Disease relevance of Amnion

• A representative clone (T71-17SA2) which was used to assess selected cellular and host factors relevant to the metastatic process produced lung metastases in 100% of the NIH nude mice recipients, secreted augmented levels of type IV collagenase, and invaded human amnion basement membrane in vitro [1].
• An IFN-induced 150-kDa protein and a constitutively expressed 110-kDa protein whose level was not altered by IFN treatment were detected in human amnion U and neuroblastoma SH-SY5Y cell lines [2].
• In this work four different inhibitors of cysteine proteinases have been shown to inhibit the invasion of the human amnion by murine melanoma and mammary carcinoma cells in vitro [3].
• The effects of a single molecularly cloned subspecies of human leukocyte interferon (IFN-alpha A) on vesicular stomatitis virus (VSV) macromolecular synthesis in human amnion U cells were examined [4].
• In light of the rise in levels of glucocorticoids (GC) in amniotic fluid associated with preterm labor, in the present study we examined the effects of GC on the expression of major ECM proteins in cultures of amnion epithelial cells recovered after digestion of human term amnions [5].

High impact information on Amnion

• However, OT is also synthesized in peripheral tissues, e.g., uterus, placenta, amnion, corpus luteum, testis, and heart [6].
• To understand the role of proteinases in tumor invasion, the effects of inhibitors of metallo-, serine-, and cysteine-proteinases on this process were studied using 125I-iododeoxyuridine-labeled B16/BL6 cells grown on human amnion basement membrane [7].
• Tumor invasion through the human amniotic membrane: requirement for a proteinase cascade [7].
• The endodermal portion of the visceral yolk sac did not react, while small amounts were found in the amnion [8].
• Noradrenaline induced an interferon-like antiviral state in mouse myocardial cells but not human amnion (WISH) cells [9].

Chemical compound and disease context of Amnion

• Under these conditions of high serine and cysteine protease inhibitor concentrations, no significant decrease in B16-F10 melanoma cell invasion through the amnion was observed [10].
• Eighty women (43 receiving ampicillin) with premature labor and/or prolonged rupture of amniotic membranes were randomized [11].
• Transforming growth factor-beta opposes the stimulatory effects of interleukin-1 and tumor necrosis factor on amnion cell prostaglandin E2 production: implication for preterm labor [12].
• OBJECTIVE: Our goal was to evaluate the effect of Escherichia coli, Bacteroides fragilis, Mycoplasma hominis, and Staphylococcus aureus on cytokine and prostaglandin production by amnion cells in vitro [13].
• Preterm labor: stimulation of arachidonic acid metabolism in human amnion cells by bacterial products [14].

Biological context of Amnion

• We conclude that amnion epithelial cells undergo a process of programmed cell death associated with orchestrated extracellular matrix degradation which begins before the onset of active labor [15].
• The endogenous bFGF levels of the BCE cell clones correlated with the extent of cell migration after wounding of a monolayer and the degree of invasion of the human amniotic membrane [16].
• Increased phosphorylation of elongation factor 2 during mitosis in transformed human amnion cells correlates with a decreased rate of protein synthesis [17].
• Endothelin-1 gene expression and regulation of endothelin mRNA and protein biosynthesis in avascular human amnion. Potential source of amniotic fluid endothelin [18].
• Western blot analysis of the amnion and choriodecidua showed no differences in amounts of either cPGES or mPGES at term or preterm, with or without labor, in either tissue with advancing gestation [19].

Anatomical context of Amnion

• Although these mutants can form nonaxial tissues, such as the allantois, amnion, and yolk sac mesoderm, they display defective patterning of the primitive streak and other axial structures, and frequently exhibit truncations or disorganization of posterior embryonic regions [20].
• We have demonstrated synthesis of OT mRNA in amnion, chorion, and decidua using Northern blot analysis, ribonuclease protection assays, and in situ hybridization [21].
• Treatment of the amnion with hyaluronate, heparin, and chondroitin ABC lyase affected the structure of both the epithelium and the extracellular matrix and resulted in a significant increase in tumor cell invasion, but it had no significant effect on the invasion of the parent cell line [22].
• In the human amnion system, neutrophils were shown to penetrate through the tissue when the peptide chemoattractant f-Met-Leu-Phe was placed on the opposing side [23].
• Here, we report the results of a detailed analysis of expression of these genes within the developing placenta and extra-embryonal membranes (i.e., yolk sac and amnion) [24].

Associations of Amnion with chemical compounds

• Effect of cortisol, prolactin and ADH on the amniotic membrane [25].
• In amnion cells in monolayer culture, TNF-alpha stimulated PGE2 formation, and TNF-alpha was cytostatic (inhibited [3H]thymidine incorporation into DNA) but not cytolytic in amnion cells [26].
• The C1 fragment also inhibited tumor cell attachment to whole amnion basement membrane in vitro [27].
• Effect of bacterial products on prostaglandin E production by amnion cells [28].
• This invasive process was inhibited by antibodies to laminin or to fibronectin, two major glycoproteins of the amniotic membrane, by monovalent Fab' fragments of antibodies to the fibronectin receptor, and, finally by synthetic peptides that contain the cell-binding sequence Arg-Gly-Asp-Ser of fibronectin [29].

Gene context of Amnion

• In an in vitro amnion invasion assay system, rTIMP inhibited the invasion of B16-F10 murine melanoma cells through the human amniotic membrane at an identical concentration to that reported previously for natural TIMP [30].
• One striking defect in Hand1-null embryos was the accumulation of hematopoietic cells between the yolk sac and the amnion because of defects in the yolk sac vasculature [31].
• In Pitx2(-)(/)(-) embryos there was an increase in mesodermal cells in the distal end of the left lateral body wall and an amnion continuous with the lateral body wall thickened in its mesodermal layer [32].
• In this investigation we sought to identify the specific endothelin (ET) gene that is expressed in amnion and to determine whether endothelin is produced by amnion [18].
• Northern analysis with use of locus-specific probes demonstrated that amnion expresses two class Ib genes, HLA-E and HLA-G [33].

Analytical, diagnostic and therapeutic context of Amnion

• Immunofluorescence shows localisation of prolactin to human amnion [34].
• Western blot and immunohistochemical analyses confirmed that interstitial collagenase protein appears in association with the loss of amnion type I collagen [15].
• Media immunoreactive CRH concentrations averaged 625 +/- 45 (SE) pg/10(5) cells in amnion, 701 +/- 56 pg/10(5) cells in chorion, and 580 +/- 60 pg/10(5) cells in decidual tissue obtained at cesarean section [35].
• By radioimmunoassay, we found that human amnion cells in primary monolayer culture secrete immunoreactive PTH-rP into the medium [36].
• In immunoprecipitation studies, DEX treatment reduced FN and collagen III synthesis to 20% of control levels, suggesting that GC may coordinately reduce the synthesis of major ECM proteins in amnion cells [5].

References