Differentiation of KISS1-Expressing Cells from Human Pluripotent Stem Cells: Many Roads To Rome
Introduction Kisspeptin-secreting (Kiss) neurons govern human puberty and reproduction. In the arcuate nucleus (ARC), they control pulsatile release of gonadotropin-releasing hormone (GnRH), while Kiss neurons in the preoptic area (POA) control GnRH surge. Since animal models do not fully recapitulate the human phenotype, a human model to study these neurons is crucial. Methods We differentiated human pluripotent stem cells (hPSCs) into neuron cultures using two distinct strategies: FGF8 protocol, consisting of dual SMAD inhibition (dSMADi), FGF8b, and Notch inhibition; and SHH protocol, consisting of dSMADi and SHH activation, followed by Notch inhibition. Neuron cultures obtained on day 45 were characterized at the mRNA level using RT-qPCR. Results Both strategies resulted in neuron cultures where significant KISS1 expression could be detected. SHH-derived neuron cultures expressed high NKX2-1 and the ARC markers POMC, NHLH2, and NR5A2, while FGF8-derived neuron cultures expressed low NKX2-1 and the anterior POA marker FOXG1. Conclusions We provide the first ever strategies to differentiate hPSCs into neuron cultures that express KISS1. Future studies providing in depth transcriptomic, protein, and functional characterization are needed to establish the properties of these models.