The placenta: transcriptional, epigenetic, and physiological integration during development

Abstract

The placenta provides critical transport functions between the maternal and fetal circulations during intrauterine development. Formation of this interface relies on coordinated interactions among transcriptional, epigenetic, and environmental factors. Here we describe these mechanisms in the context of the differentiation of placental cells (trophoblasts) and synthesize current knowledge about how they interact to generate a functional placenta. Developing an understanding of these pathways contributes to an improvement of our models for studying trophoblast biology and sheds light on the etiology of pregnancy complications and the in utero programming of adult diseases.

Concepts and Mechanisms: Crossing Host Barriers

“…The amniotic epithelium forms the maternofetal interface in the chorioamnion. The apical surface of this epithelium is exposed to amniotic fluid, whereas its basal surface sits on a basement membrane that overlies the amniotic mesoderm (Cross et al 1994;Huppertz 2008;Maltepe et al 2010).…”

Trophoblastic vasculogenic mimicry in gestational choriocarcinoma

“…[6][7][8] The identification and characterization of the genes expressed in human trophoblast have enhanced our understanding of the lineage and differentiation program of trophoblast and its relationship to trophoblastic tumors and tumor-like lesions. 9 Molecularly, several genes and pathways have been reported to participate in the pathogenesis of choriocarcinoma.…”

Evaluation of Placental Epigenetic Changes due to Morphine Consumption

“…Morphine is a meddlesome factor in normal embryonic development, and the mother's dependency to opiates is a growing concern because of various epigenetic factors including stress. Addiction is a universal problem that curtails the health of mothers and the developing embryos (Maltepe et al, 2010;Maccani & Marsit, 2009;Renthal & Nestler, 2008). In regards to this point, the placenta is an initial barrier for the embryo against morphine.…”

“…The role of epigenetic factors in the regulation of placental growth and development starts before implantation. Epigenetic factors such as DNA methylation, histone alternations and nontranscriptional RNAs, are effective in driving gene expression patterns, and these changes have a pivotal role in the genesis of the embryo and placenta (Maltepe et al, 2010;Maccani & Marsit). Organism development from a singleegg to adulthood includes a set of pre-programmed and differentiation processes.…”

“…Trophoblastic cell differentiation to embryonic mass and placenta is influenced by epigenetic factors (Rozisky et al, 2012;Russ et al, 2000). Malnutrition causes an increase in the mother's blood sugar (even temporary) and may affect gene transcription of embryo and mother communicating trophoblastic cells; in this way, insulin cannot pass into the placenta but excess glucose into the placenta can increase the infant's blood sugar (Aronow et al, 2001;DeChiara et al;Maltepe et al, 2010). The total amount of DNA methylation changes in opiate dependency differs between embryo and extra-embryo.…”