In pregnancy, the placenta is the link between mother and child, and this prenatal environment can have huge influences on the development of the fetus. Changes in the intrauterine environment have been associated with cardiovascular, metabolic, and neurodevelopmental disorders. Decades ago, scientists began to investigate the association between problems in fetal development and schizophrenia. Researchers sought to learn more about whether this connection can be traced to changes with chemical groups that attach to the genome, or methylation.
Epigenetic changes can affect gene expression but they do not alter the sequence of DNA. Instead, epigenetics can work through structural changes in the genome, or the attachment or removal of methyl groups. Methylation is one crucial method the cell can use to control gene expression, and methyl groups can be altered by environmental conditions like stress, diet, or pollutants, for example.
Reporting in Nature Communications, researchers have now demonstrated a link between placental DNA methylation and several neuropsychiatric diseases: bipolar disorder, major depressive disorder, and schizophrenia. However, virtually no association was found between placental DNA methylation and attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD).
The researchers also noted that major depression is a more complex disorder from a genetic perspective than bipolar disorder or schizophrenia, and the link between depression and placental DNA methylation is not as clear as the other disorders.
"These findings reinforce the hypothesis that schizophrenia and other disorders have a neurodevelopmental origin and that the placenta plays a fundamental role in this process," noted corresponding study author Dr. Nora Fernandez-Jimenez, assistant professor at the University of the Basque Country (UPV/EHU), among other appointments.
"If we could identify risk factors at the prenatal stage, we could intervene before symptoms appear, adjusting treatments or designing personalized preventive strategies," added first study author Dr. Ariadna Cilleros-Portet, currently of Mount Sinai Hospital.
While scientists are still working to learn the cause of complex psychological disorders like schizophrenia, this study has shown that influences that arise very early in development could have a significant effect on a disorder that may not arise until decades later. Knowing more about the basis of such illnesses will help scientists create better therapeutics or potentially, preventive measures.
Sources: University of Basque Country, Nature Communications
