Increase in Proliferation and Differentiation of Neural Progenitor Cells Isolated from Postnatal and Adult Mice Brain by Wnt-3a and Wnt-5a

Abstract

Wnt signaling is implicated in the control of cell growth and differentiation during CNS development. These findings are based on studies of mouse and chick models. However, the action of Wnt signaling, at the cellular level, is poorly understood. In this study, we investigated the roles of Wnt-3a and Wnt-5a on differentiation and proliferation of postnatal neural progenitor cells (NPCs) in mice.NPCs were isolated from the subventricular zone (SVZ) of PN-1 and adult ICR mice. Plasmids containing active Wnt-3a or Wnt-5a were transfected to NPCs; their effects on the formation of neurospheres and differentiation into neuronal cells were then determined. Transfection of Wnt-3a and Wnt-5a plasmids promoted regeneration of neurospheres and differentiation into Map2-positive cells, and decreased differentiation into GFAP-positive cells. The conditioned media obtained from Wnt-3a or Wnt-5a transfected NPCs showed similar effects on differentiation of NPCs with cDNA transfection, although the magnitude of stimulatory effect was less than that by plasmid transfection. Wnt-3a and Wnt-5a transfection did not affect Brdu incorporation of neuronal or glial progenitors in differentiation media. Wnt-3a and Wnt-5a plasmid transfection and the treatment of Wnt-3a and Wnt-5a conditioned media increased beta-catenin levels in NPCs. Wnt-3a had a greater effect on beta-catenin levels than Wnt-5a. The PKC inhibitor completely blocked the Wnt-5a effect on neuronal differentiation in NPCs. These findings suggest that Wnt-3a and Wnt-5a each have distinct effects on the proliferation and differentiation of NPCs in postnatal mice.

The Wnt receptor Ryk controls specification of GABAergic neurons versus oligodendrocytes during telencephalon development

“…Wnt1, Wnt3, Wnt3a, Wnt4, Wnt5a), we sought to identify the Wnt ligand(s) responsible for this effect by employing a series of Wnt treatment experiments. Wnt3a is known to promote neuronal differentiation of NPCs of the forebrain and spinal cord (Kalani et al, 2008;Lie et al, 2005;Muroyama et al, 2002;Yu et al, 2006). Our in vitro study showed that Wnt3a promotes GABAergic neuron differentiation and that Ryk receptor is required for this effect.…”

“…Wnt3a has been shown to bind to Ryk receptor to promote neurite outgrowth (Lu et al, 2004), and Wnt3a can induce neuronal differentiation of NPCs in both the forebrain and spinal cord (Kalani et al, 2008;Lie et al, 2005;Muroyama et al, 2002;Yu et al, 2006). Wnt3a has recently been shown to upregulate gene expression of the oligodendrocyte inhibitors Id2 and Id4, and to downregulate expression of myelin genes such as MBP in hippocampus-derived adult neural progenitor cells and oligodendroglial cell cultures (Ye et al, 2009).…”

The Adult Ventricular–Subventricular Zone (V-SVZ) and Olfactory Bulb (OB) Neurogenesis

“…In vitro studies have shown that WNT3A and WNT5A promote proliferation and neuronal differentiation of SVZ-derived NSC cultures (Yu et al 2006), and transcripts for these factors have been identified in the V-SVZ and adult OB (Shimogori et al 2004;Lim et al 2006;Ramos et al 2013). The canonical Wnt signaling pathway involves the binding of WNT to Frizzled (Fz) receptors, which leads to stabilization of b-catenin protein, its nuclear translocation, and function as a transcriptional coactivator.…”

Wnt5aIs a Transcriptional Target ofDlxHomeogenes and Promotes Differentiation of Interneuron ProgenitorsIn VitroandIn Vivo

“…Wnt3 and Wnt7a specif-ically favor neuronal differentiation of late, but not of early, cortical NPCs (Hirabayashi et al, 2004;Hirabayashi and Gotoh, 2005;Yu et al, 2006), and Wnt5a stimulates the differentiation of dopaminergic neurons (Castelo-Branco and Arenas, 2006;Andersson et al, 2008). As Wnt ligands elicit such a variety of responses, their functions need to be determined in a cell type-and context-dependent manner.…”