Sw71 TWIST1 Knockout Model for Impaired Embryo Implantation

Successful human implantation depends on precise and adequate invasion of the extravillous trophoblast into maternal decidua. The role of the TWIST1 transcription factor in this process remains incompletely defined. In humans, deficiencies in EVT functionality are associated with great obstetrical syndromes. Understanding the TWIST1-based implantation impairment is limited by the lack of reliable in vitro models. To address this gap, we combined the ex vivo analysis of TWIST1 expression in healthy vs. aborted gestational tissues with in vitro Sw71 TWIST1-CRISPR/Cas9 knocked-out human blastocyst-like surrogate (Sw71TW1-KO BLS). We found strong expression of TWIST1 at the maternal–fetal interface of healthy but not of missed aborted pregnancy. The generated Sw71TW1-KO BLSs preserved blastocyst-like morphology but showed reduced expression of the essential HLA-G and HLA-C molecules. Sw71TW1-KO BLSs’ functionality was assessed by tests for migration and invasion. Sw71TW1-KO BLSs showed markedly impaired migration. Placed on Matrigel-coated endometrial stromal cell scaffold, Sw71TW1-KO BLSs failed to invade the scaffold. The results support that TWIST1 is an important component of the healthy decidua and placenta early in human pregnancy. The 3D model Sw71TW1-KO BLSs with suboptimal HLA expression and impaired function might serve as a tool for investigating TWIST1-associated trophoblast defects.