Phagocytosis as a potential mechanism for microbial defense of mouse placental trophoblast cells

Trophoblast giant cells are active phagocytes during implantation and post-implantation. Phagocytosis decreases during placental maturation as the phagocytic function of nutrition is gradually replaced by the direct uptake of nutrients by the labyrinth zone trophoblast. We hypothesize that, after placental maturation, trophoblast cells maintain phagocytic functions for purposes other than nutrition. This study employs histological techniques to examine the ability of trophoblast cells to phagocytose microorganisms (yeast or bacteria)–in vivoin females receiving thioglycolate to activate macrophages andin vitroin the presence of phagocytic promoters such as interferon-γ and complement component C3. Placental trophoblast cells from the second half of gestation show basal phagocytosis that can be dramatically up-regulated by these promoters when microorganisms are inoculated into pregnant animals or introduced into culture systems. Stimulated trophoblast cells phagocytosed organisms more rapidly and in greater numbers than non-stimulated trophoblast exposed to the same numbers of organisms. Taken together, our results indicate that trophoblast cells do not lose their ability to phagocytose during the placentation process, which may imply that trophoblast cells participate in embryonic and fetal innate immune defense through elimination of microorganisms present at the maternal–fetal interface.

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The mechanism of mouse egg-cylinder morphogenesis in vitro

Development ◽

10.1242/dev.61.1.277 ◽

1981 ◽

Vol 61 (1) ◽

pp. 277-287

Author(s):

A. J. Copp

Keyword(s):

Giant Cell ◽

Cell Formation ◽

Cell Movement ◽

Giant Cells ◽

Cell Number ◽

Dependent Change ◽

Morphogenesis In Vitro ◽

Trophoblast Giant Cells

The number of trophoblast giant cells in outgrowths of mouse blastocysts was determined before, during and after egg-cylinder formation in vitro. Giant-cell numbers rose initially but reached a plateau 12 h before the egg cylinder appeared. A secondary increase began 24 h after egg-cylinder formation. Blastocysts whose mural trophectoderm cells were removed before or shortly after attachment in vitro formed egg cylinders at the same time as intact blastocysts but their trophoblast outgrowths contained fewer giant cells at this time. The results support the idea that egg-cylinder formation in vitro is accompanied by a redirection of the polar to mural trophectoderm cell movement which characterizes blastocysts before implantation. The resumption of giant-cell number increase in trophoblast outgrowths after egg-cylinder formation may correspond to secondary giant-cell formation in vivo. It is suggested that a time-dependent change in the strength of trophoblast cell adhesion to the substratum occurs after blastocyst attachment in vitro which restricts the further entry of polar cells into the outgrowth and therefore results in egg-cylinder formation.

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In vivo and in vitro development of mouse embryos homozygous for the embryonic lethal velvet coat (Ve) mutation

Development ◽

10.1242/dev.66.1.43 ◽

1981 ◽

Vol 66 (1) ◽

pp. 43-55

Author(s):

J. Rossant ◽

K. M. Vijh

Keyword(s):

Inner Cell Mass ◽

Cell Mass ◽

Giant Cells ◽

Blastocyst Stage ◽

Parietal Endoderm ◽

Trophoblast Giant Cells ◽

Vitro Development ◽

Ectoplacental Cone

Embryos homozygous for the velvet coat mutation, Ve/Ve, were recognized at 6·5 days post coitum by the reduced size of the ectodermal portions of the egg cylinder and the loose, columnar nature of the overlying endoderm. Later in development ectoderm tissues were sometimes entirely absent. Abnormalities appeared in the ectoplacental cone at 8·5 days but trophoblast giant cells and parietal endoderm appeared unaffected. Homozygotes could not be unequivocally identified at 5·5 days nor at the blastocyst stage but were recognized in blastocyst outgrowths by poor development of the inner cell mass derivatives, It has previously been suggested that Ve may exert its action at the blastocyst stage by reducing the size of the inner cell mass, but no evidence for such a reduction was found. Most of the observations on Ve/Ve homozygotes are, however, consistent with the hypothesis that Ve exerts its action primarily on later primitive ectoderm development.

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Response of preimplantation rat blastocysts in vitro to extracellular uterine luminal components, serum and hormones

Journal of Cell Science ◽

10.1242/jcs.25.1.265 ◽

1977 ◽

Vol 25 (1) ◽

pp. 265-277

Author(s):

M.A. Surani

Keyword(s):

Calf Serum ◽

Giant Cells ◽

Biologically Active ◽

Foetal Calf Serum ◽

Active Components ◽

Rat Serum ◽

Pregnant Females ◽

Trophoblast Giant Cells

The influence of extracellular environmental factors on preimplantation rat blastocysts was tested by determining the number of embryos which escaped from their zonae pellucidae, followed by attachment and outgrowth of trophoblast giant cells, after 72 h in culture Uterine luminal ocmponents from individual females, or hormones, were included in Dulbecco's medium which contained 4 mg/ml bovine serum albumin. In about 20% of cases, uterine fluids were embryotonic. However, uterine fluids from day-5 pregnant females, the day of implantation in the rat, were more potent in these tests than uterine fluids obtained from ovariectomized females treated with progesterone alone. The potency of a mixture of the 2 fluids was also high. Uterine fluids obtained at 14 h after an injection of oestradiol and progesterone to the ovariectomized females, were also effective in these tests. Rat serum and foetal calf serum were effective too, but steroids or insulin alone in the medium had no detectable influence on embryos. Serum or uterine luminal proteins appear to be essential for maintaining the viability of the blastocysts and for inducing the responses observed here. In the uterine fluids, some proteins released into the lumen after treatment of females with oestradiol and progesterone appear to be the biologically active components. Differences in the responses of blastocysts in vitro are compared with those in vivo.

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Localization of paternal H-2K antigens on murine trophoblast cells in vivo.

Journal of Experimental Medicine ◽

10.1084/jem.155.6.1679 ◽

1982 ◽

Vol 155 (6) ◽

pp. 1679-1689 ◽

Cited By ~ 52

Author(s):

S Chatterjee-Hasrouni ◽

P K Lala

Keyword(s):

Uterine Artery ◽

Giant Cells ◽

Capillary Endothelium ◽

Trophoblast Cells ◽

In Vivo Expression ◽

Trophoblast Giant Cells ◽

Negative Controls

We have previously shown the presence of H-2K and D antigens of both parental haplotypes on dispersed murine trophoblast cells. The question still remained whether such antigens are sequestered away from the sinusoidal face of these cells making them inert as allografts. The in vivo expression of H-2 antigens on these cells was therefore examined radioautographically after perfusion of 125I-labeled monoclonal and anti-H-2Kk (anti-paternal) antibody directly into individual placental branches of the uterine artery suppling 15-d-old (C57BL/6J female) X CBA/J male) placentae. Syngeneic C57BL/6J placentae served as negative controls. A radioautographic examination of 0.5-micrometer-thick sections revealed specific labeling of labyrinthine trophoblasts lining the sinusoids of allogeneic placentae. Most of this labeling was localized to the sinusoidal face of the cells as opposed to a weak labeling of the intracellular aspect. Spongiotrophoblasts and trophoblast giant cells did not label, but specific labeling of fetal capillary endothelium and some macrophages was also noted.

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Trophoblast differentiation in vitro: establishment and characterisation of a serum-free culture model for murine secondary trophoblast giant cells

Reproduction ◽

10.1530/rep.1.00149 ◽

2004 ◽

Vol 128 (1) ◽

pp. 53-71 ◽

Cited By ~ 10

Author(s):

A H K El-Hashash ◽

S J Kimber

Keyword(s):

Giant Cells ◽

Placental Lactogen ◽

Blood Group Antigens ◽

Trophoblast Cells ◽

Trophoblast Differentiation ◽

Serum Free ◽

Activator Protein ◽

Trophoblast Giant Cells ◽

Giant Nuclei

Differentiation of trophoblast giant cells is an early event during the process of murine embryo implantation. However, differentiation of secondary trophoblast giant cells in the rodent is still only partially understood, probably because of the lack of suitablein vitromodels and cell markers. In order to advance our understanding of trophoblast differentiation, suitablein vitromodels and markers are required to study their development. The objectives of this study were to establish and characterise a serum-freein vitromodel for murine secondary trophoblast cells. Secondary trophoblast giant cells growingin vitroand paraffin sections of day 8.5 postcoitum mouse embryos were processed for immunostaining to establish the expression of potential markers using antibodies to blood group antigens, E-cadherin, α7integrins and activator protein-γ, as well as placental lactogen-II. Within 3 days in serum-free culture, ectoplacental cone-derived secondary trophoblast cells underwent simultaneous induction of both morphological and functional differentiation. Secondary trophoblasts grewin vitroas a monolayer of cells with giant nuclei and expressed B and Le-b/Le-y blood group antigens, α7integrins and placental lactogen-II, as well as activator protein-γ. Transcripts for activator protein-γ and placental lactogen-II were detected in cultures by RT-PCR and for placental lactogen-II byin situhybridisation. At later time-points apoptosis increased. A fibronectin substrate significantly increased secondary trophoblast cell numbers and surface area of outgrowth. The increase in cells with giant nuclei coincided with induction of placental lactogen-II expression. A relationship was found between the nuclear area of secondary trophoblast cells and expression of placental lactogen-II.

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DYNAMIC REGULATION OF AP-1 TRANSCRIPTIONAL COMPLEXES DIRECTS TROPHOBLAST DIFFERENTIATION

Molecular and Cellular Biology ◽

10.1128/mcb.00118-15 ◽

2015 ◽

pp. MCB.00118-15 ◽

Cited By ~ 7

Author(s):

Kaiyu Kubota ◽

Lindsey N. Kent ◽

M.A Karim Rumi ◽

Katherine F. Roby ◽

Michael J. Soares

Keyword(s):

Transcriptome Profiling ◽

Giant Cells ◽

Trophoblast Cells ◽

Placental Development ◽

Dynamic Regulation ◽

In Vivo Experiments ◽

Lineage Differentiation ◽

Transcriptional Complexes ◽

Trophoblast Giant Cells

Placentation is a process that establishes the maternal-fetal interface and is required for successful pregnancy. The epithelial component of the placenta consists of trophoblast cells, which possess the capacity for multi-lineage differentiation and are responsible for placental-specific functions. FOS like antigen 1 (FOSL1), a component of AP-1 transcription factor complexes, contributes to the regulation of placental development. FOSL1 expression is restricted to trophoblast giant cells and invasive trophoblast cells. In the present study, we characterized the FOSL1 regulatory pathway in rat trophoblast cells. Transcriptome profiling in control and FOSL1 knockdown cells identified FOSL1 dependent gene sets linked to endocrine and invasive functions. FOSL1 was shown to occupy AP-1 binding sites within these gene loci, determined by chromatin immunoprecipitation (ChIP). Complementary in vivo experiments using trophoblast specific-lentiviral delivery of FOSL1 shRNAs provided an in vivo validation of FOSL1 targets. FOSL1 actions require a dimerization partner. Co-immunoprecipitation, co-immunolocalization, and ChIP analyses showed that FOSL1 interacts with JUNB and to a lesser extent JUN in differentiating trophoblast cells. Knockdown of FOSL1 and JUNB expression inhibited both endocrine and invasive properties of trophoblast cells. In summary, FOSL1 recruits JUNB to form AP-1 transcriptional complexes that specifically regulate the endocrine and invasive trophoblast phenotype.

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Patterns of lactic dehydrogenase isozymes in mouse embryos over the implantation period in vivo and in vitro

Development ◽

10.1242/dev.36.3.653 ◽

1976 ◽

Vol 36 (3) ◽

pp. 653-662

Author(s):

Marilyn Monk ◽

John Ansell

Keyword(s):

Specific Activity ◽

Inner Cell Mass ◽

Cell Mass ◽

Lactic Dehydrogenase ◽

Giant Cells ◽

Preimplantation Embryos ◽

Blastocyst Implantation ◽

Trophoblast Giant Cells

Following blastocyst implantation, or outgrowth in vitro, the LDH isozyme pattern changes from that of the maternally inherited B subunit isozyme form (LDH-1) to a pattern dominated by A subunits (Auerbach & Brinster, 1967, 1968). In preimplantation embryos we have also observed additional isozyme bands, as yet unidentified. An analysis of the pattern of newly synthesized LDH isozymes and specific activity of LDH in different regions of early post implantation embryos suggests that there is a sequential activation of A and B subunits, and that activity first appears in ICM- (inner cell mass) derived tissues and then in trophoblast-derived tissues. In vitro, in the absence of ICM cells, the transition of LDHisozyme pattern does not occur in outgrowing trophoblast giant cells. This suggests a possible inductive interaction between ICM and trophoblast.

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