Washington DC. [USA]Another study suggests that, like other animals, humans can be prepared through epigenetic changes to cope with the environment their mother experienced during pregnancy.
A new human study shows that in high-violence communities where children experience prenatal stress, psychiatric problems appear to be less frequent – and a different, potentially protective, pattern of epigenetic changes emerges.
"In animals, in some circumstances, exposure of pregnant mothers to predators leads to behavioral and molecular changes in the offspring, which are beneficial in environments rich in predators, but not otherwise. A similar relationship between prenatal and postnatal stress may help explain why some individuals develop psychiatric problems while others seem resilient, "said lead author Daniel Nätt.
The team of researchers speculated that in high-violence communities, stress during pregnancy will have different consequences than those reported in studies of less violent communities.
"Brazilian families participating in our study were exposed to high levels of community violence, such as gang violence. Exposure to violence was also high within families, including, for example, intimate partners, "Nätt said.
According to the researchers, this intimate partner violence (IPV) was relatively maintained during gestations in this cohort, which is a sensitive period for both mother and child.
The results were published in the Journal of Frontiers in Genetics
To test their hypothesis, the researchers analyzed interviews and saliva samples from 120 mothers and 120 of their children.
"In addition to evaluating psychiatric profiles, we evaluated DNA methylation in saliva cells. DNA methylation is a type of epigenetic change that changes the way genes are expressed without modifying the genetic code. Based on previous studies, DNA methylation is believed to be involved in the modeling of psychiatric resilience after stress in early life, "said Nätt.
Prenatal stress seems to interact with postnatal stress to influence resilience
The results showed that the more mothers were exposed to IPV during pregnancy, the worse they suffered from depression, PTSD and anxiety symptoms. However, the way this affected the children of abused mothers differed from many other studies.
"The children interviewed showed fewer psychiatric consequences of prenatal stress than those reported repeatedly in less violent populations," Nätt said.
According to the researchers, although the results require more validation, since they are based on only one Brazilian cohort, in this cohort, they have been able to replicate other studies showing that children with maternal IPV after birth have more psychiatric problems.
Only when maternal IPV occurred during and after pregnancy, these psychiatric problems were less severe. Thus, the prenatal component seems to have played a role here, the researchers explained.
DNA methylation may mediate the adaptation of the stress response in early development
The researchers also noted that several well-known stress genes, such as the glucocorticoid receptor and its repressor protein FKBP51, which regulate one of our most important stress hormones, cortisol, were among the most differentially methylated.
The way these genes were methylated suggested that children who were stressed in the prenatal period had an increased ability to end stress responses.
Taken together, these results imply that prenatal stress may be involved – through changes in DNA methylation – in modeling psychiatric resilience. Nätt, however, is very clear that the findings should be scrutinized by others.
"For example, prenatal stress has been associated with increased social behavior and risk for autism spectrum disorder. In other communities, the same behavioral traits can be a benefit to you. In the violent communities we study, having social "skills", for example, being able to block the emotional consequence of seeing and executing violence, can be of benefit to you. It may even make you climb the social ladder, which would probably make you feel better, "Nätt explained.
Researchers suggest that the results of this study may provide a warning to many violent and non-violent communities. Violent communities to promote such violent behaviors, and nonviolent communities for not giving enough support to individuals who leave standards. (ANI)