Simona Iodice

Effect of Fenretinide and Low-Dose Tamoxifen on Insulin Sensitivity in Premenopausal Women at High Risk for Breast Cancer

The prevalence of metabolic syndrome is increasing along with breast cancer incidence worldwide. Because fenretinide improves insulin action and glucose tolerance in insulin-resistant obese mice and because tamoxifen has shown to regulate several markers involved in metabolic syndrome, we sought to investigate the effect of fenretinide or tamoxifen at low dose on features linked to insulin resistance in premenopausal women at risk for breast cancer. We randomized 235 women to low-dose tamoxifen (5 mg/daily), fenretinide (200 mg/daily), or their combination or placebo for 2 years. We used the homeostasis model assessment (HOMA; fasting insulin x glucose/22.5) to estimate insulin sensitivity. Women were considered to improve insulin sensitivity when they shifted from a HOMA >/=2.8 to <2.8. There was no effect of fenretinide or tamoxifen on HOMA overall, but overweight women (body mass index, >or=25 kg/m(2)) had a 7-fold greater probability to normalize HOMA after 2 years of fenretinide treatment [odds ratio (OR), 7.0; 95% confidence interval (95% CI), 1.2-40.5], with 25% of women improving their insulin sensitivity, whereas tamoxifen decreased insulin sensitivity by almost 7 times compared with subjects not taking tamoxifen (OR, 0.15; 95% CI, 0.03-0.88). In this group only, 5% improved their insulin sensitivity. Interestingly, women with intraepithelial or microinvasive neoplasia had higher HOMA (3.0) than unaffected subjects (2.8; P = 0.07). Fenretinide can positively balance the metabolic profile in overweight premenopausal women and this may favorably affect breast cancer risk. Furthermore, features of the metabolic syndrome should be taken into consideration before proposing tamoxifen for breast cancer prevention. The clinical implications of these results require further investigations.

Particulate matter exposure is associated with inflammatory gene methylation in obese subjects

Background Overweight and obesity are becoming more widespread with alarming projections for the coming years. Obesity may increase susceptibility to the adverse effects of PM exposure, exacerbating the effects on cardiovascular diseases and altering the biomarkers of vascular inflammation. The associated biological mechanisms have not been fully understood yet; the common denominator in the pathogenesis of the co‐morbidities of obesity is the presence of an active, low‐grade inflammatory process. DNA methylation has been shown to regulate inflammatory pathways that are responsible for the development of cardiovascular diseases. Objectives The aim of the study was to investigate, in a population of overweight/obese subjects, the effects of PM on blood DNA methylation in genes associated to inflammatory response. Methods Using bisulfite pyrosequencing, we measured DNA methylation in peripheral blood mononuclear cells from 186 overweighted/obese subjects. In particular, we quantified DNA methylation in a set of 3 candidate genes, including CD14, TLR4 and TNF‐&agr;, because of the important roles that these genes play in the inflammatory pathway. Personal exposure to PM10 was estimated for each subject based on the local PM10 concentrations, measured by monitoring stations at residential address. Repeated measure models were used to evaluate the association of PM10 with each genes, accounting for possible correlations among the genes that regulate the same inflammatory pathway. Results We found an inverse association between the daily PM10 exposure and the DNA methylation of inflammatory genes, measured in peripheral blood of healthy overweight/obese subjects. Considering different exposure time‐windows, the effect on CD14 and TLR4 methylation was observed, respectively, in days 4–5‐6, and days 6–7‐8. TNF‐&agr; methylation was not associated to PM10. Conclusions Our findings support a picture in which PM10 exposure and transcriptional regulation of inflammatory gene pathway in obese subjects are associated. HighlightsOverweight/obese subjects has been proposed as susceptible population for PM related effects.DNA methylation is a key molecular mechanisms linking PM exposure to systemic pro‐inflammatory effectsPM10 exposure resulted associated to DNA methylation of inflammatory genes in a population of obese patients.The relationship between PM10 and DNA methylation of inflammation pathway‐genes was confirmed in obese subjects.

MicroRNAs are associated with blood-pressure effects of exposure to particulate matter: Results from a mediated moderation analysis.

Aims Exposure to particulate air pollution is associated with increased blood pressure (BP), a well-established risk factor for cardiovascular disease. To elucidate the mechanisms underlying this relationship, we investigated whether the effects of particulate matter of less than 10 μm in aerodynamic diameter (PM10) on BP are mediated by microRNAs. Methods and results We recruited 90 obese individuals and we assessed their PM10 exposure 24 and 48 h before the recruitment day. We performed multivariate linear regression models to investigate the effects of PM10 on BP. Using the TaqMan® Low-Density Array, we experimentally evaluated and technically validated the expression levels of 377 human miRNAs in peripheral blood. We developed a mediated moderation analysis to estimate the proportion of PM10 effects on BP that was mediated by miRNA expression. PM10 exposure 24 and 48 h before the recruitment day was associated with increased systolic BP (β=1.22 mmHg, P=0.019; β=1.24 mmHg, P=0.019, respectively) and diastolic BP (β=0.67 mmHg, P=0.044; β=0.91 mmHg, P=0.007, respectively). We identified nine miRNAs associated with PM10 levels 48 h after exposure. A conditional indirect effect (CIE=−0.1431) of PM10 on diastolic BP, which was mediated by microRNA-101, was found in individuals with lower values of mean body mass index. Conclusions Our data provide evidence that miRNAs are a molecular mechanism underlying the BP-related effects of air pollution exposure, and indicate miR-101 as epigenetic mechanism to be further investigated.

Epigenetics applied to epidemiology: investigating environmental factors and lifestyle influence on human health

Epigenetics modifications, that include variations in DNA methylation, histone acetylation and micro RNA (miRNA) expression, co-operate together, influencing genome expression and function, in response to exogenous stimuli or exposures. Thus, epigenetic tools applied to epidemiology are useful in investigating, at the population level, the relationships between exposures to environmental, lifestyle, genetic, socioeconomic risk factors, and the epigenome, and/or specific health outcomes. But the choice of an appropriate study design and of valid epidemiological methods has a key role in determining the achievement of the study. This review summarises available evidence about the role of the most investigated epigenetic mechanisms in mediating lifestyle or environmental exposure effects on human health, considering the entire life-course, from in-utero to adulthood. Moreover, we illustrate the most important variables that should be properly considered when designing an epigenetic epidemiology study: the choice of an appropriate study design, a proper estimation of the required sample size, a correct biological sample selection, a validation strategy for epigenetics data, and an integrated exposure assessment methodology.

Effects of metal-rich particulate matter exposure on exogenous and endogenous viral sequence methylation in healthy steel-workers

Background: Inhaled particles have been shown to produce systemic changes in DNA methylation. Global hypomethylation has been associated to viral sequence reactivation, possibly linked to the activation of pro‐inflammatory pathways occurring after exposure. This observation provides a rationale to investigate viral sequence (both exogenous and endogenous) methylation in association to metal‐rich particulate matter exposure. To verify this hypothesis, we chose the Wp promoter of the Epstein‐Barr Virus (EBV‐Wp) and the promoter of the human‐endogenous‐retrovirus w (HERV‐w), respectively as a paradigm of an exogenous and an endogenous retroviral sequence, to be investigated by bisulfite PCR Pyrosequencing. We enrolled 63 male workers in an electric furnace steel plant, exposed to high level of metal‐rich particulate matter. Results: Comparing samples obtained in the first day of a work week (time 0‐baseline, after 2 days off work) and the samples obtained after 3 days of work (time 1‐post exposure), the mean methylation of EBV‐Wp was significantly higher at baseline compared to post‐exposure (meanbaseline = 56.7%5mC; meanpost‐exposure = 47.9%5mC; p‐value = 0.009), whereas the mean methylation of HERV‐w did not significantly differ. Individual exposure to inhalable particles and metals was estimated based on measures in all working areas and time spent by the study subjects in each area. In a regression model adjusted for age, body mass index and smoking, PM and metal components had a positive association with EBV‐Wp methylation (i.e. PM10: &bgr; = 5.99, p‐value < 0.038; nickel: &bgr; = 17.82, p‐value = 0.02; arsenic: &bgr; = 13.59, p‐value < 0.015). Conclusions: The difference observed comparing baseline and post‐exposure samples may be suggestive of a rapid change in EBV methylation induced by air particles, while correlation between EBV methylation and PM/metal exposure may represent a more stable adaptive mechanism. Future studies investigating a larger panel of viral sequences could better elucidate possible mechanisms and their role in pro‐inflammatory pathways leading to systemic health effects. HighlightsWe evaluated EBV‐Wp and HERV‐w methylation in 63 male steel plant healthy workers.Metal‐rich particulate matter exposure modifies viral sequence methylation.Changes in viral methylation might alter systemic inflammation.

Urinary chromium is associated with changes in leukocyte miRNA expression in obese subjects

Background/Objectives:Epidemiological studies suggest a link between chromium (Cr) status and cardiovascular disease. Increased urinary excretion of Cr was reported in subjects with diabetes compared with non-diabetic controls and those with non-diabetic insulin resistance. Epigenetic alterations have been linked to the presence of Cr, and microRNA (miRNA) expression has been implicated in the pathogenesis of metabolic diseases and cardiovascular diseases (CVDs). We investigated the association between Cr excretion and miRNA expression in leukocytes from obese subjects. We also examined the relationship between altered miRNA expression and selected clinical parameters to further investigate mechanisms linking Cr to metabolic diseases and CVDs.Subjects/Methods:We analyzed urinary Cr in 90 Italian subjects using inductively coupled plasma-mass spectrometry. Peripheral blood miRNA levels were screened with TaqMan Low-Density Array Human MicroRNA A. Cr level-associated expression of miRNAs was detected with multivariate regression analyses, and the top 10 candidate miRNAs were selected for validation. We also used multivariate regression analyses to assess possible associations between validated miRNAs and glycated hemoglobin (A1c) and blood pressure (BP). The validated miRNAs were further investigated by functional analysis with Ingenuity Pathway Analysis software.Results:Urinary Cr levels (mean: 0.35 μg/l; s.d.=0.24) ranged from 0.05 to 1.27 μg/l. In the screening phase, 43 miRNAs were negatively associated with Cr. Of the top 10 miRNAs selected for validation, nine (miR-451, miR-301, miR-15b, miR-21, miR-26a, miR-362-3p, miR-182, miR-183 and miR-486-3p) were downregulated in association with Cr (P-false discovery rate (FDR)<0.10). miR-451 expression was associated with A1c (β=–0.06; P=0.0416), whereas miR-486-3p expression was associated both with diastolic (β=2.1; P=0.004) and systolic BP (β=3.3; P=0.003).Conclusions:These results indicate that miR-451 and miR-486-3p are involved in the link between Cr levels and metabolic diseases and CVDs.

1281 Mirnas in extracellular vesiclesmediate the effect of particulate matter exposure on coagulation in a large sample of overweight/obese adults

Introduction In Italy about 45% of people aged ≥18 years are overweight/obese and might thus be more susceptible to the adverse health effects of air pollution exposure. Particulate matter ≤10 µm (PM10) represents a common pollutant of living and working environments and has been associated with increased risk of cardiovascular diseases (CVD) and hypercoagulability. Extracellular vesicles (EV) might play an important role in PM-related CVD, as they can travel in body fluids and transfer miRNAs between cells. We investigated whether PM10 exposure is associated with changes in fibrinogen levels, EV release, and EV-miRNA content in a large sample of overweight/obese adults. Methods EV concentrations were quantified by nanoparticle tracking analysis and flow cytometry. To identify altered levels of EV-miRNAs, we profiled miRNAs of 883 subjects by the QuantStudio 12K Flex Real Time PCR System. The top 40 EV-miRNAs were validated through custom miRNA plates. Statistical analyses included multiple linear regressions, mediation analysis and bioinformatics analysis. Results In a sample of 1630 overweight/obese subjects from the SPHERE ( S usceptibility to P article H ealth E ffects, mi R NAs and E xosomes) study, short-term exposure to PM10 was associated with increased release of EVs, especially those from monocyte/macrophage components (CD14+) and platelets (CD61+). Nine EV-miRNAs (let-7c-5p; miR-106a-5p; miR-143–3 p; miR-185–5 p; miR-218–5 p; miR-331–3 p; miR-642–5 p; miR-652–3 p; miR-99b-5p) were downregulated in response to PM10 exposure and exhibited putative roles in CVD. Five of these nine EV-miRNAs were mediators in the positive association between PM10 exposure and fibrinogen levels. Conclusions Our study sheds some light on the potential mechanisms underlying the adverse cardiovascular health effects of air pollution exposure. Our results were obtained in a hypersusceptible population and thus strengthen the relevance of health promotion interventions for both the general public and the working population, as they might be particularly feasible in the workplace.

Cumulative Mass and NIOSH Variable Lifting Index Method for Risk Assessment: Possible Relations

Objective The aim of this study was to explore whether the Variable Lifting Index (VLI) can be corrected for cumulative mass and thus test its efficacy in predicting the risk of low-back pain (LBP). Background A validation study of the VLI method was published in this journal reporting promising results. Although several studies highlighted a positive correlation between cumulative load and LBP, cumulative mass has never been considered in any of the studies investigating the relationship between manual material handling and LBP. Method Both VLI and cumulative mass were calculated for 2,374 exposed subjects using a systematic approach. Due to high variability of cumulative mass values, a stratification within VLI categories was employed. Dummy variables (1–4) were assigned to each class and used as a multiplier factor for the VLI, resulting in a new index (VLI_CMM). Data on LBP were collected by occupational physicians at the study sites. Logistic regression was used to estimate the risk of acute LBP within levels of risk exposure when compared with a control group formed by 1,028 unexposed subjects. Results Data showed greatly variable values of cumulative mass across all VLI classes. The potential effect of cumulative mass on damage emerged as not significant (p value = .6526). Conclusion When comparing VLI_CMM with raw VLI, the former failed to prove itself as a better predictor of LBP risk. Application To recognize cumulative mass as a modifier, especially for lumbar degenerative spine diseases, authors of future studies should investigate potential association between the VLI and other damage variables.

Is there a link between air pollution and mental disorders

Several studies have demonstrated the association between air pollution and different medical conditions including respiratory and cardiovascular diseases. Air pollutants might have a role also in the etiology of mental disorders in the light of their toxicity on central nervous system. Purpose of the present manuscript was to review and summarize available data about an association between psychiatric disorders and air pollution. A research in the main database sources has been conducted to identify relevant papers about the topic. Different air pollutants and in particular PM and nitric oxides have been associated with poor mental health; long exposition to PM2.5 has been associated with an increased risk of new onset of depressive symptoms (Cohens effect size d: 0.05-0.81), while increased concentration of nitric dioxide in summer with worsening of existing depressive conditions (Cohens effect size d: 0.05-1.77). However, the interpretation of these finding should take into account the retrospective design of most of studies, different periods of observations, confounding factors such as advanced age or medical comorbidity. Further studies with rigorous methodology are needed to confirm the results of available literature about this topic.

O18-2 Extracellular vesicles are associated with particulate matter exposure

Background Exposure to Particulate Matter (PM) has been associated with increased risk for cardiovascular diseases. In the lungs PM triggers the release of extracellular vesicles (EVs) that travel through the bloodstream and reach target organs. EVs might represent an essential component of the effect of PM on human health. Aim to characterise plasma EVs and assess their association with exposure to PM with diameter ≤10 µm (PM10) and ≤2.5 µm (PM2.5), considering the role of Body Mass Index (BMI). Methods we recruited 20 male and 30 female healthy volunteers (Nov 2014–Mar 2015) in Milan, Italy, which provided personal information and a blood sample. After centrifugation, EV membrane determinants were characterised by Flow Cytometry (to assess cellular origin from platelets, monocytes, epithelium, endothelium, neutrophils), EV size and counted by Nanosight. Each subject wore a personal air sampler for 24 h, retrieving individual daily mean PM10 and PM2.5 concentrations. Same-day PM10 and PM2.5 data from air quality monitoring stations were also obtained. Associations between PM and log-EV were assessed applying multivariate linear models adjusted for age, sex, BMI and smoking. Results Personal sampler and monitor data showed a Spearman’s ρ of 0.59 (p < 0.001) for PM10 and of 0.68 (p < 0.001) for PM2.5. Regression analysis showed a variation of 10.5% (95% Confidence Interval [CI]: 1.8; 19.8, p = 0.018) in endothelium-derived EV count (CD105+) per 10 µg/m3 increase in PM10, and of 11.4% (95% CI: 2.0; 21.6, p = 0.017) per an equal increase in PM2.5. When stratifying by BMI, all EV types showed a positive increase in overweight subjects only (BMI ≥ 25) and a null-negative variation in normal weight subjects. Variation in EV-CD105+ was 13.4% (95% CI: 3.3; 24.4, p = 0.011) for PM10 and 14.0% (95% CI: 2.6; 26.7, p = 0.018) for PM2.5 in overweight. Conclusions Our findings suggest an association between PM exposure and EV, particularly in hypersusceptible subjects.