Genome-wide analysis of histone trimethylation in INMA cohort exposed to BPA revealed a global impact on telomeric binding proteins and histone acetyltransferase factors

This study was developed under the framework of the Human Biomonitoring for Europe Initiative (HBM4EU). We evaluated the possible impacts of BPA exposure in adolescent males from the INMA-Granada cohort (Spain) with the goal of identifying new biomarkers that could be useful in biomonitoring and epidemiological studies. Our hypothesis is that alterations in epigenetic regulation could lead to genetic instability in human subjects exposed to environmentally relevant doses of BPA. Overall design: Methods: We used chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq) technique and H3K4me3 antibody (Milipore, 07-4730). The experiments were done with material extracted from whole human blood with low (0.66-2.55) or high (10.07-42.64 microg/gram/creatinine) levels of BPA. The chromatin was fixed, shared and incubated with H3K4me3 antibody. The immunoprecipitated DNA was purified with MiniElute Reaction Clean-Up kit (Qiagen) and the DNA concentration was measured using QuantiFluor dsDNA system (Promega). A minimum of ~3 ng of DNA was recovered. Sequencing libraries were prepared using NEBNext Ultra DNA Library Prep Kit for Illumina (E7645S; NEB). Sequencing was performed on an Illumina HiSeq4000 sequencer using a single-end 50-base read in multiplexed mode. Reads were aligned to the human GRCh38 reference genome. Wig files were generated using with an in-house script (Variable step, span=25, reads were elongated to 200b).