Fetal programming and lactation: modulating gene expression in response to undernutrition during intrauterine life.

Abstract

Adverse environmental conditions during intrauterine life, known as fetal programming, significantly contribute to the development of diseases in adulthood. Fetal programming induced by factors like maternal undernutrition leads to low birth weight and increases the risk of cardiometabolic diseases. We studied a rat model of maternal undernutrition during gestation (MUN) to investigate gene expression changes in cardiac tissue using RNA-sequencing of day 0-1 litters. Moreover, we analyzed the impact of lactation at day 21, in MUN model and cross-fostering experiments, on cardiac structure and function assessed by transthoracic echocardiography, and gene expression changes though qPCR. Our analysis identified specific genes with altered expression in MUN rats at birth. Two of them, Agt and Pparg, stand out for being associated with cardiac hypertrophy and fibrosis. At the end of the lactation period, MUN males showed increased expression of Agt and decreased expression of Pparg, correlating with cardiac hypertrophy. Cross-fostering experiments revealed that lactation with control breastmilk mitigated these expression changes reducing cardiac hypertrophy in MUN males. Our findings highlight the interplay between fetal programming, gene expression, and cardiac hypertrophy suggesting that lactation period is a potential intervention window to mitigate the effects of fetal programming. Heart remodeling involves the alteration of several groups of genes and lactation period plays a key role in establishing gene expression modification caused by fetal programming. We could identify expression changes of relevant genes in cardiac tissue induced by undernutrition during fetal life. We expose the contribution of the lactation period in modulating the expression of Agt and Pparg, relevant genes associated with cardiac hypertrophy. This evidence reveal lactation as a crucial intervention window for preventing or countering fetal programming.