scholarly journals Transcriptional Analysis by Nascent RNA FISH of In Vivo Trophoblast Giant Cells or In Vitro Short-term Cultures of Ectoplacental Cone Explants

Author(s):  
Catherine Corbel ◽  
Edith Heard
Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 43-55
Author(s):  
J. Rossant ◽  
K. M. Vijh

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.


Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 277-287
Author(s):  
A. J. Copp

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.


1977 ◽  
Vol 25 (1) ◽  
pp. 265-277
Author(s):  
M.A. Surani

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.


Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 183-194
Author(s):  
J. Rossant ◽  
L. Ofer

Extra-embryonic ectoderm isolated from the mouse embryo as late as 8½ days post coitum can form cells with the morphological characteristics of trophoblast giant cells both in ectopic sites and in vitro. This similarity to the properties of ectoplacental cone tissue provides further support for the postulated common origin of both tissues from the trophectoderm of the blastocyst.


Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 653-662
Author(s):  
Marilyn Monk ◽  
John Ansell

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.


Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 207-218 ◽  
Author(s):  
A Amarante-Paffaro ◽  
G S Queiroz ◽  
S T Corrêa ◽  
B Spira ◽  
E Bevilacqua

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.


Author(s):  
Daniel L. Villeneuve ◽  
Brett R. Blackwell ◽  
Jenna E. Cavallin ◽  
Wan‐Yun Cheng ◽  
David J. Feifarek ◽  
...  

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Leilei Lin ◽  
Yu Wang ◽  
Sicheng Bian ◽  
Lili Sun ◽  
Zhibo Guo ◽  
...  

Abstract Background As a common haematological malignancy, acute myeloid leukaemia (AML), particularly with extramedullary infiltration (EMI), often results in a high mortality rate and poor prognosis. Circular RNAs (circRNAs) regulate biological and pathogenic processes, suggesting a potential role in AML. We have previously described the overall alterations in circRNAs and their regulatory networks between patients with AML presenting with and without EMI. This study aims to find new prognostic and therapeutic targets potentially associated with AML. Methods qRT-PCR was performed on samples from 40 patients with AML and 15 healthy controls. The possibility of using circPLXNB2 (circRNA derived from PLXNB2) as a diagnostic and prognostic biomarker for AML was analysed with multiple statistical methods. In vitro, the function of circPLXNB2 was studied by lentivirus transfection, CCK-8 assays, flow cytometry, and Transwell experiments. Western blotting and qRT-PCR were performed to detect the expression of related proteins and genes. The distribution of circPLXNB2 in cells was observed using RNA fluorescence in situ hybridization (RNA-FISH). We also investigated the role of circPLXNB2 by establishing AML xenograft models in NOD/SCID mice. Results By analysing the results of qRT-PCR detection of clinical samples, the expression of the circPLXNB2 and PLXNB2 mRNAs were significantly increased in patients with AML, more specifically in patients with AML presenting with EMI. High circPLXNB2 expression was associated with an obviously shorter overall survival and leukaemia-free survival of patients with AML. The circPLXNB2 expression was positively correlated with PLXNB2 mRNA expression, as evidenced by Pearson’s correlation analysis. RNA-FISH revealed that circPLXNB2 is mainly located in the nucleus. In vitro and in vivo, circPLXNB2 promoted cell proliferation and migration and inhibited apoptosis. Notably, circPLXNB2 also increased the expression of PLXNB2, BCL2 and cyclin D1, and reduced the expression of BAX. Conclusion In summary, we validated the high expression of circPLXNB2 and PLXNB2 in patients with AML. Elevated circPLXNB2 levels were associated with poor clinical outcomes in patients with AML. Importantly, circPLXNB2 accelerated tumour growth and progression, possibly by regulating PLXNB2 expression. Our study highlights the potential of circPLXNB2 as a new prognostic predictor and therapeutic target for AML in the future.


2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.


1969 ◽  
Vol 49 (2) ◽  
pp. 135-141 ◽  
Author(s):  
L. P. Milligan ◽  
A. R. Robblee ◽  
J. C. Wood ◽  
W. C. Kay ◽  
S. K. Chakrabartty

The preparation of a polymer of urea and furfural containing 23.2% nitrogen is described. This product was converted by rumen microorganisms in vitro to ammonia at a rate approximately one-seventh that of conversion of urea to ammonia. Use of the polymer as a dietary supplement in a feeding trial with lambs improved nitrogen retention over that of unsupplemented controls by 3.45 g of nitrogen retained per day, while an isonitrogenous quantity of supplemental urea improved nitrogen retention by 0.51 g of nitrogen retained per day. The blood urea pattern, throughout the day, of lambs adapted to control, urea-supplemented and urea–furfural polymer-supplemented rations indicated a slow, prolonged production of ammonia from the latter supplement and very rapid, short-term degradation of urea in vivo.


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