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SET domain-containing 2 (SETD2), the primary methyltransferase for histone 3 lysine-36 trimethylation (H3K36me3) in mammals, is associated with many hematopoietic diseases when mutated. Previous works have emphasized its role in maintaining adult hematopoietic stem cells or tumorigenesis, however, whether and how SETD2 regulates erythropoiesis during embryonic development is relatively unexplored. In this study, using a conditional SETD2 knockout (KO) mouse model, we reveal that SETD2 plays an essential role in fetal erythropoiesis. Loss of Setd2 in hematopoietic cells ablates H3K36me3, and leads to anemia with a significant decrease in erythroid cells in the peripheral blood at E18.5. This is due to impaired erythroblast differentiation in both spleen and liver. We also find increased proportions of nucleated erythrocytes in the blood of Setd2 KO embryos. Lastly, we ascribe embryonic erythropoiesis-related genes Vegfc, Vegfr3, and Prox1, as likely downstream targets of SETD2 regulation. Our study reveals a critical role of SETD2 in fetal erythropoiesis that precedes adult hematopoiesis, and provide unique insights into the defects in erythroid lineages, such as anemia., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Although studies have focused on extracellular matrix (ECM) remodeling during the formation and functioning of adult ovaries, there is no comprehensive understanding of the mechanisms controlling preantral follicle development in fetal bovine ovaries during gestation. Thus, to gain insights into ECM remodeling during initial ovarian development, we used fetal ovaries to quantify the fractal dimension (FD), total collagen, and relative mRNA abundance of genes related to ECM remodeling (COL1A1, COL1A2, COL4A1, MMP2, MMP9, MMP14, TIMP1, and TIMP2). For this, pairs of fetal ovaries were obtained from cows in a local abattoir at days 60, 90, 120, and 150 of gestation; one of each pair was submitted to RNA extraction for target transcript analysis, and the other was used for total collagen and FD evaluation. From day 120 total collagen appeared to occupy a greater area in the fetal ovary. The fractal analysis with picrosirius red staining shows higher at day 150 when compared with that on day 60. On the contrary, we found an inverse pattern when we used the hematoxylin and eosin staining approach. Concerning target gene expression, the relative abundances of COL1A1, COL4A1, MMP2, MMP14, TIMP1, and TIMP2 mRNA were higher on day 150 when compared with that on day 60. We conclude that fractal analysis reflects the morphological changes occurring during structural organization of the fetal ovary and that the expression of genes related to ECM remodeling is modulated throughout gestation in bovine fetal ovaries., Competing Interests: Declaration of competing interest We declare that there is no conflict of interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Non-invasive prenatal testing (NIPT) is performed worldwide to detect common chromosomal aneuploidies. The analysis of cell-free DNA (cfDNA) in maternal blood for NIPT is highly accurate for the detection of the main fetal trisomies: 21,18, and 13. However, false-positive, false-negative, and non-reportable results can occur, and these can have biological causes. Understanding the causes of unexpected NIPT results is essential to enable clinicians and genetic counselors to counsel patients comprehensively and appropriately, both prior to testing as well as after receiving the test results. The classification of non-reportable results from cfDNA analysis is important in order to provide women with precise information. In addition to technical issues, there are biological reasons for discordant results, which can be either fetal or maternal in origin. Contributing fetal factors include insufficient or absent fetal fraction, fetoplacental mosaicism, and the presence of a vanishing twin. In some pregnant women that test positive for NIPT, multiple chromosome aneuploidy has been reported as a result of suspected malignancy, and cancer has been found. False-positive and false-negative results may be the result of placental biology and not a failure in the actual test platform. Explaining the placental origin of cfDNA provides the patient with a clear view of the abilities and limitations of cfDNA-based prenatal screening., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to disclose., (Copyright © 2020. Published by Elsevier B.V.)

Human lymphopoiesis is a dynamic lifelong process that starts in utero 6 weeks postconception. Although fetal B-lymphopoiesis remains poorly defined, it is key to understanding leukemia initiation in early life. Here, we provide a comprehensive analysis of the human fetal B-cell developmental hierarchy. We report the presence in fetal tissues of 2 distinct CD19 + B-progenitors, an adult-type CD10+ve ProB-progenitor and a new CD10-ve PreProB-progenitor, and describe their molecular and functional characteristics. PreProB-progenitors and ProB-progenitors appear early in the first trimester in embryonic liver, followed by a sustained second wave of B-progenitor development in fetal bone marrow (BM), where together they form >40% of the total hematopoietic stem cell/progenitor pool. Almost one-third of fetal B-progenitors are CD10-ve PreProB-progenitors, whereas, by contrast, PreProB-progenitors are almost undetectable (0.53% ± 0.24%) in adult BM. Single-cell transcriptomics and functional assays place fetal PreProB-progenitors upstream of ProB-progenitors, identifying them as the first B-lymphoid-restricted progenitor in human fetal life. Although fetal BM PreProB-progenitors and ProB-progenitors both give rise solely to B-lineage cells, they are transcriptionally distinct. As with their fetal counterparts, adult BM PreProB-progenitors give rise only to B-lineage cells in vitro and express the expected B-lineage gene expression program. However, fetal PreProB-progenitors display a distinct, ontogeny-related gene expression pattern that is not seen in adult PreProB-progenitors, and they share transcriptomic signatures with CD10-ve B-progenitor infant acute lymphoblastic leukemia blast cells. These data identify PreProB-progenitors as the earliest B-lymphoid-restricted progenitor in human fetal life and suggest that this fetal-restricted committed B-progenitor might provide a permissive cellular context for prenatal B-progenitor leukemia initiation., (© 2019 by The American Society of Hematology.)

Objective: The epithelium lining the human middle ear and adjacent temporal bone cavity shows a varying morphological appearance throughout these cavities. Its embryologic origin has long been debated and recently got attention in a newly proposed theory of a dual embryologic origin. The epithelial morphology and its differentiating capabilities are of significance in future mucosa-targeted therapeutic agents and could affect surgical approaches of the temporal bone. This study aims to analyze reported murine histological findings that led to the theory of a dual epithelial embryological origin and immunohistochemically investigate whether such an epithelial embryological origin in the human fetal middle ear could be true., Methods: By combining a sagittal sectioning technique and immuno-histochemical staining, a comprehensive immuno-histological overview of the fetal human middle ear during a critical stage of tympanic cavitation was provided. A critical analysis of previously reported findings leading to the theory of a dual epithelial embryological origin and a comparison of these findings to the findings in the human fetal middle ear was performed., Results: The reported findings and critical analysis provide multiple arguments for an entirely endodermal embryonic origin of the epithelium lining the tympanic cavity., Conclusion: Different morphological epithelial appearances throughout the tympanic and temporal bone cavities could be explained by different stages of epithelial differentiation rather than different embryologic origin and endodermal rupture does not seem to be a necessity for these cavities to form., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Cyclin-dependent kinase 5 (Cdk5) controls neuronal migration in the developing cortex when multipolar newborn neurons transform to become bipolar. However, by which mechanisms Cdk5 controls cell adhesion in migrating neurons are not fully understood. In this study, we examined the functional interaction between Cdk5 and N-cadherin (Ncad) in newborn neurons when they undergo the multipolar to bipolar transition in the intermediate zone (IZ). Detailed expression analysis revealed that both Cdk5 and Ncad were present in GFP-electroporated migrating neurons in the IZ. Misexpression of dominant negative Cdk5 into the embryonic brains stalled neuronal locomotion in the lower IZ in which arrested cells were round or multipolar. When Ncad was co-introduced with Cdk5DN, however, cells continue to migrate into the cortical plate (CP) and migrating neurons acquired typical bipolar morphology with a pia-directed leading process. Similarly, downregulation of CDK5 resulted in lesser aggregation ability, reversed by the expression of Ncad in vitro. Down-regulation of activity or protein level of CDK5 did not alter the total amount of NCAD proteins but lowered its surface expression in cells. Lastly, expression of CDK5 and NCAD overlapped in the IZ of the human fetal cortex, indicating that the role of Cdk5 and Ncad in neuronal migration is evolutionarily conserved., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Maternal nutrition has become a major public health concern over recent years and is a known predictor of adverse long-term metabolic derangement in offspring. Time-restricted feeding (TRF), wherein food consumption is restricted to the metabolically active phase of the day, is a dietary approach that improves metabolic parameters when consuming a high-fat diet (HFD). Here, we tested whether TRF could reduce maternal HFD associated inflammation and thereby mitigate defects in fetal organ developmental. Female rats were kept on following three dietary regimens; Ad libitum normal chow diet (NCD-AL), Ad libitum HFD (HFD-AL) and Time-restricted fed HFD (HFD-TRF) from 5 months prior to mating and continued throughout pregnancy. Rat dams were sacrificed at embryonic day 18.5 (ED18.5) and placental tissues from these rats were processed for the analysis of cellular apoptosis, inflammatory cytokines (TNFα and IL-6), oxidative stress, endoplasmic reticulum (ER) stress and autophagy. Furthermore, fetal hepatic triglyceride (TG) content and fetal lung maturation were assessed at ED18.5. Biochemical analysis revealed that HFD-TRF rat had significantly lower serum TG levels and body weight compared to HFD-AL rats. Additionally, TRF significantly blocked HFD-induced placental apoptosis and inflammation via minimizing cellular stress, and restoring autophagic flux. In addition, fetal hepatosteatosis and delayed fetal lung maturation induced by HFD was significantly ameliorated in HFD-TRF compared to HFD-AL. Collectively, our results suggest that reducing placental inflammation via TRF could prevent adverse fetal metabolic outcomes in pregnancies complicated by maternal obesity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The antenatal evaluation of the fetal central nervous system (CNS) is among the most difficult tasks of prenatal ultrasound (US), requiring technical skills in relation to ultrasound and image acquisition as well as knowledge of CNS anatomy and how this changes with gestation. According to the International Guidelines for fetal neurosonology, the basic assessment of fetal CNS is most frequently performed on the axial planes, whereas the coronal and sagittal planes are required for the multiplanar evaluation of the CNS within the context of fetal neurosonology. It can be even more technically challenging to obtain "nonaxial" views with 2-dimensional (2D) US. The modality of 3-dimensional (3D) US has been suggested as a panacea to overcome the technical difficulties of achieving nonaxial views. The lack of familiarity of most sonologists with the use of 3D US and its related processing techniques may preclude its use even where it could play an important role in complementing antenatal 2D US assessment. Furthermore, once a 3D volume has been acquired, proprietary software allows it to be processed in different ways, leading to multiple ways of displaying and analyzing the same anatomical imaging or plane. These are difficult to learn and time consuming in the absence of specific training. In this article, we describe the key steps for volume acquisition of a 3D US volume, manipulation, and processing with reference to images of the fetal CNS, using a newly developed context-preserving rendering technique., (Copyright © 2018. Published by Elsevier Inc.)

Human induced pluripotent stem cell line was generated from commercially available primary human prostate fibroblasts HPrF derived from a fetus, aged 18-24 weeks of gestation. The fibroblast cell line was reprogrammed with Yamanaka factors (OCT4, SOX2, c-MYC, KLF4) using CytoTune™-iPS 2.0 Sendai Reprogramming Kit. Pluripotency of the derived transgene-free iPS cell line was confirmed both in vitro by detecting the expression of factors of pluripotency on a single-cell level, and in vivo using teratoma formation assay. This iPS cell line will be a useful tool for studying both normal prostate development and prostate cancer disease., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Adverse prenatal environmental influences to the developing fetus are associated with mental and cardiovascular disease in later life. Universal developmental characteristics such as self-organization, pattern formation, and adaptation in the growing information processing system have not yet been sufficiently analyzed with respect to description of normal fetal development and identification of developmental disturbances. Fetal heart rate patterns are the only non-invasive order parameter of the developing autonomic brain available with respect to the developing complex organ system. The objective of the present study was to investigate whether universal indices, known from evolution and phylogeny, describe the ontogenetic fetal development from 20 weeks of gestation onwards. By means of a 10-fold cross-validated data-driven multivariate regression modeling procedure, relevant indices of heart rate variability (HRV) were explored using 552 fetal heart rate recordings, each lasting over 30 min. We found that models which included HRV indices of increasing fluctuation amplitude, complexity and fractal long-range dependencies largely estimated the maturation age (coefficients of determination 0.61-0.66). Consideration of these characteristics in prenatal care may not only have implications for early identification of developmental disturbances, but also for the development of system-theory-based therapeutic strategies., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Extracellular matrices (ECMs) are structurally and compositionally diverse networks of collagenous and noncollagenous glycoproteins, glycosaminoglycans, proteoglycans, and associated molecules that together comprise the metazoan matrisome. Proper deposition and assembly of ECM is of profound importance to cell proliferation, survival, and differentiation, and the morphogenesis of tissues and organ systems that define sequential steps in the development of all animals. Importantly, it is now clear that the instructive influence of a particular ECM at various points in development reflects more than a simple summing of component parts; cellular responses also reflect the dynamic assembly and changing topology of embryonic ECM, which in turn affect its biomechanical properties. This review highlights recent advances in understanding how biophysical features attributed to ECM, such as stiffness and viscoelasticity, play important roles in the sculpting of embryonic tissues and the regulation of cell fates. Forces generated within cells and tissues are transmitted both through integrin-based adhesions to ECM, and through cadherin-dependent cell-cell adhesions; the resulting short- and long-range deformations of embryonic tissues drive morphogenesis. This coordinate regulation of cell-ECM and cell-cell adhesive machinery has emerged as a common theme in a variety of developmental processes. In this review we consider select examples in the embryo where ECM is implicated in setting up tissue barriers and boundaries, in resisting pushing or pulling forces, or in constraining or promoting cell and tissue movement. We reflect on how each of these processes contribute to morphogenesis., (Copyright © 2018 Elsevier Inc. All rights reserved.)

How the fetal-placental arterial connection is made and positioned relative to the embryonic body axis, thereby ensuring efficient and directed blood flow to and from the mother during gestation, is not known. Here we use a combination of genetics, timed pharmacological inhibition in living mouse embryos, and three-dimensional modeling to link two novel architectural features that, at present, have no status in embryological atlases. The allantoic core domain (ACD) is the extraembryonic extension of the primitive streak into the allantois, or pre-umbilical tissue; the vessel of confluence (VOC), situated adjacent to the ACD, is an extraembryonic vessel that marks the site of fetal-placental arterial union. We show that genesis of the fetal-placental connection involves the ACD and VOC in a series of steps, each one dependent upon the last. In the first, Brachyury (T) ensures adequate extension of the primitive streak into the allantois, which in turn designates the allantoic-yolk sac junction. Next, the streak-derived ACD organizes allantoic angioblasts to the axial junction; upon signaling from Fibroblast Growth Factor Receptor-1 (FGFR1), these endothelialize and branch, forming a sprouting VOC that unites the umbilical and omphalomesenteric arteries with the fetal dorsal aortae. Arterial union is followed by the appearance of the medial umbilical roots within the VOC, which in turn designate the correct axial placement of the lateral umbilical roots/common iliac arteries. In addition, we show that the ACD and VOC are conserved across Placentalia, including humans, underscoring their fundamental importance in mammalian biology. We conclude that T is required for correct axial positioning of the VOC via the primitive streak/ACD, while FGFR1, through its role in endothelialization and branching, further patterns it. Together, these genetic, molecular and structural elements safeguard the fetus against adverse outcomes that can result from vascular mispatterning of the fetal-placental arterial connection., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The allantois-derived umbilical component of the chorio-allantoic placenta shuttles fetal blood to and from the chorion, thereby ensuring fetal-maternal exchange. The progenitor populations that establish and supply the fetal-umbilical interface lie, in part, within the base of the allantois, where the germ line is claimed to segregate from the soma. Results of recent studies in the mouse have reported that STELLA (DPPA-3, PGC7) co-localizes with PRDM1 (BLIMP1), the bimolecular signature of putative primordial germ cells (PGCs) throughout the fetal-placental interface. Thus, if PGCs form extragonadally within the posterior region of the mammal, they cannot be distinguished from the soma on the basis of these proteins. We used immunohistochemistry, immunofluorescence, and confocal microscopy of the mouse gastrula to co-localize STELLA with a variety of gene products, including pluripotency factor OCT-3/4, mesendoderm-associated T and MIXl1, mesendoderm- and endoderm-associated FOXa2 and hematopoietic factor Runx1. While a subpopulation of cells localizing OCT-3/4 was always found independently of STELLA, STELLA always co-localized with OCT-3/4. Despite previous reports that T is involved in specification of the germ line, co-localization of STELLA and T was detected only in a small subset of cells in the base of the allantois. Slightly later in the hindgut lip, STELLA+/(OCT-3/4+) co-localized with FOXa2, as well as with RUNX1, indicative of definitive endoderm and hemangioblasts, respectively. STELLA was never found with MIXl1. On the basis of these and previous results, we conclude that STELLA identifies at least five distinct cell subpopulations within the allantois and hindgut, where they may be involved in mesendodermal differentiation and hematopoiesis at the posterior embryonic-extraembryonic interface. These data provide a new point of departure for understanding STELLA's potential roles in building the fetal-placental connection., (Copyright © 2017 Elsevier Inc. All rights reserved.)

This study detected the impact of maternal carbamazepine (CBZ) on the fetal neuroendocrine-cytokines axis. 25 or 50mg/kg of CBZ was intraperitoneally administrated to pregnant albino rats from the gestation day (GD) 1 to 20. Both administrations of CBZ caused a hypothyroidism in dams and fetuses whereas the decreases in serum thyroxine (T4) and triiodothyronine (T3) and increases in serum thyrotropin (TSH) levels were highly significant (LSD; P <0.01) at GD 20 compared to untreated control dams. Also, both administrations had undesirable impacts on the maternofetal body weight, litter weight, survival of dams and fetuses, and their food consumption in comparison to the corresponding control. These administrations also elicited a reduction in fetal serum growth hormone (GH), interferon-γ (IFNγ), interleukins (IL-2 & 4) and prostaglandin E2 (PGE2) levels. Also, the elevation in fetal serum tumor necrosis factor-alpha (TNFα), transforming growth factor-beta (TGFβ), and interleukins (IL-1β & 17) levels was observed at embryonic day (ED) 20. Moreover, there were a cellular fragmentation, distortion, hyperemia, oedema and vacuolation in the fetal cerebellar cortex due to both maternal administrations. These developmental changes were dose-dependent. These novel results suggest that CBZ may act as a developmental immunoneuroendocrine disruptor., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Retinoic acid (RA) is a potent inducer of cell differentiation and plays an essential role in sex-specific germ cell development in the mammalian gonad. RA is essential for male gametogenesis and hence fertility. However, RA can also disrupt sexual cell fate in somatic cells of the testis, promoting transdifferentiation of male Sertoli cells to female granulosa-like cells when the male sexual regulator Dmrt1 is absent. The feminizing ability of RA in the Dmrt1 mutant somatic testis suggests that RA might normally play a role in somatic cell differentiation or cell fate maintenance in the ovary. To test for this possibility we disrupted RA signaling in somatic cells of the early fetal ovary using three genetic strategies and one pharmaceutical approach. We found that deleting all three RA receptors (RARs) in the XX somatic gonad at the time of sex determination did not significantly affect ovarian differentiation, follicle development, or female fertility. Transcriptome analysis of adult triple mutant ovaries revealed remarkably little effect on gene expression in the absence of somatic RAR function. Likewise, deletion of three RA synthesis enzymes (Aldh1a1-3) at the time of sex determination did not masculinize the ovary. A dominant-negative RAR transgene altered granulosa cell proliferation, likely due to interference with a non-RA signaling pathway, but did not prevent granulosa cell specification and oogenesis or abolish fertility. Finally, culture of fetal XX gonads with an RAR antagonist blocked germ cell meiotic initiation but did not disrupt sex-biased gene expression. We conclude that RA signaling, although crucial in the ovary for meiotic initiation, is not required for granulosa cell specification, differentiation, or reproductive function., (Copyright © 2017 Elsevier Inc. All rights reserved.)

In vitro human pluripotent stem cell (hPSC) derived tissues are excellent models to study certain aspects of normal human development. Current research in the field of hPSC derived tissues reveals these models to be inherently fetal-like on both a morphological and gene expression level. In this review we briefly discuss current methods for differentiating lung and intestinal tissue from hPSCs into individual 3-dimensional units called organoids. We discuss how these methods mirror what is known about in vivo signaling pathways of the developing embryo. Additionally, we will review how the inherent immaturity of these models lends them to be particularly valuable in the study of immature human tissues in the clinical setting of premature birth. Human lung organoids (HLOs) and human intestinal organoids (HIOs) not only model normal development, but can also be utilized to study several important diseases of prematurity such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and necrotizing enterocolitis (NEC)., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to other tissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functional maturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health.

Mutations that impair the proliferation of enteric neural crest-derived cells (ENCDC) cause Hirschsprung disease, a potentially lethal birth defect where the enteric nervous system (ENS) is absent from distal bowel. Inosine 5' monophosphate dehydrogenase (IMPDH) activity is essential for de novo GMP synthesis, and chemical inhibition of IMPDH induces Hirschsprung disease-like pathology in mouse models by reducing ENCDC proliferation. Two IMPDH isoforms are ubiquitously expressed in the embryo, but only IMPDH2 is required for life. To further understand the role of IMPDH2 in ENS and neural crest development, we characterized a conditional Impdh2 mutant mouse. Deletion of Impdh2 in the early neural crest using the Wnt1-Cre transgene produced defects in multiple neural crest derivatives including highly penetrant intestinal aganglionosis, agenesis of the craniofacial skeleton, and cardiac outflow tract and great vessel malformations. Analysis using a Rosa26 reporter mouse suggested that some or all of the remaining ENS in Impdh2 conditional-knockout animals was derived from cells that escaped Wnt1-Cre mediated DNA recombination. These data suggest that IMPDH2 mediated guanine nucleotide synthesis is essential for normal development of the ENS and other neural crest derivatives., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The fetal liver (FL) serves as a predominant site for expansion of functional hematopoietic stem cells (HSCs) during mouse embryogenesis. However, the mechanisms for HSC development in FL remain poorly understood. In this study, we demonstrate that deletion of activating transcription factor 4 (ATF4) significantly impaired hematopoietic development and reduced HSC self-renewal in FL. In contrast, generation of the first HSC population in the aorta-gonad-mesonephros region was not affected. The migration activity of ATF4(-/-) HSCs was moderately reduced. Interestingly, the HSC-supporting ability of both endothelial and stromal cells in FL was significantly compromised in the absence of ATF4. Gene profiling using RNA-seq revealed downregulated expression of a panel of cytokines in ATF4(-/-) stromal cells, including angiopoietin-like protein 3 (Angptl3) and vascular endothelial growth factor A (VEGFA). Addition of Angptl3, but not VEGFA, partially rescued the repopulating defect of ATF4(-/-) HSCs in the culture. Furthermore, chromatin immunoprecipitation assay in conjunction with silencing RNA-mediated silencing and complementary DNA overexpression showed transcriptional control of Angptl3 by ATF4. To summarize, ATF4 plays a pivotal role in functional expansion and repopulating efficiency of HSCs in developing FL, and it acts through upregulating transcription of cytokines such as Angptl3 in the microenvironment., (© 2015 by The American Society of Hematology.)

Acetaminophen (APAP; ie, Paracetamol or Tylenol) is generally self-medicated to treat fever or pain and recommended to pregnant women by their physicians. Recent epidemiological studies reveal an association between prenatal APAP use and an increased risk for asthma. Our aim was to identify the effects of APAP in pregnancy using a mouse model. Allogeneically mated C57Bl/6J females were injected i.p. with 50 or 250 mg/kg APAP or phosphate-buffered saline on gestation day 12.5; nonpregnant females served as controls. Tissue samples were obtained 1 or 4 days after injection. APAP-induced liver toxicity was mirrored by significantly increased plasma alanine aminotransferase levels. In uterus-draining lymph nodes of pregnant dams, the frequencies of mature dendritic cells and regulatory T cells significantly increased on 250 mg/kg APAP. Plasma progesterone levels significantly decreased in dams injected with APAP, accompanied by a morphologically altered placenta. Although overall litter sizes and number of fetal loss remained unaltered, a reduced fetal weight and a lower frequency of hematopoietic stem cells in the fetal liver were observed on APAP treatment. Our data provide strong evidence that prenatal APAP interferes with maternal immune and endocrine adaptation to pregnancy, affects placental function, and impairs fetal maturation and immune development. The latter may have long-lasting consequences on children's immunity and account for the increased risk for asthma observed in humans., (Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Blood and lymphatic vessels provide nutrients for the skin and fulfill important homeostatic functions, such as the regulation of immunologic processes. In this study, we investigated the development of blood and lymphatic endothelial cells in prenatal human skin in situ using multicolor immunofluorescence and analyzed angiogenic molecules by protein arrays of lysates and cell culture supernatants. We found that at 8 to 10 weeks of estimated gestational age, CD144(+) vessels predominantly express the venous endothelial cell marker PAL-E, whereas CD144(+)PAL-E(-) vessels compatible with arteries only appear at the end of the first trimester. Lymphatic progenitor cells at 8 weeks of estimated gestational age express CD31, CD144, Prox1, and temporary PAL-E. At that developmental stage not all lymphatic progenitor cells express podoplanin or Lyve-1, which are acquired with advancing gestational age in a stepwise fashion. Already in second-trimester human skin, the phenotype of blood and lymphatic vessels roughly resembles the one in adult skin. The expression pattern of angiogenic molecules in lysates and cell culture supernatants of prenatal skin did not reveal the expected bent to proangiogenic molecules, indicating a complex regulation of angiogenesis during ontogeny. In summary, this study provides enticing new insights into the development and phenotypic characteristics of the vascular system in human prenatal skin., (Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Background: Noninvasive prenatal testing (NIPT) by massively parallel sequencing (MPS) of the circulating cell free fetal (cff) DNA during the second trimester of pregnancy is now a frontline test for detecting common fetal chromosomal abnormalities. However, the availability of an earlier test result in the first trimester would enable better clinical management of high-risk pregnancies. The aim of the study was to determine the feasibility of early gestational NIPT., Methods: Plasma DNA libraries were subjected to MPS and chromosomal read counts normalized to reference. Chromosomal aneuploidy was determined by z-scores (-3

There is an increasing public concern regarding potential health impacts from electromagnetic radiation exposure. Embryonic development is sensitive to the external environment, and limb development is vital for life quality. To determine the effects of electromagnetic pulse (EMP) on polydactyly of mouse fetuses, pregnant mice were sham-exposed or exposed to EMP (400 kV/m with 400 pulses) from Days 7 to 10 of pregnancy (Day 0 = day of detection of vaginal plug). As a positive control, mice were treated with 5-bromodeoxyuridine on Days 9 and 10. On Days 11 or 18, the fetuses were isolated. Compared with the sham-exposed group, the group exposed to EMP had increased rates of polydactyly fetuses (5.1% vs. 0.6%, P < 0.05) and abnormal gene expression (22.2% vs. 2.8%, P < 0.05). Ectopic expression of Fgf4 was detected in the apical ectodermal ridge, whereas overexpression and ectopic expression of Shh were detected in the zone of polarizing activity of limbs in the EMP-exposed group and in the positive control group. However, expression of Gli3 decreased in mesenchyme cells in those two groups. The percentages of programmed cell death of limbs in EMP-exposed and positive control group were decreased (3.57% and 2.94%, respectively, P < 0.05, compared with 7.76% in sham-exposed group). In conclusion, polydactyly induced by EMP was accompanied by abnormal expression of the above-mentioned genes and decreased percentage of programmed cell death during limb development., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model., Methods: Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day., Results: The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5., Conclusion: Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion.

Thirty-one pregnant agoutis, between Days 9 and 103 of gestation (Day 1 = day of detection of sperm in the vaginal smear), underwent B-mode ultrasonography; gestational sac diameter (GSD), crown-rump length (CRL), embryonic-fetal diameter (EFD), and placenta diameter (PD) were measured. There were positive correlations (P < 0.05) between GSD and CRL (r = 0.98), GSD and PD (r = 0.88), CRL and PD (r = 0.86), days of gestation (DG) and CRL (r = 0.85), and DG and PD (r = 0.73). The gestational sac was first observed on Day 14. The embryo was first seen on Day 18 in 9/31 of pregnant agoutis and on Day 22 in 20/31 of pregnant agoutis. Heartbeats were detected from the Day 25 and placentas were observed in 100% of the animals from Day 25. Early limb bud and ossification of the fetal skull were identified on Days 27 (15/31) and 45 (24/31), respectively. Fetal orientation (head and body) was evident from Day 40, the stomach, liver and lungs were identified on Day 50, the kidneys were reliably seen only on Day 55, and the aorta and vena cava were seen on Day 70. The fetal bowel and the urinary bladder were the last structures to be observed (Day 85). Ultrasonography was effective for early pregnancy diagnosis in agouti and for obtaining information on embryonic and fetal structures that could be used to predict gestational age and birth, thereby contributing to their reproductive management in captivity., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Aim: To investigate the effect of increased intra-abdominal pressure (IAP) on the fetal urinary system., Materials and Methods: Pregnant rabbits (15-day gestation) were used. Control (n = 5) and experimental (EG, n = 4) groups underwent intraperitoneal catheter placement. The IAP was increased by intraperitoneal air insufflations during the third trimester in the EG. At term, organ weight and organ weight/body weight (BW) ratios were noted, histological examination of the urinary system organs was performed, and the apoptotic indexes were calculated., Results: BW and total renal weight were significantly increased in the EG (38.65 ± 8.34 g vs 49.36 ± 8.81 g, p = 0.008; and 0.406 ± 0.132 g vs 0.531 ± 0.129 g, p = 0.02). Total renal weight/BW ratio did not differ between groups (0.0103 ± 0.001 vs 0.0107 ± 0.001; p = 0.33). Bladder weight and bladder weight/BW ratio was also significantly increased in the EG (0.067 ± 0.014 g vs 0.114 ± 0.026 g, p = 0.00; and 0.00175 ± 0.00026 vs 0.00229 ± 0.00036, p = 0.001). Immature glomeruli and collecting tubules, and a thin and underdeveloped muscular layer in the ureter and bladder were encountered in the EG, and the apoptotic cell index was significantly increased (p < 0.05)., Conclusion: Increased IAP has an adverse effect on fetal urinary system development, and may play a role in the pathogenesis of various congenital abnormalities of the urinary system., (Copyright © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Heme-regulated eIF2α kinase (Hri) is necessary for balanced synthesis of heme and globin. In addition, Hri deficiency exacerbates the phenotypic severity of β-thalassemia intermedia in mice. Activation of Hri during heme deficiency and in β-thalassemia increases eIF2α phosphorylation and inhibits globin translation. Under endoplasmic reticulum stress and nutrient starvation, eIF2α phosphorylation also induces the Atf4 signaling pathway to mitigate stress. Although the function of Hri in regulating globin translation is well established, its role in Atf4 signaling in erythroid precursors is not known. Here, we report the role of the Hri-activated Atf4 signaling pathway in reducing oxidative stress and in promoting erythroid differentiation during erythropoiesis. On acute oxidative stress, Hri(-/-) erythroblasts suffered from increased levels of reactive oxygen species (ROS) and apoptosis. During chronic iron deficiency in vivo, Hri is necessary both to reduce oxidative stress and to promote erythroid differentiation. Hri(-/-) mice developed ineffective erythropoiesis during iron deficiency with inhibition of differentiation at the basophilic erythroblast stage. This inhibition is recapitulated during ex vivo differentiation of Hri(-/-) fetal liver erythroid progenitors. Importantly, the Hri-eIF2αP-Atf4 pathway was activated and required for erythroid differentiation. We further demonstrate the potential of modulating Hri-eIF2αP-Atf4 signaling with chemical compounds as pharmaceutical therapies for β-thalassemia.

Maternal immune activation (MIA) is a risk factor for the development of schizophrenia and autism. Infections during pregnancy activate the mother's immune system and alter the fetal environment, with consequential effects on CNS function and behavior in the offspring, but the cellular and molecular links between infection-induced altered fetal development and risk for neuropsychiatric disorders are unknown. We investigated the immunological, molecular, and behavioral effects of MIA in the offspring of pregnant Sprague-Dawley rats given an intraperitoneal (0.25 mg/kg) injection of lipopolysaccharide (LPS) on gestational day 15. LPS significantly elevated pro-inflammatory cytokine levels in maternal serum, amniotic fluid, and fetal brain at 4 h, and levels decreased but remained elevated at 24 h. Offspring born to LPS-treated dams exhibited reduced social preference and exploration behaviors as juveniles and young adults. Whole genome microarray analysis of the fetal brain at 4 h post maternal LPS was performed to elucidate the possible molecular mechanisms by which MIA affects the fetal brain. We observed dysregulation of 3285 genes in restricted functional categories, with increased mRNA expression of cellular stress and cell death genes and reduced expression of developmentally-regulated and brain-specific genes, specifically those that regulate neuronal migration of GABAergic interneurons, including the Distal-less (Dlx) family of transcription factors required for tangential migration from progenitor pools within the ganglionic eminences into the cerebral cortex. Our results provide a novel mechanism by which MIA induces the widespread down-regulation of critical neurodevelopmental genes, including those previously associated with autism., (Published by Elsevier Inc.)

Objectives: We used magnetic resonance imaging (MRI) to perform volumetry of foetuses with and without growth restriction, and identify deviations in organ growth., Study Design: 20 growth restricted and 19 normal foetuses were scanned once during pregnancy at gestational age 20.53-36.57 weeks. MRI scans were performed on a 1.5T system using ssFSE sequences. Manual segmentation of whole body, brain, heart, lung, liver, thymus and kidney volume was performed. Data on the severity of foetal growth restriction and pregnancy outcome was collected., Results: There was a significant reduction in foetal whole body volume and volume of all internal organs except the brain in growth restricted foetuses. A brain:liver ratio above 3.0 was associated with a 3.3 fold increase in risk of perinatal mortality (95% CI=1.68-6.47)., Conclusion: MRI provides an accurate assessment of foetal organ growth. It may have a role to play in monitoring disease severity and the effect of future interventions., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

There is a two-way traffic of cells through the placenta during the pregnancy (feta and maternal microchimerisms). Fetal cells migrate in the maternal body where they are present long after birth. The fetal microchimerism may be deleterious for the mother when implicated in the induction of autoimmune diseases and of repeated abortion. Usually fetal microchimerism is beneficial for the mothers. Fetal cells can repair damaged tissues, transmit paternal resistance alleles, improve the directory of T cell receptors. In cancer, the effects are more contrasted, beneficial and protective for certain cancers, harmful and favouring the development for the others. The phenomenon of fetal and maternal microchimerisms inspires numerous questions and offers new perspectives on the biology of pregnancy and cancer, on pathogenesis of auto-immunity, of the transplantations, without forgetting the biology of the heredity because these cells could bring resistance or risk alleles for some diseases from the father towards the mother through the fetus, through the mother to the fetus, from the first fetus of a first pregnancy to the next fetus through the woman., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Peroxisome proliferator-activated receptors (PPARα, PPARδ and PPARγ) are ligand-activated transcription factors that regulate metabolic, anti-inflammatory and developmental processes. The maternal and fetal metabolic impairments, the intrauterine pro-inflammatory environment and the developmental defects induced by maternal diabetes make PPARs an interesting focus of investigation. Therefore, research has been conducted in experimental models of diabetes throughout gestation. During embryo organogenesis, impaired PPARδ signaling pathways are related to the induction of congenital malformations. In fetuses from diabetic rats, both lipid metabolism and several pro-inflammatory markers are regulated by the activation of PPAR isotypes. In the placenta from diabetic animals, activation of different PPAR isotypes regulates lipid metabolism and anti-inflammatory pathways, whereas in term placentas from diabetic patients PPARγ reduces the production of nitric oxide. Decreased PPARγ and PPARα protein expression are found in term placentas of diabetic animals and diabetic patients. In addition, a deficiency in polyunsaturated fatty acids (PUFAs) and impaired formation of arachidonic acid derivatives that activate PPARs is found in several diabetic intrauterine tissues. PPARs can be activated by both natural and pharmacological activators. Intrauterine activation of PPARs can be achieved by the administration of maternal diets enriched in PUFAs. This review summarizes recent advances highlighting the possible beneficial role of PPAR activation on embryonic and feto-placental development in maternal diabetes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The fibroblast growth factor, FGF8, has been shown to be essential for vertebrate cardiovascular, craniofacial, brain and limb development. Here we report that Fgf8 function is required for normal progression through the late fetal stages of lung development that culminate in alveolar formation. Budding, lobation and branching morphogenesis are unaffected in early stage Fgf8 hypomorphic and conditional mutant lungs. Excess proliferation during fetal development disrupts distal airspace formation, mesenchymal and vascular remodeling, and Type I epithelial cell differentiation resulting in postnatal respiratory failure and death. Our findings reveal a previously unknown, critical role for Fgf8 function in fetal lung development and suggest that this factor may also contribute to postnatal alveologenesis. Given the high number of premature infants with alveolar dysgenesis and lung dysplasia, and the accumulating evidence that short-term benefits of available therapies may be outweighed by long-term detrimental effects on postnatal alveologenesis, the therapeutic implications of identifying a factor or pathway that can be targeted to stimulate normal alveolar development are profound., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Numerous publications have described the importance of bone morphogenetic protein (BMP) signaling in the specification of hematopoietic tissue in developing embryos. Here we investigate the full role of canonical BMP signaling in both adult and fetal liver hematopoiesis using conditional knockout strategies because conventional disruption of components of the BMP signaling pathway result in early death of the embryo. By targeting both Smad1 and Smad5, we have generated a double-knockout mouse with complete disruption of canonical BMP signaling. Interestingly, concurrent deletion of Smad1 and Smad5 results in death because of extrahematopoietic pathologic changes in the colon. However, Smad1/Smad5-deficient bone marrow cells can compete normally with wild-type cells and display unaffected self-renewal and differentiation capacity when transplanted into lethally irradiated recipients. Moreover, although BMP receptor expression is increased in fetal liver, fetal liver cells deficient in both Smad1 and Smad5 remain competent to long-term reconstitute lethally irradiated recipients in a multilineage manner. In conclusion, canonical BMP signaling is not required to maintain either adult or fetal liver hematopoiesis, despite its crucial role in the initial patterning of hematopoiesis in early embryonic development.

In an effort to define the biological functions of COMP, a functional genetic screen was performed. This led to the identification of extracellular matrix protein 1 (ECM1) as a novel COMP-associated partner. COMP directly binds to ECM1 both in vitro and in vivo. The EGF domain of COMP and the C-terminus of ECM1 mediate the interaction between them. COMP and ECM1 colocalize in the growth plates invivo. ECM1 inhibits chondrocyte hypertrophy, matrix mineralization, and endochondral bone formation, and COMP overcomes the inhibition by ECM1. In addition, COMP-mediated neutralization of ECM1 inhibition depends on their interaction, since COMP largely fails to overcome the ECM1 inhibition in the presence of the EGF domain of COMP, which disturbs the association of COMP and ECM1. These findings provide the first evidence linking the association of COMP and ECM1 and the biological significance underlying the interaction between them in regulating endochondral bone growth., (Copyright 2010 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.)

Pregnant sows were fed a control diet (CON, 0.15 mg deoxynivalenol (DON) and 0.0035 mg zearalenone (ZON) per kg diet) or diet containing 15% of Fusarium toxin contaminated triticale (MYCO, 4.42 mg DON and 0.048 mg ZON per kg diet) during days 35-70 of gestation. All sows were fed in a restricted feeding regimen with the same amount of feed (2000 g/d) over the whole study. At the end of the experiment, fetuses were delivered by Caesarian section and samples of spleen and liver of euthanized sows and fetuses were analyzed. At terminal necropsy, no macroscopic lesion was observed in any organ of either sows or fetuses. The histopathological data indicated significant alteration only in elevated iron staining in the red pulp of spleens in sows of MYCO group after 35 days of feeding. The presence of hemosiderin particles in the spleen sections was confirmed by transmission electron microscopical investigation and by an enhanced Fe2+ concentration in spleen. A glycogen increase (p<0.05) was found in liver cells of fetuses in the experimental group. Together, the results provide evidence of spleen dysfunction (hemosiderosis) in sows fed a Fusarium toxin-contaminated wheat, however, with absence of clinical signs. Enhanced glycogen and an impairment of mitochondria in liver of fetuses was present when their mothers consumed the MYCO diet.

Exponential improvements in imaging techniques over the last ten years, through patients' and physicians' wishes for less invasive fetal work-up, now allow us to better explore and understand fetal lung physiology during pregnancy. Diagnostic and prognostic consequences at stake are huge, especially for fetuses at risk of pulmonary hypoplasia. We will decline in three parts (normal lung, malformative lung and pulmonary hypoplasia), through a review of the literature and at the light of our experience, the potentialities and limitations of all imaging modalities (Ultrasound, Doppler, 3D, MRI). Then, we will dwell on future leads and the need for large-scale collaborative studies.

Red cells are required not only for adult well-being but also for survival and growth of the mammalian embryo beyond early postimplantation stages of development. The embryo's first "primitive" erythroid cells, derived from a transient wave of committed progenitors, emerge from the yolk sac as immature precursors and differentiate as a semisynchronous cohort in the bloodstream. Surprisingly, this maturational process in the mammalian embryo is characterized by globin gene switching and ultimately by enucleation. The yolk sac also synthesizes a second transient wave of "definitive" erythroid progenitors that enter the bloodstream and seed the liver of the fetus. At the same time, hematopoietic stem cells within the embryo also seed the liver and are the presumed source of long-term erythroid potential. Fetal definitive erythroid precursors mature in macrophage islands within the liver, enucleate, and enter the bloodstream as erythrocytes. Toward the end of gestation, definitive erythropoiesis shifts to its final location, the bone marrow. It has recently been recognized that the yolk sac-derived primitive and fetal definitive erythroid lineages, like their adult definitive erythroid counterpart, are each hierarchically associated with the megakaryocyte lineage. Continued comparative studies of primitive and definitive erythropoiesis in mammalian and nonmammalian embryos will lead to an improved understanding of terminal erythroid maturation and globin gene regulation.

Eleven pregnant sows with a body weight between 153 and 197 kg were fed a control diet (CON, 0.15 mg DON and 0.0035 mg ZON/kg diet) or a diet containing 15% of Fusarium toxin contaminated triticale (MYCO, 4.42 mg DON and 0.048 mg ZON/kg diet) in the period of day 35 and 70 of gestation. The indirect effect of feed intake was separated from the direct effects of the Fusarium toxins by the restricted feeding regimen where all sows were fed the same amount of feed (2000 g/d) over the whole study. At the end of experiment, fetuses were delivered by Caesarian section and samples of serum, bile, urine, liver, kidney and spleen of euthanatized sows and fetuses were taken to analyze the concentrations of DON, ZON and their metabolites. Feeding the Fusarium toxin contaminated diet to pregnant sows caused neither adverse effects on performance, organ weights and maintenance of pregnancy of sows nor on fetus weight and length. Furthermore, no teratogenic or embryolethal effects could be observed in the MYCO group. Hematological and clinical-chemical parameters of sows and fetuses were not affected by feeding, with the exception of significantly lower GLDH (glutamate dehydrogenase) serum activities in MYCO sows. The carry over of DON and ZON from the diet to the sow or fetus tissues was calculated by the diet ratio (sum of concentrations of all metabolites in the physiological specimen divided by the dietary toxin concentration), while the fetus ratio was evaluated by the sum of concentrations of all metabolites in the physiological specimen of the fetus divided by that of the sows. DON and deepoxy-DON were found in urine, bile, serum, liver, kidney and spleen of sows of the MYCO group, but not in the bile of fetuses (spleen not analyzed). ZON and its metabolite alpha-zearalenol (alpha-ZOL) were detected in urine and bile of sows, while all specimens of fetuses as well as serum and liver of sows were negative for ZON metabolites. The maximum diet ratios for urine and bile in sows of the MYCO group were 0.84 and 0.05 for DON metabolites and 1.2 and 3.8 for ZON metabolites, underscoring the differences in metabolism and excretion of both toxins. The maximum diet ratio of DON and deepoxy-DON into liver, kidney and spleen of MYCO sows were 0.003, 0.007 and 0.003, respectively. The maximum fetus ratio of DON and deepoxy-DON into urine, bile, serum, liver and kidney of fetuses were 0.006, 0, 0.5, 0.88, and 0.33, while the maximum placental ratio (sum of toxin concentrations in the physiological specimen of the fetus divided by the toxin serum concentration of the sow) were 0.64, 0, 0.50, 0.70 and 0.52, respectively. Therefore, it can be concluded that the developing fetus is exposed to DON between the gestation days 35 and 70 when the sows are fed a Fusarium toxin contaminated diet. ZON concentration in the MYCO diet was too low to get reliable results for fetus or placental ratios.

In utero hematopoietic-cell transplantation (IUHCT) can induce donor-specific tolerance to facilitate postnatal transplantation. Induction of tolerance requires a threshold level of mixed hematopoietic chimerism. CD26 is a peptidase whose inhibition increases homing and engraftment of hematopoietic cells in postnatal transplantation. We hypothesized that CD26 inhibition would increase donor-cell homing to the fetal liver (FL) and improve allogeneic engraftment following IUHCT. To evaluate this hypothesis, B6GFP bone marrow (BM) or enriched hematopoietic stem cells (HSCs) were transplanted into allogeneic fetal mice with or without CD26 inhibition. Recipients were analyzed for FL homing and peripheral-blood chimerism from 4 to 28 weeks of life. We found that CD26 inhibition of donor cells results in (1) increased homing of allogeneic BM and HSCs to the FL, (2) an increased number of injected animals with evidence of postnatal engraftment, (3) increased donor chimerism levels following IUHCT, and (4) a competitive engraftment advantage over noninhibited congenic donor cells. This study supports CD26 inhibition as a potential method to increase the level of FL homing and engraftment following IUHCT. The resulting increased donor chimerism suggests that CD26 inhibition may in the future be used as a method of increasing donor-specific tolerance following IUHCT.

While during the first trimester of pregnancy natural killer (NK) cells represent the most abundant lymphocyte population in the decidua, their actual function at this site is still debated. In this study we analyzed NK cells isolated from decidual tissue for their surface phenotype and functional capability. We show that decidual NK (dNK) cells express normal surface levels of certain activating receptors, including NKp46, NKG2D, and 2B4, as well as of killer cell immunoglobulin-like receptors (KIRs) and CD94/NKG2A inhibitory receptor. In addition, they are characterized by high levels of cytoplasmic granules despite their CD56(bright) CD16- surface phenotype. Moreover, we provide evidence that in dNK cells, activating NK receptors display normal triggering capability whereas 2B4 functions as an inhibitory receptor. Thus, cross-linking of 2B4 resulted in inhibition of both cytolytic activity and interferon-gamma (IFN-gamma) production. Clonal analysis revealed that, in the majority of dNK cell clones, the 2B4 inhibitory function is related to the deficient expression of signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) mRNA. Moreover, biochemical analysis revealed low levels of SAP in the dNK polyclonal population. This might suggest that dNK cells, although potentially capable of killing, are inhibited in their function when interacting with cells expressing CD48.

Fetal brain Magnetic Resonance Imaging (MRI) is a new technique of growing interest, with a high potential to detect prenatal central nervous system abnormalities. This requires an accurate knowledge of the normal morphological sequence of brain development. In this paper we studied the cortical development of post-mortem normal fetal brains, correlating MRI estimations of fetal age with in vitro anatomical and anthropometric measurements. Ten post-mortem fetal heads were submitted to MRI. Maturational state of sulci and gyri and gray-white matter differentiation were analysed in the MRIs and by dissection of the brains. The findings were correlated with the previously estimated ages of the fetuses, which varied between 17 and 38 weeks. Consistency between methods was assessed employing intraclass correlation coefficient and Bland-Altman plots, with a 95% confidence interval. Estimations of fetal age obtained by MRI were very similar to those achieved by anthropometric measurements or by considering anatomical parameters. Gyral development proved to be more precise than gray-white matter differentiation for this purpose. Fetal MRI proved to be as reliable as the macroscopic anatomical examination for depicting normal cortical developmental sequence and age, suggesting that this technique may be a suitable option for achieving precise information about the morphology of human brains along the gestational period.

Objective: Nuchal edema (NE) is a clinical indicator for aneuploidy, cardiovascular anomalies, and several genetic syndromes. Its etiology, however, is unknown. In the nuchal area, the endothelium of the jugular lymphatic sacs (JLS) develops by budding from the blood vascular endothelium of the cardinal veins. Abnormal distension of the jugular sacs is associated with NE. We hypothesize that a disturbed lymphatic endothelial differentiation and sac formation causes NE. We investigated endothelial differentiation of the jugular lymphatic system in human and mouse species with NE., Methods: Aneuploid human fetuses (trisomy 21; trisomy 18) were compared with euploid controls (gestational age 12 to 18 weeks). Trisomy 16 mouse embryos were compared with wild type controls (embryonic day 10 to 18). Trisomy 16 mice are considered an animal model for human trisomy 21. Endothelial differentiation was investigated by immunohistochemistry using lymphatic markers (prox-1, podoplanin, lymphatic vessel endothelial hyaluronan receptor [LYVE]-1) and en blood vessel markers (neuropilin [NP]-1 and ligand vascular endothelial growth factor [VEGF]-A). Smooth muscle actin (SMA) was included as a smooth muscle cell marker., Results: We report a disturbed venous-lymphatic phenotype in aneuploid human fetuses and mouse embryos with enlarged jugular sacs and NE. Our results show absent or diminished expression of the lymphatic markers Prox-1 and podoplanin in the enlarged jugular sac, while LYVE-1 expression was normal. Additionally, the enlarged JLS showed blood vessel characteristics, including increased NP-1 and VEGF-A expression. The lumen contained blood cells and smooth muscle cells lined the wall., Conclusion: A loss of lymphatic identity seems to be the underlying cause for clinical NE. Also, abnormal endothelial differentiation provides a link to the cardiovascular anomalies associated with NE.

Treatment with excessive amounts of Vitamin A during maternity induces fetal malformations. However, it is unclear whether these malformations are due to gene mutations or not. Using transgenic mice (containing lacZ gene showing beta-galactosidase enzymatic activity), we planned to observe whether gene mutations occur in the fetal tissues after treatment during maternity with Vitamin A (retinol palmitate). On the 11th day of pregnancy, mothers were given 30 mg (group 2), 150 mg (group 3) and 300 mg (group 4) of Vitamin A/kg body weight orally. Fetuses obtained on the 18th day of gestation showed malformations, such as cleft palate, origodactyly, brachydactyly and ectromeria. Most notably, cleft palate occurred dose dependently. The incidental rates were 100% in group 4, 58% in group 3 and 6% in group 2. The number of dead and absorbed fetuses also increased dose dependently with the treatments. DNA (integrated vectors containing lacZ genes) extracted from each fetus showed Vitamin A-induced lacZ mutations, especially in the malformed fetuses. The mutation frequencies were 4.99x10(-5) in group 4, 5.28x10(-5) in group 3 and 4.26x10(-5) in group 2. The frequencies of group 3 were significantly higher (p<0.05) than that of the controls (group 1), 2.79x10(-5). Maternal treatment with Vitamin A (150 mg/kg of body weight) was carried out on the 11th day of pregnancy. Fetuses obtained on the 14th day of gestation showed a much higher incidence of mutation, approximately 8.91x10(-5) (group 6) that was significantly higher (p<0.0001) than those from the controls (group 5), 2.94x10(-5). The present study indicates a possibility that hypervitaminosis A-induced fetal malformation and death might be caused by gene mutations.

The stem-cell leukemia gene (SCL/tal1) is essential for the formation of all blood lineages. SCL is first expressed in mesodermal cells that give rise to embryonic blood cells, and continues to be expressed in fetal and adult hematopoietic stem cells (HSCs). However, SCL is not required for the maintenance of established long-term repopulating (LTR) HSCs in the adult. The time point at which HSC development becomes SCL independent has not been defined. Tyrosine kinase with immunoglobulin and epidermal growth factor homology domains-2 (Tie2) expression appears in hemogenic and vasculogenic sites shortly after SCL. We therefore used the Tie2Cre mouse to inactivate SCL early during embryonic and fetal hematopoiesis. Tie2Cre completely inactivated SCL in yolk sac, the aortagonad-mesonephros (AGM) region, and fetal liver hematopoietic cells and circulating blood cells. However, the fetal liver was colonized by functional LTR-HSCs. Yet SCL remained crucial for proper differentiation of both primitive and definitive red cells and megakaryocytes. These results indicate that the SCL-dependent phase of HSC development ends before Tie2Cre-mediated gene ablation becomes effective.