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Biochemical characterization and modulation of LH/CG—receptor during human trophoblast differentiation
Author(s) -
Pidoux Guillaume,
Gerbaud Pascale,
Tsatsaris Vassilis,
Marpeau Olivier,
Ferreira Fatima,
Meduri Geri,
Guibourdenche Jean,
Badet Josette,
EvainBrion Danièle,
Frendo JeanLouis
Publication year - 2007
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.20995
Subject(s) - syncytiotrophoblast , cytotrophoblast , syncytiotrophoblasts , trophoblast , human chorionic gonadotropin , biology , endocrinology , medicine , luteinizing hormone , gonadotropin , receptor , placenta , microbiology and biotechnology , hormone , fetus , biochemistry , pregnancy , genetics
Due to the key role of the human chorionic gonadotropin hormone (hCG) in placental development, the aim of this study was to characterize the human trophoblastic luteinizing hormone/chorionic gonadotropin receptor (LH/CG‐R) and to investigate its expression using the in vitro model of human cytotrophoblast differentiation into syncytiotrophoblast. We confirmed by in situ immunochemistry and in cultured cells, that LH/CG‐R is expressed in both villous cytotrophoblasts and syncytiotrophoblasts. However, LH/CG‐R expression decreased during trophoblast fusion and differentiation, while the expression of hCG and hPL (specific markers of syncytiotrophoblast formation) increased. A decrease in LH/CG‐R mRNA during trophoblast differentiation was observed by means of semi‐quantitative RT‐PCR with two sets of primers. A corresponding decrease (∼60%) in LH/CG‐R protein content was shown by Western‐blot and immunoprecipitation experiments. The amount of the mature form of LH/CG‐R, detected as a 90‐kDa band specifically binding 125 I‐hCG, was lower in syncytiotrophoblasts than in cytotrophoblasts. This was confirmed by Scatchard analysis of binding data on cultured cells. Maximum binding at the cell surface decreased from 3,511 to about 929 molecules/seeded cells with a kDa of 0.4–0.5 nM. Moreover, on stimulation by recombinant hCG, the syncytiotrophoblast produced less cyclic AMP than cytotrophoblasts, indicating that LH/CG‐R expression is regulated during human villous trophoblast differentiation. J. Cell. Physiol. 212: 26–35, 2007. © 2007 Wiley‐Liss, Inc.