SU54 - A PILOT METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING: HYPERMETHYLATION OF THE DEATH-ASSOCIATED PROTEIN 3 (DAP3) AND MIR2110 IN FIBROMYALGIA ASSOCIATED WITH CHILD ABUSE HISTORY AMONG AFRICAN AMERICAN FEMALES

Abstract

Background Epigenetics, such as DNA methylation, has been hypothesized as one possible mechanism to explain the association between adverse childhood experiences and later health problems. The goal of this study was to identify genome-wide DNA methylation markers from peripheral blood associated with child abuse history among 6 African American adult females with Fibromyalgia Syndrome (FMS) using Methylated DNA Immuno-Precipitation sequencing (MeDIP-Seq). Methods Data were from a fibromyalgia, natural history study approved by the MedStar Health IRB. FMS was diagnosed using the 1990 or the 2010 American College of Rheumatology criteria and the Widespread Pain Index. Pain, fatigue, anxiety, depression, and cognitive function were assessed. A detailed abuse history was obtained, including age at the time and type of abuse (i.e., emotional, physical, or rape). A total of 6 FMS African American females, including 4 with any abuse before age 18 (Abused FMS female; AbFF) and 2 without (Non-abused FMS female; NFF), were selected in this study. Using peripheral blood collected from the subjects’ genomic DNA was extracted. DNA fragments containing methylated CpG were enriched and sequenced in the HiSeq-2500 system using MeDIP-Seq. Reads were aligned to the reference human genome of hg38. Generated sam files were sorted according to chromosomal position. Peaks were called using MACS version 2.1.1.20160309, to identify methylated DNA regions. DiffBind software package was used to perform clustering, Principal Component Analysis (PCA), and differential peak interval analysis with False Discovery Rate (FDR) of 0.05 cutoff. Results All of the 6 subjects with FMS met both the 1990 and 2010 criteria, except 1 NFF who only met the 1990 criteria. Age ranged from 45 to 56 years (mean=53.5, SD=4.23). The majority (66.7%) did not have a college education, unemployed, or divorced or widowed. Among the 4 AFFs, 1 reported rape + physical abuse, 2 reported rape only, and 1 reported emotional abuse. No significant differences were found in clinical symptoms or characteristics between AbFFs and NFFs. The number of methylated intervals per each subject ranged from 234,842 to 454,508. With the union of all these intervals, we obtained 412,226 methylated intervals, overall. Both of clustering analysis and PCA clearly separated AbFFs and NFFs. The differential analysis with FDR of 0.05 identified 15 intervals hypermethylated for AFPs and another 15 intervals hypermethylated for NFPs. After excluding ambiguous regions to interpret (e.g., repetitive DNA regions such as ribosomal repeating regions, the human alpha satellite repeat region) we identified DAP3 and mir2110 hypermethylated for AbFFs compared to NFFs. Discussion This study suggests hypermethylation in DAP3 and mir2110 could be used as candidates for novel biomarkers associated with child abuse history in African American females with fibromyalgia. Epigenetic inactivation patterns, especially one in DAP3, are found in numerous tumor cells and negatively affect cancer prognosis. Reduced DAP3 expression affects its normal regulation of cell respiration and apoptosis induced by oxidative stress, which is important of cell death pathways related to the ischemia-reperfusion injury. Further study is required to confirm this finding with more clinical samples.