Добірка наукової літератури з теми "Placenta – Physiologie"

We investigated expression of cholecystokinin (CCK) in humans and mice, and the bitter taste receptor TAS2R14 in the human placenta. Because CCK and gastrin activate the CCKBR receptor, we also explored placental gastrin expression. Finally, we investigated calcium signaling by CCK and TAS2R14. By RT-PCR, we found CCK/Cck and GAST/Gast mRNA expression in both normal human and mouse placentas, as well as in human trophoblast cell lines (TCL). Although both Cckar and – br mRNA were expressed in the mouse placenta, only CCKBR mRNA was detected in the human placenta and TCL. mRNA expression for TAS2R14 was also observed in the human placenta and TCL. Using immunohistochemistry, CCK protein was localized to the syncytiotrophoblast (ST) and extravillous trophoblast (EVT) in the human term placenta, and to trophoblast glycogen cells in mouse and human placentas. Gastrin and TAS2R14 proteins were also observed in ST and EVT of the human placenta. Both sulfated and nonsulfated CCK elicited a comparable rise in intracellular calcium in TCL, consistent with CCKBR expression. Three TAS2R14 agonists, flufenamic acid, chlorhexidine, and diphenhydramine, also evoked rises in intracellular calcium in TCL. These results establish CCK, gastrin, and their receptor(s) in both human and mouse placentas, and TAS2R14 in the human placenta. Both CCK and TAS2R14 agonists increased intracellular calcium in human TCL. Although the roles of these ligands and receptors, and their potential cross talk in normal and pathological placentas, are currently unknown, this study opens new avenues for placental research.

A well-functioning placenta is crucial for normal gestation and regulates the nutrient, gas, and waste exchanges between the maternal and fetal circulations and is an important endocrine organ producing hormones that regulate both the maternal and fetal physiologies during pregnancy. Placental insufficiency is implicated in spontaneous preterm birth (SPTB). We proposed that deficits in the capacity of the placenta to maintain bioenergetic and metabolic stability during pregnancy may ultimately result in SPTB. To explore our hypothesis, we performed a RNA-seq study in male and female placentas from women with SPTB (<36 weeks gestation) compared to normal pregnancies (≥38 weeks gestation) to assess the alterations in the gene expression profiles. We focused exclusively on Black women (cases and controls), who are at the highest risk of SPTB. Six hundred and seventy differentially expressed genes were identified in male SPTB placentas. Among them, 313 and 357 transcripts were increased and decreased, respectively. In contrast, only 61 differentially expressed genes were identified in female SPTB placenta. The ingenuity pathway analysis showed alterations in the genes and canonical pathways critical for regulating inflammation, oxidative stress, detoxification, mitochondrial function, energy metabolism, and the extracellular matrix. Many upstream regulators and master regulators important for nutrient-sensing and metabolism were also altered in SPTB placentas, including the PI3K complex, TGFB1/SMADs, SMARCA4, TP63, CDKN2A, BRCA1, and NFAT. The transcriptome was integrated with published human placental metabolome to assess the interactions of altered genes and metabolites. Collectively, significant and biologically relevant alterations in the transcriptome were identified in SPTB placentas with fetal sex disparities. Altered energy metabolism, mitochondrial function, inflammation, and detoxification may underly the mechanisms of placental dysfunction in SPTB.

In recent years, there have been concerns about human reproductive disorders. Physiological adaptations are crucial for optimal fetal development during pregnancy. The widespread consumption of caffeine by pregnant women raises questions about its impact on maternal physiology and fetal development. Hence, the objective of this study was to evaluate the histological assessment of placenta development following intrauterine exposure to caffeine in adult Wistar rats using appropriate standard techniques. On each gestational day (GD13, GD15, GD17, and GD19), five (5) animals were sampled from each group and their placentas were harvested for histological assessment. The Maternal weight, Fetal Crown Rump Length, Placental weight, Placental diameter major, Placental diameter minor, and fetal weight were taken on the harvested placenta. Results showed varying alterations in the histomorphology of the placenta ranging from delayed differentiation of glycogen cells, dilated and congested blood vessels, vacuolar degeneration of glycogen cell islands, poor development of the labyrinth zone, and dilated fetal capillaries. In conclusion, there is histomorphological evidence that caffeine administration has deleterious effects on the development of the placenta in Wistar rats.

Protocadherins are transmembrane proteins exhibiting homophilic adhesive activities through their extracellular domain. Protocadherin 12 ( Pcdh12) is expressed in angiogenic endothelial cells, mesangial cells of kidney glomeruli, and glycogen cells of the mouse placenta. To get insight into the role of this protein in vivo, we analyzed PCDH12-deficient mice and investigated their placental phenotype. The mice were alive and fertile; however, placental and embryonic sizes were reduced compared with wild-type mice. We observed defects in placental layer segregation and a decreased vascularization of the labyrinth associated with a reduction in cell density in this layer. To understand the molecular events responsible for the phenotypic alterations observed in Pcdh12−/− placentas, we analyzed the expression profile of embryonic day 12.5 mutant placentas compared with wild-type placentas, using pangenomic chips: 2,289 genes exhibited statistically significant changes in expressed levels due to loss of PCDH12. Functional grouping of modified genes was obtained by GoMiner software. Gene clusters that contained most of the differentially expressed genes were those involved in tissue morphogenesis and development, angiogenesis, cell-matrix adhesion and migration, immune response, and chromatin remodeling. Our data show that loss of PCDH12 leads to morphological alterations of the placenta and to notable changes in its gene expression profile. Specific genes emerging from the microarray screen support the biological modifications observed in PCDH12-deficient placentas.

Maternal cadmium exposure induces fetal growth restriction (FGR), but the underlying mechanisms remain largely unknown. The placenta is the main organ known to protect the fetus from environmental toxins such as cadmium. In this study, we examine the role of the two key placental factors in cadmium-induced FGR. The first is placental enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which is known to protect the fetus from exposure to high cortisol levels and subsequently FGR, and the second the cadmium binding/sequestering proteins metallotheionein (MT)-I and -II. Using the MT-I/II −/− mouse model, pregnant mice were administered cadmium, following which pups and placentas were collected and examined. MT-I/II−/− pups exposed to cadmium were significantly growth restricted, but neither placental weight nor 11β-HSD2 was altered. Although cadmium administration did not result in any visible structural changes in the placenta, increased apoptosis was detected in MT-I/II−/− placentas following cadmium exposure, with a significant increase in levels of both p53 and caspase 3 proteins. Additionally, glucose transporter (GLUT1) was significantly reduced in MT-I/II−/− placentas of pups exposed to cadmium, whereas zinc transporter (ZnT-1) remained unaltered. Taken together, these results demonstrate that MT-I/II−/− mice are more vulnerable to cadmium-induced FGR. The present data also suggest that increased apoptosis and reduced GLUT1 expression in the placenta contribute to the molecular mechanisms underlying cadmium-induced FGR.

Clinical manifestations of coronavirus disease 2019 (COVID-19) in pregnant women are diverse, and little is known of the impact of the disease on placental physiology. Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has been detected in the human placenta, and its binding receptor ACE2 is present in a variety of placental cells, including endothelium. Here, we analyze the impact of COVID-19 in placental endothelium, studying by immunofluorescence the expression of von Willebrand factor (vWf), claudin-5, and vascular endothelial (VE) cadherin in the decidua and chorionic villi of placentas from women with mild and severe COVID-19 in comparison to healthy controls. Our results indicate that: (1) vWf expression increases in the endothelium of decidua and chorionic villi of placentas derived from women with COVID-19, being higher in severe cases; (2) Claudin-5 and VE-cadherin expression decrease in the decidua and chorionic villus of placentas from women with severe COVID-19 but not in those with mild disease. Placental histological analysis reveals thrombosis, infarcts, and vascular wall remodeling, confirming the deleterious effect of COVID-19 on placental vessels. Together, these results suggest that placentas from women with COVID-19 have a condition of leaky endothelium and thrombosis, which is sensitive to disease severity.

Women residing at high altitudes deliver infants of lower birth weight than at sea level. Birth weight correlates with placental system A-mediated amino acid transport capacity, and severe environmental hypoxia reduces system A activity in isolated trophoblast and the mouse placenta. However, the effect of high altitude on human placental amino acid transport remains unknown. We hypothesized that microvillous membrane (MVM) system A and system L amino acid transporter activity is lower in placentas of women living at high altitude compared with low-altitude controls. Placentas were collected at term from healthy pregnant women residing at high altitude (HA; >2,500 m; n = 14) or low altitude (LA; <1,700 m; n = 14) following planned, unlabored cesarean section. Birth weight, but not placenta weight, was 13% lower in HA pregnancies (2.88 ± 0.11 kg) compared with LA (3.30 ± 0.07 kg, P < 0.01). MVM erythropoietin receptor abundance, determined by immunoblot, was greater in HA than in LA placentas, consistent with lower placental oxygen levels at HA. However, there was no effect of altitude on MVM system A or L activity, determined by Na+-dependent [14C]methylaminoisobutyric acid uptake and [3H]leucine uptake, respectively. MVM abundance of glucose transporters (GLUTs) 1 and 4 and basal membrane GLUT4 were also similar in LA and HA placentas. Low birth weights in the neonates of women residing at high altitude are not a consequence of reduced placental amino acid transport capacity. These observations are in general agreement with studies of IUGR babies at low altitude, in which MVM system A activity is downregulated only in growth-restricted babies with significant compromise. NEW & NOTEWORTHY Babies born at high altitude are smaller than at sea level. Birth weight is dependent on growth in utero and, in turn, placental nutrient transport. We determined amino acid transport capacity in placentas collected from women resident at low and high altitude. Altitude did not affect system A amino acid transport across the syncytiotrophoblast microvillous membrane, suggesting that impaired placental amino acid transport does not contribute to reduced birth weight in this high-altitude population.

The fetus requires large amounts of volume when weaning from cardiac bypass. This suggests that placental vasculature can act as a large capacitor in the fetal circulation. To assess placental compliance of fetal lambs, seven isolated in situ lamb placentas were placed on extracorporeal circulation. Umbilical artery blood flow was varied from 0 to 350 ml · min−1· kg fetal wt−1. Because the extracorporeal circuit is a closed system, volume changes in the placenta induced by umbilical artery pressure changes were measured from reciprocal volume changes in the reservoir. There was a wide range of change in absolute volume of blood within the fetal placental compartment (216.4 ± 29.3 ml). Placental compliance was linear over the entire range of pressure changes exerted on the placental vasculature ( r2= 0.83, P = 0.0001). This indicates that the placenta is a unique and sensitive capacitor in the fetal circulation. This information is important clinically because it establishes that aggressive resuscitation of the fetus using volume may be necessary when weaning the fetus from cardiac bypass.

Abstract Objectives To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy. Methods Pregnant women with COVID-19 delivering between March 18, 2020, and May 5, 2020, were identified. Placentas were examined and compared to historical controls and women with placental evaluation for a history of melanoma. Results Sixteen placentas from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were examined (15 with live birth in the third trimester, 1 delivered in the second trimester after intrauterine fetal demise). Compared to controls, third trimester placentas were significantly more likely to show at least one feature of maternal vascular malperfusion (MVM), particularly abnormal or injured maternal vessels, and intervillous thrombi. Rates of acute and chronic inflammation were not increased. The placenta from the patient with intrauterine fetal demise showed villous edema and a retroplacental hematoma. Conclusions Relative to controls, COVID-19 placentas show increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. Only 1 COVID-19 patient was hypertensive despite the association of MVM with hypertensive disorders and preeclampsia. These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.

Vascularity is increased in placentas from high- compared with low-altitude pregnancies. An angiogenic response to hypoxia may protect an organ from further hypoxic insult by increasing blood flow and oxygen delivery to the tissue. We hypothesized that increased placental vascularity is sufficient to adapt to high altitude. Therefore, indexes of hypoxic stress would not be present in placentas from successful high-altitude pregnancies. Full-thickness placental biopsies were 1) collected and frozen in liquid nitrogen within 5 min of placental delivery and 2) fixed in formalin for stereologic analyses at high (3,100 m, n = 10) and low (1,600 m, n = 10) altitude. Hypoxia-inducible transcription factor (HIF-1) activity was analyzed by ELISA. Western blot analyses were used to evaluate HIF-1α, HIF-1β, HIF-2α, von Hippel-Lindau protein, VEGF, Flt-1, enolase, and GAPDH. Magnetic resonance spectroscopy was used to evaluate endogenous metabolism. The ratio of placental capillary surface density to villous surface density was 70% greater at high compared with low altitude. HIF-1 activity and HIF-1-associated proteins were unchanged in placentas from high- vs. low-altitude pregnancies. Placental expression of HIF-1-mediated proteins VEGF, Flt-1, enolase, and GAPDH were unchanged at high vs. low altitude. Succinate, GSH, phosphomonoesters, and ADP were elevated in placenta from high compared with low altitude. Placentas from uncomplicated high-altitude pregnancies have greater vascularity and no indication of significant hypoxic stress at term compared with placentas from low altitude.

Le placenta est un organe provisoire joignant la mère et le fœtus qui transfère l’oxygène et des nutriments de la mère au fœtus et permet l’évacuation de l’anhydride carbonique et des produits du métabolisme du fœtus. Le but de notre travail était d’étudier la fonction de transfert des tissus placentaires selon son développement en se basant sur les images ultrasonores. Nous avons développé au cours de ce travail une nouvelle approche de la classification du développement placentaire en ultrasons par des techniques de traitement d’images avancées basée sur une représentation par réseau neuronal. Le modèle réalisé par la transformée en ondelettes basé sur le réseau neuronal MLP représente donc un outil efficace et rapide répondant à nos critères et bien adapté à nos applications concernant l’étude de la maturation placentaire. L’application du modèle réalisée en cas de traitement d’images placentaires ouvre des portes intéressantes en terme de classification des grades placentaires afin d’identifier des stades de maturation autorisant la définition d’une maturation normale et de classes à risque
The placenta is a temporary organ joins the mother and the fœtus, which transfers oxygen from the mother to the foetus, allows the evacuation of the carbon dioxide and the products of foetus metabolism. The goal of our work is to study the transfer function of placental development using ultrasound images. A new approach is developed during this work to classify the placental development by image processing techniques based on supervised neural network. The realized model by the wavelet transform based on MLP neural network, represents an effective tool answering our criteria and adapted to our applications concerning the study of placental maturation. The realized model application in the event of placental image processing opens interesting doors in terms of placental grades classification in order to identify the stages of maturation, authorizing the definition of a normal maturation and an abnormal maturation

La prééclampsie (PE) est une pathologie obstétricale complexe associée à un défaut de placentation. Selon la littérature, le placenta anormalement développé libèrerait des facteurs qui induiraient une dysfonction endothéliale maternelle. Nous avons émis comme hypothèse qu’une accumulation de sorbitol, un sucre hyperosmotique produit par la voie des polyols, pourrait induire la libération par le placenta de sFlt-1, un facteur anti-angiogénique antagoniste du VEGF en PE. Nous avons comparé les niveaux d’expression d’ARNm et de protéines de AKR1B1 et SORD, les deux enzymes impliquées dans la voie des polyols, dans les placentas de mères ayant eu une grossesse normotensive (groupe témoin) ou prééclamptique par RT-PCR quantitatif et par immunobuvardage respectivement. Nous les avons ensuite localisées par immunohistochimie. Nos résultats suggèrent que la voie des polyols serait altérée au niveau de la membrane amniochorionique des placentas issus de grossesses prééclamptiques, ce qui pourrait favoriser une accumulation de sorbitol à l’interface fœto-maternelle.
Preeclampsia (PE) is a complex obstetrical pathology associated to a defective placentation. The abnormally developed placenta is believed to release factors causing a maternal endothelial dysfunction. We hypothesized that an accumulation of sorbitol, a hyperosmotic sugar produced through the polyol pathway, could induce the release by the placenta of sFlt-1, an antagonist of the angiogenic factor VEGF in PE. We compared mRNA and protein expression levels of AKR1B1 and SORD, the two enzymes of the polyol pathway, in placentas from normotensive (control) and PE pregnancies by quantitative RT-PCR and immunoblotting respectively. Then, we localized the two enzymes by immunohistochemistry. Our results suggest that polyol pathway is altered in amniochorionic membranes from PE pregnancies, and that this phenomenon would promote sorbitol accumulation at the foeto-maternal interface.

La naissance est une période à risque qui met en jeux de multiples mécanismes qui permettent une transition de la vie fœtale et la vie extra-utérine. Chaque année, dans les conséquences d'une mauvaise adaptation à la vie extra-utérine et la persistance de résistances vasculaires pulmonaires trop élevées, 1 million de nouveau-né décède dans les 24 premières heures de vie. Dix pourcents des nouveau-nés requièrent une assistance médicale en salle de naissance. Le clampage du cordon ombilical retardé entre 60 et 180 secondes après la naissance est désormais recommandé pour toutes les situations où le nouveau-né, à terme comme prématuré, s'adapte bien à son nouvel environnement diminuant entre autres, le risque d'anémie ferriprive des premiers mois de vie. La hernie de coupole diaphragmatique (HCD) est une malformation cardio-pulmonaire secondaire à un défaut de fermeture du muscle diaphragmatique. Elle entraine une mortalité élevée et responsable d'un trouble de l'adaptation à la vie extra-utérine. Dans les situations de réanimation en salle de naissance, du fait du manque de données physiologiques et cliniques, il n'est pas encore recommandé de maintenir les échanges fœto-placentaires en parallèle de l'initiation de la réanimation. Dans ce travail de thèse, nous posons l'hypothèse que le placenta puisse participer à l'oxygénation et à la décarboxylation du nouveau-né le temps que la circulation cardio-pulmonaire du nouveau-né se mette en place. Le but de ce travail est d'étudier la physiologie de l'hémodynamique et des échanges gazeux transplacentaires lors d'une réanimation à cordon intact (RCI) dans un modèle d'agneau sain et dans un modèle d'agneau porteur de hernie diaphragmatique. Les objectifs étaient (1) de présenter l'étude clinique « CHIC » évaluant l'impact de la RCI chez le nouveau-né porteur de HCD, (2) mettre en place le modèle expérimental d'agneau HCD, (3) explorer la faisabilité et la durée maximale d'une réanimation à cordon intact chez l'agneau, (4) étudier l'évolution de l'hémodynamique et des échanges gazeux transplacentaires au cours d'une RCI dans un modèle d'agneau sain et porteur d'une HCD. Nous avons démontré que l'hémodynamique fœto-placentaire pouvait était stable (débits veineux ombilicaux, résistances vasculaire transplacentaires) jusque 1 heure après la mise en place d'une RCI. Dans un modèle d'agneau hernie diaphragmatique, où l'échangeur pulmonaire ne permet pas d'assurer normalement une augmentation rapide de la pression partielle artérielle en oxygène (PaO2), le placenta permettait d'assurer une oxygénation et une décarboxylation tout au long de la réanimation avec un apport en oxygène par le placenta stable pendant 1 heure (2,7 [2,2-3,3] ml/kg/min). A l'inverse, dans un modèle physiologique, le maintien d'une circulation placentaire est associé à une diminution de la pression artérielle systémique de l'ordre de 20% comparée au groupe hernie diaphragmatique (p<0,05). L'augmentation de la PaO2 dans ce groupe est associée avec une diminution des apports en oxygène par le placenta. Le clampage du cordon entraine dans ce groupe une élévation de la PaO2 et une diminution de la capnie. L'ensemble de ces travaux apporte une base physiologique essentielle à la pratique d'une réanimation à cordon intact et souligne l'importance de stratégies de réanimation individualisées en fonction des conditions cliniques spécifiques
Birth is a critical period during which numerous mechanisms are engaged to enable the transition from fetal to extrauterine life. Each year, due to poor adaptation to this transition and the persistence of elevated pulmonary vascular resistance, 1 million newborns die within the first 24 hours of life. Ten percent of newborns require medical assistance in the delivery room. Delayed umbilical cord clamping, between 60 and 180 seconds after birth, is now recommended in all situations where the newborn, whether full-term or premature, adapts well to the new environment. This practice notably reduces the risk of iron deficiency anemia in the first months of life.Congenital diaphragmatic hernia (CDH) is a cardiopulmonary malformation caused by a defect in the closure of the diaphragm, leading to high mortality and impairing adaptation to extrauterine life. In delivery room resuscitation scenarios, the lack of physiological and clinical data has not yet allowed for the recommendation of maintaining feto-placental circulation alongside the initiation of resuscitation.In this thesis, we hypothesize that the placenta could contribute to oxygenation and decarboxylation of the newborn until the cardio-pulmonary circulation is established. The aim of this work is to study the physiology of hemodynamics and transplacental gas exchange during intact cord resuscitation (ICR) in a healthy lamb model and in a lamb model with CDH. The specific objectives were: (1) to present the clinical study “CHIC” evaluating the impact of ICR in newborns with CDH; (2) to establish an experimental lamb model of congenital diaphragmatic hernia; (3) to explore the feasibility and maximum duration of intact cord resuscitation in this model; and (4) to study the evolution of hemodynamics and transplacental gas exchange during ICR in both healthy and CDH lamb models.We demonstrated that feto-placental hemodynamics (umbilical venous flow, transplacental vascular resistance) remained stable up to one hour after the initiation of ICR. In the lamb model with diaphragmatic hernia, where the pulmonary exchange system cannot adequately increase arterial partial oxygen pressure (PaO2), the placenta provided sufficient oxygenation and decarboxylation throughout the resuscitation, with stable placental oxygen delivery for one hour (2.7 [2.2-3.3] ml/kg/min). Conversely, in the physiological model, maintaining placental circulation was associated with a 20% decrease in systemic arterial pressure compared to the CDH group (p<0.05). The increase in PaO2 in this group was associated with a decrease in placental oxygen delivery. Cord clamping in this group led to an increase in PaO2 and a decrease in carbon dioxide levels. These findings provide an essential physiological basis for the practice of intact cord resuscitation and highlight the importance of individualized resuscitation strategies based on specific clinical conditions

The placenta is a transient organ, essential for the growth and development of the fetus throughout pregnancy. This temporary organ brings maternal and fetal blood circulation into close proximity, which allows for the exchange of oxygen, carbon dioxide, waste, and other essential nutrients. Despite constant influences by internal and external factors, the human placenta has a defined life span of approximately 280 days. From conception, through to term, the placenta undergoes chronological aging, which is regulated by a range of cellular processes. Advanced placental aging and cellular senescence have been known to contribute to the pathophysiology of preterm birth, fetal growth restriction and may cause an increased risk of stillbirth. However, the molecular mechanisms behind placental aging are still poorly understood. As a key regulator of cell homeostasis, mitochondria have been recognised as an important mediator of age-related disease processes through the production of reactive oxygen species which activate mechanisms that induce cellular senescence. Currently, we do not understand the molecular link between cellular aging processes and the role of mitochondria in chronological and pathological placental aging. Therefore, this research aimed to, 1) identify key areas of mitochondrial physiology that change with placental development, 2) characterise a set of markers that define aging in the human placenta, 3) assess the role of the mitochondria in the placenta as it develops throughout a healthy pregnancy, 4) to measure the chosen markers of aging in placentas complicated by pregnancy pathologies. Chapter 1 presents a comprehensive review of the literature to date and highlights key gaps in our current knowledge. It sets the scene for the experimental chapters to follow. Chapter 2 provides the details of the methods and materials that have been used in the laboratory to generate the data presented in the results chapters. Chapter 3 explored the molecular changes within healthy and pathological placentas, through analysing large publicly available datasets. This chapter aimed to establish an understanding of placental aging and mitochondrial physiology through measuring mitochondrial biogenesis, dynamics, mitophagy, apoptosis and senescence transcripts. Furthermore, this chapter measured altered transcripts in an additional validation cohort consisting of placentas affected by term, preterm, post-term and FGR pregnancies. This study was a large-scale investigation across multiple datasets that identified altered TOMM2020, MFN1, and MFN2 expression throughout preterm, post-term and FGR pregnancies, which may be a contributing factor to placental insufficiency. It established key markers that influence mitochondrial physiology in placental aging, which informed future studies in this thesis. Chapter 4 focused on understanding healthy aging by measuring mitochondrial and senescent changes in term and post-term placenta. Post-term placentae from healthy pregnancies selectively retain highly functioning mitochondria through increases in mitochondrial dynamics proteins MFN1, MFN2 and mitochondrial complex specific proteins. This study directly associated mitochondrial adaptions with increases in cellular senescence in the placenta and may be the reason why some post-term pregnancies are healthy, whilst others turn pathological. These findings have helped to expand our knowledge of the role of mitochondria and healthy aging in the placenta. The current literature on placental aging has focused on comparing the differences between two timepoints in pregnancy, or healthy and complicated pregnancies. The reason being that it is nearly impossible to ethically collect healthy placental tissue from early in pregnancy. Even when these samples are collected, they are inherently impacted by factors which lead to early termination. Therefore, Chapter 5 used placental samples from an established rodent ontogeny model that were collected between mid- and term gestation, without pathologies. These placentas were used to understand the role of mitochondrial biology, senescence, and the ER and in the developing placenta. Markers associated with mitochondrial biogenesis, dynamics and senescence were differentially altered in healthy placentas collected throughout gestation, which was different to what was identified in previous chapters. Therefore, throughout different stages of pregnancy, mitochondria function differently compared to placentas from post-term and growth restricted pregnancies. Lastly, Chapter 6 measured the most differentially expressed genes from previous chapters in placentas complicated by preterm, term, post-term, fetal growth restriction (FGR), preterm preeclampsia (PE), FGR/ PE pregnancies. The aim of this chapter was to utilise MetaboAnalyst data software to identify relationships between genes related to mitochondria, ER and cellular senescence. This study revealed that placentas complicated by pathologies, PE and FGR have tremendously different transcription patterns, compared to the healthy controls. Although this study only investigated a small number of genes in a relatively small sample size, it revealed that the TOMM20/PARK2 ratio is a promising marker to discriminate between healthy placenta and placenta that have been affected by pregnancy pathologies. Overall, the findings in this thesis highlight the importance of mitochondrial alterations and cellular senescence within chronological and pathological aging of the placenta. Whilst the exact mechanisms of mitochondrial aging in the placenta still requires further investigation, MFN1, MFN2, TOMM20 and PARK2 are promising markers of placental aging and should be investigated in further models of placental insufficiency. This work provides the foundation for future work in mitochondrial aging within the human placenta.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Pharmacy & Med Sci
Griffith Health
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Le Bisphénol A (BPA) est un perturbateur endocrinien dont les effets développementaux observés chez les rongeurs soulèvent la question du risque pour la santé humaine relatif à une exposition fœtale au BPA. L’objectif de cette thèse est de déterminer les mécanismes toxicocinétiques impliqués dans l’exposition fœtale au BPA. La caractérisation in vivo dans un modèle intégratif ovin des expositions maternelles et fœtales au BPA et à ses métabolites ont permis d’identifier le transfert placentaire et le métabolisme fœto-placentaire comme les déterminants majeurs de l’exposition fœtale au BPA. Le transfert bidirectionnel du BPA à travers le placenta humain se fait par diffusion passive conduisant à un rapport maximal des concentrations plasmatiques de BPA libre entre le fœtus et sa mère de 1. En revanche, la perméabilité placentaire du BPA-G est très limitée, en particulier dans le sens materno-fœtal. Les activités de conjugaison hépatique du BPA ont été faibles chez le fœtus ovin à un stade précoce de gestation et ont augmenté au cours du développement. Par ailleurs la réactivation des conjugués du BPA mise en évidence ex vivo dans les gonades fœtales ovines pourrait conduire à une exposition locale au BPA actif. L’ensemble de ces données suggère que le début de la gestation pourrait représenter une fenêtre critique d’exposition au BPA
Bisphenol A (BPA) an endocrine disruptor interfering with developmental processes in rodents, raises the question of risk for human health related to fetal exposure to BPA. The goal of this work was to determine the toxicokinetic mechanisms involved in fetal exposure to BPA. The disposition of BPA and its metabolites in the maternal-placental-fetal unit in an in vivo ovine model enabled us to identify the placental transfer and the fetal-placental metabolism as the major determining factors of fetal exposure to BPA. Bidirectional placental transfer of BPA occurs by passive diffusion leading to a ratio of free BPA between the fetal and maternal plasma concentrations of about 1. By contrast, the permeability of BPA-G is very limited, particularly in materno-to-fetal direction. The hepatic conjugation activities were very low in ovine fetus at an early stage of development and increased throughout pregnancy. Hydrolysis of BPA conjugates observed ex vivo into fetal ovine gonads could lead to local exposure to native BPA. Altogether, these results suggest that the early stage of pregnancy is a critical window of exposure for the developing fetus

Placenta is a transient association of the fetal and maternal tissues, that develops during pregnancy, in most viviparous animals. The evolution of placenta ensured the development of the fetus inside the womb of the mother, providing a protected environment for the development of the fetus, and preventing the loss of progeny due to unfavorable environmental conditions. Because it is strategically poised at the maternal and fetal interface, the placenta is ideally suited to carry out alimentary, respiratory and excretory functions for the developing fetus. In addition, it serves as an immunological barrier preventing the rejection of the fetal semi-allograft, by the maternal immune system. Furthermore, the placenta elaborates a variety of protein, polypeptide and steroid hormones. These include growth factors, growth factor receptors, neuropeptides, opioids, progesterone and estrogen, whose secretion is dependent on the gestational age of the placenta and its differentiation status. The human placenta, adapts itself remarkably to cater to the changing requirements of the developing fetus. For instance, during the first trimester of pregnancy, the placenta is an actively dividing, a highly invasive and a rapidly differentiating organ; while near term, it represents a fully differentiated and a non-invasive unit. Furthermore, the placenta of the first trimester and that at term differ in their hormone profiles, extents of apoptosis, expression of several transcription factors, etc. This dramatic change in the phenotype of the human placenta can be considered to be the outcome of an intrinsically programmed pattern of differentiation, which may be referred to as the functional differentiation of the placenta. It may be hypothesized therefore, that this functional differentiation could be brought about by the differential expression of genes in the first trimester and the term placenta. The objectives of the present study were: 1. To gain an insight into this process of " functional differentiation” by investigating the differential expression of genes in the two developmentally distinct stages during gestation, viz. during the first trimester and at term. 2. To understand the functional relevance of the differentially expressed genes. A general introduction of the human placenta, describing the importance of differential expression in modulating placental function, is discussed in chapter 1. The functions of the human placenta along with a brief description of its development and differentiation are also briefly described. A Differential Display RT-PCR-based (DD RT-PCR) approach, using total RNA from the first-trimester and term placental villi, was employed to display the differentially expressed genes in the first trimester and the term placenta. The display so generated was used to identify a few differentially expressed cDNAs. This study was aimed at understanding the functional significance of the transcripts which were identified from the display, rather than just concentrate on documenting the differences in the gene expression patterns in the first trimester and the term placental tissue. A detailed description of the methodology adopted for performing DD-PCR using placental tissue, discussing the advantages and disadvantages of using differential display PCR, is described in chapter2. The use of DD-PCR for studying differential gene expression in the human placenta was validated by the finding that one of the cDNAs that was differentially expressed in the first trimester placental tissue, is a fragment of β-hCG cDNA. It is well documented that the differential expression of the β-subunit of hCG (human chorionic gondatrophin) during the first eight weeks of gestation is the rate limiting step in the synthesis and secretion of the functional hormone, which comprises the α and the β-subunits. Furthermore, the use of the model system viz., the first trimester and term placental tissue, was also validated for carrying out DD-PCR by ensuring that all placental samples used for DD analysis were free of endometrial contamination. A detailed description of optimization and validation of DD-PCR in human placental tissues is given in chapter 2. Cloning and sequencing of yet another cDNA from the first trimester differential display revealed that it is T-Plastin. T-Plastin is a member of a family of proteins that are involved in actin-bundling. Northern blot analysis and immunohistochemical studies using an antibody generated to a peptide corresponding to human T-Plastin, confirmed its differential expression and localization in the first trimester placenta. Considering the fact that several carcinomas show enhanced expression of T-Plastin, we tested the hypothesis that its differential expression is correlated with the proliferative potential of the first-trimester placenta It was observed that the first-trimester tissue expressed high levels of beta-actin as compared to the term placental tissue. This is in agreement with the up-regulation of beta-actin following mitogenic stimulation/proliferation and during neoplastic transformation or transformation-associated invasive behaviour of cells, two characteristic features shared by the early placenta with cancerous tissues. Based on our studies and available information in the literature, it is proposed that T-Plastin expression in the first trimester placenta is a growth-associated phenomenon which is partially responsible for the tumor-like phenotype of the first trimester tissue. Studies carried out with the partial T-Plastin cDNA clone that was isolated from the first trimester differential display, are presented in chapter 3. Sequencing of yet another cDNA clone identified from the term placental differential display, T-18 revealed that it had no homology to any known sequence in the nucleotide or est databases. The sequence corresponding to this clone was submitted to the GenBank and was assigned an accession number- AF089811. The differential expression of T-18 was confirmed by Northern blot analysis and RT-PCR analysis. Attempts were made to isolate the full-length cDNA corresponding to T-18 from a commercially available library from Clontech. However, repeated trials to identify the clone corresponding to T-18 did not yield any positive results. However, a genome database search revealed that T-18 was a portion of a large contig contained in chromosome 15. Analysis of the annotated gene sequences in and around the region in which T-18 is located in chromosome 15, revealed that there are very few ests reported in this contig and quite a few repeat sequences reported. Interestingly, it was observed that 6 kb downstream of the region in which T-18 is located, there was an est that had homology to a Bcl-2 precursor protein (an evolutionarily conserved, anti-apoptotic protein, capable of conferring protection against death-inducing signals) and the death adaptor protein, CRADD {Caspase and RIP adapter with death domain). Further updating of the ests in the database might probably be of help in the identification of the full-length cDNA corresponding to T-18 and confirm as to whether T-18 is a part of the gene/gene cluster that comprises the afore-mentioned est. An account of the identification and cloning of T-18 from the term placenta and the attempts to isolate the full-length cDNA clone corresponding to T-18 from a term placental cDNA library, is described in chapter 4. In the absence of any information on the identity of T-18, a study to understand the functional significance of T-18 expression was carried out. Since it was not possible to carry out studies pertaining to the temporal expression of T-18 throughout gestation on the human placenta for ethical reasons, alternate animal/organ models were employed to study T-18 expression. Rat placenta and rat Corpus Luteum (CL) were chosen as alternate models for studying T-18 expression as these two organs/tissues underwent dynamic changes in their function throughout pregnancy. For instance, it is well known that CL is the primary source of progesterone for maintaining pregnancy in the rat and that the progesterone secreting capacity of the luteal cells peak on day 16 of gestation and decline thereafter. Interestingly, a common feature among all the tissues that were chosen for investigating the regulation of T-18 expression, is the fact that they underwent apoptosis with increase in gestational age. The expression of T-18, in tissues exhibiting increased incidence of apoptosis suggested that T-18 maybe an apoptosis-associated gene. Using an explant culture model it was demonstrated that placental villi when cultured in vitro underwent spontaneous apoptosis and that the levels of T-18 message increased, under these conditions. Furthermore, this spontaneous induction of apoptosis in explant cultures could be blocked when villi were cultured in the presence of superoxide dismutase, a free radical scavenging enzyme. In addition, the expression of T-18 was shown to be modulated following treatment with SOD, or in response to oxidative stress. These studies clearly indicate a role for T-18 in placental apoptosis and moreover, implicate the usefulness of explant culture to examine the molecular mechanisms involved in placental apoptosis. Furthermore, the expression of the anti- and pro-apoptotic genes, bcl-x and bax respectively, were investigated, in an attempt to elucidate the signalling pathway(s) that led to the activation of an important downstream protease, caspase-3, in placental apoptosis. The present study revealed that induction of apoptosis in the placenta in vitro involved a bcl/bax independent, caspase-3 dependant pathway. The validation of an explant culture model for studying placental apoptosis and data pertaining to the role of T-18, bcl-x, bax and CPP32 in placental apoptosis, in response to oxidative stress, are presented in chapter 5. The last section titled general discussion summarizes the work carried out in this study and proposes a model for the apoptotic mechanism(s) that may be operating in placenta In conclusion, the present study has led to the identification of two developmentally-regulated factors, T-Plastin and T-18 in the first trimester and term placenta, respectively. The differential expression of these genes, in addition to several other molecular players, is proposed to be responsible for the overall functional differentiation of the placenta through the course of gestation.

Placenta is a transient association of the fetal and maternal tissues, that develops during pregnancy, in most viviparous animals. The evolution of placenta ensured the development of the fetus inside the womb of the mother, providing a protected environment for the development of the fetus, and preventing the loss of progeny due to unfavorable environmental conditions. Because it is strategically poised at the maternal and fetal interface, the placenta is ideally suited to carry out alimentary, respiratory and excretory functions for the developing fetus. In addition, it serves as an immunological barrier preventing the rejection of the fetal semi-allograft, by the maternal immune system. Furthermore, the placenta elaborates a variety of protein, polypeptide and steroid hormones. These include growth factors, growth factor receptors, neuropeptides, opioids, progesterone and estrogen, whose secretion is dependent on the gestational age of the placenta and its differentiation status. The human placenta, adapts itself remarkably to cater to the changing requirements of the developing fetus. For instance, during the first trimester of pregnancy, the placenta is an actively dividing, a highly invasive and a rapidly differentiating organ; while near term, it represents a fully differentiated and a non-invasive unit. Furthermore, the placenta of the first trimester and that at term differ in their hormone profiles, extents of apoptosis, expression of several transcription factors, etc. This dramatic change in the phenotype of the human placenta can be considered to be the outcome of an intrinsically programmed pattern of differentiation, which may be referred to as the functional differentiation of the placenta. It may be hypothesized therefore, that this functional differentiation could be brought about by the differential expression of genes in the first trimester and the term placenta. The objectives of the present study were: 1. To gain an insight into this process of " functional differentiation” by investigating the differential expression of genes in the two developmentally distinct stages during gestation, viz. during the first trimester and at term. 2. To understand the functional relevance of the differentially expressed genes. A general introduction of the human placenta, describing the importance of differential expression in modulating placental function, is discussed in chapter 1. The functions of the human placenta along with a brief description of its development and differentiation are also briefly described. A Differential Display RT-PCR-based (DD RT-PCR) approach, using total RNA from the first-trimester and term placental villi, was employed to display the differentially expressed genes in the first trimester and the term placenta. The display so generated was used to identify a few differentially expressed cDNAs. This study was aimed at understanding the functional significance of the transcripts which were identified from the display, rather than just concentrate on documenting the differences in the gene expression patterns in the first trimester and the term placental tissue. A detailed description of the methodology adopted for performing DD-PCR using placental tissue, discussing the advantages and disadvantages of using differential display PCR, is described in chapter2. The use of DD-PCR for studying differential gene expression in the human placenta was validated by the finding that one of the cDNAs that was differentially expressed in the first trimester placental tissue, is a fragment of β-hCG cDNA. It is well documented that the differential expression of the β-subunit of hCG (human chorionic gondatrophin) during the first eight weeks of gestation is the rate limiting step in the synthesis and secretion of the functional hormone, which comprises the α and the β-subunits. Furthermore, the use of the model system viz., the first trimester and term placental tissue, was also validated for carrying out DD-PCR by ensuring that all placental samples used for DD analysis were free of endometrial contamination. A detailed description of optimization and validation of DD-PCR in human placental tissues is given in chapter 2. Cloning and sequencing of yet another cDNA from the first trimester differential display revealed that it is T-Plastin. T-Plastin is a member of a family of proteins that are involved in actin-bundling. Northern blot analysis and immunohistochemical studies using an antibody generated to a peptide corresponding to human T-Plastin, confirmed its differential expression and localization in the first trimester placenta. Considering the fact that several carcinomas show enhanced expression of T-Plastin, we tested the hypothesis that its differential expression is correlated with the proliferative potential of the first-trimester placenta It was observed that the first-trimester tissue expressed high levels of beta-actin as compared to the term placental tissue. This is in agreement with the up-regulation of beta-actin following mitogenic stimulation/proliferation and during neoplastic transformation or transformation-associated invasive behaviour of cells, two characteristic features shared by the early placenta with cancerous tissues. Based on our studies and available information in the literature, it is proposed that T-Plastin expression in the first trimester placenta is a growth-associated phenomenon which is partially responsible for the tumor-like phenotype of the first trimester tissue. Studies carried out with the partial T-Plastin cDNA clone that was isolated from the first trimester differential display, are presented in chapter 3. Sequencing of yet another cDNA clone identified from the term placental differential display, T-18 revealed that it had no homology to any known sequence in the nucleotide or est databases. The sequence corresponding to this clone was submitted to the GenBank and was assigned an accession number- AF089811. The differential expression of T-18 was confirmed by Northern blot analysis and RT-PCR analysis. Attempts were made to isolate the full-length cDNA corresponding to T-18 from a commercially available library from Clontech. However, repeated trials to identify the clone corresponding to T-18 did not yield any positive results. However, a genome database search revealed that T-18 was a portion of a large contig contained in chromosome 15. Analysis of the annotated gene sequences in and around the region in which T-18 is located in chromosome 15, revealed that there are very few ests reported in this contig and quite a few repeat sequences reported. Interestingly, it was observed that 6 kb downstream of the region in which T-18 is located, there was an est that had homology to a Bcl-2 precursor protein (an evolutionarily conserved, anti-apoptotic protein, capable of conferring protection against death-inducing signals) and the death adaptor protein, CRADD {Caspase and RIP adapter with death domain). Further updating of the ests in the database might probably be of help in the identification of the full-length cDNA corresponding to T-18 and confirm as to whether T-18 is a part of the gene/gene cluster that comprises the afore-mentioned est. An account of the identification and cloning of T-18 from the term placenta and the attempts to isolate the full-length cDNA clone corresponding to T-18 from a term placental cDNA library, is described in chapter 4. In the absence of any information on the identity of T-18, a study to understand the functional significance of T-18 expression was carried out. Since it was not possible to carry out studies pertaining to the temporal expression of T-18 throughout gestation on the human placenta for ethical reasons, alternate animal/organ models were employed to study T-18 expression. Rat placenta and rat Corpus Luteum (CL) were chosen as alternate models for studying T-18 expression as these two organs/tissues underwent dynamic changes in their function throughout pregnancy. For instance, it is well known that CL is the primary source of progesterone for maintaining pregnancy in the rat and that the progesterone secreting capacity of the luteal cells peak on day 16 of gestation and decline thereafter. Interestingly, a common feature among all the tissues that were chosen for investigating the regulation of T-18 expression, is the fact that they underwent apoptosis with increase in gestational age. The expression of T-18, in tissues exhibiting increased incidence of apoptosis suggested that T-18 maybe an apoptosis-associated gene. Using an explant culture model it was demonstrated that placental villi when cultured in vitro underwent spontaneous apoptosis and that the levels of T-18 message increased, under these conditions. Furthermore, this spontaneous induction of apoptosis in explant cultures could be blocked when villi were cultured in the presence of superoxide dismutase, a free radical scavenging enzyme. In addition, the expression of T-18 was shown to be modulated following treatment with SOD, or in response to oxidative stress. These studies clearly indicate a role for T-18 in placental apoptosis and moreover, implicate the usefulness of explant culture to examine the molecular mechanisms involved in placental apoptosis. Furthermore, the expression of the anti- and pro-apoptotic genes, bcl-x and bax respectively, were investigated, in an attempt to elucidate the signalling pathway(s) that led to the activation of an important downstream protease, caspase-3, in placental apoptosis. The present study revealed that induction of apoptosis in the placenta in vitro involved a bcl/bax independent, caspase-3 dependant pathway. The validation of an explant culture model for studying placental apoptosis and data pertaining to the role of T-18, bcl-x, bax and CPP32 in placental apoptosis, in response to oxidative stress, are presented in chapter 5. The last section titled general discussion summarizes the work carried out in this study and proposes a model for the apoptotic mechanism(s) that may be operating in placenta In conclusion, the present study has led to the identification of two developmentally-regulated factors, T-Plastin and T-18 in the first trimester and term placenta, respectively. The differential expression of these genes, in addition to several other molecular players, is proposed to be responsible for the overall functional differentiation of the placenta through the course of gestation.

The placenta is a unique example of a complex organ that has evolved independently more than 115 times in amniotes (birds, reptiles, and mammals). Placentae exchange materials including respiratory gasses, nutrients, and hormones, between the mother and embryo. I aimed to identify the physiological and ecological factors that contribute to the evolution of placentation in vertebrates, focusing on the genetic mechanisms underpinning the evolution of placental functions, and the role of parent-offspring conflict in the evolution of placental traits. Given placentation has evolved independently many times, I assessed whether convergent evolution of placental functions is underpinned by the same genes in mammals and reptiles. I used high throughput sequencing to identify the gene expression patterns that facilitate placental functions in the placentotrophic southern grass skink (Pseudemoia entrecasteauxii).I show that hormone production occurs in the embryonic membranes of amniotes, and the production of growth factors by embryonic placental tissues is an exaptation of ancestrally expressed genes. I show that embryonic hormone production is a mechanism by which embryos can manipulate the function of the placenta, and regulate placental nutrient transport. By investigating the physiology and genetic underpinning of placental functions in reptiles, I provide fundamental data for understanding the evolution of viviparity and placentation in a lineage independent of viviparous mammals. I identify key similarities and differences between reptile and mammal pregnancy that outline the limits to which comparisons between the two lineages can be made. Finally, I show that parent offspring conflict is unlikely to play a role in the evolution of nutrient transport mechanisms in the placenta, but may be a driving force in the shift from lecithotrophic (a reliance on egg yolk for embryonic development) to placentotrophic nutrient provisioning through pregnancy.

Introduction: Traumatic injuries in pregnant women are the leading cause of non-obstetric death and affect 6% to 8% of all pregnancies. Therefore, it is imperative to maintain updated guidelines to construct a framework for the optimal management strategies for traumatic injuries in pregnant women, considering the perspectives of obstetrics/gynecology, emergency medicine, and orthopedics. Methods: To conduct this study, research was done via a database search through the Rowan-Virtua School of Osteopathic Medicine’s research library. PubMed was the sole database used to review 8 peer-reviewed sources. Articles that were published within the last 10 years were chosen. Results: Every woman with significant traumatic injuries must have pregnancy ruled out given its unique physiologic characteristics. First responders gather history surrounding fetal movement, contractions, and vaginal bleeding. Stabilization includes fetal monitoring, fluid resuscitation, blood transfusions, and maternal repositioning. Laboratory studies and diagnostic imaging (ultrasound) do not harm the mother or baby and reflect fetal status. Sometimes, emergency cesarean delivery (≤ 5 minutes of arrest) is indicated. There are some reports of fetal survival and maternal benefit beyond 15 minutes of arrest. Domestic violence is the most common trauma mechanism for pregnant women and triggers several obstetric complications (fetal loss, pre-term delivery, and placental abruption). Conclusion: Adverse outcomes of pregnancy happen more frequently following trauma. Non-emergent trauma may be managed conservatively, delaying treatment until after delivery. Surgical positioning, medication administration, and diagnostic imaging determine the best outcomes for the mother and child.

The present workconducted to evaluate the preventive role of folic acid in decreasing harmful effect on some phisiological changes & malformation in pregnant mice and their embryos. In this research we used Depakine (anti convulsant) at concentration of (300,500,600). In the present work, administration of Depakine (anti-convolsant) at the concentration of (300,500,600) mg/kg and folic acid 5 mg/kg to pregnant mice from the 1st till the 18th day of gestation. 30 pregnant mice were used and 2 experiments were performed.each experimental have 3 groups with 5 pregnant mice in each group. In the first experiment.the first group involved 5 pregnant mice were administered oral doses of distilled water and served as control, second group involved 5 pregnant mice treated with 500 mg/Kg Depakine,third group involved these mice treated with 300mg/Kg of body .The 2nd experiment involved 3 groups: The first was administered oral doses of folic acid at 5 mg from the 1 st to the 18th day of gestation. The other two groups were treated by the same vitamine and being left for an one hour (to be obsorbed) and then administered by oral doses of Depakine equivalent to (300 and 500) mg/kg respectively from 1st to the 18th day of gestation ,(600mg group were repeated 2 times and there was death among pregnant mice). The statistical analysis revealed a significant decrease in the average of length, weight and number of embryos if compared to control, pregnant mice organs (liver,heart,kidney,lung,brain,spleen,reproductive system&placenta),all showed significant decrease when compared to control. The dosage by Depakine leads to multiple physiologic malformations mostly: head caP atrophy,tissues invaginations,different sites haemorrhage especially bloody spot at the mid – dorsum,hooked tailes. We concluded from what previously mentioned that the admission of Depakine leaded to multiple organs malformations, whereas, folic acid has a preventive but not treating role in decreasing such effects. Also, some malformations were noted at the groups dosed by Depakine + vitamin together

Central problems in sheep and dairy cattle production are reproductive failure due to embryonic/fetal mortality and low birth weights, especially in prolific breeds, and reduced milk yields which adversely affect neonatal survival and economy of production. The sheep placenta expresses lactogenic (ovine placental lactogen, oPL) and somatogenic (ovine placental growth hormone, oGH) hormones. Our research has focused on the biological roles of oPL and oGH in function of the uterine endometrium during gestation and the mammary gland during pregnancy and lactation. Major conclusions were that: ( 1 ) immunization of prepubertal ewes against oPL resulted in increased birth weights of their lambs and their milk production during lactation; (2) neither oPL nor oGH had an antiluteolytic effect on uterine endometrium to affect lifespan of the corpus luteum; (3) only sequential exposure of the progesterone stimulated uterus to oIFNt and oPL or oGH increased endometrial gland proliferation and secretory protein gene expression; (4) oPL signals through a homodimer of ovine prolactin receptor (PRL-R) and heterodimer of oPRL-R and growth hormone receptor (GH-R); (5) exogenous recombinant oPL and oGH stimulated mammogenesis and milk yield during lactation; and (6) mutation of oPL and oGH was used to define specific biological effects and a rational basis for design of a specific receptor agonists or antagonists. This project was very productive in elucidating basic biological effects of oPL and oGH on intracellular signal transduction pathways, uterine development and secretory function, as well as mammogenesis and lactogenesis. We determined that immunization of prepubertal ewes against roPL increased birth weights of their lambs, especially those born as twins and triplets, as well as enhanced lactational performance. These studies significantly extended our knowledge of uterine and fetal-placental physiology and provided a foundation for new strategies to enhance reproductive and lactation efficiency. Based on these results, the major achievements were: 1) creation of a practical and cost effective management tool for producers to increase reproductive performance, neonatal survival, and milk yield of ewes in commercial flocks; and 2) define, for the first time, biological effects of oPL on endometrial functions and gene expression by uterine gland epithelium.