the trail of an early epigenetic mechanism ⋅ Inserm, From science to health

A study of 668 mother-child pairs shows that maternal blood pressure during pregnancy is associated with the level of expression of placental genes involved in the development of the respiratory system of the unborn child. These results reinforce knowledge on the role of epigenetic mechanisms in the developmental origin of diseases.

Data on the influence of environmental factors on the early development of children are accumulating. Population studies suggest, for example, that the air pollution to which pregnant women may be exposed is associated with poorer respiratory health in their child after birth. These anomalies could be mediated in particular by an increase in maternal blood pressure and by dysfunctions of the placenta, a crucial organ in charge of nutritive, gaseous and hormonal exchanges between the mother and the child. The underlying mechanisms remain to be described more precisely in order to prevent the consequences.

At the Institute for the Advancement of Biosciences in Grenoble, the Environmental Epidemiology Applied to Development and Respiratory Health (EDES) team works precisely to identify avoidable environmental risk factors associated with impaired growth. , neurological development and respiratory health of children. Researchers Lucile Broséus and Johanna Lepeule have studied epigenetics, that is to say the chemical modifications of DNA that modulate gene expression. ” A growing body of work suggests that the epigenetic changes that occur in placental cells are a reflection of environmental exposures during pregnancy, the functioning of the placenta, and the course of pregnancy.explains Johanna Lepeule. To study these changes, we most often measure the level of methylation DNA, one of the best known epigenetic mechanisms. »

Maternal blood pressure and placental DNA methylation

After showing that the exposure of pregnant women to air pollution is associated with changes in the methylation of genes in the cells of the placenta – in particular at the level of genes known to promote hypoxia (lack of oxygen) or pre-eclampsia (hypertensive disease linked to placental dysfunction) – the researchers wanted to assess the placental epigenetic changes associated with the mother’s blood pressure.

This work was conducted with 668 mother-child couples included in the French EDEN cohort