scholarly journals Influence of Branching Patterns and Active Contractions of the Villous Tree on Fetal and Maternal Blood Circulations in the Human Placenta

2018 ◽  
Author(s):  
Yoko Kato
Keyword(s):  
Human Placenta ◽  
Maternal Blood ◽  
Branching Patterns

Placental amino acid transport

1995 ◽  
Vol 268 (6) ◽  
pp. C1321-C1331 ◽  
Author(s):  
A. J. Moe
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Human Placenta ◽  
Amino Acid Transport ◽  
Single Layer ◽  
Maternal Blood ◽  
Transport Systems ◽  
Amino Acid Transporters ◽  
Acid Transport ◽  
Principal Mechanism

Normal fetal growth and development depend on a continuous supply of amino acids from the mother to the fetus. The placenta is responsible for the transfer of amino acids between the two circulations. The human placenta is hemomonochorial, meaning that the maternal and fetal circulations are separated by a single layer of polarized epithelium called the syncytiotrophoblast, which is in direct contact with maternal blood. Transport proteins located in the microvillous and basal membranes of the syncytiotrophoblast are the principal mechanism for transfer from maternal blood to fetal blood. Knowledge of the function and regulation of syncytiotrophoblast amino acid transporters is of great importance in understanding the mechanism of placental transport and potentially improving fetal and newborn outcomes. The development of methods for the isolation of microvillous and basal membrane vesicles from human placenta over the past two decades has contributed greatly to this understanding. Now a primary cultured trophoblast model is available to study amino acid transport and regulation as the cells differentiate. The types of amino acid transporters and their distribution between the syncytiotrophoblast microvillous and basal membranes are somewhat unique compared with other polarized epithelia. These differences may reflect the unusual circumstance of this epithelium that is exposed to blood on both sides. The current state of knowledge as to the types of transport systems present in syncytiotrophoblast, their regulation, and the effects of maternal consumption of drugs on transport are discussed.

scholarly journals Pro-opiomelanocortin in human pregnancy: evolution of maternal plasma levels, concentrations in cord blood, amniotic fluid and at the feto-maternal interface

2000 ◽  
pp. 53-59 ◽  
Author(s):  
ML Raffin-Sanson ◽  
F Ferre ◽  
J Coste ◽  
C Oliver ◽  
D Cabrol ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Cord Blood ◽  
Pregnant Women ◽  
Human Placenta ◽  
Plasma Levels ◽  
Maternal Blood ◽  
Prospective Longitudinal Study ◽  
Gestation Time ◽  
Prospective Longitudinal ◽  
Very High

OBJECTIVE: The human placenta normally expresses the pro-opiomelanocortin (POMC) gene. The pattern and secretory kinetics of POMC and/or POMC-derived peptides by the placenta during gestation is still debated. We recently demonstrated that full length POMC was a normal product of the human placenta. The aim of our study was to establish its normal secretory kinetics and to explore its physiological relevance. DESIGN: In a prospective, longitudinal study, thirty normal pregnant women had monthly measurements of plasma POMC. In a cross-sectional study of 128 healthy pregnant women, plasma POMC and human chorionic gonadotrophin (hCG) were concomitantly measured to assess their correlation. Finally, POMC levels were assessed in venous and arterial cord blood samples, in amniotic fluid and in retroplacental blood. METHODS: Plasma POMC was measured by a specific IRMA in unextracted blood or biological fluid. RESULTS: Plasma POMC became detectable by the 8th week of pregnancy and reached its maximum at around the 20th week, remaining stable thereafter. The relationship between POMC and gestation time (weeks) best fitted with a third degree polynomia curve. A significant negative correlation (P=0.01) was observed between plasma levels of POMC and hCG after adjustment for gestation time to take into account the dependence of both hormones on this parameter. POMC was not secreted into the fetal circulation at term, but was present in very high levels in amniotic fluid. The highest levels of POMC were present in the retroplacental blood where the values were 35 times higher than in maternal blood; by comparison, corticotrophin releasing hormone and ACTH values in this compartment were twice or equal to those in the maternal blood. CONCLUSION: Placental POMC secretion increases during the first half of pregnancy and reaches a plateau from the 20th week to delivery. The inverse correlation between POMC and hCG plasma levels, and very high POMC levels at the feto-maternal interface suggest a physiological role for this precursor during pregnancy.

scholarly journals PERMEABILITY OF THE HUMAN PLACENTA TO ANTIBODIES

1940 ◽  
Vol 71 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Alexander S. Wiener ◽  
I. Jerome Silverman
Keyword(s):  
Cord Blood ◽  
Human Placenta ◽  
Maternal Blood

The ratio of the titers of various antibodies, namely, hemagglutinins and syphilitic reagin, in the maternal blood to that of the corresponding antibody in the cord blood was found to be relatively constant, falling somewhere between 8 and 16. This figure may be considered the "index of permeability" of human placenta to antibodies, or the coefficient of distribution of antibodies between maternal and cord blood. The possible application of these findings to the study of the placental permeability to sensitizing antibodies (or reagins) is discussed.

scholarly journals IV. On the placentation of the apes, with a comparison of the structure of their placenta with that of the human female

1878 ◽  
Vol 27 (185-189) ◽  
pp. 271-272
Keyword(s):  
Human Placenta ◽  
Detailed Comparison ◽  
Maternal Blood ◽  
Gravid Uterus ◽  
Human Female ◽  
John Hunter ◽  
Foetal Membranes ◽  
Comparative Structure ◽  
Arteries And Veins

The introductory chapter of this memoir consists of a summary of the observations of John Hunter, Rudolphi, Breschet, Owen, Huxley, Rolleston, Ercolani, and Kondratowicz, on the form and structure of the placenta in the apes. The author then gives a detailed description of his dissection of the gravid uterus and placenta of a Macacus cynomolgus well advanced in pregnancy. He then enters into a detailed comparison between the form and structure of the placenta in the ape and that of the human female, in the course of which he records a number of original observations on the structure of the human placenta. Attention is more especially drawn to the comparative structure of the decidua vera and serotina; to the prolongations of the decidua serotina into the interior of the placenta; to the arrangement, structure, and mode of origin of the intra-chorionic and sub-chorionic cells; to the arrangement of the arteries and veins of the placenta; to the intra-placental maternal blood-spaces; the form and structure of the chorionic villi: and to the relation of the maternal blood to the capillaries of the villi. The result of this comparison proves that the Macacus and human female closely correspond in the form of the uterus, and in the arrangement of the fœtal membranes, and that they both possess a discoid placenta, which in the Macacus is divided into two lobes, but is not so divided in the human placenta. In the arrangement and relative position of the constituent parts of the placenta they also correspond; and although some differences of detail in the characters of some of the structures occur, yet, in the main features of construction, makroscopic as well as microscopic, they have a close resemblance to each other.

scholarly journals Large-scale transcriptome-wide profiling of microRNAs in human placenta and maternal plasma at early to mid gestation

2020 ◽  
Author(s):  
Melanie D. Smith ◽  
Katherine Pillman ◽  
Tanja Jankovic-Karasoulos ◽  
Dale McAninch ◽  
Qianhui Wan ◽  
...  
Keyword(s):  
Gestational Age ◽  
Human Placenta ◽  
Large Scale ◽  
Chorionic Villus ◽  
Maternal Blood ◽  
Maternal Plasma ◽  
Placental Development ◽  
Early Gestation ◽  
Oxygen Environment ◽  
Mirna Clusters

AbstractBackgroundMicroRNAs (miRNAs) are increasingly seen as important regulators of placental development and opportunistic biomarker targets. Given the difficulty in obtaining samples from early gestation and subsequent paucity of the same, investigation of the role of miRNAs in early gestation human placenta has been limited. To address this, we generated miRNA profiles using 96 placentas from presumed normal pregnancies, across early gestation, in combination with matched profiles from maternal plasma. Placenta samples range from 6-23 weeks’ gestation, a time period that includes placenta from the early, relatively low but physiological (6-10 weeks’ gestation) oxygen environment, and later, physiologically normal oxygen environment (11-23 weeks’ gestation).ResultsWe identified 637 miRNAs with expression in 86 samples (after removing poor quality samples), showing a clear gestational age gradient from 6-23 weeks’ gestation. We identified 374 differentially expressed (DE) miRNAs between placentas from 6-10 weeks’ versus 11-23 weeks’ gestation. We see a clear gestational age group bias in miRNA clusters C19MC, C14MC, miR-17∼92 and paralogs, regions that also include many DE miRNAs. Proportional change in expression of placenta-specific miRNA clusters was reflected in maternal plasma.ConclusionThe presumed introduction of oxygenated maternal blood into the placenta (between ∼10-12 weeks’ gestation) changes the miRNA profile of the chorionic villus, particularly in placenta-specific miRNA clusters. Data presented here comprise a clinically important reference set for studying early placenta development and may underpin the generation of minimally invasive methods for monitoring placental health.

scholarly journals Term Human Placental Trophoblasts Express SARS-CoV-2 Entry Factors ACE2, TMPRSS2, and Furin

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Yingshi Ouyang ◽  
Tarique Bagalkot ◽  
Wendy Fitzgerald ◽  
Elena Sadovsky ◽  
Tianjiao Chu ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Human Placenta ◽  
Cell Types ◽  
Maternal Blood ◽  
Transmission Risk ◽  
Rna Seq ◽  
Angiotensin Converting Enzyme 2 ◽  
Real Time Quantitative Pcr ◽  
Different Cell Types

ABSTRACT The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a massive impact on human lives worldwide. While the airborne SARS-CoV-2 primarily affects the lungs, viremia is not uncommon. As placental trophoblasts are directly bathed in maternal blood, they are vulnerable to SARS-CoV-2. Intriguingly, the human fetus is largely spared from SARS-CoV-2 infection. We tested whether the human placenta expresses the main SARS-CoV-2 entry factors angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin and showed that ACE2 and TMPRSS2 are expressed in the trophoblast rather than in other placental villous cells. While furin is expressed in the main placental villous cell types, we surveyed, trophoblasts exhibit the highest expression. In line with the expression of these entry factors, we demonstrated that a SARS-CoV-2 pseudovirus could enter primary human trophoblasts. Mechanisms underlying placental defense against SARS-CoV-2 infection likely involve postentry processing, which may be germane for mitigating interventions against SARS-CoV-2. IMPORTANCE Pregnant women worldwide have been affected by COVID-19. As the virus is commonly spread to various organs via the bloodstream and because human placental trophoblasts are directly bathed in maternal blood, feto-placental infection by SARS-CoV-2 seems likely. However, despite the heightened risk to pregnant women, thus far the transmission risk of COVID-19 to the feto-placental unit seems extremely low. This has been recently attributed to a negligible expression of SARS-CoV-2 entry factors in the human placenta. We therefore sought to explore the expression of the entry factors ACE2 and TMPRSS2 in the different cell types of human placental villi. Using a combination of transcriptome sequencing (RNA-seq), real-time quantitative PCR (RT-qPCR), in situ hybridization, and immunofluorescence, we found that trophoblasts, but not the other main villous cell types, express ACE2 and TMPRSS2, with a broad expression of furin. Correspondingly, we also showed that primary human trophoblasts are permissive to entry of SARS-CoV-2 pseudovirus particles.

4. On the Maternal Sinus Vascular System of the Human Placenta

1872 ◽  
Vol 7 ◽  
pp. 760-762
Author(s):  
Turner
Keyword(s):  
Blood Vessels ◽  
Human Placenta ◽  
Vascular System ◽  
Maternal Blood ◽  
Uterine Wall ◽  
Full Time ◽  
Chorionic Villi

The author gave a brief sketch of the various theories which have been advanced by Velpeau, R. Lee, Braxton Hicks, the Hunters, Owen, Weber, J. Reid, J. Goodsir, Virchow, Kölliker, Van Der Kolk, Arthur Farre, and Ercolani regarding to the relations of the maternal blood-vessels to the placenta and chorionic villi. He then proceeded to state the results of his own observations on various specimens of placentæ, some of which had been separated at the full time, others prematurely, and on three specimens attached to the uterine wall.

scholarly journals Maternal Platelets of the Human Placenta: Friend or Foe?

2019 ◽  
Vol 20 (22) ◽  
pp. 5639 ◽  
Author(s):  
Moser ◽  
Guettler ◽  
Forstner ◽  
Gauster
Keyword(s):  
Platelet Count ◽  
Human Placenta ◽  
Disease Process ◽  
Maternal Blood ◽  
Sterile Inflammation ◽  
Inflammasome Activation ◽  
Third Trimester ◽  
Human Pregnancy ◽  
Important Regulator ◽  
Syncytiotrophoblast Layer

Human pregnancy relies on hemochorial placentation, including implantation of the blastocyst and deep invasion of fetal trophoblast cells into maternal uterine blood vessels, enabling direct contact of maternal blood with placental villi. Hemochorial placentation requires fast and reliable hemostasis to guarantee survival of the mother, but also for the neonates. During human pregnancy, maternal platelet count decreases gradually from first, to second, and third trimester. In addition to hemodilution, accelerated platelet sequestration and consumption in the placental circulation may contribute to a decline of platelet count throughout gestation. Local stasis, turbulences, or damage of the syncytiotrophoblast layer can activate maternal platelets within the placental intervillous space and result in formation of fibrin-type fibrinoid. Perivillous fibrinoid is a regular constituent of the normal placenta which is considered to be an important regulator of intervillous hemodynamics, as well as having a role in shaping the developing villous trees. However, exaggerated activation of platelets at the maternal-fetal interface can provoke inflammasome activation in the placental trophoblast, and enhance formation of circulating platelet-monocyte aggregates, resulting in sterile inflammation of the placenta and a systemic inflammatory response in the mother. Hence, the degree of activation determines whether maternal platelets are a friend or foe of the human placenta. Exaggerated activation of maternal platelets can either directly cause or propagate the disease process in placenta-associated pregnancy pathologies, such as preeclampsia.

scholarly journals Tissue Barriers of the Human Placenta to Infection with Toxoplasma gondii

2011 ◽  
Vol 80 (1) ◽  
pp. 418-428 ◽  
Author(s):  
Jennifer R. Robbins ◽  
Varvara B. Zeldovich ◽  
Anna Poukchanski ◽  
John C. Boothroyd ◽  
Anna I. Bakardjiev
Keyword(s):  
Toxoplasma Gondii ◽  
Human Placenta ◽  
Statistical Significance ◽  
Cell Types ◽  
First Trimester ◽  
Maternal Blood ◽  
Content Type ◽  
Obligate Intracellular ◽  
Significant Disease ◽  
Extravillous Trophoblasts

ABSTRACTToxoplasma gondiiis a ubiquitous, obligate intracellular parasite capable of crossing the placenta to cause spontaneous abortion, preterm labor, or significant disease in the surviving neonate. Exploration of the cellular and histological components of the placental barrier is in its infancy, and both how and whereT. gondiibreaches it are unknown. The human placenta presents two anatomical interfaces between maternal cells and fetal cells (trophoblasts): (i) the villous region where maternal blood bathes syncytialized trophoblasts for nutrient exchange and (ii) the maternal decidua, where mononuclear, extravillous trophoblasts anchor the villous region to the uterus. Using first-trimester human placental explants, we demonstrate that the latter site is significantly more vulnerable to infection, despite presenting a vastly smaller surface. This is consistent with past findings concerning two vertically transmitted viruses and one bacterium. We further explore whether three genetically distinctT. gondiitypes (I, II, and III) are capable of preferential placental infection and survival in this model. We find no difference in these strains' ability to infect placental explants; however, slightly slower growth is evident in type II (Prugniaud [Pru]) parasites relative to other cell types, although this did not quite achieve statistical significance.

Detection of benzo[a]pyrene-DNA adducts in human placenta and umbilical cord blood

1997 ◽  
Vol 16 (12) ◽  
pp. 716-721 ◽  
Author(s):  
JP Arnould ◽  
P. Verhoest ◽  
V. Bach ◽  
JP Libert ◽  
J. Belegaud
Keyword(s):  
Cord Blood ◽  
Umbilical Cord ◽  
Dna Adducts ◽  
Umbilical Cord Blood ◽  
Human Placenta ◽  
Tobacco Consumption ◽  
Maternal Blood ◽  
Favourable Effect ◽  
Foetal Development ◽  
Polycyclic Aromatic

Placenta constitutes a vital organ of exchange between mother and foetus. In addition to this favourable effect for foetal development, placenta indirectly may allow trans fer of several maternal blood xenobiotics. Human placenta and umbilical cord blood are interesting models for investigating maternal environment and the metabolism, the bioactivation and the transfer of carcinogens such as polycyclic aromatic hydrocarbons. We used them to assess the effect of a woman's smoking on the foetus. Few studies cover this subject. In pregnant women who have continued to smoke, benzo[a]pyrene compound of cigar ette smoke is metabolically activated to diol-epoxide derivative: benzo[a]pyrene-trans-7,8-dihydrodiol-9,10- epoxide, ultimate carcinogen (BPDE-I). This derivative is covalently fixed on DNA and gives BPDE-I-DNA adducts. By a competitive immunoassay technique, we determined BDPE-I-DNA adducts in 20 samples of placenta and umbilical cord blood from women who smoked (n=15) and who did not (n=10). Tobacco consumption was checked by urinary cotinine determination. In the group of smokers levels of adducts were found in 13 specimens of placenta (from 10 to 60 finol/50 μg of DNA) and 12 umbilical cord blood (from 10 to 22.15 fmol/50 μg of DNA) samples. These results indicate that a mother's tobacco consumption is linked to the accumulation of BPDE-I-DNA adducts in the placenta, which are seen in smaller quantities in the umbilical cord blood, probably because of the metabolic capacity of the placenta and the transfer of B[a]P from the mother to the foetus.

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