QUANTITATIVE AND KINETIC PROFILE OF Wnt/β-CATENIN SIGNALING COMPONENTS DURING HUMAN NEURAL PROGENITOR CELL DIFFERENTIATION

ReNcell VM is an immortalized human neural progenitor cell line with the ability to differentiate in vitro into astrocytes and neurons, in which the Wnt/beta-catenin pathway is known to be involved. However, little is known about kinetic changes of this pathway in human neural progenitor cell differentiation. In the present study, we provide a quantitative profile of Wnt/beta-catenin pathway dynamics showing its spatio-temporal regulation during ReNcell VM cell differentiation. We show first that T-cell factor dependent transcription can be activated by stabilized beta-catenin. Furthermore, endogenous Wnt ligands, pathway receptors and signaling molecules are temporally controlled, demonstrating changes related to differentiation stages. During the first three hours of differentiation the signaling molecules LRP6, Dvl2 and beta-catenin are spatio-temporally regulated between distinct cellular compartments. From 24 h onward, components of the Wnt/beta-catenin pathway are strongly activated and regulated as shown by mRNA up-regulation of Wnt ligands (Wnt5a and Wnt7a), receptors including Frizzled-2, -3, -6, -7, and -9, and co-receptors, and target genes including Axin2. This detailed temporal profile of the Wnt/beta-catenin pathway is a first step to understand, control and to orientate, in vitro, human neural progenitor cell differentiation.