Introduction
Preeclampsia is a hypertensive disorder of pregnancy known to increase the risk of developing cardiovascular disease in the newborn later in life. Exposure to the suboptimal intrauterine environment experienced during preeclampsia may alter the DNA methylation profile of the newborn. The aim of this study was to investigate whether global DNA methylation levels are altered in baboon (Papio hamadryas) offspring of experimental preeclamptic versus normotensive pregnancies.
Methods
Genomic DNA was extracted from whole blood of baboon offspring from experimental preeclamptic (EPE, n=8), and normotensive pregnancies (n=16) (1 EPE: 2 normotensives, matched for age and sex). Global DNA methylation was determined using a colorimetric DNA methylation quantification kit. The amount of methylated DNA was expressed as a percentage of the total DNA. A paired sample t-test was performed to determine whether there were any statistical differences between the two groups. Data are expressed at the mean ± SD.
Results
A total of 8 EPE offspring and 16 normotensive offspring aged between 0.5 and 8 years of age were included in this study. One normotensive individual was excluded due to inadequate DNA quality. The average percent of global DNA methylation was 2.52 ± 0.66% for EPE offspring and 2.35 ± 0.51% for normotensive offspring. There was no significant difference in DNA methlyation between the two groups (t7 = 0.48, P = 0.65).
Conclusion
There were no significant differences in global DNA methylation between offspring of preeclamptic pregnancies compared with their controls. This assay only tests global methylation and does not rule out the possibility of different patterns of DNA methylation between the genomes of the offspring born to EPE and normotensive mothers. Future research could investigate methylation at more specific sites across the genome.