Belinda M. Chapman

Differentiation-dependent expression of gelatinase B/matrix metalloproteinase-9 in trophoblast cells

Abstract The purpose of this study was to evaluate the Rcho-1 trophoblast culture system as a model for studying trophoblast invasion and to examine stage-specific expression of enzyme(s) potentially participating in rat trophoblast giant cell invasive behavior. The invasive behavior of the differentiating Rcho-1 trophoblast cells was demonstrated using Matrigel invasion chambers. Gelatin zymography and Western blot analysis of conditioned medium from differentiating Rcho-1 trophoblast cell cultures and rat ectoplacental cone outgrowths revealed a differentiation-dependent increase in gelatinase B/matrix metalloproteinase (MMP-9). Nothern blot and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of Rcho-1 trophoblast or ectoplacental cone cells also showed increasing expression of MMP-9 accompanying cell differentiation. Rcho-1 trophoblast cells stably transfected with MMP-9 promoter/luciferase reporter constructs exhibited a differentiation-dependent increase in MMP-9 promoter activation. In conclusion, trophoblast giant cell differentiation is characterized by transcriptional activation of the MMP-9 gene and appearance of the invasive phenotype.

Trophoblast differentiation. An in vitro model for trophoblast giant cell development.

Trophoblast cells are situated between maternal and embryonic compartments and effectively permit the embryo to develop within the female reproductive tract. These cells develop along a multilineage differentiation pathway and their growth and differentiation are pivotal to the establishment and maintenance of pregnancy (1-4). In the mouse and rat, there are at least four recognizable differentiated cell phenotypes: trophoblast giant cells, spongiotrophoblast cells, glycogen cells, and syncytial trophoblast cells. The cell types are arranged into two distinct regions within the chorioallantoic placenta: the junctional zone and the labyrinth zone. The junctional zone is proximal to maternal tissues and has a prominent endocrine role, whereas the labyrinth zone is adjacent to fetal tissues and has significant endocrine and transport roles. Trophoblast giant cells are one of the first differentiated cells to arise in the developing embryo (1-4). Morphologically, they are striking in their large size and are easily recognized within the developing placenta. Trophoblast giant cells form via a process referred to as endoreduplication, continued DNA replication without concomitant cell division, and are situated at the maternal-fetal interface within the junctional and labyrinth zones of the chorioallantoic placenta. This trophoblast cell population is characterized by its endocrine and invasive phenotypes (4,5). Spongiotrophoblast cells represent another endocrine cell population of the chorioallantoic placenta and share a developmental linkage with glycogen cells, which are typified by their accumulation of glycogen (4,6). Syncytial cells have a significant role in fetal-maternal exchange and arise by cell fusion (6). Progress in studying the control of differentiation in a number of different cell types has been directly related to the development of in vitro culture models. Investigations concerning the trophoblast giant cell lineage have benefitted from the generation of a transplantable rat choriocarcinoma by Dr. Shinichi Teshima and his colleagues at the National Cancer Institute, Tokyo, Japan (7). The tumor was experimentally induced by removal of the fetus and exposure of placental primordia to the extrauterine environment and was found to be transplantable. Female rats bearing the transplanted choriocarcinoma

Control of trophoblast cell differentiation: Lessons from the genetics of early pregnancy loss and trophoblast neoplasia

Trophoblast cell differentiation is crucial to the morphogenesis of the placenta and thus the establishment of pregnancy and the growth and development of the embryo/fetus. In the present review, we discuss current evidence for the existence of regulatory genes crucial to trophoblast cell differentiation and placental morphogenesis. The elucidation of regulatory pathways controlling normal differentiation of trophoblast cells will facilitate the identification of sensitive junctures in the regulatory pathways leading to various developmental disorders, including those associated with the initiation of pregnancy, fetal growth retardation and gestational trophoblast disease.

Prolactin-like protein-A gene structure and chromosomal mapping

Prolactin-like protein-A (PLP-A) is a member of the prolactin(PRL) gene family and is expressed by trophoblast cells of thedeveloping rat and mouse chorioallantoic placenta (Lin et al. 1997;Mu¨ller et al. 1998). PLP-A has been proposed to participate in thecontrol of maternal immunologic responses prerequisite for theestablishment of pregnancy through its specific interactions withuterine natural killer cells (H. Mu¨ller and M.J. Soares, unpub-lished). In this report, we present data on the structure of the mousePLP-A gene and describe its chromosomal localization.A genomic DNA library generated from a 129/SvEv strainmouse liver and packaged in the Lambda FIX II vector was agenerous gift of Lexicon Genetics, Inc. (Houston, Tex.). Approxi-mately 1 × 10

Characterization of Two Nonclassical Members of the Placental Prolactin Family from the Rat

Characterization of Two Nonclassical Members of the Placental Prolactin Family from the Rat