Epigenetic mechanisms underlying variation of IL-6, a well-established inflammation biomarker and risk factor for cardiovascular disease

Jessica I Lundin; Ulrike Peters; Yao Hu; Farah Ammous; Emelia J Benjamin; Joshua C Bis; Jennifer A Brody; Mary Cushman; Harriett Fuller; Chris Gignoux; Xiuqing Guo; Jeff Haessler; Chris Haiman; Roby Joehanes; Silva Kasela; Eimear Kenny; Tuuli Lappalainen; Daniel Levy; Chunyu Liu; Yongmei Liu; Ruth J F Loos; Tara Matise; Kari E North; Sungshim L Park; Scott M Ratliff; Alex Reiner; Stephen S Rich; Jerome I Rotter; Jennifer A Smith; Nona Sotoodehnia; Russell Tracy; David Van den Berg; Ting Ye; Wei Zhao; Laura M Raffield; Charles Kooperberg; PAGE Study

doi:10.1016/j.atherosclerosis.2025.120219

Epigenetic mechanisms underlying variation of IL-6, a well-established inflammation biomarker and risk factor for cardiovascular disease

Atherosclerosis. 2025 May 20:407:120219. doi: 10.1016/j.atherosclerosis.2025.120219. Online ahead of print.

Authors

Jessica I Lundin¹, Ulrike Peters², Yao Hu³, Farah Ammous⁴, Emelia J Benjamin⁵, Joshua C Bis⁶, Jennifer A Brody⁷, Mary Cushman⁸, Harriett Fuller⁹, Chris Gignoux¹⁰, Xiuqing Guo¹¹, Jeff Haessler¹², Chris Haiman¹³, Roby Joehanes¹⁴, Silva Kasela¹⁵, Eimear Kenny¹⁶, Tuuli Lappalainen¹⁷, Daniel Levy¹⁸, Chunyu Liu¹⁹, Yongmei Liu²⁰, Ruth J F Loos²¹, Tara Matise²², Kari E North²³, Sungshim L Park²⁴, Scott M Ratliff²⁵, Alex Reiner²⁶, Stephen S Rich²⁷, Jerome I Rotter²⁸, Jennifer A Smith²⁹, Nona Sotoodehnia³⁰, Russell Tracy³¹, David Van den Berg³², Ting Ye³³, Wei Zhao³⁴, Laura M Raffield³⁵, Charles Kooperberg³⁶; PAGE Study

Affiliations

¹ Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA. Electronic address: Jlundin2@fredhutch.org.
² Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA; Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA. Electronic address: upeters@fredhutch.org.
³ Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA. Electronic address: yhu23@fredhutch.org.
⁴ Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA. Electronic address: fammous@umich.edu.
⁵ Boston Medical Center, Boston University Chobanian and Avedisian School of Medicine, Boston University School of Public Health, Boston, MA, USA. Electronic address: emelia@bu.edu.
⁶ Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA. Electronic address: joshbis@uw.edu.
⁷ Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA. Electronic address: jeco@uw.edu.
⁸ Department of Medicine, Larner College of Medicine at the University of Vermont, Burlington, VT, USA. Electronic address: mary.cushman@uvm.edu.
⁹ Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA. Electronic address: hfuller@fredhutch.org.
¹⁰ Quantitative Biology, University of Colorado, Boulder, CO, USA. Electronic address: chris.gignoux@cuanschutz.edu.
¹¹ The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA. Electronic address: xguo@lundquist.org.
¹² Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA. Electronic address: jhaessle@WHI.org.
¹³ Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. Electronic address: christopher.haiman@med.usc.edu.
¹⁴ Population Sciences Branch, National Heart, Lung, and Blood Institute of the National Institutes of Health, Bethesda, MD, USA; Framingham Heart Study, Framingham, MA, USA. Electronic address: roby.joehanes@nih.gov.
¹⁵ New York Genome Center, New York, NY, USA. Electronic address: silva.kasela@gmail.com.
¹⁶ Icahn School of Medicine at Mount Sinai, New York, NY, USA. Electronic address: eimear.kenny@mssm.edu.
¹⁷ New York Genome Center, New York, NY, USA. Electronic address: tlappalainen@nygenome.org.
¹⁸ Population Sciences Branch, National Heart, Lung, and Blood Institute of the National Institutes of Health, Bethesda, MD, USA. Electronic address: levyd@nhlbi.nih.gov.
¹⁹ Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA. Electronic address: liuc@bu.edu.
²⁰ Duke Molecular Physiology Institute, Duke University, Durham, NC, USA. Electronic address: yongmei.liu@duke.edu.
²¹ Icahn School of Medicine at Mount Sinai, New York, NY, USA. Electronic address: ruth.loos@mssm.edu.
²² Department of Genetics, Rutgers University, New Brunswick, NJ, USA. Electronic address: matise@rutgers.edu.
²³ Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA. Electronic address: kari_north@unc.edu.
²⁴ Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA. Electronic address: lpark@cc.hawaii.edu.
²⁵ Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA. Electronic address: ratliffs@umich.edu.
²⁶ Department of Epidemiology, University of Washington, Seattle, WA, USA. Electronic address: apreiner@uw.edu.
²⁷ Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA. Electronic address: ssr4n@virginia.edu.
²⁸ The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA. Electronic address: jrotter@lundquist.org.
²⁹ Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA; Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA. Electronic address: smjenn@umich.edu.
³⁰ Cardiovascular Health Research Unit, Harborview Medical Center, Seattle, WA, USA. Electronic address: nsotoo@uw.edu.
³¹ Department of Pathology and Laboratory Medicine, Larner College of Medicine at the University of Vermont, Burlington, VT, USA. Electronic address: Russell.Tracy@uvm.edu.
³² Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. Electronic address: dvandenb@usc.edu.
³³ Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA, USA. Electronic address: tingye1@uw.edu.
³⁴ Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA. Electronic address: zhaowei@umich.edu.
³⁵ Department of Genetics, University of North Carolina, Chapel Hill, NC, USA. Electronic address: laura_raffield@unc.edu.
³⁶ Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA. Electronic address: clk@fredhutch.org.

PMID: 40480020
DOI: 10.1016/j.atherosclerosis.2025.120219

Abstract

Background and aims: Cardiovascular disease (CVD) is one of the leading causes of morbidity and mortality worldwide, yet the underlying molecular mechanisms remain less understood. Chronic low-grade inflammation is a complex immune response contributing to the pathophysiology of cardiovascular disease. This response is signaled in part by interleukin-6 (IL-6), a pleiotropic, pro-inflammatory cytokine. Phenotypic variance in circulating IL-6 level may be explained in part by DNA methylation which is increasingly being associated with cardiovascular effects.

Methods: In this study we evaluated methylated DNA (CpG sites) associated with blood IL-6 levels across ∼4,400 ancestrally diverse individuals (81 % self-reported White; 9 % Black or African American, 8 % Hispanic or Latino/a, and 2 % Chinese American).

Results: We identified 178 CpG sites associated with IL-6 (p<0.05/∼395,000). Among the sites, cg04437762 is located within the transcription unit of IL6R, a current therapeutic target for inflammatory disease, and cg26692003 and cg00464927 were significant for IL6 and IL6ST trans-CpG-gene transcripts. Functional gene expression downstream of methylation identified cellular response to IL-6 and B-cell regulation and activation pathways. Four genes were linked with both a genetic component of cardiovascular disease and an IL-6 associated CpG site. Three CpG sites identified through Mendelian randomization analyses supported inference of a causal effect on IL-6 levels, including the LYN gene that regulates immune cell signaling and has been previously associated with atherosclerosis.

Conclusions: Overall, we identified several novel IL-6-CpG sites and downstream pathways affected by methylation. Follow-up functional studies including the regulation of IL-6 would complement current knowledge of CVD pathophysiology and potential therapeutic targets.