As part of the BiSC project, placenta samples have been collected on the day of birth. So far, placenta samples from more than 400 mothers have been saved, and 700 are expected to arrive!
The placenta is the organ that is responsible for transferring oxygen and nutrients from the mother’s circulation to the fetus, and also plays a regulatory role in the immune and endocrine levels. In addition, the placenta is able to ensure the proper development of the fetus by protecting it from environmental changes or aggressions through an adaptive response (for example, when there is a decrease in oxygen in the maternal circulation, the number of capillaries In the placenta increases to ensure the supply of oxygen to the fetus). Thus, defects in the placenta can compromise the development of the fetus and predispose the baby to suffer from certain diseases or health complications during his life.
One of the purposes of collecting this type of sample is to be able to measure and study the molecular profiles of this tissue, such as the placental epigenome. The epigenome is the set of mechanisms that regulate gene expression without altering the DNA sequence. These mechanisms are called “epigenetics” and can be modified by environmental factors (age, diet, stress, exercise, etc.), allowing the functional plasticity of cells and adaptation to different environments. Likewise, its alteration can also affect the health and the risk of suffering from diseases; for example, it has been shown that alterations in the placental epigenome that alter the expression of genes on the hypothalamic-pituitary-adrenal axis could compromise the proper development of the brain.
The most studied epigenetic mechanism is DNA methylation, which involves the addition or removal of chemical groups (methyl groups) on the DNA sequence. According to previous studies (conducted by our group and others), environmental factors such as tobacco, air pollution, diet during pregnancy, among others, modify the methylation of placental DNA. Thus, changes in the placental methylation pattern act as a “record” of intrauterine exposure to various environmental factors.
At BiSC we want to study:
1) The impact of exposure to different environmental factors during pregnancy on the epigenome of the placenta.
2) The possible intermediate role of the placental epigenome in the impact of environmental factors on child health.
3) The use of the placental epigenome as a biomarker to predict the health of the child and the risk of suffering from certain diseases throughout life.
Last fall, BiSC researchers conducted a series of pilot studies on a subset of placenta samples. The result showed that the quantity and quality of the genetic material (DNA and RNA) isolated from the stored placental samples of BiSC is good enough to carry out the study of the molecular profiles of this tissue, including the study of its epigenome. So, in March, we will start extracting DNA and RNA from all the samples and if all goes well we will be able to count on this very relevant information soon!
The Lab in which we conduct the DNA and RNA extraction at the Biomedical Research Park of Barcelona (PRBB).
The text has been written by Marta Cosin, a postdoctoral researcher of the BiSC project.