Function Of Exosomes Research Articles

Alterations in exosomal miRNA profile upon epithelial-mesenchymal transition in human lung cancer cell lines

BackgroundEpithelial–mesenchymal transition (EMT) is regarded as a critical event during tumor metastasis. Recent studies have revealed changes and the contributions of proteins in/on exosomes during EMT. Besides proteins, microRNA (miRNA) is another important functional component of exosomes. We hypothesized that the miRNA profile of exosomes may change following EMT and these exosomal miRNAs may in return promote EMT, migration and invasion of cancer cells.ResultsThe small RNA profile of exosomes was altered following EMT. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the specific miRNAs of M-exosomes have the potential to drive signal transduction networks in EMT and cancer progression. Co-culture experiments confirmed that M-exosomes can enter epithelial cells and promote migration, invasion and expression of mesenchymal markers in the recipient cells.ConclusionOur results reveal changes in the function and miRNA profile of exosomes upon EMT. M-exosomes can promote transfer of the malignant (mesenchymal) phenotype to epithelial recipient cells. Further, the miRNAs specifically expressed in M-exosomes are associated with EMT and metastasis, and may serve as new biomarkers for EMT-like processes in lung cancer.

Exosomes play roles in sequential processes of tumor metastasis.

Overwhelming evidence demonstrates that exosomes, a series of biologically functional small vesicles of endocytic origin carrying a variety of active constituents, especially tumor-derived exosomes, contribute to tumor progression and metastasis. This review focuses on the specific multifaceted roles of exosomes in affecting sequenced four crucial processes of metastasis, through which cancer cells spread from primary to secondary organs and finally form macroscopic metastatic lesions. First, exosomes modulate the primary tumor sites to assist cancer growth and dissemination. In this part, five main biological events are reviewed, including the transfer of oncogenic constituents, the recruitment and activation of fibroblasts, the induction of angiogenesis, immunosuppression and epithelial-mesenchymal transition (EMT) promotion. In Step 2, we list two recently disclosed mechanisms during the organ-specific homing process: the exosomal integrin model and exosomal epidermal growth factor receptor (EGFR)/miR-26/hepatocyte growth factor (HGF) model. Subsequently, Step 3 focuses on the interactions between exosomes and pre-metastatic niche, in which we highlight the specific functions of exosomes in angiogenesis, lymphangiogenesis, immune modulation and metabolic, epigenetic and stromal reprogramming of pre-metastatic niche. Finally, we summarize the mechanisms of exosomes in helping the metastatic circulating tumor cells escape from immunologic surveillance, survive in the blood circulation and proliferate in host organs.

Exogenous exosomes from mice with acetaminophen-induced liver injury promote toxicity in the recipient hepatocytes and mice

Exosomes are small extracellular membrane vesicles released from endosomes of various cells and could be found in most body fluids. The main functions of exosomes have been recognized as important mediators of intercellular communication and as potential biomarkers of various disease states. This study investigated whether exogenous exosomes from mice with acetaminophen (APAP)-induced liver injury can damage the recipient hepatic cells or promote hepatotoxicity in mice. We observed that exogenous exosomes derived from APAP-exposed mice were internalized into the primary mouse hepatocytes or HepG2 hepatoma cells and significantly decreased the viability of these recipient cells. They also elevated mRNA transcripts and proteins associated with the cell death signaling pathways in primary hepatocytes or HepG2 cells via exosomes-to-cell communications. In addition, confocal microscopy of ex vivo liver section showed that exogenously added exosomes were accumulated in recipient hepatocytes. Furthermore, plasma reactive oxygen species and hepatic TNF-α/IL-1β production were elevated in APAP-exosomes recipient mice compared to control-exosomes recipient mice. The levels of apoptosis-related proteins such as phospho-JNK/JNK, Bax, and cleaved caspase-3 were increased in mouse liver received APAP-exosomes. These results demonstrate that exogenous exosomes from APAP-exposed mice with acute liver injury are functional and stimulate cell death or toxicity of the recipient hepatocytes and mice.

Exosome and Macrophage Crosstalk in Sleep-Disordered Breathing-Induced Metabolic Dysfunction.

Obstructive sleep apnea (OSA) is a highly prevalent worldwide public health problem that is characterized by repetitive upper airway collapse leading to intermittent hypoxia, pronounced negative intrathoracic pressures, and recurrent arousals resulting in sleep fragmentation. Obesity is a major risk factor of OSA and both of these two closely intertwined conditions result in increased sympathetic activity, oxidative stress, and chronic low-grade inflammation, which ultimately contribute, among other morbidities, to metabolic dysfunction, as reflected by visceral white adipose tissue (VWAT) insulin resistance (IR). Circulating extracellular vesicles (EVs), including exosomes, are released by most cell types and their cargos vary greatly and reflect underlying changes in cellular homeostasis. Thus, exosomes can provide insights into how cells and systems cope with physiological perturbations by virtue of the identity and abundance of miRNAs, mRNAs, proteins, and lipids that are packaged in the EVs cargo, and are secreted from the cells into bodily fluids under normal as well as diseased states. Accordingly, exosomes represent a novel pathway via which a cohort of biomolecules can travel long distances and result in the modulation of gene expression in selected and targeted recipient cells. For example, exosomes secreted from macrophages play a critical role in innate immunity and also initiate the adaptive immune response within specific metabolic tissues such as VWAT. Under normal conditions, phagocyte-derived exosomes represent a large portion of circulating EVs in blood, and carry a protective signature against IR that is altered when secreting cells are exposed to altered physiological conditions such as those elicited by OSA, leading to emergence of IR within VWAT compartment. Consequently, increased understanding of exosome biogenesis and biology should lead to development of new diagnostic biomarker assays and personalized therapeutic approaches. Here, the evidence on the major biological functions of macrophages and exosomes as pathophysiological effectors of OSA-induced metabolic dysfunction is discussed.

Immunomodulation by Exosomes in Myocardial Infarction.

Exosomes are important carriers of biological information that facilitate intercellular communication and participate in the pathophysiology of different cardiovascular diseases. Myocardial infarction is among the leading causes of death worldwide. Upon myocardial infarction, massive cardiomyocyte death triggers a strong inflammatory response which is a vital process of cardiac injury, repair, and remodeling. Increasing evidence has unveiled that exosomes are involved in the inflammatory response and immune regulation after myocardial infarction. In this review, we will summarize the biological function of exosomes in the pathophysiology of myocardial infarction, especially focusing on their roles in the modulation of inflammation and immune response after myocardial infarction which further influences myocardial repair and remodeling. We will also discuss the immunomodulation by exosomes derived from stem and progenitor cells in the treatment of myocardial infarction. A deep understanding of immunomodulation by exosomes may represent a promising therapeutic option for the treatment of myocardial infarction.

The critical role of exosomes in tumor biology.

Exosomes are a typeof extracellular vesicles (diameter, 30-160 nm),which containmultiple proteins, nucleic acids, lipid molecules, and other substances. Most types of cells can secrete exosomes, although the biogenesis, composition, and function is specific to different cell types. Recently, manystudies have demonstrated that exosomes play a critical role in tumor development. In this review, we briefly summarize the biogenesis, composition, and function of exosomes. We also discuss the recent advances in the critical role of exosomes in tumor biologywith a special focus on their application in tumor diagnosis and treatment.

Exosomes in perspective: a potential surrogate for stem cell therapy.

Exosomes as a unique subtype of small extracellular vesicles (sEVs) have attracted increasing interest in recent years in the fields of mesenchymal stromal cell (MSC) research. Studies have confirmed that exosomes derived from MSCs preserve immunosuppressive phenotype and can mimic therapeutic benefits of their parent cells. This review briefly summarizes most recent findings on the potential of exosomes as an alternative of therapeutic MSCs, focusing on the role of MSCs and their secreted exosomes in regulation of immune cells, preclinical and clinical evidence of therapeutic outcomes of MSC exosomes, and the biodistribution and pharmacokinetic profile of systemically administered exosomes. It is appreciated that exosomes from MSCs of different sources have variable contents including inflammatory mediators, tropic factors, signaling molecules, and nucleic acids (DNA, mRNA, microRNA and long non-coding RNA). Diverse functions of exosomes derived from different sources are expected. More importantly, exosomes isolated in vitro may not mirror that from in vivo, where donor MSCs are exposed to specific disease or injury-related conditions. Simulating in vivo microenvironment by pretreatment of MSCs with relevant chemical mediators may lead to their secretion of therapeutically more efficient exosomes/sEVs. However, we know very little about the key molecules involved and the differences between exosomes released under different conditions. These issues would be of tremendous interest to preclinical research that pursues exosome biology-underlain therapeutic mechanisms of MSCs. Further studies are expected to demonstrate the superiority of MSC-derived exsomes/sEVs as a pharmaceutical entity with regard to efficacy, safety, and practicability.

Host derived exosomes-pathogens interactions: Potential functions of exosomes in pathogen infection.

As bilayer vesicular corpuscles secreted by different living cells, exosomes can be found in diverse body fluids and are rich in lipids, proteins, nucleic acids and other complicated components. Exosomes offer a potent mechanism for participation in intercellular transportation, such as targeted transmission of inclusions to nearby or distant cells or tissues, and assistance in intercellular information communication to change physiological functions and properties. Exosomes take part in antigen presentation for activation of immune cells and stimulate the release of inflammatory factors and the expression of immune molecules, thus modulating the immune responses of host cells. In the microbial infection of host cells, exosomes can strengthen innate and specific immune responses and thereby the immune resistance against the invading microbes through natural killer cells, macrophages and activated T cells by the presentation of pathogens including viral factors and bacteria, but exosomes are also capable of immunosuppression during pathogens infection. Exosomes are considerably valuable in research and clinical defense of microbial infection, given their biological activities in intercellular transportation, information communication and cell-mediated immunity modulation after microbial infection.

Tumor-derived exosomes induce N2 polarization of neutrophils to promote gastric cancer cell migration

BackgroundExosomes are extracellular vesicles that mediate cellular communication in health and diseases. Neutrophils could be polarized to a pro-tumor phenotype by tumor. The function of tumor-derived exosomes in neutrophil regulation remains unclear.MethodsWe investigated the effects of gastric cancer cell-derived exosomes (GC-Ex) on the pro-tumor activation of neutrophils and elucidated the underlying mechanisms.ResultsGC-Ex prolonged neutrophil survival and induced expression of inflammatory factors in neutrophils. GC-Ex-activated neutrophils, in turn, promoted gastric cancer cell migration. GC-Ex transported high mobility group box-1 (HMGB1) that activated NF-κB pathway through interaction with TLR4, resulting in an increased autophagic response in neutrophils. Blocking HMGB1/TLR4 interaction, NF-κB pathway, and autophagy reversed GC-Ex-induced neutrophil activation. Silencing HMGB1 in gastric cancer cells confirmed HMGB1 as a key factor for GC-Ex-mediated neutrophil activation. Furthermore, HMGB1 expression was upregulated in gastric cancer tissues. Increased HMGB1 expression was associated with poor prognosis in patients with gastric cancer. Finally, gastric cancer tissue-derived exosomes acted similarly as exosomes derived from gastric cancer cell lines in neutrophil activation.ConclusionWe demonstrate that gastric cancer cell-derived exosomes induce autophagy and pro-tumor activation of neutrophils via HMGB1/TLR4/NF-κB signaling, which provides new insights into mechanisms for neutrophil regulation in cancer and sheds lights on the multifaceted role of exosomes in reshaping tumor microenvironment.

Exosomes from human placenta purified by affinity chromatography on sepharose bearing immobilized antibodies against CD81 tetraspanin contain many peptides and small proteins.

Exosomes are nanovesicles (40-100 nm) containing various RNAs and different proteins. Exosomes are involved in intracellular communication and immune system function. Exosomes from different sources are usually isolated using standard methods-centrifugation and ultracentrifugations. Exosomes isolated by these procedures were reported to contain from a few dozen to thousands of different proteins. Here crude vesicle preparations from five placentas (normal pregnancy) were first obtained using standard centrifugation procedures. According to electron-microscopic studies, these preparations contained vesicles of different size (30-225 nm), particles of round shape of average electron density ("nonvesicles" 20-40 nm) (A), structured clusters of associated proteins and shapeless aggregations (B), as well as ring-shaped 10-14 nm structures formed by ferritin (C). After additional purification of the vesicle preparations by gel filtration on Sepharose 4B, the main part of protein structures was removed; however, the preparations still contained small admixtures of components A-C. Further purification of the preparations by affinity chromatography on Sepharose bearing immobilized antibodies against exosome surface protein CD81 led to isolation of highly purified exosomes (40-100 nm). These exosomes according to electron microscopy data contained tetraspanin embedded in the membrane, which was stained with antibodies against CD81 conjugated with 10-12 nm gold nanoparticles. SDS-PAGE and MALDI MS and MS/MS mass spectrometry of tryptic hydrolysates of proteins contained in these exosomes revealed eleven major proteins (>10 kDa): hemoglobin subunits, CD81, interleukin-1 receptor, annexin A5, cytoplasmic actin, alpha-actin-4, alkaline phosphatase, human serum albumin, serotransferrin, and lactotrasferrin. Using MALDI mass analysis of the highly purified exosomes, we for the first time found that in addition to the large proteins (>10 kDa), exosomes having affinity to CD81 contain more than 27 different peptides and small proteins of 2-10 kDa. This finding can be useful for revealing biological functions of pure exosomes. © 2018 IUBMB Life, 70(11):1144-1155, 2018.

A two-way road: novel roles for fungal extracellular vesicles.

The biological functions of fungal extracellular vesicles (EVs) or exosomes have been mostly determined on the basis of the assumption that they are vehicles of trans-cell wall transport and molecular export. The possibility that fungal cells can bind to and internalize EVs remained largely unaddressed. Recent studies, however, demonstrated that fungal cells can internalize host-derived and/or fungal EVs through processes that profoundly modify their regular physiology. To illustrate this novel view, we discuss (i) the uptake of plant EVs by phytopathogenic fungi culminating in growth defects and virulence attenuation, (ii) the influence of EV internalization in prion transmission and biofilm formation in yeast cells, and (iii) the EV-mediated transfer of virulence in isolates of Cryptococcus gattii. These recent observations indicate that the functions exerted by EVs in fungal cells result from previously unknown mechanisms of bidirectional transport, opening new venues for the investigation of how EVs impact fungal physiology.

The Exosome: a New Player in Diabetic Cardiomyopathy.

Diabetic cardiomyopathy (DCM) or diabetes-induced cardiac dysfunction is a direct consequence of uncontrolled metabolic syndrome and occurs worldwide. However, the underlying cellular and molecular mechanisms remain poorly understood. Recently, exosomes have attracted considerable interest for their use as efficient, targeted, and non-immunogenic delivery systems for biological molecules or pharmacotherapies. This review will summarize the fast-developing field of the regulation and function of exosomes in DCM, affording valuable insights and therapeutic opportunities in combatting diabetes-related cardiac disorder for modern human health.

Sinomenine Protects Against Morphine Dependence through the NMDAR1/CAMKII/CREB Pathway: A Possible Role of Astrocyte-Derived Exosomes.

Sinomenine is a nonaddictive alkaloid used to prevent morphine dependence, even thoughits mechanism isnot fully understood. Astrocytes aggravate the pathological process in their neighboring cellsthrough exosomes in central nervous system diseases. However, the effect of sinomenine on astrocyte-derived exosomes for the amelioration of morphine dependence has not been reported yet. In this study, we found that sinomenine prevented the morphine-induced conditionedplace preference in mice. Sinomenine reduced the levels of cAMP and intracellular Ca2+ in morphine-treated SH-SY5Y cells. Moreover, sinomenine inhibited the expressions of p-NMDAR1/NMDAR1, p-CAMKII/CAMKII, and p-CREB/CREB in the hippocampusof morphine-dependent mice and SH-SY5Y cells. Furthermore, we found that sinomenine inhibitedthe morphine-induced activation of astrocytesin vivo and in vitro. Afterwards, exosomes were isolated from cultured primary astrocytes treated with phosphate buffer saline (PBS, ctl-exo), morphine (mor-exo), or morphine and sinomenine (Sino-exo). Subsequently, morphine-treated SH-SY5Y cells were treated with ctl-exo, mor-exo, and Sino-exo. Results showed that Sino-exo reduced the level of cAMP, intracellular Ca2+, and the expression of p-CAMKII/CAMKII and p-CREB/CREB in morphine-treated SH-SY5Y cells. In conclusion, we demonstrated that sinomenine exhibited protective effects against morphine dependencein vivo and in vitro through theNMDAR1/CAMKII/CREB pathway. Sinomenine-induced alterationof the function of astrocyte-derived exosomes may contribute to the antidependence effects of sinomenine in morphine dependence.

Loss of exosomal miR-148b from cancer-associated fibroblasts promotes endometrial cancer cell invasion and cancer metastasis.

Cancer-associated fibroblasts (CAFs) play crucial roles in tumor progression, given the dependence of cancer cells on stromal support. Therefore, understanding how CAFs communicate with endometrial cancer cell in tumor environment is important for endometrial cancer therapy. Exosomes, which contain proteins and noncoding RNA, are identified as an important mediator of cell-cell communication. However, the function of exosomes in endometrial cancer metastasis remains poorly understood. In the current study we found that CAF-derived exosomes significantly promoted endometrial cancer cell invasion comparing to those from normal fibroblasts (NFs). We identified a significant decrease of miR-148b in CAFs and CAFs-derived exosomes. By exogenously transfect microRNAs, we demonstrated that miR-148b could be transferred from CAFs to endometrial cancer cell through exosomes. In vitro and in vivo studies further revealed that miR-148b functioned as a tumor suppressor by directly binding to its downstream target gene, DNMT1 to suppress endometrial cancer metastasis. In endometrial cancer DNMT1 presented a potential role in enhancing cancer cell metastasis by inducing epithelial-mesenchymal transition (EMT). Therefore, downregulated miR-148b induced EMT of endometrial cancer cell as a result of relieving the suppression of DNMT1. Taken together, these results suggest that CAFs-mediated endometrial cancer progression is partially related to the loss of miR-148b in the exosomes of CAFs and promoting the transfer of stromal cell-derived miR-148b might be a potential treatment to prevent endometrial cancer progression.

Enhanced Therapeutic Effects of Mesenchymal Stem Cell-Derived Exosomes with an Injectable Hydrogel for Hindlimb Ischemia Treatment.

Mesenchymal stem cell (MSC)-derived exosomes have been recognized as new candidates for cell-free treatment of various diseases. However, maintaining the retention and stability of exosomes over time in vivo after transplantation is a major challenge in the clinical application of MSC-derived exosomes. Here, we investigated if human placenta-derived MSC-derived exosomes incorporated with chitosan hydrogel could boost the retention and stability of exosomes and further enhance their therapeutic effects. Our results demonstrated that chitosan hydrogel notably increased the stability of proteins and microRNAs in exosomes, as well as augmented the retention of exosomes in vivo as confirmed by Gaussia luciferase imaging. In addition, we assessed endothelium-protective and proangiogenesis abilities of hydrogel-incorporated exosomes in vitro. Meanwhile, we evaluated the therapeutic function of hydrogel-incorporated exosomes in a murine model of hindlimb ischemia. Our data demonstrated that chitosan hydrogel could enhance the retention and stability of exosomes and further augment the therapeutic effects for hindlimb ischemia as revealed by firefly luciferase imaging of angiogenesis. The strategy used in this study may facilitate the development of easy and effective approaches for assessing and enhancing the therapeutic effects of stem cell-derived exosomes.

Abstract 333: TNF Receptor Modulation of Progenitor Cells and Exosomes for Myocardial Repair

Our published studies, using TNFR1 and TNFR2 knockout (KO) mice have demonstrated that negative effects of TNF during ischemic tissue repair including enhanced apoptosis and inflammatory cytokines expression and signaling, is largely mediated by TNFR1/p55. Our hypothesis is that inhibition of TNF-TNFR1 signaling inhibits multiple negative effects of TNF after myocardial ischemia by promoting TNF signaling through protective TNFR2 receptor and thereby augmenting EPC-mediated myocardial angiogenesis and repair and this enhanced protective effect of TNFR1 KO EPCs may involve alteration in the cargo and function of TNFR1-KO EPC derived exosomes. Protective effect of disrupted TNF-TNFR1/p55 signaling in BM-EPCs under stress conditions in WT, p55KO and p75KO EPCs were tested in tube formation assay under hypoxia conditions and H2O2 treatment. In the absence of TNFR1 (p55KO EPCs) - EC function of BM-EPCs is enhanced under normoxia/hypoxia conditions and survival of BM-EPCs is increased under oxidative stress. To test the effect of TNFR1 and TNFR2 loss in the BM-EPCs for recovery after AMI, WT mice were subjected to AMI and WT, p75KO and p55KO BM-EPCs were injected into the myocardium immediately after AMI. Compared to WT and p75KO, injection of p55KO EPCs into WT hosts led to - increased retention of p55KO EPCs in the WT mice hearts; decreased post-MI apoptosis in WT mice; increased vascular network; significantly improved cardiac function; substantially small infarct size; the last three indicating improved cardiac remodeling by day 21 post-AMI. Further, in vitro exosome studies showed that compared to WT and p75KOs, p55KO BM-EPCs-derived exosomes showed positive activities in vitro, including - enhanced angiogenic function in HUVECs and increased survival of H9C2 cells. These effects were mediated via upregulation of miRNA-191-5p as shown by increased levels of angiogenic miR-191-5p in the exosomal cargo of p55KO EPCs and near complete inhibition of HUVEC angiogenic function in vitro by miR-191-5p-antagomiR. Our findings suggest that decrease/loss of TNFR1 modulates both the content and function of EPC exosomes and enhance reparative and angiogenic capabilities of EPCs and EPC-mediated vascular and anatomical repair in the MI model.

Sphk2 RNAi nanoparticles suppress tumor growth via downregulating cancer cell derived exosomal microRNA

Exosomes secreted from cancer cells promote tumor progression through the transfection of containing microRNA (miRNA), mRNAs and proteins. Yet, little of this knowledge has translated into the therapeutic application. Herein, we propose a tumor therapeutic strategy via decreasing exosomal miRNA secretion. The study designed small interfering RNA (siRNA) loaded nanoparticles to downregulate sphingosine kinase 2 (Sphk2) and investigate their potential in decreasing exosomal oncogenic miRNA content and inhibiting tumor growth. The synthesized lipid (2E)-4-(dioleostearin)-amino-4‑carbonyl-2-butenoic (DC) and chitosan were utilized to produce siRNA loaded nanoparticles (DC/CS-siRNA NPs), with optimal siRNA complexation and high transfection efficacy. We demonstrated that Sphk2 gene silencing induced by nanoparticles in hepatocellular carcinoma (HCC) cells could reduce miRNA-21 sorting into exosomes, contributing to the inhibition of tumor cell migration and tumorigenic function of exosomes to normal liver cells. Furthermore, in xenograft mouse model, Sphk2 siRNA loaded DC/CS NPs could significantly block tumor progression of malignancy HCC. These results suggest a new therapeutic approach for tumor treatment by ablating oncogenic miRNA in malicious exosomes.

Extracellular vesicles: lipids as key components of their biogenesis and functions

Intercellular communication has been known for decades to involve either direct contact between cells or to operate via circulating molecules, such as cytokines, growth factors, or lipid mediators. During the last decade, we have begun to appreciate the increasing importance of intercellular communication mediated by extracellular vesicles released by viable cells either from plasma membrane shedding (microvesicles, also named microparticles) or from an intracellular compartment (exosomes). Exosomes and microvesicles circulate in all biological fluids and can trigger biological responses at a distance. Their effects include a large variety of biological processes, such as immune surveillance, modification of tumor microenvironment, or regulation of inflammation. Extracellular vesicles can carry a large array of active molecules, including lipid mediators, such as eicosanoids, proteins, and nucleic acids, able to modify the phenotype of receiving cells. This review will highlight the role of the various lipidic pathways involved in the biogenesis and functions of microvesicles and exosomes.

Injury Factors Alter miRNAs Profiles of Exosomes Derived from Islets and Circulation

Islets damage is a major abnormality underling diabetes, thus timely monitoring islets destruction is critically needed. Recent studies discovered the biological functions of exosomes and suggested the value of exosomes in disease diagnosis and prognosis. This study aimed to investigate the impact of injury factors on the miRNA profiles of islet exosomes and determine whether circulating exosomal miRNAs would be suitable as biomarkers of islets cell damage. Islets were isolated from ICR mice and induced injury in vitro by mixed cytokines (TNFα, IL-1β and IFNγ) and streptozotocin (STZ) and exosomes were derived from the cultural supernatant. Using miRNA microarray analysis, we found 22 and 11 differentially expressed miRNAs in islet exosomes of STZ and cytokines treatment, respectively. 6 differentially expressed exosaml miRNAs were found both in STZ and cytokines treated group, and miR-375-3p and miR-129-5p were validated by quantitative RT-PCR. Serum exosomes were isolated from ICR mice of islets damage in vivo induced by STZ injection and subjects with various glucose metabolism states and diabetic duration. Quantitative RT-PCR demonstrated exosomal miR-375-3p dramatically increased in serum of STZ treated mouse prior to the turbulence of blood glucose and serum insulin. In human serum exosomes, miR-375-3p was elevated in newly new-onset diabetes patients. Overall, our results suggest that injury factors cytokines and STZ affected the miRNA profiles of exosomes derived from islets and exosomal miR-375-3p showed promising potential as a biomarker of islets damage. Further studies were necessary to purify islet-specific exosomes from circulation for improving the accuracy. Disclosure Q. Fu: None. H. Jiang: None. T. Yang: None.

Proteomics study of serum exosomes from papillary thyroid cancer patients.

Lymph node metastasis (LNM) in papillary thyroid cancer (PTC) is related to increased risk of recurrence and poor prognosis. Tumour exosomes have been shown to be associated with metastasis of cancer cells. Therefore, we aim to identify the characteristics and biological functions of serum exosomes in lymph node metastases of PTC. We compared proteome profiles of serum-purified exosomes (SPEs) from PTC patients with LNM, PTC patients without LNM, and healthy donors, using a combination of liquid chromatography-tandem mass spectroscopy analyses and tandem mass tag label quantitation analysis. We identified 1569 proteins by two or more unique peptides. Compared with the SPEs of PTC patients without LNM, we found 697 differentially expressed proteins in the SPEs of PTC patients with LNM. Our results revealed overexpression of specific proteins with well-established links to cancer cell metastasis, such as SRC, TLN1, ITGB2 and CAPNS1. Consistent with mass spectrum results, we performed Western blot to detect the expression of these proteins in individual sample. Biological pathway analyses showed that integrin signalling was aberrantly activated in the SPEs of PTC patients with LNM compared to those without LNM. Our study reveals that SPEs of PTC patients with lymph node metastases promote BHT101 thyroid cancer cell invasiveness, but have no apparent influence on cell migration. In the serum exosomes of PTC patients with LNM, integrin-associated proteins are obviously upregulated. These proteomic findings will contribute to elucidation of the pathophysiological functions of tumour-derived exosomes.