Puerarin suppresses high glucose-induced MCP-1 expression via modulating histone methylation in cultured endothelial cells

AimsHyperglycemia is commonly associated with microcirculation dysfunction. The purpose of the present study was to investigate the epigenetic mechanism involved in the repression of monocyte chemoattractant protein-1 (MCP-1) expression by puerarin under high glucose (25 mM) condition.Main methodsMCP-1 gene expression was measured by Real-Time quantitative Polymerase Chain Reaction (RT-qPCR), the histone 3 lysine 4 methylation (H3K4me) and lysine 9 methylation (H3K9me) were evaluated using chromatin immunoprecipitation assay.Key findingsPuerarin significantly inhibited high glucose-induced upregulation of H3K4 di- and tri-methylation (H3K4me2/3) on the MCP-1 gene promotor. Additionally, the enrichment of H3K4 histone methyltransferases including MLL, menin and SET7 on the MCP-1 promotor was increased, while the demethylase LSD1 was decreased in EA.hy926 cells following exposure to high glucose. The changes of the above enzymes were reversed by puerarin treatment. The mRNA expression of MCP-1 was increased by LSD1 blockage, while was decreased by MLL3 blockage.SignificanceOur findings suggested that puerarin plays a critical role in transcriptional repression of high glucose-induced MCP-1 gene expression, at least in part due to alteration of H3K4me2/3 methylation, thus possesses a therapeutic potential in diabetes-induced vascular injuries.