PDAC from CP, and miR-335-5p/miR-340-5p was identified to associate with PDAC metastasis and poor prognosis. These results suggested the potentiality of blood small EV miRNAs as differential diagnosis and metastases biomarkers of PDAC.

Serum‑derived exosomes from house dust mite‑sensitized guinea pigs contribute to inflammation in BEAS‑2B cells via the TLR4‑NF‑κB pathway

Airway epithelial cells, which are the first physical defense barrier against allergens, play a pivotal role in immunity, airway inflammation and airway remodeling. The damage and dysfunction of these cells trigger the development of airway inflammatory diseases. Exosomes, which exist in various bodily fluids, mediate cell-cell communication and participate in the immune response process. The present study aimed to investigate whether serum exosomes play a pro-inflammatory role in bronchial epithelial cells (BEAS-2B cells) and, if so, explore the underlying molecular mechanisms. A guinea pig model of House dust mite (HDM)-induced asthma was established by sensitizing the rodents with HDM and PBS, and serum-derived exosomes were harvested. It was found that serum-derived exosomes from HDM-sensitized guinea pigs displayed higher levels of exosomal markers than those from controls. Additionally, western blot analysis and reverse transcription-quantitative PCR indicated that serum-derived exosomes from HDM-sensitized guinea pigs carried heat shock protein 70 and triggered an inflammatory response in BEAS-2B cells via the toll-like receptor 4 (TLR4)-NF-κB pathway. However, TAK-242, an inhibitor of the expression of TLR4, blocked the activation of the TLR4-NF-κB pathway. These findings provided a novel mechanism for exosome-mediated inflammatory responses and a new perspective for the intervention of inflammatory airway disorders.

Amplification-Free and Mix-and-Read Analysis of Multiplexed MicroRNAs on a Single Plasmonic Microbead

In this work, a single microbead covered with a plasmonic layer is employed as the microreactor for the multiplexed miRNA analysis without nucleic acid amplification. On the plasmonic layer, the S9.6 antibody is adopted as the universal module for binding DNA/miRNA duplexes regardless of the sequence. Meanwhile, there is also a SERS reporter gold nanoparticle (GNP) pool, in which each group of GNPs is labeled with both a Raman coding molecule and a DNA probe for recognizing a given miRNA of interest. The target miRNAs will lead to the specific capture of the corresponding SERS reporter GNPs onto the plasmonic layer, which will enormously enhance the target miRNA-induced SERS signals. Finally, the enhanced SERS signals concentrated on the microbead will be mapped out by a confocal Raman microscope. The proposed method achieves the high-precision sensing of sub-pM target miRNA in a simple mix-and-read format and possesses multiplexed assay capability.

Mesenchymal Stromal Cell-Derived Tailored Exosomes Treat Bacteria-Associated Diabetes Foot Ulcers: A Customized Approach From Bench to Bed

Exosomes are nano-vesicles of endosomal origin inherited with characteristics of drug delivery and cargo loading. Exosomes offer a diverse range of opportunities that can be exploited in the treatment of various diseases post-functionalization. This membrane engineering is recently being used in the management of bacteria-associated diabetic foot ulcers (DFUs). Diabetes mellitus (DM) is among the most crippling disease of society with a large share of its imposing economic burden. DM in a chronic state is associated with the development of micro- and macrovascular complications. DFU is among the diabetic microvascular complications with the consequent occurrence of diabetic peripheral neuropathy. Mesenchymal stromal cell (MSC)-derived exosomes post-tailoring hold promise to accelerate the diabetic wound repair in DFU associated with bacterial inhabitant. These exosomes promote the antibacterial properties with regenerative activity by loading bioactive molecules like growth factors, nucleic acids, and proteins, and non-bioactive substances like antibiotics. Functionalization of MSC-derived exosomes is mediated by various physical, chemical, and biological processes that effectively load the desired cargo into the exosomes for targeted delivery at specific bacterial DFUs and wound. The present study focused on the application of the cargo-loaded exosomes in the treatment of DFU and also emphasizes the different approaches for loading the desired cargo/drug inside exosomes. However, more studies and clinical trials are needed in the domain to explore this membrane engineering.

Exosomal transfer of miR-429 confers chemoresistance in epithelial ovarian cancer

The development of multidrug resistance during chemotherapy is the main obstacle for epithelial ovarian cancer (EOC) treatment. Exosomal transfer of carcinogenic microRNAs (miRNAs) might strengthen chemoresistance in recipient cells. Here, we identified through microarray analysis higher miR-429 expression in multidrug-resistant SKOV3 cells and their secreted exosomes (SKOV3-EXO) than in sensitive A2780 cells and their secreted exosomes. SKOV3-derived exosomes were internalized by A2780 cells, which permitted the transfer of miR-429. Exosomal miR-429 enhanced the proliferation and drug resistance of A2780 cells by targeting calcium-sensing receptor (CASR)/STAT3 pathway in vitro and in vivo. In addition, NF-κB-p65 was predicted to bind to the miR-429 promoter region, and the inhibition of NF-κB reduced the expression of miR-429 and led to the sensitivity of EOC cells. Consistently, A2780 cells co-incubated with SKOV3 pretreated with an NF-κB inhibitor or miR-429 antagomir showed sensitivity to cisplatin and exhibited attenuated cell proliferation. Based on our data, exosomal miR-429 functions as a primary regulator of the chemoresistance and malignant phenotypes of EOC by targeting CASR through a mechanism promoted by NF-κB and might be a therapeutic target for EOC.

Isolation of exosomes from serum of patients with lung cancer: a comparison of the ultra-high speed centrifugation and precipitation methods

Background

Extracellular vesicles (EVs) is a group of heterogeneous cell-derived membrane structures, which is composed of a large number of exosomes released by cells, microbubbles (MVs) and apoptotic bodies. The formation of exocrine body is a process of fine regulation, which includes four stages: initiation, endocytosis, polycystic body formation and exocrine body secretion. Ultracentrifugation is currently the gold standard for external body separation; it includes a series of centrifugation steps at a rotation speed of 100,000 rpm or more to purify exocrine bodies from protein contaminants. Thus far, some in vitro separation methods, such as ultracentrifugation, polymer-based exosome separation kits and immune affinity-based isolation using antibodies against exosome surface proteins, have been used for tumor exosome isolation. It is not very clear which method is more suitable for the separation of serum exosomes from lung cancer patients.

Methods

Two methods for the extraction of exosomes from serum samples of lung cancer patients, namely, ultra-high speed centrifugation (Ultra-Exo) and precipitation (Prekit-Exo), were analyzed and compared. The biological morphologies of the extracted exosomes were studied by negative staining matter with transmission electron microscopy and cryo-electron microscopy. The particle size and the distribution were detected using nanoparticle tracking analysis (NTA).

Results

Bio-transmission electron microscopy revealed that the morphologies of exosomes extracted by ultracentrifugation were superior to exosomes extracted with the Prekit-Exo kit. Ultracentrifugation was able to extract more exosomes compared to the Prekit-Exo kit. NTA showed that the exosomes obtained by ultra-high speed centrifugation had a smaller particle size compared to exosomes obtained by precipitation (30.4±26.8 vs. 150.3±6.8 nm, respectively). It is possible that the precipitant used in the precipitation kit was extracted with the exosomes, thereby causing the particle size to increase. Notably, the particle size of the exosomes extracted by the precipitation kit method showed a relatively narrow range in size. This could be due to the coating effect of the precipitation reagent, reducing the difference in the particle size of the exosomes.

Conclusions

Exosomes collected from the serum of lung cancer patients using the two extraction methods differed in morphology and numbers, with the ultracentrifugation method being superior to the precipitation method.

Co-continuous structural effect of size-controlled macro-porous glass membrane on extracellular vesicle collection for the analysis of miRNA

Recent studies have shown that extracellular vesicles (EVs) can be utilized as appropriate and highly specific biomarkers in liquid biopsy for the diagnosis and prognosis of serious illness. However, there are few methods that can collect and isolate miRNA in EVs simply, quickly and efficiently using general equipment such as a normal centrifuge. In this paper, we developed an advanced glass membrane column (AGC) device incorporating a size-controlled macro-porous glass (MPG) membrane with a co-continuous structure to overcome the limitations of conventional EV collection and miRNA extraction from the EVs. The size of macro-pores in the MPG membrane could be accurately controlled by changing the heating temperature and time on the basis of spinodal decomposition of B₂O₃, Na₂O, and SiO₂ in phase separation. The AGC device with an MPG membrane could collect the EVs simply and quickly (< 10 min) from cell culture supernatant, serum and urine. This AGC device could extract miRNA from the EVs captured in the MPG membrane with high efficiency when combined with a miRNA extraction solution. We suggest that the AGC device with an MPG membrane can be useful for the diagnosis and prognosis of serious illness using of EVs in various kinds of body fluids.

Urinary exosomal microRNA profiling in intermediate-risk prostate cancer

MicroRNAs (miRNAs) of urine exosomes have emerged as biomarkers for urological cancers, owing to their high stability. MiRNAs have been linked to factors associated with aggressive prostate cancer such as biochemical recurrence (BCR) and metastasis. In this study, we aimed to identify urinary exosomal miRNAs as prognostic markers associated with BCR in intermediate-risk prostate cancer. We profiled the expression levels of miRNAs via next generation sequencing in urinary exosomes from 21 non-BCR patients and 6 BCR patients of intermediate-risk prostate cancer. A total of 21 urinary exosomal miRNAs were found to be differentially expressed (> twofold) in BCR patients compared to non-BCR patients. For external validation, we validated these results using quantitative reverse transcription PCR in an independent cohort of 28 non-BCR patients and 26 BCR patients. A validation analysis revealed that three miRNAs (miR-26a-5p, miR-532-5p, and miR-99b-3p) were upregulated in exosomes from BCR patients. The univariate and multivariate Cox regression analyses showed that miR-532-5p was an important predictive factor for BCR of intermediate-risk prostate cancer. In conclusion, miR-532-5p in urine exosomes might be a potential biomarker for predicting BCR, which is a poor prognosis in patients with intermediate-risk prostate cancer. Further research is needed on the biological functions and mechanisms of this miRNA.

Advances in mesenchymal stem cell exosomes: a review

Stem cells can be used for regenerative medicine and as treatments for disease. The application of tissue engineering-related transplantation, stem cells, and local changes in the microenvironment is expected to solve major medical problems. Currently, most studies focus on tissue repair and regeneration, and mesenchymal stem cells (MSCs) are among the most common research topics. MSCs are applicable as seed cells, and they represent one of the current hot topics in regenerative medicine research. However, due to storage limitations and because cell senescence occurs during in vitro expansion, their clinical application is challenging. Exosomes, which are secreted by MSCs through paracrine signalling, not only have the same effects as MSCs, but they also have the advantages of targeted delivery, low immunogenicity, and high repairability. This article reviews the acquisition methods, characteristics, biological functions, and clinical applications of exosomes.

Mesenchymal Stem Cell-Derived Exosomes: Hope for Spinal Cord Injury Repair

Spinal cord injury (SCI) is a devastating medical condition with profound social and economic impacts. Although research is ongoing, current treatment options are limited and do little to restore functionality. However, recent studies suggest that mesenchymal stem cell-derived exosomes (MSC-exosomes) may hold the key to exciting new treatment options for SCI patients. MSCs are self-renewing multipotent stem cells with multi-directional differentiation and can secrete a large number of exosomes (vesicles secreted into the extracellular environment through endocytosis, called MSC-exosomes). These MSC-exosomes play a critical role in repairing SCI through promoting angiogenesis and axonal growth, regulating inflammation and the immune response, inhibiting apoptosis, and maintaining the integrity of the blood-spinal cord barrier. Furthermore, they can be utilized to transport genetic material or drugs to target cells, and their relatively small size makes them able to permeate the blood-brain barrier. In this review, we summarize recent advances in MSC-exosome themed SCI treatments and cell-free therapies to better understand this newly emerging methodology.

Bioinspired Extracellular Vesicles: Lessons Learned From Nature for Biomedicine and Bioengineering

Efficient communication is essential in all layers of the biological chain. Cells exchange information using a variety of signaling moieties, such as small molecules, proteins, and nucleic acids. Cells carefully package these messages into lipid complexes, collectively named extracellular vesicles (EVs). In this work, we discuss the nature of these cell carriers, categorize them by their origin, explore their role in the homeostasis of healthy tissues, and examine how they regulate the pathophysiology of several diseases. This review will also address the limitations of using EVs for clinical applications and discuss novel methods to engineer nanoparticles to mimic the structure, function, and features of EVs. Using lessons learned from nature and understanding how cells use EVs to communicate across distant sites, we can develop a better understanding of how to tailor the fundamental features of drug delivery carriers to encapsulate various cargos and target specific sites for biomedicine and bioengineering.

Extracellular microRNAs in human circulation are associated with miRISC complexes that are accessible to anti-AGO2 antibody and can bind target mimic oligonucleotides

MicroRNAs (miRNAs) function cell-intrinsically to regulate gene expression by base-pairing to complementary mRNA targets while in association with Argonaute, the effector protein of the miRNA-mediated silencing complex (miRISC). A relatively dilute population of miRNAs can be found extracellularly in body fluids such as human blood plasma and cerebrospinal fluid (CSF). The remarkable stability of circulating miRNAs in such harsh extracellular environments can be attributed to their association with protective macromolecular complexes, including extracellular vesicles (EVs), proteins such as Argonaut 2 (AGO2), or high-density lipoproteins. The precise origins and the potential biological significance of various forms of miRNA-containing extracellular complexes are poorly understood. It is also not known whether extracellular miRNAs in their native state may retain the capacity for miRISC-mediated target RNA binding. To explore the potential functionality of circulating extracellular miRNAs, we comprehensively investigated the association between circulating miRNAs and the miRISC Argonaute AGO2. Using AGO2 immunoprecipitation (IP) followed by small-RNA sequencing, we find that miRNAs in circulation are primarily associated with antibody-accessible miRISC/AGO2 complexes. Moreover, we show that circulating miRNAs can base-pair with a target mimic in a seed-based manner, and that the target-bound AGO2 can be recovered from blood plasma in an ∼1:1 ratio with the respective miRNA. Our findings suggest that miRNAs in circulation are largely contained in functional miRISC/AGO2 complexes under normal physiological conditions. However, we find that, in human CSF, the assortment of certain extracellular miRNAs into free miRISC/AGO2 complexes can be affected by pathological conditions such as amyotrophic lateral sclerosis.

Investigating potential molecular mechanisms of serum exosomal miRNAs in colorectal cancer based on bioinformatics analysis

Colorectal cancer (CRC) is the most common malignant gastrointestinal tumor worldwide. Serum exosomal microRNAs (miRNAs) play a critical role in tumor progression and metastasis. However, the underlying molecular mechanisms are poorly understood.The miRNAs expression profile (GSE39833) was downloaded from Gene Expression Omnibus (GEO) database. GEO2R was applied to screen the differentially expressed miRNAs (DEmiRNAs) between healthy and CRC serum exosome samples. The target genes of DEmiRNAs were predicted by starBase v3.0 online tool. The gene ontology (GO) and Kyoto Encyclopedia of Genomes pathway (KEGG) enrichment analysis were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. The protein-protein interaction (PPI) network was established by the Search Tool for the Retrieval of Interacting Genes (STRING) visualized using Cytoscape software. Molecular Complex Detection (MCODE) and cytohubba plug-in were used to screen hub genes and gene modules.In total, 102 DEmiRNAs were identified including 67 upregulated and 35 downregulated DEmiRNAs, and 1437 target genes were predicted. GO analysis showed target genes of upregulated DEmiRNAs were significantly enriched in transcription regulation, protein binding, and ubiquitin protein ligase activity. While the target genes of downregulated DEmiRNAs were mainly involved in transcription from RNA polymerase II promoter, SMAD binding, and DNA binding. The KEGG pathway enrichment analyses showed target genes of upregulated DEmiRNAs were significantly enriched in proteoglycans in cancer, microRNAs in cancer, and phosphatidylinositol-3 kinases/Akt (PI3K-Akt) signaling pathway, while target genes of downregulated DEmiRNAs were mainly enriched in transforming growth factor-beta (TGF-beta) signaling pathway and proteoglycans in cancer. The genes of the top 3 modules were mainly enriched in ubiquitin mediated proteolysis, spliceosome, and mRNA surveillance pathway. According to the cytohubba plugin, 37 hub genes were selected, and 4 hub genes including phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), SRC, cell division cycle 42 (CDC42), E1A binding protein p300 (EP300) were identified by combining 8 ranked methods of cytohubba.The study provides a comprehensive analysis of exosomal DEmiRNAs and target genes regulatory network in CRC, which can better understand the roles of exosomal miRNAs in the development of CRC. However, these findings require further experimental validation in future studies.

Application of exosomes as liquid biopsy in clinical diagnosis

Liquid biopsy refers to the sampling and molecular analysis of the biofluids of circulating tumor cells, extracellular vesicles, nucleic acids, and so forth. Exosomes are small extracellular vesicles with sizes between 30–150 nm. They are secreted by multivesicular bodies through exocytosis in live cells and can participate in intercellular communication due to their contents, including nucleic acids, proteins, and lipids. Herein, we investigate publication frequencies on exosomes over the past 10 years, and review recent clinical studies on liquid biopsy of exosomes in the fields of oncology, pregnancy disorders, cardiovascular diseases, and organ transplantation. We also describe the advantages of exosomes as an effective liquid biopsy tool and the progression of exosome extraction methods. Finally, we depict the commercial development of exosome research and discuss the future role of exosomes in liquid biopsy.

Ovatodiolide, isolated from Anisomeles indica, suppresses bladder carcinogenesis through suppression of mTOR/β-catenin/CDK6 and exosomal miR-21 derived from M2 tumor-associated macrophages

Bladder cancer (BCa) is the fourth leading cause of cancer deaths worldwide due to its aggressiveness and resistance against therapies. Intricate interactions between cancer cells and the tumor microenvironment (TME) are essential for both disease progression and regression. Thus, interrupting molecular communications within the TME could potentially provide improved therapeutic efficacies. M2-polarized tumor-associated macrophages (M2 TAMs) were shown to contribute to BCa progression and drug resistance. We attempted to provide evidence for ovatodiolide (OV) as a potential therapeutic agent that targets both TME and BCa cells. First, tumor-suppressing functions of OV were determined by cell viability, colony, and tumor-sphere formation assays using a coculture system composed of M2 TAMs/BCa cells. Subsequently, we demonstrated that extracellular vesicles (EVs) isolated from M2 TAMs containing oncomiR-21 and mRNAs, including Akt, STAT3, mTOR, and β-catenin, promoted cisplatin (CDDP) resistance, migration, and tumor-sphere generation in BCa cells, through increasing CDK6, mTOR, STAT3, and β-catenin expression. OV treatment also prevented M2 polarization and reduced EV cargos from M2 TAMs. Finally, in vivo data demonstrated that OV treatment overcame CDDP resistance. OV only and the OV + CDDP combination both resulted in significant reductions in mTOR, β-catenin, CDK6, and miR-21 expression in tumor samples and EVs isolated from serum. Collectively, we demonstrated that M2 TAMs induced malignant properties in BCa cells, in part via oncogenic EVs. OV treatment prevented M2 TAM polarization, reduced EV cargos derived from M2 TAMs, and suppressed β-catenin/mTOR/CDK6 signaling. These findings provide preclinical evidence for OV as a single or adjuvant agent for treating drug-resistant BCa.

THE PRESENT AND FUTURE OF THE MASS SPECTROMETRY-BASED INVESTIGATION OF THE EXOSOME LANDSCAPE

Exosomes are critical intercellular messengers released upon the fusion of multivesicular bodies with the cellular plasma membrane that deliver their cargo in the form of extracellular vesicles. Containing numerous nonrandomly packed functional proteins, lipids, and RNAs, exosomes are vital intercellular messengers that contribute to the physiologic processes of the healthy organism. During the post-genome era, exosome-oriented proteomics have garnered great interest. Since its establishment, mass spectrometry (MS) has been indispensable for the field of proteomics research and has advanced rapidly to interrogate biological samples at a higher resolution and sensitivity. Driven by new methodologies and more advanced instrumentation, MS-based approaches have revolutionized our understanding of protein biology. As the access to online proteomics database platforms has blossomed, experimental data processing occurs with more speed and accuracy. Here, we review recent advances in the technological progress of MS-based proteomics and several new detection strategies for MS-based proteomics research. We also summarize the use of integrated online databases for proteomics research in the era of big data. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.

The profiles of microRNAs from urinary extracellular vesicles (EVs) prepared by various isolation methods and their correlation with serum EV microRNAs

AIMS

MicroRNAs (miRNAs) that circulate in biological fluids are frequently enclosed in extracellular vesicles (EVs). However, urinary EVs and their cargo miRNAs have not been systematically studied according to their EV isolation methods.

METHODS

In type 2 diabetes mellitus persons with diabetic nephropathy (n = 4), we compared miRNA species in urine EVs prepared by ultracentrifugation (UC), qEV original size exclusion column (qEV), ExoQuick-TC Plus (ExoQuick), and ultrafiltration using Amicon Ultra centrifugal filter devices (Amicons) 10 K and 100 K. EV miRNAs were profiled by next-generation sequencing (NGS). Additionally, we evaluated the correlations of EV miRNA expression between the urine and serum samples isolated by UC.

RESULTS

From each of 100 ml of urine, the UC method yielded the highest number of EV miRNA species (233 ± 37.3), with the ExoQuick yielded the lowest (103 ± 17.4). Urine EV miRNA profiles were highly correlated between UC, qEV, ExoQuick and Amicon 10 K methods. EV miRNA profiles between the urine and serum samples showed variable correlations between the patients (paired sample number = 3, r = 0.39-0.72).

CONCLUSIONS

UC, qEV, ExoQuick, and Amicon 10 K are acceptable for urinary EV isolation to profile miRNAs. Urine- and serum-derived EV miRNA profiles have variable correlations depending on specific patients.

Applications of Mass Spectrometry for Clinical Diagnostics: The Influence of Turnaround Time

This critical review discusses how the need for reduced clinical turnaround times has influenced chemical instrumentation. We focus on the development of modern mass spectrometry (MS) and its application in clinical diagnosis. With increased functionality that takes advantage of novel front-end modifications and computational capabilities, MS can now be used for non-traditional clinical analyses, including applications in clinical microbiology for bacteria differentiation and in surgical operation rooms. We summarize here recent developments in the field that have enabled such capabilities, which include miniaturization for point-of-care testing, direct complex mixture analysis via ambient ionization, chemical imaging and profiling, and systems integration.

Circular RNA circ_0003204 inhibits proliferation, migration and tube formation of endothelial cell in atherosclerosis via miR-370-3p/TGFβR2/phosph-SMAD3 axis

BACKGROUND

Circular RNAs (circRNAs) represent a class of non-coding RNAs (ncRNAs) which are widely expressed in mammals and tissue-specific, of which some could act as critical regulators in the atherogenesis of cerebrovascular disease. However, the underlying mechanisms by which circRNA regulates the ectopic phenotype of endothelial cells (ECs) in atherosclerosis remain largely elusive.

METHODS

CCK-8, transwell, wound healing and Matrigel assays were used to assess cell viability, migration and tube formation. QRT-qPCR and Immunoblotting were used to examine targeted gene expression in different groups. The binding sites of miR-370-3p (miR-370) with TGFβR2 or hsa_circ_0003204 (circ_0003204) were predicted using a series of bioinformatic tools, and validated using dual luciferase assay and RNA immunoprecipitation (RIP) assay. The localization of circ_0003204 and miR-370 in ECs were investigated by fluorescence in situ hybridization (FISH). Gene function and pathways were enriched through Metascape and gene set enrichment analysis (GSEA). The association of circ_0003204 and miR-370 in extracellular vesicles (EVs) with clinical characteristics of patients were investigated using multiple statistical analysis.

RESULTS

Circ_0003204, mainly located in the cytoplasm of human aorta endothelial cells (HAECs), was upregulated in the ox-LDL-induced HAECs. Functionally, the ectopic expression of circ_0003204 inhibited proliferation, migration and tube formation of HAECs exposed to ox-LDL. Mechanically, circ_0003204 could promote protein expression of TGFβR2 and its downstream phosph-SMAD3 through sponging miR-370, and miR-370 targeted the 3' untranslated region (UTR) of TGFβR2. Furthermore, the expression of circ_0003204 in plasma EVs was upregulated in the patients with cerebral atherosclerosis, and represented a potential biomarker for diangnosis and prognosis of cerebrovascular atherogenesis.

CONCLUSIONS

Circ_0003204 could act as a novel stimulator for ectopic endothelial inactivation in atherosclerosis and a potential biomarker for cerebral atherosclerosis.

Recent advances and challenges in the recovery and purification of cellular exosomes

Exosomes are nanovesicles secreted by most cellular types that carry important biochemical compounds throughout the body with different purposes, playing a preponderant role in cellular communication. Because of their structure, physicochemical properties and stability, recent studies are focusing in their use as nanocarriers for different therapeutic compounds for the treatment of different diseases ranging from cancer to Parkinson's disease. However, current bioseparation protocols and methodologies are selected based on the final exosome application or intended use and present both advantages and disadvantages when compared among them. In this context, this review aims to present the most important technologies available for exosome isolation while discussing their advantages and disadvantages and the possibilities of being combined with other strategies. This is critical since the development of novel exosome-based therapeutic strategies will be constrained to the effectiveness and yield of the selected downstream purification methodologies for which a thorough understanding of the available technological resources is needed.

The release of tryptase from mast cells promote tumor cell metastasis via exosomes

Background

Cancer cells release exosomes and can be taken up by mast cells (MCs), but the potential functional effects of MCs on tumor metastasis remain unknown.

Method

Exosomes were isolated from the lung adenocarcinoma cell line A549, and the uptake of PKH26-labeled exosomes by bone marrow MCs was examined via flow cytometry and fluorescence microscopy. Cytokines and tryptase in MC supernatant were analyzed using an ELISA kit, and the presence of tryptase was evaluated by Western blotting. Cell proliferation and migration were determined through CCK-8 and transwell assays. Proteins in the tryptase-JAK-STAT signaling pathway were detected by Western blotting.

Results

In this study, we show that exosomes from A549 cells can be taken up by MCs. Moreover, A549 exosomes contain stem cell factor (SCF) to MCs and subsequently induce the activation of MCs through SCF-KIT signal transduction, which leads to MC degranulation and the release of tryptase. Tryptase accelerates the proliferation and migration of human umbilical vein endothelial cells (HUVECs) through the JAK-STAT signaling pathway.

Conclusions

Our results reveal a mechanism for metastasis in which exosomes can transfer SCF to and activate MCs, which can affect the release of tryptase and the angiogenesis of HUVECs.

Analysis of circulating non-coding RNAs in a non-invasive and cost-effective manner

Non-coding RNAs (ncRNAs) participate in regulation of gene expression, and are highly relevant to pathological development. They are found to be stably present in diverse body fluids, including those in the circulatory system, which can be sampled non-invasively for clinical tests. Thus, circulating ncRNAs have great potential to be disease biomarkers. However, tremendous efforts are desired to discover and utilize ncRNAs as biomarkers in clinical diagnosis, calling for technological advancement in analysis of circulating ncRNAs in biospecimens. Hence, this review summarizes the recent developments in this area, highlighting the works devoted to cancer diagnosis and prognosis. Three main directions are focused: 1) Extraction and purification of ncRNAs from body fluids; 2) Quantification of the purified circulating ncRNAs; and 3) Microfluidic platforms for integration of both steps to enable point-of-care diagnostics. These technologies have laid a solid foundation to move forward the applications of circulating ncRNAs in disease diagnosis and cure.

The exosome-mediated PI3k/Akt/mTOR signaling pathway in cervical cancer

BACKGROUND

Cervical cancer is the second most common cancer and one of the leading causes of cancer deaths among women worldwide.

OBJECTIVE

To evaluate the clinical significance of the PI3k/Akt/mTOR signaling pathway in cancer tissues and exosomes extracted from vaginal secretions.

METHODS

Immunohistochemical staining was used to detect the protein expression of PI3k, Akt, and mTOR in tissue samples from the control group, the CIN (cervical intraepithelial neoplasia) group, and the cervical cancer group. qPCR (quantitative PCR) was used to detect the expressions of PI3k, Akt, and mTOR in cervical cancer tissues, the corresponding adjacent tissues, and exosomes extracted from vaginal secretions.

RESULTS

Compared with those of healthy people and CIN, the PI3k/Akt/mTOR protein levels in extracts from tissues were higher in the cervical cancer patients. The PI3k/Akt/mTOR gene and protein levels increased in the cervical cancer tissues with the increase in the degree of malignancy of the cancer. There was no significant difference in PI3k/Akt/mTOR gene expression between the cervical cancer tissues and the exosomes extracted from vaginal secretions, but both were significantly higher than the expressions of the corresponding adjacent tissues.

CONCLUSIONS

The PI3k/Akt/mTOR signaling pathway mediated by exosomes extracted from vaginal secretions may provide candidate diagnostic biomarkers or potential therapeutic targets.

EV-associated miRNAs from peritoneal lavage as potential diagnostic biomarkers in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality worldwide. Current systematic methods for diagnosing have inherent limitations so development of a minimally-invasive diagnosis, based on the identification of sensitive biomarkers in liquid biopsies could therefore facilitate screening among population at risk.

METHODS

In this study, we aim to develop a novel approach to identify highly sensitive and specific biomarkers by investigating the use of extracellular vesicles (EVs) isolated from the peritoneal lavage as a source of potential miRNA diagnostic biomarkers. We isolated EVs by ultracentrifugation from 25 ascitic fluids and 25 peritoneal lavages from non-cancer and CRC patients, respectively. Analysis of the expression of EV-associated miRNAs was performed using Taqman OpenArray technology through which we could detect 371 miRNAs.

RESULTS

210 miRNAs were significantly dysregulated (adjusted p value < 0.05 and abs(logFC) ≥ 1). The top-10 miRNAs, which had the AUC value higher than 0.95, were miRNA-199b-5p, miRNA-150-5p, miRNA-29c-5p, miRNA-218-5p, miRNA-99a-3p, miRNA-383-5p, miRNA-199a-3p, miRNA-193a-5p, miRNA-10b-5p and miRNA-181c-5p.

CONCLUSIONS

This finding opens the avenue to the use of EV-associated miRNA of peritoneal lavages as an untapped source of biomarkers for CRC.

The research advances of exosomes in esophageal cancer

Esophageal carcinoma (EC) is one of the most common human digestive tract tumors, with high morbidity and mortality. It is necessary to elucidate the mechanism of cancer progression and seek early EC diagnostic markers for prompt detection and intervention. Exosomes are membrane nanovesicles secreted from many nucleated cells, 30-100 nm in diameter, containing various proteins, lipids and nucleic acids. They exist in peripheral blood, urine, ascites and other body fluids, widely engaged with intercellular material exchange and signal communication. Exosomes secreted from EC cells or tissues conduct important functions in tumor growth and progression. The detection and analysis of tumor-derived or tumor-associated exosomes has potential for EC early diagnosis and prognosis assessment. In the present paper, the exosomes' biological behaviors, isolation, detection and functions in EC progression - using as potential biomarkers for EC diagnosis or prognosis - are reviewed.