Exposure to Polycyclic Aromatic Hydrocarbons and Accelerated DNA Methylation Aging

Area of Science:

• Environmental Health Sciences
• Epigenetics
• Gerontology

Background:

• Aging increases morbidity and mortality risks, influenced by environmental factors.
• Polycyclic aromatic hydrocarbon (PAH) exposure is linked to adverse health outcomes.
• The connection between PAH exposure and DNA methylation aging, a novel aging biomarker, remains unclear.

Purpose of the Study:

• To investigate the association between PAH exposure and methylation aging.
• To develop and validate a methylation age predictor for Chinese populations.
• To identify specific PAH metabolites associated with accelerated aging.

Main Methods:

• Trained and validated a methylation age predictor using whole blood methylation data from Chinese and Caucasian individuals.
• Defined aging indicators: delta-age (methylation age minus chronological age) and aging rate.
• Evaluated PAH exposure association with aging indicators using linear regressions in Chinese participants, with exposure assessed via urinary monohydroxy-PAH metabolites.

Main Results:

• Developed a robust methylation age predictor accurate for both Chinese and Caucasian populations (R=0.94-0.96).
• 1-hydroxypyrene and 9-hydroxyphenanthrene exposure significantly associated with increased delta-age and aging rate.
• Identified specific CpG sites (e.g., on FHL2, ELOVL2) linked to both aging indicators and PAH exposure.

Conclusions:

• A validated methylation age predictor specific to Chinese populations, also applicable to Caucasians, was developed.
• PAH exposure is suggested to adversely impact human aging and epigenetic alterations in Chinese populations.
• Findings highlight the role of environmental exposures in modulating biological aging processes.