Epigenetics is believed to play a role in Alzheimer's disease (AD). DNA methylation, the most investigated epigenetic hallmark, is a reversible mechanism that modifies genome function and chromosomal stability through the addition of methyl groups to cytosine located in CpG dinucleotides to form 5 methylcytosine (5mC). Methylation status of repetitive elements (i.e. Alu, LINE-1 and SAT- α) is a major contributor of global DNA methylation patterns and has been investigated in relation to a variety of human diseases. However, the role of methylation of repetitive elements in blood of AD patients has never been investigated so far. In the present study, a quantitative bisulfite-PCR pyrosequencing method was used to evaluate methylation of Alu, LINE-1 and SAT- α sequences in 43 AD patients and 38 healthy donors. In multivariate analysis adjusting for age and gender, LINE-1 was increased in AD patients compared with healthy volunteers (ADs: 83.6 %5mC, Volunteers: 83.1 %5mC, p-value: 0.05). The group with best performances in mini mental state examination (MMSE) showed higher levels of LINE-1 methylation compared to the group with worst performances (MMSE>22: 83.9 %5mC; MMSE<=22: 83.2 %5mC; p=0.05). Our data suggest that LINE-1 methylation may lead to a better understanding of AD pathogenesis and course, and may contribute to identify novel markers useful to assess risk stratification. Further prospective investigations are warranted to evaluate the dynamics of DNA methylation from early-stage AD to advanced phases of the disease.

No abstract

BackgroundExposure to particulate matter (PM) is associated with increased incidence of cardiovascular disease and increased coagulation, but the molecular mechanisms underlying these associations remain unknown. Obesity may increase susceptibility to the adverse effects of PM exposure, exacerbating the effects on cardiovascular diseases. Extracellular vesicles (EVs), which travel in body fluids and transfer microRNAs (miRNAs) between tissues, might play an important role in PM-induced cardiovascular risk. We sought to determine whether the levels of PM with an aerodynamic diameter ≤ 10 μm (PM10) are associated with changes in fibrinogen levels, EV release, and the miRNA content of EVs (EV-miRNAs), investigating 1630 overweight/obese subjects from the SPHERE Study.ResultsShort-term exposure to PM10 (Day before blood drawing) was associated with an increased release of EVs quantified by nanoparticle tracking analysis, especially EVs derived from monocyte/macrophage components (CD14+) and platelets (CD61+) which were characterized by flow cytometry. We first profiled miRNAs of 883 subjects by the QuantStudio™ 12 K Flex Real Time PCR System and the top 40 EV-miRNAs were validated through custom miRNA plates. Nine EV-miRNAs (let-7c-5p; miR-106a-5p; miR-143-3p; miR-185-5p; miR-218-5p; miR-331-3p; miR-642-5p; miR-652-3p; miR-99b-5p) were downregulated in response to PM10 exposure and exhibited putative roles in cardiovascular disease, as highlighted by integrated network analysis. PM10 exposure was significantly associated with elevated fibrinogen levels, and five of the nine downregulated EV-miRNAs were mediators between PM10 exposure and fibrinogen levels.ConclusionsResearch on EVs opens a new path to the investigation of the adverse health effects of air pollution exposure. EVs have the potential to act both as markers of PM susceptibility and as potential molecular mechanism in the chain of events connecting PM exposure to increased coagulation, which is frequently linked to exposure and CVD development.Electronic supplementary materialThe online version of this article (doi:10.1186/s12989-017-0214-4) contains supplementary material, which is available to authorized users.

Background. Exercise is recognized to evoke multisystemic adaptations that, particularly in obese subjects, reduce body weight, improve gluco-metabolic control, counteract sarcopenia and lower the risk of cardiometabolic diseases. Understanding the molecular and cellular mechanisms of exercise-induced benefits is of great interest due to the therapeutic implications against obesity.Objectives and methods. The aim of the present study was to evaluate time-related changes in size distribution and cell origin of extracellular vesicles (EVs) in obese and normal-weight subjects who underwent a moderate-intensity exercise on a treadmill (at 60% of their VO2max). Blood samples were drawn before, immediately at the end of the exercise and during the post-exercise recovery period (3h and 24h). Circulating EVs were analyzed by a nanoparticle tracking analysis and flow cytometry after labeling with the following cellspecific markers: CD14 (monocyte/macrophage), CD61 (platelet), CD62E (activated endothelium), CD105 (total endothelium), SCGA (skeletal muscle) and FABP (adipose tissue).Results. In all subjects, acute exercise reduced the release of total (i.e., 30-700 nm) EVs in circulation, predominantly EVs in the microvesicle size range (i.e., 130-700 nm EVs). The post-exercise release of microvesicles was higher in normal-weight than obese subjects; after exercise, circulating levels of exosomes (i.e., 30-130 nm EVs) and microvesicles were, respectively, lower and higher in females than males. In all experimental subgroups (males vs. females and obese vs. normal-weight subjects), acute exercise reduced and increased, respectively, CD61+ and SCGA+ EVs, being the effect on CD61+ EVs prolonged up to 24h after the end of the test with subjects in resting conditions. Total EVs, exosomes and CD61+ EVs were associated with HOMA-IR.Conclusions. Though preliminary, the results of the present study show that a single bout of acute exercise modulates the release of EVs in circulation, which are tissue-, sex-and BMI specific, suggesting that the exercise-related benefits might depend upon a complex interaction of tissue, endocrine, and metabolic factors.

Cardiovascular disease risk has been consistently linked with particulate matter (PM) exposure. Cell-derived microvesicles (MVs) are released into plasma and transfer microRNAs (miRNAs) between tissues. MVs can be produced by the respiratory system in response to proinflammatory triggers, enter the circulatory system and remotely modify gene expression in cardiovascular tissues. However, whether PM affects MV signaling has never been investigated. In this study, we evaluated expression of microRNAs contained within plasma MVs upon PM exposure both in vivo and in vitro. In the in vivo study, we isolated plasma MVs from healthy steel plant workers before and after workplace PM exposure. We measured the expression of 88 MV-associated miRNAs by real-time polymerase chain reaction. To assess a possible source of the MV miRNAs identified in vivo, we measured their miRNA expression in PM-treated A549 pulmonary cell lines in vitro. MiRNA profiling of plasma MVs showed 5.62- and 13.95-fold increased expression of miR-128 and miR-302c, respectively, after 3 days of workplace PM exposure (P < 0.001). According to Ingenuity Pathway Analysis, miR-128 is part of coronary artery disease pathways, and miR-302c is part of coronary artery disease, cardiac hypertrophy and heart failure pathways. In vitro experiments confirmed a dose-dependent expression of miR-128 in MVs released from A549 cells after 6 h of PM treatment (P = 0.030). MiR-302c was expressed neither from A549 cells nor in reference lung RNA. These results suggest novel PM-activated molecular mechanisms that may mediate the effects of air pollution and could lead to the identification of new diagnostic and therapeutic interventions. Copyright © 2014 The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd.Cell-derived microvesicles (MVs) are found in plasma and may transfer signals between tissues. In this article, we report in-vivo and in-vitro studies demonstrating that Particulate Matter (PM) affects systemic MV signaling by inducing MV release from alveolar cells into plasma. In-vivo microRNA screening showed increased miR-128 level in plasma MVs after PM exposure. In-vitro experiments confirmed PM-induced release of miR-128 in MVs from A549 alveolar cells. Future studies are warranted to determine the roles of MVs in mediating PM effects.

BackgroundDespite epidemiological findings showing increased air pollution related cardiovascular diseases (CVD), the knowledge of the involved molecular mechanisms remains moderate or weak. Particulate matter (PM) produces a local strong inflammatory reaction in the pulmonary environment but there is no final evidence that PM physically enters and deposits in blood vessels. Extracellular vesicles (EVs) and their miRNA cargo might be the ideal candidate to mediate the effects of PM, since they could be potentially produced by the respiratory system, reach the systemic circulation and lead to the development of cardiovascular effects.The SPHERE (“Susceptibility to Particle Health Effects, miRNAs and Exosomes”) project was granted by ERC-2011-StG 282413, to examine possible molecular mechanisms underlying the effects of PM exposure in relation to health outcomes.Methods/designThe study population will include 2000 overweight (25 < BMI < 30 kg/cm2) or obese (BMI ≥ 30 kg/cm2) subjects presenting at the Center for Obesity and Work (Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy).Each subject donates blood, urine and hair samples. Extensive epidemiological and clinical data are collected. Exposure to PM is assigned to each subject using both daily PM10 concentration series from air quality monitors and pollutant levels estimated by the FARM (Flexible air Quality Regional Model) modelling system and elaborated by the Regional Environmental Protection Agency.The recruitment period started in September 2010 and will continue until 2015. At December 31, 2013 we recruited 1250 subjects, of whom 87% lived in the province of Milan.Primary study outcomes include cardiometabolic and respiratory health effects. The main molecular mechanism we are investigating focuses on EV-associated microRNAs.DiscussionSPHERE is the first large study aimed to explore EVs as a novel potential mechanism of how air pollution exposure acts in a highly susceptible population. The rigorous study design, the availability of banked biological samples and the potential to integrate epidemiological, clinical and molecular data will also furnish a powerful base for investigating different complementary molecular mechanisms. Our findings, if confirmed, could lead to the identification of potentially reversible alterations that might be considered as possible targets for new diagnostic and therapeutic interventions.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2458-14-1137) contains supplementary material, which is available to authorized users.

No abstract

The study's findings support the hypothesis that adverse cardiovascular and metabolic effects stemming from inhalation exposures in particular to PM metallic component may be mediated by EVmiRNAs that target key factors in the inflammation, coagulation and glucose homeostasis pathways.