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Fulltext Pathogenic Role of Exosomes in Epstein-Barr Virus (EBV)-Associated Cancers

Teow SY, Liew K, Khoo AS, Peh SC

Int J Biol Sci, 2017;13(10):1276-1286.
PMID: 29104494 DOI: 10.7150/ijbs.19531

Exosomes are 40- to 100-nm membrane-bound small vesicles that carry a great variety of cellular cargoes including proteins, DNA, messenger RNAs (mRNAs), and microRNAs (miRNAs). These nanovesicles are detected in various biological fluids such as serum, urine, saliva, and seminal fluids. Exosomes serve as key mediators in intercellular communication by facilitating the transfer and exchange of cellular components from cells to cells. They contain various pathogenic factors whereby their adverse effects have been implicated in multiple viral infections and cancers. Interestingly, accumulating evidences showed that exosomes derived from tumour viruses or oncoviruses, exacerbate virus-associated cancers by remodelling the tumour microenvironment. In this review, we summarize the contributing factors of Epstein-Barr virus (EBV) products-containing exosomes in viral pathogenesis and their potential implications in EBV-driven malignancies. Understanding the biological role of these exosomes in the disease would undoubtedly boost the development of a more comprehensive strategy to combat EBV-associated cancers and to better predict the therapeutic outcomes. Furthermore, we also highlight the potentials and challenges of EBV products-containing exosomes being employed as diagnostic markers and therapeutic targets for EBV-related cancers. Since these aspects are rather underexplored, we attempt to underline interesting areas that warrant further investigations in the future.

Matched MeSH terms: Exosomes/genetics*
Fulltext Exosomal MicroRNA-15a Transfer from the Pancreas Augments Diabetic Complications by Inducing Oxidative Stress

Kamalden TA, Macgregor-Das AM, Kannan SM, Dunkerly-Eyring B, Khaliddin N, Xu Z, et al.

Antioxid Redox Signal, 2017 Nov 01;27(13):913-930.
PMID: 28173719 DOI: 10.1089/ars.2016.6844

AIMS: MicroRNAs (miRNAs), one type of noncoding RNA, modulate post-transcriptional gene expression in various pathogenic pathways in type 2 diabetes (T2D). Currently, little is known about how miRNAs influence disease pathogenesis by targeting cells at a distance. The purpose of this study was to investigate the role of exosomal miRNAs during T2D.
RESULTS: We show that miR-15a is increased in the plasma of diabetic patients, correlating with disease severity. miR-15 plays an important role in insulin production in pancreatic β-cells. By culturing rat pancreatic β-cells (INS-1) cells in high-glucose media, we identified a source of increased miR-15a in the blood as exosomes secreted by pancreatic β-cells. We postulate that miR-15a, produced in pancreatic β-cells, can enter the bloodstream and contribute to retinal injury. miR-15a overexpression in Müller cells can be induced by exposing Müller cells to exosomes derived from INS-1 cells under high-glucose conditions and results in oxidative stress by targeting Akt3, which leads to apoptotic cell death. The in vivo relevance of these findings is supported by results from high-fat diet and pancreatic β-cell-specific miR-15a-/- mice.
INNOVATION: This study highlights an important and underappreciated mechanism of remote cell-cell communication (exosomal transfer of miRNA) and its influence on the development of T2D complications.
CONCLUSION: Our findings suggest that circulating miR-15a contributes to the pathogenesis of diabetes and supports the concept that miRNAs released by one cell type can travel through the circulation and play a role in disease progression via their transfer to different cell types, inducing oxidative stress and cell injury. Antioxid. Redox Signal. 27, 913-930.

Matched MeSH terms: Exosomes/genetics
Fulltext Exosomal miR-224 contributes to hemolymph microbiota homeostasis during bacterial infection in crustacean

Gong Y, Wei X, Sun W, Ren X, Chen J, Aweya JJ, et al.

PLoS Pathog, 2021 08;17(8):e1009837.
PMID: 34379706 DOI: 10.1371/journal.ppat.1009837

It is well known that exosomes could serve as anti-microbial immune factors in animals. However, despite growing evidences have shown that the homeostasis of the hemolymph microbiota was vital for immune regulation in crustaceans, the relationship between exosomes and hemolymph microbiota homeostasis during pathogenic bacteria infection has not been addressed. Here, we reported that exosomes released from Vibrio parahaemolyticus-infected mud crabs (Scylla paramamosain) could help to maintain the homeostasis of hemolymph microbiota and have a protective effect on the mortality of the host during the infection process. We further confirmed that miR-224 was densely packaged in these exosomes, resulting in the suppression of HSP70 and disruption of the HSP70-TRAF6 complex, then the released TRAF6 further interacted with Ecsit to regulate the production of mitochondrial ROS (mROS) and the expression of Anti-lipopolysaccharide factors (ALFs) in recipient hemocytes, which eventually affected hemolymph microbiota homeostasis in response to the pathogenic bacteria infection in mud crab. To the best of our knowledge, this is the first document that reports the role of exosome in the hemolymph microbiota homeostasis modulation during pathogen infection, which reveals the crosstalk between exosomal miRNAs and innate immune response in crustaceans.

Matched MeSH terms: Exosomes/genetics*
Potential biomarkers in NASH-induced liver cirrhosis with hepatocellular carcinoma: A preliminary work on roles of exosomal miR-182, miR-301a, and miR-373

Muhammad Yusuf AN, Raja Ali RA, Muhammad Nawawi KN, Mokhtar NM

Malays J Pathol, 2020 Dec;42(3):377-384.
PMID: 33361718

INTRODUCTION: Recent studies have published the roles of exosomal miRNAs in the pathogenesis of various type of malignancies and can be developed as potential biomarkers for diagnostic, prognostic and therapeutic purposes. The aim of this study was to identify the expression level of selected miRNAs (miR-182, miR-301a, and miR-373) in exosomes of the serum and ascitic fluid in patients with non-alcoholic steatohepatitis (NASH)-related liver cirrhosis with or without hepatocellular carcinoma (HCC).
MATERIALS AND METHODS: A literature search was performed to identify potential miRNAs involved in the pathogenesis of HCC. Unpaired serum and ascitic fluid were obtained from 52 patients with NASH related liver cirrhosis (n=26 for each group of with and without HCC). Exosomal miRNA was isolated from all samples. Expression levels of miR-182, miR-301a and miR- 373 were determined using quantitative real-time PCR.
RESULTS: Serum-derived exosomal mir-182, miR-301a and miR-373 were significantly up-regulated with fold change of 1.77, 2.52, and 1.67 (p< 0.05) respectively in NASH-induced liver cirrhosis with HCC as compared to NASH-induced liver cirrhosis without HCC. We identified the expression levels of ascitic fluid-derived exosomal mir-182, miR-301a, and miR-373 were significantly up-regulated with fold change of 1.6, 1.94 and 2.13 respectively in NASH-induced liver cirrhosis with HCC as compared to NASH-induced liver cirrhosis without HCC (p <0.05). There was poor correlation expression of all the selected exosomal miRNA between serum- and ascitic fluid-derived in HCC group.
CONCLUSIONS: This preliminary data showed significant increase in the expression levels of exosomal miR-182, miR-301a and miR- 373 in both serum and ascetic fluid suggesting the possible roles of these miRNAs as circulating biomarkers for NASH-induced liver cirrhosis with hepatocellular carcinoma.

Matched MeSH terms: Exosomes/genetics
Intracellular and exosomal microRNAome profiling of human vascular smooth muscle cells during replicative senescence

Nguyen DDN, Zain SM, Kamarulzaman MH, Low TY, Chilian WM, Pan Y, et al.

Am J Physiol Heart Circ Physiol, 2021 10 01;321(4):H770-H783.
PMID: 34506226 DOI: 10.1152/ajpheart.00058.2021

Vascular aging is highly associated with cardiovascular morbidity and mortality. Although the senescence of vascular smooth muscle cells (VSMCs) has been well established as a major contributor to vascular aging, intracellular and exosomal microRNA (miRNA) signaling pathways in senescent VSMCs have not been fully elucidated. This study aimed to identify the differential expression of intracellular and exosomal miRNA in human VSMCs (hVSMCs) during replicative senescence. To achieve this aim, intracellular and exosomal miRNAs were isolated from hVSMCs and subsequently subjected to whole genome small RNA next-generation sequencing, bioinformatics analyses, and qPCR validation. Three significant findings were obtained. First, senescent hVSMC-derived exosomes tended to cluster together during replicative senescence and the molecular weight of the exosomal protein tumor susceptibility gene 101 (TSG-101) increased relative to the intracellular TSG-101, suggesting potential posttranslational modifications of exosomal TSG-101. Second, there was a significant decrease in both intracellular and exosomal hsa-miR-155-5p expression [n = 3, false discovery rate (FDR) < 0.05], potentially being a cell type-specific biomarker of hVSMCs during replicative senescence. Importantly, hsa-miR-155-5p was found to associate with cell-cycle arrest and elevated oxidative stress. Lastly, miRNAs from the intracellular pool, that is, hsa-miR-664a-3p, hsa-miR-664a-5p, hsa-miR-664b-3p, hsa-miR-4485-3p, hsa-miR-10527-5p, and hsa-miR-12136, and that from the exosomal pool, that is, hsa-miR-7704, were upregulated in hVSMCs during replicative senescence (n = 3, FDR < 0.05). Interestingly, these novel upregulated miRNAs were not functionally well annotated in hVSMCs to date. In conclusion, hVSMC-specific miRNA expression profiles during replicative senescence potentially provide valuable insights into the signaling pathways leading to vascular aging.NEW & NOTEWORTHY This is the first study on intracellular and exosomal miRNA profiling on human vascular smooth muscle cells during replicative senescence. Specific dysregulated sets of miRNAs were identified from human vascular smooth muscle cells. Hsa-miR-155-5p was significantly downregulated in both intracellular and exosomal hVSMCs, suggesting its crucial role in cellular senescence. Hsa-miR-155-5p might be the mediator in linking cellular senescence to vascular aging and atherosclerosis.

Matched MeSH terms: Exosomes/genetics
Fulltext Role of exosomes as a proinflammatory mediator in the development of EBV-associated lymphoma

Higuchi H, Yamakawa N, Imadome KI, Yahata T, Kotaki R, Ogata J, et al.

Blood, 2018 06 07;131(23):2552-2567.
PMID: 29685921 DOI: 10.1182/blood-2017-07-794529

Epstein-Barr virus (EBV) causes various diseases in the elderly, including B-cell lymphoma such as Hodgkin's lymphoma and diffuse large B-cell lymphoma. Here, we show that EBV acts in trans on noninfected macrophages in the tumor through exosome secretion and augments the development of lymphomas. In a humanized mouse model, the different formation of lymphoproliferative disease (LPD) between 2 EBV strains (Akata and B95-8) was evident. Furthermore, injection of Akata-derived exosomes affected LPD severity, possibly through the regulation of macrophage phenotype in vivo. Exosomes collected from Akata-lymphoblastoid cell lines reportedly contain EBV-derived noncoding RNAs such as BamHI fragment A rightward transcript (BART) micro-RNAs (miRNAs) and EBV-encoded RNA. We focused on the exosome-mediated delivery of BART miRNAs. In vitro, BART miRNAs could induce the immune regulatory phenotype in macrophages characterized by the gene expressions of interleukin 10, tumor necrosis factor-α, and arginase 1, suggesting the immune regulatory role of BART miRNAs. The expression level of an EBV-encoded miRNA was strongly linked to the clinical outcomes in elderly patients with diffuse large B-cell lymphoma. These results implicate BART miRNAs as 1 of the factors regulating the severity of lymphoproliferative disease and as a diagnostic marker for EBV+ B-cell lymphoma.

Matched MeSH terms: Exosomes/genetics