Association of CYP26C1 Promoter Hypomethylation with Small Vessel Occlusion in Korean Subjects

The risk factors for stroke, a fatal disease, include type two diabetes, hypertension, and genetic influences. Small vessel occlusion (SVO) can be affected by epigenetic alterations, but an association between SVO and the methylation of cytochrome P450 family 26 subfamily C member 1 (CYP26C1) has not been identified. In this study, we measured the level of DNA methylation in the CYP26C1 promoter and the 5 & PRIME; untranslated region of 115 normal subjects and 56 patients with SVO in Korea. The DNA methylation level of each subject was measured by bisulfite amplicon sequencing, and statistical analysis was performed using the general linear model or Pearson's correlation. The average level of DNA methylation was markedly lower in patients with SVO than in normal subjects (20.4% vs. 17.5%). We found that the methylation of CYP26C1 has a significant positive correlation with blood parameters including white blood cells, hematocrit, lactate dehydrogenase, and Na+ in subjects with SVO. We predicted that binding of RXR-alpha and RAR-beta might be affected by CYP26C1 methylation at CpG sites -246-237 and -294-285. These findings suggest that CYP26C1 methylation in the promoter region may be a predictor of SVO.