Epigenome-Scale Comparison of DNA Methylation Between Blood Leukocytes and Bronchial Epithelial Cells

Abstract

Aim: Agreement in DNA methylation (DNAm) at the genome scale between blood leukocytes (BL) and bronchial epithelial cells (BEC) is unknown. We examine as to what extent DNAm in BL is comparable with that in BEC and serves as a surrogate for BEC. Materials & methods: Overall agreement (paired t-tests with false discovery rate adjusted p > 0.05) and consistency (Pearson’s correlation coefficients >0.5) between two tissues, at each of the 767,412 CpGs, were evaluated. Results: We identified 247,721 CpGs showing overall agreement and 47,371 CpGs showing consistency in DNAm. Identified CpGs are involved in certain immune pathways, indicating the potential of using blood as a biomarker for BEC at those CpGs in lower airway-related diseases. Conclusion: CpGs showing overall agreement and those without overall agreement are distributed differently on the genome.

Keywords::

• blood leukocytes
• bronchial epithelial cells
• DNA methylation
• Isle of Wight

Supplementary data

To view the supplementary data that accompany this paper please visit the journal website at: www.tandfonline.com/doi/suppl/10.2217/epi-2020-0384

Author contributions

Y-S Lee and H Zhang carried out the project and drafted the manuscript. H Zhang conceived the study and provided guidance on the analytical and statistical aspects. Y Jiang provided guidance on analytical and statistical aspects. Y-S Lee did data management and performed all the statistical analyses. L Kadalayil was involved in the Isle of Wight Birth cohort data management and preprocessing and revised the manuscript. JW Holloway and SL Ewart supervised the DNA methylation measurement and revised the manuscript. JW Holloway and W Karmaus provided guidance on data analyses. SH Arshad was involved sample collection, data acquisition, DNA-M arraying, study design and critical revision. All authors read and approved the final manuscript.

Acknowledgments

The authors thanked A Alhendi for his invaluable help in data analyses, and the nurses and staff at the David Hide Asthma & Allergy Research Centre, Isle of Wight, UK, for their help in recruitment and sample collection.

Financial & competing interests disclosure

This work was supported by National Institutes of Health (NIH) under grant [R01AI121226] (PIs: Zhang and Holloway); (R01HL132321); and (R03HD092776) (PI: Karmaus). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This work was supported by National Institutes of Health (NIH) under grant [R01AI121226] (PIs: Zhang and Holloway); (R01HL132321); and (R03HD092776) (PI: Karmaus). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.