Pregnancy is a special period not only because of the beauty of the formation of a new organism but also due to the physiological and biological changes brought about by cellular multiplication and specialization. Even more interesting are the different epigenetic patterns that can be sculpted during this phase, modulating the gene programs of each cell throughout this new organism.
These epigenetic patterns are dynamic and can be altered according to environmental stimuli early in life, even causing phenotypic and behavioral changes in adulthood. Thus, during pregnancy, the fetus's epigenome is sensitive, for example, to maternal nutrition, exposure to toxins, as well as physiological stress [1]. Even more interesting is the possibility of the transposition of paternal environmental and behavioral patterns to their offspring. That's right, attention future dads! Not only your hair and eye color but also your lifestyle can impact your children's health.
It was precisely in 2010 that Ng and collaborators demonstrated the transgenerational transmission of characteristics, contributing to the development of diabetes. A parental exposure of male rats to a high-fat diet could induce an early imbalance of insulin-glucose homeostasis in the females of their offspring, due to dysfunction in pancreatic beta cells.
Obesity in adulthood also seems to be associated with adverse experiences suffered in childhood, such as maternal antipathy and neglect [2].
These findings show us the importance of considering the parental role in the emergence and early development of certain diseases like diabetes.
However, not only during the prenatal period but also in the neonatal and childhood stages, factors such as parental care can amplify the effects of epigenetic modifications that will occur in the adult individual. For example, a rat pup that received more parental care, such as licking and carrying, during the early life phase shows increased expression of the gene that encodes the glucocorticoid receptor in the hippocampus in adulthood. Furthermore, this pup shows differences in DNA methylation compared to pups from mothers with lower care habits. This increased gene expression contributes to a less exacerbated stress response, highlighting the important role of the environment in the early stages of life in shaping the physiological reactions of the organism [3].
It is important to emphasize that this plasticity demonstrated by epigenetics indicates that changes in habits can also have a positive influence on the modulation of development as well as in attempts to prevent the development of diseases in future generations.
Since these epigenetic modifications are reversible and activate specific signaling pathways, a detailed understanding of the mechanisms of action provides a potential platform for pharmacological and therapeutic manipulations that could act in other treatments beyond those already studied, such as for cancer and psychiatric conditions [4].
Certainly, these studies deserve careful analysis, as many variables need to be isolated to confirm a direct cause-and-effect relationship. But on the other hand, all this data helps us think about how important it is to take care of a life in formation, not only to maintain its physical integrity but also to ensure that its psychological and physiological integrity is formed in the best possible way, which is its right.
After presenting the role of epigenetics in our lives, literally, I think it is important to end this discussion with a quote from researcher Marcus Pembrey, so that we reflect on how we should approach the genome and epigenome in future studies: “We must live as guardians of our genome. We must take care of it because it does not only represent you.”
References
[1] Szyf M, Weaver I, Meaney M. Maternal care, the epigenome and phenotypic differences in behavior. Reprod Toxicol. 2007 Jul;24(1):9-19. Epub 2007 May 10
[2] Vámosi ME, Heitmann BL, Thinggaard M, Kyvik KO. Parental care in childhood and obesity in adulthood: a study among twins. Obesity (Silver Spring). 2011 Jul;19(7):1445-50. doi: 10.1038/oby.2011.20. Epub 2011 Feb 17.
[3] Weaver IC, Cervoni N, Champagne FA, D'Alessio AC, Sharma S, Seckl JR, Dymov S,Szyf M, Meaney MJ. Epigenetic programming by maternal behavior. Nat Neurosci. 2004 Aug;7(8):847-54. Epub 2004 Jun 27.
[4] McGowan PO, Szyf M. The epigenetics of social adversity in early life: implications for mental health outcomes. Neurobiol Dis. 2010 Jul;39(1):66-72. Epub 2010 Jan 4.
Ng SF, Lin RC, Laybutt DR, Barres R, Owens JA, Morris MJ. Chronic high-fat diet in fathers programs β-cell dysfunction in female rat offspring. Nature. 2010 Oct 21;467(7318):963-6.
