microRNAs In Circulation Research Articles

Maternal diet quality and circulating extracellular vesicle and particle miRNA during pregnancy

PurposeDuring pregnancy, extracellular vesicle and particle microRNAs (EVP miRNA) in maternal circulation have the capacity to cross the placenta and facilitate maternal-fetal communication. Both dysregulation of circulating EVP miRNA during pregnancy and maternal diet quality have been previously associated with pregnancy complications and adverse birth outcomes. However, little is known about how maternal diet influences circulating EVP miRNA during pregnancy. This study assesses associations between maternal diet quality, as measured by the Alternative Healthy Eating Index (2010; AHEI-2010), and EVP miRNA levels in maternal circulation during pregnancy.MethodsIn a pilot study of 53 pregnant participants in the New Hampshire Birth Cohort Study, maternal diet quality was assessed using AHEI-2010 and plasma (mean gestational age at blood collection: 28.8 weeks) EVP miRNA were profiled using the NanoString nCounter platform which interrogates 798 miRNA transcripts.ResultsIn covariate-adjusted models, the AHEI-2010 adherence score was negatively associated (P < 0.05) with the number of unique miRNA transcripts detectable in each sample. In post hoc analyses, greater consumption of red and processed meats was positively associated with levels of 7 miRNA (Q < 0.05), including hsa-miR-512-5p (PBonf < 0.01), a member of the placenta-specific chromosome 19 miRNA cluster.ConclusionWe identified associations between the consumption of red and processed meat and levels of circulating select EVP miRNA during pregnancy, including placenta-specific miRNA and miRNA with target genes overrepresented in pathways involved in placental development. Additional research is needed to assess whether alterations in maternal circulating EVP miRNA may mediate maternal diet quality’s impacts on pregnancy and birth outcomes.

Transport of miR-766–3p to A549 cells by plasma-derived exosomes and its effect on intracellular survival of Mycobacterium tuberculosis by regulating NRAMP1 expression in A549 cells

Exosomal microRNAs (miRNAs) in circulation were recognized as potential biomarkers for the diagnosis of multiple diseases. However, its potential as a diagnostic hallmark for tuberculosis (TB) has yet to be explored. Here, we comprehensively analyze miRNA profiles in exosomes derived from the plasma of active TB patients and healthy persons to evaluate its efficacy in TB diagnosis. Small-RNA transcriptomic profiling analysis identified a total of 14 differentially expressed miRNAs (DEmiRNAs), among which the diagnostic potential of exosomal miR-766–3p, miR-376c-3p, miR-1283, and miR-125a-5p was evident from their respective areas under the ROC curve, which were 0.8963, 0.8313, 0.8097, and 0.8050, respectively. The bioinformatics analysis and Luciferase reporter assays confirmed that the 3′-untranslated region of natural resistance-associated macrophage protein 1 (NRAMP1) mRNA was targeted by miR-766–3p. The exosomes could be internalized by the A549 cells in co-culturing experiments. Furthermore, both increased miR-766–3p and decreased NRAMP1 expression were observed in Mtb-infected A549 cells. MiR-766–3p overexpression reduced the NRAMP1 levels, but increased intracellular Mtb, suggesting that miR-766–3p may facilitate Mtb survival by targeting NRAMP1. Moreover, miR-766–3p-transfected cells exhibited increased apoptosis and reduced proliferation following Mtb infection. Taken together, circulating exosomal miR-766–3p, miR-1283, miR-125a-5p, and miR-376c-3p may serve as candidate hallmarks for TB diagnosis where the presence of miR-766–3p seems associated with the vulnerability to Mtb infection in humans and could be a new molecular target for therapeutic intervention of TB.

Adipocyte-derived exosomal miR-22-3p modulated by circadian rhythm disruption regulates insulin sensitivity in skeletal muscle cells

Circadian rhythm disruption leads to dysregulation of lipid metabolism, which further drive the occurrence of insulin resistance (IR). Exosomes are natural carrier systems that advantageous for cell communication. In the present study, we aimed to explore whether and how the exosomal microRNAs (miRNAs) in circulation participate in modulating skeletal muscle IR induced by circadian rhythm disruption. In the present study, 24-h constant light (12-h light/12-h light, LL) was used to establish the mouse model of circadian rhythm disruption. Bmal1 interference was used to establish the cell model of circadian rhythm disruption. And in clinical experiments, we chose a relatively large group of rhythm disturbance-shift nurses. We showed that LL-induced circadian rhythm disruption led to increased body weight and visceral fat volume, as well as occurrence of IR invivo. Furthermore, exosomal miR-22-3p derived from adipocytes in the context of circadian rhythm disruption induced by Bmal1 interference could be uptaken by skeletal muscle cells to promote IR occurrence invitro. Moreover, miR-22-3p in circulation was positively correlated with the clinical IR-associated factors. Collectively, these data showed that exosomal miR-22-3p in circulation may act as potential biomarker and therapeutic target for skeletal muscle IR, contributing to the prevention of diabetes in the context of rhythm disturbance.

The role and expression of pro/antiangiogenic factors and microRNAs in gestational hypertension and pre-eclampsia

ObjectivePre-eclampsia and gestational hypertension are two common hypertensive disorders of pregnancy with pre-eclampsia accounting for high foetal and maternal morbidity and mortality rate. These disorders have an unknown aetiology and their hypertensive and end-organ pathophysiology may present too late in pregnancy. This makes the identification of early detection and differentiation markers vital. MicroRNAs have strongly been associated with pregnancy and their imbalance has been associated with the angiogenic dysregulation seen in pre-eclampsia. This study assesses the expression of pro- and antiangiogenic factors and their corresponding microRNAs in the maternal circulation of patients with pre-eclampsia and gestational hypertension. Study designWe analyzed angiogenic factors expression (sEng, TGF-β, VEGF) normalized against housekeeping gene β-actin and microRNAs (miRs: 210, 29B, 126) normalized against miR U6, potentially associated with pre-eclampsia and gestational hypertension using the targeted qPCR technique. These analytes were examined from early-onset (<34 weeks) (EOPE) (n = 12), late-onset (>34 weeks) (LOPE) (n = 12) pre-eclampsia, gestational hypertension (GH) (n = 12) and two gestationally matched normotensive groups (NG1 and 2) (n = 12) each in South African women of African ancestry. Group comparisons of experimental vs. control groups were assessed using t-test analysis for significance and represented as fold change expression. ResultsThe relative expression in group comparisons showed significant (p < 0.05) fold change of VEGF, TGF-β, sEng and miR126 in the EOPE vs. NG1. The GH vs. NG1 exhibited significant changes in VEGF, TGF-β, miR126, miR210 and miR29B. The LOPE vs. NG2 showed significant relative expression in all the angiogenic factors (VEGF, TGF-β and sEng). The GH vs. NG2 showed significant expression in VEGF and miR29B. The LOPE vs. EOPE showed significant fold changes in VEGF and miR210. Finally, only the GH vs. EOPE showed significant differences in miR210 and miR29B (p < 0.05). ConclusionThis study provides better insights into angiogenic factors and microRNAs specificity to the subtypes of gestational hypertensive disorders in pregnancy. Relative expression analysis of angiogenic factors and microRNAs showed possible novel characteristics of gestational hypertension, and potential common molecular and pathological profiles with pre-eclampsia. Furthermore, we postulate that sEng and miR29B could be early detection markers for pre-eclampsia and gestational hypertension, respectively.

Circulatory miR-411-5p as a Novel Prognostic Biomarker for Major Adverse Cardiovascular Events in Patients with Atrial Fibrillation.

The risk stratification of patients with atrial fibrillation (AF) for subsequent cardiovascular events could help in guiding prevention strategies. In this study, we aimed at investigating circulating microRNAs as prognostic biomarkers for major adverse cardiovascular events (MACE) in AF patients. We conducted a three-stage nested case-control study within the framework of a prospective registry, including 347 AF patients. First, total small RNA-sequencing was performed in 26 patients (13 cases with MACE) and the differential expression of microRNAs was analyzed. Seven candidate microRNAs with promising results in a subgroup analysis on cardiovascular death were selected and measured via using RT-qPCR in 97 patients (42 cases with cardiovascular death). To further validate our findings and investigate broader clinical applicability, we analyzed the same microRNAs in a subsequent nested case-control study of 102 patients (37 cases with early MACE) by using Cox regression. In the microRNA discovery cohort (n = 26), we detected 184 well-expressed microRNAs in circulation without overt differential expression between the cases and controls. A subgroup analysis on cardiovascular death revealed 26 microRNAs that were differentially expressed at a significance level < 0.05 (three of which with an FDR-adjusted p-value <0.05). We, therefore, proceeded with a nested case-control approach (n = 97) focusing on patients with cardiovascular death and selected, in total, seven microRNAs for further RT-qPCR analysis. One microRNA, miR-411-5p, was significantly associated with cardiovascular death (adjusted HR (95% CI): 1.95 (1.04-3.67)). Further validation (n = 102) in patients who developed early MACE showed similar results (adjusted HR (95% CI) 2.35 (1.17-4.73)). In conclusion, circulating miR-411-5p could be a valuable prognostic biomarker for MACE in AF patients.

Circulating microRNAs in gallbladder cancer: Is serum assay of diagnostic value?

The microRNAs (miRNAs) in circulation could serve as biomarkers for cancer detection. Gallbladder carcinoma (GBC) is mostly asymptomatic; therefore, using microRNAs (miRNAs) as an early diagnostic biomarker could be a valuable tool. We aimed to identify the tumor-associated miR-1, miR130, miR-146, miR-182, and miR-21expression in serum as a biomarker for early detection of GBC and identify their possible diagnostic role. The study group comprised of paired serum and tissue samples from 34 GBC, 19 cholecystitis (CC), 21 normal controls (uninflamed gall bladder), and additional 29 serum-only samples of GBC. Total RNA was isolated using a commercially available RNA isolation kit (Applied Biosystem, USA) and reverse transcribed using Advanced Taqman MicroRNA reverse transcription kit. The relative expression of miRNAs was analyzed using Quantitative real-time polymerase chain reaction. The diagnostic potential of these miRNAs was assessed by ROC analysis. In paired samples, the trend towards up and down regulation for miR-182, miR-21, miR-1, miR-130, and miR-146 was similar in both tissue and sera of GBC. The expression pattern of serum miR-1, miR130, and miR-146 gradually decreased from normal control (NC) to CC to GBC, while miR-21 and miR-182 gradually increased from NC to CC to GBC. The miR-1, miR-121, miR-182, and miR-146 significantly differed between CC vs. early stage and early stage vs. NC. Among these miRNAs, the sensitivity of miR-1 (85.71 %) was the highest, and the specificity of miR-21 was the highest (92.73 %). The combined sensitivity for miRNAs ranged from 73.13 % (CI: 60.90-83.24 %) to 98.63 % (CI: 89.0-99.61 %); however, the specificity was lower. In stage I&II vs. III&IV discrimination, the diagnostic sensitivity of miR-1 was highest (89.36 %, CI: 76.90-96.45). The two miRNAs, in combination, increase the diagnostic sensitivity. Circulating serum miRNAs may provide a new approach for clinical application. Panels of specific circulating miRNA, which require further validation, could be potential non-invasive diagnostic biomarkers for GBC in combination with abnormal radio diagnostic scans.

Role of MicroRNAs in Cardiac Disease with Stroke in Pregnancy.

Pregnancy-related cardiovascular disease with stroke remains a considerable source of higher maternal morbidity and mortality occurs in periods of pregnancy, delivery, and postpartum. It is essential to counsel the mother before pregnancy by an expert cardiologist and obstetric team to discuss any event related to preexistent cardiac or past preeclampsia for estimation of maternal and fetal risks. In pregnancy, the cardiac state includes hypertensive disorders, ischemic heart disease, valvular disease, and postpartum stroke. The incidence of stroke is increasing in pregnancy, particularly in postpartum, and its strong relationship with hypertensive disorders of pregnancy (preeclampsia). The combined cardiologist and obstetrics team requires during pregnancy mainly due to the approach to the management of a cardiac disease that subsequently prevents stroke postpartum. Therefore, a general perception of cardiac disease during pregnancy, delivery, and postpartum should be a core knowledge extent for all cardiovascular and clinicians. Many studies provided linked that deregulation of microRNAs (miRNAs) in maternal circulation and placenta tissue may development of pregnancy complications including preeclampsia considered a diagnostic marker. The desire of this review provides a detailed outline of current knowledge and dealing in this field with strength on the physiological changes during pregnancy.

Different expression pattern of human cytomegalovirus-encoded microRNAs in circulation from virus latency to reactivation

BackgroundHuman cytomegalovirus (HCMV) is a beta-hersvirinae that has a high latent infection rate worldwide and can cause serious consequences in immunocompromised patients when reactivation; however, the mechanism of how HCMV convert from latent to reactivation has rarely been investigated. In the present study, we aimed to perform a comprehensive analysis of the HCMV-encoded microRNA (miRNA) profile in serum of patients upon HCMV reactivation from latency and to further evaluate its clinical significance for the disease monitoring and preventing usefulness.MethodsSerum samples from 59 viremia patients and 60 age-gender matched controls were enrolled in this study for screening and validation of different expression of HCMV miRNAs. Serum concentrations of 22 known HCMV miRNAs were determined by a hydrolysis probe-based stem-loop quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay. HCMV DNA was measured by quantitative real-time PCR (qPCR) with the whole blood sample. Serum HCMV IgG and IgM were assessed using enzyme linked immunosorbent assay (ELISA). Another 47 samples from 5 patients at different time points were collected to evaluate the monitoring effectiveness and disease prediction ability of differential expression HCMV-miRNAs during the antiviral treatment.ResultsThe RT-qPCR analysis revealed that the serum levels of 16 of the 22 examined HCMV miRNAs were elevated in HCMV viremia patients compared with controls, and a profile of 8 HCMV miRNAs including hcmv-miR-US25-2-3p, hcmv-miR-US4-5p, hcmv-miR-US25-2-5p, hcmv-miR-US25-1-3p, hcmv-miR-US25-1, hcmv-miR-UL36, hcmv-miR-UL148D, hcmv-miR-US29-3p were markedly elevated (fold change > 2, P < 0.01). Receiver operating characteristic curve (ROC) analysis were performed on the selected HCMV-miRNAs in all of the patients and controls that enrolled in this study, and which ranged from 0.72 to 0.80 in the autoimmune patients. In addition, hcmv-miR-US25-1-3p levels were significantly correlated with HCMV DNA load (r = 0.349, P = 0.007), and were obviously higher in the reactivation set than the latency set in the autoimmune patients, which could be a predictor for the monitoring of the antiviral treatment.ConclusionsHCMV miRNAs profile showed markedly shift-switch from latency to reactivation in circulation from HCMV infected patients and hcmv-miR-US25-1-3p may be served as a predictor for the switch upon reactivation from latency in patients suffered with autoimmune diseases.

Serum microRNA expression profiling revealing potential diagnostic biomarkers for lung adenocarcinoma.

BackgroundRecent studies have demonstrated that microRNAs (miRNAs) in the blood circulation can serve as promising diagnostic markers for cancers. This four-stage study aimed at finding serum miRNAs as potential biomarkers for lung adenocarcinoma (LA) diagnosis.MethodsThe study was carried out between 2016 and 2017. The Exiqon miRNA qPCR panel (3 LA vs. 1 normal control [NC] pooled serum samples) was used for initial screening to acquire miRNA profiles. Thirty-five dysregulated miRNAs were further evaluated in the training (24 LA vs. 24 NCs) and testing stages (110 LA vs. 110 NCs) using quantitative real-time polymerase chain reaction assays.ResultsFour serum miRNAs (miR-133a-3p, miR-584-5p, miR-10b-5p, and miR-221-3p) were significantly overexpressed in LA patients compared with NCs. The diagnostic value of the four-miRNA panel was validated by an external cohort (36 LA vs. 36 NCs). The areas under the receiver operating characteristic curve of the four-miRNA panel in the training, testing, and external validation stages were 0.734, 0.803, and 0.894 respectively. Meanwhile, the expression level of miR-221-3p was much higher in LA tumor samples than that in the adjacent normal tissues (19 LA vs. 19 NCs). The expression level of miR-10b-5p was also elevated in the serum-derived exosomes samples (18 LA vs. 18 NCs). The expression of miR-133a-3p, miR-584-5p, and miR-10b-5p was significantly elevated in LA patients with epidermal growth factor receptor mutation compared with NCs.ConclusionThe study established a four-miRNA signature in serum that could improve the diagnostic capability of LA.

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

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

Expression profile of maternal circulating microRNAs as non-invasive biomarkers for prenatal diagnosis of congenital heart defects

ObjectiveThe discovery of cell free fetal microRNAs (miRNAs) in maternal circulation has opened up novel probabilities for non-invasive prenatal diagnosis. This study aims to investigate circulating miRNAs as potential biomarkers in the serum of pregnant women with congenital heart defect (CHD) fetuses. MethodA total of 110 pregnant women including 50 CHD cases and 60 healthy controls were included in this study. miRNA microarray followed by real-time PCR was used to explore miRNA expression. Receiver operating characteristic (ROC) curves were calculated to assess the diagnostic capability of miRNAs for fetal CHDs. Results38 Serum miRNAs were revealed to be differentially expressed in the CHD group as compared to control group via microarray. Among these, nine down-regulated and three up-regulated miRNAs were validated by real-time PCR. Ten of these miRNAs were rapidly reduced in the normal maternal serum after delivery as compared to before delivery. In particular, we identified a biomarker panel consisting of four miRNAs (miR-142-5p, miR-1275, miR-4666a-3p and miR-3664-3p) capable of distinguishing CHDs from controls (area under the ROC curve (AUC), 0.920; p < 0.0001). ConclusionThe discovery of these dysregulated pregnancy-associated miRNAs in maternal serum may be potential biomarkers for non-invasive prenatal diagnosis of fetal CHDs.

291. MicroRNAs in maternal circulation as predictors of preeclampsia at term

Introduction MicroRNAs (miRs) are small RNA molecules involved in the negative regulation of genes, that are highly stable within the circulation. The FLAG study is a prospective collection of over 2000 maternal blood samples at 28 and 36 weeks gestation. 3.9% of FLAG patients developed preeclampsia(PE) after 36 weeks. Objectives/Hypothesis We hypothesise that circulating miRs will be dysregulated in the blood of women preceding diagnosis of PE. Our objective was to screen women at 36 weeks gestation to identify potential biomarkers of PE. Methods A panel of 41 miRs were selected for analysis: 32 were from the placental-specific C19MC cluster and 9 identified as previously associated with PE. A case-control group was selected from the FLAG cohort comprising n = 196 controls and n = 34 patients destined to develop PE. Whole blood RNA was extracted using PAXgene tubes and a custom qRT-PCR microarray containing 41 miRs and 3 housekeepers used to measure miRs at 36 weeks. Results At 36 weeks gestation, miRs 18a, 1283, 16, 149, 363 and 424 were significantly decreased in mothers destined to develop PE (p Discussion Whilst the combined sensitivity of miR149 and 363 is low, the reasonable NPV highlights these miRs as potential contributors to a multi-analyte rule-out test at term which could save valuable time and resources. Moreover, these miRs hold potential for the prediction of PE at earlier gestations (if combined with other analytes), a consideration which will be the focus of future work.

TCTAP A-040 Endothelial Microparticles-mediated Transfer of MicroRNA-19b Promotes Atherosclerosis via Activating Perivascular Adipose Tissue Inflammation in ApoE-/- Mice

Microparticles are the major carriers of microRNAs in circulation. Our previous study has shown that microRNA (miR)-19b in endothelial microparticles (EMP) is significantly elevated in patients with unstable angina. However, little is known about the relationship between EMP mediated miR-19b

Extracellular Vesicle Biology in the Pathogenesis of Lung Disease.

Abstract As our understanding of diseases of the lung continues to evolve, we recognize that the mechanisms that drive cell/environment communication leading to disease development and progression are complex. In 2008, investigators first identified intact cell free microRNAs in circulation with some localized within lipid-encapsulated microvesicles termed extracellular vesicles (EVs). Prior to and following this discovery, investigators have determined that EVs may drive biological processes fundamental to human disease and homeostasis. The cargo in EVs which includes, proteins, miRNAs and mRNAs is protected from degradation, often reflects the pathogenesis of the cell of origin and may serve as a conduit for communication between cells subsequently reprogramming recipient cell function. Furthermore, EVs have been detected in bodily fluids including blood urine, sputum and bronchoalveolar lavage. The release and shuttling of EVs between cells following both environmental exposure and during disease development and progression has added a new layer of complexity to cell-cell communication in lung disease. While the majority of studies implicating EVs in human biology have been conducted in cancer, we have witnessed an emergence of EV based studies in other physiopathological conditions. EV mediated transfer of genetic content may link environmental stressors to the lung immune response through intercellular communication within the lung and development of disease. This perspective will focus on the growing field of EV biology in human lung diseases and its application to both the development and progression of lung disease and in biomarker discovery.

Circulating micro-RNAs as biomarkers of coronary artery disease: is it ready for primetime or still a work in progress?

MicroRNAs (miRs) are small non-coding RNAs that play a significant role in epigenetic regulation of gene expression (1,2). Several miRs have been established to play crucial roles in a spectrum of different cardiovascular diseases (3,4). Since the initial identification of detectable levels of circulating miRs in plasma (5-7), circulating miRs have become the spotlight of investigation as potential biomarkers for several diseases. Micro-RNAs in circulation have two important features of ideal biomarkers: they are remarkably stable and safe from degradation by RNases, and they are easily measured in the circulation using sensitive and specific quantitative PCR techniques. Thus, circulating miRs can be linked to specific disease processes or to specific tissue and/or cell types.

Abstract 537: Lipoproteins Transport Functional Non-human Small RNAs that Regulate Gene Networks Spanning Inflammation and Lipid Metabolism

Cardiovascular disease (CVD) is a significant health and financial burden to our society that demands new and more effective therapies. Although dyslipidemias are primary risk factors for CVD, alternative lipoprotein functions also contribute to CVD and warrant greater understanding. We have found that high-density lipoproteins (HDL) transport microRNAs (miRNA) in circulation and HDL-miRNA signatures are significantly altered in hypercholesterolemia and atherosclerosis. Moreover, we found that HDL transfers extracellular miRNAs to recipient cells where they regulate gene expression through post-transcriptional repression of mRNA targets. We used high-throughput small RNA (sRNA) sequencing to identify and quantify miRNAs and novel sRNAs on HDL and other lipoproteins. Most interestingly, we found that the majority of sRNAs on lipoproteins are likely derived from non-human organisms of multiple kingdoms. Based on these observations, we hypothesized that human and non-human sRNAs on lipoproteins are unique regulators of gene networks that contribute to the complex pathophysiology of CVD. To assess this hypothesis, highly pure lipoproteins (HDL, low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL)) were isolated from plasma of hypercholesterolemic (heterozygous familial hypercholesterolemia, n=9) and healthy (n=7) subjects. We found that HDL, LDL, and VLDL each transport unique sRNA signatures, which are differentially altered in hypercholesterolemic subjects. Using a human tissue library, we identified tissues that likely take up non-human sRNAs. We also found that each class of lipoprotein is capable of transferring non-human sRNAs to multiple cell types, and that transfer efficiency is altered in hypercholesterolemia. Lastly, using a combination of in vitro over-expression and locked-nucleic-acid inhibition for candidate, lipoprotein-enriched, non-human sRNAs, we have discovered novel regulatory networks for critical genes in inflammation and lipid metabolism. This work demonstrates that lipoprotein transport of endogenous and exogenous sRNAs likely have complex roles in the progression and resolution of CVD and are a source of untapped potential for nucleic-acid based therapeutics.

Non-coding RNAs in Exosomes: New Players in Cancer Biology

Exosomes are lipid bilayer extracellular vesicles (EVs) of 50-150nm in size, which contain nucleic acids (mRNA, ncRNAs and DNA), proteins and lipids. They are secreted by all cells and circulate in all body fluids. Exosomes are key mediators of several processes in cancer that mediate tumor progression and metastasis. These nano-vesicles, when secreted from cancer cells, are enriched in non-coding RNAs (e.g. microRNAs) complexed with the RNA-Induced Silencing Complex (RISC), that mediate an efficient and rapid silencing of mRNAs at the recipient cell, reprogramming their transcriptome. MicroRNAs in circulation encapsulated in exosomes are protected from degradation by a lipid bilayer and might serve as potential non-invasive diagnostic and screening tools to detect early stage cancer, to facilitate treatment options and possible help in curative surgical therapy decisions. Additionally, engineered exosomes can be used as therapy vehicles for targeted delivery of RNAi molecules, escaping the immune system detection.

Abundant circulating microRNAs in breast cancer patients fluctuate considerably during neoadjuvant chemotherapy.

Previous studies have revealed the aberrant expression of a number of microRNAs (miRNA/miRs) in the blood circulation of patients with breast cancer (BC). The aim of the present study was to assess the effect of neoadjuvant chemotherapy on the levels of a panel of BC-associated miRNAs, which are at relatively low (let-7, miR-10b, miR-34, miR-155, miR-200c and miR-205) or abundant (miR-21, miR-195 and miR-221) levels in the circulation. Patients with primary operable or locally advanced BC were enrolled in the study. The plasma levels of the miRNAs at baseline and at the fourth cycle of treatment were compared. Patients with stage II disease exhibited higher basal miRNAs levels than those with higher stages. The difference was most evident for miR-155 and miR-21 (P=0.05). From the initial to the fourth cycle of chemotherapy, the miRNA levels changed substantially. In samples in which the miRNA levels generally declined, a marked decrease (≤15,500-fold) was evident for the abundant miRNAs. Notably, the occurrence of a decrease in miRNA levels was more frequent in patients with smaller tumor sizes (P<0.05 for miR-21 and miR-195). This proof-of-concept study provides evidence that highly expressed miRNAs are affected most frequently by chemotherapy, particularly in patients with early stage tumors. This information may be valuable in assessing the response of the patients to therapy.

MicroRNAs in Circulation Are Altered in Response to Influenza A Virus Infection in Humans

Changes in microRNA expression have been detected in vitro in influenza infected cells, yet little is known about them in patients. microRNA profiling was performed on whole blood of H1N1 patients to identify signature microRNAs to better understand the gene regulation involved and possibly improve diagnosis. Total RNA extracted from blood samples of influenza infected patients and healthy controls were subjected to microRNA microarray. Expression profiles of circulating microRNAs were altered and distinctly different in influenza patients. Expression of highly dysregulated microRNAs were validated using quantitative PCR. Fourteen highly dysregulated miRNAs, identified from the blood of influenza infected patients, provided a clear distinction between infected and healthy individuals. Of these, expression of miR-1260, -26a, -335*, -576-3p, -628-3p and -664 were consistently dysregulated in both whole blood and H1N1 infected cells. Potential host and viral gene targets were identified and the impact of microRNA dysregulation on the host proteome was studied. Consequences of their altered expression were extrapolated to changes in the host proteome expression. These highly dysregulated microRNAs may have crucial roles in influenza pathogenesis and are potential biomarkers of influenza.

OP34.01: Extracellular chromosome 21: derived microRNAs in maternal circulation: evaluation of their diagnostic potential for screening of Down syndrome

OP34.01: Extracellular chromosome 21: derived microRNAs in maternal circulation: evaluation of their diagnostic potential for screening of Down syndrome