CODISTRIBUTION OF BASIC FIBROBLAST GROWTH-FACTOR AND HEPARAN-SULFATE PROTEOGLYCAN IN THE GROWTH ZONES OF THE HUMAN PLACENTA

In order to obtain an insight into morphogenetic processes such as ang iogenesis, cell proliferation, and tissue remodeling we have studied t he localization of basic fibroblast growth factor (bFGF) and heparan s ulfate proteoglycan (HSPG) in the human placenta by immunohistochemist ry. Positive reaction product for bFGF is found mainly in the villous trophoblastic covering and for HSPG in the villous basement membranes. A codistribution of the two molecules is detectable in first trimeste r placental tissue, in areas previously identified as being responsibl e for the growth of the villous tree, i.e., in the mesenchymal villi a nd the cytotrophoblastic cell islands and cell columns, both consistin g of extravillous trophoblast. HSPG and bFGF are codistributed in the distal half of the villous stroma in the mesenchymal villi. In cell is lands and cell columns, bFGF is detectable in the cytoplasm of the ext ravillous cytotrophoblastic cells, whereas HSPG is localized between t he extravillous cytotrophoblastic cells and in their cytoplasm. HSPG-b FGF codistribution in term placenta is confined to the walls of fetal vessels and to some extravillous cytotrophoblastic cells in the basal plate. The codistribution of bFGF and HSPG in first trimester placenta l tissue suggests that these two molecules play a pivotal role in the morphogenetic processes mentioned above in early stages of gestation.