Characterization of Proliferative Activity in Bovine Placentomes Between Day 150 and Parturition by Quantitative Immunohistochemical Detection of Ki67-Antigen

Schuler, Gerhard; Wirth, C; Klisch, Karl; Failing, Klaus; Hoffmann, Bernd

doi:10.1046/j.1439-0531.2000.00231.x

Cited by 6 publications

(5 citation statements)

References 21 publications

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“…Obviously, in equine microcotyledons, proliferation of T cells is more strictly related to growth (Gerstenberg et al. 1999) than to cell turnover, as it has been shown in bovine placentomes (Wooding and Wathes 1980; Schuler et al. 2000).…”

Section: Discussionmentioning

confidence: 93%

Immunohistochemical Localization of Oestrogen Receptors α and β, Progesterone Receptor and Aromatase in the Equine Placenta

Abd-Elnaeim¹,

Derar

Wilsher

et al. 2009

Reprod Domestic Animals

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The functions of placental oestrogens during equine pregnancy are still unclear. Yet, they may act predominantly as local regulators of growth and differentiation in the microplacentomes. Thus, expression patterns of oestrogen receptors (ERs) alpha and beta were investigated in the microcotyledonary placenta from pregnant mares at 110, 121, 179, 199 and 309 days of gestation by immunohistochemistry. In microplacentomes, both the ER isoforms were detected in trophoblast (T) cells, chorionic villous stroma (FS), microcaruncular epithelium (ME) and microcaruncular stroma (MS). Proportions of positive cells were 38-91% (T), 11-41% (FS), 55-89% (ME), 17-51% (MS) for ERalpha and 66-76% (T), 21-37% (FS), 41-68% (ME) and 24-55% (MS) for ERbeta. Between days 110 and 199, proportions of cells positive for progesterone receptor (PR) varied between 19% and 62% (T), 3% and 50% (CS), 15% and 46% (ME), and 4% and 33% (MS). At day 309, PR was virtually absent in T, CS and ME (percentages < 0.1), whereas in MS 14.3% of cells were still positive. The expression of ERs and PR in equine microplacentomes gives evidence for a role of placental steroids as regulators of placental growth, differentiation and function. The detection of ERalpha, ERbeta and PR in foetal and maternal vascular tissue suggests that placental steroids are also involved in the control of placental angiogenesis and /or vascular functions. The co-localization of ERs with aromatase in T suggests auto- or intracrine functions of oestrogens in this cell type.

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Section: Discussionmentioning

confidence: 93%

Immunohistochemical Localization of Oestrogen Receptors α and β, Progesterone Receptor and Aromatase in the Equine Placenta

Abd-Elnaeim¹,

Derar

Wilsher

et al. 2009

Reprod Domestic Animals

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“…In the present study, FN coating led to a significantly higher cell proliferation than coating with other ECM proteins. Continuously high cell proliferation, especially in the caruncular epithelium and independent of total caruncular growth, has been shown to be present in placentomes throughout pregnancy [38]. Thus, high proliferation, especially in this area of the placentomes, is necessary for tissue remodeling and the compensation of the destructive activity of the invading TGC.…”

Section: Focal Adhesion Assembly In Bovine Caruncular Epithelium Is Dmentioning

confidence: 99%

Integrin Activation in Bovine Placentomes and in Caruncular Epithelial Cells Isolated from Pregnant Cows

Bridger

Haupt

Leiser

et al. 2008

Biology of Reproduction

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In the bovine synepitheliochorial placenta, restricted trophoblast invasion requires complex interactions of integrin receptors with proteins of the extracellular matrix (ECM) and integrin receptors of neighboring cells. Activated integrins assemble to focal adhesions and are linked to the actin cytoskeleton via signaling molecules including alpha-actinin (ACTN), focal adhesion kinase (PTK2 or FAK), phosphotyrosine, and talin (TLN1). Aims of this study were to assess integrin activation and focal adhesion assembly within epithelial cells of bovine placentomes and low-passage (not transformed) placentomal caruncular epithelial cells cultured on dishes coated with ECM proteins. Immunofluorescence analysis was performed to colocalize the signaling molecules ACTN, PTK2, phosphotyrosine, and TLN1 with each other and with beta(1)-integrin (ITGB1) in placentomal cryosections throughout pregnancy and in caruncular epithelial cells in vitro. Antibody specificity was confirmed by Western blot. Cells were cultured on uncoated dishes, and the dishes were coated with fibronectin (FN), laminin (LAMA), and collagen type IV (COL4), thereby statistically assessing cell number and qualitatively assessing the expression pattern of ITGB1, phosphotyrosine, and TLN1. Results demonstrated integrin activation and focal adhesion assembly in the placentome and that low-passage caruncular epithelial cells maintain integrin-associated properties observed in vivo. Expression and/or colocalization of signaling molecules with ITGB1 confirmed, for the first time, integrin activation and participation in "outside-in" and "inside-out" signaling pathways. The prominent role of ECM, and FN in particular, in integrin signaling is supported by the in vitro enhancement of proliferation and focal adhesion expression. Thus, this in vitro model provides excellent potential for further mechanistic studies designed to elucidate feto-maternal interactions in the bovine placentome.

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“…These fast cycling cells, the socalled transit-amplifying cells, have a reduced ability of self-renewal and arrange primarily supply to the sufficient number of specialized cells by progressive step-bystep differentiation and maturation [Lajtha, 1979;Potten and Loeffler, 1990;Tsujimura et al, 2002]. Transferred to the bovine trophoblast epithelium, it could be hypothesized that the UTCs, which show proliferative activity [Schuler et al, 2000], represent this "transit-amplifying" cell population and ensure the TGC ordnance by transdifferentiation. Findings of heterogeneous immunohistochemical staining of UTCs [Nishita et al, 1990] may reflect the step-by-step differentiation of these "transitamplifying" cells.…”

Section: Discussionmentioning

confidence: 99%

Morphological Characterization of Basally Located Uninucleate Trophoblast Cells as Precursors of Bovine Binucleate Trophoblast Giant Cells

Attiger¹,

Boos²,

Klisch³

2018

Cells Tissues Organs

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Binucleate trophoblast giant cells (TGCs) are one characteristic feature of the ruminant placenta. In cows, the frequency of TGCs remains constant for most of the duration of pregnancy. As TGCs are depleted by their fusion with uterine epithelial cells, they need to be constantly formed. It is still unclear whether they develop from stem cells within the trophectoderm or whether they can arise from any uninucleate trophoblast cell (UTC). Within the latter, generally accepted theory, a basally located uninucleate cell (BUC) without contact to the feto-maternal interface would represent a transient cell between a UTC and a TGC. So far, no evidence for the existence of such transient cells or for the presence of stem cells has been shown. The aim of the present study is to morphologically characterize the early stages of TGC development. Placentomal tissue of 6 pregnant cows from different gestational stages (gestational days 51–214) was examined for BUCs, UTCs, and TGCs either in serial sections (light and transmission electron microscopy, TEM, n = 3), in single sections (TEM, n = 2), or by serial block face-scanning electron microscopy (n = 1). These investigations revealed the occurrence of BUCs, as well as young TGCs showing contact with the basement membrane (BM), but without apical contact to the feto-maternal interface. The study morphologically defines these 2 cell types as early stages of TGC development and shows that binucleation of TGCs can precede detachment from the BM.

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Characterization of Proliferative Activity in Bovine Placentomes Between Day 150 and Parturition by Quantitative Immunohistochemical Detection of Ki67-Antigen

Cited by 6 publications

References 21 publications

Immunohistochemical Localization of Oestrogen Receptors α and β, Progesterone Receptor and Aromatase in the Equine Placenta

Immunohistochemical Localization of Oestrogen Receptors α and β, Progesterone Receptor and Aromatase in the Equine Placenta

Integrin Activation in Bovine Placentomes and in Caruncular Epithelial Cells Isolated from Pregnant Cows

Morphological Characterization of Basally Located Uninucleate Trophoblast Cells as Precursors of Bovine Binucleate Trophoblast Giant Cells

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