Deciphering villous and extravillous trophoblast differentiation: Participation of the Krüppel-like transcription factor 6

ANDREA MIRANDA; LUCILE KOURDOVA; ANA RACCA; MARÍA LAURA ROJAS; CRUZ DEL PUERTO, MARIANO M.; SUSANA GENTI DE RAIMONDI; GRACIELA PANZETTA DE DUTARI

Congreso; 9th Latin American Symposium on Maternal-Fetal Interaction and Placenta (SLIMP 2022); 2022

Trophoblast differentiation is a very complex process. KLF6 is a ubiquitoustranscription factor with an N-terminal acidic transactivation domain anda C-terminal zinc finger DNA-binding domain. klf6-/- mice die at day E12.5showing impaired placenta development. KLF6 expression is early upregulated during syncytialization in BeWo and primary villous trophoblastcells, and in HTR8/Svneo cells exposed to hypoxia. The aim of the presentstudy was to analyze the participation of KLF6 in human villous andextravillous trophoblast cell differentiation.BeWo cells were transduced with lenti-virus particles to generate stablecell lines for the full-length KLF6 protein, a deletion mutant lacking itsacidic domain (KLF6Dac), or the empty vector. These cell lines weretreated or not with 30 mM forskolin and cell fusion was analysed byimmunofluorescence. HTR8/Svneo cells were transiently silenced forKLF6 or stably transfected with the KLF6Dac construct and migration wasanalyzed through wound healing and transwell assays. Transcript andprotein levels were measured by qRT-PCR and western blot, respectively.Cell proliferation was evaluated by BrdU labelling and cell countingassays.Results reveal that KLF6 is an inducer of villous trophoblast cell differentiation through a mechanism that involves its N-terminal domain, whileKLF6 downregulation promotes HTR8/Svneo cells differentiation. Thefusion index of KLF6-BeWo cells is significantly higher than that observedin the empty vector-BeWo cells accompanied by a decrease in cell proliferation. Forskolin-induced cell fusion is further increased in KLF6-BeWocells. On the other hand, KLF6 silencing in HTR8/Svneo cells leads toincreased migration together with an induction of a mesenchymalphenotype with higher levels of N-cadherin.Present results reveal that KLF6 regulates villous trophoblast differentiation and fusion, but also the extravillous differentiation into a migratoryphenotype.