Maternal-fetal Interactions Research Articles

Angiogenic Properties of Placenta-Derived Extracellular Vesicles in Normal Pregnancy and in Preeclampsia.

Angiogenesis is one of the main processes that coordinate the biological events leading to a successful pregnancy, and its imbalance characterizes several pregnancy-related diseases, including preeclampsia. Intracellular interactions via extracellular vesicles (EVs) contribute to pregnancy’s physiology and pathophysiology, and to the fetal–maternal interaction. The present review outlines the implications of EV-mediated crosstalk in the angiogenic process in healthy pregnancy and its dysregulation in preeclampsia. In particular, the effect of EVs derived from gestational tissues in pro and anti-angiogenic processes in the physiological and pathological setting is described. Moreover, the application of EVs from placental stem cells in the clinical setting is reported.

Maternal serotonin transporter genotype and offsprings' clinical and cognitive measures of ADHD and ASD

Serotonin (5-HT) is an important factor for prenatal neurodevelopment whereby its neurotrophic actions can be regulated through maternal-fetal interactions. We explored if maternal 5-HTTLPR genotype is associated with clinical and cognitive measures of attention-deficit/hyperactivity disorder (ADHD) and comorbid autism spectrum disorder (ASD) in typically-developing and ADHD-diagnosed offspring, beyond classical inheritance and environmental- and comorbidity-mediators/confounders. Family-based variance decomposition analyses were performed incorporating 6–31 year-old offsprings' as well as parental genotypes of 462 ADHD and control families from the NeuroIMAGE cohort. Dependent measures were offsprings' ADHD symptom- and ASD trait-scores and cognitive measures including executive functioning (including response inhibition and cognitive flexibility), sustained attention, reward processing, motor control, and emotion recognition. Offsprings' stereotyped behavior was predicted by an interaction between maternal 5-HTTLPR genotype and offsprings' sex. Furthermore, offspring of mothers with low-expressing genotypes demonstrated larger reward-related reductions in reaction time. While specifically adult male offspring of these mothers reported a faster reversal learning with less errors, specifically young female offspring of these mothers were more accurate in identifying happy faces. Adult offspring from the mothers with low-expressing 5-HTTLPR genotypes were also slower in identifying happy faces. However, this association seemed to be mediated by offsprings' high anxiety levels. In sum, we found some support for a role of the maternal 5-HT system in modulating fetal brain development and behavior. Offsprings' cognitive measures might be more sensitive to small alterations within the maternal 5-HT system than their ADHD and ASD clinical phenotypes. Further studies are needed to specify the association between maternal genotype and risk for neurodevelopmental disorders.

Single-Cell RNA-Seq of Mouse Decidual Leukocytes Reveals Intriguing Gestational Changes in the Immune Cell Landscape and Effects of SRC-1/-2 Double-Deficiency

Single-cell RNA-seq of Mouse Decidual Leukocytes Reveals Intriguing Gestational Changes in the Immune Cell Landscape and Effects of SRC-1/-2 Double-DeficiencyOur previous findings suggest that the fetus signals the mother when it is ready to be born through secretion of surfactant components/immune modulators, surfactant protein A (SP-A) and platelet-activating factor (PAF) by the fetal lung into amniotic fluid (AF). This occurs with increased proinflammatory cytokine expression by fetal AF macrophages (Mϕ), increased myometrial NF-κB activation and contractile (CAP) gene expression. Steroid receptor coactivator (Src)-1 and Src-2 are critical for developmental induction SP-A and PAF by the fetal lung. The finding that pregnant wild-type (WT) mice carrying Src-1 and Src-2 double-deficient fetuses (Src-1/-2d/d) manifested a marked delay (~38h) in parturition, further suggests that signals for parturition arise from the fetus and that Src-1 and Src-2 serve a critical role. Infiltrating leukocytes at the maternal-fetal interface (MFI)/decidua are known to play a central role in pregnancy maintenance and parturition timing. However, there is limited knowledge regarding gestational changes in immune cell composition toward term. To analyze gestational changes in the composition of immune cells within decidua and effects of Src-1/-2d/d, we conducted single-cell RNA-seq of ~17,000 decidual leukocytes (CD45+) from pregnant mice at 15.5 and 18.5 dpc carrying WT or Src-1/-2d/d fetuses. Unsupervised clustering identified 22 distinct decidual immune cell clusters, comprised of Mϕ, B cells, natural killer cells, neutrophils, dendritic cells and monocytes. Significant differences in cell type composition and transcriptional profiles were found across study groups (WT @ 15.5 dpc vs. 18.5 dpc; Src-1/-2d/dvs. WT @15.5 dpc and 18.5 dpc). Interestingly, in deciduas of pregnant mice carrying WT fetuses, Mϕ and B cell clusters markedly increased between 15.5 and 18.5 dpc, whereas, neutrophils declined; however, these gestational changes did not occur in pregnant mice carrying Src-1/-2d/d fetuses. Differential gene expression and gene ontology enrichment analyses revealed specific gene expression patterns distinguishing these immune cell subtypes to uncover their putative functions. These findings highlight the complexity and dynamics of the decidual immune cell landscape during the transition from myometrial quiescence to contractility, and the fetal-maternal interactions leading to parturition. Support: NIH grants R01-HL050022 (CRM) and P01-HD087150 (CRM), Burroughs Wellcome Preterm Birth Grant #1019823 (CRM).

Evolutionary transcriptomics implicates HAND2 in the origins of implantation and regulation of gestation length

The developmental origins and evolutionary histories of cell types, tissues, and organs contribute to the ways in which their dysfunction produces disease. In mammals, the nature, development and evolution of maternal-fetal interactions likely influence diseases of pregnancy. Here we show genes that evolved expression at the maternal-fetal interface in Eutherian mammals play essential roles in the evolution of pregnancy and are associated with immunological disorders and preterm birth. Among these genes is HAND2, a transcription factor that suppresses estrogen signaling, a Eutherian innovation allowing blastocyst implantation. We found dynamic HAND2 expression in the decidua throughout the menstrual cycle and pregnancy, gradually decreasing to a low at term. HAND2 regulates a distinct set of genes in endometrial stromal fibroblasts including IL15, a cytokine also exhibiting dynamic expression throughout the menstrual cycle and gestation, promoting migration of natural killer cells and extravillous cytotrophoblasts. We demonstrate that HAND2 promoter loops to an enhancer containing SNPs implicated in birth weight and gestation length regulation. Collectively, these data connect HAND2 expression at the maternal-fetal interface with evolution of implantation and gestational regulation, and preterm birth.

The Hypothalamic-Pituitary-Adrenal Axis: Development, Programming Actions of Hormones, and Maternal-Fetal Interactions.

The hypothalamic-pituitary-adrenal axis is a complex system of neuroendocrine pathways and feedback loops that function to maintain physiological homeostasis. Abnormal development of the hypothalamic-pituitary-adrenal (HPA) axis can further result in long-term alterations in neuropeptide and neurotransmitter synthesis in the central nervous system, as well as glucocorticoid hormone synthesis in the periphery. Together, these changes can potentially lead to a disruption in neuroendocrine, behavioral, autonomic, and metabolic functions in adulthood. In this review, we will discuss the regulation of the HPA axis and its development. We will also examine the maternal-fetal hypothalamic-pituitary-adrenal axis and disruption of the normal fetal environment which becomes a major risk factor for many neurodevelopmental pathologies in adulthood, such as major depressive disorder, anxiety, schizophrenia, and others.

Placental trophoblast syncytialization potentiates macropinocytosis via mTOR signaling to adapt to reduced amino acid supply

During pregnancy, the appropriate allocation of nutrients between the mother and the fetus is dominated by maternal-fetal interactions, which is primarily governed by the placenta. The syncytiotrophoblast (STB) lining at the outer surface of the placental villi is directly bathed in maternal blood and controls feto-maternal exchange. The STB is the largest multinucleated cell type in the human body, and is formed through syncytialization of the mononucleated cytotrophoblast. However, the physiological advantage of forming such an extensively multinucleated cellular structure remains poorly understood. Here, we discover that the STB uniquely adapts to nutrient stress by inducing the macropinocytosis machinery through repression of mammalian target of rapamycin (mTOR) signaling. In primary human trophoblasts and in trophoblast cell lines, differentiation toward a syncytium triggers macropinocytosis, which is greatly enhanced during amino acid shortage, induced by inhibiting mTOR signaling. Moreover, inhibiting mTOR in pregnant mice markedly stimulates macropinocytosis in the syncytium. Blocking macropinocytosis worsens the phenotypes of fetal growth restriction caused by mTOR-inhibition. Consistently, placentas derived from fetal growth restriction patients display: 1) Repressed mTOR signaling, 2) increased syncytialization, and 3) enhanced macropinocytosis. Together, our findings suggest that the unique ability of STB to undergo macropinocytosis serves as an essential adaptation to the cellular nutrient status, and support fetal survival and growth under nutrient deprivation.

Application of Carbon-13 Isotopomer Analysis to Assess Perinatal Myocardial Glucose Metabolism in Sheep.

Ovine models of pregnancy have been used extensively to study maternal–fetal interactions and have provided considerable insight into nutrient transfer to the fetus. Ovine models have also been utilized to study congenital heart diseases. In this work, we demonstrate a comprehensive assessment of heart function and metabolism using a perinatal model of heart function with the addition of a [U-13C]glucose as tracer to study central energy metabolism. Using nuclear magnetic resonance spectroscopy, and metabolic modelling, we estimate myocardial citric acid cycle turnover (normalized for oxygen consumption), substrate selection, and anaplerotic fluxes. This methodology can be applied to studying acute and chronic effects of hormonal signaling in future studies.

Preeclampsia: inflammatory signature of decidual cells in early manifestation of disease

IntroductionPreeclampsia is a pregnancy-specific complication characterized by hypertension in combination with proteinuria and/or various manifestations of multiple organ failure. It is believed that etiology of preeclampsia lies in dysfunction of the placenta and disorder of the maternal-fetal interactions. In preeclampsia decidual membrane, the maternal part of the placenta which normally supports immunological tolerance of the maternal organism to the semi-allogeneic fetus, becomes a site of inflammation. MethodsThe aim of our study was to characterize the phenotype of decidual macrophages and plasma profiles in patients with late- and early-onset preeclampsia as compared with controls (n = 43). Decidual cells were obtained by enzymatic digestion method and characterized by flow cytometry analysis, real-time PCR, bioinformatics analysis, immunohistochemistry, and Western blot. Plasma samples were analyzed by multiplex assay. ResultsThe number of inflammation-associated CD86+ and CX3CR1+ cells was significantly higher in the early-onset preeclampsia while the portion of CD163+ cells was significantly higher among studied groups. We observed significant increase of endothelin-1 gene expression and a significant decrease in eNOS and GNB3 expression and TGFβ relative protein level in decidual cells of the early-onset preeclampsia samples. We also revealed elevation of pro- and anti-inflammatory cytokines in plasma of preeclampsia groups. DiscussionOur findings reflect profound early-onset preeclampsia-associated alterations in the decidua and emphasize the importance of the decidua as a link in the development of preeclampsia.

Joint Associations of Maternal-Fetal APOL1 Genotypes and Maternal Country of Origin With Preeclampsia Risk

Preeclampsia, which disproportionately affects Black women, is a leading cause of preterm delivery and risk for future hypertension and chronic kidney disease (CKD). Apolipoprotein L1 (APOL1) kidney risk alleles, common among Black individuals, contribute substantially to CKD disparities. Given the strong link between preeclampsia and CKD, we investigated whether maternal and fetal APOL1 risk alleles can jointly influence preeclampsia risk, and explored potential modifiers of the association between APOL1 and preeclampsia. Nested case-control study. 426 Black mother-infant pairs (275 African Americans and 151 Haitians) from the Boston Birth Cohort. Maternal and fetal APOL1 risk alleles. Preeclampsia. Logistic regression models with adjustment for demographic characteristics were applied to analyze associations between fetal and maternal APOL1 risk alleles and risk of preeclampsia and to investigate the effects of modification by maternal country of origin. Fetal APOL1 risk alleles tended to be associated with an increased risk of preeclampsia, which was not statistically significant in the total genotyped population. However, this association was modified by maternal country of origin (P<0.05 for interaction tests): fetal APOL1 risk alleles were significantly associated with an increased risk of preeclampsia among African Americans under recessive (odds ratio [OR], 3.6 [95% CI, 1.3-9.7]; P=0.01) and additive (OR, 1.7 [95% CI, 1.1-2.6]; P=0.01) genetic models but not in Haitian Americans. Also, maternal-fetal genotype discordance at the APOL1 locus was associated with a 2.6-fold higher risk of preeclampsia (P<0.001) in African Americans. Limited sample size in stratified analyses; self-reported maternal country of origin; pre-pregnancy estimated glomerular filtration rate (eGFR) and proteinuria data in mothers were not collected; unmeasured confounding social and/or environmental factors; no replication study. This study supports the hypothesis that fetal APOL1 kidney risk alleles are associated with increased risk for preeclampsia in a recessive mode of inheritance in African Americans and suggests that maternal-fetal genotype discordance is also associated with this risk. These conclusions underscore the need to better understand maternal-fetal interaction and their genetic and environmental factors as contributors to ethnic disparities in preeclampsia.

Cholesterol Crystals and NLRP3 Mediated Inflammation in the Uterine Wall Decidua in Normal and Preeclamptic Pregnancies.

Preeclampsia is a hypertensive and inflammatory pregnancy disorder associated with cholesterol accumulation and inflammation at the maternal-fetal interface. Preeclampsia can be complicated with fetal growth restriction (FGR) and shares risk factors and pathophysiological mechanisms with cardiovascular disease. Cholesterol crystal mediated NLRP3 inflammasome activation is central to cardiovascular disease and the pathway has been implicated in placental inflammation in preeclampsia. Direct maternal-fetal interaction occurs both in the uterine wall decidua and at the placental surface and these aligned sites constitute the maternal-fetal interface. This study aimed to investigate cholesterol crystal accumulation and NLRP3 inflammasome expression by maternal and fetal cells in the uterine wall decidua of normal and preeclamptic pregnancies. Pregnant women with normal (n = 43) and preeclamptic pregnancies with (n = 28) and without (n = 19) FGR were included at delivery. Cholesterol crystals were imaged in decidual tissue by both second harmonic generation microscopy and polarization filter reflected light microscopy. Quantitative expression analysis of NLRP3, IL-1β and cell markers was performed by immunohistochemistry and automated image processing. Functional NLRP3 activation was assessed in cultured decidual explants. Cholesterol crystals were identified in decidual tissue, both in the tissue stroma and near uterine vessels. The cholesterol crystals in decidua varied between pregnancies in distribution and cluster size. Decidual expression of the inflammasome components NLRP3 and IL-1β was located to fetal trophoblasts and maternal leukocytes and was strongest in areas of proximity between these cell types. Pathway functionality was confirmed by cholesterol crystal activation of IL-1β in cultured decidual explants. Preeclampsia without FGR was associated with increased trophoblast dependent NLRP3 and IL-1β expression, particularly in the decidual areas of trophoblast and leukocyte proximity. Our findings suggest that decidual accumulation of cholesterol crystals may activate the NLRP3 inflammasome and contribute to decidual inflammation and that this pathway is strengthened in areas with close maternal-fetal interaction in preeclampsia without FGR.

Relation between Mother's Taekyo, Prenatal and Postpartum Depression, and Infant's Temperament and Colic: A Longitudinal Prospective Approach.

This longitudinal cohort correlational study aimed to confirm the relation among taekyo or traditional prenatal practice, prenatal depression, postpartum depression, maternal–fetal interaction, and infant temperament and colic using a prospective design. We recruited 212 women 16–20 weeks pregnant from July 2017 to September 2018; they were followed up until six months postpartum. Data from 97 participants were used in the final analysis. We used the Edinburgh Postnatal Depression Scale, Cranley’s Maternal–Fetal Attachment Scale, and What My Baby Is Like as measurement tools. We observed a significant correlation between prenatal maternal depression in the first to third trimesters and 6–8 weeks and six months postpartum. In addition, infant temperament at six months old showed a significant negative correlation with prenatal and postpartum depression: the higher the prenatal and postpartum depression level, the more difficult the infant’s temperament. Taekyo practice was significantly related to maternal–fetal attachment (r = 0.45−0.68, p < 0.001). Difficult infants showed more colic episodes than any other type of infant (χ2 = 18.18, p < 0.001). Prenatal and postnatal maternal depression affected infants’ temperament and colic episodes. The management of mothers’ mental health before and after pregnancy is important for infants’ and mothers’ health.

Maternal-fetal genetic interactions, imprinting, and risk of placental abruption

Background: Maternal genetic variations, including variations in mitochondrial biogenesis (MB) and oxidative phosphorylation (OP), are associated with placental abruption (PA). However, the role of maternal-fetal genetic interactions (MFGI) and parent-of-origin (imprinting) effects in PA remain unknown. Objective: To investigate MFGI in MB-OP, and imprinting effects in relation to risk of PA. Methods: Among Peruvian mother-infant pairs (503 PA cases and 1052 controls), independent single nucleotide polymorphisms (SNPs), with linkage-disequilibrium coefficient <0.80, were selected to characterize genetic variations in MB-OP (78 SNPs in 24 genes) and imprinted genes (2713 SNPs in 73 genes). For each MB-OP SNP, four multinomial models corresponding to fetal allele effect, maternal allele effect, maternal and fetal allele additive effect, and maternal-fetal allele interaction effect were fit under Hardy-Weinberg equilibrium, random mating, and rare disease assumptions. The Bayesian information criterion (BIC) was used for model selection. For each SNP in imprinted genes, imprinting effect was tested using a likelihood ratio test. Bonferroni corrections were used to determine statistical significance (p-value < 6.4e-4 for MFGI and p-value < 1.8e-5 for imprinting). Results Abruption cases were more likely to experience preeclampsia, have shorter gestational age, and deliver infants with lower birthweight compared with controls. Models with MFGI effects provided improved fit than models with only maternal and fetal genotype main effects for SNP rs12530904 (p-value = 1.2e-04) in calcium/calmodulin-dependent protein kinase [CaM kinase] II beta (CAMK2B), and, SNP rs73136795 (p-value = 1.9e-04) in peroxisome proliferator-activated receptor-gamma (PPARG), both MB genes. We identified 320 SNPs in 45 maternally-imprinted genes (including potassium voltage-gated channel subfamily Q member 1 [KCNQ1], neurotrimin [NTM], and, ATPase phospholipid transporting 10 A [ATP10A]) associated with abruption. Top hits included rs2012323 (p-value = 1.6E-16) and rs12221520 (p-value1.3e-13) in KCNQ1, rs8036892 (p-value = 9.3E-17) and rs188497582 in ATP10A, rs12589854 (p-value = 2.9E-11) and rs80203467 (p-value = 4.6e-11) in maternally expressed 8, small nucleolar RNA host (MEG8), and rs138281088 in solute carrier family 22 member 2 (SLC22A2) (p-value = 6.8e-9). Conclusions We identified novel PA-related maternal-fetal MB gene interactions and imprinting effects that highlight the role of the fetus in PA risk development. Findings can inform mechanistic investigations to understand the pathogenesis of PA.

Pregnant Agencies: Movement and Participation in Maternal-Fetal Interactions.

Pregnancy presents some interesting challenges for the philosophy of embodied cognition. Mother and fetus are generally considered to be passive during pregnancy, both individually and in their relation. In this paper, we use the enactive operational concepts of autonomy, agency, individuation, and participation to examine the relation between mother and fetus in utero. Based on biological, physiological, and phenomenological research, we explore the emergence of agentive capacities in embryo and fetus, as well as how maternal agency changes as pregnancy advances. We show that qualitatively different kinds of agency have their beginnings already in utero, and to what extent fetal and maternal movement modulate affectivity and individuation in pregnancy. We thus propose that mother and fetus are both agents who participate in pregnancy. Pregnancy then emerges as a relational developmental organization that anchors and holds its developing participants. We end the paper with reflections on ethical implications of this proposal, and suggestions for future research.

Thermal imaging of the fetus: An empirical feasibility study.

Digital Infrared Thermal Imaging (DITI) has much potential in the field of maternal-fetal health and wellbeing research. The fact that it is totally non-invasive is particularly important in this context. The purpose of this study was, for the first time, to assess DITI’s ability to record fetal presentation and position, and other pregnancy-related physiological factors, via their superficial thermal prints. Ten healthy pregnant women (approximately 34–37 weeks of gestation) were recorded with two thermal imaging cameras (Flir C3 and i3 TE-Q1) from five different viewpoints. Participants’ views about the use of DITI in research and clinical practice were also assessed by a completion of a survey. Free hand polygon region of interests (ROIs) were drawn in order to include the entire anatomical area for investigation. The use of free hand polygon ROIs showed high reliability. Thermal images analysis revealed that fetuses presenting cephalically can be identified by the use of DITI, under specific conditions. Fetal movements influenced the thermal patterns that were produced. Future studies need to verify the heat patterns on the skin related to the placenta location, in order to understand the produced thermal recordings. Pregnant women rated the idea of using DITI in research and clinical practice very highly. This work represents a first contribution towards the use of DITI for the recording of fetal presentation and position. As it does not require direct contact and since it is completely non-invasive, it could be used to record maternal-fetal dynamic dyadic interaction in pregnancy. However, although the preliminary results are promising, further trans-disciplinary studies with a well-established protocol, more sophisticated thermal cameras, and bigger cohorts are needed.

Crosstalk between estradiol and NFκB signaling pathways on placental leptin expression.

Pregnancy success requires a proper fetal maternal interaction at the establishment of implantation. Leptin has been described as a multitasking cytokine in pregnancy, particularly in the placenta, where it acts as an autocrine hormone. The expression of leptin in normal trophoblastic cells is regulated by different endogenous signals. We have previously reported that 17β-estradiol upregulates placental leptin expression through genomic and non-genomic mechanisms. To improve the knowledge of estrogen receptor mechanisms in regulating leptin gene expression, we examined transcription nuclear factor kappa B (NFκB) effect on estradiol leptin induction in human BeWo cell line and human term placental explants. We demonstrated that estradiol induction effect on leptin expression is blocked by the inhibition of NFκB signaling. We also found that the overexpression of p65 subunit, the active form of NFκB, induces leptin expression. Moreover, downregulation of estrogen receptor alpha (ERα), through a specific siRNA, abolished NFκB effect on leptin expression. We also demonstrated that ERα enhanced NFκB signaling pathway activation in trophoblastic cells. Estradiol treatment significantly increased p65 expression and phosphorylation of the inhibitory protein κB alpha (IκBα). A reporter plasmid containing NFκB elements was also induced in response to estradiol stimulation. Localization experiments revealed that estradiol treatment induced nuclear localization of overexpressed p65. Moreover, the overexpression of ERα produced a complete displacement of p65 protein to the nucleus. Finally, immunoprecipitation experiments showed the presence of a complex containing ERα and NFκB. All these evidences suggest a cooperative behavior between ERα and NFκB transcription factors to induce leptin transcription.

The Primacy of Maternal Innovations to the Evolution of Embryo Implantation.

Embryo implantation is a hallmark of the female reproductive biology of eutherian (placental) mammals and does not exist in a sustainable form in any other vertebrate group. Implantation is the initial process that leads to a sustained fetal-maternal unit engendering a complex functional relationship between the mother and the embryo/fetus. The nature of this relationship is often portrayed as one of conflict between an aggressive embryo and a passive or defensive maternal organism. Recent progress in elucidating the evolutionary origin of eutherian pregnancy leads to a different picture. The emerging scenario suggests that the very initial stages in the evolution of embryo implantation required evolutionary changes to the maternal physiology which modified an ancestral generic mucosal inflammation in response to the presence of the embryo into an active embedding process. This "female-first" evolutionary scenario also explains the role of endometrial receptivity in human pregnancy. On the marsupial side, where in most animals the fetal-maternal interaction is short and does not lead to a long term sustainable placentation, the relationship is mutual. In these mammals, uterine inflammation is followed by parturition in short order. The inflammatory signaling pathways, however, are cooperative, i.e., they are performed by both the fetus and the mother and therefore we call this relationship "cooperative inflammation." Based on these discoveries we reconceive the narrative of the maternal-fetal relationship.

Exploring the Nutritional Ecology of Stunting: New Approaches to an Old Problem.

Despite a declining prevalence, stunting remains an elusive target for the global health community. The perception is that stunting represents chronic undernutrition (i.e., due to inadequate nutrient intake associated with food insecurity, low-quality diet, and suboptimal infant feeding practices in the first two years of life). However, other causes include maternal–fetal interactions leading to intrauterine growth retardation, poor maternal nutrition during pregnancy and lactation, and maternal and pediatric infections. Moreover, physical, economic, demographic, and social environments are major contributors to both food insecurity and conditions that limit linear growth. Overall, factors representing both the internal and external “nutritional ecologies” need to be considered in efforts to reduce stunting rates. Nutritional assessment requires better understanding of the mechanism and role of nutrition in growth, clear expectations about the sensitivity and specificity of the tools used, and inclusion of bio-indicators reflecting the extent and nature of the functional effect of poor nutrition and environmental factors contributing to human physical growth. We provide a perspective on current knowledge about: (i) the biology and contribution of nutrition to stunting/poor growth; (ii) our current nutritional assessment toolkit; (iii) the implications of current assessment approaches for clinical care and public interventions; and (iv) future directions for addressing these challenges in a changing global health environment.

Using Mitochondrial Trifunctional Protein Deficiency to Understand Maternal Health.

Fatty acid oxidation disorders unfortunately can result in the sudden unexplained death of infants. Mitochondrial trifunctional protein (MTP) deficiency is one such disease where long-chain fatty acids cannot be fully oxidized through beta-oxidation which, can lead to cardiac arrythmias in an infant. Furthermore, mothers who are carrying an MTP deficient fetus have a prevalence for pregnancy complications, especially AFLP, acute fatty liver of pregnancy and HELLP syndrome. To better understand the etiology of the potential pro-arrhythmic state the MTP deficient infants may enter, we developed an in vitro model of MTP deficiency in cardiomyocytes to elucidate the underpinning molecular mechanism of this disease. Using CRISPR/Cas9, we developed MTP deficient mutant and knockout pluripotent stem cell lines. Furthermore, we generated patient derived induced pluripotent stem cell lines harboring a so-called founder mutation, the most commonly identified alteration in MTP in the population. Upon differentiating these mutant stem cells into cardiomyocytes and then challenging with fatty acids, we observed pro-arrhythmic behavior, depressed mitochondrial energetics, and elevated hydroxylated long-chain fatty acids, all perhaps expected phenotypes due to MTP deficiency. However, unexpectedly, we also identified an inability of these disease cardiomyocytes to generate mature cardiolipin. Cardiolipin is a key pillar of the powerhouse of life, mitochondria. For the first time this disease-in-a-dish model revealed the key culprit for the dramatic MTP mutant mitochondrial defects and identified potentially a second role for the enzyme HADHA in MTP. HADHA is required for the biosynthesis of functional cardiolipin and therefore healthy mitochondria. However, in the disease, defective cardiolipin results in mitochondrial abnormalities and cardiac arrythmias in infants. These studies reveal an important target for sudden infant death syndrome therapy. With this foundational work on an in vitro model of MTP deficiency and potential avenues for therapy, the next important task is to extend this model to address fetal-maternal interactions towards better governing maternal health.

63 Inhibition of CXCR4 at the fetal-maternal interface during placentation results in altered production of vascular endothelial growth factor receptors in the placenta on Day 90 of pregnancy

Placental development is characterised by extensive angiogenesis and vascularization; if these processes are compromised, placental dysfunction occurs, which is the underlying cause of complications such as preeclampsia and intrauterine growth restriction. The signalling axis initiated by chemokine ligand 12 (CXCL12) and its receptor CXCR4 stimulate angiogenesis critical to placental vascularization. Our laboratory and others demonstrated stimulation of vascular endothelial growth factor (VEGF) synthesis by CXCL12/CXCR4 signalling, and recently, we reported less production of the VEGF receptor, FLT-1, on Day 20 in pregnant sheep following interference of intrauterine CXCL12-dependent signalling. While no animal model fully recapitulates human placentation, the sheep is arguably the most applicable animal model to study fetal-maternal interactions and placentation. Based on our studies, we hypothesised that inhibiting CXCR4 at the fetal-maternal interface during initial placentation alters placental production of VEGF receptors, FLT-1 and KDR, at mid-gestation. To test this hypothesis, AMD3100, a CXCR4 antagonist, was used to elucidate the role of CXCL12/CXCR4 signalling at the ovine fetal-maternal interface. On Day 12 post-breeding, osmotic pumps were surgically installed and delivered either AMD3100 or phosphate-buffered saline (PBS) into the uterine lumen ipsilateral to the corpus luteum for either 7 days (n=7 PBS and n=8 AMD3100) or 14 days (n=7 PBS and n=8 AMD3100). The objectives were to determine whether disruption of the CXCL12/CXCR4 axis during placentation affects fetal survival and alters VEGF receptor synthesis and whether duration of CXCR4 inhibition affects placental vascular remodelling. On Day 90 of pregnancy, ewes were anaesthetised; reproductive tracts were removed; and maternal caruncle (CAR) and fetal cotyledon (COT) components were separated, snap frozen in liquid nitrogen, and stored at −80°C until protein isolation. Pregnancy success was not affected by treatment or duration of treatment (71% PBS vs. 62% AMD3100 for 7 days; 85% PBS vs. 62% AMD3100 for 14 days). In addition, fetal weight on Day 90 (530.8±28.2 g PBS vs. 540.5±20.3g AMD3100 for 7 days; 494.3±23.9g PBS vs. 532.7±11.8g AMD3100 for 14 days) was not affected by treatment. Immunoblotting was used to detect protein abundance, and an unpaired two-tailed Student's t-test was used to determine significant changes. Greater FLT-1 (P&amp;lt;0.05) was evident in CAR and COT tissue on Day 90 for both the 7-day treatment (0.92±0.16 CAR PBS vs. 1.48±0.18 CAR AMD3100; 0.12±0.16 COT PBS vs. 0.62±0.16 COT AMD3100) and the 14-day treatment (0.18±0.05 CAR PBS vs. 0.43±0.001 CAR AMD3100; 0.04±0.005 COT PBS vs. 0.11±0.02 COT AMD3100) of CXCR4 inhibition compared with controls, whereas KDR levels did not change (P&amp;gt;0.05). Interestingly, elevated FLT-1, but not KDR, is a marker of preeclampsia in women, and because of its role as a VEGF scavenger, overexpression of FLT-1 often leads to an anti-angiogenic state. We suggest that CXCL12/CXCR4 signalling during initial placental development serves as an upstream regulator of placental vascularization, thereby ensuring appropriate placental development.

Transcriptome-wide analysis of the SCNT bovine abnormal placenta during mid- to late gestation

The dysfunction of placenta is common in somatic cell nuclear transfer (SCNT) cloned cattle and would cause aberrant fetal development and even abortion, which occurred with highest rate at the mid- to late gestation. However, the mechanism of abnormal placentas was unclear. To analyze the transcriptome-wide characteristics of abnormal placentas in SCNT cloned cattle, the mRNA, lncRNA and miRNA of placental cotyledon tissue at day 180 after gestation were sequenced. A total of 19,055 mRNAs, 30,141 lncRNAs and 684 miRNAs were identified. Compared with control group, 362 mRNAs, 1,272 lncRNAs and nine miRNAs (six known and three novel miRNAs) were differentially expressed (fold change ≥ 2 and P-value < 0.05). The differentially expressed genes were functionally enriched in urea and ions transmembrane transport, which indicated that the maternal-fetal interactions were disturbed in impaired placentas. Furthermore, the competing endogenous RNAs (ceRNAs) networks were identified to illustrate their roles in abnormal placental morphology. The present research would be helpful to discover the mechanism of late gestational abnormality of SCNT cattle by provides important genomic information and insights.