Children of traumatized people often suffer from illnesses. Brain researchers from Zurich have discovered that people with trauma pass their health problems on to their offspring through blood.
Through experiments on mice, a team from the Brain Research Institute of the University of Zurich (UZH) demonstrated that the first traumatic experiences had an effect on the composition of the blood. The researchers found significant differences between the blood of traumatized animals and that of a control group raised normally.
Particularly striking are the changes in fat metabolism. These changes were then also seen in the offspring of traumatized animals, who themselves developed symptoms related to these trauma, according to the study published Friday by UZH. “Impressive proof that blood transmits stress messages to germ cells,” we read.
In children as in mice
The researchers looked to see if similar effects could occur in humans. To do this, they analyzed the blood and saliva of 25 children taken in by SOS Children’s Villages in Pakistan who had lost their father and had grown up far from their mother.
“The traumatic experiences of these children are comparable to those experienced by our mouse model and their metabolism shows similar changes in the blood,” explains Isabelle Mansuy, professor of neuroepigenetics at the Brain Research Institute of UZH and Institute of Neurosciences of the Swiss Federal Institute of Technology Zurich (ETHZ).
In other experiments, the team discovered a molecular mechanism by which factors in changes in fat metabolism transmit signals to germ cells. The PPAR receptor, located on the surface of cells, plays a key role in this process.
It is activated by fatty acids and regulates gene expression and DNA structure in many tissues. And the indicators of said receptor are higher in the semen of traumatized mice.
Artificial activation of the receptor also resulted in weight loss and impaired sugar metabolism in male mice and their offspring. From these and other experiments, the researchers conclude that activation of the PPAR receptor by fatty acids in sperm plays an important role in the transmission of the metabolic effects induced by the trauma.
“Our results show that trauma suffered early in life affects not only mental health but also physical health in adulthood over several generations,” says Isabelle Mansuy. A better knowledge of the biological processes at the origin of this state of affairs could in the future help to prevent the late consequences of trauma.
DOI: 10.15252 / embj.2020104579