Direct Involvement of HERV-W Env Glycoprotein in Human Trophoblast Cell Fusion and Differentiation

• DOI: 10.1128/mcb.23.10.3566-3574.2003
• Publication Date: 2003-05-01T02:00:00Z
• Authors: Jean-Louis Frendo; Delphine Olivier; Valérie Cheynet; Jean-Luc Blond; Olivier Bouton; Michel Vidaud; Michèle Rabreau; Danièle Evain-Brion; François Mallet
• Keywords: Cytotrophoblast; Cell fusion; Syncytiotrophoblasts; Syncytium; Trophoblast; Syncytiotrophoblasts

We recently demonstrated that the product of HERV-W env gene, a retroviral envelope protein also dubbed syncytin, is highly fusogenic membrane glycoprotein inducing formation syncytia on interaction with type D mammalian retrovirus receptor. In addition, detection Env (Env-W) expression in placental tissue sections led us to propose role for this placenta formation. To evaluate hypothesis, we analyzed involvement Env-W differentiation primary cultures human villous cytotrophoblasts spontaneously differentiate by cell fusion into syncytiotrophoblasts vitro. First, observed mRNA and are colinear cytotrophoblast chorionic gonadotropin (hCG), marker syncytiotrophoblast Second, vitro stimulation trophoblast cyclic AMP associated concomitant increase hCG expression. Finally, using specific antisense oligonucleotides, inhibition leads decrease differentiation, secretion culture medium oligonucleotide-treated cells being decreased fivefold. Taken together, these results strongly support direct differentiation.