PM2 .5, PM10 and bronchiolitis severity: A cohort study.

BACKGROUND: A few studies suggest that particulate matter (PM) exposure might play a role in bronchiolitis. However, available data are mostly focused on the risk of hospitalization and come from retrospective studies that provided conflicting results. This prospective study investigated the association between PM (PM2.5 and PM10 ) exposure and the severity of bronchiolitis. METHODS: This prospective cohort study was conducted between November 2019 and February 2020 at the pediatric emergency department of the Fondazione IRCCS Ca' Ospedale Maggiore Policlinico, Milan, Italy. Infants <1 year of age with bronchiolitis were eligible. The bronchiolitis severity score was assessed in each infant and a nasal swab was collected to detect respiratory viruses. The daily PM10 and PM2.5 exposure in the 29 preceding days were considered. Adjusted regression models were employed to evaluate the association between the severity score and PM10 and PM2.5 exposure. RESULTS: A positive association between the PM2.5 levels and the severity score was found at day-2 (ß 0.0214, 95% CI 0.0011-0.0417, p = .0386), day-5 (ß 0.0313, 95% CI 0.0054-0.0572, p = .0179), day-14 (ß 0.0284, 95% CI 0.0078-0.0490, p = .0069), day-15 (ß 0.0496, 95% CI 0.0242-0.0750, p = .0001) and day-16 (ß 0.0327, 95% CI 0.0080-0.0574, p = .0093).Similar figures were observed considering the PM10 exposure and limiting the analyses to infants with respiratory syncytial virus. CONCLUSION: This study shows for the first time a direct association between PM2.5 and PM10 levels and the severity of bronchiolitis.

PCSK9 Confers Inflammatory Properties to Extracellular Vesicles Released by Vascular Smooth Muscle Cells.

Vascular smooth muscle cells (VSMCs) are key participants in both early- and late-stage atherosclerosis and influence neighbouring cells possibly by means of bioactive molecules, some of which are packed into extracellular vesicles (EVs). Proprotein convertase subtilisin/kexin type 9 (PCSK9) is expressed and secreted by VSMCs. This study aimed to unravel the role of PCSK9 on VSMCs-derived EVs in terms of content and functionality. EVs were isolated from human VSMCs overexpressing human PCSK9 (VSMCPCSK9-EVs) and tested on endothelial cells, monocytes, macrophages and in a model of zebrafish embryos. Compared to EVs released from wild-type VSMCs, VSMCPCSK9-EVs caused a rise in the expression of adhesion molecules in endothelial cells and of pro-inflammatory cytokines in monocytes. These acquired an increased migratory capacity, a reduced oxidative phosphorylation and secreted proteins involved in immune response and immune effector processes. Concerning macrophages, VSMCPCSK9-EVs enhanced inflammatory milieu and uptake of oxidized low-density lipoproteins, whereas the migratory capacity was reduced. When injected into zebrafish embryos, VSMCPCSK9-EVs favoured the recruitment of macrophages toward the site of injection. The results of the present study provide evidence that PCSK9 plays an inflammatory role by means of EVs, at least by those derived from smooth muscle cells of vascular origin.

Stress Modifies the Expression of Glucocorticoid-Responsive Genes by Acting at Epigenetic Levels in the Rat Prefrontal Cortex: Modulatory Activity of Lurasidone.

Epigenetics is one of the mechanisms by which environmental factors can alter brain function and may contribute to central nervous system disorders. Alterations of DNA methylation and miRNA expression can induce long-lasting changes in neurobiological processes. Hence, we investigated the effect of chronic stress, by employing the chronic mild stress (CMS) and the chronic restraint stress protocol, in adult male rats, on the glucocorticoid receptor (GR) function. We focused on DNA methylation specifically in the proximity of the glucocorticoid responsive element (GRE) of the GR responsive genes Gadd45ß, Sgk1, and Gilz and on selected miRNA targeting these genes. Moreover, we assessed the role of the antipsychotic lurasidone in modulating these alterations. Chronic stress downregulated Gadd45ß and Gilz gene expression and lurasidone normalized the Gadd45ß modification. At the epigenetic level, CMS induced hypermethylation of the GRE of Gadd45ß gene, an effect prevented by lurasidone treatment. These stress-induced alterations were still present even after a period of rest from stress, indicating the enduring nature of such changes. However, the contribution of miRNA to the alterations in gene expression was moderate in our experimental conditions. Our results demonstrated that chronic stress mainly affects Gadd45ß expression and methylation, effects that are prolonged over time, suggesting that stress leads to changes in DNA methylation that last also after the cessation of stress procedure, and that lurasidone is a modifier of such mechanisms.

Human endogenous retroviruses env gene expression and long terminal repeat methylation in colorectal cancer patients.

Human endogenous retroviruses (HERV) are remnants of exogenous retroviral infections, representing 8% of the human genome. Their regulation is based on the DNA methylation of promoters, the long terminal repeats (LTRs). Transcripts from HERV have been associated with cancers, but reports concerning HERV expression in colorectal cancer remain sporadic. Sixty-three patients with advanced stages of colorectal cancer were enrolled in this study. The expressions of HERV env gene, and HERV-H, -K, -R and -P LTRs and Alu, LINE-1 methylation levels, were investigated in the tumor, normal adjacent tissues, and, where possible, blood and plasmatic extracellular vesicles (EVs). Associations among HERV env expression, methylation status and clinical characteristics were evaluated. No differences were observed in HERV env gene expression levels among the clinical specimens, while Alu, LINE-1, HERV-H and -K LTRs were demethylated in the tumor compared to the normal adjacent tissues (p < 0.05).The HERV env gene was expressed in the EVs at of 54% (-H), 38% (-K), 31% (-R) patients. Association was not found between HERV env expression and LTR methylation, but significant higher expression of HERV-P and -R env was found in tumor tissues arising from the right colon. Our findings do not demonstrate significant overexpression of the studied HERV in colorectal cancer, but their association with tumor localization and specificity of the changes in DNA methylation of retroelements are shown. HERV sequences were packaged in the EVs and might be transferred from one cell to another.

Particulate Air Pollution, Clock Gene Methylation, and Stroke: Effects on Stroke Severity and Disability.

Circadian rhythm disturbances have been consistently associated with the development of several diseases, particularly cardiovascular diseases (CVDs). A central clock in the brain maintains the daily rhythm in accordance with the external environment. At the molecular level, the clock is maintained by "clock genes", the regulation of which is mainly due to DNA methylation, a molecular mechanism of gene expression regulation, able to react to and be reprogrammed by environmental exposure such as exposure to particulate matter (PM). In 55 patients with a diagnosis of acute ischemic stroke, we showed that PM2.5 exposure experienced before the event influenced clock genes methylation (i.e., circadian locomotor output cycles protein kaput CLOCK, period 2 PER2, cryprochrome 1 CRY1, Neuronal PAS Domain Protein 2 NPAS2), possibly modulating the patient prognosis after the event, as cryptochrome 1 CRY1 and period 1 PER1 methylation levels were associated with the Rankin score. Moreover, if PM2.5 annual average was low, CRY1/CRY2 methylation levels were positively associated with the National Institutes of Health Stroke Scale (NIHSS) score, whereas they were negatively associated if PM2.5 exposure was high. Whether epigenetic changes in clock genes need to be considered as a prognostic marker of stroke or rather a causal agent in stroke development remains to be determined. Further studies are needed to determine the role of clock gene methylation in regulating the response to and recovery after a stroke event.

Short-term particulate matter exposure influences nasal microbiota in a population of healthy subjects.

BACKGROUND: Exposure to air pollutants, such as particulate matter (PM), represents a growing health problem. The aim of our study was to investigate whether PM could induce a dysbiosis in the nasal microbiota in terms of α-diversity and taxonomic composition. METHODS: We investigated structure and characteristics of the microbiota of 40 healthy subjects through metabarcoding analysis of the V3-V4 regions of the 16s rRNA gene. Exposure to PM10 and PM2.5 was assessed with a personal sampler worn for 24h before sample collection (Day -1) and with measurements from monitoring stations (from Day -2 to Day -7). RESULTS: We found an inverse association between PM10 and PM2.5 levels of the 3rd day preceding sampling (Day -3) and α-diversity indices (Chao1, Shannon and PD_whole_tree). Day -3 PM was inversely associated also with the majority of analyzed taxa, except for Moraxella, which showed a positive association. In addition, subjects showed different structural profiles identifying two groups: one characterized by an even community and another widely dominated by the Moraxella genus. CONCLUSIONS: Our findings support the role of PM exposure in influencing microbiota and altering the normal homeostasis within the bacterial community. Whether these alterations could have a role in disease development and/or exacerbation needs further research.

Acute particulate matter affects cardiovascular autonomic modulation and IFN-γ methylation in healthy volunteers.

AIMS: Air particulate matter (PM) is associated with increased cardiovascular morbidity and mortality. Altered autonomic functions play a key role in PM-induced cardiovascular disease. However, previous studies have not address the impact of PM on sympathetic and parasympathetic control of heart function, independently, and using controlled conditions, i.e., increasing titration of PM of known composition, in absence of other potential confounding factors. To fill this gap, here we used symbolic analysis that is capable of detecting non-mutual changes of the two autonomic branches, thus considering them as independent, and concentrations of PM as they could be measured at peak levels in Milan during a polluted winter day. METHODS AND RESULTS: In this randomized, cross-over study, we enrolled 12 healthy subjects who underwent two random sessions: inhalation of filtered air mixture or inhalation of filtered air containing particulate mixture (PM 10, PM 2.5, PM 1.0 and PM 0.5µm). ECG and respiration for autonomic analysis and blood sample for DNA Methylation were collected at baseline (T1), after air exposure (T2) and after 2h (T3). Spectral and symbolic analysis of heart rate variability (HRV) were performed for autonomic control of cardiac function, while alterations in DNA methylation of candidate genes were used to index pro-inflammatory modifications. In the PM expose group, autonomic analysis revealed a significant decrease of 2UV%, index of parasympathetic modulation (14% vs 9%, p = 0.0309), while DNA analysis showed a significant increase of interferon γ (IFN- γ) methylation, from T1 to T3. In a mixed model using T1, T2 and T3, fine and ultrafine PM fractions showed significant associations with IFN- γ methylation and parasympathetic modulation. CONCLUSIONS: Our study shows, for the first time, that in healthy subjects, acute exposure to PM affects parasympathetic control of heart function and it increases methylation of a pro-inflammatory gene (i.e. methylation of interferon γ). Thus, our study suggests that, even in absence of other co-factors and in otherwise healthy individuals, PM per se is sufficient to trigger parasympathetic dysautonomia, independently from changes in sympathetic control, and inflammation, in a dose-dependent manner.

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.

Short-term particulate matter exposure induces extracellular vesicle release in overweight subjects.

BACKGROUND: Extracellular vesicles (EVs) represent a plausible molecular mechanism linking particulate matter (PM) inhalation to its systemic effects. Microvesicles (MVs) are released from many cell types in response to various stimuli. Increased body mass index (BMI) could modify the response to PM exposure due to enhanced PM uptake and/or an underlying pro-oxidative state. We investigated the relationship between EV release and PM10/PM2.5 exposure in a cohort of 51 volunteers. Subjects were stratified based on their BMI to evaluate whether overweight BMI is a determinant of hypersusceptibility to PM effects. RESULTS: Exposure to PM10/PM2.5 was assessed with a personal sampler worn for 24hours before plasma collection and confirmed with monitoring station data. Size and cellular origin of plasma EVs were characterized by Nanosight analysis and flow cytometry, respectively. Multivariate regression models were run after log-transformation, stratifying subjects based on BMI (≥ or <25kg/m2). PM exposure resulted in increased release of EVs, with the maximum observed effect for endothelial MVs. For PM10 and PM2.5, the adjusted geometric mean ratio and 95% confidence interval were 3.47 (1.30, 9.27) and 3.14 (1.23, 8.02), respectively. Compared to those in normal subjects, PM-induced EV alterations in overweight subjects were more pronounced, with visibly effect in all MV subtypes, particularly endothelial MVs. CONCLUSIONS: Our findings emphasize the role of EV release after PM exposure and the susceptibility of overweight subjects. Larger studies with accurate exposure assessment and complete EVs characterization/content analysis, could further clarify the molecular mechanism responsible for PM effects and of hypersusceptibility of overweight subjects.

Extracellular vesicle-packaged miRNA release after short-term exposure to particulate matter is associated with increased coagulation.

BACKGROUND: Exposure 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. RESULTS: Short-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. CONCLUSIONS: Research 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.