Epigenetic regulation of histone modifications and Gata6 gene expression induced by maternal diet in mouse embryoid bodies in a model of developmental programming.

Congshan Sun,Bhavwanti Sheth,Tom P Fleming,Oleg Denisenko,Neil R Smyth,Emma S Lucas,Andy Cox

doi:10.1186/s12861-015-0053-1

Congshan Sun, Bhavwanti Sheth + Show 5 more

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https://doi.org/10.1186/s12861-015-0053-1

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Abstract

BackgroundDietary interventions during pregnancy alter offspring fitness. We have shown mouse maternal low protein diet fed exclusively for the preimplantation period (Emb-LPD) before return to normal protein diet (NPD) for the rest of gestation, is sufficient to cause adult offspring cardiovascular and metabolic disease. Moreover, Emb-LPD blastocysts sense altered nutrition within the uterus and activate compensatory cellular responses including stimulated endocytosis within extra-embryonic trophectoderm and primitive endoderm (PE) lineages to protect fetal growth rate. However, these responses associate with later disease. Here, we investigate epigenetic mechanisms underlying nutritional programming of PE that may contribute to its altered phenotype, stabilised during subsequent development. We use embryonic stem (ES) cell lines established previously from Emb-LPD and NPD blastocysts that were differentiated into embryoid bodies (EBs) with outer PE-like layer.ResultsEmb-LPD EBs grow to a larger size than NPD EBs and express reduced Gata6 transcription factor (regulator of PE differentiation) at mRNA and protein levels, similar to Emb-LPD PE derivative visceral yolk sac tissue in vivo in later gestation. We analysed histone modifications at the Gata6 promoter in Emb-LPD EBs using chromatin immunoprecipitation assay. We found significant reduction in histone H3 and H4 acetylation and RNA polymerase II binding compared with NPD EBs, all markers of reduced transcription. Other histone modifications, H3K4Me2, H3K9Me3 and H3K27Me3, were unaltered. A similar but generally non-significant histone modification pattern was found on the Gata4 promoter. Consistent with these changes, histone deacetylase Hdac-1, but not Hdac-3, gene expression was upregulated in Emb-LPD EBs.ConclusionsFirst, these data demonstrate ES cells and EBs retain and propagate nutritional programming adaptations in vitro, suitable for molecular analysis of mechanisms, reducing animal use. Second, they reveal maternal diet induces persistent changes in histone modifications to regulate Gata6 expression and PE growth and differentiation that may affect lifetime health.

Highlights

Dietary interventions during pregnancy alter offspring fitness
Effect of maternal diet on embryoid body (EB) size embryonic stem (ES) cells derived from blastocysts collected from EmbLPD and normal protein diet (NPD) females were maintained from passage 6 for 5.5 days in culture for EB formation in 96-well low adhesion plate culture
We investigated the expression of Gata4 and Gata6 and the downstream target gene, Dab2 in EmbLPD and NPD EBs

Summary

Introduction

Dietary interventions during pregnancy alter offspring fitness. We have shown mouse maternal low protein diet fed exclusively for the preimplantation period (Emb-LPD) before return to normal protein diet (NPD) for the rest of gestation, is sufficient to cause adult offspring cardiovascular and metabolic disease. Periconceptional environment, especially during oocyte maturation and preimplantation development, can influence the pattern of later gestation leading to permanent changes in offspring growth, physiology, health and disease risk through to adulthood [1,2,3] Factors such as the quality and composition of maternal or paternal diet, parental metabolism and health, or specific conditions as used in assisted conception such as embryo culture, can all influence the developmental programme. We have used a rodent maternal low protein diet model to study mechanisms of periconceptional programming whereby protein restriction is applied exclusively during the period from mating to blastocyst formation (EmbLPD, 9% casein, E0-3.5 in mouse) with normal nutrition (NPD, 18% casein) provided for the remainder of gestation, and standard chow diet postnatally This brief nutritional challenge is sufficient to induce cardiometabolic dysfunction, hypertension and abnormal behaviour in adulthood [8,9]. Nutrient provision and growth promotion resulting from these extraembryonic adaptations to poor maternal diet, whilst likely favouring competitive fitness of offspring during periods of limited food supply, lead to later chronic disease when the diet improves, evidenced by the resulting perinatal weight correlating with adult CV and behavioural dysfunction [9]

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