The effect of low and high-intensity cycling in diesel exhaust on flow-mediated dilation, circulating NO_x, endothelin-1 and blood pressure - Fig 2

<p>Mean plasma NO_x in 18 recreationally active males prior to and following 30-min of (a) rest, (b) low-intensity cycling, or (c) high-intensity cycling in filtered air or diesel exhaust. Error bars represent SD. β = significantly different from pre-exercise in the corresponding exposure, in (a) FA is only significant, in (b) and (c) DE is only significant; ϕ = significantly different from 2h occurs in DE only; * = significantly greater than FA at the corresponding time point; ** = significantly greater than rest at the corresponding time point (comparing DE only); λ = significantly different from 1 h occurs in DE only.</p

The effect of low and high-intensity cycling in diesel exhaust on flow-mediated dilation, circulating NO_x, endothelin-1 and blood pressure - Fig 1

<p>Mean (a) pre-occlusion artery diameter, (b) peak artery diameter, (c) time to peak dilation in 17 recreationally active males prior to and following rest, low-intensity, or high-intensity cycling. Error bars represent SD. * = significantly less than post for high-intensity only. ** = significant difference between high-intensity compared to low-intensity and rest at the same time point. β = significant difference between high-intensity compared rest at the same time point.</p

The effect of low and high-intensity cycling in diesel exhaust on flow-mediated dilation, circulating NO_x, endothelin-1 and blood pressure

<div><p>Introduction</p><p>Exposure to air pollution impairs aspects of endothelial function such as flow-mediated dilation (FMD). Outdoor exercisers are frequently exposed to air pollution, but how exercising in air pollution affects endothelial function and how these effects are modified by exercise intensity are poorly understood.</p><p>Objectives</p><p>Therefore, the purpose of this study was to determine the effects of low-intensity and high-intensity cycling with diesel exhaust (DE) exposure on FMD, blood pressure, plasma nitrite and nitrate (NOx) and endothelin-1.</p><p>Methods</p><p>Eighteen males performed 30-minute trials of low or high-intensity cycling (30% and 60% of power at VO_2peak) or a resting control condition. For each subject, each trial was performed once while breathing filtered air (FA) and once while breathing DE (300ug/m³ of PM_2.5, six trials in total). Preceding exposure, immediately post-exposure, 1 hour and 2 hours post-exposure, FMD, blood pressure and plasma endothelin-1 and NOx concentrations were measured. Data were analyzed using repeated-measures ANOVA and linear mixed model.</p><p>Results</p><p>Following exercise in DE, plasma NOx significantly increased and was significantly greater than FA (p<0.05). Two hours following DE exposure, endothelin-1 was significantly less than FA (p = 0.037) but exercise intensity did not modify this response. DE exposure did not affect FMD or blood pressure.</p><p>Conclusion</p><p>Our results suggest that exercising in DE did not adversely affect plasma NO_X, endothelin-1, FMD and blood pressure. Therefore, recommendations for healthy individuals to moderate or avoid exercise during bouts of high pollution appear to have no acute protective effect.</p></div

The main effects of time, exposure condition and intensity on FMD (Mean (SD)) in 17 recreationally active males.

<p>The main effects of time, exposure condition and intensity on FMD (Mean (SD)) in 17 recreationally active males.</p

The effect of low and high-intensity cycling in diesel exhaust on flow-mediated dilation, circulating NO_x, endothelin-1 and blood pressure - Fig 3

<p>Mean plasma endothelin-1 in 18 recreationally active males pre, post, 1 h- and 2 h- post (a) 30-min of exposure to filtered air or diesel exhaust (exposure-by-time interaction), or (b) 30-min of rest, low-intensity cycling, or high-intensity cycling (intensity-by-time interaction). Error bars represent SD. β = significantly greater than pre-exercise (DE only); * = (a) DE significantly less than FA, (b) Rest and low-intensity significantly less than high-intensity at the corresponding time point; ϕ = (a) significantly less than 2 h post occurs in FA only, (b) significantly less than 2 h post occurs in high-intensity only.</p

Variation in RNA-Seq Transcriptome Profiles of Peripheral Whole Blood from Healthy Individuals with and without Globin Depletion

<div><p>Background</p><p>The molecular profile of circulating blood can reflect physiological and pathological events occurring in other tissues and organs of the body and delivers a comprehensive view of the status of the immune system. Blood has been useful in studying the pathobiology of many diseases. It is accessible and easily collected making it ideally suited to the development of diagnostic biomarker tests. The blood transcriptome has a high complement of globin RNA that could potentially saturate next-generation sequencing platforms, masking lower abundance transcripts. Methods to deplete globin mRNA are available, but their effect has not been comprehensively studied in peripheral whole blood RNA-Seq data. In this study we aimed to assess technical variability associated with globin depletion in addition to assessing general technical variability in RNA-Seq from whole blood derived samples.</p><p>Results</p><p>We compared technical and biological replicates having undergone globin depletion or not and found that the experimental globin depletion protocol employed removed approximately 80% of globin transcripts, improved the correlation of technical replicates, allowed for reliable detection of thousands of additional transcripts and generally increased transcript abundance measures. Differential expression analysis revealed thousands of genes significantly up-regulated as a result of globin depletion. In addition, globin depletion resulted in the down-regulation of genes involved in both iron and zinc metal ion bonding.</p><p>Conclusions</p><p>Globin depletion appears to meaningfully improve the quality of peripheral whole blood RNA-Seq data, and may improve our ability to detect true biological variation. Some concerns remain, however. Key amongst them the significant reduction in RNA yields following globin depletion. More generally, our investigation of technical and biological variation with and without globin depletion finds that high-throughput sequencing by RNA-Seq is highly reproducible within a large dynamic range of detection and provides an accurate estimation of RNA concentration in peripheral whole blood. High-throughput sequencing is thus a promising technology for whole blood transcriptomics and biomarker discovery.</p></div

Globin depletion yields 3500 additional robustly detectable transcripts from a single representative peripheral whole blood RNA-Seq experiment.

<p>(A) Correlation plot of the transcript FPKMs of an exemplar biological sample, either globin depleted (y-axis) or not (x-axis). (B) Distribution of transcript FPKMs in the same exemplar biological sample, either globin depleted (blue) or not (red). Data is shown on a log scale. Significant FPKM cutoffs of 1, 2.5 and 1000 are marked by dashed line.</p

Clinical characteristics of the discovery cohort according to statin treatment.

<p>⁽¹⁾The type of statin was not available for one patient.</p><p>⁽²⁾Chi square test.</p><p>⁽³⁾T test.</p><p>NA: Not Available. NS: Not Significant. FEV₁: forced expiratory volume in 1 second; FVC: forced vital capacity; post-BD: post-bronchodilator. Square brackets indicate the number of missing values.</p><p>Clinical characteristics of the discovery cohort according to statin treatment.</p

Globin depletion has no impact on the correlation of technical replicates.

<p>Correlation plot of the transcript FPKMs of lane technical replicate (top) or pooled technical replicate (bottom) exemplar pairs. Data is shown on a log scale. Spearman's <i>rho</i> is reported for all (<i>r</i>_all) or reliably detectable transcripts (<i>r</i>_FPKM≥1) only.</p

Genes (probe sets) differentially expressed between statin groups in the discovery and replication cohorts.

<p>CI is the confidence interval: the value to add and subtract to the log 2 fold change (Log2FC). BH is the Benjamini-Hochberg adjusted p-values. Genes in bold are replicated in at least one cohort (Groningen). Some genes are represented by more than one transcript.</p><p>Genes (probe sets) differentially expressed between statin groups in the discovery and replication cohorts.</p