Use of trophoblast cells in tissue culture for fetal chromosomal studies

Enzymatic isolation of human trophoblast and culture on various substrates: comparison of first trimester with term trophoblast

A simple method is described for the isolation of trophoblast cells from both first trimester and term placenta. Trophoblast preparations were characterized by light microscopy, scanning and transmission election miscroscopy and immunohistochemistry to distinguish these cells from mesenchyme and endothelium. Trophoblast cells were cultured on various substrates and a comparison made of their ability to attach, proliferate and function. A collagen gel substrate produced by repolymerization of an acid soluble collagen fraction from chorionic villi allowed rapid attachment of trophoblast cells and maintainance of their original morphology. Term trophoblast cells were shown to become fully functional in short term (three day) cultures by virtue of their increased immunocytochemical staining for the presence of beta hCG, hPL and SPI. beta hCG increased significantly by day three thus demonstrating functional activation. Trophoblast cells from first trimester placenta formed proliferating colonies of hormone producing cells while those from term placenta reaggregated into clusters and closely resembled syncytiotrophoblast both morphologically and functionally. This short term culture system for term trophoblast will allow further studies into the biology of trophoblast polypeptide hormone synthesis and secretion.

The use of pregnancy serum to obtain trophoblastic cell cultures

A method for obtaining trophoblastic cell cultures from first-trimester human placental villi is described. The essential feature of the method is the use of serum from a pregnant woman in the culture medium. Using this technique, pure cultures of trophoblastic cells are produced in 88 per cent of cases.

Hydatidiform moles: methods for culture and cytogenetic analyses

Placental tissue with macroscopic visible vesicles was processed for chromosome analysis. Enzymatic tissue dissociation, culture initiation in Chang's medium, and final culture in a medium with high glucose content were used, which increased the success rate for karyotyping from 55% to 93%. Median culture time necessary for obtaining a karyotype decreased to about 1 week, irrespective of the chromosomal constitution. This was achieved in spite of increasing time for transportation. The metaphases obtained permitted detailed analysis of chromosomal polymorphisms. In 8 of 44 cases, the karyotype was established on short-term culture alone, which proved to be a valuable supplement in this study.

Cytoskeletal markers and specific protein production in cells cultured from human first and third trimester placentae

In primary, short-term cultures derived from first and third trimester placentae, 60 to 90 and 70 to 95%, respectively, of the total cell population positively stain for cytokeratin intermediate filaments, typical of epithelial, i.e. trophoblastic cells. The rest of the cells express only vimentin intermediate filaments and thus are of mesenchymal origin. Only the cytokeratin-positive cells express human chorionic gonadotropin (hCG), whereas both the epithelial and the mesenchymal cells stain positively for pregnancy-specific beta-1-glycoprotein (SP1). Cytokeratin-negative and vimentin-positive cell overgrowth is observed in cultures derived from first and early third trimester placentae. The cells constituting the monolayer thus formed are of fetal origin as evidenced by the expression of Y-body in over 80% of them. The cultured cells synthesize and secrete hCG and SP1. The activity of these trophoblast-specific functions is inversely proportional to the gestational age of the placenta. Production of specific proteins and expression of intermediate filaments are proposed as criteria for defining the nature and origin of placental cells in primary, short-term cultures.