The complex transcriptomics of RNA classes for biomonitoring and mechanistic studies
The effects of exposure to chemical compounds and/or particulate matter on genetic material, including the risks of disease, are frequently evaluated by analyses of biomarkers. Among them, RNA markers play an important role in understanding the changes in the dynamics of transcriptomic processes. Currently, most transcriptome analyses are based on an assessment of individual RNA molecules using qPCR techniques, the application of array approaches, or RNA sequencing techniques with the potential to detect novel transcripts. Despite methodological progress, limitations linked with RNA fragmentation remain and thus many important results can be lost. In this pilot study we tested a new methodological approach of RNA libraries preparation using the RiboMarker® platform in combination with Illumina sequencing to analyze the complex transcriptome, including fragmented RNAs. Four sets of samples collected from firefighters at three time points according to their exposure (before, after – immediately, after – a day later) were analyzed. A wide range of RNA types [non-coding RNAs (rRNA, tRNA, miRNA, snRNA, snoRNA, lncRNA, piRNA) and protein coding mRNAs] were detected which allowed us to track the dynamics of their expression in different time periods. The application of this comprehensive RNA profiling in a large future biomonitoring study is promising: (i) for identification of the novel biomarkers of specific exposures; and (ii) to study the complex mechanisms of transcription including protective adaptation changes, as well as potentially harmful deregulations increasing the risk of diseases, including cancer. Overall design: Small RNA sequencing of cell-free RNA in circulating blood from a time series of four firefighters after fire intervention.