DNA methylation profiling of nenonatal murine hearts

The neonatal murine heart is able to regenerate after severe injury, however this capacity quickly diminishes within the first week of life. Since DNA methylation is one of epigenetic mechanisms that plays a crucial role in cell development and gene expression regulation, we explored the changes of DNA methylation and gene expression patterns which accompany the loss of the transient regenerative potential in the heart. We used MeDIP-chip approach in order to compare global DNA methylation profiles in the murine hearts at 1 day and 7 days after birth, as well as, in hearts of mice at the age of 2 and 8 weeks. The comparison exposed a number of DNA promoter regions significantly changing their DNA methylation status between these time-points. As the result a number of DMRs have been identified which show an overrepresentation of genes which are critical for proper heart maturation and muscle development. The methylome transition from d1 to d7 is characterized by the excess of gene regulatory regions which gain over those that lose DNA methylation, thus suggesting that a number of genes active at d1 are repressed at d7. genome-wide DNA methylation profiling in the hearts of C57BL/6J mouse