Barcelona de Mendoza Veronica, Huang Yunfeng, Crusto Cindy A, Sun Yan V, Taylor Jacquelyn Y
1 Yale School of Nursing, Orange, CT, USA.
2 Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA.
Biol Res Nurs. 2018 Mar;20(2):145-152. doi: 10.1177/1099800417748759. Epub 2017 Dec 19.
Experiences of racial discrimination have been associated with poor health outcomes. Little is known, however, about how perceived racial discrimination influences DNA methylation (DNAm) among African Americans (AAs). We examined the association of experiences of discrimination with DNAm among AA women in the Intergenerational Impact of Genetic and Psychological Factors on Blood Pressure (InterGEN) study.
The InterGEN study examines the effects of genetic and psychological factors on blood pressure among AA women and their children. Measures include the Major Life Discrimination (MLD) and the Race-Related Events (RES) scales. In the present analysis, we examined discrimination and DNAm at baseline in the InterGEN study. The 850K EPIC Illumina BeadChip was used for evaluating DNAm in this epigenome-wide association study (EWAS).
One hundred and fifty-two women contributed data for the RES-EWAS analysis and 147 for the MLD-EWAS analysis. Most were 30-39 years old, nonsmokers, had some college education, and had incomes <US$15,000/year. After controlling for age, smoking, and cell composition, MLD was significantly associated with DNAm at nine CpG (regions of DNA where a cytosine nucleotide is followed by a guanine nucleotide) sites (false discovery rate [FDR]-corrected p < .05). For the RES-EWAS analysis, no DNAm sites passed the epigenome-wide significance level after genomic control, though suggestive associations were observed at CpG sites after genomic control (raw p < 10).
We observed significant epigenetic associations between disease-associated genes (e.g., schizophrenia, bipolar disorder, and asthma) and perceived discrimination as measured by the MLD Scale. Future health disparities research should include epigenetics in high-risk populations to elucidate functional consequences induced by the psychosocial environment.
种族歧视经历与不良健康结果相关。然而，关于感知到的种族歧视如何影响非裔美国人（AA）的DNA甲基化（DNAm），人们知之甚少。在“遗传和心理因素对血压的代际影响”（InterGEN）研究中，我们考察了AA女性中歧视经历与DNAm之间的关联。
InterGEN研究考察了遗传和心理因素对AA女性及其子女血压的影响。测量指标包括重大生活歧视（MLD）量表和种族相关事件（RES）量表。在本分析中，我们在InterGEN研究的基线阶段考察了歧视与DNAm。在这项全表观基因组关联研究（EWAS）中，使用85万位点的Illumina EPIC芯片评估DNAm。
152名女性为RES-EWAS分析提供了数据，147名女性为MLD-EWAS分析提供了数据。大多数女性年龄在30 - 39岁之间，不吸烟，接受过一些大学教育，年收入<15,000美元。在控制了年龄、吸烟和细胞组成后，MLD与9个CpG（胞嘧啶核苷酸后接鸟嘌呤核苷酸的DNA区域）位点的DNAm显著相关（错误发现率[FDR]校正p < 0.05）。对于RES-EWAS分析，基因组控制后没有DNAm位点达到全表观基因组显著性水平，不过在基因组控制后，在CpG位点观察到了提示性关联（原始p < 10）。
我们观察到疾病相关基因（如精神分裂症、双相情感障碍和哮喘）与通过MLD量表测量的感知歧视之间存在显著的表观遗传关联。未来的健康差异研究应将表观遗传学纳入高危人群，以阐明社会心理环境引起的功能后果。
