Establishment of DNA Methylation Profile Associated with TCM Syndrome in Endometriosis

OBJECTIVES: To screen the potential epigenetic biomarkers associated with endometriosis (EMS) and traditional Chinese medicine (TCM) syndrome EMS types. METHODS: A cohort of 99 participants comprising 42 EMS patients with cold coagulation blood stasis (CCBS) syndrome, 35 EMS patients with Qi stagnation blood stasis (QSBS) syndrome, and 22 women of childbearing age without EMS were recruited. Reduced representation bisulfite sequencing (RRBS) was used to establish the differential DNA methylation profiles in human peripheral blood samples obtained from four non-EMS and four EMS patients with CCBS or QSBS syndrome, respectively. Differentially expressed genes (DEGs) were verified in 18 non-EMS, 38 CCBS-EMS, and 31 QSBS-EMS using pyrosequencing. RESULTS: Methylation sites of 123942, 127229, and 115961 were found in peripheral blood DNA of non-EMS, CCBS-EMS, and QSBS-EMS patients, respectively. GO and KEGG analyses showed that the pathological process of EMS may be closely related to the nervous system development, cell junctions, GABA-gated chloride ion channel activity, nicotine addiction, Hippo signaling pathway, mRNA surveillance pathway, and Wnt signaling pathway. The methylation level at CpG site within HDAC6 gene in QSBS-EMS patients was significantly different from that in control women. CONCLUSIONS: The changes in DNA methylation in peripheral blood samples may be associated with EMS and TCM syndrome EMS types. The methylation level of HDAC6 gene may be used to distinguish QSBS-EMS patients from women without EMS.