Derivation of human triploid trophoblast stem cells

Human trophoblast stem cells (hTSCs) are counterparts of the precursor cells of the placenta and are valuable cell models for the study of placental development and the pathogenesis of placental diseases. The aim of this work was to establish a triploid human TSC (hTSC3PN) derived from the tripronuclear embryos, which are clinically discarded but readily available, for potential applications in basic placental research and disease modeling.Eighteen tripronuclear human zygotes from IVF were collected and cultured for 5-6 days. Five high-quality blastocysts were harvested and were individually cultured in hTSC medium. Finally, two hTSC lines were established after 10 days and could be passaged stably.The karyotyping analysis showed that hTSC3PN contained three sets of chromosomes. And the hTSC3PN exhibited typical features of hTSCs, with the ability to differentiate into two trophoblast lineages: extravillous cytotrophoblasts (EVTs) and syncytiotrophoblasts (STs). In addition, the hTSC3PN can mimic some vital features of trophoblast, including hormone secretion and invasion. Further studies showed that the proliferation and differentiation of hTSC3PN were reduced compared with normal hTSCs, which may be related to the disturbed metabolic signaling in hTSC3PN.We established the triploid hTSC lines derived from tripronuclear embryos, which provides a potentially useful research model in vitro to study human placental biology and diseases.