Short communicationAlcohol exposure impairs trophoblast survival and alters subtype-specific gene expression in vitro
Introduction
Maternal perturbations during early pregnancy, including a low protein diet [1], [2], [3], undernutrition [4], [5], or alcohol (EtOH) exposure [6], [7], can result in fetal growth restriction and programming of adult disease. Alcohol is a common exposure during pregnancy, with current statistics being 47–58% of all pregnancies [11], [12]. Consumption of 5+ standard drinks has also been reported in the period prior to pregnancy recognition (14%) [11], [12]. In vivo rodent models of EtOH exposure during the periconception period [6] and intermittently throughout gestation [13], [14], have shown alterations to placental structure and expression of metabolic transporters. This is of interest as normal formation and function of the placenta is a critical determinant of fetal growth. Derived from the trophectoderm of the pre-implantation embryo, trophoblast cells contribute the majority of cells within the mature placenta and consist of a number of unique cell types with diverse morphologies and functions [8], [9]. The definitive chorioallantoic placenta is organised into two zones containing specialised trophoblast cell types; the junctional zone which has a structural and endocrine role, while the labyrinth zone contains the fetal and maternal vasculature and is the location of nutrient exchange [10]. Perturbations during pregnancy often result in modifications to placental growth [2], [5] and zonal allocation [6] in late gestation, however few studies have determined whether alterations to trophoblast differentiation in early pregnancy may be mediating these effects. We have previously reported that periconceptional EtOH exposure prior to implantation in the rat causes an increase in glycogen trophoblasts (GlyT) in the junctional zone during late gestation [6]. In addition, high dose (18–37% vol/vol) EtOH exposure from implantation until close to term (E6-E18) reduced invasion of trophoblast cells into the maternal decidua and caused labyrinth disorganisation [14]. However, it is unknown if placental defects are due to direct exposure of the trophoblast stem cells of the trophectoderm to EtOH within the uterine cavity, or via other indirect mechanisms such as interactions with altered uterine cells. Here we utilise an in vitro model of differentiating mouse trophoblast stem (TS) cells to examine the direct effects of EtOH on proliferation and differentiation.
Section snippets
TS cell culture
Murine TS cells (EGFP line) were maintained as previously described [15]. Cells were seeded at 5 × 104, and differentiated in 0% (control), 0.2%, or 1% EtOH in TS media. To assess cell proliferation, cells were lifted off the culture plates and counted using a hemocytometer on days 2, 4 and 6 of culture (N = 3/treatment). Gene expression analysed on day 6 (N = 9/treatment, 3 technical replicates per set). Media was changed every 2 days including the addition of fresh EtOH. The 0.2% EtOH dose
Results and discussion
To determine the mechanism by which EtOH exposure during early pregnancy may be mediating altered placental growth and function, we explored the direct impact of EtOH on TS cell proliferation and differentiation. To investigate EtOH exposure at a physiological level, 0.2% EtOH was chosen as this was the peak blood alcohol content found in a model of in vivo alcohol exposure in the rat at 30 min after initial consumption [6]. In addition, 0.2% EtOH is also the maximum dose that the TS cells
Statement of interest
None.
Conflict of interest
The authors have no conflicts to disclose.
Acknowledgments
JIK and JEO are recipients of Australian Postgraduate Award scholarships. KMM is a Senior Research Fellow of the NHMRC. This study was supported by a grant from the National Health & Medical Research Council of Australia (APP1046137).
References (24)
- et al.
Maternal undernutrition during the preimplantation period of rat development causes blastocyst abnormalities and programming of postnatal hypertension
Development
(2000) - et al.
Imprinted gene expression in the rat embryo-fetal axis is altered in response to periconceptional maternal low protein diet
Reproduction
(2006) - et al.
Maternal low protein diet restricted to the preimplantation period induces a gender-specific change on hepatic gene expression in rat fetuses
Mol. Reprod. Dev.
(2007) - et al.
Impact of maternal undernutrition during the periconceptional period, fetal number, and fetal sex on the development of the hypothalamo-pituitary adrenal axis in sheep during late gestation
Biol. Reprod.
(2002) - et al.
Periconceptional nutrition and the relationship between maternal body weight changes in the periconceptional period and feto-placental growth in the sheep
J. Physiol.
(2005) - et al.
Periconceptional alcohol consumption causes fetal growth restriction and increases glycogen accumulation in the late gestation rat placenta
Placenta
(2014) - et al.
Maternal alcohol intake around the time of conception causes glucose intolerance and insulin insensitivity in rat offspring, which is exacerbated by a postnatal high-fat diet
FASEB J.
(2015) - et al.
Diverse subtypes and developmental origins of trophoblast giant cells in the mouse placenta
Dev. Biol.
(2007) - et al.
Implantation and the placenta: key pieces of the development puzzle
Science
(1994) - et al.
Developmental dynamics of the definitive mouse placenta assessed by stereology
Biol. Reprod.
(2004)
Alcohol consumption during pregnancy in nonindigenous west Australian women
Alcohol Clin. Exp. Res.
Substance use, psychological distress and violence among pregnant and breastfeeding Australian women
Aust. N. Z. J. Public Health
Cited by (19)
Epigenetic regulation during placentation
2020, Epigenetics and Reproductive HealthLive-cell imaging in Trichoderma
2020, New and Future Developments in Microbial Biotechnology and Bioengineering: Recent Developments in Trichoderma ResearchOral vitamin B1-substitution does not decrease genetically determined cleft rate in mice (A/WySn)
2017, Journal of Cranio-Maxillofacial SurgeryCitation Excerpt :One of the possible explanations for such results could be the altered metabolism of thiamine, including thiamine transport and/or intake, as well as morphological changes in the placenta. It is worth noting that the influence of maternal diet on protein expression in embryo trophoblasts and later in placenta structure and metabolic transporter expression was demonstrated in rodent models exposed to ethanol (EtOH) during the periconceptional period (Kalisch-Smith et al., 2016). Further investigations within the ThTr-2 expression in the mouse placenta revealed a changed localization of the ThTr-2 receptor.
First trimester alcohol exposure alters placental perfusion and fetal oxygen availability affecting fetal growth and development in a non-human primate model
2017, American Journal of Obstetrics and GynecologyCitation Excerpt :Therefore, although ethanol has been shown to reduce acutely fetal and maternal blood flow to the placenta in humans and other animal models,6-8 the alterations to placental function observed here more likely result from longer-term developmental consequences of ethanol exposure during the periconceptional period. Previous rodent studies have identified the influence of periconceptional ethanol exposure on subsequent trophoblast survival, gene expression, and zonal distribution at later gestational ages.32,33 Notably, in rodents, ethanol exposure early in pregnancy is associated with reduced trophoblast invasion of the spiral arteries and altered placental vascular development that is associated with impaired fetal growth.34-36