Mapping of CIP/KIP inhibitors, G1 cyclins D1, D3, E and p53 proteins in the rat term placenta

Abstract

As cell cycle regulation is fundamental to the normal growth and development of the placenta, the aim of the present study was to determine the immunolocalizations of cell cycle related proteins, which have key roles in proliferation, differentiation and apoptosis during the development of the rat placenta. Here immunohistochemistry has been used to localize G1 cyclins (D1, D3, E), which are major determinants of proliferation, CIP/KIP inhibitors (p21, p27, p57), p53 as a master regulator and proliferating cell nuclear antigen in all cell types of the rat term placenta. The proportion of each cell type immunolabeled was counted. Cyclin D1 and cyclin D3 were present mostly in cells of the fetal aspect of the placenta, whereas the G1/S cyclin E was present only in the spongio- and labyrinthine trophoblast populations. Among the CIP/KIP inhibitors, p21 was present only in cells of the fetal aspect whereas p27 and p57 were found in all cell types studied. p53 was only found in a small proportion of cells with no co-localization of p53 and p21. The data suggest that the cells of the fetal side of the rat placenta still have some proliferation potential which is kept in check by expression of the CIP/KIP cell cycle inhibitors, whereas cells of the maternal aspect have lost this potential. Apoptosis is only marginal in the term rat placenta. In conclusion, proliferation and apoptosis in rat placental cells appears controlled mostly by the CIP/KIP inhibitors in late pregnancy.

The Effects of Glucocorticoids on Fetal and Placental Development

“…Among the Cip/Kip inhibitors, p21 was present only in cells of the fetal aspect whereas p27 and p57 were found in all cell types studied. p53 was only found in a small proportion of cells with no co-localization of p53 and p21 [88]. Schematic representation of our immunohistochemistry results in the rat placenta is showed in Figure 2.…”

“…Ch: Chorion, LZ: Labyrinth Zone (fetal placenta), JZ: Junctional Zone (maternal placenta) [88]. We aimed to investigate the effects of maternally administered synthetic glucocorticoid Dex on cell proliferation, cell cycle arrest or apoptosis of placental development.…”

Serum homocysteine level and gestational diabetes mellitus: A meta‐analysis

“…Increased expression of villous cytotrophoblast, syncytiotrophoblast, stromal cells and fetal endothelial cells in the human placenta is reported among women with diabetes. Furthermore, reduced apoptotic index and expression of some apoptotic genes are also reported in the placenta of women with GDM. More investigations are required to explore the balance between proliferation, apoptosis and differentiation in trophoblast cells among women with diabetes mellitus in order to ensure their relationship.…”

Therapeutic Targeting of the Warburg Effect in Pancreatic Cancer Relies on an Absence of p53 Function

“…The primary antibodies were diluted at 1/400 (TIGAR) and 1/100 (p53) and incubated with the sample for 1 hour at room temperature for TIGAR and 12 hours at 4°C for p53. A biotinylated goat anti-rabbit antibody was used as the secondary antibody (25,26). Stained sections were examined microscopically at 40× magnification and images were captured.…”