DJ-1 is involved in epigenetic control of sphingosine-1-phosphate receptor expression in vascular neointima formation

DJ-1 and sphingosine-1-phosphate (S1P) receptors (S1PRs) are implicated in the control of physiology and pathophysiology of cardiovascular systems such as blood pressure, atherosclerosis, and restenosis. Here, we investigated whether DJ-1 with antioxidant function participates in the regulation of S1PR1 and S1PR2 expression in vascular smooth muscle cells (VSMCs) and whether this response is related to vascular neointima formation. In vitro studies used cellular migration assay, western blot, reverse transcriptase and real-time PCR analysis, and immunocytochemistry. In vivo studies were performed using the carotid artery ligation model together with immunohistochemistry in DJ-1 knockout (DJKO) and corresponding wild-type (DJWT) mice. S1P stimulated migration of VSMCs from DJKO and DJWT mice. VSMC migration was suppressed by S1PR1 inhibitor but was elevated by S1PR2 inhibitor. Compared with DJWT mice, S1PR1 expression was higher in VSMCs and neointimal plaque from DJKO mice, but S1PR2 expression was lower. Overexpression of DJ-1 in DJKO VSMCs reduced S1PR1 expression and elevated S1PR2 expression. Compared with DJWT mice, histone deacetylase-1 recruitment and histone H3 acetylation at the S1PR1 promoter region were lower and higher, respectively, but this pattern was reversed at the S1PR2 promoter region in DJKO VSMCs. S1PR expressions and epigenetic changes at S1PR promoter regions in DJWT VSMCs treated with H₂O₂ showed similar patterns to those in DJKO VSMCs. Our findings suggest that DJ-1 may be involved in the regulation of S1PR1 and S1PR2 expression via H₂O₂-mediated histone modification in VSMCs. Consequently, this modification may affect S1P-induced VSMC migration and be related to vascular neointima formation.