Environmental Exposure study with RNA-Seq data on dbGaP (65 participants)

phs003657 — The Effects of Long-Term Heavy Metal Exposure on Transcriptome Landscape    in Human Peripheral Blood Cells

The present study investigates the impact of long-term residence in a mining area on transcriptome changes induced by heavy metal exposure in human peripheral blood mononuclear cells (PBMCs) from 65 healthy subjects selected from the general population. This study includes the same participants which were recruited in our previous investigation on heavy metal long-term environmental exposure-related gene-specific methylation changes (<a href="https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bihttps://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs003392.v1.p1">phs003392.v1.p1</a>). We performed a differential expression analysis to compare the mRNA transcriptome of 31 residents from the mining region (MRR) - individuals living in the Kapan mining area with reported environmental exposures to heavy metals - with that of 34 residents from non-mining regions (NMR) - individuals residing at a considerable distance from mining locations. We also evaluated the potential association of gene expression profiles with the blood metallome, including levels of Ca, Mg, Co, Fe, Mn, Cu, Mo, Se, Zn, As, Sb, Tl, Be, V, Ni. Poly-A selected strand-specific mRNA library was prepared with Illumina Stranded mRNA Prep kit. The sequencing was performed on the Illumina NovaSeq-6000 platform with 38.5 million single-end 100 bp reads on average generated per sample. Quality checking of the sequencing data was performed using Illumina Basespace reports and the program FastQC (V0.10.1). Reads were aligned against the Human Genome Hg38 using STAR (version 2.7.1a). According to our findings, long-term residence in a mining area is correlated with alterations in the blood transcriptome, with responses varying by sex. Pathway analysis revealed upregulation of immune response related pathways, and downregulation of translation and ribosome biogenesis in the PBMCs of the MRR. Pathways related to metal ion transmembrane transport, epigenetic modifications (histone deacetylases (HDACs) and DNA methylation) were upregulated in males, while in females mostly transcripts involved in inflammation and cytokine mediated signaling were upregulated. Additionally, among the dysregulated pathways, the TNF-α signaling via NF-κB showed opposite changes in females and males.