Nano-sized Extracellular Vesicles Research Articles

A Circulating Exosome RNA Signature Is a Potential Diagnostic Marker for Pancreatic Cancer, a Systematic Study.

Simple SummaryMost patients with pancreatic cancer are diagnosed at an advanced stage due to the lack of tools with high sensitivity and specificity for early detection. Aberrant gene expression occurs in pancreatic cancer, which can be packaged into nanoparticles (also known as exosomes or nano-sized extracellular vesicles) and then released into blood. In this study, we aimed to evaluate the diagnostic value of a circulating exosome RNA signature in pancreatic cancer. Our findings indicate that the circulating exosome RNA signature is a potential marker for the early detection or diagnosis of pancreatic cancer.Several exosome proteins, miRNAs and KRAS mutations have been investigated in the hope of carrying out the early detection of pancreatic cancer with high sensitivity and specificity, but they have proven to be insufficient. Exosome RNAs, however, have not been extensively evaluated in the diagnosis of pancreatic cancer. The purpose of this study was to investigate the potential of circulating exosome RNAs in pancreatic cancer detection. By retrieving RNA-seq data from publicly accessed databases, differential expression and random-effects meta-analyses were performed. The results showed that pancreatic cancer had a distinct circulating exosome RNA signature in healthy individuals, and that the top 10 candidate exosome RNAs could distinguish patients from healthy individuals with an area under the curve (AUC) of 1.0. Three (HIST2H2AA3, LUZP6 and HLA-DRA) of the 10 genes in exosomes had similar differential patterns to those in tumor tissues based on RNA-seq data. In the validation dataset, the levels of these three genes in exosomes displayed good performance in distinguishing cancer from both chronic pancreatitis (AUC = 0.815) and healthy controls (AUC = 0.8558), whereas a slight difference existed between chronic pancreatitis and healthy controls (AUC = 0.586). Of the three genes, the level of HIST2H2AA3 was positively associated with KRAS status. However, there was no significant difference in the levels of the three genes across the disease stages (stages I–IV). These findings indicate that circulating exosome RNAs have a potential early detection value in pancreatic cancer, and that a distinct exosome RNA signature exists in distinguishing pancreatic cancer from healthy individuals.

Changes in the Morphology, Number, and Protein Levels of Plasma Exosomes in CADASIL Patients.

Exosomes are nano-sized extracellular vesicles which are secreted by cells and usually found in body fluids. Previous research has shown that exosomal secretion and autophagy-lysosomal pathway synergistically participates in intracellular abnormal protein elimination. The main pathological manifestations of Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is abnormal accumulation of mutant NOTCH3, and CADASIL vascular smooth muscle cells have been found with autophagy-lysosomal dysfunction. However, whether plasma exosomes change in CADASIL patients is still unclear. We are aimed to investigate the differences of plasma exosomes between CADASIL patients and healthy controls. The subjects included 30 CADASIL patients and 30 healthy controls without NOTCH3 mutation. The severity of white matter lesions (WMLs) of CADASIL patients was quantified by Fazekas score. Transmission electron microscopy and nanoparticle tracking analysis were performed to characterize plasma exosomes. In addition, NOTCH3, Neurofilament light and Aβ42 levels in plasma exosomes were quantified by enzyme-linked immunosorbent assays. We found that exosomes from CADASIL patients were lower in quantity. In addition, CADASIL plasma exosomes had significantly lower levels of NOTCH3 and significantly increased levels of NFL than those of matched healthy subjects. Interestingly, plasma exosome NOTCH3 levels of CADASIL patients significantly correlated with severity of WMLs. The exosome NOTCH3 may be related to the pathological changes of CADASIL, which provides a basis for the pathogenesis research of CADASIL. In addition, plasma exosome NOTCH3 and NFL levels may act as biomarkers to monitor and predict disease progression and measure therapeutic effectiveness in the future clinical trials.

Therapeutic Influence of Exosomes Derived from Non-heat versus Heat Shocked Stem Cells on Experimentally Induced Myocardial Infarction in Adult Male Albino Rats

Background: Worldwide, myocardial infarction (MI) is considered as a principal cause of mortality. It results in death of the cardiac myocytes and declining of the cardiac functions. Exosomes of the bone marrow mesenchymal stem cells (BMMSCs) are cell-free, nano-sized extracellular vesicles that have the same reparative potentiality of the stem cells. Heat shock is one of the stresses that increase the production of heat shock proteins in the stem cells augmenting their survival capabilities. Aim of the Work: The current study aimed at assessing and comparing the therapeutic potentiality of exosomes derived from the non-heat and the heat shocked BMMSCs (non-HSBMMSCs-EXOs and HSBMMSCs-EXOs) on experimentally induced MI (acute & chronic stages) with underlining the probable explanation for that difference.Materials and Methods: 56 adult male albino rats were divided into the donor group (for non-HSBMMSCs-EXOs & HSBMMSCs-EXOs preparation) and the experimental groups (control, MI, MI-non-HSBMMSCs-EXOs & MI-HSBMMSCs-EXOs). Four control rats with two rats from each MI-non-HSBMMSCs-EXOs & MI-HSBMMSCs-EXOs groups were sacrificed 1 day following MI to confirm BMMSCs homing while other rats were sacrificed after 3 &28 days. Serological, biochemical, histological and morphometric studies were done.Results: The acute stage of MI revealed degenerative and inflammatory features whereas the chronic stage demonstrated marked fibrotic changes. Such changes were regressed in MI-non-HSBMMSCs-EXOs & MI-HSBMMSCs-EXOs groups except that of MI-non-HSBMMSCs-EXOs sacrificed after 28 days.Conclusion: Both non-HSBMMSCs-EXOs and HSBMMSCs-EXOs had therapeutic capabilities in the acute stage of MI which was more evident with HSBMMSCs-EXOs. In the chronic stage, non-HSBMMSCs-EXOs exhibited non-curative effect despite the perfect effect of HSBMMSCs-EXOs.

Mesenchymal Stem Cell-Derived Exosomes as New Remedy for the Treatment of Neurocognitive Disorders.

Mesenchymal stem cell (MSC)-derived exosomes (MSC-Exo) are nano-sized extracellular vesicles enriched with MSC-sourced neuroprotective and immunomodulatory microRNAs, neural growth factors, and anti-inflammatory cytokines, which attenuate neuro-inflammation, promote neo-vascularization, induce neurogenesis, and reduce apoptotic loss of neural cells. Accordingly, a large number of experimental studies demonstrated MSC-Exo-dependent improvement of cognitive impairment in experimental animals. In this review article, we summarized current knowledge about molecular and cellular mechanisms that were responsible for MSC-Exo-based restoration of cognitive function, emphasizing therapeutic potential of MSC-Exos in the treatment of neurocognitive disorders.

Towards Microfluidic-Based Exosome Isolation and Detection for Tumor Therapy.

Exosomes are a class of cell-secreted, nano-sized extracellular vesicles with a bilayer membrane structure of 30-150 nm in diameter. Their discovery and application have brought breakthroughs in numerous areas, such as liquid biopsies, cancer biology, drug delivery, immunotherapy, tissue repair, and cardiovascular diseases. Isolation of exosomes is the first step in exosome-related research and its applications. Standard benchtop exosome separation and sensing techniques are tedious and challenging, as they require large sample volumes, multi-step operations that are complex and time-consuming, requiring cumbersome and expensive instruments. In contrast, microfluidic platforms have the potential to overcome some of these limitations, owing to their high-precision processing, ability to handle liquids at a microscale, and integrability with various functional units, such as mixers, actuators, reactors, separators, and sensors. These platforms can optimize the detection process on a single device, representing a robust and versatile technique for exosome separation and sensing to attain high purity and high recovery rates with a short processing time. Herein, we overview microfluidic strategies for exosome isolation based on their hydrodynamic properties, size filtration, acoustic fields, immunoaffinity, and dielectrophoretic properties. We focus especially on advances in label-free isolation of exosomes with active biological properties and intact morphological structures. Further, we introduce microfluidic techniques for the detection of exosomal proteins and RNAs with high sensitivity, high specificity, and low detection limits. We summarize the biomedical applications of exosome-mediated therapeutic delivery targeting cancer cells. To highlight the advantages of microfluidic platforms, conventional techniques are included for comparison. Future challenges and prospects of microfluidics towards exosome isolation applications are also discussed. Although the use of exosomes in clinical applications still faces biological, technical, regulatory, and market challenges, in the foreseeable future, recent developments in microfluidic technologies are expected to pave the way for tailoring exosome-related applications in precision medicine.

Extracellular Vesicles for the Diagnosis and Treatment of Parkinson's Disease.

Extracellular vesicles (EVs) shed by neurons and glia in the central nervous system carry a cargo of specific bioactive molecules, facilitating intercellular communication. However, in neurodegenerative disease conditions, EVs carry pathological miRNAs and/or proteins involved in spreading the disease. Such EVs are also found in the cerebrospinal fluid (CSF) or the circulating blood, the characterization of which could identify biomarkers linked to specific neurodegenerative diseases. Moreover, EVs secreted by various stem/progenitor cells carry therapeutic miRNAs and proteins, which have shown promise to alleviate symptoms and slow down the progression of neurodegenerative diseases. The ability of exogenously administered EVs to easily cross the blood-brain barrier with no risk for thrombosis and incorporate into neurons and glia has also opened up the possibility of using nano-sized EVs as carriers of therapeutic drugs or bioactive proteins. This review summarizes the role and function of EVs in alpha-synuclein-mediated neurodegeneration and the spread of alpha-synuclein from neurons to glia, leading to the activation of the inflammatory response in Parkinson’s disease (PD). Moreover, the promise of brain-derived EVs in the CSF and the circulating blood for biomarker discovery and the efficacy of stem/progenitor cell-derived EVs or EVs loaded with bioactive molecules such as dopamine, catalase, curcumin, and siRNAs, in alleviating Parkinsonian symptoms are discussed.

Progenitor cell-derived exosomes endowed with VEGF plasmids enhance osteogenic induction and vascular remodeling in large segmental bone defects.

Large segmental bone regeneration remains a great challenge due to the lack of vascularization in newly formed bone. Conventional strategies primarily combine bone scaffolds with seed cells and growth factors to modulate osteogenesis and angiogenesis. Nevertheless, cell-based therapies have some intrinsic issues regarding immunogenicity, tumorigenesis, bioactivity and off-the-shelf transplantation. Exosomes are nano-sized (50-200 nm) extracellular vesicles with a complex composition of proteins, nucleic acids and lipids, which are attractive as therapeutic nanoparticles for disease treatment. Exosomes also have huge potential as desirable drug/gene delivery vectors in the field of regenerative medicine due to their excellent biocompatibility and efficient cellular internalization.Methods: We developed a cell-free tissue engineering system using functional exosomes in place of seed cells. Gene-activated engineered exosomes were constructed by using ATDC5-derived exosomes to encapsulate the VEGF gene. The specific exosomal anchor peptide CP05 acted as a flexible linker and effectively combined the engineered exosome nanoparticles with 3D-printed porous bone scaffolds.Results: Our findings demonstrated that engineered exosomes play dual roles as an osteogenic matrix to induce the osteogenic differentiation of mesenchymal stem cells and as a gene vector to controllably release the VEGF gene to remodel the vascular system. In vivo evaluation further verified that the engineered exosome-mediated bone scaffolds could effectively induce the bulk of vascularized bone regeneration.Conclusion: In our current work, we designed specifically engineered exosomes based on the requirements of vascularized bone repair in segmental bone defects. This work simultaneously illuminates the potential of functional exosomes in acellular tissue engineering.

Exosomes: New Advances in the Translational Potential of the “Garbage Bag”

Bidirectional cell-cell communication via paracrine mechanisms involving nano-sized extracellular vesicles have emerged as a predominant mechanism of cellular signaling. Unlike other shedding vesicles of similar size, exosomes selectively package their cargo using defined mechanisms within the cells. Recent research on exosome signaling describes a messenger-recipient cell dichotomy. The heterogeneous origin of exosome populations, although previously described, has as-yet been incompletely characterized using this dichotomy and thus does not currently provide a complete understanding of exosome populations. In this work, we outline the fundamentally bidirectional nature of exosomes and replace this dichotomy with a messenger-recipient-effector network formed by repackaging and rerelease events. This network further confounds the determination of messenger cell identity among an already heterogeneous exosome population and has major implications for future clinical application. Redefining the axiom of exosome signaling provides a route for future research to consider a multi-system-based approach and underscores a need for enhanced identification methods. This shift also has implications for the use of exosomes as therapeutic agents. Exosome biogenesis and its manipulation will be crucial for the development of curative endogenous exosomes and their synthetic, exogenously produced counterparts. Directed cargo loading, optimal shell composition, and robust production platforms are just some of the design aspects that need to be considered. As tissue-specific therapeutic agents, exosome design will also need to incorporate repackaging mechanics to prevent off-target effects and increase efficacy. A comprehensive current understanding of exosome biogenesis mechanisms amidst the heterogenous EV population will propel the field towards clinical viability.

Differentiation of Monocytes into Phenotypically Distinct Macrophages After Treatment with Human Cord Blood Stem Cell (CB-SC)-Derived Exosomes.

Stem Cell Educator (SCE) therapy is a novel clinical approach for the treatment of type 1 diabetes and other autoimmune diseases. SCE therapy circulates the isolated patient's blood mononuclear cells (e.g., lymphocytes and monocytes) through an apheresis machine, co-cultures the patient's blood mononuclear cells with adherent cord blood-derived stem cells (CB-SC) in the SCE device, and then returns these "educated" immune cells to the patient's blood. Exosomes are nano-sized extracellular vesicles between 30‒150 nm existing in all biofluid and cell culture media. To further explore molecular mechanisms underlying SCE therapy and determine the actions of exosomes released from CB-SC, we investigate which cells phagocytize these exosomes during the treatment with CB-SC. By co-culturing Dio-labeled CB-SC-derived exosomes with human peripheral blood mononuclear cells (PBMC), we found that CB-SC-derived exosomes were predominantly taken up by human CD14-positive monocytes, leading to the differentiation of monocytes into type 2 macrophages (M2), with spindle-like morphology and expression of M2-associated surface molecular markers. Here, we present a protocol for the isolation and characterization of CB-SC-derived exosomes and the protocol for the co-culture of CB-SC-derived exosomes with human monocytes and the monitoring of M2 differentiation.

Circulating exosomal microRNAs as emerging non‐invasive clinical biomarkers in heart failure: Mega bio‐roles of a nano bio‐particle

Exosomes are nano-sized extracellular vesicles containing a cell-specific biologically active cargo of proteins and genetic materials. Exosomes are constitutively released from almost all cell-types and affect neighboring or distant cells through a complex intercellular exchange of the genetic information and/or regulation of certain gene expressions that change the function and behavior of recipient cells. Those released into body fluids are the major mediators of intercellular communications. The success of the biological functions of exosomes is highly mediated by the effective transfer of microRNAs (miRs). Exosomes secreted by a damaged or diseased heart can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a "signature" or "fingerprint" of the donor cell. It has been shown that the transportation of cardiac-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in heart diseases. Currently, the search for new biomarkers of heart diseases remains a large and increasing enterprise. Notably, circulating exosomal miRs (Exo-miRs) have successfully gained huge interests for their diagnostic and prognostic potentials. The present review highlights circulating Exo-miRs explored for diagnosis/prognosis and outcome prediction in patients with heart failure (HF). To this end, we explain the feasibility of exosomes as clinical biomarkers, discuss the priority of circulating Exo-miRs over non-exosomal ones as a biomarker, and then outline reported circulating Exo-miRs having the biomarker function in HF patients, together with their mechanism of action. In conclusion, circulating Exo-miRs represent emerging diagnostic (Exo-miR-92b-5p, Exo-miR-146a, Exo-miR-181c, and Exo-miR-495) and prognostic (Exo-miR-192, Exo-miR-194, Exo-miR-34a, Exo-miR-425, Exo-miR-744) biomarkers for HF.

Pleiotropic Effects of Exosomes as a Therapy for Stroke Recovery.

Stroke is the leading cause of disability, and stroke survivors suffer from long-term sequelae even after receiving recombinant tissue plasminogen activator therapy and endovascular intracranial thrombectomy. Increasing evidence suggests that exosomes, nano-sized extracellular membrane vesicles, enhance neurogenesis, angiogenesis, and axonal outgrowth, all the while suppressing inflammatory reactions, thereby enhancing functional recovery after stroke. A systematic literature review to study the association of stroke recovery with exosome therapy was carried out, analyzing species, stroke model, source of exosomes, behavioral analyses, and outcome data, as well as molecular mechanisms. Thirteen studies were included in the present systematic review. In the majority of studies, exosomes derived from mesenchymal stromal cells or stem cells were administered intravenously within 24 h after transient middle cerebral artery occlusion, showing a significant improvement of neurological severity and motor functions. Specific microRNAs and molecules were identified by mechanistic investigations, and their amplification was shown to further enhance therapeutic effects, including neurogenesis, angiogenesis, axonal outgrowth, and synaptogenesis. Overall, this review addresses the current advances in exosome therapy for stroke recovery in preclinical studies, which can hopefully be preparatory steps for the future development of clinical trials involving stroke survivors to improve functional outcomes.

Exosome: A Review of Its Classification, Isolation Techniques, Storage, Diagnostic and Targeted Therapy Applications.

Exosomes are nano-sized small extracellular vesicles secreted by cells, carrying nucleic acids, proteins, lipids and other bioactive substances to play a role in the body’s physiological and pathological processes. Compared to synthetic carriers such as liposomes and nanoparticles, the endogeneity and heterogeneity of exosomes give them extensive and unique advantages in the field of disease diagnosis and treatment. However, the storage stability, low yield, low purity, and weak targeting of exosomes limit its clinical application. For this reason, further exploration is needed to optimize the above problems and facilitate future functional studies of exosomes. In this paper, the origin, classification, preparation and characterization, storage stability and applications of exosome delivery system are summarized and discussed by searching a large number of literatures.

Comparison of serum exosome isolation methods on co-precipitated free microRNAs.

BackgroundExosomes are nano-sized extracellular vesicles containing different biomolecules such as proteins and microRNAs (miRNAs) that mediate intercellular communication. Recently, numerous studies have reported the important functions of exosomal miRNAs in disease development and the potential clinical application as diagnostic biomarkers. Up to now, the most commonly used methods to extract exosomes are ultracentrifugation (UC) and precipitation-based commercial kit (e.g., ExoQuick). Generally, both UC and ExoQuick method could co-isolate contaminating proteins along with exosomes, with the UC method yielding even purer exosomes than ExoQuick. However, the comparison of these two methods on co-precipitated free miRNAs is still unknown.MethodsIn this study, we isolated exosomes from the human serum with exogenously added cel-miR-39 by UC and ExoQuick and compared the proportion of cel-miR-39 co-precipitated with exosomes extracted by these two methods.ResultsUsing exogenous cel-miR-39 as free miRNAs in serum, we concluded that ExoQuick co-isolates a small proportion of free miRNAs while UC hardly precipitates any free miRNAs. We also found that incubation at 37 °C for 1 h could decrease the proportion of free miRNAs, and exosomal miRNAs like miR-126 and miR-152 also decreased when RNase A was used. In conclusion, our findings provide essential information about the details of serum exosome isolation methods for further research on exosomal miRNAs.

Exosome-mediated delivery of miR-204-5p inhibits tumor growth and chemoresistance.

BackgroundNano‐sized extracellular vesicles secreted by cells play key roles in intercellular crosstalk, and appear to be an excellent biocompatible material as therapeutic cargoes in vivo. Previously, we have demonstrated that miR‐204‐5p is a key tumor suppressor that could inhibit tumor growth, metastasis and chemoresistance.MethodsA HEK293T cell line stably expressing miR‐204‐5p (293T‐miR‐204) was constructed by lentivirus transduction. Fluorescence real‐time quantitative PCR (qPCR) was applied to measure the expression of miR‐204‐5p. CCK‐8 and colony formation assays were used to evaluate the in vitro anticancer effects, and the flow cytometry was used to detect apoptosis. The in vivo therapeutic effects of exosomal miR‐204‐5p were evaluated using a xenograft mouse model. Western blots were used to detect the protein levels of CD63, Flotillin‐2, RAB22A and Bcl2. The protein levels of RAB22A and Bcl2 in tumor tissues were measured by immunohistochemistry staining.ResultsMiR‐204‐5p was clearly upregulated in CRC cells after coculturing with 293T‐miR‐204 cell‐derived conditioned medium (CM) or exosomes. CCK‐8 and colony formation assays showed that the cell proliferation ability of CRC cells was clearly inhibited by 293T‐miR‐204 cell‐derived CM or exosomes. The inhibitory effects of exosomal miR‐204‐5p on cell proliferation were further confirmed in other types of cancers. Exosomal miR‐204‐5p could induce apoptosis and increase the sensitivity of cancer cells to the chemotherapeutic drug—5‐fluorourcil. In addition, exosomal miR‐204‐5p inhibited the tumor growth in mice. Western blot assay and IHC staining showed that the protein levels of miR‐204‐5p targets were clearly decreased in cancer cells or xenograft tissues treated with exosomal miR‐204‐5p.ConclusionsIn this study, we confirmed that exosomal miR‐204‐5p could efficiently inhibit cancer cell proliferation, induce apoptosis and increase chemosensitivity by specifically suppressing the target genes of miR‐204‐5p in human cancer cells.

Exosomes in hypoxia-induced remodeling of the tumor microenvironment.

Exosomes are structurally and functionally pleiotropic nano-sized (~30-150nm in diameter) extracellular vesicles (EVs) with endosomal origin. These vesicles are secreted by almost all cells and play a significant role in intercellular communication and bio-waste disposal. To a great extent, exosomes represent biological "snapshot" of parent cells, and their cargos (protein, nucleotides, lipids, and metabolites) are loaded uniquely under different pathophysiological conditions. For example, most cancerous cells secrete a higher amount of exosomes loaded with distinct cargos under stressful low oxygen condition i.e. hypoxia, a key characteristic of solid tumors responsible for disease aggressiveness and poor survival. Exosomes secreted under hypoxia (ExoHypoxic) play a vital role in aiding cancer cells crosstalk with its microenvironment constituents to create conditions advantageous for cancer growth and metastatic spread. In this review article, we have highlighted the effects of ExoHypoxic on various tumor microenvironment components involved in angiogenesis, survival, proliferation, pre-metastatic niches preparation, immunomodulation, epithelial-to-mesenchymal transition, invasion, metastasis, and drug resistance. We have also described key ExoHypoxic cargos (miRNA, proteins, etc) and their targets in the receipt cells, responsible for various biological effects. Finally, we have emphasized the applicability of ExoHypoxic as a biomarker of tumor hypoxia and disease prognosis.

Therapeutic Use of Mesenchymal Stem Cell-Derived Exosomes: From Basic Science to Clinics.

Mesenchymal stem cells (MSC) are, due to their immunosuppressive and regenerative properties, used as new therapeutic agents in cell-based therapy of inflammatory and degenerative diseases. A large number of experimental and clinical studies revealed that most of MSC-mediated beneficial effects were attributed to the effects of MSC-sourced exosomes (MSC-Exos). MSC-Exos are nano-sized extracellular vesicles that contain MSC-derived bioactive molecules (messenger RNA (mRNA), microRNAs (miRNAs)), enzymes, cytokines, chemokines, and growth factors) that modulate phenotype, function and homing of immune cells, and regulate survival and proliferation of parenchymal cells. In this review article, we emphasized current knowledge about molecular and cellular mechanisms that were responsible for MSC-Exos-based beneficial effects in experimental models and clinical trials. Additionally, we elaborated on the challenges of conventional MSC-Exos administration and proposed the use of new bioengineering and cellular modification techniques which could enhance therapeutic effects of MSC-Exos in alleviation of inflammatory and degenerative diseases.

Toxicological evaluation of exosomes derived from human adipose tissue-derived mesenchymal stem/stromal cells

Several studies report that the therapeutic mechanism of action of mesenchymal stem/stromal cells (MSCs) is mainly mediated by paracrine factors that are released from MSCs such as exosomes. Exosomes are nano-sized extracellular vesicles that are transferred to target cells for cell-to-cell communication. Although MSC-derived exosomes (MSC-exosomes) are suggested as novel cell-free therapeutics for various human diseases, evaluation studies for the safety and toxicity of MSC-exosomes are limited. The purpose of our study was to evaluate the toxicological profile, including skin sensitization, photosensitization, eye and skin irritation, and acute oral toxicity using exosomes derived from human adipose tissue-derived MSCs (ASC-exosomes) in accordance with the OECD guidelines and the principles of Good Laboratory Practice. The ASC-exosomes were classified as a potential non-sensitizer in the skin sensitization test, UN GHS no category in the eye irritation test, and as a skin non-irritant in the skin irritation test, and did not induce any toxicity in the phototoxicity test or in acute oral toxicity testing. Our findings are the first to suggest that ASC-exosomes are safe for use as a topical treatment, with no adverse effects in toxicological testing, and have potential application as a therapeutic agent, cosmetic ingredient, or for other biological uses.

Oncogenic effects of RAB27B through exosome independent function in renal cell carcinoma including sunitinib-resistant.

Exosomes are 40–100 nm nano-sized extracellular vesicles. They are released from many cell types and move into the extracellular space, thereby transferring their components to recipient cells. Exosomes are receiving increasing attention as novel structures participating in intracellular communication. RAB27B is one of the leading proteins involved in exosome secretion, and oncogenic effects have been reported in several cancers. In recent years, molecularly targeted agents typified by sunitinib are widely used for the treatment of metastatic or recurrent renal cell carcinoma (RCC). However, intrinsic or acquired resistance to sunitinib has become a major issue. The present study aimed to elucidate the role of RAB27B in RCC including sunitinib-resistant and its role in exosomes. Bioinformatic analyses revealed that high expression of RAB27B correlates with progression of RCC. The expression of RAB27B protein in RCC cell lines was significantly enhanced compared with that in normal kidney cell lines. Furthermore, RAB27B protein expression was enhanced in all of the tested sunitinib-resistant RCC cell lines compared to parental cells. Although no specific effect of RAB27B on exosomes was identified in RCC cells, loss-of-function studies demonstrated that knockdown of RAB27B suppressed cell proliferation, migration and invasive activities. Moreover, anti-tumor effects of RAB27B downregulation were also observed in sunitinib-resistant RCC cells. RNA sequence and pathway analysis suggested that the oncogenic effects of RAB27B might be associated with MAPK and VEGF signaling pathways. These results showed that RAB27B is a prognostic marker and a novel therapeutic target in sunitinib-sensitive and -resistant RCCs. Further analyses should improve our understanding of sunitinib resistance in RCC.

A Pilot Study of Urinary Exosomes in Alzheimer’s Disease

Background: Exosomes are nano-sized extracellular vesicles secreted by most cell types and abundantly present in body fluids, including blood, saliva, urine, cerebrospinal fluid, and breast milk. Exosomes can spread toxic amyloid-beta (Aβ) and hyperphosphorylated tau between cells, contributing to neuronal loss in Alzheimer’s disease (AD). Objective: To explore changes in the morphology, number, and pathological protein levels of urinary exosomes in AD patients compared with age-matched healthy subjects. Methods: In this study, enzyme-linked immunosorbent assay was used to detect the levels of Aβ1–42 and P-S396-tau (normalized by CD63) in urinary exosomes of AD patients and matched healthy subjects. We used transmission electron microscopy and nanoparticle tracking analysis to observe the exosomes. Results: We found that the levels of Aβ1–42 and P-S396-tau in the urinary exosomes of AD patients were higher than those of matched healthy controls. Exosomes taken from AD patients were more numerous. Conclusion: The differences in levels of Aβ1–42 and P-S396-tau and the quantity of urinary exosomes between AD patients and healthy controls may provide a basis for early diagnosis of AD.

MP18-12 ONCOGENIC EFFECTS THROUGH EXOSOME INDEPENDENT FUNCTION OF RAB27B IN RENAL CELL CARCINOMA INCLUDING SUNITINIB-RESISTANT

INTRODUCTION AND OBJECTIVE:Exosomes are 40-100 nm nano-sized extracellular vesicles, released from many cell types and transfer their component to recipient cells. Recently exosomes have received i...