miRNA-based TAPAS II experimental study: respiratory and inflammatory health effects of air pollution and physical activity

The study comprises of 24 subjects that have been exposed to high and low Traffic-related air pollution. Serum samples from 24 subjects have been obtained from the TAPAS II cohort (TAPAS II experimental study: respiratory and inflammatory health effects of air pollution and physical activity). The cohort is a controlled crossover study where each participant executed four different scenarios. Each participant was either resting (rest) or cycling (pa) at low (1) and high (4) traffic-related air pollution sites (in a pedestrian square in la Barceloneta neighborhood and on a bridge 5m above Ronda Litoral, the city’s ring road, respectively) in the city of Barcelona. Plasma samples were recovered from plasma separator tubes following centrifugation of whole blood at 1,600g for 10 min at 4°C. To avoid contamination of the plasma cmiRNAs with blood cell-derived miRNAs, the plasma was subjected to a second centrifugation step at 16,000g before being stored at -80°C (Kroh et al., 2010). Plasma miRNAs were isolated using the miRNeasy Serum/Plasma kit (Qiagen) and the quality was evaluated on a Bioanalyzer using the small RNA Kit (Agilent). Samples were included in the analysis when showing a minimum of 1 ng RNA yield and a peak around 21 nucleotides. The sequencing libraries were prepared using the TruSeq Small RNA-Seq Preparation Kit (Illumina), and sequenced by a HiSeq 2500 (Illumina) according to the manufacture’s protocol