Attachment of human placental‐type alkaline phosphatase via phosphatidylinositol to syncytiotrophoblast and tumour cell plasma membranes

Webb, Paul D.; Todd, J A

doi:10.1111/j.1432-1033.1988.tb13938.x

Cited by 26 publications

(8 citation statements)

References 47 publications

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“…Treatment with PIPLC released H3 15-precipitable material into the supernatant, whilst bromelain released both H3 15-and W6/32-precipitable material. These results are consistent with previous reports, where the action of B.cereus phospholipase C in releasing PLAP from the choriocarcinoma membranes has been shown to be due to a PIPLC contaminant in the preparation (Webb and Todd, 1988). Although molecules of 72 kDa were identified in 5T4 immunoprecipitates from treated cell lysates, no labelled molecules were precipitated with MAb 5T4 from supernatants generated from bromelain or PIPLC-treated cells.…”

Section: Enzymatic Digestionsupporting

confidence: 95%

Isolation and characterization of 5T4, a tumour‐associated antigen

Hole¹,

Stern²

1990

Intl Journal of Cancer

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The monoclonal antibody (MAb) 5T4 defines a human trophoblast antigen marker with a restricted pattern of expression in normal adult tissues but this antigen is expressed on a variety of carcinomas. The purification of 5T4 antigenic molecules is described from term syncytiotrophoblast by a combination of lectin- and immunoaffinity chromatography and gel filtration giving up to 10,000-fold purification with 70% yield. The antigen is carried by non-associated glycoprotein molecules with an apparent molecular weight of 72 kDa on SDS-PAGE and a neutral pI. Removal of N-linked sugars by N-glycanase reveals a core protein of 42 kDa. Treatment with enzymes that cleave O-linked sugars does not substantially alter the molecular size. The native 5T4 molecules are very resistant to proteolysis until the N-linked sugars are removed or the glycoprotein is denatured and reduced. Glycopeptides generated by these approaches will be suitable for amino acid sequencing.

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Section: Enzymatic Digestionsupporting

confidence: 95%

Isolation and characterization of 5T4, a tumour‐associated antigen

Hole¹,

Stern²

1990

Intl Journal of Cancer

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“…The expression of hCG was shown to be required for spontaneous or EGF-stimulated differentiation (measured by hCG expression) of CTs (32). PLAP expression occurs on the brush border of differentiated trophoblasts (35), although whether this is linked to hCG production or some other aspect of the differentiation pathway is unknown. The appearance of ‫%03ف‬ of the nuclei in multinucleated units after 5 days (without the addition of EGF) was unaffected by S1P.…”

Section: Discussionmentioning

confidence: 99%

Sphingosine-1-phosphate inhibition of placental trophoblast differentiation through a Gi-coupled receptor response

Johnstone

Chan

Sibley

et al. 2005

Journal of Lipid Research

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The failure of placental trophoblasts to differentiate properly is thought to play an important role in the cause of pregnancy disorders such as preeclampsia. We looked at the effects of the bioactive lipid sphingosine-1-phosphate (S1P) on the differentiation of primary human cytotrophoblasts (CTs) into syncytiotrophoblasts (STs) in culture. We found that S1P inhibited CT differentiation measured by human chorionic gonadotropin (hCG) secretion and the expression of placental alkaline phosphatase but had no effect on their fusion into multinucleated syncytialized cells. G-protein-linked S1P receptors 1, 2, and 3 were found in CTs by reverse transcriptase-polymerase chain reaction, and receptor 1 was found by Western blot analysis. Disruption of G i signaling with pertussis toxin reversed the inhibitory effects of S1P. S1P reduced intracellular cAMP, and the addition of 8-bromo-cAMP reversed S1P inhibition of hCG secretion. Therefore, we suggest that S1P inhibits the differentiation of CTs into STs through G i -coupled S1P receptor interaction(s), leading to the inhibition of adenylate cyclase and reduced production of intracellular cAMP. This is the first reported effect of S1P on placental trophoblast function.

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“…Other proteins that are often used as markers for syncytiotrophoblast are human placental lactogen (hPL; CSH1) (Gaspard et al 1980, Pidoux et al 2007) and human placental alkaline phosphatase (ALPP; Webb & Todd 1988, Guilbert et al 2002. Regarding CGB, former studies have already shown that BeWo cell fusion is not necessarily linked to CGB mRNA expression (Lin et al 1999).…”

Section: Introductionmentioning

confidence: 99%

The choriocarcinoma cell line BeWo: syncytial fusion and expression of syncytium-specific proteins

Orendi¹,

Gauster²,

Moser³

et al. 2010

Reproduction

162

151

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Fusion of the trophoblast-derived choriocarcinoma cell line BeWo can be triggered by forskolin. BeWo cells are regularly used as a cell culture model to mimic in vivo syncytialisation of placental villous trophoblast. The b subunit of human chorionic gonadotropin (CGB), placental alkaline phosphatase as well as placental protein 13 (PP13, LGALS13) are exclusively expressed in the syncytiotrophoblast of the human placenta, and CGB is commonly used as a marker of syncytial differentiation. Here we tested the hypothesis that syncytial fusion precedes CGB and LGALS13 expression in trophoblast-derived BeWo cells. BeWo cells were cultured for 48 h in the presence or absence of forskolin and varying concentrations of H-89, a protein kinase A inhibitor that interferes with the forskolin-mediated pathway of syncytial fusion. LGALS13 and CGB expression were quantified by DELFIA and real-time PCR. Cell fusion was determined by morphological analysis and cell counting after immunofluorescence staining. In forskolin-stimulated BeWo cells that were hindered to fuse by treatment with H-89, levels of CGB protein expression were not altered, while LGALS13 protein and mRNA expression decreased significantly to control levels without forskolin. The LGALS13 protein expression data coincided with a significant decrease in syncytial fusion, while CGB protein expression was unaffected by rates of cell fusion and proliferation. We postulate that CGB protein expression is not necessarily linked to syncytial fusion, and thus CGB should be used with great caution as a marker of BeWo cell fusion.

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Attachment of human placental‐type alkaline phosphatase via phosphatidylinositol to syncytiotrophoblast and tumour cell plasma membranes

Cited by 26 publications

References 47 publications

Isolation and characterization of 5T4, a tumour‐associated antigen

Isolation and characterization of 5T4, a tumour‐associated antigen

Sphingosine-1-phosphate inhibition of placental trophoblast differentiation through a Gi-coupled receptor response

The choriocarcinoma cell line BeWo: syncytial fusion and expression of syncytium-specific proteins

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