Smoking-associated AHRR hypomethylation enables monocyte-specific enhancer activation, and upregulation of noncoding and coding RNA
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ABSTRACT: While tobacco smoke exposure strongly influences DNA methylation and is causative in numerous human diseases, the underlying mechanistic links are obscure. Here we investigated genome-wide smoking-associated differentially methylated regions (SM-DMRs) using CD14 monocytes of smokers (n=47) and nonsmokers (n=46) from two independently recruited populations, the Multi-Ethnic Study of Atherosclerosis (MESA) and Clinical Research Unit (CRU) at NIEHS. We found that SM-DMRs preferentially occur at genomic regions with the characteristics of putative enhancer, open chromatin, and the enrichment of TF binding indicated by ENCODE/Roadmap Epigenome/BLUEPRINT datasets. Most of our selected candidate SM-DMRs identified in the two populations were also observed in other hematopoietic cell types (CD15 granulocytes, CD19 B cells, CD4 T cells, CD8 T cells, CD56 NK cells) and were successfully validated using a second method in an independently recruited group of subjects. Aryl-Hydrocarbon Receptor Repressor (AHRR) SM-DMR, located at an intragenic enhancer, was the most significantly affected DMR and we have previously reported that a methylation level of a CpG in this gene was associated with subclinical atherosclerosis. The AHRR DMR was also detected in saliva DNA and these results were highly correlated with effects in monocytes (r2 = 0.90), suggesting that saliva may provide a potential alternative, noninvasive source for biomarkers that use DNA. Mechanistically, our results suggested that AHRR SM-DMR upregulated AHRR mRNA through activating AHRR enhancer in monocytes of smokers but not in granulocytes, indicated by increased noncoding RNA. Taken together, our study suggests that cell type-specific activation of enhancers at SM-DMRs may represent a mechanism driving smoking-related disease.
ORGANISM(S): Homo sapiens
PROVIDER: GSE104700 | GEO | 2017/12/19
SECONDARY ACCESSION(S): PRJNA413538
REPOSITORIES: GEO
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