microRNA Content Research Articles

Formation and Evaluation of a Two-Phase Polymer System in Human Plasma as a Method for Extracellular Nanovesicle Isolation.

The aim of the study was to explore the polyethylene glycol–dextran two-phase polymer system formed in human plasma to isolate the exosome-enriched fraction of plasma extracellular nanovesicles (ENVs). Systematic analysis was performed to determine the optimal combination of the polymer mixture parameters (molecular mass and concentration) that resulted in phase separation. The separated phases were analyzed by nanoparticle tracking analysis and Raman spectroscopy. The isolated vesicles were characterized by atomic force microscopy and dot blotting. In conclusion, the protein and microRNA contents of the isolated ENVs were assayed by flow cytometry and by reverse transcription followed by quantitative polymerase chain reaction (RT-qPCR), respectively. The presented results revealed the applicability of a new method for plasma ENV isolation and further analysis with a diagnostic purpose.

The micro-RNA content of unsorted cryopreserved bovine sperm and its relation to the fertility of sperm after sex-sorting

BackgroundThe use of sex-sorted sperm in cattle assisted reproduction is constantly increasing. However, sperm fertility can substantially differ between unsorted (conventional) and sex-sorted semen batches of the same sire. Sperm microRNAs (miRNA) have been suggested as promising biomarkers of bull fertility the last years. In this study, we hypothesized that the miRNA profile of cryopreserved conventional sperm is related to bull fertility after artificial insemination with X-bearing sperm. For this purpose, we analyzed the miRNA profile of 18 conventional sperm samples obtained from nine high- (HF) and nine low-fertility (LF) bulls that were contemporaneously used to produce conventional and sex-sorted semen batches. The annual 56-day non-return rate for each semen type (NRRconv and NRRss, respectively) was recorded for each bull.ResultsIn total, 85 miRNAs were detected. MiR-34b-3p and miR-100-5p were the two most highly expressed miRNAs with their relative abundance reaching 30% in total. MiR-10a-5p and miR-9-5p were differentially expressed in LF and HF samples (false discovery rate < 10%). The expression levels of miR-9-5p, miR-34c, miR-423-5p, miR-449a, miR-5193-5p, miR-1246, miR-2483-5p, miR-92a, miR-21–5p were significantly correlated to NRRss but not to NRRconv. Based on robust regression analysis, miR-34c, miR-7859 and miR-342 showed the highest contribution to the prediction of NRRss.ConclusionsA set of miRNAs detected in conventionally produced semen batches were linked to the fertilizing potential of bovine sperm after sex-sorting. These miRNAs should be further evaluated as potential biomarkers of a sire’s suitability for the production of sex-sorted sperm.

Snail Overexpression Alters the microRNA Content of Extracellular Vesicles Released from HT29 Colorectal Cancer Cells and Activates Pro-Inflammatory State In Vivo.

Simple SummaryKnowledge of the factors that help migration of carcinoma cells is important for prevention of metastasis. Cancer cells release small particles, extracellular vesicles (EVs) that contain such factors. The aim of this study was to assess if the content of EVs changes through different stages of colorectal cancer (CRC) and evaluate how this process affects cancer progression in vivo in mouse CRC model. We found that EVs released from cells that have migratory properties contain different factors then EVs released from original tumor cells. We also show here that EVs can be incorporated into other cells that facilitate metastasis and change their properties depending on the EVs content. The content of cell-released EVs may also serve as a biomarker that denotes the stage of CRC and may be a target to prevent cancer progression.During metastasis, cancer cells undergo phenotype changes in the epithelial-mesenchymal transition (EMT) process. Extracellular vesicles (EVs) released by cancer cells are the mediators of intercellular communication and play a role in metastatic process. Knowledge of factors that influence the modifications of the pre-metastatic niche for the migrating carcinoma cells is important for prevention of metastasis. We focus here on how cancer progression is affected by EVs released from either epithelial-like HT29-cells or from cells that are in early EMT stage triggered by Snail transcription factor (HT29-Snail). We found that EVs released from HT29-Snail, as compared to HT29-pcDNA cells, have a different microRNA profile. We observed the presence of interstitial pneumonias in the lungs of mice injected with HT29-Snail cells and the percent of mice with lung inflammation was higher after injection of HT29-Snail-EVs. Incorporation of EVs released from HT29-pcDNA, but not released from HT29-Snail, leads to the increased secretion of IL-8 from macrophages. We conclude that Snail modifications of CRC cells towards more invasive phenotype also alter the microRNA cargo of released EVs. The content of cell-released EVs may serve as a biomarker that denotes the stage of CRC and EVs-specific microRNAs may be a target to prevent cancer progression.

Subpopulations of exosomes purified via different exosomal markers carry different microRNA contents.

The heterogeneity of exosome populations presents a great challenge to their study. The current study was designed to investigate the potential heterogeneity miRNA contents in circulating exosomes purified via different exosomal markers. In this study, exosomes from the serum of C57BL/6 mice after cecum ligation and perforation (CLP) or sham operation were isolated by precipitation using ExoQuick-TC and affinity purified with anti-Rab5b, anti-CD9, anti-CD31, and anti-CD44 antibodies using the Exo-Flow Exosome Capture kit to collect exosome subpopulations. RNA extracted from the exosomes isolated by ExoQuick-TC were profiled by next-generation sequencing (NGS). Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was also employed to determine the expression profiles of four representative exosomal miRNAs (mmu-miR-486-5p, mmu-miR-10a-5p, mmu-miR-143-3p, and mmu-miR-25-3p) selected from the NGS analysis. The results revealed that the expression patterns of these miRNAs in exosomes isolated by ExoQuick-TC as determined by RT-qPCR and NGS were similar, showing upregulation of mmu-miR-10a-5p and mmu-miR-143-3p but downregulation of mmu-miR-25-3p and mmu-miR-486-5p following CLP when compared to the levels in exosomes from sham control mice. However, their expression levels in the antibody-captured exosome subpopulations varied. The miRNAs in the exosomes captured by anti-Rab5b or anti-CD9 antibodies were more similar to those isolated by ExoQuick-TC than to those captured by anti-CD44 antibodies. However, there were no significant differences in these four miRNAs in CD31-captured exosomes. This study demonstrated that purification with different exosomal markers allows the collection of different exosome subpopulations with various miRNA contents. The results of this study demonstrate the heterogeneity of circulating exosomes and suggest the importance of stratifying exosome subpopulations when using circulating exosomes as biomarkers or investigating exosome function. In addition, this study also emphasized the necessity of using a consistent exosome marker across different samples as detecting biomarkers.

MiR-4484 Acts as a Potential Saliva Biomarker for Early Detection of Peri-implantitis.

Peri-implantitis, a potentially progressive disease that occurs in patients with dental implants, is more aggressive than periodontal lesions, which makes the prevention of peri-implantitis an important priority. Due to problems in the early detection of peri-implantitis, there is an urgent need for discovering novel biologic molecules with the ability of early diagnosis. The goal of this study was to profile the microRNA content of saliva samples collected from patients with titanium-aluminum-vanadium alloy dental implants who experienced peri-implantitis and to find potential diagnostic markers for detection of this disease. The microRNA expression profiles of eight saliva samples (four collected from patients with peri-implantitis, four collected from patients who have successful implants) were investigated, and the deregulation of select microRNAs was further confirmed using quantitative polymerase chain reaction. The expressions of 179 microRNAs were found as deregulated in the saliva of peri-implantitis patients in comparison to controls. Then, downregulation of miR-4484 was confirmed in the saliva of peri-implantitis patients in a larger validation cohort. Also, 40% of non-peri-implantitis patients and 78% of peri-implantitis patients had significantly decreased miR-4484 expression in saliva samples collected after 4 to 6 months subsequent to implant placement compared with samples collected before implant placement. Considering these findings, microRNA content of saliva might be proposed as a plausible source for the early diagnosis of peri-implantitis, where miR-4484 might serve as an encouraging early diagnostic biomarker.

Epstein-Barr virus LMP1 manipulates the content and functions of extracellular vesicles to enhance metastatic potential of recipient cells.

Extracellular vesicles (EV) mediate intercellular communication events and alterations in normal vesicle content contribute to function and disease initiation or progression. The ability to package a variety of cargo and transmit molecular information between cells renders EVs important mediators of cell-to-cell crosstalk. Latent membrane protein 1 (LMP1) is a chief viral oncoprotein expressed in most Epstein-Barr virus (EBV)-associated cancers and is released from cells at high levels in EVs. LMP1 containing EVs have been demonstrated to promote cell growth, migration, differentiation, and regulate immune cell function. Despite these significant changes in recipient cells induced by LMP1 modified EVs, the mechanism how this viral oncogene modulates the recipient cells towards these phenotypes is not well understood. We hypothesize that LMP1 alters EV content and following uptake of the LMP1-modified EVs by the recipient cells results in the activation of cell signaling pathways and increased gene expression which modulates the biological properties of recipient cell towards a new phenotype. Our results show that LMP1 expression alters the EV protein and microRNA content packaged into EVs. The LMP1-modified EVs also enhance recipient cell adhesion, proliferation, migration, invasion concomitant with the activation of ERK, AKT, and NF-κB signaling pathways. The LMP1 containing EVs induced transcriptome reprogramming in the recipient cells by altering gene expression of different targets including cadherins, matrix metalloproteinases 9 (MMP9), MMP2 and integrin-α5 which contribute to extracellular matrix (ECM) remodeling. Altogether, our data demonstrate the mechanism in which LMP1-modified EVs reshape the tumor microenvironment by increasing gene expression of ECM interaction proteins.

Similarities and Differences in Extracellular Vesicle Profiles between Ischaemic Stroke and Myocardial Infarction.

Extracellular vesicles (EVs) are involved in intercellular signalling through the transfer of molecules during physiological and pathological conditions, such as ischaemic disease. EVs might therefore play a role in ischaemic stroke (IS) and myocardial infarction (MI). In the present study, we analysed the similarities and differences in the content of circulating EVs in patients with IS and MI. This prospective observational study enrolled 140 participants (81 patients with IS, 37 with MI and 22 healthy controls [HCs]). We analysed the protein and microRNA content from EVs using proteomics and reverse transcription quantitative real-time polymerase chain reaction and compared it between the groups. In the patients with IS and MI, we identified 14 common proteins. When comparing IS and MI, we found differences in the protein profiles (apolipoprotein B, alpha-2-macroglobulin, fibronectin). We also found lower levels of miR-340 and miR-424 and higher levels of miR-29b in the patients with IS and MI compared with the HCs. Lastly, we found higher miR-340 levels in IS than in MI. In conclusion, proteomic and miRNA analyses suggest a relationship between circulating EV content and the patient’s disease state. Although IS and MI affect different organs (brain and heart) with distinct histological characteristics, certain EV proteins and miRNAs appear to participate in both diseases, while others are present only in patients with IS.

Effect of collection matrix, platelet depletion, and storage conditions on plasma extracellular vesicles and extracellular vesicle-associated miRNAs measurements.

The interest around circulating extracellular vesicles and their cargo in diagnostics has greatly increased; however, several pre-analytical variables affect their determination. In this study, we investigated the effects of sample matrix, processing, and plasma storage delay and temperature on extracellular vesicles and their miRNA content. Blood was collected from 10 male volunteers in dipotassium ethylendiaminotetraacetate-coated tubes (K2EDTA), either with plasma-preparation tube (PPT) or without (K2E) gel separator. A stepwise centrifugation was applied to K2E aliquots to obtain platelet-poor plasma (PPP). K2E, PPP and PPT plasma, stored under different conditions, were assayed for extracellular vesicles concentration and size distribution, through dynamic laser light scattering, and microRNAs content, by qPCR. PPP samples were characterized by the lowest extracellular vesicles count and miRNA detectability. Although having no effects on extracellular vesicles total concentration, storage conditions influenced microRNAs detectability, mainly in PPP and PPT samples. Extracellular vesicles-associated miRNAs levels in K2E were, in general, higher than in PPP and to a very limited extent to PPT. Storage temperature and delay did not affect their profile in K2E samples. Extracellular vesicles count and extracellular vesicles miRNA profile changed under the analyzed pre-analytical variables, showing the greatest stability in K2E samples. Since pre-analytical variables differently affected extracellular vesicles and their miRNA content, they should be considered in each experimental setting and clinical routine.

MRNA and miRNA Profiles of Exosomes from Cultured Tumor Cells Reveal Biomarkers Specific for HPV16-Positive and HPV16-Negative Head and Neck Cancer.

Human papillomavirus (HPV)(+) and HPV(−) head and neck cancer (HNC) cells’ interactions with the host immune system are poorly understood. Recently, we identified molecular and functional differences in exosomes produced by HPV(+) vs. HPV(−) cells, suggesting that genetic cargos of exosomes might identify novel biomarkers in HPV-related HNCs. Exosomes were isolated by size exclusion chromatography from supernatants of three HPV(+) and two HPV(−) HNC cell lines. Paired cell lysates and exosomes were analyzed for messenger RNA (mRNA) by qRT-PCR and microRNA (miR) contents by nanostring analysis. The mRNA profiles of HPV(+) vs. HPV(−) cells were distinct, with EGFR, TP53 and HSPA1A/B overexpressed in HPV(+) cells and IL6, FAS and DPP4 in HPV(−) cells. The mRNA profiles of HPV(+) or HPV(−) exosomes resembled the cargo of their parent cells. miR expression profiles in cell lysates identified 8 miRs expressed in HPV(−) cells vs. 14 miRs in HPV(+) cells. miR-205-5p was exclusively expressed in HPV(+) exosomes, and miR-1972 was only detected in HPV(−) exosomes. We showed that HPV(+) and HPV(−) exosomes recapitulated the mRNA expression profiles of their parent cells. Expression of miRs was dependent on the HPV status, and miR-205-5p in HPV(+) and miR-1972 in HPV(−) exosomes emerge as potential discriminating HPV-associated biomarkers.

Hypoxia and extracellular vesicles: A review on methods, vesicular cargo and functions.

Hypoxia is an essential hallmark of several serious diseases such as cardiovascular and metabolic disorders and cancer. A decline in the tissue oxygen level induces hypoxic responses in cells which strive to adapt to the changed conditions. A failure to adapt to prolonged or severe hypoxia can trigger cell death. While some cell types, such as neurons, are highly vulnerable to hypoxia, cancer cells take advantage of a hypoxic environment to undergo tumour growth, angiogenesis and metastasis. Hypoxia‐induced processes trigger complex intercellular communication and there are now indications that extracellular vesicles (EVs) play a fundamental role in these processes. Recent developments in EV isolation and characterization methodology have increased the awareness of the importance of EV purity in functional and cargo studies. Cell death, a hallmark of severe hypoxia, is a known source of intracellular contaminants in isolated EVs. In this review, methodological aspects of studies investigating hypoxia‐induced EVs are critically evaluated. Key concerns and gaps in the current knowledge are highlighted and future directions for studies are set. To accelerate and advance research, an in‐depth analysis of the functions and cargo of hypoxic EVs, compared to normoxic EVs, is provided with the focus on the altered microRNA contents of the EVs.

Targeting IL-3Rα on tumor-derived endothelial cells blunts metastatic spread of triple-negative breast cancer via extracellular vesicle reprogramming

The lack of approved targeted therapies highlights the need for new treatments for triple-negative breast cancer (TNBC) patients. Interleukin-3 (IL-3) acts as an autocrine factor for tumor–endothelial cells (TEC), and exerts pro-angiogenic paracrine action via extracellular vesicles (EVs). IL-3Rα blockade on TEC changes TEC-EV (anti-IL-3R-EV) microRNA (miR) content and promotes the regression of established vessels. As TEC is the doorway for “drug” entry into tumors, we aimed to assess whether IL-3R blockade on TEC impacts tumor progression via its unique EV cargo. First, the expression of IL-3Rα was evaluated in 27 human TNBC samples. It was noticed that, besides TEC and inflammatory cells, tumor cells from 55.5% of the human TNBC samples expressed IL-3Rα. Using human TNBC cell lines for in vitro studies, we found that, unlike native TEC-EVs (nEVs), anti-IL-3R-EVs increase apoptosis and reduced cell viability and migration. In vivo, anti-IL-3R-EV treatment induced vessel regression in established tumors formed of MDA-MB-231 cells, decreased Vimentin, β-catenin, and TWIST1 expression, almost abolished liver and lung metastases from primary tumors, and reduced lung metastasis generated via the intravenous injection of MDA-MB-231 cells. nEVs depleted of miR-24-3p (antago-miR-24-3p-EVs) were effective as anti-IL-3R-EVs in downregulating TWIST1 and reducing metastatic lesions in vivo. Consistent with network analyses of miR-24-3p gene targeting, anti-IL-3R-EVs and antago-miR-24-3p-EVs upregulate SPRY2 in MDA-MB-231 cells. Finally, SPRY2 silencing prevented anti-IL-3R-EV and antago-miR-24-3p-EV-mediated apoptotic cues.Overall, these data provide the first evidence that IL-3Rα is highly expressed in TNBC cells, TEC, and inflammatory cells, and that IL-3Rα blockade on TEC impacts tumor progression.

Identification and Analysis of microRNAs in Chlorella sorokiniana Using High-Throughput Sequencing.

Chlorella is a popular microalga with robust physiological and biochemical characteristics, which can be cultured under various conditions. The exploration of the small RNA content of Chlorella could improve strategies for the enhancement of metabolite production from this microalga. In this study, stress was introduced to the Chlorella sorokiniana culture to produce high-value metabolites such as carotenoids and phenolic content. The small RNA transcriptome of C. sorokiniana was sequenced, focusing on microRNA (miRNA) content. From the analysis, 98 miRNAs were identified in cultures subjected to normal and stress conditions. The functional analysis result showed that the miRNA targets found were most often involved in the biosynthesis of secondary metabolites, followed by protein metabolism, cell cycle, and porphyrin and chlorophyll metabolism. Furthermore, the biosynthesis of secondary metabolites such as carotenoids, terpenoids, and lipids was found mostly in stress conditions. These results may help to improve our understanding of regulatory mechanisms of miRNA in the biological and metabolic process of Chlorella species. It is important and timely to determine the true potential of this microalga species and to support the potential for genetic engineering of microalgae as they receive increasing focus for their development as an alternative source of biofuel, food, and health supplements.

Impact of Bone Marrow miR-21 Expression on Acute Myeloid Leukemia T Lymphocyte Fragility and Dysfunction.

Background: Acute myeloid leukemia (AML) is a hematopoietic malignancy in which antitumor immunity is impaired. The therapeutic management of AML requires understanding the mechanisms involved in the fragility and immune dysfunction of AML T lymphocytes. Methods: In this study, T lymphocytes from healthy donors (HD) and AML patients were used. Extracellular vesicles (EVs) from leukemic cells were screened for their microRNA content and impact on T lymphocytes. Flow cytometry, transcriptomic as well as lentiviral transduction techniques were used to carry out the research. Results: We observed increased cell death of T lymphocytes from AML patients. EVs from leukemia myeloid cell lines harbored several miRNAs, including miR-21, and were able to induce T lymphocyte death. Compared to that in HD, miR-21 was overexpressed in both the bone marrow fluid and infiltrating T lymphocytes of AML patients. MiR-21 induces T lymphocyte cell death by upregulating proapoptotic gene expression. It also increases the immunosuppressive profile of T lymphocytes by upregulating the IL13, IL4, IL10, and FoxP3 genes. Conclusions: Our results demonstrate that miR-21 plays a significant role in AML T lymphocyte dysfunction and apoptosis. Targeting miR-21 may be a novel approach to restore the efficacy of the immune response against AML.

Metabolic syndrome increases senescence-associated micro-RNAs in extracellular vesicles derived from swine and human mesenchymal stem/stromal cells

BackgroundThe metabolic syndrome (MetS) is a combination of cardiovascular risk-factors, including obesity, hypertension, hyperglycemia, and insulin resistance. MetS may induce senescence in mesenchymal stem/stromal cells (MSC) and impact their micro-RNA (miRNA) content. We hypothesized that MetS also alters senescence-associated (SA) miRNAs in MSC-derived extracellular vesicles (EVs), and interferes with their function.MethodsEVs were collected from abdominal adipose tissue-derived MSCs from pigs with diet-induced MetS or Lean controls (n = 6 each), and from patients with MetS (n = 4) or age-matched Lean controls (n = 5). MiRNA sequencing was performed to identify dysregulated miRNAs in these EVs, and gene ontology to analyze their SA-genes targeted by dysregulated miRNAs. To test for EV function, MetS and Lean pig-EVs were co-incubated with renal tubular cells in-vitro or injected into pigs with renovascular disease (RVD, n = 6 each) in-vivo. SA-b-Galactosidase and trichrome staining evaluated cellular senescence and fibrosis, respectively.ResultsBoth humans and pigs with MetS showed obesity, hypertension, and hyperglycemia/insulin resistance. In MetS pigs, several upregulated and downregulated miRNAs targeted 5768 genes in MSC-EVs, 68 of which were SA. In MetS patients, downregulated and upregulated miRNAs targeted 131 SA-genes, 57 of which overlapped with pig-EVs miRNA targets. In-vitro, MetS-MSC-EVs induced greater senescence in renal tubular cells than Lean-MSC-EVs. In-vivo, Lean-MSC-EVs attenuated renal senescence, fibrosis, and dysfunction more effectively than MetS-MSC-EVs.ConclusionsMetS upregulates SA-miRNAs in swine MSC-EVs, which is conserved in human subjects, and attenuates their ability to blunt cellular senescence and repair injured target organs. These alterations need to be considered when designing therapeutic regenerative approaches.6zqxia-CrPNCC_V2gsDzjqVideo abstractGraphical abstract

Abstract 475: Beta-adrenoceptor Stimulation Uniquely Regulates Exosome Micro-rna Content Secreted From Cardiomyocytes in vitro and Those Found in vivo Circulating in Blood

Background and Purpose: The influence of β-adrenoceptor (βAR) signaling on the regulation of exosomes secreted from cardiomyocytes is unknown and since catecholamines are increased in heart failure (HF), there is interest in uncovering whether βARs can induce specific changes in the content of circulating blood exosomes in HF. In this study, we have evaluated whether βAR stimulation by isoproterenol (ISO) on neonatal rat ventricle myocytes (NRVMs) and in vivo in mice can alter the number, size and microRNA (miR) content of secreted exosomes. Methods and Results: ISO treatment of NRVMs did not change exosome number and size of compared than vehicle (PBS). After purifying total RNA from treated myocytes and secreted exosomes, we evaluated the expression level of 37 candidate miR’s, which were selected from previous microarray data. We found that ISO treatment decreased 14 miR’s (miR-222, -106a, -292a, -181b, -210, -489, -214, -1947, -195, -17, -7b, -93, -532 and -19a) in exosomes and in the myocytes themselves, mir-292a and -1947 were up regulated and mir-7b, down regulated. Further, ISO was then used to treat C57 mice via osmotic pump chronically. The number and size of exosomes purified from circulating blood was not changed after 2 and 8 weeks. We evaluated expression of the 14 miRs down-regulated in myocytes as well miR-1 and -21 (important cardiac miRs) both in the blood and hearts of ISO-treated mice. MiR-1 did not change in both blood exosomes and heart tissue and miR-21 was up-regulated in heart tissue but not in blood both at 2 and 8 weeks after ISO treatment. In addition, miRNA-489 and -7b was down-regulated in hearts with miR-214 and -292a up regulated. In blood exosomes, we found only down-regulation of miR-489 and -7b but not miR-214 and 292a. Conclusions: We found that the βAR agonist ISO altered exosomal miR contents but not exosome size and number from myocytes. Importantly, this was found in myocytes in culture and in vivo blood and myocardium that were treated with ISO but several differences were found and changes in blood and myocytes were not homogeneous. However, two miRs, mir-7b and -miR-489, both changes similarly from their origin (NRVMs or mouse hearts) and also in circulating blood exosomes. Therefore, these miRs may represent biomarkers for sympathetic nervous system abnormalities in HF and their therapeutic potential should be evaluated.

Impact of processing method on donated human breast milk microRNA content.

Pasteurization of donated human milk preserves it for storage and makes it safe for feeding, but at the expense of its composition, nutritional values and functions. Here, we aimed to investigate the impact of Holder Pasteurization (HoP) and High Pressure Processing (HPP) methods on miRNA in human milk and to evaluate impact of these changes on miRNA functions. Milk samples obtained from women in 50th day of lactation (n = 3) were subjected either to HoP, HPP or remained unpasteurized as a control. Subsequently, miRNA was isolated from whole material and exosomal fraction and sequenced with Illumina NextSeq 500. Sequencing data were processed, read counts were mapped to miRNA and analyzed both quantitatively with DESeq2 and functionally with DIANA mirPath v.3. While HPP caused statistically insignificant decrease in number of miRNA reads compared to unprocessed material, HoP led to 82-fold decrease in whole material (p = 0.0288) and 302-fold decrease in exosomes (p = 0.0021) not leaving enough reads for further analysis. Changes in composition of miRNA fraction before and after HPP indicated uneven stability of individual miRNAs under high pressure conditions, with miR-30d-5p identified as relatively stable and miR-29 family as sensitive to HPP. Interestingly, about 2/3 of unprocessed milk miRNA content consists of only 10 distinct miRNAs with miR-148a-3p at the top. Functional analysis of most abundant human milk miRNAs showed their involvement in signaling pathways, cell communication, proliferation and metabolism that are obviously important in rapidly growing infants. Functions of miRNAs which suffered the greatest depletion during HPP were similar to roles of the majority of unprocessed human milk's miRNA, which indicates that those functions may be weakened although not completely lost. Our findings indicate that HPP is less detrimental to human milk miRNAs than HoP and should be considered in further research on recommended processing procedures for human milk banks.

Docosahexaenoic acid (DHA) inhibits pro-angiogenic effects of breast cancer cells via down-regulating cellular and exosomal expression of angiogenic genes and microRNAs

AimsDocosahexaenoic acid (DHA) as an omega 3 free fatty acid has been reported to exert anti-angiogenesis effects. However, our current understanding regarding the precise mechanisms of such effects is still limited. Exosomes secreted by cancer cells may act as angiogenesis promoters. The aim of the study was to determine altered expression levels of HIF-1α, TGF-β, VEGFR, Snail1, Snail2 and SOX2 and their regulating microRNAs in MDA-MB-231 and BT-474 cell lines after treatment with DHA in both normoxic and hypoxic conditions. Main methodsHuman breast cancer cell lines including MDA-MB-231 and BT-474 were treated for 24 h with 100 uM DHA under normoxic and hypoxic conditions. Exosomes were isolated from untreated and treated cells and characterized by transmission electron microscopy (TEM) and western blotting. RNAs from cells and isolated exosomes were extracted and cDNAs were synthesized. Expression levels of miRNAs and their pro-angiogenic target genes were analyzed using quantitative real-time PCR (qRT-PCR). Key findingsWe showed significant decrease in the expression of pro-angiogenic genes including HIF1-α, TGF-β, SOX2, Snail1, Snail2 and VEGFR in cells and also their secreted exosomes after treatment with DHA in normoxic and hypoxic conditions. Also the expression levels of tumor suppressor miRs including miR-101, miR-199, miR-342 were increased and the expression levels of oncomiRs including mir-382 and miR-21 were decreased after treatment with DHA in cells and exosomes. SignificanceDHA can alter the expression of pro-angiogenic genes and microRNA contents in breast cancer cells and their derived-exosomes in favor of the inhibition of angiogenesis. Our data demonstrated new insight into DHA's anti-cancer action to target not only breast cancer cells but also their derived exosomes to suppress tumor angiogenesis.

Carotid Plaque-derived Extracellular Vesicle MicroRNA Content Differs Between Symptomatic and Asymptomatic Stenosis

Elucidating the biological processes that drive asymptomatic plaque to become symptomatic is important for the development of therapeutics to stabilize carotid plaque and prevent stroke. Given that extracellular vesicle (EV)-derived microRNAs (miRNA) mediate cellular communication, we hypothesized that their cargo will differ in symptomatic versus asymptomatic plaque and play a role in plaque instability.

Plasma Extracellular Vesicle Subtypes as Potential Biomarkers of Immune Activation in HIV-Infected Patients

Chronic immune activation and systemic inflammation during HIV infection despite effective antiretroviral therapy (ART) is associate with non-AIDS co-morbidities in people living with HIV (PLWH). Previous studies have shown that plasma levels of extracellular vesicles (EVs) may be used as immune activation or inflammatory biomarkers of HIV disease progression. Several studies have focused on microRNA and mitochondrial DNA (mtDNA) levels reached concomitantly in immune cells and EVs. We hypothesized that large and small EVs could contain different amounts of microRNA and mtDNA and that could reflect immune activation associated with elevated CD8 T cell count or low CD4/CD8 ratio in PLWH receiving ART. Plasma EVs obtained from PLWH and uninfected control were sized using dynamic light scattering and quantified using flow cytometry. Expression of mature miR-92, miR-155, miR-223 and mtDNA was measured by qRT-PCR. Positive correlation have been observed between CD8+ T cell count and large EV abundance, AChE activity in small EVs and negative correlation with miR-155 levels in small EVs. CD4/CD8 ratio was positively correlated with large EVs abundance and negatively with AChE activity in small EVs and PMN-associated copies of miR-92. MicroRNA-155 level in small EVs were positively correlated with monocyte counts. MiR-155 and mtDNA contents of large EVs were increased more than miR-92 and miR-223 contents in small EVs. A positive correlation was observed between large EVs mtDNA content and CD4 T cell count. These findings suggest that profiling the microRNA and mtDNA contents of EV might provide new functional biomarkers of immune activation and inflammation. Funding Statement: This study was funded through Canadian Institutes of Health Research (CIHR) grants MOP 188726; MOP-267056 (HIV/AIDS initiative) to C.G., MOP-03230 to J.P.R. and to C.T. for the cohort establishment and CIHR Foundation Grant FDN-143218 to M.A. for the studentship awarded to W.W.B., as well as by the Fonds de recherche du Quebec – Sante (FRQ-S) AIDS and infectious diseases network. C.T. is an FRQ-S scholar and holder of the Pfizer/Universite de Montreal chair on HIV translational Research. J-P.R. holds the Louis Lowenstein chair in Hematology & Oncology at McGill University. M-A.J. holds a CIHR Canada Research Chair tier 2 in Immuno-Virology. The infrastructure of the Centre de recherche du CHU de Quebec – Universite Laval is supportes by the FRQ-S. Declaration of Interests: The authors declare that no competing interests exist. Ethics Approval Statement: This study received approval from the ethics review boards of Centre de recherche du CHU de Quebec, Quebec, Canada and the McGill University Health Centre, Montreal, Quebec, Canada. All subjects were anonymous volunteers and provided written informed consent to participate in the study.

Stratification of papillary thyroid cancer relapse risk based on the results of molecular genetic studies

Introduction. Post-transcriptional mechanisms play a crucial role in the biological course and clinical manifestations of papillary thyroid cancer (PTC). Recent studies show that an increased content of oncogenic or reduced content of oncosuppressive microRNAs increases the aggressiveness of the tumor and correlates with an unfavorable prognosis of treatment, which allows them to be used in personalizing the treatment tactics of patients with PTC. The study objective is to compare the level of expression of 12 PTC-specific microRNAs and the frequency of V600E mutation of the BRAF gene in patients with different risk of relapse. Materials and methods. The study included 175 patients with PTC. For quantitative analysis of microRNA expression, a reverse transcription reaction followed by a real-time polymerase chain reaction in formalin-fixed paraffin blocks was used. Correlations between 12 microRNA expression and BRAF mutation with different clinical and anatomical features of PTC the risk of relapse according to the American Thyroid Association Risk Stratification System (2009) were analyzed. Results. We demonstrated that miR-146b, miR-221, miR-144, miR-451a, and miR-7 expression correlated with features such as extrathyroid tumor growth, larger size, multifocus, lymph node metastasis, and the presence of distant metastases of the PTC. Most importantly, miR-221, miR-144, miR-451a, and miR-7 expression correlated with risk levels, suggesting their potential significance in stratifying the risk of relapsing PTC. The dependence of the clinical behavior of PTC on the BRAF mutation has not been established.Conclusion. The result of the study will contribute to the individual choice of preoperative treatment tactics for patients with PTC.