Abstract
Background: Environmental events and nutritional conditions may induce permanent DNA methylation changes in utero during the sensitive period and these adaptive changes may be ‘memorized’ and have a lasting impact on adult disease later in life. The potential plasticity of DNA methylation also enables reprogramming, depending on exposure to nutritional, chemical, and environmental factors. We determined the effects of exercise training during pregnancy on epigenetic modifications in offspring.Results: Twenty-four subjects were chosen from a previous clinical study. Overweight/obese pregnant women (body mass index <28/≥28kg/m2) who had an uncomplicated pregnancy at <12+6 weeks of gestation were randomly allocated to either an exercise or a control group. Patients allocated to the exercise group performed 3 exercise bouts per week (at least 30 min/session with a rating of perceived exertion between 12-14) via a cycling program that was initiated within 3 days of randomization until 37 weeks of gestation. Patients allocated to the control group continued their usual daily activities. Maternal blood, as well as umbilical cord blood samples, were collected and DNA methylation levels were determined by Illumina MethylationEPIC microarray. Nine CpG sites and corresponding genes UMAD1, RPA3, PLAGL2, POFUT1, SPATA17, GPATCH2, CEP170, MPHOSPH10, MCEE, as well as MRGPRD showed differential trends in control and exercise groups in maternal blood. Furthermore, four specific genes in umbilical cord blood were differentially methylated in the exercise group compared to the sedentary controls (p < 0.01). Conclusions: DNA methylation in maternal blood is dynamically altered during pregnancy and remodeled by exercise training. Thus, intrauterine environmental exposures play an important role in fetal programming. Epigenetic mechanisms involving changes in DNA methylation may provide an explanation for the phenomenon. Our findings shed light on understanding of long-term effects of in utero exposures on the epigenetic landscape of the offspring.
Prenatal Arsenic Exposure and DNA Methylation in Maternal and Umbilical Cord Blood Leukocytes